https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110243
Bug ID: 110243
Summary: Wrong code at -O3 on x86_64-linux-gnu
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: shaohua.li at inf dot ethz.ch
Target Milestone: ---
Since GCC-13, gcc at -O3 produces wrong code.
Compiler explorer: https://godbolt.org/z/jnroxhddY
$ cat a.c
#define X 1100000000
char a;
long b = X;
int c[9][1];
unsigned d;
static long *e = &b, *f = &b;
int g() {
if (a && a <= '9')
return '0';
if (a)
return 10;
return -1;
}
int main() {
d = 0;
for (; (int)*f -(X-1) + d < 9; d++)
c[g() + (int)*f + ((int)*e - X) -(X-1) + d]
[0] = 0;
}
$
$ gcc-tk -O3 a.c &&./a.out
Segmentation fault
$
$ gcc-tk -O0 a.c &&./a.out
$
$ gcc-tk -fsanitize=address,undefined a.c &&./a.out
$
$ gcc-tk -v
Using built-in specs.
COLLECT_GCC=gcc-tk
COLLECT_LTO_WRAPPER=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-bf470895905e9152424076d1630a9d2c60de023b/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --disable-multilib --disable-bootstrap
--enable-languages=c,c++
--prefix=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-bf470895905e9152424076d1630a9d2c60de023b
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230612 (experimental) (GCC)
$
