[Bug tree-optimization/55869] different bit shift/or optimization.

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55869

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-01-04
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-04 10:36:52 UTC ---
In CCP we optimize this to

  <bb 2>:
  if (flag_2(D) != 0)
    goto <bb 4>;
  else
    goto <bb 3>;

  <bb 3>:

  <bb 4>:
  # iftmp.0_1 = PHI <144115188075855872(2), 0(3)>
  return iftmp.0_1;

before phiopt can apply valueization of flag ? 1 : 0.