#!/usr/bin/perl 
use strict;
use warnings;
use Regexp::Common qw /net/;
use Benchmark qw( cmpthese );

my $line = q{127.0.0.1}; 

cmpthese -10, {
    RE => '$line =~ /\A $RE{net}{IPv4} [|] password [|] (ssn=) \z/xmi',

    RE_O => '$line =~ /\A $RE{net}{IPv4} [|] password [|] (ssn=) \z/xmio',

    ORIG => '$line =~ /[\d]{1,3}\.[\d]{1,3}\.[\d]{1,3}\.[\d]{1,3}\|password\|(ssn=)/i',

    RE_CHAR => 'use charnames qw( :full);
                $line =~ /\A $RE{net}{IPv4}
                             \N{LINE TABULATION}
                             password
                             \N{LINE TABULATION}
                             (ssn=) \z/xmi'

};