[Bug tree-optimization/71466] wrong code at -O3 on x86_64-linux-gnu

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71466

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r236831:

Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Fri May 27 16:32:38 2016 +0000

        * tree-ssa-threadedge.c: Remove include of tree-ssa-threadbackward.h.
        (thread_across_edge): Remove calls to find_jump_threads_backwards.
        * passes.def: Add jump threading passes before DOM/VRP.
        * tree-ssa-threadbackward.c (find_jump_threads_backwards): Change
        argument to a basic block from an edge.  Remove tests which are
        handled elsewhere.
        (pass_data_thread_jumps, class pass_thread_jumps): New.
        (pass_thread_jumps::gate, pass_thread_jumps::execute): New.
        (make_pass_thread_jumps): Likewise.
        * tree-pass.h (make_pass_thread_jumps): Declare.