odd_1:  2 wallclock secs ( 1.70 usr +  0.00 sys =  1.70 CPU) @ 586854.46/s (n=1000000)
odd_2:  3 wallclock secs ( 1.67 usr +  0.00 sys =  1.67 CPU) @ 598086.12/s (n=1000000)

##</code><code>##

#!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)

##</code><code>##

>perl -MO=Deparse -we "$n=1231234;print $n % 2"
$n = 1231234;
print $n % 2;
-e syntax OK

>perl -MO=Deparse -we "$n=1231234;print $n & 1"
$n = 1231234;
print $n & 1;
-e syntax OK

>perl -MO=Deparse,-p -we "$n=1231234;print $n % 2"
($n = 1231234);
print(($n % 2));
-e syntax OK

>perl -MO=Deparse,-p -we "$n=1231234;print $n & 1"
($n = 1231234);
print(($n & 1));
-e syntax OK