/*
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//                        Kokkos v. 2.0
//              Copyright (2014) Sandia Corporation
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#include <Kokkos_Core.hpp>

namespace TestAtomic {

// Struct for testing arbitrary size atomics

template<int N>
struct SuperScalar {
  double val[N];

  KOKKOS_INLINE_FUNCTION
  SuperScalar() {
    for(int i=0; i<N; i++)
      val[i] = 0.0;
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar(const SuperScalar& src) {
    for(int i=0; i<N; i++)
      val[i] = src.val[i];
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar(const volatile SuperScalar& src) {
    for(int i=0; i<N; i++)
      val[i] = src.val[i];
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar& operator = (const SuperScalar& src) {
    for(int i=0; i<N; i++)
      val[i] = src.val[i];
    return *this;
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar& operator = (const volatile SuperScalar& src) {
    for(int i=0; i<N; i++)
      val[i] = src.val[i];
    return *this;
  }

  KOKKOS_INLINE_FUNCTION
  volatile SuperScalar& operator = (const SuperScalar& src) volatile  {
    for(int i=0; i<N; i++)
      val[i] = src.val[i];
    return *this;
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar operator + (const SuperScalar& src) {
    SuperScalar tmp = *this;
    for(int i=0; i<N; i++)
      tmp.val[i] += src.val[i];
    return tmp;
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar& operator += (const double& src) {
    for(int i=0; i<N; i++)
      val[i] += 1.0*(i+1)*src;
    return *this;
  }

  KOKKOS_INLINE_FUNCTION
  SuperScalar& operator += (const SuperScalar& src) {
    for(int i=0; i<N; i++)
      val[i] += src.val[i];
    return *this;
  }

  KOKKOS_INLINE_FUNCTION
  bool operator == (const SuperScalar& src) {
    bool compare = true;
    for(int i=0; i<N; i++)
      compare = compare && ( val[i] == src.val[i]);
    return compare;
  }

  KOKKOS_INLINE_FUNCTION
  bool operator != (const SuperScalar& src) {
    bool compare = true;
    for(int i=0; i<N; i++)
      compare = compare && ( val[i] == src.val[i]);
    return !compare;
  }



  KOKKOS_INLINE_FUNCTION
  SuperScalar(const double& src) {
    for(int i=0; i<N; i++)
      val[i] = 1.0 * (i+1) * src;
  }

};

template<int N>
std::ostream& operator<<(std::ostream& os, const SuperScalar<N>& dt)
{
    os << "{ ";
    for(int i=0;i<N-1;i++)
       os << dt.val[i] << ", ";
    os << dt.val[N-1] << "}";
    return os;
}

template<class T,class DEVICE_TYPE>
struct ZeroFunctor {
  typedef DEVICE_TYPE execution_space;
  typedef typename Kokkos::View<T,execution_space> type;
  typedef typename Kokkos::View<T,execution_space>::HostMirror h_type;
  type data;
  KOKKOS_INLINE_FUNCTION
  void operator()(int) const {
    data() = 0;
  }
};

//---------------------------------------------------
//--------------atomic_fetch_add---------------------
//---------------------------------------------------

template<class T,class DEVICE_TYPE>
struct AddFunctor{
  typedef DEVICE_TYPE execution_space;
  typedef Kokkos::View<T,execution_space> type;
  type data;

  KOKKOS_INLINE_FUNCTION
  void operator()(int) const {
    Kokkos::atomic_fetch_add(&data(),(T)1);
  }
};

template<class T, class execution_space >
T AddLoop(int loop) {
  struct ZeroFunctor<T,execution_space> f_zero;
  typename ZeroFunctor<T,execution_space>::type data("Data");
  typename ZeroFunctor<T,execution_space>::h_type h_data("HData");
  f_zero.data = data;
  Kokkos::parallel_for(1,f_zero);
  execution_space::fence();

  struct AddFunctor<T,execution_space> f_add;
  f_add.data = data;
  Kokkos::parallel_for(loop,f_add);
  execution_space::fence();

  Kokkos::deep_copy(h_data,data);
  T val = h_data();
  return val;
}

template<class T>
T AddLoopSerial(int loop) {
  T* data = new T[1];
  data[0] = 0;

  for(int i=0;i<loop;i++)
  *data+=(T)1;

