https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111631
Bug ID: 111631
Summary: Wrong code at -Os on x86_64-linux-gnu since
r14-3217-g4d6132e5932
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: shaohua.li at inf dot ethz.ch
CC: rguenth at gcc dot gnu.org
Target Milestone: ---
gcc at -Os produced the wrong code.
Bisected to r14-3217-g4d6132e5932
Compiler explorer: https://godbolt.org/z/Yj9bq1ecs
$ cat a.c
int printf(const char *, ...);
short a, f, i;
static const int *e;
short *g;
long h;
int main() {
{
unsigned j = i;
a = 1;
for (; a; a++) {
{
long b = j, d = h;
int c = 0;
while (d--)
*(char *)b++ = c;
}
if (e)
break;
}
j && (*g)--;
const int **k = &e;
*k = 0;
}
printf("%d\n", f);
}
$
$ gcc -O0 a.c && ./a.out
0
$ gcc -Os a.c && ./a.out
Segmentation fault
$ gcc -fsanitize=address,undefined a.c && ./a.out
0
$
