arch/loongarch/lib/clear_user.S | 137 +++++++++++++++-- arch/loongarch/lib/copy_user.S | 251 +++++++++++++++++++++++++------- arch/loongarch/lib/memcpy.S | 147 +++++++++++++++---- arch/loongarch/lib/memmove.S | 120 ++++++++------- arch/loongarch/lib/memset.S | 117 ++++++++++++--- 5 files changed, 605 insertions(+), 167 deletions(-)
We use a jump table to dispatch cases for short data lengths, and for long data
lengths, we use unaligned memory access instruction to process the first and
last 8 bytes. The data in the middle is processed at an aligned destination
address.
We have tested micro-bench[1] on a Loongson-3C5000 16-core machine (2.2GHz):
1. memset
| length | src offset | dst offset | speed before | speed after | % |
|--------|------------|------------|--------------|-------------|---------|
| 8 | 0 | 0 | 696.191 | 1518.785 | 118.16% |
| 8 | 0 | 1 | 696.325 | 1518.937 | 118.14% |
| 50 | 0 | 0 | 969.976 | 8053.902 | 730.32% |
| 50 | 0 | 1 | 970.034 | 8058.475 | 730.74% |
| 300 | 0 | 0 | 5876.612 | 16544.703 | 181.53% |
| 300 | 0 | 1 | 5030.849 | 16549.011 | 228.95% |
| 1200 | 0 | 0 | 11797.077 | 16752.137 | 42.00% |
| 1200 | 0 | 1 | 5687.141 | 16645.233 | 192.68% |
| 4000 | 0 | 0 | 15723.27 | 16761.557 | 6.60% |
| 4000 | 0 | 1 | 5906.114 | 16732.316 | 183.30% |
| 8000 | 0 | 0 | 16751.403 | 16770.002 | 0.11% |
| 8000 | 0 | 1 | 5995.449 | 16754.07 | 179.45% |
2. memcpy
| length | src offset | dst offset | speed before | speed after | % |
|--------|------------|------------|--------------|-------------|---------|
| 8 | 0 | 0 | 696.2 | 1670.605 | 139.96% |
| 8 | 0 | 1 | 696.325 | 1671.138 | 139.99% |
| 50 | 0 | 0 | 969.974 | 8724.999 | 799.51% |
| 50 | 0 | 1 | 970.032 | 8730.138 | 799.98% |
| 300 | 0 | 0 | 5564.662 | 16272.652 | 192.43% |
| 300 | 0 | 1 | 4670.436 | 14972.842 | 220.59% |
| 1200 | 0 | 0 | 10740.23 | 16751.728 | 55.97% |
| 1200 | 0 | 1 | 5027.741 | 14874.564 | 195.85% |
| 4000 | 0 | 0 | 15122.367 | 16737.642 | 10.68% |
| 4000 | 0 | 1 | 5536.918 | 14890.397 | 168.93% |
| 8000 | 0 | 0 | 16505.453 | 16553.543 | 0.29% |
| 8000 | 0 | 1 | 5821.619 | 14841.804 | 154.94% |
3. memmove
| length | src offset | dst offset | speed before | speed after | % |
|--------|------------|------------|--------------|-------------|---------|
| 8 | 0 | 0 | 982.693 | 1670.568 | 70.00% |
| 8 | 0 | 1 | 983.023 | 1671.174 | 70.00% |
| 50 | 0 | 0 | 1230.87 | 8727.625 | 609.06% |
| 50 | 0 | 1 | 1232.515 | 8730.138 | 608.32% |
| 300 | 0 | 0 | 6490.375 | 16296.993 | 151.09% |
| 300 | 0 | 1 | 4282.687 | 14972.842 | 249.61% |
| 1200 | 0 | 0 | 11742.755 | 16752.546 | 42.66% |
| 1200 | 0 | 1 | 5039.338 | 14872.951 | 195.14% |
| 4000 | 0 | 0 | 15467.786 | 16737.09 | 8.21% |
| 4000 | 0 | 1 | 5009.905 | 14890.542 | 197.22% |
| 8000 | 0 | 0 | 16489.664 | 16553.273 | 0.39% |
| 8000 | 0 | 1 | 5823.786 | 14858.646 | 155.14% |
* speed: MB/s
* length: byte
[1] https://github.com/heiher/mem-bench
Signed-off-by: WANG rui <wangrui@loongson.cn>
---
arch/loongarch/lib/clear_user.S | 137 +++++++++++++++--
arch/loongarch/lib/copy_user.S | 251 +++++++++++++++++++++++++-------
arch/loongarch/lib/memcpy.S | 147 +++++++++++++++----
arch/loongarch/lib/memmove.S | 120 ++++++++-------
arch/loongarch/lib/memset.S | 117 ++++++++++++---
5 files changed, 605 insertions(+), 167 deletions(-)
diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S
index 2dc48e61a2c8..02f112b265cd 100644
--- a/arch/loongarch/lib/clear_user.S
+++ b/arch/loongarch/lib/clear_user.S
@@ -13,7 +13,14 @@
.irp to, 0, 1, 2, 3, 4, 5, 6, 7
.L_fixup_handle_\to\():
- addi.d a0, a1, (\to) * (-8)
+ sub.d a0, a2, a0
+ addi.d a0, a0, (\to) * (-8)
+ jr ra
+.endr
+
+.irp to, 0, 2, 4
+.L_fixup_handle_s\to\():
+ addi.d a0, a1, -\to
jr ra
.endr
@@ -44,7 +51,7 @@ SYM_FUNC_START(__clear_user_generic)
2: move a0, a1
jr ra
- _asm_extable 1b, .L_fixup_handle_0
+ _asm_extable 1b, .L_fixup_handle_s0
SYM_FUNC_END(__clear_user_generic)
/*
@@ -54,12 +61,22 @@ SYM_FUNC_END(__clear_user_generic)
* a1: size
*/
SYM_FUNC_START(__clear_user_fast)
- beqz a1, 10f
+ sltui t0, a1, 9
+ bnez t0, .Lsmall
- ori a2, zero, 64
- blt a1, a2, 9f
+ add.d a2, a0, a1
+0: st.d zero, a0, 0
+
+ /* align up address */
+ andi t1, a0, 7
+ sub.d a0, a0, t1
+ addi.d a0, a0, 8
+
+ addi.d a3, a2, -64
+ bgeu a0, a3, .Llt64
/* set 64 bytes at a time */
+.Lloop64:
1: st.d zero, a0, 0
2: st.d zero, a0, 8
3: st.d zero, a0, 16
@@ -68,24 +85,95 @@ SYM_FUNC_START(__clear_user_fast)
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
+ bltu a0, a3, .Lloop64
/* set the remaining bytes */
-9: st.b zero, a0, 0
- addi.d a0, a0, 1
- addi.d a1, a1, -1
- bgt a1, zero, 9b
+.Llt64:
+ addi.d a3, a2, -32
+ bgeu a0, a3, .Llt32
+9: st.d zero, a0, 0
+10: st.d zero, a0, 8
+11: st.d zero, a0, 16
+12: st.d zero, a0, 24
+ addi.d a0, a0, 32
+
+.Llt32:
+ addi.d a3, a2, -16
+ bgeu a0, a3, .Llt16
+13: st.d zero, a0, 0
+14: st.d zero, a0, 8
+ addi.d a0, a0, 16
+
+.Llt16:
+ addi.d a3, a2, -8
+ bgeu a0, a3, .Llt8
+15: st.d zero, a0, 0
+
+.Llt8:
+16: st.d zero, a2, -8
/* return */
-10: move a0, a1
+ move a0, zero
+ jr ra
+
+ .align 4
+.Lsmall:
+ pcaddi t0, 4
+ slli.d a2, a1, 4
+ add.d t0, t0, a2
+ jr t0
+
+ .align 4
+ move a0, zero
+ jr ra
+
+ .align 4
+17: st.b zero, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 4
+18: st.h zero, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 4
+19: st.h zero, a0, 0
+20: st.b zero, a0, 2
+ move a0, zero
+ jr ra
+
+ .align 4
+21: st.w zero, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 4
+22: st.w zero, a0, 0
+23: st.b zero, a0, 4
+ move a0, zero
+ jr ra
+
+ .align 4
+24: st.w zero, a0, 0
+25: st.h zero, a0, 4
+ move a0, zero
+ jr ra
+
+ .align 4
+26: st.w zero, a0, 0
+27: st.w zero, a0, 3
+ move a0, zero
+ jr ra
+
+ .align 4
+28: st.d zero, a0, 0
+ move a0, zero
jr ra
/* fixup and ex_table */
+ _asm_extable 0b, .L_fixup_handle_0
_asm_extable 1b, .L_fixup_handle_0
_asm_extable 2b, .L_fixup_handle_1
_asm_extable 3b, .L_fixup_handle_2
@@ -95,4 +183,23 @@ SYM_FUNC_START(__clear_user_fast)
_asm_extable 7b, .L_fixup_handle_6
_asm_extable 8b, .L_fixup_handle_7
_asm_extable 9b, .L_fixup_handle_0
+ _asm_extable 10b, .L_fixup_handle_1
+ _asm_extable 11b, .L_fixup_handle_2
