grt: do not update resources for pin access during incremental mode

src/grt/include/grt/GlobalRouter.h

@@ -351,7 +351,7 @@ class GlobalRouter
                            int track_count,
                            bool horizontal);
   odb::Rect getGCellRect(int x, int y);
-  void initNetlist(std::vector<Net*>& nets);
+  void initNetlist(std::vector<Net*>& nets, bool incremental = false);
   void makeFastrouteNet(Net* net);
   bool pinPositionsChanged(Net* net);
   bool newPinOnGrid(Net* net, std::multiset<RoutePt>& last_pos);
@@ -375,7 +375,7 @@ class GlobalRouter
   void savePositionWithReducedResources(const odb::Rect& rect,
                                         odb::dbTechLayer* tech_layer,
                                         odb::dbNet* db_net);
-  void addResourcesForPinAccess();
+  void addResourcesForPinAccess(const std::vector<Net*>& nets);
   bool isPinReachable(const Pin& pin, const odb::Point& pos_on_grid);
   int computeNetWirelength(odb::dbNet* db_net);
   void computeWirelength();
@@ -529,6 +529,7 @@ class GlobalRouter
   bool is_congested_{false};
   bool use_cugr_{false};
   int skip_large_fanout_{std::numeric_limits<int>::max()};
+  bool has_macros_or_pads_{false};
 
   // Region adjustment variables
   std::vector<RegionAdjustment> region_adjustments_;

src/grt/src/GlobalRouter.cpp

@@ -1303,7 +1303,7 @@ float GlobalRouter::getNetSlack(Net* net)
   return slack;
 }
 
-void GlobalRouter::initNetlist(std::vector<Net*>& nets)
+void GlobalRouter::initNetlist(std::vector<Net*>& nets, bool incremental)
 {
   pad_pins_connections_.clear();
 
@@ -1343,9 +1343,12 @@ void GlobalRouter::initNetlist(std::vector<Net*>& nets)
     logger_->info(GRT, 2, "Maximum degree: {}", max_degree);
   }
 
-  // add resources for pin access in macro/pad pins after defining their on grid
-  // position
-  addResourcesForPinAccess();
+  // Add resources for pin access in macro/pad pins after defining their on grid
+  // position. It must be done only in the initialization of the tool, not
+  // during incremental.
+  if (has_macros_or_pads_ && !incremental) {
+    addResourcesForPinAccess(nets);
+  }
   fastroute_->initAuxVar();
 }
 
@@ -1925,49 +1928,51 @@ void GlobalRouter::applyObstructionAdjustment(const odb::Rect& obstruction,
 // This function adds the resources necessary to route these pins. Only pins in
 // the east and north edges are affected because FastRoute routes from left to
 // right, and bottom to top.
-void GlobalRouter::addResourcesForPinAccess()
+void GlobalRouter::addResourcesForPinAccess(const std::vector<Net*>& nets)
 {
   odb::dbTech* tech = db_->getTech();
-  for (const auto& [db_net, net] : db_net_map_) {
-    for (const Pin& pin : net->getPins()) {
-      if (pin.isConnectedToPadOrMacro() && (pin.getEdge() != PinEdge::none)) {
-        const odb::Point& pos = pin.getOnGridPosition();
-        int pin_x = ((pos.x() - grid_->getXMin()) / grid_->getTileSize());
-        int pin_y = ((pos.y() - grid_->getYMin()) / grid_->getTileSize());
-        const int layer = pin.getConnectionLayer();
-        odb::dbTechLayer* tech_layer = tech->findRoutingLayer(layer);
-        if (tech_layer->getDirection() == odb::dbTechLayerDir::VERTICAL) {
-          const bool north_pin = pin.getEdge() == PinEdge::north;
-          const int pin_y1 = north_pin ? pin_y : pin_y - 1;
-          const int pin_y2 = north_pin ? pin_y + 1 : pin_y;
-
-          // Ensure we do not go out of bounds when the pin is at the edge of
-          // the grid. If the pin is on the south edge and at y=0, there is no
-          // room for adding resources.
-          if (pin_y1 < 0) {
-            continue;
-          }
+  for (const auto& net : nets) {
+    if (net->isConnectedToPadOrMacro()) {
+      for (const Pin& pin : net->getPins()) {
+        if (pin.isConnectedToPadOrMacro() && (pin.getEdge() != PinEdge::none)) {
+          const odb::Point& pos = pin.getOnGridPosition();
+          int pin_x = ((pos.x() - grid_->getXMin()) / grid_->getTileSize());
+          int pin_y = ((pos.y() - grid_->getYMin()) / grid_->getTileSize());
+          const int layer = pin.getConnectionLayer();
+          odb::dbTechLayer* tech_layer = tech->findRoutingLayer(layer);
+          if (tech_layer->getDirection() == odb::dbTechLayerDir::VERTICAL) {
+            const bool north_pin = pin.getEdge() == PinEdge::north;
+            const int pin_y1 = north_pin ? pin_y : pin_y - 1;
+            const int pin_y2 = north_pin ? pin_y + 1 : pin_y;
+
+            // Ensure we do not go out of bounds when the pin is at the edge of
+            // the grid. If the pin is on the south edge and at y=0, there is no
+            // room for adding resources.
+            if (pin_y1 < 0) {
+              continue;
+            }
 
