81 lines
4.1 KiB
HTML
81 lines
4.1 KiB
HTML
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<html lang="en">
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<title>s390 Literal Pool Entries - Using as</title>
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<meta name="description" content="Using as">
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<link title="Top" rel="start" href="index.html#Top">
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<link rel="up" href="s390-Syntax.html#s390-Syntax" title="s390 Syntax">
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<!--
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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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</head>
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<div class="node">
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<a name="s390-Literal-Pool-Entries"></a>
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<p>
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Previous: <a rel="previous" accesskey="p" href="s390-Instruction-Marker.html#s390-Instruction-Marker">s390 Instruction Marker</a>,
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Up: <a rel="up" accesskey="u" href="s390-Syntax.html#s390-Syntax">s390 Syntax</a>
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<hr>
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</div>
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<h5 class="subsubsection">9.41.3.8 Literal Pool Entries</h5>
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<p><a name="index-literal-pool-entries_002c-s390-2082"></a><a name="index-s390-literal-pool-entries-2083"></a>
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A literal pool is a collection of values. To access the values a pointer
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to the literal pool is loaded to a register, the literal pool register.
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Usually, register %r13 is used as the literal pool register
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(<a href="s390-Register.html#s390-Register">s390 Register</a>). Literal pool entries are created by adding the
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suffix :lit1, :lit2, :lit4, or :lit8 to the end of an expression for an
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instruction operand. The expression is added to the literal pool and the
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operand is replaced with the offset to the literal in the literal pool.
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<dl>
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<dt><code>:lit1</code><dd>The literal pool entry is created as an 8-bit value. An operand modifier
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must not be used for the original expression.
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<br><dt><code>:lit2</code><dd>The literal pool entry is created as a 16 bit value. The operand modifier
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@got may be used in the original expression. The term ‘<samp><span class="samp">x@got:lit2</span></samp>’
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will put the got offset for the global symbol x to the literal pool as
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16 bit value.
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<br><dt><code>:lit4</code><dd>The literal pool entry is created as a 32-bit value. The operand modifier
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@got and @plt may be used in the original expression. The term
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‘<samp><span class="samp">x@got:lit4</span></samp>’ will put the got offset for the global symbol x to the
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literal pool as a 32-bit value. The term ‘<samp><span class="samp">x@plt:lit4</span></samp>’ will put the
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plt offset for the global symbol x to the literal pool as a 32-bit value.
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<br><dt><code>:lit8</code><dd>The literal pool entry is created as a 64-bit value. The operand modifier
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@got and @plt may be used in the original expression. The term
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‘<samp><span class="samp">x@got:lit8</span></samp>’ will put the got offset for the global symbol x to the
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literal pool as a 64-bit value. The term ‘<samp><span class="samp">x@plt:lit8</span></samp>’ will put the
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plt offset for the global symbol x to the literal pool as a 64-bit value.
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</dl>
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<p>The assembler directive ‘<samp><span class="samp">.ltorg</span></samp>’ is used to emit all literal pool
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entries to the current position.
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</body></html>
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