/*
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// 
//                        Kokkos v. 2.0
//              Copyright (2014) Sandia Corporation
// 
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#if defined( KOKKOS_ATOMIC_HPP ) && ! defined( KOKKOS_ATOMIC_GENERIC_HPP )
#define KOKKOS_ATOMIC_GENERIC_HPP
#include <Kokkos_Macros.hpp>

// Combination operands to be used in an Compare and Exchange based atomic operation
namespace Kokkos {
namespace Impl {

template<class Scalar1, class Scalar2>
struct MaxOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return (val1 > val2 ? val1 : val2);
  }
};

template<class Scalar1, class Scalar2>
struct MinOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return (val1 < val2 ? val1 : val2);
  }
};

template<class Scalar1, class Scalar2>
struct AddOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1+val2;
  }
};

template<class Scalar1, class Scalar2>
struct SubOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1-val2;
  }
};

template<class Scalar1, class Scalar2>
struct MulOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1*val2;
  }
};

template<class Scalar1, class Scalar2>
struct DivOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1/val2;
  }
};

template<class Scalar1, class Scalar2>
struct ModOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1%val2;
  }
};

template<class Scalar1, class Scalar2>
struct AndOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1&val2;
  }
};

template<class Scalar1, class Scalar2>
struct OrOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1|val2;
  }
};

template<class Scalar1, class Scalar2>
struct XorOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1^val2;
  }
};

template<class Scalar1, class Scalar2>
struct LShiftOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1<<val2;
  }
};

template<class Scalar1, class Scalar2>
struct RShiftOper {
  KOKKOS_FORCEINLINE_FUNCTION
  static Scalar1 apply(const Scalar1& val1, const Scalar2& val2) {
    return val1>>val2;
  }
};

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_oper( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if< sizeof(T) != sizeof(int) &&
                                    sizeof(T) == sizeof(unsigned long long int) , const T >::type val )
{
  union { unsigned long long int i ; T t ; } oldval , assume , newval ;

  oldval.t = *dest ;

  do {
    assume.i = oldval.i ;
    newval.t = Oper::apply(assume.t, val) ;
    oldval.i = Kokkos::atomic_compare_exchange( (unsigned long long int*)dest , assume.i , newval.i );
  } while ( assume.i != oldval.i );

  return oldval.t ;
}

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_oper_fetch( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if< sizeof(T) != sizeof(int) &&
                                    sizeof(T) == sizeof(unsigned long long int) , const T >::type val )
{
  union { unsigned long long int i ; T t ; } oldval , assume , newval ;

  oldval.t = *dest ;

  do {
    assume.i = oldval.i ;
    newval.t = Oper::apply(assume.t, val) ;
    oldval.i = Kokkos::atomic_compare_exchange( (unsigned long long int*)dest , assume.i , newval.i );
  } while ( assume.i != oldval.i );

  return newval.t ;
}

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_oper( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if< sizeof(T) == sizeof(int) , const T >::type val )
{
  union { int i ; T t ; } oldval , assume , newval ;

  oldval.t = *dest ;

  do {
    assume.i = oldval.i ;
    newval.t = Oper::apply(assume.t, val) ;
    oldval.i = Kokkos::atomic_compare_exchange( (int*)dest , assume.i , newval.i );
  } while ( assume.i != oldval.i );

  return oldval.t ;
}

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_oper_fetch( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if< sizeof(T) == sizeof(int), const T >::type val )
{
  union { int i ; T t ; } oldval , assume , newval ;

  oldval.t = *dest ;

  do {
    assume.i = oldval.i ;
    newval.t = Oper::apply(assume.t, val) ;
    oldval.i = Kokkos::atomic_compare_exchange( (int*)dest , assume.i , newval.i );
  } while ( assume.i != oldval.i );

  return newval.t ;
}

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_oper( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if<
                ( sizeof(T) != 4 )
             && ( sizeof(T) != 8 )
          #if defined(KOKKOS_ENABLE_ASM) && defined(KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST)
             && ( sizeof(T) != 16 )
          #endif
           , const T >::type val )
{

#ifdef KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST
  while( !Impl::lock_address_host_space( (void*) dest ) );
  T return_val = *dest;
  *dest = Oper::apply(return_val, val);
  Impl::unlock_address_host_space( (void*) dest );
  return return_val;
#else
  // This is a way to (hopefully) avoid dead lock in a warp
  T return_val;
  int done = 0;
  unsigned int active = __ballot(1);
  unsigned int done_active = 0;
  while (active!=done_active) {
    if(!done) {
      if( Impl::lock_address_cuda_space( (void*) dest ) ) {
        return_val = *dest;
        *dest = Oper::apply(return_val, val);;
        Impl::unlock_address_cuda_space( (void*) dest );
        done=1;
      }
    }
    done_active = __ballot(done);
  }
  return return_val;
#endif
}

template < class Oper, typename T >
KOKKOS_INLINE_FUNCTION
T atomic_oper_fetch( const Oper& op, volatile T * const dest ,
  typename Kokkos::Impl::enable_if<
                ( sizeof(T) != 4 )
             && ( sizeof(T) != 8 )
          #if defined(KOKKOS_ENABLE_ASM) && defined(KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST)
             && ( sizeof(T) != 16 )
          #endif
           , const T >::type& val )
{

#ifdef KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST
  while( !Impl::lock_address_host_space( (void*) dest ) );
  T return_val = Oper::apply(*dest, val);
  *dest = return_val;
  Impl::unlock_address_host_space( (void*) dest );
  return return_val;
#else
  T return_val;
  // This is a way to (hopefully) avoid dead lock in a warp
  int done = 0;
  unsigned int active = __ballot(1);
  unsigned int done_active = 0;
  while (active!=done_active) {
    if(!done) {
      if( Impl::lock_address_cuda_space( (void*) dest ) ) {
        return_val = Oper::apply(*dest, val);
        *dest = return_val;
        Impl::unlock_address_cuda_space( (void*) dest );
        done=1;
      }
    }
    done_active = __ballot(done);
  }
  return return_val;
#endif
}

}
}

namespace Kokkos {

// Fetch_Oper atomics: return value before operation
template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_max(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::MaxOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_min(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::MinOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_mul(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::MulOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_div(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::DivOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_mod(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::ModOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_and(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::AndOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_or(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::OrOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_xor(volatile T * const dest, const T val) {
  return Impl::atomic_fetch_oper(Impl::XorOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_lshift(volatile T * const dest, const unsigned int val) {
  return Impl::atomic_fetch_oper(Impl::LShiftOper<T,const unsigned int>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_fetch_rshift(volatile T * const dest, const unsigned int val) {
  return Impl::atomic_fetch_oper(Impl::RShiftOper<T,const unsigned int>(),dest,val);
}


// Oper Fetch atomics: return value after operation
template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_max_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::MaxOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_min_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::MinOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_mul_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::MulOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_div_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::DivOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_mod_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::ModOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_and_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::AndOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_or_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::OrOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_xor_fetch(volatile T * const dest, const T val) {
  return Impl::atomic_oper_fetch(Impl::XorOper<T,const T>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_lshift_fetch(volatile T * const dest, const unsigned int val) {
  return Impl::atomic_oper_fetch(Impl::LShiftOper<T,const unsigned int>(),dest,val);
}

template < typename T >
KOKKOS_INLINE_FUNCTION
T atomic_rshift_fetch(volatile T * const dest, const unsigned int val) {
  return Impl::atomic_oper_fetch(Impl::RShiftOper<T,const unsigned int>(),dest,val);
}


}
#endif
