gather.hpp (7c9a9f7)

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#ifndef gather_hpp
#define gather_hpp

#include <functional>

#include <omp.h>
#include <ginkgo/ginkgo.hpp>

#include <collective_common.hpp>

namespace schwz {


template <typename ValueType, typename IndexType>
extern void gather_add_values(const IndexType num_elems,
                              const IndexType *indices,
                              const ValueType *from_array,
                              ValueType *into_array);

template <typename ValueType, typename IndexType>
extern void gather_diff_values(const IndexType num_elems,
                               const IndexType *indices,
                               const ValueType *from_array,
                               ValueType *into_array);

template <typename ValueType, typename IndexType>
extern void gather_avg_values(const IndexType num_elems,
                              const IndexType *indices,
                              const ValueType *from_array,
                              ValueType *into_array);

template <typename ValueType, typename IndexType>
extern void gather_values(const IndexType num_elems, const IndexType *indices,
                          const ValueType *from_array, ValueType *into_array);


template <typename ValueType, typename IndexType>
struct Gather : public gko::Operation {
    Gather(const IndexType num_elems, const IndexType *indices,
           const ValueType *from_array, ValueType *into_array,
           OperationType optype)
        : num_elems{num_elems},
          indices{indices},
          from_array{from_array},
          into_array{into_array},
          optype{optype}
    {}

    void run(std::shared_ptr<const gko::OmpExecutor>) const override
    {
        switch (optype) {
        case copy:
#pragma omp parallel for
            for (auto i = 0; i < num_elems; ++i) {
                into_array[i] = from_array[indices[i]];
            }
            break;
        case add:
#pragma omp parallel for
            for (auto i = 0; i < num_elems; ++i) {
                into_array[i] = from_array[indices[i]] + into_array[i];
            }
            break;
        case diff:
#pragma omp parallel for
            for (auto i = 0; i < num_elems; ++i) {
                into_array[i] = from_array[indices[i]] - into_array[i];
            }
            break;
        case avg:
#pragma omp parallel for
            for (auto i = 0; i < num_elems; ++i) {
                into_array[i] = (from_array[indices[i]] + into_array[i]) / 2;
            }
            break;
        default: {
            std::cout << "Undefined gather operation" << std::endl;
            break;
        }
        }
    }

    void run(std::shared_ptr<const gko::CudaExecutor>) const override
    {
        switch (optype) {
        case copy:
            gather_values(num_elems, indices, from_array, into_array);
            break;
        case add:
            gather_add_values(num_elems, indices, from_array, into_array);
            break;
        case diff:
            gather_diff_values(num_elems, indices, from_array, into_array);
            break;
        case avg:
            gather_avg_values(num_elems, indices, from_array, into_array);
            break;
        default: {
            std::cout << "Undefined gather operation" << std::endl;
            break;
        }
        }
    }
    const IndexType num_elems;
    const IndexType *indices;
    const ValueType *from_array;
    ValueType *into_array;
    OperationType optype;
};


#define INSTANTIATE_FOR_EACH_VALUE_AND_INDEX_TYPE(_macro) \
    template _macro(float, gko::int32);                   \
    template _macro(double, gko::int32);                  \
    template _macro(float, gko::int64);                   \
    template _macro(double, gko::int64);

#define DECLARE_GATHER(ValueType, IndexType) struct Gather<ValueType, IndexType>
INSTANTIATE_FOR_EACH_VALUE_AND_INDEX_TYPE(DECLARE_GATHER);
#undef DECLARE_GATHER

}  // namespace schwz


#endif  // gather.hpp