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Source file src/github.com/zeebo/xxh3/hash128_seed.go

Documentation: github.com/zeebo/xxh3

     1  package xxh3
     2  
     3  import (
     4  	"math/bits"
     5  )
     6  
     7  // Hash128Seed returns the 128-bit hash of the byte slice.
     8  func Hash128Seed(b []byte, seed uint64) Uint128 {
     9  	return hashAny128Seed(*(*str)(ptr(&b)), seed)
    10  }
    11  
    12  // HashString128Seed returns the 128-bit hash of the string slice.
    13  func HashString128Seed(s string, seed uint64) Uint128 {
    14  	return hashAny128Seed(*(*str)(ptr(&s)), seed)
    15  }
    16  
    17  func hashAny128Seed(s str, seed uint64) (acc u128) {
    18  	p, l := s.p, s.l
    19  
    20  	switch {
    21  	case l <= 16:
    22  		switch {
    23  		case l > 8: // 9-16
    24  			bitflipl := (key64_032 ^ key64_040) - seed
    25  			bitfliph := (key64_048 ^ key64_056) + seed
    26  
    27  			input_lo := readU64(p, 0)
    28  			input_hi := readU64(p, ui(l)-8)
    29  
    30  			m128_h, m128_l := bits.Mul64(input_lo^input_hi^bitflipl, prime64_1)
    31  
    32  			m128_l += uint64(l-1) << 54
    33  			input_hi ^= bitfliph
    34  
    35  			m128_h += input_hi + uint64(uint32(input_hi))*(prime32_2-1)
    36  
    37  			m128_l ^= bits.ReverseBytes64(m128_h)
    38  
    39  			acc.Hi, acc.Lo = bits.Mul64(m128_l, prime64_2)
    40  			acc.Hi += m128_h * prime64_2
    41  
    42  			acc.Lo = xxh3Avalanche(acc.Lo)
    43  			acc.Hi = xxh3Avalanche(acc.Hi)
    44  
    45  			return acc
    46  
    47  		case l > 3: // 4-8
    48  			seed ^= u64(bits.ReverseBytes32(u32(seed))) << 32
    49  			bitflip := (key64_016 ^ key64_024) + seed
    50  			input_lo := readU32(p, 0)
    51  			input_hi := readU32(p, ui(l)-4)
    52  			input_64 := u64(input_lo) + u64(input_hi)<<32
    53  			keyed := input_64 ^ bitflip
    54  
    55  			acc.Hi, acc.Lo = bits.Mul64(keyed, prime64_1+(uint64(l)<<2))
    56  
    57  			acc.Hi += acc.Lo << 1
    58  			acc.Lo ^= acc.Hi >> 3
    59  
    60  			acc.Lo ^= acc.Lo >> 35
    61  			acc.Lo *= 0x9fb21c651e98df25
    62  			acc.Lo ^= acc.Lo >> 28
    63  			acc.Hi = xxh3Avalanche(acc.Hi)
    64  
    65  			return acc
    66  
    67  		case l == 3: // 3
    68  			c12 := u64(readU16(p, 0))
    69  			c3 := u64(readU8(p, 2))
    70  			acc.Lo = c12<<16 + c3 + 3<<8
    71  
    72  		case l > 1: // 2
    73  			c12 := u64(readU16(p, 0))
    74  			acc.Lo = c12*(1<<24+1)>>8 + 2<<8
    75  
    76  		case l == 1: // 1
    77  			c1 := u64(readU8(p, 0))
    78  			acc.Lo = c1*(1<<24+1<<16+1) + 1<<8
    79  
    80  		default: // 0
    81  			bitflipl := key64_064 ^ key64_072 ^ seed
    82  			bitfliph := key64_080 ^ key64_088 ^ seed
    83  			return u128{Lo: xxh64AvalancheFull(bitflipl), Hi: xxh64AvalancheFull(bitfliph)}
    84  		}
    85  
    86  		acc.Hi = uint64(bits.RotateLeft32(bits.ReverseBytes32(uint32(acc.Lo)), 13))
    87  		acc.Lo ^= uint64(key32_000^key32_004) + seed
    88  		acc.Hi ^= uint64(key32_008^key32_012) - seed
    89  
    90  		acc.Lo = xxh64AvalancheFull(acc.Lo)
    91  		acc.Hi = xxh64AvalancheFull(acc.Hi)
    92  
    93  		return acc
    94  
