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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Merge 5b5dc2442ac7 into 11.0 release branch"
href="https://bugs.llvm.org/show_bug.cgi?id=46807">46807</a>
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<th>Summary</th>
<td>Merge 5b5dc2442ac7 into 11.0 release branch
</td>
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<th>Product</th>
<td>libraries
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
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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
</td>
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<th>Component</th>
<td>Backend: X86
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
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<th>Reporter</th>
<td>llvm-dev@redking.me.uk
</td>
</tr>
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<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
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<th>Blocks</th>
<td>46725
</td>
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<p>
<div>
<pre>Based off an investigation into a test case provided by Craig, we need to avoid
traversing the DAG inside getTargetShuffleMask - I investigated hasOneUse()
wrappers but this approach is safer and we have other shuffle decode/combines
that can handle more complex broadcast shuffle folds.
Craig - are you OK with this getting merged?
<a href="https://reviews.llvm.org/rG5b5dc2442ac7">https://reviews.llvm.org/rG5b5dc2442ac7</a>
[X86][AVX] getTargetShuffleMask - don't decode
VBROADCAST(EXTRACT_SUBVECTOR(X,0)) patterns.
getTargetShuffleMask is used by the various "SimplifyDemanded" folds so we
can't assume that the bypassed extract_subvector can be safely simplified -
getFauxShuffleMask performs a more general decode that allows us to more safely
catch many of these cases so the impact is minimal.</pre>
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</p>
<div id="referenced">
<hr style="border: 1px dashed #969696">
<b>Referenced Bugs:</b>
<ul>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - [meta] 11.0.0 Release Blockers"
href="https://bugs.llvm.org/show_bug.cgi?id=46725">Bug 46725</a>] [meta] 11.0.0 Release Blockers
</li>
</ul>
</div>
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