Provided by: sdcc_4.2.0+dfsg-1_amd64 
NAME
sdcc - Small Device C Compiler
SYNOPSIS
sdcc [options] filename
WARNING
The information in this man page is an extract from the full documentation of SDCC, and is limited to the
meaning of the options.
For complete and current documentation, refer to the SDCC Compiler User Guide.
DESCRIPTION
SDCC is free open source, retargettable, optimizing ANSI-C compiler designed for 8 bit Microprocessors.
The current version targets Intel MCS51 based Microprocessors (8031, 8032, 8051, 8052, etc.), Dallas
DS80C390 variants, Freescale (formerly Motorola) HC08 and Zilog Z80 based MCUs (z80, z180, gbz80, Rabbit
2000/3000). It can be retargeted for other microprocessors, support for Microchip PIC is under
development.
SDCC uses a modified version of ASXXXX & ASLINK, free open source retargetable assembler & linker.
SDCC has extensive language extensions suitable for utilizing various microcontrollers and underlying
hardware effectively.
SDCC uses ASXXXX & ASLINK, a Freeware, retargettable assembler & linker. SDCC has extensive language
extensions suitable for utilizing various microcontrollers and underlying hardware effectively.
The compiler also allows inline assembler code to be embedded anywhere in a function. In addition,
routines developed in assembly can also be called.
PROCESSOR SELECTION OPTIONS
-mmcs51
Generate code for the MCS51 (8051) family of processors. This is the default processor target.
-mds390
Generate code for the DS80C390 processor.
-mds400
Generate code for the DS80C400 processor.
-mz80 Generate code for the Z80 family of processors.
-mhc08 Generate code for the GameBoy Z80 processor.
-mz80 Generate code for the Zilog Z80 family of processors.
-mz180 Generate code for the Zilog Z180 family of processors.
-mr2k Generate code for the Rabbit 2000 / Rabbit 3000 family of processors."
-mr3ka Generate code for the Rabbit 2000 / Rabbit 3000 family of processors. Check XXXXX"
-mgbz80
Generate code for the GameBoy Z80 processor (Not actively maintained).
-mpic14
Generate code for the Microchip PIC 14-bit processors (p16f84 and variants. In development, not
complete).
-mpic16
Generate code for the Microchip PIC 16-bit processors (p18f452 and variants. In development, not
complete).
-mtlcs900h
Generate code for the Toshiba TLCS-900H processor (Not maintained, not complete).
-mxa51 Generate code for the Phillips XA51 processor (Not maintained, not complete).
-mstm8 Generate code for the STM8 processor.
PREPROCESSOR OPTIONS
-I<path>
The additional location where the pre processor will look for `<..h>' or `..h' files.
-D <macro[=value]>
Command line definition of macros. Passed to the pre processor.
-M Tell the preprocessor to output a rule suitable for make describing the dependencies of each
object file. For each source file, the preprocessor outputs one make-rule whose target is the
object file name for that source file and whose dependencies are all the files `#include'd in it.
This rule may be a single line or may be continued with `\'-newline if it is long. The list of
rules is printed on standard output instead of the preprocessed C program. `-M' implies `-E'.
-C Tell the preprocessor not to discard comments. Used with the `-E' option.
-MM Like `-M' but the output mentions only the user header files included with `#include "file"'.
System header files included with `#include <file>' are omitted.
-A question(answer)
Assert the answer answer for question, in case it is tested with a preprocessor conditional such
as `#if #question(answer)'. `-A-' disables the standard assertions that normally describe the
target machine.
-A question
(answer) Assert the answer answer for question, in case it is tested with a preprocessor
conditional such as `#if #question(answer)'. `-A-' disables the standard assertions that normally
describe the target machine.
-Umacro
Undefine macro macro. `-U' options are evaluated after all `-D' options, but before any
`-include' and `-imacros' options.
-dM Tell the preprocessor to output only a list of the macro definitions that are in effect at the end
of preprocessing. Used with the '-E' option.
-dD Tell the preprocessor to pass all macro definitions into the output, in their proper sequence in
the rest of the output.
-dN Like `-dD'except that the macro arguments and contents are omitted. Only `#define name' is
included in the output.
