Merge pull request #9206 from The-OpenROAD-Project-staging/grt-extra-step

grt: new resistance-aware strategy

Author: maliberty

src/grt/src/GlobalRouter.cpp

@@ -335,6 +335,7 @@ void GlobalRouter::globalRoute(bool save_guides,
   } else {
     try {
       if (end_incremental) {
+        fastroute_->setResistanceAware(resistance_aware_);
         updateDirtyRoutes();
         grouter_cbk_->removeOwner();
         delete grouter_cbk_;

src/grt/src/fastroute/include/DataType.h

@@ -106,6 +106,10 @@ struct FrNet  // A Net is a set of connected MazePoints
   bool isSoftNDR() { return is_soft_ndr_; }
   void setIsResAware(bool res_aware) { is_res_aware_ = res_aware; }
   bool isResAware() { return is_res_aware_; }
+  float getResistance() { return resistance_; }
+  void setResistance(float resistance) { resistance_ = resistance; }
+  int getNetLength() { return net_length_; }
+  void setNetLength(int net_length) { net_length_ = net_length; }
 
  private:
   odb::dbNet* db_net_;
@@ -121,6 +125,8 @@ struct FrNet  // A Net is a set of connected MazePoints
   float slack_;
   bool is_soft_ndr_ = false;
   bool is_res_aware_ = false;
+  float resistance_;
+  int net_length_;
   // Non-null when an NDR has been applied to the net.
   std::unique_ptr<std::vector<int8_t>> edge_cost_per_layer_;
 };
@@ -240,8 +246,7 @@ struct OrderNetPin
   int minX;
   float length_per_pin;  // net length over pin count
   int ndr_priority;      // NDR nets are assigned first
-  int res_aware;
-  float slack;
+  float res_aware_score;
   int clock;
 };
 

src/grt/src/fastroute/include/FastRoute.h

@@ -229,6 +229,7 @@ class FastRouteCore
   void setCongestionReportIterStep(int congestion_report_iter_step);
   void setCongestionReportFile(const char* congestion_file_name);
   void setGridMax(int x_max, int y_max);
+  void setDetourPenalty(int penalty);
   void getCongestionNets(std::set<odb::dbNet*>& congestion_nets);
   void computeCongestionInformation();
   std::vector<int> getOriginalResources();
@@ -287,7 +288,7 @@ class FastRouteCore
   double dbuToMicrons(int dbu);
   odb::Rect globalRoutingToBox(const GSegment& route);
   NetRouteMap getRoutes();
-  void updateSlacks(float percentage = 1);
+  void updateSlacks(float percentage = 0.15);
   void preProcessTechLayers();
   odb::dbTechLayer* getTechLayer(int layer, bool is_via);
 
@@ -383,7 +384,8 @@ class FastRouteCore
                          std::vector<int*>& points_heap_3D,
                          multi_array<int, 3>& dist_3D,
                          multi_array<Direction, 3>& directions_3D,
-                         multi_array<int, 3>& corr_edge_3D);
+                         multi_array<int, 3>& corr_edge_3D,
+                         multi_array<int, 3>& path_len_3D);
   void setupHeap3D(int netID,
                    int edgeID,
                    std::vector<int*>& src_heap_3D,
@@ -392,6 +394,7 @@ class FastRouteCore
                    multi_array<int, 3>& corr_edge_3D,
                    multi_array<int, 3>& d1_3D,
                    multi_array<int, 3>& d2_3D,
+                   multi_array<int, 3>& path_len_3D,
                    int regionX1,
                    int regionX2,
                    int regionY1,
@@ -537,16 +540,24 @@ class FastRouteCore
                          multi_array<int, 2>& layer_grid,
                          int net_cost);
   void assignEdge(int netID, int edgeID, bool processDIR);
-  int getLayerResistance(int layer, int length, FrNet* net);
-  int getViaResistance(int from_layer, int to_layer);
-  bool needResistanceAware(int net_id);
   void recoverEdge(int netID, int edgeID);
   void layerAssignmentV4();
   void netpinOrderInc();
   void checkRoute3D();
   void StNetOrder();
   float CalculatePartialSlack();
   float getNetSlack(odb::dbNet* net);
+
+  // Resistance-aware related functions
+  float getWireResistance(int layer, int length, FrNet* net);
+  float getViaResistance(int from_layer, int to_layer);
+  int getWireCost(int layer, int length, FrNet* net);
+  int getViaCost(int from_layer, int to_layer);
+  float getNetResistance(FrNet* net, bool assume_layer = false);
+  float getResAwareScore(FrNet* net);
+  void updateWorstMetrics(FrNet* net);
+  void resetWorstMetrics();
+
   /**
    * @brief Validates the routing of edges for a specified net.
    *
@@ -622,6 +633,10 @@ class FastRouteCore
   bool enable_resistance_aware_ = false;
   bool is_3d_step_ = false;
   bool is_incremental_grt_ = false;
+  float worst_slack_;
+  float worst_net_resistance_;
+  int worst_net_length_;
+  int worst_fanout_;
   int num_adjust_;
   int v_capacity_;
   int h_capacity_;
@@ -718,6 +733,8 @@ class FastRouteCore
   std::vector<int*> dest_heap_3D_;
   multi_array<int, 3> d1_3D_;
   multi_array<int, 3> d2_3D_;
+  multi_array<int, 3> path_len_3D_;
+  int detour_penalty_;
 };
 
