[Bug libc/21396] Use AVX2 memcpy/memset on Skylake server

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https://sourceware.org/bugzilla/show_bug.cgi?id=21396

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https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a29331702f3b58a2f4afb051b219a7e0deb1f487

commit a29331702f3b58a2f4afb051b219a7e0deb1f487
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Apr 28 10:27:22 2017 -0700

    x86: Use AVX2 memcpy/memset on Skylake server [BZ #21396]

    On Skylake server, AVX512 load/store instructions in memcpy/memset may
    lead to lower CPU turbo frequency in certain situations.  Use of AVX2
    in memcpy/memset has been observed to have improved overall performance
    in many workloads due to the higher frequency.

    Since AVX512ER is unique to Xeon Phi, this patch sets Prefer_No_AVX512
    if AVX512ER isn't available so that AVX2 versions of memcpy/memset are
    used on Skylake server.

        [BZ #21396]
        * sysdeps/x86/cpu-features.c (init_cpu_features): Set
        Prefer_No_AVX512 if AVX512ER isn't available.
        * sysdeps/x86/cpu-features.h (bit_arch_Prefer_No_AVX512): New.
        (index_arch_Prefer_No_AVX512): Likewise.
        * sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Don't use
        AVX512 version if Prefer_No_AVX512 is set.
        * sysdeps/x86_64/multiarch/memcpy_chk.S (__memcpy_chk):
        Likewise.
        * sysdeps/x86_64/multiarch/memmove.S (__libc_memmove): Likewise.
        * sysdeps/x86_64/multiarch/memmove_chk.S (__memmove_chk):
        Likewise.
        * sysdeps/x86_64/multiarch/mempcpy.S (__mempcpy): Likewise.
        * sysdeps/x86_64/multiarch/mempcpy_chk.S (__mempcpy_chk):
        Likewise.
        * sysdeps/x86_64/multiarch/memset.S (memset): Likewise.
        * sysdeps/x86_64/multiarch/memset_chk.S (__memset_chk):
        Likewise.

    (cherry picked from commit 4cb334c4d6249686653137ec273d081371b3672d)

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=5f85ab28690a94355a0eaf75206cdf237fe6009d

commit 5f85ab28690a94355a0eaf75206cdf237fe6009d
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Apr 28 10:26:58 2017 -0700

    x86: Set Prefer_No_VZEROUPPER if AVX512ER is available

    AVX512ER won't be implemented in any Xeon processors and will be in
    all Xeon Phi processors.  Don't check CPU model number when setting
    Prefer_No_VZEROUPPER for Xeon Phi.  Instead, set Prefer_No_VZEROUPPER
    if AVX512ER is available.  It works with current and future Xeon Phi
    and non-Xeon Phi processors.

        * sysdeps/x86/cpu-features.c (init_cpu_features): Set
        Prefer_No_VZEROUPPER if AVX512ER is available.
        * sysdeps/x86/cpu-features.h
        (bit_cpu_AVX512PF): New.
        (bit_cpu_AVX512ER): Likewise.
        (bit_cpu_AVX512CD): Likewise.
        (bit_cpu_AVX512BW): Likewise.
        (bit_cpu_AVX512VL): Likewise.
        (index_cpu_AVX512PF): Likewise.
        (index_cpu_AVX512ER): Likewise.
        (index_cpu_AVX512CD): Likewise.
        (index_cpu_AVX512BW): Likewise.
        (index_cpu_AVX512VL): Likewise.
        (reg_AVX512PF): Likewise.
        (reg_AVX512ER): Likewise.
        (reg_AVX512CD): Likewise.
        (reg_AVX512BW): Likewise.
        (reg_AVX512VL): Likewise.

    (cherry picked from commit 1c53cb49de6d82d9469ccbd5aa0c55924502bd8b)

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog                              |   42 ++++++++++++++++++++++++++++++++
 sysdeps/x86/cpu-features.c             |   12 +++++++-
 sysdeps/x86/cpu-features.h             |   18 +++++++++++++
 sysdeps/x86_64/multiarch/memcpy.S      |    2 +
 sysdeps/x86_64/multiarch/memcpy_chk.S  |    2 +
 sysdeps/x86_64/multiarch/memmove.S     |    2 +
 sysdeps/x86_64/multiarch/memmove_chk.S |    2 +
 sysdeps/x86_64/multiarch/mempcpy.S     |    2 +
 sysdeps/x86_64/multiarch/mempcpy_chk.S |    2 +
 sysdeps/x86_64/multiarch/memset.S      |    2 +
 sysdeps/x86_64/multiarch/memset_chk.S  |    2 +
 11 files changed, 86 insertions(+), 2 deletions(-)

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