Beispiel #1
0
/*************************************************************************
* This function performs k-way refinement
**************************************************************************/
void Moc_KWayFM(CtrlType *ctrl, GraphType *graph, WorkSpaceType *wspace, int npasses)
{
  int h, i, ii, iii, j, k, c;
  int pass, nvtxs, nedges, ncon;
  int nmoves, nmoved, nswaps, nzgswaps;
/*  int gnswaps, gnzgswaps; */
  int me, firstvtx, lastvtx, yourlastvtx;
  int from, to = -1, oldto, oldcut, mydomain, yourdomain, imbalanced, overweight;
  int npes = ctrl->npes, mype = ctrl->mype, nparts = ctrl->nparts;
  int nlupd, nsupd, nnbrs, nchanged;
  idxtype *xadj, *ladjncy, *adjwgt, *vtxdist;
  idxtype *where, *tmp_where, *moved;
  floattype *lnpwgts, *gnpwgts, *ognpwgts, *pgnpwgts, *movewgts, *overfill;
  idxtype *update, *supdate, *rupdate, *pe_updates;
  idxtype *changed, *perm, *pperm, *htable;
  idxtype *peind, *recvptr, *sendptr;
  KeyValueType *swchanges, *rwchanges;
  RInfoType *rinfo, *myrinfo, *tmp_myrinfo, *tmp_rinfo;
  EdgeType *tmp_edegrees, *my_edegrees, *your_edegrees;
  floattype lbvec[MAXNCON], *nvwgt, *badmaxpwgt, *ubvec, *tpwgts, lbavg, ubavg;
  int *nupds_pe;

  IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->KWayTmr));

  /*************************/
  /* set up common aliases */
  /*************************/
  nvtxs = graph->nvtxs;
  nedges = graph->nedges;
  ncon = graph->ncon;

  vtxdist = graph->vtxdist;
  xadj = graph->xadj;
  ladjncy = graph->adjncy;
  adjwgt = graph->adjwgt;

  firstvtx = vtxdist[mype];
  lastvtx = vtxdist[mype+1];

  where   = graph->where;
  rinfo   = graph->rinfo;
  lnpwgts = graph->lnpwgts;
  gnpwgts = graph->gnpwgts;
  ubvec   = ctrl->ubvec;
  tpwgts  = ctrl->tpwgts;

  nnbrs = graph->nnbrs;
  peind = graph->peind;
  recvptr = graph->recvptr;
  sendptr = graph->sendptr;

  changed = idxmalloc(nvtxs, "KWR: changed");
  rwchanges = wspace->pairs;
  swchanges = rwchanges + recvptr[nnbrs];

  /************************************/
  /* set up important data structures */
  /************************************/
  perm = idxmalloc(nvtxs, "KWR: perm");
  pperm = idxmalloc(nparts, "KWR: pperm");

  update = idxmalloc(nvtxs, "KWR: update");
  supdate = wspace->indices;
  rupdate = supdate + recvptr[nnbrs];
  nupds_pe = imalloc(npes, "KWR: nupds_pe");
  htable = idxsmalloc(nvtxs+graph->nrecv, 0, "KWR: lhtable");
  badmaxpwgt = fmalloc(nparts*ncon, "badmaxpwgt");

  for (i=0; i<nparts; i++) {
    for (h=0; h<ncon; h++) {
      badmaxpwgt[i*ncon+h] = ubvec[h]*tpwgts[i*ncon+h];
    }
  }

  movewgts = fmalloc(nparts*ncon, "KWR: movewgts");
  ognpwgts = fmalloc(nparts*ncon, "KWR: ognpwgts");
  pgnpwgts = fmalloc(nparts*ncon, "KWR: pgnpwgts");
  overfill = fmalloc(nparts*ncon, "KWR: overfill");
  moved = idxmalloc(nvtxs, "KWR: moved");
  tmp_where = idxmalloc(nvtxs+graph->nrecv, "KWR: tmp_where");
  tmp_rinfo = (RInfoType *)GKmalloc(sizeof(RInfoType)*nvtxs, "KWR: tmp_rinfo");
  tmp_edegrees = (EdgeType *)GKmalloc(sizeof(EdgeType)*nedges, "KWR: tmp_edegrees");

  idxcopy(nvtxs+graph->nrecv, where, tmp_where);
  for (i=0; i<nvtxs; i++) {
    tmp_rinfo[i].id = rinfo[i].id;
    tmp_rinfo[i].ed = rinfo[i].ed;
    tmp_rinfo[i].ndegrees = rinfo[i].ndegrees;
    tmp_rinfo[i].degrees = tmp_edegrees+xadj[i];

    for (j=0; j<rinfo[i].ndegrees; j++) {
      tmp_rinfo[i].degrees[j].edge = rinfo[i].degrees[j].edge;
      tmp_rinfo[i].degrees[j].ewgt = rinfo[i].degrees[j].ewgt;
    }
  }

  nswaps = nzgswaps = 0;
  /*********************************************************/
  /* perform a small number of passes through the vertices */
  /*********************************************************/
  for (pass=0; pass<npasses; pass++) {
    if (mype == 0)
      RandomPermute(nparts, pperm, 1);
    MPI_Bcast((void *)pperm, nparts, IDX_DATATYPE, 0, ctrl->comm);
    FastRandomPermute(nvtxs, perm, 1);
    oldcut = graph->mincut;

    /* check to see if the partitioning is imbalanced */
    Moc_ComputeParallelBalance(ctrl, graph, graph->where, lbvec);
    ubavg = savg(ncon, ubvec);
    lbavg = savg(ncon, lbvec);
    imbalanced = (lbavg > ubavg) ? 1 : 0;

    for (c=0; c<2; c++) {
      scopy(ncon*nparts, gnpwgts, ognpwgts);
      sset(ncon*nparts, 0.0, movewgts);
      nmoved = 0;

      /**********************************************/
      /* PASS ONE -- record stats for desired moves */
      /**********************************************/
      for (iii=0; iii<nvtxs; iii++) {
        i = perm[iii];
        from = tmp_where[i];
        nvwgt = graph->nvwgt+i*ncon;

        for (h=0; h<ncon; h++)
          if (fabs(nvwgt[h]-gnpwgts[from*ncon+h]) < SMALLFLOAT)
            break;

        if (h < ncon) {
          continue;
        }

        /* check for a potential improvement */
        if (tmp_rinfo[i].ed >= tmp_rinfo[i].id) {
          my_edegrees = tmp_rinfo[i].degrees;

          for (k=0; k<tmp_rinfo[i].ndegrees; k++) {
            to = my_edegrees[k].edge;
            if (ProperSide(c, pperm[from], pperm[to])) {
              for (h=0; h<ncon; h++)
                if (gnpwgts[to*ncon+h]+nvwgt[h] > badmaxpwgt[to*ncon+h] && nvwgt[h] > 0.0)
                  break;

              if (h == ncon)
                break;
            }
          }
          oldto = to;

