[Bug tree-optimization/102139] [11 Regression] -O3 miscompile due to slp-vectorize on strict align target

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102139

--- Comment #11 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:7f04f47d8d414c399ce7b5c8158fadc437469755

commit r11-9224-g7f04f47d8d414c399ce7b5c8158fadc437469755
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Aug 31 10:28:40 2021 +0200

    tree-optimization/102139 - fix SLP DR base alignment

    When doing whole-function SLP we have to make sure the recorded
    base alignments we compute as the maximum alignment seen for a
    base anywhere in the function is actually valid at the point
    we want to make use of it.

    To make this work we now record the stmt the alignment was derived
    from in addition to the DRs innermost behavior and we use a
    dominance check to verify the recorded info is valid when doing
    BB vectorization.  For this to work for groups inside a BB that are
    separate by a call that might not return we now store the DR
    analysis group-id permanently and use that for an additional check
    when the DRs are in the same BB.

    2021-08-31  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/102139
            * tree-vectorizer.h (vec_base_alignments): Adjust hash-map
            type to record a std::pair of the stmt-info and the innermost
            loop behavior.
            (dr_vec_info::group): New member.
            * tree-vect-data-refs.c (vect_record_base_alignment): Adjust.
            (vect_compute_data_ref_alignment): Verify the recorded
            base alignment can be used.
            (data_ref_pair): Remove.
            (dr_group_sort_cmp): Adjust.
            (vect_analyze_data_ref_accesses): Store the group-ID in the
            dr_vec_info and operate on a vector of dr_vec_infos.

            * gcc.dg/torture/pr102139.c: New testcase.

    (cherry picked from commit 153766ec8351d55cfe8bd6d69bdfc0c2cef71e56)