Project

General

Profile

Statistics
| Branch: | Tag: | Revision:

lustrec / src / machine_code.ml @ a38c681e

History | View | Annotate | Download (21.7 KB)

1

    
2
(* ----------------------------------------------------------------------------
3
 * SchedMCore - A MultiCore Scheduling Framework
4
 * Copyright (C) 2009-2013, ONERA, Toulouse, FRANCE - LIFL, Lille, FRANCE
5
 * Copyright (C) 2012-2013, INPT, Toulouse, FRANCE
6
 *
7
 * This file is part of Prelude
8
 *
9
 * Prelude is free software; you can redistribute it and/or
10
 * modify it under the terms of the GNU Lesser General Public License
11
 * as published by the Free Software Foundation ; either version 2 of
12
 * the License, or (at your option) any later version.
13
 *
14
 * Prelude is distributed in the hope that it will be useful, but
15
 * WITHOUT ANY WARRANTY ; without even the implied warranty of
16
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17
 * Lesser General Public License for more details.
18
 *
19
 * You should have received a copy of the GNU Lesser General Public
20
 * License along with this program ; if not, write to the Free Software
21
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22
 * USA
23
 *---------------------------------------------------------------------------- *)
24

    
25
(* This module is used for the lustre to C compiler *)
26

    
27
open LustreSpec
28
open Corelang
29
open Clocks
30
open Causality
31

    
32
exception NormalizationError
33

    
34
module OrdVarDecl:Map.OrderedType with type t=var_decl =
35
  struct type t = var_decl;; let compare = compare end
36

    
37
module ISet = Set.Make(OrdVarDecl)
38

    
39
type value_t = 
40
  | Cst of constant
41
  | LocalVar of var_decl
42
  | StateVar of var_decl
43
  | Fun of ident * value_t list 
44
  | Array of value_t list
45
  | Access of value_t * value_t
46
  | Power of value_t * value_t
47

    
48
type instr_t =
49
  | MLocalAssign of var_decl * value_t
50
  | MStateAssign of var_decl * value_t
51
  | MReset of ident
52
  | MStep of var_decl list * ident * value_t list
53
  | MBranch of value_t * (label * instr_t list) list
54
 
55
let rec pp_val fmt v =
56
  match v with
57
    | Cst c         -> Printers.pp_const fmt c 
58
    | LocalVar v    -> Format.pp_print_string fmt v.var_id
59
    | StateVar v    -> Format.pp_print_string fmt v.var_id
60
    | Array vl      -> Format.fprintf fmt "[%a]" (Utils.fprintf_list ~sep:", " pp_val)  vl
61
    | Access (t, i) -> Format.fprintf fmt "%a[%a]" pp_val t pp_val i
62
    | Power (v, n)  -> Format.fprintf fmt "(%a^%a)" pp_val v pp_val n
63
    | Fun (n, vl)   -> Format.fprintf fmt "%s (%a)" n (Utils.fprintf_list ~sep:", " pp_val)  vl
64

    
65
let rec pp_instr fmt i =
66
  match i with 
67
    | MLocalAssign (i,v) -> Format.fprintf fmt "%s<-l- %a" i.var_id pp_val v
68
    | MStateAssign (i,v) -> Format.fprintf fmt "%s<-s- %a" i.var_id pp_val v
69
    | MReset i           -> Format.fprintf fmt "reset %s" i
70
    | MStep (il, i, vl)  ->
71
      Format.fprintf fmt "%a = %s (%a)"
72
	(Utils.fprintf_list ~sep:", " (fun fmt v -> Format.pp_print_string fmt v.var_id)) il
73
	i      
74
	(Utils.fprintf_list ~sep:", " pp_val) vl
75
    | MBranch (g,hl)     ->
76
      Format.fprintf fmt "@[<v 2>case(%a) {@,%a@,}@]"
77
	pp_val g
78
	(Utils.fprintf_list ~sep:"@," pp_branch) hl
79

    
80
and pp_branch fmt (t, h) =
81
  Format.fprintf fmt "@[<v 2>%s:@,%a@]" t (Utils.fprintf_list ~sep:"@," pp_instr) h
82

