[Bug tree-optimization/18546] New: tree vectorizer does not understand RETURN_DECL

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

Compile the following with the C and C++ front-end and you will get different assembly, the C front-
end does not do NVR at all while the C++ front-end will change the a decl to be the return_decl before 
so we the vectorizer cannot do the vectorization because it does not hanndle RETURN_DECLs at all.

struct A
{
    int x[4];
};

struct A foo()
{
  struct A a;
  for (int i=0; i<4; ++i)
    a.x[i] = 0;
  return a;
}

-- 
           Summary: tree vectorizer does not understand RETURN_DECL
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18546