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| author | Lynn Boger <laboger@linux.vnet.ibm.com> | 2016-10-05 15:12:05 -0500 |
|---|---|---|
| committer | Michael Munday <munday@ca.ibm.com> | 2016-10-05 22:18:14 +0000 |
| commit | 3107c91e2d390771888df6b47fd6f8fc7a364cd3 (patch) | |
| tree | 0c2a9608cc8ef4ddb1173f4de03983bf32eebb81 /src | |
| parent | ce645534e481368b4ec6141d48eb361422e423b8 (diff) | |
| download | go-3107c91e2d390771888df6b47fd6f8fc7a364cd3.tar.xz | |
runtime: memclr perf improvements on ppc64x
This updates runtime/memclr_ppc64x.s to improve performance,
by unrolling loops for larger clears.
Fixes #17348
benchmark old MB/s new MB/s speedup
BenchmarkMemclr/5-80 199.71 406.63 2.04x
BenchmarkMemclr/16-80 693.66 1817.41 2.62x
BenchmarkMemclr/64-80 2309.35 5793.34 2.51x
BenchmarkMemclr/256-80 5428.18 14765.81 2.72x
BenchmarkMemclr/4096-80 8611.65 27191.94 3.16x
BenchmarkMemclr/65536-80 8736.69 28604.23 3.27x
BenchmarkMemclr/1M-80 9304.94 27600.09 2.97x
BenchmarkMemclr/4M-80 8705.66 27589.64 3.17x
BenchmarkMemclr/8M-80 8575.74 23631.04 2.76x
BenchmarkMemclr/16M-80 8443.10 19240.68 2.28x
BenchmarkMemclr/64M-80 8390.40 9493.04 1.13x
BenchmarkGoMemclr/5-80 263.05 630.37 2.40x
BenchmarkGoMemclr/16-80 904.33 1148.49 1.27x
BenchmarkGoMemclr/64-80 2830.20 8756.70 3.09x
BenchmarkGoMemclr/256-80 6064.59 20299.46 3.35x
Change-Id: Ic76c9183c8b4129ba3df512ca8b0fe6bd424e088
Reviewed-on: https://go-review.googlesource.com/30373
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <munday@ca.ibm.com>
Reviewed-by: David Chase <drchase@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/runtime/memclr_ppc64x.s | 67 |
1 files changed, 49 insertions, 18 deletions
diff --git a/src/runtime/memclr_ppc64x.s b/src/runtime/memclr_ppc64x.s index 442faa25f2..f7375dbee6 100644 --- a/src/runtime/memclr_ppc64x.s +++ b/src/runtime/memclr_ppc64x.s @@ -7,25 +7,56 @@ #include "textflag.h" // void runtime·memclr(void*, uintptr) -TEXT runtime·memclr(SB),NOSPLIT|NOFRAME,$0-16 - MOVD ptr+0(FP), R3 - MOVD n+8(FP), R4 - SRADCC $3, R4, R6 // R6 is the number of words to zero - BEQ bytes +TEXT runtime·memclr(SB), NOSPLIT|NOFRAME, $0-16 + MOVD ptr+0(FP), R3 + MOVD n+8(FP), R4 - SUB $8, R3 - MOVD R6, CTR - MOVDU R0, 8(R3) - BC 25, 0, -1(PC) // bdnz+ $-4 - ADD $8, R3 + // Determine if there are doublewords to clear +check: + ANDCC $7, R4, R5 // R5: leftover bytes to clear + SRAD $3, R4, R6 // R6: double words to clear + CMP R6, $0, CR1 // CR1[EQ] set if no double words -bytes: - ANDCC $7, R4, R7 // R7 is the number of bytes to zero - BEQ done - SUB $1, R3 - MOVD R7, CTR - MOVBU R0, 1(R3) - BC 25, 0, -1(PC) // bdnz+ $-4 + BC 12, 6, nozerolarge // only single bytes + MOVD R6, CTR // R6 = number of double words + SRADCC $2, R6, R7 // 32 byte chunks? + BNE zero32setup -done: + // Clear double words + +zero8: + MOVD R0, 0(R3) // double word + ADD $8, R3 + BC 16, 0, zero8 // dec ctr, br zero8 if ctr not 0 + BR nozerolarge // handle remainder + + // Prepare to clear 32 bytes at a time. + +zero32setup: + DCBTST (R3) // prepare data cache + MOVD R7, CTR // number of 32 byte chunks + +zero32: + MOVD R0, 0(R3) // clear 4 double words + MOVD R0, 8(R3) + MOVD R0, 16(R3) + MOVD R0, 24(R3) + ADD $32, R3 + BC 16, 0, zero32 // dec ctr, br zero32 if ctr not 0 + RLDCLCC $61, R4, $3, R6 // remaining doublewords + BEQ nozerolarge + MOVD R6, CTR // set up the CTR for doublewords + BR zero8 + +nozerolarge: + CMP R5, $0 // any remaining bytes + BC 4, 1, LR // ble lr + +zerotail: + MOVD R5, CTR // set up to clear tail bytes + +zerotailloop: + MOVB R0, 0(R3) // clear single bytes + ADD $1, R3 + BC 16, 0, zerotailloop // dec ctr, br zerotailloop if ctr not 0 RET |