Actual source code: mpimatmatmult.c

  1: /*
  2:   Defines matrix-matrix product routines for pairs of MPIAIJ matrices
  3:           C = A * B
  4: */
  5: #include <../src/mat/impls/aij/seq/aij.h>
  6: #include <../src/mat/utils/freespace.h>
  7: #include <../src/mat/impls/aij/mpi/mpiaij.h>
  8: #include <../src/mat/impls/dense/mpi/mpidense.h>
  9: #include <petsc/private/vecimpl.h>
 10: #include <petsc/private/sfimpl.h>

 12: #if PetscDefined(HAVE_HYPRE)
 13: PETSC_INTERN PetscErrorCode MatMatMultSymbolic_AIJ_AIJ_wHYPRE(Mat, Mat, PetscReal, Mat);
 14: #endif

 16: PETSC_INTERN PetscErrorCode MatProductSymbolic_ABt_MPIAIJ_MPIAIJ(Mat C)
 17: {
 18:   Mat_Product *product = C->product;
 19:   Mat          B       = product->B;

 21:   PetscFunctionBegin;
 22:   PetscCall(MatTranspose(B, MAT_INITIAL_MATRIX, &product->B));
 23:   PetscCall(MatDestroy(&B));
 24:   PetscCall(MatProductSymbolic_AB_MPIAIJ_MPIAIJ(C));
 25:   PetscFunctionReturn(PETSC_SUCCESS);
 26: }

 28: PETSC_INTERN PetscErrorCode MatProductSymbolic_AB_MPIAIJ_MPIAIJ(Mat C)
 29: {
 30:   Mat_Product        *product = C->product;
 31:   Mat                 A = product->A, B = product->B;
 32:   MatProductAlgorithm alg  = product->alg;
 33:   PetscReal           fill = product->fill;
 34:   PetscBool           flg;

 36:   PetscFunctionBegin;
 37:   /* scalable */
 38:   PetscCall(PetscStrcmp(alg, "scalable", &flg));
 39:   if (flg || C->structure_only) {
 40:     if (C->structure_only) PetscCall(MatProductSetAlgorithm(C, "scalable"));
 41:     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ(A, B, fill, C));
 42:     PetscFunctionReturn(PETSC_SUCCESS);
 43:   }

 45:   /* nonscalable */
 46:   PetscCall(PetscStrcmp(alg, "nonscalable", &flg));
 47:   if (flg) {
 48:     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(A, B, fill, C));
 49:     PetscFunctionReturn(PETSC_SUCCESS);
 50:   }

 52:   /* seqmpi */
 53:   PetscCall(PetscStrcmp(alg, "seqmpi", &flg));
 54:   if (flg) {
 55:     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ_seqMPI(A, B, fill, C));
 56:     PetscFunctionReturn(PETSC_SUCCESS);
 57:   }

 59:   /* backend general code */
 60:   PetscCall(PetscStrcmp(alg, "backend", &flg));
 61:   if (flg) {
 62:     PetscCall(MatProductSymbolic_MPIAIJBACKEND(C));
 63:     PetscFunctionReturn(PETSC_SUCCESS);
 64:   }

 66: #if PetscDefined(HAVE_HYPRE)
 67:   PetscCall(PetscStrcmp(alg, "hypre", &flg));
 68:   if (flg) {
 69:     PetscCall(MatMatMultSymbolic_AIJ_AIJ_wHYPRE(A, B, fill, C));
 70:     PetscFunctionReturn(PETSC_SUCCESS);
 71:   }
 72: #endif
 73:   SETERRQ(PetscObjectComm((PetscObject)C), PETSC_ERR_SUP, "Mat Product Algorithm is not supported");
 74: }

 76: PetscErrorCode MatProductCtxDestroy_MPIAIJ_MatMatMult(PetscCtxRt data)
 77: {
 78:   MatProductCtx_APMPI *ptap = *(MatProductCtx_APMPI **)data;

 80:   PetscFunctionBegin;
 81:   PetscCall(PetscFree2(ptap->startsj_s, ptap->startsj_r));
 82:   PetscCall(PetscFree(ptap->bufa));
 83:   PetscCall(MatDestroy(&ptap->P_loc));
 84:   PetscCall(MatDestroy(&ptap->P_oth));
 85:   PetscCall(MatDestroy(&ptap->Pt));
 86:   PetscCall(PetscFree(ptap->api));
 87:   PetscCall(PetscFree(ptap->apj));
 88:   PetscCall(PetscFree(ptap->apa));
 89:   PetscCall(PetscFree(ptap));
 90:   PetscFunctionReturn(PETSC_SUCCESS);
 91: }

 93: PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat A, Mat P, Mat C)
 94: {
 95:   Mat_MPIAIJ          *a = (Mat_MPIAIJ *)A->data, *c = (Mat_MPIAIJ *)C->data;
 96:   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data;
 97:   Mat_SeqAIJ          *cd = (Mat_SeqAIJ *)c->A->data, *co = (Mat_SeqAIJ *)c->B->data;
 98:   PetscScalar         *cda, *coa;
 99:   Mat_SeqAIJ          *p_loc, *p_oth;
100:   PetscScalar         *apa, *ca;
101:   PetscInt             cm = C->rmap->n;
102:   MatProductCtx_APMPI *ptap;
103:   PetscInt            *api, *apj, *apJ, i, k;
104:   PetscInt             cstart = C->cmap->rstart;
105:   PetscInt             cdnz, conz, k0, k1;
106:   const PetscScalar   *dummy1, *dummy2, *dummy3, *dummy4;
107:   MPI_Comm             comm;
108:   PetscMPIInt          size;

110:   PetscFunctionBegin;
111:   MatCheckProduct(C, 3);
112:   ptap = (MatProductCtx_APMPI *)C->product->data;
113:   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
114:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
115:   PetscCallMPI(MPI_Comm_size(comm, &size));
116:   PetscCheck(ptap->P_oth || size <= 1, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "AP cannot be reused. Do not call MatProductClear()");

118:   /* flag CPU mask for C */
119: #if PetscDefined(HAVE_DEVICE)
120:   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
121:   if (c->A->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->A->offloadmask = PETSC_OFFLOAD_CPU;
122:   if (c->B->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->B->offloadmask = PETSC_OFFLOAD_CPU;
123: #endif

125:   /* 1) get P_oth = ptap->P_oth  and P_loc = ptap->P_loc */
126:   /* update numerical values of P_oth and P_loc */
127:   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_REUSE_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
128:   PetscCall(MatMPIAIJGetLocalMat(P, MAT_REUSE_MATRIX, &ptap->P_loc));

130:   /* 2) compute numeric C_loc = A_loc*P = Ad*P_loc + Ao*P_oth */
131:   /* get data from symbolic products */
132:   p_loc = (Mat_SeqAIJ *)ptap->P_loc->data;
133:   p_oth = NULL;
134:   if (size > 1) p_oth = (Mat_SeqAIJ *)ptap->P_oth->data;

136:   /* get apa for storing dense row A[i,:]*P */
137:   apa = ptap->apa;

139:   api = ptap->api;
140:   apj = ptap->apj;
141:   /* trigger copy to CPU */
142:   PetscCall(MatSeqAIJGetArrayRead(a->A, &dummy1));
143:   PetscCall(MatSeqAIJGetArrayRead(a->B, &dummy2));
144:   PetscCall(MatSeqAIJGetArrayRead(ptap->P_loc, &dummy3));
145:   if (ptap->P_oth) PetscCall(MatSeqAIJGetArrayRead(ptap->P_oth, &dummy4));
146:   PetscCall(MatSeqAIJGetArrayWrite(c->A, &cda));
147:   PetscCall(MatSeqAIJGetArrayWrite(c->B, &coa));
148:   for (i = 0; i < cm; i++) {
149:     /* compute apa = A[i,:]*P */
150:     AProw_nonscalable(i, ad, ao, p_loc, p_oth, apa);

152:     /* set values in C */
153:     apJ  = PetscSafePointerPlusOffset(apj, api[i]);
154:     cdnz = cd->i[i + 1] - cd->i[i];
155:     conz = co->i[i + 1] - co->i[i];

157:     /* 1st off-diagonal part of C */
158:     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
159:     k  = 0;
160:     for (k0 = 0; k0 < conz; k0++) {
161:       if (apJ[k] >= cstart) break;
162:       ca[k0]        = apa[apJ[k]];
163:       apa[apJ[k++]] = 0.0;
164:     }

166:     /* diagonal part of C */
167:     ca = PetscSafePointerPlusOffset(cda, cd->i[i]);
168:     for (k1 = 0; k1 < cdnz; k1++) {
169:       ca[k1]        = apa[apJ[k]];
170:       apa[apJ[k++]] = 0.0;
171:     }

173:     /* 2nd off-diagonal part of C */
174:     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
175:     for (; k0 < conz; k0++) {
176:       ca[k0]        = apa[apJ[k]];
177:       apa[apJ[k++]] = 0.0;
178:     }
179:   }
180:   PetscCall(MatSeqAIJRestoreArrayRead(a->A, &dummy1));
181:   PetscCall(MatSeqAIJRestoreArrayRead(a->B, &dummy2));
182:   PetscCall(MatSeqAIJRestoreArrayRead(ptap->P_loc, &dummy3));
183:   if (ptap->P_oth) PetscCall(MatSeqAIJRestoreArrayRead(ptap->P_oth, &dummy4));
184:   PetscCall(MatSeqAIJRestoreArrayWrite(c->A, &cda));
185:   PetscCall(MatSeqAIJRestoreArrayWrite(c->B, &coa));

187:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
188:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
189:   PetscFunctionReturn(PETSC_SUCCESS);
190: }

192: PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat A, Mat P, PetscReal fill, Mat C)
193: {
194:   MPI_Comm             comm;
195:   PetscMPIInt          size;
196:   MatProductCtx_APMPI *ptap;
197:   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
198:   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
199:   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc, *p_oth;
200:   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *dnz, *onz;
201:   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, *aoj = ao->j, rstart = A->rmap->rstart;
202:   PetscInt            *lnk, i, pnz, row, *api, *apj, *Jptr, apnz, nspacedouble = 0, j, nzi;
203:   PetscInt             am = A->rmap->n, pN = P->cmap->N, pn = P->cmap->n, pm = P->rmap->n;
204:   PetscBT              lnkbt;
205:   PetscReal            afill;
206:   MatType              mtype;

208:   PetscFunctionBegin;
209:   MatCheckProduct(C, 4);
210:   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
211:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
212:   PetscCallMPI(MPI_Comm_size(comm, &size));

214:   /* create struct MatProductCtx_APMPI and attached it to C later */
215:   PetscCall(PetscNew(&ptap));

217:   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
218:   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));

220:   /* get P_loc by taking all local rows of P */
221:   PetscCall(MatMPIAIJGetLocalMat(P, MAT_INITIAL_MATRIX, &ptap->P_loc));

223:   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
224:   pi_loc = p_loc->i;
225:   pj_loc = p_loc->j;
226:   if (size > 1) {
227:     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
228:     pi_oth = p_oth->i;
229:     pj_oth = p_oth->j;
230:   } else {
231:     p_oth  = NULL;
232:     pi_oth = NULL;
233:     pj_oth = NULL;
234:   }

236:   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
237:   PetscCall(PetscMalloc1(am + 1, &api));
238:   ptap->api = api;
239:   api[0]    = 0;

241:   /* create and initialize a linked list */
242:   PetscCall(PetscLLCondensedCreate(pN, pN, &lnk, &lnkbt));

244:   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
245:   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space));
246:   current_space = free_space;

248:   MatPreallocateBegin(comm, am, pn, dnz, onz);
249:   for (i = 0; i < am; i++) {
250:     /* diagonal portion of A */
251:     nzi = adi[i + 1] - adi[i];
252:     for (j = 0; j < nzi; j++) {
253:       row  = *adj++;
254:       pnz  = pi_loc[row + 1] - pi_loc[row];
255:       Jptr = pj_loc + pi_loc[row];
256:       /* add non-zero cols of P into the sorted linked list lnk */
257:       PetscCall(PetscLLCondensedAddSorted(pnz, Jptr, lnk, lnkbt));
258:     }
259:     /* off-diagonal portion of A */
260:     nzi = aoi[i + 1] - aoi[i];
261:     for (j = 0; j < nzi; j++) {
262:       row  = *aoj++;
263:       pnz  = pi_oth[row + 1] - pi_oth[row];
264:       Jptr = pj_oth + pi_oth[row];
265:       PetscCall(PetscLLCondensedAddSorted(pnz, Jptr, lnk, lnkbt));
266:     }
267:     /* add possible missing diagonal entry */
268:     if (C->force_diagonals) {
269:       j = i + rstart; /* column index */
270:       PetscCall(PetscLLCondensedAddSorted(1, &j, lnk, lnkbt));
271:     }

273:     apnz       = lnk[0];
274:     api[i + 1] = api[i] + apnz;

276:     /* if free space is not available, double the total space in the list */
277:     if (current_space->local_remaining < apnz) {
278:       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(apnz, current_space->total_array_size), &current_space));
279:       nspacedouble++;
280:     }

282:     /* Copy data into free space, then initialize lnk */
283:     PetscCall(PetscLLCondensedClean(pN, apnz, current_space->array, lnk, lnkbt));
284:     PetscCall(MatPreallocateSet(i + rstart, apnz, current_space->array, dnz, onz));

286:     current_space->array = PetscSafePointerPlusOffset(current_space->array, apnz);
287:     current_space->local_used += apnz;
288:     current_space->local_remaining -= apnz;
289:   }

291:   /* Allocate space for apj, initialize apj, and */
292:   /* destroy list of free space and other temporary array(s) */
293:   PetscCall(PetscMalloc1(api[am], &ptap->apj));
294:   apj = ptap->apj;
295:   PetscCall(PetscFreeSpaceContiguous(&free_space, ptap->apj));
296:   PetscCall(PetscLLDestroy(lnk, lnkbt));

298:   /* malloc apa to store dense row A[i,:]*P */
299:   PetscCall(PetscCalloc1(pN, &ptap->apa));

301:   /* set and assemble symbolic parallel matrix C */
302:   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
303:   PetscCall(MatSetBlockSizesFromMats(C, A, P));

305:   PetscCall(MatGetType(A, &mtype));
306:   PetscCall(MatSetType(C, mtype));
307:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
308:   MatPreallocateEnd(dnz, onz);

310:   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
311:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
312:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
313:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
314:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));

316:   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;
317:   C->ops->productnumeric = MatProductNumeric_AB;

319:   /* attach the supporting struct to C for reuse */
320:   C->product->data    = ptap;
321:   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;

323:   /* set MatInfo */
324:   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
325:   if (afill < 1.0) afill = 1.0;
326:   C->info.mallocs           = nspacedouble;
327:   C->info.fill_ratio_given  = fill;
328:   C->info.fill_ratio_needed = afill;

330:   if (PetscDefined(USE_INFO)) {
331:     if (api[am]) {
332:       PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
333:       PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
334:     } else PetscCall(PetscInfo(C, "Empty matrix product\n"));
335:   }
336:   PetscFunctionReturn(PETSC_SUCCESS);
337: }

339: static PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIDense(Mat, Mat, PetscReal, Mat);
340: static PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIDense(Mat, Mat, Mat);

342: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense_AB(Mat C)
343: {
344:   Mat_Product *product = C->product;
345:   Mat          A = product->A, B = product->B;

347:   PetscFunctionBegin;
348:   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend)
349:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->cmap->rstart, A->cmap->rend, B->rmap->rstart, B->rmap->rend);

351:   C->ops->matmultsymbolic = MatMatMultSymbolic_MPIAIJ_MPIDense;
352:   C->ops->productsymbolic = MatProductSymbolic_AB;
353:   PetscFunctionReturn(PETSC_SUCCESS);
354: }

356: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense_AtB(Mat C)
357: {
358:   Mat_Product *product = C->product;
359:   Mat          A = product->A, B = product->B;

361:   PetscFunctionBegin;
362:   if (A->rmap->rstart != B->rmap->rstart || A->rmap->rend != B->rmap->rend)
363:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->rstart, A->rmap->rend, B->rmap->rstart, B->rmap->rend);

365:   C->ops->transposematmultsymbolic = MatTransposeMatMultSymbolic_MPIAIJ_MPIDense;
366:   C->ops->productsymbolic          = MatProductSymbolic_AtB;
367:   PetscFunctionReturn(PETSC_SUCCESS);
368: }

370: PETSC_INTERN PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense(Mat C)
371: {
372:   Mat_Product *product = C->product;

