Is an Opteron backend for ocamlopt in the works?

Given that we deal with very large graphs here at
Overture (an internet search company), I have been
frustrated by Ocaml's 2^22 maximum dimension for
native arrays on a 32-bit machine.

I tried using our 64-bit Itanium, but it is 10 times
slower than our 32-bit Intel machines, so I have stuck
with the latter using ugly workarounds like 2-level native
arrays and bigarrays of integer indexes.

BTW, we don't actually have an Opteron box yet, but it is
quite likely that we will be getting one.