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//                        Kokkos v. 2.0
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#ifndef KOKKOS_IMPL_HOSTTHREADTEAM_HPP
#define KOKKOS_IMPL_HOSTTHREADTEAM_HPP

#include <Kokkos_Core_fwd.hpp>
#include <Kokkos_Pair.hpp>
#include <Kokkos_Atomic.hpp>
#include <Kokkos_ExecPolicy.hpp>
#include <impl/Kokkos_FunctorAdapter.hpp>
#include <impl/Kokkos_FunctorAnalysis.hpp>
#include <impl/Kokkos_HostBarrier.hpp>

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {
namespace Impl {

template< class HostExecSpace >
class HostThreadTeamMember ;

class HostThreadTeamData {
public:

  template< class > friend class HostThreadTeamMember ;

  // Assume upper bounds on number of threads:
  //   pool size       <= 1024 threads
  //   team size       <= 64 threads

  enum : int { max_pool_members  = 1024 };
  enum : int { max_team_members  = 64 };
  enum : int { max_pool_rendezvous = rendezvous_buffer_size( max_pool_members ) };
  enum : int { max_team_rendezvous = rendezvous_buffer_size( max_team_members ) };

private:

  // per-thread scratch memory buffer chunks:
  //
  //   [ pool_members ]     = [ m_pool_members    .. m_pool_rendezvous )
  //   [ pool_rendezvous ]  = [ m_pool_rendezvous .. m_team_rendezvous )
  //   [ team_rendezvous ]  = [ m_team_rendezvous .. m_pool_reduce )
  //   [ pool_reduce ]      = [ m_pool_reduce     .. m_team_reduce )
  //   [ team_reduce ]      = [ m_team_reduce     .. m_team_shared )
  //   [ team_shared ]      = [ m_team_shared     .. m_thread_local )
  //   [ thread_local ]     = [ m_thread_local    .. m_scratch_size )

  enum : int { m_pool_members    = 0 };
  enum : int { m_pool_rendezvous = m_pool_members    + max_pool_members };
  enum : int { m_team_rendezvous = m_pool_rendezvous + max_pool_rendezvous };
  enum : int { m_pool_reduce     = m_team_rendezvous + max_team_rendezvous };

  using pair_int_t = Kokkos::pair<int,int> ;

  pair_int_t  m_work_range ;
  int64_t     m_work_end ;
  int64_t   * m_scratch ;       // per-thread buffer
  int64_t   * m_pool_scratch ;  // == pool[0]->m_scratch
  int64_t   * m_team_scratch ;  // == pool[ 0 + m_team_base ]->m_scratch
  int         m_pool_rank ;
  int         m_pool_size ;
  int         m_team_reduce ;
  int         m_team_shared ;
  int         m_thread_local ;
  int         m_scratch_size ;
  int         m_team_base ;
  int         m_team_rank ;
  int         m_team_size ;
  int         m_team_alloc ;
  int         m_league_rank ;
  int         m_league_size ;
  int         m_work_chunk ;
  int         m_steal_rank ; // work stealing rank
  uint64_t mutable m_pool_rendezvous_step ;
  uint64_t mutable m_team_rendezvous_step ;

  HostThreadTeamData * team_member( int r ) const noexcept
    { return ((HostThreadTeamData**)(m_pool_scratch+m_pool_members))[m_team_base+r]; }

public:

  inline
  int team_rendezvous( int const root ) const noexcept
    {
      return 1 == m_team_size ? 1 :
             rendezvous( m_team_scratch + m_team_rendezvous
                       , m_team_rendezvous_step
                       , m_team_size
                       , ( m_team_rank + m_team_size - root ) % m_team_size
                       );
    }

  inline
  int team_rendezvous() const noexcept
    {
      return 1 == m_team_size ? 1 :
             rendezvous( m_team_scratch + m_team_rendezvous
                       , m_team_rendezvous_step
                       , m_team_size
                       , m_team_rank );
    }

  inline
  void team_rendezvous_release() const noexcept
    {
      if ( 1 < m_team_size ) {
        rendezvous_release( m_team_scratch + m_team_rendezvous
                          , m_team_rendezvous_step );
      }
    }

