[Bug tree-optimization/120944] [12/13/14/15 Regression] Incorrect optimization with accessing a volatile structure member

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120944

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-15 branch has been updated by Richard Biener
<rgue...@gcc.gnu.org>:

https://gcc.gnu.org/g:2c23368ed910a911e72af5decfc39bef11a9efac

commit r15-9939-g2c23368ed910a911e72af5decfc39bef11a9efac
Author: Richard Biener <rguent...@suse.de>
Date:   Fri Jul 4 09:08:19 2025 +0200

    tree-optimization/120944 - bogus VN with volatile copies

    The following avoids translating expressions through volatile
    copies.

            PR tree-optimization/120944
            * tree-ssa-sccvn.cc (vn_reference_lookup_3): Gate optimizations
            invalid when volatile is involved.

            * gcc.dg/torture/pr120944.c: New testcase.

    (cherry picked from commit 6ed1e2ae1a742d859c2dd74c9e7cebdd3618e8b1)