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tools/cub-1.8.0/cub/device/dispatch/dispatch_histogram.cuh 55.9 KB
8dcb6dfcb   Yannick Estève   first commit
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  /******************************************************************************
   * Copyright (c) 2011, Duane Merrill.  All rights reserved.
   * Copyright (c) 2011-2018, NVIDIA CORPORATION.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of the NVIDIA CORPORATION nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   * 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
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   ******************************************************************************/
  
  /**
   * \file
   * cub::DeviceHistogram provides device-wide parallel operations for constructing histogram(s) from a sequence of samples data residing within device-accessible memory.
   */
  
  #pragma once
  
  #include <stdio.h>
  #include <iterator>
  #include <limits>
  
  #include "../../agent/agent_histogram.cuh"
  #include "../../util_debug.cuh"
  #include "../../util_device.cuh"
  #include "../../thread/thread_search.cuh"
  #include "../../grid/grid_queue.cuh"
  #include "../../util_namespace.cuh"
  
  /// Optional outer namespace(s)
  CUB_NS_PREFIX
  
  /// CUB namespace
  namespace cub {
  
  
  
  /******************************************************************************
   * Histogram kernel entry points
   *****************************************************************************/
  
  /**
   * Histogram initialization kernel entry point
   */
  template <
      int                                             NUM_ACTIVE_CHANNELS,            ///< Number of channels actively being histogrammed
      typename                                        CounterT,                       ///< Integer type for counting sample occurrences per histogram bin
      typename                                        OffsetT>                        ///< Signed integer type for global offsets
  __global__ void DeviceHistogramInitKernel(
      ArrayWrapper<int, NUM_ACTIVE_CHANNELS>          num_output_bins_wrapper,        ///< Number of output histogram bins per channel
      ArrayWrapper<CounterT*, NUM_ACTIVE_CHANNELS>    d_output_histograms_wrapper,    ///< Histogram counter data having logical dimensions <tt>CounterT[NUM_ACTIVE_CHANNELS][num_bins.array[CHANNEL]]</tt>
      GridQueue<int>                                  tile_queue)                     ///< Drain queue descriptor for dynamically mapping tile data onto thread blocks
  {
      if ((threadIdx.x == 0) && (blockIdx.x == 0))
          tile_queue.ResetDrain();
  
      int output_bin = (blockIdx.x * blockDim.x) + threadIdx.x;
  
      #pragma unroll
      for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
      {
          if (output_bin < num_output_bins_wrapper.array[CHANNEL])
              d_output_histograms_wrapper.array[CHANNEL][output_bin] = 0;
      }
  }
  
  
  /**
   * Histogram privatized sweep kernel entry point (multi-block).  Computes privatized histograms, one per thread block.
   */
  template <
      typename                                            AgentHistogramPolicyT,     ///< Parameterized AgentHistogramPolicy tuning policy type
      int                                                 PRIVATIZED_SMEM_BINS,           ///< Maximum number of histogram bins per channel (e.g., up to 256)
      int                                                 NUM_CHANNELS,                   ///< Number of channels interleaved in the input data (may be greater than the number of channels being actively histogrammed)
      int                                                 NUM_ACTIVE_CHANNELS,            ///< Number of channels actively being histogrammed
      typename                                            SampleIteratorT,                ///< The input iterator type. \iterator.
      typename                                            CounterT,                       ///< Integer type for counting sample occurrences per histogram bin
      typename                                            PrivatizedDecodeOpT,            ///< The transform operator type for determining privatized counter indices from samples, one for each channel
      typename                                            OutputDecodeOpT,                ///< The transform operator type for determining output bin-ids from privatized counter indices, one for each channel
      typename                                            OffsetT>                        ///< Signed integer type for global offsets
  __launch_bounds__ (int(AgentHistogramPolicyT::BLOCK_THREADS))
  __global__ void DeviceHistogramSweepKernel(
      SampleIteratorT                                         d_samples,                          ///< Input data to reduce
      ArrayWrapper<int, NUM_ACTIVE_CHANNELS>                  num_output_bins_wrapper,            ///< The number bins per final output histogram
      ArrayWrapper<int, NUM_ACTIVE_CHANNELS>                  num_privatized_bins_wrapper,        ///< The number bins per privatized histogram
      ArrayWrapper<CounterT*, NUM_ACTIVE_CHANNELS>            d_output_histograms_wrapper,        ///< Reference to final output histograms
      ArrayWrapper<CounterT*, NUM_ACTIVE_CHANNELS>            d_privatized_histograms_wrapper,    ///< Reference to privatized histograms
      ArrayWrapper<OutputDecodeOpT, NUM_ACTIVE_CHANNELS>      output_decode_op_wrapper,           ///< The transform operator for determining output bin-ids from privatized counter indices, one for each channel
      ArrayWrapper<PrivatizedDecodeOpT, NUM_ACTIVE_CHANNELS>  privatized_decode_op_wrapper,       ///< The transform operator for determining privatized counter indices from samples, one for each channel
      OffsetT                                                 num_row_pixels,                     ///< The number of multi-channel pixels per row in the region of interest
      OffsetT                                                 num_rows,                           ///< The number of rows in the region of interest
      OffsetT                                                 row_stride_samples,                 ///< The number of samples between starts of consecutive rows in the region of interest
      int                                                     tiles_per_row,                      ///< Number of image tiles per row
      GridQueue<int>                                          tile_queue)                         ///< Drain queue descriptor for dynamically mapping tile data onto thread blocks
  {
      // Thread block type for compositing input tiles
      typedef AgentHistogram<
              AgentHistogramPolicyT,
              PRIVATIZED_SMEM_BINS,
              NUM_CHANNELS,
              NUM_ACTIVE_CHANNELS,
              SampleIteratorT,
              CounterT,
              PrivatizedDecodeOpT,
              OutputDecodeOpT,
              OffsetT>
          AgentHistogramT;
  
      // Shared memory for AgentHistogram
      __shared__ typename AgentHistogramT::TempStorage temp_storage;
  