+ _asm_extable 12b, .L_fixup_handle_3
+ _asm_extable 13b, .L_fixup_handle_0
+ _asm_extable 14b, .L_fixup_handle_1
+ _asm_extable 15b, .L_fixup_handle_0
+ _asm_extable 16b, .L_fixup_handle_1
+ _asm_extable 17b, .L_fixup_handle_s0
+ _asm_extable 18b, .L_fixup_handle_s0
+ _asm_extable 19b, .L_fixup_handle_s0
+ _asm_extable 20b, .L_fixup_handle_s2
+ _asm_extable 21b, .L_fixup_handle_s0
+ _asm_extable 22b, .L_fixup_handle_s0
+ _asm_extable 23b, .L_fixup_handle_s4
+ _asm_extable 24b, .L_fixup_handle_s0
+ _asm_extable 25b, .L_fixup_handle_s4
+ _asm_extable 26b, .L_fixup_handle_s0
+ _asm_extable 27b, .L_fixup_handle_s4
+ _asm_extable 28b, .L_fixup_handle_s0
SYM_FUNC_END(__clear_user_fast)
diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S
index 55ac6020a1ad..b21f6d5d38f5 100644
--- a/arch/loongarch/lib/copy_user.S
+++ b/arch/loongarch/lib/copy_user.S
@@ -13,7 +13,14 @@
.irp to, 0, 1, 2, 3, 4, 5, 6, 7
.L_fixup_handle_\to\():
- addi.d a0, a2, (\to) * (-8)
+ sub.d a0, a2, a0
+ addi.d a0, a0, (\to) * (-8)
+ jr ra
+.endr
+
+.irp to, 0, 2, 4
+.L_fixup_handle_s\to\():
+ addi.d a0, a2, -\to
jr ra
.endr
@@ -47,8 +54,8 @@ SYM_FUNC_START(__copy_user_generic)
3: move a0, a2
jr ra
- _asm_extable 1b, .L_fixup_handle_0
- _asm_extable 2b, .L_fixup_handle_0
+ _asm_extable 1b, .L_fixup_handle_s0
+ _asm_extable 2b, .L_fixup_handle_s0
SYM_FUNC_END(__copy_user_generic)
/*
@@ -59,65 +66,209 @@ SYM_FUNC_END(__copy_user_generic)
* a2: n
*/
SYM_FUNC_START(__copy_user_fast)
- beqz a2, 19f
+ sltui t0, a2, 9
+ bnez t0, .Lsmall
- ori a3, zero, 64
- blt a2, a3, 17f
+ add.d a3, a1, a2
+ add.d a2, a0, a2
+0: ld.d t0, a1, 0
+1: st.d t0, a0, 0
- /* copy 64 bytes at a time */
-1: ld.d t0, a1, 0
-2: ld.d t1, a1, 8
-3: ld.d t2, a1, 16
-4: ld.d t3, a1, 24
-5: ld.d t4, a1, 32
-6: ld.d t5, a1, 40
-7: ld.d t6, a1, 48
-8: ld.d t7, a1, 56
-9: st.d t0, a0, 0
-10: st.d t1, a0, 8
-11: st.d t2, a0, 16
-12: st.d t3, a0, 24
-13: st.d t4, a0, 32
-14: st.d t5, a0, 40
-15: st.d t6, a0, 48
-16: st.d t7, a0, 56
+ /* align up destination address */
+ andi t1, a0, 7
+ sub.d t0, zero, t1
+ addi.d t0, t0, 8
+ add.d a1, a1, t0
+ add.d a0, a0, t0
- addi.d a0, a0, 64
- addi.d a1, a1, 64
- addi.d a2, a2, -64
- bge a2, a3, 1b
+ addi.d a4, a3, -64
+ bgeu a1, a4, .Llt64
- beqz a2, 19f
+ /* copy 64 bytes at a time */
+.Lloop64:
+2: ld.d t0, a1, 0
+3: ld.d t1, a1, 8
+4: ld.d t2, a1, 16
+5: ld.d t3, a1, 24
+6: ld.d t4, a1, 32
+7: ld.d t5, a1, 40
+8: ld.d t6, a1, 48
+9: ld.d t7, a1, 56
+ addi.d a1, a1, 64
+10: st.d t0, a0, 0
+11: st.d t1, a0, 8
+12: st.d t2, a0, 16
+13: st.d t3, a0, 24
+14: st.d t4, a0, 32
+15: st.d t5, a0, 40
+16: st.d t6, a0, 48
+17: st.d t7, a0, 56
+ addi.d a0, a0, 64
+ bltu a1, a4, .Lloop64
/* copy the remaining bytes */
-17: ld.b t0, a1, 0
-18: st.b t0, a0, 0
- addi.d a0, a0, 1
- addi.d a1, a1, 1
- addi.d a2, a2, -1
- bgt a2, zero, 17b
+.Llt64:
+ addi.d a4, a3, -32
+ bgeu a1, a4, .Llt32
+18: ld.d t0, a1, 0
+19: ld.d t1, a1, 8
+20: ld.d t2, a1, 16
+21: ld.d t3, a1, 24
+ addi.d a1, a1, 32
+22: st.d t0, a0, 0
+23: st.d t1, a0, 8
+24: st.d t2, a0, 16
+25: st.d t3, a0, 24
+ addi.d a0, a0, 32
+
+.Llt32:
+ addi.d a4, a3, -16
+ bgeu a1, a4, .Llt16
+26: ld.d t0, a1, 0
+27: ld.d t1, a1, 8
+ addi.d a1, a1, 16
+28: st.d t0, a0, 0
+29: st.d t1, a0, 8
+ addi.d a0, a0, 16
+
+.Llt16:
+ addi.d a4, a3, -8
+ bgeu a1, a4, .Llt8
+30: ld.d t0, a1, 0
+31: st.d t0, a0, 0
+
+.Llt8:
+32: ld.d t0, a3, -8
+33: st.d t0, a2, -8
/* return */
-19: move a0, a2
+ move a0, zero
+ jr ra
+
+ .align 5
+.Lsmall:
+ pcaddi t0, 8
+ slli.d a3, a2, 5
+ add.d t0, t0, a3
+ jr t0
+
+ .align 5
+ move a0, zero
+ jr ra
+
+ .align 5
+34: ld.b t0, a1, 0
+35: st.b t0, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 5
+36: ld.h t0, a1, 0
+37: st.h t0, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 5
+38: ld.h t0, a1, 0
+39: ld.b t1, a1, 2
+40: st.h t0, a0, 0
+41: st.b t1, a0, 2
+ move a0, zero
+ jr ra
+
+ .align 5
+42: ld.w t0, a1, 0
+43: st.w t0, a0, 0
+ move a0, zero
+ jr ra
+
+ .align 5
+44: ld.w t0, a1, 0
+45: ld.b t1, a1, 4
+46: st.w t0, a0, 0
+47: st.b t1, a0, 4
+ move a0, zero
+ jr ra
+
+ .align 5
+48: ld.w t0, a1, 0
+49: ld.h t1, a1, 4
+50: st.w t0, a0, 0
+51: st.h t1, a0, 4
+ move a0, zero
+ jr ra
+
+ .align 5
+52: ld.w t0, a1, 0
+53: ld.w t1, a1, 3
+54: st.w t0, a0, 0
+55: st.w t1, a0, 3
+ move a0, zero
+ jr ra
+
+ .align 5
+56: ld.d t0, a1, 0
+57: st.d t0, a0, 0
+ move a0, zero
jr ra
/* fixup and ex_table */
+ _asm_extable 0b, .L_fixup_handle_0
_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 2b, .L_fixup_handle_0
+ _asm_extable 3b, .L_fixup_handle_0
+ _asm_extable 4b, .L_fixup_handle_0
+ _asm_extable 5b, .L_fixup_handle_0
+ _asm_extable 6b, .L_fixup_handle_0
+ _asm_extable 7b, .L_fixup_handle_0
+ _asm_extable 8b, .L_fixup_handle_0
_asm_extable 9b, .L_fixup_handle_0
- _asm_extable 10b, .L_fixup_handle_1
- _asm_extable 11b, .L_fixup_handle_2
- _asm_extable 12b, .L_fixup_handle_3
- _asm_extable 13b, .L_fixup_handle_4
- _asm_extable 14b, .L_fixup_handle_5
- _asm_extable 15b, .L_fixup_handle_6
- _asm_extable 16b, .L_fixup_handle_7
- _asm_extable 17b, .L_fixup_handle_0
+ _asm_extable 10b, .L_fixup_handle_0
+ _asm_extable 11b, .L_fixup_handle_1
+ _asm_extable 12b, .L_fixup_handle_2
+ _asm_extable 13b, .L_fixup_handle_3
+ _asm_extable 14b, .L_fixup_handle_4
+ _asm_extable 15b, .L_fixup_handle_5
+ _asm_extable 16b, .L_fixup_handle_6
+ _asm_extable 17b, .L_fixup_handle_7
_asm_extable 18b, .L_fixup_handle_0
+ _asm_extable 19b, .L_fixup_handle_0
+ _asm_extable 20b, .L_fixup_handle_0
+ _asm_extable 21b, .L_fixup_handle_0
+ _asm_extable 22b, .L_fixup_handle_0
+ _asm_extable 23b, .L_fixup_handle_1
+ _asm_extable 24b, .L_fixup_handle_2
+ _asm_extable 25b, .L_fixup_handle_3
+ _asm_extable 26b, .L_fixup_handle_0
+ _asm_extable 27b, .L_fixup_handle_0
+ _asm_extable 28b, .L_fixup_handle_0
+ _asm_extable 29b, .L_fixup_handle_1
+ _asm_extable 30b, .L_fixup_handle_0
+ _asm_extable 31b, .L_fixup_handle_0
+ _asm_extable 32b, .L_fixup_handle_0
+ _asm_extable 33b, .L_fixup_handle_1
+ _asm_extable 34b, .L_fixup_handle_s0
+ _asm_extable 35b, .L_fixup_handle_s0
+ _asm_extable 36b, .L_fixup_handle_s0
+ _asm_extable 37b, .L_fixup_handle_s0
