con
  _clkmode = $62
  _clkfreq = $4E495053 ' SPIN

obj
  c : "clibsd"

dat
  primes    long  $00020001, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
            long  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  last      long  0

pub main(argc, argv) | i, j, n, num, maxnum, count, prime

  c.enter(argc, argv)

  if argc <> 2
    c.printf0(string("usage: prime max_number\n"))
    c.exit(1)

  maxnum := 0
  i := long[argv][1]
  repeat while byte[i]
    maxnum := (maxnum * 10) + byte[i++] - "0"

  c.printf1(string("%d "), 1)
  c.printf1(string("%d "), 2)

  num := (@last - @primes)/2
  n := 2
  i := 3
  count := 2
  repeat while i < maxnum
    j := 2
    repeat while j < n
      prime := word[@primes][j]
      if prime * prime > i
        j := n
        quit
      if i / prime * prime == i
        quit
      j++
    if j == n
      if n < num
        word[@primes][n++] := i
        if n == num and i * i < maxnum
          maxnum := i * i
      c.printf1(string("%d "), i)
      if ++count => 10
        count := 0
        c.printf0(string("\n"))
    i += 2
  if count
    c.printf0(string("\n"))
  c.exit(0)