our @data = map { 'x' x 1000 } 1..1000;
cmpthese -2, { map { $_ => "$_ \@data" } qw/naive listutil buk ikegami blokhead/ };

           Rate    naive  ikegami listutil      buk blokhead
naive    76.1/s       --     -26%     -47%     -88%     -88%
ikegami   103/s      36%       --     -28%     -84%     -84%
listutil  143/s      89%      39%       --     -78%     -78%
buk       638/s     739%     518%     345%       --      -1%
blokhead  643/s     745%     522%     348%       1%       --