thread_reduce.cuh

File members: /home/runner/work/cccl/cccl/cub/cub/thread/thread_reduce.cuh
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 * Copyright (c) 2011, Duane Merrill.  All rights reserved.
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#pragma once

#include <cub/config.cuh>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include <cub/detail/type_traits.cuh>
#include <cub/thread/thread_operators.cuh>

CUB_NAMESPACE_BEGIN

namespace internal
{

template <int LENGTH,
          typename T,
          typename ReductionOp,
          typename PrefixT,
          typename AccumT = detail::accumulator_t<ReductionOp, PrefixT, T>>
_CCCL_DEVICE _CCCL_FORCEINLINE AccumT
ThreadReduce(T* input, ReductionOp reduction_op, PrefixT prefix, Int2Type<LENGTH> /*length*/)
{
  AccumT retval = prefix;

#pragma unroll
  for (int i = 0; i < LENGTH; ++i)
  {
    retval = reduction_op(retval, input[i]);
  }

  return retval;
}

template <int LENGTH,
          typename T,
          typename ReductionOp,
          typename PrefixT,
          typename AccumT = detail::accumulator_t<ReductionOp, PrefixT, T>>
_CCCL_DEVICE _CCCL_FORCEINLINE AccumT ThreadReduce(T* input, ReductionOp reduction_op, PrefixT prefix)
{
  return ThreadReduce(input, reduction_op, prefix, Int2Type<LENGTH>());
}

template <int LENGTH, typename T, typename ReductionOp>
_CCCL_DEVICE _CCCL_FORCEINLINE T ThreadReduce(T* input, ReductionOp reduction_op)
{
  T prefix = input[0];
  return ThreadReduce<LENGTH - 1>(input + 1, reduction_op, prefix);
}

template <int LENGTH,
          typename T,
          typename ReductionOp,
          typename PrefixT,
          typename AccumT = detail::accumulator_t<ReductionOp, PrefixT, T>>
_CCCL_DEVICE _CCCL_FORCEINLINE AccumT ThreadReduce(T (&input)[LENGTH], ReductionOp reduction_op, PrefixT prefix)
{
  return ThreadReduce(input, reduction_op, prefix, Int2Type<LENGTH>());
}

template <int LENGTH, typename T, typename ReductionOp>
_CCCL_DEVICE _CCCL_FORCEINLINE T ThreadReduce(T (&input)[LENGTH], ReductionOp reduction_op)
{
  return ThreadReduce<LENGTH>((T*) input, reduction_op);
}

} // namespace internal
CUB_NAMESPACE_END