          /* check if a subdomain was found that fits */
          if (k < tmp_rinfo[i].ndegrees) {
            for (j=k+1; j<tmp_rinfo[i].ndegrees; j++) {
              to = my_edegrees[j].edge;
              if (ProperSide(c, pperm[from], pperm[to])) {
                for (h=0; h<ncon; h++)
                  if (gnpwgts[to*ncon+h]+nvwgt[h] > badmaxpwgt[to*ncon+h] && nvwgt[h] > 0.0)
                    break;

                if (h == ncon) {
                  if (my_edegrees[j].ewgt > my_edegrees[k].ewgt ||
                   (my_edegrees[j].ewgt == my_edegrees[k].ewgt &&
                   IsHBalanceBetterTT(ncon,gnpwgts+oldto*ncon,gnpwgts+to*ncon,nvwgt,ubvec))){
                    k = j;
                    oldto = my_edegrees[k].edge;
                  }
                }
              }
            }
            to = oldto;

            if (my_edegrees[k].ewgt > tmp_rinfo[i].id ||
            (my_edegrees[k].ewgt == tmp_rinfo[i].id &&
            (imbalanced ||  graph->level > 3  || iii % 8 == 0) &&
            IsHBalanceBetterFT(ncon,gnpwgts+from*ncon,gnpwgts+to*ncon,nvwgt,ubvec))){

              /****************************************/
              /* Update tmp arrays of the moved vertex */
              /****************************************/
              tmp_where[i] = to;
              moved[nmoved++] = i;
              for (h=0; h<ncon; h++) {
                lnpwgts[to*ncon+h] += nvwgt[h];
                lnpwgts[from*ncon+h] -= nvwgt[h];
                gnpwgts[to*ncon+h] += nvwgt[h];
                gnpwgts[from*ncon+h] -= nvwgt[h];
                movewgts[to*ncon+h] += nvwgt[h];
                movewgts[from*ncon+h] -= nvwgt[h];
              }

              tmp_rinfo[i].ed += tmp_rinfo[i].id-my_edegrees[k].ewgt;
              SWAP(tmp_rinfo[i].id, my_edegrees[k].ewgt, j);
              if (my_edegrees[k].ewgt == 0) {
                tmp_rinfo[i].ndegrees--;
                my_edegrees[k].edge = my_edegrees[tmp_rinfo[i].ndegrees].edge;
                my_edegrees[k].ewgt = my_edegrees[tmp_rinfo[i].ndegrees].ewgt;
              }
              else {
                my_edegrees[k].edge = from;
              }

              /* Update the degrees of adjacent vertices */
              for (j=xadj[i]; j<xadj[i+1]; j++) {
                /* no need to bother about vertices on different pe's */
                if (ladjncy[j] >= nvtxs)
                  continue;

                me = ladjncy[j];
                mydomain = tmp_where[me];

                myrinfo = tmp_rinfo+me;
                your_edegrees = myrinfo->degrees;

                if (mydomain == from) {
                  INC_DEC(myrinfo->ed, myrinfo->id, adjwgt[j]);
                }
                else {
                  if (mydomain == to) {
                    INC_DEC(myrinfo->id, myrinfo->ed, adjwgt[j]);
                  }
                }

                /* Remove contribution from the .ed of 'from' */
                if (mydomain != from) {
                  for (k=0; k<myrinfo->ndegrees; k++) {
                    if (your_edegrees[k].edge == from) {
                      if (your_edegrees[k].ewgt == adjwgt[j]) {
                        myrinfo->ndegrees--;
                        your_edegrees[k].edge = your_edegrees[myrinfo->ndegrees].edge;
                        your_edegrees[k].ewgt = your_edegrees[myrinfo->ndegrees].ewgt;
                      }
                      else {
                        your_edegrees[k].ewgt -= adjwgt[j];
                      }
                      break;
                    }
                  }
                }

                /* Add contribution to the .ed of 'to' */
                if (mydomain != to) {
                  for (k=0; k<myrinfo->ndegrees; k++) {
                    if (your_edegrees[k].edge == to) {
                      your_edegrees[k].ewgt += adjwgt[j];
                      break;
                    }
                  }
                  if (k == myrinfo->ndegrees) {
                    your_edegrees[myrinfo->ndegrees].edge = to;
                    your_edegrees[myrinfo->ndegrees++].ewgt = adjwgt[j];
                  }
                }
              }
            }
          }
        }
      }

      /******************************************/
      /* Let processors know the subdomain wgts */
      /* if all proposed moves commit.          */
      /******************************************/
      MPI_Allreduce((void *)lnpwgts, (void *)pgnpwgts, nparts*ncon,
      MPI_DOUBLE, MPI_SUM, ctrl->comm);

      /**************************/
      /* compute overfill array */
      /**************************/
      overweight = 0;
      for (j=0; j<nparts; j++) {
        for (h=0; h<ncon; h++) {
          if (pgnpwgts[j*ncon+h] > ognpwgts[j*ncon+h]) {
            overfill[j*ncon+h] =
            (pgnpwgts[j*ncon+h]-badmaxpwgt[j*ncon+h]) /
            (pgnpwgts[j*ncon+h]-ognpwgts[j*ncon+h]);
          }
          else {
            overfill[j*ncon+h] = 0.0;
          }

          overfill[j*ncon+h] = amax(overfill[j*ncon+h], 0.0);
          overfill[j*ncon+h] *= movewgts[j*ncon+h];

          if (overfill[j*ncon+h] > 0.0)
            overweight = 1;

          ASSERTP(ctrl, ognpwgts[j*ncon+h] <= badmaxpwgt[j*ncon+h] ||
          pgnpwgts[j*ncon+h] <= ognpwgts[j*ncon+h],
          (ctrl, "%.4f %.4f %.4f\n", ognpwgts[j*ncon+h],
          badmaxpwgt[j*ncon+h], pgnpwgts[j*ncon+h]));
        }
      }

