Actual source code: mpiptap.c

  1: #define PETSCMAT_DLL

  3: /*
  4:   Defines projective product routines where A is a MPIAIJ matrix
  5:           C = P^T * A * P
  6: */

 8:  #include src/mat/impls/aij/seq/aij.h
 9:  #include src/mat/utils/freespace.h
 10:  #include src/mat/impls/aij/mpi/mpiaij.h
 11:  #include petscbt.h

 13: EXTERN PetscErrorCode MatDestroy_MPIAIJ(Mat);
 16: PetscErrorCode  MatDestroy_MPIAIJ_MatPtAP(Mat A)
 17: {
 18:   PetscErrorCode       ierr;
 19:   Mat_Merge_SeqsToMPI  *merge;
 20:   PetscContainer       container;

 23:   PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject *)&container);
 24:   if (container) {
 25:     PetscContainerGetPointer(container,(void **)&merge);
 26:     PetscFree(merge->id_r);
 27:     PetscFree(merge->len_s);
 28:     PetscFree(merge->len_r);
 29:     PetscFree(merge->bi);
 30:     PetscFree(merge->bj);
 31:     PetscFree(merge->buf_ri);
 32:     PetscFree(merge->buf_rj);
 33:     PetscFree(merge->coi);
 34:     PetscFree(merge->coj);
 35:     PetscFree(merge->owners_co);
 36:     PetscFree(merge->rowmap.range);
 37: 
 38:     PetscContainerDestroy(container);
 39:     PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);
 40:   }
 41:   merge->MatDestroy(A);
 42:   PetscFree(merge);
 43:   return(0);
 44: }

 48: PetscErrorCode MatDuplicate_MPIAIJ_MatPtAP(Mat A, MatDuplicateOption op, Mat *M) {
 49:   PetscErrorCode       ierr;
 50:   Mat_Merge_SeqsToMPI  *merge;
 51:   PetscContainer       container;

 54:   PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject *)&container);
 55:   if (container) {
 56:     PetscContainerGetPointer(container,(void **)&merge);
 57:   } else {
 58:     SETERRQ(PETSC_ERR_PLIB,"Container does not exit");
 59:   }
 60:   (*merge->MatDuplicate)(A,op,M);
 61:   (*M)->ops->destroy   = merge->MatDestroy;   /* =MatDestroy_MPIAIJ, *M doesn't duplicate A's container! */
 62:   (*M)->ops->duplicate = merge->MatDuplicate; /* =MatDuplicate_ MPIAIJ */
 63:   return(0);
 64: }

 68: PetscErrorCode MatPtAPSymbolic_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat *C)
 69: {

 73:   if (!P->ops->ptapsymbolic_mpiaij) {
 74:     SETERRQ2(PETSC_ERR_SUP,"Not implemented for A=%s and P=%s",A->type_name,P->type_name);
 75:   }
 76:   (*P->ops->ptapsymbolic_mpiaij)(A,P,fill,C);
 77:   return(0);
 78: }

 82: PetscErrorCode MatPtAPNumeric_MPIAIJ(Mat A,Mat P,Mat C)
 83: {

 87:   if (!P->ops->ptapnumeric_mpiaij) {
 88:     SETERRQ2(PETSC_ERR_SUP,"Not implemented for A=%s and P=%s",A->type_name,P->type_name);
 89:   }
 90:   (*P->ops->ptapnumeric_mpiaij)(A,P,C);
 91:   return(0);
 92: }

