1 /* 2 * Copyright 2017 WebAssembly Community Group participants 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "src/hash-util.h" 18 19 #include "config.h" 20 21 namespace wabt { 22 23 // Hash combiner from: 24 // http://stackoverflow.com/questions/4948780/magic-number-in-boosthash-combine 25 HashCombine(hash_code seed,hash_code y)26hash_code HashCombine(hash_code seed, hash_code y) { 27 #if SIZEOF_SIZE_T == 4 28 constexpr hash_code magic = 0x9e3779b9; 29 #elif SIZEOF_SIZE_T == 8 30 constexpr hash_code magic = 0x9e3779b97f4a7c16; 31 #else 32 #error "weird sizeof size_t" 33 #endif 34 seed ^= y + magic + (seed << 6) + (seed >> 2); 35 return seed; 36 } 37 38 } // namespace wabt 39