      AgentHistogramT agent(
          temp_storage,
          d_samples,
          num_output_bins_wrapper.array,
          num_privatized_bins_wrapper.array,
          d_output_histograms_wrapper.array,
          d_privatized_histograms_wrapper.array,
          output_decode_op_wrapper.array,
          privatized_decode_op_wrapper.array);
  
      // Initialize counters
      agent.InitBinCounters();
  
      // Consume input tiles
      agent.ConsumeTiles(
          num_row_pixels,
          num_rows,
          row_stride_samples,
          tiles_per_row,
          tile_queue);
  
      // Store output to global (if necessary)
      agent.StoreOutput();
  
  }
  
  
  
  
  
  
  /******************************************************************************
   * Dispatch
   ******************************************************************************/
  
  /**
   * Utility class for dispatching the appropriately-tuned kernels for DeviceHistogram
   */
  template <
      int         NUM_CHANNELS,               ///< Number of channels interleaved in the input data (may be greater than the number of channels being actively histogrammed)
      int         NUM_ACTIVE_CHANNELS,        ///< Number of channels actively being histogrammed
      typename    SampleIteratorT,            ///< Random-access input iterator type for reading input items \iterator
      typename    CounterT,                   ///< Integer type for counting sample occurrences per histogram bin
      typename    LevelT,                     ///< Type for specifying bin level boundaries
      typename    OffsetT>                    ///< Signed integer type for global offsets
  struct DipatchHistogram
  {
      //---------------------------------------------------------------------
      // Types and constants
      //---------------------------------------------------------------------
  
      /// The sample value type of the input iterator
      typedef typename std::iterator_traits<SampleIteratorT>::value_type SampleT;
  
      enum
      {
          // Maximum number of bins per channel for which we will use a privatized smem strategy
          MAX_PRIVATIZED_SMEM_BINS = 256
      };
  
  
      //---------------------------------------------------------------------
      // Transform functors for converting samples to bin-ids
      //---------------------------------------------------------------------
  
      // Searches for bin given a list of bin-boundary levels
      template <typename LevelIteratorT>
      struct SearchTransform
      {
          LevelIteratorT  d_levels;                   // Pointer to levels array
          int             num_output_levels;          // Number of levels in array
  
          // Initializer
          __host__ __device__ __forceinline__ void Init(
              LevelIteratorT  d_levels,               // Pointer to levels array
              int             num_output_levels)      // Number of levels in array
          {
              this->d_levels          = d_levels;
              this->num_output_levels = num_output_levels;
          }
  
          // Method for converting samples to bin-ids
          template <CacheLoadModifier LOAD_MODIFIER, typename _SampleT>
          __host__ __device__ __forceinline__ void BinSelect(_SampleT sample, int &bin, bool valid)
          {
              /// Level iterator wrapper type
              typedef typename If<IsPointer<LevelIteratorT>::VALUE,
                      CacheModifiedInputIterator<LOAD_MODIFIER, LevelT, OffsetT>,     // Wrap the native input pointer with CacheModifiedInputIterator
                      LevelIteratorT>::Type                                           // Directly use the supplied input iterator type
                  WrappedLevelIteratorT;
  
              WrappedLevelIteratorT wrapped_levels(d_levels);
  
              int num_bins = num_output_levels - 1;
              if (valid)
              {
                  bin = UpperBound(wrapped_levels, num_output_levels, (LevelT) sample) - 1;
                  if (bin >= num_bins)
                      bin = -1;
              }
          }
      };
  
  
      // Scales samples to evenly-spaced bins
      struct ScaleTransform
      {
          int    num_bins;    // Number of levels in array
          LevelT max;         // Max sample level (exclusive)
          LevelT min;         // Min sample level (inclusive)
          LevelT scale;       // Bin scaling factor
  
          // Initializer
          template <typename _LevelT>
          __host__ __device__ __forceinline__ void Init(
              int     num_output_levels,  // Number of levels in array
              _LevelT max,                // Max sample level (exclusive)
              _LevelT min,                // Min sample level (inclusive)
              _LevelT scale)              // Bin scaling factor
          {
              this->num_bins = num_output_levels - 1;
              this->max = max;
              this->min = min;
              this->scale = scale;
          }
  
          // Initializer (float specialization)
          __host__ __device__ __forceinline__ void Init(
              int    num_output_levels,   // Number of levels in array
              float   max,                // Max sample level (exclusive)
              float   min,                // Min sample level (inclusive)
              float   scale)              // Bin scaling factor
          {
              this->num_bins = num_output_levels - 1;
              this->max = max;
              this->min = min;
              this->scale = float(1.0) / scale;
          }
  
          // Initializer (double specialization)
          __host__ __device__ __forceinline__ void Init(
              int    num_output_levels,   // Number of levels in array
              double max,                 // Max sample level (exclusive)
              double min,                 // Min sample level (inclusive)
              double scale)               // Bin scaling factor
          {
              this->num_bins = num_output_levels - 1;
              this->max = max;
              this->min = min;
              this->scale = double(1.0) / scale;
          }
  
          // Method for converting samples to bin-ids
          template <CacheLoadModifier LOAD_MODIFIER, typename _SampleT>
          __host__ __device__ __forceinline__ void BinSelect(_SampleT sample, int &bin, bool valid)
          {
              LevelT level_sample = (LevelT) sample;
  
              if (valid && (level_sample >= min) && (level_sample < max))
                  bin = (int) ((level_sample - min) / scale);
          }
  
          // Method for converting samples to bin-ids (float specialization)
          template <CacheLoadModifier LOAD_MODIFIER>
          __host__ __device__ __forceinline__ void BinSelect(float sample, int &bin, bool valid)
          {
              LevelT level_sample = (LevelT) sample;
  
              if (valid && (level_sample >= min) && (level_sample < max))
                  bin = (int) ((level_sample - min) * scale);
          }
  
