[Bug tree-optimization/48317] New: SCCVN does not handle vector constructors

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48317

           Summary: SCCVN does not handle vector constructors
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: rgue...@gcc.gnu.org


SCCVN does not handle CONSTRUCTORs well (they simply get put into a
reference-kind
single operand).  This sucks for things like

  vect_cst_.239_4355 = {pretmp.88_1931, pretmp.88_1931};

which the vectorizer generates (or which can happen via intrinsics or
generic vector support even earlier).

Not sure how to handle this variable-size code though.