diff --git a/examples/alignof.c b/examples/alignof.c
index 6e12fb7..5e36459 100644
--- a/examples/alignof.c
+++ b/examples/alignof.c
@@ -1,3 +1,3 @@
 int main() {
-    return _Alignof(const int);
+    return _Alignof(const int) == 4;
 }
diff --git a/examples/bar.c b/examples/bar.c
index 140aad2..4cd8b0b 100644
--- a/examples/bar.c
+++ b/examples/bar.c
@@ -4,3 +4,7 @@ int bar(int x, int y, int z){
     if (x == y) { return y; }
     else { return z; }
 }
+
+int main() {
+    return 1;
+}
diff --git a/examples/comma.c b/examples/comma.c
index ddb618c..294bf93 100644
--- a/examples/comma.c
+++ b/examples/comma.c
@@ -2,5 +2,5 @@ int main()
 {
     int y = 2;
     int x = (y += 2, 2, y + 3);
-    return x;
+    return x == 7;
 }
diff --git a/examples/cond.c b/examples/cond.c
index 900be5e..e12f409 100644
--- a/examples/cond.c
+++ b/examples/cond.c
@@ -2,5 +2,5 @@ int main()
 {
     int y = 1;
     int x = 0;
-    return (x == y) ? 2 : 5;
+    return ((x == y) ? 2 : 5) == 5;
 }
diff --git a/examples/fib2.c b/examples/fib2.c
index 61f1d78..94b0cda 100644
--- a/examples/fib2.c
+++ b/examples/fib2.c
@@ -5,3 +5,7 @@ int (fibonacci)(int n) {
 
     return fibonacci(n - 2) + fibonacci(n - 1);
 }
+
+int main() {
+    return fibonacci(9) == 34;
+}
diff --git a/examples/fib3.c b/examples/fib3.c
index a2aa1f7..c2d2b14 100644
--- a/examples/fib3.c
+++ b/examples/fib3.c
@@ -16,5 +16,5 @@ int fibonacci(int n) {
 }
 
 int main() {
-    return fibonacci(9);
+    return fibonacci(9) == 34;
 }
diff --git a/examples/fib4.c b/examples/fib4.c
index ecd45ed..9186084 100644
--- a/examples/fib4.c
+++ b/examples/fib4.c
@@ -18,5 +18,5 @@ int fibonacci(int n) {
 }
 
 int main() {
-    return fibonacci(9);
+    return fibonacci(9) == 34;
 }
diff --git a/examples/fib5.c b/examples/fib5.c
index 534c526..08b4546 100644
--- a/examples/fib5.c
+++ b/examples/fib5.c
@@ -18,5 +18,5 @@ int fibonacci(int n) {
 }
 
 int main() {
-    return fibonacci(9);
+    return fibonacci(9) == 34;
 }
diff --git a/examples/fibonacci.c b/examples/fibonacci.c
index f0767de..a65fe3a 100644
--- a/examples/fibonacci.c
+++ b/examples/fibonacci.c
@@ -7,5 +7,5 @@ int fibonacci(int n) {
 }
 
 int main() {
-    return fibonacci(9);
+    return fibonacci(9) == 34;
 }
diff --git a/examples/foo.c b/examples/foo.c
index b831a1a..879caed 100644
--- a/examples/foo.c
+++ b/examples/foo.c
@@ -4,5 +4,5 @@ int foo(int x, int y, int z){
 }
 
 int main() {
-    return foo(0, 1, -1);
+    return foo(0, 1, -1) == -1;
 }
diff --git a/examples/foo2.c b/examples/foo2.c
index 801ffdd..150600b 100644
--- a/examples/foo2.c
+++ b/examples/foo2.c
@@ -5,5 +5,5 @@ int main() {
         int k = 0;
     }
     
-    return 0;
+    return 1;
 }
diff --git a/examples/foo3.c b/examples/foo3.c
index a5ebf07..1392714 100644
--- a/examples/foo3.c
+++ b/examples/foo3.c
@@ -5,7 +5,7 @@ int foo(int, int k);
 int main() {
     int i = g;
     
