toolchain/gcc-linaro-6.3.1-2017.02-x8.../share/doc/as.html/i386_002dLWP.html

93 lines
4.0 KiB
HTML
Raw Permalink Normal View History

2024-03-22 05:10:17 +00:00
<!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: i386-LWP</title>
<meta name="description" content="Using as: i386-LWP">
<meta name="keywords" content="Using as: i386-LWP">
<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="i386_002dDependent.html#i386_002dDependent" rel="up" title="i386-Dependent">
<link href="i386_002dBMI.html#i386_002dBMI" rel="next" title="i386-BMI">
<link href="i386_002dSIMD.html#i386_002dSIMD" rel="prev" title="i386-SIMD">
<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="i386_002dLWP"></a>
<div class="header">
<p>
Next: <a href="i386_002dBMI.html#i386_002dBMI" accesskey="n" rel="next">i386-BMI</a>, Previous: <a href="i386_002dSIMD.html#i386_002dSIMD" accesskey="p" rel="prev">i386-SIMD</a>, Up: <a href="i386_002dDependent.html#i386_002dDependent" accesskey="u" rel="up">i386-Dependent</a> &nbsp; [<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="AMD_0027s-Lightweight-Profiling-Instructions"></a>
<h4 class="subsection">9.15.11 AMD&rsquo;s Lightweight Profiling Instructions</h4>
<a name="index-LWP_002c-i386"></a>
<a name="index-LWP_002c-x86_002d64"></a>
<p><code>as</code> supports AMD&rsquo;s Lightweight Profiling (LWP)
instruction set, available on AMD&rsquo;s Family 15h (Orochi) processors.
</p>
<p>LWP enables applications to collect and manage performance data, and
react to performance events. The collection of performance data
requires no context switches. LWP runs in the context of a thread and
so several counters can be used independently across multiple threads.
LWP can be used in both 64-bit and legacy 32-bit modes.
</p>
<p>For detailed information on the LWP instruction set, see the
<cite>AMD Lightweight Profiling Specification</cite> available at
<a href="http://developer.amd.com/cpu/LWP">Lightweight Profiling Specification</a>.
</p>
</body>
</html>