(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 2000 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: arch.ml,v 1.3 2007/01/01 13:07:35 xleroy Exp $ *)

(* Machine-specific command-line options *)

let pic_code = ref true

let command_line_options =
  [ "-fPIC", Arg.Set pic_code,
      " Generate position-independent machine code (default)";
    "-fno-PIC", Arg.Clear pic_code,
      " Generate position-dependent machine code" ]

(* Specific operations for the AMD64 processor *)

open Format

type addressing_mode =
    Ibased of string * int              (* symbol + displ *)
  | Iindexed of int                     (* reg + displ *)
  | Iindexed2 of int                    (* reg + reg + displ *)
  | Iscaled of int * int                (* reg * scale + displ *)
  | Iindexed2scaled of int * int        (* reg + reg * scale + displ *)

type specific_operation =
    Ilea of addressing_mode             (* "lea" gives scaled adds *)
  | Istore_int of nativeint * addressing_mode (* Store an integer constant *)
  | Istore_symbol of string * addressing_mode (* Store a symbol *)
  | Ioffset_loc of int * addressing_mode (* Add a constant to a location *)
  | Ifloatarithmem of float_operation * addressing_mode
                                       (* Float arith operation with memory *)
and float_operation =
    Ifloatadd | Ifloatsub | Ifloatmul | Ifloatdiv

(* Sizes, endianness *)

let big_endian = false

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

(* Operations on addressing modes *)

let identity_addressing = Iindexed 0

let offset_addressing addr delta =
  match addr with
    Ibased(s, n) -> Ibased(s, n + delta)
  | Iindexed n -> Iindexed(n + delta)
  | Iindexed2 n -> Iindexed2(n + delta)
  | Iscaled(scale, n) -> Iscaled(scale, n + delta)
  | Iindexed2scaled(scale, n) -> Iindexed2scaled(scale, n + delta)

let num_args_addressing = function
    Ibased(s, n) -> 0
  | Iindexed n -> 1
  | Iindexed2 n -> 2
  | Iscaled(scale, n) -> 1
  | Iindexed2scaled(scale, n) -> 2

(* Printing operations and addressing modes *)

let print_addressing printreg addr ppf arg =
  match addr with
  | Ibased(s, 0) ->
      fprintf ppf "\"%s\"" s
  | Ibased(s, n) ->
      fprintf ppf "\"%s\" + %i" s n
  | Iindexed n ->
      let idx = if n <> 0 then Printf.sprintf " + %i" n else "" in
      fprintf ppf "%a%s" printreg arg.(0) idx
  | Iindexed2 n ->
      let idx = if n <> 0 then Printf.sprintf " + %i" n else "" in
      fprintf ppf "%a + %a%s" printreg arg.(0) printreg arg.(1) idx
  | Iscaled(scale, n) ->
      let idx = if n <> 0 then Printf.sprintf " + %i" n else "" in
      fprintf ppf "%a  * %i%s" printreg arg.(0) scale idx
  | Iindexed2scaled(scale, n) ->
      let idx = if n <> 0 then Printf.sprintf " + %i" n else "" in
      fprintf ppf "%a + %a * %i%s" printreg arg.(0) printreg arg.(1) scale idx

let print_specific_operation printreg op ppf arg =
  match op with
  | Ilea addr -> print_addressing printreg addr ppf arg
  | Istore_int(n, addr) ->
      fprintf ppf "[%a] := %nd" (print_addressing printreg addr) arg n
  | Istore_symbol(lbl, addr) ->
      fprintf ppf "[%a] := \"%s\"" (print_addressing printreg addr) arg lbl
  | Ioffset_loc(n, addr) ->
      fprintf ppf "[%a] +:= %i" (print_addressing printreg addr) arg n
  | Ifloatarithmem(op, addr) ->
      let op_name = function
      | Ifloatadd -> "+f"
      | Ifloatsub -> "-f"
      | Ifloatmul -> "*f"
      | Ifloatdiv -> "/f" in
      fprintf ppf "%a %s float64[%a]" printreg arg.(0) (op_name op)
                   (print_addressing printreg addr)
                   (Array.sub arg 1 (Array.length arg - 1))