374:   PetscFunctionBegin;
375:   switch (product->type) {
376:   case MATPRODUCT_AB:
377:     PetscCall(MatProductSetFromOptions_MPIAIJ_MPIDense_AB(C));
378:     break;
379:   case MATPRODUCT_AtB:
380:     PetscCall(MatProductSetFromOptions_MPIAIJ_MPIDense_AtB(C));
381:     break;
382:   default:
383:     break;
384:   }
385:   PetscFunctionReturn(PETSC_SUCCESS);
386: }

388: PETSC_INTERN PetscErrorCode MatMPIDenseScatterDestroy_Private(MPIAIJ_MPIDense *contents)
389: {
390:   PetscFunctionBegin;
391:   PetscCall(MatDestroy(&contents->workB));
392:   PetscCall(PetscSFDestroy(&contents->sf[0]));
393:   PetscCall(PetscSFDestroy(&contents->sf[1]));
394:   for (PetscInt i = 0; i < contents->nsends; i++) PetscCallMPI(MPI_Type_free(&contents->stype[i]));
395:   for (PetscInt i = 0; i < contents->nrecvs; i++) PetscCallMPI(MPI_Type_free(&contents->rtype[i]));
396:   PetscCall(PetscFree4(contents->stype, contents->rtype, contents->rwaits, contents->swaits));
397:   PetscFunctionReturn(PETSC_SUCCESS);
398: }

400: typedef struct {
401:   MPIAIJ_MPIDense scatter;
402:   Mat             workC; /* off-diagonal contribution A_o * workB on the device route, NULL otherwise */
403: } MPIAIJ_MPIDense_AB;

405: static PetscErrorCode MatMPIAIJ_MPIDenseDestroy(PetscCtxRt ctx)
406: {
407:   MPIAIJ_MPIDense_AB *data = *(MPIAIJ_MPIDense_AB **)ctx;

409:   PetscFunctionBegin;
410:   PetscCall(MatDestroy(&data->workC));
411:   PetscCall(MatMPIDenseScatterDestroy_Private(&data->scatter));
412:   PetscCall(PetscFree(data));
413:   PetscFunctionReturn(PETSC_SUCCESS);
414: }

416: /* Creates the parts of the scatter that depend on contents->blda: the strided PetscSFs on the device, the send datatypes on the host */
417: static PetscErrorCode MatMPIDenseScatterSetUpLDA_Private(VecScatter ctx, PetscInt bs, Mat B, MPIAIJ_MPIDense *contents)
418: {
419:   PetscInt        nrows = contents->workB->rmap->n;
420:   MPI_Datatype    type1;
421:   const PetscInt *sindices, *sstarts;
422:   PetscMPIInt    *disp;
423:   PetscMPIInt     nsends, nrows_to, bs_mpi;

425:   PetscFunctionBegin;
426:   if (contents->ondevice) {
427:     PetscCheck(ctx->vscat.bs <= 1 || contents->blda % ctx->vscat.bs == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Leading dimension %" PetscInt_FMT " of the dense matrix must be a multiple of the block size %" PetscInt_FMT, contents->blda, ctx->vscat.bs);
428:     PetscCall(PetscSFCreateStridedSF(ctx, contents->ncols[0], contents->blda, nrows, &contents->sf[0]));
429:     if (contents->ncols[1] > 0) PetscCall(PetscSFCreateStridedSF(ctx, contents->ncols[1], contents->blda, nrows, &contents->sf[1]));
430:   } else {
431:     PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE, &nsends, &sstarts, &sindices, NULL, NULL));
432:     PetscCall(PetscMalloc1(PetscMax(B->rmap->n, 1), &disp));
433:     PetscCall(PetscMPIIntCast(bs, &bs_mpi));
434:     for (PetscMPIInt i = 0; i < nsends; i++) {
435:       PetscCall(PetscMPIIntCast(sstarts[i + 1] - sstarts[i], &nrows_to));
436:       for (PetscInt j = 0; j < nrows_to; j++) PetscCall(PetscMPIIntCast(sindices[sstarts[i] + j] * bs, &disp[j]));
437:       PetscCallMPI(MPI_Type_create_indexed_block(nrows_to, bs_mpi, disp, MPIU_SCALAR, &type1));
438:       PetscCallMPI(MPI_Type_create_resized(type1, 0, contents->blda * sizeof(PetscScalar), &contents->stype[i]));
439:       PetscCallMPI(MPI_Type_commit(&contents->stype[i]));
440:       PetscCallMPI(MPI_Type_free(&type1));
441:     }
442:     PetscCall(PetscFree(disp));
443:     PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE, &nsends, &sstarts, &sindices, NULL, NULL));
444:   }
445:   PetscFunctionReturn(PETSC_SUCCESS);
446: }

448: /* MatMPIDenseGetBatchSize_Private - Gets the number of columns of B to process at a time, to reduce the memory of a work matrix with nrows rows

450:    Collective

452:    Input Parameters:
453: +  nrows - number of rows of the work matrix on this process
454: .  Am    - number of local rows of the sparse matrix A of the product
455: .  B     - the MATMPIDENSE input matrix
456: -  C     - the product matrix, whose prefix is used for -matproduct_batch_size

458:    Output Parameters:
459: +  batchSize  - number of columns of B per batch; 0 or the number of columns of B means all the columns are processed at once
460: -  numBatches - number of full batches, or 0 if B is not split into batches; a smaller last batch holds the remaining columns

462:    Level: developer

464:    Note:
465:    Each process chooses a batch size that keeps its work matrix to about twice the memory of Am rows with all the columns of B,
466:    rounded down to a multiple of the column block size of B. A process with no work rows chooses all the columns. The largest
467:    choice over all processes is used, so B is split only if every process wants it split, unless -matproduct_batch_size gives another size.

469: .seealso: `MatMPIDenseScatterSetUp_Private()`, `MatTransposeMatMultSymbolic_MPIAIJ_MPIDense()`
470: */
471: PETSC_INTERN PetscErrorCode MatMPIDenseGetBatchSize_Private(PetscInt nrows, PetscInt Am, Mat B, Mat C, PetscInt *batchSize, PetscInt *numBatches)
472: {
473:   PetscInt BN = B->cmap->N, Bbn, Bbs, numBb;
474:   MPI_Comm comm;

476:   PetscFunctionBegin;
477:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
478:   if (nrows > 0) {
479:     Bbn = 2 * Am * BN / nrows;
480:     if (Bbn == 0) Bbn = 1;
481:   } else Bbn = BN;
482:   Bbs = B->cmap->bs;
483:   Bbn = Bbn / Bbs * Bbs;
484:   if (Bbn > BN) Bbn = BN;
485:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &Bbn, 1, MPIU_INT, MPI_MAX, comm));

487:   /* Enable runtime option for Bbn */
488:   PetscOptionsBegin(comm, ((PetscObject)C)->prefix, "MatProduct", "Mat");
489:   PetscCall(PetscOptionsDeprecated("-matmatmult_Bbn", "-matproduct_batch_size", "3.25", NULL));
490:   PetscCall(PetscOptionsBoundedInt("-matproduct_batch_size", "Number of dense columns per batch", "MatProduct", Bbn, &Bbn, NULL, 0));
491:   PetscOptionsEnd();
492:   Bbn = PetscMin(Bbn, BN);

494:   if (Bbn > 0 && Bbn < BN) numBb = BN / Bbn;
495:   else numBb = 0;
496:   if (numBb > 0) PetscCall(PetscInfo(C, "Using column batches of size %" PetscInt_FMT " for %" PetscInt_FMT " dense columns\n", Bbn, BN));
497:   *batchSize  = Bbn;
498:   *numBatches = numBb;
499:   PetscFunctionReturn(PETSC_SUCCESS);
500: }

502: PETSC_INTERN PetscErrorCode MatMPIDenseScatterSetUp_Private(VecScatter ctx, PetscInt nrows, PetscInt bs, PetscInt Am, Mat B, Mat C, MPIAIJ_MPIDense *contents, PetscInt *batchSize, PetscInt *numBatches)
503: {
504:   PetscInt        BN = B->cmap->N, Bbn, numBb, ncols;
505:   MPI_Datatype    type1;
506:   const PetscInt *rstarts;
507:   PetscMPIInt     nsends, nrecvs, nrows_from, disp = 0;
508:   PetscBool       flg;

510:   PetscFunctionBegin;
511:   PetscCall(MatDenseGetLDA(B, &contents->blda));
512:   PetscCall(PetscObjectGetId((PetscObject)B, &contents->bid));
513:   /* Create column block of B and C for memory scalability when BN is too large */
514:   PetscCall(MatMPIDenseGetBatchSize_Private(nrows, Am, B, C, &Bbn, &numBb));
515:   ncols = Bbn > 0 ? Bbn : BN;

517:   /* Create work matrix used to store off processor rows of B needed for local product, with the same type as the local block of B */
518:   PetscCall(MatCreate(PETSC_COMM_SELF, &contents->workB));
519:   PetscCall(MatSetSizes(contents->workB, nrows, ncols, nrows, ncols));
520:   PetscCall(MatSetType(contents->workB, ((PetscObject)((Mat_MPIDense *)B->data)->A)->type_name));
521:   PetscCall(MatSetUp(contents->workB));

523:   PetscCall(PetscObjectTypeCompare((PetscObject)((Mat_MPIDense *)B->data)->A, MATSEQDENSE, &flg));
524:   contents->ondevice = (PetscBool)!flg;
525:   if (contents->ondevice) {
526:     /* Use strided PetscSFs, which support device memory, instead of the MPI derived data types below */
527:     contents->ncols[0] = ncols;
528:     if (numBb > 0 && BN % Bbn != 0) contents->ncols[1] = BN % Bbn;
529:   } else {
530:     PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE, &nsends, NULL, NULL, NULL, NULL));
531:     PetscCall(VecScatterGetRemoteOrdered_Private(ctx, PETSC_FALSE, &nrecvs, &rstarts, NULL, NULL, NULL));

533:     /* Use MPI derived data type to reduce memory required by the send/recv buffers */
534:     PetscCall(PetscMalloc4(nsends, &contents->stype, nrecvs, &contents->rtype, nrecvs, &contents->rwaits, nsends, &contents->swaits));
535:     contents->nsends = nsends;
536:     contents->nrecvs = nrecvs;

538:     for (PetscMPIInt i = 0; i < nrecvs; i++) {
539:       /* received values from a process form a (nrows_from x Bbn) row block in workB (column-wise) */
540:       PetscCall(PetscMPIIntCast((rstarts[i + 1] - rstarts[i]) * bs, &nrows_from));
541:       PetscCallMPI(MPI_Type_create_indexed_block(1, nrows_from, &disp, MPIU_SCALAR, &type1));
542:       PetscCallMPI(MPI_Type_create_resized(type1, 0, nrows * sizeof(PetscScalar), &contents->rtype[i]));
543:       PetscCallMPI(MPI_Type_commit(&contents->rtype[i]));
544:       PetscCallMPI(MPI_Type_free(&type1));
545:     }

547:     PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, NULL, NULL, NULL, NULL));
548:     PetscCall(VecScatterRestoreRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, NULL, NULL));
549:   }
550:   PetscCall(MatMPIDenseScatterSetUpLDA_Private(ctx, bs, B, contents));
551:   if (batchSize) *batchSize = Bbn;
552:   if (numBatches) *numBatches = numBb;
553:   PetscFunctionReturn(PETSC_SUCCESS);
554: }

556: /* Recreates the parts of the scatter that depend on the leading dimension when a new input B has a different one */
557: PETSC_INTERN PetscErrorCode MatMPIDenseScatterUpdateLDA_Private(VecScatter ctx, PetscInt bs, Mat B, Mat C, MPIAIJ_MPIDense *contents)
558: {
559:   PetscObjectId id;
560:   PetscInt      blda;
561:   PetscBool     update;

563:   PetscFunctionBegin;
564:   PetscCall(PetscObjectGetId((PetscObject)B, &id));
565:   if (id == contents->bid) PetscFunctionReturn(PETSC_SUCCESS);
566:   PetscCall(MatDenseGetLDA(B, &blda));
567:   update = (PetscBool)(blda != contents->blda);
568:   if (contents->ondevice) PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &update, 1, MPI_C_BOOL, MPI_LOR, PetscObjectComm((PetscObject)C)));
569:   if (update) {
570:     PetscCall(PetscInfo(C, "Setting up the scatter again for a dense input with leading dimension %" PetscInt_FMT " instead of %" PetscInt_FMT "\n", blda, contents->blda));
571:     PetscCall(PetscSFDestroy(&contents->sf[0]));
572:     PetscCall(PetscSFDestroy(&contents->sf[1]));
573:     for (PetscInt i = 0; i < contents->nsends; i++) PetscCallMPI(MPI_Type_free(&contents->stype[i]));
574:     contents->blda = blda;
575:     PetscCall(MatMPIDenseScatterSetUpLDA_Private(ctx, bs, B, contents));
576:   }
577:   contents->bid = id;
578:   PetscFunctionReturn(PETSC_SUCCESS);
579: }

581: static PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIDense(Mat A, Mat B, PetscReal fill, Mat C)
582: {
583:   Mat_MPIAIJ         *aij = (Mat_MPIAIJ *)A->data;
584:   MPIAIJ_MPIDense_AB *data;
585:   PetscInt            nz  = aij->B->cmap->n;
586:   VecScatter          ctx = aij->Mvctx;
587:   PetscInt            Am = A->rmap->n, BN = B->cmap->N, Bbn, numBb;
588:   Mat                 workB1, workC1;
589:   const char         *ctype;
590:   PetscBool           cisdense;

592:   PetscFunctionBegin;
593:   MatCheckProduct(C, 4);
594:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
595:   PetscCall(PetscObjectBaseTypeCompare((PetscObject)C, MATMPIDENSE, &cisdense));
596:   if (!cisdense) {
597:     PetscCall(MatSetType(C, ((PetscObject)B)->type_name));
598:     PetscCall(MatSetVecType(C, B->defaultvectype));
599:   }
600:   PetscCall(MatSetSizes(C, Am, B->cmap->n, A->rmap->N, BN));
601:   PetscCall(MatSetBlockSizesFromMats(C, A, B));
602:   PetscCall(MatSetUp(C));
603:   /* The cuSPARSE and hipSPARSE symbolic below re-types a host local block of C in place, so capture the type
604:      of the local block of C now to give the work matrix the type the numeric will add it to */
605:   ctype = ((PetscObject)((Mat_MPIDense *)C->data)->A)->type_name;
606:   PetscCall(PetscNew(&data));
607:   PetscCall(MatMPIDenseScatterSetUp_Private(ctx, nz, 1, Am, B, C, &data->scatter, &Bbn, &numBb));
608:   PetscCall(MatProductClear(aij->A));
609:   PetscCall(MatProductClear(((Mat_MPIDense *)B->data)->A));
610:   PetscCall(MatProductClear(((Mat_MPIDense *)C->data)->A));
611:   if (data->scatter.ondevice && nz) {
612:     /* On the device route the off-diagonal contribution is computed into a work matrix and added to the local
613:        block of C, rather than accumulated in place by a host kernel */
614:     PetscCall(MatCreate(PETSC_COMM_SELF, &data->workC));
615:     PetscCall(MatSetSizes(data->workC, Am, Bbn ? Bbn : BN, Am, Bbn ? Bbn : BN));
616:     PetscCall(MatSetType(data->workC, ctype));
617:     PetscCall(MatSetUp(data->workC));
618:     PetscCall(MatProductCreateWithMat(aij->B, data->scatter.workB, NULL, data->workC));
619:     PetscCall(MatProductSetType(data->workC, MATPRODUCT_AB));
620:     PetscCall(MatProductSetFromOptions(data->workC));
621:     PetscCall(MatProductSymbolic(data->workC));
622:     if (numBb && BN % Bbn) {
623:       /* the last column batch is smaller, set up the product on the sub-matrices the numeric will use for it */
624:       PetscCall(MatDenseGetSubMatrix(data->scatter.workB, PETSC_DECIDE, PETSC_DECIDE, 0, BN % Bbn, &workB1));
625:       PetscCall(MatDenseGetSubMatrix(data->workC, PETSC_DECIDE, PETSC_DECIDE, 0, BN % Bbn, &workC1));
626:       PetscCall(MatProductCreateWithMat(aij->B, workB1, NULL, workC1));
627:       PetscCall(MatProductSetType(workC1, MATPRODUCT_AB));
628:       PetscCall(MatProductSetFromOptions(workC1));
629:       PetscCall(MatProductSymbolic(workC1));
630:       PetscCall(MatDenseRestoreSubMatrix(data->workC, &workC1));
631:       PetscCall(MatDenseRestoreSubMatrix(data->scatter.workB, &workB1));
632:     }
633:   }
634:   PetscCall(MatProductCreateWithMat(aij->A, ((Mat_MPIDense *)B->data)->A, NULL, ((Mat_MPIDense *)C->data)->A));
635:   PetscCall(MatProductSetType(((Mat_MPIDense *)C->data)->A, MATPRODUCT_AB));
636:   PetscCall(MatProductSetFromOptions(((Mat_MPIDense *)C->data)->A));
637:   PetscCall(MatProductSymbolic(((Mat_MPIDense *)C->data)->A));
638:   C->product->data       = data;
639:   C->product->destroy    = MatMPIAIJ_MPIDenseDestroy;
640:   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIDense;
641:   PetscFunctionReturn(PETSC_SUCCESS);
642: }

