diff --git a/CMakeLists.txt b/CMakeLists.txt
index d65578f4c0c5c180baee26f6ad37c5b561b9f0bd..e505a456b6ed56aa5df01d803f1dabd2ff7c38c8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,10 +7,12 @@ endif()
 # 加载cmake中函数和变量
 include(cmake/utils.cmake)
 
-project(SCNUcc LANGUAGES CXX)
+project(SCNUcc LANGUAGES CXX C)
 
 add_subdirectory(frontend)
 
+add_library(sysYarm STATIC test_cases/lib/sylib.c)
+
 #add_executable(test test.cpp)
 #add_subdirectory(midend)
 #add_subdirectory(backend)
diff --git a/dependencies/lib/libsysYarm.a b/dependencies/lib/libsysYarm.a
new file mode 100644
index 0000000000000000000000000000000000000000..6f92d2cd649e97d4bff5e391f121fe4ba2486804
Binary files /dev/null and b/dependencies/lib/libsysYarm.a differ
diff --git a/frontend/include/MyVisitor.h b/frontend/include/MyVisitor.h
index b957ef84b40488e3f1762575574d99c3c74e263f..bb60e2cee21b9956babcb38fd3a9598212c9299e 100644
--- a/frontend/include/MyVisitor.h
+++ b/frontend/include/MyVisitor.h
@@ -227,8 +227,9 @@ private:
   std::vector<std::shared_ptr<ControlFlowGraph>> cfgs_;
   std::map<std::string, IRPtr> gbl_vars;
   std::shared_ptr<GblInitBlock> gbl_init_blk;
-  std::vector<std::shared_ptr<BRIR>> false_list;  // 真出口链
-  std::vector<std::shared_ptr<BRIR>> true_list;  // 假出口链
+  // 真假出口链和backpatch的设计可以参考https://gitlab.eduxiji.net/T202410574202994/scnucc/-/issues/30
+  std::vector<std::vector<std::shared_ptr<BRIR>>> false_list;  // 真出口链
+  std::vector<std::vector<std::shared_ptr<BRIR>>> true_list;  // 假出口链
   BLOCK::BLOCK return_flag_; // 这个block有没有被提前return掉
   std::shared_ptr<Block> return_block_;  // ret
   std::vector<WhileBlocks> while_list_; // 当前处于的while循环0:entry 1: body 2:exit
diff --git a/frontend/src/ExpVisitor.cpp b/frontend/src/ExpVisitor.cpp
index 6f79dc8ebb9f4af44098f5a3eb51384f7e34469a..ab5b160d66416aa47d02ea23eb6252904703d67f 100644
--- a/frontend/src/ExpVisitor.cpp
+++ b/frontend/src/ExpVisitor.cpp
@@ -29,13 +29,13 @@ std::any MyVisitor::visitExp(SysYParser::ExpContext *ctx) {
 
     // runtime库头文件有计时函数的宏定义，需要改下名字
 
-    if(func_name == "stoptime") func_name = "_sysy_stoptime";
-    else if(func_name == "starttime") func_name = "_sysy_starttime";
+    if (func_name == "stoptime") func_name = "_sysy_stoptime";
+    else if (func_name == "starttime") func_name = "_sysy_starttime";
 
     auto func_symbol = sym_table_->FuncLookUp(func_name);
-    
+
     // 特判计时函数
-    if(func_name=="_sysy_stoptime" || func_name =="_sysy_starttime"){
+    if (func_name == "_sysy_stoptime" || func_name == "_sysy_starttime") {
       int lineno = ctx->getStart()->getLine();
       auto call_ir = std::make_shared<CallIR>(IRTYPE::IR_VOID, func_name, func_symbol->GetAllParams());
       IRPtr numIR = std::make_shared<ConstantIR>(lineno, IRTYPE::IR_CONST_INT);
@@ -63,23 +63,23 @@ std::any MyVisitor::visitExp(SysYParser::ExpContext *ctx) {
     // freopen("../debug.txt","w",stdout);
 
