Benchmarking rakudo + mandelbrot-color on top of master (original) and green_threads

stats.pl

my @patched  = (36.272, 36.177, 36.078, 36.229, 35.981);
my @original = (34.223, 34.061, 33.960, 33.945, 33.636);

sub avg(*@a) {
    ([+] @a) / @a.elems;
}

sub std(*@a) {
    sqrt( (avg(@a X** 2) - avg(@a) ** 2 ) / (@a.elems - 1));
}

my $avg_p = avg @patched;
my $std_p = std @patched;
my $avg_o = avg @original;
my $std_o = std @original;

my $std = ($std_p + $std_o) / sqrt(2);
my $sigmas = abs($avg_p - $avg_o) / $std;

say "Original: $avg_o ± $std_o";
say "Patched:  $avg_p ± $std_p";
printf "Patched version is %s than the original by %.2f%%, signficance %.1fσ\n",
    ($avg_o < $avg_p) ?? 'slower' !! 'faster',
    abs($avg_o - $avg_p) / $avg_o * 100,
    $sigmas;