\input texinfo @c -*-Texinfo-*-
@c Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
-@c 2001, 2002, 2003, 2004
+@c 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
@c Free Software Foundation, Inc.
@c UPDATE!! On future updates--
@c (1) check for new machine-dep cmdline options in
@c man begin NAME
@c ---
@include asconfig.texi
-@include gasver.texi
+@include bfdver.texi
@c ---
@c man end
@c ---
@ifset H8/300
@set H8
@end ifset
-@ifset H8/500
-@set H8
-@end ifset
@ifset SH
@set H8
@end ifset
@finalout
@syncodeindex ky cp
-@ifinfo
+@copying
This file documents the GNU Assembler "@value{AS}".
@c man begin COPYRIGHT
-Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002 Free Software Foundation, Inc.
+Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
+2006, 2007, 2008 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1
+under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts. A copy of the license is included in the
section entitled ``GNU Free Documentation License''.
@c man end
-
-@ignore
-Permission is granted to process this file through Tex and print the
-results, provided the printed document carries copying permission
-notice identical to this one except for the removal of this paragraph
-(this paragraph not being relevant to the printed manual).
-
-@end ignore
-@end ifinfo
+@end copying
@titlepage
@title Using @value{AS}
@ifclear GENERIC
@subtitle for the @value{TARGET} family
@end ifclear
+@ifset VERSION_PACKAGE
+@sp 1
+@subtitle @value{VERSION_PACKAGE}
+@end ifset
@sp 1
@subtitle Version @value{VERSION}
@sp 1
@sp 13
-The Free Software Foundation Inc. thanks The Nice Computer
+The Free Software Foundation Inc.@: thanks The Nice Computer
Company of Australia for loaning Dean Elsner to write the
first (Vax) version of @command{as} for Project @sc{gnu}.
The proprietors, management and staff of TNCCA thank FSF for
@end tex
@vskip 0pt plus 1filll
-Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002 Free Software Foundation, Inc.
+Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
+2006, 2007, 2008 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
- under the terms of the GNU Free Documentation License, Version 1.1
+ under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts. A copy of the license is included in the
section entitled ``GNU Free Documentation License''.
@end titlepage
+@contents
@ifnottex
@node Top
@top Using @value{AS}
-This file is a user guide to the @sc{gnu} assembler @command{@value{AS}} version
-@value{VERSION}.
+This file is a user guide to the @sc{gnu} assembler @command{@value{AS}}
+@ifset VERSION_PACKAGE
+@value{VERSION_PACKAGE}
+@end ifset
+version @value{VERSION}.
@ifclear GENERIC
This version of the file describes @command{@value{AS}} configured to generate
code for @value{TARGET} architectures.
* Symbols:: Symbols
* Expressions:: Expressions
* Pseudo Ops:: Assembler Directives
+@ifset ELF
+* Object Attributes:: Object Attributes
+@end ifset
* Machine Dependencies:: Machine Dependent Features
* Reporting Bugs:: Reporting Bugs
* Acknowledgements:: Who Did What
* GNU Free Documentation License:: GNU Free Documentation License
-* Index:: Index
+* AS Index:: AS Index
@end menu
@end ifnottex
@cindex option summary
@cindex summary of options
Here is a brief summary of how to invoke @command{@value{AS}}. For details,
-@pxref{Invoking,,Command-Line Options}.
+see @ref{Invoking,,Command-Line Options}.
@c man title AS the portable GNU assembler.
@c to be limited to one line for the header.
@smallexample
@c man begin SYNOPSIS
-@value{AS} [@b{-a}[@b{cdhlns}][=@var{file}]] [@b{--alternate}] [@b{-D}]
- [@b{--defsym} @var{sym}=@var{val}] [@b{-f}] [@b{-g}] [@b{--gstabs}] [@b{--gstabs+}]
- [@b{--gdwarf-2}] [@b{--help}] [@b{-I} @var{dir}] [@b{-J}] [@b{-K}] [@b{-L}]
- [@b{--listing-lhs-width}=@var{NUM}] [@b{--listing-lhs-width2}=@var{NUM}]
- [@b{--listing-rhs-width}=@var{NUM}] [@b{--listing-cont-lines}=@var{NUM}]
- [@b{--keep-locals}] [@b{-o} @var{objfile}] [@b{-R}] [@b{--statistics}] [@b{-v}]
- [@b{-version}] [@b{--version}] [@b{-W}] [@b{--warn}] [@b{--fatal-warnings}]
- [@b{-w}] [@b{-x}] [@b{-Z}] [@b{--target-help}] [@var{target-options}]
+@value{AS} [@b{-a}[@b{cdghlns}][=@var{file}]] [@b{--alternate}] [@b{-D}]
+ [@b{--debug-prefix-map} @var{old}=@var{new}]
+ [@b{--defsym} @var{sym}=@var{val}] [@b{-f}] [@b{-g}] [@b{--gstabs}]
+ [@b{--gstabs+}] [@b{--gdwarf-2}] [@b{--help}] [@b{-I} @var{dir}] [@b{-J}]
+ [@b{-K}] [@b{-L}] [@b{--listing-lhs-width}=@var{NUM}]
+ [@b{--listing-lhs-width2}=@var{NUM}] [@b{--listing-rhs-width}=@var{NUM}]
+ [@b{--listing-cont-lines}=@var{NUM}] [@b{--keep-locals}] [@b{-o}
+ @var{objfile}] [@b{-R}] [@b{--reduce-memory-overheads}] [@b{--statistics}]
+ [@b{-v}] [@b{-version}] [@b{--version}] [@b{-W}] [@b{--warn}]
+ [@b{--fatal-warnings}] [@b{-w}] [@b{-x}] [@b{-Z}] [@b{@@@var{FILE}}]
+ [@b{--target-help}] [@var{target-options}]
[@b{--}|@var{files} @dots{}]
@c
@c Target dependent options are listed below. Keep the list sorted.
@c Add an empty line for separation.
-@ifset A29K
-@c am29k has no machine-dependent assembler options
-@end ifset
@ifset ALPHA
@emph{Target Alpha options:}
[@b{-O}|@b{-n}|@b{-N}]
@end ifset
@ifset H8
-@c Renesas family chips have no machine-dependent assembler options
+
+@emph{Target H8/300 options:}
+ [-h-tick-hex]
@end ifset
@ifset HPPA
@c HPPA has no machine-dependent assembler options (yet).
@emph{Target i386 options:}
[@b{--32}|@b{--64}] [@b{-n}]
+ [@b{-march}=@var{CPU}[+@var{EXTENSION}@dots{}]] [@b{-mtune}=@var{CPU}]
@end ifset
@ifset I960
[@b{-mconstant-gp}|@b{-mauto-pic}]
[@b{-milp32}|@b{-milp64}|@b{-mlp64}|@b{-mp64}]
[@b{-mle}|@b{mbe}]
+ [@b{-mtune=itanium1}|@b{-mtune=itanium2}]
+ [@b{-munwind-check=warning}|@b{-munwind-check=error}]
+ [@b{-mhint.b=ok}|@b{-mhint.b=warning}|@b{-mhint.b=error}]
[@b{-x}|@b{-xexplicit}] [@b{-xauto}] [@b{-xdebug}]
@end ifset
@ifset IP2K
@emph{Target IP2K options:}
[@b{-mip2022}|@b{-mip2022ext}]
@end ifset
+@ifset M32C
+
+@emph{Target M32C options:}
+ [@b{-m32c}|@b{-m16c}] [-relax] [-h-tick-hex]
+@end ifset
@ifset M32R
@emph{Target M32R options:}
[@b{-m68hc11}|@b{-m68hc12}|@b{-m68hcs12}]
[@b{-mshort}|@b{-mlong}]
[@b{-mshort-double}|@b{-mlong-double}]
- [@b{--force-long-branchs}] [@b{--short-branchs}]
+ [@b{--force-long-branches}] [@b{--short-branches}]
[@b{--strict-direct-mode}] [@b{--print-insn-syntax}]
[@b{--print-opcodes}] [@b{--generate-example}]
@end ifset
@emph{Target MIPS options:}
[@b{-nocpp}] [@b{-EL}] [@b{-EB}] [@b{-O}[@var{optimization level}]]
[@b{-g}[@var{debug level}]] [@b{-G} @var{num}] [@b{-KPIC}] [@b{-call_shared}]
- [@b{-non_shared}] [@b{-xgot}]
+ [@b{-non_shared}] [@b{-xgot} [@b{-mvxworks-pic}]
[@b{-mabi}=@var{ABI}] [@b{-32}] [@b{-n32}] [@b{-64}] [@b{-mfp32}] [@b{-mgp32}]
[@b{-march}=@var{CPU}] [@b{-mtune}=@var{CPU}] [@b{-mips1}] [@b{-mips2}]
[@b{-mips3}] [@b{-mips4}] [@b{-mips5}] [@b{-mips32}] [@b{-mips32r2}]
[@b{-trap}] [@b{-no-break}] [@b{-break}] [@b{-no-trap}]
[@b{-mfix7000}] [@b{-mno-fix7000}]
[@b{-mips16}] [@b{-no-mips16}]
+ [@b{-msmartmips}] [@b{-mno-smartmips}]
[@b{-mips3d}] [@b{-no-mips3d}]
[@b{-mdmx}] [@b{-no-mdmx}]
+ [@b{-mdsp}] [@b{-mno-dsp}]
+ [@b{-mdspr2}] [@b{-mno-dspr2}]
+ [@b{-mmt}] [@b{-mno-mt}]
[@b{-mdebug}] [@b{-no-mdebug}]
[@b{-mpdr}] [@b{-mno-pdr}]
@end ifset
@emph{Target PowerPC options:}
[@b{-mpwrx}|@b{-mpwr2}|@b{-mpwr}|@b{-m601}|@b{-mppc}|@b{-mppc32}|@b{-m603}|@b{-m604}|
- @b{-m403}|@b{-m405}|@b{-mppc64}|@b{-m620}|@b{-mppc64bridge}|@b{-mbooke}|
- @b{-mbooke32}|@b{-mbooke64}]
- [@b{-mcom}|@b{-many}|@b{-maltivec}] [@b{-memb}]
+ @b{-m403}|@b{-m405}|@b{-mppc64}|@b{-m620}|@b{-mppc64bridge}|@b{-mbooke}]
+ [@b{-mcom}|@b{-many}|@b{-maltivec}|@b{-mvsx}] [@b{-memb}]
[@b{-mregnames}|@b{-mno-regnames}]
[@b{-mrelocatable}|@b{-mrelocatable-lib}]
[@b{-mlittle}|@b{-mlittle-endian}|@b{-mbig}|@b{-mbig-endian}]
[@b{-mcpu=54[123589]}|@b{-mcpu=54[56]lp}] [@b{-mfar-mode}|@b{-mf}]
[@b{-merrors-to-file} @var{<filename>}|@b{-me} @var{<filename>}]
@end ifset
+
+@ifset Z80
+
+@emph{Target Z80 options:}
+ [@b{-z80}] [@b{-r800}]
+ [@b{ -ignore-undocumented-instructions}] [@b{-Wnud}]
+ [@b{ -ignore-unportable-instructions}] [@b{-Wnup}]
+ [@b{ -warn-undocumented-instructions}] [@b{-Wud}]
+ [@b{ -warn-unportable-instructions}] [@b{-Wup}]
+ [@b{ -forbid-undocumented-instructions}] [@b{-Fud}]
+ [@b{ -forbid-unportable-instructions}] [@b{-Fup}]
+@end ifset
+
@ifset Z8000
@c Z8000 has no machine-dependent assembler options
@end ifset
@c man begin OPTIONS
@table @gcctabopt
-@item -a[cdhlmns]
+@include at-file.texi
+
+@item -a[cdghlmns]
Turn on listings, in any of a variety of ways:
@table @gcctabopt
@item -ad
omit debugging directives
+@item -ag
+include general information, like @value{AS} version and options passed
+
@item -ah
include high-level source
the last one. By itself, @samp{-a} defaults to @samp{-ahls}.
