(** ** Properties of [agree_locs] *)
(** Preservation under assignment of machine register. *)

Lemma agree_locs_undef_locs_1:
forall ls0 regs ls,
agree_locs ls ls0 ->
(forall r, In r regs -> is_callee_save r = false) ->
agree_locs (LTL.undef_regs regs ls) ls0.