glibc/sysdeps/x86_64/multiarch/memmove_chk.c
Ling Ma 05f3633da4 Improve 64bit memcpy performance for Haswell CPU with AVX instruction
In this patch we take advantage of HSW memory bandwidth, manage to
reduce miss branch prediction by avoiding using branch instructions and
force destination to be aligned with avx instruction.

The CPU2006 403.gcc benchmark indicates this patch improves performance
from 2% to 10%.
2014-07-30 08:02:35 -07:00

38 lines
1.5 KiB
C

/* Multiple versions of __memmove_chk.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2010-2014 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 ? __memmove_chk_avx_unaligned :
(HAS_SSSE3
? (HAS_FAST_COPY_BACKWARD
? __memmove_chk_ssse3_back : __memmove_chk_ssse3)
: __memmove_chk_sse2));