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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [dagcombine] redundant 'and' of phi node not removed during isel"
href="https://llvm.org/bugs/show_bug.cgi?id=25592">25592</a>
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<th>Summary</th>
<td>[dagcombine] redundant 'and' of phi node not removed during isel
</td>
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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>All
</td>
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<th>OS</th>
<td>All
</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>Common Code Generator Code
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>gberry@codeaurora.org
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<th>Classification</th>
<td>Unclassified
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<p>
<div>
<pre>SelectionDAGBuilder seems to remove redundant 'and' nodes in some cases but not
others.
test/CodeGen/AArch64/free-zext.ll has two cases that demonstrate this. The
first, test_free_zext3 demonstrates that the 'and' made redundant by
CodeGenPrepare (in bb3) is removed. In the second test, test_free_zext4, the
'and' of the phi value in the loop block is not removed. See the TODO comment
in this test for a CHECK-NOT that can be enabled if this issue is resolved.
This issue was discovered during development of the following change:
<a href="http://reviews.llvm.org/D14584">http://reviews.llvm.org/D14584</a></pre>
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