          // Method for converting samples to bin-ids (double specialization)
          template <CacheLoadModifier LOAD_MODIFIER>
          __host__ __device__ __forceinline__ void BinSelect(double sample, int &bin, bool valid)
          {
              LevelT level_sample = (LevelT) sample;
  
              if (valid && (level_sample >= min) && (level_sample < max))
                  bin = (int) ((level_sample - min) * scale);
          }
      };
  
  
      // Pass-through bin transform operator
      struct PassThruTransform
      {
          // Method for converting samples to bin-ids
          template <CacheLoadModifier LOAD_MODIFIER, typename _SampleT>
          __host__ __device__ __forceinline__ void BinSelect(_SampleT sample, int &bin, bool valid)
          {
              if (valid)
                  bin = (int) sample;
          }
      };
  
  
  
      //---------------------------------------------------------------------
      // Tuning policies
      //---------------------------------------------------------------------
  
      template <int NOMINAL_ITEMS_PER_THREAD>
      struct TScale
      {
          enum
          {
              V_SCALE = (sizeof(SampleT) + sizeof(int) - 1) / sizeof(int),
              VALUE   = CUB_MAX((NOMINAL_ITEMS_PER_THREAD / NUM_ACTIVE_CHANNELS / V_SCALE), 1)
          };
      };
  
  
      /// SM11
      struct Policy110
      {
          // HistogramSweepPolicy
          typedef AgentHistogramPolicy<
                  512,
                  (NUM_CHANNELS == 1) ? 8 : 2,
                  BLOCK_LOAD_DIRECT,
                  LOAD_DEFAULT,
                  true,
                  GMEM,
                  false>
              HistogramSweepPolicy;
      };
  
      /// SM20
      struct Policy200
      {
          // HistogramSweepPolicy
          typedef AgentHistogramPolicy<
                  (NUM_CHANNELS == 1) ? 256 : 128,
                  (NUM_CHANNELS == 1) ? 8 : 3,
                  (NUM_CHANNELS == 1) ? BLOCK_LOAD_DIRECT : BLOCK_LOAD_WARP_TRANSPOSE,
                  LOAD_DEFAULT,
                  true,
                  SMEM,
                  false>
              HistogramSweepPolicy;
      };
  
      /// SM30
      struct Policy300
      {
          // HistogramSweepPolicy
          typedef AgentHistogramPolicy<
                  512,
                  (NUM_CHANNELS == 1) ? 8 : 2,
                  BLOCK_LOAD_DIRECT,
                  LOAD_DEFAULT,
                  true,
                  GMEM,
                  false>
              HistogramSweepPolicy;
      };
  
      /// SM35
      struct Policy350
      {
          // HistogramSweepPolicy
          typedef AgentHistogramPolicy<
                  128,
                  TScale<8>::VALUE,
                  BLOCK_LOAD_DIRECT,
                  LOAD_LDG,
                  true,
                  BLEND,
                  true>
              HistogramSweepPolicy;
      };
  
      /// SM50
      struct Policy500
      {
          // HistogramSweepPolicy
          typedef AgentHistogramPolicy<
                  384,
                  TScale<16>::VALUE,
                  BLOCK_LOAD_DIRECT,
                  LOAD_LDG,
                  true,
                  SMEM,
                  false>
              HistogramSweepPolicy;
      };
  
  
  
      //---------------------------------------------------------------------
      // Tuning policies of current PTX compiler pass
      //---------------------------------------------------------------------
  
  #if (CUB_PTX_ARCH >= 500)
      typedef Policy500 PtxPolicy;
  
  #elif (CUB_PTX_ARCH >= 350)
      typedef Policy350 PtxPolicy;
  
  #elif (CUB_PTX_ARCH >= 300)
      typedef Policy300 PtxPolicy;
  
  #elif (CUB_PTX_ARCH >= 200)
      typedef Policy200 PtxPolicy;
  
  #else
      typedef Policy110 PtxPolicy;
  
  #endif
  
      // "Opaque" policies (whose parameterizations aren't reflected in the type signature)
      struct PtxHistogramSweepPolicy : PtxPolicy::HistogramSweepPolicy {};
  
  
      //---------------------------------------------------------------------
      // Utilities
      //---------------------------------------------------------------------
  
      /**
       * Initialize kernel dispatch configurations with the policies corresponding to the PTX assembly we will use
       */
      template <typename KernelConfig>
      CUB_RUNTIME_FUNCTION __forceinline__
      static cudaError_t InitConfigs(
          int             ptx_version,
          KernelConfig    &histogram_sweep_config)
      {
      #if (CUB_PTX_ARCH > 0)
  
          // We're on the device, so initialize the kernel dispatch configurations with the current PTX policy
          return histogram_sweep_config.template Init<PtxHistogramSweepPolicy>();
  
      #else
  
          // We're on the host, so lookup and initialize the kernel dispatch configurations with the policies that match the device's PTX version
          if (ptx_version >= 500)
          {
              return histogram_sweep_config.template Init<typename Policy500::HistogramSweepPolicy>();
          }
          else if (ptx_version >= 350)
          {
              return histogram_sweep_config.template Init<typename Policy350::HistogramSweepPolicy>();
          }
          else if (ptx_version >= 300)
          {
              return histogram_sweep_config.template Init<typename Policy300::HistogramSweepPolicy>();
          }
          else if (ptx_version >= 200)
          {
              return histogram_sweep_config.template Init<typename Policy200::HistogramSweepPolicy>();
          }
          else if (ptx_version >= 110)
          {
              return histogram_sweep_config.template Init<typename Policy110::HistogramSweepPolicy>();
          }
          else
          {
              // No global atomic support
              return cudaErrorNotSupported;
          }
  
      #endif
      }
  
  
      /**
       * Kernel kernel dispatch configuration
       */
      struct KernelConfig
      {
          int                             block_threads;
          int                             pixels_per_thread;
  
          template <typename BlockPolicy>
          CUB_RUNTIME_FUNCTION __forceinline__
          cudaError_t Init()
          {
              block_threads               = BlockPolicy::BLOCK_THREADS;
              pixels_per_thread           = BlockPolicy::PIXELS_PER_THREAD;
  
              return cudaSuccess;
          }
      };
  
