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

 15: PetscErrorCode MatPtAPSymbolic_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat *C)
 16: {

 20:   if (!P->ops->ptapsymbolic_mpiaij) {
 21:     SETERRQ2(PETSC_ERR_SUP,"Not implemented for A=%s and P=%s",A->type_name,P->type_name);
 22:   }
 23:   (*P->ops->ptapsymbolic_mpiaij)(A,P,fill,C);
 24:   return(0);
 25: }

 29: PetscErrorCode MatPtAPNumeric_MPIAIJ(Mat A,Mat P,Mat C)
 30: {

 34:   if (!P->ops->ptapnumeric_mpiaij) {
 35:     SETERRQ2(PETSC_ERR_SUP,"Not implemented for A=%s and P=%s",A->type_name,P->type_name);
 36:   }
 37:   (*P->ops->ptapnumeric_mpiaij)(A,P,C);
 38:   return(0);
 39: }

 43: PetscErrorCode MatPtAPSymbolic_MPIAIJ_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat *C)
 44: {
 45:   PetscErrorCode       ierr;
 46:   Mat                  B_mpi;
 47:   Mat_MatMatMultMPI    *ap;
 48:   PetscObjectContainer container;
 49:   FreeSpaceList        free_space=PETSC_NULL,current_space=PETSC_NULL;
 50:   Mat_MPIAIJ           *a=(Mat_MPIAIJ*)A->data,*p=(Mat_MPIAIJ*)P->data;
 51:   Mat_SeqAIJ           *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data;
 52:   Mat_SeqAIJ           *p_loc,*p_oth;
 53:   PetscInt             *pi_loc,*pj_loc,*pi_oth,*pj_oth,*pdti,*pdtj,*poti,*potj,*ptJ;
 54:   PetscInt             *adi=ad->i,*adj=ad->j,*aoi=ao->i,*aoj=ao->j,nnz;
 55:   PetscInt             nlnk,*lnk,*owners_co,*coi,*coj,i,k,pnz,row;
 56:   PetscInt             am=A->m,pN=P->N,pn=P->n;
 57:   PetscBT              lnkbt;
 58:   MPI_Comm             comm=A->comm;
 59:   PetscMPIInt          size,rank,tag,*len_si,*len_s,*len_ri;
 60:   PetscInt             **buf_rj,**buf_ri,**buf_ri_k;
 61:   PetscInt             len,proc,*dnz,*onz,*owners;
 62:   PetscInt             nzi,*bi,*bj;
 63:   PetscInt             nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextci;
 64:   MPI_Request          *swaits,*rwaits;
 65:   MPI_Status           *sstatus,rstatus;
 66:   Mat_Merge_SeqsToMPI  *merge;
 67:   PetscInt             *api,*apj,*Jptr,apnz,*prmap=p->garray,pon;
 68:   PetscMPIInt          j;

 71:   MPI_Comm_size(comm,&size);
 72:   MPI_Comm_rank(comm,&rank);

 74:   /* destroy the container 'Mat_MatMatMultMPI' in case that P is attached to it */
 75:   PetscObjectQuery((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject *)&container);
 76:   if (container) {
 77:     PetscObjectContainerDestroy(container);
 78:     PetscObjectCompose((PetscObject)P,"Mat_MatMatMultMPI",0);
 79:   }

 81:   /* create the container 'Mat_MatMatMultMPI' and attach it to P */
 82:   PetscNew(Mat_MatMatMultMPI,&ap);
 83:   ap->abi=PETSC_NULL; ap->abj=PETSC_NULL;
 84:   ap->abnz_max = 0;

 86:   PetscObjectContainerCreate(PETSC_COMM_SELF,&container);
 87:   PetscObjectContainerSetPointer(container,ap);
 88:   PetscObjectCompose((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject)container);
 89:   ap->MatDestroy  = P->ops->destroy;
 90:   P->ops->destroy = MatDestroy_MPIAIJ_MatMatMult;
 91:   ap->reuse       = MAT_INITIAL_MATRIX;
 92:   PetscObjectContainerSetUserDestroy(container,PetscObjectContainerDestroy_Mat_MatMatMultMPI);

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

 99:   p_loc = (Mat_SeqAIJ*)(ap->B_loc)->data;
100:   p_oth = (Mat_SeqAIJ*)(ap->B_oth)->data;
101:   pi_loc = p_loc->i; pj_loc = p_loc->j;
102:   pi_oth = p_oth->i; pj_oth = p_oth->j;

104:   /* first, compute symbolic AP = A_loc*P */
105:   /*--------------------------------------*/
106:   PetscMalloc((am+2)*sizeof(PetscInt),&api);
107:   ap->abi = api;
108:   api[0] = 0;

110:   /* create and initialize a linked list */
111:   nlnk = pN+1;
112:   PetscLLCreate(pN,pN,nlnk,lnk,lnkbt);

114:   /* Initial FreeSpace size is fill*nnz(A) */
115:   GetMoreSpace((PetscInt)(fill*(adi[am]+aoi[am])),&free_space);
116:   current_space = free_space;

118:   for (i=0;i<am;i++) {
119:     apnz = 0;
120:     /* diagonal portion of A */
121:     nzi = adi[i+1] - adi[i];
122:     for (j=0; j<nzi; j++){
123:       row = *adj++;
124:       pnz = pi_loc[row+1] - pi_loc[row];
125:       Jptr  = pj_loc + pi_loc[row];
126:       /* add non-zero cols of P into the sorted linked list lnk */
127:       PetscLLAdd(pnz,Jptr,pN,nlnk,lnk,lnkbt);
128:       apnz += nlnk;
129:     }
130:     /* off-diagonal portion of A */
131:     nzi = aoi[i+1] - aoi[i];
132:     for (j=0; j<nzi; j++){
133:       row = *aoj++;
134:       pnz = pi_oth[row+1] - pi_oth[row];
135:       Jptr  = pj_oth + pi_oth[row];
136:       PetscLLAdd(pnz,Jptr,pN,nlnk,lnk,lnkbt);
137:       apnz += nlnk;
138:     }

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

143:     /* if free space is not available, double the total space in the list */
144:     if (current_space->local_remaining<apnz) {
145:       GetMoreSpace(current_space->total_array_size,&current_space);
146:     }

148:     /* Copy data into free space, then initialize lnk */
149:     PetscLLClean(pN,pN,apnz,lnk,current_space->array,lnkbt);
150:     current_space->array           += apnz;
151:     current_space->local_used      += apnz;
152:     current_space->local_remaining -= apnz;
153:   }
154:   /* Allocate space for apj, initialize apj, and */
155:   /* destroy list of free space and other temporary array(s) */
156:   PetscMalloc((api[am]+1)*sizeof(PetscInt),&ap->abj);
157:   apj = ap->abj;
158:   MakeSpaceContiguous(&free_space,ap->abj);

160:   /* determine symbolic Co=(p->B)^T*AP - send to others */
161:   /*----------------------------------------------------*/
162:   MatGetSymbolicTranspose_SeqAIJ(p->B,&poti,&potj);

164:   /* then, compute symbolic Co = (p->B)^T*AP */
165:   pon = (p->B)->n; /* total num of rows to be sent to other processors 
166:                          >= (num of nonzero rows of C_seq) - pn */
167:   PetscMalloc((pon+1)*sizeof(PetscInt),&coi);
168:   coi[0] = 0;

170:   /* set initial free space to be 3*pon*max( nnz(AP) per row) */
171:   nnz           = 3*pon*ap->abnz_max + 1;
172:   GetMoreSpace(nnz,&free_space);
173:   current_space = free_space;

175:   for (i=0; i<pon; i++) {
176:     nnz  = 0;
177:     pnz = poti[i+1] - poti[i];
178:     j     = pnz;
179:     ptJ   = potj + poti[i+1];
180:     while (j){/* assume cols are almost in increasing order, starting from its end saves computation */
181:       j--; ptJ--;
182:       row  = *ptJ; /* row of AP == col of Pot */
183:       apnz = api[row+1] - api[row];
184:       Jptr   = apj + api[row];
185:       /* add non-zero cols of AP into the sorted linked list lnk */
186:       PetscLLAdd(apnz,Jptr,pN,nlnk,lnk,lnkbt);
187:       nnz += nlnk;
188:     }

190:     /* If free space is not available, double the total space in the list */
191:     if (current_space->local_remaining<nnz) {
192:       GetMoreSpace(current_space->total_array_size,&current_space);
193:     }

195:     /* Copy data into free space, and zero out denserows */
196:     PetscLLClean(pN,pN,nnz,lnk,current_space->array,lnkbt);
197:     current_space->array           += nnz;
198:     current_space->local_used      += nnz;
199:     current_space->local_remaining -= nnz;
200:     coi[i+1] = coi[i] + nnz;
201:   }
202:   PetscMalloc((coi[pon]+1)*sizeof(PetscInt),&coj);
203:   MakeSpaceContiguous(&free_space,coj);
204:   MatRestoreSymbolicTranspose_SeqAIJ(p->B,&poti,&potj);

206:   /* send j-array (coj) of Co to other processors */
207:   /*----------------------------------------------*/
208:   /* determine row ownership */
209:   PetscNew(Mat_Merge_SeqsToMPI,&merge);
210:   PetscMapCreate(comm,&merge->rowmap);
211:   PetscMapSetLocalSize(merge->rowmap,pn);
212:   PetscMapSetType(merge->rowmap,MAP_MPI);
213:   PetscMapGetGlobalRange(merge->rowmap,&owners);

215:   /* determine the number of messages to send, their lengths */
216:   PetscMalloc(size*sizeof(PetscMPIInt),&len_si);
217:   PetscMemzero(len_si,size*sizeof(PetscMPIInt));
218:   PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);
219:   len_s = merge->len_s;
220:   merge->nsend = 0;
221: 
222:   PetscMalloc((size+2)*sizeof(PetscInt),&owners_co);
223:   PetscMemzero(len_s,size*sizeof(PetscMPIInt));

225:   proc = 0;
226:   for (i=0; i<pon; i++){
227:     while (prmap[i] >= owners[proc+1]) proc++;
228:     len_si[proc]++;  /* num of rows in Co to be sent to [proc] */
229:     len_s[proc] += coi[i+1] - coi[i];
230:   }

232:   len   = 0;  /* max length of buf_si[] */
233:   owners_co[0] = 0;
234:   for (proc=0; proc<size; proc++){
235:     owners_co[proc+1] = owners_co[proc] + len_si[proc];
236:     if (len_si[proc]){
237:       merge->nsend++;
238:       len_si[proc] = 2*(len_si[proc] + 1);
239:       len += len_si[proc];
240:     }
241:   }

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

247:   /* post the Irecv and Isend of coj */
248:   PetscObjectGetNewTag((PetscObject)merge->rowmap,&tag);
249:   PetscPostIrecvInt(comm,tag,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rwaits);

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

253:   for (proc=0, k=0; proc<size; proc++){
254:     if (!len_s[proc]) continue;
255:     i = owners_co[proc];
256:     MPI_Isend(coj+coi[i],len_s[proc],MPIU_INT,proc,tag,comm,swaits+k);
257:     k++;
258:   }