 96: PetscErrorCode MatPtAPSymbolic_MPIAIJ_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat *C)
 97: {
 98:   PetscErrorCode       ierr;
 99:   Mat                  B_mpi;
100:   Mat_MatMatMultMPI    *ap;
101:   PetscContainer       container;
102:   PetscFreeSpaceList   free_space=PETSC_NULL,current_space=PETSC_NULL;
103:   Mat_MPIAIJ           *a=(Mat_MPIAIJ*)A->data,*p=(Mat_MPIAIJ*)P->data;
104:   Mat_SeqAIJ           *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data;
105:   Mat_SeqAIJ           *p_loc,*p_oth;
106:   PetscInt             *pi_loc,*pj_loc,*pi_oth,*pj_oth,*pdti,*pdtj,*poti,*potj,*ptJ;
107:   PetscInt             *adi=ad->i,*adj=ad->j,*aoi=ao->i,*aoj=ao->j,nnz;
108:   PetscInt             nlnk,*lnk,*owners_co,*coi,*coj,i,k,pnz,row;
109:   PetscInt             am=A->rmap.n,pN=P->cmap.N,pn=P->cmap.n;
110:   PetscBT              lnkbt;
111:   MPI_Comm             comm=A->comm;
112:   PetscMPIInt          size,rank,tag,*len_si,*len_s,*len_ri;
113:   PetscInt             **buf_rj,**buf_ri,**buf_ri_k;
114:   PetscInt             len,proc,*dnz,*onz,*owners;
115:   PetscInt             nzi,*bi,*bj;
116:   PetscInt             nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextci;
117:   MPI_Request          *swaits,*rwaits;
118:   MPI_Status           *sstatus,rstatus;
119:   Mat_Merge_SeqsToMPI  *merge;
120:   PetscInt             *api,*apj,*Jptr,apnz,*prmap=p->garray,pon,nspacedouble=0;
121:   PetscMPIInt          j;

124:   MPI_Comm_size(comm,&size);
125:   MPI_Comm_rank(comm,&rank);

127:   /* destroy the container 'Mat_MatMatMultMPI' in case that P is attached to it */
128:   PetscObjectQuery((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject *)&container);
129:   if (container) {
130:     /* reset functions */
131:     PetscContainerGetPointer(container,(void **)&ap);
132:     P->ops->destroy = ap->MatDestroy;
133:     P->ops->duplicate = ap->MatDuplicate;
134:     /* destroy container and contents */
135:     PetscContainerDestroy(container);
136:     PetscObjectCompose((PetscObject)P,"Mat_MatMatMultMPI",0);
137:   }

139:   /* create the container 'Mat_MatMatMultMPI' and attach it to P */
140:   PetscNew(Mat_MatMatMultMPI,&ap);
141:   ap->abi=PETSC_NULL; ap->abj=PETSC_NULL;
142:   ap->abnz_max = 0;

144:   PetscContainerCreate(PETSC_COMM_SELF,&container);
145:   PetscContainerSetPointer(container,ap);
146:   PetscObjectCompose((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject)container);
147:   ap->MatDestroy  = P->ops->destroy;
148:   P->ops->destroy = MatDestroy_MPIAIJ_MatMatMult;
149:   ap->reuse       = MAT_INITIAL_MATRIX;
150:   PetscContainerSetUserDestroy(container,PetscContainerDestroy_Mat_MatMatMultMPI);

152:   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
153:   MatGetBrowsOfAoCols(A,P,MAT_INITIAL_MATRIX,&ap->startsj,&ap->bufa,&ap->B_oth);
154:   /* get P_loc by taking all local rows of P */
155:   MatGetLocalMat(P,MAT_INITIAL_MATRIX,&ap->B_loc);

157:   p_loc = (Mat_SeqAIJ*)(ap->B_loc)->data;
158:   p_oth = (Mat_SeqAIJ*)(ap->B_oth)->data;
159:   pi_loc = p_loc->i; pj_loc = p_loc->j;
160:   pi_oth = p_oth->i; pj_oth = p_oth->j;

162:   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
163:   /*-------------------------------------------------------------------*/
164:   PetscMalloc((am+2)*sizeof(PetscInt),&api);
165:   ap->abi = api;
166:   api[0] = 0;

168:   /* create and initialize a linked list */
169:   nlnk = pN+1;
170:   PetscLLCreate(pN,pN,nlnk,lnk,lnkbt);

172:   /* Initial FreeSpace size is fill*nnz(A) */
173:   PetscFreeSpaceGet((PetscInt)(fill*(adi[am]+aoi[am])),&free_space);
174:   current_space = free_space;

