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Re: [PATCH v2 2/2] aarch64: Optimized memcpy and memmove for Kunpeng processor
- From: Yikun Jiang <yikunkero at gmail dot com>
- To: Xuelei Zhang <zhangxuelei4 at huawei dot com>
- Cc: libc-alpha at sourceware dot org, nd at arm dot com, Siddhesh Poyarekar <siddhesh at gotplt dot org>, Wilco dot Dijkstra at arm dot com, jiangyikun at huawei dot com
- Date: Thu, 17 Oct 2019 22:57:17 +0800
- Subject: Re: [PATCH v2 2/2] aarch64: Optimized memcpy and memmove for Kunpeng processor
- References: <20191017131548.10808-1-zhangxuelei4@huawei.com>
> Btw do you have any plans to post other string functions that you can discuss here? If so, would these
> add more ifuncs or improve the generic versions?
> Yes, memcmp, strlen, strnlen, strcpy, memrchr will be included, we will summited the patch and test results as soon as possible.
We have submitted the patches of string functions, see below:
[PATCH] aarch64: Optimized strnlen for Kunpeng processor
https://sourceware.org/ml/libc-alpha/2019-10/msg00528.html
[PATCH] aarch64: Optimized strlen for Kunpeng processor
https://sourceware.org/ml/libc-alpha/2019-10/msg00527.html
[PATCH] aarch64: Optimized implementation of memrchr
https://sourceware.org/ml/libc-alpha/2019-10/msg00526.html
[PATCH] aarch64: Optimized strcpy for Kunpeng processor.
https://sourceware.org/ml/libc-alpha/2019-10/msg00525.html
[PATCH] aarch64: Optimized memcmp for Kunpeng processor.
https://sourceware.org/ml/libc-alpha/2019-10/msg00524.html
Xuelei Zhang <zhangxuelei4@huawei.com> 于2019年10月17日周四 下午9:16写道：
>
> This is an optimized implementation of the memcpy and memmove on the
> Huawei Kunpeng processor.
>
> Based on the prefetch mechanism on Kunpeng arch, branch to handle 96
> to 2K bytes in memcpy is written without prfm instruction. Hence,
> memcpy has an optimization effect above 128 bytes, 18% improvement
> for copies above 2K bytes, and 38% for larger bytes, such as 32M
> bytes around.
>
> And for memmove, there are two main changes: i) Q register is used
> instead of X register. ii) dst address is aligned instead of src
> address aligned to improve store operation. Hence, memmove
> implementation also has improvement above 128 bytes, that about 30%
> for 2k to 8M bytes, and about 50% for 32M or more.
> ---
> sysdeps/aarch64/multiarch/Makefile | 2 +-
> sysdeps/aarch64/multiarch/ifunc-impl-list.c | 4 +-
> sysdeps/aarch64/multiarch/memcpy.c | 5 +-
> sysdeps/aarch64/multiarch/memcpy_kunpeng.S | 468 ++++++++++++++++++++++++++++
> 4 files changed, 476 insertions(+), 3 deletions(-)
> create mode 100644 sysdeps/aarch64/multiarch/memcpy_kunpeng.S
>
> diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
> index 4150b89a90..37ed49982d 100644
> --- a/sysdeps/aarch64/multiarch/Makefile
> +++ b/sysdeps/aarch64/multiarch/Makefile
> @@ -1,6 +1,6 @@
> ifeq ($(subdir),string)
> sysdep_routines += memcpy_generic memcpy_thunderx memcpy_thunderx2 \
> - memcpy_falkor memmove_falkor \
> + memcpy_falkor memcpy_kunpeng memmove_falkor \
> memset_generic memset_falkor memset_emag \
> memchr_generic memchr_nosimd \
> strlen_generic strlen_asimd
> diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> index be13b916e5..dbbe19096a 100644
> --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> @@ -25,7 +25,7 @@
> #include <stdio.h>
>
> /* Maximum number of IFUNC implementations. */
> -#define MAX_IFUNC 4
> +#define MAX_IFUNC 5
>
> size_t
> __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> @@ -42,11 +42,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx)
> IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx2)
> IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_falkor)
> + IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_kunpeng)
> IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
> IFUNC_IMPL (i, name, memmove,
> IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx)
> IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx2)
> IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_falkor)
> + IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_kunpeng)
> IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_generic))
> IFUNC_IMPL (i, name, memset,
> /* Enable this on non-falkor processors too so that other cores
> diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
> index 13796f987f..b5929e2718 100644
> --- a/sysdeps/aarch64/multiarch/memcpy.c
> +++ b/sysdeps/aarch64/multiarch/memcpy.c
> @@ -32,9 +32,12 @@ extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
> extern __typeof (__redirect_memcpy) __memcpy_thunderx attribute_hidden;
> extern __typeof (__redirect_memcpy) __memcpy_thunderx2 attribute_hidden;
> extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
> +extern __typeof (__redirect_memcpy) __memcpy_kunpeng attribute_hidden;
>
> libc_ifunc (__libc_memcpy,
> - (IS_THUNDERX (midr)
> + IS_KUNPENG(midr)
> + ?__memcpy_kunpeng
> + : (IS_THUNDERX (midr)
> ? __memcpy_thunderx
> : (IS_FALKOR (midr) || IS_PHECDA (midr) || IS_ARES (midr)
> ? __memcpy_falkor
> diff --git a/sysdeps/aarch64/multiarch/memcpy_kunpeng.S b/sysdeps/aarch64/multiarch/memcpy_kunpeng.S
> new file mode 100644
> index 0000000000..385f282224
> --- /dev/null
> +++ b/sysdeps/aarch64/multiarch/memcpy_kunpeng.S
> @@ -0,0 +1,468 @@
> +/* Optimized memcpy and memmove for Huawei Kunpeng processor.
> + Copyright (C) 2018-2019 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
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <sysdep.h>
> +
> +/* Assumptions:
> + *
> + * ARMv8-a, AArch64, unaligned accesses.
> + *
> + */
> +
> +#define dstin x0
> +#define src x1
> +#define count x2
> +#define dst x3
> +#define srcend x4
> +#define dstend x5
> +#define tmp2 x6
> +#define tmp3 x7
> +#define tmp3w w7
> +#define A_l x6
> +#define A_lw w6
> +#define A_h x7
> +#define A_hw w7
> +#define B_l x8
> +#define B_lw w8
> +#define B_h x9
> +#define C_l x10
> +#define C_h x11
> +#define D_l x12
> +#define D_h x13
> +#define E_l src
> +#define E_h count
> +#define F_l srcend
> +#define F_h dst
> +#define G_l count
> +#define G_h dst
> +#define tmp1 x14
> +
> +#define A_q q0
> +#define B_q q1
> +#define C_q q2
> +#define D_q q3
> +#define E_q q4
> +#define F_q q5
> +#define G_q q6
> +#define H_q q7
> +#define I_q q16
> +#define J_q q17
> +
> +#define A_v v0
> +#define B_v v1
> +#define C_v v2
> +#define D_v v3
> +#define E_v v4
> +#define F_v v5
> +#define G_v v6
> +#define H_v v7
> +#define I_v v16
> +#define J_v v17
> +
> +#ifndef MEMMOVE
> +# define MEMMOVE memmove
> +#endif
> +#ifndef MEMCPY
> +# define MEMCPY memcpy
> +#endif
> +
> +#if IS_IN (libc)
> +
> +#undef MEMCPY
> +#define MEMCPY __memcpy_kunpeng
> +#undef MEMMOVE
> +#define MEMMOVE __memmove_kunpeng
> +
> +
> +/* Overlapping large forward memmoves use a loop that copies backwards.
> + Otherwise memcpy is used. Small moves branch to memcopy16 directly.
> + The longer memcpy cases fall through to the memcpy head.
> +*/
> +
> +ENTRY_ALIGN (MEMMOVE, 6)
> +
> + DELOUSE (0)
> + DELOUSE (1)
> + DELOUSE (2)
> +
> + sub tmp1, dstin, src
> + cmp count, 512
> + ccmp tmp1, count, 2, hi
> + b.lo L(move_long)
> + cmp count, 96
> + ccmp tmp1, count, 2, hi
> + b.lo L(move_middle)
> +
> +END (MEMMOVE)
> +libc_hidden_builtin_def (MEMMOVE)
> +
> +
> +/* Copies are split into 4 main cases: small copies of up to 16 bytes,
> + medium copies of 17..96 bytes which are fully unrolled. Long copies
> + of 97..2048 align dst address without prefetching. Large copies
> + of more than 2048 bytes align the destination and use load-and-merge
> + approach in the case src and dst addresses are unaligned not evenly,
> + so that, actual loads and stores are always aligned.
