Hint Resolve make_cast_int_correct make_longofint_correct: cshm.
Ltac InvEval :=
match goal with
| [ H: None = Some _ |- _ ] => discriminate
| [ H: Some _ = Some _ |- _ ] => inv H; InvEval
| [ H: match ?x with Some _ => _ | None => _ end = Some _ |- _ ] => destruct x eqn:?; InvEval
| [ H: match ?x with true => _ | false => _ end = Some _ |- _ ] => destruct x eqn:?; InvEval
| _ => idtac
end.

Lemma make_cast_correct:
forall e le m a b v ty1 ty2 v',
make_cast ty1 ty2 a = OK b ->
eval_expr ge e le m a v ->
sem_cast v ty1 ty2 m = Some v' ->
eval_expr ge e le m b v'.