COMPMID-452 CL Generic Depthwise Convolution implementation.

Change-Id: I115e48fe6ce5e281f3791aa5d80fdc754cdd2b5e
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/85082
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
diff --git a/src/core/CL/kernels/CLDepthwiseConvolution3x3Kernel.cpp b/src/core/CL/kernels/CLDepthwiseConvolution3x3Kernel.cpp
new file mode 100644
index 0000000..c10e6be
--- /dev/null
+++ b/src/core/CL/kernels/CLDepthwiseConvolution3x3Kernel.cpp
@@ -0,0 +1,120 @@
+/*
+ * 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 "arm_compute/core/CL/kernels/CLDepthwiseConvolution3x3Kernel.h"
+
+#include "arm_compute/core/AccessWindowStatic.h"
+#include "arm_compute/core/CL/CLHelpers.h"
+#include "arm_compute/core/CL/CLKernelLibrary.h"
+#include "arm_compute/core/CL/ICLKernel.h"
+#include "arm_compute/core/CL/ICLTensor.h"
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/Utils.h"
+
+using namespace arm_compute;
+
+CLDepthwiseConvolution3x3Kernel::CLDepthwiseConvolution3x3Kernel()
+    : _border_size(0), _input(), _output(), _weights(), _conv_stride_x(0), _conv_stride_y(0), _conv_pad_x(0), _conv_pad_y(0)
+{
+}
+
+BorderSize CLDepthwiseConvolution3x3Kernel::border_size() const
+{
+    return _border_size;
+}
+
+void CLDepthwiseConvolution3x3Kernel::configure(const ICLTensor *input, ICLTensor *output, const ICLTensor *weights, const PadStrideInfo &conv_info)
+{
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::F32);
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::F32);
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(weights, 1, DataType::F32);
+    ARM_COMPUTE_ERROR_ON(weights->info()->dimension(0) != 3 || weights->info()->dimension(1) != 3);
+
+    _input         = input;
+    _output        = output;
+    _weights       = weights;
+    _conv_stride_x = conv_info.stride().first;
+    _conv_stride_y = conv_info.stride().second;
+    _border_size   = BorderSize(weights->info()->dimension(1) / 2, weights->info()->dimension(0) / 2);
+    _conv_pad_x    = std::min(border_size().right, conv_info.pad().first);
+    _conv_pad_y    = std::min(border_size().bottom, conv_info.pad().second);
+
+    // Set build options
+    std::set<std::string> options;
+
+    options.emplace("-DCONV_STRIDE_X=" + support::cpp11::to_string(_conv_stride_x));
+
+    _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("depthwise_convolution_3x3", options));
+
+    // Configure kernel window
+    const unsigned int num_elems_processed_per_iteration = 2;
+    const unsigned int num_elems_written_per_iteration   = 2;
+    const unsigned int num_elems_read_per_iteration      = (_conv_stride_x == 1) ? 4 : (_conv_stride_x == 2) ? 5 : 6;
+    const unsigned int num_rows_read_per_iteration       = 3;
+
+    Window win = calculate_max_window(*output->info(), Steps(num_elems_processed_per_iteration));
+
+    const int access_right  = border_size().left + ceil_to_multiple(border_size().left + input->info()->dimension(0), num_elems_read_per_iteration);
+    const int access_bottom = border_size().bottom + ceil_to_multiple(border_size().bottom + input->info()->dimension(1), num_rows_read_per_iteration);
+
+    AccessWindowStatic     input_access(input->info(), -border_size().left, -border_size().bottom, access_right, access_bottom);
+    AccessWindowHorizontal output_access(output->info(), 0, num_elems_written_per_iteration);
+    AccessWindowStatic     weights_access(weights->info(), 0, 0, weights->info()->dimension(0), weights->info()->dimension(1));
+
+    update_window_and_padding(win, input_access, weights_access, output_access);
+
+    output_access.set_valid_region(win, ValidRegion(Coordinates(), output->info()->tensor_shape()));
+
+    ICLKernel::configure(win);
+}
+
+void CLDepthwiseConvolution3x3Kernel::run(const Window &window, cl::CommandQueue &queue)
+{
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(IKernel::window(), window);
+
+    Window slice_in      = window.first_slice_window_3D();
+    Window slice_out     = window.first_slice_window_3D();
+    Window slice_weights = window.first_slice_window_3D();
+
+    slice_in.adjust(Window::DimX, -_conv_pad_x, true);
+    slice_in.adjust(Window::DimY, -_conv_pad_y, true);
+    slice_in.set_dimension_step(Window::DimX, window.x().step() * _conv_stride_x);
+    slice_in.set_dimension_step(Window::DimY, window.y().step() * _conv_stride_y);
+    slice_weights.set_dimension_step(Window::DimX, 0);
+    slice_weights.set_dimension_step(Window::DimY, 0);
+
+    do
+    {
+        unsigned int idx = 0;
+        add_3D_tensor_argument(idx, _input, slice_in);
+        add_3D_tensor_argument(idx, _output, slice_out);
+        add_3D_tensor_argument(idx, _weights, slice_weights);
+
+        enqueue(queue, *this, slice_out);
+    }
+    while(window.slide_window_slice_3D(slice_out));
+}