\layout Section
-
+\pagebreak_top
Introduction
\layout Subsection
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}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{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.
If you can think of some more, please send them to the list.
\newline
-\newline
+\layout Section
-\emph on
-<pending: And then of course a proper index-table
-\begin_inset LatexCommand \index{index}
+Installation
+\begin_inset LatexCommand \index{Installation}
\end_inset
->
-\layout Section
-Installation
\layout Subsection
Configure Options
+\begin_inset LatexCommand \index{Configure Options}
+
+\end_inset
+
+
\layout Standard
The install paths, search paths and other options are defined when running
\layout Subsection
Install paths
+\begin_inset LatexCommand \index{Install paths}
+
+\end_inset
+
+
\layout Standard
1.
\layout Subsection
Search Paths
+\begin_inset LatexCommand \index{Search Paths}
+
+\end_inset
+
+
\layout Standard
Some search paths or parts of them are determined by configure variables
\layout Subsection
Building SDCC
+\begin_inset LatexCommand \index{Building SDCC}
+
+\end_inset
+
+
\layout Subsubsection
Building SDCC on Linux
\newline
\newline
-Download the file UnxUtils.zip.
+Download the file UnxUtils
+\begin_inset LatexCommand \index{UnxUtils}
+
+\end_inset
+
+.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!):
\family sans
\series bold
"sdcc ---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.
\layout Subsection
Install Trouble-shooting
+\begin_inset LatexCommand \index{Install Trouble-shooting}
+
+\end_inset
+
+
\layout Subsubsection
SDCC does not build correctly.
\layout Subsubsection
s51 - The Simulator
+\begin_inset LatexCommand \index{s51 - The Simulator}
+
+\end_inset
+
+
\layout Standard
S51 is a freeware, opensource simulator developed by Daniel Drotos (
\newline
\newline
-sourcefile.asm - Assembler source file created by the compiler
+sourcefile.asm
+\begin_inset LatexCommand \index{.asm}
+
+\end_inset
+
+ - Assembler source file created by the compiler
\newline
-sourcefile.lst - Assembler listing file created by the Assembler
+sourcefile.lst
+\begin_inset LatexCommand \index{.lst}
+
+\end_inset
+
+ - Assembler listing file created by the Assembler
\newline
-sourcefile.rst - Assembler listing file updated with linkedit information,
- created by linkage editor
+sourcefile.rst
+\begin_inset LatexCommand \index{.rst}
+
+\end_inset
+
+ - Assembler listing file updated with linkedit information, created by
+ linkage editor
\newline
-sourcefile.sym - symbol listing for the sourcefile, created by the assembler
+sourcefile.sym
+\begin_inset LatexCommand \index{.sym}
+
+\end_inset
+
+ - symbol listing for the sourcefile, created by the assembler
\newline
-sourcefile.rel - Object file created by the assembler, input to Linkage editor
+sourcefile.rel
+\begin_inset LatexCommand \index{.rel}
+
+\end_inset
+
+ - Object file created by the assembler, input to Linkage editor
\newline
-sourcefile.map - The memory map for the load module, created by the Linker
+sourcefile.map
+\begin_inset LatexCommand \index{.map}
+
+\end_inset
+
+ - The memory map for the load module, created by the Linker
\newline
-sourcefile.mem - A file with a summary of the memory ussage
+sourcefile.mem
+\begin_inset LatexCommand \index{.mem}
+
+\end_inset
+
+ - A file with a summary of the memory ussage
\newline
-sourcefile.ihx - The load module in Intel hex format (you can select the
- Motorola S19 format with ---out-fmt-s19)
+sourcefile.ihx
+\begin_inset LatexCommand \index{.ihx}
+
+\end_inset
+
+ - The load module in Intel hex format (you can select the Motorola S19
+ format with ---out-fmt-s19)
\newline
-sourcefile.adb - An intermediate file containing debug information needed
- to create the .cdb file (with ---debug)
+sourcefile.adb
+\begin_inset LatexCommand \index{.adb}
+
+\end_inset
+
+ - An intermediate file containing debug information needed to create the
+ .cdb file (with ---debug)
\newline
-sourcefile.cdb - An optional file (with ---debug) containing debug information
+sourcefile.cdb
+\begin_inset LatexCommand \index{.cdb}
+
+\end_inset
+
+ - An optional file (with ---debug) containing debug information
\newline
sourcefile.
- - (no extension) An optional AOMF51 file containing debug information (with
- ---debug)
+ - (no extension)
+\begin_inset LatexCommand \index{. (no extension)}
+
+\end_inset
+
+ An optional AOMF51 file containing debug information (with ---debug)
\newline
-sourcefile.dump* - Dump file to debug the compiler it self (with ---dumpall)
- (see section
+sourcefile.dump*
+\begin_inset LatexCommand \index{.dump*}
+
+\end_inset
+
+ - Dump file to debug the compiler it self (with ---dumpall) (see section
+
\begin_inset Quotes sld
\end_inset
\layout Subsubsection
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 how to create a
\emph on
.lib
+\begin_inset LatexCommand \index{.lib}
+
+\end_inset
+
+
\emph default
library file.
Libraries created in this manner can be included in the command line.
