[Bug tree-optimization/103941] uavgv2qi3_ceil is not used (SLP costing and patterns vs live stmts)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103941

--- Comment #5 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:353434b65ef7972172597d232ae17022d9a57244

commit r12-8195-g353434b65ef7972172597d232ae17022d9a57244
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Apr 13 13:49:45 2022 +0200

    tree-optimization/104010 - fix SLP scalar costing with patterns

    When doing BB vectorization the scalar cost compute is derailed
    by patterns, causing lanes to be considered live and thus not
    costed on the scalar side.  For the testcase in PR104010 this
    prevents vectorization which was done by GCC 11.  PR103941
    shows similar cases of missed optimizations that are fixed by
    this patch.

    2022-04-13  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/104010
            PR tree-optimization/103941
            * tree-vect-slp.cc (vect_bb_slp_scalar_cost): When
            we run into stmts in patterns continue walking those
            for uses outside of the vectorized region instead of
            marking the lane live.

            * gcc.target/i386/pr103941-1.c: New testcase.
            * gcc.target/i386/pr103941-2.c: Likewise.