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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - lowerVectorShuffleByMerging128BitLanes - Detected cycle in SelectionDAG"
href="https://bugs.llvm.org/show_bug.cgi?id=38639">38639</a>
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<th>Summary</th>
<td>lowerVectorShuffleByMerging128BitLanes - Detected cycle in SelectionDAG
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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
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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, douglas_yung@playstation.sony.com, greg.bedwell@sony.com, llvm-bugs@lists.llvm.org
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<pre>D41794 is causing this fuzz test regression:
define <8 x double> @test(<4 x double> %a, <4 x double> %b) {
%1 = shufflevector <4 x double> %a, <4 x double> <double undef, double
0x3FEA435134576E1C, double 0x3FEA435134576E1C, double 0x3FEA435134576E1C>, <8 x
i32> <i32 6, i32 5, i32 2, i32 3, i32 5, i32 1, i32 3, i32 7>
ret <8 x double> %1
}
llc -mcpu=btver2
Detected cycle in SelectionDAG
Offending node:
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26
t27: v4f64 = vector_shuffle<0,5,2,7> t27, t26</pre>
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