gotosocial/vendor/github.com/zeebo/xxh3/hash128.go

254 lines
6.2 KiB
Go
Raw Normal View History

package xxh3
import (
"math/bits"
)
// Hash128 returns the 128-bit hash of the byte slice.
func Hash128(b []byte) Uint128 {
return hashAny128(*(*str)(ptr(&b)))
}
// HashString128 returns the 128-bit hash of the string slice.
func HashString128(s string) Uint128 {
return hashAny128(*(*str)(ptr(&s)))
}
func hashAny128(s str) (acc u128) {
p, l := s.p, s.l
switch {
case l <= 16:
switch {
case l > 8: // 9-16
const bitflipl = key64_032 ^ key64_040
const bitfliph = key64_048 ^ key64_056
input_lo := readU64(p, 0)
input_hi := readU64(p, ui(l)-8)
m128_h, m128_l := bits.Mul64(input_lo^input_hi^bitflipl, prime64_1)
m128_l += uint64(l-1) << 54
input_hi ^= bitfliph
m128_h += input_hi + uint64(uint32(input_hi))*(prime32_2-1)
m128_l ^= bits.ReverseBytes64(m128_h)
acc.Hi, acc.Lo = bits.Mul64(m128_l, prime64_2)
acc.Hi += m128_h * prime64_2
acc.Lo = xxh3Avalanche(acc.Lo)
acc.Hi = xxh3Avalanche(acc.Hi)
return acc
case l > 3: // 4-8
const bitflip = key64_016 ^ key64_024
input_lo := readU32(p, 0)
input_hi := readU32(p, ui(l)-4)
input_64 := u64(input_lo) + u64(input_hi)<<32
keyed := input_64 ^ bitflip
acc.Hi, acc.Lo = bits.Mul64(keyed, prime64_1+(uint64(l)<<2))
acc.Hi += acc.Lo << 1
acc.Lo ^= acc.Hi >> 3
acc.Lo ^= acc.Lo >> 35
acc.Lo *= 0x9fb21c651e98df25
acc.Lo ^= acc.Lo >> 28
acc.Hi = xxh3Avalanche(acc.Hi)
return acc
case l == 3: // 3
c12 := u64(readU16(p, 0))
c3 := u64(readU8(p, 2))
acc.Lo = c12<<16 + c3 + 3<<8
case l > 1: // 2
c12 := u64(readU16(p, 0))
acc.Lo = c12*(1<<24+1)>>8 + 2<<8
case l == 1: // 1
c1 := u64(readU8(p, 0))
acc.Lo = c1*(1<<24+1<<16+1) + 1<<8
default: // 0
return u128{0x99aa06d3014798d8, 0x6001c324468d497f}
}
acc.Hi = uint64(bits.RotateLeft32(bits.ReverseBytes32(uint32(acc.Lo)), 13))
acc.Lo ^= uint64(key32_000 ^ key32_004)
acc.Hi ^= uint64(key32_008 ^ key32_012)
acc.Lo = xxh64AvalancheSmall(acc.Lo)
acc.Hi = xxh64AvalancheSmall(acc.Hi)
return acc
case l <= 128:
acc.Lo = u64(l) * prime64_1
if l > 32 {
if l > 64 {
if l > 96 {
in8, in7 := readU64(p, ui(l)-8*8), readU64(p, ui(l)-7*8)
i6, i7 := readU64(p, 6*8), readU64(p, 7*8)
acc.Hi += mulFold64(in8^key64_112, in7^key64_120)
acc.Hi ^= i6 + i7
acc.Lo += mulFold64(i6^key64_096, i7^key64_104)
acc.Lo ^= in8 + in7
} // 96
in6, in5 := readU64(p, ui(l)-6*8), readU64(p, ui(l)-5*8)
i4, i5 := readU64(p, 4*8), readU64(p, 5*8)
acc.Hi += mulFold64(in6^key64_080, in5^key64_088)
acc.Hi ^= i4 + i5
acc.Lo += mulFold64(i4^key64_064, i5^key64_072)
acc.Lo ^= in6 + in5
} // 64
in4, in3 := readU64(p, ui(l)-4*8), readU64(p, ui(l)-3*8)
i2, i3 := readU64(p, 2*8), readU64(p, 3*8)
acc.Hi += mulFold64(in4^key64_048, in3^key64_056)
acc.Hi ^= i2 + i3
acc.Lo += mulFold64(i2^key64_032, i3^key64_040)
acc.Lo ^= in4 + in3
} // 32
in2, in1 := readU64(p, ui(l)-2*8), readU64(p, ui(l)-1*8)
i0, i1 := readU64(p, 0*8), readU64(p, 1*8)
acc.Hi += mulFold64(in2^key64_016, in1^key64_024)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^key64_000, i1^key64_008)