> + Large copies use the loops processing 64 bytes per iteration for
> + unaligned case and 128 bytes per iteration for aligned ones.
> +*/
> +
> +#define MEMCPY_PREFETCH_LDR 640
> +
> + .p2align 4
> +ENTRY (MEMCPY)
> +
> + DELOUSE (0)
> + DELOUSE (1)
> + DELOUSE (2)
> +
> + add srcend, src, count
> + cmp count, 16
> + b.ls L(memcopy16)
> + add dstend, dstin, count
> + cmp count, 96
> + b.hi L(memcopy_long)
> +
> + /* Medium copies: 17..96 bytes. */
> + ldr A_q, [src], #16
> + and tmp1, src, 15
> + ldr E_q, [srcend, -16]
> + cmp count, 64
> + b.gt L(memcpy_copy96)
> + cmp count, 48
> + b.le L(bytes_17_to_48)
> + /* 49..64 bytes */
> + ldp B_q, C_q, [src]
> + str E_q, [dstend, -16]
> + stp A_q, B_q, [dstin]
> + str C_q, [dstin, 32]
> + ret
> +
> +L(bytes_17_to_48):
> + /* 17..48 bytes*/
> + cmp count, 32
> + b.gt L(bytes_32_to_48)
> + /* 17..32 bytes*/
> + str A_q, [dstin]
> + str E_q, [dstend, -16]
> + ret
> +
> +L(bytes_32_to_48):
> + /* 32..48 */
> + ldr B_q, [src]
> + str A_q, [dstin]
> + str E_q, [dstend, -16]
> + str B_q, [dstin, 16]
> + ret
> +
> + .p2align 4
> + /* Small copies: 0..16 bytes. */
> +L(memcopy16):
> + cmp count, 8
> + b.lo L(bytes_0_to_8)
> + ldr A_l, [src]
> + ldr A_h, [srcend, -8]
> + add dstend, dstin, count
> + str A_l, [dstin]
> + str A_h, [dstend, -8]
> + ret
> + .p2align 4
> +
> +L(bytes_0_to_8):
> + tbz count, 2, L(bytes_0_to_3)
> + ldr A_lw, [src]
> + ldr A_hw, [srcend, -4]
> + add dstend, dstin, count
> + str A_lw, [dstin]
> + str A_hw, [dstend, -4]
> + ret
> +
> + /* Copy 0..3 bytes. Use a branchless sequence that copies the same
> + byte 3 times if count==1, or the 2nd byte twice if count==2. */
> +L(bytes_0_to_3):
> + cbz count, 1f
> + lsr tmp1, count, 1
> + ldrb A_lw, [src]
> + ldrb A_hw, [srcend, -1]
> + add dstend, dstin, count
> + ldrb B_lw, [src, tmp1]
> + strb B_lw, [dstin, tmp1]
> + strb A_hw, [dstend, -1]
> + strb A_lw, [dstin]
> +1:
> + ret
> +
> + .p2align 4
> +
> +L(memcpy_copy96):
> + /* Copying 65..96 bytes. A_q (first 16 bytes) and
> + E_q(last 16 bytes) are already loaded. The size
> + is large enough to benefit from aligned loads */
> + bic src, src, 15
> + ldp B_q, C_q, [src]
> + /* Loaded 64 bytes, second 16-bytes chunk can be
> + overlapping with the first chunk by tmp1 bytes.
