diff --git a/src/DeadCodeElimination.cpp b/src/DeadCodeElimination.cpp
index ffe6022..a986b18 100644
--- a/src/DeadCodeElimination.cpp
+++ b/src/DeadCodeElimination.cpp
@@ -37,7 +37,7 @@ void DeadCodeElimination::eliminateDeadStores(Function* func, bool& changed) {
       auto storeInst = dynamic_cast<StoreInst*>(inst);
       auto pointer = storeInst->getPointer();
       // 如果是全局变量或者是函数的数组参数
-      if (isGlobal(pointer) || (isArr(pointer) &&
+      if (SysYIROptUtils::isGlobal(pointer) || (SysYIROptUtils::isArr(pointer) &&
             std::find(func->getEntryBlock()->getArguments().begin(),
                     func->getEntryBlock()->getArguments().end(),
                     pointer) != func->getEntryBlock()->getArguments().end())) {
@@ -63,7 +63,7 @@ void DeadCodeElimination::eliminateDeadStores(Function* func, bool& changed) {
           std::cout << "=== Dead Store Found ===\n";
           SysYPrinter::printInst(storeInst);
         }
-        usedelete(storeInst);
+        SysYIROptUtils::usedelete(storeInst);
         iter = instrs.erase(iter);
       } else {
         ++iter;
@@ -85,7 +85,7 @@ void DeadCodeElimination::eliminateDeadLoads(Function* func, bool& changed) {
             std::cout << "=== Dead Load Binary Unary Found ===\n";
             SysYPrinter::printInst(inst);
           }
-          usedelete(inst);
+          SysYIROptUtils::usedelete(inst);
           iter = instrs.erase(iter);
           continue;
         }
@@ -114,7 +114,7 @@ void DeadCodeElimination::eliminateDeadAllocas(Function* func, bool& changed) {
             std::cout << "=== Dead Alloca Found ===\n";
             SysYPrinter::printInst(inst);
           }
-          usedelete(inst);
+          SysYIROptUtils::usedelete(inst);
           iter = instrs.erase(iter);
           continue;
         }
@@ -183,7 +183,7 @@ void DeadCodeElimination::eliminateDeadRedundantLoadStore(Function* func, bool&
         /// 如果 pointer 仅被该 phi 使用，可以删除 ph
         if (tag) {
           changed = true;
-          usedelete(inst);
+          SysYIROptUtils::usedelete(inst);
           iter = instrs.erase(iter);
           continue;
         }
@@ -193,7 +193,7 @@ void DeadCodeElimination::eliminateDeadRedundantLoadStore(Function* func, bool&
         auto pointer = memsetInst->getPointer();
         if (pointer->getUses().empty()) {
           changed = true;
-          usedelete(inst);
+          SysYIROptUtils::usedelete(inst);
           iter = instrs.erase(iter);
           continue;
         }
@@ -234,7 +234,7 @@ void DeadCodeElimination::eliminateDeadRedundantLoadStore(Function* func, bool&
                         SysYPrinter::printInst(loadInst);
                         SysYPrinter::printInst(nextStore);
                       }
-                      usedelete(loadInst);
+                      SysYIROptUtils::usedelete(loadInst);
                       iter = instrs.erase(iter);
                       // 删除 prevStore 这里是不是可以留给删除无用store处理？
                       // if (prevStore->getUses().empty()) {
@@ -256,21 +256,4 @@ void DeadCodeElimination::eliminateDeadRedundantLoadStore(Function* func, bool&
 }
 
 
-bool DeadCodeElimination::isGlobal(Value *val){
-  auto gval = dynamic_cast<GlobalValue *>(val);
-  return gval != nullptr;
-}
-
-bool DeadCodeElimination::isArr(Value *val){
-  auto aval = dynamic_cast<AllocaInst *>(val);
-  return aval != nullptr && aval->getNumDims() != 0;
-}
-
-void DeadCodeElimination::usedelete(Instruction *instr){
-  for (auto &use1 : instr->getOperands()) {
-    auto val1 = use1->getValue();
-    val1->removeUse(use1);
-  }
-}
-
 } // namespace sysy
\ No newline at end of file
diff --git a/src/Mem2Reg.cpp b/src/Mem2Reg.cpp
index db584ed..fd7a239 100644
--- a/src/Mem2Reg.cpp
+++ b/src/Mem2Reg.cpp
@@ -75,7 +75,7 @@ auto Mem2Reg::computeValue2Blocks() -> void {
         // std::cout << std::endl;
 