  
      //---------------------------------------------------------------------
      // Dispatch entrypoints
      //---------------------------------------------------------------------
  
      /**
       * Privatization-based dispatch routine
       */
      template <
          typename                            PrivatizedDecodeOpT,                            ///< The transform operator type for determining privatized counter indices from samples, one for each channel
          typename                            OutputDecodeOpT,                                ///< The transform operator type for determining output bin-ids from privatized counter indices, one for each channel
          typename                            DeviceHistogramInitKernelT,                     ///< Function type of cub::DeviceHistogramInitKernel
          typename                            DeviceHistogramSweepKernelT>                    ///< Function type of cub::DeviceHistogramSweepKernel
      CUB_RUNTIME_FUNCTION __forceinline__
      static cudaError_t PrivatizedDispatch(
          void*                               d_temp_storage,                                 ///< [in] %Device-accessible allocation of temporary storage.  When NULL, the required allocation size is written to \p temp_storage_bytes and no work is done.
          size_t&                             temp_storage_bytes,                             ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
          SampleIteratorT                     d_samples,                                      ///< [in] The pointer to the input sequence of sample items. The samples from different channels are assumed to be interleaved (e.g., an array of 32-bit pixels where each pixel consists of four RGBA 8-bit samples).
          CounterT*                           d_output_histograms[NUM_ACTIVE_CHANNELS],       ///< [out] The pointers to the histogram counter output arrays, one for each active channel.  For channel<sub><em>i</em></sub>, the allocation length of <tt>d_histograms[i]</tt> should be <tt>num_output_levels[i]</tt> - 1.
          int                                 num_privatized_levels[NUM_ACTIVE_CHANNELS],     ///< [in] The number of bin level boundaries for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          PrivatizedDecodeOpT                 privatized_decode_op[NUM_ACTIVE_CHANNELS],      ///< [in] Transform operators for determining bin-ids from samples, one for each channel
          int                                 num_output_levels[NUM_ACTIVE_CHANNELS],         ///< [in] The number of bin level boundaries for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          OutputDecodeOpT                     output_decode_op[NUM_ACTIVE_CHANNELS],          ///< [in] Transform operators for determining bin-ids from samples, one for each channel
          int                                 max_num_output_bins,                            ///< [in] Maximum number of output bins in any channel
          OffsetT                             num_row_pixels,                                 ///< [in] The number of multi-channel pixels per row in the region of interest
          OffsetT                             num_rows,                                       ///< [in] The number of rows in the region of interest
          OffsetT                             row_stride_samples,                             ///< [in] The number of samples between starts of consecutive rows in the region of interest
          DeviceHistogramInitKernelT          histogram_init_kernel,                          ///< [in] Kernel function pointer to parameterization of cub::DeviceHistogramInitKernel
          DeviceHistogramSweepKernelT         histogram_sweep_kernel,                         ///< [in] Kernel function pointer to parameterization of cub::DeviceHistogramSweepKernel
          KernelConfig                        histogram_sweep_config,                         ///< [in] Dispatch parameters that match the policy that \p histogram_sweep_kernel was compiled for
          cudaStream_t                        stream,                                         ///< [in] CUDA stream to launch kernels within.  Default is stream<sub>0</sub>.
          bool                                debug_synchronous)                              ///< [in] Whether or not to synchronize the stream after every kernel launch to check for errors.  May cause significant slowdown.  Default is \p false.
      {
      #ifndef CUB_RUNTIME_ENABLED
  
          // Kernel launch not supported from this device
          return CubDebug(cudaErrorNotSupported);
  
      #else
  
          cudaError error = cudaSuccess;
          do
          {
              // Get device ordinal
              int device_ordinal;
              if (CubDebug(error = cudaGetDevice(&device_ordinal))) break;
  
              // Get SM count
              int sm_count;
              if (CubDebug(error = cudaDeviceGetAttribute (&sm_count, cudaDevAttrMultiProcessorCount, device_ordinal))) break;
  
              // Get SM occupancy for histogram_sweep_kernel
              int histogram_sweep_sm_occupancy;
              if (CubDebug(error = MaxSmOccupancy(
                  histogram_sweep_sm_occupancy,
                  histogram_sweep_kernel,
                  histogram_sweep_config.block_threads))) break;
  
              // Get device occupancy for histogram_sweep_kernel
              int histogram_sweep_occupancy = histogram_sweep_sm_occupancy * sm_count;
  
              if (num_row_pixels * NUM_CHANNELS == row_stride_samples)
              {
                  // Treat as a single linear array of samples
                  num_row_pixels      *= num_rows;
                  num_rows            = 1;
                  row_stride_samples  = num_row_pixels * NUM_CHANNELS;
              }
  
              // Get grid dimensions, trying to keep total blocks ~histogram_sweep_occupancy
              int pixels_per_tile     = histogram_sweep_config.block_threads * histogram_sweep_config.pixels_per_thread;
              int tiles_per_row       = int(num_row_pixels + pixels_per_tile - 1) / pixels_per_tile;
              int blocks_per_row      = CUB_MIN(histogram_sweep_occupancy, tiles_per_row);
              int blocks_per_col      = (blocks_per_row > 0) ?
                                          int(CUB_MIN(histogram_sweep_occupancy / blocks_per_row, num_rows)) :
                                          0;
              int num_thread_blocks   = blocks_per_row * blocks_per_col;
  
              dim3 sweep_grid_dims;
              sweep_grid_dims.x = (unsigned int) blocks_per_row;
              sweep_grid_dims.y = (unsigned int) blocks_per_col;
              sweep_grid_dims.z = 1;
  
              // Temporary storage allocation requirements
              const int   NUM_ALLOCATIONS = NUM_ACTIVE_CHANNELS + 1;
              void*       allocations[NUM_ALLOCATIONS];
              size_t      allocation_sizes[NUM_ALLOCATIONS];
  
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  allocation_sizes[CHANNEL] = size_t(num_thread_blocks) * (num_privatized_levels[CHANNEL] - 1) * sizeof(CounterT);
  
              allocation_sizes[NUM_ALLOCATIONS - 1] = GridQueue<int>::AllocationSize();
  
              // Alias the temporary allocations from the single storage blob (or compute the necessary size of the blob)
              if (CubDebug(error = AliasTemporaries(d_temp_storage, temp_storage_bytes, allocations, allocation_sizes))) break;
              if (d_temp_storage == NULL)
              {
                  // Return if the caller is simply requesting the size of the storage allocation
                  break;
              }
  
              // Construct the grid queue descriptor
              GridQueue<int> tile_queue(allocations[NUM_ALLOCATIONS - 1]);
  
              // Setup array wrapper for histogram channel output (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<CounterT*, NUM_ACTIVE_CHANNELS> d_output_histograms_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  d_output_histograms_wrapper.array[CHANNEL] = d_output_histograms[CHANNEL];
  
              // Setup array wrapper for privatized per-block histogram channel output (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<CounterT*, NUM_ACTIVE_CHANNELS> d_privatized_histograms_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  d_privatized_histograms_wrapper.array[CHANNEL] = (CounterT*) allocations[CHANNEL];
  
              // Setup array wrapper for sweep bin transforms (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<PrivatizedDecodeOpT, NUM_ACTIVE_CHANNELS> privatized_decode_op_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  privatized_decode_op_wrapper.array[CHANNEL] = privatized_decode_op[CHANNEL];
  
              // Setup array wrapper for aggregation bin transforms (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<OutputDecodeOpT, NUM_ACTIVE_CHANNELS> output_decode_op_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  output_decode_op_wrapper.array[CHANNEL] = output_decode_op[CHANNEL];
  
              // Setup array wrapper for num privatized bins (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<int, NUM_ACTIVE_CHANNELS> num_privatized_bins_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  num_privatized_bins_wrapper.array[CHANNEL] = num_privatized_levels[CHANNEL] - 1;
  
              // Setup array wrapper for num output bins (because we can't pass static arrays as kernel parameters)
              ArrayWrapper<int, NUM_ACTIVE_CHANNELS> num_output_bins_wrapper;
              for (int CHANNEL = 0; CHANNEL < NUM_ACTIVE_CHANNELS; ++CHANNEL)
                  num_output_bins_wrapper.array[CHANNEL] = num_output_levels[CHANNEL] - 1;
  
              int histogram_init_block_threads    = 256;
              int histogram_init_grid_dims        = (max_num_output_bins + histogram_init_block_threads - 1) / histogram_init_block_threads;
  
              // Log DeviceHistogramInitKernel configuration
              if (debug_synchronous) _CubLog("Invoking DeviceHistogramInitKernel<<<%d, %d, 0, %lld>>>()
  ",
                  histogram_init_grid_dims, histogram_init_block_threads, (long long) stream);
  
              // Invoke histogram_init_kernel
              histogram_init_kernel<<<histogram_init_grid_dims, histogram_init_block_threads, 0, stream>>>(
                  num_output_bins_wrapper,
                  d_output_histograms_wrapper,
                  tile_queue);
  
              // Return if empty problem
              if ((blocks_per_row == 0) || (blocks_per_col == 0))
                  break;
  
              // Log histogram_sweep_kernel configuration
              if (debug_synchronous) _CubLog("Invoking histogram_sweep_kernel<<<{%d, %d, %d}, %d, 0, %lld>>>(), %d pixels per thread, %d SM occupancy
  ",
                  sweep_grid_dims.x, sweep_grid_dims.y, sweep_grid_dims.z,
                  histogram_sweep_config.block_threads, (long long) stream, histogram_sweep_config.pixels_per_thread, histogram_sweep_sm_occupancy);
  
              // Invoke histogram_sweep_kernel
              histogram_sweep_kernel<<<sweep_grid_dims, histogram_sweep_config.block_threads, 0, stream>>>(
                  d_samples,
                  num_output_bins_wrapper,
                  num_privatized_bins_wrapper,
                  d_output_histograms_wrapper,
                  d_privatized_histograms_wrapper,
                  output_decode_op_wrapper,
                  privatized_decode_op_wrapper,
                  num_row_pixels,
                  num_rows,
                  row_stride_samples,
                  tiles_per_row,
                  tile_queue);
  
              // Check for failure to launch
              if (CubDebug(error = cudaPeekAtLastError())) break;
  
              // Sync the stream if specified to flush runtime errors
              if (debug_synchronous && (CubDebug(error = SyncStream(stream)))) break;
  
          }
          while (0);
  
          return error;
  
      #endif // CUB_RUNTIME_ENABLED
      }
  
  
  
      /**
       * Dispatch routine for HistogramRange, specialized for sample types larger than 8bit
       */
      CUB_RUNTIME_FUNCTION
      static cudaError_t DispatchRange(
          void*               d_temp_storage,                                ///< [in] %Device-accessible allocation of temporary storage.  When NULL, the required allocation size is written to \p temp_storage_bytes and no work is done.
          size_t&             temp_storage_bytes,                            ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
          SampleIteratorT     d_samples,                                  ///< [in] The pointer to the multi-channel input sequence of data samples. The samples from different channels are assumed to be interleaved (e.g., an array of 32-bit pixels where each pixel consists of four RGBA 8-bit samples).
          CounterT*           d_output_histograms[NUM_ACTIVE_CHANNELS],      ///< [out] The pointers to the histogram counter output arrays, one for each active channel.  For channel<sub><em>i</em></sub>, the allocation length of <tt>d_histograms[i]</tt> should be <tt>num_output_levels[i]</tt> - 1.
          int                 num_output_levels[NUM_ACTIVE_CHANNELS],     ///< [in] The number of boundaries (levels) for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          LevelT              *d_levels[NUM_ACTIVE_CHANNELS],             ///< [in] The pointers to the arrays of boundaries (levels), one for each active channel.  Bin ranges are defined by consecutive boundary pairings: lower sample value boundaries are inclusive and upper sample value boundaries are exclusive.
          OffsetT             num_row_pixels,                             ///< [in] The number of multi-channel pixels per row in the region of interest
          OffsetT             num_rows,                                   ///< [in] The number of rows in the region of interest
          OffsetT             row_stride_samples,                         ///< [in] The number of samples between starts of consecutive rows in the region of interest
          cudaStream_t        stream,                                     ///< [in] CUDA stream to launch kernels within.  Default is stream<sub>0</sub>.
          bool                debug_synchronous,                          ///< [in] Whether or not to synchronize the stream after every kernel launch to check for errors.  May cause significant slowdown.  Default is \p false.
          Int2Type<false>     is_byte_sample)                             ///< [in] Marker type indicating whether or not SampleT is a 8b type
      {
          cudaError error = cudaSuccess;
          do
          {
              // Get PTX version
              int ptx_version;
      #if (CUB_PTX_ARCH == 0)
              if (CubDebug(error = PtxVersion(ptx_version))) break;
      #else
              ptx_version = CUB_PTX_ARCH;
      #endif
  
