[Bug tree-optimization/97081] [8 Regression] wrong code for rotate vectorization (x86 target)

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97081

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Richard Biener
<rgue...@gcc.gnu.org>:

https://gcc.gnu.org/g:16e2f38167eb90a4dc977b806dcc0dc9011cc456

commit r8-10801-g16e2f38167eb90a4dc977b806dcc0dc9011cc456
Author: Richard Biener <rguent...@suse.de>
Date:   Fri Sep 18 13:36:24 2020 +0200

    tree-optimization/97081 - fix wrong-code with vectorized shift

    This corrects the mask for creation of x << s | x >> (-x & mask)
    from a rotate x <<r s to use the precision of x.

    2020-09-18  Richard Biener  <rguent...@suse.de>

            PR tree-optimization/97081
            * tree-vect-patterns.c (vect_recog_rotate_pattern): Use the
            precision of the shifted operand to determine the mask.

            * gcc.dg/vect/pr97081.c: New testcase.

    (cherry picked from commit 86b25a1a5e1956c30fe7eaee80ebf719b759d631)