-#LyX 1.2 created this file. For more info see http://www.lyx.org/
-\lyxformat 220
-\textclass article
+#LyX 1.3 created this file. For more info see http://www.lyx.org/
+\lyxformat 221
+\textclass book
+\begin_preamble
+\usepackage[
+ pdftitle={SDCC Compiler User Guide},
+ pdfauthor={SDCC development team},
+ pdfsubject={installation, user manual},
+ pdfkeywords={8032, 8051, ansi, c, compiler, CPU, DS390,
+ embedded, GPL, HC08, manual, mcs51, PIC, Z80},
+ colorlinks=true,
+ linkcolor=blue] {hyperref}
+%
+\sloppy
+\tolerance=500
+\emergencystretch=30pt
+%
+\date{}
+\end_preamble
\language english
\inputencoding default
\fontscheme pslatex
\graphics default
\paperfontsize default
\spacing single
-\papersize Default
+\papersize letterpaper
\paperpackage a4
-\use_geometry 0
+\use_geometry 1
\use_amsmath 0
\use_natbib 0
\use_numerical_citations 0
\paperorientation portrait
+\leftmargin 30mm
+\topmargin 20mm
+\rightmargin 25mm
+\bottommargin 20mm
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\layout Comment
Please note: double dashed longoptions (e.g.
- --version) need three dashes in this document to be visable in html and
- pdf output.
+ --version) are written this way: -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-
+\layout Comment
+
+Two resp.
+ three consecutive dashes simply result in a long resp.
+ extra long dash.
+\layout Comment
+
+Architecture specific stuff (like memory models, code examples) should maybe
+ later go
+\layout Comment
+
+into seperate sections/chapters/appendices (it is hard to document PIC or
+ Z80 in
+\layout Comment
+
+a 8051 centered document) - for now simply add.
\layout Title
SDCC Compiler User Guide
+\layout Date
+
+
+\size normal
+SDCC 2.4.0
+\size footnotesize
+
+\newline
+$Date$
+\newline
+$Revision$
+\layout Comment
+
+The above strings enclosed in $ are automatically updated by cvs
\layout Standard
\end_inset
-\layout Section
+\layout Chapter
Introduction
-\layout Subsection
+\layout Section
About SDCC
\layout Standard
\series bold
SDCC
\series default
- is a Freeware, retargettable, optimizing ANSI-C compiler by
+ (
+\emph on
+S
+\emph default
+mall
+\emph on
+D
+\emph default
+evice
+\emph on
+C
+\emph default
+
+\emph on
+C
+\emph default
+ompiler) is a Freeware, retargettable, optimizing ANSI-C compiler by
\series bold
Sandeep Dutta
\series default
designed for 8 bit Microprocessors.
- The current version targets Intel MCS51 based Microprocessors(8051,8052,
- etc), Zilog Z80 based MCUs, and the Dallas DS80C390 variant.
- It can be retargetted for other microprocessors, support for PIC, AVR and
- 186 is under development.
+ The current version targets Intel MCS51 based Microprocessors (8031, 8032,
+ 8051, 8052
+\begin_inset LatexCommand \index{8031, 8032, 8051, 8052, mcs51 CPU}
+
+\end_inset
+
+, etc.), Dallas DS80C390 variants, Motorola HC08 and Zilog Z80 based MCUs.
+ It can be retargetted 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 & ASLINK, a Freeware, retargettable assembler & linker.
SDCC has extensive language extensions suitable for utilizing various microcont
dead code elimination
\layout Itemize
-jumptables for
+jump tables for
\emph on
switch
\emph default
\newline
\newline
-SDCC also provides an option (--cyclomatic) to report the relative complexity
- of a function.
+SDCC also provides an option (-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-cyclomatic) to report the relative complexity of a function.
These functions can then be further optimized, or hand coded in assembly
if needed.
\newline
The latest version can be downloaded from
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/}
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
\end_inset
+.
\series bold
+
+\series default
+\emph on
+Please note: the compiler will probably always be some steps ahead of this
+ documentation
+\series bold
+\emph default
+
+\begin_inset LatexCommand \index{Status of documentation}
+
+\end_inset
+
+
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+Obviously this has pros and cons
+\end_inset
+
.
-\layout Subsection
+\layout Section
Open Source
\layout Standard
This documentation is maintained using a freeware word processor (LyX).
\newline
This program is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the Free
- Software Foundation; either version 2, or (at your option) any later version.
+ under the terms of the GNU General Public License
+\begin_inset LatexCommand \index{GNU General Public License, GPL}
+
+\end_inset
+
+ as published by the Free Software Foundation; either version 2, or (at
+ your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- FOR A PARTICULAR PURPOSE.
+ ANY WARRANTY; without even the implied warranty
+\begin_inset LatexCommand \index{warranty}
+
+\end_inset
+
+ of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, 59 Temple
You are forbidden to forbid anyone else to use, share and improve what
you give them.
Help stamp out software-hoarding!
-\layout Subsection
+\layout Section
Typographic conventions
+\begin_inset LatexCommand \index{Typographic conventions}
+
+\end_inset
+
+
\layout Standard
Throughout this manual, we will use the following convention.
Interesting items and new terms are printed in
\emph on
italic.
-\layout Subsection
+\layout Section
Compatibility with previous versions
\layout Standard
This version has numerous bug fixes compared with the previous version.
But we also introduced some incompatibilities with older versions.
Not just for the fun of it, but to make the compiler more stable, efficient
- and ANSI compliant.
+ and ANSI compliant
+\begin_inset LatexCommand \index{ANSI-compliance}
+
+\end_inset
+
+ (see section
+\begin_inset LatexCommand \ref{sub:ANSI-Compliance}
+
+\end_inset
+
+ for ANSI-Compliance).
\newline
(8 bits) which is not ANSI compliant
\layout Itemize
-the default directory for gcc-builds where include, library and documention
+the default directory for gcc-builds where include, library and documentation
files are stored is now in /usr/local/share
\layout Itemize
will push a as an int and as a char resp.
\layout Itemize
-option ---regextend has been removed
+option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-regextend has been removed
\layout Itemize
-option ---noregparms has been removed
+option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-noregparms has been removed
\layout Itemize
-option ---stack-after-data has been removed
+option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-after-data has been removed
\layout Standard
\emph on
<pending: more incompatibilities?>
-\layout Subsection
+\layout Section
System Requirements
\layout Standard
For Windows some pre-compiled binary distributions are available for your
convenience.
You should have some experience with command line tools and compiler use.
-\layout Subsection
+\layout Section
Other Resources
\layout Standard
their own documentation and can be found in the source distribution.
If you want the latest unreleased software, the complete source package
is available directly by anonymous CVS on cvs.sdcc.sourceforge.net.
-\layout Subsection
+\layout Section
Wishes for the future
\layout Standard
char KernelFunction3(char p) at 0x340;
\newline
-\newline
+\layout Standard
-\family default
-If you can think of some more, please send them to the list.
+
+\family typewriter
+code banking
+\begin_inset LatexCommand \index{code banking (not supported)}
+
+\end_inset
+
+ support for mcs51
\newline
\newline
-\emph on
-<pending: And then of course a proper index-table
-\begin_inset LatexCommand \index{index}
+\family default
+If you can think of some more, please see the section
+\begin_inset LatexCommand \ref{sub:Requesting-Features}
\end_inset
->
-\layout Section
+ about filing feature requests
+\begin_inset LatexCommand \index{Requesting features}
-Installation
-\layout Subsection
+\end_inset
-Install and search paths
-\layout Standard
-Linux (and other gcc-builds like Solaris, Cygwin, Mingw32 and OSX) by default
- install in /usr/local.
- You can override this when configuring with ---prefix-path.
- Subdirs used will be bin, share/sdcc/include, share/sdcc/lib and share/sdcc/doc.
-\newline
-Windows MSVC and Borland builds will install in one single tree (e.g.
- /sdcc) with subdirs bin, lib, include and doc.
-\newline
+\begin_inset LatexCommand \index{Feature request}
-\newline
-The paths searched when running the compiler are as follows (the first catch
- wins):
-\layout Enumerate
+\end_inset
-Binary files (preprocessor, assembler and linker):
-\newline
-- the path of argv[0] (if available)
+.
\newline
-- getenv(
-\begin_inset Quotes sld
-\end_inset
-SDCC_BIN_PATH
-\begin_inset Quotes srd
-\end_inset
+\layout Chapter
-)
-\newline
-- getenv(
-\begin_inset Quotes sld
-\end_inset
+Installing SDCC
+\begin_inset LatexCommand \index{Installation}
-SDCCHOME
-\begin_inset Quotes srd
\end_inset
-)/bin
-\newline
-- $PATH
-\layout Enumerate
-Include files:
-\newline
-- -I dir
-\newline
-- getenv(
-\begin_inset Quotes sld
-\end_inset
+\layout Standard
-SDCC_INCLUDE_PATH
-\begin_inset Quotes srd
-\end_inset
+For most users it is sufficient to skip to either section
+\begin_inset LatexCommand \ref{sub:Building-SDCC-on-Linux}
-)
-\newline
-- getenv(
-\begin_inset Quotes sld
\end_inset
-SDCCHOME
-\begin_inset Quotes srd
+ or section
+\begin_inset LatexCommand \ref{sub:Windows-Install}
+
\end_inset
-)/include
-\newline
-- /usr/local/share/sdcc/include (gcc builds)
-\newline
-- path(arv[0])/../include and then /sdcc/include (as a last resort for windoze
- msvc and borland builds)
-\layout Enumerate
+.
+ More detailled instructions follow below.
+\layout Section
-Library files (the
-\shape italic
-model
-\shape default
- is auto-appended by the compiler, e.g.
- small, large, z80, ds390 etc.):
-\newline
-- -L dir
-\newline
-- getenv(
-\begin_inset Quotes sld
-\end_inset
+Configure Options
+\begin_inset LatexCommand \index{Options SDCC configuration}
-SDCC_LIB_PATH
-\begin_inset Quotes srd
\end_inset
-)/
-\shape italic
-model
-\shape default
-\newline
-- getenv(
-\begin_inset Quotes sld
-\end_inset
+\layout Standard
-SDCCHOME
-\begin_inset Quotes srd
-\end_inset
+The install paths, search paths and other options are defined when running
+ 'configure'.
+ The defaults can be overridden by:
+\layout List
+\labelwidthstring 00.00.0000
-)/lib/
-\shape italic
-model
-\shape default
+-
+\begin_inset ERT
+status Collapsed
-\newline
-- /usr/local/share/sdcc/lib/
-\shape italic
-model
-\shape default
- (gcc builds)
-\newline
-- path(argv[0])/../lib/
-\shape italic
-model
-\shape default
- and then /sdcc/lib/
-\shape italic
-model
-\shape default
- (as a last resort for windoze msvc and borland builds)
-\layout Enumerate
+\layout Standard
-Documentation (although never really searched for, you have to do that yourself
- :):
-\newline
-- getenv(
-\begin_inset Quotes sld
+\backslash
+/
\end_inset
-SDCCHOME
-\begin_inset Quotes srd
+-prefix see table below
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
\end_inset
-)/doc
-\newline
-- /usr/local/share/sdcc/doc (gcc builds)
-\newline
-- /sdcc/doc (windoze msvc and borland builds)
+-exec_prefix see table below
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
\layout Standard
-So, for windoze it is highly recommended to set the environment variable
- SDCCHOME to prevent needless usage of -I and -L options.
- For gcc-builds SDCCHOME should only be set when sdcc is installed in non-standa
-rd paths.
-\layout Subsection
+\backslash
+/
+\end_inset
-Linux and other gcc-based systems (cygwin, mingw32, osx)
-\layout Enumerate
+-bindir see table below
+\layout List
+\labelwidthstring 00.00.0000
+-
+\begin_inset ERT
+status Collapsed
-\series medium
-Download the source package
-\series default
- either from the SDCC CVS repository or from the
-\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
+\layout Standard
+\backslash
+/
\end_inset
+-datadir see table below
+\layout List
+\labelwidthstring 00.00.0000
-\series medium
-, it will be named something like sdcc
-\series default
-.src
-\series medium
-.tgz.
-\layout Enumerate
+docdir environment variable, see table below
+\layout List
+\labelwidthstring 00.00.0000
+include_dir_suffix environment variable, see table below
+\layout List
+\labelwidthstring 00.00.0000
-\series medium
-Bring up a command line terminal, such as xterm.
-\layout Enumerate
+lib_dir_suffix environment variable, see table below
+\layout List
+\labelwidthstring 00.00.0000
+sdccconf_h_dir_separator environment variable, either / or
+\backslash
-\series medium
-Unpack the file using a command like:
-\family sans
-\series bold
-"tar -xzf sdcc.src.tgz
-\family default
-\series default
-"
-\series medium
-, this will create a sub-directory called sdcc with all of the sources.
-\layout Enumerate
-
-Change directory into the main SDCC directory, for example type:
-\family sans
-\series bold
-"cd sdcc
-\series default
-".
-\layout Enumerate
+\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.
+\layout List
+\labelwidthstring 00.00.0000
+-
+\begin_inset ERT
+status Collapsed
-\series medium
-Type
-\family sans
-\series bold
-"./configure
-\family default
-\series default
-".
- This configures the package for compilation on your system.
-\layout Enumerate
+\layout Standard
+\backslash
+/
+\end_inset
-\series medium
-Type
-\family sans
-\series bold
-"make
-\family default
-\series default
-"
-\series medium
-.
+-disable-mcs51-port Excludes the Intel mcs51 port
+\layout List
+\labelwidthstring 00.00.0000
-\series default
- All of the source packages will compile, this can take a while.
-\layout Enumerate
+-
+\begin_inset ERT
+status Collapsed
+\layout Standard
-\series medium
-Type
-\family sans
-\series bold
-"make install"
-\family default
-\series default
- as root
-\series medium
-.
+\backslash
+/
+\end_inset
-\series default
- This copies the binary executables, the include files, the libraries and
- the documentation to the install directories.
-\layout Subsection
+-disable-gbz80-port Excludes the Gameboy gbz80 port
+\layout List
+\labelwidthstring 00.00.0000
-Windows
-\layout Subsubsection
+-
+\begin_inset ERT
+status Collapsed
-Windows Install Using a Binary Package
-\layout Enumerate
+\layout Standard
-Download the binary package and unpack it using your favorite unpacking
- tool (gunzip, WinZip, etc).
- This should unpack to a group of sub-directories.
- An example directory structure after unpacking the mingw32 package is:
- c:
-\backslash
-usr
-\backslash
-local
-\backslash
-bin for the executables, c:
\backslash
-usr
-\backslash
-local
-\backslash
-share
-\backslash
-sdcc
-\backslash
-include and c:
-\backslash
-usr
-\backslash
-local
-\backslash
-share
+/
+\end_inset
+
+-disable-z80-port Excludes the z80 port
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
\backslash
-sdcc
+/
+\end_inset
+
+-disable-avr-port Excludes the AVR port
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
\backslash
-lib for the include and libraries.
-\layout Enumerate
+/
+\end_inset
-Adjust your environment variable PATH to include the location of the bin
- directory or start sdcc using the full path.
-\layout Subsubsection
+-disable-ds390-port Excludes the DS390 port
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
-Windows Install Using Cygwin and Mingw32
\layout Standard
-Follow the instruction in
-\series bold
-Linux and other gcc-based systems
-\series default
-.
-\layout Subsubsection
+\backslash
+/
+\end_inset
+
+-disable-hc08-port Excludes the HC08 port
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
-Windows Install Using Microsoft Visual C++ 6.0/NET
\layout Standard
+\backslash
+/
+\end_inset
-\series medium
-Download the source package
-\series default
- either from the SDCC CVS repository or from the
-\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
+-disable-pic-port Excludes the PIC port
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+\backslash
+/
\end_inset
+-disable-xa51-port Excludes the XA51 port
+\layout List
+\labelwidthstring 00.00.0000
-\series medium
-, it will be named something like sdcc
-\series default
-.src
-\series medium
-.tgz.
+-
+\begin_inset ERT
+status Collapsed
+
+\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.
- The workspace name is 'sdcc.dsw'.
- Please note that as it is now, all the executables are created in a folder
- called sdcc
\backslash
-bin_vc.
- Once built you need to copy the executables from sdcc
+/
+\end_inset
+
+-disable-ucsim Disables configuring and building of ucsim
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
\backslash
-bin_vc to sdcc
+/
+\end_inset
+
+-disable-device-lib-build Disables automatically building device libraries
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
\backslash
-bin before runnng SDCC.
-
-\newline
+/
+\end_inset
-\newline
-In order to build SDCC with Visual C++ 6.0/NET you need win32 executables
- of bison.exe, flex.exe, and gawk.exe.
- One good place to get them is
-\begin_inset LatexCommand \url[here]{http://unxutils.sourceforge.net}
+-disable-packihx Disables building packihx
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+\layout Standard
+
+\backslash
+/
\end_inset
+-enable-libgc Use the Bohem memory allocator.
+ Lower runtime footprint.
+\layout Standard
-\newline
+Furthermore the environment variables CC, CFLAGS, ...
+ the tools and their arguments can be influenced.
+ Please see `configure -
+\begin_inset ERT
+status Collapsed
-\newline
-Download the file UnxUtils.zip.
- Now you have to install the utilities and setup Visual C++ so it can locate
- the required programs.
- Here there are two alternatives (choose one!):
-\layout Enumerate
+\layout Standard
-The easy way:
+\backslash
+/
+\end_inset
+
+-help` and the man/info pages of `configure` for details.
\newline
\newline
-a) Extract UnxUtils.zip to your C:
-\backslash
- hard disk PRESERVING the original paths, otherwise bison won't work.
- (If you are using WinZip make certain that 'Use folder names' is selected)
+The names of the standard libraries STD_LIB, STD_INT_LIB, STD_LONG_LIB,
+ STD_FP_LIB, STD_DS390_LIB, STD_XA51_LIB and the environment variables SDCC_DIR_
+NAME, SDCC_INCLUDE_NAME, SDCC_LIB_NAME are defined by `configure` too.
+ At the moment it's not possible to change the default settings (it was
+ simply never required).
\newline
\newline
-b) In the Visual C++ IDE click Tools, Options, select the Directory tab,
- in 'Show directories for:' select 'Executable files', and in the directories
- window add a new path: 'C:
-\backslash
-user
-\backslash
-local
-\backslash
-wbin', click ok.
+These configure options are compiled into the binaries, and can only be
+ changed by rerunning 'configure' and recompiling SDCC.
+ The configure options are written in
+\emph on
+italics
+\emph default
+ to distinguish them from run time environment variables (see section search
+ paths).
\newline
\newline
-(As a side effect, you get a bunch of Unix utilities that could be useful,
- such as diff and patch.)
+The settings for
+\begin_inset Quotes sld
+\end_inset
+
+Win32 builds
+\begin_inset Quotes srd
+\end_inset
+
+ are used by the SDCC team to build the official Win32 binaries.
+ The SDCC team uses Mingw32 to build the official Windows binaries, because
+ it's
\layout Enumerate
-A more compact way:
-\newline
+open source,
+\layout Enumerate
-\newline
-This one avoids extracting a bunch of files you may not use, but requires
- some extra work:
-\newline
+a gcc compiler and last but not least
+\layout Enumerate
-\newline
-a) Create a directory were to put the tools needed, or use a directory already
- present.
- Say for example 'C:
-\backslash
-util'.
-\newline
+the binaries can be built by cross compiling on Sourceforge's compile farm.
+\layout Standard
-\newline
-b) Extract 'bison.exe', 'bison.hairy', 'bison.simple', 'flex.exe', and gawk.exe
- to such directory WITHOUT preserving the original paths.
- (If you are using WinZip make certain that 'Use folder names' is not selected)
+See the examples, how to pass the Win32 settings to 'configure'.
+ The other Win32 builds using Borland, VC or whatever don't use 'configure',
+ but a header file sdcc_vc_in.h is the same as sdccconf.h built by 'configure'
+ for Win32.
\newline
\newline
-c) Rename bison.exe to '_bison.exe'.
+These defaults are:
\newline
-\newline
-d) Create a batch file 'bison.bat' in 'C:
-\backslash
-util
-\backslash
-' and add these lines:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-set BISON_SIMPLE=C:
-\backslash
-util
-\backslash
-bison.simple
-\newline
-\SpecialChar ~
-\SpecialChar ~
-set BISON_HAIRY=C:
-\backslash
-util
-\backslash
-bison.hairy
-\newline
-\SpecialChar ~
-\SpecialChar ~
-_bison %1 %2 %3 %4 %5 %6 %7 %8 %9
-\newline
+\layout Standard
+\align center
-\newline
-Steps 'c' and 'd' are needed because bison requires by default that the
- files 'bison.simple' and 'bison.hairy' reside in some weird Unix directory,
- '/usr/local/share/' I think.
- So it is necessary to tell bison where those files are located if they
- are not in such directory.
- That is the function of the environment variables BISON_SIMPLE and BISON_HAIRY.
-\newline
+\begin_inset Tabular
+<lyxtabular version="3" rows="8" columns="3">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-e) In the Visual C++ IDE click Tools, Options, select the Directory tab,
- in 'Show directories for:' select 'Executable files', and in the directories
- window add a new path: 'c:
-\backslash
-util', click ok.
- Note that you can use any other path instead of 'c:
-\backslash
-util', even the path where the Visual C++ tools are, probably: 'C:
-\backslash
-Program Files
-\backslash
-Microsoft Visual Studio
-\backslash
-Common
-\backslash
-Tools'.
- So you don't have to execute step 'e' :)
\layout Standard
-That is it.
- Open 'sdcc.dsw' in Visual Studio, click 'build all', when it finishes copy
- the executables from sdcc
-\backslash
-bin_vc to sdcc
-\backslash
-bin, and you can compile using sdcc.
-\layout Subsubsection
+Variable
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Windows Install Using Borland
-\layout Enumerate
+\layout Standard
-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++).
-\layout Enumerate
+default
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-If you modify any source files and need to rebuild, be aware that the dependanci
-es may not be correctly calculated.
- The safest option is to delete all .obj files and run the build again.
- From a Cygwin BASH prompt, this can easily be done with the commmand:
-\newline
+\layout Standard
-\newline
+Win32 builds
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family sans
-\series bold
-find .
-
-\backslash
-( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
-\backslash
-) -print -exec rm {}
-\backslash
-;
-\family default
-\series default
+\layout Standard
-\newline
-\newline
-or on Windows NT/2000/XP from the command prompt with the commmand:
-\newline
+\emph on
+PREFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family sans
-\series bold
+\layout Standard
-\newline
-del /s *.obj *.lib *.rul
-\family default
-\series default
- from the sdcc directory.
-\layout Subsection
+/usr/local
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Testing out the SDCC Compiler
\layout Standard
-The first thing you should do after installing your SDCC compiler is to
- see if it runs.
- Type
-\family sans
-\series bold
-"sdcc ---version"
-\family default
-\series default
- at the prompt, and the program should run and tell you the version.
- If it doesn't run, or gives a message about not finding sdcc program, then
- you need to check over your installation.
- Make sure that the sdcc bin directory is in your executable search path
- defined by the PATH environment setting (see the Trouble-shooting section
- for suggestions).
- Make sure that the sdcc program is in the bin folder, if not perhaps something
- did not install correctly.
-\newline
-
-\newline
-\series medium
-SDCC
-\series default
-is commonly installed as described in section
-\begin_inset Quotes sld
+\backslash
+sdcc
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Install and search paths
-\begin_inset Quotes srd
+\layout Standard
+
+
+\emph on
+EXEC_PREFIX
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\newline
-\newline
+\emph on
+$PREFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\series medium
-Make sure the compiler works on a very simple example.
- Type in the following test.c program using your favorite
-\series default
-ascii
-\series medium
-editor:
-\series default
+\layout Standard
-\newline
-\family typewriter
+\emph on
+$PREFIX
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-char test;
-\newline
+\layout Standard
-\newline
-void main(void) {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-test=0;
-\newline
-}
-\family default
-\newline
+\emph on
+BINDIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
\emph on
+$EXECPREFIX
+\emph default
+/bin
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\series medium
+
+\emph on
+$EXECPREFIX
\emph default
-Compile this using the following command:
-\family sans
-\series bold
-"sdcc -c test.c".
-\family default
-\series default
-
-\series medium
-If all goes well, the compiler will generate a test.asm and test.rel file.
- Congratulations, you've just compiled your first program with SDCC.
- We used the -c option to tell SDCC not to link the generated code, just
- to keep things simple for this step.
-\series default
+\backslash
+bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\newline
-\series medium
-The next step is to try it with the linker.
- Type in
-\family sans
-\series bold
-"sdcc test.c
-\family default
-\series default
-"
-\series medium
-.
- If all goes well the compiler will link with the libraries and produce
- a test.ihx output file.
- If this step fails
-\series default
-
-\series medium
-(no test.ihx, and the linker generates warnings), then the problem is most
- likely that sdcc cannot find the
-\series default
-/
-\series medium
-usr/local/share/sdcc/lib directory
-\series default
-
-\series medium
-(see the Install trouble-shooting section for suggestions).
-\series default
-
-\newline
-
-\newline
-
-\series medium
-The final test is to ensure sdcc can use the
-\series default
-standard
-\series medium
- header files and libraries.
- Edit test.c and change it to the following:
-\series default
-
-\newline
-
-\newline
+\emph on
+DATADIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-#include <string.h>
-\newline
+\layout Standard
-\newline
-char str1[10];
-\newline
-\newline
-void main(void) {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-strcpy(str1, "testing");
-\newline
-}
-\newline
+\emph on
+$PREFIX
+\emph default
+/share
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family default
-\series medium
-Compile this by typing
-\family sans
-\series bold
-"sdcc test.c"
-\family default
-\series medium
-.
- This should generate a test.ihx output file, and it should give no warnings
- such as not finding the string.h file.
- If it cannot find the string.h file, then the problem is that sdcc cannot
- find the /usr/local/share/sdcc/include directory
-\series default
-
-\series medium
-(see the Install trouble-shooting section for suggestions).
-\layout Subsection
-Install Trouble-shooting
-\layout Subsubsection
+\emph on
+$PREFIX
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-SDCC does not build correctly.
\layout Standard
-A thing to try is starting from scratch by unpacking the .tgz source package
- again in an empty directory.
- Confure it like:
-\newline
-
-\newline
-
-\family sans
-\series bold
-./configure 2>&1 | tee configure.log
-\family default
-\series default
-\newline
+\emph on
+DOCDIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-and build it like:
-\newline
+\layout Standard
-\newline
-\family sans
-\series bold
-make 2>&1 | tee make.log
-\family default
-\series default
+\emph on
+$DATADIR
+\emph default
+/sdcc/doc
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\newline
-If anything goes wrong, you can review the log files to locate the problem.
- Or a relevant part of this can be attached to an email that could be helpful
- when requesting help from the mailing list.
-\layout Subsubsection
-What the
-\begin_inset Quotes sld
-\end_inset
+\emph on
+$DATADIR
+\emph default
-./configure
-\begin_inset Quotes srd
+\backslash
+doc
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- does
\layout Standard
-The
-\begin_inset Quotes sld
-\end_inset
-./configure
-\begin_inset Quotes srd
+\emph on
+INCLUDE_DIR_SUFFIX
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- command is a script that analyzes your system and performs some configuration
- to ensure the source package compiles on your system.
- It will take a few minutes to run, and will compile a few tests to determine
- what compiler features are installed.
-\layout Subsubsection
+\layout Standard
-What the
-\begin_inset Quotes sld
+sdcc/include
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-make
-\begin_inset Quotes srd
+\layout Standard
+
+include
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- does.
\layout Standard
-This runs the GNU make tool, which automatically compiles all the source
- packages into the final installed binary executables.
-\layout Subsubsection
-What the
-\begin_inset Quotes sld
+\emph on
+LIB_DIR_SUFFIX
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-make install
-\begin_inset Quotes erd
+\layout Standard
+
+sdcc/lib
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- command does.
\layout Standard
-This will install the compiler, other executables libraries and include
- files in to the appropriate directories.
- See section
-\begin_inset Quotes sld
+lib
\end_inset
+</cell>
+</row>
+</lyxtabular>
-Install and Search PATHS
-\begin_inset Quotes srd
\end_inset
-.
-\newline
-On most systems you will need super-user privilages to do this.
-\layout Subsection
-
-Components of SDCC
-\layout Standard
-SDCC is not just a compiler, but a collection of tools by various developers.
- These include linkers, assemblers, simulators and other components.
- Here is a summary of some of the components.
- Note that the included simulator and assembler have separate documentation
- which you can find in the source package in their respective directories.
- As SDCC grows to include support for other processors, other packages from
- various developers are included and may have their own sets of documentation.
\newline
-\newline
-You might want to look at the files which are installed in <installdir>.
- At the time of this writing, we find the following programs for gcc-builds:
+\layout Standard
+\noindent
+'configure' also computes relative paths.
+ This is needed for full relocatability of a binary package and to complete
+ search paths (see section search paths below):
\newline
-\newline
-In <installdir>/bin:
-\layout Itemize
-
-sdcc - The compiler.
-\layout Itemize
+\layout Standard
+\align center
-sdcpp - The C preprocessor.
-\layout Itemize
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="3">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-asx8051 - The assembler for 8051 type processors.
-\layout Itemize
+\layout Standard
-as-z80
-\series bold
-,
-\series default
-as-gbz80 - The Z80 and GameBoy Z80 assemblers.
-\layout Itemize
+Variable (computed)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-aslink -The linker for 8051 type processors.
-\layout Itemize
+\layout Standard
-link-z80
-\series bold
-,
-\series default
-link-gbz80 - The Z80 and GameBoy Z80 linkers.
-\layout Itemize
+default
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-s51 - The ucSim 8051 simulator.
-\layout Itemize
+\layout Standard
-sdcdb - The source debugger.
-\layout Itemize
+Win32 builds
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-packihx - A tool to pack (compress) Intel hex files.
\layout Standard
-In <installdir>/share/sdcc/include
-\layout Itemize
-the include files
+\emph on
+BIN2DATA_DIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-In <installdir>/share/sdcc/lib
-\layout Itemize
+../share
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-the subdirs src and small, large, z80, gbz80 and ds390 with the precompiled
- relocatables.
\layout Standard
-In <installdir>/share/sdcc/doc
-\layout Itemize
+..
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-the documentation
\layout Standard
-As development for other processors proceeds, this list will expand to include
- executables to support processors like AVR, PIC, etc.
-\layout Subsubsection
-sdcc - The Compiler
+\emph on
+PREFIX2BIN_DIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-This is the actual compiler, it in turn uses the c-preprocessor and invokes
- the assembler and linkage editor.
-\layout Subsubsection
+bin
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-sdcpp - The C-Preprocessor
\layout Standard
-The preprocessor is a modified version of the GNU preprocessor.
- The C preprocessor is used to pull in #include sources, process #ifdef
- statements, #defines and so on.
-\layout Subsubsection
+bin
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-asx8051, as-z80, as-gbz80, aslink, link-z80, link-gbz80 - The Assemblers
- and Linkage Editors
\layout Standard
-This is retargettable assembler & linkage editor, it was developed by Alan
- Baldwin.
- John Hartman created the version for 8051, and I (Sandeep) have made some
- enhancements and bug fixes for it to work properly with the SDCC.
-\layout Subsubsection
-s51 - The Simulator
+\emph on
+PREFIX2DATA_DIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-S51 is a freeware, opensource simulator developed by Daniel Drotos (
-\begin_inset LatexCommand \url{mailto:drdani@mazsola.iit.uni-miskolc.hu}
+share/sdcc
+\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
-).
- The simulator is built as part of the build process.
- For more information visit Daniel's website at:
-\begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
+\newline
+
+\layout Standard
+\noindent
+Examples:
+\layout LyX-Code
+
+./configure
+\newline
+./configure -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
\end_inset
-.
- It currently support the core mcs51, the Dallas DS80C390 and the Philips
- XA51 family.
-\layout Subsubsection
+-prefix=
+\begin_inset Quotes srd
+\end_inset
+
+/usr/bin
+\begin_inset Quotes srd
+\end_inset
+
+ -
+\begin_inset ERT
+status Collapsed
-sdcdb - Source Level Debugger
\layout Standard
+\backslash
+/
+\end_inset
+
+-datadir=
+\begin_inset Quotes srd
+\end_inset
+
+/usr/share
+\begin_inset Quotes srd
+\end_inset
-\family typewriter
-\shape italic
-<todo: is this thing still alive?>
-\newline
\newline
+./configure -
+\begin_inset ERT
+status Collapsed
-\family default
-\shape default
-Sdcdb is the companion source level debugger.
- The current version of the debugger uses Daniel's Simulator S51, but can
- be easily changed to use other simulators.
-\layout Section
+\layout Standard
-Using SDCC
-\layout Subsection
+\backslash
+/
+\end_inset
-Compiling
-\layout Subsubsection
+-disable-avr-port -
+\begin_inset ERT
+status Collapsed
-Single Source File Projects
\layout Standard
-For single source file 8051 projects the process is very simple.
- Compile your programs with the following command
-\family sans
-\series bold
-"sdcc sourcefile.c".
+\backslash
+/
+\end_inset
-\family default
-\series default
- This will compile, assemble and link your source file.
- Output files are as follows
-\newline
+-disable-xa51-port
+\layout Standard
+
+To cross compile on linux for Mingw32 (see also 'sdcc/support/scripts/sdcc_mingw
+32'):
+\layout LyX-Code
+
+./configure
+\backslash
\newline
-sourcefile.asm - Assembler source file created by the compiler
-\newline
-sourcefile.lst - Assembler listing file created by the Assembler
-\newline
-sourcefile.rst - Assembler listing file updated with linkedit information,
- created by linkage editor
-\newline
-sourcefile.sym - symbol listing for the sourcefile, created by the assembler
-\newline
-sourcefile.rel - Object file created by the assembler, input to Linkage editor
-\newline
-sourcefile.map - The memory map for the load module, created by the Linker
-\newline
-sourcefile.ihx - The load module in Intel hex format (you can select the
- Motorola S19 format with ---out-fmt-s19)
-\newline
-sourcefile.cdb - An optional file (with ---debug) containing debug information
-\newline
-sourcefile.dump* - Dump file to debug the compiler it self (with ---dumpall)
- (see section
-\begin_inset Quotes sld
+CC=
+\begin_inset Quotes srd
\end_inset
-Anatomy of the compiler
+i586-mingw32msvc-gcc
\begin_inset Quotes srd
\end_inset
-).
