COMPMID-1763 : NEON: Implement Gather

Change-Id: I9a3808315290bd395f5acce4530ab8daccddf8be
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/167195
Tested-by: bsgcomp <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/520
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Pablo Marquez <pablo.tello@arm.com>

1 files changed, 112 insertions, 0 deletions

diff --git a/arm_compute/core/NEON/kernels/NEGatherKernel.h b/arm_compute/core/NEON/kernels/NEGatherKernel.h
new file mode 100644
index 0000000000..667e9812d8
--- /dev/null
+++ b/arm_compute/core/NEON/kernels/NEGatherKernel.h
@@ -0,0 +1,112 @@
+/*
+ * 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_NEGATHERKERNEL_H__
+#define __ARM_COMPUTE_NEGATHERKERNEL_H__
+
+#include "arm_compute/core/NEON/INEKernel.h"
+#include "arm_compute/core/Types.h"
+
+namespace arm_compute
+{
+class ITensor;
+
+/** Kernel to perform other operation on NEON */
+class NEGatherKernel : public INEKernel
+{
+public:
+    /** Default constructor. */
+    NEGatherKernel();
+    /** Prevent instances of this class from being copied (As this class contains pointers). */
+    NEGatherKernel(const NEGatherKernel &) = delete;
+    /** Prevent instances of this class from being copied (As this class contains pointers). */
+    NEGatherKernel &operator=(const NEGatherKernel &) = delete;
+    /** Allow instances of this class to be moved. */
+    NEGatherKernel(NEGatherKernel &&) = default;
+    /** Allow instances of this class to be moved. */
+    NEGatherKernel &operator=(NEGatherKernel &&) = default;
+    /** Default detructor */
+    ~NEGatherKernel() = default;
+
+    /** Name of the kernel
+     *
+     * @return Kernel name
+     */
+    const char *name() const override
+    {
+        return "NEGatherKernel";
+    }
+    /** Initialise the kernel's inputs and outputs
+     *
+     * @param[in]  input   Source tensor. Supported tensor rank: up to 4. Data type supported: U8/S8/QASYMM8/U16/S16/U32/S32/F16/F32
+     * @param[in]  indices Indices tensor. Supported tensor rank: up to 1. Must be one of the following type: U32/S32. Each value Must be in range [0, input.shape[@p axis])
+     * @param[out] output  Destination tensor. Data type supported: Same as @p input
+     * @param[in]  axis    (Optional) The axis in @p input to gather @p indices from. Negative values wrap around. Defaults to 0
+     */
+    void configure(const ITensor *input, const ITensor *indices, ITensor *output, int axis = 0);
+    /** Static function to check if given info will lead to a valid configuration of @ref NEGatherKernel
+     *
+     * @param[in] input   Source tensor info. Supported tensor rank: up to 4. Data type supported: U8/S8/QASYMM8/U16/S16/U32/S32/F16/F32
+     * @param[in] indices Indices tensor info. Supported tensor rank: up to 1. Must be one of the following type: U32/S32. Each value Must be in range [0, input.shape[@p axis])
+     * @param[in] output  Destination tensor info. Data type supported: Same as @p input
+     * @param[in] axis    (Optional) The axis in @p input to gather @p indices from. Negative values wrap around. Defaults to 0
+     *
+     * @return a status
+     */
+    static Status validate(const ITensorInfo *input, const ITensorInfo *indices, const ITensorInfo *output, int axis);
+
+    // Inherited methods overridden:
+    void run(const Window &window, const ThreadInfo &info) override;
+
+private:
+    /** Implementation of the gather operation for 0 axis.
+     *
+     * For gather on the 0 axis an element by element copy is performed.
+     *
+     * @param[in] window Region on which to execute the kernel. (Must be a region of the window returned by window())
+     * @param[in] info   Info about executing thread and CPU.
+     */
+    template <typename U>
+    void gather_0_axis(const Window &window, const ThreadInfo &info);
+
+    /** Implementation of the gather operation.
+     *
+     * For 1<=axis a row-wise copy is taking place.
+     *
+     * @param[in] window Region on which to execute the kernel. (Must be a region of the window returned by window())
+     * @param[in] info   Info about executing thread and CPU.
+     */
+    template <typename U>
+    void gather_n_axis(const Window &window, const ThreadInfo &info);
+
+    using kernel_ptr = void (NEGatherKernel::*)(const Window &window, const ThreadInfo &info);
+
+    const ITensor *_input;
+    const ITensor *_indices;
+    int            _axis;
+    ITensor       *_output;
+    kernel_ptr     _func;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_NEGATHERKERNEL_H__ */