ocaml/bytecomp/emitcode.ml

327 lines
11 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Generation of bytecode + relocation information *)
open Config
open Misc
open Asttypes
open Lambda
open Instruct
open Opcodes
(* Relocation information *)
type reloc_info =
Reloc_literal of structured_constant (* structured constant *)
| Reloc_getglobal of Ident.t (* reference to a global *)
| Reloc_setglobal of Ident.t (* definition of a global *)
| Reloc_primitive of string (* C primitive number *)
(* Descriptor for compilation units *)
type compilation_unit =
{ cu_name: string; (* Name of compilation unit *)
mutable cu_pos: int; (* Absolute position in file *)
cu_codesize: int; (* Size of code block *)
cu_reloc: (reloc_info * int) list; (* Relocation information *)
cu_interface: Digest.t; (* CRC of interface implemented *)
cu_imports: (string * Digest.t) list; (* Names and CRC of intfs imported *)
cu_primitives: string list; (* Primitives declared inside *)
mutable cu_force_link: bool; (* Must be linked even if unref'ed *)
cu_events: debug_event list } (* Debugging events *)
(* Format of a .cmo file:
magic number (Config.cmo_magic_number)
absolute offset of compilation unit descriptor
block of relocatable bytecode
compilation unit descriptor *)
(* Buffering of bytecode *)
let out_buffer = ref(String.create 1024)
and out_position = ref 0
let out_word b1 b2 b3 b4 =
let p = !out_position in
if p >= String.length !out_buffer then begin
let len = String.length !out_buffer in
let new_buffer = String.create (2 * len) in
String.blit !out_buffer 0 new_buffer 0 len;
out_buffer := new_buffer
end;
String.unsafe_set !out_buffer p (Char.unsafe_chr b1);
String.unsafe_set !out_buffer (p+1) (Char.unsafe_chr b2);
String.unsafe_set !out_buffer (p+2) (Char.unsafe_chr b3);
String.unsafe_set !out_buffer (p+3) (Char.unsafe_chr b4);
out_position := p + 4
let out opcode =
out_word opcode 0 0 0
let out_int n =
out_word n (n asr 8) (n asr 16) (n asr 24)
(* Handling of local labels and backpatching *)
type label_definition =
Label_defined of int
| Label_undefined of (int * int) list
let label_table = ref ([| |] : label_definition array)
let extend_label_table needed =
let new_size = ref(Array.length !label_table) in
while needed >= !new_size do new_size := 2 * !new_size done;
let new_table = Array.create !new_size (Label_undefined []) in
Array.blit !label_table 0 new_table 0 (Array.length !label_table);
label_table := new_table
let backpatch (pos, orig) =
let displ = (!out_position - orig) / 4 in
!out_buffer.[pos] <- Char.unsafe_chr displ;
!out_buffer.[pos+1] <- Char.unsafe_chr (displ lsr 8);
!out_buffer.[pos+2] <- Char.unsafe_chr (displ lsr 16);
!out_buffer.[pos+3] <- Char.unsafe_chr (displ lsr 24)
let define_label lbl =
if lbl >= Array.length !label_table then extend_label_table lbl;
match (!label_table).(lbl) with
Label_defined _ ->
fatal_error "Emitcode.define_label"
| Label_undefined patchlist ->
List.iter backpatch patchlist;
(!label_table).(lbl) <- Label_defined !out_position
let out_label_with_orig orig lbl =
if lbl >= Array.length !label_table then extend_label_table lbl;
match (!label_table).(lbl) with
Label_defined def ->
out_int((def - orig) / 4)
| Label_undefined patchlist ->
(!label_table).(lbl) <-
Label_undefined((!out_position, orig) :: patchlist);
