<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 in 32-bit mode on x86_64-linux-gnu"
href="https://llvm.org/bugs/show_bug.cgi?id=27993">27993</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -O2 and -O3 in 32-bit mode 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 on
x86_64-linux-gnu at -O2 and -O3 in the 32-bit mode (but not in the 64-bit
mode).
This is a regression from 3.8.x.
$ clang-trunk -v
clang version 3.9.0 (trunk 271236)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
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/4.9.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
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 -m32 -Os small.c; ./a.out
$ clang-3.8 -m32 -O2 small.c; ./a.out
$ clang-trunk -m64 -O2 small.c; ./a.out
$
$ clang-trunk -m32 -O2 small.c
$ ./a.out
00
$
----------------------------------------------
int a = 1, c, d, e, f, g;
char h;
char
fn1 (char p1, int p2)
{
return p1 > 1 || p1 > p2 ? p1 : p1 << p2;
}
static int
fn2 (long long p1, char p2)
{
if (p1 < p2)
fn2 (f, f);
c = h;
return h;
}
int
fn3 ()
{
int i = fn1 (a, 3);
g = fn2 (a, a);
c = h;
return i;
}
int
main ()
{
if (fn3 () < 8)
__builtin_printf ("%d%d\n", d, e);
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>