[Bug tree-optimization/78343] [6/7 Regression] Loop is not eliminated

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78343

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov 25 10:22:57 2016
New Revision: 242872

URL: https://gcc.gnu.org/viewcvs?rev=242872&root=gcc&view=rev
Log:
2016-11-24  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/78343
        * passes.def: Add CD-DCE pass after loop splitting.
        * tree-ssa-dce.c (find_obviously_necessary_stmts): Move
        SCEV init/finalize ...
        (perform_tree_ssa_dce): ... here.  Deal with being
        executed inside the loop pipeline in aggressive mode.

        * gcc.dg/tree-ssa/sccp-2.c: New testcase.
        * gcc.dg/autopar/uns-outer-6.c: Adjust.
        * gcc.dg/tree-ssa/20030808-1.c: Likewise.
        * gcc.dg/tree-ssa/20040305-1.c: Likewise.
        * gcc.dg/vect/pr38529.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/sccp-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/passes.def
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/autopar/uns-outer-6.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/20030808-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/20040305-1.c
    trunk/gcc/testsuite/gcc.dg/vect/pr38529.c
    trunk/gcc/tree-ssa-dce.c