\layout Subsection
Command Line Options
+\begin_inset LatexCommand \index{Command Line Options}
+
+\end_inset
+
+
\layout Subsubsection
Processor Selection Options
+\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 MCS51 (8051) family of processors.
This is the default processor target.
\series bold
-mds390
+\begin_inset LatexCommand \index{-mds390}
+
+\end_inset
+
+
\series default
Generate code for the DS80C390 processor.
\layout List
\series bold
-mz80
+\begin_inset LatexCommand \index{-mz80}
+
+\end_inset
+
+
\series default
Generate code for the Z80 family of processors.
\layout List
\series bold
-mgbz80
+\begin_inset LatexCommand \index{-mgbz80}
+
+\end_inset
+
+
\series default
Generate code for the GameBoy Z80 processor.
\layout List
\series bold
-mavr
+\begin_inset LatexCommand \index{-mavr}
+
+\end_inset
+
+
\series default
Generate code for the Atmel AVR processor (In development, not complete).
\layout List
\series bold
-mpic14
+\begin_inset LatexCommand \index{-mpic14}
+
+\end_inset
+
+
\series default
Generate code for the PIC 14-bit processors (In development, not complete).
\layout List
\series bold
-mxa51
+\begin_inset LatexCommand \index{-mxa51}
+
+\end_inset
+
+
\series default
Generate code for the Philips XA51 processor (In development, not complete).
\layout Subsubsection
Preprocessor Options
+\begin_inset LatexCommand \index{Options Preprocessor}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Preprocessor Options}
+
+\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
\series bold
-D<macro[=value]>
+\begin_inset LatexCommand \index{-D<macro[=value]>}
+
+\end_inset
+
+
\series default
Command line definition of macros.
Passed to the pre processor.
\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.
\series bold
-C
+\begin_inset LatexCommand \index{-C}
+
+\end_inset
+
+
\series default
Tell the preprocessor not to discard comments.
Used with the `-E' option.
\series bold
-MM
+\begin_inset LatexCommand \index{-MM}
+
+\end_inset
+
+
\size large
\bar under
\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)'.
\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'
\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.
\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.
\series bold
-dN
+\begin_inset LatexCommand \index{-dN}
+
+\end_inset
+
+
\size large
\bar under
\layout Subsubsection
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 ~
---lib-path
+\begin_inset LatexCommand \index{-L ---lib-path}
+
+\end_inset
+
+
\bar under
\series default
\series bold
---xram-loc
\series default
+
+\begin_inset LatexCommand \index{---xram-loc}
+
+\end_inset
+
<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.
\series bold
---code-loc
\series default
+
+\begin_inset LatexCommand \index{---code-loc}
+
+\end_inset
+
<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.
\series bold
---stack-loc
\series default
+
+\begin_inset LatexCommand \index{---stack-loc}
+
+\end_inset
+
<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.
\series bold
---data-loc
\series default
+
+\begin_inset LatexCommand \index{---data-loc}
+
+\end_inset
+
<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.
\series bold
---idata-loc
\series default
+
+\begin_inset LatexCommand \index{---idata-loc}
+
+\end_inset
+
<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.
\series bold
---out-fmt-ihx
+\begin_inset LatexCommand \index{---out-fmt-ihx}
+
+\end_inset
+
+
\bar under
\series default
\series bold
---out-fmt-s19
+\begin_inset LatexCommand \index{---out-fmt-s19}
+
+\end_inset
+
+
\bar under
\series default
\layout Subsubsection
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
---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.
\series bold
---model-small
+\begin_inset LatexCommand \index{---model-small}
+
+\end_inset
+
+
\series default
\size large
\emph on
\layout Subsubsection
DS390 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
---model-flat24
\series default
+
+\begin_inset LatexCommand \index{---model-flat24}
+
+\end_inset
+
+
\size large
\emph on
\series bold
---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
\layout Subsubsection
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
---nogcse
-\series default
+\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.
\series bold
---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.
\series bold
---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 ~
\series bold
---nojtbound
+\begin_inset LatexCommand \index{---nojtbound}
+
+\end_inset
+
+
\size large
\bar under
\series bold
---noloopreverse
+\begin_inset LatexCommand \index{---noloopreverse}
+
+\end_inset
+
+
\series default
\size large
\series bold
nolabelopt
\series default
- Will not optimize labels (makes the dumpfiles more readable).
+
+\begin_inset LatexCommand \index{---nolabelopt }
+
+\end_inset
+
+Will not optimize labels (makes the dumpfiles more readable).
\layout List
\labelwidthstring 00.00.0000
\series bold
---no-xinit-opt
+\begin_inset LatexCommand \index{---no-xinit-opt}
+
+\end_inset
+
+
\series default
Will not memcpy initialized data in far space from code space.
This saves a few bytes in code space if you don't have initialized data.
\layout Subsubsection
Other Options
+\begin_inset LatexCommand \index{Options other}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Other Options}
+
+\end_inset
+
+
\layout List
\labelwidthstring 00.00.0000
\series bold
-c\SpecialChar ~
---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
\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.
\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
\series bold
-o\SpecialChar ~
-<path/file>
+<path/file>
+\begin_inset LatexCommand \index{-o <path/file>}
+
+\end_inset
+
+
\series default
The output path resp.
file where everything will be placed.
\series bold
---stack-auto
+\begin_inset LatexCommand \index{---stack-auto}
+
+\end_inset
+
+
\series default
\size large
\emph on
\series bold
---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.
