pdftitle={SDCC Compiler User Guide},
pdfauthor={SDCC development team},
pdfsubject={installation, user manual},
- pdfkeywords={68hc08 8032 8051 ansi c compiler CPU DS390 embedded free Freescale GPL HC08 Intel manual Maxim mcs51 Microchip microcontroller open source PIC Z80 Zilog},
+ pdfkeywords={68hc08 8032 8051 ansi c compiler assembler CPU DS390 embedded development free Floating Point Arithmetic Freescale GPL HC08 inline Intel ISO/IEC 9899:1990 Linux MAC OS X manual Maxim mcs51 Microchip microcontroller open source PIC Unix Windows Z80 Zilog},
pdfpagemode=UseOutlines,
colorlinks=true,
linkcolor=blue] {hyperref}
\papersides 1
\paperpagestyle fancy
-\layout Comment
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
Please note: double dashed longoptions (e.g.
--version) are written this way: -
\end_inset
-
-\layout Comment
+\layout Standard
Two resp.
three consecutive dashes simply result in a long resp.
extra long dash.
-\layout Comment
+\layout Standard
Architecture specific stuff (like memory models, code examples) should maybe
later go
-\layout Comment
+\layout Standard
into seperate sections/chapters/appendices (it is hard to document PIC or
Z80 in
-\layout Comment
+\layout Standard
a 8051 centered document) - for now simply add.
+\end_inset
+
+
\layout Title
SDCC Compiler User Guide
\size normal
-SDCC 2.6.1
+SDCC 2.6.4
\size footnotesize
\newline
$Date$
\newline
$Revision$
-\layout Comment
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
The above strings enclosed in $ are automatically updated by Subversion
+\end_inset
+
+
\layout Standard
, etc.), Dallas DS80C390 variants, Freescale (formerly Motorola) HC08 and
Zilog Z80 based MCUs.
- It can be retargetted for other microprocessors, support for Microchip
- PIC, Atmel AVR is under development.
+ It can be retargeted for other microprocessors, support for Microchip PIC,
+ Atmel AVR is under development.
The entire source code for the compiler is distributed under GPL.
SDCC uses ASXXXX
\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
\end_inset
-, an open source retargettable assembler & linker.
+, an open source retargetable assembler & linker.
SDCC has extensive language extensions suitable for utilizing various microcont
rollers and underlying hardware effectively.
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="20text%">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-0, +4.294.967.296
+0, +4.294.967.295
\end_inset
</cell>
</row>
\layout Standard
+1.175494351E-38,
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+3.402823466E+38
\end_inset
</cell>
</row>
\newline
SDCC also comes with a companion source level debugger SDCDB, the debugger
- currently uses ucSim a freeware simulator for 8051 and other micro-controllers.
- SDCDB and ucSim are currently not available on Win32 platforms.
-
+ currently uses ucSim a freeware simulator for 8051 and other micro-controllers.<
\newline
\newline
files are stored is now in /usr/local/share.
\layout Itemize
-char type parameters to vararg functions are casted to int unless explicitly
- casted, e.g.:
+char type parameters to vararg
+\begin_inset LatexCommand \index{vararg, va\_arg}
+
+\end_inset
+
+ functions are casted to int unless explicitly casted
+\begin_inset Marginal
+collapsed true
+
+\layout Standard
+
+
+\series bold
+\SpecialChar ~
+!
+\end_inset
+
+, e.g.:
\newline
\family typewriter
\newline
\SpecialChar ~
\SpecialChar ~
-b = ~b; /* equivalent to b=1 instead of toggling b */
+b = ~
+\begin_inset LatexCommand \index{\~\/ Operator}
+
+\end_inset
+
+b; /* equivalent to b=1 instead of toggling b */
\begin_inset Marginal
-collapsed false
+collapsed true
\layout Standard
\end_inset
- or section
+ (Unix) or section
\begin_inset LatexCommand \ref{sub:Windows-Install}
\end_inset
-.
- More detailled instructions follow below.
+ (Windows).
+ More detailed instructions follow below.
\layout Section
Configure Options
\layout List
\labelwidthstring 00.00.0000
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-datarootdir see table below
+\newline
+
+\layout List
+\labelwidthstring 00.00.0000
+
+\SpecialChar ~
+\SpecialChar ~
docdir environment variable, see table below
\layout List
\labelwidthstring 00.00.0000
+\SpecialChar ~
+\SpecialChar ~
include_dir_suffix environment variable, see table below
\layout List
\labelwidthstring 00.00.0000
+\SpecialChar ~
+\SpecialChar ~
lib_dir_suffix environment variable, see table below
\layout List
\labelwidthstring 00.00.0000
+\SpecialChar ~
+\SpecialChar ~
sdccconf_h_dir_separator environment variable, either / or
\backslash
makes sense here.
This character will only be used in sdccconf.h; don't forget it's a C-header,
therefore a double-backslash is needed there.
+\newline
+
\layout List
\labelwidthstring 00.00.0000
\end_inset
-disable-packihx Disables building packihx
+\newline
+
\layout List
\labelwidthstring 00.00.0000
\align center
\begin_inset Tabular
-<lyxtabular version="3" rows="8" columns="3">
+<lyxtabular version="3" rows="9" columns="3">
<features>
<column alignment="block" valignment="top" leftline="true" width="0in">
<column alignment="block" valignment="top" leftline="true" width="0in">
\emph on
-$EXECPREFIX
+$EXEC_PREFIX
\emph default
/bin
\end_inset
\emph on
-$EXECPREFIX
+$EXEC_PREFIX
\emph default
\backslash
\layout Standard
+\emph on
+$DATAROOTDIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+$DATAROOTDIR
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+DATAROOTDIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
\emph on
$PREFIX
\emph default
\emph on
-$DATADIR
+$DATAROOTDIR
\emph default
/sdcc/doc
\end_inset
\emph on
-$DATADIR
+$DATAROOTDIR
\emph default
\backslash
/
\end_inset
--datadir=
+-datarootdir=
\begin_inset Quotes srd
\end_inset
/
\end_inset
--datadir=
+-datarootdir=
\begin_inset Quotes srd
\end_inset
\begin_inset Quotes srd
\end_inset
-/sdcc/doc
+
+\backslash
+${datarootdir}/doc
\begin_inset Quotes srd
\end_inset
/
\end_inset
--disable-ucsim
+-host=i586-mingw32msvc
\backslash
\newline
/
\end_inset
--host=i586-mingw32msvc -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
-build=unknown-unknown-linux-gnu
\layout Standard
./configure -C
\backslash
-\newline
-CFLAGS=
-\begin_inset Quotes srd
-\end_inset
-
--mno-cygwin -O2
-\begin_inset Quotes srd
-\end_inset
-
-
-\backslash
-
-\newline
-LDFLAGS=
-\begin_inset Quotes srd
-\end_inset
-
--mno-cygwin
-\begin_inset Quotes srd
-\end_inset
-
-
-\backslash
-
\newline
-
\begin_inset ERT
/
\end_inset
--datadir=
+-datarootdir=
\begin_inset Quotes srd
\end_inset
\begin_inset Quotes srd
\end_inset
-/sdcc/doc
+
+\backslash
+${datarootdir}/doc
\begin_inset Quotes srd
\end_inset
\backslash
\newline
--
-\begin_inset ERT
-status Collapsed
+CC=
+\begin_inset Quotes srd
+\end_inset
-\layout Standard
+gcc -mno-cygwin
+\begin_inset Quotes srd
+\end_inset
+
\backslash
-/
+
+\newline
+CXX=
+\begin_inset Quotes srd
\end_inset
--disable-ucsim
+g++ -mno-cygwin
+\begin_inset Quotes srd
+\end_inset
+
+
\layout Standard
'configure' is quite slow on Cygwin (at least on windows before Win2000/XP).
However if options are changed, it can be necessary to delete the config.cache
file.
\layout Section
-
+\added_space_bottom medskip
Install paths
\begin_inset LatexCommand \label{sub:Install-paths}
\layout Standard
-\added_space_top medskip \align center
+\align center
\begin_inset Tabular
<lyxtabular version="3" rows="5" columns="4">
\newline
-\layout Comment
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
Don't delete any of the stray spaces in the table above without checking
the HTML output (last line)!
+\end_inset
+
+
\layout Standard
\SpecialChar ~
See section 'Configure Options'.
\layout Subsection
-Building SDCC on Windows
-\layout Standard
-
-With the exception of Cygwin the SDCC binaries uCsim and sdcdb can't be
- built on Windows.
- They use Unix-sockets, which are not available on Win32.
-\layout Subsection
-
Building SDCC using Cygwin and Mingw32
\layout Standard
\series default
SDCC is distributed with all the projects, workspaces, and files you need
- to build it using Visual C++ 6.0/NET (except for sdcdb.exe which currently
- doesn't build under MSVC).
+ to build it using Visual C++ 6.0/NET (except for SDCDB and ucSim).
The workspace name is 'sdcc.dsw'.
Please note that as it is now, all the executables are created in a folder
called sdcc
From the sdcc directory, run the command "make -f Makefile.bcc".
This should regenerate all the .exe files in the bin directory except for
- sdcdb.exe (which currently doesn't build under Borland C++).
+ SDCDB and ucSim.
\layout Enumerate
If you modify any source files and need to rebuild, be aware that the dependenci
\layout Section
Reading the Documentation
+\begin_inset LatexCommand \index{Documentation}
+
+\end_inset
+
+
\layout Standard
Currently reading the document in pdf format is recommended, as for unknown
\layout Itemize
s51 - The ucSim 8051 simulator.
- Not available on Win32 platforms.
\layout Itemize
sdcdb - The source debugger.
- Not available on Win32 platforms.
\layout Itemize
packihx - A tool to pack (compress) Intel hex files.
\end_inset
- is a modified version of the GNU preprocessor.
+ is a modified version of the GNU cpp
+\begin_inset LatexCommand \index{cpp|see{sdcpp}}
+
+\end_inset
+
+ preprocessor
+\begin_inset LatexCommand \url{http://gcc.gnu.org/}
+
+\end_inset
+
+.
The C preprocessor is used to pull in #include sources, process #ifdef
statements, #defines and so on.
\layout Subsection
.
It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
XA51 family.
- S51 is currently not available on Win32 platfors.
\layout Subsection
sdcdb - Source Level Debugger
\layout Standard
-Sdcdb
-\begin_inset LatexCommand \index{sdcdb (debugger)}
+SDCDB
+\begin_inset LatexCommand \index{SDCDB (debugger)}
\end_inset
is the companion source level debugger.
- More about sdcdb in section
+ More about SDCDB in section
\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
\end_inset
\end_inset
, but can be easily changed to use other simulators.
- Sdcdb is currently not available on Win32 platfors.
\layout Chapter
Using SDCC
- An intermediate file containing debug information needed to create the
.cdb file (with -
\begin_inset ERT
-status Open
+status Collapsed
\layout Standard
).
\layout Subsection
-Projects with Multiple Source Files
-\layout Standard
+Postprocessing the Intel Hex
+\begin_inset LatexCommand \index{Intel hex format}
-SDCC can compile only ONE file at a time.
- Let us for example assume that you have a project containing the following
- files:
-\newline
+\end_inset
-\newline
-foo1.c (contains some functions)
-\newline
-foo2.c (contains some more functions)
-\newline
-foomain.c (contains more functions and the function main)
-\newline
+ file
+\layout Standard
-\size footnotesize
+In most cases this won't be needed but the Intel Hex file
+\begin_inset LatexCommand \index{<file>.ihx}
-\newline
+\end_inset
-\size default
-The first two files will need to be compiled separately with the commands:
-\size footnotesize
+ which is generated by SDCC might include lines of varying length and the
+ addresses within the file are not guaranteed to be strictly ascending.
+ If your toolchain or a bootloader does not like this you can use the tool
-\size default
+\family typewriter
+packihx
+\family default
-\newline
+\begin_inset LatexCommand \index{packihx (tool)}
-\newline
+\end_inset
-\family sans
-\series bold
-sdcc\SpecialChar ~
--c\SpecialChar ~
-foo1.c
-\family default
-\series default
-\size footnotesize
+ which is part of the SDCC distribution:
+\newline
\newline
\family sans
\series bold
-\size default
-sdcc\SpecialChar ~
--c\SpecialChar ~
-foo2.c
+ packihx sourcefile.ihx >sourcefile.hex
\family default
\series default
\newline
\newline
-Then compile the source file containing the
+The separately available
\emph on
-main()
+ srecord
\emph default
- function and link
-\begin_inset LatexCommand \index{Linker}
+
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
\end_inset
- the files together with the following command:
+ package additionally allows to set undefined locations to a predefined
+ value, to insert checksums
+\begin_inset LatexCommand \index{checksum}
+
+\end_inset
+
+ of various flavours (crc, add, xor) and to perform other manipulations
+ (convert, split, crop, offset, ...).
+
\newline
\newline
\family sans
\series bold
-sdcc\SpecialChar ~
-foomain.c\SpecialChar ~
-foo1.rel\SpecialChar ~
-foo2.rel
-\family default
-\series default
+srec_cat\SpecialChar ~
+\SpecialChar ~
+sourcefile.ihx -intel\SpecialChar ~
+\SpecialChar ~
+-o sourcefile.hex -intel
+\newline
+
+\newline
+
+\family default
+\series default
+An example for a more complex command line
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+the command backfills
+\begin_inset LatexCommand \index{backfill unused memory}
+
+\end_inset
+
+ unused memory with 0x12 and the overall 16 bit sum of the complete 64 kByte
+ block is zero.
+ If the program counter on an mcs51 runs wild the backfill pattern 0x12
+ will be interpreted as an
+\family typewriter
+lcall
+\family default
+ to address
+\family typewriter
+0x1212
+\family default
+ (where an emergency routine could sit).
+\end_inset
+
+ could look like:
+\newline
+
+\newline
+
+\family sans
+\series bold
+\size footnotesize
+srec_cat\SpecialChar ~
+sourcefile.ihx -intel\SpecialChar ~
+\SpecialChar ~
+-fill 0x12 0x0000 0xfffe\SpecialChar ~
+-little-endian-checksum-nega
+tive 0xfffe 0x02 0x02\SpecialChar ~
+\SpecialChar ~
+-o sourcefile.hex -intel
+\size default
+
+\newline
+
+\newline
+
+\family default
+\series default
+The srecord package is available at
+\begin_inset LatexCommand \url{http://sf.net/projects/srecord}
+
+\end_inset
+
+ .
+\layout Subsection
+
+Projects with Multiple Source Files
+\layout Standard
+
+SDCC can compile only ONE file at a time.
+ Let us for example assume that you have a project containing the following
+ files:
+\newline
+
+\newline
+foo1.c (contains some functions)
+\newline
+foo2.c (contains some more functions)
+\newline
+foomain.c (contains more functions and the function main)
+\newline
+
+\size footnotesize
+
+\newline
+
+\size default
+The first two files will need to be compiled separately with the commands:
+\size footnotesize
+
+\size default
+
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcc\SpecialChar ~
+-c\SpecialChar ~
+foo1.c
+\family default
+\series default
+\size footnotesize
+
+\newline
+
+\family sans
+\series bold
+\size default
+sdcc\SpecialChar ~
+-c\SpecialChar ~
+foo2.c
+\family default
+\series default
+
+\newline
+
+\newline
+Then compile the source file containing the
+\emph on
+main()
+\emph default
+ function and link
+\begin_inset LatexCommand \index{Linker}
+
+\end_inset
+
+ the files together with the following command:
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcc\SpecialChar ~
+foomain.c\SpecialChar ~
+foo1.rel\SpecialChar ~
+foo2.rel
+\family default
+\series default
\begin_inset LatexCommand \index{<file>.rel}
\newline
\layout Standard
-
+\added_space_bottom bigskip
If the source files are compiled using -
\begin_inset ERT
-status Open
+status Collapsed
\layout Standard
\end_inset
- processor (In development, not complete).
+ processor (Not maintained, not complete).
AVR users should probably have a look at winavr
\begin_inset LatexCommand \url{http://sourceforge.net/projects/winavr}
\end_inset
.
-\layout Comment
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
I think it is fair to direct users there for now.
Open source is also about avoiding unnecessary work .
But I didn't find the 'official' link.
+\end_inset
+
+
\layout List
\labelwidthstring 00.00.0000
-bit processors (p16f84 and variants.
In development, not complete).
-\layout Comment
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
p16f627 p16f628 p16f84 p16f873 p16f877?
+\end_inset
+
+
\layout List
\labelwidthstring 00.00.0000
processor (Not maintained, not complete).
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
\labelwidthstring 00.00.0000
+\series bold
+-pedantic-parse-number
+\begin_inset LatexCommand \index{-pedantic-parse-number}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Pedentic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly
+ and the macro LO_B(3) gets expanded.
+ See also #pragma pedantic_parse_number in section
+\begin_inset LatexCommand \ref{sec:Pragmas}
+
+\end_inset
+
+
+\emph on
+Note: this functionality is not in conformance with standard!
+\layout List
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
+
+
\series bold
-Wp\SpecialChar ~
preprocessorOption[,preprocessorOption]
\end_inset
.
- SDCC uses an adapted version of the preprocessor cpp of the GNU Compiler
- Collection (gcc), if you need more dedicated options please refer to the
- documentation at
+ SDCC uses an adapted version of the preprocessor
+\emph on
+cpp
+\emph default
+ of the GNU Compiler Collection
+\begin_inset LatexCommand \index{gcc (GNU Compiler Collection)}
+
+\end_inset
+
+ (
+\emph on
+gcc
+\emph default
+
+\begin_inset LatexCommand \url{http://gcc.gnu.org/}
+
+\end_inset
+
+), if you need more dedicated options please refer to the GCC\SpecialChar ~
+4.1.1\SpecialChar ~
+CPP\SpecialChar ~
+Manual
+ at
\begin_inset LatexCommand \htmlurl{http://www.gnu.org/software/gcc/onlinedocs/}
\end_inset
\end_inset
segment, default value 0.
- Note when this option is used the interrupt vector table is also relocated
- to the given address.
+ Note when this option is used the interrupt vector table
+\begin_inset LatexCommand \index{interrupt vector table}
+
+\end_inset
+
+ is also relocated to the given address.
The value entered can be in Hexadecimal or Decimal format, e.g.: -
\begin_inset ERT
status Collapsed
\end_inset
- is placed after the pdata segment.
+ is placed after the pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ segment.
Using this option the xstack can be placed anywhere in the external memory
space of the 8051.
The value entered can be in Hexadecimal or Decimal format, e.g.
\end_inset
+\begin_inset LatexCommand \index{HC08!Options!-\/-out-fmt-elf}
+
+\end_inset
+
+
\bar under
\series default
\end_inset
.
- (Currently only supported for the HC08 processors)
+ (Currently only supported for the HC08
+\begin_inset LatexCommand \index{HC08}
+
+\end_inset
+
+ processors)
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
...
Pass the linkOption to the linker.
- See file sdcc/as/doc/asxhtm.html for more on linker options.
+ If a bootloader is used an option like
+\begin_inset Quotes sld
+\end_inset
+
+-Wl\SpecialChar ~
+-bCSEG=0x1000
+\begin_inset Quotes srd
+\end_inset
+
+ would be typical to set the start of the code segment.
+ See also #pragma constseg and #pragma codeseg in section
+\begin_inset LatexCommand \ref{sec:Pragmas}
+
+\end_inset
+
+ .
+ File sdcc/as/doc/asxhtm.html has more on linker options.
\layout Subsection
MCS51 Options
\series default
- Uses a pseudo stack in the first 256 bytes in the external ram for allocating
- variables and passing parameters.
+ Uses a pseudo stack in the pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ area (usually the first 256 bytes in the external ram) for allocating variables
+ and passing parameters.
See section
\begin_inset LatexCommand \ref{sub:External-Stack}
data, idata and stack together.
This is the default now.
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
\end_inset
-\begin_inset LatexCommand \index{DS390 options}
+\begin_inset LatexCommand \index{DS390}
\end_inset
-model-flat24
\series default
-\begin_inset LatexCommand \index{-\/-model-flat24}
+\begin_inset LatexCommand \index{DS390!Options!-\/-model-flat24}
\end_inset
\end_inset
-protect-sp-update
-\begin_inset LatexCommand \index{-\/-protect-sp-update}
+\begin_inset LatexCommand \index{DS390!Options!-\/-protect-sp-update}
\end_inset
-stack-10bit
\series default
-\begin_inset LatexCommand \index{-\/-stack-10bit}
+\begin_inset LatexCommand \index{DS390!Options!-\/-stack-10bit}
\end_inset
\end_inset
-stack-probe
-\begin_inset LatexCommand \index{-\/-stack-probe}
+\begin_inset LatexCommand \index{DS390!Options!-\/-stack-probe}
\end_inset
\end_inset
-tini-libid
-\begin_inset LatexCommand \index{-\/-tini-libid}
+\begin_inset LatexCommand \index{DS390!Options!-\/-tini-libid}
\end_inset
<nnnn> LibraryID used in -mTININative.
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
\end_inset
-use-accelerator
-\begin_inset LatexCommand \index{-\/-use-accelerator}
+\begin_inset LatexCommand \index{DS390!Options!-\/-use-accelerator}
\end_inset
\end_inset
-\begin_inset LatexCommand \index{Z80 options}
+\begin_inset LatexCommand \index{Z80}
\end_inset
-callee-saves-bc
\series default
-\begin_inset LatexCommand \index{-\/-callee-saves-bc}
+\begin_inset LatexCommand \index{Z80!Options!-\/-callee-saves-bc}
\end_inset
\emph default
Force a called function to always save BC.
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
-no-std-crt0
\series default
-\begin_inset LatexCommand \index{-\/-no-std-crt0}
+\begin_inset LatexCommand \index{Z80!Options!-\/-no-std-crt0}
\end_inset
The compiler will optimize code generation towards fast code, possibly
at the expense of code size.
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-funsigned-char
+\begin_inset LatexCommand \index{-\/-funsigned-char}
+
+\end_inset
+
+
+\series default
+ The default signedness for every type is
+\family typewriter
+ signed
+\family default
+.
+ In some embedded environments the default signedness of
+\family typewriter
+ char
+\family default
+ is
+\family typewriter
+ unsigned
+\family default
+.
+ To set the signess for characters to unsigned, use the option --funsigned-char.
+ If this option is set and no signedness keyword (unsigned/signed) is given,
+ a char will be signed.
+ All other types are unaffected.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-
\begin_inset ERT
\series default
This option can be used if the code generated is called by a monitor program
or if the main routine includes an endless loop.
- This option might result in slightly smaller code and save two bytes of
- stack space.
+ This option results in slightly smaller code and saves two bytes of stack
+ space.
The return from the 'main'
\begin_inset LatexCommand \index{main return}
\series default
Display errors and warnings using MSVC style, so you can use SDCC with
- visual studio.
+ the visual studio IDE
+\begin_inset LatexCommand \index{IDE}
+
+\end_inset
+
+.
+ With SDCC both offering a GCC-like (the default) and a MSVC-like
+\begin_inset LatexCommand \index{MSVC output style}
+
+\end_inset
+
+ output style, integration into most programming editors should be straightforwa
+rd.
\layout List
\labelwidthstring 00.00.0000
\series bold
-more-pedantic
-\series default
- Actually this is
-\series bold
-\emph on
-not
-\series default
-\emph default
- a SDCC compiler option but if you want
-\emph on
-more
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-fdollars-in-identifiers
+\begin_inset LatexCommand \index{-\/-fdollars-in-identifiers}
+
+\end_inset
+
+
+\series default
+ Permit '$' as an identifier character
+\layout List
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
+
+
+\series bold
+more-pedantic
+\series default
+ Actually this is
+\series bold
+\emph on
+not
+\series default
+\emph default
+ a SDCC compiler option but if you want
+\emph on
+more
\emph default
warnings you can use a separate tool dedicated to syntax checking like
splint
\series default
Will create a dump of the live ranges of iTemp's
\layout List
-\labelwidthstring 00.00.0000
+\added_space_bottom bigskip \labelwidthstring 00.00.0000
\series bold
Redirecting output on Windows Shells
\layout Standard
-
+\added_space_bottom bigskip
By default SDCC writes it's error messages to
\begin_inset Quotes sld
\end_inset
..
\layout Standard
-
+\added_space_bottom bigskip
There are some more environment variables recognized by SDCC, but these
are solely used for debugging purposes.
They can change or disappear very quickly, and will never be documented.
\end_inset
+\begin_inset LatexCommand \index{sbit}
+
+\end_inset
+
+
\layout Standard
Like the bit keyword,
(0x80) P0;\SpecialChar ~
/* special function register P0 at location 0x80 */
\newline
-/* 16 bit special function register combination for timer 0 */
+
\newline
-/* with the high byte at location 0x8C and the low byte at location 0x8A
- */
+/* 16 bit special function register combination for timer 0
\newline
-__sfr16 __at
+\SpecialChar ~
+\SpecialChar ~
+ with the high byte at location 0x8C and the low byte at location 0x8A */
+\newline
+__sfr16 __at (0x8C8A) TMR0;
+\newline
+
+\newline
+__sbit __at
\begin_inset LatexCommand \index{at}
\end_inset
\end_inset
- (0x8C8A) TMR0;
-\newline
-__sbit __at (0xd7) CY; /* CY (Carry Flag
+ (0xd7) CY;\SpecialChar ~
+ /* CY (Carry Flag
\begin_inset LatexCommand \index{Flags}
\end_inset
\emph default
Allthough SDCC usually accesses them Least Significant Byte (LSB) first,
this is not guaranteed.
+\newline
+
+\layout Standard
+
+Please note, if you use a header file which was written for another compiler
+ then the sfr / sfr16 / sfr32 / sbit Storage Class extensions will most
+ likely be
+\emph on
+not
+\emph default
+compatible.
+ Specifically the syntax
+\family typewriter
+\SpecialChar ~
+sfr P0 = 0x80;\SpecialChar ~
+
+\family default
+ is compiled
+\emph on
+without warning
+\emph default
+ by SDCC to an assignment of 0x80 to a variable called P0
+\family typewriter
+
+\begin_inset Marginal
+collapsed true
+
+\layout Standard
+
+
+\series bold
+\SpecialChar ~
+!
+\end_inset
+
+.
+
+\family default
+Nevertheless it is possible to write header files
+\begin_inset LatexCommand \index{Header files}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Include files}
+
+\end_inset
+
+ which can be shared among different compilers (see section
+\begin_inset LatexCommand \ref{sec:Porting-code-to-other-compilers}
+
+\end_inset
+
+).
+
\layout Subsubsection
Pointers
\newline
\newline
-/* the following is a generic pointer physically located in xdata space
- */
+/* generic pointer physically located in xdata space */
\newline
-char * __xdata p;
+unsigned char * __xdata p;
\newline
\newline
-/* the following is a function pointer physically located in data space
- */
+/* generic pointer physically located in default memory space */
+\newline
+unsigned char * p;
+\newline
+
+\newline
+/* the following is a function pointer
+\begin_inset LatexCommand \index{function pointer}
+
+\end_inset
+
+ physically located in data space */
\newline
char (* __data fp)(void);
\layout Standard
\end_inset
routines.
- Explicitly specifying the pointer type will generate the most efficient
- code.
+ Explicitly specifying the pointer
+\begin_inset LatexCommand \index{pointer}
+
+\end_inset
+
+ type will generate the most efficient code.
\layout Subsubsection
Notes on MCS51 memory
If in doubt, don't specify any options and see if the resulting memory
layout is appropriate, then you can adjust it.
\layout Standard
-
+\added_space_bottom bigskip
The linker generates two files with memory allocation information.
The first, with extension .map
\begin_inset LatexCommand \index{<file>.map}
\layout Subsection
Z80/Z180 Storage Class
-\begin_inset LatexCommand \index{Storage class}
+\begin_inset LatexCommand \index{Z80!Storage class}
\end_inset
I/O memory
\begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
+\end_inset
+
+
+\begin_inset LatexCommand \index{Z80!I/O memory}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Z180!I/O memory}
+
\end_inset
is accessed with special instructions, e.g.:
\end_inset
/HD64180
-\begin_inset LatexCommand \index{HD64180}
+\begin_inset LatexCommand \index{HD64180 (see Z180)}
\end_inset
)
\layout Standard
-
+\added_space_bottom bigskip
The compiler option -
\begin_inset ERT
status Collapsed
/
\end_inset
--portmode=180 (80) and a compiler #pragma\SpecialChar ~
+-portmode
+\begin_inset LatexCommand \index{Z180!Options!-\/-portmode}
+
+\end_inset
+
+=180 (80) and a compiler #pragma\SpecialChar ~
portmode
-\begin_inset LatexCommand \index{\#pragma portmode}
+\begin_inset LatexCommand \index{Z180!Pragmas!\#pragma portmode}
\end_inset
-=z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
+ z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
ns
\family typewriter
in0/out0
\layout Subsection
HC08 Storage Class
-\begin_inset LatexCommand \index{Storage class}
+\begin_inset LatexCommand \index{HC08!Storage class}
\end_inset
The data storage class declares a variable that resides in the first 256
bytes of memory (the direct page).
- The HC08 is most efficient at accessing variables (especially pointers)
- stored here.
+ The HC08
+\begin_inset LatexCommand \index{HC08}
+
+\end_inset
+
+ is most efficient at accessing variables (especially pointers) stored here.
\layout Subsubsection
xdata
\layout Standard
-
+\added_space_bottom bigskip
The xdata storage class declares a variable that can reside anywhere in
memory.
This is the default if no storage class is specified.
\end_inset
- (0x7ffe) unsigned int chksum;
+ 0x7ffe unsigned int chksum;
\layout Standard
-or
+or, better conforming to ISO/IEC 9899 C:
\layout Verse
\SpecialChar ~
/* I/O port 1, bit 2 */
\layout Standard
-
+\added_space_bottom bigskip
and you can use the same hardware dependent routine without changes, as
for example in a library.
This is somehow similar to sbit, but only one absolute address has to be
It is however allowed to use bit parameters in reentrant functions and also
non-static local bit variables are supported.
Efficient use is limited to 8 semi-bitregisters in bit space.
- They are pushed and popped to stack as a single byte just like the normal
- registers.
+ They are pushed and popped to stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ as a single byte just like the normal registers.
\layout Section
Overlaying
\newline
}
\layout Standard
-
+\added_space_bottom bigskip
In the above example the parameter
\emph on
errcd
\emph default
keyword is the interrupt number this routine will service.
When present, the compiler will insert a call to this routine in the interrupt
- vector table for the interrupt number specified.
+ vector table
+\begin_inset LatexCommand \index{interrupt vector table}
+
+\end_inset
+
+ for the interrupt number specified.
If you have multiple source files in your project, interrupt service routines
can be present in any of them, but a prototype of the isr MUST be present
or included in the file that contains the function
main
\emph default
.
- The optional
+ The optional (8051 specific) keyword
\emph on
using
\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
\emph default
- keyword can be used to tell the compiler to use the specified register
- bank (8051 specific) when generating code for this function.
+ can be used to tell the compiler to use the specified register bank when
+ generating code for this function.
\newline
+Interrupt service routines open the door for some very interesting bugs:
+\layout Subsubsection
+
+
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-volatile}
+
+\end_inset
+Common interrupt pitfall: variable not declared
+\emph on
+volatile
\layout Standard
-Interrupt service routines open the door for some very interesting bugs:
-\newline
If an interrupt service routine changes variables which are accessed by
other functions these variables have to be declared
\emph on
\end_inset
.
-
+ See
+\begin_inset LatexCommand \url{http://en.wikipedia.org/wiki/Volatile_variable}
+
+\end_inset
+
+ .
+\layout Subsubsection
+
+
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-atomic}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+non-atomic access
\layout Standard
If the access to these variables is not
the processor needs more than one instruction for the access and could
be interrupted while accessing the variable) the interrupt must be disabled
during the access to avoid inconsistent data.
- Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs
- and should be protected by disabling interrupts.
+
+\newline
+Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs and
+ should be protected by disabling interrupts.
You're not automatically on the safe side if you use 8 bit variables though.
We need an example here: f.e.
on the 8051 the harmless looking
counter
\family default
is located in data memory.
- Bugs like these are hard to reproduce and can cause a lot of trouble.
+\newline
+Bugs like these are hard to reproduce and can cause a lot of trouble.
+\layout Subsubsection
+
+
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-stack-overflow}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+stack overflow
\layout Standard
The return address and the registers used in the interrupt service routine
subroutine when the stack is already in use for f.e.
many return addresses.
+\layout Subsubsection
+
+
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-reentrant}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+use of non-reentrant functions
\layout Standard
A special note here, int (16 bit) and long (32 bit) integer division
\end_inset
- operations are implemented using external support routines developed in
- ANSI-C.
+ operations are implemented using external support routines.
If an interrupt service routine needs to do any of these operations then
the support routines (as mentioned in a following section) will have to
be recompiled using the
\end_inset
compiler option.
- Note, the type promotion
+
+\newline
+Note, the type promotion
\begin_inset LatexCommand \index{type promotion}
\end_inset
- required by ANSI C can cause 16 bit routines to be used without the programmer
- being aware of it.
-
+ required by ANSI C can cause 16 bit routines to be used
+\begin_inset Marginal
+collapsed true
+
\layout Standard
+
+\series bold
+\SpecialChar ~
+!
+\end_inset
+
+ without the programmer being aware of it.
+ See f.e.
+ the cast
+\family typewriter
+(unsigned char)(tail-1)
+\family default
+ within the if clause in section
+\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+
+\end_inset
+
+.
+\layout Standard
+\added_space_bottom bigskip
Calling other functions from an interrupt service routine is not recommended,
avoid it if possible.
Note that when some function is called from an interrupt service routine
\emph default
if all parameters are passed in registers.
\newline
-
-\newline
-Also see section
+ Also see section
\begin_inset LatexCommand \ref{sub:Overlaying}
\end_inset
MCS51/DS390 Interrupt Service Routines
\layout Standard
-Interrupt numbers and the corresponding address & descriptions for the Standard
- 8051/8052 are listed below.
- SDCC will automatically adjust the interrupt vector table to the maximum
- interrupt number specified.
+Interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ numbers and the corresponding address & descriptions for the Standard 8051/8052
+ are listed below.
+ SDCC will automatically adjust the
+\begin_inset LatexCommand \index{interrupt vector table}
+
+\end_inset
+
+ to the maximum interrupt number specified.
\newline
\layout Standard
This scheme may be advantageous for small interrupt service routines which
have low register usage.
\layout Standard
-
+\added_space_bottom bigskip
If the interrupt service routine is defined to be using a specific register
bank then only
\emph on
\emph default
& psw are saved and restored, if such an interrupt service routine calls
another function (using another register bank) then the entire register
- bank of the called function will be saved on the stack.
+ bank of the called function will be saved on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+.
This scheme is recommended for larger interrupt service routines.
\layout Subsection
-HC08 Interrupt Service Routines
+HC08
+\begin_inset LatexCommand \index{HC08}
+
+\end_inset
+
+ Interrupt Service Routines
\layout Standard
+\added_space_bottom bigskip
+Since the number of interrupts
+\begin_inset LatexCommand \index{HC08!interrupt}
+
+\end_inset
-Since the number of interrupts available is chip specific and the interrupt
- vector table always ends at the last byte of memory, the interrupt numbers
- corresponds to the interrupt vectors in reverse order of address.
+ available is chip specific and the interrupt vector table always ends at
+ the last byte of memory, the interrupt numbers corresponds to the interrupt
+ vectors in reverse order of address.
For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt
2 will use the interrupt vector at 0xfffa, and so on.
However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in
Z80 Interrupt Service Routines
\layout Standard
-The Z80 uses several different methods for determining the correct interrupt
+The Z80
+\begin_inset LatexCommand \index{Z80}
+
+\end_inset
+
+ uses several different methods for determining the correct interrupt
+\begin_inset LatexCommand \index{Z80!interrupt}
+
+\end_inset
+
vector depending on the hardware implementation.
Therefore, SDCC ignores the optional interrupt number and does not attempt
to generate an interrupt vector table.
\newline
}
\layout Standard
-
+\added_space_bottom bigskip
However if you need to create a non-interruptable interrupt service routine
you would also require the
\emph on
\end_inset
- (HC08):
+ (HC08
+\begin_inset LatexCommand \index{HC08!interrupt}
+
+\end_inset
+
+):
\layout Verse
\newline
\emph on
-(pending: I don't think this has been done yet)
+(pending: Note, nowadays the
+\emph default
+using
+\emph on
+ attribute has an effect on
+\emph default
+
+\emph on
+the generated code for a
+\emph default
+non-interrupt
+\emph on
+ function
+\emph default
+.
+\emph on
+)
\layout Standard
An
own: I suggest using the default bank zero and taking the small performance
hit.
\layout Standard
-
+\added_space_bottom bigskip
It is most efficient if your ISR calls no other functions.
If your ISR must call other functions, it is most efficient if those functions
use the same bank as the ISR (see note 1 below); the next best is if the
MCS51/DS390 Startup Code
\layout Standard
-The compiler inserts a call to the C routine
-\emph on
-_sdcc_external_startup()
-\begin_inset LatexCommand \index{\_sdcc\_external\_startup()}
+The compiler triggers the linker to link certain initialization modules
+ from the runtime library
+\begin_inset LatexCommand \index{Runtime library}
\end_inset
+ called crt<something>.
+ Only the necessary ones are linked, for instance crtxstack.asm (GSINIT1,
+ GSINIT5) is not linked unless the --xstack option is used.
+ These modules are highly entangled by the use of special segments/areas,
+ but a common layout is shown below:
+\layout Verse
+
+\family typewriter
\series bold
-\emph default
-
-\series default
-at the start of the CODE area.
- This routine is in the runtime library
-\begin_inset LatexCommand \index{Runtime library}
+\size footnotesize
+(main.asm)
+\layout Verse
-\end_inset
-
-.
- By default this routine returns 0, if this routine returns a non-zero value,
- the static & global variable initialization will be skipped and the function
- main will be invoked.
- Otherwise static & global variables will be initialized before the function
- main is invoked.
- You could add a
-\emph on
-_sdcc_external_startup()
-\emph default
- routine to your program to override the default if you need to setup hardware
- or perform some other critical operation prior to static & global variable
- initialization
-\begin_inset LatexCommand \index{Variable initialization}
-
-\end_inset
-
-.
- On some mcs51 variants xdata
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
-
-\end_inset
-
- memory has to be explicitly enabled before it can be accessed or if the
- watchdog needs to be disabled, this is the place to do it.
- The startup code clears all internal data memory, 256 bytes by default,
- but from 0 to n-1 if
-\emph on
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--iram-size
-\begin_inset LatexCommand \index{-\/-iram-size <Value>}
-
-\end_inset
-
-n
-\emph default
- is used.
- (recommended for Chipcon CC1010).
-\layout Standard
-
-See also the compiler option
-\emph on
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--no-xinit
-\emph default
--
-\emph on
-opt
-\emph default
-
-\begin_inset LatexCommand \index{-\/-no-xinit-opt}
-
-\end_inset
-
- and section
-\begin_inset LatexCommand \ref{sub:MCS51-variants}
-
-\end_inset
+\family typewriter
+\size footnotesize
\SpecialChar ~
-about MCS51-variants.
-\layout Subsection
-
-HC08 Startup Code
-\layout Standard
-
-The HC08 startup code follows the same scheme as the MCS51 startup code.
-\layout Subsection
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area HOME (CODE)
+\newline
+__interrupt_vect:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ljmp __sdcc_gsinit_startup
+\layout Verse
-Z80 Startup Code
-\layout Standard
-On the Z80 the startup code is inserted by linking with crt0.o which is generated
- from sdcc/device/lib/z80/crt0.s.
- If you need a different startup code you can use the compiler option
-\emph on
--
+\family typewriter
\series bold
-\emph default
-
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
-
-\series default
-\emph on
--no-std-crt0
-\emph default
-
-\begin_inset LatexCommand \index{-\/-no-std-crt0}
-
-\end_inset
-
- and provide your own crt0.o.
-
-\layout Section
-
-Inline Assembler Code
-\begin_inset LatexCommand \index{Assembler routines}
-
-\end_inset
-
-
-\layout Subsection
-
-A Step by Step Introduction
-\begin_inset LatexCommand \label{sub:A-Step-by Assembler Introduction}
-
-\end_inset
-
-
-\layout Standard
-
-Starting from a small snippet of c-code this example shows for the MCS51
- how to use inline assembly, access variables, a function parameter and
- an array in xdata memory.
- The example uses an MCS51 here but is easily adapted for other architectures.
- This is a buffer routine which should be optimized:
+\size footnotesize
+(crtstart.asm)
\layout Verse
\family typewriter
\size footnotesize
-unsigned char __far
-\begin_inset LatexCommand \index{far (storage class)}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_far (storage class)}
-
-\end_inset
-
- __at
-\begin_inset LatexCommand \index{at}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_at}
-
-\end_inset
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area GSINIT0 (CODE)
+\newline
+__sdcc_gsinit_startup::
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov sp,#__start__stack - 1
+\layout Verse
-(0x7f00) buf[0x100];
-\begin_inset LatexCommand \index{Aligned array}
-\end_inset
+\family typewriter
+\series bold
+\size footnotesize
+(crtxstack.asm)
+\layout Verse
+\family typewriter
+\size footnotesize
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area GSINIT1 (CODE)
\newline
-unsigned char head, tail;
-\newline
-
+__sdcc_init_xstack::
\newline
-void to_buffer( unsigned char c )
+; Need to initialize in GSINIT1 in case the user's __sdcc_external_startup
+ uses the xstack.
\newline
-{
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov __XPAGE,#(__start__xstack >> 8)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-if( head != (unsigned char)(tail-1) )\SpecialChar ~
-/* cast
-\series bold
-needed
-\series default
- to avoid promotion
-\begin_inset LatexCommand \index{promotion to signed int}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{type promotion}
-
-\end_inset
-
- to integer */
-\begin_inset Marginal
-collapsed false
-
-\layout Standard
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov _spx,#__start__xstack
+\layout Verse
+\family typewriter
\series bold
-\SpecialChar ~
-!
-\end_inset
+\size footnotesize
+(crtstart.asm)
+\layout Verse
-\newline
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-buf[ head++ ] = c;\SpecialChar ~
+.area GSINIT2 (CODE)
+\newline
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+lcall __sdcc_external_startup
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* access to a 256 byte aligned array */
-\newline
-}
-\layout Standard
-
-If the code snippet (assume it is saved in buffer.c) is compiled with SDCC
- then a corresponding buffer.asm file is generated.
- We define a new function
-\family typewriter
-to_buffer_asm()
-\family default
- in file buffer.c in which we cut and paste the generated code, removing
- unwanted comments and some ':'.
- Then add
-\begin_inset Quotes sld
-\end_inset
-
-_asm
-\begin_inset Quotes srd
-\end_inset
-
- and
-\begin_inset Quotes sld
-\end_inset
-
-_endasm;
-\begin_inset Quotes srd
-\end_inset
-
- to the beginning and the end of the function body:
-\layout Verse
-
-
-\family typewriter
-\size footnotesize
-/* With a cut and paste from the .asm file, we have something to start with.
+mov a,dpl
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-The function is not yet OK! (registers aren't saved) */
-\newline
-void to_buffer_asm( unsigned char c )
-\newline
-{
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+jz __sdcc_init_data
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_asm
-\begin_inset LatexCommand \index{\_asm}
-
-\end_inset
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ljmp __sdcc_program_startup
+\newline
+__sdcc_init_data:
+\layout Verse
-\begin_inset LatexCommand \index{\_\_asm}
-\end_inset
+\family typewriter
+\series bold
+\size footnotesize
+(crtxinit.asm)
+\layout Verse
-\newline
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-r2,dpl
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area GSINIT3 (CODE)
\newline
-;buffer.c if( head != (unsigned char)(tail-1) )
+__mcs51_genXINIT::
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-a,_tail
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+mov r1,#l_XINIT
+\newline
\SpecialChar ~
-dec\SpecialChar ~
\SpecialChar ~
-a
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-r3,a
-\newline
\SpecialChar ~
+mov a,r1
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-a,_head
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-cjne a,ar3,00106$
+orl a,#(l_XINIT >> 8)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ret
-\newline
-00106$:
-\newline
-;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
-\begin_inset LatexCommand \index{Aligned array}
-
-\end_inset
-
-
-\newline
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-r3,_head
+jz 00003$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-inc\SpecialChar ~
\SpecialChar ~
-_head
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+mov r2,#((l_XINIT+255) >> 8)
+\newline
+\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-dpl,r3
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
-dph,#(_buf >> 8)
+mov dptr,#s_XINIT
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
-\SpecialChar ~
-a,r2
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-movx @dptr,a
-\newline
-00103$:
+mov r0,#s_XISEG
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ret
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_endasm}
-
-\end_inset
-
-;
-\newline
-}
-\layout Standard
-
-The new file buffer.c should compile with only one warning about the unreferenced
- function argument 'c'.
- Now we hand-optimize the assembly code and insert an #define USE_ASSEMBLY
- (1) and finally have:
-\layout Verse
-
-
-\family typewriter
-\size footnotesize
-unsigned char __far __at(0x7f00) buf[0x100];
+mov __XPAGE,#(s_XISEG >> 8)
\newline
-unsigned char head, tail;
-\newline
-#define USE_ASSEMBLY (1)
-\newline
-
-\newline
-#if !USE_ASSEMBLY
-\newline
-
-\newline
-void to_buffer( unsigned char c )
-\newline
-{
+00001$:\SpecialChar ~
+clr a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-if( head != (unsigned char)(tail-1) )
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movc a,@a+dptr
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-buf[ head++ ] = c;
-\newline
-}
-\newline
-
-\newline
-#else
-\newline
-
-\newline
-void to_buffer( unsigned char c )
-\newline
-{
+movx @r0,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-c; // to avoid warning: unreferenced function argument
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_asm
-\begin_inset LatexCommand \index{\_asm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_asm}
-
-\end_inset
-
-
+inc dptr
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; save used registers here.
-
+inc r0
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; If we were still using r2,r3 we would have to push them here.
-
-\newline
-; if( head != (unsigned char)(tail-1) )
+cjne r0,#0,00002$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- a,_tail
+inc __XPAGE
+\newline
+00002$:\SpecialChar ~
+djnz r1,00001$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dec\SpecialChar ~
- a
+djnz r2,00001$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-xrl\SpecialChar ~
- a,_head
+mov __XPAGE,#0xFF
\newline
+00003$:
+\layout Verse
+
+
+\family typewriter
+\series bold
+\size footnotesize
+(crtclear.asm)
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; we could do an ANL a,#0x0f here to use a smaller buffer (see below)
+.area GSINIT4 (CODE)
+\newline
+__mcs51_genRAMCLEAR::
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-jz\SpecialChar ~
-\SpecialChar ~
- t_b_end$
+clr a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-;
+mov r0,#(l_IRAM-1)
\newline
-; buf[ head++ ] = c;
+00004$:\SpecialChar ~
+mov @r0,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- a,dpl \SpecialChar ~
+djnz r0,00004$
+\newline
+; _mcs51_genRAMCLEAR() end
+\layout Verse
+
+
+\family typewriter
+\series bold
+\size footnotesize
+(crtxclear.asm)
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; dpl holds lower byte of function argument
-\newline
\SpecialChar ~
\SpecialChar ~
+.area GSINIT4 (CODE)
+\newline
+__mcs51_genXRAMCLEAR::
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- dpl,_head \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; buf is 0x100 byte aligned so head can be used directly
+mov r0,#l_PSEG
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- dph,#(_buf>>8)
+mov a,r0
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-movx @dptr,a
+jz 00006$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-inc \SpecialChar ~
-_head
+mov r1,#s_PSEG
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; we could do an ANL _head,#0x0f here to use a smaller buffer (see above)
-\newline
-t_b_end$:
+mov __XPAGE,#(s_PSEG >> 8)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; restore used registers here
+clr a
+\newline
+00005$:\SpecialChar ~
+movx @r1,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_endasm}
-
-\end_inset
-
-;
-\newline
-}
-\newline
-#endif
-\layout Standard
-
-The inline assembler code can contain any valid code understood by the assembler
-, this includes any assembler directives and comment lines
-\begin_inset Foot
-collapsed false
-
-\layout Standard
-
-The assembler does not like some characters like ':' or ''' in comments.
- You'll find an 100+ pages assembler manual in sdcc/as/doc/asxhtm.html
-\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Assembler documentation}
-
-\end_inset
-
-
-\end_inset
-
-.
- The compiler does not do any validation of the code within the
-\family typewriter
-_asm
-\begin_inset LatexCommand \index{\_asm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_asm}
-
-\end_inset
-
- ...
- _endasm
-\size footnotesize
-
-\begin_inset LatexCommand \index{\_endasm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_endasm}
-
-\end_inset
-
-
-\size default
-;
-\family default
- keyword pair.
- Specifically it will not know which registers are used and thus register
- pushing/popping
-\begin_inset LatexCommand \index{push/pop}
-
-\end_inset
-
- has to be done manually.
-
-\layout Standard
-
-It is recommended that each assembly instruction (including labels) be placed
- in a separate line (as the example shows).
- When the -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--
-\emph on
-peep-asm
-\begin_inset LatexCommand \index{-\/-peep-asm}
-
-\end_inset
-
-
-\emph default
- command line option is used, the inline assembler code will be passed through
- the peephole optimizer
-\begin_inset LatexCommand \index{Peephole optimizer}
-
-\end_inset
-
-.
- There are only a few (if any) cases where this option makes sense, it might
- cause some unexpected changes in the inline assembler code.
- Please go through the peephole optimizer rules defined in file
-\emph on
-SDCCpeeph.def
-\emph default
- before using this option.
-\layout Subsection
-
-Naked Functions
-\begin_inset LatexCommand \label{sub:Naked-Functions}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Naked functions}
-
-\end_inset
-
-
-\layout Standard
-
-A special keyword may be associated with a function declaring it as
-\emph on
-_naked
-\begin_inset LatexCommand \index{\_naked}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_naked}
-
-\end_inset
-
-.
