Fix duplicate paths for timing checks

compiler/base/graph_util.py

@@ -10,8 +10,9 @@ from vector import vector
 from pin_layout import pin_layout
     
 class timing_graph():
-    """Implements a directed graph
-       Nodes are currently just Strings.
+    """
+    Implements a directed graph
+    Nodes are currently just Strings.
     """
     
     def __init__(self):
@@ -20,30 +21,34 @@ class timing_graph():
 
     def add_edge(self, src_node, dest_node):
         """Adds edge to graph. Nodes added as well if they do not exist."""
+        
         src_node = src_node.lower()
         dest_node = dest_node.lower()
         self.graph[src_node].add(dest_node)
 
     def add_node(self, node):
         """Add node to graph with no edges"""
+        
         node = node.lower()
         if not node in self.graph:
             self.graph[node] = set()
             
     def remove_edges(self, node):
+        
         """Helper function to remove edges, useful for removing vdd/gnd"""
         node = node.lower()
         self.graph[node] = set()    
             
-    def get_all_paths(self, src_node, dest_node, rmv_rail_nodes=True): 
+    def get_all_paths(self, src_node, dest_node, remove_rail_nodes=True, reduce_paths=True): 
         """Traverse all paths from source to destination"""
+        
         src_node = src_node.lower()
         dest_node = dest_node.lower()
         
-        #Remove vdd and gnd by default
-        #Will require edits if separate supplies are implemented.
-        if rmv_rail_nodes:
-            #Names are also assumed.
+        # Remove vdd and gnd by default
+        # Will require edits if separate supplies are implemented.
+        if remove_rail_nodes:
+            # Names are also assumed.
             self.remove_edges('vdd')
             self.remove_edges('gnd')
         
@@ -57,11 +62,20 @@ class timing_graph():
         # Call the recursive helper function to print all paths 
         self.get_all_paths_util(src_node, dest_node, visited, path)     
         debug.info(2, "Paths found={}".format(len(self.all_paths)))
-            
+
+        if reduce_paths:
+            self.reduce_paths()
+        
         return self.all_paths     
+
+    def reduce_paths(self):
+        """ Remove any path that is a subset of another path """
+        
+        self.all_paths = [p1 for p1 in self.all_paths if not any(set(p1)<=set(p2) for p2 in self.all_paths if p1 is not p2)]
             
     def get_all_paths_util(self, cur_node, dest_node, visited, path): 
         """Recursive function to find all paths in a Depth First Search manner"""
+        
         # Mark the current node as visited and store in path 
         visited.add(cur_node)
         path.append(cur_node) 
@@ -72,7 +86,7 @@ class timing_graph():
             self.all_paths.append(copy.deepcopy(path))
         else: 
             # If current vertex is not destination 
-            #Recur for all the vertices adjacent to this vertex 
+            # Recur for all the vertices adjacent to this vertex 
             for node in self.graph[cur_node]: 
                 if node not in visited: 
                     self.get_all_paths_util(node, dest_node, visited, path) 
@@ -83,4 +97,5 @@ class timing_graph():
             
     def __str__(self):
         """ override print function output """
-        return "Nodes: {}\nEdges:{} ".format(list(self.graph), self.graph)  
+
+        return "Nodes: {}\nEdges:{} ".format(list(self.graph), self.graph)