<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - wrong code at -O3 on x86_64-linux-gnu (in both 32-bit and 64-bit modes)"
href="http://llvm.org/bugs/show_bug.cgi?id=16463">16463</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -O3 on x86_64-linux-gnu (in 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>
<tr>
<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 (as well as clang 3.2
and 3.3) on x86_64-linux-gnu at -O3 in both 32-bit and 64-bit modes, resulting
in a SIGFPE.
$ clang-trunk -v
clang version 3.4 (trunk 184829)
Target: x86_64-pc-linux-gnu
Thread model: posix
$ clang-trunk -O2 reduced.c
$ a.out
$ clang-trunk -O3 reduced.c
$ a.out
Floating point exception (core dumped)
$ clang-3.3 -O3 reduced.c
$ a.out
Floating point exception (core dumped)
$ clang-3.2 -O3 reduced.c
$ a.out
Floating point exception (core dumped)
$
----------------------------------------------------
int a, b, d, e, f, g;
int * foo (int p)
{
b = -2;
for (; b; ++b)
for (; d; ++d) {
g = p == 0 ? 0 : 1 / p;
e = 0;
for (; e < 38; e++) {
g--;
if (a)
return 0;
}
}
return 0;
}
int main ()
{
foo (1 & f);
return 0;
}</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>