348 lines
11 KiB
OCaml
348 lines
11 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Description of the Motorola 68020 processor *)
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open Misc
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open Arch
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open Format
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open Cmm
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open Reg
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open Mach
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(* Registers available for register allocation *)
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(* Register map:
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A0 - A6 0-6 address registers (A2-A6 callee-save)
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A7 stack pointer
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D0 - D4 7-11 data registers (D2 - D7 callee-save)
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D5 temporary
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D6 allocation pointer
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D7 trap pointer
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FP0 - FP7 12-19 floating-point registers (FP2 - FP7 callee-save)
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*)
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let register_names =
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[| "a0"; "a1"; "a2"; "a3"; "a4"; "a5"; "a6";
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"d0"; "d1"; "d2"; "d3"; "d4";
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"fp0"; "fp1"; "fp2"; "fp3"; "fp4"; "fp5"; "fp6"; "fp7" |]
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let num_register_classes = 3
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let register_class r =
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match r.typ with
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Addr -> 0
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| Int -> 1
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| Float -> 2
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let num_available_registers = [| 7; 5; 8 |]
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let first_available_register = [| 0; 7; 12 |]
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let register_name r = register_names.(r)
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(* There is no scheduling, so just pack registers. *)
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let rotate_registers = false
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(* Representation of hard registers by pseudo-registers *)
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let all_phys_regs =
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let v = Array.create 20 Reg.dummy in
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for i = 0 to 6 do v.(i) <- Reg.at_location Addr (Reg i) done;
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for i = 7 to 11 do v.(i) <- Reg.at_location Int (Reg i) done;
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for i = 12 to 19 do v.(i) <- Reg.at_location Float (Reg i) done;
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v
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let phys_reg n = all_phys_regs.(n)
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let stack_slot slot ty = Reg.at_location ty (Stack slot)
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let reg_A0 = phys_reg 0
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let reg_FP0 = phys_reg 12
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(* Exceptions raised to signal cases not handled here *)
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exception Use_default
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(* Instruction selection *)
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(* Auxiliary for recognizing addressing modes *)
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type addressing_expr =
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Asymbol of string
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| Alinear of expression
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| Aadd of expression * expression
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| Ascale of expression * int
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| Ascaledadd of expression * expression * int
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let rec select_addr exp =
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match exp with
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Cconst_symbol s ->
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(Asymbol s, 0)
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| Cop((Caddi | Cadda), [arg; Cconst_int m]) ->
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let (a, n) = select_addr arg in (a, n + m)
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| Cop((Csubi | Csuba), [arg; Cconst_int m]) ->
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let (a, n) = select_addr arg in (a, n - m)
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| Cop((Caddi | Cadda), [Cconst_int m; arg]) ->
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let (a, n) = select_addr arg in (a, n + m)
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| Cop(Clsl, [arg; Cconst_int(1|2|3 as shift)]) ->
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begin match select_addr arg with
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(Alinear e, n) -> (Ascale(e, 1 lsl shift), n lsl shift)
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| _ -> (Alinear exp, 0)
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end
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| Cop(Cmuli, [arg; Cconst_int(2|4|8 as mult)]) ->
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begin match select_addr arg with
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(Alinear e, n) -> (Ascale(e, mult), n * mult)
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| _ -> (Alinear exp, 0)
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end
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| Cop(Cmuli, [Cconst_int(2|4|8 as mult); arg]) ->
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begin match select_addr arg with
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(Alinear e, n) -> (Ascale(e, mult), n * mult)
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| _ -> (Alinear exp, 0)
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end
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| Cop((Caddi | Cadda), [arg1; arg2]) ->
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begin match (select_addr arg1, select_addr arg2) with
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((Alinear e1, n1), (Alinear e2, n2)) ->
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(Aadd(e1, e2), n1 + n2)
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| ((Alinear e1, n1), (Ascale(e2, scale), n2)) ->
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(Ascaledadd(e1, e2, scale), n1 + n2)
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| ((Ascale(e1, scale), n1), (Alinear e2, n2)) ->
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(Ascaledadd(e2, e1, scale), n1 + n2)
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| (_, (Ascale(e2, scale), n2)) ->
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(Ascaledadd(arg1, e2, scale), n2)
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| ((Ascale(e1, scale), n1), _) ->
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(Ascaledadd(arg2, e1, scale), n1)
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| _ ->
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(Aadd(arg1, arg2), 0)
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end
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| arg ->
