## lustrec / src / scheduling.ml @ 01c7d5e1

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1 | 22fe1c93 | ploc | (* ---------------------------------------------------------------------------- |
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2 | * SchedMCore - A MultiCore Scheduling Framework |
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3 | * Copyright (C) 2009-2013, ONERA, Toulouse, FRANCE - LIFL, Lille, FRANCE |
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4 | * Copyright (C) 2012-2013, INPT, Toulouse, FRANCE |
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5 | * |
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6 | * This file is part of Prelude |
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7 | * |
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8 | * Prelude is free software; you can redistribute it and/or |
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9 | * modify it under the terms of the GNU Lesser General Public License |
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10 | * as published by the Free Software Foundation ; either version 2 of |
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11 | * the License, or (at your option) any later version. |
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12 | * |
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13 | * Prelude is distributed in the hope that it will be useful, but |
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14 | * WITHOUT ANY WARRANTY ; without even the implied warranty of |
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15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 | * Lesser General Public License for more details. |
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17 | * |
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18 | * You should have received a copy of the GNU Lesser General Public |
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19 | * License along with this program ; if not, write to the Free Software |
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20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
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21 | * USA |
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22 | *---------------------------------------------------------------------------- *) |
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23 | |||

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

26 | open Utils |
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27 | 8ea13d96 | xthirioux | open LustreSpec |

28 | 22fe1c93 | ploc | open Corelang |

29 | open Graph |
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30 | open Causality |
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31 | |||

32 | 3bfed7f9 | xthirioux | type schedule_report = |

33 | { |
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34 | 8a183477 | xthirioux | (* a schedule computed wrt the dependency graph *) |

35 | 3bfed7f9 | xthirioux | schedule : ident list; |

36 | 8a183477 | xthirioux | (* the set of unused variables (no output or mem depends on them) *) |

37 | 3bfed7f9 | xthirioux | unused_vars : ISet.t; |

38 | 8a183477 | xthirioux | (* the table mapping each local var to its in-degree *) |

39 | fanin_table : (ident, int) Hashtbl.t; |
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40 | (* the table mapping each assignment to a set of dead/reusable variables *) |
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41 | 3bfed7f9 | xthirioux | death_table : (ident, ISet.t) Hashtbl.t |

42 | } |
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43 | 22fe1c93 | ploc | |

44 | (* Topological sort with a priority for variables belonging in the same equation lhs. |
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45 | For variables still unrelated, standard compare is used to choose the minimal element. |
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46 | This priority is used since it helps a lot in factorizing generated code. |
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47 | In the following functions: |
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48 | - [eq_equiv] is the equivalence relation between vars of the same equation lhs |
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49 | - [g] the (imperative) graph to be topologically sorted |
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50 | - [pending] is the set of unsorted root variables so far, equivalent to the last sorted var |
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51 | - [frontier] is the set of unsorted root variables so far, not belonging in [pending] |
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52 | - [sort] is the resulting topological order |
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53 | *) |
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54 | (* Adds successors of [v] in graph [g] in [pending] or [frontier] sets, wrt [eq_equiv], |
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55 | then removes [v] from [g] |
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56 | *) |
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57 | let add_successors eq_equiv g v pending frontier = |
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58 | let succs_v = IdentDepGraph.succ g v in |
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59 | begin |
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60 | IdentDepGraph.remove_vertex g v; |
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61 | b84a138e | ploc | List.iter |

62 | (fun v' -> |
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63 | if is_graph_root v' g then |
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64 | (if eq_equiv v v' then |
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65 | pending := ISet.add v' !pending |
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66 | else |
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67 | frontier := ISet.add v' !frontier) |
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68 | ) succs_v; |
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69 | 22fe1c93 | ploc | end |

70 | |||

71 | (* Chooses the next var to be sorted, taking priority into account. |
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72 | Modifies [pending] and [frontier] accordingly. |
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73 | *) |
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74 | let next_element eq_equiv g sort pending frontier = |
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75 | 8ea13d96 | xthirioux | begin |