-    return foo(i, i);
+    return foo(i, i) == 30;
 }
 
 int foo(int i, int j) {
diff --git a/examples/foo4.c b/examples/foo4.c
index c690400..bbe4a38 100644
--- a/examples/foo4.c
+++ b/examples/foo4.c
@@ -11,5 +11,5 @@ int (* (* foo3())())(int, int, int){
 }
 
 int main() {
-  return foo3()()(2, 2, 2);
+  return foo3()()(2, 2, 2) == 6;
 }
diff --git a/examples/for_continue_break.c b/examples/for_continue_break.c
new file mode 100644
index 0000000..f15b59a
--- /dev/null
+++ b/examples/for_continue_break.c
@@ -0,0 +1,19 @@
+int foo() {
+    int sum = 0;
+
+    for(int i = 0; ;) {
+        if(i == 5) break;
+        if(i == 3) {
+            i++;
+            continue;
+        }
+        sum += i;
+        i++;
+    }
+
+    return sum;
+}
+
+int main() {
+    return foo() == 7;
+}
diff --git a/examples/temp2.c b/examples/hw1/temp2.c
similarity index 100%
rename from examples/temp2.c
rename to examples/hw1/temp2.c
diff --git a/examples/negate.c b/examples/negate.c
index 25356be..d38f42d 100644
--- a/examples/negate.c
+++ b/examples/negate.c
@@ -4,5 +4,5 @@ int foo(int x, int y, int z){
 }
 
 int main() {
-    return foo(0, 1, -1);
+    return foo(0, 1, -1) == 1;
 }
diff --git a/examples/pointer.c b/examples/pointer.c
index 39067cd..21bebce 100644
--- a/examples/pointer.c
+++ b/examples/pointer.c
@@ -11,5 +11,5 @@ int main(){
     *&*foo(*p2) += 1;
     *foo(p3) += 1;
     
-    return a;
+    return a == 3;
 }
diff --git a/examples/return_void.c b/examples/return_void.c
index 93f284c..fc64e3d 100644
--- a/examples/return_void.c
+++ b/examples/return_void.c
@@ -3,5 +3,5 @@ void foo() {
 
 int main() {
     foo();
-    return 0;
+    return 1;
 }
diff --git a/examples/simple.c b/examples/simple.c
index a382e8e..29fc1ed 100644
--- a/examples/simple.c
+++ b/examples/simple.c
@@ -1,4 +1,5 @@
 int main()
 {
     int x = 1;
+    return 1;
 }
diff --git a/examples/simple_for.c b/examples/simple_for.c
index 552fd1a..6073bcc 100644
--- a/examples/simple_for.c
+++ b/examples/simple_for.c
@@ -5,5 +5,5 @@ int main()
     for (i = 0; i < 11; ++i) { 
         sum += i; 
     }
-    return sum;
+    return sum == 55;
 }
diff --git a/examples/simple_if.c b/examples/simple_if.c
index 4429714..46dd19a 100644
--- a/examples/simple_if.c
+++ b/examples/simple_if.c
@@ -5,3 +5,7 @@ int (fibonacci)(int n) {
 
     return fibonacci(n - 2) + fibonacci(n - 1);
 }
+
+int main() {
+    return 1;
+}
diff --git a/examples/sizeof.c b/examples/sizeof.c
index 2520d24..155c77f 100644
--- a/examples/sizeof.c
+++ b/examples/sizeof.c
@@ -1,3 +1,3 @@
 int main() {
-    return sizeof(const int);
+    return sizeof(const int) == 4;
 }
diff --git a/examples/switch.c b/examples/switch.c
index e0d2209..8f4164c 100644
--- a/examples/switch.c
+++ b/examples/switch.c
@@ -16,5 +16,5 @@ int main() {
         }
     }
 
-    return b;
+    return b == 2;
 }
diff --git a/examples/temp.c b/examples/temp.c
index 6acc0f9..fcc114c 100644
--- a/examples/temp.c
+++ b/examples/temp.c
@@ -3,3 +3,7 @@ int fibonacci(int n) {
         return n;
     }
 }
+
+int main() {
+    return 1;
+}
diff --git a/examples/while_continue_break.c b/examples/while_continue_break.c
new file mode 100644
index 0000000..6e51fb3
--- /dev/null
+++ b/examples/while_continue_break.c
@@ -0,0 +1,21 @@
+int foo() {
+    int sum = 0;
+    int i = 0;
+
+    while(i < 10) {
+        if(i == 3) {
+            i++;
+            continue;
+        }
+        sum += i;
+        i++;
+
+        if(i == 5) break;
+    }
+
+    return sum;
+}
+
+int main() {
+    return foo() == 7;
+}
diff --git a/src/ir.rs b/src/ir.rs
index bb8e052..8ac9a1f 100644
--- a/src/ir.rs
+++ b/src/ir.rs
@@ -1058,7 +1058,7 @@ impl HasDtype for Instruction {
     }
 }
 
