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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [LoopVectorizer] TTI query triggers assertion "Packing must reduce size of vector type.""
href="https://bugs.llvm.org/show_bug.cgi?id=49201">49201</a>
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<th>Summary</th>
<td>[LoopVectorizer] TTI query triggers assertion "Packing must reduce size of vector type."
</td>
</tr>
<tr>
<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>Linux
</td>
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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>Loop Optimizer
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>paulsson@linux.vnet.ibm.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=24535" name="attach_24535" title="reduced testcase">attachment 24535</a> <a href="attachment.cgi?id=24535&action=edit" title="reduced testcase">[details]</a></span>
reduced testcase
LV handles this instruction:
%i16.lhs.trunc = trunc i32 %i12 to i8
by calling TTI.getCastInstrCost() for a
trunc <2 x i1> to <2 x i8>,
which is broken and causes an assert in SystemZTTIImpl to fail: "Packing must
reduce size of vector type."
The user of the trunc is an icmp, which may possibly explain the precence of
'i1'...
opt -mtriple=s390x-unknown-linux -mcpu=z14 -o out.opt.ll -O2 -S
tc_crash14_aftercreduce.ll
llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp:596: unsigned int
llvm::SystemZTTIImpl::getVectorTruncCost(llvm::Type*, llvm::Type*): Assertion
`SrcTy->getPrimitiveSizeInBits().getFixedSize() > DstTy
->getPrimitiveSizeInBits().getFixedSize() && "Packing must reduce size of
vector type."' failed.</pre>
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