  inline
  int pool_rendezvous() const noexcept
    {
      static constexpr bool active_wait =
        #if defined( KOKKOS_COMPILER_IBM )
            // If running on IBM POWER architecture the global
            // level rendzvous should immediately yield when
            // waiting for other threads in the pool to arrive.
          false
        #else
          true
        #endif
          ;
      return 1 == m_pool_size ? 1 :
             rendezvous( m_pool_scratch + m_pool_rendezvous
                       , m_pool_rendezvous_step
                       , m_pool_size
                       , m_pool_rank
                       , active_wait
                       );
    }

  inline
  void pool_rendezvous_release() const noexcept
    {
      if ( 1 < m_pool_size ) {
        rendezvous_release( m_pool_scratch + m_pool_rendezvous, m_pool_rendezvous_step );
      }
    }

  //----------------------------------------

  constexpr HostThreadTeamData() noexcept
    : m_work_range(-1,-1)
    , m_work_end(0)
    , m_scratch(0)
    , m_pool_scratch(0)
    , m_team_scratch(0)
    , m_pool_rank(0)
    , m_pool_size(1)
    , m_team_reduce(0)
    , m_team_shared(0)
    , m_thread_local(0)
    , m_scratch_size(0)
    , m_team_base(0)
    , m_team_rank(0)
    , m_team_size(1)
    , m_team_alloc(1)
    , m_league_rank(0)
    , m_league_size(1)
    , m_work_chunk(0)
    , m_steal_rank(0)
    , m_pool_rendezvous_step(0)
    , m_team_rendezvous_step(0)
    {}

  //----------------------------------------
  // Organize array of members into a pool.
  // The 0th member is the root of the pool.
  // Requires: members are not already in a pool.
  // Requires: called by one thread.
  // Pool members are ordered as "close" - sorted by NUMA and then CORE
  // Each thread is its own team with team_size == 1.
  static void organize_pool( HostThreadTeamData * members[]
                           , const int size );

  // Called by each thread within the pool
  void disband_pool();

  //----------------------------------------
  // Each thread within a pool organizes itself into a team.
  // Must be called by all threads of the pool.
  // Organizing threads into a team performs a barrier across the
  // entire pool to insure proper initialization of the team
  // rendezvous mechanism before a team rendezvous can be performed.
  //
  // Return true  if a valid member of a team.
  // Return false if not a member and thread should be idled.
  int organize_team( const int team_size );

  // Each thread within a pool disbands itself from current team.
  // Each thread becomes its own team with team_size == 1.
  // Must be called by all threads of the pool.
  void disband_team();

  //----------------------------------------

  constexpr int pool_rank() const { return m_pool_rank ; }
  constexpr int pool_size() const { return m_pool_size ; }

  HostThreadTeamData * pool_member( int r ) const noexcept
    { return ((HostThreadTeamData**)(m_pool_scratch+m_pool_members))[r]; }

  //----------------------------------------

private:

  enum : int { mask_to_16 = 0x0f }; // align to 16 bytes
  enum : int { shift_to_8 = 3 };    // size to 8 bytes

public:

  static constexpr int align_to_int64( int n )
    { return ( ( n + mask_to_16 ) & ~mask_to_16 ) >> shift_to_8 ; }

  constexpr int pool_reduce_bytes() const
    { return m_scratch_size ? sizeof(int64_t) * ( m_team_reduce - m_pool_reduce ) : 0 ; }

  constexpr int team_reduce_bytes() const
    { return sizeof(int64_t) * ( m_team_shared - m_team_reduce ); }

  constexpr int team_shared_bytes() const
    { return sizeof(int64_t) * ( m_thread_local - m_team_shared ); }

  constexpr int thread_local_bytes() const
    { return sizeof(int64_t) * ( m_scratch_size - m_thread_local ); }

  constexpr int scratch_bytes() const
    { return sizeof(int64_t) * m_scratch_size ; }