-
-\emph default
-The
-\emph on
-_naked
-\emph default
- function modifier attribute prevents the compiler from generating prologue
-\begin_inset LatexCommand \index{function prologue}
-
-\end_inset
-
- and epilogue
-\begin_inset LatexCommand \index{function epilogue}
-
-\end_inset
-
- code for that function.
- This means that the user is entirely responsible for such things as saving
- any registers that may need to be preserved, selecting the proper register
- bank, generating the
-\emph on
-return
-\emph default
- instruction at the end, etc.
- Practically, this means that the contents of the function must be written
- in inline assembler.
- This is particularly useful for interrupt functions, which can have a large
- (and often unnecessary) prologue/epilogue.
- For example, compare the code generated by these two functions:
-\layout Verse
-
-
-\family typewriter
-volatile
-\begin_inset LatexCommand \index{volatile}
-
-\end_inset
-
- data unsigned char counter;
-\newline
-
-\newline
-void simpleInterrupt(void) __interrupt
-\begin_inset LatexCommand \index{interrupt}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_interrupt}
-
-\end_inset
-
- (1)
-\newline
-{
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-counter++;
-\newline
-}
+inc r1
\newline
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+djnz r0,00005$
\newline
-void nakedInterrupt(void) __interrupt (2) __naked
+00006$:
\newline
-{
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov r0,#l_XSEG
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_asm
-\begin_inset LatexCommand \index{\_asm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_asm}
-
-\end_inset
-
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov a,r0
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-inc\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+orl a,#(l_XSEG >> 8)
+\newline
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_counter ; does not change flags, no need to save psw
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+jz 00008$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-reti\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+mov r1,#((l_XSEG + 255) >> 8)
+\newline
\SpecialChar ~
-; MUST explicitly include ret or reti in _naked function.
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov dptr,#s_XSEG
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_endasm}
-
-\end_inset
-
-;
-\newline
-}
-\layout Standard
-
-For an 8051 target, the generated simpleInterrupt looks like:
-\layout Verse
-
-
-\family typewriter
-Note, this is an
-\series bold
-outdated
-\series default
- example, recent versions of SDCC generate
-\newline
-the same code for simpleInterrupt() and nakedInterrupt()!
-\newline
-
-\newline
-_simpleInterrupt:
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-push\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-acc
+clr a
\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-push\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-b
+00007$:\SpecialChar ~
+movx @dptr,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-push\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dpl
+\SpecialChar ~
+inc dptr
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-push\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dph
+\SpecialChar ~
+djnz r0,00007$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-push\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-psw
+\SpecialChar ~
+djnz r1,00007$
\newline
+00008$:
+\layout Verse
+
+
+\family typewriter
+\series bold
+\size footnotesize
+(crtxstack.asm)
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-psw,#0x00
+.area GSINIT5 (CODE)
+\newline
+; Need to initialize in GSINIT5 because __mcs51_genXINIT modifies __XPAGE
+\newline
+; and __mcs51_genRAMCLEAR modifies _spx.
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-inc\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_counter
+mov __XPAGE,#(__start__xstack >> 8)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-psw
-\newline
+mov _spx,#__start__xstack
+\layout Verse
+
+
+\family typewriter
+\series bold
+\size footnotesize
+(application modules)
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dph
-\newline
+.area GSINIT (CODE)
+\layout Verse
+
+
+\family typewriter
+\series bold
+\size footnotesize
+(main.asm)
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dpl
+.area GSFINAL (CODE)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-b
+ljmp __sdcc_program_startup
+\newline
+;--------------------------------------------------------
+\newline
+; Home
+\newline
+;--------------------------------------------------------
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-acc
+.area HOME (CODE)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-reti
-\layout Standard
-
-whereas nakedInterrupt looks like:
-\layout Verse
-
-
-\family typewriter
-_nakedInterrupt:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
-inc\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_counter ; does not change flags, no need to save psw
+.area CSEG (CODE)
+\newline
+__sdcc_program_startup:
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-reti\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+lcall _main
+\newline
+; return from main will lock up
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; MUST explicitly include ret or reti in _naked function
+\SpecialChar ~
+sjmp .
\layout Standard
-The related directive #pragma exclude
-\begin_inset LatexCommand \index{\#pragma exclude}
-
-\end_inset
-
- allows a more fine grained control over pushing & popping
-\begin_inset LatexCommand \index{push/pop}
+One of these modules (crtstart.asm) contains a call to the C routine
+\emph on
+_sdcc_external_startup()
+\begin_inset LatexCommand \index{\_sdcc\_external\_startup()}
\end_inset
- the registers.
-\layout Standard
-While there is nothing preventing you from writing C code inside a
-\family typewriter
-_naked
-\family default
- function, there are many ways to shoot yourself in the foot doing this,
- and it is recommended that you stick to inline assembler.
-\layout Subsection
+\series bold
+\emph default
+
+\series default
+at the start of the CODE area.
+ This routine is also in the runtime library
+\begin_inset LatexCommand \index{Runtime library}
-Use of Labels within Inline Assembler
-\layout Standard
+\end_inset
-SDCC allows the use of in-line assembler with a few restrictions regarding
- labels.
- In older versions of the compiler all labels defined within inline assembler
- code
-\emph on
-had to be
-\emph default
- of the form
-\emph on
-nnnnn$
-\emph default
- where nnnn is a number less than 100 (which implies a limit of utmost 100
- inline assembler labels
+ and returns 0 by default.
+ If this routine returns a non-zero value, the static & global variable
+ initialization will be skipped and the function main will be invoked.
+ Otherwise static & global variables will be initialized before the function
+ main is invoked.
+ You could add an
\emph on
-per function
+_sdcc_external_startup()
\emph default
-\noun on
-)
-\noun default
-.
-
-\layout Verse
+ routine to your program to override the default if you need to setup hardware
+ or perform some other critical operation prior to static & global variable
+ initialization
+\begin_inset LatexCommand \index{Variable initialization}
+\end_inset
-\family typewriter
-_asm
-\begin_inset LatexCommand \index{\_asm}
+.
+ On some mcs51 variants xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
\end_inset
-
-\begin_inset LatexCommand \index{\_\_asm}
+ memory has to be explicitly enabled before it can be accessed or if the
+ watchdog
+\begin_inset LatexCommand \index{watchdog}
\end_inset
-
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-b,#10
-\newline
-00001$:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-djnz\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-b,00001$
-\newline
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
+ needs to be disabled, this is the place to do it.
+ The startup code clears all internal data memory, 256 bytes by default,
+ but from 0 to n-1 if
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-\end_inset
+\layout Standard
+\backslash
+/
+\end_inset
-\begin_inset LatexCommand \index{\_\_endasm}
+-iram-size
+\begin_inset LatexCommand \index{-\/-iram-size <Value>}
\end_inset
- ;
+n
+\emph default
+ is used.
+ (recommended for Chipcon CC1010).
\layout Standard
+\added_space_bottom bigskip
+See also the compiler options
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-Inline assembler code cannot reference any C-Labels, however it can reference
- labels
-\begin_inset LatexCommand \index{Labels}
+\layout Standard
+\backslash
+/
\end_inset
- defined by the inline assembler, e.g.:
-\layout Verse
-
-
-\family typewriter
-foo() {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-/* some c code */
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_asm
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-; some assembler code
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-ljmp $0003
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_endasm;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-/* some more c code */
-\newline
-clabel:\SpecialChar ~
-\SpecialChar ~
-/* inline assembler cannot reference this label */
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_asm
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-$0003: ;label (can be referenced by inline assembler only)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
+-no-xinit
+\emph default
+-
+\emph on
+opt
+\emph default
+
+\begin_inset LatexCommand \index{-\/-no-xinit-opt}
\end_inset
+,
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-\begin_inset LatexCommand \index{\_\_endasm}
+\layout Standard
+\backslash
+/
\end_inset
- ;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-/* some more c code */
-\newline
-}
-\layout Standard
-
-In other words inline assembly code can access labels defined in inline
- assembly within the scope of the function.
- The same goes the other way, i.e.
- labels defines in inline assembly can not be accessed by C statements.
-\layout Section
+-main-return
+\emph default
-Interfacing with Assembler Code
-\begin_inset LatexCommand \index{Assembler routines}
+\begin_inset LatexCommand \index{-\/-main-return}
\end_inset
+ and section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
+
+\end_inset
+ about MCS51-variants.
\layout Subsection
-Global Registers used for Parameter Passing
-\begin_inset LatexCommand \index{Parameter passing}
+HC08 Startup Code
+\layout Standard
+\added_space_bottom bigskip
+The HC08
+\begin_inset LatexCommand \index{HC08}
\end_inset
+ startup code follows the same scheme as the MCS51 startup code.
+\layout Subsection
+Z80 Startup Code
\layout Standard
-
-The compiler always uses the global registers
-\emph on
-DPL, DPH
-\begin_inset LatexCommand \index{DPTR, DPH, DPL}
+\added_space_bottom bigskip
+On the Z80
+\begin_inset LatexCommand \index{Z80}
\end_inset
+ the startup code is inserted by linking with crt0.o which is generated from
+ sdcc/device/lib/z80/crt0.s.
+ If you need a different startup code you can use the compiler option
+\emph on
+-
+\series bold
+\emph default
+
+\begin_inset ERT
+status Collapsed
-\begin_inset LatexCommand \index{DPTR}
+\layout Standard
+\backslash
+/
\end_inset
-, B
-\begin_inset LatexCommand \index{B (mcs51, ds390 register)}
+
+\series default
+\emph on
+-no-std-crt0
+\emph default
+
+\begin_inset LatexCommand \index{-\/-no-std-crt0}
\end_inset
+ and provide your own crt0.o.
-\emph default
-and
-\emph on
- ACC
-\begin_inset LatexCommand \index{ACC (mcs51, ds390 register)}
+\layout Section
+
+Inline Assembler Code
+\begin_inset LatexCommand \index{Assembler routines}
\end_inset
-\emph default
- to pass the first parameter to a routine.
- The second parameter onwards is either allocated on the stack (for reentrant
- routines or if -
-\begin_inset ERT
-status Collapsed
+\layout Subsection
-\layout Standard
+A Step by Step Introduction
+\begin_inset LatexCommand \label{sub:A-Step-by Assembler Introduction}
-\backslash
-/
\end_inset
--stack-auto is used) or in data / xdata memory (depending on the memory
- model).
-
-\layout Subsection
-Assembler Routine (non-reentrant)
\layout Standard
-In the following example
-\begin_inset LatexCommand \index{reentrant}
+Starting from a small snippet of c-code this example shows for the MCS51
+ how to use inline assembly, access variables, a function parameter and
+ an array in xdata memory.
+ The example uses an MCS51 here but is easily adapted for other architectures.
+ This is a buffer routine which should be optimized:
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
+unsigned char __far
+\begin_inset LatexCommand \index{far (storage class)}
\end_inset
-\begin_inset LatexCommand \index{Assembler routines (non-reentrant)}
+\begin_inset LatexCommand \index{\_\_far (storage class)}
\end_inset
- the function c_func calls an assembler routine asm_func, which takes two
- parameters
-\begin_inset LatexCommand \index{function parameter}
+ __at
+\begin_inset LatexCommand \index{at}
\end_inset
-.
-\layout Verse
+\begin_inset LatexCommand \index{\_\_at}
-\family typewriter
-extern int asm_func(unsigned char, unsigned char);
-\newline
-
-\newline
-int c_func (unsigned char i, unsigned char j)
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-return asm_func(i,j);
-\newline
-}
-\newline
+\end_inset
-\newline
-int main()
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-return c_func(10,9);
-\newline
-}
-\layout Standard
+(0x7f00) buf[0x100];
+\begin_inset LatexCommand \index{Aligned array}
-The corresponding assembler function is:
-\layout Verse
+\end_inset
-\family typewriter
-.globl _asm_func_PARM_2
\newline
+unsigned char head, tail;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-.globl _asm_func
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-.area OSEG
-\newline
-_asm_func_PARM_2:
+/* if interrupts
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ are involved see
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-.ds 1
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-.area CSEG
-\newline
-_asm_func:
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-a,dpl
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-add\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-a,_asm_func_PARM_2
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-dpl,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-dph
-\begin_inset LatexCommand \index{DPTR, DPH, DPL}
+section
+\begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
\end_inset
-,#0x00
+ about
+\series bold
+ volatile
+\series default
+ */
+\newline
+
+\newline
+void to_buffer( unsigned char c )
+\newline
+{
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-ret
-\layout Standard
-
-Note here that the return values
-\begin_inset LatexCommand \index{return value}
-
-\end_inset
-
- are placed in 'dpl' - One byte return value, 'dpl' LSB & 'dph' MSB for
- two byte values.
- 'dpl', 'dph' and 'b' for three byte values (generic pointers) and 'dpl','dph','
-b' & 'acc' for four byte values.
-\layout Standard
-
-The parameter naming convention is _<function_name>_PARM_<n>, where n is
- the parameter number starting from 1, and counting from the left.
- The first parameter is passed in
-\begin_inset Quotes eld
-\end_inset
-
-dpl
-\begin_inset Quotes erd
-\end_inset
-
- for a one byte parameter,
-\begin_inset Quotes eld
-\end_inset
-
-dptr
-\begin_inset Quotes erd
-\end_inset
+if( head != (unsigned char)(tail-1) )\SpecialChar ~
+/* cast
+\series bold
+needed
+\series default
+ to avoid promotion
+\begin_inset LatexCommand \index{promotion to signed int}
- for two bytes,
-\begin_inset Quotes eld
\end_inset
-b,dptr
-\begin_inset Quotes erd
-\end_inset
- for three bytes and
-\begin_inset Quotes eld
-\end_inset
+\begin_inset LatexCommand \index{type promotion}
-acc,b,dptr
-\begin_inset Quotes erd
\end_inset
- for a four bytes parameter.
- The variable name for the second parameter will be _<function_name>_PARM_2.
-\newline
+ to integer */
+\begin_inset Marginal
+collapsed true
-\newline
-Assemble the assembler routine with the following command:
-\newline
+\layout Standard
-\newline
-\family sans
\series bold
-asx8051 -losg asmfunc.asm
-\newline
+\SpecialChar ~
+!
+\end_inset
-\newline
-\family default
-\series default
-Then compile and link the assembler routine to the C source file with the
- following command:
\newline
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+buf[ head++ ] = c;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* access to a 256 byte aligned array */
\newline
-
-\family sans
-\series bold
-sdcc cfunc.c asmfunc.rel
-\layout Subsection
-
-Assembler Routine (reentrant)
+}
\layout Standard
-In this case
-\begin_inset LatexCommand \index{reentrant}
-
+If the code snippet (assume it is saved in buffer.c) is compiled with SDCC
+ then a corresponding buffer.asm file is generated.
+ We define a new function
+\family typewriter
+to_buffer_asm()
+\family default
+ in file buffer.c in which we cut and paste the generated code, removing
+ unwanted comments and some ':'.
+ Then add
+\begin_inset Quotes sld
\end_inset
-
-\begin_inset LatexCommand \index{Assembler routines (reentrant)}
-
+_asm
+\begin_inset Quotes srd
\end_inset
- the second parameter
-\begin_inset LatexCommand \index{function parameter}
+ and
+\begin_inset Quotes sld
+\end_inset
+_endasm;
+\begin_inset Quotes srd
\end_inset
- onwards will be passed on the stack, the parameters are pushed from right
- to left i.e.
- after the call the leftmost parameter will be on the top of the stack.
- Here is an example:
+ to the beginning and the end of the function body:
\layout Verse
\family typewriter
-extern int asm_func(unsigned char, unsigned char);
+\size footnotesize
+/* With a cut and paste from the .asm file, we have something to start with.
\newline
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+The function is not yet OK! (registers aren't saved) */
\newline
-int c_func (unsigned char i, unsigned char j) reentrant
+void to_buffer_asm( unsigned char c )
\newline
{
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-return asm_func(i,j);
-\newline
-}
-\newline
+_asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_asm}
+
+\end_inset
+
-\newline
-int main()
-\newline
-{
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-return c_func(10,9);
+mov\SpecialChar ~
+\SpecialChar ~
+r2,dpl
\newline
-}
-\layout Standard
+;buffer.c if( head != (unsigned char)(tail-1) ) \SpecialChar ~
+/* cast
+\series bold
+needed
+\series default
+ to avoid promotion
+\begin_inset LatexCommand \index{promotion to signed int}
-The corresponding assembler routine is:
-\layout Verse
+\end_inset
-\family typewriter
-.globl _asm_func
-\newline
-_asm_func:
+\begin_inset LatexCommand \index{type promotion}
+
+\end_inset
+
+ to integer */
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-push _bp
+mov\SpecialChar ~
+\SpecialChar ~
+a,_tail
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov _bp,sp
+dec\SpecialChar ~
+\SpecialChar ~
+a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov r2,dpl
+mov\SpecialChar ~
+\SpecialChar ~
+r3,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov a,_bp
+mov\SpecialChar ~
+\SpecialChar ~
+a,_head
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-add a,#0xfd
+cjne a,ar3,00106$
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov r0,a
+ret
+\newline
+00106$:
+\newline
+;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
+\begin_inset LatexCommand \index{Aligned array}
+
+\end_inset
+
+
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-add a,#0xfc ;?
+mov\SpecialChar ~
+\SpecialChar ~
+r3,_head
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov r1,a
+inc\SpecialChar ~
+\SpecialChar ~
+_head
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov a,@r0
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+mov\SpecialChar ~
\SpecialChar ~
-add a,r2 ;?
+dpl,r3
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov dpl,a
+mov\SpecialChar ~
+\SpecialChar ~
+dph,#(_buf >> 8)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov dph,#0x00
+mov\SpecialChar ~
+\SpecialChar ~
+a,r2
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov sp,_bp
+movx @dptr,a
+\newline
+00103$:
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-pop _bp
+ret
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ret
-\layout Standard
-
-The compiling and linking procedure remains the same, however note the extra
- entry & exit linkage required for the assembler code, _bp is the stack
- frame pointer and is used to compute the offset into the stack for parameters
- and local variables.
-\layout Section
-
-int (16 bit)
-\begin_inset LatexCommand \index{int (16 bit)}
-
-\end_inset
-
- and long (32 bit)
-\begin_inset LatexCommand \index{long (32 bit)}
-
-\end_inset
-
- Support
-\layout Standard
-
-For signed & unsigned int (16 bit) and long (32 bit) variables, division,
- multiplication and modulus operations are implemented by support routines.
- These support routines are all developed in ANSI-C to facilitate porting
- to other MCUs, although some model specific assembler optimizations are
- used.
- The following files contain the described routines, all of them can be
- found in <installdir>/share/sdcc/lib.
-\newline
-
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="11" columns="2">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-
-\series bold
-Function
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-
-\series bold
-Description
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-_mulint.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-16 bit multiplication
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-_divsint.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
- signed 16 bit division (calls _divuint)
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
-_divuint.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
- unsigned 16 bit division
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_endasm}
-_modsint.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+;
+\newline
+}
\layout Standard
-signed 16 bit modulus (calls _moduint)
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+The new file buffer.c should compile with only one warning about the unreferenced
+ function argument 'c'.
+ Now we hand-optimize the assembly code and insert an #define USE_ASSEMBLY
+ (1) and finally have:
+\layout Verse
-_moduint.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\family typewriter
+\size footnotesize
+unsigned char __far __at(0x7f00) buf[0x100];
+\newline
+unsigned char head, tail;
+\newline
+#define USE_ASSEMBLY (1)
+\newline
-unsigned 16 bit modulus
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
+#if !USE_ASSEMBLY
+\newline
-\layout Standard
+\newline
+void to_buffer( unsigned char c )
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+if( head != (unsigned char)(tail-1) )
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+buf[ head++ ] = c;
+\newline
+}
+\newline
-_mullong.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\newline
+#else
+\newline
-\layout Standard
+\newline
+void to_buffer( unsigned char c )
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+c; // to avoid warning: unreferenced function argument
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_asm
+\begin_inset LatexCommand \index{\_asm}
-32 bit multiplication
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-_divslong.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_asm}
- signed 32 division (calls _divulong)
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-_divulong.c
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; save used registers here.
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; If we were still using r2,r3 we would have to push them here.
+
+\newline
+; if( head != (unsigned char)(tail-1) )
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ a,_tail
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dec\SpecialChar ~
+ a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+xrl\SpecialChar ~
+ a,_head
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; we could do an ANL a,#0x0f here to use a smaller buffer (see below)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+jz\SpecialChar ~
+\SpecialChar ~
+ t_b_end$
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+;
+\newline
+; buf[ head++ ] = c;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ a,dpl \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; dpl holds lower byte of function argument
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ dpl,_head \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; buf is 0x100 byte aligned so head can be used directly
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ dph,#(_buf>>8)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movx @dptr,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+inc \SpecialChar ~
+_head
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; we could do an ANL _head,#0x0f here to use a smaller buffer (see above)
+\newline
+t_b_end$:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; restore used registers here
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-unsigned 32 division
+\begin_inset LatexCommand \index{\_\_endasm}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+;
+\newline
+}
+\newline
+#endif
\layout Standard
-_modslong.c
+The inline assembler code can contain any valid code understood by the assembler
+, this includes any assembler directives and comment lines.
+ The assembler does not like some characters like ':' or ''' in comments.
+ You'll find an 100+ pages assembler manual in sdcc/as/doc/asxhtm.html
+\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
- signed 32 bit modulus (calls _modulong)
+\begin_inset LatexCommand \index{Assembler documentation}
+
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ or online at
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
-_modulong.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\SpecialChar ~
+.
\layout Standard
-unsigned 32 bit modulus
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+The compiler does not do any validation of the code within the
+\family typewriter
+_asm
+\begin_inset LatexCommand \index{\_asm}
\end_inset
-\newline
+\begin_inset LatexCommand \index{\_\_asm}
-\layout Standard
+\end_inset
-Since they are compiled as
-\emph on
-non-reentrant
-\emph default
+ ...
+ _endasm
+\size footnotesize
-\begin_inset LatexCommand \index{reentrant}
+\begin_inset LatexCommand \index{\_endasm}
\end_inset
-, interrupt
-\begin_inset LatexCommand \index{interrupt}
+
+\begin_inset LatexCommand \index{\_\_endasm}
\end_inset
- service routines should not do any of the above operations.
- If this is unavoidable then the above routines will need to be compiled
- with the
-\emph on
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+\size default
+;
+\family default
+ keyword pair.
+ Specifically it will not know which registers are used and thus register
+ pushing/popping
+\begin_inset LatexCommand \index{push/pop}
\end_inset
+ has to be done manually.
+
+\layout Standard
-\emph default
- option, after which the source program will have to be compiled with
-\emph on
--
+It is recommended that each assembly instruction (including labels) be placed
+ in a separate line (as the example shows).
+ When the -
\begin_inset ERT
status Collapsed
/
\end_inset
--int-long-reent
-\begin_inset LatexCommand \index{-\/-int-long-reent}
+-
+\emph on
+peep-asm
+\begin_inset LatexCommand \index{-\/-peep-asm}
\end_inset
\emph default
- option.
- Notice that you don't have to call these routines directly.
- The compiler will use them automatically every time an integer operation
- is required.
-\layout Section
-
-Floating Point Support
-\begin_inset LatexCommand \index{Floating point support}
+ command line option is used, the inline assembler code will be passed through
+ the peephole optimizer
+\begin_inset LatexCommand \index{Peephole optimizer}
\end_inset
+.
+ There are only a few (if any) cases where this option makes sense, it might
+ cause some unexpected changes in the inline assembler code.
+ Please go through the peephole optimizer rules defined in file
+\emph on
+SDCCpeeph.def
+\emph default
+ before using this option.
+\layout Subsection
-\layout Standard
+Naked Functions
+\begin_inset LatexCommand \label{sub:Naked-Functions}
-SDCC supports IEEE (single precision 4 bytes) floating point numbers.The
- floating point support routines are derived from gcc's floatlib.c and consist
- of the following routines:
-\newline
+\end_inset
-\layout Standard
-\align center
-\size footnotesize
+\begin_inset LatexCommand \index{Naked functions}
+
+\end_inset
-\begin_inset Tabular
-<lyxtabular version="3" rows="17" columns="2">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
\layout Standard
+A special keyword may be associated with a function declaring it as
+\emph on
+_naked
+\begin_inset LatexCommand \index{\_naked}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-Function
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-Description
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_inset LatexCommand \index{\_\_naked}
-\layout Standard
+\end_inset
+.
+
+\emph default
+The
+\emph on
+_naked
+\emph default
+ function modifier attribute prevents the compiler from generating prologue
+\begin_inset LatexCommand \index{function prologue}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fsadd.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+ and epilogue
+\begin_inset LatexCommand \index{function epilogue}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-add floating point numbers
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ code for that function.
+ This means that the user is entirely responsible for such things as saving
+ any registers that may need to be preserved, selecting the proper register
+ bank, generating the
+\emph on
+return
+\emph default
+ instruction at the end, etc.
+ Practically, this means that the contents of the function must be written
+ in inline assembler.
+ This is particularly useful for interrupt functions, which can have a large
+ (and often unnecessary) prologue/epilogue.
+ For example, compare the code generated by these two functions:
+\layout Verse
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fssub.c
+\family typewriter
+volatile
+\begin_inset LatexCommand \index{volatile}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ data unsigned char counter;
+\newline
+\newline
+void simpleInterrupt(void) __interrupt
+\begin_inset LatexCommand \index{interrupt}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-subtract floating point numbers
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_interrupt}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fsdiv.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ (1)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+counter++;
+\newline
+}
+\newline
+\newline
+void nakedInterrupt(void) __interrupt (2) __naked
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_asm
+\begin_inset LatexCommand \index{\_asm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-divide floating point numbers
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_asm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fsmul.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+inc\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_counter ; does not change flags, no need to save psw
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+reti\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; MUST explicitly include ret or reti in _naked function.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-multiply floating point numbers
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2uchar.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+;
+\newline
+}
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to unsigned char
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+For an 8051 target, the generated simpleInterrupt looks like:
+\layout Verse
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2char.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+Note, this is an
+\emph on
+outdated
+\emph default
+ example, recent versions of SDCC generate
+\newline
+the
+\emph on
+same
+\emph default
+ code for simpleInterrupt() and nakedInterrupt()!
+\newline
+\newline
+_simpleInterrupt:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+acc
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+b
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dpl
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dph
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+psw
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+psw,#0x00
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+inc\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_counter
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+psw
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dph
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dpl
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+b
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+acc
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+reti
\layout Standard
+whereas nakedInterrupt looks like:
+\layout Verse
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to signed char
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2uint.c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+_nakedInterrupt:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+inc\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_counter ; does not change flags, no need to save psw
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+reti\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; MUST explicitly include ret or reti in _naked function
\layout Standard
+The related directive #pragma exclude
+\begin_inset LatexCommand \index{\#pragma exclude}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to unsigned int
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+ allows a more fine grained control over pushing & popping
+\begin_inset LatexCommand \index{push/pop}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2int.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ the registers.
\layout Standard
+While there is nothing preventing you from writing C code inside a
+\family typewriter
+_naked
+\family default
+ function, there are many ways to shoot yourself in the foot doing this,
+ and it is recommended that you stick to inline assembler.
+\layout Subsection
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to signed int
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
+Use of Labels within Inline Assembler
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2ulong.
-\family default
-\series default
-\shape default
-\size default
+SDCC allows the use of in-line assembler with a few restrictions regarding
+ labels.
+ In older versions of the compiler all labels defined within inline assembler
+ code
+\emph on
+had to be
\emph default
-\bar default
+ of the form
+\emph on
+nnnnn$
+\emph default
+ where nnnn is a number less than 100 (which implies a limit of utmost 100
+ inline assembler labels
+\emph on
+per function
+\emph default
+\noun on
+)
\noun default
-\color default
-c
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
+
+\layout Verse
-\layout Standard
+\family typewriter
+_asm
+\begin_inset LatexCommand \index{\_asm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to unsigned long
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_asm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_fs2long.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+b,#10
+\newline
+00001$:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+djnz\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+b,00001$
+\newline
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert floating point to signed long
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_uchar2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ ;
\layout Standard
+Inline assembler code cannot reference any C-Labels, however it can reference
+ labels
+\begin_inset LatexCommand \index{Labels}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert unsigned char to floating point
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+ defined by the inline assembler, e.g.:
+\layout Verse
+
+
+\family typewriter
+foo() {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* some c code */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_asm
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+; some assembler code
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ljmp $0003
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_endasm;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* some more c code */
+\newline
+clabel:\SpecialChar ~
+\SpecialChar ~
+/* inline assembler cannot reference this label */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_asm
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+$0003: ;label (can be referenced by inline assembler only)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_char2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{\_\_endasm}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert char to floating point number
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ ;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* some more c code */
+\newline
+}
\layout Standard
+In other words inline assembly code can access labels defined in inline
+ assembly within the scope of the function.
+ The same goes the other way, i.e.
+ labels defines in inline assembly can not be accessed by C statements.
+\layout Section
+
+Interfacing with Assembler Code
+\begin_inset LatexCommand \index{Assembler routines}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_uint2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\layout Subsection
+
+Global Registers used for Parameter Passing
+\begin_inset LatexCommand \index{Parameter passing}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert unsigned int to floating point
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
+The compiler always uses the global registers
+\emph on
+DPL, DPH
+\begin_inset LatexCommand \index{DPTR, DPH, DPL}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_int2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{DPTR}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert int to floating point numbers
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, B
+\begin_inset LatexCommand \index{B (mcs51, ds390 register)}
+\end_inset
+
+
+\emph default
+and
+\emph on
+ ACC
+\begin_inset LatexCommand \index{ACC (mcs51, ds390 register)}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_ulong2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\emph default
+ to pass the first parameter to a routine.
+ The second parameter onwards is either allocated on the stack (for reentrant
+ routines or if -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert unsigned long to floating point number
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-stack-auto is used) or in data / xdata memory (depending on the memory
+ model).
+
+\layout Subsection
+
+Assembler Routine (non-reentrant)
\layout Standard
+In the following example
+\begin_inset LatexCommand \index{reentrant}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-_long2fs.c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{Assembler routines (non-reentrant)}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-convert long to floating point number
\end_inset
-</cell>
-</row>
-</lyxtabular>
+
+ the function c_func calls an assembler routine asm_func, which takes two
+ parameters
+\begin_inset LatexCommand \index{function parameter}
\end_inset
+.
+\layout Verse
+
+
+\family typewriter
+extern int asm_func(unsigned char, unsigned char);
+\newline
+\newline
+int c_func (unsigned char i, unsigned char j)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return asm_func(i,j);
+\newline
+}
\newline
+\newline
+int main()
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return c_func(10,9);
+\newline
+}
\layout Standard
-These support routines are developed in ANSI-C so there is room for space
- and speed improvement
-\begin_inset Foot
-collapsed false
+The corresponding assembler function is:
+\layout Verse
-\layout Standard
-These floating point routines (
-\emph on
-not
-\emph default
- sinf(), cosf(), ...) for the mcs51 are implemented in assembler.
-
+\family typewriter
+.globl _asm_func_PARM_2
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.globl _asm_func
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area OSEG
+\newline
+_asm_func_PARM_2:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.ds 1
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+.area CSEG
+\newline
+_asm_func:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+a,dpl
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+a,_asm_func_PARM_2
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dpl,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dph
+\begin_inset LatexCommand \index{DPTR, DPH, DPL}
+
\end_inset
-.
- Note if all these routines are used simultaneously the data space might
- overflow.
- For serious floating point usage the large model might be needed.
- Also notice that you don't have to call this routines directly.
- The compiler will use them automatically every time a floating point operation
- is required.
-\layout Section
+,#0x00
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ret
+\layout Standard
-Library Routines
-\begin_inset LatexCommand \index{Libraries}
+Note here that the return values
+\begin_inset LatexCommand \index{return value}
\end_inset
-
+ are placed in 'dpl' - One byte return value, 'dpl' LSB & 'dph' MSB for
+ two byte values.
+ 'dpl', 'dph' and 'b' for three byte values (generic pointers) and 'dpl','dph','
+b' & 'acc' for four byte values.
\layout Standard
+The parameter naming convention is _<function_name>_PARM_<n>, where n is
+ the parameter number starting from 1, and counting from the left.
+ The first parameter is passed in
+\begin_inset Quotes eld
+\end_inset
-\emph on
-<pending: this is messy and incomplete - a little more information is in
- sdcc/doc/libdoc.txt
-\emph default
- >
-\layout Subsection
+dpl
+\begin_inset Quotes erd
+\end_inset
-Compiler support routines (_gptrget, _mulint etc.)
-\layout Subsection
+ for a one byte parameter,
+\begin_inset Quotes eld
+\end_inset
-Stdclib functions (puts, printf, strcat etc.)
-\layout Subsubsection
+dptr
+\begin_inset Quotes erd
+\end_inset
-<stdio.h>
-\layout Standard
+ for two bytes,
+\begin_inset Quotes eld
+\end_inset
+b,dptr
+\begin_inset Quotes erd
+\end_inset
-\begin_inset LatexCommand \index{<stdio.h>}
+ for three bytes and
+\begin_inset Quotes eld
+\end_inset
+acc,b,dptr
+\begin_inset Quotes erd
\end_inset
-As usual on embedded systems you have to provide your own
-\family typewriter
-getchar()
-\begin_inset LatexCommand \index{getchar()}
+ for a four bytes parameter.
+ The variable name for the second parameter will be _<function_name>_PARM_2.
+\newline
-\end_inset
+\newline
+Assemble the assembler routine with the following command:
+\newline
-
-\family default
-and
-\family typewriter
-putchar()
-\begin_inset LatexCommand \index{putchar()}
+\newline
-\end_inset
+\family sans
+\series bold
+asx8051 -losg asmfunc.asm
+\newline
+\newline
\family default
- routines.
- SDCC does not know whether the system connects to a serial line with or
- without handshake, LCD, keyboard or other device.
- And whether a
-\family typewriter
-lf
-\family default
- to
-\family typewriter
-crlf
-\family default
- conversion within
-\family typewriter
-putchar()
-\family default
- is intended.
- You'll find examples for serial routines f.e.
- in sdcc/device/lib.
-\layout Standard
-
-The default
-\family typewriter
- printf()
-\begin_inset LatexCommand \index{printf()}
-
-\end_inset
-
-
-\family default
-implementation in
-\family typewriter
- printf_large.c
-\family default
- does not support float (except on ds390).
- To enable this recompile it with the option
-\emph on
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
-DUSE_FLOATS=1
-\begin_inset LatexCommand \index{USE\_FLOATS}
-
-\end_inset
+\series default
+Then compile and link the assembler routine to the C source file with the
+ following command:
+\newline
+\newline
-\emph default
- on the command line.
- Use
-\emph on
- -
-\begin_inset ERT
-status Collapsed
+\family sans
+\series bold
+sdcc cfunc.c asmfunc.rel
+\layout Subsection
+Assembler Routine (reentrant)
\layout Standard
-\backslash
-/
-\end_inset
-
--model-large
-\begin_inset LatexCommand \index{-\/-model-large}
+In this case
+\begin_inset LatexCommand \index{reentrant}
\end_inset
-\emph default
- for the mcs51 port, since this uses a lot of memory.
-\layout Standard
-
-If you're short on memory you might want to use
-\family typewriter
-printf_small()
-\begin_inset LatexCommand \index{printf\_small()}
+\begin_inset LatexCommand \index{Assembler routines (reentrant)}
\end_inset
-
-\family default
-
-\emph on
-instead
-\emph default
- of
-\family typewriter
- printf().
-
-\family default
- For the mcs51 there additionally are assembly versions
-\family typewriter
-printf_tiny()
-\begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
+ the second parameter
+\begin_inset LatexCommand \index{function parameter}
\end_inset
+ onwards will be passed on the stack, the parameters are pushed from right
+ to left i.e.
+ after the call the leftmost parameter will be on the top of the stack.
+ Here is an example:
+\layout Verse
-\family default
- (subset of printf using less than 270 bytes) and
-\family typewriter
-printf_fast()
-\begin_inset LatexCommand \index{printf\_fast() (mcs51)}
-
-\end_inset
-
-\family default
-and
\family typewriter
- printf_fast_f()
-\begin_inset LatexCommand \index{printf\_fast\_f() (mcs51)}
-
-\end_inset
-
-
-\family default
- (floating-point aware version of printf_fast) which should fit the requirements
- of many embedded systems (printf_fast() can be customized by unsetting
- #defines to
-\emph on
-not
-\emph default
- support long variables and field widths).
-\layout Subsubsection
-
-<malloc.h>
-\begin_inset LatexCommand \index{malloc.h}
-
-\end_inset
+extern int asm_func(unsigned char, unsigned char);
+\newline
+\newline
+int c_func (unsigned char i, unsigned char j) reentrant
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return asm_func(i,j);
+\newline
+}
+\newline
+\newline
+int main()
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return c_func(10,9);
+\newline
+}
\layout Standard
-Before using dynamic
-\begin_inset LatexCommand \index{dynamic}
-
-\end_inset
-
- memory allocation with SDCC, you have to provide heap
-\begin_inset LatexCommand \index{heap}
-
-\end_inset
-
- space for malloc to allocate memory from
-\family typewriter
-.
-
-\family default
-You can acomplish this by including the following code into your source:
+The corresponding assembler routine is:
\layout Verse
\family typewriter
-#include <malloc.h>
-\begin_inset LatexCommand \index{malloc.h}
-
-\end_inset
-
- /* calloc
-\begin_inset LatexCommand \index{calloc}
-
-\end_inset
-
-, malloc
-\begin_inset LatexCommand \index{malloc}
-
-\end_inset
-
-, realloc
-\begin_inset LatexCommand \index{realloc}
-
-\end_inset
-
-, and free
-\begin_inset LatexCommand \index{free}
-
-\end_inset
-
- */
+.globl _asm_func
\newline
-
+_asm_func:
\newline
-#define HEAPSIZE 0x1000 /* Adjust depending on available memory */
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push _bp
\newline
-unsigned char xdata myheap[HEAPSIZE]; /* The actual heap for dynamic memory
- */
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov _bp,sp
\newline
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov r2,dpl
\newline
-void main (void)
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov a,_bp
\newline
-{
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add a,#0xfd
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* Your variable declarations come here*/
+\SpecialChar ~
+mov r0,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-...
+\SpecialChar ~
+add a,#0xfc ;?
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-init_dynamic_memory((MEMHEADER xdata *)myheap, HEAPSIZE);
+\SpecialChar ~
+mov r1,a
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-...
- /* Rest of your code*/
+\SpecialChar ~
+mov a,@r0
\newline
-}
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add a,r2 ;?
\newline
-
-\layout Subsection
-
-Math functions (sinf, powf, sqrtf etc.)
-\layout Subsubsection
-
-<math.h>
-\layout Standard
-
-See definitions in file <math.h>.
-\layout Subsection
-
-Other libraries
-\layout Standard
-
-Libraries
-\begin_inset LatexCommand \index{Libraries}
-
-\end_inset
-
- included in SDCC should have a license at least as liberal as the GNU Lesser
- General Public License
-\begin_inset LatexCommand \index{GNU Lesser General Public License, LGPL}
-
-\end_inset
-
-
-\emph on
-LGPL
-\emph default
-.
-\layout Comment
-
-license statements for the libraries are missing.
- sdcc/device/lib/ser_ir.c
-\layout Comment
-
-or _decdptr f.e.
- come with a GPL (as opposed to LGPL) License - this will not be liberal
- enough for many embedded programmers.
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov dpl,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov dph,#0x00
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov sp,_bp
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+pop _bp
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ret
\layout Standard
+\added_space_bottom bigskip
+The compiling and linking procedure remains the same, however note the extra
+ entry & exit linkage required for the assembler code, _bp is the stack
+ frame pointer and is used to compute the offset into the stack for parameters
+ and local variables.
+\layout Section
+
+int (16 bit)
+\begin_inset LatexCommand \index{int (16 bit)}
-If you have ported some library or want to share experience about some code
- which f.e.
- falls into any of these categories Busses (I
-\begin_inset Formula $^{\textrm{2}}$
\end_inset
-C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory
- cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel,
- Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
-\begin_inset LatexCommand \url{http://sourceforge.net/mail/?group_id=599}
+ and long (32 bit)
+\begin_inset LatexCommand \index{long (32 bit)}
\end_inset
-\SpecialChar ~
-would certainly like to hear about it.
- Programmers coding for embedded systems are not especially famous for being
- enthusiastic, so don't expect a big hurray but as the mailing list is searchabl
-e these references are very valuable.
- Let's help to create a climate where information is shared.
-\layout Section
+ Support
+\layout Standard
-Memory Models
-\layout Subsection
+For signed & unsigned int (16 bit) and long (32 bit) variables, division,
+ multiplication and modulus operations are implemented by support routines.
+ These support routines are all developed in ANSI-C to facilitate porting
+ to other MCUs, although some model specific assembler optimizations are
+ used.
+ The following files contain the described routines, all of them can be
+ found in <installdir>/share/sdcc/lib.
+\newline
-MCS51 Memory Models
-\begin_inset LatexCommand \index{Memory model}
+\layout Standard
+\align center
-\end_inset
+\begin_inset Tabular
+<lyxtabular version="3" rows="11" columns="2">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{MCS51 memory model}
+\series bold
+Function
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\layout Subsubsection
-Small, Medium and Large
-\layout Standard
+\series bold
+Description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-SDCC allows three memory models for MCS51 code,
-\shape slanted
-small, medium
-\shape default
- and
-\shape slanted
-large
-\shape default
-.
- Modules compiled with different memory models should
-\emph on
-never
-\emph default
- be combined together or the results would be unpredictable.
- The library routines supplied with the compiler are compiled as small,
- medium and large.
- The compiled library modules are contained in separate directories as small,
- medium and large so that you can link to the appropriate set.
\layout Standard
-When the medium or large model is used all variables declared without a
- storage class will be allocated into the external ram, this includes all
- parameters and local variables (for non-reentrant
-\begin_inset LatexCommand \index{reentrant}
-
+_mulint.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- functions).
- When the small model is used variables without storage class are allocated
- in the internal ram.
\layout Standard
-Judicious usage of the processor specific storage classes
-\begin_inset LatexCommand \index{Storage class}
-
+16 bit multiplication
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- and the 'reentrant' function type will yield much more efficient code,
- than using the large model.
- Several optimizations are disabled when the program is compiled using the
- large model, it is therefore recommended that the small model be used unless
- absolutely required.
-\layout Subsubsection
-
-External Stack
-\begin_inset LatexCommand \label{sub:External-Stack}
+\layout Standard
+_divsint.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{stack}
-
+ signed 16 bit division (calls _divuint)
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{External stack (mcs51)}
-
+_divuint.c
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The external stack (-
-\begin_inset ERT
-status Collapsed
+ unsigned 16 bit division
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+_modsint.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--xstack option
-\begin_inset LatexCommand \index{-\/-xstack}
+\layout Standard
+signed 16 bit modulus (calls _moduint)
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-) is located in pdata
-\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+\layout Standard
+_moduint.c
\end_inset
-
- memory (usually at the start of the external ram segment) and uses all
- unused space in pdata (max.
- 256 bytes).
- When -
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+unsigned 16 bit modulus
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--xstack option is used to compile the program, the parameters and local
- variables
-\begin_inset LatexCommand \index{local variables}
+\layout Standard
+_mullong.c
\end_inset
-
- of all reentrant functions are allocated in this area.
- This option is provided for programs with large stack space requirements.
- When used with the -
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+32 bit multiplication
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+\layout Standard
+_divslong.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- option, all parameters and local variables are allocated on the external
- stack (note: support libraries will need to be recompiled with the same
- options.
- There is a predefined target in the library makefile).
\layout Standard
-The compiler outputs the higher order address byte of the external ram segment
- into port P2
-\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
-
+ signed 32 division (calls _divulong)
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- (see also section
-\begin_inset LatexCommand \ref{sub:MCS51-variants}
+\layout Standard
+_divulong.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-), therefore when using the External Stack option, this port
-\emph on
-may not
-\emph default
- be used by the application program.
-\layout Subsection
-
-DS390 Memory Model
-\begin_inset LatexCommand \index{Memory model}
+\layout Standard
+unsigned 32 division
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{DS390 memory model}
+_modslong.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+ signed 32 bit modulus (calls _modulong)
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+_modulong.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The only model supported is Flat 24
-\begin_inset LatexCommand \index{Flat 24 (DS390 memory model)}
+unsigned 32 bit modulus
+\end_inset
+</cell>
+</row>
+</lyxtabular>
\end_inset
-.
- This generates code for the 24 bit contiguous addressing mode of the Dallas
- DS80C390 part.
- In this mode, up to four meg of external RAM or code space can be directly
- addressed.
- See the data sheets at www.dalsemi.com for further information on this part.
-\newline
\newline
-Note that the compiler does not generate any code to place the processor
- into 24 bitmode (although
-\emph on
-tinibios
-\emph default
- in the ds390 libraries will do that for you).
- If you don't use
+
+\layout Standard
+
+Since they are compiled as
\emph on
-tinibios
+non-reentrant
\emph default
-\begin_inset LatexCommand \index{Tinibios (DS390)}
+\begin_inset LatexCommand \index{reentrant}
\end_inset
-, the boot loader or similar code must ensure that the processor is in 24
- bit contiguous addressing mode before calling the SDCC startup code.
-\newline
+, interrupt
+\begin_inset LatexCommand \index{interrupt}
-\newline
-Like the
+\end_inset
+
+ service routines should not do any of the above operations.
+ If this is unavoidable then the above routines will need to be compiled
+ with the
\emph on
-
\begin_inset ERT
/
\end_inset
--model-large
-\emph default
- option, variables will by default be placed into the XDATA segment.
-
-\newline
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
-\newline
-Segments may be placed anywhere in the 4 meg address space using the usual
- -
+\end_inset
+
+
+\emph default
+ option, after which the source program will have to be compiled with
+\emph on
+-
\begin_inset ERT
status Collapsed
/
\end_inset
--*-loc options.
- Note that if any segments are located above 64K, the -r flag must be passed
- to the linker to generate the proper segment relocations, and the Intel
- HEX output format must be used.
- The -r flag can be passed to the linker by using the option
-\emph on
--Wl-r
-\emph default
- on the SDCC command line.
- However, currently the linker can not handle code segments > 64k.
-\layout Section
-
-Pragmas
-\begin_inset LatexCommand \index{Pragmas}
+-int-long-reent
+\begin_inset LatexCommand \index{-\/-int-long-reent}
\end_inset
-\layout Standard
-
-SDCC supports the following #pragma directives:
-\layout Itemize
+\emph default
+ option.
+ Notice that you don't have to call these routines directly.
+ The compiler will use them automatically every time an integer operation
+ is required.
+\layout Section
-save
-\begin_inset LatexCommand \index{\#pragma save}
+Floating Point Support
+\begin_inset LatexCommand \index{Floating point support}
\end_inset
- - this will save all current options to the save/restore stack.
- See #pragma\SpecialChar ~
-restore.
-\layout Itemize
-
-restore
-\begin_inset LatexCommand \index{\#pragma restore}
-\end_inset
+\layout Standard
- - will restore saved options from the last save.
- saves & restores can be nested.
- SDCC uses a save/restore stack: save pushes current options to the stack,
- restore pulls current options from the stack.
- See #pragma\SpecialChar ~
-save.
+SDCC supports IEEE (single precision 4 bytes) floating point numbers.
+ The floating point support routines are derived from gcc's floatlib.c and
+ consist of the following routines:
\newline
-\layout Itemize
+\layout Standard
+\align center
-callee_saves
-\begin_inset LatexCommand \index{\#pragma callee\_saves}
+\size footnotesize
-\end_inset
+\begin_inset Tabular
+<lyxtabular version="3" rows="17" columns="2">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{function prologue}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+Function
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- function1[,function2[,function3...]] - The compiler by default uses a caller
- saves convention for register saving across function calls, however this
- can cause unnecessary register pushing & popping
-\begin_inset LatexCommand \index{push/pop}
+\layout Standard
+Description
\end_inset
-
- when calling small functions from larger functions.
- This option can be used to switch off the register saving convention for
- the function names specified.
- The compiler will not save registers when calling these functions, extra
- code need to be manually inserted at the entry & exit for these functions
- to save & restore the registers used by these functions, this can SUBSTANTIALLY
- reduce code & improve run time performance of the generated code.
- In the future the compiler (with inter procedural analysis) may be able
- to determine the appropriate scheme to use for each function call.
- If -
-\begin_inset ERT
-status Collapsed
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--callee-saves command line option is used, the function names specified
- in #pragma\SpecialChar ~
-callee_saves
-\begin_inset LatexCommand \index{\#pragma callee\_saves}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fsadd.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- is appended to the list of functions specified in the command line.
-\layout Itemize
+\layout Standard
-exclude
-\begin_inset LatexCommand \index{\#pragma exclude}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+add floating point numbers
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables the generation
- of pairs of push/pop
-\begin_inset LatexCommand \index{push/pop}
+\layout Standard
-\end_inset
-
- instructions in
-\emph on
-I
-\emph default
-nterrupt
-\begin_inset LatexCommand \index{interrupt}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fssub.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-
-\emph on
-S
-\emph default
-ervice
-\emph on
-R
-\emph default
-outines.
- The directive should be placed immediately before the ISR function definition
- and it affects ALL ISR functions following it.
- To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
-exclude\SpecialChar ~
-none
-\begin_inset LatexCommand \index{\#pragma exclude}
-
-\end_inset
+\layout Standard
-.
- See also the related keyword _naked
-\begin_inset LatexCommand \index{\_naked}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+subtract floating point numbers
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{\_\_naked}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fsdiv.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-.
-\layout Itemize
+\layout Standard
-less_pedantic
-\begin_inset LatexCommand \index{\#pragma less\_pedantic}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+divide floating point numbers
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- - the compiler will not warn you anymore for obvious mistakes, you'r on
- your own now ;-(
-\layout Itemize
+\layout Standard
-disable_warning <nnnn>
-\begin_inset LatexCommand \index{\#pragma disable\_warning}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fsmul.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- - the compiler will not warn you anymore about warning number <nnnn>.
