<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 on x86_64-linux-gnu (affecting trunk and 3.3)"
href="http://llvm.org/bugs/show_bug.cgi?id=18102">18102</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code on x86_64-linux-gnu (affecting trunk and 3.3)
</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>-New Bugs
</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 -Os and -O3 in 64-bit mode (but not 32-bit mode).
This is a regression from clang 3.2.
$ clang-trunk -v
clang version 3.5 (trunk 195973)
Target: x86_64-unknown-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 -O1 small.c; a.out
0
$ clang-trunk -O2 small.c; a.out
0
$ clang-3.2 -Os small.c; a.out
0
$
$ clang-trunk -Os small.c; a.out
1
$ clang-3.3 -Os small.c; a.out
1
$
----------------------------------
int printf (const char *, ...);
int a, b, c, d, f, g;
struct S0
{
char f0;
int f1;
int f2;
} e, u;
int
fn1 ()
{
return b;
}
int
fn2 ()
{
struct S0 j = { 0, 0, 1 };
e = j;
if (fn1 () >= 0)
{
e.f2 = 0;
j = u;
}
else
for (;;)
for (e.f2 = 0; e.f2 < 1;)
if (d)
return 0;
for (; j.f0; j.f0++)
{
if (g)
e.f1 = j.f1;
f = a || 1 >> c ? 0 >> c : 1;
}
return 0;
}
int
main ()
{
fn2 ();
printf ("%d\n", e.f2);
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>