[Bug tree-optimization/100253] [10/11 Regression] wrong code with -O2 -fno-tree-bit-ccp -ftree-slp-vectorize (unaligned movdqa)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100253

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

https://gcc.gnu.org/g:c980fbf5505dc2f50136d501b67dc3fbf4b08b0d

commit r11-8353-gc980fbf5505dc2f50136d501b67dc3fbf4b08b0d
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Apr 29 11:52:08 2021 +0200

    tree-optimization/100253 - fix bogus aligned vectorized loads/stores

    At some point DR_MISALIGNMENT was supposed to be -1 when the
    access was not element aligned.  That's obviously not true at this
    point so this adjusts both store and load vectorizing to no longer
    assume this which in turn allows simplifying the code.

    2021-04-29  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/100253
            * tree-vect-stmts.c (vectorizable_load): Do not assume
            element alignment when DR_MISALIGNMENT is -1.
            (vectorizable_store): Likewise.

            * g++.dg/pr100253.C: New testcase.

    (cherry picked from commit af4ccaa7515b8e72449448c509916575831e6292)