Merge pull request #12904 from kronbichler/simplify_mg_code

include/deal.II/matrix_free/matrix_free.templates.h

@@ -835,14 +835,12 @@ namespace internal
     template <typename InIterator>
     void
     resolve_cell(const InIterator &                                  cell,
-                 std::vector<std::pair<unsigned int, unsigned int>> &cell_its,
-                 const unsigned int subdomain_id)
+                 std::vector<std::pair<unsigned int, unsigned int>> &cell_its)
     {
       if (cell->has_children())
         for (unsigned int child = 0; child < cell->n_children(); ++child)
-          resolve_cell(cell->child(child), cell_its, subdomain_id);
-      else if (subdomain_id == numbers::invalid_subdomain_id ||
-               cell->subdomain_id() == subdomain_id)
+          resolve_cell(cell->child(child), cell_its);
+      else if (cell->is_locally_owned())
         {
           Assert(cell->is_active(), ExcInternalError());
           cell_its.emplace_back(cell->level(), cell->index());
@@ -868,32 +866,20 @@ MatrixFree<dim, Number, VectorizedArrayType>::initialize_dof_handlers(
   for (unsigned int no = 0; no < dof_handlers.size(); ++no)
     dof_info[no].vectorization_length = VectorizedArrayType::size();
 
-  const unsigned int n_mpi_procs = task_info.n_procs;
-  const unsigned int my_pid      = task_info.my_pid;
-
   const Triangulation<dim> &tria  = dof_handlers[0]->get_triangulation();
   const unsigned int        level = additional_data.mg_level;
   if (level == numbers::invalid_unsigned_int)
     {
-      if (n_mpi_procs == 1)
-        cell_level_index.reserve(tria.n_active_cells());
-      // For serial Triangulations always take all cells
-      const unsigned int subdomain_id =
-        (dynamic_cast<const parallel::TriangulationBase<dim> *>(
-           &dof_handlers[0]->get_triangulation()) != nullptr) ?
-          my_pid :
-          numbers::invalid_subdomain_id;
+      cell_level_index.reserve(tria.n_active_cells());
 
       // Go through cells on zeroth level and then successively step down into
       // children. This gives a z-ordering of the cells, which is beneficial
       // when setting up neighboring relations between cells for thread
       // parallelization
       for (const auto &cell : tria.cell_iterators_on_level(0))
-        internal::MatrixFreeFunctions::resolve_cell(cell,
-                                                    cell_level_index,
-                                                    subdomain_id);
+        internal::MatrixFreeFunctions::resolve_cell(cell, cell_level_index);
 
-      Assert(n_mpi_procs > 1 ||
+      Assert(task_info.n_procs > 1 ||
                cell_level_index.size() == tria.n_active_cells(),
              ExcInternalError());
     }
@@ -904,7 +890,7 @@ MatrixFree<dim, Number, VectorizedArrayType>::initialize_dof_handlers(
         {
           cell_level_index.reserve(tria.n_cells(level));
           for (const auto &cell : tria.cell_iterators_on_level(level))
-            if (cell->level_subdomain_id() == my_pid)
+            if (cell->is_locally_owned_on_level())
               cell_level_index.emplace_back(cell->level(), cell->index());
         }
     }

source/multigrid/mg_tools.cc

@@ -606,13 +606,8 @@ namespace MGTools
 
     const unsigned int dofs_per_cell = dof.get_fe().n_dofs_per_cell();
     std::vector<types::global_dof_index> dofs_on_this_cell(dofs_per_cell);
-    typename DoFHandler<dim, spacedim>::cell_iterator cell = dof.begin(level),
-                                                      endc = dof.end(level);
-    for (; cell != endc; ++cell)
-      if (dof.get_triangulation().locally_owned_subdomain() ==
-            numbers::invalid_subdomain_id ||
-          cell->level_subdomain_id() ==
-            dof.get_triangulation().locally_owned_subdomain())
+    for (const auto &cell : dof.cell_iterators_on_level(level))
+      if (cell->is_locally_owned_on_level())
         {
           cell->get_mg_dof_indices(dofs_on_this_cell);
           constraints.add_entries_local_to_global(dofs_on_this_cell,
@@ -1348,9 +1343,7 @@ namespace MGTools
       {
         for (const auto &cell : dof.cell_iterators())
           {
-            if (dof.get_triangulation().locally_owned_subdomain() !=
-                  numbers::invalid_subdomain_id &&
-                cell->level_subdomain_id() == numbers::artificial_subdomain_id)
+            if (cell->is_artificial_on_level())
               continue;
             const FiniteElement<dim> &fe    = cell->get_fe();
             const unsigned int        level = cell->level();
@@ -1380,9 +1373,7 @@ namespace MGTools
                  "It's probably worthwhile to select at least one component."));
 
