Ifpack2_Relaxation_decl.hpp

// @HEADER
// *****************************************************************************
//       Ifpack2: Templated Object-Oriented Algebraic Preconditioner Package
//
// Copyright 2009 NTESS and the Ifpack2 contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#ifndef IFPACK2_RELAXATION_DECL_HPP
#define IFPACK2_RELAXATION_DECL_HPP

#include "Ifpack2_Preconditioner.hpp"
#include "Ifpack2_Details_CanChangeMatrix.hpp"
#include "Ifpack2_Parameters.hpp"
#include "Tpetra_Vector.hpp"
#include "Teuchos_ScalarTraits.hpp"
#include "Tpetra_CrsMatrix.hpp"  // Don't need the definition here
#include "Tpetra_BlockCrsMatrix.hpp"
#include <type_traits>
#include <KokkosKernels_Handle.hpp>
#include "Ifpack2_Details_GaussSeidel.hpp"
#include "Ifpack2_Details_InverseDiagonalKernel.hpp"

#ifndef DOXYGEN_SHOULD_SKIP_THIS
namespace Ifpack2 {
namespace Details {

template <class TpetraOperatorType>
class ScaledDampedResidual;  // forward declaration

}  // namespace Details
}  // namespace Ifpack2

namespace Teuchos {
// forward declarations
class ParameterList;
class Time;
}  // namespace Teuchos
#endif  // DOXYGEN_SHOULD_SKIP_THIS

namespace Ifpack2 {

template <class MatrixType>
class Relaxation : virtual public Ifpack2::Preconditioner<
                       typename MatrixType::scalar_type,
                       typename MatrixType::local_ordinal_type,
                       typename MatrixType::global_ordinal_type,
                       typename MatrixType::node_type>,
                   virtual public Ifpack2::Details::CanChangeMatrix<
                       Tpetra::RowMatrix<typename MatrixType::scalar_type,
                                         typename MatrixType::local_ordinal_type,
                                         typename MatrixType::global_ordinal_type,
                                         typename MatrixType::node_type> > {
 public:


  typedef typename MatrixType::scalar_type scalar_type;

  typedef typename MatrixType::local_ordinal_type local_ordinal_type;

  typedef typename MatrixType::global_ordinal_type global_ordinal_type;

  typedef typename MatrixType::node_type node_type;

  typedef typename MatrixType::node_type::device_type device_type;

  typedef typename Teuchos::ScalarTraits<scalar_type>::magnitudeType magnitude_type;

  typedef Tpetra::RowMatrix<scalar_type, local_ordinal_type,
                            global_ordinal_type, node_type>
      row_matrix_type;

  typedef Tpetra::Operator<scalar_type,
                           local_ordinal_type,
                           global_ordinal_type,
                           node_type>
      op_type;

  static_assert(std::is_same<MatrixType, row_matrix_type>::value, "Ifpack2::Relaxation: Please use MatrixType = Tpetra::RowMatrix.  This saves build times, library sizes, and executable sizes.  Don't worry, this class still works with CrsMatrix and BlockCrsMatrix; those are both subclasses of RowMatrix.");



  explicit Relaxation(const Teuchos::RCP<const row_matrix_type>& A);

  virtual ~Relaxation() = default;



  void setParameters(const Teuchos::ParameterList& params);

  bool supportsZeroStartingSolution() { return true; }

  void setZeroStartingSolution(bool zeroStartingSolution) { ZeroStartingSolution_ = zeroStartingSolution; };

  Teuchos::RCP<const Teuchos::ParameterList>
  getValidParameters() const;

  void initialize();

  inline bool isInitialized() const {
    return isInitialized_;
  }

  void compute();

  inline bool isComputed() const {
    return IsComputed_;
  }



  virtual void
  setMatrix(const Teuchos::RCP<const row_matrix_type>& A);



  void
  apply(const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
        Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y,
        Teuchos::ETransp mode = Teuchos::NO_TRANS,
        scalar_type alpha     = Teuchos::ScalarTraits<scalar_type>::one(),
        scalar_type beta      = Teuchos::ScalarTraits<scalar_type>::zero()) const;

  Teuchos::RCP<const Tpetra::Map<local_ordinal_type, global_ordinal_type, node_type> >
  getDomainMap() const;

