diff options
Diffstat (limited to 'libgo/go/runtime/hash64.go')
| -rw-r--r-- | libgo/go/runtime/hash64.go | 139 |
1 files changed, 62 insertions, 77 deletions
diff --git a/libgo/go/runtime/hash64.go b/libgo/go/runtime/hash64.go index 704bbe6..96ed90b 100644 --- a/libgo/go/runtime/hash64.go +++ b/libgo/go/runtime/hash64.go @@ -3,113 +3,98 @@ // license that can be found in the LICENSE file. // Hashing algorithm inspired by -// xxhash: https://code.google.com/p/xxhash/ -// cityhash: https://code.google.com/p/cityhash/ +// wyhash: https://github.com/wangyi-fudan/wyhash -// +build amd64 arm64 mips64 mips64le ppc64 ppc64le riscv64 s390x wasm alpha amd64p32 arm64be ia64 mips64p32 mips64p32le sparc64 +//go:build amd64 || arm64 || mips64 || mips64le || ppc64 || ppc64le || riscv64 || s390x || wasm || alpha || arm64be || ia64 || sparc64 +// +build amd64 arm64 mips64 mips64le ppc64 ppc64le riscv64 s390x wasm alpha arm64be ia64 sparc64 package runtime -import "unsafe" +import ( + "runtime/internal/math" + "unsafe" +) // For gccgo, use go:linkname to export compiler-called functions. // //go:linkname memhash const ( - // Constants for multiplication: four random odd 64-bit numbers. - m1 = 16877499708836156737 - m2 = 2820277070424839065 - m3 = 9497967016996688599 - m4 = 15839092249703872147 + m1 = 0xa0761d6478bd642f + m2 = 0xe7037ed1a0b428db + m3 = 0x8ebc6af09c88c6e3 + m4 = 0x589965cc75374cc3 + m5 = 0x1d8e4e27c47d124f ) func memhash(p unsafe.Pointer, seed, s uintptr) uintptr { if (GOARCH == "amd64" || GOARCH == "arm64") && useAeshash { return aeshash(p, seed, s) } - h := uint64(seed + s*hashkey[0]) -tail: + var a, b uintptr + seed ^= hashkey[0] ^ m1 switch { case s == 0: + return seed case s < 4: - h ^= uint64(*(*byte)(p)) - h ^= uint64(*(*byte)(add(p, s>>1))) << 8 - h ^= uint64(*(*byte)(add(p, s-1))) << 16 - h = rotl_31(h*m1) * m2 - case s <= 8: - h ^= uint64(readUnaligned32(p)) - h ^= uint64(readUnaligned32(add(p, s-4))) << 32 - h = rotl_31(h*m1) * m2 + a = uintptr(*(*byte)(p)) + a |= uintptr(*(*byte)(add(p, s>>1))) << 8 + a |= uintptr(*(*byte)(add(p, s-1))) << 16 + case s == 4: + a = r4(p) + b = a + case s < 8: + a = r4(p) + b = r4(add(p, s-4)) + case s == 8: + a = r8(p) + b = a case s <= 16: - h ^= readUnaligned64(p) - h = rotl_31(h*m1) * m2 - h ^= readUnaligned64(add(p, s-8)) - h = rotl_31(h*m1) * m2 - case s <= 32: - h ^= readUnaligned64(p) - h = rotl_31(h*m1) * m2 - h ^= readUnaligned64(add(p, 8)) - h = rotl_31(h*m1) * m2 - h ^= readUnaligned64(add(p, s-16)) - h = rotl_31(h*m1) * m2 - h ^= readUnaligned64(add(p, s-8)) - h = rotl_31(h*m1) * m2 + a = r8(p) + b = r8(add(p, s-8)) default: - v1 := h - v2 := uint64(seed * hashkey[1]) - v3 := uint64(seed * hashkey[2]) - v4 := uint64(seed * hashkey[3]) - for s >= 32 { - v1 ^= readUnaligned64(p) - v1 = rotl_31(v1*m1) * m2 - p = add(p, 8) - v2 ^= readUnaligned64(p) - v2 = rotl_31(v2*m2) * m3 - p = add(p, 8) - v3 ^= readUnaligned64(p) - v3 = rotl_31(v3*m3) * m4 - p = add(p, 8) - v4 ^= readUnaligned64(p) - v4 = rotl_31(v4*m4) * m1 - p = add(p, 8) - s -= 32 + l := s + if l > 48 { + seed1 := seed + seed2 := seed + for ; l > 48; l -= 48 { + seed = mix(r8(p)^m2, r8(add(p, 8))^seed) + seed1 = mix(r8(add(p, 16))^m3, r8(add(p, 24))^seed1) + seed2 = mix(r8(add(p, 32))^m4, r8(add(p, 40))^seed2) + p = add(p, 48) + } + seed ^= seed1 ^ seed2 + } + for ; l > 16; l -= 16 { + seed = mix(r8(p)^m2, r8(add(p, 8))^seed) + p = add(p, 16) } - h = v1 ^ v2 ^ v3 ^ v4 - goto tail + a = r8(add(p, l-16)) + b = r8(add(p, l-8)) } - h ^= h >> 29 - h *= m3 - h ^= h >> 32 - return uintptr(h) + return mix(m5^s, mix(a^m2, b^seed)) } func memhash32(p unsafe.Pointer, seed uintptr) uintptr { - h := uint64(seed + 4*hashkey[0]) - v := uint64(readUnaligned32(p)) - h ^= v - h ^= v << 32 - h = rotl_31(h*m1) * m2 - h ^= h >> 29 - h *= m3 - h ^= h >> 32 - return uintptr(h) + a := r4(p) + return mix(m5^4, mix(a^m2, a^seed^hashkey[0]^m1)) } func memhash64(p unsafe.Pointer, seed uintptr) uintptr { - h := uint64(seed + 8*hashkey[0]) - h ^= uint64(readUnaligned32(p)) | uint64(readUnaligned32(add(p, 4)))<<32 - h = rotl_31(h*m1) * m2 - h ^= h >> 29 - h *= m3 - h ^= h >> 32 - return uintptr(h) + a := r8(p) + return mix(m5^8, mix(a^m2, a^seed^hashkey[0]^m1)) +} + +func mix(a, b uintptr) uintptr { + hi, lo := math.Mul64(uint64(a), uint64(b)) + return uintptr(hi ^ lo) +} + +func r4(p unsafe.Pointer) uintptr { + return uintptr(readUnaligned32(p)) } -// Note: in order to get the compiler to issue rotl instructions, we -// need to constant fold the shift amount by hand. -// TODO: convince the compiler to issue rotl instructions after inlining. -func rotl_31(x uint64) uint64 { - return (x << 31) | (x >> (64 - 31)) +func r8(p unsafe.Pointer) uintptr { + return uintptr(readUnaligned64(p)) } |