1 /*
2 * Copyright (c) 2018-2021 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
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_WINDOW_ITERATOR_H
25 #define ARM_COMPUTE_WINDOW_ITERATOR_H
26 #include "arm_compute/core/Coordinates.h"
27 #include "arm_compute/core/Error.h"
28 #include "arm_compute/core/ITensor.h"
29 #include "arm_compute/core/Window.h"
30
31
32 namespace arm_compute
33 {
34 /** Convert an offset in window steps into absolute coordinates.
35 *
36 * @param[in] w Window @p offset is related to.
37 * @param[in] offset Offset inside the window expressed in number of window steps.
38 *
39 * @return Absolute coordinates.
40 */
convert_window_coord_to_position(const Window & w,const Coordinates & offset)41 inline Coordinates convert_window_coord_to_position(const Window &w, const Coordinates &offset)
42 {
43 Coordinates position;
44 for(unsigned int i = 0; i < Coordinates::num_max_dimensions; ++i)
45 {
46 position.set(i, w[i].start() + offset[i] * w[i].step());
47 }
48 return position;
49 }
50
51 /** Tensor accessors to make it easier to interface with arm_gemm */
52 template <typename T>
53 class TensorAccessor
54 {
55 public:
56 /** Constructor:
57 *
58 * @param[in] tensor Source tensor, must be allocated.
59 */
TensorAccessor(const ITensor & tensor)60 TensorAccessor(const ITensor &tensor)
61 : _first(tensor.ptr_to_element(Coordinates())), _strides(tensor.info()->strides_in_bytes())
62 {
63 }
64 /** Get the stride of the dimension dim expressed in number of Ts.
65 *
66 * @param[in] dim Dimension of the wanted stride.
67 *
68 * @return Stride in number of Ts.
69 */
stride(size_t dim)70 inline size_t stride(size_t dim) const
71 {
72 ARM_COMPUTE_ERROR_ON(_strides[dim] % sizeof(T) != 0);
73 return _strides[dim] / sizeof(T);
74 }
75
76 /** Manually set the stride of a dimension
77 *
78 * @param[in] dim Dimension of the stride to set.
79 * @param[in] size Value to set the stride to (in bytes).
80 */
set_stride(size_t dim,size_t size)81 void set_stride(size_t dim, size_t size)
82 {
83 _strides[dim] = size;
84 }
85
86 /** Manually set the strides
87 *
88 * @param[in] strides Strides to set
89 */
set_strides(const Strides & strides)90 void set_strides(const Strides &strides)
91 {
92 _strides = strides;
93 }
94
95 /** Returns a pointer to the element at coordinates (x,y,z,w)
96 *
97 * @param[in] x X coordinates
98 * @param[in] y (optional) Y coordinates
99 * @param[in] z (optional) Z coordinates
100 * @param[in] w (optional) W coordinates
101 */
102 inline T *get_ptr(unsigned int x, unsigned int y = 0, unsigned int z = 0, unsigned int w = 0)
103 {
104 return reinterpret_cast<T *>(_first + x * _strides[0] + y * _strides[1] + z * _strides[2] + w * _strides[3]);
105 }
106
107 /** Returns a pointer to the element at coordinates (x,y,z,w)
108 *
109 * @param[in] x X coordinates
110 * @param[in] y (optional) Y coordinates
111 * @param[in] z (optional) Z coordinates
112 * @param[in] w (optional) W coordinates
113 */
operator()114 inline T *operator()(unsigned int x, unsigned int y = 0, unsigned int z = 0, unsigned int w = 0)
115 {
116 return get_ptr(x, y, z, w);
117 }
118
119 /** Returns a pointer to the first element of the tensor
120 *
121 * @return Pointer to the first element.
122 */
first_element()123 inline T *first_element()
124 {
125 return reinterpret_cast<T *>(_first);
126 }
127
128 /** Returns a pointer to the first element of the tensor
129 *
130 * @return Pointer to the first element.
131 */
operator()132 inline T *operator()()
133 {
134 return first_element();
135 }
136
137 private:
138 uint8_t *_first; /**< Pointer to the first element of the tensor.*/
139 Strides _strides; /**< Strides in bytes of the tensor */
140 };
141
142 /** Iterate over a portion of a Window */
143 template <typename L>
144 class WindowIterator
145 {
146 public:
147 /** Construct a WindowIterator object
148 *
149 * @param[in] w Window to use for the iteration
150 * @param[in] start Where to start iterating from (In Window coordinates)
151 * @param[in] end Where to stop iterating (In Window coordinates).
152 * @param[in] lambda_function Lambda function to call for every iteration between start and end. (It will be called last for end - 1)
153 */
WindowIterator(const Window & w,const Coordinates & start,const Coordinates & end,L && lambda_function)154 WindowIterator(const Window &w, const Coordinates &start, const Coordinates &end, L &&lambda_function)
155 : _lambda_function(std::move(lambda_function)),
156 _position(convert_window_coord_to_position(w, start)),
157 _end(convert_window_coord_to_position(w, end)),
158 _w(w)
159 {
160 }
161 /** Iterate over the lowest 3 dimensions of the window.
162 *
163 * @param[in] on_new_row_size Callback to be called before lambda_function every time the width of the row processed changes.
