ocaml/asmcomp/proc_mips.ml

241 lines
7.4 KiB
OCaml

(***********************************************************************)
(* *)
(* Caml Special Light *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1995 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Description of the Mips processor *)
open Misc
open Cmm
open Reg
open Arch
open Mach
(* Exceptions raised to signal cases not handled here *)
exception Use_default
(* Instruction selection *)
let select_addressing = function
Cconst_symbol s ->
(Ibased(s, 0), Ctuple [])
| Cop(Cadda, [Cconst_symbol s; Cconst_int n]) ->
(Ibased(s, n), Ctuple [])
| Cop(Cadda, [arg; Cconst_int n]) ->
(Iindexed n, arg)
| Cop(Cadda, [arg1; Cop(Caddi, [arg2; Cconst_int n])]) ->
(Iindexed n, Cop(Cadda, [arg1; arg2]))
| arg ->
(Iindexed 0, arg)
let select_oper op args = raise Use_default
let select_store addr exp = raise Use_default
let pseudoregs_for_operation op arg res = raise Use_default
let is_immediate (n:int) = true
let word_addressed = false
(* Registers available for register allocation *)
(* Register map:
$0 always 0
$1 temporary for the assembler
$2 - $7 0 - 5 function results
$8 - $15 6 - 13 function arguments
$16 - $21 14 - 19 general purpose (preserved by C)
$22 allocation pointer (preserved by C)
$23 allocation limit (preserved by C)
$24 - $25 temporaries
$26 - $29 kernel regs, stack pointer, global pointer
$30 trap pointer (preserved by C)
$31 return address
$f0 - $f8 100 - 104 function results
$f10 temporary
$f12 - $f18 105 - 108 function arguments
$f20 - $f30 109 - 114 general purpose (preserved by C) *)
let int_reg_name = [|
(* 0-5 *) "$2"; "$3"; "$4"; "$5"; "$6"; "$7";
(* 6-13 *) "$8"; "$9"; "$10"; "$11"; "$12"; "$13"; "$14"; "$15";
(* 14-19 *) "$16"; "$17"; "$18"; "$19"; "$20"; "$21"
|]
let float_reg_name = [|
(* 100-104 *) "$f0"; "$f2"; "$f4"; "$f6"; "$f8";
(* 105-108 *) "$f12"; "$f14"; "$f16"; "$f18";
(* 109-114 *) "$f20"; "$f22"; "$f24"; "$f26"; "$f28"; "$f30"
|]
let num_register_classes = 2
let register_class r =
match r.typ with
Int -> 0
| Addr -> 0
| Float -> 1
let num_available_registers = [| 20; 15 |]
let first_available_register = [| 0; 100 |]
let register_name r =
if r < 100 then int_reg_name.(r) else float_reg_name.(r - 100)
let rotate_registers = true
(* Representation of hard registers by pseudo-registers *)
let hard_int_reg =
let v = Array.new 20 Reg.dummy in
for i = 0 to 19 do v.(i) <- Reg.at_location Int (Reg i) done;
v
let hard_float_reg =
let v = Array.new 15 Reg.dummy in
for i = 0 to 14 do v.(i) <- Reg.at_location Float (Reg(100 + i)) done;
v
let all_phys_regs =
Array.append hard_int_reg hard_float_reg
let phys_reg n =
if n < 100 then hard_int_reg.(n) else hard_float_reg.(n - 100)
let stack_slot slot ty =
Reg.at_location ty (Stack slot)
(* Calling conventions *)
let calling_conventions first_int last_int first_float last_float
initial_stack_ofs make_stack arg =
let loc = Array.new (Array.length arg) Reg.dummy in
let int = ref first_int in
let float = ref first_float in
let ofs = ref initial_stack_ofs in
for i = 0 to Array.length arg - 1 do
match arg.(i).typ with
Int | Addr as ty ->
if !int <= last_int then begin
loc.(i) <- phys_reg !int;
incr int
end else begin
loc.(i) <- stack_slot (make_stack !ofs) ty;
ofs := !ofs + size_int
end
| Float ->
if !float <= last_float then begin
loc.(i) <- phys_reg !float;
incr float
end else begin
loc.(i) <- stack_slot (make_stack !ofs) Float;
ofs := !ofs + size_float
end
done;
(loc, Misc.align !ofs 8) (* Keep stack 8-aligned *)
let incoming ofs = Incoming ofs
let outgoing ofs = Outgoing ofs
let not_supported ofs = fatal_error "Proc.loc_results: cannot call"
let loc_arguments arg =
calling_conventions 6 13 105 108 0 outgoing arg
let loc_parameters arg =
let (loc, ofs) = calling_conventions 6 13 105 108 0 incoming arg in loc
let loc_results res =
let (loc, ofs) = calling_conventions 0 5 100 104 0 not_supported res in loc
(* The C compiler calling conventions are peculiar, especially when
a mix of ints and floats are passed. Here, we trap a few special
cases and revert to [calling_conventions] when only scalars are
passed. *)
let loc_external_arguments arg =
try
for i = 0 to Array.length arg - 1 do
if arg.(i).typ = Float then raise Exit
done;
(* Always reserve 4 words at the bottom of the stack *)
calling_conventions 2 5 0 0 16 outgoing arg
with Exit ->
match Array.to_list(Array.map register_class arg) with
[1] -> (* $f12 *)
[| phys_reg 105 |], 16
| [1;1] -> (* $f12, $f14 *)
[| phys_reg 105; phys_reg 106 |], 16
| [1;0] -> (* $f12, $6 *)
[| phys_reg 105; phys_reg 4 |], 16
| [0;1] -> (* $4, $6 (needs fpreg -> $6,$7 move) *)
[| phys_reg 2; phys_reg 4 |], 16
| [0;0;1] -> (* $4, $5, $6 (ditto) *)
[| phys_reg 2; phys_reg 3; phys_reg 4 |], 16
| _ ->
fatal_error "Proc_mips.loc_external_arguments"
let loc_external_results res =
let (loc, ofs) = calling_conventions 0 0 100 100 0 not_supported res in loc
let loc_exn_bucket = phys_reg 0 (* $2 *)
(* Registers destroyed by operations *)
let destroyed_at_c_call = (* $16 - $21, $f20 - $f30 preserved *)
Array.of_list(List.map phys_reg
[0;1;2;3;4;5;6;7;8;9;10;11;12;13;
100;101;102;103;104;105;106;107;108])
let destroyed_at_oper = function
Iop(Icall_ind | Icall_imm _ | Iextcall(_, true)) -> all_phys_regs
| Iop(Iextcall(_, false)) -> destroyed_at_c_call
| _ -> [||]
let destroyed_at_raise = all_phys_regs
(* Maximal register pressure *)
let safe_register_pressure = function
Iextcall(_, _) -> 6
| _ -> 20
let max_register_pressure = function
Iextcall(_, _) -> [| 6; 6 |]
| _ -> [| 20; 15 |]
(* Reloading *)
let reload_test makereg tst args = raise Use_default
let reload_operation makereg op args res = raise Use_default
(* No scheduling is needed, the assembler does it better than us. *)
let need_scheduling = false
let oper_latency _ = 1
(* Layout of the stack *)
let num_stack_slots = [| 0; 0 |]
let contains_calls = ref false
(* Calling the assembler *)
let assemble_file infile outfile =
Sys.command ("as -O2 -o " ^ outfile ^ " " ^ infile)
(* Calling the archiver *)
let create_archive archive file_list =
Misc.remove_file archive;
Sys.command ("ar rcs " ^ archive ^ " " ^ String.concat " " file_list)