Tpetra_MultiVector_decl.hpp

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#ifndef TPETRA_MULTIVECTOR_DECL_HPP
#define TPETRA_MULTIVECTOR_DECL_HPP


#include "Tpetra_ConfigDefs.hpp"
#include "Tpetra_DistObject.hpp"
#include "Tpetra_Map_decl.hpp"

#include "Kokkos_DualView.hpp"
#include "Kokkos_MultiVector.hpp"

#include "Teuchos_BLAS_types.hpp"
#include "Teuchos_DataAccess.hpp"
#include "Teuchos_Range1D.hpp"

#include "KokkosCompat_ClassicNodeAPI_Wrapper.hpp"
#include "Kokkos_InnerProductSpaceTraits.hpp"
#include "Kokkos_ArithTraits.hpp"

#include "Tpetra_KokkosRefactor_DistObject.hpp"
#include "Tpetra_KokkosRefactor_Details_MultiVectorLocalDeepCopy.hpp"
#include <type_traits>

namespace Tpetra {

#ifndef DOXYGEN_SHOULD_SKIP_THIS
  // forward declaration of Map
  template<class LO, class GO, class N> class Map;

  // forward declaration of Vector, needed to prevent circular inclusions
  template<class S, class LO, class GO, class N, const bool classic> class Vector;

  // forward declaration of MultiVector (declared later in this file)
  template<class S, class LO, class GO, class N, const bool classic> class MultiVector;
#endif // DOXYGEN_SHOULD_SKIP_THIS

  namespace Details {
    template<class DstMultiVectorType, class SrcMultiVectorType>
    struct MultiVectorCloner {
      typedef DstMultiVectorType dst_mv_type;
      typedef SrcMultiVectorType src_mv_type;

      static Teuchos::RCP<dst_mv_type>
      clone (const src_mv_type& X,
             const Teuchos::RCP<typename dst_mv_type::node_type>& node2);
    };

  } // namespace Details

  template <class DS, class DL, class DG, class DN, const bool dstClassic,
            class SS, class SL, class SG, class SN, const bool srcClassic>
  void
  deep_copy (MultiVector<DS, DL, DG, DN, dstClassic>& dst,
             const MultiVector<SS, SL, SG, SN, srcClassic>& src);

  template <class ST, class LO, class GO, class NT, const bool classic = NT::classic>
  MultiVector<ST, LO, GO, NT, classic>
  createCopy (const MultiVector<ST, LO, GO, NT, classic>& src);

  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node, const bool classic = Node::classic>
  Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
  createMultiVector (const Teuchos::RCP<const Map<LocalOrdinal, GlobalOrdinal, Node> >& map,
                     const size_t numVectors);

  template <class Scalar = Details::DefaultTypes::scalar_type,
            class LocalOrdinal = Details::DefaultTypes::local_ordinal_type,
            class GlobalOrdinal = Details::DefaultTypes::global_ordinal_type,
            class Node = Details::DefaultTypes::node_type,
            const bool classic = Node::classic>
  class MultiVector :
    public DistObject<Scalar, LocalOrdinal, GlobalOrdinal, Node>
  {
    static_assert (! classic, "The 'classic' version of Tpetra was deprecated long ago, and has been removed.");

  public:


    typedef Scalar scalar_type;
    typedef typename Kokkos::Details::ArithTraits<Scalar>::val_type impl_scalar_type;
    typedef LocalOrdinal local_ordinal_type;
    typedef GlobalOrdinal global_ordinal_type;
    typedef Node node_type;

    typedef typename Node::device_type device_type;

  private:
    typedef DistObject<Scalar, LocalOrdinal, GlobalOrdinal, Node> base_type;

  public:
    typedef typename Kokkos::Details::InnerProductSpaceTraits<impl_scalar_type>::dot_type dot_type;

    typedef typename Kokkos::Details::ArithTraits<impl_scalar_type>::mag_type mag_type;

    typedef typename Node::execution_space execution_space;

    typedef Kokkos::DualView<impl_scalar_type**, Kokkos::LayoutLeft,
      typename execution_space::execution_space> dual_view_type;

    typedef Map<LocalOrdinal, GlobalOrdinal, Node> map_type;



    MultiVector ();

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const size_t numVecs,
                 const bool zeroOut = true);

    MultiVector (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& source);

