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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [AVX512] incorrect register in vpbroadcastb instruction"
href="https://bugs.llvm.org/show_bug.cgi?id=33795">33795</a>
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<th>Summary</th>
<td>[AVX512] incorrect register in vpbroadcastb instruction
</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>All
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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>Backend: X86
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>babokin@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<p>
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<pre>Created <span class=""><a href="attachment.cgi?id=18794" name="attach_18794" title="reproducer">attachment 18794</a> <a href="attachment.cgi?id=18794&action=edit" title="reproducer">[details]</a></span>
reproducer
clang trunk, x86 (32 bit mode).
Clang generates "vpbroadcastb %ch, %xmm1" instruction (at least it intends
doing so). The instruction consumes 8 bit from general purpose register, but
only 32 registers are allowed. As a result, clang tries to encode
"vpbroadcastb %ch, %xmm1" as 62 f2 7d 08 7a cd, which really is
"vpbroadcastb %ebp,%zmm1".
I assume instruction description is incorrect.
The instruction was generated by "Machine Instruction Scheduler on function"
pass, if this matters.
Reproducer isn't really small, check "run" file for instruction for compiling
it, they should be self explanatory.
Let me know if more details are needed.</pre>
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