ocaml/asmcomp/mips/proc.ml

210 lines
6.6 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 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. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Description of the Mips processor *)
open Misc
open Cmm
open Reg
open Arch
open Mach
(* Instruction selection *)
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 - $f3 100 - 103 function results
$f4 - $f11 104 - 111 general purpose
$f12 - $f19 112 - 119 function arguments
$f20 - $f30 120 - 130 general purpose (even numbered preserved by C)
$f31 temporary *)
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"; "$21"
|]
let float_reg_name = [|
"$f0"; "$f1"; "$f2"; "$f3"; "$f4";
"$f5"; "$f6"; "$f7"; "$f8"; "$f9";
"$f10"; "$f11"; "$f12"; "$f13"; "$f14";
"$f15"; "$f16"; "$f17"; "$f18"; "$f19";
"$f20"; "$f21"; "$f22"; "$f23"; "$f24";
"$f25"; "$f26"; "$f27"; "$f28"; "$f29"; "$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; 31 |]
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.create 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.create 31 Reg.dummy in
for i = 0 to 30 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
make_stack arg =
let loc = Array.create (Array.length arg) Reg.dummy in
let int = ref first_int in
let float = ref first_float in
let ofs = ref 0 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 16) (* Keep stack 16-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 13 112 119 outgoing arg
let loc_parameters arg =
let (loc, ofs) = calling_conventions 6 13 112 119 incoming arg in loc
let loc_results res =
let (loc, ofs) = calling_conventions 0 5 100 103 not_supported res in loc
(* The C calling conventions are as follows:
the first 8 arguments are passed either in integer regs $4...$11
or float regs $f12...$f19. Each argument "consumes" both one slot
in the int register file and one slot in the float register file.
Extra arguments are passed on stack, in a 64-bits slot, right-justified
(i.e. at +4 from natural address). *)
let loc_external_arguments arg =
let loc = Array.create (Array.length arg) Reg.dummy in
let int = ref 2 in
let float = ref 112 in
let ofs = ref 0 in
for i = 0 to Array.length arg - 1 do
if i < 8 then begin
loc.(i) <- phys_reg (if arg.(i).typ = Float then !float else !int);
incr int;
incr float
end else begin
begin match arg.(i).typ with
Float -> loc.(i) <- stack_slot (Outgoing !ofs) Float
| ty -> loc.(i) <- stack_slot (Outgoing (!ofs + 4)) ty
end;
ofs := !ofs + 8
end
done;
(loc, Misc.align !ofs 16)
let loc_external_results res =
let (loc, ofs) = calling_conventions 0 0 100 100 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, $f22, $f24, $f26, $f28, $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;109;110;111;112;113;114;
115;116;117;118;119;121;123;125;127;129])
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; 31 |]
(* Layout of the stack *)
let num_stack_slots = [| 0; 0 |]
let contains_calls = ref false
(* Calling the assembler *)
let asm_command = "as -n32 -O2 -nocpp -g0 -o "
let assemble_file infile outfile =
Ccomp.command (asm_command ^ Filename.quote outfile ^ " " ^ Filename.quote infile)