644: PETSC_INTERN PetscErrorCode MatMatMultNumericAdd_SeqAIJ_SeqDense(Mat, Mat, Mat, const PetscBool);

646: /*
647:     Performs an efficient scatter on the rows of B needed by this process; this is
648:     a modification of the VecScatterBegin_() routines.
649: */
650: static PetscErrorCode MatMPIDenseScatterHost_Private(VecScatter ctx, PetscInt bs, Mat workB, MPIAIJ_MPIDense *contents, Mat B, Mat C)
651: {
652:   const PetscScalar *b;
653:   PetscScalar       *rvalues;
654:   const PetscInt    *sindices, *sstarts, *rstarts;
655:   const PetscMPIInt *sprocs, *rprocs;
656:   PetscMPIInt        nsends, nrecvs;
657:   MPI_Comm           comm;
658:   PetscMPIInt        tag = ((PetscObject)ctx)->tag, ncols, nsends_mpi, nrecvs_mpi;

660:   PetscFunctionBegin;
661:   PetscCall(PetscMPIIntCast(B->cmap->N, &ncols));
662:   PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, &sprocs, NULL /*bs*/));
663:   PetscCall(VecScatterGetRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, &rprocs, NULL /*bs*/));
664:   PetscCall(PetscMPIIntCast(nsends, &nsends_mpi));
665:   PetscCall(PetscMPIIntCast(nrecvs, &nrecvs_mpi));

667:   PetscCall(MatDenseGetArrayRead(B, &b));
668:   PetscCall(MatDenseGetArray(workB, &rvalues));

670:   /* Post recv, use MPI derived data type to save memory */
671:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
672:   for (PetscMPIInt i = 0; i < nrecvs; i++) PetscCallMPI(MPIU_Irecv(rvalues + ((rstarts[i] - rstarts[0]) * bs), ncols, contents->rtype[i], rprocs[i], tag, comm, contents->rwaits + i));
673:   for (PetscMPIInt i = 0; i < nsends; i++) PetscCallMPI(MPIU_Isend(b, ncols, contents->stype[i], sprocs[i], tag, comm, contents->swaits + i));

675:   if (nrecvs) PetscCallMPI(MPI_Waitall(nrecvs_mpi, contents->rwaits, MPI_STATUSES_IGNORE));
676:   if (nsends) PetscCallMPI(MPI_Waitall(nsends_mpi, contents->swaits, MPI_STATUSES_IGNORE));

678:   PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, &sprocs, NULL));
679:   PetscCall(VecScatterRestoreRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, &rprocs, NULL));
680:   PetscCall(MatDenseRestoreArrayRead(B, &b));
681:   PetscCall(MatDenseRestoreArray(workB, &rvalues));
682:   PetscFunctionReturn(PETSC_SUCCESS);
683: }

685: /*
686:    Same as MatMPIDenseScatterHost_Private(), but using the strided PetscSFs set up in
687:    MatMPIDenseScatterSetUp_Private() so that the data never leaves the device. The scatter is split in two
688:    halves so that a caller can run other work while the off-process rows of B are in flight
689: */
690: static PetscErrorCode MatMPIDenseScatterDeviceBegin_Private(Mat workB, MPIAIJ_MPIDense *contents, Mat B)
691: {
692:   PetscSF      sf;
693:   PetscInt     k = 0;
694:   PetscMemType bmtype, wmtype;

696:   PetscFunctionBegin;
697:   PetscCheck(!contents->sfinuse, PETSC_COMM_SELF, PETSC_ERR_PLIB, "A scatter is already in flight");
698:   if (B->cmap->N != contents->ncols[0]) k = 1;
699:   PetscCheck(contents->sf[k] && contents->ncols[k] == B->cmap->N, PETSC_COMM_SELF, PETSC_ERR_PLIB, "No scatter set up for %" PetscInt_FMT " columns", B->cmap->N);
700:   sf = contents->sf[k];
701:   /* every entry of workB is overwritten, so write-only access is enough */
702:   PetscCall(MatDenseGetArrayReadAndMemType(B, &contents->barray, &bmtype));
703:   PetscCall(MatDenseGetArrayWriteAndMemType(workB, &contents->warray, &wmtype));
704:   PetscCall(PetscSFBcastWithMemTypeBegin(sf, sf->vscat.unit, bmtype, contents->barray, wmtype, contents->warray, MPI_REPLACE));
705:   contents->sfinuse = sf;
706:   PetscFunctionReturn(PETSC_SUCCESS);
707: }

709: static PetscErrorCode MatMPIDenseScatterDeviceEnd_Private(Mat workB, MPIAIJ_MPIDense *contents, Mat B)
710: {
711:   PetscSF sf = contents->sfinuse;

713:   PetscFunctionBegin;
714:   PetscCheck(sf, PETSC_COMM_SELF, PETSC_ERR_PLIB, "No scatter in flight");
715:   PetscCall(PetscSFBcastEnd(sf, sf->vscat.unit, contents->barray, contents->warray, MPI_REPLACE));
716:   PetscCall(MatDenseRestoreArrayWriteAndMemType(workB, &contents->warray));
717:   PetscCall(MatDenseRestoreArrayReadAndMemType(B, &contents->barray));
718:   contents->sfinuse = NULL;
719:   PetscFunctionReturn(PETSC_SUCCESS);
720: }

722: /*
723:    The checks the host and device scatters share; on the device route they are done by the begin half
724: */
725: static PetscErrorCode MatMPIDenseScatterCheck_Private(PetscInt nrows, Mat workB, MPIAIJ_MPIDense *contents, Mat B, Mat C)
726: {
727:   PetscInt blda;

729:   PetscFunctionBegin;
730:   MatCheckProduct(C, 5);
731:   PetscCheck(C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
732:   PetscCheck(nrows == workB->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of rows of workB %" PetscInt_FMT " not equal to columns of off-diagonal block %" PetscInt_FMT, workB->rmap->n, nrows);
733:   PetscCall(MatDenseGetLDA(B, &blda));
734:   PetscCheck(blda == contents->blda, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cannot reuse an input matrix with lda %" PetscInt_FMT " != %" PetscInt_FMT, blda, contents->blda);
735:   PetscFunctionReturn(PETSC_SUCCESS);
736: }

738: PETSC_INTERN PetscErrorCode MatMPIDenseScatter_Private(VecScatter ctx, PetscInt nrows, PetscInt bs, Mat workB, MPIAIJ_MPIDense *contents, Mat B, Mat C)
739: {
740:   PetscFunctionBegin;
741:   PetscCall(MatMPIDenseScatterCheck_Private(nrows, workB, contents, B, C));
742:   if (contents->ondevice) {
743:     PetscCall(MatMPIDenseScatterDeviceBegin_Private(workB, contents, B));
744:     PetscCall(MatMPIDenseScatterDeviceEnd_Private(workB, contents, B));
745:   } else PetscCall(MatMPIDenseScatterHost_Private(ctx, bs, workB, contents, B, C));
746:   PetscFunctionReturn(PETSC_SUCCESS);
747: }

749: /*
750:    Starts the scatter of the off-process rows of B into workB. On the device route only the begin half of the
751:    PetscSF broadcast is posted, so the caller must complete it with MatMPIDenseScatterEnd(); the host scatter
752:    is blocking and is done entirely here
753: */
754: static PetscErrorCode MatMPIDenseScatterBegin(Mat A, Mat B, Mat workB, Mat C)
755: {
756:   Mat_MPIAIJ      *aij      = (Mat_MPIAIJ *)A->data;
757:   MPIAIJ_MPIDense *contents = &((MPIAIJ_MPIDense_AB *)C->product->data)->scatter;

759:   PetscFunctionBegin;
760:   if (contents->ondevice) {
761:     PetscCall(MatMPIDenseScatterCheck_Private(aij->B->cmap->n, workB, contents, B, C));
762:     PetscCall(MatMPIDenseScatterDeviceBegin_Private(workB, contents, B));
763:   } else PetscCall(MatMPIDenseScatter_Private(aij->Mvctx, aij->B->cmap->n, 1, workB, contents, B, C));
764:   PetscFunctionReturn(PETSC_SUCCESS);
765: }

767: static PetscErrorCode MatMPIDenseScatterEnd(Mat B, Mat workB, Mat C)
768: {
769:   MPIAIJ_MPIDense *contents = &((MPIAIJ_MPIDense_AB *)C->product->data)->scatter;

771:   PetscFunctionBegin;
772:   if (contents->ondevice) PetscCall(MatMPIDenseScatterDeviceEnd_Private(workB, contents, B));
773:   PetscFunctionReturn(PETSC_SUCCESS);
774: }

776: /* MatMPIAIJ_MPIDenseProductNumeric_Private - Computes C = A B or C = A^T B for the sequential matrices inside a MATMPIAIJ times MATMPIDENSE product

778:    Not Collective

780:    Input Parameters:
781: +  A     - a diagonal or off-diagonal block of the MATMPIAIJ matrix
782: .  B     - the sequential dense input: the local block of B, one batch of its columns, or the off-process rows of B
783: .  C     - the sequential dense result, whose product is set up here if it has none
784: .  ptype - MATPRODUCT_AB or MATPRODUCT_AtB
785: -  clear - whether to clear the product of C after the numeric phase, so that the next call sets it up again

787:    Level: developer

789:    Note:
790:    The product is also set up again when A is not the matrix it was set up with, since its symbolic phase may keep data built from A.

792: .seealso: `MatMatMultNumeric_MPIAIJ_MPIDense()`, `MatTransposeMatMultNumeric_MPIAIJ_MPIDense()`, `MatProductClear()`
793: */
794: PETSC_INTERN PetscErrorCode MatMPIAIJ_MPIDenseProductNumeric_Private(Mat A, Mat B, Mat C, MatProductType ptype, PetscBool clear)
795: {
796:   PetscFunctionBegin;
797:   if (C->product != NULL && C->product->A != A) PetscCall(MatProductClear(C));
798:   if (C->product == NULL) {
799:     PetscCall(MatProductCreateWithMat(A, B, NULL, C));
800:     PetscCall(MatProductSetType(C, ptype));
801:     PetscCall(MatProductSetFromOptions(C));
802:     PetscCall(MatProductSymbolic(C));
803:   } else PetscCall(MatProductReplaceMats(A, B, NULL, C));
804:   if (clear && !C->product->clear) C->product->clear = PETSC_TRUE;
805:   PetscCall(MatProductNumeric(C));
806:   PetscFunctionReturn(PETSC_SUCCESS);
807: }

809: static PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIDense(Mat A, Mat B, Mat C)
810: {
811:   Mat_MPIAIJ         *aij    = (Mat_MPIAIJ *)A->data;
812:   Mat_MPIDense       *bdense = (Mat_MPIDense *)B->data;
813:   Mat_MPIDense       *cdense = (Mat_MPIDense *)C->data;
814:   Mat                 workB;
815:   MPIAIJ_MPIDense    *contents;
816:   MPIAIJ_MPIDense_AB *data;
817:   PetscBool           clear = PETSC_FALSE, flg, overlap;

819:   PetscFunctionBegin;
820:   MatCheckProduct(C, 3);
821:   PetscCheck(C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
822:   data     = (MPIAIJ_MPIDense_AB *)C->product->data;
823:   contents = &data->scatter;
824:   if (PetscDefined(HAVE_CUPM)) {
825:     PetscCall(PetscObjectTypeCompare((PetscObject)C, MATMPIDENSE, &flg));
826:     if (flg) PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMPIAIJ, &flg));
827:     clear = (PetscBool)!flg; /* if either A or C is a device Mat, make sure MatProductClear() is called */
828:   }
829:   /* The device scatter is non-blocking, so when there are no column batches start it before the product of the
830:      diagonal block below to overlap the communication with that product, as MatMult_MPIAIJ() does. The host
831:      scatter is blocking, so it is left where it is */
832:   PetscCall(MatMPIDenseScatterUpdateLDA_Private(aij->Mvctx, 1, B, C, contents));
833:   overlap = (PetscBool)(contents->ondevice && contents->workB->cmap->n == B->cmap->N);
834:   if (overlap) PetscCall(MatMPIDenseScatterBegin(A, B, contents->workB, C));
835:   /* diagonal block of A times all local rows of B, first make sure that everything is up-to-date */
836:   PetscCall(MatMPIAIJ_MPIDenseProductNumeric_Private(aij->A, bdense->A, cdense->A, MATPRODUCT_AB, clear));
837:   if (contents->workB->cmap->n == B->cmap->N) {
838:     /* get off processor parts of B needed to complete C=A*B */
839:     workB = contents->workB;
840:     if (!overlap) PetscCall(MatMPIDenseScatterBegin(A, B, workB, C));
841:     PetscCall(MatMPIDenseScatterEnd(B, workB, C));

843:     /* off-diagonal block of A times nonlocal rows of B */
844:     if (data->workC) {
845:       PetscCall(MatMPIAIJ_MPIDenseProductNumeric_Private(aij->B, workB, data->workC, MATPRODUCT_AB, clear));
846:       PetscCall(MatAXPY(cdense->A, 1.0, data->workC, SAME_NONZERO_PATTERN));
847:     } else if (!contents->ondevice) PetscCall(MatMatMultNumericAdd_SeqAIJ_SeqDense(aij->B, workB, cdense->A, PETSC_TRUE)); /* the device route has no work matrix only when the off-diagonal block has no columns */
848:   } else {
849:     Mat       Bb, Cb, workC;
850:     PetscInt  BN = B->cmap->N, n = contents->workB->cmap->n, cols;
851:     PetscBool ccpu = PETSC_FALSE;

853:     PetscCheck(n > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Column block size %" PetscInt_FMT " must be positive", n);
854:     /* The host route accumulates into the local block of C on the host, bind C to the CPU to avoid copies back
855:        and forth from the device when getting and restoring the sub-matrices */
856:     if (!contents->ondevice) {
857:       PetscCall(MatBoundToCPU(C, &ccpu));
858:       PetscCall(MatBindToCPU(C, PETSC_TRUE));
859:     }
860:     for (PetscInt i = 0; i < BN; i += n) {
861:       cols  = PetscMin(n, BN - i);
862:       workB = contents->workB;
863:       workC = data->workC;
864:       if (cols != n) {
865:         PetscCall(MatDenseGetSubMatrix(contents->workB, PETSC_DECIDE, PETSC_DECIDE, 0, cols, &workB));
866:         if (workC) PetscCall(MatDenseGetSubMatrix(data->workC, PETSC_DECIDE, PETSC_DECIDE, 0, cols, &workC));
867:       }
868:       PetscCall(MatDenseGetSubMatrix(B, PETSC_DECIDE, PETSC_DECIDE, i, i + cols, &Bb));
869:       PetscCall(MatDenseGetSubMatrix(C, PETSC_DECIDE, PETSC_DECIDE, i, i + cols, &Cb));

871:       /* get off processor parts of B needed to complete C=A*B */
872:       PetscCall(MatMPIDenseScatterBegin(A, Bb, workB, C));
873:       PetscCall(MatMPIDenseScatterEnd(Bb, workB, C));

875:       /* off-diagonal block of A times nonlocal rows of B */
876:       if (workC) {
877:         PetscCall(MatMPIAIJ_MPIDenseProductNumeric_Private(aij->B, workB, workC, MATPRODUCT_AB, clear));
878:         PetscCall(MatAXPY(((Mat_MPIDense *)Cb->data)->A, 1.0, workC, SAME_NONZERO_PATTERN));
879:       } else if (!contents->ondevice) PetscCall(MatMatMultNumericAdd_SeqAIJ_SeqDense(aij->B, workB, ((Mat_MPIDense *)Cb->data)->A, PETSC_TRUE));
880:       if (cols != n) {
881:         if (workC) PetscCall(MatDenseRestoreSubMatrix(data->workC, &workC));
882:         PetscCall(MatDenseRestoreSubMatrix(contents->workB, &workB));
883:       }
884:       PetscCall(MatDenseRestoreSubMatrix(B, &Bb));
885:       PetscCall(MatDenseRestoreSubMatrix(C, &Cb));
886:     }
887:     if (!contents->ondevice) PetscCall(MatBindToCPU(C, ccpu));
888:   }
889:   PetscFunctionReturn(PETSC_SUCCESS);
890: }