 extern const char* getNetName(odb::dbNet* db_net);

src/grt/src/fastroute/src/FastRoute.cpp

@@ -128,6 +128,8 @@ void FastRouteCore::clear()
 
   vertical_blocked_intervals_.clear();
   horizontal_blocked_intervals_.clear();
+
+  detour_penalty_ = 0;
 }
 
 void FastRouteCore::clearNets()
@@ -203,6 +205,7 @@ void FastRouteCore::setGridsAndLayers(int x, int y, int nLayers)
 
   d1_3D_.resize(boost::extents[num_layers_][y_range_][x_range_]);
   d2_3D_.resize(boost::extents[num_layers_][y_range_][x_range_]);
+  path_len_3D_.resize(boost::extents[num_layers_][y_range_][x_range_]);
 }
 
 void FastRouteCore::addVCapacity(int16_t verticalCapacity, int layer)
@@ -1371,7 +1374,7 @@ NetRouteMap FastRouteCore::run()
   int slope;
   int max_adj;
   int long_edge_len = 40;
-  const int short_edge_len = 12;
+  int short_edge_len = 12;
   const int soft_ndr_overflow_th = 10000;
 
   // call FLUTE to generate RSMT and break the nets into segments (2-pin nets)
@@ -1471,6 +1474,7 @@ NetRouteMap FastRouteCore::run()
   if (debug_->isOn() && debug_->rectilinearSTree) {
     for (const int& netID : net_ids_) {
       if (nets_[netID]->getDbNet() == debug_->net) {
+        logger_->report("RST Tree before overflow iterations");
         StTreeVisualization(sttrees_[netID], nets_[netID], false);
       }
     }
@@ -1759,9 +1763,9 @@ NetRouteMap FastRouteCore::run()
 
   // Debug mode Tree 2D after overflow iterations
   if (debug_->isOn() && debug_->tree2D) {
-    logger_->report("Tree 2D after overflow iterations");
     for (const int& netID : net_ids_) {
       if (nets_[netID]->getDbNet() == debug_->net) {
+        logger_->report("Tree 2D after overflow iterations");
         StTreeVisualization(sttrees_[netID], nets_[netID], false);
       }
     }
@@ -1812,6 +1816,7 @@ NetRouteMap FastRouteCore::run()
     // Increase ripup threshold if res-aware is enabled
     if (enable_resistance_aware_) {
       long_edge_len = BIG_INT;
+      short_edge_len = BIG_INT;
     }
 
     mazeRouteMSMDOrder3D(enlarge_, 0, long_edge_len);
@@ -1843,6 +1848,7 @@ NetRouteMap FastRouteCore::run()
   if (debug_->isOn() && debug_->tree3D) {
     for (const int& netID : net_ids_) {
       if (nets_[netID]->getDbNet() == debug_->net) {
+        logger_->report("Tree 3D after maze route 3D");
         StTreeVisualization(sttrees_[netID], nets_[netID], true);
       }
     }
@@ -2005,6 +2011,11 @@ void FastRouteCore::setGridMax(int x_max, int y_max)
   y_grid_max_ = y_max;
 }
 
+void FastRouteCore::setDetourPenalty(int penalty)
+{
+  detour_penalty_ = penalty;
+}
+
 std::vector<int> FastRouteCore::getOriginalResources()
 {
   std::vector<int> original_resources(num_layers_);

src/grt/src/fastroute/src/RSMT.cpp

@@ -680,6 +680,7 @@ void FastRouteCore::gen_brk_RSMT(const bool congestionDriven,
     }
     if (debug_->isOn() && debug_->steinerTree
         && net->getDbNet() == debug_->net) {
+      logger_->report("Steiner Tree 2D");
       steinerTreeVisualization(rsmt, net);
     }