     // putf的第二个参数是可变参数，扫描后才能确定，因此在这里添加
-    if(func_name == "putf"){
+    if (func_name == "putf") {
       //重置putf的funcsymbol
       func_symbol->ResetParams();
       func_symbol->PushPackParam(Type(BaseType::STRING, SymKind::VAR, false, false));
       // %d %c %f 
       std::string rpstring = ctx->funcRParams()->string()->getText();
-      rpstring = rpstring.substr(1,rpstring.size()-2); //去掉双引号
+      rpstring = rpstring.substr(1, rpstring.size() - 2); //去掉双引号
       Util::PushBackgstring(rpstring); //将第一个实参(即字符串)加进全局字符串中
-      
-      for(int i=0;i<rpstring.size()-1;i++){
-        if(rpstring[i]=='%'){
-          char t = rpstring[i+1];
-          
-          if(t == 'd'){func_symbol->PushPackParam(Type(BaseType::INT, SymKind::VAR, false, false));}
-          else if(t == 'c'){func_symbol->PushPackParam(Type(BaseType::INT, SymKind::VAR, false, false));}
-          else if(t == 'f'){func_symbol->PushPackParam(Type(BaseType::FLOAT, SymKind::VAR, false, false));}
-          else{
+
+      for (int i = 0; i < rpstring.size() - 1; i++) {
+        if (rpstring[i] == '%') {
+          char t = rpstring[i + 1];
+
+          if (t == 'd') { func_symbol->PushPackParam(Type(BaseType::INT, SymKind::VAR, false, false)); }
+          else if (t == 'c') { func_symbol->PushPackParam(Type(BaseType::INT, SymKind::VAR, false, false)); }
+          else if (t == 'f') { func_symbol->PushPackParam(Type(BaseType::FLOAT, SymKind::VAR, false, false)); }
+          else {
             std::string msg = "Error: unsupported type for putf";
             throw std::runtime_error(msg);
           }
@@ -88,9 +88,9 @@ std::any MyVisitor::visitExp(SysYParser::ExpContext *ctx) {
     }
 
 
-      // freopen("/dev/tty", "a+", stdout);
-      /* dddddddddddddddddddddddddddeeeeeeeeeeeeeeeeebbbbbbbbbbbbbbbbbbbbuuuuuuuuuuuuuuuugggggggggggg */
-    
+    // freopen("/dev/tty", "a+", stdout);
+    /* dddddddddddddddddddddddddddeeeeeeeeeeeeeeeeebbbbbbbbbbbbbbbbbbbbuuuuuuuuuuuuuuuugggggggggggg */
+
 
     std::vector<Type> all_params = func_symbol->GetAllParams();
     auto call_ir = std::make_shared<CallIR>(ret_type, func_name, all_params);
@@ -106,7 +106,7 @@ std::any MyVisitor::visitExp(SysYParser::ExpContext *ctx) {
           LoadVar(exp_ir);  // 如果是GEP，需要load
           ZeroExtend(exp_ir);
           // 这里先只考虑类型转换
-          if (all_params[i].base_type_ == BaseType::INT) { 
+          if (all_params[i].base_type_ == BaseType::INT) {
             Float2Int(exp_ir);
           } else if (all_params[i].base_type_ == BaseType::FLOAT) {
             Int2Float(exp_ir);
@@ -154,7 +154,8 @@ std::any MyVisitor::visitLVal(SysYParser::LValContext *ctx) {
   // 在当前作用域查找
   std::shared_ptr<Scope> cur_scope = sym_table_->GetCurrentScope();
   // 这个肯定是VarSymbol 
-  std::shared_ptr<VarSymbol> var_sym = std::dynamic_pointer_cast<VarSymbol>(cur_scope->VarLookUp(var_name, SearchScope::CUR_SCOPE));
+  std::shared_ptr<VarSymbol> var_sym = std::dynamic_pointer_cast<VarSymbol>(
+          cur_scope->VarLookUp(var_name, SearchScope::CUR_SCOPE));
   // 如果这个作用域没找到，就可以去到父作用域找
   if (var_sym == nullptr) {
     var_sym = std::dynamic_pointer_cast<VarSymbol>(cur_scope->VarLookUp(var_name, SearchScope::ALL_SCOPE));
@@ -171,7 +172,8 @@ std::any MyVisitor::visitLVal(SysYParser::LValContext *ctx) {
       auto exp_ir = std::any_cast<IRPtr>(visit(ctx->exp(i)));
       LoadVar(exp_ir);
       indices.push_back(exp_ir);
-      IRPtr new_gep = std::make_shared<GEPIR>(type == BaseType::INT ? IRTYPE::IR_I32 : IRTYPE::IR_FLOAT, var_sym, indices);
+      IRPtr new_gep = std::make_shared<GEPIR>(type == BaseType::INT ? IRTYPE::IR_I32 : IRTYPE::IR_FLOAT, var_sym,
+                                              indices);
       if (i == 0) {
         new_gep->AddOprnd(var_ir);  // 加入数组的声明IR
       } else {
@@ -179,7 +181,7 @@ std::any MyVisitor::visitLVal(SysYParser::LValContext *ctx) {
       }
       gep = new_gep;
       blk->AddStatement(gep);
-    } 
+    }
     if (gep == nullptr) { // 此时只给了数组名
       indices.push_back(std::make_shared<ConstantIR>(0, IRTYPE::IR_CONST_INT));
       gep = std::make_shared<GEPIR>(type == BaseType::INT ? IRTYPE::IR_I32 : IRTYPE::IR_FLOAT, var_sym, indices);
@@ -188,8 +190,8 @@ std::any MyVisitor::visitLVal(SysYParser::LValContext *ctx) {
     }
     return gep;
   } else {
-      auto var_ir = std::any_cast<IRPtr>(MyVisitor::ReadVariable(var_name));
-      return var_ir;
+    auto var_ir = std::any_cast<IRPtr>(MyVisitor::ReadVariable(var_name));
+    return var_ir;
   }
   return nullptr;
 }
@@ -210,7 +212,7 @@ std::any MyVisitor::visitUnaryExp(SysYParser::ExpContext *ctx) {
     // +a +b
     // load一下
     return IR;
-    
+
   } else if (ctx->unaryOp()->SUB()) {
     // 如果是负数
     // a
@@ -372,7 +374,7 @@ std::any MyVisitor::visitCond(SysYParser::CondContext *ctx) {
     LoadVar(ir);
     // 先0扩展
     ZeroExtend(ir);
-    
+
     if ((logic_parent && (logic_parent->op->getText() == "&&" || logic_parent->op->getText() == "||"))
         || (stmt_parent && (stmt_parent->IF() != nullptr || stmt_parent->WHILE() != nullptr))) {
 