      /****************************************************/
      /* select moves to undo according to overfill array */
      /****************************************************/
      if (overweight == 1) {
        for (iii=0; iii<nmoved; iii++) {
          i = moved[iii];
          oldto = tmp_where[i];
          nvwgt = graph->nvwgt+i*ncon;
          my_edegrees = tmp_rinfo[i].degrees;

          for (k=0; k<tmp_rinfo[i].ndegrees; k++)
            if (my_edegrees[k].edge == where[i])
              break;

          for (h=0; h<ncon; h++)
            if (nvwgt[h] > 0.0 && overfill[oldto*ncon+h] > nvwgt[h]/4.0)
              break;

          /**********************************/
          /* nullify this move if necessary */
          /**********************************/
          if (k != tmp_rinfo[i].ndegrees && h != ncon) {
            moved[iii] = -1;
            from = oldto;
            to = where[i];

            for (h=0; h<ncon; h++) {
              overfill[oldto*ncon+h] = amax(overfill[oldto*ncon+h]-nvwgt[h], 0.0);
            }

            tmp_where[i] = to;
            tmp_rinfo[i].ed += tmp_rinfo[i].id-my_edegrees[k].ewgt;
            SWAP(tmp_rinfo[i].id, my_edegrees[k].ewgt, j);
            if (my_edegrees[k].ewgt == 0) {
              tmp_rinfo[i].ndegrees--;
              my_edegrees[k].edge = my_edegrees[tmp_rinfo[i].ndegrees].edge;
              my_edegrees[k].ewgt = my_edegrees[tmp_rinfo[i].ndegrees].ewgt;
            }
            else {
              my_edegrees[k].edge = from;
            }

            for (h=0; h<ncon; h++) {
              lnpwgts[to*ncon+h] += nvwgt[h];
              lnpwgts[from*ncon+h] -= nvwgt[h];
            }

            /* Update the degrees of adjacent vertices */
            for (j=xadj[i]; j<xadj[i+1]; j++) {
              /* no need to bother about vertices on different pe's */
              if (ladjncy[j] >= nvtxs)
                continue;

              me = ladjncy[j];
              mydomain = tmp_where[me];

              myrinfo = tmp_rinfo+me;
              your_edegrees = myrinfo->degrees;

              if (mydomain == from) {
                INC_DEC(myrinfo->ed, myrinfo->id, adjwgt[j]);
              }
              else {
                if (mydomain == to) {
                  INC_DEC(myrinfo->id, myrinfo->ed, adjwgt[j]);
                }
              }

              /* Remove contribution from the .ed of 'from' */
              if (mydomain != from) {
                for (k=0; k<myrinfo->ndegrees; k++) {
                  if (your_edegrees[k].edge == from) {
                    if (your_edegrees[k].ewgt == adjwgt[j]) {
                      myrinfo->ndegrees--;
                      your_edegrees[k].edge = your_edegrees[myrinfo->ndegrees].edge;
                      your_edegrees[k].ewgt = your_edegrees[myrinfo->ndegrees].ewgt;
                    }
                    else {
                      your_edegrees[k].ewgt -= adjwgt[j];
                    }
                    break;
                  }
                }
              }

              /* Add contribution to the .ed of 'to' */
              if (mydomain != to) {
                for (k=0; k<myrinfo->ndegrees; k++) {
                  if (your_edegrees[k].edge == to) {
                    your_edegrees[k].ewgt += adjwgt[j];
                    break;
                  }
                }
                if (k == myrinfo->ndegrees) {
                  your_edegrees[myrinfo->ndegrees].edge = to;
                  your_edegrees[myrinfo->ndegrees++].ewgt = adjwgt[j];
                }
              }
            }
          }
        }
      }

      /*************************************************/
      /* PASS TWO -- commit the remainder of the moves */
      /*************************************************/
      nlupd = nsupd = nmoves = nchanged = 0;
      for (iii=0; iii<nmoved; iii++) {
        i = moved[iii];
        if (i == -1)
          continue;

        where[i] = tmp_where[i];

        /* Make sure to update the vertex information */
        if (htable[i] == 0) {
          /* make sure you do the update */
          htable[i] = 1;
          update[nlupd++] = i;
        }

        /* Put the vertices adjacent to i into the update array */
        for (j=xadj[i]; j<xadj[i+1]; j++) {
          k = ladjncy[j];
          if (htable[k] == 0) {
            htable[k] = 1;
            if (k<nvtxs)
              update[nlupd++] = k;
            else
              supdate[nsupd++] = k;
          }
        }
        nmoves++;
        nswaps++;

        /* check number of zero-gain moves */
        for (k=0; k<rinfo[i].ndegrees; k++)
          if (rinfo[i].degrees[k].edge == to)
            break;
        if (rinfo[i].id == rinfo[i].degrees[k].ewgt)
          nzgswaps++;

        if (graph->pexadj[i+1]-graph->pexadj[i] > 0)
          changed[nchanged++] = i;
      }

      /* Tell interested pe's the new where[] info for the interface vertices */
      CommChangedInterfaceData(ctrl, graph, nchanged, changed, where,
      swchanges, rwchanges, wspace->pv4); 


      IFSET(ctrl->dbglvl, DBG_RMOVEINFO,
      rprintf(ctrl, "\t[%d %d], [%.4f],  [%d %d %d]\n",
      pass, c, badmaxpwgt[0],
      GlobalSESum(ctrl, nmoves),
      GlobalSESum(ctrl, nsupd),
      GlobalSESum(ctrl, nlupd)));

      /*-------------------------------------------------------------
      / Time to communicate with processors to send the vertices
      / whose degrees need to be update.
      /-------------------------------------------------------------*/
      /* Issue the receives first */
      for (i=0; i<nnbrs; i++) {
        MPI_Irecv((void *)(rupdate+sendptr[i]), sendptr[i+1]-sendptr[i], IDX_DATATYPE,
                  peind[i], 1, ctrl->comm, ctrl->rreq+i);
      }

      /* Issue the sends next. This needs some preporcessing */
      for (i=0; i<nsupd; i++) {
        htable[supdate[i]] = 0;
        supdate[i] = graph->imap[supdate[i]];
      }
      iidxsort(nsupd, supdate);

      for (j=i=0; i<nnbrs; i++) {
        yourlastvtx = vtxdist[peind[i]+1];
        for (k=j; k<nsupd && supdate[k] < yourlastvtx; k++); 
        MPI_Isend((void *)(supdate+j), k-j, IDX_DATATYPE, peind[i], 1, ctrl->comm, ctrl->sreq+i);
        j = k;
      }

