WIP: 'sparse_array_limit' on DSS

src/db/db/dbDeepShapeStore.cc

@@ -571,13 +571,13 @@ static unsigned int init_layer (db::Layout &layout, const db::RecursiveShapeIter
 }
 
 DeepShapeStore::DeepShapeStore ()
-  : m_keep_layouts (true), m_wants_all_cells (false)
+  : m_keep_layouts (true), m_wants_all_cells (false), m_sparse_array_limit (-1.0)
 {
   ++s_instance_count;
 }
 
 DeepShapeStore::DeepShapeStore (const std::string &topcell_name, double dbu)
-  : m_keep_layouts (true), m_wants_all_cells (false)
+  : m_keep_layouts (true), m_wants_all_cells (false), m_sparse_array_limit (-1.0)
 {
   ++s_instance_count;
 
@@ -865,6 +865,16 @@ bool DeepShapeStore::wants_all_cells () const
   return m_wants_all_cells;
 }
 
+void DeepShapeStore::set_sparse_array_limit (double l)
+{
+  m_sparse_array_limit = l;
+}
+
+double DeepShapeStore::sparse_array_limit () const
+{
+  return m_sparse_array_limit;
+}
+
 void DeepShapeStore::set_reject_odd_polygons (bool f)
 {
   m_state.set_reject_odd_polygons (f);
@@ -1030,6 +1040,7 @@ DeepLayer DeepShapeStore::create_polygon_layer (const db::RecursiveShapeIterator
   db::HierarchyBuilder &builder = m_layouts[layout_index]->builder;
 
   builder.set_wants_all_cells (m_wants_all_cells);
+  builder.set_sparse_array_limit (m_sparse_array_limit);
 
   unsigned int layer_index = init_layer (layout, si);
   builder.set_target_layer (layer_index);
@@ -1064,6 +1075,9 @@ DeepLayer DeepShapeStore::create_custom_layer (const db::RecursiveShapeIterator
   db::Layout &layout = m_layouts[layout_index]->layout;
   db::HierarchyBuilder &builder = m_layouts[layout_index]->builder;
 
+  builder.set_wants_all_cells (m_wants_all_cells);
+  builder.set_sparse_array_limit (m_sparse_array_limit);
+
   unsigned int layer_index = init_layer (layout, si);
   builder.set_target_layer (layer_index);
 

src/db/db/dbDeepShapeStore.h

@@ -701,6 +701,27 @@ public:
    */
   bool wants_all_cells () const;
 
+  /**
+   *  @brief Sets the "sparse array" limit
+   *
+   *  Sparse arrays are instance arrays whose bounding box is no longer a
+   *  good approximation of the covered area. The "sparse array ratio" is
+   *  the area of the bounding box divided by the area of the bounding box
+   *  of a single instance.
+   *
+   *  Arrays above this limit will be resolved into single instances.
+   *
+   *  Setting this value to 0 will resolve all arrays. Setting this
+   *  value to a negative value will never split arrays. The latter
+   *  is the default.
+   */
+  void set_sparse_array_limit (double l);
+
+  /**
+   *  @brief Gets the "sparse array" limit
+   */
+  double sparse_array_limit () const;
+
   /**
    *  @brief Sets a flag indicating whether to reject odd polygons
    *
@@ -858,6 +879,7 @@ private:
   std::list<DeepShapeStoreState> m_state_stack;
   bool m_keep_layouts;
   bool m_wants_all_cells;
+  double m_sparse_array_limit;
   tl::Mutex m_lock;
 
   struct DeliveryMappingCacheKey

src/db/db/dbHierarchyBuilder.cc

@@ -152,14 +152,14 @@ static std::pair<bool, std::set<db::Box> > compute_clip_variant (const db::Box &
 }
 
 HierarchyBuilder::HierarchyBuilder (db::Layout *target, unsigned int target_layer, const db::ICplxTrans &trans, HierarchyBuilderShapeReceiver *pipe)
-  : mp_target (target), m_target_layer (target_layer), m_wants_all_cells (false), m_trans (trans)
+  : mp_target (target), m_target_layer (target_layer), m_wants_all_cells (false), m_trans (trans), m_sparse_array_limit (-1.0)
 {
   set_shape_receiver (pipe);
   reset ();
 }
 