-#[derive(Debug, PartialEq, Eq, Hash, Clone)]
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
 pub struct BlockId(pub usize);
 
 impl fmt::Display for BlockId {
diff --git a/src/run_ir.rs b/src/run_ir.rs
index 511b96c..eb3b786 100644
--- a/src/run_ir.rs
+++ b/src/run_ir.rs
@@ -78,7 +78,7 @@ pub enum InterpreterError {
         display = "{}:{}:{} / Undef value cannot be used as an operand",
         func_name, bid, iid
     )]
-    Undef {
+    Misc {
         func_name: String,
         bid: BlockId,
         iid: usize,
@@ -198,6 +198,9 @@ mod calculator {
             (ast::BinaryOperator::Less, Value::Int(lhs), Value::Int(rhs)) => {
                 Ok(Value::Bool(lhs < rhs))
             }
+            (ast::BinaryOperator::GreaterOrEqual, Value::Int(lhs), Value::Int(rhs)) => {
+                Ok(Value::Bool(lhs >= rhs))
+            }
             _ => todo!(),
         }
     }
@@ -214,6 +217,16 @@ mod calculator {
             _ => todo!(),
         }
     }
+
+    pub fn calculate_typecast(value: &Value, dtype: &crate::ir::Dtype) -> Result<Value, ()> {
+        match (value, dtype) {
+            (Value::Int(_), crate::ir::Dtype::Int { .. }) => Ok(value.clone()),
+            (Value::Bool(b), crate::ir::Dtype::Int { .. }) => {
+                Ok(Value::Int(if *b { 1 } else { 0 }))
+            }
+            _ => todo!("calculate_typecast ({:?}) {:?}", dtype, value),
+        }
+    }
 }
 
 // TODO: allocation fields will be added in the future
@@ -250,7 +263,7 @@ impl<'i> State<'i> {
         // Create State
         let mut state = State {
             global_map: GlobalMap::default(),
-            stack_frame: StackFrame::new(func_def.bid_init.clone(), func_name, func_def),
+            stack_frame: StackFrame::new(func_def.bid_init, func_name, func_def),
             stack: Vec::new(),
             memory: Vec::new(),
             ir,
@@ -351,7 +364,7 @@ impl<'i> State<'i> {
             .stack_frame
             .func_def
             .blocks
-            .get(&self.stack_frame.pc.bid.clone())
+            .get(&self.stack_frame.pc.bid)
             .expect("block matched with `bid` must be exist");
 
         if block.instructions.len() == self.stack_frame.pc.iid {
@@ -378,8 +391,7 @@ impl<'i> State<'i> {
                 self.stack_frame = prev_stack_frame;
 
                 // create temporary register to write return value
-                let register =
-                    RegisterId::temp(self.stack_frame.pc.bid.clone(), self.stack_frame.pc.iid);
+                let register = RegisterId::temp(self.stack_frame.pc.bid, self.stack_frame.pc.iid);
                 self.register_write(register, value);
                 self.stack_frame.pc.increment();
             }
@@ -392,7 +404,7 @@ impl<'i> State<'i> {
     ) -> Result<Option<Value>, InterpreterError> {
         match block_exit {
             BlockExit::Jump { bid } => {
-                self.stack_frame.pc = Pc::new(bid.clone());
+                self.stack_frame.pc = Pc::new(*bid);
                 Ok(None)
             }
             BlockExit::ConditionalJump {
@@ -403,11 +415,7 @@ impl<'i> State<'i> {
                 let value = self.get_value(condition.clone())?;
                 let value = value.get_bool().expect("`condition` must be `Value::Bool`");
 
-                self.stack_frame.pc = Pc::new(if value {
-                    bid_then.clone()
-                } else {
-                    bid_else.clone()
-                });
+                self.stack_frame.pc = Pc::new(if value { *bid_then } else { *bid_else });
                 Ok(None)
             }
             BlockExit::Switch {
@@ -421,10 +429,10 @@ impl<'i> State<'i> {
                 let bid_next = cases
                     .iter()
                     .find(|(c, _)| value == self.constant_to_value(c.clone()))
-                    .map(|(_, bid)| bid.clone())
-                    .unwrap_or_else(|| default.clone());
+                    .map(|(_, bid)| bid)
+                    .unwrap_or_else(|| default);
 
-                self.stack_frame.pc = Pc::new(bid_next);
+                self.stack_frame.pc = Pc::new(*bid_next);
 
