[Bug tree-optimization/25290] PHI-OPT could be rewritten so that is uses match

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25290

--- Comment #20 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:c4574d23cb07340918793a5a98ae7bb2988b3791

commit r12-1309-gc4574d23cb07340918793a5a98ae7bb2988b3791
Author: Andrew Pinski <apinski@marvell.com>
Date:   Tue Jun 1 06:48:05 2021 +0000

    Improve match_simplify_replacement in phi-opt

    This improves match_simplify_replace in phi-opt to handle the
    case where there is one cheap (non-call) preparation statement in the
    middle basic block similar to xor_replacement and others.
    This allows to remove xor_replacement which it does too.

    OK?  Bootstrapped and tested on x86_64-linux-gnu with no regressions.

    Thanks,
    Andrew Pinski

    Changes since v1:
    v3 - Just minor changes to using gimple_assign_lhs
    instead of gimple_lhs and fixing a comment.
    v2 - change the check on the preparation statement to
    allow only assignments and no calls and only assignments
    that feed into the phi.

    gcc/ChangeLog:

            PR tree-optimization/25290
            * tree-ssa-phiopt.c (xor_replacement): Delete.
            (tree_ssa_phiopt_worker): Delete use of xor_replacement.
            (match_simplify_replacement): Allow one cheap preparation
            statement that can be moved to before the if.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/pr96928-1.c: Fix testcase for now that ~
            happens on the outside of the bit_xor.