#  Multiply rational numbers
#
#  Input:    tos-2    multiplicand
#
#      tos-1    multiplier
#
#  Output:    product on stack



qmul = ->
  save()

  p2 = pop()
  p1 = pop()

  # zero?

  if (MZERO(p1.q.a) || MZERO(p2.q.a))
    push(zero)
    restore()
    return

  aa = mmul(p1.q.a, p2.q.a)
  bb = mmul(p1.q.b, p2.q.b)

  c = mgcd(aa, bb)

  c = makeSignSameAs(c,bb)

  p1 = new U()

  p1.k = NUM

  p1.q.a = mdiv(aa, c)
  p1.q.b = mdiv(bb, c)

  #mfree(aa)
  #mfree(bb)

  push(p1)

  restore()