892: PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ(Mat A, Mat P, Mat C)
893: {
894:   Mat_MPIAIJ          *a = (Mat_MPIAIJ *)A->data, *c = (Mat_MPIAIJ *)C->data;
895:   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data;
896:   Mat_SeqAIJ          *cd = (Mat_SeqAIJ *)c->A->data, *co = (Mat_SeqAIJ *)c->B->data;
897:   PetscInt            *adi = ad->i, *adj, *aoi = ao->i, *aoj;
898:   PetscScalar         *ada, *aoa, *cda = cd->a, *coa = co->a;
899:   Mat_SeqAIJ          *p_loc, *p_oth;
900:   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *pj;
901:   PetscScalar         *pa_loc, *pa_oth, *pa, valtmp, *ca;
902:   PetscInt             cm = C->rmap->n, anz, pnz;
903:   MatProductCtx_APMPI *ptap;
904:   PetscScalar         *apa_sparse;
905:   const PetscScalar   *dummy;
906:   PetscInt            *api, *apj, *apJ, i, j, k, row;
907:   PetscInt             cstart = C->cmap->rstart;
908:   PetscInt             cdnz, conz, k0, k1, nextp;
909:   MPI_Comm             comm;
910:   PetscMPIInt          size;

912:   PetscFunctionBegin;
913:   MatCheckProduct(C, 3);
914:   ptap = (MatProductCtx_APMPI *)C->product->data;
915:   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
916:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
917:   PetscCallMPI(MPI_Comm_size(comm, &size));
918:   PetscCheck(ptap->P_oth || size <= 1, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "AP cannot be reused. Do not call MatProductClear()");

920:   /* flag CPU mask for C */
921: #if PetscDefined(HAVE_DEVICE)
922:   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
923:   if (c->A->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->A->offloadmask = PETSC_OFFLOAD_CPU;
924:   if (c->B->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->B->offloadmask = PETSC_OFFLOAD_CPU;
925: #endif
926:   apa_sparse = ptap->apa;

928:   /* 1) get P_oth = ptap->P_oth  and P_loc = ptap->P_loc */
929:   /* update numerical values of P_oth and P_loc */
930:   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_REUSE_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
931:   PetscCall(MatMPIAIJGetLocalMat(P, MAT_REUSE_MATRIX, &ptap->P_loc));

933:   /* 2) compute numeric C_loc = A_loc*P = Ad*P_loc + Ao*P_oth */
934:   /* get data from symbolic products */
935:   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
936:   pi_loc = p_loc->i;
937:   pj_loc = p_loc->j;
938:   pa_loc = p_loc->a;
939:   if (size > 1) {
940:     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
941:     pi_oth = p_oth->i;
942:     pj_oth = p_oth->j;
943:     pa_oth = p_oth->a;
944:   } else {
945:     p_oth  = NULL;
946:     pi_oth = NULL;
947:     pj_oth = NULL;
948:     pa_oth = NULL;
949:   }

951:   /* trigger copy to CPU */
952:   PetscCall(MatSeqAIJGetArrayRead(a->A, &dummy));
953:   PetscCall(MatSeqAIJRestoreArrayRead(a->A, &dummy));
954:   PetscCall(MatSeqAIJGetArrayRead(a->B, &dummy));
955:   PetscCall(MatSeqAIJRestoreArrayRead(a->B, &dummy));
956:   api = ptap->api;
957:   apj = ptap->apj;
958:   for (i = 0; i < cm; i++) {
959:     apJ = apj + api[i];

961:     /* diagonal portion of A */
962:     anz = adi[i + 1] - adi[i];
963:     adj = ad->j + adi[i];
964:     ada = ad->a + adi[i];
965:     for (j = 0; j < anz; j++) {
966:       row = adj[j];
967:       pnz = pi_loc[row + 1] - pi_loc[row];
968:       pj  = pj_loc + pi_loc[row];
969:       pa  = pa_loc + pi_loc[row];
970:       /* perform sparse axpy */
971:       valtmp = ada[j];
972:       nextp  = 0;
973:       for (k = 0; nextp < pnz; k++) {
974:         if (apJ[k] == pj[nextp]) { /* column of AP == column of P */
975:           apa_sparse[k] += valtmp * pa[nextp++];
976:         }
977:       }
978:       PetscCall(PetscLogFlops(2.0 * pnz));
979:     }

981:     /* off-diagonal portion of A */
982:     anz = aoi[i + 1] - aoi[i];
983:     aoj = PetscSafePointerPlusOffset(ao->j, aoi[i]);
984:     aoa = PetscSafePointerPlusOffset(ao->a, aoi[i]);
985:     for (j = 0; j < anz; j++) {
986:       row = aoj[j];
987:       pnz = pi_oth[row + 1] - pi_oth[row];
988:       pj  = pj_oth + pi_oth[row];
989:       pa  = pa_oth + pi_oth[row];
990:       /* perform sparse axpy */
991:       valtmp = aoa[j];
992:       nextp  = 0;
993:       for (k = 0; nextp < pnz; k++) {
994:         if (apJ[k] == pj[nextp]) { /* column of AP == column of P */
995:           apa_sparse[k] += valtmp * pa[nextp++];
996:         }
997:       }
998:       PetscCall(PetscLogFlops(2.0 * pnz));
999:     }

1001:     /* set values in C */
1002:     cdnz = cd->i[i + 1] - cd->i[i];
1003:     conz = co->i[i + 1] - co->i[i];

1005:     /* 1st off-diagonal part of C */
1006:     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
1007:     k  = 0;
1008:     for (k0 = 0; k0 < conz; k0++) {
1009:       if (apJ[k] >= cstart) break;
1010:       ca[k0]        = apa_sparse[k];
1011:       apa_sparse[k] = 0.0;
1012:       k++;
1013:     }

1015:     /* diagonal part of C */
1016:     ca = cda + cd->i[i];
1017:     for (k1 = 0; k1 < cdnz; k1++) {
1018:       ca[k1]        = apa_sparse[k];
1019:       apa_sparse[k] = 0.0;
1020:       k++;
1021:     }

1023:     /* 2nd off-diagonal part of C */
1024:     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
1025:     for (; k0 < conz; k0++) {
1026:       ca[k0]        = apa_sparse[k];
1027:       apa_sparse[k] = 0.0;
1028:       k++;
1029:     }
1030:   }
1031:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1032:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1033:   PetscFunctionReturn(PETSC_SUCCESS);
1034: }

1036: /* same as MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(), except using LLCondensed to avoid O(BN) memory requirement */
1037: PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ(Mat A, Mat P, PetscReal fill, Mat C)
1038: {
1039:   MPI_Comm             comm;
1040:   PetscMPIInt          size;
1041:   MatProductCtx_APMPI *ptap;
1042:   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
1043:   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
1044:   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc, *p_oth;
1045:   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *dnz, *onz;
1046:   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, *aoj = ao->j, rstart = A->rmap->rstart;
1047:   PetscInt             i, pnz, row, *api, *apj, *Jptr, apnz, nspacedouble = 0, j, nzi, *lnk, apnz_max = 1;
1048:   PetscInt             am = A->rmap->n, pn = P->cmap->n, pm = P->rmap->n, lsize = pn + 20;
1049:   PetscReal            afill;
1050:   MatType              mtype;

1052:   PetscFunctionBegin;
1053:   MatCheckProduct(C, 4);
1054:   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
1055:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1056:   PetscCallMPI(MPI_Comm_size(comm, &size));

1058:   /* create struct MatProductCtx_APMPI and attached it to C later */
1059:   PetscCall(PetscNew(&ptap));

1061:   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
1062:   PetscCall(MatGetBrowsOfAoCols_MPIAIJ_Private(A, P, MAT_INITIAL_MATRIX, C->structure_only, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));

1064:   /* get P_loc by taking all local rows of P */
1065:   PetscCall(MatMPIAIJGetLocalMat_Private(P, MAT_INITIAL_MATRIX, C->structure_only, &ptap->P_loc));

1067:   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
1068:   pi_loc = p_loc->i;
1069:   pj_loc = p_loc->j;
1070:   if (size > 1) {
1071:     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
1072:     pi_oth = p_oth->i;
1073:     pj_oth = p_oth->j;
1074:   } else {
1075:     p_oth  = NULL;
1076:     pi_oth = NULL;
1077:     pj_oth = NULL;
1078:   }

1080:   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
1081:   PetscCall(PetscMalloc1(am + 1, &api));
1082:   ptap->api = api;
1083:   api[0]    = 0;

1085:   PetscCall(PetscLLCondensedCreate_Scalable(lsize, &lnk));

1087:   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
1088:   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space));
1089:   current_space = free_space;
1090:   MatPreallocateBegin(comm, am, pn, dnz, onz);
1091:   for (i = 0; i < am; i++) {
1092:     /* diagonal portion of A */
1093:     nzi = adi[i + 1] - adi[i];
1094:     for (j = 0; j < nzi; j++) {
1095:       row  = *adj++;
1096:       pnz  = pi_loc[row + 1] - pi_loc[row];
1097:       Jptr = pj_loc + pi_loc[row];
1098:       /* Expand list if it is not long enough */
1099:       if (pnz + apnz_max > lsize) {
1100:         lsize = pnz + apnz_max;
1101:         PetscCall(PetscLLCondensedExpand_Scalable(lsize, &lnk));
1102:       }
1103:       /* add non-zero cols of P into the sorted linked list lnk */
1104:       PetscCall(PetscLLCondensedAddSorted_Scalable(pnz, Jptr, lnk));
1105:       apnz       = *lnk; /* The first element in the list is the number of items in the list */
1106:       api[i + 1] = api[i] + apnz;
1107:       if (apnz > apnz_max) apnz_max = apnz + 1; /* '1' for diagonal entry */
1108:     }
1109:     /* off-diagonal portion of A */
1110:     nzi = aoi[i + 1] - aoi[i];
1111:     for (j = 0; j < nzi; j++) {
1112:       row  = *aoj++;
1113:       pnz  = pi_oth[row + 1] - pi_oth[row];
1114:       Jptr = pj_oth + pi_oth[row];
1115:       /* Expand list if it is not long enough */
1116:       if (pnz + apnz_max > lsize) {
1117:         lsize = pnz + apnz_max;
1118:         PetscCall(PetscLLCondensedExpand_Scalable(lsize, &lnk));
1119:       }
1120:       /* add non-zero cols of P into the sorted linked list lnk */
1121:       PetscCall(PetscLLCondensedAddSorted_Scalable(pnz, Jptr, lnk));
1122:       apnz       = *lnk; /* The first element in the list is the number of items in the list */
1123:       api[i + 1] = api[i] + apnz;
1124:       if (apnz > apnz_max) apnz_max = apnz + 1; /* '1' for diagonal entry */
1125:     }

1127:     /* add missing diagonal entry */
1128:     if (C->force_diagonals) {
1129:       j = i + rstart; /* column index */
1130:       PetscCall(PetscLLCondensedAddSorted_Scalable(1, &j, lnk));
1131:     }

1133:     apnz       = *lnk;
1134:     api[i + 1] = api[i] + apnz;
1135:     if (apnz > apnz_max) apnz_max = apnz;

1137:     /* if free space is not available, double the total space in the list */
1138:     if (current_space->local_remaining < apnz) {
1139:       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(apnz, current_space->total_array_size), &current_space));
1140:       nspacedouble++;
1141:     }

1143:     /* Copy data into free space, then initialize lnk */
1144:     PetscCall(PetscLLCondensedClean_Scalable(apnz, current_space->array, lnk));
1145:     PetscCall(MatPreallocateSet(i + rstart, apnz, current_space->array, dnz, onz));

1147:     current_space->array += apnz;
1148:     current_space->local_used += apnz;
1149:     current_space->local_remaining -= apnz;
1150:   }

1152:   /* Allocate space for apj, initialize apj, and */
1153:   /* destroy list of free space and other temporary array(s) */
1154:   PetscCall(PetscMalloc1(api[am], &ptap->apj));
1155:   apj = ptap->apj;
1156:   PetscCall(PetscFreeSpaceContiguous(&free_space, ptap->apj));
1157:   PetscCall(PetscLLCondensedDestroy_Scalable(lnk));

1159:   /* create and assemble symbolic parallel matrix C */
1160:   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
1161:   PetscCall(MatSetBlockSizesFromMats(C, A, P));
1162:   PetscCall(MatGetType(A, &mtype));
1163:   PetscCall(MatSetType(C, C->structure_only ? MATMPIAIJ : mtype));
1164:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
1165:   MatPreallocateEnd(dnz, onz);

1167:   /* malloc apa for assembly C */
1168:   if (!C->structure_only) PetscCall(PetscCalloc1(apnz_max, &ptap->apa));

1170:   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
1171:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
1172:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1173:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1174:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));

1176:   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ;
1177:   C->ops->productnumeric = MatProductNumeric_AB;

1179:   /* attach the supporting struct to C for reuse */
1180:   C->product->data    = ptap;
1181:   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;

1183:   /* set MatInfo */
1184:   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
1185:   if (afill < 1.0) afill = 1.0;
1186:   C->info.mallocs           = nspacedouble;
1187:   C->info.fill_ratio_given  = fill;
1188:   C->info.fill_ratio_needed = afill;

1190:   if (PetscDefined(USE_INFO)) {
1191:     if (api[am]) {
1192:       PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
1193:       PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
1194:     } else PetscCall(PetscInfo(C, "Empty matrix product\n"));
1195:   }
1196:   PetscFunctionReturn(PETSC_SUCCESS);
1197: }

1199: /* This function is needed for the seqMPI matrix-matrix multiplication.  */
1200: /* Three input arrays are merged to one output array. The size of the    */
1201: /* output array is also output. Duplicate entries only show up once.     */
1202: static void Merge3SortedArrays(PetscInt size1, PetscInt *in1, PetscInt size2, PetscInt *in2, PetscInt size3, PetscInt *in3, PetscInt *size4, PetscInt *out)
1203: {
1204:   int i = 0, j = 0, k = 0, l = 0;

1206:   /* Traverse all three arrays */
1207:   while (i < size1 && j < size2 && k < size3) {
1208:     if (in1[i] < in2[j] && in1[i] < in3[k]) {
1209:       out[l++] = in1[i++];
1210:     } else if (in2[j] < in1[i] && in2[j] < in3[k]) {
1211:       out[l++] = in2[j++];
1212:     } else if (in3[k] < in1[i] && in3[k] < in2[j]) {
1213:       out[l++] = in3[k++];
1214:     } else if (in1[i] == in2[j] && in1[i] < in3[k]) {
1215:       out[l++] = in1[i];
1216:       i++, j++;
1217:     } else if (in1[i] == in3[k] && in1[i] < in2[j]) {
1218:       out[l++] = in1[i];
1219:       i++, k++;
1220:     } else if (in3[k] == in2[j] && in2[j] < in1[i]) {
1221:       out[l++] = in2[j];
1222:       k++, j++;
1223:     } else if (in1[i] == in2[j] && in1[i] == in3[k]) {
1224:       out[l++] = in1[i];
1225:       i++, j++, k++;
1226:     }
1227:   }

1229:   /* Traverse two remaining arrays */
1230:   while (i < size1 && j < size2) {
1231:     if (in1[i] < in2[j]) {
1232:       out[l++] = in1[i++];
1233:     } else if (in1[i] > in2[j]) {
1234:       out[l++] = in2[j++];
1235:     } else {
1236:       out[l++] = in1[i];
1237:       i++, j++;
1238:     }
1239:   }

1241:   while (i < size1 && k < size3) {
1242:     if (in1[i] < in3[k]) {
1243:       out[l++] = in1[i++];
1244:     } else if (in1[i] > in3[k]) {
1245:       out[l++] = in3[k++];
1246:     } else {
1247:       out[l++] = in1[i];
1248:       i++, k++;
1249:     }
1250:   }

1252:   while (k < size3 && j < size2) {
1253:     if (in3[k] < in2[j]) {
1254:       out[l++] = in3[k++];
1255:     } else if (in3[k] > in2[j]) {
1256:       out[l++] = in2[j++];
1257:     } else {
1258:       out[l++] = in3[k];
1259:       k++, j++;
1260:     }
1261:   }

1263:   /* Traverse one remaining array */
1264:   while (i < size1) out[l++] = in1[i++];
1265:   while (j < size2) out[l++] = in2[j++];
1266:   while (k < size3) out[l++] = in3[k++];

