[Bug c/80632] error: invalid PHI argument with -O2

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80632

--- Comment #2 from David Binderman <dcb314 at hotmail dot com> ---
Reduced code:

a;
b() {
  int c;
  if (d()) {
    e();
    switch (a) {
    case 0:
      c = 1;
      break;
    case 1:
      c = 0;
      break;
    case 2:
      c = 0;
      break;
    case 3:
      c = 0;
      break;
    default:
      c = 1;
    }
  }
  return c;
}