nds32: Support target directive .ict_model.
[deliverable/binutils-gdb.git] / gas / doc / as.texinfo
CommitLineData
252b5132 1\input texinfo @c -*-Texinfo-*-
219d1afa 2@c Copyright (C) 1991-2018 Free Software Foundation, Inc.
252b5132
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3@c UPDATE!! On future updates--
4@c (1) check for new machine-dep cmdline options in
5@c md_parse_option definitions in config/tc-*.c
6@c (2) for platform-specific directives, examine md_pseudo_op
7@c in config/tc-*.c
8@c (3) for object-format specific directives, examine obj_pseudo_op
01642c12 9@c in config/obj-*.c
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10@c (4) portable directives in potable[] in read.c
11@c %**start of header
12@setfilename as.info
13@c ---config---
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14@macro gcctabopt{body}
15@code{\body\}
16@end macro
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17@c defaults, config file may override:
18@set have-stabs
19@c ---
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20@c man begin NAME
21@c ---
252b5132 22@include asconfig.texi
c428fa83 23@include bfdver.texi
252b5132 24@c ---
0285c67d 25@c man end
4a4c4a1d 26@c ---
252b5132 27@c common OR combinations of conditions
c1253627
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28@ifset COFF
29@set COFF-ELF
30@end ifset
31@ifset ELF
32@set COFF-ELF
33@end ifset
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34@ifset AOUT
35@set aout-bout
36@end ifset
37@ifset ARM/Thumb
38@set ARM
39@end ifset
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40@ifset Blackfin
41@set Blackfin
42@end ifset
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43@ifset BOUT
44@set aout-bout
45@end ifset
46@ifset H8/300
47@set H8
48@end ifset
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49@ifset SH
50@set H8
51@end ifset
52@ifset HPPA
53@set abnormal-separator
54@end ifset
55@c ------------
56@ifset GENERIC
57@settitle Using @value{AS}
58@end ifset
59@ifclear GENERIC
60@settitle Using @value{AS} (@value{TARGET})
61@end ifclear
62@setchapternewpage odd
63@c %**end of header
64
65@c @smallbook
66@c @set SMALL
67@c WARE! Some of the machine-dependent sections contain tables of machine
68@c instructions. Except in multi-column format, these tables look silly.
69@c Unfortunately, Texinfo doesn't have a general-purpose multi-col format, so
70@c the multi-col format is faked within @example sections.
01642c12 71@c
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72@c Again unfortunately, the natural size that fits on a page, for these tables,
73@c is different depending on whether or not smallbook is turned on.
74@c This matters, because of order: text flow switches columns at each page
75@c break.
01642c12 76@c
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77@c The format faked in this source works reasonably well for smallbook,
78@c not well for the default large-page format. This manual expects that if you
79@c turn on @smallbook, you will also uncomment the "@set SMALL" to enable the
80@c tables in question. You can turn on one without the other at your
01642c12 81@c discretion, of course.
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82@ifinfo
83@set SMALL
84@c the insn tables look just as silly in info files regardless of smallbook,
85@c might as well show 'em anyways.
86@end ifinfo
87
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88@ifnottex
89@dircategory Software development
90@direntry
252b5132 91* As: (as). The GNU assembler.
59455fb1 92* Gas: (as). The GNU assembler.
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93@end direntry
94@end ifnottex
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95
96@finalout
97@syncodeindex ky cp
98
0e9517a9 99@copying
252b5132
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100This file documents the GNU Assembler "@value{AS}".
101
0285c67d 102@c man begin COPYRIGHT
219d1afa 103Copyright @copyright{} 1991-2018 Free Software Foundation, Inc.
252b5132 104
0285c67d 105Permission is granted to copy, distribute and/or modify this document
793c5807 106under the terms of the GNU Free Documentation License, Version 1.3
0285c67d
NC
107or any later version published by the Free Software Foundation;
108with no Invariant Sections, with no Front-Cover Texts, and with no
109Back-Cover Texts. A copy of the license is included in the
c1253627 110section entitled ``GNU Free Documentation License''.
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111
112@c man end
0e9517a9 113@end copying
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114
115@titlepage
116@title Using @value{AS}
117@subtitle The @sc{gnu} Assembler
118@ifclear GENERIC
119@subtitle for the @value{TARGET} family
120@end ifclear
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121@ifset VERSION_PACKAGE
122@sp 1
123@subtitle @value{VERSION_PACKAGE}
124@end ifset
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125@sp 1
126@subtitle Version @value{VERSION}
127@sp 1
128@sp 13
b45619c0 129The Free Software Foundation Inc.@: thanks The Nice Computer
252b5132 130Company of Australia for loaning Dean Elsner to write the
a4fb0134 131first (Vax) version of @command{as} for Project @sc{gnu}.
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132The proprietors, management and staff of TNCCA thank FSF for
133distracting the boss while they got some work
134done.
135@sp 3
136@author Dean Elsner, Jay Fenlason & friends
137@page
138@tex
139{\parskip=0pt
140\hfill {\it Using {\tt @value{AS}}}\par
141\hfill Edited by Cygnus Support\par
142}
143%"boxit" macro for figures:
144%Modified from Knuth's ``boxit'' macro from TeXbook (answer to exercise 21.3)
145\gdef\boxit#1#2{\vbox{\hrule\hbox{\vrule\kern3pt
146 \vbox{\parindent=0pt\parskip=0pt\hsize=#1\kern3pt\strut\hfil
147#2\hfil\strut\kern3pt}\kern3pt\vrule}\hrule}}%box with visible outline
148\gdef\ibox#1#2{\hbox to #1{#2\hfil}\kern8pt}% invisible box
149@end tex
150
151@vskip 0pt plus 1filll
219d1afa 152Copyright @copyright{} 1991-2018 Free Software Foundation, Inc.
252b5132 153
cf055d54 154 Permission is granted to copy, distribute and/or modify this document
793c5807 155 under the terms of the GNU Free Documentation License, Version 1.3
cf055d54
NC
156 or any later version published by the Free Software Foundation;
157 with no Invariant Sections, with no Front-Cover Texts, and with no
158 Back-Cover Texts. A copy of the license is included in the
c1253627 159 section entitled ``GNU Free Documentation License''.
252b5132 160
252b5132 161@end titlepage
4ecceb71 162@contents
252b5132 163
2e64b665 164@ifnottex
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165@node Top
166@top Using @value{AS}
167
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168This file is a user guide to the @sc{gnu} assembler @command{@value{AS}}
169@ifset VERSION_PACKAGE
170@value{VERSION_PACKAGE}
171@end ifset
172version @value{VERSION}.
252b5132 173@ifclear GENERIC
a4fb0134 174This version of the file describes @command{@value{AS}} configured to generate
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175code for @value{TARGET} architectures.
176@end ifclear
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177
178This document is distributed under the terms of the GNU Free
179Documentation License. A copy of the license is included in the
c1253627 180section entitled ``GNU Free Documentation License''.
cf055d54 181
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182@menu
183* Overview:: Overview
184* Invoking:: Command-Line Options
185* Syntax:: Syntax
186* Sections:: Sections and Relocation
187* Symbols:: Symbols
188* Expressions:: Expressions
189* Pseudo Ops:: Assembler Directives
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190@ifset ELF
191* Object Attributes:: Object Attributes
192@end ifset
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193* Machine Dependencies:: Machine Dependent Features
194* Reporting Bugs:: Reporting Bugs
195* Acknowledgements:: Who Did What
cf055d54 196* GNU Free Documentation License:: GNU Free Documentation License
28c9d252 197* AS Index:: AS Index
252b5132 198@end menu
2e64b665 199@end ifnottex
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200
201@node Overview
202@chapter Overview
203@iftex
a4fb0134 204This manual is a user guide to the @sc{gnu} assembler @command{@value{AS}}.
252b5132 205@ifclear GENERIC
a4fb0134 206This version of the manual describes @command{@value{AS}} configured to generate
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207code for @value{TARGET} architectures.
208@end ifclear
209@end iftex
210
211@cindex invocation summary
212@cindex option summary
213@cindex summary of options
a4fb0134 214Here is a brief summary of how to invoke @command{@value{AS}}. For details,
96e9638b 215see @ref{Invoking,,Command-Line Options}.
252b5132 216
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217@c man title AS the portable GNU assembler.
218
a4fb0134 219@ignore
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220@c man begin SEEALSO
221gcc(1), ld(1), and the Info entries for @file{binutils} and @file{ld}.
222@c man end
a4fb0134 223@end ignore
0285c67d 224
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225@c We don't use deffn and friends for the following because they seem
226@c to be limited to one line for the header.
227@smallexample
0285c67d 228@c man begin SYNOPSIS
83f10cb2 229@value{AS} [@b{-a}[@b{cdghlns}][=@var{file}]] [@b{--alternate}] [@b{-D}]
955974c6 230 [@b{--compress-debug-sections}] [@b{--nocompress-debug-sections}]
3d6b762c 231 [@b{--debug-prefix-map} @var{old}=@var{new}]
4bdd3565 232 [@b{--defsym} @var{sym}=@var{val}] [@b{-f}] [@b{-g}] [@b{--gstabs}]
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233 [@b{--gstabs+}] [@b{--gdwarf-2}] [@b{--gdwarf-sections}]
234 [@b{--help}] [@b{-I} @var{dir}] [@b{-J}]
4bdd3565
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235 [@b{-K}] [@b{-L}] [@b{--listing-lhs-width}=@var{NUM}]
236 [@b{--listing-lhs-width2}=@var{NUM}] [@b{--listing-rhs-width}=@var{NUM}]
d60646b9 237 [@b{--listing-cont-lines}=@var{NUM}] [@b{--keep-locals}]
2edb36e7 238 [@b{--no-pad-sections}]
d60646b9
NC
239 [@b{-o} @var{objfile}] [@b{-R}]
240 [@b{--hash-size}=@var{NUM}] [@b{--reduce-memory-overheads}]
241 [@b{--statistics}]
242 [@b{-v}] [@b{-version}] [@b{--version}]
243 [@b{-W}] [@b{--warn}] [@b{--fatal-warnings}] [@b{-w}] [@b{-x}]
244 [@b{-Z}] [@b{@@@var{FILE}}]
451133ce 245 [@b{--sectname-subst}] [@b{--size-check=[error|warning]}]
b8871f35 246 [@b{--elf-stt-common=[no|yes]}]
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247 [@b{--target-help}] [@var{target-options}]
248 [@b{--}|@var{files} @dots{}]
a4fb0134 249@c
6387924a 250@c man end
a4fb0134 251@c Target dependent options are listed below. Keep the list sorted.
01642c12 252@c Add an empty line for separation.
6387924a 253@c man begin TARGET
a06ea964
NC
254@ifset AARCH64
255
256@emph{Target AArch64 options:}
257 [@b{-EB}|@b{-EL}]
69091a2c 258 [@b{-mabi}=@var{ABI}]
a06ea964 259@end ifset
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RH
260@ifset ALPHA
261
262@emph{Target Alpha options:}
263 [@b{-m@var{cpu}}]
264 [@b{-mdebug} | @b{-no-mdebug}]
198f1251 265 [@b{-replace} | @b{-noreplace}]
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266 [@b{-relax}] [@b{-g}] [@b{-G@var{size}}]
267 [@b{-F}] [@b{-32addr}]
268@end ifset
252b5132 269@ifset ARC
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270
271@emph{Target ARC options:}
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272 [@b{-mcpu=@var{cpu}}]
273 [@b{-mA6}|@b{-mARC600}|@b{-mARC601}|@b{-mA7}|@b{-mARC700}|@b{-mEM}|@b{-mHS}]
274 [@b{-mcode-density}]
4670103e 275 [@b{-mrelax}]
a4fb0134 276 [@b{-EB}|@b{-EL}]
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277@end ifset
278@ifset ARM
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279
280@emph{Target ARM options:}
03b1477f 281@c Don't document the deprecated options
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282 [@b{-mcpu}=@var{processor}[+@var{extension}@dots{}]]
283 [@b{-march}=@var{architecture}[+@var{extension}@dots{}]]
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PB
284 [@b{-mfpu}=@var{floating-point-format}]
285 [@b{-mfloat-abi}=@var{abi}]
d507cf36 286 [@b{-meabi}=@var{ver}]
03b1477f 287 [@b{-mthumb}]
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288 [@b{-EB}|@b{-EL}]
289 [@b{-mapcs-32}|@b{-mapcs-26}|@b{-mapcs-float}|
290 @b{-mapcs-reentrant}]
7f266840 291 [@b{-mthumb-interwork}] [@b{-k}]
252b5132 292@end ifset
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293@ifset Blackfin
294
295@emph{Target Blackfin options:}
296 [@b{-mcpu}=@var{processor}[-@var{sirevision}]]
297 [@b{-mfdpic}]
298 [@b{-mno-fdpic}]
299 [@b{-mnopic}]
300@end ifset
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HPN
301@ifset CRIS
302
303@emph{Target CRIS options:}
304 [@b{--underscore} | @b{--no-underscore}]
305 [@b{--pic}] [@b{-N}]
306 [@b{--emulation=criself} | @b{--emulation=crisaout}]
ae57792d 307 [@b{--march=v0_v10} | @b{--march=v10} | @b{--march=v32} | @b{--march=common_v10_v32}]
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308@c Deprecated -- deliberately not documented.
309@c [@b{-h}] [@b{-H}]
310@end ifset
252b5132 311@ifset D10V
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312
313@emph{Target D10V options:}
314 [@b{-O}]
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315@end ifset
316@ifset D30V
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317
318@emph{Target D30V options:}
319 [@b{-O}|@b{-n}|@b{-N}]
252b5132 320@end ifset
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321@ifset EPIPHANY
322
323@emph{Target EPIPHANY options:}
324 [@b{-mepiphany}|@b{-mepiphany16}]
325@end ifset
252b5132 326@ifset H8
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327
328@emph{Target H8/300 options:}
329 [-h-tick-hex]
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330@end ifset
331@ifset HPPA
332@c HPPA has no machine-dependent assembler options (yet).
333@end ifset
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334@ifset I80386
335
336@emph{Target i386 options:}
542385d9 337 [@b{--32}|@b{--x32}|@b{--64}] [@b{-n}]
1ef52f49 338 [@b{-march}=@var{CPU}[+@var{EXTENSION}@dots{}]] [@b{-mtune}=@var{CPU}]
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339@end ifset
340@ifset I960
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341
342@emph{Target i960 options:}
252b5132 343@c see md_parse_option in tc-i960.c
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344 [@b{-ACA}|@b{-ACA_A}|@b{-ACB}|@b{-ACC}|@b{-AKA}|@b{-AKB}|
345 @b{-AKC}|@b{-AMC}]
346 [@b{-b}] [@b{-no-relax}]
252b5132 347@end ifset
587fe2b3 348@ifset IA64
a4fb0134 349
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350@emph{Target IA-64 options:}
351 [@b{-mconstant-gp}|@b{-mauto-pic}]
352 [@b{-milp32}|@b{-milp64}|@b{-mlp64}|@b{-mp64}]
353 [@b{-mle}|@b{mbe}]
8c2fda1d 354 [@b{-mtune=itanium1}|@b{-mtune=itanium2}]
970d6792 355 [@b{-munwind-check=warning}|@b{-munwind-check=error}]
91d777ee 356 [@b{-mhint.b=ok}|@b{-mhint.b=warning}|@b{-mhint.b=error}]
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357 [@b{-x}|@b{-xexplicit}] [@b{-xauto}] [@b{-xdebug}]
358@end ifset
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359@ifset IP2K
360
361@emph{Target IP2K options:}
362 [@b{-mip2022}|@b{-mip2022ext}]
363@end ifset
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364@ifset M32C
365
366@emph{Target M32C options:}
c54b5932 367 [@b{-m32c}|@b{-m16c}] [-relax] [-h-tick-hex]
49f58d10 368@end ifset
587fe2b3 369@ifset M32R
9e32ca89 370
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371@emph{Target M32R options:}
372 [@b{--m32rx}|@b{--[no-]warn-explicit-parallel-conflicts}|
587fe2b3 373 @b{--W[n]p}]
ec694b89 374@end ifset
252b5132 375@ifset M680X0
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376
377@emph{Target M680X0 options:}
378 [@b{-l}] [@b{-m68000}|@b{-m68010}|@b{-m68020}|@dots{}]
252b5132 379@end ifset
60bcf0fa 380@ifset M68HC11
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381
382@emph{Target M68HC11 options:}
6927f982 383 [@b{-m68hc11}|@b{-m68hc12}|@b{-m68hcs12}|@b{-mm9s12x}|@b{-mm9s12xg}]
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384 [@b{-mshort}|@b{-mlong}]
385 [@b{-mshort-double}|@b{-mlong-double}]
1370e33d 386 [@b{--force-long-branches}] [@b{--short-branches}]
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387 [@b{--strict-direct-mode}] [@b{--print-insn-syntax}]
388 [@b{--print-opcodes}] [@b{--generate-example}]
389@end ifset
390@ifset MCORE
391
392@emph{Target MCORE options:}
393 [@b{-jsri2bsr}] [@b{-sifilter}] [@b{-relax}]
394 [@b{-mcpu=[210|340]}]
60bcf0fa 395@end ifset
a3c62988
NC
396@ifset METAG
397
398@emph{Target Meta options:}
399 [@b{-mcpu=@var{cpu}}] [@b{-mfpu=@var{cpu}}] [@b{-mdsp=@var{cpu}}]
400@end ifset
7ba29e2a
NC
401@ifset MICROBLAZE
402@emph{Target MICROBLAZE options:}
403@c MicroBlaze has no machine-dependent assembler options.
404@end ifset
252b5132 405@ifset MIPS
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406
407@emph{Target MIPS options:}
78849248 408 [@b{-nocpp}] [@b{-EL}] [@b{-EB}] [@b{-O}[@var{optimization level}]]
437ee9d5 409 [@b{-g}[@var{debug level}]] [@b{-G} @var{num}] [@b{-KPIC}] [@b{-call_shared}]
0c000745 410 [@b{-non_shared}] [@b{-xgot} [@b{-mvxworks-pic}]
437ee9d5 411 [@b{-mabi}=@var{ABI}] [@b{-32}] [@b{-n32}] [@b{-64}] [@b{-mfp32}] [@b{-mgp32}]
351cdf24
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412 [@b{-mfp64}] [@b{-mgp64}] [@b{-mfpxx}]
413 [@b{-modd-spreg}] [@b{-mno-odd-spreg}]
437ee9d5 414 [@b{-march}=@var{CPU}] [@b{-mtune}=@var{CPU}] [@b{-mips1}] [@b{-mips2}]
af7ee8bf 415 [@b{-mips3}] [@b{-mips4}] [@b{-mips5}] [@b{-mips32}] [@b{-mips32r2}]
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AB
416 [@b{-mips32r3}] [@b{-mips32r5}] [@b{-mips32r6}] [@b{-mips64}] [@b{-mips64r2}]
417 [@b{-mips64r3}] [@b{-mips64r5}] [@b{-mips64r6}]
437ee9d5 418 [@b{-construct-floats}] [@b{-no-construct-floats}]
8b10b0b3 419 [@b{-mignore-branch-isa}] [@b{-mno-ignore-branch-isa}]
ba92f887 420 [@b{-mnan=@var{encoding}}]
437ee9d5 421 [@b{-trap}] [@b{-no-break}] [@b{-break}] [@b{-no-trap}]
437ee9d5 422 [@b{-mips16}] [@b{-no-mips16}]
25499ac7 423 [@b{-mmips16e2}] [@b{-mno-mips16e2}]
df58fc94 424 [@b{-mmicromips}] [@b{-mno-micromips}]
e16bfa71 425 [@b{-msmartmips}] [@b{-mno-smartmips}]
1f25f5d3 426 [@b{-mips3d}] [@b{-no-mips3d}]
deec1734 427 [@b{-mdmx}] [@b{-no-mdmx}]
2ef2b9ae 428 [@b{-mdsp}] [@b{-mno-dsp}]
8b082fb1 429 [@b{-mdspr2}] [@b{-mno-dspr2}]
8f4f9071 430 [@b{-mdspr3}] [@b{-mno-dspr3}]
56d438b1 431 [@b{-mmsa}] [@b{-mno-msa}]
7d64c587 432 [@b{-mxpa}] [@b{-mno-xpa}]
ef2e4d86 433 [@b{-mmt}] [@b{-mno-mt}]
dec0624d 434 [@b{-mmcu}] [@b{-mno-mcu}]
833794fc 435 [@b{-minsn32}] [@b{-mno-insn32}]
2babba43 436 [@b{-mfix7000}] [@b{-mno-fix7000}]
a8d14a88 437 [@b{-mfix-rm7000}] [@b{-mno-fix-rm7000}]
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MR
438 [@b{-mfix-vr4120}] [@b{-mno-fix-vr4120}]
439 [@b{-mfix-vr4130}] [@b{-mno-fix-vr4130}]
ecb4347a 440 [@b{-mdebug}] [@b{-no-mdebug}]
dcd410fe 441 [@b{-mpdr}] [@b{-mno-pdr}]
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442@end ifset
443@ifset MMIX
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444
445@emph{Target MMIX options:}
446 [@b{--fixed-special-register-names}] [@b{--globalize-symbols}]
447 [@b{--gnu-syntax}] [@b{--relax}] [@b{--no-predefined-symbols}]
448 [@b{--no-expand}] [@b{--no-merge-gregs}] [@b{-x}]
973eb340 449 [@b{--linker-allocated-gregs}]
a4fb0134 450@end ifset
36591ba1
SL
451@ifset NIOSII
452
453@emph{Target Nios II options:}
454 [@b{-relax-all}] [@b{-relax-section}] [@b{-no-relax}]
455 [@b{-EB}] [@b{-EL}]
456@end ifset
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457@ifset NDS32
458
459@emph{Target NDS32 options:}
460 [@b{-EL}] [@b{-EB}] [@b{-O}] [@b{-Os}] [@b{-mcpu=@var{cpu}}]
461 [@b{-misa=@var{isa}}] [@b{-mabi=@var{abi}}] [@b{-mall-ext}]
462 [@b{-m[no-]16-bit}] [@b{-m[no-]perf-ext}] [@b{-m[no-]perf2-ext}]
463 [@b{-m[no-]string-ext}] [@b{-m[no-]dsp-ext}] [@b{-m[no-]mac}] [@b{-m[no-]div}]
464 [@b{-m[no-]audio-isa-ext}] [@b{-m[no-]fpu-sp-ext}] [@b{-m[no-]fpu-dp-ext}]
465 [@b{-m[no-]fpu-fma}] [@b{-mfpu-freg=@var{FREG}}] [@b{-mreduced-regs}]
466 [@b{-mfull-regs}] [@b{-m[no-]dx-regs}] [@b{-mpic}] [@b{-mno-relax}]
467 [@b{-mb2bb}]
468@end ifset
a4fb0134
SC
469@ifset PDP11
470
471@emph{Target PDP11 options:}
472 [@b{-mpic}|@b{-mno-pic}] [@b{-mall}] [@b{-mno-extensions}]
473 [@b{-m}@var{extension}|@b{-mno-}@var{extension}]
01642c12 474 [@b{-m}@var{cpu}] [@b{-m}@var{machine}]
a4fb0134
SC
475@end ifset
476@ifset PJ
477
478@emph{Target picoJava options:}
479 [@b{-mb}|@b{-me}]
480@end ifset
481@ifset PPC
482
483@emph{Target PowerPC options:}
b8b738ac
AM
484 [@b{-a32}|@b{-a64}]
485 [@b{-mpwrx}|@b{-mpwr2}|@b{-mpwr}|@b{-m601}|@b{-mppc}|@b{-mppc32}|@b{-m603}|@b{-m604}|@b{-m403}|@b{-m405}|
486 @b{-m440}|@b{-m464}|@b{-m476}|@b{-m7400}|@b{-m7410}|@b{-m7450}|@b{-m7455}|@b{-m750cl}|@b{-mppc64}|
aea77599 487 @b{-m620}|@b{-me500}|@b{-e500x2}|@b{-me500mc}|@b{-me500mc64}|@b{-me5500}|@b{-me6500}|@b{-mppc64bridge}|
b36546d2 488 @b{-mbooke}|@b{-mpower4}|@b{-mpwr4}|@b{-mpower5}|@b{-mpwr5}|@b{-mpwr5x}|@b{-mpower6}|@b{-mpwr6}|
a680de9a 489 @b{-mpower7}|@b{-mpwr7}|@b{-mpower8}|@b{-mpwr8}|@b{-mpower9}|@b{-mpwr9}@b{-ma2}|
74081948 490 @b{-mcell}|@b{-mspe}|@b{-mspe2}|@b{-mtitan}|@b{-me300}|@b{-mcom}]
5817ffd1 491 [@b{-many}] [@b{-maltivec}|@b{-mvsx}|@b{-mhtm}|@b{-mvle}]
a4fb0134 492 [@b{-mregnames}|@b{-mno-regnames}]
b8b738ac
AM
493 [@b{-mrelocatable}|@b{-mrelocatable-lib}|@b{-K PIC}] [@b{-memb}]
494 [@b{-mlittle}|@b{-mlittle-endian}|@b{-le}|@b{-mbig}|@b{-mbig-endian}|@b{-be}]
a4fb0134 495 [@b{-msolaris}|@b{-mno-solaris}]
b8b738ac 496 [@b{-nops=@var{count}}]
a4fb0134 497@end ifset
93f11b16
DD
498@ifset PRU
499
500@emph{Target PRU options:}
501 [@b{-link-relax}]
502 [@b{-mnolink-relax}]
503 [@b{-mno-warn-regname-label}]
504@end ifset
b57e49f7
JW
505@ifset RISCV
506
507@emph{Target RISC-V options:}
508 [@b{-fpic}|@b{-fPIC}|@b{-fno-pic}]
509 [@b{-march}=@var{ISA}]
510 [@b{-mabi}=@var{ABI}]
511@end ifset
856ea05c
KP
512@ifset RL78
513
514@emph{Target RL78 options:}
515 [@b{-mg10}]
516 [@b{-m32bit-doubles}|@b{-m64bit-doubles}]
517@end ifset
c7927a3c
NC
518@ifset RX
519
520@emph{Target RX options:}
521 [@b{-mlittle-endian}|@b{-mbig-endian}]
c7927a3c 522 [@b{-m32bit-doubles}|@b{-m64bit-doubles}]
708e2187
NC
523 [@b{-muse-conventional-section-names}]
524 [@b{-msmall-data-limit}]
525 [@b{-mpid}]
526 [@b{-mrelax}]
527 [@b{-mint-register=@var{number}}]
528 [@b{-mgcc-abi}|@b{-mrx-abi}]
c7927a3c 529@end ifset
11c19e16
MS
530@ifset S390
531
532@emph{Target s390 options:}
533 [@b{-m31}|@b{-m64}] [@b{-mesa}|@b{-mzarch}] [@b{-march}=@var{CPU}]
534 [@b{-mregnames}|@b{-mno-regnames}]
535 [@b{-mwarn-areg-zero}]
536@end ifset
c3b7224a
NC
537@ifset SCORE
538
539@emph{Target SCORE options:}
540 [@b{-EB}][@b{-EL}][@b{-FIXDD}][@b{-NWARN}]
541 [@b{-SCORE5}][@b{-SCORE5U}][@b{-SCORE7}][@b{-SCORE3}]
542 [@b{-march=score7}][@b{-march=score3}]
543 [@b{-USE_R1}][@b{-KPIC}][@b{-O0}][@b{-G} @var{num}][@b{-V}]
544@end ifset
a4fb0134
SC
545@ifset SPARC
546
547@emph{Target SPARC options:}
548@c The order here is important. See c-sparc.texi.
46a2d504
JM
549 [@b{-Av6}|@b{-Av7}|@b{-Av8}|@b{-Aleon}|@b{-Asparclet}|@b{-Asparclite}
550 @b{-Av8plus}|@b{-Av8plusa}|@b{-Av8plusb}|@b{-Av8plusc}|@b{-Av8plusd}
551 @b{-Av8plusv}|@b{-Av8plusm}|@b{-Av9}|@b{-Av9a}|@b{-Av9b}|@b{-Av9c}
552 @b{-Av9d}|@b{-Av9e}|@b{-Av9v}|@b{-Av9m}|@b{-Asparc}|@b{-Asparcvis}
553 @b{-Asparcvis2}|@b{-Asparcfmaf}|@b{-Asparcima}|@b{-Asparcvis3}
554 @b{-Asparcvisr}|@b{-Asparc5}]
555 [@b{-xarch=v8plus}|@b{-xarch=v8plusa}]|@b{-xarch=v8plusb}|@b{-xarch=v8plusc}
556 @b{-xarch=v8plusd}|@b{-xarch=v8plusv}|@b{-xarch=v8plusm}|@b{-xarch=v9}
557 @b{-xarch=v9a}|@b{-xarch=v9b}|@b{-xarch=v9c}|@b{-xarch=v9d}|@b{-xarch=v9e}
558 @b{-xarch=v9v}|@b{-xarch=v9m}|@b{-xarch=sparc}|@b{-xarch=sparcvis}
559 @b{-xarch=sparcvis2}|@b{-xarch=sparcfmaf}|@b{-xarch=sparcima}
560 @b{-xarch=sparcvis3}|@b{-xarch=sparcvisr}|@b{-xarch=sparc5}
561 @b{-bump}]
a4fb0134 562 [@b{-32}|@b{-64}]
46a2d504 563 [@b{--enforce-aligned-data}][@b{--dcti-couples-detect}]
a4fb0134
SC
564@end ifset
565@ifset TIC54X
566
567@emph{Target TIC54X options:}
01642c12 568 [@b{-mcpu=54[123589]}|@b{-mcpu=54[56]lp}] [@b{-mfar-mode}|@b{-mf}]
a4fb0134
SC
569 [@b{-merrors-to-file} @var{<filename>}|@b{-me} @var{<filename>}]
570@end ifset
40b36596
JM
571@ifset TIC6X
572
573@emph{Target TIC6X options:}
98d23bef
BS
574 [@b{-march=@var{arch}}] [@b{-mbig-endian}|@b{-mlittle-endian}]
575 [@b{-mdsbt}|@b{-mno-dsbt}] [@b{-mpid=no}|@b{-mpid=near}|@b{-mpid=far}]
576 [@b{-mpic}|@b{-mno-pic}]
40b36596 577@end ifset
aa137e4d
NC
578@ifset TILEGX
579
580@emph{Target TILE-Gx options:}
fb6cedde 581 [@b{-m32}|@b{-m64}][@b{-EB}][@b{-EL}]
aa137e4d
NC
582@end ifset
583@ifset TILEPRO
584@c TILEPro has no machine-dependent assembler options
585@end ifset
b6605ddd 586@ifset VISIUM
40b36596 587
b6605ddd
EB
588@emph{Target Visium options:}
589 [@b{-mtune=@var{arch}}]
590@end ifset
2d8b84ae
SA
591@ifset XTENSA
592
593@emph{Target Xtensa options:}
b46824bd
MF
594 [@b{--[no-]text-section-literals}] [@b{--[no-]auto-litpools}]
595 [@b{--[no-]absolute-literals}]
2d8b84ae
SA
596 [@b{--[no-]target-align}] [@b{--[no-]longcalls}]
597 [@b{--[no-]transform}]
598 [@b{--rename-section} @var{oldname}=@var{newname}]
a82c7d90 599 [@b{--[no-]trampolines}]
2d8b84ae 600@end ifset
3c9b82ba
NC
601@ifset Z80
602
603@emph{Target Z80 options:}
604 [@b{-z80}] [@b{-r800}]
605 [@b{ -ignore-undocumented-instructions}] [@b{-Wnud}]
606 [@b{ -ignore-unportable-instructions}] [@b{-Wnup}]
607 [@b{ -warn-undocumented-instructions}] [@b{-Wud}]
608 [@b{ -warn-unportable-instructions}] [@b{-Wup}]
609 [@b{ -forbid-undocumented-instructions}] [@b{-Fud}]
610 [@b{ -forbid-unportable-instructions}] [@b{-Fup}]
611@end ifset
a4fb0134 612@ifset Z8000
b6605ddd 613
a4fb0134 614@c Z8000 has no machine-dependent assembler options
252b5132 615@end ifset
e0001a05 616
0285c67d 617@c man end
252b5132
RH
618@end smallexample
619
0285c67d
NC
620@c man begin OPTIONS
621
a4fb0134 622@table @gcctabopt
38fc1cb1 623@include at-file.texi
a0b7da79 624
83f10cb2 625@item -a[cdghlmns]
252b5132
RH
626Turn on listings, in any of a variety of ways:
627
a4fb0134 628@table @gcctabopt
252b5132
RH
629@item -ac
630omit false conditionals
631
632@item -ad
633omit debugging directives
634
83f10cb2
NC
635@item -ag
636include general information, like @value{AS} version and options passed
637
252b5132
RH
638@item -ah
639include high-level source
640
641@item -al
642include assembly
643
644@item -am
645include macro expansions
646
647@item -an
648omit forms processing
649
650@item -as
651include symbols
652
653@item =file
654set the name of the listing file
655@end table
656
657You may combine these options; for example, use @samp{-aln} for assembly
658listing without forms processing. The @samp{=file} option, if used, must be
659the last one. By itself, @samp{-a} defaults to @samp{-ahls}.
660
caa32fe5 661@item --alternate
96e9638b
BW
662Begin in alternate macro mode.
663@ifclear man
664@xref{Altmacro,,@code{.altmacro}}.
665@end ifclear
caa32fe5 666
955974c6 667@item --compress-debug-sections
19a7fe52
L
668Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
669ELF ABI. The resulting object file may not be compatible with older
670linkers and object file utilities. Note if compression would make a
671given section @emph{larger} then it is not compressed.
955974c6 672
151411f8
L
673@ifset ELF
674@cindex @samp{--compress-debug-sections=} option
675@item --compress-debug-sections=none
676@itemx --compress-debug-sections=zlib
677@itemx --compress-debug-sections=zlib-gnu
678@itemx --compress-debug-sections=zlib-gabi
679These options control how DWARF debug sections are compressed.
680@option{--compress-debug-sections=none} is equivalent to
681@option{--nocompress-debug-sections}.
682@option{--compress-debug-sections=zlib} and
19a7fe52 683@option{--compress-debug-sections=zlib-gabi} are equivalent to
151411f8 684@option{--compress-debug-sections}.
19a7fe52
L
685@option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
686sections using zlib. The debug sections are renamed to begin with
687@samp{.zdebug}. Note if compression would make a given section
688@emph{larger} then it is not compressed nor renamed.
689
151411f8
L
690@end ifset
691
955974c6 692@item --nocompress-debug-sections
e12fe555
NC
693Do not compress DWARF debug sections. This is usually the default for all
694targets except the x86/x86_64, but a configure time option can be used to
695override this.
955974c6 696
252b5132
RH
697@item -D
698Ignored. This option is accepted for script compatibility with calls to
699other assemblers.
700
3d6b762c
JM
701@item --debug-prefix-map @var{old}=@var{new}
702When assembling files in directory @file{@var{old}}, record debugging
703information describing them as in @file{@var{new}} instead.
704
252b5132
RH
705@item --defsym @var{sym}=@var{value}
706Define the symbol @var{sym} to be @var{value} before assembling the input file.
707@var{value} must be an integer constant. As in C, a leading @samp{0x}
bf083c64
NC
708indicates a hexadecimal value, and a leading @samp{0} indicates an octal
709value. The value of the symbol can be overridden inside a source file via the
710use of a @code{.set} pseudo-op.
252b5132
RH
711
712@item -f
713``fast''---skip whitespace and comment preprocessing (assume source is
714compiler output).
715
329e276d
NC
716@item -g
717@itemx --gen-debug
718Generate debugging information for each assembler source line using whichever
719debug format is preferred by the target. This currently means either STABS,
720ECOFF or DWARF2.
721
252b5132
RH
722@item --gstabs
723Generate stabs debugging information for each assembler line. This
724may help debugging assembler code, if the debugger can handle it.
725
05da4302
NC
726@item --gstabs+
727Generate stabs debugging information for each assembler line, with GNU
728extensions that probably only gdb can handle, and that could make other
729debuggers crash or refuse to read your program. This
730may help debugging assembler code. Currently the only GNU extension is
731the location of the current working directory at assembling time.
732
329e276d 733@item --gdwarf-2
cdf82bcf 734Generate DWARF2 debugging information for each assembler line. This
c1253627 735may help debugging assembler code, if the debugger can handle it. Note---this
85a39694 736option is only supported by some targets, not all of them.
cdf82bcf 737
b40bf0a2
NC
738@item --gdwarf-sections
739Instead of creating a .debug_line section, create a series of
740.debug_line.@var{foo} sections where @var{foo} is the name of the
741corresponding code section. For example a code section called @var{.text.func}
742will have its dwarf line number information placed into a section called
743@var{.debug_line.text.func}. If the code section is just called @var{.text}
744then debug line section will still be called just @var{.debug_line} without any
745suffix.
746
b8871f35 747@ifset ELF
21be61f5
L
748@item --size-check=error
749@itemx --size-check=warning
750Issue an error or warning for invalid ELF .size directive.
751
b8871f35
L
752@item --elf-stt-common=no
753@itemx --elf-stt-common=yes
754These options control whether the ELF assembler should generate common
755symbols with the @code{STT_COMMON} type. The default can be controlled
756by a configure option @option{--enable-elf-stt-common}.
757@end ifset
758
252b5132
RH
759@item --help
760Print a summary of the command line options and exit.
761
ea20a7da
CC
762@item --target-help
763Print a summary of all target specific options and exit.
764
252b5132
RH
765@item -I @var{dir}
766Add directory @var{dir} to the search list for @code{.include} directives.
767
768@item -J
769Don't warn about signed overflow.
770
771@item -K
772@ifclear DIFF-TBL-KLUGE
773This option is accepted but has no effect on the @value{TARGET} family.
774@end ifclear
775@ifset DIFF-TBL-KLUGE
776Issue warnings when difference tables altered for long displacements.
777@end ifset
778
779@item -L
780@itemx --keep-locals
ba83aca1
BW
781Keep (in the symbol table) local symbols. These symbols start with
782system-specific local label prefixes, typically @samp{.L} for ELF systems
783or @samp{L} for traditional a.out systems.
784@ifclear man
785@xref{Symbol Names}.
786@end ifclear
252b5132 787
c3a27914
NC
788@item --listing-lhs-width=@var{number}
789Set the maximum width, in words, of the output data column for an assembler
790listing to @var{number}.
791
792@item --listing-lhs-width2=@var{number}
793Set the maximum width, in words, of the output data column for continuation
794lines in an assembler listing to @var{number}.
795
796@item --listing-rhs-width=@var{number}
797Set the maximum width of an input source line, as displayed in a listing, to
798@var{number} bytes.
799
800@item --listing-cont-lines=@var{number}
801Set the maximum number of lines printed in a listing for a single line of input
802to @var{number} + 1.
803
2edb36e7
NC
804@item --no-pad-sections
805Stop the assembler for padding the ends of output sections to the alignment
806of that section. The default is to pad the sections, but this can waste space
807which might be needed on targets which have tight memory constraints.
808
252b5132 809@item -o @var{objfile}
a4fb0134 810Name the object-file output from @command{@value{AS}} @var{objfile}.
252b5132
RH
811
812@item -R
813Fold the data section into the text section.
814
d60646b9 815@item --hash-size=@var{number}
4bdd3565
NC
816Set the default size of GAS's hash tables to a prime number close to
817@var{number}. Increasing this value can reduce the length of time it takes the
818assembler to perform its tasks, at the expense of increasing the assembler's
819memory requirements. Similarly reducing this value can reduce the memory
820requirements at the expense of speed.
821
822@item --reduce-memory-overheads
823This option reduces GAS's memory requirements, at the expense of making the
824assembly processes slower. Currently this switch is a synonym for
825@samp{--hash-size=4051}, but in the future it may have other effects as well.
826
451133ce
NP
827@ifset ELF
828@item --sectname-subst
829Honor substitution sequences in section names.
830@ifclear man
831@xref{Section Name Substitutions,,@code{.section @var{name}}}.
832@end ifclear
833@end ifset
834
252b5132
RH
835@item --statistics
836Print the maximum space (in bytes) and total time (in seconds) used by
837assembly.
838
839@item --strip-local-absolute
840Remove local absolute symbols from the outgoing symbol table.
841
842@item -v
843@itemx -version
a4fb0134 844Print the @command{as} version.
252b5132
RH
845
846@item --version
a4fb0134 847Print the @command{as} version and exit.
252b5132
RH
848
849@item -W
2bdd6cf5 850@itemx --no-warn
252b5132
RH
851Suppress warning messages.
852
2bdd6cf5
GK
853@item --fatal-warnings
854Treat warnings as errors.
855
856@item --warn
857Don't suppress warning messages or treat them as errors.
858
252b5132
RH
859@item -w
860Ignored.
861
862@item -x
863Ignored.
864
865@item -Z
866Generate an object file even after errors.
867
868@item -- | @var{files} @dots{}
869Standard input, or source files to assemble.
870
871@end table
2a633939
JM
872@c man end
873
a06ea964
NC
874@ifset AARCH64
875
876@ifclear man
877@xref{AArch64 Options}, for the options available when @value{AS} is configured
878for the 64-bit mode of the ARM Architecture (AArch64).
879@end ifclear
880
881@ifset man
882@c man begin OPTIONS
883The following options are available when @value{AS} is configured for the
88464-bit mode of the ARM Architecture (AArch64).
885@c man end
886@c man begin INCLUDE
887@include c-aarch64.texi
888@c ended inside the included file
889@end ifset
890
891@end ifset
892
2a633939
JM
893@ifset ALPHA
894
895@ifclear man
896@xref{Alpha Options}, for the options available when @value{AS} is configured
897for an Alpha processor.
898@end ifclear
899
900@ifset man
901@c man begin OPTIONS
902The following options are available when @value{AS} is configured for an Alpha
903processor.
904@c man end
905@c man begin INCLUDE
906@include c-alpha.texi
907@c ended inside the included file
908@end ifset
909
910@end ifset
252b5132 911
2a633939 912@c man begin OPTIONS
252b5132 913@ifset ARC
886a2506
NC
914The following options are available when @value{AS} is configured for an ARC
915processor.
252b5132 916
a4fb0134 917@table @gcctabopt
886a2506 918@item -mcpu=@var{cpu}
0d2bcfaf
NC
919This option selects the core processor variant.
920@item -EB | -EL
921Select either big-endian (-EB) or little-endian (-EL) output.
886a2506
NC
922@item -mcode-density
923Enable Code Density extenssion instructions.
252b5132
RH
924@end table
925@end ifset
926
927@ifset ARM
928The following options are available when @value{AS} is configured for the ARM
929processor family.
930
a4fb0134 931@table @gcctabopt
92081f48 932@item -mcpu=@var{processor}[+@var{extension}@dots{}]
cdf82bcf 933Specify which ARM processor variant is the target.
92081f48 934@item -march=@var{architecture}[+@var{extension}@dots{}]
cdf82bcf 935Specify which ARM architecture variant is used by the target.
03b1477f 936@item -mfpu=@var{floating-point-format}
a349d9dd 937Select which Floating Point architecture is the target.
33a392fb
PB
938@item -mfloat-abi=@var{abi}
939Select which floating point ABI is in use.
03b1477f
RE
940@item -mthumb
941Enable Thumb only instruction decoding.
7f266840 942@item -mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant
252b5132
RH
943Select which procedure calling convention is in use.
