[Bug tree-optimization/61009] [4.9 Regression] Incorrect jump threading in dom

[tejohnson at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61009

--- Comment #12 from tejohnson at gcc dot gnu.org ---
Author: tejohnson
Date: Fri May  9 16:59:56 2014
New Revision: 210279

URL: http://gcc.gnu.org/viewcvs?rev=210279&root=gcc&view=rev
Log:
Backport r210254 from trunk for Google b/14380607.

    2014-05-08  Jeff Law  <l...@redhat.com>

    PR tree-optimization/61009
    * tree-ssa-threadedge.c (thread_through_normal_block): Return a
    tri-state rather than a boolean.  When a block is too big to
    thread through, inform caller via negative return value.
    (thread_across_edge): If a block was too big for normal threading,
    then it's too big for a joiner too, so remove temporary equivalences
    and return immediately.

    PR tree-optimization/61009
    * g++.dg/tree-ssa/pr61009.C: New test.

Added:
    branches/google/gcc-4_9/gcc/testsuite/g++.dg/tree-ssa/pr61009.C
Modified:
    branches/google/gcc-4_9/gcc/tree-ssa-threadedge.c