!7491 modify transformer's floordiv and mod to adapt to 310

Merge pull request !7491 from yuchaojie/transformer

model_zoo/official/nlp/transformer/src/beam_search.py

@@ -168,6 +168,11 @@ class BeamSearchDecoder(nn.Cell):
         self.concat = P.Concat(axis=-1)
         self.gather_nd = P.GatherNd()
 
+        self.greater_equal = P.GreaterEqual()
+        self.sub = P.Sub()
+        self.cast = P.Cast()
+        self.zeroslike = P.ZerosLike()
+
         # init inputs and states
         self.start_ids = Tensor(np.full([batch_size * beam_width, 1], sos_id), mstype.int32)
         self.init_seq = Tensor(np.full([batch_size, beam_width, 1], sos_id), mstype.int32)
@@ -199,8 +204,19 @@ class BeamSearchDecoder(nn.Cell):
         topk_scores, topk_indices = self.topk(flat_scores, self.beam_width)
 
         # convert to beam and word indices
-        beam_indices = self.floor_div(topk_indices, self.vocab_size_tensor)
-        word_indices = self.mod(topk_indices, self.vocab_size_tensor)
+        #beam_indices = self.floor_div(topk_indices, self.vocab_size_tensor)
+        #word_indices = self.mod(topk_indices, self.vocab_size_tensor)
+        #======================================================================
+        #replace floor_div and mod op, since these two ops only support fp16 on
+        #Ascend310, which will cause overflow.
+        temp = topk_indices
+        beam_indices = self.zeroslike(topk_indices)
+        for _ in range(self.beam_width - 1):
+            temp = self.sub(temp, self.vocab_size_tensor)
+            res = self.cast(self.greater_equal(temp, 0), mstype.int32)
+            beam_indices = beam_indices + res
+        word_indices = topk_indices - beam_indices * self.vocab_size_tensor
+        #======================================================================
 
         # mask finished indices
         beam_indices = self.select(state_finished, self.beam_ids, beam_indices)