my $t1 = timeit(1_000_000, \&odd_1);
my $t2 = timeit(1_000_000, \&odd_2);
print "odd_1: ",timestr($t1),"\n";
print "odd_2: ",timestr($t2),"\n";

sub odd_1 {
  my $num = rand(2**31);
  return $num % 2;
}

sub odd_2 {
  my $num = rand(2**31);
  return $num & 1;
}