// Copyright 2014 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Hashing algorithm inspired by // wyhash: https://github.com/wangyi-fudan/wyhash //go:build amd64 || arm64 || loong64 || mips64 || mips64le || ppc64 || ppc64le || riscv64 || s390x || wasm package runtime import ( "runtime/internal/math" "unsafe" ) const ( m1 = 0xa0761d6478bd642f m2 = 0xe7037ed1a0b428db m3 = 0x8ebc6af09c88c6e3 m4 = 0x589965cc75374cc3 m5 = 0x1d8e4e27c47d124f ) func memhashFallback(p unsafe.Pointer, seed, s uintptr) uintptr { var a, b uintptr seed ^= hashkey[0] ^ m1 switch { case s == 0: return seed case s < 4: 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: a = r8(p) b = r8(add(p, s-8)) default: 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) } a = r8(add(p, l-16)) b = r8(add(p, l-8)) } return mix(m5^s, mix(a^m2, b^seed)) } func memhash32Fallback(p unsafe.Pointer, seed uintptr) uintptr { a := r4(p) return mix(m5^4, mix(a^m2, a^seed^hashkey[0]^m1)) } func memhash64Fallback(p unsafe.Pointer, seed uintptr) uintptr { 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)) } func r8(p unsafe.Pointer) uintptr { return uintptr(readUnaligned64(p)) }