1 /* 2 * Copyright (c) 2025 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef ECMASCRIPT_BASE_HASH_COMBINE_H 17 #define ECMASCRIPT_BASE_HASH_COMBINE_H 18 19 #include <cstddef> 20 #include <cstdint> 21 #include "libpandabase/macros.h" 22 23 namespace panda::ecmascript::base { 24 class HashCombiner { 25 public: HashCombine(uint64_t seed,uint64_t value)26 static uint64_t HashCombine(uint64_t seed, uint64_t value) 27 { 28 // In the meantime, we're not considering 32-bit systems 29 ASSERT(sizeof(void *) == 8); // 8 : make sure the void* pointer is 8 bytes in size 30 const uint64_t m = uint64_t{0xC6A4A7935BD1E995}; 31 const uint32_t r = 47; 32 33 value *= m; 34 value ^= value >> r; 35 value *= m; 36 37 seed ^= value; 38 seed *= m; 39 return seed; 40 } 41 }; 42 } 43 #endif //HASH_COMBINE_H 44