+ _asm_extable 38b, .L_fixup_handle_s0
+ _asm_extable 39b, .L_fixup_handle_s0
+ _asm_extable 40b, .L_fixup_handle_s0
+ _asm_extable 41b, .L_fixup_handle_s2
+ _asm_extable 42b, .L_fixup_handle_s0
+ _asm_extable 43b, .L_fixup_handle_s0
+ _asm_extable 44b, .L_fixup_handle_s0
+ _asm_extable 45b, .L_fixup_handle_s0
+ _asm_extable 46b, .L_fixup_handle_s0
+ _asm_extable 47b, .L_fixup_handle_s4
+ _asm_extable 48b, .L_fixup_handle_s0
+ _asm_extable 49b, .L_fixup_handle_s0
+ _asm_extable 50b, .L_fixup_handle_s0
+ _asm_extable 51b, .L_fixup_handle_s4
+ _asm_extable 52b, .L_fixup_handle_s0
+ _asm_extable 53b, .L_fixup_handle_s0
+ _asm_extable 54b, .L_fixup_handle_s0
+ _asm_extable 55b, .L_fixup_handle_s4
+ _asm_extable 56b, .L_fixup_handle_s0
+ _asm_extable 57b, .L_fixup_handle_s0
SYM_FUNC_END(__copy_user_fast)
diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S
index 3b7e1dec7109..39ce6621c704 100644
--- a/arch/loongarch/lib/memcpy.S
+++ b/arch/loongarch/lib/memcpy.S
@@ -44,6 +44,66 @@ SYM_FUNC_START(__memcpy_generic)
SYM_FUNC_END(__memcpy_generic)
_ASM_NOKPROBE(__memcpy_generic)
+ .align 5
+SYM_FUNC_START_NOALIGN(__memcpy_small)
+ pcaddi t0, 8
+ slli.d a2, a2, 5
+ add.d t0, t0, a2
+ jr t0
+
+ .align 5
+0: jr ra
+
+ .align 5
+1: ld.b t0, a1, 0
+ st.b t0, a0, 0
+ jr ra
+
+ .align 5
+2: ld.h t0, a1, 0
+ st.h t0, a0, 0
+ jr ra
+
+ .align 5
+3: ld.h t0, a1, 0
+ ld.b t1, a1, 2
+ st.h t0, a0, 0
+ st.b t1, a0, 2
+ jr ra
+
+ .align 5
+4: ld.w t0, a1, 0
+ st.w t0, a0, 0
+ jr ra
+
+ .align 5
+5: ld.w t0, a1, 0
+ ld.b t1, a1, 4
+ st.w t0, a0, 0
+ st.b t1, a0, 4
+ jr ra
+
+ .align 5
+6: ld.w t0, a1, 0
+ ld.h t1, a1, 4
+ st.w t0, a0, 0
+ st.h t1, a0, 4
+ jr ra
+
+ .align 5
+7: ld.w t0, a1, 0
+ ld.w t1, a1, 3
+ st.w t0, a0, 0
+ st.w t1, a0, 3
+ jr ra
+
+ .align 5
+8: ld.d t0, a1, 0
+ st.d t0, a0, 0
+ jr ra
+SYM_FUNC_END(__memcpy_small)
+_ASM_NOKPROBE(__memcpy_small)
+
/*
* void *__memcpy_fast(void *dst, const void *src, size_t n)
*
@@ -52,14 +112,27 @@ _ASM_NOKPROBE(__memcpy_generic)
* a2: n
*/
SYM_FUNC_START(__memcpy_fast)
- move a3, a0
- beqz a2, 3f
+ sltui t0, a2, 9
+ bnez t0, __memcpy_small
+
+ add.d a3, a1, a2
+ add.d a2, a0, a2
+ ld.d a6, a1, 0
+ ld.d a7, a3, -8
+
+ /* align up destination address */
+ andi t1, a0, 7
+ sub.d t0, zero, t1
+ addi.d t0, t0, 8
+ add.d a1, a1, t0
+ add.d a5, a0, t0
- ori a4, zero, 64
- blt a2, a4, 2f
+ addi.d a4, a3, -64
+ bgeu a1, a4, .Llt64
/* copy 64 bytes at a time */
-1: ld.d t0, a1, 0
+.Lloop64:
+ ld.d t0, a1, 0
ld.d t1, a1, 8
ld.d t2, a1, 16
ld.d t3, a1, 24
@@ -67,32 +140,54 @@ SYM_FUNC_START(__memcpy_fast)
ld.d t5, a1, 40
ld.d t6, a1, 48
ld.d t7, a1, 56
- st.d t0, a0, 0
- st.d t1, a0, 8
- st.d t2, a0, 16
- st.d t3, a0, 24
- st.d t4, a0, 32
- st.d t5, a0, 40
- st.d t6, a0, 48
- st.d t7, a0, 56
-
- addi.d a0, a0, 64
addi.d a1, a1, 64
- addi.d a2, a2, -64
- bge a2, a4, 1b
-
- beqz a2, 3f
+ st.d t0, a5, 0
+ st.d t1, a5, 8
+ st.d t2, a5, 16
+ st.d t3, a5, 24
+ st.d t4, a5, 32
+ st.d t5, a5, 40
+ st.d t6, a5, 48
+ st.d t7, a5, 56
+ addi.d a5, a5, 64
+ bltu a1, a4, .Lloop64
/* copy the remaining bytes */
-2: ld.b t0, a1, 0
- st.b t0, a0, 0
- addi.d a0, a0, 1
- addi.d a1, a1, 1
- addi.d a2, a2, -1
- bgt a2, zero, 2b
+.Llt64:
+ addi.d a4, a3, -32
+ bgeu a1, a4, .Llt32
+ ld.d t0, a1, 0
+ ld.d t1, a1, 8
+ ld.d t2, a1, 16
+ ld.d t3, a1, 24
+ addi.d a1, a1, 32
+ st.d t0, a5, 0
+ st.d t1, a5, 8
+ st.d t2, a5, 16
+ st.d t3, a5, 24
+ addi.d a5, a5, 32
+
+.Llt32:
+ addi.d a4, a3, -16
+ bgeu a1, a4, .Llt16
+ ld.d t0, a1, 0
+ ld.d t1, a1, 8
+ addi.d a1, a1, 16
+ st.d t0, a5, 0
+ st.d t1, a5, 8
+ addi.d a5, a5, 16
+
+.Llt16:
+ addi.d a4, a3, -8
+ bgeu a1, a4, .Llt8
+ ld.d t0, a1, 0
+ st.d t0, a5, 0
+
+.Llt8:
+ st.d a6, a0, 0
+ st.d a7, a2, -8
/* return */
-3: move a0, a3
jr ra
SYM_FUNC_END(__memcpy_fast)
_ASM_NOKPROBE(__memcpy_fast)
diff --git a/arch/loongarch/lib/memmove.S b/arch/loongarch/lib/memmove.S
index b796c3d6da05..45b725ba7867 100644
--- a/arch/loongarch/lib/memmove.S
+++ b/arch/loongarch/lib/memmove.S
@@ -11,23 +11,9 @@
#include <asm/regdef.h>
SYM_FUNC_START(memmove)
- blt a0, a1, 1f /* dst < src, memcpy */
- blt a1, a0, 3f /* src < dst, rmemcpy */
+ blt a0, a1, memcpy /* dst < src, memcpy */
+ blt a1, a0, rmemcpy /* src < dst, rmemcpy */
jr ra /* dst == src, return */
-
- /* if (src - dst) < 64, copy 1 byte at a time */
-1: ori a3, zero, 64
- sub.d t0, a1, a0
- blt t0, a3, 2f
- b memcpy
-2: b __memcpy_generic
-
- /* if (dst - src) < 64, copy 1 byte at a time */
-3: ori a3, zero, 64
- sub.d t0, a0, a1
- blt t0, a3, 4f
- b rmemcpy
-4: b __rmemcpy_generic
SYM_FUNC_END(memmove)
_ASM_NOKPROBE(memmove)
@@ -76,50 +62,80 @@ _ASM_NOKPROBE(__rmemcpy_generic)
* a2: n
*/
SYM_FUNC_START(__rmemcpy_fast)
- move a3, a0
- beqz a2, 3f
+ sltui t0, a2, 9
+ bnez t0, __memcpy_small
- add.d a0, a0, a2
- add.d a1, a1, a2
+ add.d a3, a1, a2
+ add.d a2, a0, a2
+ ld.d a6, a1, 0
+ ld.d a7, a3, -8
+
+ /* align up destination address */
+ andi t1, a2, 7
+ sub.d a3, a3, t1
+ sub.d a5, a2, t1
- ori a4, zero, 64
- blt a2, a4, 2f
+ addi.d a4, a1, 64
+ bgeu a4, a3, .Llt64
/* copy 64 bytes at a time */
-1: ld.d t0, a1, -8
- ld.d t1, a1, -16
- ld.d t2, a1, -24
- ld.d t3, a1, -32
- ld.d t4, a1, -40
- ld.d t5, a1, -48
- ld.d t6, a1, -56
- ld.d t7, a1, -64
- st.d t0, a0, -8
- st.d t1, a0, -16
- st.d t2, a0, -24
- st.d t3, a0, -32
- st.d t4, a0, -40
- st.d t5, a0, -48
- st.d t6, a0, -56
- st.d t7, a0, -64
-
- addi.d a0, a0, -64
- addi.d a1, a1, -64
- addi.d a2, a2, -64
- bge a2, a4, 1b
-
- beqz a2, 3f
+.Lloop64:
+ ld.d t0, a3, -8
+ ld.d t1, a3, -16
+ ld.d t2, a3, -24
+ ld.d t3, a3, -32
+ ld.d t4, a3, -40
+ ld.d t5, a3, -48
+ ld.d t6, a3, -56
+ ld.d t7, a3, -64
+ addi.d a3, a3, -64
+ st.d t0, a5, -8
+ st.d t1, a5, -16
+ st.d t2, a5, -24
+ st.d t3, a5, -32
+ st.d t4, a5, -40
+ st.d t5, a5, -48
+ st.d t6, a5, -56
+ st.d t7, a5, -64
+ addi.d a5, a5, -64
+ bltu a4, a3, .Lloop64
/* copy the remaining bytes */
-2: ld.b t0, a1, -1
- st.b t0, a0, -1
- addi.d a0, a0, -1
- addi.d a1, a1, -1
- addi.d a2, a2, -1
- bgt a2, zero, 2b
+.Llt64:
+ addi.d a4, a1, 32
+ bgeu a4, a3, .Llt32
+ ld.d t0, a3, -8
+ ld.d t1, a3, -16
+ ld.d t2, a3, -24
+ ld.d t3, a3, -32
