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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - extraneous dynamic swizzle when all lanes are equal and constant"
href="https://bugs.llvm.org/show_bug.cgi?id=49527">49527</a>
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<th>Summary</th>
<td>extraneous dynamic swizzle when all lanes are equal and constant
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<th>Product</th>
<td>new-bugs
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<th>Version</th>
<td>11.0
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>new bugs
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>danielwatson311@gmail.com
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<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
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<p>
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<pre>When the vector being shuffled has equal elements/lanes, LLVM should skip the
shuffle/swizzle.
As far as I can tell this only affects dynamic swizzles like AVX2's VPERMD and
does not affect constant shuffles like SHUFPS.
VPERMD: <a href="https://godbolt.org/z/eeKWfx">https://godbolt.org/z/eeKWfx</a>
shufflevector: <a href="https://godbolt.org/z/9b6r7x">https://godbolt.org/z/9b6r7x</a></pre>
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