260:   /* receives and sends of coj are complete */
261:   PetscMalloc(size*sizeof(MPI_Status),&sstatus);
262:   i = merge->nrecv;
263:   while (i--) {
264:     MPI_Waitany(merge->nrecv,rwaits,&j,&rstatus);
265:   }
266:   PetscFree(rwaits);
267:   if (merge->nsend) {MPI_Waitall(merge->nsend,swaits,sstatus);}
268: 
269:   /* send and recv coi */
270:   /*-------------------*/
271:   PetscPostIrecvInt(comm,tag,merge->nrecv,merge->id_r,len_ri,&buf_ri,&rwaits);
272: 
273:   PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);
274:   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
275:   for (proc=0,k=0; proc<size; proc++){
276:     if (!len_s[proc]) continue;
277:     /* form outgoing message for i-structure: 
278:          buf_si[0]:                 nrows to be sent
279:                [1:nrows]:           row index (global)
280:                [nrows+1:2*nrows+1]: i-structure index
281:     */
282:     /*-------------------------------------------*/
283:     nrows = len_si[proc]/2 - 1;
284:     buf_si_i    = buf_si + nrows+1;
285:     buf_si[0]   = nrows;
286:     buf_si_i[0] = 0;
287:     nrows = 0;
288:     for (i=owners_co[proc]; i<owners_co[proc+1]; i++){
289:       nzi = coi[i+1] - coi[i];
290:       buf_si_i[nrows+1] = buf_si_i[nrows] + nzi; /* i-structure */
291:       buf_si[nrows+1] =prmap[i] -owners[proc]; /* local row index */
292:       nrows++;
293:     }
294:     MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tag,comm,swaits+k);
295:     k++;
296:     buf_si += len_si[proc];
297:   }
298:   i = merge->nrecv;
299:   while (i--) {
300:     MPI_Waitany(merge->nrecv,rwaits,&j,&rstatus);
301:   }
302:   PetscFree(rwaits);
303:   if (merge->nsend) {MPI_Waitall(merge->nsend,swaits,sstatus);}

305:   PetscLogInfo(((PetscObject)A,"MatMerge_SeqsToMPI: nsend: %d, nrecv: %d\n",merge->nsend,merge->nrecv));
306:   for (i=0; i<merge->nrecv; i++){
307:     PetscLogInfo(((PetscObject)A,"MatMerge_SeqsToMPI:   recv len_ri=%d, len_rj=%d from [%d]\n",len_ri[i],merge->len_r[i],merge->id_r[i]));
308:   }

310:   PetscFree(len_si);
311:   PetscFree(len_ri);
312:   PetscFree(swaits);
313:   PetscFree(sstatus);
314:   PetscFree(buf_s);

316:   /* compute the local portion of C (mpi mat) */
317:   /*------------------------------------------*/
318:   MatGetSymbolicTranspose_SeqAIJ(p->A,&pdti,&pdtj);

320:   /* allocate bi array and free space for accumulating nonzero column info */
321:   PetscMalloc((pn+1)*sizeof(PetscInt),&bi);
322:   bi[0] = 0;
323: 
324:   /* set initial free space to be 3*pn*max( nnz(AP) per row) */
325:   nnz           = 3*pn*ap->abnz_max + 1;
326:   GetMoreSpace(nnz,&free_space);
327:   current_space = free_space;

329:   PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);
330:   nextrow = buf_ri_k + merge->nrecv;
331:   nextci  = nextrow + merge->nrecv;
332:   for (k=0; k<merge->nrecv; k++){
333:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
334:     nrows       = *buf_ri_k[k];
335:     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
336:     nextci[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
337:   }
338:   MatPreallocateInitialize(comm,pn,pn,dnz,onz);
339:   for (i=0; i<pn; i++) {
340:     /* add pdt[i,:]*AP into lnk */
341:     nnz = 0;
342:     pnz  = pdti[i+1] - pdti[i];
343:     j    = pnz;
344:     ptJ  = pdtj + pdti[i+1];
345:     while (j){/* assume cols are almost in increasing order, starting from its end saves computation */
346:       j--; ptJ--;
347:       row  = *ptJ; /* row of AP == col of Pt */
348:       apnz = api[row+1] - api[row];
349:       Jptr   = apj + api[row];
350:       /* add non-zero cols of AP into the sorted linked list lnk */
351:       PetscLLAdd(apnz,Jptr,pN,nlnk,lnk,lnkbt);
352:       nnz += nlnk;
353:     }
354:     /* add received col data into lnk */
355:     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
356:       if (i == *nextrow[k]) { /* i-th row */
357:         nzi = *(nextci[k]+1) - *nextci[k];
358:         Jptr  = buf_rj[k] + *nextci[k];
359:         PetscLLAdd(nzi,Jptr,pN,nlnk,lnk,lnkbt);
360:         nnz += nlnk;
361:         nextrow[k]++; nextci[k]++;
362:       }
363:     }

