## lustrec / src / causality.ml @ c82ea2ca

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1 | a2d97a3e | ploc | (********************************************************************) |
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2 | (* *) |
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3 | (* The LustreC compiler toolset / The LustreC Development Team *) |
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4 | (* Copyright 2012 - -- ONERA - CNRS - INPT - LIFL *) |
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5 | (* *) |
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6 | (* LustreC is free software, distributed WITHOUT ANY WARRANTY *) |
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7 | (* under the terms of the GNU Lesser General Public License *) |
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8 | (* version 2.1. *) |
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9 | (* *) |
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10 | (* This file was originally from the Prelude compiler *) |
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11 | (* *) |
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12 | (********************************************************************) |
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13 | 22fe1c93 | ploc | |

14 | |||

15 | (** Simple modular syntactic causality analysis. Can reject correct |
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16 | programs, especially if the program is not flattened first. *) |
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17 | open Utils |
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18 | open LustreSpec |
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19 | open Corelang |
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20 | open Graph |
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21 | open Format |
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22 | |||

23 | eb837d74 | xthirioux | type error = |

24 | | DataCycle of ident list |
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25 | | NodeCycle of ident list |
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26 | |||

27 | exception Error of error |
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28 | 22fe1c93 | ploc | |

29 | |||

30 | eb837d74 | xthirioux | module IdentDepGraph = Graph.Imperative.Digraph.ConcreteBidirectional (IdentModule) |

31 | (*module DotGraph = Graphviz.Dot (IdentDepGraph)*) |
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32 | module Bfs = Traverse.Bfs (IdentDepGraph) |
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33 | |||

34 | 22fe1c93 | ploc | (* Dependency of mem variables on mem variables is cut off |

35 | by duplication of some mem vars into local node vars. |
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36 | Thus, cylic dependency errors may only arise between no-mem vars. |
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37 | 3bfed7f9 | xthirioux | non-mem variables are: |

38 | ec433d69 | xthirioux | - constants/inputs: not needed for causality/scheduling, needed only for detecting useless vars |

39 | 3bfed7f9 | xthirioux | - read mems (fake vars): same remark as above. |

40 | - outputs: decoupled from mems, if necessary |
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41 | - locals |
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42 | - instance vars (fake vars): simplify causality analysis |
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43 | |||

44 | global constants are not part of the dependency graph. |
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45 | |||

46 | 22fe1c93 | ploc | no_mem' = combinational(no_mem, mem); |

47 | => (mem -> no_mem' -> no_mem) |
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48 | |||

49 | mem' = pre(no_mem, mem); |
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50 | => (mem' -> no_mem), (mem -> mem') |
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51 | |||

52 | Global roadmap: |
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53 | - compute two dep graphs g (non-mem/non-mem&mem) and g' (mem/mem) |
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54 | - check cycles in g (a cycle means a dependency error) |
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55 | - break cycles in g' (it's legal !): |
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56 | - check cycles in g' |
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57 | - if any, introduce aux var to break cycle, then start afresh |
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58 | - insert g' into g |
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59 | - return g |
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60 | *) |
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61 | |||

62 | 695d6f2f | xthirioux | (* Tests whether [v] is a root of graph [g], i.e. a source *) |

63 | let is_graph_root v g = |
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64 | IdentDepGraph.in_degree g v = 0 |
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65 | |||

66 | (* Computes the set of graph roots, i.e. the sources of acyclic graph [g] *) |
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67 | let graph_roots g = |
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68 | IdentDepGraph.fold_vertex |
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69 | (fun v roots -> if is_graph_root v g then v::roots else roots) |
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70 | g [] |
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71 | |||

72 | 22fe1c93 | ploc | let add_edges src tgt g = |

73 | (*List.iter (fun s -> List.iter (fun t -> Format.eprintf "add %s -> %s@." s t) tgt) src;*) |
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74 | List.iter |
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75 | (fun s -> |
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76 | List.iter |
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77 | (fun t -> IdentDepGraph.add_edge g s t) |
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78 | tgt) |
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79 | src; |
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80 | g |
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81 | |||

82 | let add_vertices vtc g = |
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83 | (*List.iter (fun t -> Format.eprintf "add %s@." t) vtc;*) |
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84 | List.iter (fun v -> IdentDepGraph.add_vertex g v) vtc; |
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85 | g |
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86 | |||

87 | let new_graph () = |
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88 | IdentDepGraph.create () |
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89 | |||

90 | module ExprDep = struct |
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91 | |||

92 | let instance_var_cpt = ref 0 |
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93 | |||

