visus
/
toolchain-gcc-arm-embedded


			
							<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 1988-2020 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. -->
<!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Operands (GNU Compiler Collection (GCC) Internals)</title>

<meta name="description" content="Operands (GNU Compiler Collection (GCC) Internals)">
<meta name="keywords" content="Operands (GNU Compiler Collection (GCC) Internals)">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<link href="index.html#Top" rel="start" title="Top">
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="GIMPLE.html#GIMPLE" rel="up" title="GIMPLE">
<link href="Compound-Expressions.html#Compound-Expressions" rel="next" title="Compound Expressions">
<link href="Temporaries.html#Temporaries" rel="prev" title="Temporaries">
<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="Operands"></a>
<div class="header">
<p>
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> &nbsp; [<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>
</div>
<hr>
<a name="Operands-1"></a>
<h3 class="section">12.6 Operands</h3>
<a name="index-Operands"></a>

<p>In general, expressions in GIMPLE consist of an operation and the
appropriate number of simple operands; these operands must either be a
GIMPLE rvalue (<code>is_gimple_val</code>), i.e. a constant or a register
variable.  More complex operands are factored out into temporaries, so
that
</p><div class="smallexample">
<pre class="smallexample">a = b + c + d
</pre></div>
<p>becomes
</p><div class="smallexample">
<pre class="smallexample">T1 = b + c;
a = T1 + d;
</pre></div>

<p>The same rule holds for arguments to a <code>GIMPLE_CALL</code>.
</p>
<p>The target of an assignment is usually a variable, but can also be a
<code>MEM_REF</code> or a compound lvalue as described below.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="Compound-Expressions.html#Compound-Expressions" accesskey="1">Compound Expressions</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Compound-Lvalues.html#Compound-Lvalues" accesskey="2">Compound Lvalues</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Conditional-Expressions.html#Conditional-Expressions" accesskey="3">Conditional Expressions</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Logical-Operators.html#Logical-Operators" accesskey="4">Logical Operators</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
</table>


</body>
</html>