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

my $count = -100;
cmpthese($count, {
    'Split' => sub {
        my $document;
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        while (<FILE>) { $document .= $_ }
        my @lines = split('\|',$document);
	return @lines;
    },
    'IRS_while' => sub {
        local $/ = '|';
        my @lines;
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        while (<FILE>) {
            chomp;
            push @lines, $_;            
        }
	return @lines;
    },
    'IRS_map' => sub {
        local $/ = '|';
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        my @lines = map {chomp; $_} (<FILE>);
	return @lines;
    },
});

##</code><code>##

             Rate   IRS_map     Split IRS_while
IRS_map    9804/s        --      -24%      -27%
Split     12876/s       31%        --       -4%
IRS_while 13399/s       37%        4%        --

##</code><code>##

This is perl 5, version 12, subversion 3 (v5.12.3) built for MSWin32-x86-multi-thread