94 | 3bfed7f9 | xthirioux | (* read vars represent input/mem read-only vars, |

95 | they are not part of the program/schedule, |
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96 | as they are not assigned, |
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97 | but used to compute useless inputs/mems. |
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98 | a mem read var represents a mem at the beginning of a cycle *) |
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99 | let mk_read_var id = |
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100 | sprintf "#%s" id |
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101 | |||

102 | (* instance vars represent node instance calls, |
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103 | they are not part of the program/schedule, |
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104 | but used to simplify causality analysis |
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105 | *) |
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106 | 22fe1c93 | ploc | let mk_instance_var id = |

107 | incr instance_var_cpt; sprintf "!%s_%d" id !instance_var_cpt |
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108 | |||

109 | 3bfed7f9 | xthirioux | let is_read_var v = v.[0] = '#' |

110 | 22fe1c93 | ploc | |

111 | let is_instance_var v = v.[0] = '!' |
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112 | |||

113 | 3bfed7f9 | xthirioux | let is_ghost_var v = is_instance_var v || is_read_var v |

114 | |||

115 | let undo_read_var id = |
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116 | assert (is_read_var id); |
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117 | String.sub id 1 (String.length id - 1) |
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118 | 22fe1c93 | ploc | |

119 | 54d032f5 | xthirioux | let undo_instance_var id = |

120 | assert (is_instance_var id); |
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121 | String.sub id 1 (String.length id - 1) |
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122 | |||

123 | 22fe1c93 | ploc | let eq_memory_variables mems eq = |

124 | let rec match_mem lhs rhs mems = |
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125 | match rhs.expr_desc with |
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126 | | Expr_fby _ |
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127 | | Expr_pre _ -> List.fold_right ISet.add lhs mems |
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128 | 1b01da98 | ploc | | Expr_tuple tl -> |

129 | let lhs' = (transpose_list [lhs]) in |
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130 | List.fold_right2 match_mem lhs' tl mems |
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131 | 22fe1c93 | ploc | | _ -> mems in |

132 | match_mem eq.eq_lhs eq.eq_rhs mems |
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133 | |||

134 | let node_memory_variables nd = |
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135 | b08ffca7 | xthirioux | List.fold_left eq_memory_variables ISet.empty (get_node_eqs nd) |

136 | 22fe1c93 | ploc | |

137 | 3bfed7f9 | xthirioux | let node_input_variables nd = |

138 | List.fold_left (fun inputs v -> ISet.add v.var_id inputs) ISet.empty nd.node_inputs |
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139 | 8a183477 | xthirioux | |

140 | let node_local_variables nd = |
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141 | List.fold_left (fun locals v -> ISet.add v.var_id locals) ISet.empty nd.node_locals |
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142 | 3bfed7f9 | xthirioux | |

143 | ec433d69 | xthirioux | let node_constant_variables nd = |

144 | List.fold_left (fun locals v -> if v.var_dec_const then ISet.add v.var_id locals else locals) ISet.empty nd.node_locals |
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145 | |||

146 | 3bfed7f9 | xthirioux | let node_output_variables nd = |

147 | List.fold_left (fun outputs v -> ISet.add v.var_id outputs) ISet.empty nd.node_outputs |
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148 | |||

149 | bb2ca5f4 | xthirioux | let node_auxiliary_variables nd = |

150 | ISet.diff (node_local_variables nd) (node_memory_variables nd) |
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151 | |||

152 | 3bfed7f9 | xthirioux | let node_variables nd = |

153 | let inputs = node_input_variables nd in |
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154 | let inoutputs = List.fold_left (fun inoutputs v -> ISet.add v.var_id inoutputs) inputs nd.node_outputs in |
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155 | List.fold_left (fun vars v -> ISet.add v.var_id vars) inoutputs nd.node_locals |
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156 | d4807c3d | xthirioux | |

157 | 22fe1c93 | ploc | (* computes the equivalence relation relating variables |

158 | in the same equation lhs, under the form of a table |
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159 | of class representatives *) |
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160 | let node_eq_equiv nd = |
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161 | let eq_equiv = Hashtbl.create 23 in |
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162 | List.iter (fun eq -> |
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163 | let first = List.hd eq.eq_lhs in |
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164 | List.iter (fun v -> Hashtbl.add eq_equiv v first) eq.eq_lhs |
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165 | ) |
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166 | b08ffca7 | xthirioux | (get_node_eqs nd); |

