Add x86_64 memset optimized for AVX2

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 & avx2 instruction.

The CPU2006 403.gcc benchmark indicates this patch improves performance
from 26% to 59%.

	* sysdeps/x86_64/multiarch/Makefile: Add memset-avx2.
	* sysdeps/x86_64/multiarch/memset-avx2.S: New file.
	* sysdeps/x86_64/multiarch/memset.S: Likewise.
	* sysdeps/x86_64/multiarch/memset_chk.S: Likewise.
	* sysdeps/x86_64/multiarch/rtld-memset.S: Likewise.
This commit is contained in:
Ling Ma 2014-06-19 13:00:56 -07:00 committed by H.J. Lu
parent 4d43ef1e74
commit 5c74e47cd6
6 changed files with 284 additions and 1 deletions

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@ -1,3 +1,12 @@
2014-06-19 Ling Ma <ling.ml@alibaba-inc.com>
H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/multiarch/Makefile: Add memset-avx2.
* sysdeps/x86_64/multiarch/memset-avx2.S: New file.
* sysdeps/x86_64/multiarch/memset.S: Likewise.
* sysdeps/x86_64/multiarch/memset_chk.S: Likewise.
* sysdeps/x86_64/multiarch/rtld-memset.S: Likewise.
2014-06-19 Andreas Schwab <schwab@linux-m68k.org>
[BZ #17069]

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@ -17,7 +17,9 @@ sysdep_routines += strncat-c stpncpy-c strncpy-c strcmp-ssse3 \
strcpy-sse2-unaligned strncpy-sse2-unaligned \
stpcpy-sse2-unaligned stpncpy-sse2-unaligned \
strcat-sse2-unaligned strncat-sse2-unaligned \
strchr-sse2-no-bsf memcmp-ssse3 strstr-sse2-unaligned
strchr-sse2-no-bsf memcmp-ssse3 strstr-sse2-unaligned \
memset-avx2
ifeq (yes,$(config-cflags-sse4))
sysdep_routines += strcspn-c strpbrk-c strspn-c varshift
CFLAGS-varshift.c += -msse4

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@ -0,0 +1,168 @@
/* memset with AVX2
Copyright (C) 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 <sysdep.h>
#if !defined NOT_IN_libc
#include "asm-syntax.h"
#ifndef MEMSET
# define MEMSET __memset_avx2
# define MEMSET_CHK __memset_chk_avx2
#endif
.section .text.avx2,"ax",@progbits
#if defined PIC
ENTRY (MEMSET_CHK)
cmpq %rdx, %rcx
jb HIDDEN_JUMPTARGET (__chk_fail)
END (MEMSET_CHK)
#endif
ENTRY (MEMSET)
vpxor %xmm0, %xmm0, %xmm0
vmovd %esi, %xmm1
lea (%rdi, %rdx), %rsi
mov %rdi, %rax
vpshufb %xmm0, %xmm1, %xmm0
cmp $16, %rdx
jb L(less_16bytes)
cmp $256, %rdx
jae L(256bytesormore)
cmp $128, %dl
jb L(less_128bytes)
vmovdqu %xmm0, (%rdi)
vmovdqu %xmm0, 0x10(%rdi)
vmovdqu %xmm0, 0x20(%rdi)
vmovdqu %xmm0, 0x30(%rdi)
vmovdqu %xmm0, 0x40(%rdi)
vmovdqu %xmm0, 0x50(%rdi)
vmovdqu %xmm0, 0x60(%rdi)
vmovdqu %xmm0, 0x70(%rdi)
vmovdqu %xmm0, -0x80(%rsi)
vmovdqu %xmm0, -0x70(%rsi)
vmovdqu %xmm0, -0x60(%rsi)
vmovdqu %xmm0, -0x50(%rsi)
vmovdqu %xmm0, -0x40(%rsi)
vmovdqu %xmm0, -0x30(%rsi)
vmovdqu %xmm0, -0x20(%rsi)
vmovdqu %xmm0, -0x10(%rsi)
ret
.p2align 4
L(less_128bytes):
cmp $64, %dl
jb L(less_64bytes)
vmovdqu %xmm0, (%rdi)
vmovdqu %xmm0, 0x10(%rdi)
vmovdqu %xmm0, 0x20(%rdi)
vmovdqu %xmm0, 0x30(%rdi)
vmovdqu %xmm0, -0x40(%rsi)
vmovdqu %xmm0, -0x30(%rsi)
vmovdqu %xmm0, -0x20(%rsi)
vmovdqu %xmm0, -0x10(%rsi)
ret
.p2align 4
L(less_64bytes):
cmp $32, %dl
jb L(less_32bytes)
vmovdqu %xmm0, (%rdi)
vmovdqu %xmm0, 0x10(%rdi)
vmovdqu %xmm0, -0x20(%rsi)
vmovdqu %xmm0, -0x10(%rsi)
ret
.p2align 4
L(less_32bytes):
vmovdqu %xmm0, (%rdi)
vmovdqu %xmm0, -0x10(%rsi)
ret
.p2align 4
L(less_16bytes):
cmp $8, %dl
jb L(less_8bytes)
vmovq %xmm0, (%rdi)
vmovq %xmm0, -0x08(%rsi)
ret
.p2align 4
L(less_8bytes):
vmovd %xmm0, %ecx
cmp $4, %dl
jb L(less_4bytes)
mov %ecx, (%rdi)
mov %ecx, -0x04(%rsi)
ret
.p2align 4
L(less_4bytes):
cmp $2, %dl
jb L(less_2bytes)
mov %cx, (%rdi)
mov %cx, -0x02(%rsi)
ret
.p2align 4
L(less_2bytes):
cmp $1, %dl
jb L(less_1bytes)
mov %cl, (%rdi)
L(less_1bytes):
ret
.p2align 4
L(256bytesormore):
vinserti128 $1, %xmm0, %ymm0, %ymm0
and $-0x20, %rdi
add $0x20, %rdi
vmovdqu %ymm0, (%rax)
sub %rdi, %rax
lea -0x80(%rax, %rdx), %rcx
cmp $4096, %rcx
ja L(gobble_data)
L(gobble_128_loop):
vmovdqa %ymm0, (%rdi)
vmovdqa %ymm0, 0x20(%rdi)
vmovdqa %ymm0, 0x40(%rdi)
vmovdqa %ymm0, 0x60(%rdi)
sub $-0x80, %rdi
add $-0x80, %ecx
jb L(gobble_128_loop)
mov %rsi, %rax
vmovdqu %ymm0, -0x80(%rsi)
vmovdqu %ymm0, -0x60(%rsi)
vmovdqu %ymm0, -0x40(%rsi)
vmovdqu %ymm0, -0x20(%rsi)
sub %rdx, %rax
vzeroupper
ret
.p2align 4
L(gobble_data):
sub $-0x80, %rcx
vmovd %xmm0, %eax
rep stosb
mov %rsi, %rax
sub %rdx, %rax
vzeroupper
ret
END (MEMSET)
#endif