         if (instr->isAlloca()) {
-          if (!(isArr(instr.get()) || isGlobal(instr.get()))) {
+          if (!(SysYIROptUtils::isArr(instr.get()) || SysYIROptUtils::isGlobal(instr.get()))) {
             // std::cout << "    Found alloca: ";
             // printer.printInst(instr.get());
             // std::cout << " -> Adding to allocBlocks" << std::endl;
@@ -92,7 +92,7 @@ auto Mem2Reg::computeValue2Blocks() -> void {
           // std::cout << "    Store target: ";
           // printer.printInst(dynamic_cast<Instruction *>(val));
           
-          if (!(isArr(val) || isGlobal(val))) {
+          if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
             // std::cout << "    Adding store to defBlocks for value: ";
             // printer.printInst(dynamic_cast<Instruction *>(instr.get()));
             // std::cout << std::endl;
@@ -108,7 +108,7 @@ auto Mem2Reg::computeValue2Blocks() -> void {
           // printer.printInst(dynamic_cast<Instruction *>(val));
           // std::cout << std::endl;
           
-          if (!(isArr(val) || isGlobal(val))) {
+          if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
             // std::cout << "    Adding load to useBlocks for value: ";
             // printer.printInst(dynamic_cast<Instruction *>(val));
             // std::cout << std::endl;
@@ -199,7 +199,7 @@ auto Mem2Reg::cascade(Instruction *instr, bool &changed, Function *func, BasicBl
         auto tofind =
             std::find_if(instrs.begin(), instrs.end(), [&top](const auto &instr) { return instr.get() == top; });
         assert(tofind != instrs.end());
-        usedelete(tofind->get());
+        SysYIROptUtils::usedelete(tofind->get());
         instrs.erase(tofind);
       }
     }
@@ -291,7 +291,7 @@ auto Mem2Reg::preOptimize1() -> void {
           continue;
         }
 
-        usedelete(tofind->get());
+        SysYIROptUtils::usedelete(tofind->get());
         bb->getInstructions().erase(tofind);
         iter = vToAllocB.erase(iter);
       } else {
@@ -334,7 +334,7 @@ auto Mem2Reg::preOptimize1() -> void {
                 std::cout << std::endl;
 
                 auto valUsedByStore = dynamic_cast<Instruction *>((*it)->getOperand(0));
-                usedelete(it->get());
+                SysYIROptUtils::usedelete(it->get());
                 
