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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Failure to optimize generated tail call to memset"
href="https://bugs.llvm.org/show_bug.cgi?id=45968">45968</a>
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<th>Summary</th>
<td>Failure to optimize generated tail call to memset
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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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>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<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>void test(char *A)
{
for (int i = 0; i < 10000; ++i)
A[i] = 0;
}
With -O3, LLVM generates this :
test(char*):
push rax
mov edx, 10000
xor esi, esi
call memset
pop rax
ret
GCC manages to generate this :
test(char*):
mov edx, 10000
xor esi, esi
jmp memset</pre>
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