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105 lines
4.6 KiB
HTML
105 lines
4.6 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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<!-- This file documents the GNU Assembler "as".
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Copyright (C) 1991-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>Absolute Literals Directive (Using as)</title>
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<meta name="description" content="Absolute Literals Directive (Using as)">
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<meta name="keywords" content="Absolute Literals Directive (Using as)">
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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="Xtensa-Directives.html#Xtensa-Directives" rel="up" title="Xtensa Directives">
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<link href="Z80_002dDependent.html#Z80_002dDependent" rel="next" title="Z80-Dependent">
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<link href="Literal-Prefix-Directive.html#Literal-Prefix-Directive" rel="prev" title="Literal Prefix Directive">
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<style type="text/css">
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a.summary-letter {text-decoration: none}
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div.example {margin-left: 3.2em}
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span.nolinebreak {white-space: nowrap}
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span.roman {font-family: initial; font-weight: normal}
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span.sansserif {font-family: sans-serif; font-weight: normal}
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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="Absolute-Literals-Directive"></a>
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<div class="header">
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<p>
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Previous: <a href="Literal-Prefix-Directive.html#Literal-Prefix-Directive" accesskey="p" rel="prev">Literal Prefix Directive</a>, Up: <a href="Xtensa-Directives.html#Xtensa-Directives" accesskey="u" rel="up">Xtensa Directives</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="absolute_002dliterals"></a>
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<h4 class="subsubsection">9.54.5.7 absolute-literals</h4>
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<a name="index-absolute_002dliterals-directive"></a>
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<a name="index-no_002dabsolute_002dliterals-directive"></a>
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<p>The <code>absolute-literals</code> and <code>no-absolute-literals</code>
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directives control the absolute vs. PC-relative mode for <code>L32R</code>
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instructions. These are relevant only for Xtensa configurations that
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include the absolute addressing option for <code>L32R</code> instructions.
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</p>
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<div class="smallexample">
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<pre class="smallexample"> .begin [no-]absolute-literals
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.end [no-]absolute-literals
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</pre></div>
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<p>These directives do not change the <code>L32R</code> mode—they only cause
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the assembler to emit the appropriate kind of relocation for <code>L32R</code>
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instructions and to place the literal values in the appropriate section.
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To change the <code>L32R</code> mode, the program must write the
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<code>LITBASE</code> special register. It is the programmer’s responsibility
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to keep track of the mode and indicate to the assembler which mode is
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used in each region of code.
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</p>
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<p>If the Xtensa configuration includes the absolute <code>L32R</code> addressing
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option, the default is to assume absolute <code>L32R</code> addressing unless
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the ‘<samp>--no-absolute-literals</samp>’ command-line option is specified.
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Otherwise, the default is to assume PC-relative <code>L32R</code> addressing.
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The <code>absolute-literals</code> directive can then be used to override
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the default determined by the command-line options.
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</p>
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</body>
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</html>
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