                 if (valUsedByStore != nullptr && 
                     valUsedByStore->getUses().size() == 1 &&
@@ -370,7 +370,7 @@ auto Mem2Reg::preOptimize1() -> void {
                                           return instr.get() == val; 
                                         });
               if (tofind != bb->getInstructions().end()) {
-                usedelete(tofind->get());
+                SysYIROptUtils::usedelete(tofind->get());
                 bb->getInstructions().erase(tofind);
               } else {
                 std::cerr << "ERROR: Alloca not found in BB!" << std::endl;
@@ -423,7 +423,7 @@ auto Mem2Reg::preOptimize2() -> void {
         for (auto curit = std::next(it); curit != instrs.end();) {
           if ((*curit)->isLoad() && (*curit)->getOperand(0) == val) {
             curit->get()->replaceAllUsesWith(propogationVal);
-            usedelete(curit->get());
+            SysYIROptUtils::usedelete(curit->get());
             curit = instrs.erase(curit);
             funcInfo->removeValue2UseBlock(val, block);
           } else {
@@ -454,7 +454,7 @@ auto Mem2Reg::preOptimize2() -> void {
           for (auto childIter = childInstrs.begin(); childIter != childInstrs.end();) {
             if ((*childIter)->isLoad() && (*childIter)->getOperand(0) == val) {
               childIter->get()->replaceAllUsesWith(propogationVal);
-              usedelete(childIter->get());
+              SysYIROptUtils::usedelete(childIter->get());
               childIter = childInstrs.erase(childIter);
               funcInfo->removeValue2UseBlock(val, child);
             } else {
@@ -465,7 +465,7 @@ auto Mem2Reg::preOptimize2() -> void {
         // 如果对该val的所有load均替换掉了，那么对于该val的defining block中的最后一个define也可以删除了
         // 同时该块中前面对于该val的define也变成死代码了，可调用preOptimize1进行删除
         if (funcInfo->getUseBlocksByValue(val).empty()) {
-          usedelete(it->get());
+          SysYIROptUtils::usedelete(it->get());
           instrs.erase(it);
           auto change = funcInfo->removeValue2DefBlock(val, block);
           if (change) {
@@ -476,7 +476,7 @@ auto Mem2Reg::preOptimize2() -> void {
               assert(bb != nullptr);
               auto tofind = std::find_if(bb->getInstructions().begin(), bb->getInstructions().end(),
                                          [val](const auto &instr) { return instr.get() == val; });
-              usedelete(tofind->get());
+              SysYIROptUtils::usedelete(tofind->get());
               bb->getInstructions().erase(tofind);
               funcInfo->removeValue2AllocBlock(val);
             }
@@ -529,7 +529,7 @@ auto Mem2Reg::preOptimize3() -> void {
           for (auto curit = std::next(it); curit != last;) {
             if ((*curit)->isLoad() && (*curit)->getOperand(0) == val) {
               curit->get()->replaceAllUsesWith(propogationVal);
-              usedelete(curit->get());
+              SysYIROptUtils::usedelete(curit->get());
               curit = instrs.erase(curit);
               funcInfo->removeValue2UseBlock(val, block);
             } else {
@@ -541,14 +541,14 @@ auto Mem2Reg::preOptimize3() -> void {
                              [val](const auto &instr) { return instr == val; }) !=
                 func->getEntryBlock()->getArguments().end()) &&
               last == instrs.end()) {
-            usedelete(it->get());
+            SysYIROptUtils::usedelete(it->get());
             it = instrs.erase(it);
             if (funcInfo->removeValue2DefBlock(val, block)) {
               auto bb = funcInfo->getAllocBlockByValue(val);
               if (bb != nullptr) {
                 auto tofind = std::find_if(bb->getInstructions().begin(), bb->getInstructions().end(),
                                            [val](const auto &instr) { return instr.get() == val; });
-                usedelete(tofind->get());
+                SysYIROptUtils::usedelete(tofind->get());
                 bb->getInstructions().erase(tofind);
                 funcInfo->removeValue2AllocBlock(val);
               }
@@ -610,7 +610,7 @@ auto Mem2Reg::rename(BasicBlock *block, std::unordered_map<Value *, int> &count,
     // 对于load指令，变量用最新的那个
     if (instr->isLoad()) {
       auto val = instr->getOperand(0);
-      if (!(isArr(val) || isGlobal(val))) {
+      if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
         if (!stacks[val].empty()) {
           instr->replaceOperand(0, stacks[val].top());
         }
@@ -621,7 +621,7 @@ auto Mem2Reg::rename(BasicBlock *block, std::unordered_map<Value *, int> &count,
       if (instr->isAlloca()) {
         // alloca指令名字不改了，命名就按x，x_1，x_2...来就行
         auto val = instr;
-        if (!(isArr(val) || isGlobal(val))) {
+        if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
           ++valPop[val];
           stacks[val].push(val);
           ++count[val];
@@ -629,11 +629,11 @@ auto Mem2Reg::rename(BasicBlock *block, std::unordered_map<Value *, int> &count,
       } else if (instr->isPhi()) {
         // Phi指令也是一条特殊的define指令
         auto val = dynamic_cast<PhiInst *>(instr)->getMapVal();
-        if (!(isArr(val) || isGlobal(val))) {
+        if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
           auto i = count[val];
           if (i == 0) {
             // 对还未alloca就有phi的指令的处理，直接删除
-            usedelete(iter->get());
+            SysYIROptUtils::usedelete(iter->get());
             iter = instrs.erase(iter);
             continue;
           }
@@ -649,7 +649,7 @@ auto Mem2Reg::rename(BasicBlock *block, std::unordered_map<Value *, int> &count,
       } else {
         // store指令看operand的名字，我们的实现是规定变量在operand的第二位，用一个新的alloca x_i代替
         auto val = instr->getOperand(1);
-        if (!(isArr(val) || isGlobal(val))) {
+        if (!(SysYIROptUtils::isArr(val) || SysYIROptUtils::isGlobal(val))) {
           auto i = count[val];
           auto newname = dynamic_cast<Instruction *>(val)->getName() + "_" + std::to_string(i);
           auto newalloca = pBuilder->createAllocaInstWithoutInsert(val->getType(), {}, block, newname);
@@ -773,29 +773,4 @@ auto Mem2Reg::getPredIndex(BasicBlock *n, BasicBlock *s) -> int {
   return index;
 }
 
