Merge pull request The-OpenROAD-Project#9500 from The-OpenROAD-Project-staging/grt-infinite-resources

grt: infinite resources for testing purpose

Author: eder-matheus

src/grt/README.md

@@ -31,6 +31,7 @@ global_route
     [-end_incremental]
     [-use_cugr]
     [-resistance_aware]
+    [-infinite_cap]
 ```
 
 #### Options
@@ -50,6 +51,7 @@ global_route
 | `-end_incremental` | This flag run incremental GRT with the nets modified. The default is false. |
 | `-use_cugr` | This flag run GRT using CUGR as the router solver. NOTE: this is not ready for production. |
 | `-resistance_aware` | This flag enables resistance-aware layer assignment and 3D routing. NOTE: this is not ready for production. |
+| `-infinite_cap` | Enables "infinite" gcell capacity for testing purpose. NOTE: this is not recommended for production flows. |
 
 ### Set Routing Layers
 

src/grt/include/grt/GlobalRouter.h

@@ -160,6 +160,8 @@ class GlobalRouter
     skip_large_fanout_ = skip_large_fanout;
   };
 
+  void setInfiniteCapacity(bool infinite_capacity);
+
   // flow functions
   void readGuides(const char* file_name);
   void loadGuidesFromDB();
@@ -513,7 +515,7 @@ class GlobalRouter
   std::vector<RoutingTracks> routing_tracks_;
 
   // Flow variables
-  bool is_incremental_;
+  bool infinite_capacity_;
   float adjustment_;
   int congestion_iterations_{50};
   int congestion_report_iter_step_;
@@ -563,6 +565,7 @@ class GlobalRouter
 
   // incremental grt
   GRouteDbCbk* grouter_cbk_;
+  bool is_incremental_;
 
   friend class IncrementalGRoute;
   friend class GRouteDbCbk;

src/grt/src/GlobalRouter.cpp

@@ -82,7 +82,7 @@ GlobalRouter::GlobalRouter(utl::Logger* logger,
       grid_origin_(0, 0),
       groute_renderer_(nullptr),
       grid_(new Grid),
-      is_incremental_(false),
+      infinite_capacity_(false),
       adjustment_(0.0),
       congestion_report_iter_step_(0),
       allow_congestion_(false),
@@ -101,7 +101,8 @@ GlobalRouter::GlobalRouter(utl::Logger* logger,
       heatmap_(nullptr),
       heatmap_rudy_(nullptr),
       congestion_file_name_(nullptr),
-      grouter_cbk_(nullptr)
+      grouter_cbk_(nullptr),
+      is_incremental_(false)
 {
   fastroute_
       = new FastRouteCore(db_, logger_, callback_handler_, stt_builder_, sta_);
@@ -734,6 +735,8 @@ void GlobalRouter::setCapacities(int min_routing_layer, int max_routing_layer)
   fastroute_->initEdges();
   int x_grids = grid_->getXGrids();
   int y_grids = grid_->getYGrids();
+  const int kBigInt = std::numeric_limits<int>::max();
+  const int16_t kBigCap = std::numeric_limits<int16_t>::max() / 10;
 
   for (int layer = 1; layer <= grid_->getNumLayers(); layer++) {
     odb::dbTechLayer* tech_layer = db_->getTech()->findRoutingLayer(layer);
@@ -748,44 +751,49 @@ void GlobalRouter::setCapacities(int min_routing_layer, int max_routing_layer)
         = tech_layer->getDirection() == odb::dbTechLayerDir::HORIZONTAL;
 
     if (tech_layer->getDirection() == odb::dbTechLayerDir::HORIZONTAL) {
-      int min_cap = std::numeric_limits<int>::max();
+      int min_cap = kBigInt;
       for (int y = 1; y <= y_grids; y++) {
         for (int x = 1; x < x_grids; x++) {
-          const int cap = inside_layer_range ? computeGCellCapacity(x - 1,
-                                                                    y - 1,
-                                                                    track_init,
-                                                                    track_pitch,
-                                                                    track_count,
-                                                                    horizontal)
-                                             : 0;
+          int cap = 0;
+          if (infinite_capacity_) {
+            cap = kBigCap;
+          } else if (inside_layer_range) {
+            cap = computeGCellCapacity(
+                x - 1, y - 1, track_init, track_pitch, track_count, horizontal);
+          }
           min_cap = std::min(min_cap, cap);
           fastroute_->setEdgeCapacity(x - 1, y - 1, x, y - 1, layer, cap);
         }
       }
