[Bug tree-optimization/80641] missed optimization with with std::vector resize in loop

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80641

--- Comment #15 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is interesting:
  _48 = _149 + 18446744073709551612; // _149 - 4
  _63 = _55 + _48;
  _18 = _63 - _55;
  _19 = _18 /[ex] 4;
  _20 = (long unsigned int) _19;
  if (_55 != _63)

_18 should be the same as _48
and the if statement should be if (_48 != 0)