Add new snap_to_grid function for graph router

compiler/router/graph.py

@@ -12,6 +12,7 @@ from openram.tech import drc
 from .direction import direction
 from .graph_node import graph_node
 from .graph_probe import graph_probe
+from .graph_utils import snap_to_grid
 
 
 class graph:
@@ -87,7 +88,7 @@ class graph:
                     offset = self.router.offset
                     p = node.center
                     lengths = [blockage.width(), blockage.height()]
-                    centers = blockage.center().snap_to_grid()
+                    centers = snap_to_grid(blockage.center())
                     ll, ur = blockage.rect
                     safe = [True, True]
                     for i in range(2):
@@ -111,7 +112,7 @@ class graph:
 
         for via in self.graph_vias:
             ll, ur = via.rect
-            center = via.center().snap_to_grid()
+            center = snap_to_grid(via.center())
             if via.on_segment(ll, point, ur) and \
                (center.x != point.x or center.y != point.y):
                 return True
@@ -187,7 +188,7 @@ class graph:
             else: # Square-like pin
                 points = [shape.center()]
             for p in points:
-                p.snap_to_grid()
+                p = snap_to_grid(p)
                 x_values.add(p.x)
                 y_values.add(p.y)
 

compiler/router/graph_shape.py

@@ -6,6 +6,7 @@
 from openram.base.pin_layout import pin_layout
 from openram.base.vector import vector
 from openram.tech import drc
+from .graph_utils import snap_to_grid
 
 
 class graph_shape(pin_layout):
@@ -18,6 +19,9 @@ class graph_shape(pin_layout):
 
         pin_layout.__init__(self, name, rect, layer_name_pp)
 
+        # Snap the shape to the grid here
+        ll, ur = self.rect
+        self.rect = [snap_to_grid(ll), snap_to_grid(ur)]
         self.inflated_from = inflated_from
 
 

compiler/router/graph_utils.py

@@ -0,0 +1,25 @@
+# See LICENSE for licensing information.
+#
+# Copyright (c) 2016-2023 Regents of the University of California, Santa Cruz
+# All rights reserved.
+#
+"""
+Utility functions for graph router.
+"""
+from openram.base import vector
+from openram.tech import drc
+
+
+def snap_to_grid(v):
+    """ Use custom `snap_to_grid` since `vector.snap_to_grid` isn't working. """
+
+    return vector(snap_offset_to_grid(v.x), snap_offset_to_grid(v.y))
+
+
+def snap_offset_to_grid(offset):
+    """
+    Use custom `snap_offset_to_grid` since `vector.snap_offset_to_grid` isn't
+    working.
+    """
+
+    return round(offset, len(str(drc["grid"]).split('.')[1]))