Actual source code: mpiaij.c

  1: #include <../src/mat/impls/aij/mpi/mpiaij.h>
  2: #include <petsc/private/vecimpl.h>
  3: #include <petsc/private/sfimpl.h>
  4: #include <petsc/private/isimpl.h>
  5: #include <petscblaslapack.h>
  6: #include <petscsf.h>
  7: #include <petsc/private/hashmapi.h>

  9: /* defines MatSetValues_MPI_Hash(), MatAssemblyBegin_MPI_Hash(), and MatAssemblyEnd_MPI_Hash() */
 10: #define TYPE AIJ
 11: #define TYPE_AIJ
 12: #include "../src/mat/impls/aij/mpi/mpihashmat.h"
 13: #undef TYPE
 14: #undef TYPE_AIJ

 16: static PetscErrorCode MatReset_MPIAIJ(Mat mat)
 17: {
 18:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

 20:   PetscFunctionBegin;
 21:   PetscCall(PetscLogObjectState((PetscObject)mat, "Rows=%" PetscInt_FMT ", Cols=%" PetscInt_FMT, mat->rmap->N, mat->cmap->N));
 22:   PetscCall(MatStashDestroy_Private(&mat->stash));
 23:   PetscCall(VecDestroy(&aij->diag));
 24:   PetscCall(MatDestroy(&aij->A));
 25:   PetscCall(MatDestroy(&aij->B));
 26: #if defined(PETSC_USE_CTABLE)
 27:   PetscCall(PetscHMapIDestroy(&aij->colmap));
 28: #else
 29:   PetscCall(PetscFree(aij->colmap));
 30: #endif
 31:   PetscCall(PetscFree(aij->garray));
 32:   PetscCall(VecDestroy(&aij->lvec));
 33:   PetscCall(VecScatterDestroy(&aij->Mvctx));
 34:   PetscCall(PetscFree2(aij->rowvalues, aij->rowindices));
 35:   PetscCall(PetscFree(aij->ld));
 36:   PetscFunctionReturn(PETSC_SUCCESS);
 37: }

 39: static PetscErrorCode MatResetHash_MPIAIJ(Mat mat)
 40: {
 41:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;
 42:   /* Save the nonzero states of the component matrices because those are what are used to determine
 43:     the nonzero state of mat */
 44:   PetscObjectState Astate = aij->A->nonzerostate, Bstate = aij->B->nonzerostate;

 46:   PetscFunctionBegin;
 47:   PetscCall(MatReset_MPIAIJ(mat));
 48:   PetscCall(MatSetUp_MPI_Hash(mat));
 49:   aij->A->nonzerostate = ++Astate, aij->B->nonzerostate = ++Bstate;
 50:   PetscFunctionReturn(PETSC_SUCCESS);
 51: }

 53: PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
 54: {
 55:   PetscFunctionBegin;
 56:   PetscCall(MatReset_MPIAIJ(mat));

 58:   PetscCall(PetscFree(mat->data));

 60:   /* may be created by MatCreateMPIAIJSumSeqAIJSymbolic */
 61:   PetscCall(PetscObjectCompose((PetscObject)mat, "MatMergeSeqsToMPI", NULL));

 63:   PetscCall(PetscObjectChangeTypeName((PetscObject)mat, NULL));
 64:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatStoreValues_C", NULL));
 65:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatRetrieveValues_C", NULL));
 66:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatIsTranspose_C", NULL));
 67:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatMPIAIJSetPreallocation_C", NULL));
 68:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatResetPreallocation_C", NULL));
 69:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatResetHash_C", NULL));
 70:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatMPIAIJSetPreallocationCSR_C", NULL));
 71:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatDiagonalScaleLocal_C", NULL));
 72:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpibaij_C", NULL));
 73:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpisbaij_C", NULL));
 74: #if defined(PETSC_HAVE_CUDA)
 75:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijcusparse_C", NULL));
 76: #endif
 77: #if defined(PETSC_HAVE_HIP)
 78:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijhipsparse_C", NULL));
 79: #endif
 80: #if defined(PETSC_HAVE_KOKKOS_KERNELS)
 81:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijkokkos_C", NULL));
 82: #endif
 83:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpidense_C", NULL));
 84: #if defined(PETSC_HAVE_ELEMENTAL)
 85:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_elemental_C", NULL));
 86: #endif
 87: #if defined(PETSC_HAVE_SCALAPACK)
 88:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_scalapack_C", NULL));
 89: #endif
 90: #if defined(PETSC_HAVE_HYPRE)
 91:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_hypre_C", NULL));
 92:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_transpose_mpiaij_mpiaij_C", NULL));
 93: #endif
 94:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_is_C", NULL));
 95:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_is_mpiaij_C", NULL));
 96:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_mpiaij_mpiaij_C", NULL));
 97:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatMPIAIJSetUseScalableIncreaseOverlap_C", NULL));
 98:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijperm_C", NULL));
 99:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijsell_C", NULL));
100: #if defined(PETSC_HAVE_MKL_SPARSE)
101:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijmkl_C", NULL));
102: #endif
103:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpiaijcrl_C", NULL));
104:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_is_C", NULL));
105:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConvert_mpiaij_mpisell_C", NULL));
106:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatSetPreallocationCOO_C", NULL));
107:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatSetValuesCOO_C", NULL));
108:   PetscFunctionReturn(PETSC_SUCCESS);
109: }

111: static PetscErrorCode MatGetRowIJ_MPIAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *m, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
112: {
113:   Mat B;

115:   PetscFunctionBegin;
116:   PetscCall(MatMPIAIJGetLocalMat(A, MAT_INITIAL_MATRIX, &B));
117:   PetscCall(PetscObjectCompose((PetscObject)A, "MatGetRowIJ_MPIAIJ", (PetscObject)B));
118:   PetscCall(MatGetRowIJ(B, oshift, symmetric, inodecompressed, m, ia, ja, done));
119:   PetscCall(MatDestroy(&B));
120:   PetscFunctionReturn(PETSC_SUCCESS);
121: }

123: static PetscErrorCode MatRestoreRowIJ_MPIAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *m, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
124: {
125:   Mat B;

127:   PetscFunctionBegin;
128:   PetscCall(PetscObjectQuery((PetscObject)A, "MatGetRowIJ_MPIAIJ", (PetscObject *)&B));
129:   PetscCall(MatRestoreRowIJ(B, oshift, symmetric, inodecompressed, m, ia, ja, done));
130:   PetscCall(PetscObjectCompose((PetscObject)A, "MatGetRowIJ_MPIAIJ", NULL));
131:   PetscFunctionReturn(PETSC_SUCCESS);
132: }

134: /*MC
135:    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.

137:    This matrix type is identical to` MATSEQAIJ` when constructed with a single process communicator,
138:    and `MATMPIAIJ` otherwise.  As a result, for single process communicators,
139:   `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
140:   for communicators controlling multiple processes.  It is recommended that you call both of
141:   the above preallocation routines for simplicity.

143:    Options Database Key:
144: . -mat_type aij - sets the matrix type to `MATAIJ` during a call to `MatSetFromOptions()`

146:   Developer Note:
147:   Level: beginner

149:     Subclasses include `MATAIJCUSPARSE`, `MATAIJPERM`, `MATAIJSELL`, `MATAIJMKL`, `MATAIJCRL`, `MATAIJKOKKOS`,and also automatically switches over to use inodes when
150:    enough exist.

152: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MATSEQAIJ`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MATMPIAIJ`
153: M*/

155: /*MC
156:    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.

158:    This matrix type is identical to `MATSEQAIJCRL` when constructed with a single process communicator,
159:    and `MATMPIAIJCRL` otherwise.  As a result, for single process communicators,
160:    `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
161:   for communicators controlling multiple processes.  It is recommended that you call both of
162:   the above preallocation routines for simplicity.

164:    Options Database Key:
165: . -mat_type aijcrl - sets the matrix type to `MATMPIAIJCRL` during a call to `MatSetFromOptions()`

167:   Level: beginner

169: .seealso: [](ch_matrices), `Mat`, `MatCreateMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`
170: M*/

172: static PetscErrorCode MatBindToCPU_MPIAIJ(Mat A, PetscBool flg)
173: {
174:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

176:   PetscFunctionBegin;
177: #if defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP) || defined(PETSC_HAVE_VIENNACL)
178:   A->boundtocpu = flg;
179: #endif
180:   if (a->A) PetscCall(MatBindToCPU(a->A, flg));
181:   if (a->B) PetscCall(MatBindToCPU(a->B, flg));

183:   /* In addition to binding the diagonal and off-diagonal matrices, bind the local vectors used for matrix-vector products.
184:    * This maybe seems a little odd for a MatBindToCPU() call to do, but it makes no sense for the binding of these vectors
185:    * to differ from the parent matrix. */
186:   if (a->lvec) PetscCall(VecBindToCPU(a->lvec, flg));
187:   if (a->diag) PetscCall(VecBindToCPU(a->diag, flg));
188:   PetscFunctionReturn(PETSC_SUCCESS);
189: }

191: static PetscErrorCode MatSetBlockSizes_MPIAIJ(Mat M, PetscInt rbs, PetscInt cbs)
192: {
193:   Mat_MPIAIJ *mat = (Mat_MPIAIJ *)M->data;

195:   PetscFunctionBegin;
196:   if (mat->A) {
197:     PetscCall(MatSetBlockSizes(mat->A, rbs, cbs));
198:     PetscCall(MatSetBlockSizes(mat->B, rbs, 1));
199:   }
200:   PetscFunctionReturn(PETSC_SUCCESS);
201: }

203: static PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M, IS *keptrows)
204: {
205:   Mat_MPIAIJ      *mat = (Mat_MPIAIJ *)M->data;
206:   Mat_SeqAIJ      *a   = (Mat_SeqAIJ *)mat->A->data;
207:   Mat_SeqAIJ      *b   = (Mat_SeqAIJ *)mat->B->data;
208:   const PetscInt  *ia, *ib;
209:   const MatScalar *aa, *bb, *aav, *bav;
210:   PetscInt         na, nb, i, j, *rows, cnt = 0, n0rows;
211:   PetscInt         m = M->rmap->n, rstart = M->rmap->rstart;

213:   PetscFunctionBegin;
214:   *keptrows = NULL;

216:   ia = a->i;
217:   ib = b->i;
218:   PetscCall(MatSeqAIJGetArrayRead(mat->A, &aav));
219:   PetscCall(MatSeqAIJGetArrayRead(mat->B, &bav));
220:   for (i = 0; i < m; i++) {
221:     na = ia[i + 1] - ia[i];
222:     nb = ib[i + 1] - ib[i];
223:     if (!na && !nb) {
224:       cnt++;
225:       goto ok1;
226:     }
227:     aa = aav + ia[i];
228:     for (j = 0; j < na; j++) {
229:       if (aa[j] != 0.0) goto ok1;
230:     }
231:     bb = PetscSafePointerPlusOffset(bav, ib[i]);
232:     for (j = 0; j < nb; j++) {
233:       if (bb[j] != 0.0) goto ok1;
234:     }
235:     cnt++;
236:   ok1:;
237:   }
238:   PetscCallMPI(MPIU_Allreduce(&cnt, &n0rows, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)M)));
239:   if (!n0rows) {
240:     PetscCall(MatSeqAIJRestoreArrayRead(mat->A, &aav));
241:     PetscCall(MatSeqAIJRestoreArrayRead(mat->B, &bav));
242:     PetscFunctionReturn(PETSC_SUCCESS);
243:   }
244:   PetscCall(PetscMalloc1(M->rmap->n - cnt, &rows));
245:   cnt = 0;
246:   for (i = 0; i < m; i++) {
247:     na = ia[i + 1] - ia[i];
248:     nb = ib[i + 1] - ib[i];
249:     if (!na && !nb) continue;
250:     aa = aav + ia[i];
251:     for (j = 0; j < na; j++) {
252:       if (aa[j] != 0.0) {
253:         rows[cnt++] = rstart + i;
254:         goto ok2;
255:       }
256:     }
257:     bb = PetscSafePointerPlusOffset(bav, ib[i]);
258:     for (j = 0; j < nb; j++) {
259:       if (bb[j] != 0.0) {
260:         rows[cnt++] = rstart + i;
261:         goto ok2;
262:       }
263:     }
264:   ok2:;
265:   }
266:   PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)M), cnt, rows, PETSC_OWN_POINTER, keptrows));
267:   PetscCall(MatSeqAIJRestoreArrayRead(mat->A, &aav));
268:   PetscCall(MatSeqAIJRestoreArrayRead(mat->B, &bav));
269:   PetscFunctionReturn(PETSC_SUCCESS);
270: }

272: static PetscErrorCode MatDiagonalSet_MPIAIJ(Mat Y, Vec D, InsertMode is)
273: {
274:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)Y->data;
275:   PetscBool   cong;

277:   PetscFunctionBegin;
278:   PetscCall(MatHasCongruentLayouts(Y, &cong));
279:   if (Y->assembled && cong) {
280:     PetscCall(MatDiagonalSet(aij->A, D, is));
281:   } else {
282:     PetscCall(MatDiagonalSet_Default(Y, D, is));
283:   }
284:   PetscFunctionReturn(PETSC_SUCCESS);
285: }

287: static PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M, IS *zrows)
288: {
289:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)M->data;
290:   PetscInt    i, rstart, nrows, *rows;

292:   PetscFunctionBegin;
293:   *zrows = NULL;
294:   PetscCall(MatFindZeroDiagonals_SeqAIJ_Private(aij->A, &nrows, &rows));
295:   PetscCall(MatGetOwnershipRange(M, &rstart, NULL));
296:   for (i = 0; i < nrows; i++) rows[i] += rstart;
297:   PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)M), nrows, rows, PETSC_OWN_POINTER, zrows));
298:   PetscFunctionReturn(PETSC_SUCCESS);
299: }

301: static PetscErrorCode MatGetColumnReductions_MPIAIJ(Mat A, PetscInt type, PetscReal *reductions)
302: {
303:   Mat_MPIAIJ        *aij = (Mat_MPIAIJ *)A->data;
304:   PetscInt           i, m, n, *garray = aij->garray;
305:   Mat_SeqAIJ        *a_aij = (Mat_SeqAIJ *)aij->A->data;
306:   Mat_SeqAIJ        *b_aij = (Mat_SeqAIJ *)aij->B->data;
307:   PetscReal         *work;
308:   const PetscScalar *dummy;

310:   PetscFunctionBegin;
311:   PetscCall(MatGetSize(A, &m, &n));
312:   PetscCall(PetscCalloc1(n, &work));
313:   PetscCall(MatSeqAIJGetArrayRead(aij->A, &dummy));
314:   PetscCall(MatSeqAIJRestoreArrayRead(aij->A, &dummy));
315:   PetscCall(MatSeqAIJGetArrayRead(aij->B, &dummy));
316:   PetscCall(MatSeqAIJRestoreArrayRead(aij->B, &dummy));
317:   if (type == NORM_2) {
318:     for (i = 0; i < a_aij->i[aij->A->rmap->n]; i++) work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i] * a_aij->a[i]);
319:     for (i = 0; i < b_aij->i[aij->B->rmap->n]; i++) work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i] * b_aij->a[i]);
320:   } else if (type == NORM_1) {
321:     for (i = 0; i < a_aij->i[aij->A->rmap->n]; i++) work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
322:     for (i = 0; i < b_aij->i[aij->B->rmap->n]; i++) work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
323:   } else if (type == NORM_INFINITY) {
324:     for (i = 0; i < a_aij->i[aij->A->rmap->n]; i++) work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
325:     for (i = 0; i < b_aij->i[aij->B->rmap->n]; i++) work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]), work[garray[b_aij->j[i]]]);
326:   } else if (type == REDUCTION_SUM_REALPART || type == REDUCTION_MEAN_REALPART) {
327:     for (i = 0; i < a_aij->i[aij->A->rmap->n]; i++) work[A->cmap->rstart + a_aij->j[i]] += PetscRealPart(a_aij->a[i]);
328:     for (i = 0; i < b_aij->i[aij->B->rmap->n]; i++) work[garray[b_aij->j[i]]] += PetscRealPart(b_aij->a[i]);
329:   } else if (type == REDUCTION_SUM_IMAGINARYPART || type == REDUCTION_MEAN_IMAGINARYPART) {
330:     for (i = 0; i < a_aij->i[aij->A->rmap->n]; i++) work[A->cmap->rstart + a_aij->j[i]] += PetscImaginaryPart(a_aij->a[i]);
331:     for (i = 0; i < b_aij->i[aij->B->rmap->n]; i++) work[garray[b_aij->j[i]]] += PetscImaginaryPart(b_aij->a[i]);
332:   } else SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Unknown reduction type");
333:   if (type == NORM_INFINITY) {
334:     PetscCallMPI(MPIU_Allreduce(work, reductions, n, MPIU_REAL, MPIU_MAX, PetscObjectComm((PetscObject)A)));
335:   } else {
336:     PetscCallMPI(MPIU_Allreduce(work, reductions, n, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)A)));
337:   }
338:   PetscCall(PetscFree(work));
339:   if (type == NORM_2) {
340:     for (i = 0; i < n; i++) reductions[i] = PetscSqrtReal(reductions[i]);
341:   } else if (type == REDUCTION_MEAN_REALPART || type == REDUCTION_MEAN_IMAGINARYPART) {
342:     for (i = 0; i < n; i++) reductions[i] /= m;
343:   }
344:   PetscFunctionReturn(PETSC_SUCCESS);
345: }

347: static PetscErrorCode MatFindOffBlockDiagonalEntries_MPIAIJ(Mat A, IS *is)
348: {
349:   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)A->data;
350:   IS              sis, gis;
351:   const PetscInt *isis, *igis;
352:   PetscInt        n, *iis, nsis, ngis, rstart, i;

354:   PetscFunctionBegin;
355:   PetscCall(MatFindOffBlockDiagonalEntries(a->A, &sis));
356:   PetscCall(MatFindNonzeroRows(a->B, &gis));
357:   PetscCall(ISGetSize(gis, &ngis));
358:   PetscCall(ISGetSize(sis, &nsis));
359:   PetscCall(ISGetIndices(sis, &isis));
360:   PetscCall(ISGetIndices(gis, &igis));

362:   PetscCall(PetscMalloc1(ngis + nsis, &iis));
363:   PetscCall(PetscArraycpy(iis, igis, ngis));
364:   PetscCall(PetscArraycpy(iis + ngis, isis, nsis));
365:   n = ngis + nsis;
366:   PetscCall(PetscSortRemoveDupsInt(&n, iis));
367:   PetscCall(MatGetOwnershipRange(A, &rstart, NULL));
368:   for (i = 0; i < n; i++) iis[i] += rstart;
369:   PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)A), n, iis, PETSC_OWN_POINTER, is));

371:   PetscCall(ISRestoreIndices(sis, &isis));
372:   PetscCall(ISRestoreIndices(gis, &igis));
373:   PetscCall(ISDestroy(&sis));
374:   PetscCall(ISDestroy(&gis));
375:   PetscFunctionReturn(PETSC_SUCCESS);
376: }

378: /*
379:   Local utility routine that creates a mapping from the global column
380: number to the local number in the off-diagonal part of the local
381: storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
382: a slightly higher hash table cost; without it it is not scalable (each processor
383: has an order N integer array but is fast to access.
384: */
385: PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
386: {
387:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;
388:   PetscInt    n   = aij->B->cmap->n, i;

390:   PetscFunctionBegin;
391:   PetscCheck(!n || aij->garray, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MPIAIJ Matrix was assembled but is missing garray");
392: #if defined(PETSC_USE_CTABLE)
393:   PetscCall(PetscHMapICreateWithSize(n, &aij->colmap));
394:   for (i = 0; i < n; i++) PetscCall(PetscHMapISet(aij->colmap, aij->garray[i] + 1, i + 1));
395: #else
396:   PetscCall(PetscCalloc1(mat->cmap->N + 1, &aij->colmap));
397:   for (i = 0; i < n; i++) aij->colmap[aij->garray[i]] = i + 1;
398: #endif
399:   PetscFunctionReturn(PETSC_SUCCESS);
400: }

402: #define MatSetValues_SeqAIJ_A_Private(row, col, value, addv, orow, ocol) \
403:   do { \
404:     if (col <= lastcol1) low1 = 0; \
405:     else high1 = nrow1; \
406:     lastcol1 = col; \
407:     while (high1 - low1 > 5) { \
408:       t = (low1 + high1) / 2; \
409:       if (rp1[t] > col) high1 = t; \
410:       else low1 = t; \
411:     } \
412:     for (_i = low1; _i < high1; _i++) { \
413:       if (rp1[_i] > col) break; \
414:       if (rp1[_i] == col) { \
415:         if (addv == ADD_VALUES) { \
416:           ap1[_i] += value; \
417:           /* Not sure LogFlops will slow dow the code or not */ \
418:           (void)PetscLogFlops(1.0); \
419:         } else ap1[_i] = value; \
420:         goto a_noinsert; \
421:       } \
422:     } \
423:     if (value == 0.0 && ignorezeroentries && row != col) { \
424:       low1  = 0; \
425:       high1 = nrow1; \
426:       goto a_noinsert; \
427:     } \
428:     if (nonew == 1) { \
429:       low1  = 0; \
430:       high1 = nrow1; \
431:       goto a_noinsert; \
432:     } \
433:     PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero at global row/column (%" PetscInt_FMT ", %" PetscInt_FMT ") into matrix", orow, ocol); \
434:     MatSeqXAIJReallocateAIJ(A, am, 1, nrow1, row, col, rmax1, aa, ai, aj, rp1, ap1, aimax, nonew, MatScalar); \
435:     N = nrow1++ - 1; \
436:     a->nz++; \
437:     high1++; \
438:     /* shift up all the later entries in this row */ \
439:     PetscCall(PetscArraymove(rp1 + _i + 1, rp1 + _i, N - _i + 1)); \
440:     PetscCall(PetscArraymove(ap1 + _i + 1, ap1 + _i, N - _i + 1)); \
441:     rp1[_i] = col; \
442:     ap1[_i] = value; \
443:   a_noinsert:; \
444:     ailen[row] = nrow1; \
445:   } while (0)

447: #define MatSetValues_SeqAIJ_B_Private(row, col, value, addv, orow, ocol) \
448:   do { \
449:     if (col <= lastcol2) low2 = 0; \
450:     else high2 = nrow2; \
451:     lastcol2 = col; \
452:     while (high2 - low2 > 5) { \
453:       t = (low2 + high2) / 2; \
454:       if (rp2[t] > col) high2 = t; \
455:       else low2 = t; \
456:     } \
457:     for (_i = low2; _i < high2; _i++) { \
458:       if (rp2[_i] > col) break; \
459:       if (rp2[_i] == col) { \
460:         if (addv == ADD_VALUES) { \
461:           ap2[_i] += value; \
462:           (void)PetscLogFlops(1.0); \
463:         } else ap2[_i] = value; \
464:         goto b_noinsert; \
465:       } \
466:     } \
467:     if (value == 0.0 && ignorezeroentries) { \
468:       low2  = 0; \
469:       high2 = nrow2; \
470:       goto b_noinsert; \
471:     } \
472:     if (nonew == 1) { \
473:       low2  = 0; \
474:       high2 = nrow2; \
475:       goto b_noinsert; \
476:     } \
477:     PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero at global row/column (%" PetscInt_FMT ", %" PetscInt_FMT ") into matrix", orow, ocol); \
478:     MatSeqXAIJReallocateAIJ(B, bm, 1, nrow2, row, col, rmax2, ba, bi, bj, rp2, ap2, bimax, nonew, MatScalar); \
479:     N = nrow2++ - 1; \
480:     b->nz++; \
481:     high2++; \
482:     /* shift up all the later entries in this row */ \
483:     PetscCall(PetscArraymove(rp2 + _i + 1, rp2 + _i, N - _i + 1)); \
484:     PetscCall(PetscArraymove(ap2 + _i + 1, ap2 + _i, N - _i + 1)); \
485:     rp2[_i] = col; \
486:     ap2[_i] = value; \
487:   b_noinsert:; \
488:     bilen[row] = nrow2; \
489:   } while (0)

491: static PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A, PetscInt row, const PetscScalar v[])
492: {
493:   Mat_MPIAIJ  *mat = (Mat_MPIAIJ *)A->data;
494:   Mat_SeqAIJ  *a = (Mat_SeqAIJ *)mat->A->data, *b = (Mat_SeqAIJ *)mat->B->data;
495:   PetscInt     l, *garray                         = mat->garray, diag;
496:   PetscScalar *aa, *ba;

498:   PetscFunctionBegin;
499:   /* code only works for square matrices A */

501:   /* find size of row to the left of the diagonal part */
502:   PetscCall(MatGetOwnershipRange(A, &diag, NULL));
503:   row = row - diag;
504:   for (l = 0; l < b->i[row + 1] - b->i[row]; l++) {
505:     if (garray[b->j[b->i[row] + l]] > diag) break;
506:   }
507:   if (l) {
508:     PetscCall(MatSeqAIJGetArray(mat->B, &ba));
509:     PetscCall(PetscArraycpy(ba + b->i[row], v, l));
510:     PetscCall(MatSeqAIJRestoreArray(mat->B, &ba));
511:   }

513:   /* diagonal part */
514:   if (a->i[row + 1] - a->i[row]) {
515:     PetscCall(MatSeqAIJGetArray(mat->A, &aa));
516:     PetscCall(PetscArraycpy(aa + a->i[row], v + l, a->i[row + 1] - a->i[row]));
517:     PetscCall(MatSeqAIJRestoreArray(mat->A, &aa));
518:   }

520:   /* right of diagonal part */
521:   if (b->i[row + 1] - b->i[row] - l) {
522:     PetscCall(MatSeqAIJGetArray(mat->B, &ba));
523:     PetscCall(PetscArraycpy(ba + b->i[row] + l, v + l + a->i[row + 1] - a->i[row], b->i[row + 1] - b->i[row] - l));
524:     PetscCall(MatSeqAIJRestoreArray(mat->B, &ba));
525:   }
526:   PetscFunctionReturn(PETSC_SUCCESS);
527: }

529: PetscErrorCode MatSetValues_MPIAIJ(Mat mat, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode addv)
530: {
531:   Mat_MPIAIJ *aij   = (Mat_MPIAIJ *)mat->data;
532:   PetscScalar value = 0.0;
533:   PetscInt    i, j, rstart = mat->rmap->rstart, rend = mat->rmap->rend;
534:   PetscInt    cstart = mat->cmap->rstart, cend = mat->cmap->rend, row, col;
535:   PetscBool   roworiented = aij->roworiented;

537:   /* Some Variables required in the macro */
538:   Mat         A     = aij->A;
539:   Mat_SeqAIJ *a     = (Mat_SeqAIJ *)A->data;
540:   PetscInt   *aimax = a->imax, *ai = a->i, *ailen = a->ilen, *aj = a->j;
541:   PetscBool   ignorezeroentries = a->ignorezeroentries;
542:   Mat         B                 = aij->B;
543:   Mat_SeqAIJ *b                 = (Mat_SeqAIJ *)B->data;
544:   PetscInt   *bimax = b->imax, *bi = b->i, *bilen = b->ilen, *bj = b->j, bm = aij->B->rmap->n, am = aij->A->rmap->n;
545:   MatScalar  *aa, *ba;
546:   PetscInt   *rp1, *rp2, ii, nrow1, nrow2, _i, rmax1, rmax2, N, low1, high1, low2, high2, t, lastcol1, lastcol2;
547:   PetscInt    nonew;
548:   MatScalar  *ap1, *ap2;

550:   PetscFunctionBegin;
551:   PetscCall(MatSeqAIJGetArray(A, &aa));
552:   PetscCall(MatSeqAIJGetArray(B, &ba));
553:   for (i = 0; i < m; i++) {
554:     if (im[i] < 0) continue;
555:     PetscCheck(im[i] < mat->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, im[i], mat->rmap->N - 1);
556:     if (im[i] >= rstart && im[i] < rend) {
557:       row      = im[i] - rstart;
558:       lastcol1 = -1;
559:       rp1      = PetscSafePointerPlusOffset(aj, ai[row]);
560:       ap1      = PetscSafePointerPlusOffset(aa, ai[row]);
561:       rmax1    = aimax[row];
562:       nrow1    = ailen[row];
563:       low1     = 0;
564:       high1    = nrow1;
565:       lastcol2 = -1;
566:       rp2      = PetscSafePointerPlusOffset(bj, bi[row]);
567:       ap2      = PetscSafePointerPlusOffset(ba, bi[row]);
568:       rmax2    = bimax[row];
569:       nrow2    = bilen[row];
570:       low2     = 0;
571:       high2    = nrow2;

573:       for (j = 0; j < n; j++) {
574:         if (v) value = roworiented ? v[i * n + j] : v[i + j * m];
575:         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES) && im[i] != in[j]) continue;
576:         if (in[j] >= cstart && in[j] < cend) {
577:           col   = in[j] - cstart;
578:           nonew = a->nonew;
579:           MatSetValues_SeqAIJ_A_Private(row, col, value, addv, im[i], in[j]);
580:         } else if (in[j] < 0) {
581:           continue;
582:         } else {
583:           PetscCheck(in[j] < mat->cmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[j], mat->cmap->N - 1);
584:           if (mat->was_assembled) {
585:             if (!aij->colmap) PetscCall(MatCreateColmap_MPIAIJ_Private(mat));
586: #if defined(PETSC_USE_CTABLE)
587:             PetscCall(PetscHMapIGetWithDefault(aij->colmap, in[j] + 1, 0, &col)); /* map global col ids to local ones */
588:             col--;
589: #else
590:             col = aij->colmap[in[j]] - 1;
591: #endif
592:             if (col < 0 && !((Mat_SeqAIJ *)aij->B->data)->nonew) { /* col < 0 means in[j] is a new col for B */
593:               PetscCall(MatDisAssemble_MPIAIJ(mat, PETSC_FALSE));  /* Change aij->B from reduced/local format to expanded/global format */
594:               col = in[j];
595:               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
596:               B     = aij->B;
597:               b     = (Mat_SeqAIJ *)B->data;
598:               bimax = b->imax;
599:               bi    = b->i;
600:               bilen = b->ilen;
601:               bj    = b->j;
602:               ba    = b->a;
603:               rp2   = PetscSafePointerPlusOffset(bj, bi[row]);
604:               ap2   = PetscSafePointerPlusOffset(ba, bi[row]);
605:               rmax2 = bimax[row];
606:               nrow2 = bilen[row];
607:               low2  = 0;
608:               high2 = nrow2;
609:               bm    = aij->B->rmap->n;
610:               ba    = b->a;
611:             } else if (col < 0 && !(ignorezeroentries && value == 0.0)) {
612:               if (1 == ((Mat_SeqAIJ *)aij->B->data)->nonew) {
613:                 PetscCall(PetscInfo(mat, "Skipping of insertion of new nonzero location in off-diagonal portion of matrix %g(%" PetscInt_FMT ",%" PetscInt_FMT ")\n", (double)PetscRealPart(value), im[i], in[j]));
614:               } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero at global row/column (%" PetscInt_FMT ", %" PetscInt_FMT ") into matrix", im[i], in[j]);
615:             }
616:           } else col = in[j];
617:           nonew = b->nonew;
618:           MatSetValues_SeqAIJ_B_Private(row, col, value, addv, im[i], in[j]);
619:         }
620:       }
621:     } else {
622:       PetscCheck(!mat->nooffprocentries, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Setting off process row %" PetscInt_FMT " even though MatSetOption(,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) was set", im[i]);
623:       if (!aij->donotstash) {
624:         mat->assembled = PETSC_FALSE;
625:         if (roworiented) {
626:           PetscCall(MatStashValuesRow_Private(&mat->stash, im[i], n, in, PetscSafePointerPlusOffset(v, i * n), (PetscBool)(ignorezeroentries && (addv == ADD_VALUES))));
627:         } else {
628:           PetscCall(MatStashValuesCol_Private(&mat->stash, im[i], n, in, PetscSafePointerPlusOffset(v, i), m, (PetscBool)(ignorezeroentries && (addv == ADD_VALUES))));
629:         }
630:       }
631:     }
632:   }
633:   PetscCall(MatSeqAIJRestoreArray(A, &aa)); /* aa, bb might have been free'd due to reallocation above. But we don't access them here */
634:   PetscCall(MatSeqAIJRestoreArray(B, &ba));
635:   PetscFunctionReturn(PETSC_SUCCESS);
636: }

638: /*
639:     This function sets the j and ilen arrays (of the diagonal and off-diagonal part) of an MPIAIJ-matrix.
640:     The values in mat_i have to be sorted and the values in mat_j have to be sorted for each row (CSR-like).
641:     No off-processor parts off the matrix are allowed here and mat->was_assembled has to be PETSC_FALSE.
642: */
643: PetscErrorCode MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(Mat mat, const PetscInt mat_j[], const PetscInt mat_i[])
644: {
645:   Mat_MPIAIJ *aij    = (Mat_MPIAIJ *)mat->data;
646:   Mat         A      = aij->A; /* diagonal part of the matrix */
647:   Mat         B      = aij->B; /* off-diagonal part of the matrix */
648:   Mat_SeqAIJ *a      = (Mat_SeqAIJ *)A->data;
649:   Mat_SeqAIJ *b      = (Mat_SeqAIJ *)B->data;
650:   PetscInt    cstart = mat->cmap->rstart, cend = mat->cmap->rend, col;
651:   PetscInt   *ailen = a->ilen, *aj = a->j;
652:   PetscInt   *bilen = b->ilen, *bj = b->j;
653:   PetscInt    am          = aij->A->rmap->n, j;
654:   PetscInt    diag_so_far = 0, dnz;
655:   PetscInt    offd_so_far = 0, onz;

657:   PetscFunctionBegin;
658:   /* Iterate over all rows of the matrix */
659:   for (j = 0; j < am; j++) {
660:     dnz = onz = 0;
661:     /*  Iterate over all non-zero columns of the current row */
662:     for (col = mat_i[j]; col < mat_i[j + 1]; col++) {
663:       /* If column is in the diagonal */
664:       if (mat_j[col] >= cstart && mat_j[col] < cend) {
665:         aj[diag_so_far++] = mat_j[col] - cstart;
666:         dnz++;
667:       } else { /* off-diagonal entries */
668:         bj[offd_so_far++] = mat_j[col];
669:         onz++;
670:       }
671:     }
672:     ailen[j] = dnz;
673:     bilen[j] = onz;
674:   }
675:   PetscFunctionReturn(PETSC_SUCCESS);
676: }

678: /*
679:     This function sets the local j, a and ilen arrays (of the diagonal and off-diagonal part) of an MPIAIJ-matrix.
680:     The values in mat_i have to be sorted and the values in mat_j have to be sorted for each row (CSR-like).
681:     No off-processor parts off the matrix are allowed here, they are set at a later point by MatSetValues_MPIAIJ.
682:     Also, mat->was_assembled has to be false, otherwise the statement aj[rowstart_diag+dnz_row] = mat_j[col] - cstart;
683:     would not be true and the more complex MatSetValues_MPIAIJ has to be used.
684: */
685: PetscErrorCode MatSetValues_MPIAIJ_CopyFromCSRFormat(Mat mat, const PetscInt mat_j[], const PetscInt mat_i[], const PetscScalar mat_a[])
686: {
687:   Mat_MPIAIJ  *aij  = (Mat_MPIAIJ *)mat->data;
688:   Mat          A    = aij->A; /* diagonal part of the matrix */
689:   Mat          B    = aij->B; /* off-diagonal part of the matrix */
690:   Mat_SeqAIJ  *aijd = (Mat_SeqAIJ *)aij->A->data, *aijo = (Mat_SeqAIJ *)aij->B->data;
691:   Mat_SeqAIJ  *a      = (Mat_SeqAIJ *)A->data;
692:   Mat_SeqAIJ  *b      = (Mat_SeqAIJ *)B->data;
693:   PetscInt     cstart = mat->cmap->rstart, cend = mat->cmap->rend;
694:   PetscInt    *ailen = a->ilen, *aj = a->j;
695:   PetscInt    *bilen = b->ilen, *bj = b->j;
696:   PetscInt     am          = aij->A->rmap->n, j;
697:   PetscInt    *full_diag_i = aijd->i, *full_offd_i = aijo->i; /* These variables can also include non-local elements, which are set at a later point. */
698:   PetscInt     col, dnz_row, onz_row, rowstart_diag, rowstart_offd;
699:   PetscScalar *aa = a->a, *ba = b->a;