    MultiVector (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& source,
                 const Teuchos::DataAccess copyOrView);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const Teuchos::ArrayView<const Scalar>& A,
                 const size_t LDA,
                 const size_t NumVectors);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const Teuchos::ArrayView<const Teuchos::ArrayView<const Scalar> >&ArrayOfPtrs,
                 const size_t NumVectors);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const dual_view_type& view);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const typename dual_view_type::t_dev& d_view);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const dual_view_type& view,
                 const dual_view_type& origView);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const dual_view_type& view,
                 const Teuchos::ArrayView<const size_t>& whichVectors);

    MultiVector (const Teuchos::RCP<const map_type>& map,
                 const dual_view_type& view,
                 const dual_view_type& origView,
                 const Teuchos::ArrayView<const size_t>& whichVectors);

    template <class Node2>
    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node2> >
    clone (const Teuchos::RCP<Node2>& node2) const;

    virtual ~MultiVector ();



    void
    replaceGlobalValue (GlobalOrdinal globalRow,
                        size_t col,
                        const impl_scalar_type& value);

    template<typename T>
    typename std::enable_if<! std::is_same<T, impl_scalar_type>::value && std::is_convertible<T, impl_scalar_type>::value, void>::type
    replaceGlobalValue (GlobalOrdinal globalRow,
                        size_t col,
                        const T& value)
    {
      replaceGlobalValue (globalRow, col, static_cast<impl_scalar_type> (value));
    }

    void
    sumIntoGlobalValue (GlobalOrdinal globalRow,
                        size_t col,
                        const impl_scalar_type& value);

    template<typename T>
    typename std::enable_if<! std::is_same<T, impl_scalar_type>::value && std::is_convertible<T, impl_scalar_type>::value, void>::type
    sumIntoGlobalValue (GlobalOrdinal globalRow,
                        size_t col,
                        const T& value)
    {
      sumIntoGlobalValue (globalRow, col, static_cast<impl_scalar_type> (value));
    }

    void
    replaceLocalValue (LocalOrdinal localRow,
                       size_t col,
                       const impl_scalar_type& value);

    template<typename T>
    typename std::enable_if<! std::is_same<T, impl_scalar_type>::value && std::is_convertible<T, impl_scalar_type>::value, void>::type
    replaceLocalValue (LocalOrdinal localRow,
                       size_t col,
                       const T& value)
    {
      replaceLocalValue (localRow, col, static_cast<impl_scalar_type> (value));
    }

    void
    sumIntoLocalValue (LocalOrdinal localRow,
                       size_t col,
                       const impl_scalar_type& value);

    template<typename T>
    typename std::enable_if<! std::is_same<T, impl_scalar_type>::value && std::is_convertible<T, impl_scalar_type>::value, void>::type
    sumIntoLocalValue (LocalOrdinal localRow,
                       size_t col,
                       const T& value)
    {
      sumIntoLocalValue (localRow, col, static_cast<impl_scalar_type> (value));
    }

    void putScalar (const Scalar& value);

    void randomize();

    void replaceMap (const Teuchos::RCP<const map_type>& map);

    void reduce();

    MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>&
    operator= (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& source);




    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subCopy (const Teuchos::Range1D& colRng) const;

    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subCopy (const Teuchos::ArrayView<const size_t>& cols) const;

    Teuchos::RCP<const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subView (const Teuchos::Range1D& colRng) const;

    Teuchos::RCP<const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subView (const Teuchos::ArrayView<const size_t>& cols) const;

    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subViewNonConst (const Teuchos::Range1D& colRng);

    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    subViewNonConst (const Teuchos::ArrayView<const size_t>& cols);

    Teuchos::RCP<const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    offsetView (const Teuchos::RCP<const map_type>& subMap,
                const size_t offset) const;

    Teuchos::RCP<MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    offsetViewNonConst (const Teuchos::RCP<const map_type>& subMap,
                        const size_t offset);

    Teuchos::RCP<const Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    getVector (const size_t j) const;

    Teuchos::RCP<Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic> >
    getVectorNonConst (const size_t j);

    Teuchos::ArrayRCP<const Scalar> getData (size_t j) const;

    Teuchos::ArrayRCP<Scalar> getDataNonConst (size_t j);

    void
    get1dCopy (const Teuchos::ArrayView<Scalar>& A,
               const size_t LDA) const;

    void
    get2dCopy (const Teuchos::ArrayView<const Teuchos::ArrayView<Scalar> >& ArrayOfPtrs) const;

    Teuchos::ArrayRCP<const Scalar> get1dView () const;