    
83
type step_t = {
84
  step_checks: (Location.t * value_t) list;
85
  step_inputs: var_decl list;
86
  step_outputs: var_decl list;
87
  step_locals: var_decl list;
88
  step_instrs: instr_t list;
89
  step_asserts: value_t list;
90
}
91

    
92
type static_call = top_decl * (Dimension.dim_expr list)
93

    
94
type machine_t = {
95
  mname: node_desc;
96
  mmemory: var_decl list;
97
  mcalls: (ident * static_call) list; (* map from stateful/stateless instance to node, no internals *)
98
  minstances: (ident * static_call) list; (* sub-map of mcalls, from stateful instance to node *)
99
  minit: instr_t list;
100
  mstatic: var_decl list; (* static inputs only *)
101
  mstep: step_t;
102
  mspec: node_annot option;
103
  mannot: expr_annot list;
104
}
105

    
106
let pp_step fmt s =
107
  Format.fprintf fmt "@[<v>inputs : %a@ outputs: %a@ locals : %a@ checks : %a@ instrs : @[%a@]@ asserts : @[%a@]@]@ "
108
    (Utils.fprintf_list ~sep:", " Printers.pp_var) s.step_inputs
109
    (Utils.fprintf_list ~sep:", " Printers.pp_var) s.step_outputs
110
    (Utils.fprintf_list ~sep:", " Printers.pp_var) s.step_locals
111
    (Utils.fprintf_list ~sep:", " (fun fmt (_, c) -> pp_val fmt c)) s.step_checks
112
    (Utils.fprintf_list ~sep:"@ " pp_instr) s.step_instrs
113
    (Utils.fprintf_list ~sep:", " pp_val) s.step_asserts
114

    
115

    
116
let pp_static_call fmt (node, args) =
117
 Format.fprintf fmt "%s<%a>"
118
   (node_name node)
119
   (Utils.fprintf_list ~sep:", " Dimension.pp_dimension) args
120

    
121
let pp_machine fmt m =
122
  Format.fprintf fmt 
123
    "@[<v 2>machine %s@ mem      : %a@ instances: %a@ init     : %a@ step     :@   @[<v 2>%a@]@ @  spec : @[%t@]@  annot : @[%a@]@]@ "
124
    m.mname.node_id
125
    (Utils.fprintf_list ~sep:", " Printers.pp_var) m.mmemory
126
    (Utils.fprintf_list ~sep:", " (fun fmt (o1, o2) -> Format.fprintf fmt "(%s, %a)" o1 pp_static_call o2)) m.minstances
127
    (Utils.fprintf_list ~sep:"@ " pp_instr) m.minit
128
    pp_step m.mstep
129
    (fun fmt -> match m.mspec with | None -> () | Some spec -> Printers.pp_spec fmt spec)
130
    (Utils.fprintf_list ~sep:"@ " Printers.pp_expr_annot) m.mannot
131

    
132
(* Returns the declared stateless status and the computed one. *)
133
let get_stateless_status m =
134
 (m.mname.node_dec_stateless, Utils.desome m.mname.node_stateless)
135

    
136
let is_input m id =
137
  List.exists (fun o -> o.var_id = id.var_id) m.mstep.step_inputs
138

    
139
let is_output m id =
140
  List.exists (fun o -> o.var_id = id.var_id) m.mstep.step_outputs
141

    
142
let is_memory m id =
143
  List.exists (fun o -> o.var_id = id.var_id) m.mmemory
144

    
145
let conditional c t e =
146
  MBranch(c, [ (tag_true, t); (tag_false, e) ])
147

    
148
let dummy_var_decl name typ =
149
  {
150
    var_id = name;
151
    var_dec_type = dummy_type_dec;
152
    var_dec_clock = dummy_clock_dec;
153
    var_dec_const = false;
154
    var_type =  typ;
155
    var_clock = Clocks.new_ck (Clocks.Cvar Clocks.CSet_all) true;
156
    var_loc = Location.dummy_loc
157
  }
158