-\layout Subsubsection
+ CXX=
+\begin_inset Quotes srd
+\end_inset
-Projects with Multiple Source Files
-\layout Standard
+i586-mingw32msvc-g++
+\begin_inset Quotes srd
+\end_inset
-SDCC can compile only ONE file at a time.
- Let us for example assume that you have a project containing the following
- files:
+
+\backslash
+
\newline
+RANLIB=
+\begin_inset Quotes srd
+\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
+i586-mingw32msvc-ranlib
+\begin_inset Quotes srd
+\end_inset
-\size footnotesize
+
+\backslash
\newline
+STRIP=
+\begin_inset Quotes srd
+\end_inset
+
+i586-mingw32msvc-strip
+\begin_inset Quotes srd
+\end_inset
-\size default
-The first two files will need to be compiled separately with the commands:
-\size footnotesize
-\size default
+\backslash
\newline
+-
+\begin_inset ERT
+status Collapsed
-\newline
+\layout Standard
-\family sans
-\series bold
-sdcc\SpecialChar ~
--c\SpecialChar ~
-foo1.c
-\family default
-\series default
-\size footnotesize
+\backslash
+/
+\end_inset
-\newline
+-prefix=
+\begin_inset Quotes srd
+\end_inset
-\family sans
-\series bold
-\size default
-sdcc\SpecialChar ~
--c\SpecialChar ~
-foo2.c
-\family default
-\series default
+/sdcc
+\begin_inset Quotes srd
+\end_inset
-\newline
+
+\backslash
\newline
-Then compile the source file containing the
-\emph on
-main()
-\emph default
- function and link the files together with the following command:
-\newline
+-
+\begin_inset ERT
+status Collapsed
-\newline
+\layout Standard
-\family sans
-\series bold
-sdcc\SpecialChar ~
-foomain.c\SpecialChar ~
-foo1.rel\SpecialChar ~
-foo2.rel
-\family default
-\series default
+\backslash
+/
+\end_inset
-\newline
+-datadir=
+\begin_inset Quotes srd
+\end_inset
-\newline
-Alternatively,
-\emph on
-foomain.c
-\emph default
-can be separately compiled as well:
-\family sans
-\series bold
+/sdcc
+\begin_inset Quotes srd
+\end_inset
-\newline
+
+\backslash
\newline
-sdcc\SpecialChar ~
--c\SpecialChar ~
-foomain.c
-\newline
-sdcc foomain.rel foo1.rel foo2.rel
-\newline
+docdir=
+\begin_inset Quotes srd
+\end_inset
-\newline
+/sdcc/doc
+\begin_inset Quotes srd
+\end_inset
-\family default
-\series default
-The file containing the
-\emph on
-main()
-\emph default
- function
-\emph on
-\emph default
-\noun on
-must
-\noun default
- be the
-\noun on
-first
-\noun default
- file specified in the command line, since the linkage editor processes
- file in the order they are presented to it.
-\layout Subsubsection
-
-Projects with Additional Libraries
-\layout Standard
+\backslash
-Some reusable routines may be compiled into a library, see the documentation
- for the assembler and linkage editor (which are in <installdir>/share/sdcc/doc)
- for how to create a
-\emph on
-.lib
-\emph default
- library file.
- Libraries created in this manner can be included in the command line.
- Make sure you include the -L <library-path> option to tell the linker where
- to look for these files if they are not in the current directory.
- Here is an example, assuming you have the source file
-\emph on
-foomain.c
-\emph default
- and a library
-\emph on
- foolib.lib
-\emph default
- in the directory
-\emph on
-mylib
-\emph default
- (if that is not the same as your current project):
\newline
+include_dir_suffix=
+\begin_inset Quotes srd
+\end_inset
-\newline
+include
+\begin_inset Quotes srd
+\end_inset
-\family sans
-\series bold
-sdcc foomain.c foolib.lib -L mylib
-\newline
+
+\backslash
\newline
+lib_dir_suffix=
+\begin_inset Quotes srd
+\end_inset
-\family default
-\series default
-Note here that
-\emph on
- mylib
-\emph default
- must be an absolute path name.
-\newline
+lib
+\begin_inset Quotes srd
+\end_inset
-\newline
-The most efficient way to use libraries is to keep seperate modules in seperate
- source files.
- The lib file now should name all the modules.rel files.
- For an example see the standard library file
-\emph on
-libsdcc.lib
-\emph default
- in the directory <installdir>/share/lib/small.
-\layout Subsection
+
+\backslash
-Command Line Options
-\layout Subsubsection
+\newline
+sdccconf_h_dir_separator=
+\begin_inset Quotes srd
+\end_inset
-Processor Selection Options
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
-\series bold
--mmcs51
-\series default
- Generate code for the MCS51 (8051) family of processors.
- This is the default processor target.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+\backslash
-\series bold
--mds390
-\series default
- Generate code for the DS80C390 processor.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+\begin_inset Quotes srd
+\end_inset
-\series bold
--mz80
-\series default
- Generate code for the Z80 family of processors.
-\layout List
-\labelwidthstring 00.00.0000
+
+\backslash
+\newline
+-
+\begin_inset ERT
+status Collapsed
-\series bold
--mgbz80
-\series default
- Generate code for the GameBoy Z80 processor.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+\backslash
+/
+\end_inset
-\series bold
--mavr
-\series default
- Generate code for the Atmel AVR processor (In development, not complete).
-\layout List
-\labelwidthstring 00.00.0000
+-disable-device-lib-build
+\backslash
+\newline
+-
+\begin_inset ERT
+status Collapsed
-\series bold
--mpic14
-\series default
- Generate code for the PIC 14-bit processors (In development, not complete).
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+\backslash
+/
+\end_inset
-\series bold
--mtlcs900h
-\series default
- Generate code for the Toshiba TLCS-900H processor (In development, not
- complete).
-\layout List
-\labelwidthstring 00.00.0000
+-disable-ucsim
+\backslash
+\newline
+-
+\begin_inset ERT
+status Collapsed
-\series bold
--mxa51
-\series default
- Generate code for the Philips XA51 processor (In development, not complete).
-\layout Subsubsection
+\layout Standard
-Preprocessor Options
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+/
+\end_inset
+-host=i586-mingw32msvc -
+\begin_inset ERT
+status Collapsed
-\series bold
--I<path>
-\series default
- The additional location where the pre processor will look for <..h> or
-\begin_inset Quotes eld
-\end_inset
+\layout Standard
-..h
-\begin_inset Quotes erd
+\backslash
+/
\end_inset
- files.
-\layout List
-\labelwidthstring 00.00.0000
+-build=unknown-unknown-linux-gnu
+\layout Standard
+To
+\begin_inset Quotes sld
+\end_inset
-\series bold
--D<macro[=value]>
-\series default
- Command line definition of macros.
- Passed to the pre processor.
-\layout List
-\labelwidthstring 00.00.0000
+cross
+\begin_inset Quotes srd
+\end_inset
+compile on Cygwin for Mingw32 (see also sdcc/support/scripts/sdcc_cygwin_mingw32
+):
+\layout LyX-Code
-\series bold
--M
-\series default
- Tell the preprocessor to output a rule suitable for make describing the
- dependencies of each object file.
- For each source file, the preprocessor outputs one make-rule whose target
- is the object file name for that source file and whose dependencies are
- all the files `#include'd in it.
- This rule may be a single line or may be continued with `
+./configure -C
\backslash
-'-newline if it is long.
- The list of rules is printed on standard output instead of the preprocessed
- C program.
- `-M' implies `-E'.
-\layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--C
-\series default
- Tell the preprocessor not to discard comments.
- Used with the `-E' option.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+CFLAGS=
+\begin_inset Quotes srd
+\end_inset
+-mno-cygwin -O2
+\begin_inset Quotes srd
+\end_inset
-\series bold
--MM
-\size large
-\bar under
-\series default
-\size default
-\bar default
-Like `-M' but the output mentions only the user header files included with
- `#include
-\begin_inset Quotes eld
+\backslash
+
+\newline
+LDFLAGS=
+\begin_inset Quotes srd
\end_inset
-file"'.
- System header files included with `#include <file>' are omitted.
-\layout List
-\labelwidthstring 00.00.0000
+-mno-cygwin
+\begin_inset Quotes srd
+\end_inset
+
+\backslash
-\series bold
--Aquestion(answer)
-\series default
- Assert the answer answer for question, in case it is tested with a preprocessor
- conditional such as `#if #question(answer)'.
- `-A-' disables the standard assertions that normally describe the target
- machine.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+-
+\begin_inset ERT
+status Collapsed
+\layout Standard
-\series bold
--Aquestion
-\series default
- (answer) Assert the answer answer for question, in case it is tested with
- a preprocessor conditional such as `#if #question(answer)'.
- `-A-' disables the standard assertions that normally describe the target
- machine.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+/
+\end_inset
+-prefix=
+\begin_inset Quotes srd
+\end_inset
-\series bold
--Umacro
-\series default
- Undefine macro macro.
- `-U' options are evaluated after all `-D' options, but before any `-include'
- and `-imacros' options.
-\layout List
-\labelwidthstring 00.00.0000
+/sdcc
+\begin_inset Quotes srd
+\end_inset
+
+\backslash
-\series bold
--dM
-\series default
- Tell the preprocessor to output only a list of the macro definitions that
- are in effect at the end of preprocessing.
- Used with the `-E' option.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+-
+\begin_inset ERT
+status Collapsed
+\layout Standard
-\series bold
--dD
-\series default
- Tell the preprocessor to pass all macro definitions into the output, in
- their proper sequence in the rest of the output.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+/
+\end_inset
+-datadir=
+\begin_inset Quotes srd
+\end_inset
+
+/sdcc
+\begin_inset Quotes srd
+\end_inset
-\series bold
--dN
-\size large
-\bar under
-\series default
-\size default
-\bar default
-Like `-dD' except that the macro arguments and contents are omitted.
- Only `#define name' is included in the output.
-\layout Subsubsection
+\backslash
-Linker Options
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+docdir=
+\begin_inset Quotes srd
+\end_inset
+/sdcc/doc
+\begin_inset Quotes srd
+\end_inset
-\series bold
--L\SpecialChar ~
----lib-path
-\bar under
-\series default
-\bar default
-<absolute path to additional libraries> This option is passed to the linkage
- editor's additional libraries search path.
- The path name must be absolute.
- Additional library files may be specified in the command line.
- See section Compiling programs for more details.
-\layout List
-\labelwidthstring 00.00.0000
-
+\backslash
+
+\newline
+include_dir_suffix=
+\begin_inset Quotes srd
+\end_inset
-\series bold
----xram-loc
-\series default
-<Value> The start location of the external ram, default value is 0.
- The value entered can be in Hexadecimal or Decimal format, e.g.: ---xram-loc
- 0x8000 or ---xram-loc 32768.
-\layout List
-\labelwidthstring 00.00.0000
+include
+\begin_inset Quotes srd
+\end_inset
+
+\backslash
-\series bold
----code-loc
-\series default
-<Value> The start location of the code segment, default value 0.
- Note when this option is used the interrupt vector table is also relocated
- to the given address.
- The value entered can be in Hexadecimal or Decimal format, e.g.: ---code-loc
- 0x8000 or ---code-loc 32768.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+lib_dir_suffix=
+\begin_inset Quotes srd
+\end_inset
+lib
+\begin_inset Quotes srd
+\end_inset
-\series bold
----stack-loc
-\series default
-<Value> By default the stack is placed after the data segment.
- Using this option the stack can be placed anywhere in the internal memory
- space of the 8051.
- The value entered can be in Hexadecimal or Decimal format, e.g.
- ---stack-loc 0x20 or ---stack-loc 32.
- Since the sp register is incremented before a push or call, the initial
- sp will be set to one byte prior the provided value.
- The provided value should not overlap any other memory areas such as used
- register banks or the data segment and with enough space for the current
- application.
-\layout List
-\labelwidthstring 00.00.0000
+
+\backslash
+\newline
+sdccconf_h_dir_separator=
+\begin_inset Quotes srd
+\end_inset
-\series bold
----data-loc
-\series default
-<Value> The start location of the internal ram data segment.
- The value entered can be in Hexadecimal or Decimal format, eg.
- ---data-loc 0x20 or ---data-loc 32.
- (By default, the start location of the internal ram data segment is set
- as low as possible in memory, taking into account the used register banks
- and the bit segment at address 0x20.
- For example if register banks 0 and 1 are used without bit variables, the
- data segment will be set, if ---data-loc is not used, to location 0x10.)
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
-\series bold
----idata-loc
-\series default
-<Value> The start location of the indirectly addressable internal ram, default
- value is 0x80.
- The value entered can be in Hexadecimal or Decimal format, eg.
- ---idata-loc 0x88 or ---idata-loc 136.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+\backslash
-\series bold
----out-fmt-ihx
-\bar under
-
-\series default
-\bar default
-The linker output (final object code) is in Intel Hex format.
- (This is the default option).
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+\begin_inset Quotes srd
+\end_inset
-\series bold
----out-fmt-s19
-\bar under
-\series default
-\bar default
-The linker output (final object code) is in Motorola S19 format.
-\layout Subsubsection
+\backslash
-MCS51 Options
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+-
+\begin_inset ERT
+status Collapsed
+\layout Standard
-\series bold
----model-large
-\series default
- Generate code for Large model programs see section Memory Models for more
- details.
- If this option is used all source files in the project should be compiled
- with this option.
- In addition the standard library routines are compiled with small model,
- they will need to be recompiled.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+/
+\end_inset
+-disable-ucsim
+\layout Standard
-\series bold
----model-small
-\series default
-\size large
-\emph on
-
-\size default
-\emph default
-Generate code for Small Model programs see section Memory Models for more
- details.
- This is the default model.
-\layout Subsubsection
+'configure' is quite slow on Cygwin (at least on windows before Win2000/XP).
+ The option '-
+\begin_inset ERT
+status Collapsed
-DS390 Options
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+\backslash
+/
+\end_inset
-\series bold
----model-flat24
-\series default
-\size large
-\emph on
-
-\size default
-\emph default
-Generate 24-bit flat mode code.
- This is the one and only that the ds390 code generator supports right now
- and is default when using
-\emph on
--mds390
-\emph default
-.
- See section Memory Models for more details.
-\layout List
-\labelwidthstring 00.00.0000
+-C' turns on caching, which gives a little bit extra speed.
+ However if options are changed, it can be necessary to delete the config.cache
+ file.
+\layout Section
+Install paths
+\begin_inset LatexCommand \label{sub:Install-paths}
-\series bold
----stack-10bit
-\series default
- Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
- This is the one and only that the ds390 code generator supports right now
- and is default when using
-\emph on
--mds390
-\emph default
-.
- In this mode, the stack is located in the lower 1K of the internal RAM,
- which is mapped to 0x400000.
- Note that the support is incomplete, since it still uses a single byte
- as the stack pointer.
- This means that only the lower 256 bytes of the potential 1K stack space
- will actually be used.
- However, this does allow you to reclaim the precious 256 bytes of low RAM
- for use for the DATA and IDATA segments.
- The compiler will not generate any code to put the processor into 10 bit
- stack mode.
- It is important to ensure that the processor is in this mode before calling
- any re-entrant functions compiled with this option.
- In principle, this should work with the
-\emph on
----stack-auto
-\emph default
- option, but that has not been tested.
- It is incompatible with the
-\emph on
----xstack
-\emph default
- option.
- It also only makes sense if the processor is in 24 bit contiguous addressing
- mode (see the
-\emph on
----model-flat24 option
-\emph default
-).
-\layout Subsubsection
+\end_inset
-Optimization Options
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset LatexCommand \index{Install paths}
-\series bold
----nogcse
-\series default
- Will not do global subexpression elimination, this option may be used when
- the compiler creates undesirably large stack/data spaces to store compiler
- temporaries.
- A warning message will be generated when this happens and the compiler
- will indicate the number of extra bytes it allocated.
- It recommended that this option NOT be used, #pragma\SpecialChar ~
-NOGCSE can be used
- to turn off global subexpression elimination for a given function only.
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
-\series bold
----noinvariant
-\series default
- Will not do loop invariant optimizations, this may be turned off for reasons
- explained for the previous option.
- For more details of loop optimizations performed see section Loop Invariants.It
- recommended that this option NOT be used, #pragma\SpecialChar ~
-NOINVARIANT can be used
- to turn off invariant optimizations for a given function only.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+\added_space_top medskip \align center
+\begin_inset Tabular
+<lyxtabular version="3" rows="5" 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
-\series bold
----noinduction
-\series default
- Will not do loop induction optimizations, see section strength reduction
- for more details.It is recommended that this option is NOT used, #pragma\SpecialChar ~
-NOINDUCT
-ION can be used to turn off induction optimizations for a given function
- only.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
\series bold
----nojtbound
-\size large
-\bar under
-
-\series default
-\size default
-\bar default
- Will not generate boundary condition check when switch statements are implement
-ed using jump-tables.
- See section Switch Statements for more details.
- It is recommended that this option is NOT used, #pragma\SpecialChar ~
-NOJTBOUND can be
- used to turn off boundary checking for jump tables for a given function
- only.
-\layout List
-\labelwidthstring 00.00.0000
-
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\series bold
----noloopreverse
-\series default
-\size large
-
-\size default
-Will not do loop reversal optimization.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
\series bold
----no-xinit-opt
-\series default
- This will disable the memcpy of initialized data in far space from code
- space
-\layout Subsubsection
+Path
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Other Options
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
\series bold
--c\SpecialChar ~
----compile-only
-\series default
- will compile and assemble the source, but will not call the linkage editor.
-\layout List
-\labelwidthstring 00.00.0000
+Default
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
\series bold
--E
-\series default
- Run only the C preprocessor.
- Preprocess all the C source files specified and output the results to standard
- output.
-\layout List
-\labelwidthstring 00.00.0000
+Win32 builds
+\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
--o\SpecialChar ~
-<path/file>
-\series default
-The output path resp.
- file where everything will be placed.
- If the parameter is a path, it must have a trailing slash (or backslash
- for the Windows binaries) to be recognized as a path.
-
-\layout List
-\labelwidthstring 00.00.0000
+Binary files*
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-\series bold
----stack-auto
-\series default
-\size large
-\emph on
-
-\size default
-\emph default
-All functions in the source file will be compiled as
\emph on
-reentrant
-\emph default
-, i.e.
- the parameters and local variables will be allocated on the stack.
- see section Parameters and Local Variables for more details.
- If this option is used all source files in the project should be compiled
- with this option.
-
-\layout List
-\labelwidthstring 00.00.0000
+$EXEC_PREFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----xstack
-\series default
- Uses a pseudo stack in the first 256 bytes in the external ram for allocating
- variables and passing parameters.
- See section on external stack for more details.
-\layout List
-\labelwidthstring 00.00.0000
+/usr/local/bin
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----callee-saves function1[,function2][,function3]....
-\series default
- The compiler by default uses a caller saves convention for register saving
- across function calls, however this can cause unneccessary register pushing
- & popping when calling small functions from larger functions.
- This option can be used to switch the register saving convention for the
- function names specified.
- The compiler will not save registers when calling these functions, no extra
- code will be generated 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 interprocedural analysis) will be able
- to determine the appropriate scheme to use for each function call.
- DO NOT use this option for built-in functions such as _muluint..., if this
- option is used for a library function the appropriate library function
- needs to be recompiled with the same option.
- If the project consists of multiple source files then all the source file
- should be compiled with the same ---callee-saves option string.
- Also see #pragma\SpecialChar ~
-CALLEE-SAVES.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+sdcc
+\backslash
+bin
+\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
----debug
-\bar under
-
-\series default
-\bar default
-When this option is used the compiler will generate debug information, that
- can be used with the SDCDB.
- The debug information is collected in a file with .cdb extension.
- For more information see documentation for SDCDB.
-\layout List
-\labelwidthstring 00.00.0000
+Include files
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----peep-file
-\series default
-<filename> This option can be used to use additional rules to be used by
- the peep hole optimizer.
- See section Peep Hole optimizations for details on how to write these rules.
-\layout List
-\labelwidthstring 00.00.0000
+\emph on
+$DATADIR/ $INCLUDE_DIR_SUFFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\series bold
--S
-\size large
-\bar under
-
-\series default
-\size default
-\bar default
-Stop after the stage of compilation proper; do not assemble.
- The output is an assembler code file for the input file specified.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+/usr/local/share/sdcc/include
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\series bold
--Wa_asmOption[,asmOption]
-\series default
-...
- Pass the asmOption to the assembler.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
-\series bold
--Wl_linkOption[,linkOption]
-\series default
-...
- Pass the linkOption to the linker.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+sdcc
+\backslash
+include
+\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
----int-long-reent
-\series default
-\size large
-
-\size default
- Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
- Note by default these libraries are compiled as non-reentrant.
- See section Installation for more details.
-\layout List
-\labelwidthstring 00.00.0000
+Library file**
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
-\series bold
----cyclomatic
-\bar under
-
-\series default
-\bar default
-This option will cause the compiler to generate an information message for
- each function in the source file.
- The message contains some
-\emph on
-important
-\emph default
- information about the function.
- The number of edges and nodes the compiler detected in the control flow
- graph of the function, and most importantly the
\emph on
-cyclomatic complexity
-\emph default
- see section on Cyclomatic Complexity for more details.
-\layout List
-\labelwidthstring 00.00.0000
+$DATADIR/$LIB_DIR_SUFFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----float-reent
-\bar under
-
-\series default
-\bar default
- Floating point library is compiled as reentrant.See section Installation
- for more details.
-\layout List
-\labelwidthstring 00.00.0000
+/usr/local/share/sdcc/lib
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----nooverlay
-\series default
- The compiler will not overlay parameters and local variables of any function,
- see section Parameters and local variables for more details.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+sdcc
+\backslash
+lib
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\series bold
----main-return
-\series default
- This option can be used when the code generated is called by a monitor
- program.
- The compiler will generate a 'ret' upon return from the 'main' function.
- The default option is to lock up i.e.
- generate a 'ljmp '.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+Documentation
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\series bold
----no-peep
-\series default
- Disable peep-hole optimization.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
-\series bold
----peep-asm
-\series default
- Pass the inline assembler code through the peep hole optimizer.
- This can cause unexpected changes to inline assembler code, please go through
- the peephole optimizer rules defined in the source file tree '<target>/peeph.def
-' before using this option.
-\layout List
-\labelwidthstring 00.00.0000
+\emph on
+$DOCDIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----iram-size
-\series default
-<Value> Causes the linker to check if the internal ram usage is within limits
- of the given value.
-\layout List
-\labelwidthstring 00.00.0000
+/usr/local/share/sdcc/doc
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----xram-size
-\series default
-<Value> Causes the linker to check if the external ram usage is within limits
- of the given value.
-\layout List
-\labelwidthstring 00.00.0000
+\backslash
+sdcc
+\backslash
+doc
+\end_inset
+</cell>
+</row>
+</lyxtabular>
-\series bold
----code-size
-\series default
-<Value> Causes the linker to check if the code usage is within limits of
- the given value.
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
-\series bold
----nostdincl
-\series default
- This will prevent the compiler from passing on the default include path
- to the preprocessor.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Verse
-\series bold
----nostdlib
-\series default
- This will prevent the compiler from passing on the default library path
- to the linker.
-\layout List
-\labelwidthstring 00.00.0000
+\size footnotesize
+*compiler, preprocessor, assembler, and linker
+\newline
+**the
+\shape italic
+model
+\shape default
+ is auto-appended by the compiler, e.g.
+ small, large, z80, ds390 etc
+\layout Standard
+\noindent
+The install paths can still be changed during `make install` with e.g.:
+\layout LyX-Code
+make install prefix=$(HOME)/local/sdcc
+\layout Standard
-\series bold
----verbose
-\series default
- Shows the various actions the compiler is performing.
-\layout List
-\labelwidthstring 00.00.0000
+Of course this doesn't change the search paths compiled into the binaries.
+\layout Section
+Search Paths
+\begin_inset LatexCommand \label{sub:Search-Paths}
-\series bold
--V
-\series default
- Shows the actual commands the compiler is executing.
-\layout List
-\labelwidthstring 00.00.0000
+\end_inset
-\series bold
----no-c-code-in-asm
-\series default
- Hides your ugly and inefficient c-code from the asm file, so you can always
- blame the compiler :).
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset LatexCommand \index{Search path}
+\end_inset
-\series bold
----i-code-in-asm
-\series default
- Include i-codes in the asm file.
- Looks like noise but is most helpfull for debugging the compiler itself.
-\layout Subsubsection
-Intermediate Dump Options
\layout Standard
-The following options are provided for the purpose of retargetting and debugging
- the compiler.
- These provided a means to dump the intermediate code (iCode) generated
- by the compiler in human readable form at various stages of the compilation
- process.
-
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
----dumpraw
-\series default
- This option will cause the compiler to dump the intermediate code into
- a file of named
+Some search paths or parts of them are determined by configure variables
+ (in
\emph on
-<source filename>.dumpraw
+italics
\emph default
- just after the intermediate code has been generated for a function, i.e.
- before any optimizations are done.
- The basic blocks at this stage ordered in the depth first number, so they
- may not be in sequence of execution.
-\layout List
-\labelwidthstring 00.00.0000
-
+, see section above).
+ Further search paths are determined by environment variables during runtime.
+
+\newline
+The paths searched when running the compiler are as follows (the first catch
+ wins):
+\newline
-\series bold
----dumpgcse
-\series default
- Will create a dump of iCode's, after global subexpression elimination,
- into a file named
-\emph on
-<source filename>.dumpgcse.
-\layout List
-\labelwidthstring 00.00.0000
+\newline
+1.
+ Binary files (preprocessor, assembler and linker)
+\newline
+\layout Standard
+\align center
-\series bold
----dumpdeadcode
-\series default
- Will create a dump of iCode's, after deadcode elimination, into a file
- named
-\emph on
-<source filename>.dumpdeadcode.
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="3">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" width="0in">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----dumploop
-\series default
-\size large
-
-\size default
-Will create a dump of iCode's, after loop optimizations, into a file named
-
-\emph on
-<source filename>.dumploop.
-\layout List
-\labelwidthstring 00.00.0000
+Search path
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----dumprange
-\series default
-\size large
-
-\size default
-Will create a dump of iCode's, after live range analysis, into a file named
-
-\emph on
-<source filename>.dumprange.
-\layout List
-\labelwidthstring 00.00.0000
+default
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----dumlrange
-\series default
- Will dump the life ranges for all symbols.
-\layout List
-\labelwidthstring 00.00.0000
+Win32 builds
+\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
----dumpregassign
-\bar under
-
-\series default
-\bar default
-Will create a dump of iCode's, after register assignment, into a file named
-
+$SDCC_HOME/
\emph on
-<source filename>.dumprassgn.
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
----dumplrange
-\series default
- Will create a dump of the live ranges of iTemp's
-\layout List
-\labelwidthstring 00.00.0000
+$PPREFIX2BIN_DIR
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
----dumpall
-\size large
-\bar under
-
-\series default
-\size default
-\bar default
-Will cause all the above mentioned dumps to be created.
-\layout Subsection
+$SDCC_HOME/bin
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Environment variables
\layout Standard
-SDCC recognizes the following environment variables:
-\layout List
-\labelwidthstring 00.00.0000
+$SDCC_HOME
+\backslash
+bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
-SDCC_LEAVE_SIGNALS
-\series default
- SDCC installs a signal handler to be able to delete temporary files after
- an user break (^C) or an exception.
- If this environment variable is set, SDCC won't install the signal handler
- in order to be able to debug SDCC.
-\layout List
-\labelwidthstring 00.00.0000
+Path of argv[0] (if available)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
-TMP,\SpecialChar ~
-TEMP,\SpecialChar ~
-TMPDIR
-\series default
- Path, where temporary files will be created.
- The order of the variables is the search order.
- In a standard *nix environment these variables are not set, and there's
- no need to set them.
- On Windows it's recommended to set one of them.
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
-(coming\SpecialChar ~
-soon:\SpecialChar ~
-SDCC_BIN_PATH)
-\series default
- Path, see
-\begin_inset Quotes sld
+Path of argv[0]
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-2.1 Install and search paths
-\begin_inset Quotes srd
-\end_inset
+\layout Standard
-.
-\layout List
-\labelwidthstring 00.00.0000
+Path of argv[0]
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
-(coming\SpecialChar ~
-soon:\SpecialChar ~
-SDCC_INCLUDE_PATH)
-\series default
- Path, see
-\begin_inset Quotes sld
+$PATH
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-2.1 Install and search paths
-\begin_inset Quotes srd
-\end_inset
+\layout Standard
-.
-\layout List
-\labelwidthstring 00.00.0000
+$PATH
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\series bold
-(coming\SpecialChar ~
-soon:\SpecialChar ~
-SDCC_LIB_PATH)
-\series default
- Path, see
-\begin_inset Quotes sld
+$PATH
\end_inset
+</cell>
+</row>
+</lyxtabular>
-2.1 Install and search paths
-\begin_inset Quotes srd
\end_inset
-.
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
-SDCCDIR\SpecialChar ~
-(soon\SpecialChar ~
-replaced\SpecialChar ~
-by:\SpecialChar ~
-SDCCPATH)
-\series default
- Path, see
-\begin_inset Quotes sld
-\end_inset
+
+\newline
-2.1 Install and search paths
-\begin_inset Quotes srd
-\end_inset
+\layout Standard
+\noindent
+2.
+ Include files
+\newline
-.
\layout Standard
+\align center
-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 documentated.
-\layout Subsection
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="1.5in">
+<column alignment="block" valignment="top" leftline="true" width="1.5in">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-MCS51/DS390 Storage Class Language Extensions
\layout Standard
-In addition to the ANSI storage classes SDCC allows the following MCS51
- specific storage classes.
-\layout Subsubsection
+Search path
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-xdata
\layout Standard
-Variables declared with this storage class will be placed in the extern
- RAM.
- This is the
-\series bold
default
-\series default
- storage class for Large Memory model, e.g.:
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-xdata unsigned char xduc;
-\layout Subsubsection
+Win32 builds
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-data
\layout Standard
-This is the
-\series bold
-default
-\series default
- storage class for Small Memory model.
- Variables declared with this storage class will be allocated in the internal
- RAM, e.g.:
-\newline
+-
+\begin_inset ERT
+status Collapsed
-\newline
+\layout Standard
-\family typewriter
-data int iramdata;
-\layout Subsubsection
+\backslash
+/
+\end_inset
+
+-I dir
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-idata
\layout Standard
-Variables declared with this storage class will be allocated into the indirectly
- addressable portion of the internal ram of a 8051, e.g.:
-\newline
+-
+\begin_inset ERT
+status Collapsed
-\newline
+\layout Standard
-\family typewriter
-idata int idi;
-\layout Subsubsection
+\backslash
+/
+\end_inset
+
+-I dir
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-bit
\layout Standard
-This is a data-type and a storage class specifier.
- When a variable is declared as a bit, it is allocated into the bit addressable
- memory of 8051, e.g.:
-\newline
+-
+\begin_inset ERT
+status Collapsed
-\newline
+\layout Standard
-\family typewriter
-bit iFlag;
-\layout Subsubsection
+\backslash
+/
+\end_inset
+
+-I dir
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-sfr / sbit
\layout Standard
-Like the bit keyword,
-\emph on
-sfr / sbit
-\emph default
-signifies both a data-type and storage class, they are used to describe
- the special function registers and special bit variables of a 8051, eg:
-\newline
+$SDCC_INCLUDE
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-sfr at 0x80 P0; /* special function register P0 at location 0x80 */
-\newline
-sbit at 0xd7 CY; /* CY (Carry Flag) */
-\layout Subsection
+$SDCC_INCLUDE
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Pointers
\layout Standard
-SDCC allows (via language extensions) pointers to explicitly point to any
- of the memory spaces of the 8051.
- In addition to the explicit pointers, the compiler uses (by default) generic
- pointers which can be used to point to any of the memory spaces.
-\newline
-
-\newline
-Pointer declaration examples:
-\newline
+$SDCC_INCLUDE
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\size small
+\layout Standard
+$SDCC_HOME/
\newline
-\family typewriter
-\size default
-/* pointer physically in xternal ram pointing to object in internal ram
- */
-\newline
-data unsigned char * xdata p;
+\emph on
+$PREFIX2DATA_DIR/
\newline
+$INCLUDE_DIR_SUFFIX
+\end_inset
+</cell>
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-/* pointer physically in code rom pointing to data in xdata space */
-\newline
-xdata unsigned char * code p;
-\newline
+\layout Standard
+$SDCC_ HOME/
\newline
-/* pointer physically in code space pointing to data in code space */
-\newline
-code unsigned char * code p;
+share/sdcc/
\newline
+include
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-/* the folowing is a generic pointer physically located in xdata space */
-\newline
-char * xdata p;
-\family default
-\size small
+\layout Standard
-\newline
+$SDCC_HOME
+\backslash
+include
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\size default
-Well you get the idea.
-
+path(argv[0])/
\newline
-\newline
-All unqualified pointers are treated as 3-byte (4-byte for the ds390)
\emph on
-generic
+$BIN2DATADIR/
\emph default
- pointers.
-
-\size small
\newline
-\newline
-
-\size default
-The highest order byte of the
-\emph on
-generic
-\emph default
- pointers contains the data space information.
- Assembler support routines are called whenever data is stored or retrieved
- using
\emph on
-generic
-\emph default
- pointers.
