diff --git a/src/mapleall/maple_me/src/me_cfg.cpp b/src/mapleall/maple_me/src/me_cfg.cpp
index 4b3547b7a7de2270005b14299cfccb6f4bcccd05..1b3252d9e9e0778081f79678597c4869ab28ab2c 100644
--- a/src/mapleall/maple_me/src/me_cfg.cpp
+++ b/src/mapleall/maple_me/src/me_cfg.cpp
@@ -1309,6 +1309,14 @@ void MeCFG::CreateBasicBlocks() {
       }
       case OP_dassign: {
         DassignNode *dass = static_cast<DassignNode*>(stmt);
+        // delete identity assignments inserted by LFO
+        if (dass->GetRHS()->GetOpCode() == OP_dread) {
+          DreadNode *dread = static_cast<DreadNode*>(dass->GetRHS());
+          if (dass->GetStIdx() == dread->GetStIdx() && dass->GetFieldID() == dread->GetFieldID()) {
+            func.CurFunction()->GetBody()->RemoveStmt(stmt);
+            break;
+          }
+        }
         if (curBB->IsEmpty()) {
           curBB->SetFirst(stmt);
         }
diff --git a/src/mapleall/maple_me/src/pme_mir_lower.cpp b/src/mapleall/maple_me/src/pme_mir_lower.cpp
index 048ff7464adc984250344ae1ced00b04a7df7101..fdb427c437edac00a58ce717b1017bc4d883e334 100644
--- a/src/mapleall/maple_me/src/pme_mir_lower.cpp
+++ b/src/mapleall/maple_me/src/pme_mir_lower.cpp
@@ -121,6 +121,80 @@ BlockNode *PreMeMIRLower::LowerIfStmt(IfStmtNode &ifstmt, bool recursive) {
     if (GetFuncProfData()) {
       GetFuncProfData()->CopyStmtFreq(evalstmt->GetStmtID(), ifstmt.GetStmtID());
     }
+  } else if (elseempty && !GetFuncProfData()) {
+    // brfalse <cond> <endlabel>
+    // <thenPart>
+    // label <endlabel>
+    CondGotoNode *brfalsestmt = mirModule.CurFuncCodeMemPool()->New<CondGotoNode>(OP_brfalse);
+    brfalsestmt->SetOpnd(ifstmt.Opnd(), 0);
+    brfalsestmt->SetSrcPos(ifstmt.GetSrcPos());
+    LabelIdx endlabelidx = mirFunc->GetLabelTab()->CreateLabelWithPrefix('e');
+    mirFunc->GetLabelTab()->AddToStringLabelMap(endlabelidx);
+    if (canRaiseBack) {
+      preMeFunc->SetIfLabelCreatedByPreMe(endlabelidx);
+    }
+    PreMeIfInfo *ifInfo = preMeFunc->pmemp->New<PreMeIfInfo>();
+    brfalsestmt->SetOffset(endlabelidx);
+    blk->AddStatement(brfalsestmt);
+    // set stmtfreqs
+    if (GetFuncProfData()) {
+      GetFuncProfData()->CopyStmtFreq(brfalsestmt->GetStmtID(), ifstmt.GetStmtID());
+    }
+    blk->AppendStatementsFromBlock(*ifstmt.GetThenPart());
+
+    LabelNode *labstmt = mirModule.CurFuncCodeMemPool()->New<LabelNode>();
+    labstmt->SetLabelIdx(endlabelidx);
+    ifInfo->endLabel = endlabelidx;
+    if (canRaiseBack) {
+      preMeFunc->label2IfInfo.insert(std::make_pair(endlabelidx, ifInfo));
+    }
+    SrcPosition pos = func->GetMirFunc()->GetScope()->GetScopeEndPos(ifstmt.GetThenPart()->GetSrcPos());
+    labstmt->SetSrcPos(pos);
+    blk->AddStatement(labstmt);
+    // set stmtfreqs
+    if (GetFuncProfData()) {
+      ASSERT(GetFuncProfData()->GetStmtFreq(ifstmt.GetThenPart()->GetStmtID()) >= 0, "sanity check");
