\size normal
-SDCC 2.5.3
+SDCC 2.5.5
\size footnotesize
\newline
$Revision$
\layout Comment
-The above strings enclosed in $ are automatically updated by cvs
+The above strings enclosed in $ are automatically updated by Subversion
\layout Standard
\newline
SDCC also comes with a companion source level debugger SDCDB, the debugger
currently uses ucSim a freeware simulator for 8051 and other micro-controllers.
+ SDCDB and ucSim are currently not available on Win32 platforms.
\newline
Some of the other tools (simulator and assembler) included with SDCC contain
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.
+ is available directly from Subversion on https://svn.sourceforge.net/svnroot/sdcc
+/trunk/sdcc.
\layout Section
Wishes for the future
\series medium
Download the source package
\series default
- either from the SDCC CVS repository or from the nightly snapshots
+ either from the SDCC Subversion repository or from the nightly snapshots
\series medium
, it will be named something like sdcc
\series default
later
\layout Itemize
-cvs ; only if you use CVS access
+svn ; only if you use Subversion access
\layout Standard
If you want to develop something you'll need:
\series medium
Download the source package
\series default
- either from the SDCC CVS repository or from the
+ either from the SDCC Subversion repository or from the
\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
\end_inset
\newline
WARNING: Visual studio is very picky with line terminations; it expects
the 0x0d, 0x0a DOS style line endings, not the 0x0a Unix style line endings.
- When using the CVS repository it's easiest to configure the cvs client
- to convert automatically for you.
+ When using the Subversion repository it's easiest to configure the svn
+ client to convert automatically for you.
If however you are getting a message such as "This makefile was not generated
by Developer Studio etc.
etc.
a
\emph default
rray
-\begin_inset LatexCommand \index{fpga (field programmable gate array)}
+\begin_inset LatexCommand \index{FPGA (field programmable gate array)}
\end_inset
+\begin_inset Quotes srd
+\end_inset
+
+ or
+\begin_inset LatexCommand \url{http://sf.net/projects/fpgac}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{FpgaC ((subset of) C to FPGA compiler)}
+
+\end_inset
+
+
+\begin_inset Quotes sld
+\end_inset
+
+have you ever heard of an open source compiler that compiles a subset of
+ C for an FPGA?
\begin_inset Quotes srd
\end_inset
\layout Itemize
s51 - The ucSim 8051 simulator.
+ Not available on Win32 platforms.
\layout Itemize
sdcdb - The source debugger.
+ Not available on Win32 platforms.
\layout Itemize
packihx - A tool to pack (compress) Intel hex files.
.
It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
XA51 family.
+ S51 is currently not available on Win32 platfors.
\layout Subsection
sdcdb - Source Level Debugger
\end_inset
, but can be easily changed to use other simulators.
-
+ Sdcdb is currently not available on Win32 platfors.
\layout Chapter
Using SDCC
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-xstack-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> By default the external stack
+\begin_inset LatexCommand \index{xstack}
+
+\end_inset
+
+ is placed after the pdata segment.
+ Using this option the xstack can be placed anywhere in the external memory
+ space of the 8051.
+ The value entered can be in Hexadecimal or Decimal format, e.g.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack-loc 0x8000 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc 32768.
+ The provided value should not overlap any other memory areas such as the
+ pdata or xdata segment and with enough space for the current application.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-
\begin_inset ERT
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-medium
+\begin_inset LatexCommand \index{-\/-model-medium}
+
+\end_inset
+
+
+\series default
+ Generate code for Medium 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.
+ It must also be used when invoking the linker.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-
\begin_inset ERT
\end_inset
).
+ This is the
+\series bold
+default
+\series default
+ storage class for the Medium Memory model, e.g.:
\layout Verse
if it is not reentrant.
Furthermore nonreentrant functions should not be called from the main program
while the interrupt service routine might be active.
-
+ They also must not be called from low priority interrupt service routines
+ while a high priority interrupt service routine might be active.
