Fix CTC lifter optimization

theano/gpuarray/opt.py

@@ -2280,13 +2280,14 @@ def local_gpu_magma_svd(op, context_name, inputs, outputs):
             out = [out.astype('float16')]
     return out
 
-@register_opt('fast_compile')
+@register_opt('ctc', 'fast_compile')
 @op_lifter([theano.tensor.nnet.ctc.ConnectionistTemporalClassification])
-@register_opt2([theano.tensor.nnet.ctc.ConnectionistTemporalClassification], 'fast_compile')
+@register_opt2([theano.tensor.nnet.ctc.ConnectionistTemporalClassification], 'ctc', 'fast_compile')
 def local_gpu_ctc(op, context_name, inputs, outputs):
     if not config.ctc.enabled:
         return
-    return [GpuConnectionistTemporalClassification()(*node.inputs)]
+    op = GpuConnectionistTemporalClassification(compute_grad=op.compute_grad)
+    return list(op(*inputs))
 
 # Do not register in fast_run or fast_compile.
 # It will be added to fast_run if the GPU is enabled.