out_int 0
let out_label l = out_label_with_orig !out_position l
(* Relocation information *)
let reloc_info = ref ([] : (reloc_info * int) list)
let enter info =
reloc_info := (info, !out_position) :: !reloc_info
let slot_for_literal sc =
enter (Reloc_literal sc);
out_int 0
and slot_for_getglobal id =
enter (Reloc_getglobal id);
out_int 0
and slot_for_setglobal id =
enter (Reloc_setglobal id);
out_int 0
and slot_for_c_prim name =
enter (Reloc_primitive name);
out_int 0
(* Debugging events *)
let events = ref ([] : debug_event list)
let record_event ev =
ev.ev_pos <- !out_position;
events := ev :: !events
(* Initialization *)
let init () =
out_position := 0;
label_table := Array.create 16 (Label_undefined []);
reloc_info := [];
events := []
(* Emission of one instruction *)
let emit_instr = function
Klabel lbl -> define_label lbl
| Kacc n ->
if n < 8 then out(opACC0 + n) else (out opACC; out_int n)
| Kenvacc n ->
if n < 4 then out(opENVACC1 + n) else (out opENVACC; out_int (n+1))
| Kpush ->
out opPUSH
| Kpop n ->
out opPOP; out_int n
| Kassign n ->
out opASSIGN; out_int n
| Kpush_retaddr lbl -> out opPUSH_RETADDR; out_label lbl
| Kapply n ->
if n < 4 then out(opAPPLY1 + n - 1) else (out opAPPLY; out_int n)
| Kappterm(n, sz) ->
if n < 4 then (out(opAPPTERM1 + n - 1); out_int sz)
else (out opAPPTERM; out_int n; out_int sz)
| Kreturn n -> out opRETURN; out_int n
| Krestart -> out opRESTART
| Kgrab n -> out opGRAB; out_int n
| Kclosure(lbl, n) -> out opCLOSURE; out_int n; out_label lbl
| Kclosurerec(lbl, n) -> out opCLOSUREREC; out_int n; out_label lbl
| Kgetglobal q -> out opGETGLOBAL; slot_for_getglobal q
| Ksetglobal q -> out opSETGLOBAL; slot_for_setglobal q
| Kconst sc ->
begin match sc with
Const_base(Const_int i) when i >= immed_min & i <= immed_max ->
if i >= 0 & i <= 3
then out (opCONST0 + i)
else (out opCONSTINT; out_int i)
| Const_base(Const_char c) ->
out opCONSTINT; out_int (Char.code c)
| Const_pointer i ->
if i >= 0 & i <= 3
then out (opCONST0 + i)
else (out opCONSTINT; out_int i)
| Const_block(t, []) ->
if t = 0 then out opATOM0 else (out opATOM; out_int t)
| _ ->
out opGETGLOBAL; slot_for_literal sc
end
| Kmakeblock(n, t) ->
if n = 0 then
if t < 4 then out (opATOM0 + t) else (out opATOM; out_int t)
else if n < 4 then (out(opMAKEBLOCK1 + n - 1); out_int t)
else (out opMAKEBLOCK; out_int n; out_int t)
| Kgetfield n ->
if n < 4 then out(opGETFIELD0 + n) else (out opGETFIELD; out_int n)
| Ksetfield n ->
if n < 4 then out(opSETFIELD0 + n) else (out opSETFIELD; out_int n)
| Kdummy n ->
if n = 0 then out opATOM0 else (out opDUMMY; out_int n)
| Kupdate n -> out opUPDATE
| Kvectlength -> out opVECTLENGTH
| Kgetvectitem -> out opGETVECTITEM
| Ksetvectitem -> out opSETVECTITEM
| Kgetstringchar -> out opGETSTRINGCHAR
| Ksetstringchar -> out opSETSTRINGCHAR
| Kbranch lbl -> out opBRANCH; out_label lbl
| Kbranchif lbl -> out opBRANCHIF; out_label lbl
| Kbranchifnot lbl -> out opBRANCHIFNOT; out_label lbl
| Kstrictbranchif lbl -> out opBRANCHIF; out_label lbl
| Kstrictbranchifnot lbl -> out opBRANCHIFNOT; out_label lbl
| Kswitch(tbl_const, tbl_block) ->
out opSWITCH;
out_int (Array.length tbl_const + (Array.length tbl_block lsl 16));
let org = !out_position in
Array.iter (out_label_with_orig org) tbl_const;
