1AS(1) GNU Development Tools AS(1)
2
6 AS - the portable GNU assembler.
7
9 as [-a[cdghlns][=file]] [--alternate] [-D]
10 [--debug-prefix-map old=new]
11 [--defsym sym=val] [-f] [-g] [--gstabs]
12 [--gstabs+] [--gdwarf-2] [--help] [-I dir] [-J]
13 [-K] [-L] [--listing-lhs-width=NUM]
14 [--listing-lhs-width2=NUM] [--listing-rhs-width=NUM]
15 [--listing-cont-lines=NUM] [--keep-locals] [-o
16 objfile] [-R] [--reduce-memory-overheads] [--statistics]
17 [-v] [-version] [--version] [-W] [--warn]
18 [--fatal-warnings] [-w] [-x] [-Z] [@FILE]
19 [--target-help] [target-options]
20 [--⎪files ...]
21 Target Alpha options:
23 [-mcpu]
24 [-mdebug ⎪ -no-mdebug]
25 [-relax] [-g] [-Gsize]
26 [-F] [-32addr]
27 Target ARC options:
29 [-marc[5⎪6⎪7⎪8]]
30 [-EB⎪-EL]
31 Target ARM options:
33 [-mcpu=processor[+extension...]]
34 [-march=architecture[+extension...]]
35 [-mfpu=floating-point-format]
36 [-mfloat-abi=abi]
37 [-meabi=ver]
38 [-mthumb]
39 [-EB⎪-EL]
40 [-mapcs-32⎪-mapcs-26⎪-mapcs-float⎪
41 -mapcs-reentrant]
42 [-mthumb-interwork] [-k]
43 Target CRIS options:
45 [--underscore ⎪ --no-underscore]
46 [--pic] [-N]
47 [--emulation=criself ⎪ --emulation=crisaout]
48 [--march=v0_v10 ⎪ --march=v10 ⎪ --march=v32 ⎪ --march=com‐
49 mon_v10_v32]
50 Target D10V options:
52 [-O]
53 Target D30V options:
55 [-O⎪-n⎪-N]
56 Target H8/300 options:
58 [-h-tick-hex]
59 Target i386 options:
61 [--32⎪--64] [-n]
62 [-march=CPU[+EXTENSION...]] [-mtune=CPU]
63 Target i960 options:
65 [-ACA⎪-ACA_A⎪-ACB⎪-ACC⎪-AKA⎪-AKB⎪
66 -AKC⎪-AMC]
67 [-b] [-no-relax]
68 Target IA-64 options:
70 [-mconstant-gp⎪-mauto-pic]
71 [-milp32⎪-milp64⎪-mlp64⎪-mp64]
72 [-mle⎪mbe]
73 [-mtune=itanium1⎪-mtune=itanium2]
74 [-munwind-check=warning⎪-munwind-check=error]
75 [-mhint.b=ok⎪-mhint.b=warning⎪-mhint.b=error]
76 [-x⎪-xexplicit] [-xauto] [-xdebug]
77 Target IP2K options:
79 [-mip2022⎪-mip2022ext]
80 Target M32C options:
82 [-m32c⎪-m16c] [-relax] [-h-tick-hex]
83 Target M32R options:
85 [--m32rx⎪--[no-]warn-explicit-parallel-conflicts⎪
86 --W[n]p]
87 Target M680X0 options:
89 [-l] [-m68000⎪-m68010⎪-m68020⎪...]
