• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (c) 2016-2020 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
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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:
12  *
13  * The above copyright notice and this permission notice shall be included in all
14  * copies or substantial portions of the Software.
15  *
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,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 #ifndef ARM_COMPUTE_TENSORSHAPE_H
25 #define ARM_COMPUTE_TENSORSHAPE_H
26 
27 #include "arm_compute/core/Dimensions.h"
28 #include "arm_compute/core/Error.h"
29 #include "arm_compute/core/utils/misc/Utility.h"
30 
31 #include <algorithm>
32 #include <array>
33 #include <functional>
34 #include <numeric>
35 
36 namespace arm_compute
37 {
38 /** Shape of a tensor */
39 class TensorShape : public Dimensions<size_t>
40 {
41 public:
42     /** Constructor to initialize the tensor shape.
43      *
44      * @param[in] dims Values to initialize the dimensions.
45      */
46     template <typename... Ts>
TensorShape(Ts...dims)47     TensorShape(Ts... dims)
48         : Dimensions{ dims... }
49     {
50         // Initialize unspecified dimensions to 1
51         if(_num_dimensions > 0)
52         {
53             std::fill(_id.begin() + _num_dimensions, _id.end(), 1);
54         }
55 
56         // Correct number dimensions to ignore trailing dimensions of size 1
57         apply_dimension_correction();
58     }
59     /** Allow instances of this class to be copy constructed */
60     TensorShape(const TensorShape &) = default;
61     /** Allow instances of this class to be copied */
62     TensorShape &operator=(const TensorShape &) = default;
63     /** Allow instances of this class to be move constructed */
64     TensorShape(TensorShape &&) = default;
65     /** Allow instances of this class to be moved */
66     TensorShape &operator=(TensorShape &&) = default;
67     /** Default destructor */
68     ~TensorShape() = default;
69 
70     /** Accessor to set the value of one of the dimensions.
71      *
72      * @param[in] dimension            Dimension for which the value is set.
73      * @param[in] value                Value to be set for the dimension.
74      * @param[in] apply_dim_correction Flag to state whether apply dimension correction after setting one dimension. E.g. when permuting NCHW -> NHWC, 1x1x2 would become 2x1x1, but _num_dimensions should be 3 rather than 1.
75      *
76      * @return *this.
77      */
78     TensorShape &set(size_t dimension, size_t value, bool apply_dim_correction = true)
79     {
80         // Clear entire shape if one dimension is zero
81         if(value == 0)
82         {
83             _num_dimensions = 0;
84             std::fill(_id.begin(), _id.end(), 0);
85         }
86         else
87         {
88             // Make sure all empty dimensions are filled with 1
89             std::fill(_id.begin() + _num_dimensions, _id.end(), 1);
90 
91             // Set the specified dimension and increase the number of dimensions if
92             // necessary
93             Dimensions::set(dimension, value);
94 
95             // Correct number dimensions to ignore trailing dimensions of size 1
96             if(apply_dim_correction)
97             {
98                 apply_dimension_correction();
99             }
100         }
101         return *this;
102     }
103 
104     /** Accessor to remove the dimension n from the tensor shape.
105      *
106      * @note The upper dimensions of the tensor shape will be shifted down by 1
107      *
108      * @param[in] n Dimension to remove
109      */
remove_dimension(size_t n)110     void remove_dimension(size_t n)
111     {
112         ARM_COMPUTE_ERROR_ON(_num_dimensions < 1);
113         ARM_COMPUTE_ERROR_ON(n >= _num_dimensions);
114 
115         std::copy(_id.begin() + n + 1, _id.end(), _id.begin() + n);
116 
117         // Reduce number of dimensions
118         _num_dimensions--;
119 
120         // Make sure all empty dimensions are filled with 1
121         std::fill(_id.begin() + _num_dimensions, _id.end(), 1);
122 
123         // Correct number dimensions to ignore trailing dimensions of size 1
124         apply_dimension_correction();
125     }
126 
127     /** Collapse the first n dimensions.
128      *
129      * @param[in] n     Number of dimensions to collapse into @p first
130      * @param[in] first Dimensions into which the following @p n are collapsed.
