| // 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/blob/ceb019b530e2c1c14d70b79bfa2bc49de7d95bc1/Modern%20Non-Cryptographic%20Hash%20Function%20and%20Pseudorandom%20Number%20Generator.pdf | |
| //go:build 386 || arm || mips || mipsle || wasm || (gccgo && (ppc || s390)) | |
| package maps | |
| import "unsafe" | |
| func memHash32Fallback(k uint32, seed uintptr) uintptr { | |
| a, b := mix32(uint32(seed), uint32(4^hashkey[0])) | |
| a ^= k | |
| b ^= k | |
| a, b = mix32(a, b) | |
| a, b = mix32(a, b) | |
| return uintptr(a ^ b) | |
| } | |
| func memHash64Fallback(k uint64, seed uintptr) uintptr { | |
| a, b := mix32(uint32(seed), uint32(8^hashkey[0])) | |
| a ^= uint32(k) | |
| b ^= uint32(k >> 32) | |
| a, b = mix32(a, b) | |
| a, b = mix32(a, b) | |
| return uintptr(a ^ b) | |
| } | |
| func memHashFallback(p unsafe.Pointer, seed, s uintptr) uintptr { | |
| a, b := mix32(uint32(seed), uint32(s^hashkey[0])) | |
| if s == 0 { | |
| return uintptr(a ^ b) | |
| } | |
| for ; s > 8; s -= 8 { | |
| a ^= readUnaligned32(p) | |
| b ^= readUnaligned32(add(p, 4)) | |
| a, b = mix32(a, b) | |
| p = add(p, 8) | |
| } | |
| if s >= 4 { | |
| a ^= readUnaligned32(p) | |
| b ^= readUnaligned32(add(p, s-4)) | |
| } else { | |
| t := uint32(*(*byte)(p)) | |
| t |= uint32(*(*byte)(add(p, s>>1))) << 8 | |
| t |= uint32(*(*byte)(add(p, s-1))) << 16 | |
| b ^= t | |
| } | |
| a, b = mix32(a, b) | |
| a, b = mix32(a, b) | |
| return uintptr(a ^ b) | |
| } | |
| func mix32(a, b uint32) (uint32, uint32) { | |
| c := uint64(a^uint32(hashkey[1])) * uint64(b^uint32(hashkey[2])) | |
| return uint32(c), uint32(c >> 32) | |
| } |