Power-Programmierung/CD2.mdf/gnu/djgpp/docs/gas/as.inf

GNU Info File | 1993-11-13 | 243.0 KB | 6,346 lines

This is Info file as.inf, produced by Makeinfo-1.55 from the input file
as.tex.

START-INFO-DIR-ENTRY
* As::                          The GNU assembler.
END-INFO-DIR-ENTRY

   This file documents the GNU Assembler "as".

   Copyright (C) 1991, 1992, 1993 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the section entitled "GNU General Public License" is included
exactly as in the original, and provided that the entire resulting
derived work is distributed under the terms of a permission notice
identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the section entitled "GNU General Public License"
may be included in a translation approved by the Free Software
Foundation instead of in the original English.


File: as,  Node: Top,  Next: Overview,  Prev: (DIR),  Up: (DIR)

Using as
********

   This file is a user guide to the GNU assembler `as'.

* Menu:

* Overview::                    Overview
* Invoking::                    Command-Line Options
* Syntax::                      Syntax
* Sections::                    Sections and Relocation
* Symbols::                     Symbols
* Expressions::                 Expressions
* Pseudo Ops::                  Assembler Directives
* Machine Dependencies::        Machine Dependent Features

* Copying::                     GNU GENERAL PUBLIC LICENSE

* Acknowledgements::            Who Did What

* Index::                       Index


File: as,  Node: Overview,  Next: Invoking,  Prev: Top,  Up: Top

Overview
********

   Here is a brief summary of how to invoke `as'.  For details, *note
Comand-Line Options: Invoking..

       as [ -a[dhlns] ] [ -D ] [ -f ]
        [ -I PATH ] [ -K ] [ -L ]
        [ -o OBJFILE ] [ -R ] [ -v ] [ -w ]
        [ -Av6 | -Av7 | -Av8 | -Asparclite | -bump ]
        [ -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC ]
        [ -b ] [ -norelax ]
        [ -l ] [ -m68000 | -m68010 | -m68020 | ... ]
        [ -- | FILES ... ]

`-a[dhlns]'
     Turn on listings; `-ad', omit debugging pseudo-ops from listing,
     `-ah', include high-level source, `-al', assembly listing, `-an',
     no forms processing, `-as', symbols.  These options may be
     combined; *e.g.*, `-aln' for assembly listing without forms
     processing.  By itself, `-a' defaults to `-ahls' -- that is, all
     listings turned on.

`-D'
     This option is accepted only for script compatibility with calls to
     other assemblers; it has no effect on `as'.

`-f'
     "fast"--skip whitespace and comment preprocessing (assume source is
     compiler output)

`-I PATH'
     Add PATH to the search list for `.include' directives

`-K'
     Issue warnings when difference tables altered for long
     displacements.

`-L'
     Keep (in symbol table) local symbols, starting with `L'

`-o OBJFILE'
     Name the object-file output from `as'

`-R'
     Fold data section into text section

`-v'
     Announce `as' version

`-W'
     Suppress warning messages

`-- | FILES ...'
     Standard input, or source files to assemble.

   The following options are available when as is configured for the
Intel 80960 processor.

`-ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC'
     Specify which variant of the 960 architecture is the target.

`-b'
     Add code to collect statistics about branches taken.

`-norelax'
     Do not alter compare-and-branch instructions for long
     displacements; error if necessary.

   The following options are available when as is configured for the
Motorola 68000 series.

`-l'
     Shorten references to undefined symbols, to one word instead of
     two.

`-m68000 | -m68008 | -m68010 | -m68020 | -m68030 | -m68040'
`| -m68302 | -m68331 | -m68332 | -m68333 | -m68340 | -mcpu32'
     Specify what processor in the 68000 family is the target.  The
     default is normally the 68020, but this can be changed at
     configuration time.

`-m68881 | -m68882 | -mno-68881 | -mno-68882'
     The target machine does (or does not) have a floating-point
     coprocessor.  The default is to assume a coprocessor for 68020,
     68030, and cpu32.  Although the basic 68000 is not compatible with
     the 68881, a combination of the two can be specified, since it's
     possible to do emulation of the coprocessor instructions with the
     main processor.

`-m68851 | -mno-68851'
     The target machine does (or does not) have a memory-management
     unit coprocessor.  The default is to assume an MMU for 68020 and
     up.

   The following options are available when `as' is configured for the
SPARC architecture:

`-Av6 | -Av7 | -Av8 | -Asparclite'
     Explicitly select a variant of the SPARC architecture.

`-bump'
     Warn when the assembler switches to another architecture.

* Menu:

* Manual::                      Structure of this Manual
* GNU Assembler::               as, the GNU Assembler
* Object Formats::              Object File Formats
* Command Line::                Command Line
* Input Files::                 Input Files
* Object::                      Output (Object) File
* Errors::                      Error and Warning Messages


File: as,  Node: Manual,  Next: GNU Assembler,  Up: Overview

Structure of this Manual
========================

   This manual is intended to describe what you need to know to use GNU
`as'.  We cover the syntax expected in source files, including notation
for symbols, constants, and expressions; the directives that `as'
understands; and of course how to invoke `as'.

   This manual also describes some of the machine-dependent features of
various flavors of the assembler.

   On the other hand, this manual is *not* intended as an introduction
to programming in assembly language--let alone programming in general!
In a similar vein, we make no attempt to introduce the machine
architecture; we do *not* describe the instruction set, standard
mnemonics, registers or addressing modes that are standard to a
particular architecture.  You may want to consult the manufacturer's
machine architecture manual for this information.


File: as,  Node: GNU Assembler,  Next: Object Formats,  Prev: Manual,  Up: Overview

as, the GNU Assembler
=====================

   GNU `as' is really a family of assemblers.  If you use (or have
used) the GNU assembler on one architecture, you should find a fairly
similar environment when you use it on another architecture.  Each
version has much in common with the others, including object file
formats, most assembler directives (often called "pseudo-ops") and
assembler syntax.

   `as' is primarily intended to assemble the output of the GNU C
compiler `gcc' for use by the linker `ld'.  Nevertheless, we've tried
to make `as' assemble correctly everything that other assemblers for
the same machine would assemble.  Any exceptions are documented
explicitly (*note Machine Dependencies::.).  This doesn't mean `as'
always uses the same syntax as another assembler for the same
architecture; for example, we know of several incompatible versions of
680x0 assembly language syntax.

   Unlike older assemblers, `as' is designed to assemble a source
program in one pass of the source file.  This has a subtle impact on the
`.org' directive (*note `.org': Org.).


File: as,  Node: Object Formats,  Next: Command Line,  Prev: GNU Assembler,  Up: Overview

Object File Formats
===================

   The GNU assembler can be configured to produce several alternative
object file formats.  For the most part, this does not affect how you
write assembly language programs; but directives for debugging symbols
are typically different in different file formats.  *Note Symbol
Attributes: Symbol Attributes.


File: as,  Node: Command Line,  Next: Input Files,  Prev: Object Formats,  Up: Overview

Command Line
============

   After the program name `as', the command line may contain options
and file names.  Options may appear in any order, and may be before,
after, or between file names.  The order of file names is significant.

   `--' (two hyphens) by itself names the standard input file
explicitly, as one of the files for `as' to assemble.

   Except for `--' any command line argument that begins with a hyphen
(`-') is an option.  Each option changes the behavior of `as'.  No
option changes the way another option works.  An option is a `-'
followed by one or more letters; the case of the letter is important.
All options are optional.

   Some options expect exactly one file name to follow them.  The file
name may either immediately follow the option's letter (compatible with
older assemblers) or it may be the next command argument (GNU
standard).  These two command lines are equivalent:

     as -o my-object-file.o mumble.s
     as -omy-object-file.o mumble.s


File: as,  Node: Input Files,  Next: Object,  Prev: Command Line,  Up: Overview

Input Files
===========

   We use the phrase "source program", abbreviated "source", to
describe the program input to one run of `as'.  The program may be in
one or more files; how the source is partitioned into files doesn't
change the meaning of the source.

   The source program is a concatenation of the text in all the files,
in the order specified.

   Each time you run `as' it assembles exactly one source program.  The
source program is made up of one or more files.  (The standard input is
also a file.)

   You give `as' a command line that has zero or more input file names.
The input files are read (from left file name to right).  A command
line argument (in any position) that has no special meaning is taken to
be an input file name.

   If you give `as' no file names it attempts to read one input file
from the `as' standard input, which is normally your terminal.  You may
have to type ctl-D to tell `as' there is no more program to assemble.

   Use `--' if you need to explicitly name the standard input file in
your command line.

   If the source is empty, `as' will produce a small, empty object file.

Filenames and Line-numbers
--------------------------

   There are two ways of locating a line in the input file (or files)
and either may be used in reporting error messages.  One way refers to
a line number in a physical file; the other refers to a line number in a
"logical" file.  *Note Error and Warning Messages: Errors.

   "Physical files" are those files named in the command line given to
`as'.

   "Logical files" are simply names declared explicitly by assembler
directives; they bear no relation to physical files.  Logical file names
help error messages reflect the original source file, when `as' source
is itself synthesized from other files.  *Note `.app-file': App-File.


File: as,  Node: Object,  Next: Errors,  Prev: Input Files,  Up: Overview

Output (Object) File
====================

   Every time you run `as' it produces an output file, which is your
assembly language program translated into numbers.  This file is the
object file, named `b.out', if `as' is configured for the Intel 80960,
or unless you tell `as' to give it another name by using the `-o'
option.  Conventionally, object file names end with `.o'.  The default
name of `a.out' is used for historical reasons:  older assemblers were
capable of assembling self-contained programs directly into a runnable
program.  (For some formats, this isn't currently possible, but it can
be done for `a.out' format.)

   The object file is meant for input to the linker `ld'.  It contains
assembled program code, information to help `ld' integrate the
assembled program into a runnable file, and (optionally) symbolic
information for the debugger.


File: as,  Node: Errors,  Prev: Object,  Up: Overview

Error and Warning Messages
==========================

   `as' may write warnings and error messages to the standard error
file (usually your terminal).  This should not happen when  a compiler
runs `as' automatically.  Warnings report an assumption made so that
`as' could keep assembling a flawed program; errors report a grave
problem that stops the assembly.

   Warning messages have the format

     file_name:NNN:Warning Message Text

(where NNN is a line number).  If a logical file name has been given
(*note `.app-file': App-File.) it is used for the filename, otherwise
the name of the current input file is used.  If a logical line number
was given (*note `.line': Line.) 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 tradition).

   Error messages have the format
     file_name:NNN:FATAL:Error Message Text
   The file name and line number are derived as for warning messages.
The actual message text may be rather less explanatory because many of
them aren't supposed to happen.


File: as,  Node: Invoking,  Next: Syntax,  Prev: Overview,  Up: Top

Command-Line Options
********************

   This chapter describes command-line options available in *all*
versions of the GNU assembler; *note Machine Dependencies::., for
options specific to particular machine architectures.

   If you are invoking `as' via the GNU C compiler (version 2), you can
use the `-Wa' option to pass arguments through to the assembler.  The
assembler arguments must be separated from each other (and the `-Wa')
by commas.  For example:

     gcc -c -g -O -Wa,-alh,-L file.c

   will cause a listing to be emitted to standard output with high-level
and assembly source.

   Many compiler command-line options, such as `-R' and many
machine-specific options, will be automatically be passed to the
assembler by the compiler, so usually you do not need to use this `-Wa'
mechanism.

* Menu:

* a::             -a[dhlns] enable listings
* D::             -D for compatibility
* f::             -f to work faster
* I::             -I for .include search path

* K::             -K for difference tables

* L::             -L to retain local labels
* o::             -o to name the object file
* R::             -R to join data and text sections
* v::             -v to announce version
* W::             -W to suppress warnings


File: as,  Node: a,  Next: D,  Up: Invoking

Enable Listings: `-a[dhlns]'
============================

   These options enable listing output from the assembler.  By itself,
`-a' requests high-level, assembly, and symbols listing.  Other letters
may be used to select specific options for the list: `-ah' requests a
high-level language listing, `-al' requests an output-program assembly
listing, and `-as' requests a symbol table listing.  High-level
listings require that a compiler debugging option like `-g' be used,
and that assembly listings (`-al') be requested also.

   The `-ad' option may be used to omit debugging pseudo-ops from the
listing.

   Once you have specified one of these options, you can further control
listing output and its appearance using the directives `.list',
`.nolist', `.psize', `.eject', `.title', and `.sbttl'.  The `-an'
option turns off all forms processing.  If you do not request listing
output with one of the `-a' options, the listing-control directives
have no effect.

   The letters after `-a' may be combined into one option, *e.g.*,
`-aln'.


File: as,  Node: D,  Next: f,  Prev: a,  Up: Invoking

`-D'
====

   This option has no effect whatsoever, but it is accepted to make it
more likely that scripts written for other assemblers will also work
with `as'.


File: as,  Node: f,  Next: I,  Prev: D,  Up: Invoking

Work Faster: `-f'
=================

   `-f' should only be used when assembling programs written by a
(trusted) compiler.  `-f' stops the assembler from doing whitespace and
comment pre-processing on the input file(s) before assembling them.
*Note Pre-processing: Pre-processing.

     *Warning:* if the files actually need to be pre-processed (if they
     contain comments, for example), `as' will not work correctly if
     `-f' is used.


File: as,  Node: I,  Next: K,  Prev: f,  Up: Invoking

`.include' search path: `-I' PATH
=================================

   Use this option to add a PATH to the list of directories `as' will
search for files specified in `.include' directives (*note `.include':
Include.).  You may use `-I' as many times as necessary to include a
variety of paths.  The current working directory is always searched
first; after that, `as' searches any `-I' directories in the same order
as they were specified (left to right) on the command line.


File: as,  Node: K,  Next: L,  Prev: I,  Up: Invoking

Difference Tables: `-K'
=======================

   `as' sometimes alters the code emitted for directives of the form
`.word SYM1-SYM2'; *note `.word': Word..  You can use the `-K' option
if you want a warning issued when this is done.


File: as,  Node: L,  Next: o,  Prev: K,  Up: Invoking

Include Local Labels: `-L'
==========================

   Labels beginning with `L' (upper case only) are called "local
labels". *Note Symbol Names::.  Normally you don't 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 `as' and `ld' discard such labels, so you don't normally
debug with them.

   This option tells `as' to retain those `L...' symbols in the object
file.  Usually if you do this you also tell the linker `ld' to preserve
symbols whose names begin with `L'.


File: as,  Node: o,  Next: R,  Prev: L,  Up: Invoking

Name the Object File: `-o'
==========================

   There is always one object file output when you run `as'.  By
default it has the name `a.out' (or `b.out', for Intel 960 targets
only).  You use this option (which takes exactly one filename) to give
the object file a different name.

   Whatever the object file is called, `as' will overwrite any existing
file of the same name.


File: as,  Node: R,  Next: v,  Prev: o,  Up: Invoking

Join Data and Text Sections: `-R'
=================================

   `-R' tells `as' to write the object file as if all data-section data
lives in the text section.  This is only done at the very last moment:
your binary data are the same, but data section parts are relocated
differently.  The data section part of your object file is zero bytes
long because all its bytes are appended to the text section.  (*Note
Sections and Relocation: Sections.)

   When you specify `-R' it would be possible to generate shorter
address displacements (because we don't have to cross between text and
data section).  We refrain from doing this simply for compatibility with
older versions of `as'.  In future, `-R' may work this way.

   When `as' is configured for COFF output, this option is only useful
if you use sections named `.text' and `.data'.


File: as,  Node: v,  Next: W,  Prev: R,  Up: Invoking

Announce Version: `-v'
======================

   You can find out what version of as is running by including the
option `-v' (which you can also spell as `-version') on the command
line.


File: as,  Node: W,  Prev: v,  Up: Invoking

Suppress Warnings: `-W'
=======================

   `as' should never give a warning or error message when assembling
compiler output.  But programs written by people often cause `as' to
give a warning that a particular assumption was made.  All such
warnings are directed to the standard error file.  If you use this
option, no warnings are issued.  This option only affects the warning
messages: it does not change any particular of how `as' assembles your
file.  Errors, which stop the assembly, are still reported.


File: as,  Node: Syntax,  Next: Sections,  Prev: Invoking,  Up: Top

Syntax
******

   This chapter describes the machine-independent syntax allowed in a
source file.  `as' syntax is similar to what many other assemblers use;
it is inspired by the BSD 4.2 assembler, except that `as' does not
assemble Vax bit-fields.

* Menu:

* Pre-processing::              Pre-processing
* Whitespace::                  Whitespace
* Comments::                    Comments
* Symbol Intro::                Symbols
* Statements::                  Statements
* Constants::                   Constants


File: as,  Node: Pre-processing,  Next: Whitespace,  Up: Syntax

Pre-Processing
==============

   The `as' internal pre-processor:
   * adjusts and removes extra whitespace.  It leaves one space or tab
     before the keywords on a line, and turns any other whitespace on
     the line into a single space.

   * removes all comments, replacing them with a single space, or an
     appropriate number of newlines.

   * converts character constants into the appropriate numeric values.

   Note that it does not do macro processing, include file handling, or
anything else you may get from your C compiler's pre-processor.  You can
do include file processing with the `.include' directive (*note
`.include': Include.).  Other "CPP" style pre-processing can be done
with the GNU C compiler, by giving the input file a `.S' suffix; see
the compiler documentation for details.

   Excess whitespace, comments, and character constants cannot be used
in the portions of the input text that are not pre-processed.

   If the first line of an input file is `#NO_APP' or the `-f' option
is given, the input file will not be pre-processed.  Within such an
input file, parts of the file can be pre-processed by putting a line
that says `#APP' before the text that should be pre-processed, and
putting a line that says `#NO_APP' after them.  This feature is mainly
intend to support `asm' statements in compilers whose output normally
does not need to be pre-processed.


File: as,  Node: Whitespace,  Next: Comments,  Prev: Pre-processing,  Up: Syntax

Whitespace
==========

   "Whitespace" is one or more blanks or tabs, in any order.
Whitespace is used to separate symbols, and to make programs neater for
people to read.  Unless within character constants (*note Character
Constants: Characters.), any whitespace means the same as exactly one
space.


File: as,  Node: Comments,  Next: Symbol Intro,  Prev: Whitespace,  Up: Syntax

Comments
========

   There are two ways of rendering comments to `as'.  In both cases the
comment is equivalent to one space.

   Anything from `/*' through the next `*/' is a comment.  This means
you may not nest these comments.

     /*
       The only way to include a newline ('\n') in a comment
       is to use this sort of comment.
     */

     /* This sort of comment does not nest. */

   Anything from the "line comment" character to the next newline is
considered a comment and is ignored.  The line comment character is `#'
on the Vax; `#' on the i960; `!' on the SPARC; `|' on the 680x0; `;'
for the AMD 29K family; `;' for the H8/300 family; `!' for the H8/500
family; `!' for the Hitachi SH; `!' for the Z8000; see *Note Machine
Dependencies::.

   On some machines there are two different line comment characters.
One will only begin a comment if it is the first non-whitespace
character on a line, while the other will always begin a comment.

   To be compatible with past assemblers, a special interpretation is
given to lines that begin with `#'.  Following the `#' an absolute
expression (*note Expressions::.) is expected:  this will be the
logical line number of the next line.  Then a string (*Note 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,
the line is ignored.  (Just like a comment.)
                               # This is an ordinary comment.
     # 42-6 "new_file_name"    # New logical file name
                               # This is logical line # 36.
   This feature is deprecated, and may disappear from future versions
of `as'.


File: as,  Node: Symbol Intro,  Next: Statements,  Prev: Comments,  Up: Syntax

Symbols
=======

   A "symbol" is one or more characters chosen from the set of all
letters (both upper and lower case), digits and the three characters
`_.$'.  On most machines, you can also use `$' in symbol names;
exceptions are noted in *Note Machine Dependencies::.  No symbol may
begin with a digit.  Case is significant.  There is no length limit:
all characters are significant.  Symbols are delimited by characters
not in that set, or by the beginning of a file (since the source
program must end with a newline, the end of a file is not a possible
symbol delimiter).  *Note Symbols::.


File: as,  Node: Statements,  Next: Constants,  Prev: Symbol Intro,  Up: Syntax

Statements
==========

   A "statement" ends at a newline character (`\n') or line separator
character.  (The line separator is usually `;', unless this conflicts
with the comment character; *note Machine Dependencies::..)  The
newline or separator character is considered part of the preceding
statement.  Newlines and separators within character constants are an
exception: they don't end statements.

   It is an error to end any statement with end-of-file:  the last
character of any input file should be a newline.

   You may write a statement on more than one line if you put a
backslash (`\') immediately in front of any newlines within the
statement.  When `as' reads a backslashed newline both characters are
ignored.  You can even put backslashed newlines in the middle of symbol
names without changing the meaning of your source program.

   An empty statement is allowed, and may include whitespace.  It is
ignored.

   A statement begins with zero or more labels, optionally followed by a
key symbol which determines what kind of statement it is.  The key
symbol determines the syntax of the rest of the statement.  If the
symbol begins with a dot `.' then the statement is an assembler
directive: typically valid for any computer.  If the symbol begins with
a letter the statement is an assembly language "instruction": it will
assemble into a machine language instruction.  Different versions of
`as' for different computers will recognize different instructions.  In
fact, the same symbol may represent a different instruction in a
different computer's assembly language.

   A label is a symbol immediately followed by a colon (`:').
Whitespace before a label or after a colon is permitted, but you may not
have whitespace between a label's symbol and its colon. *Note Labels::.

     label:     .directive    followed by something
     another_label:           # This is an empty statement.
                instruction   operand_1, operand_2, ...


File: as,  Node: Constants,  Prev: Statements,  Up: Syntax

Constants
=========

   A constant is a number, written so that its value is known by
inspection, without knowing any context.  Like this:
     .byte  74, 0112, 092, 0x4A, 0X4a, 'J, '\J # All the same value.
     .ascii "Ring the bell\7"                  # A string constant.
     .octa  0x123456789abcdef0123456789ABCDEF0 # A bignum.
     .float 0f-314159265358979323846264338327\
     95028841971.693993751E-40                 # - pi, a flonum.

* Menu:

* Characters::                  Character Constants
* Numbers::                     Number Constants


File: as,  Node: Characters,  Next: Numbers,  Up: Constants

Character Constants
-------------------

   There are two kinds of character constants.  A "character" stands
for one character in one byte and its value may be used in numeric
expressions.  String constants (properly called string *literals*) are
potentially many bytes and their values may not be used in arithmetic
expressions.

* Menu:

* Strings::                     Strings
* Chars::                       Characters


File: as,  Node: Strings,  Next: Chars,  Up: Characters

Strings
.......

   A "string" is written between double-quotes.  It may contain
double-quotes or null characters.  The way to get special characters
into a string is to "escape" these characters: precede them with a
backslash `\' character.  For example `\\' represents one backslash:
the first `\' is an escape which tells `as' to interpret the second
character literally as a backslash (which prevents `as' from
recognizing the second `\' as an escape character).  The complete list
of escapes follows.

`\b'
     Mnemonic for backspace; for ASCII this is octal code 010.

`\f'
     Mnemonic for FormFeed; for ASCII this is octal code 014.

`\n'
     Mnemonic for newline; for ASCII this is octal code 012.

`\r'
     Mnemonic for carriage-Return; for ASCII this is octal code 015.

`\t'
     Mnemonic for horizontal Tab; for ASCII this is octal code 011.

`\ DIGIT DIGIT DIGIT'
     An octal character code.  The numeric code is 3 octal digits.  For
     compatibility with other Unix systems, 8 and 9 are accepted as
     digits: for example, `\008' has the value 010, and `\009' the
     value 011.

`\\'
     Represents one `\' character.

`\"'
     Represents one `"' character.  Needed in strings to represent this
     character, because an unescaped `"' would end the string.

`\ ANYTHING-ELSE'
     Any other character when escaped by `\' will give a warning, but
     assemble as if the `\' was not present.  The idea is that if you
     used an escape sequence you clearly didn't want the literal
     interpretation of the following character.  However `as' has no
     other interpretation, so `as' knows it is giving you the wrong
     code and warns you of the fact.

   Which characters are escapable, and what those escapes represent,
varies widely among assemblers.  The current set is what we think the
BSD 4.2 assembler recognizes, and is a subset of what most C compilers
recognize.  If you are in doubt, don't use an escape sequence.


File: as,  Node: Chars,  Prev: Strings,  Up: Characters

Characters
..........

   A single character may be written as a single quote immediately
followed by that character.  The same escapes apply to characters as to
strings.  So if you want to write the character backslash, you must
write `'\\' where the first `\' escapes the second `\'.  As you can
see, the quote is an acute accent, not a grave accent.  A newline
immediately following an acute accent is taken as a literal character
and does not count as the end of a statement.  The value of a character
constant in a numeric expression is the machine's byte-wide code for
that character.  `as' assumes your character code is ASCII: `'A' means
65, `'B' means 66, and so on.


File: as,  Node: Numbers,  Prev: Characters,  Up: Constants

Number Constants
----------------

   `as' distinguishes three kinds of numbers according to how they are
stored in the target machine.  *Integers* are numbers that would fit
into an `int' in the C language.  *Bignums* are integers, but they are
stored in more than 32 bits.  *Flonums* are floating point numbers,
described below.

* Menu:

* Integers::                    Integers
* Bignums::                     Bignums
* Flonums::                     Flonums


File: as,  Node: Integers,  Next: Bignums,  Up: Numbers

Integers
........

   A binary integer is `0b' or `0B' followed by zero or more of the
binary digits `01'.

   An octal integer is `0' followed by zero or more of the octal digits
(`01234567').

   A decimal integer starts with a non-zero digit followed by zero or
more digits (`0123456789').

   A hexadecimal integer is `0x' or `0X' followed by one or more
hexadecimal digits chosen from `0123456789abcdefABCDEF'.

   Integers have the usual values.  To denote a negative integer, use
the prefix operator `-' discussed under expressions (*note Prefix
Operators: Prefix Ops.).


File: as,  Node: Bignums,  Next: Flonums,  Prev: Integers,  Up: Numbers

Bignums
.......

   A "bignum" has the same syntax and semantics as an integer except
that the number (or its negative) takes more than 32 bits to represent
in binary.  The distinction is made because in some places integers are
permitted while bignums are not.


File: as,  Node: Flonums,  Prev: Bignums,  Up: Numbers

Flonums
.......

   A "flonum" represents a floating point number.  The translation is
indirect: a decimal floating point number from the text is converted by
`as' to a generic binary floating point number of more than sufficient
precision.  This generic floating point number is converted to a
particular computer's floating point format (or formats) by a portion
of `as' specialized to that computer.

   A flonum is written by writing (in order)
   * The digit `0'.