90 Target M68HC11 options:
92 [-m68hc11⎪-m68hc12⎪-m68hcs12]
93 [-mshort⎪-mlong]
94 [-mshort-double⎪-mlong-double]
95 [--force-long-branches] [--short-branches]
96 [--strict-direct-mode] [--print-insn-syntax]
97 [--print-opcodes] [--generate-example]
98 Target MCORE options:
100 [-jsri2bsr] [-sifilter] [-relax]
101 [-mcpu=[210⎪340]]
102 Target MIPS options:
104 [-nocpp] [-EL] [-EB] [-O[optimization level]]
105 [-g[debug level]] [-G num] [-KPIC] [-call_shared]
106 [-non_shared] [-xgot [-mvxworks-pic]
107 [-mabi=ABI] [-32] [-n32] [-64] [-mfp32] [-mgp32]
108 [-march=CPU] [-mtune=CPU] [-mips1] [-mips2]
109 [-mips3] [-mips4] [-mips5] [-mips32] [-mips32r2]
110 [-mips64] [-mips64r2]
111 [-construct-floats] [-no-construct-floats]
112 [-trap] [-no-break] [-break] [-no-trap]
113 [-mfix7000] [-mno-fix7000]
114 [-mips16] [-no-mips16]
115 [-msmartmips] [-mno-smartmips]
116 [-mips3d] [-no-mips3d]
117 [-mdmx] [-no-mdmx]
118 [-mdsp] [-mno-dsp]
119 [-mdspr2] [-mno-dspr2]
120 [-mmt] [-mno-mt]
121 [-mdebug] [-no-mdebug]
122 [-mpdr] [-mno-pdr]
123 Target MMIX options:
125 [--fixed-special-register-names] [--globalize-symbols]
126 [--gnu-syntax] [--relax] [--no-predefined-symbols]
127 [--no-expand] [--no-merge-gregs] [-x]
128 [--linker-allocated-gregs]
129 Target PDP11 options:
131 [-mpic⎪-mno-pic] [-mall] [-mno-extensions]
132 [-mextension⎪-mno-extension]
133 [-mcpu] [-mmachine]
134 Target picoJava options:
136 [-mb⎪-me]
137 Target PowerPC options:
139 [-mpwrx⎪-mpwr2⎪-mpwr⎪-m601⎪-mppc⎪-mppc32⎪-m603⎪-m604⎪
140 -m403⎪-m405⎪-mppc64⎪-m620⎪-mppc64bridge⎪-mbooke⎪
141 -mbooke32⎪-mbooke64]
142 [-mcom⎪-many⎪-maltivec⎪-mvsx] [-memb]
143 [-mregnames⎪-mno-regnames]
144 [-mrelocatable⎪-mrelocatable-lib]
145 [-mlittle⎪-mlittle-endian⎪-mbig⎪-mbig-endian]
146 [-msolaris⎪-mno-solaris]
147 Target SPARC options:
149 [-Av6⎪-Av7⎪-Av8⎪-Asparclet⎪-Asparclite
150 -Av8plus⎪-Av8plusa⎪-Av9⎪-Av9a]
151 [-xarch=v8plus⎪-xarch=v8plusa] [-bump]
152 [-32⎪-64]
153 Target TIC54X options:
155 [-mcpu=54[123589]⎪-mcpu=54[56]lp] [-mfar-mode⎪-mf]
156 [-merrors-to-file <filename>⎪-me <filename>]
157 Target Z80 options:
159 [-z80] [-r800]
160 [ -ignore-undocumented-instructions] [-Wnud]
161 [ -ignore-unportable-instructions] [-Wnup]
162 [ -warn-undocumented-instructions] [-Wud]
163 [ -warn-unportable-instructions] [-Wup]
164 [ -forbid-undocumented-instructions] [-Fud]
165 [ -forbid-unportable-instructions] [-Fup]
166 Target Xtensa options:
168 [--[no-]text-section-literals] [--[no-]absolute-literals]
169 [--[no-]target-align] [--[no-]longcalls]
170 [--[no-]transform]
171 [--rename-section oldname=newname]
172
174 GNU as is really a family of assemblers. If you use (or have used) the
175 GNU assembler on one architecture, you should find a fairly similar
176 environment when you use it on another architecture. Each version has
177 much in common with the others, including object file formats, most
178 assembler directives (often called pseudo-ops) and assembler syntax.