    95  	case l <= 128:
    96  		acc.Lo = u64(l) * prime64_1
    97  
    98  		if l > 32 {
    99  			if l > 64 {
   100  				if l > 96 {
   101  					in8, in7 := readU64(p, ui(l)-8*8), readU64(p, ui(l)-7*8)
   102  					i6, i7 := readU64(p, 6*8), readU64(p, 7*8)
   103  
   104  					acc.Hi += mulFold64(in8^(key64_112+seed), in7^(key64_120-seed))
   105  					acc.Hi ^= i6 + i7
   106  					acc.Lo += mulFold64(i6^(key64_096+seed), i7^(key64_104-seed))
   107  					acc.Lo ^= in8 + in7
   108  
   109  				} // 96
   110  
   111  				in6, in5 := readU64(p, ui(l)-6*8), readU64(p, ui(l)-5*8)
   112  				i4, i5 := readU64(p, 4*8), readU64(p, 5*8)
   113  
   114  				acc.Hi += mulFold64(in6^(key64_080+seed), in5^(key64_088-seed))
   115  				acc.Hi ^= i4 + i5
   116  				acc.Lo += mulFold64(i4^(key64_064+seed), i5^(key64_072-seed))
   117  				acc.Lo ^= in6 + in5
   118  
   119  			} // 64
   120  
   121  			in4, in3 := readU64(p, ui(l)-4*8), readU64(p, ui(l)-3*8)
   122  			i2, i3 := readU64(p, 2*8), readU64(p, 3*8)
   123  
   124  			acc.Hi += mulFold64(in4^(key64_048+seed), in3^(key64_056-seed))
   125  			acc.Hi ^= i2 + i3
   126  			acc.Lo += mulFold64(i2^(key64_032+seed), i3^(key64_040-seed))
   127  			acc.Lo ^= in4 + in3
   128  
   129  		} // 32
   130  
   131  		in2, in1 := readU64(p, ui(l)-2*8), readU64(p, ui(l)-1*8)
   132  		i0, i1 := readU64(p, 0*8), readU64(p, 1*8)
   133  
   134  		acc.Hi += mulFold64(in2^(key64_016+seed), in1^(key64_024-seed))
   135  		acc.Hi ^= i0 + i1
   136  		acc.Lo += mulFold64(i0^(key64_000+seed), i1^(key64_008-seed))
   137  		acc.Lo ^= in2 + in1
   138  
   139  		acc.Hi, acc.Lo = (acc.Lo*prime64_1)+(acc.Hi*prime64_4)+((u64(l)-seed)*prime64_2), acc.Hi+acc.Lo
   140  
   141  		acc.Hi = -xxh3Avalanche(acc.Hi)
   142  		acc.Lo = xxh3Avalanche(acc.Lo)
   143  
   144  		return acc
   145  
   146  	case l <= 240:
   147  		acc.Lo = u64(l) * prime64_1
   148  
   149  		{
   150  			i0, i1, i2, i3 := readU64(p, 0*8), readU64(p, 1*8), readU64(p, 2*8), readU64(p, 3*8)
   151  
   152  			acc.Hi += mulFold64(i2^(key64_016+seed), i3^(key64_024-seed))
   153  			acc.Hi ^= i0 + i1
   154  			acc.Lo += mulFold64(i0^(key64_000+seed), i1^(key64_008-seed))
   155  			acc.Lo ^= i2 + i3
   156  		}
   157  
   158  		{
   159  			i0, i1, i2, i3 := readU64(p, 4*8), readU64(p, 5*8), readU64(p, 6*8), readU64(p, 7*8)
   160  
   161  			acc.Hi += mulFold64(i2^(key64_048+seed), i3^(key64_056-seed))
   162  			acc.Hi ^= i0 + i1
   163  			acc.Lo += mulFold64(i0^(key64_032+seed), i1^(key64_040-seed))
   164  			acc.Lo ^= i2 + i3
   165  		}
   166  
   167  		{
   168  			i0, i1, i2, i3 := readU64(p, 8*8), readU64(p, 9*8), readU64(p, 10*8), readU64(p, 11*8)
   169  
   170  			acc.Hi += mulFold64(i2^(key64_080+seed), i3^(key64_088-seed))
   171  			acc.Hi ^= i0 + i1
   172  			acc.Lo += mulFold64(i0^(key64_064+seed), i1^(key64_072-seed))
   173  			acc.Lo ^= i2 + i3
   174  		}
   175  
   176  		{
   177  			i0, i1, i2, i3 := readU64(p, 12*8), readU64(p, 13*8), readU64(p, 14*8), readU64(p, 15*8)
   178  
   179  			acc.Hi += mulFold64(i2^(key64_112+seed), i3^(key64_120-seed))
   180  			acc.Hi ^= i0 + i1
