use 1.8paddle log_softmax (#350)

Author: baiyfbupt

paddleslim/dist/dml.py

@@ -18,7 +18,6 @@
 
 import copy
 import paddle.fluid as fluid
-import paddle.nn.functional as F
 
 
 class DML(fluid.dygraph.Layer):
@@ -70,7 +69,7 @@ def kl_loss(self, logits):
             cur_kl_loss = 0
             for j in range(self.model_num):
                 if i != j:
-                    x = F.log_softmax(logits[i], axis=1)
+                    x = fluid.layers.log_softmax(logits[i], axis=1)
                     y = fluid.layers.softmax(logits[j], axis=1)
                     cur_kl_loss += fluid.layers.kldiv_loss(
                         x, y, reduction='batchmean')