-          const int edge_cap = fastroute_->getEdgeCapacity(
-              pin_x, pin_y1, pin_x, pin_y2, layer);
-          fastroute_->addAdjustment(
-              pin_x, pin_y1, pin_x, pin_y2, layer, edge_cap + 1, false);
-        } else {
-          const bool east_pin = pin.getEdge() == PinEdge::east;
-          const int pin_x1 = east_pin ? pin_x : pin_x - 1;
-          const int pin_x2 = east_pin ? pin_x + 1 : pin_x;
-
-          // Ensure we do not go out of bounds when the pin is at the edge of
-          // the grid. If the pin is on the west edge and at x=0, there is no
-          // room for adding resources.
-          if (pin_x1 < 0) {
-            continue;
-          }
+            const int edge_cap = fastroute_->getEdgeCapacity(
+                pin_x, pin_y1, pin_x, pin_y2, layer);
+            fastroute_->addAdjustment(
+                pin_x, pin_y1, pin_x, pin_y2, layer, edge_cap + 1, false);
+          } else {
+            const bool east_pin = pin.getEdge() == PinEdge::east;
+            const int pin_x1 = east_pin ? pin_x : pin_x - 1;
+            const int pin_x2 = east_pin ? pin_x + 1 : pin_x;
+
+            // Ensure we do not go out of bounds when the pin is at the edge of
+            // the grid. If the pin is on the west edge and at x=0, there is no
+            // room for adding resources.
+            if (pin_x1 < 0) {
+              continue;
+            }
 
-          const int edge_cap = fastroute_->getEdgeCapacity(
-              pin_x1, pin_y, pin_x2, pin_y, layer);
-          fastroute_->addAdjustment(
-              pin_x1, pin_y, pin_x2, pin_y, layer, edge_cap + 1, false);
+            const int edge_cap = fastroute_->getEdgeCapacity(
+                pin_x1, pin_y, pin_x2, pin_y, layer);
+            fastroute_->addAdjustment(
+                pin_x1, pin_y, pin_x2, pin_y, layer, edge_cap + 1, false);
+          }
         }
       }
     }
@@ -4365,6 +4370,10 @@ void GlobalRouter::makeItermPins(Net* net,
     const bool connected_to_pad = type.isPad();
     const bool connected_to_macro = master->isBlock();
 
+    if (connected_to_pad || connected_to_macro) {
+      net->setIsConnectedToPadOrMacro(true);
+    }
+
     odb::dbInst* inst = iterm->getInst();
     if (!inst->isPlaced()) {
       logger_->error(GRT, 10, "Instance {} is not placed.", inst->getName());
@@ -4686,6 +4695,11 @@ int GlobalRouter::findInstancesObstructions(
     if (master->isBlock()) {
       macros_cnt++;
       is_macro = true;
+      has_macros_or_pads_ = true;
+    }
+
+    if (master->getType().isPad()) {
+      has_macros_or_pads_ = true;
     }
 
     if (is_macro) {
@@ -5827,7 +5841,7 @@ void GlobalRouter::getCongestionNets(std::set<odb::dbNet*>& congestion_nets)
 
 void GlobalRouter::initFastRouteIncr(std::vector<Net*>& nets)
 {
-  initNetlist(nets);
+  initNetlist(nets, true);
   fastroute_->initAuxVar();
   fastroute_->setIncrementalGrt(true);
 }

src/grt/src/Net.cpp

@@ -26,7 +26,8 @@ Net::Net(odb::dbNet* net, bool has_wires)
       merged_net_(nullptr),
       is_merged_net_(false),
       is_dirty_net_(false),
-      is_clk_(false)
+      is_clk_(false),
+      is_connected_to_pad_or_macro_(false)
 {
 }
 

src/grt/src/Net.h

@@ -60,6 +60,11 @@ class Net
   bool isDirtyNet() const { return is_dirty_net_; }
   void setIsClockNet(bool is_clk) { is_clk_ = is_clk; }
   bool isClockNet() const { return is_clk_; }
+  void setIsConnectedToPadOrMacro(bool is_connected)
+  {
+    is_connected_to_pad_or_macro_ = is_connected;
+  }
+  bool isConnectedToPadOrMacro() const { return is_connected_to_pad_or_macro_; }
 
  private:
   int getNumBTermsAboveMaxLayer(odb::dbTechLayer* max_routing_layer);
@@ -74,6 +79,7 @@ class Net
   bool is_merged_net_;
   bool is_dirty_net_;
   bool is_clk_;
+  bool is_connected_to_pad_or_macro_;
 };
 
 }  // namespace grt