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.
126 lines
7.9 KiB
HTML
126 lines
7.9 KiB
HTML
15 years ago
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>PowerPC64 ELF64 - Untitled</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Untitled">
|
||
|
|
<meta name="generator" content="makeinfo 4.7">
|
||
|
|
<link title="Top" rel="start" href="index.html#Top">
|
||
|
|
<link rel="up" href="Machine-Dependent.html#Machine-Dependent" title="Machine Dependent">
|
||
|
|
<link rel="prev" href="PowerPC-ELF32.html#PowerPC-ELF32" title="PowerPC ELF32">
|
||
|
|
<link rel="next" href="SPU-ELF.html#SPU-ELF" title="SPU ELF">
|
||
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
||
|
|
<!--
|
||
|
|
This file documents the GNU linker LD
|
||
|
|
(GNU Binutils)
|
||
|
|
version 2.19.
|
||
|
|
|
||
|
|
Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
|
||
|
|
2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.1
|
||
|
|
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; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="node">
|
||
|
|
<p>
|
||
|
|
<a name="PowerPC64-ELF64"></a>Next: <a rel="next" accesskey="n" href="SPU-ELF.html#SPU-ELF">SPU ELF</a>,
|
||
|
|
Previous: <a rel="previous" accesskey="p" href="PowerPC-ELF32.html#PowerPC-ELF32">PowerPC ELF32</a>,
|
||
|
|
Up: <a rel="up" accesskey="u" href="Machine-Dependent.html#Machine-Dependent">Machine Dependent</a>
|
||
|
|
<hr><br>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<h3 class="section">4.10 <span class="command">ld</span> and PowerPC64 64-bit ELF Support</h3>
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-ELF64-options-579"></a>
|
||
|
|
|
||
|
|
<a name="index-PowerPC64-stub-grouping-580"></a>
|
||
|
|
<a name="index-_002d_002dstub_002dgroup_002dsize-581"></a>
|
||
|
|
<dl><dt><span class="option">--stub-group-size</span><dd>Long branch stubs, PLT call stubs and TOC adjusting stubs are placed
|
||
|
|
by <span class="command">ld</span> in stub sections located between groups of input sections.
|
||
|
|
<span class="samp">--stub-group-size</span> specifies the maximum size of a group of input
|
||
|
|
sections handled by one stub section. Since branch offsets are signed,
|
||
|
|
a stub section may serve two groups of input sections, one group before
|
||
|
|
the stub section, and one group after it. However, when using
|
||
|
|
conditional branches that require stubs, it may be better (for branch
|
||
|
|
prediction) that stub sections only serve one group of input sections.
|
||
|
|
A negative value for <span class="samp">N</span> chooses this scheme, ensuring that
|
||
|
|
branches to stubs always use a negative offset. Two special values of
|
||
|
|
<span class="samp">N</span> are recognized, <span class="samp">1</span> and <span class="samp">-1</span>. These both instruct
|
||
|
|
<span class="command">ld</span> to automatically size input section groups for the branch types
|
||
|
|
detected, with the same behaviour regarding stub placement as other
|
||
|
|
positive or negative values of <span class="samp">N</span> respectively.
