removed duplicate into when fusing Elemwise and GpuElemwise.

theano/tensor/opt.py

@@ -2315,7 +2315,13 @@ def local_elemwise_fusion_op(OP):
                 #if the scalar_op don't have a c implementation, we skip its fusion to allow the fusion of the other ops.
                 do_fusion=True
                 try:
-                    s_input = [scalar.Scalar(x.dtype).make_variable() for x in i.owner.inputs]
+                    s_input = []
+                    for ii in i.owner.inputs:
+                        if ii in inputs:
+                            s_input.append(s_inputs[inputs.index(ii)])
+                        else:
+                            s_input.append(scalar.Scalar(ii.dtype).make_variable())
+                    #s_input = [scalar.Scalar(x.dtype).make_variable() for x in i.owner.inputs]
                     s_op=i.owner.op.scalar_op(*s_input)
                     i.owner.op.scalar_op.c_code(s_op.owner,"test_presence_of_c_code",
                                                 ["x" for x in i.owner.inputs],
@@ -2334,8 +2340,11 @@ def local_elemwise_fusion_op(OP):
                 s_inputs.extend(s_input)
                 s_g.append(s_op)
             else:
+                if i in inputs:
+                    s=s_inputs[inputs.index(i)]
+                else:
+                    s=scalar.Scalar(i.dtype).make_variable()
                 inputs.append(i)
-                s=scalar.Scalar(i.dtype).make_variable()
                 s_inputs.append(s)
                 s_g.append(s)
 
@@ -2344,6 +2353,21 @@ def local_elemwise_fusion_op(OP):
     #        print "local_elemwise_fusion: no elemwise in inputs. Nothing to fuse."
             return False
 
+        #remove duplicate inputs, we most keep the order.
+        inputs2=[]
+        s_inputs2=[]
+        for i,si in zip(inputs,s_inputs):
+            if i not in inputs2:
+                inputs2.append(i)
+                s_inputs2.append(si)
+            else:
+                assert si in s_inputs2
+        inputs = inputs2
+        s_inputs = s_inputs2
+        del inputs2, s_inputs2
+        assert len(s_inputs)==len(inputs)
+        
+
         otype = node.outputs[0].type
         s_new_out=node.op.scalar_op(*s_g)
         try: