message: Use C copysign() in CUDA kernels
diff: @@ -25,7 +25,11 @@ using std::acos;
  using std::asin;
  using std::atan;
  using std::ceil;
  +#ifdef __CUDA_ARCH__
  +using ::copysign;
  +#else
  using std::copysign;
  +#endif
  using std::cos;
  using std::exp;
  using std::floor;
  