text: /*
   * Copyright (c) 2017-2022 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_CPU_GEMMLOWP_QUANTIZEDOWN_INT32TOUINT8_SCALEBYFIXEDPOINT_KERNEL_H
  #define ARM_COMPUTE_CPU_GEMMLOWP_QUANTIZEDOWN_INT32TOUINT8_SCALEBYFIXEDPOINT_KERNEL_H
  
  #include "arm_compute/core/KernelDescriptors.h"
  #include "src/core/common/Macros.h"
  #include "src/cpu/ICpuKernel.h"
  
  namespace arm_compute
  {
  // Forward declaration
  class ITensor;
  namespace cpu
  {
  namespace kernels
  {
  /** Kernel used to quantize down the int32 accumulator values of GEMMLowp to QASYMM8
   *
   * This kernel takes a final int32 accumulator value (the output of @ref CpuGemmLowpMatrixMultiplyKernel), and processes it to obtain the final QASYMM8 value.
   * The following computations will be performed by the kernel:
   *
   *  -# Compute fixed point multiplication between each entry of input by result_fixedpoint_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 [0..255] range and cast to QASYMM8.
   *
   */
  class CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel : public ICpuKernel<CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel>
  {
  public:
      CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel() = default;
      ARM_COMPUTE_DISALLOW_COPY_ALLOW_MOVE(CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel);
      /** Initialise the kernel's input and output.
       *
       * @param[in]  src                          Input tensor info. Data type supported: S32
       * @param[in]  bias                         Biases tensor info. 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 input.
       * @param[out] dst                          Output tensor info. Data type supported: Data type supported: QASYMM8
       * @param[in]  result_fixedpoint_multiplier Fixed point value to be multiplied to each element of the input matrix when once the result_offset has been add
       * @param[in]  result_shift                 Integer value used to round to nearest division by a power-of-two the result after the fixed point multiplication
       * @param[in]  result_offset_after_shift    Offset to be applied to result before converting it back to QASYMM8
       * @param[in]  min                          (Optional) Min value used to saturate down the output result before converting back to QASYMM8
       * @param[in]  max                          (Optional) Max value used to saturate up the output result before converting back to QASYMM8,
       *                                          Along with @p min, this value can be used to implement "rectified linear unit" activation functions
       */
      void configure(ITensorInfo *src, ITensorInfo *bias, ITensorInfo *dst, int result_fixedpoint_multiplier, int result_shift, int result_offset_after_shift, int min = 0, int max = 0);
      /** Static function to check if given info will lead to a valid configuration
       *
       * Similar to CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel::configure()
       *
       * @return a status
       */
      static Status validate(const ITensorInfo *src, const ITensorInfo *bias, const ITensorInfo *dst, int min = 0, int max = 0);
  
      // Inherited methods overridden:
      void run_op(ITensorPack &tensors, const Window &window, const ThreadInfo &info) override;
      const char *name() const override;
  
  private:
      /** Template function to run the CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel
       *
       * @param[in] window Region on which to execute the kernel. (Must be a valid region of the window returned by window()).
       */
      template <bool is_bounded_relu>
      void run_internal(const ITensor *src, const ITensor *bias, ITensor *dst, const Window &window);
  
      /** Common signature for all the specialised CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel functions
       *
       * @param[in] window Region on which to execute the kernel.
       */
      using QuantizeDownFunctionPtr = void (CpuGemmLowpQuantizeDownInt32ToUint8ScaleByFixedPointKernel::*)(
                                          const ITensor *src, const ITensor *bias, ITensor *dst, const Window &window);
  
      QuantizeDownFunctionPtr _func{ nullptr };
      int                     _result_fixedpoint_multiplier{ 0 };
      int                     _result_shift{ 0 };
      int                     _result_offset_after_shift{ 0 };
      int                     _min{ 0 };
      int                     _max{ 0 };
  };
  } // namespace kernels
  } // namespace cpu
  } // namespace arm_compute
  #endif /* ARM_COMPUTE_CPU_GEMMLOWP_QUANTIZEDOWN_INT32TOUINT8_SCALEBYFIXEDPOINT_KERNEL_H */
  