[Bug tree-optimization/100089] [11/12 Regression] 30% performance regression for denbench/mp2decoddata2 with -O3

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100089

--- Comment #12 from CVS 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:199cd0e0f8744ca1e61a95987b2d020a592a46d9

commit r12-6795-g199cd0e0f8744ca1e61a95987b2d020a592a46d9
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jan 21 13:29:06 2022 +0100

    tree-optimization/100089 - BB vectorization of if-converted loop bodies

    The PR complains that when we only partially BB vectorize an
    if-converted loop body that this can leave unvectorized code
    unconditionally executed and thus effectively slow down code.
    For -O2 we already mitigated the issue by not doing BB vectorization
    when not all if-converted stmts were covered but the issue is
    present with -O3 as well.  Thus the following simply extends the
    fix to cover all but the unlimited cost models.  It is after all
    very likely that we vectorize some stmts, if only a single
    paired store.

    2022-01-21  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/100089
            * tree-vect-slp.cc (vect_slp_region): Reject BB vectorization
            of if-converted loops with unvectorized COND_EXPRs for
            all but the unlimited cost models.