+      int64_t freq = GetFuncProfData()->GetStmtFreq(ifstmt.GetStmtID()) -
+                        GetFuncProfData()->GetStmtFreq(ifstmt.GetThenPart()->GetStmtID());
+      GetFuncProfData()->SetStmtFreq(labstmt->GetStmtID(), freq);
+    }
+  } else if (thenempty && !GetFuncProfData()) {
+    // brtrue <cond> <endlabel>
+    // <elsePart>
+    // label <endlabel>
+    CondGotoNode *brtruestmt = mirModule.CurFuncCodeMemPool()->New<CondGotoNode>(OP_brtrue);
+    brtruestmt->SetOpnd(ifstmt.Opnd(), 0);
+    brtruestmt->SetSrcPos(ifstmt.GetSrcPos());
+    LabelIdx endlabelidx = mirFunc->GetLabelTab()->CreateLabelWithPrefix('e');
+    if (canRaiseBack) {
+      preMeFunc->SetIfLabelCreatedByPreMe(endlabelidx);
+    }
+    PreMeIfInfo *ifInfo = preMeFunc->pmemp->New<PreMeIfInfo>();
+    mirFunc->GetLabelTab()->AddToStringLabelMap(endlabelidx);
+    brtruestmt->SetOffset(endlabelidx);
+    blk->AddStatement(brtruestmt);
+
+    // set stmtfreqs
+    if (GetFuncProfData()) {
+      GetFuncProfData()->CopyStmtFreq(brtruestmt->GetStmtID(), ifstmt.GetStmtID());
+    }
+    blk->AppendStatementsFromBlock(*ifstmt.GetElsePart());
+    LabelNode *labstmt = mirModule.CurFuncCodeMemPool()->New<LabelNode>();
+    labstmt->SetLabelIdx(endlabelidx);
+    ifInfo->endLabel = endlabelidx;
+    if (canRaiseBack) {
+      preMeFunc->label2IfInfo.insert(std::make_pair(endlabelidx, ifInfo));
+    }
+    SrcPosition pos = func->GetMirFunc()->GetScope()->GetScopeEndPos(ifstmt.GetElsePart()->GetSrcPos());
+    labstmt->SetSrcPos(pos);
+    blk->AddStatement(labstmt);
+    // set stmtfreqs
+    if (GetFuncProfData()) {
+      ASSERT(GetFuncProfData()->GetStmtFreq(ifstmt.GetElsePart()->GetStmtID()) > 0, "sanity check");
+      int64_t freq = GetFuncProfData()->GetStmtFreq(ifstmt.GetStmtID()) -
+                        GetFuncProfData()->GetStmtFreq(ifstmt.GetElsePart()->GetStmtID());
+      GetFuncProfData()->SetStmtFreq(labstmt->GetStmtID(), freq);
+    }
   } else {
     // brfalse <cond> <elselabel>
     // <thenPart>
@@ -213,13 +287,13 @@ BlockNode *PreMeMIRLower::LowerIfStmt(IfStmtNode &ifstmt, bool recursive) {
     }
     ifInfo->endLabel = endlabelidx;
   }
-  // generate extra label to avoid critical edge
-  LabelIdx extraLabelIdx = mirFunc->GetLabelTab()->CreateLabelWithPrefix('x');
-  preMeFunc->SetIfLabelCreatedByPreMe(extraLabelIdx);
-  LabelNode *extraLabelNode = mirbuilder->CreateStmtLabel(extraLabelIdx);
-  blk->AddStatement(extraLabelNode);
-  // set stmtfreqs
   if (GetFuncProfData()) {
+    // generate extra label to avoid critical edge
+    LabelIdx extraLabelIdx = mirFunc->GetLabelTab()->CreateLabelWithPrefix('x');
+    preMeFunc->SetIfLabelCreatedByPreMe(extraLabelIdx);
+    LabelNode *extraLabelNode = mirbuilder->CreateStmtLabel(extraLabelIdx);
+    blk->AddStatement(extraLabelNode);
+    // set stmtfreqs
     GetFuncProfData()->CopyStmtFreq(extraLabelNode->GetStmtID(), ifstmt.GetStmtID());
   }
   return blk;