167 | 22fe1c93 | ploc | eq_equiv |

168 | |||

169 | (* Create a tuple of right dimension, according to [expr] type, *) |
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170 | (* filled with variable [v] *) |
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171 | let adjust_tuple v expr = |
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172 | match expr.expr_type.Types.tdesc with |
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173 | | Types.Ttuple tl -> duplicate v (List.length tl) |
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174 | | _ -> [v] |
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175 | |||

176 | d4807c3d | xthirioux | |

177 | 22fe1c93 | ploc | (* Add dependencies from lhs to rhs in [g, g'], *) |

178 | (* no-mem/no-mem and mem/no-mem in g *) |
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179 | (* mem/mem in g' *) |
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180 | 3bfed7f9 | xthirioux | (* match (lhs_is_mem, ISet.mem x mems) with |

181 | | (false, true ) -> (add_edges [x] lhs g, |
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182 | g') |
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183 | | (false, false) -> (add_edges lhs [x] g, |
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184 | g') |
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185 | | (true , false) -> (add_edges lhs [x] g, |
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186 | g') |
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187 | | (true , true ) -> (g, |
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188 | add_edges [x] lhs g') |
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189 | *) |
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190 | let add_eq_dependencies mems inputs node_vars eq (g, g') = |
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191 | d4807c3d | xthirioux | let add_var lhs_is_mem lhs x (g, g') = |

192 | 3bfed7f9 | xthirioux | if is_instance_var x || ISet.mem x node_vars then |

193 | if ISet.mem x mems |
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194 | then |
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195 | let g = add_edges lhs [mk_read_var x] g in |
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196 | if lhs_is_mem |
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197 | then |
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198 | (g, add_edges [x] lhs g') |
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199 | else |
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200 | (add_edges [x] lhs g, g') |
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201 | else |
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202 | let x = if ISet.mem x inputs then mk_read_var x else x in |
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203 | (add_edges lhs [x] g, g') |
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204 | c9043042 | ploc | else (add_edges lhs [mk_read_var x] g, g') (* x is a global constant, treated as a read var *) |

205 | in |
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206 | (* Add dependencies from [lhs] to rhs clock [ck]. *) |
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207 | d4807c3d | xthirioux | let rec add_clock lhs_is_mem lhs ck g = |

208 | (*Format.eprintf "add_clock %a@." Clocks.print_ck ck;*) |
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209 | match (Clocks.repr ck).Clocks.cdesc with |
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210 | | Clocks.Con (ck', cr, _) -> add_var lhs_is_mem lhs (Clocks.const_of_carrier cr) (add_clock lhs_is_mem lhs ck' g) |
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211 | | Clocks.Ccarrying (_, ck') -> add_clock lhs_is_mem lhs ck' g |
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212 | 1b01da98 | ploc | | _ -> g |

213 | in |
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214 | d4807c3d | xthirioux | let rec add_dep lhs_is_mem lhs rhs g = |

215 | 1b01da98 | ploc | (* Add mashup dependencies for a user-defined node instance [lhs] = [f]([e]) *) |

216 | (* i.e every input is connected to every output, through a ghost var *) |
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217 | 22fe1c93 | ploc | let mashup_appl_dependencies f e g = |

218 | let f_var = mk_instance_var (sprintf "%s_%d" f eq.eq_loc.Location.loc_start.Lexing.pos_lnum) in |
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219 | List.fold_right (fun rhs -> add_dep lhs_is_mem (adjust_tuple f_var rhs) rhs) |
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220 | 1b01da98 | ploc | (expr_list_of_expr e) (add_var lhs_is_mem lhs f_var g) |

221 | in |
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222 | 22fe1c93 | ploc | match rhs.expr_desc with |

223 | | Expr_const _ -> g |
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224 | | Expr_fby (e1, e2) -> add_dep true lhs e2 (add_dep false lhs e1 g) |
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225 | | Expr_pre e -> add_dep true lhs e g |
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226 | d4807c3d | xthirioux | | Expr_ident x -> add_var lhs_is_mem lhs x (add_clock lhs_is_mem lhs rhs.expr_clock g) |

227 | 2d179f5b | xthirioux | | Expr_access (e1, d) |

228 | | Expr_power (e1, d) -> add_dep lhs_is_mem lhs e1 (add_dep lhs_is_mem lhs (expr_of_dimension d) g) |
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229 | 22fe1c93 | ploc | | Expr_array a -> List.fold_right (add_dep lhs_is_mem lhs) a g |

230 | df39e35a | xthirioux | | Expr_tuple t -> List.fold_right2 (fun l r -> add_dep lhs_is_mem [l] r) lhs t g |