    
159
let arrow_id = "_arrow"
160

    
161
let arrow_typ = Types.new_ty Types.Tunivar
162

    
163
let arrow_desc =
164
  {
165
    node_id = arrow_id;
166
    node_type = Type_predef.type_bin_poly_op;
167
    node_clock = Clock_predef.ck_bin_univ;
168
    node_inputs= [dummy_var_decl "_in1" arrow_typ; dummy_var_decl "_in2" arrow_typ];
169
    node_outputs= [dummy_var_decl "_out" arrow_typ];
170
    node_locals= [];
171
    node_gencalls = [];
172
    node_checks = [];
173
    node_asserts = [];
174
    node_eqs= [];
175
    node_dec_stateless = false;
176
    node_stateless = Some false;
177
    node_spec = None;
178
    node_annot = [];  }
179

    
180
let arrow_top_decl =
181
  {
182
    top_decl_desc = Node arrow_desc;
183
    top_decl_loc = Location.dummy_loc
184
  }
185

    
186
let arrow_machine =
187
  let state = "_first" in
188
  let var_state = dummy_var_decl state (Types.new_ty Types.Tbool) in
189
  let var_input1 = List.nth arrow_desc.node_inputs 0 in
190
  let var_input2 = List.nth arrow_desc.node_inputs 1 in
191
  let var_output = List.nth arrow_desc.node_outputs 0 in
192
  {
193
    mname = arrow_desc;
194
    mmemory = [var_state];
195
    mcalls = [];
196
    minstances = [];
197
    minit = [MStateAssign(var_state, Cst (const_of_bool true))];
198
    mstatic = [];
199
    mstep = {
200
      step_inputs = arrow_desc.node_inputs;
201
      step_outputs = arrow_desc.node_outputs;
202
      step_locals = [];
203
      step_checks = [];
204
      step_instrs = [conditional (StateVar var_state)
205
			         [MStateAssign(var_state, Cst (const_of_bool false));
206
                                  MLocalAssign(var_output, LocalVar var_input1)]
207
                                 [MLocalAssign(var_output, LocalVar var_input2)] ];
208
      step_asserts = [];
209
    };
210
    mspec = None;
211
    mannot = [];
212
  }
213

    
214
let new_instance =
215
  let cpt = ref (-1) in
216
  fun caller callee tag ->
217
    begin
218
      let o =
219
	if Stateless.check_node callee then
220
	  node_name callee
221
	else
222
	  Printf.sprintf "ni_%d" (incr cpt; !cpt) in
223
      let o =
224
	if !Options.ansi && is_generic_node callee
225
	then Printf.sprintf "%s_inst_%d" o (Utils.position (fun e -> e.expr_tag = tag) caller.node_gencalls)
226
	else o in
227
      o
228
    end
229

    
230
(* translate_<foo> : node -> context -> <foo> -> machine code/expression *)
231
(* the context contains  m : state aka memory variables  *)
232
(*                      si : initialization instructions *)
233
(*                       j : node aka machine instances  *)
234
(*                       d : local variables             *)
235
(*                       s : step instructions           *)
236
let translate_ident node (m, si, j, d, s) id =
237
  try (* id is a node var *)
238
    let var_id = get_node_var id node in
239
    if ISet.exists (fun v -> v.var_id = id) m
240
    then StateVar var_id
241
    else LocalVar var_id
242
  with Not_found -> (* id is a constant *)
243
    LocalVar (Corelang.var_decl_of_const (Hashtbl.find Corelang.consts_table id))
244

    
245
let rec control_on_clock node ((m, si, j, d, s) as args) ck inst =
246
 match (Clocks.repr ck).cdesc with
247
 | Con    (ck1, cr, l) ->
248
   let id  = Clocks.const_of_carrier cr in
249
   control_on_clock node args ck1 (MBranch (translate_ident node args id,
250
					    [l, [inst]] ))
251
 | _                   -> inst
252

    
253
let rec join_branches hl1 hl2 =
254
 match hl1, hl2 with
255
 | []          , _            -> hl2
256
 | _           , []           -> hl1
257
 | (t1, h1)::q1, (t2, h2)::q2 ->
258
   if t1 < t2 then (t1, h1) :: join_branches q1 hl2 else
259
   if t1 > t2 then (t2, h2) :: join_branches hl1 q2
260
   else (t1, List.fold_right join_guards h1 h2) :: join_branches q1 q2
261

