diff --git a/src/mapleall/maple_be/include/cg/cgfunc.h b/src/mapleall/maple_be/include/cg/cgfunc.h
index 8c30d3ba73159803822c01c072f58a9d21dd1813..c85ce8d38a5c971e37e92cc1e376df2b1f61eb9e 100644
--- a/src/mapleall/maple_be/include/cg/cgfunc.h
+++ b/src/mapleall/maple_be/include/cg/cgfunc.h
@@ -151,6 +151,7 @@ class CGFunc {
   void MarkCleanupEntryBB();
   void SetCleanupLabel(BB &cleanupEntry);
   bool ExitbbNotInCleanupArea(const BB &bb) const;
+  void DeleteUnneededCleanup();
   uint32 GetMaxRegNum() const {
     return maxRegCount;
   };
diff --git a/src/mapleall/maple_be/src/cg/aarch64/aarch64_ico.cpp b/src/mapleall/maple_be/src/cg/aarch64/aarch64_ico.cpp
index a95ab225044b48786922389db7bb82ab548e7357..8027f3181bc6f0d09cabe10587b648899901301f 100644
--- a/src/mapleall/maple_be/src/cg/aarch64/aarch64_ico.cpp
+++ b/src/mapleall/maple_be/src/cg/aarch64/aarch64_ico.cpp
@@ -544,10 +544,18 @@ bool AArch64ICOIfThenElsePattern::DoOpt(BB &cmpBB, BB *ifBB, BB *elseBB, BB &joi
 
   /* Remove branches and merge join */
   if (ifBB != nullptr) {
+    BB *prevLast = ifBB->GetPrev();
     cgFunc->GetTheCFG()->RemoveBB(*ifBB);
+    if (ifBB->GetId() == cgFunc->GetLastBB()->GetId()) {
+      cgFunc->SetLastBB(*prevLast);
+    }
   }
   if (elseBB != nullptr) {
+    BB *prevLast = elseBB->GetPrev();
     cgFunc->GetTheCFG()->RemoveBB(*elseBB);
+    if (elseBB->GetId() == cgFunc->GetLastBB()->GetId()) {
+      cgFunc->SetLastBB(*prevLast);
+    }
   }
 
   if (cmpBB.GetKind() != BB::kBBIf && cmpBB.GetNext() == &joinBB &&
diff --git a/src/mapleall/maple_be/src/cg/cfgo.cpp b/src/mapleall/maple_be/src/cg/cfgo.cpp
index 33e19c8c62a22b3578ace428f512533525c078a0..ff5d476b5da8185edcb744488702c1b458f8837e 100644
--- a/src/mapleall/maple_be/src/cg/cfgo.cpp
+++ b/src/mapleall/maple_be/src/cg/cfgo.cpp
@@ -143,8 +143,14 @@ bool ChainingPattern::MoveSuccBBAsCurBBNext(BB &curBB, BB &sucBB) {
     sucBB.GetNext()->SetPrev(sucBB.GetPrev());
   }
   sucBB.SetNext(curBB.GetNext());
-  ASSERT(curBB.GetNext() != nullptr, "current goto BB will not be the last bb");
-  curBB.GetNext()->SetPrev(&sucBB);
+  if (curBB.GetNext() != nullptr) {
+    curBB.GetNext()->SetPrev(&sucBB);
+  }
+  if (sucBB.GetId() == cgFunc->GetLastBB()->GetId()) {
+    cgFunc->SetLastBB(*(sucBB.GetPrev()));
+  } else if (curBB.GetId() == cgFunc->GetLastBB()->GetId()) {
+    cgFunc->SetLastBB(sucBB);
+  }
   sucBB.SetPrev(&curBB);
   curBB.SetNext(&sucBB);
   curBB.RemoveInsn(*curBB.GetLastInsn());
@@ -727,8 +733,11 @@ bool UnreachBBPattern::Optimize(BB &curBB) {
 
     ASSERT(curBB.GetPrev() != nullptr, "nullptr check");
     curBB.GetPrev()->SetNext(curBB.GetNext());
-    ASSERT(curBB.GetNext() != nullptr, "nullptr check");
-    curBB.GetNext()->SetPrev(curBB.GetPrev());
+    if (curBB.GetNext() == nullptr) {
+      cgFunc->SetLastBB(*(curBB.GetPrev()));
+    } else {
+      curBB.GetNext()->SetPrev(curBB.GetPrev());
+    }
 
     /* flush after remove; */
     for (BB *bb : curBB.GetSuccs()) {
diff --git a/src/mapleall/maple_be/src/cg/cg_cfg.cpp b/src/mapleall/maple_be/src/cg/cg_cfg.cpp
index f0bce5d888493a23710bab5c1b774525d285dcdd..90ea8e453050124c37e37daf7dc08cd091055a6a 100644
--- a/src/mapleall/maple_be/src/cg/cg_cfg.cpp
+++ b/src/mapleall/maple_be/src/cg/cg_cfg.cpp
@@ -252,7 +252,11 @@ bool CGCFG::AreCommentAllPreds(const BB &bb) {
 
