COMPMID-1772: Implement PadV2 for NEON

Change-Id: Ia4604524a034c46b004fd850183480c5fbfd8cb3
Reviewed-on: https://review.mlplatform.org/437
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
diff --git a/src/runtime/NEON/functions/NEPadLayer.cpp b/src/runtime/NEON/functions/NEPadLayer.cpp
new file mode 100644
index 0000000..f5c2718
--- /dev/null
+++ b/src/runtime/NEON/functions/NEPadLayer.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2018-2019 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/runtime/NEON/functions/NEPadLayer.h"
+
+#include "arm_compute/runtime/NEON/NEScheduler.h"
+
+#include "arm_compute/core/ITensor.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+
+#include "support/ToolchainSupport.h"
+
+namespace arm_compute
+{
+namespace
+{
+TensorInfo get_expected_output_tensorinfo(const ITensorInfo &input, const PaddingList &paddings)
+{
+    const TensorShape expected_output_shape = arm_compute::misc::shape_calculator::compute_padded_shape(input.tensor_shape(), paddings);
+    const TensorInfo  expected_output_info  = input.clone()->set_tensor_shape(expected_output_shape);
+    return expected_output_info;
+}
+
+Status validate_arguments(const ITensorInfo &input, ITensorInfo &output, const PaddingList &paddings)
+{
+    const TensorInfo expected_output_info = get_expected_output_tensorinfo(input, paddings);
+    auto_init_if_empty(output, expected_output_info);
+    ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_SHAPES(&output, &expected_output_info);
+
+    return Status{};
+}
+
+Coordinates get_subtensor_coords(const PaddingList &paddings)
+{
+    Coordinates coords;
+    for(unsigned int i = 0; i < paddings.size(); ++i)
+    {
+        coords.set(i, paddings[i].first);
+    }
+
+    return coords;
+}
+} // namespace
+
+NEPadLayer::NEPadLayer()
+    : _memset_kernel(), _copy_kernel(), _output_subtensor()
+{
+}
+
+void NEPadLayer::configure(ITensor *input, ITensor *output, const PaddingList &padding, PixelValue constant_value)
+{
+    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output);
+    ARM_COMPUTE_THROW_ON_ERROR(NEPadLayer::validate(input->info(), output->info(), padding, constant_value));
+
+    // Auto-init
+    auto_init_if_empty(*output->info(), get_expected_output_tensorinfo(*input->info(), padding));
+
+    // Create SubTensor (Can use sub-tensor as the kernels to be executed do not require padding)
+    _output_subtensor = SubTensor(output, input->info()->tensor_shape(), get_subtensor_coords(padding), true);
+
+    // Set the pages of the output to the specified value
+    _memset_kernel.configure(output, constant_value);
+
+    // Copy the input to the output
+    _copy_kernel.configure(input, &_output_subtensor);
+}
+
+Status NEPadLayer::validate(const ITensorInfo *input, const ITensorInfo *output, const PaddingList &padding, PixelValue constant_value)
+{
+    ARM_COMPUTE_UNUSED(constant_value);
+    ARM_COMPUTE_RETURN_ERROR_ON_NULLPTR(input, output);
+
+    auto output_clone = output->clone();
+
+    SubTensorInfo output_subtensor_info(output_clone.get(), input->tensor_shape(), get_subtensor_coords(padding), true);
+    ARM_COMPUTE_RETURN_ON_ERROR(validate_arguments(*input, *output_clone, padding));
+    ARM_COMPUTE_RETURN_ON_ERROR(NECopyKernel::validate(input, &output_subtensor_info));
+
+    return Status{};
+}
+
+void NEPadLayer::run()
+{
+    NEScheduler::get().schedule(&_memset_kernel, Window::DimY);
+    NEScheduler::get().schedule(&_copy_kernel, Window::DimY);
+}
+} // namespace arm_compute