MueLu_PreserveDirichletAggregationAlgorithm_kokkos_def.hpp

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#ifndef MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_KOKKOS_DEF_HPP
#define MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_KOKKOS_DEF_HPP
 
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
 
#include <Teuchos_Comm.hpp>
#include <Teuchos_CommHelpers.hpp>
 
#include <Xpetra_Vector.hpp>
 
#include "MueLu_PreserveDirichletAggregationAlgorithm_kokkos.hpp"
 
#include "MueLu_LWGraph_kokkos.hpp"
#include "MueLu_Aggregates_kokkos.hpp"
#include "MueLu_Exceptions.hpp"
#include "MueLu_Monitor.hpp"
 
namespace MueLu {
 
  template <class LocalOrdinal, class GlobalOrdinal, class Node>
  void PreserveDirichletAggregationAlgorithm_kokkos<LocalOrdinal, GlobalOrdinal, Node>::
  BuildAggregates(Teuchos::ParameterList const & params,
                  LWGraph_kokkos const & graph,
                  Aggregates_kokkos & aggregates,
                  Kokkos::View<unsigned*, typename LWGraph_kokkos::memory_space>& aggstat,
                  LO& numNonAggregatedNodes) const {
    Monitor m(*this, "BuildAggregates");
 
    typename Kokkos::View<unsigned*, memory_space>::HostMirror aggstatHost
      = Kokkos::create_mirror(aggstat);
    Kokkos::deep_copy(aggstatHost, aggstat);
    std::vector<unsigned> aggStat;
    aggStat.resize(aggstatHost.extent(0));
    for(size_t idx = 0; idx < aggstatHost.extent(0); ++idx) {
      aggStat[idx] = aggstatHost(idx);
    }
 
    bool preserve = params.get<bool>("aggregation: preserve Dirichlet points");
 
    const LO  numRows = graph.GetNodeNumVertices();
    const int myRank  = graph.GetComm()->getRank();
 
    ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
    ArrayRCP<LO> procWinner   = aggregates.GetProcWinner()  ->getDataNonConst(0);
 
    LO numLocalAggregates = aggregates.GetNumAggregates();
 
    for (LO i = 0; i < numRows; i++)
      if (aggStat[i] == BOUNDARY) {
        aggStat[i] = IGNORED;
        numNonAggregatedNodes--;
 
        if (preserve) {
          aggregates.SetIsRoot(i);
 
          vertex2AggId[i] = numLocalAggregates++;
          procWinner  [i] = myRank;
        }
      }
 
    for(size_t idx = 0; idx < aggstatHost.extent(0); ++idx) {
      aggstatHost(idx) = aggStat[idx];
    }
    Kokkos::deep_copy(aggstat, aggstatHost);
 
    // update aggregate object
    aggregates.SetNumAggregates(numLocalAggregates);
  }
 
} // end namespace
 
#endif // HAVE_MUELU_KOKKOS_REFACTOR
#endif // MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_KOKKOS_DEF_HPP