You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
162 lines
8.8 KiB
HTML
162 lines
8.8 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- This file documents the GNU Assembler "as".
|
|
|
|
Copyright (C) 1991-2019 Free Software Foundation, Inc.
|
|
|
|
Permission is granted to copy, distribute and/or modify this document
|
|
under the terms of the GNU Free Documentation License, Version 1.3
|
|
or any later version published by the Free Software Foundation;
|
|
with no Invariant Sections, with no Front-Cover Texts, and with no
|
|
Back-Cover Texts. A copy of the license is included in the
|
|
section entitled "GNU Free Documentation License".
|
|
-->
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>MMIX-Opts (Using as)</title>
|
|
|
|
<meta name="description" content="MMIX-Opts (Using as)">
|
|
<meta name="keywords" content="MMIX-Opts (Using as)">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<link href="index.html#Top" rel="start" title="Top">
|
|
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="MMIX_002dDependent.html#MMIX_002dDependent" rel="up" title="MMIX-Dependent">
|
|
<link href="MMIX_002dExpand.html#MMIX_002dExpand" rel="next" title="MMIX-Expand">
|
|
<link href="MMIX_002dDependent.html#MMIX_002dDependent" rel="prev" title="MMIX-Dependent">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
|
blockquote.smallquotation {font-size: smaller}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
div.smalldisplay {margin-left: 3.2em}
|
|
div.smallexample {margin-left: 3.2em}
|
|
div.smalllisp {margin-left: 3.2em}
|
|
kbd {font-style: oblique}
|
|
pre.display {font-family: inherit}
|
|
pre.format {font-family: inherit}
|
|
pre.menu-comment {font-family: serif}
|
|
pre.menu-preformatted {font-family: serif}
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
|
pre.smallexample {font-size: smaller}
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
|
pre.smalllisp {font-size: smaller}
|
|
span.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<a name="MMIX_002dOpts"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="MMIX_002dExpand.html#MMIX_002dExpand" accesskey="n" rel="next">MMIX-Expand</a>, Up: <a href="MMIX_002dDependent.html#MMIX_002dDependent" accesskey="u" rel="up">MMIX-Dependent</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
<hr>
|
|
<a name="Command_002dline-Options-1"></a>
|
|
<h4 class="subsection">9.27.1 Command-line Options</h4>
|
|
|
|
<a name="index-options_002c-MMIX"></a>
|
|
<a name="index-MMIX-options"></a>
|
|
<p>The MMIX version of <code>as</code> has some machine-dependent options.
|
|
</p>
|
|
<a name="index-_002d_002dfixed_002dspecial_002dregister_002dnames-command_002dline-option_002c-MMIX"></a>
|
|
<p>When ‘<samp>--fixed-special-register-names</samp>’ is specified, only the register
|
|
names specified in <a href="MMIX_002dRegs.html#MMIX_002dRegs">MMIX-Regs</a> are recognized in the instructions
|
|
<code>PUT</code> and <code>GET</code>.
|
|
</p>
|
|
<a name="index-_002d_002dglobalize_002dsymbols-command_002dline-option_002c-MMIX"></a>
|
|
<p>You can use the ‘<samp>--globalize-symbols</samp>’ to make all symbols global.
|
|
This option is useful when splitting up a <code>mmixal</code> program into
|
|
several files.
|
|
</p>
|
|
<a name="index-_002d_002dgnu_002dsyntax-command_002dline-option_002c-MMIX"></a>
|
|
<p>The ‘<samp>--gnu-syntax</samp>’ turns off most syntax compatibility with
|
|
<code>mmixal</code>. Its usability is currently doubtful.
|
|
</p>
|
|
<a name="index-_002d_002drelax-command_002dline-option_002c-MMIX"></a>
|
|
<p>The ‘<samp>--relax</samp>’ option is not fully supported, but will eventually make
|
|
the object file prepared for linker relaxation.
|
|
</p>
|
|
<a name="index-_002d_002dno_002dpredefined_002dsyms-command_002dline-option_002c-MMIX"></a>
|
|
<p>If you want to avoid inadvertently calling a predefined symbol and would
|
|
rather get an error, for example when using <code>as</code> with a
|
|
compiler or other machine-generated code, specify
|
|
‘<samp>--no-predefined-syms</samp>’. This turns off built-in predefined
|
|
definitions of all such symbols, including rounding-mode symbols, segment
|
|
symbols, ‘<samp>BIT</samp>’ symbols, and <code>TRAP</code> symbols used in <code>mmix</code>
|
|
“system calls”. It also turns off predefined special-register names,
|
|
except when used in <code>PUT</code> and <code>GET</code> instructions.