  Teuchos::RCP<const Tpetra::Map<local_ordinal_type, global_ordinal_type, node_type> >
  getRangeMap() const;

  bool hasTransposeApply() const;

  void
  applyMat(const Tpetra::MultiVector<
               scalar_type,
               local_ordinal_type,
               global_ordinal_type,
               node_type>& X,
           Tpetra::MultiVector<
               scalar_type,
               local_ordinal_type,
               global_ordinal_type,
               node_type>& Y,
           Teuchos::ETransp mode = Teuchos::NO_TRANS) const;



  Teuchos::RCP<const Teuchos::Comm<int> > getComm() const;

  Teuchos::RCP<const row_matrix_type> getMatrix() const;

  double getComputeFlops() const;

  double getApplyFlops() const;

  int getNumInitialize() const;

  int getNumCompute() const;

  int getNumApply() const;

  double getInitializeTime() const;

  double getComputeTime() const;

  double getApplyTime() const;

  size_t getNodeSmootherComplexity() const;



  std::string description() const;

  void
  describe(Teuchos::FancyOStream& out,
           const Teuchos::EVerbosityLevel verbLevel =
               Teuchos::Describable::verbLevel_default) const;

 private:


  typedef Teuchos::ScalarTraits<scalar_type> STS;
  typedef Teuchos::ScalarTraits<magnitude_type> STM;

  typedef typename Kokkos::ArithTraits<scalar_type>::val_type impl_scalar_type;

  typedef Tpetra::CrsMatrix<scalar_type, local_ordinal_type,
                            global_ordinal_type, node_type>
      crs_matrix_type;
  typedef Tpetra::CrsGraph<local_ordinal_type,
                           global_ordinal_type, node_type>
      crs_graph_type;
  typedef Tpetra::MultiVector<scalar_type, local_ordinal_type,
                              global_ordinal_type, node_type>
      multivector_type;
  typedef Tpetra::BlockCrsMatrix<scalar_type, local_ordinal_type,
                                 global_ordinal_type, node_type>
      block_crs_matrix_type;
  typedef Tpetra::BlockMultiVector<scalar_type, local_ordinal_type,
                                   global_ordinal_type, node_type>
      block_multivector_type;

  typedef Tpetra::Map<local_ordinal_type, global_ordinal_type, node_type> map_type;
  typedef Tpetra::Import<local_ordinal_type, global_ordinal_type, node_type> import_type;

  typedef typename crs_matrix_type::nonconst_local_inds_host_view_type nonconst_local_inds_host_view_type;
  typedef typename crs_matrix_type::nonconst_values_host_view_type nonconst_values_host_view_type;

  Teuchos::RCP<Ifpack2::Details::InverseDiagonalKernel<op_type> > invDiagKernel_;



  typedef typename crs_matrix_type::local_matrix_device_type local_matrix_device_type;
  typedef typename local_matrix_device_type::StaticCrsGraphType::row_map_type lno_row_view_t;
  typedef typename local_matrix_device_type::StaticCrsGraphType::entries_type lno_nonzero_view_t;
  typedef typename local_matrix_device_type::values_type scalar_nonzero_view_t;
  typedef typename local_matrix_device_type::StaticCrsGraphType::device_type TemporaryWorkSpace;
  typedef typename local_matrix_device_type::StaticCrsGraphType::device_type PersistentWorkSpace;
  typedef typename local_matrix_device_type::StaticCrsGraphType::execution_space MyExecSpace;
  typedef typename KokkosKernels::Experimental::KokkosKernelsHandle<typename lno_row_view_t::const_value_type, local_ordinal_type, typename scalar_nonzero_view_t::value_type,
                                                                    MyExecSpace, TemporaryWorkSpace, PersistentWorkSpace>
      mt_kernel_handle_type;
  Teuchos::RCP<mt_kernel_handle_type> mtKernelHandle_;



  using SerialGaussSeidel = Ifpack2::Details::GaussSeidel<scalar_type, local_ordinal_type, global_ordinal_type, node_type>;
  Teuchos::RCP<SerialGaussSeidel> serialGaussSeidel_;



  Relaxation(const Relaxation<MatrixType>& RHS);