LINKER OPTIONS
-L, -lib-path<absolute path to additional libraries>
This option is passed to the linkage editor's additional libraries search path. The path name must
be absolute. Additional library files may be specified in the command line. See section Compiling
programs for more details.
--xram-loc <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.
--code-loc <Value>
The start location of the code segment, default value 0. Note when this option is used the
interrupt vector table is also relocated to the given address. The value entered can be in
Hexadecimal or Decimal format, e.g.: --code-loc 0x8000 or --code-loc 32768.
--stack-loc <Value>
The initial value of the stack pointer. The default value of the stack pointer is 0x07 if only
register bank 0 is used, if other register banks are used then the stack pointer is initialized to
the location above the highest register bank used. eg. if register banks 1 & 2 are used the stack
pointer will default to location 0x18. The value entered can be in Hexadecimal or Decimal format,
eg. --stack-loc 0x20 or --stack-loc 32. If all four register banks are used the stack will be
placed after the data segment (equivalent to --stack-after-data)
--stack-after-data
This option will cause the stack to be located in the internal ram after the data segment.
--data-loc <Value>
The start location of the internal ram data segment, the default value is 0x30. The value entered
can be in Hexadecimal or Decimal format, eg. --data-loc 0x20 or --data-loc 32.
--idata-loc <Value>
The start location of the indirectly addressable internal ram, default value is 0x80. The value
entered can be in Hexadecimal or Decimal format, eg. --idata-loc 0x88 or --idata-loc 136.
--out-fmt-ihx
The linker output (final object code) is in Intel Hex format. (This is the default option).
--out-fmt-s19
The linker output (final object code) is in Motorola S19 format.
MCS51 OPTIONS
--model-large
Generate code for Large model programs see section Memory Models for more details. If this option
is used all source files in the project should be compiled with this option. In addition the
standard library routines are compiled with small model, they will need to be recompiled.
--model-small
Generate code for Small Model programs see section Memory Models for more details. This is the
default model.
DS390 / DS400 OPTIONS
--model-flat24
Generate 24-bit flat mode code. This is the one and only that the ds390 code generator supports
right now and is default when using -mds390.
--protect-sp-update
Disable interrupts during ESP:SP updates.
_--stack-10bit
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 -mds390. In this mode, the
stack is located in the lower 1K of the internal RAM, which is mapped to 0x400000 . Note that the
support is incomplete, since it still uses a single byte as the stack pointer. This means that
only the lower 256 bytes of the potential 1K stack space will actually be used. However, this does
allow you to reclaim the precious 256 bytes of low RAM for use for the DATA and IDATA segments.
The compiler will not generate any code to put the processor into 10 bit stack mode. It is
important to ensure that the processor is in this mode before calling any re-entrant functions
compiled with this option. In principle, this should work with the --stack-auto option, but that
has not been tested. It is incompatible with the --xstack option. It also only makes sense if the
processor is in 24 bit contiguous addressing mode (see the --model-flat24 option).
Z80 Options
--callee-saves-bc
Force a called function to always save BC.
--no-std-crt0
When linking, skip the standard crt0.o object file. You must provide your own crt0.o for your
system when linking.
OPTIMIZATIONS OPTIONS
--nogcse
Will not do global subexpression elimination, this option may be used when the compiler creates
undesirably large stack/data spaces to store compiler temporaries. A warning message will be
generated when this happens and the compiler will indicate the number of extra bytes it allocated.
It recommended that this option NOT be used, #pragma NOGCSE can be used to turn off global
subexpression elimination for a given function only.
--noinvariant
Will not do loop invariant optimizations, this may be turned off for reasons explained for the
previous option. For more details of loop optimizations performed see section Loop Invariants.It
recommended that this option NOT be used, #pragma NOINVARIANT can be used to turn off invariant
optimizations for a given function only.
--noinduction
Will not do loop induction optimizations, see section strength reduction for more details. It is
recommended that this option is NOT used, #pragma NOINDUCTION can be used to turn off induction
optimizations for a given function only.
--nojtbound
Will not generate boundary condition check when switch statements are implemented using jump-
tables. It is recommended that this option is NOT used, #pragma NOJTBOUND can be used to turn off
boundary checking for jump tables for a given function only.
--noloopreverse
Will not do loop reversal optimization.
