[Bug tree-optimization/107107] [10/11/12 Regression] Wrong codegen from TBAA when stores to distinct same-mode types are collapsed?

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107107

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:ff0a274e5c3026b105c7f51126fa51f8178fa42c

commit r12-8838-gff0a274e5c3026b105c7f51126fa51f8178fa42c
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Oct 6 11:20:16 2022 +0200

    tree-optimization/107107 - tail-merging VN wrong-code

    The following fixes an unintended(?) side-effect of the special
    MODIFY_EXPR expression entries we add for tail-merging during VN.
    We shouldn't value-number the virtual operand differently here.

            PR tree-optimization/107107
            * tree-ssa-sccvn.cc (visit_reference_op_store): Do not
            affect value-numbering when doing the tail merging
            MODIFY_EXPR lookup.

            * gcc.dg/pr107107.c: New testcase.

    (cherry picked from commit 85333b9265720fc4e49397301cb16324d2b89aa7)