@item --alternate
-Begin in alternate macro mode, see @ref{Altmacro,,@code{.altmacro}}.
+Begin in alternate macro mode.
+@ifclear man
+@xref{Altmacro,,@code{.altmacro}}.
+@end ifclear
@item -D
Ignored. This option is accepted for script compatibility with calls to
other assemblers.
+@item --debug-prefix-map @var{old}=@var{new}
+When assembling files in directory @file{@var{old}}, record debugging
+information describing them as in @file{@var{new}} instead.
+
@item --defsym @var{sym}=@var{value}
Define the symbol @var{sym} to be @var{value} before assembling the input file.
@var{value} must be an integer constant. As in C, a leading @samp{0x}
-indicates a hexadecimal value, and a leading @samp{0} indicates an octal value.
+indicates a hexadecimal value, and a leading @samp{0} indicates an octal
+value. The value of the symbol can be overridden inside a source file via the
+use of a @code{.set} pseudo-op.
@item -f
``fast''---skip whitespace and comment preprocessing (assume source is
@item -L
@itemx --keep-locals
-Keep (in the symbol table) local symbols. On traditional a.out systems
-these start with @samp{L}, but different systems have different local
-label prefixes.
+Keep (in the symbol table) local symbols. These symbols start with
+system-specific local label prefixes, typically @samp{.L} for ELF systems
+or @samp{L} for traditional a.out systems.
+@ifclear man
+@xref{Symbol Names}.
+@end ifclear
@item --listing-lhs-width=@var{number}
Set the maximum width, in words, of the output data column for an assembler
@item -R
Fold the data section into the text section.
+@kindex --hash-size=@var{number}
+Set the default size of GAS's hash tables to a prime number close to
+@var{number}. Increasing this value can reduce the length of time it takes the
+assembler to perform its tasks, at the expense of increasing the assembler's
+memory requirements. Similarly reducing this value can reduce the memory
+requirements at the expense of speed.
+
+@item --reduce-memory-overheads
+This option reduces GAS's memory requirements, at the expense of making the
+assembly processes slower. Currently this switch is a synonym for
+@samp{--hash-size=4051}, but in the future it may have other effects as well.
+
@item --statistics
Print the maximum space (in bytes) and total time (in seconds) used by
assembly.
@end table
@end ifset
+@ifset M32C
+The following options are available when @value{AS} is configured for the
+Renesas M32C and M16C processors.
+
+@table @gcctabopt
+
+@item -m32c
+Assemble M32C instructions.
+
+@item -m16c
+Assemble M16C instructions (the default).
+
+@item -relax
+Enable support for link-time relaxations.
+
+@item -h-tick-hex
+Support H'00 style hex constants in addition to 0x00 style.
+
+@end table
+@end ifset
+
@ifset M32R
The following options are available when @value{AS} is configured for the
Renesas M32R (formerly Mitsubishi M32R) series.
@item -mlong-double
Specify to use the 64-bit double ABI.
-@item --force-long-branchs
+@item --force-long-branches
Relative branches are turned into absolute ones. This concerns
conditional branches, unconditional branches and branches to a
sub routine.
-@item -S | --short-branchs
-Do not turn relative branchs into absolute ones
+@item -S | --short-branches
+Do not turn relative branches into absolute ones
when the offset is out of range.
@item --strict-direct-mode
@code{.set mips16} at the start of the assembly file. @samp{-no-mips16}
turns off this option.
+@item -msmartmips
+@itemx -mno-smartmips
+Enables the SmartMIPS extension to the MIPS32 instruction set. This is
+equivalent to putting @code{.set smartmips} at the start of the assembly file.
+@samp{-mno-smartmips} turns off this option.
+
@item -mips3d
@itemx -no-mips3d
Generate code for the MIPS-3D Application Specific Extension.
This tells the assembler to accept MDMX instructions.
@samp{-no-mdmx} turns off this option.
+@item -mdsp
+@itemx -mno-dsp
+Generate code for the DSP Release 1 Application Specific Extension.
+This tells the assembler to accept DSP Release 1 instructions.
+@samp{-mno-dsp} turns off this option.
+
+@item -mdspr2
+@itemx -mno-dspr2
+Generate code for the DSP Release 2 Application Specific Extension.
+This option implies -mdsp.
+This tells the assembler to accept DSP Release 2 instructions.
+@samp{-mno-dspr2} turns off this option.
+
+@item -mmt
+@itemx -mno-mt
+Generate code for the MT Application Specific Extension.
+This tells the assembler to accept MT instructions.
+@samp{-mno-mt} turns off this option.
+
@item --construct-floats
@itemx --no-construct-floats
The @samp{--no-construct-floats} option disables the construction of
The default is @option{--transform};
@option{--no-transform} should be used only in the rare cases when the
instructions must be exactly as specified in the assembly source.
+
+@item --rename-section @var{oldname}=@var{newname}
+When generating output sections, rename the @var{oldname} section to
+@var{newname}.
+@end table
+@end ifset
+
+@ifset Z80
+The following options are available when @value{AS} is configured for
+a Z80 family processor.
+@table @gcctabopt
+@item -z80
+Assemble for Z80 processor.
+@item -r800
+Assemble for R800 processor.
+@item -ignore-undocumented-instructions
+@itemx -Wnud
+Assemble undocumented Z80 instructions that also work on R800 without warning.
+@item -ignore-unportable-instructions
+@itemx -Wnup
+Assemble all undocumented Z80 instructions without warning.
+@item -warn-undocumented-instructions
+@itemx -Wud
+Issue a warning for undocumented Z80 instructions that also work on R800.
+@item -warn-unportable-instructions
+@itemx -Wup
+Issue a warning for undocumented Z80 instructions that do not work on R800.
+@item -forbid-undocumented-instructions
+@itemx -Fud
+Treat all undocumented instructions as errors.
+@item -forbid-unportable-instructions
+@itemx -Fup
+Treat undocumented Z80 instructions that do not work on R800 as errors.
@end table
@end ifset
Series Programming Manual}. For the H8/300H, see @cite{H8/300H Series
Programming Manual} (Renesas).
@end ifset
-@ifset H8/500
-For information on the H8/500 machine instruction set, see @cite{H8/500
-Series Programming Manual} (Renesas M21T001).
-@end ifset
@ifset SH
For information on the Renesas (formerly Hitachi) / SuperH SH machine instruction set,
see @cite{SH-Microcomputer User's Manual} (Renesas) or
@value{OBJ-NAME} format object files.
@end ifclear
@c The following should exhaust all configs that set MULTI-OBJ, ideally
-@ifset A29K
-On the @value{TARGET}, @command{@value{AS}} can be configured to produce either
-@code{a.out} or COFF format object files.
-@end ifset
@ifset I960
On the @value{TARGET}, @command{@value{AS}} can be configured to produce either
@code{b.out} or COFF format object files.
@ifset GENERIC
(@pxref{Line,,@code{.line}})
@end ifset
-@ifclear GENERIC
-@ifclear A29K
-(@pxref{Line,,@code{.line}})
-@end ifclear
-@ifset A29K
-(@pxref{Ln,,@code{.ln}})
-@end ifset
-@end ifclear
then it is used to calculate the number printed,
otherwise the actual line in the current source file is printed. The
message text is intended to be self explanatory (in the grand Unix
@cindex options, all versions of assembler
This chapter describes command-line options available in @emph{all}
-versions of the @sc{gnu} assembler; @pxref{Machine Dependencies}, for options specific
+versions of the @sc{gnu} assembler; see @ref{Machine Dependencies},
+for options specific
@ifclear GENERIC
to the @value{TARGET} target.
@end ifclear
@c man end
@menu
-* a:: -a[cdhlns] enable listings
+* a:: -a[cdghlns] enable listings
* alternate:: --alternate enable alternate macro syntax
* D:: -D for compatibility
* f:: -f to work faster
* K:: -K for difference tables
@end ifset
-* L:: -L to retain local labels
+* L:: -L to retain local symbols
* listing:: --listing-XXX to configure listing output
* M:: -M or --mri to assemble in MRI compatibility mode
* MD:: --MD for dependency tracking
@end menu
@node a
-@section Enable Listings: @option{-a[cdhlns]}
+@section Enable Listings: @option{-a[cdghlns]}
@kindex -a
@kindex -ac
@kindex -ad
+@kindex -ag
@kindex -ah
@kindex -al
@kindex -an
@samp{-g} be used, and that assembly listings (@samp{-al}) be requested
also.
+Use the @samp{-ag} option to print a first section with general assembly
+information, like @value{AS} version, switches passed, or time stamp.
+
Use the @samp{-ac} option to omit false conditionals from a listing. Any lines
which are not assembled because of a false @code{.if} (or @code{.ifdef}, or any
other conditional), or a true @code{.if} followed by an @code{.else}, will be
The letters after @samp{-a} may be combined into one option,
@emph{e.g.}, @samp{-aln}.
-Note if the assembler source is coming from the standard input (eg because it
+Note if the assembler source is coming from the standard input (e.g.,
+because it
is being created by @code{@value{GCC}} and the @samp{-pipe} command line switch
is being used) then the listing will not contain any comments or preprocessor
directives. This is because the listing code buffers input source lines from
@ifset DIFF-TBL-KLUGE
@cindex difference tables, warning
@cindex warning for altered difference tables
-@command{@value{AS}} sometimes alters the code emitted for directives of the form
-@samp{.word @var{sym1}-@var{sym2}}; @pxref{Word,,@code{.word}}.
+@command{@value{AS}} sometimes alters the code emitted for directives of the
+form @samp{.word @var{sym1}-@var{sym2}}. @xref{Word,,@code{.word}}.
You can use the @samp{-K} option if you want a warning issued when this
is done.
@end ifset
@node L
-@section Include Local Labels: @option{-L}
+@section Include Local Symbols: @option{-L}
@kindex -L
-@cindex local labels, retaining in output
-Labels beginning with @samp{L} (upper case only) are called @dfn{local
-labels}. @xref{Symbol Names}. Normally you do not see such labels when
-debugging, because they are intended for the use of programs (like
-compilers) that compose assembler programs, not for your notice.
-Normally both @command{@value{AS}} and @code{@value{LD}} discard such labels, so you do not
-normally debug with them.
-
-This option tells @command{@value{AS}} to retain those @samp{L@dots{}} symbols
+@cindex local symbols, retaining in output
+Symbols beginning with system-specific local label prefixes, typically
+@samp{.L} for ELF systems or @samp{L} for traditional a.out systems, are
+called @dfn{local symbols}. @xref{Symbol Names}. Normally you do not see
+such symbols when debugging, because they are intended for the use of
+programs (like compilers) that compose assembler programs, not for your
+notice. Normally both @command{@value{AS}} and @code{@value{LD}} discard
+such symbols, so you do not normally debug with them.
+
+This option tells @command{@value{AS}} to retain those local symbols
in the object file. Usually if you do this you also tell the linker
-@code{@value{LD}} to preserve symbols whose names begin with @samp{L}.
-
-By default, a local label is any label beginning with @samp{L}, but each
-target is allowed to redefine the local label prefix.
-@ifset HPPA
-On the HPPA local labels begin with @samp{L$}.
-@end ifset
+@code{@value{LD}} to preserve those symbols.