-\layout Itemize
+\layout Standard
-nogcse
-\begin_inset LatexCommand \index{\#pragma nogcse}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+multiply floating point numbers
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- - will stop global common subexpression elimination.
-\layout Itemize
+\layout Standard
-noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2uchar.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- - will stop loop induction optimizations.
-\layout Itemize
+\layout Standard
-noinvariant
-\begin_inset LatexCommand \index{\#pragma noinvariant}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to unsigned char
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
- - will not do loop invariant optimizations.
- For more details see Loop Invariants in section
-\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2char.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-.
-\layout Itemize
+\layout Standard
-noiv
-\begin_inset LatexCommand \index{\#pragma noiv}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to signed char
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- - Do not generate interrupt
-\begin_inset LatexCommand \index{interrupt}
+\layout Standard
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2uint.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
- vector table entries for all ISR functions defined after the pragma.
- This is useful in cases where the interrupt vector table must be defined
- manually, or when there is a secondary, manually defined interrupt vector
- table (e.g.
- for the autovector feature of the Cypress EZ-USB FX2).
- More elegantly this can be achieved by obmitting the optional interrupt
- number after the interrupt keyword, see section
-\begin_inset LatexCommand \ref{sub:Interrupt-Service-Routines}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to unsigned int
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\SpecialChar ~
-about interrupts.
-\layout Itemize
+\layout Standard
-nojtbound
-\begin_inset LatexCommand \index{\#pragma nojtbound}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2int.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- - will not generate code for boundary value checking, when switch statements
- are turned into jump-tables (dangerous).
- For more details see section
-\begin_inset LatexCommand \ref{sub:'switch'-Statements}
+\layout Standard
-\end_inset
-
-.
-\layout Itemize
-
-noloopreverse
-\begin_inset LatexCommand \index{\#pragma noloopreverse}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to signed int
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- - Will not do loop reversal optimization
-\layout Itemize
+\layout Standard
-nooverlay
-\begin_inset LatexCommand \index{\#pragma nooverlay}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2ulong.
+\family default
+\series default
+\shape default
+\size default
+\emph default
+\bar default
+\noun default
+c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- - the compiler will not overlay the parameters and local variables of a
- function.
-\layout Itemize
+\layout Standard
-stackauto
-\begin_inset LatexCommand \index{\#pragma stackauto}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to unsigned long
\end_inset
-
-- See option -
-\begin_inset ERT
-status Collapsed
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_fs2long.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- and section
-\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
+\layout Standard
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert floating point to signed long
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- Parameters and Local Variables.
-\layout Itemize
+\layout Standard
-opt_code_speed
-\begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_uchar2fs.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-- The compiler will optimize code generation towards fast code, possibly
- at the expense of code size.
-\layout Itemize
+\layout Standard
-opt_code_size
-\begin_inset LatexCommand \index{\#pragma opt\_code\_size}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert unsigned char to floating point
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-- The compiler will optimize code generation towards compact code, possibly
- at the expense of code speed.
-\layout Itemize
+\layout Standard
-opt_code_balanced
-\begin_inset LatexCommand \index{\#pragma opt\_code\_balanced}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_char2fs.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-- The compiler will attempt to generate code that is both compact and fast,
- as long as meeting one goal is not a detriment to the other (this is the
- default).
-
-\layout Itemize
+\layout Standard
-std_sdcc89
-\begin_inset LatexCommand \index{\#pragma std\_sdcc89}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert char to floating point number
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-- Generally follow the C89 standard, but allow SDCC features that conflict
- with the standard (default).
-\layout Itemize
+\layout Standard
-std_c89
-\begin_inset LatexCommand \index{\#pragma std\_c89}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_uint2fs.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-- Follow the C89 standard and disable SDCC features that conflict with the
- standard.
-\layout Itemize
+\layout Standard
-std_sdcc99
-\begin_inset LatexCommand \index{\#pragma std\_sdcc99}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert unsigned int to floating point
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-- Generally follow the C99 standard, but allow SDCC features that conflict
- with the standard (incomplete support).
-\layout Itemize
+\layout Standard
-std_c99
-\begin_inset LatexCommand \index{\#pragma std\_c99}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_int2fs.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-- Follow the C99 standard and disable SDCC features that conflict with the
- standard (incomplete support).
-\layout Itemize
+\layout Standard
-codeseg <name>
-\begin_inset LatexCommand \index{\#pragma codeseg}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert int to floating point numbers
\end_inset
-
-- Use this name (max.
- 8 characters) for the code segment.
- See option -
-\begin_inset ERT
-status Collapsed
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_ulong2fs.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--codeseg.
-\layout Itemize
+\layout Standard
-constseg <name>
-\begin_inset LatexCommand \index{\#pragma constseg}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert unsigned long to floating point number
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-- Use this name (max.
- 8 characters) for the const segment.
- See option -
-\begin_inset ERT
-status Collapsed
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+_long2fs.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+convert long to floating point number
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
\end_inset
--constseg.
+
+\newline
+
\layout Standard
+\added_space_bottom bigskip
+These support routines are developed in ANSI-C so there is room for space
+ and speed improvement
+\begin_inset Foot
+collapsed false
-SDCPP supports the following #pragma directives:
-\layout Itemize
+\layout Standard
-preproc_asm
-\begin_inset LatexCommand \index{\#pragma preproc\_asm}
+These floating point routines (
+\emph on
+not
+\emph default
+ sinf(), cosf(), ...) for the mcs51 are implemented in assembler.
+
+\end_inset
+
+.
+ Note if all these routines are used simultaneously the data space might
+ overflow.
+ For serious floating point usage the large model might be needed.
+ Also notice that you don't have to call this routines directly.
+ The compiler will use them automatically every time a floating point operation
+ is required.
+\layout Section
+
+Library Routines
+\begin_inset LatexCommand \index{Libraries}
\end_inset
- (+ | -) - switch _asm _endasm block preprocessing on / off.
- Default is on.
+
+\layout Standard
+
+
+\emph on
+<pending: this is messy and incomplete - a little more information is in
+ sdcc/doc/libdoc.txt
+\emph default
+ >
+\layout Subsection
+
+Compiler support routines (_gptrget, _mulint etc.)
+\layout Subsection
+
+Stdclib functions (puts, printf, strcat etc.)
+\layout Subsubsection
+
+<stdio.h>
+\layout Paragraph
+
+getchar(), putchar()
\layout Standard
-The pragma's are intended to be used to turn-on or off certain optimizations
- which might cause the compiler to generate extra stack / data space to
- store compiler generated temporary variables.
- This usually happens in large functions.
- Pragma directives should be used as shown in the following example, they
- are used to control options & optimizations for a given function; pragmas
- should be placed before and/or after a function, placing pragma's inside
- a function body could have unpredictable results.
-\layout Verse
+\begin_inset LatexCommand \index{<stdio.h>}
+
+\end_inset
+As usual on embedded systems you have to provide your own
\family typewriter
-#pragma save
-\begin_inset LatexCommand \index{\#pragma save}
+getchar()
+\begin_inset LatexCommand \index{getchar()}
\end_inset
- \SpecialChar ~
+
+\family default
+and
+\family typewriter
+putchar()
+\begin_inset LatexCommand \index{putchar()}
+
+\end_inset
+
+
+\family default
+ routines.
+ SDCC does not know whether the system connects to a serial line with or
+ without handshake, LCD, keyboard or other device.
+ And whether a
+\family typewriter
+lf
+\family default
+ to
+\family typewriter
+crlf
+\family default
+ conversion within
+\family typewriter
+putchar()
+\family default
+ is intended.
+ You'll find examples for serial routines f.e.
+ in sdcc/device/lib.
+ For the mcs51 this minimalistic polling
+\family typewriter
+putchar()
+\family default
+ routine might be a start:
+\layout Verse
+
+
+\family typewriter
+void putchar (char c) {
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+while (!TI)\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* save the current settings */
+ /* assumes UART is initialized */
\newline
-#pragma nogcse
-\begin_inset LatexCommand \index{\#pragma nogcse}
-
-\end_inset
-
- \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* turnoff global subexpression elimination */
-\newline
-#pragma noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
-
-\end_inset
-
- /* turn off induction optimizations */
-\newline
-int foo ()
-\newline
-{
-\newline
\SpecialChar ~
- \SpecialChar ~
- ...
-
-\newline
\SpecialChar ~
- \SpecialChar ~
- /* large code */
+\SpecialChar ~
+\SpecialChar ~
+;
\newline
\SpecialChar ~
- \SpecialChar ~
- ...
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+TI = 0;
\newline
-}
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SBUF = c;
\newline
-#pragma restore
-\begin_inset LatexCommand \index{\#pragma restore}
+}
+\layout Paragraph
+
+printf()
+\layout Standard
+
+The default
+\family typewriter
+ printf()
+\begin_inset LatexCommand \index{printf()}
\end_inset
- /* turn the optimizations back on */
-\layout Standard
-The compiler will generate a warning message when extra space is allocated.
- It is strongly recommended that the save and restore pragma's be used when
- changing options for a function.
-\layout Section
+\family default
+ implementation in
+\family typewriter
+ printf_large.c
+\family default
+ does not support float (except on ds390).
+ To enable this recompile it with the option
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-Defines Created by the Compiler
\layout Standard
-The compiler creates the following #defines
-\begin_inset LatexCommand \index{\#defines}
-
+\backslash
+/
\end_inset
-
-\begin_inset LatexCommand \index{Defines created by the compiler}
+DUSE_FLOATS=1
+\begin_inset LatexCommand \index{USE\_FLOATS}
\end_inset
-:
-\newline
+
+\emph default
+ on the command line.
+ Use
+\emph on
+ -
+\begin_inset ERT
+status Collapsed
\layout Standard
+\backslash
+/
+\end_inset
+
+-model-large
+\begin_inset LatexCommand \index{-\/-model-large}
+
+\end_inset
-\begin_inset Tabular
-<lyxtabular version="3" rows="11" columns="2">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\emph default
+ for the mcs51 port, since this uses a lot of memory.
\layout Standard
+If you're short on code memory you might want to use
+\family typewriter
+printf_small()
+\begin_inset LatexCommand \index{printf\_small()}
-\series bold
-#define
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+
+
+\family default
+
+\emph on
+instead
+\emph default
+ of
+\family typewriter
+ printf().
+
+\family default
+ For the mcs51 there additionally are assembly versions
+\family typewriter
+printf_tiny()
+\begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
+
+\end_inset
+
+
+\family default
+ (subset of printf using less than 270 bytes) and
+\family typewriter
+printf_fast()
+\begin_inset LatexCommand \index{printf\_fast() (mcs51)}
+
+\end_inset
+
+
+\family default
+and
+\family typewriter
+ printf_fast_f()
+\begin_inset LatexCommand \index{printf\_fast\_f() (mcs51)}
+
+\end_inset
+
+
+\family default
+ (floating-point aware version of printf_fast) which should fit the requirements
+ of many embedded systems (printf_fast() can be customized by unsetting
+ #defines to
+\emph on
+not
+\emph default
+ support long variables and field widths).
+ Be sure to use only one of these printf options within a project.
+\newline
+
+\layout Standard
+
+Feature matrix of different
+\emph on
+printf
+\emph default
+ options on mcs51.
+\layout Standard
+
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="14" columns="7">
+<features islongtable="true">
+<column alignment="left" valignment="center" leftline="true" width="14col%">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="12col%">
+<column alignment="center" valignment="top" leftline="true" width="10col%">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="12col%">
+<column alignment="center" valignment="top" rightline="true" width="0">
+<row topline="true" bottomline="true" endhead="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
\series bold
-Description
+\size large
+mcs51
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC
-\begin_inset LatexCommand \index{SDCC}
+printf
+\begin_inset LatexCommand \index{printf}
\end_inset
-
+
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Always defined.
- Since version 2.5.6 the version number as an int (ex.
- 256)
+printf
+\size scriptsize
+USE_FLOATS=1
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_mcs51
-\begin_inset LatexCommand \index{SDCC\_mcs51}
-
+printf_small
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- or SDCC_ds390
-\begin_inset LatexCommand \index{SDCC\_ds390}
+\layout Standard
+printf_fast
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- or SDCC_z80
-\begin_inset LatexCommand \index{SDCC\_z80}
-
-\end_inset
+\layout Standard
-, etc
+printf_fast_f
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-depending on the model used (e.g.: -mds390
+printf_tiny
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" endhead="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-__mcs51
-\begin_inset LatexCommand \index{\_\_mcs51}
-
+filename
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-, __ds390
-\begin_inset LatexCommand \index{\_\_ds390}
-
-\end_inset
+\layout Standard
-, __hc08
-\begin_inset LatexCommand \index{\_\_hc08}
+\size scriptsize
+printf_large.c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-, __z80
-\begin_inset LatexCommand \index{\_\_z80}
+\layout Standard
-\end_inset
-, etc
+\size scriptsize
+printf_large.c
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-depending on the model used (e.g.
- -mz80)
+
+\size scriptsize
+printfl.c
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_STACK_AUTO
-\begin_inset LatexCommand \index{SDCC\_STACK\_AUTO}
-
-\end_inset
-
+\size scriptsize
+printf_fast.c
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-when
-\emph on
--
-\begin_inset ERT
-status Collapsed
+
+\size scriptsize
+printf_fast_f.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
--stack-auto
-\emph default
- option is used
+\size scriptsize
+printf_tiny.c
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" endhead="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_MODEL_SMALL
-\begin_inset LatexCommand \index{SDCC\_MODEL\_SMALL}
+\begin_inset Quotes sld
+\end_inset
+
+Hello World
+\begin_inset Quotes srd
\end_inset
+ size
+\layout Standard
+small / large
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-when
-\emph on
--
-\begin_inset ERT
-status Collapsed
+1.7k / 2.4k
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--model-small
-\emph default
- is used
+4.3k / 5.6k
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_MODEL_MEDIUM
-\begin_inset LatexCommand \index{SDCC\_MODEL\_MEDIUM}
-
+1.2k / 1.8k
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+1.3k / 1.3k
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-when
-\emph on
--
-\begin_inset ERT
-status Collapsed
+1.9k / 1.9k
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--model-medium
-\emph default
- is used
+0.44k / 0.44k
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" endhead="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_MODEL_LARGE
-\begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
+code size
+\layout Standard
+small / large
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+1.4k / 2.0k
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-when
-\emph on
--
-\begin_inset ERT
-status Collapsed
+2.8k / 3.7k
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--model-large
-\emph default
- is used
+0.45k / 0.47k (+ _ltoa)
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_USE_XSTACK
-\begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
-
+1.2k / 1.2k
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+1.6k / 1.6k
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-when
-\emph on
--
-\begin_inset ERT
-status Collapsed
+0.26k / 0.26k
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+formats
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--xstack
+\layout Standard
+
+cdi
+\emph on
+o
\emph default
- option is used
+psux
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_STACK_TENBIT
-\begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
-
-\end_inset
-
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+cd
+\family default
+\series default
+\shape default
+\size default
+\emph default
+\bar default
+\noun default
+f
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+i
+\family default
+\series default
+\shape default
+\size default
+\emph on
+\bar default
+\noun default
+o
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+psux
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-when
+c
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+d
+\family default
+\series default
+\shape default
+\size default
\emph on
--mds390
+\bar default
+\noun default
+o
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+s
+\family default
+\series default
+\shape default
+\size default
\emph default
- is used
+\bar default
+\noun default
+x
\end_inset
</cell>
-</row>
-<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC_MODEL_FLAT24
-\begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
-
+cdsux
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+cdfsux
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-when
-\emph on
--mds390
-\emph default
- is used
+cdsux
\end_inset
</cell>
</row>
-</lyxtabular>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\end_inset
+\layout Standard
+long (32 bit) support
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\layout Chapter
+\layout Standard
-Notes on supported Processors
-\layout Section
+x
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-MCS51 variants
-\begin_inset LatexCommand \label{sub:MCS51-variants}
+\layout Standard
+x
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{MCS51 variants}
-
+x
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-MCS51 processors are available from many vendors and come in many different
- flavours.
- While they might differ considerably in respect to Special Function Registers
- the core MCS51 is usually not modified or is kept compatible.
-
-\layout Subsection
+x
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-pdata access by SFR
\layout Standard
-With the upcome of devices with internal xdata and flash memory devices
- using port P2
-\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+x
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- as dedicated I/O port is becoming more popular.
- Switching the high byte for pdata
-\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+\layout Standard
+-
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- access which was formerly done by port P2 is then achieved by a Special
- Function Register
-\begin_inset LatexCommand \index{sfr}
+\layout Standard
+byte arguments on stack
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
- In well-established MCS51 tradition the address of this
-\emph on
-sfr
-\emph default
- is where the chip designers decided to put it.
- Needless to say that they didn't agree on a common name either.
- So that the startup code can correctly initialize xdata variables, you
- should define an sfr with the name _XPAGE
-\family typewriter
-
-\begin_inset LatexCommand \index{\_XPAGE (mcs51)}
+\layout Standard
+b
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\family default
- at the appropriate location if the default, port P2, is not used for this.
- Some examples are:
-\layout Verse
-
+b
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-sfr at 0x92 _XPAGE; /* Cypress EZ-USB family */
-\layout Verse
+\layout Standard
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-sfr at 0xaf _XPAGE; /* some Silicon Labs (Cygnal) chips */
-\layout Verse
+\layout Standard
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-sfr at 0xaa _XPAGE; /* some Silicon Labs (Cygnal) chips */
\layout Standard
-For more exotic implementations further customizations may be needed.
- See section
-\begin_inset LatexCommand \ref{sub:Startup-Code}
-
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- for other possibilities.
-\layout Subsection
-
-Other Features available by SFR
\layout Standard
-Some MCS51 variants offer features like Double DPTR
-\begin_inset LatexCommand \index{DPTR}
-
+-
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-, multiple DPTR, decrementing DPTR, 16x16 Multiply.
- These are currently not used for the MCS51 port.
- If you absolutely need them you can fall back to inline assembly or submit
- a patch to SDCC.
-\layout Section
-
-DS400 port
\layout Standard
-The DS80C400 microcontroller has a rich set of peripherals.
- In its built-in ROM library it includes functions to access some of the
- features, among them is a TCP stack with IP4 and IP6 support.
- Library headers (currently in beta status) and other files are provided
- at
-\size footnotesize
-
-\begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
+float format
+\begin_inset LatexCommand \index{Floating point support}
\end_inset
-.
-
-\layout Section
-The Z80 and gbz80 port
-\layout Standard
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-SDCC can target both the Zilog
-\begin_inset LatexCommand \index{Z80}
+\layout Standard
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- and the Nintendo Gameboy's Z80-like gbz80
-\begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
+\layout Standard
+%f
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
- The Z80 port is passed through the same
-\emph on
-regressions tests
-\begin_inset LatexCommand \index{Regression test}
+\layout Standard
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\emph default
- as the MCS51 and DS390 ports, so floating point support, support for long
- variables and bitfield support is fine.
- See mailing lists and forums about interrupt routines.
\layout Standard
-As always, the code is the authoritative reference - see z80/ralloc.c and
- z80/gen.c.
- The stack
-\begin_inset LatexCommand \index{stack}
+%f
+\begin_inset Foot
+collapsed true
+
+\layout Standard
+Range limited to +/- 4294967040, precision limited to 8 digits past decimal
\end_inset
- frame is similar to that generated by the IAR Z80 compiler.
- IX is used as the base pointer, HL and IY are used as a temporary registers,
- and BC and DE are available for holding variables.
- Return values
-\begin_inset LatexCommand \index{return value}
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- for the Z80 port are stored in L (one byte), HL (two bytes), or DEHL (four
- bytes).
- The gbz80 port use the same set of registers for the return values, but
- in a different order of significance: E (one byte), DE (two bytes), or
- HLDE (four bytes).
-\layout Section
-
-The HC08 port
\layout Standard
-The port to the Motorola HC08
-\begin_inset LatexCommand \index{HC08}
-
+-
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- family has been added in October 2003, and is still undergoing some basic
- development.
- The code generator is complete, but the register allocation is still quite
- unoptimized.
- Some of the SDCC's standard C library functions have embedded non-HC08
- inline assembly and so are not yet usable.
-\newline
-
-\newline
+\layout Standard
-\layout Section
+float formats %e %g
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-The PIC14 port
\layout Standard
-The 14bit PIC
-\begin_inset LatexCommand \index{PIC14}
-
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- port still requires a major effort from the development community.
- However it can work for very simple code.
-\layout Subsection
+\layout Standard
-C code and 14bit PIC code page
-\begin_inset LatexCommand \index{code page (pic14)}
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- and RAM banks
-\begin_inset LatexCommand \index{RAM bank (pic14)}
+\layout Standard
+-
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The linker organizes allocation for the code page and RAM banks.
- It does not have intimate knowledge of the code flow.
- It will put all the code section of a single asm file into a single code
- page.
- In order to make use of multiple code pages, separate asm files must be
- used.
- The compiler treats all functions of a single C file as being in the same
- code page unless it is non static.
- The compiler treats all local variables of a single C file as being in
- the same RAM bank unless it is an extern.
-\newline
+-
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-To get the best follow these guide lines:
-\layout Enumerate
+\layout Standard
-make local functions static, as non static functions require code page selection
- overhead.
-\layout Enumerate
+field width
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Make local variables static as extern variables require RAM bank selection
- overhead.
-\layout Enumerate
+\layout Standard
-For devices that have multiple code pages it is more efficient to use the
- same number of files as pages, i.e.
- for the 16F877 use 4 separate files and i.e.
- for the 16F874 use 2 separate files.
- This way the linker can put the code for each file into different code
- pages and the compiler can allocate reusable variables more efficiently
- and there's less page selection overhead.
- And as for any 8 bit micro (especially for PIC 14 as they have a very simple
- instruction set) use 'unsigned char' whereever possible instead of 'int'.
-\layout Subsection
+x
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Creating a device include file
\layout Standard
-For generating a device include file use the support perl script inc2h.pl
- kept in directory support/script.
-\layout Subsection
+x
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Interrupt code
\layout Standard
-For the interrupt function, use the keyword 'interrupt'
-\begin_inset LatexCommand \index{interrupt}
+-
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+x
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- with level number of 0 (PIC14 only has 1 interrupt so this number is only
- there to avoid a syntax error - it ought to be fixed).
- E.g.:
-\layout Verse
+\layout Standard
+x
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-void Intr(void) interrupt 0
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-T0IF = 0; /* Clear timer interrupt */
-\newline
-}
-\layout Subsection
+\layout Standard
+
+-
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Linking and assembling
\layout Standard
-For assembling you can use either GPUTILS'
-\begin_inset LatexCommand \index{gputils (pic tools)}
+string speed
+\begin_inset Foot
+collapsed true
+
+\layout Standard
+Execution time of printf("%s%c%s%c%c%c", "Hello", ' ', "World", '!', '
+\backslash
+r', '
+\backslash
+n'); standard 8051 @ 22.1184 MHz, empty putchar()
\end_inset
- gpasm.exe or MPLAB's mpasmwin.exe.
- GPUTILS is available from
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
+,
+\layout Standard
+small / large
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
- For linking you can use either GPUTIL's gplink or MPLAB's mplink.exe.
- If you use MPLAB and an interrupt function then the linker script file
- vectors section will need to be enlarged to link with mplink.
-\newline
+\layout Standard
-\newline
-Here is a
-\family typewriter
-Makefile
-\family default
- using GPUTILS:
-\layout Verse
-
-
-\family typewriter
-.c.o:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcc -S -V -mpic14 -p16F877 $<
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-gpasm -c $*.asm
-\newline
-
-\newline
-$(PRJ).hex: $(OBJS)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
-\layout Standard
-
-Here is a
-\family typewriter
-Makefile
-\family default
- using MPLAB:
-\layout Verse
-
-
-\family typewriter
-.c.o:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcc -S -V -mpic14 -p16F877 $<
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mpasmwin /q /o $*.asm
-\newline
-
-\newline
-$(PRJ).hex: $(OBJS)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib
-\layout Standard
-
-Please note that indentations within a
-\family typewriter
- Makefile
-\family default
- have to be done with a tabulator character.
-\layout Subsection
-
-Command-line options
-\layout Standard
-
-Besides the switches common to all SDCC backends, the PIC14 port accepts
- the following options (for an updated list see sdcc -
-\begin_inset ERT
-status Collapsed
+1.52 / 2.59 ms
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+1.53 / 2.62 ms
\end_inset
-
--help):
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+0.92 / 0.93 ms
\end_inset
-
--debug-extra emit debug info in assembly output
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+0.45 / 0.45 ms
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--no-pcode-opt disable (slightly faulty) optimization on pCode
-\layout Subsection
-
-The library
-\layout Subsubsection
-
-error: missing definition for symbol
-\begin_inset Quotes sld
-\end_inset
+\layout Standard
-__gptrget1
-\begin_inset Quotes srd
+0.46 / 0.46 ms
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The PIC14 port uses library routines to provide more complex operations
- like multiplication, division/modulus and (generic) pointer dereferencing.
- In order to add these routines to your project, you must link with PIC14's
-
-\family typewriter
-libsdcc.lib
-\family default
-.
- For single source file projects this is done automatically, more complex
- projects must add
-\family typewriter
-libsdcc.lib
-\family default
- to the linker's arguments.
- Make sure you also add an include path for the library (using the -I switch
- to the linker)!
-\layout Subsubsection
-
-Processor mismatch in file
-\begin_inset Quotes sld
-\end_inset
-
-XXX
-\begin_inset Quotes srd
+0.45 / 0.45 ms
\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
-\layout Standard
-
-This warning can usually be ignored due to the very good compatibility amongst
- 14 bit PIC devices.
\layout Standard
-You might also consider recompiling the library for your specific device
- by changing the ARCH=p16f877 (default target) entry in
-\family typewriter
-device/lib/pic/Makefile.in
-\family default
- and
-\family typewriter
-device/lib/pic/Makefile
-\family default
- to reflect your device.
- This might even improve performance for smaller devices as unneccesary
- BANKSELs migth be removed.
-\layout Subsection
-
-Known bugs
-\layout Subsubsection
+int speed
+\begin_inset Foot
+collapsed true
-initialized data
\layout Standard
-Currently, data can only be initialized if it resides in the source file
- together with
-\emph on
-main()
-\emph default
-.
- Data in other source files will silently
-\series bold
-not
-\series default
- be initialized.
-\layout Section
-
-The PIC16
-\begin_inset LatexCommand \index{PIC16}
-
+Execution time of printf("%d", -12345); standard 8051 @ 22.1184 MHz, empty
+ putchar()
\end_inset
- port
+,
\layout Standard
-The PIC16
-\begin_inset LatexCommand \index{PIC16}
-
+small / large
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- port is the portion of SDCC that is responsible to produce code for the
- Microchip
-\begin_inset LatexCommand \index{Microchip}
+\layout Standard
+3.01 / 3.61 ms
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-(TM) microcontrollers with 16 bit core.
- Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
- Currently supported devices are:
\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="4" columns="6">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true">
+3.01 / 3.61 ms
+\end_inset
+</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F242
+3.51 / 18.13 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-18F248
+0.22 / 0.22 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-18F252
+0.23 / 0.23 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-18F258
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+0.25 / 0.25 ms
+\begin_inset Foot
+collapsed true
\layout Standard
-18F442
+printf_tiny integer speed is data dependent, worst case is 0.33 ms
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-18F448
\end_inset
</cell>
</row>
-<row topline="true">
+<row bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F452
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+long speed
+\begin_inset Foot
+collapsed true
\layout Standard
-18F458
+Execution time of printf("%ld", -123456789); standard 8051 @ 22.1184 MHz,
+ empty putchar()
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+,
\layout Standard
-18F1220
+small / large
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F2220
+5.37 / 6.31 ms
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F2550
+5.37 / 6.31 ms
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F4331
+8.71 / 40.65 ms
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F4455
+0.40 / 0.40 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-18F6520
+0.40 / 0.40 ms
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F6620
+-
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F6680
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+float speed
+\begin_inset Foot
+collapsed true
\layout Standard
-18F6720
+Execution time of printf("%.3f", -12345.678); standard 8051 @ 22.1184 MHz,
+ empty putchar()
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+,
\layout Standard
-18F8520
+small / large
\end_inset
</cell>
-</row>
-<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-18F8620
+-
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-18F8680
+7.49 / 22.47 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-18F8720
+-
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
+-
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
+1.04 / 1.04 ms
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
+-
\end_inset
</cell>
</row>
\end_inset
-\layout Subsection
-
-Global Options
-\layout Standard
-
-PIC16 port supports the standard command line arguments as supposed, with
- the exception of certain cases that will be mentioned in the following
- list:
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+\layout Subsubsection
-\layout Standard
+<malloc.h>
+\begin_inset LatexCommand \index{malloc.h}
-\backslash
-/
\end_inset
--callee-saves See -
-\begin_inset ERT
-status Collapsed
\layout Standard
-\backslash
-/
-\end_inset
-
--all-callee-saves
-\layout List
-\labelwidthstring 00.00.0000
+As of SDCC 2.6.2 you no longer need to call an initialization routine before
+ using dynamic memory allocation
+\begin_inset LatexCommand \index{dynamic memory allocation (malloc)}
--
-\begin_inset ERT
-status Collapsed
+\end_inset
-\layout Standard
+ and a default heap
+\begin_inset LatexCommand \index{heap (malloc)}
-\backslash
-/
\end_inset
--all-callee-saves All function arguments are passed on stack by default.
-
-\emph on
-There is no need to specify this in the command line.
-\layout List
-\labelwidthstring 00.00.0000
+ space of 1024 bytes is provided for malloc to allocate memory from.
+ If you need a different heap size you need to recompile _heap.c with the
+ required size defined in HEAP_SIZE.
+ It is recommended to make a copy of this file into your project directory
+ and compile it there with:
+\layout Verse
--
-\begin_inset ERT
-status Collapsed
+\family typewriter
+sdcc -c _heap.c -D HEAD_SIZE=2048
\layout Standard
-\backslash
-/
-\end_inset
-
--fommit-frame-pointer Frame pointer will be omitted when the function uses
- no local variables.
-\layout Subsection
-
-Port Specific Options
-\begin_inset LatexCommand \index{Options PIC16}
-
-\end_inset
+And then link it with:
+\layout Verse
-\layout Standard
+\family typewriter
+sdcc main.rel _heap.rel
+\layout Subsection
-The port specific options appear after the global options in the sdcc --help
- output.
+Math functions (sinf, powf, sqrtf etc.)
\layout Subsubsection
-General Options
+<math.h>
\layout Standard
-General options enable certain port features and optimizations.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+See definitions in file <math.h>.
+\layout Subsection
+Other libraries
\layout Standard
-\backslash
-/
+Libraries
+\begin_inset LatexCommand \index{Libraries}
+
\end_inset
--stack-model=[model] Used in conjuction with the command above.
- Defines the stack model to be used, valid stack models are :
-\begin_deeper
-\layout List
-\labelwidthstring 00.00.0000
+ included in SDCC should have a license at least as liberal as the GNU Lesser
+ General Public License
+\begin_inset LatexCommand \index{GNU Lesser General Public License, LGPL}
+\end_inset
+
\emph on
-small
+LGPL
\emph default
- Selects small stack model.
- 8 bit stack and frame pointers.
- Supports 256 bytes stack size.
-\layout List
-\labelwidthstring 00.00.0000
+.
+\layout Standard
-\emph on
-large
-\emph default
- Selects large stack model.
- 16 bit stack and frame pointers.
- Supports 65536 bytes stack size.
-\end_deeper
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset Note
+collapsed true
--
-\begin_inset ERT
-status Collapsed
+\layout Standard
+license statements for the libraries are missing.
+ sdcc/device/lib/ser_ir.c
\layout Standard
-\backslash
-/
+or _decdptr f.e.
+ come with a GPL (as opposed to LGPL) License - this will not be liberal
+ enough for many embedded programmers.
\end_inset
--preplace-udata-with=[kword] Replaces the default udata keyword for allocating
- unitialized data variables with [kword].
- Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
\layout Standard
-\backslash
-/
+If you have ported some library or want to share experience about some code
+ which f.e.
+ falls into any of these categories Busses (I
+\begin_inset Formula $^{\textrm{2}}$
\end_inset
--ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
- Useful for bootloaders.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
+C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory
+ cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel,
+ Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
+\begin_inset LatexCommand \url{http://sourceforge.net/mail/?group_id=599}
-\backslash
-/
\end_inset
--asm= sets the full path and name of an external assembler to call.
-\layout List
-\labelwidthstring 00.00.0000
+\SpecialChar ~
+would certainly like to hear about it.
+\layout Standard
+\added_space_bottom bigskip
+Programmers coding for embedded systems are not especially famous for being
+ enthusiastic, so don't expect a big hurray but as the mailing list is searchabl
+e these references are very valuable.
+ Let's help to create a climate where information is shared.
+\layout Section
--
-\begin_inset ERT
-status Collapsed
+Memory Models
+\layout Subsection
-\layout Standard
+MCS51 Memory Models
+\begin_inset LatexCommand \index{Memory model}
-\backslash
-/
\end_inset
--link= sets the full path and name of an external linker to call.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-\layout Standard
+\begin_inset LatexCommand \index{MCS51 memory model}
-\backslash
-/
\end_inset
--mplab-comp MPLAB compatibility option.
- Currently only suppresses special gpasm directives.
+
\layout Subsubsection
-Optimization Options
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
+Small, Medium and Large
\layout Standard
-\backslash
-/
-\end_inset
+SDCC allows three memory models for MCS51 code,
+\shape slanted
+small, medium
+\shape default
+ and
+\shape slanted
+large
+\shape default
+.
+ Modules compiled with different memory models should
+\emph on
+never
+\emph default
+ be combined together or the results would be unpredictable.
+ The library routines supplied with the compiler are compiled as small,
+ medium and large.
+ The compiled library modules are contained in separate directories as small,
+ medium and large so that you can link to the appropriate set.
+\layout Standard
--optimize-goto Try to use (conditional) BRA instead of GOTO
-\layout List
-\labelwidthstring 00.00.0000
+When the medium or large model is used all variables declared without a
+ storage class will be allocated into the external ram, this includes all
+ parameters and local variables (for non-reentrant
+\begin_inset LatexCommand \index{reentrant}
--
-\begin_inset ERT
-status Collapsed
+\end_inset
+ functions).
+ When the small model is used variables without storage class are allocated
+ in the internal ram.
\layout Standard
-\backslash
-/
-\end_inset
+Judicious usage of the processor specific storage classes
+\begin_inset LatexCommand \index{Storage class}
--optimize-cmp Try to optimize some compares.
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
--
-\begin_inset ERT
-status Collapsed
+ and the 'reentrant' function type will yield much more efficient code,
+ than using the large model.
+ Several optimizations are disabled when the program is compiled using the
+ large model, it is therefore recommended that the small model be used unless
+ absolutely required.
+\layout Subsubsection
-\layout Standard
+External Stack
+\begin_inset LatexCommand \label{sub:External-Stack}
-\backslash
-/
\end_inset
--optimize-df Analyze the dataflow of the generated code and improve it.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-\layout Standard
+\begin_inset LatexCommand \index{stack}
-\backslash
-/
\end_inset
--obanksel=nn Set optimization level for inserting BANKSELs.
-\newline
-
-\begin_deeper
-\layout List
-\labelwidthstring 00.00.0000
-
-0 no optimization
-\layout List
-\labelwidthstring 00.00.0000
-1 checks previous used register and if it is the same then does not emit
- BANKSEL, accounts only for labels.
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset LatexCommand \index{External stack (mcs51)}
-2 tries to check the location of (even different) symbols and removes BANKSELs
- if they are in the same bank.
-
-\newline
+\end_inset
-\emph on
-Important: There might be problems if the linker script has data sections
- across bank borders!
-\end_deeper
-\layout Subsubsection
-Linking Options
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
+The external stack (-
\begin_inset ERT
status Collapsed
/
\end_inset
--nodefaultlibs do not link default libraries when linking
-\layout List
-\labelwidthstring 00.00.0000
+-xstack option
+\begin_inset LatexCommand \index{-\/-xstack}
--
-\begin_inset ERT
-status Collapsed
+\end_inset
-\layout Standard
+) is located in pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
-\backslash
-/
\end_inset
--no-crt Don't link the default run-time modules
-\layout List
-\labelwidthstring 00.00.0000
-
--
+ memory (usually at the start of the external ram segment) and uses all
+ unused space in pdata (max.
+ 256 bytes).
+ When -
\begin_inset ERT
status Collapsed
/
\end_inset
--use-crt= Use a custom run-time module instead of the defaults.
-\layout Subsubsection
-
-Debugging Options
-\layout Standard
+-xstack option is used to compile the program, the parameters and local
+ variables
+\begin_inset LatexCommand \index{local variables}
-Debugging options enable extra debugging information in the output files.
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
--
+ of all reentrant functions are allocated in this area.
+ This option is provided for programs with large stack space requirements.
+ When used with the -
\begin_inset ERT
status Collapsed
/
\end_inset
--debug-xtra Similar to -
-\begin_inset ERT
-status Collapsed
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+ option, all parameters and local variables are allocated on the external
+ stack (note: support libraries will need to be recompiled with the same
+ options.
+ There is a predefined target in the library makefile).
\layout Standard
-\backslash
-/
+The compiler outputs the higher order address byte of the external ram segment
+ into port P2
+\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
+
\end_inset
--debug
-\begin_inset LatexCommand \index{-\/-debug}
+ (see also section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
\end_inset
-, but dumps more information.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+), therefore when using the External Stack option, this port
+\emph on
+may not
+\emph default
+ be used by the application program.
+\layout Subsection
-\layout Standard
+DS390 Memory Model
+\begin_inset LatexCommand \index{Memory model}
-\backslash
-/
\end_inset
--debug-ralloc Force register allocator to dump <source>.d file with debugging
- information.
- <source> is the name of the file compiled.
-\layout List
-\labelwidthstring 00.00.0000
--
-\begin_inset ERT
-status Collapsed
+\begin_inset LatexCommand \index{DS390 memory model}
+
+\end_inset
+
\layout Standard
-\backslash
-/
+The only model supported is Flat 24
+\begin_inset LatexCommand \index{Flat 24 (DS390 memory model)}
+
\end_inset
--pcode-verbose Enable pcode debugging information in translation.
-\layout List
-\labelwidthstring 00.00.0000
+.
+ This generates code for the 24 bit contiguous addressing mode of the Dallas
+ DS80C390 part.
+ In this mode, up to four meg of external RAM or code space can be directly
+ addressed.
+ See the data sheets at www.dalsemi.com for further information on this part.
+\newline
--
-\begin_inset ERT
-status Collapsed
+\newline
+Note that the compiler does not generate any code to place the processor
+ into 24 bitmode (although
+\emph on
+tinibios
+\emph default
+ in the ds390 libraries will do that for you).
+ If you don't use
+\emph on
+tinibios
+\emph default
-\layout Standard
+\begin_inset LatexCommand \index{Tinibios (DS390)}
-\backslash
-/
\end_inset
--denable-peeps Force the usage of peepholes.
- Use with care.
-\layout List
-\labelwidthstring 00.00.0000
+, the boot loader or similar code must ensure that the processor is in 24
+ bit contiguous addressing mode before calling the SDCC startup code.
+\newline
+\newline
+Like the
+\emph on
-
\begin_inset ERT
status Collapsed
/
\end_inset
--gstack Trace push/pops for stack pointer overflow
-\layout List
-\labelwidthstring 00.00.0000
+-model-large
+\emph default
+ option, variables will by default be placed into the XDATA segment.
+
+\newline
--
+\newline
+Segments may be placed anywhere in the 4 meg address space using the usual
+ -
\begin_inset ERT
status Collapsed
/
\end_inset
--call-tree dump call tree in .calltree file
-\layout Subsection
+-*-loc options.
+ Note that if any segments are located above 64K, the -r flag must be passed
+ to the linker to generate the proper segment relocations, and the Intel
+ HEX output format must be used.
+ The -r flag can be passed to the linker by using the option
+\emph on
+-Wl-r
+\emph default
+ on the SDCC command line.
+ However, currently the linker can not handle code segments > 64k.
+\layout Section
-Enviromental Variables
-\layout Standard
+Pragmas
+\begin_inset LatexCommand \label{sec:Pragmas}
-There is a number of enviromental variables that can be used when running
- SDCC to enable certain optimizations or force a specific program behaviour.
- these variables are primarily for debugging purposes so they can be enabled/dis
-abled at will.
-\layout Standard
+\end_inset
-Currently there is only two such variables available:
-\layout List
-\labelwidthstring 00.00.0000
-OPTIMIZE_BITFIELD_POINTER_GET when this variable exists reading of structure
- bitfields is optimized by directly loading FSR0 with the address of the
- bitfield structure.
- Normally SDCC will cast the bitfield structure to a bitfield pointer and
- then load FSR0.
- This step saves data ram and code space for functions that perform heavy
- use of bitfields.
- (ie.
- 80 bytes of code space are saved when compiling malloc.c with this option).
-
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset LatexCommand \index{Pragmas}
-NO_REG_OPT do not perform pCode registers optimization.
- This should be used for debugging purposes.
- In some where bugs in the pcode optimizer are found, users can benefit
- from temporarily disabling the optimizer until the bug is fixed.
-\layout Subsection
+\end_inset
-Preprocessor Macros
-\layout Standard
-PIC16 port defines the following preprocessor macros while translating a
- source.
\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="6" columns="2">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+SDCC supports the following #pragma directives:
+\layout Itemize
-\layout Standard
-Macro
+\series bold
+save
+\series default
+
+\begin_inset LatexCommand \index{\#pragma save}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - this will save most current options to the save/restore stack.
+ See #pragma\SpecialChar ~
+restore.
+\layout Itemize
+
+
+\series bold
+restore
+\series default
+
+\begin_inset LatexCommand \index{\#pragma restore}
-Description
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - will restore saved options from the last save.
+ saves & restores can be nested.
+ SDCC uses a save/restore stack: save pushes current options to the stack,
+ restore pulls current options from the stack.
+ See #pragma\SpecialChar ~
+save.
+\newline
+
+\layout Itemize
+
+
+\series bold
+callee_saves
+\series default
+
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
-SDCC_pic16
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-Port identification
+\begin_inset LatexCommand \index{function prologue}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ function1[,function2[,function3...]] - The compiler by default uses a caller
+ saves convention for register saving across function calls, however this
+ can cause unnecessary register pushing & popping
+\begin_inset LatexCommand \index{push/pop}
-_
+\end_inset
+
+ when calling small functions from larger functions.
+ This option can be used to switch off the register saving convention for
+ the function names specified.
+ The compiler will not save registers when calling these functions, extra
+ code need to be manually inserted at the entry & exit for these functions
+ to save & restore the registers used by these functions, this can SUBSTANTIALLY
+ reduce code & improve run time performance of the generated code.
+ In the future the compiler (with inter procedural analysis) may be able
+ to determine the appropriate scheme to use for each function call.
+ If -
\begin_inset ERT
status Collapsed
/
\end_inset
-_pic16
+-callee-saves command line option is used, the function names specified
+ in #pragma\SpecialChar ~
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ is appended to the list of functions specified in the command line.
+\layout Itemize
+
+
+\series bold
+exclude
+\series default
+
+\begin_inset LatexCommand \index{\#pragma exclude}
-Port identification (same as above)
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables the generation
+ of pairs of push/pop
+\begin_inset LatexCommand \index{push/pop}
-pic18fxxxx
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ instructions in
+\emph on
+I
+\emph default
+nterrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
-MCU Identification.
\emph on
-xxxx
+S
\emph default
- is the microcontrol identification number, i.e.
- 452, 6620, etc
+ervice
+\emph on
+R
+\emph default
+outines.
+ The directive should be placed immediately before the ISR function definition
+ and it affects ALL ISR functions following it.
+ To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
+exclude\SpecialChar ~
+none
+\begin_inset LatexCommand \index{\#pragma exclude}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ See also the related keyword _naked
+\begin_inset LatexCommand \index{\_naked}
-_
-\begin_inset ERT
-status Collapsed
+\end_inset
-\layout Standard
-\backslash
-/
-\end_inset
+\begin_inset LatexCommand \index{\_\_naked}
-_18Fxxxx
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Itemize
-MCU Identification (same as above)
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+less_pedantic
+\series default
+
+\begin_inset LatexCommand \index{\#pragma less\_pedantic}
-STACK_MODEL_nnn
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - the compiler will not warn you anymore for obvious mistakes, you'r on
+ your own now ;-(
+\layout Itemize
-nnn = SMALL or LARGE respectively according to the stack model used
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+
+\series bold
+disable_warning
+\series default
+ <nnnn>
+\begin_inset LatexCommand \index{\#pragma disable\_warning}
\end_inset
+ - the compiler will not warn you anymore about warning number <nnnn>.
+\layout Itemize
-\layout Standard
-In addition the following macros are defined when calling assembler:
-\layout Standard
-\align center
+\series bold
+nogcse
+\series default
-\begin_inset Tabular
-<lyxtabular version="3" rows="4" columns="2">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+\begin_inset LatexCommand \index{\#pragma nogcse}
-Macro
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - will stop global common subexpression elimination.
+\layout Itemize
-Description
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+noinduction
+\series default
+
+\begin_inset LatexCommand \index{\#pragma noinduction}
-__18Fxxxx
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - will stop loop induction optimizations.
+\layout Itemize
-MCU Identification.
-
-\emph on
-xxxx
-\emph default
- is the microcontrol identification number, i.e.
- 452, 6620, etc
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+noinvariant
+\series default
+
+\begin_inset LatexCommand \index{\#pragma noinvariant}
-SDCC_MODEL_nnn
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - will not do loop invariant optimizations.
+ For more details see Loop Invariants in section
+\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
-nnn = SMALL or LARGE respectively according to the memory model used for
- SDCC
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Itemize
-STACK_MODEL_nnn
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+noiv
+\series default
-nnn = SMALL or LARGE respectively according to the stack model used
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+\begin_inset LatexCommand \index{\#pragma noiv}
\end_inset
+ - Do not generate interrupt
+\begin_inset LatexCommand \index{interrupt}
-\layout Subsection
+\end_inset
-Directories
-\layout Standard
+ vector table
+\begin_inset LatexCommand \index{interrupt vector table}
-PIC16
-\begin_inset LatexCommand \index{PIC16}
+\end_inset
+
+ entries for all ISR functions defined after the pragma.
+ This is useful in cases where the interrupt vector table must be defined
+ manually, or when there is a secondary, manually defined interrupt vector
+ table (e.g.
+ for the autovector feature of the Cypress EZ-USB FX2).
+ More elegantly this can be achieved by obmitting the optional interrupt
+ number after the interrupt keyword, see section
+\begin_inset LatexCommand \ref{sub:Interrupt-Service-Routines}
\end_inset
- port uses the following directories for searching header files and libraries.
-\layout Standard
-\align center
+\SpecialChar ~
+about interrupts.
+\layout Itemize
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="4">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+nojtbound
+\series default
+
+\begin_inset LatexCommand \index{\#pragma nojtbound}
-Directory
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - will not generate code for boundary value checking, when switch statements
+ are turned into jump-tables (dangerous).
+ For more details see section
+\begin_inset LatexCommand \ref{sub:'switch'-Statements}
-Description
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Itemize
-Target
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+noloopreverse
+\series default
+
+\begin_inset LatexCommand \index{\#pragma noloopreverse}
-Command prefix
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - Will not do loop reversal optimization
+\layout Itemize
-PREFIX/sdcc/include/pic16
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+nooverlay
+\series default
+
+\begin_inset LatexCommand \index{\#pragma nooverlay}
-PIC16 specific headers
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ - the compiler will not overlay the parameters and local variables of a
+ function.
+\layout Itemize
-Compiler
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+stackauto
+\series default
+
+\begin_inset LatexCommand \index{\#pragma stackauto}
--I
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+- See option -
+\begin_inset ERT
+status Collapsed
\layout Standard
-PREFIX/sdcc/lib/pic16
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
-PIC16 specific libraries
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ and section
+\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
-Linker
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ Parameters and Local Variables.
+\layout Itemize
--L
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+
+\series bold
+opt_code_speed
+\series default
+
+\begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
\end_inset
+- The compiler will optimize code generation towards fast code, possibly
+ at the expense of code size.
+ Currently this has little effect.
+\layout Itemize
-\layout Subsection
-Pragmas
-\begin_inset LatexCommand \label{sub:PIC16_Pragmas}
+\series bold
+opt_code_size
+\series default
+
+\begin_inset LatexCommand \index{\#pragma opt\_code\_size}
\end_inset
+- The compiler will optimize code generation towards compact code, possibly
+ at the expense of code speed.
+ Currently this has little effect.
+\layout Itemize
-\layout Standard
-
-PIC16 port currently supports the following pragmas:
-\layout List
-\labelwidthstring 00.00.0000
-stack pragma stack forces the code generator to initialize the stack & frame
- pointers at a specific address.
- This is an adhoc solution for cases where no STACK directive is available
- in the linker script or gplink is not instructed to create a stack section.
-\newline
-The stack pragma should be used only once in a project.
- Multiple pragmas may result in indeterminate behaviour of the program.
-\begin_inset Foot
-collapsed false
-
-\layout Standard
+\series bold
+opt_code_balanced
+\series default
+
+\begin_inset LatexCommand \index{\#pragma opt\_code\_balanced}
-The old format (ie.
- #pragma stack 0x5ff) is deprecated and will cause the stack pointer to
- cross page boundaries (or even exceed the available data RAM) and crash
- the program.
- Make sure that stack does not cross page boundaries when using the SMALL
- stack model.
\end_inset
+- The compiler will attempt to generate code that is both compact and fast,
+ as long as meeting one goal is not a detriment to the other (this is the
+ default).
