text: /*
   * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
   *
   * 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.
   */
  
  #ifndef __SWIZZLE_H__
  #define __SWIZZLE_H__
  
  class ARMComputeAxis
  {
  public:
    ARMComputeAxis() = default;
  
  public:
    explicit ARMComputeAxis(uint32_t value) : _value{value}
    {
      // DO NOTHING
    }
  
  public:
    uint32_t value(void) const { return _value; }
  
  private:
    uint32_t _value;
  };
  
  // Convert T/F Lite / NNAPI axis (based on ...NHWC) to ARMCompute axis (WHCN...)
  inline ARMComputeAxis ToARMComputeAxis(uint32_t rank, uint32_t axis)
  {
    assert(rank > axis);
    const ARMComputeAxis reversed{(rank - axis) - 1};
  
    if (rank < 4)
    {
      return reversed;
    }
  
    // DEPTH
    if (0 == reversed.value())
    {
      return ARMComputeAxis{2};
    }
    // WIDTH
    if (1 == reversed.value())
    {
      return ARMComputeAxis{0};
    }
    // HEIGHT
    if (2 == reversed.value())
    {
      return ARMComputeAxis{1};
    }
  
    // ELSE
    return reversed;
  }
  
  #include <cassert>
  
  template <typename T> inline T ReorderBits(T in, size_t numOfBits)
  {
    assert(numOfBits > 0);
    T out = 0;
    for (int32_t i = numOfBits - 1; i >= 0; --i)
    {
      const uint32_t toShift = numOfBits - ToARMComputeAxis(numOfBits, i).value() - 1;
      out += ((in & 1) << toShift);
      in >>= 1;
    }
    return out;
  }
  
  #endif // __SWIZZLE_H__
  