@node listing
@section Configuring listing output: @option{--listing}
The listing feature of the assembler can be enabled via the command line switch
@samp{-a} (@pxref{a}). This feature combines the input source file(s) with a
hex dump of the corresponding locations in the output object file, and displays
-them as a listing file. The format of this listing can be controlled by pseudo
-ops inside the assembler source (@pxref{List} @pxref{Title} @pxref{Sbttl}
-@pxref{Psize} @pxref{Eject}) and also by the following switches:
+them as a listing file. The format of this listing can be controlled by
+directives inside the assembler source (i.e., @code{.list} (@pxref{List}),
+@code{.title} (@pxref{Title}), @code{.sbttl} (@pxref{Sbttl}),
+@code{.psize} (@pxref{Psize}), and
+@code{.eject} (@pxref{Eject}) and also by the following switches:
@table @gcctabopt
@item --listing-lhs-width=@samp{number}
do include file processing with the @code{.include} directive
(@pxref{Include,,@code{.include}}). You can use the @sc{gnu} C compiler driver
to get other ``CPP'' style preprocessing by giving the input file a
-@samp{.S} suffix. @xref{Overall Options,, Options Controlling the Kind of
+@samp{.S} suffix. @xref{Overall Options, ,Options Controlling the Kind of
Output, gcc.info, Using GNU CC}.
Excess whitespace, comments, and character constants
@cindex line comment character
Anything from the @dfn{line comment} character to the next newline
is considered a comment and is ignored. The line comment character is
-@ifset A29K
-@samp{;} for the AMD 29K family;
-@end ifset
@ifset ARC
@samp{;} on the ARC;
@end ifset
@ifset H8/300
@samp{;} for the H8/300 family;
@end ifset
-@ifset H8/500
-@samp{!} for the H8/500 family;
-@end ifset
@ifset HPPA
@samp{;} for the HPPA;
@end ifset
@ifset IP2K
@samp{#} on the ip2k;
@end ifset
+@ifset M32C
+@samp{#} on the m32c;
+@end ifset
@ifset M32R
@samp{#} on the m32r;
@end ifset
@ifset M68HC11
@samp{#} on the 68HC11 and 68HC12;
@end ifset
-@ifset M880X0
-@samp{;} on the M880x0;
-@end ifset
@ifset VAX
@samp{#} on the Vax;
@end ifset
+@ifset Z80
+@samp{;} for the Z80;
+@end ifset
@ifset Z8000
@samp{!} for the Z8000;
@end ifset
To be compatible with past assemblers, lines that begin with @samp{#} have a
special interpretation. Following the @samp{#} should be an absolute
expression (@pxref{Expressions}): the logical line number of the @emph{next}
-line. Then a string (@pxref{Strings,, Strings}) is allowed: if present it is a
+line. Then a string (@pxref{Strings, ,Strings}) is allowed: if present it is a
new logical file name. The rest of the line, if any, should be whitespace.
If the first non-whitespace characters on the line are not numeric,
constants are an exception: they do not end statements.
@end ifclear
@ifset abnormal-separator
-@ifset A29K
-A @dfn{statement} ends at a newline character (@samp{\n}) or an ``at''
-sign (@samp{@@}). The newline or at sign is considered part of the
-preceding statement. Newlines and at signs within character constants
-are an exception: they do not end statements.
-@end ifset
@ifset HPPA
A @dfn{statement} ends at a newline character (@samp{\n}) or an exclamation
point (@samp{!}). The newline or exclamation point is considered part of the
@end ifset
@ifset H8
A @dfn{statement} ends at a newline character (@samp{\n}); or (for the
-H8/300) a dollar sign (@samp{$}); or (for the
-Renesas-SH or the
-H8/500) a semicolon
+H8/300) a dollar sign (@samp{$}); or (for the Renesas-SH) a semicolon
(@samp{;}). The newline or separator character is considered part of
the preceding statement. Newlines and separators within character
constants are an exception: they do not end statements.
@end ifclear
@ifset GENERIC
A @dfn{statement} ends at a newline character (@samp{\n}) or line
-separator character. (The line separator is usually @samp{;}, unless
-this conflicts with the comment character; @pxref{Machine Dependencies}.) The
+separator character. (The line separator is usually @samp{;}, unless this
+conflicts with the comment character; see @ref{Machine Dependencies}.) The
newline or separator character is considered part of the preceding
statement. Newlines and separators within character constants are an
exception: they do not end statements.
(or semicolon @samp{;})
@end ifclear
@ifset abnormal-separator
-@ifset A29K
-(or at sign @samp{@@})
-@end ifset
@ifset H8
(or dollar sign @samp{$}, for the H8/300; or semicolon @samp{;} for the
-Renesas SH or H8/500)
+Renesas SH)
@end ifset
@end ifset
@end ifclear
4.2 assembler seems to allow any of @samp{defghDEFGH}.)
@end ignore
-On the H8/300, H8/500,
-Renesas / SuperH SH,
+On the H8/300, Renesas / SuperH SH,
and AMD 29K architectures, the letter must be
one of the letters @samp{DFPRSX} (in upper or lower case).
On the HPPA architecture, the letter must be @samp{E} (upper case only).
@end ifset
@ifclear GENERIC
-@ifset A29K
-One of the letters @samp{DFPRSX} (in upper or lower case).
-@end ifset
@ifset ARC
One of the letters @samp{DFRS} (in upper or lower case).
@end ifset
@cindex bit fields
@cindex constants, bit field
You can also define numeric constants as @dfn{bit fields}.
-specify two numbers separated by a colon---
+Specify two numbers separated by a colon---
@example
@var{mask}:@var{value}
@end example
the task of adjusting mentions of object-file addresses so they refer to
the proper run-time addresses.
@ifset H8
-For the H8/300 and H8/500,
-and for the Renesas / SuperH SH,
+For the H8/300, and for the Renesas / SuperH SH,
@command{@value{AS}} pads sections if needed to
ensure they end on a word (sixteen bit) boundary.
@end ifset
@end ifset
@ifclear GENERIC
@ifset H8
-On the H8/300 and H8/500 platforms, each subsection is zero-padded to a word
+On the H8/300 platform, each subsection is zero-padded to a word
boundary (two bytes).
The same is true on the Renesas SH.
@end ifset
@c these paragraphs might need to vanish from this manual, and be
@c discussed in BFD chapter of binutils (or some such).
@end ifset
-@ifset A29K
-On the AMD 29K family, no particular padding is added to section or
-subsection sizes; @value{AS} forces no alignment on this platform.
-@end ifset
@end ifclear
Subsections appear in your object file in numeric order, lowest numbered
can also use the @code{.subsection} directive (@pxref{SubSection})
to specify a subsection: @samp{.subsection @var{expression}}.
@end ifset
-@var{Expression} should be an absolute expression.
-(@xref{Expressions}.) If you just say @samp{.text} then @samp{.text 0}
+@var{Expression} should be an absolute expression
+(@pxref{Expressions}). If you just say @samp{.text} then @samp{.text 0}
is assumed. Likewise @samp{.data} means @samp{.data 0}. Assembly
begins in @code{text 0}. For instance:
@smallexample
@ref{Lcomm,,@code{.lcomm}}.
The @code{.comm} pseudo-op may be used to declare a common symbol, which is
-another form of uninitialized symbol; see @xref{Comm,,@code{.comm}}.
+another form of uninitialized symbol; see @ref{Comm,,@code{.comm}}.
@ifset GENERIC
When assembling for a target which supports multiple sections, such as ELF or
A symbol can be given an arbitrary value by writing a symbol, followed
by an equals sign @samp{=}, followed by an expression
(@pxref{Expressions}). This is equivalent to using the @code{.set}
-directive. @xref{Set,,@code{.set}}.
+directive. @xref{Set,,@code{.set}}. In the same way, using a double
+equals sign @samp{=}@samp{=} here represents an equivalent of the
+@code{.eqv} directive. @xref{Eqv,,@code{.eqv}}.
@node Symbol Names
@section Symbol Names
Symbol names begin with a letter or with one of @samp{._}. On most
machines, you can also use @code{$} in symbol names; exceptions are
noted in @ref{Machine Dependencies}. That character may be followed by any
-string of digits, letters, dollar signs (unless otherwise noted in
-@ref{Machine Dependencies}), and underscores.
+string of digits, letters, dollar signs (unless otherwise noted for a
+particular target machine), and underscores.
@end ifclear
-@ifset A29K
-For the AMD 29K family, @samp{?} is also allowed in the
-body of a symbol name, though not at its beginning.
-@end ifset
-
@ifset SPECIAL-SYMS
@ifset H8
Symbol names begin with a letter or with one of @samp{._}. On the
-Renesas SH or the H8/500, you can also use @code{$} in symbol names. That
+Renesas SH you can also use @code{$} in symbol names. That
character may be followed by any string of digits, letters, dollar signs (save
on the H8/300), and underscores.
@end ifset
@cindex local symbol names
@cindex symbol names, local
+A local symbol is any symbol beginning with certain local label prefixes.
+By default, the local label prefix is @samp{.L} for ELF systems or
+@samp{L} for traditional a.out systems, but each target may have its own
+set of local label prefixes.
+@ifset HPPA
+On the HPPA local symbols begin with @samp{L$}.
+@end ifset
+
+Local symbols are defined and used within the assembler, but they are
+normally not saved in object files. Thus, they are not visible when debugging.
+You may use the @samp{-L} option (@pxref{L, ,Include Local Symbols:
+@option{-L}}) to retain the local symbols in the object files.
+
+@subheading Local Labels
+
+@cindex local labels
@cindex temporary symbol names
@cindex symbol names, temporary
-Local symbols help compilers and programmers use names temporarily.
+Local labels help compilers and programmers use names temporarily.
They create symbols which are guaranteed to be unique over the entire scope of
the input source code and which can be referred to by a simple notation.
-To define a local symbol, write a label of the form @samp{@b{N}:} (where @b{N}
+To define a local label, write a label of the form @samp{@b{N}:} (where @b{N}
represents any positive integer). To refer to the most recent previous
-definition of that symbol write @samp{@b{N}b}, using the same number as when
+definition of that label write @samp{@b{N}b}, using the same number as when
you defined the label. To refer to the next definition of a local label, write
-@samp{@b{N}f}--- The @samp{b} stands for``backwards'' and the @samp{f} stands
+@samp{@b{N}f}---the @samp{b} stands for ``backwards'' and the @samp{f} stands
for ``forwards''.
There is no restriction on how you can use these labels, and you can reuse them
label_4: branch label_3
@end smallexample
-Local symbol names are only a notational device. They are immediately
+Local label names are only a notational device. They are immediately
transformed into more conventional symbol names before the assembler uses them.
-The symbol names stored in the symbol table, appearing in error messages and
-optionally emitted to the object file. The names are constructed using these
-parts:
+The symbol names are stored in the symbol table, appear in error messages, and
+are optionally emitted to the object file. The names are constructed using
+these parts:
@table @code
-@item L
-All local labels begin with @samp{L}. Normally both @command{@value{AS}} and
-@code{@value{LD}} forget symbols that start with @samp{L}. These labels are
+@item @emph{local label prefix}
+All local symbols begin with the system-specific local label prefix.
+Normally both @command{@value{AS}} and @code{@value{LD}} forget symbols
+that start with the local label prefix. These labels are
used for symbols you are never intended to see. If you use the
@samp{-L} option then @command{@value{AS}} retains these symbols in the
object file. If you also instruct @code{@value{LD}} to retain these symbols,
This is a serial number to keep the labels distinct. The first definition of
@samp{0:} gets the number @samp{1}. The 15th definition of @samp{0:} gets the
number @samp{15}, and so on. Likewise the first definition of @samp{1:} gets
-the number @samp{1} and its 15th defintion gets @samp{15} as well.
+the number @samp{1} and its 15th definition gets @samp{15} as well.
