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author | WANG Rui <wangrui@loongson.cn> | 2023-05-01 12:19:43 +0300 |
---|---|---|
committer | Huacai Chen <chenhuacai@loongson.cn> | 2023-05-01 12:19:43 +0300 |
commit | 8941e93ca5906fcca87dc74255b58054ec4d7868 (patch) | |
tree | 0bf2893d167c140db544ac0980342f4ec829106e /arch/loongarch/lib/memmove.S | |
parent | 2b3bd32ea3a22ea2d5e591da4ac2c2b1fb17c0e0 (diff) | |
download | linux-8941e93ca5906fcca87dc74255b58054ec4d7868.tar.xz |
LoongArch: Optimize memory ops (memset/memcpy/memmove)
To optimize memset()/memcpy()/memmove() and so on, we use a jump table
to dispatch cases for short data lengths; and for long data lengths, we
split the destination into head part (first 8 bytes), tail part (last 8
bytes) and middle part. The head part and tail part may be at unaligned
addresses, while the middle part is always aligned (the middle part is
allowed to overlap the head/tail part). In this way, the first and last
8 bytes may be unaligned accesses, but we can make sure 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>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/lib/memmove.S')
-rw-r--r-- | arch/loongarch/lib/memmove.S | 120 |
1 files changed, 68 insertions, 52 deletions
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) |