\series bold
----callee-saves function1[,function2][,function3]....
+---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
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.
+CALLEE-SAVES
+\begin_inset LatexCommand \index{\#pragma CALLEE-SAVES}
+
+\end_inset
+
+.
\layout List
\labelwidthstring 00.00.0000
\series bold
---debug
+\begin_inset LatexCommand \index{---debug}
+
+\end_inset
+
+
\bar under
\series default
\series bold
---peep-file
\series default
+
+\begin_inset LatexCommand \index{---peep-file}
+
+\end_inset
+
<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.
\series bold
-S
+\begin_inset LatexCommand \index{-S}
+
+\end_inset
+
+
\size large
\bar under
\series bold
-Wa_asmOption[,asmOption]
\series default
+
+\begin_inset LatexCommand \index{-Wa\_asmOption[,asmOption]}
+
+\end_inset
+
...
Pass the asmOption to the assembler.
\layout List
\series bold
-Wl_linkOption[,linkOption]
\series default
+
+\begin_inset LatexCommand \index{-Wl\_linkOption[,linkOption]}
+
+\end_inset
+
...
Pass the linkOption to the linker.
\layout List
\series bold
---int-long-reent
+\begin_inset LatexCommand \index{---int-long-reent}
+
+\end_inset
+
+
\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.
\series bold
---cyclomatic
+\begin_inset LatexCommand \index{---cyclomatic}
+
+\end_inset
+
+
\bar under
\series default
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
\series bold
---float-reent
+\begin_inset LatexCommand \index{---float-reent}
+
+\end_inset
+
+
\bar under
\series default
\bar default
- Floating point library is compiled as reentrant.See section Installation
- for more details.
+ 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
---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.
\series bold
---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' function.
+ The compiler will generate a 'ret' upon return from the 'main'
+\begin_inset LatexCommand \index{main return}
+
+\end_inset
+
+ function.
The default option is to lock up i.e.
generate a 'ljmp '.
\layout List
\series bold
---no-peep
+\begin_inset LatexCommand \index{---no-peep}
+
+\end_inset
+
+
\series default
Disable peep-hole optimization.
\layout List
\series bold
---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 rules defined in the source file tree '<target>/peeph.def
-' before using this option.
+ 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 List
\labelwidthstring 00.00.0000
\series bold
---iram-size
\series default
-<Value> Causes the linker to check if the internal ram usage is within limits
- of the given value.
+<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
---xram-size
\series default
-<Value> Causes the linker to check if the external ram usage is within limits
- of the given value.
+<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
---code-size
\series default
-<Value> Causes the linker to check if the code usage is within limits of
- the given value.
+<Value>
+\begin_inset LatexCommand \index{---code-size<Value>}
+
+\end_inset
+
+ Causes the linker to check if the code usage is within limits of the given
+ value.
\layout List
\labelwidthstring 00.00.0000
\series bold
---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.
\series bold
---nostdlib
+\begin_inset LatexCommand \index{---nostdlib}
+
+\end_inset
+
+
\series default
This will prevent the compiler from passing on the default library path
to the linker.
\series bold
---verbose
+\begin_inset LatexCommand \index{---verbose}
+
+\end_inset
+
+
\series default
Shows the various actions the compiler is performing.
\layout List
\series bold
-V
+\begin_inset LatexCommand \index{-V}
+
+\end_inset
+
+
\series default
Shows the actual commands the compiler is executing.
\layout List
\series bold
---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 :).
\series bold
---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 helpfull for debugging the compiler itself.
\series bold
---less-pedantic
+\begin_inset LatexCommand \index{---less-pedantic}
+
+\end_inset
+
+
\series default
Disable some of the more pedantic warnings (jwk burps: please be more specific
here, please!)
\series bold
---print-search-dirs
+\begin_inset LatexCommand \index{---print-search-dirs}
+
+\end_inset
+
+
\series default
Display the directories in the compiler's search path
\layout Subsubsection
Intermediate Dump Options
+\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) generated
- by the compiler in human readable form at various stages of the compilation
- process.
+ 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.
\layout List
\labelwidthstring 00.00.0000
\series bold
---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 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.
+ 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
---dumpgcse
+\begin_inset LatexCommand \index{---dumpgcse}
+
+\end_inset
+
+
\series default
- Will create a dump of iCode's, after global subexpression elimination,
- into a file named
+ 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
\series bold
---dumpdeadcode
+\begin_inset LatexCommand \index{---dumpdeadcode}
+
+\end_inset
+
+
\series default
- Will create a dump of iCode's, after deadcode elimination, into a file
- named
+ Will create a dump of iCode's, after deadcode elimination
+\begin_inset LatexCommand \index{deadcode elimination}
+
+\end_inset
+
+, into a file named
\emph on
<source filename>.dumpdeadcode.
\layout List
\series bold
---dumploop
+\begin_inset LatexCommand \index{---dumploop}
+
+\end_inset
+
+
\series default
\size large
\size default
-Will create a dump of iCode's, after loop optimizations, into a file named
-
+Will create a dump of iCode's, after loop optimizations
+\begin_inset LatexCommand \index{loop optimizations}
+
+\end_inset
+
+, into a file named
\emph on
<source filename>.dumploop.
