<html lang="en">
<head>
<title>Insn Attributes - GNU Compiler Collection (GCC) Internals</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Compiler Collection (GCC) Internals">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Machine-Desc.html#Machine-Desc" title="Machine Desc">
<link rel="prev" href="Peephole-Definitions.html#Peephole-Definitions" title="Peephole Definitions">
<link rel="next" href="Conditional-Execution.html#Conditional-Execution" title="Conditional Execution">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1988-2015 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 the
Invariant Sections being ``Funding Free Software'', the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
``GNU Free Documentation License''.
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development.-->
<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="Insn-Attributes"></a>
<p>
Next: <a rel="next" accesskey="n" href="Conditional-Execution.html#Conditional-Execution">Conditional Execution</a>,
Previous: <a rel="previous" accesskey="p" href="Peephole-Definitions.html#Peephole-Definitions">Peephole Definitions</a>,
Up: <a rel="up" accesskey="u" href="Machine-Desc.html#Machine-Desc">Machine Desc</a>
<hr>
</div>
<h3 class="section">16.19 Instruction Attributes</h3>
<p><a name="index-insn-attributes-3719"></a><a name="index-instruction-attributes-3720"></a>
In addition to describing the instruction supported by the target machine,
the <samp><span class="file">md</span></samp> file also defines a group of <dfn>attributes</dfn> and a set of
values for each. Every generated insn is assigned a value for each attribute.
One possible attribute would be the effect that the insn has on the machine's
condition code. This attribute can then be used by <code>NOTICE_UPDATE_CC</code>
to track the condition codes.
<ul class="menu">
<li><a accesskey="1" href="Defining-Attributes.html#Defining-Attributes">Defining Attributes</a>: Specifying attributes and their values.
<li><a accesskey="2" href="Expressions.html#Expressions">Expressions</a>: Valid expressions for attribute values.
<li><a accesskey="3" href="Tagging-Insns.html#Tagging-Insns">Tagging Insns</a>: Assigning attribute values to insns.
<li><a accesskey="4" href="Attr-Example.html#Attr-Example">Attr Example</a>: An example of assigning attributes.
<li><a accesskey="5" href="Insn-Lengths.html#Insn-Lengths">Insn Lengths</a>: Computing the length of insns.
<li><a accesskey="6" href="Constant-Attributes.html#Constant-Attributes">Constant Attributes</a>: Defining attributes that are constant.
<li><a accesskey="7" href="Mnemonic-Attribute.html#Mnemonic-Attribute">Mnemonic Attribute</a>: Obtain the instruction mnemonic as attribute value.
<li><a accesskey="8" href="Delay-Slots.html#Delay-Slots">Delay Slots</a>: Defining delay slots required for a machine.
<li><a accesskey="9" href="Processor-pipeline-description.html#Processor-pipeline-description">Processor pipeline description</a>: Specifying information for insn scheduling.
</ul>
</body></html>