Proof with eauto 10 with wd.
intros.
unfold compare_ints...
Qed.
Hint Resolve valid_val_compare_ints : wd.

(* Specifications: *)
Lemma valid_val_compare_longs:
forall f rs m v1 v2 r,
regset_wd f rs ->
valid_val f (compare_longs v1 v2 rs m r).