; 1073741823 * 2 < 2^31, and will not overflow.
        big = immi 1073741823
        two = immi 2
        
        res = muljovi big two err
        
        ; Ensure that 'big' and 'two' get their own registers and
        ; aren't shared with 'res'.
        m = allocp 12
        sti big m 0
        sti two m 4
        
        reti res

; ---- Exit route for the error handler.

err:    e = immi -1
        reti e