231 | d4807c3d | xthirioux | | Expr_merge (c, hl) -> add_var lhs_is_mem lhs c (List.fold_right (fun (_, h) -> add_dep lhs_is_mem lhs h) hl g) |

232 | 22fe1c93 | ploc | | Expr_ite (c, t, e) -> add_dep lhs_is_mem lhs c (add_dep lhs_is_mem lhs t (add_dep lhs_is_mem lhs e g)) |

233 | | Expr_arrow (e1, e2) -> add_dep lhs_is_mem lhs e2 (add_dep lhs_is_mem lhs e1 g) |
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234 | d4807c3d | xthirioux | | Expr_when (e, c, _) -> add_dep lhs_is_mem lhs e (add_var lhs_is_mem lhs c g) |

235 | 22fe1c93 | ploc | | Expr_appl (f, e, None) -> |

236 | 04a63d25 | xthirioux | if Basic_library.is_expr_internal_fun rhs |

237 | 1b01da98 | ploc | (* tuple component-wise dependency for internal operators *) |

238 | 22fe1c93 | ploc | then |

239 | List.fold_right (add_dep lhs_is_mem lhs) (expr_list_of_expr e) g |
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240 | 1b01da98 | ploc | (* mashed up dependency for user-defined operators *) |

241 | 22fe1c93 | ploc | else |

242 | mashup_appl_dependencies f e g |
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243 | 54d032f5 | xthirioux | | Expr_appl (f, e, Some c) -> |

244 | mashup_appl_dependencies f e (add_dep lhs_is_mem lhs c g) |
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245 | 22fe1c93 | ploc | in |

246 | 3bfed7f9 | xthirioux | let g = |

247 | List.fold_left |
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248 | c9043042 | ploc | (fun g lhs -> |

249 | if ISet.mem lhs mems then |
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250 | add_vertices [lhs; mk_read_var lhs] g |
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251 | else |
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252 | add_vertices [lhs] g |
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253 | ) |
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254 | g eq.eq_lhs |
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255 | in |
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256 | 3bfed7f9 | xthirioux | add_dep false eq.eq_lhs eq.eq_rhs (g, g') |

257 | 22fe1c93 | ploc | |

258 | |||

259 | (* Returns the dependence graph for node [n] *) |
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260 | 3bfed7f9 | xthirioux | let dependence_graph mems inputs node_vars n = |

261 | 22fe1c93 | ploc | instance_var_cpt := 0; |

262 | let g = new_graph (), new_graph () in |
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263 | (* Basic dependencies *) |
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264 | b08ffca7 | xthirioux | let g = List.fold_right (add_eq_dependencies mems inputs node_vars) (get_node_eqs n) g in |

265 | c9043042 | ploc | (* TODO Xavier: un essai ci dessous. Ca n'a pas l'air de résoudre le pb. Il |

266 | faut imposer que les outputs dépendent des asserts pour identifier que les |
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267 | fcn calls des asserts sont évalués avant le noeuds *) |
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268 | |||

269 | (* (\* In order to introduce dependencies between assert expressions and the node, *) |
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270 | (* we build an artificial dependency between node output and each assert *) |
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271 | (* expr. While these are not valid equations, they should properly propage in *) |
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272 | (* function add_eq_dependencies *\) *) |
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273 | (* let g = *) |
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274 | (* let output_vars_as_lhs = ISet.elements (node_output_variables n) in *) |
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275 | (* List.fold_left (fun g ae -> *) |
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276 | (* let fake_eq = mkeq Location.dummy_loc (output_vars_as_lhs, ae.assert_expr) in *) |
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277 | (* add_eq_dependencies mems inputs node_vars fake_eq g *) |
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278 | (* ) g n.node_asserts in *) |
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279 | 22fe1c93 | ploc | g |

280 | |||

281 | c9043042 | ploc | end |

282 | |||

283 | module NodeDep = struct |
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284 | |||

285 | module ExprModule = |
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286 | struct |
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287 | type t = expr |
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288 | let compare = compare |
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289 | let hash n = Hashtbl.hash n |
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290 | let equal n1 n2 = n1 = n2 |
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291 | end |
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292 | |||

293 | module ESet = Set.Make(ExprModule) |
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294 | |||

