181 lines
9.0 KiB
HTML
181 lines
9.0 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) 1991-2016 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 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Using as: Xtensa Options</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Using as: Xtensa Options">
|
||
|
|
<meta name="keywords" content="Using as: Xtensa Options">
|
||
|
|
<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="Xtensa_002dDependent.html#Xtensa_002dDependent" rel="up" title="Xtensa-Dependent">
|
||
|
|
<link href="Xtensa-Syntax.html#Xtensa-Syntax" rel="next" title="Xtensa Syntax">
|
||
|
|
<link href="Xtensa_002dDependent.html#Xtensa_002dDependent" rel="prev" title="Xtensa-Dependent">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.indentedblock {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
||
|
|
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.nocodebreak {white-space:nowrap}
|
||
|
|
span.nolinebreak {white-space:nowrap}
|
||
|
|
span.roman {font-family:serif; font-weight:normal}
|
||
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
||
|
|
<a name="Xtensa-Options"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Xtensa-Syntax.html#Xtensa-Syntax" accesskey="n" rel="next">Xtensa Syntax</a>, Up: <a href="Xtensa_002dDependent.html#Xtensa_002dDependent" accesskey="u" rel="up">Xtensa-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-Line-Options"></a>
|
||
|
|
<h4 class="subsection">9.52.1 Command Line Options</h4>
|
||
|
|
|
||
|
|
<dl compact="compact">
|
||
|
|
<dt><code>--text-section-literals | --no-text-section-literals</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dtext_002dsection_002dliterals"></a>
|
||
|
|
<a name="index-_002d_002dno_002dtext_002dsection_002dliterals"></a>
|
||
|
|
<p>Control the treatment of literal pools. The default is
|
||
|
|
‘<samp>--no-text-section-literals</samp>’, which places literals in
|
||
|
|
separate sections in the output file. This allows the literal pool to be
|
||
|
|
placed in a data RAM/ROM. With ‘<samp>--text-section-literals</samp>’, the
|
||
|
|
literals are interspersed in the text section in order to keep them as
|
||
|
|
close as possible to their references. This may be necessary for large
|
||
|
|
assembly files, where the literals would otherwise be out of range of the
|
||
|
|
<code>L32R</code> instructions in the text section. Literals are grouped into
|
||
|
|
pools following <code>.literal_position</code> directives or preceding
|
||
|
|
<code>ENTRY</code> instructions. These options only affect literals referenced
|
||
|
|
via PC-relative <code>L32R</code> instructions; literals for absolute mode
|
||
|
|
<code>L32R</code> instructions are handled separately.
|
||
|
|
See <a href="Literal-Directive.html#Literal-Directive">literal</a>.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--auto-litpools | --no-auto-litpools</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dauto_002dlitpools"></a>
|
||
|
|
<a name="index-_002d_002dno_002dauto_002dlitpools"></a>
|
||
|
|
<p>Control the treatment of literal pools. The default is
|
||
|
|
‘<samp>--no-auto-litpools</samp>’, which in the absence of
|
||
|
|
‘<samp>--text-section-literals</samp>’ places literals in separate sections
|
||
|
|
in the output file. This allows the literal pool to be placed in a data
|
||
|
|
RAM/ROM. With ‘<samp>--auto-litpools</samp>’, the literals are interspersed
|
||
|
|
in the text section in order to keep them as close as possible to their
|
||
|
|
references, explicit <code>.literal_position</code> directives are not
|
||
|
|
required. This may be necessary for very large functions, where single
|
||
|
|
literal pool at the beginning of the function may not be reachable by
|
||
|
|
<code>L32R</code> instructions at the end. These options only affect
|
||
|
|
literals referenced via PC-relative <code>L32R</code> instructions; literals
|
||
|
|
for absolute mode <code>L32R</code> instructions are handled separately.
|
||
|
|
When used together with ‘<samp>--text-section-literals</samp>’,
|
||
|
|
‘<samp>--auto-litpools</samp>’ takes precedence.