> + Stored 16 bytes. */
> + sub dst, dstin, tmp1
> + add count, count, tmp1
> + /* The range of count being [65..96] becomes [65..111]
> + after tmp [0..15] gets added to it,
> + count now is <bytes-left-to-load>+48 */
> + cmp count, 80
> + b.gt L(copy96_medium)
> + ldr D_q, [src, 32]
> + stp B_q, C_q, [dst, 16]
> + str D_q, [dst, 48]
> + str A_q, [dstin]
> + str E_q, [dstend, -16]
> + ret
> +
> + .p2align 4
> +L(copy96_medium):
> + ldp D_q, G_q, [src, 32]
> + cmp count, 96
> + b.gt L(copy96_large)
> + stp B_q, C_q, [dst, 16]
> + stp D_q, G_q, [dst, 48]
> + str A_q, [dstin]
> + str E_q, [dstend, -16]
> + ret
> +
> +L(copy96_large):
> + ldr F_q, [src, 64]
> + str B_q, [dst, 16]
> + stp C_q, D_q, [dst, 32]
> + stp G_q, F_q, [dst, 64]
> + str A_q, [dstin]
> + str E_q, [dstend, -16]
> + ret
> +
> + .p2align 4
> +L(memcopy_long):
> + cmp count, 2048
> + b.ls L(copy2048_large)
> + ldr A_q, [src], #16
> + and tmp1, src, 15
> + bic src, src, 15
> + ldp B_q, C_q, [src], #32
> + sub dst, dstin, tmp1
> + add count, count, tmp1
> + add dst, dst, 16
> + ldp D_q, E_q, [src], #32
> + str A_q, [dstin]
> +
> + /* Already loaded 64+16 bytes. Check if at
> + least 64 more bytes left */
> + subs count, count, 64+64+16
> + b.lt L(loop128_exit0)
> + cmp count, MEMCPY_PREFETCH_LDR + 64 + 32
> + b.lt L(loop128)
> + sub count, count, MEMCPY_PREFETCH_LDR + 64 + 32
> +
> + .p2align 4
> +
> +L(loop128_prefetch):
> + prfm pldl1strm, [src, MEMCPY_PREFETCH_LDR]
> + ldp F_q, G_q, [src], #32
> + stp B_q, C_q, [dst], #32
> + ldp H_q, I_q, [src], #32
> + prfm pldl1strm, [src, MEMCPY_PREFETCH_LDR]
> + ldp B_q, C_q, [src], #32
> + stp D_q, E_q, [dst], #32
> + ldp D_q, E_q, [src], #32
> + stp F_q, G_q, [dst], #32
> + stp H_q, I_q, [dst], #32
> + subs count, count, 128
> + b.ge L(loop128_prefetch)
> +
> + add count, count, MEMCPY_PREFETCH_LDR + 64 + 32
> + .p2align 4
> +L(loop128):
> + ldp F_q, G_q, [src], #32
> + ldp H_q, I_q, [src], #32
> + stp B_q, C_q, [dst], #32
> + stp D_q, E_q, [dst], #32
> + subs count, count, 64
> + b.lt L(loop128_exit1)
> + ldp B_q, C_q, [src], #32
> + ldp D_q, E_q, [src], #32
> + stp F_q, G_q, [dst], #32
> + stp H_q, I_q, [dst], #32
> + subs count, count, 64
> + b.ge L(loop128)
> +L(loop128_exit0):
> + ldp F_q, G_q, [srcend, -64]
> + ldp H_q, I_q, [srcend, -32]
> + stp B_q, C_q, [dst], #32
> + stp D_q, E_q, [dst]
> + stp F_q, G_q, [dstend, -64]
> + stp H_q, I_q, [dstend, -32]
> + ret
> +L(loop128_exit1):
> + ldp B_q, C_q, [srcend, -64]
> + ldp D_q, E_q, [srcend, -32]
> + stp F_q, G_q, [dst], #32
> + stp H_q, I_q, [dst]
> + stp B_q, C_q, [dstend, -64]
> + stp D_q, E_q, [dstend, -32]
> + ret
> +
> + /* long copies: 96..2048 bytes */
> +L(copy2048_large):
> + and tmp1, dstin, 15
> + bic dst, dstin, 15
> + ldp D_l, D_h, [src]
> + sub src, src, tmp1
> + add count, count, tmp1 /* Count is now 16 too large. */
> + ldp A_l, A_h, [src, 16]
> + stp D_l, D_h, [dstin]
> + ldp B_l, B_h, [src, 32]
> + ldp C_l, C_h, [src, 48]
> + ldp D_l, D_h, [src, 64]!
