Remove useless user warning.

theano/sandbox/cuda/opt.py

@@ -648,6 +648,10 @@ def local_gpu_careduce(node):
         if isinstance(node.op.scalar_op, (scal.Add, scal.Mul,
                                           scal.Maximum, scal.Minimum)):
             x, = node.inputs
+            # Otherwise, is some corner case, we will try to move it
+            # to the GPU later and this cause not wanted user warning.
+            if x.dtype != 'float32':
+                return
             replace = False
             if x.owner and isinstance(x.owner.op, HostFromGpu):
                 replace = True
@@ -665,7 +669,7 @@ def local_gpu_careduce(node):
                 # don't introduce a bigger transfer. It is hard to
                 # know if after all optimization we will do the bigger
                 # transfer or not. I'm guessing an heuristic to find
-                # that. I suppose that if the input of the recution is
+                # that. I suppose that if the input of the reduction is
                 # generated by an op that we can in some cases move to
                 # the GPU, that we will move it. If some CPU ops are
                 # supported only in some cases on the GPU, this will