Hint Resolve new_reg_target_ok alloc_reg_target_ok
alloc_regs_target_ok: rtlg.
(** The following predicate is a variant of [target_reg_ok] used to characterize registers that are adequate for holding the return value of a function. *)
Inductive return_reg_ok: state -> mapping -> option reg -> Prop :=
| return_reg_ok_none:
forall s map,
return_reg_ok s map None
| return_reg_ok_some:
forall s map r,
~(reg_in_map map r) -> reg_valid r s ->
return_reg_ok s map (Some r).

(* Specifications: *)
Lemma return_reg_ok_incr:
forall s map rret, return_reg_ok s map rret ->
forall s', state_incr s s' -> return_reg_ok s' map rret.