[Bug tree-optimization/82665] missing value range optimization for memchr

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82665

--- Comment #3 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Author: law
Date: Tue May  1 18:20:39 2018
New Revision: 259806

URL: https://gcc.gnu.org/viewcvs?rev=259806&root=gcc&view=rev
Log:
        PR tree-optimization/82665
        * vr-values.c (vr_values::extract_range_from_binary_expr): Handle
        pointer subtraction where arguments come from a memchr call.

        PR tree-optimization/82665
        * gcc.dg/tree-ssa/pr82665.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr82665.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/vr-values.c