trying to implement exponentiation by squaring efficiently on perl 6

exp-by-squaring.p6

# https://en.wikipedia.org/wiki/Exponentiation_by_squaring
sub exp-by-squaring-iterative(Numeric $x is copy, int $n is copy) {
    return 1 if $n == 0;
    if $n < 0 {
        $x = 1 / $x;
        $n = -$n;
    }
    my $y = 1;
    while $n > 1 {
        $y = $y * $x if $n +& 1;
        $x = $x * $x;
        $n = $n +> 1;
    }
    return $x * $y
}

my ($x, $n) = (2..10).pick, 1001;
my $now = now;
say (exp-by-squaring-iterative($x, $n) xx 10_000).pick;
say now - $now;

$now = now;
say ($x ** $n xx 10_000).pick;
say now - $now;