<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 --- - non-terminating loops with optimization causes clang to hang"
href="http://llvm.org/bugs/show_bug.cgi?id=15386">15386</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>non-terminating loops with optimization causes clang to hang
</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>Linux
</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>dhazeghi@yahoo.com
</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 snippet causes top-of-trunk clang to get stuck in an infinite
loop when compiled at -O1 or higher. This is likely related to 15384, but that
bug only triggers at -O3.
$ clang-trunk -v
clang version 3.3 (trunk 172630)
Target: x86_64-pc-linux-gnu
Thread model: posix
$ cat loop.c
int a, b, c;
void f1 ()
{
for (; b; b++)
if (a)
a = 1;
for (b = 0; b != 1; b = b + (unsigned int) 2)
if (!a)
a = 0;
}
void f2 ()
{
for (;;);
}
void f3 ()
{
f2();
for (; c; c++)
f2();
f1();
}
int main ()
{
return 0;
}
$ clang-trunk -O1 loop.c
$ clang-trunk -Os loop.c
<hangs></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>