> + subs count, count, 128 + 16 /* Test and readjust count. */
> + b.ls L(last64)
> +
> +L(loop64):
> + stp A_l, A_h, [dst, 16]
> + ldp A_l, A_h, [src, 16]
> + stp B_l, B_h, [dst, 32]
> + ldp B_l, B_h, [src, 32]
> + stp C_l, C_h, [dst, 48]
> + ldp C_l, C_h, [src, 48]
> + stp D_l, D_h, [dst, 64]
> + ldp D_l, D_h, [src, 64]
> + add dst, dst, 64
> + add src, src, 64
> + subs count, count, 64
> + b.hi L(loop64)
> +
> + /* Write the last full set of 64 bytes. The remainder is at most 64
> + bytes, so it is safe to always copy 64 bytes from the end even if
> + there is just 1 byte left. */
> +L(last64):
> + ldp E_l, E_h, [srcend, -64]
> + stp A_l, A_h, [dst, 16]
> + ldp A_l, A_h, [srcend, -48]
> + stp B_l, B_h, [dst, 32]
> + ldp B_l, B_h, [srcend, -32]
> + stp C_l, C_h, [dst, 48]
> + ldp C_l, C_h, [srcend, -16]
> + stp D_l, D_h, [dst, 64]
> + stp E_l, E_h, [dstend, -64]
> + stp A_l, A_h, [dstend, -48]
> + stp B_l, B_h, [dstend, -32]
> + stp C_l, C_h, [dstend, -16]
> + ret
> +
> + /* long move: more than 512 bytes align the dstend */
> + .p2align 4
> +L(move_long):
> +1:
> + add srcend, src, count
> + add dstend, dstin, count
> +
> + and tmp1, dstend, 15
> + ldr D_q, [srcend, -16]
> + sub srcend, srcend, tmp1
> + sub count, count, tmp1
> + ldp A_q, B_q, [srcend, -32]
> + str D_q, [dstend, -16]
> + ldp C_q, D_q, [srcend, -64]!
> + sub dstend, dstend, tmp1
> + subs count, count, 128
> + b.ls 2f
> +
> + .p2align 4
> +1:
> + subs count, count, 64
> + stp A_q, B_q, [dstend, -32]
> + ldp A_q, B_q, [srcend, -32]
> + stp C_q, D_q, [dstend, -64]!
> + ldp C_q, D_q, [srcend, -64]!
> + b.hi 1b
> +
> + /* Write the last full set of 64 bytes. The remainder is at most 64
> + bytes, so it is safe to always copy 64 bytes from the start even if
> + there is just 1 byte left. */
> +2:
> + ldp E_q, F_q, [src, 32]
> + ldp G_q, H_q, [src]
> + stp A_q, B_q, [dstend, -32]
> + stp C_q, D_q, [dstend, -64]
> + stp E_q, F_q, [dstin, 32]
> + stp G_q, H_q, [dstin]
> +3: ret
> +
> + /* midlle move: 96..512 bytes */
> + .p2align 4
> +L(move_middle):
> + cbz tmp1, 3f
> + add srcend, src, count
> + prfm PLDL1STRM, [srcend, -64]
> + add dstend, dstin, count
> + and tmp1, dstend, 15
> + ldr D_q, [srcend, -16]
> + sub srcend, srcend, tmp1
> + sub count, count, tmp1
> + ldr A_q, [srcend, -16]
> + str D_q, [dstend, -16]
> + ldr B_q, [srcend, -32]
> + ldr C_q, [srcend, -48]
> + ldr D_q, [srcend, -64]!
> + sub dstend, dstend, tmp1
> + subs count, count, 128
> + b.ls 2f
> +
> +1:
> + str A_q, [dstend, -16]
> + ldr A_q, [srcend, -16]
> + str B_q, [dstend, -32]
> + ldr B_q, [srcend, -32]
> + str C_q, [dstend, -48]
> + ldr C_q, [srcend, -48]
> + str D_q, [dstend, -64]!
> + ldr D_q, [srcend, -64]!
> + subs count, count, 64
> + b.hi 1b
> +
> + /* Write the last full set of 64 bytes. The remainder is at most 64
> + bytes, so it is safe to always copy 64 bytes from the start even if
> + there is just 1 byte left. */
> +2:
> + ldr G_q, [src, 48]
> + str A_q, [dstend, -16]
> + ldr A_q, [src, 32]
> + str B_q, [dstend, -32]
> + ldr B_q, [src, 16]
> + str C_q, [dstend, -48]
> + ldr C_q, [src]
> + str D_q, [dstend, -64]
> + str G_q, [dstin, 48]
> + str A_q, [dstin, 32]
> + str B_q, [dstin, 16]
> + str C_q, [dstin]
> +3: ret
> +
> +
> +END (MEMCPY)
> + .section .rodata
> + .p2align 4
> +
> +libc_hidden_builtin_def (MEMCPY)
> +#endif
> --
> 2.14.1.windows.1
>
>