<html>
<head>
<base href="https://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 -O2 and -O3 on x86_64-linux-gnu"
href="https://llvm.org/bugs/show_bug.cgi?id=25154">25154</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -O2 and -O3 on x86_64-linux-gnu
</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>llvm-bugs@lists.llvm.org
</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 3.7.x) on
x86_64-linux-gnu at -O2 and -O3 in both 32-bit and 64-bit modes.
This is a regression from 3.6.x.
$ clang-trunk -v
clang version 3.8.0 (trunk 250080)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/tools/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.2
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.1.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.1.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$
$ clang-trunk -Os small.c; ./a.out
$ clang-3.6 -O2 small.c; ./a.out
$
$ clang-trunk -O2 small.c
$ ./a.out
Aborted (core dumped)
$
$ clang-3.7.0 -O2 small.c
$ ./a.out
Aborted (core dumped)
$
----------------------------------------
#include <assert.h>
struct
{
int f0;
short f1;
short f2;
short f3;
} b, e;
int a, **c, f, *m, d, i, j, l, n;
short ****g;
void
fn1 ()
{
int o;
if (f)
{
for (; e.f0; e.f0++)
for (; d; d = 0)
*c = &o;
assert (a);
*m &= i | ((j == 0) == l) | n;
for (; b.f1 >= 0; b.f1++)
;
}
for (b.f3 = 0; b.f3 < 2; b.f3++)
{
short *****h = 0;
for (b.f2 = 0; b.f2; b.f2--)
h = &g;
assert (!h);
}
}
int
main ()
{
fn1 ();
if (b.f3 != 2)
__builtin_abort ();
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>