linux/arch/loongarch/lib/clear_user.S
Huacai Chen a275a82dcd LoongArch: Use alternative to optimize libraries
Use the alternative to optimize common libraries according whether CPU
has UAL (hardware unaligned access support) feature, including memset(),
memcopy(), memmove(), copy_user() and clear_user().

We have tested UnixBench on a Loongson-3A5000 quad-core machine (1.6GHz):

1, One copy, before patch:

System Benchmarks Index Values               BASELINE       RESULT    INDEX
Dhrystone 2 using register variables         116700.0    9566582.0    819.8
Double-Precision Whetstone                       55.0       2805.3    510.1
Execl Throughput                                 43.0       2120.0    493.0
File Copy 1024 bufsize 2000 maxblocks          3960.0     209833.0    529.9
File Copy 256 bufsize 500 maxblocks            1655.0      89400.0    540.2
File Copy 4096 bufsize 8000 maxblocks          5800.0     320036.0    551.8
Pipe Throughput                               12440.0     340624.0    273.8
Pipe-based Context Switching                   4000.0     109939.1    274.8
Process Creation                                126.0       4728.7    375.3
Shell Scripts (1 concurrent)                     42.4       2223.1    524.3
Shell Scripts (8 concurrent)                      6.0        883.1   1471.9
System Call Overhead                          15000.0     518639.1    345.8
                                                                   ========
System Benchmarks Index Score                                         500.2

2, One copy, after patch:

System Benchmarks Index Values               BASELINE       RESULT    INDEX
Dhrystone 2 using register variables         116700.0    9567674.7    819.9
Double-Precision Whetstone                       55.0       2805.5    510.1
Execl Throughput                                 43.0       2392.7    556.4
File Copy 1024 bufsize 2000 maxblocks          3960.0     417804.0   1055.1
File Copy 256 bufsize 500 maxblocks            1655.0     112909.5    682.2
File Copy 4096 bufsize 8000 maxblocks          5800.0    1255207.4   2164.2
Pipe Throughput                               12440.0     555712.0    446.7
Pipe-based Context Switching                   4000.0      99964.5    249.9
Process Creation                                126.0       5192.5    412.1
Shell Scripts (1 concurrent)                     42.4       2302.4    543.0
Shell Scripts (8 concurrent)                      6.0        919.6   1532.6
System Call Overhead                          15000.0     511159.3    340.8
                                                                   ========
System Benchmarks Index Score                                         640.1

3, Four copies, before patch:

System Benchmarks Index Values               BASELINE       RESULT    INDEX
Dhrystone 2 using register variables         116700.0   38268610.5   3279.2
Double-Precision Whetstone                       55.0      11222.2   2040.4
Execl Throughput                                 43.0       7892.0   1835.3
File Copy 1024 bufsize 2000 maxblocks          3960.0     235149.6    593.8
File Copy 256 bufsize 500 maxblocks            1655.0      74959.6    452.9
File Copy 4096 bufsize 8000 maxblocks          5800.0     545048.5    939.7
Pipe Throughput                               12440.0    1337359.0   1075.0
Pipe-based Context Switching                   4000.0     473663.9   1184.2
Process Creation                                126.0      17491.2   1388.2
Shell Scripts (1 concurrent)                     42.4       6865.7   1619.3
Shell Scripts (8 concurrent)                      6.0       1015.9   1693.1
System Call Overhead                          15000.0    1899535.2   1266.4
                                                                   ========
System Benchmarks Index Score                                        1278.3

4, Four copies, after patch:

System Benchmarks Index Values               BASELINE       RESULT    INDEX
Dhrystone 2 using register variables         116700.0   38272815.5   3279.6
Double-Precision Whetstone                       55.0      11222.8   2040.5
Execl Throughput                                 43.0       8839.2   2055.6
File Copy 1024 bufsize 2000 maxblocks          3960.0     313912.9    792.7
File Copy 256 bufsize 500 maxblocks            1655.0      80976.1    489.3
File Copy 4096 bufsize 8000 maxblocks          5800.0    1176594.3   2028.6
Pipe Throughput                               12440.0    2100941.9   1688.9
Pipe-based Context Switching                   4000.0     476696.4   1191.7
Process Creation                                126.0      18394.7   1459.9
Shell Scripts (1 concurrent)                     42.4       7172.2   1691.6
Shell Scripts (8 concurrent)                      6.0       1058.3   1763.9
System Call Overhead                          15000.0    1874714.7   1249.8
                                                                   ========
System Benchmarks Index Score                                        1488.8

Signed-off-by: Jun Yi <yijun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14 08:36:11 +08:00

99 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/alternative-asm.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-extable.h>
#include <asm/cpu.h>
#include <asm/export.h>
#include <asm/regdef.h>
.irp to, 0, 1, 2, 3, 4, 5, 6, 7
.L_fixup_handle_\to\():
addi.d a0, a1, (\to) * (-8)
jr ra
.endr
SYM_FUNC_START(__clear_user)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __clear_user_generic", \
"b __clear_user_fast", CPU_FEATURE_UAL
SYM_FUNC_END(__clear_user)
EXPORT_SYMBOL(__clear_user)
/*
* unsigned long __clear_user_generic(void *addr, size_t size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_generic)
beqz a1, 2f
1: st.b zero, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, -1
bgtz a1, 1b
2: move a0, a1
jr ra
_asm_extable 1b, .L_fixup_handle_0
SYM_FUNC_END(__clear_user_generic)
/*
* unsigned long __clear_user_fast(void *addr, unsigned long size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_fast)
beqz a1, 10f
ori a2, zero, 64
blt a1, a2, 9f
/* set 64 bytes at a time */
1: st.d zero, a0, 0
2: st.d zero, a0, 8
3: st.d zero, a0, 16
4: st.d zero, a0, 24
5: st.d zero, a0, 32
6: st.d zero, a0, 40
7: st.d zero, a0, 48
8: st.d zero, a0, 56
addi.d a0, a0, 64
addi.d a1, a1, -64
bge a1, a2, 1b
beqz a1, 10f
/* set the remaining bytes */
9: st.b zero, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, -1
bgt a1, zero, 9b
/* return */
10: move a0, a1
jr ra
/* fixup and ex_table */
_asm_extable 1b, .L_fixup_handle_0
_asm_extable 2b, .L_fixup_handle_1
_asm_extable 3b, .L_fixup_handle_2
_asm_extable 4b, .L_fixup_handle_3
_asm_extable 5b, .L_fixup_handle_4
_asm_extable 6b, .L_fixup_handle_5
_asm_extable 7b, .L_fixup_handle_6
_asm_extable 8b, .L_fixup_handle_7
_asm_extable 9b, .L_fixup_handle_0
SYM_FUNC_END(__clear_user_fast)