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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [AVX512] Incorrect disassembly for EVEX-encoded instructions"
href="https://bugs.llvm.org/show_bug.cgi?id=37712">37712</a>
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<th>Summary</th>
<td>[AVX512] Incorrect disassembly for EVEX-encoded instructions
</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>
</tr>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Backend: X86
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
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<th>Reporter</th>
<td>maks@fb.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<p>
<div>
<pre>To reproduce:
$ echo 'vgatherqps 0x0(%r13,%zmm4,1),%ymm5{%k2}' | llvm-mc -assemble
-arch=x86-64 -show-encoding -x86-asm-syntax=att -mcpu=knl
.text
vgatherqps (%r13,%zmm4), %ymm5 {%k2} # encoding:
[0x62,0xd2,0x7d,0x4a,0x93,0x6c,0x25,0x00]
$ echo '0x62,0xd2,0x7d,0x4a,0x93,0x6c,0x25,0x00' | llvm-mc -disassemble
-arch=x86-64 -show-encoding -x86-asm-syntax=att -mcpu=knl
.text
vgatherqps (%r13,%ymm3), %ymm5 {%k2} # encoding:
[0x62,0xd2,0x7d,0x4a,0x93,0x6c,0x1d,0x00]
Notice the change from %zmm4 to %ymm3. Seems like decoding of VSIB index
register is broken.</pre>
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