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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 (both 32-bit and 64-bit modes)"
href="http://llvm.org/bugs/show_bug.cgi?id=16552">16552</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -O3 on x86_64-linux-gnu (both 32-bit and 64-bit modes)
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</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>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 the current clang trunk and clang 3.3 on
x86_64-linux-gnu at -O3 in both 32-bit and 64-bit modes. This is a regression
from clang 3.2.
Perhaps a different vectorizer bug as 16522?
$ clang-trunk -v
clang version 3.4 (trunk 185684)
Target: x86_64-pc-linux-gnu
Thread model: posix
$ clang-trunk -O3 reduced.c
$ a.out
0
$ clang-3.3 -O3 reduced.c
$ a.out
0
$ clang-3.2 -O3 reduced.c
$ a.out
1
$
--------------------------------------------
int printf (const char *, ...);
int a = 1, b, d;
unsigned char c;
int
foo ()
{
b |= 1;
return a;
}
void
bar ()
{
l:d = foo () && --c;
if (c)
goto l;
}
int
main ()
{
bar ();
printf ("%d\n", b);
return 0;
}</pre>
</div>
</p>
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