  Relaxation<MatrixType>& operator=(const Relaxation<MatrixType>& RHS);



  void setParametersImpl(Teuchos::ParameterList& params);

  void ApplyInverseRichardson(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y) const;

  void ApplyInverseJacobi(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y) const;

  void ApplyInverseJacobi_BlockCrsMatrix(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y) const;

  void ApplyInverseMTGS_CrsMatrix(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& B,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::ESweepDirection direction) const;

  void ApplyInverseSerialGS(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y,
      Tpetra::ESweepDirection direction) const;

  void ApplyInverseSerialGS_CrsMatrix(const crs_matrix_type& A,
                                      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& B,
                                      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
                                      Tpetra::ESweepDirection direction) const;

  void ApplyInverseSerialGS_RowMatrix(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y,
      Tpetra::ESweepDirection direction) const;

  void ApplyInverseSerialGS_BlockCrsMatrix(
      const block_crs_matrix_type& A,
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y,
      Tpetra::ESweepDirection direction);

  void ApplyInverseMTSGS_CrsMatrix(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& Y) const;

  void MTGaussSeidel(
      const Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& B,
      Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type>& X,
      const Tpetra::ESweepDirection direction) const;

  void computeBlockCrs();

  void updateCachedMultiVector(const Teuchos::RCP<const Tpetra::Map<local_ordinal_type, global_ordinal_type, node_type> >& map, size_t numVecs) const;



  mutable Teuchos::RCP<const Teuchos::ParameterList> validParams_;

  Teuchos::RCP<const row_matrix_type> A_;
  Teuchos::RCP<const import_type> Importer_;
  Teuchos::RCP<const import_type> pointImporter_;
  Teuchos::RCP<Tpetra::Vector<scalar_type, local_ordinal_type, global_ordinal_type, node_type> > Diagonal_;
  mutable Teuchos::RCP<Tpetra::MultiVector<scalar_type, local_ordinal_type, global_ordinal_type, node_type> > cachedMV_;

  typedef Kokkos::View<typename block_crs_matrix_type::impl_scalar_type***,
                       typename block_crs_matrix_type::device_type>
      block_diag_type;
  typedef Kokkos::View<typename block_crs_matrix_type::impl_scalar_type***,
                       typename block_crs_matrix_type::device_type,
                       Kokkos::MemoryUnmanaged>
      unmanaged_block_diag_type;

  block_diag_type blockDiag_;

  Teuchos::RCP<block_multivector_type> yBlockColumnPointMap_;

  int NumSweeps_ = 1;
  Details::RelaxationType PrecType_ = Ifpack2::Details::JACOBI;
  scalar_type DampingFactor_ = STS::one();
  bool IsParallel_;
  bool ZeroStartingSolution_ = true;
  bool DoBackwardGS_ = false;
  bool DoL1Method_ = false;
  magnitude_type L1Eta_ = Teuchos::as<magnitude_type>(1.5);
  scalar_type MinDiagonalValue_ = STS::zero();
  bool fixTinyDiagEntries_ = false;
  bool checkDiagEntries_ = false;
  int clusterSize_ = 1;
  int longRowThreshold_ = 0;
  KokkosGraph::ColoringAlgorithm mtColoringAlgorithm_ = KokkosGraph::COLORING_DEFAULT;

  int NumOuterSweeps_ = 1;
  int NumInnerSweeps_ = 1;
  bool InnerSpTrsv_ = false;
  scalar_type InnerDampingFactor_ = STS::one();
  bool CompactForm_ = false;

  bool is_matrix_structurally_symmetric_ = false;

  bool ifpack2_dump_matrix_ = false;

  bool isInitialized_ = false;
  bool IsComputed_ = false;
  int NumInitialize_ = 0;
  int NumCompute_ = 0;
  bool TimerForApply_ = true;
  mutable int NumApply_ = 0;
  double InitializeTime_ = 0.0;
  double ComputeTime_ = 0.0;
  mutable double ApplyTime_ = 0.0;
  double ComputeFlops_ = 0.0;
  mutable double ApplyFlops_ = 0.0;

  magnitude_type globalMinMagDiagEntryMag_ = STM::zero();
  magnitude_type globalMaxMagDiagEntryMag_ = STM::zero();
  size_t globalNumSmallDiagEntries_ = 0;
  size_t globalNumZeroDiagEntries_ = 0;
  size_t globalNumNegDiagEntries_ = 0;
  magnitude_type globalDiagNormDiff_ = STM::zero();

  Kokkos::View<size_t*, typename node_type::device_type> diagOffsets_;

  bool savedDiagOffsets_ = false;

  bool hasBlockCrsMatrix_ = false;

  Teuchos::ArrayRCP<local_ordinal_type> localSmoothingIndices_;

};  // class Relaxation

}  // namespace Ifpack2

#endif  // IFPACK2_RELAXATION_DECL_HPP