+ You could use semaphores or make the function
+\emph on
+ critical
+\emph default
+ if all parameters are passed in registers.
\newline
\newline
\layout Subsubsection
-Small and Large
+Small, Medium and Large
\layout Standard
-SDCC allows two memory models for MCS51 code,
+SDCC allows three memory models for MCS51 code,
\shape slanted
-small
+small, medium
\shape default
and
\shape slanted
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.
-
+ The library routines supplied with the compiler are compiled as small,
+ medium and large.
+ The compiled library modules are contained in separate directories as small,
+ medium and large so that you can link to the appropriate set.
\layout Standard
-When the 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
+When the medium or large model is used all variables declared without a
+ storage class will be allocated into the external ram, this includes all
+ parameters and local variables (for non-reentrant
\begin_inset LatexCommand \index{reentrant}
\end_inset
\begin_inset Tabular
-<lyxtabular version="3" rows="10" columns="2">
+<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">
\layout Standard
+SDCC_MODEL_MEDIUM
+\begin_inset LatexCommand \index{SDCC\_MODEL\_MEDIUM}
+
+\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-medium
+\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}
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS)
+gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
\layout Standard
Here is a
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS)
+mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib
\layout Standard
Please note that indentations within a
Makefile
\family default
have to be done with a tabulator character.
+\layout Subsection
+
+Command-line options
+\layout Standard
+
+Besides the switches common to all SDCC backends, the PIC14 port accepts
+ the following options (for an updated list see sdcc -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-help):
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug-extra emit debug info in assembly output
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-pcode-opt disable (slightly faulty) optimization on pCode
+\layout Subsection
+
+The library
+\layout Subsubsection
+
+error: missing definition for symbol
+\begin_inset Quotes sld
+\end_inset
+
+__gptrget1
+\begin_inset Quotes srd
+\end_inset
+
+
+\layout Standard
+
+The PIC14 port uses library routines to provide more complex operations
+ like multiplication, division/modulus and (generic) pointer dereferencing.
+ In order to add these routines to your project, you must link with PIC14's
+
+\family typewriter
+libsdcc.lib
+\family default
+.
+ For single source file projects this is done automatically, more complex
+ projects must add
+\family typewriter
+libsdcc.lib
+\family default
+ to the linker's arguments.
+ Make sure you also add an include path for the library (using the -I switch
+ to the linker)!
+\layout Subsubsection
+
+Processor mismatch in file
+\begin_inset Quotes sld
+\end_inset
+
+XXX
+\begin_inset Quotes srd
+\end_inset
+
+.
+\layout Standard
+
+This warning can usually be ignored due to the very good compatibility amongst
+ 14 bit PIC devices.
+\layout Standard
+
+You might also consider recompiling the library for your specific device
+ by changing the ARCH=p16f877 (default target) entry in
+\family typewriter
+device/lib/pic/Makefile.in
+\family default
+ and
+\family typewriter
+device/lib/pic/Makefile
+\family default
+ to reflect your device.
+ This might even improve performance for smaller devices as unneccesary
+ BANKSELs migth be removed.
+\layout Subsection
+
+Known bugs
+\layout Subsubsection
+
+initialized data
+\layout Standard
+
+Currently, data can only be initialized if it resides in the source file
+ together with
+\emph on
+main()
+\emph default
+.
+ Data in other source files will silently
+\series bold
+not
+\series default
+ be initialized.
\layout Section
The PIC16
/
\end_inset
+-optimize-df Analyze the dataflow of the generated code and improve it.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
-obanksel=nn Set optimization level for inserting BANKSELs.
\newline
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.
+ Sdcdb is currently not available on Win32 platforms.