701:   PetscFunctionBegin;
702:   /* Iterate over all rows of the matrix */
703:   for (j = 0; j < am; j++) {
704:     dnz_row = onz_row = 0;
705:     rowstart_offd     = full_offd_i[j];
706:     rowstart_diag     = full_diag_i[j];
707:     /*  Iterate over all non-zero columns of the current row */
708:     for (col = mat_i[j]; col < mat_i[j + 1]; col++) {
709:       /* If column is in the diagonal */
710:       if (mat_j[col] >= cstart && mat_j[col] < cend) {
711:         aj[rowstart_diag + dnz_row] = mat_j[col] - cstart;
712:         aa[rowstart_diag + dnz_row] = mat_a[col];
713:         dnz_row++;
714:       } else { /* off-diagonal entries */
715:         bj[rowstart_offd + onz_row] = mat_j[col];
716:         ba[rowstart_offd + onz_row] = mat_a[col];
717:         onz_row++;
718:       }
719:     }
720:     ailen[j] = dnz_row;
721:     bilen[j] = onz_row;
722:   }
723:   PetscFunctionReturn(PETSC_SUCCESS);
724: }

726: static PetscErrorCode MatGetValues_MPIAIJ(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
727: {
728:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;
729:   PetscInt    i, j, rstart = mat->rmap->rstart, rend = mat->rmap->rend;
730:   PetscInt    cstart = mat->cmap->rstart, cend = mat->cmap->rend, row, col;

732:   PetscFunctionBegin;
733:   for (i = 0; i < m; i++) {
734:     if (idxm[i] < 0) continue; /* negative row */
735:     PetscCheck(idxm[i] < mat->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, idxm[i], mat->rmap->N - 1);
736:     PetscCheck(idxm[i] >= rstart && idxm[i] < rend, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only local values currently supported, row requested %" PetscInt_FMT " range [%" PetscInt_FMT " %" PetscInt_FMT ")", idxm[i], rstart, rend);
737:     row = idxm[i] - rstart;
738:     for (j = 0; j < n; j++) {
739:       if (idxn[j] < 0) continue; /* negative column */
740:       PetscCheck(idxn[j] < mat->cmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, idxn[j], mat->cmap->N - 1);
741:       if (idxn[j] >= cstart && idxn[j] < cend) {
742:         col = idxn[j] - cstart;
743:         PetscCall(MatGetValues(aij->A, 1, &row, 1, &col, v + i * n + j));
744:       } else {
745:         if (!aij->colmap) PetscCall(MatCreateColmap_MPIAIJ_Private(mat));
746: #if defined(PETSC_USE_CTABLE)
747:         PetscCall(PetscHMapIGetWithDefault(aij->colmap, idxn[j] + 1, 0, &col));
748:         col--;
749: #else
750:         col = aij->colmap[idxn[j]] - 1;
751: #endif
752:         if ((col < 0) || (aij->garray[col] != idxn[j])) *(v + i * n + j) = 0.0;
753:         else PetscCall(MatGetValues(aij->B, 1, &row, 1, &col, v + i * n + j));
754:       }
755:     }
756:   }
757:   PetscFunctionReturn(PETSC_SUCCESS);
758: }

760: static PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat, MatAssemblyType mode)
761: {
762:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;
763:   PetscInt    nstash, reallocs;

765:   PetscFunctionBegin;
766:   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(PETSC_SUCCESS);

768:   PetscCall(MatStashScatterBegin_Private(mat, &mat->stash, mat->rmap->range));
769:   PetscCall(MatStashGetInfo_Private(&mat->stash, &nstash, &reallocs));
770:   PetscCall(PetscInfo(aij->A, "Stash has %" PetscInt_FMT " entries, uses %" PetscInt_FMT " mallocs.\n", nstash, reallocs));
771:   PetscFunctionReturn(PETSC_SUCCESS);
772: }

774: PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat, MatAssemblyType mode)
775: {
776:   Mat_MPIAIJ  *aij = (Mat_MPIAIJ *)mat->data;
777:   PetscMPIInt  n;
778:   PetscInt     i, j, rstart, ncols, flg;
779:   PetscInt    *row, *col;
780:   PetscBool    other_disassembled;
781:   PetscScalar *val;

783:   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */

785:   PetscFunctionBegin;
786:   if (!aij->donotstash && !mat->nooffprocentries) {
787:     while (1) {
788:       PetscCall(MatStashScatterGetMesg_Private(&mat->stash, &n, &row, &col, &val, &flg));
789:       if (!flg) break;

791:       for (i = 0; i < n;) {
792:         /* Now identify the consecutive vals belonging to the same row */
793:         for (j = i, rstart = row[j]; j < n; j++) {
794:           if (row[j] != rstart) break;
795:         }
796:         if (j < n) ncols = j - i;
797:         else ncols = n - i;
798:         /* Now assemble all these values with a single function call */
799:         PetscCall(MatSetValues_MPIAIJ(mat, 1, row + i, ncols, col + i, val + i, mat->insertmode));
800:         i = j;
801:       }
802:     }
803:     PetscCall(MatStashScatterEnd_Private(&mat->stash));
804:   }
805: #if defined(PETSC_HAVE_DEVICE)
806:   if (mat->offloadmask == PETSC_OFFLOAD_CPU) aij->A->offloadmask = PETSC_OFFLOAD_CPU;
807:   /* We call MatBindToCPU() on aij->A and aij->B here, because if MatBindToCPU_MPIAIJ() is called before assembly, it cannot bind these. */
808:   if (mat->boundtocpu) {
809:     PetscCall(MatBindToCPU(aij->A, PETSC_TRUE));
810:     PetscCall(MatBindToCPU(aij->B, PETSC_TRUE));
811:   }
812: #endif
813:   PetscCall(MatAssemblyBegin(aij->A, mode));
814:   PetscCall(MatAssemblyEnd(aij->A, mode));

816:   /* determine if any processor has disassembled, if so we must
817:      also disassemble ourself, in order that we may reassemble. */
818:   /*
819:      if nonzero structure of submatrix B cannot change then we know that
820:      no processor disassembled thus we can skip this stuff
821:   */
822:   if (!((Mat_SeqAIJ *)aij->B->data)->nonew) {
823:     PetscCallMPI(MPIU_Allreduce(&mat->was_assembled, &other_disassembled, 1, MPIU_BOOL, MPI_LAND, PetscObjectComm((PetscObject)mat)));
824:     if (mat->was_assembled && !other_disassembled) { /* mat on this rank has reduced off-diag B with local col ids, but globally it does not */
825:       PetscCall(MatDisAssemble_MPIAIJ(mat, PETSC_FALSE));
826:     }
827:   }
828:   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) PetscCall(MatSetUpMultiply_MPIAIJ(mat));
829:   PetscCall(MatSetOption(aij->B, MAT_USE_INODES, PETSC_FALSE));
830: #if defined(PETSC_HAVE_DEVICE)
831:   if (mat->offloadmask == PETSC_OFFLOAD_CPU && aij->B->offloadmask != PETSC_OFFLOAD_UNALLOCATED) aij->B->offloadmask = PETSC_OFFLOAD_CPU;
832: #endif
833:   PetscCall(MatAssemblyBegin(aij->B, mode));
834:   PetscCall(MatAssemblyEnd(aij->B, mode));

836:   PetscCall(PetscFree2(aij->rowvalues, aij->rowindices));

838:   aij->rowvalues = NULL;

840:   PetscCall(VecDestroy(&aij->diag));

842:   /* if no new nonzero locations are allowed in matrix then only set the matrix state the first time through */
843:   if ((!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) || !((Mat_SeqAIJ *)aij->A->data)->nonew) {
844:     PetscObjectState state = aij->A->nonzerostate + aij->B->nonzerostate;
845:     PetscCallMPI(MPIU_Allreduce(&state, &mat->nonzerostate, 1, MPIU_INT64, MPI_SUM, PetscObjectComm((PetscObject)mat)));
846:   }
847: #if defined(PETSC_HAVE_DEVICE)
848:   mat->offloadmask = PETSC_OFFLOAD_BOTH;
849: #endif
850:   PetscFunctionReturn(PETSC_SUCCESS);
851: }

853: static PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
854: {
855:   Mat_MPIAIJ *l = (Mat_MPIAIJ *)A->data;

857:   PetscFunctionBegin;
858:   PetscCall(MatZeroEntries(l->A));
859:   PetscCall(MatZeroEntries(l->B));
860:   PetscFunctionReturn(PETSC_SUCCESS);
861: }

863: static PetscErrorCode MatZeroRows_MPIAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
864: {
865:   Mat_MPIAIJ *mat = (Mat_MPIAIJ *)A->data;
866:   PetscInt   *lrows;
867:   PetscInt    r, len;
868:   PetscBool   cong;

870:   PetscFunctionBegin;
871:   /* get locally owned rows */
872:   PetscCall(MatZeroRowsMapLocal_Private(A, N, rows, &len, &lrows));
873:   PetscCall(MatHasCongruentLayouts(A, &cong));
874:   /* fix right-hand side if needed */
875:   if (x && b) {
876:     const PetscScalar *xx;
877:     PetscScalar       *bb;

879:     PetscCheck(cong, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Need matching row/col layout");
880:     PetscCall(VecGetArrayRead(x, &xx));
881:     PetscCall(VecGetArray(b, &bb));
882:     for (r = 0; r < len; ++r) bb[lrows[r]] = diag * xx[lrows[r]];
883:     PetscCall(VecRestoreArrayRead(x, &xx));
884:     PetscCall(VecRestoreArray(b, &bb));
885:   }

887:   if (diag != 0.0 && cong) {
888:     PetscCall(MatZeroRows(mat->A, len, lrows, diag, NULL, NULL));
889:     PetscCall(MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL));
890:   } else if (diag != 0.0) { /* non-square or non congruent layouts -> if keepnonzeropattern is false, we allow for new insertion */
891:     Mat_SeqAIJ *aijA = (Mat_SeqAIJ *)mat->A->data;
892:     Mat_SeqAIJ *aijB = (Mat_SeqAIJ *)mat->B->data;
893:     PetscInt    nnwA, nnwB;
894:     PetscBool   nnzA, nnzB;

896:     nnwA = aijA->nonew;
897:     nnwB = aijB->nonew;
898:     nnzA = aijA->keepnonzeropattern;
899:     nnzB = aijB->keepnonzeropattern;
900:     if (!nnzA) {
901:       PetscCall(PetscInfo(mat->A, "Requested to not keep the pattern and add a nonzero diagonal; may encounter reallocations on diagonal block.\n"));
902:       aijA->nonew = 0;
903:     }
904:     if (!nnzB) {
905:       PetscCall(PetscInfo(mat->B, "Requested to not keep the pattern and add a nonzero diagonal; may encounter reallocations on off-diagonal block.\n"));
906:       aijB->nonew = 0;
907:     }
908:     /* Must zero here before the next loop */
909:     PetscCall(MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL));
910:     PetscCall(MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL));
911:     for (r = 0; r < len; ++r) {
912:       const PetscInt row = lrows[r] + A->rmap->rstart;
913:       if (row >= A->cmap->N) continue;
914:       PetscCall(MatSetValues(A, 1, &row, 1, &row, &diag, INSERT_VALUES));
915:     }
916:     aijA->nonew = nnwA;
917:     aijB->nonew = nnwB;
918:   } else {
919:     PetscCall(MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL));
920:     PetscCall(MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL));
921:   }
922:   PetscCall(PetscFree(lrows));
923:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
924:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));

926:   /* only change matrix nonzero state if pattern was allowed to be changed */
927:   if (!((Mat_SeqAIJ *)mat->A->data)->keepnonzeropattern || !((Mat_SeqAIJ *)mat->A->data)->nonew) {
928:     PetscObjectState state = mat->A->nonzerostate + mat->B->nonzerostate;
929:     PetscCallMPI(MPIU_Allreduce(&state, &A->nonzerostate, 1, MPIU_INT64, MPI_SUM, PetscObjectComm((PetscObject)A)));
930:   }
931:   PetscFunctionReturn(PETSC_SUCCESS);
932: }

934: static PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
935: {
936:   Mat_MPIAIJ        *l = (Mat_MPIAIJ *)A->data;
937:   PetscInt           n = A->rmap->n;
938:   PetscInt           i, j, r, m, len = 0;
939:   PetscInt          *lrows, *owners = A->rmap->range;
940:   PetscMPIInt        p = 0;
941:   PetscSFNode       *rrows;
942:   PetscSF            sf;
943:   const PetscScalar *xx;
944:   PetscScalar       *bb, *mask, *aij_a;
945:   Vec                xmask, lmask;
946:   Mat_SeqAIJ        *aij = (Mat_SeqAIJ *)l->B->data;
947:   const PetscInt    *aj, *ii, *ridx;
948:   PetscScalar       *aa;

950:   PetscFunctionBegin;
951:   /* Create SF where leaves are input rows and roots are owned rows */
952:   PetscCall(PetscMalloc1(n, &lrows));
953:   for (r = 0; r < n; ++r) lrows[r] = -1;
954:   PetscCall(PetscMalloc1(N, &rrows));
955:   for (r = 0; r < N; ++r) {
956:     const PetscInt idx = rows[r];
957:     PetscCheck(idx >= 0 && A->rmap->N > idx, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row %" PetscInt_FMT " out of range [0,%" PetscInt_FMT ")", idx, A->rmap->N);
958:     if (idx < owners[p] || owners[p + 1] <= idx) { /* short-circuit the search if the last p owns this row too */
959:       PetscCall(PetscLayoutFindOwner(A->rmap, idx, &p));
960:     }
961:     rrows[r].rank  = p;
962:     rrows[r].index = rows[r] - owners[p];
963:   }
964:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &sf));
965:   PetscCall(PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER));
966:   /* Collect flags for rows to be zeroed */
967:   PetscCall(PetscSFReduceBegin(sf, MPIU_INT, (PetscInt *)rows, lrows, MPI_LOR));
968:   PetscCall(PetscSFReduceEnd(sf, MPIU_INT, (PetscInt *)rows, lrows, MPI_LOR));
969:   PetscCall(PetscSFDestroy(&sf));
970:   /* Compress and put in row numbers */
971:   for (r = 0; r < n; ++r)
972:     if (lrows[r] >= 0) lrows[len++] = r;
973:   /* zero diagonal part of matrix */
974:   PetscCall(MatZeroRowsColumns(l->A, len, lrows, diag, x, b));
975:   /* handle off-diagonal part of matrix */
976:   PetscCall(MatCreateVecs(A, &xmask, NULL));
977:   PetscCall(VecDuplicate(l->lvec, &lmask));
978:   PetscCall(VecGetArray(xmask, &bb));
979:   for (i = 0; i < len; i++) bb[lrows[i]] = 1;
980:   PetscCall(VecRestoreArray(xmask, &bb));
981:   PetscCall(VecScatterBegin(l->Mvctx, xmask, lmask, ADD_VALUES, SCATTER_FORWARD));
982:   PetscCall(VecScatterEnd(l->Mvctx, xmask, lmask, ADD_VALUES, SCATTER_FORWARD));
983:   PetscCall(VecDestroy(&xmask));
984:   if (x && b) { /* this code is buggy when the row and column layout don't match */
985:     PetscBool cong;

987:     PetscCall(MatHasCongruentLayouts(A, &cong));
988:     PetscCheck(cong, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Need matching row/col layout");
989:     PetscCall(VecScatterBegin(l->Mvctx, x, l->lvec, INSERT_VALUES, SCATTER_FORWARD));
990:     PetscCall(VecScatterEnd(l->Mvctx, x, l->lvec, INSERT_VALUES, SCATTER_FORWARD));
991:     PetscCall(VecGetArrayRead(l->lvec, &xx));
992:     PetscCall(VecGetArray(b, &bb));
993:   }
994:   PetscCall(VecGetArray(lmask, &mask));
995:   /* remove zeroed rows of off-diagonal matrix */
996:   PetscCall(MatSeqAIJGetArray(l->B, &aij_a));
997:   ii = aij->i;
998:   for (i = 0; i < len; i++) PetscCall(PetscArrayzero(PetscSafePointerPlusOffset(aij_a, ii[lrows[i]]), ii[lrows[i] + 1] - ii[lrows[i]]));
999:   /* loop over all elements of off process part of matrix zeroing removed columns*/
1000:   if (aij->compressedrow.use) {
1001:     m    = aij->compressedrow.nrows;
1002:     ii   = aij->compressedrow.i;
1003:     ridx = aij->compressedrow.rindex;
1004:     for (i = 0; i < m; i++) {
1005:       n  = ii[i + 1] - ii[i];
1006:       aj = aij->j + ii[i];
1007:       aa = aij_a + ii[i];

1009:       for (j = 0; j < n; j++) {
1010:         if (PetscAbsScalar(mask[*aj])) {
1011:           if (b) bb[*ridx] -= *aa * xx[*aj];
1012:           *aa = 0.0;
1013:         }
1014:         aa++;
1015:         aj++;
1016:       }
1017:       ridx++;
1018:     }
1019:   } else { /* do not use compressed row format */
1020:     m = l->B->rmap->n;
1021:     for (i = 0; i < m; i++) {
1022:       n  = ii[i + 1] - ii[i];
1023:       aj = aij->j + ii[i];
1024:       aa = aij_a + ii[i];
1025:       for (j = 0; j < n; j++) {
1026:         if (PetscAbsScalar(mask[*aj])) {
1027:           if (b) bb[i] -= *aa * xx[*aj];
1028:           *aa = 0.0;
1029:         }
1030:         aa++;
1031:         aj++;
1032:       }
1033:     }
1034:   }
1035:   if (x && b) {
1036:     PetscCall(VecRestoreArray(b, &bb));
1037:     PetscCall(VecRestoreArrayRead(l->lvec, &xx));
1038:   }
1039:   PetscCall(MatSeqAIJRestoreArray(l->B, &aij_a));
1040:   PetscCall(VecRestoreArray(lmask, &mask));
1041:   PetscCall(VecDestroy(&lmask));
1042:   PetscCall(PetscFree(lrows));

1044:   /* only change matrix nonzero state if pattern was allowed to be changed */
1045:   if (!((Mat_SeqAIJ *)l->A->data)->nonew) {
1046:     PetscObjectState state = l->A->nonzerostate + l->B->nonzerostate;
1047:     PetscCallMPI(MPIU_Allreduce(&state, &A->nonzerostate, 1, MPIU_INT64, MPI_SUM, PetscObjectComm((PetscObject)A)));
1048:   }
1049:   PetscFunctionReturn(PETSC_SUCCESS);
1050: }

1052: static PetscErrorCode MatMult_MPIAIJ(Mat A, Vec xx, Vec yy)
1053: {
1054:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
1055:   PetscInt    nt;
1056:   VecScatter  Mvctx = a->Mvctx;

1058:   PetscFunctionBegin;
1059:   PetscCall(VecGetLocalSize(xx, &nt));
1060:   PetscCheck(nt == A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Incompatible partition of A (%" PetscInt_FMT ") and xx (%" PetscInt_FMT ")", A->cmap->n, nt);
1061:   PetscCall(VecScatterBegin(Mvctx, xx, a->lvec, INSERT_VALUES, SCATTER_FORWARD));
1062:   PetscUseTypeMethod(a->A, mult, xx, yy);
1063:   PetscCall(VecScatterEnd(Mvctx, xx, a->lvec, INSERT_VALUES, SCATTER_FORWARD));
1064:   PetscUseTypeMethod(a->B, multadd, a->lvec, yy, yy);
1065:   PetscFunctionReturn(PETSC_SUCCESS);
1066: }

1068: static PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A, Vec bb, Vec xx)
1069: {
1070:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1072:   PetscFunctionBegin;
1073:   PetscCall(MatMultDiagonalBlock(a->A, bb, xx));
1074:   PetscFunctionReturn(PETSC_SUCCESS);
1075: }

1077: static PetscErrorCode MatMultAdd_MPIAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1078: {
1079:   Mat_MPIAIJ *a     = (Mat_MPIAIJ *)A->data;
1080:   VecScatter  Mvctx = a->Mvctx;

1082:   PetscFunctionBegin;
1083:   PetscCall(VecScatterBegin(Mvctx, xx, a->lvec, INSERT_VALUES, SCATTER_FORWARD));
1084:   PetscCall((*a->A->ops->multadd)(a->A, xx, yy, zz));
1085:   PetscCall(VecScatterEnd(Mvctx, xx, a->lvec, INSERT_VALUES, SCATTER_FORWARD));
1086:   PetscCall((*a->B->ops->multadd)(a->B, a->lvec, zz, zz));
1087:   PetscFunctionReturn(PETSC_SUCCESS);
1088: }

1090: static PetscErrorCode MatMultTranspose_MPIAIJ(Mat A, Vec xx, Vec yy)
1091: {
1092:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1094:   PetscFunctionBegin;
1095:   /* do nondiagonal part */
1096:   PetscCall((*a->B->ops->multtranspose)(a->B, xx, a->lvec));
1097:   /* do local part */
1098:   PetscCall((*a->A->ops->multtranspose)(a->A, xx, yy));
1099:   /* add partial results together */
1100:   PetscCall(VecScatterBegin(a->Mvctx, a->lvec, yy, ADD_VALUES, SCATTER_REVERSE));
1101:   PetscCall(VecScatterEnd(a->Mvctx, a->lvec, yy, ADD_VALUES, SCATTER_REVERSE));
1102:   PetscFunctionReturn(PETSC_SUCCESS);
1103: }

1105: static PetscErrorCode MatIsTranspose_MPIAIJ(Mat Amat, Mat Bmat, PetscReal tol, PetscBool *f)
1106: {
1107:   MPI_Comm    comm;
1108:   Mat_MPIAIJ *Aij = (Mat_MPIAIJ *)Amat->data, *Bij = (Mat_MPIAIJ *)Bmat->data;
1109:   Mat         Adia = Aij->A, Bdia = Bij->A, Aoff, Boff, *Aoffs, *Boffs;
1110:   IS          Me, Notme;
1111:   PetscInt    M, N, first, last, *notme, i;
1112:   PetscBool   lf;
1113:   PetscMPIInt size;

1115:   PetscFunctionBegin;
1116:   /* Easy test: symmetric diagonal block */
1117:   PetscCall(MatIsTranspose(Adia, Bdia, tol, &lf));
1118:   PetscCallMPI(MPIU_Allreduce(&lf, f, 1, MPIU_BOOL, MPI_LAND, PetscObjectComm((PetscObject)Amat)));
1119:   if (!*f) PetscFunctionReturn(PETSC_SUCCESS);
1120:   PetscCall(PetscObjectGetComm((PetscObject)Amat, &comm));
1121:   PetscCallMPI(MPI_Comm_size(comm, &size));
1122:   if (size == 1) PetscFunctionReturn(PETSC_SUCCESS);

1124:   /* Hard test: off-diagonal block. This takes a MatCreateSubMatrix. */
1125:   PetscCall(MatGetSize(Amat, &M, &N));
1126:   PetscCall(MatGetOwnershipRange(Amat, &first, &last));
1127:   PetscCall(PetscMalloc1(N - last + first, &notme));
1128:   for (i = 0; i < first; i++) notme[i] = i;
1129:   for (i = last; i < M; i++) notme[i - last + first] = i;
1130:   PetscCall(ISCreateGeneral(MPI_COMM_SELF, N - last + first, notme, PETSC_COPY_VALUES, &Notme));
1131:   PetscCall(ISCreateStride(MPI_COMM_SELF, last - first, first, 1, &Me));
1132:   PetscCall(MatCreateSubMatrices(Amat, 1, &Me, &Notme, MAT_INITIAL_MATRIX, &Aoffs));
1133:   Aoff = Aoffs[0];
1134:   PetscCall(MatCreateSubMatrices(Bmat, 1, &Notme, &Me, MAT_INITIAL_MATRIX, &Boffs));
1135:   Boff = Boffs[0];
1136:   PetscCall(MatIsTranspose(Aoff, Boff, tol, f));
1137:   PetscCall(MatDestroyMatrices(1, &Aoffs));
1138:   PetscCall(MatDestroyMatrices(1, &Boffs));
1139:   PetscCall(ISDestroy(&Me));
1140:   PetscCall(ISDestroy(&Notme));
1141:   PetscCall(PetscFree(notme));
1142:   PetscFunctionReturn(PETSC_SUCCESS);
1143: }

1145: static PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1146: {
1147:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1149:   PetscFunctionBegin;
1150:   /* do nondiagonal part */
1151:   PetscCall((*a->B->ops->multtranspose)(a->B, xx, a->lvec));
1152:   /* do local part */
1153:   PetscCall((*a->A->ops->multtransposeadd)(a->A, xx, yy, zz));
1154:   /* add partial results together */
1155:   PetscCall(VecScatterBegin(a->Mvctx, a->lvec, zz, ADD_VALUES, SCATTER_REVERSE));
1156:   PetscCall(VecScatterEnd(a->Mvctx, a->lvec, zz, ADD_VALUES, SCATTER_REVERSE));
1157:   PetscFunctionReturn(PETSC_SUCCESS);
1158: }

1160: /*
1161:   This only works correctly for square matrices where the subblock A->A is the
1162:    diagonal block
1163: */
1164: static PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A, Vec v)
1165: {
1166:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1168:   PetscFunctionBegin;
1169:   PetscCheck(A->rmap->N == A->cmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Supports only square matrix where A->A is diag block");
1170:   PetscCheck(A->rmap->rstart == A->cmap->rstart && A->rmap->rend == A->cmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "row partition must equal col partition");
1171:   PetscCall(MatGetDiagonal(a->A, v));
1172:   PetscFunctionReturn(PETSC_SUCCESS);
1173: }

1175: static PetscErrorCode MatScale_MPIAIJ(Mat A, PetscScalar aa)
1176: {
1177:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1179:   PetscFunctionBegin;
1180:   PetscCall(MatScale(a->A, aa));
1181:   PetscCall(MatScale(a->B, aa));
1182:   PetscFunctionReturn(PETSC_SUCCESS);
1183: }

1185: static PetscErrorCode MatView_MPIAIJ_Binary(Mat mat, PetscViewer viewer)
1186: {
1187:   Mat_MPIAIJ        *aij    = (Mat_MPIAIJ *)mat->data;
1188:   Mat_SeqAIJ        *A      = (Mat_SeqAIJ *)aij->A->data;
1189:   Mat_SeqAIJ        *B      = (Mat_SeqAIJ *)aij->B->data;
1190:   const PetscInt    *garray = aij->garray;
1191:   const PetscScalar *aa, *ba;
1192:   PetscInt           header[4], M, N, m, rs, cs, cnt, i, ja, jb;
1193:   PetscInt64         nz, hnz;
1194:   PetscInt          *rowlens;
1195:   PetscInt          *colidxs;
1196:   PetscScalar       *matvals;
1197:   PetscMPIInt        rank;

1199:   PetscFunctionBegin;
1200:   PetscCall(PetscViewerSetUp(viewer));

1202:   M  = mat->rmap->N;
1203:   N  = mat->cmap->N;
1204:   m  = mat->rmap->n;
1205:   rs = mat->rmap->rstart;
1206:   cs = mat->cmap->rstart;
1207:   nz = A->nz + B->nz;

1209:   /* write matrix header */
1210:   header[0] = MAT_FILE_CLASSID;
1211:   header[1] = M;
1212:   header[2] = N;
1213:   PetscCallMPI(MPI_Reduce(&nz, &hnz, 1, MPIU_INT64, MPI_SUM, 0, PetscObjectComm((PetscObject)mat)));
1214:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)mat), &rank));
1215:   if (rank == 0) PetscCall(PetscIntCast(hnz, &header[3]));
1216:   PetscCall(PetscViewerBinaryWrite(viewer, header, 4, PETSC_INT));

1218:   /* fill in and store row lengths  */
1219:   PetscCall(PetscMalloc1(m, &rowlens));
1220:   for (i = 0; i < m; i++) rowlens[i] = A->i[i + 1] - A->i[i] + B->i[i + 1] - B->i[i];
1221:   PetscCall(PetscViewerBinaryWriteAll(viewer, rowlens, m, rs, M, PETSC_INT));
1222:   PetscCall(PetscFree(rowlens));

1224:   /* fill in and store column indices */
1225:   PetscCall(PetscMalloc1(nz, &colidxs));
1226:   for (cnt = 0, i = 0; i < m; i++) {
1227:     for (jb = B->i[i]; jb < B->i[i + 1]; jb++) {
1228:       if (garray[B->j[jb]] > cs) break;
1229:       colidxs[cnt++] = garray[B->j[jb]];
1230:     }
1231:     for (ja = A->i[i]; ja < A->i[i + 1]; ja++) colidxs[cnt++] = A->j[ja] + cs;
1232:     for (; jb < B->i[i + 1]; jb++) colidxs[cnt++] = garray[B->j[jb]];
1233:   }
1234:   PetscCheck(cnt == nz, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal PETSc error: cnt = %" PetscInt_FMT " nz = %" PetscInt64_FMT, cnt, nz);
1235:   PetscCall(PetscViewerBinaryWriteAll(viewer, colidxs, nz, PETSC_DETERMINE, PETSC_DETERMINE, PETSC_INT));
1236:   PetscCall(PetscFree(colidxs));

1238:   /* fill in and store nonzero values */
1239:   PetscCall(MatSeqAIJGetArrayRead(aij->A, &aa));
1240:   PetscCall(MatSeqAIJGetArrayRead(aij->B, &ba));
1241:   PetscCall(PetscMalloc1(nz, &matvals));
1242:   for (cnt = 0, i = 0; i < m; i++) {
1243:     for (jb = B->i[i]; jb < B->i[i + 1]; jb++) {
1244:       if (garray[B->j[jb]] > cs) break;
1245:       matvals[cnt++] = ba[jb];
1246:     }
1247:     for (ja = A->i[i]; ja < A->i[i + 1]; ja++) matvals[cnt++] = aa[ja];
1248:     for (; jb < B->i[i + 1]; jb++) matvals[cnt++] = ba[jb];
1249:   }
1250:   PetscCall(MatSeqAIJRestoreArrayRead(aij->A, &aa));
1251:   PetscCall(MatSeqAIJRestoreArrayRead(aij->B, &ba));
1252:   PetscCheck(cnt == nz, PETSC_COMM_SELF, PETSC_ERR_LIB, "Internal PETSc error: cnt = %" PetscInt_FMT " nz = %" PetscInt64_FMT, cnt, nz);
1253:   PetscCall(PetscViewerBinaryWriteAll(viewer, matvals, nz, PETSC_DETERMINE, PETSC_DETERMINE, PETSC_SCALAR));
1254:   PetscCall(PetscFree(matvals));

1256:   /* write block size option to the viewer's .info file */
1257:   PetscCall(MatView_Binary_BlockSizes(mat, viewer));
1258:   PetscFunctionReturn(PETSC_SUCCESS);
1259: }

1261: #include <petscdraw.h>
1262: static PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat, PetscViewer viewer)
1263: {
1264:   Mat_MPIAIJ       *aij  = (Mat_MPIAIJ *)mat->data;
1265:   PetscMPIInt       rank = aij->rank, size = aij->size;
1266:   PetscBool         isdraw, iascii, isbinary;
1267:   PetscViewer       sviewer;
1268:   PetscViewerFormat format;

1270:   PetscFunctionBegin;
1271:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
1272:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
1273:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
1274:   if (iascii) {
1275:     PetscCall(PetscViewerGetFormat(viewer, &format));
1276:     if (format == PETSC_VIEWER_LOAD_BALANCE) {
1277:       PetscInt i, nmax = 0, nmin = PETSC_INT_MAX, navg = 0, *nz, nzlocal = ((Mat_SeqAIJ *)aij->A->data)->nz + ((Mat_SeqAIJ *)aij->B->data)->nz;
1278:       PetscCall(PetscMalloc1(size, &nz));
1279:       PetscCallMPI(MPI_Allgather(&nzlocal, 1, MPIU_INT, nz, 1, MPIU_INT, PetscObjectComm((PetscObject)mat)));
1280:       for (i = 0; i < size; i++) {
1281:         nmax = PetscMax(nmax, nz[i]);
1282:         nmin = PetscMin(nmin, nz[i]);
1283:         navg += nz[i];
1284:       }
1285:       PetscCall(PetscFree(nz));
1286:       navg = navg / size;
1287:       PetscCall(PetscViewerASCIIPrintf(viewer, "Load Balance - Nonzeros: Min %" PetscInt_FMT "  avg %" PetscInt_FMT "  max %" PetscInt_FMT "\n", nmin, navg, nmax));
1288:       PetscFunctionReturn(PETSC_SUCCESS);
1289:     }
1290:     PetscCall(PetscViewerGetFormat(viewer, &format));
1291:     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1292:       MatInfo   info;
1293:       PetscInt *inodes = NULL;

1295:       PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)mat), &rank));
1296:       PetscCall(MatGetInfo(mat, MAT_LOCAL, &info));
1297:       PetscCall(MatInodeGetInodeSizes(aij->A, NULL, &inodes, NULL));
1298:       PetscCall(PetscViewerASCIIPushSynchronized(viewer));
1299:       if (!inodes) {
1300:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] Local rows %" PetscInt_FMT " nz %" PetscInt_FMT " nz alloced %" PetscInt_FMT " mem %g, not using I-node routines\n", rank, mat->rmap->n, (PetscInt)info.nz_used, (PetscInt)info.nz_allocated,
1301:                                                      info.memory));
1302:       } else {
1303:         PetscCall(
1304:           PetscViewerASCIISynchronizedPrintf(viewer, "[%d] Local rows %" PetscInt_FMT " nz %" PetscInt_FMT " nz alloced %" PetscInt_FMT " mem %g, using I-node routines\n", rank, mat->rmap->n, (PetscInt)info.nz_used, (PetscInt)info.nz_allocated, info.memory));
1305:       }
1306:       PetscCall(MatGetInfo(aij->A, MAT_LOCAL, &info));
1307:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] on-diagonal part: nz %" PetscInt_FMT " \n", rank, (PetscInt)info.nz_used));
1308:       PetscCall(MatGetInfo(aij->B, MAT_LOCAL, &info));
1309:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] off-diagonal part: nz %" PetscInt_FMT " \n", rank, (PetscInt)info.nz_used));
1310:       PetscCall(PetscViewerFlush(viewer));
1311:       PetscCall(PetscViewerASCIIPopSynchronized(viewer));
1312:       PetscCall(PetscViewerASCIIPrintf(viewer, "Information on VecScatter used in matrix-vector product: \n"));
1313:       PetscCall(VecScatterView(aij->Mvctx, viewer));
1314:       PetscFunctionReturn(PETSC_SUCCESS);
1315:     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1316:       PetscInt inodecount, inodelimit, *inodes;
1317:       PetscCall(MatInodeGetInodeSizes(aij->A, &inodecount, &inodes, &inodelimit));
1318:       if (inodes) {
1319:         PetscCall(PetscViewerASCIIPrintf(viewer, "using I-node (on process 0) routines: found %" PetscInt_FMT " nodes, limit used is %" PetscInt_FMT "\n", inodecount, inodelimit));
1320:       } else {
1321:         PetscCall(PetscViewerASCIIPrintf(viewer, "not using I-node (on process 0) routines\n"));
1322:       }
1323:       PetscFunctionReturn(PETSC_SUCCESS);
1324:     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1325:       PetscFunctionReturn(PETSC_SUCCESS);
1326:     }
1327:   } else if (isbinary) {
1328:     if (size == 1) {
1329:       PetscCall(PetscObjectSetName((PetscObject)aij->A, ((PetscObject)mat)->name));
1330:       PetscCall(MatView(aij->A, viewer));
1331:     } else {
1332:       PetscCall(MatView_MPIAIJ_Binary(mat, viewer));
1333:     }
1334:     PetscFunctionReturn(PETSC_SUCCESS);
1335:   } else if (iascii && size == 1) {
1336:     PetscCall(PetscObjectSetName((PetscObject)aij->A, ((PetscObject)mat)->name));
1337:     PetscCall(MatView(aij->A, viewer));
1338:     PetscFunctionReturn(PETSC_SUCCESS);
1339:   } else if (isdraw) {
1340:     PetscDraw draw;
1341:     PetscBool isnull;
1342:     PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
1343:     PetscCall(PetscDrawIsNull(draw, &isnull));
1344:     if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
1345:   }

1347:   { /* assemble the entire matrix onto first processor */
1348:     Mat A = NULL, Av;
1349:     IS  isrow, iscol;

