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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [X86][AVX512VL] Infinite loop in bool vector sign extension"
href="https://bugs.llvm.org/show_bug.cgi?id=34553">34553</a>
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<th>Summary</th>
<td>[X86][AVX512VL] Infinite loop in bool vector sign extension
</td>
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<th>Product</th>
<td>libraries
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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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
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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>llvm-dev@redking.me.uk
</td>
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<th>CC</th>
<td>craig.topper@gmail.com, elena.demikhovsky@intel.com, llvm-bugs@lists.llvm.org, zvi.rackover@intel.com
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<pre>Found while working on D37680
-mtriple=x86_64-unknown -mattr=+avx512f,+avx512vl
define <16 x i8> @vselect_packss_v16i32(<16 x i32> %a0, <16 x i32> %a1, <16 x
i8> %a2, <16 x i8> %a3) {
%1 = icmp eq <16 x i32> %a0, %a1
%2 = sext <16 x i1> %1 to <16 x i8>
%3 = and <16 x i8> %2, %a2
%4 = xor <16 x i8> %2, <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8
-1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
%5 = and <16 x i8> %4, %a3
%6 = or <16 x i8> %3, %5
ret <16 x i8> %6
}
-mtriple=x86_64-unknown -mattr=+avx512f works OK:
vselect_packss_v16i32:
vpcmpeqd %zmm1, %zmm0, %k1
vpternlogd $255, %zmm0, %zmm0, %zmm0 {%k1} {z}
vpmovdb %zmm0, %xmm0
vpand %xmm2, %xmm0, %xmm1
vpandn %xmm3, %xmm0, %xmm0
vpor %xmm0, %xmm1, %xmm0
vzeroupper
retq
As does -mtriple=x86_64-unknown -mcpu=skx
vselect_packss_v16i32:
vpcmpeqd %zmm1, %zmm0, %k0
vpmovm2b %k0, %xmm0
vpblendvb %xmm0, %xmm2, %xmm3, %xmm0
vzeroupper
retq</pre>
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