use strict;
use Benchmark "cmpthese";
my $foo = new foo;
cmpthese(-5,{
	     direct=>sub{
	       $foo->{bar}
	     },
	     accessor=>sub{
	       $foo->bar;
	     }
	    }
);

package foo;
sub new {
  my $class = shift;
  my $self = {
	      bar=>"I am a bar"
	     };
  bless $self,$class;
}

sub bar{
  my $self = shift;
  if (@_) {
    return $self->{bar} = shift;
  }
  return $self->{bar};
}
__OUTPUT__

Benchmark: running accessor, direct, each for at least 5 CPU seconds...
  accessor:  6 wallclock secs ( 5.08 usr +  0.01 sys =  5.09 CPU) @ 994059.72/s (n=5059764)
    direct:  4 wallclock secs ( 5.07 usr + -0.01 sys =  5.06 CPU) @ 6795643.87/s (n=34385958)
              Rate accessor   direct
accessor  994060/s       --     -85%
direct   6795644/s     584%       --