glibc/sysdeps/x86_64/multiarch/memmove.S
H.J. Lu 4cb334c4d6 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.
2017-04-18 14:01:45 -07:00

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ArmAsm

/* Multiple versions of memmove
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2016-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <init-arch.h>
/* Define multiple versions only for the definition in lib and for
DSO. */
#if IS_IN (libc)
.text
ENTRY(__libc_memmove)
.type __libc_memmove, @gnu_indirect_function
LOAD_RTLD_GLOBAL_RO_RDX
lea __memmove_erms(%rip), %RAX_LP
HAS_ARCH_FEATURE (Prefer_ERMS)
jnz 2f
HAS_ARCH_FEATURE (Prefer_No_AVX512)
jnz 1f
HAS_ARCH_FEATURE (AVX512F_Usable)
jz 1f
lea __memmove_avx512_no_vzeroupper(%rip), %RAX_LP
HAS_ARCH_FEATURE (Prefer_No_VZEROUPPER)
jnz 2f
lea __memmove_avx512_unaligned_erms(%rip), %RAX_LP
HAS_CPU_FEATURE (ERMS)
jnz 2f
lea __memmove_avx512_unaligned(%rip), %RAX_LP
ret
1: lea __memmove_avx_unaligned(%rip), %RAX_LP
HAS_ARCH_FEATURE (AVX_Fast_Unaligned_Load)
jz L(Fast_Unaligned_Load)
HAS_CPU_FEATURE (ERMS)
jz 2f
lea __memmove_avx_unaligned_erms(%rip), %RAX_LP
ret
L(Fast_Unaligned_Load):
lea __memmove_sse2_unaligned(%rip), %RAX_LP
HAS_ARCH_FEATURE (Fast_Unaligned_Copy)
jz L(SSSE3)
HAS_CPU_FEATURE (ERMS)
jz 2f
lea __memmove_sse2_unaligned_erms(%rip), %RAX_LP
ret
L(SSSE3):
HAS_CPU_FEATURE (SSSE3)
jz 2f
lea __memmove_ssse3_back(%rip), %RAX_LP
HAS_ARCH_FEATURE (Fast_Copy_Backward)
jnz 2f
lea __memmove_ssse3(%rip), %RAX_LP
2: ret
END(__libc_memmove)
#endif
#if IS_IN (libc)
# define MEMMOVE_SYMBOL(p,s) p##_sse2_##s
# ifdef SHARED
libc_hidden_ver (__memmove_sse2_unaligned, memmove)
libc_hidden_ver (__memcpy_sse2_unaligned, memcpy)
libc_hidden_ver (__mempcpy_sse2_unaligned, mempcpy)
libc_hidden_ver (__mempcpy_sse2_unaligned, __mempcpy)
# undef libc_hidden_builtin_def
/* It doesn't make sense to send libc-internal memmove calls through a PLT.
The speedup we get from using SSE2 instructions is likely eaten away
by the indirect call in the PLT. */
# define libc_hidden_builtin_def
# endif
strong_alias (__libc_memmove, memmove)
#endif
#if !defined SHARED || !IS_IN (libc)
weak_alias (__mempcpy, mempcpy)
#endif
#include "../memmove.S"
#if defined SHARED && IS_IN (libc)
# include <shlib-compat.h>
# if SHLIB_COMPAT (libc, GLIBC_2_2_5, GLIBC_2_14)
/* Use __memmove_sse2_unaligned to support overlapping addresses. */
compat_symbol (libc, __memmove_sse2_unaligned, memcpy, GLIBC_2_2_5);
# endif
#endif