\layout List
\series bold
---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, into a file named
-
+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
\series bold
---dumlrange
+\begin_inset LatexCommand \index{---dumlrange}
+
+\end_inset
+
+
\series default
- Will dump the life ranges for all symbols.
+ Will dump the life ranges
+\begin_inset LatexCommand \index{life ranges}
+
+\end_inset
+
+ for all symbols.
\layout List
\labelwidthstring 00.00.0000
\series bold
---dumpregassign
+\begin_inset LatexCommand \index{---dumpregassign}
+
+\end_inset
+
+
\bar under
\series default
\bar default
-Will create a dump of iCode's, after register assignment, into a file named
-
+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
\series bold
---dumplrange
+\begin_inset LatexCommand \index{---dumplrange}
+
+\end_inset
+
+
\series default
Will create a dump of the live ranges of iTemp's
\layout List
\series bold
---dumpall
+\begin_inset LatexCommand \index{---dumpall}
+
+\end_inset
+
+
\size large
\bar under
\layout Subsection
Environment variables
+\begin_inset LatexCommand \index{Environment variables}
+
+\end_inset
+
+
\layout Standard
SDCC recognizes the following environment variables:
\series bold
SDCC_LEAVE_SIGNALS
+\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
+
+\end_inset
+
+
\series default
- SDCC installs a signal handler to be able to delete temporary files after
- an user break (^C) or an exception.
+ 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
\series bold
-TMP,\SpecialChar ~
-TEMP,\SpecialChar ~
+TMP
+\begin_inset LatexCommand \index{TMP}
+
+\end_inset
+
+,\SpecialChar ~
+TEMP
+\begin_inset LatexCommand \index{TEMP}
+
+\end_inset
+
+,\SpecialChar ~
TMPDIR
+\begin_inset LatexCommand \index{TMPDIR}
+
+\end_inset
+
+
\series default
Path, where temporary files will be created.
The order of the variables is the search order.
\series bold
SDCC_HOME
+\begin_inset LatexCommand \index{SDCC\_HOME}
+
+\end_inset
+
+
\series default
Path, see
\begin_inset Quotes sld
\series bold
SDCC_INCLUDE
+\begin_inset LatexCommand \index{SDCC\_INCLUDE}
+
+\end_inset
+
+
\series default
Path, see
\begin_inset Quotes sld
\series bold
SDCC_LIB
+\begin_inset LatexCommand \index{SDCC\_LIB}
+
+\end_inset
+
+
\series default
Path, see
\begin_inset Quotes sld
They can change or disappear very quickly, and will never be documentated.
\layout Subsection
-MCS51/DS390 Storage Class Language Extensions
+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
\layout Subsubsection
xdata
+\begin_inset LatexCommand \index{xdata}
+
+\end_inset
+
+
\layout Standard
Variables declared with this storage class will be placed in the extern
\layout Subsubsection
data
+\begin_inset LatexCommand \index{data}
+
+\end_inset
+
+
\layout Standard
This is the
\layout Subsubsection
idata
+\begin_inset LatexCommand \index{idata}
+
+\end_inset
+
+
\layout Standard
Variables declared with this storage class will be allocated into the indirectly
\layout Subsubsection
bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+
\layout Standard
This is a data-type and a storage class specifier.
bit iFlag;
\layout Subsubsection
-sfr / sbit
+sfr
+\begin_inset LatexCommand \index{sfr}
+
+\end_inset
+
+ / sbit
+\begin_inset LatexCommand \index{sbit}
+
+\end_inset
+
+
\layout Standard
Like the bit keyword,
\family typewriter
sfr at 0x80 P0; /* special function register P0 at location 0x80 */
\newline
-sbit at 0xd7 CY; /* CY (Carry Flag) */
+sbit at 0xd7 CY; /* CY (Carry Flag
+\begin_inset LatexCommand \index{Carry flag}
+
+\end_inset
+
+) */
\layout Subsection
Pointers
+\begin_inset LatexCommand \index{Pointers}
+
+\end_inset
+
+
\layout Standard
SDCC allows (via language extensions) pointers to explicitly point to any
- of the memory spaces of the 8051.
+ of the memory spaces
+\begin_inset LatexCommand \index{memory spaces}
+
+\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
code.
\layout Subsection
-Parameters & Local Variables
+Parameters
+\begin_inset LatexCommand \index{Parameters}
+
+\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
This in fact makes them
\emph on
static
+\begin_inset LatexCommand \index{static}
+
+\end_inset
+
+
\emph default
- so by default functions are non-reentrant.
+ so by default functions are non-reentrant
+\begin_inset LatexCommand \index{non-reentrant}
+
+\end_inset
+
+.
\newline
\newline
-They can be placed on the stack either by using the
+They can be placed on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ either by using the
\emph on
---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.:
\newline
\newline
\newline
-Local variables can be assigned storage classes and absolute addresses,
- e.g.:
+Local variables can be assigned storage classes and absolute
+\begin_inset LatexCommand \index{absolute}
+
+\end_inset
+
+ addresses, e.g.:
\newline
\newline
\layout Subsection
Overlaying
+\begin_inset LatexCommand \index{Overlaying}
+
+\end_inset
+
+
\layout Standard
For non-reentrant functions SDCC will try to reduce internal ram space usage
e segment if the function has
\emph on
no other function calls and the function is non-reentrant and the memory
- model is small.