1268:   *size4 = l;
1269: }

1271: /* This matrix-matrix multiplication algorithm divides the multiplication into three multiplications and  */
1272: /* adds up the products. Two of these three multiplications are performed with existing (sequential)      */
1273: /* matrix-matrix multiplications.  */
1274: PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ_seqMPI(Mat A, Mat P, PetscReal fill, Mat C)
1275: {
1276:   MPI_Comm             comm;
1277:   PetscMPIInt          size;
1278:   MatProductCtx_APMPI *ptap;
1279:   PetscFreeSpaceList   free_space_diag = NULL, current_space = NULL;
1280:   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
1281:   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc;
1282:   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data;
1283:   Mat_SeqAIJ          *adpd_seq, *p_off, *aopoth_seq;
1284:   PetscInt             adponz, adpdnz;
1285:   PetscInt            *pi_loc, *dnz, *onz;
1286:   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, rstart = A->rmap->rstart;
1287:   PetscInt            *lnk, i, i1 = 0, pnz, row, *adpoi, *adpoj, *api, *adpoJ, *aopJ, *apJ, *Jptr, aopnz, nspacedouble = 0, j, nzi, *apj, apnz, *adpdi, *adpdj, *adpdJ, *poff_i, *poff_j, *j_temp, *aopothi, *aopothj;
1288:   PetscInt             am = A->rmap->n, pN = P->cmap->N, pn = P->cmap->n, pm = P->rmap->n, p_colstart, p_colend;
1289:   PetscBT              lnkbt;
1290:   PetscReal            afill;
1291:   PetscMPIInt          rank;
1292:   Mat                  adpd, aopoth;
1293:   MatType              mtype;
1294:   const char          *prefix;

1296:   PetscFunctionBegin;
1297:   MatCheckProduct(C, 4);
1298:   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
1299:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1300:   PetscCallMPI(MPI_Comm_size(comm, &size));
1301:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1302:   PetscCall(MatGetOwnershipRangeColumn(P, &p_colstart, &p_colend));

1304:   /* create struct MatProductCtx_APMPI and attached it to C later */
1305:   PetscCall(PetscNew(&ptap));

1307:   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
1308:   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));

1310:   /* get P_loc by taking all local rows of P */
1311:   PetscCall(MatMPIAIJGetLocalMat(P, MAT_INITIAL_MATRIX, &ptap->P_loc));

1313:   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
1314:   pi_loc = p_loc->i;

1316:   /* Allocate memory for the i arrays of the matrices A*P, A_diag*P_off and A_offd * P */
1317:   PetscCall(PetscMalloc1(am + 1, &api));
1318:   PetscCall(PetscMalloc1(am + 1, &adpoi));

1320:   adpoi[0]  = 0;
1321:   ptap->api = api;
1322:   api[0]    = 0;

1324:   /* create and initialize a linked list, will be used for both A_diag * P_loc_off and A_offd * P_oth */
1325:   PetscCall(PetscLLCondensedCreate(pN, pN, &lnk, &lnkbt));
1326:   MatPreallocateBegin(comm, am, pn, dnz, onz);

1328:   /* Symbolic calc of A_loc_diag * P_loc_diag */
1329:   PetscCall(MatGetOptionsPrefix(A, &prefix));
1330:   PetscCall(MatProductCreate(a->A, p->A, NULL, &adpd));
1331:   PetscCall(MatGetOptionsPrefix(A, &prefix));
1332:   PetscCall(MatSetOptionsPrefix(adpd, prefix));
1333:   PetscCall(MatAppendOptionsPrefix(adpd, "inner_diag_"));

1335:   PetscCall(MatProductSetType(adpd, MATPRODUCT_AB));
1336:   PetscCall(MatProductSetAlgorithm(adpd, "sorted"));
1337:   PetscCall(MatProductSetFill(adpd, fill));
1338:   PetscCall(MatProductSetFromOptions(adpd));

1340:   adpd->force_diagonals = C->force_diagonals;
1341:   PetscCall(MatProductSymbolic(adpd));

1343:   adpd_seq = (Mat_SeqAIJ *)adpd->data;
1344:   adpdi    = adpd_seq->i;
1345:   adpdj    = adpd_seq->j;
1346:   p_off    = (Mat_SeqAIJ *)p->B->data;
1347:   poff_i   = p_off->i;
1348:   poff_j   = p_off->j;

1350:   /* j_temp stores indices of a result row before they are added to the linked list */
1351:   PetscCall(PetscMalloc1(pN, &j_temp));

1353:   /* Symbolic calc of the A_diag * p_loc_off */
1354:   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
1355:   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space_diag));
1356:   current_space = free_space_diag;

1358:   for (i = 0; i < am; i++) {
1359:     /* A_diag * P_loc_off */
1360:     nzi = adi[i + 1] - adi[i];
1361:     for (j = 0; j < nzi; j++) {
1362:       row  = *adj++;
1363:       pnz  = poff_i[row + 1] - poff_i[row];
1364:       Jptr = poff_j + poff_i[row];
1365:       for (i1 = 0; i1 < pnz; i1++) j_temp[i1] = p->garray[Jptr[i1]];
1366:       /* add non-zero cols of P into the sorted linked list lnk */
1367:       PetscCall(PetscLLCondensedAddSorted(pnz, j_temp, lnk, lnkbt));
1368:     }

1370:     adponz       = lnk[0];
1371:     adpoi[i + 1] = adpoi[i] + adponz;

1373:     /* if free space is not available, double the total space in the list */
1374:     if (current_space->local_remaining < adponz) {
1375:       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(adponz, current_space->total_array_size), &current_space));
1376:       nspacedouble++;
1377:     }

1379:     /* Copy data into free space, then initialize lnk */
1380:     PetscCall(PetscLLCondensedClean(pN, adponz, current_space->array, lnk, lnkbt));

1382:     current_space->array += adponz;
1383:     current_space->local_used += adponz;
1384:     current_space->local_remaining -= adponz;
1385:   }

1387:   /* Symbolic calc of A_off * P_oth */
1388:   PetscCall(MatSetOptionsPrefix(a->B, prefix));
1389:   PetscCall(MatAppendOptionsPrefix(a->B, "inner_offdiag_"));
1390:   PetscCall(MatCreate(PETSC_COMM_SELF, &aopoth));
1391:   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(a->B, ptap->P_oth, fill, aopoth));
1392:   aopoth_seq = (Mat_SeqAIJ *)aopoth->data;
1393:   aopothi    = aopoth_seq->i;
1394:   aopothj    = aopoth_seq->j;

1396:   /* Allocate space for apj, adpj, aopj, ... */
1397:   /* destroy lists of free space and other temporary array(s) */

1399:   PetscCall(PetscMalloc1(aopothi[am] + adpoi[am] + adpdi[am], &ptap->apj));
1400:   PetscCall(PetscMalloc1(adpoi[am], &adpoj));

1402:   /* Copy from linked list to j-array */
1403:   PetscCall(PetscFreeSpaceContiguous(&free_space_diag, adpoj));
1404:   PetscCall(PetscLLDestroy(lnk, lnkbt));

1406:   adpoJ = adpoj;
1407:   adpdJ = adpdj;
1408:   aopJ  = aopothj;
1409:   apj   = ptap->apj;
1410:   apJ   = apj; /* still empty */

1412:   /* Merge j-arrays of A_off * P, A_diag * P_loc_off, and */
1413:   /* A_diag * P_loc_diag to get A*P */
1414:   for (i = 0; i < am; i++) {
1415:     aopnz  = aopothi[i + 1] - aopothi[i];
1416:     adponz = adpoi[i + 1] - adpoi[i];
1417:     adpdnz = adpdi[i + 1] - adpdi[i];

1419:     /* Correct indices from A_diag*P_diag */
1420:     for (i1 = 0; i1 < adpdnz; i1++) adpdJ[i1] += p_colstart;
1421:     /* Merge j-arrays of A_diag * P_loc_off and A_diag * P_loc_diag and A_off * P_oth */
1422:     Merge3SortedArrays(adponz, adpoJ, adpdnz, adpdJ, aopnz, aopJ, &apnz, apJ);
1423:     PetscCall(MatPreallocateSet(i + rstart, apnz, apJ, dnz, onz));

1425:     aopJ += aopnz;
1426:     adpoJ += adponz;
1427:     adpdJ += adpdnz;
1428:     apJ += apnz;
1429:     api[i + 1] = api[i] + apnz;
1430:   }

1432:   /* malloc apa to store dense row A[i,:]*P */
1433:   PetscCall(PetscCalloc1(pN, &ptap->apa));

1435:   /* create and assemble symbolic parallel matrix C */
1436:   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
1437:   PetscCall(MatSetBlockSizesFromMats(C, A, P));
1438:   PetscCall(MatGetType(A, &mtype));
1439:   PetscCall(MatSetType(C, mtype));
1440:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
1441:   MatPreallocateEnd(dnz, onz);

1443:   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
1444:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
1445:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1446:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1447:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));

1449:   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;
1450:   C->ops->productnumeric = MatProductNumeric_AB;

1452:   /* attach the supporting struct to C for reuse */
1453:   C->product->data    = ptap;
1454:   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;

1456:   /* set MatInfo */
1457:   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
1458:   if (afill < 1.0) afill = 1.0;
1459:   C->info.mallocs           = nspacedouble;
1460:   C->info.fill_ratio_given  = fill;
1461:   C->info.fill_ratio_needed = afill;

1463:   if (PetscDefined(USE_INFO)) {
1464:     if (api[am]) {
1465:       PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
1466:       PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
1467:     } else PetscCall(PetscInfo(C, "Empty matrix product\n"));
1468:   }

1470:   PetscCall(MatDestroy(&aopoth));
1471:   PetscCall(MatDestroy(&adpd));
1472:   PetscCall(PetscFree(j_temp));
1473:   PetscCall(PetscFree(adpoj));
1474:   PetscCall(PetscFree(adpoi));
1475:   PetscFunctionReturn(PETSC_SUCCESS);
1476: }

1478: /* This routine only works when scall=MAT_REUSE_MATRIX! */
1479: PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_matmatmult(Mat P, Mat A, Mat C)
1480: {
1481:   MatProductCtx_APMPI *ptap;
1482:   Mat                  Pt;

1484:   PetscFunctionBegin;
1485:   MatCheckProduct(C, 3);
1486:   ptap = (MatProductCtx_APMPI *)C->product->data;
1487:   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
1488:   PetscCheck(ptap->Pt, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");

1490:   Pt = ptap->Pt;
1491:   PetscCall(MatTransposeSetPrecursor(P, Pt));
1492:   PetscCall(MatTranspose(P, MAT_REUSE_MATRIX, &Pt));
1493:   PetscCall(MatMatMultNumeric_MPIAIJ_MPIAIJ(Pt, A, C));
1494:   PetscFunctionReturn(PETSC_SUCCESS);
1495: }

1497: /* This routine is modified from MatPtAPSymbolic_MPIAIJ_MPIAIJ() */
1498: PetscErrorCode MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat P, Mat A, PetscReal fill, Mat C)
1499: {
1500:   MatProductCtx_APMPI     *ptap;
1501:   Mat_MPIAIJ              *p = (Mat_MPIAIJ *)P->data;
1502:   MPI_Comm                 comm;
1503:   PetscMPIInt              size, rank;
1504:   PetscFreeSpaceList       free_space = NULL, current_space = NULL;
1505:   PetscInt                 pn = P->cmap->n, aN = A->cmap->N, an = A->cmap->n;
1506:   PetscInt                *lnk, i, k, rstart;
1507:   PetscBT                  lnkbt;
1508:   PetscMPIInt              tagi, tagj, *len_si, *len_s, *len_ri, nrecv, proc, nsend;
1509:   PETSC_UNUSED PetscMPIInt icompleted = 0;
1510:   PetscInt               **buf_rj, **buf_ri, **buf_ri_k, row, ncols, *cols;
1511:   PetscInt                 len, *dnz, *onz, *owners, nzi;
1512:   PetscInt                 nrows, *buf_s, *buf_si, *buf_si_i, **nextrow, **nextci;
1513:   MPI_Request             *swaits, *rwaits;
1514:   MPI_Status              *sstatus, rstatus;
1515:   PetscLayout              rowmap;
1516:   PetscInt                *owners_co, *coi, *coj; /* i and j array of (p->B)^T*A*P - used in the communication */
1517:   PetscMPIInt             *len_r, *id_r;          /* array of length of comm->size, store send/recv matrix values */
1518:   PetscInt                *Jptr, *prmap = p->garray, con, j, Crmax;
1519:   Mat_SeqAIJ              *a_loc, *c_loc, *c_oth;
1520:   PetscHMapI               ta;
1521:   MatType                  mtype;
1522:   const char              *prefix;

1524:   PetscFunctionBegin;
1525:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1526:   PetscCallMPI(MPI_Comm_size(comm, &size));
1527:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

1529:   /* create symbolic parallel matrix C */
1530:   PetscCall(MatGetType(A, &mtype));
1531:   PetscCall(MatSetType(C, mtype));

1533:   C->ops->transposematmultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;

1535:   /* create struct MatProductCtx_APMPI and attached it to C later */
1536:   PetscCall(PetscNew(&ptap));

1538:   /* (0) compute Rd = Pd^T, Ro = Po^T  */
1539:   PetscCall(MatTranspose(p->A, MAT_INITIAL_MATRIX, &ptap->Rd));
1540:   PetscCall(MatTranspose(p->B, MAT_INITIAL_MATRIX, &ptap->Ro));

1542:   /* (1) compute symbolic A_loc */
1543:   PetscCall(MatMPIAIJGetLocalMat(A, MAT_INITIAL_MATRIX, &ptap->A_loc));

1545:   /* (2-1) compute symbolic C_oth = Ro*A_loc  */
1546:   PetscCall(MatGetOptionsPrefix(A, &prefix));
1547:   PetscCall(MatSetOptionsPrefix(ptap->Ro, prefix));
1548:   PetscCall(MatAppendOptionsPrefix(ptap->Ro, "inner_offdiag_"));
1549:   PetscCall(MatCreate(PETSC_COMM_SELF, &ptap->C_oth));
1550:   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(ptap->Ro, ptap->A_loc, fill, ptap->C_oth));

1552:   /* (3) send coj of C_oth to other processors  */
1553:   /* determine row ownership */
1554:   PetscCall(PetscLayoutCreate(comm, &rowmap));
1555:   rowmap->n  = pn;
1556:   rowmap->bs = 1;
1557:   PetscCall(PetscLayoutSetUp(rowmap));
1558:   owners = rowmap->range;

1560:   /* determine the number of messages to send, their lengths */
1561:   PetscCall(PetscMalloc4(size, &len_s, size, &len_si, size, &sstatus, size + 1, &owners_co));
1562:   PetscCall(PetscArrayzero(len_s, size));
1563:   PetscCall(PetscArrayzero(len_si, size));

1565:   c_oth = (Mat_SeqAIJ *)ptap->C_oth->data;
1566:   coi   = c_oth->i;
1567:   coj   = c_oth->j;
1568:   con   = ptap->C_oth->rmap->n;
1569:   proc  = 0;
1570:   for (i = 0; i < con; i++) {
1571:     while (prmap[i] >= owners[proc + 1]) proc++;
1572:     len_si[proc]++;                     /* num of rows in Co(=Pt*A) to be sent to [proc] */
1573:     len_s[proc] += coi[i + 1] - coi[i]; /* num of nonzeros in Co to be sent to [proc] */
1574:   }

1576:   len          = 0; /* max length of buf_si[], see (4) */
1577:   owners_co[0] = 0;
1578:   nsend        = 0;
1579:   for (proc = 0; proc < size; proc++) {
1580:     owners_co[proc + 1] = owners_co[proc] + len_si[proc];
1581:     if (len_s[proc]) {
1582:       nsend++;
1583:       len_si[proc] = 2 * (len_si[proc] + 1); /* length of buf_si to be sent to [proc] */
1584:       len += len_si[proc];
1585:     }
1586:   }

1588:   /* determine the number and length of messages to receive for coi and coj  */
1589:   PetscCall(PetscGatherNumberOfMessages(comm, NULL, len_s, &nrecv));
1590:   PetscCall(PetscGatherMessageLengths2(comm, nsend, nrecv, len_s, len_si, &id_r, &len_r, &len_ri));

1592:   /* post the Irecv and Isend of coj */
1593:   PetscCall(PetscCommGetNewTag(comm, &tagj));
1594:   PetscCall(PetscPostIrecvInt(comm, tagj, nrecv, id_r, len_r, &buf_rj, &rwaits));
1595:   PetscCall(PetscMalloc1(nsend, &swaits));
1596:   for (proc = 0, k = 0; proc < size; proc++) {
1597:     if (!len_s[proc]) continue;
1598:     i = owners_co[proc];
1599:     PetscCallMPI(MPIU_Isend(coj + coi[i], len_s[proc], MPIU_INT, proc, tagj, comm, swaits + k));
1600:     k++;
1601:   }