- These are useful for developing reusable library routines.
- Explicitly specifying the pointer type will generate the most efficient
- code.
-\layout Subsection
+$INCLUDE_DIR_SUFFIX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Parameters & Local Variables
\layout Standard
-Automatic (local) variables and parameters to functions can either be placed
- on the stack or in data-space.
- The default action of the compiler is to place these variables in the internal
- RAM (for small model) or external RAM (for large model).
- This in fact makes them
-\emph on
-static
-\emph default
- so by default functions are non-reentrant.
-\newline
-
-\newline
-They can be placed on the stack either by using the
-\emph on
- ---stack-auto
-\emph default
- option or by using the
-\emph on
-reentrant
-\emph default
- keyword in the function declaration, e.g.:
-\newline
-
-\size small
-
-\newline
-
-\family typewriter
-\size default
-unsigned char foo(char i) reentrant
-\newline
-{
-\newline
-...
-
-\newline
-}
-\newline
-
-\family default
-
-\newline
-Since stack space on 8051 is limited, the
-\emph on
-reentrant
-\emph default
-keyword or the
-\emph on
- ---stack-auto
-\emph default
- option should be used sparingly.
- Note that the reentrant keyword just means that the parameters & local
- variables will be allocated to the stack, it
-\emph on
-does not
-\emph default
- mean that the function is register bank independent.
-\newline
-
-\newline
-Local variables can be assigned storage classes and absolute addresses,
- e.g.:
-\newline
-
+path(argv[0])/
\newline
-
-\family typewriter
-unsigned char foo() {
+../sdcc/include
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-xdata unsigned char i;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-bit bvar;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-data at 0x31 unsiged char j;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-...
-
-\newline
-}
-\newline
-
-\newline
-
-\family default
-In the above example the variable
-\emph on
-i
-\emph default
- will be allocated in the external ram,
-\emph on
-bvar
-\emph default
- in bit addressable space and
-\emph on
- j
-\emph default
- in internal ram.
- When compiled with
-\emph on
----stack-auto
-\emph default
- or when a function is declared as
-\emph on
-reentrant
-\emph default
- this should only be done for static variables.
-\layout Standard
-
-Parameters however are not allowed any storage class, (storage classes for
- parameters will be ignored), their allocation is governed by the memory
- model in use, and the reentrancy options.
-\layout Subsection
-
-Overlaying
-\layout Standard
-
-For non-reentrant functions SDCC will try to reduce internal ram space usage
- by overlaying parameters and local variables of a function (if possible).
- Parameters and local variables of a function will be allocated to an overlayabl
-e segment if the function has
-\emph on
-no other function calls and the function is non-reentrant and the memory
- model is small.
-
-\emph default
- If an explicit storage class is specified for a local variable, it will
- NOT be overlayed.
-\layout Standard
-
-Note that the compiler (not the linkage editor) makes the decision for overlayin
-g the data items.
- Functions that are called from an interrupt service routine should be preceded
- by a #pragma\SpecialChar ~
-NOOVERLAY if they are not reentrant.
-\layout Standard
-
-Also note that the compiler does not do any processing of inline assembler
- code, so the compiler might incorrectly assign local variables and parameters
- of a function into the overlay segment if the inline assembler code calls
- other c-functions that might use the overlay.
- In that case the #pragma\SpecialChar ~
-NOOVERLAY should be used.
-\layout Standard
-
-Parameters and Local variables of functions that contain 16 or 32 bit multiplica
-tion or division will NOT be overlayed since these are implemented using
- external functions, e.g.:
-\newline
-
-\newline
-
-\family typewriter
-#pragma SAVE
-\newline
-#pragma NOOVERLAY
-\newline
-void set_error(unsigned char errcd)
-\newline
-{
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-P3 = errcd;
-\newline
-}
-\newline
-#pragma RESTORE
-\newline
-
-\newline
-void some_isr () interrupt 2 using 1
-\newline
-{
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-...
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-set_error(10);
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-...
-
-\newline
-}
-\newline
-
-\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
-\family default
-In the above example the parameter
-\emph on
-errcd
-\emph default
- for the function
-\emph on
-set_error
-\emph default
- would be assigned to the overlayable segment if the #pragma\SpecialChar ~
-NOOVERLAY was
- not present, this could cause unpredictable runtime behavior when called
- from an ISR.
- The #pragma\SpecialChar ~
-NOOVERLAY ensures that the parameters and local variables for
- the function are NOT overlayed.
-\layout Subsection
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Interrupt Service Routines
\layout Standard
-SDCC allows interrupt service routines to be coded in C, with some extended
- keywords.
-\newline
-
-\newline
-
-\family typewriter
-void timer_isr (void) interrupt 2 using 1
-\newline
-{
-\newline
+path(argv[0])
+\backslash
..
-
-\newline
-}
-\newline
-
-\newline
+\backslash
+include
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family default
-The number following the
-\emph on
-interrupt
-\emph default
- keyword is the interrupt number this routine will service.
- The compiler will insert a call to this routine in the interrupt vector
- table for the interrupt number specified.
- The
-\emph on
-using
-\emph default
- keyword is used to tell the compiler to use the specified register bank
- (8051 specific) when generating code for this function.
- Note that when some function is called from an interrupt service routine
- it should be preceded by a #pragma\SpecialChar ~
-NOOVERLAY if it is not reentrant.
- A special note here, int (16 bit) and long (32 bit) integer division, multiplic
-ation & modulus operations are implemented using external support routines
- developed in ANSI-C, 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
-\emph on
- ---stack-auto
-\emph default
- option and the source file will need to be compiled using the
-\emph on
----int-long-ren
-\emph default
-t compiler option.
\layout Standard
-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
+
\emph on
-main
+$DATADIR/
\emph default
-.
-\layout Standard
-Interrupt Numbers and the corresponding address & descriptions for the Standard
- 8051 are listed below.
- SDCC will automatically adjust the interrupt vector table to the maximum
- interrupt number specified.
\newline
-\layout Standard
-
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="6" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0pt">
-<column alignment="center" valignment="top" leftline="true" width="0pt">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-Interrupt #
+\emph on
+$INCLUDE_DIR_SUFFIX
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Description
+/usr/local/share/sdcc/
+\newline
+include
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Vector Address
+(not on Win32)
\end_inset
</cell>
</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+</lyxtabular>
+
+\end_inset
+
+
+\newline
\layout Standard
+\noindent
+The option -
+\begin_inset ERT
+status Collapsed
-0
+\layout Standard
+
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-nostdinc disables the last two search paths.
+\newline
+
+\newline
+3.
+ Library files
+\newline
\layout Standard
-External 0
+With the exception of
+\begin_inset Quotes sld
\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
-0x0003
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+
+-L dir
+\begin_inset Quotes srd
+\end_inset
+
+ the
+\shape italic
+model
+\shape default
+ is auto-appended by the compiler (e.g.
+ small, large, z80, ds390 etc.).
+
+\newline
+
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features>
+<column alignment="block" valignment="top" leftline="true" width="1.7in">
+<column alignment="block" valignment="top" leftline="true" width="1.2in">
+<column alignment="block" valignment="top" leftline="true" rightline="true" width="1.2in">
+<row topline="true" bottomline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-1
+Search path
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Timer 0
+default
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-0x000B
+Win32 builds
\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" 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
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-External 1
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-0x0013
+-L dir
\end_inset
</cell>
-</row>
-<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-3
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Timer 1
+\backslash
+/
+\end_inset
+
+-L dir
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-0x001B
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-L dir
\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
-4
+$SDCC_LIB/
+\newline
+
+\emph on
+<model>
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Serial
+$SDCC_LIB/
+\newline
+
+\emph on
+<model>
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-0x0023
+$SDCC_LIB
+\backslash
+
+\newline
+
+\emph on
+<model>
\end_inset
</cell>
</row>
-</lyxtabular>
-
-\end_inset
+<row topline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
+$SDCC_HOME/
\newline
-\newline
-If the interrupt service routine is defined without
\emph on
-using
-\emph default
- a register bank or with register bank 0 (using 0), the compiler will save
- the registers used by itself on the stack upon entry and restore them at
- exit, however if such an interrupt service routine calls another function
- then the entire register bank will be saved on the stack.
- This scheme may be advantageous for small interrupt service routines which
- have low register usage.
-\layout Standard
+$PREFIX2DATA_DIR/
+\newline
+$LIB_DIR_SUFFIX/<model>
+\end_inset
+</cell>
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-If the interrupt service routine is defined to be using a specific register
- bank then only
-\emph on
-a, b & dptr
-\emph default
- are save 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.
- This scheme is recommended for larger interrupt service routines.
\layout Standard
-Calling other functions from an interrupt service routine is not recommended,
- avoid it if possible.
+$SDCC_HOME/
\newline
-
+share/sdcc/
\newline
-Also see the _naked modifier.
-\layout Subsection
+lib/
+\emph on
+<model>
+\end_inset
+</cell>
+<cell alignment="left" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Critical Functions
\layout Standard
+$SDCC_HOME
+\backslash
+lib
+\backslash
-\shape italic
-<TODO: this isn't implemented at all!>
-\shape default
+\emph on
\newline
+<model>
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+path(argv[0])/
\newline
-A special keyword may be associated with a function declaring it as
+
\emph on
-critical
+$BIN2DATADIR/
\emph default
-.
- SDCC will generate code to disable all interrupts upon entry to a critical
- function and enable them back before returning.
- Note that nesting critical functions may cause unpredictable results.
-\newline
-
-\size small
\newline
-\family typewriter
-\size default
-int foo () critical
-\newline
-{
-\newline
-...
-
-\newline
-...
-
-\newline
-}
-\newline
-
-\family default
-
-\newline
-The critical attribute maybe used with other attributes like
\emph on
-reentrant.
-\layout Subsection
+$LIB_DIR_SUFFIX/<model>
+\end_inset
+</cell>
+<cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Naked Functions
\layout Standard
-A special keyword may be associated with a function declaring it as
-\emph on
-_naked.
-
-\emph default
-The
-\emph on
-_naked
-\emph default
- function modifier attribute prevents the compiler from generating prologue
- and epilogue 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:
-\newline
-
-\newline
-
-\family typewriter
-data unsigned char counter;
+path(argv[0])/
\newline
-void simpleInterrupt(void) interrupt 1
-\newline
-{
+../sdcc/lib/
+\emph on
+<model>
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-counter++;
-\newline
-}
-\newline
-
-\newline
-void nakedInterrupt(void) interrupt 2 _naked
-\newline
-{
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_asm
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-inc\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_counter
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-reti\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-; MUST explicitly include ret in _naked function.
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm;
-\newline
-}
-\family default
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-For an 8051 target, the generated simpleInterrupt looks like:
-\newline
+\layout Standard
+
+path(argv[0])
+\backslash
\newline
+..
+\backslash
+lib
+\backslash
-\family typewriter
-_simpleIterrupt:
+\emph on
+<model>
\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
-\family default
-\newline
-
-\newline
-whereas nakedInterrupt looks like:
-\newline
-
-\newline
+\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
-_nakedInterrupt:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-inc\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_counter
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-reti\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-; MUST explicitly include ret(i) in _naked function.
-\family default
+\layout Standard
-\newline
+\emph on
+$DATADIR/
\newline
-While there is nothing preventing you from writing C code inside a _naked
- function, there are many ways to shoot yourself in the foot doing this,
- and it is recommended that you stick to inline assembler.
-\layout Subsection
-
-Functions using private banks
-\layout Standard
+$LIB_DIR_SUFFIX/<model>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-The
-\emph on
-using
-\emph default
- attribute (which tells the compiler to use a register bank other than the
- default bank zero) should only be applied to
-\emph on
-interrupt
-\emph default
- functions (see note 1 below).
- This will in most circumstances make the generated ISR code more efficient
- since it will not have to save registers on the stack.
\layout Standard
-The
-\emph on
-using
-\emph default
- attribute will have no effect on the generated code for a
+/usr/local/share/sdcc/
+\newline
+lib/
\emph on
-non-interrupt
-\emph default
- function (but may occasionally be useful anyway
-\begin_inset Foot
-collapsed true
+<model>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-possible exception: if a function is called ONLY from 'interrupt' functions
- using a particular bank, it can be declared with the same 'using' attribute
- as the calling 'interrupt' functions.
- For instance, if you have several ISRs using bank one, and all of them
- call memcpy(), it might make sense to create a specialized version of memcpy()
- 'using 1', since this would prevent the ISR from having to save bank zero
- to the stack on entry and switch to bank zero before calling the function
+(not on Win32)
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
\end_inset
-).
+
\newline
-\emph on
-(pending: I don't think this has been done yet)
-\layout Standard
+\layout Comment
-An
-\emph on
-interrupt
-\emph default
- function using a non-zero bank will assume that it can trash that register
- bank, and will not save it.
- Since high-priority interrupts can interrupt low-priority ones on the 8051
- and friends, this means that if a high-priority ISR
-\emph on
-using
-\emph default
- a particular bank occurs while processing a low-priority ISR
-\emph on
-using
-\emph default
- the same bank, terrible and bad things can happen.
- To prevent this, no single register bank should be
-\emph on
-used
-\emph default
- by both a high priority and a low priority ISR.
- This is probably most easily done by having all high priority ISRs use
- one bank and all low priority ISRs use another.
- If you have an ISR which can change priority at runtime, you're on your
- own: I suggest using the default bank zero and taking the small performance
- hit.
+Don't delete any of the stray spaces in the table above without checking
+ the HTML output (last line)!
\layout Standard
-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
- called functions use bank zero.
- It is very inefficient to call a function using a different, non-zero bank
- from an ISR.
-
-\layout Subsection
+\SpecialChar ~
+
+\newline
+The option -
+\begin_inset ERT
+status Collapsed
-Absolute Addressing
\layout Standard
-Data items can be assigned an absolute address with the
-\emph on
-at <address>
-\emph default
- keyword, in addition to a storage class, e.g.:
-\newline
+\backslash
+/
+\end_inset
-\newline
+-nostdlib disables the last two search paths.
+\layout Section
-\family typewriter
-xdata at 0x8000 unsigned char PORTA_8255 ;
-\newline
+Building SDCC
+\begin_inset LatexCommand \index{Building SDCC}
-\family default
+\end_inset
-\newline
-In the above example the PORTA_8255 will be allocated to the location 0x8000
- of the external ram.
- Note that this feature is provided to give the programmer access to
-\emph on
-memory mapped
-\emph default
- devices attached to the controller.
- The compiler does not actually reserve any space for variables declared
- in this way (they are implemented with an equate in the assembler).
- Thus it is left to the programmer to make sure there are no overlaps with
- other variables that are declared without the absolute address.
- The assembler listing file (.lst) and the linker output files (.rst) and
- (.map) are a good places to look for such overlaps.
-\newline
-\newline
-Absolute address can be specified for variables in all storage classes,
- e.g.:
-\newline
+\layout Subsection
-\newline
+Building SDCC on Linux
+\begin_inset LatexCommand \label{sub:Building-SDCC-on-Linux}
-\family typewriter
-bit at 0x02 bvar;
-\newline
+\end_inset
-\newline
-\family default
-The above example will allocate the variable at offset 0x02 in the bit-addressab
-le space.
- There is no real advantage to assigning absolute addresses to variables
- in this manner, unless you want strict control over all the variables allocated.
-\layout Subsection
+\layout Enumerate
-Startup Code
-\layout Standard
-The compiler inserts a call to the C routine
-\emph on
-_sdcc__external__startup()
-\series bold
-\emph default
-
+\series medium
+Download the source package
\series default
-at the start of the CODE area.
- This routine is in the runtime library.
- 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 Other wise 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.
-\layout Subsection
+ either from the SDCC CVS repository or from the nightly snapshots
+\series medium
+, it will be named something like sdcc
+\series default
+.src
+\series medium
+.t
+\series default
+ar.
+\series medium
+gz
+\series default
+
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
-Inline Assembler Code
-\layout Standard
+\end_inset
-SDCC allows the use of in-line assembler with a few restriction as regards
- labels.
- All labels defined within inline assembler code
-\emph on
-has 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
-\emph on
-per function
-\emph default
-\noun on
-)
-\noun default
.
- It is strongly recommended that each assembly instruction (including labels)
- be placed in a separate line (as the example shows).
- When the
-\emph on
----peep-asm
-\emph default
- command line option is used, the inline assembler code will be passed through
- the peephole optimizer.
- This might cause some unexpected changes in the inline assembler code.
- Please go throught the peephole optimizer rules defined in file
-\emph on
-SDCCpeeph.def
-\emph default
- carefully before using this option.
-\newline
+\layout Enumerate
-\newline
-\family typewriter
-_asm
-\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 ;
+\series medium
+Bring up a command line terminal, such as xterm.
+\layout Enumerate
+
+
+\series medium
+Unpack the file using a command like:
+\family sans
+\series bold
+"tar -xvzf sdcc.src.tar.gz
\family default
-\size small
+\series default
+"
+\series medium
+, this will create a sub-directory called sdcc with all of the sources.
+\layout Enumerate
-\newline
+Change directory into the main SDCC directory, for example type:
+\family sans
+\series bold
+"cd sdcc
+\series default
+".
+\layout Enumerate
-\newline
-\size default
-The inline assembler code can contain any valid code understood by the assembler
-, this includes any assembler directives and comment lines.
- The compiler does not do any validation of the code within the
-\family typewriter
-_asm ...
- _endasm;
+\series medium
+Type
+\family sans
+\series bold
+"./configure
\family default
- keyword pair.
-
-\newline
+\series default
+".
+ This configures the package for compilation on your system.
+\layout Enumerate
-\newline
-Inline assembler code cannot reference any C-Labels, however it can reference
- labels defined by the inline assembler, e.g.:
-\newline
-\newline
+\series medium
+Type
+\family sans
+\series bold
+"make
+\family default
+\series default
+"
+\series medium
+.
-\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 reference by inline assembler only)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-_endasm ;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-/* some more c code */
-\newline
-}
-\newline
+\series default
+ All of the source packages will compile, this can take a while.
+\layout Enumerate
-\newline
+\series medium
+Type
+\family sans
+\series bold
+"make install"
\family default
-In other words inline assembly code can access labels defined in inline
- assembly within the scope of the funtion.
-
-\layout Standard
+\series default
+ as root
+\series medium
+.
+
+\series default
+ This copies the binary executables, the include files, the libraries and
+ the documentation to the install directories.
+ Proceed with section
+\begin_inset LatexCommand \ref{sec:Testing-the-SDCC}
+
+\end_inset
-The same goes the other way, ie.
- labels defines in inline assembly CANNOT be accessed by C statements.
+.
\layout Subsection
-int (16 bit) and long (32 bit) Support
+Building SDCC on OSX 2.x
\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 optimations are used.
- The following files contain the described routine, all of them can be found
- in <installdir>/share/sdcc/lib.
+Follow the instruction for Linux.
\newline
\newline
+On OSX 2.x it was reported, that the default gcc (version 3.1 20020420 (prerelease
+)) fails to compile SDCC.
+ Fortunately there's also gcc 2.9.x installed, which works fine.
+ This compiler can be selected by running 'configure' with:
+\layout LyX-Code
-\emph on
-<pending: tabularise this>
-\emph default
+./configure CC=gcc2 CXX=g++2
+\layout Subsection
-\newline
+Cross compiling SDCC on Linux for Windows
+\layout Standard
-\newline
-_mulsint.c - signed 16 bit multiplication (calls _muluint)
-\newline
-_muluint.c - unsigned 16 bit multiplication
-\newline
-_divsint.c - signed 16 bit division (calls _divuint)
-\newline
-_divuint.c - unsigned 16 bit division
-\newline
-_modsint.c - signed 16 bit modulus (call _moduint)
-\newline
-_moduint.c - unsigned 16 bit modulus
-\newline
-_mulslong.c - signed 32 bit multiplication (calls _mululong)
-\newline
-_mululong.c - unsigned32 bit multiplication
-\newline
-_divslong.c - signed 32 division (calls _divulong)
-\newline
-_divulong.c - unsigned 32 division
-\newline
-_modslong.c - signed 32 bit modulus (calls _modulong)
-\newline
-_modulong.c - unsigned 32 bit modulus
-\size footnotesize
+With the Mingw32 gcc cross compiler it's easy to compile SDCC for Win32.
+ 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
+
+For building and installing a Cygwin executable follow the instructions
+ for Linux.
\newline
\newline
+On Cygwin a
+\begin_inset Quotes sld
+\end_inset
-\size default
-Since they are compiled as
-\emph on
-non-reentrant
-\emph default
-, interrupt 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
----stack-auto
-\emph default
- option, after which the source program will have to be compiled with
-\emph on
----int-long-rent
-\emph default
- option.
-\layout Subsection
-
-Floating Point Support
-\layout Standard
-
-SDCC supports IEEE (single precision 4bytes) floating point numbers.The floating
- point support routines are derived from gcc's floatlib.c and consists of
- the following routines:
-\newline
+native
+\begin_inset Quotes srd
+\end_inset
+ Win32-binary can be built, which will not need the Cygwin-DLL.
+ For the necessary 'configure' options see section 'configure options' or
+ the script 'sdcc/support/scripts/sdcc_cygwin_mingw32'.
\newline
-\emph on
-<pending: tabularise this>
-\emph default
-
\newline
+In order to install Cygwin on Windows download setup.exe from
+\begin_inset LatexCommand \url[www.cygwin.com]{http://www.cygwin.com/}
-\newline
-_fsadd.c - add floating point numbers
-\newline
-_fssub.c - subtract floating point numbers
-\newline
-_fsdiv.c - divide floating point numbers
-\newline
-_fsmul.c - multiply floating point numbers
-\newline
-_fs2uchar.c - convert floating point to unsigned char
-\newline
-_fs2char.c - convert floating point to signed char
-\newline
-_fs2uint.c - convert floating point to unsigned int
-\newline
-_fs2int.c - convert floating point to signed int
-\newline
-_fs2ulong.c - convert floating point to unsigned long
-\newline
-_fs2long.c - convert floating point to signed long
-\newline
-_uchar2fs.c - convert unsigned char to floating point
-\newline
-_char2fs.c - convert char to floating point number
-\newline
-_uint2fs.c - convert unsigned int to floating point
-\newline
-_int2fs.c - convert int to floating point numbers
-\newline
-_ulong2fs.c - convert unsigned long to floating point number
-\newline
-_long2fs.c - convert long to floating point number
-\size footnotesize
+\end_inset
-\newline
+.
+ Run it, set the
+\begin_inset Quotes sld
+\end_inset
-\newline
+default text file type
+\begin_inset Quotes srd
+\end_inset
-\size default
-Note if all these routines are used simultaneously the data space might
- overflow.
- For serious floating point usage it is strongly recommended that the large
- model be used.
-\layout Subsection
+ to
+\begin_inset Quotes sld
+\end_inset
-MCS51 Memory Models
-\layout Standard
+unix
+\begin_inset Quotes srd
+\end_inset
-SDCC allows two memory models for MCS51 code, small and large.
- 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 both small
- and large.
- The compiled library modules are contained in seperate directories as small
- and large so that you can link to either set.
-
-\layout Standard
+ and download/install at least the following packages.
+ Some packages are selected by default, others will be automatically selected
+ because of dependencies with the manually selected packages.
+ Never deselect these packages!
+\layout Itemize
-When the 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 functions).
- When the small model is used variables without storage class are allocated
- in the internal ram.
-\layout Standard
+flex
+\layout Itemize
-Judicious usage of the processor specific storage classes 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 strongly recommdended that the small model
- be used unless absolutely required.
-\layout Subsection
+bison
+\layout Itemize
-DS390 Memory Models
-\layout Standard
+gcc ; version 3.x is fine, no need to use the old 2.9x
+\layout Itemize
-The only model supported is Flat 24.
- 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
+binutils ; selected with gcc
+\layout Itemize
-\newline
-In older versions of the compiler, this option was used with the MCS51 code
- generator (
-\emph on
--mmcs51
-\emph default
-).
- Now, however, the '390 has it's own code generator, selected by the
-\emph on
--mds390
-\emph default
- switch.
-
-\newline
+make
+\layout Itemize
-\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
-, 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
+rxvt ; a nice console, which makes life much easier under windoze (see below)
+\layout Itemize
-\newline
-Like the
-\emph on
----model-large
-\emph default
- option, variables will by default be placed into the XDATA segment.
-
-\newline
+man ; not really needed for building SDCC, but you'll miss it sooner or
+ later
+\layout Itemize
-\newline
-Segments may be placed anywhere in the 4 meg address space using the usual
- ---*-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 Subsection
+less ; not really needed for building SDCC, but you'll miss it sooner or
+ later
+\layout Itemize
-Defines Created by the Compiler
+cvs ; only if you use CVS access
\layout Standard
-The compiler creates the following #defines.
+If you want to develop something you'll need:
\layout Itemize
-SDCC - this Symbol is always defined.
+python ; for the regression tests
\layout Itemize
-SDCC_mcs51 or SDCC_ds390 or SDCC_z80, etc - depending on the model used
- (e.g.: -mds390)
-\layout Itemize
+gdb ; the gnu debugger, together with the nice GUI
+\begin_inset Quotes sld
+\end_inset
-__mcs51 or __ds390 or __z80, etc - depending on the model used (e.g.
- -mz80)
-\layout Itemize
+insight
+\begin_inset Quotes srd
+\end_inset
-SDCC_STACK_AUTO - this symbol is defined when
-\emph on
----stack-auto
-\emph default
- option is used.
-\layout Itemize
-SDCC_MODEL_SMALL - when
-\emph on
----model-small
-\emph default
- is used.
\layout Itemize
-SDCC_MODEL_LARGE - when
-\emph on
----model-large
-\emph default
- is used.
+openssh ; to access the CF or commit changes
\layout Itemize
-SDCC_USE_XSTACK - when
-\emph on
----xstack
-\emph default
- option is used.
-\layout Itemize
+autoconf and autoconf-devel ; if you want to fight with 'configure', don't
+ use autoconf-stable!
+\layout Standard
-SDCC_STACK_TENBIT - when
-\emph on
--mds390
-\emph default
- is used
-\layout Itemize
+rxvt is a nice console with history.
+ Replace in your cygwin.bat the line
+\layout LyX-Code
-SDCC_MODEL_FLAT24 - when
-\emph on
--mds390
-\emph default
- is used
-\layout Section
+bash -
+\begin_inset ERT
+status Collapsed
-SDCC Technical Data
-\layout Subsection
+\layout Standard
-Optimizations
+\backslash
+/
+\end_inset
+
+-login -i
\layout Standard
-SDCC performs a host of standard optimizations in addition to some MCU specific
- optimizations.
-
-\layout Subsubsection
+with (one line):
+\layout LyX-Code
+
+rxvt -sl 1000 -fn "Lucida Console-12" -sr -cr red
+\layout LyX-Code
+
+ -bg black -fg white -geometry 100x65 -e bash -
+\begin_inset ERT
+status Collapsed
-Sub-expression Elimination
\layout Standard
-The compiler does local and global common subexpression elimination, e.g.:
-
-\newline
+\backslash
+/
+\end_inset
-\newline
+-login
+\layout Standard
-\family typewriter
-i = x + y + 1;
+Text selected with the mouse is automatically copied to the clipboard, pasting
+ works with shift-insert.
\newline
-j = x + y;
-\family default
\newline
+The other good tip is to make sure you have no //c/-style paths anywhere,
+ use /cygdrive/c/ instead.
+ Using // invokes a network lookup which is very slow.
+ If you think
+\begin_inset Quotes sld
+\end_inset
-\newline
-will be translated to
-\newline
+cygdrive
+\begin_inset Quotes srd
+\end_inset
-\newline
+ is too long, you can change it with e.g.
+\layout LyX-Code
-\family typewriter
-iTemp = x + y
-\newline
-i = iTemp + 1
-\newline
-j = iTemp
-\newline
+mount -s -u -c /mnt
+\layout Standard
-\family default
+SDCC sources use the unix line ending LF.
+ Life is much easier, if you store the source tree on a drive which is mounted
+ in binary mode.
+ And use an editor which can handle LF-only line endings.
+ Make sure not to commit files with windows line endings.
+ The tabulator spacing
+\begin_inset LatexCommand \index{tabulator spacing (8)}
-\newline
-Some subexpressions are not as obvious as the above example, e.g.:
-\newline
+\end_inset
-\newline
+ used in the project is 8.
+\layout Subsection
-\family typewriter
-a->b[i].c = 10;
-\newline
-a->b[i].d = 11;
-\family default
+Building SDCC Using Microsoft Visual C++ 6.0/NET (MSVC)
+\layout Standard
-\newline
-\newline
-In this case the address arithmetic a->b[i] will be computed only once;
- the equivalent code in C would be.
-\newline
+\series medium
+Download the source package
+\series default
+ either from the SDCC CVS repository or from the
+\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
-\newline
+\end_inset
-\family typewriter
-iTemp = a->b[i];
-\newline
-iTemp.c = 10;
-\newline
-iTemp.d = 11;
-\family default
+\series medium
+, it will be named something like sdcc
+\series default
+.src
+\series medium
+.tgz.
+
+\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).
+ The workspace name is 'sdcc.dsw'.
+ Please note that as it is now, all the executables are created in a folder
+ called sdcc
+\backslash
+bin_vc.
+ Once built you need to copy the executables from sdcc
+\backslash
+bin_vc to sdcc
+\backslash
+bin before running SDCC.
+
\newline
\newline
-The compiler will try to keep these temporary variables in registers.
-\layout Subsubsection
+In order to build SDCC with MSVC you need win32 executables of bison.exe,
+ flex.exe, and gawk.exe.
+ One good place to get them is
+\begin_inset LatexCommand \url[here]{http://unxutils.sourceforge.net}
-Dead-Code Elimination
-\layout Standard
+\end_inset
-\family typewriter
-int global;
\newline
-void f () {
+
\newline
-\SpecialChar ~
-\SpecialChar ~
-int i;
+Download the file UnxUtils
+\begin_inset LatexCommand \index{UnxUtils}
+
+\end_inset
+
+.zip.
+ Now you have to install the utilities and setup MSVC so it can locate the
+ required programs.
+ Here there are two alternatives (choose one!):
+\layout Enumerate
+
+The easy way:
\newline
-\SpecialChar ~
-\SpecialChar ~
-i = 1; \SpecialChar ~
-/* dead store */
+
\newline
-\SpecialChar ~
-\SpecialChar ~
-global = 1;\SpecialChar ~
-/* dead store */
+a) Extract UnxUtils.zip to your C:
+\backslash
+ hard disk PRESERVING the original paths, otherwise bison won't work.
+ (If you are using WinZip make certain that 'Use folder names' is selected)
\newline
-\SpecialChar ~
-\SpecialChar ~
-global = 2;
+
\newline
-\SpecialChar ~
-\SpecialChar ~
-return;
+b) In the Visual C++ IDE click Tools, Options, select the Directory tab,
+ in 'Show directories for:' select 'Executable files', and in the directories
+ window add a new path: 'C:
+\backslash
+user
+\backslash
+local
+\backslash
+wbin', click ok.
\newline
-\SpecialChar ~
-\SpecialChar ~
-global = 3;\SpecialChar ~
-/* unreachable */
+
\newline
-}
-\family default
+(As a side effect, you get a bunch of Unix utilities that could be useful,
+ such as diff and patch.)
+\layout Enumerate
+A more compact way:
\newline
\newline
-will be changed to
+This one avoids extracting a bunch of files you may not use, but requires
+ some extra work:
\newline
+\newline
+a) Create a directory were to put the tools needed, or use a directory already
+ present.
+ Say for example 'C:
+\backslash
+util'.
\newline
-\family typewriter
-int global; void f ()
\newline
-{
+b) Extract 'bison.exe', 'bison.hairy', 'bison.simple', 'flex.exe', and gawk.exe
+ to such directory WITHOUT preserving the original paths.
+ (If you are using WinZip make certain that 'Use folder names' is not selected)
\newline
-\SpecialChar ~
-\SpecialChar ~
-global = 2;
+
\newline
-\SpecialChar ~
-\SpecialChar ~
-return;
+c) Rename bison.exe to '_bison.exe'.
\newline
-}
-\layout Subsubsection
-Copy-Propagation
-\layout Standard
-
-
-\family typewriter
-int f() {
\newline
-\SpecialChar ~
-\SpecialChar ~
-int i, j;
+d) Create a batch file 'bison.bat' in 'C:
+\backslash
+util
+\backslash
+' and add these lines:
\newline
\SpecialChar ~
\SpecialChar ~
-i = 10;
+set BISON_SIMPLE=C:
+\backslash
+util
+\backslash
+bison.simple
\newline
\SpecialChar ~
\SpecialChar ~
-j = i;
+set BISON_HAIRY=C:
+\backslash
+util
+\backslash
+bison.hairy
\newline
\SpecialChar ~
\SpecialChar ~
-return j;
-\newline
-}
-\family default
-
-\newline
-
-\newline
-will be changed to
-\newline
-
+_bison %1 %2 %3 %4 %5 %6 %7 %8 %9
\newline
-\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
-}
+Steps 'c' and 'd' are needed because bison requires by default that the
+ files 'bison.simple' and 'bison.hairy' reside in some weird Unix directory,
+ '/usr/local/share/' I think.
+ So it is necessary to tell bison where those files are located if they
+ are not in such directory.
+ That is the function of the environment variables BISON_SIMPLE and BISON_HAIRY.
\newline
\newline
+e) In the Visual C++ IDE click Tools, Options, select the Directory tab,
+ in 'Show directories for:' select 'Executable files', and in the directories
+ window add a new path: 'c:
+\backslash
+util', click ok.
+ Note that you can use any other path instead of 'c:
+\backslash
+util', even the path where the Visual C++ tools are, probably: 'C:
+\backslash
+Program Files
+\backslash
+Microsoft Visual Studio
+\backslash
+Common
+\backslash
+Tools'.
+ So you don't have to execute step 'e' :)
+\layout Standard
-\family default
-Note: the dead stores created by this copy propagation will be eliminated
- by dead-code elimination.
-\layout Subsubsection
+That is it.
+ Open 'sdcc.dsw' in Visual Studio, click 'build all', when it finishes copy
+ the executables from sdcc
+\backslash
+bin_vc to sdcc
+\backslash
+bin, and you can compile using SDCC.
+\layout Subsection
-Loop Optimizations
-\layout Standard
+Building SDCC Using Borland
+\layout Enumerate
-Two types of loop optimizations are done by SDCC loop invariant lifting
- and strength reduction 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, loop induction optimizati
-on causes an increase in register pressure, which may cause unwanted spilling
- of other temporary variables into the stack / 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 ---noinduction
- option) or for a given function only using #pragma\SpecialChar ~
-NOINDUCTION.
-\newline
+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++).
+\layout Enumerate
-\newline
-Loop Invariant:
+If you modify any source files and need to rebuild, be aware that the dependenci
+es may not be correctly calculated.
+ The safest option is to delete all .obj files and run the build again.
+ From a Cygwin BASH prompt, this can easily be done with the command (be
+ sure you are in the sdcc directory):
\newline
\newline
-\family typewriter
-for (i = 0 ; i < 100 ; i ++)
-\newline
- \SpecialChar ~
- \SpecialChar ~
-f += k + l;
+\family sans
+\series bold
+find .
+
+\backslash
+( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
+\backslash
+) -print -exec rm {}
+\backslash
+;
\family default
+\series default
\newline
\newline
-changed to
+or on Windows NT/2000/XP from the command prompt with the command:
\newline
-\newline
+\family sans
+\series bold
-\family typewriter
-itemp = k + l;
-\newline
-for (i = 0; i < 100; i++)
\newline
-\SpecialChar ~
-\SpecialChar ~
-f += itemp;
+del /s *.obj *.lib *.rul
\family default
+\series default
+ from the sdcc directory.
+\layout Subsection
-\newline
-
-\newline
-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, this optimization substitutes an expression by a cheaper
- expression:
-\newline
+Windows Install Using a Binary Package
+\begin_inset LatexCommand \label{sub:Windows-Install}
-\newline
+\end_inset
-\family typewriter
-for (i=0;i < 100; i++)
-\newline
-\SpecialChar ~
-\SpecialChar ~
-ar[i*5] = i*3;
-\family default
-\newline
+\layout Enumerate
-\newline
-changed to
-\newline
+Download the binary package from
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
+
+\end_inset
+
+ and unpack it using your favorite unpacking tool (gunzip, WinZip, etc).
+ This should unpack to a group of sub-directories.
+ An example directory structure after unpacking the mingw32 package is:
+ c:
+\backslash
+sdcc
+\backslash
+bin for the executables, c:
+\backslash
+sdcc
+\backslash
+include and c:
+\backslash
+sdcc
+\backslash
+lib for the include and libraries.
+\layout Enumerate
+
+Adjust your environment variable PATH to include the location of the bin
+ directory or start sdcc using the full path.
+\layout Section
+
+Building the Documentation
+\layout Standard
+
+If the necessary tools (LyX, LaTeX, LaTeX2HTML) are installed it is as easy
+ as changing into the doc directory and typing
+\family sans
+\series bold
+
+\begin_inset Quotes srd
+\end_inset
+
+make
+\begin_inset Quotes srd
+\end_inset
-\newline
-\family typewriter
-itemp1 = 0;
-\newline
-itemp2 = 0;
-\newline
-for (i=0;i< 100;i++) {
-\newline
- \SpecialChar ~
- \SpecialChar ~
-ar[itemp1] = itemp2;
-\newline
- \SpecialChar ~
- \SpecialChar ~
-itemp1 += 5;
-\newline
- \SpecialChar ~
- \SpecialChar ~
-itemp2 += 3;
-\newline
-}
\family default
+\series default
+ there.
+ You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly
+x).
+ Using LyX
+\begin_inset LatexCommand \url{www.lyx.org}
-\newline
+\end_inset
-\newline
-The more expensive multiplication is changed to a less expensive addition.
-\layout Subsubsection
+ as editor this is straightforward.
+ If you want to avoid installing the tools you will have some success with
+ a bootable Knoppix CD
+\begin_inset LatexCommand \url{http://www.knoppix.net}
-Loop Reversing
+\end_inset
+
+.
+ Prebuilt documentation in html and pdf format is available from
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
+
+\end_inset
+
+.
+\layout Section
+
+Reading the Documentation
\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
+Currently reading the document in pdf format is recommended, as for unknown
+ reason the hyperlinks are working there whereas in the html version they
+ are not
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+If you should know why please drop us a note
\end_inset
-decrement and jump if not zero
-\begin_inset Quotes erd
+.
+ You'll find the pdf version at
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
+
\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).
+.
+\newline
+This documentation is in some aspects different from a commercial documentation:
+
\layout Itemize
-The 'for' loop is of the form
-\newline
+It tries to document SDCC for several processor architectures in one document
+ (commercially these probably would be separate documents/products).
+ This document
+\begin_inset LatexCommand \index{Status of documentation}
-\newline
+\end_inset
-\family typewriter
-for (<symbol> = <expression> ; <sym> [< | <=] <expression> ; [<sym>++ |
- <sym> += 1])
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-<for body>
+ currently matches SDCC for mcs51 and DS390 best and does give too few informati
+on about f.e.
+ Z80, PIC14, PIC16 and HC08.
\layout Itemize
-The <for body> does not contain
-\begin_inset Quotes eld
+There are many references pointing away from this documentation.
+ Don't let this distract you.
+ If there f.e.
+ was a reference like
+\begin_inset LatexCommand \url{www.opencores.org}
+
\end_inset
-continue
-\begin_inset Quotes erd
+ together with a statement
+\begin_inset Quotes sld
\end_inset
- or 'break
-\begin_inset Quotes erd
+some processors which are targetted by SDCC can be implemented in a
+\emph on
+f
+\emph default
+ield
+\emph on
+p
+\emph default
+rogrammable
+\emph on
+g
+\emph default
+ate
+\emph on
+a
+\emph default
+rray
+\begin_inset LatexCommand \index{fpga (field programmable gate array)}
+
\end_inset
-.
-\layout Itemize
-All goto's are contained within the loop.
-\layout Itemize
+\begin_inset Quotes srd
+\end_inset
-No function calls within the loop.
+ we expect you to have a quick look there and come back.
+ If you read this you are on the right track.
\layout Itemize
-The loop control variable <sym> is not assigned any value within the loop
+Some sections attribute more space to problems, restrictions and warnings
+ than to the solution.
\layout Itemize
-The loop control variable does NOT participate in any arithmetic operation
- within the loop.
+The installation section and the section about the debugger is intimidating.
\layout Itemize
-There are NO switch statements in the loop.
-\layout Subsubsection
+There are still lots of typos and there are more different writing styles
+ than pictures.
+\layout Section
+
+Testing the SDCC Compiler
+\begin_inset LatexCommand \label{sec:Testing-the-SDCC}
+
+\end_inset
+
-Algebraic Simplifications
\layout Standard
-SDCC does numerous algebraic simplifications, the following is a small sub-set
- of these optimizations.
+The first thing you should do after installing your SDCC compiler is to
+ see if it runs.
+ Type
+\family sans
+\series bold
+"sdcc -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-version"
+\begin_inset LatexCommand \index{version}
+
+\end_inset
+
+
+\family default
+\series default
+ at the prompt, and the program should run and tell you the version.
+ If it doesn't run, or gives a message about not finding sdcc program, then
+ you need to check over your installation.
+ Make sure that the sdcc bin directory is in your executable search path
+ defined by the PATH environment setting (
+\series medium
+see
+\series default
+section
+\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
+
+\end_inset
+
+\SpecialChar ~
+
+\series medium
+Install trouble-shooting for suggestions
+\series default
+).
+ Make sure that the sdcc program is in the bin folder, if not perhaps something
+ did not install correctly.
\newline
\newline
+\series medium
+SDCC
+\series default
+is commonly installed as described in section
+\begin_inset Quotes sld
+\end_inset
+
+Install and search paths
+\begin_inset Quotes srd
+\end_inset
+
+.
+\newline
+
+\newline
+
+\series medium
+Make sure the compiler works on a very simple example.
+ Type in the following test.c program using your favorite
+\series default
+ASCII
+\series medium
+editor:
+\layout Verse
+
+
\family typewriter
-i = j + 0 ; /* changed to */ i = j;
+char test;
+\newline
+
\newline
-i /= 2; /* changed to */ i >>= 1;
+void main(void) {
\newline
-i = j - j ; /* changed to */ i = 0;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+test=0;
\newline
-i = j / 1 ; /* changed to */ i = j;
+}
+\layout Standard
+
+
+\series medium
+Compile this using the following command:
+\family sans
+\series bold
+"sdcc -c test.c".
+
\family default
+\series default
+
+\series medium
+If all goes well, the compiler will generate a test.asm and test.rel file.
+ Congratulations, you've just compiled your first program with SDCC.
+ We used the -c option to tell SDCC not to link the generated code, just
+ to keep things simple for this step.
+\series default
\newline
\newline
-Note the subexpressions given above are generally introduced by macro expansions
- or as a result of copy/constant propagation.
-\layout Subsubsection
-'switch' Statements
-\layout Standard
-
-SDCC changes switch statements to jump tables when the following conditions
- are true.
+\series medium
+The next step is to try it with the linker.
+ Type in
+\family sans
+\series bold
+"sdcc test.c
+\family default
+\series default
+"
+\series medium
+.
+ If all goes well the compiler will link with the libraries and produce
+ a test.ihx output file.
+ If this step fails
+\series default
-\layout Itemize
+\series medium
+(no test.ihx, and the linker generates warnings), then the problem is most
+ likely that
+\series default
+SDCC
+\series medium
+ cannot find the
+\series default
+/
+\series medium
+usr/local/share/sdcc/lib directory
+\series default
+
+\series medium
+(see
+\series default
+section
+\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
+
+\end_inset
+
+\SpecialChar ~
+
+\series medium
+Install trouble-shooting for suggestions).
+\series default
-The case labels are in numerical sequence, the labels need not be in order,
- and the starting number need not be one or zero.
\newline
\newline
-\family typewriter
-switch(i) {\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-switch (i) {
+\series medium
+The final test is to ensure
+\series default
+SDCC
+\series medium
+ can use the
+\series default
+standard
+\series medium
+ header files and libraries.
+ Edit test.c and change it to the following:
+\layout Verse
+
+
+\family typewriter
+#include <string.h>
\newline
-case 4:...
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-case 1: ...
-
+
\newline
-case 5:...
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-case 2: ...
-
+char str1[10];
\newline
-case 3:...
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-case 3: ...
-
+
\newline
-case 6:...
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-case 4: ...
-
+void main(void) {
\newline
-}\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-}
+\SpecialChar ~
+\SpecialChar ~
+strcpy(str1, "testing");
\newline
+}
+\layout Standard
-\newline
+\series medium
+Compile this by typing
+\family sans
+\series bold
+"sdcc test.c"
\family default
-Both the above switch statements will be implemented using a jump-table.
-\layout Itemize
+\series medium
+.
+ This should generate a test.ihx output file, and it should give no warnings
+ such as not finding the string.h file.
+ If it cannot find the string.h file, then the problem is that
+\series default
+SDCC
+\series medium
+ cannot find the /usr/local/share/sdcc/include directory
+\series default
+
+\series medium
+(see the
+\series default
+section
+\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
-The number of case labels is at least three, since it takes two conditional
- statements to handle the boundary conditions.
-\layout Itemize
+\end_inset
+
+\SpecialChar ~
+
+\series medium
+Install trouble-shooting section for suggestions).
+
+\series default
+ Use option
+\series bold
+-
+\begin_inset ERT
+status Collapsed
-The number of case labels is less than 84, since each label takes 3 bytes
- and a jump-table can be utmost 256 bytes long.
-
\layout Standard
-Switch statements which have gaps in the numeric sequence or those that
- have more that 84 case labels can be split into more than one switch statement
- for efficient code generation, e.g.:
-\newline
+\backslash
+/
+\end_inset
-\newline
+-print-search-dirs
+\series default
-\family typewriter
-switch (i) {
-\newline
-case 1: ...
-
-\newline
-case 2: ...
-
-\newline
-case 3: ...
-
-\newline
-case 4: ...
-
-\newline
-case 9: ...
-
-\newline
-case 10: ...
-
-\newline
-case 11: ...
-
-\newline
-case 12: ...
-
-\newline
-}
-\family default
+\begin_inset LatexCommand \index{-\/-print-search-dirs}
-\newline
+\end_inset
-\newline
-If the above switch statement is broken down into two switch statements
-\newline
+ to find exactly where SDCC is looking for the include and lib files.
+\layout Section
-\newline
+Install Trouble-shooting
+\begin_inset LatexCommand \label{sub:Install-Trouble-shooting}
-\family typewriter
-switch (i) {
-\newline
-case 1: ...
-
-\newline
-case 2: ...
-
-\newline
-case 3: ...
-
-\newline
-case 4: ...
-
-\newline
-}
+\end_inset
+
+
+\begin_inset LatexCommand \index{Install trouble-shooting}
+
+\end_inset
+
+
+\layout Subsection
+
+If SDCC does not build correctly
+\layout Standard
+
+A thing to try is starting from scratch by unpacking the .tgz source package
+ again in an empty directory.
+ Configure it like:
\newline
\newline
+\family sans
+\series bold
+./configure 2>&1 | tee configure.log
\family default
-and
-\family typewriter
+\series default
\newline
\newline
-switch (i) {
-\newline
-case 9: \SpecialChar ~
-...
-
-\newline
-case 10: ...
-
-\newline
-case 11: ...
-
-\newline
-case 12:\SpecialChar ~
-...
-
-\newline
-}
+and build it like:
\newline
\newline
+\family sans
+\series bold
+make 2>&1 | tee make.log
\family default
-then both the switch statements will be implemented using jump-tables whereas
- the unmodified switch statement will not be.
-\layout Subsubsection
+\series default
-Bit-shifting Operations.
-\layout Standard
+\newline
-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.:
\newline
+If anything goes wrong, you can review the log files to locate the problem.
+ Or a relevant part of this can be attached to an email that could be helpful
+ when requesting help from the mailing list.
+\layout Subsection
-\family typewriter
+What the
+\begin_inset Quotes sld
+\end_inset
-\newline
-unsigned char i;
-\newline
-...
-
-\newline
-i>>= 4;
-\newline
-...
-\newline
+./configure
+\begin_inset Quotes srd
+\end_inset
-\family default
+ does
+\layout Standard
-\newline
-generates the following code:
-\newline
+The
+\begin_inset Quotes sld
+\end_inset
-\family typewriter
+./configure
+\begin_inset Quotes srd
+\end_inset
-\newline
-mov a,_i
-\newline
-swap a
-\newline
-anl a,#0x0f
-\newline
-mov _i,a
-\family default
+ command is a script that analyzes your system and performs some configuration
+ to ensure the source package compiles on your system.
+ It will take a few minutes to run, and will compile a few tests to determine
+ what compiler features are installed.
+\layout Subsection
-\newline
+What the
+\begin_inset Quotes sld
+\end_inset
-\newline
-In general SDCC will never setup a loop if the shift count is known.
- Another example:
-\newline
+make
+\begin_inset Quotes srd
+\end_inset
-\newline
+ does
+\layout Standard
-\family typewriter
-unsigned int i;
-\newline
-...
-
-\newline
-i >>= 9;
-\newline
-...
-\family default
+This runs the GNU make tool, which automatically compiles all the source
+ packages into the final installed binary executables.
+\layout Subsection
-\newline
+What the
+\begin_inset Quotes sld
+\end_inset
-\newline
-will generate:
-\newline
+make install
+\begin_inset Quotes erd
+\end_inset
-\newline
+ command does.
+\layout Standard
-\family typewriter
-mov a,(_i + 1)
-\newline
-mov (_i + 1),#0x00
-\newline
-clr c
-\newline
-rrc a
-\newline
-mov _i,a
-\family default
+This will install the compiler, other executables libraries and include
+ files into the appropriate directories.
+ See sections
+\begin_inset LatexCommand \ref{sub:Install-paths}
-\newline
+\end_inset
+
+,\SpecialChar ~
+
+\begin_inset LatexCommand \ref{sub:Search-Paths}
+\end_inset
+
+\SpecialChar ~
+about install and search paths.
\newline
-Note that SDCC stores numbers in little-endian format (i.e.
- lowest order first).
-\layout Subsubsection
+On most systems you will need super-user privileges to do this.
+\layout Section
-Bit-rotation
+Components of SDCC
\layout Standard
-A special case of the bit-shift operation is bit rotation, SDCC recognizes
- the following expression to be a left bit-rotation:
+SDCC is not just a compiler, but a collection of tools by various developers.
+ These include linkers, assemblers, simulators and other components.
+ Here is a summary of some of the components.
+ Note that the included simulator and assembler have separate documentation
+ which you can find in the source package in their respective directories.
+ As SDCC grows to include support for other processors, other packages from
+ various developers are included and may have their own sets of documentation.
\newline
\newline
-
-\family typewriter
-unsigned char i;
+You might want to look at the files which are installed in <installdir>.
+ At the time of this writing, we find the following programs for gcc-builds:
\newline
-...
\newline
-i = ((i << 1) | (i >> 7));
-\family default
+In <installdir>/bin:
+\layout Itemize
-\newline
-...
-\newline
+sdcc - The compiler.
+\layout Itemize
-\newline
-will generate the following code:
-\newline
+sdcpp - The C preprocessor.
+\layout Itemize
-\newline
+asx8051 - The assembler for 8051 type processors.
+\layout Itemize
-\family typewriter
-mov a,_i
-\newline
-rl a
-\newline
-mov _i,a
-\family default
+as-z80
+\series bold
+,
+\series default
+as-gbz80 - The Z80 and GameBoy Z80 assemblers.
+\layout Itemize
-\newline
+aslink -The linker for 8051 type processors.
+\layout Itemize
-\newline
-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.:
-\newline
+link-z80
+\series bold
+,
+\series default
+link-gbz80 - The Z80 and GameBoy Z80 linkers.
+\layout Itemize
-\newline
+s51 - The ucSim 8051 simulator.
+\layout Itemize
-\family typewriter
-i = ((i >> 7) | (i << 1)); /* left-bit rotation */
-\layout Subsubsection
+sdcdb - The source debugger.
+\layout Itemize
-Highest Order Bit
+packihx - A tool to pack (compress) Intel hex files.
\layout Standard
-It is frequently required to obtain the highest order bit of an integral
- type (long, int, short or char types).
- SDCC recognizes the following expression to yield the highest order bit
- and generates optimized code for it, e.g.:
-\newline
+In <installdir>/share/sdcc/include
+\layout Itemize
-\newline
-
-\family typewriter
-unsigned int gint;
-\newline
+the include files
+\layout Standard
-\newline
-foo () {
-\newline
-unsigned char hob;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-\SpecialChar ~
-\SpecialChar ~
-hob = (gint >> 15) & 1;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-..
-
-\newline
-}
-\family default
+In <installdir>/share/sdcc/lib
+\layout Itemize
-\newline
+the subdirs src and small, large, z80, gbz80 and ds390 with the precompiled
+ relocatables.
+\layout Standard
-\newline
-will generate the following code:
-\newline
+In <installdir>/share/sdcc/doc
+\layout Itemize
-\family typewriter
+the documentation
+\layout Standard
+
+As development for other processors proceeds, this list will expand to include
+ executables to support processors like AVR, PIC, etc.
+\layout Subsection
+
+sdcc - The Compiler
+\layout Standard
+
+This is the actual compiler, it in turn uses the c-preprocessor and invokes
+ the assembler and linkage editor.
+\layout Subsection
+
+sdcpp - The C-Preprocessor
+\layout Standard
+
+The preprocessor
+\begin_inset LatexCommand \index{sdcpp (preprocessor)}
+
+\end_inset
+
+ is a modified version of the GNU preprocessor.
+ The C preprocessor is used to pull in #include sources, process #ifdef
+ statements, #defines and so on.
+\layout Subsection
+
+as
+\emph on
+xxxx
+\emph default
+, aslink, link-
+\emph on
+xxx
+\emph default
+ - The Assemblers and Linkage Editors
+\layout Standard
+
+This is retargettable assembler & linkage editor, it was developed by Alan
+ Baldwin.
+ John Hartman created the version for 8051, and I (Sandeep) have made some
+ enhancements and bug fixes for it to work properly with SDCC.
+\layout Subsection
+
+s51 - The Simulator
+\layout Standard
+
+S51
+\begin_inset LatexCommand \index{s51}
+
+\end_inset
+
+ is a freeware, opensource simulator developed by Daniel Drotos (
+\begin_inset LatexCommand \url{mailto:drdani@mazsola.iit.uni-miskolc.hu}
+
+\end_inset
+
+).
+ The simulator is built as part of the build process.
+ For more information visit Daniel's web site at:
+\begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
+
+\end_inset
+
+.
+ It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
+ XA51 family.
+\layout Subsection
+
+sdcdb - Source Level Debugger
+\layout Standard
+
+Sdcdb
+\begin_inset LatexCommand \index{sdcdb (debugger)}
+
+\end_inset
+
+ is the companion source level debugger.
+ More about sdcdb in section
+\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
+
+\end_inset
+
+.
+ The current version of the debugger uses Daniel's Simulator S51
+\begin_inset LatexCommand \index{s51}
+
+\end_inset
+
+, but can be easily changed to use other simulators.
+
+\layout Chapter
+
+Using SDCC
+\layout Section
+
+Compiling
+\layout Subsection
+
+Single Source File Projects
+\layout Standard
+
+For single source file 8051 projects the process is very simple.
+ Compile your programs with the following command
+\family sans
+\series bold
+"sdcc sourcefile.c".
+
+\family default
+\series default
+ This will compile, assemble and link your source file.
+ Output files are as follows:
+\layout Itemize
+
+sourcefile.asm
+\begin_inset LatexCommand \index{<file>.asm}
+
+\end_inset
+
+ - Assembler source
+\begin_inset LatexCommand \index{Assembler source}
+
+\end_inset
+
+ file created by the compiler
+\layout Itemize
+
+sourcefile.lst
+\begin_inset LatexCommand \index{<file>.lst}
+
+\end_inset
+
+ - Assembler listing
+\begin_inset LatexCommand \index{Assembler listing}
+
+\end_inset
+
+ file created by the Assembler
+\layout Itemize
+
+sourcefile.rst
+\begin_inset LatexCommand \index{<file>.rst}
+
+\end_inset
+
+ - Assembler listing
+\begin_inset LatexCommand \index{Assembler listing}
+
+\end_inset
+
+ file updated with linkedit information, created by linkage editor
+\layout Itemize
+
+sourcefile.sym
+\begin_inset LatexCommand \index{<file>.sym}
+
+\end_inset
+
+ - symbol listing
+\begin_inset LatexCommand \index{Symbol listing}
+
+\end_inset
+
+ for the sourcefile, created by the assembler
+\layout Itemize
+
+sourcefile.rel
+\begin_inset LatexCommand \index{<file>.rel}
+
+\end_inset
+
+ or sourcefile.o
+\begin_inset LatexCommand \index{<file>.o}
+
+\end_inset
+
+ - Object file
+\begin_inset LatexCommand \index{Object file}
+
+\end_inset
+
+ created by the assembler, input to Linkage editor
+\layout Itemize
+
+sourcefile.map
+\begin_inset LatexCommand \index{<file>.map}
+
+\end_inset
+
+ - The memory map
+\begin_inset LatexCommand \index{Memory map}
+
+\end_inset
+
+ for the load module, created by the Linker
+\layout Itemize
+
+sourcefile.mem
+\begin_inset LatexCommand \index{<file>.mem}
+
+\end_inset
+
+ - A file with a summary of the memory usage
+\layout Itemize
+
+sourcefile.ihx
+\begin_inset LatexCommand \index{<file>.ihx}
+
+\end_inset
+
+ - The load module in Intel hex format
+\begin_inset LatexCommand \index{Intel hex format}
+
+\end_inset
+
+ (you can select the Motorola S19 format
+\begin_inset LatexCommand \index{Motorola S19 format}
+
+\end_inset
+
+ with -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-out-fmt-s19
+\begin_inset LatexCommand \index{-\/-out-fmt-s19}
+
+\end_inset
+
+.
+ If you need another format you might want to use
+\family sans
+\shape italic
+objdump
+\family default
+\shape default
+
+\begin_inset LatexCommand \index{objdump (tool)}
+
+\end_inset
+
+ or
+\family sans
+\shape italic
+ srecord
+\family default
+\shape default
+
+\begin_inset LatexCommand \index{srecord (tool)}
+
+\end_inset
+
+).
+ Both formats are documented in the documentation of srecord
+\begin_inset LatexCommand \index{srecord (tool)}
+
+\end_inset
+
+
+\layout Itemize
+
+sourcefile.adb
+\begin_inset LatexCommand \index{<file>.adb}
+
+\end_inset
+
+ - An intermediate file containing debug information needed to create the
+ .cdb file (with -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+)
+\layout Itemize
+
+sourcefile.cdb
+\begin_inset LatexCommand \index{<file>.cdb}
+
+\end_inset
+
+ - An optional file (with -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug) containing debug information.
+ The format is documented in cdbfileformat.pdf.
+\layout Itemize
+
+sourcefile.
+ - (no extension)
+\begin_inset LatexCommand \index{<file> (no extension)}
+
+\end_inset
+
+ An optional AOMF or AOMF51
+\begin_inset LatexCommand \index{AOMF, AOMF51}
+
+\end_inset
+
+ file containing debug information (generated with option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug).
+ The (Intel)
+\emph on
+ a
+\emph default
+bsolute
+\emph on
+o
+\emph default
+bject
+\emph on
+m
+\emph default
+odule
+\emph on
+f
+\emph default
+ormat is commonly used by third party tools (debuggers
+\begin_inset LatexCommand \index{Debugger}
+
+\end_inset
+
+, simulators, emulators)
+\layout Itemize
+
+sourcefile.dump*
+\begin_inset LatexCommand \index{<file>.dump*}
+
+\end_inset
+
+ - Dump file to debug the compiler it self (generated with option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpall) (see section
+\begin_inset LatexCommand \ref{sub:Intermediate-Dump-Options}
+
+\end_inset
-\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 ~
- 61 ;\SpecialChar ~
- hob.c 7
-\newline
-\SpecialChar ~
-\SpecialChar ~
- 000A E5*01\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
+ and section
+\begin_inset LatexCommand \ref{sub:The-anatomy-of}
+
+\end_inset
+
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 62\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
- a,(_gint + 1)
+
+\begin_inset Quotes sld
+\end_inset
+
+Anatomy of the compiler
+\begin_inset Quotes srd
+\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
-\SpecialChar ~
-\SpecialChar ~
- 000C 33\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 ~
- rlc\SpecialChar ~
- a
+
\newline
-\SpecialChar ~
-\SpecialChar ~
- 000D E4\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 64\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- clr\SpecialChar ~
- a
+foo1.c (contains some functions)
\newline
-\SpecialChar ~
-\SpecialChar ~
- 000E 13\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 65\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- rrc\SpecialChar ~
- a
+foo2.c (contains some more functions)
\newline
-\SpecialChar ~
-\SpecialChar ~
- 000F F5*02\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- 66\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- mov\SpecialChar ~
- _foo_hob_1_1,a
+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}
+
+\end_inset
+
+
+\newline
+
+\newline
+Alternatively,
+\emph on
+foomain.c
+\emph default
+can be separately compiled as well:
+\family sans
+\series bold
+
+\newline
+
+\newline
+sdcc\SpecialChar ~
+-c\SpecialChar ~
+foomain.c
+\newline
+sdcc foomain.rel foo1.rel foo2.rel
+\newline
+
+\newline
+
+\family default
+\series default
+The file containing the
+\emph on
+main()
+\emph default
+ function
+\emph on
+
+\emph default
+\noun on
+must
+\noun default
+ be the
+\noun on
+first
+\noun default
+ file specified in the command line, since the linkage editor processes
+ file in the order they are presented to it.
+ The linker is invoked from SDCC using a script file with extension .lnk
+\begin_inset LatexCommand \index{<file>.lnk}
+
+\end_inset
+
+.
+ You can view this file to troubleshoot linking problems such as those arising
+ from missing libraries.
+\layout Subsection
+
+Projects with Additional Libraries
+\begin_inset LatexCommand \index{Libraries}
+
+\end_inset
+
+
+\layout Standard
+
+Some reusable routines may be compiled into a library, see the documentation
+ for the assembler and linkage editor (which are in <installdir>/share/sdcc/doc)
+ for how to create a
+\emph on
+.lib
+\begin_inset LatexCommand \index{<file>.lib}
+
+\end_inset
+
+
+\emph default
+ library file.
+ Libraries created in this manner can be included in the command line.
+ Make sure you include the -L <library-path> option to tell the linker where
+ to look for these files if they are not in the current directory.
+ Here is an example, assuming you have the source file
+\emph on
+foomain.c
+\emph default
+ and a library
+\emph on
+ foolib.lib
+\emph default
+ in the directory
+\emph on
+mylib
+\emph default
+ (if that is not the same as your current project):
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcc foomain.c foolib.lib -L mylib
+\newline
+
+\newline
+
+\family default
+\series default
+Note here that
+\emph on
+ mylib
+\emph default
+ must be an absolute path name.
+\newline
+
+\newline
+The most efficient way to use libraries is to keep separate modules in separate
+ source files.
+ The lib file now should name all the modules.rel
+\begin_inset LatexCommand \index{<file>.rel}
+
+\end_inset
+
+ files.
+ For an example see the standard library file
+\emph on
+libsdcc.lib
+\emph default
+ in the directory <installdir>/share/lib/small.
+\layout Subsection
+
+Using sdcclib to Create and Manage Libraries
+\begin_inset LatexCommand \index{sdcclib}
+
+\end_inset
+
+
+\layout Standard
+
+Alternatively, instead of having a .rel file for each entry on the library
+ file as described in the preceding section, sdcclib can be used to embed
+ all the modules belonging to such library in the library file itself.
+ This results in a larger library file, but it greatly reduces the number
+ of disk files accessed by the linker.
+ Additionally, the packed library file contains an index of all include
+ modules and symbols that significantly speeds up the linking process.
+ To display a list of options supported by sdcclib type:
+\newline
+
+\layout Standard
+
+
+\family sans
+\series bold
+sdcclib -?
+\begin_inset LatexCommand \index{sdcclib}
+
+\end_inset
+
+
+\newline
+
+\newline
+
+\family default
+\series default
+To create a new library file, start by compiling all the required modules.
+ For example:
+\newline
+
+\layout Standard
+
+
+\series bold
+sdcc -c _divsint.c
+\layout Standard
+
+
+\series bold
+sdcc -c _divuint.c
+\layout Standard
+
+
+\series bold
+sdcc -c _modsint.c
+\layout Standard
+
+
+\series bold
+sdcc -c _moduint.c
+\layout Standard
+
+
+\series bold
+sdcc -c _mulint.c
+\newline
+
+\layout Standard
+
+This will create files _divsint.rel, _divuint.rel, _modsint.rel, _moduint.rel,
+ and _mulint.rel.
+ The next step is to add the .rel files to the library file:
+\newline
+
+\layout Standard
+
+
+\series bold
+sdcclib libint.lib _divsint.rel
+\begin_inset LatexCommand \index{sdcclib}
+
+\end_inset
+
+
+\layout Standard
+
+
+\series bold
+sdcclib libint.lib _divuint.rel
+\layout Standard
+
+
+\series bold
+sdcclib libint.lib _modsint.rel
+\layout Standard
+
+
+\series bold
+sdcclib libint.lib _moduint.rel
+\layout Standard
+
+
+\series bold
+sdcclib libint.lib _mulint.rel
+\series default
+
+\newline
+
+\layout Standard
+
+If the file already exists in the library, it will be replaced.
+ To see what modules and symbols are included in the library, options -s
+ and -m are available.
+ For example:
+\newline
+
+\newline
+
+\series bold
+sdcclib -s libint.lib
+\begin_inset LatexCommand \index{sdcclib}
+
+\end_inset
+
+
+\newline
+_divsint.rel:
+\layout Standard
+
+
+\series bold
+__divsint_a_1_1
+\layout Standard
+
+
+\series bold
+__divsint_PARM_2
+\layout Standard
+
+
+\series bold
+__divsint
+\newline
+_divuint.rel:
+\layout Standard
+
+
+\series bold
+__divuint_a_1_1
+\layout Standard
+
+
+\series bold
+__divuint_PARM_2
+\layout Standard
+
+
+\series bold
+__divuint_reste_1_1
+\layout Standard
+
+
+\series bold
+__divuint_count_1_1
+\layout Standard
+
+
+\series bold
+__divuint
+\newline
+_modsint.rel:
+\layout Standard
+
+
+\series bold
+__modsint_a_1_1
+\layout Standard
+
+
+\series bold
+__modsint_PARM_2
+\layout Standard
+
+
+\series bold
+__modsint
+\newline
+_moduint.rel:
+\layout Standard
+
+
+\series bold
+__moduint_a_1_1
+\layout Standard
+
+
+\series bold
+__moduint_PARM_2
+\layout Standard
+
+
+\series bold
+__moduint_count_1_1
+\layout Standard
+
+
+\series bold
+__moduint
+\newline
+_mulint.rel:
+\layout Standard
+
+
+\series bold
+__mulint_PARM_2
+\layout Standard
+
+
+\series bold
+__mulint
+\newline
+
+\layout Standard
+
+If the source files are compiled using --debug, the corresponding debug
+ information file .adb will be include in the library file as well.
+ The library files created with sdcclib are plain text files, so they can
+ be viewed with a text editor.
+ It is not recomended to modify a library file created with sdcclib using
+ a text editor, as there are file indexes numbers located accross the file
+ used by the linker to quickly locate the required module to link.
