Faster opt local_fill_cut

theano/tensor/opt.py

@@ -2559,12 +2559,12 @@ def local_fill_cut(node):
     # scalars, but we can't ignore the large matrix because it gives
     # the shape of the result.
 
-    if not opt.check_chain(node, T.Elemwise):
+    if node.op != T.Elemwise:
         return False
 
     output = node.outputs[0]
     try:
-        #reference is some input with the same type as the input but
+        #reference is some input with the same type as the output but
         #that is not produced by a fill
         reference = [input
                      for input in node.inputs
@@ -2574,16 +2574,18 @@ def local_fill_cut(node):
         return False
 
     new_inputs = []
+    new = False
     for input in node.inputs:
-        if opt.check_chain(input, T.fill):
+        if input.owner and input.owner.op == T.fill:
             model, filling = input.owner.inputs
             if encompasses_broadcastable(reference.type.broadcastable,
                                          filling.type.broadcastable):
                 new_inputs.append(filling)
+                new = True
                 continue
         new_inputs.append(input)
 
-    if new_inputs == node.inputs:
+    if not new:
         return False
 
     rval = node.op(*new_inputs)