[Bug tree-optimization/103237] [9 Regression] wrong code with -ftree-vectorize at -O1 on x86_64-linux-gnu starting with r7-1219-gb28ead45fe630b9e

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103237

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:68c80396906ab10051a69a2181e114c61dd4ee8a

commit r9-9954-g68c80396906ab10051a69a2181e114c61dd4ee8a
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Nov 15 11:37:56 2021 +0100

    tree-optimization/103237 - avoid vectorizing unhandled double reductions

    Double reductions which have multiple LC PHIs in the inner loop
    are not handled correctly during transformation since those PHIs
    are not properly classified as reduction.  The following disables
    vectorizing them.

    2021-11-15  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/103237
            * tree-vect-loop.c (vect_is_simple_reduction): Fail for
            double reductions with multiple inner loop LC PHI nodes.

            * gcc.dg/torture/pr103237.c: New testcase.

    (cherry picked from commit 220bd61874cf114667b44f9ded76ed0639eb278b)