944@item -EB | -EL
945Select either big-endian (-EB) or little-endian (-EL) output.
cdf82bcf
NC
946@item -mthumb-interwork
947Specify that the code has been generated with interworking between Thumb and
948ARM code in mind.
2e6976a8
DG
949@item -mccs
950Turns on CodeComposer Studio assembly syntax compatibility mode.
cdf82bcf
NC
951@item -k
952Specify that PIC code has been generated.
252b5132
RH
953@end table
954@end ifset
635fb38d 955@c man end
252b5132 956
9982501a 957@ifset Blackfin
8611b8fd
MF
958
959@ifclear man
960@xref{Blackfin Options}, for the options available when @value{AS} is
961configured for the Blackfin processor family.
962@end ifclear
963
964@ifset man
965@c man begin OPTIONS
9982501a
JZ
966The following options are available when @value{AS} is configured for
967the Blackfin processor family.
8611b8fd
MF
968@c man end
969@c man begin INCLUDE
970@include c-bfin.texi
971@c ended inside the included file
972@end ifset
9982501a 973
9982501a
JZ
974@end ifset
975
635fb38d 976@c man begin OPTIONS
328eb32e
HPN
977@ifset CRIS
978See the info pages for documentation of the CRIS-specific options.
979@end ifset
980
252b5132
RH
981@ifset D10V
982The following options are available when @value{AS} is configured for
983a D10V processor.
a4fb0134 984@table @gcctabopt
252b5132
RH
985@cindex D10V optimization
986@cindex optimization, D10V
987@item -O
988Optimize output by parallelizing instructions.
989@end table
990@end ifset
991
992@ifset D30V
993The following options are available when @value{AS} is configured for a D30V
994processor.
a4fb0134 995@table @gcctabopt
252b5132
RH
996@cindex D30V optimization
997@cindex optimization, D30V
998@item -O
999Optimize output by parallelizing instructions.
1000
1001@cindex D30V nops
1002@item -n
1003Warn when nops are generated.
1004
1005@cindex D30V nops after 32-bit multiply
1006@item -N
1007Warn when a nop after a 32-bit multiply instruction is generated.
1008@end table
1009@end ifset
731caf76
L
1010@c man end
1011
cfb8c092
NC
1012@ifset EPIPHANY
1013The following options are available when @value{AS} is configured for the
1014Adapteva EPIPHANY series.
1015
56b13185
JR
1016@ifclear man
1017@xref{Epiphany Options}, for the options available when @value{AS} is
1018configured for an Epiphany processor.
1019@end ifclear
cfb8c092 1020
56b13185
JR
1021@ifset man
1022@c man begin OPTIONS
1023The following options are available when @value{AS} is configured for
1024an Epiphany processor.
1025@c man end
1026@c man begin INCLUDE
1027@include c-epiphany.texi
0c76cae8
AM
1028@c ended inside the included file
1029@end ifset
1030
1031@end ifset
1032
1033@ifset H8300
1034
1035@ifclear man
1036@xref{H8/300 Options}, for the options available when @value{AS} is configured
1037for an H8/300 processor.
1038@end ifclear
1039
1040@ifset man
1041@c man begin OPTIONS
1042The following options are available when @value{AS} is configured for an H8/300
1043processor.
1044@c man end
1045@c man begin INCLUDE
1046@include c-h8300.texi
56b13185
JR
1047@c ended inside the included file
1048@end ifset
cfb8c092 1049
cfb8c092
NC
1050@end ifset
1051
731caf76 1052@ifset I80386
252b5132 1053
731caf76
L
1054@ifclear man
1055@xref{i386-Options}, for the options available when @value{AS} is
1056configured for an i386 processor.
1057@end ifclear
1058
1059@ifset man
1060@c man begin OPTIONS
1061The following options are available when @value{AS} is configured for
1062an i386 processor.
1063@c man end
1064@c man begin INCLUDE
1065@include c-i386.texi
1066@c ended inside the included file
1067@end ifset
1068
1069@end ifset
1070
1071@c man begin OPTIONS
252b5132
RH
1072@ifset I960
1073The following options are available when @value{AS} is configured for the
1074Intel 80960 processor.
1075
a4fb0134 1076@table @gcctabopt
252b5132
RH
1077@item -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC
1078Specify which variant of the 960 architecture is the target.
1079
1080@item -b
1081Add code to collect statistics about branches taken.
1082
1083@item -no-relax
1084Do not alter compare-and-branch instructions for long displacements;
1085error if necessary.
1086
1087@end table
1088@end ifset
1089
a40cbfa3
NC
1090@ifset IP2K
1091The following options are available when @value{AS} is configured for the
ec88d317 1092Ubicom IP2K series.
a40cbfa3
NC
1093
1094@table @gcctabopt
1095
1096@item -mip2022ext
1097Specifies that the extended IP2022 instructions are allowed.
1098
1099@item -mip2022
8dfa0188 1100Restores the default behaviour, which restricts the permitted instructions to
a40cbfa3
NC
1101just the basic IP2022 ones.
1102
1103@end table
1104@end ifset
1105
49f58d10
JB
1106@ifset M32C
1107The following options are available when @value{AS} is configured for the
1108Renesas M32C and M16C processors.
1109
1110@table @gcctabopt
1111
1112@item -m32c
1113Assemble M32C instructions.
1114
1115@item -m16c
1116Assemble M16C instructions (the default).
1117
c54b5932
DD
1118@item -relax
1119Enable support for link-time relaxations.
1120
1121@item -h-tick-hex
1122Support H'00 style hex constants in addition to 0x00 style.
1123
49f58d10
JB
1124@end table
1125@end ifset
1126
ec694b89
NC
1127@ifset M32R
1128The following options are available when @value{AS} is configured for the
26597c86 1129Renesas M32R (formerly Mitsubishi M32R) series.
ec694b89 1130
a4fb0134 1131@table @gcctabopt
ec694b89
NC
1132
1133@item --m32rx
1134Specify which processor in the M32R family is the target. The default
1135is normally the M32R, but this option changes it to the M32RX.
1136
1137@item --warn-explicit-parallel-conflicts or --Wp
1138Produce warning messages when questionable parallel constructs are
01642c12 1139encountered.
ec694b89
NC
1140
1141@item --no-warn-explicit-parallel-conflicts or --Wnp
01642c12
RM
1142Do not produce warning messages when questionable parallel constructs are
1143encountered.
ec694b89
NC
1144
1145@end table
1146@end ifset
252b5132
RH
1147
1148@ifset M680X0
1149The following options are available when @value{AS} is configured for the
1150Motorola 68000 series.
1151
a4fb0134 1152@table @gcctabopt
252b5132
RH
1153
1154@item -l
1155Shorten references to undefined symbols, to one word instead of two.
1156
0285c67d
NC
1157@item -m68000 | -m68008 | -m68010 | -m68020 | -m68030
1158@itemx | -m68040 | -m68060 | -m68302 | -m68331 | -m68332
1159@itemx | -m68333 | -m68340 | -mcpu32 | -m5200
252b5132
RH
1160Specify what processor in the 68000 family is the target. The default
1161is normally the 68020, but this can be changed at configuration time.
1162
1163@item -m68881 | -m68882 | -mno-68881 | -mno-68882
1164The target machine does (or does not) have a floating-point coprocessor.
1165The default is to assume a coprocessor for 68020, 68030, and cpu32. Although
1166the basic 68000 is not compatible with the 68881, a combination of the
1167two can be specified, since it's possible to do emulation of the
1168coprocessor instructions with the main processor.
1169
1170@item -m68851 | -mno-68851
1171The target machine does (or does not) have a memory-management
1172unit coprocessor. The default is to assume an MMU for 68020 and up.
1173
1174@end table
1175@end ifset
1176
36591ba1
SL
1177@ifset NIOSII
1178
1179@ifclear man
1180@xref{Nios II Options}, for the options available when @value{AS} is configured
1181for an Altera Nios II processor.
1182@end ifclear
1183
1184@ifset man
1185@c man begin OPTIONS
1186The following options are available when @value{AS} is configured for an
1187Altera Nios II processor.
1188@c man end
1189@c man begin INCLUDE
1190@include c-nios2.texi
1191@c ended inside the included file
1192@end ifset
1193@end ifset
1194
e135f41b
NC
1195@ifset PDP11
1196
1197For details about the PDP-11 machine dependent features options,
1198see @ref{PDP-11-Options}.
1199
a4fb0134 1200@table @gcctabopt
e135f41b
NC
1201@item -mpic | -mno-pic
1202Generate position-independent (or position-dependent) code. The
a4fb0134 1203default is @option{-mpic}.
e135f41b
NC
1204
1205@item -mall
1206@itemx -mall-extensions
1207Enable all instruction set extensions. This is the default.
1208
1209@item -mno-extensions
1210Disable all instruction set extensions.
1211
1212@item -m@var{extension} | -mno-@var{extension}
1213Enable (or disable) a particular instruction set extension.
1214
1215@item -m@var{cpu}
1216Enable the instruction set extensions supported by a particular CPU, and
1217disable all other extensions.
1218
1219@item -m@var{machine}
1220Enable the instruction set extensions supported by a particular machine
1221model, and disable all other extensions.
1222@end table
1223
1224@end ifset
1225
041dd5a9
ILT
1226@ifset PJ
1227The following options are available when @value{AS} is configured for
1228a picoJava processor.
1229
a4fb0134 1230@table @gcctabopt
041dd5a9
ILT
1231
1232@cindex PJ endianness
1233@cindex endianness, PJ
1234@cindex big endian output, PJ
1235@item -mb
1236Generate ``big endian'' format output.
1237
1238@cindex little endian output, PJ
1239@item -ml
1240Generate ``little endian'' format output.
1241
1242@end table
1243@end ifset
1244
93f11b16
DD
1245@ifset PRU
1246
1247@ifclear man
1248@xref{PRU Options}, for the options available when @value{AS} is configured
1249for a PRU processor.
1250@end ifclear
1251
1252@ifset man
1253@c man begin OPTIONS
1254The following options are available when @value{AS} is configured for a
1255PRU processor.
1256@c man end
1257@c man begin INCLUDE
1258@include c-pru.texi
1259@c ended inside the included file
1260@end ifset
1261@end ifset
1262
60bcf0fa
NC
1263@ifset M68HC11
1264The following options are available when @value{AS} is configured for the
1265Motorola 68HC11 or 68HC12 series.
1266
a4fb0134 1267@table @gcctabopt
60bcf0fa 1268
6927f982 1269@item -m68hc11 | -m68hc12 | -m68hcs12 | -mm9s12x | -mm9s12xg
60bcf0fa
NC
1270Specify what processor is the target. The default is
1271defined by the configuration option when building the assembler.
1272
6927f982
NC
1273@item --xgate-ramoffset
1274Instruct the linker to offset RAM addresses from S12X address space into
1275XGATE address space.
1276
2f904664
SC
1277@item -mshort
1278Specify to use the 16-bit integer ABI.
1279
1280@item -mlong
01642c12 1281Specify to use the 32-bit integer ABI.
2f904664
SC
1282
1283@item -mshort-double
01642c12 1284Specify to use the 32-bit double ABI.
2f904664
SC
1285
1286@item -mlong-double
01642c12 1287Specify to use the 64-bit double ABI.
2f904664 1288
1370e33d 1289@item --force-long-branches
60bcf0fa
NC
1290Relative branches are turned into absolute ones. This concerns
1291conditional branches, unconditional branches and branches to a
1292sub routine.
1293
1370e33d
NC
1294@item -S | --short-branches
1295Do not turn relative branches into absolute ones
60bcf0fa
NC
1296when the offset is out of range.
1297
1298@item --strict-direct-mode
1299Do not turn the direct addressing mode into extended addressing mode
1300when the instruction does not support direct addressing mode.
1301
1302@item --print-insn-syntax
1303Print the syntax of instruction in case of error.
1304
1305@item --print-opcodes
6927f982 1306Print the list of instructions with syntax and then exit.
60bcf0fa
NC
1307
1308@item --generate-example
6927f982 1309Print an example of instruction for each possible instruction and then exit.
a4fb0134 1310This option is only useful for testing @command{@value{AS}}.
60bcf0fa
NC
1311
1312@end table
1313@end ifset
1314
252b5132 1315@ifset SPARC
a4fb0134 1316The following options are available when @command{@value{AS}} is configured
252b5132
RH
1317for the SPARC architecture:
1318
a4fb0134 1319@table @gcctabopt
252b5132
RH
1320@item -Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite
1321@itemx -Av8plus | -Av8plusa | -Av9 | -Av9a
1322Explicitly select a variant of the SPARC architecture.
1323
1324@samp{-Av8plus} and @samp{-Av8plusa} select a 32 bit environment.
1325@samp{-Av9} and @samp{-Av9a} select a 64 bit environment.
1326
1327@samp{-Av8plusa} and @samp{-Av9a} enable the SPARC V9 instruction set with
1328UltraSPARC extensions.
1329
1330@item -xarch=v8plus | -xarch=v8plusa
1331For compatibility with the Solaris v9 assembler. These options are
1332equivalent to -Av8plus and -Av8plusa, respectively.
1333
1334@item -bump
1335Warn when the assembler switches to another architecture.
1336@end table
1337@end ifset
1338
39bec121
TW
1339@ifset TIC54X
1340The following options are available when @value{AS} is configured for the 'c54x
01642c12 1341architecture.
39bec121 1342
a4fb0134 1343@table @gcctabopt
39bec121
TW
1344@item -mfar-mode
1345Enable extended addressing mode. All addresses and relocations will assume
1346extended addressing (usually 23 bits).
1347@item -mcpu=@var{CPU_VERSION}
1348Sets the CPU version being compiled for.
1349@item -merrors-to-file @var{FILENAME}
1350Redirect error output to a file, for broken systems which don't support such
1351behaviour in the shell.
1352@end table
1353@end ifset
1354
252b5132 1355@ifset MIPS
73201331 1356@c man begin OPTIONS
252b5132 1357The following options are available when @value{AS} is configured for
98508b2a 1358a MIPS processor.
252b5132 1359
a4fb0134 1360@table @gcctabopt
252b5132
RH
1361@item -G @var{num}
1362This option sets the largest size of an object that can be referenced
1363implicitly with the @code{gp} register. It is only accepted for targets that
1364use ECOFF format, such as a DECstation running Ultrix. The default value is 8.
1365
1366@cindex MIPS endianness
1367@cindex endianness, MIPS
1368@cindex big endian output, MIPS
1369@item -EB
1370Generate ``big endian'' format output.
1371
1372@cindex little endian output, MIPS
1373@item -EL
1374Generate ``little endian'' format output.
1375
1376@cindex MIPS ISA
1377@item -mips1
1378@itemx -mips2
1379@itemx -mips3
e7af610e 1380@itemx -mips4
437ee9d5 1381@itemx -mips5
e7af610e 1382@itemx -mips32
af7ee8bf 1383@itemx -mips32r2
ae52f483
AB
1384@itemx -mips32r3
1385@itemx -mips32r5
7361da2c 1386@itemx -mips32r6
4058e45f 1387@itemx -mips64
5f74bc13 1388@itemx -mips64r2
ae52f483
AB
1389@itemx -mips64r3
1390@itemx -mips64r5
7361da2c 1391@itemx -mips64r6
98508b2a 1392Generate code for a particular MIPS Instruction Set Architecture level.
437ee9d5
TS
1393@samp{-mips1} is an alias for @samp{-march=r3000}, @samp{-mips2} is an
1394alias for @samp{-march=r6000}, @samp{-mips3} is an alias for
1395@samp{-march=r4000} and @samp{-mips4} is an alias for @samp{-march=r8000}.
ae52f483 1396@samp{-mips5}, @samp{-mips32}, @samp{-mips32r2}, @samp{-mips32r3},
7361da2c
AB
1397@samp{-mips32r5}, @samp{-mips32r6}, @samp{-mips64}, @samp{-mips64r2},
1398@samp{-mips64r3}, @samp{-mips64r5}, and @samp{-mips64r6} correspond to generic
1399MIPS V, MIPS32, MIPS32 Release 2, MIPS32 Release 3, MIPS32 Release 5, MIPS32
1400Release 6, MIPS64, MIPS64 Release 2, MIPS64 Release 3, MIPS64 Release 5, and
1401MIPS64 Release 6 ISA processors, respectively.
437ee9d5 1402
98508b2a
RS
1403@item -march=@var{cpu}
1404Generate code for a particular MIPS CPU.
437ee9d5
TS
1405
1406@item -mtune=@var{cpu}
98508b2a 1407Schedule and tune for a particular MIPS CPU.
437ee9d5
TS
1408
1409@item -mfix7000
1410@itemx -mno-fix7000
1411Cause nops to be inserted if the read of the destination register
1412of an mfhi or mflo instruction occurs in the following two instructions.
1413
a8d14a88
CM
1414@item -mfix-rm7000
1415@itemx -mno-fix-rm7000
1416Cause nops to be inserted if a dmult or dmultu instruction is
1417followed by a load instruction.
1418
ecb4347a
DJ
1419@item -mdebug
1420@itemx -no-mdebug
1421Cause stabs-style debugging output to go into an ECOFF-style .mdebug
1422section instead of the standard ELF .stabs sections.
1423
dcd410fe
RO
1424@item -mpdr
1425@itemx -mno-pdr
1426Control generation of @code{.pdr} sections.
1427
437ee9d5
TS
1428@item -mgp32
1429@itemx -mfp32
1430The register sizes are normally inferred from the ISA and ABI, but these
1431flags force a certain group of registers to be treated as 32 bits wide at
1432all times. @samp{-mgp32} controls the size of general-purpose registers
1433and @samp{-mfp32} controls the size of floating-point registers.
1434
351cdf24
MF
1435@item -mgp64
1436@itemx -mfp64
1437The register sizes are normally inferred from the ISA and ABI, but these
1438flags force a certain group of registers to be treated as 64 bits wide at
1439all times. @samp{-mgp64} controls the size of general-purpose registers
1440and @samp{-mfp64} controls the size of floating-point registers.
1441
1442@item -mfpxx
1443The register sizes are normally inferred from the ISA and ABI, but using
1444this flag in combination with @samp{-mabi=32} enables an ABI variant
1445which will operate correctly with floating-point registers which are
144632 or 64 bits wide.
1447
1448@item -modd-spreg
1449@itemx -mno-odd-spreg
1450Enable use of floating-point operations on odd-numbered single-precision
1451registers when supported by the ISA. @samp{-mfpxx} implies
1452@samp{-mno-odd-spreg}, otherwise the default is @samp{-modd-spreg}.
1453
437ee9d5
TS
1454@item -mips16
1455@itemx -no-mips16
1456Generate code for the MIPS 16 processor. This is equivalent to putting
32035f51 1457@code{.module mips16} at the start of the assembly file. @samp{-no-mips16}
437ee9d5 1458turns off this option.
252b5132 1459
25499ac7
MR
1460@item -mmips16e2
1461@itemx -mno-mips16e2
1462Enable the use of MIPS16e2 instructions in MIPS16 mode. This is equivalent
1463to putting @code{.module mips16e2} at the start of the assembly file.
1464@samp{-mno-mips16e2} turns off this option.
1465
df58fc94
RS
1466@item -mmicromips
1467@itemx -mno-micromips
1468Generate code for the microMIPS processor. This is equivalent to putting
32035f51
MR
1469@code{.module micromips} at the start of the assembly file.
1470@samp{-mno-micromips} turns off this option. This is equivalent to putting
1471@code{.module nomicromips} at the start of the assembly file.
df58fc94 1472
e16bfa71
TS
1473@item -msmartmips
1474@itemx -mno-smartmips
32035f51
MR
1475Enables the SmartMIPS extension to the MIPS32 instruction set. This is
1476equivalent to putting @code{.module smartmips} at the start of the assembly
1477file. @samp{-mno-smartmips} turns off this option.
e16bfa71 1478
1f25f5d3
CD
1479@item -mips3d
1480@itemx -no-mips3d
1481Generate code for the MIPS-3D Application Specific Extension.
1482This tells the assembler to accept MIPS-3D instructions.
1483@samp{-no-mips3d} turns off this option.
1484
deec1734
CD
1485@item -mdmx
1486@itemx -no-mdmx
1487Generate code for the MDMX Application Specific Extension.
1488This tells the assembler to accept MDMX instructions.
1489@samp{-no-mdmx} turns off this option.
1490
2ef2b9ae
CF
1491@item -mdsp
1492@itemx -mno-dsp
8b082fb1
TS
1493Generate code for the DSP Release 1 Application Specific Extension.
1494This tells the assembler to accept DSP Release 1 instructions.
2ef2b9ae
CF
1495@samp{-mno-dsp} turns off this option.
1496
8b082fb1
TS
1497@item -mdspr2
1498@itemx -mno-dspr2
1499Generate code for the DSP Release 2 Application Specific Extension.
8f4f9071 1500This option implies @samp{-mdsp}.
8b082fb1
TS
1501This tells the assembler to accept DSP Release 2 instructions.
1502@samp{-mno-dspr2} turns off this option.
1503
8f4f9071
MF
1504@item -mdspr3
1505@itemx -mno-dspr3
1506Generate code for the DSP Release 3 Application Specific Extension.
1507This option implies @samp{-mdsp} and @samp{-mdspr2}.
1508This tells the assembler to accept DSP Release 3 instructions.
1509@samp{-mno-dspr3} turns off this option.
1510
56d438b1
CF
1511@item -mmsa
1512@itemx -mno-msa
1513Generate code for the MIPS SIMD Architecture Extension.
1514This tells the assembler to accept MSA instructions.
1515@samp{-mno-msa} turns off this option.
1516
7d64c587
AB
1517@item -mxpa
1518@itemx -mno-xpa
1519Generate code for the MIPS eXtended Physical Address (XPA) Extension.
1520This tells the assembler to accept XPA instructions.
1521@samp{-mno-xpa} turns off this option.
1522
ef2e4d86
CF
1523@item -mmt
1524@itemx -mno-mt
1525Generate code for the MT Application Specific Extension.
1526This tells the assembler to accept MT instructions.
1527@samp{-mno-mt} turns off this option.
1528
dec0624d
MR
1529@item -mmcu
1530@itemx -mno-mcu
1531Generate code for the MCU Application Specific Extension.
1532This tells the assembler to accept MCU instructions.
1533@samp{-mno-mcu} turns off this option.
1534
833794fc
MR
1535@item -minsn32
1536@itemx -mno-insn32
1537Only use 32-bit instruction encodings when generating code for the
1538microMIPS processor. This option inhibits the use of any 16-bit
1539instructions. This is equivalent to putting @code{.set insn32} at
1540the start of the assembly file. @samp{-mno-insn32} turns off this
1541option. This is equivalent to putting @code{.set noinsn32} at the
1542start of the assembly file. By default @samp{-mno-insn32} is
1543selected, allowing all instructions to be used.
1544
437ee9d5
TS
1545@item --construct-floats
1546@itemx --no-construct-floats
1547The @samp{--no-construct-floats} option disables the construction of
1548double width floating point constants by loading the two halves of the
1549value into the two single width floating point registers that make up
1550the double width register. By default @samp{--construct-floats} is
1551selected, allowing construction of these floating point constants.
252b5132 1552
3bf0dbfb
MR
1553@item --relax-branch
1554@itemx --no-relax-branch
1555The @samp{--relax-branch} option enables the relaxation of out-of-range
1556branches. By default @samp{--no-relax-branch} is selected, causing any
1557out-of-range branches to produce an error.
1558
8b10b0b3
MR
1559@item -mignore-branch-isa
1560@itemx -mno-ignore-branch-isa
1561Ignore branch checks for invalid transitions between ISA modes. The
1562semantics of branches does not provide for an ISA mode switch, so in
1563most cases the ISA mode a branch has been encoded for has to be the
1564same as the ISA mode of the branch's target label. Therefore GAS has
1565checks implemented that verify in branch assembly that the two ISA
1566modes match. @samp{-mignore-branch-isa} disables these checks. By
1567default @samp{-mno-ignore-branch-isa} is selected, causing any invalid
1568branch requiring a transition between ISA modes to produce an error.
1569
ba92f887
MR
1570@item -mnan=@var{encoding}
1571Select between the IEEE 754-2008 (@option{-mnan=2008}) or the legacy
1572(@option{-mnan=legacy}) NaN encoding format. The latter is the default.
1573
252b5132
RH
1574@cindex emulation
1575@item --emulation=@var{name}
e8044f35
RS
1576This option was formerly used to switch between ELF and ECOFF output
1577on targets like IRIX 5 that supported both. MIPS ECOFF support was
1578removed in GAS 2.24, so the option now serves little purpose.
1579It is retained for backwards compatibility.
1580
1581The available configuration names are: @samp{mipself}, @samp{mipslelf} and
1582@samp{mipsbelf}. Choosing @samp{mipself} now has no effect, since the output
1583is always ELF. @samp{mipslelf} and @samp{mipsbelf} select little- and
1584big-endian output respectively, but @samp{-EL} and @samp{-EB} are now the
1585preferred options instead.
252b5132
RH
1586
1587@item -nocpp
a4fb0134 1588@command{@value{AS}} ignores this option. It is accepted for compatibility with
252b5132
RH
1589the native tools.
1590
252b5132
RH
1591@item --trap
1592@itemx --no-trap
1593@itemx --break
1594@itemx --no-break
1595Control how to deal with multiplication overflow and division by zero.
1596@samp{--trap} or @samp{--no-break} (which are synonyms) take a trap exception
1597(and only work for Instruction Set Architecture level 2 and higher);
1598@samp{--break} or @samp{--no-trap} (also synonyms, and the default) take a
1599break exception.
63486801
L
1600
1601@item -n
a4fb0134 1602When this option is used, @command{@value{AS}} will issue a warning every
63486801 1603time it generates a nop instruction from a macro.
252b5132 1604@end table
73201331 1605@c man end
252b5132
RH
1606@end ifset
1607
1608@ifset MCORE
1609The following options are available when @value{AS} is configured for
1610an MCore processor.
1611
a4fb0134 1612@table @gcctabopt
252b5132
RH
1613@item -jsri2bsr
1614@itemx -nojsri2bsr
1615Enable or disable the JSRI to BSR transformation. By default this is enabled.
1616The command line option @samp{-nojsri2bsr} can be used to disable it.
1617
1618@item -sifilter
1619@itemx -nosifilter
1620Enable or disable the silicon filter behaviour. By default this is disabled.
a349d9dd 1621The default can be overridden by the @samp{-sifilter} command line option.
252b5132
RH
1622
1623@item -relax
1624Alter jump instructions for long displacements.
1625
ec694b89
NC
1626@item -mcpu=[210|340]
1627Select the cpu type on the target hardware. This controls which instructions
1628can be assembled.
1629
1630@item -EB
1631Assemble for a big endian target.
1632
1633@item -EL
1634Assemble for a little endian target.
252b5132
RH
1635
1636@end table
1637@end ifset
a3c62988 1638@c man end
252b5132 1639
a3c62988
NC
1640@ifset METAG
1641
1642@ifclear man
1643@xref{Meta Options}, for the options available when @value{AS} is configured
1644for a Meta processor.
1645@end ifclear
1646
1647@ifset man
1648@c man begin OPTIONS
1649The following options are available when @value{AS} is configured for a
1650Meta processor.
1651@c man end
1652@c man begin INCLUDE
1653@include c-metag.texi
1654@c ended inside the included file
1655@end ifset
1656
1657@end ifset
1658
1659@c man begin OPTIONS
3c3bdf30
NC
1660@ifset MMIX
1661See the info pages for documentation of the MMIX-specific options.
1662@end ifset
1663
35c08157
KLC
1664@ifset NDS32
1665
1666@ifclear man
1667@xref{NDS32 Options}, for the options available when @value{AS} is configured
1668for a NDS32 processor.
1669@end ifclear
1670@c ended inside the included file
1671@end ifset
1672
1673@ifset man
1674@c man begin OPTIONS
1675The following options are available when @value{AS} is configured for a
1676NDS32 processor.
1677@c man end
1678@c man begin INCLUDE
1679@include c-nds32.texi
1680@c ended inside the included file
1681@end ifset
1682
635fb38d 1683@c man end
b8b738ac
AM
1684@ifset PPC
1685
1686@ifclear man
1687@xref{PowerPC-Opts}, for the options available when @value{AS} is configured
1688for a PowerPC processor.
1689@end ifclear
1690
1691@ifset man
1692@c man begin OPTIONS
1693The following options are available when @value{AS} is configured for a
1694PowerPC processor.
1695@c man end
1696@c man begin INCLUDE
1697@include c-ppc.texi
1698@c ended inside the included file
1699@end ifset
1700
1701@end ifset
1702
e23eba97
NC
1703@ifset RISCV
1704
1705@ifclear man
b57e49f7 1706@xref{RISC-V-Options}, for the options available when @value{AS} is configured
e23eba97
NC
1707for a RISC-V processor.
1708@end ifclear
1709
1710@ifset man
1711@c man begin OPTIONS
1712The following options are available when @value{AS} is configured for a
b57e49f7 1713RISC-V processor.
e23eba97
NC
1714@c man end
1715@c man begin INCLUDE
1716@include c-riscv.texi
1717@c ended inside the included file
1718@end ifset
1719
1720@end ifset
1721
635fb38d 1722@c man begin OPTIONS
046d31c2
NC
1723@ifset RX
1724See the info pages for documentation of the RX-specific options.
1725@end ifset
1726
11c19e16
MS
1727@ifset S390
1728The following options are available when @value{AS} is configured for the s390
1729processor family.
1730
1731@table @gcctabopt
1732@item -m31
1733@itemx -m64
1734Select the word size, either 31/32 bits or 64 bits.
1735@item -mesa
1736@item -mzarch
1737Select the architecture mode, either the Enterprise System
1738Architecture (esa) or the z/Architecture mode (zarch).
1739@item -march=@var{processor}
952c3f51
AK
1740Specify which s390 processor variant is the target, @samp{g5} (or
1741@samp{arch3}), @samp{g6}, @samp{z900} (or @samp{arch5}), @samp{z990} (or
1742@samp{arch6}), @samp{z9-109}, @samp{z9-ec} (or @samp{arch7}), @samp{z10} (or
1743@samp{arch8}), @samp{z196} (or @samp{arch9}), @samp{zEC12} (or @samp{arch10}),
47826cdb 1744@samp{z13} (or @samp{arch11}), or @samp{z14} (or @samp{arch12}).
11c19e16
MS
1745@item -mregnames
1746@itemx -mno-regnames
1747Allow or disallow symbolic names for registers.
1748@item -mwarn-areg-zero
1749Warn whenever the operand for a base or index register has been specified
1750but evaluates to zero.
1751@end table
1752@end ifset
2a633939 1753@c man end
11c19e16 1754
40b36596 1755@ifset TIC6X
2a633939
JM
1756
1757@ifclear man
1758@xref{TIC6X Options}, for the options available when @value{AS} is configured
1759for a TMS320C6000 processor.
1760@end ifclear
1761
1762@ifset man
1763@c man begin OPTIONS
40b36596
JM
1764The following options are available when @value{AS} is configured for a
1765TMS320C6000 processor.
2a633939
JM
1766@c man end
1767@c man begin INCLUDE
1768@include c-tic6x.texi
1769@c ended inside the included file
1770@end ifset
40b36596
JM
1771
1772@end ifset
1773
aa137e4d
NC
1774@ifset TILEGX
1775
1776@ifclear man
1777@xref{TILE-Gx Options}, for the options available when @value{AS} is configured
1778for a TILE-Gx processor.
1779@end ifclear
1780
1781@ifset man
1782@c man begin OPTIONS
1783The following options are available when @value{AS} is configured for a TILE-Gx
1784processor.
1785@c man end
1786@c man begin INCLUDE
1787@include c-tilegx.texi
1788@c ended inside the included file
1789@end ifset
1790
1791@end ifset
1792
b6605ddd
EB
1793@ifset VISIUM
1794
1795@ifclear man
1796@xref{Visium Options}, for the options available when @value{AS} is configured
1797for a Visium processor.
1798@end ifclear
1799
1800@ifset man
1801@c man begin OPTIONS
1802The following option is available when @value{AS} is configured for a Visium
1803processor.
1804@c man end
1805@c man begin INCLUDE
1806@include c-visium.texi
1807@c ended inside the included file
1808@end ifset
1809
1810@end ifset
1811
e0001a05 1812@ifset XTENSA
e0001a05 1813
2d8b84ae
SA
1814@ifclear man
1815@xref{Xtensa Options}, for the options available when @value{AS} is configured
1816for an Xtensa processor.
1817@end ifclear
1818
1819@ifset man
1820@c man begin OPTIONS
1821The following options are available when @value{AS} is configured for an
1822Xtensa processor.
1823@c man end
1824@c man begin INCLUDE
1825@include c-xtensa.texi
1826@c ended inside the included file
e0001a05
NC
1827@end ifset
1828
2d8b84ae
SA
1829@end ifset
1830
1831@c man begin OPTIONS
1832
3c9b82ba
NC
1833@ifset Z80
1834The following options are available when @value{AS} is configured for
1835a Z80 family processor.
1836@table @gcctabopt
1837@item -z80
1838Assemble for Z80 processor.
1839@item -r800
1840Assemble for R800 processor.
01642c12 1841@item -ignore-undocumented-instructions
3c9b82ba
NC
1842@itemx -Wnud
1843Assemble undocumented Z80 instructions that also work on R800 without warning.
01642c12 1844@item -ignore-unportable-instructions
3c9b82ba
NC
1845@itemx -Wnup
1846Assemble all undocumented Z80 instructions without warning.
01642c12 1847@item -warn-undocumented-instructions
3c9b82ba
NC
1848@itemx -Wud
1849Issue a warning for undocumented Z80 instructions that also work on R800.
01642c12 1850@item -warn-unportable-instructions
3c9b82ba 1851@itemx -Wup
01642c12
RM
1852Issue a warning for undocumented Z80 instructions that do not work on R800.
1853@item -forbid-undocumented-instructions
3c9b82ba
NC
1854@itemx -Fud
1855Treat all undocumented instructions as errors.
01642c12 1856@item -forbid-unportable-instructions
3c9b82ba 1857@itemx -Fup
b45619c0 1858Treat undocumented Z80 instructions that do not work on R800 as errors.
3c9b82ba
NC
1859@end table
1860@end ifset
1861
0285c67d
NC
1862@c man end
1863
252b5132
RH
1864@menu
1865* Manual:: Structure of this Manual
1866* GNU Assembler:: The GNU Assembler
1867* Object Formats:: Object File Formats
1868* Command Line:: Command Line
1869* Input Files:: Input Files
1870* Object:: Output (Object) File
1871* Errors:: Error and Warning Messages
1872@end menu
1873
1874@node Manual
1875@section Structure of this Manual
1876
1877@cindex manual, structure and purpose
1878This manual is intended to describe what you need to know to use
a4fb0134 1879@sc{gnu} @command{@value{AS}}. We cover the syntax expected in source files, including
252b5132 1880notation for symbols, constants, and expressions; the directives that
a4fb0134 1881@command{@value{AS}} understands; and of course how to invoke @command{@value{AS}}.
252b5132
RH
1882
1883@ifclear GENERIC
1884We also cover special features in the @value{TARGET}
a4fb0134 1885configuration of @command{@value{AS}}, including assembler directives.
252b5132
RH
1886@end ifclear
1887@ifset GENERIC
1888This manual also describes some of the machine-dependent features of
1889various flavors of the assembler.
1890@end ifset
1891
1892@cindex machine instructions (not covered)
1893On the other hand, this manual is @emph{not} intended as an introduction
1894to programming in assembly language---let alone programming in general!
1895In a similar vein, we make no attempt to introduce the machine
1896architecture; we do @emph{not} describe the instruction set, standard
1897mnemonics, registers or addressing modes that are standard to a
1898particular architecture.
1899@ifset GENERIC
1900You may want to consult the manufacturer's
1901machine architecture manual for this information.
1902@end ifset
1903@ifclear GENERIC
1904@ifset H8/300
1905For information on the H8/300 machine instruction set, see @cite{H8/300
c2dcd04e
NC
1906Series Programming Manual}. For the H8/300H, see @cite{H8/300H Series
1907Programming Manual} (Renesas).
252b5132 1908@end ifset
252b5132 1909@ifset SH
ef230218
JR
1910For information on the Renesas (formerly Hitachi) / SuperH SH machine instruction set,
1911see @cite{SH-Microcomputer User's Manual} (Renesas) or
1912@cite{SH-4 32-bit CPU Core Architecture} (SuperH) and
1913@cite{SuperH (SH) 64-Bit RISC Series} (SuperH).
252b5132
RH
1914@end ifset
1915@ifset Z8000
1916For information on the Z8000 machine instruction set, see @cite{Z8000 CPU Technical Manual}
1917@end ifset
1918@end ifclear
1919
1920@c I think this is premature---doc@cygnus.com, 17jan1991
1921@ignore
1922Throughout this manual, we assume that you are running @dfn{GNU},
1923the portable operating system from the @dfn{Free Software
1924Foundation, Inc.}. This restricts our attention to certain kinds of
1925computer (in particular, the kinds of computers that @sc{gnu} can run on);
1926once this assumption is granted examples and definitions need less
1927qualification.
1928
a4fb0134 1929@command{@value{AS}} is part of a team of programs that turn a high-level
252b5132
RH
1930human-readable series of instructions into a low-level
1931computer-readable series of instructions. Different versions of
a4fb0134 1932@command{@value{AS}} are used for different kinds of computer.
252b5132
RH
1933@end ignore
1934
1935@c There used to be a section "Terminology" here, which defined
1936@c "contents", "byte", "word", and "long". Defining "word" to any
1937@c particular size is confusing when the .word directive may generate 16
1938@c bits on one machine and 32 bits on another; in general, for the user
1939@c version of this manual, none of these terms seem essential to define.
1940@c They were used very little even in the former draft of the manual;
1941@c this draft makes an effort to avoid them (except in names of
1942@c directives).
1943
1944@node GNU Assembler
1945@section The GNU Assembler
1946
0285c67d
NC
1947@c man begin DESCRIPTION
1948
a4fb0134 1949@sc{gnu} @command{as} is really a family of assemblers.
252b5132 1950@ifclear GENERIC
a4fb0134 1951This manual describes @command{@value{AS}}, a member of that family which is
252b5132
RH
1952configured for the @value{TARGET} architectures.
1953@end ifclear
1954If you use (or have used) the @sc{gnu} assembler on one architecture, you
1955should find a fairly similar environment when you use it on another
1956architecture. Each version has much in common with the others,
1957including object file formats, most assembler directives (often called
1958@dfn{pseudo-ops}) and assembler syntax.@refill
1959
1960@cindex purpose of @sc{gnu} assembler
a4fb0134 1961@command{@value{AS}} is primarily intended to assemble the output of the
252b5132 1962@sc{gnu} C compiler @code{@value{GCC}} for use by the linker
a4fb0134 1963@code{@value{LD}}. Nevertheless, we've tried to make @command{@value{AS}}
252b5132
RH
1964assemble correctly everything that other assemblers for the same
1965machine would assemble.
1966@ifset VAX
1967Any exceptions are documented explicitly (@pxref{Machine Dependencies}).
1968@end ifset
1969@ifset M680X0
1970@c This remark should appear in generic version of manual; assumption
1971@c here is that generic version sets M680x0.
a4fb0134 1972This doesn't mean @command{@value{AS}} always uses the same syntax as another
252b5132
RH
1973assembler for the same architecture; for example, we know of several
1974incompatible versions of 680x0 assembly language syntax.
1975@end ifset
1976
0285c67d
NC
1977@c man end
1978
a4fb0134 1979Unlike older assemblers, @command{@value{AS}} is designed to assemble a source
252b5132
RH
1980program in one pass of the source file. This has a subtle impact on the
1981@kbd{.org} directive (@pxref{Org,,@code{.org}}).
1982
1983@node Object Formats
1984@section Object File Formats
1985
1986@cindex object file format
1987The @sc{gnu} assembler can be configured to produce several alternative
1988object file formats. For the most part, this does not affect how you
1989write assembly language programs; but directives for debugging symbols
1990are typically different in different file formats. @xref{Symbol
1991Attributes,,Symbol Attributes}.
1992@ifclear GENERIC
1993@ifclear MULTI-OBJ
c1253627 1994For the @value{TARGET} target, @command{@value{AS}} is configured to produce
252b5132
RH
1995@value{OBJ-NAME} format object files.
1996@end ifclear
1997@c The following should exhaust all configs that set MULTI-OBJ, ideally
252b5132 1998@ifset I960
a4fb0134 1999On the @value{TARGET}, @command{@value{AS}} can be configured to produce either
252b5132
RH
2000@code{b.out} or COFF format object files.
2001@end ifset
2002@ifset HPPA
a4fb0134 2003On the @value{TARGET}, @command{@value{AS}} can be configured to produce either
252b5132
RH
2004SOM or ELF format object files.
2005@end ifset
2006@end ifclear
2007
2008@node Command Line
2009@section Command Line
2010
2011@cindex command line conventions
0285c67d 2012
a4fb0134 2013After the program name @command{@value{AS}}, the command line may contain
252b5132
RH
2014options and file names. Options may appear in any order, and may be
2015before, after, or between file names. The order of file names is
2016significant.
2017
2018@cindex standard input, as input file
2019@kindex --
2020@file{--} (two hyphens) by itself names the standard input file
a4fb0134 2021explicitly, as one of the files for @command{@value{AS}} to assemble.
252b5132
RH
2022
2023@cindex options, command line
2024Except for @samp{--} any command line argument that begins with a
2025hyphen (@samp{-}) is an option. Each option changes the behavior of
a4fb0134 2026@command{@value{AS}}. No option changes the way another option works. An
252b5132
RH
2027option is a @samp{-} followed by one or more letters; the case of
2028the letter is important. All options are optional.
2029
2030Some options expect exactly one file name to follow them. The file
2031name may either immediately follow the option's letter (compatible
2032with older assemblers) or it may be the next command argument (@sc{gnu}
2033standard). These two command lines are equivalent:
2034
2035@smallexample
2036@value{AS} -o my-object-file.o mumble.s
2037@value{AS} -omy-object-file.o mumble.s
2038@end smallexample
2039
2040@node Input Files
2041@section Input Files
2042
2043@cindex input
2044@cindex source program
2045@cindex files, input
2046We use the phrase @dfn{source program}, abbreviated @dfn{source}, to
a4fb0134 2047describe the program input to one run of @command{@value{AS}}. The program may
252b5132
RH
2048be in one or more files; how the source is partitioned into files
2049doesn't change the meaning of the source.
2050
2051@c I added "con" prefix to "catenation" just to prove I can overcome my
2052@c APL training... doc@cygnus.com
2053The source program is a concatenation of the text in all the files, in the
2054order specified.
2055
0285c67d 2056@c man begin DESCRIPTION
a4fb0134 2057Each time you run @command{@value{AS}} it assembles exactly one source
252b5132
RH
2058program. The source program is made up of one or more files.
2059(The standard input is also a file.)
2060
a4fb0134 2061You give @command{@value{AS}} a command line that has zero or more input file
252b5132
RH
2062names. The input files are read (from left file name to right). A
2063command line argument (in any position) that has no special meaning
2064is taken to be an input file name.
2065
a4fb0134
SC
2066If you give @command{@value{AS}} no file names it attempts to read one input file
2067from the @command{@value{AS}} standard input, which is normally your terminal. You
2068may have to type @key{ctl-D} to tell @command{@value{AS}} there is no more program
252b5132
RH
2069to assemble.
