97 lines
4.1 KiB
HTML
97 lines
4.1 KiB
HTML
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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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<!-- This file documents the GNU Assembler "as".
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Copyright (C) 1991-2016 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
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or any later version published by the Free Software Foundation;
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with no Invariant Sections, with no Front-Cover Texts, and with no
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Back-Cover Texts. A copy of the license is included in the
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section entitled "GNU Free Documentation License".
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-->
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<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>Using as: Expressions</title>
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<meta name="description" content="Using as: Expressions">
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<meta name="keywords" content="Using as: Expressions">
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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="AS-Index.html#AS-Index" rel="index" title="AS Index">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="index.html#Top" rel="up" title="Top">
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<link href="Empty-Exprs.html#Empty-Exprs" rel="next" title="Empty Exprs">
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<link href="SOM-Symbols.html#SOM-Symbols" rel="prev" title="SOM Symbols">
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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" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
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<a name="Expressions"></a>
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<div class="header">
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<p>
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Next: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="n" rel="next">Pseudo Ops</a>, Previous: <a href="Symbols.html#Symbols" accesskey="p" rel="prev">Symbols</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> [<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>
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</div>
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<hr>
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<a name="Expressions-1"></a>
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<h2 class="chapter">6 Expressions</h2>
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<a name="index-expressions"></a>
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<a name="index-addresses"></a>
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<a name="index-numeric-values"></a>
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<p>An <em>expression</em> specifies an address or numeric value.
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Whitespace may precede and/or follow an expression.
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</p>
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<p>The result of an expression must be an absolute number, or else an offset into
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a particular section. If an expression is not absolute, and there is not
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enough information when <code>as</code> sees the expression to know its
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section, a second pass over the source program might be necessary to interpret
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the expression—but the second pass is currently not implemented.
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<code>as</code> aborts with an error message in this situation.
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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="Empty-Exprs.html#Empty-Exprs" accesskey="1">Empty Exprs</a>:</td><td> </td><td align="left" valign="top">Empty Expressions
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Integer-Exprs.html#Integer-Exprs" accesskey="2">Integer Exprs</a>:</td><td> </td><td align="left" valign="top">Integer Expressions
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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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