making optimization compatible with old version

theano/sandbox/multinomial.py

@@ -377,7 +377,11 @@ class GpuMultinomialFromUniform(MultinomialFromUniform, GpuOp):
 @local_optimizer([MultinomialFromUniform])
 def local_gpu_multinomial(node):
     if type(node.op) is MultinomialFromUniform:
-        p, u, n_samples = node.inputs
+        if len(node.inputs) == 2:
+            p, u = node.inputs
+            n_samples = 1
+        else:
+            p, u, n_samples = node.inputs
         try:
             if get_scalar_constant_value(n_samples) != 1:
                 return None
@@ -395,7 +399,11 @@ def local_gpu_multinomial(node):
             node.inputs[0].owner and
             type(node.inputs[0].owner.op) is MultinomialFromUniform):
         multi = node.inputs[0].owner
-        p, u, n_samples = multi.inputs
+        if len(node.inputs) == 2:
+            p, u = node.inputs
+            n_samples = 1
+        else:
+            p, u, n_samples = node.inputs
         try:
             if get_scalar_constant_value(n_samples) != 1:
                 return None