\layout Section
Compiling for Debugging
The .eps File
\size footnotesize
-\begin_inset LatexCommand \url{http://cvs.sourceforge.net/viewcvs.py/*checkout*/sdcc/sdcc/doc/figures/ddd_example.eps}
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.eps}
\end_inset
\end_inset
- area and cvs code repository
-\begin_inset LatexCommand \index{cvs code repository}
+ area and Subversion code repository
+\begin_inset LatexCommand \index{Subversion code repository}
\end_inset
ChangeLog
\layout Standard
-You can follow the status of the cvs version
+You can follow the status of the Subversion version
\begin_inset LatexCommand \index{version}
\end_inset
\end_inset
- in the cvs-repository
+ in the Subversion repository
\newline
\size footnotesize
-\begin_inset LatexCommand \htmlurl{http://cvs.sf.net/cgi-bin/viewcvs.cgi/*checkout*/sdcc/sdcc/ChangeLog?rev=HEAD&content-type=text/plain}
+\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
\end_inset
sdcc/src/regression
\shape default
.
-\layout Chapter
-\pagebreak_top
-SDCC Technical Data
\layout Section
-Optimizations
-\begin_inset LatexCommand \index{Optimizations}
-
-\end_inset
-
-
+Use of SDCC in Education
\layout Standard
-SDCC performs a host of standard optimizations in addition to some MCU specific
- optimizations.
-
-\layout Subsection
+In short:
+\emph on
+highly
+\emph default
+ encouraged
+\begin_inset Foot
+collapsed false
-Sub-expression Elimination
-\begin_inset LatexCommand \index{Subexpression elimination}
+\layout Standard
+the phrase "use in education" might evoke the association "
+\emph on
+only
+\emph default
+ fit for use in education".
+ This connotation is not intended but nevertheless risked as the licensing
+ of SDCC makes it difficult to offer educational discounts
\end_inset
-
+.
+ If your rationales are to:
+\layout Enumerate
+
+give students a chance to understand the
+\emph on
+complete
+\emph default
+ steps of code generation
+\layout Enumerate
+
+have a curriculum that can be extended for years.
+ Then you could use an fpga board as target and your curriculum will seamlessly
+ extend from logic synthesis (
+\begin_inset LatexCommand \url[http://www.opencores.org]{opencores.org}
+
+\end_inset
+
+,
+\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
+
+\end_inset
+
+), over assembly programming, to C to FPGA compilers (
+\begin_inset LatexCommand \url[FPGAC]{http://sf.net/projects/fpgac}
+
+\end_inset
+
+) and to C.
+\layout Enumerate
+
+be able to insert excursions about skills like using a revision control
+ system, submitting/applying patches, using a type-setting (as opposed to
+ word-processing) engine LyX/LaTeX, using
+\begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
+
+\end_inset
+
+, following some
+\begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
+
+\end_inset
+
+, understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open
+ Source Software, CPU simulation, compiler regression tests
+\begin_inset LatexCommand \index{Regression test}
+
+\end_inset
+
+.
+
+\newline
+And if there should be a shortage of ideas then you can always point students
+ to the ever-growing feature request list
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
+
+\end_inset
+
+.
+\layout Enumerate
+
+not tie students to a specific host platform and instead allow them to use
+ a host platform of
+\emph on
+their
+\emph default
+ choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
+ eventually
+\begin_inset LatexCommand \url[OLPC]{http://wiki.laptop.org/wiki/One_Laptop_per_Child}
+
+\end_inset
+
+)
+\layout Enumerate
+
+not encourage students to use illegal copies of educational software
+\layout Enumerate
+
+be immune to licensing/availability/price changes of the chosen tool chain
+\layout Enumerate
+
+be able to change to a new target platform without having to adopt a new
+ tool chain
+\layout Enumerate
+
+have complete control over and insight into the tool chain
+\layout Enumerate
+
+make your students aware about the pros and cons of open source software
+ development
+\layout Enumerate
+
+give back to the public as you are probably at least partially publically
+ funded
+\layout Enumerate
+
+give students a chance to publically prove their skills and to possibly
+ see a world wide impact
+\layout Standard
+
+then SDCC is probably among the first choices.