    Teuchos::ArrayRCP<Teuchos::ArrayRCP<const Scalar> > get2dView () const;

    Teuchos::ArrayRCP<Scalar> get1dViewNonConst ();

    Teuchos::ArrayRCP<Teuchos::ArrayRCP<Scalar> > get2dViewNonConst ();

    KokkosClassic::MultiVector<Scalar, Node> getLocalMV () const;

    dual_view_type getDualView () const;

    template<class TargetDeviceType>
    void sync () {
      getDualView ().template sync<TargetDeviceType> ();
    }

    template<class TargetDeviceType>
    void modify () {
      getDualView ().template modify<TargetDeviceType> ();
    }

    template<class TargetDeviceType>
    typename Kokkos::Impl::if_c<
      std::is_same<
        typename device_type::memory_space,
        typename TargetDeviceType::memory_space>::value,
      typename dual_view_type::t_dev,
      typename dual_view_type::t_host>::type
    getLocalView () const {
      return getDualView ().template view<TargetDeviceType> ();
    }



    void
    dot (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
         const Teuchos::ArrayView<dot_type>& dots) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<dot_type, T>::value), void >::type
    dot (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
         const Teuchos::ArrayView<T> &dots) const
    {
      const size_t sz = static_cast<size_t> (dots.size ());
      Teuchos::Array<dot_type> dts (sz);
      this->dot (A, dts);
      for (size_t i = 0; i < sz; ++i) {
        // If T and dot_type differ, this does an implicit conversion.
        dots[i] = dts[i];
      }
    }

    template <typename T>
    typename std::enable_if< ! (std::is_same<dot_type, T>::value), void >::type
    dot (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
         std::vector<T>& dots) const
    {
      const size_t sz = dots.size ();
      Teuchos::Array<dot_type> dts (sz);
      this->dot (A, dts);
      for (size_t i = 0; i < sz; ++i) {
        // If T and dot_type differ, this does an implicit conversion.
        dots[i] = dts[i];
      }
    }

    void
    dot (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
         const Kokkos::View<dot_type*, device_type>& dots) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<dot_type, T>::value), void >::type
    dot (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
         const Kokkos::View<T*, device_type>& dots) const
    {
      const size_t numDots = dots.dimension_0 ();
      Kokkos::View<dot_type*, device_type> dts ("MV::dot tmp", numDots);
      // Call overload that takes a Kokkos::View<dot_type*, device_type>.
      this->dot (A, dts);
      // FIXME (mfh 14 Jul 2014) Does this actually work if dot_type
      // and T differ?  We would need a test for this, but only the
      // Sacado and Stokhos packages are likely to care about this use
      // case.  It could also come up for Kokkos::complex ->
      // std::complex conversions, but those two implementations
      // should generally be bitwise compatible.
      Kokkos::deep_copy (dots, dts);
    }

    void abs (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A);

    void reciprocal (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A);

    void scale (const Scalar& alpha);

    void scale (const Teuchos::ArrayView<const Scalar>& alpha);

    void scale (const Kokkos::View<const impl_scalar_type*, device_type>& alpha);

    void
    scale (const Scalar& alpha,
           const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A);

    void
    update (const Scalar& alpha,
            const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
            const Scalar& beta);

    void
    update (const Scalar& alpha,
            const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
            const Scalar& beta,
            const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& B,
            const Scalar& gamma);

    void norm1 (const Kokkos::View<mag_type*, device_type>& norms) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<mag_type, T>::value), void >::type
    norm1 (const Kokkos::View<T*, device_type>& norms) const
    {
      const size_t numNorms = norms.dimension_0 ();
      Kokkos::View<mag_type*, device_type> tmpNorms ("MV::norm1 tmp", numNorms);
      // Call overload that takes a Kokkos::View<mag_type*, device_type>.
      this->norm1 (tmpNorms);
      // FIXME (mfh 15 Jul 2014) Does this actually work if mag_type
      // and T differ?  We would need a test for this, but only the
      // Sacado and Stokhos packages are likely to care about this use
      // case.  It could also come up with Kokkos::complex ->
      // std::complex conversion.
      Kokkos::deep_copy (norms, tmpNorms);
    }


    void norm1 (const Teuchos::ArrayView<mag_type>& norms) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<mag_type,T>::value), void >::type
    norm1 (const Teuchos::ArrayView<T>& norms) const
    {
      typedef typename Teuchos::ArrayView<T>::size_type size_type;
      const size_type sz = norms.size ();
      Teuchos::Array<mag_type> theNorms (sz);
      this->norm1 (theNorms);
      for (size_type i = 0; i < sz; ++i) {
        // If T and mag_type differ, this does an implicit conversion.
        norms[i] = theNorms[i];
      }
    }

