text: // Tencent is pleased to support the open source community by making ncnn available.
  //
  // Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
  //
  // Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
  // in compliance with the License. You may obtain a copy of the License at
  //
  // https://opensource.org/licenses/BSD-3-Clause
  //
  // 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.
  
  #include "sigmoid_x86.h"
  
  #include "sse_activation.h"
  #if __AVX__
  #include "avx_activation.h"
  #endif // __AVX__
  
  #include <math.h>
  
  namespace ncnn {
  
  Sigmoid_x86::Sigmoid_x86()
  {
      support_packing = true;
  }
  
  int Sigmoid_x86::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
  {
      int w = bottom_top_blob.w;
      int h = bottom_top_blob.h;
      int channels = bottom_top_blob.c;
      int size = w * h;
      int elempack = bottom_top_blob.elempack;
  
  #if __AVX__
      if (elempack == 8)
      {
          #pragma omp parallel for num_threads(opt.num_threads)
          for (int q = 0; q < channels; q++)
          {
              float* ptr = bottom_top_blob.channel(q);
              for (int i = 0; i < size; i++)
              {
                  __m256 _p = _mm256_loadu_ps(ptr);
                  _mm256_storeu_ps(ptr, sigmoid_avx(_p));
                  ptr += 8;
              }
          }
  
          return 0;
      }
  #endif // __AVX__
  
      if (elempack == 4)
      {
          #pragma omp parallel for num_threads(opt.num_threads)
          for (int q = 0; q < channels; q++)
          {
              float* ptr = bottom_top_blob.channel(q);
              for (int i = 0; i < size; i++)
              {
                  __m128 _p = _mm_loadu_ps(ptr);
                  _mm_storeu_ps(ptr, sigmoid_sse(_p));
                  ptr += 4;
              }
          }
  
          return 0;
      }
  
      #pragma omp parallel for num_threads(opt.num_threads)
      for (int q = 0; q < channels; q++)
      {
          float* ptr = bottom_top_blob.channel(q);
  
          int i = 0;
  #if __AVX__
          for (; i + 7 < size; i += 8)
          {
              __m256 _p = _mm256_loadu_ps(ptr);
              _mm256_storeu_ps(ptr, sigmoid_avx(_p));
              ptr += 8;
          }
  #endif // __AVX__
          for (; i + 3 < size; i += 4)
          {
              __m128 _p = _mm_loadu_ps(ptr);
              _mm_storeu_ps(ptr, sigmoid_sse(_p));
              ptr += 4;
          }
          for (; i < size; i++)
          {
              *ptr = 1.f / (1.f + exp(-*ptr));
  
              ptr++;
          }
      }
  
      return 0;
  }
  
  } // namespace ncnn
  