      /* OK, now get into the loop waiting for the send/recv operations to finish */
      MPI_Waitall(nnbrs, ctrl->rreq, ctrl->statuses);
      for (i=0; i<nnbrs; i++) 
        MPI_Get_count(ctrl->statuses+i, IDX_DATATYPE, nupds_pe+i);
      MPI_Waitall(nnbrs, ctrl->sreq, ctrl->statuses);


      /*-------------------------------------------------------------
      / Place the recieved to-be updated vertices into update[] 
      /-------------------------------------------------------------*/
      for (i=0; i<nnbrs; i++) {
        pe_updates = rupdate+sendptr[i];
        for (j=0; j<nupds_pe[i]; j++) {
          k = pe_updates[j];
          if (htable[k-firstvtx] == 0) {
            htable[k-firstvtx] = 1;
            update[nlupd++] = k-firstvtx;
          }
        }
      }


      /*-------------------------------------------------------------
      / Update the rinfo of the vertices in the update[] array
      /-------------------------------------------------------------*/
      for (ii=0; ii<nlupd; ii++) {
        i = update[ii];
        ASSERT(ctrl, htable[i] == 1);

        htable[i] = 0;

        mydomain = where[i];
        myrinfo = rinfo+i;
        tmp_myrinfo = tmp_rinfo+i;
        my_edegrees = myrinfo->degrees;
        your_edegrees = tmp_myrinfo->degrees;

        graph->lmincut -= myrinfo->ed;
        myrinfo->ndegrees = 0;
        myrinfo->id = 0;
        myrinfo->ed = 0;

        for (j=xadj[i]; j<xadj[i+1]; j++) {
          yourdomain = where[ladjncy[j]];
          if (mydomain != yourdomain) {
            myrinfo->ed += adjwgt[j];

            for (k=0; k<myrinfo->ndegrees; k++) {
              if (my_edegrees[k].edge == yourdomain) {
                my_edegrees[k].ewgt += adjwgt[j];
                your_edegrees[k].ewgt += adjwgt[j];
                break;
              }
            }
            if (k == myrinfo->ndegrees) {
              my_edegrees[k].edge = yourdomain;
              my_edegrees[k].ewgt = adjwgt[j];
              your_edegrees[k].edge = yourdomain;
              your_edegrees[k].ewgt = adjwgt[j];
              myrinfo->ndegrees++;
            }
            ASSERT(ctrl, myrinfo->ndegrees <= xadj[i+1]-xadj[i]);
            ASSERT(ctrl, tmp_myrinfo->ndegrees <= xadj[i+1]-xadj[i]);

          }
          else {
            myrinfo->id += adjwgt[j];
          }
        }
        graph->lmincut += myrinfo->ed;

        tmp_myrinfo->id = myrinfo->id;
        tmp_myrinfo->ed = myrinfo->ed;
        tmp_myrinfo->ndegrees = myrinfo->ndegrees;
      }

      /* finally, sum-up the partition weights */
      MPI_Allreduce((void *)lnpwgts, (void *)gnpwgts, nparts*ncon,
      MPI_DOUBLE, MPI_SUM, ctrl->comm);
    }
    graph->mincut = GlobalSESum(ctrl, graph->lmincut)/2;

    if (graph->mincut == oldcut)
      break;
  }

/*
  gnswaps = GlobalSESum(ctrl, nswaps);
  gnzgswaps = GlobalSESum(ctrl, nzgswaps);
  if (mype == 0)
    printf("niters: %d, nswaps: %d, nzgswaps: %d\n", pass+1, gnswaps, gnzgswaps);
*/

  GKfree((void **)&badmaxpwgt, (void **)&update, (void **)&nupds_pe, (void **)&htable, LTERM);
  GKfree((void **)&changed, (void **)&pperm, (void **)&perm, (void **)&moved, LTERM);
  GKfree((void **)&pgnpwgts, (void **)&ognpwgts, (void **)&overfill, (void **)&movewgts, LTERM);
  GKfree((void **)&tmp_where, (void **)&tmp_rinfo, (void **)&tmp_edegrees, LTERM);

  IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->KWayTmr));
}
Beispiel #2
0
/*************************************************************************
* This function performs k-way refinement
**************************************************************************/
void MCRandom_KWayEdgeRefineHorizontal(CtrlType *ctrl, GraphType *graph, int nparts, 
       float *orgubvec, int npasses)
{
  int i, ii, iii, j, /*jj,*/ k, /*l,*/ pass, nvtxs, ncon, nmoves, nbnd, myndegrees, same; 
  int from, me, to, oldcut, gain;
  idxtype *xadj, *adjncy, *adjwgt;
  idxtype *where, *perm, *bndptr, *bndind;
  EDegreeType *myedegrees;
  RInfoType *myrinfo;
  float *npwgts, *nvwgt, *minwgt, *maxwgt, maxlb, minlb, ubvec[MAXNCON], tvec[MAXNCON];

  nvtxs = graph->nvtxs;
  ncon = graph->ncon;
  xadj = graph->xadj;
  adjncy = graph->adjncy;
  adjwgt = graph->adjwgt;

  bndptr = graph->bndptr;
  bndind = graph->bndind;

  where = graph->where;
  npwgts = graph->npwgts;
  
  /* Setup the weight intervals of the various subdomains */
  minwgt =  fwspacemalloc(ctrl, nparts*ncon);
  maxwgt = fwspacemalloc(ctrl, nparts*ncon);

  /* See if the orgubvec consists of identical constraints */
  maxlb = minlb = orgubvec[0];
  for (i=1; i<ncon; i++) {
    minlb = (orgubvec[i] < minlb ? orgubvec[i] : minlb);
    maxlb = (orgubvec[i] > maxlb ? orgubvec[i] : maxlb);
  }
  same = (fabs(maxlb-minlb) < .01 ? 1 : 0);


