diff --git a/cl/_testdata/fncall/out.ll b/cl/_testdata/fncall/out.ll
index aee35e31..180fd4cb 100644
--- a/cl/_testdata/fncall/out.ll
+++ b/cl/_testdata/fncall/out.ll
@@ -18,14 +18,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   %2 = call i64 @main.max(i64 1, i64 2)
-  ret void
+  ret i32 0
 }
 
 define i64 @main.max(i64 %0, i64 %1) {
diff --git a/cl/_testdata/importpkg/out.ll b/cl/_testdata/importpkg/out.ll
index 141afc03..dc48a001 100644
--- a/cl/_testdata/importpkg/out.ll
+++ b/cl/_testdata/importpkg/out.ll
@@ -27,7 +27,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -35,7 +35,7 @@ _llgo_0:
   call void @main.init()
   %2 = call i64 @"github.com/goplus/llgo/cl/internal/stdio.Max"(i64 2, i64 100)
   call void (ptr, ...) @printf(ptr @main.hello)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/cl/internal/stdio.init"()
diff --git a/cl/_testdata/method/out.ll b/cl/_testdata/method/out.ll
index 790e8b55..cbec5de4 100644
--- a/cl/_testdata/method/out.ll
+++ b/cl/_testdata/method/out.ll
@@ -42,7 +42,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -50,7 +50,7 @@ _llgo_0:
   call void @main.init()
   %2 = call i64 @"(main.T).Add"(i64 1, i64 2)
   call void (ptr, ...) @printf(ptr @main.format, i64 %2)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testdata/print/out.ll b/cl/_testdata/print/out.ll
index 2e91fdad..aba25c06 100644
--- a/cl/_testdata/print/out.ll
+++ b/cl/_testdata/print/out.ll
@@ -77,7 +77,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -205,7 +205,7 @@ _llgo_2:                                          ; preds = %_llgo_3, %_llgo_1,
   store %"github.com/goplus/llgo/internal/runtime.iface" %74, ptr %72, align 8
   %75 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %26, i64 16, i64 16, i64 0, i64 16, i64 16)
   call void @main.println(%"github.com/goplus/llgo/internal/runtime.Slice" %75)
-  ret void
+  ret i32 0
 
 _llgo_3:                                          ; preds = %_llgo_0
   br i1 true, label %_llgo_1, label %_llgo_2
@@ -488,10 +488,10 @@ _llgo_11:                                         ; preds = %_llgo_8
   %17 = fcmp olt double %16, 0.000000e+00
   br i1 %17, label %_llgo_14, label %_llgo_12
 
-_llgo_12:                                         ; preds = %_llgo_24, %_llgo_22, %_llgo_14, %_llgo_11
-  %18 = phi double [ %0, %_llgo_11 ], [ %36, %_llgo_22 ], [ %0, %_llgo_14 ], [ %42, %_llgo_24 ]
-  %19 = phi i64 [ 0, %_llgo_11 ], [ %32, %_llgo_22 ], [ 0, %_llgo_14 ], [ %41, %_llgo_24 ]
-  br label %_llgo_27
+_llgo_12:                                         ; preds = %_llgo_24, %_llgo_23, %_llgo_14, %_llgo_11
+  %18 = phi double [ %0, %_llgo_11 ], [ %39, %_llgo_23 ], [ %0, %_llgo_14 ], [ %42, %_llgo_24 ]
+  %19 = phi i64 [ 0, %_llgo_11 ], [ %32, %_llgo_23 ], [ 0, %_llgo_14 ], [ %41, %_llgo_24 ]
+  br label %_llgo_25
 
 _llgo_13:                                         ; preds = %_llgo_8
   %20 = fcmp olt double %0, 0.000000e+00
@@ -525,7 +525,7 @@ _llgo_18:                                         ; preds = %_llgo_20
   br label %_llgo_20
 
 _llgo_19:                                         ; preds = %_llgo_20
-  br label %_llgo_23
+  br label %_llgo_21
 
 _llgo_20:                                         ; preds = %_llgo_18, %_llgo_17
   %31 = phi double [ %26, %_llgo_17 ], [ %30, %_llgo_18 ]
@@ -533,68 +533,68 @@ _llgo_20:                                         ; preds = %_llgo_18, %_llgo_17
   %33 = fcmp olt double %31, 1.000000e+00
   br i1 %33, label %_llgo_18, label %_llgo_19
 