+ addi.d a3, a3, -32
+ st.d t0, a5, -8
+ st.d t1, a5, -16
+ st.d t2, a5, -24
+ st.d t3, a5, -32
+ addi.d a5, a5, -32
+
+.Llt32:
+ addi.d a4, a1, 16
+ bgeu a4, a3, .Llt16
+ ld.d t0, a3, -8
+ ld.d t1, a3, -16
+ addi.d a3, a3, -16
+ st.d t0, a5, -8
+ st.d t1, a5, -16
+ addi.d a5, a5, -16
+
+.Llt16:
+ addi.d a4, a1, 8
+ bgeu a4, a3, .Llt8
+ ld.d t0, a3, -8
+ st.d t0, a5, -8
+
+.Llt8:
+ st.d a6, a0, 0
+ st.d a7, a2, -8
/* return */
-3: move a0, a3
jr ra
SYM_FUNC_END(__rmemcpy_fast)
_ASM_NOKPROBE(__rmemcpy_fast)
diff --git a/arch/loongarch/lib/memset.S b/arch/loongarch/lib/memset.S
index a9eb732ab2ad..c5836d916736 100644
--- a/arch/loongarch/lib/memset.S
+++ b/arch/loongarch/lib/memset.S
@@ -56,39 +56,108 @@ _ASM_NOKPROBE(__memset_generic)
* a2: n
*/
SYM_FUNC_START(__memset_fast)
- move a3, a0
- beqz a2, 3f
-
- ori a4, zero, 64
- blt a2, a4, 2f
-
/* fill a1 to 64 bits */
fill_to_64 a1
- /* set 64 bytes at a time */
-1: st.d a1, a0, 0
- st.d a1, a0, 8
- st.d a1, a0, 16
- st.d a1, a0, 24
- st.d a1, a0, 32
- st.d a1, a0, 40
- st.d a1, a0, 48
- st.d a1, a0, 56
+ sltui t0, a2, 9
+ bnez t0, .Lsmall
- addi.d a0, a0, 64
- addi.d a2, a2, -64
- bge a2, a4, 1b
+ add.d a2, a0, a2
+ st.d a1, a0, 0
- beqz a2, 3f
+ /* align up address */
+ andi t1, a0, 7
+ sub.d a3, a0, t1
+ addi.d a3, a3, 8
+
+ addi.d a4, a2, -64
+ bgeu a3, a4, .Llt64
+
+ /* set 64 bytes at a time */
+.Lloop64:
+ st.d a1, a3, 0
+ st.d a1, a3, 8
+ st.d a1, a3, 16
+ st.d a1, a3, 24
+ st.d a1, a3, 32
+ st.d a1, a3, 40
+ st.d a1, a3, 48
+ st.d a1, a3, 56
+ addi.d a3, a3, 64
+ bltu a3, a4, .Lloop64
/* set the remaining bytes */
-2: st.b a1, a0, 0
- addi.d a0, a0, 1
- addi.d a2, a2, -1
- bgt a2, zero, 2b
+.Llt64:
+ addi.d a4, a2, -32
+ bgeu a3, a4, .Llt32
+ st.d a1, a3, 0
+ st.d a1, a3, 8
+ st.d a1, a3, 16
+ st.d a1, a3, 24
+ addi.d a3, a3, 32
+
+.Llt32:
+ addi.d a4, a2, -16
+ bgeu a3, a4, .Llt16
+ st.d a1, a3, 0
+ st.d a1, a3, 8
+ addi.d a3, a3, 16
+
+.Llt16:
+ addi.d a4, a2, -8
+ bgeu a3, a4, .Llt8
+ st.d a1, a3, 0
+
+.Llt8:
+ st.d a1, a2, -8
/* return */
-3: move a0, a3
+ jr ra
+
+ .align 4
+.Lsmall:
+ pcaddi t0, 4
+ slli.d a2, a2, 4
+ add.d t0, t0, a2
+ jr t0
+
+ .align 4
+0: jr ra
+
+ .align 4
+1: st.b a1, a0, 0
+ jr ra
+
+ .align 4
+2: st.h a1, a0, 0
+ jr ra
+
+ .align 4
+3: st.h a1, a0, 0
+ st.b a1, a0, 2
+ jr ra
+
+ .align 4
+4: st.w a1, a0, 0
+ jr ra
+
+ .align 4
+5: st.w a1, a0, 0
+ st.b a1, a0, 4
+ jr ra
+
+ .align 4
+6: st.w a1, a0, 0
+ st.h a1, a0, 4
+ jr ra
+
+ .align 4
+7: st.w a1, a0, 0
+ st.w a1, a0, 3
+ jr ra
+
+ .align 4
+8: st.d a1, a0, 0
jr ra
SYM_FUNC_END(__memset_fast)
_ASM_NOKPROBE(__memset_fast)
--
2.40.0On Mon, 2023-04-10 at 19:57 +0800, WANG rui wrote: > We use a jump table to dispatch cases for short data lengths, and for long data > lengths, we use unaligned memory access instruction to process the first and > last 8 bytes. The data in the middle is processed at an aligned destination > address. Regarding these functions: we have -ffreestanding which is preventing the compiler from optimizing for e.g. "memcpy(a, b, 8);" into a simple ld.d/st.d pair. A explicit compiler built-in usage like #define memcpy(a, b, c) __builtin_memcpy(a, b, c) would allow the compiler to do such kind of optimization. Will this improve the performance? > > We have tested micro-bench[1] on a Loongson-3C5000 16-core machine (2.2GHz): > > 1. memset > > > length | src offset | dst offset | speed before | speed after | > > % | > > --------|------------|------------|--------------|-------------|---- > > -----| > > 8 | 0 | 0 | 696.191 | 1518.785 | > > 118.16% | > > 8 | 0 | 1 | 696.325 | 1518.937 | > > 118.14% | > > 50 | 0 | 0 | 969.976 | 8053.902 | > > 730.32% | > > 50 | 0 | 1 | 970.034 | 8058.475 | > > 730.74% | > > 300 | 0 | 0 | 5876.612 | 16544.703 | > > 181.53% | > > 300 | 0 | 1 | 5030.849 | 16549.011 | > > 228.95% | > > 1200 | 0 | 0 | 11797.077 | 16752.137 | > > 42.00% | > > 1200 | 0 | 1 | 5687.141 | 16645.233 | > > 192.68% | > > 4000 | 0 | 0 | 15723.27 | 16761.557 | > > 6.60% | > > 4000 | 0 | 1 | 5906.114 | 16732.316 | > > 183.30% | > > 8000 | 0 | 0 | 16751.403 | 16770.002 | > > 0.11% | > > 8000 | 0 | 1 | 5995.449 | 16754.07 | > > 179.45% | > > 2. memcpy > > > length | src offset | dst offset | speed before | speed after | > > % | > > --------|------------|------------|--------------|-------------|---- > > -----| > > 8 | 0 | 0 | 696.2 | 1670.605 | > > 139.96% | > > 8 | 0 | 1 | 696.325 | 1671.138 | > > 139.99% | > > 50 | 0 | 0 | 969.974 | 8724.999 | > > 799.51% | > > 50 | 0 | 1 | 970.032 | 8730.138 | > > 799.98% | > > 300 | 0 | 0 | 5564.662 | 16272.652 | > > 192.43% | > > 300 | 0 | 1 | 4670.436 | 14972.842 | > > 220.59% | > > 1200 | 0 | 0 | 10740.23 | 16751.728 | > > 55.97% | > > 1200 | 0 | 1 | 5027.741 | 14874.564 | > > 195.85% | > > 4000 | 0 | 0 | 15122.367 | 16737.642 | > > 10.68% | > > 4000 | 0 | 1 | 5536.918 | 14890.397 | > > 168.93% | > > 8000 | 0 | 0 | 16505.453 | 16553.543 | > > 0.29% | > > 8000 | 0 | 1 | 5821.619 | 14841.804 | > > 154.94% | > > 3. memmove > > > length | src offset | dst offset | speed before | speed after | > > % | > > --------|------------|------------|--------------|-------------|---- > > -----| > > 8 | 0 | 0 | 982.693 | 1670.568 | > > 70.00% | > > 8 | 0 | 1 | 983.023 | 1671.174 | > > 70.00% | > > 50 | 0 | 0 | 1230.87 | 8727.625 | > > 609.06% | > > 50 | 0 | 1 | 1232.515 | 8730.138 | > > 608.32% | > > 300 | 0 | 0 | 6490.375 | 16296.993 | > > 151.09% | > > 300 | 0 | 1 | 4282.687 | 14972.842 | > > 249.61% | > > 1200 | 0 | 0 | 11742.755 | 16752.546 | > > 42.66% | > > 1200 | 0 | 1 | 5039.338 | 14872.951 | > > 195.14% | > > 4000 | 0 | 0 | 15467.786 | 16737.09 | > > 8.21% | > > 4000 | 0 | 1 | 5009.905 | 14890.542 | > > 197.22% | > > 8000 | 0 | 0 | 16489.664 | 16553.273 | > > 0.39% | > > 8000 | 0 | 1 | 5823.786 | 14858.646 | > > 155.14% | > > * speed: MB/s > * length: byte > > [1] https://github.com/heiher/mem-bench > > Signed-off-by: WANG rui <wangrui@loongson.cn> > --- > arch/loongarch/lib/clear_user.S | 137 +++++++++++++++-- > arch/loongarch/lib/copy_user.S | 251 +++++++++++++++++++++++++------ > - > arch/loongarch/lib/memcpy.S | 147 +++++++++++++++---- > arch/loongarch/lib/memmove.S | 120 ++++++++------- > arch/loongarch/lib/memset.S | 117 ++++++++++++--- > 5 files changed, 605 insertions(+), 167 deletions(-) > > diff --git a/arch/loongarch/lib/clear_user.S > b/arch/loongarch/lib/clear_user.S > index 2dc48e61a2c8..02f112b265cd 100644 > --- a/arch/loongarch/lib/clear_user.S > +++ b/arch/loongarch/lib/clear_user.S > @@ -13,7 +13,14 @@ > > .irp to, 0, 1, 2, 3, 4, 5, 6, 7 > .L_fixup_handle_\to\(): > - addi.d a0, a1, (\to) * (-8) > + sub.d a0, a2, a0 > + addi.d a0, a0, (\to) * (-8) > + jr ra > +.endr > + > +.irp to, 0, 2, 4 > +.L_fixup_handle_s\to\(): > + addi.d a0, a1, -\to > jr ra > .endr > > @@ -44,7 +51,7 @@ SYM_FUNC_START(__clear_user_generic) > 2: move a0, a1 > jr ra > > - _asm_extable 1b, .L_fixup_handle_0 > + _asm_extable 1b, .L_fixup_handle_s0 > SYM_FUNC_END(__clear_user_generic) > > /* > @@ -54,12 +61,22 @@ SYM_FUNC_END(__clear_user_generic) > * a1: size > */ > SYM_FUNC_START(__clear_user_fast) > - beqz a1, 10f > + sltui t0, a1, 9 > + bnez t0, .Lsmall > > - ori a2, zero, 64 > - blt a1, a2, 9f > + add.d a2, a0, a1 > +0: st.d zero, a0, 0 > + > + /* align up address */ > + andi t1, a0, 7 > + sub.d a0, a0, t1 > + addi.d a0, a0, 8 > + > + addi.d a3, a2, -64 > + bgeu a0, a3, .Llt64 > > /* set 64 bytes at a time */ > +.Lloop64: > 1: st.d zero, a0, 0 > 2: st.d zero, a0, 8 > 3: st.d zero, a0, 16 > @@ -68,24 +85,95 @@ SYM_FUNC_START(__clear_user_fast) > 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 > + bltu a0, a3, .Lloop64 > > /* set the remaining bytes */ > -9: st.b zero, a0, 0 > - addi.d a0, a0, 1 > - addi.d a1, a1, -1 > - bgt a1, zero, 9b > +.Llt64: > + addi.d a3, a2, -32 > + bgeu a0, a3, .Llt32 > +9: st.d zero, a0, 0 > +10: st.d zero, a0, 8 > +11: st.d zero, a0, 16 > +12: st.d zero, a0, 24 > + addi.d a0, a0, 32 > + > +.Llt32: > + addi.d a3, a2, -16 > + bgeu a0, a3, .Llt16 > +13: st.d zero, a0, 0 > +14: st.d zero, a0, 8 > + addi.d a0, a0, 16 > + > +.Llt16: > + addi.d a3, a2, -8 > + bgeu a0, a3, .Llt8 > +15: st.d zero, a0, 0 > + > +.Llt8: > +16: st.d zero, a2, -8 > > /* return */ > -10: move a0, a1 > + move a0, zero > + jr ra > + > + .align 4 > +.Lsmall: > + pcaddi t0, 4 > + slli.d a2, a1, 4 > + add.d t0, t0, a2 > + jr t0 > + > + .align 4 > + move a0, zero > + jr ra > + > + .align 4 > +17: st.b zero, a0, 0 > + move a0, zero > + jr ra > + > + .align 4 > +18: st.h zero, a0, 0 > + move a0, zero > + jr ra > + > + .align 4 > +19: st.h zero, a0, 0 > +20: st.b zero, a0, 2 > + move a0, zero > + jr ra > + > + .align 4 > +21: st.w zero, a0, 0 > + move a0, zero > + jr ra > + > + .align 4 > +22: st.w zero, a0, 0 > +23: st.b zero, a0, 4 > + move a0, zero > + jr ra > + > + .align 4 > +24: st.w zero, a0, 0 > +25: st.h zero, a0, 4 > + move a0, zero > + jr ra > + > + .align 4 > +26: st.w zero, a0, 0 > +27: st.w zero, a0, 3 > + move a0, zero > + jr ra > + > + .align 4 > +28: st.d zero, a0, 0 > + move a0, zero > jr ra > > /* fixup and ex_table */ > + _asm_extable 0b, .L_fixup_handle_0 > _asm_extable 1b, .L_fixup_handle_0 > _asm_extable 2b, .L_fixup_handle_1 > _asm_extable 3b, .L_fixup_handle_2 > @@ -95,4 +183,23 @@ SYM_FUNC_START(__clear_user_fast) > _asm_extable 7b, .L_fixup_handle_6 > _asm_extable 8b, .L_fixup_handle_7 > _asm_extable 9b, .L_fixup_handle_0 > + _asm_extable 10b, .L_fixup_handle_1 > + _asm_extable 11b, .L_fixup_handle_2 > + _asm_extable 12b, .L_fixup_handle_3 > + _asm_extable 13b, .L_fixup_handle_0 > + _asm_extable 14b, .L_fixup_handle_1 > + _asm_extable 15b, .L_fixup_handle_0 > + _asm_extable 16b, .L_fixup_handle_1 > + _asm_extable 17b, .L_fixup_handle_s0 > + _asm_extable 18b, .L_fixup_handle_s0 > + _asm_extable 19b, .L_fixup_handle_s0 > + _asm_extable 20b, .L_fixup_handle_s2 > + _asm_extable 21b, .L_fixup_handle_s0 > + _asm_extable 22b, .L_fixup_handle_s0 > + _asm_extable 23b, .L_fixup_handle_s4 > + _asm_extable 24b, .L_fixup_handle_s0 > + _asm_extable 25b, .L_fixup_handle_s4 > + _asm_extable 26b, .L_fixup_handle_s0 > + _asm_extable 27b, .L_fixup_handle_s4 > + _asm_extable 28b, .L_fixup_handle_s0 > SYM_FUNC_END(__clear_user_fast) > diff --git a/arch/loongarch/lib/copy_user.S > b/arch/loongarch/lib/copy_user.S > index 55ac6020a1ad..b21f6d5d38f5 100644 > --- a/arch/loongarch/lib/copy_user.S > +++ b/arch/loongarch/lib/copy_user.S > @@ -13,7 +13,14 @@ > > .irp to, 0, 1, 2, 3, 4, 5, 6, 7 > .L_fixup_handle_\to\(): > - addi.d a0, a2, (\to) * (-8) > + sub.d a0, a2, a0 > + addi.d a0, a0, (\to) * (-8) > + jr ra > +.endr > + > +.irp to, 0, 2, 4 > +.L_fixup_handle_s\to\(): > + addi.d a0, a2, -\to > jr ra > .endr > > @@ -47,8 +54,8 @@ SYM_FUNC_START(__copy_user_generic) > 3: move a0, a2 > jr ra > > - _asm_extable 1b, .L_fixup_handle_0 > - _asm_extable 2b, .L_fixup_handle_0 > + _asm_extable 1b, .L_fixup_handle_s0 > + _asm_extable 2b, .L_fixup_handle_s0 > SYM_FUNC_END(__copy_user_generic) > > /* > @@ -59,65 +66,209 @@ SYM_FUNC_END(__copy_user_generic) > * a2: n > */ > SYM_FUNC_START(__copy_user_fast) > - beqz a2, 19f > + sltui t0, a2, 9 > + bnez t0, .Lsmall > > - ori a3, zero, 64 > - blt a2, a3, 17f > + add.d a3, a1, a2 > + add.d a2, a0, a2 > +0: ld.d t0, a1, 0 > +1: st.d t0, a0, 0 > > - /* copy 64 bytes at a time */ > -1: ld.d t0, a1, 0 > -2: ld.d t1, a1, 8 > -3: ld.d t2, a1, 16 > -4: ld.d t3, a1, 24 > -5: ld.d t4, a1, 32 > -6: ld.d t5, a1, 40 > -7: ld.d t6, a1, 48 > -8: ld.d t7, a1, 56 > -9: st.d t0, a0, 0 > -10: st.d t1, a0, 8 > -11: st.d t2, a0, 16 > -12: st.d t3, a0, 24 > -13: st.d t4, a0, 32 > -14: st.d t5, a0, 40 > -15: st.d t6, a0, 48 > -16: st.d t7, a0, 56 > + /* align up destination address */ > + andi t1, a0, 7 > + sub.d t0, zero, t1 > + addi.d t0, t0, 8 > + add.d a1, a1, t0 > + add.d a0, a0, t0 > > - addi.d a0, a0, 64 > - addi.d a1, a1, 64 > - addi.d a2, a2, -64 > - bge a2, a3, 1b > + addi.d a4, a3, -64 > + bgeu a1, a4, .Llt64 > > - beqz a2, 19f > + /* copy 64 bytes at a time */ > +.Lloop64: > +2: ld.d t0, a1, 0 > +3: ld.d t1, a1, 8 > +4: ld.d t2, a1, 16 > +5: ld.d t3, a1, 24 > +6: ld.d t4, a1, 32 > +7: ld.d t5, a1, 40 > +8: ld.d t6, a1, 48 > +9: ld.d t7, a1, 56 > + addi.d a1, a1, 64 > +10: st.d t0, a0, 0 > +11: st.d t1, a0, 8 > +12: st.d t2, a0, 16 > +13: st.d t3, a0, 24 > +14: st.d t4, a0, 32 > +15: st.d