Rate copied  proto caller direct called  NAMED
copied 105/s     --   -52%   -62%   -62%   -62%   -62%

 proto 219/s   109%     --   -20%   -21%   -21%   -21%

caller 274/s   162%    25%     --    -1%    -1%    -2%
direct 277/s   164%    26%     1%     --    -0%    -1%
called 277/s   164%    26%     1%     0%     --    -1%
 NAMED 279/s   166%    27%     2%     1%     1%     --

##</code><code>##

          Rate copied called caller  proto  NAMED direct
copied 15741/s     --   -54%   -57%   -66%   -74%   -74%

called 34560/s   120%     --    -5%   -25%   -43%   -44%
caller 36557/s   132%     6%     --   -21%   -39%   -41%

 proto 46058/s   193%    33%    26%     --   -24%   -25%

 NAMED 60268/s   283%    74%    65%    31%     --    -2%
direct 61563/s   291%    78%    68%    34%     2%     --

##</code><code>##

use constant {
    STRING=>0,
    NUMS=>1,
};

sub foo{
    $_[STRING] =~ tr[...][...] if $_[NUMS] == '123';
}

##</code><code>##

#! perl -slw
use strict;
use vars qw[ $VALIDATE ];
use Benchmark qw[ cmpthese ];


sub copied_args {
    my( $a1, $a2 ) = @_;
    $a1 =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $a2 =~ tr[0-9][9876543210];
    return $a1, $a2;
}

sub proto_refs ($$) {
    my( $a1, $a2 ) = @_;
    $a1 =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $a2 =~ tr[0-9][9876543210];
    return;
}

sub caller_refs {
    my( $a1, $a2 ) = @_;
    $$a1 =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $$a2 =~ tr[0-9][9876543210];
    return;
}

sub called_refs {
    my( $a1, $a2 ) = \( @_ );
    $$a1 =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $$a2 =~ tr[0-9][9876543210];
    return;
}

sub direct_args {
    $_[0] =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $_[1] =~ tr[0-9][9876543210];
    return;
}

use constant { STRING=>0, NUMS=>1 };
sub NAMED_args {
    $_[STRING] =~ tr[A-Za-z][N-ZA-Mn-za-m];
    $_[NUMS] =~ tr[0-9][9876543210];
    return;
}


our $small_text = 'The Quick Brown Fox Jumps Over The Lazy Dog';
our $large_text = $small_text x 1000;
our $small_nums = '0123456789';
our $large_nums = $small_nums x 1000;

if( $VALIDATE ) {
    ( $small_text, $small_nums ) =
    copied_args $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    ( $small_text, $small_nums ) =
    copied_args $small_text,  $small_nums; print $small_text, ' : ', $small_nums;

    caller_refs \$small_text, \$small_nums; print $small_text, ' : ', $small_nums;
    caller_refs \$small_text, \$small_nums; print $small_text, ' : ', $small_nums;
    called_refs  $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    called_refs  $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    proto_refs   $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    proto_refs   $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    direct_args  $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    direct_args  $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    NAMED_args   $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
    NAMED_args   $small_text,  $small_nums; print $small_text, ' : ', $small_nums;
}
else {
    cmpthese( -3, {
        'copied_small'  => q[ ( $small_text, $small_nums ) =
                              copied_args  $small_text,  $small_nums; ],
        'caller_small'  => q[ caller_refs \$small_text, \$small_nums; ],
        'called_small'  => q[ called_refs  $small_text,  $small_nums; ],
        ' proto_small'  => q[ proto_refs   $small_text,  $small_nums; ],
        'direct_small'  => q[ direct_args  $small_text,  $small_nums; ],
        ' NAMED_small'  => q[ NAMED_args   $small_text,  $small_nums; ],
    });

    cmpthese( -3, {
        'copied_large'  => q[ ( $large_text, $large_nums ) =
                              copied_args  $large_text,  $large_nums; ],
        'caller_large'  => q[ caller_refs \$large_text, \$large_nums; ],
        'called_large'  => q[ called_refs  $large_text,  $large_nums; ],
        ' proto_large'  => q[ proto_refs   $large_text,  $large_nums; ],
        'direct_large'  => q[ direct_args  $large_text,  $large_nums; ],
        ' NAMED_large'  => q[ NAMED_args   $large_text,  $large_nums; ],
    });
}