Proof (binop_single_sound Float32.div).
(** Conversions *)
Definition zero_ext (nbits: Z) (v: aval) :=
match v with
| I i => I (Int.zero_ext nbits i)
| Uns p n => uns p (Z.min n nbits)
| _ => uns (provenance v) nbits
end.

Lemma zero_ext_sound:
forall nbits v x, vmatch v x -> vmatch (Val.zero_ext nbits v) (zero_ext nbits x).