    
262
and join_guards inst1 insts2 =
263
 match inst1, insts2 with
264
 | _                   , []                               ->
265
   [inst1]
266
 | MBranch (x1, hl1), MBranch (x2, hl2) :: q when x1 = x2 ->
267
   MBranch (x1, join_branches (sort_handlers hl1) (sort_handlers hl2))
268
   :: q
269
 | _ -> inst1 :: insts2
270

    
271
let join_guards_list insts =
272
 List.fold_right join_guards insts []
273

    
274
(* specialize predefined (polymorphic) operators
275
   wrt their instances, so that the C semantics 
276
   is preserved *)
277
let specialize_to_c expr =
278
 match expr.expr_desc with
279
 | Expr_appl (id, e, r) ->
280
   if List.exists (fun e -> Types.is_bool_type e.expr_type) (expr_list_of_expr e)
281
   then let id =
282
	  match id with
283
	  | "="  -> "equi"
284
	  | "!=" -> "xor"
285
	  | _    -> id in
286
	{ expr with expr_desc = Expr_appl (id, e, r) }
287
   else expr
288
 | _ -> expr
289

    
290
let specialize_op expr =
291
  match !Options.output with
292
  | "C" -> specialize_to_c expr
293
  | _   -> expr
294

    
295
let rec translate_expr node ((m, si, j, d, s) as args) expr =
296
 let expr = specialize_op expr in
297
 match expr.expr_desc with
298
 | Expr_const v                     -> Cst v
299
 | Expr_ident x                     -> translate_ident node args x
300
 | Expr_array el                    -> Array (List.map (translate_expr node args) el)
301
 | Expr_access (t, i)               -> Access (translate_expr node args t, translate_expr node args (expr_of_dimension i))
302
 | Expr_power  (e, n)               -> Power  (translate_expr node args e, translate_expr node args (expr_of_dimension n))
303
 | Expr_tuple _
304
 | Expr_arrow _ 
305
 | Expr_fby _
306
 | Expr_pre _                       -> (Printers.pp_expr Format.err_formatter expr; Format.pp_print_flush Format.err_formatter (); raise NormalizationError)
307
 | Expr_when    (e1, _, _)          -> translate_expr node args e1
308
 | Expr_merge   (x, _)              -> raise NormalizationError
309
 | Expr_appl (id, e, _) when Basic_library.is_internal_fun id ->
310
   let nd = node_from_name id in
311
   Fun (node_name nd, List.map (translate_expr node args) (expr_list_of_expr e))
312
 | Expr_ite (g,t,e) -> (
313
   (* special treatment depending on the active backend. For horn backend, ite
314
      are preserved in expression. While they are removed for C or Java
315
      backends. *)
316
   match !Options.output with | "horn" -> 
317
     Fun ("ite", [translate_expr node args g; translate_expr node args t; translate_expr node args e])
318
   | "C" | "java" | _ -> 
319
     (Printers.pp_expr Format.err_formatter expr; Format.pp_print_flush Format.err_formatter (); raise NormalizationError)
320
 )
321
 | _                   -> raise NormalizationError
322

    
323
let translate_guard node args expr =
324
  match expr.expr_desc with
325
  | Expr_ident x  -> translate_ident node args x
326
  | _ -> (Format.eprintf "internal error: translate_guard %s %a@." node.node_id Printers.pp_expr expr;assert false)
327

    
328
let rec translate_act node ((m, si, j, d, s) as args) (y, expr) =
329
  match expr.expr_desc with
330
  | Expr_ite   (c, t, e) -> let g = translate_guard node args c in
331
			    conditional g [translate_act node args (y, t)]
332
                              [translate_act node args (y, e)]
333
  | Expr_merge (x, hl)   -> MBranch (translate_ident node args x, List.map (fun (t,  h) -> t, [translate_act node args (y, h)]) hl)
334
  | _                    -> MLocalAssign (y, translate_expr node args expr)
335

    
336
let reset_instance node args i r c =
337
  match r with
338
  | None        -> []
339
  | Some (x, l) -> [control_on_clock node args c (MBranch (translate_ident node args x, [l, [MReset i]]))]
340

