#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw(cmpthese);

my %case=(
  a => sub{ return 1*shift; },
  b => sub{ return 2*shift; },
  c => sub{ return 3*shift; },
  d => sub{ return 4*shift; },
);

*my_a=$case{a};
*my_b=$case{b};
*my_c=$case{c};
*my_d=$case{d};

sub rstr{ return chr(int(rand(4))+97) }

sub gto
{
  goto $case{rstr()};
}

sub rcl
{
  $case{rstr()}->(@_);
}

sub als
{
  my $f=rstr();
  $f eq 'a' and return my_a(@_);
  $f eq 'b' and return my_b(@_);
  $f eq 'c' and return my_c(@_);
  $f eq 'd' and return my_d(@_);
}

cmpthese(1000000, {
  'goto'    => sub{ gto(55); },
  'refcall' => sub{ rcl(55); },
  'alias'   => sub{ als(55); },
});