@end table
-So for example, the first @code{1:} is named @code{L1@kbd{C-B}1}, the 44th
-@code{3:} is named @code{L3@kbd{C-B}44}.
+So for example, the first @code{1:} may be named @code{.L1@kbd{C-B}1}, and
+the 44th @code{3:} may be named @code{.L3@kbd{C-B}44}.
@subheading Dollar Local Labels
@cindex dollar local symbols
@code{@value{AS}} also supports an even more local form of local labels called
-dollar labels. These labels go out of scope (ie they become undefined) as soon
-as a non-local label is defined. Thus they remain valid for only a small
+dollar labels. These labels go out of scope (i.e., they become undefined) as
+soon as a non-local label is defined. Thus they remain valid for only a small
region of the input source code. Normal local labels, by contrast, remain in
scope for the entire file, or until they are redefined by another occurrence of
the same local label.
Dollar labels are defined in exactly the same way as ordinary local labels,
-except that instead of being terminated by a colon, they are terminated by a
-dollar sign. eg @samp{@b{55$}}.
+except that they have a dollar sign suffix to their numeric value, e.g.,
+@samp{@b{55$:}}.
They can also be distinguished from ordinary local labels by their transformed
-name which uses ASCII character @samp{\001} (control-A) as the magic character
-to distinguish them from ordinary labels. Thus the 5th defintion of @samp{6$}
-is named @samp{L6@kbd{C-A}5}.
+names which use ASCII character @samp{\001} (control-A) as the magic character
+to distinguish them from ordinary labels. For example, the fifth definition of
+@samp{6$} may be named @samp{.L6@kbd{C-A}5}.
@node Dot
@section The Special Dot Symbol
@command{@value{AS}} is assembling into. Thus, the expression @samp{melvin:
.long .} defines @code{melvin} to contain its own address.
Assigning a value to @code{.} is treated the same as a @code{.org}
-directive. Thus, the expression @samp{.=.+4} is the same as saying
+directive.
@ifclear no-space-dir
+Thus, the expression @samp{.=.+4} is the same as saying
@samp{.space 4}.
@end ifclear
-@ifset no-space-dir
-@ifset A29K
-@samp{.block 4}.
-@end ifset
-@end ifset
@node Symbol Attributes
@section Symbol Attributes
@item %
@dfn{Remainder}.
-@item <
-@itemx <<
+@item <<
@dfn{Shift Left}. Same as the C operator @samp{<<}.
-@item >
-@itemx >>
+@item >>
@dfn{Shift Right}. Same as the C operator @samp{>>}.
@end table
@item ==
@dfn{Is Equal To}
@item <>
+@itemx !=
@dfn{Is Not Equal To}
@item <
@dfn{Is Less Than}
-@itemx >
+@item >
@dfn{Is Greater Than}
-@itemx >=
+@item >=
@dfn{Is Greater Than Or Equal To}
-@itemx <=
+@item <=
@dfn{Is Less Than Or Equal To}
The comparison operators can be used as infix operators. A true results has a
@end ifset
@ifclear GENERIC
@ifset machine-directives
-@xref{Machine Dependencies} for additional directives.
+@xref{Machine Dependencies}, for additional directives.
@end ifset
@end ifclear
@menu
* Abort:: @code{.abort}
@ifset COFF
-* ABORT:: @code{.ABORT}
+* ABORT (COFF):: @code{.ABORT}
@end ifset
* Align:: @code{.align @var{abs-expr} , @var{abs-expr}}
* Asciz:: @code{.asciz "@var{string}"}@dots{}
* Balign:: @code{.balign @var{abs-expr} , @var{abs-expr}}
* Byte:: @code{.byte @var{expressions}}
+* CFI directives:: @code{.cfi_startproc [simple]}, @code{.cfi_endproc}, etc.
* Comm:: @code{.comm @var{symbol} , @var{length} }
-
-* CFI directives:: @code{.cfi_startproc}, @code{.cfi_endproc}, etc.
-
* Data:: @code{.data @var{subsection}}
@ifset COFF
* Def:: @code{.def @var{name}}
* Endif:: @code{.endif}
* Equ:: @code{.equ @var{symbol}, @var{expression}}
* Equiv:: @code{.equiv @var{symbol}, @var{expression}}
+* Eqv:: @code{.eqv @var{symbol}, @var{expression}}
* Err:: @code{.err}
* Error:: @code{.error @var{string}}
* Exitm:: @code{.exitm}
* Extern:: @code{.extern}
* Fail:: @code{.fail}
-@ifclear no-file-dir
-* File:: @code{.file @var{string}}
-@end ifclear
-
+* File:: @code{.file}
* Fill:: @code{.fill @var{repeat} , @var{size} , @var{value}}
* Float:: @code{.float @var{flonums}}
* Func:: @code{.func}
* Global:: @code{.global @var{symbol}}, @code{.globl @var{symbol}}
@ifset ELF
+* Gnu_attribute:: @code{.gnu_attribute @var{tag},@var{value}}
* Hidden:: @code{.hidden @var{names}}
@end ifset
* Line:: @code{.line @var{line-number}}
@end ifclear
-* Ln:: @code{.ln @var{line-number}}
* Linkonce:: @code{.linkonce [@var{type}]}
* List:: @code{.list}
+* Ln:: @code{.ln @var{line-number}}
+* Loc:: @code{.loc @var{fileno} @var{lineno}}
+* Loc_mark_labels:: @code{.loc_mark_labels @var{enable}}
+@ifset ELF
+* Local:: @code{.local @var{names}}
+@end ifset
+
* Long:: @code{.long @var{expressions}}
@ignore
* Lsym:: @code{.lsym @var{symbol}, @var{expression}}
* Noaltmacro:: @code{.noaltmacro}
* Nolist:: @code{.nolist}
* Octa:: @code{.octa @var{bignums}}
-* Org:: @code{.org @var{new-lc} , @var{fill}}
-* P2align:: @code{.p2align @var{abs-expr} , @var{abs-expr}}
+* Org:: @code{.org @var{new-lc}, @var{fill}}
+* P2align:: @code{.p2align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}}
@ifset ELF
* PopSection:: @code{.popsection}
* Previous:: @code{.previous}
@end ifset
* Quad:: @code{.quad @var{bignums}}
+* Reloc:: @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]}
* Rept:: @code{.rept @var{count}}
* Sbttl:: @code{.sbttl "@var{subheading}"}
@ifset COFF
* Scl:: @code{.scl @var{class}}
@end ifset
@ifset COFF-ELF
-* Section:: @code{.section @var{name}}
+* Section:: @code{.section @var{name}[, @var{flags}]}
@end ifset
* Set:: @code{.set @var{symbol}, @var{expression}}
@ifset COFF-ELF
* Size:: @code{.size [@var{name} , @var{expression}]}
@end ifset
-
+@ifclear no-space-dir
* Skip:: @code{.skip @var{size} , @var{fill}}
+@end ifclear
+
* Sleb128:: @code{.sleb128 @var{expressions}}
+@ifclear no-space-dir
* Space:: @code{.space @var{size} , @var{fill}}
+@end ifclear
@ifset have-stabs
* Stab:: @code{.stabd, .stabn, .stabs}
@end ifset
-* String:: @code{.string "@var{str}"}
+* String:: @code{.string "@var{str}"}, @code{.string8 "@var{str}"}, @code{.string16 "@var{str}"}, @code{.string32 "@var{str}"}, @code{.string64 "@var{str}"}
* Struct:: @code{.struct @var{expression}}
@ifset ELF
* SubSection:: @code{.subsection}
* Warning:: @code{.warning @var{string}}
* Weak:: @code{.weak @var{names}}
+* Weakref:: @code{.weakref @var{alias}, @var{symbol}}
* Word:: @code{.word @var{expressions}}
* Deprecated:: Deprecated Directives
@end menu
quit also. One day @code{.abort} will not be supported.
@ifset COFF
-@node ABORT
-@section @code{.ABORT}
+@node ABORT (COFF)
+@section @code{.ABORT} (COFF)
@cindex @code{ABORT} directive
When producing COFF output, @command{@value{AS}} accepts this directive as a
with no-op instructions when appropriate.
The way the required alignment is specified varies from system to system.
-For the a29k, arc, hppa, i386 using ELF, i860, iq2000, m68k, m88k, or32,
+For the arc, hppa, i386 using ELF, i860, iq2000, m68k, or32,
s390, sparc, tic4x, tic80 and xtensa, the first expression is the
alignment request in bytes. For example @samp{.align 8} advances
the location counter until it is a multiple of 8. If the location counter
is already a multiple of 8, no change is needed. For the tic54x, the
first expression is the alignment request in words.
-For other systems, including the i386 using a.out format, and the arm and
+For other systems, including ppc, i386 using a.out format, arm and
strongarm, it is the
number of low-order zero bits the location counter must have after
advancement. For example @samp{.align 3} advances the location
described later, which have a consistent behavior across all
architectures (but are specific to GAS).
+@node Altmacro
+@section @code{.altmacro}
+Enable alternate macro mode, enabling:
+
+@ftable @code
+@item LOCAL @var{name} [ , @dots{} ]
+One additional directive, @code{LOCAL}, is available. It is used to
+generate a string replacement for each of the @var{name} arguments, and
+replace any instances of @var{name} in each macro expansion. The
+replacement string is unique in the assembly, and different for each
+separate macro expansion. @code{LOCAL} allows you to write macros that
+define symbols, without fear of conflict between separate macro expansions.
+
+@item String delimiters
+You can write strings delimited in these other ways besides
+@code{"@var{string}"}:
+
+@table @code
+@item '@var{string}'
+You can delimit strings with single-quote characters.
+
+@item <@var{string}>
+You can delimit strings with matching angle brackets.
+@end table
+
+@item single-character string escape
+To include any single character literally in a string (even if the
+character would otherwise have some special meaning), you can prefix the
+character with @samp{!} (an exclamation mark). For example, you can
+write @samp{<4.3 !> 5.4!!>} to get the literal text @samp{4.3 > 5.4!}.
+
+@item Expression results as strings
+You can write @samp{%@var{expr}} to evaluate the expression @var{expr}
+and use the result as a string.
+@end ftable
+
@node Ascii
@section @code{.ascii "@var{string}"}@dots{}
@code{.byte} expects zero or more expressions, separated by commas.
Each expression is assembled into the next byte.
-@node Comm
-@section @code{.comm @var{symbol} , @var{length} }
-
-@cindex @code{comm} directive
-@cindex symbol, common
-@code{.comm} declares a common symbol named @var{symbol}. When linking, a
-common symbol in one object file may be merged with a defined or common symbol
-of the same name in another object file. If @code{@value{LD}} does not see a
-definition for the symbol--just one or more common symbols--then it will
-allocate @var{length} bytes of uninitialized memory. @var{length} must be an
-absolute expression. If @code{@value{LD}} sees multiple common symbols with
-the same name, and they do not all have the same size, it will allocate space
-using the largest size.
-
-@ifset ELF
-When using ELF, the @code{.comm} directive takes an optional third argument.
-This is the desired alignment of the symbol, specified as a byte boundary (for
-example, an alignment of 16 means that the least significant 4 bits of the
-address should be zero). The alignment must be an absolute expression, and it
-must be a power of two. If @code{@value{LD}} allocates uninitialized memory
-for the common symbol, it will use the alignment when placing the symbol. If
-no alignment is specified, @command{@value{AS}} will set the alignment to the
-largest power of two less than or equal to the size of the symbol, up to a
-maximum of 16.
-@end ifset
-
-@ifset HPPA
-The syntax for @code{.comm} differs slightly on the HPPA. The syntax is
-@samp{@var{symbol} .comm, @var{length}}; @var{symbol} is optional.
