diff --git a/src/midend/Pass/Optimize/DCE.cpp b/src/midend/Pass/Optimize/DCE.cpp
index db5d966..2da1873 100644
--- a/src/midend/Pass/Optimize/DCE.cpp
+++ b/src/midend/Pass/Optimize/DCE.cpp
@@ -51,10 +51,8 @@ void DCEContext::run(Function *func, AnalysisManager *AM, bool &changed) {
       // 如果指令不在活跃集合中，则删除它。
       // 分支和返回指令由 isAlive 处理，并会被保留。
       if (alive_insts.count(currentInst) == 0) {
-        // 删除指令，保留用户风格的 SysYIROptUtils::usedelete 和 erase
+        instIter =  SysYIROptUtils::usedelete(instIter); // 删除后返回下一个迭代器
         changed = true; // 标记 IR 已被修改
-        SysYIROptUtils::usedelete(currentInst);
-        instIter = basicBlock->getInstructions().erase(instIter); // 删除后返回下一个迭代器
       } else {
         ++instIter; // 指令活跃，移动到下一个
       }
diff --git a/src/midend/Pass/Optimize/Mem2Reg.cpp b/src/midend/Pass/Optimize/Mem2Reg.cpp
index c6e856f..2447b97 100644
--- a/src/midend/Pass/Optimize/Mem2Reg.cpp
+++ b/src/midend/Pass/Optimize/Mem2Reg.cpp
@@ -240,10 +240,9 @@ void Mem2RegContext::renameVariables(AllocaInst *currentAlloca, BasicBlock *curr
           // loadInst->getPointer() 返回 AllocaInst*
           // 将 LoadInst 的所有用途替换为当前 alloca 值栈顶部的 SSA 值
           assert(!allocaToValueStackMap[alloca].empty() && "Value stack empty for alloca during load replacement!");
+          std::cout << "Mem2Reg: Replacing load " << loadInst->getPointer()->getName() << " with SSA value." << std::endl;
           loadInst->replaceAllUsesWith(allocaToValueStackMap[alloca].top());
-          // instIter = currentBB->force_delete_inst(loadInst); // 删除 LoadInst
-          SysYIROptUtils::usedelete(loadInst); // 仅删除 use 关系
-          instIter = currentBB->getInstructions().erase(instIter); // 删除 LoadInst
+          instIter = SysYIROptUtils::usedelete(instIter);
           instDeleted = true;
           // std::cerr << "Mem2Reg: Replaced load " << loadInst->name() << " with SSA value." << std::endl;
           break;
@@ -257,10 +256,10 @@ void Mem2RegContext::renameVariables(AllocaInst *currentAlloca, BasicBlock *curr
         if (storeInst->getPointer() == alloca) { 
           // 假设 storeInst->getPointer() 返回 AllocaInst*
           // 将 StoreInst 存储的值作为新的 SSA 值，压入值栈
+          std::cout << "Mem2Reg: Replacing store to " << storeInst->getPointer()->getName() << " with SSA value." << std::endl;
           allocaToValueStackMap[alloca].push(storeInst->getValue());
           localStackPushed.push(storeInst->getValue());          // 记录以便弹出
-          SysYIROptUtils::usedelete(storeInst);
-          instIter = currentBB->getInstructions().erase(instIter); // 删除 StoreInst
+          instIter = SysYIROptUtils::usedelete(instIter);
           instDeleted = true;
           // std::cerr << "Mem2Reg: Replaced store to " << storeInst->ptr()->name() << " with SSA value." << std::endl;
           break;
@@ -327,7 +326,6 @@ void Mem2RegContext::cleanup() {
     if (alloca && alloca->getParent()) {
       // 删除 alloca 指令本身
       SysYIROptUtils::usedelete(alloca);
-      alloca->getParent()->removeInst(alloca); // 从基本块中删除 alloca
       
