--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnsafeCastNode.java	Tue Apr 29 19:30:38 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnsafeCastNode.java	Wed Apr 30 19:38:24 2014 +0200
@@ -60,21 +60,30 @@
     }
 
     @Override
-    public boolean inferStamp() {
-        if (stamp() instanceof ObjectStamp && object.stamp() instanceof ObjectStamp) {
-            return updateStamp(((ObjectStamp) object.stamp()).castTo((ObjectStamp) stamp()));
-        }
-        return updateStamp(object.stamp().join(stamp()));
-    }
-
-    @Override
     public Node canonical(CanonicalizerTool tool) {
         assert getKind() == Kind.Object && object.getKind() == Kind.Object;
-        if (stamp().equals(object.stamp())) {
-            return object;
-        } else {
+
+        ObjectStamp my = (ObjectStamp) stamp();
+        ObjectStamp other = (ObjectStamp) object.stamp();
+
+        if (my.type() == null || other.type() == null) {
+            return this;
+        }
+        if (my.isExactType() && !other.isExactType()) {
             return this;
         }
+        if (my.nonNull() && !other.nonNull()) {
+            return this;
+        }
+        if (!my.type().isAssignableFrom(other.type())) {
+            return this;
+        }
+        /*
+         * The unsafe cast does not add any new type information, so it can be removed. Note that
+         * this means that the unsafe cast cannot be used to "drop" type information (in which case
+         * it must not be canonicalized in any case).
+         */
+        return object;
     }
 
     @Override