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.
97 lines
4.1 KiB
HTML
97 lines
4.1 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1992-2019 Free Software Foundation, Inc.
|
||
|
|
Contributed by Cygnus Support. Written by Julia Menapace, Jim Kingdon,
|
||
|
|
and David MacKenzie.
|
||
|
|
|
||
|
|
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>Register Variables (STABS)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Register Variables (STABS)">
|
||
|
|
<meta name="keywords" content="Register Variables (STABS)">
|
||
|
|
<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="Symbol-Types-Index.html#Symbol-Types-Index" rel="index" title="Symbol Types Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="Variables.html#Variables" rel="up" title="Variables">
|
||
|
|
<link href="Common-Blocks.html#Common-Blocks" rel="next" title="Common Blocks">
|
||
|
|
<link href="Global-Variables.html#Global-Variables" rel="prev" title="Global Variables">
|
||
|
|
<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="Register-Variables"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Common-Blocks.html#Common-Blocks" accesskey="n" rel="next">Common Blocks</a>, Previous: <a href="Global-Variables.html#Global-Variables" accesskey="p" rel="prev">Global Variables</a>, Up: <a href="Variables.html#Variables" accesskey="u" rel="up">Variables</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Register-Variables-1"></a>
|
||
|
|
<h3 class="section">4.3 Register Variables</h3>
|
||
|
|
|
||
|
|
<a name="index-N_005fRSYM"></a>
|
||
|
|
<a name="index-C_005fRSYM"></a>
|
||
|
|
<p>Register variables have their own stab type, <code>N_RSYM</code>
|
||
|
|
(<code>C_RSYM</code> for XCOFF), and their own symbol descriptor, ‘<samp>r</samp>’.
|
||
|
|
The stab’s value is the number of the register where the variable data
|
||
|
|
will be stored.
|
||
|
|
</p>
|
||
|
|
<p>AIX defines a separate symbol descriptor ‘<samp>d</samp>’ for floating point
|
||
|
|
registers. This seems unnecessary; why not just just give floating
|
||
|
|
point registers different register numbers? I have not verified whether
|
||
|
|
the compiler actually uses ‘<samp>d</samp>’.
|
||
|
|
</p>
|
||
|
|
<p>If the register is explicitly allocated to a global variable, but not
|
||
|
|
initialized, as in:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example">register int g_bar asm ("%g5");
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>then the stab may be emitted at the end of the object file, with
|
||
|
|
the other bss symbols.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|