176:   for (i=0;i<am;i++) {
177:     apnz = 0;
178:     /* diagonal portion of A */
179:     nzi = adi[i+1] - adi[i];
180:     for (j=0; j<nzi; j++){
181:       row = *adj++;
182:       pnz = pi_loc[row+1] - pi_loc[row];
183:       Jptr  = pj_loc + pi_loc[row];
184:       /* add non-zero cols of P into the sorted linked list lnk */
185:       PetscLLAdd(pnz,Jptr,pN,nlnk,lnk,lnkbt);
186:       apnz += nlnk;
187:     }
188:     /* off-diagonal portion of A */
189:     nzi = aoi[i+1] - aoi[i];
190:     for (j=0; j<nzi; j++){
191:       row = *aoj++;
192:       pnz = pi_oth[row+1] - pi_oth[row];
193:       Jptr  = pj_oth + pi_oth[row];
194:       PetscLLAdd(pnz,Jptr,pN,nlnk,lnk,lnkbt);
195:       apnz += nlnk;
196:     }

198:     api[i+1] = api[i] + apnz;
199:     if (ap->abnz_max < apnz) ap->abnz_max = apnz;

201:     /* if free space is not available, double the total space in the list */
202:     if (current_space->local_remaining<apnz) {
203:       PetscFreeSpaceGet(current_space->total_array_size,&current_space);
204:       nspacedouble++;
205:     }

207:     /* Copy data into free space, then initialize lnk */
208:     PetscLLClean(pN,pN,apnz,lnk,current_space->array,lnkbt);
209:     current_space->array           += apnz;
210:     current_space->local_used      += apnz;
211:     current_space->local_remaining -= apnz;
212:   }
213:   /* Allocate space for apj, initialize apj, and */
214:   /* destroy list of free space and other temporary array(s) */
215:   PetscMalloc((api[am]+1)*sizeof(PetscInt),&ap->abj);
216:   apj = ap->abj;
217:   PetscFreeSpaceContiguous(&free_space,ap->abj);

219:   /* determine symbolic Co=(p->B)^T*AP - send to others */
220:   /*----------------------------------------------------*/
221:   MatGetSymbolicTranspose_SeqAIJ(p->B,&poti,&potj);

223:   /* then, compute symbolic Co = (p->B)^T*AP */
224:   pon = (p->B)->cmap.n; /* total num of rows to be sent to other processors 
225:                          >= (num of nonzero rows of C_seq) - pn */
226:   PetscMalloc((pon+1)*sizeof(PetscInt),&coi);
227:   coi[0] = 0;

229:   /* set initial free space to be 3*pon*max( nnz(AP) per row) */
230:   nnz           = 3*pon*ap->abnz_max + 1;
231:   PetscFreeSpaceGet(nnz,&free_space);
232:   current_space = free_space;

234:   for (i=0; i<pon; i++) {
235:     nnz  = 0;
236:     pnz = poti[i+1] - poti[i];
237:     j     = pnz;
238:     ptJ   = potj + poti[i+1];
239:     while (j){/* assume cols are almost in increasing order, starting from its end saves computation */
240:       j--; ptJ--;
241:       row  = *ptJ; /* row of AP == col of Pot */
242:       apnz = api[row+1] - api[row];
243:       Jptr   = apj + api[row];
244:       /* add non-zero cols of AP into the sorted linked list lnk */
245:       PetscLLAdd(apnz,Jptr,pN,nlnk,lnk,lnkbt);
246:       nnz += nlnk;
247:     }

249:     /* If free space is not available, double the total space in the list */
250:     if (current_space->local_remaining<nnz) {
251:       PetscFreeSpaceGet(current_space->total_array_size,&current_space);
252:     }

254:     /* Copy data into free space, and zero out denserows */
255:     PetscLLClean(pN,pN,nnz,lnk,current_space->array,lnkbt);
256:     current_space->array           += nnz;
257:     current_space->local_used      += nnz;
258:     current_space->local_remaining -= nnz;
259:     coi[i+1] = coi[i] + nnz;
260:   }
261:   PetscMalloc((coi[pon]+1)*sizeof(PetscInt),&coj);
262:   PetscFreeSpaceContiguous(&free_space,coj);
263:   MatRestoreSymbolicTranspose_SeqAIJ(p->B,&poti,&potj);

