Merge pull request #10748 from The-OpenROAD-Project-staging/grt-res-aware-percentage

GRT: resistance-aware nets percentage TCL parameter

Author: eder-matheus

src/grt/README.md

@@ -32,6 +32,7 @@ global_route
     [-end_incremental]
     [-use_cugr]
     [-resistance_aware]
+    [-res_aware_nets_percentage percent]
     [-infinite_cap]
 ```
 
@@ -52,6 +53,7 @@ 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. |
+| `-res_aware_nets_percentage` | Set the percentage of resistance-aware nets (e.g. `-res_aware_nets_percentage 100` (for 100%)). The default value is `15` with resistance-aware enabled and `0` otherwise, and the allowed values are floats between `[0, 100]`. |
 | `-infinite_cap` | Enables "infinite" gcell capacity for testing purpose. NOTE: this is not recommended for production flows. |
 | `-snapshot_batched_width` | Set the semantic width of snapshot-batched routing (max batches per wave). The default is `0`, preserving the non-batched behavior. Set a positive integer to enable batched routing; allowed values are integers `[1, MAX_INT]`. Execution width still follows `set_thread_count`. NOTE: this is not recommended for production flows; it is intended for exploration and research projects. |
 

src/grt/include/grt/GlobalRouter.h

@@ -154,6 +154,7 @@ class GlobalRouter
   void setGridOrigin(int x, int y);
   void setAllowCongestion(bool allow_congestion);
   void setResistanceAware(bool resistance_aware);
+  void setResAwareNetsPercentage(float percentage);
   void setSnapshotBatchedWidth(int snapshot_batched_width);
   int getSnapshotBatchedWidth() const;
   int getSnapshotBatchCount() const;

src/grt/src/GlobalRouter.cpp

@@ -2431,6 +2431,23 @@ void GlobalRouter::setResistanceAware(bool resistance_aware)
   fastroute_->setResistanceAware(resistance_aware);
 }
 
+void GlobalRouter::setResAwareNetsPercentage(float percentage)
+{
+  if (!resistance_aware_) {
+    percentage = 0;
+    logger_->warn(GRT,
+                  308,
+                  "Resistance-aware routing is not enabled, setting res-aware "
+                  "nets percentage to 0.");
+  }
+  if (use_cugr_) {
+    // TODO
+    // cugr_->setResAwareNetsPercentage(percentage);
+  } else {
+    fastroute_->setResAwareNetsPercentage(percentage);
+  }
+}
+
 void GlobalRouter::setMacroExtension(int macro_extension)
 {
   macro_extension_ = macro_extension;

src/grt/src/GlobalRouter.i

@@ -110,6 +110,12 @@ set_resistance_aware(bool resistance_aware)
   getGlobalRouter()->setResistanceAware(resistance_aware);
 }
 
+void
+set_res_aware_nets_percentage(float percentage)
+{
+  getGlobalRouter()->setResAwareNetsPercentage(percentage);
+}
+
 void
 set_snapshot_batched_width(int snapshot_batched_width)
 {

src/grt/src/GlobalRouter.tcl

@@ -146,6 +146,7 @@ sta::define_cmd_args "global_route" {[-guide_file out_file] \
                                   [-congestion_report_iter_step steps] \
                                   [-grid_origin origin] \
                                   [-critical_nets_percentage percent] \
+                                  [-res_aware_nets_percentage percent] \
                                   [-skip_large_fanout_nets fanout] \
                                   [-allow_congestion] \
                                   [-snapshot_batched_width width] \
@@ -160,7 +161,8 @@ sta::define_cmd_args "global_route" {[-guide_file out_file] \
 proc global_route { args } {
   sta::parse_key_args "global_route" args \
     keys {-guide_file -congestion_iterations -congestion_report_file \
-          -grid_origin -critical_nets_percentage -congestion_report_iter_step \
