[Bug target/95791] Unnecessary vzeroupper when only using zmm16 through zmm31

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95791

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <hjl@gcc.gnu.org>:

https://gcc.gnu.org/g:9302421e71e85b4d3766a534ed9e1c4ae1e7a6ca

commit r11-1585-g9302421e71e85b4d3766a534ed9e1c4ae1e7a6ca
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jun 20 16:02:42 2020 -0700

    x86: Skip EXT_REX_SSE_REG_P for vzeroupper optimization

    Skip EXT_REX_SSE_REG_P for vzeroupper optimization since upper 16 vector
    registers don't trigger SSE <-> AVX transition penalty.

    gcc/

            PR target/95791
            * config/i386/i386.c (ix86_dirflag_mode_needed): Skip
            EXT_REX_SSE_REG_P.

    gcc/testsuite/

            PR target/95791
            * gcc.target/i386/pr95791.c: New test.