diff --git a/src/bin/maple b/src/bin/maple
index d8cfc18687a19a788873fcf4d8b67b9b4c3ad940..f606b801c06e3e79d4c028b25039f7715b14f755 100755
Binary files a/src/bin/maple and b/src/bin/maple differ
diff --git a/src/deplibs/libmaple_driverutil.a b/src/deplibs/libmaple_driverutil.a
index 9a8ffaffed92a2b1d5414269c44d4bf59ad6f8a3..0a278241b4db6475765c4e598589657560f1a085 100644
Binary files a/src/deplibs/libmaple_driverutil.a and b/src/deplibs/libmaple_driverutil.a differ
diff --git a/src/deplibs/libmplutil.a b/src/deplibs/libmplutil.a
index 69e550ebcc6ca29d0ac1d5b705cbef4f4362e71f..246d81511572a66a579ca70128df051a0944fff5 100644
Binary files a/src/deplibs/libmplutil.a and b/src/deplibs/libmplutil.a differ
diff --git a/src/mpl2mpl/include/vtable_analysis.h b/src/mpl2mpl/include/vtable_analysis.h
index 075bf7f34cfbee9351680d12f368279a2d04afec..811a3a9280c3d69ec8d619b7a49a328ed93ecf44 100644
--- a/src/mpl2mpl/include/vtable_analysis.h
+++ b/src/mpl2mpl/include/vtable_analysis.h
@@ -31,13 +31,13 @@ class VtableAnalysis : public FuncOptimizeImpl {
   VtableAnalysis(MIRModule *mod, KlassHierarchy *kh, bool dump);
   ~VtableAnalysis() = default;
   static std::string DecodeBaseNameWithType(const MIRFunction &func);
+  static bool IsVtableCandidate(const MIRFunction &func);
   void ProcessFunc(MIRFunction *func) override;
   FuncOptimizeImpl *Clone() override {
     return new VtableAnalysis(*this);
   }
 
  private:
-  bool IsVtableCandidate(const MIRFunction &func) const;
   bool CheckOverrideForCrossPackage(const MIRFunction &baseMethod, const MIRFunction &currMethod) const;
   void AddMethodToTable(MethodPtrVector &methodTable, MethodPair &methodPair);
   void GenVtableList(const Klass &klass);
diff --git a/src/mpl2mpl/src/reflection_analysis.cpp b/src/mpl2mpl/src/reflection_analysis.cpp
index 8df81da752a254cf5c61c4d92c20e59b68fce54b..b90d3b635d0f60355fa0fb186f48f8ceb5a8d26a 100644
--- a/src/mpl2mpl/src/reflection_analysis.cpp
+++ b/src/mpl2mpl/src/reflection_analysis.cpp
@@ -35,6 +35,7 @@ constexpr uint64 kMethodNotVirtual = 0x00000001;
 constexpr uint64 kMethodFinalize = 0x00000002;
 constexpr uint64 kMethodAbstract = 0x00000010;
 constexpr uint64 kFieldOffsetIspOffset = 0x00000001;
+constexpr int32 kMethodNotFound = -10;
 
 constexpr int kModPublic = 1;                 // 0x00000001
 constexpr int kModPrivate = 2;                // 0x00000002
@@ -621,7 +622,7 @@ uint32 ReflectionAnalysis::GetMethodInVtabIndex(const Klass &klass, const MIRFun
     }
   }
   if (!findMethod) {
-    constexpr int notFoundMethod = -10;
+    constexpr int notFoundMethod = kMethodNotFound;
     methodInVtabIndex = notFoundMethod;
   }
   // Check VtabIndex, int16.
diff --git a/src/mpl2mpl/src/vtable_analysis.cpp b/src/mpl2mpl/src/vtable_analysis.cpp
index 5fb5cefd038eb7572a2aeb1394b0f875ac200e21..277eef1a6b46dfacc0cc064f456e373012b93759 100644
--- a/src/mpl2mpl/src/vtable_analysis.cpp
+++ b/src/mpl2mpl/src/vtable_analysis.cpp
@@ -51,7 +51,7 @@ VtableAnalysis::VtableAnalysis(MIRModule *mod, KlassHierarchy *kh, bool dump) :
   }
 }
 
-bool VtableAnalysis::IsVtableCandidate(const MIRFunction &func) const {
+bool VtableAnalysis::IsVtableCandidate(const MIRFunction &func) {
   return func.GetAttr(FUNCATTR_virtual) && !func.GetAttr(FUNCATTR_private) && !func.GetAttr(FUNCATTR_static);
 }
 
@@ -107,10 +107,10 @@ void VtableAnalysis::GenVtableList(const Klass &klass) {
     }
   } else {  // it's a class
     MIRClassType *curType = klass.GetMIRClassType();
-    Klass *superKlass = klass.GetSuperKlass();
     // prepare vtable_methods
     // first is vtable from parents. since it's single inheritance, we copy it directly
-    if (superKlass != nullptr) {
+    if (klass.HasSuperKlass()) {
+      Klass *superKlass = klass.GetSuperKlass();
       MIRStructType *partenType = superKlass->GetMIRStructType();
       curType->GetVTableMethods() = partenType->GetVTableMethods();
     }