-/**
- * 判断一个value是不是全局变量
- */
-auto Mem2Reg::isGlobal(Value *val) -> bool {
-  auto gval = dynamic_cast<GlobalValue *>(val);
-  return gval != nullptr;
-}
-
-/**
- * 判断一个value是不是数组
- */
-auto Mem2Reg::isArr(Value *val) -> bool {
-  auto aval = dynamic_cast<AllocaInst *>(val);
-  return aval != nullptr && aval->getNumDims() != 0;
-}
-
-/**
- * 删除一个指令的operand对应的value的该条use
- */
-auto Mem2Reg::usedelete(Instruction *instr) -> void {
-  for (auto &use : instr->getOperands()) {
-    auto val = use->getValue();
-    val->removeUse(use);
-  }
-}
 }  // namespace sysy
diff --git a/src/Reg2Mem.cpp b/src/Reg2Mem.cpp
index d44d1c8..70bdd14 100644
--- a/src/Reg2Mem.cpp
+++ b/src/Reg2Mem.cpp
@@ -103,7 +103,7 @@ void Reg2Mem::DeletePhiInst(){
           }
           // 删除phi指令
           auto &instructions = basicBlock->getInstructions();
-          usedelete(iter->get());
+          SysYIROptUtils::usedelete(iter->get());
           iter = instructions.erase(iter);
           if (basicBlock->getNumInstructions() == 0) {
             if (basicBlock->getNumSuccessors() == 1) {
@@ -119,11 +119,4 @@ void Reg2Mem::DeletePhiInst(){
   }
 }
 
-void Reg2Mem::usedelete(Instruction *instr) {
-  for (auto &use : instr->getOperands()) {
-    auto val = use->getValue();
-    val->removeUse(use);
-  }
-}
-
 }  // namespace sysy
diff --git a/src/SysYIROptPre.cpp b/src/SysYIROptPre.cpp
index fb05cb7..9eb495c 100644
--- a/src/SysYIROptPre.cpp
+++ b/src/SysYIROptPre.cpp
@@ -1,4 +1,5 @@
 #include "SysYIROptPre.h"
+#include "SysYIROptUtils.h"
 #include <cassert>
 #include <list>
 #include <map>
@@ -10,18 +11,6 @@
 
 namespace sysy {
 
-/**
- * use删除operand,以免扰乱后续分析
- * instr: 要删除的指令
- */
-void SysYOptPre::usedelete(Instruction *instr) {
-  for (auto &use : instr->getOperands()) {
-    Value* val = use->getValue();
-    // std::cout << delete << val->getName() << std::endl;
-    val->removeUse(use);
-  }
-}
-
 
 // 删除br后的无用指令
 void SysYOptPre::SysYDelInstAfterBr() {
@@ -34,7 +23,7 @@ void SysYOptPre::SysYDelInstAfterBr() {
       auto Branchiter = instructions.end();
       for (auto iter = instructions.begin(); iter != instructions.end(); ++iter) {
         if (Branch) 
-          usedelete(iter->get());
+          SysYIROptUtils::usedelete(iter->get());
         else if ((*iter)->isTerminator()){
           Branch = true;
           Branchiter = iter;
@@ -69,7 +58,7 @@ void SysYOptPre::SysYDelInstAfterBr() {
   }
 }
 