 /* Merge sucBB into curBB. */
 void CGCFG::MergeBB(BB &merger, BB &mergee, CGFunc &func) {
+  BB *prevLast = mergee.GetPrev();
   MergeBB(merger, mergee);
+  if (func.GetLastBB()->GetId() == mergee.GetId()) {
+    func.SetLastBB(*prevLast);
+  }
   if (mergee.GetKind() == BB::kBBReturn) {
     for (size_t i = 0; i < func.ExitBBsVecSize(); ++i) {
       if (func.GetExitBB(i) == &mergee) {
@@ -468,9 +472,11 @@ void CGCFG::RemoveBB(BB &curBB, bool isGotoIf) {
   for (BB *ehPred : curBB.GetEhPreds()) {
     ehPred->RemoveEhSuccs(curBB);
   }
-  curBB.GetNext()->RemovePreds(curBB);
+  if (curBB.GetNext()) {
+    curBB.GetNext()->RemovePreds(curBB);
+    curBB.GetNext()->SetPrev(curBB.GetPrev());
+  }
   curBB.GetPrev()->SetNext(curBB.GetNext());
-  curBB.GetNext()->SetPrev(curBB.GetPrev());
   cgFunc->ClearBBInVec(curBB.GetId());
   /* remove callsite */
   EHFunc* ehFunc = cgFunc->GetEHFunc();
@@ -809,6 +815,9 @@ void CGCFG::BreakCriticalEdge(BB &pred, BB &succ) {
       cgFunc->SetLastBB(*newBB);
     } else {
       exitBB->AppendBB(*newBB);
+      if (cgFunc->GetLastBB() == exitBB) {
+        cgFunc->SetLastBB(*newBB);
+      }
     }
     newBB->AppendInsn(cgFunc->GetCG()->BuildInstruction<AArch64Insn>(
         MOP_xuncond, cgFunc->GetOrCreateLabelOperand(succ.GetLabIdx())));
diff --git a/src/mapleall/maple_be/src/cg/cgfunc.cpp b/src/mapleall/maple_be/src/cg/cgfunc.cpp
index dfd50b9e25031fd57650e13c1daf1232eb2396d1..093fec81d8c4edb15a9b01feb46e39e9e3a7f095 100644
--- a/src/mapleall/maple_be/src/cg/cgfunc.cpp
+++ b/src/mapleall/maple_be/src/cg/cgfunc.cpp
@@ -1653,6 +1653,29 @@ bool CGFunc::ExitbbNotInCleanupArea(const BB &bb) const {
   return true;
 }
 
+void CGFunc::DeleteUnneededCleanup() {
+  if (mirModule.GetSrcLang() != kSrcLangC) {
+    return;
+  }
+  std::list<BB *> delBB;
+  FOR_ALL_BB(bb, this) {
+    if (bb->IsCleanup()) {
+      delBB.push_back(bb);
+    }
+  }
+  for (auto bb : delBB) {
+    if (bb == this->GetLastBB()) {
+      this->SetLastBB(*bb->GetPrev());
+    }
+    bb->GetPrev()->SetNext(bb->GetNext());
+    if (bb->GetNext()) {
+      bb->GetNext()->SetPrev(bb->GetPrev());
+    }
+    bb->SetPrev(nullptr);
+    bb->SetNext(nullptr);
+  }
+}
+
 /*
  * Do mem barrier optimization for constructor funcs as follow:
  * membarstorestore
@@ -1745,6 +1768,15 @@ void CGFunc::AddCommonExitBB() {
       commonExitBB->PushBackPreds(*cgbb);
     }
   }
+  if (mirModule.GetSrcLang() != kSrcLangC) {
+    BB *oldLastBB = GetLastBB();
+    oldLastBB->SetNext(commonExitBB);
+    commonExitBB->SetPrev(oldLastBB);
+    commonExitBB->SetNext(nullptr);
+    /* fake commonExitBB only has preds, no succs, so it is not reachable */
+    commonExitBB->SetUnreachable(true);
+    SetLastBB(*commonExitBB);
+  }
 }
 
 void CGFunc::UpdateCallBBFrequency() {
@@ -1799,6 +1831,7 @@ void CGFunc::HandleFunction() {
   if (CGOptions::IsLazyBinding() && !GetCG()->IsLibcore()) {
     ProcessLazyBinding();
   }
+  DeleteUnneededCleanup();
   if (GetCG()->DoPatchLongBranch()) {
     PatchLongBranch();
   }