MueLu_LocalLWGraph_kokkos_def.hpp

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#ifndef MUELU_LOCALLWGRAPH_KOKKOS_DEF_HPP
#define MUELU_LOCALLWGRAPH_KOKKOS_DEF_HPP

#include <Kokkos_Core.hpp>

#include <Teuchos_ArrayView.hpp>

#include "MueLu_LocalLWGraph_kokkos_decl.hpp"

namespace MueLu {

  namespace { // anonymous

    template<class LocalOrdinal, class RowType>
    class MaxNumRowEntriesFunctor {
    public:
      MaxNumRowEntriesFunctor(RowType rowPointers) : rowPointers_(rowPointers) { }

      KOKKOS_INLINE_FUNCTION
      void operator()(const LocalOrdinal i, size_t& maxLength) const {
        size_t d = rowPointers_(i+1) - rowPointers_(i);

        maxLength = (d > maxLength ? d : maxLength);
      }

      KOKKOS_INLINE_FUNCTION
      void join(volatile size_t& dest, const volatile size_t& src) {
        dest = (dest > src ? dest : src);
      }

      KOKKOS_INLINE_FUNCTION
      void init(size_t& initValue) {
        initValue = 0;
      }

    private:
      RowType rowPointers_;
    };

  }

  template<class LocalOrdinal, class GlobalOrdinal, class DeviceType>
  LocalLWGraph_kokkos<LocalOrdinal,GlobalOrdinal,Kokkos::Compat::KokkosDeviceWrapperNode<DeviceType>>::
  LocalLWGraph_kokkos(const local_graph_type& graph,
                      const RCP<const map_type>& domainMap)
    : graph_(graph)
  {
    minLocalIndex_ = domainMap->getMinLocalIndex();
    maxLocalIndex_ = domainMap->getMaxLocalIndex();

    MaxNumRowEntriesFunctor<LO,typename local_graph_type::row_map_type> maxNumRowEntriesFunctor(graph_.row_map);
    Kokkos::parallel_reduce("MueLu:LocalLWGraph:LWGraph:maxnonzeros", range_type(0,graph_.numRows()), maxNumRowEntriesFunctor, maxNumRowEntries_);
  }

} //namespace MueLu

#endif // MUELU_LWGRAPH_KOKKOS_DEF_HPP