[Bug tree-optimization/99997] Missed optimisation with -Os

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99997

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|rguenth at gcc dot gnu.org         |pinskia at gcc dot gnu.org

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Hmm,  phi-opt should have done it:

  if (_10 != 0)
    goto <bb 4>; [50.00%]
  else
    goto <bb 3>; [50.00%]

  <bb 3> [local count: 536870913]:
  _3 = page_2(D)->compound_head;
  _4 = (_Bool) _3;
  _11 = (int) _4;

  <bb 4> [local count: 1073741824]:
  # iftmp.0_5 = PHI <1(2), _11(3)>

We have code to move the conversion in phiopt but we are not doing it for some
reason:
Take:
bool f(int tf, long unsigned int r)
{
  int t = 1;
  if (tf)
    t = ((r&1)!=0);
  return t;
}
bool f2(int tf, long unsigned int r)
{
  int t = 1;
  bool tt = ((r&1)!=0);
  if (tf)
    t = tt;
  return t;
}
These two functions should produce 100% the same code but they don't.
Mine.