+ model
+\begin_inset LatexCommand \index{memory model}
+
+\end_inset
+
+ is small.
\emph default
If an explicit storage class is specified for a local variable, it will
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.
+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.
+Also note that the compiler does not do any processing of inline
+\begin_inset LatexCommand \index{inline}
+
+\end_inset
+
+ 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.:
+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.:
\newline
\newline
\family typewriter
#pragma SAVE
\newline
-#pragma NOOVERLAY
+#pragma NOOVERLAY
+\begin_inset LatexCommand \index{\#pragma NOOVERLAY}
+
+\end_inset
+
+
\newline
void set_error(unsigned char errcd)
\newline
\newline
\newline
-void some_isr () interrupt 2 using 1
+void some_isr () interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ 2 using
+\begin_inset LatexCommand \index{using}
+
+\end_inset
+
+ 1
\newline
{
\newline
\layout Subsection
Interrupt Service Routines
+\begin_inset LatexCommand \index{Interrupt Service Routines}
+
+\end_inset
+
+
\layout Standard
SDCC allows interrupt service routines to be coded in C, with some extended
The number following the
\emph on
interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
\emph default
keyword is the interrupt number this routine will service.
The compiler will insert a call to this routine in the interrupt vector
(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.
+NOOVERLAY
+\begin_inset LatexCommand \index{\#pragma NOOVERLAY}
+
+\end_inset
+
+ 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
section) will have to be recompiled using the
\emph on
---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
---int-long-ren
\emph default
-t compiler option.
+t
+\begin_inset LatexCommand \index{---int-long-rent}
+
+\end_inset
+
+ compiler option.
\layout Standard
If you have multiple source files in your project, interrupt service routines
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.
+ SDCC will automatically adjust the interrupt vector table
+\begin_inset LatexCommand \index{ interrupt vector table}
+
+\end_inset
+
+ to the maximum interrupt number specified.
\newline
\layout Standard
If the interrupt service routine is defined without
\emph on
using
+\begin_inset LatexCommand \index{using}
+
+\end_inset
+
+
\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
\layout Subsection
Naked Functions
+\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.
+_naked
+\begin_inset LatexCommand \index{\_naked}
+
+\end_inset
+
+.
\emph default
The
_naked
\emph default
function modifier attribute prevents the compiler from generating prologue
- and epilogue code for that function.
+\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
\family typewriter
data unsigned char counter;
\newline
-void simpleInterrupt(void) interrupt 1
+void simpleInterrupt(void) interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ 1
\newline
{
\newline
\layout Subsection
Functions using private banks
+\begin_inset LatexCommand \index{banks}
+
+\end_inset
+
+
\layout Standard
The
\emph on
using
+\begin_inset LatexCommand \index{using}
+
+\end_inset
+
+
\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
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
\emph default
functions (see note 1 below).
This will in most circumstances make the generated ISR code more efficient
\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
+ 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
\layout Subsection
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 <address>
+at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ <address>
\emph default
keyword, in addition to a storage class, e.g.:
\newline
\newline
\family typewriter
-xdata at 0x8000 unsigned char PORTA_8255 ;
+xdata
+\begin_inset LatexCommand \index{xdata}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x8000 unsigned char PORTA_8255 ;
\newline
\family default
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.
+ The assembler listing file (.lst
+\begin_inset LatexCommand \index{.lst}
+
+\end_inset
+
+) and the linker output files (.rst
+\begin_inset LatexCommand \index{.rst}
+
+\end_inset
+
+) and (.map
+\begin_inset LatexCommand \index{.map}
+
+\end_inset
+
+) are a good places to look for such overlaps.
\newline
\newline
\newline
\family typewriter
-bit at 0x02 bvar;
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ 0x02 bvar;
\newline
\newline
\layout Subsection
Startup Code
+\begin_inset LatexCommand \index{Startup Code}
+
+\end_inset
+
+
\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
\layout Subsection
Inline Assembler Code
+\begin_inset LatexCommand \index{Inline Assembler Code}
+
+\end_inset
+
+
\layout Standard
SDCC allows the use of in-line assembler with a few restriction as regards
When the
\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.
+ the peephole optimizer
+\begin_inset LatexCommand \index{Peephole optimizer}
+
+\end_inset
+
+.
This might cause some unexpected changes in the inline assembler code.
Please go throught the peephole optimizer rules defined in file
\emph on
\newline
\family typewriter
-_asm
+_asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
b,00001$
\newline
-_endasm ;
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+ ;
\family default
\size small
\newline
Inline assembler code cannot reference any C-Labels, however it can reference
- labels defined by the inline assembler, e.g.:
+ labels
+\begin_inset LatexCommand \index{Labels}
+
+\end_inset
+
+ defined by the inline assembler, e.g.:
\newline
\newline
labels defines in inline assembly CANNOT be accessed by C statements.
\layout Subsection
-int (16 bit) and long (32 bit) Support
+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,
\emph on
non-reentrant
\emph default
-, interrupt service routines should not do any of the above operations.
+
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{non-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
---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
---int-long-rent
+\begin_inset LatexCommand \index{---int-long-rent}
+
+\end_inset
+
+
\emph default
option.