t5, a0, 40 > +16: st.d t6, a0, 48 > +17: st.d t7, a0, 56 > + addi.d a0, a0, 64 > + bltu a1, a4, .Lloop64 > > /* copy the remaining bytes */ > -17: ld.b t0, a1, 0 > -18: st.b t0, a0, 0 > - addi.d a0, a0, 1 > - addi.d a1, a1, 1 > - addi.d a2, a2, -1 > - bgt a2, zero, 17b > +.Llt64: > + addi.d a4, a3, -32 > + bgeu a1, a4, .Llt32 > +18: ld.d t0, a1, 0 > +19: ld.d t1, a1, 8 > +20: ld.d t2, a1, 16 > +21: ld.d t3, a1, 24 > + addi.d a1, a1, 32 > +22: st.d t0, a0, 0 > +23: st.d t1, a0, 8 > +24: st.d t2, a0, 16 > +25: st.d t3, a0, 24 > + addi.d a0, a0, 32 > + > +.Llt32: > + addi.d a4, a3, -16 > + bgeu a1, a4, .Llt16 > +26: ld.d t0, a1, 0 > +27: ld.d t1, a1, 8 > + addi.d a1, a1, 16 > +28: st.d t0, a0, 0 > +29: st.d t1, a0, 8 > + addi.d a0, a0, 16 > + > +.Llt16: > + addi.d a4, a3, -8 > + bgeu a1, a4, .Llt8 > +30: ld.d t0, a1, 0 > +31: st.d t0, a0, 0 > + > +.Llt8: > +32: ld.d t0, a3, -8 > +33: st.d t0, a2, -8 > > /* return */ > -19: move a0, a2 > + move a0, zero > + jr ra > + > + .align 5 > +.Lsmall: > + pcaddi t0, 8 > + slli.d a3, a2, 5 > + add.d t0, t0, a3 > + jr t0 > + > + .align 5 > + move a0, zero > + jr ra > + > + .align 5 > +34: ld.b t0, a1, 0 > +35: st.b t0, a0, 0 > + move a0, zero > + jr ra > + > + .align 5 > +36: ld.h t0, a1, 0 > +37: st.h t0, a0, 0 > + move a0, zero > + jr ra > + > + .align 5 > +38: ld.h t0, a1, 0 > +39: ld.b t1, a1, 2 > +40: st.h t0, a0, 0 > +41: st.b t1, a0, 2 > + move a0, zero > + jr ra > + > + .align 5 > +42: ld.w t0, a1, 0 > +43: st.w t0, a0, 0 > + move a0, zero > + jr ra > + > + .align 5 > +44: ld.w t0, a1, 0 > +45: ld.b t1, a1, 4 > +46: st.w t0, a0, 0 > +47: st.b t1, a0, 4 > + move a0, zero > + jr ra > + > + .align 5 > +48: ld.w t0, a1, 0 > +49: ld.h t1, a1, 4 > +50: st.w t0, a0, 0 > +51: st.h t1, a0, 4 > + move a0, zero > + jr ra > + > + .align 5 > +52: ld.w t0, a1, 0 > +53: ld.w t1, a1, 3 > +54: st.w t0, a0, 0 > +55: st.w t1, a0, 3 > + move a0, zero > + jr ra > + > + .align 5 > +56: ld.d t0, a1, 0 > +57: st.d t0, a0, 0 > + move a0, zero > jr ra > > /* fixup and ex_table */ > + _asm_extable 0b, .L_fixup_handle_0 > _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 2b, .L_fixup_handle_0 > + _asm_extable 3b, .L_fixup_handle_0 > + _asm_extable 4b, .L_fixup_handle_0 > + _asm_extable 5b, .L_fixup_handle_0 > + _asm_extable 6b, .L_fixup_handle_0 > + _asm_extable 7b, .L_fixup_handle_0 > + _asm_extable 8b, .L_fixup_handle_0 > _asm_extable 9b, .L_fixup_handle_0 > - _asm_extable 10b, .L_fixup_handle_1 > - _asm_extable 11b, .L_fixup_handle_2 > - _asm_extable 12b, .L_fixup_handle_3 > - _asm_extable 13b, .L_fixup_handle_4 > - _asm_extable 14b, .L_fixup_handle_5 > - _asm_extable 15b, .L_fixup_handle_6 > - _asm_extable 16b, .L_fixup_handle_7 > - _asm_extable 17b, .L_fixup_handle_0 > + _asm_extable 10b, .L_fixup_handle_0 > + _asm_extable 11b, .L_fixup_handle_1 > + _asm_extable 12b, .L_fixup_handle_2 > + _asm_extable 13b, .L_fixup_handle_3 > + _asm_extable 14b, .L_fixup_handle_4 > + _asm_extable 15b, .L_fixup_handle_5 > + _asm_extable 16b, .L_fixup_handle_6 > + _asm_extable 17b, .L_fixup_handle_7 > _asm_extable 18b, .L_fixup_handle_0 > + _asm_extable 19b, .L_fixup_handle_0 > + _asm_extable 20b, .L_fixup_handle_0 > + _asm_extable 21b, .L_fixup_handle_0 > + _asm_extable 22b, .L_fixup_handle_0 > + _asm_extable 23b, .L_fixup_handle_1 > + _asm_extable 24b, .L_fixup_handle_2 > + _asm_extable 25b, .L_fixup_handle_3 > + _asm_extable 26b, .L_fixup_handle_0 > + _asm_extable 27b, .L_fixup_handle_0 > + _asm_extable 28b, .L_fixup_handle_0 > + _asm_extable 29b, .L_fixup_handle_1 > + _asm_extable 30b, .L_fixup_handle_0 > + _asm_extable 31b, .L_fixup_handle_0 > + _asm_extable 32b, .L_fixup_handle_0 > + _asm_extable 33b, .L_fixup_handle_1 > + _asm_extable 34b, .L_fixup_handle_s0 > + _asm_extable 35b, .L_fixup_handle_s0 > + _asm_extable 36b, .L_fixup_handle_s0 > + _asm_extable 37b, .L_fixup_handle_s0 > + _asm_extable 38b, .L_fixup_handle_s0 > + _asm_extable 39b, .L_fixup_handle_s0 > + _asm_extable 40b, .L_fixup_handle_s0 > + _asm_extable 41b, .L_fixup_handle_s2 > + _asm_extable 42b, .L_fixup_handle_s0 > + _asm_extable 43b, .L_fixup_handle_s0 > + _asm_extable 44b, .L_fixup_handle_s0 > + _asm_extable 45b, .L_fixup_handle_s0 > + _asm_extable 46b, .L_fixup_handle_s0 > + _asm_extable 47b, .L_fixup_handle_s4 > + _asm_extable 48b, .L_fixup_handle_s0 > + _asm_extable 49b, .L_fixup_handle_s0 > + _asm_extable 50b, .L_fixup_handle_s0 > + _asm_extable 51b, .L_fixup_handle_s4 > + _asm_extable 52b, .L_fixup_handle_s0 > + _asm_extable 53b, .L_fixup_handle_s0 > + _asm_extable 54b, .L_fixup_handle_s0 > + _asm_extable 55b, .L_fixup_handle_s4 > + _asm_extable 56b, .L_fixup_handle_s0 > + _asm_extable 57b, .L_fixup_handle_s0 > SYM_FUNC_END(__copy_user_fast) > diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S > index 3b7e1dec7109..39ce6621c704 100644 > --- a/arch/loongarch/lib/memcpy.S > +++ b/arch/loongarch/lib/memcpy.S > @@ -44,6 +44,66 @@ SYM_FUNC_START(__memcpy_generic) > SYM_FUNC_END(__memcpy_generic) > _ASM_NOKPROBE(__memcpy_generic) > > + .align 5 > +SYM_FUNC_START_NOALIGN(__memcpy_small) > + pcaddi t0, 8 > + slli.d a2, a2, 5 > + add.d t0, t0, a2 > + jr t0 > + > + .align 5 > +0: jr ra > + > + .align 5 > +1: ld.b t0, a1, 0 > + st.b t0, a0, 0 > + jr ra > + > + .align 5 > +2: ld.h t0, a1, 0 > + st.h t0, a0, 0 > + jr ra > + > + .align 5 > +3: ld.h t0, a1, 0 > + ld.b t1, a1, 2 > + st.h t0, a0, 0 > + st.b t1, a0, 2 > + jr ra > + > + .align 5 > +4: ld.w t0, a1, 0 > + st.w t0, a0, 0 > + jr ra > + > + .align 5 > +5: ld.w t0, a1, 0 > + ld.b t1, a1, 4 > + st.w t0, a0, 0 > + st.b t1, a0, 4 > + jr ra > + > + .align 5 > +6: ld.w t0, a1, 0 > + ld.h t1, a1, 4 > + st.w t0, a0, 0 > + st.h t1, a0, 4 > + jr ra > + > + .align 5 > +7: ld.w t0, a1, 0 > + ld.w t1, a1, 3 > + st.w t0, a0, 0 > + st.w t1, a0, 3 > + jr ra > + > + .align 5 > +8: ld.d t0, a1, 0 > + st.d t0, a0, 0 > + jr ra > +SYM_FUNC_END(__memcpy_small) > +_ASM_NOKPROBE(__memcpy_small) > + > /* > * void *__memcpy_fast(void *dst, const void *src, size_t n) > * > @@ -52,14 +112,27 @@ _ASM_NOKPROBE(__memcpy_generic) > * a2: n > */ > SYM_FUNC_START(__memcpy_fast) > - move a3, a0 > - beqz a2, 3f > + sltui t0, a2, 9 > + bnez