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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Failure to recognize bounds of sign function"
href="https://bugs.llvm.org/show_bug.cgi?id=45758">45758</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Failure to recognize bounds of sign function
</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>
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<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>gabravier@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>inline int sign(int x)
{
return (x >> 31) | ((unsigned)-x >> 31);
}
bool f(int x)
{
return (sign(x) >= -1) && (sign(x) <= 1);
}
`f` can be optimized to `return true;`. GCC does this transformation, but LLVM
does not.</pre>
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