1351:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), rank == 0 ? mat->rmap->N : 0, 0, 1, &isrow));
1352:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), rank == 0 ? mat->cmap->N : 0, 0, 1, &iscol));
1353:     PetscCall(MatCreateSubMatrix(mat, isrow, iscol, MAT_INITIAL_MATRIX, &A));
1354:     PetscCall(MatMPIAIJGetSeqAIJ(A, &Av, NULL, NULL));
1355:     /*  The commented code uses MatCreateSubMatrices instead */
1356:     /*
1357:     Mat *AA, A = NULL, Av;
1358:     IS  isrow,iscol;

1360:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat),rank == 0 ? mat->rmap->N : 0,0,1,&isrow));
1361:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat),rank == 0 ? mat->cmap->N : 0,0,1,&iscol));
1362:     PetscCall(MatCreateSubMatrices(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&AA));
1363:     if (rank == 0) {
1364:        PetscCall(PetscObjectReference((PetscObject)AA[0]));
1365:        A    = AA[0];
1366:        Av   = AA[0];
1367:     }
1368:     PetscCall(MatDestroySubMatrices(1,&AA));
1369: */
1370:     PetscCall(ISDestroy(&iscol));
1371:     PetscCall(ISDestroy(&isrow));
1372:     /*
1373:        Everyone has to call to draw the matrix since the graphics waits are
1374:        synchronized across all processors that share the PetscDraw object
1375:     */
1376:     PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
1377:     if (rank == 0) {
1378:       if (((PetscObject)mat)->name) PetscCall(PetscObjectSetName((PetscObject)Av, ((PetscObject)mat)->name));
1379:       PetscCall(MatView_SeqAIJ(Av, sviewer));
1380:     }
1381:     PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
1382:     PetscCall(MatDestroy(&A));
1383:   }
1384:   PetscFunctionReturn(PETSC_SUCCESS);
1385: }

1387: PetscErrorCode MatView_MPIAIJ(Mat mat, PetscViewer viewer)
1388: {
1389:   PetscBool iascii, isdraw, issocket, isbinary;

1391:   PetscFunctionBegin;
1392:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
1393:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
1394:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
1395:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSOCKET, &issocket));
1396:   if (iascii || isdraw || isbinary || issocket) PetscCall(MatView_MPIAIJ_ASCIIorDraworSocket(mat, viewer));
1397:   PetscFunctionReturn(PETSC_SUCCESS);
1398: }

1400: static PetscErrorCode MatSOR_MPIAIJ(Mat matin, Vec bb, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec xx)
1401: {
1402:   Mat_MPIAIJ *mat = (Mat_MPIAIJ *)matin->data;
1403:   Vec         bb1 = NULL;
1404:   PetscBool   hasop;

1406:   PetscFunctionBegin;
1407:   if (flag == SOR_APPLY_UPPER) {
1408:     PetscCall((*mat->A->ops->sor)(mat->A, bb, omega, flag, fshift, lits, 1, xx));
1409:     PetscFunctionReturn(PETSC_SUCCESS);
1410:   }

1412:   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) PetscCall(VecDuplicate(bb, &bb1));

1414:   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1415:     if (flag & SOR_ZERO_INITIAL_GUESS) {
1416:       PetscCall((*mat->A->ops->sor)(mat->A, bb, omega, flag, fshift, lits, 1, xx));
1417:       its--;
1418:     }

1420:     while (its--) {
1421:       PetscCall(VecScatterBegin(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));
1422:       PetscCall(VecScatterEnd(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));

1424:       /* update rhs: bb1 = bb - B*x */
1425:       PetscCall(VecScale(mat->lvec, -1.0));
1426:       PetscCall((*mat->B->ops->multadd)(mat->B, mat->lvec, bb, bb1));

1428:       /* local sweep */
1429:       PetscCall((*mat->A->ops->sor)(mat->A, bb1, omega, SOR_SYMMETRIC_SWEEP, fshift, lits, 1, xx));
1430:     }
1431:   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1432:     if (flag & SOR_ZERO_INITIAL_GUESS) {
1433:       PetscCall((*mat->A->ops->sor)(mat->A, bb, omega, flag, fshift, lits, 1, xx));
1434:       its--;
1435:     }
1436:     while (its--) {
1437:       PetscCall(VecScatterBegin(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));
1438:       PetscCall(VecScatterEnd(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));

1440:       /* update rhs: bb1 = bb - B*x */
1441:       PetscCall(VecScale(mat->lvec, -1.0));
1442:       PetscCall((*mat->B->ops->multadd)(mat->B, mat->lvec, bb, bb1));

1444:       /* local sweep */
1445:       PetscCall((*mat->A->ops->sor)(mat->A, bb1, omega, SOR_FORWARD_SWEEP, fshift, lits, 1, xx));
1446:     }
1447:   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1448:     if (flag & SOR_ZERO_INITIAL_GUESS) {
1449:       PetscCall((*mat->A->ops->sor)(mat->A, bb, omega, flag, fshift, lits, 1, xx));
1450:       its--;
1451:     }
1452:     while (its--) {
1453:       PetscCall(VecScatterBegin(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));
1454:       PetscCall(VecScatterEnd(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));

1456:       /* update rhs: bb1 = bb - B*x */
1457:       PetscCall(VecScale(mat->lvec, -1.0));
1458:       PetscCall((*mat->B->ops->multadd)(mat->B, mat->lvec, bb, bb1));

1460:       /* local sweep */
1461:       PetscCall((*mat->A->ops->sor)(mat->A, bb1, omega, SOR_BACKWARD_SWEEP, fshift, lits, 1, xx));
1462:     }
1463:   } else if (flag & SOR_EISENSTAT) {
1464:     Vec xx1;

1466:     PetscCall(VecDuplicate(bb, &xx1));
1467:     PetscCall((*mat->A->ops->sor)(mat->A, bb, omega, (MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP), fshift, lits, 1, xx));

1469:     PetscCall(VecScatterBegin(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));
1470:     PetscCall(VecScatterEnd(mat->Mvctx, xx, mat->lvec, INSERT_VALUES, SCATTER_FORWARD));
1471:     if (!mat->diag) {
1472:       PetscCall(MatCreateVecs(matin, &mat->diag, NULL));
1473:       PetscCall(MatGetDiagonal(matin, mat->diag));
1474:     }
1475:     PetscCall(MatHasOperation(matin, MATOP_MULT_DIAGONAL_BLOCK, &hasop));
1476:     if (hasop) {
1477:       PetscCall(MatMultDiagonalBlock(matin, xx, bb1));
1478:     } else {
1479:       PetscCall(VecPointwiseMult(bb1, mat->diag, xx));
1480:     }
1481:     PetscCall(VecAYPX(bb1, (omega - 2.0) / omega, bb));

1483:     PetscCall(MatMultAdd(mat->B, mat->lvec, bb1, bb1));

1485:     /* local sweep */
1486:     PetscCall((*mat->A->ops->sor)(mat->A, bb1, omega, (MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP), fshift, lits, 1, xx1));
1487:     PetscCall(VecAXPY(xx, 1.0, xx1));
1488:     PetscCall(VecDestroy(&xx1));
1489:   } else SETERRQ(PetscObjectComm((PetscObject)matin), PETSC_ERR_SUP, "Parallel SOR not supported");

1491:   PetscCall(VecDestroy(&bb1));

1493:   matin->factorerrortype = mat->A->factorerrortype;
1494:   PetscFunctionReturn(PETSC_SUCCESS);
1495: }

1497: static PetscErrorCode MatPermute_MPIAIJ(Mat A, IS rowp, IS colp, Mat *B)
1498: {
1499:   Mat             aA, aB, Aperm;
1500:   const PetscInt *rwant, *cwant, *gcols, *ai, *bi, *aj, *bj;
1501:   PetscScalar    *aa, *ba;
1502:   PetscInt        i, j, m, n, ng, anz, bnz, *dnnz, *onnz, *tdnnz, *tonnz, *rdest, *cdest, *work, *gcdest;
1503:   PetscSF         rowsf, sf;
1504:   IS              parcolp = NULL;
1505:   PetscBool       done;

1507:   PetscFunctionBegin;
1508:   PetscCall(MatGetLocalSize(A, &m, &n));
1509:   PetscCall(ISGetIndices(rowp, &rwant));
1510:   PetscCall(ISGetIndices(colp, &cwant));
1511:   PetscCall(PetscMalloc3(PetscMax(m, n), &work, m, &rdest, n, &cdest));

1513:   /* Invert row permutation to find out where my rows should go */
1514:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &rowsf));
1515:   PetscCall(PetscSFSetGraphLayout(rowsf, A->rmap, A->rmap->n, NULL, PETSC_OWN_POINTER, rwant));
1516:   PetscCall(PetscSFSetFromOptions(rowsf));
1517:   for (i = 0; i < m; i++) work[i] = A->rmap->rstart + i;
1518:   PetscCall(PetscSFReduceBegin(rowsf, MPIU_INT, work, rdest, MPI_REPLACE));
1519:   PetscCall(PetscSFReduceEnd(rowsf, MPIU_INT, work, rdest, MPI_REPLACE));

1521:   /* Invert column permutation to find out where my columns should go */
1522:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &sf));
1523:   PetscCall(PetscSFSetGraphLayout(sf, A->cmap, A->cmap->n, NULL, PETSC_OWN_POINTER, cwant));
1524:   PetscCall(PetscSFSetFromOptions(sf));
1525:   for (i = 0; i < n; i++) work[i] = A->cmap->rstart + i;
1526:   PetscCall(PetscSFReduceBegin(sf, MPIU_INT, work, cdest, MPI_REPLACE));
1527:   PetscCall(PetscSFReduceEnd(sf, MPIU_INT, work, cdest, MPI_REPLACE));
1528:   PetscCall(PetscSFDestroy(&sf));

1530:   PetscCall(ISRestoreIndices(rowp, &rwant));
1531:   PetscCall(ISRestoreIndices(colp, &cwant));
1532:   PetscCall(MatMPIAIJGetSeqAIJ(A, &aA, &aB, &gcols));

1534:   /* Find out where my gcols should go */
1535:   PetscCall(MatGetSize(aB, NULL, &ng));
1536:   PetscCall(PetscMalloc1(ng, &gcdest));
1537:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &sf));
1538:   PetscCall(PetscSFSetGraphLayout(sf, A->cmap, ng, NULL, PETSC_OWN_POINTER, gcols));
1539:   PetscCall(PetscSFSetFromOptions(sf));
1540:   PetscCall(PetscSFBcastBegin(sf, MPIU_INT, cdest, gcdest, MPI_REPLACE));
1541:   PetscCall(PetscSFBcastEnd(sf, MPIU_INT, cdest, gcdest, MPI_REPLACE));
1542:   PetscCall(PetscSFDestroy(&sf));

1544:   PetscCall(PetscCalloc4(m, &dnnz, m, &onnz, m, &tdnnz, m, &tonnz));
1545:   PetscCall(MatGetRowIJ(aA, 0, PETSC_FALSE, PETSC_FALSE, &anz, &ai, &aj, &done));
1546:   PetscCall(MatGetRowIJ(aB, 0, PETSC_FALSE, PETSC_FALSE, &bnz, &bi, &bj, &done));
1547:   for (i = 0; i < m; i++) {
1548:     PetscInt    row = rdest[i];
1549:     PetscMPIInt rowner;
1550:     PetscCall(PetscLayoutFindOwner(A->rmap, row, &rowner));
1551:     for (j = ai[i]; j < ai[i + 1]; j++) {
1552:       PetscInt    col = cdest[aj[j]];
1553:       PetscMPIInt cowner;
1554:       PetscCall(PetscLayoutFindOwner(A->cmap, col, &cowner)); /* Could build an index for the columns to eliminate this search */
1555:       if (rowner == cowner) dnnz[i]++;
1556:       else onnz[i]++;
1557:     }
1558:     for (j = bi[i]; j < bi[i + 1]; j++) {
1559:       PetscInt    col = gcdest[bj[j]];
1560:       PetscMPIInt cowner;
1561:       PetscCall(PetscLayoutFindOwner(A->cmap, col, &cowner));
1562:       if (rowner == cowner) dnnz[i]++;
1563:       else onnz[i]++;
1564:     }
1565:   }
1566:   PetscCall(PetscSFBcastBegin(rowsf, MPIU_INT, dnnz, tdnnz, MPI_REPLACE));
1567:   PetscCall(PetscSFBcastEnd(rowsf, MPIU_INT, dnnz, tdnnz, MPI_REPLACE));
1568:   PetscCall(PetscSFBcastBegin(rowsf, MPIU_INT, onnz, tonnz, MPI_REPLACE));
1569:   PetscCall(PetscSFBcastEnd(rowsf, MPIU_INT, onnz, tonnz, MPI_REPLACE));
1570:   PetscCall(PetscSFDestroy(&rowsf));

1572:   PetscCall(MatCreateAIJ(PetscObjectComm((PetscObject)A), A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N, 0, tdnnz, 0, tonnz, &Aperm));
1573:   PetscCall(MatSeqAIJGetArray(aA, &aa));
1574:   PetscCall(MatSeqAIJGetArray(aB, &ba));
1575:   for (i = 0; i < m; i++) {
1576:     PetscInt *acols = dnnz, *bcols = onnz; /* Repurpose now-unneeded arrays */
1577:     PetscInt  j0, rowlen;
1578:     rowlen = ai[i + 1] - ai[i];
1579:     for (j0 = j = 0; j < rowlen; j0 = j) { /* rowlen could be larger than number of rows m, so sum in batches */
1580:       for (; j < PetscMin(rowlen, j0 + m); j++) acols[j - j0] = cdest[aj[ai[i] + j]];
1581:       PetscCall(MatSetValues(Aperm, 1, &rdest[i], j - j0, acols, aa + ai[i] + j0, INSERT_VALUES));
1582:     }
1583:     rowlen = bi[i + 1] - bi[i];
1584:     for (j0 = j = 0; j < rowlen; j0 = j) {
1585:       for (; j < PetscMin(rowlen, j0 + m); j++) bcols[j - j0] = gcdest[bj[bi[i] + j]];
1586:       PetscCall(MatSetValues(Aperm, 1, &rdest[i], j - j0, bcols, ba + bi[i] + j0, INSERT_VALUES));
1587:     }
1588:   }
1589:   PetscCall(MatAssemblyBegin(Aperm, MAT_FINAL_ASSEMBLY));
1590:   PetscCall(MatAssemblyEnd(Aperm, MAT_FINAL_ASSEMBLY));
1591:   PetscCall(MatRestoreRowIJ(aA, 0, PETSC_FALSE, PETSC_FALSE, &anz, &ai, &aj, &done));
1592:   PetscCall(MatRestoreRowIJ(aB, 0, PETSC_FALSE, PETSC_FALSE, &bnz, &bi, &bj, &done));
1593:   PetscCall(MatSeqAIJRestoreArray(aA, &aa));
1594:   PetscCall(MatSeqAIJRestoreArray(aB, &ba));
1595:   PetscCall(PetscFree4(dnnz, onnz, tdnnz, tonnz));
1596:   PetscCall(PetscFree3(work, rdest, cdest));
1597:   PetscCall(PetscFree(gcdest));
1598:   if (parcolp) PetscCall(ISDestroy(&colp));
1599:   *B = Aperm;
1600:   PetscFunctionReturn(PETSC_SUCCESS);
1601: }

1603: static PetscErrorCode MatGetGhosts_MPIAIJ(Mat mat, PetscInt *nghosts, const PetscInt *ghosts[])
1604: {
1605:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

1607:   PetscFunctionBegin;
1608:   PetscCall(MatGetSize(aij->B, NULL, nghosts));
1609:   if (ghosts) *ghosts = aij->garray;
1610:   PetscFunctionReturn(PETSC_SUCCESS);
1611: }

1613: static PetscErrorCode MatGetInfo_MPIAIJ(Mat matin, MatInfoType flag, MatInfo *info)
1614: {
1615:   Mat_MPIAIJ    *mat = (Mat_MPIAIJ *)matin->data;
1616:   Mat            A = mat->A, B = mat->B;
1617:   PetscLogDouble isend[5], irecv[5];

1619:   PetscFunctionBegin;
1620:   info->block_size = 1.0;
1621:   PetscCall(MatGetInfo(A, MAT_LOCAL, info));

1623:   isend[0] = info->nz_used;
1624:   isend[1] = info->nz_allocated;
1625:   isend[2] = info->nz_unneeded;
1626:   isend[3] = info->memory;
1627:   isend[4] = info->mallocs;

1629:   PetscCall(MatGetInfo(B, MAT_LOCAL, info));

1631:   isend[0] += info->nz_used;
1632:   isend[1] += info->nz_allocated;
1633:   isend[2] += info->nz_unneeded;
1634:   isend[3] += info->memory;
1635:   isend[4] += info->mallocs;
1636:   if (flag == MAT_LOCAL) {
1637:     info->nz_used      = isend[0];
1638:     info->nz_allocated = isend[1];
1639:     info->nz_unneeded  = isend[2];
1640:     info->memory       = isend[3];
1641:     info->mallocs      = isend[4];
1642:   } else if (flag == MAT_GLOBAL_MAX) {
1643:     PetscCallMPI(MPIU_Allreduce(isend, irecv, 5, MPIU_PETSCLOGDOUBLE, MPI_MAX, PetscObjectComm((PetscObject)matin)));

1645:     info->nz_used      = irecv[0];
1646:     info->nz_allocated = irecv[1];
1647:     info->nz_unneeded  = irecv[2];
1648:     info->memory       = irecv[3];
1649:     info->mallocs      = irecv[4];
1650:   } else if (flag == MAT_GLOBAL_SUM) {
1651:     PetscCallMPI(MPIU_Allreduce(isend, irecv, 5, MPIU_PETSCLOGDOUBLE, MPI_SUM, PetscObjectComm((PetscObject)matin)));

1653:     info->nz_used      = irecv[0];
1654:     info->nz_allocated = irecv[1];
1655:     info->nz_unneeded  = irecv[2];
1656:     info->memory       = irecv[3];
1657:     info->mallocs      = irecv[4];
1658:   }
1659:   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1660:   info->fill_ratio_needed = 0;
1661:   info->factor_mallocs    = 0;
1662:   PetscFunctionReturn(PETSC_SUCCESS);
1663: }

1665: PetscErrorCode MatSetOption_MPIAIJ(Mat A, MatOption op, PetscBool flg)
1666: {
1667:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

1669:   PetscFunctionBegin;
1670:   switch (op) {
1671:   case MAT_NEW_NONZERO_LOCATIONS:
1672:   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1673:   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1674:   case MAT_KEEP_NONZERO_PATTERN:
1675:   case MAT_NEW_NONZERO_LOCATION_ERR:
1676:   case MAT_USE_INODES:
1677:   case MAT_IGNORE_ZERO_ENTRIES:
1678:   case MAT_FORM_EXPLICIT_TRANSPOSE:
1679:     MatCheckPreallocated(A, 1);
1680:     PetscCall(MatSetOption(a->A, op, flg));
1681:     PetscCall(MatSetOption(a->B, op, flg));
1682:     break;
1683:   case MAT_ROW_ORIENTED:
1684:     MatCheckPreallocated(A, 1);
1685:     a->roworiented = flg;

1687:     PetscCall(MatSetOption(a->A, op, flg));
1688:     PetscCall(MatSetOption(a->B, op, flg));
1689:     break;
1690:   case MAT_IGNORE_OFF_PROC_ENTRIES:
1691:     a->donotstash = flg;
1692:     break;
1693:   /* Symmetry flags are handled directly by MatSetOption() and they don't affect preallocation */
1694:   case MAT_SPD:
1695:   case MAT_SYMMETRIC:
1696:   case MAT_STRUCTURALLY_SYMMETRIC:
1697:   case MAT_HERMITIAN:
1698:   case MAT_SYMMETRY_ETERNAL:
1699:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
1700:   case MAT_SPD_ETERNAL:
1701:     /* if the diagonal matrix is square it inherits some of the properties above */
1702:     if (a->A && A->rmap->n == A->cmap->n) PetscCall(MatSetOption(a->A, op, flg));
1703:     break;
1704:   case MAT_SUBMAT_SINGLEIS:
1705:     A->submat_singleis = flg;
1706:     break;
1707:   default:
1708:     break;
1709:   }
1710:   PetscFunctionReturn(PETSC_SUCCESS);
1711: }

1713: PetscErrorCode MatGetRow_MPIAIJ(Mat matin, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
1714: {
1715:   Mat_MPIAIJ  *mat = (Mat_MPIAIJ *)matin->data;
1716:   PetscScalar *vworkA, *vworkB, **pvA, **pvB, *v_p;
1717:   PetscInt     i, *cworkA, *cworkB, **pcA, **pcB, cstart = matin->cmap->rstart;
1718:   PetscInt     nztot, nzA, nzB, lrow, rstart = matin->rmap->rstart, rend = matin->rmap->rend;
1719:   PetscInt    *cmap, *idx_p;

1721:   PetscFunctionBegin;
1722:   PetscCheck(!mat->getrowactive, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Already active");
1723:   mat->getrowactive = PETSC_TRUE;

1725:   if (!mat->rowvalues && (idx || v)) {
1726:     /*
1727:         allocate enough space to hold information from the longest row.
1728:     */
1729:     Mat_SeqAIJ *Aa = (Mat_SeqAIJ *)mat->A->data, *Ba = (Mat_SeqAIJ *)mat->B->data;
1730:     PetscInt    max = 1, tmp;
1731:     for (i = 0; i < matin->rmap->n; i++) {
1732:       tmp = Aa->i[i + 1] - Aa->i[i] + Ba->i[i + 1] - Ba->i[i];
1733:       if (max < tmp) max = tmp;
1734:     }
1735:     PetscCall(PetscMalloc2(max, &mat->rowvalues, max, &mat->rowindices));
1736:   }

1738:   PetscCheck(row >= rstart && row < rend, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only local rows");
1739:   lrow = row - rstart;

1741:   pvA = &vworkA;
1742:   pcA = &cworkA;
1743:   pvB = &vworkB;
1744:   pcB = &cworkB;
1745:   if (!v) {
1746:     pvA = NULL;
1747:     pvB = NULL;
1748:   }
1749:   if (!idx) {
1750:     pcA = NULL;
1751:     if (!v) pcB = NULL;
1752:   }
1753:   PetscCall((*mat->A->ops->getrow)(mat->A, lrow, &nzA, pcA, pvA));
1754:   PetscCall((*mat->B->ops->getrow)(mat->B, lrow, &nzB, pcB, pvB));
1755:   nztot = nzA + nzB;

1757:   cmap = mat->garray;
1758:   if (v || idx) {
1759:     if (nztot) {
1760:       /* Sort by increasing column numbers, assuming A and B already sorted */
1761:       PetscInt imark = -1;
1762:       if (v) {
1763:         *v = v_p = mat->rowvalues;
1764:         for (i = 0; i < nzB; i++) {
1765:           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1766:           else break;
1767:         }
1768:         imark = i;
1769:         for (i = 0; i < nzA; i++) v_p[imark + i] = vworkA[i];
1770:         for (i = imark; i < nzB; i++) v_p[nzA + i] = vworkB[i];
1771:       }
1772:       if (idx) {
1773:         *idx = idx_p = mat->rowindices;
1774:         if (imark > -1) {
1775:           for (i = 0; i < imark; i++) idx_p[i] = cmap[cworkB[i]];
1776:         } else {
1777:           for (i = 0; i < nzB; i++) {
1778:             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1779:             else break;
1780:           }
1781:           imark = i;
1782:         }
1783:         for (i = 0; i < nzA; i++) idx_p[imark + i] = cstart + cworkA[i];
1784:         for (i = imark; i < nzB; i++) idx_p[nzA + i] = cmap[cworkB[i]];
1785:       }
1786:     } else {
1787:       if (idx) *idx = NULL;
1788:       if (v) *v = NULL;
1789:     }
1790:   }
1791:   *nz = nztot;
1792:   PetscCall((*mat->A->ops->restorerow)(mat->A, lrow, &nzA, pcA, pvA));
1793:   PetscCall((*mat->B->ops->restorerow)(mat->B, lrow, &nzB, pcB, pvB));
1794:   PetscFunctionReturn(PETSC_SUCCESS);
1795: }

1797: PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
1798: {
1799:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

1801:   PetscFunctionBegin;
1802:   PetscCheck(aij->getrowactive, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "MatGetRow() must be called first");
1803:   aij->getrowactive = PETSC_FALSE;
1804:   PetscFunctionReturn(PETSC_SUCCESS);
1805: }

1807: static PetscErrorCode MatNorm_MPIAIJ(Mat mat, NormType type, PetscReal *norm)
1808: {
1809:   Mat_MPIAIJ      *aij  = (Mat_MPIAIJ *)mat->data;
1810:   Mat_SeqAIJ      *amat = (Mat_SeqAIJ *)aij->A->data, *bmat = (Mat_SeqAIJ *)aij->B->data;
1811:   PetscInt         i, j, cstart = mat->cmap->rstart;
1812:   PetscReal        sum = 0.0;
1813:   const MatScalar *v, *amata, *bmata;

1815:   PetscFunctionBegin;
1816:   if (aij->size == 1) {
1817:     PetscCall(MatNorm(aij->A, type, norm));
1818:   } else {
1819:     PetscCall(MatSeqAIJGetArrayRead(aij->A, &amata));
1820:     PetscCall(MatSeqAIJGetArrayRead(aij->B, &bmata));
1821:     if (type == NORM_FROBENIUS) {
1822:       v = amata;
1823:       for (i = 0; i < amat->nz; i++) {
1824:         sum += PetscRealPart(PetscConj(*v) * (*v));
1825:         v++;
1826:       }
1827:       v = bmata;
1828:       for (i = 0; i < bmat->nz; i++) {
1829:         sum += PetscRealPart(PetscConj(*v) * (*v));
1830:         v++;
1831:       }
1832:       PetscCallMPI(MPIU_Allreduce(&sum, norm, 1, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)mat)));
1833:       *norm = PetscSqrtReal(*norm);
1834:       PetscCall(PetscLogFlops(2.0 * amat->nz + 2.0 * bmat->nz));
1835:     } else if (type == NORM_1) { /* max column norm */
1836:       PetscReal *tmp;
1837:       PetscInt  *jj, *garray = aij->garray;
1838:       PetscCall(PetscCalloc1(mat->cmap->N + 1, &tmp));
1839:       *norm = 0.0;
1840:       v     = amata;
1841:       jj    = amat->j;
1842:       for (j = 0; j < amat->nz; j++) {
1843:         tmp[cstart + *jj++] += PetscAbsScalar(*v);
1844:         v++;
1845:       }
1846:       v  = bmata;
1847:       jj = bmat->j;
1848:       for (j = 0; j < bmat->nz; j++) {
1849:         tmp[garray[*jj++]] += PetscAbsScalar(*v);
1850:         v++;
1851:       }
1852:       PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, tmp, mat->cmap->N, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)mat)));
1853:       for (j = 0; j < mat->cmap->N; j++) {
1854:         if (tmp[j] > *norm) *norm = tmp[j];
1855:       }
1856:       PetscCall(PetscFree(tmp));
1857:       PetscCall(PetscLogFlops(PetscMax(amat->nz + bmat->nz - 1, 0)));
1858:     } else if (type == NORM_INFINITY) { /* max row norm */
1859:       PetscReal ntemp = 0.0;
1860:       for (j = 0; j < aij->A->rmap->n; j++) {
1861:         v   = PetscSafePointerPlusOffset(amata, amat->i[j]);
1862:         sum = 0.0;
1863:         for (i = 0; i < amat->i[j + 1] - amat->i[j]; i++) {
1864:           sum += PetscAbsScalar(*v);
1865:           v++;
1866:         }
1867:         v = PetscSafePointerPlusOffset(bmata, bmat->i[j]);
1868:         for (i = 0; i < bmat->i[j + 1] - bmat->i[j]; i++) {
1869:           sum += PetscAbsScalar(*v);
1870:           v++;
1871:         }
1872:         if (sum > ntemp) ntemp = sum;
1873:       }
1874:       PetscCallMPI(MPIU_Allreduce(&ntemp, norm, 1, MPIU_REAL, MPIU_MAX, PetscObjectComm((PetscObject)mat)));
1875:       PetscCall(PetscLogFlops(PetscMax(amat->nz + bmat->nz - 1, 0)));
1876:     } else SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "No support for two norm");
1877:     PetscCall(MatSeqAIJRestoreArrayRead(aij->A, &amata));
1878:     PetscCall(MatSeqAIJRestoreArrayRead(aij->B, &bmata));
1879:   }
1880:   PetscFunctionReturn(PETSC_SUCCESS);
1881: }

1883: static PetscErrorCode MatTranspose_MPIAIJ(Mat A, MatReuse reuse, Mat *matout)
1884: {
1885:   Mat_MPIAIJ      *a    = (Mat_MPIAIJ *)A->data, *b;
1886:   Mat_SeqAIJ      *Aloc = (Mat_SeqAIJ *)a->A->data, *Bloc = (Mat_SeqAIJ *)a->B->data, *sub_B_diag;
1887:   PetscInt         M = A->rmap->N, N = A->cmap->N, ma, na, mb, nb, row, *cols, *cols_tmp, *B_diag_ilen, i, ncol, A_diag_ncol;
1888:   const PetscInt  *ai, *aj, *bi, *bj, *B_diag_i;
1889:   Mat              B, A_diag, *B_diag;
1890:   const MatScalar *pbv, *bv;

1892:   PetscFunctionBegin;
1893:   if (reuse == MAT_REUSE_MATRIX) PetscCall(MatTransposeCheckNonzeroState_Private(A, *matout));
1894:   ma = A->rmap->n;
1895:   na = A->cmap->n;
1896:   mb = a->B->rmap->n;
1897:   nb = a->B->cmap->n;
1898:   ai = Aloc->i;
1899:   aj = Aloc->j;
1900:   bi = Bloc->i;
1901:   bj = Bloc->j;
1902:   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1903:     PetscInt            *d_nnz, *g_nnz, *o_nnz;
1904:     PetscSFNode         *oloc;
1905:     PETSC_UNUSED PetscSF sf;

1907:     PetscCall(PetscMalloc4(na, &d_nnz, na, &o_nnz, nb, &g_nnz, nb, &oloc));
1908:     /* compute d_nnz for preallocation */
1909:     PetscCall(PetscArrayzero(d_nnz, na));
1910:     for (i = 0; i < ai[ma]; i++) d_nnz[aj[i]]++;
1911:     /* compute local off-diagonal contributions */
1912:     PetscCall(PetscArrayzero(g_nnz, nb));
1913:     for (i = 0; i < bi[ma]; i++) g_nnz[bj[i]]++;
1914:     /* map those to global */
1915:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &sf));
1916:     PetscCall(PetscSFSetGraphLayout(sf, A->cmap, nb, NULL, PETSC_USE_POINTER, a->garray));
1917:     PetscCall(PetscSFSetFromOptions(sf));
1918:     PetscCall(PetscArrayzero(o_nnz, na));
1919:     PetscCall(PetscSFReduceBegin(sf, MPIU_INT, g_nnz, o_nnz, MPI_SUM));
1920:     PetscCall(PetscSFReduceEnd(sf, MPIU_INT, g_nnz, o_nnz, MPI_SUM));
1921:     PetscCall(PetscSFDestroy(&sf));

1923:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
1924:     PetscCall(MatSetSizes(B, A->cmap->n, A->rmap->n, N, M));
1925:     PetscCall(MatSetBlockSizes(B, A->cmap->bs, A->rmap->bs));
1926:     PetscCall(MatSetType(B, ((PetscObject)A)->type_name));
1927:     PetscCall(MatMPIAIJSetPreallocation(B, 0, d_nnz, 0, o_nnz));
1928:     PetscCall(PetscFree4(d_nnz, o_nnz, g_nnz, oloc));
1929:   } else {
1930:     B = *matout;
1931:     PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
1932:   }

1934:   b           = (Mat_MPIAIJ *)B->data;
1935:   A_diag      = a->A;
1936:   B_diag      = &b->A;
1937:   sub_B_diag  = (Mat_SeqAIJ *)(*B_diag)->data;
1938:   A_diag_ncol = A_diag->cmap->N;
1939:   B_diag_ilen = sub_B_diag->ilen;
1940:   B_diag_i    = sub_B_diag->i;

1942:   /* Set ilen for diagonal of B */
1943:   for (i = 0; i < A_diag_ncol; i++) B_diag_ilen[i] = B_diag_i[i + 1] - B_diag_i[i];

1945:   /* Transpose the diagonal part of the matrix. In contrast to the off-diagonal part, this can be done
1946:   very quickly (=without using MatSetValues), because all writes are local. */
1947:   PetscCall(MatTransposeSetPrecursor(A_diag, *B_diag));
1948:   PetscCall(MatTranspose(A_diag, MAT_REUSE_MATRIX, B_diag));

1950:   /* copy over the B part */
1951:   PetscCall(PetscMalloc1(bi[mb], &cols));
1952:   PetscCall(MatSeqAIJGetArrayRead(a->B, &bv));
1953:   pbv = bv;
1954:   row = A->rmap->rstart;
1955:   for (i = 0; i < bi[mb]; i++) cols[i] = a->garray[bj[i]];
1956:   cols_tmp = cols;
1957:   for (i = 0; i < mb; i++) {
1958:     ncol = bi[i + 1] - bi[i];
1959:     PetscCall(MatSetValues(B, ncol, cols_tmp, 1, &row, pbv, INSERT_VALUES));
1960:     row++;
1961:     if (pbv) pbv += ncol;
1962:     if (cols_tmp) cols_tmp += ncol;
1963:   }
1964:   PetscCall(PetscFree(cols));
1965:   PetscCall(MatSeqAIJRestoreArrayRead(a->B, &bv));

1967:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
1968:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
1969:   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX) {
1970:     *matout = B;
1971:   } else {
1972:     PetscCall(MatHeaderMerge(A, &B));
1973:   }
1974:   PetscFunctionReturn(PETSC_SUCCESS);
1975: }

1977: static PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat, Vec ll, Vec rr)
1978: {
1979:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;
1980:   Mat         a = aij->A, b = aij->B;
1981:   PetscInt    s1, s2, s3;

1983:   PetscFunctionBegin;
1984:   PetscCall(MatGetLocalSize(mat, &s2, &s3));
1985:   if (rr) {
1986:     PetscCall(VecGetLocalSize(rr, &s1));
1987:     PetscCheck(s1 == s3, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "right vector non-conforming local size");
1988:     /* Overlap communication with computation. */
1989:     PetscCall(VecScatterBegin(aij->Mvctx, rr, aij->lvec, INSERT_VALUES, SCATTER_FORWARD));
1990:   }
1991:   if (ll) {
1992:     PetscCall(VecGetLocalSize(ll, &s1));
1993:     PetscCheck(s1 == s2, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "left vector non-conforming local size");
1994:     PetscUseTypeMethod(b, diagonalscale, ll, NULL);
1995:   }
1996:   /* scale  the diagonal block */
1997:   PetscUseTypeMethod(a, diagonalscale, ll, rr);

1999:   if (rr) {
2000:     /* Do a scatter end and then right scale the off-diagonal block */
2001:     PetscCall(VecScatterEnd(aij->Mvctx, rr, aij->lvec, INSERT_VALUES, SCATTER_FORWARD));
2002:     PetscUseTypeMethod(b, diagonalscale, NULL, aij->lvec);
2003:   }
2004:   PetscFunctionReturn(PETSC_SUCCESS);
2005: }

2007: static PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2008: {
2009:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2011:   PetscFunctionBegin;
2012:   PetscCall(MatSetUnfactored(a->A));
2013:   PetscFunctionReturn(PETSC_SUCCESS);
2014: }

2016: static PetscErrorCode MatEqual_MPIAIJ(Mat A, Mat B, PetscBool *flag)
2017: {
2018:   Mat_MPIAIJ *matB = (Mat_MPIAIJ *)B->data, *matA = (Mat_MPIAIJ *)A->data;
2019:   Mat         a, b, c, d;
2020:   PetscBool   flg;

2022:   PetscFunctionBegin;
2023:   a = matA->A;
2024:   b = matA->B;
2025:   c = matB->A;
2026:   d = matB->B;

2028:   PetscCall(MatEqual(a, c, &flg));
2029:   if (flg) PetscCall(MatEqual(b, d, &flg));
2030:   PetscCallMPI(MPIU_Allreduce(&flg, flag, 1, MPIU_BOOL, MPI_LAND, PetscObjectComm((PetscObject)A)));
2031:   PetscFunctionReturn(PETSC_SUCCESS);
2032: }

