Point Cloud Library (PCL)  1.14.1-dev
bitonic_sort.hpp
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34 * Author: Anatoly Baskeheev, Itseez Ltd, (myname.mysurname@mycompany.com)
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36 
37 #ifndef PCL_GPU_BITONIC_SORT_WARP_HPP
38 #define PCL_GPU_BITONIC_SORT_WARP_HPP
39 
40 namespace pcl
41 {
42  namespace device
43  {
44  template<typename T>
45  __device__ __forceinline__ void swap(T& a, T& b) { T t = a; a = b; b = t; }
46 
47  template<typename V, typename K>
48  __device__ __forceinline__ void bitonicSortWarp(volatile K* keys, volatile V* vals, unsigned int dir = 1)
49  {
50  const unsigned int arrayLength = 64;
51  unsigned int lane = threadIdx.x & 31;
52 
53  for(unsigned int size = 2; size < arrayLength; size <<= 1)
54  {
55  //Bitonic merge
56  unsigned int ddd = dir ^ ( (lane & (size / 2)) != 0 );
57 
58  for(unsigned int stride = size / 2; stride > 0; stride >>= 1)
59  {
60  unsigned int pos = 2 * lane - (lane & (stride - 1));
61 
62  if ( (keys[pos] > keys[pos + stride]) == ddd )
63  {
64  swap(keys[pos], keys[pos + stride]);
65  swap(vals[pos], vals[pos + stride]);
66  }
67  }
68  }
69 
70  //ddd == dir for the last bitonic merge step
71  for(unsigned int stride = arrayLength / 2; stride > 0; stride >>= 1)
72  {
73  unsigned int pos = 2 * lane - (lane & (stride - 1));
74 
75  if ( (keys[pos] > keys[pos + stride]) == dir )
76  {
77  swap(keys[pos], keys[pos + stride]);
78  swap(vals[pos], vals[pos + stride]);
79  }
80  }
81  }
82 
83  }
84 }
85 
86 #endif /* PCL_GPU_BITONIC_SORT_WARP_HPP */
@ K
Definition: norms.h:54
__device__ __forceinline__ void bitonicSortWarp(volatile K *keys, volatile V *vals, unsigned int dir=1)
__device__ __host__ __forceinline__ void swap(T &a, T &b)
Definition: utils.hpp:53