[Bug tree-optimization/21574] New: store_ccp doesn't see through a store.

["kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

Consider:

int
foo (int *p)
{
  *p = 0;
  return *p;
}

Here is what I get after store_ccp (with -fno-tree-dominator-opts)

foo (p)
{
  int D.1233;

<bb 0>:
  #   TMT.0_5 = V_MAY_DEF <TMT.0_4>;
  *p_1 = 0;
  #   VUSE <TMT.0_5>;
  D.1233_2 = *p_1;
  return D.1233_2;

}

Note that the return statement isn't changed to "return 0;".

-- 
           Summary: store_ccp doesn't see through a store.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: dnovillo at redhat dot com,gcc-bugs at gcc dot gnu dot
                    org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21574