Definition cmplu_bool (c: comparison) (v w: aval) : abool :=
  match v, w with
  | L i1, L i2 => Just (Int64.cmpu c i1 i2)
  | Ptr _, L i => if Int64.eq i Int64.zero then cmp_different_blocks c else Btop
  | L i, Ptr _ => if Int64.eq i Int64.zero then cmp_different_blocks c else Btop
  | Ptr p1, Ptr p2 => pcmp c p1 p2
  | _, _ => Btop
  end.

Lemma cmplu_bool_sound: forall valid c v w x y, vmatch v x -> vmatch w y -> cmatch (Val.cmplu_bool valid c v w) (cmplu_bool c x y).