-
+// 合并空基本块
 void SysYOptPre::SysYBlockMerge() {
   auto &functions = pModule->getFunctions(); //std::map<std::string, std::unique_ptr<Function>>
   for (auto &function : functions) {
@@ -91,12 +80,12 @@ void SysYOptPre::SysYBlockMerge() {
             auto thelastinstinst = block->end();
             (--thelastinstinst);
             if (thelastinstinst->get()->isUnconditional()) {
-              usedelete(thelastinstinst->get());
+              SysYIROptUtils::usedelete(thelastinstinst->get());
               block->getInstructions().erase(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()) {
-                usedelete(thelastinstinst->get());
+                SysYIROptUtils::usedelete(thelastinstinst->get());
                 block->getInstructions().erase(thelastinstinst);
               }
             }
@@ -170,7 +159,7 @@ void SysYOptPre::SysYDelNoPreBLock() {
       
       if (!blockIter->get()->getreachable()) 
         for (auto &iterInst : blockIter->get()->getInstructions()) 
-          usedelete(iterInst.get());
+          SysYIROptUtils::usedelete(iterInst.get());
     
     }
 
@@ -303,7 +292,7 @@ void SysYOptPre::SysYDelEmptyBlock() {
         if (dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1)) ==
             dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(2))) {
           auto thebrBlock = dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1));
-          usedelete(thelastinst->get());
+          SysYIROptUtils::usedelete(thelastinst->get());
           thelastinst = basicBlock->getInstructions().erase(thelastinst);
           pBuilder->setPosition(basicBlock.get(), basicBlock->end());
           pBuilder->createUncondBrInst(thebrBlock, {});
@@ -344,7 +333,7 @@ void SysYOptPre::SysYDelEmptyBlock() {
         if (dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1)) ==
             dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(2))) {
           auto thebrBlock = dynamic_cast<BasicBlock *>(thelastinst->get()->getOperand(1));
-          usedelete(thelastinst->get());
+          SysYIROptUtils::usedelete(thelastinst->get());
           thelastinst = basicBlock->getInstructions().erase(thelastinst);
           pBuilder->setPosition(basicBlock.get(), basicBlock->end());
           pBuilder->createUncondBrInst(thebrBlock, {});
@@ -420,7 +409,7 @@ void SysYOptPre::SysYDelEmptyBlock() {
         }
 
         for (auto &iterInst : iter->get()->getInstructions()) 
-          usedelete(iterInst.get());
+          SysYIROptUtils::usedelete(iterInst.get());
         // 删除不可达基本块的phi指令的操作数
         for (auto &succ : iter->get()->getSuccessors()) {
           int index = 0;
diff --git a/src/include/DeadCodeElimination.h b/src/include/DeadCodeElimination.h
index 72b9935..9864a2d 100644
--- a/src/include/DeadCodeElimination.h
+++ b/src/include/DeadCodeElimination.h
@@ -3,6 +3,7 @@
 #include "IR.h"
 #include "SysYIRAnalyser.h"
 #include "SysYIRPrinter.h"
+#include "SysYIROptUtils.h"
 
 namespace sysy {
 
@@ -31,9 +32,5 @@ class DeadCodeElimination {
   void eliminateDeadGlobals(bool& changed);   // 消除无用全局变量
   void eliminateDeadIndirectiveAllocas(Function* func, bool& changed);  // 消除无用间接内存分配(phi节点)
   void eliminateDeadRedundantLoadStore(Function* func, bool& changed);  // 消除冗余加载和存储
-  bool isGlobal(Value *val);
-  bool isArr(Value *val);
-  void usedelete(Instruction *instr);
-
 };
 }  // namespace sysy
diff --git a/src/include/Mem2Reg.h b/src/include/Mem2Reg.h
index 0004708..919886a 100644
--- a/src/include/Mem2Reg.h
+++ b/src/include/Mem2Reg.h
@@ -8,6 +8,7 @@
 #include "IR.h"
 #include "IRBuilder.h"
 #include "SysYIRAnalyser.h"
+#include "SysYIROptUtils.h"
 
