use Benchmark qw(cmpthese);
use strict;
use warnings;

my $original;
$original.= chr(int(rand(128))) for 1..1000;

my $add = $original;

for (1..20) {

    print "\n","Length of string: ",length($original),"\n";

    cmpthese (1000000,{
        ref =>      sub { my $new = $original; by_ref(\$new)  },
        alias =>    sub { my $new = $original; by_alias($new) },

    });
    $original.=$add;
}

sub by_alias {
   $_[0]  =~ s/\s+//;
}

sub by_ref {
   ${ $_[0] } =~ s/\s+//;
}