  // Memory chunks:

  int64_t * scratch_buffer() const noexcept
    { return m_scratch ; }

  int64_t * pool_reduce() const noexcept
    { return m_pool_scratch + m_pool_reduce ; }

  int64_t * pool_reduce_local() const noexcept
    { return m_scratch + m_pool_reduce ; }

  int64_t * team_reduce() const noexcept
    { return m_team_scratch + m_team_reduce ; }

  int64_t * team_reduce_local() const noexcept
    { return m_scratch + m_team_reduce ; }

  int64_t * team_shared() const noexcept
    { return m_team_scratch + m_team_shared ; }

  int64_t * local_scratch() const noexcept
    { return m_scratch + m_thread_local ; }

  // Given:
  //   pool_reduce_size  = number bytes for pool reduce
  //   team_reduce_size  = number bytes for team reduce
  //   team_shared_size  = number bytes for team shared memory
  //   thread_local_size = number bytes for thread local memory
  // Return:
  //   total number of bytes that must be allocated
  static
  size_t scratch_size( int pool_reduce_size
                     , int team_reduce_size
                     , int team_shared_size
                     , int thread_local_size )
    {
      pool_reduce_size  = align_to_int64( pool_reduce_size );
      team_reduce_size  = align_to_int64( team_reduce_size );
      team_shared_size  = align_to_int64( team_shared_size );
      thread_local_size = align_to_int64( thread_local_size );

      const size_t total_bytes = (
        m_pool_reduce +
        pool_reduce_size +
        team_reduce_size +
        team_shared_size +
        thread_local_size ) * sizeof(int64_t);

      return total_bytes ;
    }

  // Given:
  //   alloc_ptr         = pointer to allocated memory
  //   alloc_size        = number bytes of allocated memory
  //   pool_reduce_size  = number bytes for pool reduce/scan operations
  //   team_reduce_size  = number bytes for team reduce/scan operations
  //   team_shared_size  = number bytes for team-shared memory
  //   thread_local_size = number bytes for thread-local memory
  // Return:
  //   total number of bytes that must be allocated
  void scratch_assign( void * const alloc_ptr
                     , size_t const alloc_size
                     , int pool_reduce_size
                     , int team_reduce_size
                     , int team_shared_size
                     , int /* thread_local_size */ )
    {
      pool_reduce_size  = align_to_int64( pool_reduce_size );
      team_reduce_size  = align_to_int64( team_reduce_size );
      team_shared_size  = align_to_int64( team_shared_size );
      // thread_local_size = align_to_int64( thread_local_size );

      m_scratch      = (int64_t *) alloc_ptr ;
      m_team_reduce  = m_pool_reduce + pool_reduce_size ;
      m_team_shared  = m_team_reduce + team_reduce_size ;
      m_thread_local = m_team_shared + team_shared_size ;
      m_scratch_size = align_to_int64( alloc_size );

#if 0
fprintf(stdout,"HostThreadTeamData::scratch_assign { %d %d %d %d %d %d %d }\n"
       , int(m_pool_members)
       , int(m_pool_rendezvous)
       , int(m_pool_reduce)
       , int(m_team_reduce)
       , int(m_team_shared)
       , int(m_thread_local)
       , int(m_scratch_size)
       );
fflush(stdout);
#endif

    }

  //----------------------------------------
  // Get a work index within the range.
  // First try to steal from beginning of own teams's partition.
  // If that fails then try to steal from end of another teams' partition.
  int get_work_stealing() noexcept ;

  //----------------------------------------
  // Set the initial work partitioning of [ 0 .. length ) among the teams
  // with granularity of chunk

  void set_work_partition( int64_t const length
                         , int     const chunk ) noexcept
    {
      // Minimum chunk size to insure that
      //   m_work_end < std::numeric_limits<int>::max() * m_work_chunk

      int const chunk_min = ( length + std::numeric_limits<int>::max() )
                            / std::numeric_limits<int>::max();

      m_work_end   = length ;
      m_work_chunk = std::max( chunk , chunk_min );

      // Number of work chunks and partitioning of that number:
      int const num  = ( m_work_end + m_work_chunk - 1 ) / m_work_chunk ;
      int const part = ( num + m_league_size - 1 ) / m_league_size ;

      m_work_range.first  = part * m_league_rank ;
      m_work_range.second = m_work_range.first + part ;

      // Steal from next team, round robin
      // The next team is offset by m_team_alloc if it fits in the pool.