@@ -401,15 +403,17 @@ std::any MyVisitor::visitCond(SysYParser::CondContext *ctx) {
       // 新建一个BRIR
       auto br = std::make_shared<BRIR>(IRTYPE::IR_I1, blk);
       br->AddOprnd(cmpIR);
-      true_list.push_back(br);
-      false_list.push_back(br);
+      true_list.emplace_back();
+      true_list.back().push_back(br);
+      false_list.emplace_back();
+      false_list.back().push_back(br);
       blk->AddStatement(br);
 
       return cmpIR;
     } else {
       return ir;
     }
-  } else if (ctx->op->getText() == "&&" || ctx->op->getText() == "||") {  // 逻辑与运算
+  } else if (ctx->op->getText() == "&&" || ctx->op->getText() == "||") {  // 逻辑运算
     auto cfg = cfgs_.back();
     auto left_block = cfg->GetLastBlock();
     // 构造第一个cond block
@@ -417,9 +421,23 @@ std::any MyVisitor::visitCond(SysYParser::CondContext *ctx) {
     // back patch
     auto right_block = std::make_shared<Block>(sym_table_, ctx->while_entry, ctx->while_exit);
     if (ctx->op->getText() == "&&") {
-      backPatch(true_list, right_block, true);
+      backPatch(true_list.back(), right_block, true);
+      true_list.pop_back();
+      // false_list没有办法处理就合并到父节点的false_list中，让父节点去处理
+      // 避免出现这种问题的问题是https://gitlab.eduxiji.net/T202410574202994/scnucc/-/issues/30
+      if (false_list.size() >= 2) {
+        auto& parent_list = false_list[false_list.size() - 2];
+        parent_list.insert(parent_list.end(), false_list.back().begin(), false_list.back().end());
+        false_list.pop_back();
+      }
     } else {
-      backPatch(false_list, right_block, false);
+      backPatch(false_list.back(), right_block, false);
+      false_list.pop_back();
+      if (true_list.size() >= 2) {
+        auto& parent_list = true_list[true_list.size() - 2];
+        parent_list.insert(parent_list.end(), true_list.back().begin(), true_list.back().end());
+        true_list.pop_back();
+      }
     }
     // 在back patch中已经完成了连接，所以只需要AddBlock
     cfg->AddBlock(right_block);
@@ -428,7 +446,20 @@ std::any MyVisitor::visitCond(SysYParser::CondContext *ctx) {
     // 构造第二个cond block，产生的IR将会放在right_block中
     visit(ctx->cond(1));
 