    void norm2 (const Kokkos::View<mag_type*, device_type>& norms) const;

    template<typename T>
    typename std::enable_if< ! (std::is_same<mag_type, T>::value), void >::type
    norm2 (const Kokkos::View<T*, device_type>& norms) const
    {
      const size_t numNorms = norms.dimension_0 ();
      Kokkos::View<mag_type*, device_type> theNorms ("MV::norm2 tmp", numNorms);
      // Call overload that takes a Kokkos::View<mag_type*, device_type>.
      this->norm2 (theNorms);
      // FIXME (mfh 14 Jul 2014) Does this actually work if mag_type
      // and T differ?  We would need a test for this, but only the
      // Sacado and Stokhos packages are likely to care about this use
      // case.  This could also come up with Kokkos::complex ->
      // std::complex conversion.
      Kokkos::deep_copy (norms, theNorms);
    }

    void norm2 (const Teuchos::ArrayView<mag_type>& norms) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<mag_type,T>::value), void >::type
    norm2 (const Teuchos::ArrayView<T>& norms) const
    {
      typedef typename Teuchos::ArrayView<T>::size_type size_type;
      const size_type sz = norms.size ();
      Teuchos::Array<mag_type> theNorms (sz);
      this->norm2 (theNorms);
      for (size_type i = 0; i < sz; ++i) {
        // If T and mag_type differ, this does an implicit conversion.
        norms[i] = theNorms[i];
      }
    }

    void normInf (const Kokkos::View<mag_type*, device_type>& norms) const;

    template<typename T>
    typename std::enable_if< ! (std::is_same<mag_type, T>::value), void >::type
    normInf (const Kokkos::View<T*, device_type>& norms) const
    {
      const size_t numNorms = norms.dimension_0 ();
      Kokkos::View<mag_type*, device_type> theNorms ("MV::normInf tmp", numNorms);
      // Call overload that takes a Kokkos::View<mag_type*, device_type>.
      this->normInf (theNorms);
      // FIXME (mfh 15 Jul 2014) Does this actually work if mag_type
      // and T differ?  We would need a test for this, but only the
      // Sacado and Stokhos packages are likely to care about this use
      // case.  This could also come up with Kokkos::complex ->
      // std::complex conversion.
      Kokkos::deep_copy (norms, theNorms);
    }

    void normInf (const Teuchos::ArrayView<mag_type>& norms) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<mag_type,T>::value), void >::type
    normInf (const Teuchos::ArrayView<T>& norms) const
    {
      typedef typename Teuchos::ArrayView<T>::size_type size_type;
      const size_type sz = norms.size ();
      Teuchos::Array<mag_type> theNorms (sz);
      this->norm2 (theNorms);
      for (size_type i = 0; i < sz; ++i) {
        // If T and mag_type differ, this does an implicit conversion.
        norms[i] = theNorms[i];
      }
    }

    void
    normWeighted (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& weights,
                  const Teuchos::ArrayView<mag_type>& norms) const;

    template <typename T>
    typename std::enable_if< ! (std::is_same<mag_type,T>::value), void >::type
    normWeighted (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& weights,
                  const Teuchos::ArrayView<T>& norms) const
    {
      typedef typename Teuchos::ArrayView<T>::size_type size_type;
      const size_type sz = norms.size ();
      Teuchos::Array<mag_type> theNorms (sz);
      this->normWeighted (weights, theNorms);
      for (size_type i = 0; i < sz; ++i) {
        // If T and mag_type differ, this does an implicit conversion.
        norms[i] = theNorms[i];
      }
    }

    void meanValue (const Teuchos::ArrayView<impl_scalar_type>& means) const;

    template <typename T>
    typename std::enable_if<! std::is_same<impl_scalar_type, T>::value, void>::type
    meanValue (const Teuchos::ArrayView<T>& means) const
    {
      typedef typename Teuchos::Array<T>::size_type size_type;
      const size_type numMeans = means.size ();

