gpl: add PL_ROUTABILITY_OVERFLOW_THRESHOLD

Changelog.md

@@ -18,17 +18,32 @@
 
 ## Steps
 
+* `OpenROAD.GlobalPlacement`
+
+  * Exposed `-routability_check_overflow` argument as new variable
+    `PL_ROUTABILITY_OVERFLOW_THRESHOLD`.
+
 * `Yosys.*Synthesis`
-  * Created new variable `SYNTH_HIERARCHY_MODE`, replacing `SYNTH_NO_FLAT`. There are three options, `flatten`, `deferred_flatten` and `keep`. The first two correspond to `SYNTH_NO_FLAT` being false and true respectively. The third keeps the hierarchy in the final netlist.
-  * Created new variable `SYNTH_TIE_UNDEFINED` to customize whether undefined and undriven values are tied low, high, or left as-is.
-  * Created new variable `SYNTH_WRITE_NOATTR` to allow attributes to be propagated to the final netlist.
+
+  * Created new variable `SYNTH_HIERARCHY_MODE`, replacing `SYNTH_NO_FLAT`.
+    There are three options, `flatten`, `deferred_flatten` and `keep`. The first
+    two correspond to `SYNTH_NO_FLAT` being false and true respectively. The
+    third keeps the hierarchy in the final netlist.
+  * Created new variable `SYNTH_TIE_UNDEFINED` to customize whether undefined
+    and undriven values are tied low, high, or left as-is.
+  * Created new variable `SYNTH_WRITE_NOATTR` to allow attributes to be
+    propagated to the final netlist.
 
 * Created `Yosys.Resynthesis`
-  * Like `Yosys.Synthesis`, but uses the current input state netlist as an input instead of RTL files
+
+  * Like `Yosys.Synthesis`, but uses the current input state netlist as an input
+    instead of RTL files
 
 ## CLI
 
-* Added new option: `-e`/`--initial-state-element-override`: allows an element in the initial state to be overridden straight from the commandline. 
+* Added new option: `-e`/`--initial-state-element-override`: allows an element
+  in the initial state to be overridden straight from the commandline.
+
 # 2.2.9
 
 ## Steps

openlane/scripts/openroad/gpl.tcl

@@ -47,6 +47,9 @@ if { [info exists ::env(PL_ROUTABILITY_DRIVEN)] && $::env(PL_ROUTABILITY_DRIVEN)
 	set_macro_extension $::env(GRT_MACRO_EXTENSION)
 	source $::env(SCRIPTS_DIR)/openroad/common/set_layer_adjustments.tcl
 	lappend arg_list -routability_driven
+	if { [info exists ::env(PL_ROUTABILITY_OVERFLOW_THRESHOLD)] } {
+		lappend arg_list -routability_check_overflow $::env(PL_ROUTABILITY_OVERFLOW_THRESHOLD)
+	}
 }
 
 if { $::env(PL_SKIP_INITIAL_PLACEMENT) } {
@@ -72,6 +75,7 @@ lappend arg_list -pad_right $cell_pad_side
 lappend arg_list -pad_left $cell_pad_side
 lappend arg_list -init_wirelength_coef $::env(PL_WIRE_LENGTH_COEF)
 
+puts "+ global_placement $arg_list"
 global_placement {*}$arg_list
 
 

openlane/steps/openroad.py

@@ -1287,6 +1287,11 @@ class GlobalPlacement(_GlobalPlacement):
             "Specifies whether the placer should use routability driven placement.",
             default=True,
         ),
+        Variable(
+            "PL_ROUTABILITY_OVERFLOW_THRESHOLD",
+            Optional[Decimal],
+            "Sets overflow threshold for routability mode.",
+        ),
     ]