#!perl -w
use strict;
use Benchmark;

timethese( 1_000_000, {
    odd_1 => sub { my $num = rand(2**31); return $num % 2 },
    odd_2 => sub { my $num = rand(2**31); return $num & 2 },
})
__END__
Benchmark: timing 1000000 iterations of odd_1, odd_2...
     odd_1:  3 wallclock secs ( 1.69 usr +  0.00 sys =  1.69 CPU) @ 592417.06/s
(n=1000000)
     odd_2:  3 wallclock secs ( 1.69 usr +  0.00 sys =  1.69 CPU) @ 592417.06/s
(n=1000000)