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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Missed simplification (A|C)^(B|C) ->"
href="https://bugs.llvm.org/show_bug.cgi?id=46955">46955</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Missed simplification (A|C)^(B|C) ->
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>david.bolvansky@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>#define C 4
unsigned int test(unsigned int A, unsigned int B, unsigned int CC)
{
return (A|C)^(B|C);
}
unsigned int test2(unsigned int A, unsigned int B, unsigned int CC)
{
return (A^B)&~C;
}
Clang
test(unsigned int, unsigned int, unsigned int): #
@test(unsigned int, unsigned int, unsigned int)
mov eax, esi
or edi, 4
or eax, 4
xor eax, edi
ret
test2(unsigned int, unsigned int, unsigned int): #
@test2(unsigned int, unsigned int, unsigned int)
mov eax, edi
xor eax, esi
and eax, -5
ret
GCC
test(unsigned int, unsigned int, unsigned int):
xor esi, edi
mov eax, esi
and eax, -5
ret
test2(unsigned int, unsigned int, unsigned int):
xor edi, esi
mov eax, edi
and eax, -5
ret
<a href="https://godbolt.org/z/3McGvb">https://godbolt.org/z/3McGvb</a></pre>
</div>
</p>
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