-@end ifset
-
@node CFI directives
-@section @code{.cfi_startproc}
+@section @code{.cfi_startproc [simple]}
@cindex @code{cfi_startproc} directive
@code{.cfi_startproc} is used at the beginning of each function that
should have an entry in @code{.eh_frame}. It initializes some internal
-data structures and emits architecture dependent initial CFI instructions.
-Don't forget to close the function by
+data structures. Don't forget to close the function by
@code{.cfi_endproc}.
+Unless @code{.cfi_startproc} is used along with parameter @code{simple}
+it also emits some architecture dependent initial CFI instructions.
+
@section @code{.cfi_endproc}
@cindex @code{cfi_endproc} directive
@code{.cfi_endproc} is used at the end of a function where it closes its
unwind entry previously opened by
-@code{.cfi_startproc}. and emits it to @code{.eh_frame}.
+@code{.cfi_startproc}, and emits it to @code{.eh_frame}.
+
+@section @code{.cfi_personality @var{encoding} [, @var{exp}]}
+@code{.cfi_personality} defines personality routine and its encoding.
+@var{encoding} must be a constant determining how the personality
+should be encoded. If it is 255 (@code{DW_EH_PE_omit}), second
+argument is not present, otherwise second argument should be
+a constant or a symbol name. When using indirect encodings,
+the symbol provided should be the location where personality
+can be loaded from, not the personality routine itself.
+The default after @code{.cfi_startproc} is @code{.cfi_personality 0xff},
+no personality routine.
+
+@section @code{.cfi_lsda @var{encoding} [, @var{exp}]}
+@code{.cfi_lsda} defines LSDA and its encoding.
+@var{encoding} must be a constant determining how the LSDA
+should be encoded. If it is 255 (@code{DW_EH_PE_omit}), second
+argument is not present, otherwise second argument should be a constant
+or a symbol name. The default after @code{.cfi_startproc} is @code{.cfi_lsda 0xff},
+no LSDA.
@section @code{.cfi_def_cfa @var{register}, @var{offset}}
@code{.cfi_def_cfa} defines a rule for computing CFA as: @i{take
This is often easier to use, because the number will match the
code it's annotating.
+@section @code{.cfi_register @var{register1}, @var{register2}}
+Previous value of @var{register1} is saved in register @var{register2}.
+
+@section @code{.cfi_restore @var{register}}
+@code{.cfi_restore} says that the rule for @var{register} is now the
+same as it was at the beginning of the function, after all initial
+instruction added by @code{.cfi_startproc} were executed.
+
+@section @code{.cfi_undefined @var{register}}
+From now on the previous value of @var{register} can't be restored anymore.
+
+@section @code{.cfi_same_value @var{register}}
+Current value of @var{register} is the same like in the previous frame,
+i.e. no restoration needed.
+
+@section @code{.cfi_remember_state},
+First save all current rules for all registers by @code{.cfi_remember_state},
+then totally screw them up by subsequent @code{.cfi_*} directives and when
+everything is hopelessly bad, use @code{.cfi_restore_state} to restore
+the previous saved state.
+
+@section @code{.cfi_return_column @var{register}}
+Change return column @var{register}, i.e. the return address is either
+directly in @var{register} or can be accessed by rules for @var{register}.
+
+@section @code{.cfi_signal_frame}
+Mark current function as signal trampoline.
+
@section @code{.cfi_window_save}
SPARC register window has been saved.
might use this to add OS-specific CFI opcodes, or generic CFI
opcodes that GAS does not yet support.
+@section @code{.cfi_val_encoded_addr @var{register}, @var{encoding}, @var{label}}
+The current value of @var{register} is @var{label}. The value of @var{label}
+will be encoded in the output file according to @var{encoding}; see the
+description of @code{.cfi_personality} for details on this encoding.
+
+The usefulness of equating a register to a fixed label is probably
+limited to the return address register. Here, it can be useful to
+mark a code segment that has only one return address which is reached
+by a direct branch and no copy of the return address exists in memory
+or another register.
+
+@node Comm
+@section @code{.comm @var{symbol} , @var{length} }
+
+@cindex @code{comm} directive
+@cindex symbol, common
+@code{.comm} declares a common symbol named @var{symbol}. When linking, a
+common symbol in one object file may be merged with a defined or common symbol
+of the same name in another object file. If @code{@value{LD}} does not see a
+definition for the symbol--just one or more common symbols--then it will
+allocate @var{length} bytes of uninitialized memory. @var{length} must be an
+absolute expression. If @code{@value{LD}} sees multiple common symbols with
+the same name, and they do not all have the same size, it will allocate space
+using the largest size.
+
+@ifset ELF
+When using ELF, the @code{.comm} directive takes an optional third argument.
+This is the desired alignment of the symbol, specified as a byte boundary (for
+example, an alignment of 16 means that the least significant 4 bits of the
+address should be zero). The alignment must be an absolute expression, and it
+must be a power of two. If @code{@value{LD}} allocates uninitialized memory
+for the common symbol, it will use the alignment when placing the symbol. If
+no alignment is specified, @command{@value{AS}} will set the alignment to the
+largest power of two less than or equal to the size of the symbol, up to a
+maximum of 16.
+@end ifset
+
+@ifset HPPA
+The syntax for @code{.comm} differs slightly on the HPPA. The syntax is
+@samp{@var{symbol} .comm, @var{length}}; @var{symbol} is optional.
+@end ifset
+
@node Data
@section @code{.data @var{subsection}}
@cindex @code{else} directive
@code{.else} is part of the @command{@value{AS}} support for conditional
-assembly; @pxref{If,,@code{.if}}. It marks the beginning of a section
+assembly; see @ref{If,,@code{.if}}. It marks the beginning of a section
of code to be assembled if the condition for the preceding @code{.if}
was false.
@cindex @code{elseif} directive
@code{.elseif} is part of the @command{@value{AS}} support for conditional
-assembly; @pxref{If,,@code{.if}}. It is shorthand for beginning a new
+assembly; see @ref{If,,@code{.if}}. It is shorthand for beginning a new
@code{.if} block that would otherwise fill the entire @code{.else} section.
@node End
@cindex assigning values to symbols
@cindex symbols, assigning values to
This directive sets the value of @var{symbol} to @var{expression}.
-It is synonymous with @samp{.set}; @pxref{Set,,@code{.set}}.
+It is synonymous with @samp{.set}; see @ref{Set,,@code{.set}}.
@ifset HPPA
The syntax for @code{equ} on the HPPA is
@samp{@var{symbol} .equ @var{expression}}.
@end ifset
+@ifset Z80
+The syntax for @code{equ} on the Z80 is
+@samp{@var{symbol} equ @var{expression}}.
+On the Z80 it is an eror if @var{symbol} is already defined,
+but the symbol is not protected from later redefinition.
+Compare @ref{Equiv}.
+@end ifset
+
@node Equiv
@section @code{.equiv @var{symbol}, @var{expression}}
@cindex @code{equiv} directive
.endif
.equ SYM,VAL
@end smallexample
+plus it protects the symbol from later redefinition.
+
+@node Eqv
+@section @code{.eqv @var{symbol}, @var{expression}}
+@cindex @code{eqv} directive
+The @code{.eqv} directive is like @code{.equiv}, but no attempt is made to
+evaluate the expression or any part of it immediately. Instead each time
+the resulting symbol is used in an expression, a snapshot of its current
+value is taken.
@node Err
@section @code{.err}
@cindex @code{err} directive
If @command{@value{AS}} assembles a @code{.err} directive, it will print an error
message and, unless the @option{-Z} option was used, it will not generate an
-object file. This can be used to signal error an conditionally compiled code.
+object file. This can be used to signal an error in conditionally compiled code.
@node Error
@section @code{.error "@var{string}"}
include the value of @var{expression}. This can occasionally be useful inside
complex nested macros or conditional assembly.
-@ifclear no-file-dir
@node File
-@section @code{.file @var{string}}
-
+@section @code{.file}
@cindex @code{file} directive
+
+@ifclear no-file-dir
+There are two different versions of the @code{.file} directive. Targets
+that support DWARF2 line number information use the DWARF2 version of
+@code{.file}. Other targets use the default version.
+
+@subheading Default Version
+
@cindex logical file name
@cindex file name, logical
-@code{.file} tells @command{@value{AS}} that we are about to start a new logical
-file. @var{string} is the new file name. In general, the filename is
+This version of the @code{.file} directive tells @command{@value{AS}} that we
+are about to start a new logical file. The syntax is:
+
+@smallexample
+.file @var{string}
+@end smallexample
+
+@var{string} is the new file name. In general, the filename is
recognized whether or not it is surrounded by quotes @samp{"}; but if you wish
to specify an empty file name, you must give the quotes--@code{""}. This
statement may go away in future: it is only recognized to be compatible with
old @command{@value{AS}} programs.
-@ifset A29K
-In some configurations of @command{@value{AS}}, @code{.file} has already been
-removed to avoid conflicts with other assemblers. @xref{Machine Dependencies}.
-@end ifset
+
+@subheading DWARF2 Version
@end ifclear
+When emitting DWARF2 line number information, @code{.file} assigns filenames
+to the @code{.debug_line} file name table. The syntax is:
+
+@smallexample
+.file @var{fileno} @var{filename}
+@end smallexample
+
+The @var{fileno} operand should be a unique positive integer to use as the
+index of the entry in the table. The @var{filename} operand is a C string
+literal.
+
+The detail of filename indices is exposed to the user because the filename
+table is shared with the @code{.debug_info} section of the DWARF2 debugging
+information, and thus the user must know the exact indices that table
+entries will have.
+
@node Fill
@section @code{.fill @var{repeat} , @var{size} , @var{value}}
@ifset HPPA
On the HPPA, @code{.global} is not always enough to make it accessible to other
partial programs. You may need the HPPA-only @code{.EXPORT} directive as well.
-@xref{HPPA Directives,, HPPA Assembler Directives}.
+@xref{HPPA Directives, ,HPPA Assembler Directives}.
@end ifset
@ifset ELF
+@node Gnu_attribute
+@section @code{.gnu_attribute @var{tag},@var{value}}
+Record a @sc{gnu} object attribute for this file. @xref{Object Attributes}.
+
@node Hidden
@section @code{.hidden @var{names}}
@section @code{.ident}
@cindex @code{ident} directive
-This directive is used by some assemblers to place tags in object files.
-@command{@value{AS}} simply accepts the directive for source-file
-compatibility with such assemblers, but does not actually emit anything
-for it.
+
+This directive is used by some assemblers to place tags in object files. The
+behavior of this directive varies depending on the target. When using the
+a.out object file format, @command{@value{AS}} simply accepts the directive for
+source-file compatibility with existing assemblers, but does not emit anything
+for it. When using COFF, comments are emitted to the @code{.comment} or
+@code{.rdata} section, depending on the target. When using ELF, comments are
+emitted to the @code{.comment} section.
@node If
@section @code{.if @var{absolute expression}}
has been defined. Note a symbol which has been referenced but not yet defined
is considered to be undefined.
+@cindex @code{ifb} directive
+@item .ifb @var{text}
+Assembles the following section of code if the operand is blank (empty).
+
@cindex @code{ifc} directive
@item .ifc @var{string1},@var{string2}
Assembles the following section of code if the two strings are the same. The
@item .iflt @var{absolute expression}
Assembles the following section of code if the argument is less than zero.
+@cindex @code{ifnb} directive
+@item .ifnb @var{text}
+Like @code{.ifb}, but the sense of the test is reversed: this assembles the
+following section of code if the operand is non-blank (non-empty).
+
@cindex @code{ifnc} directive
@item .ifnc @var{string1},@var{string2}.
