Date: 2025-03-29T05:58:33+00:00

Actual source code: baijov.c

      1: /*
      2:    Routines to compute overlapping regions of a parallel MPI matrix
      3:   and to find submatrices that were shared across processors.
      4: */
      5: #include <../src/mat/impls/baij/mpi/mpibaij.h>
      6: #include <petscbt.h>

      8: static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat, PetscInt, char **, PetscInt *, PetscInt **);
      9: static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat, PetscInt, PetscInt **, PetscInt **, PetscInt *);
     10: extern PetscErrorCode MatGetRow_MPIBAIJ(Mat, PetscInt, PetscInt *, PetscInt **, PetscScalar **);
     11: extern PetscErrorCode MatRestoreRow_MPIBAIJ(Mat, PetscInt, PetscInt *, PetscInt **, PetscScalar **);

     13: PetscErrorCode MatIncreaseOverlap_MPIBAIJ(Mat C, PetscInt imax, IS is[], PetscInt ov)
     14: {
     15:   PetscInt        i, N = C->cmap->N, bs = C->rmap->bs, n;
     16:   const PetscInt *idx;
     17:   IS             *is_new;

     19:   PetscFunctionBegin;
     20:   PetscCall(PetscMalloc1(imax, &is_new));
     21:   /* Convert the indices into block format */
     22:   PetscCall(ISCompressIndicesGeneral(N, C->rmap->n, bs, imax, is, is_new));
     23:   PetscCheck(ov >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative overlap specified");
     24:   for (i = 0; i < ov; ++i) PetscCall(MatIncreaseOverlap_MPIBAIJ_Once(C, imax, is_new));
     25:   for (i = 0; i < imax; i++) {
     26:     PetscCall(ISDestroy(&is[i]));
     27:     PetscCall(ISGetLocalSize(is_new[i], &n));
     28:     PetscCall(ISGetIndices(is_new[i], &idx));
     29:     PetscCall(ISCreateBlock(PetscObjectComm((PetscObject)is_new[i]), bs, n, idx, PETSC_COPY_VALUES, &is[i]));
     30:     PetscCall(ISDestroy(&is_new[i]));
     31:   }
     32:   PetscCall(PetscFree(is_new));
     33:   PetscFunctionReturn(PETSC_SUCCESS);
     34: }

     36: /*
     37:   Sample message format:
     38:   If a processor A wants processor B to process some elements corresponding
     39:   to index sets is[1], is[5]
     40:   mesg [0] = 2   (no of index sets in the mesg)
     41:   -----------
     42:   mesg [1] = 1 => is[1]
     43:   mesg [2] = sizeof(is[1]);
     44:   -----------
     45:   mesg [5] = 5  => is[5]
     46:   mesg [6] = sizeof(is[5]);
     47:   -----------
     48:   mesg [7]
     49:   mesg [n]  data(is[1])
     50:   -----------
     51:   mesg[n+1]
     52:   mesg[m]  data(is[5])
     53:   -----------

     55:   Notes:
     56:   nrqs - no of requests sent (or to be sent out)
     57:   nrqr - no of requests received (which have to be or which have been processed)
     58: */
     59: PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Once(Mat C, PetscInt imax, IS is[])
     60: {
     61:   Mat_MPIBAIJ     *c = (Mat_MPIBAIJ *)C->data;
     62:   const PetscInt **idx, *idx_i;
     63:   PetscInt        *n, *w3, *w4, **data, len;
     64:   PetscMPIInt      size, rank, tag1, tag2, *w2, *w1, nrqs, nrqr, *pa;
     65:   PetscInt         Mbs, **rbuf, row, msz, **outdat, **ptr;
     66:   PetscInt        *ctr, *tmp, *isz, *isz1, **xdata, **rbuf2, *d_p;
     67:   PetscMPIInt     *onodes1, *olengths1, *onodes2, *olengths2, proc = -1;
     68:   PetscBT         *table;
     69:   MPI_Comm         comm, *iscomms;
     70:   MPI_Request     *s_waits1, *r_waits1, *s_waits2, *r_waits2;
     71:   char            *t_p;

     73:   PetscFunctionBegin;
     74:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
     75:   size = c->size;
     76:   rank = c->rank;
     77:   Mbs  = c->Mbs;

     79:   PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag1));
     80:   PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag2));

     82:   PetscCall(PetscMalloc2(imax, (PetscInt ***)&idx, imax, &n));

     84:   for (PetscInt i = 0; i < imax; i++) {
     85:     PetscCall(ISGetIndices(is[i], &idx[i]));
     86:     PetscCall(ISGetLocalSize(is[i], &n[i]));
     87:   }

     89:   /* evaluate communication - mesg to who,length of mesg, and buffer space
     90:      required. Based on this, buffers are allocated, and data copied into them*/
     91:   PetscCall(PetscCalloc4(size, &w1, size, &w2, size, &w3, size, &w4));
     92:   for (PetscInt i = 0; i < imax; i++) {
     93:     PetscCall(PetscArrayzero(w4, size)); /* initialise work vector*/
     94:     idx_i = idx[i];
     95:     len   = n[i];
     96:     for (PetscInt j = 0; j < len; j++) {
     97:       row = idx_i[j];
     98:       PetscCheck(row >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Index set cannot have negative entries");
     99:       PetscCall(PetscLayoutFindOwner(C->rmap, row * C->rmap->bs, &proc));
    100:       w4[proc]++;
    101:     }
    102:     for (PetscMPIInt j = 0; j < size; j++) {
    103:       if (w4[j]) {
    104:         w1[j] += w4[j];
    105:         w3[j]++;
    106:       }
    107:     }
    108:   }

    110:   nrqs     = 0; /* no of outgoing messages */
    111:   msz      = 0; /* total mesg length (for all proc */
    112:   w1[rank] = 0; /* no mesg sent to itself */
    113:   w3[rank] = 0;
    114:   for (PetscMPIInt i = 0; i < size; i++) {
    115:     if (w1[i]) {
    116:       w2[i] = 1;
    117:       nrqs++;
    118:     } /* there exists a message to proc i */
    119:   }
    120:   /* pa - is list of processors to communicate with */
    121:   PetscCall(PetscMalloc1(nrqs, &pa));
    122:   for (PetscMPIInt i = 0, j = 0; i < size; i++) {
    123:     if (w1[i]) {
    124:       pa[j] = i;
    125:       j++;
    126:     }
    127:   }

    129:   /* Each message would have a header = 1 + 2*(no of IS) + data */
    130:   for (PetscMPIInt i = 0; i < nrqs; i++) {
    131:     PetscMPIInt j = pa[i];
    132:     w1[j] += w2[j] + 2 * w3[j];
    133:     msz += w1[j];
    134:   }

    136:   /* Determine the number of messages to expect, their lengths, from from-ids */
    137:   PetscCall(PetscGatherNumberOfMessages(comm, w2, w1, &nrqr));
    138:   PetscCall(PetscGatherMessageLengths(comm, nrqs, nrqr, w1, &onodes1, &olengths1));

    140:   /* Now post the Irecvs corresponding to these messages */
    141:   PetscCall(PetscPostIrecvInt(comm, tag1, nrqr, onodes1, olengths1, &rbuf, &r_waits1));

    143:   /* Allocate Memory for outgoing messages */
    144:   PetscCall(PetscMalloc4(size, &outdat, size, &ptr, msz, &tmp, size, &ctr));
    145:   PetscCall(PetscArrayzero(outdat, size));
    146:   PetscCall(PetscArrayzero(ptr, size));
    147:   {
    148:     PetscInt *iptr = tmp, ict = 0;
    149:     for (PetscMPIInt i = 0; i < nrqs; i++) {
    150:       PetscMPIInt j = pa[i];
    151:       iptr += ict;
    152:       outdat[j] = iptr;
    153:       ict       = w1[j];
    154:     }
    155:   }

    157:   /* Form the outgoing messages */
    158:   /*plug in the headers*/
    159:   for (PetscMPIInt i = 0; i < nrqs; i++) {
    160:     PetscMPIInt j = pa[i];
    161:     outdat[j][0]  = 0;
    162:     PetscCall(PetscArrayzero(outdat[j] + 1, 2 * w3[j]));
    163:     ptr[j] = outdat[j] + 2 * w3[j] + 1;
    164:   }

    166:   /* Memory for doing local proc's work*/
    167:   {
    168:     PetscCall(PetscCalloc5(imax, &table, imax, &data, imax, &isz, Mbs * imax, &d_p, (Mbs / PETSC_BITS_PER_BYTE + 1) * imax, &t_p));

    170:     for (PetscInt i = 0; i < imax; i++) {
    171:       table[i] = t_p + (Mbs / PETSC_BITS_PER_BYTE + 1) * i;
    172:       data[i]  = d_p + (Mbs)*i;
    173:     }
    174:   }

    176:   /* Parse the IS and update local tables and the outgoing buf with the data*/
    177:   {
    178:     PetscInt n_i, *data_i, isz_i, *outdat_j, ctr_j, k;
    179:     PetscBT  table_i;

    181:     for (PetscInt i = 0; i < imax; i++) {
    182:       PetscCall(PetscArrayzero(ctr, size));
    183:       n_i     = n[i];
    184:       table_i = table[i];
    185:       idx_i   = idx[i];
    186:       data_i  = data[i];
    187:       isz_i   = isz[i];
    188:       for (PetscInt j = 0; j < n_i; j++) { /* parse the indices of each IS */
    189:         row = idx_i[j];
    190:         PetscCall(PetscLayoutFindOwner(C->rmap, row * C->rmap->bs, &proc));
    191:         if (proc != rank) { /* copy to the outgoing buffer */
    192:           ctr[proc]++;
    193:           *ptr[proc] = row;
    194:           ptr[proc]++;
    195:         } else { /* Update the local table */
    196:           if (!PetscBTLookupSet(table_i, row)) data_i[isz_i++] = row;
    197:         }
    198:       }
    199:       /* Update the headers for the current IS */
    200:       for (PetscMPIInt j = 0; j < size; j++) { /* Can Optimise this loop by using pa[] */
    201:         if ((ctr_j = ctr[j])) {
    202:           outdat_j            = outdat[j];
    203:           k                   = ++outdat_j[0];
    204:           outdat_j[2 * k]     = ctr_j;
    205:           outdat_j[2 * k - 1] = i;
    206:         }
    207:       }
    208:       isz[i] = isz_i;
    209:     }
    210:   }

