glibc/sysdeps/x86_64/multiarch/memmove_chk.c
H.J. Lu 5f3d0b78e0 Use AVX unaligned memcpy only if AVX2 is available
memcpy with unaligned 256-bit AVX register loads/stores are slow on older
processorsl like Sandy Bridge.  This patch adds bit_AVX_Fast_Unaligned_Load
and sets it only when AVX2 is available.

	[BZ #17801]
	* sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
	Set the bit_AVX_Fast_Unaligned_Load bit for AVX2.
	* sysdeps/x86_64/multiarch/init-arch.h (bit_AVX_Fast_Unaligned_Load):
	New.
	(index_AVX_Fast_Unaligned_Load): Likewise.
	(HAS_AVX_FAST_UNALIGNED_LOAD): Likewise.
	* sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Check the
	bit_AVX_Fast_Unaligned_Load bit instead of the bit_AVX_Usable bit.
	* sysdeps/x86_64/multiarch/memcpy_chk.S (__memcpy_chk): Likewise.
	* sysdeps/x86_64/multiarch/mempcpy.S (__mempcpy): Likewise.
	* sysdeps/x86_64/multiarch/mempcpy_chk.S (__mempcpy_chk): Likewise.
	* sysdeps/x86_64/multiarch/memmove.c (__libc_memmove): Replace
	HAS_AVX with HAS_AVX_FAST_UNALIGNED_LOAD.
	* sysdeps/x86_64/multiarch/memmove_chk.c (__memmove_chk): Likewise.
2015-01-30 15:37:58 -08:00

38 lines
1.5 KiB
C

/* Multiple versions of __memmove_chk.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2010-2015 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 <string.h>
#include "init-arch.h"
#define MEMMOVE_CHK __memmove_chk_sse2
extern __typeof (__memmove_chk) __memmove_chk_sse2 attribute_hidden;
extern __typeof (__memmove_chk) __memmove_chk_ssse3 attribute_hidden;
extern __typeof (__memmove_chk) __memmove_chk_ssse3_back attribute_hidden;
extern __typeof (__memmove_chk) __memmove_chk_avx_unaligned attribute_hidden;
#include "debug/memmove_chk.c"
libc_ifunc (__memmove_chk,
HAS_AVX_FAST_UNALIGNED_LOAD ? __memmove_chk_avx_unaligned :
(HAS_SSSE3
? (HAS_FAST_COPY_BACKWARD
? __memmove_chk_ssse3_back : __memmove_chk_ssse3)
: __memmove_chk_sse2));