Like @code{.ifc}, but the sense of the test is reversed: this assembles the
@ifclear GENERIC
@ifset H8
-On the H8/500 and most forms of the H8/300, @code{.int} emits 16-bit
+On most forms of the H8/300, @code{.int} emits 16-bit
integers. On the H8/300H and the Renesas SH, however, @code{.int} emits
32-bit integers.
@end ifset
move d3,sp@@-
@end example
+For some caveats with the spelling of @var{symbol}, see also @ref{Macro}.
+
@node Irpc
@section @code{.irpc @var{symbol},@var{values}}@dots{}
move d3,sp@@-
@end example
+For some caveats with the spelling of @var{symbol}, see also the discussion
+at @xref{Macro}.
+
@node Lcomm
@section @code{.lcomm @var{symbol} , @var{length}}
@section @code{.line @var{line-number}}
@cindex @code{line} directive
-@end ifclear
-@ifset no-line-dir
-@node Ln
-@section @code{.ln @var{line-number}}
-
-@cindex @code{ln} directive
-@end ifset
@cindex logical line number
@ifset aout-bout
Change the logical line number. @var{line-number} must be an absolute
reported as on logical line number @var{line-number} @minus{} 1. One day
@command{@value{AS}} will no longer support this directive: it is recognized only
for compatibility with existing assembler programs.
-
-@ifset GENERIC
-@ifset A29K
-@emph{Warning:} In the AMD29K configuration of @value{AS}, this command is
-not available; use the synonym @code{.ln} in that context.
-@end ifset
-@end ifset
@end ifset
-@ifclear no-line-dir
Even though this is a directive associated with the @code{a.out} or
@code{b.out} object-code formats, @command{@value{AS}} still recognizes it
when producing COFF output, and treats @samp{.line} as though it
Warn if any of the duplicates do not have exactly the same contents.
@end table
-@node Ln
-@section @code{.ln @var{line-number}}
+@node List
+@section @code{.list}
-@cindex @code{ln} directive
-@ifclear no-line-dir
-@samp{.ln} is a synonym for @samp{.line}.
-@end ifclear
-@ifset no-line-dir
-Tell @command{@value{AS}} to change the logical line number. @var{line-number}
+@cindex @code{list} directive
+@cindex listing control, turning on
+Control (in conjunction with the @code{.nolist} directive) whether or
+not assembly listings are generated. These two directives maintain an
+internal counter (which is zero initially). @code{.list} increments the
+counter, and @code{.nolist} decrements it. Assembly listings are
+generated whenever the counter is greater than zero.
+
+By default, listings are disabled. When you enable them (with the
+@samp{-a} command line option; @pxref{Invoking,,Command-Line Options}),
+the initial value of the listing counter is one.
+
+@node Ln
+@section @code{.ln @var{line-number}}
+
+@cindex @code{ln} directive
+@ifclear no-line-dir
+@samp{.ln} is a synonym for @samp{.line}.
+@end ifclear
+@ifset no-line-dir
+Tell @command{@value{AS}} to change the logical line number. @var{line-number}
must be an absolute expression. The next line has that logical
line number, so any other statements on the current line (after a
statement separator character @code{;}) are reported as on logical
@end ifset
@end ifset
-@node MRI
-@section @code{.mri @var{val}}
+@node Loc
+@section @code{.loc @var{fileno} @var{lineno} [@var{column}] [@var{options}]}
+@cindex @code{loc} directive
+When emitting DWARF2 line number information,
+the @code{.loc} directive will add a row to the @code{.debug_line} line
+number matrix corresponding to the immediately following assembly
+instruction. The @var{fileno}, @var{lineno}, and optional @var{column}
+arguments will be applied to the @code{.debug_line} state machine before
+the row is added.
-@cindex @code{mri} directive
-@cindex MRI mode, temporarily
-If @var{val} is non-zero, this tells @command{@value{AS}} to enter MRI mode. If
-@var{val} is zero, this tells @command{@value{AS}} to exit MRI mode. This change
-affects code assembled until the next @code{.mri} directive, or until the end
-of the file. @xref{M, MRI mode, MRI mode}.
+The @var{options} are a sequence of the following tokens in any order:
-@node List
-@section @code{.list}
+@table @code
+@item basic_block
+This option will set the @code{basic_block} register in the
+@code{.debug_line} state machine to @code{true}.
-@cindex @code{list} directive
-@cindex listing control, turning on
-Control (in conjunction with the @code{.nolist} directive) whether or
-not assembly listings are generated. These two directives maintain an
-internal counter (which is zero initially). @code{.list} increments the
-counter, and @code{.nolist} decrements it. Assembly listings are
-generated whenever the counter is greater than zero.
+@item prologue_end
+This option will set the @code{prologue_end} register in the
+@code{.debug_line} state machine to @code{true}.
-By default, listings are disabled. When you enable them (with the
-@samp{-a} command line option; @pxref{Invoking,,Command-Line Options}),
-the initial value of the listing counter is one.
+@item epilogue_begin
+This option will set the @code{epilogue_begin} register in the
+@code{.debug_line} state machine to @code{true}.
+
+@item is_stmt @var{value}
+This option will set the @code{is_stmt} register in the
+@code{.debug_line} state machine to @code{value}, which must be
+either 0 or 1.
+
+@item isa @var{value}
+This directive will set the @code{isa} register in the @code{.debug_line}
+state machine to @var{value}, which must be an unsigned integer.
+
+@end table
+
+@node Loc_mark_labels
+@section @code{.loc_mark_labels @var{enable}}
+@cindex @code{loc_mark_labels} directive
+When emitting DWARF2 line number information,
+the @code{.loc_mark_labels} directive makes the assembler emit an entry
+to the @code{.debug_line} line number matrix with the @code{basic_block}
+register in the state machine set whenever a code label is seen.
+The @var{enable} argument should be either 1 or 0, to enable or disable
+this function respectively.
+
+@ifset ELF
+@node Local
+@section @code{.local @var{names}}
+
+@cindex @code{local} directive
+This directive, which is available for ELF targets, marks each symbol in
+the comma-separated list of @code{names} as a local symbol so that it
+will not be externally visible. If the symbols do not already exist,
+they will be created.
+
+For targets where the @code{.lcomm} directive (@pxref{Lcomm}) does not
+accept an alignment argument, which is the case for most ELF targets,
+the @code{.local} directive can be used in combination with @code{.comm}
+(@pxref{Comm}) to define aligned local common data.
+@end ifset
@node Long
@section @code{.long @var{expressions}}
@cindex @code{long} directive
-@code{.long} is the same as @samp{.int}, @pxref{Int,,@code{.int}}.
+@code{.long} is the same as @samp{.int}. @xref{Int,,@code{.int}}.
@ignore
@c no one seems to know what this is for or whether this description is
@cindex @code{macro} directive
Begin the definition of a macro called @var{macname}. If your macro
definition requires arguments, specify their names after the macro name,
-separated by commas or spaces. You can supply a default value for any
-macro argument by following the name with @samp{=@var{deflt}}. For
-example, these are all valid @code{.macro} statements:
+separated by commas or spaces. You can qualify the macro argument to
+indicate whether all invocations must specify a non-blank value (through
+@samp{:@code{req}}), or whether it takes all of the remaining arguments
+(through @samp{:@code{vararg}}). You can supply a default value for any
+macro argument by following the name with @samp{=@var{deflt}}. You
+cannot define two macros with the same @var{macname} unless it has been
+subject to the @code{.purgem} directive (@pxref{Purgem}) between the two
+definitions. For example, these are all valid @code{.macro} statements:
@table @code
@item .macro comm
Begin the definition of a macro called @code{comm}, which takes no
arguments.
-@item .macro plus1 p, p1
+@item .macro plus1 p, p1
@itemx .macro plus1 p p1
Either statement begins the definition of a macro called @code{plus1},
which takes two arguments; within the macro definition, write
@var{a} and @samp{\p2} evaluating to @var{b}), or as @samp{reserve_str
,@var{b}} (with @samp{\p1} evaluating as the default, in this case
@samp{0}, and @samp{\p2} evaluating to @var{b}).
-@end table
+
+@item .macro m p1:req, p2=0, p3:vararg
+Begin the definition of a macro called @code{m}, with at least three
+arguments. The first argument must always have a value specified, but
+not the second, which instead has a default value. The third formal
+will get assigned all remaining arguments specified at invocation time.
When you call a macro, you can specify the argument values either by
position, or by keyword. For example, @samp{sum 9,17} is equivalent to
@samp{sum to=17, from=9}.
+@end table
+
+Note that since each of the @var{macargs} can be an identifier exactly
+as any other one permitted by the target architecture, there may be
+occasional problems if the target hand-crafts special meanings to certain
+characters when they occur in a special position. For example, if the colon
+(@code{:}) is generally permitted to be part of a symbol name, but the
+architecture specific code special-cases it when occurring as the final
+character of a symbol (to denote a label), then the macro parameter
+replacement code will have no way of knowing that and consider the whole
+construct (including the colon) an identifier, and check only this
+identifier for being the subject to parameter substitution. So for example
+this macro definition:
+
+@example
+ .macro label l
+\l:
+ .endm
+@end example
+
+might not work as expected. Invoking @samp{label foo} might not create a label
+called @samp{foo} but instead just insert the text @samp{\l:} into the
+assembler source, probably generating an error about an unrecognised
+identifier.
+
+Similarly problems might occur with the period character (@samp{.})
+which is often allowed inside opcode names (and hence identifier names). So
+for example constructing a macro to build an opcode from a base name and a
+length specifier like this:
+
+@example
+ .macro opcode base length
+ \base.\length
+ .endm
+@end example
+
+and invoking it as @samp{opcode store l} will not create a @samp{store.l}
+instruction but instead generate some kind of error as the assembler tries to
+interpret the text @samp{\base.\length}.
+
+There are several possible ways around this problem:
+
+@table @code
+@item Insert white space
+If it is possible to use white space characters then this is the simplest
+solution. eg:
+
+@example
+ .macro label l
+\l :
+ .endm
+@end example
+
+@item Use @samp{\()}
+The string @samp{\()} can be used to separate the end of a macro argument from
+the following text. eg:
+
+@example
+ .macro opcode base length
+ \base\().\length
+ .endm
+@end example
+
+@item Use the alternate macro syntax mode
+In the alternative macro syntax mode the ampersand character (@samp{&}) can be
+used as a separator. eg:
+
+@example
+ .altmacro
+ .macro label l
+l&:
+ .endm
+@end example
+@end table
+
+Note: this problem of correctly identifying string parameters to pseudo ops
+also applies to the identifiers used in @code{.irp} (@pxref{Irp})
+and @code{.irpc} (@pxref{Irpc}) as well.
+
@item .endm
@cindex @code{endm} directive
Mark the end of a macro definition.
@xref{Altmacro,,@code{.altmacro}}.
@end ftable
-@node Altmacro
-@section @code{.altmacro}
-Enable alternate macro mode, enabling:
-
-@ftable @code
-@item LOCAL @var{name} [ , @dots{} ]
-One additional directive, @code{LOCAL}, is available. It is used to
-generate a string replacement for each of the @var{name} arguments, and
-replace any instances of @var{name} in each macro expansion. The
-replacement string is unique in the assembly, and different for each
-separate macro expansion. @code{LOCAL} allows you to write macros that
-define symbols, without fear of conflict between separate macro expansions.
-
-@item String delimiters
-You can write strings delimited in these other ways besides
-@code{"@var{string}"}:
-
-@table @code
-@item '@var{string}'
-You can delimit strings with single-quote charaters.
-
-@item <@var{string}>
-You can delimit strings with matching angle brackets.
-@end table
-
-@item single-character string escape
-To include any single character literally in a string (even if the
-character would otherwise have some special meaning), you can prefix the
-character with @samp{!} (an exclamation mark). For example, you can
-write @samp{<4.3 !> 5.4!!>} to get the literal text @samp{4.3 > 5.4!}.
