gistfile1.txt

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

my $h = '25';
my $pattern = '((?:(?:'.$h.'[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 $regexp_o = qr/$pattern/o;
my $ipv4 = '192.168.1.1';

cmpthese(0, +{
    'precompile' => sub {
        $ipv4 =~ $regexp;
    },
    'precompile_o' => sub {
        $ipv4 =~ $regexp_o;
    },
    'runtime' => sub {
        $ipv4 =~ /$pattern/;
    },
    'runtime_optimized' => sub {
        $ipv4 =~ /$pattern/o;
    },
    'runtime_static' => sub {
        $ipv4 =~ /((?:(?:$h[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]?))/;
    },
    'runtime_static_o' => sub {
        $ipv4 =~ /((?:(?:$h[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]?))/o;
    },
});

結論 https://gist.github.com/i110/28abb5692ee1ed2bbb0a