mindspore2022/mindspore/ccsrc/utils/hashing.h

37 lines
1.3 KiB
C++

/**
* Copyright 2019 Huawei Technologies Co., Ltd
*
* 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 MINDSPORE_CCSRC_UTILS_HASHING_H_
#define MINDSPORE_CCSRC_UTILS_HASHING_H_
#include <initializer_list>
namespace mindspore {
inline std::size_t hash_combine(std::size_t hash_sum, std::size_t hash_val) {
// Reference from http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0814r0.pdf
return ((hash_sum << 6) + (hash_sum >> 2) + 0x9e3779b9 + hash_val) ^ hash_sum;
}
inline std::size_t hash_combine(const std::initializer_list<std::size_t>& hash_vals) {
std::size_t hash_sum = 0;
for (auto hash_val : hash_vals) {
hash_sum = hash_combine(hash_sum, hash_val);
}
return hash_sum;
}
} // namespace mindspore
#endif // MINDSPORE_CCSRC_UTILS_HASHING_H_