+ Once a .rel file (as well as a .adb file) is added to a library using sdcclib,
+ it can be safely deleted, since all the information required for linking
+ is embedded in the library file itself.
+ Library files created using sdcclib are used as described in the preceding
+ sections.
+\layout Section
+
+Command Line Options
+\begin_inset LatexCommand \index{Command Line Options}
+
+\end_inset
+
+
+\layout Subsection
+
+Processor Selection Options
+\begin_inset LatexCommand \index{Options processor selection}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Processor selection options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mmcs51
+\begin_inset LatexCommand \index{-mmcs51}
+
+\end_inset
+
+
+\series default
+ Generate code for the Intel MCS51
+\begin_inset LatexCommand \index{MCS51}
+
+\end_inset
+
+ family of processors.
+ This is the default processor target.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mds390
+\begin_inset LatexCommand \index{-mds390}
+
+\end_inset
+
+
+\series default
+ Generate code for the Dallas DS80C390
+\begin_inset LatexCommand \index{DS80C390}
+
+\end_inset
+
+ processor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mds400
+\begin_inset LatexCommand \index{-mds400}
+
+\end_inset
+
+
+\series default
+ Generate code for the Dallas DS80C400
+\begin_inset LatexCommand \index{DS80C400}
+
+\end_inset
+
+ processor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mhc08
+\begin_inset LatexCommand \index{-mhc08}
+
+\end_inset
+
+
+\series default
+ Generate code for the Motorola HC08
+\begin_inset LatexCommand \index{HC08}
+
+\end_inset
+
+ family of processors (added Oct 2003).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mz80
+\begin_inset LatexCommand \index{-mz80}
+
+\end_inset
+
+
+\series default
+ Generate code for the Zilog Z80
+\begin_inset LatexCommand \index{Z80}
+
+\end_inset
+
+ family of processors.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mgbz80
+\begin_inset LatexCommand \index{-mgbz80}
+
+\end_inset
+
+
+\series default
+ Generate code for the GameBoy Z80
+\begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
+
+\end_inset
+
+ processor (Not actively maintained).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mavr
+\begin_inset LatexCommand \index{-mavr}
+
+\end_inset
+
+
+\series default
+ Generate code for the Atmel AVR
+\begin_inset LatexCommand \index{AVR}
+
+\end_inset
+
+ processor (In development, not complete).
+ AVR users should probably have a look at avr-gcc
+\begin_inset LatexCommand \url{ http://savannah.nongnu.org/download/avr-libc/snapshots/}
+
+\end_inset
+
+.
+\layout Comment
+
+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.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mpic14
+\begin_inset LatexCommand \index{-mpic14}
+
+\end_inset
+
+
+\series default
+ Generate code for the Microchip PIC 14
+\begin_inset LatexCommand \index{PIC14}
+
+\end_inset
+
+-bit processors (p16f84 and variants.
+ In development, not complete).
+\layout Comment
+
+p16f627 p16f628 p16f84 p16f873 p16f877?
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mpic16
+\begin_inset LatexCommand \index{-mpic16}
+
+\end_inset
+
+
+\series default
+ Generate code for the Microchip PIC 16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+-bit processors (p18f452 and variants.
+ In development, not complete).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mtlcs900h
+\series default
+ Generate code for the Toshiba TLCS-900H
+\begin_inset LatexCommand \index{TLCS-900H}
+
+\end_inset
+
+ processor (Not maintained, not complete).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-mxa51
+\begin_inset LatexCommand \index{-mxa51}
+
+\end_inset
+
+
+\series default
+ Generate code for the Phillips XA51
+\begin_inset LatexCommand \index{XA51}
+
+\end_inset
+
+ processor (Not maintained, not complete).
+\layout Subsection
+
+Preprocessor Options
+\begin_inset LatexCommand \index{Options preprocessor}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Preprocessor options}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{sdcpp (preprocessor)}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-I<path>
+\begin_inset LatexCommand \index{-I<path>}
+
+\end_inset
+
+
+\series default
+ The additional location where the pre processor will look for <..h> or
+\begin_inset Quotes eld
+\end_inset
+
+..h
+\begin_inset Quotes erd
+\end_inset
+
+ files.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-D<macro[=value]>
+\begin_inset LatexCommand \index{-D<macro[=value]>}
+
+\end_inset
+
+
+\series default
+ Command line definition of macros.
+ Passed to the preprocessor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-M
+\begin_inset LatexCommand \index{-M}
+
+\end_inset
+
+
+\series default
+ Tell the preprocessor to output a rule suitable for make describing the
+ dependencies of each object file.
+ For each source file, the preprocessor outputs one make-rule whose target
+ is the object file name for that source file and whose dependencies are
+ all the files `#include'd in it.
+ This rule may be a single line or may be continued with `
+\backslash
+'-newline if it is long.
+ The list of rules is printed on standard output instead of the preprocessed
+ C program.
+ `-M' implies `-E
+\begin_inset LatexCommand \index{-E}
+
+\end_inset
+
+'.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-C
+\begin_inset LatexCommand \index{-C}
+
+\end_inset
+
+
+\series default
+ Tell the preprocessor not to discard comments.
+ Used with the `-E' option.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-MM
+\begin_inset LatexCommand \index{-MM}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Like `-M' but the output mentions only the user header files included with
+ `#include
+\begin_inset Quotes eld
+\end_inset
+
+file"'.
+ System header files included with `#include <file>' are omitted.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-Aquestion(answer)
+\begin_inset LatexCommand \index{-Aquestion(answer)}
+
+\end_inset
+
+
+\series default
+ Assert the answer answer for question, in case it is tested with a preprocessor
+ conditional such as `#if #question(answer)'.
+ `-A-' disables the standard assertions that normally describe the target
+ machine.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-Umacro
+\begin_inset LatexCommand \index{-Umacro}
+
+\end_inset
+
+
+\series default
+ Undefine macro macro.
+ `-U' options are evaluated after all `-D' options, but before any `-include'
+ and `-imacros' options.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-dM
+\begin_inset LatexCommand \index{-dM}
+
+\end_inset
+
+
+\series default
+ Tell the preprocessor to output only a list of the macro definitions that
+ are in effect at the end of preprocessing.
+ Used with the `-E' option.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-dD
+\begin_inset LatexCommand \index{-dD}
+
+\end_inset
+
+
+\series default
+ Tell the preprocessor to pass all macro definitions into the output, in
+ their proper sequence in the rest of the output.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-dN
+\begin_inset LatexCommand \index{-dN}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Like `-dD' except that the macro arguments and contents are omitted.
+ Only `#define name' is included in the output.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-Wp\SpecialChar ~
+preprocessorOption[,preprocessorOption]
+\series default
+
+\begin_inset LatexCommand \index{-Wp preprocessorOption[,preprocessorOption]}
+
+\end_inset
+
+...
+ Pass the preprocessorOption to the preprocessor
+\family typewriter
+sdcpp
+\family default
+
+\begin_inset LatexCommand \index{sdcpp (preprocessor)}
+
+\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
+\begin_inset LatexCommand \htmlurl{http://www.gnu.org/software/gcc/onlinedocs/}
+
+\end_inset
+
+.
+\layout Subsection
+
+Linker Options
+\begin_inset LatexCommand \index{Options linker}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Linker options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-L\SpecialChar ~
+-
+\series default
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+-lib-path
+\begin_inset LatexCommand \index{-\/-lib-path <path>}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{-L -\/-lib-path}
+
+\end_inset
+
+
+\series default
+\SpecialChar ~
+<absolute path to additional libraries> This option is passed to the linkage
+ editor's additional libraries
+\begin_inset LatexCommand \index{Libraries}
+
+\end_inset
+
+ search path.
+ The path name must be absolute.
+ Additional library files may be specified in the command line.
+ See section Compiling programs for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xram-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-xram-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> The start location of the external ram
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+, default value is 0.
+ The value entered can be in Hexadecimal or Decimal format, e.g.: -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xram-loc 0x8000 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xram-loc 32768.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-code-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> The start location of the code
+\begin_inset LatexCommand \index{code}
+
+\end_inset
+
+ segment, default value 0.
+ Note when this option is used the interrupt vector table is also relocated
+ to the given address.
+ The value entered can be in Hexadecimal or Decimal format, e.g.: -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-loc 0x8000 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-loc 32768.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-stack-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> By default the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ is placed after the data segment.
+ Using this option the stack can be placed anywhere in the internal memory
+ space of the 8051.
+ The value entered can be in Hexadecimal or Decimal format, e.g.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc 0x20 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc 32.
+ Since the sp register is incremented before a push or call, the initial
+ sp will be set to one byte prior the provided value.
+ The provided value should not overlap any other memory areas such as used
+ register banks or the data segment and with enough space for the current
+ application.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-data-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> The start location of the internal ram data
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\end_inset
+
+ segment.
+ The value entered can be in Hexadecimal or Decimal format, eg.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc 0x20 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc 32.
+ (By default, the start location of the internal ram data segment is set
+ as low as possible in memory, taking into account the used register banks
+ and the bit segment at address 0x20.
+ For example if register banks 0 and 1 are used without bit variables, the
+ data segment will be set, if -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc is not used, to location 0x10.)
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-idata-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-idata-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> The start location of the indirectly addressable internal ram
+\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ of the 8051, default value is 0x80.
+ The value entered can be in Hexadecimal or Decimal format, eg.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-idata-loc 0x88 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-idata-loc 136.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-bit-loc
+\series default
+\SpecialChar ~
+<Value> The start location of the bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ addressable internal ram of the 8051.
+ This is
+\emph on
+not
+\emph default
+ implemented yet.
+ Instead an option can be passed directly to the linker: -Wl\SpecialChar ~
+-bBSEG=<Value>.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-out-fmt-ihx
+\begin_inset LatexCommand \index{-\/-out-fmt-ihx}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+The linker output (final object code) is in Intel Hex format.
+\begin_inset LatexCommand \index{Intel hex format}
+
+\end_inset
+
+ This is the default option.
+ The format itself is documented in the documentation of srecord
+\begin_inset LatexCommand \index{srecord (tool)}
+
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-out-fmt-s19
+\begin_inset LatexCommand \index{-\/-out-fmt-s19}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+The linker output (final object code) is in Motorola S19 format
+\begin_inset LatexCommand \index{Motorola S19 format}
+
+\end_inset
+
+.
+ The format itself is documented in the documentation of srecord.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-Wl\SpecialChar ~
+linkOption[,linkOption]
+\series default
+
+\begin_inset LatexCommand \index{-Wl linkOption[,linkOption]}
+
+\end_inset
+
+...
+ Pass the linkOption to the linker.
+ See file sdcc/as/doc/asxhtm.html for more on linker options.
+\layout Subsection
+
+MCS51 Options
+\begin_inset LatexCommand \index{Options MCS51}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{MCS51 options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-small
+\begin_inset LatexCommand \index{-\/-model-small}
+
+\end_inset
+
+
+\series default
+\size large
+\emph on
+
+\size default
+\emph default
+Generate code for Small Model programs, see section Memory Models for more
+ details.
+ This is the default model.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-large
+\begin_inset LatexCommand \index{-\/-model-large}
+
+\end_inset
+
+
+\series default
+ Generate code for Large model programs, see section Memory Models for more
+ details.
+ If this option is used all source files in the project have to be compiled
+ with this option.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack
+\begin_inset LatexCommand \index{-\/-xstack}
+
+\end_inset
+
+
+\series default
+ Uses a pseudo stack in the first 256 bytes in the external ram for allocating
+ variables and passing parameters.
+ See section
+\begin_inset LatexCommand \ref{sub:External-Stack}
+
+\end_inset
+
+\SpecialChar ~
+ External Stack for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-iram-size
+\series default
+\SpecialChar ~
+<Value>
+\begin_inset LatexCommand \index{-\/-iram-size <Value>}
+
+\end_inset
+
+ Causes the linker to check if the internal ram usage is within limits of
+ the given value.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xram-size
+\series default
+\SpecialChar ~
+<Value>
+\begin_inset LatexCommand \index{-\/-xram-size <Value>}
+
+\end_inset
+
+ Causes the linker to check if the external ram usage is within limits of
+ the given value.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-size
+\series default
+\SpecialChar ~
+<Value>
+\begin_inset LatexCommand \index{-\/-code-size <Value>}
+
+\end_inset
+
+ Causes the linker to check if the code memory usage is within limits of
+ the given value.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-size
+\series default
+\SpecialChar ~
+<Value>
+\begin_inset LatexCommand \index{-\/-stack-size <Value>}
+
+\end_inset
+
+ Causes the linker to check if there is at minimum <Value> bytes for stack.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pack-iram
+\series default
+\SpecialChar ~
+
+\begin_inset LatexCommand \index{-\/-pack-iram}
+
+\end_inset
+
+ Causes the linker use unused register banks for data variables or stack.
+\layout Subsection
+
+DS390 / DS400 Options
+\begin_inset LatexCommand \index{Options DS390}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{DS390 options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-flat24
+\series default
+
+\begin_inset LatexCommand \index{-\/-model-flat24}
+
+\end_inset
+
+
+\size large
+\emph on
+
+\size default
+\emph default
+Generate 24-bit flat mode code.
+ This is the one and only that the ds390 code generator supports right now
+ and is default when using
+\emph on
+-mds390
+\emph default
+.
+ See section Memory Models for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-protect-sp-update
+\begin_inset LatexCommand \index{-\/-protect-sp-update}
+
+\end_inset
+
+
+\series default
+ disable interrupts during ESP:SP updates.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-10bit
+\series default
+
+\begin_inset LatexCommand \index{-\/-stack-10bit}
+
+\end_inset
+
+ Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
+ This is the one and only that the ds390 code generator supports right now
+ and is default when using
+\emph on
+-mds390
+\emph default
+.
+ In this mode, the stack is located in the lower 1K of the internal RAM,
+ which is mapped to 0x400000.
+ Note that the support is incomplete, since it still uses a single byte
+ as the stack pointer.
+ This means that only the lower 256 bytes of the potential 1K stack space
+ will actually be used.
+ However, this does allow you to reclaim the precious 256 bytes of low RAM
+ for use for the DATA and IDATA segments.
+ The compiler will not generate any code to put the processor into 10 bit
+ stack mode.
+ It is important to ensure that the processor is in this mode before calling
+ any re-entrant functions compiled with this option.
+ In principle, this should work with the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\emph default
+ option, but that has not been tested.
+ It is incompatible with the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack
+\begin_inset LatexCommand \index{-\/-xstack}
+
+\end_inset
+
+
+\emph default
+ option.
+ It also only makes sense if the processor is in 24 bit contiguous addressing
+ mode (see the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-flat24 option
+\emph default
+).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-probe
+\begin_inset LatexCommand \index{-\/-stack-probe}
+
+\end_inset
+
+
+\series default
+ insert call to function __stack_probe at each function prologue.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-tini-libid
+\begin_inset LatexCommand \index{-\/-tini-libid}
+
+\end_inset
+
+
+\series default
+ <nnnn> LibraryID used in -mTININative.
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-use-accelerator
+\begin_inset LatexCommand \index{-\/-use-accelerator}
+
+\end_inset
+
+
+\series default
+ generate code for DS390 Arithmetic Accelerator.
+
+\layout Subsection
+
+Z80 Options
+\begin_inset LatexCommand \index{Options Z80}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Z80 options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-callee-saves-bc
+\series default
+
+\begin_inset LatexCommand \index{-\/-callee-saves-bc}
+
+\end_inset
+
+
+\size large
+\emph on
+
+\size default
+\emph default
+Force a called function to always save BC.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-std-crt0
+\series default
+
+\begin_inset LatexCommand \index{-\/-no-std-crt0}
+
+\end_inset
+
+ When linking, skip the standard crt0.o object file.
+ You must provide your own crt0.o for your system when linking.
+
+\layout Subsection
+
+Optimization Options
+\begin_inset LatexCommand \index{Options optimization}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Optimization options}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-nogcse
+\begin_inset LatexCommand \index{-\/-nogcse}
+
+\end_inset
+
+
+\series default
+ Will not do global subexpression elimination, this option may be used when
+ the compiler creates undesirably large stack/data spaces to store compiler
+ temporaries.
+ A warning message will be generated when this happens and the compiler
+ will indicate the number of extra bytes it allocated.
+ It is recommended that this option NOT be used, #pragma\SpecialChar ~
+nogcse
+\begin_inset LatexCommand \index{\#pragma nogcse}
+
+\end_inset
+
+ can be used to turn off global subexpression elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
+
+\end_inset
+
+ for a given function only.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-noinvariant
+\begin_inset LatexCommand \index{-\/-noinvariant}
+
+\end_inset
+
+
+\series default
+ Will not do loop invariant optimizations, this may be turned off for reasons
+ explained for the previous option.
+ For more details of loop optimizations performed see section Loop Invariants.
+ It is recommended that this option NOT be used, #pragma\SpecialChar ~
+noinvariant
+\begin_inset LatexCommand \index{\#pragma noinvariant}
+
+\end_inset
+
+ can be used to turn off invariant optimizations for a given function only.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-noinduction
+\begin_inset LatexCommand \index{-\/-noinduction}
+
+\end_inset
+
+
+\series default
+ Will not do loop induction optimizations, see section strength reduction
+ for more details.
+ It is recommended that this option is NOT used, #pragma\SpecialChar ~
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
+
+\end_inset
+
+ can be used to turn off induction optimizations for a given function only.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-nojtbound
+\begin_inset LatexCommand \index{-\/-nojtbound}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+ Will not generate boundary condition check when switch statements
+\begin_inset LatexCommand \index{switch statement}
+
+\end_inset
+
+ are implemented using jump-tables.
+ See section
+\begin_inset LatexCommand \ref{sub:'switch'-Statements}
+
+\end_inset
+
+\SpecialChar ~
+Switch Statements for more details.
+ It is recommended that this option is NOT used, #pragma\SpecialChar ~
+nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
+
+\end_inset
+
+ can be used to turn off boundary checking for jump tables for a given function
+ only.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-noloopreverse
+\begin_inset LatexCommand \index{-\/-noloopreverse}
+
+\end_inset
+
+
+\series default
+\size large
+
+\size default
+Will not do loop reversal
+\begin_inset LatexCommand \index{Loop reversing}
+
+\end_inset
+
+optimization.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-
+\series bold
+nolabelopt
+\series default
+
+\begin_inset LatexCommand \index{-\/-nolabelopt }
+
+\end_inset
+
+Will not optimize labels (makes the dumpfiles more readable).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-xinit-opt
+\begin_inset LatexCommand \index{-\/-no-xinit-opt}
+
+\end_inset
+
+
+\series default
+ Will not memcpy initialized data from code space into xdata space.
+ This saves a few bytes in code space if you don't have initialized data.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-nooverlay
+\begin_inset LatexCommand \index{-\/-nooverlay}
+
+\end_inset
+
+
+\series default
+ The compiler will not overlay parameters and local variables of any function,
+ see section Parameters and local variables for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-peep
+\begin_inset LatexCommand \index{-\/-no-peep}
+
+\end_inset
+
+
+\series default
+ Disable peep-hole optimization.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-file
+\series default
+
+\begin_inset LatexCommand \index{-\/-peep-file}
+
+\end_inset
+
+\SpecialChar ~
+<filename> This option can be used to use additional rules to be used by
+ the peep hole optimizer.
+ See section
+\begin_inset LatexCommand \ref{sub:Peephole-Optimizer}
+
+\end_inset
+
+\SpecialChar ~
+Peep Hole optimizations for details on how to write these rules.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-asm
+\begin_inset LatexCommand \index{-\/-peep-asm}
+
+\end_inset
+
+
+\series default
+ Pass the inline assembler code through the peep hole optimizer.
+ This can cause unexpected changes to inline assembler code, please go through
+ the peephole optimizer
+\begin_inset LatexCommand \index{Peephole optimizer}
+
+\end_inset
+
+ rules defined in the source file tree '<target>/peeph.def' before using
+ this option.
+\layout Subsection
+
+Other Options
+\begin_inset LatexCommand \index{Options other}
+
+\end_inset
+
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-c\SpecialChar ~
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-compile-only
+\begin_inset LatexCommand \index{-\/-compile-only}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{-c -\/-compile-only}
+
+\end_inset
+
+
+\series default
+ will compile and assemble the source, but will not call the linkage editor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\series default
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+-c1mode
+\begin_inset LatexCommand \index{-\/-c1mode}
+
+\end_inset
+
+
+\series default
+ reads the preprocessed source from standard input and compiles it.
+ The file name for the assembler output must be specified using the -o option.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-E
+\begin_inset LatexCommand \index{-E}
+
+\end_inset
+
+
+\series default
+ Run only the C preprocessor.
+ Preprocess all the C source files specified and output the results to standard
+ output.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-o\SpecialChar ~
+<path/file>
+\begin_inset LatexCommand \index{-o <path/file>}
+
+\end_inset
+
+
+\series default
+The output path resp.
+ file where everything will be placed.
+ If the parameter is a path, it must have a trailing slash (or backslash
+ for the Windows binaries) to be recognized as a path.
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\series default
+\size large
+\emph on
+
+\size default
+\emph default
+All functions in the source file will be compiled as
+\emph on
+reentrant
+\emph default
+
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+, i.e.
+ the parameters and local variables will be allocated on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+.
+ see section Parameters and Local Variables for more details.
+ If this option is used all source files in the project should be compiled
+ with this option.
+
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-callee-saves
+\begin_inset LatexCommand \index{-\/-callee-saves}
+
+\end_inset
+
+ function1[,function2][,function3]....
+
+\series default
+ The compiler by default uses a caller saves convention for register saving
+ across function calls, however this can cause unnecessary register pushing
+ & popping when calling small functions from larger functions.
+ This option can be used to switch the register saving convention for the
+ function names specified.
+ The compiler will not save registers when calling these functions, no extra
+ code will be generated at the entry & exit (function prologue
+\series bold
+
+\begin_inset LatexCommand \index{function prologue}
+
+\end_inset
+
+
+\series default
+ & epilogue
+\series bold
+
+\begin_inset LatexCommand \index{function epilogue}
+
+\end_inset
+
+
+\series default
+) 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) will be able
+ to determine the appropriate scheme to use for each function call.
+ DO NOT use this option for built-in functions such as _mulint..., if this
+ option is used for a library function the appropriate library function
+ needs to be recompiled with the same option.
+ If the project consists of multiple source files then all the source file
+ should be compiled with the same -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-callee-saves option string.
+ Also see #pragma\SpecialChar ~
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
+
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+When this option is used the compiler will generate debug information.
+ The debug information collected in a file with .cdb extension can be used
+ with the SDCDB.
+ For more information see documentation for SDCDB.
+ Another file with no extension contains debug information in AOMF or AOMF51
+\begin_inset LatexCommand \index{AOMF, AOMF51}
+
+\end_inset
+
+ format which is commonly used by third party tools.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-S
+\begin_inset LatexCommand \index{-S}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Stop after the stage of compilation proper; do not assemble.
+ The output is an assembler code file for the input file specified.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-int-long-reent
+\begin_inset LatexCommand \index{-\/-int-long-reent}
+
+\end_inset
+
+
+\series default
+ Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
+ Note by default these libraries are compiled as non-reentrant.
+ See section Installation for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-cyclomatic
+\begin_inset LatexCommand \index{-\/-cyclomatic}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+This option will cause the compiler to generate an information message for
+ each function in the source file.
+ The message contains some
+\emph on
+important
+\emph default
+ information about the function.
+ The number of edges and nodes the compiler detected in the control flow
+ graph of the function, and most importantly the
+\emph on
+cyclomatic complexity
+\begin_inset LatexCommand \index{Cyclomatic complexity}
+
+\end_inset
+
+
+\emph default
+ see section on Cyclomatic Complexity for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-float-reent
+\begin_inset LatexCommand \index{-\/-float-reent}
+
+\end_inset
+
+
+\series default
+ Floating point library is compiled as reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+.
+ See section Installation for more details.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-main-return
+\begin_inset LatexCommand \index{-\/-main-return}
+
+\end_inset
+
+
+\series default
+ This option can be used when the code generated is called by a monitor
+ program.
+ The compiler will generate a 'ret' upon return from the 'main'
+\begin_inset LatexCommand \index{main return}
+
+\end_inset
+
+ function.
+ The default setting is to lock up i.e.
+ generate a '
+\family typewriter
+sjmp .
+\family default
+'.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-nostdincl
+\begin_inset LatexCommand \index{-\/-nostdincl}
+
+\end_inset
+
+
+\series default
+ This will prevent the compiler from passing on the default include path
+ to the preprocessor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-nostdlib
+\begin_inset LatexCommand \index{-\/-nostdlib}
+
+\end_inset
+
+
+\series default
+ This will prevent the compiler from passing on the default library
+\begin_inset LatexCommand \index{Libraries}
+
+\end_inset
+
+ path to the linker.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-verbose
+\begin_inset LatexCommand \index{-\/-verbose}
+
+\end_inset
+
+
+\series default
+ Shows the various actions the compiler is performing.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-V
+\begin_inset LatexCommand \index{-V}
+
+\end_inset
+
+
+\series default
+ Shows the actual commands the compiler is executing.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-c-code-in-asm
+\begin_inset LatexCommand \index{-\/-no-c-code-in-asm}
+
+\end_inset
+
+
+\series default
+ Hides your ugly and inefficient c-code from the asm file, so you can always
+ blame the compiler :).
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-i-code-in-asm
+\begin_inset LatexCommand \index{-\/-i-code-in-asm}
+
+\end_inset
+
+
+\series default
+ Include i-codes in the asm file.
+ Sounds like noise but is most helpful for debugging the compiler itself.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-less-pedantic
+\begin_inset LatexCommand \index{-\/-less-pedantic}
+
+\end_inset
+
+
+\series default
+ Disable some of the more pedantic warnings
+\begin_inset LatexCommand \index{Warnings}
+
+\end_inset
+
+ (jwk burps: please be more specific here, please!).
+ If you want rather more than less warnings you should consider using a
+ separate tool dedicated to syntax checking like splint
+\begin_inset LatexCommand \url{www.splint.org}
+
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-print-search-dirs
+\begin_inset LatexCommand \index{-\/-print-search-dirs}
+
+\end_inset
+
+
+\series default
+ Display the directories in the compiler's search path
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-vc
+\begin_inset LatexCommand \index{-\/-vc}
+
+\end_inset
+
+
+\series default
+ Display errors and warnings using MSVC style, so you can use SDCC with
+ visual studio.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-use-stdout
+\begin_inset LatexCommand \index{-\/-use-stdout}
+
+\end_inset
+
+
+\series default
+ Send errors and warnings to stdout instead of stderr.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-Wa\SpecialChar ~
+asmOption[,asmOption]
+\series default
+
+\begin_inset LatexCommand \index{-Wa asmOption[,asmOption]}
+
+\end_inset
+
+...
+ Pass the asmOption to the assembler
+\begin_inset LatexCommand \index{Options assembler}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler options}
+
+\end_inset
+
+.
+ See file sdcc/as/doc/asxhtm.html for assembler options.
+\layout Subsection
+
+Intermediate Dump Options
+\begin_inset LatexCommand \label{sub:Intermediate-Dump-Options}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Options intermediate dump}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Intermediate dump options}
+
+\end_inset
+
+
+\layout Standard
+
+The following options are provided for the purpose of retargetting and debugging
+ the compiler.
+ These provided a means to dump the intermediate code (iCode
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+) generated by the compiler in human readable form at various stages of
+ the compilation process.
+ More on iCodes see chapter
+\begin_inset LatexCommand \ref{sub:The-anatomy-of}
+
+\end_inset
+
+
+\begin_inset Quotes srd
+\end_inset
+
+The anatomy of the compiler
+\begin_inset Quotes srd
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpraw
+\begin_inset LatexCommand \index{-\/-dumpraw}
+
+\end_inset
+
+
+\series default
+ This option will cause the compiler to dump the intermediate code into
+ a file of named
+\emph on
+<source filename>.dumpraw
+\emph default
+ just after the intermediate code has been generated for a function, i.e.
+ before any optimizations are done.
+ The basic blocks
+\begin_inset LatexCommand \index{Basic blocks}
+
+\end_inset
+
+ at this stage ordered in the depth first number, so they may not be in
+ sequence of execution.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpgcse
+\begin_inset LatexCommand \index{-\/-dumpgcse}
+
+\end_inset
+
+
+\series default
+ Will create a dump of iCode's, after global subexpression elimination
+\begin_inset LatexCommand \index{Global subexpression elimination}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumpgcse.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpdeadcode
+\begin_inset LatexCommand \index{-\/-dumpdeadcode}
+
+\end_inset
+
+
+\series default
+ Will create a dump of iCode's, after deadcode elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumpdeadcode.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumploop
+\begin_inset LatexCommand \index{-\/-dumploop}
+
+\end_inset
+
+
+\series default
+\size large
+
+\size default
+Will create a dump of iCode's, after loop optimizations
+\begin_inset LatexCommand \index{Loop optimization}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumploop.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumprange
+\begin_inset LatexCommand \index{-\/-dumprange}
+
+\end_inset
+
+
+\series default
+\size large
+
+\size default
+Will create a dump of iCode's, after live range analysis
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumprange.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumlrange
+\begin_inset LatexCommand \index{-\/-dumlrange}
+
+\end_inset
+
+
+\series default
+ Will dump the life ranges
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+ for all symbols.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpregassign
+\begin_inset LatexCommand \index{-\/-dumpregassign}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+Will create a dump of iCode's, after register assignment
+\begin_inset LatexCommand \index{Register assignment}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumprassgn.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumplrange
+\begin_inset LatexCommand \index{-\/-dumplrange}
+
+\end_inset
+
+
+\series default
+ Will create a dump of the live ranges of iTemp's
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Will cause all the above mentioned dumps to be created.
+\layout Subsection
+
+Redirecting output on Windows Shells
+\layout Standard
+
+By default SDCC writes it's error messages to
+\begin_inset Quotes sld
+\end_inset
+
+standard error
+\begin_inset Quotes srd
+\end_inset
+
+.
+ To force all messages to
+\begin_inset Quotes sld
+\end_inset
+
+standard output
+\begin_inset Quotes srd
+\end_inset
+
+ use
+\series bold
+-
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-
+\series default
+use-stdout
+\begin_inset LatexCommand \index{-\/-use-stdout}
+
+\end_inset
+
+.
+ Additionally, if you happen to have visual studio installed in your windows
+ machine, you can use it to compile your sources using a custom build and
+ the SDCC -
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\emph default
+-vc
+\begin_inset LatexCommand \index{-\/-vc}
+
+\end_inset
+
+ option.
+ Something like this should work:
+\newline
+
+\newline
+
+\series bold
+c:
+\backslash
+sdcc
+\backslash
+bin
+\backslash
+sdcc.exe -
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-vc -
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-model-large -c $(InputPath)
+\layout Section
+
+Environment variables
+\begin_inset LatexCommand \index{Environment variables}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC recognizes the following environment variables:
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+SDCC_LEAVE_SIGNALS
+\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
+
+\end_inset
+
+
+\series default
+ SDCC installs a signal handler
+\begin_inset LatexCommand \index{signal handler}
+
+\end_inset
+
+ to be able to delete temporary files after an user break (^C) or an exception.
+ If this environment variable is set, SDCC won't install the signal handler
+ in order to be able to debug SDCC.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+TMP,\SpecialChar ~
+TEMP,\SpecialChar ~
+TMPDIR
+\begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
+
+\end_inset
+
+
+\series default
+ Path, where temporary files will be created.
+ The order of the variables is the search order.
+ In a standard *nix environment these variables are not set, and there's
+ no need to set them.
+ On Windows it's recommended to set one of them.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+SDCC_HOME
+\begin_inset LatexCommand \index{SDCC\_HOME}
+
+\end_inset
+
+
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Install-paths}
+
+\end_inset
+
+\SpecialChar ~
+
+\begin_inset Quotes sld
+\end_inset
+
+ Install Paths
+\begin_inset Quotes srd
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+SDCC_INCLUDE
+\begin_inset LatexCommand \index{SDCC\_INCLUDE}
+
+\end_inset
+
+
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Search-Paths}
+
+\end_inset
+
+\SpecialChar ~
+
+\begin_inset Quotes sld
+\end_inset
+
+Search Paths
+\begin_inset Quotes srd
+\end_inset
+
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+SDCC_LIB
+\begin_inset LatexCommand \index{SDCC\_LIB}
+
+\end_inset
+
+
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Search-Paths}
+
+\end_inset
+
+\SpecialChar ~
+
+\begin_inset Quotes sld
+\end_inset
+
+Search Paths
+\begin_inset Quotes srd
+\end_inset
+
+..
+\layout Standard
+
+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.
+\layout Section
+
+Storage Class Language Extensions
+\layout Subsection
+
+MCS51/DS390 Storage Class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+ Language Extensions
+\layout Standard
+
+In addition to the ANSI storage classes SDCC allows the following MCS51
+ specific storage classes:
+\layout Subsubsection
+
+data
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\end_inset
+
+ / near
+\begin_inset LatexCommand \index{near (storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+This is the
+\series bold
+default
+\series default
+ storage class for the Small Memory model (
+\emph on
+data
+\emph default
+ and
+\emph on
+near
+\emph default
+ can be used synonymously).
+ Variables declared with this storage class will be allocated in the directly
+ addressable portion of the internal RAM of a 8051, e.g.:
+\layout Verse
+
+
+\family typewriter
+data unsigned char test_data;
+\layout Standard
+
+Writing 0x01 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+75*00 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+_test_data,#0x01
+\layout Subsubsection
+
+xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ / far
+\begin_inset LatexCommand \index{far (storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+Variables declared with this storage class will be placed in the external
+ RAM.