295 | let rec get_expr_calls prednode expr = |
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296 | match expr.expr_desc with |
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297 | | Expr_const _ |
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298 | | Expr_ident _ -> ESet.empty |
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299 | | Expr_access (e, _) |
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300 | | Expr_power (e, _) -> get_expr_calls prednode e |
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301 | | Expr_array t |
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302 | | Expr_tuple t -> List.fold_right (fun x set -> ESet.union (get_expr_calls prednode x) set) t ESet.empty |
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303 | | Expr_merge (_,hl) -> List.fold_right (fun (_,h) set -> ESet.union (get_expr_calls prednode h) set) hl ESet.empty |
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304 | | Expr_fby (e1,e2) |
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305 | | Expr_arrow (e1,e2) -> ESet.union (get_expr_calls prednode e1) (get_expr_calls prednode e2) |
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306 | | Expr_ite (c, t, e) -> ESet.union (get_expr_calls prednode c) (ESet.union (get_expr_calls prednode t) (get_expr_calls prednode e)) |
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307 | | Expr_pre e |
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308 | | Expr_when (e,_,_) -> get_expr_calls prednode e |
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309 | | Expr_appl (id,e, _) -> |
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310 | if not (Basic_library.is_expr_internal_fun expr) && prednode id |
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311 | then ESet.add expr (get_expr_calls prednode e) |
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312 | else (get_expr_calls prednode e) |
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313 | |||

314 | let get_callee expr = |
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315 | match expr.expr_desc with |
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316 | | Expr_appl (id, args, _) -> Some (id, expr_list_of_expr args) |
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317 | | _ -> None |
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318 | |||

319 | let get_calls prednode eqs = |
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320 | let deps = |
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321 | List.fold_left |
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322 | (fun accu eq -> ESet.union accu (get_expr_calls prednode eq.eq_rhs)) |
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323 | ESet.empty |
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324 | eqs in |
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325 | ESet.elements deps |
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326 | |||

327 | let dependence_graph prog = |
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328 | let g = new_graph () in |
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329 | let g = List.fold_right |
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330 | (fun td accu -> (* for each node we add its dependencies *) |
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331 | 22fe1c93 | ploc | match td.top_decl_desc with |

332 | | Node nd -> |
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333 | (*Format.eprintf "Computing deps of node %s@.@?" nd.node_id; *) |
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334 | let accu = add_vertices [nd.node_id] accu in |
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335 | b08ffca7 | xthirioux | let deps = List.map (fun e -> fst (desome (get_callee e))) (get_calls (fun _ -> true) (get_node_eqs nd)) in |

336 | 22fe1c93 | ploc | (*Format.eprintf "%a@.@?" (Utils.fprintf_list ~sep:"@." Format.pp_print_string) deps; *) |

337 | add_edges [nd.node_id] deps accu |
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338 | | _ -> assert false (* should not happen *) |
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339 | |||

340 | ) prog g in |
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341 | g |
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342 | |||

343 | eb837d74 | xthirioux | (* keep subgraph of [gr] consisting of nodes accessible from node [v] *) |

344 | let slice_graph gr v = |
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345 | begin |
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346 | let gr' = new_graph () in |
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347 | IdentDepGraph.add_vertex gr' v; |
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348 | Bfs.iter_component (fun v -> IdentDepGraph.iter_succ (fun s -> IdentDepGraph.add_vertex gr' s; IdentDepGraph.add_edge gr' v s) gr v) gr v; |
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349 | gr' |
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350 | end |
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351 | |||

352 | 22fe1c93 | ploc | let rec filter_static_inputs inputs args = |

353 | match inputs, args with |
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354 | | [] , [] -> [] |
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355 | 7d640c88 | ploc | | v::vq, a::aq -> if v.var_dec_const && Types.is_dimension_type v.var_type then (dimension_of_expr a) :: filter_static_inputs vq aq else filter_static_inputs vq aq |

356 | 22fe1c93 | ploc | | _ -> assert false |

357 | |||

358 | let compute_generic_calls prog = |
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359 | List.iter |
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360 | (fun td -> |
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361 | match td.top_decl_desc with |
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362 | | Node nd -> |
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363 | let prednode n = is_generic_node (Hashtbl.find node_table n) in |
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364 | b08ffca7 | xthirioux | nd.node_gencalls <- get_calls prednode (get_node_eqs nd) |

365 | 22fe1c93 | ploc | | _ -> () |

366 | |||

367 | ) prog |
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368 | |||

369 | end |
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370 | |||

371 | module CycleDetection = struct |
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372 | |||

373 | (* ---- Look for cycles in a dependency graph *) |
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374 | module Cycles = Graph.Components.Make (IdentDepGraph) |
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375 | |||

376 | let mk_copy_var n id = |
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377 | b08ffca7 | xthirioux | let used name = |

378 | (List.exists (fun v -> v.var_id = name) n.node_locals) |
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379 | || (List.exists (fun v -> v.var_id = name) n.node_inputs) |
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380 | || (List.exists (fun v -> v.var_id = name) n.node_outputs) |
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381 | in mk_new_name used id |
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382 | 22fe1c93 | ploc | |