  T val = *data;
  delete [] data;
  return val;
}

template<class T,class DEVICE_TYPE>
struct CASFunctor{
  typedef DEVICE_TYPE execution_space;
  typedef Kokkos::View<T,execution_space> type;
  type data;

  KOKKOS_INLINE_FUNCTION
  void operator()(int) const {
	  T old = data();
	  T newval, assumed;
	  do {
	    assumed = old;
	    newval = assumed + (T)1;
	    old = Kokkos::atomic_compare_exchange(&data(), assumed, newval);
	  }
	  while( old != assumed );
  }
};

template<class T, class execution_space >
T CASLoop(int loop) {
  struct ZeroFunctor<T,execution_space> f_zero;
  typename ZeroFunctor<T,execution_space>::type data("Data");
  typename ZeroFunctor<T,execution_space>::h_type h_data("HData");
  f_zero.data = data;
  Kokkos::parallel_for(1,f_zero);
  execution_space::fence();

  struct CASFunctor<T,execution_space> f_cas;
  f_cas.data = data;
  Kokkos::parallel_for(loop,f_cas);
  execution_space::fence();

  Kokkos::deep_copy(h_data,data);
  T val = h_data();

  return val;
}

template<class T>
T CASLoopSerial(int loop) {
  T* data = new T[1];
  data[0] = 0;

  for(int i=0;i<loop;i++) {
	  T assumed;
	  T newval;
	  T old;
	  do {
	    assumed = *data;
	    newval = assumed + (T)1;
	    old = *data;
	    *data = newval;
	  }
	  while(!(assumed==old));
  }

  T val = *data;
  delete [] data;
  return val;
}

template<class T,class DEVICE_TYPE>
struct ExchFunctor{
  typedef DEVICE_TYPE execution_space;
  typedef Kokkos::View<T,execution_space> type;
  type data, data2;

  KOKKOS_INLINE_FUNCTION
  void operator()(int i) const {
    T old = Kokkos::atomic_exchange(&data(),(T)i);
    Kokkos::atomic_fetch_add(&data2(),old);
  }
};

template<class T, class execution_space >
T ExchLoop(int loop) {
  struct ZeroFunctor<T,execution_space> f_zero;
  typename ZeroFunctor<T,execution_space>::type data("Data");
  typename ZeroFunctor<T,execution_space>::h_type h_data("HData");
  f_zero.data = data;
  Kokkos::parallel_for(1,f_zero);
  execution_space::fence();

  typename ZeroFunctor<T,execution_space>::type data2("Data");
  typename ZeroFunctor<T,execution_space>::h_type h_data2("HData");
  f_zero.data = data2;
  Kokkos::parallel_for(1,f_zero);
  execution_space::fence();

  struct ExchFunctor<T,execution_space> f_exch;
  f_exch.data = data;
  f_exch.data2 = data2;
  Kokkos::parallel_for(loop,f_exch);
  execution_space::fence();

  Kokkos::deep_copy(h_data,data);
  Kokkos::deep_copy(h_data2,data2);
  T val = h_data() + h_data2();

  return val;
}

template<class T>
T ExchLoopSerial(int loop) {
  T* data = new T[1];
  T* data2 = new T[1];
  data[0] = 0;
  data2[0] = 0;
  for(int i=0;i<loop;i++) {
	T old = *data;
	*data=(T) i;
	*data2+=old;
  }

  T val = *data2 + *data;
  delete [] data;
  delete [] data2;
  return val;
}

template<class T, class DeviceType >
T LoopVariant(int loop, int test) {
  switch (test) {
    case 1: return AddLoop<T,DeviceType>(loop);
    case 2: return CASLoop<T,DeviceType>(loop);
    case 3: return ExchLoop<T,DeviceType>(loop);
  }
  return 0;
}

template<class T>
T LoopVariantSerial(int loop, int test) {
  switch (test) {
    case 1: return AddLoopSerial<T>(loop);
    case 2: return CASLoopSerial<T>(loop);
    case 3: return ExchLoopSerial<T>(loop);
  }
  return 0;
}

template<class T,class DeviceType>
bool Loop(int loop, int test)
{
  T res       = LoopVariant<T,DeviceType>(loop,test);
  T resSerial = LoopVariantSerial<T>(loop,test);

  bool passed = true;

  if ( resSerial != res ) {
    passed = false;

    std::cout << "Loop<"
              << typeid(T).name()
              << ">( test = "
              << test << " FAILED : "
              << resSerial << " != " << res
              << std::endl ;
  }


  return passed ;
}

}