+ This is the
+\series bold
+default
+\series default
+ storage class for the Large Memory model, e.g.:
+\layout Verse
+
+
+\family typewriter
+xdata unsigned char test_xdata;
+\layout Standard
+
+Writing 0x01 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+90s00r00\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+dptr,#_test_xdata
+\newline
+74\SpecialChar ~
+01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+a,#0x01
+\newline
+F0\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movx\SpecialChar ~
+@dptr,a
+\layout Subsubsection
+
+idata
+\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+Variables declared with this storage class will be allocated into the indirectly
+ addressable portion of the internal ram of a 8051, e.g.:
+\layout Verse
+
+
+\family typewriter
+idata unsigned char test_idata;
+\layout Standard
+
+Writing 0x01 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+78r00\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+r0,#_test_idata
+\newline
+76\SpecialChar ~
+01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+@r0,#0x01
+\layout Standard
+
+Please note, the first 128 byte of idata physically access the same RAM
+ as the data memory.
+ The original 8051 had 128 byte idata memory, nowadays most devices have
+ 256 byte idata memory.
+ The stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ is located in idata memory.
+\layout Subsubsection
+
+pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+Paged xdata access is currently not as straightforward as using the other
+ addressing modes of a 8051.
+ The following example writes 0x01 to the address pointed to.
+ Please note, pdata access physically accesses xdata memory.
+ The high byte of the address is determined by port P2
+\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
+
+\end_inset
+
+(or in case of some 8051 variants by a separate Special Function Register,
+ see section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
+
+\end_inset
+
+).
+\layout Verse
+
+
+\family typewriter
+pdata unsigned char *test_pdata_ptr;
+\newline
+
+\newline
+void main()
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+test_pdata_ptr = (pdata *)0xfe;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+*test_pdata_ptr = 1;
+\newline
+}
+\layout Standard
+
+Generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+75*01 FE\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ _test_pdata_ptr,#0xFE
+\newline
+78 FE\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ r0,#0xFE
+\newline
+74 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+ a,#0x01
+\newline
+F2\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movx @r0,a
+\layout Standard
+
+Be extremely carefull if you use pdata together with the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack
+\begin_inset LatexCommand \index{-\/-xstack}
+
+\end_inset
+
+ option.
+\layout Subsubsection
+
+code
+\begin_inset LatexCommand \index{code}
+
+\end_inset
+
+
+\layout Standard
+
+'Variables' declared with this storage class will be placed in the code
+ memory:
+\layout Verse
+
+
+\family typewriter
+code unsigned char test_code;
+\layout Standard
+
+Read access to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+90s00r6F\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov dptr,#_test_code
+\newline
+E4\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+clr a
+\newline
+93\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movc a,@a+dptr
+\layout Standard
+
+
+\family typewriter
+char
+\family default
+ indexed arrays of characters in code memory can be accessed efficiently:
+\layout Verse
+
+
+\family typewriter
+code char test_array[] = {'c','h','e','a','p'};
+\layout Standard
+
+Read access to this array using an 8-bit unsigned index generates the assembly
+ code:
+\layout Verse
+
+
+\family typewriter
+E5*00\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov a,_index
+\layout Verse
+
+
+\family typewriter
+90s00r41\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov dptr,#_test_array
+\layout Verse
+
+
+\family typewriter
+93\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movc a,@a+dptr
+\layout Subsubsection
+
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+
+\layout Standard
+
+This is a data-type and a storage class specifier.
+ When a variable is declared as a bit, it is allocated into the bit addressable
+ memory of 8051, e.g.:
+\layout Verse
+
+
+\family typewriter
+bit test_bit;
+\layout Standard
+
+Writing 1 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+D2*00\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+setb\SpecialChar ~
+_test_bit
+\layout Standard
+
+The bit addressable memory consists of 128 bits which are located from 0x20
+ to 0x2f in data memory.
+
+\layout Standard
+
+Apart from this 8051 specific storage class most architectures support ANSI-C
+ bitfields
+\begin_inset LatexCommand \index{bitfields}
+
+\end_inset
+
+
+\newline
+
+\layout Standard
+
+In accordance with ISO/IEC 9899 bits and bitfields without an explicit signed
+ modifier are implemented as unsigned.
+\layout Standard
+
+
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+Not really meant as examples, but nevertheless showing what bitfields are
+ about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c
+\end_inset
+
+.
+\layout Subsubsection
+
+sfr
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+ / sbit
+\begin_inset LatexCommand \index{sbit}
+
+\end_inset
+
+
+\layout Standard
+
+Like the bit keyword,
+\emph on
+sfr / sbit
+\emph default
+signifies both a data-type and storage class, they are used to describe
+ the
+\emph on
+s
+\emph default
+pecial
+\emph on
+f
+\emph default
+unction
+\emph on
+r
+\emph default
+egisters and
+\emph on
+s
+\emph default
+pecial
+\emph on
+bit
+\emph default
+ variables of a 8051, eg:
+\layout Verse
+
+
+\family typewriter
+sfr at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x80 P0;\SpecialChar ~
+ /* special function register P0 at location 0x80 */
+\newline
+sbit at 0xd7 CY; /* CY (Carry Flag
+\begin_inset LatexCommand \index{Flags}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Carry flag}
+
+\end_inset
+
+) */
+\layout Standard
+
+Special function registers which are located on an address dividable by
+ 8 are bit-addressable, an
+\emph on
+ sbit
+\emph default
+ addresses a specific bit within these sfr.
+\layout Subsubsection
+
+Pointers
+\begin_inset LatexCommand \index{Pointer}
+
+\end_inset
+
+ to MCS51/DS390 specific memory spaces
+\layout Standard
+
+SDCC allows (via language extensions) pointers to explicitly point to any
+ of the memory spaces
+\begin_inset LatexCommand \index{Memory model}
+
+\end_inset
+
+ of the 8051.
+ In addition to the explicit pointers, the compiler uses (by default) generic
+ pointers which can be used to point to any of the memory spaces.
+\newline
+
+\newline
+Pointer declaration examples:
+\layout Verse
+
+
+\family typewriter
+/* pointer physically in internal ram pointing to object in external ram
+ */
+\newline
+xdata unsigned char * data p;
+\newline
+
+\newline
+/* pointer physically in external ram pointing to object in internal ram
+ */
+\newline
+data unsigned char * xdata p;
+\newline
+
+\newline
+/* pointer physically in code rom pointing to data in xdata space */
+\newline
+xdata unsigned char * code p;
+\newline
+
+\newline
+/* pointer physically in code space pointing to data in code space */
+\newline
+code unsigned char * code p;
+\newline
+
+\newline
+/* the following is a generic pointer physically located in xdata space
+ */
+\newline
+char * xdata p;
+\layout Standard
+
+Well you get the idea.
+
+\newline
+
+\newline
+All unqualified pointers are treated as 3-byte (4-byte for the ds390)
+\emph on
+generic
+\emph default
+ pointers.
+
+\size small
+
+\newline
+
+\newline
+
+\size default
+The highest order byte of the
+\emph on
+generic
+\emph default
+ pointers contains the data space information.
+ Assembler support routines are called whenever data is stored or retrieved
+ using
+\emph on
+generic
+\emph default
+ pointers.
+ These are useful for developing reusable library
+\begin_inset LatexCommand \index{Libraries}
+
+\end_inset
+
+ routines.
+ Explicitly specifying the pointer type will generate the most efficient
+ code.
+\layout Subsubsection
+
+Notes on MCS51 memory
+\begin_inset LatexCommand \index{MCS51 memory}
+
+\end_inset
+
+ layout
+\layout Standard
+
+The 8051 family of microcontrollers have a minimum of 128 bytes of internal
+ RAM memory which is structured as follows:
+\newline
+
+\newline
+- Bytes 00-1F - 32 bytes to hold up to 4 banks of the registers R0 to R7,
+
+\newline
+- Bytes 20-2F - 16 bytes to hold 128 bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ variables and,
+\newline
+- Bytes 30-7F - 80 bytes for general purpose use.
+\newline
+
+\layout Standard
+
+Additionally some members of the MCS51 family may have up to 128 bytes of
+ additional, indirectly addressable, internal RAM memory (
+\emph on
+idata
+\emph default
+
+\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
+
+\end_inset
+
+).
+ Furthermore, some chips may have some built in external memory (
+\emph on
+xdata
+\emph default
+
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+) which should not be confused with the internal, directly addressable RAM
+ memory (
+\emph on
+data
+\emph default
+
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\end_inset
+
+).
+ Sometimes this built in
+\emph on
+xdata
+\emph default
+ memory has to be activated before using it (you can probably find this
+ information on the datasheet of the microcontroller your are using, see
+ also section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
+\end_inset
+
+\SpecialChar ~
+Startup-Code).
+\layout Standard
+
+Normally SDCC will only use the first bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+
+\end_inset
+
+ of registers (register bank 0), but it is possible to specify that other
+ banks of registers should be used in interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ routines.
+ By default, the compiler will place the stack after the last byte of allocated
+ memory for variables.
+ For example, if the first 2 banks of registers are used, and only four
+ bytes are used for
+\emph on
+data
+\emph default
+ variables, it will position the base of the internal stack at address 20
+ (0x14).
+ This implies that as the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ grows, it will use up the remaining register banks, and the 16 bytes used
+ by the 128 bit variables, and 80 bytes for general purpose use.
+ If any bit variables are used, the data variables will be placed after
+ the byte holding the last bit variable.
+ For example, if register banks 0 and 1 are used, and there are 9 bit variables
+ (two bytes used),
+\emph on
+data
+\emph default
+ variables will be placed starting at address 0x22.
+ You can also use -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc
+\begin_inset LatexCommand \index{-\/-data-loc<Value>}
+
+\end_inset
+
+ to specify the start address of the
+\emph on
+data
+\emph default
+ and -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-iram-size to specify the size of the total internal RAM (
+\emph on
+data
+\emph default
++
+\emph on
+idata
+\emph default
+).
+
+\layout Standard
+
+By default the 8051 linker will place the stack after the last byte of data
+ variables.
+ Option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc
+\begin_inset LatexCommand \index{-\/-stack-loc<Value>}
+
+\end_inset
+
+ allows you to specify the start of the stack, i.e.
+ you could start it after any data in the general purpose area.
+ If your microcontroller has additional indirectly addressable internal
+ RAM (
+\emph on
+idata
+\emph default
+) you can place the stack on it.
+ You may also need to use -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xdata-loc
+\begin_inset LatexCommand \index{-\/-xdata-loc<Value>}
+
+\end_inset
+
+ to set the start address of the external RAM (
+\emph on
+xdata
+\emph default
+) and -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xram-size
+\begin_inset LatexCommand \index{-\/-data-loc}
+
+\end_inset
+
+ to specify its size.
+ Same goes for the code memory, using -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-loc
+\begin_inset LatexCommand \index{-\/-data-loc}
+
+\end_inset
+
+ and -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-code-size
+\begin_inset LatexCommand \index{-\/-data-loc}
+
+\end_inset
+
+.
+ If in doubt, don't specify any options and see if the resulting memory
+ layout is appropriate, then you can adjust it.
+\layout Standard
+
+The linker generates two files with memory allocation information.
+ The first, with extension .map
+\begin_inset LatexCommand \index{<file>.map}
+
+\end_inset
+
+ shows all the variables and segments.
+ The second with extension .mem
+\begin_inset LatexCommand \index{<file>.mem}
+
+\end_inset
+
+ shows the final memory layout.
+ The linker will complain either if memory segments overlap, there is not
+ enough memory, or there is not enough space for stack.
+ If you get any linking warnings and/or errors related to stack or segments
+ allocation, take a look at either the .map or .mem files to find out what
+ the problem is.
+ The .mem file may even suggest a solution to the problem.
+\layout Subsection
+
+Z80/Z180 Storage Class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+ Language Extensions
+\layout Subsubsection
+
+sfr
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+ (in/out to 8-bit addresses)
+\layout Standard
+
+The Z80
+\begin_inset LatexCommand \index{Z80}
+
+\end_inset
+
+ family has separate address spaces for memory and
+\emph on
+i
+\emph default
+nput/
+\emph on
+o
+\emph default
+utput memory.
+ I/O memory
+\begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
+
+\end_inset
+
+ is accessed with special instructions, e.g.:
+\layout Verse
+
+
+\family typewriter
+sfr at 0x78 IoPort;\SpecialChar ~
+\SpecialChar ~
+/* define a var in I/O space at 78h called IoPort */
+
+\layout Standard
+
+Writing 0x01 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+3E 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ld a,#0x01
+\newline
+D3 78\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+out (_IoPort),a
+\layout Subsubsection
+
+banked sfr
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+ (in/out to 16-bit addresses)
+\layout Standard
+
+The keyword
+\emph on
+banked
+\emph default
+ is used to support 16 bit addresses in I/O memory e.g.:
+\layout Verse
+
+
+\family typewriter
+sfr banked at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x123 IoPort;
+\layout Standard
+
+Writing 0x01 to this variable generates the assembly code:
+\layout Verse
+
+
+\family typewriter
+01 23 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ld bc,#_IoPort
+\newline
+3E 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ld a,#0x01
+\newline
+ED 79\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+out (c),a
+\layout Subsubsection
+
+sfr
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+ (in0/out0 to 8 bit addresses on Z180
+\begin_inset LatexCommand \index{Z180}
+
+\end_inset
+
+/HD64180
+\begin_inset LatexCommand \index{HD64180}
+
+\end_inset
+
+)
+\layout Standard
+
+The compiler option -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-portmode=180 (80) and a compiler #pragma\SpecialChar ~
+portmode
+\begin_inset LatexCommand \index{\#pragma portmode}
+
+\end_inset
+
+=z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
+ns
+\family typewriter
+in0/out0
+\family default
+ instead of
+\family typewriter
+in/out
+\family default
+.
+ If you include the file z180.h this will be set automatically.
+\layout Subsection
+
+HC08 Storage Class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+ Language Extensions
+\layout Subsubsection
+
+data
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+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.
+\layout Subsubsection
+
+xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+
+\layout Standard
+
+The xdata storage class declares a variable that can reside anywhere in
+ memory.
+ This is the default if no storage class is specified.
+
+\layout Section
+
+Absolute Addressing
+\begin_inset LatexCommand \index{Absolute addressing}
+
+\end_inset
+
+
+\layout Standard
+
+Data items can be assigned an absolute address with the
+\emph on
+at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ <address>
+\emph default
+ keyword, in addition to a storage class, e.g.:
+\layout Verse
+
+
+\family typewriter
+xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x7ffe unsigned int chksum;
+\layout Standard
+
+In the above example the variable chksum will located at 0x7ffe and 0x7fff
+ of the external ram.
+ The compiler does
+\emph on
+not
+\emph default
+ reserve any space for variables declared in this way (they are implemented
+ with an equate in the assembler).
+ Thus it is left to the programmer to make sure there are no overlaps with
+ other variables that are declared without the absolute address.
+ The assembler listing file (.lst
+\begin_inset LatexCommand \index{<file>.lst}
+
+\end_inset
+
+) and the linker output files (.rst
+\begin_inset LatexCommand \index{<file>.rst}
+
+\end_inset
+
+) and (.map
+\begin_inset LatexCommand \index{<file>.map}
+
+\end_inset
+
+) are good places to look for such overlaps.
+ Variables with an absolute address are
+\emph on
+not
+\emph default
+ initialized
+\begin_inset LatexCommand \index{Variable initialization}
+
+\end_inset
+
+.
+\layout Standard
+
+In case of memory mapped I/O devices the keyword
+\emph on
+volatile
+\emph default
+ should be used to tell the compiler that accesses might not be optimized
+ away:
+\layout Verse
+
+
+\family typewriter
+volatile
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+ xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x8000 unsigned char PORTA_8255;
+\layout Standard
+
+For some architectures (mcs51) array accesses are more efficient if an (xdata/fa
+r) array
+\family typewriter
+\size footnotesize
+
+\begin_inset LatexCommand \index{Aligned array}
+
+\end_inset
+
+
+\family default
+\size default
+ starts at a block (256 byte) boundary
+\begin_inset LatexCommand \index{block boundary}
+
+\end_inset
+
+ (section
+\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+
+\end_inset
+
+ has an example).
+\newline
+Absolute addresses can be specified for variables in all storage classes,
+ e.g.:
+\layout Verse
+
+
+\family typewriter
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x02 bvar;
+\layout Standard
+
+The above example will allocate the variable at offset 0x02 in the bit-addressab
+le space.
+ There is no real advantage to assigning absolute addresses to variables
+ in this manner, unless you want strict control over all the variables allocated.
+ One possible use would be to write hardware portable code.
+ For example, if you have a routine that uses one or more of the microcontroller
+ I/O pins, and such pins are different for two different hardwares, you
+ can declare the I/O pins in your routine using:
+\layout Verse
+
+
+\family typewriter
+extern volatile bit SDI;
+\newline
+extern volatile bit SCLK;
+\newline
+extern volatile bit CPOL;
+\newline
+
+\newline
+void DS1306_put(unsigned char value)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+unsigned char mask=0x80;
+\newline
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+while(mask)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDI=(value & mask)?1:0;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SCLK=!CPOL;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SCLK=CPOL;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mask/=2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+}
+\newline
+}
+\layout Standard
+
+Then, someplace in the code for the first hardware you would use
+\layout Verse
+
+
+\family typewriter
+bit at 0x80 SDI;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 0 */
+\newline
+bit at 0x81 SCLK;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 1 */
+\newline
+bit CPOL;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* This is a variable, let the linker allocate this one */
+\layout Standard
+
+Similarly, for the second hardware you would use
+\layout Verse
+
+
+\family typewriter
+bit at 0x83 SDI;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 3 */
+\newline
+bit at 0x91 SCLK;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 1, bit 1 */
+\newline
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ CPOL;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* This is a variable, let the linker allocate this one */
+\layout Standard
+
+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
+ specified in the whole project.
+\layout Section
+
+Parameters
+\begin_inset LatexCommand \index{Parameters}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{function parameter}
+
+\end_inset
+
+ & Local Variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+
+\layout Standard
+
+Automatic (local) variables and parameters to functions can either be placed
+ on the stack or in data-space.
+ The default action of the compiler is to place these variables in the internal
+ RAM (for small model) or external RAM (for large model).
+ This in fact makes them similar to
+\emph on
+static
+\begin_inset LatexCommand \index{static}
+
+\end_inset
+
+
+\emph default
+ so by default functions are non-reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+.
+
+\newline
+
+\newline
+They can be placed on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ either by using the
+\emph on
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\emph default
+ option or by using the
+\emph on
+reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+
+\emph default
+ keyword in the function declaration, e.g.:
+\layout Verse
+
+
+\family typewriter
+unsigned char foo(char i) reentrant
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+Since stack space on 8051 is limited, the
+\emph on
+reentrant
+\emph default
+keyword or the
+\emph on
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\emph default
+ option should be used sparingly.
+ Note that the reentrant keyword just means that the parameters & local
+ variables will be allocated to the stack, it
+\emph on
+does not
+\emph default
+ mean that the function is register bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+
+\end_inset
+
+ independent.
+\newline
+
+\newline
+Local variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ can be assigned storage classes and absolute
+\begin_inset LatexCommand \index{Absolute addressing}
+
+\end_inset
+
+ addresses, e.g.:
+\layout Verse
+
+
+\family typewriter
+unsigned char foo()
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+xdata unsigned char i;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+bit bvar;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+data at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x31 unsigned char j;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+In the above example the variable
+\emph on
+i
+\emph default
+ will be allocated in the external ram,
+\emph on
+bvar
+\emph default
+ in bit addressable space and
+\emph on
+ j
+\emph default
+ in internal ram.
+ When compiled with
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\emph default
+ or when a function is declared as
+\emph on
+reentrant
+\emph default
+ this should only be done for static variables.
+\layout Standard
+
+Parameters
+\begin_inset LatexCommand \index{function parameter}
+
+\end_inset
+
+ however are not allowed any storage class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+, (storage classes for parameters will be ignored), their allocation is
+ governed by the memory model in use, and the reentrancy options.
+\layout Section
+
+Overlaying
+\begin_inset LatexCommand \label{sub:Overlaying}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Overlaying}
+
+\end_inset
+
+
+\layout Standard
+
+For non-reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+ functions SDCC will try to reduce internal ram space usage by overlaying
+ parameters and local variables of a function (if possible).
+ Parameters and local variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ of a function will be allocated to an overlayable segment if the function
+ has
+\emph on
+no other function calls and the function is non-reentrant and the memory
+ model
+\begin_inset LatexCommand \index{Memory model}
+
+\end_inset
+
+ is small.
+
+\emph default
+ If an explicit storage class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+ is specified for a local variable, it will NOT be overlayed.
+\layout Standard
+
+Note that the compiler (not the linkage editor) makes the decision for overlayin
+g the data items.
+ Functions that are called from an interrupt service routine should be preceded
+ by a #pragma\SpecialChar ~
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+ if they are not reentrant.
+\layout Standard
+
+Also note that the compiler does not do any processing of inline assembler
+ code, so the compiler might incorrectly assign local variables and parameters
+ of a function into the overlay segment if the inline assembler code calls
+ other c-functions that might use the overlay.
+ In that case the #pragma\SpecialChar ~
+nooverlay should be used.
+\layout Standard
+
+Parameters and local variables of functions that contain 16 or 32 bit multiplica
+tion
+\begin_inset LatexCommand \index{Multiplication}
+
+\end_inset
+
+ or division
+\begin_inset LatexCommand \index{Division}
+
+\end_inset
+
+ will NOT be overlayed since these are implemented using external functions,
+ e.g.:
+\layout Verse
+
+
+\family typewriter
+#pragma save
+\newline
+#pragma nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+
+\newline
+void set_error(unsigned char errcd)
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+P3 = errcd;
+\newline
+}
+\newline
+#pragma restore
+\newline
+
+\newline
+void some_isr () interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ 2
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+set_error(10);
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+In the above example the parameter
+\emph on
+errcd
+\emph default
+ for the function
+\emph on
+set_error
+\emph default
+ would be assigned to the overlayable segment if the #pragma\SpecialChar ~
+nooverlay was
+ not present, this could cause unpredictable runtime behavior when called
+ from an interrupt service routine.
+ The #pragma\SpecialChar ~
+nooverlay ensures that the parameters and local variables for
+ the function are NOT overlayed.
+\layout Section
+
+Interrupt Service Routines
+\begin_inset LatexCommand \label{sub:Interrupt-Service-Routines}
+
+\end_inset
+
+
+\layout Subsection
+
+General Information
+\layout Standard
+
+SDCC allows
+\emph on
+i
+\emph default
+nterrupt
+\emph on
+s
+\emph default
+ervice
+\emph on
+r
+\emph default
+outines to be coded in C, with some extended keywords.
+\layout Verse
+
+
+\family typewriter
+void timer_isr (void) interrupt 1 using 1
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+The optional number following the
+\emph on
+interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
+\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.
+ 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
+\emph on
+main
+\emph default
+.
+ The
+\emph on
+using
+\emph default
+ keyword can be used to tell the compiler to use the specified register
+ bank (8051 specific) when generating code for this function.
+
+\newline
+
+\layout Standard
+
+Interrupt service routines open the door for some very interesting bugs:
+
+\layout Standard
+
+If the interrupt service routines changes variables which are accessed by
+ other functions these variables should be declared
+\emph on
+volatile
+\emph default
+
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+.
+
+\layout Standard
+
+If the access to these variables is not
+\emph on
+atomic
+\begin_inset LatexCommand \index{atomic access}
+
+\end_inset
+
+
+\emph default
+ (i.e.
+ the processor needs more than one instruction for the access and could
+ be interrupted while accessing the variable) the interrupt must 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.
+ 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
+\begin_inset Quotes srd
+\end_inset
+
+
+\family typewriter
+flags\SpecialChar ~
+|=\SpecialChar ~
+0x80;
+\family default
+
+\begin_inset Quotes sld
+\end_inset
+
+ is not atomic if
+\family typewriter
+flags
+\family default
+ resides in xdata.
+ Setting
+\begin_inset Quotes srd
+\end_inset
+
+
+\family typewriter
+flags\SpecialChar ~
+|=\SpecialChar ~
+0x40;
+\family default
+
+\begin_inset Quotes sld
+\end_inset
+
+ from within an interrupt routine might get lost if the interrupt occurs
+ at the wrong time.
+
+\begin_inset Quotes sld
+\end_inset
+
+
+\family typewriter
+counter\SpecialChar ~
++=\SpecialChar ~
+8;
+\family default
+
+\begin_inset Quotes srd
+\end_inset
+
+ is not atomic on the 8051 even if
+\family typewriter
+counter
+\family default
+ is located in data memory.
+ Bugs like these are hard to reproduce and can cause a lot of trouble.
+
+\layout Standard
+
+A special note here, int (16 bit) and long (32 bit) integer division
+\begin_inset LatexCommand \index{Division}
+
+\end_inset
+
+, multiplication
+\begin_inset LatexCommand \index{Multiplication}
+
+\end_inset
+
+ & modulus
+\begin_inset LatexCommand \index{Modulus}
+
+\end_inset
+
+ and floating-point
+\begin_inset LatexCommand \index{Floating point support}
+
+\end_inset
+
+ operations are implemented using external support routines developed in
+ ANSI-C.
+ 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
+\emph on
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\emph default
+ option and the source file will need to be compiled using the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-int-long-reent
+\emph default
+
+\begin_inset LatexCommand \index{-\/-int-long-reent}
+
+\end_inset
+
+ compiler option.
+\layout Standard
+
+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
+ it should be preceded by a #pragma\SpecialChar ~
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+ if it is not reentrant.
+ Furthermore nonreentrant functions should not be called from the main program
+ while the interrupt service routine might be active.
+
+\newline
+
+\newline
+Also see section
+\begin_inset LatexCommand \ref{sub:Overlaying}
+
+\end_inset
+
+\SpecialChar ~
+about Overlaying and section
+\begin_inset LatexCommand \ref{sub:Functions-using-private-banks}
+
+\end_inset
+
+\SpecialChar ~
+about Functions using private register banks.
+\layout Subsection
+
+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.
+\newline
+
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="7" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0in">
+<column alignment="center" valignment="top" leftline="true" width="0in">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt #
+\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
+
+\layout Standard
+
+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
+
+External 0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x0003
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<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" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Timer 0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000B
+\end_inset
+</cell>
+</row>
+<row topline="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
+
+External 1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x0013
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+3
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Timer 1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x001B
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+4
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Serial
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x0023
+\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
+
+5
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Timer 2 (8052)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x002B
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\layout Standard
+
+If the interrupt service routine is defined without
+\emph on
+using
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\emph default
+ a register bank or with register bank 0 (
+\emph on
+using
+\emph default
+ 0), the compiler will save the registers used by itself on the stack upon
+ entry and restore them at exit, however if such an interrupt service routine
+ calls another function then the entire register bank will be saved on the
+ stack.
+ This scheme may be advantageous for small interrupt service routines which
+ have low register usage.
+\layout Standard
+
+If the interrupt service routine is defined to be using a specific register
+ bank then only
+\emph on
+a, b, dptr
+\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.
+ This scheme is recommended for larger interrupt service routines.
+\layout Subsection
+
+HC08 Interrupt Service Routines
+\layout Standard
+
+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.
+ 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
+ this way; instead see section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
+\end_inset
+
+ for details on customizing startup.
+\layout Section
+
+Enabling and Disabling Interrupts
+\layout Subsection
+
+Critical Functions and Critical Statements
+\layout Standard
+
+A special keyword may be associated with a block or a function declaring
+ it as
+\emph on
+critical
+\emph default
+.
+ SDCC will generate code to disable all interrupts
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ upon entry to a critical function and restore the interrupt enable to the
+ previous state before returning.
+ Nesting critical functions will need one additional byte on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ for each call.
+\layout Verse
+
+
+\family typewriter
+int foo () critical
+\begin_inset LatexCommand \index{critical}
+
+\end_inset
+
+
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+The critical attribute maybe used with other attributes like
+\emph on
+reentrant.
+\emph default
+
+\newline
+The keyword
+\emph on
+critical
+\emph default
+ may also be used to disable interrupts more locally:
+\layout Verse
+
+
+\family typewriter
+critical{ i++; }
+\layout Standard
+
+More than one statement could have been included in the block.
+\layout Subsection
+
+Enabling and Disabling Interrupts directly
+\layout Standard
+
+Interrupts
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ can also be disabled and enabled directly (8051):
+\layout Verse
+
+
+\family typewriter
+EA = 0;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+or:\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+EA_SAVE = EA;
+\layout Verse
+
+
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+EA = 0;
+\layout Verse
+
+
+\family typewriter
+EA = 1;\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 Verse
+
+
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+EA = EA_SAVE;
+\layout Standard
+
+On other architectures which have seperate opcodes for enabling and disabling
+ interrupts you might want to make use of defines with inline assembly
+\begin_inset LatexCommand \index{Assembler routines}
+
+\end_inset
+
+ (HC08):
+\layout Verse
+
+
+\family typewriter
+#define CLI _asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+\SpecialChar ~
+\SpecialChar ~
+cli\SpecialChar ~
+\SpecialChar ~
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+;
+\layout Verse
+
+
+\family typewriter
+#define SEI _asm\SpecialChar ~
+\SpecialChar ~
+sei\SpecialChar ~
+\SpecialChar ~
+_endasm;
+\layout Verse
+
+
+\family typewriter
+...
+\layout Standard
+
+Note: it is sometimes sufficient to disable only a specific interrupt source
+ like f.e.
+ a timer or serial interrupt by manipulating an
+\emph on
+interrupt mask
+\begin_inset LatexCommand \index{interrupt mask}
+
+\end_inset
+
+
+\emph default
+ register.
+
+\layout Standard
+
+Usually the time during which interrupts are disabled should be kept as
+ short as possible.
+ This minimizes both
+\emph on
+interrupt latency
+\emph default
+
+\begin_inset LatexCommand \index{interrupt latency}
+
+\end_inset
+
+ (the time between the occurrence of the interrupt and the execution of
+ the first code in the interrupt routine) and
+\emph on
+interrupt jitter
+\emph default
+
+\begin_inset LatexCommand \index{interrupt jitter}
+
+\end_inset
+
+ (the difference between the shortest and the longest interrupt latency).
+ These really are something different, f.e.
+ a serial interrupt has to be served before its buffer overruns so it cares
+ for the maximum interrupt latency, whereas it does not care about jitter.
+ On a loudspeaker driven via a digital to analog converter which is fed
+ by an interrupt a latency of a few milliseconds might be tolerable, whereas
+ a much smaller jitter will be very audible.
+\layout Standard
+
+You can reenable interrupts within an interrupt routine and on some architecture
+s you can make use of two (or more) levels of
+\emph on
+interrupt priorities
+\emph default
+
+\begin_inset LatexCommand \index{interrupt priority}
+
+\end_inset
+
+.
+ On some architectures which don't support interrupt priorities these can
+ be implemented by manipulating the interrupt mask and reenabling interrupts
+ within the interrupt routine.
+ Don't add complexity unless you have to.
+
+\layout Section
+
+Functions using private register banks
+\begin_inset LatexCommand \label{sub:Functions-using-private-banks}
+
+\end_inset
+
+ (mcs51/ds390)
+\layout Standard
+
+Some architectures have support for quickly changing register sets.
+ SDCC supports this feature with the
+\emph on
+using
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\emph default
+ attribute (which tells the compiler to use a register bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+
+\end_inset
+
+ other than the default bank zero).
+ It should only be applied to
+\emph on
+interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
+\emph default
+ functions (see footnote below).
+ This will in most circumstances make the generated ISR code more efficient
+ since it will not have to save registers on the stack.
+\layout Standard
+
+The
+\emph on
+using
+\emph default
+ attribute will have no effect on the generated code for a
+\emph on
+non-interrupt
+\emph default
+ function (but may occasionally be useful anyway
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+possible exception: if a function is called ONLY from 'interrupt' functions
+ using a particular bank, it can be declared with the same 'using' attribute
+ as the calling 'interrupt' functions.
+ For instance, if you have several ISRs using bank one, and all of them
+ call memcpy(), it might make sense to create a specialized version of memcpy()
+ 'using 1', since this would prevent the ISR from having to save bank zero
+ to the stack on entry and switch to bank zero before calling the function
+\end_inset
+
+).
+\newline
+
+\emph on
+(pending: I don't think this has been done yet)
+\layout Standard
+
+An
+\emph on
+interrupt
+\emph default
+ function using a non-zero bank will assume that it can trash that register
+ bank, and will not save it.
+ Since high-priority interrupts
+\begin_inset LatexCommand \index{interrupt priority}
+
+\end_inset
+
+ can interrupt low-priority ones on the 8051 and friends, this means that
+ if a high-priority ISR
+\emph on
+using
+\emph default
+ a particular bank occurs while processing a low-priority ISR
+\emph on
+using
+\emph default
+ the same bank, terrible and bad things can happen.
+ To prevent this, no single register bank should be
+\emph on
+used
+\emph default
+ by both a high priority and a low priority ISR.
+ This is probably most easily done by having all high priority ISRs use
+ one bank and all low priority ISRs use another.
+ If you have an ISR which can change priority at runtime, you're on your
+ own: I suggest using the default bank zero and taking the small performance
+ hit.
+\layout Standard
+
+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
+ called functions use bank zero.
+ It is very inefficient to call a function using a different, non-zero bank
+ from an ISR.
+
+\layout Section
+
+Startup Code
+\begin_inset LatexCommand \label{sub:Startup-Code}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Startup code}
+
+\end_inset
+
+
+\layout Subsection
+
+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()}
+
+\end_inset
+
+
+\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}
+
+\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.
+ On some mcs51 variants xdata has to be explicitly enabled before it can
+ be accessed, this is the place to do it.