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@ -0,0 +1,59 @@
/* Multiple versions of memset
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 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 <sysdep.h>
#include <shlib-compat.h>
#include <init-arch.h>
/* Define multiple versions only for the definition in lib. */
#ifndef NOT_IN_libc
ENTRY(memset)
.type memset, @gnu_indirect_function
cmpl $0, __cpu_features+KIND_OFFSET(%rip)
jne 1f
call __init_cpu_features
1: leaq __memset_sse2(%rip), %rax
testl $bit_AVX2_Usable, __cpu_features+FEATURE_OFFSET+index_AVX2_Usable(%rip)
jz 2f
leaq __memset_avx2(%rip), %rax
2: ret
END(memset)
#endif
#if !defined NOT_IN_libc
# undef memset
# define memset __memset_sse2
# undef __memset_chk
# define __memset_chk __memset_chk_sse2
# ifdef SHARED
# undef libc_hidden_builtin_def
/* It doesn't make sense to send libc-internal memset calls through a PLT.
The speedup we get from using GPR instruction is likely eaten away
by the indirect call in the PLT. */
# define libc_hidden_builtin_def(name) \
.globl __GI_memset; __GI_memset = __memset_sse2
# endif
# undef strong_alias
# define strong_alias(original, alias)
#endif
#include "../memset.S"

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@ -0,0 +1,44 @@
/* Multiple versions of memset_chk
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 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 <sysdep.h>
#include <init-arch.h>
/* Define multiple versions only for the definition in lib. */
#ifndef NOT_IN_libc
# ifdef SHARED
ENTRY(__memset_chk)
.type __memset_chk, @gnu_indirect_function
cmpl $0, __cpu_features+KIND_OFFSET(%rip)
jne 1f
call __init_cpu_features
1: leaq __memset_chk_sse2(%rip), %rax
testl $bit_AVX2_Usable, __cpu_features+FEATURE_OFFSET+index_AVX2_Usable(%rip)
jz 2f
leaq __memset_chk_avx2(%rip), %rax
2: ret
END(__memset_chk)
strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
.section .gnu.warning.__memset_zero_constant_len_parameter
.string "memset used with constant zero length parameter; this could be due to transposed parameters"
# else
# include "../memset_chk.S"
# endif
#endif

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@ -0,0 +1 @@
#include "../rtld-memset.S"