OTHER OPTIONS
-c, --compile-only
will compile and assemble the source, but will not call the linkage editor.
-E Run only the C preprocessor. Preprocess all the C source files specified and output the results to
standard output.
--stack-auto
All functions in the source file will be compiled as reentrant, i.e. the parameters and local
variables will be allocated on the stack. If this option is used all source files in the project
should be compiled with this option.
--xstack
Uses a pseudo stack in the first 256 bytes in the external ram for allocating variables and
passing parameters.
--callee-saves function1[,function2][,function3]....
The compiler by default uses a caller saves convention for register saving across function calls,
however this can cause unnecessary register pushing & popping when calling small functions from
larger functions. This option can be used to switch the register saving convention for the
function names specified. The compiler will not save registers when calling these functions, no
extra code will be generated at the entry & exit for these functions to save & restore the
registers used by these functions, this can SUBSTANTIALLY reduce code & improve run time
performance of the generated code. In the future the compiler (with interprocedural analysis) will
be able to determine the appropriate scheme to use for each function call. DO NOT use this option
for built-in functions such as _muluint..., if this option is used for a library function the
appropriate library function needs to be recompiled with the same option. If the project consists
of multiple source files then all the source file should be compiled with the same --callee-saves
option string.
--debug
When this option is used the compiler will generate debug information, that can be used with the
SDCDB. The debug information is collected in a file with .cdb extension.
--regextend
This option is obsolete and isn't supported anymore.
--noregparms
This option is obsolete and isn't supported anymore.
--peep-file<filename>
This option can be used to use additional rules to be used by the peep hole optimizer.
-S Stop after the stage of compilation proper; do not assemble. The output is an assembler code file
for the input file specified.
-Wa_asmOption[,asmOption]...]
Pass the asmOption to the assembler.
-Wl_linkOption[,linkOption]...]
Pass the linkOption to the linker.
--int-long-reent
Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant. Note by default
these libraries are compiled as non-reentrant.
--cyclomatic
This option will cause the compiler to generate an information message for each function in the
source file. The message contains some important information about the function. The number of
edges and nodes the compiler detected in the control flow graph of the function, and most
importantly the cyclomatic complexity.
--float-reent
Floating point library is compiled as reentrant.
--nooverlay
The compiler will not overlay parameters and local variables of any function, see section
Parameters and local variables for more details.
--main-return
This option can be used when the code generated is called by a monitor program. The compiler will
generate a 'ret' upon return from the 'main' function. The default option is to lock up i.e.
generate a 'ljmp '.
--no-peep
Disable peep-hole optimization.
--peep-asm
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.
--iram-size <Value>
Causes the linker to check if the internal ram usage is within limits of the given value.
--nostdincl
This will prevent the compiler from passing on the default include path to the preprocessor.
--nostdlib
This will prevent the compiler from passing on the default library path to the linker.
--verbose
Shows the various actions the compiler is performing.
-V Shows the actual commands the compiler is executing.
INTERMEDIATE DUMP OPTIONS
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.
--dumpraw
This option will cause the compiler to dump the intermediate code into a file of named <source
filename>. dumpraw 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.
--dumpgcse
Will create a dump of iCode's, after global subexpression elimination, into a file named <source
filename>.dumpgcse.
--dumpdeadcode
Will create a dump of iCode's, after deadcode elimination, into a file named <source
filename>.dumpdeadcode.
--dumploop
Will create a dump of iCode's, after loop optimizations, into a file named <source
filename>.dumploop.
--dumprange
Will create a dump of iCode's, after live range analysis, into a file named <source
filename>.dumprange.
--dumlrange
Will dump the life ranges for all symbols.
--dumpregassign
Will create a dump of iCode's, after register assignment, into a file named <source
filename>.dumprassgn.
--dumplrange
Will create a dump of the live ranges of iTemp's
--dumpall
Will cause all the above mentioned dumps to be created.
COPYING
The entire source code for the compiler is distributed under GNU General Public License.
SEE ALSO
sdcpp(1), asxxxx(1), aslink(1).
AUTHOR
This manual page was written by Aurelien Jarno <aurel32@debian.org>, for the Debian GNU/Linux system (but
may be used by others).
SDCC(1)