grt: add const to Segment fields

Signed-off-by: Matt Liberty <[email protected]>

Author: maliberty

src/grt/include/grt/GlobalRouter.h

@@ -332,7 +332,7 @@ class GlobalRouter
   void computeWirelength();
   std::vector<Pin*> getAllPorts();
   void computeTrackConsumption(const Net* net,
-                               int& track_consumption,
+                               int8_t& track_consumption,
                                std::vector<int8_t>*& edge_costs_per_layer);
 
   // aux functions

src/grt/src/GlobalRouter.cpp

@@ -1163,7 +1163,7 @@ void GlobalRouter::makeFastrouteNet(Net* net)
 
   bool is_clock = (net->getSignalType() == odb::dbSigType::CLOCK);
   std::vector<int8_t>* edge_cost_per_layer;
-  int edge_cost_for_net;
+  int8_t edge_cost_for_net;
   computeTrackConsumption(net, edge_cost_for_net, edge_cost_per_layer);
 
   // set layer restriction only to clock nets that are not connected to
@@ -1249,7 +1249,7 @@ void GlobalRouter::getCapacityReductionData(CapacityReductionData& cap_red_data)
 
 void GlobalRouter::computeTrackConsumption(
     const Net* net,
-    int& track_consumption,
+    int8_t& track_consumption,
     std::vector<int8_t>*& edge_costs_per_layer)
 {
   edge_costs_per_layer = nullptr;
@@ -1289,7 +1289,8 @@ void GlobalRouter::computeTrackConsumption(
       }
       (*edge_costs_per_layer)[layerIdx - 1] = consumption;
 
-      track_consumption = std::max(track_consumption, consumption);
+      track_consumption
+          = std::max(track_consumption, static_cast<int8_t>(consumption));
     }
   }
 }

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

@@ -47,11 +47,15 @@ enum class EdgeDirection
 
 struct Segment  // A Segment is a 2-pin connection
 {
-  int16_t x1, y1, x2, y2;  // coordinates of two endpoints
-  int16_t Zpoint;   // The coordinates of Z point (x for HVH and y for VHV)
-  int8_t cost;      // the netID of the net this segment belonging to
-  bool xFirst : 1;  // route x-direction first (only for L route)
-  bool HVH : 1;     // TRUE = HVH or false = VHV (only for Z route)
+  Segment(int16_t x1, int16_t y1, int16_t x2, int16_t y2, int8_t cost)
+      : x1(x1), y1(y1), x2(x2), y2(y2), cost(cost)
+  {
+  }
+  const int16_t x1, y1, x2, y2;  // coordinates of two endpoints (x1 <= x2)
+  int16_t Zpoint;     // The coordinates of Z point (x for HVH and y for VHV)
+  const int8_t cost;  // the netID of the net this segment belonging to
+  bool xFirst : 1;    // route x-direction first (only for L route)
+  bool HVH : 1;       // TRUE = HVH or false = VHV (only for Z route)
 };
 
 struct FrNet  // A Net is a set of connected MazePoints
@@ -61,7 +65,7 @@ struct FrNet  // A Net is a set of connected MazePoints
   float getSlack() const { return slack_; }
   odb::dbNet* getDbNet() const { return db_net_; }
   int getDriverIdx() const { return driver_idx_; }
-  int getEdgeCost() const { return edge_cost_; }
+  int8_t getEdgeCost() const { return edge_cost_; }
   const char* getName() const;
   int getMaxLayer() const { return max_layer_; }
   int getMinLayer() const { return min_layer_; }
@@ -79,7 +83,7 @@ struct FrNet  // A Net is a set of connected MazePoints
   void reset(odb::dbNet* db_net,
              bool is_clock,
              int driver_idx,
-             int edge_cost,
+             int8_t edge_cost,
              int min_layer,
              int max_layer,
              float slack,
@@ -97,7 +101,7 @@ struct FrNet  // A Net is a set of connected MazePoints
   bool is_clock_;           // flag that indicates if net is a clock net
   bool is_critical_;
   int driver_idx_;
-  int edge_cost_;
+  int8_t edge_cost_;
   int min_layer_;
   int max_layer_;
   float slack_;

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

@@ -104,7 +104,7 @@ class FastRouteCore
                 bool is_clock,
                 bool is_local,
                 int driver_idx,
-                int cost,
+                int8_t cost,
                 int min_layer,
                 int max_layer,
                 float slack,

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

@@ -231,7 +231,7 @@ FrNet* FastRouteCore::addNet(odb::dbNet* db_net,
                              bool is_clock,
                              bool is_local,
                              int driver_idx,
-                             int cost,
+                             int8_t cost,
                              int min_layer,
                              int max_layer,
                              float slack,
@@ -1601,7 +1601,7 @@ void FrNet::addPin(int x, int y, int layer)
 void FrNet::reset(odb::dbNet* db_net,
                   bool is_clock,
                   int driver_idx,
-                  int edge_cost,
+                  int8_t edge_cost,
                   int min_layer,
                   int max_layer,
                   float slack,

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

@@ -718,21 +718,12 @@ void FastRouteCore::gen_brk_RSMT(const bool congestionDriven,
 
       if (x1 != x2 || y1 != y2) {  // the branch is not degraded (a point)
         // the position of this segment in seglist
-        seglist_[netID].push_back(Segment());
-        auto& seg = seglist_[netID].back();
+        const int8_t cost = nets_[netID]->getEdgeCost();
         if (x1 < x2) {
-          seg.x1 = x1;
-          seg.x2 = x2;
-          seg.y1 = y1;
-          seg.y2 = y2;
+          seglist_[netID].emplace_back(x1, y1, x2, y2, cost);
         } else {
-          seg.x1 = x2;
-          seg.x2 = x1;
-          seg.y1 = y2;
-          seg.y2 = y1;
+          seglist_[netID].emplace_back(x2, y2, x1, y1, cost);
         }
-
-        seg.cost = nets_[netID]->getEdgeCost();
       }
     }  // loop j