1 | /* |
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2 | * Copyright 1997, Regents of the University of Minnesota |
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3 | * |
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4 | * initpart.c |
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5 | * |
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6 | * This file contains code that performs the initial partition of the |
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7 | * coarsest graph |
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8 | * |
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9 | * Started 7/23/97 |
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10 | * George |
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11 | * |
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12 | * $Id: initpart.c,v 1.1 1998/11/27 17:59:15 karypis Exp $ |
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13 | * |
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14 | */ |
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15 | |
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16 | #include <metis.h> |
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17 | |
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18 | /************************************************************************* |
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19 | * This function computes the initial bisection of the coarsest graph |
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20 | **************************************************************************/ |
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21 | void Init2WayPartition(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor) |
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22 | { |
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23 | int dbglvl; |
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24 | |
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25 | dbglvl = ctrl->dbglvl; |
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26 | IFSET(ctrl->dbglvl, DBG_REFINE, ctrl->dbglvl -= DBG_REFINE); |
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27 | IFSET(ctrl->dbglvl, DBG_MOVEINFO, ctrl->dbglvl -= DBG_MOVEINFO); |
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28 | |
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29 | IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->InitPartTmr)); |
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30 | |
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31 | switch (ctrl->IType) { |
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32 | case IPART_GGPKL: |
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33 | GrowBisection(ctrl, graph, tpwgts, ubfactor); |
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34 | break; |
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35 | case 3: |
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36 | RandomBisection(ctrl, graph, tpwgts, ubfactor); |
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37 | break; |
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38 | default: |
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39 | errexit("Unknown initial partition type: %d\n", ctrl->IType); |
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40 | } |
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41 | |
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42 | IFSET(ctrl->dbglvl, DBG_IPART, printf("Initial Cut: %d\n", graph->mincut)); |
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43 | IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->InitPartTmr)); |
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44 | ctrl->dbglvl = dbglvl; |
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45 | |
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46 | /* |
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47 | IsConnectedSubdomain(ctrl, graph, 0); |
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48 | IsConnectedSubdomain(ctrl, graph, 1); |
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49 | */ |
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50 | } |
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51 | |
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52 | /************************************************************************* |
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53 | * This function computes the initial bisection of the coarsest graph |
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54 | **************************************************************************/ |
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55 | void InitSeparator(CtrlType *ctrl, GraphType *graph, float ubfactor) |
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56 | { |
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57 | int dbglvl; |
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58 | |
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59 | dbglvl = ctrl->dbglvl; |
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60 | IFSET(ctrl->dbglvl, DBG_REFINE, ctrl->dbglvl -= DBG_REFINE); |
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61 | IFSET(ctrl->dbglvl, DBG_MOVEINFO, ctrl->dbglvl -= DBG_MOVEINFO); |
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62 | |
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63 | IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->InitPartTmr)); |
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64 | |
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65 | GrowBisectionNode(ctrl, graph, ubfactor); |
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66 | Compute2WayNodePartitionParams(ctrl, graph); |
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67 | |
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68 | IFSET(ctrl->dbglvl, DBG_IPART, printf("Initial Sep: %d\n", graph->mincut)); |
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69 | IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->InitPartTmr)); |
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70 | |
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71 | ctrl->dbglvl = dbglvl; |
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72 | |
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73 | } |
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74 | |
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75 | |
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76 | |
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77 | /************************************************************************* |
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78 | * This function takes a graph and produces a bisection by using a region |
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79 | * growing algorithm. The resulting partition is returned in |
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80 | * graph->where |
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81 | **************************************************************************/ |
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82 | void GrowBisection(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor) |
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83 | { |
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84 | int i, j, k, nvtxs, drain, nleft, first, last, pwgts[2], minpwgt[2], maxpwgt[2], from, bestcut, icut, mincut, me, pass, nbfs; |
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85 | idxtype *xadj, *vwgt, *adjncy, *adjwgt, *where; |
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86 | idxtype *queue, *touched, *gain, *bestwhere; |
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87 | |
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88 | |
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89 | nvtxs = graph->nvtxs; |
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90 | xadj = graph->xadj; |
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91 | vwgt = graph->vwgt; |
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92 | adjncy = graph->adjncy; |
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93 | adjwgt = graph->adjwgt; |
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94 | |
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95 | Allocate2WayPartitionMemory(ctrl, graph); |
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96 | where = graph->where; |
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97 | |
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98 | bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere"); |
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99 | queue = idxmalloc(nvtxs, "BisectGraph: queue"); |
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100 | touched = idxmalloc(nvtxs, "BisectGraph: touched"); |
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101 | |
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102 | ASSERTP(tpwgts[0]+tpwgts[1] == idxsum(nvtxs, vwgt), ("%d %d\n", tpwgts[0]+tpwgts[1], idxsum(nvtxs, vwgt))); |
