[Bug target/114514] v16qi >> 7 can be optimized with vpcmpgtb

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114514

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by hongtao Liu <liuho...@gcc.gnu.org>:

https://gcc.gnu.org/g:0cc0956b3bb8bcbc9196075b9073a227d799e042

commit r15-529-g0cc0956b3bb8bcbc9196075b9073a227d799e042
Author: liuhongt <hongtao....@intel.com>
Date:   Tue May 14 18:39:54 2024 +0800

    Optimize ashift >> 7 to vpcmpgtb for vector int8.

    Since there is no corresponding instruction, the shift operation for
    vector int8 is implemented using the instructions for vector int16,
    but for some special shift counts, it can be transformed into vpcmpgtb.

    gcc/ChangeLog:

            PR target/114514
            * config/i386/i386-expand.cc
            (ix86_expand_vec_shift_qihi_constant): Optimize ashift >> 7 to
            vpcmpgtb.
            (ix86_expand_vecop_qihi_partial): Ditto.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr114514-shift.c: New test.