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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Redundant mov in a simple tail call"
href="https://bugs.llvm.org/show_bug.cgi?id=37675">37675</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Redundant mov in a simple tail call
</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>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<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>Backend: X86
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>hans@chromium.org
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Blocks</th>
<td>26299
</td>
</tr></table>
<p>
<div>
<pre>Consider the following:
void f(void*, int);
void g(void *p, void *q, int x) {
return f(q, 0);
}
clang -Os:
g:
movq %rsi, %rax <--- Why not mov to %rdi directly?
xorl %esi, %esi
movq %rax, %rdi
jmp f
gcc -Os:
g:
movq %rsi, %rdi
xorl %esi, %esi
jmp f</pre>
</div>
</p>
<div id="referenced">
<hr style="border: 1px dashed #969696">
<b>Referenced Bugs:</b>
<ul>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - [meta][X86] Size optimization opportunities (in particular for 32-bit Chromium on Windows)"
href="https://bugs.llvm.org/show_bug.cgi?id=26299">Bug 26299</a>] [meta][X86] Size optimization opportunities (in particular for 32-bit Chromium on Windows)
</li>
</ul>
</div>
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