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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 - [InstCombine] Failure to simplify (~A|B)^A --> ~(A&B)"
href="https://bugs.llvm.org/show_bug.cgi?id=52518">52518</a>
</td>
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<th>Summary</th>
<td>[InstCombine] Failure to simplify (~A|B)^A --> ~(A&B)
</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>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<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>jay.foad@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
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<div>
<pre>InstCombine should simplify (~A|B)^A --> ~(A&B).
Here's CompilerExplorer showing that (a) the transformation is valid according
to Alive2, and (b) "opt -O2" does not do it:
<a href="https://alive2.llvm.org/ce/#z:OYLghAFBqd5QCxAYwPYBMCmBRdBLAF1QCcAaPECAM1QDsCBlZAQwBtMQBGAFlICsupVs1qhWrAG4BbUgGdM7ZATx1KmWugDCqVgFcptLgFZS69ABk8tTADl9AI0zEQAdlIAHVLMIra2vQbGHl4%2BdJbWdlKOzm7yisp0DATMxAT%2B%2BoacJnGYSr5JKQThtg5OrnLJqemBWRWFxZHRrgCUcqi6xMgcAORYVFaYANR43IMAAgTABBAjgwCkAExGAAykw6OLRpzNg6yoLKwA%2Brq0tMxSmOiHzOjoxPMLAMzL8y4AQnPLAIL29iCfX0GDyMC3mjwAIoMROh1sDOGtNssAUDNo8wZCAB4kWGbBZrAC0nGRg2ImAIOKWjwBcxc4IBfQGsLGsk6Mw2S1WFK2Oz2B2Op3Ol2ut3ui2erw%2B31%2B/2%2BKKWoLmEMGWPus0RBKJsuBaMVkOxavlCKWmsBwI2SpVXMeRpWxNJ5INRm41NpAO6rVYIG6Rm6pEM3WWvtQXvM5gAagBZQYASQASoNZO1OkMxZxfQQvYHmq0ANYgFZCL3cX3%2BwOkYPdX2yECrDMB92kOCwGCIFCoKTuPDsMgUCBoDtdsqodwEUj9VgEJzViB/eukexWFIATy9adI/Yu9AA8rRWCu51gpCJgOxM778KS8hJMNW55gMbldJPV76rJPPXPWHh7MRl9osC%2BpAEMQeBSC%2BrQ0PQTBsBwPD8IIwiiCA4jSEI37VpArTDgktC3viW4LFWCi5DhagaNUmSmBoDSlM48KeN4OEUYIDGhLQNFRGU8I5HkiSVGkOgZIIPE4QUqQcU03H8cxUn1AMjRca0iYdF0XAel6Pp%2Bme5ZethgwQLghDYqmazaAO3YPI82yDKGkYxrG6ZntmpAIJgNxlBAub5qsH7FqQYEFqWQZelWNZAU5jYthASD9p23bkJQsWDs4bB4NeY5dpOxDTrOZYLmcxD7muG7qAQO57tph7HqeB54JeyjXreZb3o%2Bz7dGub4KNpX4/n%2BGA9GuwGgeBY50IwBywbwAh4ohYiSDIPUYZ55Yjr4t5EfEvhkVogk1FRFjybRLEhExu2UaxOESVxcjEbxtBiQJASUSJ%2BT8VddF1FUZ3CW9h2cXRSlJqp2yFt6JbaRWqXXviBASPphlEKKTzwoMZlxU4lkLDstlRnGjn1s5rnuc4y2%2Bb6AWrEFOmVnIYV1lmXkFh%2Bjzg3OFb4wzoOEVpbMheFBOtNe2VbdwQA%3D%3D%3D">https://alive2.llvm.org/ce/#z:OYLghAFBqd5QCxAYwPYBMCmBRdBLAF1QCcAaPECAM1QDsCBlZAQwBtMQBGAFlICsupVs1qhWrAG4BbUgGdM7ZATx1KmWugDCqVgFcptLgFZS69ABk8tTADl9AI0zEQAdlIAHVLMIra2vQbGHl4%2BdJbWdlKOzm7yisp0DATMxAT%2B%2BoacJnGYSr5JKQThtg5OrnLJqemBWRWFxZHRrgCUcqi6xMgcAORYVFaYANR43IMAAgTABBAjgwCkAExGAAykw6OLRpzNg6yoLKwA%2Brq0tMxSmOiHzOjoxPMLAMzL8y4AQnPLAIL29iCfX0GDyMC3mjwAIoMROh1sDOGtNssAUDNo8wZCAB4kWGbBZrAC0nGRg2ImAIOKWjwBcxc4IBfQGsLGsk6Mw2S1WFK2Oz2B2Op3Ol2ut3ui2erw%2B31%2B/2%2BKKWoLmEMGWPus0RBKJsuBaMVkOxavlCKWmsBwI2SpVXMeRpWxNJ5INRm41NpAO6rVYIG6Rm6pEM3WWvtQXvM5gAagBZQYASQASoNZO1OkMxZxfQQvYHmq0ANYgFZCL3cX3%2BwOkYPdX2yECrDMB92kOCwGCIFCoKTuPDsMgUCBoDtdsqodwEUj9VgEJzViB/eukexWFIATy9adI/Yu9AA8rRWCu51gpCJgOxM778KS8hJMNW55gMbldJPV76rJPPXPWHh7MRl9osC%2BpAEMQeBSC%2BrQ0PQTBsBwPD8IIwiiCA4jSEI37VpArTDgktC3viW4LFWCi5DhagaNUmSmBoDSlM48KeN4OEUYIDGhLQNFRGU8I5HkiSVGkOgZIIPE4QUqQcU03H8cxUn1AMjRca0iYdF0XAel6Pp%2Bme5ZethgwQLghDYqmazaAO3YPI82yDKGkYxrG6ZntmpAIJgNxlBAub5qsH7FqQYEFqWQZelWNZAU5jYthASD9p23bkJQsWDs4bB4NeY5dpOxDTrOZYLmcxD7muG7qAQO57tph7HqeB54JeyjXreZb3o%2Bz7dGub4KNpX4/n%2BGA9GuwGgeBY50IwBywbwAh4ohYiSDIPUYZ55Yjr4t5EfEvhkVogk1FRFjybRLEhExu2UaxOESVxcjEbxtBiQJASUSJ%2BT8VddF1FUZ3CW9h2cXRSlJqp2yFt6JbaRWqXXviBASPphlEKKTzwoMZlxU4lkLDstlRnGjn1s5rnuc4y2%2Bb6AWrEFOmVnIYV1lmXkFh%2Bjzg3OFb4wzoOEVpbMheFBOtNe2VbdwQA%3D%3D%3D</a></pre>
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