AS - the portable GNU assembler.
SYNOPSIS
as [ -a[cdhlns][=file] ] [ -D ] [ --defsym sym=val ]
[ -f ] [ --gstabs ] [ --gdwarf2 ] [ --help ] [ -I dir ]
[ -J ] [ -K ] [ -L ]
[ --listing--lhs-width=NUM ][ --listing-lhs-width2=NUM ]
[ --listing-rhs-width=NUM ][ --listing-cont-lines=NUM ]
[ --keep-locals ] [ -o objfile ] [ -R ] [ --statistics ]
[ -v ]
[ -version ] [ --version ] [ -W ] [ --warn ] [ --fatal-
warnings ]
[ -w ] [ -x ] [ -Z ] [ --target-help ]
[ -marc[5|6|7|8] ]
[ -EB | -EL ]
[ -m[arm]1 | -m[arm]2 | -m[arm]250 | -m[arm]3 |
-m[arm]6 | -m[arm]60 | -m[arm]600 | -m[arm]610 |
-m[arm]620 | -m[arm]7[t][[d]m[i]][fe] | -m[arm]70 |
-m[arm]700 | -m[arm]710[c] | -m[arm]7100 |
-m[arm]7500 | -m[arm]8 | -m[arm]810 | -m[arm]9 |
-m[arm]920 | -m[arm]920t | -m[arm]9tdmi |
-mstrongarm | -mstrongarm110 | -mstrongarm1100 ]
[ -m[arm]v2 | -m[arm]v2a | -m[arm]v3 | -m[arm]v3m |
-m[arm]v4 | -m[arm]v4t | -m[arm]v5 | -[arm]v5t |
-[arm]v5te ]
[ -mthumb | -mall ]
[ -mfpa10 | -mfpa11 | -mfpe-old | -mno-fpu ]
[ -EB | -EL ]
[ -mapcs-32 | -mapcs-26 | -mapcs-float |
-mapcs-reentrant ]
[ -mthumb-interwork ] [ -moabi ] [ -k ]
[ -O ]
[ -O | -n | -N ]
[ -mb | -me ]
[ -Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite
-Av8plus | -Av8plusa | -Av9 | -Av9a ]
[ -xarch=v8plus | -xarch=v8plusa ] [ -bump ]
[ -32 | -64 ]
[ -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB |
-AKC | -AMC ]
[ -b ] [ -no-relax ]
[ --m32rx | --[no-]warn-explicit-parallel-conflicts |
--W[n]p ]
[ -l ] [ -m68000 | -m68010 | -m68020 | ... ]
[ -jsri2bsr ] [ -sifilter ] [ -relax ]
[ -mcpu=[210|340] ]
[ -m68hc11 | -m68hc12 ]
[ --force-long-branchs ] [ --short-branchs ]
[ --strict-direct-mode ] [ --print-insn-syntax ]
[ --print-opcodes ] [ --generate-example ]
[ -nocpp ] [ -EL ] [ -EB ] [ -G num ] [ -mcpu=CPU ]
[ -mips1 ] [ -mips2 ] [ -mips3 ] [ -mips4 ] [ -mips5 ]
[ -mips32 ] [ -mips64 ]
[ --trap ] [ --break ]
[ --emulation=name ]
[ -- | files ... ]
DESCRIPTION
GNU `as' is really a family of assemblers. If you use (or
have used) the GNU assembler on one architecture, you
should find a fairly similar environment when you use it
on another architecture. Each version has much in common
with the others, including object file formats, most
assembler directives (often called pseudo-ops) and assem
bler syntax.
`as' is primarily intended to assemble the output of the
GNU C compiler for use by the linker . Nevertheless,
we've tried to make `as' assemble correctly everything
that other assemblers for the same machine would assemble.
Any exceptions are documented explicitly. This doesn't
mean `as' always uses the same syntax as another assembler
for the same architecture; for example, we know of several
incompatible versions of 680x0 assembly language syntax.
Each time you run `as' it assembles exactly one source
program. The source program is made up of one or more
files. (The standard input is also a file.)
You give `as' a command line that has zero or more input
file names. The input files are read (from left file name
to right). A command line argument (in any position) that
has no special meaning is taken to be an input file name.