      Teuchos::Array<impl_scalar_type> theMeans (numMeans);
      this->meanValue (theMeans ());
      for (size_type k = 0; k < numMeans; ++k) {
        means[k] = static_cast<T> (theMeans[k]);
      }
    }

    void
    multiply (Teuchos::ETransp transA,
              Teuchos::ETransp transB,
              const Scalar& alpha,
              const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
              const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& B,
              const Scalar& beta);

    void
    elementWiseMultiply (Scalar scalarAB,
                         const Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& A,
                         const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& B,
                         Scalar scalarThis);


    size_t getNumVectors() const;

    size_t getLocalLength() const;

    global_size_t getGlobalLength() const;

    size_t getStride() const;

    bool isConstantStride() const;




    virtual std::string description() const;

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

    virtual void
    removeEmptyProcessesInPlace (const Teuchos::RCP<const map_type>& newMap);

    void setCopyOrView (const Teuchos::DataAccess copyOrView) {
      TEUCHOS_TEST_FOR_EXCEPTION(
        copyOrView == Teuchos::Copy, std::invalid_argument,
        "Tpetra::MultiVector::setCopyOrView: The Kokkos refactor version of "
        "MultiVector _only_ implements view semantics.  You may not call this "
        "method with copyOrView = Teuchos::Copy.  The only valid argument is "
        "Teuchos::View.");
    }

    Teuchos::DataAccess getCopyOrView () const {
      return Teuchos::View;
    }

    void
    assign (const MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& src);

  protected:
    template <class DS, class DL, class DG, class DN, const bool dstClassic,
              class SS, class SL, class SG, class SN, const bool srcClassic>
    friend void
    deep_copy (MultiVector<DS, DL, DG, DN, dstClassic>& dst,
               const MultiVector<SS, SL, SG, SN, srcClassic>& src);

    mutable dual_view_type view_;

    mutable dual_view_type origView_;

    Teuchos::Array<size_t> whichVectors_;



    enum EWhichNorm {
      NORM_ONE, //<! Use the one-norm
      NORM_TWO, //<! Use the two-norm
      NORM_INF  //<! Use the infinity-norm
    };

    void
    normImpl (const Kokkos::View<mag_type*, device_type>& norms,
              const EWhichNorm whichNorm) const;



    // Return true if and only if VectorIndex is a valid column index.
    bool vectorIndexOutOfRange (const size_t VectorIndex) const;

    template <class T>
    Teuchos::ArrayRCP<T>
    getSubArrayRCP (Teuchos::ArrayRCP<T> arr, size_t j) const;

    size_t getOrigNumLocalRows () const;

    size_t getOrigNumLocalCols () const;



    virtual bool
    checkSizes (const SrcDistObject& sourceObj);

    virtual size_t constantNumberOfPackets () const;

    virtual bool useNewInterface () { return true; }

    virtual void
    copyAndPermuteNew (
      const SrcDistObject& sourceObj,
      size_t numSameIDs,
      const Kokkos::View<const local_ordinal_type*, execution_space>& permuteToLIDs,
      const Kokkos::View<const local_ordinal_type*, execution_space>& permuteFromLIDs);

    virtual void
    packAndPrepareNew (
      const SrcDistObject& sourceObj,
      const Kokkos::View<const local_ordinal_type*, execution_space>& exportLIDs,
      Kokkos::View<impl_scalar_type*, execution_space>& exports,
      const Kokkos::View<size_t*, execution_space>& numPacketsPerLID,
      size_t& constantNumPackets,
      Distributor &distor);

    virtual void
    unpackAndCombineNew (
      const Kokkos::View<const LocalOrdinal*, execution_space>& importLIDs,
      const Kokkos::View<const impl_scalar_type*, execution_space>& imports,
      const Kokkos::View<size_t*, execution_space>& numPacketsPerLID,
      size_t constantNumPackets,
      Distributor &distor,
      CombineMode CM);

    void createViews () const;
    void createViewsNonConst (KokkosClassic::ReadWriteOption rwo);
    void releaseViews () const;

    typename dual_view_type::t_dev getKokkosView() const { return view_.d_view; }

  }; // class MultiVector

  namespace Details {

    template<class DstMultiVectorType,
             class SrcMultiVectorType>
    Teuchos::RCP<typename MultiVectorCloner<DstMultiVectorType, SrcMultiVectorType>::dst_mv_type>
    MultiVectorCloner<DstMultiVectorType, SrcMultiVectorType>::
    clone (const src_mv_type& X,
           const Teuchos::RCP<typename dst_mv_type::node_type>& node2)
    {
      typedef typename src_mv_type::map_type src_map_type;
      typedef typename dst_mv_type::map_type dst_map_type;
      typedef typename dst_mv_type::node_type dst_node_type;
      typedef typename dst_mv_type::dual_view_type dst_dual_view_type;

