cub/block/block_histogram.cuh
File members: cub/block/block_histogram.cuh
/******************************************************************************
* Copyright (c) 2011, Duane Merrill. All rights reserved.
* Copyright (c) 2011-2018, NVIDIA CORPORATION. All rights reserved.
*
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* notice, this list of conditions and the following disclaimer.
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* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
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* names of its contributors may be used to endorse or promote products
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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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/block/specializations/block_histogram_atomic.cuh>
#include <cub/block/specializations/block_histogram_sort.cuh>
#include <cub/util_ptx.cuh>
#include <cuda/std/type_traits>
CUB_NAMESPACE_BEGIN
enum BlockHistogramAlgorithm
{
BLOCK_HISTO_SORT,
BLOCK_HISTO_ATOMIC,
};
template <typename T,
int BLOCK_DIM_X,
int ITEMS_PER_THREAD,
int BINS,
BlockHistogramAlgorithm ALGORITHM = BLOCK_HISTO_SORT,
int BLOCK_DIM_Y = 1,
int BLOCK_DIM_Z = 1,
int LEGACY_PTX_ARCH = 0>
class BlockHistogram
{
private:
enum
{
BLOCK_THREADS = BLOCK_DIM_X * BLOCK_DIM_Y * BLOCK_DIM_Z,
};
using InternalBlockHistogram =
::cuda::std::_If<ALGORITHM == BLOCK_HISTO_SORT,
BlockHistogramSort<T, BLOCK_DIM_X, ITEMS_PER_THREAD, BINS, BLOCK_DIM_Y, BLOCK_DIM_Z>,
BlockHistogramAtomic<BINS>>;
using _TempStorage = typename InternalBlockHistogram::TempStorage;
_TempStorage& temp_storage;
unsigned int linear_tid;
_CCCL_DEVICE _CCCL_FORCEINLINE _TempStorage& PrivateStorage()
{
__shared__ _TempStorage private_storage;
return private_storage;
}
public:
struct TempStorage : Uninitialized<_TempStorage>
{};
_CCCL_DEVICE _CCCL_FORCEINLINE BlockHistogram()
: temp_storage(PrivateStorage())
, linear_tid(RowMajorTid(BLOCK_DIM_X, BLOCK_DIM_Y, BLOCK_DIM_Z))
{}
_CCCL_DEVICE _CCCL_FORCEINLINE BlockHistogram(TempStorage& temp_storage)
: temp_storage(temp_storage.Alias())
, linear_tid(RowMajorTid(BLOCK_DIM_X, BLOCK_DIM_Y, BLOCK_DIM_Z))
{}
template <typename CounterT>
_CCCL_DEVICE _CCCL_FORCEINLINE void InitHistogram(CounterT histogram[BINS])
{
// Initialize histogram bin counts to zeros
int histo_offset = 0;
#pragma unroll
for (; histo_offset + BLOCK_THREADS <= BINS; histo_offset += BLOCK_THREADS)
{
histogram[histo_offset + linear_tid] = 0;
}
// Finish up with guarded initialization if necessary
if ((BINS % BLOCK_THREADS != 0) && (histo_offset + linear_tid < BINS))
{
histogram[histo_offset + linear_tid] = 0;
}
}
template <typename CounterT>
_CCCL_DEVICE _CCCL_FORCEINLINE void Histogram(T (&items)[ITEMS_PER_THREAD], CounterT histogram[BINS])
{
// Initialize histogram bin counts to zeros
InitHistogram(histogram);
CTA_SYNC();
// Composite the histogram
InternalBlockHistogram(temp_storage).Composite(items, histogram);
}
template <typename CounterT>
_CCCL_DEVICE _CCCL_FORCEINLINE void Composite(T (&items)[ITEMS_PER_THREAD], CounterT histogram[BINS])
{
InternalBlockHistogram(temp_storage).Composite(items, histogram);
}
};
CUB_NAMESPACE_END