fix gpt N4C32 dp script bug (#3392)

tests/test_tipc/benchmark_train.sh

@@ -1,4 +1,19 @@
 #!/bin/bash
+
+# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#     http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 source test_tipc/common_func.sh
 
 # run benchmark sh 
@@ -67,6 +82,12 @@ function set_gpu_id(){
     echo $seq
 }
 
+function get_world_size(){
+    IFS="C"
+    arr=($1) 
+    echo ${arr[1]}
+}
+
 function get_repo_name(){
     IFS=";"
     cur_dir=$(pwd)
@@ -202,10 +223,10 @@ for batch_size in ${batch_size_list[*]}; do
 
             # NOTE: Only for GPT for now.
             if [[ ${model_name} =~ gpt* ]]; then
-                num_gpu_devices=$[(${#gpu_id}+1)/2]
+                num_gpu_devices=`get_world_size $device_num`
                 sed_norm_train=$norm_train
 
-                global_batch_size=$[$batch_size*$num_gpu_devices]
+                global_batch_size=$(($batch_size*$num_gpu_devices))
                 extra_params="--global_batch_size=$global_batch_size --dp_degree=$num_gpu_devices"
                 sed_norm_train="$sed_norm_train $extra_params"