Array.iter (out_label_with_orig org) tbl_block
| Kboolnot -> out opBOOLNOT
| Kpushtrap lbl -> out opPUSHTRAP; out_label lbl
| Kpoptrap -> out opPOPTRAP
| Kraise -> out opRAISE
| Kcheck_signals -> out opCHECK_SIGNALS
| Kccall(name, n) ->
if n <= 5
then (out (opC_CALL1 + n - 1); slot_for_c_prim name)
else (out opC_CALLN; out_int n; slot_for_c_prim name)
| Knegint -> out opNEGINT | Kaddint -> out opADDINT
| Ksubint -> out opSUBINT | Kmulint -> out opMULINT
| Kdivint -> out opDIVINT | Kmodint -> out opMODINT
| Kandint -> out opANDINT | Korint -> out opORINT
| Kxorint -> out opXORINT | Klslint -> out opLSLINT
| Klsrint -> out opLSRINT | Kasrint -> out opASRINT
| Kintcomp Ceq -> out opEQ | Kintcomp Cneq -> out opNEQ
| Kintcomp Clt -> out opLTINT | Kintcomp Cle -> out opLEINT
| Kintcomp Cgt -> out opGTINT | Kintcomp Cge -> out opGEINT
| Koffsetint n -> out opOFFSETINT; out_int n
| Koffsetref n -> out opOFFSETREF; out_int n
| Kgetmethod -> out opGETMETHOD
| Kevent ev -> record_event ev
| Kstop -> out opSTOP
(* Emission of a list of instructions. Include some peephole optimization. *)
let rec emit = function
[] -> ()
(* Peephole optimizations *)
| Kpush :: Kacc n :: c ->
if n < 8 then out(opPUSHACC0 + n) else (out opPUSHACC; out_int n);
emit c
| Kpush :: Kenvacc n :: c ->
if n < 4 then out(opPUSHENVACC1 + n)
else (out opPUSHENVACC; out_int (n+1));
emit c
| Kpush :: Kgetglobal id :: Kgetfield n :: c ->
out opPUSHGETGLOBALFIELD; slot_for_getglobal id; out_int n; emit c
| Kpush :: Kgetglobal q :: c ->
out opPUSHGETGLOBAL; slot_for_getglobal q; emit c
| Kpush :: Kconst sc :: c ->
begin match sc with
Const_base(Const_int i) when i >= immed_min & i <= immed_max ->
if i >= 0 & i <= 3
then out (opPUSHCONST0 + i)
else (out opPUSHCONSTINT; out_int i)
| Const_base(Const_char c) ->
out opPUSHCONSTINT; out_int(Char.code c)
| Const_block(t, []) ->
if t = 0 then out opPUSHATOM0 else (out opPUSHATOM; out_int t)
| _ ->
out opPUSHGETGLOBAL; slot_for_literal sc
end;
emit c
| Kgetglobal id :: Kgetfield n :: c ->
out opGETGLOBALFIELD; slot_for_getglobal id; out_int n; emit c
(* Default case *)
| instr :: c ->
emit_instr instr; emit c
(* Emission to a file *)
let to_file outchan unit_name crc_interface code =
init();
output_string outchan cmo_magic_number;
let pos_depl = pos_out outchan in
output_binary_int outchan 0;
let pos_code = pos_out outchan in
emit code;
output outchan !out_buffer 0 !out_position;
let compunit =
{ cu_name = unit_name;
cu_pos = pos_code;
cu_codesize = !out_position;
cu_reloc = List.rev !reloc_info;
cu_interface = crc_interface;
cu_imports = Env.imported_units();
cu_primitives = !Translmod.primitive_declarations;
cu_force_link = false;
cu_events = !events } in
init(); (* Free out_buffer and reloc_info *)
Types.cleanup_abbrev (); (* Remove any cached abbreviation
expansion before saving *)
let pos_compunit = pos_out outchan in
output_value outchan compunit;
seek_out outchan pos_depl;
output_binary_int outchan pos_compunit
(* Emission to a memory block *)
let to_memory init_code fun_code =
init();
emit init_code;
emit fun_code;
let code = Meta.static_alloc !out_position in
String.unsafe_blit !out_buffer 0 code 0 !out_position;
let reloc = List.rev !reloc_info
and code_size = !out_position in
init();
(code, code_size, reloc)