(** ** Abstract operations over value needs. *)

Ltac InvAgree :=
  simpl vagree in *;
  repeat (
  auto || exact Logic.I ||
  match goal with
  | [ H: False |- _ ] => contradiction
  | [ H: match ?v with Vundef => _ | Vint _ => _ | Vlong _ => _ | Vfloat _ => _ | Vsingle _ => _ | Vptr _ _ => _ end |- _ ] => destruct v
  | [ |- context [if Archi.ptr64 then _ else _] ] => destruct Archi.ptr64 eqn:?
  end).(** And immediate, or immediate *)

Definition andimm (x: nval) (n: int) :=
  match x with
  | Nothing => Nothing
  | I m => I (Int.and m n)
  | All => I n
  end.

Lemma andimm_sound: forall v w x n, vagree v w (andimm x n) -> vagree (Val.and v (Vint n)) (Val.and w (Vint n)) x.