              // Get kernel dispatch configurations
              KernelConfig histogram_sweep_config;
              if (CubDebug(error = InitConfigs(ptx_version, histogram_sweep_config)))
                  break;
  
              // Use the search transform op for converting samples to privatized bins
              typedef SearchTransform<LevelT*> PrivatizedDecodeOpT;
  
              // Use the pass-thru transform op for converting privatized bins to output bins
              typedef PassThruTransform OutputDecodeOpT;
  
              PrivatizedDecodeOpT     privatized_decode_op[NUM_ACTIVE_CHANNELS];
              OutputDecodeOpT         output_decode_op[NUM_ACTIVE_CHANNELS];
              int                     max_levels = num_output_levels[0];
  
              for (int channel = 0; channel < NUM_ACTIVE_CHANNELS; ++channel)
              {
                  privatized_decode_op[channel].Init(d_levels[channel], num_output_levels[channel]);
                  if (num_output_levels[channel] > max_levels)
                      max_levels = num_output_levels[channel];
              }
              int max_num_output_bins = max_levels - 1;
  
              // Dispatch
              if (max_num_output_bins > MAX_PRIVATIZED_SMEM_BINS)
              {
                  // Too many bins to keep in shared memory.
                  const int PRIVATIZED_SMEM_BINS = 0;
  
                  if (CubDebug(error = PrivatizedDispatch(
                      d_temp_storage,
                      temp_storage_bytes,
                      d_samples,
                      d_output_histograms,
                      num_output_levels,
                      privatized_decode_op,
                      num_output_levels,
                      output_decode_op,
                      max_num_output_bins,
                      num_row_pixels,
                      num_rows,
                      row_stride_samples,
                      DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                      DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                      histogram_sweep_config,
                      stream,
                      debug_synchronous))) break;
              }
              else
              {
                  // Dispatch shared-privatized approach
                  const int PRIVATIZED_SMEM_BINS = MAX_PRIVATIZED_SMEM_BINS;
  
                  if (CubDebug(error = PrivatizedDispatch(
                      d_temp_storage,
                      temp_storage_bytes,
                      d_samples,
                      d_output_histograms,
                      num_output_levels,
                      privatized_decode_op,
                      num_output_levels,
                      output_decode_op,
                      max_num_output_bins,
                      num_row_pixels,
                      num_rows,
                      row_stride_samples,
                      DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                      DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                      histogram_sweep_config,
                      stream,
                      debug_synchronous))) break;
              }
  
          } while (0);
  
          return error;
      }
  
  
      /**
       * Dispatch routine for HistogramRange, specialized for 8-bit sample types (computes 256-bin privatized histograms and then reduces to user-specified levels)
       */
      CUB_RUNTIME_FUNCTION
      static cudaError_t DispatchRange(
          void*               d_temp_storage,                             ///< [in] %Device-accessible allocation of temporary storage.  When NULL, the required allocation size is written to \p temp_storage_bytes and no work is done.
          size_t&             temp_storage_bytes,                         ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
          SampleIteratorT     d_samples,                                  ///< [in] The pointer to the multi-channel input sequence of data samples. The samples from different channels are assumed to be interleaved (e.g., an array of 32-bit pixels where each pixel consists of four RGBA 8-bit samples).
          CounterT*           d_output_histograms[NUM_ACTIVE_CHANNELS],   ///< [out] The pointers to the histogram counter output arrays, one for each active channel.  For channel<sub><em>i</em></sub>, the allocation length of <tt>d_histograms[i]</tt> should be <tt>num_output_levels[i]</tt> - 1.
          int                 num_output_levels[NUM_ACTIVE_CHANNELS],     ///< [in] The number of boundaries (levels) for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          LevelT              *d_levels[NUM_ACTIVE_CHANNELS],             ///< [in] The pointers to the arrays of boundaries (levels), one for each active channel.  Bin ranges are defined by consecutive boundary pairings: lower sample value boundaries are inclusive and upper sample value boundaries are exclusive.
          OffsetT             num_row_pixels,                             ///< [in] The number of multi-channel pixels per row in the region of interest
          OffsetT             num_rows,                                   ///< [in] The number of rows in the region of interest
          OffsetT             row_stride_samples,                         ///< [in] The number of samples between starts of consecutive rows in the region of interest
          cudaStream_t        stream,                                     ///< [in] CUDA stream to launch kernels within.  Default is stream<sub>0</sub>.
          bool                debug_synchronous,                          ///< [in] Whether or not to synchronize the stream after every kernel launch to check for errors.  May cause significant slowdown.  Default is \p false.
          Int2Type<true>      is_byte_sample)                             ///< [in] Marker type indicating whether or not SampleT is a 8b type
      {
          cudaError error = cudaSuccess;
          do
          {
              // Get PTX version
              int ptx_version;
      #if (CUB_PTX_ARCH == 0)
              if (CubDebug(error = PtxVersion(ptx_version))) break;
      #else
              ptx_version = CUB_PTX_ARCH;
      #endif
  
