use constant A => 0;
use constant B => 1;
use constant C => 2;

sub mix ($$$) {
	use integer;
	$_[A] -= $_[B]; $_[A] -= $_[C]; $_[A] ^= ($_[C]>>13);
	$_[B] -= $_[C]; $_[B] -= $_[A]; $_[B] ^= ($_[A]<< 8);
	$_[C] -= $_[A]; $_[C] -= $_[B]; $_[C] ^= ($_[B]>>13);
	$_[A] -= $_[B]; $_[A] -= $_[C]; $_[A] ^= ($_[C]>>12);
	$_[B] -= $_[C]; $_[B] -= $_[A]; $_[B] ^= ($_[A]<<16);
	$_[C] -= $_[A]; $_[C] -= $_[B]; $_[C] ^= ($_[B]>> 5);
	$_[A] -= $_[B]; $_[A] -= $_[C]; $_[A] ^= ($_[C]>> 3);
	$_[B] -= $_[C]; $_[B] -= $_[A]; $_[B] ^= ($_[A]<<10);
	$_[C] -= $_[A]; $_[C] -= $_[B]; $_[C] ^= ($_[B]>>15);
}

use constant GOLDEN_RATIO	=> 0x9e3779b9;
use constant INITHASH		=> 2;

sub hash {
	use integer;
	my($a,$b,$c) = (GOLDEN_RATIO, GOLDEN_RATIO, $_[INITHASH]);
	my ($p, $len) = (0, length $_[KEY]);
	do {
		my($x,$y,$z) = unpack 'V3', substr($_[KEY] . (chr(0)x11), $p, 12);
		mix($a += $x, $b += $y, $c += $z + $len);
		$p+=12;
	} while $p <= $len;
	return $c;
}