add MKL-DNN placement pass

This patch also refactors conv+bn (includes changes from PR
https://github.com/PaddlePaddle/Paddle/pull/13926)
updated to use the mkldnn-placement-pass.

test=develop

paddle/fluid/inference/api/analysis_predictor.cc

@@ -226,18 +226,21 @@ void AnalysisPredictor::OptimizeInferenceProgram() {
   argument_.origin_program_desc.reset(
       new ProgramDesc(*inference_program_->Proto()));
 
+  bool use_mkldnn = config_._use_mkldnn;
   switch (config_.ir_mode) {
     case contrib::AnalysisConfig::IrPassMode::kExclude:
       Analyzer()
           .IncludeAllIrPasses()
-          .SetUseMkldnn(config_._use_mkldnn)
-          .DisableIrPasses(config_.ir_passes)
+          .SetUseMkldnn(use_mkldnn)
+          .DisableIrPasses(use_mkldnn ? config_.ir_mkldnn_passes
+                                      : config_.ir_passes)
           .Run(&argument_);
       break;
     case contrib::AnalysisConfig::IrPassMode::kInclude:
       Analyzer()
-          .SetUseMkldnn(config_._use_mkldnn)
-          .IncludeIrPasses(config_.ir_passes)
+          .SetUseMkldnn(use_mkldnn)
+          .IncludeIrPasses(use_mkldnn ? config_.ir_mkldnn_passes
+                                      : config_.ir_passes)
           .Run(&argument_);
       break;
     default:

paddle/fluid/inference/api/paddle_inference_api.h

@@ -261,8 +261,8 @@ struct AnalysisConfig : public NativeConfig {
 
   void SetIncludeMode() {
     ir_mode = IrPassMode::kInclude;
-    // this pass has to be run at the beginning of all fuse passes
     ir_passes = {"infer_clean_graph_pass"};
+    ir_mkldnn_passes = {"infer_clean_graph_pass"};
   }
 
   // Determine whether to perform graph optimization.
@@ -271,6 +271,8 @@ struct AnalysisConfig : public NativeConfig {
   IrPassMode ir_mode{IrPassMode::kExclude};
   // passes to be excluded/included
   std::vector<std::string> ir_passes{"embedding_fc_lstm_fuse_pass"};
+  // passes to be excluded/included when MKL-DNN is enabled
+  std::vector<std::string> ir_mkldnn_passes{"embedding_fc_lstm_fuse_pass"};
 
   // NOT stable yet.
   bool use_feed_fetch_ops{true};