   * A letter, to tell `as' the rest of the number is a flonum.  `e' is
     recommended.  Case is not important.

     On the H8/300, H8/500, Hitachi SH, and AMD 29K architectures, the
     letter must be one of the letters `DFPRSX' (in upper or lower
     case).

     On the Intel 960 architecture, the letter must be one of the
     letters `DFT' (in upper or lower case).

   * An optional sign: either `+' or `-'.

   * An optional "integer part": zero or more decimal digits.

   * An optional "fractional part": `.' followed by zero or more
     decimal digits.

   * An optional exponent, consisting of:

        * An `E' or `e'.

        * Optional sign: either `+' or `-'.

        * One or more decimal digits.

   At least one of the integer part or the fractional part must be
present.  The floating point number has the usual base-10 value.

   `as' does all processing using integers.  Flonums are computed
independently of any floating point hardware in the computer running
`as'.


File: as,  Node: Sections,  Next: Symbols,  Prev: Syntax,  Up: Top

Sections and Relocation
***********************

* Menu:

* Secs Background::             Background
* Ld Sections::                 ld Sections
* As Sections::                 as Internal Sections
* Sub-Sections::                Sub-Sections
* bss::                         bss Section


File: as,  Node: Secs Background,  Next: Ld Sections,  Up: Sections

Background
==========

   Roughly, a section is a range of addresses, with no gaps; all data
"in" those addresses is treated the same for some particular purpose.
For example there may be a "read only" section.

   The linker `ld' reads many object files (partial programs) and
combines their contents to form a runnable program.  When `as' emits an
object file, the partial program is assumed to start at address 0.
`ld' will assign the final addresses the partial program occupies, so
that different partial programs don't overlap.  This is actually an
over-simplification, but it will suffice to explain how `as' uses
sections.

   `ld' moves blocks of bytes of your program to their run-time
addresses.  These blocks slide to their run-time addresses as rigid
units; their length does not change and neither does the order of bytes
within them.  Such a rigid unit is called a *section*.  Assigning
run-time addresses to sections is called "relocation".  It includes the
task of adjusting mentions of object-file addresses so they refer to
the proper run-time addresses.  For the H8/300 and H8/500, and for the
Hitachi SH, `as' pads sections if needed to ensure they end on a word
(sixteen bit) boundary.

   An object file written by `as' has at least three sections, any of
which may be empty.  These are named "text", "data" and "bss" sections.

   When it generates COFF output, `as' can also generate whatever other
named sections you specify using the `.section' directive (*note
`.section': Section.).  If you don't use any directives that place
output in the `.text' or `.data' sections, these sections will still
exist, but will be empty.

   Within the object file, the text section starts at address `0', the
data section follows, and the bss section follows the data section.

   To let `ld' know which data will change when the sections are
relocated, and how to change that data, `as' also writes to the object
file details of the relocation needed.  To perform relocation `ld' must
know, each time an address in the object file is mentioned:
   * Where in the object file is the beginning of this reference to an
     address?

   * How long (in bytes) is this reference?

   * Which section does the address refer to?  What is the numeric
     value of
          (ADDRESS) - (START-ADDRESS OF SECTION)?

   * Is the reference to an address "Program-Counter relative"?

   In fact, every address `as' ever uses is expressed as
     (SECTION) + (OFFSET INTO SECTION)

Further, every expression `as' computes is of this section-relative
nature.  "Absolute expression" means an expression with section
"absolute" (*note Ld Sections::.).  A "pass1 expression" means an
expression with section "pass1" (*note as Internal Sections: As
Sections.).  In this manual we use the notation {SECNAME N} to mean
"offset N into section SECNAME".

   Apart from text, data and bss sections you need to know about the
"absolute" section.  When `ld' mixes partial programs, addresses in the
absolute section remain unchanged.  For example, address `{absolute 0}'
is "relocated" to run-time address 0 by `ld'.  Although two partial
programs' data sections will not overlap addresses after linking, *by
definition* their absolute sections will overlap.  Address `{absolute
239}' in one partial program will always be the same address when the
program is running as address `{absolute 239}' in any other partial
program.

   The idea of sections is extended to the "undefined" section.  Any
address whose section is unknown at assembly time is by definition
rendered {undefined U}--where U will be filled in later.  Since numbers
are always defined, the only way to generate an undefined address is to
mention an undefined symbol.  A reference to a named common block would
be such a symbol: its value is unknown at assembly time so it has
section *undefined*.

   By analogy the word *section* is used to describe groups of sections
in the linked program.  `ld' puts all partial programs' text sections
in contiguous addresses in the linked program.  It is customary to
refer to the *text section* of a program, meaning all the addresses of
all partial program's text sections.  Likewise for data and bss
sections.

   Some sections are manipulated by `ld'; others are invented for use
of `as' and have no meaning except during assembly.


File: as,  Node: Ld Sections,  Next: As Sections,  Prev: Secs Background,  Up: Sections

ld Sections
===========

   `ld' deals with just four kinds of sections, summarized below.

*named sections*
*text section*
*data section*
     These sections hold your program.  `as' and `ld' treat them as
     separate but equal sections.  Anything you can say of one section
     is true another.  When the program is running, however, it is
     customary for the text section to be unalterable.  The text
     section is often shared among processes: it will contain
     instructions, constants and the like.  The data section of a
     running program is usually alterable: for example, C variables
     would be stored in the data section.

*bss section*
     This section contains zeroed bytes when your program begins
     running.  It is used to hold unitialized variables or common
     storage.  The length of each partial program's bss section is
     important, but because it starts out containing zeroed bytes there
     is no need to store explicit zero bytes in the object file.  The
     bss section was invented to eliminate those explicit zeros from
     object files.

*absolute section*
     Address 0 of this section is always "relocated" to runtime address
     0.  This is useful if you want to refer to an address that `ld'
     must not change when relocating.  In this sense we speak of
     absolute addresses being "unrelocatable": they don't change during
     relocation.

*undefined section*
     This "section" is a catch-all for address references to objects
     not in the preceding sections.

   An idealized example of three relocatable sections follows.  The
example uses the traditional section names `.text' and `.data'.  Memory
addresses are on the horizontal axis.

                           +-----+----+--+
     partial program # 1:  |ttttt|dddd|00|
                           +-----+----+--+

                           text   data bss
                           seg.   seg. seg.

                           +---+---+---+
     partial program # 2:  |TTT|DDD|000|
                           +---+---+---+

                           +--+---+-----+--+----+---+-----+~~
     linked program:       |  |TTT|ttttt|  |dddd|DDD|00000|
                           +--+---+-----+--+----+---+-----+~~

         addresses:        0 ...


File: as,  Node: As Sections,  Next: Sub-Sections,  Prev: Ld Sections,  Up: Sections

as Internal Sections
====================

   These sections are meant only for the internal use of `as'.  They
have no meaning at run-time.  You don't really need to know about these
sections for most purposes; but they can be mentioned in `as' warning
messages, so it might be helpful to have an idea of their meanings to
`as'.  These sections are used to permit the value of every expression
in your assembly language program to be a section-relative address.

ASSEMBLER-INTERNAL-LOGIC-ERROR!
     An internal assembler logic error has been found.  This means
     there is a bug in the assembler.

expr section
     The assembler stores complex expression internally as combinations
     of symbols.  When it needs to represent an expression as a symbol,
     it puts it in the expr section.


File: as,  Node: Sub-Sections,  Next: bss,  Prev: As Sections,  Up: Sections

Sub-Sections
============

   Assembled bytes conventionally fall into two sections: text and data.
You may have separate groups of data in named sections that you want to
end up near to each other in the object file, even though they are not
contiguous in the assembler source.  `as' allows you to use
"subsections" for this purpose.  Within each section, there can be
numbered subsections with values from 0 to 8192.  Objects assembled
into the same subsection will be grouped with other objects in the same
subsection when they are all put into the object file.  For example, a
compiler might want to store constants in the text section, but might
not want to have them interspersed with the program being assembled.
In this case, the compiler could issue a `.text 0' before each section
of code being output, and a `.text 1' before each group of constants
being output.

   Subsections are optional.  If you don't use subsections, everything
will be stored in subsection number zero.

   Each subsection is zero-padded up to a multiple of four bytes.
(Subsections may be padded a different amount on different flavors of
`as'.)

   Subsections appear in your object file in numeric order, lowest
numbered to highest.  (All this to be compatible with other people's
assemblers.) The object file contains no representation of subsections;
`ld' and other programs that manipulate object files will see no trace
of them.  They just see all your text subsections as a text section,
and all your data subsections as a data section.

   To specify which subsection you want subsequent statements assembled
into, use a numeric argument to specify it, in a `.text EXPRESSION' or
a `.data EXPRESSION' statement.  When generating COFF output, you can
also use an extra subsection argument with arbitrary named sections:
`.section NAME, EXPRESSION'.  EXPRESSION should be an absolute
expression.  (*Note Expressions::.)  If you just say `.text' then
`.text 0' is assumed.  Likewise `.data' means `.data 0'.  Assembly
begins in `text 0'.  For instance:
     .text 0     # The default subsection is text 0 anyway.
     .ascii "This lives in the first text subsection. *"
     .text 1
     .ascii "But this lives in the second text subsection."
     .data 0
     .ascii "This lives in the data section,"
     .ascii "in the first data subsection."
     .text 0
     .ascii "This lives in the first text section,"
     .ascii "immediately following the asterisk (*)."

   Each section has a "location counter" incremented by one for every
byte assembled into that section.  Because subsections are merely a
convenience restricted to `as' there is no concept of a subsection
location counter.  There is no way to directly manipulate a location
counter--but the `.align' directive will change it, and any label
definition will capture its current value.  The location counter of the
section that statements are being assembled into is said to be the
"active" location counter.


File: as,  Node: bss,  Prev: Sub-Sections,  Up: Sections

bss Section
===========

   The bss section is used for local common variable storage.  You may
allocate address space in the bss section, but you may not dictate data
to load into it before your program executes.  When your program starts
running, all the contents of the bss section are zeroed bytes.

   Addresses in the bss section are allocated with special directives;
you may not assemble anything directly into the bss section.  Hence
there are no bss subsections. *Note `.comm': Comm, *note `.lcomm':
Lcomm..


File: as,  Node: Symbols,  Next: Expressions,  Prev: Sections,  Up: Top

Symbols
*******

   Symbols are a central concept: the programmer uses symbols to name
things, the linker uses symbols to link, and the debugger uses symbols
to debug.

     *Warning:* `as' does not place symbols in the object file in the
     same order they were declared.  This may break some debuggers.

* Menu:

* Labels::                      Labels
* Setting Symbols::             Giving Symbols Other Values
* Symbol Names::                Symbol Names
* Dot::                         The Special Dot Symbol
* Symbol Attributes::           Symbol Attributes


File: as,  Node: Labels,  Next: Setting Symbols,  Up: Symbols

Labels
======

   A "label" is written as a symbol immediately followed by a colon
`:'.  The symbol then represents the current value of the active
location counter, and is, for example, a suitable instruction operand.
You are warned if you use the same symbol to represent two different
locations: the first definition overrides any other definitions.


File: as,  Node: Setting Symbols,  Next: Symbol Names,  Prev: Labels,  Up: Symbols

Giving Symbols Other Values
===========================

   A symbol can be given an arbitrary value by writing a symbol,
followed by an equals sign `=', followed by an expression (*note
Expressions::.).  This is equivalent to using the `.set' directive.
*Note `.set': Set.


File: as,  Node: Symbol Names,  Next: Dot,  Prev: Setting Symbols,  Up: Symbols

Symbol Names
============

   Symbol names begin with a letter or with one of `._'.  On most
machines, you can also use `$' in symbol names; exceptions are noted in
*Note Machine Dependencies::.  That character may be followed by any
string of digits, letters, dollar signs (unless otherwise noted in
*Note Machine Dependencies::), and underscores.  For the AMD 29K
family, `?' is also allowed in the body of a symbol name, though not at
its beginning.

   Case of letters is significant: `foo' is a different symbol name
than `Foo'.

   Each symbol has exactly one name. Each name in an assembly language
program refers to exactly one symbol. You may use that symbol name any
number of times in a program.

Local Symbol Names
------------------

   Local symbols help compilers and programmers use names temporarily.
There are ten local symbol names, which are re-used throughout the
program.  You may refer to them using the names `0' `1' ... `9'.  To
define a local symbol, write a label of the form `N:' (where N
represents any digit).  To refer to the most recent previous definition
of that symbol write `Nb', using the same digit as when you defined the
label.  To refer to the next definition of a local label, write
`Nf'--where N gives you a choice of 10 forward references.  The `b'
stands for "backwards" and the `f' stands for "forwards".

   Local symbols are not emitted by the current GNU C compiler.

   There is no restriction on how you can use these labels, but
remember that at any point in the assembly you can refer to at most 10
prior local labels and to at most 10 forward local labels.

   Local symbol names are only a notation 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 have these
parts:

`L'
     All local labels begin with `L'. Normally both `as' and `ld'
     forget symbols that start with `L'. These labels are used for
     symbols you are never intended to see.  If you give the `-L'
     option then `as' will retain these symbols in the object file. If
     you also instruct `ld' to retain these symbols, you may use them
     in debugging.

`DIGIT'
     If the label is written `0:' then the digit is `0'.  If the label
     is written `1:' then the digit is `1'.  And so on up through `9:'.


A'
     This unusual character is included so you don't accidentally invent
     a symbol of the same name.  The character has ASCII value `\001'.

`*ordinal number*'
     This is a serial number to keep the labels distinct.  The first
     `0:' gets the number `1'; The 15th `0:' gets the number `15';
     *etc.*.  Likewise for the other labels `1:' through `9:'.

   For instance, the first `1:' is named `L
A1', the 44th `3:' is named
`L
A44'.


File: as,  Node: Dot,  Next: Symbol Attributes,  Prev: Symbol Names,  Up: Symbols

The Special Dot Symbol
======================

   The special symbol `.' refers to the current address that `as' is
assembling into.  Thus, the expression `melvin: .long .' will cause
`melvin' to contain its own address.  Assigning a value to `.' is
treated the same as a `.org' directive.  Thus, the expression `.=.+4'
is the same as saying `.space 4'.


File: as,  Node: Symbol Attributes,  Prev: Dot,  Up: Symbols

Symbol Attributes
=================

   Every symbol has, as well as its name, the attributes "Value" and
"Type".  Depending on output format, symbols can also have auxiliary
attributes.

   If you use a symbol without defining it, `as' assumes zero for all
these attributes, and probably won't warn you.  This makes the symbol
an externally defined symbol, which is generally what you would want.

* Menu:

* Symbol Value::                Value
* Symbol Type::                 Type


* a.out Symbols::               Symbol Attributes: `a.out'

* COFF Symbols::                Symbol Attributes for COFF


File: as,  Node: Symbol Value,  Next: Symbol Type,  Up: Symbol Attributes

Value
-----

   The value of a symbol is (usually) 32 bits.  For a symbol which
labels a location in the text, data, bss or absolute sections the value
is the number of addresses from the start of that section to the label.
Naturally for text, data and bss sections the value of a symbol changes
as `ld' changes section base addresses during linking.  Absolute
symbols' values do not change during linking: that is why they are
called absolute.

   The value of an undefined symbol is treated in a special way.  If it
is 0 then the symbol is not defined in this assembler source program,
and `ld' will try to determine its value from other programs it is
linked with.  You make this kind of symbol simply by mentioning a symbol
name without defining it.  A non-zero value represents a `.comm' common
declaration.  The value is how much common storage to reserve, in bytes
(addresses).  The symbol refers to the first address of the allocated
storage.


File: as,  Node: Symbol Type,  Next: a.out Symbols,  Prev: Symbol Value,  Up: Symbol Attributes

Type
----

   The type attribute of a symbol contains relocation (section)
information, any flag settings indicating that a symbol is external, and
(optionally), other information for linkers and debuggers.  The exact
format depends on the object-code output format in use.


File: as,  Node: a.out Symbols,  Next: COFF Symbols,  Prev: Symbol Type,  Up: Symbol Attributes

Symbol Attributes: `a.out'
--------------------------

* Menu:

* Symbol Desc::                 Descriptor
* Symbol Other::                Other


File: as,  Node: Symbol Desc,  Next: Symbol Other,  Up: a.out Symbols

Descriptor
..........

   This is an arbitrary 16-bit value.  You may establish a symbol's
descriptor value by using a `.desc' statement (*note `.desc': Desc.).
A descriptor value means nothing to `as'.


File: as,  Node: Symbol Other,  Prev: Symbol Desc,  Up: a.out Symbols

Other
.....

   This is an arbitrary 8-bit value.  It means nothing to `as'.


File: as,  Node: COFF Symbols,  Prev: a.out Symbols,  Up: Symbol Attributes

Symbol Attributes for COFF
--------------------------

   The COFF format supports a multitude of auxiliary symbol attributes;
like the primary symbol attributes, they are set between `.def' and
`.endef' directives.

Primary Attributes
..................

   The symbol name is set with `.def'; the value and type,
respectively, with `.val' and `.type'.

Auxiliary Attributes
....................

   The `as' directives `.dim', `.line', `.scl', `.size', and `.tag' can
generate auxiliary symbol table information for COFF.


File: as,  Node: Expressions,  Next: Pseudo Ops,  Prev: Symbols,  Up: Top

Expressions
***********

   An "expression" specifies an address or numeric value.  Whitespace
may precede and/or follow an expression.

* Menu:

* Empty Exprs::                 Empty Expressions
* Integer Exprs::               Integer Expressions


File: as,  Node: Empty Exprs,  Next: Integer Exprs,  Up: Expressions

Empty Expressions
=================

   An empty expression has no value: it is just whitespace or null.
Wherever an absolute expression is required, you may omit the
expression and `as' will assume a value of (absolute) 0.  This is
compatible with other assemblers.


File: as,  Node: Integer Exprs,  Prev: Empty Exprs,  Up: Expressions

Integer Expressions
===================

   An "integer expression" is one or more *arguments* delimited by
*operators*.

* Menu:

* Arguments::                   Arguments
* Operators::                   Operators
* Prefix Ops::                  Prefix Operators
* Infix Ops::                   Infix Operators


File: as,  Node: Arguments,  Next: Operators,  Up: Integer Exprs

Arguments
---------

   "Arguments" are symbols, numbers or subexpressions.  In other
contexts arguments are sometimes called "arithmetic operands".  In this
manual, to avoid confusing them with the "instruction operands" of the
machine language, we use the term "argument" to refer to parts of
expressions only, reserving the word "operand" to refer only to machine
instruction operands.

   Symbols are evaluated to yield {SECTION NNN} where SECTION is one of
text, data, bss, absolute, or undefined.  NNN is a signed, 2's
complement 32 bit integer.

   Numbers are usually integers.

   A number can be a flonum or bignum.  In this case, you are warned
that only the low order 32 bits are used, and `as' pretends these 32
bits are an integer.  You may write integer-manipulating instructions
that act on exotic constants, compatible with other assemblers.

   Subexpressions are a left parenthesis `(' followed by an integer
expression, followed by a right parenthesis `)'; or a prefix operator
followed by an argument.


File: as,  Node: Operators,  Next: Prefix Ops,  Prev: Arguments,  Up: Integer Exprs

Operators
---------

   "Operators" are arithmetic functions, like `+' or `%'.  Prefix
operators are followed by an argument.  Infix operators appear between
their arguments.  Operators may be preceded and/or followed by
whitespace.


File: as,  Node: Prefix Ops,  Next: Infix Ops,  Prev: Operators,  Up: Integer Exprs

Prefix Operator
---------------

   `as' has the following "prefix operators".  They each take one
argument, which must be absolute.

`-'
     "Negation".  Two's complement negation.

`~'
     "Complementation".  Bitwise not.


File: as,  Node: Infix Ops,  Prev: Prefix Ops,  Up: Integer Exprs

Infix Operators
---------------

   "Infix operators" take two arguments, one on either side.  Operators
have precedence, but operations with equal precedence are performed left
to right.  Apart from `+' or `-', both arguments must be absolute, and
the result is absolute.

  1. Highest Precedence

    `*'
          "Multiplication".

    `/'
          "Division".  Truncation is the same as the C operator `/'

    `%'
          "Remainder".

    `<'
    `<<'
          "Shift Left".  Same as the C operator `<<'.

    `>'
    `>>'
          "Shift Right".  Same as the C operator `>>'.

  2. Intermediate precedence

    `|'
          "Bitwise Inclusive Or".

    `&'
          "Bitwise And".

    `^'
          "Bitwise Exclusive Or".

    `!'
          "Bitwise Or Not".

  3. Lowest Precedence

    `+'
          "Addition".  If either argument is absolute, the result has
          the section of the other argument.  If either argument is
          pass1 or undefined, the result is pass1.  Otherwise `+' is
          illegal.

    `-'
          "Subtraction".  If the right argument is absolute, the result
          has the section of the left argument.  If either argument is
          pass1 the result is pass1.  If either argument is undefined
          the result is difference section.  If both arguments are in
          the same section, the result is absolute--provided that
          section is one of text, data or bss.  Otherwise subtraction
          is illegal.

   The sense of the rule for addition is that it's only meaningful to
add the *offsets* in an address; you can only have a defined section in
one of the two arguments.

   Similarly, you can't subtract quantities from two different sections.


File: as,  Node: Pseudo Ops,  Next: Machine Dependencies,  Prev: Expressions,  Up: Top

Assembler Directives
********************

   All assembler directives have names that begin with a period (`.').
The rest of the name is letters, usually in lower case.

   This chapter discusses directives that are available regardless of
the target machine configuration for the GNU assembler.  Some machine
configurations provide additional directives.  *Note Machine
Dependencies::.

* Menu:

* Abort::                       `.abort'

* ABORT::                       `.ABORT'

* Align::                       `.align ABS-EXPR , ABS-EXPR'
* App-File::                    `.app-file STRING'
* Ascii::                       `.ascii "STRING"'...
* Asciz::                       `.asciz "STRING"'...
* Byte::                        `.byte EXPRESSIONS'
* Comm::                        `.comm SYMBOL , LENGTH '
* Data::                        `.data SUBSECTION'

* Def::                         `.def NAME'

* Desc::                        `.desc SYMBOL, ABS-EXPRESSION'

* Dim::                         `.dim'

* Double::                      `.double FLONUMS'
* Eject::                       `.eject'
* Else::                        `.else'

* Endef::                       `.endef'

* Endif::                       `.endif'
* Equ::                         `.equ SYMBOL, EXPRESSION'
* Extern::                      `.extern'

* File::                        `.file STRING'

* Fill::                        `.fill REPEAT , SIZE , VALUE'
* Float::                       `.float FLONUMS'
* Global::                      `.global SYMBOL', `.globl SYMBOL'
* hword::                       `.hword EXPRESSIONS'
* Ident::                       `.ident'
* If::                          `.if ABSOLUTE EXPRESSION'
* Include::                     `.include "FILE"'
* Int::                         `.int EXPRESSIONS'
* Lcomm::                       `.lcomm SYMBOL , LENGTH'
* Lflags::                      `.lflags'

* Line::                        `.line LINE-NUMBER'

* Ln::                          `.ln LINE-NUMBER'
* List::                        `.list'
* Long::                        `.long EXPRESSIONS'

* Nolist::                      `.nolist'
* Octa::                        `.octa BIGNUMS'
* Org::                         `.org NEW-LC , FILL'
* Psize::                       `.psize LINES, COLUMNS'
* Quad::                        `.quad BIGNUMS'
* Sbttl::                       `.sbttl "SUBHEADING"'

* Scl::                         `.scl CLASS'

* Section::                     `.section NAME, SUBSECTION'

* Set::                         `.set SYMBOL, EXPRESSION'
* Short::                       `.short EXPRESSIONS'
* Single::                      `.single FLONUMS'

* Size::                        `.size'

* Space::                       `.space SIZE , FILL'

* Stab::                        `.stabd, .stabn, .stabs'

* Tag::                         `.tag STRUCTNAME'

* Text::                        `.text SUBSECTION'
* Title::                       `.title "HEADING"'

* Type::                        `.type INT'
* Val::                         `.val ADDR'

* Word::                        `.word EXPRESSIONS'
* Deprecated::                  Deprecated Directives


File: as,  Node: Abort,  Next: ABORT,  Up: Pseudo Ops

`.abort'
========

   This directive stops the assembly immediately.  It is for
compatibility with other assemblers.  The original idea was that the
assembly language source would be piped into the assembler.  If the
sender of the source quit, it could use this directive tells `as' to
quit also.  One day `.abort' will not be supported.


File: as,  Node: ABORT,  Next: Align,  Prev: Abort,  Up: Pseudo Ops

`.ABORT'
========

   When producing COFF output, `as' accepts this directive as a synonym
for `.abort'.

   When producing `b.out' output, `as' accepts this directive, but
ignores it.


File: as,  Node: Align,  Next: App-File,  Prev: ABORT,  Up: Pseudo Ops

`.align ABS-EXPR , ABS-EXPR'
============================

   Pad the location counter (in the current subsection) to a particular
storage boundary.  The first expression (which must be absolute) is the
number of low-order zero bits the location counter will have after
advancement.  For example `.align 3' will advance the location counter
until it a multiple of 8.  If the location counter is already a
multiple of 8, no change is needed.

   The second expression (also absolute) gives the value to be stored in
the padding bytes.  It (and the comma) may be omitted.  If it is
omitted, the padding bytes are zero.


File: as,  Node: App-File,  Next: Ascii,  Prev: Align,  Up: Pseudo Ops

`.app-file STRING'
==================

   `.app-file' (which may also be spelled `.file') tells `as' that we
are about to start a new logical file.  STRING is the new file name.
In general, the filename is recognized whether or not it is surrounded
by quotes `"'; but if you wish to specify an empty file name is
permitted, you must give the quotes-`""'.  This statement may go away in
future: it is only recognized to be compatible with old `as' programs.


File: as,  Node: Ascii,  Next: Asciz,  Prev: App-File,  Up: Pseudo Ops

`.ascii "STRING"'...
====================

   `.ascii' expects zero or more string literals (*note Strings::.)
separated by commas.  It assembles each string (with no automatic
trailing zero byte) into consecutive addresses.


File: as,  Node: Asciz,  Next: Byte,  Prev: Ascii,  Up: Pseudo Ops

`.asciz "STRING"'...
====================

   `.asciz' is just like `.ascii', but each string is followed by a
zero byte.  The "z" in `.asciz' stands for "zero".


File: as,  Node: Byte,  Next: Comm,  Prev: Asciz,  Up: Pseudo Ops

`.byte EXPRESSIONS'
===================

   `.byte' expects zero or more expressions, separated by commas.  Each
expression is assembled into the next byte.


