[Bug tree-optimization/71335] [7 Regression] wrong code at -O2 and -O3 in 32-bit and 64-bit modes on x86_64-linux-gnu

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71335

--- Comment #5 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Author: law
Date: Fri Jun 10 16:23:06 2016
New Revision: 237312

URL: https://gcc.gnu.org/viewcvs?rev=237312&root=gcc&view=rev
Log:
        PR tree-optimization/71335
        * tree-ssa-threadbackward.c (profitable_jump_thread_path): Filter out
        zero length paths here.
        (convert_and_register_jump_thread_path): Remove hacks related to
        duplicated blocks in the jump thread path.
        (fsm_find_control_statement_thread_paths): Avoid putting the same
        block on the thread path twice, but ensure the thread path is
        unchanged from the caller's point of view.

        PR tree-optimization/71335
        * gcc.c-torture/execute/pr71335.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr71335.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-threadbackward.c