2070
2071Use @samp{--} if you need to explicitly name the standard input file
2072in your command line.
2073
a4fb0134 2074If the source is empty, @command{@value{AS}} produces a small, empty object
252b5132
RH
2075file.
2076
0285c67d
NC
2077@c man end
2078
252b5132
RH
2079@subheading Filenames and Line-numbers
2080
2081@cindex input file linenumbers
2082@cindex line numbers, in input files
2083There are two ways of locating a line in the input file (or files) and
2084either may be used in reporting error messages. One way refers to a line
2085number in a physical file; the other refers to a line number in a
2086``logical'' file. @xref{Errors, ,Error and Warning Messages}.
2087
2088@dfn{Physical files} are those files named in the command line given
a4fb0134 2089to @command{@value{AS}}.
252b5132
RH
2090
2091@dfn{Logical files} are simply names declared explicitly by assembler
2092directives; they bear no relation to physical files. Logical file names help
a4fb0134
SC
2093error messages reflect the original source file, when @command{@value{AS}} source
2094is itself synthesized from other files. @command{@value{AS}} understands the
252b5132
RH
2095@samp{#} directives emitted by the @code{@value{GCC}} preprocessor. See also
2096@ref{File,,@code{.file}}.
2097
2098@node Object
2099@section Output (Object) File
2100
2101@cindex object file
2102@cindex output file
2103@kindex a.out
2104@kindex .o
a4fb0134 2105Every time you run @command{@value{AS}} it produces an output file, which is
252b5132
RH
2106your assembly language program translated into numbers. This file
2107is the object file. Its default name is
2108@ifclear BOUT
2109@code{a.out}.
2110@end ifclear
2111@ifset BOUT
2112@ifset GENERIC
01642c12 2113@code{a.out}, or
252b5132 2114@end ifset
a4fb0134 2115@code{b.out} when @command{@value{AS}} is configured for the Intel 80960.
252b5132 2116@end ifset
a4fb0134 2117You can give it another name by using the @option{-o} option. Conventionally,
252b5132
RH
2118object file names end with @file{.o}. The default name is used for historical
2119reasons: older assemblers were capable of assembling self-contained programs
2120directly into a runnable program. (For some formats, this isn't currently
2121possible, but it can be done for the @code{a.out} format.)
2122
2123@cindex linker
2124@kindex ld
2125The object file is meant for input to the linker @code{@value{LD}}. It contains
2126assembled program code, information to help @code{@value{LD}} integrate
2127the assembled program into a runnable file, and (optionally) symbolic
2128information for the debugger.
2129
2130@c link above to some info file(s) like the description of a.out.
2131@c don't forget to describe @sc{gnu} info as well as Unix lossage.
2132
2133@node Errors
2134@section Error and Warning Messages
2135
0285c67d
NC
2136@c man begin DESCRIPTION
2137
a349d9dd 2138@cindex error messages
252b5132
RH
2139@cindex warning messages
2140@cindex messages from assembler
a4fb0134 2141@command{@value{AS}} may write warnings and error messages to the standard error
252b5132 2142file (usually your terminal). This should not happen when a compiler
a4fb0134
SC
2143runs @command{@value{AS}} automatically. Warnings report an assumption made so
2144that @command{@value{AS}} could keep assembling a flawed program; errors report a
252b5132
RH
2145grave problem that stops the assembly.
2146
0285c67d
NC
2147@c man end
2148
252b5132
RH
2149@cindex format of warning messages
2150Warning messages have the format
2151
2152@smallexample
2153file_name:@b{NNN}:Warning Message Text
2154@end smallexample
2155
2156@noindent
72e0b254
NC
2157@cindex file names and line numbers, in warnings/errors
2158(where @b{NNN} is a line number). If both a logical file name
2159(@pxref{File,,@code{.file}}) and a logical line number
252b5132
RH
2160@ifset GENERIC
2161(@pxref{Line,,@code{.line}})
2162@end ifset
72e0b254
NC
2163have been given then they will be used, otherwise the file name and line number
2164in the current assembler source file will be used. The message text is
2165intended to be self explanatory (in the grand Unix tradition).
2166
2167Note the file name must be set via the logical version of the @code{.file}
2168directive, not the DWARF2 version of the @code{.file} directive. For example:
2169
2170@smallexample
2171 .file 2 "bar.c"
2172 error_assembler_source
2173 .file "foo.c"
2174 .line 30
2175 error_c_source
2176@end smallexample
2177
2178produces this output:
2179
2180@smallexample
2181 Assembler messages:
2182 asm.s:2: Error: no such instruction: `error_assembler_source'
2183 foo.c:31: Error: no such instruction: `error_c_source'
2184@end smallexample
252b5132
RH
2185
2186@cindex format of error messages
2187Error messages have the format
72e0b254 2188
252b5132
RH
2189@smallexample
2190file_name:@b{NNN}:FATAL:Error Message Text
2191@end smallexample
72e0b254 2192
252b5132
RH
2193The file name and line number are derived as for warning
2194messages. The actual message text may be rather less explanatory
2195because many of them aren't supposed to happen.
2196
2197@node Invoking
2198@chapter Command-Line Options
2199
2200@cindex options, all versions of assembler
2201This chapter describes command-line options available in @emph{all}
96e9638b
BW
2202versions of the @sc{gnu} assembler; see @ref{Machine Dependencies},
2203for options specific
252b5132 2204@ifclear GENERIC
c1253627 2205to the @value{TARGET} target.
252b5132
RH
2206@end ifclear
2207@ifset GENERIC
2208to particular machine architectures.
2209@end ifset
2210
0285c67d
NC
2211@c man begin DESCRIPTION
2212
c1253627 2213If you are invoking @command{@value{AS}} via the @sc{gnu} C compiler,
252b5132
RH
2214you can use the @samp{-Wa} option to pass arguments through to the assembler.
2215The assembler arguments must be separated from each other (and the @samp{-Wa})
2216by commas. For example:
2217
2218@smallexample
2219gcc -c -g -O -Wa,-alh,-L file.c
2220@end smallexample
2221
2222@noindent
2223This passes two options to the assembler: @samp{-alh} (emit a listing to
5f5e16be 2224standard output with high-level and assembly source) and @samp{-L} (retain
252b5132
RH
2225local symbols in the symbol table).
2226
2227Usually you do not need to use this @samp{-Wa} mechanism, since many compiler
2228command-line options are automatically passed to the assembler by the compiler.
2229(You can call the @sc{gnu} compiler driver with the @samp{-v} option to see
2230precisely what options it passes to each compilation pass, including the
2231assembler.)
2232
0285c67d
NC
2233@c man end
2234
252b5132 2235@menu
83f10cb2 2236* a:: -a[cdghlns] enable listings
caa32fe5 2237* alternate:: --alternate enable alternate macro syntax
252b5132
RH
2238* D:: -D for compatibility
2239* f:: -f to work faster
2240* I:: -I for .include search path
2241@ifclear DIFF-TBL-KLUGE
2242* K:: -K for compatibility
2243@end ifclear
2244@ifset DIFF-TBL-KLUGE
2245* K:: -K for difference tables
2246@end ifset
2247
ba83aca1 2248* L:: -L to retain local symbols
c3a27914 2249* listing:: --listing-XXX to configure listing output
252b5132
RH
2250* M:: -M or --mri to assemble in MRI compatibility mode
2251* MD:: --MD for dependency tracking
2edb36e7 2252* no-pad-sections:: --no-pad-sections to stop section padding
252b5132
RH
2253* o:: -o to name the object file
2254* R:: -R to join data and text sections
2255* statistics:: --statistics to see statistics about assembly
2256* traditional-format:: --traditional-format for compatible output
2257* v:: -v to announce version
2bdd6cf5 2258* W:: -W, --no-warn, --warn, --fatal-warnings to control warnings
252b5132
RH
2259* Z:: -Z to make object file even after errors
2260@end menu
2261
2262@node a
83f10cb2 2263@section Enable Listings: @option{-a[cdghlns]}
252b5132
RH
2264
2265@kindex -a
2266@kindex -ac
2267@kindex -ad
83f10cb2 2268@kindex -ag
252b5132
RH
2269@kindex -ah
2270@kindex -al
2271@kindex -an
2272@kindex -as
2273@cindex listings, enabling
2274@cindex assembly listings, enabling
2275
2276These options enable listing output from the assembler. By itself,
2277@samp{-a} requests high-level, assembly, and symbols listing.
2278You can use other letters to select specific options for the list:
2279@samp{-ah} requests a high-level language listing,
2280@samp{-al} requests an output-program assembly listing, and
2281@samp{-as} requests a symbol table listing.
2282High-level listings require that a compiler debugging option like
2283@samp{-g} be used, and that assembly listings (@samp{-al}) be requested
2284also.
2285
83f10cb2
NC
2286Use the @samp{-ag} option to print a first section with general assembly
2287information, like @value{AS} version, switches passed, or time stamp.
2288
252b5132
RH
2289Use the @samp{-ac} option to omit false conditionals from a listing. Any lines
2290which are not assembled because of a false @code{.if} (or @code{.ifdef}, or any
2291other conditional), or a true @code{.if} followed by an @code{.else}, will be
2292omitted from the listing.
2293
2294Use the @samp{-ad} option to omit debugging directives from the
2295listing.
2296
2297Once you have specified one of these options, you can further control
2298listing output and its appearance using the directives @code{.list},
2299@code{.nolist}, @code{.psize}, @code{.eject}, @code{.title}, and
2300@code{.sbttl}.
2301The @samp{-an} option turns off all forms processing.
2302If you do not request listing output with one of the @samp{-a} options, the
2303listing-control directives have no effect.
2304
2305The letters after @samp{-a} may be combined into one option,
2306@emph{e.g.}, @samp{-aln}.
2307
96e9638b
BW
2308Note if the assembler source is coming from the standard input (e.g.,
2309because it
c3a27914
NC
2310is being created by @code{@value{GCC}} and the @samp{-pipe} command line switch
2311is being used) then the listing will not contain any comments or preprocessor
2312directives. This is because the listing code buffers input source lines from
2313stdin only after they have been preprocessed by the assembler. This reduces
2314memory usage and makes the code more efficient.
2315
caa32fe5
NC
2316@node alternate
2317@section @option{--alternate}
2318
2319@kindex --alternate
2320Begin in alternate macro mode, see @ref{Altmacro,,@code{.altmacro}}.
2321
252b5132 2322@node D
a4fb0134 2323@section @option{-D}
252b5132
RH
2324
2325@kindex -D
2326This option has no effect whatsoever, but it is accepted to make it more
2327likely that scripts written for other assemblers also work with
a4fb0134 2328@command{@value{AS}}.
252b5132
RH
2329
2330@node f
a4fb0134 2331@section Work Faster: @option{-f}
252b5132
RH
2332
2333@kindex -f
2334@cindex trusted compiler
a4fb0134 2335@cindex faster processing (@option{-f})
252b5132
RH
2336@samp{-f} should only be used when assembling programs written by a
2337(trusted) compiler. @samp{-f} stops the assembler from doing whitespace
2338and comment preprocessing on
2339the input file(s) before assembling them. @xref{Preprocessing,
2340,Preprocessing}.
2341
2342@quotation
2343@emph{Warning:} if you use @samp{-f} when the files actually need to be
a4fb0134 2344preprocessed (if they contain comments, for example), @command{@value{AS}} does
252b5132
RH
2345not work correctly.
2346@end quotation
2347
2348@node I
c1253627 2349@section @code{.include} Search Path: @option{-I} @var{path}
252b5132
RH
2350
2351@kindex -I @var{path}
2352@cindex paths for @code{.include}
2353@cindex search path for @code{.include}
2354@cindex @code{include} directive search path
2355Use this option to add a @var{path} to the list of directories
a4fb0134
SC
2356@command{@value{AS}} searches for files specified in @code{.include}
2357directives (@pxref{Include,,@code{.include}}). You may use @option{-I} as
252b5132 2358many times as necessary to include a variety of paths. The current
a4fb0134 2359working directory is always searched first; after that, @command{@value{AS}}
252b5132
RH
2360searches any @samp{-I} directories in the same order as they were
2361specified (left to right) on the command line.
2362
2363@node K
a4fb0134 2364@section Difference Tables: @option{-K}
252b5132
RH
2365
2366@kindex -K
2367@ifclear DIFF-TBL-KLUGE
2368On the @value{TARGET} family, this option is allowed, but has no effect. It is
2369permitted for compatibility with the @sc{gnu} assembler on other platforms,
2370where it can be used to warn when the assembler alters the machine code
2371generated for @samp{.word} directives in difference tables. The @value{TARGET}
2372family does not have the addressing limitations that sometimes lead to this
2373alteration on other platforms.
2374@end ifclear
2375
2376@ifset DIFF-TBL-KLUGE
2377@cindex difference tables, warning
2378@cindex warning for altered difference tables
96e9638b
BW
2379@command{@value{AS}} sometimes alters the code emitted for directives of the
2380form @samp{.word @var{sym1}-@var{sym2}}. @xref{Word,,@code{.word}}.
252b5132
RH
2381You can use the @samp{-K} option if you want a warning issued when this
2382is done.
2383@end ifset
2384
2385@node L
ba83aca1 2386@section Include Local Symbols: @option{-L}
252b5132
RH
2387
2388@kindex -L
ba83aca1
BW
2389@cindex local symbols, retaining in output
2390Symbols beginning with system-specific local label prefixes, typically
2391@samp{.L} for ELF systems or @samp{L} for traditional a.out systems, are
2392called @dfn{local symbols}. @xref{Symbol Names}. Normally you do not see
2393such symbols when debugging, because they are intended for the use of
2394programs (like compilers) that compose assembler programs, not for your
2395notice. Normally both @command{@value{AS}} and @code{@value{LD}} discard
2396such symbols, so you do not normally debug with them.
2397
2398This option tells @command{@value{AS}} to retain those local symbols
252b5132 2399in the object file. Usually if you do this you also tell the linker
ba83aca1 2400@code{@value{LD}} to preserve those symbols.
252b5132 2401
c3a27914 2402@node listing
a4fb0134 2403@section Configuring listing output: @option{--listing}
c3a27914
NC
2404
2405The listing feature of the assembler can be enabled via the command line switch
2406@samp{-a} (@pxref{a}). This feature combines the input source file(s) with a
2407hex dump of the corresponding locations in the output object file, and displays
96e9638b
BW
2408them as a listing file. The format of this listing can be controlled by
2409directives inside the assembler source (i.e., @code{.list} (@pxref{List}),
2410@code{.title} (@pxref{Title}), @code{.sbttl} (@pxref{Sbttl}),
2411@code{.psize} (@pxref{Psize}), and
2412@code{.eject} (@pxref{Eject}) and also by the following switches:
c3a27914 2413
a4fb0134 2414@table @gcctabopt
c3a27914
NC
2415@item --listing-lhs-width=@samp{number}
2416@kindex --listing-lhs-width
2417@cindex Width of first line disassembly output
2418Sets the maximum width, in words, of the first line of the hex byte dump. This
2419dump appears on the left hand side of the listing output.
2420
2421@item --listing-lhs-width2=@samp{number}
2422@kindex --listing-lhs-width2
2423@cindex Width of continuation lines of disassembly output
2424Sets the maximum width, in words, of any further lines of the hex byte dump for
8dfa0188 2425a given input source line. If this value is not specified, it defaults to being
c3a27914
NC
2426the same as the value specified for @samp{--listing-lhs-width}. If neither
2427switch is used the default is to one.
2428
2429@item --listing-rhs-width=@samp{number}
2430@kindex --listing-rhs-width
2431@cindex Width of source line output
2432Sets the maximum width, in characters, of the source line that is displayed
2433alongside the hex dump. The default value for this parameter is 100. The
2434source line is displayed on the right hand side of the listing output.
2435
2436@item --listing-cont-lines=@samp{number}
2437@kindex --listing-cont-lines
2438@cindex Maximum number of continuation lines
2439Sets the maximum number of continuation lines of hex dump that will be
2440displayed for a given single line of source input. The default value is 4.
2441@end table
2442
252b5132 2443@node M
a4fb0134 2444@section Assemble in MRI Compatibility Mode: @option{-M}
252b5132
RH
2445
2446@kindex -M
2447@cindex MRI compatibility mode
a4fb0134
SC
2448The @option{-M} or @option{--mri} option selects MRI compatibility mode. This
2449changes the syntax and pseudo-op handling of @command{@value{AS}} to make it
252b5132
RH
2450compatible with the @code{ASM68K} or the @code{ASM960} (depending upon the
2451configured target) assembler from Microtec Research. The exact nature of the
2452MRI syntax will not be documented here; see the MRI manuals for more
2453information. Note in particular that the handling of macros and macro
2454arguments is somewhat different. The purpose of this option is to permit
a4fb0134 2455assembling existing MRI assembler code using @command{@value{AS}}.
252b5132
RH
2456
2457The MRI compatibility is not complete. Certain operations of the MRI assembler
2458depend upon its object file format, and can not be supported using other object
2459file formats. Supporting these would require enhancing each object file format
2460individually. These are:
2461
2462@itemize @bullet
2463@item global symbols in common section
2464
2465The m68k MRI assembler supports common sections which are merged by the linker.
a4fb0134 2466Other object file formats do not support this. @command{@value{AS}} handles
252b5132
RH
2467common sections by treating them as a single common symbol. It permits local
2468symbols to be defined within a common section, but it can not support global
2469symbols, since it has no way to describe them.
2470
2471@item complex relocations
2472
2473The MRI assemblers support relocations against a negated section address, and
2474relocations which combine the start addresses of two or more sections. These
2475are not support by other object file formats.
2476
2477@item @code{END} pseudo-op specifying start address
2478
2479The MRI @code{END} pseudo-op permits the specification of a start address.
2480This is not supported by other object file formats. The start address may
a4fb0134 2481instead be specified using the @option{-e} option to the linker, or in a linker
252b5132
RH
2482script.
2483
2484@item @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops
2485
2486The MRI @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops assign a module
2487name to the output file. This is not supported by other object file formats.
2488
2489@item @code{ORG} pseudo-op
2490
2491The m68k MRI @code{ORG} pseudo-op begins an absolute section at a given
a4fb0134 2492address. This differs from the usual @command{@value{AS}} @code{.org} pseudo-op,
252b5132
RH
2493which changes the location within the current section. Absolute sections are
2494not supported by other object file formats. The address of a section may be
2495assigned within a linker script.
2496@end itemize
2497
2498There are some other features of the MRI assembler which are not supported by
a4fb0134 2499@command{@value{AS}}, typically either because they are difficult or because they
252b5132
RH
2500seem of little consequence. Some of these may be supported in future releases.
2501
2502@itemize @bullet
2503
2504@item EBCDIC strings
2505
2506EBCDIC strings are not supported.
2507
2508@item packed binary coded decimal
2509
2510Packed binary coded decimal is not supported. This means that the @code{DC.P}
2511and @code{DCB.P} pseudo-ops are not supported.
2512
2513@item @code{FEQU} pseudo-op
2514
2515The m68k @code{FEQU} pseudo-op is not supported.
2516
2517@item @code{NOOBJ} pseudo-op
2518
2519The m68k @code{NOOBJ} pseudo-op is not supported.
2520
2521@item @code{OPT} branch control options
2522
2523The m68k @code{OPT} branch control options---@code{B}, @code{BRS}, @code{BRB},
a4fb0134 2524@code{BRL}, and @code{BRW}---are ignored. @command{@value{AS}} automatically
252b5132
RH
2525relaxes all branches, whether forward or backward, to an appropriate size, so
2526these options serve no purpose.
2527
2528@item @code{OPT} list control options
2529
2530The following m68k @code{OPT} list control options are ignored: @code{C},
2531@code{CEX}, @code{CL}, @code{CRE}, @code{E}, @code{G}, @code{I}, @code{M},
2532@code{MEX}, @code{MC}, @code{MD}, @code{X}.
2533
2534@item other @code{OPT} options
2535
2536The following m68k @code{OPT} options are ignored: @code{NEST}, @code{O},
2537@code{OLD}, @code{OP}, @code{P}, @code{PCO}, @code{PCR}, @code{PCS}, @code{R}.
2538
2539@item @code{OPT} @code{D} option is default
2540
2541The m68k @code{OPT} @code{D} option is the default, unlike the MRI assembler.
2542@code{OPT NOD} may be used to turn it off.
2543
2544@item @code{XREF} pseudo-op.
2545
2546The m68k @code{XREF} pseudo-op is ignored.
2547
2548@item @code{.debug} pseudo-op
2549
2550The i960 @code{.debug} pseudo-op is not supported.
2551
2552@item @code{.extended} pseudo-op
2553
2554The i960 @code{.extended} pseudo-op is not supported.
2555
2556@item @code{.list} pseudo-op.
2557
2558The various options of the i960 @code{.list} pseudo-op are not supported.
2559
2560@item @code{.optimize} pseudo-op
2561
2562The i960 @code{.optimize} pseudo-op is not supported.
2563
2564@item @code{.output} pseudo-op
2565
2566The i960 @code{.output} pseudo-op is not supported.
2567
2568@item @code{.setreal} pseudo-op
2569
2570The i960 @code{.setreal} pseudo-op is not supported.
2571
2572@end itemize
2573
2574@node MD
c1253627 2575@section Dependency Tracking: @option{--MD}
252b5132
RH
2576
2577@kindex --MD
2578@cindex dependency tracking
2579@cindex make rules
2580
a4fb0134 2581@command{@value{AS}} can generate a dependency file for the file it creates. This
252b5132
RH
2582file consists of a single rule suitable for @code{make} describing the
2583dependencies of the main source file.
2584
2585The rule is written to the file named in its argument.
2586
2587This feature is used in the automatic updating of makefiles.
2588
2edb36e7
NC
2589@node no-pad-sections
2590@section Output Section Padding
2591@kindex --no-pad-sections
2592@cindex output section padding
2593Normally the assembler will pad the end of each output section up to its
2594alignment boundary. But this can waste space, which can be significant on
2595memory constrained targets. So the @option{--no-pad-sections} option will
2596disable this behaviour.
2597
252b5132 2598@node o
a4fb0134 2599@section Name the Object File: @option{-o}
252b5132
RH
2600
2601@kindex -o
2602@cindex naming object file
2603@cindex object file name
a4fb0134 2604There is always one object file output when you run @command{@value{AS}}. By
252b5132
RH
2605default it has the name
2606@ifset GENERIC
2607@ifset I960
2608@file{a.out} (or @file{b.out}, for Intel 960 targets only).
2609@end ifset
2610@ifclear I960
2611@file{a.out}.
2612@end ifclear
2613@end ifset
2614@ifclear GENERIC
2615@ifset I960
2616@file{b.out}.
2617@end ifset
2618@ifclear I960
2619@file{a.out}.
2620@end ifclear
2621@end ifclear
2622You use this option (which takes exactly one filename) to give the
2623object file a different name.
2624
a4fb0134 2625Whatever the object file is called, @command{@value{AS}} overwrites any
252b5132
RH
2626existing file of the same name.
2627
2628@node R
a4fb0134 2629@section Join Data and Text Sections: @option{-R}
252b5132
RH
2630
2631@kindex -R
2632@cindex data and text sections, joining
2633@cindex text and data sections, joining
2634@cindex joining text and data sections
2635@cindex merging text and data sections
a4fb0134 2636@option{-R} tells @command{@value{AS}} to write the object file as if all
252b5132
RH
2637data-section data lives in the text section. This is only done at
2638the very last moment: your binary data are the same, but data
2639section parts are relocated differently. The data section part of
2640your object file is zero bytes long because all its bytes are
2641appended to the text section. (@xref{Sections,,Sections and Relocation}.)
2642
a4fb0134 2643When you specify @option{-R} it would be possible to generate shorter
252b5132
RH
2644address displacements (because we do not have to cross between text and
2645data section). We refrain from doing this simply for compatibility with
a4fb0134 2646older versions of @command{@value{AS}}. In future, @option{-R} may work this way.
252b5132 2647
c1253627
NC
2648@ifset COFF-ELF
2649When @command{@value{AS}} is configured for COFF or ELF output,
252b5132
RH
2650this option is only useful if you use sections named @samp{.text} and
2651@samp{.data}.
2652@end ifset
2653
2654@ifset HPPA
a4fb0134
SC
2655@option{-R} is not supported for any of the HPPA targets. Using
2656@option{-R} generates a warning from @command{@value{AS}}.
252b5132
RH
2657@end ifset
2658
2659@node statistics
a4fb0134 2660@section Display Assembly Statistics: @option{--statistics}
252b5132
RH
2661
2662@kindex --statistics
2663@cindex statistics, about assembly
2664@cindex time, total for assembly
2665@cindex space used, maximum for assembly
2666Use @samp{--statistics} to display two statistics about the resources used by
a4fb0134 2667@command{@value{AS}}: the maximum amount of space allocated during the assembly
252b5132
RH
2668(in bytes), and the total execution time taken for the assembly (in @sc{cpu}
2669seconds).
2670
2671@node traditional-format
c1253627 2672@section Compatible Output: @option{--traditional-format}
252b5132
RH
2673
2674@kindex --traditional-format
a4fb0134 2675For some targets, the output of @command{@value{AS}} is different in some ways
252b5132 2676from the output of some existing assembler. This switch requests
a4fb0134 2677@command{@value{AS}} to use the traditional format instead.
252b5132
RH
2678
2679For example, it disables the exception frame optimizations which
a4fb0134 2680@command{@value{AS}} normally does by default on @code{@value{GCC}} output.
252b5132
RH
2681
2682@node v
a4fb0134 2683@section Announce Version: @option{-v}
252b5132
RH
2684
2685@kindex -v
2686@kindex -version
2687@cindex assembler version
2688@cindex version of assembler
2689You can find out what version of as is running by including the
2690option @samp{-v} (which you can also spell as @samp{-version}) on the
2691command line.
2692
2693@node W
a4fb0134 2694@section Control Warnings: @option{-W}, @option{--warn}, @option{--no-warn}, @option{--fatal-warnings}
252b5132 2695
a4fb0134 2696@command{@value{AS}} should never give a warning or error message when
252b5132 2697assembling compiler output. But programs written by people often
a4fb0134 2698cause @command{@value{AS}} to give a warning that a particular assumption was
252b5132 2699made. All such warnings are directed to the standard error file.
2bdd6cf5 2700
c1253627
NC
2701@kindex -W
2702@kindex --no-warn
2bdd6cf5
GK
2703@cindex suppressing warnings
2704@cindex warnings, suppressing
a4fb0134 2705If you use the @option{-W} and @option{--no-warn} options, no warnings are issued.
2bdd6cf5 2706This only affects the warning messages: it does not change any particular of
a4fb0134 2707how @command{@value{AS}} assembles your file. Errors, which stop the assembly,
2bdd6cf5
GK
2708are still reported.
2709
c1253627 2710@kindex --fatal-warnings
2bdd6cf5
GK
2711@cindex errors, caused by warnings
2712@cindex warnings, causing error
a4fb0134 2713If you use the @option{--fatal-warnings} option, @command{@value{AS}} considers
2bdd6cf5
GK
2714files that generate warnings to be in error.
2715
c1253627 2716@kindex --warn
2bdd6cf5 2717@cindex warnings, switching on
a4fb0134 2718You can switch these options off again by specifying @option{--warn}, which
2bdd6cf5 2719causes warnings to be output as usual.
252b5132
RH
2720
2721@node Z
a4fb0134 2722@section Generate Object File in Spite of Errors: @option{-Z}
252b5132
RH
2723@cindex object file, after errors
2724@cindex errors, continuing after
a4fb0134 2725After an error message, @command{@value{AS}} normally produces no output. If for
252b5132 2726some reason you are interested in object file output even after
a4fb0134
SC
2727@command{@value{AS}} gives an error message on your program, use the @samp{-Z}
2728option. If there are any errors, @command{@value{AS}} continues anyways, and
252b5132
RH
2729writes an object file after a final warning message of the form @samp{@var{n}
2730errors, @var{m} warnings, generating bad object file.}
2731
2732@node Syntax
2733@chapter Syntax
2734
2735@cindex machine-independent syntax
2736@cindex syntax, machine-independent
2737This chapter describes the machine-independent syntax allowed in a
a4fb0134 2738source file. @command{@value{AS}} syntax is similar to what many other
252b5132
RH
2739assemblers use; it is inspired by the BSD 4.2
2740@ifclear VAX
2741assembler.
2742@end ifclear
2743@ifset VAX
a4fb0134 2744assembler, except that @command{@value{AS}} does not assemble Vax bit-fields.
252b5132
RH
2745@end ifset
2746
2747@menu
7c31ae13 2748* Preprocessing:: Preprocessing
252b5132
RH
2749* Whitespace:: Whitespace
2750* Comments:: Comments
2751* Symbol Intro:: Symbols
2752* Statements:: Statements
2753* Constants:: Constants
2754@end menu
2755
2756@node Preprocessing
2757@section Preprocessing
2758
2759@cindex preprocessing
a4fb0134 2760The @command{@value{AS}} internal preprocessor:
252b5132
RH
2761@itemize @bullet
2762@cindex whitespace, removed by preprocessor
2763@item
2764adjusts and removes extra whitespace. It leaves one space or tab before
2765the keywords on a line, and turns any other whitespace on the line into
2766a single space.
2767
2768@cindex comments, removed by preprocessor
2769@item
2770removes all comments, replacing them with a single space, or an
2771appropriate number of newlines.
2772
2773@cindex constants, converted by preprocessor
2774@item
2775converts character constants into the appropriate numeric values.
2776@end itemize
2777
2778It does not do macro processing, include file handling, or
2779anything else you may get from your C compiler's preprocessor. You can
2780do include file processing with the @code{.include} directive
2781(@pxref{Include,,@code{.include}}). You can use the @sc{gnu} C compiler driver
c1253627 2782to get other ``CPP'' style preprocessing by giving the input file a
96e9638b 2783@samp{.S} suffix. @xref{Overall Options, ,Options Controlling the Kind of
2edb36e7 2784Output, gcc info, Using GNU CC}.
252b5132
RH
2785
2786Excess whitespace, comments, and character constants
2787cannot be used in the portions of the input text that are not
2788preprocessed.
2789
2790@cindex turning preprocessing on and off
2791@cindex preprocessing, turning on and off
2792@kindex #NO_APP
2793@kindex #APP
2794If the first line of an input file is @code{#NO_APP} or if you use the
2795@samp{-f} option, whitespace and comments are not removed from the input file.
2796Within an input file, you can ask for whitespace and comment removal in
2797specific portions of the by putting a line that says @code{#APP} before the
2798text that may contain whitespace or comments, and putting a line that says
2799@code{#NO_APP} after this text. This feature is mainly intend to support
2800@code{asm} statements in compilers whose output is otherwise free of comments
2801and whitespace.
2802
2803@node Whitespace
2804@section Whitespace
2805
2806@cindex whitespace
2807@dfn{Whitespace} is one or more blanks or tabs, in any order.
2808Whitespace is used to separate symbols, and to make programs neater for
2809people to read. Unless within character constants
2810(@pxref{Characters,,Character Constants}), any whitespace means the same
2811as exactly one space.
2812
2813@node Comments
2814@section Comments
2815
2816@cindex comments
a4fb0134 2817There are two ways of rendering comments to @command{@value{AS}}. In both
252b5132
RH
2818cases the comment is equivalent to one space.
2819
2820Anything from @samp{/*} through the next @samp{*/} is a comment.
2821This means you may not nest these comments.
2822
2823@smallexample
2824/*
2825 The only way to include a newline ('\n') in a comment
2826 is to use this sort of comment.
2827*/
2828
2829/* This sort of comment does not nest. */
2830@end smallexample
2831
2832@cindex line comment character
7c31ae13
NC
2833Anything from a @dfn{line comment} character up to the next newline is
2834considered a comment and is ignored. The line comment character is target
2835specific, and some targets multiple comment characters. Some targets also have
2836line comment characters that only work if they are the first character on a
2837line. Some targets use a sequence of two characters to introduce a line
2838comment. Some targets can also change their line comment characters depending
2839upon command line options that have been used. For more details see the
2840@emph{Syntax} section in the documentation for individual targets.
2841
2842If the line comment character is the hash sign (@samp{#}) then it still has the
2843special ability to enable and disable preprocessing (@pxref{Preprocessing}) and
2844to specify logical line numbers:
252b5132
RH
2845
2846@kindex #
2847@cindex lines starting with @code{#}
2848@cindex logical line numbers
2849To be compatible with past assemblers, lines that begin with @samp{#} have a
2850special interpretation. Following the @samp{#} should be an absolute
2851expression (@pxref{Expressions}): the logical line number of the @emph{next}
96e9638b 2852line. Then a string (@pxref{Strings, ,Strings}) is allowed: if present it is a
252b5132
RH
2853new logical file name. The rest of the line, if any, should be whitespace.
2854
2855If the first non-whitespace characters on the line are not numeric,
2856the line is ignored. (Just like a comment.)
2857
2858@smallexample
2859 # This is an ordinary comment.
2860# 42-6 "new_file_name" # New logical file name
2861 # This is logical line # 36.
2862@end smallexample
2863This feature is deprecated, and may disappear from future versions
a4fb0134 2864of @command{@value{AS}}.
252b5132
RH
2865
2866@node Symbol Intro
2867@section Symbols
2868
2869@cindex characters used in symbols
2870@ifclear SPECIAL-SYMS
2871A @dfn{symbol} is one or more characters chosen from the set of all
2872letters (both upper and lower case), digits and the three characters
2873@samp{_.$}.
2874@end ifclear
2875@ifset SPECIAL-SYMS
2876@ifclear GENERIC
2877@ifset H8
2878A @dfn{symbol} is one or more characters chosen from the set of all
2879letters (both upper and lower case), digits and the three characters
2880@samp{._$}. (Save that, on the H8/300 only, you may not use @samp{$} in
2881symbol names.)
2882@end ifset
2883@end ifclear
2884@end ifset
2885@ifset GENERIC
2886On most machines, you can also use @code{$} in symbol names; exceptions
2887are noted in @ref{Machine Dependencies}.
2888@end ifset
2889No symbol may begin with a digit. Case is significant.
d02603dc 2890There is no length limit; all characters are significant. Multibyte characters
7bfd842d
NC
2891are supported. Symbols are delimited by characters not in that set, or by the
2892beginning of a file (since the source program must end with a newline, the end
2893of a file is not a possible symbol delimiter). @xref{Symbols}.
d02603dc
NC
2894
2895Symbol names may also be enclosed in double quote @code{"} characters. In such
2896cases any characters are allowed, except for the NUL character. If a double
2897quote character is to be included in the symbol name it must be preceeded by a
2898backslash @code{\} character.
252b5132
RH
2899@cindex length of symbols
2900
2901@node Statements
2902@section Statements
2903
2904@cindex statements, structure of
2905@cindex line separator character
2906@cindex statement separator character
7c31ae13
NC
2907
2908A @dfn{statement} ends at a newline character (@samp{\n}) or a
2909@dfn{line separator character}. The line separator character is target
2910specific and described in the @emph{Syntax} section of each
2911target's documentation. Not all targets support a line separator character.
2912The newline or line separator character is considered to be part of the
2913preceding statement. Newlines and separators within character constants are an
252b5132 2914exception: they do not end statements.
252b5132
RH
2915
2916@cindex newline, required at file end
2917@cindex EOF, newline must precede
2918It is an error to end any statement with end-of-file: the last
2919character of any input file should be a newline.@refill
2920
2921An empty statement is allowed, and may include whitespace. It is ignored.
2922
2923@cindex instructions and directives
2924@cindex directives and instructions
2925@c "key symbol" is not used elsewhere in the document; seems pedantic to
2926@c @defn{} it in that case, as was done previously... doc@cygnus.com,
2927@c 13feb91.
2928A statement begins with zero or more labels, optionally followed by a
2929key symbol which determines what kind of statement it is. The key
2930symbol determines the syntax of the rest of the statement. If the
2931symbol begins with a dot @samp{.} then the statement is an assembler
2932directive: typically valid for any computer. If the symbol begins with
2933a letter the statement is an assembly language @dfn{instruction}: it
2934assembles into a machine language instruction.
2935@ifset GENERIC
a4fb0134 2936Different versions of @command{@value{AS}} for different computers
252b5132
RH
2937recognize different instructions. In fact, the same symbol may
2938represent a different instruction in a different computer's assembly
2939language.@refill
2940@end ifset
2941
2942@cindex @code{:} (label)
2943@cindex label (@code{:})
2944A label is a symbol immediately followed by a colon (@code{:}).
2945Whitespace before a label or after a colon is permitted, but you may not
2946have whitespace between a label's symbol and its colon. @xref{Labels}.
2947
2948@ifset HPPA
01642c12 2949For HPPA targets, labels need not be immediately followed by a colon, but
252b5132
RH
2950the definition of a label must begin in column zero. This also implies that
2951only one label may be defined on each line.
2952@end ifset
2953
2954@smallexample
2955label: .directive followed by something
2956another_label: # This is an empty statement.
2957 instruction operand_1, operand_2, @dots{}
2958@end smallexample
2959
2960@node Constants
2961@section Constants
2962
2963@cindex constants
2964A constant is a number, written so that its value is known by
2965inspection, without knowing any context. Like this:
2966@smallexample
2967@group
2968.byte 74, 0112, 092, 0x4A, 0X4a, 'J, '\J # All the same value.
2969.ascii "Ring the bell\7" # A string constant.
2970.octa 0x123456789abcdef0123456789ABCDEF0 # A bignum.
2971.float 0f-314159265358979323846264338327\
297295028841971.693993751E-40 # - pi, a flonum.
2973@end group
2974@end smallexample
2975
2976@menu
2977* Characters:: Character Constants
2978* Numbers:: Number Constants
2979@end menu
2980
2981@node Characters
2982@subsection Character Constants
2983
2984@cindex character constants
2985@cindex constants, character
2986There are two kinds of character constants. A @dfn{character} stands
2987for one character in one byte and its value may be used in
2988numeric expressions. String constants (properly called string
2989@emph{literals}) are potentially many bytes and their values may not be
2990used in arithmetic expressions.
2991
2992@menu
2993* Strings:: Strings
2994* Chars:: Characters
2995@end menu
2996
2997@node Strings
2998@subsubsection Strings
2999
3000@cindex string constants
3001@cindex constants, string
3002A @dfn{string} is written between double-quotes. It may contain
3003double-quotes or null characters. The way to get special characters
3004into a string is to @dfn{escape} these characters: precede them with
3005a backslash @samp{\} character. For example @samp{\\} represents
3006one backslash: the first @code{\} is an escape which tells
a4fb0134
SC
3007@command{@value{AS}} to interpret the second character literally as a backslash
3008(which prevents @command{@value{AS}} from recognizing the second @code{\} as an
252b5132
RH
3009escape character). The complete list of escapes follows.
3010
3011@cindex escape codes, character
3012@cindex character escape codes
361fa3a4
NC
3013@c NOTE: Cindex entries must not start with a backlash character.
3014@c NOTE: This confuses the pdf2texi script when it is creating the
3015@c NOTE: index based upon the first character and so it generates:
3016@c NOTE: \initial {\\}
3017@c NOTE: which then results in the error message:
3018@c NOTE: Argument of \\ has an extra }.
3019@c NOTE: So in the index entries below a space character has been
3020@c NOTE: prepended to avoid this problem.
252b5132
RH
3021@table @kbd
3022@c @item \a
3023@c Mnemonic for ACKnowledge; for ASCII this is octal code 007.
3024@c
361fa3a4 3025@cindex @code{ \b} (backspace character)
252b5132
RH
3026@cindex backspace (@code{\b})
3027@item \b
3028Mnemonic for backspace; for ASCII this is octal code 010.
3029
3030@c @item \e
3031@c Mnemonic for EOText; for ASCII this is octal code 004.
3032@c
361fa3a4 3033@cindex @code{ \f} (formfeed character)
252b5132 3034@cindex formfeed (@code{\f})
361fa3a4 3035@item backslash-f
252b5132
RH
3036Mnemonic for FormFeed; for ASCII this is octal code 014.
3037
361fa3a4 3038@cindex @code{ \n} (newline character)
252b5132
RH
3039@cindex newline (@code{\n})
3040@item \n
3041Mnemonic for newline; for ASCII this is octal code 012.
3042
3043@c @item \p
3044@c Mnemonic for prefix; for ASCII this is octal code 033, usually known as @code{escape}.
3045@c
361fa3a4
NC
3046@cindex @code{ \r} (carriage return character)
3047@cindex carriage return (@code{backslash-r})
252b5132
RH
3048@item \r
3049Mnemonic for carriage-Return; for ASCII this is octal code 015.
3050
3051@c @item \s
3052@c Mnemonic for space; for ASCII this is octal code 040. Included for compliance with
3053@c other assemblers.
3054@c
361fa3a4 3055@cindex @code{ \t} (tab)
252b5132
RH
3056@cindex tab (@code{\t})
3057@item \t
3058Mnemonic for horizontal Tab; for ASCII this is octal code 011.
3059
3060@c @item \v
3061@c Mnemonic for Vertical tab; for ASCII this is octal code 013.
3062@c @item \x @var{digit} @var{digit} @var{digit}
3063@c A hexadecimal character code. The numeric code is 3 hexadecimal digits.
3064@c
361fa3a4 3065@cindex @code{ \@var{ddd}} (octal character code)
252b5132
RH
3066@cindex octal character code (@code{\@var{ddd}})
3067@item \ @var{digit} @var{digit} @var{digit}
3068An octal character code. The numeric code is 3 octal digits.
3069For compatibility with other Unix systems, 8 and 9 are accepted as digits:
3070for example, @code{\008} has the value 010, and @code{\009} the value 011.
3071
361fa3a4 3072@cindex @code{ \@var{xd...}} (hex character code)
252b5132
RH
3073@cindex hex character code (@code{\@var{xd...}})
3074@item \@code{x} @var{hex-digits...}
3075A hex character code. All trailing hex digits are combined. Either upper or
3076lower case @code{x} works.
3077
361fa3a4 3078@cindex @code{ \\} (@samp{\} character)
252b5132
RH
3079@cindex backslash (@code{\\})
3080@item \\
3081Represents one @samp{\} character.
3082
3083@c @item \'
3084@c Represents one @samp{'} (accent acute) character.
3085@c This is needed in single character literals
3086@c (@xref{Characters,,Character Constants}.) to represent
3087@c a @samp{'}.
3088@c
361fa3a4 3089@cindex @code{ \"} (doublequote character)
252b5132
RH
3090@cindex doublequote (@code{\"})
3091@item \"
3092Represents one @samp{"} character. Needed in strings to represent
3093this character, because an unescaped @samp{"} would end the string.
3094
3095@item \ @var{anything-else}
3096Any other character when escaped by @kbd{\} gives a warning, but
3097assembles as if the @samp{\} was not present. The idea is that if
3098you used an escape sequence you clearly didn't want the literal
a4fb0134
SC
3099interpretation of the following character. However @command{@value{AS}} has no
3100other interpretation, so @command{@value{AS}} knows it is giving you the wrong
252b5132
RH
3101code and warns you of the fact.
3102@end table
3103
3104Which characters are escapable, and what those escapes represent,
3105varies widely among assemblers. The current set is what we think
3106the BSD 4.2 assembler recognizes, and is a subset of what most C
3107compilers recognize. If you are in doubt, do not use an escape
3108sequence.