      m_steal_rank = m_team_base + m_team_alloc + m_team_size <= m_pool_size ?
                     m_team_base + m_team_alloc : 0 ;
    }

  std::pair<int64_t,int64_t> get_work_partition() noexcept
    {
      int64_t first = m_work_range.first;
      int64_t second = m_work_range.second;
      first *= m_work_chunk;
      second *= m_work_chunk;
      return std::pair<int64_t,int64_t>
        ( first
        , second < m_work_end ? second : m_work_end );
    }

  std::pair<int64_t,int64_t> get_work_stealing_chunk() noexcept
    {
      std::pair<int64_t,int64_t> x(-1,-1);

      const int i = get_work_stealing();

      if ( 0 <= i ) {
        x.first  = m_work_chunk * i ;
        x.second = x.first + m_work_chunk < m_work_end
                 ? x.first + m_work_chunk : m_work_end ;
      }

      return x ;
    }
};

//----------------------------------------------------------------------------

template< class HostExecSpace >
class HostThreadTeamMember {
public:

  using scratch_memory_space = typename HostExecSpace::scratch_memory_space ;

private:

  scratch_memory_space m_scratch ;
  HostThreadTeamData & m_data ;
  int const            m_league_rank ;
  int const            m_league_size ;

public:

  constexpr HostThreadTeamMember( HostThreadTeamData & arg_data ) noexcept
    : m_scratch( arg_data.team_shared() , arg_data.team_shared_bytes() )
    , m_data( arg_data )
    , m_league_rank(0)
    , m_league_size(1)
    {}

  constexpr HostThreadTeamMember( HostThreadTeamData & arg_data
                                , int const            arg_league_rank
                                , int const            arg_league_size
                                ) noexcept
    : m_scratch( arg_data.team_shared()
               , arg_data.team_shared_bytes()
               , arg_data.team_shared()
               , arg_data.team_shared_bytes() )
    , m_data( arg_data )
    , m_league_rank( arg_league_rank )
    , m_league_size( arg_league_size )
    {}

  ~HostThreadTeamMember() = default ;
  HostThreadTeamMember() = delete ;
  HostThreadTeamMember( HostThreadTeamMember && ) = default ;
  HostThreadTeamMember( HostThreadTeamMember const & ) = default ;
  HostThreadTeamMember & operator = ( HostThreadTeamMember && ) = default ;
  HostThreadTeamMember & operator = ( HostThreadTeamMember const & ) = default ;

  //----------------------------------------

  KOKKOS_INLINE_FUNCTION
  int team_rank() const noexcept { return m_data.m_team_rank ; }

  KOKKOS_INLINE_FUNCTION
  int team_size() const noexcept { return m_data.m_team_size ; }

  KOKKOS_INLINE_FUNCTION
  int league_rank() const noexcept { return m_league_rank ; }

  KOKKOS_INLINE_FUNCTION
  int league_size() const noexcept { return m_league_size ; }

  //----------------------------------------

  KOKKOS_INLINE_FUNCTION
  const scratch_memory_space & team_shmem() const
    { return m_scratch.set_team_thread_mode(0,1,0); }

  KOKKOS_INLINE_FUNCTION
  const scratch_memory_space & team_scratch(int) const
    { return m_scratch.set_team_thread_mode(0,1,0); }

  KOKKOS_INLINE_FUNCTION
  const scratch_memory_space & thread_scratch(int) const
    { return m_scratch.set_team_thread_mode(0,m_data.m_team_size,m_data.m_team_rank); }

  //--------------------------------------------------------------------------
  // Team collectives
  //--------------------------------------------------------------------------

  KOKKOS_INLINE_FUNCTION void team_barrier() const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      if ( m_data.team_rendezvous() ) m_data.team_rendezvous_release();
    }
#else
    {}
#endif

  //--------------------------------------------------------------------------

  template< typename T >
  KOKKOS_INLINE_FUNCTION
  void team_broadcast( T & value , const int source_team_rank ) const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      if ( 1 < m_data.m_team_size ) {
        T volatile * const shared_value = (T*) m_data.team_reduce();

        // Don't overwrite shared memory until all threads arrive

        if ( m_data.team_rendezvous( source_team_rank ) ) {
          // All threads have entered 'team_rendezvous'
          // only this thread returned from 'team_rendezvous'
          // with a return value of 'true'