    212:   /*  Now  post the sends */
    213:   PetscCall(PetscMalloc1(nrqs, &s_waits1));
    214:   for (PetscMPIInt i = 0; i < nrqs; ++i) {
    215:     PetscMPIInt j = pa[i];
    216:     PetscCallMPI(MPIU_Isend(outdat[j], w1[j], MPIU_INT, j, tag1, comm, s_waits1 + i));
    217:   }

    219:   /* No longer need the original indices*/
    220:   for (PetscInt i = 0; i < imax; ++i) PetscCall(ISRestoreIndices(is[i], idx + i));
    221:   PetscCall(PetscFree2(*(PetscInt ***)&idx, n));

    223:   PetscCall(PetscMalloc1(imax, &iscomms));
    224:   for (PetscInt i = 0; i < imax; ++i) {
    225:     PetscCall(PetscCommDuplicate(PetscObjectComm((PetscObject)is[i]), &iscomms[i], NULL));
    226:     PetscCall(ISDestroy(&is[i]));
    227:   }

    229:   /* Do Local work*/
    230:   PetscCall(MatIncreaseOverlap_MPIBAIJ_Local(C, imax, table, isz, data));

    232:   /* Receive messages*/
    233:   PetscCallMPI(MPI_Waitall(nrqr, r_waits1, MPI_STATUSES_IGNORE));
    234:   PetscCallMPI(MPI_Waitall(nrqs, s_waits1, MPI_STATUSES_IGNORE));

    236:   /* Phase 1 sends are complete - deallocate buffers */
    237:   PetscCall(PetscFree4(outdat, ptr, tmp, ctr));
    238:   PetscCall(PetscFree4(w1, w2, w3, w4));

    240:   PetscCall(PetscMalloc1(nrqr, &xdata));
    241:   PetscCall(PetscMalloc1(nrqr, &isz1));
    242:   PetscCall(MatIncreaseOverlap_MPIBAIJ_Receive(C, nrqr, rbuf, xdata, isz1));
    243:   if (rbuf) {
    244:     PetscCall(PetscFree(rbuf[0]));
    245:     PetscCall(PetscFree(rbuf));
    246:   }

    248:   /* Send the data back*/
    249:   /* Do a global reduction to know the buffer space req for incoming messages*/
    250:   {
    251:     PetscMPIInt *rw1;

    253:     PetscCall(PetscCalloc1(size, &rw1));
    254:     for (PetscMPIInt i = 0; i < nrqr; ++i) {
    255:       proc = onodes1[i];
    256:       PetscCall(PetscMPIIntCast(isz1[i], &rw1[proc]));
    257:     }

    259:     /* Determine the number of messages to expect, their lengths, from from-ids */
    260:     PetscCall(PetscGatherMessageLengths(comm, nrqr, nrqs, rw1, &onodes2, &olengths2));
    261:     PetscCall(PetscFree(rw1));
    262:   }
    263:   /* Now post the Irecvs corresponding to these messages */
    264:   PetscCall(PetscPostIrecvInt(comm, tag2, nrqs, onodes2, olengths2, &rbuf2, &r_waits2));

    266:   /*  Now  post the sends */
    267:   PetscCall(PetscMalloc1(nrqr, &s_waits2));
    268:   for (PetscMPIInt i = 0; i < nrqr; ++i) {
    269:     PetscMPIInt j = onodes1[i];
    270:     PetscCallMPI(MPIU_Isend(xdata[i], isz1[i], MPIU_INT, j, tag2, comm, s_waits2 + i));
    271:   }

    273:   PetscCall(PetscFree(onodes1));
    274:   PetscCall(PetscFree(olengths1));

    276:   /* receive work done on other processors*/
    277:   {
    278:     PetscMPIInt idex;
    279:     PetscInt    is_no, ct1, max, *rbuf2_i, isz_i, *data_i, jmax;
    280:     PetscBT     table_i;

    282:     for (PetscMPIInt i = 0; i < nrqs; ++i) {
    283:       PetscCallMPI(MPI_Waitany(nrqs, r_waits2, &idex, MPI_STATUS_IGNORE));
    284:       /* Process the message*/
    285:       rbuf2_i = rbuf2[idex];
    286:       ct1     = 2 * rbuf2_i[0] + 1;
    287:       jmax    = rbuf2[idex][0];
    288:       for (PetscInt j = 1; j <= jmax; j++) {
    289:         max     = rbuf2_i[2 * j];
    290:         is_no   = rbuf2_i[2 * j - 1];
    291:         isz_i   = isz[is_no];
    292:         data_i  = data[is_no];
    293:         table_i = table[is_no];
    294:         for (PetscInt k = 0; k < max; k++, ct1++) {
    295:           row = rbuf2_i[ct1];
    296:           if (!PetscBTLookupSet(table_i, row)) data_i[isz_i++] = row;
    297:         }
    298:         isz[is_no] = isz_i;
    299:       }
    300:     }
    301:     PetscCallMPI(MPI_Waitall(nrqr, s_waits2, MPI_STATUSES_IGNORE));
    302:   }

    304:   for (PetscInt i = 0; i < imax; ++i) {
    305:     PetscCall(ISCreateGeneral(iscomms[i], isz[i], data[i], PETSC_COPY_VALUES, is + i));
    306:     PetscCall(PetscCommDestroy(&iscomms[i]));
    307:   }

    309:   PetscCall(PetscFree(iscomms));
    310:   PetscCall(PetscFree(onodes2));
    311:   PetscCall(PetscFree(olengths2));

    313:   PetscCall(PetscFree(pa));
    314:   if (rbuf2) {
    315:     PetscCall(PetscFree(rbuf2[0]));
    316:     PetscCall(PetscFree(rbuf2));
    317:   }
    318:   PetscCall(PetscFree(s_waits1));
    319:   PetscCall(PetscFree(r_waits1));
    320:   PetscCall(PetscFree(s_waits2));
    321:   PetscCall(PetscFree(r_waits2));
    322:   PetscCall(PetscFree5(table, data, isz, d_p, t_p));
    323:   if (xdata) {
    324:     PetscCall(PetscFree(xdata[0]));
    325:     PetscCall(PetscFree(xdata));
    326:   }
    327:   PetscCall(PetscFree(isz1));
    328:   PetscFunctionReturn(PETSC_SUCCESS);
    329: }

    331: /*
    332:    MatIncreaseOverlap_MPIBAIJ_Local - Called by MatincreaseOverlap, to do
    333:        the work on the local processor.

    335:      Inputs:
    336:       C      - MAT_MPIBAIJ;
    337:       imax - total no of index sets processed at a time;
    338:       table  - an array of char - size = Mbs bits.

    340:      Output:
    341:       isz    - array containing the count of the solution elements corresponding
    342:                to each index set;
    343:       data   - pointer to the solutions
    344: */
    345: static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat C, PetscInt imax, PetscBT *table, PetscInt *isz, PetscInt **data)
    346: {
    347:   Mat_MPIBAIJ *c = (Mat_MPIBAIJ *)C->data;
    348:   Mat          A = c->A, B = c->B;
    349:   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data, *b = (Mat_SeqBAIJ *)B->data;
    350:   PetscInt     start, end, val, max, rstart, cstart, *ai, *aj;
    351:   PetscInt    *bi, *bj, *garray, i, j, k, row, *data_i, isz_i;
    352:   PetscBT      table_i;

    354:   PetscFunctionBegin;
    355:   rstart = c->rstartbs;
    356:   cstart = c->cstartbs;
    357:   ai     = a->i;
    358:   aj     = a->j;
    359:   bi     = b->i;
    360:   bj     = b->j;
    361:   garray = c->garray;

    363:   for (i = 0; i < imax; i++) {
    364:     data_i  = data[i];
    365:     table_i = table[i];
    366:     isz_i   = isz[i];
    367:     for (j = 0, max = isz[i]; j < max; j++) {
    368:       row   = data_i[j] - rstart;
    369:       start = ai[row];
    370:       end   = ai[row + 1];
    371:       for (k = start; k < end; k++) { /* Amat */
    372:         val = aj[k] + cstart;
    373:         if (!PetscBTLookupSet(table_i, val)) data_i[isz_i++] = val;
    374:       }
    375:       start = bi[row];
    376:       end   = bi[row + 1];
    377:       for (k = start; k < end; k++) { /* Bmat */
    378:         val = garray[bj[k]];
    379:         if (!PetscBTLookupSet(table_i, val)) data_i[isz_i++] = val;
    380:       }
    381:     }
    382:     isz[i] = isz_i;
    383:   }
    384:   PetscFunctionReturn(PETSC_SUCCESS);
    385: }

    387: /*
    388:       MatIncreaseOverlap_MPIBAIJ_Receive - Process the received messages,
    389:          and return the output

    391:          Input:
    392:            C    - the matrix
    393:            nrqr - no of messages being processed.
    394:            rbuf - an array of pointers to the received requests

    396:          Output:
    397:            xdata - array of messages to be sent back
    398:            isz1  - size of each message

    400:   For better efficiency perhaps we should malloc separately each xdata[i],
    401: then if a remalloc is required we need only copy the data for that one row
    402: rather than all previous rows as it is now where a single large chunk of
    403: memory is used.