2034: static PetscErrorCode MatCopy_MPIAIJ(Mat A, Mat B, MatStructure str)
2035: {
2036:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
2037:   Mat_MPIAIJ *b = (Mat_MPIAIJ *)B->data;

2039:   PetscFunctionBegin;
2040:   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2041:   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2042:     /* because of the column compression in the off-processor part of the matrix a->B,
2043:        the number of columns in a->B and b->B may be different, hence we cannot call
2044:        the MatCopy() directly on the two parts. If need be, we can provide a more
2045:        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2046:        then copying the submatrices */
2047:     PetscCall(MatCopy_Basic(A, B, str));
2048:   } else {
2049:     PetscCall(MatCopy(a->A, b->A, str));
2050:     PetscCall(MatCopy(a->B, b->B, str));
2051:   }
2052:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
2053:   PetscFunctionReturn(PETSC_SUCCESS);
2054: }

2056: /*
2057:    Computes the number of nonzeros per row needed for preallocation when X and Y
2058:    have different nonzero structure.
2059: */
2060: PetscErrorCode MatAXPYGetPreallocation_MPIX_private(PetscInt m, const PetscInt *xi, const PetscInt *xj, const PetscInt *xltog, const PetscInt *yi, const PetscInt *yj, const PetscInt *yltog, PetscInt *nnz)
2061: {
2062:   PetscInt i, j, k, nzx, nzy;

2064:   PetscFunctionBegin;
2065:   /* Set the number of nonzeros in the new matrix */
2066:   for (i = 0; i < m; i++) {
2067:     const PetscInt *xjj = PetscSafePointerPlusOffset(xj, xi[i]), *yjj = PetscSafePointerPlusOffset(yj, yi[i]);
2068:     nzx    = xi[i + 1] - xi[i];
2069:     nzy    = yi[i + 1] - yi[i];
2070:     nnz[i] = 0;
2071:     for (j = 0, k = 0; j < nzx; j++) {                                /* Point in X */
2072:       for (; k < nzy && yltog[yjj[k]] < xltog[xjj[j]]; k++) nnz[i]++; /* Catch up to X */
2073:       if (k < nzy && yltog[yjj[k]] == xltog[xjj[j]]) k++;             /* Skip duplicate */
2074:       nnz[i]++;
2075:     }
2076:     for (; k < nzy; k++) nnz[i]++;
2077:   }
2078:   PetscFunctionReturn(PETSC_SUCCESS);
2079: }

2081: /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2082: static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y, const PetscInt *yltog, Mat X, const PetscInt *xltog, PetscInt *nnz)
2083: {
2084:   PetscInt    m = Y->rmap->N;
2085:   Mat_SeqAIJ *x = (Mat_SeqAIJ *)X->data;
2086:   Mat_SeqAIJ *y = (Mat_SeqAIJ *)Y->data;

2088:   PetscFunctionBegin;
2089:   PetscCall(MatAXPYGetPreallocation_MPIX_private(m, x->i, x->j, xltog, y->i, y->j, yltog, nnz));
2090:   PetscFunctionReturn(PETSC_SUCCESS);
2091: }

2093: static PetscErrorCode MatAXPY_MPIAIJ(Mat Y, PetscScalar a, Mat X, MatStructure str)
2094: {
2095:   Mat_MPIAIJ *xx = (Mat_MPIAIJ *)X->data, *yy = (Mat_MPIAIJ *)Y->data;

2097:   PetscFunctionBegin;
2098:   if (str == SAME_NONZERO_PATTERN) {
2099:     PetscCall(MatAXPY(yy->A, a, xx->A, str));
2100:     PetscCall(MatAXPY(yy->B, a, xx->B, str));
2101:   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
2102:     PetscCall(MatAXPY_Basic(Y, a, X, str));
2103:   } else {
2104:     Mat       B;
2105:     PetscInt *nnz_d, *nnz_o;

2107:     PetscCall(PetscMalloc1(yy->A->rmap->N, &nnz_d));
2108:     PetscCall(PetscMalloc1(yy->B->rmap->N, &nnz_o));
2109:     PetscCall(MatCreate(PetscObjectComm((PetscObject)Y), &B));
2110:     PetscCall(PetscObjectSetName((PetscObject)B, ((PetscObject)Y)->name));
2111:     PetscCall(MatSetLayouts(B, Y->rmap, Y->cmap));
2112:     PetscCall(MatSetType(B, ((PetscObject)Y)->type_name));
2113:     PetscCall(MatAXPYGetPreallocation_SeqAIJ(yy->A, xx->A, nnz_d));
2114:     PetscCall(MatAXPYGetPreallocation_MPIAIJ(yy->B, yy->garray, xx->B, xx->garray, nnz_o));
2115:     PetscCall(MatMPIAIJSetPreallocation(B, 0, nnz_d, 0, nnz_o));
2116:     PetscCall(MatAXPY_BasicWithPreallocation(B, Y, a, X, str));
2117:     PetscCall(MatHeaderMerge(Y, &B));
2118:     PetscCall(PetscFree(nnz_d));
2119:     PetscCall(PetscFree(nnz_o));
2120:   }
2121:   PetscFunctionReturn(PETSC_SUCCESS);
2122: }

2124: PETSC_INTERN PetscErrorCode MatConjugate_SeqAIJ(Mat);

2126: static PetscErrorCode MatConjugate_MPIAIJ(Mat mat)
2127: {
2128:   PetscFunctionBegin;
2129:   if (PetscDefined(USE_COMPLEX)) {
2130:     Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

2132:     PetscCall(MatConjugate_SeqAIJ(aij->A));
2133:     PetscCall(MatConjugate_SeqAIJ(aij->B));
2134:   }
2135:   PetscFunctionReturn(PETSC_SUCCESS);
2136: }

2138: static PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2139: {
2140:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2142:   PetscFunctionBegin;
2143:   PetscCall(MatRealPart(a->A));
2144:   PetscCall(MatRealPart(a->B));
2145:   PetscFunctionReturn(PETSC_SUCCESS);
2146: }

2148: static PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2149: {
2150:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2152:   PetscFunctionBegin;
2153:   PetscCall(MatImaginaryPart(a->A));
2154:   PetscCall(MatImaginaryPart(a->B));
2155:   PetscFunctionReturn(PETSC_SUCCESS);
2156: }

2158: static PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2159: {
2160:   Mat_MPIAIJ        *a = (Mat_MPIAIJ *)A->data;
2161:   PetscInt           i, *idxb = NULL, m = A->rmap->n;
2162:   PetscScalar       *vv;
2163:   Vec                vB, vA;
2164:   const PetscScalar *va, *vb;

2166:   PetscFunctionBegin;
2167:   PetscCall(MatCreateVecs(a->A, NULL, &vA));
2168:   PetscCall(MatGetRowMaxAbs(a->A, vA, idx));

2170:   PetscCall(VecGetArrayRead(vA, &va));
2171:   if (idx) {
2172:     for (i = 0; i < m; i++) {
2173:       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2174:     }
2175:   }

2177:   PetscCall(MatCreateVecs(a->B, NULL, &vB));
2178:   PetscCall(PetscMalloc1(m, &idxb));
2179:   PetscCall(MatGetRowMaxAbs(a->B, vB, idxb));

2181:   PetscCall(VecGetArrayWrite(v, &vv));
2182:   PetscCall(VecGetArrayRead(vB, &vb));
2183:   for (i = 0; i < m; i++) {
2184:     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2185:       vv[i] = vb[i];
2186:       if (idx) idx[i] = a->garray[idxb[i]];
2187:     } else {
2188:       vv[i] = va[i];
2189:       if (idx && PetscAbsScalar(va[i]) == PetscAbsScalar(vb[i]) && idxb[i] != -1 && idx[i] > a->garray[idxb[i]]) idx[i] = a->garray[idxb[i]];
2190:     }
2191:   }
2192:   PetscCall(VecRestoreArrayWrite(v, &vv));
2193:   PetscCall(VecRestoreArrayRead(vA, &va));
2194:   PetscCall(VecRestoreArrayRead(vB, &vb));
2195:   PetscCall(PetscFree(idxb));
2196:   PetscCall(VecDestroy(&vA));
2197:   PetscCall(VecDestroy(&vB));
2198:   PetscFunctionReturn(PETSC_SUCCESS);
2199: }

2201: static PetscErrorCode MatGetRowSumAbs_MPIAIJ(Mat A, Vec v)
2202: {
2203:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
2204:   Vec         vB, vA;

2206:   PetscFunctionBegin;
2207:   PetscCall(MatCreateVecs(a->A, NULL, &vA));
2208:   PetscCall(MatGetRowSumAbs(a->A, vA));
2209:   PetscCall(MatCreateVecs(a->B, NULL, &vB));
2210:   PetscCall(MatGetRowSumAbs(a->B, vB));
2211:   PetscCall(VecAXPY(vA, 1.0, vB));
2212:   PetscCall(VecDestroy(&vB));
2213:   PetscCall(VecCopy(vA, v));
2214:   PetscCall(VecDestroy(&vA));
2215:   PetscFunctionReturn(PETSC_SUCCESS);
2216: }

2218: static PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2219: {
2220:   Mat_MPIAIJ        *mat = (Mat_MPIAIJ *)A->data;
2221:   PetscInt           m = A->rmap->n, n = A->cmap->n;
2222:   PetscInt           cstart = A->cmap->rstart, cend = A->cmap->rend;
2223:   PetscInt          *cmap = mat->garray;
2224:   PetscInt          *diagIdx, *offdiagIdx;
2225:   Vec                diagV, offdiagV;
2226:   PetscScalar       *a, *diagA, *offdiagA;
2227:   const PetscScalar *ba, *bav;
2228:   PetscInt           r, j, col, ncols, *bi, *bj;
2229:   Mat                B = mat->B;
2230:   Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;

2232:   PetscFunctionBegin;
2233:   /* When a process holds entire A and other processes have no entry */
2234:   if (A->cmap->N == n) {
2235:     PetscCall(VecGetArrayWrite(v, &diagA));
2236:     PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, 1, m, diagA, &diagV));
2237:     PetscCall(MatGetRowMinAbs(mat->A, diagV, idx));
2238:     PetscCall(VecDestroy(&diagV));
2239:     PetscCall(VecRestoreArrayWrite(v, &diagA));
2240:     PetscFunctionReturn(PETSC_SUCCESS);
2241:   } else if (n == 0) {
2242:     if (m) {
2243:       PetscCall(VecGetArrayWrite(v, &a));
2244:       for (r = 0; r < m; r++) {
2245:         a[r] = 0.0;
2246:         if (idx) idx[r] = -1;
2247:       }
2248:       PetscCall(VecRestoreArrayWrite(v, &a));
2249:     }
2250:     PetscFunctionReturn(PETSC_SUCCESS);
2251:   }

2253:   PetscCall(PetscMalloc2(m, &diagIdx, m, &offdiagIdx));
2254:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &diagV));
2255:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &offdiagV));
2256:   PetscCall(MatGetRowMinAbs(mat->A, diagV, diagIdx));

2258:   /* Get offdiagIdx[] for implicit 0.0 */
2259:   PetscCall(MatSeqAIJGetArrayRead(B, &bav));
2260:   ba = bav;
2261:   bi = b->i;
2262:   bj = b->j;
2263:   PetscCall(VecGetArrayWrite(offdiagV, &offdiagA));
2264:   for (r = 0; r < m; r++) {
2265:     ncols = bi[r + 1] - bi[r];
2266:     if (ncols == A->cmap->N - n) { /* Brow is dense */
2267:       offdiagA[r]   = *ba;
2268:       offdiagIdx[r] = cmap[0];
2269:     } else { /* Brow is sparse so already KNOW maximum is 0.0 or higher */
2270:       offdiagA[r] = 0.0;

2272:       /* Find first hole in the cmap */
2273:       for (j = 0; j < ncols; j++) {
2274:         col = cmap[bj[j]]; /* global column number = cmap[B column number] */
2275:         if (col > j && j < cstart) {
2276:           offdiagIdx[r] = j; /* global column number of first implicit 0.0 */
2277:           break;
2278:         } else if (col > j + n && j >= cstart) {
2279:           offdiagIdx[r] = j + n; /* global column number of first implicit 0.0 */
2280:           break;
2281:         }
2282:       }
2283:       if (j == ncols && ncols < A->cmap->N - n) {
2284:         /* a hole is outside compressed Bcols */
2285:         if (ncols == 0) {
2286:           if (cstart) {
2287:             offdiagIdx[r] = 0;
2288:           } else offdiagIdx[r] = cend;
2289:         } else { /* ncols > 0 */
2290:           offdiagIdx[r] = cmap[ncols - 1] + 1;
2291:           if (offdiagIdx[r] == cstart) offdiagIdx[r] += n;
2292:         }
2293:       }
2294:     }

2296:     for (j = 0; j < ncols; j++) {
2297:       if (PetscAbsScalar(offdiagA[r]) > PetscAbsScalar(*ba)) {
2298:         offdiagA[r]   = *ba;
2299:         offdiagIdx[r] = cmap[*bj];
2300:       }
2301:       ba++;
2302:       bj++;
2303:     }
2304:   }

2306:   PetscCall(VecGetArrayWrite(v, &a));
2307:   PetscCall(VecGetArrayRead(diagV, (const PetscScalar **)&diagA));
2308:   for (r = 0; r < m; ++r) {
2309:     if (PetscAbsScalar(diagA[r]) < PetscAbsScalar(offdiagA[r])) {
2310:       a[r] = diagA[r];
2311:       if (idx) idx[r] = cstart + diagIdx[r];
2312:     } else if (PetscAbsScalar(diagA[r]) == PetscAbsScalar(offdiagA[r])) {
2313:       a[r] = diagA[r];
2314:       if (idx) {
2315:         if (cstart + diagIdx[r] <= offdiagIdx[r]) {
2316:           idx[r] = cstart + diagIdx[r];
2317:         } else idx[r] = offdiagIdx[r];
2318:       }
2319:     } else {
2320:       a[r] = offdiagA[r];
2321:       if (idx) idx[r] = offdiagIdx[r];
2322:     }
2323:   }
2324:   PetscCall(MatSeqAIJRestoreArrayRead(B, &bav));
2325:   PetscCall(VecRestoreArrayWrite(v, &a));
2326:   PetscCall(VecRestoreArrayRead(diagV, (const PetscScalar **)&diagA));
2327:   PetscCall(VecRestoreArrayWrite(offdiagV, &offdiagA));
2328:   PetscCall(VecDestroy(&diagV));
2329:   PetscCall(VecDestroy(&offdiagV));
2330:   PetscCall(PetscFree2(diagIdx, offdiagIdx));
2331:   PetscFunctionReturn(PETSC_SUCCESS);
2332: }

2334: static PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2335: {
2336:   Mat_MPIAIJ        *mat = (Mat_MPIAIJ *)A->data;
2337:   PetscInt           m = A->rmap->n, n = A->cmap->n;
2338:   PetscInt           cstart = A->cmap->rstart, cend = A->cmap->rend;
2339:   PetscInt          *cmap = mat->garray;
2340:   PetscInt          *diagIdx, *offdiagIdx;
2341:   Vec                diagV, offdiagV;
2342:   PetscScalar       *a, *diagA, *offdiagA;
2343:   const PetscScalar *ba, *bav;
2344:   PetscInt           r, j, col, ncols, *bi, *bj;
2345:   Mat                B = mat->B;
2346:   Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;

2348:   PetscFunctionBegin;
2349:   /* When a process holds entire A and other processes have no entry */
2350:   if (A->cmap->N == n) {
2351:     PetscCall(VecGetArrayWrite(v, &diagA));
2352:     PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, 1, m, diagA, &diagV));
2353:     PetscCall(MatGetRowMin(mat->A, diagV, idx));
2354:     PetscCall(VecDestroy(&diagV));
2355:     PetscCall(VecRestoreArrayWrite(v, &diagA));
2356:     PetscFunctionReturn(PETSC_SUCCESS);
2357:   } else if (n == 0) {
2358:     if (m) {
2359:       PetscCall(VecGetArrayWrite(v, &a));
2360:       for (r = 0; r < m; r++) {
2361:         a[r] = PETSC_MAX_REAL;
2362:         if (idx) idx[r] = -1;
2363:       }
2364:       PetscCall(VecRestoreArrayWrite(v, &a));
2365:     }
2366:     PetscFunctionReturn(PETSC_SUCCESS);
2367:   }

2369:   PetscCall(PetscCalloc2(m, &diagIdx, m, &offdiagIdx));
2370:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &diagV));
2371:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &offdiagV));
2372:   PetscCall(MatGetRowMin(mat->A, diagV, diagIdx));

2374:   /* Get offdiagIdx[] for implicit 0.0 */
2375:   PetscCall(MatSeqAIJGetArrayRead(B, &bav));
2376:   ba = bav;
2377:   bi = b->i;
2378:   bj = b->j;
2379:   PetscCall(VecGetArrayWrite(offdiagV, &offdiagA));
2380:   for (r = 0; r < m; r++) {
2381:     ncols = bi[r + 1] - bi[r];
2382:     if (ncols == A->cmap->N - n) { /* Brow is dense */
2383:       offdiagA[r]   = *ba;
2384:       offdiagIdx[r] = cmap[0];
2385:     } else { /* Brow is sparse so already KNOW maximum is 0.0 or higher */
2386:       offdiagA[r] = 0.0;

2388:       /* Find first hole in the cmap */
2389:       for (j = 0; j < ncols; j++) {
2390:         col = cmap[bj[j]]; /* global column number = cmap[B column number] */
2391:         if (col > j && j < cstart) {
2392:           offdiagIdx[r] = j; /* global column number of first implicit 0.0 */
2393:           break;
2394:         } else if (col > j + n && j >= cstart) {
2395:           offdiagIdx[r] = j + n; /* global column number of first implicit 0.0 */
2396:           break;
2397:         }
2398:       }
2399:       if (j == ncols && ncols < A->cmap->N - n) {
2400:         /* a hole is outside compressed Bcols */
2401:         if (ncols == 0) {
2402:           if (cstart) {
2403:             offdiagIdx[r] = 0;
2404:           } else offdiagIdx[r] = cend;
2405:         } else { /* ncols > 0 */
2406:           offdiagIdx[r] = cmap[ncols - 1] + 1;
2407:           if (offdiagIdx[r] == cstart) offdiagIdx[r] += n;
2408:         }
2409:       }
2410:     }

2412:     for (j = 0; j < ncols; j++) {
2413:       if (PetscRealPart(offdiagA[r]) > PetscRealPart(*ba)) {
2414:         offdiagA[r]   = *ba;
2415:         offdiagIdx[r] = cmap[*bj];
2416:       }
2417:       ba++;
2418:       bj++;
2419:     }
2420:   }

2422:   PetscCall(VecGetArrayWrite(v, &a));
2423:   PetscCall(VecGetArrayRead(diagV, (const PetscScalar **)&diagA));
2424:   for (r = 0; r < m; ++r) {
2425:     if (PetscRealPart(diagA[r]) < PetscRealPart(offdiagA[r])) {
2426:       a[r] = diagA[r];
2427:       if (idx) idx[r] = cstart + diagIdx[r];
2428:     } else if (PetscRealPart(diagA[r]) == PetscRealPart(offdiagA[r])) {
2429:       a[r] = diagA[r];
2430:       if (idx) {
2431:         if (cstart + diagIdx[r] <= offdiagIdx[r]) {
2432:           idx[r] = cstart + diagIdx[r];
2433:         } else idx[r] = offdiagIdx[r];
2434:       }
2435:     } else {
2436:       a[r] = offdiagA[r];
2437:       if (idx) idx[r] = offdiagIdx[r];
2438:     }
2439:   }
2440:   PetscCall(MatSeqAIJRestoreArrayRead(B, &bav));
2441:   PetscCall(VecRestoreArrayWrite(v, &a));
2442:   PetscCall(VecRestoreArrayRead(diagV, (const PetscScalar **)&diagA));
2443:   PetscCall(VecRestoreArrayWrite(offdiagV, &offdiagA));
2444:   PetscCall(VecDestroy(&diagV));
2445:   PetscCall(VecDestroy(&offdiagV));
2446:   PetscCall(PetscFree2(diagIdx, offdiagIdx));
2447:   PetscFunctionReturn(PETSC_SUCCESS);
2448: }

2450: static PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2451: {
2452:   Mat_MPIAIJ        *mat = (Mat_MPIAIJ *)A->data;
2453:   PetscInt           m = A->rmap->n, n = A->cmap->n;
2454:   PetscInt           cstart = A->cmap->rstart, cend = A->cmap->rend;
2455:   PetscInt          *cmap = mat->garray;
2456:   PetscInt          *diagIdx, *offdiagIdx;
2457:   Vec                diagV, offdiagV;
2458:   PetscScalar       *a, *diagA, *offdiagA;
2459:   const PetscScalar *ba, *bav;
2460:   PetscInt           r, j, col, ncols, *bi, *bj;
2461:   Mat                B = mat->B;
2462:   Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;

2464:   PetscFunctionBegin;
2465:   /* When a process holds entire A and other processes have no entry */
2466:   if (A->cmap->N == n) {
2467:     PetscCall(VecGetArrayWrite(v, &diagA));
2468:     PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, 1, m, diagA, &diagV));
2469:     PetscCall(MatGetRowMax(mat->A, diagV, idx));
2470:     PetscCall(VecDestroy(&diagV));
2471:     PetscCall(VecRestoreArrayWrite(v, &diagA));
2472:     PetscFunctionReturn(PETSC_SUCCESS);
2473:   } else if (n == 0) {
2474:     if (m) {
2475:       PetscCall(VecGetArrayWrite(v, &a));
2476:       for (r = 0; r < m; r++) {
2477:         a[r] = PETSC_MIN_REAL;
2478:         if (idx) idx[r] = -1;
2479:       }
2480:       PetscCall(VecRestoreArrayWrite(v, &a));
2481:     }
2482:     PetscFunctionReturn(PETSC_SUCCESS);
2483:   }

2485:   PetscCall(PetscMalloc2(m, &diagIdx, m, &offdiagIdx));
2486:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &diagV));
2487:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &offdiagV));
2488:   PetscCall(MatGetRowMax(mat->A, diagV, diagIdx));

2490:   /* Get offdiagIdx[] for implicit 0.0 */
2491:   PetscCall(MatSeqAIJGetArrayRead(B, &bav));
2492:   ba = bav;
2493:   bi = b->i;
2494:   bj = b->j;
2495:   PetscCall(VecGetArrayWrite(offdiagV, &offdiagA));
2496:   for (r = 0; r < m; r++) {
2497:     ncols = bi[r + 1] - bi[r];
2498:     if (ncols == A->cmap->N - n) { /* Brow is dense */
2499:       offdiagA[r]   = *ba;
2500:       offdiagIdx[r] = cmap[0];
2501:     } else { /* Brow is sparse so already KNOW maximum is 0.0 or higher */
2502:       offdiagA[r] = 0.0;

2504:       /* Find first hole in the cmap */
2505:       for (j = 0; j < ncols; j++) {
2506:         col = cmap[bj[j]]; /* global column number = cmap[B column number] */
2507:         if (col > j && j < cstart) {
2508:           offdiagIdx[r] = j; /* global column number of first implicit 0.0 */
2509:           break;
2510:         } else if (col > j + n && j >= cstart) {
2511:           offdiagIdx[r] = j + n; /* global column number of first implicit 0.0 */
2512:           break;
2513:         }
2514:       }
2515:       if (j == ncols && ncols < A->cmap->N - n) {
2516:         /* a hole is outside compressed Bcols */
2517:         if (ncols == 0) {
2518:           if (cstart) {
2519:             offdiagIdx[r] = 0;
2520:           } else offdiagIdx[r] = cend;
2521:         } else { /* ncols > 0 */
2522:           offdiagIdx[r] = cmap[ncols - 1] + 1;
2523:           if (offdiagIdx[r] == cstart) offdiagIdx[r] += n;
2524:         }
2525:       }
2526:     }

2528:     for (j = 0; j < ncols; j++) {
2529:       if (PetscRealPart(offdiagA[r]) < PetscRealPart(*ba)) {
2530:         offdiagA[r]   = *ba;
2531:         offdiagIdx[r] = cmap[*bj];
2532:       }
2533:       ba++;
2534:       bj++;
2535:     }
2536:   }

2538:   PetscCall(VecGetArrayWrite(v, &a));
2539:   PetscCall(VecGetArrayRead(diagV, (const PetscScalar **)&diagA));
2540:   for (r = 0; r < m; ++r) {
2541:     if (PetscRealPart(diagA[r]) > PetscRealPart(offdiagA[r])) {
2542:       a[r] = diagA[r];
2543:       if (idx) idx[r] = cstart + diagIdx[r];
2544:     } else if (PetscRealPart(diagA[r]) == PetscRealPart(offdiagA[r])) {
2545:       a[r] = diagA[r];
2546:       if (idx) {
2547:         if (cstart + diagIdx[r] <= offdiagIdx[r]) {
2548:           idx[r] = cstart + diagIdx[r];
2549:         } else idx[r] = offdiagIdx[r];
2550:       }
2551:     } else {
2552:       a[r] = offdiagA[r];
2553:       if (idx) idx[r] = offdiagIdx[r];
2554:     }
2555:   }
2556:   PetscCall(MatSeqAIJRestoreArrayRead(B, &bav));
2557:   PetscCall(VecRestoreArrayWrite(v, &a));
2558:   PetscCall(VecRestoreArrayRead(diagV, (const PetscScalar **)&diagA));
2559:   PetscCall(VecRestoreArrayWrite(offdiagV, &offdiagA));
2560:   PetscCall(VecDestroy(&diagV));
2561:   PetscCall(VecDestroy(&offdiagV));
2562:   PetscCall(PetscFree2(diagIdx, offdiagIdx));
2563:   PetscFunctionReturn(PETSC_SUCCESS);
2564: }

2566: PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat, Mat *newmat)
2567: {
2568:   Mat *dummy;

2570:   PetscFunctionBegin;
2571:   PetscCall(MatCreateSubMatrix_MPIAIJ_All(mat, MAT_DO_NOT_GET_VALUES, MAT_INITIAL_MATRIX, &dummy));
2572:   *newmat = *dummy;
2573:   PetscCall(PetscFree(dummy));
2574:   PetscFunctionReturn(PETSC_SUCCESS);
2575: }

2577: static PetscErrorCode MatInvertBlockDiagonal_MPIAIJ(Mat A, const PetscScalar **values)
2578: {
2579:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2581:   PetscFunctionBegin;
2582:   PetscCall(MatInvertBlockDiagonal(a->A, values));
2583:   A->factorerrortype = a->A->factorerrortype;
2584:   PetscFunctionReturn(PETSC_SUCCESS);
2585: }

2587: static PetscErrorCode MatSetRandom_MPIAIJ(Mat x, PetscRandom rctx)
2588: {
2589:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)x->data;

2591:   PetscFunctionBegin;
2592:   PetscCheck(x->assembled || x->preallocated, PetscObjectComm((PetscObject)x), PETSC_ERR_ARG_WRONGSTATE, "MatSetRandom on an unassembled and unpreallocated MATMPIAIJ is not allowed");
2593:   PetscCall(MatSetRandom(aij->A, rctx));
2594:   if (x->assembled) {
2595:     PetscCall(MatSetRandom(aij->B, rctx));
2596:   } else {
2597:     PetscCall(MatSetRandomSkipColumnRange_SeqAIJ_Private(aij->B, x->cmap->rstart, x->cmap->rend, rctx));
2598:   }
2599:   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
2600:   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
2601:   PetscFunctionReturn(PETSC_SUCCESS);
2602: }

2604: static PetscErrorCode MatMPIAIJSetUseScalableIncreaseOverlap_MPIAIJ(Mat A, PetscBool sc)
2605: {
2606:   PetscFunctionBegin;
2607:   if (sc) A->ops->increaseoverlap = MatIncreaseOverlap_MPIAIJ_Scalable;
2608:   else A->ops->increaseoverlap = MatIncreaseOverlap_MPIAIJ;
2609:   PetscFunctionReturn(PETSC_SUCCESS);
2610: }

2612: /*@
2613:   MatMPIAIJGetNumberNonzeros - gets the number of nonzeros in the matrix on this MPI rank

2615:   Not Collective

2617:   Input Parameter:
2618: . A - the matrix

2620:   Output Parameter:
2621: . nz - the number of nonzeros

2623:   Level: advanced

2625: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`
2626: @*/
2627: PetscErrorCode MatMPIAIJGetNumberNonzeros(Mat A, PetscCount *nz)
2628: {
2629:   Mat_MPIAIJ *maij = (Mat_MPIAIJ *)A->data;
2630:   Mat_SeqAIJ *aaij = (Mat_SeqAIJ *)maij->A->data, *baij = (Mat_SeqAIJ *)maij->B->data;
2631:   PetscBool   isaij;

2633:   PetscFunctionBegin;
2634:   PetscCall(PetscObjectBaseTypeCompare((PetscObject)A, MATMPIAIJ, &isaij));
2635:   PetscCheck(isaij, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Not for type %s", ((PetscObject)A)->type_name);
2636:   *nz = aaij->i[A->rmap->n] + baij->i[A->rmap->n];
2637:   PetscFunctionReturn(PETSC_SUCCESS);
2638: }

2640: /*@
2641:   MatMPIAIJSetUseScalableIncreaseOverlap - Determine if the matrix uses a scalable algorithm to compute the overlap

2643:   Collective

2645:   Input Parameters:
2646: + A  - the matrix
2647: - sc - `PETSC_TRUE` indicates use the scalable algorithm (default is not to use the scalable algorithm)

2649:   Level: advanced

2651: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`
2652: @*/
2653: PetscErrorCode MatMPIAIJSetUseScalableIncreaseOverlap(Mat A, PetscBool sc)
2654: {
2655:   PetscFunctionBegin;
2656:   PetscTryMethod(A, "MatMPIAIJSetUseScalableIncreaseOverlap_C", (Mat, PetscBool), (A, sc));
2657:   PetscFunctionReturn(PETSC_SUCCESS);
2658: }

2660: PetscErrorCode MatSetFromOptions_MPIAIJ(Mat A, PetscOptionItems PetscOptionsObject)
2661: {
2662:   PetscBool sc = PETSC_FALSE, flg;

2664:   PetscFunctionBegin;
2665:   PetscOptionsHeadBegin(PetscOptionsObject, "MPIAIJ options");
2666:   if (A->ops->increaseoverlap == MatIncreaseOverlap_MPIAIJ_Scalable) sc = PETSC_TRUE;
2667:   PetscCall(PetscOptionsBool("-mat_increase_overlap_scalable", "Use a scalable algorithm to compute the overlap", "MatIncreaseOverlap", sc, &sc, &flg));
2668:   if (flg) PetscCall(MatMPIAIJSetUseScalableIncreaseOverlap(A, sc));
2669:   PetscOptionsHeadEnd();
2670:   PetscFunctionReturn(PETSC_SUCCESS);
2671: }

2673: static PetscErrorCode MatShift_MPIAIJ(Mat Y, PetscScalar a)
2674: {
2675:   Mat_MPIAIJ *maij = (Mat_MPIAIJ *)Y->data;
2676:   Mat_SeqAIJ *aij  = (Mat_SeqAIJ *)maij->A->data;

2678:   PetscFunctionBegin;
2679:   if (!Y->preallocated) {
2680:     PetscCall(MatMPIAIJSetPreallocation(Y, 1, NULL, 0, NULL));
2681:   } else if (!aij->nz) { /* It does not matter if diagonals of Y only partially lie in maij->A. We just need an estimated preallocation. */
2682:     PetscInt nonew = aij->nonew;
2683:     PetscCall(MatSeqAIJSetPreallocation(maij->A, 1, NULL));
2684:     aij->nonew = nonew;
2685:   }
2686:   PetscCall(MatShift_Basic(Y, a));
2687:   PetscFunctionReturn(PETSC_SUCCESS);
2688: }

2690: static PetscErrorCode MatMissingDiagonal_MPIAIJ(Mat A, PetscBool *missing, PetscInt *d)
2691: {
2692:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2694:   PetscFunctionBegin;
2695:   PetscCheck(A->rmap->n == A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only works for square matrices");
2696:   PetscCall(MatMissingDiagonal(a->A, missing, d));
2697:   if (d) {
2698:     PetscInt rstart;
2699:     PetscCall(MatGetOwnershipRange(A, &rstart, NULL));
2700:     *d += rstart;
2701:   }
2702:   PetscFunctionReturn(PETSC_SUCCESS);
2703: }

2705: static PetscErrorCode MatInvertVariableBlockDiagonal_MPIAIJ(Mat A, PetscInt nblocks, const PetscInt *bsizes, PetscScalar *diag)
2706: {
2707:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2709:   PetscFunctionBegin;
2710:   PetscCall(MatInvertVariableBlockDiagonal(a->A, nblocks, bsizes, diag));
2711:   PetscFunctionReturn(PETSC_SUCCESS);
2712: }

2714: static PetscErrorCode MatEliminateZeros_MPIAIJ(Mat A, PetscBool keep)
2715: {
2716:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;

2718:   PetscFunctionBegin;
2719:   PetscCall(MatEliminateZeros_SeqAIJ(a->A, keep));        // possibly keep zero diagonal coefficients
2720:   PetscCall(MatEliminateZeros_SeqAIJ(a->B, PETSC_FALSE)); // never keep zero diagonal coefficients
2721:   PetscFunctionReturn(PETSC_SUCCESS);
2722: }

