> This is probably the solution.  it's unclear that ANSI will support
> 64bit ints in any reasonable fashion, though.

Uh, to what extent does ANSI not support 64 bit ints in any reasonable fashion?
SOME of us use 64-bit machines daily with ANSI C.  Granted, there's a lot of
_code_ that breaks if run on anything more modern than a VAX 11/780 due to
assuming sizeof(int)==sizeof(long)==sizeof(char *), but that isn't ANSI's
fault.

(Or do you mean that ANSI doesn't reasonably support 64-bit integers on
32-bit machines, where "long" is not naturally 64 bits?)