[Bug tree-optimization/79408] Missed VRP optimization of integer modulo

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79408

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Feb  8 09:21:57 2017
New Revision: 245273

URL: https://gcc.gnu.org/viewcvs?rev=245273&root=gcc&view=rev
Log:
        PR tree-optimization/79408
        * tree-vrp.c (simplify_div_or_mod_using_ranges): If op1 is not
        constant, but SSA_NAME with a known integer range, use the minimum
        of that range instead of op1 to determine if modulo can be replaced
        with its first operand.

        * gcc.dg/tree-ssa/pr79408.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr79408.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c