text: /* Copyright 2019-2020 Canaan Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  #pragma once
  #include "../kernel_utils.h"
  #include <cmath>
  #include <runtime/runtime_op_utility.h>
  #include <xtl/xspan.hpp>
  
  namespace nncase
  {
  namespace kernels
  {
      namespace neutral
      {
          template <class TQ>
          void riscv_dequantize(const TQ *CXX_RESTRICT input, float *CXX_RESTRICT output, size_t count, const quant_param_t &param)
          {
              float scale = 1.f / param.scale;
              float zero = -param.zero_point * scale;
  
              for (size_t i = 0; i < count / 2; i++)
              {
                  // handwritten pipeline for in order CPU
                  auto in1_q = input[i * 2];
                  auto in2_q = input[i * 2 + 1];
                  auto in1 = (float)in1_q;
                  auto in2 = (float)in2_q;
                  auto out1 = in1 * scale + zero;
                  auto out2 = in2 * scale + zero;
  
                  output[i * 2] = out1;
                  output[i * 2 + 1] = out2;
              }
  
              if (count % 2)
                  output[count - 1] = input[count - 1] * scale + zero;
          }
  
          template <class TQ>
          void riscv_quantize(const float *CXX_RESTRICT input, TQ *CXX_RESTRICT output, size_t count, const quant_param_t &param)
          {
              float scale = param.scale;
              float zero = param.zero_point;
  
              for (size_t i = 0; i < count / 2; i++)
              {
                  auto in1 = input[i * 2];
                  auto in2 = input[i * 2 + 1];
                  in1 = in1 * scale + zero;
                  in2 = in2 * scale + zero;
                  int32_t out1, out2;
                  asm volatile("fcvt.w.s %0, %1, rne"
                               : "=r"(out1)
                               : "f"(in1));
                  asm volatile("fcvt.w.s %0, %1, rne"
                               : "=r"(out2)
                               : "f"(in2));
  
                  output[i * 2] = std::clamp(out1, (int32_t)std::numeric_limits<TQ>::lowest(), (int32_t)std::numeric_limits<TQ>::max());
                  output[i * 2 + 1] = std::clamp(out2, (int32_t)std::numeric_limits<TQ>::lowest(), (int32_t)std::numeric_limits<TQ>::max());
              }
  
              if (count % 2)
              {
                  auto in = (int32_t)roundf(input[count - 1] * scale + zero);
                  output[count - 1] = std::clamp(in, (int32_t)std::numeric_limits<TQ>::lowest(), (int32_t)std::numeric_limits<TQ>::max());
              }
          }
      }
  }
  }
  