3109
3110@node Chars
3111@subsubsection Characters
3112
3113@cindex single character constant
3114@cindex character, single
3115@cindex constant, single character
9962fe29
AM
3116A single character may be written as a single quote immediately followed by
3117that character. Some backslash escapes apply to characters, @code{\b},
3118@code{\f}, @code{\n}, @code{\r}, @code{\t}, and @code{\"} with the same meaning
3119as for strings, plus @code{\'} for a single quote. So if you want to write the
3120character backslash, you must write @kbd{'\\} where the first @code{\} escapes
3121the second @code{\}. As you can see, the quote is an acute accent, not a grave
3122accent. A newline
252b5132
RH
3123@ifclear GENERIC
3124@ifclear abnormal-separator
3125(or semicolon @samp{;})
3126@end ifclear
3127@ifset abnormal-separator
252b5132
RH
3128@ifset H8
3129(or dollar sign @samp{$}, for the H8/300; or semicolon @samp{;} for the
7be1c489 3130Renesas SH)
252b5132
RH
3131@end ifset
3132@end ifset
3133@end ifclear
3134immediately following an acute accent is taken as a literal character
3135and does not count as the end of a statement. The value of a character
3136constant in a numeric expression is the machine's byte-wide code for
a4fb0134 3137that character. @command{@value{AS}} assumes your character code is ASCII:
252b5132
RH
3138@kbd{'A} means 65, @kbd{'B} means 66, and so on. @refill
3139
3140@node Numbers
3141@subsection Number Constants
3142
3143@cindex constants, number
3144@cindex number constants
a4fb0134 3145@command{@value{AS}} distinguishes three kinds of numbers according to how they
252b5132
RH
3146are stored in the target machine. @emph{Integers} are numbers that
3147would fit into an @code{int} in the C language. @emph{Bignums} are
3148integers, but they are stored in more than 32 bits. @emph{Flonums}
3149are floating point numbers, described below.
3150
3151@menu
3152* Integers:: Integers
3153* Bignums:: Bignums
3154* Flonums:: Flonums
3155@ifclear GENERIC
3156@ifset I960
3157* Bit Fields:: Bit Fields
3158@end ifset
3159@end ifclear
3160@end menu
3161
3162@node Integers
3163@subsubsection Integers
3164@cindex integers
3165@cindex constants, integer
3166
3167@cindex binary integers
3168@cindex integers, binary
3169A binary integer is @samp{0b} or @samp{0B} followed by zero or more of
3170the binary digits @samp{01}.
3171
3172@cindex octal integers
3173@cindex integers, octal
3174An octal integer is @samp{0} followed by zero or more of the octal
3175digits (@samp{01234567}).
3176
3177@cindex decimal integers
3178@cindex integers, decimal
3179A decimal integer starts with a non-zero digit followed by zero or
3180more digits (@samp{0123456789}).
3181
3182@cindex hexadecimal integers
3183@cindex integers, hexadecimal
3184A hexadecimal integer is @samp{0x} or @samp{0X} followed by one or
3185more hexadecimal digits chosen from @samp{0123456789abcdefABCDEF}.
3186
3187Integers have the usual values. To denote a negative integer, use
3188the prefix operator @samp{-} discussed under expressions
3189(@pxref{Prefix Ops,,Prefix Operators}).
3190
3191@node Bignums
3192@subsubsection Bignums
3193
3194@cindex bignums
3195@cindex constants, bignum
3196A @dfn{bignum} has the same syntax and semantics as an integer
3197except that the number (or its negative) takes more than 32 bits to
3198represent in binary. The distinction is made because in some places
3199integers are permitted while bignums are not.
3200
3201@node Flonums
3202@subsubsection Flonums
3203@cindex flonums
3204@cindex floating point numbers
3205@cindex constants, floating point
3206
3207@cindex precision, floating point
3208A @dfn{flonum} represents a floating point number. The translation is
3209indirect: a decimal floating point number from the text is converted by
a4fb0134 3210@command{@value{AS}} to a generic binary floating point number of more than
252b5132
RH
3211sufficient precision. This generic floating point number is converted
3212to a particular computer's floating point format (or formats) by a
a4fb0134 3213portion of @command{@value{AS}} specialized to that computer.
252b5132
RH
3214
3215A flonum is written by writing (in order)
3216@itemize @bullet
3217@item
3218The digit @samp{0}.
3219@ifset HPPA
3220(@samp{0} is optional on the HPPA.)
3221@end ifset
3222
3223@item
a4fb0134 3224A letter, to tell @command{@value{AS}} the rest of the number is a flonum.
252b5132
RH
3225@ifset GENERIC
3226@kbd{e} is recommended. Case is not important.
3227@ignore
3228@c FIXME: verify if flonum syntax really this vague for most cases
3229(Any otherwise illegal letter works here, but that might be changed. Vax BSD
32304.2 assembler seems to allow any of @samp{defghDEFGH}.)
3231@end ignore
3232
7be1c489 3233On the H8/300, Renesas / SuperH SH,
252b5132
RH
3234and AMD 29K architectures, the letter must be
3235one of the letters @samp{DFPRSX} (in upper or lower case).
3236
3237On the ARC, the letter must be one of the letters @samp{DFRS}
3238(in upper or lower case).
3239
3240On the Intel 960 architecture, the letter must be
3241one of the letters @samp{DFT} (in upper or lower case).
3242
3243On the HPPA architecture, the letter must be @samp{E} (upper case only).
3244@end ifset
3245@ifclear GENERIC
252b5132
RH
3246@ifset ARC
3247One of the letters @samp{DFRS} (in upper or lower case).
3248@end ifset
3249@ifset H8
3250One of the letters @samp{DFPRSX} (in upper or lower case).
3251@end ifset
3252@ifset HPPA
3253The letter @samp{E} (upper case only).
3254@end ifset
3255@ifset I960
3256One of the letters @samp{DFT} (in upper or lower case).
3257@end ifset
3258@end ifclear
3259
3260@item
3261An optional sign: either @samp{+} or @samp{-}.
3262
3263@item
3264An optional @dfn{integer part}: zero or more decimal digits.
3265
3266@item
3267An optional @dfn{fractional part}: @samp{.} followed by zero
3268or more decimal digits.
3269
3270@item
3271An optional exponent, consisting of:
3272
3273@itemize @bullet
3274@item
3275An @samp{E} or @samp{e}.
3276@c I can't find a config where "EXP_CHARS" is other than 'eE', but in
3277@c principle this can perfectly well be different on different targets.
3278@item
3279Optional sign: either @samp{+} or @samp{-}.
3280@item
3281One or more decimal digits.
3282@end itemize
3283
3284@end itemize
3285
3286At least one of the integer part or the fractional part must be
3287present. The floating point number has the usual base-10 value.
3288
a4fb0134 3289@command{@value{AS}} does all processing using integers. Flonums are computed
252b5132 3290independently of any floating point hardware in the computer running
a4fb0134 3291@command{@value{AS}}.
252b5132
RH
3292
3293@ifclear GENERIC
3294@ifset I960
3295@c Bit fields are written as a general facility but are also controlled
3296@c by a conditional-compilation flag---which is as of now (21mar91)
3297@c turned on only by the i960 config of GAS.
3298@node Bit Fields
3299@subsubsection Bit Fields
3300
3301@cindex bit fields
3302@cindex constants, bit field
3303You can also define numeric constants as @dfn{bit fields}.
b45619c0 3304Specify two numbers separated by a colon---
252b5132
RH
3305@example
3306@var{mask}:@var{value}
3307@end example
3308@noindent
a4fb0134 3309@command{@value{AS}} applies a bitwise @sc{and} between @var{mask} and
252b5132
RH
3310@var{value}.
3311
3312The resulting number is then packed
3313@ifset GENERIC
3314@c this conditional paren in case bit fields turned on elsewhere than 960
3315(in host-dependent byte order)
3316@end ifset
3317into a field whose width depends on which assembler directive has the
3318bit-field as its argument. Overflow (a result from the bitwise and
3319requiring more binary digits to represent) is not an error; instead,
3320more constants are generated, of the specified width, beginning with the
3321least significant digits.@refill
3322
3323The directives @code{.byte}, @code{.hword}, @code{.int}, @code{.long},
3324@code{.short}, and @code{.word} accept bit-field arguments.
3325@end ifset
3326@end ifclear
3327
3328@node Sections
3329@chapter Sections and Relocation
3330@cindex sections
3331@cindex relocation
3332
3333@menu
3334* Secs Background:: Background
3335* Ld Sections:: Linker Sections
3336* As Sections:: Assembler Internal Sections
3337* Sub-Sections:: Sub-Sections
3338* bss:: bss Section
3339@end menu
3340
3341@node Secs Background
3342@section Background
3343
3344Roughly, a section is a range of addresses, with no gaps; all data
3345``in'' those addresses is treated the same for some particular purpose.
3346For example there may be a ``read only'' section.
3347
3348@cindex linker, and assembler
3349@cindex assembler, and linker
3350The linker @code{@value{LD}} reads many object files (partial programs) and
a4fb0134 3351combines their contents to form a runnable program. When @command{@value{AS}}
252b5132
RH
3352emits an object file, the partial program is assumed to start at address 0.
3353@code{@value{LD}} assigns the final addresses for the partial program, so that
3354different partial programs do not overlap. This is actually an
a4fb0134 3355oversimplification, but it suffices to explain how @command{@value{AS}} uses
252b5132
RH
3356sections.
3357
3358@code{@value{LD}} moves blocks of bytes of your program to their run-time
3359addresses. These blocks slide to their run-time addresses as rigid
3360units; their length does not change and neither does the order of bytes
3361within them. Such a rigid unit is called a @emph{section}. Assigning
3362run-time addresses to sections is called @dfn{relocation}. It includes
3363the task of adjusting mentions of object-file addresses so they refer to
3364the proper run-time addresses.
3365@ifset H8
7be1c489 3366For the H8/300, and for the Renesas / SuperH SH,
a4fb0134 3367@command{@value{AS}} pads sections if needed to
252b5132
RH
3368ensure they end on a word (sixteen bit) boundary.
3369@end ifset
3370
3371@cindex standard assembler sections
a4fb0134 3372An object file written by @command{@value{AS}} has at least three sections, any
252b5132
RH
3373of which may be empty. These are named @dfn{text}, @dfn{data} and
3374@dfn{bss} sections.
3375
c1253627 3376@ifset COFF-ELF
252b5132 3377@ifset GENERIC
c1253627 3378When it generates COFF or ELF output,
252b5132 3379@end ifset
a4fb0134 3380@command{@value{AS}} can also generate whatever other named sections you specify
252b5132
RH
3381using the @samp{.section} directive (@pxref{Section,,@code{.section}}).
3382If you do not use any directives that place output in the @samp{.text}
3383or @samp{.data} sections, these sections still exist, but are empty.
3384@end ifset
3385
3386@ifset HPPA
3387@ifset GENERIC
a4fb0134 3388When @command{@value{AS}} generates SOM or ELF output for the HPPA,
252b5132 3389@end ifset
a4fb0134 3390@command{@value{AS}} can also generate whatever other named sections you
252b5132
RH
3391specify using the @samp{.space} and @samp{.subspace} directives. See
3392@cite{HP9000 Series 800 Assembly Language Reference Manual}
3393(HP 92432-90001) for details on the @samp{.space} and @samp{.subspace}
3394assembler directives.
3395
3396@ifset SOM
a4fb0134 3397Additionally, @command{@value{AS}} uses different names for the standard
252b5132
RH
3398text, data, and bss sections when generating SOM output. Program text
3399is placed into the @samp{$CODE$} section, data into @samp{$DATA$}, and
3400BSS into @samp{$BSS$}.
3401@end ifset
3402@end ifset
3403
3404Within the object file, the text section starts at address @code{0}, the
3405data section follows, and the bss section follows the data section.
3406
3407@ifset HPPA
3408When generating either SOM or ELF output files on the HPPA, the text
3409section starts at address @code{0}, the data section at address
3410@code{0x4000000}, and the bss section follows the data section.
3411@end ifset
3412
3413To let @code{@value{LD}} know which data changes when the sections are
a4fb0134 3414relocated, and how to change that data, @command{@value{AS}} also writes to the
252b5132
RH
3415object file details of the relocation needed. To perform relocation
3416@code{@value{LD}} must know, each time an address in the object
3417file is mentioned:
3418@itemize @bullet
3419@item
3420Where in the object file is the beginning of this reference to
3421an address?
3422@item
3423How long (in bytes) is this reference?
3424@item
3425Which section does the address refer to? What is the numeric value of
3426@display
3427(@var{address}) @minus{} (@var{start-address of section})?
3428@end display
3429@item
3430Is the reference to an address ``Program-Counter relative''?
3431@end itemize
3432
3433@cindex addresses, format of
3434@cindex section-relative addressing
a4fb0134 3435In fact, every address @command{@value{AS}} ever uses is expressed as
252b5132
RH
3436@display
3437(@var{section}) + (@var{offset into section})
3438@end display
3439@noindent
a4fb0134 3440Further, most expressions @command{@value{AS}} computes have this section-relative
252b5132
RH
3441nature.
3442@ifset SOM
3443(For some object formats, such as SOM for the HPPA, some expressions are
3444symbol-relative instead.)
3445@end ifset
3446
3447In this manual we use the notation @{@var{secname} @var{N}@} to mean ``offset
3448@var{N} into section @var{secname}.''
3449
3450Apart from text, data and bss sections you need to know about the
3451@dfn{absolute} section. When @code{@value{LD}} mixes partial programs,
3452addresses in the absolute section remain unchanged. For example, address
3453@code{@{absolute 0@}} is ``relocated'' to run-time address 0 by
3454@code{@value{LD}}. Although the linker never arranges two partial programs'
3455data sections with overlapping addresses after linking, @emph{by definition}
3456their absolute sections must overlap. Address @code{@{absolute@ 239@}} in one
3457part of a program is always the same address when the program is running as
3458address @code{@{absolute@ 239@}} in any other part of the program.
3459
3460The idea of sections is extended to the @dfn{undefined} section. Any
3461address whose section is unknown at assembly time is by definition
3462rendered @{undefined @var{U}@}---where @var{U} is filled in later.
3463Since numbers are always defined, the only way to generate an undefined
3464address is to mention an undefined symbol. A reference to a named
3465common block would be such a symbol: its value is unknown at assembly
3466time so it has section @emph{undefined}.
3467
3468By analogy the word @emph{section} is used to describe groups of sections in
3469the linked program. @code{@value{LD}} puts all partial programs' text
3470sections in contiguous addresses in the linked program. It is
3471customary to refer to the @emph{text section} of a program, meaning all
3472the addresses of all partial programs' text sections. Likewise for
3473data and bss sections.
3474
3475Some sections are manipulated by @code{@value{LD}}; others are invented for
a4fb0134 3476use of @command{@value{AS}} and have no meaning except during assembly.
252b5132
RH
3477
3478@node Ld Sections
3479@section Linker Sections
3480@code{@value{LD}} deals with just four kinds of sections, summarized below.
3481
3482@table @strong
3483
c1253627 3484@ifset COFF-ELF
252b5132
RH
3485@cindex named sections
3486@cindex sections, named
3487@item named sections
3488@end ifset
3489@ifset aout-bout
3490@cindex text section
3491@cindex data section
3492@itemx text section
3493@itemx data section
3494@end ifset
a4fb0134 3495These sections hold your program. @command{@value{AS}} and @code{@value{LD}} treat them as
252b5132 3496separate but equal sections. Anything you can say of one section is
c1253627
NC
3497true of another.
3498@c @ifset aout-bout
252b5132
RH
3499When the program is running, however, it is
3500customary for the text section to be unalterable. The
3501text section is often shared among processes: it contains
3502instructions, constants and the like. The data section of a running
3503program is usually alterable: for example, C variables would be stored
3504in the data section.
c1253627 3505@c @end ifset
252b5132
RH
3506
3507@cindex bss section
3508@item bss section
3509This section contains zeroed bytes when your program begins running. It
a349d9dd 3510is used to hold uninitialized variables or common storage. The length of
252b5132
RH
3511each partial program's bss section is important, but because it starts
3512out containing zeroed bytes there is no need to store explicit zero
3513bytes in the object file. The bss section was invented to eliminate
3514those explicit zeros from object files.
3515
3516@cindex absolute section
3517@item absolute section
3518Address 0 of this section is always ``relocated'' to runtime address 0.
3519This is useful if you want to refer to an address that @code{@value{LD}} must
3520not change when relocating. In this sense we speak of absolute
3521addresses being ``unrelocatable'': they do not change during relocation.
3522
3523@cindex undefined section
3524@item undefined section
3525This ``section'' is a catch-all for address references to objects not in
3526the preceding sections.
3527@c FIXME: ref to some other doc on obj-file formats could go here.
3528@end table
3529
3530@cindex relocation example
3531An idealized example of three relocatable sections follows.
c1253627 3532@ifset COFF-ELF
252b5132
RH
3533The example uses the traditional section names @samp{.text} and @samp{.data}.
3534@end ifset
3535Memory addresses are on the horizontal axis.
3536
3537@c TEXI2ROFF-KILL
c1253627 3538@ifnottex
252b5132
RH
3539@c END TEXI2ROFF-KILL
3540@smallexample
3541 +-----+----+--+
3542partial program # 1: |ttttt|dddd|00|
3543 +-----+----+--+
3544
3545 text data bss
3546 seg. seg. seg.
3547
3548 +---+---+---+
3549partial program # 2: |TTT|DDD|000|
3550 +---+---+---+
3551
3552 +--+---+-----+--+----+---+-----+~~
3553linked program: | |TTT|ttttt| |dddd|DDD|00000|
3554 +--+---+-----+--+----+---+-----+~~
3555
3556 addresses: 0 @dots{}
3557@end smallexample
3558@c TEXI2ROFF-KILL
c1253627 3559@end ifnottex
252b5132
RH
3560@need 5000
3561@tex
c1253627 3562\bigskip
252b5132
RH
3563\line{\it Partial program \#1: \hfil}
3564\line{\ibox{2.5cm}{\tt text}\ibox{2cm}{\tt data}\ibox{1cm}{\tt bss}\hfil}
3565\line{\boxit{2.5cm}{\tt ttttt}\boxit{2cm}{\tt dddd}\boxit{1cm}{\tt 00}\hfil}
3566
3567\line{\it Partial program \#2: \hfil}
3568\line{\ibox{1cm}{\tt text}\ibox{1.5cm}{\tt data}\ibox{1cm}{\tt bss}\hfil}
3569\line{\boxit{1cm}{\tt TTT}\boxit{1.5cm}{\tt DDDD}\boxit{1cm}{\tt 000}\hfil}
3570
3571\line{\it linked program: \hfil}
3572\line{\ibox{.5cm}{}\ibox{1cm}{\tt text}\ibox{2.5cm}{}\ibox{.75cm}{}\ibox{2cm}{\tt data}\ibox{1.5cm}{}\ibox{2cm}{\tt bss}\hfil}
3573\line{\boxit{.5cm}{}\boxit{1cm}{\tt TTT}\boxit{2.5cm}{\tt
3574ttttt}\boxit{.75cm}{}\boxit{2cm}{\tt dddd}\boxit{1.5cm}{\tt
3575DDDD}\boxit{2cm}{\tt 00000}\ \dots\hfil}
3576
3577\line{\it addresses: \hfil}
3578\line{0\dots\hfil}
3579
3580@end tex
3581@c END TEXI2ROFF-KILL
3582
3583@node As Sections
3584@section Assembler Internal Sections
3585
3586@cindex internal assembler sections
3587@cindex sections in messages, internal
a4fb0134 3588These sections are meant only for the internal use of @command{@value{AS}}. They
252b5132 3589have no meaning at run-time. You do not really need to know about these
a4fb0134 3590sections for most purposes; but they can be mentioned in @command{@value{AS}}
252b5132 3591warning messages, so it might be helpful to have an idea of their
a4fb0134 3592meanings to @command{@value{AS}}. These sections are used to permit the
252b5132
RH
3593value of every expression in your assembly language program to be a
3594section-relative address.
3595
3596@table @b
3597@cindex assembler internal logic error
3598@item ASSEMBLER-INTERNAL-LOGIC-ERROR!
3599An internal assembler logic error has been found. This means there is a
3600bug in the assembler.
3601
3602@cindex expr (internal section)
3603@item expr section
3604The assembler stores complex expression internally as combinations of
3605symbols. When it needs to represent an expression as a symbol, it puts
3606it in the expr section.
3607@c FIXME item debug
3608@c FIXME item transfer[t] vector preload
3609@c FIXME item transfer[t] vector postload
3610@c FIXME item register
3611@end table
3612
3613@node Sub-Sections
3614@section Sub-Sections
3615
3616@cindex numbered subsections
3617@cindex grouping data
3618@ifset aout-bout
3619Assembled bytes
c1253627 3620@ifset COFF-ELF
252b5132
RH
3621conventionally
3622@end ifset
3623fall into two sections: text and data.
3624@end ifset
3625You may have separate groups of
3626@ifset GENERIC
3627data in named sections
3628@end ifset
3629@ifclear GENERIC
3630@ifclear aout-bout
3631data in named sections
3632@end ifclear
3633@ifset aout-bout
3634text or data
3635@end ifset
3636@end ifclear
3637that you want to end up near to each other in the object file, even though they
a4fb0134 3638are not contiguous in the assembler source. @command{@value{AS}} allows you to
252b5132
RH
3639use @dfn{subsections} for this purpose. Within each section, there can be
3640numbered subsections with values from 0 to 8192. Objects assembled into the
3641same subsection go into the object file together with other objects in the same
3642subsection. For example, a compiler might want to store constants in the text
3643section, but might not want to have them interspersed with the program being
3644assembled. In this case, the compiler could issue a @samp{.text 0} before each
3645section of code being output, and a @samp{.text 1} before each group of
3646constants being output.
3647
3648Subsections are optional. If you do not use subsections, everything
3649goes in subsection number zero.
3650
3651@ifset GENERIC
3652Each subsection is zero-padded up to a multiple of four bytes.
3653(Subsections may be padded a different amount on different flavors
a4fb0134 3654of @command{@value{AS}}.)
252b5132
RH
3655@end ifset
3656@ifclear GENERIC
3657@ifset H8
7be1c489 3658On the H8/300 platform, each subsection is zero-padded to a word
252b5132 3659boundary (two bytes).
c2dcd04e 3660The same is true on the Renesas SH.
252b5132
RH
3661@end ifset
3662@ifset I960
3663@c FIXME section padding (alignment)?
3664@c Rich Pixley says padding here depends on target obj code format; that
3665@c doesn't seem particularly useful to say without further elaboration,
3666@c so for now I say nothing about it. If this is a generic BFD issue,
3667@c these paragraphs might need to vanish from this manual, and be
3668@c discussed in BFD chapter of binutils (or some such).
3669@end ifset
252b5132
RH
3670@end ifclear
3671
3672Subsections appear in your object file in numeric order, lowest numbered
3673to highest. (All this to be compatible with other people's assemblers.)
3674The object file contains no representation of subsections; @code{@value{LD}} and
3675other programs that manipulate object files see no trace of them.
3676They just see all your text subsections as a text section, and all your
3677data subsections as a data section.
3678
3679To specify which subsection you want subsequent statements assembled
3680into, use a numeric argument to specify it, in a @samp{.text
3681@var{expression}} or a @samp{.data @var{expression}} statement.
ed9589d4 3682@ifset COFF
252b5132 3683@ifset GENERIC
ed9589d4 3684When generating COFF output, you
252b5132
RH
3685@end ifset
3686@ifclear GENERIC
3687You
3688@end ifclear
3689can also use an extra subsection
3690argument with arbitrary named sections: @samp{.section @var{name},
3691@var{expression}}.
3692@end ifset
ed9589d4
BW
3693@ifset ELF
3694@ifset GENERIC
3695When generating ELF output, you
3696@end ifset
3697@ifclear GENERIC
3698You
3699@end ifclear
3700can also use the @code{.subsection} directive (@pxref{SubSection})
3701to specify a subsection: @samp{.subsection @var{expression}}.
3702@end ifset
96e9638b
BW
3703@var{Expression} should be an absolute expression
3704(@pxref{Expressions}). If you just say @samp{.text} then @samp{.text 0}
252b5132
RH
3705is assumed. Likewise @samp{.data} means @samp{.data 0}. Assembly
3706begins in @code{text 0}. For instance:
3707@smallexample
3708.text 0 # The default subsection is text 0 anyway.
3709.ascii "This lives in the first text subsection. *"
3710.text 1
3711.ascii "But this lives in the second text subsection."
3712.data 0
3713.ascii "This lives in the data section,"
3714.ascii "in the first data subsection."
3715.text 0
3716.ascii "This lives in the first text section,"
3717.ascii "immediately following the asterisk (*)."
3718@end smallexample
3719
3720Each section has a @dfn{location counter} incremented by one for every byte
3721assembled into that section. Because subsections are merely a convenience
a4fb0134 3722restricted to @command{@value{AS}} there is no concept of a subsection location
252b5132
RH
3723counter. There is no way to directly manipulate a location counter---but the
3724@code{.align} directive changes it, and any label definition captures its
3725current value. The location counter of the section where statements are being
3726assembled is said to be the @dfn{active} location counter.
3727
3728@node bss
3729@section bss Section
3730
3731@cindex bss section
3732@cindex common variable storage
3733The bss section is used for local common variable storage.
3734You may allocate address space in the bss section, but you may
3735not dictate data to load into it before your program executes. When
3736your program starts running, all the contents of the bss
3737section are zeroed bytes.
3738
3739The @code{.lcomm} pseudo-op defines a symbol in the bss section; see
3740@ref{Lcomm,,@code{.lcomm}}.
3741
3742The @code{.comm} pseudo-op may be used to declare a common symbol, which is
96e9638b 3743another form of uninitialized symbol; see @ref{Comm,,@code{.comm}}.
252b5132
RH
3744
3745@ifset GENERIC
3746When assembling for a target which supports multiple sections, such as ELF or
3747COFF, you may switch into the @code{.bss} section and define symbols as usual;
3748see @ref{Section,,@code{.section}}. You may only assemble zero values into the
3749section. Typically the section will only contain symbol definitions and
3750@code{.skip} directives (@pxref{Skip,,@code{.skip}}).
3751@end ifset
3752
3753@node Symbols
3754@chapter Symbols
3755
3756@cindex symbols
3757Symbols are a central concept: the programmer uses symbols to name
3758things, the linker uses symbols to link, and the debugger uses symbols
3759to debug.
3760
3761@quotation
3762@cindex debuggers, and symbol order
a4fb0134 3763@emph{Warning:} @command{@value{AS}} does not place symbols in the object file in
252b5132
RH
3764the same order they were declared. This may break some debuggers.
3765@end quotation
3766
3767@menu
3768* Labels:: Labels
3769* Setting Symbols:: Giving Symbols Other Values
3770* Symbol Names:: Symbol Names
3771* Dot:: The Special Dot Symbol
3772* Symbol Attributes:: Symbol Attributes
3773@end menu
3774
3775@node Labels
3776@section Labels
3777
3778@cindex labels
3779A @dfn{label} is written as a symbol immediately followed by a colon
3780@samp{:}. The symbol then represents the current value of the
3781active location counter, and is, for example, a suitable instruction
3782operand. You are warned if you use the same symbol to represent two
3783different locations: the first definition overrides any other
3784definitions.
3785
3786@ifset HPPA
3787On the HPPA, the usual form for a label need not be immediately followed by a
3788colon, but instead must start in column zero. Only one label may be defined on
a4fb0134 3789a single line. To work around this, the HPPA version of @command{@value{AS}} also
252b5132
RH
3790provides a special directive @code{.label} for defining labels more flexibly.
3791@end ifset
3792
3793@node Setting Symbols
3794@section Giving Symbols Other Values
3795
3796@cindex assigning values to symbols
3797@cindex symbol values, assigning
3798A symbol can be given an arbitrary value by writing a symbol, followed
3799by an equals sign @samp{=}, followed by an expression
3800(@pxref{Expressions}). This is equivalent to using the @code{.set}
9497f5ac
NC
3801directive. @xref{Set,,@code{.set}}. In the same way, using a double
3802equals sign @samp{=}@samp{=} here represents an equivalent of the
3803@code{.eqv} directive. @xref{Eqv,,@code{.eqv}}.
252b5132 3804
f8739b83
JZ
3805@ifset Blackfin
3806Blackfin does not support symbol assignment with @samp{=}.
3807@end ifset
3808
252b5132
RH
3809@node Symbol Names
3810@section Symbol Names
3811
3812@cindex symbol names
3813@cindex names, symbol
3814@ifclear SPECIAL-SYMS
3815Symbol names begin with a letter or with one of @samp{._}. On most
3816machines, you can also use @code{$} in symbol names; exceptions are
3817noted in @ref{Machine Dependencies}. That character may be followed by any
96e9638b
BW
3818string of digits, letters, dollar signs (unless otherwise noted for a
3819particular target machine), and underscores.
252b5132 3820@end ifclear
252b5132
RH
3821@ifset SPECIAL-SYMS
3822@ifset H8
3823Symbol names begin with a letter or with one of @samp{._}. On the
7be1c489 3824Renesas SH you can also use @code{$} in symbol names. That
c2dcd04e
NC
3825character may be followed by any string of digits, letters, dollar signs (save
3826on the H8/300), and underscores.
252b5132
RH
3827@end ifset
3828@end ifset
3829
3830Case of letters is significant: @code{foo} is a different symbol name
3831than @code{Foo}.
3832
ed1fcdd1
NC
3833Symbol names do not start with a digit. An exception to this rule is made for
3834Local Labels. See below.
3835
7bfd842d
NC
3836Multibyte characters are supported. To generate a symbol name containing
3837multibyte characters enclose it within double quotes and use escape codes. cf
3838@xref{Strings}. Generating a multibyte symbol name from a label is not
3839currently supported.
3840
252b5132
RH
3841Each symbol has exactly one name. Each name in an assembly language program
3842refers to exactly one symbol. You may use that symbol name any number of times
3843in a program.
3844
3845@subheading Local Symbol Names
3846
3847@cindex local symbol names
3848@cindex symbol names, local
ba83aca1
BW
3849A local symbol is any symbol beginning with certain local label prefixes.
3850By default, the local label prefix is @samp{.L} for ELF systems or
3851@samp{L} for traditional a.out systems, but each target may have its own
3852set of local label prefixes.
3853@ifset HPPA
3854On the HPPA local symbols begin with @samp{L$}.
3855@end ifset
3856
3857Local symbols are defined and used within the assembler, but they are
3858normally not saved in object files. Thus, they are not visible when debugging.
5c9352f3
AM
3859You may use the @samp{-L} option (@pxref{L, ,Include Local Symbols})
3860to retain the local symbols in the object files.
ba83aca1
BW
3861
3862@subheading Local Labels
3863
3864@cindex local labels
252b5132
RH
3865@cindex temporary symbol names
3866@cindex symbol names, temporary
ed1fcdd1
NC
3867Local labels are different from local symbols. Local labels help compilers and
3868programmers use names temporarily. They create symbols which are guaranteed to
3869be unique over the entire scope of the input source code and which can be
3870referred to by a simple notation. To define a local label, write a label of
9791c250
AM
3871the form @samp{@b{N}:} (where @b{N} represents any non-negative integer).
3872To refer to the most recent previous definition of that label write
3873@samp{@b{N}b}, using the same number as when you defined the label. To refer
3874to the next definition of a local label, write @samp{@b{N}f}. The @samp{b}
3875stands for ``backwards'' and the @samp{f} stands for ``forwards''.
2d5aaba0
NC
3876
3877There is no restriction on how you can use these labels, and you can reuse them
3878too. So that it is possible to repeatedly define the same local label (using
3879the same number @samp{@b{N}}), although you can only refer to the most recently
3880defined local label of that number (for a backwards reference) or the next
3881definition of a specific local label for a forward reference. It is also worth
3882noting that the first 10 local labels (@samp{@b{0:}}@dots{}@samp{@b{9:}}) are
3883implemented in a slightly more efficient manner than the others.
3884
3885Here is an example:
3886
3887@smallexample
38881: branch 1f
38892: branch 1b
38901: branch 2f
38912: branch 1b
3892@end smallexample
3893
3894Which is the equivalent of:
3895
3896@smallexample
3897label_1: branch label_3
3898label_2: branch label_1
3899label_3: branch label_4
3900label_4: branch label_3
3901@end smallexample
3902
ba83aca1 3903Local label names are only a notational device. They are immediately
2d5aaba0 3904transformed into more conventional symbol names before the assembler uses them.
96e9638b
BW
3905The symbol names are stored in the symbol table, appear in error messages, and
3906are optionally emitted to the object file. The names are constructed using
3907these parts:
252b5132
RH
3908
3909@table @code
ba83aca1
BW
3910@item @emph{local label prefix}
3911All local symbols begin with the system-specific local label prefix.
3912Normally both @command{@value{AS}} and @code{@value{LD}} forget symbols
3913that start with the local label prefix. These labels are
252b5132 3914used for symbols you are never intended to see. If you use the
a4fb0134 3915@samp{-L} option then @command{@value{AS}} retains these symbols in the
252b5132
RH
3916object file. If you also instruct @code{@value{LD}} to retain these symbols,
3917you may use them in debugging.
3918
2d5aaba0
NC
3919@item @var{number}
3920This is the number that was used in the local label definition. So if the
01642c12 3921label is written @samp{55:} then the number is @samp{55}.
252b5132 3922
2d5aaba0
NC
3923@item @kbd{C-B}
3924This unusual character is included so you do not accidentally invent a symbol
3925of the same name. The character has ASCII value of @samp{\002} (control-B).
252b5132
RH
3926
3927@item @emph{ordinal number}
2d5aaba0 3928This is a serial number to keep the labels distinct. The first definition of
01642c12 3929@samp{0:} gets the number @samp{1}. The 15th definition of @samp{0:} gets the
2d5aaba0 3930number @samp{15}, and so on. Likewise the first definition of @samp{1:} gets
b45619c0 3931the number @samp{1} and its 15th definition gets @samp{15} as well.
252b5132
RH
3932@end table
3933
ba83aca1
BW
3934So for example, the first @code{1:} may be named @code{.L1@kbd{C-B}1}, and
3935the 44th @code{3:} may be named @code{.L3@kbd{C-B}44}.
2d5aaba0
NC
3936
3937@subheading Dollar Local Labels
3938@cindex dollar local symbols
3939
ed1fcdd1
NC
3940On some targets @code{@value{AS}} also supports an even more local form of
3941local labels called dollar labels. These labels go out of scope (i.e., they
3942become undefined) as soon as a non-local label is defined. Thus they remain
3943valid for only a small region of the input source code. Normal local labels,
3944by contrast, remain in scope for the entire file, or until they are redefined
3945by another occurrence of the same local label.
2d5aaba0
NC
3946
3947Dollar labels are defined in exactly the same way as ordinary local labels,
77cca80f
NC
3948except that they have a dollar sign suffix to their numeric value, e.g.,
3949@samp{@b{55$:}}.
2d5aaba0
NC
3950
3951They can also be distinguished from ordinary local labels by their transformed
96e9638b
BW
3952names which use ASCII character @samp{\001} (control-A) as the magic character
3953to distinguish them from ordinary labels. For example, the fifth definition of
ba83aca1 3954@samp{6$} may be named @samp{.L6@kbd{C-A}5}.
252b5132
RH
3955
3956@node Dot
3957@section The Special Dot Symbol
3958
3959@cindex dot (symbol)
3960@cindex @code{.} (symbol)
3961@cindex current address
3962@cindex location counter
3963The special symbol @samp{.} refers to the current address that
a4fb0134 3964@command{@value{AS}} is assembling into. Thus, the expression @samp{melvin:
252b5132
RH
3965.long .} defines @code{melvin} to contain its own address.
3966Assigning a value to @code{.} is treated the same as a @code{.org}
884f0d36 3967directive.
252b5132 3968@ifclear no-space-dir
884f0d36 3969Thus, the expression @samp{.=.+4} is the same as saying
252b5132
RH
3970@samp{.space 4}.
3971@end ifclear
252b5132
RH
3972
3973@node Symbol Attributes
3974@section Symbol Attributes
3975
3976@cindex symbol attributes
3977@cindex attributes, symbol
3978Every symbol has, as well as its name, the attributes ``Value'' and
3979``Type''. Depending on output format, symbols can also have auxiliary
3980attributes.
3981@ifset INTERNALS
3982The detailed definitions are in @file{a.out.h}.
3983@end ifset
3984
a4fb0134 3985If you use a symbol without defining it, @command{@value{AS}} assumes zero for
252b5132
RH
3986all these attributes, and probably won't warn you. This makes the
3987symbol an externally defined symbol, which is generally what you
3988would want.
3989
3990@menu
3991* Symbol Value:: Value
3992* Symbol Type:: Type
3993@ifset aout-bout
3994@ifset GENERIC
3995* a.out Symbols:: Symbol Attributes: @code{a.out}
3996@end ifset
3997@ifclear GENERIC
3998@ifclear BOUT
3999* a.out Symbols:: Symbol Attributes: @code{a.out}
4000@end ifclear
4001@ifset BOUT
4002* a.out Symbols:: Symbol Attributes: @code{a.out}, @code{b.out}
4003@end ifset
4004@end ifclear
4005@end ifset
4006@ifset COFF
4007* COFF Symbols:: Symbol Attributes for COFF
4008@end ifset
4009@ifset SOM
4010* SOM Symbols:: Symbol Attributes for SOM
4011@end ifset
4012@end menu
4013
4014@node Symbol Value
4015@subsection Value
4016
4017@cindex value of a symbol
4018@cindex symbol value
4019The value of a symbol is (usually) 32 bits. For a symbol which labels a
4020location in the text, data, bss or absolute sections the value is the
4021number of addresses from the start of that section to the label.
4022Naturally for text, data and bss sections the value of a symbol changes
4023as @code{@value{LD}} changes section base addresses during linking. Absolute
4024symbols' values do not change during linking: that is why they are
4025called absolute.
4026
4027The value of an undefined symbol is treated in a special way. If it is
40280 then the symbol is not defined in this assembler source file, and
4029@code{@value{LD}} tries to determine its value from other files linked into the
4030same program. You make this kind of symbol simply by mentioning a symbol
4031name without defining it. A non-zero value represents a @code{.comm}
4032common declaration. The value is how much common storage to reserve, in
4033bytes (addresses). The symbol refers to the first address of the
4034allocated storage.
4035
4036@node Symbol Type
4037@subsection Type
4038
4039@cindex type of a symbol
4040@cindex symbol type
4041The type attribute of a symbol contains relocation (section)
4042information, any flag settings indicating that a symbol is external, and
4043(optionally), other information for linkers and debuggers. The exact
4044format depends on the object-code output format in use.
4045
4046@ifset aout-bout
4047@ifclear GENERIC
4048@ifset BOUT
4049@c The following avoids a "widow" subsection title. @group would be
4050@c better if it were available outside examples.
4051@need 1000
4052@node a.out Symbols
4053@subsection Symbol Attributes: @code{a.out}, @code{b.out}
4054
4055@cindex @code{b.out} symbol attributes
4056@cindex symbol attributes, @code{b.out}
a4fb0134 4057These symbol attributes appear only when @command{@value{AS}} is configured for
252b5132
RH
4058one of the Berkeley-descended object output formats---@code{a.out} or
4059@code{b.out}.
4060
4061@end ifset
4062@ifclear BOUT
4063@node a.out Symbols
4064@subsection Symbol Attributes: @code{a.out}
4065
4066@cindex @code{a.out} symbol attributes
4067@cindex symbol attributes, @code{a.out}
4068
4069@end ifclear
4070@end ifclear
4071@ifset GENERIC
4072@node a.out Symbols
4073@subsection Symbol Attributes: @code{a.out}
4074
4075@cindex @code{a.out} symbol attributes
4076@cindex symbol attributes, @code{a.out}
4077
4078@end ifset
4079@menu
4080* Symbol Desc:: Descriptor
4081* Symbol Other:: Other
4082@end menu
4083
4084@node Symbol Desc
4085@subsubsection Descriptor
4086
4087@cindex descriptor, of @code{a.out} symbol
4088This is an arbitrary 16-bit value. You may establish a symbol's
4089descriptor value by using a @code{.desc} statement
4090(@pxref{Desc,,@code{.desc}}). A descriptor value means nothing to
a4fb0134 4091@command{@value{AS}}.
252b5132
RH
4092
4093@node Symbol Other
4094@subsubsection Other
4095
4096@cindex other attribute, of @code{a.out} symbol
a4fb0134 4097This is an arbitrary 8-bit value. It means nothing to @command{@value{AS}}.
252b5132
RH
4098@end ifset
4099
4100@ifset COFF
4101@node COFF Symbols
4102@subsection Symbol Attributes for COFF
4103
4104@cindex COFF symbol attributes
4105@cindex symbol attributes, COFF
4106
4107The COFF format supports a multitude of auxiliary symbol attributes;
4108like the primary symbol attributes, they are set between @code{.def} and
4109@code{.endef} directives.
4110
4111@subsubsection Primary Attributes
4112
4113@cindex primary attributes, COFF symbols
4114The symbol name is set with @code{.def}; the value and type,
4115respectively, with @code{.val} and @code{.type}.
4116
4117@subsubsection Auxiliary Attributes
4118
4119@cindex auxiliary attributes, COFF symbols
a4fb0134 4120The @command{@value{AS}} directives @code{.dim}, @code{.line}, @code{.scl},
c87db184
CF
4121@code{.size}, @code{.tag}, and @code{.weak} can generate auxiliary symbol
4122table information for COFF.
252b5132
RH
4123@end ifset
4124
4125@ifset SOM
4126@node SOM Symbols
4127@subsection Symbol Attributes for SOM
4128
4129@cindex SOM symbol attributes
4130@cindex symbol attributes, SOM
4131
4132The SOM format for the HPPA supports a multitude of symbol attributes set with
4133the @code{.EXPORT} and @code{.IMPORT} directives.
4134
01642c12 4135The attributes are described in @cite{HP9000 Series 800 Assembly
252b5132
RH
4136Language Reference Manual} (HP 92432-90001) under the @code{IMPORT} and
4137@code{EXPORT} assembler directive documentation.
4138@end ifset
4139
4140@node Expressions
4141@chapter Expressions
4142
4143@cindex expressions
4144@cindex addresses
4145@cindex numeric values
4146An @dfn{expression} specifies an address or numeric value.
4147Whitespace may precede and/or follow an expression.
4148
4149The result of an expression must be an absolute number, or else an offset into
4150a particular section. If an expression is not absolute, and there is not
a4fb0134 4151enough information when @command{@value{AS}} sees the expression to know its
252b5132
RH
4152section, a second pass over the source program might be necessary to interpret
4153the expression---but the second pass is currently not implemented.
a4fb0134 4154@command{@value{AS}} aborts with an error message in this situation.
252b5132
RH
4155
4156@menu
4157* Empty Exprs:: Empty Expressions
4158* Integer Exprs:: Integer Expressions
4159@end menu
4160
4161@node Empty Exprs
4162@section Empty Expressions
4163
4164@cindex empty expressions
4165@cindex expressions, empty
4166An empty expression has no value: it is just whitespace or null.
4167Wherever an absolute expression is required, you may omit the
a4fb0134 4168expression, and @command{@value{AS}} assumes a value of (absolute) 0. This
252b5132
RH
4169is compatible with other assemblers.