+ Well, probably SDCC might be the only choice.
+\layout Chapter
+\pagebreak_top
+SDCC Technical Data
+\layout Section
+
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC performs a host of standard optimizations in addition to some MCU specific
+ optimizations.
+
+\layout Subsection
+
+Sub-expression Elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
+
+\end_inset
+
+
\layout Standard
The compiler does local and
Highest Order Bit
\begin_inset LatexCommand \index{Highest Order Bit}
+\end_inset
+
+ / Any Order Bit
+\begin_inset LatexCommand \index{Any Order Bit}
+
\end_inset
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
+ Also obtaining any other order bit is not uncommon.
+ SDCC recognizes the following expressions to yield the highest order bit
and generates optimized code for it, e.g.:
\layout Verse
\newline
\SpecialChar ~
\SpecialChar ~
-unsigned char hob;
+unsigned char hob1, aob1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+bit hob2, hob3, aob2, aob3;
\newline
\SpecialChar ~
\SpecialChar ~
\newline
\SpecialChar ~
\SpecialChar ~
-hob = (gint >> 15) & 1;
+hob1 = (gint >> 15) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob2 = (gint >> 15) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob3 = gint & 0x8000;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob1 = (gint >> 9) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob2 = (gint >> 8) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob3 = gint & 0x0800;
\newline
\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\SpecialChar ~
-@\SpecialChar ~
-microsoft.com).
- A default set of rules are compiled into the compiler, additional rules
- may be added with the
-\emph on
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--peep-file
-\begin_inset LatexCommand \index{-\/-peep-file}
-
-\end_inset
-
- <filename>
-\emph default
- option.
- The rule language is best illustrated with examples.
-\layout Verse
-
-
-\family typewriter
-replace {
+ _foo_hob1_1_1,a
\newline
\SpecialChar ~
\SpecialChar ~
-mov %1,a
-\newline
\SpecialChar ~
\SpecialChar ~
-mov a,%1
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 66 ;\SpecialChar ~
+ hob.c 8
\newline
-} by {
+0011 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 67\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
+0013 33\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov %1,a
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 68\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rlc\SpecialChar ~
+\SpecialChar ~
+ a
\newline
-}
-\layout Standard
-
-The above rule will change the following assembly
-\begin_inset LatexCommand \index{Assembler routines}
-
-\end_inset
+0014 92*00\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 69\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob2_1_1,c
+\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 ~
+ 66 ;\SpecialChar ~
+ hob.c 9
+\newline
+0016 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 67\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0018 33\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 68\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rlc\SpecialChar ~
+\SpecialChar ~
+ a
+\newline
+0019 92*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 69\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob3_1_1,c
+\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 ~
+ 70 ;\SpecialChar ~
+ hob.c 10
+\newline
+001B E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 71\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
+\newline
+001D 03\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 72\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rr\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ a
+\newline
+001E 54 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 73\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ anl\SpecialChar ~
+\SpecialChar ~
+ a,#0x01
+\newline
+0020 F5*03\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 74\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob1_1_1,a
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 75 ;\SpecialChar ~
+ hob.c 11
+\newline
+0022 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 76\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0024 13\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 77\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rrc\SpecialChar ~
+\SpecialChar ~
+ a
+\newline
+0025 92*02\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 78\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob2_1_1,c
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 79 ;\SpecialChar ~
+ hob.c 12
+\newline
+0027 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 80\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0029 A2 E3\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 81\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ c,acc[3]
+\newline
+002B 92*03\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 82\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob3_1_1,c
+\layout Standard
+
+Other variations of these cases however will
+\emph on
+not
+\emph default
+ be recognized.
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the highest order bit, (it is portable).
+ Of course it will be recognized even if it is embedded in other expressions,
+ e.g.:
+\layout Verse
+
+
+\family typewriter
+xyz = gint + ((gint >> 15) & 1);
+\layout Standard
+
+will still be recognized.
