diff --git a/src/mapleall/maple_me/include/lfo_dep_test.h b/src/mapleall/maple_me/include/lfo_dep_test.h
index 2d1ee8db305d0e78d7b4d2a67a7aaa63ddf7e4e5..245388fa6fef0c1cb4171009916e58ebc5142ce4 100644
--- a/src/mapleall/maple_me/include/lfo_dep_test.h
+++ b/src/mapleall/maple_me/include/lfo_dep_test.h
@@ -94,6 +94,7 @@ class DoloopInfo {
         redVars(alloc->Adapter()) {}
   ~DoloopInfo() = default;
   bool IsLoopInvariant(MeExpr *x);
+  bool IsLoopInvariant2(BaseNode *x);
   bool OnlyInvariantScalars(MeExpr *x);
   SubscriptDesc *BuildOneSubscriptDesc(BaseNode *subsX);
   ArrayAccessDesc *BuildOneArrayAccessDesc(ArrayNode *arr, BaseNode *parent);
diff --git a/src/mapleall/maple_me/include/lfo_pre_emit.h b/src/mapleall/maple_me/include/lfo_pre_emit.h
index 6ae76ba942ff99515f42370792b1f80a926e6e93..5184b012f5ecee9f39e5b0af1a9ff85a6d4aa333 100644
--- a/src/mapleall/maple_me/include/lfo_pre_emit.h
+++ b/src/mapleall/maple_me/include/lfo_pre_emit.h
@@ -88,7 +88,11 @@ class LfoPreEmitter : public AnalysisResult {
     return nullptr;
   }
   MeExpr *GetMexpr(BaseNode *node) {
-    LfoPart *lfopart = lfoExprParts[node];
+    MapleMap<BaseNode *, LfoPart *>::iterator it = lfoExprParts.find(node);
+    if (it == lfoExprParts.end()) {
+      return nullptr;
+    }
+    LfoPart *lfopart = it->second;
     return lfopart->meexpr;
   }
   MeStmt *GetMeStmt(uint32_t stmtID) {
diff --git a/src/mapleall/maple_me/src/lfo_dep_test.cpp b/src/mapleall/maple_me/src/lfo_dep_test.cpp
index 64444e879c89b3bdea455cfc35d74909a410a78b..3c7c1b8e2ae0a31904781d1fbedfff0c30ac8d79 100644
--- a/src/mapleall/maple_me/src/lfo_dep_test.cpp
+++ b/src/mapleall/maple_me/src/lfo_dep_test.cpp
@@ -128,6 +128,20 @@ bool DoloopInfo::IsLoopInvariant(MeExpr *x) {
   return false;
 }
 
+// check if x is loop-invariant w.r.t. the doloop
+bool DoloopInfo::IsLoopInvariant2(BaseNode *x) {
+  MeExpr *meExpr = depInfo->preEmit->GetMexpr(x);
+  if (meExpr != nullptr) {
+    return IsLoopInvariant(meExpr);
+  }
+  for (size_t i = 0; i < x->NumOpnds(); i++) {
+    if (!IsLoopInvariant2(x->Opnd(i))) {
+      return false;
+    }
+  }
+  return true;
+}
+
 // check if all the scalars contained in x are loop-invariant unless it is IV
 bool DoloopInfo::OnlyInvariantScalars(MeExpr *x) {
   if (x == nullptr) {
@@ -182,7 +196,7 @@ bool DoloopInfo::OnlyInvariantScalars(MeExpr *x) {
 SubscriptDesc *DoloopInfo::BuildOneSubscriptDesc(BaseNode *subsX) {
   MeExpr *meExpr = depInfo->preEmit->GetMexpr(subsX);
   SubscriptDesc *subsDesc = alloc->GetMemPool()->New<SubscriptDesc>(meExpr);
-  if (IsLoopInvariant(meExpr)) {
+  if (IsLoopInvariant2(subsX)) {
     subsDesc->loopInvariant = true;
     return subsDesc;
   }
@@ -259,15 +273,15 @@ ArrayAccessDesc *DoloopInfo::BuildOneArrayAccessDesc(ArrayNode *arr, BaseNode *p
   size_t dim = arryty->GetDim();
   CHECK_FATAL(dim >= arr->NumOpnds() - 1, "BuildOneArrayAccessDesc: inconsistent array dimension");
   // ensure array base is loop invariant
-  OpMeExpr *arrayMeExpr = static_cast<OpMeExpr *>(depInfo->preEmit->GetMexpr(arr));
-  if (!IsLoopInvariant(arrayMeExpr->GetOpnd(0))) {
+  if (!IsLoopInvariant2(arr->Opnd(0))) {
     hasPtrAccess = true;
     return nullptr;
   }
   // determine arryOst
   IvarMeExpr *ivarMeExpr = nullptr;
   OriginalSt *arryOst = nullptr;
-  if (arrayMeExpr->GetOp() == OP_add) {  // the array is converted from add
+  OpMeExpr *arrayMeExpr = static_cast<OpMeExpr *>(depInfo->preEmit->GetMexpr(arr));
+  if (arrayMeExpr == nullptr || arrayMeExpr->GetOp() == OP_add) {  // the array is converted from add
   } else if (parent->op == OP_iread) {
     ivarMeExpr = static_cast<IvarMeExpr *>(depInfo->preEmit->GetMexpr(parent));