2724: static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2725:                                        MatGetRow_MPIAIJ,
2726:                                        MatRestoreRow_MPIAIJ,
2727:                                        MatMult_MPIAIJ,
2728:                                        /* 4*/ MatMultAdd_MPIAIJ,
2729:                                        MatMultTranspose_MPIAIJ,
2730:                                        MatMultTransposeAdd_MPIAIJ,
2731:                                        NULL,
2732:                                        NULL,
2733:                                        NULL,
2734:                                        /*10*/ NULL,
2735:                                        NULL,
2736:                                        NULL,
2737:                                        MatSOR_MPIAIJ,
2738:                                        MatTranspose_MPIAIJ,
2739:                                        /*15*/ MatGetInfo_MPIAIJ,
2740:                                        MatEqual_MPIAIJ,
2741:                                        MatGetDiagonal_MPIAIJ,
2742:                                        MatDiagonalScale_MPIAIJ,
2743:                                        MatNorm_MPIAIJ,
2744:                                        /*20*/ MatAssemblyBegin_MPIAIJ,
2745:                                        MatAssemblyEnd_MPIAIJ,
2746:                                        MatSetOption_MPIAIJ,
2747:                                        MatZeroEntries_MPIAIJ,
2748:                                        /*24*/ MatZeroRows_MPIAIJ,
2749:                                        NULL,
2750:                                        NULL,
2751:                                        NULL,
2752:                                        NULL,
2753:                                        /*29*/ MatSetUp_MPI_Hash,
2754:                                        NULL,
2755:                                        NULL,
2756:                                        MatGetDiagonalBlock_MPIAIJ,
2757:                                        NULL,
2758:                                        /*34*/ MatDuplicate_MPIAIJ,
2759:                                        NULL,
2760:                                        NULL,
2761:                                        NULL,
2762:                                        NULL,
2763:                                        /*39*/ MatAXPY_MPIAIJ,
2764:                                        MatCreateSubMatrices_MPIAIJ,
2765:                                        MatIncreaseOverlap_MPIAIJ,
2766:                                        MatGetValues_MPIAIJ,
2767:                                        MatCopy_MPIAIJ,
2768:                                        /*44*/ MatGetRowMax_MPIAIJ,
2769:                                        MatScale_MPIAIJ,
2770:                                        MatShift_MPIAIJ,
2771:                                        MatDiagonalSet_MPIAIJ,
2772:                                        MatZeroRowsColumns_MPIAIJ,
2773:                                        /*49*/ MatSetRandom_MPIAIJ,
2774:                                        MatGetRowIJ_MPIAIJ,
2775:                                        MatRestoreRowIJ_MPIAIJ,
2776:                                        NULL,
2777:                                        NULL,
2778:                                        /*54*/ MatFDColoringCreate_MPIXAIJ,
2779:                                        NULL,
2780:                                        MatSetUnfactored_MPIAIJ,
2781:                                        MatPermute_MPIAIJ,
2782:                                        NULL,
2783:                                        /*59*/ MatCreateSubMatrix_MPIAIJ,
2784:                                        MatDestroy_MPIAIJ,
2785:                                        MatView_MPIAIJ,
2786:                                        NULL,
2787:                                        NULL,
2788:                                        /*64*/ NULL,
2789:                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
2790:                                        NULL,
2791:                                        NULL,
2792:                                        NULL,
2793:                                        /*69*/ MatGetRowMaxAbs_MPIAIJ,
2794:                                        MatGetRowMinAbs_MPIAIJ,
2795:                                        NULL,
2796:                                        NULL,
2797:                                        NULL,
2798:                                        NULL,
2799:                                        /*75*/ MatFDColoringApply_AIJ,
2800:                                        MatSetFromOptions_MPIAIJ,
2801:                                        NULL,
2802:                                        NULL,
2803:                                        MatFindZeroDiagonals_MPIAIJ,
2804:                                        /*80*/ NULL,
2805:                                        NULL,
2806:                                        NULL,
2807:                                        /*83*/ MatLoad_MPIAIJ,
2808:                                        NULL,
2809:                                        NULL,
2810:                                        NULL,
2811:                                        NULL,
2812:                                        NULL,
2813:                                        /*89*/ NULL,
2814:                                        NULL,
2815:                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
2816:                                        NULL,
2817:                                        NULL,
2818:                                        /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
2819:                                        NULL,
2820:                                        NULL,
2821:                                        NULL,
2822:                                        MatBindToCPU_MPIAIJ,
2823:                                        /*99*/ MatProductSetFromOptions_MPIAIJ,
2824:                                        NULL,
2825:                                        NULL,
2826:                                        MatConjugate_MPIAIJ,
2827:                                        NULL,
2828:                                        /*104*/ MatSetValuesRow_MPIAIJ,
2829:                                        MatRealPart_MPIAIJ,
2830:                                        MatImaginaryPart_MPIAIJ,
2831:                                        NULL,
2832:                                        NULL,
2833:                                        /*109*/ NULL,
2834:                                        NULL,
2835:                                        MatGetRowMin_MPIAIJ,
2836:                                        NULL,
2837:                                        MatMissingDiagonal_MPIAIJ,
2838:                                        /*114*/ MatGetSeqNonzeroStructure_MPIAIJ,
2839:                                        NULL,
2840:                                        MatGetGhosts_MPIAIJ,
2841:                                        NULL,
2842:                                        NULL,
2843:                                        /*119*/ MatMultDiagonalBlock_MPIAIJ,
2844:                                        NULL,
2845:                                        NULL,
2846:                                        NULL,
2847:                                        MatGetMultiProcBlock_MPIAIJ,
2848:                                        /*124*/ MatFindNonzeroRows_MPIAIJ,
2849:                                        MatGetColumnReductions_MPIAIJ,
2850:                                        MatInvertBlockDiagonal_MPIAIJ,
2851:                                        MatInvertVariableBlockDiagonal_MPIAIJ,
2852:                                        MatCreateSubMatricesMPI_MPIAIJ,
2853:                                        /*129*/ NULL,
2854:                                        NULL,
2855:                                        NULL,
2856:                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
2857:                                        NULL,
2858:                                        /*134*/ NULL,
2859:                                        NULL,
2860:                                        NULL,
2861:                                        NULL,
2862:                                        NULL,
2863:                                        /*139*/ MatSetBlockSizes_MPIAIJ,
2864:                                        NULL,
2865:                                        NULL,
2866:                                        MatFDColoringSetUp_MPIXAIJ,
2867:                                        MatFindOffBlockDiagonalEntries_MPIAIJ,
2868:                                        MatCreateMPIMatConcatenateSeqMat_MPIAIJ,
2869:                                        /*145*/ NULL,
2870:                                        NULL,
2871:                                        NULL,
2872:                                        MatCreateGraph_Simple_AIJ,
2873:                                        NULL,
2874:                                        /*150*/ NULL,
2875:                                        MatEliminateZeros_MPIAIJ,
2876:                                        MatGetRowSumAbs_MPIAIJ,
2877:                                        NULL,
2878:                                        NULL,
2879:                                        /*155*/ NULL,
2880:                                        MatCopyHashToXAIJ_MPI_Hash};

2882: static PetscErrorCode MatStoreValues_MPIAIJ(Mat mat)
2883: {
2884:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

2886:   PetscFunctionBegin;
2887:   PetscCall(MatStoreValues(aij->A));
2888:   PetscCall(MatStoreValues(aij->B));
2889:   PetscFunctionReturn(PETSC_SUCCESS);
2890: }

2892: static PetscErrorCode MatRetrieveValues_MPIAIJ(Mat mat)
2893: {
2894:   Mat_MPIAIJ *aij = (Mat_MPIAIJ *)mat->data;

2896:   PetscFunctionBegin;
2897:   PetscCall(MatRetrieveValues(aij->A));
2898:   PetscCall(MatRetrieveValues(aij->B));
2899:   PetscFunctionReturn(PETSC_SUCCESS);
2900: }

2902: PetscErrorCode MatMPIAIJSetPreallocation_MPIAIJ(Mat B, PetscInt d_nz, const PetscInt d_nnz[], PetscInt o_nz, const PetscInt o_nnz[])
2903: {
2904:   Mat_MPIAIJ *b = (Mat_MPIAIJ *)B->data;
2905:   PetscMPIInt size;

2907:   PetscFunctionBegin;
2908:   if (B->hash_active) {
2909:     B->ops[0]      = b->cops;
2910:     B->hash_active = PETSC_FALSE;
2911:   }
2912:   PetscCall(PetscLayoutSetUp(B->rmap));
2913:   PetscCall(PetscLayoutSetUp(B->cmap));

2915: #if defined(PETSC_USE_CTABLE)
2916:   PetscCall(PetscHMapIDestroy(&b->colmap));
2917: #else
2918:   PetscCall(PetscFree(b->colmap));
2919: #endif
2920:   PetscCall(PetscFree(b->garray));
2921:   PetscCall(VecDestroy(&b->lvec));
2922:   PetscCall(VecScatterDestroy(&b->Mvctx));

2924:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)B), &size));

2926:   MatSeqXAIJGetOptions_Private(b->B);
2927:   PetscCall(MatDestroy(&b->B));
2928:   PetscCall(MatCreate(PETSC_COMM_SELF, &b->B));
2929:   PetscCall(MatSetSizes(b->B, B->rmap->n, size > 1 ? B->cmap->N : 0, B->rmap->n, size > 1 ? B->cmap->N : 0));
2930:   PetscCall(MatSetBlockSizesFromMats(b->B, B, B));
2931:   PetscCall(MatSetType(b->B, MATSEQAIJ));
2932:   MatSeqXAIJRestoreOptions_Private(b->B);

2934:   MatSeqXAIJGetOptions_Private(b->A);
2935:   PetscCall(MatDestroy(&b->A));
2936:   PetscCall(MatCreate(PETSC_COMM_SELF, &b->A));
2937:   PetscCall(MatSetSizes(b->A, B->rmap->n, B->cmap->n, B->rmap->n, B->cmap->n));
2938:   PetscCall(MatSetBlockSizesFromMats(b->A, B, B));
2939:   PetscCall(MatSetType(b->A, MATSEQAIJ));
2940:   MatSeqXAIJRestoreOptions_Private(b->A);

2942:   PetscCall(MatSeqAIJSetPreallocation(b->A, d_nz, d_nnz));
2943:   PetscCall(MatSeqAIJSetPreallocation(b->B, o_nz, o_nnz));
2944:   B->preallocated  = PETSC_TRUE;
2945:   B->was_assembled = PETSC_FALSE;
2946:   B->assembled     = PETSC_FALSE;
2947:   PetscFunctionReturn(PETSC_SUCCESS);
2948: }

2950: static PetscErrorCode MatResetPreallocation_MPIAIJ(Mat B)
2951: {
2952:   Mat_MPIAIJ *b = (Mat_MPIAIJ *)B->data;
2953:   PetscBool   ondiagreset, offdiagreset, memoryreset;

2955:   PetscFunctionBegin;
2957:   PetscCheck(B->insertmode == NOT_SET_VALUES, PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot reset preallocation after setting some values but not yet calling MatAssemblyBegin()/MatAssemblyEnd()");
2958:   if (B->num_ass == 0) PetscFunctionReturn(PETSC_SUCCESS);

2960:   PetscCall(MatResetPreallocation_SeqAIJ_Private(b->A, &ondiagreset));
2961:   PetscCall(MatResetPreallocation_SeqAIJ_Private(b->B, &offdiagreset));
2962:   memoryreset = (PetscBool)(ondiagreset || offdiagreset);
2963:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &memoryreset, 1, MPIU_BOOL, MPI_LOR, PetscObjectComm((PetscObject)B)));
2964:   if (!memoryreset) PetscFunctionReturn(PETSC_SUCCESS);

2966:   PetscCall(PetscLayoutSetUp(B->rmap));
2967:   PetscCall(PetscLayoutSetUp(B->cmap));
2968:   PetscCheck(B->assembled || B->was_assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Should not need to reset preallocation if the matrix was never assembled");
2969:   PetscCall(MatDisAssemble_MPIAIJ(B, PETSC_TRUE));
2970:   PetscCall(VecScatterDestroy(&b->Mvctx));

2972:   B->preallocated  = PETSC_TRUE;
2973:   B->was_assembled = PETSC_FALSE;
2974:   B->assembled     = PETSC_FALSE;
2975:   /* Log that the state of this object has changed; this will help guarantee that preconditioners get re-setup */
2976:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
2977:   PetscFunctionReturn(PETSC_SUCCESS);
2978: }

2980: PetscErrorCode MatDuplicate_MPIAIJ(Mat matin, MatDuplicateOption cpvalues, Mat *newmat)
2981: {
2982:   Mat         mat;
2983:   Mat_MPIAIJ *a, *oldmat = (Mat_MPIAIJ *)matin->data;

2985:   PetscFunctionBegin;
2986:   *newmat = NULL;
2987:   PetscCall(MatCreate(PetscObjectComm((PetscObject)matin), &mat));
2988:   PetscCall(MatSetSizes(mat, matin->rmap->n, matin->cmap->n, matin->rmap->N, matin->cmap->N));
2989:   PetscCall(MatSetBlockSizesFromMats(mat, matin, matin));
2990:   PetscCall(MatSetType(mat, ((PetscObject)matin)->type_name));
2991:   a = (Mat_MPIAIJ *)mat->data;

2993:   mat->factortype = matin->factortype;
2994:   mat->assembled  = matin->assembled;
2995:   mat->insertmode = NOT_SET_VALUES;

2997:   a->size         = oldmat->size;
2998:   a->rank         = oldmat->rank;
2999:   a->donotstash   = oldmat->donotstash;
3000:   a->roworiented  = oldmat->roworiented;
3001:   a->rowindices   = NULL;
3002:   a->rowvalues    = NULL;
3003:   a->getrowactive = PETSC_FALSE;

3005:   PetscCall(PetscLayoutReference(matin->rmap, &mat->rmap));
3006:   PetscCall(PetscLayoutReference(matin->cmap, &mat->cmap));
3007:   if (matin->hash_active) {
3008:     PetscCall(MatSetUp(mat));
3009:   } else {
3010:     mat->preallocated = matin->preallocated;
3011:     if (oldmat->colmap) {
3012: #if defined(PETSC_USE_CTABLE)
3013:       PetscCall(PetscHMapIDuplicate(oldmat->colmap, &a->colmap));
3014: #else
3015:       PetscCall(PetscMalloc1(mat->cmap->N, &a->colmap));
3016:       PetscCall(PetscArraycpy(a->colmap, oldmat->colmap, mat->cmap->N));
3017: #endif
3018:     } else a->colmap = NULL;
3019:     if (oldmat->garray) {
3020:       PetscInt len;
3021:       len = oldmat->B->cmap->n;
3022:       PetscCall(PetscMalloc1(len + 1, &a->garray));
3023:       if (len) PetscCall(PetscArraycpy(a->garray, oldmat->garray, len));
3024:     } else a->garray = NULL;

3026:     /* It may happen MatDuplicate is called with a non-assembled matrix
3027:       In fact, MatDuplicate only requires the matrix to be preallocated
3028:       This may happen inside a DMCreateMatrix_Shell */
3029:     if (oldmat->lvec) PetscCall(VecDuplicate(oldmat->lvec, &a->lvec));
3030:     if (oldmat->Mvctx) {
3031:       a->Mvctx = oldmat->Mvctx;
3032:       PetscCall(PetscObjectReference((PetscObject)oldmat->Mvctx));
3033:     }
3034:     PetscCall(MatDuplicate(oldmat->A, cpvalues, &a->A));
3035:     PetscCall(MatDuplicate(oldmat->B, cpvalues, &a->B));
3036:   }
3037:   PetscCall(PetscFunctionListDuplicate(((PetscObject)matin)->qlist, &((PetscObject)mat)->qlist));
3038:   *newmat = mat;
3039:   PetscFunctionReturn(PETSC_SUCCESS);
3040: }

3042: PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3043: {
3044:   PetscBool isbinary, ishdf5;

3046:   PetscFunctionBegin;
3049:   /* force binary viewer to load .info file if it has not yet done so */
3050:   PetscCall(PetscViewerSetUp(viewer));
3051:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
3052:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
3053:   if (isbinary) {
3054:     PetscCall(MatLoad_MPIAIJ_Binary(newMat, viewer));
3055:   } else if (ishdf5) {
3056: #if defined(PETSC_HAVE_HDF5)
3057:     PetscCall(MatLoad_AIJ_HDF5(newMat, viewer));
3058: #else
3059:     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "HDF5 not supported in this build.\nPlease reconfigure using --download-hdf5");
3060: #endif
3061:   } else {
3062:     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "Viewer type %s not yet supported for reading %s matrices", ((PetscObject)viewer)->type_name, ((PetscObject)newMat)->type_name);
3063:   }
3064:   PetscFunctionReturn(PETSC_SUCCESS);
3065: }

3067: PetscErrorCode MatLoad_MPIAIJ_Binary(Mat mat, PetscViewer viewer)
3068: {
3069:   PetscInt     header[4], M, N, m, nz, rows, cols, sum, i;
3070:   PetscInt    *rowidxs, *colidxs;
3071:   PetscScalar *matvals;

3073:   PetscFunctionBegin;
3074:   PetscCall(PetscViewerSetUp(viewer));

3076:   /* read in matrix header */
3077:   PetscCall(PetscViewerBinaryRead(viewer, header, 4, NULL, PETSC_INT));
3078:   PetscCheck(header[0] == MAT_FILE_CLASSID, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Not a matrix object in file");
3079:   M  = header[1];
3080:   N  = header[2];
3081:   nz = header[3];
3082:   PetscCheck(M >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix row size (%" PetscInt_FMT ") in file is negative", M);
3083:   PetscCheck(N >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix column size (%" PetscInt_FMT ") in file is negative", N);
3084:   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix stored in special format on disk, cannot load as MPIAIJ");

3086:   /* set block sizes from the viewer's .info file */
3087:   PetscCall(MatLoad_Binary_BlockSizes(mat, viewer));
3088:   /* set global sizes if not set already */
3089:   if (mat->rmap->N < 0) mat->rmap->N = M;
3090:   if (mat->cmap->N < 0) mat->cmap->N = N;
3091:   PetscCall(PetscLayoutSetUp(mat->rmap));
3092:   PetscCall(PetscLayoutSetUp(mat->cmap));

3094:   /* check if the matrix sizes are correct */
3095:   PetscCall(MatGetSize(mat, &rows, &cols));
3096:   PetscCheck(M == rows && N == cols, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix in file of different sizes (%" PetscInt_FMT ", %" PetscInt_FMT ") than the input matrix (%" PetscInt_FMT ", %" PetscInt_FMT ")", M, N, rows, cols);

3098:   /* read in row lengths and build row indices */
3099:   PetscCall(MatGetLocalSize(mat, &m, NULL));
3100:   PetscCall(PetscMalloc1(m + 1, &rowidxs));
3101:   PetscCall(PetscViewerBinaryReadAll(viewer, rowidxs + 1, m, PETSC_DECIDE, M, PETSC_INT));
3102:   rowidxs[0] = 0;
3103:   for (i = 0; i < m; i++) rowidxs[i + 1] += rowidxs[i];
3104:   if (nz != PETSC_INT_MAX) {
3105:     PetscCallMPI(MPIU_Allreduce(&rowidxs[m], &sum, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)viewer)));
3106:     PetscCheck(sum == nz, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Inconsistent matrix data in file: nonzeros = %" PetscInt_FMT ", sum-row-lengths = %" PetscInt_FMT, nz, sum);
3107:   }

3109:   /* read in column indices and matrix values */
3110:   PetscCall(PetscMalloc2(rowidxs[m], &colidxs, rowidxs[m], &matvals));
3111:   PetscCall(PetscViewerBinaryReadAll(viewer, colidxs, rowidxs[m], PETSC_DETERMINE, PETSC_DETERMINE, PETSC_INT));
3112:   PetscCall(PetscViewerBinaryReadAll(viewer, matvals, rowidxs[m], PETSC_DETERMINE, PETSC_DETERMINE, PETSC_SCALAR));
3113:   /* store matrix indices and values */
3114:   PetscCall(MatMPIAIJSetPreallocationCSR(mat, rowidxs, colidxs, matvals));
3115:   PetscCall(PetscFree(rowidxs));
3116:   PetscCall(PetscFree2(colidxs, matvals));
3117:   PetscFunctionReturn(PETSC_SUCCESS);
3118: }

3120: /* Not scalable because of ISAllGather() unless getting all columns. */
3121: static PetscErrorCode ISGetSeqIS_Private(Mat mat, IS iscol, IS *isseq)
3122: {
3123:   IS          iscol_local;
3124:   PetscBool   isstride;
3125:   PetscMPIInt gisstride = 0;

3127:   PetscFunctionBegin;
3128:   /* check if we are grabbing all columns*/
3129:   PetscCall(PetscObjectTypeCompare((PetscObject)iscol, ISSTRIDE, &isstride));

3131:   if (isstride) {
3132:     PetscInt start, len, mstart, mlen;
3133:     PetscCall(ISStrideGetInfo(iscol, &start, NULL));
3134:     PetscCall(ISGetLocalSize(iscol, &len));
3135:     PetscCall(MatGetOwnershipRangeColumn(mat, &mstart, &mlen));
3136:     if (mstart == start && mlen - mstart == len) gisstride = 1;
3137:   }

3139:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &gisstride, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
3140:   if (gisstride) {
3141:     PetscInt N;
3142:     PetscCall(MatGetSize(mat, NULL, &N));
3143:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol_local));
3144:     PetscCall(ISSetIdentity(iscol_local));
3145:     PetscCall(PetscInfo(mat, "Optimizing for obtaining all columns of the matrix; skipping ISAllGather()\n"));
3146:   } else {
3147:     PetscInt cbs;
3148:     PetscCall(ISGetBlockSize(iscol, &cbs));
3149:     PetscCall(ISAllGather(iscol, &iscol_local));
3150:     PetscCall(ISSetBlockSize(iscol_local, cbs));
3151:   }

3153:   *isseq = iscol_local;
3154:   PetscFunctionReturn(PETSC_SUCCESS);
3155: }

3157: /*
3158:  Used by MatCreateSubMatrix_MPIAIJ_SameRowColDist() to avoid ISAllGather() and global size of iscol_local
3159:  (see MatCreateSubMatrix_MPIAIJ_nonscalable)

3161:  Input Parameters:
3162: +   mat - matrix
3163: .   isrow - parallel row index set; its local indices are a subset of local columns of `mat`,
3164:            i.e., mat->rstart <= isrow[i] < mat->rend
3165: -   iscol - parallel column index set; its local indices are a subset of local columns of `mat`,
3166:            i.e., mat->cstart <= iscol[i] < mat->cend

3168:  Output Parameters:
3169: +   isrow_d - sequential row index set for retrieving mat->A
3170: .   iscol_d - sequential  column index set for retrieving mat->A
3171: .   iscol_o - sequential column index set for retrieving mat->B
3172: -   garray - column map; garray[i] indicates global location of iscol_o[i] in `iscol`
3173:  */
3174: static PetscErrorCode ISGetSeqIS_SameColDist_Private(Mat mat, IS isrow, IS iscol, IS *isrow_d, IS *iscol_d, IS *iscol_o, PetscInt *garray[])
3175: {
3176:   Vec             x, cmap;
3177:   const PetscInt *is_idx;
3178:   PetscScalar    *xarray, *cmaparray;
3179:   PetscInt        ncols, isstart, *idx, m, rstart, *cmap1, count;
3180:   Mat_MPIAIJ     *a    = (Mat_MPIAIJ *)mat->data;
3181:   Mat             B    = a->B;
3182:   Vec             lvec = a->lvec, lcmap;
3183:   PetscInt        i, cstart, cend, Bn = B->cmap->N;
3184:   MPI_Comm        comm;
3185:   VecScatter      Mvctx = a->Mvctx;

3187:   PetscFunctionBegin;
3188:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
3189:   PetscCall(ISGetLocalSize(iscol, &ncols));

3191:   /* (1) iscol is a sub-column vector of mat, pad it with '-1.' to form a full vector x */
3192:   PetscCall(MatCreateVecs(mat, &x, NULL));
3193:   PetscCall(VecSet(x, -1.0));
3194:   PetscCall(VecDuplicate(x, &cmap));
3195:   PetscCall(VecSet(cmap, -1.0));

3197:   /* Get start indices */
3198:   PetscCallMPI(MPI_Scan(&ncols, &isstart, 1, MPIU_INT, MPI_SUM, comm));
3199:   isstart -= ncols;
3200:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));

3202:   PetscCall(ISGetIndices(iscol, &is_idx));
3203:   PetscCall(VecGetArray(x, &xarray));
3204:   PetscCall(VecGetArray(cmap, &cmaparray));
3205:   PetscCall(PetscMalloc1(ncols, &idx));
3206:   for (i = 0; i < ncols; i++) {
3207:     xarray[is_idx[i] - cstart]    = (PetscScalar)is_idx[i];
3208:     cmaparray[is_idx[i] - cstart] = i + isstart;        /* global index of iscol[i] */
3209:     idx[i]                        = is_idx[i] - cstart; /* local index of iscol[i]  */
3210:   }
3211:   PetscCall(VecRestoreArray(x, &xarray));
3212:   PetscCall(VecRestoreArray(cmap, &cmaparray));
3213:   PetscCall(ISRestoreIndices(iscol, &is_idx));

3215:   /* Get iscol_d */
3216:   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, ncols, idx, PETSC_OWN_POINTER, iscol_d));
3217:   PetscCall(ISGetBlockSize(iscol, &i));
3218:   PetscCall(ISSetBlockSize(*iscol_d, i));

3220:   /* Get isrow_d */
3221:   PetscCall(ISGetLocalSize(isrow, &m));
3222:   rstart = mat->rmap->rstart;
3223:   PetscCall(PetscMalloc1(m, &idx));
3224:   PetscCall(ISGetIndices(isrow, &is_idx));
3225:   for (i = 0; i < m; i++) idx[i] = is_idx[i] - rstart;
3226:   PetscCall(ISRestoreIndices(isrow, &is_idx));

3228:   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m, idx, PETSC_OWN_POINTER, isrow_d));
3229:   PetscCall(ISGetBlockSize(isrow, &i));
3230:   PetscCall(ISSetBlockSize(*isrow_d, i));

3232:   /* (2) Scatter x and cmap using aij->Mvctx to get their off-process portions (see MatMult_MPIAIJ) */
3233:   PetscCall(VecScatterBegin(Mvctx, x, lvec, INSERT_VALUES, SCATTER_FORWARD));
3234:   PetscCall(VecScatterEnd(Mvctx, x, lvec, INSERT_VALUES, SCATTER_FORWARD));

3236:   PetscCall(VecDuplicate(lvec, &lcmap));

3238:   PetscCall(VecScatterBegin(Mvctx, cmap, lcmap, INSERT_VALUES, SCATTER_FORWARD));
3239:   PetscCall(VecScatterEnd(Mvctx, cmap, lcmap, INSERT_VALUES, SCATTER_FORWARD));

3241:   /* (3) create sequential iscol_o (a subset of iscol) and isgarray */
3242:   /* off-process column indices */
3243:   count = 0;
3244:   PetscCall(PetscMalloc1(Bn, &idx));
3245:   PetscCall(PetscMalloc1(Bn, &cmap1));

3247:   PetscCall(VecGetArray(lvec, &xarray));
3248:   PetscCall(VecGetArray(lcmap, &cmaparray));
3249:   for (i = 0; i < Bn; i++) {
3250:     if (PetscRealPart(xarray[i]) > -1.0) {
3251:       idx[count]   = i;                                     /* local column index in off-diagonal part B */
3252:       cmap1[count] = (PetscInt)PetscRealPart(cmaparray[i]); /* column index in submat */
3253:       count++;
3254:     }
3255:   }
3256:   PetscCall(VecRestoreArray(lvec, &xarray));
3257:   PetscCall(VecRestoreArray(lcmap, &cmaparray));

3259:   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, count, idx, PETSC_COPY_VALUES, iscol_o));
3260:   /* cannot ensure iscol_o has same blocksize as iscol! */

3262:   PetscCall(PetscFree(idx));
3263:   *garray = cmap1;

3265:   PetscCall(VecDestroy(&x));
3266:   PetscCall(VecDestroy(&cmap));
3267:   PetscCall(VecDestroy(&lcmap));
3268:   PetscFunctionReturn(PETSC_SUCCESS);
3269: }

3271: /* isrow and iscol have same processor distribution as mat, output *submat is a submatrix of local mat */
3272: PetscErrorCode MatCreateSubMatrix_MPIAIJ_SameRowColDist(Mat mat, IS isrow, IS iscol, MatReuse call, Mat *submat)
3273: {
3274:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)mat->data, *asub;
3275:   Mat         M = NULL;
3276:   MPI_Comm    comm;
3277:   IS          iscol_d, isrow_d, iscol_o;
3278:   Mat         Asub = NULL, Bsub = NULL;
3279:   PetscInt    n, count, M_size, N_size;

3281:   PetscFunctionBegin;
3282:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));

3284:   if (call == MAT_REUSE_MATRIX) {
3285:     /* Retrieve isrow_d, iscol_d and iscol_o from submat */
3286:     PetscCall(PetscObjectQuery((PetscObject)*submat, "isrow_d", (PetscObject *)&isrow_d));
3287:     PetscCheck(isrow_d, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "isrow_d passed in was not used before, cannot reuse");

3289:     PetscCall(PetscObjectQuery((PetscObject)*submat, "iscol_d", (PetscObject *)&iscol_d));
3290:     PetscCheck(iscol_d, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "iscol_d passed in was not used before, cannot reuse");

3292:     PetscCall(PetscObjectQuery((PetscObject)*submat, "iscol_o", (PetscObject *)&iscol_o));
3293:     PetscCheck(iscol_o, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "iscol_o passed in was not used before, cannot reuse");

3295:     /* Update diagonal and off-diagonal portions of submat */
3296:     asub = (Mat_MPIAIJ *)(*submat)->data;
3297:     PetscCall(MatCreateSubMatrix_SeqAIJ(a->A, isrow_d, iscol_d, PETSC_DECIDE, MAT_REUSE_MATRIX, &asub->A));
3298:     PetscCall(ISGetLocalSize(iscol_o, &n));
3299:     if (n) PetscCall(MatCreateSubMatrix_SeqAIJ(a->B, isrow_d, iscol_o, PETSC_DECIDE, MAT_REUSE_MATRIX, &asub->B));
3300:     PetscCall(MatAssemblyBegin(*submat, MAT_FINAL_ASSEMBLY));
3301:     PetscCall(MatAssemblyEnd(*submat, MAT_FINAL_ASSEMBLY));

3303:   } else { /* call == MAT_INITIAL_MATRIX) */
3304:     PetscInt *garray, *garray_compact;
3305:     PetscInt  BsubN;

3307:     /* Create isrow_d, iscol_d, iscol_o and isgarray (replace isgarray with array?) */
3308:     PetscCall(ISGetSeqIS_SameColDist_Private(mat, isrow, iscol, &isrow_d, &iscol_d, &iscol_o, &garray));

3310:     /* Create local submatrices Asub and Bsub */
3311:     PetscCall(MatCreateSubMatrix_SeqAIJ(a->A, isrow_d, iscol_d, PETSC_DECIDE, MAT_INITIAL_MATRIX, &Asub));
3312:     PetscCall(MatCreateSubMatrix_SeqAIJ(a->B, isrow_d, iscol_o, PETSC_DECIDE, MAT_INITIAL_MATRIX, &Bsub));

3314:     // Compact garray so its not of size Bn
3315:     PetscCall(ISGetSize(iscol_o, &count));
3316:     PetscCall(PetscMalloc1(count, &garray_compact));
3317:     PetscCall(PetscArraycpy(garray_compact, garray, count));

3319:     /* Create submatrix M */
3320:     PetscCall(ISGetSize(isrow, &M_size));
3321:     PetscCall(ISGetSize(iscol, &N_size));
3322:     PetscCall(MatCreateMPIAIJWithSeqAIJ(comm, M_size, N_size, Asub, Bsub, garray_compact, &M));

3324:     /* If Bsub has empty columns, compress iscol_o such that it will retrieve condensed Bsub from a->B during reuse */
3325:     asub = (Mat_MPIAIJ *)M->data;

3327:     PetscCall(ISGetLocalSize(iscol_o, &BsubN));
3328:     n = asub->B->cmap->N;
3329:     if (BsubN > n) {
3330:       /* This case can be tested using ~petsc/src/tao/bound/tutorials/runplate2_3 */
3331:       const PetscInt *idx;
3332:       PetscInt        i, j, *idx_new, *subgarray = asub->garray;
3333:       PetscCall(PetscInfo(M, "submatrix Bn %" PetscInt_FMT " != BsubN %" PetscInt_FMT ", update iscol_o\n", n, BsubN));

3335:       PetscCall(PetscMalloc1(n, &idx_new));
3336:       j = 0;
3337:       PetscCall(ISGetIndices(iscol_o, &idx));
3338:       for (i = 0; i < n; i++) {
3339:         if (j >= BsubN) break;
3340:         while (subgarray[i] > garray[j]) j++;

3342:         if (subgarray[i] == garray[j]) {
3343:           idx_new[i] = idx[j++];
3344:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "subgarray[%" PetscInt_FMT "]=%" PetscInt_FMT " cannot < garray[%" PetscInt_FMT "]=%" PetscInt_FMT, i, subgarray[i], j, garray[j]);
3345:       }
3346:       PetscCall(ISRestoreIndices(iscol_o, &idx));

3348:       PetscCall(ISDestroy(&iscol_o));
3349:       PetscCall(ISCreateGeneral(PETSC_COMM_SELF, n, idx_new, PETSC_OWN_POINTER, &iscol_o));

3351:     } else if (BsubN < n) {
3352:       SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Columns of Bsub (%" PetscInt_FMT ") cannot be smaller than B's (%" PetscInt_FMT ")", BsubN, asub->B->cmap->N);
3353:     }

3355:     PetscCall(PetscFree(garray));
3356:     *submat = M;

3358:     /* Save isrow_d, iscol_d and iscol_o used in processor for next request */
3359:     PetscCall(PetscObjectCompose((PetscObject)M, "isrow_d", (PetscObject)isrow_d));
3360:     PetscCall(ISDestroy(&isrow_d));

3362:     PetscCall(PetscObjectCompose((PetscObject)M, "iscol_d", (PetscObject)iscol_d));
3363:     PetscCall(ISDestroy(&iscol_d));

3365:     PetscCall(PetscObjectCompose((PetscObject)M, "iscol_o", (PetscObject)iscol_o));
3366:     PetscCall(ISDestroy(&iscol_o));
3367:   }
3368:   PetscFunctionReturn(PETSC_SUCCESS);
3369: }

3371: PetscErrorCode MatCreateSubMatrix_MPIAIJ(Mat mat, IS isrow, IS iscol, MatReuse call, Mat *newmat)
3372: {
3373:   IS        iscol_local = NULL, isrow_d;
3374:   PetscInt  csize;
3375:   PetscInt  n, i, j, start, end;
3376:   PetscBool sameRowDist = PETSC_FALSE, sameDist[2], tsameDist[2];
3377:   MPI_Comm  comm;

3379:   PetscFunctionBegin;
3380:   /* If isrow has same processor distribution as mat,
3381:      call MatCreateSubMatrix_MPIAIJ_SameRowDist() to avoid using a hash table with global size of iscol */
3382:   if (call == MAT_REUSE_MATRIX) {
3383:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "isrow_d", (PetscObject *)&isrow_d));
3384:     if (isrow_d) {
3385:       sameRowDist  = PETSC_TRUE;
3386:       tsameDist[1] = PETSC_TRUE; /* sameColDist */
3387:     } else {
3388:       PetscCall(PetscObjectQuery((PetscObject)*newmat, "SubIScol", (PetscObject *)&iscol_local));
3389:       if (iscol_local) {
3390:         sameRowDist  = PETSC_TRUE;
3391:         tsameDist[1] = PETSC_FALSE; /* !sameColDist */
3392:       }
3393:     }
3394:   } else {
3395:     /* Check if isrow has same processor distribution as mat */
3396:     sameDist[0] = PETSC_FALSE;
3397:     PetscCall(ISGetLocalSize(isrow, &n));
3398:     if (!n) {
3399:       sameDist[0] = PETSC_TRUE;
3400:     } else {
3401:       PetscCall(ISGetMinMax(isrow, &i, &j));
3402:       PetscCall(MatGetOwnershipRange(mat, &start, &end));
3403:       if (i >= start && j < end) sameDist[0] = PETSC_TRUE;
3404:     }

3406:     /* Check if iscol has same processor distribution as mat */
3407:     sameDist[1] = PETSC_FALSE;
3408:     PetscCall(ISGetLocalSize(iscol, &n));
3409:     if (!n) {
3410:       sameDist[1] = PETSC_TRUE;
3411:     } else {
3412:       PetscCall(ISGetMinMax(iscol, &i, &j));
3413:       PetscCall(MatGetOwnershipRangeColumn(mat, &start, &end));
3414:       if (i >= start && j < end) sameDist[1] = PETSC_TRUE;
3415:     }

3417:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
3418:     PetscCallMPI(MPIU_Allreduce(&sameDist, &tsameDist, 2, MPIU_BOOL, MPI_LAND, comm));
3419:     sameRowDist = tsameDist[0];
3420:   }

3422:   if (sameRowDist) {
3423:     if (tsameDist[1]) { /* sameRowDist & sameColDist */
3424:       /* isrow and iscol have same processor distribution as mat */
3425:       PetscCall(MatCreateSubMatrix_MPIAIJ_SameRowColDist(mat, isrow, iscol, call, newmat));
3426:       PetscFunctionReturn(PETSC_SUCCESS);
3427:     } else { /* sameRowDist */
3428:       /* isrow has same processor distribution as mat */
3429:       if (call == MAT_INITIAL_MATRIX) {
3430:         PetscBool sorted;
3431:         PetscCall(ISGetSeqIS_Private(mat, iscol, &iscol_local));
3432:         PetscCall(ISGetLocalSize(iscol_local, &n)); /* local size of iscol_local = global columns of newmat */
3433:         PetscCall(ISGetSize(iscol, &i));
3434:         PetscCheck(n == i, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "n %" PetscInt_FMT " != size of iscol %" PetscInt_FMT, n, i);

3436:         PetscCall(ISSorted(iscol_local, &sorted));
3437:         if (sorted) {
3438:           /* MatCreateSubMatrix_MPIAIJ_SameRowDist() requires iscol_local be sorted; it can have duplicate indices */
3439:           PetscCall(MatCreateSubMatrix_MPIAIJ_SameRowDist(mat, isrow, iscol, iscol_local, MAT_INITIAL_MATRIX, newmat));
3440:           PetscFunctionReturn(PETSC_SUCCESS);
3441:         }
3442:       } else { /* call == MAT_REUSE_MATRIX */
3443:         IS iscol_sub;
3444:         PetscCall(PetscObjectQuery((PetscObject)*newmat, "SubIScol", (PetscObject *)&iscol_sub));
3445:         if (iscol_sub) {
3446:           PetscCall(MatCreateSubMatrix_MPIAIJ_SameRowDist(mat, isrow, iscol, NULL, call, newmat));
3447:           PetscFunctionReturn(PETSC_SUCCESS);
3448:         }
3449:       }
3450:     }
3451:   }

3453:   /* General case: iscol -> iscol_local which has global size of iscol */
3454:   if (call == MAT_REUSE_MATRIX) {
3455:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "ISAllGather", (PetscObject *)&iscol_local));
3456:     PetscCheck(iscol_local, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Submatrix passed in was not used before, cannot reuse");
3457:   } else {
3458:     if (!iscol_local) PetscCall(ISGetSeqIS_Private(mat, iscol, &iscol_local));
3459:   }

3461:   PetscCall(ISGetLocalSize(iscol, &csize));
3462:   PetscCall(MatCreateSubMatrix_MPIAIJ_nonscalable(mat, isrow, iscol_local, csize, call, newmat));

3464:   if (call == MAT_INITIAL_MATRIX) {
3465:     PetscCall(PetscObjectCompose((PetscObject)*newmat, "ISAllGather", (PetscObject)iscol_local));
3466:     PetscCall(ISDestroy(&iscol_local));
3467:   }
3468:   PetscFunctionReturn(PETSC_SUCCESS);
3469: }

3471: /*@C
3472:   MatCreateMPIAIJWithSeqAIJ - creates a `MATMPIAIJ` matrix using `MATSEQAIJ` matrices that contain the "diagonal"
3473:   and "off-diagonal" part of the matrix in CSR format.