If you give `as' no file names it attempts to read one
input file from the `as' standard input, which is normally
your terminal. You may have to type ctl-D to tell `as'
there is no more program to assemble.
Use -- if you need to explicitly name the standard input
file in your command line.
If the source is empty, `as' produces a small, empty
object file.
`as' may write warnings and error messages to the standard
error file (usually your terminal). This should not hap
pen when a compiler runs `as' automatically. Warnings
report an assumption made so that `as' could keep assem
bling a flawed program; errors report a grave problem that
stops the assembly.
If you are invoking `as' via the GNU C compiler (version
2), you can use the -Wa option to pass arguments through
to the assembler. The assembler arguments must be sepa
rated from each other (and the -Wa) by commas. For
gcc -c -g -O -Wa,-alh,-L file.c
This passes two options to the assembler: -alh (emit a
listing to standard output with with high-level and assem
bly source) and -L (retain local symbols in the symbol
table).
Usually you do not need to use this -Wa mechanism, since
many compiler command-line options are automatically
passed to the assembler by the compiler. (You can call
the GNU compiler driver with the -v option to see pre
cisely what options it passes to each compilation pass,
including the assembler.)
OPTIONS
`-a[cdhlmns]'
Turn on listings, in any of a variety of ways:
`-ac'
omit false conditionals
`-ad'
omit debugging directives
`-ah'
include high-level source
`-al'
include assembly
`-am'
include macro expansions
`-an'
omit forms processing
`-as'
include symbols
`=file'
set the name of the listing file
You may combine these options; for example, use -aln
for assembly listing without forms processing. The
=file option, if used, must be the last one. By
itself, -a defaults to -ahls.
`-D'
Ignored. This option is accepted for script compati
bility with calls to other assemblers.
Define the symbol sym to be value before assembling
the input file. value must be an integer constant.
As in C, a leading 0x indicates a hexadecimal value,
and a leading 0 indicates an octal value.
`-f'
``fast''---skip whitespace and comment preprocessing
(assume source is compiler output).
`--gstabs'
Generate stabs debugging information for each assem
bler line. This may help debugging assembler code, if
the debugger can handle it.
`--gdwarf2'
Generate DWARF2 debugging information for each assem
bler line. This may help debugging assembler code, if
the debugger can handle it. Note - this option is
only supported by some targets, not all of them.
`--help'
Print a summary of the command line options and exit.
`--target-help'
Print a summary of all target specific options and
exit.
`-I dir'
Add directory dir to the search list for `.include'
directives.
`-J'
Don't warn about signed overflow.
`-K'
This option is accepted but has no effect on the TAR
GET family.
`-L'
`--keep-locals'
Keep (in the symbol table) local symbols. On tradi
tional a.out systems these start with L, but different
systems have different local label prefixes.
`--listing-lhs-width=number'
Set the maximum width, in words, of the output data
column for an assembler listing to number.
`--listing-lhs-width2=number'
Set the maximum width, in words, of the output data
column for continuation lines in an assembler listing
to number.
Set the maximum width of an input source line, as dis
played in a listing, to number bytes.
`--listing-cont-lines=number'
Set the maximum number of lines printed in a listing
for a single line of input to number + 1.
`-o objfile'
Name the object-file output from `as' objfile.
`-R'
Fold the data section into the text section.
`--statistics'
Print the maximum space (in bytes) and total time (in
seconds) used by assembly.
`--strip-local-absolute'
Remove local absolute symbols from the outgoing symbol
table.
`-v'
`-version'
Print the `as' version.
`--version'
Print the `as' version and exit.
`-W'
`--no-warn'
Suppress warning messages.
`--fatal-warnings'
Treat warnings as errors.
`--warn'
Don't suppress warning messages or treat them as
errors.
`-w'
Ignored.
`-x'
Ignored.
`-Z'
Generate an object file even after errors.
`-- | files ...'
Standard input, or source files to assemble.
for an ARC processor.
`-marc[5|6|7|8]'
This option selects the core processor variant.
`-EB | -EL'
Select either big-endian (-EB) or little-endian (-EL)
output.
The following options are available when as is configured
for the ARM processor family.
`-m[arm][1|2|3|6|7|8|9][...] '
Specify which ARM processor variant is the target.