    
341
let translate_eq node ((m, si, j, d, s) as args) eq =
342
  (*Format.eprintf "translate_eq %a with clock %a@." Printers.pp_node_eq eq Clocks.print_ck eq.eq_rhs.expr_clock;*)
343
  match eq.eq_lhs, eq.eq_rhs.expr_desc with
344
  | [x], Expr_arrow (e1, e2)                     ->
345
    let var_x = get_node_var x node in
346
    let o = new_instance node arrow_top_decl eq.eq_rhs.expr_tag in
347
    let c1 = translate_expr node args e1 in
348
    let c2 = translate_expr node args e2 in
349
    (m,
350
     MReset o :: si,
351
     Utils.IMap.add o (arrow_top_decl, []) j,
352
     d,
353
     (control_on_clock node args eq.eq_rhs.expr_clock (MStep ([var_x], o, [c1;c2]))) :: s)
354
  | [x], Expr_pre e1 when ISet.mem (get_node_var x node) d     ->
355
    let var_x = get_node_var x node in
356
    (ISet.add var_x m,
357
     si,
358
     j,
359
     d,
360
     control_on_clock node args eq.eq_rhs.expr_clock (MStateAssign (var_x, translate_expr node args e1)) :: s)
361
  | [x], Expr_fby (e1, e2) when ISet.mem (get_node_var x node) d ->
362
    let var_x = get_node_var x node in
363
    (ISet.add var_x m,
364
     MStateAssign (var_x, translate_expr node args e1) :: si,
365
     j,
366
     d,
367
     control_on_clock node args eq.eq_rhs.expr_clock (MStateAssign (var_x, translate_expr node args e2)) :: s)
368

    
369
  | p  , Expr_appl (f, arg, r) when not (Basic_library.is_internal_fun f) ->
370
    let var_p = List.map (fun v -> get_node_var v node) p in
371
    let el = expr_list_of_expr arg in
372
    let vl = List.map (translate_expr node args) el in
373
    let node_f = node_from_name f in
374
    let call_f =
375
      node_f,
376
      NodeDep.filter_static_inputs (node_inputs node_f) el in 
377
    let o = new_instance node node_f eq.eq_rhs.expr_tag in
378
    let call_ck = Clocks.new_var true in
379
    Clock_calculus.unify_imported_clock (Some call_ck) eq.eq_rhs.expr_clock;
380
    (m,
381
     (if Stateless.check_node node_f then si else MReset o :: si),
382
     Utils.IMap.add o call_f j,
383
     d,
384
     reset_instance node args o r eq.eq_rhs.expr_clock @
385
       (control_on_clock node args call_ck (MStep (var_p, o, vl))) :: s)
386

    
387
   (* special treatment depending on the active backend. For horn backend, x = ite (g,t,e)
388
      are preserved. While they are replaced as if g then x = t else x = e in  C or Java
389
      backends. *)
390
  | [x], Expr_ite   (c, t, e) 
391
    when (match !Options.output with | "horn" -> true | "C" | "java" | _ -> false)
392
      -> 
393
    let var_x = get_node_var x node in
394
    (m, 
395
     si, 
396
     j, 
397
     d, 
398
     (control_on_clock node args eq.eq_rhs.expr_clock 
399
	(MLocalAssign (var_x, translate_expr node args eq.eq_rhs))::s)
400
    )
401
      
402
  | [x], _                                       -> (
403
    let var_x = get_node_var x node in
404
    (m, si, j, d, 
405
     control_on_clock 
406
       node
407
       args
408
       eq.eq_rhs.expr_clock
409
       (translate_act node args (var_x, eq.eq_rhs)) :: s
410
    )
411
  )
412
  | _                                            ->
413
    begin
414
      Format.eprintf "unsupported equation: %a@?" Printers.pp_node_eq eq;
415
      assert false
416
    end
417

    
418
let find_eq xl eqs =
419
  let rec aux accu eqs =
420
      match eqs with
421
	| [] ->
422
	  begin
423
	    Format.eprintf "Looking for variables %a in the following equations@.%a@."
424
	      (Utils.fprintf_list ~sep:" , " (fun fmt v -> Format.fprintf fmt "%s" v)) xl
425
	      Printers.pp_node_eqs eqs;
426
	    assert false
427
	  end
428
	| hd::tl -> 
429
	  if List.exists (fun x -> List.mem x hd.eq_lhs) xl then hd, accu@tl else aux (hd::accu) tl
430
    in
431
    aux [] eqs
432