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103 | |
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104 | maxpwgt[0] = ubfactor*tpwgts[0]; |
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105 | maxpwgt[1] = ubfactor*tpwgts[1]; |
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106 | minpwgt[0] = (1.0/ubfactor)*tpwgts[0]; |
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107 | minpwgt[1] = (1.0/ubfactor)*tpwgts[1]; |
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108 | |
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109 | nbfs = (nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS); |
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110 | bestcut = idxsum(nvtxs, graph->adjwgtsum)+1; /* The +1 is for the 0 edges case */ |
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111 | for (; nbfs>0; nbfs--) { |
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112 | idxset(nvtxs, 0, touched); |
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113 | |
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114 | pwgts[1] = tpwgts[0]+tpwgts[1]; |
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115 | pwgts[0] = 0; |
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116 | |
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117 | idxset(nvtxs, 1, where); |
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118 | |
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119 | queue[0] = RandomInRange(nvtxs); |
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120 | touched[queue[0]] = 1; |
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121 | first = 0; last = 1; |
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122 | nleft = nvtxs-1; |
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123 | drain = 0; |
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124 | |
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125 | /* Start the BFS from queue to get a partition */ |
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126 | for (;;) { |
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127 | if (first == last) { /* Empty. Disconnected graph! */ |
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128 | if (nleft == 0 || drain) |
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129 | break; |
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130 | |
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131 | k = RandomInRange(nleft); |
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132 | for (i=0; i<nvtxs; i++) { |
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133 | if (touched[i] == 0) { |
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134 | if (k == 0) |
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135 | break; |
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136 | else |
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137 | k--; |
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138 | } |
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139 | } |
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140 | |
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141 | queue[0] = i; |
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142 | touched[i] = 1; |
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143 | first = 0; last = 1;; |
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144 | nleft--; |
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145 | } |
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146 | |
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147 | i = queue[first++]; |
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148 | if (pwgts[0] > 0 && pwgts[1]-vwgt[i] < minpwgt[1]) { |
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149 | drain = 1; |
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150 | continue; |
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151 | } |
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152 | |
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153 | where[i] = 0; |
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154 | INC_DEC(pwgts[0], pwgts[1], vwgt[i]); |
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155 | if (pwgts[1] <= maxpwgt[1]) |
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156 | break; |
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157 | |
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158 | drain = 0; |
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159 | for (j=xadj[i]; j<xadj[i+1]; j++) { |
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160 | k = adjncy[j]; |
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161 | if (touched[k] == 0) { |
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162 | queue[last++] = k; |
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163 | touched[k] = 1; |
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164 | nleft--; |
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165 | } |
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166 | } |
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167 | } |
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168 | |
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169 | /* Check to see if we hit any bad limiting cases */ |
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170 | if (pwgts[1] == 0) { |
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171 | i = RandomInRange(nvtxs); |
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172 | where[i] = 1; |
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173 | INC_DEC(pwgts[1], pwgts[0], vwgt[i]); |
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174 | } |
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175 | |
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176 | /************************************************************* |
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177 | * Do some partition refinement |
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178 | **************************************************************/ |
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179 | Compute2WayPartitionParams(ctrl, graph); |
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180 | /*printf("IPART: %3d [%5d %5d] [%5d %5d] %5d\n", graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut); */ |
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181 | |
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182 | Balance2Way(ctrl, graph, tpwgts, ubfactor); |
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183 | /*printf("BPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut);*/ |
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184 | |
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185 | FM_2WayEdgeRefine(ctrl, graph, tpwgts, 4); |
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186 | /*printf("RPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut);*/ |
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187 | |
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188 | if (bestcut > graph->mincut) { |
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189 | bestcut = graph->mincut; |
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190 | idxcopy(nvtxs, where, bestwhere); |
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191 | if (bestcut == 0) |
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192 | break; |
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193 | } |
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194 | } |
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195 | |
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196 | graph->mincut = bestcut; |
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197 | idxcopy(nvtxs, bestwhere, where); |
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198 | |
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199 | GKfree(&bestwhere, &queue, &touched, LTERM); |
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200 | } |
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201 | |
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202 | |
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203 | |
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204 | |
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205 | /************************************************************************* |
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206 | * This function takes a graph and produces a bisection by using a region |
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207 | * growing algorithm. The resulting partition is returned in |
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208 | * graph->where |
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209 | **************************************************************************/ |
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210 | void GrowBisectionNode(CtrlType *ctrl, GraphType *graph, float ubfactor) |
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211 | { |
