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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.
76 lines
2.3 KiB
ArmAsm
76 lines
2.3 KiB
ArmAsm
/* Multiple versions of memcpy
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2010-2017 Free Software Foundation, Inc.
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Contributed by Intel Corporation.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include <init-arch.h>
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/* Define multiple versions only for the definition in lib and for
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DSO. In static binaries we need memcpy before the initialization
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happened. */
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#if defined SHARED && IS_IN (libc)
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.text
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ENTRY(__new_memcpy)
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.type __new_memcpy, @gnu_indirect_function
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LOAD_RTLD_GLOBAL_RO_RDX
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lea __memcpy_erms(%rip), %RAX_LP
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HAS_ARCH_FEATURE (Prefer_ERMS)
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jnz 2f
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HAS_ARCH_FEATURE (Prefer_No_AVX512)
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jnz 1f
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HAS_ARCH_FEATURE (AVX512F_Usable)
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jz 1f
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lea __memcpy_avx512_no_vzeroupper(%rip), %RAX_LP
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HAS_ARCH_FEATURE (Prefer_No_VZEROUPPER)
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jnz 2f
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lea __memcpy_avx512_unaligned_erms(%rip), %RAX_LP
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HAS_CPU_FEATURE (ERMS)
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jnz 2f
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lea __memcpy_avx512_unaligned(%rip), %RAX_LP
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ret
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1: lea __memcpy_avx_unaligned(%rip), %RAX_LP
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HAS_ARCH_FEATURE (AVX_Fast_Unaligned_Load)
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jz L(Fast_Unaligned_Load)
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HAS_CPU_FEATURE (ERMS)
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jz 2f
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lea __memcpy_avx_unaligned_erms(%rip), %RAX_LP
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ret
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L(Fast_Unaligned_Load):
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lea __memcpy_sse2_unaligned(%rip), %RAX_LP
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HAS_ARCH_FEATURE (Fast_Unaligned_Copy)
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jz L(SSSE3)
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HAS_CPU_FEATURE (ERMS)
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jz 2f
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lea __memcpy_sse2_unaligned_erms(%rip), %RAX_LP
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ret
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L(SSSE3):
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HAS_CPU_FEATURE (SSSE3)
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jz 2f
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lea __memcpy_ssse3_back(%rip), %RAX_LP
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HAS_ARCH_FEATURE (Fast_Copy_Backward)
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jnz 2f
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lea __memcpy_ssse3(%rip), %RAX_LP
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2: ret
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END(__new_memcpy)
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# undef memcpy
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# include <shlib-compat.h>
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versioned_symbol (libc, __new_memcpy, memcpy, GLIBC_2_14);
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#endif
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