-_llgo_21:                                         ; preds = %_llgo_23
-  %34 = fdiv double %38, 1.000000e+01
-  %35 = add i64 %39, 1
-  br label %_llgo_23
+_llgo_21:                                         ; preds = %_llgo_22, %_llgo_19
+  %34 = phi double [ 5.000000e+00, %_llgo_19 ], [ %37, %_llgo_22 ]
+  %35 = phi i64 [ 0, %_llgo_19 ], [ %38, %_llgo_22 ]
+  %36 = icmp slt i64 %35, 7
+  br i1 %36, label %_llgo_22, label %_llgo_23
 
-_llgo_22:                                         ; preds = %_llgo_23
-  %36 = fadd double %31, %38
-  %37 = fcmp oge double %36, 1.000000e+01
-  br i1 %37, label %_llgo_24, label %_llgo_12
+_llgo_22:                                         ; preds = %_llgo_21
+  %37 = fdiv double %34, 1.000000e+01
+  %38 = add i64 %35, 1
+  br label %_llgo_21
 
-_llgo_23:                                         ; preds = %_llgo_21, %_llgo_19
-  %38 = phi double [ 5.000000e+00, %_llgo_19 ], [ %34, %_llgo_21 ]
-  %39 = phi i64 [ 0, %_llgo_19 ], [ %35, %_llgo_21 ]
-  %40 = icmp slt i64 %39, 7
-  br i1 %40, label %_llgo_21, label %_llgo_22
+_llgo_23:                                         ; preds = %_llgo_21
+  %39 = fadd double %31, %34
+  %40 = fcmp oge double %39, 1.000000e+01
+  br i1 %40, label %_llgo_24, label %_llgo_12
 
-_llgo_24:                                         ; preds = %_llgo_22
+_llgo_24:                                         ; preds = %_llgo_23
   %41 = add i64 %32, 1
-  %42 = fdiv double %36, 1.000000e+01
+  %42 = fdiv double %39, 1.000000e+01
   br label %_llgo_12
 
-_llgo_25:                                         ; preds = %_llgo_27
-  %43 = fptosi double %59 to i64
-  %44 = add i64 %60, 2
-  %45 = add i64 %43, 48
-  %46 = trunc i64 %45 to i8
-  %47 = getelementptr inbounds i8, ptr %11, i64 %44
-  store i8 %46, ptr %47, align 1
-  %48 = sitofp i64 %43 to double
-  %49 = fsub double %59, %48
-  %50 = fmul double %49, 1.000000e+01
-  %51 = add i64 %60, 1
-  br label %_llgo_27
+_llgo_25:                                         ; preds = %_llgo_26, %_llgo_12
+  %43 = phi double [ %18, %_llgo_12 ], [ %53, %_llgo_26 ]
+  %44 = phi i64 [ 0, %_llgo_12 ], [ %54, %_llgo_26 ]
+  %45 = icmp slt i64 %44, 7
+  br i1 %45, label %_llgo_26, label %_llgo_27
 