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212 | int i, j, k, nvtxs, drain, nleft, first, last, pwgts[2], tpwgts[2], minpwgt[2], maxpwgt[2], from, bestcut, icut, mincut, me, pass, nbfs; |
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213 | idxtype *xadj, *vwgt, *adjncy, *adjwgt, *where, *bndind; |
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214 | idxtype *queue, *touched, *gain, *bestwhere; |
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215 | |
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216 | nvtxs = graph->nvtxs; |
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217 | xadj = graph->xadj; |
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218 | vwgt = graph->vwgt; |
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219 | adjncy = graph->adjncy; |
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220 | adjwgt = graph->adjwgt; |
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221 | |
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222 | bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere"); |
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223 | queue = idxmalloc(nvtxs, "BisectGraph: queue"); |
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224 | touched = idxmalloc(nvtxs, "BisectGraph: touched"); |
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225 | |
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226 | tpwgts[0] = idxsum(nvtxs, vwgt); |
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227 | tpwgts[1] = tpwgts[0]/2; |
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228 | tpwgts[0] -= tpwgts[1]; |
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229 | |
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230 | maxpwgt[0] = ubfactor*tpwgts[0]; |
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231 | maxpwgt[1] = ubfactor*tpwgts[1]; |
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232 | minpwgt[0] = (1.0/ubfactor)*tpwgts[0]; |
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233 | minpwgt[1] = (1.0/ubfactor)*tpwgts[1]; |
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234 | |
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235 | /* Allocate memory for graph->rdata. Allocate sufficient memory for both edge and node */ |
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236 | graph->rdata = idxmalloc(5*nvtxs+3, "GrowBisectionNode: graph->rdata"); |
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237 | graph->pwgts = graph->rdata; |
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238 | graph->where = graph->rdata + 3; |
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239 | graph->bndptr = graph->rdata + nvtxs + 3; |
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240 | graph->bndind = graph->rdata + 2*nvtxs + 3; |
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241 | graph->nrinfo = (NRInfoType *)(graph->rdata + 3*nvtxs + 3); |
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242 | graph->id = graph->rdata + 3*nvtxs + 3; |
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243 | graph->ed = graph->rdata + 4*nvtxs + 3; |
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244 | |
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245 | where = graph->where; |
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246 | bndind = graph->bndind; |
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247 | |
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248 | nbfs = (nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS); |
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249 | bestcut = tpwgts[0]+tpwgts[1]; |
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250 | for (nbfs++; nbfs>0; nbfs--) { |
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251 | idxset(nvtxs, 0, touched); |
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252 | |
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253 | pwgts[1] = tpwgts[0]+tpwgts[1]; |
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254 | pwgts[0] = 0; |
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255 | |
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256 | idxset(nvtxs, 1, where); |
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257 | |
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258 | queue[0] = RandomInRange(nvtxs); |
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259 | touched[queue[0]] = 1; |
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260 | first = 0; last = 1; |
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261 | nleft = nvtxs-1; |
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262 | drain = 0; |
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263 | |
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264 | /* Start the BFS from queue to get a partition */ |
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265 | if (nbfs >= 1) { |
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266 | for (;;) { |
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267 | if (first == last) { /* Empty. Disconnected graph! */ |
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268 | if (nleft == 0 || drain) |
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269 | break; |
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270 | |
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271 | k = RandomInRange(nleft); |
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272 | for (i=0; i<nvtxs; i++) { |
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273 | if (touched[i] == 0) { |
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274 | if (k == 0) |
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275 | break; |
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276 | else |
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277 | k--; |
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278 | } |
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279 | } |
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280 | |
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281 | queue[0] = i; |
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282 | touched[i] = 1; |
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283 | first = 0; last = 1;; |
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284 | nleft--; |
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285 | } |
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286 | |
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287 | i = queue[first++]; |
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288 | if (pwgts[1]-vwgt[i] < minpwgt[1]) { |
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289 | drain = 1; |
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290 | continue; |
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291 | } |
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292 | |
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293 | where[i] = 0; |
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294 | INC_DEC(pwgts[0], pwgts[1], vwgt[i]); |
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295 | if (pwgts[1] <= maxpwgt[1]) |
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296 | break; |
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297 | |
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298 | drain = 0; |
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299 | for (j=xadj[i]; j<xadj[i+1]; j++) { |
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300 | k = adjncy[j]; |
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301 | if (touched[k] == 0) { |
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302 | queue[last++] = k; |
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303 | touched[k] = 1; |
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304 | nleft--; |
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305 | } |
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306 | } |
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307 | } |
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308 | } |
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309 | |
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310 | /************************************************************* |
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311 | * Do some partition refinement |
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312 | **************************************************************/ |
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313 | Compute2WayPartitionParams(ctrl, graph); |
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314 | Balance2Way(ctrl, graph, tpwgts, ubfactor); |
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315 | FM_2WayEdgeRefine(ctrl, graph, tpwgts, 4); |
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316 | |
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317 | /* Construct and refine the vertex separator */ |
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318 | for (i=0; i<graph->nbnd; i++) |
