Project

General

Profile

Statistics
| Branch: | Tag: | Revision:

lustrec / src / scheduling.ml @ b84a138e

History | View | Annotate | Download (5.49 KB)

1
(* ----------------------------------------------------------------------------
2
 * SchedMCore - A MultiCore Scheduling Framework
3
 * Copyright (C) 2009-2013, ONERA, Toulouse, FRANCE - LIFL, Lille, FRANCE
4
 * Copyright (C) 2012-2013, INPT, Toulouse, FRANCE
5
 *
6
 * This file is part of Prelude
7
 *
8
 * Prelude is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public License
10
 * as published by the Free Software Foundation ; either version 2 of
11
 * the License, or (at your option) any later version.
12
 *
13
 * Prelude is distributed in the hope that it will be useful, but
14
 * WITHOUT ANY WARRANTY ; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with this program ; if not, write to the Free Software
20
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
21
 * USA
22
 *---------------------------------------------------------------------------- *)
23

    
24
(* This module is used for the lustre to C compiler *)
25

    
26
open Utils
27
open LustreSpec
28
open Corelang
29
open Graph
30
open Causality
31

    
32

    
33
(* Topological sort with a priority for variables belonging in the same equation lhs.
34
   For variables still unrelated, standard compare is used to choose the minimal element.
35
   This priority is used since it helps a lot in factorizing generated code.
36
   In the following functions:
37
   - [eq_equiv] is the equivalence relation between vars of the same equation lhs
38
   - [g] the (imperative) graph to be topologically sorted
39
   - [pending] is the set of unsorted root variables so far, equivalent to the last sorted var
40
   - [frontier] is the set of unsorted root variables so far, not belonging in [pending]
41
   - [sort] is the resulting topological order
42
*)
43
(* Adds successors of [v] in graph [g] in [pending] or [frontier] sets, wrt [eq_equiv],
44
   then removes [v] from [g] 
45
*)
46
let add_successors eq_equiv g v pending frontier =
47
  let succs_v = IdentDepGraph.succ g v in
48
  begin
49
    IdentDepGraph.remove_vertex g v;
50
    List.iter 
51
      (fun v' -> 
52
	if is_graph_root v' g then 
53
	  (if eq_equiv v v' then 
54
	      pending := ISet.add v' !pending 
55
	   else
56
	      frontier := ISet.add v' !frontier)
57
      ) succs_v;
58
  end
59

    
60
(* Chooses the next var to be sorted, taking priority into account.
61
   Modifies [pending] and [frontier] accordingly.
62
*)
63
let next_element eq_equiv g sort pending frontier =
64
  begin
65
    if ISet.is_empty !pending
66
    then
67
      begin
68
	let choice = ISet.min_elt !frontier in
69
      (*Format.eprintf "-1-> %s@." choice;*)
70
	frontier := ISet.remove choice !frontier;
71
	let (p, f) = ISet.partition (eq_equiv choice) !frontier in
72
	pending := p;
73
	frontier := f;
74
	add_successors eq_equiv g choice pending frontier;
75
	if not (ExprDep.is_instance_var choice) then sort := choice :: !sort
76
      end
77
    else
78
      begin
79
	let choice = ISet.min_elt !pending in
80
      (*Format.eprintf "-2-> %s@." choice;*)
81
	pending := ISet.remove choice !pending;
82
	add_successors eq_equiv g choice pending frontier;
83
	if not (ExprDep.is_instance_var choice) then sort := choice :: !sort
84
      end
85
  end
86

    
87

    
88
(* Topological sort of dependency graph [g], with priority.
89
 *)
90
let topological_sort eq_equiv g =
91
  let roots = graph_roots g in
92
  assert (roots <> []);
93
  let frontier = ref (List.fold_right ISet.add roots ISet.empty) in
94
  let pending = ref ISet.empty in
95
  let sorted = ref [] in
96
  begin
97
    while not (ISet.is_empty !frontier && ISet.is_empty !pending)
98
    do
99
      (*Format.eprintf "frontier = {%a}, pending = {%a}@."
100
	(fun fmt -> ISet.iter (fun e -> Format.pp_print_string fmt e)) !frontier
101
	(fun fmt -> ISet.iter (fun e -> Format.pp_print_string fmt e)) !pending;*)
102
      next_element eq_equiv g sorted pending frontier;
103
    done;
104
    IdentDepGraph.clear g;
105
    !sorted
106
  end
107

    
108
let schedule_node n =
109
  try
110
    let eq_equiv = ExprDep.node_eq_equiv n in
111
    let eq_equiv v1 v2 =
112
      try
113
	Hashtbl.find eq_equiv v1 = Hashtbl.find eq_equiv v2
114
      with Not_found -> false in
115
    let n', g = global_dependency n in
116
    Log.report ~level:5 
117
      (fun fmt -> 
118
	Format.eprintf 
119
	  "dependency graph for node %s: %a" 
120
	  n'.node_id
121
	  pp_dep_graph g
122
      );
123
    let gg = IdentDepGraph.copy g in
124
    let sort = topological_sort eq_equiv g in
125

    
126
    let death = Liveness.death_table n gg sort in
127
    Log.report ~level:5 
128
      (fun fmt -> 
129
	Format.eprintf 
130
	  "death table for node %s: %a" 
131
	  n'.node_id
132
	  Liveness.pp_death_table death
133
      );
134

    
135
    let disjoint = Disjunction.clock_disjoint_map (node_vars n) in
136
    
137
    Log.report ~level:5 
138
      (fun fmt -> 
139
	Format.eprintf 
140
	  "clock disjoint map for node %s: %a" 
141
	  n'.node_id
142
	  Disjunction.pp_disjoint_map disjoint
143
      );
144

    
145
    let reuse = Liveness.reuse_policy n sort death in
146
    Log.report ~level:5 
147
      (fun fmt -> 
148
	Format.eprintf 
149
	  "reuse policy for node %s: %a" 
150
	  n'.node_id
151
	  Liveness.pp_reuse_policy reuse
152
      );
153
 
154
    n', sort
155
(* let sorted = TopologicalDepGraph.fold (fun x res -> if ExprDep.is_instance_var x then res else x::res) g []*)
156
  with (Causality.Cycle v) as exc ->
157
    pp_error Format.err_formatter v;
158
    raise exc
159

    
160
let schedule_prog prog =
161
  List.fold_right (
162
    fun top_decl (accu_prog, sch_map)  ->
163
      match top_decl.top_decl_desc with
164
	| Node nd -> 
165
	  let nd', sch = schedule_node nd in
166
	  {top_decl with top_decl_desc = Node nd'}::accu_prog, (nd.node_id, sch)::sch_map
167
	| _ -> top_decl::accu_prog, sch_map
168
    ) 
169
    prog
170
    ([],[])
171

    
172

    
173
(* Local Variables: *)
174
(* compile-command:"make -C .." *)
175
(* End: *)