modify strigs

lite/kernels/mlu/bridges/graph.h

@@ -100,7 +100,7 @@ class Graph {
   }
   void GenOfflineModel(const std::string& name) {
     cnmlModel_t model;
-    std::string filename = name + ".offline.cambricon";
+    const auto& filename = name + ".offline.cambricon";
     CNML_CALL(cnmlCreateModel(&model, name.c_str()));
     CNML_CALL(cnmlAddFusionOpToModel(model, fusion_op_, filename.c_str()));
     CNML_CALL(cnmlSaveModel(model, filename.c_str()));

lite/kernels/mlu/subgraph_compute.h

@@ -164,13 +164,13 @@ class SubgraphEngine : public subgraph::Engine {
     return status;
   }
 
-  std::string TrimStrings(std::string origin_str) {
+  std::string TrimStrings(const std::string& origin_str) {
     std::string str = origin_str;
     std::size_t found = str.find("0x");
     std::size_t found_end = 0;
-    std::vector<std::string> del_strs = {
+    const std::vector<std::string> del_strs = {
         "/trans_io_copy", "/trans_cast", "/trans_layout"};
-    for (auto iterm : del_strs) {
+    for (const auto& iterm : del_strs) {
       found_end = str.find(iterm);
       // trim point address and one of the del_strs
       if (found != std::string::npos && found_end != std::string::npos) {
@@ -186,24 +186,26 @@ class SubgraphEngine : public subgraph::Engine {
   std::string GetOfflineModName() {
     sort(input_names_.begin(), input_names_.end());
     sort(output_names_.begin(), output_names_.end());
+    const auto& delimiter = "__";
+    const auto& delimiter_num = "_";
+    const auto& input_shape_str = "input_shape_";
+    const auto& output_shape_str = "output_shape_";
     std::string name = "";
-    std::string delimiter = "__";
-    std::string delimiter_num = "_";
     std::string tmp = "";
-    for (auto input_name : input_names_) {
+    for (const auto& input_name : input_names_) {
       tmp = input_name;
-      name += TrimStrings(tmp) + delimiter + "input_shape_";
+      name += TrimStrings(tmp) + delimiter + input_shape_str;
       auto input_tensor = scope_->FindMutableTensor(input_name);
-      for (auto iterm : input_tensor->dims().Vectorize()) {
+      for (const auto& iterm : input_tensor->dims().Vectorize()) {
         name += std::to_string(iterm) + delimiter_num;
       }
       name += delimiter;
     }
-    for (auto output_name : output_names_) {
+    for (const auto& output_name : output_names_) {
       tmp = output_name;
-      name += TrimStrings(tmp) + delimiter + "output_shape_";
+      name += TrimStrings(tmp) + delimiter + output_shape_str;
       auto output_tensor = scope_->FindMutableTensor(output_name);
-      for (auto iterm : output_tensor->dims().Vectorize()) {
+      for (const auto& iterm : output_tensor->dims().Vectorize()) {
         name += std::to_string(iterm) + delimiter_num;
       }
       name += delimiter;