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<title>Using as: i386-SIMD</title>

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<a name="i386_002dSIMD"></a>
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Next: <a href="i386_002dLWP.html#i386_002dLWP" accesskey="n" rel="next">i386-LWP</a>, Previous: <a href="i386_002dFloat.html#i386_002dFloat" accesskey="p" rel="prev">i386-Float</a>, Up: <a href="i386_002dDependent.html#i386_002dDependent" accesskey="u" rel="up">i386-Dependent</a> &nbsp; [<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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<a name="Intel_0027s-MMX-and-AMD_0027s-3DNow_0021-SIMD-Operations"></a>
<h4 class="subsection">9.15.10 Intel&rsquo;s MMX and AMD&rsquo;s 3DNow! SIMD Operations</h4>

<a name="index-MMX_002c-i386"></a>
<a name="index-3DNow_0021_002c-i386"></a>
<a name="index-SIMD_002c-i386"></a>
<a name="index-MMX_002c-x86_002d64"></a>
<a name="index-3DNow_0021_002c-x86_002d64"></a>
<a name="index-SIMD_002c-x86_002d64"></a>

<p><code>as</code> supports Intel&rsquo;s MMX instruction set (SIMD
instructions for integer data), available on Intel&rsquo;s Pentium MMX
processors and Pentium II processors, AMD&rsquo;s K6 and K6-2 processors,
Cyrix&rsquo; M2 processor, and probably others.  It also supports AMD&rsquo;s 3DNow!
instruction set (SIMD instructions for 32-bit floating point data)
available on AMD&rsquo;s K6-2 processor and possibly others in the future.
</p>
<p>Currently, <code>as</code> does not support Intel&rsquo;s floating point
SIMD, Katmai (KNI).
</p>
<p>The eight 64-bit MMX operands, also used by 3DNow!, are called &lsquo;<samp>%mm0</samp>&rsquo;,
&lsquo;<samp>%mm1</samp>&rsquo;, ... &lsquo;<samp>%mm7</samp>&rsquo;.  They contain eight 8-bit integers, four
16-bit integers, two 32-bit integers, one 64-bit integer, or two 32-bit
floating point values.  The MMX registers cannot be used at the same time
as the floating point stack.
</p>
<p>See Intel and AMD documentation, keeping in mind that the operand order in
instructions is reversed from the Intel syntax.
</p>


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