+@node MRI
+@section @code{.mri @var{val}}
-@item Expression results as strings
-You can write @samp{%@var{expr}} to evaluate the expression @var{expr}
-and use the result as a string.
-@end ftable
+@cindex @code{mri} directive
+@cindex MRI mode, temporarily
+If @var{val} is non-zero, this tells @command{@value{AS}} to enter MRI mode. If
+@var{val} is zero, this tells @command{@value{AS}} to exit MRI mode. This change
+affects code assembled until the next @code{.mri} directive, or until the end
+of the file. @xref{M, MRI mode, MRI mode}.
@node Noaltmacro
@section @code{.noaltmacro}
-Disable alternate macro mode. @ref{Altmacro}
+Disable alternate macro mode. @xref{Altmacro}.
@node Nolist
@section @code{.nolist}
the endianness of the processor). If it skips 1 or 3 bytes, the fill value is
undefined.
+@ifset ELF
+@node PopSection
+@section @code{.popsection}
+
+@cindex @code{popsection} directive
+@cindex Section Stack
+This is one of the ELF section stack manipulation directives. The others are
+@code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}),
+@code{.pushsection} (@pxref{PushSection}), and @code{.previous}
+(@pxref{Previous}).
+
+This directive replaces the current section (and subsection) with the top
+section (and subsection) on the section stack. This section is popped off the
+stack.
+@end ifset
+
@ifset ELF
@node Previous
@section @code{.previous}
(@pxref{PopSection}).
This directive swaps the current section (and subsection) with most recently
-referenced section (and subsection) prior to this one. Multiple
+referenced section/subsection pair prior to this one. Multiple
@code{.previous} directives in a row will flip between two sections (and their
-subsections).
+subsections). For example:
-In terms of the section stack, this directive swaps the current section with
-the top section on the section stack.
-@end ifset
+@smallexample
+.section A
+ .subsection 1
+ .word 0x1234
+ .subsection 2
+ .word 0x5678
+.previous
+ .word 0x9abc
+@end smallexample
-@ifset ELF
-@node PopSection
-@section @code{.popsection}
+Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of
+section A. Whilst:
-@cindex @code{popsection} directive
-@cindex Section Stack
-This is one of the ELF section stack manipulation directives. The others are
-@code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}),
-@code{.pushsection} (@pxref{PushSection}), and @code{.previous}
-(@pxref{Previous}).
+@smallexample
+.section A
+.subsection 1
+ # Now in section A subsection 1
+ .word 0x1234
+.section B
+.subsection 0
+ # Now in section B subsection 0
+ .word 0x5678
+.subsection 1
+ # Now in section B subsection 1
+ .word 0x9abc
+.previous
+ # Now in section B subsection 0
+ .word 0xdef0
+@end smallexample
-This directive replaces the current section (and subsection) with the top
-section (and subsection) on the section stack. This section is popped off the
-stack.
+Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of
+section B and 0x9abc into subsection 1 of section B.
+
+In terms of the section stack, this directive swaps the current section with
+the top section on the section stack.
@end ifset
@node Print
@ifset ELF
@node PushSection
-@section @code{.pushsection @var{name} , @var{subsection}}
+@section @code{.pushsection @var{name} [, @var{subsection}] [, "@var{flags}"[, @@@var{type}[,@var{arguments}]]]}
@cindex @code{pushsection} directive
@cindex Section Stack
This directive pushes the current section (and subsection) onto the
top of the section stack, and then replaces the current section and
-subsection with @code{name} and @code{subsection}.
+subsection with @code{name} and @code{subsection}. The optional
+@code{flags}, @code{type} and @code{arguments} are treated the same
+as in the @code{.section} (@pxref{Section}) directive.
@end ifset
@node Quad
@cindex integer, 16-byte
@end ifset
+@node Reloc
+@section @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]}
+
+@cindex @code{reloc} directive
+Generate a relocation at @var{offset} of type @var{reloc_name} with value
+@var{expression}. If @var{offset} is a number, the relocation is generated in
+the current section. If @var{offset} is an expression that resolves to a
+symbol plus offset, the relocation is generated in the given symbol's section.
+@var{expression}, if present, must resolve to a symbol plus addend or to an
+absolute value, but note that not all targets support an addend. e.g. ELF REL
+targets such as i386 store an addend in the section contents rather than in the
+relocation. This low level interface does not support addends stored in the
+section.
+
@node Rept
@section @code{.rept @var{count}}
@smallexample
.section @var{name}[, "@var{flags}"]
-.section @var{name}[, @var{subsegment}]
+.section @var{name}[, @var{subsection}]
@end smallexample
If the optional argument is quoted, it is taken as flags to use for the
will be as if no flags had been specified at all.
If the optional argument to the @code{.section} directive is not quoted, it is
-taken as a subsegment number (@pxref{Sub-Sections}).
+taken as a subsection number (@pxref{Sub-Sections}).
@end ifset
@ifset ELF
For ELF targets, the @code{.section} directive is used like this:
@smallexample
-.section @var{name} [, "@var{flags}"[, @@@var{type}[,@var{flag_specific_arguments}]]
+.section @var{name} [, "@var{flags}"[, @@@var{type}[,@var{flag_specific_arguments}]]]
@end smallexample
The optional @var{flags} argument is a quoted string which may contain any
@code{%} character.
If @var{flags} contains the @code{M} symbol then the @var{type} argument must
-be specified as well as an extra argument - @var{entsize} - like this:
+be specified as well as an extra argument---@var{entsize}---like this:
@smallexample
.section @var{name} , "@var{flags}"M, @@@var{type}, @var{entsize}
an alias for comdat
@end table
-Note - if both the @var{M} and @var{G} flags are present then the fields for
+Note: if both the @var{M} and @var{G} flags are present then the fields for
the Merge flag should come first, like this:
@smallexample
@samp{@var{symbol} .set @var{expression}}.
@end ifset
+@ifset Z80
+On Z80 @code{set} is a real instruction, use
+@samp{@var{symbol} defl @var{expression}} instead.
+@end ifset
+
@node Short
@section @code{.short @var{expressions}}
@xref{Word,,@code{.word}}.
In some configurations, however, @code{.short} and @code{.word} generate
-numbers of different lengths; @pxref{Machine Dependencies}.
+numbers of different lengths. @xref{Machine Dependencies}.
@end ifset
@ifclear GENERIC
@ifset W16
@end ifset
@end ifset
-@node Sleb128
-@section @code{.sleb128 @var{expressions}}
-
-@cindex @code{sleb128} directive
-@var{sleb128} stands for ``signed little endian base 128.'' This is a
-compact, variable length representation of numbers used by the DWARF
-symbolic debugging format. @xref{Uleb128,@code{.uleb128}}.
-
@ifclear no-space-dir
@node Skip
@section @code{.skip @var{size} , @var{fill}}
@var{size} and @var{fill} are absolute expressions. If the comma and
@var{fill} are omitted, @var{fill} is assumed to be zero. This is the same as
@samp{.space}.
+@end ifclear
+
+@node Sleb128
+@section @code{.sleb128 @var{expressions}}
+
+@cindex @code{sleb128} directive
+@var{sleb128} stands for ``signed little endian base 128.'' This is a
+compact, variable length representation of numbers used by the DWARF
+symbolic debugging format. @xref{Uleb128, ,@code{.uleb128}}.
+@ifclear no-space-dir
@node Space
@section @code{.space @var{size} , @var{fill}}
@end ifset
@end ifclear
-@ifset A29K
-@ifclear GENERIC
-@node Space
-@section @code{.space}
-@cindex @code{space} directive
-@end ifclear
-On the AMD 29K, this directive is ignored; it is accepted for
-compatibility with other AMD 29K assemblers.
-
-@quotation
-@emph{Warning:} In most versions of the @sc{gnu} assembler, the directive
-@code{.space} has the effect of @code{.block} @xref{Machine Dependencies}.
-@end quotation
-@end ifset
-
@ifset have-stabs
@node Stab
@section @code{.stabd, .stabn, .stabs}
@c end have-stabs
@node String
-@section @code{.string} "@var{str}"
+@section @code{.string} "@var{str}", @code{.string8} "@var{str}", @code{.string16}
+"@var{str}", @code{.string32} "@var{str}", @code{.string64} "@var{str}"
@cindex string, copying to object file
+@cindex string8, copying to object file
+@cindex string16, copying to object file
+@cindex string32, copying to object file
+@cindex string64, copying to object file
@cindex @code{string} directive
+@cindex @code{string8} directive
+@cindex @code{string16} directive
+@cindex @code{string32} directive
+@cindex @code{string64} directive
Copy the characters in @var{str} to the object file. You may specify more than
one string to copy, separated by commas. Unless otherwise specified for a
particular machine, the assembler marks the end of each string with a 0 byte.
You can use any of the escape sequences described in @ref{Strings,,Strings}.
+The variants @code{string16}, @code{string32} and @code{string64} differ from
+the @code{string} pseudo opcode in that each 8-bit character from @var{str} is
+copied and expanded to 16, 32 or 64 bits respectively. The expanded characters
+are stored in target endianness byte order.
+
+Example:
+@smallexample
+ .string32 "BYE"
+expands to:
+ .string "B\0\0\0Y\0\0\0E\0\0\0" /* On little endian targets. */
+ .string "\0\0\0B\0\0\0Y\0\0\0E" /* On big endian targets. */
+@end smallexample
+
+
@node Struct
@section @code{.struct @var{expression}}
This sets the type of symbol @var{name} to be either a
function symbol or an object symbol. There are five different syntaxes
supported for the @var{type description} field, in order to provide
-compatibility with various other assemblers. The syntaxes supported are:
+compatibility with various other assemblers.
+
+Because some of the characters used in these syntaxes (such as @samp{@@} and
+@samp{#}) are comment characters for some architectures, some of the syntaxes
+below do not work on all architectures. The first variant will be accepted by
+the GNU assembler on all architectures so that variant should be used for
+maximum portability, if you do not need to assemble your code with other
+assemblers.
+
+The syntaxes supported are:
@smallexample
- .type <name>,#function
- .type <name>,#object
-
- .type <name>,@@function
- .type <name>,@@object
-
- .type <name>,%function
- .type <name>,%object
-
- .type <name>,"function"
- .type <name>,"object"
-
- .type <name> STT_FUNCTION
- .type <name> STT_OBJECT
+ .type <name> STT_<TYPE_IN_UPPER_CASE>
+ .type <name>,#<type>
+ .type <name>,@@<type>
+ .type <name>,%<type>
+ .type <name>,"<type>"
@end smallexample
+
+The types supported are:
+
+@table @gcctabopt
+@item STT_FUNC
+@itemx function
+Mark the symbol as being a function name.
+
+@item STT_OBJECT
+@itemx object
+Mark the symbol as being a data object.
+
+@item STT_TLS
+@itemx tls_object
+Mark the symbol as being a thead-local data object.
+
+@item STT_COMMON
+@itemx common
+Mark the symbol as being a common data object.
+
+@item STT_NOTYPE
+@itemx notype
+Does not mark the symbol in any way. It is supported just for completeness.
+
+@end table
+
+Note: Some targets support extra types in addition to those listed above.
+
@end ifset
@end ifset
@cindex @code{uleb128} directive
@var{uleb128} stands for ``unsigned little endian base 128.'' This is a
compact, variable length representation of numbers used by the DWARF
-symbolic debugging format. @xref{Sleb128,@code{.sleb128}}.
+symbolic debugging format. @xref{Sleb128, ,@code{.sleb128}}.