              // Get kernel dispatch configurations
              KernelConfig histogram_sweep_config;
              if (CubDebug(error = InitConfigs(ptx_version, histogram_sweep_config)))
                  break;
  
              // Use the pass-thru transform op for converting samples to privatized bins
              typedef PassThruTransform PrivatizedDecodeOpT;
  
              // Use the search transform op for converting privatized bins to output bins
              typedef SearchTransform<LevelT*> OutputDecodeOpT;
  
              int                         num_privatized_levels[NUM_ACTIVE_CHANNELS];
              PrivatizedDecodeOpT         privatized_decode_op[NUM_ACTIVE_CHANNELS];
              OutputDecodeOpT             output_decode_op[NUM_ACTIVE_CHANNELS];
              int                         max_levels = num_output_levels[0];              // Maximum number of levels in any channel
  
              for (int channel = 0; channel < NUM_ACTIVE_CHANNELS; ++channel)
              {
                  num_privatized_levels[channel] = 257;
                  output_decode_op[channel].Init(d_levels[channel], num_output_levels[channel]);
  
                  if (num_output_levels[channel] > max_levels)
                      max_levels = num_output_levels[channel];
              }
              int max_num_output_bins = max_levels - 1;
  
              const int PRIVATIZED_SMEM_BINS = 256;
  
              if (CubDebug(error = PrivatizedDispatch(
                  d_temp_storage,
                  temp_storage_bytes,
                  d_samples,
                  d_output_histograms,
                  num_privatized_levels,
                  privatized_decode_op,
                  num_output_levels,
                  output_decode_op,
                  max_num_output_bins,
                  num_row_pixels,
                  num_rows,
                  row_stride_samples,
                  DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                  DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                  histogram_sweep_config,
                  stream,
                  debug_synchronous))) break;
  
          } while (0);
  
          return error;
      }
  
  
      /**
       * Dispatch routine for HistogramEven, specialized for sample types larger than 8-bit
       */
      CUB_RUNTIME_FUNCTION __forceinline__
      static cudaError_t DispatchEven(
          void*               d_temp_storage,                            ///< [in] %Device-accessible allocation of temporary storage.  When NULL, the required allocation size is written to \p temp_storage_bytes and no work is done.
          size_t&             temp_storage_bytes,                        ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
          SampleIteratorT     d_samples,                                  ///< [in] The pointer to the input sequence of sample items. The samples from different channels are assumed to be interleaved (e.g., an array of 32-bit pixels where each pixel consists of four RGBA 8-bit samples).
          CounterT*           d_output_histograms[NUM_ACTIVE_CHANNELS],  ///< [out] The pointers to the histogram counter output arrays, one for each active channel.  For channel<sub><em>i</em></sub>, the allocation length of <tt>d_histograms[i]</tt> should be <tt>num_output_levels[i]</tt> - 1.
          int                 num_output_levels[NUM_ACTIVE_CHANNELS],     ///< [in] The number of bin level boundaries for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          LevelT              lower_level[NUM_ACTIVE_CHANNELS],           ///< [in] The lower sample value bound (inclusive) for the lowest histogram bin in each active channel.
          LevelT              upper_level[NUM_ACTIVE_CHANNELS],           ///< [in] The upper sample value bound (exclusive) for the highest histogram bin in each active channel.
          OffsetT             num_row_pixels,                             ///< [in] The number of multi-channel pixels per row in the region of interest
          OffsetT             num_rows,                                   ///< [in] The number of rows in the region of interest
          OffsetT             row_stride_samples,                         ///< [in] The number of samples between starts of consecutive rows in the region of interest
          cudaStream_t        stream,                                     ///< [in] CUDA stream to launch kernels within.  Default is stream<sub>0</sub>.
          bool                debug_synchronous,                          ///< [in] Whether or not to synchronize the stream after every kernel launch to check for errors.  May cause significant slowdown.  Default is \p false.
          Int2Type<false>     is_byte_sample)                             ///< [in] Marker type indicating whether or not SampleT is a 8b type
      {
          cudaError error = cudaSuccess;
          do
          {
              // Get PTX version
              int ptx_version;
      #if (CUB_PTX_ARCH == 0)
              if (CubDebug(error = PtxVersion(ptx_version))) break;
      #else
              ptx_version = CUB_PTX_ARCH;
      #endif
  
              // Get kernel dispatch configurations
              KernelConfig histogram_sweep_config;
              if (CubDebug(error = InitConfigs(ptx_version, histogram_sweep_config)))
                  break;
  
              // Use the scale transform op for converting samples to privatized bins
              typedef ScaleTransform PrivatizedDecodeOpT;
  
              // Use the pass-thru transform op for converting privatized bins to output bins
              typedef PassThruTransform OutputDecodeOpT;
  
              PrivatizedDecodeOpT         privatized_decode_op[NUM_ACTIVE_CHANNELS];
              OutputDecodeOpT             output_decode_op[NUM_ACTIVE_CHANNELS];
              int                         max_levels = num_output_levels[0];
  
              for (int channel = 0; channel < NUM_ACTIVE_CHANNELS; ++channel)
              {
                  int     bins    = num_output_levels[channel] - 1;
                  LevelT  scale   = (upper_level[channel] - lower_level[channel]) / bins;
  
                  privatized_decode_op[channel].Init(num_output_levels[channel], upper_level[channel], lower_level[channel], scale);
  
                  if (num_output_levels[channel] > max_levels)
                      max_levels = num_output_levels[channel];
              }
              int max_num_output_bins = max_levels - 1;
  
              if (max_num_output_bins > MAX_PRIVATIZED_SMEM_BINS)
              {
                  // Dispatch shared-privatized approach
                  const int PRIVATIZED_SMEM_BINS = 0;
  
                  if (CubDebug(error = PrivatizedDispatch(
                      d_temp_storage,
                      temp_storage_bytes,
                      d_samples,
                      d_output_histograms,
                      num_output_levels,
                      privatized_decode_op,
                      num_output_levels,
                      output_decode_op,
                      max_num_output_bins,
                      num_row_pixels,
                      num_rows,
                      row_stride_samples,
                      DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                      DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                      histogram_sweep_config,
                      stream,
                      debug_synchronous))) break;
              }
              else
              {
                  // Dispatch shared-privatized approach
                  const int PRIVATIZED_SMEM_BINS = MAX_PRIVATIZED_SMEM_BINS;
  