383 | let mk_copy_eq n var = |
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384 | 01c7d5e1 | ploc | let var_decl = get_node_var var n in |

385 | 22fe1c93 | ploc | let cp_var = mk_copy_var n var in |

386 | let expr = |
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387 | { expr_tag = Utils.new_tag (); |
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388 | expr_desc = Expr_ident var; |
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389 | expr_type = var_decl.var_type; |
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390 | expr_clock = var_decl.var_clock; |
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391 | expr_delay = Delay.new_var (); |
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392 | expr_annot = None; |
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393 | expr_loc = var_decl.var_loc } in |
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394 | 54d032f5 | xthirioux | { var_decl with var_id = cp_var; var_orig = false }, |

395 | 22fe1c93 | ploc | mkeq var_decl.var_loc ([cp_var], expr) |

396 | |||

397 | let wrong_partition g partition = |
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398 | match partition with |
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399 | | [id] -> IdentDepGraph.mem_edge g id id |
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400 | | _::_::_ -> true |
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401 | | [] -> assert false |
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402 | |||

403 | (* Checks that the dependency graph [g] does not contain a cycle. Raises |
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404 | [Cycle partition] if the succession of dependencies [partition] forms a cycle *) |
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405 | let check_cycles g = |
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406 | let scc_l = Cycles.scc_list g in |
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407 | List.iter (fun partition -> |
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408 | if wrong_partition g partition then |
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409 | eb837d74 | xthirioux | raise (Error (DataCycle partition)) |

410 | 22fe1c93 | ploc | else () |

411 | ) scc_l |
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412 | |||

413 | (* Creates the sub-graph of [g] restricted to vertices and edges in partition *) |
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414 | let copy_partition g partition = |
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415 | let copy_g = IdentDepGraph.create () in |
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416 | IdentDepGraph.iter_edges |
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417 | (fun src tgt -> |
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418 | if List.mem src partition && List.mem tgt partition |
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419 | then IdentDepGraph.add_edge copy_g src tgt) |
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420 | g |
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421 | |||

422 | |||

423 | (* Breaks dependency cycles in a graph [g] by inserting aux variables. |
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424 | [head] is a head of a non-trivial scc of [g]. |
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425 | In Lustre, this is legal only for mem/mem cycles *) |
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426 | let break_cycle head cp_head g = |
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427 | let succs = IdentDepGraph.succ g head in |
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428 | IdentDepGraph.add_edge g head cp_head; |
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429 | 3bfed7f9 | xthirioux | IdentDepGraph.add_edge g cp_head (ExprDep.mk_read_var head); |

430 | 22fe1c93 | ploc | List.iter |

431 | (fun s -> |
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432 | IdentDepGraph.remove_edge g head s; |
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433 | IdentDepGraph.add_edge g s cp_head) |
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434 | succs |
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435 | |||

436 | (* Breaks cycles of the dependency graph [g] of memory variables [mems] |
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437 | belonging in node [node]. Returns: |
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438 | - a list of new auxiliary variable declarations |
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439 | - a list of new equations |
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440 | - a modified acyclic version of [g] |
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441 | *) |
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442 | let break_cycles node mems g = |
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443 | b08ffca7 | xthirioux | let (mem_eqs, non_mem_eqs) = List.partition (fun eq -> List.exists (fun v -> ISet.mem v mems) eq.eq_lhs) (get_node_eqs node) in |

444 | 22fe1c93 | ploc | let rec break vdecls mem_eqs g = |

445 | let scc_l = Cycles.scc_list g in |
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446 | let wrong = List.filter (wrong_partition g) scc_l in |
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447 | match wrong with |
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448 | | [] -> (vdecls, non_mem_eqs@mem_eqs, g) |
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449 | | [head]::_ -> |
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450 | begin |
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451 | IdentDepGraph.remove_edge g head head; |
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452 | break vdecls mem_eqs g |
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453 | end |
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454 | | (head::part)::_ -> |
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455 | begin |
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456 | let vdecl_cp_head, cp_eq = mk_copy_eq node head in |
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457 | let pvar v = List.mem v part in |
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458 | let fvar v = if v = head then vdecl_cp_head.var_id else v in |
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459 | let mem_eqs' = List.map (eq_replace_rhs_var pvar fvar) mem_eqs in |
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460 | break_cycle head vdecl_cp_head.var_id g; |
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461 | break (vdecl_cp_head::vdecls) (cp_eq::mem_eqs') g |
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462 | end |
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463 | | _ -> assert false |
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464 | in break [] mem_eqs g |
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465 | |||