3475:   Collective

3477:   Input Parameters:
3478: + comm   - MPI communicator
3479: . M      - the global row size
3480: . N      - the global column size
3481: . A      - "diagonal" portion of matrix
3482: . B      - if garray is `NULL`, B should be the offdiag matrix using global col ids and of size N - if garray is not `NULL`, B should be the offdiag matrix using local col ids and of size garray
3483: - garray - either `NULL` or the global index of `B` columns. If not `NULL`, it should be allocated by `PetscMalloc1()` and will be owned by `mat` thereafter.

3485:   Output Parameter:
3486: . mat - the matrix, with input `A` as its local diagonal matrix

3488:   Level: advanced

3490:   Notes:
3491:   See `MatCreateAIJ()` for the definition of "diagonal" and "off-diagonal" portion of the matrix.

3493:   `A` and `B` becomes part of output mat. The user cannot use `A` and `B` anymore.

3495:   If `garray` is `NULL`, `B` will be compacted to use local indices. In this sense, `B`'s sparsity pattern (nonzerostate) will be changed. If `B` is a device matrix, we need to somehow also update
3496:   `B`'s copy on device.  We do so by increasing `B`'s nonzerostate. In use of `B` on device, device matrix types should detect this change (ref. internal routines `MatSeqAIJCUSPARSECopyToGPU()` or
3497:   `MatAssemblyEnd_SeqAIJKokkos()`) and will just destroy and then recreate the device copy of `B`. It is not optimal, but is easy to implement and less hacky. To avoid this overhead, try to compute `garray`
3498:   yourself, see algorithms in the private function `MatSetUpMultiply_MPIAIJ()`.

3500: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MATSEQAIJ`, `MatCreateMPIAIJWithSplitArrays()`
3501: @*/
3502: PetscErrorCode MatCreateMPIAIJWithSeqAIJ(MPI_Comm comm, PetscInt M, PetscInt N, Mat A, Mat B, PetscInt *garray, Mat *mat)
3503: {
3504:   PetscInt m, n;
3505:   MatType  mpi_mat_type;

3507:   PetscFunctionBegin;
3508:   PetscCall(MatCreate(comm, mat));
3509:   PetscCall(MatGetSize(A, &m, &n));
3510:   PetscCheck(m == B->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Am %" PetscInt_FMT " != Bm %" PetscInt_FMT, m, B->rmap->N);
3511:   PetscCheck(A->rmap->bs == B->rmap->bs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "A row bs %" PetscInt_FMT " != B row bs %" PetscInt_FMT, A->rmap->bs, B->rmap->bs);

3513:   PetscCall(MatSetSizes(*mat, m, n, M, N));
3514:   /* Determine the type of MPI matrix that should be created from the type of matrix A, which holds the "diagonal" portion. */
3515:   PetscCall(MatGetMPIMatType_Private(A, &mpi_mat_type));
3516:   PetscCall(MatSetType(*mat, mpi_mat_type));

3518:   PetscCall(MatSetBlockSizes(*mat, A->rmap->bs, A->cmap->bs));

3520:   PetscCall(PetscLayoutSetUp((*mat)->rmap));
3521:   PetscCall(PetscLayoutSetUp((*mat)->cmap));
3522:   if (!garray) {
3523:     const PetscScalar *ba;

3525:     B->nonzerostate++;
3526:     PetscCall(MatSeqAIJGetArrayRead(B, &ba)); /* Since we will destroy B's device copy, we need to make sure the host copy is up to date */
3527:     PetscCall(MatSeqAIJRestoreArrayRead(B, &ba));
3528:   }
3529:   PetscCall(MatSetMPIAIJWithSplitSeqAIJ(*mat, A, B, garray));
3530:   PetscFunctionReturn(PETSC_SUCCESS);
3531: }

3533: /*
3534:   MatSetMPIAIJWithSplitSeqAIJ - Set the diag and offdiag matrices of a `MATMPIAIJ` matrix.
3535:    It is similar to `MatCreateMPIAIJWithSplitArrays()`. This routine allows passing in
3536:    B with local indices and the correct size, along with the accompanying
3537:    garray, hence skipping compactification

3539:   Collective

3541:   Input Parameters:
3542: +  mat    - the MATMPIAIJ matrix, which should have its type and layout set, but should not have its diag, offdiag matrices set
3543: .  A      - the diag matrix using local col ids
3544: .  B      - if garray is `NULL`, B should be the offdiag matrix using global col ids and of size N - if garray is not `NULL`, B should be the offdiag matrix using local col ids and of size garray
3545: -  garray - either `NULL` or the global index of `B` columns

3547:   Output Parameter:
3548: .  mat   - the updated `MATMPIAIJ` matrix

3550:   Level: advanced

3552:   Notes:
3553:   See `MatCreateAIJ()` for the definition of "diagonal" and "off-diagonal" portion of the matrix.

3555:   `A` and `B` become part of output mat. The user cannot use `A` and `B` anymore.

3557: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MATSEQAIJ`, `MatCreateMPIAIJWithSplitArrays()`
3558: */
3559: PETSC_INTERN PetscErrorCode MatSetMPIAIJWithSplitSeqAIJ(Mat mat, Mat A, Mat B, PetscInt *garray)
3560: {
3561:   PetscFunctionBegin;
3562:   Mat_MPIAIJ *mpiaij = (Mat_MPIAIJ *)mat->data;
3563:   PetscInt    m, n, M, N, Am, An, Bm, Bn;

3565:   PetscCall(MatGetSize(mat, &M, &N));
3566:   PetscCall(MatGetLocalSize(mat, &m, &n));
3567:   PetscCall(MatGetLocalSize(A, &Am, &An));
3568:   PetscCall(MatGetLocalSize(B, &Bm, &Bn));

3570:   PetscCheck(m == Am && m == Bm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "local number of rows do not match");
3571:   PetscCheck(n == An, PETSC_COMM_SELF, PETSC_ERR_PLIB, "local number of columns do not match");
3572:   PetscCheck(!mpiaij->A && !mpiaij->B, PETSC_COMM_SELF, PETSC_ERR_PLIB, "A, B of the MPIAIJ matrix are not empty");
3573:   mpiaij->A      = A;
3574:   mpiaij->B      = B;
3575:   mpiaij->garray = garray;

3577:   mat->preallocated     = PETSC_TRUE;
3578:   mat->nooffprocentries = PETSC_TRUE; /* See MatAssemblyBegin_MPIAIJ. In effect, making MatAssemblyBegin a nop */

3580:   PetscCall(MatSetOption(mat, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
3581:   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
3582:   /* MatAssemblyEnd is critical here. It sets mat->offloadmask according to A and B's, and
3583:    also gets mpiaij->B compacted (if garray is NULL), with its col ids and size reduced
3584:    */
3585:   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
3586:   PetscCall(MatSetOption(mat, MAT_NO_OFF_PROC_ENTRIES, PETSC_FALSE));
3587:   PetscCall(MatSetOption(mat, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
3588:   PetscFunctionReturn(PETSC_SUCCESS);
3589: }

3591: extern PetscErrorCode MatCreateSubMatrices_MPIAIJ_SingleIS_Local(Mat, PetscInt, const IS[], const IS[], MatReuse, PetscBool, Mat *);

3593: PetscErrorCode MatCreateSubMatrix_MPIAIJ_SameRowDist(Mat mat, IS isrow, IS iscol, IS iscol_local, MatReuse call, Mat *newmat)
3594: {
3595:   PetscInt        i, m, n, rstart, row, rend, nz, j, bs, cbs;
3596:   PetscInt       *ii, *jj, nlocal, *dlens, *olens, dlen, olen, jend, mglobal;
3597:   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)mat->data;
3598:   Mat             M, Msub, B = a->B;
3599:   MatScalar      *aa;
3600:   Mat_SeqAIJ     *aij;
3601:   PetscInt       *garray = a->garray, *colsub, Ncols;
3602:   PetscInt        count, Bn = B->cmap->N, cstart = mat->cmap->rstart, cend = mat->cmap->rend;
3603:   IS              iscol_sub, iscmap;
3604:   const PetscInt *is_idx, *cmap;
3605:   PetscBool       allcolumns = PETSC_FALSE;
3606:   MPI_Comm        comm;

3608:   PetscFunctionBegin;
3609:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
3610:   if (call == MAT_REUSE_MATRIX) {
3611:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "SubIScol", (PetscObject *)&iscol_sub));
3612:     PetscCheck(iscol_sub, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SubIScol passed in was not used before, cannot reuse");
3613:     PetscCall(ISGetLocalSize(iscol_sub, &count));

3615:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "Subcmap", (PetscObject *)&iscmap));
3616:     PetscCheck(iscmap, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Subcmap passed in was not used before, cannot reuse");

3618:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "SubMatrix", (PetscObject *)&Msub));
3619:     PetscCheck(Msub, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Submatrix passed in was not used before, cannot reuse");

3621:     PetscCall(MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat, 1, &isrow, &iscol_sub, MAT_REUSE_MATRIX, PETSC_FALSE, &Msub));

3623:   } else { /* call == MAT_INITIAL_MATRIX) */
3624:     PetscBool flg;

3626:     PetscCall(ISGetLocalSize(iscol, &n));
3627:     PetscCall(ISGetSize(iscol, &Ncols));

3629:     /* (1) iscol -> nonscalable iscol_local */
3630:     /* Check for special case: each processor gets entire matrix columns */
3631:     PetscCall(ISIdentity(iscol_local, &flg));
3632:     if (flg && n == mat->cmap->N) allcolumns = PETSC_TRUE;
3633:     PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &allcolumns, 1, MPIU_BOOL, MPI_LAND, PetscObjectComm((PetscObject)mat)));
3634:     if (allcolumns) {
3635:       iscol_sub = iscol_local;
3636:       PetscCall(PetscObjectReference((PetscObject)iscol_local));
3637:       PetscCall(ISCreateStride(PETSC_COMM_SELF, n, 0, 1, &iscmap));

3639:     } else {
3640:       /* (2) iscol_local -> iscol_sub and iscmap. Implementation below requires iscol_local be sorted, it can have duplicate indices */
3641:       PetscInt *idx, *cmap1, k;
3642:       PetscCall(PetscMalloc1(Ncols, &idx));
3643:       PetscCall(PetscMalloc1(Ncols, &cmap1));
3644:       PetscCall(ISGetIndices(iscol_local, &is_idx));
3645:       count = 0;
3646:       k     = 0;
3647:       for (i = 0; i < Ncols; i++) {
3648:         j = is_idx[i];
3649:         if (j >= cstart && j < cend) {
3650:           /* diagonal part of mat */
3651:           idx[count]     = j;
3652:           cmap1[count++] = i; /* column index in submat */
3653:         } else if (Bn) {
3654:           /* off-diagonal part of mat */
3655:           if (j == garray[k]) {
3656:             idx[count]     = j;
3657:             cmap1[count++] = i; /* column index in submat */
3658:           } else if (j > garray[k]) {
3659:             while (j > garray[k] && k < Bn - 1) k++;
3660:             if (j == garray[k]) {
3661:               idx[count]     = j;
3662:               cmap1[count++] = i; /* column index in submat */
3663:             }
3664:           }
3665:         }
3666:       }
3667:       PetscCall(ISRestoreIndices(iscol_local, &is_idx));

3669:       PetscCall(ISCreateGeneral(PETSC_COMM_SELF, count, idx, PETSC_OWN_POINTER, &iscol_sub));
3670:       PetscCall(ISGetBlockSize(iscol, &cbs));
3671:       PetscCall(ISSetBlockSize(iscol_sub, cbs));

3673:       PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)iscol_local), count, cmap1, PETSC_OWN_POINTER, &iscmap));
3674:     }

3676:     /* (3) Create sequential Msub */
3677:     PetscCall(MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat, 1, &isrow, &iscol_sub, MAT_INITIAL_MATRIX, allcolumns, &Msub));
3678:   }

3680:   PetscCall(ISGetLocalSize(iscol_sub, &count));
3681:   aij = (Mat_SeqAIJ *)Msub->data;
3682:   ii  = aij->i;
3683:   PetscCall(ISGetIndices(iscmap, &cmap));

3685:   /*
3686:       m - number of local rows
3687:       Ncols - number of columns (same on all processors)
3688:       rstart - first row in new global matrix generated
3689:   */
3690:   PetscCall(MatGetSize(Msub, &m, NULL));

3692:   if (call == MAT_INITIAL_MATRIX) {
3693:     /* (4) Create parallel newmat */
3694:     PetscMPIInt rank, size;
3695:     PetscInt    csize;

3697:     PetscCallMPI(MPI_Comm_size(comm, &size));
3698:     PetscCallMPI(MPI_Comm_rank(comm, &rank));

3700:     /*
3701:         Determine the number of non-zeros in the diagonal and off-diagonal
3702:         portions of the matrix in order to do correct preallocation
3703:     */

3705:     /* first get start and end of "diagonal" columns */
3706:     PetscCall(ISGetLocalSize(iscol, &csize));
3707:     if (csize == PETSC_DECIDE) {
3708:       PetscCall(ISGetSize(isrow, &mglobal));
3709:       if (mglobal == Ncols) { /* square matrix */
3710:         nlocal = m;
3711:       } else {
3712:         nlocal = Ncols / size + ((Ncols % size) > rank);
3713:       }
3714:     } else {
3715:       nlocal = csize;
3716:     }
3717:     PetscCallMPI(MPI_Scan(&nlocal, &rend, 1, MPIU_INT, MPI_SUM, comm));
3718:     rstart = rend - nlocal;
3719:     PetscCheck(rank != size - 1 || rend == Ncols, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Local column sizes %" PetscInt_FMT " do not add up to total number of columns %" PetscInt_FMT, rend, Ncols);

3721:     /* next, compute all the lengths */
3722:     jj = aij->j;
3723:     PetscCall(PetscMalloc1(2 * m + 1, &dlens));
3724:     olens = dlens + m;
3725:     for (i = 0; i < m; i++) {
3726:       jend = ii[i + 1] - ii[i];
3727:       olen = 0;
3728:       dlen = 0;
3729:       for (j = 0; j < jend; j++) {
3730:         if (cmap[*jj] < rstart || cmap[*jj] >= rend) olen++;
3731:         else dlen++;
3732:         jj++;
3733:       }
3734:       olens[i] = olen;
3735:       dlens[i] = dlen;
3736:     }

3738:     PetscCall(ISGetBlockSize(isrow, &bs));
3739:     PetscCall(ISGetBlockSize(iscol, &cbs));

3741:     PetscCall(MatCreate(comm, &M));
3742:     PetscCall(MatSetSizes(M, m, nlocal, PETSC_DECIDE, Ncols));
3743:     PetscCall(MatSetBlockSizes(M, bs, cbs));
3744:     PetscCall(MatSetType(M, ((PetscObject)mat)->type_name));
3745:     PetscCall(MatMPIAIJSetPreallocation(M, 0, dlens, 0, olens));
3746:     PetscCall(PetscFree(dlens));

3748:   } else { /* call == MAT_REUSE_MATRIX */
3749:     M = *newmat;
3750:     PetscCall(MatGetLocalSize(M, &i, NULL));
3751:     PetscCheck(i == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Previous matrix must be same size/layout as request");
3752:     PetscCall(MatZeroEntries(M));
3753:     /*
3754:          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3755:        rather than the slower MatSetValues().
3756:     */
3757:     M->was_assembled = PETSC_TRUE;
3758:     M->assembled     = PETSC_FALSE;
3759:   }

3761:   /* (5) Set values of Msub to *newmat */
3762:   PetscCall(PetscMalloc1(count, &colsub));
3763:   PetscCall(MatGetOwnershipRange(M, &rstart, NULL));

3765:   jj = aij->j;
3766:   PetscCall(MatSeqAIJGetArrayRead(Msub, (const PetscScalar **)&aa));
3767:   for (i = 0; i < m; i++) {
3768:     row = rstart + i;
3769:     nz  = ii[i + 1] - ii[i];
3770:     for (j = 0; j < nz; j++) colsub[j] = cmap[jj[j]];
3771:     PetscCall(MatSetValues_MPIAIJ(M, 1, &row, nz, colsub, aa, INSERT_VALUES));
3772:     jj += nz;
3773:     aa += nz;
3774:   }
3775:   PetscCall(MatSeqAIJRestoreArrayRead(Msub, (const PetscScalar **)&aa));
3776:   PetscCall(ISRestoreIndices(iscmap, &cmap));

3778:   PetscCall(MatAssemblyBegin(M, MAT_FINAL_ASSEMBLY));
3779:   PetscCall(MatAssemblyEnd(M, MAT_FINAL_ASSEMBLY));

3781:   PetscCall(PetscFree(colsub));

3783:   /* save Msub, iscol_sub and iscmap used in processor for next request */
3784:   if (call == MAT_INITIAL_MATRIX) {
3785:     *newmat = M;
3786:     PetscCall(PetscObjectCompose((PetscObject)*newmat, "SubMatrix", (PetscObject)Msub));
3787:     PetscCall(MatDestroy(&Msub));

3789:     PetscCall(PetscObjectCompose((PetscObject)*newmat, "SubIScol", (PetscObject)iscol_sub));
3790:     PetscCall(ISDestroy(&iscol_sub));

3792:     PetscCall(PetscObjectCompose((PetscObject)*newmat, "Subcmap", (PetscObject)iscmap));
3793:     PetscCall(ISDestroy(&iscmap));

3795:     if (iscol_local) {
3796:       PetscCall(PetscObjectCompose((PetscObject)*newmat, "ISAllGather", (PetscObject)iscol_local));
3797:       PetscCall(ISDestroy(&iscol_local));
3798:     }
3799:   }
3800:   PetscFunctionReturn(PETSC_SUCCESS);
3801: }

3803: /*
3804:     Not great since it makes two copies of the submatrix, first an SeqAIJ
3805:   in local and then by concatenating the local matrices the end result.
3806:   Writing it directly would be much like MatCreateSubMatrices_MPIAIJ()

3808:   This requires a sequential iscol with all indices.
3809: */
3810: PetscErrorCode MatCreateSubMatrix_MPIAIJ_nonscalable(Mat mat, IS isrow, IS iscol, PetscInt csize, MatReuse call, Mat *newmat)
3811: {
3812:   PetscMPIInt rank, size;
3813:   PetscInt    i, m, n, rstart, row, rend, nz, *cwork, j, bs, cbs;
3814:   PetscInt   *ii, *jj, nlocal, *dlens, *olens, dlen, olen, jend, mglobal;
3815:   Mat         M, Mreuse;
3816:   MatScalar  *aa, *vwork;
3817:   MPI_Comm    comm;
3818:   Mat_SeqAIJ *aij;
3819:   PetscBool   colflag, allcolumns = PETSC_FALSE;

3821:   PetscFunctionBegin;
3822:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
3823:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
3824:   PetscCallMPI(MPI_Comm_size(comm, &size));

3826:   /* Check for special case: each processor gets entire matrix columns */
3827:   PetscCall(ISIdentity(iscol, &colflag));
3828:   PetscCall(ISGetLocalSize(iscol, &n));
3829:   if (colflag && n == mat->cmap->N) allcolumns = PETSC_TRUE;
3830:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &allcolumns, 1, MPIU_BOOL, MPI_LAND, PetscObjectComm((PetscObject)mat)));

3832:   if (call == MAT_REUSE_MATRIX) {
3833:     PetscCall(PetscObjectQuery((PetscObject)*newmat, "SubMatrix", (PetscObject *)&Mreuse));
3834:     PetscCheck(Mreuse, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Submatrix passed in was not used before, cannot reuse");
3835:     PetscCall(MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat, 1, &isrow, &iscol, MAT_REUSE_MATRIX, allcolumns, &Mreuse));
3836:   } else {
3837:     PetscCall(MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat, 1, &isrow, &iscol, MAT_INITIAL_MATRIX, allcolumns, &Mreuse));
3838:   }

3840:   /*
3841:       m - number of local rows
3842:       n - number of columns (same on all processors)
3843:       rstart - first row in new global matrix generated
3844:   */
3845:   PetscCall(MatGetSize(Mreuse, &m, &n));
3846:   PetscCall(MatGetBlockSizes(Mreuse, &bs, &cbs));
3847:   if (call == MAT_INITIAL_MATRIX) {
3848:     aij = (Mat_SeqAIJ *)Mreuse->data;
3849:     ii  = aij->i;
3850:     jj  = aij->j;

3852:     /*
3853:         Determine the number of non-zeros in the diagonal and off-diagonal
3854:         portions of the matrix in order to do correct preallocation
3855:     */

3857:     /* first get start and end of "diagonal" columns */
3858:     if (csize == PETSC_DECIDE) {
3859:       PetscCall(ISGetSize(isrow, &mglobal));
3860:       if (mglobal == n) { /* square matrix */
3861:         nlocal = m;
3862:       } else {
3863:         nlocal = n / size + ((n % size) > rank);
3864:       }
3865:     } else {
3866:       nlocal = csize;
3867:     }
3868:     PetscCallMPI(MPI_Scan(&nlocal, &rend, 1, MPIU_INT, MPI_SUM, comm));
3869:     rstart = rend - nlocal;
3870:     PetscCheck(rank != size - 1 || rend == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Local column sizes %" PetscInt_FMT " do not add up to total number of columns %" PetscInt_FMT, rend, n);

3872:     /* next, compute all the lengths */
3873:     PetscCall(PetscMalloc1(2 * m + 1, &dlens));
3874:     olens = dlens + m;
3875:     for (i = 0; i < m; i++) {
3876:       jend = ii[i + 1] - ii[i];
3877:       olen = 0;
3878:       dlen = 0;
3879:       for (j = 0; j < jend; j++) {
3880:         if (*jj < rstart || *jj >= rend) olen++;
3881:         else dlen++;
3882:         jj++;
3883:       }
3884:       olens[i] = olen;
3885:       dlens[i] = dlen;
3886:     }
3887:     PetscCall(MatCreate(comm, &M));
3888:     PetscCall(MatSetSizes(M, m, nlocal, PETSC_DECIDE, n));
3889:     PetscCall(MatSetBlockSizes(M, bs, cbs));
3890:     PetscCall(MatSetType(M, ((PetscObject)mat)->type_name));
3891:     PetscCall(MatMPIAIJSetPreallocation(M, 0, dlens, 0, olens));
3892:     PetscCall(PetscFree(dlens));
3893:   } else {
3894:     PetscInt ml, nl;

3896:     M = *newmat;
3897:     PetscCall(MatGetLocalSize(M, &ml, &nl));
3898:     PetscCheck(ml == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Previous matrix must be same size/layout as request");
3899:     PetscCall(MatZeroEntries(M));
3900:     /*
3901:          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3902:        rather than the slower MatSetValues().
3903:     */
3904:     M->was_assembled = PETSC_TRUE;
3905:     M->assembled     = PETSC_FALSE;
3906:   }
3907:   PetscCall(MatGetOwnershipRange(M, &rstart, &rend));
3908:   aij = (Mat_SeqAIJ *)Mreuse->data;
3909:   ii  = aij->i;
3910:   jj  = aij->j;

3912:   /* trigger copy to CPU if needed */
3913:   PetscCall(MatSeqAIJGetArrayRead(Mreuse, (const PetscScalar **)&aa));
3914:   for (i = 0; i < m; i++) {
3915:     row   = rstart + i;
3916:     nz    = ii[i + 1] - ii[i];
3917:     cwork = jj;
3918:     jj    = PetscSafePointerPlusOffset(jj, nz);
3919:     vwork = aa;
3920:     aa    = PetscSafePointerPlusOffset(aa, nz);
3921:     PetscCall(MatSetValues_MPIAIJ(M, 1, &row, nz, cwork, vwork, INSERT_VALUES));
3922:   }
3923:   PetscCall(MatSeqAIJRestoreArrayRead(Mreuse, (const PetscScalar **)&aa));

3925:   PetscCall(MatAssemblyBegin(M, MAT_FINAL_ASSEMBLY));
3926:   PetscCall(MatAssemblyEnd(M, MAT_FINAL_ASSEMBLY));
3927:   *newmat = M;

3929:   /* save submatrix used in processor for next request */
3930:   if (call == MAT_INITIAL_MATRIX) {
3931:     PetscCall(PetscObjectCompose((PetscObject)M, "SubMatrix", (PetscObject)Mreuse));
3932:     PetscCall(MatDestroy(&Mreuse));
3933:   }
3934:   PetscFunctionReturn(PETSC_SUCCESS);
3935: }

3937: static PetscErrorCode MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B, const PetscInt Ii[], const PetscInt J[], const PetscScalar v[])
3938: {
3939:   PetscInt        m, cstart, cend, j, nnz, i, d, *ld;
3940:   PetscInt       *d_nnz, *o_nnz, nnz_max = 0, rstart, ii, irstart;
3941:   const PetscInt *JJ;
3942:   PetscBool       nooffprocentries;
3943:   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ *)B->data;

3945:   PetscFunctionBegin;
3946:   PetscCall(PetscLayoutSetUp(B->rmap));
3947:   PetscCall(PetscLayoutSetUp(B->cmap));
3948:   m       = B->rmap->n;
3949:   cstart  = B->cmap->rstart;
3950:   cend    = B->cmap->rend;
3951:   rstart  = B->rmap->rstart;
3952:   irstart = Ii[0];

3954:   PetscCall(PetscCalloc2(m, &d_nnz, m, &o_nnz));

3956:   if (PetscDefined(USE_DEBUG)) {
3957:     for (i = 0; i < m; i++) {
3958:       nnz = Ii[i + 1] - Ii[i];
3959:       JJ  = PetscSafePointerPlusOffset(J, Ii[i] - irstart);
3960:       PetscCheck(nnz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local row %" PetscInt_FMT " has a negative %" PetscInt_FMT " number of columns", i, nnz);
3961:       PetscCheck(!nnz || !(JJ[0] < 0), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Row %" PetscInt_FMT " starts with negative column index %" PetscInt_FMT, i, JJ[0]);
3962:       PetscCheck(!nnz || !(JJ[nnz - 1] >= B->cmap->N), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Row %" PetscInt_FMT " ends with too large a column index %" PetscInt_FMT " (max allowed %" PetscInt_FMT ")", i, JJ[nnz - 1], B->cmap->N);
3963:     }
3964:   }

3966:   for (i = 0; i < m; i++) {
3967:     nnz     = Ii[i + 1] - Ii[i];
3968:     JJ      = PetscSafePointerPlusOffset(J, Ii[i] - irstart);
3969:     nnz_max = PetscMax(nnz_max, nnz);
3970:     d       = 0;
3971:     for (j = 0; j < nnz; j++) {
3972:       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3973:     }
3974:     d_nnz[i] = d;
3975:     o_nnz[i] = nnz - d;
3976:   }
3977:   PetscCall(MatMPIAIJSetPreallocation(B, 0, d_nnz, 0, o_nnz));
3978:   PetscCall(PetscFree2(d_nnz, o_nnz));

3980:   for (i = 0; i < m; i++) {
3981:     ii = i + rstart;
3982:     PetscCall(MatSetValues_MPIAIJ(B, 1, &ii, Ii[i + 1] - Ii[i], PetscSafePointerPlusOffset(J, Ii[i] - irstart), PetscSafePointerPlusOffset(v, Ii[i] - irstart), INSERT_VALUES));
3983:   }
3984:   nooffprocentries    = B->nooffprocentries;
3985:   B->nooffprocentries = PETSC_TRUE;
3986:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
3987:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
3988:   B->nooffprocentries = nooffprocentries;

3990:   /* count number of entries below block diagonal */
3991:   PetscCall(PetscFree(Aij->ld));
3992:   PetscCall(PetscCalloc1(m, &ld));
3993:   Aij->ld = ld;
3994:   for (i = 0; i < m; i++) {
3995:     nnz = Ii[i + 1] - Ii[i];
3996:     j   = 0;
3997:     while (j < nnz && J[j] < cstart) j++;
3998:     ld[i] = j;
3999:     if (J) J += nnz;
4000:   }

4002:   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
4003:   PetscFunctionReturn(PETSC_SUCCESS);
4004: }

4006: /*@
4007:   MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in `MATAIJ` format
4008:   (the default parallel PETSc format).

4010:   Collective

4012:   Input Parameters:
4013: + B - the matrix
4014: . i - the indices into `j` for the start of each local row (indices start with zero)
4015: . j - the column indices for each local row (indices start with zero)
4016: - v - optional values in the matrix

4018:   Level: developer

4020:   Notes:
4021:   The `i`, `j`, and `v` arrays ARE copied by this routine into the internal format used by PETSc;
4022:   thus you CANNOT change the matrix entries by changing the values of `v` after you have
4023:   called this routine. Use `MatCreateMPIAIJWithSplitArrays()` to avoid needing to copy the arrays.

4025:   The `i` and `j` indices are 0 based, and `i` indices are indices corresponding to the local `j` array.

4027:   A convenience routine for this functionality is `MatCreateMPIAIJWithArrays()`.

4029:   You can update the matrix with new numerical values using `MatUpdateMPIAIJWithArrays()` after this call if the column indices in `j` are sorted.

4031:   If you do **not** use `MatUpdateMPIAIJWithArrays()`, the column indices in `j` do not need to be sorted. If you will use
4032:   `MatUpdateMPIAIJWithArrays()`, the column indices **must** be sorted.

4034:   The format which is used for the sparse matrix input, is equivalent to a
4035:   row-major ordering.. i.e for the following matrix, the input data expected is
4036:   as shown
4037: .vb
4038:         1 0 0
4039:         2 0 3     P0
4040:        -------
4041:         4 5 6     P1

4043:      Process0 [P0] rows_owned=[0,1]
4044:         i =  {0,1,3}  [size = nrow+1  = 2+1]
4045:         j =  {0,0,2}  [size = 3]
4046:         v =  {1,2,3}  [size = 3]

4048:      Process1 [P1] rows_owned=[2]
4049:         i =  {0,3}    [size = nrow+1  = 1+1]
4050:         j =  {0,1,2}  [size = 3]
4051:         v =  {4,5,6}  [size = 3]
4052: .ve

4054: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatCreateAIJ()`,
4055:           `MatCreateSeqAIJWithArrays()`, `MatCreateMPIAIJWithSplitArrays()`, `MatCreateMPIAIJWithArrays()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
4056: @*/
4057: PetscErrorCode MatMPIAIJSetPreallocationCSR(Mat B, const PetscInt i[], const PetscInt j[], const PetscScalar v[])
4058: {
4059:   PetscFunctionBegin;
4060:   PetscTryMethod(B, "MatMPIAIJSetPreallocationCSR_C", (Mat, const PetscInt[], const PetscInt[], const PetscScalar[]), (B, i, j, v));
4061:   PetscFunctionReturn(PETSC_SUCCESS);
4062: }

4064: /*@
4065:   MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in `MATMPIAIJ` format
4066:   (the default parallel PETSc format).  For good matrix assembly performance
4067:   the user should preallocate the matrix storage by setting the parameters
4068:   `d_nz` (or `d_nnz`) and `o_nz` (or `o_nnz`).

4070:   Collective

4072:   Input Parameters:
4073: + B     - the matrix
4074: . d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4075:            (same value is used for all local rows)
4076: . d_nnz - array containing the number of nonzeros in the various rows of the
4077:            DIAGONAL portion of the local submatrix (possibly different for each row)
4078:            or `NULL` (`PETSC_NULL_INTEGER` in Fortran), if `d_nz` is used to specify the nonzero structure.
4079:            The size of this array is equal to the number of local rows, i.e 'm'.
4080:            For matrices that will be factored, you must leave room for (and set)
4081:            the diagonal entry even if it is zero.
4082: . o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4083:            submatrix (same value is used for all local rows).
4084: - o_nnz - array containing the number of nonzeros in the various rows of the
4085:            OFF-DIAGONAL portion of the local submatrix (possibly different for
4086:            each row) or `NULL` (`PETSC_NULL_INTEGER` in Fortran), if `o_nz` is used to specify the nonzero
4087:            structure. The size of this array is equal to the number
4088:            of local rows, i.e 'm'.

4090:   Example Usage:
4091:   Consider the following 8x8 matrix with 34 non-zero values, that is
4092:   assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4093:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4094:   as follows

4096: .vb
4097:             1  2  0  |  0  3  0  |  0  4
4098:     Proc0   0  5  6  |  7  0  0  |  8  0
4099:             9  0 10  | 11  0  0  | 12  0
4100:     -------------------------------------
4101:            13  0 14  | 15 16 17  |  0  0
4102:     Proc1   0 18  0  | 19 20 21  |  0  0
4103:             0  0  0  | 22 23  0  | 24  0
4104:     -------------------------------------
4105:     Proc2  25 26 27  |  0  0 28  | 29  0
4106:            30  0  0  | 31 32 33  |  0 34
4107: .ve

4109:   This can be represented as a collection of submatrices as
4110: .vb
4111:       A B C
4112:       D E F
4113:       G H I
4114: .ve

4116:   Where the submatrices A,B,C are owned by proc0, D,E,F are
4117:   owned by proc1, G,H,I are owned by proc2.

4119:   The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4120:   The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4121:   The 'M','N' parameters are 8,8, and have the same values on all procs.

4123:   The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4124:   submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4125:   corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4126:   Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4127:   part as `MATSEQAIJ` matrices. For example, proc1 will store [E] as a `MATSEQAIJ`
4128:   matrix, and [DF] as another `MATSEQAIJ` matrix.

4130:   When `d_nz`, `o_nz` parameters are specified, `d_nz` storage elements are
4131:   allocated for every row of the local DIAGONAL submatrix, and `o_nz`
4132:   storage locations are allocated for every row of the OFF-DIAGONAL submatrix.
4133:   One way to choose `d_nz` and `o_nz` is to use the maximum number of nonzeros over
4134:   the local rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4135:   In this case, the values of `d_nz`, `o_nz` are
4136: .vb
4137:      proc0  dnz = 2, o_nz = 2
4138:      proc1  dnz = 3, o_nz = 2
4139:      proc2  dnz = 1, o_nz = 4
4140: .ve
4141:   We are allocating `m`*(`d_nz`+`o_nz`) storage locations for every proc. This
4142:   translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4143:   for proc3. i.e we are using 12+15+10=37 storage locations to store
4144:   34 values.

4146:   When `d_nnz`, `o_nnz` parameters are specified, the storage is specified
4147:   for every row, corresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4148:   In the above case the values for `d_nnz`, `o_nnz` are
4149: .vb
4150:      proc0 d_nnz = [2,2,2] and o_nnz = [2,2,2]
4151:      proc1 d_nnz = [3,3,2] and o_nnz = [2,1,1]
4152:      proc2 d_nnz = [1,1]   and o_nnz = [4,4]
4153: .ve
4154:   Here the space allocated is sum of all the above values i.e 34, and
4155:   hence pre-allocation is perfect.

4157:   Level: intermediate

4159:   Notes:
4160:   If the *_nnz parameter is given then the *_nz parameter is ignored

4162:   The `MATAIJ` format, also called compressed row storage (CSR), is compatible with standard Fortran
4163:   storage.  The stored row and column indices begin with zero.
4164:   See [Sparse Matrices](sec_matsparse) for details.

4166:   The parallel matrix is partitioned such that the first m0 rows belong to
4167:   process 0, the next m1 rows belong to process 1, the next m2 rows belong
4168:   to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.