|
|
</p>
|
|
<a name="index-_002d_002dno_002dexpand-command_002dline-option_002c-MMIX"></a>
|
|
<p>By default, some instructions are expanded to fit the size of the operand
|
|
or an external symbol (see <a href="MMIX_002dExpand.html#MMIX_002dExpand">MMIX-Expand</a>). By passing
|
|
‘<samp>--no-expand</samp>’, no such expansion will be done, instead causing errors
|
|
at link time if the operand does not fit.
|
|
</p>
|
|
<a name="index-_002d_002dno_002dmerge_002dgregs-command_002dline-option_002c-MMIX"></a>
|
|
<p>The <code>mmixal</code> documentation (see <a href="MMIX_002dSyntax.html#mmixsite">mmixsite</a>) specifies that global
|
|
registers allocated with the ‘<samp>GREG</samp>’ directive (see <a href="MMIX_002dPseudos.html#MMIX_002dgreg">MMIX-greg</a>) and
|
|
initialized to the same non-zero value, will refer to the same global
|
|
register. This isn’t strictly enforceable in <code>as</code> since the
|
|
final addresses aren’t known until link-time, but it will do an effort
|
|
unless the ‘<samp>--no-merge-gregs</samp>’ option is specified. (Register merging
|
|
isn’t yet implemented in <code>ld</code>.)
|
|
</p>
|
|
<a name="index-_002dx-command_002dline-option_002c-MMIX"></a>
|
|
<p><code>as</code> will warn every time it expands an instruction to fit an
|
|
operand unless the option ‘<samp>-x</samp>’ is specified. It is believed that
|
|
this behaviour is more useful than just mimicking <code>mmixal</code>’s
|
|
behaviour, in which instructions are only expanded if the ‘<samp>-x</samp>’ option
|
|
is specified, and assembly fails otherwise, when an instruction needs to
|
|
be expanded. It needs to be kept in mind that <code>mmixal</code> is both an
|
|
assembler and linker, while <code>as</code> will expand instructions
|
|
that at link stage can be contracted. (Though linker relaxation isn’t yet
|
|
implemented in <code>ld</code>.) The option ‘<samp>-x</samp>’ also implies
|
|
‘<samp>--linker-allocated-gregs</samp>’.
|
|
</p>
|
|
<a name="index-_002d_002dno_002dpushj_002dstubs-command_002dline-option_002c-MMIX"></a>
|
|
<a name="index-_002d_002dno_002dstubs-command_002dline-option_002c-MMIX"></a>
|
|
<p>If instruction expansion is enabled, <code>as</code> can expand a
|
|
‘<samp>PUSHJ</samp>’ instruction into a series of instructions. The shortest
|
|
expansion is to not expand it, but just mark the call as redirectable to a
|
|
stub, which <code>ld</code> creates at link-time, but only if the
|
|
original ‘<samp>PUSHJ</samp>’ instruction is found not to reach the target. The
|
|
stub consists of the necessary instructions to form a jump to the target.
|
|
This happens if <code>as</code> can assert that the ‘<samp>PUSHJ</samp>’
|
|
instruction can reach such a stub. The option ‘<samp>--no-pushj-stubs</samp>’
|
|
disables this shorter expansion, and the longer series of instructions is
|
|
then created at assembly-time. The option ‘<samp>--no-stubs</samp>’ is a synonym,
|
|
intended for compatibility with future releases, where generation of stubs
|
|
for other instructions may be implemented.
|
|
</p>
|
|
<a name="index-_002d_002dlinker_002dallocated_002dgregs-command_002dline-option_002c-MMIX"></a>
|
|
<p>Usually a two-operand-expression (see <a href="MMIX_002dPseudos.html#GREG_002dbase">GREG-base</a>) without a matching
|
|
‘<samp>GREG</samp>’ directive is treated as an error by <code>as</code>. When
|
|
the option ‘<samp>--linker-allocated-gregs</samp>’ is in effect, they are instead
|
|
passed through to the linker, which will allocate as many global registers
|
|
as is needed.
|
|
</p>
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="MMIX_002dExpand.html#MMIX_002dExpand" accesskey="n" rel="next">MMIX-Expand</a>, Up: <a href="MMIX_002dDependent.html#MMIX_002dDependent" accesskey="u" rel="up">MMIX-Dependent</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|