4170
4171@node Integer Exprs
4172@section Integer Expressions
4173
4174@cindex integer expressions
4175@cindex expressions, integer
4176An @dfn{integer expression} is one or more @emph{arguments} delimited
4177by @emph{operators}.
4178
4179@menu
4180* Arguments:: Arguments
4181* Operators:: Operators
4182* Prefix Ops:: Prefix Operators
4183* Infix Ops:: Infix Operators
4184@end menu
4185
4186@node Arguments
4187@subsection Arguments
4188
4189@cindex expression arguments
4190@cindex arguments in expressions
4191@cindex operands in expressions
4192@cindex arithmetic operands
4193@dfn{Arguments} are symbols, numbers or subexpressions. In other
4194contexts arguments are sometimes called ``arithmetic operands''. In
4195this manual, to avoid confusing them with the ``instruction operands'' of
4196the machine language, we use the term ``argument'' to refer to parts of
4197expressions only, reserving the word ``operand'' to refer only to machine
4198instruction operands.
4199
4200Symbols are evaluated to yield @{@var{section} @var{NNN}@} where
4201@var{section} is one of text, data, bss, absolute,
4202or undefined. @var{NNN} is a signed, 2's complement 32 bit
4203integer.
4204
4205Numbers are usually integers.
4206
4207A number can be a flonum or bignum. In this case, you are warned
a4fb0134 4208that only the low order 32 bits are used, and @command{@value{AS}} pretends
252b5132
RH
4209these 32 bits are an integer. You may write integer-manipulating
4210instructions that act on exotic constants, compatible with other
4211assemblers.
4212
4213@cindex subexpressions
4214Subexpressions are a left parenthesis @samp{(} followed by an integer
4215expression, followed by a right parenthesis @samp{)}; or a prefix
4216operator followed by an argument.
4217
4218@node Operators
4219@subsection Operators
4220
4221@cindex operators, in expressions
4222@cindex arithmetic functions
4223@cindex functions, in expressions
4224@dfn{Operators} are arithmetic functions, like @code{+} or @code{%}. Prefix
4225operators are followed by an argument. Infix operators appear
4226between their arguments. Operators may be preceded and/or followed by
4227whitespace.
4228
4229@node Prefix Ops
4230@subsection Prefix Operator
4231
4232@cindex prefix operators
a4fb0134 4233@command{@value{AS}} has the following @dfn{prefix operators}. They each take
252b5132
RH
4234one argument, which must be absolute.
4235
4236@c the tex/end tex stuff surrounding this small table is meant to make
4237@c it align, on the printed page, with the similar table in the next
4238@c section (which is inside an enumerate).
4239@tex
4240\global\advance\leftskip by \itemindent
4241@end tex
4242
4243@table @code
4244@item -
4245@dfn{Negation}. Two's complement negation.
4246@item ~
4247@dfn{Complementation}. Bitwise not.
4248@end table
4249
4250@tex
4251\global\advance\leftskip by -\itemindent
4252@end tex
4253
4254@node Infix Ops
4255@subsection Infix Operators
4256
4257@cindex infix operators
4258@cindex operators, permitted arguments
4259@dfn{Infix operators} take two arguments, one on either side. Operators
4260have precedence, but operations with equal precedence are performed left
a4fb0134 4261to right. Apart from @code{+} or @option{-}, both arguments must be
252b5132
RH
4262absolute, and the result is absolute.
4263
4264@enumerate
4265@cindex operator precedence
4266@cindex precedence of operators
4267
4268@item
4269Highest Precedence
4270
4271@table @code
4272@item *
4273@dfn{Multiplication}.
4274
4275@item /
4276@dfn{Division}. Truncation is the same as the C operator @samp{/}
4277
4278@item %
4279@dfn{Remainder}.
4280
d1eac9d9 4281@item <<
252b5132
RH
4282@dfn{Shift Left}. Same as the C operator @samp{<<}.
4283
d1eac9d9 4284@item >>
252b5132
RH
4285@dfn{Shift Right}. Same as the C operator @samp{>>}.
4286@end table
4287
4288@item
4289Intermediate precedence
4290
4291@table @code
4292@item |
4293
4294@dfn{Bitwise Inclusive Or}.
4295
4296@item &
4297@dfn{Bitwise And}.
4298
4299@item ^
4300@dfn{Bitwise Exclusive Or}.
4301
4302@item !
4303@dfn{Bitwise Or Not}.
4304@end table
4305
4306@item
b131d4dc 4307Low Precedence
252b5132
RH
4308
4309@table @code
4310@cindex addition, permitted arguments
4311@cindex plus, permitted arguments
4312@cindex arguments for addition
4313@item +
4314@dfn{Addition}. If either argument is absolute, the result has the section of
4315the other argument. You may not add together arguments from different
4316sections.
4317
4318@cindex subtraction, permitted arguments
4319@cindex minus, permitted arguments
4320@cindex arguments for subtraction
4321@item -
4322@dfn{Subtraction}. If the right argument is absolute, the
4323result has the section of the left argument.
4324If both arguments are in the same section, the result is absolute.
4325You may not subtract arguments from different sections.
4326@c FIXME is there still something useful to say about undefined - undefined ?
b131d4dc
NC
4327
4328@cindex comparison expressions
4329@cindex expressions, comparison
4330@item ==
4331@dfn{Is Equal To}
4332@item <>
723a8472 4333@itemx !=
b131d4dc
NC
4334@dfn{Is Not Equal To}
4335@item <
4336@dfn{Is Less Than}
d1eac9d9 4337@item >
b131d4dc 4338@dfn{Is Greater Than}
d1eac9d9 4339@item >=
b131d4dc 4340@dfn{Is Greater Than Or Equal To}
d1eac9d9 4341@item <=
b131d4dc
NC
4342@dfn{Is Less Than Or Equal To}
4343
4344The comparison operators can be used as infix operators. A true results has a
4345value of -1 whereas a false result has a value of 0. Note, these operators
4346perform signed comparisons.
4347@end table
4348
4349@item Lowest Precedence
4350
4351@table @code
4352@item &&
4353@dfn{Logical And}.
4354
4355@item ||
4356@dfn{Logical Or}.
4357
4358These two logical operations can be used to combine the results of sub
4359expressions. Note, unlike the comparison operators a true result returns a
4360value of 1 but a false results does still return 0. Also note that the logical
4361or operator has a slightly lower precedence than logical and.
4362
252b5132
RH
4363@end table
4364@end enumerate
4365
4366In short, it's only meaningful to add or subtract the @emph{offsets} in an
4367address; you can only have a defined section in one of the two arguments.
4368
4369@node Pseudo Ops
4370@chapter Assembler Directives
4371
4372@cindex directives, machine independent
4373@cindex pseudo-ops, machine independent
4374@cindex machine independent directives
4375All assembler directives have names that begin with a period (@samp{.}).
7e302352
RS
4376The names are case insensitive for most targets, and usually written
4377in lower case.
252b5132
RH
4378
4379This chapter discusses directives that are available regardless of the
4380target machine configuration for the @sc{gnu} assembler.
4381@ifset GENERIC
4382Some machine configurations provide additional directives.
4383@xref{Machine Dependencies}.
4384@end ifset
4385@ifclear GENERIC
4386@ifset machine-directives
96e9638b 4387@xref{Machine Dependencies}, for additional directives.
252b5132
RH
4388@end ifset
4389@end ifclear
4390
4391@menu
4392* Abort:: @code{.abort}
4393@ifset COFF
38a57ae7 4394* ABORT (COFF):: @code{.ABORT}
252b5132 4395@end ifset
f0dc282c 4396
252b5132 4397* Align:: @code{.align @var{abs-expr} , @var{abs-expr}}
caa32fe5 4398* Altmacro:: @code{.altmacro}
252b5132
RH
4399* Ascii:: @code{.ascii "@var{string}"}@dots{}
4400* Asciz:: @code{.asciz "@var{string}"}@dots{}
4401* Balign:: @code{.balign @var{abs-expr} , @var{abs-expr}}
d3b47e2b 4402* Bundle directives:: @code{.bundle_align_mode @var{abs-expr}}, etc
252b5132 4403* Byte:: @code{.byte @var{expressions}}
4b7d318b 4404* CFI directives:: @code{.cfi_startproc [simple]}, @code{.cfi_endproc}, etc.
ccf8a69b 4405* Comm:: @code{.comm @var{symbol} , @var{length} }
252b5132
RH
4406* Data:: @code{.data @var{subsection}}
4407@ifset COFF
4408* Def:: @code{.def @var{name}}
4409@end ifset
4410@ifset aout-bout
4411* Desc:: @code{.desc @var{symbol}, @var{abs-expression}}
4412@end ifset
4413@ifset COFF
4414* Dim:: @code{.dim}
4415@end ifset
f0dc282c 4416
252b5132
RH
4417* Double:: @code{.double @var{flonums}}
4418* Eject:: @code{.eject}
4419* Else:: @code{.else}
3fd9f047 4420* Elseif:: @code{.elseif}
252b5132
RH
4421* End:: @code{.end}
4422@ifset COFF
4423* Endef:: @code{.endef}
4424@end ifset
f0dc282c 4425
252b5132
RH
4426* Endfunc:: @code{.endfunc}
4427* Endif:: @code{.endif}
4428* Equ:: @code{.equ @var{symbol}, @var{expression}}
4429* Equiv:: @code{.equiv @var{symbol}, @var{expression}}
9497f5ac 4430* Eqv:: @code{.eqv @var{symbol}, @var{expression}}
252b5132 4431* Err:: @code{.err}
d190d046 4432* Error:: @code{.error @var{string}}
252b5132
RH
4433* Exitm:: @code{.exitm}
4434* Extern:: @code{.extern}
4435* Fail:: @code{.fail}
14082c76 4436* File:: @code{.file}
252b5132
RH
4437* Fill:: @code{.fill @var{repeat} , @var{size} , @var{value}}
4438* Float:: @code{.float @var{flonums}}
01642c12 4439* Func:: @code{.func}
252b5132 4440* Global:: @code{.global @var{symbol}}, @code{.globl @var{symbol}}
c91d2e08 4441@ifset ELF
3a99f02f 4442* Gnu_attribute:: @code{.gnu_attribute @var{tag},@var{value}}
c91d2e08
NC
4443* Hidden:: @code{.hidden @var{names}}
4444@end ifset
f0dc282c 4445
252b5132
RH
4446* hword:: @code{.hword @var{expressions}}
4447* Ident:: @code{.ident}
4448* If:: @code{.if @var{absolute expression}}
7e005732 4449* Incbin:: @code{.incbin "@var{file}"[,@var{skip}[,@var{count}]]}
252b5132
RH
4450* Include:: @code{.include "@var{file}"}
4451* Int:: @code{.int @var{expressions}}
c91d2e08
NC
4452@ifset ELF
4453* Internal:: @code{.internal @var{names}}
4454@end ifset
f0dc282c 4455
252b5132
RH
4456* Irp:: @code{.irp @var{symbol},@var{values}}@dots{}
4457* Irpc:: @code{.irpc @var{symbol},@var{values}}@dots{}
4458* Lcomm:: @code{.lcomm @var{symbol} , @var{length}}
4459* Lflags:: @code{.lflags}
4460@ifclear no-line-dir
4461* Line:: @code{.line @var{line-number}}
4462@end ifclear
f0dc282c 4463
252b5132
RH
4464* Linkonce:: @code{.linkonce [@var{type}]}
4465* List:: @code{.list}
bd0eb99b 4466* Ln:: @code{.ln @var{line-number}}
14082c76
BW
4467* Loc:: @code{.loc @var{fileno} @var{lineno}}
4468* Loc_mark_labels:: @code{.loc_mark_labels @var{enable}}
4d4175af
BW
4469@ifset ELF
4470* Local:: @code{.local @var{names}}
4471@end ifset
bd0eb99b 4472
252b5132
RH
4473* Long:: @code{.long @var{expressions}}
4474@ignore
4475* Lsym:: @code{.lsym @var{symbol}, @var{expression}}
4476@end ignore
f0dc282c 4477
252b5132
RH
4478* Macro:: @code{.macro @var{name} @var{args}}@dots{}
4479* MRI:: @code{.mri @var{val}}
caa32fe5 4480* Noaltmacro:: @code{.noaltmacro}
252b5132 4481* Nolist:: @code{.nolist}
62a02d25 4482* Nop:: @code{.nop @var{size}[, @var{control}]}
252b5132 4483* Octa:: @code{.octa @var{bignums}}
9aec2026 4484* Offset:: @code{.offset @var{loc}}
85234291
L
4485* Org:: @code{.org @var{new-lc}, @var{fill}}
4486* P2align:: @code{.p2align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}}
c91d2e08
NC
4487@ifset ELF
4488* PopSection:: @code{.popsection}
4489* Previous:: @code{.previous}
4490@end ifset
f0dc282c 4491
252b5132 4492* Print:: @code{.print @var{string}}
c91d2e08
NC
4493@ifset ELF
4494* Protected:: @code{.protected @var{names}}
4495@end ifset
f0dc282c 4496
252b5132
RH
4497* Psize:: @code{.psize @var{lines}, @var{columns}}
4498* Purgem:: @code{.purgem @var{name}}
c91d2e08
NC
4499@ifset ELF
4500* PushSection:: @code{.pushsection @var{name}}
4501@end ifset
f0dc282c 4502
252b5132 4503* Quad:: @code{.quad @var{bignums}}
05e9452c 4504* Reloc:: @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]}
252b5132
RH
4505* Rept:: @code{.rept @var{count}}
4506* Sbttl:: @code{.sbttl "@var{subheading}"}
4507@ifset COFF
4508* Scl:: @code{.scl @var{class}}
c1253627
NC
4509@end ifset
4510@ifset COFF-ELF
7337fc21 4511* Section:: @code{.section @var{name}[, @var{flags}]}
252b5132 4512@end ifset
f0dc282c 4513
252b5132
RH
4514* Set:: @code{.set @var{symbol}, @var{expression}}
4515* Short:: @code{.short @var{expressions}}
4516* Single:: @code{.single @var{flonums}}
c1253627 4517@ifset COFF-ELF
c91d2e08 4518* Size:: @code{.size [@var{name} , @var{expression}]}
c1253627 4519@end ifset
884f0d36 4520@ifclear no-space-dir
252b5132 4521* Skip:: @code{.skip @var{size} , @var{fill}}
884f0d36
BW
4522@end ifclear
4523
252b5132 4524* Sleb128:: @code{.sleb128 @var{expressions}}
884f0d36 4525@ifclear no-space-dir
252b5132 4526* Space:: @code{.space @var{size} , @var{fill}}
884f0d36 4527@end ifclear
252b5132
RH
4528@ifset have-stabs
4529* Stab:: @code{.stabd, .stabn, .stabs}
4530@end ifset
f0dc282c 4531
38a57ae7 4532* String:: @code{.string "@var{str}"}, @code{.string8 "@var{str}"}, @code{.string16 "@var{str}"}, @code{.string32 "@var{str}"}, @code{.string64 "@var{str}"}
252b5132
RH
4533* Struct:: @code{.struct @var{expression}}
4534@ifset ELF
c91d2e08 4535* SubSection:: @code{.subsection}
252b5132
RH
4536* Symver:: @code{.symver @var{name},@var{name2@@nodename}}
4537@end ifset
f0dc282c 4538
252b5132
RH
4539@ifset COFF
4540* Tag:: @code{.tag @var{structname}}
4541@end ifset
f0dc282c 4542
252b5132
RH
4543* Text:: @code{.text @var{subsection}}
4544* Title:: @code{.title "@var{heading}"}
c1253627 4545@ifset COFF-ELF
c91d2e08 4546* Type:: @code{.type <@var{int} | @var{name} , @var{type description}>}
c1253627
NC
4547@end ifset
4548
c91d2e08 4549* Uleb128:: @code{.uleb128 @var{expressions}}
252b5132 4550@ifset COFF
252b5132
RH
4551* Val:: @code{.val @var{addr}}
4552@end ifset
f0dc282c 4553
2e13b764 4554@ifset ELF
c91d2e08 4555* Version:: @code{.version "@var{string}"}
c91d2e08
NC
4556* VTableEntry:: @code{.vtable_entry @var{table}, @var{offset}}
4557* VTableInherit:: @code{.vtable_inherit @var{child}, @var{parent}}
2e13b764 4558@end ifset
f0dc282c 4559
d190d046 4560* Warning:: @code{.warning @var{string}}
c87db184 4561* Weak:: @code{.weak @var{names}}
06e77878 4562* Weakref:: @code{.weakref @var{alias}, @var{symbol}}
252b5132 4563* Word:: @code{.word @var{expressions}}
7ce98c16
NC
4564@ifclear no-space-dir
4565* Zero:: @code{.zero @var{size}}
4566@end ifclear
2b841ec2
AM
4567@ifset ELF
4568* 2byte:: @code{.2byte @var{expressions}}
4569* 4byte:: @code{.4byte @var{expressions}}
4570* 8byte:: @code{.8byte @var{bignums}}
4571@end ifset
252b5132
RH
4572* Deprecated:: Deprecated Directives
4573@end menu
4574
4575@node Abort
4576@section @code{.abort}
4577
4578@cindex @code{abort} directive
4579@cindex stopping the assembly
4580This directive stops the assembly immediately. It is for
4581compatibility with other assemblers. The original idea was that the
4582assembly language source would be piped into the assembler. If the sender
a4fb0134 4583of the source quit, it could use this directive tells @command{@value{AS}} to
252b5132
RH
4584quit also. One day @code{.abort} will not be supported.
4585
4586@ifset COFF
370b66a1
CD
4587@node ABORT (COFF)
4588@section @code{.ABORT} (COFF)
252b5132
RH
4589
4590@cindex @code{ABORT} directive
a4fb0134 4591When producing COFF output, @command{@value{AS}} accepts this directive as a
252b5132
RH
4592synonym for @samp{.abort}.
4593
4594@ifset BOUT
a4fb0134 4595When producing @code{b.out} output, @command{@value{AS}} accepts this directive,
252b5132
RH
4596but ignores it.
4597@end ifset
4598@end ifset
4599
4600@node Align
4601@section @code{.align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}}
4602
4603@cindex padding the location counter
4604@cindex @code{align} directive
4605Pad the location counter (in the current subsection) to a particular storage
4606boundary. The first expression (which must be absolute) is the alignment
4607required, as described below.
4608
4609The second expression (also absolute) gives the fill value to be stored in the
4610padding bytes. It (and the comma) may be omitted. If it is omitted, the
2ca23e65 4611padding bytes are normally zero. However, on most systems, if the section is
252b5132
RH
4612marked as containing code and the fill value is omitted, the space is filled
4613with no-op instructions.
4614
4615The third expression is also absolute, and is also optional. If it is present,
4616it is the maximum number of bytes that should be skipped by this alignment
4617directive. If doing the alignment would require skipping more bytes than the
4618specified maximum, then the alignment is not done at all. You can omit the
4619fill value (the second argument) entirely by simply using two commas after the
4620required alignment; this can be useful if you want the alignment to be filled
4621with no-op instructions when appropriate.
4622
4623The way the required alignment is specified varies from system to system.
73589c9d 4624For the arc, hppa, i386 using ELF, i860, iq2000, m68k, or1k,
60946ad0 4625s390, sparc, tic4x, tic80 and xtensa, the first expression is the
252b5132
RH
4626alignment request in bytes. For example @samp{.align 8} advances
4627the location counter until it is a multiple of 8. If the location counter
60946ad0
AM
4628is already a multiple of 8, no change is needed. For the tic54x, the
4629first expression is the alignment request in words.
252b5132 4630
9e9a9798 4631For other systems, including ppc, i386 using a.out format, arm and
adcf07e6 4632strongarm, it is the
252b5132
RH
4633number of low-order zero bits the location counter must have after
4634advancement. For example @samp{.align 3} advances the location
4635counter until it a multiple of 8. If the location counter is already a
4636multiple of 8, no change is needed.
4637
4638This inconsistency is due to the different behaviors of the various
4639native assemblers for these systems which GAS must emulate.
4640GAS also provides @code{.balign} and @code{.p2align} directives,
4641described later, which have a consistent behavior across all
4642architectures (but are specific to GAS).
4643
ccf8a69b
BW
4644@node Altmacro
4645@section @code{.altmacro}
4646Enable alternate macro mode, enabling:
4647
4648@ftable @code
4649@item LOCAL @var{name} [ , @dots{} ]
4650One additional directive, @code{LOCAL}, is available. It is used to
4651generate a string replacement for each of the @var{name} arguments, and
4652replace any instances of @var{name} in each macro expansion. The
4653replacement string is unique in the assembly, and different for each
4654separate macro expansion. @code{LOCAL} allows you to write macros that
4655define symbols, without fear of conflict between separate macro expansions.
4656
4657@item String delimiters
4658You can write strings delimited in these other ways besides
4659@code{"@var{string}"}:
4660
4661@table @code
4662@item '@var{string}'
4663You can delimit strings with single-quote characters.
4664
4665@item <@var{string}>
4666You can delimit strings with matching angle brackets.
4667@end table
4668
4669@item single-character string escape
4670To include any single character literally in a string (even if the
4671character would otherwise have some special meaning), you can prefix the
4672character with @samp{!} (an exclamation mark). For example, you can
4673write @samp{<4.3 !> 5.4!!>} to get the literal text @samp{4.3 > 5.4!}.
4674
4675@item Expression results as strings
4676You can write @samp{%@var{expr}} to evaluate the expression @var{expr}
01642c12 4677and use the result as a string.
ccf8a69b
BW
4678@end ftable
4679
252b5132
RH
4680@node Ascii
4681@section @code{.ascii "@var{string}"}@dots{}
4682
4683@cindex @code{ascii} directive
4684@cindex string literals
4685@code{.ascii} expects zero or more string literals (@pxref{Strings})
4686separated by commas. It assembles each string (with no automatic
4687trailing zero byte) into consecutive addresses.
4688
4689@node Asciz
4690@section @code{.asciz "@var{string}"}@dots{}
4691
4692@cindex @code{asciz} directive
4693@cindex zero-terminated strings
4694@cindex null-terminated strings
4695@code{.asciz} is just like @code{.ascii}, but each string is followed by
4696a zero byte. The ``z'' in @samp{.asciz} stands for ``zero''.
4697
4698@node Balign
4699@section @code{.balign[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}}
4700
4701@cindex padding the location counter given number of bytes
4702@cindex @code{balign} directive
4703Pad the location counter (in the current subsection) to a particular
4704storage boundary. The first expression (which must be absolute) is the
4705alignment request in bytes. For example @samp{.balign 8} advances
4706the location counter until it is a multiple of 8. If the location counter
4707is already a multiple of 8, no change is needed.
4708
4709The second expression (also absolute) gives the fill value to be stored in the
4710padding bytes. It (and the comma) may be omitted. If it is omitted, the
2ca23e65 4711padding bytes are normally zero. However, on most systems, if the section is
252b5132
RH
4712marked as containing code and the fill value is omitted, the space is filled
4713with no-op instructions.
4714
4715The third expression is also absolute, and is also optional. If it is present,
4716it is the maximum number of bytes that should be skipped by this alignment
4717directive. If doing the alignment would require skipping more bytes than the
4718specified maximum, then the alignment is not done at all. You can omit the
4719fill value (the second argument) entirely by simply using two commas after the
4720required alignment; this can be useful if you want the alignment to be filled
4721with no-op instructions when appropriate.
4722
4723@cindex @code{balignw} directive
4724@cindex @code{balignl} directive
4725The @code{.balignw} and @code{.balignl} directives are variants of the
4726@code{.balign} directive. The @code{.balignw} directive treats the fill
4727pattern as a two byte word value. The @code{.balignl} directives treats the
4728fill pattern as a four byte longword value. For example, @code{.balignw
47294,0x368d} will align to a multiple of 4. If it skips two bytes, they will be
4730filled in with the value 0x368d (the exact placement of the bytes depends upon
4731the endianness of the processor). If it skips 1 or 3 bytes, the fill value is
4732undefined.
4733
fa94de6b 4734@node Bundle directives
d3b47e2b
L
4735@section Bundle directives
4736@subsection @code{.bundle_align_mode @var{abs-expr}}
fa94de6b
RM
4737@cindex @code{bundle_align_mode} directive
4738@cindex bundle
4739@cindex instruction bundle
4740@cindex aligned instruction bundle
ec82c18e 4741@code{.bundle_align_mode} enables or disables @dfn{aligned instruction
fa94de6b 4742bundle} mode. In this mode, sequences of adjacent instructions are grouped
ec82c18e 4743into fixed-sized @dfn{bundles}. If the argument is zero, this mode is
27dcf5c0 4744disabled (which is the default state). If the argument it not zero, it
fa94de6b
RM
4745gives the size of an instruction bundle as a power of two (as for the
4746@code{.p2align} directive, @pxref{P2align}).
4747
4748For some targets, it's an ABI requirement that no instruction may span a
ec82c18e 4749certain aligned boundary. A @dfn{bundle} is simply a sequence of
fa94de6b
RM
4750instructions that starts on an aligned boundary. For example, if
4751@var{abs-expr} is @code{5} then the bundle size is 32, so each aligned
4752chunk of 32 bytes is a bundle. When aligned instruction bundle mode is in
4753effect, no single instruction may span a boundary between bundles. If an
4754instruction would start too close to the end of a bundle for the length of
4755that particular instruction to fit within the bundle, then the space at the
4756end of that bundle is filled with no-op instructions so the instruction
4757starts in the next bundle. As a corollary, it's an error if any single
4758instruction's encoding is longer than the bundle size.
4759
d3b47e2b 4760@subsection @code{.bundle_lock} and @code{.bundle_unlock}
fa94de6b
RM
4761@cindex @code{bundle_lock} directive
4762@cindex @code{bundle_unlock} directive
4763The @code{.bundle_lock} and directive @code{.bundle_unlock} directives
4764allow explicit control over instruction bundle padding. These directives
4765are only valid when @code{.bundle_align_mode} has been used to enable
4766aligned instruction bundle mode. It's an error if they appear when
4767@code{.bundle_align_mode} has not been used at all, or when the last
4768directive was @w{@code{.bundle_align_mode 0}}.
4769
4770@cindex bundle-locked
4771For some targets, it's an ABI requirement that certain instructions may
4772appear only as part of specified permissible sequences of multiple
4773instructions, all within the same bundle. A pair of @code{.bundle_lock}
ec82c18e 4774and @code{.bundle_unlock} directives define a @dfn{bundle-locked}
fa94de6b
RM
4775instruction sequence. For purposes of aligned instruction bundle mode, a
4776sequence starting with @code{.bundle_lock} and ending with
4777@code{.bundle_unlock} is treated as a single instruction. That is, the
4778entire sequence must fit into a single bundle and may not span a bundle
4779boundary. If necessary, no-op instructions will be inserted before the
4780first instruction of the sequence so that the whole sequence starts on an
4781aligned bundle boundary. It's an error if the sequence is longer than the
4782bundle size.
4783
d416e51d
RM
4784For convenience when using @code{.bundle_lock} and @code{.bundle_unlock}
4785inside assembler macros (@pxref{Macro}), bundle-locked sequences may be
4786nested. That is, a second @code{.bundle_lock} directive before the next
4787@code{.bundle_unlock} directive has no effect except that it must be
4788matched by another closing @code{.bundle_unlock} so that there is the
4789same number of @code{.bundle_lock} and @code{.bundle_unlock} directives.
fa94de6b 4790
252b5132
RH
4791@node Byte
4792@section @code{.byte @var{expressions}}
4793
4794@cindex @code{byte} directive
4795@cindex integers, one byte
4796@code{.byte} expects zero or more expressions, separated by commas.
4797Each expression is assembled into the next byte.
4798
54cfded0 4799@node CFI directives
d3b47e2b
L
4800@section CFI directives
4801@subsection @code{.cfi_sections @var{section_list}}
38462edf
JJ
4802@cindex @code{cfi_sections} directive
4803@code{.cfi_sections} may be used to specify whether CFI directives
4804should emit @code{.eh_frame} section and/or @code{.debug_frame} section.
4805If @var{section_list} is @code{.eh_frame}, @code{.eh_frame} is emitted,
4806if @var{section_list} is @code{.debug_frame}, @code{.debug_frame} is emitted.
4807To emit both use @code{.eh_frame, .debug_frame}. The default if this
4808directive is not used is @code{.cfi_sections .eh_frame}.
4809
2f0c68f2
CM
4810On targets that support compact unwinding tables these can be generated
4811by specifying @code{.eh_frame_entry} instead of @code{.eh_frame}.
4812
bd5608dc
NC
4813Some targets may support an additional name, such as @code{.c6xabi.exidx}
4814which is used by the @value{TIC6X} target.
4815
4816The @code{.cfi_sections} directive can be repeated, with the same or different
4817arguments, provided that CFI generation has not yet started. Once CFI
4818generation has started however the section list is fixed and any attempts to
4819redefine it will result in an error.
4820
d3b47e2b 4821@subsection @code{.cfi_startproc [simple]}
54cfded0
AM
4822@cindex @code{cfi_startproc} directive
4823@code{.cfi_startproc} is used at the beginning of each function that
4824should have an entry in @code{.eh_frame}. It initializes some internal
4b7d318b 4825data structures. Don't forget to close the function by
54cfded0
AM
4826@code{.cfi_endproc}.
4827
01642c12 4828Unless @code{.cfi_startproc} is used along with parameter @code{simple}
4b7d318b 4829it also emits some architecture dependent initial CFI instructions.
01642c12 4830
d3b47e2b 4831@subsection @code{.cfi_endproc}
54cfded0
AM
4832@cindex @code{cfi_endproc} directive
4833@code{.cfi_endproc} is used at the end of a function where it closes its
4834unwind entry previously opened by
b45619c0 4835@code{.cfi_startproc}, and emits it to @code{.eh_frame}.
54cfded0 4836
d3b47e2b 4837@subsection @code{.cfi_personality @var{encoding} [, @var{exp}]}
2f0c68f2 4838@cindex @code{cfi_personality} directive
9b8ae42e
JJ
4839@code{.cfi_personality} defines personality routine and its encoding.
4840@var{encoding} must be a constant determining how the personality
4841should be encoded. If it is 255 (@code{DW_EH_PE_omit}), second
4842argument is not present, otherwise second argument should be
4843a constant or a symbol name. When using indirect encodings,
4844the symbol provided should be the location where personality
4845can be loaded from, not the personality routine itself.
4846The default after @code{.cfi_startproc} is @code{.cfi_personality 0xff},
4847no personality routine.
4848
2f0c68f2
CM
4849@subsection @code{.cfi_personality_id @var{id}}
4850@cindex @code{cfi_personality_id} directive
4851@code{cfi_personality_id} defines a personality routine by its index as
4852defined in a compact unwinding format.
4853Only valid when generating compact EH frames (i.e.
4854with @code{.cfi_sections eh_frame_entry}.
4855
4856@subsection @code{.cfi_fde_data [@var{opcode1} [, @dots{}]]}
4857@cindex @code{cfi_fde_data} directive
4858@code{cfi_fde_data} is used to describe the compact unwind opcodes to be
4859used for the current function. These are emitted inline in the
4860@code{.eh_frame_entry} section if small enough and there is no LSDA, or
4861in the @code{.gnu.extab} section otherwise.
4862Only valid when generating compact EH frames (i.e.
4863with @code{.cfi_sections eh_frame_entry}.
4864
d3b47e2b 4865@subsection @code{.cfi_lsda @var{encoding} [, @var{exp}]}
9b8ae42e
JJ
4866@code{.cfi_lsda} defines LSDA and its encoding.
4867@var{encoding} must be a constant determining how the LSDA
2f0c68f2
CM
4868should be encoded. If it is 255 (@code{DW_EH_PE_omit}), the second
4869argument is not present, otherwise the second argument should be a constant
9b8ae42e 4870or a symbol name. The default after @code{.cfi_startproc} is @code{.cfi_lsda 0xff},
2f0c68f2
CM
4871meaning that no LSDA is present.
4872
4873@subsection @code{.cfi_inline_lsda} [@var{align}]
4874@code{.cfi_inline_lsda} marks the start of a LSDA data section and
4875switches to the corresponding @code{.gnu.extab} section.
4876Must be preceded by a CFI block containing a @code{.cfi_lsda} directive.
4877Only valid when generating compact EH frames (i.e.
4878with @code{.cfi_sections eh_frame_entry}.
4879
4880The table header and unwinding opcodes will be generated at this point,
4881so that they are immediately followed by the LSDA data. The symbol
4882referenced by the @code{.cfi_lsda} directive should still be defined
4883in case a fallback FDE based encoding is used. The LSDA data is terminated
4884by a section directive.
4885
4886The optional @var{align} argument specifies the alignment required.
4887The alignment is specified as a power of two, as with the
4888@code{.p2align} directive.
9b8ae42e 4889
d3b47e2b 4890@subsection @code{.cfi_def_cfa @var{register}, @var{offset}}
01642c12 4891@code{.cfi_def_cfa} defines a rule for computing CFA as: @i{take
54cfded0
AM
4892address from @var{register} and add @var{offset} to it}.
4893
d3b47e2b 4894@subsection @code{.cfi_def_cfa_register @var{register}}
54cfded0
AM
4895@code{.cfi_def_cfa_register} modifies a rule for computing CFA. From
4896now on @var{register} will be used instead of the old one. Offset
4897remains the same.
4898
d3b47e2b 4899@subsection @code{.cfi_def_cfa_offset @var{offset}}
54cfded0
AM
4900@code{.cfi_def_cfa_offset} modifies a rule for computing CFA. Register
4901remains the same, but @var{offset} is new. Note that it is the
4902absolute offset that will be added to a defined register to compute
4903CFA address.
4904
d3b47e2b 4905@subsection @code{.cfi_adjust_cfa_offset @var{offset}}
54cfded0 4906Same as @code{.cfi_def_cfa_offset} but @var{offset} is a relative
33eaf5de 4907value that is added/subtracted from the previous offset.
54cfded0 4908
d3b47e2b 4909@subsection @code{.cfi_offset @var{register}, @var{offset}}
54cfded0 4910Previous value of @var{register} is saved at offset @var{offset} from
01642c12 4911CFA.
54cfded0 4912
084303b8
AK
4913@subsection @code{.cfi_val_offset @var{register}, @var{offset}}
4914Previous value of @var{register} is CFA + @var{offset}.
4915
d3b47e2b 4916@subsection @code{.cfi_rel_offset @var{register}, @var{offset}}
17076204
RH
4917Previous value of @var{register} is saved at offset @var{offset} from
4918the current CFA register. This is transformed to @code{.cfi_offset}
4919using the known displacement of the CFA register from the CFA.
4920This is often easier to use, because the number will match the
4921code it's annotating.
54cfded0 4922
d3b47e2b 4923@subsection @code{.cfi_register @var{register1}, @var{register2}}
4b7d318b
L
4924Previous value of @var{register1} is saved in register @var{register2}.
4925
d3b47e2b 4926@subsection @code{.cfi_restore @var{register}}
01642c12
RM
4927@code{.cfi_restore} says that the rule for @var{register} is now the
4928same as it was at the beginning of the function, after all initial
4b7d318b
L
4929instruction added by @code{.cfi_startproc} were executed.
4930
d3b47e2b 4931@subsection @code{.cfi_undefined @var{register}}
4b7d318b
L
4932From now on the previous value of @var{register} can't be restored anymore.
4933
d3b47e2b 4934@subsection @code{.cfi_same_value @var{register}}
01642c12 4935Current value of @var{register} is the same like in the previous frame,
4b7d318b
L
4936i.e. no restoration needed.
4937
48eac74c
MG
4938@subsection @code{.cfi_remember_state} and @code{.cfi_restore_state}
4939@code{.cfi_remember_state} pushes the set of rules for every register onto an
4940implicit stack, while @code{.cfi_restore_state} pops them off the stack and
4941places them in the current row. This is useful for situations where you have
4942multiple @code{.cfi_*} directives that need to be undone due to the control
4943flow of the program. For example, we could have something like this (assuming
4944the CFA is the value of @code{rbp}):
4945
4946@smallexample
4947 je label
4948 popq %rbx
4949 .cfi_restore %rbx
4950 popq %r12
4951 .cfi_restore %r12
4952 popq %rbp
4953 .cfi_restore %rbp
4954 .cfi_def_cfa %rsp, 8
4955 ret
4956label:
4957 /* Do something else */
4958@end smallexample
4959
4960Here, we want the @code{.cfi} directives to affect only the rows corresponding
4961to the instructions before @code{label}. This means we'd have to add multiple
4962@code{.cfi} directives after @code{label} to recreate the original save
4963locations of the registers, as well as setting the CFA back to the value of
4964@code{rbp}. This would be clumsy, and result in a larger binary size. Instead,
4965we can write:
4966
4967@smallexample
4968 je label
4969 popq %rbx
4970 .cfi_remember_state
4971 .cfi_restore %rbx
4972 popq %r12
4973 .cfi_restore %r12
4974 popq %rbp
4975 .cfi_restore %rbp
4976 .cfi_def_cfa %rsp, 8
4977 ret
4978label:
4979 .cfi_restore_state
4980 /* Do something else */
4981@end smallexample
4982
4983That way, the rules for the instructions after @code{label} will be the same
4984as before the first @code{.cfi_restore} without having to use multiple
4985@code{.cfi} directives.
4b7d318b 4986
d3b47e2b 4987@subsection @code{.cfi_return_column @var{register}}
01642c12 4988Change return column @var{register}, i.e. the return address is either
4b7d318b
L
4989directly in @var{register} or can be accessed by rules for @var{register}.
4990
d3b47e2b 4991@subsection @code{.cfi_signal_frame}
63752a75
JJ
4992Mark current function as signal trampoline.
4993
d3b47e2b 4994@subsection @code{.cfi_window_save}
364b6d8b
JJ
4995SPARC register window has been saved.
4996
d3b47e2b 4997@subsection @code{.cfi_escape} @var{expression}[, @dots{}]
cdfbf930
RH
4998Allows the user to add arbitrary bytes to the unwind info. One
4999might use this to add OS-specific CFI opcodes, or generic CFI
5000opcodes that GAS does not yet support.
252b5132 5001
d3b47e2b 5002@subsection @code{.cfi_val_encoded_addr @var{register}, @var{encoding}, @var{label}}
f1c4cc75
RH
5003The current value of @var{register} is @var{label}. The value of @var{label}
5004will be encoded in the output file according to @var{encoding}; see the
5005description of @code{.cfi_personality} for details on this encoding.
5006
5007The usefulness of equating a register to a fixed label is probably
5008limited to the return address register. Here, it can be useful to
5009mark a code segment that has only one return address which is reached
5010by a direct branch and no copy of the return address exists in memory
5011or another register.
5012
ccf8a69b
BW
5013@node Comm
5014@section @code{.comm @var{symbol} , @var{length} }
bd0eb99b 5015
ccf8a69b
BW
5016@cindex @code{comm} directive
5017@cindex symbol, common
5018@code{.comm} declares a common symbol named @var{symbol}. When linking, a
5019common symbol in one object file may be merged with a defined or common symbol
5020of the same name in another object file. If @code{@value{LD}} does not see a
5021definition for the symbol--just one or more common symbols--then it will
5022allocate @var{length} bytes of uninitialized memory. @var{length} must be an
5023absolute expression. If @code{@value{LD}} sees multiple common symbols with
5024the same name, and they do not all have the same size, it will allocate space
5025using the largest size.
07a53e5c 5026
c1711530
DK
5027@ifset COFF-ELF
5028When using ELF or (as a GNU extension) PE, the @code{.comm} directive takes
01642c12 5029an optional third argument. This is the desired alignment of the symbol,
c1711530
DK
5030specified for ELF as a byte boundary (for example, an alignment of 16 means
5031that the least significant 4 bits of the address should be zero), and for PE
5032as a power of two (for example, an alignment of 5 means aligned to a 32-byte
01642c12 5033boundary). The alignment must be an absolute expression, and it must be a
c1711530 5034power of two. If @code{@value{LD}} allocates uninitialized memory for the
01642c12 5035common symbol, it will use the alignment when placing the symbol. If no
c1711530 5036alignment is specified, @command{@value{AS}} will set the alignment to the
ccf8a69b 5037largest power of two less than or equal to the size of the symbol, up to a
c1711530
DK
5038maximum of 16 on ELF, or the default section alignment of 4 on PE@footnote{This
5039is not the same as the executable image file alignment controlled by @code{@value{LD}}'s
5040@samp{--section-alignment} option; image file sections in PE are aligned to
5041multiples of 4096, which is far too large an alignment for ordinary variables.
5042It is rather the default alignment for (non-debug) sections within object
5043(@samp{*.o}) files, which are less strictly aligned.}.
ccf8a69b 5044@end ifset
cd1fcb49 5045
ccf8a69b
BW
5046@ifset HPPA
5047The syntax for @code{.comm} differs slightly on the HPPA. The syntax is
5048@samp{@var{symbol} .comm, @var{length}}; @var{symbol} is optional.
5049@end ifset
07a53e5c 5050
252b5132
RH
5051@node Data
5052@section @code{.data @var{subsection}}
5053
5054@cindex @code{data} directive
a4fb0134 5055@code{.data} tells @command{@value{AS}} to assemble the following statements onto the
252b5132
RH
5056end of the data subsection numbered @var{subsection} (which is an
5057absolute expression). If @var{subsection} is omitted, it defaults
5058to zero.
5059
5060@ifset COFF
5061@node Def
5062@section @code{.def @var{name}}
5063
5064@cindex @code{def} directive
5065@cindex COFF symbols, debugging
5066@cindex debugging COFF symbols
5067Begin defining debugging information for a symbol @var{name}; the
5068definition extends until the @code{.endef} directive is encountered.
5069@ifset BOUT
5070
a4fb0134 5071This directive is only observed when @command{@value{AS}} is configured for COFF
252b5132
RH
5072format output; when producing @code{b.out}, @samp{.def} is recognized,
5073but ignored.
5074@end ifset
5075@end ifset
5076
5077@ifset aout-bout
5078@node Desc
5079@section @code{.desc @var{symbol}, @var{abs-expression}}
5080
5081@cindex @code{desc} directive
5082@cindex COFF symbol descriptor
5083@cindex symbol descriptor, COFF
5084This directive sets the descriptor of the symbol (@pxref{Symbol Attributes})
5085to the low 16 bits of an absolute expression.
5086
5087@ifset COFF
a4fb0134 5088The @samp{.desc} directive is not available when @command{@value{AS}} is
252b5132 5089configured for COFF output; it is only for @code{a.out} or @code{b.out}
a4fb0134 5090object format. For the sake of compatibility, @command{@value{AS}} accepts
252b5132
RH
5091it, but produces no output, when configured for COFF.
5092@end ifset
5093@end ifset
5094
5095@ifset COFF
5096@node Dim
5097@section @code{.dim}
5098
5099@cindex @code{dim} directive
5100@cindex COFF auxiliary symbol information
5101@cindex auxiliary symbol information, COFF
5102This directive is generated by compilers to include auxiliary debugging
5103information in the symbol table. It is only permitted inside
5104@code{.def}/@code{.endef} pairs.
5105@ifset BOUT
5106
5107@samp{.dim} is only meaningful when generating COFF format output; when
a4fb0134 5108@command{@value{AS}} is generating @code{b.out}, it accepts this directive but
252b5132
RH
5109ignores it.
5110@end ifset
5111@end ifset
5112
5113@node Double
5114@section @code{.double @var{flonums}}
5115
5116@cindex @code{double} directive
5117@cindex floating point numbers (double)
5118@code{.double} expects zero or more flonums, separated by commas. It
5119assembles floating point numbers.