-      min_cap = min_cap == std::numeric_limits<int>::max() ? 0 : min_cap;
+      min_cap = min_cap == kBigInt ? 0 : min_cap;
       fastroute_->addHCapacity(min_cap, layer);
     } else {
-      int min_cap = std::numeric_limits<int>::max();
+      int min_cap = kBigInt;
       for (int x = 1; x <= x_grids; x++) {
         for (int y = 1; y < y_grids; y++) {
-          const int cap = inside_layer_range ? computeGCellCapacity(x - 1,
-                                                                    y - 1,
-                                                                    track_init,
-                                                                    track_pitch,
-                                                                    track_count,
-                                                                    horizontal)
-                                             : 0;
+          int cap = 0;
+          if (infinite_capacity_) {
+            cap = kBigCap;
+          } else if (inside_layer_range) {
+            cap = computeGCellCapacity(
+                x - 1, y - 1, track_init, track_pitch, track_count, horizontal);
+          }
           min_cap = std::min(min_cap, cap);
           fastroute_->setEdgeCapacity(x - 1, y - 1, x - 1, y, layer, cap);
         }
       }
-      min_cap = min_cap == std::numeric_limits<int>::max() ? 0 : min_cap;
+      min_cap = min_cap == kBigInt ? 0 : min_cap;
       fastroute_->addVCapacity(min_cap, layer);
     }
   }
   fastroute_->initLowerBoundCapacities();
 }
 
+void GlobalRouter::setInfiniteCapacity(bool infinite_capacity)
+{
+  infinite_capacity_ = infinite_capacity;
+}
+
 int GlobalRouter::computeGCellCapacity(const int x,
                                        const int y,
                                        const int track_init,

src/grt/src/GlobalRouter.i

@@ -152,6 +152,12 @@ set_skip_large_fanout(int skip_large_fanout)
   getGlobalRouter()->setSkipLargeFanoutNets(skip_large_fanout);
 }
 
+void
+set_infinite_cap(bool infinite_capacity)
+{
+  getGlobalRouter()->setInfiniteCapacity(infinite_capacity);
+}
+
 void start_incremental()
 {
   getGlobalRouter()->startIncremental();

src/grt/src/GlobalRouter.tcl

@@ -152,7 +152,8 @@ sta::define_cmd_args "global_route" {[-guide_file out_file] \
                                   [-start_incremental] \
                                   [-end_incremental] \
                                   [-use_cugr] \
-                                  [-resistance_aware]
+                                  [-resistance_aware] \
+                                  [-infinite_cap]
 }
 
 proc global_route { args } {
@@ -161,8 +162,8 @@ proc global_route { args } {
           -grid_origin -critical_nets_percentage -congestion_report_iter_step\
           -skip_large_fanout_nets
          } \
-    flags {-allow_congestion -resistance_aware -verbose -start_incremental -end_incremental \
-          -use_cugr}
+    flags {-allow_congestion -resistance_aware -infinite_cap -verbose -start_incremental \
+          -end_incremental -use_cugr}
 
   sta::check_argc_eq0 "global_route" $args
 
@@ -228,6 +229,9 @@ proc global_route { args } {
   set resistance_aware [info exists flags(-resistance_aware)]
   grt::set_resistance_aware $resistance_aware
 
+  set infinite_cap [info exists flags(-infinite_cap)]
+  grt::set_infinite_cap $infinite_cap
+
   set start_incremental [info exists flags(-start_incremental)]
   set end_incremental [info exists flags(-end_incremental)]
 

src/grt/test/BUILD

@@ -32,6 +32,7 @@ TESTS = [
     "gcd_cugr",
     "gcd_flute",
     "increase_capacity1",
+    "infinite_cap",
     "inst_pin_out_of_die",
     "invalid_pin_placement",
     "invalid_routing_layer",

src/grt/test/CMakeLists.txt

@@ -30,6 +30,7 @@ or_integration_tests(
     gcd_cugr
     gcd_flute
     increase_capacity1
+    infinite_cap
     inst_pin_out_of_die
     invalid_pin_placement
     invalid_routing_layer

src/grt/test/infinite_cap.ok

@@ -0,0 +1,65 @@
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0128] Design: gcd
+[INFO ODB-0130]     Created 54 pins.
+[INFO ODB-0131]     Created 676 components and 2850 component-terminals.
