COMPMID-1728 CL: Implement ArgMax/ArgMin

Change-Id: I7eae2e55cc0b0b7bbebb7617299daaca6f75f40c
Reviewed-on: https://review.mlplatform.org/292
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/arm_compute/core/Types.h b/arm_compute/core/Types.h
index 5ddd207..7db2f5f 100644
--- a/arm_compute/core/Types.h
+++ b/arm_compute/core/Types.h
@@ -545,9 +545,11 @@
 /** Available reduction operations */
 enum class ReductionOperation
 {
-    SUM_SQUARE, /**< Sum of squares */
-    SUM,        /**< Sum */
-    MEAN_SUM,   /**< Mean of sum */
+    SUM_SQUARE,  /**< Sum of squares */
+    SUM,         /**< Sum */
+    MEAN_SUM,    /**< Mean of sum */
+    ARG_IDX_MAX, /**< Index of the max value */
+    ARG_IDX_MIN  /**< Index of the min value */
 };
 
 /** The normalization type used for the normalization layer */
diff --git a/arm_compute/runtime/CL/CLFunctions.h b/arm_compute/runtime/CL/CLFunctions.h
index d9b29ff..780597e 100644
--- a/arm_compute/runtime/CL/CLFunctions.h
+++ b/arm_compute/runtime/CL/CLFunctions.h
@@ -28,6 +28,7 @@
 #include "arm_compute/runtime/CL/functions/CLAbsoluteDifference.h"
 #include "arm_compute/runtime/CL/functions/CLAccumulate.h"
 #include "arm_compute/runtime/CL/functions/CLActivationLayer.h"
+#include "arm_compute/runtime/CL/functions/CLArgMinMaxLayer.h"
 #include "arm_compute/runtime/CL/functions/CLArithmeticAddition.h"
 #include "arm_compute/runtime/CL/functions/CLArithmeticDivision.h"
 #include "arm_compute/runtime/CL/functions/CLArithmeticSubtraction.h"
diff --git a/arm_compute/runtime/CL/functions/CLArgMinMaxLayer.h b/arm_compute/runtime/CL/functions/CLArgMinMaxLayer.h
new file mode 100644
index 0000000..b3a8594
--- /dev/null
+++ b/arm_compute/runtime/CL/functions/CLArgMinMaxLayer.h
@@ -0,0 +1,59 @@
+/*
+ * 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_CLARGMINMAXLAYER_H__
+#define __ARM_COMPUTE_CLARGMINMAXLAYER_H__
+
+#include "arm_compute/core/CL/kernels/CLReductionOperationKernel.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/runtime/CL/ICLSimpleFunction.h"
+
+namespace arm_compute
+{
+class ICLTensor;
+
+/** Function to calculate the index of the minimum or maximum values in a tensor based on an axis. */
+class CLArgMinMaxLayer : public ICLSimpleFunction
+{
+public:
+    /** Set the input and output tensors.
+     *
+     * @param[in]  input  Input source tensor. Data types supported: F16/F32.
+     * @param[in]  axis   Axis to find max/min index.
+     * @param[out] output Output source tensor. Data types supported: U32.
+     * @param[in]  op     Operation to perform: min or max
+     */
+    void configure(const ICLTensor *input, int axis, ICLTensor *output, const ReductionOperation &op);
+    /** Static function to check if given info will lead to a valid configuration of @ref CLArgMinMaxLayer
+     *
+     * @param[in] input  Input source tensor info. Data types supported: F16/F32.
+     * @param[in] axis   Axis to find max/min index.
+     * @param[in] output Output source tensor info. Data types supported: U32.
+     * @param[in] op     Operation to perform: min or max
+     *
+     * @return a status
+     */
+    static Status validate(const ITensorInfo *input, int axis, const ITensorInfo *output, const ReductionOperation &op);
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_CLARGMINMAXLAYER_H__ */