+\layout Subsection
+
+Higher Order Byte
+\begin_inset LatexCommand \index{Higher Order Byte}
+
+\end_inset
+
+ / Higher Order Word
+\begin_inset LatexCommand \index{Higher Order Word}
+
+\end_inset
+
+
+\layout Standard
+
+It is also frequently required to obtain a higher order byte or word of
+ a larger integral type (long, int or short types).
+ SDCC recognizes the following expressions to yield the higher order byte
+ or word and generates optimized code for it, e.g.:
+\layout Verse
+
+
+\family typewriter
+unsigned int gint;
+\newline
+unsigned long int glong;
+\newline
+
+\newline
+foo () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+unsigned char hob1, hob2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+unsigned int how1, how2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob1 = (gint >> 8) & 0xFF;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob2 = glong >> 24;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+how1 = (glong >> 16) & 0xFFFF;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+how2 = glong >> 8;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+..
+
+\newline
+}
+\layout Standard
+
+will generate the following code:
+\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 ~
+ 91 ;\SpecialChar ~
+ hob.c 15
+\newline
+0037 85*01*06\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 92\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob1_1_1,(_gint + 1)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 93 ;\SpecialChar ~
+ hob.c 16
+\newline
+003A 85*05*07\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 94\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob2_1_1,(_glong + 3)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 95 ;\SpecialChar ~
+ hob.c 17
+\newline
+003D 85*04*08\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 96\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_how1_1_1,(_glong + 2)
+\newline
+0040 85*05*09\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 97\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ (_foo_how1_1_1 + 1),(_glong + 3)
+\newline
+0043 85*03*0A\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 98\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_how2_1_1,(_glong + 1)
+\newline
+0046 85*04*0B\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 99\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ (_foo_how2_1_1 + 1),(_glong + 2)
+\layout Standard
+
+Again, variations of these cases may
+\emph on
+not
+\emph default
+ be recognized.
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the higher order byte/word, (it is portable).
+ Of course it will be recognized even if it is embedded in other expressions,
+ e.g.:
+\layout Verse
+
+
+\family typewriter
+xyz = gint + ((gint >> 8) & 0xFF);
+\layout Standard
+
+will still be recognized.
+\layout Subsection
+
+Peephole Optimizer
+\begin_inset LatexCommand \label{sub:Peephole-Optimizer}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Peephole optimizer}
+
+\end_inset
+
+
+\layout Standard
+
+The compiler uses a rule based, pattern matching and re-writing mechanism
+ for peep-hole optimization.
+ It is inspired by
+\emph on
+copt
+\emph default
+ a peep-hole optimizer by Christopher W.
+ Fraser (cwfraser\SpecialChar ~
+@\SpecialChar ~
+microsoft.com).
+ A default set of rules are compiled into the compiler, additional rules
+ may be added with the
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-peep-file
+\begin_inset LatexCommand \index{-\/-peep-file}
+
+\end_inset
+
+ <filename>
+\emph default
+ option.
+ The rule language is best illustrated with examples.
+\layout Verse
+
+
+\family typewriter
+replace {
+\newline
+\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
\end_deeper
\layout Itemize
+initialization of structure arrays must be fully braced.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+struct s { char x } a[] = {1, 2}; /* invalid in SDCC */
+\newline
+struct s { char x } a[] = {{1}, {2}}; /* OK */
+\end_deeper
+\layout Itemize
+
'long long
\begin_inset LatexCommand \index{long long (not supported)}
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_deeper
\layout Itemize
+Most enhancements in C99 are not supported, f.e.:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+\series bold
+inline
+\series default
+ int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
+ in C99 */
+\newline
+for (
+\series bold
+int
+\series default
+ i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
+\end_deeper
+\layout Itemize
+
Certain words that are valid identifiers in the standard may be reserved
words in SDCC unless the
\series bold
projects / fw / sdcc / blobdiff