Move CPU/GPU files from Core/Runtime to the respective backend folders

Legacy structure contained two libraries core/runtime with two backends
in each.
We reduce the core/runtime libraries to a single library thus merging
the backend files

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I69545765fe7a730368105cdbd067d3135ec7a174
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6155
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/cpu/operators/CpuDirectConv2d.h b/src/cpu/operators/CpuDirectConv2d.h
new file mode 100644
index 0000000..fa8d61e
--- /dev/null
+++ b/src/cpu/operators/CpuDirectConv2d.h
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2021 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.
+ */
+#ifndef ARM_COMPUTE_CPU_DIRECTCONV2D_H
+#define ARM_COMPUTE_CPU_DIRECTCONV2D_H
+
+#include "arm_compute/core/ITensorInfo.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/experimental/Types.h"
+#include "arm_compute/runtime/IMemoryManager.h"
+#include "arm_compute/runtime/MemoryGroup.h"
+#include "arm_compute/runtime/NEON/functions/NEActivationLayer.h"
+#include "arm_compute/runtime/Tensor.h"
+#include "src/core/NEON/kernels/NEFillBorderKernel.h"
+#include "src/cpu/ICpuKernel.h"
+#include "src/cpu/ICpuOperator.h"
+#include "src/cpu/kernels/CpuDirectConv2dKernel.h"
+#include "src/cpu/kernels/CpuDirectConv2dOutputStageKernel.h"
+#include "src/cpu/operators/CpuActivation.h"
+
+#include <memory>
+
+namespace arm_compute
+{
+namespace cpu
+{
+/** Function to run the direct convolution.
+ *
+ *  This function calls the following kernels:
+ *
+ * -# @ref NEFillBorderKernel for the input
+ * -# @ref kernels::CpuDirectConv2dOutputStageKernel
+ * -# @ref kernels::CpuDirectConv2dKernel
+ */
+class CpuDirectConv2d : public ICpuOperator
+{
+public:
+    CpuDirectConv2d(std::shared_ptr<IMemoryManager> memory_manager = nullptr);
+    ~CpuDirectConv2d();
+    /** Set the input, weights, biases and output tensors.
+     *
+     * @note: DirectConvolution only works in the following configurations:
+     *    1x1 convolution with stride_x = 1/2/3, stride_y = 1/2/3 data type = F16/F32
+     *    3x3 convolution with stride_x = 1/2/3, stride_y = 1/2/3 data type = F16/F32
+     *    5x5 convolution with stride_x = 1/2/3, stride_y = 1/2/3 data type = F32
+     *
+     * @param[in, out] src       Input tensor info. Data types supported: F16/F32.
+     * @param[in]      weights   Set of kernels to convolve the input volume.
+     *                           Supported sizes: 1x1, 3x3 and 5x5.
+     *                           The 3rd dimension must be the same as the input's volume 3rd dimension.
+     *                           Data type supported: Same as @p src.
+     * @param[in]      bias      Set of biases. Can be nullptr. Data type supported: Same as @p src.
+     * @param[out]     dst       Output tensor info.
+     *                           The 3rd dimensions must be equal to the 4th dimension of the @p kernels tensor. Data types supported: Same as @p input.
+     * @param[in]      conv_info Contains padding and stride information described in @ref PadStrideInfo.
+     * @param[in]      act_info  (Optional) Activation layer information in case of a fused activation.
+     */
+    void configure(ITensorInfo *src, ITensorInfo *weights, const ITensorInfo *bias, ITensorInfo *dst, const PadStrideInfo &conv_info, const ActivationLayerInfo &act_info = ActivationLayerInfo());
+    /** Static function to check if given info will lead to a valid configuration
+     *
+     * Similar to CpuDirectConv2d::configure()
+     *
+     * @return a status
+     */
+    static Status validate(const ITensorInfo *src, const ITensorInfo *weights, const ITensorInfo *bias, const ITensorInfo *dst, const PadStrideInfo &conv_info,
+                           const ActivationLayerInfo &act_info = ActivationLayerInfo());
+
+    // Inherited methods overridden:
+    void run(ITensorPack &tensors) override;
+
+private:
+    MemoryGroup                                                _memory_group;
+    std::unique_ptr<kernels::CpuDirectConv2dOutputStageKernel> _output_stage_kernel;
+    std::unique_ptr<kernels::CpuDirectConv2dKernel>            _conv_kernel;
+    std::unique_ptr<NEFillBorderKernel>                        _input_border_handler;
+    std::unique_ptr<CpuActivation>                             _activationlayer_function;
+    Tensor                                                     _accumulator;
+    bool                                                       _has_bias{ false };
+    bool                                                       _is_activationlayer_enabled{ false };
+    unsigned int                                               _dim_split{ 0 };
+    bool                                                       _is_padding_required{ false };
+};
+} // namespace cpu
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_CPU_DIRECTCONV2D_H */