+    if (false_list.size() >= 2) {
+      auto& parent_list = false_list[false_list.size() - 2];
+      false_list[false_list.size() - 2].insert(parent_list.end(), false_list.back().begin(), false_list.back().end());
+      false_list.pop_back();
+    }
+
+    if (true_list.size() >= 2) {
+      auto& parent_list = true_list[true_list.size() - 2];
+      parent_list.insert(parent_list.end(), true_list.back().begin(), true_list.back().end());
+      true_list.pop_back();
+    }
+
     // 如果父节点是比较运算符，那么需要返回一个phi语句
+    // 处理的是" (con1) == (cond2) " 这种情况
     auto parent = dynamic_cast<SysYParser::CondContext *>(ctx->parent);
     if (parent && !(parent->op->getText() == "&&" || parent->op->getText() == "||")) {
       return genPhiForCond(ctx);
@@ -443,8 +474,10 @@ std::any MyVisitor::visitCond(SysYParser::CondContext *ctx) {
       auto br = std::make_shared<BRIR>(IRTYPE::IR_I1, blk);
       blk->AddStatement(br);
       br->AddOprnd(cmp_ir);
-      true_list.push_back(br);
-      false_list.push_back(br);
+      true_list.emplace_back();
+      false_list.emplace_back();
+      true_list.back().push_back(br);
+      false_list.back().push_back(br);
     }
     return cmp_ir;
   }
diff --git a/frontend/src/MyVisitor.cpp b/frontend/src/MyVisitor.cpp
index da0aa9c8fa934baac0255d3ff287733370bfdf33..18e2ccf15f8c6facfa52b50beb27596b71824495 100644
--- a/frontend/src/MyVisitor.cpp
+++ b/frontend/src/MyVisitor.cpp
@@ -618,8 +618,10 @@ std::any MyVisitor::visitStmt(SysYParser::StmtContext *ctx) {
     // 访问条件表达式
     visit(ctx->cond());
     // 在back patch中，已经完成了if_then与if_entry的许多block的连接
-    backPatch(true_list, if_then, true);
-    backPatch(false_list, if_else == nullptr ? if_end : if_else, false);
+    backPatch(true_list.back(), if_then, true);
+    backPatch(false_list.back(), if_else == nullptr ? if_end : if_else, false);
+    true_list.pop_back();
+    false_list.pop_back();
     if_entry->Seal();
 
     // 构造then part
@@ -687,8 +689,10 @@ std::any MyVisitor::visitStmt(SysYParser::StmtContext *ctx) {
         blk_before_entry->AddStatement(br1);
         cfg->Concat(while_entry);
         visit(ctx->cond());
-        backPatch(true_list, while_body, true);
-        backPatch(false_list, while_exit, false);
+        backPatch(true_list.back(), while_body, true);
+        backPatch(false_list.back(), while_exit, false);
+        true_list.pop_back();
+        false_list.pop_back();
         // 到这里entry还没seal
 
         while_body->Seal();  // 到这里body的前驱已经完全
diff --git a/frontend/src/PrivateVisitor.cpp b/frontend/src/PrivateVisitor.cpp
index 7b68a5137ba00aaae7639cc7b4fd7dd48edabac1..5bb6c90c29d85cda1adff8a2864390be01c3b5fd 100644
--- a/frontend/src/PrivateVisitor.cpp
+++ b/frontend/src/PrivateVisitor.cpp
@@ -378,8 +378,10 @@ auto MyVisitor::backPatch(std::vector<std::shared_ptr<BRIR>> &list, const std::s
 auto MyVisitor::genPhiForCond(SysYParser::CondContext *ctx) -> IRPtr {
   // back patch
   auto next_block = std::make_shared<Block>(sym_table_, ctx->while_entry, ctx->while_exit);
-  backPatch(true_list, next_block, true);
-  backPatch(false_list, next_block, false);
+  backPatch(true_list.back(), next_block, true);
+  backPatch(false_list.back(), next_block, false);
+  true_list.pop_back();
+  false_list.pop_back();
   // back patch 找到了next_block的所有父block，所以这里只需要AddBlock
   cfgs_.back()->AddBlock(next_block);
   next_block->Seal();