`-m[arm]v[2|2a|3|3m|4|4t|5|5t]'
Specify which ARM architecture variant is used by the
target.
`-mthumb | -mall'
Enable or disable Thumb only instruction decoding.
`-mfpa10 | -mfpa11 | -mfpe-old | -mno-fpu'
Select which Floating Point architecture is the tar
get.
`-mapcs-32 | -mapcs-26 | -mapcs-float |
-mapcs-reentrant | -moabi'
Select which procedure calling convention is in use.
`-EB | -EL'
Select either big-endian (-EB) or little-endian (-EL)
output.
`-mthumb-interwork'
Specify that the code has been generated with inter
working between Thumb and ARM code in mind.
`-k'
Specify that PIC code has been generated.
The following options are available when as is configured
for a D10V processor.
`-O'
Optimize output by parallelizing instructions.
The following options are available when as is configured
for a D30V processor.
`-O'
Optimize output by parallelizing instructions.
Warn when nops are generated.
`-N'
Warn when a nop after a 32-bit multiply instruction is
generated.
The following options are available when as is configured
for the Intel 80960 processor.
`-ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC'
Specify which variant of the 960 architecture is the
target.
`-b'
Add code to collect statistics about branches taken.
`-no-relax'
Do not alter compare-and-branch instructions for long
displacements; error if necessary.
The following options are available when as is configured
for the Mitsubishi M32R series.
`--m32rx'
Specify which processor in the M32R family is the tar
get. The default is normally the M32R, but this
option changes it to the M32RX.
`--warn-explicit-parallel-conflicts or --Wp'
Produce warning messages when questionable parallel
constructs are encountered.
`--no-warn-explicit-parallel-conflicts or --Wnp'
Do not produce warning messages when questionable par
allel constructs are encountered.
The following options are available when as is configured
for the Motorola 68000 series.
`-l'
Shorten references to undefined symbols, to one word
instead of two.
`-m68000 | -m68008 | -m68010 | -m68020 | -m68030'
`| -m68040 | -m68060 | -m68302 | -m68331 | -m68332'
`| -m68333 | -m68340 | -mcpu32 | -m5200'
Specify what processor in the 68000 family is the tar
get. The default is normally the 68020, but this can
be changed at configuration time.
The target machine does (or does not) have a floating-
point coprocessor. The default is to assume a copro
cessor for 68020, 68030, and cpu32. Although the
basic 68000 is not compatible with the 68881, a combi
nation of the two can be specified, since it's possi
ble to do emulation of the coprocessor instructions
with the main processor.
`-m68851 | -mno-68851'
The target machine does (or does not) have a memory-
management unit coprocessor. The default is to assume
an MMU for 68020 and up.
For details about the PDP-11 machine dependent features
options, see @ref{PDP-11-Options}.
`-mpic | -mno-pic'
Generate position-independent (or position-dependent)
code. The default is `-mpic'.
`-mall'
`-mall-extensions'
Enable all instruction set extensions. This is the
default.
`-mno-extensions'
Disable all instruction set extensions.
`-mextension | -mno-extension'
Enable (or disable) a particular instruction set
extension.
`-mcpu'
Enable the instruction set extensions supported by a
particular CPU, and disable all other extensions.
`-mmachine'
Enable the instruction set extensions supported by a
particular machine model, and disable all other exten
sions.
The following options are available when as is configured
for a picoJava processor.
`-mb'
Generate ``big endian'' format output.
`-ml'
Generate ``little endian'' format output.
The following options are available when as is configured
for the Motorola 68HC11 or 68HC12 series.
Specify what processor is the target. The default is
defined by the configuration option when building the
assembler.
`--force-long-branchs'
Relative branches are turned into absolute ones. This
concerns conditional branches, unconditional branches
and branches to a sub routine.
`-S | --short-branchs'
Do not turn relative branchs into absolute ones when
the offset is out of range.
`--strict-direct-mode'
Do not turn the direct addressing mode into extended
addressing mode when the instruction does not support
direct addressing mode.
`--print-insn-syntax'
Print the syntax of instruction in case of error.
`--print-opcodes'
print the list of instructions with syntax and then
exit.
`--generate-example'
print an example of instruction for each possible
instruction and then exit. This option is only useful
for testing `as'.
