Function Eval

tensorflow/lite/kernels/mirror_pad.cc:97–145

template <typename T>
int Eval(EvalData<T>* eval_data, int current_dim, int flat_index,
         int output_index) {
  if (current_dim == eval_data->num_dims) {
    // Base case if we finished evaluating.
    if (output_index >= eval_data->output_size) {
      return output_index;
    }
    eval_data->output_data[output_index] = eval_data->input_data[flat_index];
    return output_index + 1;
  }
  // Check if the value is computed already.
  const int cache_index = current_dim * eval_data->input_size + flat_index;
  auto& cache_entry = eval_data->cache[cache_index];
  if (cache_entry.start != -1) {
    // Cache value is (start, end) interval. We can just copy the interval
    // directly.
    const int count = cache_entry.end - cache_entry.start;
    memcpy(eval_data->output_data + output_index,
           eval_data->output_data + cache_entry.start, count * sizeof(T));
    return output_index + count;
  }
  cache_entry.start = output_index;
  int64_t left_pad = 0, right_pad = 0;
  const int multiplier = (*eval_data->dimension_num_elements)[current_dim];
  const TfLiteTensor* padding_matrix = eval_data->padding_matrix;
  const auto offset = eval_data->offset;
  auto* dims = eval_data->input_dims;

  GetPadding(padding_matrix, current_dim, &left_pad, &right_pad);
  // Left padding
  for (int i = left_pad + offset - 1; i >= offset && left_pad > 0;
       --i, --left_pad) {
    output_index = Eval(eval_data, current_dim + 1, flat_index + i * multiplier,
                        output_index);
  }
  // Original values.
  for (int i = 0; i < dims->data[current_dim]; ++i) {
    output_index = Eval(eval_data, current_dim + 1, flat_index + i * multiplier,
                        output_index);
  }
  // Right padding.
  for (int i = dims->data[current_dim] - (1 + offset); i >= 0 && right_pad > 0;
       --i, --right_pad) {
    output_index = Eval(eval_data, current_dim + 1, flat_index + i * multiplier,
                        output_index);
  }
  cache_entry.end = output_index;
  return output_index;
}

// Returns the shape of the final output after padding.
std::unique_ptr<TfLiteIntArray, void (*)(TfLiteIntArray*)> GetPaddedOutputShape(