-_llgo_26:                                         ; preds = %_llgo_27
-  %52 = getelementptr inbounds i8, ptr %11, i64 2
-  %53 = load i8, ptr %52, align 1
-  %54 = getelementptr inbounds i8, ptr %11, i64 1
-  store i8 %53, ptr %54, align 1
+_llgo_26:                                         ; preds = %_llgo_25
+  %46 = fptosi double %43 to i64
+  %47 = add i64 %44, 2
+  %48 = add i64 %46, 48
+  %49 = trunc i64 %48 to i8
+  %50 = getelementptr inbounds i8, ptr %11, i64 %47
+  store i8 %49, ptr %50, align 1
+  %51 = sitofp i64 %46 to double
+  %52 = fsub double %43, %51
+  %53 = fmul double %52, 1.000000e+01
+  %54 = add i64 %44, 1
+  br label %_llgo_25
+
+_llgo_27:                                         ; preds = %_llgo_25
   %55 = getelementptr inbounds i8, ptr %11, i64 2
-  store i8 46, ptr %55, align 1
-  %56 = getelementptr inbounds i8, ptr %11, i64 9
-  store i8 101, ptr %56, align 1
-  %57 = getelementptr inbounds i8, ptr %11, i64 10
-  store i8 43, ptr %57, align 1
-  %58 = icmp slt i64 %19, 0
-  br i1 %58, label %_llgo_28, label %_llgo_29
+  %56 = load i8, ptr %55, align 1
+  %57 = getelementptr inbounds i8, ptr %11, i64 1
+  store i8 %56, ptr %57, align 1
+  %58 = getelementptr inbounds i8, ptr %11, i64 2
+  store i8 46, ptr %58, align 1
+  %59 = getelementptr inbounds i8, ptr %11, i64 9
+  store i8 101, ptr %59, align 1
+  %60 = getelementptr inbounds i8, ptr %11, i64 10
+  store i8 43, ptr %60, align 1
+  %61 = icmp slt i64 %19, 0
+  br i1 %61, label %_llgo_28, label %_llgo_29
 
-_llgo_27:                                         ; preds = %_llgo_25, %_llgo_12
-  %59 = phi double [ %18, %_llgo_12 ], [ %50, %_llgo_25 ]
-  %60 = phi i64 [ 0, %_llgo_12 ], [ %51, %_llgo_25 ]
-  %61 = icmp slt i64 %60, 7
-  br i1 %61, label %_llgo_25, label %_llgo_26
-
-_llgo_28:                                         ; preds = %_llgo_26
+_llgo_28:                                         ; preds = %_llgo_27
   %62 = sub i64 0, %19
   %63 = getelementptr inbounds i8, ptr %11, i64 10
   store i8 45, ptr %63, align 1
   br label %_llgo_29
 
-_llgo_29:                                         ; preds = %_llgo_28, %_llgo_26
-  %64 = phi i64 [ %19, %_llgo_26 ], [ %62, %_llgo_28 ]
+_llgo_29:                                         ; preds = %_llgo_28, %_llgo_27
+  %64 = phi i64 [ %19, %_llgo_27 ], [ %62, %_llgo_28 ]
   %65 = sdiv i64 %64, 100
   %66 = trunc i64 %65 to i8
   %67 = add i8 %66, 48
diff --git a/cl/_testdata/printf/out.ll b/cl/_testdata/printf/out.ll
index fbd81b42..02d042b6 100644
--- a/cl/_testdata/printf/out.ll
+++ b/cl/_testdata/printf/out.ll
@@ -26,14 +26,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   call void (ptr, ...) @printf(ptr @main.hello)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testdata/printval/out.ll b/cl/_testdata/printval/out.ll
index e080919a..6b97f9ef 100644
--- a/cl/_testdata/printval/out.ll
+++ b/cl/_testdata/printval/out.ll
@@ -29,14 +29,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   call void (ptr, ...) @printf(ptr @main.format, i64 100)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testdata/ptrmthd/out.ll b/cl/_testdata/ptrmthd/out.ll
index 60dcf196..79d70308 100644
--- a/cl/_testdata/ptrmthd/out.ll
+++ b/cl/_testdata/ptrmthd/out.ll
@@ -35,14 +35,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   call void @"(*main.T).Print"(ptr @main.format, i64 100)
-  ret void
+  ret i32 0
 }
 
 declare void @printf(ptr, ...)
diff --git a/cl/_testdata/uint/out.ll b/cl/_testdata/uint/out.ll
index ceaaae3a..0dde97f7 100644
--- a/cl/_testdata/uint/out.ll
+++ b/cl/_testdata/uint/out.ll
@@ -25,7 +25,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -33,7 +33,7 @@ _llgo_0:
   call void @main.init()
   %2 = call i32 @main.f(i32 100)
   %3 = call i32 (ptr, ...) @printf(ptr @0, i32 %2)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testdata/untyped/out.ll b/cl/_testdata/untyped/out.ll
index 9978c791..c64ab15b 100644
--- a/cl/_testdata/untyped/out.ll
+++ b/cl/_testdata/untyped/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -33,7 +33,7 @@ _llgo_1:                                          ; preds = %_llgo_0
   br label %_llgo_2
 
