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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - wrong code at -O3 on x86_64-linux-gnu"
href="http://llvm.org/bugs/show_bug.cgi?id=17074">17074</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -O3 on x86_64-linux-gnu
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>LLVM Codegen
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>su@cs.ucdavis.edu
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>The following code is miscompiled by current clang trunk and 3.3 on
x86_64-linux-gnu at -O3 (in both 32-bit and 64-bit modes).
This is a regression from 3.2.
$ clang-trunk -v
clang version 3.4 (trunk 189735)
$ clang-trunk -O2 reduced.c
$ a.out
1
$ clang-trunk -O3 reduced.c
$ a.out
7
$ clang-3.3 -O3 reduced.c
$ a.out
7
$ clang-3.2 -O3 reduced.c
$ a.out
1
$
--------------------------------
int printf (const char *, ...);
int a, b = 7;
char c;
int main ()
{
lbl:
{
int *d = &b;
*d &= 1;
c--;
if (a)
;
else if (c)
goto lbl;
}
printf ("%d\n", b);
return 0;
}</pre>
</div>
</p>
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