[Bug target/88152] optimize SSE & AVX char compares with subsequent movmskb

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88152

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Thu Nov 29 14:32:00 2018
New Revision: 266620

URL: https://gcc.gnu.org/viewcvs?rev=266620&root=gcc&view=rev
Log:
        PR target/88152
        * tree.h (build_uniform_cst, uniform_integer_cst_p): Declare.
        * tree.c (build_uniform_cst, uniform_integer_cst_p): New functions.
        * match.pd (define_predicates): Add uniform_integer_cst_p.
        (cmp @0 INTEGER_CST@1, cmp (convert?@2 @0) INTEGER_CST@1): Adjust
        so that it works also for vector comparisons with uniform constants
        with INTEGER_CST element.

        * g++.dg/tree-ssa/pr88152-1.C: New test.
        * g++.dg/tree-ssa/pr88152-2.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/tree-ssa/pr88152-1.C
    trunk/gcc/testsuite/g++.dg/tree-ssa/pr88152-2.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree.c
    trunk/gcc/tree.h