       // std::cerr << "Mem2Reg: Deleted alloca " << alloca->name() << std::endl;
     }
diff --git a/src/midend/Pass/Optimize/Reg2Mem.cpp b/src/midend/Pass/Optimize/Reg2Mem.cpp
index 42316a5..199153b 100644
--- a/src/midend/Pass/Optimize/Reg2Mem.cpp
+++ b/src/midend/Pass/Optimize/Reg2Mem.cpp
@@ -181,8 +181,7 @@ void Reg2MemContext::rewritePhis(Function *func) {
   // 实际删除 Phi 指令
   for (auto phi : phisToErase) {
     if (phi && phi->getParent()) {
-      SysYIROptUtils::usedelete(phi);    // 清理 use-def 链
-      phi->getParent()->removeInst(phi); // 从基本块中删除
+      SysYIROptUtils::usedelete(phi);
     }
   }
 }
diff --git a/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp b/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
index 99c06aa..a589453 100644
--- a/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
+++ b/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
@@ -91,13 +91,11 @@ bool SysYCFGOptUtils::SysYBlockMerge(Function *func) {
           auto thelastinstinst = block->end();
           (--thelastinstinst);
           if (thelastinstinst->get()->isUnconditional()) {
-            SysYIROptUtils::usedelete(thelastinstinst->get());
-            thelastinstinst = block->getInstructions().erase(thelastinstinst);
+            thelastinstinst = SysYIROptUtils::usedelete(thelastinstinst);
           } else if (thelastinstinst->get()->isConditional()) {
             // 如果是条件分支，判断条件是否相同，主要优化相同布尔表达式
             if (thelastinstinst->get()->getOperand(1)->getName() == thelastinstinst->get()->getOperand(1)->getName()) {
-              SysYIROptUtils::usedelete(thelastinstinst->get());
-              thelastinstinst = block->getInstructions().erase(thelastinstinst); 
+              thelastinstinst = SysYIROptUtils::usedelete(thelastinstinst);
             }
           }
         }
@@ -164,8 +162,7 @@ bool SysYCFGOptUtils::SysYDelNoPreBLock(Function *func) {
     if (!blockIter->get()->getreachable()) {
       for (auto instIter = blockIter->get()->getInstructions().begin();
           instIter != blockIter->get()->getInstructions().end();) {
-        SysYIROptUtils::usedelete(instIter->get());
-        instIter = blockIter->get()->getInstructions().erase(instIter);
+        instIter = SysYIROptUtils::usedelete(instIter);
       }
     }
   }
@@ -306,8 +303,7 @@ bool SysYCFGOptUtils::SysYDelEmptyBlock(Function *func, IRBuilder* pBuilder) {
       if (dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1)) ==
           dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(2))) {
         auto thebrBlock = dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1));
-        SysYIROptUtils::usedelete(thelastinst->get());
-        thelastinst = basicBlock->getInstructions().erase(thelastinst);
+        thelastinst = SysYIROptUtils::usedelete(thelastinst);
         pBuilder->setPosition(basicBlock.get(), basicBlock->end());
         pBuilder->createUncondBrInst(thebrBlock);
         changed = true; // 标记IR被修改
@@ -345,8 +341,7 @@ bool SysYCFGOptUtils::SysYDelEmptyBlock(Function *func, IRBuilder* pBuilder) {
       if (dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1)) ==
           dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(2))) {
         auto thebrBlock = dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1));
-        SysYIROptUtils::usedelete(thelastinst->get());
-        thelastinst = basicBlock->getInstructions().erase(thelastinst);
+        thelastinst = SysYIROptUtils::usedelete(thelastinst);
         pBuilder->setPosition(basicBlock.get(), basicBlock->end());
         pBuilder->createUncondBrInst(thebrBlock);
         changed = true; // 标记IR被修改
@@ -425,9 +420,7 @@ bool SysYCFGOptUtils::SysYDelEmptyBlock(Function *func, IRBuilder* pBuilder) {
 
       for (auto instIter = iter->get()->getInstructions().begin();
          instIter != iter->get()->getInstructions().end();) {
-        SysYIROptUtils::usedelete(instIter->get()); // 仅删除 use 关系
-        // 显式地从基本块中删除指令并更新迭代器
-        instIter = iter->get()->getInstructions().erase(instIter);
+        instIter = SysYIROptUtils::usedelete(instIter);
       }
       // 删除不可达基本块的phi指令的操作数
       for (auto &succ : iter->get()->getSuccessors()) {
@@ -523,8 +516,7 @@ bool SysYCFGOptUtils::SysYCondBr2Br(Function *func, IRBuilder* pBuilder) {
 
         auto thenBlock = dynamic_cast<BasicBlock *>(thelast->get()->getOperand(1));
         auto elseBlock = dynamic_cast<BasicBlock *>(thelast->get()->getOperand(2));
-        SysYIROptUtils::usedelete(thelast->get());
-        thelast = basicblock->getInstructions().erase(thelast);
+        thelast = SysYIROptUtils::usedelete(thelast);
         if ((constfloat_Use && constfloat == 1.0F) || (constint_Use && constint == 1)) {
           // cond为true或非0
           pBuilder->setPosition(basicblock.get(), basicblock->end());