365:     /* if free space is not available, make more free space */
366:     if (current_space->local_remaining<nnz) {
367:       GetMoreSpace(current_space->total_array_size,&current_space);
368:     }
369:     /* copy data into free space, then initialize lnk */
370:     PetscLLClean(pN,pN,nnz,lnk,current_space->array,lnkbt);
371:     MatPreallocateSet(i+owners[rank],nnz,current_space->array,dnz,onz);
372:     current_space->array           += nnz;
373:     current_space->local_used      += nnz;
374:     current_space->local_remaining -= nnz;
375:     bi[i+1] = bi[i] + nnz;
376:   }
377:   MatRestoreSymbolicTranspose_SeqAIJ(p->A,&pdti,&pdtj);
378:   PetscFree(buf_ri_k);

380:   PetscMalloc((bi[pn]+1)*sizeof(PetscInt),&bj);
381:   MakeSpaceContiguous(&free_space,bj);
382:   PetscLLDestroy(lnk,lnkbt);

384:   /* create symbolic parallel matrix B_mpi */
385:   /*---------------------------------------*/
386:   MatCreate(comm,&B_mpi);
387:   MatSetSizes(B_mpi,pn,pn,PETSC_DETERMINE,PETSC_DETERMINE);
388:   MatSetType(B_mpi,MATMPIAIJ);
389:   MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);
390:   MatPreallocateFinalize(dnz,onz);

392:   /* B_mpi is not ready for use - assembly will be done by MatPtAPNumeric() */
393:   B_mpi->assembled     = PETSC_FALSE;
394:   B_mpi->ops->destroy  = MatDestroy_MPIAIJ_SeqsToMPI;
395:   merge->bi            = bi;
396:   merge->bj            = bj;
397:   merge->coi           = coi;
398:   merge->coj           = coj;
399:   merge->buf_ri        = buf_ri;
400:   merge->buf_rj        = buf_rj;
401:   merge->owners_co     = owners_co;

403:   /* attach the supporting struct to B_mpi for reuse */
404:   PetscObjectContainerCreate(PETSC_COMM_SELF,&container);
405:   PetscObjectContainerSetPointer(container,merge);
406:   PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);
407:   *C = B_mpi;
408:   return(0);
409: }

413: PetscErrorCode MatPtAPNumeric_MPIAIJ_MPIAIJ(Mat A,Mat P,Mat C)
414: {
415:   PetscErrorCode       ierr;
416:   Mat_Merge_SeqsToMPI  *merge;
417:   Mat_MatMatMultMPI    *ap;
418:   PetscObjectContainer cont_merge,cont_ptap;
419:   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data,*p=(Mat_MPIAIJ*)P->data;
420:   Mat_SeqAIJ     *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data;
421:   Mat_SeqAIJ     *pd=(Mat_SeqAIJ*)(p->A)->data,*po=(Mat_SeqAIJ*)(p->B)->data;
422:   Mat_SeqAIJ     *p_loc,*p_oth;
423:   PetscInt       *adi=ad->i,*aoi=ao->i,*adj=ad->j,*aoj=ao->j,*apJ,nextp,flops=0;
424:   PetscInt       *pi_loc,*pj_loc,*pi_oth,*pj_oth,*pJ,*pj;
425:   PetscInt       i,j,k,anz,pnz,apnz,nextap,row,*cj;
426:   MatScalar      *ada=ad->a,*aoa=ao->a,*apa,*pa,*ca,*pa_loc,*pa_oth;
427:   PetscInt       am=A->m,cm=C->m,pon=(p->B)->n;
428:   MPI_Comm       comm=C->comm;
429:   PetscMPIInt    size,rank,taga,*len_s;
430:   PetscInt       *owners,proc,nrows,**buf_ri_k,**nextrow,**nextci;
431:   PetscInt       **buf_ri,**buf_rj;
432:   PetscInt       cnz=0,*bj_i,*bi,*bj,bnz,nextcj; /* bi,bj,ba: local array of C(mpi mat) */
433:   MPI_Request    *s_waits,*r_waits;
434:   MPI_Status     *status;
435:   MatScalar      **abuf_r,*ba_i,*pA,*coa,*ba;
436:   PetscInt       *api,*apj,*coi,*coj;
437:   PetscInt       *poJ=po->j,*pdJ=pd->j,pcstart=p->cstart,pcend=p->cend;

