10b57cec5SDimitry Andric //===-- sanitizer_common.h --------------------------------------*- C++ -*-===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric // 90b57cec5SDimitry Andric // This file implements a simple hash function. 100b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 110b57cec5SDimitry Andric 120b57cec5SDimitry Andric #ifndef SANITIZER_HASH_H 130b57cec5SDimitry Andric #define SANITIZER_HASH_H 140b57cec5SDimitry Andric 150b57cec5SDimitry Andric #include "sanitizer_internal_defs.h" 160b57cec5SDimitry Andric 170b57cec5SDimitry Andric namespace __sanitizer { 180b57cec5SDimitry Andric class MurMur2HashBuilder { 190b57cec5SDimitry Andric static const u32 m = 0x5bd1e995; 200b57cec5SDimitry Andric static const u32 seed = 0x9747b28c; 210b57cec5SDimitry Andric static const u32 r = 24; 220b57cec5SDimitry Andric u32 h; 230b57cec5SDimitry Andric 240b57cec5SDimitry Andric public: 250b57cec5SDimitry Andric explicit MurMur2HashBuilder(u32 init = 0) { h = seed ^ init; } add(u32 k)260b57cec5SDimitry Andric void add(u32 k) { 270b57cec5SDimitry Andric k *= m; 280b57cec5SDimitry Andric k ^= k >> r; 290b57cec5SDimitry Andric k *= m; 300b57cec5SDimitry Andric h *= m; 310b57cec5SDimitry Andric h ^= k; 320b57cec5SDimitry Andric } get()330b57cec5SDimitry Andric u32 get() { 340b57cec5SDimitry Andric u32 x = h; 350b57cec5SDimitry Andric x ^= x >> 13; 360b57cec5SDimitry Andric x *= m; 370b57cec5SDimitry Andric x ^= x >> 15; 380b57cec5SDimitry Andric return x; 390b57cec5SDimitry Andric } 400b57cec5SDimitry Andric }; 41*349cc55cSDimitry Andric 42*349cc55cSDimitry Andric class MurMur2Hash64Builder { 43*349cc55cSDimitry Andric static const u64 m = 0xc6a4a7935bd1e995ull; 44*349cc55cSDimitry Andric static const u64 seed = 0x9747b28c9747b28cull; 45*349cc55cSDimitry Andric static const u64 r = 47; 46*349cc55cSDimitry Andric u64 h; 47*349cc55cSDimitry Andric 48*349cc55cSDimitry Andric public: 49*349cc55cSDimitry Andric explicit MurMur2Hash64Builder(u64 init = 0) { h = seed ^ (init * m); } add(u64 k)50*349cc55cSDimitry Andric void add(u64 k) { 51*349cc55cSDimitry Andric k *= m; 52*349cc55cSDimitry Andric k ^= k >> r; 53*349cc55cSDimitry Andric k *= m; 54*349cc55cSDimitry Andric h ^= k; 55*349cc55cSDimitry Andric h *= m; 56*349cc55cSDimitry Andric } get()57*349cc55cSDimitry Andric u64 get() { 58*349cc55cSDimitry Andric u64 x = h; 59*349cc55cSDimitry Andric x ^= x >> r; 60*349cc55cSDimitry Andric x *= m; 61*349cc55cSDimitry Andric x ^= x >> r; 62*349cc55cSDimitry Andric return x; 63*349cc55cSDimitry Andric } 64*349cc55cSDimitry Andric }; 650b57cec5SDimitry Andric } // namespace __sanitizer 660b57cec5SDimitry Andric 670b57cec5SDimitry Andric #endif // SANITIZER_HASH_H 68