diff --git a/src/backend/RISCv64/RISCv64ISel.cpp b/src/backend/RISCv64/RISCv64ISel.cpp
index f84a887..fb9cbd6 100644
--- a/src/backend/RISCv64/RISCv64ISel.cpp
+++ b/src/backend/RISCv64/RISCv64ISel.cpp
@@ -554,6 +554,14 @@ void RISCv64ISel::selectNode(DAGNode* node) {
                     CurMBB->addInstruction(std::move(instr));
                     break;
                 }
+                case BinaryInst::kMulh: {
+                    auto instr = std::make_unique<MachineInstr>(RVOpcodes::MULH);
+                    instr->addOperand(std::make_unique<RegOperand>(dest_vreg));
+                    instr->addOperand(std::make_unique<RegOperand>(lhs_vreg));
+                    instr->addOperand(std::make_unique<RegOperand>(rhs_vreg));
+                    CurMBB->addInstruction(std::move(instr));
+                    break;
+                }
                 case Instruction::kDiv: {
                     auto instr = std::make_unique<MachineInstr>(RVOpcodes::DIVW);
                     instr->addOperand(std::make_unique<RegOperand>(dest_vreg));
diff --git a/src/backend/RISCv64/RISCv64RegAlloc.cpp b/src/backend/RISCv64/RISCv64RegAlloc.cpp
index b3affd2..4bdb9ef 100644
--- a/src/backend/RISCv64/RISCv64RegAlloc.cpp
+++ b/src/backend/RISCv64/RISCv64RegAlloc.cpp
@@ -193,30 +193,30 @@ void RISCv64RegAlloc::protectCrossCallVRegs() {
         return; // 如果没有需要保护的vreg，直接返回
     }
 
-    VRegSet live_across_call_vregs;
-    // 遍历所有指令，找出哪些被标记的vreg其生命周期确实跨越了call指令
-    for (const auto& mbb_ptr : MFunc->getBlocks()) {
-        for (const auto& instr_ptr : mbb_ptr->getInstructions()) {
-            if (instr_ptr->getOpcode() == RVOpcodes::CALL) {
-                const VRegSet& live_out_after_call = live_out_map.at(instr_ptr.get());
-                for (unsigned vreg : vregs_to_protect_potentially) {
-                    if (live_out_after_call.count(vreg)) {
-                        live_across_call_vregs.insert(vreg);
-                    }
-                }
-            }
-        }
-    }
+    // VRegSet live_across_call_vregs;
+    // // 遍历所有指令，找出哪些被标记的vreg其生命周期确实跨越了call指令
+    // for (const auto& mbb_ptr : MFunc->getBlocks()) {
+    //     for (const auto& instr_ptr : mbb_ptr->getInstructions()) {
+    //         if (instr_ptr->getOpcode() == RVOpcodes::CALL) {
+    //             const VRegSet& live_out_after_call = live_out_map.at(instr_ptr.get());
+    //             for (unsigned vreg : vregs_to_protect_potentially) {
+    //                 if (live_out_after_call.count(vreg)) {
+    //                     live_across_call_vregs.insert(vreg);
+    //                 }
+    //             }
+    //         }
+    //     }
+    // }
 
-    if (live_across_call_vregs.empty()) {
-        return; // 如果被标记的vreg没有一个跨越call，也无需操作
-    }
+    // if (live_across_call_vregs.empty()) {
+    //     return; // 如果被标记的vreg没有一个跨越call，也无需操作
+    // }
 
-    if (DEEPDEBUG) {
-        std::cerr << "--- [FIX] Applying protection for argument vregs that live across calls: ";
-        for(unsigned v : live_across_call_vregs) std::cerr << regIdToString(v) << " ";
-        std::cerr << "\n";
-    }
+    // if (DEEPDEBUG) {
+    //     std::cerr << "--- [FIX] Applying protection for argument vregs that live across calls: ";
+    //     for(unsigned v : live_across_call_vregs) std::cerr << regIdToString(v) << " ";
+    //     std::cerr << "\n";
+    // }
 
     // 获取所有调用者保存寄存器
     const auto& caller_saved_int = getCallerSavedIntRegs();
@@ -224,7 +224,7 @@ void RISCv64RegAlloc::protectCrossCallVRegs() {
     const unsigned offset = static_cast<unsigned>(PhysicalReg::PHYS_REG_START_ID);
 
     // 为每个确认跨越call的vreg，添加与所有调用者保存寄存器的冲突
-    for (unsigned vreg : live_across_call_vregs) {
+    for (unsigned vreg : vregs_to_protect_potentially) {
         if (isFPVReg(vreg)) { // 如果是浮点vreg
             for (auto preg : caller_saved_fp) {
                 addEdge(vreg, offset + static_cast<unsigned>(preg));
diff --git a/src/midend/Pass/Pass.cpp b/src/midend/Pass/Pass.cpp
index 0678e4e..a077645 100644
--- a/src/midend/Pass/Pass.cpp
+++ b/src/midend/Pass/Pass.cpp
@@ -181,19 +181,19 @@ void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR
         printPasses();
       }
       
-      // this->clearPasses();
-      // this->addPass(&LoopStrengthReduction::ID);
-      // this->run();
+      this->clearPasses();
+      this->addPass(&LoopStrengthReduction::ID);
+      this->run();
 
       if(DEBUG) {
         std::cout << "=== IR After Loop Normalization, and Strength Reduction Optimizations ===\n";
         printPasses();
       }
 
-      // // 全局强度削弱优化，包括代数优化和魔数除法
-      // this->clearPasses();
-      // this->addPass(&GlobalStrengthReduction::ID);
-      // this->run();
+      // 全局强度削弱优化，包括代数优化和魔数除法
+      this->clearPasses();
+      this->addPass(&GlobalStrengthReduction::ID);
+      this->run();
 
       if(DEBUG) {
         std::cout << "=== IR After Global Strength Reduction Optimizations ===\n";