(* *********************************************************************)
(*                                                                     *)
(*              The Compcert verified compiler                         *)
(*                                                                     *)
(*          Xavier Leroy, INRIA Paris-Rocquencourt                     *)
(*                                                                     *)
(*  Copyright Institut National de Recherche en Informatique et en     *)
(*  Automatique.  All rights reserved.  This file is distributed       *)
(*  under the terms of the INRIA Non-Commercial License Agreement.     *)
(*                                                                     *)
(* *********************************************************************)
(** Correctness proof for ARM code generation: auxiliary results. *)
Local Transparent Archi.ptr64.
(** Useful properties of the R14 registers. *)
Hint Resolve ireg_of_not_R14: asmgen.
Hint Resolve ireg_of_not_R14': asmgen.
(** [undef_flags] and [nextinstr_nf] *)
Definition if_preg (r: preg) : bool :=
match r with
| IR _ => true
| FR _ => true
| CR _ => false
| PC   => false
end.

Lemma if_preg_not_PC: forall r, if_preg r = true -> r <> PC.