1603:   /* (2-2) compute symbolic C_loc = Rd*A_loc */
1604:   PetscCall(MatSetOptionsPrefix(ptap->Rd, prefix));
1605:   PetscCall(MatAppendOptionsPrefix(ptap->Rd, "inner_diag_"));
1606:   PetscCall(MatCreate(PETSC_COMM_SELF, &ptap->C_loc));
1607:   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(ptap->Rd, ptap->A_loc, fill, ptap->C_loc));
1608:   c_loc = (Mat_SeqAIJ *)ptap->C_loc->data;

1610:   /* receives coj are complete */
1611:   for (i = 0; i < nrecv; i++) PetscCallMPI(MPI_Waitany(nrecv, rwaits, &icompleted, &rstatus));
1612:   PetscCall(PetscFree(rwaits));
1613:   if (nsend) PetscCallMPI(MPI_Waitall(nsend, swaits, sstatus));

1615:   /* add received column indices into ta to update Crmax */
1616:   a_loc = (Mat_SeqAIJ *)ptap->A_loc->data;

1618:   /* create and initialize a linked list */
1619:   PetscCall(PetscHMapICreateWithSize(an, &ta)); /* for compute Crmax */
1620:   MatRowMergeMax_SeqAIJ(a_loc, ptap->A_loc->rmap->N, ta);

1622:   for (k = 0; k < nrecv; k++) { /* k-th received message */
1623:     Jptr = buf_rj[k];
1624:     for (j = 0; j < len_r[k]; j++) PetscCall(PetscHMapISet(ta, *(Jptr + j) + 1, 1));
1625:   }
1626:   PetscCall(PetscHMapIGetSize(ta, &Crmax));
1627:   PetscCall(PetscHMapIDestroy(&ta));

1629:   /* (4) send and recv coi */
1630:   PetscCall(PetscCommGetNewTag(comm, &tagi));
1631:   PetscCall(PetscPostIrecvInt(comm, tagi, nrecv, id_r, len_ri, &buf_ri, &rwaits));
1632:   PetscCall(PetscMalloc1(len, &buf_s));
1633:   buf_si = buf_s; /* points to the beginning of k-th msg to be sent */
1634:   for (proc = 0, k = 0; proc < size; proc++) {
1635:     if (!len_s[proc]) continue;
1636:     /* form outgoing message for i-structure:
1637:          buf_si[0]:                 nrows to be sent
1638:                [1:nrows]:           row index (global)
1639:                [nrows+1:2*nrows+1]: i-structure index
1640:     */
1641:     nrows       = len_si[proc] / 2 - 1; /* num of rows in Co to be sent to [proc] */
1642:     buf_si_i    = buf_si + nrows + 1;
1643:     buf_si[0]   = nrows;
1644:     buf_si_i[0] = 0;
1645:     nrows       = 0;
1646:     for (i = owners_co[proc]; i < owners_co[proc + 1]; i++) {
1647:       nzi                 = coi[i + 1] - coi[i];
1648:       buf_si_i[nrows + 1] = buf_si_i[nrows] + nzi;   /* i-structure */
1649:       buf_si[nrows + 1]   = prmap[i] - owners[proc]; /* local row index */
1650:       nrows++;
1651:     }
1652:     PetscCallMPI(MPIU_Isend(buf_si, len_si[proc], MPIU_INT, proc, tagi, comm, swaits + k));
1653:     k++;
1654:     buf_si += len_si[proc];
1655:   }
1656:   for (i = 0; i < nrecv; i++) PetscCallMPI(MPI_Waitany(nrecv, rwaits, &icompleted, &rstatus));
1657:   PetscCall(PetscFree(rwaits));
1658:   if (nsend) PetscCallMPI(MPI_Waitall(nsend, swaits, sstatus));

1660:   PetscCall(PetscFree4(len_s, len_si, sstatus, owners_co));
1661:   PetscCall(PetscFree(len_ri));
1662:   PetscCall(PetscFree(swaits));
1663:   PetscCall(PetscFree(buf_s));

1665:   /* (5) compute the local portion of C      */
1666:   /* set initial free space to be Crmax, sufficient for holding nonzeros in each row of C */
1667:   PetscCall(PetscFreeSpaceGet(Crmax, &free_space));
1668:   current_space = free_space;

1670:   PetscCall(PetscMalloc3(nrecv, &buf_ri_k, nrecv, &nextrow, nrecv, &nextci));
1671:   for (k = 0; k < nrecv; k++) {
1672:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
1673:     nrows       = *buf_ri_k[k];
1674:     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
1675:     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
1676:   }

1678:   MatPreallocateBegin(comm, pn, an, dnz, onz);
1679:   PetscCall(PetscLLCondensedCreate(Crmax, aN, &lnk, &lnkbt));
1680:   for (i = 0; i < pn; i++) { /* for each local row of C */
1681:     /* add C_loc into C */
1682:     nzi  = c_loc->i[i + 1] - c_loc->i[i];
1683:     Jptr = c_loc->j + c_loc->i[i];
1684:     PetscCall(PetscLLCondensedAddSorted(nzi, Jptr, lnk, lnkbt));

1686:     /* add received col data into lnk */
1687:     for (k = 0; k < nrecv; k++) { /* k-th received message */
1688:       if (i == *nextrow[k]) {     /* i-th row */
1689:         nzi  = *(nextci[k] + 1) - *nextci[k];
1690:         Jptr = buf_rj[k] + *nextci[k];
1691:         PetscCall(PetscLLCondensedAddSorted(nzi, Jptr, lnk, lnkbt));
1692:         nextrow[k]++;
1693:         nextci[k]++;
1694:       }
1695:     }

1697:     /* add missing diagonal entry */
1698:     if (C->force_diagonals) {
1699:       k = i + owners[rank]; /* column index */
1700:       PetscCall(PetscLLCondensedAddSorted(1, &k, lnk, lnkbt));
1701:     }

1703:     nzi = lnk[0];

1705:     /* copy data into free space, then initialize lnk */
1706:     PetscCall(PetscLLCondensedClean(aN, nzi, current_space->array, lnk, lnkbt));
1707:     PetscCall(MatPreallocateSet(i + owners[rank], nzi, current_space->array, dnz, onz));
1708:   }
1709:   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));
1710:   PetscCall(PetscLLDestroy(lnk, lnkbt));
1711:   PetscCall(PetscFreeSpaceDestroy(free_space));

1713:   /* local sizes and preallocation */
1714:   PetscCall(MatSetSizes(C, pn, an, PETSC_DETERMINE, PETSC_DETERMINE));
1715:   PetscCall(PetscLayoutSetBlockSize(C->rmap, P->cmap->bs));
1716:   PetscCall(PetscLayoutSetBlockSize(C->cmap, A->cmap->bs));
1717:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
1718:   MatPreallocateEnd(dnz, onz);

1720:   /* add C_loc and C_oth to C */
1721:   PetscCall(MatGetOwnershipRange(C, &rstart, NULL));
1722:   for (i = 0; i < pn; i++) {
1723:     ncols = c_loc->i[i + 1] - c_loc->i[i];
1724:     cols  = c_loc->j + c_loc->i[i];
1725:     row   = rstart + i;
1726:     PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, ncols, (const PetscInt *)cols, NULL, INSERT_VALUES));

1728:     if (C->force_diagonals) PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, 1, (const PetscInt *)&row, NULL, INSERT_VALUES));
1729:   }
1730:   for (i = 0; i < con; i++) {
1731:     ncols = c_oth->i[i + 1] - c_oth->i[i];
1732:     cols  = c_oth->j + c_oth->i[i];
1733:     row   = prmap[i];
1734:     PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, ncols, (const PetscInt *)cols, NULL, INSERT_VALUES));
1735:   }
1736:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1737:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1738:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));

1740:   /* members in merge */
1741:   PetscCall(PetscFree(id_r));
1742:   PetscCall(PetscFree(len_r));
1743:   PetscCall(PetscFree(buf_ri[0]));
1744:   PetscCall(PetscFree(buf_ri));
1745:   PetscCall(PetscFree(buf_rj[0]));
1746:   PetscCall(PetscFree(buf_rj));
1747:   PetscCall(PetscLayoutDestroy(&rowmap));

1749:   /* attach the supporting struct to C for reuse */
1750:   C->product->data    = ptap;
1751:   C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
1752:   PetscFunctionReturn(PETSC_SUCCESS);
1753: }

1755: PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat P, Mat A, Mat C)
1756: {
1757:   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data;
1758:   Mat_SeqAIJ          *c_seq;
1759:   MatProductCtx_APMPI *ptap;
1760:   Mat                  A_loc, C_loc, C_oth;
1761:   PetscInt             i, rstart, rend, cm, ncols, row;
1762:   const PetscInt      *cols;
1763:   const PetscScalar   *vals;

1765:   PetscFunctionBegin;
1766:   MatCheckProduct(C, 3);
1767:   ptap = (MatProductCtx_APMPI *)C->product->data;
1768:   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
1769:   PetscCheck(ptap->A_loc, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");
1770:   PetscCall(MatZeroEntries(C));

1772:   /* These matrices are obtained in MatTransposeMatMultSymbolic() */
1773:   /* 1) get R = Pd^T, Ro = Po^T */
1774:   PetscCall(MatTransposeSetPrecursor(p->A, ptap->Rd));
1775:   PetscCall(MatTranspose(p->A, MAT_REUSE_MATRIX, &ptap->Rd));
1776:   PetscCall(MatTransposeSetPrecursor(p->B, ptap->Ro));
1777:   PetscCall(MatTranspose(p->B, MAT_REUSE_MATRIX, &ptap->Ro));

1779:   /* 2) compute numeric A_loc */
1780:   PetscCall(MatMPIAIJGetLocalMat(A, MAT_REUSE_MATRIX, &ptap->A_loc));

1782:   /* 3) C_loc = Rd*A_loc, C_oth = Ro*A_loc */
1783:   A_loc = ptap->A_loc;
1784:   PetscCall(ptap->C_loc->ops->matmultnumeric(ptap->Rd, A_loc, ptap->C_loc));
1785:   PetscCall(ptap->C_oth->ops->matmultnumeric(ptap->Ro, A_loc, ptap->C_oth));
1786:   C_loc = ptap->C_loc;
1787:   C_oth = ptap->C_oth;

1789:   /* add C_loc and C_oth to C */
1790:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));

1792:   /* C_loc -> C */
1793:   cm    = C_loc->rmap->N;
1794:   c_seq = (Mat_SeqAIJ *)C_loc->data;
1795:   cols  = c_seq->j;
1796:   vals  = c_seq->a;
1797:   for (i = 0; i < cm; i++) {
1798:     ncols = c_seq->i[i + 1] - c_seq->i[i];
1799:     row   = rstart + i;
1800:     PetscCall(MatSetValues(C, 1, &row, ncols, cols, vals, ADD_VALUES));
1801:     cols += ncols;
1802:     vals += ncols;
1803:   }

1805:   /* Co -> C, off-processor part */
1806:   cm    = C_oth->rmap->N;
1807:   c_seq = (Mat_SeqAIJ *)C_oth->data;
1808:   cols  = c_seq->j;
1809:   vals  = c_seq->a;
1810:   for (i = 0; i < cm; i++) {
1811:     ncols = c_seq->i[i + 1] - c_seq->i[i];
1812:     row   = p->garray[i];
1813:     PetscCall(MatSetValues(C, 1, &row, ncols, cols, vals, ADD_VALUES));
1814:     cols += ncols;
1815:     vals += ncols;
1816:   }
1817:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1818:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1819:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
1820:   PetscFunctionReturn(PETSC_SUCCESS);
1821: }

1823: PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ(Mat P, Mat A, Mat C)
1824: {
1825:   MatMergeSeqsToMPI   *merge;
1826:   Mat_MPIAIJ          *p  = (Mat_MPIAIJ *)P->data;
1827:   Mat_SeqAIJ          *pd = (Mat_SeqAIJ *)p->A->data, *po = (Mat_SeqAIJ *)p->B->data;
1828:   MatProductCtx_APMPI *ap;
1829:   PetscInt            *adj;
1830:   PetscInt             i, j, k, anz, pnz, row, *cj, nexta;
1831:   MatScalar           *ada, *ca, valtmp;
1832:   PetscInt             am = A->rmap->n, cm = C->rmap->n, pon = p->B->cmap->n;
1833:   MPI_Comm             comm;
1834:   PetscMPIInt          size, rank, taga, *len_s, proc;
1835:   PetscInt            *owners, nrows, **buf_ri_k, **nextrow, **nextci;
1836:   PetscInt           **buf_ri, **buf_rj;
1837:   PetscInt             cnz = 0, *bj_i, *bi, *bj, bnz, nextcj; /* bi,bj,ba: local array of C(mpi mat) */
1838:   MPI_Request         *s_waits, *r_waits;
1839:   MPI_Status          *status;
1840:   MatScalar          **abuf_r, *ba_i, *pA, *coa, *ba;
1841:   const PetscScalar   *dummy;
1842:   PetscInt            *ai, *aj, *coi, *coj, *poJ, *pdJ;
1843:   Mat                  A_loc;
1844:   Mat_SeqAIJ          *a_loc;

1846:   PetscFunctionBegin;
1847:   MatCheckProduct(C, 3);
1848:   ap = (MatProductCtx_APMPI *)C->product->data;
1849:   PetscCheck(ap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be computed. Missing data");
1850:   PetscCheck(ap->A_loc, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");
1851:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
1852:   PetscCallMPI(MPI_Comm_size(comm, &size));
1853:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

1855:   merge = ap->merge;

1857:   /* 2) compute numeric C_seq = P_loc^T*A_loc */
1858:   /* get data from symbolic products */
1859:   coi = merge->coi;
1860:   coj = merge->coj;
1861:   PetscCall(PetscCalloc1(coi[pon], &coa));
1862:   bi     = merge->bi;
1863:   bj     = merge->bj;
1864:   owners = merge->rowmap->range;
1865:   PetscCall(PetscCalloc1(bi[cm], &ba));

1867:   /* get A_loc by taking all local rows of A */
1868:   A_loc = ap->A_loc;
1869:   PetscCall(MatMPIAIJGetLocalMat(A, MAT_REUSE_MATRIX, &A_loc));
1870:   a_loc = (Mat_SeqAIJ *)A_loc->data;
1871:   ai    = a_loc->i;
1872:   aj    = a_loc->j;

1874:   /* trigger copy to CPU */
1875:   PetscCall(MatSeqAIJGetArrayRead(p->A, &dummy));
1876:   PetscCall(MatSeqAIJRestoreArrayRead(p->A, &dummy));
1877:   PetscCall(MatSeqAIJGetArrayRead(p->B, &dummy));
1878:   PetscCall(MatSeqAIJRestoreArrayRead(p->B, &dummy));
1879:   for (i = 0; i < am; i++) {
1880:     anz = ai[i + 1] - ai[i];
1881:     adj = aj + ai[i];
1882:     ada = a_loc->a + ai[i];

1884:     /* 2-b) Compute Cseq = P_loc[i,:]^T*A[i,:] using outer product */
1885:     /* put the value into Co=(p->B)^T*A (off-diagonal part, send to others) */
1886:     pnz = po->i[i + 1] - po->i[i];
1887:     poJ = po->j + po->i[i];
1888:     pA  = po->a + po->i[i];
1889:     for (j = 0; j < pnz; j++) {
1890:       row = poJ[j];
1891:       cj  = coj + coi[row];
1892:       ca  = coa + coi[row];
1893:       /* perform sparse axpy */
1894:       nexta  = 0;
1895:       valtmp = pA[j];
1896:       for (k = 0; nexta < anz; k++) {
1897:         if (cj[k] == adj[nexta]) {
1898:           ca[k] += valtmp * ada[nexta];
1899:           nexta++;
1900:         }
1901:       }
1902:       PetscCall(PetscLogFlops(2.0 * anz));
1903:     }

1905:     /* put the value into Cd (diagonal part) */
1906:     pnz = pd->i[i + 1] - pd->i[i];
1907:     pdJ = pd->j + pd->i[i];
1908:     pA  = pd->a + pd->i[i];
1909:     for (j = 0; j < pnz; j++) {
1910:       row = pdJ[j];
1911:       cj  = bj + bi[row];
1912:       ca  = ba + bi[row];
1913:       /* perform sparse axpy */
1914:       nexta  = 0;
1915:       valtmp = pA[j];
1916:       for (k = 0; nexta < anz; k++) {
1917:         if (cj[k] == adj[nexta]) {
1918:           ca[k] += valtmp * ada[nexta];
1919:           nexta++;
1920:         }
1921:       }
1922:       PetscCall(PetscLogFlops(2.0 * anz));
1923:     }
1924:   }

1926:   /* 3) send and recv matrix values coa */
1927:   buf_ri = merge->buf_ri;
1928:   buf_rj = merge->buf_rj;
1929:   len_s  = merge->len_s;
1930:   PetscCall(PetscCommGetNewTag(comm, &taga));
1931:   PetscCall(PetscPostIrecvScalar(comm, taga, merge->nrecv, merge->id_r, merge->len_r, &abuf_r, &r_waits));

