Parsing 64-bit ints in 32-bit OCaml

[Jon Harrop <jon@ffconsultancy.com>]

I'm just trying to write efficient functions for div and mod by three. I'd 
like to handle 32- and 64-bit machines with the same code so I tried:

  let gcd3 = match Sys.word_size with
    | 32 -> 715827883
    | 64 -> 3074457345618258603
    | _ -> failwith "Unknown word size"

That works perfectly in 64-bit but breaks OCaml's parser in 32-bit, which dies 
with:

  Integer literal exceeds the range of representable integers of type int

As a workaround, I replaced it with:

  | 64 -> Int64.to_int 3074457345618258603L

Is there a better workaround?

-- 
Dr Jon Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/?e