Optimize the execution of RuntimeProgram by saving the bool whether the op is...

Optimize the execution of RuntimeProgram by saving the bool whether the op is feed/fetch op. (#2703)

test=develop

lite/core/program.cc

@@ -137,8 +137,7 @@ void RuntimeProgram::UpdateVarsOfProgram(cpp::ProgramDesc* desc) {
 
 void RuntimeProgram::Run() {
   for (auto& inst : instructions_) {
-    std::string op_type = inst.op()->op_info()->Type();
-    if (op_type == "feed" || op_type == "fetch") continue;
+    if (inst.is_feed_fetch_op()) continue;
     inst.Run();
 #ifdef LITE_WITH_PROFILE
 #ifdef LITE_WITH_PRECISION_PROFILE

lite/core/program.h

@@ -90,7 +90,12 @@ struct Program {
 struct Instruction {
   Instruction(const std::shared_ptr<OpLite>& op,
               std::unique_ptr<KernelBase>&& kernel)
-      : op_(op), kernel_(std::move(kernel)) {}
+      : op_(op), kernel_(std::move(kernel)) {
+    std::string op_type = op->Type();
+    if (op_type == "feed" || op_type == "fetch") {
+      is_feed_fetch_op_ = true;
+    }
+  }
 
   // Run the instruction.
   void Run();
@@ -101,6 +106,8 @@ struct Instruction {
   const KernelBase* kernel() const { return kernel_.get(); }
   KernelBase* mutable_kernel() { return kernel_.get(); }
 
+  bool is_feed_fetch_op() const { return is_feed_fetch_op_; }
+
 #ifdef LITE_WITH_PROFILE
   void set_profiler(profile::Profiler* profiler) {
     profiler_ = profiler;
@@ -118,6 +125,7 @@ struct Instruction {
  private:
   std::shared_ptr<OpLite> op_;
   std::unique_ptr<KernelBase> kernel_;
+  bool is_feed_fetch_op_{false};
   bool first_epoch_{true};
   bool has_run_{false};