   181  			acc.Lo += mulFold64(i0^(key64_096+seed), i1^(key64_104-seed))
   182  			acc.Lo ^= i2 + i3
   183  		}
   184  
   185  		// avalanche
   186  		acc.Hi = xxh3Avalanche(acc.Hi)
   187  		acc.Lo = xxh3Avalanche(acc.Lo)
   188  
   189  		// trailing groups after 128
   190  		top := ui(l) &^ 31
   191  		for i := ui(4 * 32); i < top; i += 32 {
   192  			i0, i1, i2, i3 := readU64(p, i+0), readU64(p, i+8), readU64(p, i+16), readU64(p, i+24)
   193  			k0, k1, k2, k3 := readU64(key, i-125)+seed, readU64(key, i-117)-seed, readU64(key, i-109)+seed, readU64(key, i-101)-seed
   194  
   195  			acc.Hi += mulFold64(i2^k2, i3^k3)
   196  			acc.Hi ^= i0 + i1
   197  			acc.Lo += mulFold64(i0^k0, i1^k1)
   198  			acc.Lo ^= i2 + i3
   199  		}
   200  
   201  		// last 32 bytes
   202  		{
   203  			i0, i1, i2, i3 := readU64(p, ui(l)-32), readU64(p, ui(l)-24), readU64(p, ui(l)-16), readU64(p, ui(l)-8)
   204  
   205  			seed := 0 - seed
   206  			acc.Hi += mulFold64(i0^(key64_119+seed), i1^(key64_127-seed))
   207  			acc.Hi ^= i2 + i3
   208  			acc.Lo += mulFold64(i2^(key64_103+seed), i3^(key64_111-seed))
   209  			acc.Lo ^= i0 + i1
   210  		}
   211  
   212  		acc.Hi, acc.Lo = (acc.Lo*prime64_1)+(acc.Hi*prime64_4)+((u64(l)-seed)*prime64_2), acc.Hi+acc.Lo
   213  
   214  		acc.Hi = -xxh3Avalanche(acc.Hi)
   215  		acc.Lo = xxh3Avalanche(acc.Lo)
   216  
   217  		return acc
   218  
   219  	default:
   220  		acc.Lo = u64(l) * prime64_1
   221  		acc.Hi = ^(u64(l) * prime64_2)
   222  
   223  		secret := key
   224  		if seed != 0 {
   225  			secret = ptr(&[secretSize]byte{})
   226  			initSecret(secret, seed)
   227  		}
   228  
   229  		accs := [8]u64{
   230  			prime32_3, prime64_1, prime64_2, prime64_3,
   231  			prime64_4, prime32_2, prime64_5, prime32_1,
   232  		}
   233  
   234  		if hasAVX512 && l >= avx512Switch {
   235  			accumAVX512(&accs, p, secret, u64(l))
   236  		} else if hasAVX2 {
   237  			accumAVX2(&accs, p, secret, u64(l))
   238  		} else if hasSSE2 {
   239  			accumSSE(&accs, p, secret, u64(l))
   240  		} else {
   241  			accumScalar(&accs, p, secret, u64(l))
   242  		}
   243  
   244  		// merge accs
   245  		const hi_off = 117 - 11
   246  
   247  		acc.Lo += mulFold64(accs[0]^readU64(secret, 11), accs[1]^readU64(secret, 19))
   248  		acc.Hi += mulFold64(accs[0]^readU64(secret, 11+hi_off), accs[1]^readU64(secret, 19+hi_off))
   249  
   250  		acc.Lo += mulFold64(accs[2]^readU64(secret, 27), accs[3]^readU64(secret, 35))
   251  		acc.Hi += mulFold64(accs[2]^readU64(secret, 27+hi_off), accs[3]^readU64(secret, 35+hi_off))
   252  
   253  		acc.Lo += mulFold64(accs[4]^readU64(secret, 43), accs[5]^readU64(secret, 51))
   254  		acc.Hi += mulFold64(accs[4]^readU64(secret, 43+hi_off), accs[5]^readU64(secret, 51+hi_off))
   255  
   256  		acc.Lo += mulFold64(accs[6]^readU64(secret, 59), accs[7]^readU64(secret, 67))
   257  		acc.Hi += mulFold64(accs[6]^readU64(secret, 59+hi_off), accs[7]^readU64(secret, 67+hi_off))
   258  
   259  		acc.Lo = xxh3Avalanche(acc.Lo)
   260  		acc.Hi = xxh3Avalanche(acc.Hi)
   261  
   262  		return acc
   263  	}
   264  }
   265  

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