my %map;

for my $i ( 0 .. 255 ) {
    my @Q = qw(0 0 0 0 0 0 0 0 0);
    my $result;
    #Step 1 : $Q[0] = D[0]
    $Q[0] = ($i & 0x01);

    #Step 2 : $Q[1] = D[1] ^ $Q[0]
    $Q[1] = (($i & 0x02) ^ ($Q[0] << 1));

    #Step 3 : $Q[2] = D[2] ^ $Q[1]
    $Q[2] = ($i & 0x04) ^ ($Q[1] << 1);

    #Step 4 : $Q[3] = D[3] ^ $Q[2]
    $Q[3] = ($i & 0x08) ^ ($Q[2] << 1);

    #Step 5 : $Q[4] = D[4] ^ $Q[3]
    $Q[4] = ($i & 0x10) ^ ($Q[3] << 1);

    #Step 6 : $Q[5] = D[5] ^ $Q[4]
    $Q[5] = ($i & 0x20) ^ ($Q[4] << 1);

    #Step 7 : $Q[6] = D[6] ^ $Q[5]
    $Q[6] = ($i & 0x40) ^ ($Q[5] << 1);

    #Step 8 : $Q[7] = D[7] ^ $Q[6]
    $Q[7] = ($i & 0x80) ^ ($Q[6] << 1);

    #Step 9 : $Q[8] = 1
    $Q[8] = 0x100;

    $result = ($Q[0] | $Q[1] | $Q[2] | $Q[3] | $Q[4] | $Q[5] | $Q[6] | $Q[7] | $Q[8]);
    $map{ $i } = $result;
    #print "$result ";
}

pp \%map;