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

{
    use bigint; 
    
    # code that needs bigint
    my $r = 0x234;
    my $t = 0x345;
    my $x1 = $r << 32 | $t;
    #print $x1->as_hex;

    # other stuff that doesn't...
    #   => unnecessarily slow!
    sub with_bigint {
        my $x = 1;
        $x = $x * 4 / 2 - 1 for 1..1000;
    }

} # end of bigint

sub no_bigint {
    my $x = 1;
    $x = $x * 4 / 2 - 1 for 1..1000;
}

cmpthese (-1,
    {
        with_bigint => \&with_bigint,
        no_bigint   => \&no_bigint,
    },
);

__END__
              Rate with_bigint   no_bigint
with_bigint 11.3/s          --       -100%
no_bigint   4073/s      35876%          --