+
+\layout Itemize
-\newline
-The format is as follows:
-\layout LyX-Code
-#pragma stack bottom_address [stack_size]
-\layout Standard
+\series bold
+std_sdcc89
+\series default
+
+\begin_inset LatexCommand \index{\#pragma std\_sdcc89}
+\end_inset
-\emph on
-bottom_address
-\emph default
- is the lower bound of the stack section.
- The stack pointer initially will point at address (bottom_address+stack_size-1).
-\layout LyX-Code
+- Generally follow the C89 standard, but allow SDCC features that conflict
+ with the standard (default).
+\layout Itemize
-Example:
-\layout LyX-Code
-\layout LyX-Code
+\series bold
+std_c89
+\series default
+
+\begin_inset LatexCommand \index{\#pragma std\_c89}
-/* initializes stack of 100 bytes at RAM address 0x200 */
-\layout LyX-Code
+\end_inset
-#pragma stack 0x200 100
-\layout Standard
+- Follow the C89 standard and disable SDCC features that conflict with the
+ standard.
+\layout Itemize
-If the stack_size field is omitted then a stack is created with the default
- size of 64.
- This size might be enough for most programs, but its not enough for operations
- with deep function nesting or excessive stack usage.
-\layout List
-\labelwidthstring 00.00.0000
-wparam
-\emph on
-This pragma is deprecated.
- Its use will cause a warning message to be issued.
-\emph default
+\series bold
+std_sdcc99
+\series default
+
+\begin_inset LatexCommand \index{\#pragma std\_sdcc99}
-\newline
+\end_inset
-\layout List
-\labelwidthstring 00.00.0000
+- Generally follow the C99 standard, but allow SDCC features that conflict
+ with the standard (incomplete support).
+\layout Itemize
-code place a function symbol at static FLASH address
-\layout LyX-Code
-Example:
-\layout LyX-Code
+\series bold
+std_c99
+\series default
+
+\begin_inset LatexCommand \index{\#pragma std\_c99}
-\layout LyX-Code
+\end_inset
-/* place function test_func at 0x4000 */
-\layout LyX-Code
+- Follow the C99 standard and disable SDCC features that conflict with the
+ standard (incomplete support).
+\layout Itemize
-#pragma code test_func 0x4000
-\layout LyX-Code
-\layout List
-\labelwidthstring 00.00.0000
+\series bold
+codeseg
+\series default
+ <name>
+\begin_inset LatexCommand \index{\#pragma codeseg}
-library instructs the linker to use a library module.
-\newline
-Usage:
-\layout LyX-Code
+\end_inset
+
+- Use this name (max.
+ 8 characters) for the code segment.
+ See option -
+\begin_inset ERT
+status Collapsed
-#pragma library module_name
\layout Standard
+\backslash
+/
+\end_inset
-\emph on
-module_name
-\emph default
- can be any library or object file (including its path).
- Note that there are four reserved keywords which have special meaning.
- These are:
-\layout Standard
-\align center
+-codeseg.
+\layout Itemize
-\begin_inset Tabular
-<lyxtabular version="3" rows="6" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="block" valignment="top" leftline="true" width="20page%">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+constseg
+\series default
+ <name>
+\begin_inset LatexCommand \index{\#pragma constseg}
-Keyword
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+- Use this name (max.
+ 8 characters) for the const segment.
+ See option -
+\begin_inset ERT
+status Collapsed
\layout Standard
-Description
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-constseg.
\layout Standard
-Module to link
+The preprocessor SDCPP
+\begin_inset LatexCommand \index{sdcpp (preprocessor)}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ supports the following #pragma directives:
+\layout Itemize
\series bold
-ignore
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+pedantic_parse_number
+\series default
-\layout Standard
+\begin_inset LatexCommand \index{\#pragma pedantic\_parse\_number}
-ignore all library pragmas
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+ (+ | -) - Pedantic parse numbers so that situations like 0xfe-LO_B(3) are
+ parsed properly and the macro LO_B(3) gets expanded.
+ Default is off.
+ Below is an example on how to use this pragma.
\emph on
-(none)
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ Note: this functionality is not in conformance with standard!
+\layout Verse
-\layout Standard
+\family typewriter
+#pragma pedantic_parse_number +
+\begin_inset LatexCommand \index{\#pragma pedantic\_parse\_number}
-\series bold
-c
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-link the C library
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\newline
-\layout Standard
+\newline
+#define LO_B(x) ((x) & 0xff)
+\newline
+\newline
+unsigned char foo(void)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+unsigned char c=0xfe-LO_B(3);
+\newline
-\emph on
-libc18f
-\emph default
-.lib
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return c;
+\newline
+}
+\newline
-\layout Standard
+\layout Itemize
\series bold
-math
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+preproc_asm
+\series default
-\layout Standard
+\begin_inset LatexCommand \index{\#pragma preproc\_asm}
-link the Math libarary
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ (+ | -) - switch _asm _endasm block preprocessing on / off.
+ Default is on.
+ You use this prama to define multilines of assembly code.
+ This will prevent the preprocessor from changing the formating required
+ by assembly code.
+ Below is an example on how to use this pragma.
+\layout Verse
-\emph on
-libm18f
-\emph default
-.lib
+\family typewriter
+#pragma preproc_asm -
+\begin_inset LatexCommand \index{\#pragma preproc\_asm}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\newline
+#define MYDELAY _asm
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+nop ;my assembly comment...
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+nop
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+nop
+\newline
+_endasm
+\newline
+#pragma preproc_asm +
+\newline
-\series bold
-io
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
+void foo (void)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ MYDELAY;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ ...
+
+\newline
+}
+\newline
-\layout Standard
+\layout Itemize
-link the I/O library
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\series bold
+sdcc_hash
+\series default
+\begin_inset LatexCommand \index{\#pragma sdcc\_hash}
-\emph on
-libio18f*
-\emph default
-.lib
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ (+ | -) - Allow "naked" hash in macro definition, for example:
+\newline
+\family typewriter
+#define DIR_LO(x) #(x & 0xff)
+\family default
-\series bold
-debug
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
+Default is off.
+ Below is an example on how to use this pragma.
+\layout Verse
-\layout Standard
-link the debug library
+\family typewriter
+#pragma preproc_asm +
+\newline
+#pragma sdcc_hash +
+\begin_inset LatexCommand \index{\#pragma sdcc\_hash}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\newline
-\emph on
-libdebug
-\emph default
-.lib
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+\newline
+#define ROMCALL(x)
+\backslash
-\end_inset
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov R6_B3, #(x & 0xff)
+\backslash
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov R7_B3, #((x >> 8) & 0xff)
+\backslash
\newline
-* is the device number, i.e.
- 452 for PIC18F452 MCU.
-\layout Standard
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+lcall __romcall
+\newline
-This feature allows for linking with specific libraries withoug having to
- explicit name them in the command line.
- Note that the
-\noun on
-ignore
-\noun default
- keyword will reject all modules specified by the library pragma.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+...
+\newline
+_asm
+\newline
+ROMCALL(72)
+\newline
+_endasm;
+\newline
+...
+\newline
-udata pragma udata instructs the compiler to emit code so that linker will
- place a variable at a specific memory bank
-\layout LyX-Code
+\layout Standard
-Example:
-\layout LyX-Code
+The pragma's are intended to be used to turn-on or off certain optimizations
+ which might cause the compiler to generate extra stack / data space to
+ store compiler generated temporary variables.
+ This usually happens in large functions.
+ Pragma directives should be used as shown in the following example, they
+ are used to control options & optimizations for a given function; pragmas
+ should be placed before and/or after a function, placing pragma's inside
+ a function body could have unpredictable results.
+\layout Verse
-\layout LyX-Code
-/* places variable foo at bank2 */
-\layout LyX-Code
+\family typewriter
+#pragma save
+\begin_inset LatexCommand \index{\#pragma save}
-#pragma udata bank2 foo
-\layout LyX-Code
+\end_inset
-char foo;
-\layout Standard
+ \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* save the current settings */
+\newline
+#pragma nogcse
+\begin_inset LatexCommand \index{\#pragma nogcse}
-In order for this pragma to work extra SECTION directives should be added
- in the .lkr script.
- In the following example a sample .lkr file is shown:
-\layout LyX-Code
+\end_inset
-\layout LyX-Code
+ \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* turnoff global subexpression elimination */
+\newline
+#pragma noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
-// Sample linker script for the PIC18F452 processor
-\layout LyX-Code
+\end_inset
-LIBPATH .
-\layout LyX-Code
+ /* turn off induction optimizations */
+\newline
+int foo ()
+\newline
+{
+\newline
+\SpecialChar ~
+ \SpecialChar ~
+ ...
+
+\newline
+\SpecialChar ~
+ \SpecialChar ~
+ /* large code */
+\newline
+\SpecialChar ~
+ \SpecialChar ~
+ ...
+
+\newline
+}
+\newline
+#pragma restore
+\begin_inset LatexCommand \index{\#pragma restore}
-CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
-\layout LyX-Code
+\end_inset
-CODEPAGE NAME=page START=0x2A END=0x7FFF
-\layout LyX-Code
+ /* turn the optimizations back on */
+\layout Standard
-CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
-\layout LyX-Code
+The compiler will generate a warning message when extra space is allocated.
+ It is strongly recommended that the save and restore pragma's be used when
+ changing options for a function.
+\newline
-CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
-\layout LyX-Code
+\newline
-CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
-\layout LyX-Code
+\newline
-CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
-\layout LyX-Code
+\layout Section
-ACCESSBANK NAME=accessram START=0x0 END=0x7F
-\layout LyX-Code
+Defines Created by the Compiler
+\layout Standard
-\layout LyX-Code
+The compiler creates the following #defines
+\begin_inset LatexCommand \index{\#defines}
-DATABANK NAME=gpr0 START=0x80 END=0xFF
-\layout LyX-Code
+\end_inset
-DATABANK NAME=gpr1 START=0x100 END=0x1FF
-\layout LyX-Code
-DATABANK NAME=gpr2 START=0x200 END=0x2FF
-\layout LyX-Code
+\begin_inset LatexCommand \index{Defines created by the compiler}
-DATABANK NAME=gpr3 START=0x300 END=0x3FF
-\layout LyX-Code
+\end_inset
-DATABANK NAME=gpr4 START=0x400 END=0x4FF
-\layout LyX-Code
-
-DATABANK NAME=gpr5 START=0x500 END=0x5FF
-\layout LyX-Code
-
-ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
-\layout LyX-Code
-
-\layout LyX-Code
-
-SECTION NAME=CONFIG ROM=config
-\layout LyX-Code
-
-\layout LyX-Code
-
-SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
-\layout LyX-Code
-
-SECTION NAME=bank1 RAM=gpr1 # should be added to link
-\layout LyX-Code
+:
+\newline
-SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
-\layout LyX-Code
+\layout Standard
-SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
-\layout LyX-Code
-SECTION NAME=bank4 RAM=gpr4
-\layout LyX-Code
+\begin_inset Tabular
+<lyxtabular version="3" rows="11" columns="2">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="3in">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="3in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-SECTION NAME=bank5 RAM=gpr5
\layout Standard
-The linker will recognise the section name set in the pragma statement and
- will position the variable at the memory bank set with the RAM field at
- the SECTION line in the linker script file.
-\layout Subsection
-
-Header Files
-\begin_inset LatexCommand \label{sub:PIC16_Header-Files}
+\series bold
+#define
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-There is one main header file that can be included to the source files using
- the pic16 port.
- That file is the
+
\series bold
-pic18fregs.h
-\series default
-.
- This header file contains the definitions for the processor special registers,
- so it is necessary if the source accesses them.
- It can be included by adding the following line in the beginning of the
- file:
-\layout LyX-Code
+Description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-#include <pic18fregs.h>
\layout Standard
-The specific microcontroller is selected within the pic18fregs.h automatically,
- so the same source can be used with a variety of devices.
-\layout Subsection
-
-Libraries
-\layout Standard
+SDCC
+\begin_inset LatexCommand \index{SDCC}
-The libraries that PIC16
-\begin_inset LatexCommand \index{PIC16}
+\end_inset
+
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- port depends on are the microcontroller device libraries which contain
- the symbol definitions for the microcontroller special function registers.
- These libraries have the format pic18fxxxx.lib, where
-\emph on
-xxxx
-\emph default
- is the microcontroller identification number.
- The specific library is selected automatically by the compiler at link
- stage according to the selected device.
\layout Standard
-Libraries are created with gplib which is part of the gputils package
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
-
+Always defined.
+ Since version 2.5.6 the version number as an int (ex.
+ 256)
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
-\layout Subsubsection*
-
-Building the libraries
\layout Standard
-Before using SDCC/pic16 there are some libraries that need to be compiled.
- This process is not done automatically by SDCC since not all users use
- SDCC for pic16 projects.
- So each user should compile the libraries separately.
-\layout Standard
+SDCC_mcs51
+\begin_inset LatexCommand \index{SDCC\_mcs51}
-The steps to compile the pic16 libraries under Linux are:
-\layout LyX-Code
+\end_inset
-cd device/lib/pic16
-\layout LyX-Code
+ or SDCC_ds390
+\begin_inset LatexCommand \index{SDCC\_ds390}
-./configure
-\layout LyX-Code
+\end_inset
-make
-\layout LyX-Code
+ or SDCC_z80
+\begin_inset LatexCommand \index{SDCC\_z80}
-cd ..
-\layout LyX-Code
+\end_inset
-make model-pic16
-\layout LyX-Code
+, etc.
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-su -c 'make install' # install the libraries, you need the root password
\layout Standard
-If you need to install the headers too, do:
-\layout LyX-Code
-
-cd device/include
-\layout LyX-Code
+depending on the model used (e.g.: -mds390)
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-su -c 'make install' # install the headers, you need the root password
\layout Standard
-There exist a special target to build the I/O libraries.
- This target is not automatically build because it will build the I/O library
- for
-\emph on
-every
-\emph default
- supported device.
- This way building will take quite a lot of time.
- Users are advised to edit the
-\series bold
-device/lib/pic16/pics.build
-\series default
- file and then execute:
-\layout LyX-Code
-
-make lib-io
-\layout Subsection
-
-Memory Models
-\layout Standard
+__mcs51
+\begin_inset LatexCommand \index{\_\_mcs51}
-The following memory models are supported by the PIC16 port:
-\layout Itemize
+\end_inset
-small model
-\layout Itemize
+, __ds390
+\begin_inset LatexCommand \index{\_\_ds390}
-large model
-\layout Standard
+\end_inset
-Memory model affects the default size of pointers within the source.
- The sizes are shown in the next table:
-\layout Standard
-\align center
+, __hc08
+\begin_inset LatexCommand \index{\_\_hc08}
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\end_inset
-\layout Standard
+, __z80
+\begin_inset LatexCommand \index{\_\_z80}
-Pointer sizes according to memory model
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-small model
+, etc
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-large model
+depending on the model used (e.g.
+ -mz80)
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-code pointers
+SDCC_STACK_AUTO
+\begin_inset LatexCommand \index{SDCC\_STACK\_AUTO}
+
\end_inset
-</cell>
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-16-bits
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-24-bits
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\emph default
+ option is used
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-data pointers
+SDCC_MODEL_SMALL
+\begin_inset LatexCommand \index{SDCC\_MODEL\_SMALL}
+
\end_inset
-</cell>
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-16-bits
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-16-bits
-\end_inset
-</cell>
-</row>
-</lyxtabular>
-
-\end_inset
-
-
-\layout Standard
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-It is advisable that all sources within a project are compiled with the
- same memory model.
- If one wants to override the default memory model, this can be done by
- declaring a pointer as
-\series bold
-far
-\series default
- or
-\series bold
-near
-\series default
-.
- Far selects large memory model's pointers, while near selects small memory
- model's pointers.
\layout Standard
-The standard device libraries (see
-\begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
-
+\backslash
+/
\end_inset
-) contain no reference to pointers, so they can be used with both memory
- models.
-\layout Subsection
+-model-small
+\emph default
+ is used
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Stack
\layout Standard
-The stack implementation for the PIC16 port uses two indirect registers,
- FSR1 and FSR2.
-\layout List
-\labelwidthstring 00.00.0000
-
-FSR1 is assigned as stack pointer
-\layout List
-\labelwidthstring 00.00.0000
+SDCC_MODEL_MEDIUM
+\begin_inset LatexCommand \index{SDCC\_MODEL\_MEDIUM}
-FSR2 is assigned as frame pointer
-\layout Standard
+\end_inset
-The following stack models are supported by the PIC16 port
-\layout Itemize
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\noun on
-small
-\noun default
- model
-\layout Itemize
+\layout Standard
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
-\noun on
-large
-\noun default
- model
\layout Standard
+\backslash
+/
+\end_inset
-\noun on
-Small
-\noun default
- model means that only the FSRxL byte is used to access stack and frame,
- while
-\emph on
-\noun on
-large
+-model-medium
\emph default
-\noun default
- uses both FSRxL and FSRxH registers.
- The following table shows the stack/frame pointers sizes according to stack
- model and the maximum space they can address:
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
+ is used
+\end_inset
+</cell>
+</row>
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Stack & Frame pointer sizes according to stack model
+SDCC_MODEL_LARGE
+\begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-small
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-large
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-large
+\emph default
+ is used
\end_inset
</cell>
</row>
\layout Standard
-Stack pointer FSR1
+SDCC_USE_XSTACK
+\begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
+
+\end_inset
+
+
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-8-bits
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack
+\emph default
+ option is used
\end_inset
</cell>
+</row>
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-16-bits
+SDCC_STACK_TENBIT
+\begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
+
+\end_inset
+
+
\end_inset
</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-Frame pointer FSR2
+when
+\emph on
+-mds390
+\emph default
+ is used
\end_inset
</cell>
+</row>
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-8-bits
+SDCC_MODEL_FLAT24
+\begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
+
+\end_inset
+
+
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-16-bits
+when
+\emph on
+-mds390
+\emph default
+ is used
\end_inset
</cell>
</row>
\end_inset
-\layout Standard
+\layout Chapter
+
+Notes on supported Processors
+\layout Section
+MCS51 variants
+\begin_inset LatexCommand \label{sub:MCS51-variants}
-\noun on
-Large
-\noun default
-stack model is currently not working properly throughout the code generator.
- So its use is not advised.
- Also there are some other points that need special care:
-\newline
+\end_inset
-\layout Enumerate
-Do not create stack sections with size more than one physical bank (that
- is 256 bytes)
-\layout Enumerate
+\begin_inset LatexCommand \index{MCS51 variants}
+
+\end_inset
+
-Stack sections should no cross physical bank limits (i.e.
- #pragma stack 0x50 0x100)
\layout Standard
-These limitations are caused by the fact that only FSRxL is modified when
- using SMALL stack model, so no more than 256 bytes of stack can be used.
- This problem will disappear after LARGE model is fully implemented.
+MCS51 processors are available from many vendors and come in many different
+ flavours.
+ While they might differ considerably in respect to Special Function Registers
+ the core MCS51 is usually not modified or is kept compatible.
+
\layout Subsection
-Functions
+pdata access by SFR
\layout Standard
-In addition to the standard SDCC function keywords, PIC16 port makes available
- two more:
-\layout List
-\labelwidthstring 00.00.0000
-
-wparam Use the WREG to pass one byte of the first function argument.
- This improves speed but you may not use this for functions with arguments
- that are called via function pointers, otherwise the first byte of the
- first parameter will get lost.
- Usage:
-\layout LyX-Code
+With the upcome of devices with internal xdata and flash memory devices
+ using port P2
+\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
-void func_wparam(int a) wparam
-\layout LyX-Code
+\end_inset
-{
-\layout LyX-Code
+ as dedicated I/O port is becoming more popular.
+ Switching the high byte for pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
- /* WREG hold the lower part of a */
-\layout LyX-Code
+\end_inset
- /* the high part of a is stored in FSR2+2 (or +3 for large stack model)
- */
-\layout LyX-Code
+ access which was formerly done by port P2 is then achieved by a Special
+ Function Register
+\begin_inset LatexCommand \index{sfr}
-...
-\layout LyX-Code
+\end_inset
-}
-\layout Standard
-
-This keyword replaces the deprecated wparam pragma.
-\layout List
-\labelwidthstring 00.00.0000
-
-shadowregs When entering/exiting an ISR, it is possible to take advantage
- of the PIC18F hardware shadow registers which hold the values of WREG,
- STATUS and BSR registers.
- This can be done by adding the keyword
-\emph on
-shadowregs
-\emph default
- before the
+.
+ In well-established MCS51 tradition the address of this
\emph on
-interrupt
+sfr
\emph default
- keyword in the function's header.
-\layout LyX-Code
+ is where the chip designers decided to put it.
+ Needless to say that they didn't agree on a common name either.
+ So that the startup code can correctly initialize xdata variables, you
+ should define an sfr with the name _XPAGE
+\family typewriter
-void isr_shadow(void) shadowregs interrupt 1
-\layout LyX-Code
+\begin_inset LatexCommand \index{\_XPAGE (mcs51)}
-{
-\layout LyX-Code
+\end_inset
-...
-\layout LyX-Code
-}
-\layout Standard
+\family default
+ at the appropriate location if the default, port P2, is not used for this.
+ Some examples are:
+\layout Verse
-\emph on
-shadowregs
-\emph default
- instructs the code generator not to store/restore WREG, STATUS, BSR when
- entering/exiting the ISR.
-\layout Subsection
+\family typewriter
+__sfr __at (0x85) _XPAGE; /* Ramtron VRS51 family a.k.a.
+ MPAGE */
+\layout Verse
-Function return values
-\layout Standard
-Return values from functions are placed to the appropriate registers following
- a modified Microchip policy optimized for SDCC.
- The following table shows these registers:
-\layout Standard
-\align center
+\family typewriter
+__sfr __at (0x92) _XPAGE; /* Cypress EZ-USB family, Texas Instruments (Chipcon)
+ a.k.a.
+ MPAGE */
+\layout Verse
-\begin_inset Tabular
-<lyxtabular version="3" rows="6" columns="2">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\family typewriter
+__sfr __at (0x91) _XPAGE; /* Infineon (Siemens) C500 family a.k.a.
+ XPAGE */
+\layout Verse
-size
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\family typewriter
+__sfr __at (0xaf) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a.
+ EMI0CN */
+\layout Verse
-destination register
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+__sfr __at (0xaa) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a.
+ EMI0CN */
\layout Standard
-8 bits
+For more exotic implementations further customizations may be needed.
+ See section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ for other possibilities.
+\layout Subsection
+
+Other Features available by SFR
\layout Standard
+\added_space_bottom bigskip
+Some MCS51 variants offer features like Double DPTR
+\begin_inset LatexCommand \index{DPTR}
-WREG
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+, multiple DPTR, decrementing DPTR, 16x16 Multiply.
+ These are currently not used for the MCS51 port.
+ If you absolutely need them you can fall back to inline assembly or submit
+ a patch to SDCC.
+\layout Section
+
+DS400 port
\layout Standard
+\added_space_bottom bigskip
+The DS80C400
+\begin_inset LatexCommand \index{DS80C400}
-16 bits
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-PRODL:WREG
+\begin_inset LatexCommand \index{DS400}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ microcontroller has a rich set of peripherals.
+ In its built-in ROM library it includes functions to access some of the
+ features, among them is a TCP stack with IP4 and IP6 support.
+ Library headers (currently in beta status) and other files are provided
+ at
+\size footnotesize
+
+\begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
-24 bits
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
+
+\layout Section
+
+The Z80 and gbz80 port
\layout Standard
-PRODH:PRODL:WREG
+SDCC can target both the Zilog Z80
+\begin_inset LatexCommand \index{Z80}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ and the Nintendo Gameboy's Z80-like gbz80
+\begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
-32 bits
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ The Z80 port is passed through the same
+\emph on
+regressions tests
+\begin_inset LatexCommand \index{Regression test}
-FSR0L:PRODH:PRODL:WREG
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
->32 bits
+\emph default
+ (see section
+\begin_inset LatexCommand \ref{sec:Quality-control}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+) as the MCS51 and DS390 ports, so floating point support, support for long
+ variables and bitfield support is fine.
+ See mailing lists and forums about interrupt routines.
\layout Standard
+\added_space_bottom bigskip
+As always, the code is the authoritative reference - see z80/ralloc.c and
+ z80/gen.c.
+ The stack
+\begin_inset LatexCommand \index{Z80!stack}
-on stack, FSR0 points to the beginning
\end_inset
-</cell>
-</row>
-</lyxtabular>
-\end_inset
+ frame is similar to that generated by the IAR Z80 compiler.
+ IX is used as the base pointer, HL and IY are used as a temporary registers,
+ and BC and DE are available for holding variables.
+ Return values
+\begin_inset LatexCommand \index{Z80!return value}
+\end_inset
-\layout Subsection
+ for the Z80 port are stored in L (one byte), HL (two bytes), or DEHL (four
+ bytes).
+ The gbz80 port use the same set of registers for the return values, but
+ in a different order of significance: E (one byte), DE (two bytes), or
+ HLDE (four bytes).
+\layout Section
-Interrupts
+The HC08 port
\layout Standard
-An interrupt servive routine (ISR) is declared using the
-\emph on
-interrupt
-\emph default
- keyword.
-\layout LyX-Code
-
-void isr(void) interrupt
-\emph on
-n
-\layout LyX-Code
-
-{
-\layout LyX-Code
+The port to the Freescale/Motorola HC08
+\begin_inset LatexCommand \index{HC08}
-...
-\layout LyX-Code
+\end_inset
-}
+ family has been added in October 2003, and is still undergoing some basic
+ development.
+ The code generator is complete, but the register allocation is still quite
+ unoptimized.
+ Some of the SDCC's standard C library functions have embedded non-HC08
+ inline assembly and so are not yet usable.
\layout Standard
+\added_space_bottom bigskip \pagebreak_bottom
+The HC08 port passes the regression test suite (see section
+\begin_inset LatexCommand \ref{sec:Quality-control}
+\end_inset
-\emph on
-n
-\emph default
- is the interrupt number, which for PIC18F devices can be:
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="4" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+).
+\layout Section
+The PIC14 port
\layout Standard
+The 14bit PIC
+\begin_inset LatexCommand \index{PIC14}
-\emph on
-n
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ port still requires a major effort from the development community.
+ However it can work for simple code.
+ It passes its (smaller set of) regression tests
+\begin_inset LatexCommand \index{Regression test (PIC14)}
-Interrupt Vector
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-Interrupt Vector Address
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ in the directory
+\shape italic
+sdcc/src/regression
+\shape default
+.
+\layout Subsection
-\layout Standard
+C code and 14bit PIC code page
+\begin_inset LatexCommand \index{code page (pic14)}
-0
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ and RAM banks
+\begin_inset LatexCommand \index{RAM bank (pic14)}
-RESET vector
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-0x000000
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
\layout Standard
+The linker organizes allocation for the code page and RAM banks.
+ It does not have intimate knowledge of the code flow.
+ It will put all the code section of a single asm file into a single code
+ page.
+ In order to make use of multiple code pages, separate asm files must be
+ used.
+ The compiler treats all functions of a single C file as being in the same
+ code page unless it is non static.
+\newline
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-1
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
+To get the best follow these guide lines:
+\layout Enumerate
-\layout Standard
+Make local functions static, as non static functions require code page selection
+ overhead.
+\layout Enumerate
+For devices that have multiple code pages it is more efficient to use the
+ same number of files as pages, i.e.
+ for the 16F877 use 4 separate files and i.e.
+ for the 16F874 use 2 separate files.
+ This way the linker can put the code for each file into different code
+ pages and there's less page selection overhead.
+\layout Enumerate
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-HIGH priority interrupts
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+And as for any 8 bit micro (especially for PIC 14 as they have a very simple
+ instruction set), use 'unsigned char' whereever possible instead of 'int'.
+\layout Subsection
+Creating a device include file
\layout Standard
-0x000008
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+For generating a device include file
+\begin_inset LatexCommand \index{PIC14!Header files}
-2
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-LOW priority interrupts
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ use the support perl script inc2h.pl kept in directory support/script.
+\layout Subsection
+Interrupt code
\layout Standard
-0x000018
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+For the interrupt function, use the keyword '__interrupt'
+\begin_inset LatexCommand \index{PIC14!interrupt}
\end_inset
+ with level number of 0 (PIC14 only has 1 interrupt so this number is only
+ there to avoid a syntax error - it ought to be fixed).
+ E.g.:
+\layout Verse
-\layout Standard
-When generating assembly code for ISR the code generator places a
-\noun on
-goto
-\noun default
-instruction at the
-\emph on
-Interrupt Vector Address
-\emph default
- which points at the genetated ISR.
- This single GOTO instruction is part of an automatically generated
-\emph on
-interrupt entry point
-\emph default
- function.
- The actuall ISR code is placed as normally would in the code space.
- Upon interrupt request, the GOTO instruction is executed which jumps to
- the ISR code.
- When declaring interrupt functions as _naked this GOTO instruction is
-\series bold
-not
-\series default
- generated.
- The whole interrupt functions is therefore placed at the Interrupt Vector
- Address of the specific interrupt.
- This is not a problem for the LOW priority interrupts, but it is a problem
- for the RESET and the HIGH priority interrupts because code may be written
- at the next interrupt´s vector address and cause undeterminate program
- behaviour if that interrupt is raised.
-\begin_inset Foot
-collapsed false
+\family typewriter
+void Intr(void) __interrupt 0
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+T0IF = 0; /* Clear timer interrupt */
+\newline
+}
+\layout Subsection
+Linking and assembling
\layout Standard
-This is not a problem when
-\layout Enumerate
-
-this is a HIGH interrupt ISR and LOW interrupts are
-\emph on
-disabled
-\emph default
- or not used.
-\layout Enumerate
+For assembling you can use either GPUTILS'
+\begin_inset LatexCommand \index{gputils (pic tools)}
-when the ISR is small enough not to reach the next interrupt´s vector address.
\end_inset
-
-\layout Standard
-
-
-\emph on
-n
-\emph default
- is possible to be omitted.
- This way a function is generated similar to an ISR, but it is not assigned
- to any interrupt.
-\layout Standard
-
-When entering an interrupt, currently the PIC16
-\begin_inset LatexCommand \index{PIC16}
+ gpasm.exe or MPLAB's mpasmwin.exe.
+ GPUTILS is available from
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
\end_inset
- port automatically saves the following registers:
-\layout Itemize
-
-WREG
-\layout Itemize
+.
+ For linking you can use either GPUTIL's gplink or MPLAB's mplink.exe.
+ If you use MPLAB and an interrupt function then the linker script file
+ vectors section will need to be enlarged to link with mplink.
+\newline
-STATUS
-\layout Itemize
+\newline
+Here is a
+\family typewriter
+Makefile
+\family default
+ using GPUTILS:
+\layout Verse
-BSR
-\layout Itemize
-PROD (PRODL and PRODH)
-\layout Itemize
+\family typewriter
+.c.o:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcc -S -V -mpic14 -p16F877 $<
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+gpasm -c $*.asm
+\newline
-FSR0 (FSR0L and FSR0H)
+\newline
+$(PRJ).hex: $(OBJS)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
\layout Standard
-These registers are restored upon return from the interrupt routine.
-\begin_inset Foot
-collapsed false
+Here is a
+\family typewriter
+Makefile
+\family default
+ using MPLAB:
+\layout Verse
-\layout Standard
-NOTE that when the _naked attribute is specified for an interrupt routine,
- then NO registers are stored or restored.
-\end_inset
+\family typewriter
+.c.o:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcc -S -V -mpic14 -p16F877 $<
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mpasmwin /q /o $*.asm
+\newline
+\newline
+$(PRJ).hex: $(OBJS)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib
+\layout Standard
+Please note that indentations within a
+\family typewriter
+ Makefile
+\family default
+ have to be done with a tabulator character.
\layout Subsection
-Generic Pointers
-\layout Standard
-
-Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types.
- There are 3 types of generic pointers currently implemented data, code
- and eeprom pointers.
- They are differentiated by the value of the 7th and 6th bits of the upper
- byte:
+Command-line options
\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="5" columns="5">
-<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" width="0">
-<column alignment="left" valignment="top" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Besides the switches common to all SDCC backends, the PIC14 port accepts
+ the following options (for an updated list see sdcc -
+\begin_inset ERT
+status Collapsed
\layout Standard
-pointer type
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-help):
+\layout List
+\labelwidthstring 00.00.0000
-7th bit
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-6th bit
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-debug-extra
+\begin_inset LatexCommand \index{PIC14!Options!-\/-debug-extra}
-rest of the pointer
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ emit debug info in assembly output
+\layout List
+\labelwidthstring 00.00.0000
-descrption
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-data
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-no-pcode-opt
+\begin_inset LatexCommand \index{PIC14!Options!-\/-no-pcode-opt}
-1
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ disable (slightly faulty) optimization on pCode
+\layout List
+\labelwidthstring 00.00.0000
-0
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-
-\family typewriter
-\shape slanted
-\emph on
-uuuuuu uuuuxxxx xxxxxxxx
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-stack-loc
+\begin_inset LatexCommand \index{PIC14!Options!-\/-stack-loc}
-a 12-bit data pointer in data RAM memory
\end_inset
-</cell>
-</row>
-<row bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ sets the lowest address of the argument passing stack (defaults to a suitably
+ large shared databank to reduce BANKSEL overhead)
+\layout List
+\labelwidthstring 00.00.0000
-code
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-0
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-stack-size
+\begin_inset LatexCommand \index{PIC14!Options!-\/-stack-size}
-0
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ sets the size if the argument passing stack (default: 16, minimum: 4)
+\layout Subsection
+The library
+\layout Subsubsection
-\family typewriter
-\shape slanted
-\emph on
-uxxxxx xxxxxxxx xxxxxxxx
+error: missing definition for symbol
+\begin_inset Quotes sld
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-a 21-bit code pointer in FLASH memory
+__gptrget1
+\begin_inset Quotes srd
\end_inset
-</cell>
-</row>
-<row bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-eeprom
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
\layout Standard
-0
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+The PIC14 port uses library routines to provide more complex operations
+ like multiplication, division/modulus and (generic) pointer dereferencing.
+ In order to add these routines to your project, you must link with PIC14's
+
+\family typewriter
+libsdcc.lib
+\family default
+.
+ For single source file projects this is done automatically, more complex
+ projects must add
+\family typewriter
+libsdcc.lib
+\family default
+ to the linker's arguments.
+ Make sure you also add an include path for the library (using the -I switch
+ to the linker)!
+\layout Subsubsection
-1
+Processor mismatch in file
+\begin_inset Quotes sld
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-
-\family typewriter
-\shape slanted
-\emph on
-uuuuuu uuuuuuxx xxxxxxxx
+XXX
+\begin_inset Quotes srd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
-a 10-bit eeprom pointer in EEPROM memory
+This warning can usually be ignored due to the very good compatibility amongst
+ 14 bit PIC
+\begin_inset LatexCommand \index{PIC14}
+
\end_inset
-</cell>
-</row>
-<row bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ devices.
\layout Standard
-(unimplemented)
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-1
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+You might also consider recompiling the library for your specific device
+ by changing the ARCH=p16f877 (default target) entry in
+\family typewriter
+device/lib/pic/Makefile.in
+\family default
+ and
+\family typewriter
+device/lib/pic/Makefile
+\family default
+ to reflect your device.
+ This might even improve performance for smaller devices as unneccesary
+ BANKSELs migth be removed.
+\layout Subsection
-1
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+Known bugs
+\layout Subsubsection
+initialized data
\layout Standard
-
-
-\family typewriter
-\shape slanted
+\pagebreak_bottom
+Currently, data can only be initialized if it resides in the source file
+ together with
\emph on
-xxxxxx xxxxxxxx xxxxxxxx
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+main()
+\emph default
+.
+ Data in other source files will silently
+\series bold
+not
+\series default
+ be initialized.
+\family typewriter
+\size footnotesize
+
+\begin_inset Marginal
+collapsed true
\layout Standard
-unimplemented pointer type
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+\series bold
+\SpecialChar ~
+!
\end_inset
-\layout Standard
+\layout Section
-Generic pointer are read and written with a set of library functions which
- read/write 1, 2, 3, 4 bytes.
-\layout Subsection
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
-PIC16 C Libraries
-\layout Subsubsection
+\end_inset
-Standard I/O Streams
+ port
\layout Standard
-In the
-\emph on
-stdio.h
-\emph default
- the type FILE is defined as:
-\layout LyX-Code
-
-typedef char * FILE;
-\layout Standard
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
-This type is the stream type implemented I/O in the PIC18F devices.
- Also the standard input and output streams are declared in stdio.h:
-\layout LyX-Code
+\end_inset
-extern FILE * stdin;
-\layout LyX-Code
+ port is the portion of SDCC that is responsible to produce code for the
+ Microchip
+\begin_inset LatexCommand \index{Microchip}
-extern FILE * stdout;
-\layout Standard
+\end_inset
-The FILE type is actually a generic pointer which defines one more type
- of generic pointers, the
-\emph on
-stream
-\emph default
-pointer.
- This new type has the format:
+(TM) microcontrollers with 16 bit core.
+ Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
+ Currently supported devices are:
\layout Standard
\align center
\begin_inset Tabular
-<lyxtabular version="3" rows="2" columns="7">
+<lyxtabular version="3" rows="4" columns="6">
<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="center" valignment="top" width="0">
-<column alignment="left" valignment="top" rightline="true" width="0">
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-pointer type
+18F242
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-<7:6>
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-<5>
+18F248
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-<4>
+18F252
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-<3:0>
+18F258
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-rest of the pointer
+18F442
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-descrption
+18F448
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-stream
+18F452
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-00
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-1
+18F458
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-0
+18F1220
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-nnnn
+18F2220
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family typewriter
-\shape slanted
-\emph on
-uuuuuuuu uuuuuuuu
+18F2550
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-upper byte high nubble is 0x2n, the rest are zeroes
+18F4331
\end_inset
</cell>
</row>
-</lyxtabular>
-
-\end_inset
-
-
-\layout Standard
-
-Currently implemented there are 3 types of streams defined:
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="4" columns="4">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-stream type
+18F4455
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-value
+18F6520
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-module
+18F6620
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-description
+18F6680
\end_inset
</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-STREAM_USART
+18F6720
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-
-\family typewriter
-0x200000UL
+18F8520
\end_inset
</cell>
+</row>
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-USART
+18F8620
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Writes/Reads characters via the USART peripheral
+18F8680
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-STREAM_MSSP
+18F8720
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-
-\family typewriter
-0x210000UL
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-MSSP
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Writes/Reads characters via the MSSP peripheral
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+</lyxtabular>
-STREAM_USER
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-\family typewriter
-0x2f0000UL
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Subsection
+Global Options
\layout Standard
-(none)
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+PIC16 port supports the standard command line arguments as supposed, with
+ the exception of certain cases that will be mentioned in the following
+ list:
+\layout List
+\labelwidthstring 00.00.0000
-\layout Standard
+-
+\begin_inset ERT
+status Collapsed
-Writes/Reads characters via used defined functions
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+\layout Standard
+\backslash
+/
\end_inset
+-callee-saves
+\begin_inset LatexCommand \index{PIC16!Options!-\/-callee-saves}
-\layout Standard
-
-The stream identifiers are declared as macros in the stdio.h header.
-\layout Standard
-
-In the libc library there exist the functions that are used to write to
- each of the above streams.
- These are
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
-_
+ See -
\begin_inset ERT
status Collapsed
/
\end_inset
-_stream_usart_putchar writes a character at the USART stream
+-all-callee-saves
\layout List
\labelwidthstring 00.00.0000
-_
+-
\begin_inset ERT
status Collapsed
/
\end_inset
-_stream_mssp_putchar writes a character at the MSSP stream
-\layout List
-\labelwidthstring 00.00.0000
+-all-callee-saves
+\begin_inset LatexCommand \index{PIC16!Options!-\/-all-callee-saves}
-putchar dummy function.
- This writes a character to a user specified manner.
-\layout Standard
+\end_inset
-In order to increase performance
-\emph on
-putchar
-\emph default
-is declared in stdio.h as having its parameter in WREG (it has the wparam
- keyword).
- In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function
- in a user-friendly way.
+ All function arguments are passed on stack by default.
\emph on
-arg
-\emph default
- is the name of the variable that holds the character to print.
- An example follows:
-\layout LyX-Code
-
-#include <pic18fregs.h>
-\newline
-#include <stdio.h>
-\newline
+There is no need to specify this in the command line.
+\layout List
+\labelwidthstring 00.00.0000
-\newline
-PUTCHAR( c )
-\layout LyX-Code
+-
+\begin_inset ERT
+status Collapsed
-{
-\layout LyX-Code
+\layout Standard
- PORTA = c; /* dump character c to PORTA */
-\layout LyX-Code
+\backslash
+/
+\end_inset
-}
-\newline
+-fommit-frame-pointer
+\begin_inset LatexCommand \index{PIC16!Options!-\/-fommit-frame-pointer}
-\newline
-void main(void)
-\layout LyX-Code
+\end_inset
-{
-\layout LyX-Code
+ Frame pointer will be omitted when the function uses no local variables.
+\layout Subsection
- stdout = STREAM_USER; /* this is not necessery, since stdout points
-\layout LyX-Code
+Port Specific Options
+\begin_inset LatexCommand \index{Options PIC16}
- * by default to STREAM_USER */
-\layout LyX-Code
+\end_inset
- printf (¨This is a printf test
-\backslash
-n¨);
-\layout LyX-Code
-}
-\layout LyX-Code
+\layout Standard
+The port specific options appear after the global options in the sdcc --help
+ output.
\layout Subsubsection
-Printing functions
+General Options
\layout Standard
-PIC16 contains an implementation of the printf-family of functions.
- There exist the following functions:
-\layout LyX-Code
-
-extern unsigned int sprintf(char *buf, char *fmt, ...);
-\layout LyX-Code
-
-extern unsigned int vsprintf(char *buf, char *fmt, va_list ap);
-\layout LyX-Code
-
-\layout LyX-Code
+General options enable certain port features and optimizations.
+\layout List
+\labelwidthstring 00.00.0000
-extern unsigned int printf(char *fmt, ...);
-\layout LyX-Code
+-
+\begin_inset ERT
+status Collapsed
-extern unsigned int vprintf(char *fmt, va_lista ap);
-\layout LyX-Code
+\layout Standard
-\layout LyX-Code
+\backslash
+/
+\end_inset
-extern unsigned int fprintf(FILE *fp, char *fmt, ...);
-\layout LyX-Code
+-pstack-model=[model] Used in conjuction with the command above.
+ Defines the stack model to be used, valid stack models are :
+\begin_deeper
+\layout List
+\labelwidthstring 00.00.0000
-extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap);
-\layout Standard
-For sprintf and vsprintf
\emph on
-buf
+small
\emph default
-should normally be a data pointer where the resulting string will be placed.
- No range checking is done so the user should allocate the necessery buffer.
- For fprintf and vfprintf
+ Selects small stack model.
+ 8 bit stack and frame pointers.
+ Supports 256 bytes stack size.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\emph on
-fp
+large
\emph default
- should be a stream pointer (i.e.
- stdout, STREAM_MSSP, etc...).
-\layout Subsubsection
+ Selects large stack model.
+ 16 bit stack and frame pointers.
+ Supports 65536 bytes stack size.
+\end_deeper
+\layout List
+\labelwidthstring 00.00.0000
-Signals
-\layout Standard
+-
+\begin_inset ERT
+status Collapsed
-The PIC18F family of microcontrollers supports a number of interrupt sources.
- A list of these interrupts is shown in the following table:
\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="11" columns="4">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\backslash
+/
+\end_inset
-\layout Standard
+-preplace-udata-with=[kword] Replaces the default udata keyword for allocating
+ unitialized data variables with [kword].
+ Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
+\layout List
+\labelwidthstring 00.00.0000
-signal name
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-description
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
+ Useful for bootloaders.
+\layout List
+\labelwidthstring 00.00.0000
-signal name
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-descritpion
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-asm= sets the full path and name of an external assembler to call.
+\layout List
+\labelwidthstring 00.00.0000
-SIG_RB
-\end_inset
-</cell>
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-PORTB change interrupt
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-link= sets the full path and name of an external linker to call.
+\layout List
+\labelwidthstring 00.00.0000
-SIG_EE
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-EEPROM/FLASH write complete interrupt
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-mplab-comp MPLAB
+\begin_inset LatexCommand \index{PIC16!MPLAB}
-SIG_INT0
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-INT0 external interrupt
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ compatibility option.
+ Currently only suppresses special gpasm directives.
+\layout Subsubsection
-\layout Standard
+Optimization Options
+\layout List
+\labelwidthstring 00.00.0000
-SIG_BCOL
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Bus collision interrupt
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-optimize-goto Try to use (conditional) BRA instead of GOTO
+\layout List
+\labelwidthstring 00.00.0000
-SIG_INT1
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-INT1 external interrupt
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-optimize-cmp Try to optimize some compares.
+\layout List
+\labelwidthstring 00.00.0000
-SIG_LVD
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Low voltage detect interrupt
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-optimize-df Analyze the dataflow of the generated code and improve it.
+\layout List
+\labelwidthstring 00.00.0000
-SIG_INT2
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-INT2 external interrupt
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-obanksel=nn Set optimization level for inserting BANKSELs.
+\newline
-SIG_PSP
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\begin_deeper
+\layout List
+\labelwidthstring 00.00.0000
-\layout Standard
+0 no optimization
+\layout List
+\labelwidthstring 00.00.0000
-Parallel slave port interrupt
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+1 checks previous used register and if it is the same then does not emit
+ BANKSEL, accounts only for labels.
+\layout List
+\labelwidthstring 00.00.0000
-\layout Standard
+2 tries to check the location of (even different) symbols and removes BANKSELs
+ if they are in the same bank.
+
+\newline
-SIG_CCP1
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\emph on
+Important: There might be problems if the linker script has data sections
+ across bank borders!
+\end_deeper
+\layout Subsubsection
-\layout Standard
+Linking Options
+\layout List
+\labelwidthstring 00.00.0000
-CCP1 module interrupt
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-SIG_AD
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-nodefaultlibs do not link default libraries when linking
+\layout List
+\labelwidthstring 00.00.0000
-AD convertion complete interrupt
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-SIG_CCP2
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-no-crt Don't link the default run-time modules
+\layout List
+\labelwidthstring 00.00.0000
-CCP2 module interrupt
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-SIG_RC
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-use-crt= Use a custom run-time module instead of the defaults.
+\layout Subsubsection
+
+Debugging Options
\layout Standard
-USART receive interrupt
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Debugging options enable extra debugging information in the output files.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-SIG_TMR0
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+-debug-xtra Similar to -
+\begin_inset ERT
+status Collapsed
\layout Standard
-TMR0 overflow interrupt
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
-SIG_TX
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, but dumps more information.
+\layout List
+\labelwidthstring 00.00.0000
-USART transmit interrupt
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-SIG_TMR1
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-debug-ralloc Force register allocator to dump <source>.d file with debugging
+ information.
+ <source> is the name of the file compiled.
+\layout List
+\labelwidthstring 00.00.0000
-TMR1 overflow interrupt
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pcode-verbose Enable pcode debugging information in translation.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-denable-peeps Force the usage of peepholes.
+ Use with care.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-gstack Trace push/pops for stack pointer overflow
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-call-tree dump call tree in .calltree file
+\layout Subsection
+
+Enviromental Variables
+\layout Standard
+
+There is a number of enviromental variables that can be used when running
+ SDCC to enable certain optimizations or force a specific program behaviour.
+ these variables are primarily for debugging purposes so they can be enabled/dis
+abled at will.
+\layout Standard
+
+Currently there is only two such variables available:
+\layout List
+\labelwidthstring 00.00.0000
+
+OPTIMIZE_BITFIELD_POINTER_GET when this variable exists reading of structure
+ bitfields is optimized by directly loading FSR0 with the address of the
+ bitfield structure.
+ Normally SDCC will cast the bitfield structure to a bitfield pointer and
+ then load FSR0.
+ This step saves data ram and code space for functions that perform heavy
+ use of bitfields.
+ (ie.
+ 80 bytes of code space are saved when compiling malloc.c with this option).
+
+\layout List
+\labelwidthstring 00.00.0000
+
+NO_REG_OPT do not perform pCode registers optimization.
+ This should be used for debugging purposes.
+ In some where bugs in the pcode optimizer are found, users can benefit
+ from temporarily disabling the optimizer until the bug is fixed.
+\layout Subsection
+
+Preprocessor Macros
+\layout Standard
+
+PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port defines the following preprocessor macros while translating a source.
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Macro
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-SIG_MSSP
+Description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SDCC_pic16
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-SSP receive/transmit interrupt
+Port identification
\end_inset
</cell>
</row>
\layout Standard
-SIG_TMR2
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_pic16
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-TMR2 matches PR2 interrupt
+Port identification (same as above)
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
+pic18fxxxx
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
+MCU Identification.
+
+\emph on
+xxxx
+\emph default
+ is the microcontrol identification number, i.e.
+ 452, 6620, etc
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SIG_TMR3
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_18Fxxxx
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-TMR3 overflow interrupt
+MCU Identification (same as above)
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
+STACK_MODEL_nnn
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
+nnn = SMALL or LARGE respectively according to the stack model used
\end_inset
</cell>
</row>
\layout Standard
-The prototypes for these names are defined in the header file
-\emph on
-signal.h
-\emph default
- .
+In addition the following macros are defined when calling assembler:
\layout Standard
+\align center
-In order to simplify signal handling, a number of macros is provided:
-\layout List
-\labelwidthstring 00.00.0000
-
-DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
- high priority interrupts.
-
-\emph on
-name
-\emph default
- is the function name to use.
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
- low priority interrupt.
-
-\emph on
-name
-\emph default
- is the function name to use.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
-DEF_HANDLER(sig,handler) define a handler for signal
-\emph on
-sig.
-\layout List
-\labelwidthstring 00.00.0000
+Macro
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-END_DEF end the declaration of the dispatch table.
\layout Standard
-Additionally there are two more macros to simplify the declaration of the
- signal handler:
-\layout List
-\labelwidthstring 00.00.0000
+Description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series medium
-SIGHANDLER(handler)
-\series default
-this declares the function prototype for the
-\emph on
-handler
-\emph default
- function.
