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/**
 * \file
 * The cub::BlockHistogramAtomic class provides atomic-based methods for constructing block-wide histograms from data samples partitioned across a CUDA thread block.
 */

#pragma once

#include "../../util_namespace.cuh"

/// Optional outer namespace(s)
CUB_NS_PREFIX

/// CUB namespace
namespace cub {


/**
 * \brief The BlockHistogramAtomic class provides atomic-based methods for constructing block-wide histograms from data samples partitioned across a CUDA thread block.
 */
template <int BINS>
struct BlockHistogramAtomic
{
    /// Shared memory storage layout type
    struct TempStorage {};


    /// Constructor
    __device__ __forceinline__ BlockHistogramAtomic(
        TempStorage &temp_storage)
    {}


    /// Composite data onto an existing histogram
    template <
        typename            T,
        typename            HistoCounter,
        int                 ITEMS_PER_THREAD>
    __device__ __forceinline__ void Composite(
        T                   (&items)[ITEMS_PER_THREAD],     ///< [in] Calling thread's input values to histogram
        HistoCounter        histogram[BINS])                 ///< [out] Reference to shared/global memory histogram
    {
        // Update histogram
        #pragma unroll
        for (int i = 0; i < ITEMS_PER_THREAD; ++i)
        {
              atomicAdd(histogram + items[i], 1);
        }
    }

};

}               // CUB namespace
CUB_NS_POSTFIX  // Optional outer namespace(s)

