--- include/ir/IR.h
+++ include/ir/IR.h
@@ -93,6 +93,7 @@
 class Type {
  public:
-  enum class Kind { Void, Int32, PtrInt32 };
+  enum class Kind { Void, Int1, Int32, PtrInt32 };
   explicit Type(Kind k);
   // 使用静态共享对象获取类型。
   // 同一类型可直接比较返回值是否相等，例如：
   // Type::GetInt32Type() == Type::GetInt32Type()
   static const std::shared_ptr<Type>& GetVoidType();
+  static const std::shared_ptr<Type>& GetInt1Type();
   static const std::shared_ptr<Type>& GetInt32Type();
   static const std::shared_ptr<Type>& GetPtrInt32Type();
   Kind GetKind() const;
   bool IsVoid() const;
+  bool IsInt1() const;
   bool IsInt32() const;
   bool IsPtrInt32() const;
@@ -118,6 +119,7 @@
   const std::string& GetName() const;
   void SetName(std::string n);
   bool IsVoid() const;
+  bool IsInt1() const;
   bool IsInt32() const;
   bool IsPtrInt32() const;
   bool IsConstant() const;
@@ -153,7 +155,9 @@
 
 // 后续还需要扩展更多指令类型。
-// enum class Opcode { Add, Sub, Mul, Alloca, Load, Store, Ret };
-enum class Opcode { Add, Sub, Mul, Div, Mod, Neg, Alloca, Load, Store, Ret };
+enum class Opcode { Add, Sub, Mul, Div, Mod, Neg, Alloca, Load, Store, Ret, Cmp, Zext, Br, CondBr };
+
+enum class CmpOp { Eq, Ne, Lt, Gt, Le, Ge };
 
 // User 是所有“会使用其他 Value 作为输入”的 IR 对象的抽象基类。
@@ -231,6 +235,33 @@
   Value* GetPtr() const;
 };
 
+class CmpInst : public Instruction {
+ public:
+  CmpInst(CmpOp cmp_op, Value* lhs, Value* rhs, std::string name);
+  CmpOp GetCmpOp() const;
+  Value* GetLhs() const;
+  Value* GetRhs() const;
+ private:
+  CmpOp cmp_op_;
+};
+
+class ZextInst : public Instruction {
+ public:
+  ZextInst(std::shared_ptr<Type> dest_ty, Value* val, std::string name);
+  Value* GetValue() const;
+};
+
+class BranchInst : public Instruction {
+ public:
+  BranchInst(BasicBlock* dest);
+  BasicBlock* GetDest() const;
+};
+
+class CondBranchInst : public Instruction {
+ public:
+  CondBranchInst(Value* cond, BasicBlock* true_bb, BasicBlock* false_bb);
+  Value* GetCond() const;
+  BasicBlock* GetTrueBlock() const;
+  BasicBlock* GetFalseBlock() const;
+};
+
 // BasicBlock 已纳入 Value 体系，便于后续向更完整 IR 类图靠拢。
@@ -315,6 +346,10 @@
   LoadInst* CreateLoad(Value* ptr, const std::string& name);
   StoreInst* CreateStore(Value* val, Value* ptr);
   ReturnInst* CreateRet(Value* v);
+  CmpInst* CreateCmp(CmpOp op, Value* lhs, Value* rhs, const std::string& name);
+  ZextInst* CreateZext(Value* val, const std::string& name);
+  BranchInst* CreateBr(BasicBlock* dest);
+  CondBranchInst* CreateCondBr(Value* cond, BasicBlock* true_bb, BasicBlock* false_bb);
 
  private: