Project

General

Profile

Statistics
| Branch: | Tag: | Revision:

lustrec / src / normalization.ml @ ef34b4ae

History | View | Annotate | Download (16.3 KB)

1
(********************************************************************)
2
(*                                                                  *)
3
(*  The LustreC compiler toolset   /  The LustreC Development Team  *)
4
(*  Copyright 2012 -    --   ONERA - CNRS - INPT                    *)
5
(*                                                                  *)
6
(*  LustreC is free software, distributed WITHOUT ANY WARRANTY      *)
7
(*  under the terms of the GNU Lesser General Public License        *)
8
(*  version 2.1.                                                    *)
9
(*                                                                  *)
10
(********************************************************************)
11

    
12
open Utils
13
open LustreSpec
14
open Corelang
15
open Format
16

    
17
let expr_true loc ck =
18
{ expr_tag = Utils.new_tag ();
19
  expr_desc = Expr_const (Const_tag tag_true);
20
  expr_type = Type_predef.type_bool;
21
  expr_clock = ck;
22
  expr_delay = Delay.new_var ();
23
  expr_annot = None;
24
  expr_loc = loc }
25

    
26
let expr_false loc ck =
27
{ expr_tag = Utils.new_tag ();
28
  expr_desc = Expr_const (Const_tag tag_false);
29
  expr_type = Type_predef.type_bool;
30
  expr_clock = ck;
31
  expr_delay = Delay.new_var ();
32
  expr_annot = None;
33
  expr_loc = loc }
34

    
35
let expr_once loc ck =
36
 { expr_tag = Utils.new_tag ();
37
  expr_desc = Expr_arrow (expr_true loc ck, expr_false loc ck);
38
  expr_type = Type_predef.type_bool;
39
  expr_clock = ck;
40
  expr_delay = Delay.new_var ();
41
  expr_annot = None;
42
  expr_loc = loc }
43

    
44
let is_expr_once =
45
  let dummy_expr_once = expr_once Location.dummy_loc (Clocks.new_var true) in
46
  fun expr -> Corelang.is_eq_expr expr dummy_expr_once
47

    
48
let unfold_arrow expr =
49
 match expr.expr_desc with
50
 | Expr_arrow (e1, e2) ->
51
    let loc = expr.expr_loc in
52
    let ck = List.hd (Clocks.clock_list_of_clock expr.expr_clock) in
53
    { expr with expr_desc = Expr_ite (expr_once loc ck, e1, e2) }
54
 | _                   -> assert false
55

    
56
let unfold_arrow_active = ref true 
57
let cpt_fresh = ref 0
58

    
59
(* Generate a new local [node] variable *)
60
let mk_fresh_var node loc ty ck =
61
  let vars = get_node_vars node in
62
  let rec aux () =
63
  incr cpt_fresh;
64
  let s = Printf.sprintf "__%s_%d" node.node_id !cpt_fresh in
65
  if List.exists (fun v -> v.var_id = s) vars then aux () else
66
  {
67
    var_id = s;
68
    var_dec_type = dummy_type_dec;
69
    var_dec_clock = dummy_clock_dec;
70
    var_dec_const = false;
71
    var_type = ty;
72
    var_clock = ck;
73
    var_loc = loc
74
  }
75
  in aux ()
76

    
77
(* Generate a new ident expression from a declared variable *)
78
let mk_ident_expr v =
79
  { expr_tag = new_tag ();
80
    expr_desc = Expr_ident v.var_id;
81
    expr_type = v.var_type;
82
    expr_clock = v.var_clock;
83
    expr_delay = Delay.new_var ();
84
    expr_annot = None;
85
    expr_loc = v.var_loc }
86

    
87
(* Get the equation in [defs] with [expr] as rhs, if any *)
88
let get_expr_alias defs expr =
89
 try Some (List.find (fun eq -> is_eq_expr eq.eq_rhs expr) defs)
90
 with
91
   Not_found -> None
92

    
93
(* Replace [expr] with (tuple of) [locals] *)
94
let replace_expr locals expr =
95
 match locals with
96
 | []  -> assert false
97
 | [v] -> { expr with
98
   expr_tag = Utils.new_tag ();
99
   expr_desc = Expr_ident v.var_id }
100
 | _   -> { expr with
101
   expr_tag = Utils.new_tag ();
102
   expr_desc = Expr_tuple (List.map mk_ident_expr locals) }
103

    
104
let unfold_offsets e offsets =
105
  let add_offset e d =
106
(*Format.eprintf "add_offset %a %a@." Dimension.pp_dimension (Types.array_type_dimension e.expr_type) Dimension.pp_dimension d;*)
107
    { e with
108
      expr_tag = Utils.new_tag ();
109
      expr_loc = d.Dimension.dim_loc;
110
      expr_type = Types.array_element_type e.expr_type;
111
      expr_desc = Expr_access (e, d) } in
112
 List.fold_left add_offset e offsets
113

    
114
(* Create an alias for [expr], if none exists yet *)
115
let mk_expr_alias node (defs, vars) expr =
116
(*Format.eprintf "mk_expr_alias %a %a %a@." Printers.pp_expr expr Types.print_ty expr.expr_type Clocks.print_ck expr.expr_clock;*)
117
  match get_expr_alias defs expr with
118
  | Some eq ->
119
    let aliases = List.map (fun id -> List.find (fun v -> v.var_id = id) vars) eq.eq_lhs in
120
    (defs, vars), replace_expr aliases expr
121
  | None    ->
122
    let new_aliases =
123
      List.map2
124
	(mk_fresh_var node expr.expr_loc)
125
	(Types.type_list_of_type expr.expr_type)
126
	(Clocks.clock_list_of_clock expr.expr_clock) in
127
    let new_def =
128
      mkeq expr.expr_loc (List.map (fun v -> v.var_id) new_aliases, expr)
129
    in (new_def::defs, new_aliases@vars), replace_expr new_aliases expr
130

    
131
(* Create an alias for [expr], if [expr] is not already an alias (i.e. an ident)
132
   and [opt] is true *)
133
let mk_expr_alias_opt opt node defvars expr =
134
  match expr.expr_desc with
135
  | Expr_ident alias ->
136
    defvars, expr
137
  | _                -> 
138
    if opt
139
    then
140
      mk_expr_alias node defvars expr
141
    else
142
      defvars, expr
143

    
144
(* Create a (normalized) expression from [ref_e], 
145
   replacing description with [norm_d],
146
   taking propagated [offsets] into account 
147
   in order to change expression type *)
148
let mk_norm_expr offsets ref_e norm_d =
149
  let drop_array_type ty =
150
    Types.map_tuple_type Types.array_element_type ty in
151
  { ref_e with
152
    expr_desc = norm_d;
153
    expr_type = Utils.repeat (List.length offsets) drop_array_type ref_e.expr_type }
154

    
155
(* normalize_<foo> : defs * used vars -> <foo> -> (updated defs * updated vars) * normalized <foo> *)
156
let rec normalize_list alias node offsets norm_element defvars elist =
157
  List.fold_right
158
    (fun t (defvars, qlist) ->
159
      let defvars, norm_t = norm_element alias node offsets defvars t in
160
      (defvars, norm_t :: qlist)
161
    ) elist (defvars, [])
162

