use Benchmark qw(:all);

my $a = 10;
my $b = 20;

cmpthese(-2, {
        'Direct' => sub {
            my $c = $a+$b;
        },
        'Sub' => sub {
            my $c = add ($a, $b);
        },
        'Method' => sub {
            my $c = __PACKAGE__->meth_add ($a, $b);
        },
        'Method+sub' => sub {
            my $c = __PACKAGE__->meth_sub_add ($a, $b);
        },
        'Sub^2' => sub {
            my $c = add2 ($a, $b);
        },
        'Method^2' => sub {
            my $c = __PACKAGE__->meth2 ($a, $b);
        },
    });

sub add {
    return $_[0] + $_[1];
}

sub add2 {
    return add (@_);
}

sub meth_add {
    shift;
    return $_[0] + $_[1];
}

sub meth_sub_add {
    shift;
    return add (@_);
}

sub meth2 {
    return $_[0] -> meth_add ( $_[1], $_[2] );
}