[Bug tree-optimization/111764] New: Wrong code at -O3 on x86_64-linux-gnu since r11-5965-g04bff1bbfc1

["shaohua.li at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111764

            Bug ID: 111764
           Summary: Wrong code at -O3 on x86_64-linux-gnu since
                    r11-5965-g04bff1bbfc1
           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 -O3 produced the wrong code.

Bisected to r11-5965-g04bff1bbfc1

Compiler explorer: https://godbolt.org/z/7vaqadYfP

$ cat a.c
int printf(const char *, ...);
char a;
short b, c;
static short *d = &b, *e = &b;
short(f)(short g, short h) { return g * h; }
int main() {
  *e = 2;
  a = 1;
  for (; a <= 9; a++) {
    short *i = &c;
    *i = *d = f(*e, *e);
  }
  printf("%d\n", c);
}
$
$ gcc -O0 a.c && ./a.out
0
$ gcc -O3 a.c && ./a.out
4
%