440:   MPI_Comm_size(comm,&size);
441:   MPI_Comm_rank(comm,&rank);

443:   PetscObjectQuery((PetscObject)C,"MatMergeSeqsToMPI",(PetscObject *)&cont_merge);
444:   if (cont_merge) {
445:     PetscObjectContainerGetPointer(cont_merge,(void **)&merge);
446:   } else {
447:     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix C does not posses an object container");
448:   }

450:   PetscObjectQuery((PetscObject)P,"Mat_MatMatMultMPI",(PetscObject *)&cont_ptap);
451:   if (cont_ptap) {
452:     PetscObjectContainerGetPointer(cont_ptap,(void **)&ap);
453:     if (ap->reuse == MAT_INITIAL_MATRIX){
454:       ap->reuse = MAT_REUSE_MATRIX;
455:     } else { /* update numerical values of P_oth and P_loc */
456:       MatGetBrowsOfAoCols(A,P,MAT_REUSE_MATRIX,&ap->startsj,&ap->bufa,&ap->B_oth);
457:       MatGetLocalMat(P,MAT_REUSE_MATRIX,&ap->B_loc);
458:     }
459:   } else {
460:     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
461:   }

463:   /* get data from symbolic products */
464:   p_loc = (Mat_SeqAIJ*)(ap->B_loc)->data;
465:   p_oth = (Mat_SeqAIJ*)(ap->B_oth)->data;
466:   pi_loc=p_loc->i; pj_loc=p_loc->j; pJ=pj_loc; pa_loc=p_loc->a,pA=pa_loc;
467:   pi_oth=p_oth->i; pj_oth=p_oth->j; pa_oth=p_oth->a;
468: 
469:   coi = merge->coi; coj = merge->coj;
470:   PetscMalloc((coi[pon]+1)*sizeof(MatScalar),&coa);
471:   PetscMemzero(coa,coi[pon]*sizeof(MatScalar));

473:   bi = merge->bi; bj = merge->bj;
474:   PetscMapGetGlobalRange(merge->rowmap,&owners);
475:   PetscMalloc((bi[cm]+1)*sizeof(MatScalar),&ba);
476:   PetscMemzero(ba,bi[cm]*sizeof(MatScalar));

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

482:   /* compute numeric C_seq=P_loc^T*A_loc*P */
483:   api = ap->abi; apj = ap->abj;
484:   for (i=0;i<am;i++) {
485:     /* form i-th sparse row of A*P */
486:     apnz = api[i+1] - api[i];
487:     apJ  = apj + api[i];
488:     /* diagonal portion of A */
489:     anz  = adi[i+1] - adi[i];
490:     for (j=0;j<anz;j++) {
491:       row = *adj++;
492:       pnz = pi_loc[row+1] - pi_loc[row];
493:       pj  = pj_loc + pi_loc[row];
494:       pa  = pa_loc + pi_loc[row];
495:       nextp = 0;
496:       for (k=0; nextp<pnz; k++) {
497:         if (apJ[k] == pj[nextp]) { /* col of AP == col of P */
498:           apa[k] += (*ada)*pa[nextp++];
499:         }
500:       }
501:       flops += 2*pnz;
502:       ada++;
503:     }
504:     /* off-diagonal portion of A */
505:     anz  = aoi[i+1] - aoi[i];
506:     for (j=0; j<anz; j++) {
507:       row = *aoj++;
508:       pnz = pi_oth[row+1] - pi_oth[row];
509:       pj  = pj_oth + pi_oth[row];
510:       pa  = pa_oth + pi_oth[row];
511:       nextp = 0;
512:       for (k=0; nextp<pnz; k++) {
513:         if (apJ[k] == pj[nextp]) { /* col of AP == col of P */
514:           apa[k] += (*aoa)*pa[nextp++];
515:         }
516:       }
517:       flops += 2*pnz;
518:       aoa++;
519:     }

