[Bug middle-end/109986] missing fold (~a | b) ^ a => ~(a & b)

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109986

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:2a3556376c69a1fb588dcf25225950575e42784f

commit r14-2751-g2a3556376c69a1fb588dcf25225950575e42784f
Author: Drew Ross <drross@redhat.com>
Date:   Mon Jul 24 17:51:28 2023 +0200

    match.pd: Implement missed optimization (~X | Y) ^ X -> ~(X & Y) [PR109986]

    Adds a simplification for (~X | Y) ^ X to be folded into ~(X & Y).
    Also adds the macro bitwise_equal_p for generic and gimple which
    returns true iff EXPR1 and EXPR2 have the same value. This helps
    to reduce the number of nop_converts necessary to match the pattern.

            PR middle-end/109986

    gcc/ChangeLog:

            * generic-match-head.cc (bitwise_equal_p): New macro.
            * gimple-match-head.cc (bitwise_equal_p): New macro.
            (gimple_nop_convert): Declare.
            (gimple_bitwise_equal_p): Helper for bitwise_equal_p.
            * match.pd ((~X | Y) ^ X -> ~(X & Y)): New simplification.

    gcc/testsuite/ChangeLog:

            * gcc.c-torture/execute/pr109986.c: New test.
            * gcc.dg/tree-ssa/pr109986.c: New test.

    Co-authored-by: Jakub Jelinek <jakub@redhat.com>