Dart lang prime numbers benchmark

import 'dart:core';
import 'dart:math';
import 'dart:io';

get_primes7(num n) {
    if (n < 2) { return []; }
    if (n == 2) { return [2]; }

    var s = [];
    for (var i = 3; i < n + 1; i += 2) {
        s.add(i);
    }

    var mroot = sqrt(n).round();
    var half = s.length;
    var i = 0;
    var m = 3;

    while (m <= mroot) {
        if (s[i] != 0) {
            var j = ((m*m-3)/2).round();
            s[j] = 0;
            while (j < half) {
                s[j] = 0;
                j += m;
            }
        }
        i = i + 1;
        m = 2*i + 3;
    }

    var res = [2];
    for (var x = 0; x < s.length; x++) {
        if (s[x] != 0) {
            res.add(s[x]);
        }
    }
    return res;
}

main() {
    for (var i = 0; i < 10; i++) {
        var res = get_primes7(10000000);
        stdout.writeln("Found " + res.length.toString() + " prime numbers.");
    }
}