+[INFO ODB-0133]     Created 579 nets and 1498 connections.
+[INFO GRT-0020] Min routing layer: metal2
+[INFO GRT-0021] Max routing layer: metal10
+[INFO GRT-0022] Global adjustment: 0%
+[INFO GRT-0023] Grid origin: (0, 0)
+[INFO GRT-0088] Layer metal1  Track-Pitch = 0.1400  line-2-Via Pitch: 0.1350
+[INFO GRT-0088] Layer metal2  Track-Pitch = 0.1900  line-2-Via Pitch: 0.1400
+[INFO GRT-0088] Layer metal3  Track-Pitch = 0.1400  line-2-Via Pitch: 0.1400
+[INFO GRT-0088] Layer metal4  Track-Pitch = 0.2800  line-2-Via Pitch: 0.2800
+[INFO GRT-0088] Layer metal5  Track-Pitch = 0.2800  line-2-Via Pitch: 0.2800
+[INFO GRT-0088] Layer metal6  Track-Pitch = 0.2800  line-2-Via Pitch: 0.2800
+[INFO GRT-0088] Layer metal7  Track-Pitch = 0.8000  line-2-Via Pitch: 0.8000
+[INFO GRT-0088] Layer metal8  Track-Pitch = 0.8000  line-2-Via Pitch: 0.8000
+[INFO GRT-0088] Layer metal9  Track-Pitch = 1.6000  line-2-Via Pitch: 1.6000
+[INFO GRT-0088] Layer metal10 Track-Pitch = 1.6000  line-2-Via Pitch: 1.6000
+[INFO GRT-0003] Macros: 0
+[INFO GRT-0004] Blockages: 0
+[INFO GRT-0019] Found 0 clock nets.
+[INFO GRT-0001] Minimum degree: 2
+[INFO GRT-0002] Maximum degree: 36
+
+[INFO GRT-0053] Routing resources analysis:
+          Routing      Original      Derated      Resource
+Layer     Direction    Resources     Resources    Reduction (%)
+---------------------------------------------------------------
+metal1     Horizontal    3898440       3898440          0.00%
+metal2     Vertical      3898440       3898440          0.00%
+metal3     Horizontal    3898440       3898440          0.00%
+metal4     Vertical      3898440       3898440          0.00%
+metal5     Horizontal    3898440       3898440          0.00%
+metal6     Vertical      3898440       3898440          0.00%
+metal7     Horizontal    3898440       3898440          0.00%
+metal8     Vertical      3898440       3898440          0.00%
+metal9     Horizontal    3898440       3898440          0.00%
+metal10    Vertical      3898440       3898440          0.00%
+---------------------------------------------------------------
+
+[INFO GRT-0197] Via related to pin nodes: 2686
+[INFO GRT-0198] Via related Steiner nodes: 44
+[INFO GRT-0199] Via filling finished.
+[INFO GRT-0111] Final number of vias: 3505
+[INFO GRT-0112] Final usage 3D: 13039
+
+[INFO GRT-0096] Final congestion report:
+Layer         Resource        Demand        Usage (%)    Max H / Max V / Total Overflow
+---------------------------------------------------------------------------------------
+metal1         3898440             0            0.00%             0 /  0 /  0
+metal2         3898440          1172            0.03%             0 /  0 /  0
+metal3         3898440          1212            0.03%             0 /  0 /  0
+metal4         3898440            41            0.00%             0 /  0 /  0
+metal5         3898440            51            0.00%             0 /  0 /  0
+metal6         3898440            48            0.00%             0 /  0 /  0
+metal7         3898440             0            0.00%             0 /  0 /  0
+metal8         3898440             0            0.00%             0 /  0 /  0
+metal9         3898440             0            0.00%             0 /  0 /  0
+metal10        3898440             0            0.00%             0 /  0 /  0
+---------------------------------------------------------------------------------------
+Total         38984400          2524            0.01%             0 /  0 /  0
+
+[INFO GRT-0018] Total wirelength: 10767 um
+[INFO GRT-0014] Routed nets: 563

src/grt/test/infinite_cap.tcl

@@ -0,0 +1,8 @@
+source "helpers.tcl"
+read_lef "Nangate45/Nangate45.lef"
+read_liberty Nangate45/Nangate45_typ.lib
+read_def "gcd.def"
+
+set_routing_layers -signal metal2-metal10
+
+global_route -infinite_cap -verbose