[backend] incorrect asm output

test/01_add.sy

@@ -1,12 +1,8 @@
 //test add
 
-
 int main(){
     int a, b;
-    float d;
     a = 10;
     b = 2;
-    int c = a;
-    d = 1.1 ;
-    return a + b + c;
+    return a + b;
 }