[Bug tree-optimization/123107] [15/16 Regression] X86-64: ICE at -O2 during RTL pass: expand

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123107

--- Comment #13 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:ae0cdb01b08fb4929ef17c534f86cd9fae78e799

commit r16-6569-gae0cdb01b08fb4929ef17c534f86cd9fae78e799
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Jan 7 13:18:42 2026 +0100

    middle-end/123107 - avoid invalid vector folding

    We fold (v >> CST) == { 0, 0.. } into v < { 0, 0.. } but fail to
    validate that's valid for the target.  The following adds such check,
    making sure to apply after IPA (due to offloading) and only when
    the original form wasn't valid for the target (like before vector
    lowering) or when the new form is.  In particular in this case
    we have an equality compare resulting in a non-vector which we
    can handle, but a similar LT/GT is never handled.

            PR middle-end/123107
            * fold-const.cc (fold_binary_loc): Guard (v >> CST) == { 0, 0.. }
            to v < { 0, 0.. } folding.

            * gcc.dg/torture/pr123107.c: New testcase.