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Diffstat (limited to 'support/Random.h')
| -rw-r--r-- | support/Random.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/support/Random.h b/support/Random.h new file mode 100644 index 0000000000..1a804d3290 --- /dev/null +++ b/support/Random.h @@ -0,0 +1,103 @@ +/* + * Copyright (c) 2019-2021 Arm Limited. + * + * SPDX-License-Identifier: MIT + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#ifndef ARM_COMPUTE_MISC_RANDOM_H +#define ARM_COMPUTE_MISC_RANDOM_H + +#include "arm_compute/core/Error.h" + +#include "utils/Utils.h" + +#include <random> +#include <type_traits> + +namespace arm_compute +{ +namespace utils +{ +namespace random +{ +/** Uniform distribution within a given number of sub-ranges + * + * @tparam T Distribution primitive type + */ +template <typename T> +class RangedUniformDistribution +{ +public: + static constexpr bool is_fp_16bit = std::is_same<T, half>::value || std::is_same<T, bfloat16>::value; + static constexpr bool is_integral = std::is_integral<T>::value && !is_fp_16bit; + + using fp_dist = typename std::conditional<is_fp_16bit, + arm_compute::utils::uniform_real_distribution_16bit<T>, + std::uniform_real_distribution<T>>::type; + using DT = typename std::conditional<is_integral, std::uniform_int_distribution<T>, fp_dist>::type; + using result_type = T; + using range_pair = std::pair<result_type, result_type>; + + /** Constructor + * + * @param[in] low lowest value in the range (inclusive) + * @param[in] high highest value in the range (inclusive for uniform_int_distribution, exclusive for uniform_real_distribution) + * @param[in] exclude_ranges Ranges to exclude from the generator + */ + RangedUniformDistribution(result_type low, result_type high, const std::vector<range_pair> &exclude_ranges) + : _distributions(), _selector() + { + result_type clow = low; + for (const auto &erange : exclude_ranges) + { + result_type epsilon = is_integral ? result_type(1) : result_type(std::numeric_limits<T>::epsilon()); + + ARM_COMPUTE_ERROR_ON(clow > erange.first || clow >= erange.second); + + _distributions.emplace_back(DT(clow, erange.first - epsilon)); + clow = erange.second + epsilon; + } + ARM_COMPUTE_ERROR_ON(clow > high); + _distributions.emplace_back(DT(clow, high)); + _selector = std::uniform_int_distribution<uint32_t>(0, _distributions.size() - 1); + } + /** Generate random number + * + * @tparam URNG Random number generator object type + * + * @param[in] g A uniform random number generator object, used as the source of randomness. + * + * @return A new random number. + */ + template <class URNG> + result_type operator()(URNG &g) + { + unsigned int rand_select = _selector(g); + return _distributions[rand_select](g); + } + +private: + std::vector<DT> _distributions; + std::uniform_int_distribution<uint32_t> _selector; +}; +} // namespace random +} // namespace utils +} // namespace arm_compute +#endif /* ARM_COMPUTE_MISC_RANDOM_H */ |