acc.Lo ^= in2 + in1
acc.Hi, acc.Lo = (acc.Lo*prime64_1)+(acc.Hi*prime64_4)+(u64(l)*prime64_2), acc.Hi+acc.Lo
acc.Hi = -xxh3Avalanche(acc.Hi)
acc.Lo = xxh3Avalanche(acc.Lo)
return acc
case l <= 240:
acc.Lo = u64(l) * prime64_1
{
i0, i1, i2, i3 := readU64(p, 0*8), readU64(p, 1*8), readU64(p, 2*8), readU64(p, 3*8)
acc.Hi += mulFold64(i2^key64_016, i3^key64_024)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^key64_000, i1^key64_008)
acc.Lo ^= i2 + i3
}
{
i0, i1, i2, i3 := readU64(p, 4*8), readU64(p, 5*8), readU64(p, 6*8), readU64(p, 7*8)
acc.Hi += mulFold64(i2^key64_048, i3^key64_056)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^key64_032, i1^key64_040)
acc.Lo ^= i2 + i3
}
{
i0, i1, i2, i3 := readU64(p, 8*8), readU64(p, 9*8), readU64(p, 10*8), readU64(p, 11*8)
acc.Hi += mulFold64(i2^key64_080, i3^key64_088)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^key64_064, i1^key64_072)
acc.Lo ^= i2 + i3
}
{
i0, i1, i2, i3 := readU64(p, 12*8), readU64(p, 13*8), readU64(p, 14*8), readU64(p, 15*8)
acc.Hi += mulFold64(i2^key64_112, i3^key64_120)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^key64_096, i1^key64_104)
acc.Lo ^= i2 + i3
}
// avalanche
acc.Hi = xxh3Avalanche(acc.Hi)
acc.Lo = xxh3Avalanche(acc.Lo)
// trailing groups after 128
top := ui(l) &^ 31
for i := ui(4 * 32); i < top; i += 32 {
i0, i1, i2, i3 := readU64(p, i+0), readU64(p, i+8), readU64(p, i+16), readU64(p, i+24)
k0, k1, k2, k3 := readU64(key, i-125), readU64(key, i-117), readU64(key, i-109), readU64(key, i-101)
acc.Hi += mulFold64(i2^k2, i3^k3)
acc.Hi ^= i0 + i1
acc.Lo += mulFold64(i0^k0, i1^k1)
acc.Lo ^= i2 + i3
}
// last 32 bytes
{
i0, i1, i2, i3 := readU64(p, ui(l)-32), readU64(p, ui(l)-24), readU64(p, ui(l)-16), readU64(p, ui(l)-8)
acc.Hi += mulFold64(i0^key64_119, i1^key64_127)
acc.Hi ^= i2 + i3
acc.Lo += mulFold64(i2^key64_103, i3^key64_111)
acc.Lo ^= i0 + i1
}
acc.Hi, acc.Lo = (acc.Lo*prime64_1)+(acc.Hi*prime64_4)+(u64(l)*prime64_2), acc.Hi+acc.Lo
acc.Hi = -xxh3Avalanche(acc.Hi)
acc.Lo = xxh3Avalanche(acc.Lo)
return acc
default:
acc.Lo = u64(l) * prime64_1
acc.Hi = ^(u64(l) * prime64_2)
accs := [8]u64{
prime32_3, prime64_1, prime64_2, prime64_3,
prime64_4, prime32_2, prime64_5, prime32_1,
}
if hasAVX512 && l >= avx512Switch {
accumAVX512(&accs, p, key, u64(l))
} else if hasAVX2 {
accumAVX2(&accs, p, key, u64(l))
} else if hasSSE2 {
accumSSE(&accs, p, key, u64(l))
} else {
accumScalar(&accs, p, key, u64(l))
}
// merge accs
acc.Lo += mulFold64(accs[0]^key64_011, accs[1]^key64_019)
acc.Hi += mulFold64(accs[0]^key64_117, accs[1]^key64_125)
acc.Lo += mulFold64(accs[2]^key64_027, accs[3]^key64_035)
acc.Hi += mulFold64(accs[2]^key64_133, accs[3]^key64_141)
acc.Lo += mulFold64(accs[4]^key64_043, accs[5]^key64_051)
acc.Hi += mulFold64(accs[4]^key64_149, accs[5]^key64_157)
acc.Lo += mulFold64(accs[6]^key64_059, accs[7]^key64_067)
acc.Hi += mulFold64(accs[6]^key64_165, accs[7]^key64_173)
acc.Lo = xxh3Avalanche(acc.Lo)
acc.Hi = xxh3Avalanche(acc.Hi)
return acc
}
}