Ejemplo n.º 1
0
void copy(matrix_slice<matrix<NumericT, column_major, 1> > const & gpu_matrix_slice,
          CPUMatrixT & cpu_matrix)
{
  assert( (cpu_matrix.size1() == gpu_matrix_slice.size1())
          && (cpu_matrix.size2() == gpu_matrix_slice.size2())
          && bool("Matrix size mismatch!"));

  if ( (gpu_matrix_slice.size1() > 0) && (gpu_matrix_slice.size1() > 0) )
  {
    vcl_size_t num_entries = gpu_matrix_slice.size1() * gpu_matrix_slice.stride1(); //no. of entries per stride

    std::vector<NumericT> entries(num_entries);

    //copy each column stride separately:
    for (vcl_size_t j=0; j < gpu_matrix_slice.size2(); ++j)
    {
      vcl_size_t start_offset = gpu_matrix_slice.start1() + (gpu_matrix_slice.start2() + j * gpu_matrix_slice.stride2()) * gpu_matrix_slice.internal_size1();

      viennacl::backend::memory_read(gpu_matrix_slice.handle(), sizeof(NumericT)*start_offset, sizeof(NumericT)*num_entries, &(entries[0]));

      for (vcl_size_t i=0; i < gpu_matrix_slice.size1(); ++i)
        cpu_matrix(i,j) = entries[i * gpu_matrix_slice.stride1()];
    }
  }

}
Ejemplo n.º 2
0
 matrix_slice(matrix_slice<MatrixType> const & A,
              slice const & row_slice,
              slice const & col_slice) : base_type(const_cast<handle_type &>(A.handle()),
                                                   row_slice.size(), row_slice.start() * A.stride1() + A.start1(), row_slice.stride() * A.stride1(), A.internal_size1(),
                                                   col_slice.size(), col_slice.start() * A.stride2() + A.start2(), col_slice.stride() * A.stride2(), A.internal_size2(),
                                                   A.row_major()) {}