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.
118 lines
7.7 KiB
HTML
118 lines
7.7 KiB
HTML
4 years ago
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>Xtensa Options - Using as</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Using as">
|
||
|
|
<meta name="generator" content="makeinfo 4.13">
|
||
|
|
<link title="Top" rel="start" href="index.html#Top">
|
||
|
|
<link rel="up" href="Xtensa_002dDependent.html#Xtensa_002dDependent" title="Xtensa-Dependent">
|
||
|
|
<link rel="next" href="Xtensa-Syntax.html#Xtensa-Syntax" title="Xtensa Syntax">
|
||
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
||
|
|
<!--
|
||
|
|
This file documents the GNU Assembler "as".
|
||
|
|
|
||
|
|
Copyright (C) 1991-2015 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''.
|
||
|
|
|
||
|
|
-->
|
||
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
||
|
|
<style type="text/css"><!--
|
||
|
|
pre.display { font-family:inherit }
|
||
|
|
pre.format { font-family:inherit }
|
||
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallexample { font-size:smaller }
|
||
|
|
pre.smalllisp { font-size:smaller }
|
||
|
|
span.sc { font-variant:small-caps }
|
||
|
|
span.roman { font-family:serif; font-weight:normal; }
|
||
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="node">
|
||
|
|
<a name="Xtensa-Options"></a>
|
||
|
|
<p>
|
||
|
|
Next: <a rel="next" accesskey="n" href="Xtensa-Syntax.html#Xtensa-Syntax">Xtensa Syntax</a>,
|
||
|
|
Up: <a rel="up" accesskey="u" href="Xtensa_002dDependent.html#Xtensa_002dDependent">Xtensa-Dependent</a>
|
||
|
|
<hr>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<h4 class="subsection">9.52.1 Command Line Options</h4>
|
||
|
|
|
||
|
|
<!-- man begin OPTIONS -->
|
||
|
|
<dl>
|
||
|
|
<dt><code>--text-section-literals | --no-text-section-literals</code><dd><a name="index-g_t_002d_002dtext_002dsection_002dliterals-2435"></a><a name="index-g_t_002d_002dno_002dtext_002dsection_002dliterals-2436"></a>Control the treatment of literal pools. The default is
|
||
|
|
‘<samp><span class="samp">--no-text-section-literals</span></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><span class="samp">--text-section-literals</span></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>.
|
||
|
|
|
||
|
|
<br><dt><code>--auto-litpools | --no-auto-litpools</code><dd><a name="index-g_t_002d_002dauto_002dlitpools-2437"></a><a name="index-g_t_002d_002dno_002dauto_002dlitpools-2438"></a>Control the treatment of literal pools. The default is
|
||
|
|
‘<samp><span class="samp">--no-auto-litpools</span></samp>’, which in the absence of
|
||
|
|
‘<samp><span class="samp">--text-section-literals</span></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><span class="samp">--auto-litpools</span></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><span class="samp">--text-section-literals</span></samp>’,
|
||
|
|
‘<samp><span class="samp">--auto-litpools</span></samp>’ takes precedence.
|
||
|
|
See <a href="Literal-Directive.html#Literal-Directive">literal</a>.
|
||
|
|
|
||
|
|
<br><dt><code>--absolute-literals | --no-absolute-literals</code><dd><a name="index-g_t_002d_002dabsolute_002dliterals-2439"></a><a name="index-g_t_002d_002dno_002dabsolute_002dliterals-2440"></a>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.
|
||
|
|
|
||
|
|
<br><dt><code>--target-align | --no-target-align</code><dd><a name="index-g_t_002d_002dtarget_002dalign-2441"></a><a name="index-g_t_002d_002dno_002dtarget_002dalign-2442"></a>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.
|
||
|
|
|
||
|
|
<br><dt><code>--longcalls | --no-longcalls</code><dd><a name="index-g_t_002d_002dlongcalls-2443"></a><a name="index-g_t_002d_002dno_002dlongcalls-2444"></a>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><span class="samp">--no-longcalls</span></samp>’.
|
||
|
|
|
||
|
|
<br><dt><code>--transform | --no-transform</code><dd><a name="index-g_t_002d_002dtransform-2445"></a><a name="index-g_t_002d_002dno_002dtransform-2446"></a>Enable or disable all assembler transformations of Xtensa instructions,
|
||
|
|
including both relaxation and optimization. The default is
|
||
|
|
‘<samp><span class="samp">--transform</span></samp>’; ‘<samp><span class="samp">--no-transform</span></samp>’ should only be used in the
|
||
|
|
rare cases when the instructions must be exactly as specified in the
|
||
|
|
assembly source. Using ‘<samp><span class="samp">--no-transform</span></samp>’ causes out of range
|
||
|
|
instruction operands to be errors.
|
||
|
|
|
||
|
|
<br><dt><code>--rename-section </code><var>oldname</var><code>=</code><var>newname</var><dd><a name="index-g_t_002d_002drename_002dsection-2447"></a>Rename the <var>oldname</var> section to <var>newname</var>. This option can be used
|
||
|
|
multiple times to rename multiple sections.
|
||
|
|
|
||
|
|
<br><dt><code>--trampolines | --no-trampolines</code><dd><a name="index-g_t_002d_002dtrampolines-2448"></a><a name="index-g_t_002d_002dno_002dtrampolines-2449"></a>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><span class="samp">--trampolines</span></samp>’.
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<!-- man end -->
|
||
|
|
</body></html>
|
||
|
|
|