179 as is primarily intended to assemble the output of the GNU C compiler
181 "gcc" for use by the linker "ld". Nevertheless, we've tried to make as
182 assemble correctly everything that other assemblers for the same
183 machine would assemble. Any exceptions are documented explicitly.
184 This doesn't mean as always uses the same syntax as another assembler
185 for the same architecture; for example, we know of several incompatible
186 versions of 680x0 assembly language syntax.
187 Each time you run as it assembles exactly one source program. The
189 source program is made up of one or more files. (The standard input is
190 also a file.)
191 You give as a command line that has zero or more input file names. The
193 input files are read (from left file name to right). A command line
194 argument (in any position) that has no special meaning is taken to be
195 an input file name.
196 If you give as no file names it attempts to read one input file from
198 the as standard input, which is normally your terminal. You may have
199 to type ctl-D to tell as there is no more program to assemble.
200 Use -- if you need to explicitly name the standard input file in your
202 command line.
203 If the source is empty, as produces a small, empty object file.
205 as may write warnings and error messages to the standard error file
207 (usually your terminal). This should not happen when a compiler runs
208 as automatically. Warnings report an assumption made so that as could
209 keep assembling a flawed program; errors report a grave problem that
210 stops the assembly.
211 If you are invoking as via the GNU C compiler, you can use the -Wa
213 option to pass arguments through to the assembler. The assembler argu‐
214 ments must be separated from each other (and the -Wa) by commas. For
215 example:
216 gcc -c -g -O -Wa,-alh,-L file.c
218 This passes two options to the assembler: -alh (emit a listing to stan‐
220 dard output with high-level and assembly source) and -L (retain local
221 symbols in the symbol table).
222 Usually you do not need to use this -Wa mechanism, since many compiler
224 command-line options are automatically passed to the assembler by the
225 compiler. (You can call the GNU compiler driver with the -v option to
226 see precisely what options it passes to each compilation pass, includ‐
227 ing the assembler.)
228
230 @file
231 Read command-line options from file. The options read are inserted
232 in place of the original @file option. If file does not exist, or
233 cannot be read, then the option will be treated literally, and not
234 removed.
235 Options in file are separated by whitespace. A whitespace charac‐
237 ter may be included in an option by surrounding the entire option
238 in either single or double quotes. Any character (including a
239 backslash) may be included by prefixing the character to be
240 included with a backslash. The file may itself contain additional
241 @file options; any such options will be processed recursively.
242 -a[cdghlmns]
244 Turn on listings, in any of a variety of ways:
245 -ac omit false conditionals
247 -ad omit debugging directives
249 -ag include general information, like as version and options passed
251 -ah include high-level source
253 -al include assembly
255 -am include macro expansions
257 -an omit forms processing
259 -as include symbols
261 =file
263 set the name of the listing file
264 You may combine these options; for example, use -aln for assembly
266 listing without forms processing. The =file option, if used, must
267 be the last one. By itself, -a defaults to -ahls.
268 --alternate
270 Begin in alternate macro mode.
271 -D Ignored. This option is accepted for script compatibility with
273 calls to other assemblers.
274 --debug-prefix-map old=new
276 When assembling files in directory old, record debugging informa‐
277 tion describing them as in new instead.
278 --defsym sym=value
280 Define the symbol sym to be value before assembling the input file.
281 value must be an integer constant. As in C, a leading 0x indicates
282 a hexadecimal value, and a leading 0 indicates an octal value. The
283 value of the symbol can be overridden inside a source file via the
284 use of a ".set" pseudo-op.
285 -f "fast"---skip whitespace and comment preprocessing (assume source
287 is compiler output).
288 -g
290 --gen-debug
291 Generate debugging information for each assembler source line using
292 whichever debug format is preferred by the target. This currently
293 means either STABS, ECOFF or DWARF2.
294 --gstabs
296 Generate stabs debugging information for each assembler line. This
297 may help debugging assembler code, if the debugger can handle it.
