[Bug tree-optimization/50204] New: [4.5/4.6/4.7 Regression] Missed fully redundant load found in crafty (SPEC 2k)

["pinskia at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50204

             Bug #: 50204
           Summary: [4.5/4.6/4.7 Regression] Missed fully redundant load
                    found in crafty (SPEC 2k)
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: pinskia@gcc.gnu.org


Simplified testcase:
extern int opening;
extern int middle_game;
int s;
extern int d[1];
void PreEvaluate(int wtm)
{
  int i, j;
  if (opening) {
    d[0]=1;
  }
  else if (middle_game) {
    d[0]=-1;
  }
  if (4 != opening) {
    return;
  }
  s = 1;
}
--- CUT ---
4.3 catches the load of opening but 4.6 does not (4.5 does not either).