File: as,  Node: Comm,  Next: Data,  Prev: Byte,  Up: Pseudo Ops

`.comm SYMBOL , LENGTH '
========================

   `.comm' declares a named common area in the bss section.  Normally
`ld' reserves memory addresses for it during linking, so no partial
program defines the location of the symbol.  Use `.comm' to tell `ld'
that it must be at least LENGTH bytes long.  `ld' will allocate space
for each `.comm' symbol that is at least as long as the longest `.comm'
request in any of the partial programs linked.  LENGTH is an absolute
expression.


File: as,  Node: Data,  Next: Def,  Prev: Comm,  Up: Pseudo Ops

`.data SUBSECTION'
==================

   `.data' tells `as' to assemble the following statements onto the end
of the data subsection numbered SUBSECTION (which is an absolute
expression).  If SUBSECTION is omitted, it defaults to zero.


File: as,  Node: Def,  Next: Desc,  Prev: Data,  Up: Pseudo Ops

`.def NAME'
===========

   Begin defining debugging information for a symbol NAME; the
definition extends until the `.endef' directive is encountered.

   This directive is only observed when `as' is configured for COFF
format output; when producing `b.out', `.def' is recognized, but
ignored.


File: as,  Node: Desc,  Next: Dim,  Prev: Def,  Up: Pseudo Ops

`.desc SYMBOL, ABS-EXPRESSION'
==============================

   This directive sets the descriptor of the symbol (*note Symbol
Attributes::.) to the low 16 bits of an absolute expression.

   The `.desc' directive is not available when `as' is configured for
COFF output; it is only for `a.out' or `b.out' object format.  For the
sake of compatibility, `as' will accept it, but produce no output, when
configured for COFF.


File: as,  Node: Dim,  Next: Double,  Prev: Desc,  Up: Pseudo Ops

`.dim'
======

   This directive is generated by compilers to include auxiliary
debugging information in the symbol table.  It is only permitted inside
`.def'/`.endef' pairs.

   `.dim' is only meaningful when generating COFF format output; when
`as' is generating `b.out', it accepts this directive but ignores it.


File: as,  Node: Double,  Next: Eject,  Prev: Dim,  Up: Pseudo Ops

`.double FLONUMS'
=================

   `.double' expects zero or more flonums, separated by commas.  It
assembles floating point numbers.  The exact kind of floating point
numbers emitted depends on how `as' is configured.  *Note Machine
Dependencies::.


File: as,  Node: Eject,  Next: Else,  Prev: Double,  Up: Pseudo Ops

`.eject'
========

   Force a page break at this point, when generating assembly listings.


File: as,  Node: Else,  Next: Endef,  Prev: Eject,  Up: Pseudo Ops

`.else'
=======

   `.else' is part of the `as' support for conditional assembly; *note
`.if': If..  It marks the beginning of a section of code to be
assembled if the condition for the preceding `.if' was false.


File: as,  Node: Endef,  Next: Endif,  Prev: Else,  Up: Pseudo Ops

`.endef'
========

   This directive flags the end of a symbol definition begun with
`.def'.

   `.endef' is only meaningful when generating COFF format output; if
`as' is configured to generate `b.out', it accepts this directive but
ignores it.


File: as,  Node: Endif,  Next: Equ,  Prev: Endef,  Up: Pseudo Ops

`.endif'
========

   `.endif' is part of the `as' support for conditional assembly; it
marks the end of a block of code that is only assembled conditionally.
*Note `.if': If.


File: as,  Node: Equ,  Next: Extern,  Prev: Endif,  Up: Pseudo Ops

`.equ SYMBOL, EXPRESSION'
=========================

   This directive sets the value of SYMBOL to EXPRESSION.  It is
synonymous with `.set'; *note `.set': Set..


File: as,  Node: Extern,  Next: File,  Prev: Equ,  Up: Pseudo Ops

`.extern'
=========

   `.extern' is accepted in the source program--for compatibility with
other assemblers--but it is ignored.  `as' treats all undefined symbols
as external.


File: as,  Node: File,  Next: Fill,  Prev: Extern,  Up: Pseudo Ops

`.file STRING'
==============

   `.file' (which may also be spelled `.app-file') tells `as' that we
are about to start a new logical file.  STRING is the new file name.
In general, the filename is recognized whether or not it is surrounded
by quotes `"'; but if you wish to specify an empty file name, you must
give the quotes-`""'.  This statement may go away in future: it is only
recognized to be compatible with old `as' programs.  In some
configurations of `as', `.file' has already been removed to avoid
conflicts with other assemblers.  *Note Machine Dependencies::.


File: as,  Node: Fill,  Next: Float,  Prev: File,  Up: Pseudo Ops

`.fill REPEAT , SIZE , VALUE'
=============================

   RESULT, SIZE and VALUE are absolute expressions.  This emits REPEAT
copies of SIZE bytes.  REPEAT may be zero or more.  SIZE may be zero or
more, but if it is more than 8, then it is deemed to have the value 8,
compatible with other people's assemblers.  The contents of each REPEAT
bytes is taken from an 8-byte number.  The highest order 4 bytes are
zero.  The lowest order 4 bytes are VALUE rendered in the byte-order of
an integer on the computer `as' is assembling for.  Each SIZE bytes in
a repetition is taken from the lowest order SIZE bytes of this number.
Again, this bizarre behavior is compatible with other people's
assemblers.

   SIZE and VALUE are optional.  If the second comma and VALUE are
absent, VALUE is assumed zero.  If the first comma and following tokens
are absent, SIZE is assumed to be 1.


File: as,  Node: Float,  Next: Global,  Prev: Fill,  Up: Pseudo Ops

`.float FLONUMS'
================

   This directive assembles zero or more flonums, separated by commas.
It has the same effect as `.single'.  The exact kind of floating point
numbers emitted depends on how `as' is configured.  *Note Machine
Dependencies::.


File: as,  Node: Global,  Next: hword,  Prev: Float,  Up: Pseudo Ops

`.global SYMBOL', `.globl SYMBOL'
=================================

   `.global' makes the symbol visible to `ld'.  If you define SYMBOL in
your partial program, its value is made available to other partial
programs that are linked with it.  Otherwise, SYMBOL will take its
attributes from a symbol of the same name from another partial program
it is linked with.

   Both spellings (`.globl' and `.global') are accepted, for
compatibility with other assemblers.


File: as,  Node: hword,  Next: Ident,  Prev: Global,  Up: Pseudo Ops

`.hword EXPRESSIONS'
====================

   This expects zero or more EXPRESSIONS, and emits a 16 bit number for
each.

   This directive is a synonym for `.short'; depending on the target
architecture, it may also be a synonym for `.word'.


File: as,  Node: Ident,  Next: If,  Prev: hword,  Up: Pseudo Ops

`.ident'
========

   This directive is used by some assemblers to place tags in object
files.  `as' simply accepts the directive for source-file compatibility
with such assemblers, but does not actually emit anything for it.


File: as,  Node: If,  Next: Include,  Prev: Ident,  Up: Pseudo Ops

`.if ABSOLUTE EXPRESSION'
=========================

   `.if' marks the beginning of a section of code which is only
considered part of the source program being assembled if the argument
(which must be an ABSOLUTE EXPRESSION) is non-zero.  The end of the
conditional section of code must be marked by `.endif' (*note `.endif':
Endif.); optionally, you may include code for the alternative
condition, flagged by `.else' (*note `.else': Else..

   The following variants of `.if' are also supported:
`.ifdef SYMBOL'
     Assembles the following section of code if the specified SYMBOL
     has been defined.

`.ifndef SYMBOL'
`ifnotdef SYMBOL'
     Assembles the following section of code if the specified SYMBOL
     has not been defined.  Both spelling variants are equivalent.


File: as,  Node: Include,  Next: Int,  Prev: If,  Up: Pseudo Ops

`.include "FILE"'
=================

   This directive provides a way to include supporting files at
specified points in your source program.  The code from FILE is
assembled as if it followed the point of the `.include'; when the end
of the included file is reached, assembly of the original file
continues.  You can control the search paths used with the `-I'
command-line option (*note Command-Line Options: Invoking.).  Quotation
marks are required around FILE.


File: as,  Node: Int,  Next: Lcomm,  Prev: Include,  Up: Pseudo Ops

`.int EXPRESSIONS'
==================

   Expect zero or more EXPRESSIONS, of any section, separated by
commas.  For each expression, emit a 32-bit number that will, at run
time, be the value of that expression.  The byte order of the
expression depends on what kind of computer will run the program.


File: as,  Node: Lcomm,  Next: Lflags,  Prev: Int,  Up: Pseudo Ops

`.lcomm SYMBOL , LENGTH'
========================

   Reserve LENGTH (an absolute expression) bytes for a local common
denoted by SYMBOL.  The section and value of SYMBOL are those of the
new local common.  The addresses are allocated in the bss section, so
at run-time the bytes will start off zeroed.  SYMBOL is not declared
global (*note `.global': Global.), so is normally not visible to `ld'.


File: as,  Node: Lflags,  Next: Line,  Prev: Lcomm,  Up: Pseudo Ops

`.lflags'
=========

   `as' accepts this directive, for compatibility with other
assemblers, but ignores it.


File: as,  Node: Line,  Next: Ln,  Prev: Lflags,  Up: Pseudo Ops

`.line LINE-NUMBER'
===================

   Tell `as' to change the logical line number.  LINE-NUMBER must be an
absolute expression.  The next line will have that logical line number.
So any other statements on the current line (after a statement
separator character) will be reported as on logical line number
LINE-NUMBER - 1.  One day this directive will be unsupported: it is
used only for compatibility with existing assembler programs.

   *Warning:* In the AMD29K configuration of as, this command is only
available with the name `.ln', rather than as either `.line' or `.ln'.

   Even though this is a directive associated with the `a.out' or
`b.out' object-code formats, `as' will still recognize it when
producing COFF output, and will treat `.line' as though it were the
COFF `.ln' *if* it is found outside a `.def'/`.endef' pair.

   Inside a `.def', `.line' is, instead, one of the directives used by
compilers to generate auxiliary symbol information for debugging.


File: as,  Node: Ln,  Next: List,  Prev: Line,  Up: Pseudo Ops

`.ln LINE-NUMBER'
=================

   `.ln' is a synonym for `.line'.


File: as,  Node: List,  Next: Long,  Prev: Ln,  Up: Pseudo Ops

`.list'
=======

   Control (in conjunction with the `.nolist' directive) whether or not
assembly listings are generated.  These two directives maintain an
internal counter (which is zero initially).   `.list' increments the
counter, and `.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
`-a' command line option; *note Command-Line Options: Invoking.), the
initial value of the listing counter is one.


File: as,  Node: Long,  Next: Nolist,  Prev: List,  Up: Pseudo Ops

`.long EXPRESSIONS'
===================

   `.long' is the same as `.int', *note `.int': Int..


File: as,  Node: Nolist,  Next: Octa,  Prev: Long,  Up: Pseudo Ops

`.nolist'
=========

   Control (in conjunction with the `.list' directive) whether or not
assembly listings are generated.  These two directives maintain an
internal counter (which is zero initially).   `.list' increments the
counter, and `.nolist' decrements it.  Assembly listings are generated
whenever the counter is greater than zero.


File: as,  Node: Octa,  Next: Org,  Prev: Nolist,  Up: Pseudo Ops

`.octa BIGNUMS'
===============

   This directive expects zero or more bignums, separated by commas.
For each bignum, it emits a 16-byte integer.

   The term "octa" comes from contexts in which a "word" is two bytes;
hence *octa*-word for 16 bytes.


File: as,  Node: Org,  Next: Psize,  Prev: Octa,  Up: Pseudo Ops

`.org NEW-LC , FILL'
====================

   `.org' will advance the location counter of the current section to
NEW-LC.  NEW-LC is either an absolute expression or an expression with
the same section as the current subsection.  That is, you can't use
`.org' to cross sections: if NEW-LC has the wrong section, the `.org'
directive is ignored.  To be compatible with former assemblers, if the
section of NEW-LC is absolute, `as' will issue a warning, then pretend
the section of NEW-LC is the same as the current subsection.

   `.org' may only increase the location counter, or leave it
unchanged; you cannot use `.org' to move the location counter backwards.

   Because `as' tries to assemble programs in one pass NEW-LC may not
be undefined.  If you really detest this restriction we eagerly await a
chance to share your improved assembler.

   Beware that the origin is relative to the start of the section, not
to the start of the subsection.  This is compatible with other people's
assemblers.

   When the location counter (of the current subsection) is advanced,
the intervening bytes are filled with FILL which should be an absolute
expression.  If the comma and FILL are omitted, FILL defaults to zero.


File: as,  Node: Psize,  Next: Quad,  Prev: Org,  Up: Pseudo Ops

`.psize LINES , COLUMNS'
========================

   Use this directive to declare the number of lines--and, optionally,
the number of columns--to use for each page, when generating listings.

   If you don't use `.psize', listings will use a default line-count of
60.  You may omit the comma and COLUMNS specification; the default
width is 200 columns.

   `as' will generate formfeeds whenever the specified number of lines
is exceeded (or whenever you explicitly request one, using `.eject').

   If you specify LINES as `0', no formfeeds are generated save those
explicitly specified with `.eject'.


File: as,  Node: Quad,  Next: Sbttl,  Prev: Psize,  Up: Pseudo Ops

`.quad BIGNUMS'
===============

   `.quad' expects zero or more bignums, separated by commas.  For each
bignum, it emits an 8-byte integer.  If the bignum won't fit in 8
bytes, it prints a warning message; and just takes the lowest order 8
bytes of the bignum.

   The term "quad" comes from contexts in which a "word" is two bytes;
hence *quad*-word for 8 bytes.


File: as,  Node: Sbttl,  Next: Scl,  Prev: Quad,  Up: Pseudo Ops

`.sbttl "SUBHEADING"'
=====================

   Use SUBHEADING as the title (third line, immediately after the title
line) when generating assembly listings.

   This directive affects subsequent pages, as well as the current page
if it appears within ten lines of the top of a page.


File: as,  Node: Scl,  Next: Section,  Prev: Sbttl,  Up: Pseudo Ops

`.scl CLASS'
============

   Set the storage-class value for a symbol.  This directive may only be
used inside a `.def'/`.endef' pair.  Storage class may flag whether a
symbol is static or external, or it may record further symbolic
debugging information.

   The `.scl' directive is primarily associated with COFF output; when
configured to generate `b.out' output format, `as' will accept this
directive but ignore it.


File: as,  Node: Section,  Next: Set,  Prev: Scl,  Up: Pseudo Ops

`.section NAME, SUBSECTION'
===========================

   Assemble the following code into end of subsection numbered
SUBSECTION in the COFF named section NAME.  If you omit SUBSECTION,
`as' uses subsection number zero.  `.section .text' is equivalent to
the `.text' directive; `.section .data' is equivalent to the `.data'
directive.


File: as,  Node: Set,  Next: Short,  Prev: Section,  Up: Pseudo Ops

`.set SYMBOL, EXPRESSION'
=========================

   This directive sets the value of SYMBOL to EXPRESSION.  This will
change SYMBOL's value and type to conform to EXPRESSION.  If SYMBOL was
flagged as external, it remains flagged. (*Note Symbol Attributes::.)

   You may `.set' a symbol many times in the same assembly.  If the
expression's section is unknowable during pass 1, a second pass over
the source program will be forced.  The second pass is currently not
implemented.  `as' will abort with an error message if one is required.

   If you `.set' a global symbol, the value stored in the object file
is the last value stored into it.


File: as,  Node: Short,  Next: Single,  Prev: Set,  Up: Pseudo Ops

`.short EXPRESSIONS'
====================

   `.short' is normally the same as `.word'.  *Note `.word': Word.

   In some configurations, however, `.short' and `.word' generate
numbers of different lengths; *note Machine Dependencies::..


File: as,  Node: Single,  Next: Size,  Prev: Short,  Up: Pseudo Ops

`.single FLONUMS'
=================

   This directive assembles zero or more flonums, separated by commas.
It has the same effect as `.float'.  The exact kind of floating point
numbers emitted depends on how `as' is configured.  *Note Machine
Dependencies::.


File: as,  Node: Size,  Next: Space,  Prev: Single,  Up: Pseudo Ops

`.size'
=======

   This directive is generated by compilers to include auxiliary
debugging information in the symbol table.  It is only permitted inside
`.def'/`.endef' pairs.

   `.size' is only meaningful when generating COFF format output; when
`as' is generating `b.out', it accepts this directive but ignores it.


File: as,  Node: Space,  Next: Stab,  Prev: Size,  Up: Pseudo Ops

`.space SIZE , FILL'
====================

   This directive emits SIZE bytes, each of value FILL.  Both SIZE and
FILL are absolute expressions.  If the comma and FILL are omitted, FILL
is assumed to be zero.

   On the AMD 29K, this directive is ignored; it is accepted for
compatibility with other AMD 29K assemblers.

     *Warning:* In most versions of the GNU assembler, the directive
     `.space' has the effect of `.block'  *Note Machine Dependencies::.


File: as,  Node: Stab,  Next: Tag,  Prev: Space,  Up: Pseudo Ops

`.stabd, .stabn, .stabs'
========================

   There are three directives that begin `.stab'.  All emit symbols
(*note Symbols::.), for use by symbolic debuggers.  The symbols are not
entered in the `as' hash table: they cannot be referenced elsewhere in
the source file.  Up to five fields are required:

STRING
     This is the symbol's name.  It may contain any character except
     `\000', so is more general than ordinary symbol names.  Some
     debuggers used to code arbitrarily complex structures into symbol
     names using this field.

TYPE
     An absolute expression.  The symbol's type is set to the low 8
     bits of this expression.  Any bit pattern is permitted, but `ld'
     and debuggers will choke on silly bit patterns.

OTHER
     An absolute expression.  The symbol's "other" attribute is set to
     the low 8 bits of this expression.

DESC
     An absolute expression.  The symbol's descriptor is set to the low
     16 bits of this expression.

VALUE
     An absolute expression which becomes the symbol's value.

   If a warning is detected while reading a `.stabd', `.stabn', or
`.stabs' statement, the symbol has probably already been created and
you will get a half-formed symbol in your object file.  This is
compatible with earlier assemblers!

`.stabd TYPE , OTHER , DESC'
     The "name" of the symbol generated is not even an empty string.
     It is a null pointer, for compatibility.  Older assemblers used a
     null pointer so they didn't waste space in object files with empty
     strings.

     The symbol's value is set to the location counter, relocatably.
     When your program is linked, the value of this symbol will be
     where the location counter was when the `.stabd' was assembled.

`.stabn TYPE , OTHER , DESC , VALUE'
     The name of the symbol is set to the empty string `""'.

`.stabs STRING ,  TYPE , OTHER , DESC , VALUE'
     All five fields are specified.


File: as,  Node: Tag,  Next: Text,  Prev: Stab,  Up: Pseudo Ops

`.tag STRUCTNAME'
=================

   This directive is generated by compilers to include auxiliary
debugging information in the symbol table.  It is only permitted inside
`.def'/`.endef' pairs.  Tags are used to link structure definitions in
the symbol table with instances of those structures.

   `.tag' is only used when generating COFF format output; when `as' is
generating `b.out', it accepts this directive but ignores it.


File: as,  Node: Text,  Next: Title,  Prev: Tag,  Up: Pseudo Ops

`.text SUBSECTION'
==================

   Tells `as' to assemble the following statements onto the end of the
text subsection numbered SUBSECTION, which is an absolute expression.
If SUBSECTION is omitted, subsection number zero is used.


File: as,  Node: Title,  Next: Type,  Prev: Text,  Up: Pseudo Ops

`.title "HEADING"'
==================

   Use HEADING as the title (second line, immediately after the source
file name and pagenumber) when generating assembly listings.

   This directive affects subsequent pages, as well as the current page
if it appears within ten lines of the top of a page.


File: as,  Node: Type,  Next: Val,  Prev: Title,  Up: Pseudo Ops

`.type INT'
===========

   This directive, permitted only within `.def'/`.endef' pairs, records
the integer INT as the type attribute of a symbol table entry.

   `.type' is associated only with COFF format output; when `as' is
configured for `b.out' output, it accepts this directive but ignores it.


File: as,  Node: Val,  Next: Word,  Prev: Type,  Up: Pseudo Ops

`.val ADDR'
===========

   This directive, permitted only within `.def'/`.endef' pairs, records
the address ADDR as the value attribute of a symbol table entry.

   `.val' is used only for COFF output; when `as' is configured for
`b.out', it accepts this directive but ignores it.


File: as,  Node: Word,  Next: Deprecated,  Prev: Val,  Up: Pseudo Ops

`.word EXPRESSIONS'
===================

   This directive expects zero or more EXPRESSIONS, of any section,
separated by commas.

   The size of the number emitted, and its byte order, depends on what
kind of computer will run the program.

     *Warning: Special Treatment to support Compilers*

   Machines with a 32-bit address space, but that do less than 32-bit
addressing, require the following special treatment.  If the machine of
interest to you does 32-bit addressing (or doesn't require it; *note
Machine Dependencies::.), you can ignore this issue.

   In order to assemble compiler output into something that will work,
`as' will occasionlly do strange things to `.word' directives.
Directives of the form `.word sym1-sym2' are often emitted by compilers
as part of jump tables.  Therefore, when `as' assembles a directive of
the form `.word sym1-sym2', and the difference between `sym1' and
`sym2' does not fit in 16 bits, `as' will create a "secondary jump
table", immediately before the next label.  This secondary jump table
will be preceded by a short-jump to the first byte after the secondary
table.  This short-jump prevents the flow of control from accidentally
falling into the new table.  Inside the table will be a long-jump to
`sym2'.  The original `.word' will contain `sym1' minus the address of
the long-jump to `sym2'.

   If there were several occurrences of `.word sym1-sym2' before the
secondary jump table, all of them will be adjusted.  If there was a
`.word sym3-sym4', that also did not fit in sixteen bits, a long-jump
to `sym4' will be included in the secondary jump table, and the `.word'
directives will be adjusted to contain `sym3' minus the address of the
long-jump to `sym4'; and so on, for as many entries in the original
jump table as necessary.


File: as,  Node: Deprecated,  Prev: Word,  Up: Pseudo Ops

Deprecated Directives
=====================

   One day these directives won't work.  They are included for
compatibility with older assemblers.
.abort
.app-file
.line

File: as,  Node: Machine Dependencies,  Next: Copying,  Prev: Pseudo Ops,  Up: Top

Machine Dependent Features
**************************

   The machine instruction sets are (almost by definition) different on
each machine where `as' runs.  Floating point representations vary as
well, and `as' often supports a few additional directives or
command-line options for compatibility with other assemblers on a
particular platform.  Finally, some versions of `as' support special
pseudo-instructions for branch optimization.

   This chapter discusses most of these differences, though it does not
include details on any machine's instruction set.  For details on that
subject, see the hardware manufacturer's manual.

* Menu:


* Vax-Dependent::               VAX Dependent Features

* AMD29K-Dependent::            AMD 29K Dependent Features

* H8/300-Dependent::            Hitachi H8/300 Dependent Features

* H8/500-Dependent::            Hitachi H8/500 Dependent Features

* SH-Dependent::                Hitachi SH Dependent Features

* i960-Dependent::              Intel 80960 Dependent Features

* M68K-Dependent::              M680x0 Dependent Features

* Sparc-Dependent::             SPARC Dependent Features

* Z8000-Dependent::             Z8000 Dependent Features

* i386-Dependent::              80386 Dependent Features


File: as,  Node: Vax-Dependent,  Next: AMD29K-Dependent,  Up: Machine Dependencies

VAX Dependent Features
======================

* Menu:

* Vax-Opts::                    VAX Command-Line Options
* VAX-float::                   VAX Floating Point
* VAX-directives::              Vax Machine Directives
* VAX-opcodes::                 VAX Opcodes
* VAX-branch::                  VAX Branch Improvement
* VAX-operands::                VAX Operands
* VAX-no::                      Not Supported on VAX


File: as,  Node: Vax-Opts,  Next: VAX-float,  Up: Vax-Dependent

VAX Command-Line Options
------------------------

   The Vax version of `as' accepts any of the following options, gives
a warning message that the option was ignored and proceeds.  These
options are for compatibility with scripts designed for other people's
assemblers.

`-D' (Debug)
`-S' (Symbol Table)
`-T' (Token Trace)
     These are obsolete options used to debug old assemblers.

`-d' (Displacement size for JUMPs)
     This option expects a number following the `-d'.  Like options
     that expect filenames, the number may immediately follow the `-d'
     (old standard) or constitute the whole of the command line
     argument that follows `-d' (GNU standard).

`-V' (Virtualize Interpass Temporary File)
     Some other assemblers use a temporary file.  This option commanded
     them to keep the information in active memory rather than in a
     disk file.  `as' always does this, so this option is redundant.

`-J' (JUMPify Longer Branches)
     Many 32-bit computers permit a variety of branch instructions to
     do the same job.  Some of these instructions are short (and fast)
     but have a limited range; others are long (and slow) but can
     branch anywhere in virtual memory.  Often there are 3 flavors of
     branch: short, medium and long.  Some other assemblers would emit
     short and medium branches, unless told by this option to emit
     short and long branches.

`-t' (Temporary File Directory)
     Some other assemblers may use a temporary file, and this option
     takes a filename being the directory to site the temporary file.
     Since `as' does not use a temporary disk file, this option makes
     no difference.  `-t' needs exactly one filename.

   The Vax version of the assembler accepts two options when compiled
for VMS.  They are `-h', and `-+'.  The `-h' option prevents `as' from
modifying the symbol-table entries for symbols that contain lowercase
characters (I think).  The `-+' option causes `as' to print warning
messages if the FILENAME part of the object file, or any symbol name is
larger than 31 characters.  The `-+' option also insertes some code
following the `_main' symbol so that the object file will be compatible
with Vax-11 "C".


File: as,  Node: VAX-float,  Next: VAX-directives,  Prev: Vax-Opts,  Up: Vax-Dependent

VAX Floating Point
------------------

   Conversion of flonums to floating point is correct, and compatible
with previous assemblers.  Rounding is towards zero if the remainder is
exactly half the least significant bit.

   `D', `F', `G' and `H' floating point formats are understood.

   Immediate floating literals (*e.g.* `S`$6.9') are rendered
correctly.  Again, rounding is towards zero in the boundary case.

   The `.float' directive produces `f' format numbers.  The `.double'
directive produces `d' format numbers.


File: as,  Node: VAX-directives,  Next: VAX-opcodes,  Prev: VAX-float,  Up: Vax-Dependent

Vax Machine Directives
----------------------

   The Vax version of the assembler supports four directives for
generating Vax floating point constants.  They are described in the
table below.

`.dfloat'
     This expects zero or more flonums, separated by commas, and
     assembles Vax `d' format 64-bit floating point constants.

`.ffloat'
     This expects zero or more flonums, separated by commas, and
     assembles Vax `f' format 32-bit floating point constants.