5120@ifset GENERIC
5121The exact kind of floating point numbers emitted depends on how
a4fb0134 5122@command{@value{AS}} is configured. @xref{Machine Dependencies}.
252b5132
RH
5123@end ifset
5124@ifclear GENERIC
5125@ifset IEEEFLOAT
5126On the @value{TARGET} family @samp{.double} emits 64-bit floating-point numbers
5127in @sc{ieee} format.
5128@end ifset
5129@end ifclear
5130
5131@node Eject
5132@section @code{.eject}
5133
5134@cindex @code{eject} directive
5135@cindex new page, in listings
5136@cindex page, in listings
5137@cindex listing control: new page
5138Force a page break at this point, when generating assembly listings.
5139
5140@node Else
5141@section @code{.else}
5142
5143@cindex @code{else} directive
a4fb0134 5144@code{.else} is part of the @command{@value{AS}} support for conditional
96e9638b 5145assembly; see @ref{If,,@code{.if}}. It marks the beginning of a section
252b5132
RH
5146of code to be assembled if the condition for the preceding @code{.if}
5147was false.
5148
3fd9f047
TW
5149@node Elseif
5150@section @code{.elseif}
5151
5152@cindex @code{elseif} directive
a4fb0134 5153@code{.elseif} is part of the @command{@value{AS}} support for conditional
96e9638b 5154assembly; see @ref{If,,@code{.if}}. It is shorthand for beginning a new
3fd9f047
TW
5155@code{.if} block that would otherwise fill the entire @code{.else} section.
5156
252b5132
RH
5157@node End
5158@section @code{.end}
5159
5160@cindex @code{end} directive
a4fb0134 5161@code{.end} marks the end of the assembly file. @command{@value{AS}} does not
252b5132
RH
5162process anything in the file past the @code{.end} directive.
5163
5164@ifset COFF
5165@node Endef
5166@section @code{.endef}
5167
5168@cindex @code{endef} directive
5169This directive flags the end of a symbol definition begun with
5170@code{.def}.
5171@ifset BOUT
5172
5173@samp{.endef} is only meaningful when generating COFF format output; if
a4fb0134 5174@command{@value{AS}} is configured to generate @code{b.out}, it accepts this
252b5132
RH
5175directive but ignores it.
5176@end ifset
5177@end ifset
5178
5179@node Endfunc
5180@section @code{.endfunc}
5181@cindex @code{endfunc} directive
5182@code{.endfunc} marks the end of a function specified with @code{.func}.
5183
5184@node Endif
5185@section @code{.endif}
5186
5187@cindex @code{endif} directive
a4fb0134 5188@code{.endif} is part of the @command{@value{AS}} support for conditional assembly;
252b5132
RH
5189it marks the end of a block of code that is only assembled
5190conditionally. @xref{If,,@code{.if}}.
5191
5192@node Equ
5193@section @code{.equ @var{symbol}, @var{expression}}
5194
5195@cindex @code{equ} directive
5196@cindex assigning values to symbols
5197@cindex symbols, assigning values to
5198This directive sets the value of @var{symbol} to @var{expression}.
96e9638b 5199It is synonymous with @samp{.set}; see @ref{Set,,@code{.set}}.
252b5132
RH
5200
5201@ifset HPPA
01642c12 5202The syntax for @code{equ} on the HPPA is
252b5132
RH
5203@samp{@var{symbol} .equ @var{expression}}.
5204@end ifset
5205
3c9b82ba 5206@ifset Z80
01642c12
RM
5207The syntax for @code{equ} on the Z80 is
5208@samp{@var{symbol} equ @var{expression}}.
33eaf5de 5209On the Z80 it is an error if @var{symbol} is already defined,
01642c12 5210but the symbol is not protected from later redefinition.
96e9638b 5211Compare @ref{Equiv}.
3c9b82ba
NC
5212@end ifset
5213
252b5132
RH
5214@node Equiv
5215@section @code{.equiv @var{symbol}, @var{expression}}
5216@cindex @code{equiv} directive
5217The @code{.equiv} directive is like @code{.equ} and @code{.set}, except that
8dfa0188
NC
5218the assembler will signal an error if @var{symbol} is already defined. Note a
5219symbol which has been referenced but not actually defined is considered to be
5220undefined.
252b5132 5221
01642c12 5222Except for the contents of the error message, this is roughly equivalent to
252b5132
RH
5223@smallexample
5224.ifdef SYM
5225.err
5226.endif
5227.equ SYM,VAL
5228@end smallexample
9497f5ac
NC
5229plus it protects the symbol from later redefinition.
5230
5231@node Eqv
5232@section @code{.eqv @var{symbol}, @var{expression}}
5233@cindex @code{eqv} directive
5234The @code{.eqv} directive is like @code{.equiv}, but no attempt is made to
5235evaluate the expression or any part of it immediately. Instead each time
5236the resulting symbol is used in an expression, a snapshot of its current
5237value is taken.
252b5132
RH
5238
5239@node Err
5240@section @code{.err}
5241@cindex @code{err} directive
a4fb0134
SC
5242If @command{@value{AS}} assembles a @code{.err} directive, it will print an error
5243message and, unless the @option{-Z} option was used, it will not generate an
f9eb6721 5244object file. This can be used to signal an error in conditionally compiled code.
252b5132 5245
d190d046
HPN
5246@node Error
5247@section @code{.error "@var{string}"}
5248@cindex error directive
5249
5250Similarly to @code{.err}, this directive emits an error, but you can specify a
5251string that will be emitted as the error message. If you don't specify the
5252message, it defaults to @code{".error directive invoked in source file"}.
5253@xref{Errors, ,Error and Warning Messages}.
5254
5255@smallexample
5256 .error "This code has not been assembled and tested."
5257@end smallexample
5258
252b5132
RH
5259@node Exitm
5260@section @code{.exitm}
5261Exit early from the current macro definition. @xref{Macro}.
5262
5263@node Extern
5264@section @code{.extern}
5265
5266@cindex @code{extern} directive
5267@code{.extern} is accepted in the source program---for compatibility
a4fb0134 5268with other assemblers---but it is ignored. @command{@value{AS}} treats
252b5132
RH
5269all undefined symbols as external.
5270
5271@node Fail
5272@section @code{.fail @var{expression}}
5273
5274@cindex @code{fail} directive
5275Generates an error or a warning. If the value of the @var{expression} is 500
a4fb0134
SC
5276or more, @command{@value{AS}} will print a warning message. If the value is less
5277than 500, @command{@value{AS}} will print an error message. The message will
252b5132
RH
5278include the value of @var{expression}. This can occasionally be useful inside
5279complex nested macros or conditional assembly.
5280
252b5132 5281@node File
14082c76 5282@section @code{.file}
252b5132 5283@cindex @code{file} directive
14082c76
BW
5284
5285@ifclear no-file-dir
5286There are two different versions of the @code{.file} directive. Targets
5287that support DWARF2 line number information use the DWARF2 version of
5288@code{.file}. Other targets use the default version.
5289
5290@subheading Default Version
5291
252b5132
RH
5292@cindex logical file name
5293@cindex file name, logical
14082c76
BW
5294This version of the @code{.file} directive tells @command{@value{AS}} that we
5295are about to start a new logical file. The syntax is:
5296
5297@smallexample
5298.file @var{string}
5299@end smallexample
5300
5301@var{string} is the new file name. In general, the filename is
252b5132
RH
5302recognized whether or not it is surrounded by quotes @samp{"}; but if you wish
5303to specify an empty file name, you must give the quotes--@code{""}. This
5304statement may go away in future: it is only recognized to be compatible with
a4fb0134 5305old @command{@value{AS}} programs.
14082c76
BW
5306
5307@subheading DWARF2 Version
252b5132
RH
5308@end ifclear
5309
14082c76
BW
5310When emitting DWARF2 line number information, @code{.file} assigns filenames
5311to the @code{.debug_line} file name table. The syntax is:
5312
5313@smallexample
5314.file @var{fileno} @var{filename}
5315@end smallexample
5316
5317The @var{fileno} operand should be a unique positive integer to use as the
5318index of the entry in the table. The @var{filename} operand is a C string
5319literal.
5320
5321The detail of filename indices is exposed to the user because the filename
5322table is shared with the @code{.debug_info} section of the DWARF2 debugging
5323information, and thus the user must know the exact indices that table
5324entries will have.
5325
252b5132
RH
5326@node Fill
5327@section @code{.fill @var{repeat} , @var{size} , @var{value}}
5328
5329@cindex @code{fill} directive
5330@cindex writing patterns in memory
5331@cindex patterns, writing in memory
bc64be0c 5332@var{repeat}, @var{size} and @var{value} are absolute expressions.
252b5132
RH
5333This emits @var{repeat} copies of @var{size} bytes. @var{Repeat}
5334may be zero or more. @var{Size} may be zero or more, but if it is
5335more than 8, then it is deemed to have the value 8, compatible with
5336other people's assemblers. The contents of each @var{repeat} bytes
5337is taken from an 8-byte number. The highest order 4 bytes are
5338zero. The lowest order 4 bytes are @var{value} rendered in the
a4fb0134 5339byte-order of an integer on the computer @command{@value{AS}} is assembling for.
252b5132
RH
5340Each @var{size} bytes in a repetition is taken from the lowest order
5341@var{size} bytes of this number. Again, this bizarre behavior is
5342compatible with other people's assemblers.
5343
5344@var{size} and @var{value} are optional.
5345If the second comma and @var{value} are absent, @var{value} is
5346assumed zero. If the first comma and following tokens are absent,
5347@var{size} is assumed to be 1.
5348
5349@node Float
5350@section @code{.float @var{flonums}}
5351
5352@cindex floating point numbers (single)
5353@cindex @code{float} directive
5354This directive assembles zero or more flonums, separated by commas. It
5355has the same effect as @code{.single}.
5356@ifset GENERIC
5357The exact kind of floating point numbers emitted depends on how
a4fb0134 5358@command{@value{AS}} is configured.
252b5132
RH
5359@xref{Machine Dependencies}.
5360@end ifset
5361@ifclear GENERIC
5362@ifset IEEEFLOAT
5363On the @value{TARGET} family, @code{.float} emits 32-bit floating point numbers
5364in @sc{ieee} format.
5365@end ifset
5366@end ifclear
5367
5368@node Func
5369@section @code{.func @var{name}[,@var{label}]}
5370@cindex @code{func} directive
5371@code{.func} emits debugging information to denote function @var{name}, and
5372is ignored unless the file is assembled with debugging enabled.
05da4302 5373Only @samp{--gstabs[+]} is currently supported.
252b5132
RH
5374@var{label} is the entry point of the function and if omitted @var{name}
5375prepended with the @samp{leading char} is used.
5376@samp{leading char} is usually @code{_} or nothing, depending on the target.
5377All functions are currently defined to have @code{void} return type.
5378The function must be terminated with @code{.endfunc}.
5379
5380@node Global
5381@section @code{.global @var{symbol}}, @code{.globl @var{symbol}}
5382
5383@cindex @code{global} directive
5384@cindex symbol, making visible to linker
5385@code{.global} makes the symbol visible to @code{@value{LD}}. If you define
5386@var{symbol} in your partial program, its value is made available to
5387other partial programs that are linked with it. Otherwise,
5388@var{symbol} takes its attributes from a symbol of the same name
5389from another file linked into the same program.
5390
5391Both spellings (@samp{.globl} and @samp{.global}) are accepted, for
5392compatibility with other assemblers.
5393
5394@ifset HPPA
5395On the HPPA, @code{.global} is not always enough to make it accessible to other
5396partial programs. You may need the HPPA-only @code{.EXPORT} directive as well.
96e9638b 5397@xref{HPPA Directives, ,HPPA Assembler Directives}.
252b5132
RH
5398@end ifset
5399
c91d2e08 5400@ifset ELF
3a99f02f
DJ
5401@node Gnu_attribute
5402@section @code{.gnu_attribute @var{tag},@var{value}}
5403Record a @sc{gnu} object attribute for this file. @xref{Object Attributes}.
5404
c91d2e08
NC
5405@node Hidden
5406@section @code{.hidden @var{names}}
5407
c1253627
NC
5408@cindex @code{hidden} directive
5409@cindex visibility
ed9589d4 5410This is one of the ELF visibility directives. The other two are
01642c12 5411@code{.internal} (@pxref{Internal,,@code{.internal}}) and
a349d9dd 5412@code{.protected} (@pxref{Protected,,@code{.protected}}).
c91d2e08
NC
5413
5414This directive overrides the named symbols default visibility (which is set by
5415their binding: local, global or weak). The directive sets the visibility to
5416@code{hidden} which means that the symbols are not visible to other components.
01642c12 5417Such symbols are always considered to be @code{protected} as well.
c91d2e08
NC
5418@end ifset
5419
252b5132
RH
5420@node hword
5421@section @code{.hword @var{expressions}}
5422
5423@cindex @code{hword} directive
5424@cindex integers, 16-bit
5425@cindex numbers, 16-bit
5426@cindex sixteen bit integers
5427This expects zero or more @var{expressions}, and emits
5428a 16 bit number for each.
5429
5430@ifset GENERIC
5431This directive is a synonym for @samp{.short}; depending on the target
5432architecture, it may also be a synonym for @samp{.word}.
5433@end ifset
5434@ifclear GENERIC
5435@ifset W32
5436This directive is a synonym for @samp{.short}.
5437@end ifset
5438@ifset W16
5439This directive is a synonym for both @samp{.short} and @samp{.word}.
5440@end ifset
5441@end ifclear
5442
5443@node Ident
5444@section @code{.ident}
5445
5446@cindex @code{ident} directive
cb4c78d6
BE
5447
5448This directive is used by some assemblers to place tags in object files. The
5449behavior of this directive varies depending on the target. When using the
5450a.out object file format, @command{@value{AS}} simply accepts the directive for
5451source-file compatibility with existing assemblers, but does not emit anything
5452for it. When using COFF, comments are emitted to the @code{.comment} or
5453@code{.rdata} section, depending on the target. When using ELF, comments are
5454emitted to the @code{.comment} section.
252b5132
RH
5455
5456@node If
5457@section @code{.if @var{absolute expression}}
5458
5459@cindex conditional assembly
5460@cindex @code{if} directive
5461@code{.if} marks the beginning of a section of code which is only
5462considered part of the source program being assembled if the argument
5463(which must be an @var{absolute expression}) is non-zero. The end of
5464the conditional section of code must be marked by @code{.endif}
5465(@pxref{Endif,,@code{.endif}}); optionally, you may include code for the
5466alternative condition, flagged by @code{.else} (@pxref{Else,,@code{.else}}).
3fd9f047
TW
5467If you have several conditions to check, @code{.elseif} may be used to avoid
5468nesting blocks if/else within each subsequent @code{.else} block.
252b5132
RH
5469
5470The following variants of @code{.if} are also supported:
5471@table @code
5472@cindex @code{ifdef} directive
5473@item .ifdef @var{symbol}
5474Assembles the following section of code if the specified @var{symbol}
8dfa0188
NC
5475has been defined. Note a symbol which has been referenced but not yet defined
5476is considered to be undefined.
252b5132 5477
26aca5f6
JB
5478@cindex @code{ifb} directive
5479@item .ifb @var{text}
5480Assembles the following section of code if the operand is blank (empty).
5481
252b5132
RH
5482@cindex @code{ifc} directive
5483@item .ifc @var{string1},@var{string2}
5484Assembles the following section of code if the two strings are the same. The
5485strings may be optionally quoted with single quotes. If they are not quoted,
5486the first string stops at the first comma, and the second string stops at the
5487end of the line. Strings which contain whitespace should be quoted. The
5488string comparison is case sensitive.
5489
5490@cindex @code{ifeq} directive
5491@item .ifeq @var{absolute expression}
5492Assembles the following section of code if the argument is zero.
5493
5494@cindex @code{ifeqs} directive
5495@item .ifeqs @var{string1},@var{string2}
5496Another form of @code{.ifc}. The strings must be quoted using double quotes.
5497
5498@cindex @code{ifge} directive
5499@item .ifge @var{absolute expression}
5500Assembles the following section of code if the argument is greater than or
5501equal to zero.
5502
5503@cindex @code{ifgt} directive
5504@item .ifgt @var{absolute expression}
5505Assembles the following section of code if the argument is greater than zero.
5506
5507@cindex @code{ifle} directive
5508@item .ifle @var{absolute expression}
5509Assembles the following section of code if the argument is less than or equal
5510to zero.
5511
5512@cindex @code{iflt} directive
5513@item .iflt @var{absolute expression}
5514Assembles the following section of code if the argument is less than zero.
5515
26aca5f6
JB
5516@cindex @code{ifnb} directive
5517@item .ifnb @var{text}
5518Like @code{.ifb}, but the sense of the test is reversed: this assembles the
5519following section of code if the operand is non-blank (non-empty).
5520
252b5132
RH
5521@cindex @code{ifnc} directive
5522@item .ifnc @var{string1},@var{string2}.
5523Like @code{.ifc}, but the sense of the test is reversed: this assembles the
5524following section of code if the two strings are not the same.
5525
5526@cindex @code{ifndef} directive
5527@cindex @code{ifnotdef} directive
5528@item .ifndef @var{symbol}
5529@itemx .ifnotdef @var{symbol}
5530Assembles the following section of code if the specified @var{symbol}
8dfa0188
NC
5531has not been defined. Both spelling variants are equivalent. Note a symbol
5532which has been referenced but not yet defined is considered to be undefined.
252b5132
RH
5533
5534@cindex @code{ifne} directive
5535@item .ifne @var{absolute expression}
5536Assembles the following section of code if the argument is not equal to zero
5537(in other words, this is equivalent to @code{.if}).
5538
5539@cindex @code{ifnes} directive
5540@item .ifnes @var{string1},@var{string2}
5541Like @code{.ifeqs}, but the sense of the test is reversed: this assembles the
5542following section of code if the two strings are not the same.
5543@end table
5544
7e005732
NC
5545@node Incbin
5546@section @code{.incbin "@var{file}"[,@var{skip}[,@var{count}]]}
5547
5548@cindex @code{incbin} directive
5549@cindex binary files, including
5550The @code{incbin} directive includes @var{file} verbatim at the current
5551location. You can control the search paths used with the @samp{-I} command-line
5552option (@pxref{Invoking,,Command-Line Options}). Quotation marks are required
5553around @var{file}.
5554
5555The @var{skip} argument skips a number of bytes from the start of the
5556@var{file}. The @var{count} argument indicates the maximum number of bytes to
15dcfbc3
NC
5557read. Note that the data is not aligned in any way, so it is the user's
5558responsibility to make sure that proper alignment is provided both before and
5559after the @code{incbin} directive.
7e005732 5560
252b5132
RH
5561@node Include
5562@section @code{.include "@var{file}"}
5563
5564@cindex @code{include} directive
5565@cindex supporting files, including
5566@cindex files, including
5567This directive provides a way to include supporting files at specified
5568points in your source program. The code from @var{file} is assembled as
5569if it followed the point of the @code{.include}; when the end of the
5570included file is reached, assembly of the original file continues. You
5571can control the search paths used with the @samp{-I} command-line option
5572(@pxref{Invoking,,Command-Line Options}). Quotation marks are required
5573around @var{file}.
5574
5575@node Int
5576@section @code{.int @var{expressions}}
5577
5578@cindex @code{int} directive
5579@cindex integers, 32-bit
5580Expect zero or more @var{expressions}, of any section, separated by commas.
5581For each expression, emit a number that, at run time, is the value of that
5582expression. The byte order and bit size of the number depends on what kind
5583of target the assembly is for.
5584
5585@ifclear GENERIC
5586@ifset H8
7be1c489 5587On most forms of the H8/300, @code{.int} emits 16-bit
c2dcd04e 5588integers. On the H8/300H and the Renesas SH, however, @code{.int} emits
252b5132
RH
558932-bit integers.
5590@end ifset
5591@end ifclear
5592
c91d2e08
NC
5593@ifset ELF
5594@node Internal
5595@section @code{.internal @var{names}}
5596
c1253627
NC
5597@cindex @code{internal} directive
5598@cindex visibility
ed9589d4 5599This is one of the ELF visibility directives. The other two are
01642c12 5600@code{.hidden} (@pxref{Hidden,,@code{.hidden}}) and
a349d9dd 5601@code{.protected} (@pxref{Protected,,@code{.protected}}).
c91d2e08
NC
5602
5603This directive overrides the named symbols default visibility (which is set by
5604their binding: local, global or weak). The directive sets the visibility to
5605@code{internal} which means that the symbols are considered to be @code{hidden}
c1253627 5606(i.e., not visible to other components), and that some extra, processor specific
c91d2e08
NC
5607processing must also be performed upon the symbols as well.
5608@end ifset
5609
252b5132
RH
5610@node Irp
5611@section @code{.irp @var{symbol},@var{values}}@dots{}
5612
5613@cindex @code{irp} directive
5614Evaluate a sequence of statements assigning different values to @var{symbol}.
5615The sequence of statements starts at the @code{.irp} directive, and is
5616terminated by an @code{.endr} directive. For each @var{value}, @var{symbol} is
5617set to @var{value}, and the sequence of statements is assembled. If no
5618@var{value} is listed, the sequence of statements is assembled once, with
5619@var{symbol} set to the null string. To refer to @var{symbol} within the
5620sequence of statements, use @var{\symbol}.
5621
5622For example, assembling
5623
5624@example
5625 .irp param,1,2,3
5626 move d\param,sp@@-
5627 .endr
5628@end example
5629
5630is equivalent to assembling
5631
5632@example
5633 move d1,sp@@-
5634 move d2,sp@@-
5635 move d3,sp@@-
5636@end example
5637
96e9638b 5638For some caveats with the spelling of @var{symbol}, see also @ref{Macro}.
5e75c3ab 5639
252b5132
RH
5640@node Irpc
5641@section @code{.irpc @var{symbol},@var{values}}@dots{}
5642
5643@cindex @code{irpc} directive
5644Evaluate a sequence of statements assigning different values to @var{symbol}.
5645The sequence of statements starts at the @code{.irpc} directive, and is
5646terminated by an @code{.endr} directive. For each character in @var{value},
5647@var{symbol} is set to the character, and the sequence of statements is
5648assembled. If no @var{value} is listed, the sequence of statements is
5649assembled once, with @var{symbol} set to the null string. To refer to
5650@var{symbol} within the sequence of statements, use @var{\symbol}.
5651
5652For example, assembling
5653
5654@example
5655 .irpc param,123
5656 move d\param,sp@@-
5657 .endr
5658@end example
5659
5660is equivalent to assembling
5661
5662@example
5663 move d1,sp@@-
5664 move d2,sp@@-
5665 move d3,sp@@-
5666@end example
5667
5e75c3ab
JB
5668For some caveats with the spelling of @var{symbol}, see also the discussion
5669at @xref{Macro}.
5670
252b5132
RH
5671@node Lcomm
5672@section @code{.lcomm @var{symbol} , @var{length}}
5673
5674@cindex @code{lcomm} directive
5675@cindex local common symbols
5676@cindex symbols, local common
5677Reserve @var{length} (an absolute expression) bytes for a local common
5678denoted by @var{symbol}. The section and value of @var{symbol} are
5679those of the new local common. The addresses are allocated in the bss
5680section, so that at run-time the bytes start off zeroed. @var{Symbol}
5681is not declared global (@pxref{Global,,@code{.global}}), so is normally
5682not visible to @code{@value{LD}}.
5683
5684@ifset GENERIC
5685Some targets permit a third argument to be used with @code{.lcomm}. This
5686argument specifies the desired alignment of the symbol in the bss section.
5687@end ifset
5688
5689@ifset HPPA
5690The syntax for @code{.lcomm} differs slightly on the HPPA. The syntax is
5691@samp{@var{symbol} .lcomm, @var{length}}; @var{symbol} is optional.
5692@end ifset
5693
5694@node Lflags
5695@section @code{.lflags}
5696
5697@cindex @code{lflags} directive (ignored)
a4fb0134 5698@command{@value{AS}} accepts this directive, for compatibility with other
252b5132
RH
5699assemblers, but ignores it.
5700
5701@ifclear no-line-dir
5702@node Line
5703@section @code{.line @var{line-number}}
5704
5705@cindex @code{line} directive
252b5132
RH
5706@cindex logical line number
5707@ifset aout-bout
5708Change the logical line number. @var{line-number} must be an absolute
5709expression. The next line has that logical line number. Therefore any other
5710statements on the current line (after a statement separator character) are
5711reported as on logical line number @var{line-number} @minus{} 1. One day
a4fb0134 5712@command{@value{AS}} will no longer support this directive: it is recognized only
252b5132 5713for compatibility with existing assembler programs.
252b5132
RH
5714@end ifset
5715
252b5132 5716Even though this is a directive associated with the @code{a.out} or
a4fb0134 5717@code{b.out} object-code formats, @command{@value{AS}} still recognizes it
252b5132
RH
5718when producing COFF output, and treats @samp{.line} as though it
5719were the COFF @samp{.ln} @emph{if} it is found outside a
5720@code{.def}/@code{.endef} pair.
5721
5722Inside a @code{.def}, @samp{.line} is, instead, one of the directives
5723used by compilers to generate auxiliary symbol information for
5724debugging.
5725@end ifclear
5726
5727@node Linkonce
5728@section @code{.linkonce [@var{type}]}
5729@cindex COMDAT
5730@cindex @code{linkonce} directive
5731@cindex common sections
5732Mark the current section so that the linker only includes a single copy of it.
5733This may be used to include the same section in several different object files,
5734but ensure that the linker will only include it once in the final output file.
5735The @code{.linkonce} pseudo-op must be used for each instance of the section.
5736Duplicate sections are detected based on the section name, so it should be
5737unique.
5738
5739This directive is only supported by a few object file formats; as of this
5740writing, the only object file format which supports it is the Portable
5741Executable format used on Windows NT.
5742
5743The @var{type} argument is optional. If specified, it must be one of the
5744following strings. For example:
5745@smallexample
5746.linkonce same_size
5747@end smallexample
5748Not all types may be supported on all object file formats.
5749
5750@table @code
5751@item discard
5752Silently discard duplicate sections. This is the default.
5753
5754@item one_only
5755Warn if there are duplicate sections, but still keep only one copy.
5756
5757@item same_size
5758Warn if any of the duplicates have different sizes.
5759
5760@item same_contents
5761Warn if any of the duplicates do not have exactly the same contents.
5762@end table
5763
ccf8a69b
BW
5764@node List
5765@section @code{.list}
5766
5767@cindex @code{list} directive
5768@cindex listing control, turning on
5769Control (in conjunction with the @code{.nolist} directive) whether or
5770not assembly listings are generated. These two directives maintain an
5771internal counter (which is zero initially). @code{.list} increments the
5772counter, and @code{.nolist} decrements it. Assembly listings are
5773generated whenever the counter is greater than zero.
5774
5775By default, listings are disabled. When you enable them (with the
5776@samp{-a} command line option; @pxref{Invoking,,Command-Line Options}),
5777the initial value of the listing counter is one.
5778
252b5132
RH
5779@node Ln
5780@section @code{.ln @var{line-number}}
5781
5782@cindex @code{ln} directive
5783@ifclear no-line-dir
5784@samp{.ln} is a synonym for @samp{.line}.
5785@end ifclear
5786@ifset no-line-dir
a4fb0134 5787Tell @command{@value{AS}} to change the logical line number. @var{line-number}
252b5132
RH
5788must be an absolute expression. The next line has that logical
5789line number, so any other statements on the current line (after a
5790statement separator character @code{;}) are reported as on logical
5791line number @var{line-number} @minus{} 1.
5792@ifset BOUT
5793
a4fb0134 5794This directive is accepted, but ignored, when @command{@value{AS}} is
252b5132
RH
5795configured for @code{b.out}; its effect is only associated with COFF
5796output format.
5797@end ifset
5798@end ifset
5799
ccf8a69b
BW
5800@node Loc
5801@section @code{.loc @var{fileno} @var{lineno} [@var{column}] [@var{options}]}
5802@cindex @code{loc} directive
5803When emitting DWARF2 line number information,
5804the @code{.loc} directive will add a row to the @code{.debug_line} line
5805number matrix corresponding to the immediately following assembly
5806instruction. The @var{fileno}, @var{lineno}, and optional @var{column}
5807arguments will be applied to the @code{.debug_line} state machine before
5808the row is added.
252b5132 5809
ccf8a69b
BW
5810The @var{options} are a sequence of the following tokens in any order:
5811
5812@table @code
5813@item basic_block
5814This option will set the @code{basic_block} register in the
5815@code{.debug_line} state machine to @code{true}.
5816
5817@item prologue_end
5818This option will set the @code{prologue_end} register in the
5819@code{.debug_line} state machine to @code{true}.
5820
5821@item epilogue_begin
5822This option will set the @code{epilogue_begin} register in the
5823@code{.debug_line} state machine to @code{true}.
5824
5825@item is_stmt @var{value}
5826This option will set the @code{is_stmt} register in the
01642c12 5827@code{.debug_line} state machine to @code{value}, which must be
ccf8a69b
BW
5828either 0 or 1.
5829
5830@item isa @var{value}
5831This directive will set the @code{isa} register in the @code{.debug_line}
5832state machine to @var{value}, which must be an unsigned integer.
5833
92846e72
CC
5834@item discriminator @var{value}
5835This directive will set the @code{discriminator} register in the @code{.debug_line}
5836state machine to @var{value}, which must be an unsigned integer.
5837
ba8826a8
AO
5838@item view @var{value}
5839This option causes a row to be added to @code{.debug_line} in reference to the
5840current address (which might not be the same as that of the following assembly
5841instruction), and to associate @var{value} with the @code{view} register in the
5842@code{.debug_line} state machine. If @var{value} is a label, both the
5843@code{view} register and the label are set to the number of prior @code{.loc}
5844directives at the same program location. If @var{value} is the literal
5845@code{0}, the @code{view} register is set to zero, and the assembler asserts
5846that there aren't any prior @code{.loc} directives at the same program
5847location. If @var{value} is the literal @code{-0}, the assembler arrange for
5848the @code{view} register to be reset in this row, even if there are prior
5849@code{.loc} directives at the same program location.
5850
ccf8a69b
BW
5851@end table
5852
5853@node Loc_mark_labels
5854@section @code{.loc_mark_labels @var{enable}}
5855@cindex @code{loc_mark_labels} directive
5856When emitting DWARF2 line number information,
5857the @code{.loc_mark_labels} directive makes the assembler emit an entry
5858to the @code{.debug_line} line number matrix with the @code{basic_block}
5859register in the state machine set whenever a code label is seen.
5860The @var{enable} argument should be either 1 or 0, to enable or disable
5861this function respectively.
252b5132 5862
4d4175af
BW
5863@ifset ELF
5864@node Local
5865@section @code{.local @var{names}}
5866
5867@cindex @code{local} directive
5868This directive, which is available for ELF targets, marks each symbol in
5869the comma-separated list of @code{names} as a local symbol so that it
5870will not be externally visible. If the symbols do not already exist,
5871they will be created.
5872
5873For targets where the @code{.lcomm} directive (@pxref{Lcomm}) does not
5874accept an alignment argument, which is the case for most ELF targets,
5875the @code{.local} directive can be used in combination with @code{.comm}
5876(@pxref{Comm}) to define aligned local common data.
5877@end ifset
5878
252b5132
RH
5879@node Long
5880@section @code{.long @var{expressions}}
5881
5882@cindex @code{long} directive
96e9638b 5883@code{.long} is the same as @samp{.int}. @xref{Int,,@code{.int}}.
252b5132
RH
5884
5885@ignore
5886@c no one seems to know what this is for or whether this description is
5887@c what it really ought to do
5888@node Lsym
5889@section @code{.lsym @var{symbol}, @var{expression}}
5890
5891@cindex @code{lsym} directive
5892@cindex symbol, not referenced in assembly
5893@code{.lsym} creates a new symbol named @var{symbol}, but does not put it in
5894the hash table, ensuring it cannot be referenced by name during the
5895rest of the assembly. This sets the attributes of the symbol to be
5896the same as the expression value:
5897@smallexample
5898@var{other} = @var{descriptor} = 0
5899@var{type} = @r{(section of @var{expression})}
5900@var{value} = @var{expression}
5901@end smallexample
5902@noindent
5903The new symbol is not flagged as external.
5904@end ignore
5905
5906@node Macro
5907@section @code{.macro}
5908
5909@cindex macros
5910The commands @code{.macro} and @code{.endm} allow you to define macros that
5911generate assembly output. For example, this definition specifies a macro
5912@code{sum} that puts a sequence of numbers into memory:
5913
5914@example
5915 .macro sum from=0, to=5
5916 .long \from
5917 .if \to-\from
5918 sum "(\from+1)",\to
5919 .endif
5920 .endm
5921@end example
5922
5923@noindent
5924With that definition, @samp{SUM 0,5} is equivalent to this assembly input:
5925
5926@example
5927 .long 0
5928 .long 1
5929 .long 2
5930 .long 3
5931 .long 4
5932 .long 5
5933@end example
5934
5935@ftable @code
5936@item .macro @var{macname}
5937@itemx .macro @var{macname} @var{macargs} @dots{}
5938@cindex @code{macro} directive
5939Begin the definition of a macro called @var{macname}. If your macro
5940definition requires arguments, specify their names after the macro name,
6eaeac8a
JB
5941separated by commas or spaces. You can qualify the macro argument to
5942indicate whether all invocations must specify a non-blank value (through
5943@samp{:@code{req}}), or whether it takes all of the remaining arguments
5944(through @samp{:@code{vararg}}). You can supply a default value for any
fffeaa5f
JB
5945macro argument by following the name with @samp{=@var{deflt}}. You
5946cannot define two macros with the same @var{macname} unless it has been
96e9638b 5947subject to the @code{.purgem} directive (@pxref{Purgem}) between the two
fffeaa5f 5948definitions. For example, these are all valid @code{.macro} statements:
252b5132
RH
5949
5950@table @code
5951@item .macro comm
5952Begin the definition of a macro called @code{comm}, which takes no
5953arguments.
5954
6258339f 5955@item .macro plus1 p, p1
252b5132
RH
5956@itemx .macro plus1 p p1
5957Either statement begins the definition of a macro called @code{plus1},
5958which takes two arguments; within the macro definition, write
5959@samp{\p} or @samp{\p1} to evaluate the arguments.
5960
5961@item .macro reserve_str p1=0 p2
5962Begin the definition of a macro called @code{reserve_str}, with two
5963arguments. The first argument has a default value, but not the second.
5964After the definition is complete, you can call the macro either as
5965@samp{reserve_str @var{a},@var{b}} (with @samp{\p1} evaluating to
5966@var{a} and @samp{\p2} evaluating to @var{b}), or as @samp{reserve_str
5967,@var{b}} (with @samp{\p1} evaluating as the default, in this case
5968@samp{0}, and @samp{\p2} evaluating to @var{b}).
252b5132 5969
6eaeac8a
JB
5970@item .macro m p1:req, p2=0, p3:vararg
5971Begin the definition of a macro called @code{m}, with at least three
5972arguments. The first argument must always have a value specified, but
5973not the second, which instead has a default value. The third formal
5974will get assigned all remaining arguments specified at invocation time.
5975
252b5132
RH
5976When you call a macro, you can specify the argument values either by
5977position, or by keyword. For example, @samp{sum 9,17} is equivalent to
5978@samp{sum to=17, from=9}.
5979
6258339f
NC
5980@end table
5981
5e75c3ab
JB
5982Note that since each of the @var{macargs} can be an identifier exactly
5983as any other one permitted by the target architecture, there may be
5984occasional problems if the target hand-crafts special meanings to certain
6258339f 5985characters when they occur in a special position. For example, if the colon
5e75c3ab 5986(@code{:}) is generally permitted to be part of a symbol name, but the
6258339f 5987architecture specific code special-cases it when occurring as the final
5e75c3ab
JB
5988character of a symbol (to denote a label), then the macro parameter
5989replacement code will have no way of knowing that and consider the whole
5990construct (including the colon) an identifier, and check only this
6258339f
NC
5991identifier for being the subject to parameter substitution. So for example
5992this macro definition:
5993
5994@example
5995 .macro label l
5996\l:
5997 .endm
5998@end example
5999
6000might not work as expected. Invoking @samp{label foo} might not create a label
6001called @samp{foo} but instead just insert the text @samp{\l:} into the
6002assembler source, probably generating an error about an unrecognised
6003identifier.
6004
6005Similarly problems might occur with the period character (@samp{.})
6006which is often allowed inside opcode names (and hence identifier names). So
6007for example constructing a macro to build an opcode from a base name and a
6008length specifier like this:
6009
6010@example
6011 .macro opcode base length
6012 \base.\length
6013 .endm
6014@end example
6015
6016and invoking it as @samp{opcode store l} will not create a @samp{store.l}
6017instruction but instead generate some kind of error as the assembler tries to
6018interpret the text @samp{\base.\length}.
6019
6020There are several possible ways around this problem:
6021
6022@table @code
6023@item Insert white space
6024If it is possible to use white space characters then this is the simplest
6025solution. eg:
6026
6027@example
6028 .macro label l
6029\l :
6030 .endm
6031@end example
6032
6033@item Use @samp{\()}
6034The string @samp{\()} can be used to separate the end of a macro argument from
6035the following text. eg:
6036
6037@example
6038 .macro opcode base length
6039 \base\().\length
6040 .endm
6041@end example
6042
6043@item Use the alternate macro syntax mode
6044In the alternative macro syntax mode the ampersand character (@samp{&}) can be
6045used as a separator. eg:
5e75c3ab
JB
6046
6047@example
6048 .altmacro
6049 .macro label l
6050l&:
6051 .endm
6052@end example
6258339f 6053@end table
5e75c3ab 6054
96e9638b 6055Note: this problem of correctly identifying string parameters to pseudo ops
01642c12 6056also applies to the identifiers used in @code{.irp} (@pxref{Irp})
96e9638b 6057and @code{.irpc} (@pxref{Irpc}) as well.
5e75c3ab 6058
252b5132
RH
6059@item .endm
6060@cindex @code{endm} directive
6061Mark the end of a macro definition.
6062
6063@item .exitm
6064@cindex @code{exitm} directive
6065Exit early from the current macro definition.
6066
6067@cindex number of macros executed
6068@cindex macros, count executed
6069@item \@@
a4fb0134 6070@command{@value{AS}} maintains a counter of how many macros it has
252b5132
RH
6071executed in this pseudo-variable; you can copy that number to your
6072output with @samp{\@@}, but @emph{only within a macro definition}.
6073
252b5132
RH
6074@item LOCAL @var{name} [ , @dots{} ]
6075@emph{Warning: @code{LOCAL} is only available if you select ``alternate
caa32fe5
NC
6076macro syntax'' with @samp{--alternate} or @code{.altmacro}.}
6077@xref{Altmacro,,@code{.altmacro}}.
6078@end ftable
252b5132 6079
ccf8a69b
BW
6080@node MRI
6081@section @code{.mri @var{val}}
caa32fe5 6082
ccf8a69b
BW
6083@cindex @code{mri} directive
6084@cindex MRI mode, temporarily
6085If @var{val} is non-zero, this tells @command{@value{AS}} to enter MRI mode. If
6086@var{val} is zero, this tells @command{@value{AS}} to exit MRI mode. This change
6087affects code assembled until the next @code{.mri} directive, or until the end
6088of the file. @xref{M, MRI mode, MRI mode}.
252b5132 6089
caa32fe5
NC
6090@node Noaltmacro
6091@section @code{.noaltmacro}
96e9638b 6092Disable alternate macro mode. @xref{Altmacro}.
caa32fe5 6093
252b5132
RH
6094@node Nolist
6095@section @code{.nolist}
6096
6097@cindex @code{nolist} directive
6098@cindex listing control, turning off
6099Control (in conjunction with the @code{.list} directive) whether or
6100not assembly listings are generated. These two directives maintain an
6101internal counter (which is zero initially). @code{.list} increments the
6102counter, and @code{.nolist} decrements it. Assembly listings are
6103generated whenever the counter is greater than zero.
6104
62a02d25
L
6105@node Nop
6106@section @code{.nop @var{size}[, @var{control}]}
6107
6108@cindex @code{nop} directive
6109@cindex filling memory with no-op instructions
6110This directive emits @var{size} bytes filled with no-op instructions.
6111@var{size} is absolute expression, which must be a positve value.
6112@var{control} controls how no-op instructions should be generated. If
6113the comma and @var{control} are omitted, @var{control} is assumed to be
6114zero.
6115
6116Note: For Intel 80386 and AMD x86-64 targets, @var{control} specifies
6117the size limit of a no-op instruction. The valid values of @var{control}
6118are between 0 and 8 for 16-bit mode, between 0 and 10 for 32-bit mode,
6119between 0 and 11 for 64-bit mode. When 0 is used, the no-op instruction
6120size limit is set to the maximum supported size.
6121
252b5132
RH
6122@node Octa
6123@section @code{.octa @var{bignums}}
6124
6125@c FIXME: double size emitted for "octa" on i960, others? Or warn?
6126@cindex @code{octa} directive
6127@cindex integer, 16-byte
6128@cindex sixteen byte integer
6129This directive expects zero or more bignums, separated by commas. For each
6130bignum, it emits a 16-byte integer.
6131
6132The term ``octa'' comes from contexts in which a ``word'' is two bytes;
6133hence @emph{octa}-word for 16 bytes.
6134
9aec2026
NC
6135@node Offset
6136@section @code{.offset @var{loc}}
6137
6138@cindex @code{offset} directive
6139Set the location counter to @var{loc} in the absolute section. @var{loc} must
6140be an absolute expression. This directive may be useful for defining
6141symbols with absolute values. Do not confuse it with the @code{.org}
fa94de6b 6142directive.
9aec2026 6143
252b5132
RH
6144@node Org
6145@section @code{.org @var{new-lc} , @var{fill}}
6146
6147@cindex @code{org} directive
6148@cindex location counter, advancing
6149@cindex advancing location counter
6150@cindex current address, advancing
6151Advance the location counter of the current section to
6152@var{new-lc}. @var{new-lc} is either an absolute expression or an
6153expression with the same section as the current subsection. That is,
6154you can't use @code{.org} to cross sections: if @var{new-lc} has the
6155wrong section, the @code{.org} directive is ignored. To be compatible
6156with former assemblers, if the section of @var{new-lc} is absolute,
a4fb0134 6157@command{@value{AS}} issues a warning, then pretends the section of @var{new-lc}
252b5132
RH
6158is the same as the current subsection.
6159
6160@code{.org} may only increase the location counter, or leave it
6161unchanged; you cannot use @code{.org} to move the location counter
6162backwards.
6163
6164@c double negative used below "not undefined" because this is a specific
6165@c reference to "undefined" (as SEG_UNKNOWN is called in this manual)
6166@c section. doc@cygnus.com 18feb91
a4fb0134 6167Because @command{@value{AS}} tries to assemble programs in one pass, @var{new-lc}
252b5132
RH
6168may not be undefined. If you really detest this restriction we eagerly await
6169a chance to share your improved assembler.
6170
6171Beware that the origin is relative to the start of the section, not
6172to the start of the subsection. This is compatible with other
6173people's assemblers.
6174
6175When the location counter (of the current subsection) is advanced, the
6176intervening bytes are filled with @var{fill} which should be an
6177absolute expression. If the comma and @var{fill} are omitted,
6178@var{fill} defaults to zero.