    
163
let rec normalize_expr ?(alias=true) node offsets defvars expr =
164
(*  Format.eprintf "normalize %B %a [%a]@." alias Printers.pp_expr expr (Utils.fprintf_list ~sep:"," Dimension.pp_dimension) offsets;*)
165
  match expr.expr_desc with
166
  | Expr_const _ 
167
  | Expr_ident _ -> defvars, unfold_offsets expr offsets
168
  | Expr_array elist ->
169
    let defvars, norm_elist = normalize_list alias node offsets (fun _ -> normalize_array_expr ~alias:true) defvars elist in
170
    let norm_expr = mk_norm_expr offsets expr (Expr_array norm_elist) in
171
    mk_expr_alias_opt alias node defvars norm_expr
172
  | Expr_power (e1, d) when offsets = [] ->
173
    let defvars, norm_e1 = normalize_expr node offsets defvars e1 in
174
    let norm_expr = mk_norm_expr offsets expr (Expr_power (norm_e1, d)) in
175
    mk_expr_alias_opt alias node defvars norm_expr
176
  | Expr_power (e1, d) ->
177
    normalize_expr ~alias:alias node (List.tl offsets) defvars e1
178
  | Expr_access (e1, d) ->
179
    normalize_expr ~alias:alias node (d::offsets) defvars e1
180
  | Expr_tuple elist -> 
181
    let defvars, norm_elist =
182
      normalize_list alias node offsets (fun alias -> normalize_expr ~alias:alias) defvars elist in
183
    defvars, mk_norm_expr offsets expr (Expr_tuple norm_elist)
184
  | Expr_appl (id, args, None) 
185
      when Basic_library.is_internal_fun id 
186
	&& Types.is_array_type expr.expr_type ->
187
    let defvars, norm_args = 
188
      normalize_list 
189
	alias
190
	node
191
	offsets 
192
	(fun _ -> normalize_array_expr ~alias:true) 
193
	defvars 
194
	(expr_list_of_expr args) 
195
    in
196
    defvars, mk_norm_expr offsets expr (Expr_appl (id, expr_of_expr_list args.expr_loc norm_args, None))
197
  | Expr_appl (id, args, None) when Basic_library.is_internal_fun id ->
198
    let defvars, norm_args = normalize_expr ~alias:true node offsets defvars args in
199
    defvars, mk_norm_expr offsets expr (Expr_appl (id, norm_args, None))
200
  | Expr_appl (id, args, r) ->
201
    let defvars, norm_args = normalize_expr node [] defvars args in
202
    let norm_expr = mk_norm_expr [] expr (Expr_appl (id, norm_args, r)) in
203
    if offsets <> []
204
    then
205
      let defvars, norm_expr = normalize_expr node [] defvars norm_expr in
206
      normalize_expr ~alias:alias node offsets defvars norm_expr
207
    else
208
      mk_expr_alias_opt (alias && not (Basic_library.is_internal_fun id)) node defvars norm_expr
209
  | Expr_arrow (e1,e2) when !unfold_arrow_active && not (is_expr_once expr) -> (* Here we differ from Colaco paper: arrows are pushed to the top *)
210
    normalize_expr ~alias:alias node offsets defvars (unfold_arrow expr)
211
  | Expr_arrow (e1,e2) ->
212
    let defvars, norm_e1 = normalize_expr node offsets defvars e1 in
213
    let defvars, norm_e2 = normalize_expr node offsets defvars e2 in
214
    let norm_expr = mk_norm_expr offsets expr (Expr_arrow (norm_e1, norm_e2)) in
215
    mk_expr_alias_opt alias node defvars norm_expr
216
  | Expr_pre e ->
217
    let defvars, norm_e = normalize_expr node offsets defvars e in
218
    let norm_expr = mk_norm_expr offsets expr (Expr_pre norm_e) in
219
    mk_expr_alias_opt alias node defvars norm_expr
220
  | Expr_fby (e1, e2) ->
221
    let defvars, norm_e1 = normalize_expr node offsets defvars e1 in
222
    let defvars, norm_e2 = normalize_expr node offsets defvars e2 in
223
    let norm_expr = mk_norm_expr offsets expr (Expr_fby (norm_e1, norm_e2)) in
224
    mk_expr_alias_opt alias node defvars norm_expr
225
  | Expr_when (e, c, l) ->
226
    let defvars, norm_e = normalize_expr node offsets defvars e in
227
    defvars, mk_norm_expr offsets expr (Expr_when (norm_e, c, l))
228
  | Expr_ite (c, t, e) ->
229
    let defvars, norm_c = normalize_guard node defvars c in
230
    let defvars, norm_t = normalize_cond_expr  node offsets defvars t in
231
    let defvars, norm_e = normalize_cond_expr  node offsets defvars e in
232
    let norm_expr = mk_norm_expr offsets expr (Expr_ite (norm_c, norm_t, norm_e)) in
233
    mk_expr_alias_opt alias node defvars norm_expr
234
  | Expr_merge (c, hl) ->
235
    let defvars, norm_hl = normalize_branches node offsets defvars hl in
236
    let norm_expr = mk_norm_expr offsets expr (Expr_merge (c, norm_hl)) in
237
    mk_expr_alias_opt alias node defvars norm_expr
238
  
239
(* Creates a conditional with a merge construct, which is more lazy *)
240
(*
241
let norm_conditional_as_merge alias node norm_expr offsets defvars expr =
242
 match expr.expr_desc with
243
 | Expr_ite (c, t, e) ->
244
   let defvars, norm_t = norm_expr (alias node offsets defvars t in
245
 | _ -> assert false
246
*)
247
and normalize_branches node offsets defvars hl =
248
 List.fold_right
249
   (fun (t, h) (defvars, norm_q) ->
250
     let (defvars, norm_h) = normalize_cond_expr node offsets defvars h in
251
     defvars, (t, norm_h) :: norm_q
252
   )
253
   hl (defvars, [])
254