4170:   The DIAGONAL portion of the local submatrix of a processor can be defined
4171:   as the submatrix which is obtained by extraction the part corresponding to
4172:   the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
4173:   first row that belongs to the processor, r2 is the last row belonging to
4174:   the this processor, and c1-c2 is range of indices of the local part of a
4175:   vector suitable for applying the matrix to.  This is an mxn matrix.  In the
4176:   common case of a square matrix, the row and column ranges are the same and
4177:   the DIAGONAL part is also square. The remaining portion of the local
4178:   submatrix (mxN) constitute the OFF-DIAGONAL portion.

4180:   If `o_nnz` and `d_nnz` are specified, then `o_nz` and `d_nz` are ignored.

4182:   You can call `MatGetInfo()` to get information on how effective the preallocation was;
4183:   for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
4184:   You can also run with the option `-info` and look for messages with the string
4185:   malloc in them to see if additional memory allocation was needed.

4187: .seealso: [](ch_matrices), `Mat`, [Sparse Matrices](sec_matsparse), `MATMPIAIJ`, `MATAIJ`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatCreateAIJ()`, `MatMPIAIJSetPreallocationCSR()`,
4188:           `MatGetInfo()`, `PetscSplitOwnership()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
4189: @*/
4190: PetscErrorCode MatMPIAIJSetPreallocation(Mat B, PetscInt d_nz, const PetscInt d_nnz[], PetscInt o_nz, const PetscInt o_nnz[])
4191: {
4192:   PetscFunctionBegin;
4195:   PetscTryMethod(B, "MatMPIAIJSetPreallocation_C", (Mat, PetscInt, const PetscInt[], PetscInt, const PetscInt[]), (B, d_nz, d_nnz, o_nz, o_nnz));
4196:   PetscFunctionReturn(PETSC_SUCCESS);
4197: }

4199: /*@
4200:   MatCreateMPIAIJWithArrays - creates a `MATMPIAIJ` matrix using arrays that contain in standard
4201:   CSR format for the local rows.

4203:   Collective

4205:   Input Parameters:
4206: + comm - MPI communicator
4207: . m    - number of local rows (Cannot be `PETSC_DECIDE`)
4208: . n    - This value should be the same as the local size used in creating the
4209:          x vector for the matrix-vector product $ y = Ax$. (or `PETSC_DECIDE` to have
4210:          calculated if `N` is given) For square matrices n is almost always `m`.
4211: . M    - number of global rows (or `PETSC_DETERMINE` to have calculated if `m` is given)
4212: . N    - number of global columns (or `PETSC_DETERMINE` to have calculated if `n` is given)
4213: . i    - row indices (of length m+1); that is i[0] = 0, i[row] = i[row-1] + number of elements in that row of the matrix
4214: . j    - global column indices
4215: - a    - optional matrix values

4217:   Output Parameter:
4218: . mat - the matrix

4220:   Level: intermediate

4222:   Notes:
4223:   The `i`, `j`, and `a` arrays ARE copied by this routine into the internal format used by PETSc;
4224:   thus you CANNOT change the matrix entries by changing the values of `a[]` after you have
4225:   called this routine. Use `MatCreateMPIAIJWithSplitArrays()` to avoid needing to copy the arrays.

4227:   The `i` and `j` indices are 0 based, and `i` indices are indices corresponding to the local `j` array.

4229:   Once you have created the matrix you can update it with new numerical values using `MatUpdateMPIAIJWithArray()`

4231:   If you do **not** use `MatUpdateMPIAIJWithArray()`, the column indices in `j` do not need to be sorted. If you will use
4232:   `MatUpdateMPIAIJWithArrays()`, the column indices **must** be sorted.

4234:   The format which is used for the sparse matrix input, is equivalent to a
4235:   row-major ordering, i.e., for the following matrix, the input data expected is
4236:   as shown
4237: .vb
4238:         1 0 0
4239:         2 0 3     P0
4240:        -------
4241:         4 5 6     P1

4243:      Process0 [P0] rows_owned=[0,1]
4244:         i =  {0,1,3}  [size = nrow+1  = 2+1]
4245:         j =  {0,0,2}  [size = 3]
4246:         v =  {1,2,3}  [size = 3]

4248:      Process1 [P1] rows_owned=[2]
4249:         i =  {0,3}    [size = nrow+1  = 1+1]
4250:         j =  {0,1,2}  [size = 3]
4251:         v =  {4,5,6}  [size = 3]
4252: .ve

4254: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`,
4255:           `MATMPIAIJ`, `MatCreateAIJ()`, `MatCreateMPIAIJWithSplitArrays()`, `MatUpdateMPIAIJWithArray()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
4256: @*/
4257: PetscErrorCode MatCreateMPIAIJWithArrays(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, const PetscInt i[], const PetscInt j[], const PetscScalar a[], Mat *mat)
4258: {
4259:   PetscFunctionBegin;
4260:   PetscCheck(!i || !i[0], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
4261:   PetscCheck(m >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "local number of rows (m) cannot be PETSC_DECIDE, or negative");
4262:   PetscCall(MatCreate(comm, mat));
4263:   PetscCall(MatSetSizes(*mat, m, n, M, N));
4264:   /* PetscCall(MatSetBlockSizes(M,bs,cbs)); */
4265:   PetscCall(MatSetType(*mat, MATMPIAIJ));
4266:   PetscCall(MatMPIAIJSetPreallocationCSR(*mat, i, j, a));
4267:   PetscFunctionReturn(PETSC_SUCCESS);
4268: }

4270: /*@
4271:   MatUpdateMPIAIJWithArrays - updates a `MATMPIAIJ` matrix using arrays that contain in standard
4272:   CSR format for the local rows. Only the numerical values are updated the other arrays must be identical to what was passed
4273:   from `MatCreateMPIAIJWithArrays()`

4275:   Deprecated: Use `MatUpdateMPIAIJWithArray()`

4277:   Collective

4279:   Input Parameters:
4280: + mat - the matrix
4281: . m   - number of local rows (Cannot be `PETSC_DECIDE`)
4282: . n   - This value should be the same as the local size used in creating the
4283:        x vector for the matrix-vector product y = Ax. (or `PETSC_DECIDE` to have
4284:        calculated if N is given) For square matrices n is almost always m.
4285: . M   - number of global rows (or `PETSC_DETERMINE` to have calculated if m is given)
4286: . N   - number of global columns (or `PETSC_DETERMINE` to have calculated if n is given)
4287: . Ii  - row indices; that is Ii[0] = 0, Ii[row] = Ii[row-1] + number of elements in that row of the matrix
4288: . J   - column indices
4289: - v   - matrix values

4291:   Level: deprecated

4293: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`,
4294:           `MatCreateAIJ()`, `MatCreateMPIAIJWithSplitArrays()`, `MatUpdateMPIAIJWithArray()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
4295: @*/
4296: PetscErrorCode MatUpdateMPIAIJWithArrays(Mat mat, PetscInt m, PetscInt n, PetscInt M, PetscInt N, const PetscInt Ii[], const PetscInt J[], const PetscScalar v[])
4297: {
4298:   PetscInt        nnz, i;
4299:   PetscBool       nooffprocentries;
4300:   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ *)mat->data;
4301:   Mat_SeqAIJ     *Ad  = (Mat_SeqAIJ *)Aij->A->data;
4302:   PetscScalar    *ad, *ao;
4303:   PetscInt        ldi, Iii, md;
4304:   const PetscInt *Adi = Ad->i;
4305:   PetscInt       *ld  = Aij->ld;

4307:   PetscFunctionBegin;
4308:   PetscCheck(Ii[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
4309:   PetscCheck(m >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "local number of rows (m) cannot be PETSC_DECIDE, or negative");
4310:   PetscCheck(m == mat->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Local number of rows cannot change from call to MatUpdateMPIAIJWithArrays()");
4311:   PetscCheck(n == mat->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Local number of columns cannot change from call to MatUpdateMPIAIJWithArrays()");

4313:   PetscCall(MatSeqAIJGetArrayWrite(Aij->A, &ad));
4314:   PetscCall(MatSeqAIJGetArrayWrite(Aij->B, &ao));

4316:   for (i = 0; i < m; i++) {
4317:     if (PetscDefined(USE_DEBUG)) {
4318:       for (PetscInt j = Ii[i] + 1; j < Ii[i + 1]; ++j) {
4319:         PetscCheck(J[j] >= J[j - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is not sorted", j - Ii[i], J[j], i);
4320:         PetscCheck(J[j] != J[j - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is identical to previous entry", j - Ii[i], J[j], i);
4321:       }
4322:     }
4323:     nnz = Ii[i + 1] - Ii[i];
4324:     Iii = Ii[i];
4325:     ldi = ld[i];
4326:     md  = Adi[i + 1] - Adi[i];
4327:     PetscCall(PetscArraycpy(ao, v + Iii, ldi));
4328:     PetscCall(PetscArraycpy(ad, v + Iii + ldi, md));
4329:     PetscCall(PetscArraycpy(ao + ldi, v + Iii + ldi + md, nnz - ldi - md));
4330:     ad += md;
4331:     ao += nnz - md;
4332:   }
4333:   nooffprocentries      = mat->nooffprocentries;
4334:   mat->nooffprocentries = PETSC_TRUE;
4335:   PetscCall(MatSeqAIJRestoreArrayWrite(Aij->A, &ad));
4336:   PetscCall(MatSeqAIJRestoreArrayWrite(Aij->B, &ao));
4337:   PetscCall(PetscObjectStateIncrease((PetscObject)Aij->A));
4338:   PetscCall(PetscObjectStateIncrease((PetscObject)Aij->B));
4339:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
4340:   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
4341:   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
4342:   mat->nooffprocentries = nooffprocentries;
4343:   PetscFunctionReturn(PETSC_SUCCESS);
4344: }

4346: /*@
4347:   MatUpdateMPIAIJWithArray - updates an `MATMPIAIJ` matrix using an array that contains the nonzero values

4349:   Collective

4351:   Input Parameters:
4352: + mat - the matrix
4353: - v   - matrix values, stored by row

4355:   Level: intermediate

4357:   Notes:
4358:   The matrix must have been obtained with `MatCreateMPIAIJWithArrays()` or `MatMPIAIJSetPreallocationCSR()`

4360:   The column indices in the call to `MatCreateMPIAIJWithArrays()` or `MatMPIAIJSetPreallocationCSR()` must have been sorted for this call to work correctly

4362: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`,
4363:           `MATMPIAIJ`, `MatCreateAIJ()`, `MatCreateMPIAIJWithSplitArrays()`, `MatUpdateMPIAIJWithArrays()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
4364: @*/
4365: PetscErrorCode MatUpdateMPIAIJWithArray(Mat mat, const PetscScalar v[])
4366: {
4367:   PetscInt        nnz, i, m;
4368:   PetscBool       nooffprocentries;
4369:   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ *)mat->data;
4370:   Mat_SeqAIJ     *Ad  = (Mat_SeqAIJ *)Aij->A->data;
4371:   Mat_SeqAIJ     *Ao  = (Mat_SeqAIJ *)Aij->B->data;
4372:   PetscScalar    *ad, *ao;
4373:   const PetscInt *Adi = Ad->i, *Adj = Ao->i;
4374:   PetscInt        ldi, Iii, md;
4375:   PetscInt       *ld = Aij->ld;

4377:   PetscFunctionBegin;
4378:   m = mat->rmap->n;

4380:   PetscCall(MatSeqAIJGetArrayWrite(Aij->A, &ad));
4381:   PetscCall(MatSeqAIJGetArrayWrite(Aij->B, &ao));
4382:   Iii = 0;
4383:   for (i = 0; i < m; i++) {
4384:     nnz = Adi[i + 1] - Adi[i] + Adj[i + 1] - Adj[i];
4385:     ldi = ld[i];
4386:     md  = Adi[i + 1] - Adi[i];
4387:     PetscCall(PetscArraycpy(ad, v + Iii + ldi, md));
4388:     ad += md;
4389:     if (ao) {
4390:       PetscCall(PetscArraycpy(ao, v + Iii, ldi));
4391:       PetscCall(PetscArraycpy(ao + ldi, v + Iii + ldi + md, nnz - ldi - md));
4392:       ao += nnz - md;
4393:     }
4394:     Iii += nnz;
4395:   }
4396:   nooffprocentries      = mat->nooffprocentries;
4397:   mat->nooffprocentries = PETSC_TRUE;
4398:   PetscCall(MatSeqAIJRestoreArrayWrite(Aij->A, &ad));
4399:   PetscCall(MatSeqAIJRestoreArrayWrite(Aij->B, &ao));
4400:   PetscCall(PetscObjectStateIncrease((PetscObject)Aij->A));
4401:   PetscCall(PetscObjectStateIncrease((PetscObject)Aij->B));
4402:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
4403:   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
4404:   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
4405:   mat->nooffprocentries = nooffprocentries;
4406:   PetscFunctionReturn(PETSC_SUCCESS);
4407: }

4409: /*@
4410:   MatCreateAIJ - Creates a sparse parallel matrix in `MATAIJ` format
4411:   (the default parallel PETSc format).  For good matrix assembly performance
4412:   the user should preallocate the matrix storage by setting the parameters
4413:   `d_nz` (or `d_nnz`) and `o_nz` (or `o_nnz`).

4415:   Collective

4417:   Input Parameters:
4418: + comm  - MPI communicator
4419: . m     - number of local rows (or `PETSC_DECIDE` to have calculated if M is given)
4420:           This value should be the same as the local size used in creating the
4421:           y vector for the matrix-vector product y = Ax.
4422: . n     - This value should be the same as the local size used in creating the
4423:           x vector for the matrix-vector product y = Ax. (or `PETSC_DECIDE` to have
4424:           calculated if N is given) For square matrices n is almost always m.
4425: . M     - number of global rows (or `PETSC_DETERMINE` to have calculated if m is given)
4426: . N     - number of global columns (or `PETSC_DETERMINE` to have calculated if n is given)
4427: . d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4428:           (same value is used for all local rows)
4429: . d_nnz - array containing the number of nonzeros in the various rows of the
4430:           DIAGONAL portion of the local submatrix (possibly different for each row)
4431:           or `NULL`, if `d_nz` is used to specify the nonzero structure.
4432:           The size of this array is equal to the number of local rows, i.e 'm'.
4433: . o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4434:           submatrix (same value is used for all local rows).
4435: - o_nnz - array containing the number of nonzeros in the various rows of the
4436:           OFF-DIAGONAL portion of the local submatrix (possibly different for
4437:           each row) or `NULL`, if `o_nz` is used to specify the nonzero
4438:           structure. The size of this array is equal to the number
4439:           of local rows, i.e 'm'.

4441:   Output Parameter:
4442: . A - the matrix

4444:   Options Database Keys:
4445: + -mat_no_inode                     - Do not use inodes
4446: . -mat_inode_limit <limit>          - Sets inode limit (max limit=5)
4447: - -matmult_vecscatter_view <viewer> - View the vecscatter (i.e., communication pattern) used in `MatMult()` of sparse parallel matrices.
4448:                                       See viewer types in manual of `MatView()`. Of them, ascii_matlab, draw or binary cause the `VecScatter`
4449:                                       to be viewed as a matrix. Entry (i,j) is the size of message (in bytes) rank i sends to rank j in one `MatMult()` call.

4451:   Level: intermediate

4453:   Notes:
4454:   It is recommended that one use `MatCreateFromOptions()` or the `MatCreate()`, `MatSetType()` and/or `MatSetFromOptions()`,
4455:   MatXXXXSetPreallocation() paradigm instead of this routine directly.
4456:   [MatXXXXSetPreallocation() is, for example, `MatSeqAIJSetPreallocation()`]

4458:   If the *_nnz parameter is given then the *_nz parameter is ignored

4460:   The `m`,`n`,`M`,`N` parameters specify the size of the matrix, and its partitioning across
4461:   processors, while `d_nz`,`d_nnz`,`o_nz`,`o_nnz` parameters specify the approximate
4462:   storage requirements for this matrix.

4464:   If `PETSC_DECIDE` or  `PETSC_DETERMINE` is used for a particular argument on one
4465:   processor than it must be used on all processors that share the object for
4466:   that argument.

4468:   If `m` and `n` are not `PETSC_DECIDE`, then the values determine the `PetscLayout` of the matrix and the ranges returned by
4469:   `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, and `MatGetOwnershipRangesColumn()`.

4471:   The user MUST specify either the local or global matrix dimensions
4472:   (possibly both).

4474:   The parallel matrix is partitioned across processors such that the
4475:   first `m0` rows belong to process 0, the next `m1` rows belong to
4476:   process 1, the next `m2` rows belong to process 2, etc., where
4477:   `m0`, `m1`, `m2`... are the input parameter `m` on each MPI process. I.e., each MPI process stores
4478:   values corresponding to [m x N] submatrix.

4480:   The columns are logically partitioned with the n0 columns belonging
4481:   to 0th partition, the next n1 columns belonging to the next
4482:   partition etc.. where n0,n1,n2... are the input parameter 'n'.

4484:   The DIAGONAL portion of the local submatrix on any given processor
4485:   is the submatrix corresponding to the rows and columns m,n
4486:   corresponding to the given processor. i.e diagonal matrix on
4487:   process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4488:   etc. The remaining portion of the local submatrix [m x (N-n)]
4489:   constitute the OFF-DIAGONAL portion. The example below better
4490:   illustrates this concept. The two matrices, the DIAGONAL portion and
4491:   the OFF-DIAGONAL portion are each stored as `MATSEQAIJ` matrices.

4493:   For a square global matrix we define each processor's diagonal portion
4494:   to be its local rows and the corresponding columns (a square submatrix);
4495:   each processor's off-diagonal portion encompasses the remainder of the
4496:   local matrix (a rectangular submatrix).

4498:   If `o_nnz`, `d_nnz` are specified, then `o_nz`, and `d_nz` are ignored.

4500:   When calling this routine with a single process communicator, a matrix of
4501:   type `MATSEQAIJ` is returned.  If a matrix of type `MATMPIAIJ` is desired for this
4502:   type of communicator, use the construction mechanism
4503: .vb
4504:   MatCreate(..., &A);
4505:   MatSetType(A, MATMPIAIJ);
4506:   MatSetSizes(A, m, n, M, N);
4507:   MatMPIAIJSetPreallocation(A, ...);
4508: .ve

4510:   By default, this format uses inodes (identical nodes) when possible.
4511:   We search for consecutive rows with the same nonzero structure, thereby
4512:   reusing matrix information to achieve increased efficiency.

4514:   Example Usage:
4515:   Consider the following 8x8 matrix with 34 non-zero values, that is
4516:   assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4517:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4518:   as follows

4520: .vb
4521:             1  2  0  |  0  3  0  |  0  4
4522:     Proc0   0  5  6  |  7  0  0  |  8  0
4523:             9  0 10  | 11  0  0  | 12  0
4524:     -------------------------------------
4525:            13  0 14  | 15 16 17  |  0  0
4526:     Proc1   0 18  0  | 19 20 21  |  0  0
4527:             0  0  0  | 22 23  0  | 24  0
4528:     -------------------------------------
4529:     Proc2  25 26 27  |  0  0 28  | 29  0
4530:            30  0  0  | 31 32 33  |  0 34
4531: .ve

4533:   This can be represented as a collection of submatrices as

4535: .vb
4536:       A B C
4537:       D E F
4538:       G H I
4539: .ve

4541:   Where the submatrices A,B,C are owned by proc0, D,E,F are
4542:   owned by proc1, G,H,I are owned by proc2.

4544:   The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4545:   The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4546:   The 'M','N' parameters are 8,8, and have the same values on all procs.

4548:   The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4549:   submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4550:   corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4551:   Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4552:   part as `MATSEQAIJ` matrices. For example, proc1 will store [E] as a `MATSEQAIJ`
4553:   matrix, and [DF] as another SeqAIJ matrix.

4555:   When `d_nz`, `o_nz` parameters are specified, `d_nz` storage elements are
4556:   allocated for every row of the local DIAGONAL submatrix, and `o_nz`
4557:   storage locations are allocated for every row of the OFF-DIAGONAL submatrix.
4558:   One way to choose `d_nz` and `o_nz` is to use the maximum number of nonzeros over
4559:   the local rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4560:   In this case, the values of `d_nz`,`o_nz` are
4561: .vb
4562:      proc0  dnz = 2, o_nz = 2
4563:      proc1  dnz = 3, o_nz = 2
4564:      proc2  dnz = 1, o_nz = 4
4565: .ve
4566:   We are allocating m*(`d_nz`+`o_nz`) storage locations for every proc. This
4567:   translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4568:   for proc3. i.e we are using 12+15+10=37 storage locations to store
4569:   34 values.

4571:   When `d_nnz`, `o_nnz` parameters are specified, the storage is specified
4572:   for every row, corresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4573:   In the above case the values for d_nnz,o_nnz are
4574: .vb
4575:      proc0 d_nnz = [2,2,2] and o_nnz = [2,2,2]
4576:      proc1 d_nnz = [3,3,2] and o_nnz = [2,1,1]
4577:      proc2 d_nnz = [1,1]   and o_nnz = [4,4]
4578: .ve
4579:   Here the space allocated is sum of all the above values i.e 34, and
4580:   hence pre-allocation is perfect.

4582: .seealso: [](ch_matrices), `Mat`, [Sparse Matrix Creation](sec_matsparse), `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`,
4583:           `MATMPIAIJ`, `MatCreateMPIAIJWithArrays()`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`,
4584:           `MatGetOwnershipRangesColumn()`, `PetscLayout`
4585: @*/
4586: PetscErrorCode MatCreateAIJ(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscInt d_nz, const PetscInt d_nnz[], PetscInt o_nz, const PetscInt o_nnz[], Mat *A)
4587: {
4588:   PetscMPIInt size;

4590:   PetscFunctionBegin;
4591:   PetscCall(MatCreate(comm, A));
4592:   PetscCall(MatSetSizes(*A, m, n, M, N));
4593:   PetscCallMPI(MPI_Comm_size(comm, &size));
4594:   if (size > 1) {
4595:     PetscCall(MatSetType(*A, MATMPIAIJ));
4596:     PetscCall(MatMPIAIJSetPreallocation(*A, d_nz, d_nnz, o_nz, o_nnz));
4597:   } else {
4598:     PetscCall(MatSetType(*A, MATSEQAIJ));
4599:     PetscCall(MatSeqAIJSetPreallocation(*A, d_nz, d_nnz));
4600:   }
4601:   PetscFunctionReturn(PETSC_SUCCESS);
4602: }

4604: /*@C
4605:   MatMPIAIJGetSeqAIJ - Returns the local pieces of this distributed matrix

4607:   Not Collective

4609:   Input Parameter:
4610: . A - The `MATMPIAIJ` matrix

4612:   Output Parameters:
4613: + Ad     - The local diagonal block as a `MATSEQAIJ` matrix
4614: . Ao     - The local off-diagonal block as a `MATSEQAIJ` matrix
4615: - colmap - An array mapping local column numbers of `Ao` to global column numbers of the parallel matrix

4617:   Level: intermediate

4619:   Note:
4620:   The rows in `Ad` and `Ao` are in [0, Nr), where Nr is the number of local rows on this process. The columns
4621:   in `Ad` are in [0, Nc) where Nc is the number of local columns. The columns are `Ao` are in [0, Nco), where Nco is
4622:   the number of nonzero columns in the local off-diagonal piece of the matrix `A`. The array colmap maps these
4623:   local column numbers to global column numbers in the original matrix.

4625: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatMPIAIJGetLocalMat()`, `MatMPIAIJGetLocalMatCondensed()`, `MatCreateAIJ()`, `MATSEQAIJ`
4626: @*/
4627: PetscErrorCode MatMPIAIJGetSeqAIJ(Mat A, Mat *Ad, Mat *Ao, const PetscInt *colmap[])
4628: {
4629:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
4630:   PetscBool   flg;

4632:   PetscFunctionBegin;
4633:   PetscCall(PetscStrbeginswith(((PetscObject)A)->type_name, MATMPIAIJ, &flg));
4634:   PetscCheck(flg, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "This function requires a MATMPIAIJ matrix as input");
4635:   if (Ad) *Ad = a->A;
4636:   if (Ao) *Ao = a->B;
4637:   if (colmap) *colmap = a->garray;
4638:   PetscFunctionReturn(PETSC_SUCCESS);
4639: }

4641: PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm, Mat inmat, PetscInt n, MatReuse scall, Mat *outmat)
4642: {
4643:   PetscInt     m, N, i, rstart, nnz, Ii;
4644:   PetscInt    *indx;
4645:   PetscScalar *values;
4646:   MatType      rootType;

4648:   PetscFunctionBegin;
4649:   PetscCall(MatGetSize(inmat, &m, &N));
4650:   if (scall == MAT_INITIAL_MATRIX) { /* symbolic phase */
4651:     PetscInt *dnz, *onz, sum, bs, cbs;

4653:     if (n == PETSC_DECIDE) PetscCall(PetscSplitOwnership(comm, &n, &N));
4654:     /* Check sum(n) = N */
4655:     PetscCallMPI(MPIU_Allreduce(&n, &sum, 1, MPIU_INT, MPI_SUM, comm));
4656:     PetscCheck(sum == N, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Sum of local columns %" PetscInt_FMT " != global columns %" PetscInt_FMT, sum, N);

4658:     PetscCallMPI(MPI_Scan(&m, &rstart, 1, MPIU_INT, MPI_SUM, comm));
4659:     rstart -= m;

4661:     MatPreallocateBegin(comm, m, n, dnz, onz);
4662:     for (i = 0; i < m; i++) {
4663:       PetscCall(MatGetRow_SeqAIJ(inmat, i, &nnz, &indx, NULL));
4664:       PetscCall(MatPreallocateSet(i + rstart, nnz, indx, dnz, onz));
4665:       PetscCall(MatRestoreRow_SeqAIJ(inmat, i, &nnz, &indx, NULL));
4666:     }

4668:     PetscCall(MatCreate(comm, outmat));
4669:     PetscCall(MatSetSizes(*outmat, m, n, PETSC_DETERMINE, PETSC_DETERMINE));
4670:     PetscCall(MatGetBlockSizes(inmat, &bs, &cbs));
4671:     PetscCall(MatSetBlockSizes(*outmat, bs, cbs));
4672:     PetscCall(MatGetRootType_Private(inmat, &rootType));
4673:     PetscCall(MatSetType(*outmat, rootType));
4674:     PetscCall(MatSeqAIJSetPreallocation(*outmat, 0, dnz));
4675:     PetscCall(MatMPIAIJSetPreallocation(*outmat, 0, dnz, 0, onz));
4676:     MatPreallocateEnd(dnz, onz);
4677:     PetscCall(MatSetOption(*outmat, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
4678:   }

4680:   /* numeric phase */
4681:   PetscCall(MatGetOwnershipRange(*outmat, &rstart, NULL));
4682:   for (i = 0; i < m; i++) {
4683:     PetscCall(MatGetRow_SeqAIJ(inmat, i, &nnz, &indx, &values));
4684:     Ii = i + rstart;
4685:     PetscCall(MatSetValues(*outmat, 1, &Ii, nnz, indx, values, INSERT_VALUES));
4686:     PetscCall(MatRestoreRow_SeqAIJ(inmat, i, &nnz, &indx, &values));
4687:   }
4688:   PetscCall(MatAssemblyBegin(*outmat, MAT_FINAL_ASSEMBLY));
4689:   PetscCall(MatAssemblyEnd(*outmat, MAT_FINAL_ASSEMBLY));
4690:   PetscFunctionReturn(PETSC_SUCCESS);
4691: }

4693: static PetscErrorCode MatDestroy_MPIAIJ_SeqsToMPI(void **data)
4694: {
4695:   Mat_Merge_SeqsToMPI *merge = (Mat_Merge_SeqsToMPI *)*data;

4697:   PetscFunctionBegin;
4698:   if (!merge) PetscFunctionReturn(PETSC_SUCCESS);
4699:   PetscCall(PetscFree(merge->id_r));
4700:   PetscCall(PetscFree(merge->len_s));
4701:   PetscCall(PetscFree(merge->len_r));
4702:   PetscCall(PetscFree(merge->bi));
4703:   PetscCall(PetscFree(merge->bj));
4704:   PetscCall(PetscFree(merge->buf_ri[0]));
4705:   PetscCall(PetscFree(merge->buf_ri));
4706:   PetscCall(PetscFree(merge->buf_rj[0]));
4707:   PetscCall(PetscFree(merge->buf_rj));
4708:   PetscCall(PetscFree(merge->coi));
4709:   PetscCall(PetscFree(merge->coj));
4710:   PetscCall(PetscFree(merge->owners_co));
4711:   PetscCall(PetscLayoutDestroy(&merge->rowmap));
4712:   PetscCall(PetscFree(merge));
4713:   PetscFunctionReturn(PETSC_SUCCESS);
4714: }

4716: #include <../src/mat/utils/freespace.h>
4717: #include <petscbt.h>

4719: PetscErrorCode MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat, Mat mpimat)
4720: {
4721:   MPI_Comm             comm;
4722:   Mat_SeqAIJ          *a = (Mat_SeqAIJ *)seqmat->data;
4723:   PetscMPIInt          size, rank, taga, *len_s;
4724:   PetscInt             N = mpimat->cmap->N, i, j, *owners, *ai = a->i, *aj, m;
4725:   PetscMPIInt          proc, k;
4726:   PetscInt           **buf_ri, **buf_rj;
4727:   PetscInt             anzi, *bj_i, *bi, *bj, arow, bnzi, nextaj;
4728:   PetscInt             nrows, **buf_ri_k, **nextrow, **nextai;
4729:   MPI_Request         *s_waits, *r_waits;
4730:   MPI_Status          *status;
4731:   const MatScalar     *aa, *a_a;
4732:   MatScalar          **abuf_r, *ba_i;
4733:   Mat_Merge_SeqsToMPI *merge;
4734:   PetscContainer       container;

4736:   PetscFunctionBegin;
4737:   PetscCall(PetscObjectGetComm((PetscObject)mpimat, &comm));
4738:   PetscCall(PetscLogEventBegin(MAT_Seqstompinum, seqmat, 0, 0, 0));

4740:   PetscCallMPI(MPI_Comm_size(comm, &size));
4741:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

4743:   PetscCall(PetscObjectQuery((PetscObject)mpimat, "MatMergeSeqsToMPI", (PetscObject *)&container));
4744:   PetscCheck(container, PetscObjectComm((PetscObject)mpimat), PETSC_ERR_PLIB, "Mat not created from MatCreateMPIAIJSumSeqAIJSymbolic");
4745:   PetscCall(PetscContainerGetPointer(container, (void **)&merge));
4746:   PetscCall(MatSeqAIJGetArrayRead(seqmat, &a_a));
4747:   aa = a_a;

4749:   bi     = merge->bi;
4750:   bj     = merge->bj;
4751:   buf_ri = merge->buf_ri;
4752:   buf_rj = merge->buf_rj;

4754:   PetscCall(PetscMalloc1(size, &status));
4755:   owners = merge->rowmap->range;
4756:   len_s  = merge->len_s;

4758:   /* send and recv matrix values */
4759:   PetscCall(PetscObjectGetNewTag((PetscObject)mpimat, &taga));
4760:   PetscCall(PetscPostIrecvScalar(comm, taga, merge->nrecv, merge->id_r, merge->len_r, &abuf_r, &r_waits));

4762:   PetscCall(PetscMalloc1(merge->nsend + 1, &s_waits));
4763:   for (proc = 0, k = 0; proc < size; proc++) {
4764:     if (!len_s[proc]) continue;
4765:     i = owners[proc];
4766:     PetscCallMPI(MPIU_Isend(aa + ai[i], len_s[proc], MPIU_MATSCALAR, proc, taga, comm, s_waits + k));
4767:     k++;
4768:   }

4770:   if (merge->nrecv) PetscCallMPI(MPI_Waitall(merge->nrecv, r_waits, status));
4771:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, s_waits, status));
4772:   PetscCall(PetscFree(status));

4774:   PetscCall(PetscFree(s_waits));
4775:   PetscCall(PetscFree(r_waits));

4777:   /* insert mat values of mpimat */
4778:   PetscCall(PetscMalloc1(N, &ba_i));
4779:   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextai));

4781:   for (k = 0; k < merge->nrecv; k++) {
4782:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4783:     nrows       = *buf_ri_k[k];
4784:     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
4785:     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
4786:   }

4788:   /* set values of ba */
4789:   m = merge->rowmap->n;
4790:   for (i = 0; i < m; i++) {
4791:     arow = owners[rank] + i;
4792:     bj_i = bj + bi[i]; /* col indices of the i-th row of mpimat */
4793:     bnzi = bi[i + 1] - bi[i];
4794:     PetscCall(PetscArrayzero(ba_i, bnzi));

4796:     /* add local non-zero vals of this proc's seqmat into ba */
4797:     anzi   = ai[arow + 1] - ai[arow];
4798:     aj     = a->j + ai[arow];
4799:     aa     = a_a + ai[arow];
4800:     nextaj = 0;
4801:     for (j = 0; nextaj < anzi; j++) {
4802:       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4803:         ba_i[j] += aa[nextaj++];
4804:       }
4805:     }

4807:     /* add received vals into ba */
4808:     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
4809:       /* i-th row */
4810:       if (i == *nextrow[k]) {
4811:         anzi   = *(nextai[k] + 1) - *nextai[k];
4812:         aj     = buf_rj[k] + *nextai[k];
4813:         aa     = abuf_r[k] + *nextai[k];
4814:         nextaj = 0;
4815:         for (j = 0; nextaj < anzi; j++) {
4816:           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4817:             ba_i[j] += aa[nextaj++];
4818:           }
4819:         }
4820:         nextrow[k]++;
4821:         nextai[k]++;
4822:       }
4823:     }
4824:     PetscCall(MatSetValues(mpimat, 1, &arow, bnzi, bj_i, ba_i, INSERT_VALUES));
4825:   }
4826:   PetscCall(MatSeqAIJRestoreArrayRead(seqmat, &a_a));
4827:   PetscCall(MatAssemblyBegin(mpimat, MAT_FINAL_ASSEMBLY));
4828:   PetscCall(MatAssemblyEnd(mpimat, MAT_FINAL_ASSEMBLY));

4830:   PetscCall(PetscFree(abuf_r[0]));
4831:   PetscCall(PetscFree(abuf_r));
4832:   PetscCall(PetscFree(ba_i));
4833:   PetscCall(PetscFree3(buf_ri_k, nextrow, nextai));
4834:   PetscCall(PetscLogEventEnd(MAT_Seqstompinum, seqmat, 0, 0, 0));
4835:   PetscFunctionReturn(PETSC_SUCCESS);
4836: }

4838: PetscErrorCode MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm, Mat seqmat, PetscInt m, PetscInt n, Mat *mpimat)
4839: {
4840:   Mat                  B_mpi;
4841:   Mat_SeqAIJ          *a = (Mat_SeqAIJ *)seqmat->data;
4842:   PetscMPIInt          size, rank, tagi, tagj, *len_s, *len_si, *len_ri;
4843:   PetscInt           **buf_rj, **buf_ri, **buf_ri_k;
4844:   PetscInt             M = seqmat->rmap->n, N = seqmat->cmap->n, i, *owners, *ai = a->i, *aj = a->j;
4845:   PetscInt             len, *dnz, *onz, bs, cbs;
4846:   PetscInt             k, anzi, *bi, *bj, *lnk, nlnk, arow, bnzi;
4847:   PetscInt             nrows, *buf_s, *buf_si, *buf_si_i, **nextrow, **nextai;
4848:   MPI_Request         *si_waits, *sj_waits, *ri_waits, *rj_waits;
4849:   MPI_Status          *status;
4850:   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
4851:   PetscBT              lnkbt;
4852:   Mat_Merge_SeqsToMPI *merge;
4853:   PetscContainer       container;

4855:   PetscFunctionBegin;
4856:   PetscCall(PetscLogEventBegin(MAT_Seqstompisym, seqmat, 0, 0, 0));

4858:   /* make sure it is a PETSc comm */
4859:   PetscCall(PetscCommDuplicate(comm, &comm, NULL));
4860:   PetscCallMPI(MPI_Comm_size(comm, &size));
4861:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

4863:   PetscCall(PetscNew(&merge));
4864:   PetscCall(PetscMalloc1(size, &status));

4866:   /* determine row ownership */
4867:   PetscCall(PetscLayoutCreate(comm, &merge->rowmap));
4868:   PetscCall(PetscLayoutSetLocalSize(merge->rowmap, m));
4869:   PetscCall(PetscLayoutSetSize(merge->rowmap, M));
4870:   PetscCall(PetscLayoutSetBlockSize(merge->rowmap, 1));
4871:   PetscCall(PetscLayoutSetUp(merge->rowmap));
4872:   PetscCall(PetscMalloc1(size, &len_si));
4873:   PetscCall(PetscMalloc1(size, &merge->len_s));