6179
6180@node P2align
6181@section @code{.p2align[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}}
6182
6183@cindex padding the location counter given a power of two
6184@cindex @code{p2align} directive
6185Pad the location counter (in the current subsection) to a particular
6186storage boundary. The first expression (which must be absolute) is the
6187number of low-order zero bits the location counter must have after
6188advancement. For example @samp{.p2align 3} advances the location
6189counter until it a multiple of 8. If the location counter is already a
6190multiple of 8, no change is needed.
6191
6192The second expression (also absolute) gives the fill value to be stored in the
6193padding bytes. It (and the comma) may be omitted. If it is omitted, the
2ca23e65 6194padding bytes are normally zero. However, on most systems, if the section is
252b5132
RH
6195marked as containing code and the fill value is omitted, the space is filled
6196with no-op instructions.
6197
6198The third expression is also absolute, and is also optional. If it is present,
6199it is the maximum number of bytes that should be skipped by this alignment
6200directive. If doing the alignment would require skipping more bytes than the
6201specified maximum, then the alignment is not done at all. You can omit the
6202fill value (the second argument) entirely by simply using two commas after the
6203required alignment; this can be useful if you want the alignment to be filled
6204with no-op instructions when appropriate.
6205
6206@cindex @code{p2alignw} directive
6207@cindex @code{p2alignl} directive
6208The @code{.p2alignw} and @code{.p2alignl} directives are variants of the
6209@code{.p2align} directive. The @code{.p2alignw} directive treats the fill
6210pattern as a two byte word value. The @code{.p2alignl} directives treats the
6211fill pattern as a four byte longword value. For example, @code{.p2alignw
62122,0x368d} will align to a multiple of 4. If it skips two bytes, they will be
6213filled in with the value 0x368d (the exact placement of the bytes depends upon
6214the endianness of the processor). If it skips 1 or 3 bytes, the fill value is
6215undefined.
6216
ccf8a69b
BW
6217@ifset ELF
6218@node PopSection
6219@section @code{.popsection}
6220
6221@cindex @code{popsection} directive
6222@cindex Section Stack
6223This is one of the ELF section stack manipulation directives. The others are
01642c12
RM
6224@code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}),
6225@code{.pushsection} (@pxref{PushSection}), and @code{.previous}
ccf8a69b
BW
6226(@pxref{Previous}).
6227
6228This directive replaces the current section (and subsection) with the top
6229section (and subsection) on the section stack. This section is popped off the
01642c12 6230stack.
ccf8a69b
BW
6231@end ifset
6232
c91d2e08
NC
6233@ifset ELF
6234@node Previous
6235@section @code{.previous}
6236
c1253627 6237@cindex @code{previous} directive
c91d2e08
NC
6238@cindex Section Stack
6239This is one of the ELF section stack manipulation directives. The others are
a349d9dd
PB
6240@code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}),
6241@code{.pushsection} (@pxref{PushSection}), and @code{.popsection}
6242(@pxref{PopSection}).
c91d2e08
NC
6243
6244This directive swaps the current section (and subsection) with most recently
8b040e0a 6245referenced section/subsection pair prior to this one. Multiple
c91d2e08 6246@code{.previous} directives in a row will flip between two sections (and their
8b040e0a
NC
6247subsections). For example:
6248
6249@smallexample
6250.section A
6251 .subsection 1
6252 .word 0x1234
6253 .subsection 2
6254 .word 0x5678
6255.previous
6256 .word 0x9abc
6257@end smallexample
6258
6259Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of
6260section A. Whilst:
6261
6262@smallexample
6263.section A
6264.subsection 1
6265 # Now in section A subsection 1
6266 .word 0x1234
6267.section B
6268.subsection 0
6269 # Now in section B subsection 0
6270 .word 0x5678
6271.subsection 1
6272 # Now in section B subsection 1
6273 .word 0x9abc
6274.previous
6275 # Now in section B subsection 0
6276 .word 0xdef0
6277@end smallexample
6278
6279Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of
6280section B and 0x9abc into subsection 1 of section B.
c91d2e08
NC
6281
6282In terms of the section stack, this directive swaps the current section with
6283the top section on the section stack.
6284@end ifset
6285
252b5132
RH
6286@node Print
6287@section @code{.print @var{string}}
6288
6289@cindex @code{print} directive
a4fb0134 6290@command{@value{AS}} will print @var{string} on the standard output during
252b5132
RH
6291assembly. You must put @var{string} in double quotes.
6292
c91d2e08
NC
6293@ifset ELF
6294@node Protected
6295@section @code{.protected @var{names}}
6296
c1253627
NC
6297@cindex @code{protected} directive
6298@cindex visibility
ed9589d4 6299This is one of the ELF visibility directives. The other two are
a349d9dd 6300@code{.hidden} (@pxref{Hidden}) and @code{.internal} (@pxref{Internal}).
c91d2e08
NC
6301
6302This directive overrides the named symbols default visibility (which is set by
6303their binding: local, global or weak). The directive sets the visibility to
6304@code{protected} which means that any references to the symbols from within the
6305components that defines them must be resolved to the definition in that
6306component, even if a definition in another component would normally preempt
01642c12 6307this.
c91d2e08
NC
6308@end ifset
6309
252b5132
RH
6310@node Psize
6311@section @code{.psize @var{lines} , @var{columns}}
6312
6313@cindex @code{psize} directive
6314@cindex listing control: paper size
6315@cindex paper size, for listings
6316Use this directive to declare the number of lines---and, optionally, the
6317number of columns---to use for each page, when generating listings.
6318
6319If you do not use @code{.psize}, listings use a default line-count
6320of 60. You may omit the comma and @var{columns} specification; the
6321default width is 200 columns.
6322
a4fb0134 6323@command{@value{AS}} generates formfeeds whenever the specified number of
252b5132
RH
6324lines is exceeded (or whenever you explicitly request one, using
6325@code{.eject}).
6326
6327If you specify @var{lines} as @code{0}, no formfeeds are generated save
6328those explicitly specified with @code{.eject}.
6329
6330@node Purgem
6331@section @code{.purgem @var{name}}
6332
6333@cindex @code{purgem} directive
6334Undefine the macro @var{name}, so that later uses of the string will not be
6335expanded. @xref{Macro}.
6336
c91d2e08
NC
6337@ifset ELF
6338@node PushSection
9cfc3331 6339@section @code{.pushsection @var{name} [, @var{subsection}] [, "@var{flags}"[, @@@var{type}[,@var{arguments}]]]}
c91d2e08 6340
c1253627 6341@cindex @code{pushsection} directive
c91d2e08
NC
6342@cindex Section Stack
6343This is one of the ELF section stack manipulation directives. The others are
01642c12
RM
6344@code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}),
6345@code{.popsection} (@pxref{PopSection}), and @code{.previous}
a349d9dd 6346(@pxref{Previous}).
c91d2e08 6347
e9863d7f
DJ
6348This directive pushes the current section (and subsection) onto the
6349top of the section stack, and then replaces the current section and
9cfc3331
L
6350subsection with @code{name} and @code{subsection}. The optional
6351@code{flags}, @code{type} and @code{arguments} are treated the same
6352as in the @code{.section} (@pxref{Section}) directive.
c91d2e08
NC
6353@end ifset
6354
252b5132
RH
6355@node Quad
6356@section @code{.quad @var{bignums}}
6357
6358@cindex @code{quad} directive
6359@code{.quad} expects zero or more bignums, separated by commas. For
6360each bignum, it emits
6361@ifclear bignum-16
6362an 8-byte integer. If the bignum won't fit in 8 bytes, it prints a
6363warning message; and just takes the lowest order 8 bytes of the bignum.
6364@cindex eight-byte integer
6365@cindex integer, 8-byte
6366
6367The term ``quad'' comes from contexts in which a ``word'' is two bytes;
6368hence @emph{quad}-word for 8 bytes.
6369@end ifclear
6370@ifset bignum-16
6371a 16-byte integer. If the bignum won't fit in 16 bytes, it prints a
6372warning message; and just takes the lowest order 16 bytes of the bignum.
6373@cindex sixteen-byte integer
6374@cindex integer, 16-byte
6375@end ifset
6376
05e9452c
AM
6377@node Reloc
6378@section @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]}
6379
6380@cindex @code{reloc} directive
6381Generate a relocation at @var{offset} of type @var{reloc_name} with value
6382@var{expression}. If @var{offset} is a number, the relocation is generated in
6383the current section. If @var{offset} is an expression that resolves to a
6384symbol plus offset, the relocation is generated in the given symbol's section.
6385@var{expression}, if present, must resolve to a symbol plus addend or to an
6386absolute value, but note that not all targets support an addend. e.g. ELF REL
6387targets such as i386 store an addend in the section contents rather than in the
6388relocation. This low level interface does not support addends stored in the
6389section.
6390
252b5132
RH
6391@node Rept
6392@section @code{.rept @var{count}}
6393
6394@cindex @code{rept} directive
6395Repeat the sequence of lines between the @code{.rept} directive and the next
6396@code{.endr} directive @var{count} times.
6397
6398For example, assembling
6399
6400@example
6401 .rept 3
6402 .long 0
6403 .endr
6404@end example
6405
6406is equivalent to assembling
6407
6408@example
6409 .long 0
6410 .long 0
6411 .long 0
6412@end example
6413
808811a3
NC
6414A count of zero is allowed, but nothing is generated. Negative counts are not
6415allowed and if encountered will be treated as if they were zero.
6416
252b5132
RH
6417@node Sbttl
6418@section @code{.sbttl "@var{subheading}"}
6419
6420@cindex @code{sbttl} directive
6421@cindex subtitles for listings
6422@cindex listing control: subtitle
6423Use @var{subheading} as the title (third line, immediately after the
6424title line) when generating assembly listings.
6425
6426This directive affects subsequent pages, as well as the current page if
6427it appears within ten lines of the top of a page.
6428
6429@ifset COFF
6430@node Scl
6431@section @code{.scl @var{class}}
6432
6433@cindex @code{scl} directive
6434@cindex symbol storage class (COFF)
6435@cindex COFF symbol storage class
6436Set the storage-class value for a symbol. This directive may only be
6437used inside a @code{.def}/@code{.endef} pair. Storage class may flag
6438whether a symbol is static or external, or it may record further
6439symbolic debugging information.
6440@ifset BOUT
6441
6442The @samp{.scl} directive is primarily associated with COFF output; when
a4fb0134 6443configured to generate @code{b.out} output format, @command{@value{AS}}
252b5132
RH
6444accepts this directive but ignores it.
6445@end ifset
6446@end ifset
6447
c1253627 6448@ifset COFF-ELF
252b5132 6449@node Section
c1253627 6450@section @code{.section @var{name}}
252b5132 6451
252b5132
RH
6452@cindex named section
6453Use the @code{.section} directive to assemble the following code into a section
6454named @var{name}.
6455
6456This directive is only supported for targets that actually support arbitrarily
6457named sections; on @code{a.out} targets, for example, it is not accepted, even
6458with a standard @code{a.out} section name.
6459
c1253627
NC
6460@ifset COFF
6461@ifset ELF
6462@c only print the extra heading if both COFF and ELF are set
6463@subheading COFF Version
6464@end ifset
6465
6466@cindex @code{section} directive (COFF version)
252b5132
RH
6467For COFF targets, the @code{.section} directive is used in one of the following
6468ways:
c91d2e08 6469
252b5132
RH
6470@smallexample
6471.section @var{name}[, "@var{flags}"]
4e188d17 6472.section @var{name}[, @var{subsection}]
252b5132
RH
6473@end smallexample
6474
6475If the optional argument is quoted, it is taken as flags to use for the
6476section. Each flag is a single character. The following flags are recognized:
eda683bb 6477
252b5132
RH
6478@table @code
6479@item b
6480bss section (uninitialized data)
6481@item n
6482section is not loaded
6483@item w
6484writable section
6485@item d
6486data section
70e0ee1a
KT
6487@item e
6488exclude section from linking
252b5132
RH
6489@item r
6490read-only section
6491@item x
6492executable section
2dcc60be
ILT
6493@item s
6494shared section (meaningful for PE targets)
6ff96af6
NC
6495@item a
6496ignored. (For compatibility with the ELF version)
63ad59ae
KT
6497@item y
6498section is not readable (meaningful for PE targets)
31907d5e
DK
6499@item 0-9
6500single-digit power-of-two section alignment (GNU extension)
252b5132
RH
6501@end table
6502
6503If no flags are specified, the default flags depend upon the section name. If
6504the section name is not recognized, the default will be for the section to be
7e84d676
NC
6505loaded and writable. Note the @code{n} and @code{w} flags remove attributes
6506from the section, rather than adding them, so if they are used on their own it
6507will be as if no flags had been specified at all.
252b5132
RH
6508
6509If the optional argument to the @code{.section} directive is not quoted, it is
4e188d17 6510taken as a subsection number (@pxref{Sub-Sections}).
c1253627 6511@end ifset
252b5132
RH
6512
6513@ifset ELF
c1253627
NC
6514@ifset COFF
6515@c only print the extra heading if both COFF and ELF are set
6516@subheading ELF Version
6517@end ifset
6518
c91d2e08
NC
6519@cindex Section Stack
6520This is one of the ELF section stack manipulation directives. The others are
01642c12 6521@code{.subsection} (@pxref{SubSection}), @code{.pushsection}
a349d9dd
PB
6522(@pxref{PushSection}), @code{.popsection} (@pxref{PopSection}), and
6523@code{.previous} (@pxref{Previous}).
c91d2e08 6524
c1253627 6525@cindex @code{section} directive (ELF version)
252b5132 6526For ELF targets, the @code{.section} directive is used like this:
c91d2e08 6527
252b5132 6528@smallexample
7047dd1e 6529.section @var{name} [, "@var{flags}"[, @@@var{type}[,@var{flag_specific_arguments}]]]
252b5132 6530@end smallexample
c91d2e08 6531
451133ce
NP
6532@anchor{Section Name Substitutions}
6533@kindex --sectname-subst
6534@cindex section name substitution
6535If the @samp{--sectname-subst} command-line option is provided, the @var{name}
6536argument may contain a substitution sequence. Only @code{%S} is supported
6537at the moment, and substitutes the current section name. For example:
6538
6539@smallexample
6540.macro exception_code
6541.section %S.exception
6542[exception code here]
6543.previous
6544.endm
6545
6546.text
6547[code]
6548exception_code
6549[...]
6550
6551.section .init
6552[init code]
6553exception_code
6554[...]
6555@end smallexample
6556
6557The two @code{exception_code} invocations above would create the
6558@code{.text.exception} and @code{.init.exception} sections respectively.
33eaf5de
NC
6559This is useful e.g. to discriminate between ancillary sections that are
6560tied to setup code to be discarded after use from ancillary sections that
451133ce
NP
6561need to stay resident without having to define multiple @code{exception_code}
6562macros just for that purpose.
6563
252b5132 6564The optional @var{flags} argument is a quoted string which may contain any
a349d9dd 6565combination of the following characters:
eda683bb 6566
252b5132
RH
6567@table @code
6568@item a
6569section is allocatable
a91e1603
L
6570@item d
6571section is a GNU_MBIND section
18ae9cc1
L
6572@item e
6573section is excluded from executable and shared library.
252b5132
RH
6574@item w
6575section is writable
6576@item x
6577section is executable
ec38dd05
JJ
6578@item M
6579section is mergeable
6580@item S
6581section contains zero terminated strings
22fe14ad
NC
6582@item G
6583section is a member of a section group
6584@item T
6585section is used for thread-local-storage
01642c12
RM
6586@item ?
6587section is a member of the previously-current section's group, if any
eda683bb 6588@item @code{<number>}
9fb71ee4
NC
6589a numeric value indicating the bits to be set in the ELF section header's flags
6590field. Note - if one or more of the alphabetic characters described above is
6591also included in the flags field, their bit values will be ORed into the
6592resulting value.
eda683bb
NC
6593@item @code{<target specific>}
6594some targets extend this list with their own flag characters
252b5132
RH
6595@end table
6596
9fb71ee4
NC
6597Note - once a section's flags have been set they cannot be changed. There are
6598a few exceptions to this rule however. Processor and application specific
6599flags can be added to an already defined section. The @code{.interp},
6600@code{.strtab} and @code{.symtab} sections can have the allocate flag
6601(@code{a}) set after they are initially defined, and the @code{.note-GNU-stack}
eda683bb 6602section may have the executable (@code{x}) flag added.
9fb71ee4 6603
252b5132 6604The optional @var{type} argument may contain one of the following constants:
eda683bb 6605
252b5132
RH
6606@table @code
6607@item @@progbits
6608section contains data
6609@item @@nobits
6610section does not contain data (i.e., section only occupies space)
22fe14ad
NC
6611@item @@note
6612section contains data which is used by things other than the program
10b016c2
PB
6613@item @@init_array
6614section contains an array of pointers to init functions
6615@item @@fini_array
6616section contains an array of pointers to finish functions
6617@item @@preinit_array
6618section contains an array of pointers to pre-init functions
eda683bb 6619@item @@@code{<number>}
9fb71ee4 6620a numeric value to be set as the ELF section header's type field.
eda683bb 6621@item @@@code{<target specific>}
9fb71ee4 6622some targets extend this list with their own types
252b5132
RH
6623@end table
6624
9fb71ee4
NC
6625Many targets only support the first three section types. The type may be
6626enclosed in double quotes if necessary.
10b016c2 6627
ececec60
NC
6628Note on targets where the @code{@@} character is the start of a comment (eg
6629ARM) then another character is used instead. For example the ARM port uses the
6630@code{%} character.
6631
9fb71ee4
NC
6632Note - some sections, eg @code{.text} and @code{.data} are considered to be
6633special and have fixed types. Any attempt to declare them with a different
6634type will generate an error from the assembler.
6635
22fe14ad 6636If @var{flags} contains the @code{M} symbol then the @var{type} argument must
96e9638b 6637be specified as well as an extra argument---@var{entsize}---like this:
22fe14ad
NC
6638
6639@smallexample
6640.section @var{name} , "@var{flags}"M, @@@var{type}, @var{entsize}
6641@end smallexample
6642
6643Sections with the @code{M} flag but not @code{S} flag must contain fixed size
6644constants, each @var{entsize} octets long. Sections with both @code{M} and
6645@code{S} must contain zero terminated strings where each character is
6646@var{entsize} bytes long. The linker may remove duplicates within sections with
6647the same name, same entity size and same flags. @var{entsize} must be an
90dce00a
AM
6648absolute expression. For sections with both @code{M} and @code{S}, a string
6649which is a suffix of a larger string is considered a duplicate. Thus
6650@code{"def"} will be merged with @code{"abcdef"}; A reference to the first
6651@code{"def"} will be changed to a reference to @code{"abcdef"+3}.
22fe14ad
NC
6652
6653If @var{flags} contains the @code{G} symbol then the @var{type} argument must
6654be present along with an additional field like this:
6655
6656@smallexample
6657.section @var{name} , "@var{flags}"G, @@@var{type}, @var{GroupName}[, @var{linkage}]
6658@end smallexample
6659
6660The @var{GroupName} field specifies the name of the section group to which this
6661particular section belongs. The optional linkage field can contain:
eda683bb 6662
22fe14ad
NC
6663@table @code
6664@item comdat
6665indicates that only one copy of this section should be retained
6666@item .gnu.linkonce
6667an alias for comdat
6668@end table
6669
96e9638b 6670Note: if both the @var{M} and @var{G} flags are present then the fields for
22fe14ad
NC
6671the Merge flag should come first, like this:
6672
6673@smallexample
6674.section @var{name} , "@var{flags}"MG, @@@var{type}, @var{entsize}, @var{GroupName}[, @var{linkage}]
6675@end smallexample
ec38dd05 6676
01642c12
RM
6677If @var{flags} contains the @code{?} symbol then it may not also contain the
6678@code{G} symbol and the @var{GroupName} or @var{linkage} fields should not be
6679present. Instead, @code{?} says to consider the section that's current before
6680this directive. If that section used @code{G}, then the new section will use
6681@code{G} with those same @var{GroupName} and @var{linkage} fields implicitly.
6682If not, then the @code{?} symbol has no effect.
6683
252b5132
RH
6684If no flags are specified, the default flags depend upon the section name. If
6685the section name is not recognized, the default will be for the section to have
6686none of the above flags: it will not be allocated in memory, nor writable, nor
6687executable. The section will contain data.
6688
6689For ELF targets, the assembler supports another type of @code{.section}
6690directive for compatibility with the Solaris assembler:
c91d2e08 6691
252b5132
RH
6692@smallexample
6693.section "@var{name}"[, @var{flags}...]
6694@end smallexample
c91d2e08 6695
252b5132
RH
6696Note that the section name is quoted. There may be a sequence of comma
6697separated flags:
eda683bb 6698
252b5132
RH
6699@table @code
6700@item #alloc
6701section is allocatable
6702@item #write
6703section is writable
6704@item #execinstr
6705section is executable
18ae9cc1
L
6706@item #exclude
6707section is excluded from executable and shared library.
22fe14ad
NC
6708@item #tls
6709section is used for thread local storage
252b5132 6710@end table
c91d2e08 6711
e9863d7f
DJ
6712This directive replaces the current section and subsection. See the
6713contents of the gas testsuite directory @code{gas/testsuite/gas/elf} for
6714some examples of how this directive and the other section stack directives
6715work.
c1253627
NC
6716@end ifset
6717@end ifset
252b5132
RH
6718
6719@node Set
6720@section @code{.set @var{symbol}, @var{expression}}
6721
6722@cindex @code{set} directive
6723@cindex symbol value, setting
6724Set the value of @var{symbol} to @var{expression}. This
6725changes @var{symbol}'s value and type to conform to
6726@var{expression}. If @var{symbol} was flagged as external, it remains
6727flagged (@pxref{Symbol Attributes}).
6728
5d239759
NC
6729You may @code{.set} a symbol many times in the same assembly provided that the
6730values given to the symbol are constants. Values that are based on expressions
6731involving other symbols are allowed, but some targets may restrict this to only
6732being done once per assembly. This is because those targets do not set the
6733addresses of symbols at assembly time, but rather delay the assignment until a
6734final link is performed. This allows the linker a chance to change the code in
6735the files, changing the location of, and the relative distance between, various
6736different symbols.
252b5132
RH
6737
6738If you @code{.set} a global symbol, the value stored in the object
6739file is the last value stored into it.
6740
3c9b82ba
NC
6741@ifset Z80
6742On Z80 @code{set} is a real instruction, use
6743@samp{@var{symbol} defl @var{expression}} instead.
6744@end ifset
6745
252b5132
RH
6746@node Short
6747@section @code{.short @var{expressions}}
6748
6749@cindex @code{short} directive
6750@ifset GENERIC
6751@code{.short} is normally the same as @samp{.word}.
6752@xref{Word,,@code{.word}}.
6753
6754In some configurations, however, @code{.short} and @code{.word} generate
96e9638b 6755numbers of different lengths. @xref{Machine Dependencies}.
252b5132
RH
6756@end ifset
6757@ifclear GENERIC
6758@ifset W16
6759@code{.short} is the same as @samp{.word}. @xref{Word,,@code{.word}}.
6760@end ifset
6761@ifset W32
6762This expects zero or more @var{expressions}, and emits
6763a 16 bit number for each.
6764@end ifset
6765@end ifclear
6766
6767@node Single
6768@section @code{.single @var{flonums}}
6769
6770@cindex @code{single} directive
6771@cindex floating point numbers (single)
6772This directive assembles zero or more flonums, separated by commas. It
6773has the same effect as @code{.float}.
6774@ifset GENERIC
6775The exact kind of floating point numbers emitted depends on how
a4fb0134 6776@command{@value{AS}} is configured. @xref{Machine Dependencies}.
252b5132
RH
6777@end ifset
6778@ifclear GENERIC
6779@ifset IEEEFLOAT
6780On the @value{TARGET} family, @code{.single} emits 32-bit floating point
6781numbers in @sc{ieee} format.
6782@end ifset
6783@end ifclear
6784
c1253627 6785@ifset COFF-ELF
252b5132 6786@node Size
c1253627 6787@section @code{.size}
c91d2e08 6788
c1253627
NC
6789This directive is used to set the size associated with a symbol.
6790
6791@ifset COFF
6792@ifset ELF
6793@c only print the extra heading if both COFF and ELF are set
6794@subheading COFF Version
6795@end ifset
6796
6797@cindex @code{size} directive (COFF version)
6798For COFF targets, the @code{.size} directive is only permitted inside
6799@code{.def}/@code{.endef} pairs. It is used like this:
6800
6801@smallexample
6802.size @var{expression}
6803@end smallexample
252b5132 6804
c91d2e08 6805@ifset BOUT
252b5132 6806@samp{.size} is only meaningful when generating COFF format output; when
a4fb0134 6807@command{@value{AS}} is generating @code{b.out}, it accepts this directive but
252b5132
RH
6808ignores it.
6809@end ifset
c1253627 6810@end ifset
c91d2e08 6811
c1253627
NC
6812@ifset ELF
6813@ifset COFF
6814@c only print the extra heading if both COFF and ELF are set
6815@subheading ELF Version
6816@end ifset
6817
6818@cindex @code{size} directive (ELF version)
6819For ELF targets, the @code{.size} directive is used like this:
c91d2e08 6820
c1253627
NC
6821@smallexample
6822.size @var{name} , @var{expression}
6823@end smallexample
6824
6825This directive sets the size associated with a symbol @var{name}.
c91d2e08
NC
6826The size in bytes is computed from @var{expression} which can make use of label
6827arithmetic. This directive is typically used to set the size of function
6828symbols.
c1253627
NC
6829@end ifset
6830@end ifset
252b5132 6831
252b5132
RH
6832@ifclear no-space-dir
6833@node Skip
6834@section @code{.skip @var{size} , @var{fill}}
6835
6836@cindex @code{skip} directive
6837@cindex filling memory
6838This directive emits @var{size} bytes, each of value @var{fill}. Both
6839@var{size} and @var{fill} are absolute expressions. If the comma and
6840@var{fill} are omitted, @var{fill} is assumed to be zero. This is the same as
6841@samp{.space}.
884f0d36 6842@end ifclear
252b5132 6843
ccf8a69b
BW
6844@node Sleb128
6845@section @code{.sleb128 @var{expressions}}
6846
6847@cindex @code{sleb128} directive
01642c12 6848@var{sleb128} stands for ``signed little endian base 128.'' This is a
ccf8a69b
BW
6849compact, variable length representation of numbers used by the DWARF
6850symbolic debugging format. @xref{Uleb128, ,@code{.uleb128}}.
6851
884f0d36 6852@ifclear no-space-dir
252b5132
RH
6853@node Space
6854@section @code{.space @var{size} , @var{fill}}
6855
6856@cindex @code{space} directive
6857@cindex filling memory
6858This directive emits @var{size} bytes, each of value @var{fill}. Both
6859@var{size} and @var{fill} are absolute expressions. If the comma
6860and @var{fill} are omitted, @var{fill} is assumed to be zero. This is the same
6861as @samp{.skip}.
6862
6863@ifset HPPA
6864@quotation
6865@emph{Warning:} @code{.space} has a completely different meaning for HPPA
6866targets; use @code{.block} as a substitute. See @cite{HP9000 Series 800
6867Assembly Language Reference Manual} (HP 92432-90001) for the meaning of the
6868@code{.space} directive. @xref{HPPA Directives,,HPPA Assembler Directives},
6869for a summary.
6870@end quotation
6871@end ifset
6872@end ifclear
6873
252b5132
RH
6874@ifset have-stabs
6875@node Stab
6876@section @code{.stabd, .stabn, .stabs}
6877
6878@cindex symbolic debuggers, information for
6879@cindex @code{stab@var{x}} directives
6880There are three directives that begin @samp{.stab}.
6881All emit symbols (@pxref{Symbols}), for use by symbolic debuggers.
a4fb0134 6882The symbols are not entered in the @command{@value{AS}} hash table: they
252b5132
RH
6883cannot be referenced elsewhere in the source file.
6884Up to five fields are required:
6885
6886@table @var
6887@item string
6888This is the symbol's name. It may contain any character except
6889@samp{\000}, so is more general than ordinary symbol names. Some
6890debuggers used to code arbitrarily complex structures into symbol names
6891using this field.
6892
6893@item type
6894An absolute expression. The symbol's type is set to the low 8 bits of
6895this expression. Any bit pattern is permitted, but @code{@value{LD}}
6896and debuggers choke on silly bit patterns.
6897
6898@item other
6899An absolute expression. The symbol's ``other'' attribute is set to the
6900low 8 bits of this expression.
6901
6902@item desc
6903An absolute expression. The symbol's descriptor is set to the low 16
6904bits of this expression.
6905
6906@item value
6907An absolute expression which becomes the symbol's value.
6908@end table
6909
6910If a warning is detected while reading a @code{.stabd}, @code{.stabn},
6911or @code{.stabs} statement, the symbol has probably already been created;
6912you get a half-formed symbol in your object file. This is
6913compatible with earlier assemblers!
6914
6915@table @code
6916@cindex @code{stabd} directive
6917@item .stabd @var{type} , @var{other} , @var{desc}
6918
6919The ``name'' of the symbol generated is not even an empty string.
6920It is a null pointer, for compatibility. Older assemblers used a
6921null pointer so they didn't waste space in object files with empty
6922strings.
6923
6924The symbol's value is set to the location counter,
6925relocatably. When your program is linked, the value of this symbol
6926is the address of the location counter when the @code{.stabd} was
6927assembled.
6928
6929@cindex @code{stabn} directive
6930@item .stabn @var{type} , @var{other} , @var{desc} , @var{value}
6931The name of the symbol is set to the empty string @code{""}.
6932
6933@cindex @code{stabs} directive
6934@item .stabs @var{string} , @var{type} , @var{other} , @var{desc} , @var{value}
6935All five fields are specified.
6936@end table
6937@end ifset
6938@c end have-stabs
6939
6940@node String
38a57ae7 6941@section @code{.string} "@var{str}", @code{.string8} "@var{str}", @code{.string16}
01642c12 6942"@var{str}", @code{.string32} "@var{str}", @code{.string64} "@var{str}"
252b5132
RH
6943
6944@cindex string, copying to object file
38a57ae7
NC
6945@cindex string8, copying to object file
6946@cindex string16, copying to object file
6947@cindex string32, copying to object file
6948@cindex string64, copying to object file
252b5132 6949@cindex @code{string} directive
38a57ae7
NC
6950@cindex @code{string8} directive
6951@cindex @code{string16} directive
6952@cindex @code{string32} directive
6953@cindex @code{string64} directive
252b5132
RH
6954
6955Copy the characters in @var{str} to the object file. You may specify more than
6956one string to copy, separated by commas. Unless otherwise specified for a
6957particular machine, the assembler marks the end of each string with a 0 byte.
6958You can use any of the escape sequences described in @ref{Strings,,Strings}.
6959
01642c12 6960The variants @code{string16}, @code{string32} and @code{string64} differ from
38a57ae7
NC
6961the @code{string} pseudo opcode in that each 8-bit character from @var{str} is
6962copied and expanded to 16, 32 or 64 bits respectively. The expanded characters
6963are stored in target endianness byte order.
6964
6965Example:
6966@smallexample
6967 .string32 "BYE"
6968expands to:
6969 .string "B\0\0\0Y\0\0\0E\0\0\0" /* On little endian targets. */
6970 .string "\0\0\0B\0\0\0Y\0\0\0E" /* On big endian targets. */
6971@end smallexample
6972
6973
252b5132
RH
6974@node Struct
6975@section @code{.struct @var{expression}}
6976
6977@cindex @code{struct} directive
6978Switch to the absolute section, and set the section offset to @var{expression},
6979which must be an absolute expression. You might use this as follows:
6980@smallexample
6981 .struct 0
6982field1:
6983 .struct field1 + 4
6984field2:
6985 .struct field2 + 4
6986field3:
6987@end smallexample
6988This would define the symbol @code{field1} to have the value 0, the symbol
6989@code{field2} to have the value 4, and the symbol @code{field3} to have the
6990value 8. Assembly would be left in the absolute section, and you would need to
6991use a @code{.section} directive of some sort to change to some other section
6992before further assembly.
6993
c91d2e08
NC
6994@ifset ELF
6995@node SubSection
6996@section @code{.subsection @var{name}}
6997
c1253627 6998@cindex @code{subsection} directive
c91d2e08
NC
6999@cindex Section Stack
7000This is one of the ELF section stack manipulation directives. The others are
01642c12
RM
7001@code{.section} (@pxref{Section}), @code{.pushsection} (@pxref{PushSection}),
7002@code{.popsection} (@pxref{PopSection}), and @code{.previous}
a349d9dd 7003(@pxref{Previous}).
c91d2e08
NC
7004
7005This directive replaces the current subsection with @code{name}. The current
7006section is not changed. The replaced subsection is put onto the section stack
7007in place of the then current top of stack subsection.
c91d2e08
NC
7008@end ifset
7009
252b5132
RH
7010@ifset ELF
7011@node Symver
7012@section @code{.symver}
7013@cindex @code{symver} directive
7014@cindex symbol versioning
7015@cindex versions of symbols
7016Use the @code{.symver} directive to bind symbols to specific version nodes
7017within a source file. This is only supported on ELF platforms, and is
7018typically used when assembling files to be linked into a shared library.
7019There are cases where it may make sense to use this in objects to be bound
7020into an application itself so as to override a versioned symbol from a
7021shared library.
7022
79082ff0 7023For ELF targets, the @code{.symver} directive can be used like this:
252b5132
RH
7024@smallexample
7025.symver @var{name}, @var{name2@@nodename}
7026@end smallexample
339681c0 7027If the symbol @var{name} is defined within the file
79082ff0 7028being assembled, the @code{.symver} directive effectively creates a symbol
252b5132
RH
7029alias with the name @var{name2@@nodename}, and in fact the main reason that we
7030just don't try and create a regular alias is that the @var{@@} character isn't
7031permitted in symbol names. The @var{name2} part of the name is the actual name
7032of the symbol by which it will be externally referenced. The name @var{name}
7033itself is merely a name of convenience that is used so that it is possible to
7034have definitions for multiple versions of a function within a single source
7035file, and so that the compiler can unambiguously know which version of a
7036function is being mentioned. The @var{nodename} portion of the alias should be
7037the name of a node specified in the version script supplied to the linker when
7038building a shared library. If you are attempting to override a versioned
7039symbol from a shared library, then @var{nodename} should correspond to the
7040nodename of the symbol you are trying to override.
339681c0
L
7041
7042If the symbol @var{name} is not defined within the file being assembled, all
7043references to @var{name} will be changed to @var{name2@@nodename}. If no
7044reference to @var{name} is made, @var{name2@@nodename} will be removed from the
7045symbol table.
79082ff0
L
7046
7047Another usage of the @code{.symver} directive is:
7048@smallexample
7049.symver @var{name}, @var{name2@@@@nodename}
7050@end smallexample
7051In this case, the symbol @var{name} must exist and be defined within
a349d9dd 7052the file being assembled. It is similar to @var{name2@@nodename}. The
79082ff0
L
7053difference is @var{name2@@@@nodename} will also be used to resolve
7054references to @var{name2} by the linker.
7055
7056The third usage of the @code{.symver} directive is:
7057@smallexample
7058.symver @var{name}, @var{name2@@@@@@nodename}
7059@end smallexample
7060When @var{name} is not defined within the
7061file being assembled, it is treated as @var{name2@@nodename}. When
7062@var{name} is defined within the file being assembled, the symbol
7063name, @var{name}, will be changed to @var{name2@@@@nodename}.
252b5132
RH
7064@end ifset
7065
7066@ifset COFF
7067@node Tag
7068@section @code{.tag @var{structname}}
7069
7070@cindex COFF structure debugging
7071@cindex structure debugging, COFF
7072@cindex @code{tag} directive
7073This directive is generated by compilers to include auxiliary debugging
7074information in the symbol table. It is only permitted inside
7075@code{.def}/@code{.endef} pairs. Tags are used to link structure
7076definitions in the symbol table with instances of those structures.
7077@ifset BOUT
7078
7079@samp{.tag} is only used when generating COFF format output; when
a4fb0134 7080@command{@value{AS}} is generating @code{b.out}, it accepts this directive but
252b5132
RH
7081ignores it.
7082@end ifset
7083@end ifset
7084
7085@node Text
7086@section @code{.text @var{subsection}}
7087
7088@cindex @code{text} directive
a4fb0134 7089Tells @command{@value{AS}} to assemble the following statements onto the end of
252b5132
RH
7090the text subsection numbered @var{subsection}, which is an absolute
7091expression. If @var{subsection} is omitted, subsection number zero
7092is used.
7093
7094@node Title
7095@section @code{.title "@var{heading}"}
7096
7097@cindex @code{title} directive
7098@cindex listing control: title line
7099Use @var{heading} as the title (second line, immediately after the
7100source file name and pagenumber) when generating assembly listings.
7101
7102This directive affects subsequent pages, as well as the current page if
7103it appears within ten lines of the top of a page.
7104
c1253627 7105@ifset COFF-ELF
252b5132 7106@node Type
c1253627
NC
7107@section @code{.type}
7108
7109This directive is used to set the type of a symbol.
7110
7111@ifset COFF
7112@ifset ELF
7113@c only print the extra heading if both COFF and ELF are set
7114@subheading COFF Version
7115@end ifset
252b5132
RH
7116
7117@cindex COFF symbol type
7118@cindex symbol type, COFF
c1253627
NC
7119@cindex @code{type} directive (COFF version)
7120For COFF targets, this directive is permitted only within
7121@code{.def}/@code{.endef} pairs. It is used like this:
7122
7123@smallexample
7124.type @var{int}
7125@end smallexample
7126
7127This records the integer @var{int} as the type attribute of a symbol table
7128entry.
252b5132 7129
c91d2e08 7130@ifset BOUT
252b5132 7131@samp{.type} is associated only with COFF format output; when
a4fb0134 7132@command{@value{AS}} is configured for @code{b.out} output, it accepts this
252b5132
RH
7133directive but ignores it.
7134@end ifset
c1253627 7135@end ifset
c91d2e08 7136
c1253627
NC
7137@ifset ELF
7138@ifset COFF
7139@c only print the extra heading if both COFF and ELF are set
7140@subheading ELF Version
7141@end ifset
c91d2e08
NC
7142
7143@cindex ELF symbol type
7144@cindex symbol type, ELF
c1253627
NC
7145@cindex @code{type} directive (ELF version)
7146For ELF targets, the @code{.type} directive is used like this:
7147
7148@smallexample
7149.type @var{name} , @var{type description}
7150@end smallexample
7151
7152This sets the type of symbol @var{name} to be either a
a349d9dd 7153function symbol or an object symbol. There are five different syntaxes
c91d2e08 7154supported for the @var{type description} field, in order to provide
28c9d252 7155compatibility with various other assemblers.
58ab4f3d
MM
7156
7157Because some of the characters used in these syntaxes (such as @samp{@@} and
7158@samp{#}) are comment characters for some architectures, some of the syntaxes
7159below do not work on all architectures. The first variant will be accepted by
7160the GNU assembler on all architectures so that variant should be used for
7161maximum portability, if you do not need to assemble your code with other
7162assemblers.
7163
7164The syntaxes supported are:
c91d2e08
NC
7165
7166@smallexample
5671778d
NC
7167 .type <name> STT_<TYPE_IN_UPPER_CASE>
7168 .type <name>,#<type>
7169 .type <name>,@@<type>
e7c33416 7170 .type <name>,%<type>
5671778d
NC
7171 .type <name>,"<type>"
7172@end smallexample
7173
7174The types supported are:
58ab4f3d 7175
5671778d
NC
7176@table @gcctabopt
7177@item STT_FUNC
7178@itemx function
7179Mark the symbol as being a function name.
c91d2e08 7180
d8045f23
NC
7181@item STT_GNU_IFUNC
7182@itemx gnu_indirect_function
7183Mark the symbol as an indirect function when evaluated during reloc
9c55345c 7184processing. (This is only supported on assemblers targeting GNU systems).
d8045f23 7185
5671778d
NC
7186@item STT_OBJECT
7187@itemx object
7188Mark the symbol as being a data object.
7189
7190@item STT_TLS
7191@itemx tls_object
33eaf5de 7192Mark the symbol as being a thread-local data object.
5671778d
NC
7193
7194@item STT_COMMON
7195@itemx common
7196Mark the symbol as being a common data object.
e7c33416
NC
7197
7198@item STT_NOTYPE
7199@itemx notype
7200Does not mark the symbol in any way. It is supported just for completeness.
7201
3e7a7d11
NC
7202@item gnu_unique_object
7203Marks the symbol as being a globally unique data object. The dynamic linker
7204will make sure that in the entire process there is just one symbol with this
9c55345c
TS
7205name and type in use. (This is only supported on assemblers targeting GNU
7206systems).
3e7a7d11 7207
5671778d
NC
7208@end table
7209
7210Note: Some targets support extra types in addition to those listed above.
c91d2e08 7211
c1253627
NC
7212@end ifset
7213@end ifset
c91d2e08
NC
7214
7215@node Uleb128
7216@section @code{.uleb128 @var{expressions}}
7217
7218@cindex @code{uleb128} directive
01642c12 7219@var{uleb128} stands for ``unsigned little endian base 128.'' This is a
c91d2e08 7220compact, variable length representation of numbers used by the DWARF
96e9638b 7221symbolic debugging format. @xref{Sleb128, ,@code{.sleb128}}.
252b5132
RH
7222
7223@ifset COFF
7224@node Val
7225@section @code{.val @var{addr}}
7226
7227@cindex @code{val} directive
7228@cindex COFF value attribute
7229@cindex value attribute, COFF
7230This directive, permitted only within @code{.def}/@code{.endef} pairs,
7231records the address @var{addr} as the value attribute of a symbol table
7232entry.
7233@ifset BOUT
7234
a4fb0134 7235@samp{.val} is used only for COFF output; when @command{@value{AS}} is
252b5132
RH
7236configured for @code{b.out}, it accepts this directive but ignores it.
7237@end ifset
7238@end ifset
7239
2e13b764 7240@ifset ELF
c91d2e08
NC
7241@node Version
7242@section @code{.version "@var{string}"}
2e13b764 7243
c1253627 7244@cindex @code{version} directive
c91d2e08
NC
7245This directive creates a @code{.note} section and places into it an ELF
7246formatted note of type NT_VERSION. The note's name is set to @code{string}.
9a297610 7247@end ifset
2e13b764 7248
c91d2e08
NC
7249@ifset ELF
7250@node VTableEntry
7251@section @code{.vtable_entry @var{table}, @var{offset}}
2e13b764 7252
653cfe85 7253@cindex @code{vtable_entry} directive
c91d2e08
NC
7254This directive finds or creates a symbol @code{table} and creates a
7255@code{VTABLE_ENTRY} relocation for it with an addend of @code{offset}.
2e13b764 7256
c91d2e08
NC
7257@node VTableInherit
7258@section @code{.vtable_inherit @var{child}, @var{parent}}
2e13b764 7259
653cfe85 7260@cindex @code{vtable_inherit} directive
c91d2e08
NC
7261This directive finds the symbol @code{child} and finds or creates the symbol
7262@code{parent} and then creates a @code{VTABLE_INHERIT} relocation for the
a349d9dd 7263parent whose addend is the value of the child symbol. As a special case the
96e9638b 7264parent name of @code{0} is treated as referring to the @code{*ABS*} section.
c91d2e08 7265@end ifset
2e13b764 7266
d190d046
HPN
7267@node Warning
7268@section @code{.warning "@var{string}"}
7269@cindex warning directive
7270Similar to the directive @code{.error}
7271(@pxref{Error,,@code{.error "@var{string}"}}), but just emits a warning.