\layout Subsection
Floating Point Support
+\begin_inset LatexCommand \index{Floating Point Support}
+
+\end_inset
+
+
\layout Standard
SDCC supports IEEE (single precision 4bytes) floating point numbers.The floating
\layout Subsection
MCS51 Memory Models
+\begin_inset LatexCommand \index{Memory Models}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{MCS51 Memory Models}
+
+\end_inset
+
+
\layout Standard
SDCC allows two memory models for MCS51 code, small and large.
in the internal ram.
\layout Standard
-Judicious usage of the processor specific storage classes and the 'reentrant'
- function type will yield much more efficient code, than using the large
- model.
+Judicious usage of the processor specific storage classes
+\begin_inset LatexCommand \index{storage classes}
+
+\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 strongly recommdended that the small model
be used unless absolutely required.
\layout Subsection
DS390 Memory Models
+\begin_inset LatexCommand \index{Memory Models}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{DS390 Memory Models}
+
+\end_inset
+
+
\layout Standard
-The only model supported is Flat 24.
+The only model supported is Flat 24
+\begin_inset LatexCommand \index{Flat 24}
+
+\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
\emph on
tinibios
\emph default
+
+\begin_inset LatexCommand \index{tinibios}
+
+\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
\layout Subsection
Defines Created by the Compiler
+\begin_inset LatexCommand \index{Defines Created by the Compiler}
+
+\end_inset
+
+
\layout Standard
-The compiler creates the following #defines.
+The compiler creates the following #defines
+\begin_inset LatexCommand \index{\#defines}
+
+\end_inset
+
+.
\layout Itemize
-SDCC - this Symbol is always defined.
+SDCC
+\begin_inset LatexCommand \index{SDCC}
+
+\end_inset
+
+ - this Symbol is always defined.
\layout Itemize
-SDCC_mcs51 or SDCC_ds390 or SDCC_z80, etc - depending on the model used
- (e.g.: -mds390)
+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 - depending on the model used (e.g.: -mds390)
\layout Itemize
-__mcs51 or __ds390 or __z80, etc - depending on the model used (e.g.
+__mcs51
+\begin_inset LatexCommand \index{\_\_mcs51}
+
+\end_inset
+
+ or __ds390
+\begin_inset LatexCommand \index{\_\_ds390}
+
+\end_inset
+
+ or __z80
+\begin_inset LatexCommand \index{\_\_z80}
+
+\end_inset
+
+, etc - depending on the model used (e.g.
-mz80)
\layout Itemize
-SDCC_STACK_AUTO - this symbol is defined when
+SDCC_STACK_AUTO
+\begin_inset LatexCommand \index{SDCC\_STACK\_AUTO}
+
+\end_inset
+
+ - this symbol is defined when
\emph on
---stack-auto
\emph default
option is used.
\layout Itemize
-SDCC_MODEL_SMALL - when
+SDCC_MODEL_SMALL
+\begin_inset LatexCommand \index{SDCC\_MODEL\_SMALL}
+
+\end_inset
+
+ - when
\emph on
---model-small
\emph default
is used.
\layout Itemize
-SDCC_MODEL_LARGE - when
+SDCC_MODEL_LARGE
+\begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
+
+\end_inset
+
+ - when
\emph on
---model-large
\emph default
is used.
\layout Itemize
-SDCC_USE_XSTACK - when
+SDCC_USE_XSTACK
+\begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
+
+\end_inset
+
+ - when
\emph on
---xstack
\emph default
option is used.
\layout Itemize
-SDCC_STACK_TENBIT - when
+SDCC_STACK_TENBIT
+\begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
+
+\end_inset
+
+ - when
\emph on
-mds390
\emph default
is used
\layout Itemize
-SDCC_MODEL_FLAT24 - when
+SDCC_MODEL_FLAT24
+\begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
+
+\end_inset
+
+ - when
\emph on
-mds390
\emph default
\layout Subsection
Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
+\end_inset
+
+
\layout Standard
SDCC performs a host of standard optimizations in addition to some MCU specific
\layout Subsubsection
Sub-expression Elimination
+\begin_inset LatexCommand \index{Sub-expression Elimination}
+
+\end_inset
+
+
\layout Standard
The compiler does local and global common subexpression elimination, e.g.:
\layout Subsubsection
Dead-Code Elimination
+\begin_inset LatexCommand \index{Dead-Code Elimination}
+
+\end_inset
+
+
\layout Standard
\layout Subsubsection
Copy-Propagation
+\begin_inset LatexCommand \index{Copy-Propagation}
+
+\end_inset
+
+
\layout Standard
\layout Subsubsection
Loop Optimizations
+\begin_inset LatexCommand \index{Loop Optimizations}
+
+\end_inset
+
+
\layout Standard
Two types of loop optimizations are done by SDCC loop invariant lifting
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.
+ Because of this preference of the register allocator
+\begin_inset LatexCommand \index{Register allocator}
+
+\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 ---noinduction
option) or for a given function only using #pragma\SpecialChar ~
-NOINDUCTION.
+NOINDUCTION
+\begin_inset LatexCommand \index{\#pragma NOINDUCTION}
+
+\end_inset
+
+.
