davido:~/scripts$ perlbrew exec --with perl-5.10.1 perl mytest.pl
Perl version: 5.010001

          Rate retn bare
retn 6849315/s   --  -8%
bare 7462687/s   9%   --

(25000000, 25000000)


davido:~/scripts$ perlbrew exec --with perl-5.28.0 perl mytest.pl
Perl version: 5.028000

           Rate bare retn
bare 10729614/s   --  -3%
retn 11013216/s   3%   --

(25000000, 25000000)

##</code><code>##

use strict;                      
use warnings;                    
                                 
use Benchmark qw(cmpthese);      
                                 
my $x;                           
my $y;                           
                                 
sub bare { ++$x; $x }            
sub retn { ++$y; return $y }     
                                 
print "Perl version: $]\n\n";    
                                 
cmpthese(25_000_000, {           
    bare => sub {my $t = bare()},
    retn => sub {my $t = retn()},
});                              
                                 
print "\n($x, $y)\n";