https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111000
Bug ID: 111000
Summary: Wrong code at -O3 on x86_64-linux-gnu since
r14-2944-g3d48c11ad08
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: ---
gcc at -O3 produces the wrong code.
Bisected to r14-2944-g3d48c11ad08
Compiler explorer: https://godbolt.org/z/b67W17Gvb
$ cat a.c
int printf(const char *, ...);
long a = 68;
int b, d, e;
int main() {
for (; d <= 6; d++) {
b = 0;
for (; b <= 6; b++) {
int c = a;
e = c >= 32 || d > 647 >> c ? d : 0;
}
}
printf("%d\n", e);
}
$
$ gcc -O0 a.c &&./a.out
6
$ gcc -O3 a.c && ./a.out
4
$