\newline
\newline
\newline
\newline
-Strength Reduction, this optimization substitutes an expression by a cheaper
- expression:
+Strength Reduction
+\begin_inset LatexCommand \index{Strength Reduction}
+
+\end_inset
+
+, this optimization substitutes an expression by a cheaper expression:
\newline
\newline
\newline
\newline
-The more expensive multiplication is changed to a less expensive addition.
+The more expensive multiplication
+\begin_inset LatexCommand \index{multiplication}
+
+\end_inset
+
+ is changed to a less expensive addition.
\layout Subsubsection
Loop Reversing
+\begin_inset LatexCommand \index{Loop Reversing}
+
+\end_inset
+
+
\layout Standard
This optimization is done to reduce the overhead of checking loop boundaries
\newline
\newline
-Note the subexpressions given above are generally introduced by macro expansions
- or as a result of copy/constant propagation.
+Note the subexpressions
+\begin_inset LatexCommand \index{subexpressions}
+
+\end_inset
+
+ given above are generally introduced by macro expansions or as a result
+ of copy/constant propagation.
\layout Subsubsection
'switch' Statements
+\begin_inset LatexCommand \index{switch Statements}
+
+\end_inset
+
+
\layout Standard
-SDCC changes switch statements to jump tables when the following conditions
- are true.
+SDCC changes switch statements to jump tables
+\begin_inset LatexCommand \index{jump tables}
+
+\end_inset
+
+ when the following conditions are true.
\layout Itemize
the unmodified switch statement will not be.
\layout Subsubsection
-Bit-shifting Operations.
+Bit-shifting Operations
+\begin_inset LatexCommand \index{Bit-shifting Operations}
+
+\end_inset
+
+.
\layout Standard
Bit shifting is one of the most frequently used operation in embedded programmin
\layout Subsubsection
Bit-rotation
+\begin_inset LatexCommand \index{Bit-rotation}
+
+\end_inset
+
+
\layout Standard
A special case of the bit-shift operation is bit rotation, SDCC recognizes
\layout Subsubsection
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
will still be recognized.
\layout Subsubsection
-Peep-hole Optimizer
+Peephole Optimizer
+\begin_inset LatexCommand \index{Peephole optimizer}
+
+\end_inset
+
+
\layout Standard
The compiler uses a rule based, pattern matching and re-writing mechanism
A default set of rules are compiled into the compiler, additional rules
may be added with the
\emph on
----peep-file <filename>
+---peep-file
+\begin_inset LatexCommand \index{---peep-file}
+
+\end_inset
+
+ <filename>
\emph default
option.
The rule language is best illustrated with examples.
\layout Subsection
Pragmas
+\begin_inset LatexCommand \index{Pragmas}
+
+\end_inset
+
+
\layout Standard
SDCC supports the following #pragma directives.
\layout Itemize
-SAVE - this will save all current options to the SAVE/RESTORE stack.
+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 - will restore saved options from the last save.
+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 - will stop global subexpression elimination.
+NOGCSE
+\begin_inset LatexCommand \index{\#pragma NOGCSE}
+
+\end_inset
+
+ - will stop global subexpression elimination.
\layout Itemize
-NOINDUCTION - will stop loop induction optimizations.
+NOINDUCTION
+\begin_inset LatexCommand \index{\#pragma NOINDUCTION}
+
+\end_inset
+
+ - will stop loop induction optimizations.
\layout Itemize
-NOJTBOUND - will not generate code for boundary value checking, when switch
- statements are turned into jump-tables.
+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.
\layout Itemize
-NOOVERLAY - the compiler will not overlay the parameters and local variables
- of a function.
+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 - the compiler will not warn you anymore for obvious mistakes,
- you'r on your own now ;-(
+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 - Will not do loop reversal optimization
+NOLOOPREVERSE
+\begin_inset LatexCommand \index{\#pragma NOLOOPREVERSE}
+
+\end_inset
+
+ - Will not do loop reversal optimization
\layout Itemize
-EXCLUDE NONE | {acc[,b[,dpl[,dph]]] - The exclude pragma disables generation
- of pair of push/pop instruction in ISR function (using interrupt keyword).
+EXCLUDE
+\begin_inset LatexCommand \index{\#pragma EXCLUDE}
+
+\end_inset
+
+ 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 ~
none.
\layout Itemize
-NOIV - Do not generate interrupt vector table entries for all ISR functions
+NOIV
+\begin_inset LatexCommand \index{\#pragma NOIV}
+
+\end_inset
+
+ - 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
for the autovector feature of the Cypress EZ-USB FX2).
\layout Itemize
-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.
+CALLEE-SAVES
+\begin_inset LatexCommand \index{\#pragma CALLEE-SAVES}
+
+\end_inset
+
+ 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 off the register saving convention for
the function names specified.
