[Bug tree-optimization/103798] memchr with a (small) constant string should be expanded inline.

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103798

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <h...@gcc.gnu.org>:

https://gcc.gnu.org/g:c6cf555a88f8ffb8ec85c2b94fe656ab217260ea

commit r13-1699-gc6cf555a88f8ffb8ec85c2b94fe656ab217260ea
Author: H.J. Lu <hjl.to...@gmail.com>
Date:   Fri Jun 17 07:33:06 2022 -0700

    Simplify memchr with small constant strings

    When memchr is applied on a constant string of no more than the bytes of
    a word, simplify memchr by checking each byte in the constant string.

    int f (int a)
    {
       return  __builtin_memchr ("AE", a, 2) != 0;
    }

    is simplified to

    int f (int a)
    {
      return ((char) a == 'A' || (char) a == 'E') != 0;
    }

    gcc/

            PR tree-optimization/103798
            * tree-ssa-forwprop.cc: Include "tree-ssa-strlen.h".
            (simplify_builtin_call): Inline memchr with constant strings of
            no more than the bytes of a word.
            * tree-ssa-strlen.cc (use_in_zero_equality): Make it global.
            * tree-ssa-strlen.h (use_in_zero_equality): New.

    gcc/testsuite/

            PR tree-optimization/103798
            * c-c++-common/pr103798-1.c: New test.
            * c-c++-common/pr103798-2.c: Likewise.
            * c-c++-common/pr103798-3.c: Likewise.
            * c-c++-common/pr103798-4.c: Likewise.
            * c-c++-common/pr103798-5.c: Likewise.
            * c-c++-common/pr103798-6.c: Likewise.
            * c-c++-common/pr103798-7.c: Likewise.
            * c-c++-common/pr103798-8.c: Likewise.
            * c-c++-common/pr103798-9.c: Likewise.
            * c-c++-common/pr103798-10.c: Likewise.