@ifset COFF
@node Val
This directive finds the symbol @code{child} and finds or creates the symbol
@code{parent} and then creates a @code{VTABLE_INHERIT} relocation for the
parent whose addend is the value of the child symbol. As a special case the
-parent name of @code{0} is treated as refering the @code{*ABS*} section.
+parent name of @code{0} is treated as referring to the @code{*ABS*} section.
@end ifset
@node Warning
When a weak symbol is created that is not an alias, GAS creates an
alternate symbol to hold the default value.
+@node Weakref
+@section @code{.weakref @var{alias}, @var{target}}
+
+@cindex @code{weakref} directive
+This directive creates an alias to the target symbol that enables the symbol to
+be referenced with weak-symbol semantics, but without actually making it weak.
+If direct references or definitions of the symbol are present, then the symbol
+will not be weak, but if all references to it are through weak references, the
+symbol will be marked as weak in the symbol table.
+
+The effect is equivalent to moving all references to the alias to a separate
+assembly source file, renaming the alias to the symbol in it, declaring the
+symbol as weak there, and running a reloadable link to merge the object files
+resulting from the assembly of the new source file and the old source file that
+had the references to the alias removed.
+
+The alias itself never makes to the symbol table, and is entirely handled
+within the assembler.
+
@node Word
@section @code{.word @var{expressions}}
@item .line
@end table
+@ifset ELF
+@node Object Attributes
+@chapter Object Attributes
+@cindex object attributes
+
+@command{@value{AS}} assembles source files written for a specific architecture
+into object files for that architecture. But not all object files are alike.
+Many architectures support incompatible variations. For instance, floating
+point arguments might be passed in floating point registers if the object file
+requires hardware floating point support---or floating point arguments might be
+passed in integer registers if the object file supports processors with no
+hardware floating point unit. Or, if two objects are built for different
+generations of the same architecture, the combination may require the
+newer generation at run-time.
+
+This information is useful during and after linking. At link time,
+@command{@value{LD}} can warn about incompatible object files. After link
+time, tools like @command{gdb} can use it to process the linked file
+correctly.
+
+Compatibility information is recorded as a series of object attributes. Each
+attribute has a @dfn{vendor}, @dfn{tag}, and @dfn{value}. The vendor is a
+string, and indicates who sets the meaning of the tag. The tag is an integer,
+and indicates what property the attribute describes. The value may be a string
+or an integer, and indicates how the property affects this object. Missing
+attributes are the same as attributes with a zero value or empty string value.
+
+Object attributes were developed as part of the ABI for the ARM Architecture.
+The file format is documented in @cite{ELF for the ARM Architecture}.
+
+@menu
+* GNU Object Attributes:: @sc{gnu} Object Attributes
+* Defining New Object Attributes:: Defining New Object Attributes
+@end menu
+
+@node GNU Object Attributes
+@section @sc{gnu} Object Attributes
+
+The @code{.gnu_attribute} directive records an object attribute
+with vendor @samp{gnu}.
+
+Except for @samp{Tag_compatibility}, which has both an integer and a string for
+its value, @sc{gnu} attributes have a string value if the tag number is odd and
+an integer value if the tag number is even. The second bit (@code{@var{tag} &
+2} is set for architecture-independent attributes and clear for
+architecture-dependent ones.
+
+@subsection Common @sc{gnu} attributes
+
+These attributes are valid on all architectures.
+
+@table @r
+@item Tag_compatibility (32)
+The compatibility attribute takes an integer flag value and a vendor name. If
+the flag value is 0, the file is compatible with other toolchains. If it is 1,
+then the file is only compatible with the named toolchain. If it is greater
+than 1, the file can only be processed by other toolchains under some private
+arrangement indicated by the flag value and the vendor name.
+@end table
+
+@subsection MIPS Attributes
+
+@table @r
+@item Tag_GNU_MIPS_ABI_FP (4)
+The floating-point ABI used by this object file. The value will be:
+
+@itemize @bullet
+@item
+0 for files not affected by the floating-point ABI.
+@item
+1 for files using the hardware floating-point with a standard double-precision
+FPU.
+@item
+2 for files using the hardware floating-point ABI with a single-precision FPU.
+@item
+3 for files using the software floating-point ABI.
+@item
+4 for files using the hardware floating-point ABI with 64-bit wide
+double-precision floating-point registers and 32-bit wide general
+purpose registers.
+@end itemize
+@end table
+
+@subsection PowerPC Attributes
+
+@table @r
+@item Tag_GNU_Power_ABI_FP (4)
+The floating-point ABI used by this object file. The value will be:
+
+@itemize @bullet
+@item
+0 for files not affected by the floating-point ABI.
+@item
+1 for files using double-precision hardware floating-point ABI.
+@item
+2 for files using the software floating-point ABI.
+@item
+3 for files using single-precision hardware floating-point ABI.
+@end itemize
+
+@item Tag_GNU_Power_ABI_Vector (8)
+The vector ABI used by this object file. The value will be:
+
+@itemize @bullet
+@item
+0 for files not affected by the vector ABI.
+@item
+1 for files using general purpose registers to pass vectors.
+@item
+2 for files using AltiVec registers to pass vectors.
+@item
+3 for files using SPE registers to pass vectors.
+@end itemize
+@end table
+
+@node Defining New Object Attributes
+@section Defining New Object Attributes
+
+If you want to define a new @sc{gnu} object attribute, here are the places you
+will need to modify. New attributes should be discussed on the @samp{binutils}
+mailing list.
+
+@itemize @bullet
+@item
+This manual, which is the official register of attributes.
+@item
+The header for your architecture @file{include/elf}, to define the tag.
+@item
+The @file{bfd} support file for your architecture, to merge the attribute
+and issue any appropriate link warnings.
+@item
+Test cases in @file{ld/testsuite} for merging and link warnings.
+@item
+@file{binutils/readelf.c} to display your attribute.
+@item
+GCC, if you want the compiler to mark the attribute automatically.
+@end itemize
+
+@end ifset
+
@ifset GENERIC
@node Machine Dependencies
@chapter Machine Dependent Features
subject, see the hardware manufacturer's manual.
@menu
-@ifset A29K
-* AMD29K-Dependent:: AMD 29K Dependent Features
-@end ifset
@ifset ALPHA
* Alpha-Dependent:: Alpha Dependent Features
@end ifset
@ifset ARM
* ARM-Dependent:: ARM Dependent Features
@end ifset
+@ifset AVR
+* AVR-Dependent:: AVR Dependent Features
+@end ifset
+@ifset BFIN
+* BFIN-Dependent:: BFIN Dependent Features
+@end ifset
+@ifset CR16
+* CR16-Dependent:: CR16 Dependent Features
+@end ifset
@ifset CRIS
* CRIS-Dependent:: CRIS Dependent Features
@end ifset
@ifset H8/300
* H8/300-Dependent:: Renesas H8/300 Dependent Features
@end ifset
-@ifset H8/500
-* H8/500-Dependent:: Renesas H8/500 Dependent Features
-@end ifset
@ifset HPPA
* HPPA-Dependent:: HPPA Dependent Features
@end ifset
@ifset IP2K
* IP2K-Dependent:: IP2K Dependent Features
@end ifset
+@ifset LM32
+* LM32-Dependent:: LM32 Dependent Features
+@end ifset
+@ifset M32C
+* M32C-Dependent:: M32C Dependent Features
+@end ifset
@ifset M32R
* M32R-Dependent:: M32R Dependent Features
@end ifset
@ifset M68HC11
* M68HC11-Dependent:: M68HC11 and 68HC12 Dependent Features
@end ifset
-@ifset M880X0
-* M88K-Dependent:: M880x0 Dependent Features
-@end ifset
@ifset MIPS
* MIPS-Dependent:: MIPS Dependent Features
@end ifset
@ifset XTENSA
* Xtensa-Dependent:: Xtensa Dependent Features
@end ifset
+@ifset Z80
+* Z80-Dependent:: Z80 Dependent Features
+@end ifset
@ifset Z8000
* Z8000-Dependent:: Z8000 Dependent Features
@end ifset
@c node and sectioning commands; hence the repetition of @chapter BLAH
@c in both conditional blocks.
-@ifset A29K
-@include c-a29k.texi
-@end ifset
-
@ifset ALPHA
@include c-alpha.texi
@end ifset
@include c-arm.texi
@end ifset
+@ifset AVR
+@include c-avr.texi
+@end ifset
+
+@ifset BFIN
+@include c-bfin.texi
+@end ifset
+
+@ifset CR16
+@include c-cr16.texi
+@end ifset
+
@ifset CRIS
@include c-cris.texi
@end ifset
@menu
* H8/300-Dependent:: Renesas H8/300 Dependent Features
-* H8/500-Dependent:: Renesas H8/500 Dependent Features
* SH-Dependent:: Renesas SH Dependent Features
@end menu
@lowersections
@include c-h8300.texi
@end ifset
-@ifset H8/500
-@include c-h8500.texi
-@end ifset
-
@ifset HPPA
@include c-hppa.texi
@end ifset
@include c-ip2k.texi
@end ifset
+@ifset LM32
+@include c-lm32.texi
+@end ifset
+
+@ifset M32C
+@include c-m32c.texi
+@end ifset
+
@ifset M32R
@include c-m32r.texi
@end ifset
@include c-m68hc11.texi
@end ifset
-@ifset M880X0
-@include c-m88k.texi
-@end ifset
-
@ifset MIPS
@include c-mips.texi
@end ifset
@include c-tic54x.texi
@end ifset
+@ifset Z80
+@include c-z80.texi
+@end ifset
+
@ifset Z8000
@include c-z8k.texi
@end ifset
individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
distribution.
+@ifset BUGURL
In any event, we also recommend that you send bug reports for @command{@value{AS}}
-to @samp{bug-binutils@@gnu.org}.
+to @value{BUGURL}.
+@end ifset
The fundamental principle of reporting bugs usefully is this:
@strong{report all the facts}. If you are not sure whether to state a
Even if the problem you experience is a fatal signal, you should still say so
explicitly. Suppose something strange is going on, such as, your copy of
-@command{@value{AS}} is out of synch, or you have encountered a bug in the C
+@command{@value{AS}} is out of sync, or you have encountered a bug in the C
library on your system. (This has happened!) Your copy might crash and ours
would not. If you told us to expect a crash, then when ours fails to crash, we
would know that the bug was not happening for us. If you had not told us to
(which hasn't been merged in yet). Ralph Campbell worked with the MIPS code to
support a.out format.
-Support for the Zilog Z8k and Renesas H8/300 and H8/500 processors (tc-z8k,
-tc-h8300, tc-h8500), and IEEE 695 object file format (obj-ieee), was written by
+Support for the Zilog Z8k and Renesas H8/300 processors (tc-z8k,
+tc-h8300), and IEEE 695 object file format (obj-ieee), was written by
Steve Chamberlain of Cygnus Support. Steve also modified the COFF back end to
use BFD for some low-level operations, for use with the H8/300 and AMD 29k
targets.
flavors.
David Heine, Sterling Augustine, Bob Wilson and John Ruttenberg from Tensilica,
-Inc. added support for Xtensa processors.
+Inc.@: added support for Xtensa processors.
Several engineers at Cygnus Support have also provided many small bug fixes and
configuration enhancements.
+Jon Beniston added support for the Lattice Mico32 architecture.
+
Many others have contributed large or small bugfixes and enhancements. If
you have contributed significant work and are not mentioned on this list, and
want to be, let us know. Some of the history has been lost; we are not
intentionally leaving anyone out.
+@node GNU Free Documentation License
+@appendix GNU Free Documentation License
@include fdl.texi
-@node Index
-@unnumbered Index
+@node AS Index
+@unnumbered AS Index
@printindex cp
-@contents
@bye
@c Local Variables:
@c fill-column: 79
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