opencv/modules/cudev/include/opencv2/cudev/block/scan.hpp
Vladislav Vinogradov 31d55af9c1 CUDA Device Layer:
header only library for CUDA programming
2013-07-03 21:32:15 +04:00

102 lines
3.6 KiB
C++

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#pragma once
#ifndef __OPENCV_CUDEV_BLOCK_SCAN_HPP__
#define __OPENCV_CUDEV_BLOCK_SCAN_HPP__
#include "../common.hpp"
#include "../warp/scan.hpp"
namespace cv { namespace cudev {
template <int THREADS_NUM, typename T>
__device__ T blockScanInclusive(T data, volatile T* smem, uint tid)
{
if (THREADS_NUM > WARP_SIZE)
{
// bottom-level inclusive warp scan
T warpResult = warpScanInclusive(data, smem, tid);
__syncthreads();
// save top elements of each warp for exclusive warp scan
// sync to wait for warp scans to complete (because s_Data is being overwritten)
if ((tid & (WARP_SIZE - 1)) == (WARP_SIZE - 1))
{
smem[tid >> LOG_WARP_SIZE] = warpResult;
}
__syncthreads();
if (tid < (THREADS_NUM / WARP_SIZE))
{
// grab top warp elements
T val = smem[tid];
// calculate exclusive scan and write back to shared memory
smem[tid] = warpScanExclusive(val, smem, tid);
}
__syncthreads();
// return updated warp scans with exclusive scan results
return warpResult + smem[tid >> LOG_WARP_SIZE];
}
else
{
return warpScanInclusive(data, smem, tid);
}
}
template <int THREADS_NUM, typename T>
__device__ __forceinline__ T blockScanExclusive(T data, volatile T* smem, uint tid)
{
return blockScanInclusive<THREADS_NUM>(data, smem, tid) - data;
}
}}
#endif