    405: */
    406: static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat C, PetscInt nrqr, PetscInt **rbuf, PetscInt **xdata, PetscInt *isz1)
    407: {
    408:   Mat_MPIBAIJ *c = (Mat_MPIBAIJ *)C->data;
    409:   Mat          A = c->A, B = c->B;
    410:   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data, *b = (Mat_SeqBAIJ *)B->data;
    411:   PetscInt     rstart, cstart, *ai, *aj, *bi, *bj, *garray, i, j, k;
    412:   PetscInt     row, total_sz, ct, ct1, ct2, ct3, mem_estimate, oct2, l, start, end;
    413:   PetscInt     val, max1, max2, Mbs, no_malloc = 0, *tmp, new_estimate, ctr;
    414:   PetscInt    *rbuf_i, kmax, rbuf_0;
    415:   PetscBT      xtable;

    417:   PetscFunctionBegin;
    418:   Mbs    = c->Mbs;
    419:   rstart = c->rstartbs;
    420:   cstart = c->cstartbs;
    421:   ai     = a->i;
    422:   aj     = a->j;
    423:   bi     = b->i;
    424:   bj     = b->j;
    425:   garray = c->garray;

    427:   for (i = 0, ct = 0, total_sz = 0; i < nrqr; ++i) {
    428:     rbuf_i = rbuf[i];
    429:     rbuf_0 = rbuf_i[0];
    430:     ct += rbuf_0;
    431:     for (j = 1; j <= rbuf_0; j++) total_sz += rbuf_i[2 * j];
    432:   }

    434:   if (c->Mbs) max1 = ct * (a->nz + b->nz) / c->Mbs;
    435:   else max1 = 1;
    436:   mem_estimate = 3 * ((total_sz > max1 ? total_sz : max1) + 1);
    437:   if (nrqr) {
    438:     PetscCall(PetscMalloc1(mem_estimate, &xdata[0]));
    439:     ++no_malloc;
    440:   }
    441:   PetscCall(PetscBTCreate(Mbs, &xtable));
    442:   PetscCall(PetscArrayzero(isz1, nrqr));

    444:   ct3 = 0;
    445:   for (i = 0; i < nrqr; i++) { /* for easch mesg from proc i */
    446:     rbuf_i = rbuf[i];
    447:     rbuf_0 = rbuf_i[0];
    448:     ct1    = 2 * rbuf_0 + 1;
    449:     ct2    = ct1;
    450:     ct3 += ct1;
    451:     for (j = 1; j <= rbuf_0; j++) { /* for each IS from proc i*/
    452:       PetscCall(PetscBTMemzero(Mbs, xtable));
    453:       oct2 = ct2;
    454:       kmax = rbuf_i[2 * j];
    455:       for (k = 0; k < kmax; k++, ct1++) {
    456:         row = rbuf_i[ct1];
    457:         if (!PetscBTLookupSet(xtable, row)) {
    458:           if (!(ct3 < mem_estimate)) {
    459:             new_estimate = (PetscInt)(1.5 * mem_estimate) + 1;
    460:             PetscCall(PetscMalloc1(new_estimate, &tmp));
    461:             PetscCall(PetscArraycpy(tmp, xdata[0], mem_estimate));
    462:             PetscCall(PetscFree(xdata[0]));
    463:             xdata[0]     = tmp;
    464:             mem_estimate = new_estimate;
    465:             ++no_malloc;
    466:             for (ctr = 1; ctr <= i; ctr++) xdata[ctr] = xdata[ctr - 1] + isz1[ctr - 1];
    467:           }
    468:           xdata[i][ct2++] = row;
    469:           ct3++;
    470:         }
    471:       }
    472:       for (k = oct2, max2 = ct2; k < max2; k++) {
    473:         row   = xdata[i][k] - rstart;
    474:         start = ai[row];
    475:         end   = ai[row + 1];
    476:         for (l = start; l < end; l++) {
    477:           val = aj[l] + cstart;
    478:           if (!PetscBTLookupSet(xtable, val)) {
    479:             if (!(ct3 < mem_estimate)) {
    480:               new_estimate = (PetscInt)(1.5 * mem_estimate) + 1;
    481:               PetscCall(PetscMalloc1(new_estimate, &tmp));
    482:               PetscCall(PetscArraycpy(tmp, xdata[0], mem_estimate));
    483:               PetscCall(PetscFree(xdata[0]));
    484:               xdata[0]     = tmp;
    485:               mem_estimate = new_estimate;
    486:               ++no_malloc;
    487:               for (ctr = 1; ctr <= i; ctr++) xdata[ctr] = xdata[ctr - 1] + isz1[ctr - 1];
    488:             }
    489:             xdata[i][ct2++] = val;
    490:             ct3++;
    491:           }
    492:         }
    493:         start = bi[row];
    494:         end   = bi[row + 1];
    495:         for (l = start; l < end; l++) {
    496:           val = garray[bj[l]];
    497:           if (!PetscBTLookupSet(xtable, val)) {
    498:             if (!(ct3 < mem_estimate)) {
    499:               new_estimate = (PetscInt)(1.5 * mem_estimate) + 1;
    500:               PetscCall(PetscMalloc1(new_estimate, &tmp));
    501:               PetscCall(PetscArraycpy(tmp, xdata[0], mem_estimate));
    502:               PetscCall(PetscFree(xdata[0]));
    503:               xdata[0]     = tmp;
    504:               mem_estimate = new_estimate;
    505:               ++no_malloc;
    506:               for (ctr = 1; ctr <= i; ctr++) xdata[ctr] = xdata[ctr - 1] + isz1[ctr - 1];
    507:             }
    508:             xdata[i][ct2++] = val;
    509:             ct3++;
    510:           }
    511:         }
    512:       }
    513:       /* Update the header*/
    514:       xdata[i][2 * j]     = ct2 - oct2; /* Undo the vector isz1 and use only a var*/
    515:       xdata[i][2 * j - 1] = rbuf_i[2 * j - 1];
    516:     }
    517:     xdata[i][0] = rbuf_0;
    518:     if (i + 1 < nrqr) xdata[i + 1] = xdata[i] + ct2;
    519:     isz1[i] = ct2; /* size of each message */
    520:   }
    521:   PetscCall(PetscBTDestroy(&xtable));
    522:   PetscCall(PetscInfo(C, "Allocated %" PetscInt_FMT " bytes, required %" PetscInt_FMT ", no of mallocs = %" PetscInt_FMT "\n", mem_estimate, ct3, no_malloc));
    523:   PetscFunctionReturn(PETSC_SUCCESS);
    524: }

    526: PetscErrorCode MatCreateSubMatrices_MPIBAIJ(Mat C, PetscInt ismax, const IS isrow[], const IS iscol[], MatReuse scall, Mat *submat[])
    527: {
    528:   IS          *isrow_block, *iscol_block;
    529:   Mat_MPIBAIJ *c = (Mat_MPIBAIJ *)C->data;
    530:   PetscInt     nmax, nstages_local, nstages, i, pos, max_no, N = C->cmap->N, bs = C->rmap->bs;
    531:   Mat_SeqBAIJ *subc;
    532:   Mat_SubSppt *smat;
    533:   PetscBool    sym = PETSC_FALSE, flg[2];

    535:   PetscFunctionBegin;
    536:   PetscCall(PetscObjectTypeCompare((PetscObject)C, MATMPISBAIJ, flg));
    537:   if (flg[0]) {
    538:     if (isrow == iscol) sym = PETSC_TRUE;
    539:     else {
    540:       flg[0] = flg[1] = PETSC_TRUE;
    541:       for (i = 0; i < ismax; i++) {
    542:         if (isrow[i] != iscol[i]) flg[0] = PETSC_FALSE;
    543:         PetscCall(ISGetLocalSize(iscol[0], &nmax));
    544:         if (nmax == C->cmap->N && flg[1]) PetscCall(ISIdentity(iscol[0], flg + 1));
    545:       }
    546:       sym = (PetscBool)(flg[0] || flg[1]);
    547:     }
    548:   }
    549:   /* The compression and expansion should be avoided. Doesn't point
    550:      out errors, might change the indices, hence buggey */
    551:   PetscCall(PetscMalloc2(ismax, &isrow_block, ismax, &iscol_block));
    552:   PetscCall(ISCompressIndicesGeneral(C->rmap->N, C->rmap->n, bs, ismax, isrow, isrow_block));
    553:   if (isrow == iscol) {
    554:     for (i = 0; i < ismax; i++) {
    555:       iscol_block[i] = isrow_block[i];
    556:       PetscCall(PetscObjectReference((PetscObject)iscol_block[i]));
    557:     }
    558:   } else PetscCall(ISCompressIndicesGeneral(N, C->cmap->n, bs, ismax, iscol, iscol_block));

    560:   /* Determine the number of stages through which submatrices are done */
    561:   if (!C->cmap->N) nmax = 20 * 1000000 / sizeof(PetscInt);
    562:   else nmax = 20 * 1000000 / (c->Nbs * sizeof(PetscInt));
    563:   if (!nmax) nmax = 1;

    565:   if (scall == MAT_INITIAL_MATRIX) {
    566:     nstages_local = ismax / nmax + ((ismax % nmax) ? 1 : 0); /* local nstages */

    568:     /* Make sure every processor loops through the nstages */
    569:     PetscCallMPI(MPIU_Allreduce(&nstages_local, &nstages, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)C)));

    571:     /* Allocate memory to hold all the submatrices and dummy submatrices */
    572:     PetscCall(PetscCalloc1(ismax + nstages, submat));
    573:   } else { /* MAT_REUSE_MATRIX */
    574:     if (ismax) {
    575:       subc = (Mat_SeqBAIJ *)((*submat)[0]->data);
    576:       smat = subc->submatis1;
    577:     } else { /* (*submat)[0] is a dummy matrix */
    578:       smat = (Mat_SubSppt *)(*submat)[0]->data;
    579:     }
    580:     PetscCheck(smat, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "MatCreateSubMatrices(...,MAT_REUSE_MATRIX,...) requires submat");
    581:     nstages = smat->nstages;
    582:   }

    584:   for (i = 0, pos = 0; i < nstages; i++) {
    585:     if (pos + nmax <= ismax) max_no = nmax;
    586:     else if (pos >= ismax) max_no = 0;
    587:     else max_no = ismax - pos;

