(** 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 from_words_value: forall x, B2R _ _ (from_words ox4330_0000 x) = (bpow radix2 52 + Z2R (Int.unsigned x))%R /\ is_finite _ _ (from_words ox4330_0000 x) = true /\ Bsign _ _ (from_words ox4330_0000 x) = false.