`.gfloat'
     This expects zero or more flonums, separated by commas, and
     assembles Vax `g' format 64-bit floating point constants.

`.hfloat'
     This expects zero or more flonums, separated by commas, and
     assembles Vax `h' format 128-bit floating point constants.


File: as,  Node: VAX-opcodes,  Next: VAX-branch,  Prev: VAX-directives,  Up: Vax-Dependent

VAX Opcodes
-----------

   All DEC mnemonics are supported.  Beware that `case...' instructions
have exactly 3 operands.  The dispatch table that follows the `case...'
instruction should be made with `.word' statements.  This is compatible
with all unix assemblers we know of.


File: as,  Node: VAX-branch,  Next: VAX-operands,  Prev: VAX-opcodes,  Up: Vax-Dependent

VAX Branch Improvement
----------------------

   Certain pseudo opcodes are permitted.  They are for branch
instructions.  They expand to the shortest branch instruction that will
reach the target.  Generally these mnemonics are made by substituting
`j' for `b' at the start of a DEC mnemonic.  This feature is included
both for compatibility and to help compilers.  If you don't need this
feature, don't use these opcodes.  Here are the mnemonics, and the code
they can expand into.

`jbsb'
     `Jsb' is already an instruction mnemonic, so we chose `jbsb'.
    (byte displacement)
          `bsbb ...'

    (word displacement)
          `bsbw ...'

    (long displacement)
          `jsb ...'

`jbr'
`jr'
     Unconditional branch.
    (byte displacement)
          `brb ...'

    (word displacement)
          `brw ...'

    (long displacement)
          `jmp ...'

`jCOND'
     COND may be any one of the conditional branches `neq', `nequ',
     `eql', `eqlu', `gtr', `geq', `lss', `gtru', `lequ', `vc', `vs',
     `gequ', `cc', `lssu', `cs'.  COND may also be one of the bit tests
     `bs', `bc', `bss', `bcs', `bsc', `bcc', `bssi', `bcci', `lbs',
     `lbc'.  NOTCOND is the opposite condition to COND.
    (byte displacement)
          `bCOND ...'

    (word displacement)
          `bNOTCOND foo ; brw ... ; foo:'

    (long displacement)
          `bNOTCOND foo ; jmp ... ; foo:'

`jacbX'
     X may be one of `b d f g h l w'.
    (word displacement)
          `OPCODE ...'

    (long displacement)
               OPCODE ..., foo ;
               brb bar ;
               foo: jmp ... ;
               bar:

`jaobYYY'
     YYY may be one of `lss leq'.

`jsobZZZ'
     ZZZ may be one of `geq gtr'.
    (byte displacement)
          `OPCODE ...'

    (word displacement)
               OPCODE ..., foo ;
               brb bar ;
               foo: brw DESTINATION ;
               bar:

    (long displacement)
               OPCODE ..., foo ;
               brb bar ;
               foo: jmp DESTINATION ;
               bar:

`aobleq'
`aoblss'
`sobgeq'
`sobgtr'
    (byte displacement)
          `OPCODE ...'

    (word displacement)
               OPCODE ..., foo ;
               brb bar ;
               foo: brw DESTINATION ;
               bar:

    (long displacement)
               OPCODE ..., foo ;
               brb bar ;
               foo: jmp DESTINATION ;
               bar:


File: as,  Node: VAX-operands,  Next: VAX-no,  Prev: VAX-branch,  Up: Vax-Dependent

VAX Operands
------------

   The immediate character is `$' for Unix compatibility, not `#' as
DEC writes it.

   The indirect character is `*' for Unix compatibility, not `@' as DEC
writes it.

   The displacement sizing character is ``' (an accent grave) for Unix
compatibility, not `^' as DEC writes it.  The letter preceding ``' may
have either case.  `G' is not understood, but all other letters (`b i l
s w') are understood.

   Register names understood are `r0 r1 r2 ... r15 ap fp sp pc'.  Any
case of letters will do.

   For instance
     tstb *w`$4(r5)

   Any expression is permitted in an operand.  Operands are comma
separated.


File: as,  Node: VAX-no,  Prev: VAX-operands,  Up: Vax-Dependent

Not Supported on VAX
--------------------

   Vax bit fields can not be assembled with `as'.  Someone can add the
required code if they really need it.


File: as,  Node: AMD29K-Dependent,  Next: H8/300-Dependent,  Prev: Vax-Dependent,  Up: Machine Dependencies

AMD 29K Dependent Features
==========================

* Menu:

* AMD29K Options::              Options
* AMD29K Syntax::               Syntax
* AMD29K Floating Point::       Floating Point
* AMD29K Directives::           AMD 29K Machine Directives
* AMD29K Opcodes::              Opcodes


File: as,  Node: AMD29K Options,  Next: AMD29K Syntax,  Up: AMD29K-Dependent

Options
-------

   `as' has no additional command-line options for the AMD 29K family.


File: as,  Node: AMD29K Syntax,  Next: AMD29K Floating Point,  Prev: AMD29K Options,  Up: AMD29K-Dependent

Syntax
------

* Menu:

* AMD29K-Chars::                Special Characters
* AMD29K-Regs::                 Register Names


File: as,  Node: AMD29K-Chars,  Next: AMD29K-Regs,  Up: AMD29K Syntax

Special Characters
..................

   `;' is the line comment character.

   `@' can be used instead of a newline to separate statements.

   The character `?' is permitted in identifiers (but may not begin an
identifier).


File: as,  Node: AMD29K-Regs,  Prev: AMD29K-Chars,  Up: AMD29K Syntax

Register Names
..............

   General-purpose registers are represented by predefined symbols of
the form `GRNNN' (for global registers) or `LRNNN' (for local
registers), where NNN represents a number between `0' and `127',
written with no leading zeros.  The leading letters may be in either
upper or lower case; for example, `gr13' and `LR7' are both valid
register names.

   You may also refer to general-purpose registers by specifying the
register number as the result of an expression (prefixed with `%%' to
flag the expression as a register number):
     %%EXPRESSION

--where EXPRESSION must be an absolute expression evaluating to a
number between `0' and `255'.  The range [0, 127] refers to global
registers, and the range [128, 255] to local registers.

   In addition, `as' understands the following protected
special-purpose register names for the AMD 29K family:

       vab    chd    pc0
       ops    chc    pc1
       cps    rbp    pc2
       cfg    tmc    mmu
       cha    tmr    lru

   These unprotected special-purpose register names are also recognized:
       ipc    alu    fpe
       ipa    bp     inte
       ipb    fc     fps
       q      cr     exop


File: as,  Node: AMD29K Floating Point,  Next: AMD29K Directives,  Prev: AMD29K Syntax,  Up: AMD29K-Dependent

Floating Point
--------------

   The AMD 29K family uses IEEE floating-point numbers.


File: as,  Node: AMD29K Directives,  Next: AMD29K Opcodes,  Prev: AMD29K Floating Point,  Up: AMD29K-Dependent

AMD 29K Machine Directives
--------------------------

`.block SIZE , FILL'
     This directive emits SIZE bytes, each of value FILL.  Both SIZE
     and FILL are absolute expressions.  If the comma and FILL are
     omitted, FILL is assumed to be zero.

     In other versions of the GNU assembler, this directive is called
     `.space'.

`.cputype'
     This directive is ignored; it is accepted for compatibility with
     other AMD 29K assemblers.

`.file'
     This directive is ignored; it is accepted for compatibility with
     other AMD 29K assemblers.

          *Warning:* in other versions of the GNU assembler, `.file' is
          used for the directive called `.app-file' in the AMD 29K
          support.

`.line'
     This directive is ignored; it is accepted for compatibility with
     other AMD 29K assemblers.

`.sect'
     This directive is ignored; it is accepted for compatibility with
     other AMD 29K assemblers.

`.use SECTION NAME'
     Establishes the section and subsection for the following code;
     SECTION NAME may be one of `.text', `.data', `.data1', or `.lit'.
     With one of the first three SECTION NAME options, `.use' is
     equivalent to the machine directive SECTION NAME; the remaining
     case, `.use .lit', is the same as `.data 200'.


File: as,  Node: AMD29K Opcodes,  Prev: AMD29K Directives,  Up: AMD29K-Dependent

Opcodes
-------

   `as' implements all the standard AMD 29K opcodes.  No additional
pseudo-instructions are needed on this family.

   For information on the 29K machine instruction set, see `Am29000
User's Manual', Advanced Micro Devices, Inc.


File: as,  Node: H8/300-Dependent,  Next: H8/500-Dependent,  Prev: AMD29K-Dependent,  Up: Machine Dependencies

H8/300 Dependent Features
=========================

* Menu:

* H8/300 Options::              Options
* H8/300 Syntax::               Syntax
* H8/300 Floating Point::       Floating Point
* H8/300 Directives::           H8/300 Machine Directives
* H8/300 Opcodes::              Opcodes


File: as,  Node: H8/300 Options,  Next: H8/300 Syntax,  Up: H8/300-Dependent

Options
-------

   `as' has no additional command-line options for the Hitachi H8/300
family.


File: as,  Node: H8/300 Syntax,  Next: H8/300 Floating Point,  Prev: H8/300 Options,  Up: H8/300-Dependent

Syntax
------

* Menu:

* H8/300-Chars::                Special Characters
* H8/300-Regs::                 Register Names
* H8/300-Addressing::           Addressing Modes


File: as,  Node: H8/300-Chars,  Next: H8/300-Regs,  Up: H8/300 Syntax

Special Characters
..................

   `;' is the line comment character.

   `$' can be used instead of a newline to separate statements.
Therefore *you may not use `$' in symbol names* on the H8/300.


File: as,  Node: H8/300-Regs,  Next: H8/300-Addressing,  Prev: H8/300-Chars,  Up: H8/300 Syntax

Register Names
..............

   You can use predefined symbols of the form `rNh' and `rNl' to refer
to the H8/300 registers as sixteen 8-bit general-purpose registers.  N
is a digit from `0' to `7'); for instance, both `r0h' and `r7l' are
valid register names.

   You can also use the eight predefined symbols `rN' to refer to the
H8/300 registers as 16-bit registers (you must use this form for
addressing).

   On the H8/300H, you can also use the eight predefined symbols `erN'
(`er0' ... `er7') to refer to the 32-bit general purpose registers.

   The two control registers are called `pc' (program counter; a 16-bit
register, except on the H8/300H where it is 24 bits) and `ccr'
(condition code register; an 8-bit register).  `r7' is used as the
stack pointer, and can also be called `sp'.


File: as,  Node: H8/300-Addressing,  Prev: H8/300-Regs,  Up: H8/300 Syntax

Addressing Modes
................

   as understands the following addressing modes for the H8/300:
`rN'
     Register direct

`@rN'
     Register indirect

`@(D, rN)'
`@(D:16, rN)'
`@(D:24, rN)'
     Register indirect: 16-bit or 24-bit displacement D from register
     N.  (24-bit displacements are only meaningful on the H8/300H.)

`@rN+'
     Register indirect with post-increment

`@-rN'
     Register indirect with pre-decrement

``@'AA'
``@'AA:8'
``@'AA:16'
``@'AA:24'
     Absolute address `aa'.  (The address size `:24' only makes sense
     on the H8/300H.)

`#XX'
`#XX:8'
`#XX:16'
`#XX:32'
     Immediate data XX.  You may specify the `:8', `:16', or `:32' for
     clarity, if you wish; but `as' neither requires this nor uses
     it--the data size required is taken from context.

``@'`@'AA'
``@'`@'AA:8'
     Memory indirect.  You may specify the `:8' for clarity, if you
     wish; but `as' neither requires this nor uses it.


File: as,  Node: H8/300 Floating Point,  Next: H8/300 Directives,  Prev: H8/300 Syntax,  Up: H8/300-Dependent

Floating Point
--------------

   The H8/300 family has no hardware floating point, but the `.float'
directive generates IEEE floating-point numbers for compatibility with
other development tools.


File: as,  Node: H8/300 Directives,  Next: H8/300 Opcodes,  Prev: H8/300 Floating Point,  Up: H8/300-Dependent

H8/300 Machine Directives
-------------------------

   `as' has only one machine-dependent directive for the H8/300:

`.h300h'
     Recognize and emit additional instructions for the H8/300H
     variant, and also make `.int' emit 32-bit numbers rather than the
     usual (16-bit) for the H8/300 family.

   On the H8/300 family (including the H8/300H) `.word' directives
generate 16-bit numbers.


File: as,  Node: H8/300 Opcodes,  Prev: H8/300 Directives,  Up: H8/300-Dependent

Opcodes
-------

   For detailed information on the H8/300 machine instruction set, see
`H8/300 Series Programming Manual' (Hitachi ADE-602-025).  For
information specific to the H8/300H, see `H8/300H Series Programming
Manual' (Hitachi).

   `as' implements all the standard H8/300 opcodes.  No additional
pseudo-instructions are needed on this family.

   The following table summarizes the H8/300 opcodes, and their
arguments.  Entries marked `*' are opcodes used only on the H8/300H.

              Legend:
                 Rs   source register
                 Rd   destination register
                 abs  absolute address
                 imm  immediate data
              disp:N  N-bit displacement from a register
             pcrel:N  N-bit displacement relative to program counter

        add.b #imm,rd              *  andc #imm,ccr
        add.b rs,rd                   band #imm,rd
        add.w rs,rd                   band #imm,@rd
     *  add.w #imm,rd                 band #imm,@abs:8
     *  add.l rs,rd                   bra  pcrel:8
     *  add.l #imm,rd              *  bra  pcrel:16
        adds #imm,rd                  bt   pcrel:8
        addx #imm,rd               *  bt   pcrel:16
        addx rs,rd                    brn  pcrel:8
        and.b #imm,rd              *  brn  pcrel:16
        and.b rs,rd                   bf   pcrel:8
     *  and.w rs,rd                *  bf   pcrel:16
     *  and.w #imm,rd                 bhi  pcrel:8
     *  and.l #imm,rd              *  bhi  pcrel:16
     *  and.l rs,rd                   bls  pcrel:8

     *  bls  pcrel:16                 bld  #imm,rd
        bcc  pcrel:8                  bld  #imm,@rd
     *  bcc  pcrel:16                 bld  #imm,@abs:8
        bhs  pcrel:8                  bnot #imm,rd
     *  bhs  pcrel:16                 bnot #imm,@rd
        bcs  pcrel:8                  bnot #imm,@abs:8
     *  bcs  pcrel:16                 bnot rs,rd
        blo  pcrel:8                  bnot rs,@rd
     *  blo  pcrel:16                 bnot rs,@abs:8
        bne  pcrel:8                  bor  #imm,rd
     *  bne  pcrel:16                 bor  #imm,@rd
        beq  pcrel:8                  bor  #imm,@abs:8
     *  beq  pcrel:16                 bset #imm,rd
        bvc  pcrel:8                  bset #imm,@rd
     *  bvc  pcrel:16                 bset #imm,@abs:8
        bvs  pcrel:8                  bset rs,rd
     *  bvs  pcrel:16                 bset rs,@rd
        bpl  pcrel:8                  bset rs,@abs:8
     *  bpl  pcrel:16                 bsr  pcrel:8
        bmi  pcrel:8                  bsr  pcrel:16
     *  bmi  pcrel:16                 bst  #imm,rd
        bge  pcrel:8                  bst  #imm,@rd
     *  bge  pcrel:16                 bst  #imm,@abs:8
        blt  pcrel:8                  btst #imm,rd
     *  blt  pcrel:16                 btst #imm,@rd
        bgt  pcrel:8                  btst #imm,@abs:8
     *  bgt  pcrel:16                 btst rs,rd
        ble  pcrel:8                  btst rs,@rd
     *  ble  pcrel:16                 btst rs,@abs:8
        bclr #imm,rd                  bxor #imm,rd
        bclr #imm,@rd                 bxor #imm,@rd
        bclr #imm,@abs:8              bxor #imm,@abs:8
        bclr rs,rd                    cmp.b #imm,rd
        bclr rs,@rd                   cmp.b rs,rd
        bclr rs,@abs:8                cmp.w rs,rd
        biand #imm,rd                 cmp.w rs,rd
        biand #imm,@rd             *  cmp.w #imm,rd
        biand #imm,@abs:8          *  cmp.l #imm,rd
        bild #imm,rd               *  cmp.l rs,rd
        bild #imm,@rd                 daa  rs
        bild #imm,@abs:8              das  rs
        bior #imm,rd                  dec.b rs
        bior #imm,@rd              *  dec.w #imm,rd
        bior #imm,@abs:8           *  dec.l #imm,rd
        bist #imm,rd                  divxu.b rs,rd
        bist #imm,@rd              *  divxu.w rs,rd
        bist #imm,@abs:8           *  divxs.b rs,rd
        bixor #imm,rd              *  divxs.w rs,rd
        bixor #imm,@rd                eepmov
        bixor #imm,@abs:8          *  eepmovw

     *  exts.w rd                     mov.w rs,@abs:16
     *  exts.l rd                  *  mov.l #imm,rd
     *  extu.w rd                  *  mov.l rs,rd
     *  extu.l rd                  *  mov.l @rs,rd
        inc  rs                    *  mov.l @(disp:16,rs),rd
     *  inc.w #imm,rd              *  mov.l @(disp:24,rs),rd
     *  inc.l #imm,rd              *  mov.l @rs+,rd
        jmp  @rs                   *  mov.l @abs:16,rd
        jmp  abs                   *  mov.l @abs:24,rd
        jmp  @@abs:8               *  mov.l rs,@rd
        jsr  @rs                   *  mov.l rs,@(disp:16,rd)
        jsr  abs                   *  mov.l rs,@(disp:24,rd)
        jsr  @@abs:8               *  mov.l rs,@-rd
        ldc  #imm,ccr              *  mov.l rs,@abs:16
        ldc  rs,ccr                *  mov.l rs,@abs:24
     *  ldc  @abs:16,ccr              movfpe @abs:16,rd
     *  ldc  @abs:24,ccr              movtpe rs,@abs:16
     *  ldc  @(disp:16,rs),ccr        mulxu.b rs,rd
     *  ldc  @(disp:24,rs),ccr     *  mulxu.w rs,rd
     *  ldc  @rs+,ccr              *  mulxs.b rs,rd
     *  ldc  @rs,ccr               *  mulxs.w rs,rd
     *  mov.b @(disp:24,rs),rd        neg.b rs
     *  mov.b rs,@(disp:24,rd)     *  neg.w rs
        mov.b @abs:16,rd           *  neg.l rs
        mov.b rs,rd                   nop
        mov.b @abs:8,rd               not.b rs
        mov.b rs,@abs:8            *  not.w rs
        mov.b rs,rd                *  not.l rs
        mov.b #imm,rd                 or.b #imm,rd
        mov.b @rs,rd                  or.b rs,rd
        mov.b @(disp:16,rs),rd     *  or.w #imm,rd
        mov.b @rs+,rd              *  or.w rs,rd
        mov.b @abs:8,rd            *  or.l #imm,rd
        mov.b rs,@rd               *  or.l rs,rd
        mov.b rs,@(disp:16,rd)        orc  #imm,ccr
        mov.b rs,@-rd                 pop.w rs
        mov.b rs,@abs:8            *  pop.l rs
        mov.w rs,@rd                  push.w rs
     *  mov.w @(disp:24,rs),rd     *  push.l rs
     *  mov.w rs,@(disp:24,rd)        rotl.b rs
     *  mov.w @abs:24,rd           *  rotl.w rs
     *  mov.w rs,@abs:24           *  rotl.l rs
        mov.w rs,rd                   rotr.b rs
        mov.w #imm,rd              *  rotr.w rs
        mov.w @rs,rd               *  rotr.l rs
        mov.w @(disp:16,rs),rd        rotxl.b rs
        mov.w @rs+,rd              *  rotxl.w rs
        mov.w @abs:16,rd           *  rotxl.l rs
        mov.w rs,@(disp:16,rd)        rotxr.b rs
        mov.w rs,@-rd              *  rotxr.w rs

     *  rotxr.l rs                 *  stc  ccr,@(disp:24,rd)
        bpt                        *  stc  ccr,@-rd
        rte                        *  stc  ccr,@abs:16
        rts                        *  stc  ccr,@abs:24
        shal.b rs                     sub.b rs,rd
     *  shal.w rs                     sub.w rs,rd
     *  shal.l rs                  *  sub.w #imm,rd
        shar.b rs                  *  sub.l rs,rd
     *  shar.w rs                  *  sub.l #imm,rd
     *  shar.l rs                     subs #imm,rd
        shll.b rs                     subx #imm,rd
     *  shll.w rs                     subx rs,rd
     *  shll.l rs                  *  trapa #imm
        shlr.b rs                     xor  #imm,rd
     *  shlr.w rs                     xor  rs,rd
     *  shlr.l rs                  *  xor.w #imm,rd
        sleep                      *  xor.w rs,rd
        stc  ccr,rd                *  xor.l #imm,rd
     *  stc  ccr,@rs               *  xor.l rs,rd
     *  stc  ccr,@(disp:16,rd)        xorc #imm,ccr

   Four H8/300 instructions (`add', `cmp', `mov', `sub') are defined
with variants using the suffixes `.b', `.w', and `.l' to specify the
size of a memory operand.  `as' supports these suffixes, but does not
require them; since one of the operands is always a register, `as' can
deduce the correct size.

   For example, since `r0' refers to a 16-bit register,
     mov    r0,@foo
is equivalent to
     mov.w  r0,@foo

   If you use the size suffixes, `as' issues a warning when the suffix
and the register size do not match.


File: as,  Node: H8/500-Dependent,  Next: SH-Dependent,  Prev: H8/300-Dependent,  Up: Machine Dependencies

H8/500 Dependent Features
=========================

* Menu:

* H8/500 Options::              Options
* H8/500 Syntax::               Syntax
* H8/500 Floating Point::       Floating Point
* H8/500 Directives::           H8/500 Machine Directives
* H8/500 Opcodes::              Opcodes


File: as,  Node: H8/500 Options,  Next: H8/500 Syntax,  Up: H8/500-Dependent

Options
-------

   `as' has no additional command-line options for the Hitachi H8/500
family.


File: as,  Node: H8/500 Syntax,  Next: H8/500 Floating Point,  Prev: H8/500 Options,  Up: H8/500-Dependent

Syntax
------

* Menu:

* H8/500-Chars::                Special Characters
* H8/500-Regs::                 Register Names
* H8/500-Addressing::           Addressing Modes


File: as,  Node: H8/500-Chars,  Next: H8/500-Regs,  Up: H8/500 Syntax

Special Characters
..................

   `!' is the line comment character.

   `;' can be used instead of a newline to separate statements.

   Since `$' has no special meaning, you may use it in symbol names.


File: as,  Node: H8/500-Regs,  Next: H8/500-Addressing,  Prev: H8/500-Chars,  Up: H8/500 Syntax

Register Names
..............

   You can use the predefined symbols `r0', `r1', `r2', `r3', `r4',
`r5', `r6', and `r7' to refer to the H8/500 registers.

   The H8/500 also has these control registers:

`cp'
     code pointer

`dp'
     data pointer

`bp'
     base pointer

`tp'
     stack top pointer

`ep'
     extra pointer

`sr'
     status register

`ccr'
     condition code register

   All registers are 16 bits long.  To represent 32 bit numbers, use two
adjacent registers; for distant memory addresses, use one of the segment
pointers (`cp' for the program counter; `dp' for `r0'-`r3'; `ep' for
`r4' and `r5'; and `tp' for `r6' and `r7'.


File: as,  Node: H8/500-Addressing,  Prev: H8/500-Regs,  Up: H8/500 Syntax

Addressing Modes
................

   as understands the following addressing modes for the H8/500:
`RN'
     Register direct

`@RN'
     Register indirect

`@(d:8, RN)'
     Register indirect with 8 bit signed displacement

`@(d:16, RN)'
     Register indirect with 16 bit signed displacement

`@-RN'
     Register indirect with pre-decrement

`@RN+'
     Register indirect with post-increment

`@AA:8'
     8 bit absolute address

`@AA:16'
     16 bit absolute address

`#XX:8'
     8 bit immediate

`#XX:16'
     16 bit immediate


File: as,  Node: H8/500 Floating Point,  Next: H8/500 Directives,  Prev: H8/500 Syntax,  Up: H8/500-Dependent

Floating Point
--------------

   The H8/500 family uses IEEE floating-point numbers.


File: as,  Node: H8/500 Directives,  Next: H8/500 Opcodes,  Prev: H8/500 Floating Point,  Up: H8/500-Dependent

H8/500 Machine Directives
-------------------------

   `as' has no machine-dependent directives for the H8/500.  However,
on this platform the `.int' and `.word' directives generate 16-bit
numbers.


File: as,  Node: H8/500 Opcodes,  Prev: H8/500 Directives,  Up: H8/500-Dependent

Opcodes
-------

   For detailed information on the H8/500 machine instruction set, see
`H8/500 Series Programming Manual' (Hitachi M21T001).

   `as' implements all the standard H8/500 opcodes.  No additional
pseudo-instructions are needed on this family.

