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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [X86] What AVX512 cpus should prefer 512-bit vectors?"
href="https://bugs.llvm.org/show_bug.cgi?id=48336">48336</a>
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<th>Summary</th>
<td>[X86] What AVX512 cpus should prefer 512-bit vectors?
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<th>Product</th>
<td>libraries
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Backend: X86
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>llvm-dev@redking.me.uk
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<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, pengfei.wang@intel.com, peter@cordes.ca, spatel+llvm@rotateright.com
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<pre>All avx512 capable Skylake CPUs and later currently prefer 256-bit vs 512-bit
vector generation - only the Knights Landing family always prefers 512-bit
(very different arch, no VLX support etc.).
AFAICT many of the frequency throttling issues with 512-bit ops were already
addressed by/after Icelake - so do we need to alter the tuning for later cpus
to let them vectorize to the full 512-bit alu width?</pre>
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