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115 lines
5.0 KiB
HTML
115 lines
5.0 KiB
HTML
4 years ago
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- Copyright (C) 1988-2018 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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any later version published by the Free Software Foundation; with the
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Invariant Sections being "Funding Free Software", the Front-Cover
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Texts being (a) (see below), and with the Back-Cover Texts being (b)
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(see below). A copy of the license is included in the section entitled
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"GNU Free Documentation License".
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(a) The FSF's Front-Cover Text is:
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A GNU Manual
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(b) The FSF's Back-Cover Text is:
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You have freedom to copy and modify this GNU Manual, like GNU
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software. Copies published by the Free Software Foundation raise
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funds for GNU development. -->
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<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>Operands (GNU Compiler Collection (GCC) Internals)</title>
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<meta name="description" content="Operands (GNU Compiler Collection (GCC) Internals)">
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<meta name="keywords" content="Operands (GNU Compiler Collection (GCC) Internals)">
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<meta name="resource-type" content="document">
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<meta name="distribution" content="global">
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<meta name="Generator" content="makeinfo">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<link href="index.html#Top" rel="start" title="Top">
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<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="GIMPLE.html#GIMPLE" rel="up" title="GIMPLE">
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<link href="Compound-Expressions.html#Compound-Expressions" rel="next" title="Compound Expressions">
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<link href="Temporaries.html#Temporaries" rel="prev" title="Temporaries">
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<style type="text/css">
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ul.no-bullet {list-style: none}
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-->
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</style>
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</head>
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<body lang="en">
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<a name="Operands"></a>
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<div class="header">
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<p>
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Next: <a href="Manipulating-GIMPLE-statements.html#Manipulating-GIMPLE-statements" accesskey="n" rel="next">Manipulating GIMPLE statements</a>, Previous: <a href="Temporaries.html#Temporaries" accesskey="p" rel="prev">Temporaries</a>, Up: <a href="GIMPLE.html#GIMPLE" accesskey="u" rel="up">GIMPLE</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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</div>
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<hr>
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<a name="Operands-1"></a>
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<h3 class="section">12.6 Operands</h3>
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<a name="index-Operands"></a>
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<p>In general, expressions in GIMPLE consist of an operation and the
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appropriate number of simple operands; these operands must either be a
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GIMPLE rvalue (<code>is_gimple_val</code>), i.e. a constant or a register
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variable. More complex operands are factored out into temporaries, so
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that
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</p><div class="smallexample">
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<pre class="smallexample">a = b + c + d
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</pre></div>
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<p>becomes
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</p><div class="smallexample">
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<pre class="smallexample">T1 = b + c;
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a = T1 + d;
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</pre></div>
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<p>The same rule holds for arguments to a <code>GIMPLE_CALL</code>.
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</p>
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<p>The target of an assignment is usually a variable, but can also be a
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<code>MEM_REF</code> or a compound lvalue as described below.
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</p>
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<table class="menu" border="0" cellspacing="0">
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<tr><td align="left" valign="top">• <a href="Compound-Expressions.html#Compound-Expressions" accesskey="1">Compound Expressions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Compound-Lvalues.html#Compound-Lvalues" accesskey="2">Compound Lvalues</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Conditional-Expressions.html#Conditional-Expressions" accesskey="3">Conditional Expressions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Logical-Operators.html#Logical-Operators" accesskey="4">Logical Operators</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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</table>
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</body>
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</html>
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