      // Clone X's Map to have the new Node type.
      RCP<const src_map_type> map1 = X.getMap ();
      RCP<const dst_map_type> map2 = map1.is_null () ?
        Teuchos::null : map1->template clone<dst_node_type> (node2);

      const size_t lclNumRows = X.getLocalLength ();
      const size_t numCols = X.getNumVectors ();
      dst_dual_view_type Y_view ("MV::dual_view", lclNumRows, numCols);

      RCP<dst_mv_type> Y (new dst_mv_type (map2, Y_view));
      // Let deep_copy do the work for us, to avoid code duplication.
      ::Tpetra::deep_copy (Y, X);
      return Y ;
    }

  } // namespace Details

  template <class ST, class LO, class GO, class NT, const bool classic>
  void
  deep_copy (MultiVector<ST, LO, GO, NT, classic>& dst,
             const MultiVector<ST, LO, GO, NT, classic>& src)
  {
    // NOTE (mfh 11 Sep 2014) We can't implement deep_copy with
    // shallow-copy operator=, because that would invalidate existing
    // views of dst!
    dst.assign (src);
  }

  // Implementation of the most generic version of MultiVector deep_copy.
  template <class DS, class DL, class DG, class DN, const bool dstClassic,
            class SS, class SL, class SG, class SN, const bool srcClassic>
  void
  deep_copy (MultiVector<DS, DL, DG, DN, dstClassic>& dst,
             const MultiVector<SS, SL, SG, SN, srcClassic>& src)
  {
    typedef typename DN::device_type DD;
    //typedef typename SN::device_type SD;

    TEUCHOS_TEST_FOR_EXCEPTION(
      dst.getGlobalLength () != src.getGlobalLength () ||
      dst.getNumVectors () != src.getNumVectors (), std::invalid_argument,
      "Tpetra::deep_copy: Global dimensions of the two Tpetra::MultiVector "
      "objects do not match.  src has dimensions [" << src.getGlobalLength ()
      << "," << src.getNumVectors () << "], and dst has dimensions ["
      << dst.getGlobalLength () << "," << dst.getNumVectors () << "].");

    // FIXME (mfh 28 Jul 2014) Don't throw; just set a local error flag.
    TEUCHOS_TEST_FOR_EXCEPTION(
      dst.getLocalLength () != src.getLocalLength (), std::invalid_argument,
      "Tpetra::deep_copy: The local row counts of the two Tpetra::MultiVector "
      "objects do not match.  src has " << src.getLocalLength () << " row(s) "
      << " and dst has " << dst.getLocalLength () << " row(s).");

    if (src.isConstantStride () && dst.isConstantStride ()) {
      typedef typename MultiVector<DS, DL, DG, DN, dstClassic>::dual_view_type::t_host::execution_space HES;
      typedef typename MultiVector<DS, DL, DG, DN, dstClassic>::dual_view_type::t_dev::execution_space DES;

      if (src.getDualView ().modified_device >= src.getDualView ().modified_host) {
        // Device memory has the most recent version of src.
        dst.template modify<DES> (); // We are about to modify dst on device.
        // Copy from src to dst on device.
        Details::localDeepCopyConstStride (dst.getDualView ().d_view,
                                           src.getDualView ().d_view);
        dst.template sync<HES> (); // Sync dst from device to host.
      }
      else { // Host memory has the most recent version of src.
        dst.template modify<HES> (); // We are about to modify dst on host.
        // Copy from src to dst on host.
        Details::localDeepCopyConstStride (dst.getDualView ().h_view,
                                           src.getDualView ().h_view);
        dst.template sync<DES> (); // Sync dst from host to device.
      }
    }
    else {
      typedef Kokkos::DualView<SL*, DD> whichvecs_type;
      typedef typename whichvecs_type::t_dev::execution_space DES;
      typedef typename whichvecs_type::t_host::execution_space HES;

      if (dst.isConstantStride ()) {
        const SL numWhichVecs = static_cast<SL> (src.whichVectors_.size ());
        const std::string whichVecsLabel ("MV::deep_copy::whichVecs");

