(** Expressing 64-bit operations in terms of 32-bit operations *)

Lemma decompose_shr_1:
forall xh xl y,
0 <= Int.unsigned y < Int.zwordsize ->
shr' (ofwords xh xl) y =
ofwords (Int.shr xh y)
(Int.or (Int.shru xl y) (Int.shl xh (Int.sub Int.iwordsize y))).