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 "clip_arm.h"
  
  #ifdef __ARM_NEON
  #include <arm_neon.h>
  #endif // __ARM_NEON
  
  namespace ncnn {
  
  DEFINE_LAYER_CREATOR(Clip_arm)
  
  Clip_arm::Clip_arm()
  {
  #if __ARM_NEON
      support_packing = true;
  #endif // __ARM_NEON
  
      support_bf16_storage = true;
  }
  
  int Clip_arm::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
  {
      if (opt.use_bf16_storage)
          return forward_inplace_bf16s(bottom_top_blob, opt);
  
      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 __ARM_NEON
      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);
  
              float32x4_t _max = vdupq_n_f32(max);
              float32x4_t _min = vdupq_n_f32(min);
  
              for (int i=0; i<size; i++)
              {
                  float32x4_t _ptr = vld1q_f32(ptr);
                  _ptr = vmaxq_f32(_ptr, _min);
                  _ptr = vminq_f32(_ptr, _max);
                  vst1q_f32(ptr, _ptr);
  
                  ptr += 4;
              }
          }
  
          return 0;
      }
  #endif // __ARM_NEON
  
      #pragma omp parallel for num_threads(opt.num_threads)
      for (int q=0; q<channels; q++)
      {
          float* ptr = bottom_top_blob.channel(q);
  
  #if __ARM_NEON
          int nn = size >> 2;
          int remain = size & 3;
  #else
          int remain = size;
  #endif
  
  #if __ARM_NEON
          float32x4_t _max = vdupq_n_f32(max);
          float32x4_t _min = vdupq_n_f32(min);
  #if __aarch64__
          for (; nn>0; nn--)
          {
              float32x4_t _ptr = vld1q_f32(ptr);
              _ptr = vmaxq_f32(_ptr, _min);
              _ptr = vminq_f32(_ptr, _max);
              vst1q_f32(ptr, _ptr);
              ptr += 4;
          }
  #else
          if (nn > 0)
          {
          asm volatile(
              "0:                             \n"
              "pld        [%1, #128]          \n"
              "vld1.f32   {d0-d1}, [%1: 128]  \n"
  
              "vmax.f32   q0, q0, %q4         \n"
              "vmin.f32   q0, q0, %q5         \n"
  
              "subs       %0, #1              \n"
              "vst1.f32   {d0-d1}, [%1: 128]! \n"
  
              "bne        0b                  \n"
  
              : "=r"(nn),     // %0
                "=r"(ptr)     // %1
              : "0"(nn),
                "1"(ptr),
                "w"(_min),    // %q4
                "w"(_max)     // %q5
              : "cc", "memory", "q0"
          );
          }
  #endif // __aarch64__
  #endif // __ARM_NEON
  
          for (; remain>0; remain--)
          {
              if (*ptr < min)
                  *ptr = min;
  
              if (*ptr > max)
                  *ptr = max;
  
              ptr++;
          }
      }
  
      return 0;
  }
  
  int Clip_arm::forward_inplace_bf16s(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 __ARM_NEON
      if (elempack == 4)
      {
          #pragma omp parallel for num_threads(opt.num_threads)
          for (int q=0; q<channels; q++)
          {
              unsigned short* ptr = bottom_top_blob.channel(q);
  
              float32x4_t _max = vdupq_n_f32(max);
              float32x4_t _min = vdupq_n_f32(min);
  
              for (int i=0; i<size; i++)
              {
                  float32x4_t _ptr = vreinterpretq_f32_u32(vshll_n_u16(vld1_u16(ptr), 16));
                  _ptr = vmaxq_f32(_ptr, _min);
                  _ptr = vminq_f32(_ptr, _max);
                  vst1_u16(ptr, vshrn_n_u32(vreinterpretq_u32_f32(_ptr), 16));
  
                  ptr += 4;
              }
          }
  
          return 0;
      }
  #endif // __ARM_NEON
  
      #pragma omp parallel for num_threads(opt.num_threads)
      for (int q=0; q<channels; q++)
      {
          unsigned short* ptr = bottom_top_blob.channel(q);
  
  #if __ARM_NEON
          int nn = size >> 2;
          int remain = size & 3;
  #else
          int remain = size;
  #endif
  
  #if __ARM_NEON
          float32x4_t _max = vdupq_n_f32(max);
          float32x4_t _min = vdupq_n_f32(min);
          for (; nn>0; nn--)
          {
              float32x4_t _ptr = vreinterpretq_f32_u32(vshll_n_u16(vld1_u16(ptr), 16));
              _ptr = vmaxq_f32(_ptr, _min);
              _ptr = vminq_f32(_ptr, _max);
              vst1_u16(ptr, vshrn_n_u32(vreinterpretq_u32_f32(_ptr), 16));
              ptr += 4;
          }
  #endif // __ARM_NEON
  
          for (; remain>0; remain--)
          {
              float v = bfloat16_to_float32(*ptr);
              if (v < min)
                  v = min;
  
              if (v > max)
                  v = max;
  
              *ptr = float32_to_bfloat16(v);
              ptr++;
          }
      }
  
      return 0;
  }
  
  } // namespace ncnn
  