          *shared_value = value ;

          m_data.team_rendezvous_release();
          // This thread released all other threads from 'team_rendezvous'
          // with a return value of 'false'
        }
        else {
          value = *shared_value ;
        }
      }
    }
#else
    { Kokkos::abort("HostThreadTeamMember team_broadcast\n"); }
#endif

  //--------------------------------------------------------------------------

  template< class Closure , typename T >
  KOKKOS_INLINE_FUNCTION
  void team_broadcast( Closure const & f , T & value , const int source_team_rank) const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      T volatile * const shared_value = (T*) m_data.team_reduce();

      // Don't overwrite shared memory until all threads arrive

      if ( m_data.team_rendezvous(source_team_rank) ) {

        // All threads have entered 'team_rendezvous'
        // only this thread returned from 'team_rendezvous'
        // with a return value of 'true'

        f( value );

        if ( 1 < m_data.m_team_size ) { *shared_value = value ; }

        m_data.team_rendezvous_release();
        // This thread released all other threads from 'team_rendezvous'
        // with a return value of 'false'
      }
      else {
        value = *shared_value ;
      }
    }
#else
    { Kokkos::abort("HostThreadTeamMember team_broadcast\n"); }
#endif

  //--------------------------------------------------------------------------
  // team_reduce( Sum(result) );
  // team_reduce( Min(result) );
  // team_reduce( Max(result) );

  template< typename ReducerType >
  KOKKOS_INLINE_FUNCTION
  typename std::enable_if< is_reducer< ReducerType >::value >::type
  team_reduce( ReducerType const & reducer ) const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      if ( 1 < m_data.m_team_size ) {

        using value_type = typename ReducerType::value_type ;

        if ( 0 != m_data.m_team_rank ) {
          // Non-root copies to their local buffer:
          /*reducer.copy( (value_type*) m_data.team_reduce_local()
                      , reducer.data() );*/
          *((value_type*) m_data.team_reduce_local()) = reducer.reference();
        }

        // Root does not overwrite shared memory until all threads arrive
        // and copy to their local buffer.

        if ( m_data.team_rendezvous() ) {
          // All threads have entered 'team_rendezvous'
          // only this thread returned from 'team_rendezvous'
          // with a return value of 'true'
          //
          // This thread sums contributed values
          for ( int i = 1 ; i < m_data.m_team_size ; ++i ) {
            value_type * const src =
              (value_type*) m_data.team_member(i)->team_reduce_local();

            reducer.join( reducer.reference(), *src);
          }

          // Copy result to root member's buffer:
          // reducer.copy( (value_type*) m_data.team_reduce() , reducer.data() );
          *((value_type*) m_data.team_reduce()) = reducer.reference();
          m_data.team_rendezvous_release();
          // This thread released all other threads from 'team_rendezvous'
          // with a return value of 'false'
        }
        else {
          // Copy from root member's buffer:
          reducer.reference() = *((value_type*) m_data.team_reduce());
        }
      }
    }
#else
    { Kokkos::abort("HostThreadTeamMember team_reduce\n"); }
#endif

  //--------------------------------------------------------------------------

  /*template< typename ValueType , class JoinOp >
  KOKKOS_INLINE_FUNCTION
  ValueType
  team_reduce( ValueType const & value
             , JoinOp    const & join ) const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      if ( 0 != m_data.m_team_rank ) {
        // Non-root copies to their local buffer:
        *((ValueType*) m_data.team_reduce_local()) = value ;
      }

      // Root does not overwrite shared memory until all threads arrive
      // and copy to their local buffer.

      if ( m_data.team_rendezvous() ) {
        const Impl::Reducer< ValueType , JoinOp > reducer( join );

        // All threads have entered 'team_rendezvous'
        // only this thread returned from 'team_rendezvous'
        // with a return value of 'true'
        //
        // This thread sums contributed values

        ValueType * const dst = (ValueType*) m_data.team_reduce_local();

