(* *********************************************************************)
(*                                                                     *)
(*              The Compcert verified compiler                         *)
(*                                                                     *)
(*          Xavier Leroy, INRIA Paris-Rocquencourt                     *)
(*          Jacques-Henri Jourdan, 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 GNU General Public License as published by  *)
(*  the Free Software Foundation, either version 2 of the License, or  *)
(*  (at your option) any later version.  This file is also distributed *)
(*  under the terms of the INRIA Non-Commercial License Agreement.     *)
(*                                                                     *)
(* *********************************************************************)

(** Architecture-dependent parameters for ARM *)

Require Import ZArith.
Require Import Fappli_IEEE.
Require Import Fappli_IEEE_bits.

Definition ptr64 := false.

Parameter big_endian: bool.

Definition align_int64 := 8%Z.
Definition align_float64 := 8%Z.

Definition splitlong := true.

Lemma splitlong_ptr32: splitlong = true -> ptr64 = false.
Proof.
  unfold splitlong, ptr64; congruence.
Qed.

Program Definition default_pl_64 : bool * nan_pl 53 :=
  (false, iter_nat 51 _ xO xH).

Definition choose_binop_pl_64 (s1: bool) (pl1: nan_pl 53) (s2: bool) (pl2: nan_pl 53) :=
  (** Choose second NaN if pl2 is sNaN but pl1 is qNan.
      In all other cases, choose first NaN *)
  (Pos.testbit (proj1_sig pl1) 51 &&
   negb (Pos.testbit (proj1_sig pl2) 51))%bool.

Program Definition default_pl_32 : bool * nan_pl 24 :=
  (false, iter_nat 22 _ xO xH).

Definition choose_binop_pl_32 (s1: bool) (pl1: nan_pl 24) (s2: bool) (pl2: nan_pl 24) :=
  (** Choose second NaN if pl2 is sNaN but pl1 is qNan.
      In all other cases, choose first NaN *)
  (Pos.testbit (proj1_sig pl1) 22 &&
   negb (Pos.testbit (proj1_sig pl2) 22))%bool.

Definition float_of_single_preserves_sNaN := false.

Global Opaque ptr64 big_endian splitlong
              default_pl_64 choose_binop_pl_64
              default_pl_32 choose_binop_pl_32
              float_of_single_preserves_sNaN.

(** Which ABI to use: either the standard ARM EABI with floats passed
  in integer registers, or the "hardfloat" variant of the EABI
  that uses FP registers instead. *)

Inductive abi_kind := Softfloat | Hardfloat.
Parameter abi: abi_kind.

(** Whether instructions added with Thumb2 are supported. True for ARMv6T2
  and above. *)
Parameter thumb2_support: bool.