    
255
and normalize_array_expr ?(alias=true) node offsets defvars expr =
256
(*  Format.eprintf "normalize_array %B %a [%a]@." alias Printers.pp_expr expr (Utils.fprintf_list ~sep:"," Dimension.pp_dimension) offsets;*)
257
  match expr.expr_desc with
258
  | Expr_power (e1, d) when offsets = [] ->
259
    let defvars, norm_e1 = normalize_expr node offsets defvars e1 in
260
    defvars, mk_norm_expr offsets expr (Expr_power (norm_e1, d))
261
  | Expr_power (e1, d) ->
262
    normalize_array_expr ~alias:alias node (List.tl offsets) defvars e1
263
  | Expr_access (e1, d) -> normalize_array_expr ~alias:alias node (d::offsets) defvars e1
264
  | Expr_array elist when offsets = [] ->
265
    let defvars, norm_elist = normalize_list alias node offsets (fun _ -> normalize_array_expr ~alias:true) defvars elist in
266
    defvars, mk_norm_expr offsets expr (Expr_array norm_elist)
267
  | Expr_appl (id, args, None) when Basic_library.is_internal_fun id ->
268
    let defvars, norm_args = normalize_list alias node offsets (fun _ -> normalize_array_expr ~alias:true) defvars (expr_list_of_expr args) in
269
    defvars, mk_norm_expr offsets expr (Expr_appl (id, expr_of_expr_list args.expr_loc norm_args, None))
270
  |  _ -> normalize_expr ~alias:alias node offsets defvars expr
271

    
272
and normalize_cond_expr ?(alias=true) node offsets defvars expr =
273
  (*Format.eprintf "normalize_cond %B %a [%a]@." alias Printers.pp_expr expr (Utils.fprintf_list ~sep:"," Dimension.pp_dimension) offsets;*)
274
  match expr.expr_desc with
275
  | Expr_access (e1, d) ->
276
    normalize_cond_expr ~alias:alias node (d::offsets) defvars e1
277
  | Expr_ite (c, t, e) ->
278
    let defvars, norm_c = normalize_guard node defvars c in
279
    let defvars, norm_t = normalize_cond_expr node offsets defvars t in
280
    let defvars, norm_e = normalize_cond_expr node offsets defvars e in
281
    defvars, mk_norm_expr offsets expr (Expr_ite (norm_c, norm_t, norm_e))
282
  | Expr_merge (c, hl) ->
283
    let defvars, norm_hl = normalize_branches node offsets defvars hl in
284
    defvars, mk_norm_expr offsets expr (Expr_merge (c, norm_hl))
285
  | _ -> normalize_expr ~alias:alias node offsets defvars expr
286

    
287
and normalize_guard node defvars expr =
288
  let defvars, norm_expr = normalize_expr node [] defvars expr in
289
  mk_expr_alias_opt true node defvars norm_expr
290

    
291
(* outputs cannot be memories as well. If so, introduce new local variable.
292
*)
293
let decouple_outputs node defvars eq =
294
  let rec fold_lhs defvars lhs tys cks =
295
   match lhs, tys, cks with
296
   | [], [], []          -> defvars, []
297
   | v::qv, t::qt, c::qc -> let (defs_q, vars_q), lhs_q = fold_lhs defvars qv qt qc in
298
			    if List.exists (fun o -> o.var_id = v) node.node_outputs
299
			    then
300
			      let newvar = mk_fresh_var node eq.eq_loc t c in
301
			      let neweq  = mkeq eq.eq_loc ([v], mk_ident_expr newvar) in
302
			      (neweq :: defs_q, newvar :: vars_q), newvar.var_id :: lhs_q
303
			    else
304
			      (defs_q, vars_q), v::lhs_q
305
   | _                   -> assert false in
306
  let defvars', lhs' =
307
    fold_lhs
308
      defvars
309
      eq.eq_lhs
310
      (Types.type_list_of_type eq.eq_rhs.expr_type)
311
      (Clocks.clock_list_of_clock eq.eq_rhs.expr_clock) in
312
  defvars', {eq with eq_lhs = lhs' }
313

