COMPMID-1574 Implement ReduceMean in OpenCL

Change-Id: Id331199f569f52a37280a9ada5bf84694580b93c
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/152843
Tested-by: bsgcomp <bsgcomp@arm.com>
Reviewed-by: Michele DiGiorgio <michele.digiorgio@arm.com>
diff --git a/arm_compute/runtime/CL/functions/CLReduceMean.h b/arm_compute/runtime/CL/functions/CLReduceMean.h
new file mode 100644
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+++ b/arm_compute/runtime/CL/functions/CLReduceMean.h
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+/*
+ * 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.
+ */
+#ifndef __ARM_COMPUTE_CL_REDUCE_MEAN_H__
+#define __ARM_COMPUTE_CL_REDUCE_MEAN_H__
+
+#include "arm_compute/runtime/CL/ICLSimpleFunction.h"
+#include "arm_compute/runtime/CL/functions/CLArithmeticDivision.h"
+#include "arm_compute/runtime/CL/functions/CLReductionOperation.h"
+#include "arm_compute/runtime/CL/functions/CLReshapeLayer.h"
+#include "arm_compute/runtime/IMemoryManager.h"
+
+namespace arm_compute
+{
+// Forward Declarations
+class ICLTensor;
+
+/** Basic function to perform reduce operation */
+class CLReduceMean : public IFunction
+{
+public:
+    /** Default constructor */
+    CLReduceMean(std::shared_ptr<IMemoryManager> memory_manager = nullptr);
+    /** Configure kernel
+     *
+     * @note Supported tensor rank: up to 4
+     *
+     * @param[in]  input          Source tensor. Data type supported: QASYMM8/F16/F32
+     * @param[in]  reduction_axis Reduction axis vector.
+     * @param[in]  keep_dims      If positive, retains reduced dimensions with length 1.
+     * @param[out] output         Destination tensor. Data type supported: Same as @p input
+     */
+    void configure(ICLTensor *input, const Coordinates &reduction_axis, bool keep_dims, ICLTensor *output);
+
+    /** Static function to check if given info will lead to a valid configuration of @ref CLReduceMean
+     *
+     * @param[in] input          Source tensor. Data type supported: QASYMM8/F16/F32
+     * @param[in] reduction_axis Reduction axis vector.
+     * @param[in] keep_dims      If positive, retains reduced dimensions with length 1.
+     * @param[in] output         Destination tensor. Data type supported: Same as @p input
+     *
+     * @return A status
+     */
+    static Status validate(const ITensorInfo *input, const Coordinates &reduction_axis, bool keep_dims, const ITensorInfo *output);
+
+    // Inherited methods overridden:
+    void run() override;
+
+private:
+    CLMemoryGroup                           _memory_group;
+    std::unique_ptr<CLReductionOperation[]> _reduction_kernels{ nullptr };
+    std::unique_ptr<CLTensor[]>             _reduced_outs{ nullptr };
+    CLReshapeLayer                          _reshape;
+    unsigned int                            _reduction_ops;
+    bool                                    _keep_dims;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_CL_REDUCE_MEAN_H__ */