1933:   PetscCall(PetscMalloc2(merge->nsend, &s_waits, size, &status));
1934:   for (proc = 0, k = 0; proc < size; proc++) {
1935:     if (!len_s[proc]) continue;
1936:     i = merge->owners_co[proc];
1937:     PetscCallMPI(MPIU_Isend(coa + coi[i], len_s[proc], MPIU_MATSCALAR, proc, taga, comm, s_waits + k));
1938:     k++;
1939:   }
1940:   if (merge->nrecv) PetscCallMPI(MPI_Waitall(merge->nrecv, r_waits, status));
1941:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, s_waits, status));

1943:   PetscCall(PetscFree2(s_waits, status));
1944:   PetscCall(PetscFree(r_waits));
1945:   PetscCall(PetscFree(coa));

1947:   /* 4) insert local Cseq and received values into Cmpi */
1948:   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextci));
1949:   for (k = 0; k < merge->nrecv; k++) {
1950:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
1951:     nrows       = *buf_ri_k[k];
1952:     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
1953:     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
1954:   }

1956:   for (i = 0; i < cm; i++) {
1957:     row  = owners[rank] + i; /* global row index of C_seq */
1958:     bj_i = bj + bi[i];       /* col indices of the i-th row of C */
1959:     ba_i = ba + bi[i];
1960:     bnz  = bi[i + 1] - bi[i];
1961:     /* add received vals into ba */
1962:     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
1963:       /* i-th row */
1964:       if (i == *nextrow[k]) {
1965:         cnz    = *(nextci[k] + 1) - *nextci[k];
1966:         cj     = buf_rj[k] + *nextci[k];
1967:         ca     = abuf_r[k] + *nextci[k];
1968:         nextcj = 0;
1969:         for (j = 0; nextcj < cnz; j++) {
1970:           if (bj_i[j] == cj[nextcj]) { /* bcol == ccol */
1971:             ba_i[j] += ca[nextcj++];
1972:           }
1973:         }
1974:         nextrow[k]++;
1975:         nextci[k]++;
1976:         PetscCall(PetscLogFlops(2.0 * cnz));
1977:       }
1978:     }
1979:     PetscCall(MatSetValues(C, 1, &row, bnz, bj_i, ba_i, INSERT_VALUES));
1980:   }
1981:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1982:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));

1984:   PetscCall(PetscFree(ba));
1985:   PetscCall(PetscFree(abuf_r[0]));
1986:   PetscCall(PetscFree(abuf_r));
1987:   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));
1988:   PetscFunctionReturn(PETSC_SUCCESS);
1989: }

1991: PetscErrorCode MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ(Mat P, Mat A, PetscReal fill, Mat C)
1992: {
1993:   Mat                  A_loc;
1994:   MatProductCtx_APMPI *ap;
1995:   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
1996:   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data, *a = (Mat_MPIAIJ *)A->data;
1997:   PetscInt            *pdti, *pdtj, *poti, *potj, *ptJ;
1998:   PetscInt             nnz;
1999:   PetscInt            *lnk, *owners_co, *coi, *coj, i, k, pnz, row;
2000:   PetscInt             am = A->rmap->n, pn = P->cmap->n;
2001:   MPI_Comm             comm;
2002:   PetscMPIInt          size, rank, tagi, tagj, *len_si, *len_s, *len_ri, proc;
2003:   PetscInt           **buf_rj, **buf_ri, **buf_ri_k;
2004:   PetscInt             len, *dnz, *onz, *owners;
2005:   PetscInt             nzi, *bi, *bj;
2006:   PetscInt             nrows, *buf_s, *buf_si, *buf_si_i, **nextrow, **nextci;
2007:   MPI_Request         *swaits, *rwaits;
2008:   MPI_Status          *sstatus, rstatus;
2009:   MatMergeSeqsToMPI   *merge;
2010:   PetscInt            *ai, *aj, *Jptr, anz, *prmap = p->garray, pon, nspacedouble = 0, j;
2011:   PetscReal            afill  = 1.0, afill_tmp;
2012:   PetscInt             rstart = P->cmap->rstart, rmax, Armax;
2013:   Mat_SeqAIJ          *a_loc;
2014:   PetscHMapI           ta;
2015:   MatType              mtype;

2017:   PetscFunctionBegin;
2018:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
2019:   /* check if matrix local sizes are compatible */
2020:   PetscCheck(A->rmap->rstart == P->rmap->rstart && A->rmap->rend == P->rmap->rend, comm, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A (%" PetscInt_FMT ", %" PetscInt_FMT ") != P (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->rstart,
2021:              A->rmap->rend, P->rmap->rstart, P->rmap->rend);

2023:   PetscCallMPI(MPI_Comm_size(comm, &size));
2024:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

2026:   /* create struct MatProductCtx_APMPI and attached it to C later */
2027:   PetscCall(PetscNew(&ap));

2029:   /* get A_loc by taking all local rows of A */
2030:   PetscCall(MatMPIAIJGetLocalMat_Private(A, MAT_INITIAL_MATRIX, C->structure_only, &A_loc));

2032:   ap->A_loc = A_loc;
2033:   a_loc     = (Mat_SeqAIJ *)A_loc->data;
2034:   ai        = a_loc->i;
2035:   aj        = a_loc->j;

2037:   /* determine symbolic Co=(p->B)^T*A - send to others */
2038:   PetscCall(MatGetSymbolicTranspose_SeqAIJ(p->A, &pdti, &pdtj));
2039:   PetscCall(MatGetSymbolicTranspose_SeqAIJ(p->B, &poti, &potj));
2040:   pon = p->B->cmap->n; /* total num of rows to be sent to other processors
2041:                          >= (num of nonzero rows of C_seq) - pn */
2042:   PetscCall(PetscMalloc1(pon + 1, &coi));
2043:   coi[0] = 0;

2045:   /* set initial free space to be fill*(nnz(p->B) + nnz(A)) */
2046:   nnz = PetscRealIntMultTruncate(fill, PetscIntSumTruncate(poti[pon], ai[am]));
2047:   PetscCall(PetscFreeSpaceGet(nnz, &free_space));
2048:   current_space = free_space;

2050:   /* create and initialize a linked list */
2051:   PetscCall(PetscHMapICreateWithSize(A->cmap->n + a->B->cmap->N, &ta));
2052:   MatRowMergeMax_SeqAIJ(a_loc, am, ta);
2053:   PetscCall(PetscHMapIGetSize(ta, &Armax));

2055:   PetscCall(PetscLLCondensedCreate_Scalable(Armax, &lnk));

2057:   for (i = 0; i < pon; i++) {
2058:     pnz = poti[i + 1] - poti[i];
2059:     ptJ = potj + poti[i];
2060:     for (j = 0; j < pnz; j++) {
2061:       row  = ptJ[j]; /* row of A_loc == col of Pot */
2062:       anz  = ai[row + 1] - ai[row];
2063:       Jptr = aj + ai[row];
2064:       /* add non-zero cols of AP into the sorted linked list lnk */
2065:       PetscCall(PetscLLCondensedAddSorted_Scalable(anz, Jptr, lnk));
2066:     }
2067:     nnz = lnk[0];

2069:     /* If free space is not available, double the total space in the list */
2070:     if (current_space->local_remaining < nnz) {
2071:       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(nnz, current_space->total_array_size), &current_space));
2072:       nspacedouble++;
2073:     }

2075:     /* Copy data into free space, and zero out denserows */
2076:     PetscCall(PetscLLCondensedClean_Scalable(nnz, current_space->array, lnk));

2078:     current_space->array += nnz;
2079:     current_space->local_used += nnz;
2080:     current_space->local_remaining -= nnz;

2082:     coi[i + 1] = coi[i] + nnz;
2083:   }

2085:   PetscCall(PetscMalloc1(coi[pon], &coj));
2086:   PetscCall(PetscFreeSpaceContiguous(&free_space, coj));
2087:   PetscCall(PetscLLCondensedDestroy_Scalable(lnk)); /* must destroy to get a new one for C */

2089:   afill_tmp = (PetscReal)coi[pon] / (poti[pon] + ai[am] + 1);
2090:   if (afill_tmp > afill) afill = afill_tmp;

2092:   /* send j-array (coj) of Co to other processors */
2093:   /* determine row ownership */
2094:   PetscCall(PetscNew(&merge));
2095:   PetscCall(PetscLayoutCreate(comm, &merge->rowmap));

2097:   merge->rowmap->n  = pn;
2098:   merge->rowmap->bs = 1;

2100:   PetscCall(PetscLayoutSetUp(merge->rowmap));
2101:   owners = merge->rowmap->range;

2103:   /* determine the number of messages to send, their lengths */
2104:   PetscCall(PetscCalloc1(size, &len_si));
2105:   PetscCall(PetscCalloc1(size, &merge->len_s));

2107:   len_s        = merge->len_s;
2108:   merge->nsend = 0;

2110:   PetscCall(PetscMalloc1(size + 1, &owners_co));

2112:   proc = 0;
2113:   for (i = 0; i < pon; i++) {
2114:     while (prmap[i] >= owners[proc + 1]) proc++;
2115:     len_si[proc]++; /* num of rows in Co to be sent to [proc] */
2116:     len_s[proc] += coi[i + 1] - coi[i];
2117:   }

2119:   len          = 0; /* max length of buf_si[] */
2120:   owners_co[0] = 0;
2121:   for (proc = 0; proc < size; proc++) {
2122:     owners_co[proc + 1] = owners_co[proc] + len_si[proc];
2123:     if (len_s[proc]) {
2124:       merge->nsend++;
2125:       len_si[proc] = 2 * (len_si[proc] + 1);
2126:       len += len_si[proc];
2127:     }
2128:   }

2130:   /* determine the number and length of messages to receive for coi and coj  */
2131:   PetscCall(PetscGatherNumberOfMessages(comm, NULL, len_s, &merge->nrecv));
2132:   PetscCall(PetscGatherMessageLengths2(comm, merge->nsend, merge->nrecv, len_s, len_si, &merge->id_r, &merge->len_r, &len_ri));

2134:   /* post the Irecv and Isend of coj */
2135:   PetscCall(PetscCommGetNewTag(comm, &tagj));
2136:   PetscCall(PetscPostIrecvInt(comm, tagj, merge->nrecv, merge->id_r, merge->len_r, &buf_rj, &rwaits));
2137:   PetscCall(PetscMalloc1(merge->nsend, &swaits));
2138:   for (proc = 0, k = 0; proc < size; proc++) {
2139:     if (!len_s[proc]) continue;
2140:     i = owners_co[proc];
2141:     PetscCallMPI(MPIU_Isend(coj + coi[i], len_s[proc], MPIU_INT, proc, tagj, comm, swaits + k));
2142:     k++;
2143:   }

2145:   /* receives and sends of coj are complete */
2146:   PetscCall(PetscMalloc1(size, &sstatus));
2147:   for (i = 0; i < merge->nrecv; i++) {
2148:     PETSC_UNUSED PetscMPIInt icompleted;
2149:     PetscCallMPI(MPI_Waitany(merge->nrecv, rwaits, &icompleted, &rstatus));
2150:   }
2151:   PetscCall(PetscFree(rwaits));
2152:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, swaits, sstatus));

2154:   /* add received column indices into table to update Armax */
2155:   /* Armax can be as large as aN if a P[row,:] is dense, see src/ksp/ksp/tutorials/ex56.c! */
2156:   for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
2157:     Jptr = buf_rj[k];
2158:     for (j = 0; j < merge->len_r[k]; j++) PetscCall(PetscHMapISet(ta, *(Jptr + j) + 1, 1));
2159:   }
2160:   PetscCall(PetscHMapIGetSize(ta, &Armax));

2162:   /* send and recv coi */
2163:   PetscCall(PetscCommGetNewTag(comm, &tagi));
2164:   PetscCall(PetscPostIrecvInt(comm, tagi, merge->nrecv, merge->id_r, len_ri, &buf_ri, &rwaits));
2165:   PetscCall(PetscMalloc1(len, &buf_s));
2166:   buf_si = buf_s; /* points to the beginning of k-th msg to be sent */
2167:   for (proc = 0, k = 0; proc < size; proc++) {
2168:     if (!len_s[proc]) continue;
2169:     /* form outgoing message for i-structure:
2170:          buf_si[0]:                 nrows to be sent
2171:                [1:nrows]:           row index (global)
2172:                [nrows+1:2*nrows+1]: i-structure index
2173:     */
2174:     nrows       = len_si[proc] / 2 - 1;
2175:     buf_si_i    = buf_si + nrows + 1;
2176:     buf_si[0]   = nrows;
2177:     buf_si_i[0] = 0;
2178:     nrows       = 0;
2179:     for (i = owners_co[proc]; i < owners_co[proc + 1]; i++) {
2180:       nzi                 = coi[i + 1] - coi[i];
2181:       buf_si_i[nrows + 1] = buf_si_i[nrows] + nzi;   /* i-structure */
2182:       buf_si[nrows + 1]   = prmap[i] - owners[proc]; /* local row index */
2183:       nrows++;
2184:     }
2185:     PetscCallMPI(MPIU_Isend(buf_si, len_si[proc], MPIU_INT, proc, tagi, comm, swaits + k));
2186:     k++;
2187:     buf_si += len_si[proc];
2188:   }
2189:   i = merge->nrecv;
2190:   while (i--) {
2191:     PETSC_UNUSED PetscMPIInt icompleted;
2192:     PetscCallMPI(MPI_Waitany(merge->nrecv, rwaits, &icompleted, &rstatus));
2193:   }
2194:   PetscCall(PetscFree(rwaits));
2195:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, swaits, sstatus));
2196:   PetscCall(PetscFree(len_si));
2197:   PetscCall(PetscFree(len_ri));
2198:   PetscCall(PetscFree(swaits));
2199:   PetscCall(PetscFree(sstatus));
2200:   PetscCall(PetscFree(buf_s));

2202:   /* compute the local portion of C (mpi mat) */
2203:   /* allocate bi array and free space for accumulating nonzero column info */
2204:   PetscCall(PetscMalloc1(pn + 1, &bi));
2205:   bi[0] = 0;

2207:   /* set initial free space to be fill*(nnz(P) + nnz(AP)) */
2208:   nnz = PetscRealIntMultTruncate(fill, PetscIntSumTruncate(pdti[pn], PetscIntSumTruncate(poti[pon], ai[am])));
2209:   PetscCall(PetscFreeSpaceGet(nnz, &free_space));
2210:   current_space = free_space;

2212:   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextci));
2213:   for (k = 0; k < merge->nrecv; k++) {
2214:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
2215:     nrows       = *buf_ri_k[k];
2216:     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
2217:     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th received i-structure  */
2218:   }

2220:   PetscCall(PetscLLCondensedCreate_Scalable(Armax, &lnk));
2221:   MatPreallocateBegin(comm, pn, A->cmap->n, dnz, onz);
2222:   rmax = 0;
2223:   for (i = 0; i < pn; i++) {
2224:     /* add pdt[i,:]*AP into lnk */
2225:     pnz = pdti[i + 1] - pdti[i];
2226:     ptJ = pdtj + pdti[i];
2227:     for (j = 0; j < pnz; j++) {
2228:       row  = ptJ[j]; /* row of AP == col of Pt */
2229:       anz  = ai[row + 1] - ai[row];
2230:       Jptr = aj + ai[row];
2231:       /* add non-zero cols of AP into the sorted linked list lnk */
2232:       PetscCall(PetscLLCondensedAddSorted_Scalable(anz, Jptr, lnk));
2233:     }

2235:     /* add received col data into lnk */
2236:     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
2237:       if (i == *nextrow[k]) {            /* i-th row */
2238:         nzi  = *(nextci[k] + 1) - *nextci[k];
2239:         Jptr = buf_rj[k] + *nextci[k];
2240:         PetscCall(PetscLLCondensedAddSorted_Scalable(nzi, Jptr, lnk));
2241:         nextrow[k]++;
2242:         nextci[k]++;
2243:       }
2244:     }

2246:     /* add missing diagonal entry */
2247:     if (C->force_diagonals) {
2248:       k = i + owners[rank]; /* column index */
2249:       PetscCall(PetscLLCondensedAddSorted_Scalable(1, &k, lnk));
2250:     }

2252:     nnz = lnk[0];

2254:     /* if free space is not available, make more free space */
2255:     if (current_space->local_remaining < nnz) {
2256:       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(nnz, current_space->total_array_size), &current_space));
2257:       nspacedouble++;
2258:     }
2259:     /* copy data into free space, then initialize lnk */
2260:     PetscCall(PetscLLCondensedClean_Scalable(nnz, current_space->array, lnk));
2261:     PetscCall(MatPreallocateSet(i + owners[rank], nnz, current_space->array, dnz, onz));