265:   /* send j-array (coj) of Co to other processors */
266:   /*----------------------------------------------*/
267:   /* determine row ownership */
268:   PetscNew(Mat_Merge_SeqsToMPI,&merge);
269:   PetscMapInitialize(comm,&merge->rowmap);
270:   merge->rowmap.n = pn;
271:   merge->rowmap.N = PETSC_DECIDE;
272:   merge->rowmap.bs = 1;
273:   PetscMapSetUp(&merge->rowmap);
274:   owners = merge->rowmap.range;

276:   /* determine the number of messages to send, their lengths */
277:   PetscMalloc(size*sizeof(PetscMPIInt),&len_si);
278:   PetscMemzero(len_si,size*sizeof(PetscMPIInt));
279:   PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);
280:   len_s = merge->len_s;
281:   merge->nsend = 0;
282: 
283:   PetscMalloc((size+2)*sizeof(PetscInt),&owners_co);
284:   PetscMemzero(len_s,size*sizeof(PetscMPIInt));

286:   proc = 0;
287:   for (i=0; i<pon; i++){
288:     while (prmap[i] >= owners[proc+1]) proc++;
289:     len_si[proc]++;  /* num of rows in Co to be sent to [proc] */
290:     len_s[proc] += coi[i+1] - coi[i];
291:   }

293:   len   = 0;  /* max length of buf_si[] */
294:   owners_co[0] = 0;
295:   for (proc=0; proc<size; proc++){
296:     owners_co[proc+1] = owners_co[proc] + len_si[proc];
297:     if (len_si[proc]){
298:       merge->nsend++;
299:       len_si[proc] = 2*(len_si[proc] + 1);
300:       len += len_si[proc];
301:     }
302:   }

304:   /* determine the number and length of messages to receive for coi and coj  */
305:   PetscGatherNumberOfMessages(comm,PETSC_NULL,len_s,&merge->nrecv);
306:   PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);

308:   /* post the Irecv and Isend of coj */
309:   PetscCommGetNewTag(comm,&tag);
310:   PetscPostIrecvInt(comm,tag,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rwaits);

312:   PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&swaits);

314:   for (proc=0, k=0; proc<size; proc++){
315:     if (!len_s[proc]) continue;
316:     i = owners_co[proc];
317:     MPI_Isend(coj+coi[i],len_s[proc],MPIU_INT,proc,tag,comm,swaits+k);
318:     k++;
319:   }

321:   /* receives and sends of coj are complete */
322:   PetscMalloc(size*sizeof(MPI_Status),&sstatus);
323:   i = merge->nrecv;
324:   while (i--) {
325:     MPI_Waitany(merge->nrecv,rwaits,&j,&rstatus);
326:   }
327:   PetscFree(rwaits);
328:   if (merge->nsend) {MPI_Waitall(merge->nsend,swaits,sstatus);}
329: 
330:   /* send and recv coi */
331:   /*-------------------*/
332:   PetscPostIrecvInt(comm,tag,merge->nrecv,merge->id_r,len_ri,&buf_ri,&rwaits);
333: 
334:   PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);
335:   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
336:   for (proc=0,k=0; proc<size; proc++){
337:     if (!len_s[proc]) continue;
338:     /* form outgoing message for i-structure: 
339:          buf_si[0]:                 nrows to be sent
340:                [1:nrows]:           row index (global)
341:                [nrows+1:2*nrows+1]: i-structure index
342:     */
343:     /*-------------------------------------------*/
344:     nrows = len_si[proc]/2 - 1;
345:     buf_si_i    = buf_si + nrows+1;
346:     buf_si[0]   = nrows;
347:     buf_si_i[0] = 0;
348:     nrows = 0;
349:     for (i=owners_co[proc]; i<owners_co[proc+1]; i++){
350:       nzi = coi[i+1] - coi[i];
351:       buf_si_i[nrows+1] = buf_si_i[nrows] + nzi; /* i-structure */
352:       buf_si[nrows+1] =prmap[i] -owners[proc]; /* local row index */
353:       nrows++;
354:     }
355:     MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tag,comm,swaits+k);
356:     k++;
357:     buf_si += len_si[proc];
358:   }
359:   i = merge->nrecv;
360:   while (i--) {
361:     MPI_Waitany(merge->nrecv,rwaits,&j,&rstatus);
362:   }
363:   PetscFree(rwaits);
364:   if (merge->nsend) {MPI_Waitall(merge->nsend,swaits,sstatus);}
365:   /*
366:   PetscInfo2(A,"nsend: %d, nrecv: %d\n",merge->nsend,merge->nrecv);
367:   for (i=0; i<merge->nrecv; i++){
368:     PetscInfo3(A,"recv len_ri=%d, len_rj=%d from [%d]\n",len_ri[i],merge->len_r[i],merge->id_r[i]);
369:   }
370:   */
371:   PetscFree(len_si);
372:   PetscFree(len_ri);
373:   PetscFree(swaits);
374:   PetscFree(sstatus);
375:   PetscFree(buf_s);

