   0 ;; simple call 
   0 
   0 ;; sq(x) { return x * x }
   0 ;; main(){ a = 2; b = sq(a); }
   0 
   0 ;; let r1 = a, r2 = b, 
   0 ;; r3 = input x, r4 = retv, r5 = link
   0 
   0 .s 
   0 	a 100
   0 	b 101
   0 .a 0
   0 .c
   0 :main 	ld r1 #2
   1 	st a r1
   2 	or r3 r1 r0 ;; x = a
   3 	jal r5 sq
   4 	or r2 r4 r0 ;; b = retv
   5 	st b r2
   6 	trap stop r0
   7 
   7 :sq	mul r4 r3 r3 ;; retv = x * x
   8 	jr r5	     ;; return
   9 .e
