COMPMID-344 Updated doxygen

Change-Id: I32f7b84daa560e460b77216add529c8fa8b327ae
diff --git a/src/core/CL/cl_kernels/pooling_layer.cl b/src/core/CL/cl_kernels/pooling_layer.cl
new file mode 100644
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+/*
+ * Copyright (c) 2017 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.
+ */
+#include "helpers.h"
+
+#if defined POOL_AVG
+#define POOL_OP(x, y) ((x) + (y))
+#else
+#define POOL_OP(x, y) (fmax((x), (y)))
+#endif
+
+float calculate_avg_scale(const int pool_size, const int upper_bound_w, const int upper_bound_h,
+                          const int pad_x, const int pad_y, const int stride_x, const int stride_y)
+{
+    int start_x = get_global_id(0) * stride_x - pad_x;
+    int start_y = get_global_id(1) * stride_y - pad_y;
+    int end_x   = min(start_x + pool_size, upper_bound_w);
+    int end_y   = min(start_y + pool_size, upper_bound_h);
+    return 1.f / ((end_y - start_y) * (end_x - start_x));
+}
+
+/** Performs a pooling function of pool size equal to 2.
+ *
+ * @note Pooling stride must be passed using -DPOOL_STRIDE e.g -DPOOL_STRIDE=2. Supported strides are 1,2,3
+ * @note Datatype must be passed using -DDATA_TYPE e.g. -DDATA_TYPE=float. Supported data types are F16, F32;
+ * @note In case of average pooling -DPOOL_AVG must be provided otherwise max pooling will be performed.
+ *
+ * @param[in]  input_ptr                            Pointer to the source image. Supported data types: F16, F32
+ * @param[in]  input_stride_x                       Stride of the source image in X dimension (in bytes)
+ * @param[in]  input_step_x                         input_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  input_stride_y                       Stride of the source image in Y dimension (in bytes)
+ * @param[in]  input_step_y                         input_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  input_stride_z                       Stride of the source tensor in Z dimension (in bytes)
+ * @param[in]  input_step_z                         input_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  input_offset_first_element_in_bytes  The offset of the first element in the source image
+ * @param[out] output_ptr                           Pointer to the destination image. Supported data types: F16, F32
+ * @param[in]  output_stride_x                      Stride of the destination image in X dimension (in bytes)
+ * @param[in]  output_step_x                        output_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  output_stride_y                      Stride of the destination image in Y dimension (in bytes)
+ * @param[in]  output_step_y                        output_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  output_stride_z                      Stride of the source tensor in Z dimension (in bytes)
+ * @param[in]  output_step_z                        output_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  output_offset_first_element_in_bytes The offset of the first element in the destination image
+ * @param[in]  max_dims                             The maximum index that can be accessed in x and y dimension (width + pad)
+ * @param[in]  strides                              The pooling operation strides in each dimension
+ * @param[in]  paddings                             The pooling operation paddings in each dimension
+ */
+__kernel void pooling_layer_2(
+    TENSOR3D_DECLARATION(input),
+    TENSOR3D_DECLARATION(output)
+#ifdef POOL_AVG
+    ,
+    int2 max_dims, int2 strides, int2 paddings
+#endif
+)
+{
+    // Get pixels pointer
+    Tensor3D input  = CONVERT_TO_TENSOR3D_STRUCT(input);
+    Tensor3D output = CONVERT_TO_TENSOR3D_STRUCT(output);
+
+    // Load data
+    VEC_DATA_TYPE(DATA_TYPE, 2)
+    data0 = vload2(0, (__global DATA_TYPE *)tensor3D_offset(&input, 0, 0, 0));
+    VEC_DATA_TYPE(DATA_TYPE, 2)
+    data1 = vload2(0, (__global DATA_TYPE *)tensor3D_offset(&input, 0, 1, 0));
+
+    // Perform calculations
+    data0         = POOL_OP(data0, data1);
+    DATA_TYPE res = POOL_OP(data0.s0, data0.s1);
+
+    // Divide by 4 in case of average pooling
+#ifdef POOL_AVG
+    res *= calculate_avg_scale(2, max_dims.x, max_dims.y, paddings.x, paddings.y, strides.x, strides.y);
+#endif
+
+    // Store result
+    *(__global DATA_TYPE *)output.ptr = res;
+}
+
+/** Performs a pooling function of pool size equal to 3.
+ *
+ * @note Pooling stride must be passed using -DPOOL_STRIDE e.g -DPOOL_STRIDE=2. Supported strides are 1,2,3
+ * @note Datatype must be passed using -DDATA_TYPE e.g. -DDATA_TYPE=float. Supported data types are F16, F32;
+ * @note In case of average pooling -DPOOL_AVG must be provided otherwise max pooling will be performed.
+ *
+ * @param[in]  input_ptr                            Pointer to the source image. Supported data types: F16, F32
+ * @param[in]  input_stride_x                       Stride of the source image in X dimension (in bytes)
+ * @param[in]  input_step_x                         input_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  input_stride_y                       Stride of the source image in Y dimension (in bytes)
+ * @param[in]  input_step_y                         input_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  input_stride_z                       Stride of the source tensor in Z dimension (in bytes)
+ * @param[in]  input_step_z                         input_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  input_offset_first_element_in_bytes  The offset of the first element in the source image
+ * @param[out] output_ptr                           Pointer to the destination image. Supported data types: F16, F32
+ * @param[in]  output_stride_x                      Stride of the destination image in X dimension (in bytes)
+ * @param[in]  output_step_x                        output_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  output_stride_y                      Stride of the destination image in Y dimension (in bytes)
+ * @param[in]  output_step_y                        output_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  output_stride_z                      Stride of the source tensor in Z dimension (in bytes)
+ * @param[in]  output_step_z                        output_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  output_offset_first_element_in_bytes The offset of the first element in the destination image
+ * @param[in]  max_dims                             The maximum index that can be accessed in x and y dimension (width + pad)
+ * @param[in]  strides                              The pooling operation strides in each dimension
+ * @param[in]  paddings                             The pooling operation paddings in each dimension
+ */
+__kernel void pooling_layer_3(
+    TENSOR3D_DECLARATION(input),
+    TENSOR3D_DECLARATION(output)
+#ifdef POOL_AVG
+    ,
+    int2 max_dims, int2 strides, int2 paddings
+#endif
+)
+{
+    // Get pixels pointer
+    Tensor3D input  = CONVERT_TO_TENSOR3D_STRUCT(input);
+    Tensor3D output = CONVERT_TO_TENSOR3D_STRUCT(output);
+
+    // Load data
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    data0 = vload3(0, (__global DATA_TYPE *)tensor3D_offset(&input, 0, 0, 0));
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    data1 = vload3(0, (__global DATA_TYPE *)tensor3D_offset(&input, 0, 1, 0));
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    data2 = vload3(0, (__global DATA_TYPE *)tensor3D_offset(&input, 0, 2, 0));
+
+    // Perform calculations
+    data0         = POOL_OP(data0, data1);
+    data0         = POOL_OP(data0, data2);
+    DATA_TYPE res = POOL_OP(POOL_OP(data0.s0, data0.s1), data0.s2);
+
+    // Divide by 4 in case of average pooling
+#ifdef POOL_AVG
+    res *= calculate_avg_scale(3, max_dims.x, max_dims.y, paddings.x, paddings.y, strides.x, strides.y);
+#endif
+
+    // Store result
+    *(__global DATA_TYPE *)output.ptr = res;
+}