1 /* 2 Copyright (c) 2017-2020 Intel Corporation 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 #ifndef __TBB_blocked_rangeNd_H 18 #define __TBB_blocked_rangeNd_H 19 20 #if ! TBB_PREVIEW_BLOCKED_RANGE_ND 21 #error Set TBB_PREVIEW_BLOCKED_RANGE_ND to include blocked_rangeNd.h 22 #endif 23 24 #include "tbb_config.h" 25 26 // tbb::blocked_rangeNd requires C++11 support 27 #if __TBB_CPP11_PRESENT && __TBB_CPP11_ARRAY_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT 28 29 #include "internal/_template_helpers.h" // index_sequence, make_index_sequence 30 31 #include <array> 32 #include <algorithm> // std::any_of 33 #include <type_traits> // std::is_same, std::enable_if 34 35 #include "tbb/blocked_range.h" 36 37 namespace tbb { 38 namespace internal { 39 40 /* 41 The blocked_rangeNd_impl uses make_index_sequence<N> to automatically generate a ctor with 42 exactly N arguments of the type tbb::blocked_range<Value>. Such ctor provides an opportunity 43 to use braced-init-list parameters to initialize each dimension. 44 Use of parameters, whose representation is a braced-init-list, but they're not 45 std::initializer_list or a reference to one, produces a non-deduced context 46 within template argument deduction. 47 48 NOTE: blocked_rangeNd must be exactly a templated alias to the blocked_rangeNd_impl 49 (and not e.g. a derived class), otherwise it would need to declare its own ctor 50 facing the same problem that the impl class solves. 51 */ 52 53 template<typename Value, unsigned int N, typename = make_index_sequence<N>> 54 class blocked_rangeNd_impl; 55 56 template<typename Value, unsigned int N, std::size_t... Is> 57 class blocked_rangeNd_impl<Value, N, index_sequence<Is...>> { 58 public: 59 //! Type of a value. 60 using value_type = Value; 61 62 private: 63 64 //! Helper type to construct range with N tbb::blocked_range<value_type> objects. 65 template<std::size_t> 66 using dim_type_helper = tbb::blocked_range<value_type>; 67 68 public: 69 blocked_rangeNd_impl() = delete; 70 71 //! Constructs N-dimensional range over N half-open intervals each represented as tbb::blocked_range<Value>. blocked_rangeNd_impl(const dim_type_helper<Is> &...args)72 blocked_rangeNd_impl(const dim_type_helper<Is>&... args) : my_dims{ {args...} } {} 73 74 //! Dimensionality of a range. ndims()75 static constexpr unsigned int ndims() { return N; } 76 77 //! Range in certain dimension. dim(unsigned int dimension)78 const tbb::blocked_range<value_type>& dim(unsigned int dimension) const { 79 __TBB_ASSERT(dimension < N, "out of bound"); 80 return my_dims[dimension]; 81 } 82 83 //------------------------------------------------------------------------ 84 // Methods that implement Range concept 85 //------------------------------------------------------------------------ 86 87 //! True if at least one dimension is empty. empty()88 bool empty() const { 89 return std::any_of(my_dims.begin(), my_dims.end(), [](const tbb::blocked_range<value_type>& d) { 90 return d.empty(); 91 }); 92 } 93 94 //! True if at least one dimension is divisible. is_divisible()95 bool is_divisible() const { 96 return std::any_of(my_dims.begin(), my_dims.end(), [](const tbb::blocked_range<value_type>& d) { 97 return d.is_divisible(); 98 }); 99 } 100 101 #if __TBB_USE_PROPORTIONAL_SPLIT_IN_BLOCKED_RANGES 102 //! Static field to support proportional split. 103 static const bool is_splittable_in_proportion = true; 104 blocked_rangeNd_impl(blocked_rangeNd_impl & r,proportional_split proportion)105 blocked_rangeNd_impl(blocked_rangeNd_impl& r, proportional_split proportion) : my_dims(r.my_dims) { 106 do_split(r, proportion); 107 } 108 #endif 109 blocked_rangeNd_impl(blocked_rangeNd_impl & r,split proportion)110 blocked_rangeNd_impl(blocked_rangeNd_impl& r, split proportion) : my_dims(r.my_dims) { 111 do_split(r, proportion); 112 } 113 114 private: 115 __TBB_STATIC_ASSERT(N != 0, "zero dimensional blocked_rangeNd can't be constructed"); 116 117 //! Ranges in each dimension. 118 std::array<tbb::blocked_range<value_type>, N> my_dims; 119 120 template<typename split_type> do_split(blocked_rangeNd_impl & r,split_type proportion)121 void do_split(blocked_rangeNd_impl& r, split_type proportion) { 122 __TBB_STATIC_ASSERT((is_same_type<split_type, split>::value 123 || is_same_type<split_type, proportional_split>::value), 124 "type of split object is incorrect"); 125 __TBB_ASSERT(r.is_divisible(), "can't split not divisible range"); 126 127 auto my_it = std::max_element(my_dims.begin(), my_dims.end(), [](const tbb::blocked_range<value_type>& first, const tbb::blocked_range<value_type>& second) { 128 return (first.size() * second.grainsize() < second.size() * first.grainsize()); 129 }); 130 131 auto r_it = r.my_dims.begin() + (my_it - my_dims.begin()); 132 133 my_it->my_begin = tbb::blocked_range<value_type>::do_split(*r_it, proportion); 134 135 // (!(my_it->my_begin < r_it->my_end) && !(r_it->my_end < my_it->my_begin)) equals to 136 // (my_it->my_begin == r_it->my_end), but we can't use operator== due to Value concept 137 __TBB_ASSERT(!(my_it->my_begin < r_it->my_end) && !(r_it->my_end < my_it->my_begin), 138 "blocked_range has been split incorrectly"); 139 } 140 }; 141 142 } // namespace internal 143 144 template<typename Value, unsigned int N> 145 using blocked_rangeNd = internal::blocked_rangeNd_impl<Value, N>; 146 147 } // namespace tbb 148 149 #endif /* __TBB_CPP11_PRESENT && __TBB_CPP11_ARRAY_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT */ 150 #endif /* __TBB_blocked_rangeNd_H */ 151