The following options are available when `as' is config
ured for the SPARC architecture:
`-Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite'
`-Av8plus | -Av8plusa | -Av9 | -Av9a'
Explicitly select a variant of the SPARC architecture.
-Av8plus and -Av8plusa select a 32 bit environment.
-Av9 and -Av9a select a 64 bit environment.
-Av8plusa and -Av9a enable the SPARC V9 instruction
set with UltraSPARC extensions.
`-xarch=v8plus | -xarch=v8plusa'
For compatibility with the Solaris v9 assembler.
These options are equivalent to -Av8plus and
-Av8plusa, respectively.
`-bump'
Warn when the assembler switches to another architec
ture.
for a MIPS processor.
`-G num'
This option sets the largest size of an object that
can be referenced implicitly with the `gp' register.
It is only accepted for targets that use ECOFF format,
such as a DECstation running Ultrix. The default
value is 8.
`-EB'
Generate ``big endian'' format output.
`-EL'
Generate ``little endian'' format output.
`-mips1'
`-mips2'
`-mips3'
`-mips4'
`-mips32'
Generate code for a particular MIPS Instruction Set
Architecture level. -mips1 corresponds to the R2000
and R3000 processors, -mips2 to the R6000 processor,
and -mips3 to the R4000 processor. -mips5, -mips32,
and -mips64 correspond to generic MIPS V, MIPS32, and
MIPS64 ISA processors, respectively.
`-m4650'
`-no-m4650'
Generate code for the MIPS R4650 chip. This tells the
assembler to accept the mad and madu instruction, and
to not schedule nop instructions around accesses to
the HI and LO registers. -no-m4650 turns off this
option.
`-mcpu=PU'
Generate code for a particular MIPS cpu. It is
exactly equivalent to -mcpu, except that there are
more value of cpu understood.
`--emulation=name'
This option causes `as' to emulate `as' configured for
some other target, in all respects, including output
format (choosing between ELF and ECOFF only), handling
of pseudo-opcodes which may generate debugging infor
mation or store symbol table information, and default
endianness. The available configuration names are:
mipsecoff, mipself, mipslecoff, mipsbecoff, mipslelf,
endianness from that of the primary target for which
the assembler was configured; the others change the
default to little- or big-endian as indicated by the b
or l in the name. Using -EB or -EL will override the
endianness selection in any case.
This option is currently supported only when the pri
mary target `as' is configured for is a MIPS ELF or
ECOFF target. Furthermore, the primary target or oth
ers specified with --enable-targets=... at configura
tion time must include support for the other format,
if both are to be available. For example, the Irix 5
configuration includes support for both.
Eventually, this option will support more configura
tions, with more fine-grained control over the assem
bler's behavior, and will be supported for more pro
cessors.
`-nocpp'
`as' ignores this option. It is accepted for compati
bility with the native tools.
`--trap'
`--no-trap'
`--break'
`--no-break'
Control how to deal with multiplication overflow and
division by zero. --trap or --no-break (which are
synonyms) take a trap exception (and only work for
Instruction Set Architecture level 2 and higher);
--break or --no-trap (also synonyms, and the default)
take a break exception.
The following options are available when as is configured
for an MCore processor.
`-jsri2bsr'
`-nojsri2bsr'
Enable or disable the JSRI to BSR transformation. By
default this is enabled. The command line option
-nojsri2bsr can be used to disable it.
`-sifilter'
`-nosifilter'
Enable or disable the silicon filter behaviour. By
default this is disabled. The default can be overrid
den by the -sifilter command line option.
Alter jump instructions for long displacements.
`-mcpu=[210|340]'
Select the cpu type on the target hardware. This con
trols which instructions can be assembled.
`-EB'
Assemble for a big endian target.
`-EL'
Assemble for a little endian target.
SEE ALSO
gcc(1), ld(1), and the Info entries for binutils and ld.
COPYRIGHT
Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
2001 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify
this document under the terms of the GNU Free Documenta
tion License, Version 1.1 or any later version published
by the Free Software Foundation; with no Invariant Sec
tions, with no Front-Cover Texts, and with no Back-Cover
Texts. A copy of the license is included in the section
entitled "GNU Free Documentation License".
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