76 | if ISet.is_empty !pending |
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77 | then |
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78 | begin |
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79 | let choice = ISet.min_elt !frontier in |
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80 | 22fe1c93 | ploc | (*Format.eprintf "-1-> %s@." choice;*) |

81 | 8ea13d96 | xthirioux | frontier := ISet.remove choice !frontier; |

82 | let (p, f) = ISet.partition (eq_equiv choice) !frontier in |
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83 | pending := p; |
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84 | frontier := f; |
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85 | add_successors eq_equiv g choice pending frontier; |
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86 | 3bfed7f9 | xthirioux | if not (ExprDep.is_ghost_var choice) then sort := choice :: !sort |

87 | 8ea13d96 | xthirioux | end |

88 | else |
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89 | begin |
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90 | let choice = ISet.min_elt !pending in |
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91 | 22fe1c93 | ploc | (*Format.eprintf "-2-> %s@." choice;*) |

92 | 8ea13d96 | xthirioux | pending := ISet.remove choice !pending; |

93 | add_successors eq_equiv g choice pending frontier; |
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94 | 3bfed7f9 | xthirioux | if not (ExprDep.is_ghost_var choice) then sort := choice :: !sort |

95 | 8ea13d96 | xthirioux | end |

96 | end |
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97 | |||

98 | 22fe1c93 | ploc | |

99 | (* Topological sort of dependency graph [g], with priority. |
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100 | *) |
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101 | let topological_sort eq_equiv g = |
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102 | let roots = graph_roots g in |
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103 | assert (roots <> []); |
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104 | let frontier = ref (List.fold_right ISet.add roots ISet.empty) in |
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105 | let pending = ref ISet.empty in |
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106 | let sorted = ref [] in |
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107 | begin |
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108 | while not (ISet.is_empty !frontier && ISet.is_empty !pending) |
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109 | do |
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110 | (*Format.eprintf "frontier = {%a}, pending = {%a}@." |
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111 | (fun fmt -> ISet.iter (fun e -> Format.pp_print_string fmt e)) !frontier |
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112 | (fun fmt -> ISet.iter (fun e -> Format.pp_print_string fmt e)) !pending;*) |
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113 | next_element eq_equiv g sorted pending frontier; |
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114 | done; |
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115 | 8ea13d96 | xthirioux | IdentDepGraph.clear g; |

116 | 22fe1c93 | ploc | !sorted |

117 | end |
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118 | |||

119 | 7afcba5a | xthirioux | let schedule_node n = |

120 | 22fe1c93 | ploc | try |

121 | let eq_equiv = ExprDep.node_eq_equiv n in |
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122 | let eq_equiv v1 v2 = |
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123 | try |
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124 | Hashtbl.find eq_equiv v1 = Hashtbl.find eq_equiv v2 |
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125 | with Not_found -> false in |
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126 | cd670fe1 | ploc | |

127 | 22fe1c93 | ploc | let n', g = global_dependency n in |

128 | b84a138e | ploc | Log.report ~level:5 |

129 | (fun fmt -> |
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130 | Format.eprintf |
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131 | "dependency graph for node %s: %a" |
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132 | n'.node_id |
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133 | pp_dep_graph g |
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134 | ); |
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135 | 0e1049dc | xthirioux | |

136 | (* TODO X: extend the graph with inputs (adapt the causality analysis to deal with inputs |
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137 | compute: coi predecessors of outputs |
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138 | warning (no modification) when memories are non used (do not impact output) or when inputs are not used (do not impact output) |
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139 | 8a183477 | xthirioux | DONE ! |

140 | 0e1049dc | xthirioux | *) |

141 | |||

142 | a5784e75 | xthirioux | let gg = IdentDepGraph.copy g in |

143 | d4807c3d | xthirioux | let sort = topological_sort eq_equiv g in |

144 | 3bfed7f9 | xthirioux | let unused = Liveness.compute_unused n gg in |

145 | 8a183477 | xthirioux | let fanin = Liveness.compute_fanin n gg in |

146 | 695d6f2f | xthirioux | let death = Liveness.death_table n gg sort in |

147 | b84a138e | ploc | Log.report ~level:5 |

148 | (fun fmt -> |
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149 | Format.eprintf |
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150 | "death table for node %s: %a" |
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151 | n'.node_id |
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152 | Liveness.pp_death_table death |
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153 | ); |
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154 | 7afcba5a | xthirioux | |

