[Bug tree-optimization/115629] Inefficient if-convert of masked conditionals

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115629

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:629257bcb81434117f1e9c68479032563176dc0c

commit r15-1662-g629257bcb81434117f1e9c68479032563176dc0c
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Jun 25 14:04:31 2024 +0200

    tree-optimization/115629 - missed tail merging

    The following fixes a missed tail-merging observed for the testcase
    in PR115629.  The issue is that when deps_ok_for_redirect doesn't
    compute both would be valid prevailing blocks it rejects the merge.
    The following instead makes sure to record the working block as
    prevailing.  Also stmt comparison fails for indirect references
    and is not handling memory references thoroughly, failing to unify
    array indices and pointers indirected.  The following attempts to
    fix this.

            PR tree-optimization/115629
            * tree-ssa-tail-merge.cc (gimple_equal_p): Handle
            memory references better.
            (deps_ok_for_redirect): Handle the case not both blocks
            are considered a valid prevailing block.

            * gcc.dg/tree-ssa/tail-merge-1.c: New testcase.