    
433
(* Sort the set of equations of node [nd] according 
434
   to the computed schedule [sch]
435
*)
436
let sort_equations_from_schedule nd sch =
437
  let split_eqs = Splitting.tuple_split_eq_list nd.node_eqs in
438
  let eqs_rev, remainder =
439
    List.fold_left 
440
      (fun (accu, node_eqs_remainder) vl -> 
441
       if List.exists (fun eq -> List.exists (fun v -> List.mem v eq.eq_lhs) vl) accu
442
       then
443
	 (accu, node_eqs_remainder)
444
       else
445
	 let eq_v, remainder = find_eq vl node_eqs_remainder in
446
	 eq_v::accu, remainder
447
      ) 
448
      ([], split_eqs) 
449
      sch 
450
  in
451
  if List.length remainder > 0 then (
452
    Format.eprintf "Equations not used are@.%a@.Full equation set is:@.%a@.@?"
453
		   Printers.pp_node_eqs remainder
454
      		   Printers.pp_node_eqs nd.node_eqs;
455
    assert false);
456
  List.rev eqs_rev
457

    
458
let translate_eqs node args eqs =
459
  List.fold_right (fun eq args -> translate_eq node args eq) eqs args;;
460

    
461
let translate_decl nd sch =
462
  (*Log.report ~level:1 (fun fmt -> Printers.pp_node fmt nd);*)
463

    
464
(*
465
  let eqs_rev, remainder = 
466
    List.fold_left 
467
      (fun (accu, node_eqs_remainder) v -> 
468
	  if List.exists (fun eq -> List.mem v eq.eq_lhs) accu
469
	  then
470
	    (accu, node_eqs_remainder)
471
	  else
472
	    (*if   List.exists (fun vdecl -> vdecl.var_id = v) nd.node_locals
473
	      || List.exists (fun vdecl -> vdecl.var_id = v) nd.node_outputs
474
	    then*)
475
	      let eq_v, remainder = find_eq v node_eqs_remainder in
476
	      eq_v::accu, remainder
477
	    (* else it is a constant value, checked during typing phase
478
	    else	 
479
	      accu, node_eqs_remainder *)
480
      ) 
481
      ([], split_eqs) 
482
      sch 
483
  in
484
 *)
485
  let sorted_eqs = sort_equations_from_schedule nd sch in
486

    
487
  let init_args = ISet.empty, [], Utils.IMap.empty, List.fold_right (fun l -> ISet.add l) nd.node_locals ISet.empty, [] in
488
  (* memories, init instructions, node calls, local variables (including memories), step instrs *)
489
  let m, init, j, locals, s = translate_eqs nd init_args sorted_eqs in
490
  let mmap = Utils.IMap.fold (fun i n res -> (i, n)::res) j [] in
491
  {
492
    mname = nd;
493
    mmemory = ISet.elements m;
494
    mcalls = mmap;
495
    minstances = List.filter (fun (_, (n,_)) -> not (Stateless.check_node n)) mmap;
496
    minit = init;
497
    mstatic = List.filter (fun v -> v.var_dec_const) nd.node_inputs;
498
    mstep = {
499
      step_inputs = nd.node_inputs;
500
      step_outputs = nd.node_outputs;
501
      step_locals = ISet.elements (ISet.diff locals m);
502
      step_checks = List.map (fun d -> d.Dimension.dim_loc, translate_expr nd init_args (expr_of_dimension d)) nd.node_checks;
503
      step_instrs = (
504
	(* special treatment depending on the active backend. For horn backend,
505
	   common branches are not merged while they are in C or Java
506
	   backends. *)
507
	match !Options.output with
508
	| "horn" -> s
509
	| "C" | "java" | _ -> join_guards_list s
510
      );
511
      step_asserts = 
512
	let exprl = List.map (fun assert_ -> assert_.assert_expr ) nd.node_asserts in
513
	List.map (translate_expr nd init_args) exprl
514
	;
515
    };
516
    mspec = nd.node_spec;
517
    mannot = nd.node_annot;
518
  }
519