377:   /* compute the local portion of C (mpi mat) */
378:   /*------------------------------------------*/
379:   MatGetSymbolicTranspose_SeqAIJ(p->A,&pdti,&pdtj);

381:   /* allocate bi array and free space for accumulating nonzero column info */
382:   PetscMalloc((pn+1)*sizeof(PetscInt),&bi);
383:   bi[0] = 0;
384: 
385:   /* set initial free space to be 3*pn*max( nnz(AP) per row) */
386:   nnz           = 3*pn*ap->abnz_max + 1;
387:   PetscFreeSpaceGet(nnz,&free_space);
388:   current_space = free_space;

390:   PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);
391:   nextrow = buf_ri_k + merge->nrecv;
392:   nextci  = nextrow + merge->nrecv;
393:   for (k=0; k<merge->nrecv; k++){
394:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
395:     nrows       = *buf_ri_k[k];
396:     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
397:     nextci[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
398:   }
399:   MatPreallocateInitialize(comm,pn,pn,dnz,onz);
400:   for (i=0; i<pn; i++) {
401:     /* add pdt[i,:]*AP into lnk */
402:     nnz = 0;
403:     pnz  = pdti[i+1] - pdti[i];
404:     j    = pnz;
405:     ptJ  = pdtj + pdti[i+1];
406:     while (j){/* assume cols are almost in increasing order, starting from its end saves computation */
407:       j--; ptJ--;
408:       row  = *ptJ; /* row of AP == col of Pt */
409:       apnz = api[row+1] - api[row];
410:       Jptr   = apj + api[row];
411:       /* add non-zero cols of AP into the sorted linked list lnk */
412:       PetscLLAdd(apnz,Jptr,pN,nlnk,lnk,lnkbt);
413:       nnz += nlnk;
414:     }
415:     /* add received col data into lnk */
416:     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
417:       if (i == *nextrow[k]) { /* i-th row */
418:         nzi = *(nextci[k]+1) - *nextci[k];
419:         Jptr  = buf_rj[k] + *nextci[k];
420:         PetscLLAdd(nzi,Jptr,pN,nlnk,lnk,lnkbt);
421:         nnz += nlnk;
422:         nextrow[k]++; nextci[k]++;
423:       }
424:     }

426:     /* if free space is not available, make more free space */
427:     if (current_space->local_remaining<nnz) {
428:       PetscFreeSpaceGet(current_space->total_array_size,&current_space);
429:     }
430:     /* copy data into free space, then initialize lnk */
431:     PetscLLClean(pN,pN,nnz,lnk,current_space->array,lnkbt);
432:     MatPreallocateSet(i+owners[rank],nnz,current_space->array,dnz,onz);
433:     current_space->array           += nnz;
434:     current_space->local_used      += nnz;
435:     current_space->local_remaining -= nnz;
436:     bi[i+1] = bi[i] + nnz;
437:   }
438:   MatRestoreSymbolicTranspose_SeqAIJ(p->A,&pdti,&pdtj);
439:   PetscFree(buf_ri_k);

