text: /*
   * Copyright (c) 2016-2019 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.
   */
  #include "arm_compute/core/NEON/kernels/NETableLookupKernel.h"
  
  #include "arm_compute/core/Error.h"
  #include "arm_compute/core/Helpers.h"
  #include "arm_compute/core/ILut.h"
  #include "arm_compute/core/ITensor.h"
  #include "arm_compute/core/TensorInfo.h"
  #include "arm_compute/core/Utils.h"
  #include "arm_compute/core/Validate.h"
  
  #include <cstddef>
  #include <cstdint>
  
  using namespace arm_compute;
  
  namespace arm_compute
  {
  class Coordinates;
  
  constexpr unsigned int num_num_elems_processed_per_iteration = 16;
  } // namespace arm_compute
  
  NETableLookupKernel::NETableLookupKernel()
      : _func(nullptr), _lut(nullptr)
  {
  }
  
  template <class T>
  void NETableLookupKernel::tableLookup(const Window &window)
  {
      uint32_t     offset = _lut->index_offset();
      size_t       count  = _lut->num_elements();
      const auto   lut    = reinterpret_cast<const T *>(_lut->buffer());
      unsigned int step   = num_num_elems_processed_per_iteration;
  
      ARM_COMPUTE_ERROR_ON(lut == nullptr);
  
      Iterator input  = Iterator(_input, window);
      Iterator output = Iterator(_output, window);
  
      execute_window_loop(window, [&](const Coordinates &)
      {
          auto input_ptr  = reinterpret_cast<const T *>(input.ptr());
          auto output_ptr = reinterpret_cast<T *>(output.ptr());
  
          for(unsigned int i = 0; i < step; ++i, ++input_ptr, ++output_ptr)
          {
              const int32_t index = offset + *input_ptr;
  
              if(0 <= index && index < static_cast<int32_t>(count))
              {
                  *output_ptr = lut[index];
              }
          }
      },
      input, output);
  }
  
  namespace arm_compute
  {
  template <>
  void NETableLookupKernel::tableLookup<uint8_t>(const Window &window)
  {
      const uint8_t *const lut  = _lut->buffer();
      unsigned int         step = num_num_elems_processed_per_iteration;
  
      ARM_COMPUTE_ERROR_ON(lut == nullptr);
  
      Iterator input  = Iterator(_input, window);
      Iterator output = Iterator(_output, window);
  
      execute_window_loop(window, [&](const Coordinates &)
      {
          const uint8_t *input_ptr  = input.ptr();
          uint8_t       *output_ptr = output.ptr();
  
          for(unsigned int i = 0; i < step; ++i)
          {
              *output_ptr++ = lut[*input_ptr++];
          }
      },
      input, output);
  }
  } // namespace arm_compute
  
  void NETableLookupKernel::configure(const ITensor *input, const ILut *lut, ITensor *output)
  {
      ARM_COMPUTE_ERROR_ON(input == nullptr);
      ARM_COMPUTE_ERROR_ON(lut == nullptr);
      ARM_COMPUTE_ERROR_ON(output == nullptr);
      ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8, DataType::S16);
      ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::U8, DataType::S16);
      ARM_COMPUTE_ERROR_ON_MISMATCHING_DATA_TYPES(input, output);
  
      _lut = lut;
  
      if(input->info()->data_type() == DataType::U8 && output->info()->data_type() == DataType::U8)
      {
          _func = &NETableLookupKernel::tableLookup<uint8_t>;
      }
      else if(input->info()->data_type() == DataType::S16 && output->info()->data_type() == DataType::S16)
      {
          _func = &NETableLookupKernel::tableLookup<int16_t>;
      }
      else
      {
          ARM_COMPUTE_ERROR("Unsupported combination of input and output DataType.");
      }
  
      INESimpleKernel::configure(input, output, num_num_elems_processed_per_iteration);
  }
  
  void NETableLookupKernel::run(const Window &window, const ThreadInfo &info)
  {
      ARM_COMPUTE_UNUSED(info);
      ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
      ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INESimpleKernel::window(), window);
      ARM_COMPUTE_ERROR_ON(_func == nullptr);
      (this->*_func)(window);
  }
  