    589:     PetscCall(MatCreateSubMatrices_MPIBAIJ_local(C, max_no, isrow_block + pos, iscol_block + pos, scall, *submat + pos, sym));
    590:     if (!max_no) {
    591:       if (scall == MAT_INITIAL_MATRIX) { /* submat[pos] is a dummy matrix */
    592:         smat          = (Mat_SubSppt *)(*submat)[pos]->data;
    593:         smat->nstages = nstages;
    594:       }
    595:       pos++; /* advance to next dummy matrix if any */
    596:     } else pos += max_no;
    597:   }

    599:   if (scall == MAT_INITIAL_MATRIX && ismax) {
    600:     /* save nstages for reuse */
    601:     subc          = (Mat_SeqBAIJ *)((*submat)[0]->data);
    602:     smat          = subc->submatis1;
    603:     smat->nstages = nstages;
    604:   }

    606:   for (i = 0; i < ismax; i++) {
    607:     PetscCall(ISDestroy(&isrow_block[i]));
    608:     PetscCall(ISDestroy(&iscol_block[i]));
    609:   }
    610:   PetscCall(PetscFree2(isrow_block, iscol_block));
    611:   PetscFunctionReturn(PETSC_SUCCESS);
    612: }

    614: /* This code is used for BAIJ and SBAIJ matrices (unfortunate dependency) */
    615: PetscErrorCode MatCreateSubMatrices_MPIBAIJ_local(Mat C, PetscInt ismax, const IS isrow[], const IS iscol[], MatReuse scall, Mat *submats, PetscBool sym)
    616: {
    617:   Mat_MPIBAIJ     *c = (Mat_MPIBAIJ *)C->data;
    618:   Mat              A = c->A;
    619:   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data, *b = (Mat_SeqBAIJ *)c->B->data, *subc;
    620:   const PetscInt **icol, **irow;
    621:   PetscInt        *nrow, *ncol, start;
    622:   PetscMPIInt     *pa, **row2proc, *row2proc_i, proc = -1;
    623:   PetscMPIInt      rank, size, tag0, tag2, tag3, tag4, *w1, *w2, *w3, *w4, nrqr, nrqs = 0, *req_source1 = NULL, *req_source2;
    624:   PetscInt       **sbuf1, **sbuf2, *sbuf2_i, ct1, ct2, **rbuf1, row;
    625:   PetscInt         msz, **ptr = NULL, *req_size = NULL, *ctr = NULL, *tmp = NULL, tcol;
    626:   PetscInt       **rbuf3 = NULL, **sbuf_aj, **rbuf2 = NULL, max1, max2;
    627:   PetscInt       **lens, is_no, ncols, *cols, mat_i, *mat_j, tmp2, jmax;
    628: #if defined(PETSC_USE_CTABLE)
    629:   PetscHMapI *cmap, cmap_i = NULL, *rmap, rmap_i;
    630: #else
    631:   PetscInt **cmap, *cmap_i = NULL, **rmap, *rmap_i;
    632: #endif
    633:   const PetscInt *irow_i, *icol_i;
    634:   PetscInt        ctr_j, *sbuf1_j, *sbuf_aj_i, *rbuf1_i, kmax, *lens_i, jcnt;
    635:   MPI_Request    *s_waits1, *r_waits1, *s_waits2, *r_waits2, *r_waits3;
    636:   MPI_Request    *r_waits4, *s_waits3, *s_waits4;
    637:   MPI_Comm        comm;
    638:   PetscScalar   **rbuf4, *rbuf4_i = NULL, **sbuf_aa, *vals, *mat_a = NULL, *imat_a = NULL, *sbuf_aa_i;
    639:   PetscMPIInt    *onodes1, *olengths1, end;
    640:   PetscInt       *imat_ilen, *imat_j, *imat_i;
    641:   Mat_SubSppt    *smat_i;
    642:   PetscBool      *issorted, colflag, iscsorted = PETSC_TRUE;
    643:   PetscInt       *sbuf1_i, *rbuf2_i, *rbuf3_i, ilen;
    644:   PetscInt        bs = C->rmap->bs, bs2 = c->bs2, rstart = c->rstartbs;
    645:   PetscBool       ijonly = c->ijonly; /* private flag indicates only matrix data structures are requested */
    646:   PetscInt        nzA, nzB, *a_i = a->i, *b_i = b->i, *a_j = a->j, *b_j = b->j, ctmp, imark, *cworkA, *cworkB;
    647:   PetscScalar    *vworkA = NULL, *vworkB = NULL, *a_a = a->a, *b_a = b->a;
    648:   PetscInt        cstart = c->cstartbs, *bmap = c->garray;
    649:   PetscBool      *allrows, *allcolumns;

    651:   PetscFunctionBegin;
    652:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
    653:   size = c->size;
    654:   rank = c->rank;

    656:   PetscCall(PetscMalloc5(ismax, &row2proc, ismax, &cmap, ismax, &rmap, ismax + 1, &allcolumns, ismax, &allrows));
    657:   PetscCall(PetscMalloc5(ismax, (PetscInt ***)&irow, ismax, (PetscInt ***)&icol, ismax, &nrow, ismax, &ncol, ismax, &issorted));

    659:   for (PetscInt i = 0; i < ismax; i++) {
    660:     PetscCall(ISSorted(iscol[i], &issorted[i]));
    661:     if (!issorted[i]) iscsorted = issorted[i]; /* columns are not sorted! */
    662:     PetscCall(ISSorted(isrow[i], &issorted[i]));

    664:     /* Check for special case: allcolumns */
    665:     PetscCall(ISIdentity(iscol[i], &colflag));
    666:     PetscCall(ISGetLocalSize(iscol[i], &ncol[i]));

    668:     if (colflag && ncol[i] == c->Nbs) {
    669:       allcolumns[i] = PETSC_TRUE;
    670:       icol[i]       = NULL;
    671:     } else {
    672:       allcolumns[i] = PETSC_FALSE;
    673:       PetscCall(ISGetIndices(iscol[i], &icol[i]));
    674:     }

    676:     /* Check for special case: allrows */
    677:     PetscCall(ISIdentity(isrow[i], &colflag));
    678:     PetscCall(ISGetLocalSize(isrow[i], &nrow[i]));
    679:     if (colflag && nrow[i] == c->Mbs) {
    680:       allrows[i] = PETSC_TRUE;
    681:       irow[i]    = NULL;
    682:     } else {
    683:       allrows[i] = PETSC_FALSE;
    684:       PetscCall(ISGetIndices(isrow[i], &irow[i]));
    685:     }
    686:   }

    688:   if (scall == MAT_REUSE_MATRIX) {
    689:     /* Assumes new rows are same length as the old rows */
    690:     for (PetscInt i = 0; i < ismax; i++) {
    691:       subc = (Mat_SeqBAIJ *)submats[i]->data;

    693:       PetscCheck(subc->mbs == nrow[i] && subc->nbs == ncol[i], PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Cannot reuse matrix. wrong size");

    695:       /* Initial matrix as if empty */
    696:       PetscCall(PetscArrayzero(subc->ilen, subc->mbs));

    698:       /* Initial matrix as if empty */
    699:       submats[i]->factortype = C->factortype;

    701:       smat_i = subc->submatis1;

    703:       nrqs        = smat_i->nrqs;
    704:       nrqr        = smat_i->nrqr;
    705:       rbuf1       = smat_i->rbuf1;
    706:       rbuf2       = smat_i->rbuf2;
    707:       rbuf3       = smat_i->rbuf3;
    708:       req_source2 = smat_i->req_source2;

    710:       sbuf1 = smat_i->sbuf1;
    711:       sbuf2 = smat_i->sbuf2;
    712:       ptr   = smat_i->ptr;
    713:       tmp   = smat_i->tmp;
    714:       ctr   = smat_i->ctr;

    716:       pa          = smat_i->pa;
    717:       req_size    = smat_i->req_size;
    718:       req_source1 = smat_i->req_source1;

    720:       allcolumns[i] = smat_i->allcolumns;
    721:       allrows[i]    = smat_i->allrows;
    722:       row2proc[i]   = smat_i->row2proc;
    723:       rmap[i]       = smat_i->rmap;
    724:       cmap[i]       = smat_i->cmap;
    725:     }

    727:     if (!ismax) { /* Get dummy submatrices and retrieve struct submatis1 */
    728:       PetscCheck(submats[0], PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "submats are null, cannot reuse");
    729:       smat_i = (Mat_SubSppt *)submats[0]->data;

    731:       nrqs        = smat_i->nrqs;
    732:       nrqr        = smat_i->nrqr;
    733:       rbuf1       = smat_i->rbuf1;
    734:       rbuf2       = smat_i->rbuf2;
    735:       rbuf3       = smat_i->rbuf3;
    736:       req_source2 = smat_i->req_source2;

    738:       sbuf1 = smat_i->sbuf1;
    739:       sbuf2 = smat_i->sbuf2;
    740:       ptr   = smat_i->ptr;
    741:       tmp   = smat_i->tmp;
    742:       ctr   = smat_i->ctr;

    744:       pa          = smat_i->pa;
    745:       req_size    = smat_i->req_size;
    746:       req_source1 = smat_i->req_source1;

    748:       allcolumns[0] = PETSC_FALSE;
    749:     }
    750:   } else { /* scall == MAT_INITIAL_MATRIX */
    751:     /* Get some new tags to keep the communication clean */
    752:     PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag2));
    753:     PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag3));

    755:     /* evaluate communication - mesg to who, length of mesg, and buffer space
    756:      required. Based on this, buffers are allocated, and data copied into them*/
    757:     PetscCall(PetscCalloc4(size, &w1, size, &w2, size, &w3, size, &w4)); /* mesg size, initialize work vectors */

    759:     for (PetscInt i = 0; i < ismax; i++) {
    760:       jmax   = nrow[i];
    761:       irow_i = irow[i];

    763:       PetscCall(PetscMalloc1(jmax, &row2proc_i));
    764:       row2proc[i] = row2proc_i;

