ocaml/asmcomp/arm/arch.ml

(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 1998 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

(* Specific operations for the ARM processor *)

open Misc
open Format

(* Addressing modes *)

type addressing_mode =
    Iindexed of int                     (* reg + displ *)

(* We do not support the reg + shifted reg addressing mode, because
   what we really need is reg + shifted reg + displ,
   and this is decomposed in two instructions (reg + shifted reg -> tmp,
   then addressing tmp + displ). *)

(* Specific operations *)

type specific_operation =
    Ishiftarith of arith_operation * int
  | Ishiftcheckbound of int
  | Irevsubimm of int

and arith_operation =
    Ishiftadd
  | Ishiftsub
  | Ishiftsubrev

(* Sizes, endianness *)

let big_endian = false

let size_addr = 4
let size_int = 4
let size_float = 8

(* Operations on addressing modes *)

let identity_addressing = Iindexed 0

let offset_addressing (Iindexed n) delta = Iindexed(n + delta)

let num_args_addressing (Iindexed n) = 1

(* Printing operations and addressing modes *)

let print_addressing printreg addr ppf arg =
  match addr with
  | Iindexed n ->
      printreg ppf arg.(0);
      if n <> 0 then fprintf ppf " + %i" n

let print_specific_operation printreg op ppf arg =
  match op with
  | Ishiftarith(op, shift) ->
      let op_name = function
      | Ishiftadd -> "+"
      | Ishiftsub -> "-"
      | Ishiftsubrev -> "-rev" in
      let shift_mark =
       if shift >= 0
       then sprintf "<< %i" shift
       else sprintf ">> %i" (-shift) in
      fprintf ppf "%a %s %a %s"
       printreg arg.(0) (op_name op) printreg arg.(1) shift_mark
  | Ishiftcheckbound n ->
      fprintf ppf "check %a >> %i > %a" printreg arg.(0) n printreg arg.(1)
  | Irevsubimm n ->
      fprintf ppf "%i %s %a" n "-" printreg arg.(0)