  /* Let's not get very optimistic. Let Balancing do the work */
  ComputeHKWayLoadImbalance(ncon, nparts, npwgts, ubvec);
  for (i=0; i<ncon; i++)
    ubvec[i] = amax(ubvec[i], orgubvec[i]);

  if (!same) {
    for (i=0; i<nparts; i++) {
      for (j=0; j<ncon; j++) {
        maxwgt[i*ncon+j] = ubvec[j]/nparts;
        minwgt[i*ncon+j] = 1.0/(ubvec[j]*nparts);
      }
    }
  }
  else {
    maxlb = ubvec[0];
    for (i=1; i<ncon; i++) 
      maxlb = (ubvec[i] > maxlb ? ubvec[i] : maxlb);

    for (i=0; i<nparts; i++) {
      for (j=0; j<ncon; j++) {
        maxwgt[i*ncon+j] = maxlb/nparts;
        minwgt[i*ncon+j] = 1.0/(maxlb*nparts);
      }
    }
  }


  perm = idxwspacemalloc(ctrl, nvtxs);

  if (ctrl->dbglvl&DBG_REFINE) {
    printf("Partitions: [%5.4f %5.4f], Nv-Nb[%6d %6d]. Cut: %6d, LB: ",
            npwgts[samin(ncon*nparts, npwgts)], npwgts[samax(ncon*nparts, npwgts)], 
            graph->nvtxs, graph->nbnd, graph->mincut);
    ComputeHKWayLoadImbalance(ncon, nparts, npwgts, tvec);
    for (i=0; i<ncon; i++)
      printf("%.3f ", tvec[i]);
    printf("\n");
  }

  for (pass=0; pass<npasses; pass++) {
    ASSERT(ComputeCut(graph, where) == graph->mincut);

    oldcut = graph->mincut;
    nbnd = graph->nbnd;

    RandomPermute(nbnd, perm, 1);
    for (nmoves=iii=0; iii<graph->nbnd; iii++) {
      ii = perm[iii];
      if (ii >= nbnd)
        continue;
      i = bndind[ii];

      myrinfo = graph->rinfo+i;

      if (myrinfo->ed >= myrinfo->id) { /* Total ED is too high */
        from = where[i];
        nvwgt = graph->nvwgt+i*ncon;

        if (myrinfo->id > 0 && AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, -1.0, nvwgt, minwgt+from*ncon)) 
          continue;   /* This cannot be moved! */

        myedegrees = myrinfo->edegrees;
        myndegrees = myrinfo->ndegrees;

        for (k=0; k<myndegrees; k++) {
          to = myedegrees[k].pid;
          gain = myedegrees[k].ed - myrinfo->id; 
          if (gain >= 0 && 
              (AreAllHVwgtsBelow(ncon, 1.0, npwgts+to*ncon, 1.0, nvwgt, maxwgt+to*ncon) ||
               IsHBalanceBetterFT(ncon, nparts, npwgts+from*ncon, npwgts+to*ncon, nvwgt, ubvec)))
            break;
        }
        if (k == myndegrees)
          continue;  /* break out if you did not find a candidate */

        for (j=k+1; j<myndegrees; j++) {
          to = myedegrees[j].pid;
          if ((myedegrees[j].ed > myedegrees[k].ed &&
               (AreAllHVwgtsBelow(ncon, 1.0, npwgts+to*ncon, 1.0, nvwgt, maxwgt+to*ncon) || 
               IsHBalanceBetterFT(ncon, nparts, npwgts+from*ncon, npwgts+to*ncon, nvwgt, ubvec))) ||
              (myedegrees[j].ed == myedegrees[k].ed && 
               IsHBalanceBetterTT(ncon, nparts, npwgts+myedegrees[k].pid*ncon, npwgts+to*ncon, nvwgt, ubvec)))
            k = j;
        }

        to = myedegrees[k].pid;

        if (myedegrees[k].ed-myrinfo->id == 0 
            && !IsHBalanceBetterFT(ncon, nparts, npwgts+from*ncon, npwgts+to*ncon, nvwgt, ubvec)
            && AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, 0.0, npwgts+from*ncon, maxwgt+from*ncon)) 
          continue;

        /*=====================================================================
        * If we got here, we can now move the vertex from 'from' to 'to' 
        *======================================================================*/
        graph->mincut -= myedegrees[k].ed-myrinfo->id;

        IFSET(ctrl->dbglvl, DBG_MOVEINFO, printf("\t\tMoving %6d to %3d. Gain: %4d. Cut: %6d\n", i, to, myedegrees[k].ed-myrinfo->id, graph->mincut));

        /* Update where, weight, and ID/ED information of the vertex you moved */
        saxpy(ncon, 1.0, nvwgt, 1, npwgts+to*ncon, 1);
        saxpy(ncon, -1.0, nvwgt, 1, npwgts+from*ncon, 1);
        where[i] = to;
        myrinfo->ed += myrinfo->id-myedegrees[k].ed;
        SWAP(myrinfo->id, myedegrees[k].ed, j);
        if (myedegrees[k].ed == 0) 
          myedegrees[k] = myedegrees[--myrinfo->ndegrees];
        else
          myedegrees[k].pid = from;

        if (myrinfo->ed-myrinfo->id < 0)
          BNDDelete(nbnd, bndind, bndptr, i);

        /* Update the degrees of adjacent vertices */
        for (j=xadj[i]; j<xadj[i+1]; j++) {
          ii = adjncy[j];
          me = where[ii];

          myrinfo = graph->rinfo+ii;
          if (myrinfo->edegrees == NULL) {
            myrinfo->edegrees = ctrl->wspace.edegrees+ctrl->wspace.cdegree;
            ctrl->wspace.cdegree += xadj[ii+1]-xadj[ii];
          }
          myedegrees = myrinfo->edegrees;

          ASSERT(CheckRInfo(myrinfo));

          if (me == from) {
            INC_DEC(myrinfo->ed, myrinfo->id, adjwgt[j]);

            if (myrinfo->ed-myrinfo->id >= 0 && bndptr[ii] == -1)
              BNDInsert(nbnd, bndind, bndptr, ii);
          }
          else if (me == to) {
            INC_DEC(myrinfo->id, myrinfo->ed, adjwgt[j]);

            if (myrinfo->ed-myrinfo->id < 0 && bndptr[ii] != -1)
              BNDDelete(nbnd, bndind, bndptr, ii);
          }

          /* Remove contribution from the .ed of 'from' */
          if (me != from) {
            for (k=0; k<myrinfo->ndegrees; k++) {
              if (myedegrees[k].pid == from) {
                if (myedegrees[k].ed == adjwgt[j])
                  myedegrees[k] = myedegrees[--myrinfo->ndegrees];
                else
                  myedegrees[k].ed -= adjwgt[j];
                break;
              }
            }
          }