298 --gstabs+
300 Generate stabs debugging information for each assembler line, with
301 GNU extensions that probably only gdb can handle, and that could
302 make other debuggers crash or refuse to read your program. This
303 may help debugging assembler code. Currently the only GNU exten‐
304 sion is the location of the current working directory at assembling
305 time.
306 --gdwarf-2
308 Generate DWARF2 debugging information for each assembler line.
309 This may help debugging assembler code, if the debugger can handle
310 it. Note---this option is only supported by some targets, not all
311 of them.
312 --help
314 Print a summary of the command line options and exit.
315 --target-help
317 Print a summary of all target specific options and exit.
318 -I dir
320 Add directory dir to the search list for ".include" directives.
321 -J Don't warn about signed overflow.
323 -K Issue warnings when difference tables altered for long displace‐
325 ments.
326 -L
328 --keep-locals
329 Keep (in the symbol table) local symbols. These symbols start with
330 system-specific local label prefixes, typically .L for ELF systems
331 or L for traditional a.out systems.
332 --listing-lhs-width=number
334 Set the maximum width, in words, of the output data column for an
335 assembler listing to number.
336 --listing-lhs-width2=number
338 Set the maximum width, in words, of the output data column for con‐
339 tinuation lines in an assembler listing to number.
340 --listing-rhs-width=number
342 Set the maximum width of an input source line, as displayed in a
343 listing, to number bytes.
344 --listing-cont-lines=number
346 Set the maximum number of lines printed in a listing for a single
347 line of input to number + 1.
348 -o objfile
350 Name the object-file output from as objfile.
351 -R Fold the data section into the text section.
353 Set the default size of GAS's hash tables to a prime number close
355 to number. Increasing this value can reduce the length of time it
356 takes the assembler to perform its tasks, at the expense of
357 increasing the assembler's memory requirements. Similarly reducing
358 this value can reduce the memory requirements at the expense of
359 speed.
360 --reduce-memory-overheads
362 This option reduces GAS's memory requirements, at the expense of
363 making the assembly processes slower. Currently this switch is a
364 synonym for --hash-size=4051, but in the future it may have other
365 effects as well.
366 --statistics
368 Print the maximum space (in bytes) and total time (in seconds) used
369 by assembly.
370 --strip-local-absolute
372 Remove local absolute symbols from the outgoing symbol table.
373 -v
375 -version
376 Print the as version.
377 --version
379 Print the as version and exit.
380 -W
382 --no-warn
383 Suppress warning messages.
384 --fatal-warnings
386 Treat warnings as errors.
387 --warn
389 Don't suppress warning messages or treat them as errors.
390 -w Ignored.
392 -x Ignored.
394 -Z Generate an object file even after errors.
396 -- ⎪ files ...
398 Standard input, or source files to assemble.
399 The following options are available when as is configured for an ARC
401 processor.
402 -marc[5⎪6⎪7⎪8]
404 This option selects the core processor variant.
405 -EB ⎪ -EL
407 Select either big-endian (-EB) or little-endian (-EL) output.
408 The following options are available when as is configured for the ARM
410 processor family.
411 -mcpu=processor[+extension...]
413 Specify which ARM processor variant is the target.
414 -march=architecture[+extension...]
416 Specify which ARM architecture variant is used by the target.
417 -mfpu=floating-point-format
419 Select which Floating Point architecture is the target.
420 -mfloat-abi=abi
422 Select which floating point ABI is in use.
423 -mthumb
425 Enable Thumb only instruction decoding.
426 -mapcs-32 ⎪ -mapcs-26 ⎪ -mapcs-float ⎪ -mapcs-reentrant
428 Select which procedure calling convention is in use.
429 -EB ⎪ -EL
431 Select either big-endian (-EB) or little-endian (-EL) output.
432 -mthumb-interwork
434 Specify that the code has been generated with interworking between
435 Thumb and ARM code in mind.
436 -k Specify that PIC code has been generated.