        // We can't sync src, since it is only an input argument.
        // Thus, we have to use the most recently modified version of
        // src, which coudl be either the device or host version.
        if (src.getDualView ().modified_device >= src.getDualView ().modified_host) {
          // Copy from the device version of src.
          //
          // whichVecs tells the kernel which vectors (columns) of src
          // to copy.  Fill whichVecs on the host, and sync to device.
          whichvecs_type whichVecs (whichVecsLabel, numWhichVecs);
          whichVecs.template modify<HES> ();
          for (SL i = 0; i < numWhichVecs; ++i) {
            whichVecs.h_view(i) = static_cast<SL> (src.whichVectors_[i]);
          }
          // Sync the host version of whichVecs to the device.
          whichVecs.template sync<DES> ();

          // Mark the device version of dst's DualView as modified.
          dst.template modify<DES> ();
          // Copy from the selected vectors of src to dst, on the device.
          Details::localDeepCopy (dst.getDualView ().d_view,
                                  src.getDualView ().d_view,
                                  dst.isConstantStride (),
                                  src.isConstantStride (),
                                  whichVecs.d_view,
                                  whichVecs.d_view);
          // Sync dst's DualView to the host.  This is cheaper than
          // repeating the above copy from src to dst on the host.
          dst.template sync<HES> ();
        }
        else { // host version of src was the most recently modified
          // Copy from the host version of src.
          //
          // whichVecs tells the kernel which vectors (columns) of src
          // to copy.  Fill whichVecs on the host, and use it there.
          typedef Kokkos::View<SL*, HES> the_whichvecs_type;
          the_whichvecs_type whichVecs (whichVecsLabel, numWhichVecs);
          for (SL i = 0; i < numWhichVecs; ++i) {
            whichVecs(i) = static_cast<SL> (src.whichVectors_[i]);
          }
          // Copy from the selected vectors of src to dst, on the
          // host.  The function ignores the first instance of
          // 'whichVecs' in this case.
          Details::localDeepCopy (dst.getDualView ().h_view,
                                  src.getDualView ().h_view,
                                  dst.isConstantStride (),
                                  src.isConstantStride (),
                                  whichVecs, whichVecs);
          // Sync dst back to the device, since we only copied on the host.
          dst.template sync<DES> ();
        }
      }
      else { // dst is NOT constant stride
        if (src.isConstantStride ()) {
          if (src.getDualView ().modified_device >= src.getDualView ().modified_host) {
            // Copy from the device version of src.
            //
            // whichVecs tells the kernel which vectors (columns) of dst
            // to copy.  Fill whichVecs on the host, and sync to device.
            typedef Kokkos::DualView<DL*, DES> the_whichvecs_type;
            const std::string whichVecsLabel ("MV::deep_copy::whichVecs");
            const DL numWhichVecs = static_cast<DL> (dst.whichVectors_.size ());
            the_whichvecs_type whichVecs (whichVecsLabel, numWhichVecs);
            whichVecs.template modify<HES> ();
            for (DL i = 0; i < numWhichVecs; ++i) {
              whichVecs.h_view(i) = dst.whichVectors_[i];
            }
            // Sync the host version of whichVecs to the device.
            whichVecs.template sync<DES> ();

            // Copy src to the selected vectors of dst, on the device.
            Details::localDeepCopy (dst.getDualView ().d_view,
                                    src.getDualView ().d_view,
                                    dst.isConstantStride (),
                                    src.isConstantStride (),
                                    whichVecs.d_view,
                                    whichVecs.d_view);
            // We can't sync src and repeat the above copy on the
            // host, so sync dst back to the host.
            //
            // FIXME (mfh 29 Jul 2014) This may overwrite columns that
            // don't actually belong to dst's view.
            dst.template sync<HES> ();
          }
          else { // host version of src was the most recently modified
            // Copy from the host version of src.
            //
            // whichVecs tells the kernel which vectors (columns) of src
            // to copy.  Fill whichVecs on the host, and use it there.
            typedef Kokkos::View<DL*, HES> the_whichvecs_type;
            const DL numWhichVecs = static_cast<DL> (dst.whichVectors_.size ());
            the_whichvecs_type whichVecs ("MV::deep_copy::whichVecs", numWhichVecs);
            for (DL i = 0; i < numWhichVecs; ++i) {
              whichVecs(i) = static_cast<DL> (dst.whichVectors_[i]);
            }
            // Copy from src to the selected vectors of dst, on the host.
            Details::localDeepCopy (dst.getDualView ().h_view,
                                    src.getDualView ().h_view,
                                    dst.isConstantStride (),
                                    src.isConstantStride (),
                                    whichVecs, whichVecs);
            // Sync dst back to the device, since we only copied on the host.
            //
            // FIXME (mfh 29 Jul 2014) This may overwrite columns that
            // don't actually belong to dst's view.
            dst.template sync<DES> ();
          }
        }
        else { // neither src nor dst have constant stride
          if (src.getDualView ().modified_device >= src.getDualView ().modified_host) {
            // Copy from the device version of src.
            //
            // whichVectorsDst tells the kernel which vectors
            // (columns) of dst to copy.  Fill it on the host, and
            // sync to device.
            const DL dstNumWhichVecs = static_cast<DL> (dst.whichVectors_.size ());
            Kokkos::DualView<DL*, DES> whichVecsDst ("MV::deep_copy::whichVecsDst",
                                                     dstNumWhichVecs);
            whichVecsDst.template modify<HES> ();
            for (DL i = 0; i < dstNumWhichVecs; ++i) {
              whichVecsDst.h_view(i) = static_cast<DL> (dst.whichVectors_[i]);
            }
            // Sync the host version of whichVecsDst to the device.
            whichVecsDst.template sync<DES> ();

