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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 - Incorrect 'icmp sle' -> 'icmp slt' w/ vectors"
href="https://bugs.llvm.org/show_bug.cgi?id=43730">43730</a>
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<th>Summary</th>
<td>Incorrect 'icmp sle' -> 'icmp slt' w/ vectors
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<th>Product</th>
<td>libraries
</td>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>All
</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>Keywords</th>
<td>miscompilation
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Scalar Optimizations
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>nunoplopes@sapo.pt
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<th>CC</th>
<td>lebedev.ri@gmail.com, llvm-bugs@lists.llvm.org, regehr@cs.utah.edu, spatel+llvm@rotateright.com
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<pre>This transformation exposed in Transforms/InstCombine/icmp-vec.ll is incorrect.
The issue is that "INT_MIN <= undef" is not the same as "INT_MIN < undef".
define <2 x i1> @PR27756_2(<2 x i8> %a) {
%cmp = icmp sle <2 x i8> %a, { undef, 0 }
ret <2 x i1> %cmp
}
=>
define <2 x i1> @PR27756_2(<2 x i8> %a) {
%cmp = icmp slt <2 x i8> %a, { undef, 1 }
ret <2 x i1> %cmp
}
Transformation doesn't verify!
ERROR: Value mismatch
Example:
<2 x i8> %a = < #x80 (128, -128), #x80 (128, -128) >
Source:
<2 x i1> %cmp = < #x1 (1), #x1 (1) >
Target:
<2 x i1> %cmp = < #x0 (0), #x1 (1) >
Source value: < #x1 (1), #x1 (1) >
Target value: < #x0 (0), #x1 (1) ></pre>
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