COMPMID-1050 CL/NEON: Create a function to convert the 2D weights of FC layer from NHWC to NCHW and viceversa

Change-Id: If77ffeb92b6eb883e5d2d2c97c2c4d1d23d17c8d
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/129257
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/src/core/NEON/kernels/NEConvertFullyConnectedWeightsKernel.cpp b/src/core/NEON/kernels/NEConvertFullyConnectedWeightsKernel.cpp
new file mode 100644
index 0000000..b3746bd
--- /dev/null
+++ b/src/core/NEON/kernels/NEConvertFullyConnectedWeightsKernel.cpp
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2018 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/NEON/kernels/NEConvertFullyConnectedWeightsKernel.h"
+
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/Types.h"
+
+using namespace arm_compute;
+
+NEConvertFullyConnectedWeightsKernel::NEConvertFullyConnectedWeightsKernel()
+    : _input(nullptr), _output(nullptr), _factor1(0), _factor2(0)
+{
+}
+
+void NEConvertFullyConnectedWeightsKernel::configure(const ITensor *input, ITensor *output, const TensorShape &original_input_shape,
+                                                     DataLayout data_layout)
+{
+    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output);
+    ARM_COMPUTE_ERROR_THROW_ON(NEConvertFullyConnectedWeightsKernel::validate(input->info(), output->info(), original_input_shape, data_layout));
+
+    _input  = input;
+    _output = output;
+
+    const unsigned int num_elems_per_input_plane = original_input_shape.x() * original_input_shape.y();
+    const unsigned int num_channels              = original_input_shape.z();
+
+    // Set build options
+    if(data_layout == DataLayout::NCHW)
+    {
+        _factor1 = num_elems_per_input_plane;
+        _factor2 = num_channels;
+    }
+    else
+    {
+        _factor1 = num_channels;
+        _factor2 = num_elems_per_input_plane;
+    }
+
+    // Configure kernel window
+    Window win = calculate_max_window(*input->info(), Steps());
+    INEKernel::configure(win);
+}
+
+Status NEConvertFullyConnectedWeightsKernel::validate(const ITensorInfo *input, const ITensorInfo *output, const TensorShape &original_input_shape,
+                                                      DataLayout data_layout)
+{
+    ARM_COMPUTE_RETURN_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8, DataType::S8, DataType::QS8, DataType::QASYMM8, DataType::U16, DataType::S16, DataType::QS16, DataType::U32, DataType::S32,
+                                                         DataType::QS32, DataType::F16, DataType::F32);
+    ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_DATA_TYPES(input, output);
+    ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_SHAPES(input, output);
+    ARM_COMPUTE_RETURN_ERROR_ON(input->num_dimensions() != 2);
+    ARM_COMPUTE_RETURN_ERROR_ON(input->dimension(1) != original_input_shape.total_size_lower(3));
+    ARM_COMPUTE_RETURN_ERROR_ON(data_layout == DataLayout::UNKNOWN);
+
+    return Status{};
+}
+
+template <typename T>
+void NEConvertFullyConnectedWeightsKernel::run_convert_fc_weights(const Window &window)
+{
+    const unsigned int dst_stride_x = _output->info()->strides_in_bytes().x();
+    const unsigned int dst_stride_y = _output->info()->strides_in_bytes().y();
+
+    Iterator input(_input, window);
+    Iterator output(_output, window);
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        *reinterpret_cast<T *>(output.ptr() + id.x() * dst_stride_x + (id.y() % _factor1 * _factor2 + id.y() / _factor1) * dst_stride_y) = *reinterpret_cast<T *>(input.ptr());
+    },
+    input);
+}
+
+void NEConvertFullyConnectedWeightsKernel::run(const Window &window, const ThreadInfo &info)
+{
+    ARM_COMPUTE_UNUSED(info);
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INEKernel::window(), window);
+
+    switch(_input->info()->element_size())
+    {
+        case 1:
+            run_convert_fc_weights<uint8_t>(window);
+            break;
+        case 2:
+            run_convert_fc_weights<uint16_t>(window);
+            break;
+        case 4:
+            run_convert_fc_weights<uint32_t>(window);
+            break;
+        default:
+            ARM_COMPUTE_ERROR("Data type not supported.");
+            break;
+    }
+}