From ccd992355df7192993c666236047820244914598 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:19:13 +0200 Subject: Adding upstream version 1.21.8. Signed-off-by: Daniel Baumann --- src/runtime/hash32.go | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 src/runtime/hash32.go (limited to 'src/runtime/hash32.go') diff --git a/src/runtime/hash32.go b/src/runtime/hash32.go new file mode 100644 index 0000000..0616c7d --- /dev/null +++ b/src/runtime/hash32.go @@ -0,0 +1,62 @@ +// 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 + +package runtime + +import "unsafe" + +func memhash32Fallback(p unsafe.Pointer, seed uintptr) uintptr { + a, b := mix32(uint32(seed), uint32(4^hashkey[0])) + t := readUnaligned32(p) + a ^= t + b ^= t + a, b = mix32(a, b) + a, b = mix32(a, b) + return uintptr(a ^ b) +} + +func memhash64Fallback(p unsafe.Pointer, seed uintptr) uintptr { + a, b := mix32(uint32(seed), uint32(8^hashkey[0])) + a ^= readUnaligned32(p) + b ^= readUnaligned32(add(p, 4)) + 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) +} -- cgit v1.2.3