+          -grid_origin -critical_nets_percentage -res_aware_nets_percentage \
+          -congestion_report_iter_step \
           -skip_large_fanout_nets -snapshot_batched_width
          } \
     flags {-allow_congestion -resistance_aware -infinite_cap -verbose -start_incremental \
@@ -243,6 +245,12 @@ proc global_route { args } {
   set resistance_aware [info exists flags(-resistance_aware)]
   grt::set_resistance_aware $resistance_aware
 
+  if { [info exists keys(-res_aware_nets_percentage)] } {
+    set res_aware_percentage $keys(-res_aware_nets_percentage)
+    sta::check_percent "-res_aware_nets_percentage" $res_aware_percentage
+    grt::set_res_aware_nets_percentage $res_aware_percentage
+  }
+
   if { [info exists keys(-snapshot_batched_width)] } {
     set snapshot_batched_width $keys(-snapshot_batched_width)
     sta::check_positive_integer "-snapshot_batched_width" \

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

@@ -242,6 +242,8 @@ class FastRouteCore
   void setVerbose(bool v);
   void setCriticalNetsPercentage(float u);
   float getCriticalNetsPercentage() { return critical_nets_percentage_; };
+  void setResAwareNetsPercentage(float percentage);
+  float getResAwareNetsPercentage() { return res_aware_nets_percentage_; };
   void setOverflowIterations(int iterations);
   void setCongestionReportIterStep(int congestion_report_iter_step);
   void setCongestionReportFile(const char* congestion_file_name);
@@ -329,7 +331,7 @@ class FastRouteCore
   double dbuToMicrons(int dbu);
   odb::Rect globalRoutingToBox(const GSegment& route);
   NetRouteMap getRoutes();
-  void updateSlacks(float percentage = 0.15);
+  void updateSlacks();
   void preProcessTechLayers();
   odb::dbTechLayer* getTechLayer(int layer, bool is_via);
 
@@ -778,6 +780,7 @@ class FastRouteCore
   int grid_hv_;
   bool verbose_;
   float critical_nets_percentage_;
+  float res_aware_nets_percentage_ = 15;
   int via_cost_;
   int mazeedge_threshold_;
   float v_capacity_lb_;

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

@@ -2776,6 +2776,11 @@ void FastRouteCore::setCriticalNetsPercentage(float u)
   critical_nets_percentage_ = u;
 }
 
+void FastRouteCore::setResAwareNetsPercentage(float percentage)
+{
+  res_aware_nets_percentage_ = percentage;
+}
+
 void FastRouteCore::setOverflowIterations(int iterations)
 {
   overflow_iterations_ = iterations;

src/grt/src/fastroute/src/utility.cpp

@@ -671,7 +671,7 @@ void FastRouteCore::setIncrementalGrt(bool is_incremental)
 
 // Update and sort the critical nets. Finally pick a percentage of the
 // nets to use the resistance-aware strategy
-void FastRouteCore::updateSlacks(float percentage)
+void FastRouteCore::updateSlacks()
 {
   // Check if liberty file was loaded before calculating slack
   if (sta_->getDbNetwork()->defaultLibertyLibrary() == nullptr
@@ -737,6 +737,8 @@ void FastRouteCore::updateSlacks(float percentage)
 
   std::ranges::stable_sort(res_aware_list, compareSlack);
 
+  float percentage = res_aware_nets_percentage_ / 100.0;
+
   // During incremental grt, enable res-aware for all nets in the list
   if (is_incremental_grt_) {
     percentage = 1;

src/grt/test/BUILD

@@ -96,6 +96,7 @@ TESTS = [
     "report_wire_length6",
     "report_wire_length7",
     "report_wire_length8",
+    "res_aware_nets_percentage",
     "set_nets_to_route1",
     "silence",
     "single_row",

src/grt/test/CMakeLists.txt

@@ -93,6 +93,7 @@ or_integration_tests(
     report_wire_length6
     report_wire_length7
     report_wire_length8
+    res_aware_nets_percentage
     set_nets_to_route1
     silence
     single_row