131      */
132     void collapse(size_t n, size_t first = 0)
133     {
134         Dimensions::collapse(n, first);
135 
136         // Make sure all empty dimensions are filled with 1
137         std::fill(_id.begin() + _num_dimensions, _id.end(), 1);
138     }
139     /** Shifts right the tensor shape increasing its dimensions
140      *
141      * @param[in] step Rotation step
142      */
shift_right(size_t step)143     void shift_right(size_t step)
144     {
145         ARM_COMPUTE_ERROR_ON(step > TensorShape::num_max_dimensions - num_dimensions());
146 
147         std::rotate(begin(), begin() + TensorShape::num_max_dimensions - step, end());
148         _num_dimensions += step;
149 
150         // Correct number dimensions to ignore trailing dimensions of size 1
151         apply_dimension_correction();
152     }
153 
154     /** Return a copy with collapsed dimensions starting from a given point.
155      *
156      * @param[in] start Starting point of collapsing dimensions.
157      *
158      * @return A copy with collapse dimensions starting from start.
159      */
collapsed_from(size_t start)160     TensorShape collapsed_from(size_t start) const
161     {
162         TensorShape copy(*this);
163         copy.collapse(num_dimensions() - start, start);
164         return copy;
165     }
166 
167     /** Collapses all dimensions to a single linear total size.
168      *
169      * @return The total tensor size in terms of elements.
170      */
total_size()171     size_t total_size() const
172     {
173         return std::accumulate(_id.begin(), _id.end(), 1, std::multiplies<size_t>());
174     }
175     /** Collapses given dimension and above.
176      *
177      * @param[in] dimension Size of the wanted dimension
178      *
179      * @return The linear size of the collapsed dimensions
180      */
total_size_upper(size_t dimension)181     size_t total_size_upper(size_t dimension) const
182     {
183         ARM_COMPUTE_ERROR_ON(dimension >= TensorShape::num_max_dimensions);
184         return std::accumulate(_id.begin() + dimension, _id.end(), 1, std::multiplies<size_t>());
185     }
186 
187     /** Compute size of dimensions lower than the given one.
188      *
189      * @param[in] dimension Upper boundary.
190      *
191      * @return The linear size of the collapsed dimensions.
192      */
total_size_lower(size_t dimension)193     size_t total_size_lower(size_t dimension) const
194     {
195         ARM_COMPUTE_ERROR_ON(dimension > TensorShape::num_max_dimensions);
196         return std::accumulate(_id.begin(), _id.begin() + dimension, 1, std::multiplies<size_t>());
197     }
198 
199     /** If shapes are broadcast compatible, return the broadcasted shape.
200      *
201      * Two tensor shapes are broadcast compatible if for each dimension, they're equal or one of them is 1.
202      *
203      * If two shapes are compatible, each dimension in the broadcasted shape is the max of the original dimensions.
204      *
205      * @param[in] shapes Tensor shapes.
206      *
207      * @return The broadcasted shape or an empty shape if the shapes are not broadcast compatible.
208      */
209     template <typename... Shapes>
broadcast_shape(const Shapes &...shapes)210     static TensorShape broadcast_shape(const Shapes &... shapes)
211     {
212         TensorShape bc_shape;
213 
214         auto broadcast = [&bc_shape](const TensorShape & other)
215         {
216             if(bc_shape.num_dimensions() == 0)
217             {
218                 bc_shape = other;
219             }
220             else if(other.num_dimensions() != 0)
221             {
222                 for(size_t d = 0; d < TensorShape::num_max_dimensions; ++d)
223                 {
224                     const size_t dim_min = std::min(bc_shape[d], other[d]);
225                     const size_t dim_max = std::max(bc_shape[d], other[d]);
226 
227                     if((dim_min != 1) && (dim_min != dim_max))
228                     {
229                         bc_shape = TensorShape{ 0U };
230                         break;
231                     }
232 
233                     bc_shape.set(d, dim_max);
234                 }
235             }
236         };
237 
238         utility::for_each(broadcast, shapes...);
239 
240         return bc_shape;
241     }
242 
243 private:
244     /** Remove trailing dimensions of size 1 from the reported number of dimensions. */
apply_dimension_correction()245     void apply_dimension_correction()
246     {
247         for(int i = static_cast<int>(_num_dimensions) - 1; i > 0; --i)
248         {
249             if(_id[i] == 1)
250             {
251                 --_num_dimensions;
252             }
253             else
254             {
255                 break;
256             }
257         }
258     }
259 };
260 }
261 #endif /*ARM_COMPUTE_TENSORSHAPE_H*/
262