use Benchmark 'cmpthese';

cmpthese -1, {
              'shift'=> sub { 
                            my $x=shift;
                            my $y=shift;
                            my $z=shift; 

                            return
                        },
              'assign'=> sub { 
                            my ($x,$y,$z)=@_; 
                         },
		    };
__END__
Benchmark: running assign, shift, each for at least 1 CPU seconds...
    assign:  2 wallclock secs ( 1.23 usr) @ 505470.78/s (n=622740)
     shift:  3 wallclock secs ( 1.01 usr) @ 435373.52/s (n=440598)
           Rate  shift assign
shift  435374/s     --   -14%
assign 505471/s    16%     --
		    

##</code><code>##

for (1..100) { ++$x; $x+=$y+=$z } 

##</code><code>##


Benchmark: running assign, shift, each for at least 1 CPU seconds...
    assign:  2 wallclock secs ( 1.08 usr ) @ 7097.97/s (n=7680)
     shift:  1 wallclock secs ( 1.02 usr ) @ 6973.56/s (n=7120)
         Rate  shift assign
shift  6974/s     --    -2%
assign 7098/s     2%     --
Benchmark: running assign, shift, each for at least 1 CPU seconds...
    assign:  2 wallclock secs ( 1.01 usr ) @ 7587.94/s (n=7679)
     shift:  2 wallclock secs ( 1.08 usr ) @ 7592.04/s (n=8207)
         Rate assign  shift
assign 7588/s     --    -0%
shift  7592/s     0%     --