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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Missed fold for copysign on integers"
href="https://bugs.llvm.org/show_bug.cgi?id=49822">49822</a>
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<th>Summary</th>
<td>Missed fold for copysign on integers
</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>Scalar Optimizations
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>rifkin@purdue.edu
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>C++ has no std::sign function. std::copysign may be used for this functionality
with a call along the lines of: std::copysign(1, n).
When std::copysign is provided with an integer argument and the return value is
immediately cast to an integer, the copysign call can be folded away in favor
of an icmp/select pattern along the lines of that produced for (n < 0 ? -1 :
1).
Currently, the generated assembly for copysign includes an int -> float
conversion followed shortly by a float -> int conversion.
<a href="https://godbolt.org/z/MoPr9javo">https://godbolt.org/z/MoPr9javo</a></pre>
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</p>
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