|
||
|
|
See <a href="Literal-Directive.html#Literal-Directive">literal</a>.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--absolute-literals | --no-absolute-literals</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dabsolute_002dliterals"></a>
|
||
|
|
<a name="index-_002d_002dno_002dabsolute_002dliterals"></a>
|
||
|
|
<p>Indicate to the assembler whether <code>L32R</code> instructions use absolute
|
||
|
|
or PC-relative addressing. If the processor includes the absolute
|
||
|
|
addressing option, the default is to use absolute <code>L32R</code>
|
||
|
|
relocations. Otherwise, only the PC-relative <code>L32R</code> relocations
|
||
|
|
can be used.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--target-align | --no-target-align</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dtarget_002dalign"></a>
|
||
|
|
<a name="index-_002d_002dno_002dtarget_002dalign"></a>
|
||
|
|
<p>Enable or disable automatic alignment to reduce branch penalties at some
|
||
|
|
expense in code size. See <a href="Xtensa-Automatic-Alignment.html#Xtensa-Automatic-Alignment">Automatic
|
||
|
|
Instruction Alignment</a>. This optimization is enabled by default. Note
|
||
|
|
that the assembler will always align instructions like <code>LOOP</code> that
|
||
|
|
have fixed alignment requirements.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--longcalls | --no-longcalls</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dlongcalls"></a>
|
||
|
|
<a name="index-_002d_002dno_002dlongcalls"></a>
|
||
|
|
<p>Enable or disable transformation of call instructions to allow calls
|
||
|
|
across a greater range of addresses. See <a href="Xtensa-Call-Relaxation.html#Xtensa-Call-Relaxation">Function Call Relaxation</a>. This option should be used when call
|
||
|
|
targets can potentially be out of range. It may degrade both code size
|
||
|
|
and performance, but the linker can generally optimize away the
|
||
|
|
unnecessary overhead when a call ends up within range. The default is
|
||
|
|
‘<samp>--no-longcalls</samp>’.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--transform | --no-transform</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dtransform"></a>
|
||
|
|
<a name="index-_002d_002dno_002dtransform"></a>
|
||
|
|
<p>Enable or disable all assembler transformations of Xtensa instructions,
|
||
|
|
including both relaxation and optimization. The default is
|
||
|
|
‘<samp>--transform</samp>’; ‘<samp>--no-transform</samp>’ should only be used in the
|
||
|
|
rare cases when the instructions must be exactly as specified in the
|
||
|
|
assembly source. Using ‘<samp>--no-transform</samp>’ causes out of range
|
||
|
|
instruction operands to be errors.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--rename-section <var>oldname</var>=<var>newname</var></code></dt>
|
||
|
|
<dd><a name="index-_002d_002drename_002dsection"></a>
|
||
|
|
<p>Rename the <var>oldname</var> section to <var>newname</var>. This option can be used
|
||
|
|
multiple times to rename multiple sections.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>--trampolines | --no-trampolines</code></dt>
|
||
|
|
<dd><a name="index-_002d_002dtrampolines"></a>
|
||
|
|
<a name="index-_002d_002dno_002dtrampolines"></a>
|
||
|
|
<p>Enable or disable transformation of jump instructions to allow jumps
|
||
|
|
across a greater range of addresses. See <a href="Xtensa-Jump-Relaxation.html#Xtensa-Jump-Relaxation">Jump Trampolines</a>. This option should be used when jump targets can
|
||
|
|
potentially be out of range. In the absence of such jumps this option
|
||
|
|
does not affect code size or performance. The default is
|
||
|
|
‘<samp>--trampolines</samp>’.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Xtensa-Syntax.html#Xtensa-Syntax" accesskey="n" rel="next">Xtensa Syntax</a>, Up: <a href="Xtensa_002dDependent.html#Xtensa_002dDependent" accesskey="u" rel="up">Xtensa-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>
|