use strict;
use warnings;
use Benchmark qw( cmpthese );
use constant DEBUG => 0;

our $N ||= -3;
our $debug = 0;
our $b = 100;

cmpthese $N, {
    constant   => q{
        for( 1 .. 1000 ){ my $a = 10 * $b; $a = 10 * $b if DEBUG; }
    },
    noconstant => q{ for( 1 .. 1000 ){ my $a = 10 * $b; } },
    var => q{
        our $debug;
        for( 1.. 1000 ){  my $a = 10 * $b; $a = 10 * $b if $debug; }
    },
};

__END__
C:\test>junk6 -N=-1
             Rate        var   constant noconstant
var        2222/s         --       -19%       -19%
constant   2731/s        23%         --        -1%
noconstant 2745/s        24%         1%         --

C:\test>junk6 -N=-3
             Rate        var   constant noconstant
var        2133/s         --       -20%       -25%
constant   2662/s        25%         --        -6%
noconstant 2831/s        33%         6%         --

C:\test>junk6 -N=-10
             Rate        var   constant noconstant
var        2172/s         --       -18%       -21%
constant   2659/s        22%         --        -3%
noconstant 2746/s        26%         3%         --

C:\test>junk6 -N=-20
             Rate        var   constant noconstant
var        2171/s         --       -18%       -21%
constant   2632/s        21%         --        -5%
noconstant 2759/s        27%         5%         --