          /* Add contribution to the .ed of 'to' */
          if (me != to) {
            for (k=0; k<myrinfo->ndegrees; k++) {
              if (myedegrees[k].pid == to) {
                myedegrees[k].ed += adjwgt[j];
                break;
              }
            }
            if (k == myrinfo->ndegrees) {
              myedegrees[myrinfo->ndegrees].pid = to;
              myedegrees[myrinfo->ndegrees++].ed = adjwgt[j];
            }
          }

          ASSERT(myrinfo->ndegrees <= xadj[ii+1]-xadj[ii]);
          ASSERT(CheckRInfo(myrinfo));

        }
        nmoves++;
      }
    }

    graph->nbnd = nbnd;

    if (ctrl->dbglvl&DBG_REFINE) {
      printf("\t [%5.4f %5.4f], Nb: %6d, Nmoves: %5d, Cut: %6d, LB: ",
              npwgts[samin(ncon*nparts, npwgts)], npwgts[samax(ncon*nparts, npwgts)], 
              nbnd, nmoves, graph->mincut);
      ComputeHKWayLoadImbalance(ncon, nparts, npwgts, tvec);
      for (i=0; i<ncon; i++)
        printf("%.3f ", tvec[i]);
      printf("\n");
    }

    if (graph->mincut == oldcut)
      break;
  }

  fwspacefree(ctrl, ncon*nparts);
  fwspacefree(ctrl, ncon*nparts);
  idxwspacefree(ctrl, nvtxs);
}
Beispiel #3
0
/*************************************************************************
* This function performs k-way refinement
**************************************************************************/
void MCGreedy_KWayEdgeBalanceHorizontal(CtrlType *ctrl, GraphType *graph, int nparts, 
       float *ubvec, int npasses)
{
  int i, ii, /*iii,*/ j, /*jj,*/ k, /*l,*/ pass, nvtxs, ncon, nbnd, myndegrees, oldgain, gain, nmoves; 
  int from, me, to, oldcut;
  idxtype *xadj, *adjncy, *adjwgt;
  idxtype *where, *perm, *bndptr, *bndind, *moved;
  EDegreeType *myedegrees;
  RInfoType *myrinfo;
  PQueueType queue;
  float *npwgts, *nvwgt, *minwgt, *maxwgt, tvec[MAXNCON];

  nvtxs = graph->nvtxs;
  ncon = graph->ncon;
  xadj = graph->xadj;
  adjncy = graph->adjncy;
  adjwgt = graph->adjwgt;

  bndind = graph->bndind;
  bndptr = graph->bndptr;

  where = graph->where;
  npwgts = graph->npwgts;
  
  /* Setup the weight intervals of the various subdomains */
  minwgt =  fwspacemalloc(ctrl, ncon*nparts);
  maxwgt = fwspacemalloc(ctrl, ncon*nparts);

  for (i=0; i<nparts; i++) {
    for (j=0; j<ncon; j++) {
      maxwgt[i*ncon+j] = ubvec[j]/nparts;
      minwgt[i*ncon+j] = 1.0/(ubvec[j]*nparts);
    }
  }

  perm = idxwspacemalloc(ctrl, nvtxs);
  moved = idxwspacemalloc(ctrl, nvtxs);

  PQueueInit(ctrl, &queue, nvtxs, graph->adjwgtsum[idxamax(nvtxs, graph->adjwgtsum)]);

  if (ctrl->dbglvl&DBG_REFINE) {
    printf("Partitions: [%5.4f %5.4f], Nv-Nb[%6d %6d]. Cut: %6d, LB: ",
            npwgts[samin(ncon*nparts, npwgts)], npwgts[samax(ncon*nparts, npwgts)], 
            graph->nvtxs, graph->nbnd, graph->mincut);
    ComputeHKWayLoadImbalance(ncon, nparts, npwgts, tvec);
    for (i=0; i<ncon; i++)
      printf("%.3f ", tvec[i]);
    printf("[B]\n");
  }


  for (pass=0; pass<npasses; pass++) {
    ASSERT(ComputeCut(graph, where) == graph->mincut);

    /* Check to see if things are out of balance, given the tolerance */
    if (MocIsHBalanced(ncon, nparts, npwgts, ubvec))
      break;

    PQueueReset(&queue);
    idxset(nvtxs, -1, moved);

    oldcut = graph->mincut;
    nbnd = graph->nbnd;

    RandomPermute(nbnd, perm, 1);
    for (ii=0; ii<nbnd; ii++) {
      i = bndind[perm[ii]];
      PQueueInsert(&queue, i, graph->rinfo[i].ed - graph->rinfo[i].id);
      moved[i] = 2;
    }

    nmoves = 0;
    for (;;) {
      if ((i = PQueueGetMax(&queue)) == -1) 
        break;
      moved[i] = 1;

      myrinfo = graph->rinfo+i;
      from = where[i];
      nvwgt = graph->nvwgt+i*ncon;

      if (AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, -1.0, nvwgt, minwgt+from*ncon))
        continue;   /* This cannot be moved! */

      myedegrees = myrinfo->edegrees;
      myndegrees = myrinfo->ndegrees;

      for (k=0; k<myndegrees; k++) {
        to = myedegrees[k].pid;
        if (IsHBalanceBetterFT(ncon, nparts, npwgts+from*ncon, npwgts+to*ncon, nvwgt, ubvec))
          break;
      }
      if (k == myndegrees) 
        continue;  /* break out if you did not find a candidate */

      for (j=k+1; j<myndegrees; j++) {
        to = myedegrees[j].pid;
        if (IsHBalanceBetterTT(ncon, nparts, npwgts+myedegrees[k].pid*ncon, npwgts+to*ncon, nvwgt, ubvec)) 
          k = j;
      }

      to = myedegrees[k].pid;

      j = 0;
      if (!AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, 0.0, nvwgt, maxwgt+from*ncon))
        j++;
      if (myedegrees[k].ed-myrinfo->id >= 0)
        j++;
      if (!AreAllHVwgtsAbove(ncon, 1.0, npwgts+to*ncon, 0.0, nvwgt, minwgt+to*ncon) &&
          AreAllHVwgtsBelow(ncon, 1.0, npwgts+to*ncon, 1.0, nvwgt, maxwgt+to*ncon))
        j++;
      if (j == 0)
        continue;