 _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testdata/vargs/out.ll b/cl/_testdata/vargs/out.ll
index 4657338e..7c75776b 100644
--- a/cl/_testdata/vargs/out.ll
+++ b/cl/_testdata/vargs/out.ll
@@ -22,7 +22,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -43,7 +43,7 @@ _llgo_0:
   store %"github.com/goplus/llgo/internal/runtime.iface" %11, ptr %9, align 8
   %12 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 16, i64 3, i64 0, i64 3, i64 3)
   call void @main.test(%"github.com/goplus/llgo/internal/runtime.Slice" %12)
-  ret void
+  ret i32 0
 }
 
 define void @main.test(%"github.com/goplus/llgo/internal/runtime.Slice" %0) {
diff --git a/cl/_testdata/varinit/out.ll b/cl/_testdata/varinit/out.ll
index 66e631ba..bd98b63c 100644
--- a/cl/_testdata/varinit/out.ll
+++ b/cl/_testdata/varinit/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -30,7 +30,7 @@ _llgo_0:
   %3 = add i64 %2, 1
   store i64 %3, ptr @main.a, align 4
   %4 = load i64, ptr @main.a, align 4
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testlibc/sqlite/out.ll b/cl/_testlibc/sqlite/out.ll
index bdf9be1a..9e43a502 100644
--- a/cl/_testlibc/sqlite/out.ll
+++ b/cl/_testlibc/sqlite/out.ll
@@ -35,7 +35,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -46,7 +46,7 @@ _llgo_0:
   %4 = extractvalue { ptr, i32 } %2, 1
   call void @main.check(i32 %4)
   %5 = call i32 @sqlite3_close(ptr %3)
-  ret void
+  ret i32 0
 }
 
 declare ptr @sqlite3_errstr(i32)
diff --git a/cl/_testpy/callpy/out.ll b/cl/_testpy/callpy/out.ll
index 1d9a8119..090e0348 100644
--- a/cl/_testpy/callpy/out.ll
+++ b/cl/_testpy/callpy/out.ll
@@ -32,7 +32,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   call void @Py_Initialize()
   store i32 %0, ptr @__llgo_argc, align 4
@@ -48,7 +48,7 @@ _llgo_0:
   %8 = call i32 (ptr, ...) @printf(ptr @0, double %7)
   %9 = call ptr @PyUnicode_AsUTF8(ptr %6)
   %10 = call i32 (ptr, ...) @printf(ptr @1, ptr %9)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/py/math.init"()
diff --git a/cl/_testpy/gcd/out.ll b/cl/_testpy/gcd/out.ll
index ccee1b2f..5d4461e5 100644
--- a/cl/_testpy/gcd/out.ll
+++ b/cl/_testpy/gcd/out.ll
@@ -25,7 +25,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   call void @Py_Initialize()
   store i32 %0, ptr @__llgo_argc, align 4
@@ -39,7 +39,7 @@ _llgo_0:
   %6 = call ptr (ptr, ...) @PyObject_CallFunctionObjArgs(ptr %5, ptr %2, ptr %3, ptr %4, ptr null)
   %7 = call i32 @PyLong_AsLong(ptr %6)
   %8 = call i32 (ptr, ...) @printf(ptr @0, i32 %7)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/py/math.init"()
diff --git a/cl/_testpy/matrix/out.ll b/cl/_testpy/matrix/out.ll
index 956009c4..4ff6b720 100644
--- a/cl/_testpy/matrix/out.ll
+++ b/cl/_testpy/matrix/out.ll
@@ -27,7 +27,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   call void @Py_Initialize()
   store i32 %0, ptr @__llgo_argc, align 4
@@ -95,7 +95,7 @@ _llgo_0:
   %60 = call ptr @PyObject_Str(ptr %53)
   %61 = call ptr @PyUnicode_AsUTF8(ptr %60)
   %62 = call i32 (ptr, ...) @printf(ptr @2, ptr %61)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/py/numpy.init"()
diff --git a/cl/_testpy/pi/out.ll b/cl/_testpy/pi/out.ll
index 78809604..face3827 100644
--- a/cl/_testpy/pi/out.ll
+++ b/cl/_testpy/pi/out.ll
@@ -31,7 +31,7 @@ _llgo_0:
   call void @main.init()
   %2 = load ptr, ptr @__llgo_py.math, align 8
   %3 = call ptr @PyObject_GetAttrString(ptr %2, ptr @1)
-  %4 = call double @PyFloat_AsDouble(ptr %3)
+  %4 = call double @"(*github.com/goplus/llgo/py.Object).Float64"(ptr %3)
   %5 = call i32 (ptr, ...) @printf(ptr @0, double %4)
   ret i32 0
 }
@@ -42,7 +42,7 @@ declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
 declare ptr @PyObject_GetAttrString(ptr, ptr)
 