    766:       if (issorted[i]) proc = 0;
    767:       for (PetscInt j = 0; j < jmax; j++) {
    768:         if (!issorted[i]) proc = 0;
    769:         if (allrows[i]) row = j;
    770:         else row = irow_i[j];

    772:         while (row >= c->rangebs[proc + 1]) proc++;
    773:         w4[proc]++;
    774:         row2proc_i[j] = proc; /* map row index to proc */
    775:       }
    776:       for (PetscMPIInt j = 0; j < size; j++) {
    777:         if (w4[j]) {
    778:           w1[j] += w4[j];
    779:           w3[j]++;
    780:           w4[j] = 0;
    781:         }
    782:       }
    783:     }

    785:     nrqs     = 0; /* no of outgoing messages */
    786:     msz      = 0; /* total mesg length (for all procs) */
    787:     w1[rank] = 0; /* no mesg sent to self */
    788:     w3[rank] = 0;
    789:     for (PetscMPIInt i = 0; i < size; i++) {
    790:       if (w1[i]) {
    791:         w2[i] = 1;
    792:         nrqs++;
    793:       } /* there exists a message to proc i */
    794:     }
    795:     PetscCall(PetscMalloc1(nrqs, &pa)); /*(proc -array)*/
    796:     for (PetscMPIInt i = 0, j = 0; i < size; i++) {
    797:       if (w1[i]) { pa[j++] = i; }
    798:     }

    800:     /* Each message would have a header = 1 + 2*(no of IS) + data */
    801:     for (PetscMPIInt i = 0; i < nrqs; i++) {
    802:       PetscMPIInt j = pa[i];
    803:       w1[j] += w2[j] + 2 * w3[j];
    804:       msz += w1[j];
    805:     }
    806:     PetscCall(PetscInfo(0, "Number of outgoing messages %d Total message length %" PetscInt_FMT "\n", nrqs, msz));

    808:     /* Determine the number of messages to expect, their lengths, from from-ids */
    809:     PetscCall(PetscGatherNumberOfMessages(comm, w2, w1, &nrqr));
    810:     PetscCall(PetscGatherMessageLengths(comm, nrqs, nrqr, w1, &onodes1, &olengths1));

    812:     /* Now post the Irecvs corresponding to these messages */
    813:     PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag0));
    814:     PetscCall(PetscPostIrecvInt(comm, tag0, nrqr, onodes1, olengths1, &rbuf1, &r_waits1));

    816:     /* Allocate Memory for outgoing messages */
    817:     PetscCall(PetscMalloc4(size, &sbuf1, size, &ptr, 2 * msz, &tmp, size, &ctr));
    818:     PetscCall(PetscArrayzero(sbuf1, size));
    819:     PetscCall(PetscArrayzero(ptr, size));

    821:     {
    822:       PetscInt   *iptr = tmp;
    823:       PetscMPIInt k    = 0;
    824:       for (PetscMPIInt i = 0; i < nrqs; i++) {
    825:         PetscMPIInt j = pa[i];
    826:         iptr += k;
    827:         sbuf1[j] = iptr;
    828:         k        = w1[j];
    829:       }
    830:     }

    832:     /* Form the outgoing messages. Initialize the header space */
    833:     for (PetscMPIInt i = 0; i < nrqs; i++) {
    834:       PetscMPIInt j = pa[i];

    836:       sbuf1[j][0] = 0;
    837:       PetscCall(PetscArrayzero(sbuf1[j] + 1, 2 * w3[j]));
    838:       ptr[j] = sbuf1[j] + 2 * w3[j] + 1;
    839:     }

    841:     /* Parse the isrow and copy data into outbuf */
    842:     for (PetscInt i = 0; i < ismax; i++) {
    843:       row2proc_i = row2proc[i];
    844:       PetscCall(PetscArrayzero(ctr, size));
    845:       irow_i = irow[i];
    846:       jmax   = nrow[i];
    847:       for (PetscInt j = 0; j < jmax; j++) { /* parse the indices of each IS */
    848:         proc = row2proc_i[j];
    849:         if (allrows[i]) row = j;
    850:         else row = irow_i[j];

    852:         if (proc != rank) { /* copy to the outgoing buf*/
    853:           ctr[proc]++;
    854:           *ptr[proc] = row;
    855:           ptr[proc]++;
    856:         }
    857:       }
    858:       /* Update the headers for the current IS */
    859:       for (PetscMPIInt j = 0; j < size; j++) { /* Can Optimise this loop too */
    860:         if ((ctr_j = ctr[j])) {
    861:           PetscInt k;

    863:           sbuf1_j            = sbuf1[j];
    864:           k                  = ++sbuf1_j[0];
    865:           sbuf1_j[2 * k]     = ctr_j;
    866:           sbuf1_j[2 * k - 1] = i;
    867:         }
    868:       }
    869:     }

    871:     /*  Now  post the sends */
    872:     PetscCall(PetscMalloc1(nrqs, &s_waits1));
    873:     for (PetscMPIInt i = 0; i < nrqs; ++i) {
    874:       PetscMPIInt j = pa[i];
    875:       PetscCallMPI(MPIU_Isend(sbuf1[j], w1[j], MPIU_INT, j, tag0, comm, s_waits1 + i));
    876:     }

    878:     /* Post Receives to capture the buffer size */
    879:     PetscCall(PetscMalloc1(nrqs, &r_waits2));
    880:     PetscCall(PetscMalloc3(nrqs, &req_source2, nrqs, &rbuf2, nrqs, &rbuf3));
    881:     if (nrqs) rbuf2[0] = tmp + msz;
    882:     for (PetscMPIInt i = 1; i < nrqs; ++i) rbuf2[i] = rbuf2[i - 1] + w1[pa[i - 1]];
    883:     for (PetscMPIInt i = 0; i < nrqs; ++i) {
    884:       PetscMPIInt j = pa[i];
    885:       PetscCallMPI(MPIU_Irecv(rbuf2[i], w1[j], MPIU_INT, j, tag2, comm, r_waits2 + i));
    886:     }

    888:     /* Send to other procs the buf size they should allocate */
    889:     /* Receive messages*/
    890:     PetscCall(PetscMalloc1(nrqr, &s_waits2));
    891:     PetscCall(PetscMalloc3(nrqr, &sbuf2, nrqr, &req_size, nrqr, &req_source1));

    893:     PetscCallMPI(MPI_Waitall(nrqr, r_waits1, MPI_STATUSES_IGNORE));
    894:     for (PetscMPIInt i = 0; i < nrqr; ++i) {
    895:       req_size[i] = 0;
    896:       rbuf1_i     = rbuf1[i];
    897:       start       = 2 * rbuf1_i[0] + 1;
    898:       end         = olengths1[i];
    899:       PetscCall(PetscMalloc1(end, &sbuf2[i]));
    900:       sbuf2_i = sbuf2[i];
    901:       for (PetscInt j = start; j < end; j++) {
    902:         row        = rbuf1_i[j] - rstart;
    903:         ncols      = a_i[row + 1] - a_i[row] + b_i[row + 1] - b_i[row];
    904:         sbuf2_i[j] = ncols;
    905:         req_size[i] += ncols;
    906:       }
    907:       req_source1[i] = onodes1[i];
    908:       /* form the header */
    909:       sbuf2_i[0] = req_size[i];
    910:       for (PetscInt j = 1; j < start; j++) sbuf2_i[j] = rbuf1_i[j];

    912:       PetscCallMPI(MPIU_Isend(sbuf2_i, end, MPIU_INT, req_source1[i], tag2, comm, s_waits2 + i));
    913:     }
    914:     PetscCall(PetscFree(onodes1));
    915:     PetscCall(PetscFree(olengths1));

    917:     PetscCall(PetscFree(r_waits1));
    918:     PetscCall(PetscFree4(w1, w2, w3, w4));

    920:     /* Receive messages*/
    921:     PetscCall(PetscMalloc1(nrqs, &r_waits3));

    923:     PetscCallMPI(MPI_Waitall(nrqs, r_waits2, MPI_STATUSES_IGNORE));
    924:     for (PetscMPIInt i = 0; i < nrqs; ++i) {
    925:       PetscCall(PetscMalloc1(rbuf2[i][0], &rbuf3[i]));
    926:       req_source2[i] = pa[i];
    927:       PetscCallMPI(MPIU_Irecv(rbuf3[i], rbuf2[i][0], MPIU_INT, req_source2[i], tag3, comm, r_waits3 + i));
    928:     }
    929:     PetscCall(PetscFree(r_waits2));

    931:     /* Wait on sends1 and sends2 */
    932:     PetscCallMPI(MPI_Waitall(nrqs, s_waits1, MPI_STATUSES_IGNORE));
    933:     PetscCallMPI(MPI_Waitall(nrqr, s_waits2, MPI_STATUSES_IGNORE));
    934:     PetscCall(PetscFree(s_waits1));
    935:     PetscCall(PetscFree(s_waits2));

    937:     /* Now allocate sending buffers for a->j, and send them off */
    938:     PetscCall(PetscMalloc1(nrqr, &sbuf_aj));
    939:     jcnt = 0;
    940:     for (PetscMPIInt i = 0; i < nrqr; i++) jcnt += req_size[i];
    941:     if (nrqr) PetscCall(PetscMalloc1(jcnt, &sbuf_aj[0]));
    942:     for (PetscMPIInt i = 1; i < nrqr; i++) sbuf_aj[i] = sbuf_aj[i - 1] + req_size[i - 1];

    944:     PetscCall(PetscMalloc1(nrqr, &s_waits3));
    945:     {
    946:       for (PetscMPIInt i = 0; i < nrqr; i++) {
    947:         rbuf1_i   = rbuf1[i];
    948:         sbuf_aj_i = sbuf_aj[i];
    949:         ct1       = 2 * rbuf1_i[0] + 1;
    950:         ct2       = 0;
    951:         for (PetscInt j = 1, max1 = rbuf1_i[0]; j <= max1; j++) {
    952:           kmax = rbuf1[i][2 * j];
    953:           for (PetscInt k = 0; k < kmax; k++, ct1++) {
    954:             PetscInt l;
    955:             row    = rbuf1_i[ct1] - rstart;
    956:             nzA    = a_i[row + 1] - a_i[row];
    957:             nzB    = b_i[row + 1] - b_i[row];
    958:             ncols  = nzA + nzB;
    959:             cworkA = PetscSafePointerPlusOffset(a_j, a_i[row]);
    960:             cworkB = PetscSafePointerPlusOffset(b_j, b_i[row]);