/* DELETE
      if (myedegrees[k].ed-myrinfo->id < 0 && 
          AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, 0.0, nvwgt, maxwgt+from*ncon) &&
          AreAllHVwgtsAbove(ncon, 1.0, npwgts+to*ncon, 0.0, nvwgt, minwgt+to*ncon) &&
          AreAllHVwgtsBelow(ncon, 1.0, npwgts+to*ncon, 1.0, nvwgt, maxwgt+to*ncon))
        continue;
*/
      /*=====================================================================
      * If we got here, we can now move the vertex from 'from' to 'to' 
      *======================================================================*/
      graph->mincut -= myedegrees[k].ed-myrinfo->id;

      IFSET(ctrl->dbglvl, DBG_MOVEINFO, printf("\t\tMoving %6d to %3d. Gain: %4d. Cut: %6d\n", i, to, myedegrees[k].ed-myrinfo->id, graph->mincut));

      /* Update where, weight, and ID/ED information of the vertex you moved */
      saxpy(ncon, 1.0, nvwgt, 1, npwgts+to*ncon, 1);
      saxpy(ncon, -1.0, nvwgt, 1, npwgts+from*ncon, 1);
      where[i] = to;
      myrinfo->ed += myrinfo->id-myedegrees[k].ed;
      SWAP(myrinfo->id, myedegrees[k].ed, j);
      if (myedegrees[k].ed == 0) 
        myedegrees[k] = myedegrees[--myrinfo->ndegrees];
      else
        myedegrees[k].pid = from;

      if (myrinfo->ed == 0)
        BNDDelete(nbnd, bndind, bndptr, i);

      /* Update the degrees of adjacent vertices */
      for (j=xadj[i]; j<xadj[i+1]; j++) {
        ii = adjncy[j];
        me = where[ii];

        myrinfo = graph->rinfo+ii;
        if (myrinfo->edegrees == NULL) {
          myrinfo->edegrees = ctrl->wspace.edegrees+ctrl->wspace.cdegree;
          ctrl->wspace.cdegree += xadj[ii+1]-xadj[ii];
        }
        myedegrees = myrinfo->edegrees;

        ASSERT(CheckRInfo(myrinfo));

        oldgain = (myrinfo->ed-myrinfo->id);

        if (me == from) {
          INC_DEC(myrinfo->ed, myrinfo->id, adjwgt[j]);

          if (myrinfo->ed > 0 && bndptr[ii] == -1)
            BNDInsert(nbnd, bndind, bndptr, ii);
        }
        else if (me == to) {
          INC_DEC(myrinfo->id, myrinfo->ed, adjwgt[j]);

          if (myrinfo->ed == 0 && bndptr[ii] != -1)
            BNDDelete(nbnd, bndind, bndptr, ii);
        }

        /* Remove contribution from the .ed of 'from' */
        if (me != from) {
          for (k=0; k<myrinfo->ndegrees; k++) {
            if (myedegrees[k].pid == from) {
              if (myedegrees[k].ed == adjwgt[j])
                myedegrees[k] = myedegrees[--myrinfo->ndegrees];
              else
                myedegrees[k].ed -= adjwgt[j];
              break;
            }
          }
        }

        /* Add contribution to the .ed of 'to' */
        if (me != to) {
          for (k=0; k<myrinfo->ndegrees; k++) {
            if (myedegrees[k].pid == to) {
              myedegrees[k].ed += adjwgt[j];
              break;
            }
          }
          if (k == myrinfo->ndegrees) {
            myedegrees[myrinfo->ndegrees].pid = to;
            myedegrees[myrinfo->ndegrees++].ed = adjwgt[j];
          }
        }


        /* Update the queue */
        if (me == to || me == from) { 
          gain = myrinfo->ed-myrinfo->id;
          if (moved[ii] == 2) {
            if (myrinfo->ed > 0)
              PQueueUpdate(&queue, ii, oldgain, gain);
            else {
              PQueueDelete(&queue, ii, oldgain);
              moved[ii] = -1;
            }
          }
          else if (moved[ii] == -1 && myrinfo->ed > 0) {
            PQueueInsert(&queue, ii, gain);
            moved[ii] = 2;
          }
        } 

        ASSERT(myrinfo->ndegrees <= xadj[ii+1]-xadj[ii]);
        ASSERT(CheckRInfo(myrinfo));
      }
      nmoves++;
    }

    graph->nbnd = nbnd;

    if (ctrl->dbglvl&DBG_REFINE) {
      printf("\t [%5.4f %5.4f], Nb: %6d, Nmoves: %5d, Cut: %6d, LB: ",
              npwgts[samin(ncon*nparts, npwgts)], npwgts[samax(ncon*nparts, npwgts)], 
              nbnd, nmoves, graph->mincut);
      ComputeHKWayLoadImbalance(ncon, nparts, npwgts, tvec);
      for (i=0; i<ncon; i++)
        printf("%.3f ", tvec[i]);
      printf("\n");
    }

    if (nmoves == 0)
      break;
  }

  PQueueFree(ctrl, &queue);

  fwspacefree(ctrl, ncon*nparts);
  fwspacefree(ctrl, ncon*nparts);
  idxwspacefree(ctrl, nvtxs);
  idxwspacefree(ctrl, nvtxs);

}
Beispiel #4
0
/*************************************************************************
* This function performs k-way refinement
**************************************************************************/
void Mc_SerialKWayAdaptRefine(GraphType *graph, int nparts, idxtype *home,
     float *orgubvec, int npasses)
{
  int i, ii, iii, j, k;
  int nvtxs, ncon, pass, nmoves, myndegrees;
  int from, me, myhome, to, oldcut, gain, tmp;
  idxtype *xadj, *adjncy, *adjwgt;
  idxtype *where;
  EdgeType *mydegrees;
  RInfoType *rinfo, *myrinfo;
  float *npwgts, *nvwgt, *minwgt, *maxwgt, ubvec[MAXNCON];
  int gain_is_greater, gain_is_same, fit_in_to, fit_in_from, going_home;
  int zero_gain, better_balance_ft, better_balance_tt;
  KeyValueType *cand;
int mype;
MPI_Comm_rank(MPI_COMM_WORLD, &mype);

  nvtxs = graph->nvtxs;
  ncon = graph->ncon;
  xadj = graph->xadj;
  adjncy = graph->adjncy;
  adjwgt = graph->adjwgt;
  where = graph->where;
  rinfo = graph->rinfo;
  npwgts = graph->gnpwgts;
  
  /* Setup the weight intervals of the various subdomains */
  cand = (KeyValueType *)GKmalloc(nvtxs*sizeof(KeyValueType), "cand");
  minwgt =  fmalloc(nparts*ncon, "minwgt");
  maxwgt = fmalloc(nparts*ncon, "maxwgt");