        *dst = value ;

        for ( int i = 1 ; i < m_data.m_team_size ; ++i ) {
          ValueType * const src =
            (ValueType*) m_data.team_member(i)->team_reduce_local();

          reducer.join( dst , src );
        }

        m_data.team_rendezvous_release();
        // This thread released all other threads from 'team_rendezvous'
        // with a return value of 'false'
      }

      return *((ValueType*) m_data.team_reduce());
    }
#else
    { Kokkos::abort("HostThreadTeamMember team_reduce\n"); return ValueType(); }
#endif*/


  template< typename T >
  KOKKOS_INLINE_FUNCTION
  T team_scan( T const & value , T * const global = 0 ) const noexcept
#if defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
    {
      if ( 0 != m_data.m_team_rank ) {
        // Non-root copies to their local buffer:
        ((T*) m_data.team_reduce_local())[1] = value ;
      }

      // Root does not overwrite shared memory until all threads arrive
      // and copy to their local buffer.

      if ( m_data.team_rendezvous() ) {
        // All threads have entered 'team_rendezvous'
        // only this thread returned from 'team_rendezvous'
        // with a return value of 'true'
        //
        // This thread scans contributed values

        {
          T * prev = (T*) m_data.team_reduce_local();

          prev[0] = 0 ;
          prev[1] = value ;

          for ( int i = 1 ; i < m_data.m_team_size ; ++i ) {
            T * const ptr = (T*) m_data.team_member(i)->team_reduce_local();

            ptr[0] = prev[0] + prev[1] ;

            prev = ptr ;
          }
        }

        // If adding to global value then atomic_fetch_add to that value
        // and sum previous value to every entry of the scan.
        if ( global ) {
          T * prev = (T*) m_data.team_reduce_local();

          {
            T * ptr  = (T*) m_data.team_member( m_data.m_team_size - 1 )->team_reduce_local();
            prev[0] = Kokkos::atomic_fetch_add( global , ptr[0] + ptr[1] );
          }

          for ( int i = 1 ; i < m_data.m_team_size ; ++i ) {
            T * ptr = (T*) m_data.team_member(i)->team_reduce_local();
            ptr[0] += prev[0] ;
          }
        }

        m_data.team_rendezvous_release();
      }

      return ((T*) m_data.team_reduce_local())[0];
    }
#else
    { Kokkos::abort("HostThreadTeamMember team_scan\n"); return T(); }
#endif

};


}} /* namespace Kokkos::Impl */

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {

template<class Space,typename iType>
KOKKOS_INLINE_FUNCTION
Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >
TeamThreadRange( Impl::HostThreadTeamMember<Space> const & member
               , iType const & count )
{
  return
    Impl::TeamThreadRangeBoundariesStruct
      <iType,Impl::HostThreadTeamMember<Space> >(member,0,count);
}

template<class Space, typename iType1, typename iType2>
KOKKOS_INLINE_FUNCTION
Impl::TeamThreadRangeBoundariesStruct
  < typename std::common_type< iType1, iType2 >::type
  , Impl::HostThreadTeamMember<Space> >
TeamThreadRange( Impl::HostThreadTeamMember<Space> const & member
               , iType1 const & begin , iType2 const & end )
{
  return
    Impl::TeamThreadRangeBoundariesStruct
      < typename std::common_type< iType1, iType2 >::type
      , Impl::HostThreadTeamMember<Space> >( member , begin , end );
}

template<class Space, typename iType>
KOKKOS_INLINE_FUNCTION
Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >
ThreadVectorRange
  ( Impl::HostThreadTeamMember<Space> const & member
  , const iType & count )
{
  return Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >(member,count);
}

//----------------------------------------------------------------------------
/** \brief  Inter-thread parallel_for.
 *
 * Executes lambda(iType i) for each i=[0..N)
 *
 * The range [0..N) is mapped to all threads of the the calling thread team.
*/
template<typename iType, class Space, class Closure>
KOKKOS_INLINE_FUNCTION
void parallel_for
  ( Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> > const & loop_boundaries
  , Closure const & closure
  )
{
  for( iType i = loop_boundaries.start
     ; i <  loop_boundaries.end
     ; i += loop_boundaries.increment ) {
    closure (i);
  }
}

template<typename iType, class Space, class Closure>
KOKKOS_INLINE_FUNCTION
void parallel_for
  ( Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> > const & loop_boundaries
  , Closure const & closure
  )
{
  #ifdef KOKKOS_ENABLE_PRAGMA_IVDEP
  #pragma ivdep
  #endif
  for( iType i = loop_boundaries.start
     ; i <  loop_boundaries.end
     ; i += loop_boundaries.increment ) {
    closure (i);
  }
}

