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 a Freeware, retargettable, optimizing ANSI-C compiler. The
current version targets Intel MCS51 based Microprocessors(8051, 8052,
etc), Zilog Z80 based MCUs, and the Dallas DS80C390 variant. It can be
retargetted for other microprocessors, support for PIC, AVR and 186 is
under development.
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.
-mgbz80
Generate code for the GameBoy Z80 processor.
-mavr Generate code for the Atmel AVR processor (In development, not
complete).
-mpic14
Generate code for the PIC 14-bit processors (In development, not
complete).
-mpic16
Generate code for the PIC 14-bit processors (In development, not
complete).
-mtlcs900h
Generate code for the Toshiba TLCS-900H processor (In
development, not complete). -mxa51 Generate code for the
Phillips XA51 processor (In development, not complete).
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
unneccessary register pushing & popping when calling small
functions from larger functions. This option can be used to
switch the register saving convention for the function names
specified. The compiler will not save registers when calling
these functions, no extra code will be generated at the entry &
exit for these functions to save & restore the registers used by
these functions, this can SUBSTANTIALLY reduce code & improve
run time performance of the generated code. In the future the
compiler (with interprocedural analysis) will be able to
determine the appropriate scheme to use for each function call.
DO NOT use this option for built-in functions such as
_muluint..., if this option is used for a library function the
appropriate library function needs to be recompiled with the
same option. If the project consists of multiple source files
then all the source file should be compiled with the same
--callee-saves option string.
--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 interal 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).