 HierarchyBuilder::HierarchyBuilder (db::Layout *target, const db::ICplxTrans &trans, HierarchyBuilderShapeReceiver *pipe)
-  : mp_target (target), m_target_layer (0), m_wants_all_cells (false), m_trans (trans)
+  : mp_target (target), m_target_layer (0), m_wants_all_cells (false), m_trans (trans), m_sparse_array_limit (-1.0)
 {
   set_shape_receiver (pipe);
   reset ();
@@ -397,19 +397,23 @@ HierarchyBuilder::new_inst (const RecursiveShapeIterator *iter, const db::CellIn
     //  for new cells, create this instance
     if (m_cell_stack.back ().first || m_cm_new_entry) {
 
-      // @@@
-      //  check if the cell array is "sparse"
+      //  check if the cell array is "sparse" according to
+      //  "sparse_array_limit" and resolve into single instances if so
       bool resolve = false;
-      if (m_source.layout () && inst.size () > 1) {
-        db::box_convert<db::CellInst> bc (*m_source.layout ());
-        auto a1 = bc (inst.object ()).area ();
-        auto aa = inst.bbox (bc).area ();
-        double area_ratio = 10.0; // @@@
-        if (a1 * area_ratio < aa) {
+      if (m_sparse_array_limit >= 0.0 && inst.size () > 1) {
+
+        if (m_sparse_array_limit == 0.0) {
           resolve = true;
+        } else {
+          db::box_convert<db::CellInst> bc (*iter->layout ());
+          auto a1 = bc (inst.object ()).area ();
+          auto aa = inst.bbox (bc).area ();
+          if (a1 * m_sparse_array_limit < aa) {
+            resolve = true;
+          }
         }
+
       }
-      // @@@
 
       if (resolve) {
 

src/db/db/dbHierarchyBuilder.h

@@ -314,6 +314,25 @@ public:
     m_wants_all_cells = f;
   }
 
+  /**
+   *  @brief Sets the "sparse array" limit
+   *
+   *  Sparse arrays are instance arrays whose bounding box is no longer a
+   *  good approximation of the covered area. The "sparse array ratio" is
+   *  the area of the bounding box divided by the area of the bounding box
+   *  of a single instance.
+   *
+   *  Arrays above this limit will be resolved into single instances.
+   *
+   *  Setting this value to 0 will resolve all arrays. Setting this
+   *  value to a negative value will never split arrays. The latter
+   *  is the default.
+   */
+  void set_sparse_array_limit (double l)
+  {
+    m_sparse_array_limit = l;
+  }
+
   /**
    *  @brief Reset the builder - performs a new initial pass
    */
@@ -440,6 +459,8 @@ private:
   db::Cell *mp_initial_cell;
 
   db::ICplxTrans m_trans;
+
+  double m_sparse_array_limit;
 };
 
 }

src/db/db/gsiDeclDbDeepShapeStore.cc

@@ -126,6 +126,26 @@ Class<db::DeepShapeStore> decl_dbDeepShapeStore ("db", "DeepShapeStore",
     "@brief Gets a flag wether to copy the full hierarchy for the working layouts\n"
     "This attribute has been introduced in version 0.28.10."
   ) +
+  gsi::method ("sparse_array_limit=", &db::DeepShapeStore::set_sparse_array_limit, gsi::arg ("limit"),
+    "@brief Sets the \"sparse array\" limit\n"
+    "\n"
+    "Sparse arrays are instance arrays whose bounding box is no longer a\n"
+    "good approximation of the covered area. The \"sparse array ratio\" is\n"
+    "the area of the bounding box divided by the area of the bounding box\n"
+    "of a single instance.\n"
+    "\n"
+    "Arrays above this limit will be resolved into single instances.\n"
+    "\n"
+    "Setting this value to 0 will resolve all arrays. Setting this\n"
+    "value to a negative value will never split arrays. The latter\n"
+    "is the default.\n"
+    "\n"
+    "This attribute has been introduced in version 0.30.8."
+  ) +
+  gsi::method ("sparse_array_limit", &db::DeepShapeStore::sparse_array_limit,
+    "@brief Gets the \"sparse array\" limit\n"
+    "This attribute has been introduced in version 0.30.8."
+  ) +
   gsi::method ("reject_odd_polygons=", &db::DeepShapeStore::set_reject_odd_polygons, gsi::arg ("count"),
     "@brief Sets a flag indicating whether to reject odd polygons\n"
     "\n"