Eigen/src/Core/Swap.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_SWAP_H
#define EIGEN_SWAP_H

// IWYU pragma: private
#include "./InternalHeaderCheck.h"

namespace Eigen {

namespace internal {

// Overload default assignPacket behavior for swapping them
template <typename DstEvaluatorTypeT, typename SrcEvaluatorTypeT>
class generic_dense_assignment_kernel<DstEvaluatorTypeT, SrcEvaluatorTypeT,
                                      swap_assign_op<typename DstEvaluatorTypeT::Scalar>, Specialized>
    : public generic_dense_assignment_kernel<DstEvaluatorTypeT, SrcEvaluatorTypeT,
                                             swap_assign_op<typename DstEvaluatorTypeT::Scalar>, BuiltIn> {
 protected:
  typedef generic_dense_assignment_kernel<DstEvaluatorTypeT, SrcEvaluatorTypeT,
                                          swap_assign_op<typename DstEvaluatorTypeT::Scalar>, BuiltIn>
      Base;
  using Base::m_dst;
  using Base::m_functor;
  using Base::m_src;

 public:
  typedef typename Base::Scalar Scalar;
  typedef typename Base::DstXprType DstXprType;
  typedef swap_assign_op<Scalar> Functor;

  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE generic_dense_assignment_kernel(DstEvaluatorTypeT &dst,
                                                                        const SrcEvaluatorTypeT &src,
                                                                        const Functor &func, DstXprType &dstExpr)
      : Base(dst, src, func, dstExpr) {}

  template <int StoreMode, int LoadMode, typename PacketType>
  EIGEN_STRONG_INLINE void assignPacket(Index row, Index col) {
    PacketType tmp = m_src.template packet<LoadMode, PacketType>(row, col);
    const_cast<SrcEvaluatorTypeT &>(m_src).template writePacket<LoadMode>(
        row, col, m_dst.template packet<StoreMode, PacketType>(row, col));
    m_dst.template writePacket<StoreMode>(row, col, tmp);
  }

  template <int StoreMode, int LoadMode, typename PacketType>
  EIGEN_STRONG_INLINE void assignPacket(Index index) {
    PacketType tmp = m_src.template packet<LoadMode, PacketType>(index);
    const_cast<SrcEvaluatorTypeT &>(m_src).template writePacket<LoadMode>(
        index, m_dst.template packet<StoreMode, PacketType>(index));
    m_dst.template writePacket<StoreMode>(index, tmp);
  }

  // TODO find a simple way not to have to copy/paste this function from generic_dense_assignment_kernel, by simple I
  // mean no CRTP (Gael)
  template <int StoreMode, int LoadMode, typename PacketType>
  EIGEN_STRONG_INLINE void assignPacketByOuterInner(Index outer, Index inner) {
    Index row = Base::rowIndexByOuterInner(outer, inner);
    Index col = Base::colIndexByOuterInner(outer, inner);
    assignPacket<StoreMode, LoadMode, PacketType>(row, col);
  }
};

}  // namespace internal

}  // end namespace Eigen

#endif  // EIGEN_SWAP_H