-----------------------------------------------------------------------------
| 118 | |
| 119 | //----------------------------------------------------------------------------- |
| 120 | graph::AdjacencyList<std::int32_t> fem::transpose_dofmap( |
| 121 | md::mdspan<const std::int32_t, md::dextents<std::size_t, 2>> dofmap, |
| 122 | std::int32_t num_cells) |
| 123 | { |
| 124 | // Count number of cell contributions to each global index |
| 125 | const std::int32_t max_index = *std::max_element( |
| 126 | dofmap.data_handle(), |
| 127 | std::next(dofmap.data_handle(), num_cells * dofmap.extent(1))); |
| 128 | |
| 129 | std::vector<int> num_local_contributions(max_index + 1, 0); |
| 130 | for (std::int32_t c = 0; c < num_cells; ++c) |
| 131 | { |
| 132 | auto dofs = md::submdspan(dofmap, c, md::full_extent); |
| 133 | for (std::size_t d = 0; d < dofmap.extent(1); ++d) |
| 134 | num_local_contributions[dofs[d]]++; |
| 135 | } |
| 136 | |
| 137 | // Compute offset for each global index |
| 138 | std::vector<int> index_offsets(num_local_contributions.size() + 1, 0); |
| 139 | std::partial_sum(num_local_contributions.begin(), |
| 140 | num_local_contributions.end(), index_offsets.begin() + 1); |
| 141 | |
| 142 | std::vector<std::int32_t> data(index_offsets.back()); |
| 143 | std::vector<int> pos = index_offsets; |
| 144 | int cell_offset = 0; |
| 145 | for (std::int32_t c = 0; c < num_cells; ++c) |
| 146 | { |
| 147 | auto dofs = md::submdspan(dofmap, c, md::full_extent); |
| 148 | for (std::size_t d = 0; d < dofmap.extent(1); ++d) |
| 149 | data[pos[dofs[d]]++] = cell_offset++; |
| 150 | } |
| 151 | |
| 152 | // Sort the source indices for each global index |
| 153 | // This could improve linear memory access |
| 154 | // FIXME: needs profiling |
| 155 | for (int index = 0; index < max_index; ++index) |
| 156 | { |
| 157 | std::sort(data.begin() + index_offsets[index], |
| 158 | data.begin() + index_offsets[index + 1]); |
| 159 | } |
| 160 | |
| 161 | return graph::AdjacencyList(std::move(data), std::move(index_offsets)); |
| 162 | } |
| 163 | //----------------------------------------------------------------------------- |
| 164 | bool DofMap::operator==(const DofMap& map) const |
| 165 | { |