466 | end |
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467 | |||

468 | 8f89eba8 | xthirioux | (* Module used to compute static disjunction of variables based upon their clocks. *) |

469 | module Disjunction = |
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470 | struct |
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471 | add75bcb | xthirioux | module ClockedIdentModule = |

472 | struct |
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473 | type t = var_decl |
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474 | let root_branch vdecl = Clocks.root vdecl.var_clock, Clocks.branch vdecl.var_clock |
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475 | 28c58de1 | xthirioux | let compare v1 v2 = compare (root_branch v2, v2.var_id) (root_branch v1, v1.var_id) |

476 | add75bcb | xthirioux | end |

477 | |||

478 | module CISet = Set.Make(ClockedIdentModule) |
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479 | 8f89eba8 | xthirioux | |

480 | add75bcb | xthirioux | (* map: var |-> list of disjoint vars, sorted in increasing branch length order, |

481 | maybe removing shorter branches *) |
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482 | b6a94a4e | xthirioux | type disjoint_map = (ident, CISet.t) Hashtbl.t |

483 | 8f89eba8 | xthirioux | |

484 | a38c681e | xthirioux | let pp_ciset fmt t = |

485 | begin |
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486 | Format.fprintf fmt "{@ "; |
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487 | CISet.iter (fun s -> Format.fprintf fmt "%a@ " Printers.pp_var_name s) t; |
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488 | Format.fprintf fmt "}@." |
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489 | end |
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490 | |||

491 | b1a97ade | xthirioux | let clock_disjoint_map vdecls = |

492 | 8f89eba8 | xthirioux | let map = Hashtbl.create 23 in |

493 | begin |
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494 | add75bcb | xthirioux | List.iter |

495 | (fun v1 -> let disj_v1 = |
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496 | List.fold_left |
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497 | b6a94a4e | xthirioux | (fun res v2 -> if Clocks.disjoint v1.var_clock v2.var_clock then CISet.add v2 res else res) |

498 | CISet.empty |
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499 | add75bcb | xthirioux | vdecls in |

500 | (* disjoint vdecls are stored in increasing branch length order *) |
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501 | Hashtbl.add map v1.var_id disj_v1) |
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502 | vdecls; |
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503 | b6a94a4e | xthirioux | (map : disjoint_map) |

504 | 8f89eba8 | xthirioux | end |

505 | b1a97ade | xthirioux | |

506 | 45c13277 | xthirioux | (* merge variables [v] and [v'] in disjunction [map]. Then: |

507 | bb2ca5f4 | xthirioux | - the mapping v' becomes v' |-> (map v) inter (map v') |

508 | - the mapping v |-> ... then disappears |
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509 | - other mappings become x |-> (map x) \ (if v in x then v else v') |
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510 | add75bcb | xthirioux | *) |

511 | 45c13277 | xthirioux | let merge_in_disjoint_map map v v' = |

512 | add75bcb | xthirioux | begin |

513 | b6a94a4e | xthirioux | Hashtbl.replace map v'.var_id (CISet.inter (Hashtbl.find map v.var_id) (Hashtbl.find map v'.var_id)); |

514 | Hashtbl.remove map v.var_id; |
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515 | Hashtbl.iter (fun x map_x -> Hashtbl.replace map x (CISet.remove (if CISet.mem v map_x then v else v') map_x)) map; |
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516 | add75bcb | xthirioux | end |

517 | |||

518 | 45c13277 | xthirioux | (* replace variable [v] by [v'] in disjunction [map]. |

519 | [v'] is a dead variable. Then: |
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520 | - the mapping v' becomes v' |-> (map v) |
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521 | - the mapping v |-> ... then disappears |
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522 | - all mappings become x |-> ((map x) \ { v}) union ({v'} if v in map x) |
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523 | *) |
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524 | let replace_in_disjoint_map map v v' = |
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525 | begin |
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526 | Hashtbl.replace map v'.var_id (Hashtbl.find map v.var_id); |
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527 | Hashtbl.remove map v.var_id; |
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528 | Hashtbl.iter (fun x mapx -> Hashtbl.replace map x (if CISet.mem v mapx then CISet.add v' (CISet.remove v mapx) else CISet.remove v' mapx)) map; |
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529 | end |
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530 | |||