-declare double @PyFloat_AsDouble(ptr)
+declare double @"(*github.com/goplus/llgo/py.Object).Float64"(ptr)
 
 declare i32 @printf(ptr, ...)
 
diff --git a/cl/_testpy/pow/out.ll b/cl/_testpy/pow/out.ll
index e1bd0f04..16c2d44a 100644
--- a/cl/_testpy/pow/out.ll
+++ b/cl/_testpy/pow/out.ll
@@ -25,7 +25,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   call void @Py_Initialize()
   store i32 %0, ptr @__llgo_argc, align 4
@@ -38,7 +38,7 @@ _llgo_0:
   %5 = call ptr (ptr, ...) @PyObject_CallFunctionObjArgs(ptr %4, ptr %2, ptr %3, ptr null)
   %6 = call double @PyFloat_AsDouble(ptr %5)
   %7 = call i32 (ptr, ...) @printf(ptr @0, double %6)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/py/math.init"()
diff --git a/cl/_testrt/alloca/out.ll b/cl/_testrt/alloca/out.ll
index 0593e6b7..452d403a 100644
--- a/cl/_testrt/alloca/out.ll
+++ b/cl/_testrt/alloca/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -29,7 +29,7 @@ _llgo_0:
   %2 = alloca i8, i64 4, align 1
   %3 = call ptr @memcpy(ptr %2, ptr @0, i64 4)
   %4 = call i32 (ptr, ...) @printf(ptr @1, ptr %2)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/allocstr/out.ll b/cl/_testrt/allocstr/out.ll
index 5726edc7..e3373759 100644
--- a/cl/_testrt/allocstr/out.ll
+++ b/cl/_testrt/allocstr/out.ll
@@ -27,7 +27,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -39,7 +39,7 @@ _llgo_0:
   %5 = alloca i8, i64 %4, align 1
   %6 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %5, %"github.com/goplus/llgo/internal/runtime.String" %2)
   %7 = call i32 (ptr, ...) @printf(ptr %6)
-  ret void
+  ret i32 0
 }
 
 declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr, i64)
diff --git a/cl/_testrt/any/out.ll b/cl/_testrt/any/out.ll
index ee4c5f30..fdd52ad1 100644
--- a/cl/_testrt/any/out.ll
+++ b/cl/_testrt/any/out.ll
@@ -29,7 +29,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -39,7 +39,7 @@ _llgo_0:
   %3 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyInt"(ptr %2, i64 100)
   %4 = call i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.iface" %3)
   %5 = call i32 (ptr, ...) @printf(ptr @0, i64 %4)
-  ret void
+  ret i32 0
 }
 
 declare i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
diff --git a/cl/_testrt/builtin/out.ll b/cl/_testrt/builtin/out.ll
index 5cd53638..a844642e 100644
--- a/cl/_testrt/builtin/out.ll
+++ b/cl/_testrt/builtin/out.ll
@@ -72,7 +72,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -310,7 +310,7 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.PrintUint"(i64 %126)
   %135 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @43, i64 1)
   call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %135)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/callback/out.ll b/cl/_testrt/callback/out.ll
index 663812c1..42ae697a 100644
--- a/cl/_testrt/callback/out.ll
+++ b/cl/_testrt/callback/out.ll
@@ -28,7 +28,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -48,7 +48,7 @@ _llgo_0:
   store ptr null, ptr %8, align 8
   %9 = load { ptr, ptr }, ptr %6, align 8
   call void @main.callback(ptr @1, { ptr, ptr } %9)
-  ret void
+  ret i32 0
 }
 