7272
c91d2e08
NC
7273@node Weak
7274@section @code{.weak @var{names}}
2e13b764 7275
c1253627 7276@cindex @code{weak} directive
a349d9dd 7277This directive sets the weak attribute on the comma separated list of symbol
c91d2e08 7278@code{names}. If the symbols do not already exist, they will be created.
c87db184 7279
01642c12 7280On COFF targets other than PE, weak symbols are a GNU extension. This
977cdf5a 7281directive sets the weak attribute on the comma separated list of symbol
c87db184
CF
7282@code{names}. If the symbols do not already exist, they will be created.
7283
977cdf5a 7284On the PE target, weak symbols are supported natively as weak aliases.
01642c12 7285When a weak symbol is created that is not an alias, GAS creates an
977cdf5a 7286alternate symbol to hold the default value.
2e13b764 7287
06e77878
AO
7288@node Weakref
7289@section @code{.weakref @var{alias}, @var{target}}
7290
7291@cindex @code{weakref} directive
7292This directive creates an alias to the target symbol that enables the symbol to
7293be referenced with weak-symbol semantics, but without actually making it weak.
7294If direct references or definitions of the symbol are present, then the symbol
7295will not be weak, but if all references to it are through weak references, the
7296symbol will be marked as weak in the symbol table.
7297
7298The effect is equivalent to moving all references to the alias to a separate
7299assembly source file, renaming the alias to the symbol in it, declaring the
7300symbol as weak there, and running a reloadable link to merge the object files
7301resulting from the assembly of the new source file and the old source file that
7302had the references to the alias removed.
7303
7304The alias itself never makes to the symbol table, and is entirely handled
7305within the assembler.
7306
252b5132
RH
7307@node Word
7308@section @code{.word @var{expressions}}
7309
7310@cindex @code{word} directive
7311This directive expects zero or more @var{expressions}, of any section,
7312separated by commas.
7313@ifclear GENERIC
7314@ifset W32
a4fb0134 7315For each expression, @command{@value{AS}} emits a 32-bit number.
252b5132
RH
7316@end ifset
7317@ifset W16
a4fb0134 7318For each expression, @command{@value{AS}} emits a 16-bit number.
252b5132
RH
7319@end ifset
7320@end ifclear
7321@ifset GENERIC
7322
7323The size of the number emitted, and its byte order,
7324depend on what target computer the assembly is for.
7325@end ifset
7326
7327@c on amd29k, i960, sparc the "special treatment to support compilers" doesn't
7328@c happen---32-bit addressability, period; no long/short jumps.
7329@ifset DIFF-TBL-KLUGE
7330@cindex difference tables altered
7331@cindex altered difference tables
7332@quotation
7333@emph{Warning: Special Treatment to support Compilers}
7334@end quotation
7335
7336@ifset GENERIC
7337Machines with a 32-bit address space, but that do less than 32-bit
7338addressing, require the following special treatment. If the machine of
7339interest to you does 32-bit addressing (or doesn't require it;
7340@pxref{Machine Dependencies}), you can ignore this issue.
7341
7342@end ifset
7343In order to assemble compiler output into something that works,
a4fb0134 7344@command{@value{AS}} occasionally does strange things to @samp{.word} directives.
252b5132 7345Directives of the form @samp{.word sym1-sym2} are often emitted by
a4fb0134 7346compilers as part of jump tables. Therefore, when @command{@value{AS}} assembles a
252b5132 7347directive of the form @samp{.word sym1-sym2}, and the difference between
a4fb0134 7348@code{sym1} and @code{sym2} does not fit in 16 bits, @command{@value{AS}}
252b5132
RH
7349creates a @dfn{secondary jump table}, immediately before the next label.
7350This secondary jump table is preceded by a short-jump to the
7351first byte after the secondary table. This short-jump prevents the flow
7352of control from accidentally falling into the new table. Inside the
7353table is a long-jump to @code{sym2}. The original @samp{.word}
7354contains @code{sym1} minus the address of the long-jump to
7355@code{sym2}.
7356
7357If there were several occurrences of @samp{.word sym1-sym2} before the
7358secondary jump table, all of them are adjusted. If there was a
7359@samp{.word sym3-sym4}, that also did not fit in sixteen bits, a
7360long-jump to @code{sym4} is included in the secondary jump table,
7361and the @code{.word} directives are adjusted to contain @code{sym3}
7362minus the address of the long-jump to @code{sym4}; and so on, for as many
7363entries in the original jump table as necessary.
7364
7365@ifset INTERNALS
a4fb0134 7366@emph{This feature may be disabled by compiling @command{@value{AS}} with the
252b5132
RH
7367@samp{-DWORKING_DOT_WORD} option.} This feature is likely to confuse
7368assembly language programmers.
7369@end ifset
7370@end ifset
7371@c end DIFF-TBL-KLUGE
7372
7ce98c16
NC
7373@ifclear no-space-dir
7374@node Zero
7375@section @code{.zero @var{size}}
7376
7377@cindex @code{zero} directive
7378@cindex filling memory with zero bytes
7379This directive emits @var{size} 0-valued bytes. @var{size} must be an absolute
7380expression. This directive is actually an alias for the @samp{.skip} directive
7381so in can take an optional second argument of the value to store in the bytes
7382instead of zero. Using @samp{.zero} in this way would be confusing however.
7383@end ifclear
7384
2b841ec2
AM
7385@ifset ELF
7386@node 2byte
ea86f534 7387@section @code{.2byte @var{expression} [, @var{expression}]*}
2b841ec2
AM
7388@cindex @code{2byte} directive
7389@cindex two-byte integer
7390@cindex integer, 2-byte
2b841ec2 7391
e406e428
NC
7392This directive expects zero or more expressions, separated by commas. If there
7393are no expressions then the directive does nothing. Otherwise each expression
7394is evaluated in turn and placed in the next two bytes of the current output
7395section, using the endian model of the target. If an expression will not fit
7396in two bytes, a warning message is displayed and the least significant two
7397bytes of the expression's value are used. If an expression cannot be evaluated
7398at assembly time then relocations will be generated in order to compute the
7399value at link time.
7400
7401This directive does not apply any alignment before or after inserting the
7402values. As a result of this, if relocations are generated, they may be
7403different from those used for inserting values with a guaranteed alignment.
7404
8b1e5da1 7405This directive is only available for ELF targets,
2b841ec2
AM
7406
7407@node 4byte
ea86f534 7408@section @code{.4byte @var{expression} [, @var{expression}]*}
2b841ec2
AM
7409@cindex @code{4byte} directive
7410@cindex four-byte integer
7411@cindex integer, 4-byte
2b841ec2 7412
e406e428
NC
7413Like the @option{.2byte} directive, except that it inserts unaligned, four byte
7414long values into the output.
2b841ec2
AM
7415
7416@node 8byte
ea86f534 7417@section @code{.8byte @var{expression} [, @var{expression}]*}
2b841ec2
AM
7418@cindex @code{8byte} directive
7419@cindex eight-byte integer
7420@cindex integer, 8-byte
2b841ec2 7421
e21126b7 7422Like the @option{.2byte} directive, except that it inserts unaligned, eight
e406e428
NC
7423byte long bignum values into the output.
7424
2b841ec2
AM
7425@end ifset
7426
252b5132
RH
7427@node Deprecated
7428@section Deprecated Directives
7429
7430@cindex deprecated directives
7431@cindex obsolescent directives
7432One day these directives won't work.
7433They are included for compatibility with older assemblers.
7434@table @t
7435@item .abort
7436@item .line
7437@end table
7438
3a99f02f
DJ
7439@ifset ELF
7440@node Object Attributes
7441@chapter Object Attributes
7442@cindex object attributes
7443
7444@command{@value{AS}} assembles source files written for a specific architecture
7445into object files for that architecture. But not all object files are alike.
7446Many architectures support incompatible variations. For instance, floating
7447point arguments might be passed in floating point registers if the object file
7448requires hardware floating point support---or floating point arguments might be
7449passed in integer registers if the object file supports processors with no
7450hardware floating point unit. Or, if two objects are built for different
7451generations of the same architecture, the combination may require the
7452newer generation at run-time.
7453
7454This information is useful during and after linking. At link time,
7455@command{@value{LD}} can warn about incompatible object files. After link
7456time, tools like @command{gdb} can use it to process the linked file
7457correctly.
7458
7459Compatibility information is recorded as a series of object attributes. Each
7460attribute has a @dfn{vendor}, @dfn{tag}, and @dfn{value}. The vendor is a
7461string, and indicates who sets the meaning of the tag. The tag is an integer,
7462and indicates what property the attribute describes. The value may be a string
7463or an integer, and indicates how the property affects this object. Missing
7464attributes are the same as attributes with a zero value or empty string value.
7465
7466Object attributes were developed as part of the ABI for the ARM Architecture.
7467The file format is documented in @cite{ELF for the ARM Architecture}.
7468
7469@menu
7470* GNU Object Attributes:: @sc{gnu} Object Attributes
7471* Defining New Object Attributes:: Defining New Object Attributes
7472@end menu
7473
7474@node GNU Object Attributes
7475@section @sc{gnu} Object Attributes
7476
7477The @code{.gnu_attribute} directive records an object attribute
7478with vendor @samp{gnu}.
7479
7480Except for @samp{Tag_compatibility}, which has both an integer and a string for
7481its value, @sc{gnu} attributes have a string value if the tag number is odd and
7482an integer value if the tag number is even. The second bit (@code{@var{tag} &
74832} is set for architecture-independent attributes and clear for
7484architecture-dependent ones.
7485
7486@subsection Common @sc{gnu} attributes
7487
7488These attributes are valid on all architectures.
7489
7490@table @r
7491@item Tag_compatibility (32)
7492The compatibility attribute takes an integer flag value and a vendor name. If
7493the flag value is 0, the file is compatible with other toolchains. If it is 1,
7494then the file is only compatible with the named toolchain. If it is greater
7495than 1, the file can only be processed by other toolchains under some private
7496arrangement indicated by the flag value and the vendor name.
7497@end table
7498
7499@subsection MIPS Attributes
7500
7501@table @r
7502@item Tag_GNU_MIPS_ABI_FP (4)
7503The floating-point ABI used by this object file. The value will be:
7504
7505@itemize @bullet
7506@item
75070 for files not affected by the floating-point ABI.
7508@item
f179c512
MF
75091 for files using the hardware floating-point ABI with a standard
7510double-precision FPU.
3a99f02f
DJ
7511@item
75122 for files using the hardware floating-point ABI with a single-precision FPU.
7513@item
75143 for files using the software floating-point ABI.
42554f6a 7515@item
f179c512
MF
75164 for files using the deprecated hardware floating-point ABI which used 64-bit
7517floating-point registers, 32-bit general-purpose registers and increased the
7518number of callee-saved floating-point registers.
7519@item
75205 for files using the hardware floating-point ABI with a double-precision FPU
7521with either 32-bit or 64-bit floating-point registers and 32-bit
7522general-purpose registers.
7523@item
75246 for files using the hardware floating-point ABI with 64-bit floating-point
7525registers and 32-bit general-purpose registers.
7526@item
75277 for files using the hardware floating-point ABI with 64-bit floating-point
7528registers, 32-bit general-purpose registers and a rule that forbids the
7529direct use of odd-numbered single-precision floating-point registers.
3a99f02f
DJ
7530@end itemize
7531@end table
7532
7533@subsection PowerPC Attributes
7534
7535@table @r
7536@item Tag_GNU_Power_ABI_FP (4)
7537The floating-point ABI used by this object file. The value will be:
7538
7539@itemize @bullet
7540@item
75410 for files not affected by the floating-point ABI.
7542@item
3c7b9897 75431 for files using double-precision hardware floating-point ABI.
3a99f02f
DJ
7544@item
75452 for files using the software floating-point ABI.
3c7b9897
AM
7546@item
75473 for files using single-precision hardware floating-point ABI.
3a99f02f
DJ
7548@end itemize
7549
7550@item Tag_GNU_Power_ABI_Vector (8)
7551The vector ABI used by this object file. The value will be:
7552
7553@itemize @bullet
7554@item
75550 for files not affected by the vector ABI.
7556@item
75571 for files using general purpose registers to pass vectors.
7558@item
75592 for files using AltiVec registers to pass vectors.
7560@item
75613 for files using SPE registers to pass vectors.
7562@end itemize
7563@end table
7564
643f7afb
AK
7565@subsection IBM z Systems Attributes
7566
7567@table @r
7568@item Tag_GNU_S390_ABI_Vector (8)
7569The vector ABI used by this object file. The value will be:
7570
7571@itemize @bullet
7572@item
75730 for files not affected by the vector ABI.
7574@item
75751 for files using software vector ABI.
7576@item
75772 for files using hardware vector ABI.
7578@end itemize
7579@end table
7580
3a99f02f
DJ
7581@node Defining New Object Attributes
7582@section Defining New Object Attributes
7583
7584If you want to define a new @sc{gnu} object attribute, here are the places you
7585will need to modify. New attributes should be discussed on the @samp{binutils}
7586mailing list.
7587
7588@itemize @bullet
7589@item
7590This manual, which is the official register of attributes.
7591@item
7592The header for your architecture @file{include/elf}, to define the tag.
7593@item
7594The @file{bfd} support file for your architecture, to merge the attribute
7595and issue any appropriate link warnings.
7596@item
7597Test cases in @file{ld/testsuite} for merging and link warnings.
7598@item
7599@file{binutils/readelf.c} to display your attribute.
7600@item
7601GCC, if you want the compiler to mark the attribute automatically.
7602@end itemize
7603
7604@end ifset
7605
252b5132
RH
7606@ifset GENERIC
7607@node Machine Dependencies
7608@chapter Machine Dependent Features
7609
7610@cindex machine dependencies
7611The machine instruction sets are (almost by definition) different on
a4fb0134
SC
7612each machine where @command{@value{AS}} runs. Floating point representations
7613vary as well, and @command{@value{AS}} often supports a few additional
252b5132
RH
7614directives or command-line options for compatibility with other
7615assemblers on a particular platform. Finally, some versions of
a4fb0134 7616@command{@value{AS}} support special pseudo-instructions for branch
252b5132
RH
7617optimization.
7618
7619This chapter discusses most of these differences, though it does not
7620include details on any machine's instruction set. For details on that
7621subject, see the hardware manufacturer's manual.
7622
7623@menu
a06ea964
NC
7624@ifset AARCH64
7625* AArch64-Dependent:: AArch64 Dependent Features
7626@end ifset
625e1353
RH
7627@ifset ALPHA
7628* Alpha-Dependent:: Alpha Dependent Features
7629@end ifset
252b5132
RH
7630@ifset ARC
7631* ARC-Dependent:: ARC Dependent Features
7632@end ifset
7633@ifset ARM
7634* ARM-Dependent:: ARM Dependent Features
7635@end ifset
8473f7a4
DC
7636@ifset AVR
7637* AVR-Dependent:: AVR Dependent Features
7638@end ifset
3b4e1885
JZ
7639@ifset Blackfin
7640* Blackfin-Dependent:: Blackfin Dependent Features
07c1b327 7641@end ifset
3d3d428f
NC
7642@ifset CR16
7643* CR16-Dependent:: CR16 Dependent Features
7644@end ifset
8bf549a8 7645@ifset CRIS
328eb32e
HPN
7646* CRIS-Dependent:: CRIS Dependent Features
7647@end ifset
252b5132
RH
7648@ifset D10V
7649* D10V-Dependent:: D10V Dependent Features
7650@end ifset
7651@ifset D30V
7652* D30V-Dependent:: D30V Dependent Features
7653@end ifset
cfb8c092
NC
7654@ifset EPIPHANY
7655* Epiphany-Dependent:: EPIPHANY Dependent Features
7656@end ifset
252b5132 7657@ifset H8/300
c2dcd04e 7658* H8/300-Dependent:: Renesas H8/300 Dependent Features
252b5132 7659@end ifset
252b5132
RH
7660@ifset HPPA
7661* HPPA-Dependent:: HPPA Dependent Features
7662@end ifset
5b93d8bb
AM
7663@ifset I370
7664* ESA/390-Dependent:: IBM ESA/390 Dependent Features
7665@end ifset
252b5132 7666@ifset I80386
55b62671 7667* i386-Dependent:: Intel 80386 and AMD x86-64 Dependent Features
252b5132 7668@end ifset
e3308d0d
JE
7669@ifset I860
7670* i860-Dependent:: Intel 80860 Dependent Features
7671@end ifset
252b5132
RH
7672@ifset I960
7673* i960-Dependent:: Intel 80960 Dependent Features
7674@end ifset
5cb53c21
L
7675@ifset IA64
7676* IA-64-Dependent:: Intel IA-64 Dependent Features
7677@end ifset
a40cbfa3
NC
7678@ifset IP2K
7679* IP2K-Dependent:: IP2K Dependent Features
7680@end ifset
84e94c90
NC
7681@ifset LM32
7682* LM32-Dependent:: LM32 Dependent Features
7683@end ifset
49f58d10
JB
7684@ifset M32C
7685* M32C-Dependent:: M32C Dependent Features
7686@end ifset
ec694b89
NC
7687@ifset M32R
7688* M32R-Dependent:: M32R Dependent Features
7689@end ifset
252b5132
RH
7690@ifset M680X0
7691* M68K-Dependent:: M680x0 Dependent Features
7692@end ifset
60bcf0fa
NC
7693@ifset M68HC11
7694* M68HC11-Dependent:: M68HC11 and 68HC12 Dependent Features
7695@end ifset
a3c62988
NC
7696@ifset METAG
7697* Meta-Dependent :: Meta Dependent Features
7698@end ifset
7ba29e2a
NC
7699@ifset MICROBLAZE
7700* MicroBlaze-Dependent:: MICROBLAZE Dependent Features
7701@end ifset
252b5132
RH
7702@ifset MIPS
7703* MIPS-Dependent:: MIPS Dependent Features
7704@end ifset
3c3bdf30
NC
7705@ifset MMIX
7706* MMIX-Dependent:: MMIX Dependent Features
7707@end ifset
2469cfa2
NC
7708@ifset MSP430
7709* MSP430-Dependent:: MSP430 Dependent Features
7710@end ifset
35c08157
KLC
7711@ifset NDS32
7712* NDS32-Dependent:: Andes NDS32 Dependent Features
7713@end ifset
36591ba1
SL
7714@ifset NIOSII
7715* NiosII-Dependent:: Altera Nios II Dependent Features
7716@end ifset
7c31ae13
NC
7717@ifset NS32K
7718* NS32K-Dependent:: NS32K Dependent Features
7719@end ifset
e135f41b
NC
7720@ifset PDP11
7721* PDP-11-Dependent:: PDP-11 Dependent Features
7722@end ifset
041dd5a9
ILT
7723@ifset PJ
7724* PJ-Dependent:: picoJava Dependent Features
7725@end ifset
418c1742
MG
7726@ifset PPC
7727* PPC-Dependent:: PowerPC Dependent Features
7728@end ifset
93f11b16
DD
7729@ifset PRU
7730* PRU-Dependent:: PRU Dependent Features
7731@end ifset
4f7eddc4
PD
7732@ifset RISCV
7733* RISC-V-Dependent:: RISC-V Dependent Features
7734@end ifset
b57e49f7
JW
7735@ifset RL78
7736* RL78-Dependent:: RL78 Dependent Features
7737@end ifset
046d31c2
NC
7738@ifset RX
7739* RX-Dependent:: RX Dependent Features
7740@end ifset
11c19e16
MS
7741@ifset S390
7742* S/390-Dependent:: IBM S/390 Dependent Features
7743@end ifset
c0157db4
NC
7744@ifset SCORE
7745* SCORE-Dependent:: SCORE Dependent Features
7746@end ifset
d3b47e2b
L
7747@ifset SH
7748* SH-Dependent:: Renesas / SuperH SH Dependent Features
7749* SH64-Dependent:: SuperH SH64 Dependent Features
7750@end ifset
252b5132
RH
7751@ifset SPARC
7752* Sparc-Dependent:: SPARC Dependent Features
7753@end ifset
39bec121
TW
7754@ifset TIC54X
7755* TIC54X-Dependent:: TI TMS320C54x Dependent Features
7756@end ifset
40b36596
JM
7757@ifset TIC6X
7758* TIC6X-Dependent :: TI TMS320C6x Dependent Features
7759@end ifset
aa137e4d
NC
7760@ifset TILEGX
7761* TILE-Gx-Dependent :: Tilera TILE-Gx Dependent Features
7762@end ifset
7763@ifset TILEPRO
7764* TILEPro-Dependent :: Tilera TILEPro Dependent Features
7765@end ifset
252b5132
RH
7766@ifset V850
7767* V850-Dependent:: V850 Dependent Features
7768@end ifset
b6605ddd
EB
7769@ifset VAX
7770* Vax-Dependent:: VAX Dependent Features
7771@end ifset
7772@ifset VISIUM
7773* Visium-Dependent:: Visium Dependent Features
7774@end ifset
f96bd6c2
PC
7775@ifset WASM32
7776* WebAssembly-Dependent:: WebAssembly Dependent Features
7777@end ifset
f6c1a2d5 7778@ifset XGATE
f96bd6c2 7779* XGATE-Dependent:: XGATE Dependent Features
f6c1a2d5 7780@end ifset
6753e72f
NC
7781@ifset XSTORMY16
7782* XSTORMY16-Dependent:: XStormy16 Dependent Features
7783@end ifset
e0001a05
NC
7784@ifset XTENSA
7785* Xtensa-Dependent:: Xtensa Dependent Features
7786@end ifset
3c9b82ba
NC
7787@ifset Z80
7788* Z80-Dependent:: Z80 Dependent Features
7789@end ifset
252b5132
RH
7790@ifset Z8000
7791* Z8000-Dependent:: Z8000 Dependent Features
7792@end ifset
252b5132
RH
7793@end menu
7794
7795@lowersections
7796@end ifset
7797
7798@c The following major nodes are *sections* in the GENERIC version, *chapters*
7799@c in single-cpu versions. This is mainly achieved by @lowersections. There is a
7800@c peculiarity: to preserve cross-references, there must be a node called
7801@c "Machine Dependencies". Hence the conditional nodenames in each
7802@c major node below. Node defaulting in makeinfo requires adjacency of
7803@c node and sectioning commands; hence the repetition of @chapter BLAH
7804@c in both conditional blocks.
7805
a06ea964
NC
7806@ifset AARCH64
7807@include c-aarch64.texi
7808@end ifset
7809
625e1353
RH
7810@ifset ALPHA
7811@include c-alpha.texi
7812@end ifset
7813
7814@ifset ARC
7815@include c-arc.texi
7816@end ifset
7817
252b5132
RH
7818@ifset ARM
7819@include c-arm.texi
7820@end ifset
7821
8473f7a4
DC
7822@ifset AVR
7823@include c-avr.texi
7824@end ifset
7825
3b4e1885 7826@ifset Blackfin
07c1b327
CM
7827@include c-bfin.texi
7828@end ifset
7829
3d3d428f
NC
7830@ifset CR16
7831@include c-cr16.texi
7832@end ifset
7833
328eb32e
HPN
7834@ifset CRIS
7835@include c-cris.texi
7836@end ifset
7837
c2dcd04e 7838@ifset Renesas-all
252b5132
RH
7839@ifclear GENERIC
7840@node Machine Dependencies
7841@chapter Machine Dependent Features
7842
c2dcd04e 7843The machine instruction sets are different on each Renesas chip family,
252b5132 7844and there are also some syntax differences among the families. This
a4fb0134 7845chapter describes the specific @command{@value{AS}} features for each
252b5132
RH
7846family.
7847
7848@menu
c2dcd04e 7849* H8/300-Dependent:: Renesas H8/300 Dependent Features
c2dcd04e 7850* SH-Dependent:: Renesas SH Dependent Features
252b5132
RH
7851@end menu
7852@lowersections
7853@end ifclear
7854@end ifset
7855
7856@ifset D10V
7857@include c-d10v.texi
7858@end ifset
7859
7860@ifset D30V
7861@include c-d30v.texi
7862@end ifset
7863
cfb8c092
NC
7864@ifset EPIPHANY
7865@include c-epiphany.texi
7866@end ifset
7867
252b5132
RH
7868@ifset H8/300
7869@include c-h8300.texi
7870@end ifset
7871
252b5132
RH
7872@ifset HPPA
7873@include c-hppa.texi
7874@end ifset
7875
5b93d8bb
AM
7876@ifset I370
7877@include c-i370.texi
7878@end ifset
7879
252b5132
RH
7880@ifset I80386
7881@include c-i386.texi
7882@end ifset
7883
e3308d0d
JE
7884@ifset I860
7885@include c-i860.texi
7886@end ifset
7887
252b5132
RH
7888@ifset I960
7889@include c-i960.texi
7890@end ifset
7891
9e32ca89
NC
7892@ifset IA64
7893@include c-ia64.texi
7894@end ifset
7895
a40cbfa3
NC
7896@ifset IP2K
7897@include c-ip2k.texi
7898@end ifset
7899
84e94c90
NC
7900@ifset LM32
7901@include c-lm32.texi
7902@end ifset
7903
49f58d10
JB
7904@ifset M32C
7905@include c-m32c.texi
7906@end ifset
7907
ec694b89
NC
7908@ifset M32R
7909@include c-m32r.texi
7910@end ifset
252b5132
RH
7911
7912@ifset M680X0
7913@include c-m68k.texi
7914@end ifset
7915
60bcf0fa
NC
7916@ifset M68HC11
7917@include c-m68hc11.texi
7918@end ifset
7919
a3c62988
NC
7920@ifset METAG
7921@include c-metag.texi
7922@end ifset
7923
01642c12 7924@ifset MICROBLAZE
7ba29e2a
NC
7925@include c-microblaze.texi
7926@end ifset
7927
252b5132
RH
7928@ifset MIPS
7929@include c-mips.texi
7930@end ifset
7931
3c3bdf30
NC
7932@ifset MMIX
7933@include c-mmix.texi
7934@end ifset
7935
2469cfa2
NC
7936@ifset MSP430
7937@include c-msp430.texi
7938@end ifset
7939
35c08157
KLC
7940@ifset NDS32
7941@include c-nds32.texi
7942@end ifset
7943
36591ba1
SL
7944@ifset NIOSII
7945@include c-nios2.texi
7946@end ifset
7947
252b5132
RH
7948@ifset NS32K
7949@include c-ns32k.texi
7950@end ifset
7951
e135f41b
NC
7952@ifset PDP11
7953@include c-pdp11.texi
7954@end ifset
7955
041dd5a9
ILT
7956@ifset PJ
7957@include c-pj.texi
7958@end ifset
7959
418c1742
MG
7960@ifset PPC
7961@include c-ppc.texi
7962@end ifset
7963
93f11b16
DD
7964@ifset PRU
7965@include c-pru.texi
7966@end ifset
7967
4f7eddc4
PD
7968@ifset RISCV
7969@include c-riscv.texi
7970@end ifset
7971
b57e49f7
JW
7972@ifset RL78
7973@include c-rl78.texi
7974@end ifset
7975
046d31c2
NC
7976@ifset RX
7977@include c-rx.texi
7978@end ifset
7979
11c19e16
MS
7980@ifset S390
7981@include c-s390.texi
7982@end ifset
7983
c0157db4
NC
7984@ifset SCORE
7985@include c-score.texi
7986@end ifset
7987
252b5132
RH
7988@ifset SH
7989@include c-sh.texi
324bfcf3 7990@include c-sh64.texi
252b5132
RH
7991@end ifset
7992
7993@ifset SPARC
7994@include c-sparc.texi
7995@end ifset
7996
39bec121
TW
7997@ifset TIC54X
7998@include c-tic54x.texi
7999@end ifset
8000
40b36596
JM
8001@ifset TIC6X
8002@include c-tic6x.texi
8003@end ifset
8004
aa137e4d
NC
8005@ifset TILEGX
8006@include c-tilegx.texi
8007@end ifset
8008
8009@ifset TILEPRO
8010@include c-tilepro.texi
8011@end ifset
8012
b6605ddd
EB
8013@ifset V850
8014@include c-v850.texi
252b5132
RH
8015@end ifset
8016
8017@ifset VAX
8018@include c-vax.texi
8019@end ifset
8020
b6605ddd
EB
8021@ifset VISIUM
8022@include c-visium.texi
252b5132
RH
8023@end ifset
8024
f96bd6c2
PC
8025@ifset WASM32
8026@include c-wasm32.texi
8027@end ifset
8028
f6c1a2d5
NC
8029@ifset XGATE
8030@include c-xgate.texi
8031@end ifset
8032
6753e72f
NC
8033@ifset XSTORMY16
8034@include c-xstormy16.texi
8035@end ifset
8036
e0001a05
NC
8037@ifset XTENSA
8038@include c-xtensa.texi
8039@end ifset
8040
b6605ddd
EB
8041@ifset Z80
8042@include c-z80.texi
8043@end ifset
8044
8045@ifset Z8000
8046@include c-z8k.texi
8047@end ifset
8048
252b5132
RH
8049@ifset GENERIC
8050@c reverse effect of @down at top of generic Machine-Dep chapter
8051@raisesections
8052@end ifset
8053
8054@node Reporting Bugs
8055@chapter Reporting Bugs
8056@cindex bugs in assembler
8057@cindex reporting bugs in assembler
8058
a4fb0134 8059Your bug reports play an essential role in making @command{@value{AS}} reliable.
252b5132
RH
8060
8061Reporting a bug may help you by bringing a solution to your problem, or it may
8062not. But in any case the principal function of a bug report is to help the
a4fb0134
SC
8063entire community by making the next version of @command{@value{AS}} work better.
8064Bug reports are your contribution to the maintenance of @command{@value{AS}}.
252b5132
RH
8065
8066In order for a bug report to serve its purpose, you must include the
8067information that enables us to fix the bug.
8068
8069@menu
8070* Bug Criteria:: Have you found a bug?
8071* Bug Reporting:: How to report bugs
8072@end menu
8073
8074@node Bug Criteria
c1253627 8075@section Have You Found a Bug?
252b5132
RH
8076@cindex bug criteria
8077
8078If you are not sure whether you have found a bug, here are some guidelines:
8079
8080@itemize @bullet
8081@cindex fatal signal
8082@cindex assembler crash
8083@cindex crash of assembler
8084@item
8085If the assembler gets a fatal signal, for any input whatever, that is a
a4fb0134 8086@command{@value{AS}} bug. Reliable assemblers never crash.
252b5132
RH
8087
8088@cindex error on valid input
8089@item
a4fb0134 8090If @command{@value{AS}} produces an error message for valid input, that is a bug.
252b5132
RH
8091
8092@cindex invalid input
8093@item
a4fb0134 8094If @command{@value{AS}} does not produce an error message for invalid input, that
252b5132
RH
8095is a bug. However, you should note that your idea of ``invalid input'' might
8096be our idea of ``an extension'' or ``support for traditional practice''.
8097
8098@item
8099If you are an experienced user of assemblers, your suggestions for improvement
a4fb0134 8100of @command{@value{AS}} are welcome in any case.
252b5132
RH
8101@end itemize
8102
8103@node Bug Reporting
c1253627 8104@section How to Report Bugs
252b5132
RH
8105@cindex bug reports
8106@cindex assembler bugs, reporting
8107
8108A number of companies and individuals offer support for @sc{gnu} products. If
a4fb0134 8109you obtained @command{@value{AS}} from a support organization, we recommend you
252b5132
RH
8110contact that organization first.
8111
8112You can find contact information for many support companies and
8113individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
8114distribution.
8115
ad22bfe8 8116@ifset BUGURL
a4fb0134 8117In any event, we also recommend that you send bug reports for @command{@value{AS}}
ad22bfe8
JM
8118to @value{BUGURL}.
8119@end ifset
252b5132
RH
8120
8121The fundamental principle of reporting bugs usefully is this:
8122@strong{report all the facts}. If you are not sure whether to state a
8123fact or leave it out, state it!
8124
8125Often people omit facts because they think they know what causes the problem
8126and assume that some details do not matter. Thus, you might assume that the
8127name of a symbol you use in an example does not matter. Well, probably it does
8128not, but one cannot be sure. Perhaps the bug is a stray memory reference which
8129happens to fetch from the location where that name is stored in memory;
8130perhaps, if the name were different, the contents of that location would fool
8131the assembler into doing the right thing despite the bug. Play it safe and
8132give a specific, complete example. That is the easiest thing for you to do,
8133and the most helpful.
8134
8135Keep in mind that the purpose of a bug report is to enable us to fix the bug if
8136it is new to us. Therefore, always write your bug reports on the assumption
8137that the bug has not been reported previously.
8138
8139Sometimes people give a few sketchy facts and ask, ``Does this ring a
c1253627
NC
8140bell?'' This cannot help us fix a bug, so it is basically useless. We
8141respond by asking for enough details to enable us to investigate.
8142You might as well expedite matters by sending them to begin with.
252b5132
RH
8143
8144To enable us to fix the bug, you should include all these things:
8145
8146@itemize @bullet
8147@item
a4fb0134 8148The version of @command{@value{AS}}. @command{@value{AS}} announces it if you start
252b5132
RH
8149it with the @samp{--version} argument.
8150
8151Without this, we will not know whether there is any point in looking for
a4fb0134 8152the bug in the current version of @command{@value{AS}}.
252b5132
RH
8153
8154@item
a4fb0134 8155Any patches you may have applied to the @command{@value{AS}} source.
252b5132
RH
8156
8157@item
8158The type of machine you are using, and the operating system name and
8159version number.
8160
8161@item
a4fb0134 8162What compiler (and its version) was used to compile @command{@value{AS}}---e.g.
252b5132
RH
8163``@code{gcc-2.7}''.
8164
8165@item
8166The command arguments you gave the assembler to assemble your example and
8167observe the bug. To guarantee you will not omit something important, list them
8168all. A copy of the Makefile (or the output from make) is sufficient.
8169
8170If we were to try to guess the arguments, we would probably guess wrong
8171and then we might not encounter the bug.
8172
8173@item
8174A complete input file that will reproduce the bug. If the bug is observed when
8175the assembler is invoked via a compiler, send the assembler source, not the
8176high level language source. Most compilers will produce the assembler source
8177when run with the @samp{-S} option. If you are using @code{@value{GCC}}, use
8178the options @samp{-v --save-temps}; this will save the assembler source in a
8179file with an extension of @file{.s}, and also show you exactly how
a4fb0134 8180@command{@value{AS}} is being run.
252b5132
RH
8181
8182@item
8183A description of what behavior you observe that you believe is
8184incorrect. For example, ``It gets a fatal signal.''
8185
a4fb0134 8186Of course, if the bug is that @command{@value{AS}} gets a fatal signal, then we
252b5132
RH
8187will certainly notice it. But if the bug is incorrect output, we might not
8188notice unless it is glaringly wrong. You might as well not give us a chance to
8189make a mistake.
8190
8191Even if the problem you experience is a fatal signal, you should still say so
8192explicitly. Suppose something strange is going on, such as, your copy of
b45619c0 8193@command{@value{AS}} is out of sync, or you have encountered a bug in the C
252b5132
RH
8194library on your system. (This has happened!) Your copy might crash and ours
8195would not. If you told us to expect a crash, then when ours fails to crash, we
8196would know that the bug was not happening for us. If you had not told us to
8197expect a crash, then we would not be able to draw any conclusion from our
8198observations.
8199
8200@item
a4fb0134 8201If you wish to suggest changes to the @command{@value{AS}} source, send us context
252b5132
RH
8202diffs, as generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
8203option. Always send diffs from the old file to the new file. If you even
a4fb0134 8204discuss something in the @command{@value{AS}} source, refer to it by context, not
252b5132
RH
8205by line number.
8206
8207The line numbers in our development sources will not match those in your
8208sources. Your line numbers would convey no useful information to us.
8209@end itemize
8210
8211Here are some things that are not necessary:
8212
8213@itemize @bullet
8214@item
8215A description of the envelope of the bug.
8216
8217Often people who encounter a bug spend a lot of time investigating
8218which changes to the input file will make the bug go away and which
8219changes will not affect it.
8220
8221This is often time consuming and not very useful, because the way we
8222will find the bug is by running a single example under the debugger
8223with breakpoints, not by pure deduction from a series of examples.
8224We recommend that you save your time for something else.
8225
8226Of course, if you can find a simpler example to report @emph{instead}
8227of the original one, that is a convenience for us. Errors in the
8228output will be easier to spot, running under the debugger will take
8229less time, and so on.
8230
8231However, simplification is not vital; if you do not want to do this,
8232report the bug anyway and send us the entire test case you used.
8233
8234@item
8235A patch for the bug.
8236
8237A patch for the bug does help us if it is a good one. But do not omit
8238the necessary information, such as the test case, on the assumption that
8239a patch is all we need. We might see problems with your patch and decide
8240to fix the problem another way, or we might not understand it at all.
8241
a4fb0134 8242Sometimes with a program as complicated as @command{@value{AS}} it is very hard to
252b5132
RH
8243construct an example that will make the program follow a certain path through
8244the code. If you do not send us the example, we will not be able to construct
8245one, so we will not be able to verify that the bug is fixed.
8246
8247And if we cannot understand what bug you are trying to fix, or why your
8248patch should be an improvement, we will not install it. A test case will
8249help us to understand.
8250
8251@item
8252A guess about what the bug is or what it depends on.
8253
8254Such guesses are usually wrong. Even we cannot guess right about such
8255things without first using the debugger to find the facts.
8256@end itemize
8257
8258@node Acknowledgements
8259@chapter Acknowledgements
8260
653cfe85 8261If you have contributed to GAS and your name isn't listed here,
252b5132 8262it is not meant as a slight. We just don't know about it. Send mail to the
01642c12 8263maintainer, and we'll correct the situation. Currently
3bfcb652
NC
8264@c (October 2012),
8265the maintainer is Nick Clifton (email address @code{nickc@@redhat.com}).
252b5132
RH
8266
8267Dean Elsner wrote the original @sc{gnu} assembler for the VAX.@footnote{Any
8268more details?}
8269
8270Jay Fenlason maintained GAS for a while, adding support for GDB-specific debug
8271information and the 68k series machines, most of the preprocessing pass, and
8272extensive changes in @file{messages.c}, @file{input-file.c}, @file{write.c}.
8273
8274K. Richard Pixley maintained GAS for a while, adding various enhancements and
8275many bug fixes, including merging support for several processors, breaking GAS
8276up to handle multiple object file format back ends (including heavy rewrite,
8277testing, an integration of the coff and b.out back ends), adding configuration
8278including heavy testing and verification of cross assemblers and file splits
8279and renaming, converted GAS to strictly ANSI C including full prototypes, added
8280support for m680[34]0 and cpu32, did considerable work on i960 including a COFF
8281port (including considerable amounts of reverse engineering), a SPARC opcode
8282file rewrite, DECstation, rs6000, and hp300hpux host ports, updated ``know''
8283assertions and made them work, much other reorganization, cleanup, and lint.
8284
8285Ken Raeburn wrote the high-level BFD interface code to replace most of the code
8286in format-specific I/O modules.
8287
8288The original VMS support was contributed by David L. Kashtan. Eric Youngdale
8289has done much work with it since.
8290
8291The Intel 80386 machine description was written by Eliot Dresselhaus.
8292
8293Minh Tran-Le at IntelliCorp contributed some AIX 386 support.
8294
8295The Motorola 88k machine description was contributed by Devon Bowen of Buffalo
8296University and Torbjorn Granlund of the Swedish Institute of Computer Science.
8297
8298Keith Knowles at the Open Software Foundation wrote the original MIPS back end
8299(@file{tc-mips.c}, @file{tc-mips.h}), and contributed Rose format support
8300(which hasn't been merged in yet). Ralph Campbell worked with the MIPS code to
8301support a.out format.
8302
7be1c489
AM
8303Support for the Zilog Z8k and Renesas H8/300 processors (tc-z8k,
8304tc-h8300), and IEEE 695 object file format (obj-ieee), was written by
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RH
8305Steve Chamberlain of Cygnus Support. Steve also modified the COFF back end to
8306use BFD for some low-level operations, for use with the H8/300 and AMD 29k
8307targets.
8308
8309John Gilmore built the AMD 29000 support, added @code{.include} support, and
8310simplified the configuration of which versions accept which directives. He
8311updated the 68k machine description so that Motorola's opcodes always produced
c1253627 8312fixed-size instructions (e.g., @code{jsr}), while synthetic instructions
252b5132
RH
8313remained shrinkable (@code{jbsr}). John fixed many bugs, including true tested
8314cross-compilation support, and one bug in relaxation that took a week and
8315required the proverbial one-bit fix.
8316
8317Ian Lance Taylor of Cygnus Support merged the Motorola and MIT syntax for the
831868k, completed support for some COFF targets (68k, i386 SVR3, and SCO Unix),
8319added support for MIPS ECOFF and ELF targets, wrote the initial RS/6000 and
8320PowerPC assembler, and made a few other minor patches.
8321
653cfe85 8322Steve Chamberlain made GAS able to generate listings.
252b5132
RH
8323
8324Hewlett-Packard contributed support for the HP9000/300.
8325
8326Jeff Law wrote GAS and BFD support for the native HPPA object format (SOM)
8327along with a fairly extensive HPPA testsuite (for both SOM and ELF object
8328formats). This work was supported by both the Center for Software Science at
8329the University of Utah and Cygnus Support.
8330
8331Support for ELF format files has been worked on by Mark Eichin of Cygnus
8332Support (original, incomplete implementation for SPARC), Pete Hoogenboom and
8333Jeff Law at the University of Utah (HPPA mainly), Michael Meissner of the Open
8334Software Foundation (i386 mainly), and Ken Raeburn of Cygnus Support (sparc,
8335and some initial 64-bit support).
8336
c1253627 8337Linas Vepstas added GAS support for the ESA/390 ``IBM 370'' architecture.
5b93d8bb 8338
252b5132
RH
8339Richard Henderson rewrote the Alpha assembler. Klaus Kaempf wrote GAS and BFD
8340support for openVMS/Alpha.
8341
39bec121
TW
8342Timothy Wall, Michael Hayes, and Greg Smart contributed to the various tic*
8343flavors.
8344
e0001a05 8345David Heine, Sterling Augustine, Bob Wilson and John Ruttenberg from Tensilica,
b45619c0 8346Inc.@: added support for Xtensa processors.
e0001a05 8347
252b5132
RH
8348Several engineers at Cygnus Support have also provided many small bug fixes and
8349configuration enhancements.
8350
84e94c90
NC
8351Jon Beniston added support for the Lattice Mico32 architecture.
8352
252b5132
RH
8353Many others have contributed large or small bugfixes and enhancements. If
8354you have contributed significant work and are not mentioned on this list, and
8355want to be, let us know. Some of the history has been lost; we are not
8356intentionally leaving anyone out.
8357
793c5807
NC
8358@node GNU Free Documentation License
8359@appendix GNU Free Documentation License
c1253627 8360@include fdl.texi
cf055d54 8361
370b66a1
CD
8362@node AS Index
8363@unnumbered AS Index
252b5132
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8364
8365@printindex cp
8366
252b5132
RH
8367@bye
8368@c Local Variables:
8369@c fill-column: 79
8370@c End:
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