441:   PetscMalloc((bi[pn]+1)*sizeof(PetscInt),&bj);
442:   PetscFreeSpaceContiguous(&free_space,bj);
443:   PetscLLDestroy(lnk,lnkbt);

445:   /* create symbolic parallel matrix B_mpi */
446:   /*---------------------------------------*/
447:   MatCreate(comm,&B_mpi);
448:   MatSetSizes(B_mpi,pn,pn,PETSC_DETERMINE,PETSC_DETERMINE);
449:   MatSetType(B_mpi,MATMPIAIJ);
450:   MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);
451:   MatPreallocateFinalize(dnz,onz);

453:   merge->bi            = bi;
454:   merge->bj            = bj;
455:   merge->coi           = coi;
456:   merge->coj           = coj;
457:   merge->buf_ri        = buf_ri;
458:   merge->buf_rj        = buf_rj;
459:   merge->owners_co     = owners_co;
460:   merge->MatDestroy    = B_mpi->ops->destroy;
461:   merge->MatDuplicate  = B_mpi->ops->duplicate;

463:   /* B_mpi is not ready for use - assembly will be done by MatPtAPNumeric() */
464:   B_mpi->assembled     = PETSC_FALSE;
465:   B_mpi->ops->destroy  = MatDestroy_MPIAIJ_MatPtAP;
466:   B_mpi->ops->duplicate = MatDuplicate_MPIAIJ_MatPtAP;

468:   /* attach the supporting struct to B_mpi for reuse */
469:   PetscContainerCreate(PETSC_COMM_SELF,&container);
470:   PetscContainerSetPointer(container,merge);
471:   PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);
472:   *C = B_mpi;
473: #if defined(PETSC_USE_INFO)
474:   if (bi[pn] != 0) {
475:     PetscReal afill = ((PetscReal)bi[pn])/(adi[am]+aoi[am]);
476:     if (afill < 1.0) afill = 1.0;
477:     PetscInfo3(B_mpi,"Reallocs %D; Fill ratio: given %G needed %G when computing A*P.\n",nspacedouble,fill,afill);
478:     PetscInfo1(B_mpi,"Use MatPtAP(A,P,MatReuse,%G,&C) for best performance.\n",afill);
479:   } else {
480:     PetscInfo(B_mpi,"Empty matrix product\n");
481:   }
482: #endif
483:   return(0);
484: }

488: PetscErrorCode MatPtAPNumeric_MPIAIJ_MPIAIJ(Mat A,Mat P,Mat C)
489: {
490:   PetscErrorCode       ierr;
491:   Mat_Merge_SeqsToMPI  *merge;
492:   Mat_MatMatMultMPI    *ap;
493:   PetscContainer cont_merge,cont_ptap;
494:   Mat_MPIAIJ           *a=(Mat_MPIAIJ*)A->data,*p=(Mat_MPIAIJ*)P->data;
495:   Mat_SeqAIJ           *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data;
496:   Mat_SeqAIJ           *pd=(Mat_SeqAIJ*)(p->A)->data,*po=(Mat_SeqAIJ*)(p->B)->data;
497:   Mat_SeqAIJ           *p_loc,*p_oth;
498:   PetscInt             *adi=ad->i,*aoi=ao->i,*adj=ad->j,*aoj=ao->j,*apJ,nextp,flops=0;
499:   PetscInt             *pi_loc,*pj_loc,*pi_oth,*pj_oth,*pJ,*pj;
500:   PetscInt             i,j,k,anz,pnz,apnz,nextap,row,*cj;
501:   MatScalar            *ada=ad->a,*aoa=ao->a,*apa,*pa,*ca,*pa_loc,*pa_oth;
502:   PetscInt             am=A->rmap.n,cm=C->rmap.n,pon=(p->B)->cmap.n;
503:   MPI_Comm             comm=C->comm;
504:   PetscMPIInt          size,rank,taga,*len_s;
505:   PetscInt             *owners,proc,nrows,**buf_ri_k,**nextrow,**nextci;
506:   PetscInt             **buf_ri,**buf_rj;
507:   PetscInt             cnz=0,*bj_i,*bi,*bj,bnz,nextcj; /* bi,bj,ba: local array of C(mpi mat) */
508:   MPI_Request          *s_waits,*r_waits;
509:   MPI_Status           *status;
510:   MatScalar            **abuf_r,*ba_i,*pA,*coa,*ba;
511:   PetscInt             *api,*apj,*coi,*coj;
512:   PetscInt             *poJ=po->j,*pdJ=pd->j,pcstart=P->cmap.rstart,pcend=P->cmap.rend;

