constant folding optimization can create TensorConstants

theano/tensor/opt.py

@@ -1038,7 +1038,12 @@ def constant_folding(node):
             return False
     storage = [[None] for output in node.outputs]
     node.op.perform(node, [x.data for x in node.inputs], storage)
-    return [gof.Constant(output.type, s[0]) for s, output in zip(storage, node.outputs)]
+    cls = gof.Constant
+    if isinstance(output.type, T.Tensor):
+        #TODO: think about how to extend to more types
+        cls = T.TensorConstant
+
+    return [cls(output.type, s[0]) for s, output in zip(storage, node.outputs)]
 
 register_canonicalize(constant_folding)
 register_specialize(constant_folding)