COMPMID-2387: Add support for NEMeanStdDevNormalizationLayer

Change-Id: If5a9558b78f9c696dfc72633f73e9e21e5c2970f
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1351
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Pablo Marquez <pablo.tello@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/arm_compute/core/NEON/kernels/NEMeanStdDevNormalizationKernel.h b/arm_compute/core/NEON/kernels/NEMeanStdDevNormalizationKernel.h
new file mode 100644
index 0000000..ba5410a
--- /dev/null
+++ b/arm_compute/core/NEON/kernels/NEMeanStdDevNormalizationKernel.h
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 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.
+ */
+#ifndef __ARM_COMPUTE_NEMEANSTDDEVNORMALIZATIONKERNEL_H__
+#define __ARM_COMPUTE_NEMEANSTDDEVNORMALIZATIONKERNEL_H__
+
+#include "arm_compute/core/NEON/INEKernel.h"
+
+#ifdef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+#include <arm_fp16.h>
+#endif /* __ARM_FEATURE_FP16_VECTOR_ARITHMETIC */
+
+namespace arm_compute
+{
+class ITensor;
+
+/** Interface for the kernel to normalize the input 2D tensor across the first dimension with respect to mean and standard deviation of the same dimension. */
+class NEMeanStdDevNormalizationKernel : public INEKernel
+{
+public:
+    const char *name() const override
+    {
+        return "NEMeanStdDevNormalizationKernel";
+    }
+    /** Default constructor */
+    NEMeanStdDevNormalizationKernel();
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    NEMeanStdDevNormalizationKernel(const NEMeanStdDevNormalizationKernel &) = delete;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    NEMeanStdDevNormalizationKernel &operator=(const NEMeanStdDevNormalizationKernel &) = delete;
+    /** Allow instances of this class to be moved */
+    NEMeanStdDevNormalizationKernel(NEMeanStdDevNormalizationKernel &&) = default;
+    /** Allow instances of this class to be moved */
+    NEMeanStdDevNormalizationKernel &operator=(NEMeanStdDevNormalizationKernel &&) = default;
+    /** Default destructor */
+    ~NEMeanStdDevNormalizationKernel() = default;
+    /** Initialise the kernel's input and outputs.
+     *
+     * @note If the output tensor is a nullptr, the normalization will be performed in-place.
+     *
+     * @param[in, out] input   Source tensor with 2 dimensions. In case of @p output tensor = nullptr,
+     *                         this tensor will store the result of the normalization. Data types supported: F16/F32.
+     * @param[out]     output  (Optional) Destination tensor. It can be nullptr in case of in-place computation. Data type supported: same as @p input
+     * @param[in]      epsilon (Optional) Small float to avoid division by zero in case of zero standard deviation. Defaults to 1e-8.
+     */
+    void configure(ITensor *input, ITensor *output = nullptr, float epsilon = 1e-8f);
+    /** Static function to check if given info will lead to a valid configuration of @ref NEMeanStdDevNormalizationKernel
+     *
+     * @param[in] input   Source tensor info with 2 dimensions. In case of @p output tensor info = nullptr,
+     *                    this tensor will store the result of the normalization. Data types supported: F16/F32.
+     * @param[in] output  (Optional) Destination tensor info. It can be nullptr in case of in-place computation. Data type supported: same as @p input
+     * @param[in] epsilon (Optional) Small float to avoid division by zero in case of zero standard deviation. Defaults to 1e-8.
+     *
+     * @return a status
+     */
+    static Status validate(const ITensorInfo *input, const ITensorInfo *output = nullptr, float epsilon = 1e-8f);
+
+    // Inherited methods overridden:
+    void run(const Window &window, const ThreadInfo &info) override;
+
+private:
+    /** Normalizes the input with respect to mean and standard deviation.
+     *
+     * @param[in] window Region on which to execute the kernel.
+     */
+    template <typename ScalarType, int size>
+    void mean_stddev_normalization(const Window &window);
+
+    ITensor *_input;
+    ITensor *_output;
+    float    _epsilon;
+
+    using MeanStdDevNormFunction = void (NEMeanStdDevNormalizationKernel::*)(const Window &window);
+
+    MeanStdDevNormFunction _func;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_NEMEANSTDDEVNORMALIZATIONKERNEL_H__ */