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(Alinear arg, 0)
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let select_addressing exp =
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match select_addr exp with
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(Asymbol s, d) ->
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(Ibased(s, d), Ctuple [])
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| (Alinear e, d) ->
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(Iindexed d, e)
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| (Aadd(e1, e2), d) ->
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(Iindexed2 d, Ctuple[e1; e2])
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| (Ascale(e, scale), d) ->
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(Iscaled(scale, d), e)
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| (Ascaledadd(e1, e2, scale), d) ->
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(Iindexed2scaled(scale, d), Ctuple[e1; e2])
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(* Selection of immediate shifts *)
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let select_shift op args =
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match args with
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[arg1; Cconst_int n] when n >= 1 && n <= 8 -> (Iintop_imm(op, n), [arg1])
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| _ -> (Iintop op, args)
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(* Main instruction selection functions *)
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let select_oper op args =
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match op with
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(* Recognize the LEA instruction *)
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Cadda | Csuba ->
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begin match select_addressing (Cop(op, args)) with
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(Iindexed d, _) -> raise Use_default
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| (addr, arg) -> (Ispecific(Ilea addr), [arg])
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end
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(* Recognize immediate shifts only if 1 <= count <= 8 *)
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| Clsl -> select_shift Ilsl args
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| Clsr -> select_shift Ilsr args
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| Casr -> select_shift Iasr args
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(* Recognize store instructions *)
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| Cstore ->
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begin match args with
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[loc; Cconst_int n] ->
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let (addr, arg) = select_addressing loc in
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(Ispecific(Istore_int(n, addr)), [arg])
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| [loc; Cconst_pointer n] ->
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let (addr, arg) = select_addressing loc in
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(Ispecific(Istore_int(n, addr)), [arg])
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| [loc; Cconst_symbol s] ->
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let (addr, arg) = select_addressing loc in
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(Ispecific(Istore_symbol(s, addr)), [arg])
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| _ ->
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raise Use_default
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end
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| _ -> raise Use_default
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let select_store addr exp =
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match exp with
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Cconst_int n -> (Ispecific(Istore_int(n, addr)), Ctuple [])
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| Cconst_pointer n -> (Ispecific(Istore_int(n, addr)), Ctuple [])
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| Cconst_symbol s -> (Ispecific(Istore_symbol(s, addr)), Ctuple [])
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| _ -> raise Use_default
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let select_push exp =
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match exp with
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Cconst_int n -> (Ispecific(Ipush_int n), Ctuple [])
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| Cconst_pointer n -> (Ispecific(Ipush_int n), Ctuple [])
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| Cconst_symbol s -> (Ispecific(Ipush_symbol s), Ctuple [])
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| Cop(Cload ty, [loc]) when ty = typ_float ->
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let (addr, arg) = select_addressing loc in
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(Ispecific(Ipush_load_float addr), arg)
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| Cop(Cload ty, [loc]) when ty = typ_addr or ty = typ_int ->
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let (addr, arg) = select_addressing loc in
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(Ispecific(Ipush_load addr), arg)
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| _ -> (Ispecific(Ipush), exp)
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let pseudoregs_for_operation op arg res =
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match op with
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(* Two-address binary operations *)
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Iintop(Iadd | Isub | Imul | Idiv | Imod | Ilsl | Ilsr | Iasr) |
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Iaddf | Isubf | Imulf | Idivf ->
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([|res.(0); arg.(1)|], res, false)
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(* Two-address binary operations, forcing the second argument to be
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in a data register *)
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| Iintop(Iand | Ior | Ixor) ->
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let newarg1 = Reg.create Int in
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([|res.(0); newarg1|], res, false)
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(* Two-address unary operations *)
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| Iintop_imm((Iadd | Isub | Imul | Idiv | Imod | Iand | Ior | Ixor |
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Ilsl | Ilsr | Iasr), _) ->
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(res, res, false)
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(* Other instructions are regular *)
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| _ -> raise Use_default
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let is_immediate (n: int) = true
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let word_addressed = false
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(* Calling conventions *)
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let calling_conventions first_addr last_addr first_float last_float
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make_stack arg =
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let loc = Array.create (Array.length arg) Reg.dummy in
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let addr = ref first_addr in
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let float = ref first_float in
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let ofs = ref 0 in
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for i = 0 to Array.length arg - 1 do