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319 | where[bndind[i]] = 2; |
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320 | |
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321 | Compute2WayNodePartitionParams(ctrl, graph); |
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322 | FM_2WayNodeRefine(ctrl, graph, ubfactor, 6); |
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323 | |
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324 | /* printf("ISep: [%d %d %d] %d\n", graph->pwgts[0], graph->pwgts[1], graph->pwgts[2], bestcut); */ |
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325 | |
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326 | if (bestcut > graph->mincut) { |
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327 | bestcut = graph->mincut; |
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328 | idxcopy(nvtxs, where, bestwhere); |
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329 | } |
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330 | } |
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331 | |
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332 | graph->mincut = bestcut; |
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333 | idxcopy(nvtxs, bestwhere, where); |
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334 | |
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335 | Compute2WayNodePartitionParams(ctrl, graph); |
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336 | |
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337 | GKfree(&bestwhere, &queue, &touched, LTERM); |
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338 | } |
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339 | |
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340 | |
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341 | /************************************************************************* |
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342 | * This function takes a graph and produces a bisection by using a region |
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343 | * growing algorithm. The resulting partition is returned in |
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344 | * graph->where |
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345 | **************************************************************************/ |
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346 | void RandomBisection(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor) |
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347 | { |
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348 | int i, ii, j, k, nvtxs, pwgts[2], minpwgt[2], maxpwgt[2], from, bestcut, icut, mincut, me, pass, nbfs; |
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349 | idxtype *xadj, *vwgt, *adjncy, *adjwgt, *where; |
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350 | idxtype *perm, *bestwhere; |
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351 | |
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352 | nvtxs = graph->nvtxs; |
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353 | xadj = graph->xadj; |
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354 | vwgt = graph->vwgt; |
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355 | adjncy = graph->adjncy; |
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356 | adjwgt = graph->adjwgt; |
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357 | |
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358 | Allocate2WayPartitionMemory(ctrl, graph); |
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359 | where = graph->where; |
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360 | |
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361 | bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere"); |
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362 | perm = idxmalloc(nvtxs, "BisectGraph: queue"); |
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363 | |
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364 | ASSERTP(tpwgts[0]+tpwgts[1] == idxsum(nvtxs, vwgt), ("%d %d\n", tpwgts[0]+tpwgts[1], idxsum(nvtxs, vwgt))); |
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365 | |
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366 | maxpwgt[0] = ubfactor*tpwgts[0]; |
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367 | maxpwgt[1] = ubfactor*tpwgts[1]; |
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368 | minpwgt[0] = (1.0/ubfactor)*tpwgts[0]; |
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369 | minpwgt[1] = (1.0/ubfactor)*tpwgts[1]; |
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370 | |
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371 | nbfs = (nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS); |
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372 | bestcut = idxsum(nvtxs, graph->adjwgtsum)+1; /* The +1 is for the 0 edges case */ |
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373 | for (; nbfs>0; nbfs--) { |
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374 | RandomPermute(nvtxs, perm, 1); |
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375 | |
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376 | idxset(nvtxs, 1, where); |
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377 | pwgts[1] = tpwgts[0]+tpwgts[1]; |
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378 | pwgts[0] = 0; |
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379 | |
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380 | |
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381 | if (nbfs != 1) { |
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382 | for (ii=0; ii<nvtxs; ii++) { |
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383 | i = perm[ii]; |
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384 | if (pwgts[0]+vwgt[i] < maxpwgt[0]) { |
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385 | where[i] = 0; |
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386 | pwgts[0] += vwgt[i]; |
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387 | pwgts[1] -= vwgt[i]; |
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388 | if (pwgts[0] > minpwgt[0]) |
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389 | break; |
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390 | } |
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391 | } |
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392 | } |
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393 | |
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394 | /************************************************************* |
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395 | * Do some partition refinement |
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396 | **************************************************************/ |
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397 | Compute2WayPartitionParams(ctrl, graph); |
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398 | /* printf("IPART: %3d [%5d %5d] [%5d %5d] %5d\n", graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut); */ |
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399 | |
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400 | Balance2Way(ctrl, graph, tpwgts, ubfactor); |
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401 | /* printf("BPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */ |
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402 | |
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403 | FM_2WayEdgeRefine(ctrl, graph, tpwgts, 4); |
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404 | /* printf("RPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */ |
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405 | |
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406 | if (bestcut > graph->mincut) { |
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407 | bestcut = graph->mincut; |
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408 | idxcopy(nvtxs, where, bestwhere); |
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409 | if (bestcut == 0) |
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410 | break; |
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411 | } |
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412 | } |
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413 | |
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414 | graph->mincut = bestcut; |
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415 | idxcopy(nvtxs, bestwhere, where); |
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416 | |
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417 | GKfree(&bestwhere, &perm, LTERM); |
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418 | } |
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419 | |
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420 | |
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421 | |
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422 | |
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