+ 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
+
+\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
+
+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
+-
+\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:
+\layout Verse
+
+
+\family typewriter
+\size footnotesize
+unsigned char far
+\begin_inset LatexCommand \index{far (storage class)}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x7f00 buf[0x100];
+\begin_inset LatexCommand \index{Aligned array}
+
+\end_inset
+
+
+\newline
+unsigned char head,tail;
+\newline
+
+\newline
+void to_buffer( unsigned char c )
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+if( head != tail-1 )
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+buf[ head++ ] = c;
+\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.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+The function is not yet OK! (registers aren't saved) */
+\newline
+void to_buffer_asm( unsigned char c )
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+r2,dpl
+\newline
+;buffer.c if( head != tail-1 )
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+a,_tail
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+dec\SpecialChar ~
+\SpecialChar ~
+a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+r3,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+a,_head
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+cjne a,ar3,00106$
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ret
+\newline
+00106$:
+\newline
+;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
+\begin_inset LatexCommand \index{Aligned array}
+
+\end_inset
+
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+r3,_head
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+inc\SpecialChar ~
+\SpecialChar ~
+_head
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+dpl,r3
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+dph,#(_buf >> 8)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov\SpecialChar ~
+\SpecialChar ~
+a,r2
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+movx @dptr,a
+\newline
+00103$:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ret
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+_endasm;
+\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];
+\newline
+unsigned char head,tail;
+\newline
+#define USE_ASSEMBLY (1)
+\newline
+
+\newline
+#if !USE_ASSEMBLY
+\newline
+
+\newline
+void to_buffer( unsigned char c )
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+if( head != tail-1 )
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+buf[ head++ ] = c;
+\newline
+}
+\newline
+
+\newline
+#else
+\newline
+
+\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}
+
+\end_inset
+
+
+\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 != 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;
+\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
+\end_inset
+
+.
+ The compiler does not do any validation of the code within the
+\family typewriter
+_asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+ ...
+ _endasm;
+\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
+
+.
+
+\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
+
+ 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}
+
+\end_inset
+
+
+\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}
+
+\end_inset
+
+;
+\newline
+}
+\layout Standard
+
+For an 8051 target, the generated simpleInterrupt looks like:
+\layout Verse
+
+
+\family typewriter
+_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 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}
+
+\end_inset
+
+ allows a more fine grained control over pushing & popping
+\begin_inset LatexCommand \index{push/pop}
+
+\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
+
+Use of Labels within Inline Assembler
+\layout Standard
+
+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
+\emph on
+per function
+\emph default
+\noun on
+)
+\noun default
+.
+
+\layout Verse
+
+
+\family typewriter
+_asm
+\begin_inset LatexCommand \index{\_asm}
+
+\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}
+
+\end_inset
+
+ ;
+\layout Standard
+
+Inline assembler code cannot reference any C-Labels, however it can reference
+ labels
+\begin_inset LatexCommand \index{Labels}
+
+\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 ;
+\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}
+
+\end_inset
+
+
+\layout Subsection
+
+Global Registers used for Parameter Passing
+\begin_inset LatexCommand \index{Parameter passing}
+
+\end_inset
+
+
+\layout Standard
+
+The compiler always uses the global registers
+\emph on
+DPL, DPH
+\begin_inset LatexCommand \index{DPTR, DPH, DPL}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{DPTR}
+
+\end_inset
+
+, 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)}
+
+\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 Standard
+
+\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}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler routines (non-reentrant)}
+
+\end_inset
+
+ 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
+
+The corresponding assembler function is:
+\layout Verse
+
+
+\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
+
+,#0x00
+\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
+
+ 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
+
+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
+
+\newline
+Assemble the assembler routine with the following command:
+\newline
+
+\newline
+
+\family sans
+\series bold
+asx8051 -losg asmfunc.asm
+\newline
+
+\newline
+
+\family default
+\series default
+Then compile and link the assembler routine to the C source file with the
+ following command:
+\newline
+
+\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}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler routines (reentrant)}
+
+\end_inset
+
+ 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 typewriter
+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
+
+The corresponding assembler routine is:
+\layout Verse
+
+
+\family typewriter
+.globl _asm_func
+\newline
+_asm_func:
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+push _bp
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov _bp,sp
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov r2,dpl
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov a,_bp
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add a,#0xfd
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov r0,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add a,#0xfc ;?
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov r1,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+mov a,@r0
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+add a,r2 ;?
+\newline
+\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
+
+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="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
+
+
+\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
+
+_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
+
+_modsint.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 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
+
+_moduint.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 modulus
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+_mullong.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+ 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
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\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
+
+_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
+
+unsigned 32 bit modulus
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\layout Standard
+
+Since they are compiled as
+\emph on
+non-reentrant
+\emph default
+
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+, interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\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}
+
+\end_inset
+
+
+\emph default
+ option, after which the source program will have to be compiled with
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-int-long-reent
+\begin_inset LatexCommand \index{-\/-int-long-reent}
+
+\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}
+
+\end_inset
+
+
+\layout Standard
+
+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 Standard
+\align center
+
+\size footnotesize
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="17" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
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+\begin_inset Text
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
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+\layout Standard
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+\end_inset
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+<row topline="true">
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+</row>
+<row topline="true">
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+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+
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+</row>
+<row topline="true">
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\family default
+\series default
+\shape default
+\size default
+\emph default
+\bar default
+\noun default
+\color default
+c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
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+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+
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+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+<row topline="true">
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+<row topline="true">
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+
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+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
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+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
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+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
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+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
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+\series medium
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+_ulong2fs.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
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+\series medium
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+\bar no
+\noun off
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+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
+
+\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
+
+
+\family roman
+\series medium
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+convert long to floating point number
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\layout Standard
+
+These support routines are developed in ANSI-C so there is room for space
+ and speed improvement.
+ Note if all these routines are used simultaneously the data space might
+ overflow.
+ For serious floating point usage it is recommended that the large model
+ be used.
+ 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
+
+
+\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 Standard
+
+
+\begin_inset LatexCommand \index{<stdio.h>}
+
+\end_inset
+
+As usual on embedded systems you have to provide your own
+\family typewriter
+getchar()
+\begin_inset LatexCommand \index{getchar()}
+
+\end_inset
+
+
+\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.
+ You'll find examples for serial routines f.e.
+ in sdcc/device/lib.
+\layout Standard
+
+If you're short on memory you might want to use
+\family typewriter
+printf_small()
+\family default
+
+\emph on
+instead
+\emph default
+ of
+\family typewriter
+ printf()
+\begin_inset LatexCommand \index{printf()}
+
+\end_inset
+
+.
+
+\family default
+ For the mcs51 there is an assembly version
+\family typewriter
+printf_fast()
+\family default
+ which should fit the requirements of many embedded systems (by unsetting
+ #defines it can be customized to
+\emph on
+not
+\emph default
+ support long variables and field widths).
+\layout Subsection
+
+Math functions (sin, pow, sqrt etc.)
+\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.
+\layout Standard
+
+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}
+
+\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
+
+Memory Models
+\layout Subsection
+
+MCS51 Memory Models
+\begin_inset LatexCommand \index{Memory model}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{MCS51 memory model}
+
+\end_inset
+
+
+\layout Subsubsection
+
+Small and Large
+\layout Standard
+
+SDCC allows two memory models for MCS51 code,
+\shape slanted
+small
+\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 both small
+ and large.
+ The compiled library modules are contained in separate directories as small
+ and large so that you can link to either set.
+
+\layout Standard
+
+When the 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}
+
+\end_inset
+
+ 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}
+
+\end_inset
+
+ 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}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{External stack (mcs51)}
+
+\end_inset
+
+
+\layout Standard
+
+
+\series bold
+Attention
+\series default
+: this option wasn't maintained for a long time and is quite buggy.
+ Small programs might work.
+ You've been warned!
+\layout Standard
+
+The external stack (-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack option
+\begin_inset LatexCommand \index{-\/-xstack}
+
+\end_inset
+
+) is located in pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ memory (usually at the start of the external ram segment) and is 256 bytes
+ in size.
+ When -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack option is used to compile the program, the parameters and local
+ variables
+\begin_inset LatexCommand \index{local variables}
+
+\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
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-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).
+\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)}
+
+\end_inset
+
+ (see also section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
+
+\end_inset
+
+), 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}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{DS390 memory model}
+
+\end_inset
+
+
+\layout Standard
+
+The only model supported is Flat 24
+\begin_inset LatexCommand \index{Flat 24 (DS390 memory model)}
+
+\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
+\emph on
+tinibios
+\emph default
+
+\begin_inset LatexCommand \index{Tinibios (DS390)}
+
+\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
+
+\newline
+Like the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-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
+
+\layout Standard
+
+\backslash
+/
+\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}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC supports the following #pragma directives:
+\layout Itemize
+
+save
+\begin_inset LatexCommand \index{\#pragma save}
+
+\end_inset
+
+ - this will save all current options to the save/restore stack.
+ See restore.
+\layout Itemize
+
+restore
+\begin_inset LatexCommand \index{\#pragma restore}
+
+\end_inset
+
+ - 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 save.
+\layout Itemize
+
+nogcse
+\begin_inset LatexCommand \index{\#pragma nogcse}
+
+\end_inset
+
+ - will stop global common subexpression elimination.
+\layout Itemize
+
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
+
+\end_inset
+
+ - will stop loop induction optimizations.
+\layout Itemize
+
+nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
+
+\end_inset
+
+ - 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}
+
+\end_inset
+
+.
+\layout Itemize
+
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+ - the compiler will not overlay the parameters and local variables of a
+ function.
+\layout Itemize
+
+less_pedantic
+\begin_inset LatexCommand \index{\#pragma less\_pedantic}
+
+\end_inset
+
+ - the compiler will not warn you anymore for obvious mistakes, you'r on
+ your own now ;-(
+\layout Itemize
+
+noloopreverse
+\begin_inset LatexCommand \index{\#pragma noloopreverse}
+
+\end_inset
+
+ - Will not do loop reversal optimization
+\layout Itemize
+
+exclude
+\begin_inset LatexCommand \index{\#pragma exclude}
+
+\end_inset
+
+ none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables generation of
+ pair of push/pop
+\begin_inset LatexCommand \index{push/pop}
+
+\end_inset
+
+ instruction in ISR function (using interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ keyword).
+ 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 Itemize
+
+noiv
+\begin_inset LatexCommand \index{\#pragma noiv}
+
+\end_inset
+
+ - Do not generate interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ 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}
+
+\end_inset
+
+\SpecialChar ~
+about interrupts.
+\layout Itemize
+
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{function prologue}
+
+\end_inset
+
+ 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
+
+\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}
+
+\end_inset
+
+ is appended to the list of functions specified in the command line.
+\layout Standard
+
+SDCPP supports the following #pragma directives:
+\layout Itemize
+
+preproc_asm
+\begin_inset LatexCommand \index{\#pragma preproc\_asm}
+
+\end_inset
+
+ (+ | -) - switch _asm _endasm block preprocessing on / off.
+ Default is on.
+\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
+
+
+\family typewriter
+#pragma save
+\begin_inset LatexCommand \index{\#pragma save}
+
+\end_inset
+
+ \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* save the current settings */
+\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 */
+\newline
+\SpecialChar ~
+ \SpecialChar ~
+ ...
+
+\newline
+}
+\newline
+#pragma restore
+\begin_inset LatexCommand \index{\#pragma restore}
+
+\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
+
+Defines Created by the Compiler
+\layout Standard
+
+The compiler creates the following #defines
+\begin_inset LatexCommand \index{\#defines}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Defines created by the compiler}
+
+\end_inset
+
+:
+\newline
+
+\layout Standard
+
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="10" 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
+
+
+\series bold
+#define
+\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
+
+SDCC
+\begin_inset LatexCommand \index{SDCC}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+this Symbol is always defined
+\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}
+
+\end_inset
+
+ or SDCC_ds390
+\begin_inset LatexCommand \index{SDCC\_ds390}
+
+\end_inset
+
+ or SDCC_z80
+\begin_inset LatexCommand \index{SDCC\_z80}
+
+\end_inset
+
+, etc
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+\layout Standard
+
+__mcs51
+\begin_inset LatexCommand \index{\_\_mcs51}
+
+\end_inset
+
+, __ds390
+\begin_inset LatexCommand \index{\_\_ds390}
+
+\end_inset
+
+, __hc08
+\begin_inset LatexCommand \index{\_\_hc08}
+
+\end_inset
+
+, __z80
+\begin_inset LatexCommand \index{\_\_z80}
+
+\end_inset
+
+, etc
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+depending on the model used (e.g.
+ -mz80)
+\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
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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">
+<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}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-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
+
+\layout Standard
+
+SDCC_MODEL_LARGE
+\begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-large
+\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
+
+\layout Standard
+
+SDCC_USE_XSTACK
+\begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+SDCC_STACK_TENBIT
+\begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+SDCC_MODEL_FLAT24
+\begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+when
+\emph on
+-mds390
+\emph default
+ is used
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Chapter
+
+Notes on supported Processors
+\layout Section
+
+MCS51 variants
+\begin_inset LatexCommand \label{sub:MCS51-variants}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{MCS51 variants}
+
+\end_inset
+
+
+\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
+
+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)}
+
+\end_inset
+
+ as dedicated I/O port is becoming more popular.
+ Switching the high byte for pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ access which was formerly done by port P2 is then achieved by a Special
+ Function Register
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+.
+ 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.
+ As pdata addressing is used in the startup code for the initialization
+ of xdata variables a separate startup code should be used as described
+ in section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
+\end_inset
+
+.
+\layout Subsection
+
+Other Features available by SFR
+\layout Standard
+
+Some MCS51 variants offer features like Double DPTR
+\begin_inset LatexCommand \index{DPTR}
+
+\end_inset
+
+, 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
+
+The Z80 and gbz80 port
+\layout Standard
+
+SDCC can target both the Zilog
+\begin_inset LatexCommand \index{Z80}
+
+\end_inset
+
+ and the Nintendo Gameboy's Z80-like gbz80
+\begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
+
+\end_inset
+
+.
+ The Z80 port is passed through the same
+\emph on
+regressions tests
+\begin_inset LatexCommand \index{Regression test}
+
+\end_inset
+
+
+\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}
+
+\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
+
+ 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
+
+ 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 Section
+
+The PIC14 port
+\layout Standard
+
+The 14bit PIC
+\begin_inset LatexCommand \index{PIC14}
+
+\end_inset
+
+ port still requires a major effort from the development community.
+ However it can work for very simple code.
+\layout Subsection
+
+C code and 14bit PIC code page
+\begin_inset LatexCommand \index{code page (pic14)}
+
+\end_inset
+
+ and RAM banks
+\begin_inset LatexCommand \index{RAM bank (pic14)}
+
+\end_inset
+
+
+\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
+
+\newline
+To get the best follow these guide lines:
+\layout Enumerate
+
+make local functions static, as non static functions require code page selection
+ overhead.
+\layout Enumerate
+
+Make local variables static as extern variables require RAM bank 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 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
+
+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
+
+Interrupt code
+\layout Standard
+
+For the interrupt function, use the keyword 'interrupt'
+\begin_inset LatexCommand \index{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
+
+
+\family typewriter
+void Intr(void) interrupt 0
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+T0IF = 0; /* Clear timer interrupt */
+\newline
+}
+\layout Standard
+
+Linking and assembling
+\newline
+For assembling you can use either GPUTILS'
+\begin_inset LatexCommand \index{gputils (pic tools)}
+
+\end_inset
+
+ gpasm.exe or MPLAB's mpasmwin.exe.
+ 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
+
+\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)
+\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)
+\layout Section
+
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port
+\layout Standard
+
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port is the portion of SDCC that is responsible to produce code for the
+ Microchip
+\begin_inset LatexCommand \index{Microchip}
+
+\end_inset
+
+(TM) microcontrollers with 16 bit core.
+ Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
+\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 Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto Auto variables that are function parameters, will be saved on
+ stack by default.
+
+\emph on
+There is no need to specify this in the command line.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-float-reent All floating point functions are reentrant by default.
+
+\emph on
+There is no need to specifiy this in the command line.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\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
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\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
+
+-
+\begin_inset ERT
+status Collapsed
+
+\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
+\layout Standard
+
+The port specific options appear after the global options in the sdcc --help
+ output.
+\layout Subsubsection
+
+General Options
+\layout Standard
+
+General options enable certain port features and optimizations.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pgen-bank Instructs the port to insert BANKSEL directives before instructions
+ that use the Bank Select Register (BSR).
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pomit-config-words Instructs the port to omit the generation of the configurati
+on words.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pomit-ivt Instructs the port to omit the generation of the interrupt vectors
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pleave-reset-vector Used in conjuction with the previous command, instructs
+ the port NOT to omit the reset vector.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\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
+
+
+\emph on
+small
+\emph default
+ Selects small stack model.
+ 8 bit stack and frame pointers.
+ Supports 256 bytes stack size.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\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 ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\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 Subsubsection
+
+Debugging Options
+\layout Standard
+
+Debugging options enable extra debugging information in the output files.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug-xtra Similar to --debug, but dumps more information.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\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
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-pcode-verbose Enable pcode debugging information in translation.
+\layout Subsection
+
+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="2" 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">
+\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
+
+pic18fxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+MCU Identification.
+
+\emph on
+xxxx
+\emph default
+ is the microcontrol identification number, i.e.
+ 452, 6620, etc
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Subsection
+
+Directories
+\layout Standard
+
+PIC16 port uses the following directories for searching header files and
+ libraries.
+\layout Standard
+\align center
+
+\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
+
+\layout Standard
+
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Target
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+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
+
+PIC16 specific headers
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Compiler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+-I
+\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
+
+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
+
+PIC16 specific libraries
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="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
+
+-L
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Subsection
+
+Pragmas
+\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 since gplink does not support yet stack.
+ When the gplink issue is resolved the pragma will be deprecated
+\begin_inset Foot
+collapsed true
+
+\layout Standard
+
+
+\emph on
+It is important to initialize the stack, otherwise strange things can happen.
+ Stack is not initialized by default because there are some sources that
+ do not require it.
+ (like library sources)
+\end_inset
+
+.
+\newline
+The stack pragma should be used only once in a project.
+ Multiple pragmas may result in indeterminate behaviour of the program.
+\newline
+If you omit setting the pragma the port emits a warning message before linking.
+ If not initializing the stack is desired ignore the message.
+\layout LyX-Code
+
+Example:
+\layout LyX-Code
+
+\layout LyX-Code
+
+/* initializes stack at RAM address 0x5ff*/
+\layout LyX-Code
+
+#pragma stack 0x5ff
+\layout LyX-Code
+
+\layout Subsection
+
+Header Files
+\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 necessery if the soruce accesses them.
+ It can be included by adding the following line in the beginning of the
+ file:
+\layout LyX-Code
+
+#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
+
+The libraries that pic16 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://gputils.sourceforge.net}
+
+\end_inset
+
+.
+\layout Subsection
+
+Memory Models
+\layout Standard
+
+The following memory models are supported by PIC16 port:
+\layout Itemize
+
+small model
+\layout Itemize
+
+large model
+\layout Standard
+
+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
+
+\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
+
+16-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+\layout Standard
+
+data pointers
+\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">
+\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
+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 4.5.6) contain no reference to pointers,
+ so they can be used with both memory models.
+\layout Subsection
+
+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
+
+FSR2 is assigned as frame pointer
+\layout Standard
+
+The following stack models are supported by PIC16 port
+\layout Itemize
+
+small model
+\layout Itemize
+
+large model
+\layout Standard
+
+
+\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
+
+\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
+
+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
+
+
+\series bold
+Currently stack and frame pointers should be initialized explicit by the
+ user at the desired Data RAM position (see 4.5.5 Pragma Stack).
+ Uninitialized stack and frame pointers can result in unexpected behavior
+ of the resulting binary.
+\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
+
+When entering an interrupt, currently the PIC16 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 Chapter
+
+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.
+ Sdcdb is available on Unix platforms only.
+\layout Section
+
+Compiling for Debugging
+\layout Standard
+
+The \SpecialChar \-
+\SpecialChar \-
+debug option must be specified for all files for which debug information
+ is to be generated.
+ The complier 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 Section
+
+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.
+\layout Section
+
+Starting the Debugger
+\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 Section
+
+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 Section
+
+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 the
+ next sections.
+\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 Section
+
+Interfacing 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
+
+\SpecialChar ~
+
+\family typewriter
+
+\newline
+;; Current Listing ::
+\newline
+;;key\SpecialChar ~
+\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 ~
+\SpecialChar ~
+--------
+\newline
+;;
+\newline
+;; n\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
+;; b\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
+;; c\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
+;; s\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 ~
+ sdcdb-whatis-c-sexp\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB ptypecommand for data at
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ buffer point
+\newline
+;; x\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ sdcdbsrc-delete\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB Delete all breakpoints if no arg
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+given or delete arg (C-u arg x)
+\newline
+;; m\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ sdcdbsrc-frame\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB Display current frame if no arg,
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+given or display frame arg
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+buffer point
+\newline
+;; !\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
+;; p\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ sdcdb-print-c-sexp\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB print command for data at
+\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 ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ buffer point
+\newline
+;; g\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
+;; t\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
+;; C-c C-f\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
+;; C-x SPC\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
+;; ESC t\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
+;; ESC m\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ sdcdbsrc-srcmode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ Toggle list mode
+\newline
+;;
+\newline
+
+\layout Chapter
+\pagebreak_top
+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' before doing any operation.
+ This promotion can be omitted, if the result is the same.
+ The effect of the promotion rules together with the sign-extension is often
+ supprising:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+unsigned char uc = 0xfe;
+\newline
+if (uc * uc < 0) /* this is true! */
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+....
+\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
+
+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
+
+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
+
+Reducing the size of division, multiplication & modulus operations can reduce
+ code size substantially.
+ Take the following code for example.
+\begin_deeper
+\layout Verse
+
+
+\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
+
+
+\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
+
+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
+
+Tools
+\begin_inset LatexCommand \index{Tools}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="12" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="center" 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
+
+Name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Purpose
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
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+
+Simulator for various architectures
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+
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+\end_inset
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+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
+
+header file conversion
+\end_inset
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+\end_inset
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+\layout Standard
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+header file conversion
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+\end_inset
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+Assembler
+\end_inset
+</cell>
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+\begin_inset Text
+
+\layout Standard
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+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
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+\end_inset
+</cell>
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+\end_inset
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+
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+\begin_inset Text
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+aslink
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+Linker
+\end_inset
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+
+\family roman
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+\noun off
+\color none
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+\layout Standard
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+Linker
+\end_inset
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+\begin_inset Text
+
+\layout Standard
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+
+\family roman
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+\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">
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+\layout Standard
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+packihx
+\end_inset
+</cell>
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+
+\layout Standard
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+ihx packer
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+
+\layout Standard
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+
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+\bar no
+\noun off
+\color none
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+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
\newline
+\layout Section
+
+Documentation
+\begin_inset LatexCommand \index{Documentation}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="10" columns="2">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
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+Subject / Title
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+
+\layout Standard
+
+Where to get / filename
+\end_inset
+</cell>
+</row>
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+
+\layout Standard
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+SDCC Compiler User Guide
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+You're reading it right now
+\end_inset
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+</row>
+<row topline="true">
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+\begin_inset Text
+
+\layout Standard
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+Changelog of SDCC
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/Changelog
+\end_inset
+</cell>
+</row>
+<row topline="true">
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+\begin_inset Text
+
+\layout Standard
+
+ASXXXX Assemblers and ASLINK 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
+\end_inset
+</cell>
+</row>
+<row topline="true">
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+
+\layout Standard
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+SDCC regression test
+\begin_inset LatexCommand \index{Regression test}
+
+\end_inset
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+
+\end_inset
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+
+\layout Standard
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+sdcc/doc/test_suite_spec.pdf
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+
+\layout Standard
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+Various notes
+\end_inset
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+
+\layout Standard
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+
+\layout Standard
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+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">
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+
+\layout Standard
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+sdcc/debugger/README
+\end_inset
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+
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+Software simulator for microcontrollers
+\end_inset
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\family default
-Variations of this case however will
-\emph on
-not
+\series default
+\shape default
+\size default
\emph default
- be recognized.
- It is a standard C expression, so I heartily recommend this 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.:
+\bar default
+\noun default
+\color default
+/index.html
+\end_inset
+</cell>
+</row>
+<row topline="true">
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+\layout Standard
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+Temporary notes on the pic16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port
+\end_inset
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+\begin_inset Text
+
+\layout Standard
+
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+\end_inset
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+</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
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+\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
-\newline
+\layout Section
+
+Related open source tools
+\begin_inset LatexCommand \index{Related tools}
+
+\end_inset
+
+
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="11" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="block" valignment="top" leftline="true" width="30line%">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
+<row topline="true" bottomline="true">
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+\begin_inset Text
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+Name
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Purpose
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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 typewriter
-xyz = gint + ((gint >> 15) & 1);
-\family default
+gpsim
+\begin_inset LatexCommand \index{gpsim (pic simulator)}
-\newline
+\end_inset
-\newline
-will still be recognized.
-\layout Subsubsection
-Peep-hole Optimizer
+\end_inset
+</cell>
+<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@microsoft.com).
- A default set of rules are compiled into the compiler, additional rules
- may be added with the
-\emph on
----peep-file <filename>
-\emph default
- option.
- The rule language is best illustrated with examples.
-\newline
+PIC simulator
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\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
-}
-\family default
-\newline
+\begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
-\newline
-The above rule will change the following assembly sequence:
-\newline
+\end_inset
-\newline
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-mov r1,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-mov a,r1
-\family default
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\newline
-to
-\newline
+gputils
+\begin_inset LatexCommand \index{gputils (pic tools)}
-\newline
+\end_inset
-\family typewriter
-mov r1,a
-\family default
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-Note: All occurrences of a
-\emph on
-%n
-\emph default
- (pattern variable) must denote the same string.
- With the above rule, the assembly sequence:
-\newline
+\layout Standard
-\newline
+GNU PIC utilities
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-mov r1,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-mov a,r2
-\family default
+\layout Standard
-\newline
-\newline
-will remain unmodified.
-\newline
+\begin_inset LatexCommand \url{http://gputils.sourceforge.net/}
-\newline
-Other special case optimizations may be added by the user (via
-\emph on
----peep-file option
-\emph default
-).
- E.g.
- some variants of the 8051 MCU 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
-\family default
+\end_inset
-\newline
-\newline
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family typewriter
-replace { lcall %1 } by { acall %1 }
-\newline
-replace { ljmp %1 } by { ajmp %1 }
-\family default
+\layout Standard
-\newline
+flP5
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
-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:
-\newline
+PIC programmer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\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'
-\newline
-\family default
+\begin_inset LatexCommand \url{http://digilander.libero.it/fbradasc/FLP5.html}
+
+\end_inset
+
-\newline
-<assembly sequence> := assembly instruction (each instruction including
- labels must be on a separate line).
-\newline
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\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:
-\newline
+\layout Standard
-\newline
+indent
+\begin_inset LatexCommand \index{indent (source formatting tool)}
-\family typewriter
-replace restart {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-pop %1
-\newline
-\SpecialChar ~
-\SpecialChar ~
-push %1 } by {
-\newline
-\SpecialChar ~
-\SpecialChar ~
-; nop
-\newline
-}
-\family default
+\end_inset
-\newline
-\newline
-Note that the replace pattern cannot be a blank, but can be a comment line.
- Without the 'restart' option only the inner most 'pop' 'push' pair would
- be eliminated, i.e.:
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-pop ar1
-\newline
-\SpecialChar ~
-\SpecialChar ~
-pop ar2
-\newline
-\SpecialChar ~
-\SpecialChar ~
-push ar2
-\newline
-\SpecialChar ~
-\SpecialChar ~
-push ar1
-\family default
+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
-\newline
+\layout Standard
-\newline
-would result in:
-\newline
-\newline
+\begin_inset LatexCommand \url{http://home.hccnet.nl/d.ingamells/beautify.html}
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-pop ar1
-\newline
-\SpecialChar ~
-\SpecialChar ~
-; nop
-\newline
-\SpecialChar ~
-\SpecialChar ~
-push ar1
-\family default
+\end_inset
-\newline
-\newline
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\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:
-\newline
+\layout Standard
-\newline
+srecord
+\begin_inset LatexCommand \index{srecord (tool)}
-\family typewriter
-\SpecialChar ~
-\SpecialChar ~
-; nop
-\newline
-\SpecialChar ~
-\SpecialChar ~
-; nop
-\family default
+\end_inset
-\newline
-\newline
-A conditional function can be attached to a rule.
- Attaching rules are somewhat more involved, let me illustrate this with
- an example.
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-replace {
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-ljmp %5
-\newline
-%2:
-\newline
-} by {
-\newline
-\SpecialChar ~
- \SpecialChar ~
- \SpecialChar ~
-sjmp %5
-\newline
-%2:
-\newline
-} if labelInRange
-\family default
+Object file conversion, checksumming, ...
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\newline
-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.
- 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 also 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 ---peep-file option.
-\layout Subsection
-Pragmas
+\begin_inset LatexCommand \url{http://srecord.sourceforge.net/}
+
+\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 supports the following #pragma directives.
- This directives are applicable only at a function level.
-\layout Itemize
+objdump
+\begin_inset LatexCommand \index{objdump (tool)}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Object file conversion, ...
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+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
+
+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">
+\begin_inset Text
+
+\layout Standard
+
+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 \url{http://www.doxygen.org}
+
+\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
-SAVE - this will save all the current options.
-\layout Itemize
+kdevelop
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-RESTORE - will restore the saved options from the last save.
- Note that SAVES & RESTOREs cannot be nested.
- SDCC uses the same buffer to save the options each time a SAVE is called.
-\layout Itemize
+\layout Standard
-NOGCSE - will stop global subexpression elimination.
-\layout Itemize
+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
-NOINDUCTION - will stop loop induction optimizations.
-\layout Itemize
+\layout Standard
-NOJTBOUND - will not generate code for boundary value checking, when switch
- statements are turned into jump-tables.
-\layout Itemize
-NOOVERLAY - the compiler will not overlay the parameters and local variables
- of a function.
-\layout Itemize
+\begin_inset LatexCommand \url{http://www.kdevelop.org}
-NOLOOPREVERSE - Will not do loop reversal optimization
-\layout Itemize
+\end_inset
-EXCLUDE NONE | {acc[,b[,dpl[,dph]]] - The exclude pragma disables generation
- of pair of push/pop instruction in ISR function (using interrupt keyword).
- 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.
-\layout Itemize
-NOIV - Do not generate interrupt 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).
-\layout Itemize
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-CALLEE-SAVES function1[,function2[,function3...]] - The compiler by default
- uses a caller saves convention for register saving across function calls,
- however this can cause unneccessary register pushing & popping when calling
- small functions from larger functions.
- This option can be used to switch the register saving convention for the
- function names specified.
- The compiler will not save registers when calling these functions, extra
- code will be generated 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 future the compiler (with interprocedural analysis) will be able to
- determine the appropriate scheme to use for each function call.
- If ---callee-saves command line option is used, the function names specified
- in #pragma\SpecialChar ~
-CALLEE-SAVES is appended to the list of functions specified inthe
- command line.
\layout Standard
-The pragma's are intended to be used to turn-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.
-\newline
-
-\newline
+splint
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
-\family typewriter
-#pragma SAVE /* save the current settings */
-\newline
-#pragma NOGCSE /* turnoff global subexpression elimination */
-\newline
-#pragma NOINDUCTION /* turn off induction optimizations */
-\newline
-int foo ()
-\newline
-{
-\newline
-\SpecialChar ~
- \SpecialChar ~
- ...
-
-\newline
-\SpecialChar ~
- \SpecialChar ~
- /* large code */
-\newline
-\SpecialChar ~
- \SpecialChar ~
- ...
-
-\newline
-}
-\newline
-#pragma RESTORE /* turn the optimizations back on */
-\family default
+\end_inset
-\newline
-\newline
-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 Subsection
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\emph on
-<pending: this is messy and incomplete>
-\emph default
- Library Routines
-\layout Enumerate
+Statically checks c sources
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Compiler support routines (_gptrget, _mulint etc)
-\layout Enumerate
+\layout Standard
-Stdclib functions (puts, printf, strcat etc)
-\layout Enumerate
-Math functions (sin, pow, sqrt etc)
-\layout Subsection
+\begin_inset LatexCommand \url{http://www.splint.org}
-Interfacing with Assembly Routines
-\layout Subsubsection
+\end_inset
-Global Registers used for Parameter Passing
-\layout Standard
-The compiler always uses the global registers
-\emph on
-DPL,DPH,B
-\emph default
-and
-\emph on
- ACC
-\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 ---stack-auto is used) or in the internal / external ram
- (depending on the memory model).
-
-\layout Subsubsection
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Assembler Routine(non-reentrant)
\layout Standard
-In the following example the function cfunc calls an assembler routine asm_func,
- which takes two parameters.
-\newline
-
-\newline
-
-\family typewriter
-extern int asm_func(unsigned char, unsigned char);
-\newline
+ddd
+\begin_inset LatexCommand \index{ddd (debugger)}
-\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
-}
-\newline
-\newline
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family default
-The corresponding assembler function is:
-\newline
+\layout Standard
-\newline
+Debugger, serves nicely as GUI to sdcdb
+\begin_inset LatexCommand \index{sdcdb (debugger)}
-\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 a,dpl
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-add a,_asm_func_PARM_2
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov dpl,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov dpl,#0x00
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-ret
-\newline
+\end_inset
-\newline
+ (Unix only)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family default
-Note here that the return values 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
+
+\begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
+
\end_inset
-dpl
-\begin_inset Quotes erd
+
\end_inset
+</cell>
+</row>
+</lyxtabular>
- for One bye parameter,
-\begin_inset Quotes eld
\end_inset
-dptr
-\begin_inset Quotes erd
+
+\newline
+
+\layout Section
+
+Related documentation / recommended reading
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="block" valignment="top" leftline="true" width="30line%">
+<column alignment="center" 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
+
+Name
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- if two bytes,
-\begin_inset Quotes eld
+\layout Standard
+
+Subject / Title
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-b,dptr
-\begin_inset Quotes erd
+\layout Standard
+
+Where to get
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- for three bytes and
-\begin_inset Quotes eld
+\layout Standard
+
+
+\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
+
+C Reference Card
+\begin_inset LatexCommand \index{C Reference card}
-acc,b,dptr
-\begin_inset Quotes erd
\end_inset
- for four bytes, the varible name for the second parameter will be _<function_na
-me>_PARM_2.
