use Benchmark;
my $n = 1000;
open(STDERR,">/dev/null");
cmpthese (1000,
            {
              match => sub { local $_ = "abcde    " x $n;
                             print STDERR "$1\n" while /\G(.{1,80})/gs;
                           },
              swap  => sub { local $_ = "abcde    " x $n;
                             s/\G(.{1,80})/$1\n/gs;
                             print STDERR $_;
                           },
              subst => sub { local $a = "abcde    " x $n;
                             $b='';
                             $b .= substr( $a, 0, 80, '')."\n" while length($a) >80;
                             print STDERR "$b$a";
                           },
            });