438 See the info pages for documentation of the CRIS-specific options.
440 The following options are available when as is configured for a D10V
442 processor.
443 -O Optimize output by parallelizing instructions.
445 The following options are available when as is configured for a D30V
447 processor.
448 -O Optimize output by parallelizing instructions.
450 -n Warn when nops are generated.
452 -N Warn when a nop after a 32-bit multiply instruction is generated.
454 The following options are available when as is configured for the Intel
456 80960 processor.
457 -ACA ⎪ -ACA_A ⎪ -ACB ⎪ -ACC ⎪ -AKA ⎪ -AKB ⎪ -AKC ⎪ -AMC
459 Specify which variant of the 960 architecture is the target.
460 -b Add code to collect statistics about branches taken.
462 -no-relax
464 Do not alter compare-and-branch instructions for long displace‐
465 ments; error if necessary.
466 The following options are available when as is configured for the Ubi‐
468 com IP2K series.
469 -mip2022ext
471 Specifies that the extended IP2022 instructions are allowed.
472 -mip2022
474 Restores the default behaviour, which restricts the permitted
475 instructions to just the basic IP2022 ones.
476 The following options are available when as is configured for the Rene‐
478 sas M32C and M16C processors.
479 -m32c
481 Assemble M32C instructions.
482 -m16c
484 Assemble M16C instructions (the default).
485 -relax
487 Enable support for link-time relaxations.
488 -h-tick-hex
490 Support H'00 style hex constants in addition to 0x00 style.
491 The following options are available when as is configured for the Rene‐
493 sas M32R (formerly Mitsubishi M32R) series.
494 --m32rx
496 Specify which processor in the M32R family is the target. The
497 default is normally the M32R, but this option changes it to the
498 M32RX.
499 --warn-explicit-parallel-conflicts or --Wp
501 Produce warning messages when questionable parallel constructs are
502 encountered.
503 --no-warn-explicit-parallel-conflicts or --Wnp
505 Do not produce warning messages when questionable parallel con‐
506 structs are encountered.
507 The following options are available when as is configured for the
509 Motorola 68000 series.
510 -l Shorten references to undefined symbols, to one word instead of
512 two.
513 -m68000 ⎪ -m68008 ⎪ -m68010 ⎪ -m68020 ⎪ -m68030
515 ⎪ -m68040 ⎪ -m68060 ⎪ -m68302 ⎪ -m68331 ⎪ -m68332
516 ⎪ -m68333 ⎪ -m68340 ⎪ -mcpu32 ⎪ -m5200
517 Specify what processor in the 68000 family is the target. The
518 default is normally the 68020, but this can be changed at configu‐
519 ration time.
520 -m68881 ⎪ -m68882 ⎪ -mno-68881 ⎪ -mno-68882
522 The target machine does (or does not) have a floating-point copro‐
523 cessor. The default is to assume a coprocessor for 68020, 68030,
524 and cpu32. Although the basic 68000 is not compatible with the
525 68881, a combination of the two can be specified, since it's possi‐
526 ble to do emulation of the coprocessor instructions with the main
527 processor.
528 -m68851 ⎪ -mno-68851
530 The target machine does (or does not) have a memory-management unit
531 coprocessor. The default is to assume an MMU for 68020 and up.
532 For details about the PDP-11 machine dependent features options, see
534 PDP-11-Options.
535 -mpic ⎪ -mno-pic
537 Generate position-independent (or position-dependent) code. The
538 default is -mpic.
539 -mall
541 -mall-extensions
542 Enable all instruction set extensions. This is the default.
543 -mno-extensions
545 Disable all instruction set extensions.
546 -mextension ⎪ -mno-extension
548 Enable (or disable) a particular instruction set extension.
549 -mcpu
551 Enable the instruction set extensions supported by a particular
552 CPU, and disable all other extensions.
553 -mmachine
555 Enable the instruction set extensions supported by a particular
556 machine model, and disable all other extensions.
