fix test_parallel_executor_transformer

python/paddle/fluid/tests/unittests/test_parallel_executor_transformer.py

@@ -20,6 +20,7 @@ import numpy as np
 from parallel_executor_test_base import TestParallelExecutorBase
 import unittest
 import paddle
+import paddle.fluid.core as core
 import paddle.dataset.wmt16 as wmt16
 import os
 
@@ -170,6 +171,7 @@ class TestTransformer(TestParallelExecutorBase):
                 writer.complete_append_tensor()
 
     def test_main(self):
+        if core.is_compiled_with_cuda():
             self.check_network_convergence(transformer, use_cuda=True)
         self.check_network_convergence(transformer, use_cuda=False, iter=5)