[Bug tree-optimization/69160] [6 Regression] ICE in vect_get_vec_def_for_operand, at tree-vect-stmts.c:1436

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69160

--- Comment #2 from ktkachov at gcc dot gnu.org ---
A much smaller reduced testcase ICEs at -O3:

a, b, c;
fn1() {
  for (;;) {
    int *d;
    fn2();
    c = 0;
    for (; c <= 3; c++) {
      *d ^= 9;
      b = 0;
      for (; b <= 3; b++)
        *d ^= a;
    }
  }
}