(** Conversions from ints to floats can be defined as bitwise manipulations
  over the in-memory representation.  This is what the PowerPC port does.
  The trick is that [from_words 0x4330_0000 x] is the float
  [2^52 + of_intu x]. *)

Definition ox4330_0000 := Int.repr 1127219200.

Lemma split_bits_or: forall x, split_bits 52 11 (Int64.unsigned (Int64.ofwords ox4330_0000 x)) = (false, Int.unsigned x, 1075).