                  if (CubDebug(error = PrivatizedDispatch(
                      d_temp_storage,
                      temp_storage_bytes,
                      d_samples,
                      d_output_histograms,
                      num_output_levels,
                      privatized_decode_op,
                      num_output_levels,
                      output_decode_op,
                      max_num_output_bins,
                      num_row_pixels,
                      num_rows,
                      row_stride_samples,
                      DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                      DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                      histogram_sweep_config,
                      stream,
                      debug_synchronous))) break;
              }
          }
          while (0);
  
          return error;
      }
  
  
      /**
       * Dispatch routine for HistogramEven, specialized for 8-bit sample types (computes 256-bin privatized histograms and then reduces to user-specified levels)
       */
      CUB_RUNTIME_FUNCTION __forceinline__
      static cudaError_t DispatchEven(
          void*               d_temp_storage,                            ///< [in] %Device-accessible allocation of temporary storage.  When NULL, the required allocation size is written to \p temp_storage_bytes and no work is done.
          size_t&             temp_storage_bytes,                        ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
          SampleIteratorT     d_samples,                                  ///< [in] The pointer to the input sequence of sample items. The samples from different channels are assumed to be interleaved (e.g., an array of 32-bit pixels where each pixel consists of four RGBA 8-bit samples).
          CounterT*           d_output_histograms[NUM_ACTIVE_CHANNELS],  ///< [out] The pointers to the histogram counter output arrays, one for each active channel.  For channel<sub><em>i</em></sub>, the allocation length of <tt>d_histograms[i]</tt> should be <tt>num_output_levels[i]</tt> - 1.
          int                 num_output_levels[NUM_ACTIVE_CHANNELS],     ///< [in] The number of bin level boundaries for delineating histogram samples in each active channel.  Implies that the number of bins for channel<sub><em>i</em></sub> is <tt>num_output_levels[i]</tt> - 1.
          LevelT              lower_level[NUM_ACTIVE_CHANNELS],           ///< [in] The lower sample value bound (inclusive) for the lowest histogram bin in each active channel.
          LevelT              upper_level[NUM_ACTIVE_CHANNELS],           ///< [in] The upper sample value bound (exclusive) for the highest histogram bin in each active channel.
          OffsetT             num_row_pixels,                             ///< [in] The number of multi-channel pixels per row in the region of interest
          OffsetT             num_rows,                                   ///< [in] The number of rows in the region of interest
          OffsetT             row_stride_samples,                         ///< [in] The number of samples between starts of consecutive rows in the region of interest
          cudaStream_t        stream,                                     ///< [in] CUDA stream to launch kernels within.  Default is stream<sub>0</sub>.
          bool                debug_synchronous,                          ///< [in] Whether or not to synchronize the stream after every kernel launch to check for errors.  May cause significant slowdown.  Default is \p false.
          Int2Type<true>      is_byte_sample)                             ///< [in] Marker type indicating whether or not SampleT is a 8b type
      {
          cudaError error = cudaSuccess;
          do
          {
              // Get PTX version
              int ptx_version;
      #if (CUB_PTX_ARCH == 0)
              if (CubDebug(error = PtxVersion(ptx_version))) break;
      #else
              ptx_version = CUB_PTX_ARCH;
      #endif
  
              // Get kernel dispatch configurations
              KernelConfig histogram_sweep_config;
              if (CubDebug(error = InitConfigs(ptx_version, histogram_sweep_config)))
                  break;
  
              // Use the pass-thru transform op for converting samples to privatized bins
              typedef PassThruTransform PrivatizedDecodeOpT;
  
              // Use the scale transform op for converting privatized bins to output bins
              typedef ScaleTransform OutputDecodeOpT;
  
              int                     num_privatized_levels[NUM_ACTIVE_CHANNELS];
              PrivatizedDecodeOpT     privatized_decode_op[NUM_ACTIVE_CHANNELS];
              OutputDecodeOpT         output_decode_op[NUM_ACTIVE_CHANNELS];
              int                     max_levels = num_output_levels[0];
  
              for (int channel = 0; channel < NUM_ACTIVE_CHANNELS; ++channel)
              {
                  num_privatized_levels[channel] = 257;
  
                  int     bins    = num_output_levels[channel] - 1;
                  LevelT  scale   = (upper_level[channel] - lower_level[channel]) / bins;
                  output_decode_op[channel].Init(num_output_levels[channel], upper_level[channel], lower_level[channel], scale);
  
                  if (num_output_levels[channel] > max_levels)
                      max_levels = num_output_levels[channel];
              }
              int max_num_output_bins = max_levels - 1;
  
              const int PRIVATIZED_SMEM_BINS = 256;
  
              if (CubDebug(error = PrivatizedDispatch(
                  d_temp_storage,
                  temp_storage_bytes,
                  d_samples,
                  d_output_histograms,
                  num_privatized_levels,
                  privatized_decode_op,
                  num_output_levels,
                  output_decode_op,
                  max_num_output_bins,
                  num_row_pixels,
                  num_rows,
                  row_stride_samples,
                  DeviceHistogramInitKernel<NUM_ACTIVE_CHANNELS, CounterT, OffsetT>,
                  DeviceHistogramSweepKernel<PtxHistogramSweepPolicy, PRIVATIZED_SMEM_BINS, NUM_CHANNELS, NUM_ACTIVE_CHANNELS, SampleIteratorT, CounterT, PrivatizedDecodeOpT, OutputDecodeOpT, OffsetT>,
                  histogram_sweep_config,
                  stream,
                  debug_synchronous))) break;
  
          }
          while (0);
  
          return error;
      }
  
  };
  
  
  }               // CUB namespace
  CUB_NS_POSTFIX  // Optional outer namespace(s)