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| author | Archana R <aravind5@in.ibm.com> | 2021-09-19 23:50:02 -0500 |
|---|---|---|
| committer | Lynn Boger <laboger@linux.vnet.ibm.com> | 2021-09-22 16:53:49 +0000 |
| commit | e128749be88278768c50907ca87270b9d5e96eb5 (patch) | |
| tree | 5af50d85547c52753dc76209b48d30496583f0c2 /src/hash | |
| parent | 74ba70be680a9eb9740638b80f36f68baec5b35c (diff) | |
| download | go-e128749be88278768c50907ca87270b9d5e96eb5.tar.gz go-e128749be88278768c50907ca87270b9d5e96eb5.zip | |
hash/crc32: improve performance of ppc64SlicingUpdateBy8 on ppc64le
Reduce the number of instructions in the short loop of
ppc64SlicingUpdateBy8 function by combining MOVWZ and SRD into a SRD
with appropriate parameters performing the same operation and remove
MOVWZ R7,R7 from the loop
This change produces the following improvements on POWER9. None of the
other tests regress. Improvments on other POWERPC platforms similar.
name old time/op new time/op
delta
CRC32/poly=IEEE/size=15/align=0 80.5ns ± 0% 70.6ns ± 0%
-12%
CRC32/poly=IEEE/size=15/align=1 80.5ns ± 0% 70.6ns ± 0%
-12%
CRC32/poly=IEEE/size=512/align=1 151ns ± 0% 139ns ± 0%
-7%
CRC32/poly=IEEE/size=1kB/align=1 167ns ± 0% 155ns ± 0%
-7%
CRC32/poly=Castagnoli/size=15/align=0 80.2ns ± 0% 70.5ns ± 0%
-12%
CRC32/poly=Castagnoli/size=15/align=1 80.2ns ± 0% 70.5ns ± 0%
-12%
CRC32/poly=Castagnoli/size=512/align=1 150ns ± 0% 139ns ± 0%
-7%
CRC32/poly=Castagnoli/size=1kB/align=1 166ns ± 0% 155ns ± 0%
-6%
Change-Id: I424709041c30d1c637b595d0845e3ae78dc3e0a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/350989
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Diffstat (limited to 'src/hash')
| -rw-r--r-- | src/hash/crc32/crc32_ppc64le.s | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/src/hash/crc32/crc32_ppc64le.s b/src/hash/crc32/crc32_ppc64le.s index 10d5dd61db..763d3270f3 100644 --- a/src/hash/crc32/crc32_ppc64le.s +++ b/src/hash/crc32/crc32_ppc64le.s @@ -112,19 +112,17 @@ loop: ANDCC $7,R6,R8 // any leftover bytes BEQ done // none --> done MOVD R8,CTR // byte count - + PCALIGN $16 // align short loop short: MOVBZ 0(R5),R8 // get v MOVBZ R7,R9 // byte(crc) -> R8 BE vs LE? - MOVWZ R7,R14 - SRD $8,R14,R14 // crc>>8 + SRD $8,R7,R14 // crc>>8 XOR R8,R9,R8 // byte(crc)^v -> R8 ADD $1,R5 // ptr to next v SLD $2,R8 // convert index-> bytes ADD R8,R4,R9 // &tab[byte(crc)^v] MOVWZ 0(R9),R10 // tab[byte(crc)^v] XOR R10,R14,R7 // loop crc in R7 - MOVWZ R7,R7 // 32 bits BC 16,0,short done: NOR R7,R7,R7 // ^crc |