Eigen/src/Core/ForceAlignedAccess.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// 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_FORCEALIGNEDACCESS_H
#define EIGEN_FORCEALIGNEDACCESS_H

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

namespace Eigen {

/** \class ForceAlignedAccess
 * \ingroup Core_Module
 *
 * \brief Enforce aligned packet loads and stores regardless of what is requested
 *
 * \param ExpressionType the type of the object of which we are forcing aligned packet access
 *
 * This class is the return type of MatrixBase::forceAlignedAccess()
 * and most of the time this is the only way it is used.
 *
 * \sa MatrixBase::forceAlignedAccess()
 */

namespace internal {
template <typename ExpressionType>
struct traits<ForceAlignedAccess<ExpressionType>> : public traits<ExpressionType> {};
}  // namespace internal

template <typename ExpressionType>
class ForceAlignedAccess : public internal::dense_xpr_base<ForceAlignedAccess<ExpressionType>>::type {
 public:
  typedef typename internal::dense_xpr_base<ForceAlignedAccess>::type Base;
  EIGEN_DENSE_PUBLIC_INTERFACE(ForceAlignedAccess)

  EIGEN_DEVICE_FUNC explicit inline ForceAlignedAccess(const ExpressionType& matrix) : m_expression(matrix) {}

  EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index rows() const EIGEN_NOEXCEPT { return m_expression.rows(); }
  EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index cols() const EIGEN_NOEXCEPT { return m_expression.cols(); }
  EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index outerStride() const EIGEN_NOEXCEPT {
    return m_expression.outerStride();
  }
  EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index innerStride() const EIGEN_NOEXCEPT {
    return m_expression.innerStride();
  }

  EIGEN_DEVICE_FUNC inline const CoeffReturnType coeff(Index row, Index col) const {
    return m_expression.coeff(row, col);
  }

  EIGEN_DEVICE_FUNC inline Scalar& coeffRef(Index row, Index col) {
    return m_expression.const_cast_derived().coeffRef(row, col);
  }

  EIGEN_DEVICE_FUNC inline const CoeffReturnType coeff(Index index) const { return m_expression.coeff(index); }

  EIGEN_DEVICE_FUNC inline Scalar& coeffRef(Index index) { return m_expression.const_cast_derived().coeffRef(index); }

  template <int LoadMode>
  inline const PacketScalar packet(Index row, Index col) const {
    return m_expression.template packet<Aligned>(row, col);
  }

  template <int LoadMode>
  inline void writePacket(Index row, Index col, const PacketScalar& x) {
    m_expression.const_cast_derived().template writePacket<Aligned>(row, col, x);
  }

  template <int LoadMode>
  inline const PacketScalar packet(Index index) const {
    return m_expression.template packet<Aligned>(index);
  }

  template <int LoadMode>
  inline void writePacket(Index index, const PacketScalar& x) {
    m_expression.const_cast_derived().template writePacket<Aligned>(index, x);
  }

  EIGEN_DEVICE_FUNC operator const ExpressionType&() const { return m_expression; }

 protected:
  const ExpressionType& m_expression;

 private:
  ForceAlignedAccess& operator=(const ForceAlignedAccess&);
};

/** \returns an expression of *this with forced aligned access
 * \sa forceAlignedAccessIf(),class ForceAlignedAccess
 */
template <typename Derived>
inline const ForceAlignedAccess<Derived> MatrixBase<Derived>::forceAlignedAccess() const {
  return ForceAlignedAccess<Derived>(derived());
}

/** \returns an expression of *this with forced aligned access
 * \sa forceAlignedAccessIf(), class ForceAlignedAccess
 */
template <typename Derived>
inline ForceAlignedAccess<Derived> MatrixBase<Derived>::forceAlignedAccess() {
  return ForceAlignedAccess<Derived>(derived());
}

/** \returns an expression of *this with forced aligned access if \a Enable is true.
 * \sa forceAlignedAccess(), class ForceAlignedAccess
 */
template <typename Derived>
template <bool Enable>
inline add_const_on_value_type_t<std::conditional_t<Enable, ForceAlignedAccess<Derived>, Derived&>>
MatrixBase<Derived>::forceAlignedAccessIf() const {
  return derived();  // FIXME This should not work but apparently is never used
}

/** \returns an expression of *this with forced aligned access if \a Enable is true.
 * \sa forceAlignedAccess(), class ForceAlignedAccess
 */
template <typename Derived>
template <bool Enable>
inline std::conditional_t<Enable, ForceAlignedAccess<Derived>, Derived&> MatrixBase<Derived>::forceAlignedAccessIf() {
  return derived();  // FIXME This should not work but apparently is never used
}

}  // end namespace Eigen

#endif  // EIGEN_FORCEALIGNEDACCESS_H