Make get_scalar_constant_value bypass DeepCopyOp and OutputGuard

theano/tensor/basic.py

@@ -519,7 +519,6 @@ def get_scalar_constant_value(v):
     if isinstance(v, numpy.ndarray):
         return numpy_scalar(v)
 
-
     if isinstance(v, Constant):
         if getattr(v.tag, 'unique_value', None) is not None:
             data = v.tag.unique_value
@@ -528,11 +527,9 @@ def get_scalar_constant_value(v):
         return numpy_scalar(data)
 
     if v.owner:
-        if isinstance(v.owner.op, Alloc):
-            return get_scalar_constant_value(v.owner.inputs[0])
-        if isinstance(v.owner.op, DimShuffle):
-            return get_scalar_constant_value(v.owner.inputs[0])
-        if isinstance(v.owner.op, Rebroadcast):
+        if isinstance(v.owner.op, (Alloc, DimShuffle, Rebroadcast,
+                                   compile.ops.OutputGuard,
+                                   compile.DeepCopyOp)):
             return get_scalar_constant_value(v.owner.inputs[0])
         if isinstance(v.owner.op, Elemwise) and \
                 isinstance(v.owner.op.scalar_op, scal.Second):