[Bug middle-end/47790] New: [4.5/4.6 Regression] optimize_bitfield_assignment_op no longer works in 4.5.x

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47790

           Summary: [4.5/4.6 Regression] optimize_bitfield_assignment_op
                    no longer works in 4.5.x
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: pins...@gcc.gnu.org


Created attachment 23391
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23391
Patch which needs testing but should fix it

Ever since expand-ssa was added optimize_bitfield_assignment_op no longer
works.  You can see the difference in the code generated in
gcc.c-torture/execute/20040629-1.c.