makefile: fix post global route error propagation in bazel-orfs

The Makefile should just handle dependencies, no flow logic.

Consistency here reduces surprises when updating and
reasoning about the code.

Signed-off-by: Øyvind Harboe <[email protected]>

Author: oharboe

flow/Makefile

@@ -853,13 +853,7 @@ $(eval $(call do-step,5_1_grt,$(RESULTS_DIR)/4_cts.odb $(FASTROUTE_TCL) $(PRE_GL
 #-------------------------------------------------------------------------------
 $(eval $(call do-step,5_2_route,$(RESULTS_DIR)/5_1_grt.odb,detail_route))
 
-# SEP 3: Filler cell insertion
-# ------------------------------------------------------------------------------
-ifeq ($(FILL_CELLS),)
-$(eval $(call do-copy,5_3_fillcell,5_2_route.odb))
-else
 $(eval $(call do-step,5_3_fillcell,$(RESULTS_DIR)/5_2_route.odb,fillcell))
-endif
 
 $(eval $(call do-copy,5_route,5_3_fillcell.odb))
 

flow/scripts/fillcell.tcl

@@ -7,9 +7,11 @@ if {[expr [file exists $::env(REPORTS_DIR)/congestion.rpt] && \
 source $::env(SCRIPTS_DIR)/load.tcl
 load_design 5_2_route.odb 4_cts.sdc
 
-set_propagated_clock [all_clocks]
+if {[env_var_exists_and_non_empty FILL_CELLS]} {
+  set_propagated_clock [all_clocks]
 
-filler_placement $::env(FILL_CELLS)
-check_placement
+  filler_placement $::env(FILL_CELLS)
+  check_placement
+}
 
 write_db $::env(RESULTS_DIR)/5_3_fillcell.odb