     CHECK_FATAL(ivarMeExpr->GetMu() != nullptr, "BuildOneArrayAccessDesc: no mu corresponding to iread");
@@ -304,7 +318,7 @@ ArrayAccessDesc *DoloopInfo::BuildOneArrayAccessDesc(ArrayNode *arr, BaseNode *p
 void DoloopInfo::CreateRHSArrayAccessDesc(BaseNode *x, BaseNode *parent) {
   if (x->GetOpCode() == OP_array) {
     if (parent->GetOpCode() != OP_iread) { // skip arrays not underneath iread unless loop-invariant
-      if (IsLoopInvariant(depInfo->preEmit->GetMexpr(x))) {
+      if (IsLoopInvariant2(x)) {
         return;
       }
       hasPtrAccess = true;
diff --git a/src/mapleall/maple_me/src/lfo_loop_vec.cpp b/src/mapleall/maple_me/src/lfo_loop_vec.cpp
index 96559906528572dbd4321dfd99dddba68a307d12..1c445ab0e6651e211eb95d8bce6ad94fbf0990b0 100644
--- a/src/mapleall/maple_me/src/lfo_loop_vec.cpp
+++ b/src/mapleall/maple_me/src/lfo_loop_vec.cpp
@@ -792,10 +792,8 @@ bool LoopVectorization::ExprVectorizable(DoloopInfo *doloopInfo, LoopVecInfo* ve
     case OP_cmpg:
     case OP_cmpl: {
       // check two operands are constant
-      MeExpr *r0MeExpr = (*lfoExprParts)[x->Opnd(0)]->GetMeExpr();
-      MeExpr *r1MeExpr = (*lfoExprParts)[x->Opnd(1)]->GetMeExpr();
-      bool r0Uniform = doloopInfo->IsLoopInvariant(r0MeExpr);
-      bool r1Uniform = doloopInfo->IsLoopInvariant(r1MeExpr);
+      bool r0Uniform = doloopInfo->IsLoopInvariant2(x->Opnd(0));
+      bool r1Uniform = doloopInfo->IsLoopInvariant2(x->Opnd(1));
       if (r0Uniform && r1Uniform) {
         vecInfo->uniformNodes.insert(x->Opnd(0));
         vecInfo->uniformNodes.insert(x->Opnd(1));
@@ -814,8 +812,7 @@ bool LoopVectorization::ExprVectorizable(DoloopInfo *doloopInfo, LoopVecInfo* ve
     case OP_lnot:
     case OP_neg:
     case OP_abs: {
-      MeExpr *r0MeExpr = (*lfoExprParts)[x->Opnd(0)]->GetMeExpr();
-      bool r0Uniform = doloopInfo->IsLoopInvariant(r0MeExpr);
+      bool r0Uniform = doloopInfo->IsLoopInvariant2(x->Opnd(0));
       if (r0Uniform) {
         vecInfo->uniformNodes.insert(x->Opnd(0));
         return true;
@@ -835,8 +832,7 @@ bool LoopVectorization::ExprVectorizable(DoloopInfo *doloopInfo, LoopVecInfo* ve
           IreadNode *iread = static_cast<IreadNode *>(x);
           if ((iread->GetFieldID() != 0 || MustBeAddress(iread->GetPrimType())) &&
               iread->Opnd(0)->GetOpCode() == OP_array) {
-            MeExpr *meExpr = depInfo->preEmit->GetLfoExprPart(iread->Opnd(0))->GetMeExpr();
-            canVec = doloopInfo->IsLoopInvariant(meExpr);
+            canVec = doloopInfo->IsLoopInvariant2(iread->Opnd(0));
           }
         }
       }
@@ -945,8 +941,7 @@ bool LoopVectorization::Vectorizable(DoloopInfo *doloopInfo, LoopVecInfo* vecInf
         bool canVec = ExprVectorizable(doloopInfo, vecInfo, iassign->GetRHS());
         if (canVec) {
           if (iassign->GetFieldID() != 0) {  // check base of iassign
-            MeExpr *meExpr = (*lfoExprParts)[iassign->Opnd(0)]->GetMeExpr();
-            canVec = doloopInfo->IsLoopInvariant(meExpr);
+            canVec = doloopInfo->IsLoopInvariant2(iassign->Opnd(0));
             if ((!canVec) && enableDebug) {
               LogInfo::MapleLogger() << "NOT VECTORIZABLE because of baseaddress is not const with non-zero filedID\n";
             }
@@ -977,8 +972,7 @@ bool LoopVectorization::Vectorizable(DoloopInfo *doloopInfo, LoopVecInfo* vecInf
             return false; // need cvt instruction
           }
           // rsh is loop invariant
-          MeExpr *meExpr = (*lfoExprParts)[iassign->GetRHS()]->GetMeExpr();
-          if (meExpr && doloopInfo->IsLoopInvariant(meExpr)) {
+          if (doloopInfo->IsLoopInvariant2(iassign->GetRHS())) {
             vecInfo->uniformNodes.insert(iassign->GetRHS());
           }
           vecInfo->vecStmtIDs.insert((stmt)->GetStmtID());