531 | (* remove variable [v] in disjunction [map]. Then: |
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532 | - the mapping v |-> ... then disappears |
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533 | - all mappings become x |-> (map x) \ { v} |
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534 | *) |
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535 | let remove_in_disjoint_map map v = |
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536 | begin |
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537 | Hashtbl.remove map v.var_id; |
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538 | Hashtbl.iter (fun x mapx -> Hashtbl.replace map x (CISet.remove v mapx)) map; |
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539 | end |
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540 | |||

541 | b1a97ade | xthirioux | let pp_disjoint_map fmt map = |

542 | begin |
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543 | Format.fprintf fmt "{ /* disjoint map */@."; |
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544 | b6a94a4e | xthirioux | Hashtbl.iter (fun k v -> Format.fprintf fmt "%s # { %a }@." k (Utils.fprintf_list ~sep:", " Printers.pp_var_name) (CISet.elements v)) map; |

545 | b1a97ade | xthirioux | Format.fprintf fmt "}@." |

546 | end |
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547 | 8f89eba8 | xthirioux | end |

548 | |||

549 | 22fe1c93 | ploc | let pp_dep_graph fmt g = |

550 | begin |
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551 | Format.fprintf fmt "{ /* graph */@."; |
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552 | IdentDepGraph.iter_edges (fun s t -> Format.fprintf fmt "%s -> %s@." s t) g; |
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553 | Format.fprintf fmt "}@." |
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554 | end |
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555 | |||

556 | eb837d74 | xthirioux | let pp_error fmt err = |

557 | match err with |
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558 | | DataCycle trace -> |
||

559 | fprintf fmt "@.Causality error, cyclic data dependencies: %a@." |
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560 | (fprintf_list ~sep:", " pp_print_string) trace |
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561 | | NodeCycle trace -> |
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562 | fprintf fmt "@.Causality error, cyclic node calls: %a@." |
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563 | (fprintf_list ~sep:", " pp_print_string) trace |
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564 | 22fe1c93 | ploc | |

565 | (* Merges elements of graph [g2] into graph [g1] *) |
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566 | b1a97ade | xthirioux | let merge_with g1 g2 = |

567 | 45c13277 | xthirioux | begin |

568 | 22fe1c93 | ploc | IdentDepGraph.iter_vertex (fun v -> IdentDepGraph.add_vertex g1 v) g2; |

569 | IdentDepGraph.iter_edges (fun s t -> IdentDepGraph.add_edge g1 s t) g2 |
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570 | 45c13277 | xthirioux | end |

571 | |||

572 | 57115ec0 | xthirioux | let world = "!!_world" |

573 | |||

574 | 45c13277 | xthirioux | let add_external_dependency outputs mems g = |

575 | begin |
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576 | 57115ec0 | xthirioux | IdentDepGraph.add_vertex g world; |

577 | ISet.iter (fun o -> IdentDepGraph.add_edge g world o) outputs; |
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578 | ISet.iter (fun m -> IdentDepGraph.add_edge g world m) mems; |
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579 | 45c13277 | xthirioux | end |

580 | 22fe1c93 | ploc | |

581 | let global_dependency node = |
||

582 | let mems = ExprDep.node_memory_variables node in |
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583 | ec433d69 | xthirioux | let inputs = |

584 | ISet.union |
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585 | (ExprDep.node_input_variables node) |
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586 | (ExprDep.node_constant_variables node) in |
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587 | 45c13277 | xthirioux | let outputs = ExprDep.node_output_variables node in |

588 | 3bfed7f9 | xthirioux | let node_vars = ExprDep.node_variables node in |

589 | let (g_non_mems, g_mems) = ExprDep.dependence_graph mems inputs node_vars node in |
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590 | 22fe1c93 | ploc | (*Format.eprintf "g_non_mems: %a" pp_dep_graph g_non_mems; |

591 | Format.eprintf "g_mems: %a" pp_dep_graph g_mems;*) |
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592 | CycleDetection.check_cycles g_non_mems; |
||

593 | let (vdecls', eqs', g_mems') = CycleDetection.break_cycles node mems g_mems in |
||

594 | (*Format.eprintf "g_mems': %a" pp_dep_graph g_mems';*) |
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595 | 45c13277 | xthirioux | begin |

596 | merge_with g_non_mems g_mems'; |
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597 | add_external_dependency outputs mems g_non_mems; |
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598 | b08ffca7 | xthirioux | { node with node_stmts = List.map (fun eq -> Eq eq) eqs'; node_locals = vdecls'@node.node_locals }, |

599 | 45c13277 | xthirioux | g_non_mems |

600 | end |
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601 | 22fe1c93 | ploc | |

602 | (* Local Variables: *) |
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603 | (* compile-command:"make -C .." *) |
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604 | (* End: *) |