 define void @main.print(ptr %0) {
diff --git a/cl/_testrt/cast/out.ll b/cl/_testrt/cast/out.ll
index 65c7100b..313b7037 100644
--- a/cl/_testrt/cast/out.ll
+++ b/cl/_testrt/cast/out.ll
@@ -237,7 +237,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -298,7 +298,7 @@ _llgo_0:
   call void @main.cvt32to64(i32 0, i64 0)
   call void @main.cvt32to64(i32 2147483647, i64 2147483647)
   call void @main.cvtUinptr(i32 1024, i64 1024)
-  ret void
+  ret i32 0
 }
 
 declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr, i64)
diff --git a/cl/_testrt/closure/out.ll b/cl/_testrt/closure/out.ll
index d6f12d17..e3a0e66f 100644
--- a/cl/_testrt/closure/out.ll
+++ b/cl/_testrt/closure/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -47,7 +47,7 @@ _llgo_0:
   %13 = extractvalue { ptr, ptr } %12, 1
   %14 = extractvalue { ptr, ptr } %12, 0
   call void %14(ptr %13)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/concat/out.ll b/cl/_testrt/concat/out.ll
index af3e1e82..00c7d18a 100644
--- a/cl/_testrt/concat/out.ll
+++ b/cl/_testrt/concat/out.ll
@@ -73,7 +73,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -97,7 +97,7 @@ _llgo_0:
   %14 = alloca i8, i64 %13, align 1
   %15 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %14, %"github.com/goplus/llgo/internal/runtime.String" %10)
   %16 = call i32 (ptr, ptr, ...) @fprintf(ptr %11, ptr @6, ptr %15)
-  ret void
+  ret i32 0
 }
 
 declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.StringCat"(%"github.com/goplus/llgo/internal/runtime.String", %"github.com/goplus/llgo/internal/runtime.String")
diff --git a/cl/_testrt/cstr/out.ll b/cl/_testrt/cstr/out.ll
index 176c625d..480ae6d2 100644
--- a/cl/_testrt/cstr/out.ll
+++ b/cl/_testrt/cstr/out.ll
@@ -19,14 +19,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   call void (ptr, ...) @printf(ptr @0)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/cvar/out.ll b/cl/_testrt/cvar/out.ll
index 480991fc..bd6f7762 100644
--- a/cl/_testrt/cvar/out.ll
+++ b/cl/_testrt/cvar/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -28,7 +28,7 @@ _llgo_0:
   call void @main.init()
   %2 = load { [16 x i8], [2 x ptr] }, ptr @_bar_x, align 8
   %3 = load { [16 x i8] }, ptr @_bar_y, align 1
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/fprintf/out.ll b/cl/_testrt/fprintf/out.ll
index ef638102..0046e6ca 100644
--- a/cl/_testrt/fprintf/out.ll
+++ b/cl/_testrt/fprintf/out.ll
@@ -20,7 +20,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -28,7 +28,7 @@ _llgo_0:
   call void @main.init()
   %2 = load ptr, ptr @__stderrp, align 8
   call void (ptr, ptr, ...) @fprintf(ptr %2, ptr @0, i64 100)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/gblarray/out.ll b/cl/_testrt/gblarray/out.ll
index 0acd8155..d0f42446 100644
--- a/cl/_testrt/gblarray/out.ll
+++ b/cl/_testrt/gblarray/out.ll
@@ -50,7 +50,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -63,7 +63,7 @@ _llgo_0:
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/abi.Type", ptr %2, i32 0, i32 0
   %7 = load i64, ptr %6, align 4
   %8 = call i32 (ptr, ...) @printf(ptr @0, i64 %5, i64 %7)
-  ret void
+  ret i32 0
 }
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
diff --git a/cl/_testrt/gotypes/out.ll b/cl/_testrt/gotypes/out.ll
index 3702addc..ae8de993 100644
--- a/cl/_testrt/gotypes/out.ll
+++ b/cl/_testrt/gotypes/out.ll
@@ -25,14 +25,14 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   call void @main.foo(%"github.com/goplus/llgo/internal/runtime.iface" zeroinitializer)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/hello/out.ll b/cl/_testrt/hello/out.ll
index f186523a..f71fe323 100644
--- a/cl/_testrt/hello/out.ll
+++ b/cl/_testrt/hello/out.ll
@@ -29,7 +29,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -37,7 +37,7 @@ _llgo_0:
   call void @main.init()
   %2 = call i32 @strlen(ptr @main.format)
   call void (ptr, ...) @printf(ptr @main.format, i32 %2)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/index/out.ll b/cl/_testrt/index/out.ll
index a9af0027..834b497e 100644
--- a/cl/_testrt/index/out.ll
+++ b/cl/_testrt/index/out.ll
@@ -29,7 +29,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -128,7 +128,7 @@ _llgo_0:
   %70 = getelementptr inbounds i8, ptr %69, i64 1
   %71 = load i8, ptr %70, align 1
   %72 = call i32 (ptr, ...) @printf(ptr @6, i8 %71)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/intgen/out.ll b/cl/_testrt/intgen/out.ll
index 8d91dd12..a344eb5f 100644
--- a/cl/_testrt/intgen/out.ll
+++ b/cl/_testrt/intgen/out.ll
@@ -63,7 +63,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -152,7 +152,7 @@ _llgo_8:                                          ; preds = %_llgo_7
   br label %_llgo_7
 
 _llgo_9:                                          ; preds = %_llgo_7
-  ret void
+  ret i32 0
 }
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
diff --git a/cl/_testrt/linkname/out.ll b/cl/_testrt/linkname/out.ll
index 41d631cf..47f22283 100644
--- a/cl/_testrt/linkname/out.ll
+++ b/cl/_testrt/linkname/out.ll
@@ -26,7 +26,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -34,7 +34,7 @@ _llgo_0:
   call void @main.init()
   call void @"github.com/goplus/llgo/cl/internal/linktarget.F"(ptr @0, ptr @1, ptr @2, ptr @3)
   call void @"github.com/goplus/llgo/cl/internal/linktarget.F"(ptr @4, ptr @5, ptr @6, ptr @7)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/cl/internal/linktarget.F"(ptr, ptr, ptr, ptr)
diff --git a/cl/_testrt/map/out.ll b/cl/_testrt/map/out.ll
index c353f5d7..1a93ecaf 100644
--- a/cl/_testrt/map/out.ll
+++ b/cl/_testrt/map/out.ll
@@ -19,7 +19,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -27,7 +27,7 @@ _llgo_0:
   call void @main.init()
   %2 = call ptr @"github.com/goplus/llgo/internal/runtime.MakeSmallMap"()
   %3 = call i32 (ptr, ...) @printf(ptr @0, <null operand!>)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/mask/out.ll b/cl/_testrt/mask/out.ll
index bea4f657..f74ebc84 100644
--- a/cl/_testrt/mask/out.ll
+++ b/cl/_testrt/mask/out.ll
@@ -21,7 +21,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -32,7 +32,7 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.PrintInt"(i64 %3)
   %4 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @0, i64 1)
   call void @"github.com/goplus/llgo/internal/runtime.PrintString"(%"github.com/goplus/llgo/internal/runtime.String" %4)
-  ret void
+  ret i32 0
 }
 
 define i32 @main.mask(i8 %0) {
diff --git a/cl/_testrt/named/out.ll b/cl/_testrt/named/out.ll
index e7d0af04..cb5f0e64 100644
--- a/cl/_testrt/named/out.ll
+++ b/cl/_testrt/named/out.ll
@@ -23,7 +23,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -120,7 +120,7 @@ _llgo_0:
   %77 = extractvalue { ptr, ptr } %75, 0
   %78 = call i64 %77(ptr %76, i64 -3)
   %79 = call i32 (ptr, ...) @printf(ptr @0, i64 %46, i64 %53, i64 %57, i64 %63, i64 %69, i64 %78)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/panic/out.ll b/cl/_testrt/panic/out.ll
index eb2cf3ea..331bbfbf 100644
--- a/cl/_testrt/panic/out.ll
+++ b/cl/_testrt/panic/out.ll
@@ -22,7 +22,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
diff --git a/cl/_testrt/qsort/out.ll b/cl/_testrt/qsort/out.ll
index 9767c44d..2d203ee1 100644
--- a/cl/_testrt/qsort/out.ll
+++ b/cl/_testrt/qsort/out.ll
@@ -19,7 +19,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -54,7 +54,7 @@ _llgo_2:                                          ; preds = %_llgo_1
   br label %_llgo_1
 
