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<head>
<base href="https://llvm.org/bugs/" />
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<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 -Os and above on x86_64-linux-gnu"
href="https://llvm.org/bugs/show_bug.cgi?id=25225">25225</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code at -Os and above 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 -Os and above in both 32-bit and 64-bit modes.
This is a regression from 3.7.x.
The reduced test is still quite large, but it seems difficult to reduce it
further.
$ clang-trunk -v
clang version 3.8.0 (trunk 250539)
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 -O1 small.c; ./a.out
$ clang-3.7.0 -Os small.c; ./a.out
$
$ clang-trunk -Os small.c
$ ./a.out
Aborted (core dumped)
$
-------------------------------------
int a = -1, *b = &a, f, l;
static short c, d, *e = &d;
static char g;
void fn1 () { }
void fn2 () { }
void fn3 () { }
void fn4 () { }
void fn5 () { }
void fn6 () { }
void fn7 () { }
void fn8 () { }
void fn9 () { }
void fn10 () { }
void fn11 () { }
void fn12 () { }
void fn13 () { }
void fn14 () { }
void fn15 () { }
void fn16 () { }
void fn17 () { }
void fn18 () { }
void fn19 () { }
void fn20 () { }
int fn21 (int p1) { return p1; }
void fn22 () { }
void fn23 () { }
void fn24 () { }
void fn25 () { }
void fn26 () { }
void fn27 () { }
void fn28 () { }
void fn29 () { }
void fn30 () { }
void fn31 () { }
void fn32 () { }
void fn33 () { }
void fn34 () { }
void fn35 () { }
void fn36 () { }
void fn37 () { }
void fn38 () { }
static int
fn39 ()
{
if (d)
{
int h;
}
return 0;
}
static int
fn40 ()
{
short *i = &c;
*i = *e = 1;
if (a < 0)
__builtin_abort ();
return 0;
}
static int *fn41 (short);
void fn42 () { }
static int
fn43 ()
{
char *j = &g;
*j = 1;
return 0;
}
static int
fn44 ()
{
if (f)
fn41 (0);
l = 0;
return 0;
}
void fn45 () { }
static int
fn46 ()
{
fn41 (a);
fn40 ();
fn39 ();
fn21 (g);
return 0;
}
static int *
fn41 (short p1)
{
fn44 ();
fn43 ();
*b = p1 < 0;
return 0;
}
void fn47 () { }
int
main ()
{
if (c)
fn35 ();
fn46 ();
return 0;
}</pre>
</div>
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