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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - wrong code at -O0 in 32-bit mode (affecting all clang versions on x86_64-linux-gnu and MacOS X)"
href="http://llvm.org/bugs/show_bug.cgi?id=17338">17338</a>
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<th>Summary</th>
<td>wrong code at -O0 in 32-bit mode (affecting all clang versions on x86_64-linux-gnu and MacOS X)
</td>
</tr>
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<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>LLVM Codegen
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>su@cs.ucdavis.edu
</td>
</tr>
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>The following code is miscompiled by the current clang trunk (and older
versions) on x86_64-linux-gnu at -O0 in 32-bit mode.
It also affects MacOS X.
The issue seems to be how the long long literal 0xFFFFFFFFLL is handled.
$ clang-trunk -v
clang version 3.4 (trunk 191183)
Target: x86_64-pc-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.3
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
$
$ clang-trunk -m32 -O0 small.c; a.out
0
$ clang-trunk -m32 -O1 small.c; a.out
1
$ clang-3.3 -m32 -O0 small.c; a.out
0
$ clang-3.2 -m32 -O0 small.c; a.out
0
$ gcc-trunk -m32 -O0 small.c; a.out
1
$ icc -m32 -O0 small.c; a.out
1
$
-----------------------------------------
int printf (const char *, ...);
int main ()
{
long long t = -1;
int a = (0xFFFFFFFFLL & t) > 0;
printf ("%d\n", a);
return 0;
}</pre>
</div>
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