                 Ok(None)
             }
@@ -443,9 +451,9 @@ impl<'i> State<'i> {
                 let rhs = self.get_value(rhs.clone())?;
 
                 calculator::calculate_binary_operator_expression(&op, lhs, rhs).map_err(|_| {
-                    InterpreterError::Undef {
+                    InterpreterError::Misc {
                         func_name: self.stack_frame.func_name.clone(),
-                        bid: self.stack_frame.pc.bid.clone(),
+                        bid: self.stack_frame.pc.bid,
                         iid: self.stack_frame.pc.iid,
                     }
                 })?
@@ -454,9 +462,9 @@ impl<'i> State<'i> {
                 let operand = self.get_value(operand.clone())?;
 
                 calculator::calculate_unary_operator_expression(&op, operand).map_err(|_| {
-                    InterpreterError::Undef {
+                    InterpreterError::Misc {
                         func_name: self.stack_frame.func_name.clone(),
-                        bid: self.stack_frame.pc.bid.clone(),
+                        bid: self.stack_frame.pc.bid,
                         iid: self.stack_frame.pc.iid,
                     }
                 })?
@@ -502,7 +510,7 @@ impl<'i> State<'i> {
 
                 let args = self.preprocess_args(func_signature, args)?;
 
-                let stack_frame = StackFrame::new(func_def.bid_init.clone(), callee_name, func_def);
+                let stack_frame = StackFrame::new(func_def.bid_init, callee_name, func_def);
                 let prev_stack_frame = mem::replace(&mut self.stack_frame, stack_frame);
                 self.stack.push(prev_stack_frame);
 
@@ -512,10 +520,22 @@ impl<'i> State<'i> {
 
                 return Ok(None);
             }
-            _ => todo!("{:?} will be supported in the future", instruction),
+            Instruction::TypeCast {
+                value,
+                target_dtype,
+            } => {
+                let value = self.get_value(value.clone())?;
+                calculator::calculate_typecast(&value, target_dtype).map_err(|_| {
+                    InterpreterError::Misc {
+                        func_name: self.stack_frame.func_name.clone(),
+                        bid: self.stack_frame.pc.bid,
+                        iid: self.stack_frame.pc.iid,
+                    }
+                })?
+            }
         };
 
-        let register = RegisterId::temp(self.stack_frame.pc.bid.clone(), self.stack_frame.pc.iid);
+        let register = RegisterId::temp(self.stack_frame.pc.bid, self.stack_frame.pc.iid);
         self.register_write(register, result);
         self.stack_frame.pc.increment();
 
diff --git a/src/write_ir.rs b/src/write_ir.rs
index dd2937a..51151c5 100644
--- a/src/write_ir.rs
+++ b/src/write_ir.rs
@@ -104,7 +104,7 @@ impl WriteLine for (&BlockId, &Block) {
             writeln!(
                 write,
                 "{}:{} = {}",
-                RegisterId::temp(self.0.clone(), i),
+                RegisterId::temp(*self.0, i),
                 instr.dtype(),
                 instr.write_string()
             )?;
diff --git a/tests/ast_printer_test.rs b/tests/ast_printer_test.rs
deleted file mode 100644
index e071c68..0000000
--- a/tests/ast_printer_test.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use std::path::Path;
-
-use kecc::*;
-
-#[test]
-fn ast_printer_test() {
-    let mut parse = Parse::default();
-    let dir_path = Path::new("examples/");
-    let dir = dir_path.read_dir().expect("read_dir call failed");
-    for entry in dir {
-        let test_file = ok_or!(entry, continue);
-        let test_unit = parse.translate(&test_file.path().as_path()).expect(
-            &format!(
-                "parse failed {:?}",
-                test_file.path().into_os_string().to_str().unwrap()
-            )
-            .to_owned(),
-        );
-        write_c_test(&test_unit);
-    }
-}
diff --git a/tests/fuzz.py b/tests/fuzz.py
index d5f7c21..da9ff98 100644
--- a/tests/fuzz.py
+++ b/tests/fuzz.py
@@ -22,6 +22,7 @@ REPLACE_DICT = {
     "int16_t": "int",
     "int32_t": "int",
     "uint": "unsigned int",
+    "static ": "",
 }
 CSMITH_DIR = "csmith-2.3.0"
 
