【opt fix】change the optimized_model name of opt (#2892)

lite/api/cxx_api.cc

@@ -43,6 +43,7 @@ void Predictor::SaveModel(const std::string &dir,
       LOG(FATAL) << "Unknown model type";
   }
   if (record_info) {
+    MkDirRecur(dir);
     SaveOpKernelInfo(dir);
   }
 }

lite/core/mir/subgraph/subgraph_pass_test.cc

@@ -203,7 +203,7 @@ TEST(Subgraph, generate_model_and_check_precision) {
                                  valid_places,
                                  input_tensor_shape,
                                  input_tensor_type,
-                                 FLAGS_optimized_model_dir + "/ref_opt_model");
+                                 FLAGS_optimized_model_dir + "_ref_opt_model");
 // Generate and run optimized model on NPU/XPU as the target predictor
 #ifdef LITE_WITH_NPU
   valid_places.push_back(lite_api::Place{TARGET(kNPU), PRECISION(kFloat)});
@@ -217,7 +217,7 @@ TEST(Subgraph, generate_model_and_check_precision) {
                                  valid_places,
                                  input_tensor_shape,
                                  input_tensor_type,
-                                 FLAGS_optimized_model_dir + "/tar_opt_model");
+                                 FLAGS_optimized_model_dir + "_tar_opt_model");
   // Check the difference of the output tensors between reference predictor and
   // target predictor
   CheckOutputTensors(tar_predictor, ref_predictor, output_tensor_type);

lite/model_parser/model_parser.cc

@@ -544,7 +544,6 @@ void SaveModelNaive(const std::string &model_dir,
                     const Scope &exec_scope,
                     const cpp::ProgramDesc &cpp_prog,
                     bool combined) {
-  MkDirRecur(model_dir);
   // Save program
   const std::string prog_path = model_dir + ".nb";
   naive_buffer::BinaryTable table;
@@ -586,7 +585,8 @@ void SaveModelNaive(const std::string &model_dir,
   // Save Params
   SaveCombinedParamsNaive(prog_path, exec_scope, cpp_prog);
 
-  LOG(INFO) << "Save naive buffer model in '" << model_dir << "' successfully";
+  LOG(INFO) << "Save naive buffer model in '" << model_dir
+            << ".nb' successfully";
 }
 #endif