mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
2d48b41c8f
We add new memcpy version that uses unaligned loads which are fast on modern processors. This allows second improvement which is avoiding computed jump which is relatively expensive operation. Tests available here: http://kam.mff.cuni.cz/~ondra/memcpy_profile_result27_04_13.tar.bz2
80 lines
2.5 KiB
ArmAsm
80 lines
2.5 KiB
ArmAsm
/* Multiple versions of memcpy
|
|
All versions must be listed in ifunc-impl-list.c.
|
|
Copyright (C) 2010-2013 Free Software Foundation, Inc.
|
|
Contributed by Intel Corporation.
|
|
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 <shlib-compat.h>
|
|
#include <init-arch.h>
|
|
|
|
/* Define multiple versions only for the definition in lib and for
|
|
DSO. In static binaries we need memcpy before the initialization
|
|
happened. */
|
|
#if defined SHARED && !defined NOT_IN_libc
|
|
.text
|
|
ENTRY(__new_memcpy)
|
|
.type __new_memcpy, @gnu_indirect_function
|
|
cmpl $0, KIND_OFFSET+__cpu_features(%rip)
|
|
jne 1f
|
|
call __init_cpu_features
|
|
1: leaq __memcpy_sse2(%rip), %rax
|
|
testl $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip)
|
|
jnz 2f
|
|
leaq __memcpy_sse2_unaligned(%rip), %rax
|
|
ret
|
|
2: testl $bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip)
|
|
jz 3f
|
|
leaq __memcpy_ssse3(%rip), %rax
|
|
3: ret
|
|
END(__new_memcpy)
|
|
|
|
# undef ENTRY
|
|
# define ENTRY(name) \
|
|
.type __memcpy_sse2, @function; \
|
|
.globl __memcpy_sse2; \
|
|
.hidden __memcpy_sse2; \
|
|
.p2align 4; \
|
|
__memcpy_sse2: cfi_startproc; \
|
|
CALL_MCOUNT
|
|
# undef END
|
|
# define END(name) \
|
|
cfi_endproc; .size __memcpy_sse2, .-__memcpy_sse2
|
|
|
|
# undef ENTRY_CHK
|
|
# define ENTRY_CHK(name) \
|
|
.type __memcpy_chk_sse2, @function; \
|
|
.globl __memcpy_chk_sse2; \
|
|
.p2align 4; \
|
|
__memcpy_chk_sse2: cfi_startproc; \
|
|
CALL_MCOUNT
|
|
# undef END_CHK
|
|
# define END_CHK(name) \
|
|
cfi_endproc; .size __memcpy_chk_sse2, .-__memcpy_chk_sse2
|
|
|
|
# undef libc_hidden_builtin_def
|
|
/* It doesn't make sense to send libc-internal memcpy calls through a PLT.
|
|
The speedup we get from using SSSE3 instruction is likely eaten away
|
|
by the indirect call in the PLT. */
|
|
# define libc_hidden_builtin_def(name) \
|
|
.globl __GI_memcpy; __GI_memcpy = __memcpy_sse2
|
|
|
|
versioned_symbol (libc, __new_memcpy, memcpy, GLIBC_2_14);
|
|
#endif
|
|
|
|
#include "../memcpy.S"
|