src/gpu/cl/kernels/ClGemmLowpQuantizeDownInt32ScaleByFixedPointKernel.h

/*
 * Copyright (c) 2020-2021 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
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 * 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
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#ifndef ARM_COMPUTE_CL_GEMMLOWP_QUANTIZEDOWN_INT32_SCALE_BY_FIXEDPOINT_KERNEL_H
#define ARM_COMPUTE_CL_GEMMLOWP_QUANTIZEDOWN_INT32_SCALE_BY_FIXEDPOINT_KERNEL_H

#include "src/core/common/Macros.h"
#include "src/gpu/cl/ClCompileContext.h"
#include "src/gpu/cl/IClKernel.h"

namespace arm_compute
{
namespace opencl
{
namespace kernels
{
/** OpenCL kernel used to quantize down the int32 accumulator values of GEMMLowp to QASYMM8/QASYMM8_SIGNED/QSYMM16
 *
 * This kernel takes a final int32 accumulator value (the output of the matrix multiplication), and processes it to obtain the final quantized value.
 * The following computations will be performed by the kernel:
 *
 *  -# Compute fixed point multiplication between each entry of input by gemmlowp_multiplier
 *  -# Add bias to final result if bias tensor is not a nullptr
 *  -# Round to nearest division by a power-of-two using result_shift
 *  -# Add offset to each result
 *  -# Clamp the value between the specified min and max bounds
 *  -# Clamp the resulting int32 values to the proper quantized range and cast to QASYMM8/QASYMM8_SIGNED/QSYMM16.
 */
class ClGemmLowpQuantizeDownInt32ScaleByFixedPointKernel : public IClKernel
{
public:
    ClGemmLowpQuantizeDownInt32ScaleByFixedPointKernel();
    ARM_COMPUTE_DISALLOW_COPY_ALLOW_MOVE(ClGemmLowpQuantizeDownInt32ScaleByFixedPointKernel);
    /** Initialise the kernel's source and destination.
     *
     * @param[in]  compile_context The compile context to be used.
     * @param[in]  src             Source tensor. Data type supported: S32
     * @param[in]  bias            Biases tensor. Only shared biases supported and it can be a nullptr if the biases addition is not required.
     *                             Biases are 1D tensor with dimensions [OFM]. Data type supported: Same as @p src.
     * @param[out] dst             Destination tensor. Data type supported: Data type supported: QASYMM8/QASYMM8_SIGNED/QSYMM16.
     * @param[in]  info            Output stage info. Used to pass the quantized output data type
     */
    void configure(const CLCompileContext &compile_context, const ITensorInfo *src, const ITensorInfo *bias, ITensorInfo *dst, const GEMMLowpOutputStageInfo *info);
    /** Static function to check if given info will lead to a valid configuration
     *
     * Similar to @ref ClGemmLowpQuantizeDownInt32ScaleByFixedPointKernel::configure()
     *
     * @return a status
     */
    static Status validate(const ITensorInfo *src, const ITensorInfo *bias, const ITensorInfo *dst, const GEMMLowpOutputStageInfo *info);

    // Inherited methods overridden:
    void run_op(ITensorPack &tensors, const Window &window, cl::CommandQueue &queue) override;
};
} // namespace kernels
} // namespace opencl
} // namespace arm_compute
#endif /* ARM_COMPUTE_CL_GEMMLOWP_QUANTIZEDOWN_INT32_SCALE_BY_FIXEDPOINT_KERNEL_H */