[Bug tree-optimization/58727] Sub-optimal code for bit clear/set sequence

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58727

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-10-14
     Ever confirmed|0                           |1

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It comes from:

      /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
         unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
         mode which allows further optimizations.  */