164 */
165 template <typename M>
iterate_3D(M && on_new_row_size)166 void iterate_3D(M &&on_new_row_size)
167 {
168 while(_end.z() != _position.z())
169 {
170 iterate_2D_internal(on_new_row_size, _w.x().end() - _w.x().step(), _w.y().end() - _w.y().step());
171 _position[2] += _w.z().step();
172 _position[1] = _w.y().start();
173 _position[0] = _w.x().start();
174 }
175 // Left over:
176 iterate_2D(on_new_row_size);
177 }
178
179 /** Iterate over the lowest 2 dimensions of the window.
180 *
181 * @param[in] on_new_row_size Callback to be called before lambda_function every time the width of the row processed changes.
182 */
183 template <typename M>
iterate_2D(M && on_new_row_size)184 void iterate_2D(M &&on_new_row_size)
185 {
186 iterate_2D_internal(on_new_row_size, _end.x(), _end.y());
187 }
188
189 /** Change the step used for the iteration.
190 *
191 * @note Does not affect the start and end points.
192 *
193 * @param[in] dim Dimension to change
194 * @param[in] step New step to use for the given dimension.
195 */
set_step(size_t dim,int step)196 inline void set_step(size_t dim, int step)
197 {
198 _w.set_dimension_step(dim, step);
199 }
200
201 /** Returns the coordinates in absolute coordinates of the end position
202 *
203 * @return End position coordinates.
204 */
end_position()205 const Coordinates &end_position() const
206 {
207 return _end;
208 }
209
210 private:
211 template <typename M>
iterate_2D_internal(M && on_new_row_size,int end_x,int end_y)212 void iterate_2D_internal(M &&on_new_row_size, int end_x, int end_y)
213 {
214 //Is there more than one row to process ?
215 if(end_y == _position.y())
216 {
217 // Both start and end belong to the same row:
218 iterate_over_dim0(end_x + _w.x().step(), on_new_row_size);
219 }
220 else
221 {
222 // Do we start from the beginning of the row ?
223 if(_w.x().start() != _position.x())
224 {
225 //Start in the middle of a row: process left-over X
226 iterate_over_dim0(_w.x().end(), on_new_row_size);
227 _position[1] += _w.y().step();
228 }
229
230 //Middle rows
231 bool no_leftover = end_x + _w.x().step() == _w.x().end();
232 if(no_leftover)
233 {
234 //Switch to full row size:
235 on_new_row_size(_w[0].start(), _w.x().end());
236 // Shouldn't be possible to reach that point and not have at least one entire row to process
237 ARM_COMPUTE_ERROR_ON(_w.y().end() == _position.y());
238 // No leftover: all the rows lefts to process are full width:
239 iterate_over_dim1(end_y + _w.y().step());
240 }
241 else
242 {
243 // Are there full rows to process ?
244 if(_position[1] != end_y)
245 {
246 //Switch to full row size:
247 on_new_row_size(_w[0].start(), _w.x().end());
248 iterate_over_dim1(end_y);
249 }
250
251 //Leftover end x
252 _position[0] = _w.x().start();
253 iterate_over_dim0(end_x + _w.x().step(), on_new_row_size);
254 }
255 }
256 }
257
258 /** Process full rows below 'end'
259 *
260 * @param[in] end Y position to stop at.
261 */
iterate_over_dim1(int end)262 void iterate_over_dim1(int end)
263 {
264 for(; _position[1] != end; _position[1] += _w[1].step())
265 {
266 _position[0] = _w[0].start();
267 iterate_over_dim0(_w[0].end());
268 }
269 }
270
271 /** Process elements of a given row up to 'end'
272 *
273 * @param[in] end X position to stop at.
274 * @param[in] on_new_row_size Callback to call before starting iterating
275 */
276 template <typename M>
iterate_over_dim0(int end,M && on_new_row_size)277 void iterate_over_dim0(int end, M &&on_new_row_size)
278 {
279 on_new_row_size(_position.x(), end);
280 iterate_over_dim0(end);
281 }
282
283 /** Process elements of a given row up to 'end'
284 *
285 * @param[in] end X position to stop at.
286 */
iterate_over_dim0(int end)287 void iterate_over_dim0(int end)
288 {
289 // Both start and end belong to the same row:
290 ARM_COMPUTE_ERROR_ON(_position[0] > end);
291 for(; _position.x() < end; _position[0] += _w[0].step())
292 {
293 _lambda_function(_position);
294 }
295 }
296
297 L _lambda_function; /**< Function to call for each iteration */
298 Coordinates _position; /**< Absolute coordinates of the current position */
299 Coordinates _end; /**< Absolute coordinates of the point after the last iteration */
300 Window _w; /**< Window to iterate over */
301 };
302
303 /** Create a WindowIterator object
304 *
305 * @param[in] w Window to use for the iteration
306 * @param[in] start Where to start iterating from (In Window coordinates)
307 * @param[in] end Where to stop iterating (In Window coordinates).
308 * @param[in] lambda_function Lambda function to call for every iteration between start and end. (It will be called last for end - 1)
309 *
310 * @return A WindowIterator object.
311 */
312 template <typename L>
create_window_iterator(const Window & w,const Coordinates & start,const Coordinates & end,L && lambda_function)313 WindowIterator<L> create_window_iterator(const Window &w, const Coordinates &start, const Coordinates &end, L &&lambda_function)
314 {
315 return WindowIterator<L>(w, start, end, std::move(lambda_function));
316 }
317 }
318 #endif /*ARM_COMPUTE_WINDOW_ITERATOR_H*/
319