//----------------------------------------------------------------------------

template< typename iType, class Space, class Closure, class Reducer >
KOKKOS_INLINE_FUNCTION
typename std::enable_if< Kokkos::is_reducer< Reducer >::value >::type
parallel_reduce
  ( Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >
             const & loop_boundaries
  , Closure  const & closure
  , Reducer  const & reducer
  )
{
  reducer.init( reducer.reference() );

  for( iType i = loop_boundaries.start
     ; i <  loop_boundaries.end
     ; i += loop_boundaries.increment ) {
    closure( i , reducer.reference() );
  }

  loop_boundaries.thread.team_reduce( reducer );
}

template< typename iType, class Space, typename Closure, typename ValueType >
KOKKOS_INLINE_FUNCTION
typename std::enable_if< ! Kokkos::is_reducer<ValueType>::value >::type
parallel_reduce
  ( Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >
             const & loop_boundaries
  , Closure  const & closure
  , ValueType      & result
  )
{
  Kokkos::Experimental::Sum<ValueType> reducer( result );

  reducer.init( result );

  for( iType i = loop_boundaries.start
     ; i <  loop_boundaries.end
     ; i += loop_boundaries.increment ) {
    closure( i , reducer.reference() );
  }

  loop_boundaries.thread.team_reduce( reducer );
}

/*template< typename iType, class Space
         , class Closure, class Joiner , typename ValueType >
KOKKOS_INLINE_FUNCTION
void parallel_reduce
  ( Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >
             const & loop_boundaries
  , Closure  const & closure
  , Joiner   const & joiner
  , ValueType      & result
  )
{
  Impl::Reducer< ValueType , Joiner > reducer( joiner , & result );

  reducer.init( reducer.data() );

  for( iType i = loop_boundaries.start
     ; i <  loop_boundaries.end
     ; i += loop_boundaries.increment ) {
    closure( i , reducer.reference() );
  }

  loop_boundaries.thread.team_reduce( reducer );
}*/

//----------------------------------------------------------------------------
/** \brief  Inter-thread vector parallel_reduce.
 *
 *  Executes lambda(iType i, ValueType & val) for each i=[0..N)
 *
 *  The range [0..N) is mapped to all threads of the
 *  calling thread team and a summation of  val is
 *  performed and put into result.
 */
template< typename iType, class Space , class Lambda, typename ValueType >
KOKKOS_INLINE_FUNCTION
typename std::enable_if< ! Kokkos::is_reducer<ValueType>::value >::type
parallel_reduce
  (const Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >& loop_boundaries,
   const Lambda & lambda,
   ValueType& result)
{
  result = ValueType();
  for( iType i =  loop_boundaries.start ;
             i <  loop_boundaries.end ;
             i += loop_boundaries.increment) {
    lambda(i,result);
  }
}

template< typename iType, class Space , class Lambda, typename ReducerType >
KOKKOS_INLINE_FUNCTION
typename std::enable_if< Kokkos::is_reducer< ReducerType >::value >::type
parallel_reduce
  (const Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >& loop_boundaries,
   const Lambda & lambda,
   const ReducerType& reducer)
{
  reducer.init(reducer.reference());
  for( iType i =  loop_boundaries.start ;
             i <  loop_boundaries.end ;
             i += loop_boundaries.increment) {
    lambda(i,reducer.reference());
  }
}

/** \brief  Intra-thread vector parallel_reduce.
 *
 *  Executes lambda(iType i, ValueType & val) for each i=[0..N)
 *
 *  The range [0..N) is mapped to all vector lanes of the the
 *  calling thread and a reduction of val is performed using
 *  JoinType(ValueType& val, const ValueType& update)
 *  and put into init_result.
 *  The input value of init_result is used as initializer for
 *  temporary variables of ValueType. Therefore * the input
 *  value should be the neutral element with respect to the
 *  join operation (e.g. '0 for +-' or * '1 for *').
 */
template< typename iType, class Space
        , class Lambda, class JoinType , typename ValueType >
KOKKOS_INLINE_FUNCTION
void parallel_reduce
  (const Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> >& loop_boundaries,
   const Lambda & lambda,
   const JoinType & join,
   ValueType& result)
{
  for( iType i =  loop_boundaries.start ;
             i <  loop_boundaries.end ;
             i += loop_boundaries.increment ) {
    lambda(i,result);
  }
}

