[Bug tree-optimization/123539] Signed overflow introduced by vectorizer; reduction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123539

--- 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:47d09318c411911408058de38bebc16a177fa8e1

commit r16-6734-g47d09318c411911408058de38bebc16a177fa8e1
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jan 12 14:10:32 2026 +0100

    tree-optimization/123539 - signed UB in vector reduction

    With previous changes I overlooked one use of vectype.

            PR tree-optimization/123539
            * tree-vect-loop.cc (vect_create_epilog_for_reduction):
            Use the compute vectype to pun down to smaller or element
            size for by-element reductions.