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match arg.(i).typ with
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(Addr | Int) as ty ->
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if !addr <= last_addr then begin
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loc.(i) <- phys_reg !addr;
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incr addr
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end else begin
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loc.(i) <- stack_slot (make_stack !ofs) ty;
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ofs := !ofs + size_addr
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end
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| Float ->
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if !float <= last_float then begin
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loc.(i) <- phys_reg !float;
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incr float
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end else begin
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loc.(i) <- stack_slot (make_stack !ofs) Float;
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ofs := !ofs + size_float
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end
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done;
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(loc, !ofs)
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let incoming ofs = Incoming ofs
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let outgoing ofs = Outgoing ofs
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let not_supported ofs = fatal_error "Proc.loc_results: cannot call"
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let loc_arguments arg =
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calling_conventions 0 5 12 18 outgoing arg
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let loc_parameters arg =
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let (loc, ofs) = calling_conventions 0 5 12 18 incoming arg in loc
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let loc_results res =
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let (loc, ofs) = calling_conventions 0 5 12 18 not_supported res in loc
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let extcall_use_push = true
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let loc_external_arguments arg =
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fatal_error "Proc.loc_external_arguments"
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let loc_external_results res =
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let (loc, ofs) = calling_conventions 7 7 12 12 not_supported res in loc
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let loc_exn_bucket = reg_A0
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(* Registers destroyed by operations *)
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let destroyed_at_c_call =
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Array.of_list(List.map phys_reg [0; 1; 7; 8; 12; 13])
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let destroyed_at_oper = function
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Iop(Icall_ind | Icall_imm _ | Iextcall(_, true)) -> all_phys_regs
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| Iop(Iextcall(_, false)) -> destroyed_at_c_call
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| Iop(Iintoffloat) -> [| reg_FP0 |]
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| _ -> [||]
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let destroyed_at_raise = all_phys_regs
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(* Maximal register pressure *)
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let safe_register_pressure op = 5
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let max_register_pressure = function
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Iextcall(_, _) -> [| 5; 3; 6 |]
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| Iintoffloat -> [| 7; 5; 7 |]
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| _ -> num_available_registers
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(* Reloading of instruction arguments, storing of instruction results. *)
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let stackp r =
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match r.loc with
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Stack _ -> true
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| _ -> false
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let reload_test makereg round tst arg =
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match tst with
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Iinttest _ | Ifloattest _ ->
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(* The second argument can be on stack *)
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[| makereg arg.(0); arg.(1) |]
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| _ ->
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(* The argument can be on stack *)
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arg
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let reload_operation makereg round op arg res =
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match op with
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Imove | Ireload | Ispill |
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Iintop_imm((Iadd | Isub | Iand | Ior | Ixor |
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Icomp _ | Ilsl | Ilsr | Iasr), _) |
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Ifloatofint | Iintoffloat | Ispecific(Ipush) ->
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(* The argument(s) can be either in register or on stack *)
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(arg, res)
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| Iintop(Iadd | Isub | Iand | Ior | Ixor | Icomp _) ->
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(* One of the two arguments can reside in the stack *)
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if stackp arg.(0) && stackp arg.(1)
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then ([|arg.(0); makereg arg.(1)|], res)
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else (arg, res)
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| Iintop(Ilsl | Ilsr | Iasr) ->
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(* The first argument and result can reside in the stack *)
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([|arg.(0); makereg arg.(1)|], res)
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| Iintop(Imul | Idiv | Imod) | Iaddf | Isubf | Imulf | Idivf ->
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(* The second argument can reside in the stack *)
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let r = makereg arg.(0) in ([|r; arg.(1)|], [|r|])
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| _ -> (* Other operations: all args and results in registers *)
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raise Use_default
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(* Scheduling is turned off. *)
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let need_scheduling = false
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let oper_latency _ = 0
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(* Layout of the stack frame *)
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let num_stack_slots = [| 0; 0; 0 |]
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let contains_calls = ref false
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(* Calling the assembler *)
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let assemble_file infile outfile =
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Sys.command ("as -o " ^ outfile ^ " " ^ infile)
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