 namespace sysy {
 /**
@@ -51,9 +52,6 @@ private:
   auto getPredIndex(BasicBlock *n, BasicBlock *s) -> int;  ///< 获取前驱索引
   auto cascade(Instruction *instr, bool &changed, Function *func, BasicBlock *block,
                std::list<std::unique_ptr<Instruction>> &instrs) -> void;  ///< 消除级联关系
-  auto isGlobal(Value *val) -> bool;                                      ///< 判断是否是全局变量
-  auto isArr(Value *val) -> bool;                                         ///< 判断是否是数组
-  auto usedelete(Instruction *instr) -> void;                             ///< 删除指令相关的value-use-user关系
 
 };
 }  // namespace sysy
diff --git a/src/include/Reg2Mem.h b/src/include/Reg2Mem.h
index 6249d71..8eec1b6 100644
--- a/src/include/Reg2Mem.h
+++ b/src/include/Reg2Mem.h
@@ -2,6 +2,7 @@
 
 #include "IR.h"
 #include "IRBuilder.h"
+#include "SysYIROptUtils.h"
 
 namespace sysy {
 /**
@@ -16,8 +17,6 @@ public:
   Reg2Mem(Module *pMoudle, IRBuilder *pBuilder) : pModule(pMoudle), pBuilder(pBuilder) {}
 
   void DeletePhiInst();
-  // 删除UD关系, 因为删除了phi指令会修改ud关系
-  void usedelete(Instruction *instr);
 };
 
 } // namespace sysy
\ No newline at end of file
diff --git a/src/include/SysYIROptPre.h b/src/include/SysYIROptPre.h
index 4f0bdca..5cb0b34 100644
--- a/src/include/SysYIROptPre.h
+++ b/src/include/SysYIROptPre.h
@@ -10,6 +10,11 @@ namespace sysy {
 // 这些操作可以在SysY IR生成时就完成，但为了简化IR生成过程，
 // 这里将其放在SysY IR生成后进行预处理
 // 同时兼容phi节点的处理，可以再mem2reg后再次调用优化
+
+//TODO: 可增加的CFG优化
+// - 简化条件分支（Branch Simplification），如条件恒真/恒假转为直接跳转
+// - 合并连续的跳转指令（Jump Threading）在合并不可达块中似乎已经实现了
+// - 基本块重排序（Block Reordering），提升局部性
 class SysYOptPre {
  private:
   Module *pModule;
@@ -31,7 +36,6 @@ class SysYOptPre {
   void SysYBlockMerge();    // 合并基本块(主要针对嵌套if while的exit块，
                             // 也可以修改IR生成实现回填机制
   void SysYAddReturn();     // 添加return指令(主要针对Void函数)
-  void usedelete(Instruction *instr); // use删除
 };
 
 }  // namespace sysy
diff --git a/src/include/SysYIROptUtils.h b/src/include/SysYIROptUtils.h
new file mode 100644
index 0000000..d2d2e55
--- /dev/null
+++ b/src/include/SysYIROptUtils.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include "IR.h"
+
+namespace sysy {
+
+// 优化工具类，包含一些通用的优化方法
+// 这些方法可以在不同的优化 pass 中复用
+// 例如：删除use关系,判断是否是全局变量等
+class SysYIROptUtils{
+
+public:
+  // 删除use关系
+  static void usedelete(Instruction *instr) {
+    for (auto &use : instr->getOperands()) {
+      Value* val = use->getValue();
+      val->removeUse(use);
+    }
+  }
+
+  // 判断是否是全局变量
+  static bool isGlobal(Value *val) {
+    auto gval = dynamic_cast<GlobalValue *>(val);
+    return gval != nullptr;
+  }
+  // 判断是否是数组
+  static bool isArr(Value *val) {
+    auto aval = dynamic_cast<AllocaInst *>(val);
+  return aval != nullptr && aval->getNumDims() != 0;
+  }
+};
+
+}// namespace sysy
\ No newline at end of file