ocaml/asmcomp/arm/proc.ml

251 lines
8.0 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 Q *)
(* Public License version 1.0. *)
(* *)
(***********************************************************************)
(* Description of the ARM processor *)
open Misc
open Cmm
open Reg
open Arch
open Mach
(* Instruction selection *)
let word_addressed = false
(* Registers available for register allocation *)
(* Integer register map:
r0 - r3 general purpose (not preserved)
r4 - r7 general purpose (preserved)
r8 trap pointer (preserved)
r9 platform register, usually reserved
r10 allocation pointer (preserved)
r11 allocation limit (preserved)
r12 intra-procedural scratch register (not preserved)
r13 stack pointer
r14 return address
r15 program counter
Floating-point register map (VFPv{2,3}):
d0 - d7 general purpose (not preserved)
d8 - d15 general purpose (preserved)
d16 - d31 generat purpose (not preserved), VFPv3 only
*)
let int_reg_name =
[| "r0"; "r1"; "r2"; "r3"; "r4"; "r5"; "r6"; "r7"; "r12" |]
let float_reg_name =
[| "d0"; "d1"; "d2"; "d3"; "d4"; "d5"; "d6"; "d7";
"d8"; "d9"; "d10"; "d11"; "d12"; "d13"; "d14"; "d15";
"d16"; "d17"; "d18"; "d19"; "d20"; "d21"; "d22"; "d23";
"d24"; "d25"; "d26"; "d27"; "d28"; "d29"; "d30"; "d31" |]
(* We have three register classes:
0 for integer registers
1 for VFPv2 and VFPv3-D16
2 for VFPv3
This way we can choose between VFPv2/VFPv3-D16 and VFPv3
at (ocamlopt) runtime using command line switches.
*)
let num_register_classes = 3
let register_class r =
match (r.typ, !fpu) with
(Int | Addr), _ -> 0
| Float, VFPv2 -> 1
| Float, VFPv3_D16 -> 1
| Float, _ -> 2
let num_available_registers =
[| 9; 16; 32 |]
let first_available_register =
[| 0; 100; 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 9 Reg.dummy in
for i = 0 to 8 do
v.(i) <- Reg.at_location Int (Reg i)
done;
v
let hard_float_reg =
let v = Array.create 32 Reg.dummy in
for i = 0 to 31 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 ->
assert (abi = EABI_HF);
assert (!fpu >= VFPv2);
if !float <= last_float then begin
loc.(i) <- phys_reg !float;
incr float
end else begin
ofs := Misc.align !ofs size_float;
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"
(* OCaml calling convention:
first integer args in r0...r7
first float args in d0...d15 (EABI+VFP)
remaining args on stack.
Return values in r0...r7 or d0...d15. *)
let loc_arguments arg =
calling_conventions 0 7 100 115 outgoing arg
let loc_parameters arg =
let (loc, _) = calling_conventions 0 7 100 115 incoming arg in loc
let loc_results res =
let (loc, _) = calling_conventions 0 7 100 115 not_supported res in loc
(* C calling convention:
first integer args in r0...r3
first float args in d0...d7 (EABI+VFP)
remaining args on stack.
Return values in r0...r1 or d0. *)
let loc_external_arguments arg =
calling_conventions 0 3 100 107 outgoing arg
let loc_external_results res =
let (loc, _) = calling_conventions 0 1 100 100 not_supported res in loc
let loc_exn_bucket = phys_reg 0
(* Registers destroyed by operations *)
let destroyed_at_alloc = (* r0-r6, d0-d15 preserved *)
Array.of_list (List.map
phys_reg
[7;8;
116;116;118;119;120;121;122;123;
124;125;126;127;128;129;130;131])
let destroyed_at_c_call =
Array.of_list (List.map
phys_reg
(match abi with
EABI -> (* r4-r7 preserved *)
[0;1;2;3;8;
100;101;102;103;104;105;106;107;
108;109;110;111;112;113;114;115;
116;116;118;119;120;121;122;123;
124;125;126;127;128;129;130;131]
| EABI_HF -> (* r4-r7, d8-d15 preserved *)
[0;1;2;3;8;
100;101;102;103;104;105;106;107;
116;116;118;119;120;121;122;123;
124;125;126;127;128;129;130;131]))
let destroyed_at_oper = function
Iop(Icall_ind | Icall_imm _)
| Iop(Iextcall(_, true)) ->
all_phys_regs
| Iop(Iextcall(_, false)) ->
destroyed_at_c_call
| Iop(Ialloc _) ->
destroyed_at_alloc
| Iop(Iconst_symbol _) when !pic_code ->
[| phys_reg 3; phys_reg 8 |] (* r3 and r12 destroyed *)
| Iop(Iintop Imulh) when !arch < ARMv6 ->
[| phys_reg 8 |] (* r12 destroyed *)
| Iop(Iintoffloat | Ifloatofint | Iload(Single, _) | Istore(Single, _, _)) ->
[| phys_reg 107 |] (* d7 (s14-s15) destroyed *)
| _ -> [||]
let destroyed_at_raise = all_phys_regs
(* Maximal register pressure *)
let safe_register_pressure = function
Iextcall(_, _) -> if abi = EABI then 0 else 4
| Ialloc _ -> if abi = EABI then 0 else 7
| Iconst_symbol _ when !pic_code -> 7
| _ -> 9
let max_register_pressure = function
Iextcall(_, _) -> if abi = EABI then [| 4; 0; 0 |] else [| 4; 8; 8 |]
| Ialloc _ -> if abi = EABI then [| 7; 0; 0 |] else [| 7; 8; 8 |]
| Iconst_symbol _ when !pic_code -> [| 7; 16; 32 |]
| Iintoffloat | Ifloatofint
| Iload(Single, _) | Istore(Single, _, _) -> [| 9; 15; 31 |]
| _ -> [| 9; 16; 32 |]
(* Pure operations (without any side effect besides updating their result
registers). *)
let op_is_pure = function
| Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
| Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
| Iintop(Icheckbound) | Iintop_imm(Icheckbound, _)
| Ispecific(Ishiftcheckbound _) -> false
| _ -> true
(* Layout of the stack *)
let num_stack_slots = [| 0; 0; 0 |]
let contains_calls = ref false
(* Calling the assembler *)
let assemble_file infile outfile =
Ccomp.command (Config.asm ^ " -o " ^
Filename.quote outfile ^ " " ^ Filename.quote infile)
let init () = ()