Make local_elemwise_fusion_op more flexible.

theano/tensor/opt.py

@@ -5258,7 +5258,8 @@ for i in xrange(1,len(p64)): print i, 64[i]-p64[i-1]
 # ###############
 # # Loop fusion #
 # ###############
-def local_elemwise_fusion_op(OP, max_input_fct=lambda node: 1024):
+def local_elemwise_fusion_op(OP, max_input_fct=lambda node: 1024,
+                             maker=None):
     """
     We parametrize it to make it work for Elemwise and GpuElemwise op.
 
@@ -5277,6 +5278,9 @@ def local_elemwise_fusion_op(OP, max_input_fct=lambda node: 1024):
                           enough that if we hit it, I'm not sure it
                           will affect performance.
     """
+    if maker is None:
+        def maker(node, scalar_op):
+            return OP(scalar_op)
     def local_fuse(node):
         """
         As part of specialization, we fuse two consecutive elemwise Ops of the
@@ -5458,7 +5462,7 @@ your code will run correctly, but may be slower.""")
 
         # create the new node.
         # Do not call make_node to have test_value
-        n = OP(C)(*inputs).owner
+        n = maker(node, C)(*inputs).owner
         assert len(n.outputs) == 1
         assert node.outputs[0].dtype == n.outputs[0].dtype