[Bug tree-optimization/78496] [7/8 Regression] Missed opportunities for jump threading

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78496

--- Comment #9 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Author: law
Date: Sat May  6 15:03:40 2017
New Revision: 247721

URL: https://gcc.gnu.org/viewcvs?rev=247721&root=gcc&view=rev
Log:
        PR tree-optimization/78496
        * tree-vrp.c (simplify_assert_expr_using_ranges): New function.
        (simplify_stmt_using_ranges): Call it.
        (vrp_dom_walker::before_dom_children): Extract equivalences
        from an ASSERT_EXPR with an equality comparison against a
        constant.

        PR tree-optimization/78496
        * gcc.dg/tree-ssa/ssa-thread-16.c: New test.
        * gcc.dg/tree-ssa/ssa-thread-17.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-16.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-17.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c