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Re: [PATCH RFC] Imporve 64bit memset performance for Haswell CPU with AVX2 instruction
- From: Ling Ma <ling dot ma dot program at gmail dot com>
- To: libc-alpha at sourceware dot org
- Cc: rth at twiddle dot net, aj at suse dot com, neleai at seznam dot cz, liubov dot dmitrieva at gmail dot com, hjl dot tools at gmail dot com, Ling Ma <ling dot ml at alibaba-inc dot com>
- Date: Wed, 9 Apr 2014 10:51:37 +0800
- Subject: Re: [PATCH RFC] Imporve 64bit memset performance for Haswell CPU with AVX2 instruction
- Authentication-results: sourceware.org; auth=none
- References: <1396850238-29041-1-git-send-email-ling dot ma at alipay dot com>
Any comments about memcpy/memset/avx detection patches?
Thanks
Ling
2014-04-07 13:57 GMT+08:00, ling.ma.program@gmail.com
<ling.ma.program@gmail.com>:
> From: Ling Ma <ling.ml@alibaba-inc.com>
>
> In this patch we take advantage of HSW memory bandwidth, manage to
> reduce miss branch prediction by avoid using branch instructions and
> force destination to be aligned with avx instruction.
>
> The CPU2006 403.gcc benchmark also indicate this patch improves performance
> from 22.9% to 59% compared with original memset implemented by sse2.
>
> memset-AVX memset-SSE2 AVX vs SSE2
> gcc.166.i 1877958334 2495113045 1.328630673
> gcc.200.i 3507448572 4869401205 1.388302952
> gcc.cp-decl.i 1742510758 2282801367 1.310064432
> gcc.c-typeck.i 9546331594 12158804366 1.273662479
> gcc.expr2.i 5067111165 6470777800 1.277015165
> gcc.expr.i 3434703577 4420252661 1.286938614
> gcc.g23.i 5141096267 6318410858 1.22900069
> gcc.s04.i 8652255048 10923077090 1.262454358
> gcc.scilab.i 1209694573 1925173588 1.591454265
>
> ---
> We fixed code and re-test all cases, including sse2 and avx2.
>
> ChangeLog | 9 ++
> sysdeps/x86_64/multiarch/Makefile | 4 +-
> sysdeps/x86_64/multiarch/memset-avx2.S | 192
> +++++++++++++++++++++++++++++++++
> sysdeps/x86_64/multiarch/memset.S | 59 ++++++++++
> sysdeps/x86_64/multiarch/memset_chk.S | 44 ++++++++
> 5 files changed, 307 insertions(+), 1 deletion(-)
> create mode 100644 sysdeps/x86_64/multiarch/memset-avx2.S
> create mode 100644 sysdeps/x86_64/multiarch/memset.S
> create mode 100644 sysdeps/x86_64/multiarch/memset_chk.S
>
> diff --git a/ChangeLog b/ChangeLog
> index ab23a3a..851fe9e 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,12 @@
> +2014-04-04 Ling Ma <ling.ml@alibaba-inc.com>
> +
> + * sysdeps/x86_64/multiarch/Makefile: Add memset-avx2
> + * sysdeps/x86_64/multiarch/memset-avx2.S: New file for AVX2 memset
> + * sysdeps/x86_64/multiarch/memset.S: New file for multiple memset
> + versions
> + * sysdeps/x86_64/multiarch/memset_chk.S: New file for multiple memset_chk
> + versions
> +
> 2014-04-04 Sihai Yao <sihai.ysh@alibaba-inc.com>
>
> * sysdeps/x86_64/multiarch/ifunc-defines.sym: Add COMMON_CPU_INDEX_7 and
> diff --git a/sysdeps/x86_64/multiarch/Makefile
> b/sysdeps/x86_64/multiarch/Makefile
> index 57a3c13..42df96f 100644
> --- a/sysdeps/x86_64/multiarch/Makefile
> +++ b/sysdeps/x86_64/multiarch/Makefile
> @@ -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
> diff --git a/sysdeps/x86_64/multiarch/memset-avx2.S
> b/sysdeps/x86_64/multiarch/memset-avx2.S
> new file mode 100644
> index 0000000..5d4a487
> --- /dev/null
> +++ b/sysdeps/x86_64/multiarch/memset-avx2.S
> @@ -0,0 +1,192 @@
> +/* memset with AVX2
> + Copyright (C) 2014 Free Software Foundation, Inc.
> + Contributed by Alibaba Group.
