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Stokhos_Cuda_WarpShuffle.hpp
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41 
42 #ifndef STOKHOS_CUDA_WARP_SHUFFLE_HPP
43 #define STOKHOS_CUDA_WARP_SHUFFLE_HPP
44 
45 #include "Kokkos_Core.hpp"
46 
47 #ifdef __CUDA_ARCH__
48 # if (__CUDA_ARCH__ >= 300)
49 # define HAVE_CUDA_SHUFFLE 1
50 # else
51 # define HAVE_CUDA_SHUFFLE 0
52 # endif
53 #else
54 # define HAVE_CUDA_SHUFFLE 0
55 #endif
56 
57 
58 namespace Stokhos {
59 
60 template<typename Scalar>
61 KOKKOS_INLINE_FUNCTION
62 Scalar shfl_down(const Scalar &val, const int& delta, const int& width){
63  return val;
64 }
65 
66 template<typename Scalar>
67 KOKKOS_INLINE_FUNCTION
68 Scalar shfl_up(const Scalar &val, const int& delta, const int& width){
69  return val;
70 }
71 
72 
73 #if HAVE_CUDA_SHUFFLE
74 
75 KOKKOS_INLINE_FUNCTION
76 unsigned int shfl_down(
77  const unsigned int &val, const int& delta, const int& width) {
78  unsigned int tmp1 = val;
79  int tmp = *reinterpret_cast<int*>(&tmp1);
80  tmp = __shfl_down(tmp,delta,width);
81  return *reinterpret_cast<unsigned int*>(&tmp);
82 }
83 
84 KOKKOS_INLINE_FUNCTION
85 int shfl_down(const int &val, const int& delta, const int& width) {
86  return __shfl_down(val,delta,width);
87 }
88 
89 KOKKOS_INLINE_FUNCTION
90 float shfl_down(const float &val, const int& delta, const int& width) {
91  return __shfl_down(val,delta,width);
92 }
93 
94 KOKKOS_INLINE_FUNCTION
95 double shfl_down(const double &val, const int& delta, const int& width) {
96  int lo = __double2loint(val);
97  int hi = __double2hiint(val);
98  lo = __shfl_down(lo,delta,width);
99  hi = __shfl_down(hi,delta,width);
100  return __hiloint2double(hi,lo);
101 }
102 
103 KOKKOS_INLINE_FUNCTION
104 unsigned int shfl_up(
105  const unsigned int &val, const int& delta, const int& width) {
106  unsigned int tmp1 = val;
107  int tmp = *reinterpret_cast<int*>(&tmp1);
108  tmp = __shfl_up(tmp,delta,width);
109  return *reinterpret_cast<unsigned int*>(&tmp);
110 }
111 
112 KOKKOS_INLINE_FUNCTION
113 int shfl_up(const int &val, const int& delta, const int& width) {
114  return __shfl_up(val,delta,width);
115 }
116 
117 KOKKOS_INLINE_FUNCTION
118 float shfl_up(const float &val, const int& delta, const int& width) {
119  return __shfl_up(val,delta,width);
120 }
121 
122 KOKKOS_INLINE_FUNCTION
123 double shfl_up(const double &val, const int& delta, const int& width) {
124  int lo = __double2loint(val);
125  int hi = __double2hiint(val);
126  lo = __shfl_up(lo,delta,width);
127  hi = __shfl_up(hi,delta,width);
128  return __hiloint2double(hi,lo);
129 }
130 
131 #endif // #if HAVE_CUDA_SHUFFLE
132 
133 } // namespace Stokhos
134 
135 #endif /* #ifndef STOKHOS_CUDA_WARP_SHUFFLE_HPP */
KOKKOS_INLINE_FUNCTION Scalar shfl_down(const Scalar &val, const int &delta, const int &width)
KOKKOS_INLINE_FUNCTION Scalar shfl_up(const Scalar &val, const int &delta, const int &width)
Top-level namespace for Stokhos classes and functions.
expr val()