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/*
* Copyright 2015 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef wasm_support_hash_h
#define wasm_support_hash_h
#include <functional>
#include <stdint.h>
namespace wasm {
inline uint32_t rehash(uint32_t x, uint32_t y) { // see http://www.cse.yorku.ca/~oz/hash.html
uint32_t hash = 5381;
while (x) {
hash = ((hash << 5) + hash) ^ (x & 0xff);
x >>= 8;
}
while (y) {
hash = ((hash << 5) + hash) ^ (y & 0xff);
y >>= 8;
}
return hash;
}
inline uint64_t rehash(uint64_t x, uint64_t y) { // see boost and https://stackoverflow.com/a/2595226/1176841
return x ^ (y + 0x9e3779b9 + (x << 6) + (x >> 2));
}
} // namespace wasm
#endif // wasm_support_hash_h
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