515:   MPI_Comm_size(comm,&size);
516:   MPI_Comm_rank(comm,&rank);

518:   PetscObjectQuery((PetscObject)C,"MatMergeSeqsToMPI",(PetscObject *)&cont_merge);
519:   if (cont_merge) {
520:     PetscContainerGetPointer(cont_merge,(void **)&merge);
521:   } else {
522:     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix C does not posses an object container");
523:   }

525:   PetscObjectQuery((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject *)&cont_ptap);
526:   if (cont_ptap) {
527:     PetscContainerGetPointer(cont_ptap,(void **)&ap);
528:     if (ap->reuse == MAT_INITIAL_MATRIX){
529:       ap->reuse = MAT_REUSE_MATRIX;
530:     } else { /* update numerical values of P_oth and P_loc */
531:       MatGetBrowsOfAoCols(A,P,MAT_REUSE_MATRIX,&ap->startsj,&ap->bufa,&ap->B_oth);
532:       MatGetLocalMat(P,MAT_REUSE_MATRIX,&ap->B_loc);
533:     }
534:   } else {
535:     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
536:   }

538:   /* get data from symbolic products */
539:   p_loc = (Mat_SeqAIJ*)(ap->B_loc)->data;
540:   p_oth = (Mat_SeqAIJ*)(ap->B_oth)->data;
541:   pi_loc=p_loc->i; pj_loc=p_loc->j; pJ=pj_loc; pa_loc=p_loc->a,pA=pa_loc;
542:   pi_oth=p_oth->i; pj_oth=p_oth->j; pa_oth=p_oth->a;
543: 
544:   coi = merge->coi; coj = merge->coj;
545:   PetscMalloc((coi[pon]+1)*sizeof(MatScalar),&coa);
546:   PetscMemzero(coa,coi[pon]*sizeof(MatScalar));

548:   bi     = merge->bi; bj = merge->bj;
549:   owners = merge->rowmap.range;
550:   PetscMalloc((bi[cm]+1)*sizeof(MatScalar),&ba);
551:   PetscMemzero(ba,bi[cm]*sizeof(MatScalar));

553:   /* get data from symbolic A*P */
554:   PetscMalloc((ap->abnz_max+1)*sizeof(MatScalar),&apa);
555:   PetscMemzero(apa,ap->abnz_max*sizeof(MatScalar));

557:   /* compute numeric C_seq=P_loc^T*A_loc*P */
558:   api = ap->abi; apj = ap->abj;
559:   for (i=0;i<am;i++) {
560:     /* form i-th sparse row of A*P */
561:     apnz = api[i+1] - api[i];
562:     apJ  = apj + api[i];
563:     /* diagonal portion of A */
564:     anz  = adi[i+1] - adi[i];
565:     for (j=0;j<anz;j++) {
566:       row = *adj++;
567:       pnz = pi_loc[row+1] - pi_loc[row];
568:       pj  = pj_loc + pi_loc[row];
569:       pa  = pa_loc + pi_loc[row];
570:       nextp = 0;
571:       for (k=0; nextp<pnz; k++) {
572:         if (apJ[k] == pj[nextp]) { /* col of AP == col of P */
573:           apa[k] += (*ada)*pa[nextp++];
574:         }
575:       }
576:       flops += 2*pnz;
577:       ada++;
578:     }
579:     /* off-diagonal portion of A */
580:     anz  = aoi[i+1] - aoi[i];
581:     for (j=0; j<anz; j++) {
582:       row = *aoj++;
583:       pnz = pi_oth[row+1] - pi_oth[row];
584:       pj  = pj_oth + pi_oth[row];
585:       pa  = pa_oth + pi_oth[row];
586:       nextp = 0;
587:       for (k=0; nextp<pnz; k++) {
588:         if (apJ[k] == pj[nextp]) { /* col of AP == col of P */
589:           apa[k] += (*aoa)*pa[nextp++];
590:         }
591:       }
592:       flops += 2*pnz;
593:       aoa++;
594:     }

