From 4cb334c4d6249686653137ec273d081371b3672d Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 18 Apr 2017 14:01:45 -0700 Subject: 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. --- ChangeLog | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'ChangeLog') diff --git a/ChangeLog b/ChangeLog index 51ae9c1..677e5e2 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,26 @@ 2017-04-18 H.J. Lu + [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. + +2017-04-18 H.J. Lu + * sysdeps/x86/cpu-features.c (init_cpu_features): Set Prefer_No_VZEROUPPER if AVX512ER is available. * sysdeps/x86/cpu-features.h -- cgit v1.1