The compiler will not save registers when calling these functions, extra
\newline
\family typewriter
-#pragma SAVE /* save the current settings */
+#pragma SAVE
+\begin_inset LatexCommand \index{\#pragma SAVE}
+
+\end_inset
+
+ /* save the current settings */
\newline
-#pragma NOGCSE /* turnoff global subexpression elimination */
+#pragma NOGCSE
+\begin_inset LatexCommand \index{\#pragma NOGCSE}
+
+\end_inset
+
+ /* turnoff global subexpression elimination */
\newline
-#pragma NOINDUCTION /* turn off induction optimizations */
+#pragma NOINDUCTION
+\begin_inset LatexCommand \index{\#pragma NOINDUCTION}
+
+\end_inset
+
+ /* turn off induction optimizations */
\newline
int foo ()
\newline
\newline
}
\newline
-#pragma RESTORE /* turn the optimizations back on */
+#pragma RESTORE
+\begin_inset LatexCommand \index{\#pragma RESTORE}
+
+\end_inset
+
+ /* turn the optimizations back on */
\family default
\newline
\layout Subsection
Interfacing with Assembly Routines
+\begin_inset LatexCommand \index{Assembly Routines}
+
+\end_inset
+
+
\layout Subsubsection
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,B
+DPL
+\begin_inset LatexCommand \index{DPL}
+
+\end_inset
+
+,DPH
+\begin_inset LatexCommand \index{DPH}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{DPTR}
+
+\end_inset
+
+,B
+\begin_inset LatexCommand \index{B}
+
+\end_inset
+
+
\emph default
and
\emph on
ACC
+\begin_inset LatexCommand \index{ACC}
+
+\end_inset
+
+
\emph default
to pass the first parameter to a routine.
The second parameter onwards is either allocated on the stack (for reentrant
\layout Subsubsection
Assembler Routine(non-reentrant)
+\begin_inset LatexCommand \index{Assembler Routine(non-reentrant)}
+
+\end_inset
+
+
\layout Standard
In the following example the function cfunc calls an assembler routine asm_func,
\layout Subsubsection
Assembler Routine(reentrant)
+\begin_inset LatexCommand \index{Assembler Routine(reentrant)}
+
+\end_inset
+
+
\layout Standard
In this case the second parameter onwards will be passed on the stack, the
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov _bp,sp
+mov _bp,sp
\newline
\SpecialChar ~
\SpecialChar ~
\layout Subsection
External Stack
+\begin_inset LatexCommand \index{External Stack}
+
+\end_inset
+
+
\layout Standard
The external stack is located at the start of the external ram segment,
\layout Subsection
ANSI-Compliance
+\begin_inset LatexCommand \index{ANSI-Compliance}
+
+\end_inset
+
+
\layout Standard
Deviations from the compliancy.
\layout Subsection
Cyclomatic Complexity
+\begin_inset LatexCommand \index{Cyclomatic Complexity}
+
+\end_inset
+
+
\layout Standard
Cyclomatic complexity of a function is defined as the number of independent
compiler will be smart enough to detect such optimization oppurtunities).
\layout Subsection
-Notes on MCS51 memory layout
+Notes on MCS51 memory
+\begin_inset LatexCommand \index{MCS51 memory}
+
+\end_inset
+
+ layout
\layout Standard
The 8051 family of micro controller have a minimum of 128 bytes of internal
\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.
+Normally the SDCC compiler will only utilise the first bank
+\begin_inset LatexCommand \index{bank}
+
+\end_inset
+
+ of registers, 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 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.
+ 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 60 bytes for general purpose use.
\layout Standard
By default, the compiler uses the 60 general purpose bytes to hold "near
\layout Standard
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.
+ to save registers before a subroutine call is made (---stack-auto
+\begin_inset LatexCommand \index{---stack-auto}
+
+\end_inset
+
+ 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
\layout Standard
----stack-loc will allow you specify the start of the stack, i.e.
+---stack-loc
+\begin_inset LatexCommand \index{---stack-loc}
+
+\end_inset
+
+ 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
----stack-after-data, similar to the ---stack-loc, but it automatically places
- the stack after the end of the "near data".
+---stack-after-data
+\begin_inset LatexCommand \index{---stack-after-data}
+
+\end_inset
+
+, 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
----data-loc allows you to specify the start address of the near data.
+---data-loc
+\begin_inset LatexCommand \index{---data-loc}
+
+\end_inset
+
+ 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
As mentioned in the optimization section the peep-hole optimizer is rule
based system, which can reprogrammed for other MCUs.
\layout Section
+\pagebreak_top
+SDCDB
+\begin_inset LatexCommand \index{SDCDB}
+
+\end_inset
+
+ - Source Level Debugger
+\begin_inset LatexCommand \index{Debugger}
+
+\end_inset
+
-SDCDB - Source Level Debugger
\layout Standard
SDCC is distributed with a source level debugger.
My name is Bobby Brown"
\layout Subsection
-Interfacing with XEmacs.
+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,
\newline
\layout Section
-
+\pagebreak_top
Other Processors
\layout Subsection
\layout Section
Support
+\begin_inset LatexCommand \index{Support}
+
+\end_inset
+
+
\layout Standard
SDCC has grown to be a large project.
\layout Subsection
Reporting Bugs
+\begin_inset LatexCommand \index{Bugs}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Reporting Bugs}
+
+\end_inset
+
+
\layout Standard
Send an email to the mailing list at 'user-sdcc@sdcc.sourceforge.net' or 'devel-sd
Compiling your program with the ---dumpall option can sometimes be useful
in locating optimization problems.
\layout Section
-
+\pagebreak_top
Compiler internals
\layout Subsection
\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
\layout Paragraph*
ICode Example
+\begin_inset LatexCommand \index{ICode Example}
+
+\end_inset
+
+
\layout Standard
This section shows some details of iCode.
All product names mentioned herein may be trademarks 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 / commitdiff