transform_exclusive_scan

Header File: Kokkos_StdAlgorithms.hpp

namespace Kokkos{
namespace Experimental{

template <
  class ExecutionSpace, class InputIteratorType,
  class OutputIteratorType, class ValueType,
  class BinaryOpType, class UnaryOpType>
OutputIteratorType transform_exclusive_scan(const ExecutionSpace& exespace,     (1)
                                            InputIteratorType first_from,
                                            InputIteratorType last_from,
                                            OutputIteratorType first_dest,
                                            ValueType init_value,
                                            BinaryOpType binary_op,
                                            UnaryOpType unary_op);

template <
  class ExecutionSpace, class InputIteratorType,
  class OutputIteratorType, class ValueType,
  class BinaryOpType, class UnaryOpType>
OutputIteratorType transform_exclusive_scan(const std::string& label,           (2)
                                            const ExecutionSpace& exespace,
                                            InputIteratorType first_from,
                                            InputIteratorType last_from,
                                            OutputIteratorType first_dest,
                                            ValueType init_value,
                                            BinaryOpType binary_op,
                                            UnaryOpType unary_op);

template <
  class ExecutionSpace,
  class DataType1, class... Properties1,
  class DataType2, class... Properties2,
  class ValueType, class BinaryOpType, class UnaryOpType>
auto transform_exclusive_scan(const ExecutionSpace& exespace,                   (3)
                              const ::Kokkos::View<DataType1, Properties1...>& view_from,
                              const ::Kokkos::View<DataType2, Properties2...>& view_dest,
                              ValueType init_value, BinaryOpType binary_op,
                              UnaryOpType unary_op);

template <
  class ExecutionSpace,
  class DataType1, class... Properties1,
  class DataType2, class... Properties2,
  class ValueType, class BinaryOpType, class UnaryOpType>
auto transform_exclusive_scan(const std::string& label,                         (4)
                              const ExecutionSpace& exespace,
                              const ::Kokkos::View<DataType1, Properties1...>& view_from,
                              const ::Kokkos::View<DataType2, Properties2...>& view_dest,
                              ValueType init_value, BinaryOpType binary_op,
                              UnaryOpType unary_op);

} //end namespace Experimental
} //end namespace Kokkos

Description

• 1,2: transforms each element in the range [first_from, last_from) with unary_op, then computes an exclusive prefix scan operation using binary_op over the resulting range, with init as the initial value, and writes the results to the range beginning at first_dest. “exclusive” means that the i-th input element is not included in the i-th sum

• 3,4: same as (1,2) except that the elements are read from view_from and written to view_dest

Parameters and Requirements

• exespace, first_from, first_last, first_dest, view_from, view_dest:

  • same as exclusive_scan

• label:

  • used to name the implementation kernels for debugging purposes

  • for 1 the default string is: “Kokkos::transform_exclusive_scan_iterator_api_default”

  • for 3 the default string is: “Kokkos::transform_exclusive_scan_view_api_default”

• unary_op:

  • unary functor performing the desired transformation operation to an element. Must be valid to be called from the execution space passed, and callable with an arguments v of type (possible const) value_type, where value_type is the value type of first_from (for 1,2) or the value type of view_from (for 3,4), and must not modify v.

  • Must conform to:

  struct UnaryOp {
    KOKKOS_FUNCTION
    constexpr value_type operator()(const value_type & v) const {
      return /* ... */
    }
  };
  

Return

Iterator to the element after the last element written.