--- a/mercurial/filelog.py
+++ b/mercurial/filelog.py
@@ -73,18 +73,7 @@ class filelog(revlog):
             t2 = self.read(node)
             return t2 == text
 
-        p1, p2 = self.parents(node)
-        h = hash(text, p1, p2)
-
-        return h != node
-
-    def makenode(self, node, text):
-        """calculate a file nodeid for text, descended or possibly
-        unchanged from node"""
-
-        if self.cmp(node, text):
-            return hash(text, node, nullid)
-        return node
+        return revlog.cmp(self, node, text)
 
     def annotate(self, node):