-\layout List
-\labelwidthstring 00.00.0000
+__18Fxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function.
\layout Standard
-An example of using the macros above is shown below:
-\layout LyX-Code
+MCU Identification.
+
+\emph on
+xxxx
+\emph default
+ is the microcontrol identification number, i.e.
+ 452, 6620, etc
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-#include <pic18fregs.h>
-\layout LyX-Code
+\layout Standard
-#include <signal.h>
-\newline
+SDCC_MODEL_nnn
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-DEF_INTHIGH(high_int)
-\layout LyX-Code
+\layout Standard
-DEF_HANDLER(SIG_TMR0, _tmr0_handler)
-\layout LyX-Code
+nnn = SMALL or LARGE respectively according to the memory model used for
+ SDCC
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-DEF_HANDLER(SIG_BCOL, _bcol_handler)
-\layout LyX-Code
+\layout Standard
-END_DEF
-\newline
+STACK_MODEL_nnn
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-SIGHANDLER(_tmr0_handler)
-\layout LyX-Code
+\layout Standard
-{
-\layout LyX-Code
+nnn = SMALL or LARGE respectively according to the stack model used
+\end_inset
+</cell>
+</row>
+</lyxtabular>
- /* action to be taken when timer 0 overflows */
-\layout LyX-Code
+\end_inset
-}
-\newline
-\newline
-SIGHANDLERNAKED(_bcol_handler)
-\layout LyX-Code
+\layout Subsection
-{
-\layout LyX-Code
+Directories
+\layout Standard
- _asm
-\layout LyX-Code
+PIC16
+\begin_inset LatexCommand \index{PIC16}
- /* action to be taken when bus collision occurs */
-\layout LyX-Code
+\end_inset
- retfie
-\layout LyX-Code
+ port uses the following directories for searching header files and libraries.
+\layout Standard
+\align center
- _endasm;
-\layout LyX-Code
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="4">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-}
\layout Standard
+Directory
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\series bold
-NOTES:
-\series default
- Special care should be taken when using the above scheme:
-\layout Itemize
-
-do not place a colon (;) at the end of the DEF_* and END_DEF macros.
-\layout Itemize
+\layout Standard
-when declaring SIGHANDLERNAKED handler never forget to use
-\emph on
-retfie
-\emph default
- for proper returning.
-\layout Subsection
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-PIC16 Port -- Tips
\layout Standard
-Here you can find some general tips for compiling programs with SDCC/pic16.
-\layout Subsubsection
+Target
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Stack size
\layout Standard
-The default stack size (that is 64 bytes) probably is enough for many programs.
- One must take care that when there are many levels of function nesting,
- or there is excessive usage of stack, its size should be extended.
- An example of such a case is the printf/sprintf family of functions.
- If you encounter problems like not being able to print integers, then you
- need to set the stack size around the maximum (256 for small stack model).
- The following diagram shows what happens when calling printf to print an
- integer:
-\layout LyX-Code
+Command prefix
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-printf () --> ltoa () --> ultoa () --> divschar ()
\layout Standard
-It is should be understood that stack is easily consumed when calling complicate
-d functions.
- Using command line arguments like -
-\begin_inset ERT
-status Collapsed
+PREFIX/sdcc/include/pic16
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+PIC16 specific headers
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--fommit-frame-pointer might reduce stack usage by not creating unnecessery
- stack frames.
- Other ways to reduce stack usage may exist.
-\layout Chapter
-
-Debugging
\layout Standard
-There are several approaches to debugging your code.
- This chapter is meant to show your options and to give detail on some of
- them:
-\newline
+Compiler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-When writing your code:
-\layout Itemize
+\layout Standard
-write your code with debugging in mind (avoid duplicating code, put conceptually
- similar variables into structs, use structured code, have strategic points
- within your code where all variables are consistent, ...)
-\layout Itemize
+-I
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-run a syntax-checking tool like splint
-\begin_inset LatexCommand \index{splint (syntax checking tool)}
+\layout Standard
+PREFIX/sdcc/lib/pic16
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{lint (syntax checking tool)}
-
+PIC16 specific libraries
\end_inset
-
- (see -
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+Linker
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--more-pedantic
-\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+\layout Standard
+-L
\end_inset
+</cell>
+</row>
+</lyxtabular>
-) over the code.
-\layout Itemize
-
-for the high level code use a C-compiler (like f.e.
- GCC) to compile run and debug the code on your host.
- See (see -
-\begin_inset ERT
-status Collapsed
+\end_inset
-\layout Standard
-\backslash
-/
-\end_inset
+\layout Subsection
--more-pedantic
-\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+Pragmas
+\begin_inset LatexCommand \label{sub:PIC16_Pragmas}
\end_inset
- ) on howto handle syntax extensions like __xdata, __at(), ...
-
-\layout Itemize
-use another C-compiler to compile code for your target.
- Always an option but not recommended:) And not very likely to help you.
- If you seriously consider walking this path you should at least occasionally
- check portability of your code.
- Most commercial compiler vendors will offer an evaluation version so you
- can test compile your code or snippets of your code.
\layout Standard
-Debugging on a simulator:
-\layout Itemize
-
-there is a separate section about SDCDB (section
-\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
+PIC16
+\begin_inset LatexCommand \index{PIC16}
\end_inset
-) below.
-\layout Itemize
+ port currently supports the following pragmas:
+\layout List
+\labelwidthstring 00.00.0000
-or (8051 specific) use a freeware/commercial simulator which interfaces
- to the AOMF
-\begin_inset LatexCommand \index{AOMF, AOMF51}
+stack
+\begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma stack}
\end_inset
- file (see
-\begin_inset LatexCommand \ref{OMF file}
+ pragma stack
+\begin_inset LatexCommand \index{PIC16!stack}
\end_inset
-) optionally generated by SDCC.
+ forces the code generator to initialize the stack & frame pointers at a
+ specific address.
+ This is an adhoc solution for cases where no STACK directive is available
+ in the linker script or gplink is not instructed to create a stack section.
+\newline
+The stack pragma should be used only once in a project.
+ Multiple pragmas may result in indeterminate behaviour of the program.
+\begin_inset Foot
+collapsed false
+
\layout Standard
-Debugging On-target:
-\layout Itemize
+The old format (ie.
+ #pragma stack 0x5ff) is deprecated and will cause the stack pointer to
+ cross page boundaries (or even exceed the available data RAM) and crash
+ the program.
+ Make sure that stack does not cross page boundaries when using the SMALL
+ stack model.
+\end_inset
-use a MCU port pin to serially output debug data to the RS232 port of your
- host.
- You'll probably want some level shifting device typically involving a MAX232
- or similar IC.
- If the hardware serial port of the MCU is not available search for 'Software
- UART' in your favourite search machine.
-\layout Itemize
-use an on-target monitor.
- In this context a monitor is a small program which usually accepts commands
- via a serial line and allows to set program counter, to single step through
- a program and read/write memory locations.
- For the 8051 good examples of monitors are paulmon and cmon51 (see section
-
-\begin_inset LatexCommand \ref{sec:Related-open-source-tools}
+\newline
+The format is as follows:
+\layout LyX-Code
-\end_inset
+#pragma stack bottom_address [stack_size]
+\layout Standard
-).
-\layout Itemize
-toggle MCU port pins at strategic points within your code and use an oscilloscop
-e.
- A
\emph on
-digital oscilloscope
+bottom_address
\emph default
+ is the lower bound of the stack section.
+ The stack pointer initially will point at address (bottom_address+stack_size-1).
+\layout LyX-Code
-\begin_inset LatexCommand \index{oscilloscope}
+Example:
+\layout LyX-Code
-\end_inset
+\layout LyX-Code
- with deep trace memory is really helpful especially if you have to debug
- a realtime application.
- If you need to monitor more pins than your oscilloscope provides you can
- sometimes get away with a small R-2R network.
- On a single channel oscilloscope you could f.e.
- monitor 2 push-pull driven pins by connecting one via a 10\SpecialChar ~
-k
-\begin_inset Formula $\Omega$
-\end_inset
+/* initializes stack of 100 bytes at RAM address 0x200 */
+\layout LyX-Code
- resistor and the other one by a 5\SpecialChar ~
-k
-\begin_inset Formula $\Omega$
-\end_inset
+#pragma stack 0x200 100
+\layout Standard
- resistor to the oscilloscope probe (check output drive capability of the
- pins you want to monitor).
- If you need to monitor many more pins a
-\emph on
-logic analyzer
-\emph default
- will be handy.
-\layout Itemize
+If the stack_size field is omitted then a stack is created with the default
+ size of 64.
+ This size might be enough for most programs, but its not enough for operations
+ with deep function nesting or excessive stack usage.
+\layout List
+\labelwidthstring 00.00.0000
-use an ICE (
-\emph on
-i
-\emph default
-n
-\emph on
-c
-\emph default
-ircuit
-\emph on
-e
-\emph default
-mulator
-\begin_inset LatexCommand \index{ICE (in circuit emulator)}
+code
+\begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma code}
\end_inset
-).
- Usually very expensive.
- And very nice to have too.
- And usually locks you (for years...) to the devices the ICE can emulate.
-
-\layout Itemize
+ place a function symbol at static FLASH address
+\layout LyX-Code
-use a remote debugger.
- In most 8-bit systems the symbol information is not available on the target,
- and a complete debugger is too bulky for the target system.
- Therefore usually a debugger on the host system connects to an on-target
- debugging stub which accepts only primitive commands.
-
-\newline
-Terms to enter into your favourite search engine could be 'remote debugging',
- 'gdb stub' or 'inferior debugger'.
- (is there one?)
-\layout Itemize
+Example:
+\layout LyX-Code
-use an on target hardware debugger.
- Some of the more modern MCUs include hardware support for setting break
- points and monitoring/changing variables by using dedicated hardware pins.
- This facility doesn't require additional code to run on the target and
-
-\emph on
-usually
-\emph default
- doesn't affect runtime behaviour until a breakpoint is hit.
- For the mcs51 most hardware debuggers use the AOMF
-\begin_inset LatexCommand \index{AOMF, AOMF51}
+\layout LyX-Code
-\end_inset
+/* place function test_func at 0x4000 */
+\layout LyX-Code
- file (see
-\begin_inset LatexCommand \ref{OMF file}
+#pragma code test_func 0x4000
+\layout LyX-Code
-\end_inset
+\layout List
+\labelwidthstring 00.00.0000
-) as input file.
-
+library instructs the linker to use a library module.
+\newline
+Usage:
+\layout LyX-Code
+
+#pragma library module_name
\layout Standard
-Last not least:
-\layout Itemize
-if you are not familiar with any of the following terms you're likely to
- run into problems rather sooner than later:
-\emph on
-volatile
-\emph default
-,
-\emph on
-atomic
-\emph default
-,
-\emph on
-memory map
-\emph default
-,
\emph on
-overlay
-\emph default
-.
- As an embedded programmer you
-\emph on
-have
-\emph default
- to know them so why not look them up
-\emph on
-before
+module_name
\emph default
- you have problems?)
-\layout Itemize
+ can be any library or object file (including its path).
+ Note that there are four reserved keywords which have special meaning.
+ These are:
+\layout Standard
+\align center
-tell someone else about your problem (actually this is a surprisingly effective
- means to hunt down the bug even if the listener is not familiar with your
- environment).
- As 'failure to communicate' is probably one of the job-induced deformations
- of an embedded programmer this is highly encouraged.
-\layout Section
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="block" valignment="top" leftline="true" width="20page%">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Debugging with SDCDB
-\begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
+\layout Standard
+Keyword
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\begin_inset LatexCommand \index{sdcdb (debugger)}
+\layout Standard
+Module to link
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-
\layout Standard
-SDCC is distributed with a source level debugger
-\begin_inset LatexCommand \index{Debugger}
+\series bold
+ignore
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
- The debugger uses a command line interface, the command repertoire of the
- debugger has been kept as close to gdb
-\begin_inset LatexCommand \index{gdb}
+\layout Standard
+ignore all library pragmas
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- (the GNU debugger) as possible.
- The configuration and build process is part of the standard compiler installati
-on, which also builds and installs the debugger in the target directory
- specified during configuration.
- The debugger allows you debug BOTH at the C source and at the ASM source
- level.
- Sdcdb is currently not available on Win32 platforms.
-\layout Subsection
-
-Compiling for Debugging
\layout Standard
-The -
-\begin_inset ERT
-status Collapsed
+
+\emph on
+(none)
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\series bold
+c
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--debug
-\begin_inset LatexCommand \index{-\/-debug}
+\layout Standard
+link the C library
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
- option must be specified for all files for which debug information is to
- be generated.
- The compiler generates a .adb file for each of these files.
- The linker creates the .cdb
-\begin_inset LatexCommand \index{<file>.cdb}
+\emph on
+libc18f
+\emph default
+.lib
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- file from the .adb
-\begin_inset LatexCommand \index{<file>.adb}
+\layout Standard
-\end_inset
- files and the address information.
- This .cdb is used by the debugger.
-\layout Subsection
+\series bold
+math
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-How the Debugger Works
\layout Standard
-When the -
-\begin_inset ERT
-status Collapsed
+link the Math libarary
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
--debug option is specified the compiler generates extra symbol information
- some of which are put into the assembler source and some are put into the
- .adb file.
- Then the linker creates the .cdb file from the individual .adb files with
- the address information for the symbols.
- The debugger reads the symbolic information generated by the compiler &
- the address information generated by the linker.
- It uses the SIMULATOR (Daniel's S51) to execute the program, the program
- execution is controlled by the debugger.
- When a command is issued for the debugger, it translates it into appropriate
- commands for the simulator.
- (Currently sdcdb only connects to the simulator but
\emph on
-newcdb
+libm18f
\emph default
- at
-\begin_inset LatexCommand \url{http://ec2drv.sf.net/}
-
+.lib
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- is an effort to connect directly to the hardware.)
-\layout Subsection
-
-Starting the Debugger SDCDB
\layout Standard
-The debugger can be started using the following command line.
- (Assume the file you are debugging has the file name foo).
-\newline
-
-\newline
-\family sans
\series bold
-sdcdb foo
-\newline
-
-\family default
-\series default
+io
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-The debugger will look for the following files.
-\layout Itemize
+\layout Standard
-foo.c - the source file.
-\layout Itemize
+link the I/O library
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-foo.cdb - the debugger symbol information file.
-\layout Itemize
+\layout Standard
-foo.ihx - the Intel hex format
-\begin_inset LatexCommand \index{Intel hex format}
+\emph on
+libio18f*
+\emph default
+.lib
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- object file.
-\layout Subsection
+\layout Standard
-SDCDB Command Line Options
-\layout Itemize
--
-\begin_inset ERT
-status Collapsed
+\series bold
+debug
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+link the debug library
\end_inset
-
--directory=<source file directory> this option can used to specify the directory
- search list.
- The debugger will look into the directory list specified for source, cdb
- & ihx files.
- The items in the directory list must be separated by ':', e.g.
- if the source files can be in the directories /home/src1 and /home/src2,
- the -
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\emph on
+libdebug
+\emph default
+.lib
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
\end_inset
--directory option should be -
-\begin_inset ERT
-status Collapsed
+\newline
+* is the device number, i.e.
+ 452 for PIC18F452 MCU.
\layout Standard
-\backslash
-/
-\end_inset
+This feature allows for linking with specific libraries withoug having to
+ explicit name them in the command line.
+ Note that the
+\noun on
+ignore
+\noun default
+ keyword will reject all modules specified by the library pragma.
+\layout List
+\labelwidthstring 00.00.0000
--directory=/home/src1:/home/src2.
- Note there can be no spaces in the option.
-
-\layout Itemize
+udata pragma udata instructs the compiler to emit code so that linker will
+ place a variable at a specific memory bank
+\layout LyX-Code
--cd <directory> - change to the <directory>.
-\layout Itemize
+Example:
+\layout LyX-Code
--fullname - used by GUI front ends.
-\layout Itemize
+\layout LyX-Code
--cpu <cpu-type> - this argument is passed to the simulator please see the
- simulator docs for details.
-\layout Itemize
+/* places variable foo at bank2 */
+\layout LyX-Code
--X <Clock frequency > this options is passed to the simulator please see
- the simulator docs for details.
-\layout Itemize
+#pragma udata bank2 foo
+\layout LyX-Code
--s <serial port file> passed to simulator see the simulator docs for details.
-\layout Itemize
+char foo;
+\layout Standard
--S <serial in,out> passed to simulator see the simulator docs for details.
-\layout Itemize
+In order for this pragma to work extra SECTION directives should be added
+ in the .lkr script.
+ In the following example a sample .lkr file is shown:
+\layout LyX-Code
--k <port number> passed to simulator see the simulator docs for details.
-\layout Subsection
+\layout LyX-Code
-SDCDB Debugger Commands
-\layout Standard
+// Sample linker script for the PIC18F452 processor
+\layout LyX-Code
-As mentioned earlier the command interface for the debugger has been deliberatel
-y kept as close the GNU debugger gdb, as possible.
- This will help the integration with existing graphical user interfaces
- (like ddd, xxgdb or xemacs) existing for the GNU debugger.
- If you use a graphical user interface for the debugger you can skip this
- section.
-\layout Subsubsection*
+LIBPATH .
+\layout LyX-Code
-break [line | file:line | function | file:function]
-\layout Standard
+CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
+\layout LyX-Code
-Set breakpoint at specified line or function:
-\newline
+CODEPAGE NAME=page START=0x2A END=0x7FFF
+\layout LyX-Code
-\newline
+CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
+\layout LyX-Code
-\family sans
-\series bold
-sdcdb>break 100
-\newline
-sdcdb>break foo.c:100
-\newline
-sdcdb>break funcfoo
-\newline
-sdcdb>break foo.c:funcfoo
-\layout Subsubsection*
+CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
+\layout LyX-Code
-clear [line | file:line | function | file:function ]
-\layout Standard
+CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
+\layout LyX-Code
-Clear breakpoint at specified line or function:
-\newline
+CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
+\layout LyX-Code
-\newline
+ACCESSBANK NAME=accessram START=0x0 END=0x7F
+\layout LyX-Code
-\family sans
-\series bold
-sdcdb>clear 100
-\newline
-sdcdb>clear foo.c:100
-\newline
-sdcdb>clear funcfoo
-\newline
-sdcdb>clear foo.c:funcfoo
-\layout Subsubsection*
+\layout LyX-Code
-continue
-\layout Standard
+DATABANK NAME=gpr0 START=0x80 END=0xFF
+\layout LyX-Code
-Continue program being debugged, after breakpoint.
-\layout Subsubsection*
+DATABANK NAME=gpr1 START=0x100 END=0x1FF
+\layout LyX-Code
-finish
-\layout Standard
+DATABANK NAME=gpr2 START=0x200 END=0x2FF
+\layout LyX-Code
-Execute till the end of the current function.
-\layout Subsubsection*
+DATABANK NAME=gpr3 START=0x300 END=0x3FF
+\layout LyX-Code
-delete [n]
-\layout Standard
+DATABANK NAME=gpr4 START=0x400 END=0x4FF
+\layout LyX-Code
-Delete breakpoint number 'n'.
- If used without any option clear ALL user defined break points.
-\layout Subsubsection*
+DATABANK NAME=gpr5 START=0x500 END=0x5FF
+\layout LyX-Code
-info [break | stack | frame | registers ]
-\layout Itemize
+ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
+\layout LyX-Code
-info break - list all breakpoints
-\layout Itemize
+\layout LyX-Code
-info stack - show the function call stack.
-\layout Itemize
+SECTION NAME=CONFIG ROM=config
+\layout LyX-Code
-info frame - show information about the current execution frame.
-\layout Itemize
+\layout LyX-Code
-info registers - show content of all registers.
-\layout Subsubsection*
+SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
+\layout LyX-Code
-step
-\layout Standard
+SECTION NAME=bank1 RAM=gpr1 # should be added to link
+\layout LyX-Code
-Step program until it reaches a different source line.
- Note: pressing <return> repeats the last command.
-\layout Subsubsection*
+SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
+\layout LyX-Code
-next
-\layout Standard
+SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
+\layout LyX-Code
-Step program, proceeding through subroutine calls.
-\layout Subsubsection*
+SECTION NAME=bank4 RAM=gpr4
+\layout LyX-Code
-run
+SECTION NAME=bank5 RAM=gpr5
\layout Standard
-Start debugged program.
-\layout Subsubsection*
-
-ptype variable
-\layout Standard
+The linker will recognise the section name set in the pragma statement and
+ will position the variable at the memory bank set with the RAM field at
+ the SECTION line in the linker script file.
+\layout Subsection
-Print type information of the variable.
-\layout Subsubsection*
+Header Files
+\begin_inset LatexCommand \label{sub:PIC16_Header-Files}
-print variable
-\layout Standard
+\end_inset
-print value of variable.
-\layout Subsubsection*
-file filename
\layout Standard
-load the given file name.
- Note this is an alternate method of loading file for debugging.
-\layout Subsubsection*
+There is one main header file
+\begin_inset LatexCommand \index{PIC16!Header files}
-frame
-\layout Standard
+\end_inset
-print information about current frame.
-\layout Subsubsection*
+ that can be included to the source files using the pic16
+\begin_inset LatexCommand \index{PIC16}
-set srcmode
-\layout Standard
+\end_inset
-Toggle between C source & assembly source.
-\layout Subsubsection*
+ port.
+ That file is the
+\series bold
+pic18fregs.h
+\series default
+.
+ This header file contains the definitions for the processor special registers,
+ so it is necessary if the source accesses them.
+ It can be included by adding the following line in the beginning of the
+ file:
+\layout LyX-Code
-! simulator command
+#include <pic18fregs.h>
\layout Standard
-Send the string following '!' to the simulator, the simulator response is
- displayed.
- Note the debugger does not interpret the command being sent to the simulator,
- so if a command like 'go' is sent the debugger can loose its execution
- context and may display incorrect values.
-\layout Subsubsection*
+The specific microcontroller is selected within the pic18fregs.h automatically,
+ so the same source can be used with a variety of devices.
+\layout Subsection
-quit
+Libraries
\layout Standard
-"Watch me now.
- Iam going Down.
- My name is Bobby Brown"
-\layout Subsection
+The libraries
+\begin_inset LatexCommand \index{PIC16!Libraries}
-Interfacing SDCDB with DDD
-\layout Comment
-
-The screenshot was converted from png to eps with:
-\begin_inset Quotes sld
\end_inset
-bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps
-\begin_inset Quotes srd
-\end_inset
+ that PIC16
+\begin_inset LatexCommand \index{PIC16}
- which produces a pretty compact eps file which is free from compression
- artifacts.
-\layout Comment
+\end_inset
-The screenshot was included in sdccman.lyx cvs version 1.120 but later removed
- as this broke the build system on Sourceforge (pdf-file was broken).
+ port depends on are the microcontroller device libraries which contain
+ the symbol definitions for the microcontroller special function registers.
+ These libraries have the format pic18fxxxx.lib, where
+\emph on
+xxxx
+\emph default
+ is the microcontroller identification number.
+ The specific library is selected automatically by the compiler at link
+ stage according to the selected device.
\layout Standard
-The .eps File
-\size footnotesize
-
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.eps}
+Libraries are created with gplib which is part of the gputils package
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
\end_inset
+.
+\layout Subsubsection*
-\size default
- shows a screenshot of a debugging session with DDD
-\begin_inset LatexCommand \index{DDD (debugger)}
+Building the libraries
+\layout Standard
-\end_inset
+Before using SDCC/pic16 there are some libraries that need to be compiled.
+ This process is not done automatically by SDCC since not all users use
+ SDCC for pic16 projects.
+ So each user should compile the libraries separately.
+\layout Standard
- (Unix only) on a simulated 8032.
- The debugging session might not run as smoothly as the screenshot suggests.
- The debugger allows setting of breakpoints, displaying and changing variables,
- single stepping through C and assembler code.
-
-\newline
-The source was compiled with
-\family sans
-\series bold
+The steps to compile the pic16 libraries under Linux are:
+\layout LyX-Code
-\newline
+cd device/lib/pic16
+\layout LyX-Code
-\newline
-sdcc -
-\family default
-\series default
+./configure
+\layout LyX-Code
-\begin_inset ERT
-status Collapsed
+make
+\layout LyX-Code
+
+cd ..
+\layout LyX-Code
+
+make model-pic16
+\layout LyX-Code
+su -c 'make install' # install the libraries, you need the root password
\layout Standard
-\backslash
-/
-\end_inset
+If you need to install the headers too, do:
+\layout LyX-Code
+
+cd device/include
+\layout LyX-Code
+su -c 'make install' # install the headers, you need the root password
+\layout Standard
-\family sans
+There exist a special target to build the I/O libraries.
+ This target is not automatically build because it will build the I/O library
+ for
+\emph on
+every
+\emph default
+ supported device.
+ This way building will take quite a lot of time.
+ Users are advised to edit the
\series bold
--debug ddd_example.c
-\family default
+device/lib/pic16/pics.build
\series default
-
-\family sans
-\series bold
+ file and then execute:
+\layout LyX-Code
-\newline
+make lib-io
+\layout Subsection
-\family default
-\series default
+Memory Models
+\layout Standard
-\newline
-and DDD was invoked with
-\family sans
-\series bold
+The following memory models are supported by the PIC16 port:
+\layout Itemize
-\newline
+small model
+\layout Itemize
-\newline
-ddd -debugger 'sdcdb -cpu 8032 ddd_example'
-\layout Subsection
+large model
+\layout Standard
-Interfacing SDCDB with XEmacs
-\begin_inset LatexCommand \index{XEmacs}
+Memory model affects the default size of pointers within the source.
+ The sizes are shown in the next table:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+Pointer sizes according to memory model
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+small model
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\begin_inset LatexCommand \index{Emacs}
+\layout Standard
+large model
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+code pointers
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-Two files (in emacs lisp) are provided for the interfacing with XEmacs,
- sdcdb.el and sdcdbsrc.el.
- These two files can be found in the $(prefix)/bin directory after the installat
-ion is complete.
- These files need to be loaded into XEmacs for the interface to work.
- This can be done at XEmacs startup time by inserting the following into
- your '.xemacs' file (which can be found in your HOME directory):
-\newline
+16-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-(load-file sdcdbsrc.el)
-\family default
+24-bits
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\newline
-.xemacs is a lisp file so the () around the command is REQUIRED.
- The files can also be loaded dynamically while XEmacs is running, set the
- environment variable 'EMACSLOADPATH' to the installation bin directory
- (<installdir>/bin), then enter the following command ESC-x load-file sdcdbsrc.
- To start the interface enter the following command:
-\newline
+data pointers
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family sans
+16-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+It is advisable that all sources within a project are compiled with the
+ same memory model.
+ If one wants to override the default memory model, this can be done by
+ declaring a pointer as
\series bold
-ESC-x sdcdbsrc
-\family default
+far
+\series default
+ or
+\series bold
+near
\series default
+.
+ Far selects large memory model's pointers, while near selects small memory
+ model's pointers.
+\layout Standard
-\newline
+The standard device libraries (see
+\begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
-\newline
-You will prompted to enter the file name to be debugged.
-
-\newline
+\end_inset
-\newline
-The command line options that are passed to the simulator directly are bound
- to default values in the file sdcdbsrc.el.
- The variables are listed below, these values maybe changed as required.
-\layout Itemize
+) contain no reference to pointers, so they can be used with both memory
+ models.
+\layout Subsection
-sdcdbsrc-cpu-type '51
+Stack
+\layout Standard
+
+The stack
+\begin_inset LatexCommand \index{PIC16!stack}
+
+\end_inset
+
+ implementation for the PIC16 port uses two indirect registers, FSR1 and
+ FSR2.
+\layout List
+\labelwidthstring 00.00.0000
+
+FSR1 is assigned as stack pointer
+\layout List
+\labelwidthstring 00.00.0000
+
+FSR2 is assigned as frame pointer
+\layout Standard
+
+The following stack models are supported by the PIC16 port
\layout Itemize
-sdcdbsrc-frequency '11059200
+
+\noun on
+small
+\noun default
+ model
\layout Itemize
-sdcdbsrc-serial nil
+
+\noun on
+large
+\noun default
+ model
\layout Standard
-The following is a list of key mapping for the debugger interface.
+
+\noun on
+Small
+\noun default
+ model means that only the FSRxL byte is used to access stack and frame,
+ while
+\emph on
+\noun on
+large
+\emph default
+\noun default
+ uses both FSRxL and FSRxH registers.
+ The following table shows the stack/frame pointers sizes according to stack
+ model and the maximum space they can address:
\layout Standard
+\align center
-\SpecialChar ~
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
+\layout Standard
+Stack & Frame pointer sizes according to stack model
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+small
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+large
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Stack pointer FSR1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Frame pointer FSR2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+
+\noun on
+Large
+\noun default
+stack model is currently not working properly throughout the code generator.
+ So its use is not advised.
+ Also there are some other points that need special care:
\newline
-;;\SpecialChar ~
-Current Listing ::
-\newline
-;;key\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-binding\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-Comment
-\newline
-;;---\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
--------\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
--------
-\newline
-;;
-\newline
-;;\SpecialChar ~
-n\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-next-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-SDCDB next command
-\newline
-;;\SpecialChar ~
-b\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-back-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-SDCDB back command
-\newline
-;;\SpecialChar ~
-c\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-cont-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-SDCDB continue command
-\newline
-;;\SpecialChar ~
-s\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-step-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-SDCDB step command
-\newline
-;;\SpecialChar ~
-?\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-whatis-c-sexp\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+
+\layout Enumerate
+
+Do not create stack sections with size more than one physical bank (that
+ is 256 bytes)
+\layout Enumerate
+
+Stack sections should no cross physical bank limits (i.e.
+ #pragma stack 0x50 0x100)
+\layout Standard
+
+These limitations are caused by the fact that only FSRxL is modified when
+ using SMALL stack model, so no more than 256 bytes of stack can be used.
+ This problem will disappear after LARGE model is fully implemented.
+\layout Subsection
+
+Functions
+\layout Standard
+
+In addition to the standard SDCC function keywords, PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port makes available two more:
+\layout List
+\labelwidthstring 00.00.0000
+
+wparam
+\begin_inset LatexCommand \index{PIC16!wparam}
+
+\end_inset
+
+ Use the WREG to pass one byte of the first function argument.
+ This improves speed but you may not use this for functions with arguments
+ that are called via function pointers, otherwise the first byte of the
+ first parameter will get lost.
+ Usage:
+\layout LyX-Code
+
+void func_wparam(int a) wparam
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ /* WREG hold the lower part of a */
+\layout LyX-Code
+
+ /* the high part of a is stored in FSR2+2 (or +3 for large stack model)
+ */
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout List
+\labelwidthstring 00.00.0000
+
+shadowregs
+\begin_inset LatexCommand \index{PIC16!shadowregs}
+
+\end_inset
+
+ When entering/exiting an ISR, it is possible to take advantage of the PIC18F
+ hardware shadow registers which hold the values of WREG, STATUS and BSR
+ registers.
+ This can be done by adding the keyword
+\emph on
+shadowregs
+\emph default
+ before the
+\emph on
+interrupt
+\emph default
+ keyword in the function's header.
+\layout LyX-Code
+
+void isr_shadow(void) shadowregs interrupt 1
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\emph on
+shadowregs
+\emph default
+ instructs the code generator not to store/restore WREG, STATUS, BSR when
+ entering/exiting the ISR.
+\layout Subsection
+
+Function return values
+\layout Standard
+
+Return values from functions are placed to the appropriate registers following
+ a modified Microchip policy optimized for SDCC.
+ The following table shows these registers:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+size
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+destination register
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+24 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PRODH:PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+32 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+FSR0L:PRODH:PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+>32 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+on stack, FSR0 points to the beginning
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Subsection
+
+Interrupts
+\layout Standard
+
+An interrupt
+\begin_inset LatexCommand \index{PIC16!interrupt}
+
+\end_inset
+
+ service routine (ISR) is declared using the
+\emph on
+interrupt
+\emph default
+ keyword.
+\layout LyX-Code
+
+void isr(void) interrupt
+\emph on
+n
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is the interrupt number, which for PIC18F devices can be:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+n
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector Address
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+RESET vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000000
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+HIGH priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000008
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+LOW priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000018
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+When generating assembly code for ISR the code generator places a
+\noun on
+goto
+\noun default
+instruction at the
+\emph on
+Interrupt Vector Address
+\emph default
+ which points at the genetated ISR.
+ This single GOTO instruction is part of an automatically generated
+\emph on
+interrupt entry point
+\emph default
+ function.
+ The actuall ISR code is placed as normally would in the code space.
+ Upon interrupt request, the GOTO instruction is executed which jumps to
+ the ISR code.
+ When declaring interrupt functions as _naked this GOTO instruction is
+\series bold
+not
+\series default
+ generated.
+ The whole interrupt functions is therefore placed at the Interrupt Vector
+ Address of the specific interrupt.
+ This is not a problem for the LOW priority interrupts, but it is a problem
+ for the RESET and the HIGH priority interrupts because code may be written
+ at the next interrupt´s vector address and cause undeterminate program
+ behaviour if that interrupt is raised.
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+This is not a problem when
+\layout Enumerate
+
+this is a HIGH interrupt ISR and LOW interrupts are
+\emph on
+disabled
+\emph default
+ or not used.
+\layout Enumerate
+
+when the ISR is small enough not to reach the next interrupt´s vector address.
+\end_inset
+
+
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is possible to be omitted.
+ This way a function is generated similar to an ISR, but it is not assigned
+ to any interrupt.
+\layout Standard
+
+When entering an interrupt, currently the PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port automatically saves the following registers:
+\layout Itemize
+
+WREG
+\layout Itemize
+
+STATUS
+\layout Itemize
+
+BSR
+\layout Itemize
+
+PROD (PRODL and PRODH)
+\layout Itemize
+
+FSR0 (FSR0L and FSR0H)
+\layout Standard
+
+These registers are restored upon return from the interrupt routine.
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+NOTE that when the _naked attribute is specified for an interrupt routine,
+ then NO registers are stored or restored.
+\end_inset
+
+
+\layout Subsection
+
+Generic Pointers
+\layout Standard
+
+Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types.
+ There are 3 types of generic pointers currently implemented data, code
+ and eeprom pointers.
+ They are differentiated by the value of the 7th and 6th bits of the upper
+ byte:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="5" columns="5">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="left" valignment="top" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+pointer type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+7th bit
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+6th bit
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+rest of the pointer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+description
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+data
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuu uuuuxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 12-bit data pointer in data RAM memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+code
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uxxxxx xxxxxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 21-bit code pointer in FLASH memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+eeprom
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuu uuuuuuxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 10-bit eeprom pointer in EEPROM memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+(unimplemented)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+xxxxxx xxxxxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+unimplemented pointer type
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+Generic pointer are read and written with a set of library functions which
+ read/write 1, 2, 3, 4 bytes.
+\layout Subsection
+
+PIC16 C Libraries
+\layout Subsubsection
+
+Standard I/O Streams
+\layout Standard
+
+In the
+\emph on
+stdio.h
+\emph default
+ the type FILE is defined as:
+\layout LyX-Code
+
+typedef char * FILE;
+\layout Standard
+
+This type is the stream type implemented I/O in the PIC18F devices.
+ Also the standard input and output streams are declared in stdio.h:
+\layout LyX-Code
+
+extern FILE * stdin;
+\layout LyX-Code
+
+extern FILE * stdout;
+\layout Standard
+
+The FILE type is actually a generic pointer which defines one more type
+ of generic pointers, the
+\emph on
+stream
+\emph default
+pointer.
+ This new type has the format:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="2" columns="7">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="left" valignment="top" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+pointer type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<7:6>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<5>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<4>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<3:0>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+rest of the pointer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+descrption
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+stream
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+00
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+nnnn
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuuuu uuuuuuuu
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+upper byte high nubble is 0x2n, the rest are zeroes
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+Currently implemented there are 3 types of streams defined:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="4">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+stream type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+value
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+module
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_USART
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x200000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via the USART peripheral
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x210000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via the MSSP peripheral
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_USER
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x2f0000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+(none)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via used defined functions
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+The stream identifiers are declared as macros in the stdio.h header.
+\layout Standard
+
+In the libc library there exist the functions that are used to write to
+ each of the above streams.
+ These are
+\layout List
+\labelwidthstring 00.00.0000
+
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_stream_usart_putchar writes a character at the USART stream
+\layout List
+\labelwidthstring 00.00.0000
+
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_stream_mssp_putchar writes a character at the MSSP stream
+\layout List
+\labelwidthstring 00.00.0000
+
+putchar dummy function.
+ This writes a character to a user specified manner.
+\layout Standard
+
+In order to increase performance
+\emph on
+putchar
+\emph default
+is declared in stdio.h as having its parameter in WREG (it has the wparam
+ keyword).
+ In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function
+ in a user-friendly way.
+
+\emph on
+arg
+\emph default
+ is the name of the variable that holds the character to print.
+ An example follows:
+\layout LyX-Code
+
+#include <pic18fregs.h>
+\newline
+#include <stdio.h>
+\newline
+
+\newline
+PUTCHAR( c )
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ PORTA = c; /* dump character c to PORTA */
+\layout LyX-Code
+
+}
+\newline
+
+\newline
+void main(void)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ stdout = STREAM_USER; /* this is not necessary, since stdout points
+\layout LyX-Code
+
+ * by default to STREAM_USER */
+\layout LyX-Code
+
+ printf (¨This is a printf test
+\backslash
+n¨);
+\layout LyX-Code
+
+}
+\layout LyX-Code
+
+\layout Subsubsection
+
+Printing functions
+\layout Standard
+
+PIC16 contains an implementation of the printf-family of functions.
+ There exist the following functions:
+\layout LyX-Code
+
+extern unsigned int sprintf(char *buf, char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vsprintf(char *buf, char *fmt, va_list ap);
+\layout LyX-Code
+
+\layout LyX-Code
+
+extern unsigned int printf(char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vprintf(char *fmt, va_lista ap);
+\layout LyX-Code
+
+\layout LyX-Code
+
+extern unsigned int fprintf(FILE *fp, char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap);
+\layout Standard
+
+For sprintf and vsprintf
+\emph on
+buf
+\emph default
+should normally be a data pointer where the resulting string will be placed.
+ No range checking is done so the user should allocate the necessery buffer.
+ For fprintf and vfprintf
+\emph on
+fp
+\emph default
+ should be a stream pointer (i.e.
+ stdout, STREAM_MSSP, etc...).
+\layout Subsubsection
+
+Signals
+\layout Standard
+
+The PIC18F family of microcontrollers supports a number of interrupt sources.
+ A list of these interrupts is shown in the following table:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="11" columns="4">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+signal name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+signal name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+descritpion
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_RB
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PORTB change interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_EE
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+EEPROM/FLASH write complete interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT0 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_BCOL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Bus collision interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT1 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_LVD
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Low voltage detect interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT2 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_PSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Parallel slave port interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_CCP1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+CCP1 module interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_AD
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+AD convertion complete interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_CCP2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+CCP2 module interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_RC
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART receive interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR0 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART transmit interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR1 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SSP receive/transmit interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR2 matches PR2 interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR3
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR3 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+The prototypes for these names are defined in the header file
+\emph on
+signal.h
+\emph default
+ .
+\layout Standard
+
+In order to simplify signal handling, a number of macros is provided:
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
+ high priority interrupts.
+
+\emph on
+name
+\emph default
+ is the function name to use.
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
+ low priority interrupt.
+
+\emph on
+name
+\emph default
+ is the function name to use.
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_HANDLER(sig,handler) define a handler for signal
+\emph on
+sig.
+\layout List
+\labelwidthstring 00.00.0000
+
+END_DEF end the declaration of the dispatch table.
+\layout Standard
+
+Additionally there are two more macros to simplify the declaration of the
+ signal handler:
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series medium
+SIGHANDLER(handler)
+\series default
+this declares the function prototype for the
+\emph on
+handler
+\emph default
+ function.
+\layout List
+\labelwidthstring 00.00.0000
+
+SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function.
+\layout Standard
+
+An example of using the macros above is shown below:
+\layout LyX-Code
+
+#include <pic18fregs.h>
+\layout LyX-Code
+
+#include <signal.h>
+\newline
+
+\newline
+DEF_INTHIGH(high_int)
+\layout LyX-Code
+
+DEF_HANDLER(SIG_TMR0, _tmr0_handler)
+\layout LyX-Code
+
+DEF_HANDLER(SIG_BCOL, _bcol_handler)
+\layout LyX-Code
+
+END_DEF
+\newline
+
+\newline
+SIGHANDLER(_tmr0_handler)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ /* action to be taken when timer 0 overflows */
+\layout LyX-Code
+
+}
+\newline
+
+\newline
+SIGHANDLERNAKED(_bcol_handler)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ _asm
+\layout LyX-Code
+
+ /* action to be taken when bus collision occurs */
+\layout LyX-Code
+
+ retfie
+\layout LyX-Code
+
+ _endasm;
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\series bold
+NOTES:
+\series default
+ Special care should be taken when using the above scheme:
+\layout Itemize
+
+do not place a colon (;) at the end of the DEF_* and END_DEF macros.
+\layout Itemize
+
+when declaring SIGHANDLERNAKED handler never forget to use
+\emph on
+retfie
+\emph default
+ for proper returning.
+\layout Subsection
+
+PIC16 Port -- Tips
+\layout Standard
+
+Here you can find some general tips for compiling programs with SDCC/pic16.
+\layout Subsubsection
+
+Stack size
+\layout Standard
+
+The default stack
+\begin_inset LatexCommand \index{PIC16!stack}
+
+\end_inset
+
+ size (that is 64 bytes) probably is enough for many programs.
+ One must take care that when there are many levels of function nesting,
+ or there is excessive usage of stack, its size should be extended.
+ An example of such a case is the printf/sprintf family of functions.
+ If you encounter problems like not being able to print integers, then you
+ need to set the stack size around the maximum (256 for small stack model).
+ The following diagram shows what happens when calling printf to print an
+ integer:
+\layout LyX-Code
+
+printf () --> ltoa () --> ultoa () --> divschar ()
+\layout Standard
+
+It is should be understood that stack is easily consumed when calling complicate
+d functions.
+ Using command line arguments like -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-fommit-frame-pointer might reduce stack usage by not creating unnecessery
+ stack frames.
+ Other ways to reduce stack usage may exist.
+\layout Subsection
+
+Known bugs
+\layout Standard
+
+The PIC16 Port currently does not pass SDCC's regression test
+\begin_inset LatexCommand \index{Regression test (PIC16)}
+
+\end_inset
+
+ suite (see section
+\begin_inset LatexCommand \ref{sec:Quality-control}
+
+\end_inset
+
+) and thus the nightly regression tests for the PIC16 target are currently
+ disabled for all hosts except for
+\emph on
+Linux on Opteron.
+
+\emph default
+ This means you can see the result of the PIC16 regression tests f.e.
+ by checking the log files in
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/regression_test_results/amd64-unknown-linux2.3/}
+
+\end_inset
+
+ (pick the most up to date file there, scroll down, lend a hand).
+\layout Chapter
+
+Debugging
+\layout Standard
+
+There are several approaches to debugging your code.
+ This chapter is meant to show your options and to give detail on some of
+ them:
+\newline
+
+\newline
+When writing your code:
+\layout Itemize
+
+write your code with debugging in mind (avoid duplicating code, put conceptually
+ similar variables into structs, use structured code, have strategic points
+ within your code where all variables are consistent, ...)
+\layout Itemize
+
+run a syntax-checking tool like splint
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{lint (syntax checking tool)}
+
+\end_inset
+
+ (see -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-more-pedantic
+\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+
+\end_inset
+
+) over the code.
+\layout Itemize
+
+for the high level code use a C-compiler (like f.e.
+ GCC) to compile run and debug the code on your host.
+ See (see -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-more-pedantic
+\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+
+\end_inset
+
+ ) on howto handle syntax extensions like __xdata, __at(), ...
+
+\layout Itemize
+
+use another C-compiler to compile code for your target.
+ Always an option but not recommended:) And not very likely to help you.
+ If you seriously consider walking this path you should at least occasionally
+ check portability of your code.
+ Most commercial compiler vendors will offer an evaluation version so you
+ can test compile your code or snippets of your code.
+\layout Standard
+
+Debugging on a simulator:
+\layout Itemize
+
+there is a separate section about SDCDB (section
+\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
+
+\end_inset
+
+) below.
+\layout Itemize
+
+or (8051 specific) use a freeware/commercial simulator which interfaces
+ to the AOMF
+\begin_inset LatexCommand \index{AOMF, AOMF51}
+
+\end_inset
+
+ file (see
+\begin_inset LatexCommand \ref{OMF file}
+
+\end_inset
+
+) optionally generated by SDCC.
+\layout Standard
+
+Debugging On-target:
+\layout Itemize
+
+use a MCU port pin to serially output debug data to the RS232 port of your
+ host.
+ You'll probably want some level shifting device typically involving a MAX232
+ or similar IC.
+ If the hardware serial port of the MCU is not available search for 'Software
+ UART' in your favourite search machine.
+\layout Itemize
+
+use an on-target monitor.
+ In this context a monitor is a small program which usually accepts commands
+ via a serial line and allows to set program counter, to single step through
+ a program and read/write memory locations.
+ For the 8051 good examples of monitors are paulmon and cmon51 (see section
+
+\begin_inset LatexCommand \ref{sec:Related-open-source-tools}
+
+\end_inset
+
+).
+\layout Itemize
+
+toggle MCU port pins at strategic points within your code and use an oscilloscop
+e.
+ A
+\emph on
+digital oscilloscope
+\emph default
+
+\begin_inset LatexCommand \index{Oscilloscope}
+
+\end_inset
+
+ with deep trace memory is really helpful especially if you have to debug
+ a realtime application.
+ If you need to monitor more pins than your oscilloscope provides you can
+ sometimes get away with a small R-2R network.
+ On a single channel oscilloscope you could f.e.
+ monitor 2 push-pull driven pins by connecting one via a 10\SpecialChar ~
+k
+\begin_inset Formula $\Omega$
+\end_inset
+
+ resistor and the other one by a 5\SpecialChar ~
+k
+\begin_inset Formula $\Omega$
+\end_inset
+
+ resistor to the oscilloscope probe (check output drive capability of the
+ pins you want to monitor).
+ If you need to monitor many more pins a
+\emph on
+logic analyzer
+\emph default
+ will be handy.
+\layout Itemize
+
+use an ICE (
+\emph on
+i
+\emph default
+n
+\emph on
+c
+\emph default
+ircuit
+\emph on
+e
+\emph default
+mulator
+\begin_inset LatexCommand \index{ICE (in circuit emulator)}
+
+\end_inset
+
+).
+ Usually very expensive.
+ And very nice to have too.
+ And usually locks you (for years...) to the devices the ICE can emulate.
+
+\layout Itemize
+
+use a remote debugger.
+ In most 8-bit systems the symbol information is not available on the target,
+ and a complete debugger is too bulky for the target system.
+ Therefore usually a debugger on the host system connects to an on-target
+ debugging stub which accepts only primitive commands.
+
+\newline
+Terms to enter into your favourite search engine could be 'remote debugging',
+ 'gdb stub' or 'inferior debugger'.
+ (is there one?)
+\layout Itemize
+
+use an on target hardware debugger.
+ Some of the more modern MCUs include hardware support for setting break
+ points and monitoring/changing variables by using dedicated hardware pins.
+ This facility doesn't require additional code to run on the target and
+
+\emph on
+usually
+\emph default
+ doesn't affect runtime behaviour until a breakpoint is hit.
+ For the mcs51 most hardware debuggers use the AOMF
+\begin_inset LatexCommand \index{AOMF, AOMF51}
+
+\end_inset
+
+ file (see
+\begin_inset LatexCommand \ref{OMF file}
+
+\end_inset
+
+) as input file.
+
+\layout Standard
+
+Last not least:
+\layout Itemize
+
+if you are not familiar with any of the following terms you're likely to
+ run into problems rather sooner than later:
+\emph on
+volatile
+\emph default
+,
+\emph on
+atomic
+\emph default
+,
+\emph on
+memory map
+\emph default
+,
+\emph on
+overlay
+\emph default
+.
+ As an embedded programmer you
+\emph on
+have
+\emph default
+ to know them so why not look them up
+\emph on
+before
+\emph default
+ you have problems?)
+\layout Itemize
+
+tell someone else about your problem (actually this is a surprisingly effective
+ means to hunt down the bug even if the listener is not familiar with your
+ environment).
+ As 'failure to communicate' is probably one of the job-induced deformations
+ of an embedded programmer this is highly encouraged.
+\layout Section
+
+Debugging with SDCDB
+\begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{SDCDB (debugger)}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC is distributed with a source level debugger
+\begin_inset LatexCommand \index{Debugger}
+
+\end_inset
+
+.
+ The debugger uses a command line interface, the command repertoire of the
+ debugger has been kept as close to gdb
+\begin_inset LatexCommand \index{gdb}
+
+\end_inset
+
+ (the GNU debugger) as possible.
+ The configuration and build process is part of the standard compiler installati
+on, which also builds and installs the debugger in the target directory
+ specified during configuration.
+ The debugger allows you debug BOTH at the C source and at the ASM source
+ level.
+\layout Subsection
+
+Compiling for Debugging
+\layout Standard
+
+The -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+ option must be specified for all files for which debug information is to
+ be generated.
+ The compiler generates a .adb file for each of these files.
+ The linker creates the .cdb
+\begin_inset LatexCommand \index{<file>.cdb}
+
+\end_inset
+
+ file from the .adb
+\begin_inset LatexCommand \index{<file>.adb}
+
+\end_inset
+
+ files and the address information.
+ This .cdb is used by the debugger.
+\layout Subsection
+
+How the Debugger Works
+\layout Standard
+
+When the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug option is specified the compiler generates extra symbol information
+ some of which are put into the assembler source and some are put into the
+ .adb file.
