ocaml/asmcomp/arm/arch.ml

265 lines
8.3 KiB
OCaml

(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Benedikt Meurer, University of Siegen *)
(* *)
(* Copyright 1998 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* Copyright 2012 Benedikt Meurer. *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
(* Specific operations for the ARM processor *)
open Format
type abi = EABI | EABI_HF
type arch = ARMv4 | ARMv5 | ARMv5TE | ARMv6 | ARMv6T2 | ARMv7 | ARMv8
type fpu = Soft | VFPv2 | VFPv3_D16 | VFPv3
let abi =
match Config.system with
"linux_eabi" | "freebsd" -> EABI
| "linux_eabihf" | "netbsd" -> EABI_HF
| _ -> assert false
let string_of_arch = function
ARMv4 -> "armv4"
| ARMv5 -> "armv5"
| ARMv5TE -> "armv5te"
| ARMv6 -> "armv6"
| ARMv6T2 -> "armv6t2"
| ARMv7 -> "armv7"
| ARMv8 -> "armv8"
let string_of_fpu = function
Soft -> "soft"
| VFPv2 -> "vfpv2"
| VFPv3_D16 -> "vfpv3-d16"
| VFPv3 -> "vfpv3"
(* Machine-specific command-line options *)
let (arch, fpu, thumb) =
let (def_arch, def_fpu, def_thumb) =
begin match abi, Config.model with
(* Defaults for architecture, FPU and Thumb *)
EABI, "armv5" -> ARMv5, Soft, false
| EABI, "armv5te" -> ARMv5TE, Soft, false
| EABI, "armv6" -> ARMv6, Soft, false
| EABI, "armv6t2" -> ARMv6T2, Soft, false
| EABI, "armv7" -> ARMv7, Soft, false
| EABI, "armv8" -> ARMv8, Soft, false
| EABI, _ -> ARMv4, Soft, false
| EABI_HF, "armv6" -> ARMv6, VFPv2, false
| EABI_HF, "armv8" -> ARMv8, VFPv3, true
| EABI_HF, _ -> ARMv7, VFPv3_D16, true
end in
(ref def_arch, ref def_fpu, ref def_thumb)
let farch spec =
arch := begin match spec with
"armv4" when abi <> EABI_HF -> ARMv4
| "armv5" when abi <> EABI_HF -> ARMv5
| "armv5te" when abi <> EABI_HF -> ARMv5TE
| "armv6" -> ARMv6
| "armv6t2" -> ARMv6T2
| "armv7" -> ARMv7
| "armv8" -> ARMv8
| spec -> raise (Arg.Bad ("wrong '-farch' option: " ^ spec))
end
let ffpu spec =
fpu := begin match spec with
"soft" when abi <> EABI_HF -> Soft
| "vfpv2" when abi = EABI_HF -> VFPv2
| "vfpv3-d16" when abi = EABI_HF -> VFPv3_D16
| "vfpv3" when abi = EABI_HF -> VFPv3
| spec -> raise (Arg.Bad ("wrong '-ffpu' option: " ^ spec))
end
let command_line_options =
[ "-farch", Arg.String farch,
"<arch> Select the ARM target architecture"
^ " (default: " ^ (string_of_arch !arch) ^ ")";
"-ffpu", Arg.String ffpu,
"<fpu> Select the floating-point hardware"
^ " (default: " ^ (string_of_fpu !fpu) ^ ")";
"-fPIC", Arg.Set Clflags.pic_code,
" Generate position-independent machine code";
"-fno-PIC", Arg.Clear Clflags.pic_code,
" Generate position-dependent machine code";
"-fthumb", Arg.Set thumb,
" Enable Thumb/Thumb-2 code generation"
^ (if !thumb then " (default)" else "");
"-fno-thumb", Arg.Clear thumb,
" Disable Thumb/Thumb-2 code generation"
^ (if not !thumb then " (default" else "")]
(* 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 * shift_operation * int
| Ishiftcheckbound of shift_operation * int
| Irevsubimm of int
| Imulhadd (* multiply high and add *)
| Imuladd (* multiply and add *)
| Imulsub (* multiply and subtract *)
