Compute Library
 21.02
Random.h
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1 /*
2  * Copyright (c) 2019-2021 Arm Limited.
3  *
4  * SPDX-License-Identifier: MIT
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
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10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
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13  * The above copyright notice and this permission notice shall be included in all
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16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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24 #ifndef ARM_COMPUTE_MISC_RANDOM_H
25 #define ARM_COMPUTE_MISC_RANDOM_H
26 
27 #include "arm_compute/core/Error.h"
28 #include "utils/Utils.h"
29 
30 #include <random>
31 #include <type_traits>
32 
33 namespace arm_compute
34 {
35 namespace utils
36 {
37 namespace random
38 {
39 /** Uniform distribution within a given number of sub-ranges
40  *
41  * @tparam T Distribution primitive type
42  */
43 template <typename T>
45 {
46 public:
47  static constexpr bool is_fp_16bit = std::is_same<T, half>::value || std::is_same<T, bfloat16>::value;
48  static constexpr bool is_integral = std::is_integral<T>::value && !is_fp_16bit;
49 
50  using fp_dist = typename std::conditional<is_fp_16bit, arm_compute::utils::uniform_real_distribution_16bit<T>, std::uniform_real_distribution<T>>::type;
51  using DT = typename std::conditional<is_integral, std::uniform_int_distribution<T>, fp_dist>::type;
52  using result_type = T;
53  using range_pair = std::pair<result_type, result_type>;
54 
55  /** Constructor
56  *
57  * @param[in] low lowest value in the range (inclusive)
58  * @param[in] high highest value in the range (inclusive for uniform_int_distribution, exclusive for uniform_real_distribution)
59  * @param[in] exclude_ranges Ranges to exclude from the generator
60  */
61  RangedUniformDistribution(result_type low, result_type high, const std::vector<range_pair> &exclude_ranges)
62  : _distributions(), _selector()
63  {
64  result_type clow = low;
65  for(const auto &erange : exclude_ranges)
66  {
68 
69  ARM_COMPUTE_ERROR_ON(clow > erange.first || clow >= erange.second);
70 
71  _distributions.emplace_back(DT(clow, erange.first - epsilon));
72  clow = erange.second + epsilon;
73  }
74  ARM_COMPUTE_ERROR_ON(clow > high);
75  _distributions.emplace_back(DT(clow, high));
76  _selector = std::uniform_int_distribution<uint32_t>(0, _distributions.size() - 1);
77  }
78  /** Generate random number
79  *
80  * @tparam URNG Random number generator object type
81  *
82  * @param[in] g A uniform random number generator object, used as the source of randomness.
83  *
84  * @return A new random number.
85  */
86  template <class URNG>
88  {
89  unsigned int rand_select = _selector(g);
90  return _distributions[rand_select](g);
91  }
92 
93 private:
94  std::vector<DT> _distributions;
95  std::uniform_int_distribution<uint32_t> _selector;
96 };
97 } // namespace random
98 } // namespace utils
99 } // namespace arm_compute
100 #endif /* ARM_COMPUTE_MISC_RANDOM_H */
Uniform distribution within a given number of sub-ranges.
Definition: Random.h:44
#define ARM_COMPUTE_ERROR_ON(cond)
If the condition is true then an error message is printed and an exception thrown.
Definition: Error.h:466
decltype(strategy::transforms) typedef type
Copyright (c) 2017-2021 Arm Limited.
typename std::conditional< is_fp_16bit, arm_compute::utils::uniform_real_distribution_16bit< T >, std::uniform_real_distribution< T > >::type fp_dist
Definition: Random.h:50
RangedUniformDistribution(result_type low, result_type high, const std::vector< range_pair > &exclude_ranges)
Constructor.
Definition: Random.h:61
std::pair< result_type, result_type > range_pair
Definition: Random.h:53
result_type operator()(URNG &g)
Generate random number.
Definition: Random.h:87
typename std::conditional< is_integral, std::uniform_int_distribution< T >, fp_dist >::type DT
Definition: Random.h:51