dft: keep OpenROAD ordering when constraints set

Author: PrecisEDAnon

flow/scripts/dft_scan_pre_global_route.tcl

@@ -854,6 +854,15 @@ proc dft_scanopt_next_reorder {chain_cells_by_name {tag "pregrt"}} {
     return $chain_cells_by_name
   }
 
+  # scanopt_next is an external reorder step and does not currently interpret
+  # OpenROAD's scan-order constraints (groups/paths/fixed_edge/before/etc).
+  # If the user provided a constraints file, keep OpenROAD's ordering.
+  set constraints_file [dft_get_env DFT_SCAN_ORDER_CONSTRAINTS_FILE ""]
+  if { $constraints_file != "" } {
+    puts "DFT: WARNING: DFT_SCAN_SOLVER=scanopt_next ignores DFT_SCAN_ORDER_CONSTRAINTS_FILE; using OpenROAD order"
+    return $chain_cells_by_name
+  }
+
   set out_dir "/tmp"
   if { [info exists ::env(REPORTS_DIR)] && $::env(REPORTS_DIR) != "" } {
     set out_dir $::env(REPORTS_DIR)

flow/util/scan_chain_plot_openroad.py

@@ -69,12 +69,25 @@ def _inst_xy(inst) -> Tuple[int, int]:
 
 
 def _bterm_xy(bterm) -> Tuple[int, int]:
+    if hasattr(bterm, "getFirstPinLocation"):
+        try:
+            ok, x, y = bterm.getFirstPinLocation()
+            if ok:
+                return int(x), int(y)
+        except Exception:
+            pass
     return _bbox_center_xy(bterm.getBBox())
 
 
 def _iterm_xy(iterm) -> Tuple[int, int]:
-    bbox = iterm.getBBox()
-    return int(bbox.xMin()), int(bbox.yMin())
+    if hasattr(iterm, "getAvgXY"):
+        try:
+            ok, x, y = iterm.getAvgXY()
+            if ok:
+                return int(x), int(y)
+        except Exception:
+            pass
+    return _bbox_center_xy(iterm.getBBox())
 
 
 def _node_id(kind: str, name: str) -> str: