• 版本、环境信息：
     1）PaddlePaddle版本：1.6.1
     2）CPU：CPU
     3）GPU：无
     4）系统环境：Ubuntu16.04，python2.7.15

• 复现信息：如为报错，请给出复现环境、复现步骤
  复现代码：

        import paddle
        import paddle.fluid as fluid
        place = fluid.CPUPlace()
        main = fluid.Program()
        with fluid.program_guard(main):
            x = fluid.data(name='x', shape=[None, 13], dtype='float64')
            y = fluid.data(name='y', shape=[None, 1], dtype='float64')
            y_predict = fluid.layers.fc(input=x, size=1, act=None)
            cost = fluid.layers.square_error_cost(input=y_predict, label=y)
            avg_cost = fluid.layers.mean(cost)
  
            adam_optimizer = fluid.optimizer.AdamOptimizer(0.01)
            adam_optimizer.minimize(avg_cost)
  
            fetch_list = [avg_cost]
            train_reader = paddle.batch(
                paddle.dataset.uci_housing.train(), batch_size=1)
            feeder = fluid.DataFeeder(place=place, feed_list=[x, y])
            exe = fluid.Executor(place)
            exe.run(fluid.default_startup_program())
            for data in train_reader():
                exe.run(main, feed=feeder.feed(data), fetch_list=fetch_list)
  

报错信息：

x, y输入类型改为float32不报错。
x = fluid.data(name='x', shape=[None, 13], dtype='float32')
y = fluid.data(name='y', shape=[None, 1], dtype='float32')