Oplossing reg-exp recursief

; oefening 4
(assemble-and-run '(start
                    (assign v1 (const 3))
                    (assign v2 (const 5))
                    (assign cont (label stop))
                    (goto (label start-expt-rec))

                    start-expt-rec
                    (test (op =) (reg v2) (const 0))
                    (branch (label return-1))
                    (save cont)
                    (assign cont (label rec-exp))
                    (assign v2 (op -) (reg v2) (const 1))
                    (goto (label start-expt-rec))

                    rec-exp
                    (assign res (op *) (reg v1) (reg res))
                    (restore cont)
                    (goto (reg cont))


                    return-1
                    (assign res (const 1))
                    (goto (reg cont))

                    stop))