    962:             /* load the column indices for this row into cols */
    963:             cols = sbuf_aj_i + ct2;
    964:             for (l = 0; l < nzB; l++) {
    965:               if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
    966:               else break;
    967:             }
    968:             imark = l;
    969:             for (l = 0; l < nzA; l++) cols[imark + l] = cstart + cworkA[l];
    970:             for (l = imark; l < nzB; l++) cols[nzA + l] = bmap[cworkB[l]];
    971:             ct2 += ncols;
    972:           }
    973:         }
    974:         PetscCallMPI(MPIU_Isend(sbuf_aj_i, req_size[i], MPIU_INT, req_source1[i], tag3, comm, s_waits3 + i));
    975:       }
    976:     }

    978:     /* create col map: global col of C -> local col of submatrices */
    979: #if defined(PETSC_USE_CTABLE)
    980:     for (PetscInt i = 0; i < ismax; i++) {
    981:       if (!allcolumns[i]) {
    982:         PetscCall(PetscHMapICreateWithSize(ncol[i], cmap + i));

    984:         jmax   = ncol[i];
    985:         icol_i = icol[i];
    986:         cmap_i = cmap[i];
    987:         for (PetscInt j = 0; j < jmax; j++) PetscCall(PetscHMapISet(cmap[i], icol_i[j] + 1, j + 1));
    988:       } else cmap[i] = NULL;
    989:     }
    990: #else
    991:     for (PetscInt i = 0; i < ismax; i++) {
    992:       if (!allcolumns[i]) {
    993:         PetscCall(PetscCalloc1(c->Nbs, &cmap[i]));
    994:         jmax   = ncol[i];
    995:         icol_i = icol[i];
    996:         cmap_i = cmap[i];
    997:         for (PetscInt j = 0; j < jmax; j++) cmap_i[icol_i[j]] = j + 1;
    998:       } else cmap[i] = NULL;
    999:     }
    1000: #endif

    1002:     /* Create lens which is required for MatCreate... */
    1003:     jcnt = 0;
    1004:     for (PetscInt i = 0; i < ismax; i++) jcnt += nrow[i];
    1005:     PetscCall(PetscMalloc1(ismax, &lens));
    1006:     if (ismax) PetscCall(PetscCalloc1(jcnt, &lens[0]));
    1007:     for (PetscInt i = 1; i < ismax; i++) lens[i] = PetscSafePointerPlusOffset(lens[i - 1], nrow[i - 1]);

    1009:     /* Update lens from local data */
    1010:     for (PetscInt i = 0; i < ismax; i++) {
    1011:       row2proc_i = row2proc[i];
    1012:       jmax       = nrow[i];
    1013:       if (!allcolumns[i]) cmap_i = cmap[i];
    1014:       irow_i = irow[i];
    1015:       lens_i = lens[i];
    1016:       for (PetscInt j = 0; j < jmax; j++) {
    1017:         if (allrows[i]) row = j;
    1018:         else row = irow_i[j]; /* global blocked row of C */

    1020:         proc = row2proc_i[j];
    1021:         if (proc == rank) {
    1022:           /* Get indices from matA and then from matB */
    1023: #if defined(PETSC_USE_CTABLE)
    1024:           PetscInt tt;
    1025: #endif
    1026:           row    = row - rstart;
    1027:           nzA    = a_i[row + 1] - a_i[row];
    1028:           nzB    = b_i[row + 1] - b_i[row];
    1029:           cworkA = a_j + a_i[row];
    1030:           cworkB = PetscSafePointerPlusOffset(b_j, b_i[row]);

    1032:           if (!allcolumns[i]) {
    1033: #if defined(PETSC_USE_CTABLE)
    1034:             for (PetscInt k = 0; k < nzA; k++) {
    1035:               PetscCall(PetscHMapIGetWithDefault(cmap_i, cstart + cworkA[k] + 1, 0, &tt));
    1036:               if (tt) lens_i[j]++;
    1037:             }
    1038:             for (PetscInt k = 0; k < nzB; k++) {
    1039:               PetscCall(PetscHMapIGetWithDefault(cmap_i, bmap[cworkB[k]] + 1, 0, &tt));
    1040:               if (tt) lens_i[j]++;
    1041:             }

    1043: #else
    1044:             for (PetscInt k = 0; k < nzA; k++) {
    1045:               if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
    1046:             }
    1047:             for (PetscInt k = 0; k < nzB; k++) {
    1048:               if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
    1049:             }
    1050: #endif
    1051:           } else { /* allcolumns */
    1052:             lens_i[j] = nzA + nzB;
    1053:           }
    1054:         }
    1055:       }
    1056:     }

    1058:     /* Create row map: global row of C -> local row of submatrices */
    1059:     for (PetscInt i = 0; i < ismax; i++) {
    1060:       if (!allrows[i]) {
    1061: #if defined(PETSC_USE_CTABLE)
    1062:         PetscCall(PetscHMapICreateWithSize(nrow[i], rmap + i));
    1063:         irow_i = irow[i];
    1064:         jmax   = nrow[i];
    1065:         for (PetscInt j = 0; j < jmax; j++) {
    1066:           if (allrows[i]) {
    1067:             PetscCall(PetscHMapISet(rmap[i], j + 1, j + 1));
    1068:           } else {
    1069:             PetscCall(PetscHMapISet(rmap[i], irow_i[j] + 1, j + 1));
    1070:           }
    1071:         }
    1072: #else
    1073:         PetscCall(PetscCalloc1(c->Mbs, &rmap[i]));
    1074:         rmap_i = rmap[i];
    1075:         irow_i = irow[i];
    1076:         jmax   = nrow[i];
    1077:         for (PetscInt j = 0; j < jmax; j++) {
    1078:           if (allrows[i]) rmap_i[j] = j;
    1079:           else rmap_i[irow_i[j]] = j;
    1080:         }
    1081: #endif
    1082:       } else rmap[i] = NULL;
    1083:     }

    1085:     /* Update lens from offproc data */
    1086:     {
    1087:       PetscInt *rbuf2_i, *rbuf3_i, *sbuf1_i;

    1089:       PetscCallMPI(MPI_Waitall(nrqs, r_waits3, MPI_STATUSES_IGNORE));
    1090:       for (tmp2 = 0; tmp2 < nrqs; tmp2++) {
    1091:         sbuf1_i = sbuf1[pa[tmp2]];
    1092:         jmax    = sbuf1_i[0];
    1093:         ct1     = 2 * jmax + 1;
    1094:         ct2     = 0;
    1095:         rbuf2_i = rbuf2[tmp2];
    1096:         rbuf3_i = rbuf3[tmp2];
    1097:         for (PetscInt j = 1; j <= jmax; j++) {
    1098:           is_no  = sbuf1_i[2 * j - 1];
    1099:           max1   = sbuf1_i[2 * j];
    1100:           lens_i = lens[is_no];
    1101:           if (!allcolumns[is_no]) cmap_i = cmap[is_no];
    1102:           rmap_i = rmap[is_no];
    1103:           for (PetscInt k = 0; k < max1; k++, ct1++) {
    1104:             if (allrows[is_no]) {
    1105:               row = sbuf1_i[ct1];
    1106:             } else {
    1107: #if defined(PETSC_USE_CTABLE)
    1108:               PetscCall(PetscHMapIGetWithDefault(rmap_i, sbuf1_i[ct1] + 1, 0, &row));
    1109:               row--;
    1110:               PetscCheck(row >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "row not found in table");
    1111: #else
    1112:               row = rmap_i[sbuf1_i[ct1]]; /* the val in the new matrix to be */
    1113: #endif
    1114:             }
    1115:             max2 = rbuf2_i[ct1];
    1116:             for (PetscInt l = 0; l < max2; l++, ct2++) {
    1117:               if (!allcolumns[is_no]) {
    1118: #if defined(PETSC_USE_CTABLE)
    1119:                 PetscCall(PetscHMapIGetWithDefault(cmap_i, rbuf3_i[ct2] + 1, 0, &tcol));
    1120: #else
    1121:                 tcol = cmap_i[rbuf3_i[ct2]];
    1122: #endif
    1123:                 if (tcol) lens_i[row]++;
    1124:               } else {         /* allcolumns */
    1125:                 lens_i[row]++; /* lens_i[row] += max2 ? */
    1126:               }
    1127:             }
    1128:           }
    1129:         }
    1130:       }
    1131:     }
    1132:     PetscCall(PetscFree(r_waits3));
    1133:     PetscCallMPI(MPI_Waitall(nrqr, s_waits3, MPI_STATUSES_IGNORE));
    1134:     PetscCall(PetscFree(s_waits3));

    1136:     /* Create the submatrices */
    1137:     for (PetscInt i = 0; i < ismax; i++) {
    1138:       PetscInt bs_tmp;
    1139:       if (ijonly) bs_tmp = 1;
    1140:       else bs_tmp = bs;

    1142:       PetscCall(MatCreate(PETSC_COMM_SELF, submats + i));
    1143:       PetscCall(MatSetSizes(submats[i], nrow[i] * bs_tmp, ncol[i] * bs_tmp, PETSC_DETERMINE, PETSC_DETERMINE));

    1145:       PetscCall(MatSetType(submats[i], sym ? ((PetscObject)A)->type_name : MATSEQBAIJ));
    1146:       PetscCall(MatSeqBAIJSetPreallocation(submats[i], bs_tmp, 0, lens[i]));
    1147:       PetscCall(MatSeqSBAIJSetPreallocation(submats[i], bs_tmp, 0, lens[i])); /* this subroutine is used by SBAIJ routines */