| Inegmulf (* floating-point negate and multiply *)
| Imuladdf (* floating-point multiply and add *)
| Inegmuladdf (* floating-point negate, multiply and add *)
| Imulsubf (* floating-point multiply and subtract *)
| Inegmulsubf (* floating-point negate, multiply and subtract *)
| Isqrtf (* floating-point square root *)
| Ibswap of int (* endianness conversion *)
and arith_operation =
Ishiftadd
| Ishiftsub
| Ishiftsubrev
| Ishiftand
| Ishiftor
| Ishiftxor
and shift_operation =
Ishiftlogicalleft
| Ishiftlogicalright
| Ishiftarithmeticright
(* Sizes, endianness *)
let big_endian = false
let size_addr = 4
let size_int = 4
let size_float = 8
let allow_unaligned_access = false
(* Behavior of division *)
let division_crashes_on_overflow = false
(* Operations on addressing modes *)
let identity_addressing = Iindexed 0
let offset_addressing (Iindexed n) delta = Iindexed(n + delta)
let num_args_addressing (Iindexed _) = 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 shiftop_name = function
| Ishiftlogicalleft -> "<<"
| Ishiftlogicalright -> ">>u"
| Ishiftarithmeticright -> ">>s"
let print_specific_operation printreg op ppf arg =
match op with
Ishiftarith(op, shiftop, amount) ->
let (op1_name, op2_name) = match op with
Ishiftadd -> ("", "+")
| Ishiftsub -> ("", "-")
| Ishiftsubrev -> ("-", "+")
| Ishiftand -> ("", "&")
| Ishiftor -> ("", "|")
| Ishiftxor -> ("", "^") in
fprintf ppf "%s%a %s (%a %s %i)"
op1_name
printreg arg.(0)
op2_name
printreg arg.(1)
(shiftop_name shiftop)
amount
| Ishiftcheckbound(shiftop, amount) ->
fprintf ppf "check (%a %s %i) > %a"
printreg arg.(0)
(shiftop_name shiftop)
amount
printreg arg.(1)
| Irevsubimm n ->
fprintf ppf "%i %s %a" n "-" printreg arg.(0)
| Imulhadd ->
fprintf ppf "%a *h %a) + %a"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Imuladd ->
fprintf ppf "(%a * %a) + %a"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Imulsub ->
fprintf ppf "-(%a * %a) + %a"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Inegmulf ->
fprintf ppf "-f (%a *f %a)"
printreg arg.(0)
printreg arg.(1)
| Imuladdf ->
fprintf ppf "%a +f (%a *f %a)"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Inegmuladdf ->
fprintf ppf "%a -f (%a *f %a)"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Imulsubf ->
fprintf ppf "(-f %a) +f (%a *f %a)"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Inegmulsubf ->
fprintf ppf "(-f %a) -f (%a *f %a)"
printreg arg.(0)
printreg arg.(1)
printreg arg.(2)
| Isqrtf ->
fprintf ppf "sqrtf %a"
printreg arg.(0)
| Ibswap n ->
fprintf ppf "bswap%i %a" n
printreg arg.(0)
(* Recognize immediate operands *)
(* Immediate operands are 8-bit immediate values, zero-extended,
and rotated right by 0 ... 30 bits.
In Thumb/Thumb-2 mode we utilize 26 ... 30. *)
let is_immediate n =
let n = ref n in
let s = ref 0 in
let m = if !thumb then 24 else 30 in
while (!s <= m && Int32.logand !n 0xffl <> !n) do
n := Int32.logor (Int32.shift_right_logical !n 2) (Int32.shift_left !n 30);
s := !s + 2
done;
!s <= m