t0, __memcpy_small > + > + add.d a3, a1, a2 > + add.d a2, a0, a2 > + ld.d a6, a1, 0 > + ld.d a7, a3, -8 > + > + /* align up destination address */ > + andi t1, a0, 7 > + sub.d t0, zero, t1 > + addi.d t0, t0, 8 > + add.d a1, a1, t0 > + add.d a5, a0, t0 > > - ori a4, zero, 64 > - blt a2, a4, 2f > + addi.d a4, a3, -64 > + bgeu a1, a4, .Llt64 > > /* copy 64 bytes at a time */ > -1: ld.d t0, a1, 0 > +.Lloop64: > + ld.d t0, a1, 0 > ld.d t1, a1, 8 > ld.d t2, a1, 16 > ld.d t3, a1, 24 > @@ -67,32 +140,54 @@ SYM_FUNC_START(__memcpy_fast) > ld.d t5, a1, 40 > ld.d t6, a1, 48 > ld.d t7, a1, 56 > - st.d t0, a0, 0 > - st.d t1, a0, 8 > - st.d t2, a0, 16 > - st.d t3, a0, 24 > - st.d t4, a0, 32 > - st.d t5, a0, 40 > - st.d t6, a0, 48 > - st.d t7, a0, 56 > - > - addi.d a0, a0, 64 > addi.d a1, a1, 64 > - addi.d a2, a2, -64 > - bge a2, a4, 1b > - > - beqz a2, 3f > + st.d t0, a5, 0 > + st.d t1, a5, 8 > + st.d t2, a5, 16 > + st.d t3, a5, 24 > + st.d t4, a5, 32 > + st.d t5, a5, 40 > + st.d t6, a5, 48 > + st.d t7, a5, 56 > + addi.d a5, a5, 64 > + bltu a1, a4, .Lloop64 > > /* copy the remaining bytes */ > -2: ld.b t0, a1, 0 > - st.b t0, a0, 0 > - addi.d a0, a0, 1 > - addi.d a1, a1, 1 > - addi.d a2, a2, -1 > - bgt a2, zero, 2b > +.Llt64: > + addi.d a4, a3, -32 > + bgeu a1, a4, .Llt32 > + ld.d t0, a1, 0 > + ld.d t1, a1, 8 > + ld.d t2, a1, 16 > + ld.d t3, a1, 24 > + addi.d a1, a1, 32 > + st.d t0, a5, 0 > + st.d t1, a5, 8 > + st.d t2, a5, 16 > + st.d t3, a5, 24 > + addi.d a5, a5, 32 > + > +.Llt32: > + addi.d a4, a3, -16 > + bgeu a1, a4, .Llt16 > + ld.d t0, a1, 0 > + ld.d t1, a1, 8 > + addi.d a1, a1, 16 > + st.d t0, a5, 0 > + st.d t1, a5, 8 > + addi.d a5, a5, 16 > + > +.Llt16: > + addi.d a4, a3, -8 > + bgeu a1, a4, .Llt8 > + ld.d t0, a1, 0 > + st.d t0, a5, 0 > + > +.Llt8: > + st.d a6, a0, 0 > + st.d a7, a2, -8 > > /* return */ > -3: move a0, a3 > jr ra > SYM_FUNC_END(__memcpy_fast) > _ASM_NOKPROBE(__memcpy_fast) > diff --git a/arch/loongarch/lib/memmove.S > b/arch/loongarch/lib/memmove.S > index b796c3d6da05..45b725ba7867 100644 > --- a/arch/loongarch/lib/memmove.S > +++ b/arch/loongarch/lib/memmove.S > @@ -11,23 +11,9 @@ > #include <asm/regdef.h> > > SYM_FUNC_START(memmove) > - blt a0, a1, 1f /* dst < src, memcpy */ > - blt a1, a0, 3f /* src < dst, rmemcpy */ > + blt a0, a1, memcpy /* dst < src, memcpy */ > + blt a1, a0, rmemcpy /* src < dst, rmemcpy */ > jr ra /* dst == src, return */ > - > - /* if (src - dst) < 64, copy 1 byte at a time */ > -1: ori a3, zero, 64 > - sub.d t0, a1, a0 > - blt t0, a3, 2f > - b memcpy > -2: b __memcpy_generic > - > - /* if (dst - src) < 64, copy 1 byte at a time */ > -3: ori a3, zero, 64 > - sub.d t0, a0, a1 > - blt t0, a3, 4f > - b rmemcpy > -4: b __rmemcpy_generic > SYM_FUNC_END(memmove) > _ASM_NOKPROBE(memmove) > > @@ -76,50 +62,80 @@ _ASM_NOKPROBE(__rmemcpy_generic) > * a2: n > */ > SYM_FUNC_START(__rmemcpy_fast) > - move a3, a0 > - beqz a2, 3f > + sltui t0, a2, 9 > + bnez t0, __memcpy_small > > - add.d a0, a0, a2 > - add.d a1, a1, a2 > + add.d a3, a1, a2 > + add.d a2, a0, a2 > + ld.d a6, a1, 0 > + ld.d a7, a3, -8 > + > + /* align up destination address */ > + andi t1, a2, 7 > + sub.d a3, a3, t1 > + sub.d a5, a2, t1 > > - ori a4, zero, 64 > - blt a2, a4, 2f > + addi.d a4, a1, 64 > + bgeu a4, a3, .Llt64 > > /* copy 64 bytes at a time */ > -1: ld.d t0, a1, -8 > - ld.d t1, a1, -16 > - ld.d t2, a1, -24 > - ld.d t3, a1, -32 > - ld.d t4, a1, -40 > - ld.d t5, a1, -48 > - ld.d t6, a1, -56 > - ld.d t7, a1, -64 > - st.d t0, a0, -8 > - st.d t1, a0, -16 > - st.d t2, a0, -24 > - st.d t3, a0, -32 > - st.d t4, a0, -40 > - st.d t5, a0, -48 > - st.d t6, a0, -56 > - st.d t7, a0, -64 > - > - addi.d a0, a0, -64 > - addi.d a1, a1, -64 > - addi.d a2, a2, -64 > - bge a2, a4, 1b > - > - beqz a2, 3f > +.Lloop64: > + ld.d t0, a3, -8 > + ld.d t1, a3, -16 > + ld.d t2, a3, -24 > + ld.d t3, a3, -32 > + ld.d t4, a3, -40 > + ld.d t5, a3, -48 > + ld.d t6, a3, -56 > + ld.d t7, a3, -64 > + addi.d a3, a3, -64 > + st.d t0, a5, -8 > + st.d t1, a5, -16 > + st.d t2, a5, -24 > + st.d t3, a5, -32 > + st.d t4, a5, -40 > + st.d t5, a5, -48 > + st.d t6, a5, -56 > + st.d t7, a5, -64 > + addi.d a5, a5, -64 > + bltu a4, a3, .Lloop64 > > /* copy the remaining bytes */ > -2: ld.b t0, a1, -1 > - st.b t0, a0, -1 > - addi.d a0, a0, -1 > - addi.d a1, a1, -1 > - addi.d a2, a2, -1 > - bgt a2, zero, 2b > +.Llt64: > + addi.d a4, a1, 32 > + bgeu a4, a3, .Llt32 > + ld.d t0, a3, -8 > + ld.d t1, a3, -16 > + ld.d t2, a3, -24 > + ld.d t3, a3, -32 > + addi.d a3, a3, -32 > + st.d t0, a5, -8 > + st.d t1, a5, -16 > + st.d t2, a5, -24 > + st.d t3, a5, -32 > + addi.d a5, a5, -32 > + > +.Llt32: > + addi.d a4, a1, 16 > + bgeu a4, a3, .Llt16 > + ld.d t0, a3, -8 > + ld.d t1, a3, -16 > + addi.d a3, a3, -16 > + st.d t0, a5, -8 > + st.d t1, a5, -16 > + addi.d a5, a5, -16 > + > +.Llt16: > + addi.d a4, a1, 8 > + bgeu a4, a3, .Llt8 > + ld.d t0, a3, -8 > + st.d t0, a5, -8 > + > +.Llt8: > + st.d a6, a0, 0 > + st.d a7, a2, -8 > > /* return */ > -3: move a0, a3 > jr ra > SYM_FUNC_END(__rmemcpy_fast) > _ASM_NOKPROBE(__rmemcpy_fast) > diff --git a/arch/loongarch/lib/memset.S b/arch/loongarch/lib/memset.S > index a9eb732ab2ad..c5836d916736 100644 > --- a/arch/loongarch/lib/memset.S > +++ b/arch/loongarch/lib/memset.S > @@ -56,39 +56,108 @@ _ASM_NOKPROBE(__memset_generic) > * a2: n > */ > SYM_FUNC_START(__memset_fast) > - move a3, a0 > - beqz a2, 3f > - > - ori a4, zero, 64 > - blt a2, a4, 2f > - > /* fill a1 to 64 bits */ > fill_to_64 a1 > > - /* set 64 bytes at a time */ > -1: st.d a1, a0, 0 > - st.d a1, a0, 8 > - st.d a1, a0, 16 > - st.d a1, a0, 24 > - st.d a1, a0, 32 > - st.d a1, a0, 40 > - st.d a1, a0, 48 > - st.d a1, a0, 56 > + sltui t0, a2, 9 > + bnez t0, .Lsmall > > - addi.d a0, a0, 64 > - addi.d a2, a2, -64 > - bge a2, a4, 1b > + add.d a2, a0, a2 > + st.d a1, a0, 0 > > - beqz a2, 3f > + /* align up address */ > + andi t1, a0, 7 > + sub.d a3, a0, t1 > + addi.d a3, a3, 8 > + > + addi.d a4, a2, -64 > + bgeu a3, a4, .Llt64 > + > + /* set 64 bytes at a time */ > +.Lloop64: > + st.d a1, a3, 0 > + st.d a1, a3, 8 > + st.d a1, a3, 16 > + st.d a1, a3, 24 > + st.d a1, a3, 32 > + st.d a1, a3, 40 > + st.d a1, a3, 48 > + st.d