    1149:       /* create struct Mat_SubSppt and attached it to submat */
    1150:       PetscCall(PetscNew(&smat_i));
    1151:       subc            = (Mat_SeqBAIJ *)submats[i]->data;
    1152:       subc->submatis1 = smat_i;

    1154:       smat_i->destroy          = submats[i]->ops->destroy;
    1155:       submats[i]->ops->destroy = MatDestroySubMatrix_SeqBAIJ;
    1156:       submats[i]->factortype   = C->factortype;

    1158:       smat_i->id          = i;
    1159:       smat_i->nrqs        = nrqs;
    1160:       smat_i->nrqr        = nrqr;
    1161:       smat_i->rbuf1       = rbuf1;
    1162:       smat_i->rbuf2       = rbuf2;
    1163:       smat_i->rbuf3       = rbuf3;
    1164:       smat_i->sbuf2       = sbuf2;
    1165:       smat_i->req_source2 = req_source2;

    1167:       smat_i->sbuf1 = sbuf1;
    1168:       smat_i->ptr   = ptr;
    1169:       smat_i->tmp   = tmp;
    1170:       smat_i->ctr   = ctr;

    1172:       smat_i->pa          = pa;
    1173:       smat_i->req_size    = req_size;
    1174:       smat_i->req_source1 = req_source1;

    1176:       smat_i->allcolumns = allcolumns[i];
    1177:       smat_i->allrows    = allrows[i];
    1178:       smat_i->singleis   = PETSC_FALSE;
    1179:       smat_i->row2proc   = row2proc[i];
    1180:       smat_i->rmap       = rmap[i];
    1181:       smat_i->cmap       = cmap[i];
    1182:     }

    1184:     if (!ismax) { /* Create dummy submats[0] for reuse struct subc */
    1185:       PetscCall(MatCreate(PETSC_COMM_SELF, &submats[0]));
    1186:       PetscCall(MatSetSizes(submats[0], 0, 0, PETSC_DETERMINE, PETSC_DETERMINE));
    1187:       PetscCall(MatSetType(submats[0], MATDUMMY));

    1189:       /* create struct Mat_SubSppt and attached it to submat */
    1190:       PetscCall(PetscNew(&smat_i));
    1191:       submats[0]->data = (void *)smat_i;

    1193:       smat_i->destroy          = submats[0]->ops->destroy;
    1194:       submats[0]->ops->destroy = MatDestroySubMatrix_Dummy;
    1195:       submats[0]->factortype   = C->factortype;

    1197:       smat_i->id          = 0;
    1198:       smat_i->nrqs        = nrqs;
    1199:       smat_i->nrqr        = nrqr;
    1200:       smat_i->rbuf1       = rbuf1;
    1201:       smat_i->rbuf2       = rbuf2;
    1202:       smat_i->rbuf3       = rbuf3;
    1203:       smat_i->sbuf2       = sbuf2;
    1204:       smat_i->req_source2 = req_source2;

    1206:       smat_i->sbuf1 = sbuf1;
    1207:       smat_i->ptr   = ptr;
    1208:       smat_i->tmp   = tmp;
    1209:       smat_i->ctr   = ctr;

    1211:       smat_i->pa          = pa;
    1212:       smat_i->req_size    = req_size;
    1213:       smat_i->req_source1 = req_source1;

    1215:       smat_i->allcolumns = PETSC_FALSE;
    1216:       smat_i->singleis   = PETSC_FALSE;
    1217:       smat_i->row2proc   = NULL;
    1218:       smat_i->rmap       = NULL;
    1219:       smat_i->cmap       = NULL;
    1220:     }

    1222:     if (ismax) PetscCall(PetscFree(lens[0]));
    1223:     PetscCall(PetscFree(lens));
    1224:     if (sbuf_aj) {
    1225:       PetscCall(PetscFree(sbuf_aj[0]));
    1226:       PetscCall(PetscFree(sbuf_aj));
    1227:     }

    1229:   } /* endof scall == MAT_INITIAL_MATRIX */

    1231:   /* Post recv matrix values */
    1232:   if (!ijonly) {
    1233:     PetscCall(PetscObjectGetNewTag((PetscObject)C, &tag4));
    1234:     PetscCall(PetscMalloc1(nrqs, &rbuf4));
    1235:     PetscCall(PetscMalloc1(nrqs, &r_waits4));
    1236:     for (PetscMPIInt i = 0; i < nrqs; ++i) {
    1237:       PetscCall(PetscMalloc1(rbuf2[i][0] * bs2, &rbuf4[i]));
    1238:       PetscCallMPI(MPIU_Irecv(rbuf4[i], rbuf2[i][0] * bs2, MPIU_SCALAR, req_source2[i], tag4, comm, r_waits4 + i));
    1239:     }

    1241:     /* Allocate sending buffers for a->a, and send them off */
    1242:     PetscCall(PetscMalloc1(nrqr, &sbuf_aa));
    1243:     jcnt = 0;
    1244:     for (PetscMPIInt i = 0; i < nrqr; i++) jcnt += req_size[i];
    1245:     if (nrqr) PetscCall(PetscMalloc1(jcnt * bs2, &sbuf_aa[0]));
    1246:     for (PetscMPIInt i = 1; i < nrqr; i++) sbuf_aa[i] = sbuf_aa[i - 1] + req_size[i - 1] * bs2;

    1248:     PetscCall(PetscMalloc1(nrqr, &s_waits4));

    1250:     for (PetscMPIInt i = 0; i < nrqr; i++) {
    1251:       rbuf1_i   = rbuf1[i];
    1252:       sbuf_aa_i = sbuf_aa[i];
    1253:       ct1       = 2 * rbuf1_i[0] + 1;
    1254:       ct2       = 0;
    1255:       for (PetscInt j = 1, max1 = rbuf1_i[0]; j <= max1; j++) {
    1256:         kmax = rbuf1_i[2 * j];
    1257:         for (PetscInt k = 0; k < kmax; k++, ct1++) {
    1258:           PetscInt l;

    1260:           row    = rbuf1_i[ct1] - rstart;
    1261:           nzA    = a_i[row + 1] - a_i[row];
    1262:           nzB    = b_i[row + 1] - b_i[row];
    1263:           ncols  = nzA + nzB;
    1264:           cworkB = PetscSafePointerPlusOffset(b_j, b_i[row]);
    1265:           vworkA = PetscSafePointerPlusOffset(a_a, a_i[row] * bs2);
    1266:           vworkB = PetscSafePointerPlusOffset(b_a, b_i[row] * bs2);

    1268:           /* load the column values for this row into vals*/
    1269:           vals = sbuf_aa_i + ct2 * bs2;
    1270:           for (l = 0; l < nzB; l++) {
    1271:             if ((bmap[cworkB[l]]) < cstart) {
    1272:               PetscCall(PetscArraycpy(vals + l * bs2, vworkB + l * bs2, bs2));
    1273:             } else break;
    1274:           }
    1275:           imark = l;
    1276:           for (l = 0; l < nzA; l++) PetscCall(PetscArraycpy(vals + (imark + l) * bs2, vworkA + l * bs2, bs2));
    1277:           for (l = imark; l < nzB; l++) PetscCall(PetscArraycpy(vals + (nzA + l) * bs2, vworkB + l * bs2, bs2));

    1279:           ct2 += ncols;
    1280:         }
    1281:       }
    1282:       PetscCallMPI(MPIU_Isend(sbuf_aa_i, req_size[i] * bs2, MPIU_SCALAR, req_source1[i], tag4, comm, s_waits4 + i));
    1283:     }
    1284:   }

    1286:   /* Assemble the matrices */
    1287:   /* First assemble the local rows */
    1288:   for (PetscInt i = 0; i < ismax; i++) {
    1289:     row2proc_i = row2proc[i];
    1290:     subc       = (Mat_SeqBAIJ *)submats[i]->data;
    1291:     imat_ilen  = subc->ilen;
    1292:     imat_j     = subc->j;
    1293:     imat_i     = subc->i;
    1294:     imat_a     = subc->a;

    1296:     if (!allcolumns[i]) cmap_i = cmap[i];
    1297:     rmap_i = rmap[i];
    1298:     irow_i = irow[i];
    1299:     jmax   = nrow[i];
    1300:     for (PetscInt j = 0; j < jmax; j++) {
    1301:       if (allrows[i]) row = j;
    1302:       else row = irow_i[j];
    1303:       proc = row2proc_i[j];

    1305:       if (proc == rank) {
    1306:         row    = row - rstart;
    1307:         nzA    = a_i[row + 1] - a_i[row];
    1308:         nzB    = b_i[row + 1] - b_i[row];
    1309:         cworkA = a_j + a_i[row];
    1310:         cworkB = PetscSafePointerPlusOffset(b_j, b_i[row]);
    1311:         if (!ijonly) {
    1312:           vworkA = a_a + a_i[row] * bs2;
    1313:           vworkB = PetscSafePointerPlusOffset(b_a, b_i[row] * bs2);
    1314:         }

    1316:         if (allrows[i]) {
    1317:           row = row + rstart;
    1318:         } else {
    1319: #if defined(PETSC_USE_CTABLE)
    1320:           PetscCall(PetscHMapIGetWithDefault(rmap_i, row + rstart + 1, 0, &row));
    1321:           row--;

    1323:           PetscCheck(row >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "row not found in table");
    1324: #else
    1325:           row = rmap_i[row + rstart];
    1326: #endif
    1327:         }
    1328:         mat_i = imat_i[row];
    1329:         if (!ijonly) mat_a = PetscSafePointerPlusOffset(imat_a, mat_i * bs2);
    1330:         mat_j = PetscSafePointerPlusOffset(imat_j, mat_i);
    1331:         ilen  = imat_ilen[row];

    1333:         /* load the column indices for this row into cols*/
    1334:         if (!allcolumns[i]) {
    1335:           PetscInt l;