|
||
|
|
|
||
|
|
<p>Note that <span class="samp">--stub-group-size</span> does not split input sections. A
|
||
|
|
single input section larger than the group size specified will of course
|
||
|
|
create a larger group (of one section). If input sections are too
|
||
|
|
large, it may not be possible for a branch to reach its stub.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-stub-symbols-582"></a><a name="index-_002d_002demit_002dstub_002dsyms-583"></a><br><dt><span class="option">--emit-stub-syms</span><dd>This option causes <span class="command">ld</span> to label linker stubs with a local
|
||
|
|
symbol that encodes the stub type and destination.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-dot-symbols-584"></a><a name="index-_002d_002ddotsyms-585"></a><a name="index-_002d_002dno_002ddotsyms-586"></a><br><dt><span class="option">--dotsyms, --no-dotsyms</span><dd>These two options control how <span class="command">ld</span> interprets version patterns
|
||
|
|
in a version script. Older PowerPC64 compilers emitted both a
|
||
|
|
function descriptor symbol with the same name as the function, and a
|
||
|
|
code entry symbol with the name prefixed by a dot (<span class="samp">.</span>). To
|
||
|
|
properly version a function <span class="samp">foo</span>, the version script thus needs
|
||
|
|
to control both <span class="samp">foo</span> and <span class="samp">.foo</span>. The option
|
||
|
|
<span class="samp">--dotsyms</span>, on by default, automatically adds the required
|
||
|
|
dot-prefixed patterns. Use <span class="samp">--no-dotsyms</span> to disable this
|
||
|
|
feature.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-TLS-optimization-587"></a><a name="index-_002d_002dno_002dtls_002doptimize-588"></a><br><dt><span class="option">--no-tls-optimize</span><dd>PowerPC64 <span class="command">ld</span> normally performs some optimization of code
|
||
|
|
sequences used to access Thread-Local Storage. Use this option to
|
||
|
|
disable the optimization.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-OPD-optimization-589"></a><a name="index-_002d_002dno_002dopd_002doptimize-590"></a><br><dt><span class="option">--no-opd-optimize</span><dd>PowerPC64 <span class="command">ld</span> normally removes <code>.opd</code> section entries
|
||
|
|
corresponding to deleted link-once functions, or functions removed by
|
||
|
|
the action of <span class="samp">--gc-sections</span> or linker script <code>/DISCARD/</code>.
|
||
|
|
Use this option to disable <code>.opd</code> optimization.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-OPD-spacing-591"></a><a name="index-_002d_002dnon_002doverlapping_002dopd-592"></a><br><dt><span class="option">--non-overlapping-opd</span><dd>Some PowerPC64 compilers have an option to generate compressed
|
||
|
|
<code>.opd</code> entries spaced 16 bytes apart, overlapping the third word,
|
||
|
|
the static chain pointer (unused in C) with the first word of the next
|
||
|
|
entry. This option expands such entries to the full 24 bytes.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-TOC-optimization-593"></a><a name="index-_002d_002dno_002dtoc_002doptimize-594"></a><br><dt><span class="option">--no-toc-optimize</span><dd>PowerPC64 <span class="command">ld</span> normally removes unused <code>.toc</code> section
|
||
|
|
entries. Such entries are detected by examining relocations that
|
||
|
|
reference the TOC in code sections. A reloc in a deleted code section
|
||
|
|
marks a TOC word as unneeded, while a reloc in a kept code section
|
||
|
|
marks a TOC word as needed. Since the TOC may reference itself, TOC
|
||
|
|
relocs are also examined. TOC words marked as both needed and
|
||
|
|
unneeded will of course be kept. TOC words without any referencing
|
||
|
|
reloc are assumed to be part of a multi-word entry, and are kept or
|
||
|
|
discarded as per the nearest marked preceding word. This works
|
||
|
|
reliably for compiler generated code, but may be incorrect if assembly
|
||
|
|
code is used to insert TOC entries. Use this option to disable the
|
||
|
|
optimization.
|
||
|
|
|
||
|
|
<p><a name="index-PowerPC64-multi_002dTOC-595"></a><a name="index-_002d_002dno_002dmulti_002dtoc-596"></a><br><dt><span class="option">--no-multi-toc</span><dd>By default, PowerPC64 GCC generates code for a TOC model where TOC
|
||
|
|
entries are accessed with a 16-bit offset from r2. This limits the
|
||
|
|
total TOC size to 64K. PowerPC64 <span class="command">ld</span> extends this limit by
|
||
|
|
grouping code sections such that each group uses less than 64K for its
|
||
|
|
TOC entries, then inserts r2 adjusting stubs between inter-group
|
||
|
|
calls. <span class="command">ld</span> does not split apart input sections, so cannot
|
||
|
|
help if a single input file has a <code>.toc</code> section that exceeds
|
||
|
|
64K, most likely from linking multiple files with <span class="command">ld -r</span>.
|
||
|
|
Use this option to turn off this feature.
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
</body></html>
|
||
|
|
|