[Bug target/114427] [x86] vec_pack_truncv8si/v4si can be optimized with pblendw instead of pand for AVX2 target

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114427

--- Comment #1 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:0ebaffccb294d90184ad78367de66b6307de3ac0

commit r15-717-g0ebaffccb294d90184ad78367de66b6307de3ac0
Author: liuhongt <hongtao....@intel.com>
Date:   Fri Mar 22 14:40:00 2024 +0800

    Use pblendw instead of pand to clear upper 16 bits.

    For vec_pack_truncv8si/v4si w/o AVX512,
    (const_vector:v4si (const_int 0xffff) x4) is used as mask to clear
    upper 16 bits, but vpblendw with zero_vector can also be used, and
    zero vector is cheaper than (const_vector:v4si (const_int 0xffff) x4).

    gcc/ChangeLog:
            PR target/114427
            * config/i386/i386-expand.cc (expand_vec_perm_even_odd_pack):
            Use pblendw instead of pand to clear upper bits.

    gcc/testsuite/ChangeLog:
            * gcc.target/i386/pr114427.c: New test.