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<title>Using as: Sparc-Size-Translations</title>
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<a name="Sparc_002dSize_002dTranslations"></a>
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Previous: <a href="Sparc_002dRelocs.html#Sparc_002dRelocs" accesskey="p" rel="previous">Sparc-Relocs</a>, Up: <a href="Sparc_002dSyntax.html#Sparc_002dSyntax" accesskey="u" rel="up">Sparc-Syntax</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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<hr>
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<a name="Size-Translations"></a>
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<h4 class="subsubsection">9.44.3.5 Size Translations</h4>
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<a name="index-Sparc-size-translations"></a>
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<a name="index-size_002c-translations_002c-Sparc"></a>
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<p>Often it is desirable to write code in an operand size agnostic
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manner. <code>as</code> provides support for this via
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operand size opcode translations. Translations are supported
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for loads, stores, shifts, compare-and-swap atomics, and the
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‘<samp>clr</samp>’ synthetic instruction.
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</p>
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<p>If generating 32-bit code, <code>as</code> will generate the
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32-bit opcode. Whereas if 64-bit code is being generated,
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the 64-bit opcode will be emitted. For example <code>ldn</code>
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will be transformed into <code>ld</code> for 32-bit code and
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<code>ldx</code> for 64-bit code.
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</p>
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<p>Here is an example meant to demonstrate all the supported
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opcode translations:
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</p>
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<div class="example">
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<pre class="example">ldn [%o0], %o1
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ldna [%o0] %asi, %o2
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stn %o1, [%o0]
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stna %o2, [%o0] %asi
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slln %o3, 3, %o3
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srln %o4, 8, %o4
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sran %o5, 12, %o5
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casn [%o0], %o1, %o2
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casna [%o0] %asi, %o1, %o2
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clrn %g1
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</pre></div>
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<p>In 32-bit mode <code>as</code> will emit:
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</p>
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<div class="example">
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<pre class="example">ld [%o0], %o1
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lda [%o0] %asi, %o2
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st %o1, [%o0]
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sta %o2, [%o0] %asi
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sll %o3, 3, %o3
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srl %o4, 8, %o4
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sra %o5, 12, %o5
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cas [%o0], %o1, %o2
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casa [%o0] %asi, %o1, %o2
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clr %g1
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</pre></div>
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<p>And in 64-bit mode <code>as</code> will emit:
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</p>
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<div class="example">
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<pre class="example">ldx [%o0], %o1
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ldxa [%o0] %asi, %o2
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stx %o1, [%o0]
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stxa %o2, [%o0] %asi
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sllx %o3, 3, %o3
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srlx %o4, 8, %o4
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srax %o5, 12, %o5
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casx [%o0], %o1, %o2
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casxa [%o0] %asi, %o1, %o2
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clrx %g1
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</pre></div>
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<p>Finally, the ‘<samp>.nword</samp>’ translating directive is supported
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as well. It is documented in the section on Sparc machine
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directives.
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</p>
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