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feat: improve BCE in CH128 computing #3

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Jan 25, 2022
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feat: improve BCE in CH128 computing #3

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97c30f0
chore: use Go 1.17
tdakkota Jan 24, 2022
4eb211a
feat: improve BCE in Murmur computing
tdakkota Jan 24, 2022
6c6a5e4
feat: improve BCE in CH128 computing
tdakkota Jan 24, 2022
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48 changes: 32 additions & 16 deletions ch_128.go
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ func chMurmur(s []byte, seed U128) U128 {
c := uint64(0)
d := uint64(0)
l := length - 16
if l <= 0 { // length <= 16
if len(s) <= 16 { // length <= 16
a = shiftMix(a*k1) * k1
c = b*k1 + ch0to16(s, length)

Expand All @@ -25,18 +25,31 @@ func chMurmur(s []byte, seed U128) U128 {
d = ch16(b+uint64(length), c+binary.LittleEndian.Uint64(s[length-16:]))
a += d

for {
a ^= shiftMix(binary.LittleEndian.Uint64(s)*k1) * k1
{
a ^= shiftMix(binary.LittleEndian.Uint64(s[0:8:8])*k1) * k1
a *= k1
b ^= a
c ^= shiftMix(binary.LittleEndian.Uint64(s[8:])*k1) * k1
c ^= shiftMix(binary.LittleEndian.Uint64(s[8:8+8:8+8])*k1) * k1
c *= k1
d ^= c
s = s[16:]
l -= 16
}

if l <= 0 {
break
if l > 0 {
for len(s) >= 16 {
a ^= shiftMix(binary.LittleEndian.Uint64(s[0:8:8])*k1) * k1
a *= k1
b ^= a
c ^= shiftMix(binary.LittleEndian.Uint64(s[8:8+8:8+8])*k1) * k1
c *= k1
d ^= c
s = s[16:]
l -= 16

if l <= 0 {
break
}
}
}
}
Expand All @@ -49,8 +62,8 @@ func chMurmur(s []byte, seed U128) U128 {
func CH128(s []byte) U128 {
if len(s) >= 16 {
return CH128Seed(s[16:], U128{
Low: binary.LittleEndian.Uint64(s) ^ k3,
High: binary.LittleEndian.Uint64(s[8:]),
Low: binary.LittleEndian.Uint64(s[0:8:8]) ^ k3,
High: binary.LittleEndian.Uint64(s[8 : 8+8 : 8+8]),
})
}
if len(s) >= 8 {
Expand Down Expand Up @@ -79,17 +92,20 @@ func CH128Seed(s []byte, seed U128) U128 {
y := seed.High
z := uint64(len(s)) * k1

v.Low = rot64(y^k1, 49)*k1 + binary.LittleEndian.Uint64(s)
v.High = rot64(v.Low, 42)*k1 + binary.LittleEndian.Uint64(s[8:])
w.Low = rot64(y+z, 35)*k1 + x
w.High = rot64(x+binary.LittleEndian.Uint64(s[88:]), 53) * k1
{
subSlice := (*[96]byte)(s[0:])
v.Low = rot64(y^k1, 49)*k1 + binary.LittleEndian.Uint64(subSlice[0:])
v.High = rot64(v.Low, 42)*k1 + binary.LittleEndian.Uint64(subSlice[8:])
w.Low = rot64(y+z, 35)*k1 + x
w.High = rot64(x+binary.LittleEndian.Uint64(subSlice[88:]), 53) * k1
}

// This is the same inner loop as CH64(), manually unrolled.
for len(s) >= 128 {
// Roll 1.
{
x = rot64(x+y+v.Low+binary.LittleEndian.Uint64(s[16:]), 37) * k1
y = rot64(y+v.High+binary.LittleEndian.Uint64(s[48:]), 42) * k1
x = rot64(x+y+v.Low+binary.LittleEndian.Uint64(s[16:16+8:16+8]), 37) * k1
y = rot64(y+v.High+binary.LittleEndian.Uint64(s[48:48+8:48+8]), 42) * k1

x ^= w.High
y ^= v.Low
Expand All @@ -103,8 +119,8 @@ func CH128Seed(s []byte, seed U128) U128 {
// Roll 2.
{
const offset = 64
x = rot64(x+y+v.Low+binary.LittleEndian.Uint64(s[offset+16:]), 37) * k1
y = rot64(y+v.High+binary.LittleEndian.Uint64(s[offset+48:]), 42) * k1
x = rot64(x+y+v.Low+binary.LittleEndian.Uint64(s[offset+16:offset+16+8:offset+16+8]), 37) * k1
y = rot64(y+v.High+binary.LittleEndian.Uint64(s[offset+48:offset+48+8:offset+48+8]), 42) * k1
x ^= w.High
y ^= v.Low

Expand Down
2 changes: 1 addition & 1 deletion go.mod
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Original file line number Diff line number Diff line change
@@ -1,3 +1,3 @@
module github.com/go-faster/city

go 1.16
go 1.17