    
314
let rec normalize_eq node defvars eq = 
315
  match eq.eq_rhs.expr_desc with
316
  | Expr_pre _
317
  | Expr_fby _  ->
318
    let (defvars', eq') = decouple_outputs node defvars eq in
319
    let (defs', vars'), norm_rhs = normalize_expr ~alias:false node [] defvars' eq'.eq_rhs in
320
    let norm_eq = { eq' with eq_rhs = norm_rhs } in
321
    (norm_eq::defs', vars')
322
  | Expr_array _ ->
323
    let (defs', vars'), norm_rhs = normalize_array_expr ~alias:false node [] defvars eq.eq_rhs in
324
    let norm_eq = { eq with eq_rhs = norm_rhs } in
325
    (norm_eq::defs', vars')
326
  | Expr_appl (id, _, None) when Basic_library.is_internal_fun id && Types.is_array_type eq.eq_rhs.expr_type ->
327
    let (defs', vars'), norm_rhs = normalize_array_expr ~alias:false node [] defvars eq.eq_rhs in
328
    let norm_eq = { eq with eq_rhs = norm_rhs } in
329
    (norm_eq::defs', vars')
330
  | Expr_appl _ ->
331
    let (defs', vars'), norm_rhs = normalize_expr ~alias:false node [] defvars eq.eq_rhs in
332
    let norm_eq = { eq with eq_rhs = norm_rhs } in
333
    (norm_eq::defs', vars')
334
  | _ ->
335
    let (defs', vars'), norm_rhs = normalize_cond_expr ~alias:false node [] defvars eq.eq_rhs in
336
    let norm_eq = { eq with eq_rhs = norm_rhs } in
337
    norm_eq::defs', vars'
338

    
339
(** normalize_node node returns a normalized node, 
340
    ie. 
341
    - updated locals
342
    - new equations
343
    - 
344
*)
345
let normalize_node node = 
346
  cpt_fresh := 0;
347
  let inputs_outputs = node.node_inputs@node.node_outputs in
348
  let is_local v =
349
    List.for_all ((!=) v) inputs_outputs in
350
  let orig_vars = inputs_outputs@node.node_locals in
351
  let defs, vars = 
352
    List.fold_left (normalize_eq node) ([], orig_vars) node.node_eqs in
353
  (* Normalize the asserts *)
354
  let vars, assert_defs, asserts = 
355
    List.fold_left (
356
    fun (vars, def_accu, assert_accu) assert_ ->
357
      let assert_expr = assert_.assert_expr in
358
      let (defs, vars'), expr = 
359
	normalize_expr 
360
	  ~alias:false 
361
	  node 
362
	  [] (* empty offset for arrays *)
363
	  ([], vars) (* defvar only contains vars *)
364
	  assert_expr
365
      in
366
      vars', defs@def_accu, {assert_ with assert_expr = expr}::assert_accu
367
    ) (vars, [], []) node.node_asserts in
368
  let new_locals = List.filter is_local vars in
369
  (* Compute traceability info: 
370
     - gather newly bound variables
371
     - compute the associated expression without aliases     
372
  *)
373
  let diff_vars = List.filter (fun v -> not (List.mem v node.node_locals) ) new_locals in
374
  let norm_traceability = {
375
    annots =
376
      List.map 
377
	(fun v -> 
378
	  let expr = substitute_expr diff_vars defs (
379
	    let eq = try
380
		       List.find (fun eq -> eq.eq_lhs = [v.var_id]) defs 
381
	      with Not_found -> (Format.eprintf "var not found %s@." v.var_id; assert false) in
382
	    eq.eq_rhs) in 
383
	  let pair = mkeexpr expr.expr_loc (mkexpr expr.expr_loc (Expr_tuple [expr_of_ident v.var_id expr.expr_loc; expr])) in 
384
	  ["horn_backend";"trace"], pair 
385
	)
386
    diff_vars ;
387
    annot_loc = Location.dummy_loc
388
  }
389

    
390
  in
391
  let node =
392
  { node with 
393
    node_locals = new_locals; 
394
    node_eqs = defs @ assert_defs;
395
    node_asserts = asserts;
396
    node_annot = norm_traceability::node.node_annot;
397
  }
398
  in ((*Printers.pp_node Format.err_formatter node;*) node)
399

    
400
let normalize_decl decl =
401
  match decl.top_decl_desc with
402
  | Node nd ->
403
    {decl with top_decl_desc = Node (normalize_node nd)}
404
  | Open _ | ImportedNode _ | Const _ | TypeDef _ -> decl
405
  
406
let normalize_prog decls = 
407
  List.map normalize_decl decls
408

    
409
(* Local Variables: *)
410
(* compile-command:"make -C .." *)
411
(* End: *)