+ Then the linker creates the .cdb file from the individual .adb files with
+ the address information for the symbols.
+ The debugger reads the symbolic information generated by the compiler &
+ the address information generated by the linker.
+ It uses the SIMULATOR (Daniel's S51) to execute the program, the program
+ execution is controlled by the debugger.
+ When a command is issued for the debugger, it translates it into appropriate
+ commands for the simulator.
+ (Currently SDCDM only connects to the simulator but
+\emph on
+newcdb
+\emph default
+ at
+\begin_inset LatexCommand \url{http://ec2drv.sf.net/}
+
+\end_inset
+
+ is an effort to connect directly to the hardware.)
+\layout Subsection
+
+Starting the Debugger SDCDB
+\layout Standard
+
+The debugger can be started using the following command line.
+ (Assume the file you are debugging has the file name foo).
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb foo
+\newline
+
+\family default
+\series default
+
+\newline
+The debugger will look for the following files.
+\layout Itemize
+
+foo.c - the source file.
+\layout Itemize
+
+foo.cdb - the debugger symbol information file.
+\layout Itemize
+
+foo.ihx - the Intel hex format
+\begin_inset LatexCommand \index{Intel hex format}
+
+\end_inset
+
+ object file.
+\layout Subsection
+
+SDCDB Command Line Options
+\layout Itemize
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory=<source file directory> this option can used to specify the directory
+ search list.
+ The debugger will look into the directory list specified for source, cdb
+ & ihx files.
+ The items in the directory list must be separated by ':', e.g.
+ if the source files can be in the directories /home/src1 and /home/src2,
+ the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory option should be -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory=/home/src1:/home/src2.
+ Note there can be no spaces in the option.
+
+\layout Itemize
+
+-cd <directory> - change to the <directory>.
+\layout Itemize
+
+-fullname - used by GUI front ends.
+\layout Itemize
+
+-cpu <cpu-type> - this argument is passed to the simulator please see the
+ simulator docs for details.
+\layout Itemize
+
+-X <Clock frequency > this options is passed to the simulator please see
+ the simulator docs for details.
+\layout Itemize
+
+-s <serial port file> passed to simulator see the simulator docs for details.
+\layout Itemize
+
+-S <serial in,out> passed to simulator see the simulator docs for details.
+\layout Itemize
+
+-k <port number> passed to simulator see the simulator docs for details.
+\layout Subsection
+
+SDCDB Debugger Commands
+\layout Standard
+
+As mentioned earlier the command interface for the debugger has been deliberatel
+y kept as close the GNU debugger gdb, as possible.
+ This will help the integration with existing graphical user interfaces
+ (like ddd, xxgdb or xemacs) existing for the GNU debugger.
+ If you use a graphical user interface for the debugger you can skip this
+ section.
+\layout Subsubsection*
+
+break [line | file:line | function | file:function]
+\layout Standard
+
+Set breakpoint at specified line or function:
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb>break 100
+\newline
+sdcdb>break foo.c:100
+\newline
+sdcdb>break funcfoo
+\newline
+sdcdb>break foo.c:funcfoo
+\layout Subsubsection*
+
+clear [line | file:line | function | file:function ]
+\layout Standard
+
+Clear breakpoint at specified line or function:
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb>clear 100
+\newline
+sdcdb>clear foo.c:100
+\newline
+sdcdb>clear funcfoo
+\newline
+sdcdb>clear foo.c:funcfoo
+\layout Subsubsection*
+
+continue
+\layout Standard
+
+Continue program being debugged, after breakpoint.
+\layout Subsubsection*
+
+finish
+\layout Standard
+
+Execute till the end of the current function.
+\layout Subsubsection*
+
+delete [n]
+\layout Standard
+
+Delete breakpoint number 'n'.
+ If used without any option clear ALL user defined break points.
+\layout Subsubsection*
+
+info [break | stack | frame | registers ]
+\layout Itemize
+
+info break - list all breakpoints
+\layout Itemize
+
+info stack - show the function call stack.
+\layout Itemize
+
+info frame - show information about the current execution frame.
+\layout Itemize
+
+info registers - show content of all registers.
+\layout Subsubsection*
+
+step
+\layout Standard
+
+Step program until it reaches a different source line.
+ Note: pressing <return> repeats the last command.
+\layout Subsubsection*
+
+next
+\layout Standard
+
+Step program, proceeding through subroutine calls.
+\layout Subsubsection*
+
+run
+\layout Standard
+
+Start debugged program.
+\layout Subsubsection*
+
+ptype variable
+\layout Standard
+
+Print type information of the variable.
+\layout Subsubsection*
+
+print variable
+\layout Standard
+
+print value of variable.
+\layout Subsubsection*
+
+file filename
+\layout Standard
+
+load the given file name.
+ Note this is an alternate method of loading file for debugging.
+\layout Subsubsection*
+
+frame
+\layout Standard
+
+print information about current frame.
+\layout Subsubsection*
+
+set srcmode
+\layout Standard
+
+Toggle between C source & assembly source.
+\layout Subsubsection*
+
+! simulator command
+\layout Standard
+
+Send the string following '!' to the simulator, the simulator response is
+ displayed.
+ Note the debugger does not interpret the command being sent to the simulator,
+ so if a command like 'go' is sent the debugger can loose its execution
+ context and may display incorrect values.
+\layout Subsubsection*
+
+quit
+\layout Standard
+
+"Watch me now.
+ Iam going Down.
+ My name is Bobby Brown"
+\layout Subsection
+
+Interfacing SDCDB with DDD
+\layout Standard
+
+
+\begin_inset Note
+collapsed true
+
+\layout Standard
+
+The screenshot was converted from png to eps with:
+\begin_inset Quotes sld
+\end_inset
+
+bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps
+\begin_inset Quotes srd
+\end_inset
+
+ which produces a pretty compact eps file which is free from compression
+ artifacts.
+\layout Standard
+
+The screenshot was included in sdccman.lyx cvs version 1.120 but later removed
+ as this broke the build system on Sourceforge (pdf-file was broken.
+ pdflatex does not accept eps files).
+\end_inset
+
+
+\layout Standard
+
+The
+\emph on
+p
+\emph default
+ortable
+\emph on
+n
+\emph default
+etwork
+\emph on
+g
+\emph default
+raphics File
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.png}
+
+\end_inset
+
+
+\size default
+ shows a screenshot of a debugging session with DDD
+\begin_inset LatexCommand \index{DDD (debugger)}
+
+\end_inset
+
+ (Unix only) on a simulated 8032.
+ The debugging session might not run as smoothly as the screenshot suggests.
+ The debugger allows setting of breakpoints, displaying and changing variables,
+ single stepping through C and assembler code.
+
+\newline
+The source was compiled with
+\family sans
+\series bold
+
+\newline
+
+\newline
+sdcc -
+\family default
+\series default
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\family sans
+\series bold
+-debug ddd_example.c
+\family default
+\series default
+
+\family sans
+\series bold
+
+\newline
+
+\family default
+\series default
+
+\newline
+and DDD was invoked with
+\family sans
+\series bold
+
+\newline
+
+\newline
+ddd -debugger "sdcdb -cpu 8032 ddd_example"
+\layout Standard
+
+
+\begin_inset Note
+collapsed false
+
+\layout Standard
+
+Check that the double quotes or an apostroph within the command line survive
+ the LyX tool chain.
+ Previously the apostrophs got slanted in the PDF output so a cut and paste
+ did not work.
+\end_inset
+
+
+\layout Subsection
+
+Interfacing SDCDB with XEmacs
+\begin_inset LatexCommand \index{XEmacs}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Emacs}
+
+\end_inset
+
+
+\layout Standard
+
+Two files (in emacs lisp) are provided for the interfacing with XEmacs,
+ sdcdb.el and sdcdbsrc.el.
+ These two files can be found in the $(prefix)/bin directory after the installat
+ion is complete.
+ These files need to be loaded into XEmacs for the interface to work.
+ This can be done at XEmacs startup time by inserting the following into
+ your '.xemacs' file (which can be found in your HOME directory):
+\newline
+
+\newline
+
+\family typewriter
+(load-file sdcdbsrc.el)
+\family default
+
+\newline
+
+\newline
+.xemacs is a lisp file so the () around the command is REQUIRED.
+ The files can also be loaded dynamically while XEmacs is running, set the
+ environment variable 'EMACSLOADPATH' to the installation bin directory
+ (<installdir>/bin), then enter the following command ESC-x load-file sdcdbsrc.
+ To start the interface enter the following command:
+\newline
+
+\newline
+
+\family sans
+\series bold
+ESC-x sdcdbsrc
+\family default
+\series default
+
+\newline
+
+\newline
+You will prompted to enter the file name to be debugged.
+
+\newline
+
+\newline
+The command line options that are passed to the simulator directly are bound
+ to default values in the file sdcdbsrc.el.
+ The variables are listed below, these values maybe changed as required.
+\layout Itemize
+
+sdcdbsrc-cpu-type '51
+\layout Itemize
+
+sdcdbsrc-frequency '11059200
+\layout Itemize
+
+sdcdbsrc-serial nil
+\layout Standard
+
+The following is a list of key mapping for the debugger interface.
+\layout Standard
+\pagebreak_bottom
+\SpecialChar ~
+
+\family typewriter
+
+\newline
+;;\SpecialChar ~
+Current Listing ::
+\newline
+;;key\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+binding\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Comment
+\newline
+;;---\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+-------\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+-------
+\newline
+;;
+\newline
+;;\SpecialChar ~
+n\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-next-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB next command
+\newline
+;;\SpecialChar ~
+b\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-back-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB back command
+\newline
+;;\SpecialChar ~
+c\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-cont-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB continue command
+\newline
+;;\SpecialChar ~
+s\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-step-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB step command
+\newline
+;;\SpecialChar ~
+?\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-whatis-c-sexp\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
buffer point
\newline
-;;\SpecialChar ~
-g\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdbsrc-goto-sdcdb\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+;;\SpecialChar ~
+g\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-goto-sdcdb\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Goto the SDCDB output buffer
+\newline
+;;\SpecialChar ~
+t\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-mode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Toggles Sdcdbsrc mode (turns it off)
+\newline
+;;
+\newline
+;;\SpecialChar ~
+C-c\SpecialChar ~
+C-f\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-finish-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB finish command
+\newline
+;;
+\newline
+;;\SpecialChar ~
+C-x\SpecialChar ~
+SPC\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-break\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Set break for line with point
+\newline
+;;\SpecialChar ~
+ESC\SpecialChar ~
+t\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-mode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Toggle Sdcdbsrc mode
+\newline
+;;\SpecialChar ~
+ESC\SpecialChar ~
+m\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-srcmode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Toggle list mode
+\newline
+;;
+\newline
+
+\layout Chapter
+
+TIPS
+\layout Standard
+
+Here are a few guidelines that will help the compiler generate more efficient
+ code, some of the tips are specific to this compiler others are generally
+ good programming practice.
+\layout Itemize
+
+Use the smallest data type to represent your data-value.
+ If it is known in advance that the value is going to be less than 256 then
+ use an 'unsigned char' instead of a 'short' or 'int'.
+ Please note, that ANSI C requires both signed and unsigned chars to be
+ promoted to 'signed int'
+\begin_inset LatexCommand \index{promotion to signed int}
+
+\end_inset
+
+
+\begin_inset Marginal
+collapsed true
+
+\layout Standard
+
+
+\series bold
+\SpecialChar ~
+!
+\end_inset
+
+ before doing any operation.
+ This promotion
+\begin_inset LatexCommand \index{type promotion}
+
+\end_inset
+
+
+\begin_inset LatexCommand \label{type promotion}
+
+\end_inset
+
+ can be omitted, if the result is the same.
+ The effect of the promotion rules together with the sign-extension is often
+ surprising:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+unsigned char uc = 0xfe;
+\newline
+if (uc * uc < 0) /* this is true! */
+\newline
+{
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-Goto the SDCDB output buffer
+....
+\newline
+}
+\layout Standard
+
+
+\family typewriter
+uc * uc
+\family default
+ is evaluated as
+\family typewriter
+(int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
+\family default
+.
+
+\newline
+Another one:
+\layout Verse
+
+
+\family typewriter
+(unsigned char) -12 / (signed char) -3 = ...
+\layout Standard
+
+No, the result is not 4:
+\layout Verse
+
+
+\family typewriter
+(int) (unsigned char) -12 / (int) (signed char) -3 =
+\newline
+(int) (unsigned char) 0xf4 / (int) (signed char) 0xfd =
+\newline
+(int) 0x00f4 / (int) 0xfffd =
+\newline
+(int) 0x00f4 / (int) 0xfffd =
+\newline
+(int) 244 / (int) -3 =
+\newline
+(int) -81 = (int) 0xffaf;
+\layout Standard
+
+Don't complain, that gcc gives you a different result.
+ gcc uses 32 bit ints, while SDCC uses 16 bit ints.
+ Therefore the results are different.
+\newline
+From
+\begin_inset Quotes sld
+\end_inset
+
+comp.lang.c FAQ
+\begin_inset Quotes srd
+\end_inset
+
+:
+\layout Quote
+
+
+\emph on
+If well-defined overflow characteristics are important and negative values
+ are not, or if you want to steer clear of sign-extension problems when
+ manipulating bits or bytes, use one of the corresponding unsigned types.
+ (Beware when mixing signed and unsigned values in expressions, though.)
+\newline
+Although character types (especially unsigned char) can be used as "tiny"
+ integers, doing so is sometimes more trouble than it's worth, due to unpredicta
+ble sign extension and increased code size.
+\end_deeper
+\layout Itemize
+
+Use unsigned when it is known in advance that the value is not going to
+ be negative.
+ This helps especially if you are doing division or multiplication, bit-shifting
+ or are using an array index.
+\layout Itemize
+
+NEVER jump into a LOOP.
+\layout Itemize
+
+Declare the variables to be local
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ whenever possible, especially loop control variables (induction).
+\layout Itemize
+
+Have a look at the assembly listing to get a
+\begin_inset Quotes sld
+\end_inset
+
+feeling
+\begin_inset Quotes srd
+\end_inset
+
+ for the code generation.
+\layout Section
+
+Porting code from or to other compilers
+\begin_inset LatexCommand \label{sec:Porting-code-to-other-compilers}
+
+\end_inset
+
+
+\layout Itemize
+
+check whether endianness of the compilers differs and adapt where needed.
+\layout Itemize
+
+check the device specific header files
+\begin_inset LatexCommand \index{Header files}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Include files}
+
+\end_inset
+
+ for compiler specific syntax.
+ Eventually include the file <compiler.h
+\begin_inset LatexCommand \index{compiler.h (include file)}
+
+\end_inset
+
+>
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/compiler.h?view=markup}
+
+\end_inset
+
+ to allow using common header files.
+ (see f.e.
+ cc2510fx.h
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/cc2510fx.h?view=markup}
+
+\end_inset
+
+).
+\layout Itemize
+
+check whether the startup code contains the correct initialization (watchdog,
+ peripherals).
+\layout Itemize
+
+check whether the sizes of short, int, long match.
+\layout Itemize
+
+check if some 16 or 32 bit hardware registers require a specific addressing
+ order (least significant or most significant byte first) and adapt if needed
+ (
+\emph on
+first
+\emph default
+ and
+\emph on
+last
+\emph default
+ relate to time and not to lower/upper memory location here, so this is
+
+\emph on
+not
+\emph default
+ the same as endianness).
+\layout Itemize
+
+check whether the keyword
+\emph on
+volatile
+\emph default
+ is used where needed.
+ The compilers might differ in their optimization characteristics (as different
+ versions of the same compiler might also use more clever optimizations
+ this is good idea anyway).
+ See section
+\begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
+
+\end_inset
+
+.
+\layout Itemize
+
+check that the compilers are not told to supress warnings.
+\layout Itemize
+
+check and convert compiler specific extensions (interrupts, memory areas,
+ pragmas etc.).
+\layout Itemize
+
+check for differences in type promotion.
+ Especially check for math operations on
+\family typewriter
+char
+\family default
+ or
+\family typewriter
+unsigned char
+\family default
+ variables.
+ For the sake of C99 compatibility SDCC will probably promote these to
+\family typewriter
+int
+\family default
+ more often than other compilers.
+ Eventually insert explicit casts to
+\family typewriter
+(char)
+\family default
+or
+\family typewriter
+ (unsigned char)
+\family default
+.
+ Also check that the ~\SpecialChar ~
+operator
+\begin_inset LatexCommand \index{\~\/ Operator}
+
+\end_inset
+
+ is not used on
+\family typewriter
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+
+\family default
+ variables, use the !\SpecialChar ~
+operator instead.
+ See sections
+\begin_inset LatexCommand \ref{type promotion}
+
+\end_inset
+
+ and
+\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
+
+\end_inset
+
+.
+\layout Itemize
+
+check the assembly code generated for interrupt routines (f.e.
+ for calls to possibly non-reentrant library functions).
+\layout Itemize
+
+check whether timing loops result in proper timing (or preferably consider
+ a rewrite of the code with timer based delays instead).
+\layout Itemize
+
+check for differences in printf parameters (some compilers push (va_arg
+\begin_inset LatexCommand \index{vararg, va\_arg}
+
+\end_inset
+
+) char variables as
+\family typewriter
+int
+\family default
+ others push them as
+\family typewriter
+char
+\family default
+.
+ See section
+\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
+
+\end_inset
+
+).
+\layout Itemize
+
+check the resulting memory map
+\begin_inset LatexCommand \index{Memory map}
+
+\end_inset
+
+.
+ Usage of different memory spaces: code, stack, data (for mcs51/ds390 additional
+ly idata, pdata, xdata).
+ Eventually check if unexpected library functions are included.
+\layout Section
+
+Tools
+\begin_inset LatexCommand \index{Tools}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align left
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="12" columns="3">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0pt">
+<column alignment="left" valignment="top" leftline="true" width="0pt">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Purpose
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Directory
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+uCsim
+\begin_inset LatexCommand \index{uCsim}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Simulator for various architectures
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/sim/ucsim
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+keil2sdcc.pl
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+header file
+\begin_inset LatexCommand \index{Header files}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Include files}
+
+\end_inset
+
+ conversion
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/support/scripts
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+mh2h.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+header file conversion
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/support/scripts
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+as-gbz80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+as-z80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+asx8051
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SDCDB
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Simulator
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+aslink
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+link-z80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+link-gbz80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+packihx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Intel Hex packer
+\begin_inset LatexCommand \index{packihx (tool)}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
\newline
-;;\SpecialChar ~
-t\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdbsrc-mode\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+
+\layout Section
+
+Documentation
+\begin_inset LatexCommand \index{Documentation}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align left
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="10" columns="2">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="40col%">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="60col%">
+<row topline="true" bottomline="true" endhead="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Subject / Title
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Filename / Where to get
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SDCC Compiler User Guide
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+You're reading it right now
+\emph on
+ \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Toggles Sdcdbsrc mode (turns it off)
-\newline
-;;
+
+\hfill
+online at:
+\emph default
+
\newline
-;;\SpecialChar ~
-C-c\SpecialChar ~
-C-f\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-finish-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Changelog of SDCC
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/Changelog
+\emph on
+ \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB finish command
+
+\hfill
+online at:
+\emph default
+
\newline
-;;
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/ChangeLog}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+ASXXXX
+\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler documentation}
+
+\end_inset
+
+ Assemblers and
\newline
-;;\SpecialChar ~
-C-x\SpecialChar ~
-SPC\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdb-break\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+ASLINK
+\begin_inset LatexCommand \index{aslink}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Linker documentation}
+
+\end_inset
+
+ Relocating Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/as/doc/asxhtm.html
+\emph on
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Set break for line with point
+
+\hfill
+online at:
+\emph default
+
\newline
-;;\SpecialChar ~
-ESC\SpecialChar ~
-t\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-sdcdbsrc-mode\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SDCC regression test
+\begin_inset LatexCommand \index{Regression test}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/doc/test_suite_spec.pdf
+\emph on
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Toggle Sdcdbsrc mode
+
+\hfill
+online at:
+\emph default
+
\newline
-;;\SpecialChar ~
-ESC\SpecialChar ~
-m\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/test_suite_spec.pdf}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Various notes
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/doc/*
+\emph on
\SpecialChar ~
\SpecialChar ~
-sdcdbsrc-srcmode\SpecialChar ~
\SpecialChar ~
+
+\hfill
+online at:
+\emph default
+
+\newline
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/doc/}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Notes on debugging with SDCDB
+\begin_inset LatexCommand \index{SDCDB (debugger)}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/debugger/README
+\emph on
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+
+\hfill
+online at
+\emph default
+:
+\newline
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/debugger/README}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+uCsim
+\begin_inset LatexCommand \index{uCsim}
+
+\end_inset
+
+ Software simulator for microcontrollers
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/sim/ucsim/doc
+\family default
+\series default
+\shape default
+\size default
+\emph default
+\bar default
+\noun default
+/index.html
+\emph on
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+
+\hfill
+online at:
+\emph default
+
+\newline
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/sim/ucsim/doc/index.html}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Temporary notes on the pic16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/src/pic16/NOTES
+\emph on
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+
+\hfill
+online at:
+\newline
+
+\emph default
+
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/src/pic16/NOTES}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SDCC internal documentation (debugging file format)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/doc/
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+cdbfileformat.pd
+\family default
+\series default
+\shape default
+\size default
+\emph default
+\bar default
+\noun default
+f
+\emph on
+ \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Toggle list mode
+
+\hfill
+online at:
+\emph default
+
\newline
-;;
+
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/cdbfileformat.pdf}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
\newline
-\layout Chapter
-\pagebreak_top
-TIPS
+\layout Section
+
+Related open source tools
+\begin_inset LatexCommand \label{sec:Related-open-source-tools}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Related tools}
+
+\end_inset
+
+
\layout Standard
+\align left
-Here are a few guidelines that will help the compiler generate more efficient
- code, some of the tips are specific to this compiler others are generally
- good programming practice.
-\layout Itemize
+\begin_inset Tabular
+<lyxtabular version="3" rows="14" columns="3">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0pt">
+<column alignment="block" valignment="top" leftline="true" width="30line%">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Use the smallest data type to represent your data-value.
- If it is known in advance that the value is going to be less than 256 then
- use an 'unsigned char' instead of a 'short' or 'int'.
- Please note, that ANSI C requires both signed and unsigned chars to be
- promoted to 'signed int'
-\begin_inset LatexCommand \index{promotion to signed int}
+\layout Standard
+
+\series bold
+Name
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- before doing any operation.
- This promotion
-\begin_inset LatexCommand \index{type promotion}
+\layout Standard
+
+
+\series bold
+Purpose
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\series bold
+Where to get
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \label{type promotion}
+gpsim
+\begin_inset LatexCommand \index{gpsim (pic simulator)}
\end_inset
- can be omitted, if the result is the same.
- The effect of the promotion rules together with the sign-extension is often
- surprising:
-\begin_deeper
-\layout Verse
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PIC simulator
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-unsigned char uc = 0xfe;
-\newline
-if (uc * uc < 0) /* this is true! */
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-....
-\newline
-}
\layout Standard
+gputils
+\begin_inset LatexCommand \index{gputils (pic tools)}
-\family typewriter
-uc * uc
-\family default
- is evaluated as
-\family typewriter
-(int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
-\family default
-.
-
-\newline
-Another one:
-\layout Verse
+\end_inset
-\family typewriter
-(unsigned char) -12 / (signed char) -3 = ...
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-No, the result is not 4:
-\layout Verse
+GNU PIC utilities
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-\family typewriter
-(int) (unsigned char) -12 / (int) (signed char) -3 =
-\newline
-(int) (unsigned char) 0xf4 / (int) (signed char) 0xfd =
-\newline
-(int) 0x00f4 / (int) 0xfffd =
-\newline
-(int) 0x00f4 / (int) 0xfffd =
-\newline
-(int) 244 / (int) -3 =
-\newline
-(int) -81 = (int) 0xffaf;
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-Don't complain, that gcc gives you a different result.
- gcc uses 32 bit ints, while SDCC uses 16 bit ints.
- Therefore the results are different.
-\newline
-From
-\begin_inset Quotes sld
+flP5
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-comp.lang.c FAQ
-\begin_inset Quotes srd
+\layout Standard
+
+PIC programmer
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-:
-\layout Quote
+\layout Standard
-If well-defined overflow characteristics are important and negative values
- are not, or if you want to steer clear of sign-extension problems when
- manipulating bits or bytes, use one of the corresponding unsigned types.
- (Beware when mixing signed and unsigned values in expressions, though.)
-\newline
-Although character types (especially unsigned char) can be used as "tiny"
- integers, doing so is sometimes more trouble than it's worth, due to unpredicta
-ble sign extension and increased code size.
-\end_deeper
-\layout Itemize
-Use unsigned when it is known in advance that the value is not going to
- be negative.
- This helps especially if you are doing division or multiplication, bit-shifting
- or are using an array index.
-\layout Itemize
+\begin_inset LatexCommand \url{http://freshmeat.net/projects/flp5/}
-NEVER jump into a LOOP.
-\layout Itemize
+\end_inset
-Declare the variables to be local
-\begin_inset LatexCommand \index{local variables}
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- whenever possible, especially loop control variables (induction).
-\layout Itemize
+\layout Standard
-Since the compiler does not always do implicit integral promotion, the programme
-r should do an explicit cast when integral promotion is required.
-\layout Itemize
+ec2drv/newcdb
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Reducing the size of division, multiplication & modulus operations can reduce
- code size substantially.
- Take the following code for example.
-\begin_deeper
-\layout Verse
+\layout Standard
+Tools for Silicon Laboratories JTAG debug adapter, partly based on SDCDB
+ (Unix only)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-foobar(unsigned int p1, unsigned char ch)
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-unsigned char ch1 = p1 % ch ;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-....
-\newline
-}
\layout Standard
-For the modulus operation the variable ch will be promoted to unsigned int
- first then the modulus operation will be performed (this will lead to a
- call to support routine _moduint()), and the result will be casted to a
- char.
- If the code is changed to
-\layout Verse
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/ec2drv}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-foobar(unsigned int p1, unsigned char ch)
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-unsigned char ch1 = (unsigned char)p1 % ch ;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-....
-\newline
-}
\layout Standard
-It would substantially reduce the code generated (future versions of the
- compiler will be smart enough to detect such optimization opportunities).
-\end_deeper
-\layout Itemize
+indent
+\begin_inset LatexCommand \index{indent (source formatting tool)}
-Have a look at the assembly listing to get a
-\begin_inset Quotes sld
\end_inset
-feeling
-\begin_inset Quotes srd
+
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- for the code generation.
-\layout Section
+\layout Standard
-Porting code from or to other compilers
-\layout Itemize
+Formats C source - Master of the white spaces
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-check whether endianness of the compilers differs and adapt where needed.
-\layout Itemize
+\layout Standard
-check the device specific header files for compiler specific syntax.
- Eventually include the file <compiler.h
-\begin_inset LatexCommand \index{compiler.h (include file)}
+
+\begin_inset LatexCommand \url{http://directory.fsf.org/GNU/indent.html}
\end_inset
-> to allow using common header files.
-\layout Itemize
-check whether the startup code contains the correct initialization (watchdog,
- peripherals).
-\layout Itemize
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-check whether the sizes of short, int, long match.
-\layout Itemize
+\layout Standard
-check if some 16 or 32 bit hardware registers require a specific addressing
- order (least significant or most significant byte first) and adapt if needed
- (
-\emph on
-first
-\emph default
- and
-\emph on
-last
-\emph default
- relate to time and not to lower/upper memory location here, so this is
-
-\emph on
-not
-\emph default
- the same as endianness).
-\layout Itemize
+srecord
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
-check whether the keyword
-\emph on
-volatile
-\emph default
- is used where needed.
- The compilers might differ in their optimization characteristics (as different
- versions of the same compiler might also use more clever optimizations
- this is good idea anyway).
-\layout Itemize
+\end_inset
-check that the compilers are not told to supress warnings.
-\layout Itemize
-check and convert compiler specific extensions (interrupts, memory areas,
- pragmas etc.).
-\layout Itemize
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-check for differences in type promotion (especially check for math operations
- on char variables and for the use of the ~\SpecialChar ~
-operator on bit variables.
- See
-\begin_inset LatexCommand \ref{type promotion}
+\layout Standard
+Object file conversion, checksumming, ...
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
- and
-\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
+
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/srecord}
\end_inset
-).
-\layout Itemize
-check the assembly code generated for interrupt routines (f.e.
- for calls to possibly non-reentrant library functions).
-\layout Itemize
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-check whether timing loops result in proper timing (or preferably consider
- a rewrite of the code with timer based delays instead).
-\layout Itemize
+\layout Standard
-check for differences in printf parameters (some compilers push (va_arg
-\begin_inset LatexCommand \index{va\_arg}
+objdump
+\begin_inset LatexCommand \index{objdump (tool)}
\end_inset
-) char variables as integers others as char).
-\layout Itemize
-check the resulting memory layout.
-\layout Section
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Tools
-\begin_inset LatexCommand \index{Tools}
+\layout Standard
+Object file conversion, ...
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- included in the distribution
\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="12" columns="3">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0pt">
-<column alignment="left" valignment="top" leftline="true" width="0pt">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
+Part of binutils (should be there anyway)
+\end_inset
+</cell>
+</row>
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Name
+cmon51
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Purpose
+8051 monitor (hex up-/download, single step, disassemble)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Directory
+
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/cmon51}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-uCsim
+doxygen
+\begin_inset LatexCommand \index{doxygen (source documentation tool)}
+
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Simulator for various architectures
+Source code documentation system
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/sim/ucsim
+
+\begin_inset LatexCommand \url{http://www.doxygen.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-keil2sdcc.pl
+kdevelop
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-header file conversion
+IDE (has anyone tried integrating SDCC & SDCDB? Unix only)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/support/scripts
+
+\begin_inset LatexCommand \url{http://www.kdevelop.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-mh2h.c
+paulmon
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-header file conversion
+8051 monitor (hex up-/download, single step, disassemble)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/support/scripts
+
+\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/paulmon2.html}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-as-gbz80
+splint
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
+
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Assembler
+Statically checks c sources (see
+\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+
+\end_inset
+
+)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\begin_inset LatexCommand \url{http://www.splint.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-as-z80
+ddd
+\begin_inset LatexCommand \index{DDD (debugger)}
+
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Assembler
+Debugger, serves nicely as GUI to SDCDB
+\begin_inset LatexCommand \index{SDCDB (debugger)}
+
+\end_inset
+
+ (Unix only)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
-<row topline="true">
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\layout Section
+
+Related documentation / recommended reading
+\layout Standard
+\align left
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="7" columns="3">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0pt">
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-asx8051
+
+\series bold
+Name
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Assembler
+
+\series bold
+Subject / Title
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
+\series bold
+Where to get
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
\family roman
\series medium
\shape up
\bar no
\noun off
\color none
-sdcc/bin
+c-refcard.pdf
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+C Reference Card
+\begin_inset LatexCommand \index{C Reference card}
+
+\end_inset
+
+, 2 pages
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\begin_inset LatexCommand \url{http://refcards.com/refcards/c/index.html}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-sdcdb
+c-faq
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Simulator
+C-FAQ
+\begin_inset LatexCommand \index{C FAQ}
+
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\begin_inset LatexCommand \url{http://www.c-faq.com}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-aslink
+ISO/IEC 9899:TC2
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Linker
+
+\begin_inset Quotes sld
+\end_inset
+
+C-Standard
+\begin_inset Quotes srd
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
-\layout Standard
+\layout Standard
+
+
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
+
+\end_inset
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
\end_inset
</cell>
</row>
\layout Standard
-link-z80
+ISO/IEC DTR 18037
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Linker
+
+\begin_inset Quotes sld
+\end_inset
+
+Extensions for Embedded C
+\begin_inset Quotes srd
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1021.pdf}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-link-gbz80
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Linker
+Latest datasheet of target CPU
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+vendor
\end_inset
</cell>
</row>
\layout Standard
-packihx
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-ihx packer
+Revision history of datasheet
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+vendor
\end_inset
</cell>
</row>
\layout Section
-Documentation
-\begin_inset LatexCommand \index{Documentation}
+Application notes specifically for SDCC
+\layout Standard
+
+SDCC makes no claims about the completeness of this list and about up-to-datenes
+s or correctness of the application notes
+\begin_inset LatexCommand \index{Application notes}
\end_inset
- included in the distribution
+.
\layout Standard
-\align center
+\align left
+
+\size footnotesize
\begin_inset Tabular
-<lyxtabular version="3" rows="10" columns="2">
+<lyxtabular version="3" rows="7" columns="3">
<features>
-<column alignment="left" valignment="top" leftline="true" width="0">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<column alignment="block" valignment="top" leftline="true" width="17col%">
+<column alignment="block" valignment="top" leftline="true" width="27col%">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="57col%">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Subject / Title
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-Where to get / filename
+\series bold
+\size footnotesize
+Vendor
\end_inset
</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="left" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC Compiler User Guide
+
+\series bold
+\size footnotesize
+Subject / Title
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-You're reading it right now
+
+\series bold
+\size footnotesize
+Where to get
\end_inset
</cell>
</row>
\layout Standard
-Changelog of SDCC
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-sdcc/Changelog
+\size footnotesize
+Maxim / Dallas
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-ASXXXX
-\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
-\end_inset
+\size footnotesize
+Using the SDCC Compiler for the DS80C400
+\begin_inset LatexCommand \index{DS80C400}
+\end_inset
-\begin_inset LatexCommand \index{Assembler documentation}
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- Assemblers and ASLINK
-\begin_inset LatexCommand \index{aslink}
+\layout Standard
-\end_inset
+\size footnotesize
-\begin_inset LatexCommand \index{Linker documentation}
+\begin_inset LatexCommand \url{http://pdfserv.maxim-ic.com/en/an/AN3346.pdf}
\end_inset
- Relocating Linker
+
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-sdcc/as/doc/asxhtm.html
+
+\size footnotesize
+Maxim / Dallas
\end_inset
</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell multicolumn="1" alignment="left" valignment="top" topline="true" leftline="true" usebox="none" width="30line%">
\begin_inset Text
\layout Standard
-SDCC regression test
-\begin_inset LatexCommand \index{Regression test}
-\end_inset
+\size footnotesize
+Using the Free SDCC C Compiler to Develop Firmware for the DS89C420/430/440/450
+\begin_inset LatexCommand \index{DS89C4x0}
+\end_inset
+ Family of Microcontrollers
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/doc/test_suite_spec.pdf
+
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://pdfserv.maxim-ic.com/en/an/AN3477.pdf}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-Various notes
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-sdcc/doc/*
+\size footnotesize
+Silicon Laboratories / Cygnal
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Notes on debugging with sdcdb
-\begin_inset LatexCommand \index{sdcdb (debugger)}
+
+\size footnotesize
+Integrating SDCC 8051 Tools Into The Silicon Labs IDE
+\begin_inset LatexCommand \index{IDE}
\end_inset
\layout Standard
-sdcc/debugger/README
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\size footnotesize
-Software simulator for microcontrollers
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\begin_inset LatexCommand \url{http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/en/an198.pdf}
-\layout Standard
+\end_inset
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/sim/ucsim/doc
-\family default
-\series default
-\shape default
-\size default
-\emph default
-\bar default
-\noun default
-\color default
-/index.html
\end_inset
</cell>
</row>
\layout Standard
-Temporary notes on the pic16
-\begin_inset LatexCommand \index{PIC16}
-
-\end_inset
-
- port
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-sdcc/src/pic16/NOTES
+\size footnotesize
+Ramtron / Goal Semiconductor
\end_inset
</cell>
-</row>
-<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-SDCC internal documentation (debugging file format)
+
+\size footnotesize
+Interfacing SDCC to Syn and Textpad
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/doc/
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-cdbfileformat.pd
-\family default
-\series default
-\shape default
-\size default
-\emph default
-\bar default
-\noun default
-\color default
-f
-\end_inset
-</cell>
-</row>
-</lyxtabular>
-
-\end_inset
-
-
-\newline
-
-\layout Section
-
-Related open source tools
-\begin_inset LatexCommand \label{sec:Related-open-source-tools}
-
-\end_inset
+\size footnotesize
-\begin_inset LatexCommand \index{Related tools}
+\begin_inset LatexCommand \url{http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp}
\end_inset
-
-
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="14" columns="3">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0pt">
-<column alignment="block" valignment="top" leftline="true" width="30line%">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Name
+
+\size footnotesize
+Ramtron / Goal Semiconductor
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Purpose
+
+\size footnotesize
+Installing and Configuring SDCC and Crimson Editor
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Where to get
+
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-gpsim
-\begin_inset LatexCommand \index{gpsim (pic simulator)}
-
-\end_inset
-
+\size footnotesize
+Texas Instruments
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-PIC simulator
+
+\size footnotesize
+MSC12xx Programming with SDCC
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=sbaa109&fileType=pdf}
\end_inset
\end_inset
</cell>
</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+</lyxtabular>
+
+\end_inset
+
+\layout Section
+
+Some Questions
\layout Standard
-gputils
-\begin_inset LatexCommand \index{gputils (pic tools)}
+Some questions answered, some pointers given - it might be time to in turn
+ ask
+\emph on
+you
+\emph default
+ some questions:
+\layout Itemize
+
+can you solve your project with the selected microcontroller? Would you
+ find out early or rather late that your target is too small/slow/whatever?
+ Can you switch to a slightly better device if it doesn't fit?
+\layout Itemize
+
+should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
+ and/or another programming language be more adequate? Would an operating
+ system on the target device help?
+\layout Itemize
+
+if you solved the problem, will the marketing department be happy?
+\layout Itemize
+
+if the marketing department is happy, will customers be happy?
+\layout Itemize
+
+if you're the project manager, marketing department and maybe even the customer
+ in one person, have you tried to see the project from the outside?
+\layout Itemize
+
+is the project done if you think it is done? Or is just that other interface/pro
+tocol/feature/configuration/option missing? How about website, manual(s),
+ internationali(z|s)ation, packaging, labels, 2nd source for components,
+ electromagnetic compatability/interference, documentation for production,
+ production test software, update mechanism, patent issues?
+\layout Itemize
+is your project adequately positioned in that magic triangle: fame, fortune,
+ fun?
+\layout Standard
+
+Maybe not all answers to these questions are known and some answers may
+ even be
+\emph on
+no
+\emph default
+, nevertheless knowing these questions may help you to avoid burnout
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+burnout is bad for electronic devices, programmers and motorcycle tyres
\end_inset
+.
+ Chances are you didn't want to hear some of them...
+\layout Chapter
+
+Support
+\begin_inset LatexCommand \index{Support}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-GNU PIC utilities
+SDCC has grown to be a large project.
+ The compiler alone (without the preprocessor, assembler and linker) is
+ well over 150,000 lines of code (blank stripped).
+ The open source nature of this project is a key to its continued growth
+ and support.
+ You gain the benefit and support of many active software developers and
+ end users.
+ Is SDCC perfect? No, that's why we need your help.
+ The developers take pride in fixing reported bugs.
+ You can help by reporting the bugs and helping other SDCC users.
+ There are lots of ways to contribute, and we encourage you to take part
+ in making SDCC a great software package.
+
+\layout Standard
+
+The SDCC project is hosted on the SDCC sourceforge site at
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ You'll find the complete set of mailing lists
+\begin_inset LatexCommand \index{Mailing list(s)}
+\end_inset
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
+, forums, bug reporting system, patch submission
+\begin_inset LatexCommand \index{Patch submission}
\end_inset
+ system, download
+\begin_inset LatexCommand \index{download}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ area and Subversion code repository
+\begin_inset LatexCommand \index{Subversion code repository}
-flP5
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ there.
+\layout Section
+
+Reporting Bugs
+\begin_inset LatexCommand \index{Bug reporting}
-PIC programmer
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+
+\begin_inset LatexCommand \index{Reporting bugs}
+
+\end_inset
+
\layout Standard
+The recommended way of reporting bugs is using the infrastructure of the
+ sourceforge site.
+ You can follow the status of bug reports there and have an overview about
+ the known bugs.
+\layout Standard
-\begin_inset LatexCommand \url{http://freshmeat.net/projects/flp5/}
+Bug reports are automatically forwarded to the developer mailing list and
+ will be fixed ASAP.
+ When reporting a bug, it is very useful to include a small test program
+ (the smaller the better) which reproduces the problem.
+ If you can isolate the problem by looking at the generated assembly code,
+ this can be very helpful.
+ Compiling your program with the -
+\begin_inset ERT
+status Collapsed
+\layout Standard
+
+\backslash
+/
\end_inset
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ option can sometimes be useful in locating optimization problems.
+ When reporting a bug please make sure you:
+\layout Enumerate
+
+Attach the code you are compiling with SDCC.
+
+\layout Enumerate
+
+Specify the exact command you use to run SDCC, or attach your Makefile.
+
+\layout Enumerate
+
+Specify the SDCC version (type "
+\family sans
+\series bold
+sdcc -v
+\family default
+\series default
+"), your platform, and operating system.
+
+\layout Enumerate
+
+Provide an exact copy of any error message or incorrect output.
+
+\layout Enumerate
+
+Put something meaningful in the subject of your message.
\layout Standard
-ec2drv/newcdb
+Please attempt to include these 5 important parts, as applicable, in all
+ requests for support or when reporting any problems or bugs with SDCC.
+ Though this will make your message lengthy, it will greatly improve your
+ chance that SDCC users and developers will be able to help you.
+ Some SDCC developers are frustrated by bug reports without code provided
+ that they can use to reproduce and ultimately fix the problem, so please
+ be sure to provide sample code if you are reporting a bug!
+\layout Standard
+
+Please have a short check that you are using a recent version of SDCC and
+ the bug is not yet known.
+ This is the link for reporting bugs:
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ With SDCC on average having more than 200 downloads
+\begin_inset LatexCommand \index{download}
-Tools for Silicon Laboratories JTAG debug adapter, partly based on sdcdb
- (Unix only)
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+ on sourceforge per day
+\begin_inset Foot
+collapsed false
\layout Standard
+220 daily downloads on average Jan-Sept 2006 and about 150 daily downloads
+ between 2002 and 2005.
+ This does not include other methods of distribution.
+\end_inset
+
+ there must be some users.
+ So it's not exactly easy to find a new bug.
+ If you find one we need it:
+\emph on
+reporting bugs is good
+\emph default
+.
+\layout Section
+
+Requesting Features
+\begin_inset LatexCommand \label{sub:Requesting-Features}
+
+\end_inset
+
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/ec2drv}
+\begin_inset LatexCommand \index{Feature request}
\end_inset
+\begin_inset LatexCommand \index{Requesting features}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-indent
-\begin_inset LatexCommand \index{indent (source formatting tool)}
+Like bug reports feature requests are forwarded to the developer mailing
+ list.
+ This is the link for requesting features:
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
\end_inset
+.
+\layout Section
+
+Submitting patches
+\layout Standard
+
+Like bug reports contributed patches are forwarded to the developer mailing
+ list.
+ This is the link for submitting patches
+\begin_inset LatexCommand \index{Patch submission}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+:
+\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
-Formats C source - Master of the white spaces
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
+You need to specify some parameters to the
+\family typewriter
+diff
+\family default
+ command for the patches to be useful.
+ If you modified more than one file a patch created f.e.
+ with
+\family sans
+\series bold
-\begin_inset LatexCommand \url{http://directory.fsf.org/GNU/indent.html}
-
+\begin_inset Quotes sld
\end_inset
-
+diff -Naur unmodified_directory modified_directory >my_changes.patch
+\begin_inset Quotes srd
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-srecord
-\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
+\family default
+\series default
+ will be fine, otherwise
+\family sans
+\series bold
+\begin_inset Quotes sld
\end_inset
-
+diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
+\begin_inset Quotes srd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-Object file conversion, checksumming, ...
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\series default
+
+\family default
+will do.
+\layout Section
+Getting Help
\layout Standard
-
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/srecord}
+These links should take you directly to the
+\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
\end_inset
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_inset Foot
+collapsed false
\layout Standard
-objdump
-\begin_inset LatexCommand \index{objdump (tool)}
+Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
+ automated messages (mid 2003)
+\end_inset
+
+ and the
+\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
\end_inset
+, lists
+\begin_inset LatexCommand \index{Mailing list(s)}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ and forums are archived and searchable so if you are lucky someone already
+ had a similar problem.
+ While mails to the lists themselves are delivered promptly their web front
+ end on sourceforge sometimes shows a severe time lag (up to several weeks),
+ if you're seriously using SDCC please consider subscribing to the lists.
+\layout Section
+
+ChangeLog
\layout Standard
-Object file conversion, ...
+You can follow the status of the Subversion version
+\begin_inset LatexCommand \index{version}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ of SDCC by watching the Changelog
+\begin_inset LatexCommand \index{Changelog}
-Part of binutils (should be there anyway)
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ in the Subversion repository
+\size footnotesize
+
+\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
-cmon51
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+.
+\layout Section
+
+Subversion Source Code Repository
\layout Standard
-8051 monitor (hex up-/download, single step, disassemble)
+The output of
+\family sans
+\series bold
+sdcc --version
+\family default
+\series default
+ or the filenames of the snapshot versions of SDCC include date and its
+ Subversion
+\begin_inset LatexCommand \index{Subversion code repository}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ number.
+ Subversion allows to download the source of recent or previous versions
+
+\begin_inset LatexCommand \url{http://sourceforge.net/svn/?group_id=599}
+\end_inset
-\begin_inset LatexCommand \url{http://sourceforge.net/projects/cmon51}
+ (by number or by date).
+ An on-line source code browser and detailled instructions are also available
+ there.
+ SDCC versions starting from 1999 up to now are available (currently the
+ versions prior to the conversion from cvs
+\begin_inset LatexCommand \index{cvs|see{Subversion}}
\end_inset
+ to Subversion (April 2006) are either by accessible by Subversion or by
+ cvs).
+\layout Section
+
+Release policy
+\begin_inset LatexCommand \index{Release policy}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-doxygen
-\begin_inset LatexCommand \index{doxygen (source documentation tool)}
+Historically there often were long delays between official releases and
+ the sourceforge download area tends to get not updated at all.
+ Excuses in the past might have referred to problems with live range analysis,
+ but as this was fixed a while ago, the current problem is that another
+ excuse has to be found.
+ Kidding aside, we have to get better there! On the other hand there are
+ daily snapshots available at
+\begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
\end_inset
+, and you can always build the very last version (hopefully with many bugs
+ fixed, and features added) from the source code available at
+\begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ A release wiki
+\begin_inset LatexCommand \index{wiki}
-Source code documentation system
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\begin_inset LatexCommand \index{Release wiki}
-\begin_inset LatexCommand \url{http://www.doxygen.org}
+\end_inset
+
+ at
+\begin_inset LatexCommand \url{http://sdcc.sf.net/release_wiki/}
\end_inset
+ also holds some information about past and future releases.
+\layout Section
+
+Examples
+\begin_inset LatexCommand \index{Examples}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-kdevelop
+You'll find some small examples in the directory
+\emph on
+sdcc/device/examples/.
+
+\emph default
+More examples and libraries are available at
+\emph on
+ The SDCC Open Knowledge Resource
+\begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+
+\emph default
+web site or at
+\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
-IDE (has anyone tried integrating SDCC & sdcdb? Unix only)
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
-\begin_inset LatexCommand \url{http://www.kdevelop.org}
+\begin_inset Note
+collapsed true
+
+\layout Standard
+
+I did insert a reference to Paul's web site here although it seems rather
+ dedicated to a specific 8032 board (I think it's okay because it f.e.
+ shows LCD/Harddisc interface and has a free 8051 monitor.
+ Independent 8032 board vendors face hard competition of heavily subsidized
+ development boards anyway).
+\layout Standard
+Maybe we should include some links to real world applications.
+ Preferably pointer to pointers (one for each architecture) so this stays
+ manageable here?
\end_inset
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Section
-\layout Standard
+Quality control
+\begin_inset LatexCommand \label{sec:Quality-control}
-paulmon
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-8051 monitor (hex up-/download, single step, disassemble)
+\begin_inset LatexCommand \index{Quality control}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
+The compiler is passed through nightly compile and build checks.
+ The so called
+\shape italic
+regression tests
+\shape default
-\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/paulmon2.html}
+\begin_inset LatexCommand \index{Regression test}
\end_inset
+ check that SDCC itself compiles flawlessly on several host platforms (i386,
+ Opteron, 64 bit Alpha, ppc64, MacOS X on PPC, Solaris on Sparc) and checks
+ the quality of the code generated by SDCC by running the code for several
+ target platforms through simulators.
+ The regression test suite comprises more than 100 files which expand to
+ more than 500 test cases which include more than 4500 tests.
+ The results of these tests are published daily on SDCC's snapshot page
+ (click on the red or green symbols on the right side of
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+).
\layout Standard
-splint
-\begin_inset LatexCommand \index{splint (syntax checking tool)}
+There is a separate document
+\shape italic
+test_suite.pdf
+\begin_inset LatexCommand \index{Test suite}
\end_inset
+\shape default
+
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/test_suite_spec.pdf}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+ about the regression test suite.
\layout Standard
-Statically checks c sources (see
-\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+You'll find the test code in the directory
+\shape italic
+sdcc/support/regression
+\shape default
+.
+ You can run these tests manually by running
+\family sans
+make
+\family default
+ in this directory (or f.e.
+
+\family sans
+\series bold
+\begin_inset Quotes sld
\end_inset
-)
+make test-mcs51
+\begin_inset Quotes srd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-\begin_inset LatexCommand \url{http://www.splint.org}
+\family default
+\series default
+ if you don't want to run the complete tests).
+ The test code might also be interesting if you want to look for examples
+\begin_inset LatexCommand \index{Examples}
\end_inset
+ checking corner cases of SDCC or if you plan to submit patches
+\begin_inset LatexCommand \index{Patch submission}
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
-ddd
-\begin_inset LatexCommand \index{ddd (debugger)}
+The 14bit pic port uses a different set of regression tests
+\begin_inset LatexCommand \index{Regression test (PIC14)}
\end_inset
+, you'll find them in the directory
+\shape italic
+sdcc/src/regression
+\shape default
+.