a1, a3, 56 > + addi.d a3, a3, 64 > + bltu a3, a4, .Lloop64 > > /* set the remaining bytes */ > -2: st.b a1, a0, 0 > - addi.d a0, a0, 1 > - addi.d a2, a2, -1 > - bgt a2, zero, 2b > +.Llt64: > + addi.d a4, a2, -32 > + bgeu a3, a4, .Llt32 > + st.d a1, a3, 0 > + st.d a1, a3, 8 > + st.d a1, a3, 16 > + st.d a1, a3, 24 > + addi.d a3, a3, 32 > + > +.Llt32: > + addi.d a4, a2, -16 > + bgeu a3, a4, .Llt16 > + st.d a1, a3, 0 > + st.d a1, a3, 8 > + addi.d a3, a3, 16 > + > +.Llt16: > + addi.d a4, a2, -8 > + bgeu a3, a4, .Llt8 > + st.d a1, a3, 0 > + > +.Llt8: > + st.d a1, a2, -8 > > /* return */ > -3: move a0, a3 > + jr ra > + > + .align 4 > +.Lsmall: > + pcaddi t0, 4 > + slli.d a2, a2, 4 > + add.d t0, t0, a2 > + jr t0 > + > + .align 4 > +0: jr ra > + > + .align 4 > +1: st.b a1, a0, 0 > + jr ra > + > + .align 4 > +2: st.h a1, a0, 0 > + jr ra > + > + .align 4 > +3: st.h a1, a0, 0 > + st.b a1, a0, 2 > + jr ra > + > + .align 4 > +4: st.w a1, a0, 0 > + jr ra > + > + .align 4 > +5: st.w a1, a0, 0 > + st.b a1, a0, 4 > + jr ra > + > + .align 4 > +6: st.w a1, a0, 0 > + st.h a1, a0, 4 > + jr ra > + > + .align 4 > +7: st.w a1, a0, 0 > + st.w a1, a0, 3 > + jr ra > + > + .align 4 > +8: st.d a1, a0, 0 > jr ra > SYM_FUNC_END(__memset_fast) > _ASM_NOKPROBE(__memset_fast) -- Xi Ruoyao <xry111@xry111.site> School of Aerospace Science and Technology, Xidian University
On Mon, Apr 10, 2023 at 8:54 PM Xi Ruoyao <xry111@xry111.site> wrote: > Regarding these functions: we have -ffreestanding which is preventing > the compiler from optimizing for e.g. "memcpy(a, b, 8);" into a simple > ld.d/st.d pair. A explicit compiler built-in usage like > > #define memcpy(a, b, c) __builtin_memcpy(a, b, c) > > would allow the compiler to do such kind of optimization. Will this > improve the performance? That's a good question. IIUC, the current compiler generates inefficient code for constant-length memcpy, which may sacrifice performance for compatibility, as not all hardware supports unaligned memory access. We need a runtime CPU feature dispatch mechanism similar to alternatives to improve the compiler. This is indeed a problem that needs to be addressed. Regards, Rui
On Mon, 2023-04-10 at 22:22 +0800, Rui Wang wrote: > On Mon, Apr 10, 2023 at 8:54 PM Xi Ruoyao <xry111@xry111.site> wrote: > > Regarding these functions: we have -ffreestanding which is > > preventing > > the compiler from optimizing for e.g. "memcpy(a, b, 8);" into a > > simple > > ld.d/st.d pair. A explicit compiler built-in usage like > > > > #define memcpy(a, b, c) __builtin_memcpy(a, b, c) > > > > would allow the compiler to do such kind of optimization. Will > > this > > improve the performance? > > That's a good question. IIUC, the current compiler generates > inefficient code for constant-length memcpy, which may sacrifice > performance for compatibility, as not all hardware supports unaligned > memory access. We need a runtime CPU feature dispatch mechanism > similar to alternatives to improve the compiler. This is indeed a > problem that needs to be addressed. Hmm, yep, GCC does not take the advantage of -mstrict-align expanding memcpy etc. I'll add it into my TODO list for GCC 14. -- Xi Ruoyao <xry111@xry111.site> School of Aerospace Science and Technology, Xidian University
On Mon, Apr 10, 2023 at 10:36 PM Xi Ruoyao <xry111@xry111.site> wrote: > > Hmm, yep, GCC does not take the advantage of -mstrict-align expanding > memcpy etc. I'll add it into my TODO list for GCC 14. Great! It looks like you already have some good ideas, and I look forward to hearing your good news. Rui
On Mon, 2023-04-10 at 23:52 +0800, WANG Rui wrote: > On Mon, Apr 10, 2023 at 10:36 PM Xi Ruoyao <xry111@xry111.site> wrote: > > > > Hmm, yep, GCC does not take the advantage of -mstrict-align expanding > > memcpy etc. I'll add it into my TODO list for GCC 14. Technically, it takes the advantage but not very well. It's now https://gcc.gnu.org/PR109465. > Great! It looks like you already have some good ideas, and I look > forward to hearing your good news. > > Rui > -- Xi Ruoyao <xry111@xry111.site> School of Aerospace Science and Technology, Xidian University
On Mon, 2023-04-10 at 19:57 +0800, WANG rui wrote: > + /* align up address */ > + andi t1, a0, 7 > + sub.d a0, a0, t1 bstrins.d a0, zero, 2, 0 Likewise for other aligning operations if the temporary is not used. > + addi.d a0, a0, 8 -- Xi Ruoyao <xry111@xry111.site> School of Aerospace Science and Technology, Xidian University
On Mon, Apr 10, 2023 at 8:20 PM Xi Ruoyao <xry111@xry111.site> wrote: > > On Mon, 2023-04-10 at 19:57 +0800, WANG rui wrote: > > + /* align up address */ > > + andi t1, a0, 7 > > + sub.d a0, a0, t1 > > bstrins.d a0, zero, 2, 0 > > Likewise for other aligning operations if the temporary is not used. I think we're on the same page. I had previously tested this on the user-space version[1], but it's not a performance-critical area. [1] https://github.com/heiher/mem-bench/blob/0083d4e5a82e57939517413da3bcad81e01adbea/memset-int.S#L35-L37 Regards, Rui
On Mon, 2023-04-10 at 22:19 +0800, Rui Wang wrote: > On Mon, Apr 10, 2023 at 8:20 PM Xi Ruoyao <xry111@xry111.site> wrote: > > > > On Mon, 2023-04-10 at 19:57 +0800, WANG rui wrote: > > > + /* align up address */ > > > + andi t1, a0, 7 > > > + sub.d a0, a0, t1 > > > > bstrins.d a0, zero, 2, 0 > > > > Likewise for other aligning operations if the temporary is not used. > > I think we're on the same page. I had previously tested this on the > user-space version[1], but it's not a performance-critical area. The point is "if you can reduce one instruction and one register usage with no harm, why not do it?" :) AFAIK bstrins.d should be available on all 64-bit LoongArch CPUs. -- Xi Ruoyao <xry111@xry111.site> School of Aerospace Science and Technology, Xidian University
On Mon, Apr 10, 2023 at 10:38 PM Xi Ruoyao <xry111@xry111.site> wrote: > > The point is "if you can reduce one instruction and one register usage > with no harm, why not do it?" :) > > AFAIK bstrins.d should be available on all 64-bit LoongArch CPUs. Hmm, I will make the change in the next version. :) Rui
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