   The following table summarizes H8/500 opcodes and their operands:

     Legend:
     abs8      8-bit absolute address
     abs16     16-bit absolute address
     abs24     24-bit absolute address
     crb       `ccr', `br', `ep', `dp', `tp', `dp'
     disp8     8-bit displacement
     ea        `rn', `@rn', `@(d:8, rn)', `@(d:16, rn)',
               `@-rn', `@rn+', `@aa:8', `@aa:16',
               `#xx:8', `#xx:16'
     ea_mem    `@rn', `@(d:8, rn)', `@(d:16, rn)',
               `@-rn', `@rn+', `@aa:8', `@aa:16'
     ea_noimm  `rn', `@rn', `@(d:8, rn)', `@(d:16, rn)',
               `@-rn', `@rn+', `@aa:8', `@aa:16'
     fp        r6
     imm4      4-bit immediate data
     imm8      8-bit immediate data
     imm16     16-bit immediate data
     pcrel8    8-bit offset from program counter
     pcrel16   16-bit offset from program counter
     qim       `-2', `-1', `1', `2'
     rd        any register
     rs        a register distinct from rd
     rlist     comma-separated list of registers in parentheses;
               register ranges `rd-rs' are allowed
     sp        stack pointer (`r7')
     sr        status register
     sz        size; `.b' or `.w'.  If omitted, default `.w'

     ldc[.b] ea,crb                 bcc[.w] pcrel16
     ldc[.w] ea,sr                  bcc[.b] pcrel8
     add[:q] sz qim,ea_noimm        bhs[.w] pcrel16
     add[:g] sz ea,rd               bhs[.b] pcrel8
     adds sz ea,rd                  bcs[.w] pcrel16
     addx sz ea,rd                  bcs[.b] pcrel8
     and sz ea,rd                   blo[.w] pcrel16
     andc[.b] imm8,crb              blo[.b] pcrel8
     andc[.w] imm16,sr              bne[.w] pcrel16
     bpt                            bne[.b] pcrel8
     bra[.w] pcrel16                beq[.w] pcrel16
     bra[.b] pcrel8                 beq[.b] pcrel8
     bt[.w] pcrel16                 bvc[.w] pcrel16
     bt[.b] pcrel8                  bvc[.b] pcrel8
     brn[.w] pcrel16                bvs[.w] pcrel16
     brn[.b] pcrel8                 bvs[.b] pcrel8
     bf[.w] pcrel16                 bpl[.w] pcrel16
     bf[.b] pcrel8                  bpl[.b] pcrel8
     bhi[.w] pcrel16                bmi[.w] pcrel16
     bhi[.b] pcrel8                 bmi[.b] pcrel8
     bls[.w] pcrel16                bge[.w] pcrel16
     bls[.b] pcrel8                 bge[.b] pcrel8

     blt[.w] pcrel16                mov[:g][.b] imm8,ea_mem
     blt[.b] pcrel8                 mov[:g][.w] imm16,ea_mem
     bgt[.w] pcrel16                movfpe[.b] ea,rd
     bgt[.b] pcrel8                 movtpe[.b] rs,ea_noimm
     ble[.w] pcrel16                mulxu sz ea,rd
     ble[.b] pcrel8                 neg sz ea
     bclr sz imm4,ea_noimm          nop
     bclr sz rs,ea_noimm            not sz ea
     bnot sz imm4,ea_noimm          or sz ea,rd
     bnot sz rs,ea_noimm            orc[.b] imm8,crb
     bset sz imm4,ea_noimm          orc[.w] imm16,sr
     bset sz rs,ea_noimm            pjmp abs24
     bsr[.b] pcrel8                 pjmp @rd
     bsr[.w] pcrel16                pjsr abs24
     btst sz imm4,ea_noimm          pjsr @rd
     btst sz rs,ea_noimm            prtd imm8
     clr sz ea                      prtd imm16
     cmp[:e][.b] imm8,rd            prts
     cmp[:i][.w] imm16,rd           rotl sz ea
     cmp[:g].b imm8,ea_noimm        rotr sz ea
     cmp[:g][.w] imm16,ea_noimm     rotxl sz ea
     Cmp[:g] sz ea,rd               rotxr sz ea
     dadd rs,rd                     rtd imm8
     divxu sz ea,rd                 rtd imm16
     dsub rs,rd                     rts
     exts[.b] rd                    scb/f rs,pcrel8
     extu[.b] rd                    scb/ne rs,pcrel8
     jmp @rd                        scb/eq rs,pcrel8
     jmp @(imm8,rd)                 shal sz ea
     jmp @(imm16,rd)                shar sz ea
     jmp abs16                      shll sz ea
     jsr @rd                        shlr sz ea
     jsr @(imm8,rd)                 sleep
     jsr @(imm16,rd)                stc[.b] crb,ea_noimm
     jsr abs16                      stc[.w] sr,ea_noimm
     ldm @sp+,(rlist)               stm (rlist),@-sp
     link fp,imm8                   sub sz ea,rd
     link fp,imm16                  subs sz ea,rd
     mov[:e][.b] imm8,rd            subx sz ea,rd
     mov[:i][.w] imm16,rd           swap[.b] rd
     mov[:l][.w] abs8,rd            tas[.b] ea
     mov[:l].b abs8,rd              trapa imm4
     mov[:s][.w] rs,abs8            trap/vs
     mov[:s].b rs,abs8              tst sz ea
     mov[:f][.w] @(disp8,fp),rd     unlk fp
     mov[:f][.w] rs,@(disp8,fp)     xch[.w] rs,rd
     mov[:f].b @(disp8,fp),rd       xor sz ea,rd
     mov[:f].b rs,@(disp8,fp)       xorc.b imm8,crb
     mov[:g] sz rs,ea_mem           xorc.w imm16,sr
     mov[:g] sz ea,rd


File: as,  Node: SH-Dependent,  Next: i960-Dependent,  Prev: H8/500-Dependent,  Up: Machine Dependencies

Hitachi SH Dependent Features
=============================

* Menu:

* SH Options::              Options
* SH Syntax::               Syntax
* SH Floating Point::       Floating Point
* SH Directives::           SH Machine Directives
* SH Opcodes::              Opcodes


File: as,  Node: SH Options,  Next: SH Syntax,  Up: SH-Dependent

Options
-------

   `as' has no additional command-line options for the Hitachi SH
family.


File: as,  Node: SH Syntax,  Next: SH Floating Point,  Prev: SH Options,  Up: SH-Dependent

Syntax
------

* Menu:

* SH-Chars::                Special Characters
* SH-Regs::                 Register Names
* SH-Addressing::           Addressing Modes


File: as,  Node: SH-Chars,  Next: SH-Regs,  Up: SH Syntax

Special Characters
..................

   `!' is the line comment character.

   You can use `;' instead of a newline to separate statements.

   Since `$' has no special meaning, you may use it in symbol names.


File: as,  Node: SH-Regs,  Next: SH-Addressing,  Prev: SH-Chars,  Up: SH Syntax

Register Names
..............

   You can use the predefined symbols `r0', `r1', `r2', `r3', `r4',
`r5', `r6', `r7', `r8', `r9', `r10', `r11', `r12', `r13', `r14', and
`r15' to refer to the SH registers.

   The SH also has these control registers:

`pr'
     procedure register (holds return address)

`pc'
     program counter

`mach'
`macl'
     high and low multiply accumulator registers

`sr'
     status register

`gbr'
     global base register

`vbr'
     vector base register (for interrupt vectors)


File: as,  Node: SH-Addressing,  Prev: SH-Regs,  Up: SH Syntax

Addressing Modes
................

   `as' understands the following addressing modes for the SH.  `RN' in
the following refers to any of the numbered registers, but *not* the
control registers.

`RN'
     Register direct

`@RN'
     Register indirect

`@-RN'
     Register indirect with pre-decrement

`@RN+'
     Register indirect with post-increment

`@(DISP, RN)'
     Register indirect with displacement

`@(R0, RN)'
     Register indexed

`@(DISP, GBR)'
     `GBR' offset

`@(R0, GBR)'
     GBR indexed

`ADDR'
`@(DISP, PC)'
     PC relative address (for branch or for addressing memory).  The
     `as' implementation allows you to use the simpler form ADDR
     anywhere a PC relative address is called for; the alternate form
     is supported for compatibility with other assemblers.

`#IMM'
     Immediate data


File: as,  Node: SH Floating Point,  Next: SH Directives,  Prev: SH Syntax,  Up: SH-Dependent

Floating Point
--------------

   The SH family uses IEEE floating-point numbers.


File: as,  Node: SH Directives,  Next: SH Opcodes,  Prev: SH Floating Point,  Up: SH-Dependent

SH Machine Directives
---------------------

   `as' has no machine-dependent directives for the SH.


File: as,  Node: SH Opcodes,  Prev: SH Directives,  Up: SH-Dependent

Opcodes
-------

   For detailed information on the SH machine instruction set, see
`SH-Microcomputer User's Manual' (Hitachi Micro Systems, Inc.).

   `as' implements all the standard SH opcodes.  No additional
pseudo-instructions are needed on this family.  Note, however, that
because `as' supports a simpler form of PC-relative addressing, you may
simply write (for example)

     mov.l  bar,r0

where other assemblers might require an explicit displacement to `bar'
from the program counter:

     mov.l  @(DISP, PC)

   Here is a summary of SH opcodes:

     Legend:
     Rn        a numbered register
     Rm        another numbered register
     #imm      immediate data
     disp      displacement
     disp8     8-bit displacement
     disp12    12-bit displacement

     add #imm,Rn                    lds.l @Rn+,PR
     add Rm,Rn                      mac.w @Rm+,@Rn+
     addc Rm,Rn                     mov #imm,Rn
     addv Rm,Rn                     mov Rm,Rn
     and #imm,R0                    mov.b Rm,@(R0,Rn)
     and Rm,Rn                      mov.b Rm,@-Rn
     and.b #imm,@(R0,GBR)           mov.b Rm,@Rn
     bf disp8                       mov.b @(disp,Rm),R0
     bra disp12                     mov.b @(disp,GBR),R0
     bsr disp12                     mov.b @(R0,Rm),Rn
     bt disp8                       mov.b @Rm+,Rn
     clrm                           mov.b @Rm,Rn
     clrt                           mov.b R0,@(disp,Rm)
     cmp/eq #imm,R0                 mov.b R0,@(disp,GBR)
     cmp/eq Rm,Rn                   mov.l Rm,@(disp,Rn)
     cmp/ge Rm,Rn                   mov.l Rm,@(R0,Rn)
     cmp/gt Rm,Rn                   mov.l Rm,@-Rn
     cmp/hi Rm,Rn                   mov.l Rm,@Rn
     cmp/hs Rm,Rn                   mov.l @(disp,Rn),Rm
     cmp/pl Rn                      mov.l @(disp,GBR),R0
     cmp/pz Rn                      mov.l @(disp,PC),Rn
     cmp/str Rm,Rn                  mov.l @(R0,Rm),Rn
     div0s Rm,Rn                    mov.l @Rm+,Rn
     div0u                          mov.l @Rm,Rn
     div1 Rm,Rn                     mov.l R0,@(disp,GBR)
     exts.b Rm,Rn                   mov.w Rm,@(R0,Rn)
     exts.w Rm,Rn                   mov.w Rm,@-Rn
     extu.b Rm,Rn                   mov.w Rm,@Rn
     extu.w Rm,Rn                   mov.w @(disp,Rm),R0
     jmp @Rn                        mov.w @(disp,GBR),R0
     jsr @Rn                        mov.w @(disp,PC),Rn
     ldc Rn,GBR                     mov.w @(R0,Rm),Rn
     ldc Rn,SR                      mov.w @Rm+,Rn
     ldc Rn,VBR                     mov.w @Rm,Rn
     ldc.l @Rn+,GBR                 mov.w R0,@(disp,Rm)
     ldc.l @Rn+,SR                  mov.w R0,@(disp,GBR)
     ldc.l @Rn+,VBR                 mova @(disp,PC),R0
     lds Rn,MACH                    movt Rn
     lds Rn,MACL                    muls Rm,Rn
     lds Rn,PR                      mulu Rm,Rn
     lds.l @Rn+,MACH                neg Rm,Rn
     lds.l @Rn+,MACL                negc Rm,Rn

     nop                            stc VBR,Rn
     not Rm,Rn                      stc.l GBR,@-Rn
     or #imm,R0                     stc.l SR,@-Rn
     or Rm,Rn                       stc.l VBR,@-Rn
     or.b #imm,@(R0,GBR)            sts MACH,Rn
     rotcl Rn                       sts MACL,Rn
     rotcr Rn                       sts PR,Rn
     rotl Rn                        sts.l MACH,@-Rn
     rotr Rn                        sts.l MACL,@-Rn
     rte                            sts.l PR,@-Rn
     rts                            sub Rm,Rn
     sett                           subc Rm,Rn
     shal Rn                        subv Rm,Rn
     shar Rn                        swap.b Rm,Rn
     shll Rn                        swap.w Rm,Rn
     shll16 Rn                      tas.b @Rn
     shll2 Rn                       trapa #imm
     shll8 Rn                       tst #imm,R0
     shlr Rn                        tst Rm,Rn
     shlr16 Rn                      tst.b #imm,@(R0,GBR)
     shlr2 Rn                       xor #imm,R0
     shlr8 Rn                       xor Rm,Rn
     sleep                          xor.b #imm,@(R0,GBR)
     stc GBR,Rn                     xtrct Rm,Rn
     stc SR,Rn


File: as,  Node: i960-Dependent,  Next: M68K-Dependent,  Prev: SH-Dependent,  Up: Machine Dependencies

Intel 80960 Dependent Features
==============================

* Menu:

* Options-i960::                i960 Command-line Options
* Floating Point-i960::         Floating Point
* Directives-i960::             i960 Machine Directives
* Opcodes for i960::            i960 Opcodes


File: as,  Node: Options-i960,  Next: Floating Point-i960,  Up: i960-Dependent

i960 Command-line Options
-------------------------

`-ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC'
     Select the 80960 architecture.  Instructions or features not
     supported by the selected architecture cause fatal errors.

     `-ACA' is equivalent to `-ACA_A'; `-AKC' is equivalent to `-AMC'.
     Synonyms are provided for compatibility with other tools.

     If none of these options is specified, `as' will generate code for
     any instruction or feature that is supported by *some* version of
     the 960 (even if this means mixing architectures!).  In principle,
     `as' will attempt to deduce the minimal sufficient processor type
     if none is specified; depending on the object code format, the
     processor type may be recorded in the object file.  If it is
     critical that the `as' output match a specific architecture,
     specify that architecture explicitly.

`-b'
     Add code to collect information about conditional branches taken,
     for later optimization using branch prediction bits.  (The
     conditional branch instructions have branch prediction bits in the
     CA, CB, and CC architectures.)  If BR represents a conditional
     branch instruction, the following represents the code generated by
     the assembler when `-b' is specified:

                  call    INCREMENT ROUTINE
                  .word   0       # pre-counter
          Label:  BR
                  call    INCREMENT ROUTINE
                  .word   0       # post-counter

     The counter following a branch records the number of times that
     branch was *not* taken; the differenc between the two counters is
     the number of times the branch *was* taken.

     A table of every such `Label' is also generated, so that the
     external postprocessor `gbr960' (supplied by Intel) can locate all
     the counters.  This table is always labelled `__BRANCH_TABLE__';
     this is a local symbol to permit collecting statistics for many
     separate object files.  The table is word aligned, and begins with
     a two-word header.  The first word, initialized to 0, is used in
     maintaining linked lists of branch tables.  The second word is a
     count of the number of entries in the table, which follow
     immediately: each is a word, pointing to one of the labels
     illustrated above.

           +------------+------------+------------+ ... +------------+
           |            |            |            |     |            |
           |  *NEXT     |  COUNT: N  | *BRLAB 1   |     | *BRLAB N   |
           |            |            |            |     |            |
           +------------+------------+------------+ ... +------------+

                         __BRANCH_TABLE__ layout

     The first word of the header is used to locate multiple branch
     tables, since each object file may contain one. Normally the links
     are maintained with a call to an initialization routine, placed at
     the beginning of each function in the file.  The GNU C compiler
     will generate these calls automatically when you give it a `-b'
     option.  For further details, see the documentation of `gbr960'.

`-norelax'
     Normally, Compare-and-Branch instructions with targets that require
     displacements greater than 13 bits (or that have external targets)
     are replaced with the corresponding compare (or `chkbit') and
     branch instructions.  You can use the `-norelax' option to specify
     that `as' should generate errors instead, if the target
     displacement is larger than 13 bits.

     This option does not affect the Compare-and-Jump instructions; the
     code emitted for them is *always* adjusted when necessary
     (depending on displacement size), regardless of whether you use
     `-norelax'.


File: as,  Node: Floating Point-i960,  Next: Directives-i960,  Prev: Options-i960,  Up: i960-Dependent

Floating Point
--------------

   `as' generates IEEE floating-point numbers for the directives
`.float', `.double', `.extended', and `.single'.


File: as,  Node: Directives-i960,  Next: Opcodes for i960,  Prev: Floating Point-i960,  Up: i960-Dependent

i960 Machine Directives
-----------------------

`.bss SYMBOL, LENGTH, ALIGN'
     Reserve LENGTH bytes in the bss section for a local SYMBOL,
     aligned to the power of two specified by ALIGN.  LENGTH and ALIGN
     must be positive absolute expressions.  This directive differs
     from `.lcomm' only in that it permits you to specify an alignment.
     *Note `.lcomm': Lcomm.

`.extended FLONUMS'
     `.extended' expects zero or more flonums, separated by commas; for
     each flonum, `.extended' emits an IEEE extended-format (80-bit)
     floating-point number.

`.leafproc CALL-LAB, BAL-LAB'
     You can use the `.leafproc' directive in conjunction with the
     optimized `callj' instruction to enable faster calls of leaf
     procedures.  If a procedure is known to call no other procedures,
     you may define an entry point that skips procedure prolog code
     (and that does not depend on system-supplied saved context), and
     declare it as the BAL-LAB using `.leafproc'.  If the procedure
     also has an entry point that goes through the normal prolog, you
     can specify that entry point as CALL-LAB.

     A `.leafproc' declaration is meant for use in conjunction with the
     optimized call instruction `callj'; the directive records the data
     needed later to choose between converting the `callj' into a `bal'
     or a `call'.

     CALL-LAB is optional; if only one argument is present, or if the
     two arguments are identical, the single argument is assumed to be
     the `bal' entry point.

`.sysproc NAME, INDEX'
     The `.sysproc' directive defines a name for a system procedure.
     After you define it using `.sysproc', you can use NAME to refer to
     the system procedure identified by INDEX when calling procedures
     with the optimized call instruction `callj'.

     Both arguments are required; INDEX must be between 0 and 31
     (inclusive).


File: as,  Node: Opcodes for i960,  Prev: Directives-i960,  Up: i960-Dependent

i960 Opcodes
------------

   All Intel 960 machine instructions are supported; *note i960
Command-line Options: Options-i960. for a discussion of selecting the
instruction subset for a particular 960 architecture.

   Some opcodes are processed beyond simply emitting a single
corresponding instruction: `callj', and Compare-and-Branch or
Compare-and-Jump instructions with target displacements larger than 13
bits.

* Menu:

* callj-i960::                  `callj'
* Compare-and-branch-i960::     Compare-and-Branch


File: as,  Node: callj-i960,  Next: Compare-and-branch-i960,  Up: Opcodes for i960

`callj'
.......

   You can write `callj' to have the assembler or the linker determine
the most appropriate form of subroutine call: `call', `bal', or
`calls'.  If the assembly source contains enough information--a
`.leafproc' or `.sysproc' directive defining the operand--then `as'
will translate the `callj'; if not, it will simply emit the `callj',
leaving it for the linker to resolve.


File: as,  Node: Compare-and-branch-i960,  Prev: callj-i960,  Up: Opcodes for i960

Compare-and-Branch
..................

   The 960 architectures provide combined Compare-and-Branch
instructions that permit you to store the branch target in the lower 13
bits of the instruction word itself.  However, if you specify a branch
target far enough away that its address won't fit in 13 bits, the
assembler can either issue an error, or convert your Compare-and-Branch
instruction into separate instructions to do the compare and the branch.

   Whether `as' gives an error or expands the instruction depends on
two choices you can make: whether you use the `-norelax' option, and
whether you use a "Compare and Branch" instruction or a "Compare and
Jump" instruction.  The "Jump" instructions are *always* expanded if
necessary; the "Branch" instructions are expanded when necessary
*unless* you specify `-norelax'--in which case `as' gives an error
instead.

   These are the Compare-and-Branch instructions, their "Jump" variants,
and the instruction pairs they may expand into:

             Compare and
          Branch      Jump       Expanded to
          ------    ------       ------------
             bbc                 chkbit; bno
             bbs                 chkbit; bo
          cmpibe    cmpije       cmpi; be
          cmpibg    cmpijg       cmpi; bg
         cmpibge   cmpijge       cmpi; bge
          cmpibl    cmpijl       cmpi; bl
         cmpible   cmpijle       cmpi; ble
         cmpibno   cmpijno       cmpi; bno
         cmpibne   cmpijne       cmpi; bne
          cmpibo    cmpijo       cmpi; bo
          cmpobe    cmpoje       cmpo; be
          cmpobg    cmpojg       cmpo; bg
         cmpobge   cmpojge       cmpo; bge
          cmpobl    cmpojl       cmpo; bl
         cmpoble   cmpojle       cmpo; ble
         cmpobne   cmpojne       cmpo; bne


File: as,  Node: M68K-Dependent,  Next: Sparc-Dependent,  Prev: i960-Dependent,  Up: Machine Dependencies

M680x0 Dependent Features
=========================

* Menu:

* M68K-Opts::                   M680x0 Options
* M68K-Syntax::                 Syntax
* M68K-Moto-Syntax::            Motorola Syntax
* M68K-Float::                  Floating Point
* M68K-Directives::             680x0 Machine Directives
* M68K-opcodes::                Opcodes


File: as,  Node: M68K-Opts,  Next: M68K-Syntax,  Up: M68K-Dependent

M680x0 Options
--------------

   The Motorola 680x0 version of `as' has two machine dependent options.
One shortens undefined references from 32 to 16 bits, while the other
is used to tell `as' what kind of machine it is assembling for.

   You can use the `-l' option to shorten the size of references to
undefined symbols.  If the `-l' option is not given, references to
undefined symbols will be a full long (32 bits) wide.  (Since `as'
cannot know where these symbols will end up, `as' can only allocate
space for the linker to fill in later.  Since `as' doesn't know how far
away these symbols will be, it allocates as much space as it can.) If
this option is given, the references will only be one word wide (16
bits).  This may be useful if you want the object file to be as small as
possible, and you know that the relevant symbols will be less than 17
bits away.

   The 680x0 version of `as' is most frequently used to assemble
programs for the Motorola MC68020 microprocessor.  Occasionally it is
used to assemble programs for the mostly similar, but slightly different
MC68000 or MC68010 microprocessors.  You can give `as' the options
`-m68000', `-mc68000', `-m68010', `-mc68010', `-m68020', and `-mc68020'
to tell it what processor is the target.


File: as,  Node: M68K-Syntax,  Next: M68K-Moto-Syntax,  Prev: M68K-Opts,  Up: M68K-Dependent

Syntax
------

   This syntax for the Motorola 680x0 was developed at MIT.

   The 680x0 version of `as' uses syntax similar to the Sun assembler.
Intervening periods are now ignored; for example, `movl' is equivalent
to `move.l'.

   In the following table "apc" stands for any of the address registers
(`a0' through `a7'), nothing, (`'), the Program Counter (`pc'), or the
zero-address relative to the program counter (`zpc').

   The following addressing modes are understood:
"Immediate"
     `#DIGITS'

"Data Register"
     `d0' through `d7'

"Address Register"
     `a0' through `a7'

"Address Register Indirect"
     `a0@' through `a7@'
     `a7' is also known as `sp', i.e. the Stack Pointer.  `a6' is also
     known as `fp', the Frame Pointer.

"Address Register Postincrement"
     `a0@+' through `a7@+'

"Address Register Predecrement"
     `a0@-' through `a7@-'

"Indirect Plus Offset"
     `APC@(DIGITS)'

"Index"
     `APC@(DIGITS,REGISTER:SIZE:SCALE)'

     or `APC@(REGISTER:SIZE:SCALE)'

"Postindex"
     `APC@(DIGITS)@(DIGITS,REGISTER:SIZE:SCALE)'

     or `APC@(DIGITS)@(REGISTER:SIZE:SCALE)'

"Preindex"
     `APC@(DIGITS,REGISTER:SIZE:SCALE)@(DIGITS)'

     or `APC@(REGISTER:SIZE:SCALE)@(DIGITS)'

"Memory Indirect"
     `APC@(DIGITS)@(DIGITS)'

"Absolute"
     `SYMBOL', or `DIGITS'

   For some configurations, especially those where the compiler normally
does not prepend an underscore to the names of user variables, the
assembler requires a `%' before any use of a register name.  This is
intended to let the assembler distinguish between user variables and
registers named `a0' through `a7', et cetera.  The `%' is always
accepted, but is only required for some configurations, notably
`m68k-coff'.


File: as,  Node: M68K-Moto-Syntax,  Next: M68K-Float,  Prev: M68K-Syntax,  Up: M68K-Dependent

Motorola Syntax
---------------

   The standard Motorola syntax for this chip differs from the syntax
already discussed (*note Syntax: M68K-Syntax.).  `as' can accept both
kinds of syntax, even within a single instruction.  The syntaxes are
fully compatible, because the Motorola syntax never uses the `@'
character and the MIT syntax always does, except in cases where the
syntaxes are identical.

   In particular, you may write or generate M68K assembler with the
following conventions:

   (In the following table "apc" stands for any of the address
registers (`a0' through `a7'), nothing, (`'), the Program Counter
(`pc'), or the zero-address relative to the program counter (`zpc').)

   The following additional addressing modes are understood:
"Address Register Indirect"
     `a0' through `a7'
     `a7' is also known as `sp', i.e. the Stack Pointer.  `a6' is also
     known as `fp', the Frame Pointer.

"Address Register Postincrement"
     `(a0)+' through `(a7)+'

"Address Register Predecrement"
     `-(a0)' through `-(a7)'

"Indirect Plus Offset"
     `DIGITS(APC)'

"Index"
     `DIGITS(APC,(REGISTER.SIZE*SCALE)'
     or `(APC,REGISTER.SIZE*SCALE)'
     In either case, SIZE and SCALE are optional (SCALE defaults to
     `1', SIZE defaults to `l').   SCALE can be `1', `2', `4', or `8'.
     SIZE can be `w' or `l'.  SCALE is only supported on the 68020 and
     greater.


File: as,  Node: M68K-Float,  Next: M68K-Directives,  Prev: M68K-Moto-Syntax,  Up: M68K-Dependent

Floating Point
--------------

   The floating point code is not too well tested, and may have subtle
bugs in it.

   Packed decimal (P) format floating literals are not supported.  Feel
free to add the code!

   The floating point formats generated by directives are these.

`.float'
     `Single' precision floating point constants.

`.double'
     `Double' precision floating point constants.

   There is no directive to produce regions of memory holding extended
precision numbers, however they can be used as immediate operands to
floating-point instructions.  Adding a directive to create extended
precision numbers would not be hard, but it has not yet seemed
necessary.


File: as,  Node: M68K-Directives,  Next: M68K-opcodes,  Prev: M68K-Float,  Up: M68K-Dependent

680x0 Machine Directives
------------------------

   In order to be compatible with the Sun assembler the 680x0 assembler
understands the following directives.

`.data1'
     This directive is identical to a `.data 1' directive.

`.data2'
     This directive is identical to a `.data 2' directive.

`.even'
     This directive is identical to a `.align 1' directive.

`.skip'
     This directive is identical to a `.space' directive.


File: as,  Node: M68K-opcodes,  Prev: M68K-Directives,  Up: M68K-Dependent

Opcodes
-------

* Menu:

* M68K-Branch::                 Branch Improvement
* M68K-Chars::                  Special Characters


File: as,  Node: M68K-Branch,  Next: M68K-Chars,  Up: M68K-opcodes

Branch Improvement
..................

   Certain pseudo opcodes are permitted for branch instructions.  They
expand to the shortest branch instruction that will reach the target.
Generally these mnemonics are made by substituting `j' for `b' at the
start of a Motorola mnemonic.

