Only seperate input storage of mutable SharedVariable

theano/compile/function_module.py

@@ -590,7 +590,8 @@ class Function(object):
         # so that they have different storage as their value
         ins = [copy.copy(input) for input in maker.inputs]
         for in_cpy, in_ori in zip(ins, maker.inputs):
-            in_cpy.value = copy.deepcopy(in_ori.value)
+            if in_ori.mutable:
+                in_cpy.value = copy.deepcopy(in_ori.value)
 
         # Delete update output in fgraph and updates In instances if needed
         if delete_updates:
@@ -613,10 +614,10 @@ class Function(object):
         for out_ori, out_cpy in zip(maker.outputs, outs):
             out_cpy.borrow = out_ori.borrow
 
+        # Delete update if needed
         update_i = len(outs)
         for i, in_var in zip(ins, fg_cpy.inputs):
             i.variable = in_var
-            # Delete update if needed
             if not delete_updates and i.update is not None:
                 i.update = fg_cpy.outputs[update_i]
                 update_i += 1
@@ -634,7 +635,7 @@ class Function(object):
                     raise ValueError("SharedVariable: %s not found" %
                                      (sv.name))
 
-            # Swap SharedVariable in fgraph and ins
+            # Swap SharedVariable in fgraph and In instances
             for index, (i, in_v) in enumerate(zip(ins, fg_cpy.inputs)):
                 # Variables in maker.inputs are defined by user, therefore we
                 # use them to make comparision and do the mapping.
@@ -703,8 +704,9 @@ class Function(object):
             # Share immutable ShareVariable and constant input's storage
             swapped = swap is not None and in_ori.variable in swap_svs_ori
 
-            is_const = isinstance(in_ori.variable, theano.tensor.Constant)
-            if (is_const or not in_ori.mutable) and not swapped:
+            # Using the original storage if SharedVariable will not be updated
+            # and is not swapped
+            if not in_ori.mutable and not swapped:
                 cpy.data = ori.data
                 in_cpy.value = in_ori.value
 

theano/compile/tests/test_function_module.py

@@ -272,9 +272,7 @@ class T_function(unittest.TestCase):
             for (input, _1, _2), here, there in zip(ori.indices,
                                                     ori.input_storage,
                                                     cpy.input_storage):
-                if not input.mutable:
-                    self.assertTrue(here.data is there.data)
-                else:
+                if input.mutable:
                     self.assertFalse(here.data is there.data)
 
     def test_swap_SharedVariable(self):