557 The following options are available when as is configured for a pico‐
559 Java processor.
560 -mb Generate "big endian" format output.
562 -ml Generate "little endian" format output.
564 The following options are available when as is configured for the
566 Motorola 68HC11 or 68HC12 series.
567 -m68hc11 ⎪ -m68hc12 ⎪ -m68hcs12
569 Specify what processor is the target. The default is defined by
570 the configuration option when building the assembler.
571 -mshort
573 Specify to use the 16-bit integer ABI.
574 -mlong
576 Specify to use the 32-bit integer ABI.
577 -mshort-double
579 Specify to use the 32-bit double ABI.
580 -mlong-double
582 Specify to use the 64-bit double ABI.
583 --force-long-branches
585 Relative branches are turned into absolute ones. This concerns con‐
586 ditional branches, unconditional branches and branches to a sub
587 routine.
588 -S ⎪ --short-branches
590 Do not turn relative branches into absolute ones when the offset is
591 out of range.
592 --strict-direct-mode
594 Do not turn the direct addressing mode into extended addressing
595 mode when the instruction does not support direct addressing mode.
596 --print-insn-syntax
598 Print the syntax of instruction in case of error.
599 --print-opcodes
601 print the list of instructions with syntax and then exit.
602 --generate-example
604 print an example of instruction for each possible instruction and
605 then exit. This option is only useful for testing as.
606 The following options are available when as is configured for the SPARC
608 architecture:
609 -Av6 ⎪ -Av7 ⎪ -Av8 ⎪ -Asparclet ⎪ -Asparclite
611 -Av8plus ⎪ -Av8plusa ⎪ -Av9 ⎪ -Av9a
612 Explicitly select a variant of the SPARC architecture.
613 -Av8plus and -Av8plusa select a 32 bit environment. -Av9 and -Av9a
615 select a 64 bit environment.
616 -Av8plusa and -Av9a enable the SPARC V9 instruction set with Ultra‐
618 SPARC extensions.
619 -xarch=v8plus ⎪ -xarch=v8plusa
621 For compatibility with the Solaris v9 assembler. These options are
622 equivalent to -Av8plus and -Av8plusa, respectively.
623 -bump
625 Warn when the assembler switches to another architecture.
626 The following options are available when as is configured for the 'c54x
628 architecture.
629 -mfar-mode
631 Enable extended addressing mode. All addresses and relocations
632 will assume extended addressing (usually 23 bits).
633 -mcpu=CPU_VERSION
635 Sets the CPU version being compiled for.
636 -merrors-to-file FILENAME
638 Redirect error output to a file, for broken systems which don't
639 support such behaviour in the shell.
640 The following options are available when as is configured for a MIPS
642 processor.
643 -G num
645 This option sets the largest size of an object that can be refer‐
646 enced implicitly with the "gp" register. It is only accepted for
647 targets that use ECOFF format, such as a DECstation running Ultrix.
648 The default value is 8.
649 -EB Generate "big endian" format output.
651 -EL Generate "little endian" format output.
653 -mips1
655 -mips2
656 -mips3
657 -mips4
658 -mips5
659 -mips32
660 -mips32r2
661 -mips64
662 -mips64r2
663 Generate code for a particular MIPS Instruction Set Architecture
664 level. -mips1 is an alias for -march=r3000, -mips2 is an alias for
665 -march=r6000, -mips3 is an alias for -march=r4000 and -mips4 is an
666 alias for -march=r8000. -mips5, -mips32, -mips32r2, -mips64, and
667 -mips64r2 correspond to generic MIPS V, MIPS32, MIPS32 Release 2,
668 MIPS64, and MIPS64 Release 2 ISA processors, respectively.
669 -march=CPU
671 Generate code for a particular MIPS cpu.
672 -mtune=cpu
674 Schedule and tune for a particular MIPS cpu.
675 -mfix7000
677 -mno-fix7000
678 Cause nops to be inserted if the read of the destination register
679 of an mfhi or mflo instruction occurs in the following two instruc‐
680 tions.