2263:     current_space->array += nnz;
2264:     current_space->local_used += nnz;
2265:     current_space->local_remaining -= nnz;

2267:     bi[i + 1] = bi[i] + nnz;
2268:     if (nnz > rmax) rmax = nnz;
2269:   }
2270:   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));

2272:   PetscCall(PetscMalloc1(bi[pn], &bj));
2273:   PetscCall(PetscFreeSpaceContiguous(&free_space, bj));
2274:   afill_tmp = (PetscReal)bi[pn] / (pdti[pn] + poti[pon] + ai[am] + 1);
2275:   if (afill_tmp > afill) afill = afill_tmp;
2276:   PetscCall(PetscLLCondensedDestroy_Scalable(lnk));
2277:   PetscCall(PetscHMapIDestroy(&ta));
2278:   PetscCall(MatRestoreSymbolicTranspose_SeqAIJ(p->A, &pdti, &pdtj));
2279:   PetscCall(MatRestoreSymbolicTranspose_SeqAIJ(p->B, &poti, &potj));

2281:   /* create symbolic parallel matrix C - why cannot be assembled in Numeric part   */
2282:   PetscCall(MatSetSizes(C, pn, A->cmap->n, PETSC_DETERMINE, PETSC_DETERMINE));
2283:   PetscCall(MatSetBlockSizes(C, P->cmap->bs, A->cmap->bs));
2284:   PetscCall(MatGetType(A, &mtype));
2285:   PetscCall(MatSetType(C, C->structure_only ? MATMPIAIJ : mtype));
2286:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
2287:   MatPreallocateEnd(dnz, onz);
2288:   PetscCall(MatSetBlockSize(C, 1));
2289:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
2290:   for (i = 0; i < pn; i++) {
2291:     row  = i + rstart;
2292:     nnz  = bi[i + 1] - bi[i];
2293:     Jptr = bj + bi[i];
2294:     PetscCall(MatSetValues(C, 1, &row, nnz, Jptr, NULL, INSERT_VALUES));
2295:   }
2296:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2297:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2298:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
2299:   merge->bi        = bi;
2300:   merge->bj        = bj;
2301:   merge->coi       = coi;
2302:   merge->coj       = coj;
2303:   merge->buf_ri    = buf_ri;
2304:   merge->buf_rj    = buf_rj;
2305:   merge->owners_co = owners_co;

2307:   /* attach the supporting struct to C for reuse */
2308:   C->product->data    = ap;
2309:   C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
2310:   ap->merge           = merge;

2312:   C->ops->mattransposemultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ;

2314:   if (PetscDefined(USE_INFO)) {
2315:     if (bi[pn] != 0) {
2316:       PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
2317:       PetscCall(PetscInfo(C, "Use MatTransposeMatMult(A,B,MatReuse,%g,&C) for best performance.\n", (double)afill));
2318:     } else PetscCall(PetscInfo(C, "Empty matrix product\n"));
2319:   }
2320:   PetscFunctionReturn(PETSC_SUCCESS);
2321: }

2323: static PetscErrorCode MatProductSymbolic_AtB_MPIAIJ_MPIAIJ(Mat C)
2324: {
2325:   Mat_Product *product = C->product;
2326:   Mat          A = product->A, B = product->B;
2327:   PetscReal    fill = product->fill;
2328:   PetscBool    flg;

2330:   PetscFunctionBegin;
2331:   /* scalable */
2332:   PetscCall(PetscStrcmp(product->alg, "scalable", &flg));
2333:   if (flg || C->structure_only) {
2334:     if (C->structure_only) PetscCall(MatProductSetAlgorithm(C, "scalable"));
2335:     PetscCall(MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ(A, B, fill, C));
2336:     goto next;
2337:   }

2339:   /* nonscalable */
2340:   PetscCall(PetscStrcmp(product->alg, "nonscalable", &flg));
2341:   if (flg) {
2342:     PetscCall(MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(A, B, fill, C));
2343:     goto next;
2344:   }

2346:   /* matmatmult */
2347:   PetscCall(PetscStrcmp(product->alg, "at*b", &flg));
2348:   if (flg) {
2349:     Mat                  At;
2350:     MatProductCtx_APMPI *ptap;

2352:     PetscCall(MatTranspose(A, MAT_INITIAL_MATRIX, &At));
2353:     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ(At, B, fill, C));
2354:     ptap = (MatProductCtx_APMPI *)C->product->data;
2355:     if (ptap) {
2356:       ptap->Pt            = At;
2357:       C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
2358:     }
2359:     C->ops->transposematmultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_matmatmult;
2360:     goto next;
2361:   }

2363:   /* backend general code */
2364:   PetscCall(PetscStrcmp(product->alg, "backend", &flg));
2365:   if (flg) {
2366:     PetscCall(MatProductSymbolic_MPIAIJBACKEND(C));
2367:     PetscFunctionReturn(PETSC_SUCCESS);
2368:   }

2370:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "MatProduct type is not supported");

2372: next:
2373:   C->ops->productnumeric = MatProductNumeric_AtB;
2374:   PetscFunctionReturn(PETSC_SUCCESS);
2375: }

2377: /* Set options for MatMatMultxxx_MPIAIJ_MPIAIJ */
2378: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_AB(Mat C)
2379: {
2380:   Mat_Product *product = C->product;
2381:   Mat          A = product->A, B = product->B;
2382: #if PetscDefined(HAVE_HYPRE)
2383:   const char *algTypes[5] = {"scalable", "nonscalable", "seqmpi", "backend", "hypre"};
2384:   PetscInt    nalg        = 5;
2385: #else
2386:   const char *algTypes[4] = {
2387:     "scalable",
2388:     "nonscalable",
2389:     "seqmpi",
2390:     "backend",
2391:   };
2392:   PetscInt nalg = 4;
2393: #endif
2394:   PetscInt  alg = 1; /* set nonscalable algorithm as default */
2395:   PetscBool flg;
2396:   MPI_Comm  comm;

2398:   PetscFunctionBegin;
2399:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));

2401:   /* Set "nonscalable" as default algorithm */
2402:   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2403:   if (flg) {
2404:     PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2406:     /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2407:     if (B->cmap->N > 100000) { /* may switch to scalable algorithm as default */
2408:       MatInfo   Ainfo, Binfo;
2409:       PetscInt  nz_local;
2410:       PetscBool alg_scalable = PETSC_FALSE;

2412:       PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2413:       PetscCall(MatGetInfo(B, MAT_LOCAL, &Binfo));
2414:       nz_local = (PetscInt)(Ainfo.nz_allocated + Binfo.nz_allocated);

2416:       if (B->cmap->N > product->fill * nz_local) alg_scalable = PETSC_TRUE;
2417:       PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));

2419:       if (alg_scalable) {
2420:         alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2421:         PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2422:         PetscCall(PetscInfo(B, "Use scalable algorithm, BN %" PetscInt_FMT ", fill*nz_allocated %g\n", B->cmap->N, (double)(product->fill * nz_local)));
2423:       }
2424:     }
2425:   }

2427:   /* Get runtime option */
2428:   if (product->api_user) {
2429:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatMatMult", "Mat");
2430:     PetscCall(PetscOptionsEList("-matmatmult_via", "Algorithmic approach", "MatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2431:     PetscOptionsEnd();
2432:   } else {
2433:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_AB", "Mat");
2434:     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2435:     PetscOptionsEnd();
2436:   }
2437:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2439:   C->ops->productsymbolic = MatProductSymbolic_AB_MPIAIJ_MPIAIJ;
2440:   PetscFunctionReturn(PETSC_SUCCESS);
2441: }

2443: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_ABt(Mat C)
2444: {
2445:   PetscFunctionBegin;
2446:   PetscCall(MatProductSetFromOptions_MPIAIJ_AB(C));
2447:   C->ops->productsymbolic = MatProductSymbolic_ABt_MPIAIJ_MPIAIJ;
2448:   PetscFunctionReturn(PETSC_SUCCESS);
2449: }

2451: /* Set options for MatTransposeMatMultXXX_MPIAIJ_MPIAIJ */
2452: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_AtB(Mat C)
2453: {
2454:   Mat_Product *product = C->product;
2455:   Mat          A = product->A, B = product->B;
2456:   const char  *algTypes[4] = {"scalable", "nonscalable", "at*b", "backend"};
2457:   PetscInt     nalg        = 4;
2458:   PetscInt     alg         = 1; /* set default algorithm  */
2459:   PetscBool    flg;
2460:   MPI_Comm     comm;

2462:   PetscFunctionBegin;
2463:   /* Check matrix local sizes */
2464:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
2465:   PetscCheck(A->rmap->rstart == B->rmap->rstart && A->rmap->rend == B->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A (%" PetscInt_FMT ", %" PetscInt_FMT ") != B (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2466:              A->rmap->rstart, A->rmap->rend, B->rmap->rstart, B->rmap->rend);

2468:   /* Set default algorithm */
2469:   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2470:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2472:   /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2473:   if (alg && B->cmap->N > 100000) { /* may switch to scalable algorithm as default */
2474:     MatInfo   Ainfo, Binfo;
2475:     PetscInt  nz_local;
2476:     PetscBool alg_scalable = PETSC_FALSE;

2478:     PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2479:     PetscCall(MatGetInfo(B, MAT_LOCAL, &Binfo));
2480:     nz_local = (PetscInt)(Ainfo.nz_allocated + Binfo.nz_allocated);

2482:     if (B->cmap->N > product->fill * nz_local) alg_scalable = PETSC_TRUE;
2483:     PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));

2485:     if (alg_scalable) {
2486:       alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2487:       PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2488:       PetscCall(PetscInfo(B, "Use scalable algorithm, BN %" PetscInt_FMT ", fill*nz_allocated %g\n", B->cmap->N, (double)(product->fill * nz_local)));
2489:     }
2490:   }

2492:   /* Get runtime option */
2493:   if (product->api_user) {
2494:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatTransposeMatMult", "Mat");
2495:     PetscCall(PetscOptionsEList("-mattransposematmult_via", "Algorithmic approach", "MatTransposeMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2496:     PetscOptionsEnd();
2497:   } else {
2498:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_AtB", "Mat");
2499:     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatTransposeMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2500:     PetscOptionsEnd();
2501:   }
2502:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2504:   C->ops->productsymbolic = MatProductSymbolic_AtB_MPIAIJ_MPIAIJ;
2505:   PetscFunctionReturn(PETSC_SUCCESS);
2506: }

2508: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_PtAP(Mat C)
2509: {
2510:   Mat_Product *product = C->product;
2511:   Mat          A = product->A, P = product->B;
2512:   MPI_Comm     comm;
2513:   PetscBool    flg;
2514:   PetscInt     alg = 1; /* set default algorithm */
2515: #if !PetscDefined(HAVE_HYPRE)
2516:   const char *algTypes[5] = {"scalable", "nonscalable", "allatonce", "allatonce_merged", "backend"};
2517:   PetscInt    nalg        = 5;
2518: #else
2519:   const char *algTypes[6] = {"scalable", "nonscalable", "allatonce", "allatonce_merged", "backend", "hypre"};
2520:   PetscInt    nalg        = 6;
2521: #endif
2522:   PetscInt pN = P->cmap->N;

2524:   PetscFunctionBegin;
2525:   /* Check matrix local sizes */
2526:   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
2527:   PetscCheck(A->rmap->rstart == P->rmap->rstart && A->rmap->rend == P->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, Arow (%" PetscInt_FMT ", %" PetscInt_FMT ") != Prow (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2528:              A->rmap->rstart, A->rmap->rend, P->rmap->rstart, P->rmap->rend);
2529:   PetscCheck(A->cmap->rstart == P->rmap->rstart && A->cmap->rend == P->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, Acol (%" PetscInt_FMT ", %" PetscInt_FMT ") != Prow (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2530:              A->cmap->rstart, A->cmap->rend, P->rmap->rstart, P->rmap->rend);

2532:   /* Set "nonscalable" as default algorithm */
2533:   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2534:   if (flg) {
2535:     PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2537:     /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2538:     if (pN > 100000) {
2539:       MatInfo   Ainfo, Pinfo;
2540:       PetscInt  nz_local;
2541:       PetscBool alg_scalable = PETSC_FALSE;

2543:       PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2544:       PetscCall(MatGetInfo(P, MAT_LOCAL, &Pinfo));
2545:       nz_local = (PetscInt)(Ainfo.nz_allocated + Pinfo.nz_allocated);

2547:       if (pN > product->fill * nz_local) alg_scalable = PETSC_TRUE;
2548:       PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));

2550:       if (alg_scalable) {
2551:         alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2552:         PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2553:       }
2554:     }
2555:   }

2557:   /* Get runtime option */
2558:   if (product->api_user) {
2559:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatPtAP", "Mat");
2560:     PetscCall(PetscOptionsEList("-matptap_via", "Algorithmic approach", "MatPtAP", algTypes, nalg, algTypes[alg], &alg, &flg));
2561:     PetscOptionsEnd();
2562:   } else {
2563:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_PtAP", "Mat");
2564:     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatPtAP", algTypes, nalg, algTypes[alg], &alg, &flg));
2565:     PetscOptionsEnd();
2566:   }
2567:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2569:   C->ops->productsymbolic = MatProductSymbolic_PtAP_MPIAIJ_MPIAIJ;
2570:   PetscFunctionReturn(PETSC_SUCCESS);
2571: }

2573: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_RARt(Mat C)
2574: {
2575:   Mat_Product *product = C->product;
2576:   Mat          A = product->A, R = product->B;

2578:   PetscFunctionBegin;
2579:   /* Check matrix local sizes */
2580:   PetscCheck(A->cmap->n == R->cmap->n && A->rmap->n == R->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A local (%" PetscInt_FMT ", %" PetscInt_FMT "), R local (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->n,
2581:              A->rmap->n, R->rmap->n, R->cmap->n);

2583:   C->ops->productsymbolic = MatProductSymbolic_RARt_MPIAIJ_MPIAIJ;
2584:   PetscFunctionReturn(PETSC_SUCCESS);
2585: }

2587: /*
2588:  Set options for ABC = A*B*C = A*(B*C); ABC's algorithm must be chosen from AB's algorithm
2589: */
2590: static PetscErrorCode MatProductSetFromOptions_MPIAIJ_ABC(Mat C)
2591: {
2592:   Mat_Product *product     = C->product;
2593:   PetscBool    flg         = PETSC_FALSE;
2594:   PetscInt     alg         = 1; /* default algorithm */
2595:   const char  *algTypes[3] = {"scalable", "nonscalable", "seqmpi"};
2596:   PetscInt     nalg        = 3;

2598:   PetscFunctionBegin;
2599:   /* Set default algorithm */
2600:   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2601:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2603:   /* Get runtime option */
2604:   if (product->api_user) {
2605:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatMatMatMult", "Mat");
2606:     PetscCall(PetscOptionsEList("-matmatmatmult_via", "Algorithmic approach", "MatMatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2607:     PetscOptionsEnd();
2608:   } else {
2609:     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_ABC", "Mat");
2610:     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatProduct_ABC", algTypes, nalg, algTypes[alg], &alg, &flg));
2611:     PetscOptionsEnd();
2612:   }
2613:   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));

2615:   C->ops->matmatmultsymbolic = MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ;
2616:   C->ops->productsymbolic    = MatProductSymbolic_ABC;
2617:   PetscFunctionReturn(PETSC_SUCCESS);
2618: }

2620: PETSC_INTERN PetscErrorCode MatProductSetFromOptions_MPIAIJ(Mat C)
2621: {
2622:   Mat_Product *product = C->product;

2624:   PetscFunctionBegin;
2625:   switch (product->type) {
2626:   case MATPRODUCT_AB:
2627:     PetscCall(MatProductSetFromOptions_MPIAIJ_AB(C));
2628:     break;
2629:   case MATPRODUCT_ABt:
2630:     PetscCall(MatProductSetFromOptions_MPIAIJ_ABt(C));
2631:     break;
2632:   case MATPRODUCT_AtB:
2633:     PetscCall(MatProductSetFromOptions_MPIAIJ_AtB(C));
2634:     break;
2635:   case MATPRODUCT_PtAP:
2636:     PetscCall(MatProductSetFromOptions_MPIAIJ_PtAP(C));
2637:     break;
2638:   case MATPRODUCT_RARt:
2639:     PetscCall(MatProductSetFromOptions_MPIAIJ_RARt(C));
2640:     break;
2641:   case MATPRODUCT_ABC:
2642:     PetscCall(MatProductSetFromOptions_MPIAIJ_ABC(C));
2643:     break;
2644:   default:
2645:     break;
2646:   }
2647:   PetscFunctionReturn(PETSC_SUCCESS);
2648: }