[Bug tree-optimization/101150] [11/12/13 Regression] null pointer dereference false positive disappears when compiling an additional function

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101150

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection
      Known to work|                            |13.0

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
On the trunk, the warning is gone so is the missed optimization mentioned in
comment #1.

We do have another missed optimization though:
  _12 = _9 - _15;
  _7 = _12 /[ex] 4;
  _18 = (long unsigned int) _7;
  _120 = _18 != 0;
  _54 = _12 != 0;
  _127 = _54 & _120;
  if (_127 != 0)
    goto <bb 3>; [16.50%]
  else
    goto <bb 9>; [83.50%]
...
  <bb 9> [local count: 98623186]:
  if (_9 != _15)
    goto <bb 10>; [89.00%]
  else
    goto <bb 23>; [11.00%]

Only one of those comparisons is actually needed. and then another missing jump
threading because _9 be equal _15 on the goto <bb 9> branch.