なんでだろ〜なんでだろ〜

gistfile1.pl

#!/usr/bin/env perl
use strict;
use warnings;
use utf8;
use Benchmark qw(cmpthese);

my $pattern = '((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))';
my $regexp = qr/$pattern/;
my $ipv4 = '192.168.1.1';
cmpthese(0, +{
    'precompile' => sub {
        $ipv4 =~ $regexp;
    },
    'runtime' => sub {
        $ipv4 =~ /$pattern/;
    },
    'runtime_optimized' => sub {
        $ipv4 =~ /$pattern/o;
    },
    'runtime_static' => sub {
        $ipv4 =~ /((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))/;
    },
});

#                        Rate precompile  runtime runtime_optimized runtime_static
# precompile         939495/s         --     -28%              -32%           -35%
# runtime           1313724/s        40%       --               -4%            -8%
# runtime_optimized 1372723/s        46%       4%                --            -4%
# runtime_static    1435474/s        53%       9%                5%             --