    1337:           for (l = 0; l < nzB; l++) {
    1338:             if ((ctmp = bmap[cworkB[l]]) < cstart) {
    1339: #if defined(PETSC_USE_CTABLE)
    1340:               PetscCall(PetscHMapIGetWithDefault(cmap_i, ctmp + 1, 0, &tcol));
    1341:               if (tcol) {
    1342: #else
    1343:               if ((tcol = cmap_i[ctmp])) {
    1344: #endif
    1345:                 *mat_j++ = tcol - 1;
    1346:                 PetscCall(PetscArraycpy(mat_a, vworkB + l * bs2, bs2));
    1347:                 mat_a += bs2;
    1348:                 ilen++;
    1349:               }
    1350:             } else break;
    1351:           }
    1352:           imark = l;
    1353:           for (PetscInt l = 0; l < nzA; l++) {
    1354: #if defined(PETSC_USE_CTABLE)
    1355:             PetscCall(PetscHMapIGetWithDefault(cmap_i, cstart + cworkA[l] + 1, 0, &tcol));
    1356:             if (tcol) {
    1357: #else
    1358:             if ((tcol = cmap_i[cstart + cworkA[l]])) {
    1359: #endif
    1360:               *mat_j++ = tcol - 1;
    1361:               if (!ijonly) {
    1362:                 PetscCall(PetscArraycpy(mat_a, vworkA + l * bs2, bs2));
    1363:                 mat_a += bs2;
    1364:               }
    1365:               ilen++;
    1366:             }
    1367:           }
    1368:           for (l = imark; l < nzB; l++) {
    1369: #if defined(PETSC_USE_CTABLE)
    1370:             PetscCall(PetscHMapIGetWithDefault(cmap_i, bmap[cworkB[l]] + 1, 0, &tcol));
    1371:             if (tcol) {
    1372: #else
    1373:             if ((tcol = cmap_i[bmap[cworkB[l]]])) {
    1374: #endif
    1375:               *mat_j++ = tcol - 1;
    1376:               if (!ijonly) {
    1377:                 PetscCall(PetscArraycpy(mat_a, vworkB + l * bs2, bs2));
    1378:                 mat_a += bs2;
    1379:               }
    1380:               ilen++;
    1381:             }
    1382:           }
    1383:         } else { /* allcolumns */
    1384:           PetscInt l;
    1385:           for (l = 0; l < nzB; l++) {
    1386:             if ((ctmp = bmap[cworkB[l]]) < cstart) {
    1387:               *mat_j++ = ctmp;
    1388:               PetscCall(PetscArraycpy(mat_a, vworkB + l * bs2, bs2));
    1389:               mat_a += bs2;
    1390:               ilen++;
    1391:             } else break;
    1392:           }
    1393:           imark = l;
    1394:           for (l = 0; l < nzA; l++) {
    1395:             *mat_j++ = cstart + cworkA[l];
    1396:             if (!ijonly) {
    1397:               PetscCall(PetscArraycpy(mat_a, vworkA + l * bs2, bs2));
    1398:               mat_a += bs2;
    1399:             }
    1400:             ilen++;
    1401:           }
    1402:           for (l = imark; l < nzB; l++) {
    1403:             *mat_j++ = bmap[cworkB[l]];
    1404:             if (!ijonly) {
    1405:               PetscCall(PetscArraycpy(mat_a, vworkB + l * bs2, bs2));
    1406:               mat_a += bs2;
    1407:             }
    1408:             ilen++;
    1409:           }
    1410:         }
    1411:         imat_ilen[row] = ilen;
    1412:       }
    1413:     }
    1414:   }

    1416:   /* Now assemble the off proc rows */
    1417:   if (!ijonly) PetscCallMPI(MPI_Waitall(nrqs, r_waits4, MPI_STATUSES_IGNORE));
    1418:   for (tmp2 = 0; tmp2 < nrqs; tmp2++) {
    1419:     sbuf1_i = sbuf1[pa[tmp2]];
    1420:     jmax    = sbuf1_i[0];
    1421:     ct1     = 2 * jmax + 1;
    1422:     ct2     = 0;
    1423:     rbuf2_i = rbuf2[tmp2];
    1424:     rbuf3_i = rbuf3[tmp2];
    1425:     if (!ijonly) rbuf4_i = rbuf4[tmp2];
    1426:     for (PetscInt j = 1; j <= jmax; j++) {
    1427:       is_no  = sbuf1_i[2 * j - 1];
    1428:       rmap_i = rmap[is_no];
    1429:       if (!allcolumns[is_no]) cmap_i = cmap[is_no];
    1430:       subc      = (Mat_SeqBAIJ *)submats[is_no]->data;
    1431:       imat_ilen = subc->ilen;
    1432:       imat_j    = subc->j;
    1433:       imat_i    = subc->i;
    1434:       if (!ijonly) imat_a = subc->a;
    1435:       max1 = sbuf1_i[2 * j];
    1436:       for (PetscInt k = 0; k < max1; k++, ct1++) { /* for each recved block row */
    1437:         row = sbuf1_i[ct1];

    1439:         if (allrows[is_no]) {
    1440:           row = sbuf1_i[ct1];
    1441:         } else {
    1442: #if defined(PETSC_USE_CTABLE)
    1443:           PetscCall(PetscHMapIGetWithDefault(rmap_i, row + 1, 0, &row));
    1444:           row--;
    1445:           PetscCheck(row >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "row not found in table");
    1446: #else
    1447:           row = rmap_i[row];
    1448: #endif
    1449:         }
    1450:         ilen  = imat_ilen[row];
    1451:         mat_i = imat_i[row];
    1452:         if (!ijonly) mat_a = imat_a + mat_i * bs2;
    1453:         mat_j = imat_j + mat_i;
    1454:         max2  = rbuf2_i[ct1];
    1455:         if (!allcolumns[is_no]) {
    1456:           for (PetscInt l = 0; l < max2; l++, ct2++) {
    1457: #if defined(PETSC_USE_CTABLE)
    1458:             PetscCall(PetscHMapIGetWithDefault(cmap_i, rbuf3_i[ct2] + 1, 0, &tcol));
    1459: #else
    1460:             tcol = cmap_i[rbuf3_i[ct2]];
    1461: #endif
    1462:             if (tcol) {
    1463:               *mat_j++ = tcol - 1;
    1464:               if (!ijonly) {
    1465:                 PetscCall(PetscArraycpy(mat_a, rbuf4_i + ct2 * bs2, bs2));
    1466:                 mat_a += bs2;
    1467:               }
    1468:               ilen++;
    1469:             }
    1470:           }
    1471:         } else { /* allcolumns */
    1472:           for (PetscInt l = 0; l < max2; l++, ct2++) {
    1473:             *mat_j++ = rbuf3_i[ct2]; /* same global column index of C */
    1474:             if (!ijonly) {
    1475:               PetscCall(PetscArraycpy(mat_a, rbuf4_i + ct2 * bs2, bs2));
    1476:               mat_a += bs2;
    1477:             }
    1478:             ilen++;
    1479:           }
    1480:         }
    1481:         imat_ilen[row] = ilen;
    1482:       }
    1483:     }
    1484:   }

    1486:   if (!iscsorted) { /* sort column indices of the rows */
    1487:     MatScalar *work;

    1489:     PetscCall(PetscMalloc1(bs2, &work));
    1490:     for (PetscInt i = 0; i < ismax; i++) {
    1491:       subc      = (Mat_SeqBAIJ *)submats[i]->data;
    1492:       imat_ilen = subc->ilen;
    1493:       imat_j    = subc->j;
    1494:       imat_i    = subc->i;
    1495:       if (!ijonly) imat_a = subc->a;
    1496:       if (allcolumns[i]) continue;

    1498:       jmax = nrow[i];
    1499:       for (PetscInt j = 0; j < jmax; j++) {
    1500:         mat_i = imat_i[j];
    1501:         mat_j = imat_j + mat_i;
    1502:         ilen  = imat_ilen[j];
    1503:         if (ijonly) {
    1504:           PetscCall(PetscSortInt(ilen, mat_j));
    1505:         } else {
    1506:           mat_a = imat_a + mat_i * bs2;
    1507:           PetscCall(PetscSortIntWithDataArray(ilen, mat_j, mat_a, bs2 * sizeof(MatScalar), work));
    1508:         }
    1509:       }
    1510:     }
    1511:     PetscCall(PetscFree(work));
    1512:   }

    1514:   if (!ijonly) {
    1515:     PetscCall(PetscFree(r_waits4));
    1516:     PetscCallMPI(MPI_Waitall(nrqr, s_waits4, MPI_STATUSES_IGNORE));
    1517:     PetscCall(PetscFree(s_waits4));
    1518:   }

    1520:   /* Restore the indices */
    1521:   for (PetscInt i = 0; i < ismax; i++) {
    1522:     if (!allrows[i]) PetscCall(ISRestoreIndices(isrow[i], irow + i));
    1523:     if (!allcolumns[i]) PetscCall(ISRestoreIndices(iscol[i], icol + i));
    1524:   }

    1526:   for (PetscInt i = 0; i < ismax; i++) {
    1527:     PetscCall(MatAssemblyBegin(submats[i], MAT_FINAL_ASSEMBLY));
    1528:     PetscCall(MatAssemblyEnd(submats[i], MAT_FINAL_ASSEMBLY));
    1529:   }

    1531:   PetscCall(PetscFree5(*(PetscInt ***)&irow, *(PetscInt ***)&icol, nrow, ncol, issorted));
    1532:   PetscCall(PetscFree5(row2proc, cmap, rmap, allcolumns, allrows));

    1534:   if (!ijonly) {
    1535:     if (sbuf_aa) {
    1536:       PetscCall(PetscFree(sbuf_aa[0]));
    1537:       PetscCall(PetscFree(sbuf_aa));
    1538:     }

    1540:     for (PetscMPIInt i = 0; i < nrqs; ++i) PetscCall(PetscFree(rbuf4[i]));
    1541:     PetscCall(PetscFree(rbuf4));
    1542:   }
    1543:   c->ijonly = PETSC_FALSE; /* set back to the default */
    1544:   PetscFunctionReturn(PETSC_SUCCESS);
    1545: }