         for (const auto &cell : dof.cell_iterators())
-          if (dof.get_triangulation().locally_owned_subdomain() ==
-                numbers::invalid_subdomain_id ||
-              cell->level_subdomain_id() != numbers::artificial_subdomain_id)
+          if (!cell->is_artificial_on_level())
             for (const unsigned int face_no : GeometryInfo<dim>::face_indices())
               {
                 if (cell->at_boundary(face_no) == false)
@@ -1508,9 +1499,7 @@ namespace MGTools
       {
         // Do not look at artificial level cells (in a serial computation we
         // need to ignore the level_subdomain_id() because it is never set).
-        if (mg_dof_handler.get_triangulation().locally_owned_subdomain() !=
-              numbers::invalid_subdomain_id &&
-            cell->level_subdomain_id() == numbers::artificial_subdomain_id)
+        if (cell->is_artificial_on_level())
           continue;
 
         bool has_coarser_neighbor = false;
@@ -1529,11 +1518,7 @@ namespace MGTools
 
                 // only process cell pairs if one or both of them are owned by
                 // me (ignore if running in serial)
-                if (mg_dof_handler.get_triangulation()
-                        .locally_owned_subdomain() !=
-                      numbers::invalid_subdomain_id &&
-                    neighbor->level_subdomain_id() ==
-                      numbers::artificial_subdomain_id)
+                if (neighbor->is_artificial_on_level())
                   continue;
 
                 // Do refinement face from the coarse side

source/multigrid/mg_transfer_prebuilt.cc

@@ -215,17 +215,11 @@ MGTransferPrebuilt<VectorType>::build(
       DoFTools::extract_locally_relevant_level_dofs(dof_handler,
                                                     level + 1,
                                                     level_p1_relevant_dofs);
-      DynamicSparsityPattern                  dsp(this->sizes[level + 1],
+      DynamicSparsityPattern dsp(this->sizes[level + 1],
                                  this->sizes[level],
                                  level_p1_relevant_dofs);
-      typename DoFHandler<dim>::cell_iterator cell,
-        endc = dof_handler.end(level);
-      for (cell = dof_handler.begin(level); cell != endc; ++cell)
-        if (cell->has_children() &&
-            (dof_handler.get_triangulation().locally_owned_subdomain() ==
-               numbers::invalid_subdomain_id ||
-             cell->level_subdomain_id() ==
-               dof_handler.get_triangulation().locally_owned_subdomain()))
+      for (const auto &cell : dof_handler.cell_iterators_on_level(level))
+        if (cell->has_children() && cell->is_locally_owned_on_level())
           {
             cell->get_mg_dof_indices(dof_indices_parent);
 
@@ -301,12 +295,8 @@ MGTransferPrebuilt<VectorType>::build(
       FullMatrix<typename VectorType::value_type> prolongation;
 
       // now actually build the matrices
-      for (cell = dof_handler.begin(level); cell != endc; ++cell)
-        if (cell->has_children() &&
-            (dof_handler.get_triangulation().locally_owned_subdomain() ==
-               numbers::invalid_subdomain_id ||
-             cell->level_subdomain_id() ==
-               dof_handler.get_triangulation().locally_owned_subdomain()))
+      for (const auto &cell : dof_handler.cell_iterators_on_level(level))
+        if (cell->has_children() && cell->is_locally_owned_on_level())
           {
             cell->get_mg_dof_indices(dof_indices_parent);