            // whichVectorsSrc tells the kernel which vectors
            // (columns) of src to copy.  Fill it on the host, and
            // sync to device.  Use the destination MultiVector's
            // LocalOrdinal type here.
            const DL srcNumWhichVecs = static_cast<DL> (src.whichVectors_.size ());
            Kokkos::DualView<DL*, DES> whichVecsSrc ("MV::deep_copy::whichVecsSrc",
                                                     srcNumWhichVecs);
            whichVecsSrc.template modify<HES> ();
            for (DL i = 0; i < srcNumWhichVecs; ++i) {
              whichVecsSrc.h_view(i) = static_cast<DL> (src.whichVectors_[i]);
            }
            // Sync the host version of whichVecsSrc to the device.
            whichVecsSrc.template sync<DES> ();

            // Copy from the selected vectors of src to the selected
            // vectors of dst, on the device.
            Details::localDeepCopy (dst.getDualView ().d_view,
                                    src.getDualView ().d_view,
                                    dst.isConstantStride (),
                                    src.isConstantStride (),
                                    whichVecsDst.d_view,
                                    whichVecsSrc.d_view);
          }
          else {
            const DL dstNumWhichVecs = static_cast<DL> (dst.whichVectors_.size ());
            Kokkos::View<DL*, HES> whichVectorsDst ("dstWhichVecs", dstNumWhichVecs);
            for (DL i = 0; i < dstNumWhichVecs; ++i) {
              whichVectorsDst(i) = dst.whichVectors_[i];
            }

            // Use the destination MultiVector's LocalOrdinal type here.
            const DL srcNumWhichVecs = static_cast<DL> (src.whichVectors_.size ());
            Kokkos::View<DL*, HES> whichVectorsSrc ("srcWhichVecs", srcNumWhichVecs);
            for (DL i = 0; i < srcNumWhichVecs; ++i) {
              whichVectorsSrc(i) = src.whichVectors_[i];
            }

            // Copy from the selected vectors of src to the selected
            // vectors of dst, on the host.
            Details::localDeepCopy (dst.getDualView ().h_view,
                                    src.getDualView ().h_view,
                                    dst.isConstantStride (),
                                    src.isConstantStride (),
                                    whichVectorsDst, whichVectorsSrc);
            // We can't sync src and repeat the above copy on the
            // host, so sync dst back to the host.
            //
            // FIXME (mfh 29 Jul 2014) This may overwrite columns that
            // don't actually belong to dst's view.
            dst.template sync<HES> ();
          }
        }
      }
    }
  }

} // namespace Tpetra


namespace Teuchos {

  // Give Teuchos::TypeNameTraits<Tpetra::MultiVector<...> > a
  // human-readable definition.
  template<class SC, class LO, class GO, class NT, const bool classic>
  class TypeNameTraits<Tpetra::MultiVector<SC, LO, GO, NT, classic> > {
  public:
    static std::string name () {
      return std::string ("Tpetra::MultiVector<") +
        TypeNameTraits<SC>::name () + "," +
        TypeNameTraits<LO>::name () + "," +
        TypeNameTraits<GO>::name () + "," +
        TypeNameTraits<NT>::name () + ">";
    }

    static std::string
    concreteName (const Tpetra::MultiVector<SC, LO, GO, NT, classic>&) {
      return name ();
    }
  };
} // namespace Teuchos

#endif // TPETRA_MULTIVECTOR_DECL_HPP