//----------------------------------------------------------------------------

template< typename iType, class Space, class Closure >
KOKKOS_INLINE_FUNCTION
void parallel_scan
  ( Impl::TeamThreadRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> > const & loop_boundaries
  , Closure const & closure
  )
{
  // Extract ValueType from the closure

  using value_type =
    typename Kokkos::Impl::FunctorAnalysis
      < Kokkos::Impl::FunctorPatternInterface::SCAN
      , void
      , Closure >::value_type ;

  value_type accum = 0 ;

  // Intra-member scan
  for ( iType i = loop_boundaries.start
      ; i <  loop_boundaries.end
      ; i += loop_boundaries.increment ) {
    closure(i,accum,false);
  }

  // 'accum' output is the exclusive prefix sum
  accum = loop_boundaries.thread.team_scan(accum);

  for ( iType i = loop_boundaries.start
      ; i <  loop_boundaries.end
      ; i += loop_boundaries.increment ) {
    closure(i,accum,true);
  }
}


template< typename iType, class Space, class ClosureType >
KOKKOS_INLINE_FUNCTION
void parallel_scan
  ( Impl::ThreadVectorRangeBoundariesStruct<iType,Impl::HostThreadTeamMember<Space> > const & loop_boundaries
  , ClosureType const & closure
  )
{
  using value_type = typename
    Kokkos::Impl::FunctorAnalysis
      < Impl::FunctorPatternInterface::SCAN
      , void
      , ClosureType >::value_type ;

  value_type scan_val = value_type();

#ifdef KOKKOS_ENABLE_PRAGMA_IVDEP
#pragma ivdep
#endif
  for ( iType i = loop_boundaries.start
      ; i <  loop_boundaries.end
      ; i += loop_boundaries.increment ) {
    closure(i,scan_val,true);
  }
}

//----------------------------------------------------------------------------

template< class Space >
KOKKOS_INLINE_FUNCTION
Impl::ThreadSingleStruct<Impl::HostThreadTeamMember<Space> >
PerTeam(const Impl::HostThreadTeamMember<Space> & member )
{
  return Impl::ThreadSingleStruct<Impl::HostThreadTeamMember<Space> >(member);
}

template< class Space >
KOKKOS_INLINE_FUNCTION
Impl::VectorSingleStruct<Impl::HostThreadTeamMember<Space> >
PerThread(const Impl::HostThreadTeamMember<Space> & member)
{
  return Impl::VectorSingleStruct<Impl::HostThreadTeamMember<Space> >(member);
}

template< class Space , class FunctorType >
KOKKOS_INLINE_FUNCTION
void single( const Impl::ThreadSingleStruct< Impl::HostThreadTeamMember<Space> > & single , const FunctorType & functor )
{
  // 'single' does not perform a barrier.
  if ( single.team_member.team_rank() == 0 ) functor();
}

template< class Space , class FunctorType , typename ValueType >
KOKKOS_INLINE_FUNCTION
void single( const Impl::ThreadSingleStruct< Impl::HostThreadTeamMember<Space> > & single , const FunctorType & functor , ValueType & val )
{
  single.team_member.team_broadcast( functor , val , 0 );
}

template< class Space , class FunctorType >
KOKKOS_INLINE_FUNCTION
void single( const Impl::VectorSingleStruct< Impl::HostThreadTeamMember<Space> > & , const FunctorType & functor )
{
  functor();
}

template< class Space , class FunctorType , typename ValueType >
KOKKOS_INLINE_FUNCTION
void single( const Impl::VectorSingleStruct< Impl::HostThreadTeamMember<Space> > & , const FunctorType & functor , ValueType & val )
{
  functor(val);
}

} /* namespace Kokkos */

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

#endif /* #ifndef KOKKOS_IMPL_HOSTTHREADTEAM_HPP */