155 | 01c7d5e1 | ploc | let disjoint = Disjunction.clock_disjoint_map (get_node_vars n) in |

156 | b84a138e | ploc | |

157 | Log.report ~level:5 |
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158 | (fun fmt -> |
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159 | Format.eprintf |
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160 | "clock disjoint map for node %s: %a" |
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161 | n'.node_id |
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162 | Disjunction.pp_disjoint_map disjoint |
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163 | ); |
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164 | b1a97ade | xthirioux | |

165 | 695d6f2f | xthirioux | let reuse = Liveness.reuse_policy n sort death in |

166 | b84a138e | ploc | Log.report ~level:5 |

167 | (fun fmt -> |
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168 | Format.eprintf |
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169 | "reuse policy for node %s: %a" |
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170 | n'.node_id |
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171 | Liveness.pp_reuse_policy reuse |
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172 | ); |
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173 | 7afcba5a | xthirioux | |

174 | 8a183477 | xthirioux | n', { schedule = sort; unused_vars = unused; fanin_table = fanin; death_table = death } |

175 | 22fe1c93 | ploc | with (Causality.Cycle v) as exc -> |

176 | pp_error Format.err_formatter v; |
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177 | raise exc |
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178 | |||

179 | 88486aaf | ploc | let schedule_prog prog = |

180 | List.fold_right ( |
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181 | 3bfed7f9 | xthirioux | fun top_decl (accu_prog, sch_map) -> |

182 | 88486aaf | ploc | match top_decl.top_decl_desc with |

183 | | Node nd -> |
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184 | 3bfed7f9 | xthirioux | let nd', report = schedule_node nd in |

185 | 0e1049dc | xthirioux | {top_decl with top_decl_desc = Node nd'}::accu_prog, |

186 | 3bfed7f9 | xthirioux | IMap.add nd.node_id report sch_map |

187 | | _ -> top_decl::accu_prog, sch_map |
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188 | 88486aaf | ploc | ) |

189 | prog |
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190 | 3bfed7f9 | xthirioux | ([],IMap.empty) |

191 | |||

192 | 8a183477 | xthirioux | let pp_schedule fmt node_schs = |

193 | IMap.iter |
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194 | (fun nd report -> |
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195 | Format.fprintf fmt "%s schedule: %a@." |
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196 | nd |
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197 | (fprintf_list ~sep:" ; " (fun fmt v -> Format.fprintf fmt "%s" v)) report.schedule) |
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198 | node_schs |
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199 | |||

200 | let pp_fanin_table fmt node_schs = |
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201 | IMap.iter |
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202 | (fun nd report -> |
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203 | Format.fprintf fmt "%s : %a" nd Liveness.pp_fanin report.fanin_table) |
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204 | node_schs |
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205 | |||

206 | 3bfed7f9 | xthirioux | let pp_warning_unused fmt node_schs = |

207 | IMap.iter |
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208 | (fun nd report -> |
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209 | let unused = report.unused_vars in |
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210 | if not (ISet.is_empty unused) |
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211 | then |
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212 | let nd = match (Corelang.node_from_name nd).top_decl_desc with Node nd -> nd | _ -> assert false in |
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213 | ISet.iter |
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214 | (fun u -> |
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215 | Format.fprintf fmt "Warning: variable '%s' seems unused@.%a@." |
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216 | u |
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217 | 01c7d5e1 | ploc | Location.pp_loc (get_node_var u nd).var_loc) |

218 | 3bfed7f9 | xthirioux | unused |

219 | ) |
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220 | node_schs |
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221 | 22fe1c93 | ploc | |

222 | (* Local Variables: *) |
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223 | (* compile-command:"make -C .." *) |
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224 | (* End: *) |