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<title>MAXPS: Return Maximum Packed Single-Precision Floating-Point Values (x86 Instruction Set Reference)</title>
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<div class="main_container"><h1>x86 Instruction Set Reference</h1>
<title>MAXPS: Return Maximum Packed Single-Precision Floating-Point Values (x86 Instruction Set Reference)</title>
<h1>MAXPS</h1>
<h2>Return Maximum Packed Single-Precision Floating-Point Values</h2>
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<th>Opcode</th>
<th>Mnemonic</th>
<th>Description</th>
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<td class="grid"><code>0F 5F /r</code></td>
<td class="grid"><code>MAXPS xmm1, xmm2/m128</code></td>
<td class="grid">Return the maximum single-precision floating-point</td>
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<th>Description</th>
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<td class="instruction_set_reference_box">
<p>Performs an SIMD compare of the packed single-precision floating-point values in the destination operand (first operand) and the source operand (second operand), and returns the maximum value for each pair of values to the destination operand. The source operand can be an XMM register or a 128-bit memory location. The destination operand is an XMM register.</p>
<p>If the values being compared are both 0.0s (of either sign), the value in the second operand (source operand) is returned. If a value in the second operand is an SNaN, that SNaN is returned unchanged to the destination (that is, a QNaN version of the SNaN is not returned).</p>
<p>If only one value is a NaN (SNaN or QNaN) for this instruction, the second operand (source operand), either a NaN or a valid floating-point value, is written to the result. If instead of this behavior, it is required that the NaN source operand (from either the first or second operand) be returned, the action of MAXPS can be emulated using a sequence of instructions, such as, a comparison followed by AND, ANDN and OR.</p>
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<th>Operation</th>
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<td class="instruction_set_reference_box">
<pre><span class="keyword">if</span><span class="operator">(</span><span class="operator">(</span>Destination<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span> <span class="operator">&amp;&amp;</span> Source<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Destination<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Source<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> Destination<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span> <span class="operator">&lt;=</span> Source<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span><span class="operator">)</span> Destination<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span> <span class="operator">=</span> Source<span class="operator">[</span><span class="number">0..31</span><span class="operator">]</span><span class="operator">;</span>
<span class="keyword">if</span><span class="operator">(</span><span class="operator">(</span>Destination<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span> <span class="operator">&amp;&amp;</span> Source<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Destination<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Source<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> Destination<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span> <span class="operator">&lt;=</span> Source<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span><span class="operator">)</span> Destination<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span> <span class="operator">=</span> Source<span class="operator">[</span><span class="number">32..63</span><span class="operator">]</span><span class="operator">;</span>
<span class="keyword">if</span><span class="operator">(</span><span class="operator">(</span>Destination<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span> <span class="operator">&amp;&amp;</span> Source<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Destination<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Source<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> Destination<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span> <span class="operator">&lt;=</span> Source<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span><span class="operator">)</span> Destination<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span> <span class="operator">=</span> Source<span class="operator">[</span><span class="number">64..95</span><span class="operator">]</span><span class="operator">;</span>
<span class="keyword">if</span><span class="operator">(</span><span class="operator">(</span>Destination<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span> <span class="operator">&amp;&amp;</span> Source<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span> <span class="operator">==</span> <span class="number">0.0</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Destination<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> IsSNaN<span class="operator">(</span>Source<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span><span class="operator">)</span> <span class="operator">||</span> Destination<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span> <span class="operator">&lt;=</span> Source<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span><span class="operator">)</span> Destination<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span> <span class="operator">=</span> Source<span class="operator">[</span><span class="number">96..127</span><span class="operator">]</span><span class="operator">;</span>
</pre>
</td>
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<object>
<table class="box">
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<th>SIMD Floating-Point Exceptions</th>
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<tr>
<td class="instruction_set_reference_box">
<div>
<table class="operations_table">
<tr><td><code>Invalid</code></td><td>(including QNaN source operand), Denormal.</td></tr>
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<table class="box">
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<th>Protected Mode Exceptions</th>
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<td class="instruction_set_reference_box">
<div>
<table class="operations_table">
<tr><td><code>#GP(0)</code></td><td>For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments. If a memory operand is not aligned on a 16-byte boundary, regardless of segment.</td></tr>
<tr><td><code>#GP(0)</code></td><td>For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments. If a memory operand is not aligned on a 16-byte boundary, regardless of segment.</td></tr>
<tr><td><code>#SS(0)</code></td><td>If a memory operand effective address is outside the SS segment limit.</td></tr>
<tr><td><code>#PF(fault-code)</code></td><td>For a page fault.</td></tr>
<tr><td><code>#NM</code></td><td>If TS in CR0 is set.</td></tr>
<tr><td><code>#XM</code></td><td>If an unmasked SIMD floating-point exception and OSXMMEXCPT in CR4 is 1.</td></tr>
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</td>
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<object>
<table class="box">
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<th>Real-Address Mode Exceptions</th>
</tr>
<tr>
<td class="instruction_set_reference_box">
<div>
<table class="operations_table">
<tr><td><code>#GP(0)</code></td><td>If a memory operand is not aligned on a 16-byte boundary, regardless of segment. If any part of the operand lies outside the effective address space from 0 to FFFFH.</td></tr>
<tr><td><code>#GP(0)</code></td><td>If a memory operand is not aligned on a 16-byte boundary, regardless of segment. If any part of the operand lies outside the effective address space from 0 to FFFFH.</td></tr>
<tr><td><code>#NM</code></td><td>If TS in CR0 is set.</td></tr>
<tr><td><code>#XM</code></td><td>If an unmasked SIMD floating-point exception and OSXMMEXCPT in CR4 is 1.</td></tr>
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</td>
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<object>
<table class="box">
<tr>
<th>Virtual-8086 Mode Exceptions</th>
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<tr>
<td class="instruction_set_reference_box">
Same exceptions as in Real Address Mode
<div>
<table class="operations_table">
<tr><td><code>#PF(fault-code)</code></td><td>For a page fault.</td></tr>
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</td>
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</object>
<object>
<table class="box">
<tr>
<th>Instruction</th>
<th>Latency</th>
<th>Throughput</th>
<th>Execution Unit</th>
</tr>
<tr><td class="grid"><code>CPUID</code></td><td class="grid">0F3n/0F2n</td><td class="grid">0F3n/0F2n</td><td class="grid">0F2n</td></tr>
<tr><td class="grid"><code>MAXPS xmm, xmm</code></td><td class="grid">5/4</td><td class="grid">2/2</td><td class="grid">FP_ADD</td></tr>
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