+\layout Section
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
+Use of SDCC in Education
\layout Standard
-Debugger, serves nicely as GUI to sdcdb
-\begin_inset LatexCommand \index{sdcdb (debugger)}
+In short:
+\emph on
+highly
+\emph default
+ encouraged
+\begin_inset Foot
+collapsed false
-\end_inset
+\layout Standard
- (Unix only)
+the phrase "use in education" might evoke the association "
+\emph on
+only
+\emph default
+ fit for use in education".
+ This connotation is not intended but nevertheless risked as the licensing
+ of SDCC makes it difficult to offer educational discounts
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ If your rationales are to:
+\layout Enumerate
+give students a chance to understand the
+\emph on
+complete
+\emph default
+ steps of code generation
+\layout Enumerate
-\begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
+have a curriculum that can be extended for years.
+ Then you could use an fpga board as target and your curriculum will seamlessly
+ extend from logic synthesis (
+\begin_inset LatexCommand \url[http://www.opencores.org]{opencores.org}
\end_inset
+,
+\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
\end_inset
-</cell>
-</row>
-</lyxtabular>
-
-\end_inset
-
-
-\newline
-\layout Section
+), over assembly programming, to C to FPGA compilers (
+\begin_inset LatexCommand \url[FPGAC]{http://sf.net/projects/fpgac}
-Related documentation / recommended reading
-\layout Standard
-\align center
+\end_inset
-\begin_inset Tabular
-<lyxtabular version="3" rows="8" columns="3">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0pt">
-<column alignment="block" valignment="top" leftline="true" width="30line%">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+) and to C.
+\layout Enumerate
-\layout Standard
+be able to insert excursions about skills like using a revision control
+ system, submitting/applying patches, using a type-setting (as opposed to
+ word-processing) engine LyX/LaTeX, using
+\begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
-Name
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, following some
+\begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
-Subject / Title
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open
+ Source Software, CPU simulation, compiler regression tests
+\begin_inset LatexCommand \index{Regression test}
-Where to get
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+.
+
+\newline
+And if there should be a shortage of ideas then you can always point students
+ to the ever-growing feature request list
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-c-refcard.pdf
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Enumerate
-C Reference Card
-\begin_inset LatexCommand \index{C Reference card}
+not tie students to a specific host platform and instead allow them to use
+ a host platform of
+\emph on
+their
+\emph default
+ choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
+ eventually
+\begin_inset LatexCommand \url[OLPC]{http://www.laptop.org}
\end_inset
-, 2 pages
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+)
+\layout Enumerate
-\layout Standard
+not encourage students to use illegal copies of educational software
+\layout Enumerate
+be immune to licensing/availability/price changes of the chosen tool chain
+\layout Enumerate
-\begin_inset LatexCommand \url{http://refcards.com/refcards/c/index.html}
+be able to change to a new target platform without having to adopt a new
+ tool chain
+\layout Enumerate
-\end_inset
+have complete control over and insight into the tool chain
+\layout Enumerate
+make your students aware about the pros and cons of open source software
+ development
+\layout Enumerate
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+give back to the public as you are probably at least partially publically
+ funded
+\layout Enumerate
+give students a chance to publically prove their skills and to possibly
+ see a world wide impact
\layout Standard
+\pagebreak_bottom
+then SDCC is probably among the first choices.
+ Well, probably SDCC might be the only choice.
+\layout Chapter
-c-faq
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+SDCC Technical Data
+\layout Section
-\layout Standard
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
-C-FAQ-list
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
+SDCC performs a host of standard optimizations in addition to some MCU specific
+ optimizations.
+
+\layout Subsection
-\begin_inset LatexCommand \url{http://www.eskimo.com/~scs/C-faq/top.html}
+Sub-expression Elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
\end_inset
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\layout Standard
-ISO/IEC 9899:TC2
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+The compiler does local and
+\emph on
+g
+\emph default
+lobal
+\emph on
+c
+\emph default
+ommon
+\emph on
+s
+\emph default
+ubexpression
+\emph on
+e
+\emph default
+limination, e.g.:
+\layout Verse
+
+\family typewriter
+i = x + y + 1;
+\newline
+j = x + y;
\layout Standard
+will be translated to
+\layout Verse
-\begin_inset Quotes sld
-\end_inset
-C-Standard
-\begin_inset Quotes srd
-\end_inset
+\family typewriter
+iTemp = x + y;
+\newline
+i = iTemp + 1;
+\newline
+j = iTemp;
+\layout Standard
+Some subexpressions are not as obvious as the above example, e.g.:
+\layout Verse
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+a->b[i].c = 10;
+\newline
+a->b[i].d = 11;
\layout Standard
+In this case the address arithmetic a->b[i] will be computed only once;
+ the equivalent code in C would be.
+\layout Verse
-\size footnotesize
-\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
+\family typewriter
+iTemp = a->b[i];
+\newline
+iTemp.c = 10;
+\newline
+iTemp.d = 11;
+\layout Standard
-\end_inset
+The compiler will try to keep these temporary variables in registers.
+\layout Subsection
+Dead-Code Elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-ISO/IEC DTR 18037
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Verse
+
+\family typewriter
+int global;
+\newline
+
+\newline
+void f () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 1; \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* dead store */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 1;\SpecialChar ~
+/* dead store */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 3;\SpecialChar ~
+/* unreachable */
+\newline
+}
\layout Standard
+will be changed to
+\layout Verse
+
-\begin_inset Quotes sld
-\end_inset
+\family typewriter
+int global;
+\newline
-Extensions for Embedded C
-\begin_inset Quotes srd
-\end_inset
+\newline
+void f () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 2;
+\newline
+}
+\layout Subsection
+Copy-Propagation
+\begin_inset LatexCommand \index{Copy propagation}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+\layout Verse
+
+
+\family typewriter
+int f() {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i, j;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+j = i;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return j;
+\newline
+}
\layout Standard
+will be changed to
+\layout Verse
-\size footnotesize
-\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1021.pdf}
+\family typewriter
+int f() {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i, j;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+j = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return 10;
+\newline
+}
+\layout Standard
-\end_inset
+Note: the dead stores created by this copy propagation will be eliminated
+ by dead-code elimination.
+\layout Subsection
+Loop Optimizations
+\begin_inset LatexCommand \index{Loop optimization}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+
+\begin_inset LatexCommand \label{sub:Loop-Optimizations}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-Latest datasheet of the target CPU
+Two types of loop optimizations are done by SDCC
+\emph on
+loop invariant
+\emph default
+ lifting and
+\emph on
+ strength reduction
+\emph default
+ of loop induction variables.
+ In addition to the strength reduction the optimizer marks the induction
+ variables and the register allocator tries to keep the induction variables
+ in registers for the duration of the loop.
+ Because of this preference of the register allocator
+\begin_inset LatexCommand \index{Register allocation}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, loop induction optimization causes an increase in register pressure, which
+ may cause unwanted spilling of other temporary variables into the stack
+\begin_inset LatexCommand \index{stack}
-vendor
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+ / data space.
+ The compiler will generate a warning message when it is forced to allocate
+ extra space either on the stack or data space.
+ If this extra space allocation is undesirable then induction optimization
+ can be eliminated either for the entire source file (with -
+\begin_inset ERT
+status Collapsed
\layout Standard
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-noinduction option) or for a given function only using #pragma\SpecialChar ~
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
-Revision history of datasheet
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\newline
+
+\newline
+Loop Invariant:
+\layout Verse
-vendor
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+for (i = 0 ; i < 100 ; i ++)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+f += k + l;
\layout Standard
-S.
- S.
- Muchnick
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+changed to
+\layout Verse
+
+\family typewriter
+itemp = k + l;
+\newline
+for (i = 0; i < 100; i++)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+f += itemp;
\layout Standard
-Advanced Compiler Design and Implementation
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+As mentioned previously some loop invariants are not as apparent, all static
+ address computations are also moved out of the loop.
+\newline
-\layout Standard
+\newline
+Strength Reduction
+\begin_inset LatexCommand \index{Strength reduction}
-bookstore (very dedicated, probably read other books first)
\end_inset
-</cell>
-</row>
-</lyxtabular>
-\end_inset
+, this optimization substitutes an expression by a cheaper expression:
+\layout Verse
+\family typewriter
+for (i=0;i < 100; i++)
\newline
-
-\layout Section
-
-Some Questions
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ar[i*5] = i*3;
\layout Standard
-Some questions answered, some pointers given - it might be time to in turn
- ask
-\emph on
-you
-\emph default
- some questions:
-\layout Itemize
+changed to
+\layout Verse
-can you solve your project with the selected microcontroller? Would you
- find out early or rather late that your target is too small/slow/whatever?
- Can you switch to a slightly better device if it doesn't fit?
-\layout Itemize
-should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
- and/or another programming language be more adequate? Would an operating
- system on the target device help?
-\layout Itemize
+\family typewriter
+itemp1 = 0;
+\newline
+itemp2 = 0;
+\newline
+for (i=0;i< 100;i++) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ar[itemp1] = itemp2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+itemp1 += 5;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+itemp2 += 3;
+\newline
+}
+\layout Standard
-if you solved the problem, will the marketing department be happy?
-\layout Itemize
+The more expensive multiplication
+\begin_inset LatexCommand \index{Multiplication}
-if the marketing department is happy, will customers be happy?
-\layout Itemize
+\end_inset
-if you're the project manager, marketing department and maybe even the customer
- in one person, have you tried to see the project from the outside?
-\layout Itemize
+ is changed to a less expensive addition.
+\layout Subsection
-is the project done if you think it is done? Or is just that other interface/pro
-tocol/feature/configuration/option missing? How about website, manual(s),
- internationali(z|s)ation, packaging, labels, 2nd source for components,
- electromagnetic compatability/interference, documentation for production,
- production test software, update mechanism, patent issues?
-\layout Itemize
+Loop Reversing
+\begin_inset LatexCommand \index{Loop reversing}
-is your project adequately positioned in that magic triangle: fame, fortune,
- fun?
-\layout Standard
+\end_inset
-Maybe not all answers to these questions are known and some answers may
- even be
-\emph on
-no
-\emph default
-, nevertheless knowing these questions may help you to avoid burnout
-\begin_inset Foot
-collapsed false
\layout Standard
-burnout is bad for electronic devices, programmers and motorcycle tyres
+This optimization is done to reduce the overhead of checking loop boundaries
+ for every iteration.
+ Some simple loops can be reversed and implemented using a
+\begin_inset Quotes eld
\end_inset
-.
- Chances are you didn't want to hear some of them...
-\layout Chapter
+decrement and jump if not zero
+\begin_inset Quotes erd
+\end_inset
-Support
-\begin_inset LatexCommand \index{Support}
+ instruction.
+ SDCC checks for the following criterion to determine if a loop is reversible
+ (note: more sophisticated compilers use data-dependency analysis to make
+ this determination, SDCC uses a more simple minded analysis).
+\layout Itemize
-\end_inset
+The 'for' loop is of the form
+\newline
+\newline
-\layout Standard
+\family typewriter
+for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
+ += 1])
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+<for body>
+\layout Itemize
-SDCC has grown to be a large project.
- The compiler alone (without the preprocessor, assembler and linker) is
- well over 100,000 lines of code (blank stripped).
- The open source nature of this project is a key to its continued growth
- and support.
- You gain the benefit and support of many active software developers and
- end users.
- Is SDCC perfect? No, that's why we need your help.
- The developers take pride in fixing reported bugs.
- You can help by reporting the bugs and helping other SDCC users.
- There are lots of ways to contribute, and we encourage you to take part
- in making SDCC a great software package.
-
-\layout Standard
+The <for body> does not contain
+\begin_inset Quotes eld
+\end_inset
-The SDCC project is hosted on the SDCC sourceforge site at
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
+continue
+\begin_inset Quotes erd
+\end_inset
+ or 'break
+\begin_inset Quotes erd
\end_inset
.
- You'll find the complete set of mailing lists
-\begin_inset LatexCommand \index{Mailing list(s)}
+\layout Itemize
-\end_inset
+All goto's are contained within the loop.
+\layout Itemize
-, forums, bug reporting system, patch submission
-\begin_inset LatexCommand \index{Patch submission}
+No function calls within the loop.
+\layout Itemize
-\end_inset
+The loop control variable <sym> is not assigned any value within the loop
+\layout Itemize
+
+The loop control variable does NOT participate in any arithmetic operation
+ within the loop.
+\layout Itemize
+
+There are NO switch statements in the loop.
+\layout Subsection
+
+Algebraic Simplifications
+\layout Standard
+
+SDCC does numerous algebraic simplifications, the following is a small sub-set
+ of these optimizations.
+\layout Verse
- system, download
-\begin_inset LatexCommand \index{download}
-\end_inset
+\family typewriter
+i = j + 0;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = j;
+\newline
+i /= 2;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i >>= 1;
+\newline
+i = j - j;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = 0;
+\newline
+i = j / 1;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = j;
+\layout Standard
- area and Subversion code repository
-\begin_inset LatexCommand \index{Subversion code repository}
+Note the subexpressions
+\begin_inset LatexCommand \index{Subexpression}
\end_inset
- there.
-\layout Section
+ given above are generally introduced by macro expansions or as a result
+ of copy/constant propagation.
+\layout Subsection
-Reporting Bugs
-\begin_inset LatexCommand \index{Bug reporting}
+'switch' Statements
+\begin_inset LatexCommand \label{sub:'switch'-Statements}
\end_inset
-\begin_inset LatexCommand \index{Reporting bugs}
+\begin_inset LatexCommand \index{switch statement}
\end_inset
\layout Standard
-The recommended way of reporting bugs is using the infrastructure of the
- sourceforge site.
- You can follow the status of bug reports there and have an overview about
- the known bugs.
-\layout Standard
-
-Bug reports are automatically forwarded to the developer mailing list and
- will be fixed ASAP.
- When reporting a bug, it is very useful to include a small test program
- (the smaller the better) which reproduces the problem.
- If you can isolate the problem by looking at the generated assembly code,
- this can be very helpful.
- Compiling your program with the -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
+SDCC can optimize switch statements to jump tables
+\begin_inset LatexCommand \index{jump tables}
-\backslash
-/
\end_inset
--dumpall
-\begin_inset LatexCommand \index{-\/-dumpall}
+.
+ It makes the decision based on an estimate of the generated code size.
+ SDCC is quite liberal in the requirements for jump table generation:
+\layout Itemize
-\end_inset
+The labels need not be in order, and the starting number need not be one
+ or zero, the case labels are in numerical sequence or not too many case
+ labels are missing.
+\begin_deeper
+\layout Verse
- option can sometimes be useful in locating optimization problems.
- When reporting a bug please maker sure you:
-\layout Enumerate
-Attach the code you are compiling with SDCC.
+\family typewriter
+switch(i) {\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 0: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...
-\layout Enumerate
-
-Specify the exact command you use to run SDCC, or attach your Makefile.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 8: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...
-\layout Enumerate
-
-Specify the SDCC version (type "
-\family sans
-\series bold
-sdcc -v
-\family default
-\series default
-"), your platform, and operating system.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 9: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
-\layout Enumerate
-
-Provide an exact copy of any error message or incorrect output.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 10: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
-\layout Enumerate
-
-Put something meaningful in the subject of your message.
-\layout Standard
-
-Please attempt to include these 5 important parts, as applicable, in all
- requests for support or when reporting any problems or bugs with SDCC.
- Though this will make your message lengthy, it will greatly improve your
- chance that SDCC users and developers will be able to help you.
- Some SDCC developers are frustrated by bug reports without code provided
- that they can use to reproduce and ultimately fix the problem, so please
- be sure to provide sample code if you are reporting a bug!
-\layout Standard
-
-Please have a short check that you are using a recent version of SDCC and
- the bug is not yet known.
- This is the link for reporting bugs:
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
-
-\end_inset
-
-.
-\layout Section
-
-Requesting Features
-\begin_inset LatexCommand \label{sub:Requesting-Features}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Feature request}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Requesting features}
-
-\end_inset
-
-
-\layout Standard
-
-Like bug reports feature requests are forwarded to the developer mailing
- list.
- This is the link for requesting features:
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
-
-\end_inset
-
-.
-\layout Section
-
-Submitting patches
-\layout Standard
-
-Like bug reports contributed patches are forwarded to the developer mailing
- list.
- This is the link for submitting patches
-\begin_inset LatexCommand \index{Patch submission}
-
-\end_inset
-
-:
-\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
-
-\end_inset
-
-.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 11: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 8: ...
+
+\newline
+}\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+}
\layout Standard
-You need to specify some parameters to the
-\family typewriter
-diff
-\family default
- command for the patches to be useful.
- If you modified more than one file a patch created f.e.
- with
-\family sans
-\series bold
-
-\begin_inset Quotes sld
-\end_inset
-
-diff -Naur unmodified_directory modified_directory >my_changes.patch
-\begin_inset Quotes srd
-\end_inset
-
-
-\family default
-\series default
- will be fine, otherwise
-\family sans
-\series bold
-
-\begin_inset Quotes sld
-\end_inset
-
-diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
-\begin_inset Quotes srd
-\end_inset
+Both the above switch statements will be implemented using a jump-table.
+ The example to the right side is slightly more efficient as the check for
+ the lower boundary of the jump-table is not needed.
+\end_deeper
+\layout Itemize
+The number of case labels is not larger than supported by the target architectur
+e.
+\layout Itemize
-\series default
+If the case labels are not in numerical sequence ('gaps' between cases)
+ SDCC checks whether a jump table with additionally inserted dummy cases
+ is still attractive.
-\family default
-will do.
-\layout Section
+\layout Itemize
-Getting Help
+If the starting number is not zero and a check for the lower boundary of
+ the jump-table can thus be eliminated SDCC might insert dummy cases 0,
+ ...
+ .
\layout Standard
-These links should take you directly to the
-\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
-
-\end_inset
-
+Switch statements which have large gaps in the numeric sequence or those
+ that have too many case labels can be split into more than one switch statement
+ for efficient code generation, e.g.:
+\layout Verse
-\begin_inset Foot
-collapsed false
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 2: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 101: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 102: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 103: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 104: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 105: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 106: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 107: ...
+
+\newline
+}
\layout Standard
-Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
- automated messages (mid 2003)
-\end_inset
-
- and the
-\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
-
-\end_inset
-
-, lists
-\begin_inset LatexCommand \index{Mailing list(s)}
-
-\end_inset
+If the above switch statement is broken down into two switch statements
+\layout Verse
- and forums are archived and searchable so if you are lucky someone already
- had a similar problem.
- While mails to the lists themselves are delivered promptly their web front
- end on sourceforge sometimes shows a severe time lag (up to several weeks),
- if you're seriously using SDCC please consider subscribing to the lists.
-\layout Section
-ChangeLog
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 2: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
+
+\newline
+}
\layout Standard
-You can follow the status of the Subversion version
-\begin_inset LatexCommand \index{version}
-
-\end_inset
-
- of SDCC by watching the Changelog
-\begin_inset LatexCommand \index{Changelog}
+and
+\layout Verse
-\end_inset
- in the Subversion repository
-\size footnotesize
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 101: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 102: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 103: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 104: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 105: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 106: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 107: ...
-\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
-
-\end_inset
-
-.
-\layout Section
-
-Subversion Source Code Repository
+\newline
+}
\layout Standard
-The output of
-\family sans
-\series bold
-sdcc --version
-\family default
-\series default
- or the filenames of the snapshot versions of SDCC include date and its
- Subversion
-\begin_inset LatexCommand \index{Subversion}
-
-\end_inset
-
- number.
- Subversion allows to download the source of recent or previous versions
-
-\begin_inset LatexCommand \url{http://sourceforge.net/svn/?group_id=599}
-
-\end_inset
-
- (by number or by date).
- An on-line source code browser and detailled instructions are also available
- there.
- SDCC versions starting from 1999 up to now are available (currently the
- versions prior to the conversion from cvs to Subversion (April 2006) are
- either by accessible by Subversion or by cvs).
-\layout Section
-
-Release policy
-\begin_inset LatexCommand \index{Release policy}
+then both the switch statements will be implemented using jump-tables whereas
+ the unmodified switch statement will not be.
+\layout Standard
-\end_inset
+\begin_inset Note
+collapsed true
\layout Standard
-Historically there often were long delays between official releases and
- the sourceforge download area tends to get not updated at all.
- Excuses in the past might have referred to problems with live range analysis,
- but as this was fixed a while ago, the current problem is that another
- excuse has to be found.
- Kidding aside, we have to get better there! On the other hand there are
- daily snapshots available at
-\begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
-
+There might be reasons which SDCC cannot know about to either favour or
+ not favour jump tables.
+ If the target system has to be as quick for the last switch case as for
+ the first (pro jump table), or if the switch argument is known to be zero
+ in the majority of the cases (contra jump table).
\end_inset
-, and you can always build the very last version (hopefully with many bugs
- fixed, and features added) from the source code available at
-\begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
-
-\end_inset
-.
-\layout Section
+\layout Standard
-Examples
-\begin_inset LatexCommand \index{Examples}
+The pragma nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
\end_inset
-
-\layout Standard
-
-You'll find some small examples in the directory
+ can be used to turn off checking the
\emph on
-sdcc/device/examples/.
-
+j
\emph default
-More examples and libraries are available at
+ump
\emph on
- The SDCC Open Knowledge Resource
-\begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
-
-\end_inset
-
-
+t
\emph default
-web site or at
-\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
+able
+\emph on
+bound
+\emph default
+aries.
+ It has no effect if a default label is supplied.
+ Use of this pragma is dangerous: if the switch
+\begin_inset LatexCommand \index{switch statement}
\end_inset
-.
-\layout Comment
-
-I did insert a reference to Paul's web site here although it seems rather
- dedicated to a specific 8032 board (I think it's okay because it f.e.
- shows LCD/Harddisc interface and has a free 8051 monitor.
- Independent 8032 board vendors face hard competition of heavily subsidized
- development boards anyway).
-\layout Comment
-
-Maybe we should include some links to real world applications.
- Preferably pointer to pointers (one for each architecture) so this stays
- manageable here?
-\layout Section
+ argument is not matched by a case statement the processor will happily
+ jump into Nirvana.
+\layout Subsection
-Quality control
-\begin_inset LatexCommand \index{Quality control}
+Bit-shifting Operations
+\begin_inset LatexCommand \index{Bit shifting}
\end_inset
-
+.
\layout Standard
-The compiler is passed through nightly compile and build checks.
- The so called
-\shape italic
-regression tests
-\shape default
-
-\begin_inset LatexCommand \index{Regression test}
-
-\end_inset
-
- check that SDCC itself compiles flawlessly on several platforms and checks
- the quality of the code generated by SDCC by running the code through simulator
-s.
- There is a separate document
-\shape italic
-test_suite.pdf
-\begin_inset LatexCommand \index{Test suite}
-
-\end_inset
-
+Bit shifting is one of the most frequently used operation in embedded programmin
+g.
+ SDCC tries to implement bit-shift operations in the most efficient way
+ possible, e.g.:
+\layout Verse
-\shape default
- about this.
-\layout Standard
-You'll find the test code in the directory
-\shape italic
-sdcc/support/regression
-\shape default
-.
- You can run these tests manually by running
-\family sans
-make
-\family default
- in this directory (or f.e.
+\family typewriter
+unsigned char i;
+\newline
+...
-\family sans
-\series bold
-
-\begin_inset Quotes sld
-\end_inset
-
-make test-mcs51
-\begin_inset Quotes srd
-\end_inset
-
-
-\family default
-\series default
- if you don't want to run the complete tests).
- The test code might also be interesting if you want to look for examples
-\begin_inset LatexCommand \index{Examples}
-
-\end_inset
+\newline
+i >>= 4;
+\newline
+...
+\layout Standard
- checking corner cases of SDCC or if you plan to submit patches
-\begin_inset LatexCommand \index{Patch submission}
+generates the following code:
+\layout Verse
-\end_inset
-.
+\family typewriter
+mov\SpecialChar ~
+ a,_i
+\newline
+swap a
+\newline
+anl\SpecialChar ~
+ a,#0x0f
+\newline
+mov\SpecialChar ~
+ _i,a
\layout Standard
-The pic port uses a different set of regression tests, you'll find them
- in the directory
-\shape italic
-sdcc/src/regression
-\shape default
-.
-\layout Section
-
-Use of SDCC in Education
-\layout Standard
+In general SDCC will never setup a loop if the shift count is known.
+ Another example:
+\layout Verse
-In short:
-\emph on
-highly
-\emph default
- encouraged
-\begin_inset Foot
-collapsed false
+\family typewriter
+unsigned int i;
+\newline
+...
+
+\newline
+i >>= 9;
+\newline
+...
\layout Standard
-the phrase "use in education" might evoke the association "
-\emph on
-only
-\emph default
- fit for use in education".
- This connotation is not intended but nevertheless risked as the licensing
- of SDCC makes it difficult to offer educational discounts
-\end_inset
+will generate:
+\layout Verse
-.
- If your rationales are to:
-\layout Enumerate
-give students a chance to understand the
-\emph on
-complete
-\emph default
- steps of code generation
-\layout Enumerate
+\family typewriter
+mov\SpecialChar ~
+\SpecialChar ~
+a,(_i + 1)
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+(_i + 1),#0x00
+\newline
+clr\SpecialChar ~
+\SpecialChar ~
+c
+\newline
+rrc\SpecialChar ~
+\SpecialChar ~
+a
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+_i,a
+\layout Subsection
-have a curriculum that can be extended for years.
- Then you could use an fpga board as target and your curriculum will seamlessly
- extend from logic synthesis (
-\begin_inset LatexCommand \url[http://www.opencores.org]{opencores.org}
+Bit-rotation
+\begin_inset LatexCommand \index{Bit rotation}
\end_inset
-,
-\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
-\end_inset
+\layout Standard
-), over assembly programming, to C to FPGA compilers (
-\begin_inset LatexCommand \url[FPGAC]{http://sf.net/projects/fpgac}
+A special case of the bit-shift operation is bit rotation
+\begin_inset LatexCommand \index{rotating bits}
\end_inset
-) and to C.
-\layout Enumerate
+, SDCC recognizes the following expression to be a left bit-rotation:
+\layout Verse
-be able to insert excursions about skills like using a revision control
- system, submitting/applying patches, using a type-setting (as opposed to
- word-processing) engine LyX/LaTeX, using
-\begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
-\end_inset
+\family typewriter
+\series bold
+unsigned
+\series default
+\SpecialChar ~
+\SpecialChar ~
+char i;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* unsigned is needed for rotation */
+\newline
+...
+
+\newline
+i = ((i << 1) | (i >> 7));
+\family default
-, following some
-\begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
+\newline
-\end_inset
+\family typewriter
+...
+\layout Standard
-, understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open
- Source Software, CPU simulation, compiler regression tests
-\begin_inset LatexCommand \index{Regression test}
+will generate the following code:
+\layout Verse
-\end_inset
-.
-
+\family typewriter
+mov\SpecialChar ~
+\SpecialChar ~
+a,_i
\newline
-And if there should be a shortage of ideas then you can always point students
- to the ever-growing feature request list
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
+rl\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+a
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+_i,a
+\layout Standard
-\end_inset
+SDCC uses pattern matching on the parse tree to determine this operation.Variatio
+ns of this case will also be recognized as bit-rotation, i.e.:
+\layout Verse
-.
-\layout Enumerate
-not tie students to a specific host platform and instead allow them to use
- a host platform of
-\emph on
-their
-\emph default
- choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
- eventually
-\begin_inset LatexCommand \url[OLPC]{http://wiki.laptop.org/wiki/One_Laptop_per_Child}
+\family typewriter
+i = ((i >> 7) | (i << 1)); /* left-bit rotation */
+\layout Subsection
-\end_inset
+Nibble and Byte Swapping
+\layout Standard
-)
-\layout Enumerate
+Other special cases of the bit-shift operations are nibble or byte swapping
+\begin_inset LatexCommand \index{swapping nibbles/bytes}
-not encourage students to use illegal copies of educational software
-\layout Enumerate
+\end_inset
-be immune to licensing/availability/price changes of the chosen tool chain
-\layout Enumerate
+, SDCC recognizes the following expressions:
+\layout Verse
-be able to change to a new target platform without having to adopt a new
- tool chain
-\layout Enumerate
-have complete control over and insight into the tool chain
-\layout Enumerate
+\family typewriter
+\series bold
+unsigned
+\series default
+\SpecialChar ~
+\SpecialChar ~
+char i;
+\newline
-make your students aware about the pros and cons of open source software
- development
-\layout Enumerate
+\series bold
+unsigned
+\series default
+\SpecialChar ~
+\SpecialChar ~
+int j;
+\newline
+...
+
+\newline
+i = ((i << 4) | (i >> 4));
+\family default
-give back to the public as you are probably at least partially publically
- funded
-\layout Enumerate
+\newline
-give students a chance to publically prove their skills and to possibly
- see a world wide impact
+\family typewriter
+j = ((j << 8) | (j >> 8));
\layout Standard
-then SDCC is probably among the first choices.
- Well, probably SDCC might be the only choice.
-\layout Chapter
-\pagebreak_top
-SDCC Technical Data
-\layout Section
-
-Optimizations
-\begin_inset LatexCommand \index{Optimizations}
+and generates a swap instruction for the nibble swapping
+\begin_inset LatexCommand \index{Nibble swapping}
\end_inset
-
-\layout Standard
-
-SDCC performs a host of standard optimizations in addition to some MCU specific
- optimizations.
-
-\layout Subsection
-
-Sub-expression Elimination
-\begin_inset LatexCommand \index{Subexpression elimination}
+ or move instructions for the byte swapping
+\begin_inset LatexCommand \index{Byte swapping}
\end_inset
+.
+ The
+\begin_inset Quotes sld
+\end_inset
-\layout Standard
+j
+\begin_inset Quotes srd
+\end_inset
-The compiler does local and
-\emph on
-g
-\emph default
-lobal
-\emph on
-c
-\emph default
-ommon
-\emph on
-s
-\emph default
-ubexpression
+ example can be used to convert from little to big-endian or vice versa.
+ If you want to change the endianness of a
\emph on
-e
+signed
\emph default
-limination, e.g.:
-\layout Verse
+ integer you have to cast to
+\family typewriter
+(unsigned int)
+\family default
+ first.
+\layout Standard
+Note that SDCC stores numbers in little-endian
+\begin_inset Foot
+collapsed false
-\family typewriter
-i = x + y + 1;
-\newline
-j = x + y;
\layout Standard
-will be translated to
-\layout Verse
+Usually 8-bit processors don't care much about endianness.
+ This is not the case for the standard 8051 which only has an instruction
+ to increment its
+\emph on
+dptr
+\emph default
+\begin_inset LatexCommand \index{DPTR}
-\family typewriter
-iTemp = x + y;
-\newline
-i = iTemp + 1;
-\newline
-j = iTemp;
-\layout Standard
+\end_inset
-Some subexpressions are not as obvious as the above example, e.g.:
-\layout Verse
+-datapointer
+\emph on
+
+\emph default
+so little-endian is the more efficient byte order.
+\end_inset
-\family typewriter
-a->b[i].c = 10;
-\newline
-a->b[i].d = 11;
-\layout Standard
+\begin_inset LatexCommand \index{little-endian}
-In this case the address arithmetic a->b[i] will be computed only once;
- the equivalent code in C would be.
-\layout Verse
+\end_inset
-\family typewriter
-iTemp = a->b[i];
-\newline
-iTemp.c = 10;
-\newline
-iTemp.d = 11;
-\layout Standard
+\begin_inset LatexCommand \index{Endianness}
-The compiler will try to keep these temporary variables in registers.
+\end_inset
+
+ format (i.e.
+ lowest order first).
\layout Subsection
-Dead-Code Elimination
-\begin_inset LatexCommand \index{Dead-code elimination}
+Highest Order Bit
+\begin_inset LatexCommand \index{Highest Order Bit}
+
+\end_inset
+
+ / Any Order Bit
+\begin_inset LatexCommand \index{Any Order Bit}
\end_inset
+\layout Standard
+
+It is frequently required to obtain the highest order bit of an integral
+ type (long, int, short or char types).
+ Also obtaining any other order bit is not uncommon.
+ SDCC recognizes the following expressions to yield the highest order bit
+ and generates optimized code for it, e.g.:
\layout Verse
\family typewriter
-int global;
+unsigned int gint;
\newline
\newline
-void f () {
+foo () {
\newline
\SpecialChar ~
\SpecialChar ~
-int i;
+unsigned char hob1, aob1;
\newline
\SpecialChar ~
\SpecialChar ~
-i = 1; \SpecialChar ~
+bit hob2, hob3, aob2, aob3;
+\newline
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
-/* dead store */
+hob1 = (gint >> 15) & 1;
\newline
\SpecialChar ~
\SpecialChar ~
-global = 1;\SpecialChar ~
-/* dead store */
+hob2 = (gint >> 15) & 1;
\newline
\SpecialChar ~
\SpecialChar ~
-global = 2;
+hob3 = gint & 0x8000;
\newline
\SpecialChar ~
\SpecialChar ~
-return;
+aob1 = (gint >> 9) & 1;
\newline
\SpecialChar ~
\SpecialChar ~
-global = 3;\SpecialChar ~
-/* unreachable */
-\newline
-}
-\layout Standard
-
-will be changed to
-\layout Verse
-
-
-\family typewriter
-int global;
-\newline
-
+aob2 = (gint >> 8) & 1;
\newline
-void f () {
+\SpecialChar ~
+\SpecialChar ~
+aob3 = gint & 0x0800;
\newline
\SpecialChar ~
\SpecialChar ~
-global = 2;
+..
+
\newline
}
-\layout Subsection
-
-Copy-Propagation
-\begin_inset LatexCommand \index{Copy propagation}
-
-\end_inset
-
+\layout Standard
+will generate the following code:
\layout Verse
\family typewriter
-int f() {
-\newline
\SpecialChar ~
\SpecialChar ~
-int i, j;
-\newline
\SpecialChar ~
\SpecialChar ~
-i = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-j = i;
-\newline
\SpecialChar ~
\SpecialChar ~
-return j;
-\newline
-}
-\layout Standard
-
-will be changed to
-\layout Verse
-
-
-\family typewriter
-int f() {
-\newline
\SpecialChar ~
\SpecialChar ~
-int i, j;
-\newline
\SpecialChar ~
\SpecialChar ~
-i = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-j = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-return 10;
-\newline
-}
-\layout Standard
-
-Note: the dead stores created by this copy propagation will be eliminated
- by dead-code elimination.
-\layout Subsection
-
-Loop Optimizations
-\begin_inset LatexCommand \index{Loop optimization}
-
-\end_inset
-
-
-\begin_inset LatexCommand \label{sub:Loop-Optimizations}
-
-\end_inset
-
-
-\layout Standard
-
-Two types of loop optimizations are done by SDCC
-\emph on
-loop invariant
-\emph default
- lifting and
-\emph on
- strength reduction
-\emph default
- of loop induction variables.
- In addition to the strength reduction the optimizer marks the induction
- variables and the register allocator tries to keep the induction variables
- in registers for the duration of the loop.
- Because of this preference of the register allocator
-\begin_inset LatexCommand \index{Register allocation}
-
-\end_inset
-
-, loop induction optimization causes an increase in register pressure, which
- may cause unwanted spilling of other temporary variables into the stack
-\begin_inset LatexCommand \index{stack}
-
-\end_inset
-
- / data space.
- The compiler will generate a warning message when it is forced to allocate
- extra space either on the stack or data space.
- If this extra space allocation is undesirable then induction optimization
- can be eliminated either for the entire source file (with -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--noinduction option) or for a given function only using #pragma\SpecialChar ~
-noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
-
-\end_inset
-
-.
-\newline
-
-\newline
-Loop Invariant:
-\layout Verse
-
-
-\family typewriter
-for (i = 0 ; i < 100 ; i ++)
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-f += k + l;
-\layout Standard
-
-changed to
-\layout Verse
-
-
-\family typewriter
-itemp = k + l;
-\newline
-for (i = 0; i < 100; i++)
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-f += itemp;
-\layout Standard
-
-As mentioned previously some loop invariants are not as apparent, all static
- address computations are also moved out of the loop.
-\newline
-
-\newline
-Strength Reduction
-\begin_inset LatexCommand \index{Strength reduction}
-
-\end_inset
-
-, this optimization substitutes an expression by a cheaper expression:
-\layout Verse
-
-
-\family typewriter
-for (i=0;i < 100; i++)
+\SpecialChar ~
+ 61 ;\SpecialChar ~
+ hob.c 7
\newline
+000A E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ar[i*5] = i*3;
-\layout Standard
-
-changed to
-\layout Verse
-
-
-\family typewriter
-itemp1 = 0;
-\newline
-itemp2 = 0;
-\newline
-for (i=0;i< 100;i++) {
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 62\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
+000C 23\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ar[itemp1] = itemp2;
-\newline
\SpecialChar ~
\SpecialChar ~
+ 63\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-itemp1 += 5;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-itemp2 += 3;
-\newline
-}
-\layout Standard
-
-The more expensive multiplication
-\begin_inset LatexCommand \index{Multiplication}
-
-\end_inset
-
- is changed to a less expensive addition.
-\layout Subsection
-
-Loop Reversing
-\begin_inset LatexCommand \index{Loop reversing}
-
-\end_inset
-
-
-\layout Standard
-
-This optimization is done to reduce the overhead of checking loop boundaries
- for every iteration.
- Some simple loops can be reversed and implemented using a
-\begin_inset Quotes eld
-\end_inset
-
-decrement and jump if not zero
-\begin_inset Quotes erd
-\end_inset
-
- instruction.
- SDCC checks for the following criterion to determine if a loop is reversible
- (note: more sophisticated compilers use data-dependency analysis to make
- this determination, SDCC uses a more simple minded analysis).
-\layout Itemize
-
-The 'for' loop is of the form
-\newline
-
-\newline
-
-\family typewriter
-for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
- += 1])
-\newline
\SpecialChar ~
+ rl\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ a
+\newline
+000D 54 01\SpecialChar ~
\SpecialChar ~
-<for body>
-\layout Itemize
-
-The <for body> does not contain
-\begin_inset Quotes eld
-\end_inset
-
-continue
-\begin_inset Quotes erd
-\end_inset
-
- or 'break
-\begin_inset Quotes erd
-\end_inset
-
-.
-\layout Itemize
-
-All goto's are contained within the loop.
-\layout Itemize
-
-No function calls within the loop.
-\layout Itemize
-
-The loop control variable <sym> is not assigned any value within the loop
-\layout Itemize
-
-The loop control variable does NOT participate in any arithmetic operation
- within the loop.
-\layout Itemize
-
-There are NO switch statements in the loop.
-\layout Subsection
-
-Algebraic Simplifications
-\layout Standard
-
-SDCC does numerous algebraic simplifications, the following is a small sub-set
- of these optimizations.
-\layout Verse
-
-
-\family typewriter
-i = j + 0;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i = j;
-\newline
-i /= 2;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
+ 64\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i >>= 1;
-\newline
-i = j - j;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ anl\SpecialChar ~
\SpecialChar ~
- i = 0;
+ a,#0x01
\newline
-i = j / 1;\SpecialChar ~
+000F F5*02\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i = j;
-\layout Standard
-
-Note the subexpressions
-\begin_inset LatexCommand \index{Subexpression}
-
-\end_inset
-
- given above are generally introduced by macro expansions or as a result
- of copy/constant propagation.
-\layout Subsection
-
-'switch' Statements
-\begin_inset LatexCommand \label{sub:'switch'-Statements}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{switch statement}
-
-\end_inset
-
-
-\layout Standard
-
-SDCC can optimize switch statements to jump tables
-\begin_inset LatexCommand \index{jump tables}
-
-\end_inset
-
-.
- It makes the decision based on an estimate of the generated code size.
- SDCC is quite liberal in the requirements for jump table generation:
-\layout Itemize
-
-The labels need not be in order, and the starting number need not be one
- or zero, the case labels are in numerical sequence or not too many case
- labels are missing.
-\begin_deeper
-\layout Verse
-
-
-\family typewriter
-switch(i) {\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 65\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_hob1_1_1,a
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 4: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 66 ;\SpecialChar ~
+ hob.c 8
+\newline
+0011 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 0: ...
-
-\newline
\SpecialChar ~
+ 67\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 5: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0013 33\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 68\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 3: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ rlc\SpecialChar ~
\SpecialChar ~
+ a
+\newline
+0014 92*00\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 69\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-
+ _foo_hob2_1_1,c
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 6: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 66 ;\SpecialChar ~
+ hob.c 9
+\newline
+0016 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 7: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 67\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0018 33\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 4: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 8: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
+ 68\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ rlc\SpecialChar ~
\SpecialChar ~
+ a
+\newline
+0019 92*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 5: ...
-
-\newline
+ 69\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 9: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_hob3_1_1,c
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 6: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 10: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 70 ;\SpecialChar ~
+ hob.c 10
+\newline
+001B E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 71\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-case 7: ...
-
+ a,(_gint + 1)
\newline
+001D 03\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 11: ...\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 72\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ rr\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 8: ...
-
+ a
\newline
-}\SpecialChar ~
+001E 54 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
+ 73\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ anl\SpecialChar ~
+\SpecialChar ~
+ a,#0x01
+\newline
+0020 F5*03\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 74\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-}
-\layout Standard
-
-Both the above switch statements will be implemented using a jump-table.
- The example to the right side is slightly more efficient as the check for
- the lower boundary of the jump-table is not needed.
-\end_deeper
-\layout Itemize
-
-The number of case labels is not larger than supported by the target architectur
-e.
-\layout Itemize
-
-If the case labels are not in numerical sequence ('gaps' between cases)
- SDCC checks whether a jump table with additionally inserted dummy cases
- is still attractive.
-
-\layout Itemize
-
-If the starting number is not zero and a check for the lower boundary of
- the jump-table can thus be eliminated SDCC might insert dummy cases 0,
- ...
- .
-\layout Standard
-
-Switch statements which have large gaps in the numeric sequence or those
- that have too many case labels can be split into more than one switch statement
- for efficient code generation, e.g.:
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
-\newline
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-case 2: ...
-
+ _foo_aob1_1_1,a
\newline
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
-\newline
-\SpecialChar ~
\SpecialChar ~
-case 4: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 5: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 6: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 7: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 101: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 102: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 103: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 104: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 105: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 106: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 107: ...
-
-\newline
-}
-\layout Standard
-
-If the above switch statement is broken down into two switch statements
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
+ 75 ;\SpecialChar ~
+ hob.c 11
\newline
+0022 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 2: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 4: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 5: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 6: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 7: ...
-
-\newline
-}
-\layout Standard
-
-and
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 101: ...
-
-\newline
+ 76\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 102: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 103: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 104: ...
-
-\newline
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-case 105: ...
-
+ a,(_gint + 1)
\newline
+0024 13\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 106: ...
-
-\newline
-\SpecialChar ~
\SpecialChar ~
-case 107: ...
-
-\newline
-}
-\layout Standard
-
-then both the switch statements will be implemented using jump-tables whereas
- the unmodified switch statement will not be.
-\layout Comment
-
-There might be reasons which SDCC cannot know about to either favour or
- not favour jump tables.
- If the target system has to be as quick for the last switch case as for
- the first (pro jump table), or if the switch argument is known to be zero
- in the majority of the cases (contra jump table).
-\layout Standard
-
-The pragma nojtbound
-\begin_inset LatexCommand \index{\#pragma nojtbound}
-
-\end_inset
-
- can be used to turn off checking the
-\emph on
-j
-\emph default
-ump
-\emph on
-t
-\emph default
-able
-\emph on
-bound
-\emph default
-aries.
- It has no effect if a default label is supplied.
- Use of this pragma is dangerous: if the switch
-\begin_inset LatexCommand \index{switch statement}
-
-\end_inset
-
- argument is not matched by a case statement the processor will happily
- jump into Nirvana.
-\layout Subsection
-
-Bit-shifting Operations
-\begin_inset LatexCommand \index{Bit shifting}
-
-\end_inset
-
-.
-\layout Standard
-
-Bit shifting is one of the most frequently used operation in embedded programmin
-g.
- SDCC tries to implement bit-shift operations in the most efficient way
- possible, e.g.:
-\layout Verse
-
-
-\family typewriter
-unsigned char i;
-\newline
-...
-
-\newline
-i >>= 4;
-\newline
-...
-\layout Standard
-
-generates the following code:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
- a,_i
-\newline
-swap a
-\newline
-anl\SpecialChar ~
- a,#0x0f
-\newline
-mov\SpecialChar ~
- _i,a
-\layout Standard
-
-In general SDCC will never setup a loop if the shift count is known.
- Another example:
-\layout Verse
-
-
-\family typewriter
-unsigned int i;
-\newline
-...
-
-\newline
-i >>= 9;
-\newline
-...
-\layout Standard
-
-will generate:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
\SpecialChar ~
-a,(_i + 1)
-\newline
-mov\SpecialChar ~
\SpecialChar ~
-(_i + 1),#0x00
-\newline
-clr\SpecialChar ~
\SpecialChar ~
-c
-\newline
-rrc\SpecialChar ~
\SpecialChar ~
-a
-\newline
-mov\SpecialChar ~
\SpecialChar ~
-_i,a
-\layout Subsection
-
-Bit-rotation
-\begin_inset LatexCommand \index{Bit rotation}
-
-\end_inset
-
-
-\layout Standard
-
-A special case of the bit-shift operation is bit rotation
-\begin_inset LatexCommand \index{rotating bits}
-
-\end_inset
-
-, SDCC recognizes the following expression to be a left bit-rotation:
-\layout Verse
-
-
-\family typewriter
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-char i;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 77\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* unsigned is needed for rotation */
-\newline
-...
-
-\newline
-i = ((i << 1) | (i >> 7));
-\family default
-
-\newline
-
-\family typewriter
-...
-\layout Standard
-
-will generate the following code:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
\SpecialChar ~
-a,_i
-\newline
-rl\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-a
+\SpecialChar ~
+ rrc\SpecialChar ~
+\SpecialChar ~
+ a
\newline
-mov\SpecialChar ~
+0025 92*02\SpecialChar ~
\SpecialChar ~
-_i,a
-\layout Standard
-
-SDCC uses pattern matching on the parse tree to determine this operation.Variatio
-ns of this case will also be recognized as bit-rotation, i.e.:
-\layout Verse
-
-
-\family typewriter
-i = ((i >> 7) | (i << 1)); /* left-bit rotation */
-\layout Subsection
-
-Nibble and Byte Swapping
-\layout Standard
-
-Other special cases of the bit-shift operations are nibble or byte swapping
-\begin_inset LatexCommand \index{swapping nibbles/bytes}
-
-\end_inset
-
-, SDCC recognizes the following expressions:
-\layout Verse
-
-
-\family typewriter
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-char i;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 78\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob2_1_1,c
\newline
-
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-int j;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 79 ;\SpecialChar ~
+ hob.c 12
\newline
-...
-
+0027 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 80\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
-i = ((i << 4) | (i >> 4));
-\family default
-
+0029 A2 E3\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 81\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ c,acc[3]
\newline
-
-\family typewriter
-j = ((j << 8) | (j >> 8));
-\layout Standard
-
-and generates a swap instruction for the nibble swapping
-\begin_inset LatexCommand \index{Nibble swapping}
-
-\end_inset
-
- or move instructions for the byte swapping
-\begin_inset LatexCommand \index{Byte swapping}
-
-\end_inset
-
-.
- The
-\begin_inset Quotes sld
-\end_inset
-
-j
-\begin_inset Quotes srd
-\end_inset
-
- example can be used to convert from little to big-endian or vice versa.
- If you want to change the endianness of a
-\emph on
-signed
-\emph default
- integer you have to cast to
-\family typewriter
-(unsigned int)
-\family default
- first.
-\layout Standard
-
-Note that SDCC stores numbers in little-endian
-\begin_inset Foot
-collapsed false
-
+002B 92*03\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 82\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob3_1_1,c
\layout Standard
-Usually 8-bit processors don't care much about endianness.
- This is not the case for the standard 8051 which only has an instruction
- to increment its
-\emph on
-dptr
-\emph default
-
-\begin_inset LatexCommand \index{DPTR}
-
-\end_inset
-
--datapointer
+Other variations of these cases however will
\emph on
-
+not
\emph default
-so little-endian is the more efficient byte order.
-\end_inset
-
-
-\begin_inset LatexCommand \index{little-endian}
-
-\end_inset
-
+ be recognized.
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the highest order bit, (it is portable).
+ Of course it will be recognized even if it is embedded in other expressions,
+ e.g.:
+\layout Verse
-\begin_inset LatexCommand \index{Endianness}
-\end_inset
+\family typewriter
+xyz = gint + ((gint >> 15) & 1);
+\layout Standard
- format (i.e.
- lowest order first).
+will still be recognized.
\layout Subsection
-Highest Order Bit
-\begin_inset LatexCommand \index{Highest Order Bit}
+Higher Order Byte
+\begin_inset LatexCommand \index{Higher Order Byte}
\end_inset
- / Any Order Bit
-\begin_inset LatexCommand \index{Any Order Bit}
+ / Higher Order Word
+\begin_inset LatexCommand \index{Higher Order Word}
\end_inset
\layout Standard
-It is frequently required to obtain the highest order bit of an integral
- type (long, int, short or char types).
- Also obtaining any other order bit is not uncommon.
- SDCC recognizes the following expressions to yield the highest order bit
- and generates optimized code for it, e.g.:
+It is also frequently required to obtain a higher order byte or word of
+ a larger integral type (long, int or short types).