  ComputeHKWayLoadImbalance(ncon, nparts, npwgts, ubvec);
  for (i=0; i<ncon; i++)
    ubvec[i] = amax(ubvec[i], orgubvec[i]);

  for (i=0; i<nparts; i++) {
    for (j=0; j<ncon; j++) {
      maxwgt[i*ncon+j] = ubvec[j]/(float)nparts;
      minwgt[i*ncon+j] = ubvec[j]*(float)nparts;
    }
  }

  for (pass=0; pass<npasses; pass++) {
    oldcut = graph->mincut;

    for (i=0; i<nvtxs; i++) {
      cand[i].key = rinfo[i].id-rinfo[i].ed;
      cand[i].val = i;
    }
    ikeysort(nvtxs, cand);

    nmoves = 0;
    for (iii=0; iii<nvtxs; iii++) {
      i = cand[iii].val;

      myrinfo = rinfo+i;

      if (myrinfo->ed >= myrinfo->id) {
        from = where[i];
        myhome = home[i];
        nvwgt = graph->nvwgt+i*ncon;

        if (myrinfo->id > 0 &&
        AreAllHVwgtsBelow(ncon, 1.0, npwgts+from*ncon, -1.0, nvwgt, minwgt+from*ncon)) 
          continue;

        mydegrees = myrinfo->degrees;
        myndegrees = myrinfo->ndegrees;

        for (k=0; k<myndegrees; k++) {
          to = mydegrees[k].edge;
          gain = mydegrees[k].ewgt - myrinfo->id; 
          if (gain >= 0 && 
             (AreAllHVwgtsBelow(ncon, 1.0, npwgts+to*ncon, 1.0, nvwgt, maxwgt+to*ncon) ||
             IsHBalanceBetterFT(ncon,npwgts+from*ncon,npwgts+to*ncon,nvwgt,ubvec))) {
            break;
          }
        }

        /* break out if you did not find a candidate */
        if (k == myndegrees)
          continue;

        for (j=k+1; j<myndegrees; j++) {
          to = mydegrees[j].edge;
          going_home = (myhome == to);
          gain_is_same = (mydegrees[j].ewgt == mydegrees[k].ewgt);
          gain_is_greater = (mydegrees[j].ewgt > mydegrees[k].ewgt);
          fit_in_to = AreAllHVwgtsBelow(ncon,1.0,npwgts+to*ncon,1.0,nvwgt,maxwgt+to*ncon);
          better_balance_ft = IsHBalanceBetterFT(ncon,npwgts+from*ncon,
                              npwgts+to*ncon,nvwgt,ubvec);
          better_balance_tt = IsHBalanceBetterTT(ncon,npwgts+mydegrees[k].edge*ncon,
                              npwgts+to*ncon,nvwgt,ubvec);

          if (
               (gain_is_greater &&
                 (fit_in_to ||
                  better_balance_ft)
               )
            ||
               (gain_is_same &&
                 (
                   (fit_in_to &&
                    going_home)
                ||
                    better_balance_tt
                 )
               )
             ) {
            k = j;
          }
        }

        to = mydegrees[k].edge;
        going_home = (myhome == to);
        zero_gain = (mydegrees[k].ewgt == myrinfo->id);

        fit_in_from = AreAllHVwgtsBelow(ncon,1.0,npwgts+from*ncon,0.0,npwgts+from*ncon,
                      maxwgt+from*ncon);
        better_balance_ft = IsHBalanceBetterFT(ncon,npwgts+from*ncon,
                            npwgts+to*ncon,nvwgt,ubvec);

        if (zero_gain &&
            !going_home &&
            !better_balance_ft &&
            fit_in_from)
          continue;

        /*=====================================================================
        * If we got here, we can now move the vertex from 'from' to 'to' 
        *======================================================================*/
        graph->mincut -= mydegrees[k].ewgt-myrinfo->id;

        /* Update where, weight, and ID/ED information of the vertex you moved */
        saxpy2(ncon, 1.0, nvwgt, 1, npwgts+to*ncon, 1);
        saxpy2(ncon, -1.0, nvwgt, 1, npwgts+from*ncon, 1);
        where[i] = to;
        myrinfo->ed += myrinfo->id-mydegrees[k].ewgt;
        SWAP(myrinfo->id, mydegrees[k].ewgt, tmp);

        if (mydegrees[k].ewgt == 0) {
          myrinfo->ndegrees--;
          mydegrees[k].edge = mydegrees[myrinfo->ndegrees].edge;
          mydegrees[k].ewgt = mydegrees[myrinfo->ndegrees].ewgt;
        }
        else
          mydegrees[k].edge = from;

        /* Update the degrees of adjacent vertices */
        for (j=xadj[i]; j<xadj[i+1]; j++) {
          ii = adjncy[j];
          me = where[ii];

          myrinfo = rinfo+ii;
          mydegrees = myrinfo->degrees;

          if (me == from) {
            INC_DEC(myrinfo->ed, myrinfo->id, adjwgt[j]);
          }
          else {
            if (me == to) {
              INC_DEC(myrinfo->id, myrinfo->ed, adjwgt[j]);
            }
          }

          /* Remove contribution of the ed from 'from' */
          if (me != from) {
            for (k=0; k<myrinfo->ndegrees; k++) {
              if (mydegrees[k].edge == from) {
                if (mydegrees[k].ewgt == adjwgt[j]) {
                  myrinfo->ndegrees--;
                  mydegrees[k].edge = mydegrees[myrinfo->ndegrees].edge;
                  mydegrees[k].ewgt = mydegrees[myrinfo->ndegrees].ewgt;
                }
                else
                  mydegrees[k].ewgt -= adjwgt[j];
                break;
              }
            }
          }

          /* Add contribution of the ed to 'to' */
          if (me != to) {
            for (k=0; k<myrinfo->ndegrees; k++) {
              if (mydegrees[k].edge == to) {
                mydegrees[k].ewgt += adjwgt[j];
                break;
              }
            }
            if (k == myrinfo->ndegrees) {
              mydegrees[myrinfo->ndegrees].edge = to;
              mydegrees[myrinfo->ndegrees++].ewgt = adjwgt[j];
            }
          }

        }
        nmoves++;
      }
    }

    if (graph->mincut == oldcut)
      break;
  }

  GKfree((void **)&minwgt, (void **)&maxwgt, (void **)&cand, LTERM);

  return;
}