validate post GRT WNS opto

docs/user/FlowVariables.md

@@ -196,6 +196,7 @@ configuration file.
 | <a name="MIN_ROUTING_LAYER"></a>MIN_ROUTING_LAYER| The lowest metal layer name to be used in routing.| |
 | <a name="NUM_CORES"></a>NUM_CORES| Passed to `openroad -threads $(NUM_CORES)`, defaults to numbers of cores in system as determined by system specific code in Makefile, `nproc` is tried first. OpenROAD does not limit itself to this number of cores across OpenROAD running instances, which can lead to overprovisioning in contexts such as bazel-orfs where there could be many routing, or place jobs running at the same time.| |
 | <a name="OPENROAD_HIERARCHICAL"></a>OPENROAD_HIERARCHICAL| Feature toggle to enable to run OpenROAD in hierarchical mode, otherwise considered flat. Will eventually be the default and this option will be retired.| 0|
+| <a name="OPT_POST_GRT_WNS"></a>OPT_POST_GRT_WNS| Optimize WNS after global routing by additional repair_timing that uses VT swap and wire rerouting only to minimize placement and routing disturbance| 1|
 | <a name="OR_K"></a>OR_K| Passed as -or_k to detailed routing.| |
 | <a name="OR_SEED"></a>OR_SEED| Passed as -or_seed to detailed routing.| |
 | <a name="PDN_TCL"></a>PDN_TCL| File path which has a set of power grid policies used by pdn to be applied to the design, such as layers to use, stripe width and spacing to generate the actual metal straps.| |
@@ -543,6 +544,7 @@ configuration file.
 - [MAX_REPAIR_TIMING_ITER](#MAX_REPAIR_TIMING_ITER)
 - [MAX_ROUTING_LAYER](#MAX_ROUTING_LAYER)
 - [MIN_ROUTING_LAYER](#MIN_ROUTING_LAYER)
+- [OPT_POST_GRT_WNS](#OPT_POST_GRT_WNS)
 - [POST_GLOBAL_ROUTE_TCL](#POST_GLOBAL_ROUTE_TCL)
 - [PRE_GLOBAL_ROUTE_TCL](#PRE_GLOBAL_ROUTE_TCL)
 - [REPORT_CLOCK_SKEW](#REPORT_CLOCK_SKEW)

flow/scripts/global_route.tcl

@@ -87,6 +87,29 @@ proc global_route_helper { } {
       report_metrics 5 "global route post repair timing"
     }
 
+    if { $::env(OPT_POST_GRT_WNS) } {
+      log_cmd global_route -start_incremental
+      log_cmd detailed_placement {*}$dpl_args
+      check_placement -verbose
+      # Route only the modified net by DPL
+      log_cmd global_route -end_incremental {*}$res_aware \
+        -congestion_report_file $::env(REPORTS_DIR)/congestion_post_repair_timing_opt_wns.rpt
+
+      set repair_timing_args \
+        [list -setup -sequence "vt_swap reroute" -skip_last_gasp -repair_tns 0 -verbose]
+      if { [env_var_exists_and_non_empty MATCH_CELL_FOOTPRINT] } {
+        lappend repair_timing_args -match_cell_footprint
+      }
+      if { $::env(SETUP_SLACK_MARGIN) != 0 } {
+        lappend repair_timing_args -setup_margin $::env(SETUP_SLACK_MARGIN)
+      }
+      repair_timing {*}$repair_timing_args
+
+      if { $::env(DETAILED_METRICS) } {
+        report_metrics 5 "global route post repair timing_opt_wns"
+      }
+    }
+
     # Running DPL to fix overlapped instances
     # Run to get modified net by DPL
     log_cmd global_route -start_incremental
@@ -97,12 +120,13 @@ proc global_route_helper { } {
       -congestion_report_file $::env(REPORTS_DIR)/congestion_post_repair_timing.rpt
   }
 
-
-  log_cmd global_route -start_incremental
-  recover_power_helper
-  # Route the modified nets by rsz journal restore
-  log_cmd global_route -end_incremental {*}$res_aware \
-    -congestion_report_file $::env(REPORTS_DIR)/congestion_post_recover_power.rpt
+  if { !$::env(OPT_POST_GRT_WNS) } {
+    log_cmd global_route -start_incremental
+    recover_power_helper
+    # Route the modified nets by rsz journal restore
+    log_cmd global_route -end_incremental {*}$res_aware \
+      -congestion_report_file $::env(REPORTS_DIR)/congestion_post_recover_power.rpt
+  }
 
   if {
     !$::env(SKIP_ANTENNA_REPAIR) &&

flow/scripts/variables.mk

@@ -221,6 +221,8 @@ ifeq ($(origin ABC_CLOCK_PERIOD_IN_PS), undefined)
    endif
 endif
 
+export OPT_POST_GRT_WNS ?= 1
+
 .PHONY: vars
 vars:
 	mkdir -p $(OBJECTS_DIR)

flow/scripts/variables.yaml

@@ -1617,3 +1617,10 @@ CDL_FILE:
     for generating Circuit Description Language output.
   stages:
     - final
+OPT_POST_GRT_WNS:
+  default: 1
+  description: >
+    Optimize WNS after global routing by additional repair_timing that uses
+    VT swap and wire rerouting only to minimize placement and routing disturbance
+  stages:
+    - grt