521:     /* Compute P_loc[i,:]^T*AP[i,:] using outer product */
522:     pnz = pi_loc[i+1] - pi_loc[i];
523:     for (j=0; j<pnz; j++) {
524:       nextap = 0;
525:       row    = *pJ++; /* global index */
526:       if (row < pcstart || row >=pcend) { /* put the value into Co */
527:         cj  = coj + coi[*poJ];
528:         ca  = coa + coi[*poJ++];
529:       } else {                            /* put the value into Cd */
530:         cj   = bj + bi[*pdJ];
531:         ca   = ba + bi[*pdJ++];
532:       }
533:       for (k=0; nextap<apnz; k++) {
534:         if (cj[k]==apJ[nextap]) ca[k] += (*pA)*apa[nextap++];
535:       }
536:       flops += 2*apnz;
537:       pA++;
538:     }

540:     /* zero the current row info for A*P */
541:     PetscMemzero(apa,apnz*sizeof(MatScalar));
542:   }
543:   PetscFree(apa);
544: 
545:   /* send and recv matrix values */
546:   /*-----------------------------*/
547:   buf_ri = merge->buf_ri;
548:   buf_rj = merge->buf_rj;
549:   len_s  = merge->len_s;
550:   PetscObjectGetNewTag((PetscObject)merge->rowmap,&taga);
551:   PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);

553:   PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);
554:   for (proc=0,k=0; proc<size; proc++){
555:     if (!len_s[proc]) continue;
556:     i = merge->owners_co[proc];
557:     MPI_Isend(coa+coi[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);
558:     k++;
559:   }
560:   PetscMalloc(size*sizeof(MPI_Status),&status);
561:   if (merge->nrecv) {MPI_Waitall(merge->nrecv,r_waits,status);}
562:   if (merge->nsend) {MPI_Waitall(merge->nsend,s_waits,status);}
563:   PetscFree(status);

565:   PetscFree(s_waits);
566:   PetscFree(r_waits);
567:   PetscFree(coa);

569:   /* insert local and received values into C */
570:   /*-----------------------------------------*/
571:   PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);
572:   nextrow   = buf_ri_k + merge->nrecv;
573:   nextci = nextrow + merge->nrecv;

575:   for (k=0; k<merge->nrecv; k++){
576:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
577:     nrows       = *(buf_ri_k[k]);
578:     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
579:     nextci[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
580:   }

582:   for (i=0; i<cm; i++) {
583:     row = owners[rank] + i; /* global row index of C_seq */
584:     bj_i = bj + bi[i];  /* col indices of the i-th row of C */
585:     ba_i = ba + bi[i];
586:     bnz  = bi[i+1] - bi[i];
587:     /* add received vals into ba */
588:     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
589:       /* i-th row */
590:       if (i == *nextrow[k]) {
591:         cnz = *(nextci[k]+1) - *nextci[k];
592:         cj  = buf_rj[k] + *(nextci[k]);
593:         ca  = abuf_r[k] + *(nextci[k]);
594:         nextcj = 0;
595:         for (j=0; nextcj<cnz; j++){
596:           if (bj_i[j] == cj[nextcj]){ /* bcol == ccol */
597:             ba_i[j] += ca[nextcj++];
598:           }
599:         }
600:         nextrow[k]++; nextci[k]++;
601:       }
602:     }
603:     MatSetValues(C,1,&row,bnz,bj_i,ba_i,INSERT_VALUES);
604:     flops += 2*cnz;
605:   }
606:   MatSetOption(C,MAT_COLUMNS_SORTED); /* -cause delay? */
607:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
608:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);

610:   PetscFree(ba);
611:   PetscFree(abuf_r);
612:   PetscFree(buf_ri_k);
613:   PetscLogFlops(flops);
614:   return(0);
615: }