681 -mdebug
683 -no-mdebug
684 Cause stabs-style debugging output to go into an ECOFF-style .mde‐
685 bug section instead of the standard ELF .stabs sections.
686 -mpdr
688 -mno-pdr
689 Control generation of ".pdr" sections.
690 -mgp32
692 -mfp32
693 The register sizes are normally inferred from the ISA and ABI, but
694 these flags force a certain group of registers to be treated as 32
695 bits wide at all times. -mgp32 controls the size of general-pur‐
696 pose registers and -mfp32 controls the size of floating-point reg‐
697 isters.
698 -mips16
700 -no-mips16
701 Generate code for the MIPS 16 processor. This is equivalent to
702 putting ".set mips16" at the start of the assembly file.
703 -no-mips16 turns off this option.
704 -msmartmips
706 -mno-smartmips
707 Enables the SmartMIPS extension to the MIPS32 instruction set. This
708 is equivalent to putting ".set smartmips" at the start of the
709 assembly file. -mno-smartmips turns off this option.
710 -mips3d
712 -no-mips3d
713 Generate code for the MIPS-3D Application Specific Extension. This
714 tells the assembler to accept MIPS-3D instructions. -no-mips3d
715 turns off this option.
716 -mdmx
718 -no-mdmx
719 Generate code for the MDMX Application Specific Extension. This
720 tells the assembler to accept MDMX instructions. -no-mdmx turns
721 off this option.
722 -mdsp
724 -mno-dsp
725 Generate code for the DSP Release 1 Application Specific Extension.
726 This tells the assembler to accept DSP Release 1 instructions.
727 -mno-dsp turns off this option.
728 -mdspr2
730 -mno-dspr2
731 Generate code for the DSP Release 2 Application Specific Extension.
732 This option implies -mdsp. This tells the assembler to accept DSP
733 Release 2 instructions. -mno-dspr2 turns off this option.
734 -mmt
736 -mno-mt
737 Generate code for the MT Application Specific Extension. This
738 tells the assembler to accept MT instructions. -mno-mt turns off
739 this option.
740 --construct-floats
742 --no-construct-floats
743 The --no-construct-floats option disables the construction of dou‐
744 ble width floating point constants by loading the two halves of the
745 value into the two single width floating point registers that make
746 up the double width register. By default --construct-floats is
747 selected, allowing construction of these floating point constants.
748 --emulation=name
750 This option causes as to emulate as configured for some other tar‐
751 get, in all respects, including output format (choosing between ELF
752 and ECOFF only), handling of pseudo-opcodes which may generate
753 debugging information or store symbol table information, and
754 default endianness. The available configuration names are: mipsec‐
755 off, mipself, mipslecoff, mipsbecoff, mipslelf, mipsbelf. The
756 first two do not alter the default endianness from that of the pri‐
757 mary target for which the assembler was configured; the others
758 change the default to little- or big-endian as indicated by the b
759 or l in the name. Using -EB or -EL will override the endianness
760 selection in any case.
761 This option is currently supported only when the primary target as
763 is configured for is a MIPS ELF or ECOFF target. Furthermore, the
764 primary target or others specified with --enable-targets=... at
765 configuration time must include support for the other format, if
766 both are to be available. For example, the Irix 5 configuration
767 includes support for both.
768 Eventually, this option will support more configurations, with more
770 fine-grained control over the assembler's behavior, and will be
771 supported for more processors.
772 -nocpp
774 as ignores this option. It is accepted for compatibility with the
775 native tools.