@@ -44,7 +45,12 @@ def generate(tests_dir, bin_file, runtime, file_name):
     A developer may customize the options to meet one's needs for testing.
     """
     global CSMITH_DIR
-    options = ["--no-builtins", "--no-safe-math", "--no-unions"]
+    options = [
+        "--no-argc", "--no-arrays", "--no-checksum",
+        "--no-jumps", "--no-longlong", "--no-int8",
+        "--no-uint8", "--no-safe-math", "--no-pointers",
+        "--no-structs", "--no-unions", "--no-builtins"
+    ]
     args = [bin_file] + options
     dst_path = os.path.join(runtime, file_name)
 
diff --git a/tests/ir_test.rs b/tests/ir_test.rs
deleted file mode 100644
index 2b63e94..0000000
--- a/tests/ir_test.rs
+++ /dev/null
@@ -1,68 +0,0 @@
-use kecc::run_ir::*;
-use kecc::*;
-use std::path::Path;
-
-// TODO: cover all examples in the future
-#[test]
-fn ir_interpreter_test() {
-    // Test toy example
-    assert_eq!(run_example("examples/foo.c"), Ok(Value::Int(-1)));
-
-    // Test toy example with negate unary operator
-    assert_eq!(run_example("examples/negate.c"), Ok(Value::Int(1)));
-
-    // Test fibonacci function with for-loop
-    assert_eq!(run_example("examples/fib3.c"), Ok(Value::Int(34)));
-
-    // Test fibonacci function with while-loop
-    assert_eq!(run_example("examples/fib4.c"), Ok(Value::Int(34)));
-
-    // Test fibonacci function with do-while-loop
-    assert_eq!(run_example("examples/fib5.c"), Ok(Value::Int(34)));
-
-    // Test fibonacci function with recursive function call
-    assert_eq!(run_example("examples/fibonacci.c"), Ok(Value::Int(34)));
-
-    // Test example with global variable
-    assert_eq!(run_example("examples/foo3.c"), Ok(Value::Int(30)));
-
-    // Test example with comma expressions
-    assert_eq!(run_example("examples/comma.c"), Ok(Value::Int(7)));
-
-    // Test example with complex function call
-    assert_eq!(run_example("examples/foo4.c"), Ok(Value::Int(6)));
-
-    // Test example with pointer
-    assert_eq!(run_example("examples/pointer.c"), Ok(Value::Int(3)));
-
-    // Test example with sizeof
-    assert_eq!(run_example("examples/sizeof.c"), Ok(Value::Int(4)));
-
-    // Test example with alignof
-    assert_eq!(run_example("examples/alignof.c"), Ok(Value::Int(4)));
-
-    // Test example with simple for statement
-    assert_eq!(run_example("examples/simple_for.c"), Ok(Value::Int(55)));
-
-    // Test example with conditional expression
-    assert_eq!(run_example("examples/cond.c"), Ok(Value::Int(5)));
-
-    // Test example with switch statement
-    assert_eq!(run_example("examples/switch.c"), Ok(Value::Int(2)));
-}
-
-fn run_example(example_path: &str) -> Result<Value, InterpreterError> {
-    let example_path = Path::new(example_path);
-    let unit = Parse::default()
-        .translate(&example_path)
-        .expect("parse failed");
-    let ir = Irgen::default()
-        .translate(&unit)
-        .expect("failed to generate ir");
-
-    // TODO: consider command line arguments in the future
-    // TODO: randomly generate argument values
-    let args = Vec::new();
-
-    run_ir(&ir, args)
-}
diff --git a/tests/test_examples.rs b/tests/test_examples.rs
new file mode 100644
index 0000000..1e5d98d
--- /dev/null
+++ b/tests/test_examples.rs
@@ -0,0 +1,47 @@
+use std::path::Path;
+
+use lang_c::ast::*;
+
+use kecc::run_ir::*;
+use kecc::*;
+
+fn test_dir<F>(path: &Path, f: F)
+where
+    F: Fn(&TranslationUnit),
+{
+    let mut parse = Parse::default();
+    let dir = path.read_dir().expect("read_dir call failed");
+    for entry in dir {
+        let entry = ok_or!(entry, continue);
+        let path = entry.path();
+        if path.is_dir() {
+            continue;
+        }
+
+        println!("[testing {:?}]", path);
+        let test_unit = parse.translate(&path.as_path()).expect(
+            &format!("parse failed {:?}", path.into_os_string().to_str().unwrap()).to_owned(),
+        );
+        f(&test_unit);
+    }
+}
+
+#[test]
+fn test_examples_write_c() {
+    test_dir(Path::new("examples/"), write_c_test);
+    test_dir(Path::new("examples/hw1"), write_c_test);
+}
+
+#[test]
+fn test_examples_irgen() {
+    test_dir(Path::new("examples/"), |test_unit| {
+        let ir = Irgen::default()
+            .translate(test_unit)
+            .expect("failed to generate ir");
+
+        // TODO: insert randomly generated command line arguments
+        let args = Vec::new();
+
+        assert_eq!(run_ir(&ir, args), Ok(Value::Int(1)));
+    });
+}