   The following table summarizes the pseudo-operations.  A `*' flags
cases that are more fully described after the table:

               Displacement
               +-------------------------------------------------
               |                68020   68000/10
     Pseudo-Op |BYTE    WORD    LONG    LONG      non-PC relative
               +-------------------------------------------------
          jbsr |bsrs    bsr     bsrl    jsr       jsr
           jra |bras    bra     bral    jmp       jmp
     *     jXX |bXXs    bXX     bXXl    bNXs;jmpl bNXs;jmp
     *    dbXX |dbXX    dbXX        dbXX; bra; jmpl
     *    fjXX |fbXXw   fbXXw   fbXXl             fbNXw;jmp

     XX: condition
     NX: negative of condition XX

                    `*'--see full description below

`jbsr'
`jra'
     These are the simplest jump pseudo-operations; they always map to
     one particular machine instruction, depending on the displacement
     to the branch target.

`jXX'
     Here, `jXX' stands for an entire family of pseudo-operations,
     where XX is a conditional branch or condition-code test.  The full
     list of pseudo-ops in this family is:
           jhi   jls   jcc   jcs   jne   jeq   jvc
           jvs   jpl   jmi   jge   jlt   jgt   jle

     For the cases of non-PC relative displacements and long
     displacements on the 68000 or 68010, `as' will issue a longer code
     fragment in terms of NX, the opposite condition to XX.  For
     example, for the non-PC relative case:
              jXX foo
     gives
               bNXs oof
               jmp foo
           oof:

`dbXX'
     The full family of pseudo-operations covered here is
           dbhi   dbls   dbcc   dbcs   dbne   dbeq   dbvc
           dbvs   dbpl   dbmi   dbge   dblt   dbgt   dble
           dbf    dbra   dbt

     Other than for word and byte displacements, when the source reads
     `dbXX foo', `as' will emit
               dbXX oo1
               bra oo2
           oo1:jmpl foo
           oo2:

`fjXX'
     This family includes
           fjne   fjeq   fjge   fjlt   fjgt   fjle   fjf
           fjt    fjgl   fjgle  fjnge  fjngl  fjngle fjngt
           fjnle  fjnlt  fjoge  fjogl  fjogt  fjole  fjolt
           fjor   fjseq  fjsf   fjsne  fjst   fjueq  fjuge
           fjugt  fjule  fjult  fjun

     For branch targets that are not PC relative, `as' emits
               fbNX oof
               jmp foo
           oof:
     when it encounters `fjXX foo'.


File: as,  Node: M68K-Chars,  Prev: M68K-Branch,  Up: M68K-opcodes

Special Characters
..................

   The immediate character is `#' for Sun compatibility.  The
line-comment character is `|'.  If a `#' appears at the beginning of a
line, it is treated as a comment unless it looks like `# line file', in
which case it is treated normally.


File: as,  Node: Sparc-Dependent,  Next: Z8000-Dependent,  Prev: M68K-Dependent,  Up: Machine Dependencies

SPARC Dependent Features
========================

* Menu:

* Sparc-Opts::                  Options
* Sparc-Float::                 Floating Point
* Sparc-Directives::            Sparc Machine Directives


File: as,  Node: Sparc-Opts,  Next: Sparc-Float,  Up: Sparc-Dependent

Options
-------

   The SPARC chip family includes several successive levels (or other
variants) of chip, using the same core instruction set, but including a
few additional instructions at each level.

   By default, `as' assumes the core instruction set (SPARC v6), but
"bumps" the architecture level as needed: it switches to successively
higher architectures as it encounters instructions that only exist in
the higher levels.

`-Av6 | -Av7 | -Av8 | -Asparclite'
     Use one of the `-A' options to select one of the SPARC
     architectures explicitly.  If you select an architecture
     explicitly, `as' reports a fatal error if it encounters an
     instruction or feature requiring a higher level.

`-bump'
     Permit the assembler to "bump" the architecture level as required,
     but warn whenever it is necessary to switch to another level.


File: as,  Node: Sparc-Float,  Next: Sparc-Directives,  Prev: Sparc-Opts,  Up: Sparc-Dependent

Floating Point
--------------

   The Sparc uses IEEE floating-point numbers.


File: as,  Node: Sparc-Directives,  Prev: Sparc-Float,  Up: Sparc-Dependent

Sparc Machine Directives
------------------------

   The Sparc version of `as' supports the following additional machine
directives:

`.common'
     This must be followed by a symbol name, a positive number, and
     `"bss"'.  This behaves somewhat like `.comm', but the syntax is
     different.

`.half'
     This is functionally identical to `.short'.

`.proc'
     This directive is ignored.  Any text following it on the same line
     is also ignored.

`.reserve'
     This must be followed by a symbol name, a positive number, and
     `"bss"'.  This behaves somewhat like `.lcomm', but the syntax is
     different.

`.seg'
     This must be followed by `"text"', `"data"', or `"data1"'.  It
     behaves like `.text', `.data', or `.data 1'.

`.skip'
     This is functionally identical to the `.space' directive.

`.word'
     On the Sparc, the .word directive produces 32 bit values, instead
     of the 16 bit values it produces on many other machines.


File: as,  Node: i386-Dependent,  Prev: Z8000-Dependent,  Up: Machine Dependencies

80386 Dependent Features
========================

* Menu:

* i386-Options::                Options
* i386-Syntax::                 AT&T Syntax versus Intel Syntax
* i386-Opcodes::                Opcode Naming
* i386-Regs::                   Register Naming
* i386-prefixes::               Opcode Prefixes
* i386-Memory::                 Memory References
* i386-jumps::                  Handling of Jump Instructions
* i386-Float::                  Floating Point
* i386-Notes::                  Notes


File: as,  Node: i386-Options,  Next: i386-Syntax,  Up: i386-Dependent

Options
-------

   The 80386 has no machine dependent options.


File: as,  Node: i386-Syntax,  Next: i386-Opcodes,  Prev: i386-Options,  Up: i386-Dependent

AT&T Syntax versus Intel Syntax
-------------------------------

   In order to maintain compatibility with the output of `gcc', `as'
supports AT&T System V/386 assembler syntax.  This is quite different
from Intel syntax.  We mention these differences because almost all
80386 documents used only Intel syntax.  Notable differences between
the two syntaxes are:

   * AT&T immediate operands are preceded by `$'; Intel immediate
     operands are undelimited (Intel `push 4' is AT&T `pushl $4').
     AT&T register operands are preceded by `%'; Intel register operands
     are undelimited.  AT&T absolute (as opposed to PC relative)
     jump/call operands are prefixed by `*'; they are undelimited in
     Intel syntax.

   * AT&T and Intel syntax use the opposite order for source and
     destination operands.  Intel `add eax, 4' is `addl $4, %eax'.  The
     `source, dest' convention is maintained for compatibility with
     previous Unix assemblers.

   * In AT&T syntax the size of memory operands is determined from the
     last character of the opcode name.  Opcode suffixes of `b', `w',
     and `l' specify byte (8-bit), word (16-bit), and long (32-bit)
     memory references.  Intel syntax accomplishes this by prefixes
     memory operands (*not* the opcodes themselves) with `byte ptr',
     `word ptr', and `dword ptr'.  Thus, Intel `mov al, byte ptr FOO'
     is `movb FOO, %al' in AT&T syntax.

   * Immediate form long jumps and calls are `lcall/ljmp $SECTION,
     $OFFSET' in AT&T syntax; the Intel syntax is `call/jmp far
     SECTION:OFFSET'.  Also, the far return instruction is `lret
     $STACK-ADJUST' in AT&T syntax; Intel syntax is `ret far
     STACK-ADJUST'.

   * The AT&T assembler does not provide support for multiple section
     programs.  Unix style systems expect all programs to be single
     sections.


File: as,  Node: i386-Opcodes,  Next: i386-Regs,  Prev: i386-Syntax,  Up: i386-Dependent

Opcode Naming
-------------

   Opcode names are suffixed with one character modifiers which specify
the size of operands.  The letters `b', `w', and `l' specify byte,
word, and long operands.  If no suffix is specified by an instruction
and it contains no memory operands then `as' tries to fill in the
missing suffix based on the destination register operand (the last one
by convention).  Thus, `mov %ax, %bx' is equivalent to `movw %ax, %bx';
also, `mov $1, %bx' is equivalent to `movw $1, %bx'.  Note that this is
incompatible with the AT&T Unix assembler which assumes that a missing
opcode suffix implies long operand size.  (This incompatibility does
not affect compiler output since compilers always explicitly specify
the opcode suffix.)

   Almost all opcodes have the same names in AT&T and Intel format.
There are a few exceptions.  The sign extend and zero extend
instructions need two sizes to specify them.  They need a size to
sign/zero extend *from* and a size to zero extend *to*.  This is
accomplished by using two opcode suffixes in AT&T syntax.  Base names
for sign extend and zero extend are `movs...' and `movz...' in AT&T
syntax (`movsx' and `movzx' in Intel syntax).  The opcode suffixes are
tacked on to this base name, the *from* suffix before the *to* suffix.
Thus, `movsbl %al, %edx' is AT&T syntax for "move sign extend *from*
%al *to* %edx."  Possible suffixes, thus, are `bl' (from byte to long),
`bw' (from byte to word), and `wl' (from word to long).

   The Intel-syntax conversion instructions

   * `cbw' -- sign-extend byte in `%al' to word in `%ax',

   * `cwde' -- sign-extend word in `%ax' to long in `%eax',

   * `cwd' -- sign-extend word in `%ax' to long in `%dx:%ax',

   * `cdq' -- sign-extend dword in `%eax' to quad in `%edx:%eax',

are called `cbtw', `cwtl', `cwtd', and `cltd' in AT&T naming.  `as'
accepts either naming for these instructions.

   Far call/jump instructions are `lcall' and `ljmp' in AT&T syntax,
but are `call far' and `jump far' in Intel convention.


File: as,  Node: i386-Regs,  Next: i386-prefixes,  Prev: i386-Opcodes,  Up: i386-Dependent

Register Naming
---------------

   Register operands are always prefixes with `%'.  The 80386 registers
consist of

   * the 8 32-bit registers `%eax' (the accumulator), `%ebx', `%ecx',
     `%edx', `%edi', `%esi', `%ebp' (the frame pointer), and `%esp'
     (the stack pointer).

   * the 8 16-bit low-ends of these: `%ax', `%bx', `%cx', `%dx', `%di',
     `%si', `%bp', and `%sp'.

   * the 8 8-bit registers: `%ah', `%al', `%bh', `%bl', `%ch', `%cl',
     `%dh', and `%dl' (These are the high-bytes and low-bytes of `%ax',
     `%bx', `%cx', and `%dx')

   * the 6 section registers `%cs' (code section), `%ds' (data
     section), `%ss' (stack section), `%es', `%fs', and `%gs'.

   * the 3 processor control registers `%cr0', `%cr2', and `%cr3'.

   * the 6 debug registers `%db0', `%db1', `%db2', `%db3', `%db6', and
     `%db7'.

   * the 2 test registers `%tr6' and `%tr7'.

   * the 8 floating point register stack `%st' or equivalently
     `%st(0)', `%st(1)', `%st(2)', `%st(3)', `%st(4)', `%st(5)',
     `%st(6)', and `%st(7)'.


File: as,  Node: i386-prefixes,  Next: i386-Memory,  Prev: i386-Regs,  Up: i386-Dependent

Opcode Prefixes
---------------

   Opcode prefixes are used to modify the following opcode.  They are
used to repeat string instructions, to provide section overrides, to
perform bus lock operations, and to give operand and address size
(16-bit operands are specified in an instruction by prefixing what would
normally be 32-bit operands with a "operand size" opcode prefix).
Opcode prefixes are usually given as single-line instructions with no
operands, and must directly precede the instruction they act upon.  For
example, the `scas' (scan string) instruction is repeated with:
             repne
             scas

   Here is a list of opcode prefixes:

   * Section override prefixes `cs', `ds', `ss', `es', `fs', `gs'.
     These are automatically added by specifying using the
     SECTION:MEMORY-OPERAND form for memory references.

   * Operand/Address size prefixes `data16' and `addr16' change 32-bit
     operands/addresses into 16-bit operands/addresses.  Note that
     16-bit addressing modes (i.e. 8086 and 80286 addressing modes) are
     not supported (yet).

   * The bus lock prefix `lock' inhibits interrupts during execution of
     the instruction it precedes.  (This is only valid with certain
     instructions; see a 80386 manual for details).

   * The wait for coprocessor prefix `wait' waits for the coprocessor
     to complete the current instruction.  This should never be needed
     for the 80386/80387 combination.

   * The `rep', `repe', and `repne' prefixes are added to string
     instructions to make them repeat `%ecx' times.


File: as,  Node: i386-Memory,  Next: i386-jumps,  Prev: i386-prefixes,  Up: i386-Dependent

Memory References
-----------------

   An Intel syntax indirect memory reference of the form

     SECTION:[BASE + INDEX*SCALE + DISP]

is translated into the AT&T syntax

     SECTION:DISP(BASE, INDEX, SCALE)

where BASE and INDEX are the optional 32-bit base and index registers,
DISP is the optional displacement, and SCALE, taking the values 1, 2,
4, and 8, multiplies INDEX to calculate the address of the operand.  If
no SCALE is specified, SCALE is taken to be 1.  SECTION specifies the
optional section register for the memory operand, and may override the
default section register (see a 80386 manual for section register
defaults). Note that section overrides in AT&T syntax *must* have be
preceded by a `%'.  If you specify a section override which coincides
with the default section register, `as' will *not* output any section
register override prefixes to assemble the given instruction.  Thus,
section overrides can be specified to emphasize which section register
is used for a given memory operand.

   Here are some examples of Intel and AT&T style memory references:

AT&T: `-4(%ebp)', Intel:  `[ebp - 4]'
     BASE is `%ebp'; DISP is `-4'. SECTION is missing, and the default
     section is used (`%ss' for addressing with `%ebp' as the base
     register).  INDEX, SCALE are both missing.

AT&T: `foo(,%eax,4)', Intel: `[foo + eax*4]'
     INDEX is `%eax' (scaled by a SCALE 4); DISP is `foo'.  All other
     fields are missing.  The section register here defaults to `%ds'.

AT&T: `foo(,1)'; Intel `[foo]'
     This uses the value pointed to by `foo' as a memory operand.  Note
     that BASE and INDEX are both missing, but there is only *one* `,'.
     This is a syntactic exception.

AT&T: `%gs:foo'; Intel `gs:foo'
     This selects the contents of the variable `foo' with section
     register SECTION being `%gs'.

   Absolute (as opposed to PC relative) call and jump operands must be
prefixed with `*'.  If no `*' is specified, `as' will always choose PC
relative addressing for jump/call labels.

   Any instruction that has a memory operand *must* specify its size
(byte, word, or long) with an opcode suffix (`b', `w', or `l',
respectively).


File: as,  Node: i386-jumps,  Next: i386-Float,  Prev: i386-Memory,  Up: i386-Dependent

Handling of Jump Instructions
-----------------------------

   Jump instructions are always optimized to use the smallest possible
displacements.  This is accomplished by using byte (8-bit) displacement
jumps whenever the target is sufficiently close.  If a byte displacement
is insufficient a long (32-bit) displacement is used.  We do not support
word (16-bit) displacement jumps (i.e. prefixing the jump instruction
with the `addr16' opcode prefix), since the 80386 insists upon masking
`%eip' to 16 bits after the word displacement is added.

   Note that the `jcxz', `jecxz', `loop', `loopz', `loope', `loopnz'
and `loopne' instructions only come in byte displacements, so that it
is possible that use of these instructions (`gcc' does not use them)
will cause the assembler to print an error message (and generate
incorrect code).  The AT&T 80386 assembler tries to get around this
problem by expanding `jcxz foo' to
              jcxz cx_zero
              jmp cx_nonzero
     cx_zero: jmp foo
     cx_nonzero:


File: as,  Node: i386-Float,  Next: i386-Notes,  Prev: i386-jumps,  Up: i386-Dependent

Floating Point
--------------

   All 80387 floating point types except packed BCD are supported.
(BCD support may be added without much difficulty).  These data types
are 16-, 32-, and 64- bit integers, and single (32-bit), double
(64-bit), and extended (80-bit) precision floating point.  Each
supported type has an opcode suffix and a constructor associated with
it.  Opcode suffixes specify operand's data types.  Constructors build
these data types into memory.

   * Floating point constructors are `.float' or `.single', `.double',
     and `.tfloat' for 32-, 64-, and 80-bit formats.  These correspond
     to opcode suffixes `s', `l', and `t'.  `t' stands for temporary
     real, and that the 80387 only supports this format via the `fldt'
     (load temporary real to stack top) and `fstpt' (store temporary
     real and pop stack) instructions.

   * Integer constructors are `.word', `.long' or `.int', and `.quad'
     for the 16-, 32-, and 64-bit integer formats.  The corresponding
     opcode suffixes are `s' (single), `l' (long), and `q' (quad).  As
     with the temporary real format the 64-bit `q' format is only
     present in the `fildq' (load quad integer to stack top) and
     `fistpq' (store quad integer and pop stack) instructions.

   Register to register operations do not require opcode suffixes, so
that `fst %st, %st(1)' is equivalent to `fstl %st, %st(1)'.

   Since the 80387 automatically synchronizes with the 80386 `fwait'
instructions are almost never needed (this is not the case for the
80286/80287 and 8086/8087 combinations).  Therefore, `as' suppresses
the `fwait' instruction whenever it is implicitly selected by one of
the `fn...' instructions.  For example, `fsave' and `fnsave' are
treated identically.  In general, all the `fn...' instructions are made
equivalent to `f...' instructions.  If `fwait' is desired it must be
explicitly coded.


File: as,  Node: i386-Notes,  Prev: i386-Float,  Up: i386-Dependent

Notes
-----

   There is some trickery concerning the `mul' and `imul' instructions
that deserves mention.  The 16-, 32-, and 64-bit expanding multiplies
(base opcode `0xf6'; extension 4 for `mul' and 5 for `imul') can be
output only in the one operand form.  Thus, `imul %ebx, %eax' does
*not* select the expanding multiply; the expanding multiply would
clobber the `%edx' register, and this would confuse `gcc' output.  Use
`imul %ebx' to get the 64-bit product in `%edx:%eax'.

   We have added a two operand form of `imul' when the first operand is
an immediate mode expression and the second operand is a register.
This is just a shorthand, so that, multiplying `%eax' by 69, for
example, can be done with `imul $69, %eax' rather than `imul $69, %eax,
%eax'.


File: as,  Node: Z8000-Dependent,  Next: i386-Dependent,  Prev: Sparc-Dependent,  Up: Machine Dependencies

Z8000 Dependent Features
========================

   The Z8000 as supports both members of the Z8000 family: the
unsegmented Z8002, with 16 bit addresses, and the segmented Z8001 with
24 bit addresses.

   When the assembler is in unsegmented mode (specified with the
`unsegm' directive), an address will take up one word (16 bit) sized
register.  When the assembler is in segmented mode (specified with the
`segm' directive), a 24-bit address takes up a long (32 bit) register.
*Note Assembler Directives for the Z8000: Z8000 Directives, for a list
of other Z8000 specific assembler directives.

* Menu:

* Z8000 Options::               No special command-line options for Z8000
* Z8000 Syntax::                Assembler syntax for the Z8000
* Z8000 Directives::            Special directives for the Z8000
* Z8000 Opcodes::               Opcodes


File: as,  Node: Z8000 Options,  Next: Z8000 Syntax,  Up: Z8000-Dependent

Options
-------

   `as' has no additional command-line options for the Zilog Z8000
family.


File: as,  Node: Z8000 Syntax,  Next: Z8000 Directives,  Prev: Z8000 Options,  Up: Z8000-Dependent

Syntax
------

* Menu:

* Z8000-Chars::                Special Characters
* Z8000-Regs::                 Register Names
* Z8000-Addressing::           Addressing Modes


File: as,  Node: Z8000-Chars,  Next: Z8000-Regs,  Up: Z8000 Syntax

Special Characters
..................

   `!' is the line comment character.

   You can use `;' instead of a newline to separate statements.


File: as,  Node: Z8000-Regs,  Next: Z8000-Addressing,  Prev: Z8000-Chars,  Up: Z8000 Syntax

Register Names
..............

   The Z8000 has sixteen 16 bit registers, numbered 0 to 15.  You can
refer to different sized groups of registers by register number, with
the prefix `r' for 16 bit registers, `rr' for 32 bit registers and `rq'
for 64 bit registers.  You can also refer to the contents of the first
eight (of the sixteen 16 bit registers) by bytes.  They are named `rNh'
and `rNl'.

*byte registers*
     r0l r0h r1h r1l r2h r2l r3h r3l
     r4h r4l r5h r5l r6h r6l r7h r7l
*word registers*
     r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12 r13 r14 r15
*long word registers*
     rr0 rr2 rr4 rr6 rr8 rr10 rr12 rr14
*quad word registers*
     rq0 rq4 rq8 rq12


File: as,  Node: Z8000-Addressing,  Prev: Z8000-Regs,  Up: Z8000 Syntax

Addressing Modes
................

   as understands the following addressing modes for the Z8000:

`rN'
     Register direct

`@rN'
     Indirect register

`ADDR'
     Direct: the 16 bit or 24 bit address (depending on whether the
     assembler is in segmented or unsegmented mode) of the operand is
     in the instruction.

`address(rN)'
     Indexed: the 16 or 24 bit address is added to the 16 bit register
     to produce the final address in memory of the operand.

`rN(#IMM)'
     Base Address: the 16 or 24 bit register is added to the 16 bit sign
     extended immediate displacement to produce the final address in
     memory of the operand.

`rN(rM)'
     Base Index: the 16 or 24 bit register rN is added to the sign
     extended 16 bit index register rM to produce the final address in
     memory of the operand.

`#XX'
     Immediate data XX.


File: as,  Node: Z8000 Directives,  Next: Z8000 Opcodes,  Prev: Z8000 Syntax,  Up: Z8000-Dependent

Assembler Directives for the Z8000
----------------------------------

   The Z8000 port of as includes these additional assembler directives,
for compatibility with other Z8000 assemblers.  As shown, these do not
begin with `.' (unlike the ordinary as directives).

`segm'
     Generates code for the segmented Z8001.

`unsegm'
     Generates code for the unsegmented Z8002.

`name'
     Synonym for `.file'

`global'
     Synonum for `.global'

`wval'
     Synonym for `.word'

`lval'
     Synonym for `.long'

`bval'
     Synonym for `.byte'

`sval'
     Assemble a string.  `sval' expects one string literal, delimited by
     single quotes.  It assembles each byte of the string into
     consecutive addresses.  You can use the escape sequence `%XX'
     (where XX represents a two-digit hexadecimal number) to represent
     the character whose ASCII value is XX.  Use this feature to
     describe single quote and other characters that may not appear in
     string literals as themselves.  For example, the C statement
     `char *a = "he said \"it's 50% off\"";' is represented in Z8000
     assembly language (shown with the assembler output in hex at the
     left) as

          68652073    sval    'he said %22it%27s 50%25 off%22%00'
          61696420
          22697427
          73203530
          25206F66
          662200

`rsect'
     synonym for `.section'

`block'
     synonym for `.space'

`even'
     synonym for `.align 1'


File: as,  Node: Z8000 Opcodes,  Prev: Z8000 Directives,  Up: Z8000-Dependent

Opcodes
-------

   For detailed information on the Z8000 machine instruction set, see
`Z8000 Technical Manual'.