> + 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 ALIGN
> +# define ALIGN(n) .p2align n
> +#endif
> +#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), %r8
> + vpshufb %xmm0, %xmm1, %xmm0
> + mov %rdi, %rax
> + cmp $256, %rdx
> + jae L(256bytesormore)
> + vmovd %xmm0, %rcx
> + cmp $128, %rdx
> + jb L(less_128bytes)
> + vmovups %xmm0, (%rdi)
> + vmovups %xmm0, 0x10(%rdi)
> + vmovups %xmm0, 0x20(%rdi)
> + vmovups %xmm0, 0x30(%rdi)
> + vmovups %xmm0, 0x40(%rdi)
> + vmovups %xmm0, 0x50(%rdi)
> + vmovups %xmm0, 0x60(%rdi)
> + vmovups %xmm0, 0x70(%rdi)
> + vmovups %xmm0, -0x80(%r8)
> + vmovups %xmm0, -0x70(%r8)
> + vmovups %xmm0, -0x60(%r8)
> + vmovups %xmm0, -0x50(%r8)
> + vmovups %xmm0, -0x40(%r8)
> + vmovups %xmm0, -0x30(%r8)
> + vmovups %xmm0, -0x20(%r8)
> + vmovups %xmm0, -0x10(%r8)
> + ret
> + ALIGN(4)
> +L(less_128bytes):
> + cmp $64, %edx
> + jb L(less_64bytes)
> + vmovups %xmm0, (%rdi)
> + vmovups %xmm0, 0x10(%rdi)
> + vmovups %xmm0, 0x20(%rdi)
> + vmovups %xmm0, 0x30(%rdi)
> + vmovups %xmm0, -0x40(%r8)
> + vmovups %xmm0, -0x30(%r8)
> + vmovups %xmm0, -0x20(%r8)
> + vmovups %xmm0, -0x10(%r8)
> + ret
> + ALIGN(4)
> +L(less_64bytes):
> + cmp $32, %edx
> + jb L(less_32bytes)
> + vmovups %xmm0, (%rdi)
> + vmovups %xmm0, 0x10(%rdi)
> + vmovups %xmm0, -0x20(%r8)
> + vmovups %xmm0, -0x10(%r8)
> + ret
> + ALIGN(4)
> +L(less_32bytes):
> + cmp $16, %edx
> + jb L(less_16bytes)
> + vmovups %xmm0, (%rdi)
> + vmovups %xmm0, -0x10(%r8)
> + ret
> + ALIGN(4)
> +L(less_16bytes):
> + cmp $8, %edx
> + jb L(less_8bytes)
> + mov %rcx, (%rdi)
> + mov %rcx, -0x08(%r8)
> + ret
> + ALIGN(4)
> +L(less_8bytes):
> + cmp $4, %edx
> + jb L(less_4bytes)
> + mov %ecx, (%rdi)
> + mov %ecx, -0x04(%r8)
> + ALIGN(4)
> +L(less_4bytes):
> + cmp $2, %edx
> + jb L(less_2bytes)
> + mov %cx, (%rdi)
> + mov %cx, -0x02(%r8)
> + ret
> + ALIGN(4)
> +L(less_2bytes):
> + cmp $1, %edx
> + jb L(less_1bytes)
> + mov %cl, (%rdi)
> +L(less_1bytes):
> + ret
> +
> + ALIGN(4)
> +L(256bytesormore):
> + vinserti128 $1, %xmm0, %ymm0, %ymm0
> + vmovups %ymm0, (%rdi)
> + mov %rdi, %r9
> + and $-0x20, %rdi
> + add $32, %rdi
> + sub %rdi, %r9
> + add %r9, %rdx
> + cmp $4096, %rdx
> + ja L(gobble_data)
> +
> + sub $0x80, %rdx
> +L(gobble_128_loop):
> + vmovaps %ymm0, (%rdi)
> + vmovaps %ymm0, 0x20(%rdi)
> + vmovaps %ymm0, 0x40(%rdi)
> + vmovaps %ymm0, 0x60(%rdi)
> + lea 0x80(%rdi), %rdi
> + sub $0x80, %rdx
> + jae L(gobble_128_loop)
> + vmovups %ymm0, -0x80(%r8)
> + vmovups %ymm0, -0x60(%r8)
> + vmovups %ymm0, -0x40(%r8)
> + vmovups %ymm0, -0x20(%r8)
> + vzeroupper
> + ret
> +
> + ALIGN(4)
> +L(gobble_data):
> +#ifdef SHARED_CACHE_SIZE_HALF
> + mov $SHARED_CACHE_SIZE_HALF, %r9
> +#else
> + mov __x86_shared_cache_size_half(%rip), %r9
> +#endif
> + shl $4, %r9
> + cmp %r9, %rdx
> + ja L(gobble_big_data)
> + mov %rax, %r9
> + mov %esi, %eax
> + mov %rdx, %rcx
> + rep stosb
> + mov %r9, %rax
> + vzeroupper
> + ret
> +
> + ALIGN(4)
> +L(gobble_big_data):
> + sub $0x80, %rdx
> +L(gobble_big_data_loop):
> + vmovntdq %ymm0, (%rdi)
> + vmovntdq %ymm0, 0x20(%rdi)
> + vmovntdq %ymm0, 0x40(%rdi)
> + vmovntdq %ymm0, 0x60(%rdi)
> + lea 0x80(%rdi), %rdi
> + sub $0x80, %rdx
> + jae L(gobble_big_data_loop)
> + vmovups %ymm0, -0x80(%r8)
> + vmovups %ymm0, -0x60(%r8)
> + vmovups %ymm0, -0x40(%r8)
> + vmovups %ymm0, -0x20(%r8)
> + vzeroupper
> + sfence
> + ret
> +
> +END (MEMSET)
> +#endif
> diff --git a/sysdeps/x86_64/multiarch/memset.S
> b/sysdeps/x86_64/multiarch/memset.S
> new file mode 100644
> index 0000000..df903af
> --- /dev/null
> +++ b/sysdeps/x86_64/multiarch/memset.S
> @@ -0,0 +1,59 @@
> +/* Multiple versions of memset
> + Copyright (C) 2014 Free Software Foundation, Inc.
> + Contributed by Alibaba Group.
> + 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"
> diff --git a/sysdeps/x86_64/multiarch/memset_chk.S
> b/sysdeps/x86_64/multiarch/memset_chk.S
> new file mode 100644
> index 0000000..f048dac
> --- /dev/null
> +++ b/sysdeps/x86_64/multiarch/memset_chk.S
> @@ -0,0 +1,44 @@
> +/* Multiple versions of memset_chk
> + Copyright (C) 2014 Free Software Foundation, Inc.
> + Contributed by Alibaba Group.
> + 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
> --
> 1.8.1.4
>
>