Select Code to Download

use strict;
use Benchmark qw(cmpthese);
...
   b => '$m = $_ for (1..$n)',
   c => 'for ($i=1;$i<$n+1;$i++) {$m = $i}'
});

use strict;
use Benchmark;
...
my $t1 = new Benchmark;
my $td = timediff($t1, $t0);
print "x: ",timestr($td),"\n";