596:     /* Compute P_loc[i,:]^T*AP[i,:] using outer product */
597:     pnz = pi_loc[i+1] - pi_loc[i];
598:     for (j=0; j<pnz; j++) {
599:       nextap = 0;
600:       row    = *pJ++; /* global index */
601:       if (row < pcstart || row >=pcend) { /* put the value into Co */
602:         cj  = coj + coi[*poJ];
603:         ca  = coa + coi[*poJ++];
604:       } else {                            /* put the value into Cd */
605:         cj   = bj + bi[*pdJ];
606:         ca   = ba + bi[*pdJ++];
607:       }
608:       for (k=0; nextap<apnz; k++) {
609:         if (cj[k]==apJ[nextap]) ca[k] += (*pA)*apa[nextap++];
610:       }
611:       flops += 2*apnz;
612:       pA++;
613:     }

615:     /* zero the current row info for A*P */
616:     PetscMemzero(apa,apnz*sizeof(MatScalar));
617:   }
618:   PetscFree(apa);
619: 
620:   /* send and recv matrix values */
621:   /*-----------------------------*/
622:   buf_ri = merge->buf_ri;
623:   buf_rj = merge->buf_rj;
624:   len_s  = merge->len_s;
625:   PetscCommGetNewTag(comm,&taga);
626:   PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);

628:   PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);
629:   for (proc=0,k=0; proc<size; proc++){
630:     if (!len_s[proc]) continue;
631:     i = merge->owners_co[proc];
632:     MPI_Isend(coa+coi[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);
633:     k++;
634:   }
635:   PetscMalloc(size*sizeof(MPI_Status),&status);
636:   if (merge->nrecv) {MPI_Waitall(merge->nrecv,r_waits,status);}
637:   if (merge->nsend) {MPI_Waitall(merge->nsend,s_waits,status);}
638:   PetscFree(status);

640:   PetscFree(s_waits);
641:   PetscFree(r_waits);
642:   PetscFree(coa);

644:   /* insert local and received values into C */
645:   /*-----------------------------------------*/
646:   PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);
647:   nextrow   = buf_ri_k + merge->nrecv;
648:   nextci = nextrow + merge->nrecv;

650:   for (k=0; k<merge->nrecv; k++){
651:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
652:     nrows       = *(buf_ri_k[k]);
653:     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
654:     nextci[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
655:   }

657:   for (i=0; i<cm; i++) {
658:     row = owners[rank] + i; /* global row index of C_seq */
659:     bj_i = bj + bi[i];  /* col indices of the i-th row of C */
660:     ba_i = ba + bi[i];
661:     bnz  = bi[i+1] - bi[i];
662:     /* add received vals into ba */
663:     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
664:       /* i-th row */
665:       if (i == *nextrow[k]) {
666:         cnz = *(nextci[k]+1) - *nextci[k];
667:         cj  = buf_rj[k] + *(nextci[k]);
668:         ca  = abuf_r[k] + *(nextci[k]);
669:         nextcj = 0;
670:         for (j=0; nextcj<cnz; j++){
671:           if (bj_i[j] == cj[nextcj]){ /* bcol == ccol */
672:             ba_i[j] += ca[nextcj++];
673:           }
674:         }
675:         nextrow[k]++; nextci[k]++;
676:       }
677:     }
678:     MatSetValues(C,1,&row,bnz,bj_i,ba_i,INSERT_VALUES);
679:     flops += 2*cnz;
680:   }
681:   MatSetOption(C,MAT_COLUMNS_SORTED); /* -cause delay? */
682:   MatSetBlockSize(C,1);
683:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
684:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);

686:   PetscFree(ba);
687:   PetscFree(abuf_r);
688:   PetscFree(buf_ri_k);
689:   PetscLogFlops(flops);
690:   return(0);
691: }