    
520
(** takes the global delcarations and the scheduling associated to each node *)
521
let translate_prog decls node_schs =
522
  let nodes = get_nodes decls in 
523
  List.map 
524
    (fun node -> 
525
      let sch = (Utils.IMap.find node.node_id node_schs).Scheduling.schedule in
526
      translate_decl node sch 
527
    ) nodes
528

    
529
let get_machine_opt name machines =  
530
  List.fold_left 
531
    (fun res m -> 
532
      match res with 
533
      | Some _ -> res 
534
      | None -> if m.mname.node_id = name then Some m else None)
535
    None machines
536
    
537
(* variable substitution for optimizing purposes *)
538

    
539
(* checks whether an [instr] is skip and can be removed from program *)
540
let rec instr_is_skip instr =
541
  match instr with
542
  | MLocalAssign (i, LocalVar v) when i = v -> true
543
  | MStateAssign (i, StateVar v) when i = v -> true
544
  | MBranch (g, hl) -> List.for_all (fun (_, il) -> instrs_are_skip il) hl
545
  | _               -> false
546
and instrs_are_skip instrs =
547
  List.for_all instr_is_skip instrs
548

    
549
let instr_cons instr cont =
550
 if instr_is_skip instr then cont else instr::cont
551

    
552
let rec instr_remove_skip instr cont =
553
  match instr with
554
  | MLocalAssign (i, LocalVar v) when i = v -> cont
555
  | MStateAssign (i, StateVar v) when i = v -> cont
556
  | MBranch (g, hl) -> MBranch (g, List.map (fun (h, il) -> (h, instrs_remove_skip il [])) hl) :: cont
557
  | _               -> instr::cont
558

    
559
and instrs_remove_skip instrs cont =
560
  List.fold_right instr_remove_skip instrs cont
561

    
562
let rec value_replace_var fvar value =
563
  match value with
564
  | Cst c -> value
565
  | LocalVar v -> LocalVar (fvar v)
566
  | StateVar v -> value
567
  | Fun (id, args) -> Fun (id, List.map (value_replace_var fvar) args) 
568
  | Array vl -> Array (List.map (value_replace_var fvar) vl)
569
  | Access (t, i) -> Access(value_replace_var fvar t, i)
570
  | Power (v, n) -> Power(value_replace_var fvar v, n)
571

    
572
let rec instr_replace_var fvar instr cont =
573
  match instr with
574
  | MLocalAssign (i, v) -> instr_cons (MLocalAssign (fvar i, value_replace_var fvar v)) cont
575
  | MStateAssign (i, v) -> instr_cons (MStateAssign (i, value_replace_var fvar v)) cont
576
  | MReset i            -> instr_cons instr cont
577
  | MStep (il, i, vl)   -> instr_cons (MStep (List.map fvar il, i, List.map (value_replace_var fvar) vl)) cont
578
  | MBranch (g, hl)     -> instr_cons (MBranch (value_replace_var fvar g, List.map (fun (h, il) -> (h, instrs_replace_var fvar il [])) hl)) cont
579

    
580
and instrs_replace_var fvar instrs cont =
581
  List.fold_right (instr_replace_var fvar) instrs cont
582

    
583
let step_replace_var fvar step =
584
  { step with
585
    step_checks = List.map (fun (l, v) -> (l, value_replace_var fvar v)) step.step_checks;
586
    step_locals = Utils.remove_duplicates (List.map fvar step.step_locals);
587
    step_instrs = instrs_replace_var fvar step.step_instrs [];
588
}
589

    
590
let rec machine_replace_var fvar m =
591
  { m with
592
    mstep = step_replace_var fvar m.mstep
593
  }
594

    
595
let machine_reuse_var m reuse =
596
  let fvar v =
597
    try
598
      Hashtbl.find reuse v.var_id
599
    with Not_found -> v in
600
  machine_replace_var fvar m
601

    
602
let prog_reuse_var prog node_schs =
603
  List.map 
604
    (fun m -> 
605
      machine_reuse_var m (Utils.IMap.find m.mname.node_id node_schs).Scheduling.reuse_table
606
    ) prog
607

    
608
(* Local Variables: *)
609
(* compile-command:"make -C .." *)
610
(* End: *)