+ SDCC recognizes the following expressions to yield the higher order byte
+ or word and generates optimized code for it, e.g.:
\layout Verse
\family typewriter
unsigned int gint;
\newline
+unsigned long int glong;
+\newline
\newline
foo () {
\newline
\SpecialChar ~
\SpecialChar ~
-unsigned char hob1, aob1;
+unsigned char hob1, hob2;
\newline
\SpecialChar ~
\SpecialChar ~
-bit hob2, hob3, aob2, aob3;
+unsigned int how1, how2;
\newline
\SpecialChar ~
\SpecialChar ~
\newline
\SpecialChar ~
\SpecialChar ~
-hob1 = (gint >> 15) & 1;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-hob2 = (gint >> 15) & 1;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-hob3 = gint & 0x8000;
+hob1 = (gint >> 8) & 0xFF;
\newline
\SpecialChar ~
\SpecialChar ~
-aob1 = (gint >> 9) & 1;
+hob2 = glong >> 24;
\newline
\SpecialChar ~
\SpecialChar ~
-aob2 = (gint >> 8) & 1;
+how1 = (glong >> 16) & 0xFFFF;
\newline
\SpecialChar ~
\SpecialChar ~
-aob3 = gint & 0x0800;
+how2 = glong >> 8;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 61 ;\SpecialChar ~
- hob.c 7
+ 91 ;\SpecialChar ~
+ hob.c 15
\newline
-000A E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+0037 85*01*06\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 62\SpecialChar ~
+ 92\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
mov\SpecialChar ~
\SpecialChar ~
- a,(_gint + 1)
+ _foo_hob1_1_1,(_gint + 1)
\newline
-000C 23\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 63\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- rl\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- a
-\newline
-000D 54 01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 64\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- anl\SpecialChar ~
\SpecialChar ~
- a,#0x01
+ 93 ;\SpecialChar ~
+ hob.c 16
\newline
-000F F5*02\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+003A 85*05*07\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 65\SpecialChar ~
+ 94\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
mov\SpecialChar ~
\SpecialChar ~
- _foo_hob1_1_1,a
+ _foo_hob2_1_1,(_glong + 3)
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 66 ;\SpecialChar ~
- hob.c 8
+ 95 ;\SpecialChar ~
+ hob.c 17
\newline
-0011 E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+003D 85*04*08\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 67\SpecialChar ~
+ 96\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
mov\SpecialChar ~
\SpecialChar ~
- a,(_gint + 1)
+ _foo_how1_1_1,(_glong + 2)
\newline
-0013 33\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+0040 85*05*09\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 68\SpecialChar ~
+ 97\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- rlc\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
- a
+ (_foo_how1_1_1 + 1),(_glong + 3)
\newline
-0014 92*00\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
+0043 85*03*0A\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 69\SpecialChar ~
+ 98\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
mov\SpecialChar ~
\SpecialChar ~
- _foo_hob2_1_1,c
+ _foo_how2_1_1,(_glong + 1)
\newline
+0046 85*04*0B\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 99\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 66 ;\SpecialChar ~
- hob.c 9
+ (_foo_how2_1_1 + 1),(_glong + 2)
+\layout Standard
+
+Again, variations of these cases may
+\emph on
+not
+\emph default
+ be recognized.
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the higher order byte/word, (it is portable).
+ Of course it will be recognized even if it is embedded in other expressions,
+ e.g.:
+\layout Verse
+
+
+\family typewriter
+xyz = gint + ((gint >> 8) & 0xFF);
+\layout Standard
+
+will still be recognized.
+\layout Subsection
+
+Peephole Optimizer
+\begin_inset LatexCommand \label{sub:Peephole-Optimizer}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Peephole optimizer}
+
+\end_inset
+
+
+\layout Standard
+
+The compiler uses a rule based, pattern matching and re-writing mechanism
+ for peep-hole optimization.
+ It is inspired by
+\emph on
+copt
+\emph default
+ a peep-hole optimizer by Christopher W.
+ Fraser (cwfraser\SpecialChar ~
+@\SpecialChar ~
+microsoft.com).
+ A default set of rules are compiled into the compiler, additional rules
+ may be added with the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-file
+\begin_inset LatexCommand \index{-\/-peep-file}
+
+\end_inset
+
+ <filename>
+\emph default
+ option.
+ The rule language is best illustrated with examples.
+\layout Verse
+
+
+\family typewriter
+replace {
\newline
-0016 E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 67\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- a,(_gint + 1)
+mov %1,a
\newline
-0018 33\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 68\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+mov a,%1
+\newline
+} by {
+\newline
\SpecialChar ~
\SpecialChar ~
+mov %1,a
+\newline
+}
+\layout Standard
+
+The above rule will change the following assembly
+\begin_inset LatexCommand \index{Assembler routines}
+
+\end_inset
+
+ sequence:
+\layout Verse
+
+
+\family typewriter
+mov r1,a
+\newline
+mov a,r1
+\layout Standard
+
+to
+\layout Verse
+
+
+\family typewriter
+mov r1,a
+\layout Standard
+
+Note: All occurrences of a
+\emph on
+%n
+\emph default
+ (pattern variable) must denote the same string.
+ With the above rule, the assembly sequence:
+\layout Verse
+
+
+\family typewriter
+mov r1,a
+\newline
+mov a,r2
+\layout Standard
+
+will remain unmodified.
+\newline
+
+\newline
+Other special case optimizations may be added by the user (via
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-file option
+\emph default
+).
+ E.g.
+ some variants of the 8051 MCU
+\begin_inset LatexCommand \index{MCS51 variants}
+
+\end_inset
+
+ allow only
+\family typewriter
+ajmp
+\family default
+ and
+\family typewriter
+acall
+\family default
+.
+ The following two rules will change all
+\family typewriter
+ljmp
+\family default
+ and
+\family typewriter
+lcall
+\family default
+ to
+\family typewriter
+ajmp
+\family default
+ and
+\family typewriter
+acall
+\layout Verse
+
+
+\family typewriter
+replace { lcall %1 } by { acall %1 }
+\newline
+replace { ljmp %1 } by { ajmp %1 }
+\layout Standard
+
+The
+\emph on
+inline-assembler code
+\emph default
+ is also passed through the peep hole optimizer, thus the peephole optimizer
+ can also be used as an assembly level macro expander.
+ The rules themselves are MCU dependent whereas the rule language infra-structur
+e is MCU independent.
+ Peephole optimization rules for other MCU can be easily programmed using
+ the rule language.
+\newline
+
+\newline
+The syntax for a rule is as follows:
+\layout Verse
+
+
+\family typewriter
+rule := replace [ restart ] '{' <assembly sequence> '
+\backslash
+n'
+\newline
\SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ '}' by '{' '
+\backslash
+n'
+\newline
\SpecialChar ~
- rlc\SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ <assembly sequence> '
+\backslash
+n'
+\newline
\SpecialChar ~
- a
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ '}' [if <functionName> ] '
+\backslash
+n'
+\layout Standard
+
+<assembly sequence> := assembly instruction (each instruction including
+ labels must be on a separate line).
+\newline
+
+\newline
+The optimizer will apply to the rules one by one from the top in the sequence
+ of their appearance, it will terminate when all rules are exhausted.
+ If the 'restart' option is specified, then the optimizer will start matching
+ the rules again from the top, this option for a rule is expensive (performance)
+, it is intended to be used in situations where a transformation will trigger
+ the same rule again.
+ An example of this (not a good one, it has side effects) is the following
+ rule:
+\layout Verse
+
+
+\family typewriter
+replace restart {
\newline
-0019 92*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 69\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_hob3_1_1,c
+pop %1
\newline
\SpecialChar ~
\SpecialChar ~
+push %1 } by {
+\newline
\SpecialChar ~
\SpecialChar ~
+; nop
+\newline
+}
+\layout Standard
+
+Note that the replace pattern cannot be a blank, but can be a comment line.
+ Without the 'restart' option only the innermost 'pop' 'push' pair would
+ be eliminated, i.e.:
+\layout Verse
+
+
+\family typewriter
+pop ar1
+\newline
+pop ar2
+\newline
+push ar2
+\newline
+push ar1
+\layout Standard
+
+would result in:
+\layout Verse
+
+
+\family typewriter
+pop ar1
+\newline
+; nop
+\newline
+push ar1
+\layout Standard
+
+
+\emph on
+with
+\emph default
+ the restart option the rule will be applied again to the resulting code
+ and then all the pop-push pairs will be eliminated to yield:
+\layout Verse
+
+
+\family typewriter
+; nop
+\newline
+; nop
+\layout Standard
+
+A conditional function can be attached to a rule.
+ Attaching rules are somewhat more involved, let me illustrate this with
+ an example.
+\layout Verse
+
+
+\family typewriter
+replace {
+\newline
\SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ljmp %5
+\newline
+%2:
+\newline
+} by {
+\newline
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 70 ;\SpecialChar ~
- hob.c 10
+ \SpecialChar ~
+ \SpecialChar ~
+sjmp %5
+\newline
+%2:
+\newline
+} if labelInRange
+\layout Standard
+
+The optimizer does a look-up of a function name table defined in function
+
+\emph on
+callFuncByName
+\emph default
+ in the source file SDCCpeeph.c, with the name
+\emph on
+labelInRange
+\emph default
+.
+ If it finds a corresponding entry the function is called.
+ Note there can be no parameters specified for these functions, in this
+ case the use of
+\emph on
+%5
+\emph default
+ is crucial, since the function
+\emph on
+labelInRange
+\emph default
+ expects to find the label in that particular variable (the hash table containin
+g the variable bindings is passed as a parameter).
+ If you want to code more such functions, take a close look at the function
+ labelInRange and the calling mechanism in source file SDCCpeeph.c.
+ Currently implemented are
+\emph on
+labelInRange, labelRefCount, labelIsReturnOnly, operandsNotSame, xramMovcOption,
+ 24bitMode, portIsDS390, 24bitModeAndPortDS390
+\emph default
+and
+\emph on
+ notVolatile
+\emph default
+.
+\layout Standard
+
+I know this whole thing is a little kludgey, but maybe some day we will
+ have some better means.
+ If you are looking at this file, you will see the default rules that are
+ compiled into the compiler, you can add your own rules in the default set
+ there if you get tired of specifying the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-file option.
+\layout Section
+
+ANSI-Compliance
+\begin_inset LatexCommand \index{ANSI-compliance}
+
+\end_inset
+
+
+\begin_inset LatexCommand \label{sub:ANSI-Compliance}
+
+\end_inset
+
+
+\layout Standard
+
+The latest publically available version of the standard
+\emph on
+ISO/IEC 9899 - Programming languages - C
+\emph default
+ should be available at:
+\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
+
+\end_inset
+
+.
+\newline
+
+\layout Standard
+
+Deviations from the compliance:
+\layout Itemize
+
+functions are not reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+ unless explicitly declared as such or the
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\series default
+ command line option is specified.
+\layout Itemize
+
+structures
+\begin_inset LatexCommand \index{struct}
+
+\end_inset
+
+ and unions
+\begin_inset LatexCommand \index{union}
+
+\end_inset
+
+ cannot be assigned values directly, cannot be passed as function parameters
+ or assigned to each other and cannot be a return value
+\begin_inset LatexCommand \index{return value}
+
+\end_inset
+
+ from a function, e.g.:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+struct s { ...
+ };
+\newline
+struct s s1, s2;
+\newline
+foo()
+\newline
+{
\newline
-001B E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 71\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- mov\SpecialChar ~
\SpecialChar ~
- a,(_gint + 1)
+s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
\newline
-001D 03\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
+}
+\newline
+
+\series bold
+struct
+\series default
+ s foo1 (
+\series bold
+struct
+\series default
+ s parms) /* invalid in SDCC although allowed in ANSI */
+\newline
+{
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+struct s rets;
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 72\SpecialChar ~
\SpecialChar ~
+return rets; /* is invalid in SDCC although allowed in ANSI */
+\newline
+}
+\end_deeper
+\layout Itemize
+
+initialization of structure arrays must be fully braced.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+struct s { char x } a[] = {1, 2};\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+/* invalid in SDCC */
+\newline
+struct s { char x } a[] = {{1}, {2}}; /* OK */
+\end_deeper
+\layout Itemize
+
+'long long
+\begin_inset LatexCommand \index{long long (not supported)}
+
+\end_inset
+
+' (64 bit integers
+\begin_inset LatexCommand \index{int (64 bit) (not supported)}
+
+\end_inset
+
+) not supported.
+\layout Itemize
+
+'double
+\begin_inset LatexCommand \index{double (not supported)}
+
+\end_inset
+
+' precision floating point
+\begin_inset LatexCommand \index{Floating point support}
+
+\end_inset
+
+not supported.
+\layout Itemize
+
+Old K&R style
+\begin_inset LatexCommand \index{K\&R style}
+
+\end_inset
+
+ function declarations are NOT allowed.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+foo(i,j) /* this old style of function declarations */
+\newline
+int i,j; /* are valid in ANSI but not valid in SDCC */
+\newline
+{
+\newline
\SpecialChar ~
\SpecialChar ~
- rr\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- a
+...
+
+\newline
+}
+\end_deeper
+\layout Itemize
+
+Most enhancements in C99 are not supported, f.e.:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+\series bold
+inline
+\begin_inset LatexCommand \index{inline (not supported)}
+
+\end_inset
+
+
+\series default
+ int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
+ in C99.
+ An empty define
+\emph on
+#define inline
+\emph default
+ can be used as a work around */
+\newline
+
+\newline
+for (
+\series bold
+int
+\series default
+ i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
+\end_deeper
+\layout Itemize
+
+Certain words that are valid identifiers in the standard may be reserved
+ words in SDCC unless the
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
+
+\end_inset
+
+ or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+
+\end_inset
+
+
+\series default
+ command line options are used.
+ These may include (depending on the selected processor): 'at', 'banked',
+ 'bit', 'code', 'critical', 'data', 'eeprom', 'far', 'flash', 'idata', 'interrup
+t', 'near', 'nonbanked', 'pdata', 'reentrant', 'sbit', 'sfr', 'shadowregs',
+ 'sram', 'using', 'wparam', 'xdata', '_overlay', '_asm', '_endasm', and
+ '_naked'.
+ Compliant equivalents of these keywords are always available in a form
+ that begin with two underscores
+\begin_inset LatexCommand \index{\_\_ (prefix for extended keywords)}
+
+\end_inset
+
+, f.e.
+ '__data' instead of 'data'.
+\layout Section
+
+Cyclomatic Complexity
+\begin_inset LatexCommand \index{Cyclomatic complexity}
+
+\end_inset
+
+
+\layout Standard
+
+Cyclomatic complexity of a function is defined as the number of independent
+ paths the program can take during execution of the function.
+ This is an important number since it defines the number test cases you
+ have to generate to validate the function.
+ The accepted industry standard for complexity number is 10, if the cyclomatic
+ complexity reported by SDCC exceeds 10 you should think about simplification
+ of the function logic.
+ Note that the complexity level is not related to the number of lines of
+ code in a function.
+ Large functions can have low complexity, and small functions can have large
+ complexity levels.
+
+\newline
+
+\newline
+SDCC uses the following formula to compute the complexity:
+\newline
+
+\layout Standard
+
+complexity = (number of edges in control flow graph) - (number of nodes
+ in control flow graph) + 2;
+\newline
+
+\newline
+Having said that the industry standard is 10, you should be aware that in
+ some cases it be may unavoidable to have a complexity level of less than
+ 10.
+ For example if you have switch statement with more than 10 case labels,
+ each case label adds one to the complexity level.
+ The complexity level is by no means an absolute measure of the algorithmic
+ complexity of the function, it does however provide a good starting point
+ for which functions you might look at for further optimization.
+\layout Section
+
+Retargetting for other Processors
+\layout Standard
+
+The issues for retargetting the compiler are far too numerous to be covered
+ by this document.
+ What follows is a brief description of each of the seven phases of the
+ compiler and its MCU dependency.
+\layout Itemize
+
+Parsing the source and building the annotated parse tree.
+ This phase is largely MCU independent (except for the language extensions).
+ Syntax & semantic checks are also done in this phase, along with some initial
+ optimizations like back patching labels and the pattern matching optimizations
+ like bit-rotation etc.
+\layout Itemize
+
+The second phase involves generating an intermediate code which can be easy
+ manipulated during the later phases.
+ This phase is entirely MCU independent.
+ The intermediate code generation assumes the target machine has unlimited
+ number of registers, and designates them with the name iTemp.
+ The compiler can be made to dump a human readable form of the code generated
+ by using the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpraw option.
+\layout Itemize
+
+This phase does the bulk of the standard optimizations and is also MCU independe
+nt.
+ This phase can be broken down into several sub-phases:
\newline
-001E 54 01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 73\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- anl\SpecialChar ~
-\SpecialChar ~
- a,#0x01
+
\newline
-0020 F5*03\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 74\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_aob1_1_1,a
+Break down intermediate code (iCode) into basic blocks.
\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 75 ;\SpecialChar ~
- hob.c 11
+Do control flow & data flow analysis on the basic blocks.
\newline
-0022 E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 76\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- a,(_gint + 1)
+Do local common subexpression elimination, then global subexpression elimination
\newline
-0024 13\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 77\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- rrc\SpecialChar ~
-\SpecialChar ~
- a
+Dead code elimination
\newline
-0025 92*02\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 78\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_aob2_1_1,c
+Loop optimizations
\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 79 ;\SpecialChar ~
- hob.c 12
+If loop optimizations caused any changes then do 'global subexpression eliminati
+on' and 'dead code elimination' again.
+\layout Itemize
+
+This phase determines the live-ranges; by live range I mean those iTemp
+ variables defined by the compiler that still survive after all the optimization
+s.
+ Live range analysis
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+ is essential for register allocation, since these computation determines
+ which of these iTemps will be assigned to registers, and for how long.
+\layout Itemize
+
+Phase five is register allocation.
+ There are two parts to this process.
+\newline
+
+\newline
+The first part I call 'register packing' (for lack of a better term).
+ In this case several MCU specific expression folding is done to reduce
+ register pressure.
+\newline
+
+\newline
+The second part is more MCU independent and deals with allocating registers
+ to the remaining live ranges.
+ A lot of MCU specific code does creep into this phase because of the limited
+ number of index registers available in the 8051.
+\layout Itemize
+
+The Code generation phase is (unhappily), entirely MCU dependent and very
+ little (if any at all) of this code can be reused for other MCU.
+ However the scheme for allocating a homogenized assembler operand for each
+ iCode operand may be reused.
+\layout Itemize
+
+As mentioned in the optimization section the peep-hole optimizer is rule
+ based system, which can reprogrammed for other MCUs.
+\layout Standard
+
+More information is available in a wiki
+\begin_inset LatexCommand \index{wiki}
+
+\end_inset
+
+ (preliminary link
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/release_wiki/index.php?page=SDCC+internals+and+porting}
+
+\end_inset
+
+) and in the thread
+\begin_inset LatexCommand \url{http://sf.net/mailarchive/message.php?msg_id=13954144}
+
+\end_inset
+
+ .
+\layout Chapter
+
+Compiler internals
+\begin_inset LatexCommand \index{Compiler internals}
+
+\end_inset
+
+
+\layout Section
+
+The anatomy of the compiler
+\begin_inset LatexCommand \label{sub:The-anatomy-of}
+
+\end_inset
+
+
+\layout Standard
+
+
+\shape italic
+This is an excerpt from an article published in Circuit Cellar Magazine
+ in
+\series bold
+August 2000
+\series default
+.
+ It's a little outdated (the compiler is much more efficient now and user/develo
+per friendly), but pretty well exposes the guts of it all.
+\shape default
+
\newline
-0027 E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 80\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- a,(_gint + 1)
+
\newline
-0029 A2 E3\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 81\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- c,acc[3]
+The current version of SDCC can generate code for Intel 8051 and Z80 MCU.
+ It is fairly easy to retarget for other 8-bit MCU.
+ Here we take a look at some of the internals of the compiler.
+
+\layout Paragraph*
+
+Parsing
+\begin_inset LatexCommand \index{Parsing}
+
+\end_inset
+
+
+\layout Standard
+
+Parsing the input source file and creating an AST (Annotated Syntax Tree
+\begin_inset LatexCommand \index{Annotated syntax tree}
+
+\end_inset
+
+).
+ This phase also involves propagating types (annotating each node of the
+ parse tree with type information) and semantic analysis.
+ There are some MCU specific parsing rules.
+ For example the storage classes, the extended storage classes are MCU specific
+ while there may be a xdata storage class for 8051 there is no such storage
+ class for z80 or Atmel AVR.
+ SDCC allows MCU specific storage class extensions, i.e.
+ xdata will be treated as a storage class specifier when parsing 8051 C
+ code but will be treated as a C identifier when parsing z80 or ATMEL AVR
+ C code.
+\layout Paragraph*
+
+Generating iCode
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+
+\layout Standard
+
+Intermediate code generation.
+ In this phase the AST is broken down into three-operand form (iCode).
+ These three operand forms are represented as doubly linked lists.
+ ICode is the term given to the intermediate form generated by the compiler.
+ ICode example section shows some examples of iCode generated for some simple
+ C source functions.
+\layout Paragraph*
+
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
+\end_inset
+
+.
+\layout Standard
+
+Bulk of the target independent optimizations is performed in this phase.
+ The optimizations include constant propagation, common sub-expression eliminati
+on, loop invariant code movement, strength reduction of loop induction variables
+ and dead-code elimination.
+\layout Paragraph*
+
+Live range analysis
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+
+\layout Standard
+
+During intermediate code generation phase, the compiler assumes the target
+ machine has infinite number of registers and generates a lot of temporary
+ variables.
+ The live range computation determines the lifetime of each of these compiler-ge
+nerated temporaries.
+ A picture speaks a thousand words.
+ ICode example sections show the live range annotations for each of the
+ operand.
+ It is important to note here, each iCode is assigned a number in the order
+ of its execution in the function.
+ The live ranges are computed in terms of these numbers.
+ The from number is the number of the iCode which first defines the operand
+ and the to number signifies the iCode which uses this operand last.
+\layout Paragraph*
+
+Register Allocation
+\begin_inset LatexCommand \index{Register allocation}
+
+\end_inset
+
+
+\layout Standard
+
+The register allocation determines the type and number of registers needed
+ by each operand.
+ In most MCUs only a few registers can be used for indirect addressing.
+ In case of 8051 for example the registers R0 & R1 can be used to indirectly
+ address the internal ram and DPTR to indirectly address the external ram.
+ The compiler will try to allocate the appropriate register to pointer variables
+ if it can.
+ ICode example section shows the operands annotated with the registers assigned
+ to them.
+ The compiler will try to keep operands in registers as much as possible;
+ there are several schemes the compiler uses to do achieve this.
+ When the compiler runs out of registers the compiler will check to see
+ if there are any live operands which is not used or defined in the current
+ basic block being processed, if there are any found then it will push that
+ operand and use the registers in this block, the operand will then be popped
+ at the end of the basic block.
+
+\layout Standard
+
+There are other MCU specific considerations in this phase.
+ Some MCUs have an accumulator; very short-lived operands could be assigned
+ to the accumulator instead of a general-purpose register.
+\layout Paragraph*
+
+Code generation
+\layout Standard
+
+Figure II gives a table of iCode
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+ operations supported by the compiler.
+ The code generation involves translating these operations into corresponding
+ assembly code for the processor.
+ This sounds overly simple but that is the essence of code generation.
+ Some of the iCode operations are generated on a MCU specific manner for
+ example, the z80 port does not use registers to pass parameters so the
+ SEND and RECV iCode operations will not be generated, and it also does
+ not support JUMPTABLES.
+
\newline
-002B 92*03\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 82\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_aob3_1_1,c
+
+\layout Standard
+
+
+\size footnotesize
+Figure II
+\begin_inset Tabular
+<lyxtabular version="3" rows="39" columns="4">
+<features islongtable="true" headBottomDL="true">
+<column alignment="block" valignment="top" leftline="true" width="13col%">
+<column alignment="left" valignment="top" leftline="true" width="13col%">
+<column alignment="block" valignment="top" leftline="true" width="22col%">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="40col%">
+<row topline="true" bottomline="true" endhead="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+iCode
+\series default
+
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Operands
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\series bold
+C Equivalent
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'!'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+NOT operation
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = ! IC_LEFT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'~'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Bitwise complement of
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = ~IC_LEFT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+RRC
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Rotate right with carry
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = (IC_LEFT << 1) | (IC_LEFT >> (sizeof(IC_LEFT)*8-1));
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+RLC
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Rotate left with carry
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = (IC_LEFT << (sizeof(LC_LEFT)*8-1) ) | (IC_LEFT >> 1);
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+GETHBIT
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Get the highest order bit of IC_LEFT
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = (IC_LEFT >> (sizeof(IC_LEFT)*8 -1));
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+UNARYMINUS
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Unary minus
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = - IC_LEFT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IPUSH
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Push the operand into stack
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+NONE
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IPOP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Pop the operand from the stack
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+NONE
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+CALL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Call the function represented by IC_LEFT
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT();
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+PCALL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Call via function pointer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = (*IC_LEFT)();
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+RETURN
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Return the value in operand IC_LEFT
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+return IC_LEFT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+LABEL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LABEL()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Label
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LABEL:
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+GOTO
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LABEL()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-Other variations of these cases however will
-\emph on
-not
-\emph default
- be recognized.
- They are standard C expressions, so I heartily recommend these be the only
- way to get the highest order bit, (it is portable).
- Of course it will be recognized even if it is embedded in other expressions,
- e.g.:
-\layout Verse
+\size footnotesize
+Goto label
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-xyz = gint + ((gint >> 15) & 1);
\layout Standard
-will still be recognized.
-\layout Subsection
-Higher Order Byte
-\begin_inset LatexCommand \index{Higher Order Byte}
+\size footnotesize
+goto IC_LABEL();
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\size footnotesize
+'+'
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
- / Higher Order Word
-\begin_inset LatexCommand \index{Higher Order Word}
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+\size footnotesize
+Addition
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-It is also frequently required to obtain a higher order byte or word of
- a larger integral type (long, int or short types).
- SDCC recognizes the following expressions to yield the higher order byte
- or word and generates optimized code for it, e.g.:
-\layout Verse
+\size footnotesize
+IC_RESULT = IC_LEFT + IC_RIGHT
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-\family typewriter
-unsigned int gint;
-\newline
-unsigned long int glong;
-\newline
-\newline
-foo () {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-unsigned char hob1, hob2;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-unsigned int how1, how2;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-\SpecialChar ~
-\SpecialChar ~
-hob1 = (gint >> 8) & 0xFF;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-hob2 = glong >> 24;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-how1 = (glong >> 16) & 0xFFFF;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-how2 = glong >> 8;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-..
-
-\newline
-}
+\size footnotesize
+'-'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Subtraction
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT - IC_RIGHT
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'*'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Multiplication
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT * IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'/'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Division
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT / IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'%'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Modulus
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT % IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-will generate the following code:
-\layout Verse
+\size footnotesize
+'<'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Less than
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 91 ;\SpecialChar ~
- hob.c 15
-\newline
-0037 85*01*06\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 92\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_hob1_1_1,(_gint + 1)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 93 ;\SpecialChar ~
- hob.c 16
-\newline
-003A 85*05*07\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 94\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_hob2_1_1,(_glong + 3)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 95 ;\SpecialChar ~
- hob.c 17
-\newline
-003D 85*04*08\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 96\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_how1_1_1,(_glong + 2)
-\newline
-0040 85*05*09\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 97\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- (_foo_how1_1_1 + 1),(_glong + 3)
-\newline
-0043 85*03*0A\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 98\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- _foo_how2_1_1,(_glong + 1)
-\newline
-0046 85*04*0B\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 99\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
-\SpecialChar ~
- (_foo_how2_1_1 + 1),(_glong + 2)
\layout Standard
-Again, variations of these cases may
-\emph on
-not
-\emph default
- be recognized.
- They are standard C expressions, so I heartily recommend these be the only
- way to get the higher order byte/word, (it is portable).
- Of course it will be recognized even if it is embedded in other expressions,
- e.g.:
-\layout Verse
+\size footnotesize
+IC_RESULT = IC_LEFT < IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-xyz = gint + ((gint >> 8) & 0xFF);
\layout Standard
-will still be recognized.
-\layout Subsection
-Peephole Optimizer
-\begin_inset LatexCommand \label{sub:Peephole-Optimizer}
+\size footnotesize
+'>'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{Peephole optimizer}
+\size footnotesize
+Greater than
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+\size footnotesize
+IC_RESULT = IC_LEFT > IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-The compiler uses a rule based, pattern matching and re-writing mechanism
- for peep-hole optimization.
- It is inspired by
-\emph on
-copt
-\emph default
- a peep-hole optimizer by Christopher W.
- Fraser (cwfraser\SpecialChar ~
-@\SpecialChar ~
-microsoft.com).
- A default set of rules are compiled into the compiler, additional rules
- may be added with the
-\emph on
--
-\begin_inset ERT
-status Collapsed
+
+\size footnotesize
+EQ_OP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--peep-file
-\begin_inset LatexCommand \index{-\/-peep-file}
+\layout Standard
+
+\size footnotesize
+Equal to
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- <filename>
-\emph default
- option.
- The rule language is best illustrated with examples.
-\layout Verse
+\layout Standard
-\family typewriter
-replace {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-mov %1,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-mov a,%1
-\newline
-} by {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-mov %1,a
-\newline
-}
+\size footnotesize
+IC_RESULT = IC_LEFT == IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+AND_OP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Logical and operation
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT && IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+OR_OP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Logical or operation
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT || IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'^'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+Exclusive OR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_RESULT = IC_LEFT ^ IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+'|'
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-The above rule will change the following assembly
-\begin_inset LatexCommand \index{Assembler routines}
+\size footnotesize
+Bitwise OR
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- sequence:
-\layout Verse
-
-
-\family typewriter
-mov r1,a
-\newline
-mov a,r1
\layout Standard
-to
-\layout Verse
+\size footnotesize
+IC_RESULT = IC_LEFT | IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-mov r1,a
\layout Standard
-Note: All occurrences of a
-\emph on
-%n
-\emph default
- (pattern variable) must denote the same string.
- With the above rule, the assembly sequence:
-\layout Verse
+\size footnotesize
+BITWISEAND
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-mov r1,a
-\newline
-mov a,r2
\layout Standard
-will remain unmodified.
-\newline
-\newline
-Other special case optimizations may be added by the user (via
-\emph on
--
-\begin_inset ERT
-status Collapsed
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--peep-file option
-\emph default
-).
- E.g.
- some variants of the 8051 MCU
-\begin_inset LatexCommand \index{MCS51 variants}
+\size footnotesize
+Bitwise AND
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- allow only
-\family typewriter
-ajmp
-\family default
- and
-\family typewriter
-acall
-\family default
-.
- The following two rules will change all
-\family typewriter
-ljmp
-\family default
- and
-\family typewriter
-lcall
-\family default
- to
-\family typewriter
-ajmp
-\family default
- and
-\family typewriter
-acall
-\layout Verse
+\layout Standard
-\family typewriter
-replace { lcall %1 } by { acall %1 }
-\newline
-replace { ljmp %1 } by { ajmp %1 }
-\layout Standard
+\size footnotesize
+IC_RESULT = IC_LEFT & IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-The
-\emph on
-inline-assembler code
-\emph default
- is also passed through the peep hole optimizer, thus the peephole optimizer
- can also be used as an assembly level macro expander.
- The rules themselves are MCU dependent whereas the rule language infra-structur
-e is MCU independent.
- Peephole optimization rules for other MCU can be easily programmed using
- the rule language.
-\newline
+\layout Standard
-\newline
-The syntax for a rule is as follows:
-\layout Verse
+\size footnotesize
+LEFT_OP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-rule := replace [ restart ] '{' <assembly sequence> '
-\backslash
-n'
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- '}' by '{' '
-\backslash
-n'
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- <assembly sequence> '
-\backslash
-n'
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- '}' [if <functionName> ] '
-\backslash
-n'
\layout Standard
-<assembly sequence> := assembly instruction (each instruction including
- labels must be on a separate line).
-\newline
-
-\newline
-The optimizer will apply to the rules one by one from the top in the sequence
- of their appearance, it will terminate when all rules are exhausted.
- If the 'restart' option is specified, then the optimizer will start matching
- the rules again from the top, this option for a rule is expensive (performance)
-, it is intended to be used in situations where a transformation will trigger
- the same rule again.
- An example of this (not a good one, it has side effects) is the following
- rule:
-\layout Verse
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-replace restart {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-pop %1
-\newline
-\SpecialChar ~
-\SpecialChar ~
-push %1 } by {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-; nop
-\newline
-}
\layout Standard
-Note that the replace pattern cannot be a blank, but can be a comment line.
- Without the 'restart' option only the innermost 'pop' 'push' pair would
- be eliminated, i.e.:
-\layout Verse
+\size footnotesize
+Left shift
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-pop ar1
-\newline
-pop ar2
-\newline
-push ar2
-\newline
-push ar1
\layout Standard
-would result in:
-\layout Verse
+\size footnotesize
+IC_RESULT = IC_LEFT << IC_RIGHT
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-pop ar1
-\newline
-; nop
-\newline
-push ar1
\layout Standard
-\emph on
-with
-\emph default
- the restart option the rule will be applied again to the resulting code
- and then all the pop-push pairs will be eliminated to yield:
-\layout Verse
+\size footnotesize
+RIGHT_OP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\size footnotesize
+IC_LEFT() IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-; nop
-\newline
-; nop
\layout Standard
-A conditional function can be attached to a rule.
- Attaching rules are somewhat more involved, let me illustrate this with
- an example.
-\layout Verse
+\size footnotesize
+Right shift
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-replace {
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-ljmp %5
-\newline
-%2:
-\newline
-} by {
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-sjmp %5
-\newline
-%2:
-\newline
-} if labelInRange
\layout Standard
-The optimizer does a look-up of a function name table defined in function
-
-\emph on
-callFuncByName
-\emph default
- in the source file SDCCpeeph.c, with the name
-\emph on
-labelInRange
-\emph default
-.
- If it finds a corresponding entry the function is called.
- Note there can be no parameters specified for these functions, in this
- case the use of
-\emph on
-%5
-\emph default
- is crucial, since the function
-\emph on
-labelInRange
-\emph default
- expects to find the label in that particular variable (the hash table containin
-g the variable bindings is passed as a parameter).
- If you want to code more such functions, take a close look at the function
- labelInRange and the calling mechanism in source file SDCCpeeph.c.
- Currently implemented are
-\emph on
-labelInRange, labelRefCount, labelIsReturnOnly, operandsNotSame, xramMovcOption,
- 24bitMode, portIsDS390, 24bitModeAndPortDS390
-\emph default
-and
-\emph on
- notVolatile
-\emph default
-.
-\layout Standard
-I know this whole thing is a little kludgey, but maybe some day we will
- have some better means.
- If you are looking at this file, you will see the default rules that are
- compiled into the compiler, you can add your own rules in the default set
- there if you get tired of specifying the -
-\begin_inset ERT
-status Collapsed
+\size footnotesize
+IC_RESULT = IC_LEFT >> IC_RIGHT
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\size footnotesize
+GET_VALUE_
+\newline
+AT_ ADDRESS
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--peep-file option.
-\layout Section
+\layout Standard
-ANSI-Compliance
-\begin_inset LatexCommand \index{ANSI-compliance}
+\size footnotesize
+IC_LEFT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \label{sub:ANSI-Compliance}
+\size footnotesize
+Indirect fetch
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The latest publically available version of the standard
-\emph on
-ISO/IEC 9899 - Programming languages - C
-\emph default
- should be available at:
-\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
+\size footnotesize
+IC_RESULT = (*IC_LEFT);
\end_inset
-
-.
-\newline
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-Deviations from the compliance:
-\layout Itemize
-
-functions are not reentrant
-\begin_inset LatexCommand \index{reentrant}
+\size footnotesize
+POINTER_SET
\end_inset
-
- unless explicitly declared as such or the
-\series bold
--
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+
+\size footnotesize
+IC_RIGHT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+\size footnotesize
+Indirect set
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series default
- command line option is specified.
-\layout Itemize
-structures and unions cannot be assigned values directly, cannot be passed
- as function parameters or assigned to each other and cannot be a return
- value from a function, e.g.:
-\begin_deeper
-\layout Verse
+\size footnotesize
+(*IC_RESULT) = IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\family typewriter
-struct s { ...
- };
-\newline
-struct s s1, s2;
-\newline
-foo()
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-}
-\newline
-struct s foo1 (struct s parms) /* invalid in SDCC although allowed in ANSI
- */
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-struct s rets;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-return rets;/* is invalid in SDCC although allowed in ANSI */
-\newline
-}
-\end_deeper
-\layout Itemize
-initialization of structure arrays must be fully braced.
-\begin_deeper
-\layout Verse
+\size footnotesize
+'='
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-\family typewriter
-struct s { char x } a[] = {1, 2}; /* invalid in SDCC */
-\newline
-struct s { char x } a[] = {{1}, {2}}; /* OK */
-\end_deeper
-\layout Itemize
+\size footnotesize
+IC_RIGHT() IC_RESULT()
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-'long long
-\begin_inset LatexCommand \index{long long (not supported)}
+\layout Standard
+
+\size footnotesize
+Assignment
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-' (64 bit integers
-\begin_inset LatexCommand \index{int (64 bit) (not supported)}
+\layout Standard
+
+\size footnotesize
+IC_RESULT = IC_RIGHT;
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-) not supported.
-\layout Itemize
+\layout Standard
-'double
-\begin_inset LatexCommand \index{double (not supported)}
+\size footnotesize
+IFX
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-' precision floating point
-\begin_inset LatexCommand \index{Floating point support}
+\size footnotesize
+IC_COND IC_TRUE IC_LABEL
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-not supported.
-\layout Itemize
+\layout Standard
-Old K&R style
-\begin_inset LatexCommand \index{K\&R style}
+\size footnotesize
+Conditional jump.
+ If true label is present then jump to true label if condition is true else
+ jump to false label if condition is false
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- function declarations are NOT allowed.
-\begin_deeper
-\layout Verse
+\layout Standard
-\family typewriter
-foo(i,j) /* this old style of function declarations */
-\newline
-int i,j; /* are valid in ANSI but not valid in SDCC */
-\newline
-{
+\size footnotesize
+if (IC_COND) goto IC_TRUE;
\newline
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-...
-
+Or
\newline
-}
-\end_deeper
-\layout Itemize
-
-Most enhancements in C99 are not supported, f.e.:
-\begin_deeper
-\layout Verse
+If (!IC_COND) goto IC_FALSE;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\family typewriter
-\series bold
-inline
-\series default
- int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
- in C99 */
-\newline
-for (
-\series bold
-int
-\series default
- i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
-\end_deeper
-\layout Itemize
-Certain words that are valid identifiers in the standard may be reserved
- words in SDCC unless the
-\series bold
--
-\begin_inset ERT
-status Collapsed
+\size footnotesize
+ADDRESS_OF
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--std-c89
-\begin_inset LatexCommand \index{-\/-std-c89}
+\size footnotesize
+IC_LEFT() IC_RESULT()
\end_inset
-
- or -
-\begin_inset ERT
-status Collapsed
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--std-c99
-\begin_inset LatexCommand \index{-\/-std-c99}
+\size footnotesize
+Address of
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series default
- command line options are used.
- These may include (depending on the selected processor): 'at', 'banked',
- 'bit', 'code', 'critical', 'data', 'eeprom', 'far', 'flash', 'idata', 'interrup
-t', 'near', 'nonbanked', 'pdata', 'reentrant', 'sbit', 'sfr', 'shadowregs',
- 'sram', 'using', 'wparam', 'xdata', '_overlay', '_asm', '_endasm', and
- '_naked'.
- Compliant equivalents of these keywords are always available in a form
- that begin with two underscores
-\begin_inset LatexCommand \index{\_\_ (prefix for extended keywords)}
+\size footnotesize
+IC_RESULT = &IC_LEFT();
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-, f.e.
- '__data' instead of 'data'.
-\layout Section
+\layout Standard
-Cyclomatic Complexity
-\begin_inset LatexCommand \index{Cyclomatic complexity}
+\size footnotesize
+JUMPTABLE
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-Cyclomatic complexity of a function is defined as the number of independent
- paths the program can take during execution of the function.
- This is an important number since it defines the number test cases you
- have to generate to validate the function.
- The accepted industry standard for complexity number is 10, if the cyclomatic
- complexity reported by SDCC exceeds 10 you should think about simplification
- of the function logic.
- Note that the complexity level is not related to the number of lines of
- code in a function.
- Large functions can have low complexity, and small functions can have large
- complexity levels.
-
-\newline
-\newline
-SDCC uses the following formula to compute the complexity:
-\newline
+\size footnotesize
+IC_JTCOND IC_JTLABELS
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-complexity = (number of edges in control flow graph) - (number of nodes
- in control flow graph) + 2;
-\newline
-\newline
-Having said that the industry standard is 10, you should be aware that in
- some cases it be may unavoidable to have a complexity level of less than
- 10.
- For example if you have switch statement with more than 10 case labels,
- each case label adds one to the complexity level.
- The complexity level is by no means an absolute measure of the algorithmic
- complexity of the function, it does however provide a good starting point
- for which functions you might look at for further optimization.
-\layout Section
+\size footnotesize
+Jump to list of labels depending on the value of JTCOND
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Retargetting for other Processors
\layout Standard
-The issues for retargetting the compiler are far too numerous to be covered
- by this document.
- What follows is a brief description of each of the seven phases of the
- compiler and its MCU dependency.
-\layout Itemize
-
-Parsing the source and building the annotated parse tree.
- This phase is largely MCU independent (except for the language extensions).
- Syntax & semantic checks are also done in this phase, along with some initial
- optimizations like back patching labels and the pattern matching optimizations
- like bit-rotation etc.
-\layout Itemize
-The second phase involves generating an intermediate code which can be easy
- manipulated during the later phases.
- This phase is entirely MCU independent.
- The intermediate code generation assumes the target machine has unlimited
- number of registers, and designates them with the name iTemp.
- The compiler can be made to dump a human readable form of the code generated
- by using the -
-\begin_inset ERT
-status Collapsed
+\size footnotesize
+Switch statement
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\end_inset
-
--dumpraw option.
-\layout Itemize
-This phase does the bulk of the standard optimizations and is also MCU independe
-nt.
- This phase can be broken down into several sub-phases:
-\newline
+\size footnotesize
+CAST
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-Break down intermediate code (iCode) into basic blocks.
-\newline
-Do control flow & data flow analysis on the basic blocks.
-\newline
-Do local common subexpression elimination, then global subexpression elimination
-\newline
-Dead code elimination
-\newline
-Loop optimizations
-\newline
-If loop optimizations caused any changes then do 'global subexpression eliminati
-on' and 'dead code elimination' again.
-\layout Itemize
+\layout Standard
-This phase determines the live-ranges; by live range I mean those iTemp
- variables defined by the compiler that still survive after all the optimization
-s.
- Live range analysis
-\begin_inset LatexCommand \index{Live range analysis}
+\size footnotesize
+IC_RIGHT() IC_LEFT() IC_RESULT()
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- is essential for register allocation, since these computation determines
- which of these iTemps will be assigned to registers, and for how long.
-\layout Itemize
+\layout Standard
-Phase five is register allocation.
- There are two parts to this process.
-\newline
-\newline
-The first part I call 'register packing' (for lack of a better term).
- In this case several MCU specific expression folding is done to reduce
- register pressure.
-\newline
+\size footnotesize
+Cast types
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-The second part is more MCU independent and deals with allocating registers
- to the remaining live ranges.
- A lot of MCU specific code does creep into this phase because of the limited
- number of index registers available in the 8051.
-\layout Itemize
+\layout Standard
-The Code generation phase is (unhappily), entirely MCU dependent and very
- little (if any at all) of this code can be reused for other MCU.
- However the scheme for allocating a homogenized assembler operand for each
- iCode operand may be reused.
-\layout Itemize
-As mentioned in the optimization section the peep-hole optimizer is rule
- based system, which can reprogrammed for other MCUs.
-\layout Chapter
+\size footnotesize
+IC_RESULT = (typeof IC_LEFT) IC_RIGHT;
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Compiler internals
-\begin_inset LatexCommand \index{Compiler internals}
+\layout Standard
-\end_inset
+\size footnotesize
+SEND
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\layout Section
+\layout Standard
-The anatomy of the compiler
-\begin_inset LatexCommand \label{sub:The-anatomy-of}
+\size footnotesize
+IC_LEFT()
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\shape italic
-This is an excerpt from an article published in Circuit Cellar Magazine
- in
-\series bold
-August 2000
-\series default
-.
- It's a little outdated (the compiler is much more efficient now and user/develo
-per friendly), but pretty well exposes the guts of it all.
-\shape default
-
+\size footnotesize
+This is used for passing parameters in registers;
\newline
+move IC_LEFT to the next available parameter register.
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-The current version of SDCC can generate code for Intel 8051 and Z80 MCU.
- It is fairly easy to retarget for other 8-bit MCU.
- Here we take a look at some of the internals of the compiler.
-
-\layout Paragraph*
+\layout Standard
-Parsing
-\begin_inset LatexCommand \index{Parsing}
+\size footnotesize
+None
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-
\layout Standard
-Parsing the input source file and creating an AST (Annotated Syntax Tree
-\begin_inset LatexCommand \index{Annotated syntax tree}
+\size footnotesize
+RECV
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-).
- This phase also involves propagating types (annotating each node of the
- parse tree with type information) and semantic analysis.
- There are some MCU specific parsing rules.
- For example the storage classes, the extended storage classes are MCU specific
- while there may be a xdata storage class for 8051 there is no such storage
- class for z80 or Atmel AVR.
- SDCC allows MCU specific storage class extensions, i.e.
- xdata will be treated as a storage class specifier when parsing 8051 C
- code but will be treated as a C identifier when parsing z80 or ATMEL AVR
- C code.
-\layout Paragraph*
+\layout Standard
-Generating iCode
-\begin_inset LatexCommand \index{iCode}
+\size footnotesize
+IC_RESULT()
\end_inset
-
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-Intermediate code generation.
- In this phase the AST is broken down into three-operand form (iCode).
- These three operand forms are represented as doubly linked lists.
- ICode is the term given to the intermediate form generated by the compiler.
- ICode example section shows some examples of iCode generated for some simple
- C source functions.
-\layout Paragraph*
-
-Optimizations
-\begin_inset LatexCommand \index{Optimizations}
+\size footnotesize
+This is used for receiving parameters passed in registers;
+\newline
+Move the values in the next parameter register to IC_RESULT
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-.
\layout Standard
-Bulk of the target independent optimizations is performed in this phase.
- The optimizations include constant propagation, common sub-expression eliminati
-on, loop invariant code movement, strength reduction of loop induction variables
- and dead-code elimination.
-\layout Paragraph*
-
-Live range analysis
-\begin_inset LatexCommand \index{Live range analysis}
+\size footnotesize
+None
\end_inset
-
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-During intermediate code generation phase, the compiler assumes the target
- machine has infinite number of registers and generates a lot of temporary
- variables.
- The live range computation determines the lifetime of each of these compiler-ge
-nerated temporaries.
- A picture speaks a thousand words.
- ICode example sections show the live range annotations for each of the
- operand.
- It is important to note here, each iCode is assigned a number in the order
- of its execution in the function.
- The live ranges are computed in terms of these numbers.
- The from number is the number of the iCode which first defines the operand
- and the to number signifies the iCode which uses this operand last.
-\layout Paragraph*
-Register Allocation
-\begin_inset LatexCommand \index{Register allocation}
+\shape slanted
+\size footnotesize
+(some more have been added)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-The register allocation determines the type and number of registers needed
- by each operand.
- In most MCUs only a few registers can be used for indirect addressing.
- In case of 8051 for example the registers R0 & R1 can be used to indirectly
- address the internal ram and DPTR to indirectly address the external ram.
- The compiler will try to allocate the appropriate register to pointer variables
- if it can.
- ICode example section shows the operands annotated with the registers assigned
- to them.
- The compiler will try to keep operands in registers as much as possible;
- there are several schemes the compiler uses to do achieve this.
- When the compiler runs out of registers the compiler will check to see
- if there are any live operands which is not used or defined in the current
- basic block being processed, if there are any found then it will push that
- operand and use the registers in this block, the operand will then be popped
- at the end of the basic block.
+
+\shape slanted
+\size footnotesize
+see f.e.
-\layout Standard
+\family typewriter
+gen51Code()
+\family default
+ in
+\family typewriter
+src/mcs51/gen.c
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
-There are other MCU specific considerations in this phase.
- Some MCUs have an accumulator; very short-lived operands could be assigned
- to the accumulator instead of a general-purpose register.
-\layout Paragraph*
-Code generation
\layout Standard
-Figure II gives a table of iCode operations supported by the compiler.
- The code generation involves translating these operations into corresponding
- assembly code for the processor.
- This sounds overly simple but that is the essence of code generation.
- Some of the iCode operations are generated on a MCU specific manner for
- example, the z80 port does not use registers to pass parameters so the
- SEND and RECV iCode operations will not be generated, and it also does
- not support JUMPTABLES.
-
-\newline
-\series bold
-\shape italic
-\color red
-<Where is Figure II?>
-\layout Comment
+\begin_inset Note
+collapsed true
+
+\layout Standard
In the original article Figure II was announced to be downloadable on
\shape italic
Circuit Cellar
\shape default
's web site.
- Unfortunately it never seemed to have shown up there, so: where is Figure
- II?
+ ftp://ftp.circuitcellar.com/pub/Circuit_Cellar/2000/121/dutta.ZIP
+\end_inset
+
+
\layout Paragraph*
ICode Example
\newline
+\newline
+
+\emph on
+Also thanks to Sourceforge
+\begin_inset LatexCommand \url{http://www.sf.net}
+
+\end_inset
+
+ which has hosted the project since 1999 and donates significant download
+ bandwidth and probably more than
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+$10^{13}$
+\end_inset
+
+CPU cycles per day.
+\newline
+
+\begin_inset Note
+collapsed false
+
+\layout Standard
+
+more than 10^13 is an estimate: on my Athlon 2800+ it takes about (0.5+6.5+20)
+ minutes for (configure+make+regression test), and there is (i386, amd64,
+ alpha, ppc64, (mingw32), sparc, macosx).
+
+\end_inset
+
+
\layout Standard
This document was initially written by Sandeep Dutta
projects / fw / sdcc / blobdiff