 _llgo_3:                                          ; preds = %_llgo_1
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/result/out.ll b/cl/_testrt/result/out.ll
index bc0ebd58..4664affe 100644
--- a/cl/_testrt/result/out.ll
+++ b/cl/_testrt/result/out.ll
@@ -45,7 +45,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -69,7 +69,7 @@ _llgo_0:
   %17 = extractvalue { ptr, ptr } %15, 0
   %18 = call i64 %17(ptr %16, i64 100, i64 200)
   %19 = call i32 (ptr, ...) @printf(ptr @2, i64 %18, i64 %14)
-  ret void
+  ret i32 0
 }
 
 define i64 @"main.add$1"(i64 %0, i64 %1) {
diff --git a/cl/_testrt/strlen/out.ll b/cl/_testrt/strlen/out.ll
index f186523a..f71fe323 100644
--- a/cl/_testrt/strlen/out.ll
+++ b/cl/_testrt/strlen/out.ll
@@ -29,7 +29,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -37,7 +37,7 @@ _llgo_0:
   call void @main.init()
   %2 = call i32 @strlen(ptr @main.format)
   call void (ptr, ...) @printf(ptr @main.format, i32 %2)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/struct/out.ll b/cl/_testrt/struct/out.ll
index 04c5725b..04ab01fc 100644
--- a/cl/_testrt/struct/out.ll
+++ b/cl/_testrt/struct/out.ll
@@ -57,7 +57,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -71,7 +71,7 @@ _llgo_0:
   store i1 true, ptr %5, align 1
   %6 = load %main.Foo, ptr %3, align 4
   call void @"(main.Foo).Print"(%main.Foo %6)
-  ret void
+  ret i32 0
 }
 
 declare ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr, i64)
diff --git a/cl/_testrt/sum/out.ll b/cl/_testrt/sum/out.ll
index e414fa91..70c4be76 100644
--- a/cl/_testrt/sum/out.ll
+++ b/cl/_testrt/sum/out.ll
@@ -21,7 +21,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -39,7 +39,7 @@ _llgo_0:
   %7 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %2, i64 8, i64 4, i64 0, i64 4, i64 4)
   %8 = call i64 @main.sum(%"github.com/goplus/llgo/internal/runtime.Slice" %7)
   %9 = call i32 (ptr, ...) @printf(ptr @0, i64 %8)
-  ret void
+  ret i32 0
 }
 
 define i64 @main.sum(%"github.com/goplus/llgo/internal/runtime.Slice" %0) {
diff --git a/cl/_testrt/typalias/out.ll b/cl/_testrt/typalias/out.ll
index c76ce402..b77f76a7 100644
--- a/cl/_testrt/typalias/out.ll
+++ b/cl/_testrt/typalias/out.ll
@@ -45,7 +45,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -57,7 +57,7 @@ _llgo_0:
   store i32 100, ptr %3, align 4
   store i1 true, ptr %4, align 1
   call void @main.Print(ptr %2)
-  ret void
+  ret i32 0
 }
 
 declare void @printf(ptr, ...)
diff --git a/cl/_testrt/unreachable/out.ll b/cl/_testrt/unreachable/out.ll
index 6b84c00b..0e3a0f72 100644
--- a/cl/_testrt/unreachable/out.ll
+++ b/cl/_testrt/unreachable/out.ll
@@ -25,7 +25,7 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
-define void @main(i32 %0, ptr %1) {
+define i32 @main(i32 %0, ptr %1) {
 _llgo_0:
   store i32 %0, ptr @__llgo_argc, align 4
   store ptr %1, ptr @__llgo_argv, align 8
@@ -33,7 +33,7 @@ _llgo_0:
   call void @main.init()
   call void @main.foo()
   %2 = call i32 (ptr, ...) @printf(ptr @0)
-  ret void
+  ret i32 0
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()