-\newline
+, 2 pages
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
-Assemble the assembler routine with the following command:
-\newline
+\layout Standard
-\newline
-\family sans
-\series bold
-asx8051 -losg asmfunc.asm
-\newline
+\begin_inset LatexCommand \url{http://www.refcards.com/about/c.html}
-\newline
+\end_inset
-\family default
-\series default
-Then compile and link the assembler routine to the C source file with the
- following command:
-\newline
-\newline
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\family sans
-\series bold
-sdcc cfunc.c asmfunc.rel
-\layout Subsubsection
+\layout Standard
+
+c-faq
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Assembler Routine(reentrant)
\layout Standard
-In this case the second parameter onwards will be passed on the stack, the
- parameters are pushed from right to left i.e.
- after the call the left most parameter will be on the top of the stack.
- Here is an example:
-\newline
+C-FAQ-list
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-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
+\begin_inset LatexCommand \url{http://www.eskimo.com/~scs/C-faq/top.html}
-\newline
-int main()
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-return c_func(10,9);
-\newline
-}
-\newline
+\end_inset
-\family default
-\newline
-The corresponding assembler routine is:
-\newline
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-.globl _asm_func
-\newline
-_asm_func:
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-push _bp
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov _bp,sp
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov r2,dpl
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov a,_bp
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-clr c
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-add a,#0xfd
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov r0,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-add a,#0xfc
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov r1,a
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov a,@r0
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-add a,r2
-\newline
-\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
-\newline
+\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
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family default
-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 Subsection
+vendor
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-External Stack
\layout Standard
-The external stack is located at the start of the external ram segment,
- and is 256 bytes in size.
- When ---xstack option is used to compile the program, the parameters and
- local variables of all reentrant functions are allocated in this area.
- This option is provided for programs with large stack space requirements.
- When used with the ---stack-auto option, all parameters and local variables
- are allocated on the external stack (note support libraries will need to
- be recompiled with the same options).
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-The compiler outputs the higher order address byte of the external ram segment
- into PORT P2, therefore when using the External Stack option, this port
- MAY NOT be used by the application program.
-\layout Subsection
+Revision history of datasheet
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-ANSI-Compliance
\layout Standard
-Deviations from the compliancy.
-\layout Itemize
+vendor
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-functions are not always reentrant.
-\layout Itemize
+\layout Standard
-structures 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.:
-\family typewriter
+S.
+ S.
+ Muchnick
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\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
+
+\layout Standard
+
+bookstore (very dedicated, probably read other books first)
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
-\newline
\newline
-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) /* is 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
-}
-\layout Itemize
-'long long' (64 bit integers) not supported.
+\layout Section
+
+Some Questions
+\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
-'double' precision floating point not supported.
+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
-No support for setjmp and longjmp (for now).
+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
-Old K&R style function declarations are NOT allowed.
-\newline
+if you solved the problem, will the marketing department be happy?
+\layout Itemize
-\family typewriter
+if the marketing department is happy, will customers be happy?
+\layout Itemize
-\newline
-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 ~
-\SpecialChar ~
-\SpecialChar ~
-...
-
-\newline
-}
+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
-functions declared as pointers must be dereferenced during the call.
-\newline
+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
-\family typewriter
+is your project adequately positioned in that magic triangle: fame, fortune,
+ fun?
+\layout Standard
-\newline
-int (*foo)();
-\newline
-...
-
-\newline
-/* has to be called like this */
-\newline
-(*foo)(); /* ansi standard allows calls to be made like 'foo()' */
-\layout Subsection
+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
-Cyclomatic Complexity
\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
+burnout is bad for electronic devices, programmers and motorcycle tyres
+\end_inset
-\newline
-SDCC uses the following formula to compute the complexity:
-\newline
+.
+ Chances are you didn't want to hear some of them...
+\layout Chapter
-\layout Standard
+Support
+\begin_inset LatexCommand \index{Support}
-complexity = (number of edges in control flow graph) - (number of nodes
- in control flow graph) + 2;
-\newline
+\end_inset
-\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
-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
+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
-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'.
-\layout Itemize
+The SDCC project is hosted on the SDCC sourceforge site at
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
-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.
-\layout Itemize
+\end_inset
-NEVER jump into a LOOP.
-\layout Itemize
+.
+ You'll find the complete set of mailing lists
+\begin_inset LatexCommand \index{Mailing list}
-Declare the variables to be local whenever possible, especially loop control
- variables (induction).
-\layout Itemize
+\end_inset
-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
+, forums, bug reporting system, patch submission
+\begin_inset LatexCommand \index{Patch submission}
-Reducing the size of division, multiplication & modulus operations can reduce
- code size substantially.
- Take the following code for example.
-\family typewriter
+\end_inset
-\newline
+ system, download
+\begin_inset LatexCommand \index{download}
-\newline
-foobar(unsigned int p1, unsigned char ch)
-\newline
-{
-\newline
- unsigned char ch1 = p1 % ch ;
-\newline
- ....
-
-\newline
-}
-\newline
+\end_inset
-\family default
+ area and cvs code repository
+\begin_inset LatexCommand \index{cvs code repository}
-\newline
-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
-\newline
+\end_inset
-\family typewriter
+ there.
+\layout Section
-\newline
-foobar(unsigned int p1, unsigned char ch)
-\newline
-{
-\newline
- unsigned char ch1 = (unsigned char)p1 % ch ;
-\newline
- ....
-
-\newline
-}
-\newline
+Reporting Bugs
+\begin_inset LatexCommand \index{Bug reporting}
-\family default
+\end_inset
-\newline
-It would substantially reduce the code generated (future versions of the
- compiler will be smart enough to detect such optimization oppurtunities).
-\layout Subsection
-Notes on MCS51 memory layout
-\layout Standard
+\begin_inset LatexCommand \index{Reporting bugs}
-The 8051 family of micro controller have a minimum of 128 bytes of internal
- memory which is structured as follows
-\newline
+\end_inset
-\newline
-- Bytes 00-1F - 32 bytes to hold up to 4 banks of the registers R7 to R7
-
-\newline
-- Bytes 20-2F - 16 bytes to hold 128 bit variables and
-\newline
-- Bytes 30-7F - 60 bytes for general purpose use.
-\newline
-\newline
-Normally the SDCC compiler will only utilise the first bank of registers,
- but it is possible to specify that other banks of registers should be used
- in interrupt routines.
- By default, the compiler will place the stack after the last bank of used
- registers, i.e.
- if the first 2 banks of registers are used, it will position the base of
- the internal stack at address 16 (0X10).
- This implies that as the stack grows, it will use up the remaining register
- banks, and the 16 bytes used by the 128 bit variables, and 60 bytes for
- general purpose use.
\layout Standard
-By default, the compiler uses the 60 general purpose bytes to hold "near
- data".
- The compiler/optimiser may also declare some Local Variables in this area
- to hold local data.
-
+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
-If any of the 128 bit variables are used, or near data is being used then
- care needs to be taken to ensure that the stack does not grow so much that
- it starts to over write either your bit variables or "near data".
- There is no runtime checking to prevent this from happening.
-\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
-The amount of stack being used is affected by the use of the "internal stack"
- to save registers before a subroutine call is made (---stack-auto will
- declare parameters and local variables on the stack) and the number of
- nested subroutines.
\layout Standard
-If you detect that the stack is over writing you data, then the following
- can be done.
- ---xstack will cause an external stack to be used for saving registers
- and (if ---stack-auto is being used) storing parameters and local variables.
- However this will produce more code which will be slower to execute.
+\backslash
+/
+\end_inset
+
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
+
+\end_inset
+
+ 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.
-\layout Standard
+\layout Enumerate
----stack-loc will allow you specify the start of the stack, i.e.
- you could start it after any data in the general purpose area.
- However this may waste the memory not used by the register banks and if
- the size of the "near data" increases, it may creep into the bottom of
- the stack.
-\layout Standard
+Specify the exact command you use to run SDCC, or attach your Makefile.
+
+\layout Enumerate
----stack-after-data, similar to the ---stack-loc, but it automatically places
- the stack after the end of the "near data".
- Again this could waste any spare register space.
-\layout Standard
+Specify the SDCC version (type "
+\family sans
+\series bold
+sdcc -v
+\family default
+\series default
+"), your platform, and operating system.
+
+\layout Enumerate
----data-loc allows you to specify the start address of the near data.
- This could be used to move the "near data" further away from the stack
- giving it more room to grow.
- This will only work if no bit variables are being used and the stack can
- grow to use the bit variable space.
-\newline
+Provide an exact copy of any error message or incorrect output.
+
+\layout Enumerate
-\newline
-Conclusion.
-\newline
+Put something meaningful in the subject of your message.
+\layout Standard
-\newline
-If you find that the stack is over writing your bit variables or "near data"
- then the approach which best utilised the internal memory is to position
- the "near data" after the last bank of used registers or, if you use bit
- variables, after the last bit variable by using the ---data-loc, e.g.
- if two register banks are being used and no bit variables, ---data-loc
- 16, and use the ---stack-after-data option.
+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
-If bit variables are being used, another method would be to try and squeeze
- the data area in the unused register banks if it will fit, and start the
- stack after the last bit variable.
+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
-Retargetting for other MCUs.
-\layout Standard
+Requesting Features
+\begin_inset LatexCommand \label{sub:Requesting-Features}
-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
+\end_inset
-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 ---dumpraw option.
-\layout Itemize
+\begin_inset LatexCommand \index{Feature request}
-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
+\end_inset
-\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
-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 is essential for register allocation, since these computati
-on determines which of these iTemps will be assigned to registers, and for
- how long.
-\layout Itemize
+\begin_inset LatexCommand \index{Requesting features}
-Phase five is register allocation.
- There are two parts to this process.
-\newline
+\end_inset
-\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
+\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
+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}
-As mentioned in the optimization section the peep-hole optimizer is rule
- based system, which can reprogrammed for other MCUs.
+\end_inset
+
+.
\layout Section
-SDCDB - Source Level Debugger
+Submitting patches
\layout Standard
-SDCC is distributed with a source level debugger.
- The debugger uses a command line interface, the command repertoire of the
- debugger has been kept as close to gdb (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
+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}
-Compiling for Debugging
-\layout Standard
+\end_inset
-The \SpecialChar \-
-\SpecialChar \-
-debug option must be specified for all files for which debug information
- is to be generated.
- The complier generates a .cdb file for each of these files.
- The linker updates the .cdb file with the address information.
- This .cdb is used by the debugger.
-\layout Subsection
+:
+\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
-How the Debugger Works
+\end_inset
+
+.
\layout Standard
-When the ---debug option is specified the compiler generates extra symbol
- information some of which are put into the the assembler source and some
- are put into the .cdb file, the linker updates the .cdb file 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.
-\layout Subsection
+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
-Starting the Debugger
-\layout Standard
+\begin_inset Quotes sld
+\end_inset
-The debugger can be started using the following command line.
- (Assume the file you are debugging has the file name foo).
-\newline
+diff -Naur unmodified_directory modified_directory >my_changes.patch
+\begin_inset Quotes srd
+\end_inset
-\newline
+\family default
+\series default
+ will be fine, otherwise
\family sans
\series bold
-sdcdb foo
-\newline
-\family default
-\series default
+\begin_inset Quotes sld
+\end_inset
-\newline
-The debugger will look for the following files.
-\layout Itemize
+diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
+\begin_inset Quotes srd
+\end_inset
-foo.c - the source file.
-\layout Itemize
-foo.cdb - the debugger symbol information file.
-\layout Itemize
+\series default
+
+\family default
+will do.
+\layout Section
-foo.ihx - the intel hex format object file.
-\layout Subsection
+Getting Help
+\layout Standard
-Command Line Options.
-\layout Itemize
+These links should take you directly to the
+\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
----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 ---directory option should be ---directory=/home/src1:/home/src2.
- Note there can be no spaces in the option.
-
-\layout Itemize
+\end_inset
--cd <directory> - change to the <directory>.
-\layout Itemize
--fullname - used by GUI front ends.
-\layout Itemize
+\begin_inset Foot
+collapsed false
--cpu <cpu-type> - this argument is passed to the simulator please see the
- simulator docs for details.
-\layout Itemize
+\layout Standard
--X <Clock frequency > this options is passed to the simulator please see
- the simulator docs for details.
-\layout Itemize
+Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
+ automated messages (mid 2003)
+\end_inset
--s <serial port file> passed to simulator see the simulator docs for details.
-\layout Itemize
+ and the
+\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
--S <serial in,out> passed to simulator see the simulator docs for details.
-\layout Subsection
+\end_inset
-Debugger Commands.
+, lists and forums are archived and searchable so if you are lucky someone
+ already had a similar problem.
+\layout Section
+
+ChangeLog
\layout Standard
-As mention earlier the command interface for the debugger has been deliberately
- 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.
-\layout Subsubsection
+You can follow the status of the cvs version
+\begin_inset LatexCommand \index{version}
-break [line | file:line | function | file:function]
-\layout Standard
+\end_inset
-Set breakpoint at specified line or function:
-\newline
+ of SDCC by watching the Changelog
+\begin_inset LatexCommand \index{Changelog}
-\newline
+\end_inset
-\family sans
-\series bold
-sdcdb>break 100
-\newline
-sdcdb>break foo.c:100
-\newline
-sdcdb>break funcfoo
+ in the cvs-repository
\newline
-sdcdb>break foo.c:funcfoo
-\layout Subsubsection
-clear [line | file:line | function | file:function ]
+\size footnotesize
+
+\begin_inset LatexCommand \htmlurl{http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/sdcc/sdcc/ChangeLog?rev=HEAD&content-type=text/plain}
+
+\end_inset
+
+.
+\layout Section
+
+Release policy
+\begin_inset LatexCommand \index{Release policy}
+
+\end_inset
+
+
\layout Standard
-Clear breakpoint at specified line or function:
-\newline
+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}
-\newline
+\end_inset
-\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
+, 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}
-continue
-\layout Standard
+\end_inset
-Continue program being debugged, after breakpoint.
-\layout Subsubsection
+.
+\layout Section
-finish
-\layout Standard
+Examples
+\begin_inset LatexCommand \index{Examples}
+
+\end_inset
-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
+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://www.qsl.net/dl9sec/SDCC_OKR.html}
-info [break | stack | frame | registers ]
-\layout Itemize
+\end_inset
-info break - list all breakpoints
-\layout Itemize
+
+\emph default
+web site or at
+\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
-info stack - show the function call stack.
-\layout Itemize
+\end_inset
-info frame - show information about the current execution frame.
-\layout Itemize
+.
+\layout Comment
-info registers - show content of all registers.
-\layout Subsubsection
+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
-step
-\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?
+\layout Section
-Step program until it reaches a different source line.
-\layout Subsubsection
+Quality control
+\begin_inset LatexCommand \index{Quality control}
-next
-\layout Standard
+\end_inset
-Step program, proceeding through subroutine calls.
-\layout Subsubsection
-run
\layout Standard
-Start debugged program.
-\layout Subsubsection
+The compiler is passed through nightly compile and build checks.
+ The so called
+\shape italic
+regression tests
+\shape default
-ptype variable
-\layout Standard
+\begin_inset LatexCommand \index{Regression test}
-Print type information of the variable.
-\layout Subsubsection
+\end_inset
-print variable
-\layout Standard
+ 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}
-print value of variable.
-\layout Subsubsection
+\end_inset
-file filename
+
+\shape default
+ about this.
\layout Standard
-load the given file name.
- Note this is an alternate method of loading file for debugging.
-\layout Subsubsection
+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
-frame
-\layout Standard
+\begin_inset Quotes sld
+\end_inset
-print information about current frame.
-\layout Subsubsection
+make test-mcs51
+\begin_inset Quotes srd
+\end_inset
-set srcmode
-\layout Standard
-Toggle between C source & assembly source.
-\layout Subsubsection
+\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}
-! simulator command
+\end_inset
+
+ checking corner cases of SDCC or if you plan to submit patches
+\begin_inset LatexCommand \index{Patch submission}
+
+\end_inset
+
+.
\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 pic port uses a different set of regression tests, you'll find them
+ in the directory
+\shape italic
+sdcc/src/regression
+\shape default
+.
+\layout Chapter
+\pagebreak_top
+SDCC Technical Data
+\layout Section
+
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
+\end_inset
+
-quit.
\layout Standard
-"Watch me now.
- Iam going Down.
- My name is Bobby Brown"
+SDCC performs a host of standard optimizations in addition to some MCU specific
+ optimizations.
+
\layout Subsection
-Interfacing with XEmacs.
-\layout Standard
+Sub-expression Elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
-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
+\end_inset
-\newline
-\family typewriter
-(load-file sdcdbsrc.el)
-\family default
+\layout Standard
-\newline
+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
-\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
+\family typewriter
+i = x + y + 1;
\newline
+j = x + y;
+\layout Standard
-\family sans
-\series bold
-ESC-x sdcdbsrc
-\family default
-\series default
+will be translated to
+\layout Verse
-\newline
+\family typewriter
+iTemp = x + y;
\newline
-You will prompted to enter the file name to be debugged.
-
-\newline
-
+i = iTemp + 1;
\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
+j = iTemp;
+\layout Standard
-sdcdbsrc-cpu-type '51
-\layout Itemize
+Some subexpressions are not as obvious as the above example, e.g.:
+\layout Verse
-sdcdbsrc-frequency '11059200
-\layout Itemize
-sdcdbsrc-serial nil
+\family typewriter
+a->b[i].c = 10;
+\newline
+a->b[i].d = 11;
\layout Standard
-The following is a list of key mapping for the debugger interface.
-\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
-\SpecialChar ~
\family typewriter
-
+iTemp = a->b[i];
\newline
-;; Current Listing ::
+iTemp.c = 10;
\newline
-;;key\SpecialChar ~
-\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
+iTemp.d = 11;
+\layout Standard
+
+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
+
+
+\layout Verse
+
+
+\family typewriter
+int global;
\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 ~
-\SpecialChar ~
---------
+
\newline
-;;
+void f () {
\newline
-;; n\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
+int i;
\newline
-;; b\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- sdcdb-back-from-src\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+i = 1; \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB back command
+/* dead store */
\newline
-;; c\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
+global = 1;\SpecialChar ~
+/* dead store */
\newline
-;; s\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+global = 2;
+\newline
\SpecialChar ~
\SpecialChar ~
+return;
+\newline
\SpecialChar ~
\SpecialChar ~
+global = 3;\SpecialChar ~
+/* unreachable */
+\newline
+}
+\layout Standard
+
+will be changed to
+\layout Verse
+
+
+\family typewriter
+int global;
+\newline
+
+\newline
+void f () {
+\newline
\SpecialChar ~
- sdcdb-step-from-src\SpecialChar ~
\SpecialChar ~
+global = 2;
+\newline
\SpecialChar ~
\SpecialChar ~
+return;
+\newline
+}
+\layout Subsection
+
+Copy-Propagation
+\begin_inset LatexCommand \index{Copy propagation}
+
+\end_inset
+
+
+\layout Verse
+
+
+\family typewriter
+int f() {
+\newline
\SpecialChar ~
\SpecialChar ~
+int i, j;
+\newline
\SpecialChar ~
\SpecialChar ~
+i = 10;
+\newline
\SpecialChar ~
\SpecialChar ~
-SDCDB step command
+j = i;
\newline
-;; ?\SpecialChar ~
\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
+
+
+\layout Standard
+
+Two types of loop optimizations are done by SDCC loop invariant lifting
+ and strength reduction 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 ~
- sdcdb-whatis-c-sexp\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++)
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB ptypecommand for data at
+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++) {
\newline
-;;\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ar[itemp1] = itemp2;
+\newline
\SpecialChar ~
\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 ~
\SpecialChar ~
\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 ~
\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 ~
- buffer point
-\newline
-;; x\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 changes switch statements to jump tables
+\begin_inset LatexCommand \index{jump tables}
+
+\end_inset
+
+ when the following conditions are true.
+
+\layout Itemize
+
+The case labels are in numerical sequence, the labels need not be in order,
+ and the starting number need not be one or zero.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+switch(i) {\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-delete\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB Delete all breakpoints if no arg
+switch (i) {
\newline
-;;\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 4: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 0: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 5: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-given or delete arg (C-u arg x)
-\newline
-;; m\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 1: ...
+
+\newline
\SpecialChar ~
- sdcdbsrc-frame\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 3: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB Display current frame if no arg,
-\newline
-;;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 2: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 6: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 3: ...
+
+\newline
+}\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-given or display frame arg
-\newline
-;;\SpecialChar ~
\SpecialChar ~
\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 at least three, since it takes two conditional
+ statements to handle the boundary conditions.
+\layout Itemize
+
+The number of case labels is less than 84, since each label takes 3 bytes
+ and a jump-table can be utmost 256 bytes long.
+\layout Standard
+
+Switch statements which have gaps in the numeric sequence or those that
+ have more that 84 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 ~
\SpecialChar ~
+case 2: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 3: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 4: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 9: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 10: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 11: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
-buffer point
+case 12: ...
+
+\newline
+}
+\layout Standard
+
+If the above switch statement is broken down into two switch statements
+\layout Verse
+
+
+\family typewriter
+switch (i) {
\newline
-;; !\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+case 1: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 2: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 3: ...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 4: ...
+
+\newline
+}
+\layout Standard
+
+and
+\layout Verse
+
+
+\family typewriter
+switch (i) {
+\newline
\SpecialChar ~
\SpecialChar ~
+case 9:\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
- sdcdbsrc-goto-sdcdb\SpecialChar ~
\SpecialChar ~
+case 10:\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 11:\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+case 12:\SpecialChar ~
+...
+
+\newline
+}
+\layout Standard
+
+then both the switch statements will be implemented using jump-tables whereas
+ the unmodified switch statement will not be.
+ You might also consider inserting dummy cases 0 and 5 to 8 in this example.
+
+\newline
+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 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 ~
-Goto the SDCDB output buffer
+a
\newline
-;; p\SpecialChar ~
+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 ~
- sdcdb-print-c-sexp\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
+\newline
+mov\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;
+\newline
+
+\series bold
+unsigned
+\series default
\SpecialChar ~
\SpecialChar ~
+int j;
+\newline
+...
+
+\newline
+i = ((i << 4) | (i >> 4));
+\family default
+
+\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
+
+\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
+\emph on
+
+\emph default
+so little-endian is the more efficient byte order.
+\end_inset
+
+
+\begin_inset LatexCommand \index{little-endian}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Endianness}
+
+\end_inset
+
+ format (i.e.
+ lowest order first).
+\layout Subsection
+
+Highest Order Bit
+\begin_inset LatexCommand \index{Highest 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).
+ SDCC recognizes the following expression to yield the highest order bit
+ and generates optimized code for it, e.g.:
+\layout Verse
+
+
+\family typewriter
+unsigned int gint;
+\newline
+
+\newline
+foo () {
+\newline
\SpecialChar ~
\SpecialChar ~
-SDCDB print command for data at
+unsigned char hob;
\newline
-;;\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
+hob = (gint >> 15) & 1;
+\newline
\SpecialChar ~
\SpecialChar ~
+..
+
+\newline
+}
+\layout Standard
+
+will generate the following code:
+\layout Verse
+
+
+\family typewriter
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 61 ;\SpecialChar ~
+ hob.c 7
+\newline
+000A E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- buffer point
-\newline
-;; g\SpecialChar ~
\SpecialChar ~
+ 62\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ a,(_gint + 1)
+\newline
+000C 23\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-goto-sdcdb\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Goto the SDCDB output buffer
-\newline
-;; t\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 63\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ rl\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-mode\SpecialChar ~
+ a
+\newline
+000D 54 01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 64\SpecialChar ~
\SpecialChar ~
-Toggles Sdcdbsrc mode (turns it off)
-\newline
-;;
-\newline
-;; C-c C-f\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ anl\SpecialChar ~
\SpecialChar ~
- sdcdb-finish-from-src\SpecialChar ~
+ a,#0x01
+\newline
+000F F5*02\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB finish command
-\newline
-;;
-\newline
-;; C-x SPC\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-break\SpecialChar ~
+ 65\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_hob_1_1,a
+\layout Standard
+
+Variations of this case however will
+\emph on
+not
+\emph default
+ be recognized.
+ It is a standard C expression, so I heartily recommend this 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
+
+
+\family typewriter
+xyz = gint + ((gint >> 15) & 1);
+\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@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
\SpecialChar ~
\SpecialChar ~
+mov %1,a
+\newline
\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 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 ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ \SpecialChar ~
+ <assembly sequence> '
+\backslash
+n'
+\newline
\SpecialChar ~
-Set break for line with point
+ \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
-;; ESC t\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-mode\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
+
+
+\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 ~
+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
+
+Deviations from the compliance:
+\layout Itemize
+
+functions are not always reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+.
+\layout Itemize
+
+structures 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
+
+
+\family typewriter
+struct s { ...
+ };
+\newline
+struct s s1, s2;
+\newline
+foo()
+\newline
+{
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-Toggle Sdcdbsrc mode
+s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
\newline
-;; ESC m\SpecialChar ~
\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 ~
- sdcdbsrc-srcmode\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+...
+
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+return rets;/* is invalid in SDCC although allowed in ANSI */
+\newline
+}
+\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
+
+No support for setjmp
+\begin_inset LatexCommand \index{setjmp (not supported)}
+
+\end_inset
+
+ and longjmp
+\begin_inset LatexCommand \index{longjmp (not supported)}
+
+\end_inset
+
+ (for now).
+\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 ~
\SpecialChar ~
\SpecialChar ~
- Toggle list mode
+...
+
\newline
-;;
-\family default
+}
+\end_deeper
+\layout Itemize
+
+functions declared as pointers
+\begin_inset LatexCommand \index{Pointer (to function)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{function pointers}
+
+\end_inset
+ must be dereferenced during the call.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+int (*foo)();
+\newline
+...
+
+\newline
+/* has to be called like this */
\newline
-
+(*foo)(); /* ANSI standard allows calls to be made like 'foo()' */
+\end_deeper
\layout Section
-Other Processors
-\layout Subsection
+Cyclomatic Complexity
+\begin_inset LatexCommand \index{Cyclomatic complexity}
+
+\end_inset
+
-The Z80 and gbz80 port
\layout Standard
-SDCC can target both the Zilog Z80 and the Nintendo Gameboy's Z80-like gbz80.
- The port is incomplete - long support is incomplete (mul, div and mod are
- unimplimented), and both float and bitfield support is missing.
- Apart from that the code generated is correct.
+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
-As always, the code is the authoritave reference - see z80/ralloc.c and z80/gen.c.
- The stack frame is similar to that generated by the IAR Z80 compiler.
- IX is used as the base pointer, HL is used as a temporary register, and
- BC and DE are available for holding varibles.
- IY is currently unusued.
- Return values are stored in HL.
- One bad side effect of using IX as the base pointer is that a functions
- stack frame is limited to 127 bytes - this will be fixed in a later version.
+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
-Support
+Retargetting for other Processors
\layout Standard
-SDCC has grown to be a large project.
- The compiler alone (without the preprocessor, assembler and linker) is
- about 40,000 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 Subsection
+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
-Reporting Bugs
\layout Standard
-Send an email to the mailing list at 'user-sdcc@sdcc.sourceforge.net' or 'devel-sd
-cc@sdcc.sourceforge.net'.
- Bugs will be fixed ASAP.
- When reporting a bug, it is very useful to include a small test program
- 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 ---dumpall option can sometimes be useful
- in locating optimization problems.
+\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
+
+\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
+
+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 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 atricle published in Circuit Cellar MagaZine
+This is an excerpt from an article published in Circuit Cellar Magazine
in august 2000.
- It's a little outdated (the compiler is much more efficient now and user/devell
-oper friendly), but pretty well exposes the guts of it all.
+ 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
\layout Paragraph*
-Parsing
+Parsing
+\begin_inset LatexCommand \index{Parsing}
+
+\end_inset
+
+
\layout Standard
-Parsing the input source file and creating an AST (Annotated Syntax Tree).
+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.
\layout Paragraph*
Generating iCode
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+
\layout Standard
Intermediate code generation.
C source functions.
\layout Paragraph*
-Optimizations.
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
+\end_inset
+
+.
\layout Standard
Bulk of the target independent optimizations is performed in this phase.
\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
\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
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 general-purpose register.
+ to the accumulator instead of a general-purpose register.
\layout Paragraph*
Code generation
\layout Paragraph*
ICode Example
+\begin_inset LatexCommand \index{iCode}
+
+\end_inset
+
+
\layout Standard
This section shows some details of iCode.
The example C code does not do anything useful; it is used as an example
to illustrate the intermediate code generated by the compiler.
-\newline
+\layout Verse
-\newline
\family typewriter
1.\SpecialChar ~
7.\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-short i=10; /* dead initialization eliminated */
+short i=10; \SpecialChar ~
+\SpecialChar ~
+/* dead initialization eliminated */
\newline
8.\SpecialChar ~
\SpecialChar ~
\newline
15.\SpecialChar ~
\SpecialChar ~
-for (i = 0, j = 10 ; i < 10 ; i++, j---) {
+for (i = 0, j = 10 ; i < 10 ; i++, j
+\family default
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-
+\family typewriter
+) {
\newline
16.\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mul += i * 3; /* this multiplication remains */
+mul += i * 3; \SpecialChar ~
+\SpecialChar ~
+/* this multiplication remains */
\newline
18.\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-gint += j * 3;/* this multiplication changed to addition */
+gint += j * 3;\SpecialChar ~
+\SpecialChar ~
+/* this multiplication changed to addition */
\newline
19.\SpecialChar ~
\SpecialChar ~
\newline
21.\SpecialChar ~
}
-\newline
-
-\newline
+\layout Standard
-\family default
In addition to the operands each iCode contains information about the filename
and line it corresponds to in the source file.
The first field in the listing should be interpreted as follows:
generated temporary b) user defined variable c) a constant value.
Note that local variables and parameters are replaced by compiler generated
temporaries.
- Live ranges are computed only for temporaries (i.e.
+ Live ranges
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+ are computed only for temporaries (i.e.
live ranges are not computed for global variables).
- Registers are allocated for temporaries only.
+ Registers
+\begin_inset LatexCommand \index{Register allocation}
+
+\end_inset
+
+ are allocated for temporaries only.
Operands are formatted in the following manner:
\newline
In addition the allocator also takes into consideration the type and usage
of a temporary, for example itemp6 is a pointer to near space and is used
as to fetch data from (i.e.
- used in GET_VALUE_AT_ADDRESS) so it is allocated a pointer registers (r0).
+ used in GET_VALUE_AT_ADDRESS) so it is allocated a pointer register (r0).
Some short lived temporaries are allocated to special registers which have
meaning to the code generator e.g.
iTemp13 is allocated to a pseudo register CC which tells the back end that
the temporary is used only for a conditional jump the code generation makes
use of this information to optimize a compare and jump ICode.
\newline
-There are several loop optimizations performed by the compiler.
+There are several loop optimizations
+\begin_inset LatexCommand \index{Loop optimization}
+
+\end_inset
+
+ performed by the compiler.
It can detect induction variables iTemp21(i) and iTemp23(j).
- Also note the compiler does selective strength reduction, i.e.
+ Also note the compiler does selective strength reduction
+\begin_inset LatexCommand \index{Strength reduction}
+
+\end_inset
+
+, i.e.
the multiplication of an induction variable in line 18 (gint = j * 3) is
changed to addition, a new temporary iTemp17 is allocated and assigned
a initial value, a constant 3 is then added for each iteration of the loop.
- The compiler does not change the multiplication in line 17 however since
- the processor does support an 8 * 8 bit multiplication.
+ The compiler does not change the multiplication
+\begin_inset LatexCommand \index{Multiplication}
+
+\end_inset
+
+ in line 17 however since the processor does support an 8 * 8 bit multiplication.
\newline
-Note the dead code elimination optimization eliminated the dead assignments
- in line 7 & 8 to I and sum respectively.
+Note the dead code elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
+
+\end_inset
+
+ optimization eliminated the dead assignments in line 7 & 8 to I and sum
+ respectively.
\newline
\layout Standard
\SpecialChar ~
\SpecialChar ~
ret
-\size default
-
\newline
\layout Section
+A few words about basic block successors, predecessors and dominators
+\layout Standard
+
+Successors are basic blocks
+\begin_inset LatexCommand \index{Basic blocks}
+
+\end_inset
+
+ that might execute after this basic block.
+\newline
+Predecessors are basic blocks that might execute before reaching this basic
+ block.
+\newline
+Dominators are basic blocks that WILL execute before reaching this basic
+ block.
+\newline
+
+\layout Standard
+
+[basic block 1]
+\layout Standard
+
+if (something)
+\layout Standard
+
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+[basic block 2]
+\layout Standard
+
+else
+\layout Standard
+
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+[basic block 3]
+\layout Standard
+
+[basic block 4]
+\newline
+
+\layout Standard
+
+a) succList of [BB2] = [BB4], of [BB3] = [BB4], of [BB1] = [BB2,BB3]
+\layout Standard
+
+b) predList of [BB2] = [BB1], of [BB3] = [BB1], of [BB4] = [BB2,BB3]
+\layout Standard
+
+c) domVect of [BB4] = BB1 ...
+ here we are not sure if BB2 or BB3 was executed but we are SURE that BB1
+ was executed.
+\layout Chapter
+
Acknowledgments
\layout Standard
This document was initially written by Sandeep Dutta
\layout Standard
-All product names mentioned herein may be trademarks of their respective
- companies.
+All product names mentioned herein may be trademarks
+\begin_inset LatexCommand \index{Trademarks}
+
+\end_inset
+
+ of their respective companies.
+\layout Section*
+
+Alphabetical index
+\layout Standard
+
+To avoid confusion, the installation and building options for SDCC itself
+ (chapter 2) are not part of the index.
\layout Standard
projects / fw / sdcc / blobdiff