Update loss.py

python/paddle/nn/functional/loss.py

@@ -1653,12 +1653,16 @@ def cross_entropy(input,
         if soft_label == False:
             valid_label = paddle.where(label == ignore_index,
                                        paddle.zeros_like(label), label)
+            # TODO: Temporarily use paddle.nonzero instead of paddle.max 
+            # to detect and find out possible illegal label values
             if len(paddle.nonzero(valid_label < 0)) > 0:
                 invalid_label = paddle.gather_nd(
                     valid_label, paddle.nonzero(valid_label < 0))
                 raise ValueError(
                     "Target({}) is out of class_dimension's lower bound({})".
                     format(invalid_label[0], 0))
+            # TODO: Temporarily use paddle.nonzero instead of paddle.max 
+            # to detect and find out possible illegal label values
             if len(paddle.nonzero(valid_label >= input.shape[-1])) > 0:
                 invalid_label = paddle.gather_nd(
                     valid_label, paddle.nonzero(valid_label >= input.shape[-1]))