776 --trap
778 --no-trap
779 --break
780 --no-break
781 Control how to deal with multiplication overflow and division by
782 zero. --trap or --no-break (which are synonyms) take a trap excep‐
783 tion (and only work for Instruction Set Architecture level 2 and
784 higher); --break or --no-trap (also synonyms, and the default) take
785 a break exception.
786 -n When this option is used, as will issue a warning every time it
788 generates a nop instruction from a macro.
789 The following options are available when as is configured for an MCore
791 processor.
792 -jsri2bsr
794 -nojsri2bsr
795 Enable or disable the JSRI to BSR transformation. By default this
796 is enabled. The command line option -nojsri2bsr can be used to
797 disable it.
798 -sifilter
800 -nosifilter
801 Enable or disable the silicon filter behaviour. By default this is
802 disabled. The default can be overridden by the -sifilter command
803 line option.
804 -relax
806 Alter jump instructions for long displacements.
807 -mcpu=[210⎪340]
809 Select the cpu type on the target hardware. This controls which
810 instructions can be assembled.
811 -EB Assemble for a big endian target.
813 -EL Assemble for a little endian target.
815 See the info pages for documentation of the MMIX-specific options.
817 The following options are available when as is configured for an Xtensa
819 processor.
820 --text-section-literals ⎪ --no-text-section-literals
822 With --text-section-literals, literal pools are interspersed in the
823 text section. The default is --no-text-section-literals, which
824 places literals in a separate section in the output file. These
825 options only affect literals referenced via PC-relative "L32R"
826 instructions; literals for absolute mode "L32R" instructions are
827 handled separately.
828 --absolute-literals ⎪ --no-absolute-literals
830 Indicate to the assembler whether "L32R" instructions use absolute
831 or PC-relative addressing. The default is to assume absolute
832 addressing if the Xtensa processor includes the absolute "L32R"
833 addressing option. Otherwise, only the PC-relative "L32R" mode can
834 be used.
835 --target-align ⎪ --no-target-align
837 Enable or disable automatic alignment to reduce branch penalties at
838 the expense of some code density. The default is --target-align.
839 --longcalls ⎪ --no-longcalls
841 Enable or disable transformation of call instructions to allow
842 calls across a greater range of addresses. The default is
843 --no-longcalls.
844 --transform ⎪ --no-transform
846 Enable or disable all assembler transformations of Xtensa instruc‐
847 tions. The default is --transform; --no-transform should be used
848 only in the rare cases when the instructions must be exactly as
849 specified in the assembly source.
850 --rename-section oldname=newname
852 When generating output sections, rename the oldname section to new‐
853 name.
854 The following options are available when as is configured for a Z80
856 family processor.
857 -z80
859 Assemble for Z80 processor.
860 -r800
862 Assemble for R800 processor.
863 -ignore-undocumented-instructions
865 -Wnud
866 Assemble undocumented Z80 instructions that also work on R800 with‐
867 out warning.
868 -ignore-unportable-instructions
870 -Wnup
871 Assemble all undocumented Z80 instructions without warning.
872 -warn-undocumented-instructions
874 -Wud
875 Issue a warning for undocumented Z80 instructions that also work on
876 R800.
877 -warn-unportable-instructions
879 -Wup
880 Issue a warning for undocumented Z80 instructions that do not work
881 on R800.
882 -forbid-undocumented-instructions
884 -Fud
885 Treat all undocumented instructions as errors.
886 -forbid-unportable-instructions
888 -Fup
889 Treat undocumented Z80 instructions that do not work on R800 as
890 errors.
891
893 gcc(1), ld(1), and the Info entries for binutils and ld.
894
896 Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
897 2006, 2007 Free Software Foundation, Inc.
898 Permission is granted to copy, distribute and/or modify this document
900 under the terms of the GNU Free Documentation License, Version 1.1 or
901 any later version published by the Free Software Foundation; with no
902 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
903 Texts. A copy of the license is included in the section entitled "GNU
904 Free Documentation License".
905binutils-2.18.92 2008-10-02 AS(1)