Kokkos::Sum

`Kokkos::Sum`

Specific implementation of ReducerConcept performing an add operation

Header File: Kokkos_Core.hpp

Usage:

T result;
parallel_reduce(N,Functor,Sum<T,S>(result));

.

Synopsis

template<class Scalar, class Space>
class Sum{
  public:
    typedef Sum reducer;
    typedef typename std::remove_cv<Scalar>::type value_type;
    typedef Kokkos::View<value_type, Space> result_view_type;
    
    KOKKOS_INLINE_FUNCTION
    void join(value_type& dest, const value_type& src)  const

    KOKKOS_INLINE_FUNCTION
    void join(volatile value_type& dest, const volatile value_type& src) const;

    KOKKOS_INLINE_FUNCTION
    void init( value_type& val)  const;

    KOKKOS_INLINE_FUNCTION
    value_type& reference() const;

    KOKKOS_INLINE_FUNCTION
    result_view_type view() const;

    KOKKOS_INLINE_FUNCTION
    Sum(value_type& value_);

    KOKKOS_INLINE_FUNCTION
    Sum(const result_view_type& value_);
};

Public Class Members

Typedefs

reducer: The self type.
value_type: The reduction scalar type.
result_view_type: A Kokkos::View referencing the reduction result

Constructors

```
Sum(value_type& result)
```
Constructs a reducer which references a local variable as its result location.
```
Sum(const result_view_type result)`
```
Constructs a reducer which references a specific view as its result location.

Functions

void join(value_type& dest, const value_type& src)  const;`

Add src into dest: dest+=src;.

void join(volatile value_type& dest, const volatile value_type& src) const;

Add src into dest: dest+=src;.

```
void init( value_type& val)  const;
```
Initialize val using the Kokkos::reduction_identity::sum() method. The default implementation sets val=0.
```
value_type& reference() const;
```
Returns a reference to the result provided in class constructor.
```
result_view_type view() const;
```
Returns a view of the result place provided in class constructor.

Additional Information

Sum<T,S>::value_type is non-const T
Sum<T,S>::result_view_type is Kokkos::View<T,S,Kokkos::MemoryTraits<Kokkos::Unmanaged>>. Note that the S (memory space) must be the same as the space where the result resides.
Requires: Scalar has operator = and operator += defined. Kokkos::reduction_identity<Scalar>::sum() is a valid expression.
In order to use Sum with a custom type, a template specialization of Kokkos::reduction_identity must be defined. See Using Built-in Reducers with Custom Scalar Types for details