@TheSeven: Just interested, but you fitted a complete unit (depth=6) into a v5lx110t?
Exactly, but with no additional registers, just the code that I have uploaded.
Gave it a try, but the default strategy already shows 250% LUTs after synthesis...
For the Virtex5 LX110?
I'm getting an area constraint ratio of ~200, but it fits at ~96% utilization in the end.