diff --git a/src/IR.cpp b/src/IR.cpp
index 913aac5..63d26d8 100644
--- a/src/IR.cpp
+++ b/src/IR.cpp
@@ -541,7 +541,8 @@ namespace sysy
   void Module::print(std::ostream &os) const
   {
     for (auto &value : children)
-      os << *value << '\n';
+      if (value->getName() != "getint" && value->getName() != "putint")
+        os << *value << '\n';
   }
 
   // ArrayValue *ArrayValue::get(Type *type, const vector<Value *> &values) {
diff --git a/src/SysYIRGenerator.cpp b/src/SysYIRGenerator.cpp
index 454ac5f..df28589 100644
--- a/src/SysYIRGenerator.cpp
+++ b/src/SysYIRGenerator.cpp
@@ -18,6 +18,14 @@ namespace sysy
     auto pModule = new Module();
     assert(pModule);
     module.reset(pModule);
+    // create function:getint
+    auto getint_type = Type::getFunctionType(Type::getIntType());
+    auto f_getint = pModule->createFunction("getint", getint_type);
+    symbols.insert("getint", f_getint);
+    // create function:putint
+    auto putint_type = Type::getFunctionType(Type::getVoidType(), vector<Type *>({Type::getIntType()}));
+    auto f_putint = pModule->createFunction("putint", putint_type);
+    symbols.insert("putint", f_putint);
     // generates globals and functions
     visitChildren(ctx);
     // return the IR module