;; simple call 

;; sq(x) { return x * x }
;; main(){ a = 2; b = sq(a); }

;; let r1 = a, r2 = b, 
;; r3 = input x, r4 = retv, r5 = link

.s 
	a 100
	b 101
.a 0
.c
:main 	ld r1 #2
	st a r1
	or r3 r1 r0 ;; x = a
	jal r5 sq
	or r2 r4 r0 ;; b = retv
	st b r2
	trap stop r0

:sq	mul r4 r3 r3 ;; retv = x * x
	jr r5	     ;; return
.e