https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77766
Bug ID: 77766
Summary: wrong code at -O2 and -O3 in 64-bit mode on
x86_64-linux-gnu (executable hangs)
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: chengniansun at gmail dot com
Target Milestone: ---
$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.0 20160927 (experimental) [trunk revision 240545] (GCC)
$
$ gcc-trunk -O2 small.c
$ timeout -s 9 10 ./a.out
Killed
$ gcc-trunk -Os small.c
$ ./a.out
$
$ cat small.c
char a;
short b, d = 5, h;
char c[1];
int e, f = 4, g, j;
int main() {
int i;
for (; f; f = a) {
g = 0;
for (; g <= 32; ++g) {
i = 0;
for (; i < 3; i++)
while (1 > d)
if (c[b])
break;
L:
if (j)
break;
}
}
e = 0;
for (; e; e = 0) {
d++;
for (; h;)
goto L;
}
return 0;
}
$