   The following table summarizes the opcodes and their arguments:

                 rs   16 bit source register
                 rd   16 bit destination register
                 rbs   8 bit source register
                 rbd   8 bit destination register
                 rrs   32 bit source register
                 rrd   32 bit destination register
                 rqs   64 bit source register
                 rqd   64 bit destination register
                 addr 16/24 bit address
                 imm  immediate data

     adc rd,rs               clrb addr               cpsir @rd,@rs,rr,cc
     adcb rbd,rbs            clrb addr(rd)           cpsirb @rd,@rs,rr,cc
     add rd,@rs              clrb rbd                dab rbd
     add rd,addr             com @rd                 dbjnz rbd,disp7
     add rd,addr(rs)         com addr                dec @rd,imm4m1
     add rd,imm16            com addr(rd)            dec addr(rd),imm4m1
     add rd,rs               com rd                  dec addr,imm4m1
     addb rbd,@rs            comb @rd                dec rd,imm4m1
     addb rbd,addr           comb addr               decb @rd,imm4m1
     addb rbd,addr(rs)       comb addr(rd)           decb addr(rd),imm4m1
     addb rbd,imm8           comb rbd                decb addr,imm4m1
     addb rbd,rbs            comflg flags            decb rbd,imm4m1
     addl rrd,@rs            cp @rd,imm16            di i2
     addl rrd,addr           cp addr(rd),imm16       div rrd,@rs
     addl rrd,addr(rs)       cp addr,imm16           div rrd,addr
     addl rrd,imm32          cp rd,@rs               div rrd,addr(rs)
     addl rrd,rrs            cp rd,addr              div rrd,imm16
     and rd,@rs              cp rd,addr(rs)          div rrd,rs
     and rd,addr             cp rd,imm16             divl rqd,@rs
     and rd,addr(rs)         cp rd,rs                divl rqd,addr
     and rd,imm16            cpb @rd,imm8            divl rqd,addr(rs)
     and rd,rs               cpb addr(rd),imm8       divl rqd,imm32
     andb rbd,@rs            cpb addr,imm8           divl rqd,rrs
     andb rbd,addr           cpb rbd,@rs             djnz rd,disp7
     andb rbd,addr(rs)       cpb rbd,addr            ei i2
     andb rbd,imm8           cpb rbd,addr(rs)        ex rd,@rs
     andb rbd,rbs            cpb rbd,imm8            ex rd,addr
     bit @rd,imm4            cpb rbd,rbs             ex rd,addr(rs)
     bit addr(rd),imm4       cpd rd,@rs,rr,cc        ex rd,rs
     bit addr,imm4           cpdb rbd,@rs,rr,cc      exb rbd,@rs
     bit rd,imm4             cpdr rd,@rs,rr,cc       exb rbd,addr
     bit rd,rs               cpdrb rbd,@rs,rr,cc     exb rbd,addr(rs)
     bitb @rd,imm4           cpi rd,@rs,rr,cc        exb rbd,rbs
     bitb addr(rd),imm4      cpib rbd,@rs,rr,cc      ext0e imm8
     bitb addr,imm4          cpir rd,@rs,rr,cc       ext0f imm8
     bitb rbd,imm4           cpirb rbd,@rs,rr,cc     ext8e imm8
     bitb rbd,rs             cpl rrd,@rs             ext8f imm8
     bpt                     cpl rrd,addr            exts rrd
     call @rd                cpl rrd,addr(rs)        extsb rd
     call addr               cpl rrd,imm32           extsl rqd
     call addr(rd)           cpl rrd,rrs             halt
     calr disp12             cpsd @rd,@rs,rr,cc      in rd,@rs
     clr @rd                 cpsdb @rd,@rs,rr,cc     in rd,imm16
     clr addr                cpsdr @rd,@rs,rr,cc     inb rbd,@rs
     clr addr(rd)            cpsdrb @rd,@rs,rr,cc    inb rbd,imm16
     clr rd                  cpsi @rd,@rs,rr,cc      inc @rd,imm4m1
     clrb @rd                cpsib @rd,@rs,rr,cc     inc addr(rd),imm4m1
     inc addr,imm4m1         ldb rbd,rs(rx)          mult rrd,addr(rs)
     inc rd,imm4m1           ldb rd(imm16),rbs       mult rrd,imm16
     incb @rd,imm4m1         ldb rd(rx),rbs          mult rrd,rs
     incb addr(rd),imm4m1    ldctl ctrl,rs           multl rqd,@rs
     incb addr,imm4m1        ldctl rd,ctrl           multl rqd,addr
     incb rbd,imm4m1         ldd @rs,@rd,rr          multl rqd,addr(rs)
     ind @rd,@rs,ra          lddb @rs,@rd,rr         multl rqd,imm32
     indb @rd,@rs,rba        lddr @rs,@rd,rr         multl rqd,rrs
     inib @rd,@rs,ra         lddrb @rs,@rd,rr        neg @rd
     inibr @rd,@rs,ra        ldi @rd,@rs,rr          neg addr
     iret                    ldib @rd,@rs,rr         neg addr(rd)
     jp cc,@rd               ldir @rd,@rs,rr         neg rd
     jp cc,addr              ldirb @rd,@rs,rr        negb @rd
     jp cc,addr(rd)          ldk rd,imm4             negb addr
     jr cc,disp8             ldl @rd,rrs             negb addr(rd)
     ld @rd,imm16            ldl addr(rd),rrs        negb rbd
     ld @rd,rs               ldl addr,rrs            nop
     ld addr(rd),imm16       ldl rd(imm16),rrs       or rd,@rs
     ld addr(rd),rs          ldl rd(rx),rrs          or rd,addr
     ld addr,imm16           ldl rrd,@rs             or rd,addr(rs)
     ld addr,rs              ldl rrd,addr            or rd,imm16
     ld rd(imm16),rs         ldl rrd,addr(rs)        or rd,rs
     ld rd(rx),rs            ldl rrd,imm32           orb rbd,@rs
     ld rd,@rs               ldl rrd,rrs             orb rbd,addr
     ld rd,addr              ldl rrd,rs(imm16)       orb rbd,addr(rs)
     ld rd,addr(rs)          ldl rrd,rs(rx)          orb rbd,imm8
     ld rd,imm16             ldm @rd,rs,n            orb rbd,rbs
     ld rd,rs                ldm addr(rd),rs,n       out @rd,rs
     ld rd,rs(imm16)         ldm addr,rs,n           out imm16,rs
     ld rd,rs(rx)            ldm rd,@rs,n            outb @rd,rbs
     lda rd,addr             ldm rd,addr(rs),n       outb imm16,rbs
     lda rd,addr(rs)         ldm rd,addr,n           outd @rd,@rs,ra
     lda rd,rs(imm16)        ldps @rs                outdb @rd,@rs,rba
     lda rd,rs(rx)           ldps addr               outib @rd,@rs,ra
     ldar rd,disp16          ldps addr(rs)           outibr @rd,@rs,ra
     ldb @rd,imm8            ldr disp16,rs           pop @rd,@rs
     ldb @rd,rbs             ldr rd,disp16           pop addr(rd),@rs
     ldb addr(rd),imm8       ldrb disp16,rbs         pop addr,@rs
     ldb addr(rd),rbs        ldrb rbd,disp16         pop rd,@rs
     ldb addr,imm8           ldrl disp16,rrs         popl @rd,@rs
     ldb addr,rbs            ldrl rrd,disp16         popl addr(rd),@rs
     ldb rbd,@rs             mbit                    popl addr,@rs
     ldb rbd,addr            mreq rd                 popl rrd,@rs
     ldb rbd,addr(rs)        mres                    push @rd,@rs
     ldb rbd,imm8            mset                    push @rd,addr
     ldb rbd,rbs             mult rrd,@rs            push @rd,addr(rs)
     ldb rbd,rs(imm16)       mult rrd,addr           push @rd,imm16
     push @rd,rs             set addr,imm4           subl rrd,imm32
     pushl @rd,@rs           set rd,imm4             subl rrd,rrs
     pushl @rd,addr          set rd,rs               tcc cc,rd
     pushl @rd,addr(rs)      setb @rd,imm4           tccb cc,rbd
     pushl @rd,rrs           setb addr(rd),imm4      test @rd
     res @rd,imm4            setb addr,imm4          test addr
     res addr(rd),imm4       setb rbd,imm4           test addr(rd)
     res addr,imm4           setb rbd,rs             test rd
     res rd,imm4             setflg imm4             testb @rd
     res rd,rs               sinb rbd,imm16          testb addr
     resb @rd,imm4           sinb rd,imm16           testb addr(rd)
     resb addr(rd),imm4      sind @rd,@rs,ra         testb rbd
     resb addr,imm4          sindb @rd,@rs,rba       testl @rd
     resb rbd,imm4           sinib @rd,@rs,ra        testl addr
     resb rbd,rs             sinibr @rd,@rs,ra       testl addr(rd)
     resflg imm4             sla rd,imm8             testl rrd
     ret cc                  slab rbd,imm8           trdb @rd,@rs,rba
     rl rd,imm1or2           slal rrd,imm8           trdrb @rd,@rs,rba
     rlb rbd,imm1or2         sll rd,imm8             trib @rd,@rs,rbr
     rlc rd,imm1or2          sllb rbd,imm8           trirb @rd,@rs,rbr
     rlcb rbd,imm1or2        slll rrd,imm8           trtdrb @ra,@rb,rbr
     rldb rbb,rba            sout imm16,rs           trtib @ra,@rb,rr
     rr rd,imm1or2           soutb imm16,rbs         trtirb @ra,@rb,rbr
     rrb rbd,imm1or2         soutd @rd,@rs,ra        trtrb @ra,@rb,rbr
     rrc rd,imm1or2          soutdb @rd,@rs,rba      tset @rd
     rrcb rbd,imm1or2        soutib @rd,@rs,ra       tset addr
     rrdb rbb,rba            soutibr @rd,@rs,ra      tset addr(rd)
     rsvd36                  sra rd,imm8             tset rd
     rsvd38                  srab rbd,imm8           tsetb @rd
     rsvd78                  sral rrd,imm8           tsetb addr
     rsvd7e                  srl rd,imm8             tsetb addr(rd)
     rsvd9d                  srlb rbd,imm8           tsetb rbd
     rsvd9f                  srll rrd,imm8           xor rd,@rs
     rsvdb9                  sub rd,@rs              xor rd,addr
     rsvdbf                  sub rd,addr             xor rd,addr(rs)
     sbc rd,rs               sub rd,addr(rs)         xor rd,imm16
     sbcb rbd,rbs            sub rd,imm16            xor rd,rs
     sc imm8                 sub rd,rs               xorb rbd,@rs
     sda rd,rs               subb rbd,@rs            xorb rbd,addr
     sdab rbd,rs             subb rbd,addr           xorb rbd,addr(rs)
     sdal rrd,rs             subb rbd,addr(rs)       xorb rbd,imm8
     sdl rd,rs               subb rbd,imm8           xorb rbd,rbs
     sdlb rbd,rs             subb rbd,rbs            xorb rbd,rbs
     sdll rrd,rs             subl rrd,@rs
     set @rd,imm4            subl rrd,addr
     set addr(rd),imm4       subl rrd,addr(rs)


File: as,  Node: Acknowledgements,  Next: Index,  Prev: Copying,  Up: Top

Acknowledgements
****************

   If you've contributed to `as' and your name isn't listed here, it is
not meant as a slight.  We just don't know about it.  Send mail to the
maintainer, and we'll correct the situation.  Currently (June 1993), the
maintainer is Ken Raeburn (email address `[e-mail]').

   Dean Elsner wrote the original GNU assembler for the VAX.(1)

   Jay Fenlason maintained GAS for a while, adding support for
gdb-specific debug information and the 68k series machines, most of the
preprocessing pass, and extensive changes in messages.c, input-file.c,
write.c.

   K. Richard Pixley maintained GAS for a while, adding various
enhancements and many bug fixes, including merging support for several
processors, breaking GAS up to handle multiple object file format
backends (including heavy rewrite, testing, an integration of the coff
and b.out backends), adding configuration including heavy testing and
verification of cross assemblers and file splits and renaming,
converted GAS to strictly ansi C including full prototypes, added
support for m680[34]0 & cpu32, considerable work on i960 including a
COFF port (including considerable amounts of reverse engineering), a
SPARC opcode file rewrite, DECstation, rs6000, and hp300hpux host
ports, updated "know" assertions and made them work, much other
reorganization, cleanup, and lint.

   Ken Raeburn wrote the high-level BFD interface code to replace most
of the code in format-specific I/O modules.

   The original VMS support was contributed by David L. Kashtan.  Eric
Youngdale has done much work with it since.

   The Intel 80386 machine description was written by Eliot Dresselhaus.

   Minh Tran-Le at IntelliCorp contributed some AIX 386 support.

   The Motorola 88k machine description was contributed by Devon Bowen
of Buffalo University and Torbjorn Granlund of the Swedish Institute of
Computer Science.

   Keith Knowles at the Open Software Foundation wrote the original
MIPS back end (tc-mips.c, tc-mips.h), and contributed Rose format
support (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 Hitachi H8/300 and H8/500 processors
(tc-z8k, tc-h8300, tc-h8500), 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.

   John Gilmore built the AMD 29000 support, added .include support, and
simplified the configuration of which versions accept which pseudo-ops.
He updated the 68k machine description so that Motorola's opcodes
always produced fixed-size instructions (e.g. jsr), while synthetic
instructions remained shrinkable (jbsr).  John fixed many bugs,
including true tested cross-compilation support, and one bug in
relaxation that took a week and required the apocryphal one-bit fix.

   Ian Lance Taylor of Cygnus Support merged the Motorola and MIT
syntaxes for the 68k, completed support for some COFF targets (68k,
i386 SVR3, and SCO Unix), and made a few other minor patches.

   Steve Chamberlain made `as' able to generate listings.

   Support for the HP9000/300 was contributed by Hewlett-Packard.

   Support for ELF format files has been worked on by Mark Eichin of
Cygnus Support (original, incomplete implementation for SPARC), Pete
Hoogenboom and Jeff Law at the University of Utah (HPPA mainly),
Michael Meissner of the Open Software Foundation (i386 mainly), and Ken
Raeburn of Cygnus Support (sparc, and some initial 64-bit support).

   Several engineers at Cygnus Support have also provided many small
bug fixes and configuration enhancements.

   Many others have contributed large or small bugfixes and
enhancements.  If you've 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 aren't intentionally leaving anyone out.

   ---------- Footnotes ----------

   (1)  Any more details?


File: as,  Node: Copying,  Next: Acknowledgements,  Prev: Machine Dependencies,  Up: Top



GNU GENERAL PUBLIC LICENSE
**************************

                         Version 2, June 1991

     Copyright (C) 1989, 1991 Free Software Foundation, Inc.  675
     Mass Ave, Cambridge, MA 02139, USA

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

Preamble
========

   The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.  This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it.  (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.)  You can apply it to
your programs, too.

   When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it in
new free programs; and that you know you can do these things.

   To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.

   For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
rights.

   We protect your rights with two steps: (1) copyright the software,
and (2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.

   Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software.  If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.

   Finally, any free program is threatened constantly by software
patents.  We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary.  To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.

   The precise terms and conditions for copying, distribution and
modification follow.

    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  1. This License applies to any program or other work which contains a
     notice placed by the copyright holder saying it may be distributed
     under the terms of this General Public License.  The "Program",
     below, refers to any such program or work, and a "work based on
     the Program" means either the Program or any derivative work under
     copyright law: that is to say, a work containing the Program or a
     portion of it, either verbatim or with modifications and/or
     translated into another language.  (Hereinafter, translation is
     included without limitation in the term "modification".)  Each
     licensee is addressed as "you".

     Activities other than copying, distribution and modification are
     not covered by this License; they are outside its scope.  The act
     of running the Program is not restricted, and the output from the
     Program is covered only if its contents constitute a work based on
     the Program (independent of having been made by running the
     Program).  Whether that is true depends on what the Program does.

  2. You may copy and distribute verbatim copies of the Program's
     source code as you receive it, in any medium, provided that you
     conspicuously and appropriately publish on each copy an appropriate
     copyright notice and disclaimer of warranty; keep intact all the
     notices that refer to this License and to the absence of any
     warranty; and give any other recipients of the Program a copy of
     this License along with the Program.

     You may charge a fee for the physical act of transferring a copy,
     and you may at your option offer warranty protection in exchange
     for a fee.

  3. You may modify your copy or copies of the Program or any portion
     of it, thus forming a work based on the Program, and copy and
     distribute such modifications or work under the terms of Section 1
     above, provided that you also meet all of these conditions:

       a. You must cause the modified files to carry prominent notices
          stating that you changed the files and the date of any change.

       b. You must cause any work that you distribute or publish, that
          in whole or in part contains or is derived from the Program
          or any part thereof, to be licensed as a whole at no charge
          to all third parties under the terms of this License.

       c. If the modified program normally reads commands interactively
          when run, you must cause it, when started running for such
          interactive use in the most ordinary way, to print or display
          an announcement including an appropriate copyright notice and
          a notice that there is no warranty (or else, saying that you
          provide a warranty) and that users may redistribute the
          program under these conditions, and telling the user how to
          view a copy of this License.  (Exception: if the Program
          itself is interactive but does not normally print such an
          announcement, your work based on the Program is not required
          to print an announcement.)

     These requirements apply to the modified work as a whole.  If
     identifiable sections of that work are not derived from the
     Program, and can be reasonably considered independent and separate
     works in themselves, then this License, and its terms, do not
     apply to those sections when you distribute them as separate
     works.  But when you distribute the same sections as part of a
     whole which is a work based on the Program, the distribution of
     the whole must be on the terms of this License, whose permissions
     for other licensees extend to the entire whole, and thus to each
     and every part regardless of who wrote it.

     Thus, it is not the intent of this section to claim rights or
     contest your rights to work written entirely by you; rather, the
     intent is to exercise the right to control the distribution of
     derivative or collective works based on the Program.

     In addition, mere aggregation of another work not based on the
     Program with the Program (or with a work based on the Program) on
     a volume of a storage or distribution medium does not bring the
     other work under the scope of this License.

  4. You may copy and distribute the Program (or a work based on it,
     under Section 2) in object code or executable form under the terms
     of Sections 1 and 2 above provided that you also do one of the
     following:

       a. Accompany it with the complete corresponding machine-readable
          source code, which must be distributed under the terms of
          Sections 1 and 2 above on a medium customarily used for
          software interchange; or,

       b. Accompany it with a written offer, valid for at least three
          years, to give any third party, for a charge no more than your
          cost of physically performing source distribution, a complete
          machine-readable copy of the corresponding source code, to be
          distributed under the terms of Sections 1 and 2 above on a
          medium customarily used for software interchange; or,

       c. Accompany it with the information you received as to the offer
          to distribute corresponding source code.  (This alternative is
          allowed only for noncommercial distribution and only if you
          received the program in object code or executable form with
          such an offer, in accord with Subsection b above.)

     The source code for a work means the preferred form of the work for
     making modifications to it.  For an executable work, complete
     source code means all the source code for all modules it contains,
     plus any associated interface definition files, plus the scripts
     used to control compilation and installation of the executable.
     However, as a special exception, the source code distributed need
     not include anything that is normally distributed (in either
     source or binary form) with the major components (compiler,
     kernel, and so on) of the operating system on which the executable
     runs, unless that component itself accompanies the executable.

     If distribution of executable or object code is made by offering
     access to copy from a designated place, then offering equivalent
     access to copy the source code from the same place counts as
     distribution of the source code, even though third parties are not
     compelled to copy the source along with the object code.

  5. You may not copy, modify, sublicense, or distribute the Program
     except as expressly provided under this License.  Any attempt
     otherwise to copy, modify, sublicense or distribute the Program is
     void, and will automatically terminate your rights under this
     License.  However, parties who have received copies, or rights,
     from you under this License will not have their licenses
     terminated so long as such parties remain in full compliance.

  6. You are not required to accept this License, since you have not
     signed it.  However, nothing else grants you permission to modify
     or distribute the Program or its derivative works.  These actions
     are prohibited by law if you do not accept this License.
     Therefore, by modifying or distributing the Program (or any work
     based on the Program), you indicate your acceptance of this
     License to do so, and all its terms and conditions for copying,
     distributing or modifying the Program or works based on it.

  7. Each time you redistribute the Program (or any work based on the
     Program), the recipient automatically receives a license from the
     original licensor to copy, distribute or modify the Program
     subject to these terms and conditions.  You may not impose any
     further restrictions on the recipients' exercise of the rights
     granted herein.  You are not responsible for enforcing compliance
     by third parties to this License.

  8. If, as a consequence of a court judgment or allegation of patent
     infringement or for any other reason (not limited to patent
     issues), conditions are imposed on you (whether by court order,
     agreement or otherwise) that contradict the conditions of this
     License, they do not excuse you from the conditions of this
     License.  If you cannot distribute so as to satisfy simultaneously
     your obligations under this License and any other pertinent
     obligations, then as a consequence you may not distribute the
     Program at all.  For example, if a patent license would not permit
     royalty-free redistribution of the Program by all those who
     receive copies directly or indirectly through you, then the only
     way you could satisfy both it and this License would be to refrain
     entirely from distribution of the Program.

     If any portion of this section is held invalid or unenforceable
     under any particular circumstance, the balance of the section is
     intended to apply and the section as a whole is intended to apply
     in other circumstances.

     It is not the purpose of this section to induce you to infringe any
     patents or other property right claims or to contest validity of
     any such claims; this section has the sole purpose of protecting
     the integrity of the free software distribution system, which is
     implemented by public license practices.  Many people have made
     generous contributions to the wide range of software distributed
     through that system in reliance on consistent application of that
     system; it is up to the author/donor to decide if he or she is
     willing to distribute software through any other system and a
     licensee cannot impose that choice.

     This section is intended to make thoroughly clear what is believed
     to be a consequence of the rest of this License.

  9. If the distribution and/or use of the Program is restricted in
     certain countries either by patents or by copyrighted interfaces,
     the original copyright holder who places the Program under this
     License may add an explicit geographical distribution limitation
     excluding those countries, so that distribution is permitted only
     in or among countries not thus excluded.  In such case, this
     License incorporates the limitation as if written in the body of
     this License.

 10. The Free Software Foundation may publish revised and/or new
     versions of the General Public License from time to time.  Such
     new versions will be similar in spirit to the present version, but
     may differ in detail to address new problems or concerns.

     Each version is given a distinguishing version number.  If the
     Program specifies a version number of this License which applies
     to it and "any later version", you have the option of following
     the terms and conditions either of that version or of any later
     version published by the Free Software Foundation.  If the Program
     does not specify a version number of this License, you may choose
     any version ever published by the Free Software Foundation.

 11. If you wish to incorporate parts of the Program into other free
     programs whose distribution conditions are different, write to the
     author to ask for permission.  For software which is copyrighted
     by the Free Software Foundation, write to the Free Software
     Foundation; we sometimes make exceptions for this.  Our decision
     will be guided by the two goals of preserving the free status of
     all derivatives of our free software and of promoting the sharing
     and reuse of software generally.

                                NO WARRANTY

 12. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
     WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
     LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
     HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
     WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
     NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE
     QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
     PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
     SERVICING, REPAIR OR CORRECTION.

 13. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
     WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
     MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE
     LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
     INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
     INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
     DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU
     OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY
     OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
     ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

                      END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs
=============================================

   If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.

   To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

     ONE LINE TO GIVE THE PROGRAM'S NAME AND AN IDEA OF WHAT IT DOES.
     Copyright (C) 19YY  NAME OF AUTHOR

     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
     as published by the Free Software Foundation; either version 2
     of the License, or (at your option) any later version.

     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

   Also add information on how to contact you by electronic and paper
mail.

   If the program is interactive, make it output a short notice like
this when it starts in an interactive mode:

     Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR
     Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
     type `show w'.  This is free software, and you are welcome
     to redistribute it under certain conditions; type `show c'
     for details.

   The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License.  Of course, the
commands you use may be called something other than `show w' and `show
c'; they could even be mouse-clicks or menu items--whatever suits your
program.

   You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the program,
if necessary.  Here is a sample; alter the names:

     Yoyodyne, Inc., hereby disclaims all copyright
     interest in the program `Gnomovision'
     (which makes passes at compilers) written
     by James Hacker.

     SIGNATURE OF TY COON, 1 April 1989
     Ty Coon, President of Vice

   This General Public License does not permit incorporating your
program into proprietary programs.  If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library.  If this is what you want to do, use the
GNU Library General Public License instead of this License.


File: as,  Node: Index,  Prev: Acknowledgements,  Up: Top

Index
*****

* Menu:

* #:                                    Comments.
* #APP:                                 Pre-processing.
* #NO_APP:                              Pre-processing.
* -:                                    Command Line.
* -a:                                   a.
* -ad:                                  a.
* -ah:                                  a.
* -al:                                  a.
* -an:                                  a.
* -as:                                  a.
* -Asparclite:                          Sparc-Opts.
* -Av6:                                 Sparc-Opts.
* -Av8:                                 Sparc-Opts.
* -D:                                   D.
* -f:                                   f.
* -I PATH:                              I.
* -K:                                   K.
* -L:                                   L.
* -o:                                   o.
* -R:                                   R.
* -v:                                   v.
* -version:                             v.
* -W:                                   W.
* .o:                                   Object.
* 29K support:                          AMD29K-Dependent.
* $ in symbol names:                    SH-Chars.
* $ in symbol names:                    H8/500-Chars.
* -+ option, VAX/VMS:                   Vax-Opts.
* -A options, i960:                     Options-i960.
* -b option, i960:                      Options-i960.
* -D, ignored on VAX:                   Vax-Opts.
* -d, VAX option:                       Vax-Opts.
* -h option, VAX/VMS:                   Vax-Opts.
* -J, ignored on VAX:                   Vax-Opts.
* -l option, M680x0:                    M68K-Opts.
* -m68000 and related options:          M68K-Opts.
* -norelax option, i960:                Options-i960.
* -S, ignored on VAX:                   Vax-Opts.
* -t, ignored on VAX:                   Vax-Opts.
* -T, ignored on VAX:                   Vax-Opts.
* -V, redundant on VAX:                 Vax-Opts.
* . (symbol):                           Dot.
* : (label):                            Statements.
* as version:                           v.
* \" (doublequote character):           Strings.
* \DDD (octal character code):          Strings.
* \\ (\ character):                     Strings.
* \b (backspace character):             Strings.
* \f (formfeed character):              Strings.
* \n (newline character):               Strings.
* \r (carriage return character):       Strings.
* \t (tab):                             Strings.
* a.out symbol attributes:              a.out Symbols.
* ABORT directive:                      ABORT.
* abort directive:                      Abort.
* align directive:                      Align.
* app-file directive:                   App-File.
* ascii directive:                      Ascii.
* asciz directive:                      Asciz.
* block directive, AMD 29K:             AMD29K Directives.
* bss directive, i960:                  Directives-i960.
* byte directive:                       Byte.
* callj, i960 pseudo-opcode:            callj-i960.
* common directive, SPARC:              Sparc-Directives.
* comm directive:                       Comm.
* cputype directive, AMD 29K:           AMD29K Directives.
* data1 directive, M680x0:              M68K-Directives.
* data2 directive, M680x0:              M68K-Directives.
* data directive:                       Data.
* def directive:                        Def.
* desc directive:                       Desc.
* dfloat directive, VAX:                VAX-directives.
* dim directive:                        Dim.
* double directive:                     Double.
* double directive, i386:               i386-Float.
* double directive, M680x0:             M68K-Float.
* double directive, VAX:                VAX-float.
* eject directive:                      Eject.
* else directive:                       Else.
* endef directive:                      Endef.
* endif directive:                      Endif.
* equ directive:                        Equ.
* even directive, M680x0:               M68K-Directives.
* extended directive, i960:             Directives-i960.
* extern directive:                     Extern.
* ffloat directive, VAX:                VAX-directives.
* file directive:                       File.
* file directive, AMD 29K:              AMD29K Directives.
* fill directive:                       Fill.
* float directive:                      Float.
* float directive, i386:                i386-Float.
* float directive, M680x0:              M68K-Float.
* float directive, VAX:                 VAX-float.
* fwait instruction, i386:              i386-Float.
* gbr960, i960 postprocessor:           Options-i960.
* gfloat directive, VAX:                VAX-directives.
* global directive:                     Global.
* half directive, SPARC:                Sparc-Directives.
* hfloat directive, VAX:                VAX-directives.
* hword directive:                      hword.
* ident directive:                      Ident.
* ifdef directive:                      If.
* ifndef directive:                     If.
* ifnotdef directive:                   If.
* if directive:                         If.
* imul instruction, i386:               i386-Notes.
* include directive:                    Include.
* include directive search path:        I.
* int directive:                        Int.
* int directive, H8/300:                H8/300 Directives.
* int directive, H8/500:                H8/500 Directives.
* int directive, i386:                  i386-Float.
* int directive, SH:                    SH Directives.
* lcomm directive:                      Lcomm.
* leafproc directive, i960:             Directives-i960.
* lflags directive (ignored):           Lflags.
* line directive:                       Line.
* line directive, AMD 29K:              AMD29K Directives.
* list directive:                       List.
* ln directive:                         Ln.
* long directive:                       Long.
* long directive, i386:                 i386-Float.
* mul instruction, i386:                i386-Notes.
* nolist directive:                     Nolist.
* octa directive:                       Octa.
* org directive:                        Org.
* proc directive, SPARC:                Sparc-Directives.
* psize directive:                      Psize.
* quad directive:                       Quad.
* quad directive, i386:                 i386-Float.
* reserve directive, SPARC:             Sparc-Directives.
* sbttl directive:                      Sbttl.
* scl directive:                        Scl.
* section directive:                    Section.
* sect directive, AMD 29K:              AMD29K Directives.
* seg directive, SPARC:                 Sparc-Directives.
* set directive:                        Set.
* short directive:                      Short.
* single directive:                     Single.
* single directive, i386:               i386-Float.
* size directive:                       Size.
* skip directive, M680x0:               M68K-Directives.
* skip directive, SPARC:                Sparc-Directives.
* space directive:                      Space.
* stabX directives:                     Stab.
* stabd directive:                      Stab.
* stabn directive:                      Stab.
* stabs directive:                      Stab.
* sysproc directive, i960:              Directives-i960.
* tag directive:                        Tag.
* text directive:                       Text.
* tfloat directive, i386:               i386-Float.
* title directive:                      Title.
* type directive:                       Type.
* use directive, AMD 29K:               AMD29K Directives.
* val directive:                        Val.
* word directive:                       Word.
* word directive, H8/300:               H8/300 Directives.
* word directive, H8/500:               H8/500 Directives.
* word directive, i386:                 i386-Float.
* word directive, SH:                   SH Directives.
* word directive, SPARC:                Sparc-Directives.
* MIT:                                  M68K-Syntax.
* a.out:                                Object.
* absolute section:                     Ld Sections.
* addition, permitted arguments:        Infix Ops.
* addresses:                            Expressions.
* addresses, format of:                 Secs Background.
* addressing modes, H8/300:             H8/300-Addressing.
* addressing modes, H8/500:             H8/500-Addressing.
* addressing modes, M680x0:             M68K-Syntax.
* addressing modes, M680x0:             M68K-Moto-Syntax.
* addressing modes, SH:                 SH-Addressing.
* addressing modes, Z8000:              Z8000-Addressing.
* advancing location counter:           Org.
* altered difference tables:            Word.
* alternate syntax for the 680x0:       M68K-Moto-Syntax.
* AMD 29K floating point (IEEE):        AMD29K Floating Point.
* AMD 29K identifiers:                  AMD29K-Chars.
* AMD 29K line comment character:       AMD29K-Chars.
* AMD 29K line separator:               AMD29K-Chars.
* AMD 29K machine directives:           AMD29K Directives.
* AMD 29K opcodes:                      AMD29K Opcodes.
* AMD 29K options (none):               AMD29K Options.
* AMD 29K protected registers:          AMD29K-Regs.
* AMD 29K register names:               AMD29K-Regs.
* AMD 29K special purpose registers:    AMD29K-Regs.
* AMD 29K statement separator:          AMD29K-Chars.
* AMD 29K support:                      AMD29K-Dependent.
* architecture options, i960:           Options-i960.
* architecture options, M680x0:         M68K-Opts.
* architectures, SPARC:                 Sparc-Opts.
* arguments for addition:               Infix Ops.
* arguments for subtraction:            Infix Ops.
* arguments in expressions:             Arguments.
* arithmetic functions:                 Operators.
* arithmetic operands:                  Arguments.
* assembler internal logic error:       As Sections.
* assembler, and linker:                Secs Background.
* assembly listings, enabling:          a.
* assigning values to symbols:          Equ.
* assigning values to symbols:          Setting Symbols.
* attributes, symbol:                   Symbol Attributes.
* auxiliary attributes, COFF symbols:   COFF Symbols.
* auxiliary symbol information, COFF:   Dim.
* Av7:                                  Sparc-Opts.
* backslash (\\):                       Strings.
* backspace (\b):                       Strings.
* bignums:                              Bignums.
* binary integers:                      Integers.
* bitfields, not supported on VAX:      VAX-no.
* block:                                Z8000 Directives.
* branch improvement, M680x0:           M68K-Branch.
* branch improvement, VAX:              VAX-branch.
* branch recording, i960:               Options-i960.
* branch statistics table, i960:        Options-i960.
* bss section:                          bss.
* bss section:                          Ld Sections.
* bus lock prefixes, i386:              i386-prefixes.
* bval:                                 Z8000 Directives.
* call instructions, i386:              i386-Opcodes.
* carriage return (\r):                 Strings.
* character constants:                  Characters.
* character escape codes:               Strings.
* character, single:                    Chars.
* characters used in symbols:           Symbol Intro.
* COFF auxiliary symbol information:    Dim.
* COFF named section:                   Section.
* COFF structure debugging:             Tag.
* COFF symbol attributes:               COFF Symbols.
* COFF symbol descriptor:               Desc.
* COFF symbol storage class:            Scl.
* COFF symbol type:                     Type.
* COFF symbols, debugging:              Def.
* COFF value attribute:                 Val.
* command line conventions:             Command Line.
* command-line options ignored, VAX:    Vax-Opts.
* comments:                             Comments.
* comments, M680x0:                     M68K-Chars.
* comments, removed by preprocessor:    Pre-processing.
* common variable storage:              bss.
* compare and jump expansions, i960:    Compare-and-branch-i960.
* compare/branch instructions, i960:    Compare-and-branch-i960.
* conditional assembly:                 If.
* constant, single character:           Chars.
* constants:                            Constants.
* constants, bignum:                    Bignums.
* constants, character:                 Characters.
* constants, converted by preprocessor: Pre-processing.
* constants, floating point:            Flonums.
* constants, integer:                   Integers.
* constants, number:                    Numbers.
* constants, string:                    Strings.
* continuing statements:                Statements.
* conversion instructions, i386:        i386-Opcodes.
* coprocessor wait, i386:               i386-prefixes.
* current address:                      Dot.
* current address, advancing:           Org.
* data and text sections, joining:      R.
* data section:                         Ld Sections.
* debuggers, and symbol order:          Symbols.
* debugging COFF symbols:               Def.
* decimal integers:                     Integers.
* deprecated directives:                Deprecated.
* descriptor, of a.out symbol:          Symbol Desc.
* difference tables altered:            Word.
* difference tables, warning:           K.
* directives and instructions:          Statements.
* directives, M680x0:                   M68K-Directives.
* directives, machine independent:      Pseudo Ops.
* directives, Z8000:                    Z8000 Directives.
* displacement sizing character, VAX:   VAX-operands.
* dot (symbol):                         Dot.
* doublequote (\"):                     Strings.
* eight-byte integer:                   Quad.
* empty expressions:                    Empty Exprs.
* EOF, newline must precede:            Statements.
* error messsages:                      Errors.
* escape codes, character:              Strings.
* even:                                 Z8000 Directives.
* expr (internal section):              As Sections.
* expression arguments:                 Arguments.
* expressions:                          Expressions.
* expressions, empty:                   Empty Exprs.
* expressions, integer:                 Integer Exprs.
* faster processing (-f):               f.
* file name, logical:                   App-File.
* file name, logical:                   File.
* files, including:                     Include.
* files, input:                         Input Files.
* filling memory:                       Space.
* floating point numbers:               Flonums.
* floating point numbers (double):      Double.
* floating point numbers (single):      Single.
* floating point numbers (single):      Float.
* floating point, AMD 29K (IEEE):       AMD29K Floating Point.
* floating point, H8/300 (IEEE):        H8/300 Floating Point.
* floating point, H8/500 (IEEE):        H8/500 Floating Point.
* floating point, i386:                 i386-Float.
* floating point, i960 (IEEE):          Floating Point-i960.
* floating point, M680x0:               M68K-Float.
* floating point, SH (IEEE):            SH Floating Point.
* floating point, SPARC (IEEE):         Sparc-Float.
* floating point, VAX:                  VAX-float.
* flonums:                              Flonums.
* format of error messages:             Errors.
* format of warning messages:           Errors.
* formfeed (\f):                        Strings.
* functions, in expressions:            Operators.
* global:                               Z8000 Directives.
* grouping data:                        Sub-Sections.
* H8/300 addressing modes:              H8/300-Addressing.
* H8/300 floating point (IEEE):         H8/300 Floating Point.
* H8/300 line comment character:        H8/300-Chars.
* H8/300 line separator:                H8/300-Chars.
* H8/300 machine directives (none):     H8/300 Directives.
* H8/300 opcode summary:                H8/300 Opcodes.
* H8/300 options (none):                H8/300 Options.
* H8/300 registers:                     H8/300-Regs.
* H8/300 size suffixes:                 H8/300 Opcodes.
* H8/300 support:                       H8/300-Dependent.
* H8/300H, assembling for:              H8/300 Directives.
* H8/500 addressing modes:              H8/500-Addressing.
* H8/500 floating point (IEEE):         H8/500 Floating Point.
* H8/500 line comment character:        H8/500-Chars.
* H8/500 line separator:                H8/500-Chars.
* H8/500 machine directives (none):     H8/500 Directives.
* H8/500 opcode summary:                H8/500 Opcodes.
* H8/500 options (none):                H8/500 Options.
* H8/500 registers:                     H8/500-Regs.
* H8/500 support:                       H8/500-Dependent.
* hexadecimal integers:                 Integers.
* i386 fwait instruction:               i386-Float.
* i386 mul, imul instructions:          i386-Notes.
* i386 conversion instructions:         i386-Opcodes.
* i386 floating point:                  i386-Float.
* i386 immediate operands:              i386-Syntax.
* i386 jump optimization:               i386-jumps.
* i386 jump, call, return:              i386-Syntax.
* i386 jump/call operands:              i386-Syntax.
* i386 memory references:               i386-Memory.
* i386 opcode naming:                   i386-Opcodes.
* i386 opcode prefixes:                 i386-prefixes.
* i386 options (none):                  i386-Options.
* i386 register operands:               i386-Syntax.
* i386 registers:                       i386-Regs.
* i386 sections:                        i386-Syntax.
* i386 size suffixes:                   i386-Syntax.
* i386 source, destination operands:    i386-Syntax.
* i386 support:                         i386-Dependent.
* i386 syntax compatibility:            i386-Syntax.
* i80306 support:                       i386-Dependent.
* i960 callj pseudo-opcode:             callj-i960.
* i960 architecture options:            Options-i960.
* i960 branch recording:                Options-i960.
* i960 compare and jump expansions:     Compare-and-branch-i960.
* i960 compare/branch instructions:     Compare-and-branch-i960.
* i960 floating point (IEEE):           Floating Point-i960.
* i960 machine directives:              Directives-i960.
* i960 opcodes:                         Opcodes for i960.
* i960 options:                         Options-i960.
* i960 support:                         i960-Dependent.
* identifiers, AMD 29K:                 AMD29K-Chars.
* immediate character, M680x0:          M68K-Chars.
* immediate character, VAX:             VAX-operands.
* immediate operands, i386:             i386-Syntax.
* indirect character, VAX:              VAX-operands.
* infix operators:                      Infix Ops.
* inhibiting interrupts, i386:          i386-prefixes.
* input:                                Input Files.
* input file linenumbers:               Input Files.
* instruction set, M680x0:              M68K-opcodes.
* instruction summary, H8/300:          H8/300 Opcodes.
* instruction summary, H8/500:          H8/500 Opcodes.
* instruction summary, SH:              SH Opcodes.
* instruction summary, Z8000:           Z8000 Opcodes.
* instructions and directives:          Statements.
* integer expressions:                  Integer Exprs.
* integer, 16-byte:                     Octa.
* integer, 8-byte:                      Quad.
* integers:                             Integers.
* integers, 16-bit:                     hword.
* integers, 32-bit:                     Int.
* integers, binary:                     Integers.
* integers, decimal:                    Integers.
* integers, hexadecimal:                Integers.
* integers, octal:                      Integers.
* integers, one byte:                   Byte.
* internal as sections:                 As Sections.
* invocation summary:                   Overview.
* joining text and data sections:       R.
* jump instructions, i386:              i386-Opcodes.
* jump optimization, i386:              i386-jumps.
* jump/call operands, i386:             i386-Syntax.
* label (:):                            Statements.
* labels:                               Labels.
* ld:                                   Object.
* length of symbols:                    Symbol Intro.
* line comment character:               Comments.
* line comment character, AMD 29K:      AMD29K-Chars.
* line comment character, H8/300:       H8/300-Chars.
* line comment character, H8/500:       H8/500-Chars.
* line comment character, M680x0:       M68K-Chars.
* line comment character, SH:           SH-Chars.
* line comment character, Z8000:        Z8000-Chars.
* line numbers, in input files:         Input Files.
* line numbers, in warnings/errors:     Errors.
* line separator character:             Statements.
* line separator, AMD 29K:              AMD29K-Chars.
* line separator, H8/300:               H8/300-Chars.
* line separator, H8/500:               H8/500-Chars.
* line separator, SH:                   SH-Chars.
* line separator, Z8000:                Z8000-Chars.
* lines starting with #:                Comments.
* linker:                               Object.
* linker, and assembler:                Secs Background.
* listing control, turning off:         Nolist.
* listing control, turning on:          List.
* listing control: new page:            Eject.
* listing control: paper size:          Psize.
* listing control: subtitle:            Sbttl.
* listing control: title line:          Title.
* listings, enabling:                   a.
* local common symbols:                 Lcomm.
* local labels, retaining in output:    L.
* local symbol names:                   Symbol Names.
* location counter:                     Dot.
* location counter, advancing:          Org.
* logical file name:                    File.
* logical file name:                    App-File.
* logical line number:                  Line.
* logical line numbers:                 Comments.
* lval:                                 Z8000 Directives.
* M680x0 addressing modes:              M68K-Moto-Syntax.
* M680x0 addressing modes:              M68K-Syntax.
* M680x0 architecture options:          M68K-Opts.
* M680x0 branch improvement:            M68K-Branch.
* M680x0 directives:                    M68K-Directives.
* M680x0 floating point:                M68K-Float.
* M680x0 immediate character:           M68K-Chars.
* M680x0 line comment character:        M68K-Chars.
* M680x0 opcodes:                       M68K-opcodes.
* M680x0 options:                       M68K-Opts.
* M680x0 pseudo-opcodes:                M68K-Branch.
* M680x0 size modifiers:                M68K-Syntax.
* M680x0 support:                       M68K-Dependent.
* M680x0 syntax:                        M68K-Moto-Syntax.
* M680x0 syntax:                        M68K-Syntax.
* machine dependencies:                 Machine Dependencies.
* machine directives, AMD 29K:          AMD29K Directives.
* machine directives, H8/300 (none):    H8/300 Directives.
* machine directives, H8/500 (none):    H8/500 Directives.
* machine directives, i960:             Directives-i960.
* machine directives, SH (none):        SH Directives.
* machine directives, SPARC:            Sparc-Directives.
* machine directives, VAX:              VAX-directives.
* machine independent directives:       Pseudo Ops.
* machine instructions (not covered):   Manual.
* machine-independent syntax:           Syntax.
* manual, structure and purpose:        Manual.
* memory references, i386:              i386-Memory.
* merging text and data sections:       R.
* messages from as:                     Errors.
* minus, permitted arguments:           Infix Ops.
* mnemonics for opcodes, VAX:           VAX-opcodes.
* mnemonics, H8/300:                    H8/300 Opcodes.
* mnemonics, H8/500:                    H8/500 Opcodes.
* mnemonics, SH:                        SH Opcodes.
* mnemonics, Z8000:                     Z8000 Opcodes.
* Motorola syntax for the 680x0:        M68K-Moto-Syntax.
* multi-line statements:                Statements.
* name:                                 Z8000 Directives.
* named section (COFF):                 Section.
* named sections:                       Ld Sections.
* names, symbol:                        Symbol Names.
* naming object file:                   o.
* new page, in listings:                Eject.
* newline (\n):                         Strings.
* newline, required at file end:        Statements.
* null-terminated strings:              Asciz.
* number constants:                     Numbers.
* numbered subsections:                 Sub-Sections.
* numbers, 16-bit:                      hword.
* numeric values:                       Expressions.
* object file:                          Object.
* object file format:                   Object Formats.
* object file name:                     o.
* obsolescent directives:               Deprecated.
* octal character code (\DDD):          Strings.
* octal integers:                       Integers.
* opcode mnemonics, VAX:                VAX-opcodes.
* opcode naming, i386:                  i386-Opcodes.
* opcode prefixes, i386:                i386-prefixes.
* opcode suffixes, i386:                i386-Syntax.
* opcode summary, H8/300:               H8/300 Opcodes.
* opcode summary, H8/500:               H8/500 Opcodes.
* opcode summary, SH:                   SH Opcodes.
* opcode summary, Z8000:                Z8000 Opcodes.
* opcodes for AMD 29K:                  AMD29K Opcodes.
* opcodes, i960:                        Opcodes for i960.
* opcodes, M680x0:                      M68K-opcodes.
* operand delimiters, i386:             i386-Syntax.
* operand notation, VAX:                VAX-operands.
* operands in expressions:              Arguments.
* operator precedence:                  Infix Ops.
* operators, in expressions:            Operators.
* operators, permitted arguments:       Infix Ops.
* option summary:                       Overview.
* options for AMD29K (none):            AMD29K Options.
* options for i386 (none):              i386-Options.
* options for SPARC:                    Sparc-Opts.
* options for VAX/VMS:                  Vax-Opts.
* options, all versions of as:          Invoking.
* options, command line:                Command Line.
* options, H8/300 (none):               H8/300 Options.
* options, H8/500 (none):               H8/500 Options.
* options, i960:                        Options-i960.
* options, M680x0:                      M68K-Opts.
* options, SH (none):                   SH Options.
* options, Z8000:                       Z8000 Options.
* other attribute, of a.out symbol:     Symbol Other.
* output file:                          Object.
* padding the location counter:         Align.
* page, in listings:                    Eject.
* paper size, for listings:             Psize.
* paths for .include:                   I.
* patterns, writing in memory:          Fill.
* plus, permitted arguments:            Infix Ops.
* precedence of operators:              Infix Ops.
* precision, floating point:            Flonums.
* prefix operators:                     Prefix Ops.
* prefixes, i386:                       i386-prefixes.
* preprocessing:                        Pre-processing.
* preprocessing, turning on and off:    Pre-processing.
* primary attributes, COFF symbols:     COFF Symbols.
* protected registers, AMD 29K:         AMD29K-Regs.
* pseudo-opcodes, M680x0:               M68K-Branch.
* pseudo-ops for branch, VAX:           VAX-branch.
* pseudo-ops, machine independent:      Pseudo Ops.
* purpose of GNU as:                    GNU Assembler.
* register names, AMD 29K:              AMD29K-Regs.
* register names, H8/300:               H8/300-Regs.
* register names, VAX:                  VAX-operands.
* register operands, i386:              i386-Syntax.
* registers, H8/500:                    H8/500-Regs.
* registers, i386:                      i386-Regs.
* registers, SH:                        SH-Regs.
* registers, Z8000:                     Z8000-Regs.
* relocation:                           Sections.
* relocation example:                   Ld Sections.
* repeat prefixes, i386:                i386-prefixes.
* return instructions, i386:            i386-Syntax.
* rsect:                                Z8000 Directives.
* search path for .include:             I.
* section override prefixes, i386:      i386-prefixes.
* section-relative addressing:          Secs Background.
* sections:                             Sections.
* sections in messages, internal:       As Sections.
* sections, i386:                       i386-Syntax.
* sections, named:                      Ld Sections.
* segm:                                 Z8000 Directives.
* SH addressing modes:                  SH-Addressing.
* SH floating point (IEEE):             SH Floating Point.
* SH line comment character:            SH-Chars.
* SH line separator:                    SH-Chars.
* SH machine directives (none):         SH Directives.
* SH opcode summary:                    SH Opcodes.
* SH options (none):                    SH Options.
* SH registers:                         SH-Regs.
* SH support:                           SH-Dependent.
* single character constant:            Chars.
* sixteen bit integers:                 hword.
* sixteen byte integer:                 Octa.
* size modifiers, M680x0:               M68K-Syntax.
* size prefixes, i386:                  i386-prefixes.
* size suffixes, H8/300:                H8/300 Opcodes.
* sizes operands, i386:                 i386-Syntax.
* source program:                       Input Files.
* source, destination operands; i386:   i386-Syntax.
* SPARC architectures:                  Sparc-Opts.
* SPARC floating point (IEEE):          Sparc-Float.
* SPARC machine directives:             Sparc-Directives.
* SPARC options:                        Sparc-Opts.
* SPARC support:                        Sparc-Dependent.
* special characters, M680x0:           M68K-Chars.
* special purpose registers, AMD 29K:   AMD29K-Regs.
* standard as sections:                 Secs Background.
* standard input, as input file:        Command Line.
* statement on multiple lines:          Statements.
* statement separator character:        Statements.
* statement separator, AMD 29K:         AMD29K-Chars.
* statement separator, H8/300:          H8/300-Chars.
* statement separator, H8/500:          H8/500-Chars.
* statement separator, SH:              SH-Chars.
* statement separator, Z8000:           Z8000-Chars.
* statements, structure of:             Statements.
* stopping the assembly:                Abort.
* string constants:                     Strings.
* string literals:                      Ascii.
* structure debugging, COFF:            Tag.
* subexpressions:                       Arguments.
* subtitles for listings:               Sbttl.
* subtraction, permitted arguments:     Infix Ops.
* summary of options:                   Overview.
* supporting files, including:          Include.
* suppressing warnings:                 W.
* sval:                                 Z8000 Directives.
* symbol attributes:                    Symbol Attributes.
* symbol attributes, a.out:             a.out Symbols.
* symbol attributes, COFF:              COFF Symbols.
* symbol descriptor, COFF:              Desc.
* symbol names:                         Symbol Names.
* symbol names, $ in:                   SH-Chars.
* symbol names, $ in:                   H8/500-Chars.
* symbol names, local:                  Symbol Names.
* symbol names, temporary:              Symbol Names.
* symbol storage class (COFF):          Scl.
* symbol type:                          Symbol Type.
* symbol type, COFF:                    Type.
* symbol value:                         Symbol Value.
* symbol value, setting:                Set.
* symbol values, assigning:             Setting Symbols.
* symbol, common:                       Comm.
* symbol, making visible to linker:     Global.
* symbolic debuggers, information for:  Stab.
* symbols:                              Symbols.
* symbols with lowercase, VAX/VMS:      Vax-Opts.
* symbols, assigning values to:         Equ.
* symbols, local common:                Lcomm.
* syntax compatibility, i386:           i386-Syntax.
* syntax, M680x0:                       M68K-Syntax.
* syntax, M680x0:                       M68K-Moto-Syntax.
* syntax, machine-independent:          Syntax.
* tab (\t):                             Strings.
* temporary symbol names:               Symbol Names.
* text and data sections, joining:      R.
* text section:                         Ld Sections.
* trusted compiler:                     f.
* turning preprocessing on and off:     Pre-processing.
* type of a symbol:                     Symbol Type.
* undefined section:                    Ld Sections.
* unsegm:                               Z8000 Directives.
* value attribute, COFF:                Val.
* value of a symbol:                    Symbol Value.
* VAX bitfields not supported:          VAX-no.
* VAX branch improvement:               VAX-branch.
* VAX command-line options ignored:     Vax-Opts.
* VAX displacement sizing character:    VAX-operands.
* VAX floating point:                   VAX-float.
* VAX immediate character:              VAX-operands.
* VAX indirect character:               VAX-operands.
* VAX machine directives:               VAX-directives.
* VAX opcode mnemonics:                 VAX-opcodes.
* VAX operand notation:                 VAX-operands.
* VAX register names:                   VAX-operands.
* VAX support:                          Vax-Dependent.
* Vax-11 C compatibility:               Vax-Opts.
* VAX/VMS options:                      Vax-Opts.
* version of as:                        v.
* VMS (VAX) options:                    Vax-Opts.
* warning for altered difference tables: K.
* warning messages:                     Errors.
* warnings, suppressing:                W.
* whitespace:                           Whitespace.
* whitespace, removed by preprocessor:  Pre-processing.
* wide floating point directives, VAX:  VAX-directives.
* writing patterns in memory:           Fill.
* wval:                                 Z8000 Directives.
* Z800 addressing modes:                Z8000-Addressing.
* Z8000 directives:                     Z8000 Directives.
* Z8000 line comment character:         Z8000-Chars.
* Z8000 line separator:                 Z8000-Chars.
* Z8000 opcode summary:                 Z8000 Opcodes.
* Z8000 options:                        Z8000 Options.
* Z8000 registers:                      Z8000-Regs.
* Z8000 support:                        Z8000-Dependent.
* zero-terminated strings:              Asciz.



Tag Table:
Node: Top1138
Node: Overview1821
Node: Manual5499
Node: GNU Assembler6433
Node: Object Formats7603
Node: Command Line8045
Node: Input Files9122
Node: Object11025
Node: Errors11965
Node: Invoking13157
Node: a14483
Node: D15575
Node: f15795
Node: I16295
Node: K16832
Node: L17126
Node: o17776
Node: R18222
Node: v19125
Node: W19371
Node: Syntax19938
Node: Pre-processing20525
Node: Whitespace21988
Node: Comments22374
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Node: Statements24857
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Node: Characters27528
Node: Strings28016
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Node: Symbol Desc52584
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Node: Vax-Dependent89433
Node: Vax-Opts89936
Node: VAX-float92213
Node: VAX-directives92829
Node: VAX-opcodes93673
Node: VAX-branch94046
Node: VAX-operands96542
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Node: AMD29K-Dependent97494
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Node: H8/300 Directives105161
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Node: H8/500-Dependent114023
Node: H8/500 Options114420
Node: H8/500 Syntax114596
Node: H8/500-Chars114878
Node: H8/500-Regs115164
Node: H8/500-Addressing115915
Node: H8/500 Floating Point116527
Node: H8/500 Directives116727
Node: H8/500 Opcodes117041
Node: SH-Dependent122149
Node: SH Options122528
Node: SH Syntax122688
Node: SH-Chars122942
Node: SH-Regs123216
Node: SH-Addressing123810
Node: SH Floating Point124699
Node: SH Directives124879
Node: SH Opcodes125079
Node: i960-Dependent129321
Node: Options-i960129706
Node: Floating Point-i960133587
Node: Directives-i960133839
Node: Opcodes for i960135854
Node: callj-i960136455
Node: Compare-and-branch-i960136933
Node: M68K-Dependent138815
Node: M68K-Opts139265
Node: M68K-Syntax140599
Node: M68K-Moto-Syntax142424
Node: M68K-Float143913
Node: M68K-Directives144694
Node: M68K-opcodes145227
Node: M68K-Branch145434
Node: M68K-Chars148257
Node: Sparc-Dependent148607
Node: Sparc-Opts148922
Node: Sparc-Float149851
Node: Sparc-Directives150028
Node: i386-Dependent151073
Node: i386-Options151663
Node: i386-Syntax151802
Node: i386-Opcodes153747
Node: i386-Regs155861
Node: i386-prefixes156997
Node: i386-Memory158661
Node: i386-jumps160934
Node: i386-Float162045
Node: i386-Notes164030
Node: Z8000-Dependent164866
Node: Z8000 Options165826
Node: Z8000 Syntax165996
Node: Z8000-Chars166267
Node: Z8000-Regs166480
Node: Z8000-Addressing167247
Node: Z8000 Directives168185
Node: Z8000 Opcodes169738
Node: Acknowledgements179669
Node: Copying183799
Node: Index202971

End Tag Table