4875:   m      = merge->rowmap->n;
4876:   owners = merge->rowmap->range;

4878:   /* determine the number of messages to send, their lengths */
4879:   len_s = merge->len_s;

4881:   len          = 0; /* length of buf_si[] */
4882:   merge->nsend = 0;
4883:   for (PetscMPIInt proc = 0; proc < size; proc++) {
4884:     len_si[proc] = 0;
4885:     if (proc == rank) {
4886:       len_s[proc] = 0;
4887:     } else {
4888:       PetscCall(PetscMPIIntCast(owners[proc + 1] - owners[proc] + 1, &len_si[proc]));
4889:       PetscCall(PetscMPIIntCast(ai[owners[proc + 1]] - ai[owners[proc]], &len_s[proc])); /* num of rows to be sent to [proc] */
4890:     }
4891:     if (len_s[proc]) {
4892:       merge->nsend++;
4893:       nrows = 0;
4894:       for (i = owners[proc]; i < owners[proc + 1]; i++) {
4895:         if (ai[i + 1] > ai[i]) nrows++;
4896:       }
4897:       PetscCall(PetscMPIIntCast(2 * (nrows + 1), &len_si[proc]));
4898:       len += len_si[proc];
4899:     }
4900:   }

4902:   /* determine the number and length of messages to receive for ij-structure */
4903:   PetscCall(PetscGatherNumberOfMessages(comm, NULL, len_s, &merge->nrecv));
4904:   PetscCall(PetscGatherMessageLengths2(comm, merge->nsend, merge->nrecv, len_s, len_si, &merge->id_r, &merge->len_r, &len_ri));

4906:   /* post the Irecv of j-structure */
4907:   PetscCall(PetscCommGetNewTag(comm, &tagj));
4908:   PetscCall(PetscPostIrecvInt(comm, tagj, merge->nrecv, merge->id_r, merge->len_r, &buf_rj, &rj_waits));

4910:   /* post the Isend of j-structure */
4911:   PetscCall(PetscMalloc2(merge->nsend, &si_waits, merge->nsend, &sj_waits));

4913:   for (PetscMPIInt proc = 0, k = 0; proc < size; proc++) {
4914:     if (!len_s[proc]) continue;
4915:     i = owners[proc];
4916:     PetscCallMPI(MPIU_Isend(aj + ai[i], len_s[proc], MPIU_INT, proc, tagj, comm, sj_waits + k));
4917:     k++;
4918:   }

4920:   /* receives and sends of j-structure are complete */
4921:   if (merge->nrecv) PetscCallMPI(MPI_Waitall(merge->nrecv, rj_waits, status));
4922:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, sj_waits, status));

4924:   /* send and recv i-structure */
4925:   PetscCall(PetscCommGetNewTag(comm, &tagi));
4926:   PetscCall(PetscPostIrecvInt(comm, tagi, merge->nrecv, merge->id_r, len_ri, &buf_ri, &ri_waits));

4928:   PetscCall(PetscMalloc1(len + 1, &buf_s));
4929:   buf_si = buf_s; /* points to the beginning of k-th msg to be sent */
4930:   for (PetscMPIInt proc = 0, k = 0; proc < size; proc++) {
4931:     if (!len_s[proc]) continue;
4932:     /* form outgoing message for i-structure:
4933:          buf_si[0]:                 nrows to be sent
4934:                [1:nrows]:           row index (global)
4935:                [nrows+1:2*nrows+1]: i-structure index
4936:     */
4937:     nrows       = len_si[proc] / 2 - 1;
4938:     buf_si_i    = buf_si + nrows + 1;
4939:     buf_si[0]   = nrows;
4940:     buf_si_i[0] = 0;
4941:     nrows       = 0;
4942:     for (i = owners[proc]; i < owners[proc + 1]; i++) {
4943:       anzi = ai[i + 1] - ai[i];
4944:       if (anzi) {
4945:         buf_si_i[nrows + 1] = buf_si_i[nrows] + anzi; /* i-structure */
4946:         buf_si[nrows + 1]   = i - owners[proc];       /* local row index */
4947:         nrows++;
4948:       }
4949:     }
4950:     PetscCallMPI(MPIU_Isend(buf_si, len_si[proc], MPIU_INT, proc, tagi, comm, si_waits + k));
4951:     k++;
4952:     buf_si += len_si[proc];
4953:   }

4955:   if (merge->nrecv) PetscCallMPI(MPI_Waitall(merge->nrecv, ri_waits, status));
4956:   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, si_waits, status));

4958:   PetscCall(PetscInfo(seqmat, "nsend: %d, nrecv: %d\n", merge->nsend, merge->nrecv));
4959:   for (i = 0; i < merge->nrecv; i++) PetscCall(PetscInfo(seqmat, "recv len_ri=%d, len_rj=%d from [%d]\n", len_ri[i], merge->len_r[i], merge->id_r[i]));

4961:   PetscCall(PetscFree(len_si));
4962:   PetscCall(PetscFree(len_ri));
4963:   PetscCall(PetscFree(rj_waits));
4964:   PetscCall(PetscFree2(si_waits, sj_waits));
4965:   PetscCall(PetscFree(ri_waits));
4966:   PetscCall(PetscFree(buf_s));
4967:   PetscCall(PetscFree(status));

4969:   /* compute a local seq matrix in each processor */
4970:   /* allocate bi array and free space for accumulating nonzero column info */
4971:   PetscCall(PetscMalloc1(m + 1, &bi));
4972:   bi[0] = 0;

4974:   /* create and initialize a linked list */
4975:   nlnk = N + 1;
4976:   PetscCall(PetscLLCreate(N, N, nlnk, lnk, lnkbt));

4978:   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4979:   len = ai[owners[rank + 1]] - ai[owners[rank]];
4980:   PetscCall(PetscFreeSpaceGet(PetscIntMultTruncate(2, len) + 1, &free_space));

4982:   current_space = free_space;

4984:   /* determine symbolic info for each local row */
4985:   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextai));

4987:   for (k = 0; k < merge->nrecv; k++) {
4988:     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4989:     nrows       = *buf_ri_k[k];
4990:     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
4991:     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
4992:   }

4994:   MatPreallocateBegin(comm, m, n, dnz, onz);
4995:   len = 0;
4996:   for (i = 0; i < m; i++) {
4997:     bnzi = 0;
4998:     /* add local non-zero cols of this proc's seqmat into lnk */
4999:     arow = owners[rank] + i;
5000:     anzi = ai[arow + 1] - ai[arow];
5001:     aj   = a->j + ai[arow];
5002:     PetscCall(PetscLLAddSorted(anzi, aj, N, &nlnk, lnk, lnkbt));
5003:     bnzi += nlnk;
5004:     /* add received col data into lnk */
5005:     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
5006:       if (i == *nextrow[k]) {            /* i-th row */
5007:         anzi = *(nextai[k] + 1) - *nextai[k];
5008:         aj   = buf_rj[k] + *nextai[k];
5009:         PetscCall(PetscLLAddSorted(anzi, aj, N, &nlnk, lnk, lnkbt));
5010:         bnzi += nlnk;
5011:         nextrow[k]++;
5012:         nextai[k]++;
5013:       }
5014:     }
5015:     if (len < bnzi) len = bnzi; /* =max(bnzi) */

5017:     /* if free space is not available, make more free space */
5018:     if (current_space->local_remaining < bnzi) PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(bnzi, current_space->total_array_size), &current_space));
5019:     /* copy data into free space, then initialize lnk */
5020:     PetscCall(PetscLLClean(N, N, bnzi, lnk, current_space->array, lnkbt));
5021:     PetscCall(MatPreallocateSet(i + owners[rank], bnzi, current_space->array, dnz, onz));

5023:     current_space->array += bnzi;
5024:     current_space->local_used += bnzi;
5025:     current_space->local_remaining -= bnzi;

5027:     bi[i + 1] = bi[i] + bnzi;
5028:   }

5030:   PetscCall(PetscFree3(buf_ri_k, nextrow, nextai));

5032:   PetscCall(PetscMalloc1(bi[m] + 1, &bj));
5033:   PetscCall(PetscFreeSpaceContiguous(&free_space, bj));
5034:   PetscCall(PetscLLDestroy(lnk, lnkbt));

5036:   /* create symbolic parallel matrix B_mpi */
5037:   PetscCall(MatGetBlockSizes(seqmat, &bs, &cbs));
5038:   PetscCall(MatCreate(comm, &B_mpi));
5039:   if (n == PETSC_DECIDE) {
5040:     PetscCall(MatSetSizes(B_mpi, m, n, PETSC_DETERMINE, N));
5041:   } else {
5042:     PetscCall(MatSetSizes(B_mpi, m, n, PETSC_DETERMINE, PETSC_DETERMINE));
5043:   }
5044:   PetscCall(MatSetBlockSizes(B_mpi, bs, cbs));
5045:   PetscCall(MatSetType(B_mpi, MATMPIAIJ));
5046:   PetscCall(MatMPIAIJSetPreallocation(B_mpi, 0, dnz, 0, onz));
5047:   MatPreallocateEnd(dnz, onz);
5048:   PetscCall(MatSetOption(B_mpi, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));

5050:   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
5051:   B_mpi->assembled = PETSC_FALSE;
5052:   merge->bi        = bi;
5053:   merge->bj        = bj;
5054:   merge->buf_ri    = buf_ri;
5055:   merge->buf_rj    = buf_rj;
5056:   merge->coi       = NULL;
5057:   merge->coj       = NULL;
5058:   merge->owners_co = NULL;

5060:   PetscCall(PetscCommDestroy(&comm));

5062:   /* attach the supporting struct to B_mpi for reuse */
5063:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
5064:   PetscCall(PetscContainerSetPointer(container, merge));
5065:   PetscCall(PetscContainerSetCtxDestroy(container, MatDestroy_MPIAIJ_SeqsToMPI));
5066:   PetscCall(PetscObjectCompose((PetscObject)B_mpi, "MatMergeSeqsToMPI", (PetscObject)container));
5067:   PetscCall(PetscContainerDestroy(&container));
5068:   *mpimat = B_mpi;

5070:   PetscCall(PetscLogEventEnd(MAT_Seqstompisym, seqmat, 0, 0, 0));
5071:   PetscFunctionReturn(PETSC_SUCCESS);
5072: }

5074: /*@
5075:   MatCreateMPIAIJSumSeqAIJ - Creates a `MATMPIAIJ` matrix by adding sequential
5076:   matrices from each processor

5078:   Collective

5080:   Input Parameters:
5081: + comm   - the communicators the parallel matrix will live on
5082: . seqmat - the input sequential matrices
5083: . m      - number of local rows (or `PETSC_DECIDE`)
5084: . n      - number of local columns (or `PETSC_DECIDE`)
5085: - scall  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

5087:   Output Parameter:
5088: . mpimat - the parallel matrix generated

5090:   Level: advanced

5092:   Note:
5093:   The dimensions of the sequential matrix in each processor MUST be the same.
5094:   The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
5095:   destroyed when `mpimat` is destroyed. Call `PetscObjectQuery()` to access `seqmat`.

5097: .seealso: [](ch_matrices), `Mat`, `MatCreateAIJ()`
5098: @*/
5099: PetscErrorCode MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm, Mat seqmat, PetscInt m, PetscInt n, MatReuse scall, Mat *mpimat)
5100: {
5101:   PetscMPIInt size;

5103:   PetscFunctionBegin;
5104:   PetscCallMPI(MPI_Comm_size(comm, &size));
5105:   if (size == 1) {
5106:     PetscCall(PetscLogEventBegin(MAT_Seqstompi, seqmat, 0, 0, 0));
5107:     if (scall == MAT_INITIAL_MATRIX) {
5108:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
5109:     } else {
5110:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
5111:     }
5112:     PetscCall(PetscLogEventEnd(MAT_Seqstompi, seqmat, 0, 0, 0));
5113:     PetscFunctionReturn(PETSC_SUCCESS);
5114:   }
5115:   PetscCall(PetscLogEventBegin(MAT_Seqstompi, seqmat, 0, 0, 0));
5116:   if (scall == MAT_INITIAL_MATRIX) PetscCall(MatCreateMPIAIJSumSeqAIJSymbolic(comm, seqmat, m, n, mpimat));
5117:   PetscCall(MatCreateMPIAIJSumSeqAIJNumeric(seqmat, *mpimat));
5118:   PetscCall(PetscLogEventEnd(MAT_Seqstompi, seqmat, 0, 0, 0));
5119:   PetscFunctionReturn(PETSC_SUCCESS);
5120: }

5122: /*@
5123:   MatAIJGetLocalMat - Creates a `MATSEQAIJ` from a `MATAIJ` matrix.

5125:   Not Collective

5127:   Input Parameter:
5128: . A - the matrix

5130:   Output Parameter:
5131: . A_loc - the local sequential matrix generated

5133:   Level: developer

5135:   Notes:
5136:   The matrix is created by taking `A`'s local rows and putting them into a sequential matrix
5137:   with `mlocal` rows and `n` columns. Where `mlocal` is obtained with `MatGetLocalSize()` and
5138:   `n` is the global column count obtained with `MatGetSize()`

5140:   In other words combines the two parts of a parallel `MATMPIAIJ` matrix on each process to a single matrix.

5142:   For parallel matrices this creates an entirely new matrix. If the matrix is sequential it merely increases the reference count.

5144:   Destroy the matrix with `MatDestroy()`

5146: .seealso: [](ch_matrices), `Mat`, `MatMPIAIJGetLocalMat()`
5147: @*/
5148: PetscErrorCode MatAIJGetLocalMat(Mat A, Mat *A_loc)
5149: {
5150:   PetscBool mpi;

5152:   PetscFunctionBegin;
5153:   PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMPIAIJ, &mpi));
5154:   if (mpi) {
5155:     PetscCall(MatMPIAIJGetLocalMat(A, MAT_INITIAL_MATRIX, A_loc));
5156:   } else {
5157:     *A_loc = A;
5158:     PetscCall(PetscObjectReference((PetscObject)*A_loc));
5159:   }
5160:   PetscFunctionReturn(PETSC_SUCCESS);
5161: }

5163: /*@
5164:   MatMPIAIJGetLocalMat - Creates a `MATSEQAIJ` from a `MATMPIAIJ` matrix.

5166:   Not Collective

5168:   Input Parameters:
5169: + A     - the matrix
5170: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

5172:   Output Parameter:
5173: . A_loc - the local sequential matrix generated

5175:   Level: developer

5177:   Notes:
5178:   The matrix is created by taking all `A`'s local rows and putting them into a sequential
5179:   matrix with `mlocal` rows and `n` columns.`mlocal` is the row count obtained with
5180:   `MatGetLocalSize()` and `n` is the global column count obtained with `MatGetSize()`.

5182:   In other words combines the two parts of a parallel `MATMPIAIJ` matrix on each process to a single matrix.

5184:   When `A` is sequential and `MAT_INITIAL_MATRIX` is requested, the matrix returned is the diagonal part of `A` (which contains the entire matrix),
5185:   with its reference count increased by one. Hence changing values of `A_loc` changes `A`. If `MAT_REUSE_MATRIX` is requested on a sequential matrix
5186:   then `MatCopy`(Adiag,*`A_loc`,`SAME_NONZERO_PATTERN`) is called to fill `A_loc`. Thus one can preallocate the appropriate sequential matrix `A_loc`
5187:   and then call this routine with `MAT_REUSE_MATRIX`. In this case, one can modify the values of `A_loc` without affecting the original sequential matrix.

5189: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatGetOwnershipRange()`, `MatMPIAIJGetLocalMatCondensed()`, `MatMPIAIJGetLocalMatMerge()`
5190: @*/
5191: PetscErrorCode MatMPIAIJGetLocalMat(Mat A, MatReuse scall, Mat *A_loc)
5192: {
5193:   Mat_MPIAIJ        *mpimat = (Mat_MPIAIJ *)A->data;
5194:   Mat_SeqAIJ        *mat, *a, *b;
5195:   PetscInt          *ai, *aj, *bi, *bj, *cmap = mpimat->garray;
5196:   const PetscScalar *aa, *ba, *aav, *bav;
5197:   PetscScalar       *ca, *cam;
5198:   PetscMPIInt        size;
5199:   PetscInt           am = A->rmap->n, i, j, k, cstart = A->cmap->rstart;
5200:   PetscInt          *ci, *cj, col, ncols_d, ncols_o, jo;
5201:   PetscBool          match;

5203:   PetscFunctionBegin;
5204:   PetscCall(PetscStrbeginswith(((PetscObject)A)->type_name, MATMPIAIJ, &match));
5205:   PetscCheck(match, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Requires MATMPIAIJ matrix as input");
5206:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
5207:   if (size == 1) {
5208:     if (scall == MAT_INITIAL_MATRIX) {
5209:       PetscCall(PetscObjectReference((PetscObject)mpimat->A));
5210:       *A_loc = mpimat->A;
5211:     } else if (scall == MAT_REUSE_MATRIX) {
5212:       PetscCall(MatCopy(mpimat->A, *A_loc, SAME_NONZERO_PATTERN));
5213:     }
5214:     PetscFunctionReturn(PETSC_SUCCESS);
5215:   }

5217:   PetscCall(PetscLogEventBegin(MAT_Getlocalmat, A, 0, 0, 0));
5218:   a  = (Mat_SeqAIJ *)mpimat->A->data;
5219:   b  = (Mat_SeqAIJ *)mpimat->B->data;
5220:   ai = a->i;
5221:   aj = a->j;
5222:   bi = b->i;
5223:   bj = b->j;
5224:   PetscCall(MatSeqAIJGetArrayRead(mpimat->A, &aav));
5225:   PetscCall(MatSeqAIJGetArrayRead(mpimat->B, &bav));
5226:   aa = aav;
5227:   ba = bav;
5228:   if (scall == MAT_INITIAL_MATRIX) {
5229:     PetscCall(PetscMalloc1(1 + am, &ci));
5230:     ci[0] = 0;
5231:     for (i = 0; i < am; i++) ci[i + 1] = ci[i] + (ai[i + 1] - ai[i]) + (bi[i + 1] - bi[i]);
5232:     PetscCall(PetscMalloc1(1 + ci[am], &cj));
5233:     PetscCall(PetscMalloc1(1 + ci[am], &ca));
5234:     k = 0;
5235:     for (i = 0; i < am; i++) {
5236:       ncols_o = bi[i + 1] - bi[i];
5237:       ncols_d = ai[i + 1] - ai[i];
5238:       /* off-diagonal portion of A */
5239:       for (jo = 0; jo < ncols_o; jo++) {
5240:         col = cmap[*bj];
5241:         if (col >= cstart) break;
5242:         cj[k] = col;
5243:         bj++;
5244:         ca[k++] = *ba++;
5245:       }
5246:       /* diagonal portion of A */
5247:       for (j = 0; j < ncols_d; j++) {
5248:         cj[k]   = cstart + *aj++;
5249:         ca[k++] = *aa++;
5250:       }
5251:       /* off-diagonal portion of A */
5252:       for (j = jo; j < ncols_o; j++) {
5253:         cj[k]   = cmap[*bj++];
5254:         ca[k++] = *ba++;
5255:       }
5256:     }
5257:     /* put together the new matrix */
5258:     PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, am, A->cmap->N, ci, cj, ca, A_loc));
5259:     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5260:     /* Since these are PETSc arrays, change flags to free them as necessary. */
5261:     mat          = (Mat_SeqAIJ *)(*A_loc)->data;
5262:     mat->free_a  = PETSC_TRUE;
5263:     mat->free_ij = PETSC_TRUE;
5264:     mat->nonew   = 0;
5265:   } else if (scall == MAT_REUSE_MATRIX) {
5266:     mat = (Mat_SeqAIJ *)(*A_loc)->data;
5267:     ci  = mat->i;
5268:     cj  = mat->j;
5269:     PetscCall(MatSeqAIJGetArrayWrite(*A_loc, &cam));
5270:     for (i = 0; i < am; i++) {
5271:       /* off-diagonal portion of A */
5272:       ncols_o = bi[i + 1] - bi[i];
5273:       for (jo = 0; jo < ncols_o; jo++) {
5274:         col = cmap[*bj];
5275:         if (col >= cstart) break;
5276:         *cam++ = *ba++;
5277:         bj++;
5278:       }
5279:       /* diagonal portion of A */
5280:       ncols_d = ai[i + 1] - ai[i];
5281:       for (j = 0; j < ncols_d; j++) *cam++ = *aa++;
5282:       /* off-diagonal portion of A */
5283:       for (j = jo; j < ncols_o; j++) {
5284:         *cam++ = *ba++;
5285:         bj++;
5286:       }
5287:     }
5288:     PetscCall(MatSeqAIJRestoreArrayWrite(*A_loc, &cam));
5289:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid MatReuse %d", (int)scall);
5290:   PetscCall(MatSeqAIJRestoreArrayRead(mpimat->A, &aav));
5291:   PetscCall(MatSeqAIJRestoreArrayRead(mpimat->B, &bav));
5292:   PetscCall(PetscLogEventEnd(MAT_Getlocalmat, A, 0, 0, 0));
5293:   PetscFunctionReturn(PETSC_SUCCESS);
5294: }

5296: /*@
5297:   MatMPIAIJGetLocalMatMerge - Creates a `MATSEQAIJ` from a `MATMPIAIJ` matrix by taking all its local rows and putting them into a sequential matrix with
5298:   mlocal rows and n columns. Where n is the sum of the number of columns of the diagonal and off-diagonal part

5300:   Not Collective

5302:   Input Parameters:
5303: + A     - the matrix
5304: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

5306:   Output Parameters:
5307: + glob  - sequential `IS` with global indices associated with the columns of the local sequential matrix generated (can be `NULL`)
5308: - A_loc - the local sequential matrix generated

5310:   Level: developer

5312:   Note:
5313:   This is different from `MatMPIAIJGetLocalMat()` since the first columns in the returning matrix are those associated with the diagonal
5314:   part, then those associated with the off-diagonal part (in its local ordering)

5316: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatGetOwnershipRange()`, `MatMPIAIJGetLocalMat()`, `MatMPIAIJGetLocalMatCondensed()`
5317: @*/
5318: PetscErrorCode MatMPIAIJGetLocalMatMerge(Mat A, MatReuse scall, IS *glob, Mat *A_loc)
5319: {
5320:   Mat             Ao, Ad;
5321:   const PetscInt *cmap;
5322:   PetscMPIInt     size;
5323:   PetscErrorCode (*f)(Mat, MatReuse, IS *, Mat *);

5325:   PetscFunctionBegin;
5326:   PetscCall(MatMPIAIJGetSeqAIJ(A, &Ad, &Ao, &cmap));
5327:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
5328:   if (size == 1) {
5329:     if (scall == MAT_INITIAL_MATRIX) {
5330:       PetscCall(PetscObjectReference((PetscObject)Ad));
5331:       *A_loc = Ad;
5332:     } else if (scall == MAT_REUSE_MATRIX) {
5333:       PetscCall(MatCopy(Ad, *A_loc, SAME_NONZERO_PATTERN));
5334:     }
5335:     if (glob) PetscCall(ISCreateStride(PetscObjectComm((PetscObject)Ad), Ad->cmap->n, Ad->cmap->rstart, 1, glob));
5336:     PetscFunctionReturn(PETSC_SUCCESS);
5337:   }
5338:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatMPIAIJGetLocalMatMerge_C", &f));
5339:   PetscCall(PetscLogEventBegin(MAT_Getlocalmat, A, 0, 0, 0));
5340:   if (f) {
5341:     PetscCall((*f)(A, scall, glob, A_loc));
5342:   } else {
5343:     Mat_SeqAIJ        *a = (Mat_SeqAIJ *)Ad->data;
5344:     Mat_SeqAIJ        *b = (Mat_SeqAIJ *)Ao->data;
5345:     Mat_SeqAIJ        *c;
5346:     PetscInt          *ai = a->i, *aj = a->j;
5347:     PetscInt          *bi = b->i, *bj = b->j;
5348:     PetscInt          *ci, *cj;
5349:     const PetscScalar *aa, *ba;
5350:     PetscScalar       *ca;
5351:     PetscInt           i, j, am, dn, on;

5353:     PetscCall(MatGetLocalSize(Ad, &am, &dn));
5354:     PetscCall(MatGetLocalSize(Ao, NULL, &on));
5355:     PetscCall(MatSeqAIJGetArrayRead(Ad, &aa));
5356:     PetscCall(MatSeqAIJGetArrayRead(Ao, &ba));
5357:     if (scall == MAT_INITIAL_MATRIX) {
5358:       PetscInt k;
5359:       PetscCall(PetscMalloc1(1 + am, &ci));
5360:       PetscCall(PetscMalloc1(ai[am] + bi[am], &cj));
5361:       PetscCall(PetscMalloc1(ai[am] + bi[am], &ca));
5362:       ci[0] = 0;
5363:       for (i = 0, k = 0; i < am; i++) {
5364:         const PetscInt ncols_o = bi[i + 1] - bi[i];
5365:         const PetscInt ncols_d = ai[i + 1] - ai[i];
5366:         ci[i + 1]              = ci[i] + ncols_o + ncols_d;
5367:         /* diagonal portion of A */
5368:         for (j = 0; j < ncols_d; j++, k++) {
5369:           cj[k] = *aj++;
5370:           ca[k] = *aa++;
5371:         }
5372:         /* off-diagonal portion of A */
5373:         for (j = 0; j < ncols_o; j++, k++) {
5374:           cj[k] = dn + *bj++;
5375:           ca[k] = *ba++;
5376:         }
5377:       }
5378:       /* put together the new matrix */
5379:       PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, am, dn + on, ci, cj, ca, A_loc));
5380:       /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5381:       /* Since these are PETSc arrays, change flags to free them as necessary. */
5382:       c          = (Mat_SeqAIJ *)(*A_loc)->data;
5383:       c->free_a  = PETSC_TRUE;
5384:       c->free_ij = PETSC_TRUE;
5385:       c->nonew   = 0;
5386:       PetscCall(MatSetType(*A_loc, ((PetscObject)Ad)->type_name));
5387:     } else if (scall == MAT_REUSE_MATRIX) {
5388:       PetscCall(MatSeqAIJGetArrayWrite(*A_loc, &ca));
5389:       for (i = 0; i < am; i++) {
5390:         const PetscInt ncols_d = ai[i + 1] - ai[i];
5391:         const PetscInt ncols_o = bi[i + 1] - bi[i];
5392:         /* diagonal portion of A */
5393:         for (j = 0; j < ncols_d; j++) *ca++ = *aa++;
5394:         /* off-diagonal portion of A */
5395:         for (j = 0; j < ncols_o; j++) *ca++ = *ba++;
5396:       }
5397:       PetscCall(MatSeqAIJRestoreArrayWrite(*A_loc, &ca));
5398:     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid MatReuse %d", (int)scall);
5399:     PetscCall(MatSeqAIJRestoreArrayRead(Ad, &aa));
5400:     PetscCall(MatSeqAIJRestoreArrayRead(Ao, &aa));
5401:     if (glob) {
5402:       PetscInt cst, *gidx;

5404:       PetscCall(MatGetOwnershipRangeColumn(A, &cst, NULL));
5405:       PetscCall(PetscMalloc1(dn + on, &gidx));
5406:       for (i = 0; i < dn; i++) gidx[i] = cst + i;
5407:       for (i = 0; i < on; i++) gidx[i + dn] = cmap[i];
5408:       PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)Ad), dn + on, gidx, PETSC_OWN_POINTER, glob));
5409:     }
5410:   }
5411:   PetscCall(PetscLogEventEnd(MAT_Getlocalmat, A, 0, 0, 0));
5412:   PetscFunctionReturn(PETSC_SUCCESS);
5413: }

5415: /*@C
5416:   MatMPIAIJGetLocalMatCondensed - Creates a `MATSEQAIJ` matrix from an `MATMPIAIJ` matrix by taking all its local rows and NON-ZERO columns

5418:   Not Collective

5420:   Input Parameters:
5421: + A     - the matrix
5422: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
5423: . row   - index set of rows to extract (or `NULL`)
5424: - col   - index set of columns to extract (or `NULL`)

5426:   Output Parameter:
5427: . A_loc - the local sequential matrix generated

5429:   Level: developer

5431: .seealso: [](ch_matrices), `Mat`, `MATMPIAIJ`, `MatGetOwnershipRange()`, `MatMPIAIJGetLocalMat()`
5432: @*/
5433: PetscErrorCode MatMPIAIJGetLocalMatCondensed(Mat A, MatReuse scall, IS *row, IS *col, Mat *A_loc)
5434: {
5435:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
5436:   PetscInt    i, start, end, ncols, nzA, nzB, *cmap, imark, *idx;
5437:   IS          isrowa, iscola;
5438:   Mat        *aloc;
5439:   PetscBool   match;

5441:   PetscFunctionBegin;
5442:   PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMPIAIJ, &match));
5443:   PetscCheck(match, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Requires MATMPIAIJ matrix as input");
5444:   PetscCall(PetscLogEventBegin(MAT_Getlocalmatcondensed, A, 0, 0, 0));
5445:   if (!row) {
5446:     start = A->rmap->rstart;
5447:     end   = A->rmap->rend;
5448:     PetscCall(ISCreateStride(PETSC_COMM_SELF, end - start, start, 1, &isrowa));
5449:   } else {
5450:     isrowa = *row;
5451:   }
5452:   if (!col) {
5453:     start = A->cmap->rstart;
5454:     cmap  = a->garray;
5455:     nzA   = a->A->cmap->n;
5456:     nzB   = a->B->cmap->n;
5457:     PetscCall(PetscMalloc1(nzA + nzB, &idx));
5458:     ncols = 0;
5459:     for (i = 0; i < nzB; i++) {
5460:       if (cmap[i] < start) idx[ncols++] = cmap[i];
5461:       else break;
5462:     }
5463:     imark = i;
5464:     for (i = 0; i < nzA; i++) idx[ncols++] = start + i;
5465:     for (i = imark; i < nzB; i++) idx[ncols++] = cmap[i];
5466:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, ncols, idx, PETSC_OWN_POINTER, &iscola));
5467:   } else {
5468:     iscola = *col;
5469:   }
5470:   if (scall != MAT_INITIAL_MATRIX) {
5471:     PetscCall(PetscMalloc1(1, &aloc));
5472:     aloc[0] = *A_loc;
5473:   }
5474:   PetscCall(MatCreateSubMatrices(A, 1, &isrowa, &iscola, scall, &aloc));
5475:   if (!col) { /* attach global id of condensed columns */
5476:     PetscCall(PetscObjectCompose((PetscObject)aloc[0], "_petsc_GetLocalMatCondensed_iscol", (PetscObject)iscola));
5477:   }
5478:   *A_loc = aloc[0];
5479:   PetscCall(PetscFree(aloc));
5480:   if (!row) PetscCall(ISDestroy(&isrowa));
5481:   if (!col) PetscCall(ISDestroy(&iscola));
5482:   PetscCall(PetscLogEventEnd(MAT_Getlocalmatcondensed, A, 0, 0, 0));
5483:   PetscFunctionReturn(PETSC_SUCCESS);
5484: }

5486: /*
5487:  * Create a sequential AIJ matrix based on row indices. a whole column is extracted once a row is matched.
5488:  * Row could be local or remote.The routine is designed to be scalable in memory so that nothing is based
5489:  * on a global size.
5490:  * */
5491: static PetscErrorCode MatCreateSeqSubMatrixWithRows_Private(Mat P, IS rows, Mat *P_oth)
5492: {
5493:   Mat_MPIAIJ            *p  = (Mat_MPIAIJ *)P->data;
5494:   Mat_SeqAIJ            *pd = (Mat_SeqAIJ *)p->A->data, *po = (Mat_SeqAIJ *)p->B->data, *p_oth;
5495:   PetscInt               plocalsize, nrows, *ilocal, *oilocal, i, lidx, *nrcols, *nlcols, ncol;
5496:   PetscMPIInt            owner;
5497:   PetscSFNode           *iremote, *oiremote;
5498:   const PetscInt        *lrowindices;
5499:   PetscSF                sf, osf;
5500:   PetscInt               pcstart, *roffsets, *loffsets, *pnnz, j;
5501:   PetscInt               ontotalcols, dntotalcols, ntotalcols, nout;
5502:   MPI_Comm               comm;
5503:   ISLocalToGlobalMapping mapping;
5504:   const PetscScalar     *pd_a, *po_a;

5506:   PetscFunctionBegin;
5507:   PetscCall(PetscObjectGetComm((PetscObject)P, &comm));
5508:   /* plocalsize is the number of roots
5509:    * nrows is the number of leaves
5510:    * */
5511:   PetscCall(MatGetLocalSize(P, &plocalsize, NULL));
5512:   PetscCall(ISGetLocalSize(rows, &nrows));
5513:   PetscCall(PetscCalloc1(nrows, &iremote));
5514:   PetscCall(ISGetIndices(rows, &lrowindices));
5515:   for (i = 0; i < nrows; i++) {
5516:     /* Find a remote index and an owner for a row
5517:      * The row could be local or remote
5518:      * */
5519:     owner = 0;
5520:     lidx  = 0;
5521:     PetscCall(PetscLayoutFindOwnerIndex(P->rmap, lrowindices[i], &owner, &lidx));
5522:     iremote[i].index = lidx;
5523:     iremote[i].rank  = owner;
5524:   }
5525:   /* Create SF to communicate how many nonzero columns for each row */
5526:   PetscCall(PetscSFCreate(comm, &sf));
5527:   /* SF will figure out the number of nonzero columns for each row, and their
5528:    * offsets
5529:    * */
5530:   PetscCall(PetscSFSetGraph(sf, plocalsize, nrows, NULL, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));
5531:   PetscCall(PetscSFSetFromOptions(sf));
5532:   PetscCall(PetscSFSetUp(sf));

5534:   PetscCall(PetscCalloc1(2 * (plocalsize + 1), &roffsets));
5535:   PetscCall(PetscCalloc1(2 * plocalsize, &nrcols));
5536:   PetscCall(PetscCalloc1(nrows, &pnnz));
5537:   roffsets[0] = 0;
5538:   roffsets[1] = 0;
5539:   for (i = 0; i < plocalsize; i++) {
5540:     /* diagonal */
5541:     nrcols[i * 2 + 0] = pd->i[i + 1] - pd->i[i];
5542:     /* off-diagonal */
5543:     nrcols[i * 2 + 1] = po->i[i + 1] - po->i[i];
5544:     /* compute offsets so that we relative location for each row */
5545:     roffsets[(i + 1) * 2 + 0] = roffsets[i * 2 + 0] + nrcols[i * 2 + 0];
5546:     roffsets[(i + 1) * 2 + 1] = roffsets[i * 2 + 1] + nrcols[i * 2 + 1];
5547:   }
5548:   PetscCall(PetscCalloc1(2 * nrows, &nlcols));
5549:   PetscCall(PetscCalloc1(2 * nrows, &loffsets));
5550:   /* 'r' means root, and 'l' means leaf */
5551:   PetscCall(PetscSFBcastBegin(sf, MPIU_2INT, nrcols, nlcols, MPI_REPLACE));
5552:   PetscCall(PetscSFBcastBegin(sf, MPIU_2INT, roffsets, loffsets, MPI_REPLACE));
5553:   PetscCall(PetscSFBcastEnd(sf, MPIU_2INT, nrcols, nlcols, MPI_REPLACE));
5554:   PetscCall(PetscSFBcastEnd(sf, MPIU_2INT, roffsets, loffsets, MPI_REPLACE));
5555:   PetscCall(PetscSFDestroy(&sf));
5556:   PetscCall(PetscFree(roffsets));
5557:   PetscCall(PetscFree(nrcols));
5558:   dntotalcols = 0;
5559:   ontotalcols = 0;
5560:   ncol        = 0;
5561:   for (i = 0; i < nrows; i++) {
5562:     pnnz[i] = nlcols[i * 2 + 0] + nlcols[i * 2 + 1];
5563:     ncol    = PetscMax(pnnz[i], ncol);
5564:     /* diagonal */
5565:     dntotalcols += nlcols[i * 2 + 0];
5566:     /* off-diagonal */
5567:     ontotalcols += nlcols[i * 2 + 1];
5568:   }
5569:   /* We do not need to figure the right number of columns
5570:    * since all the calculations will be done by going through the raw data
5571:    * */
5572:   PetscCall(MatCreateSeqAIJ(PETSC_COMM_SELF, nrows, ncol, 0, pnnz, P_oth));
5573:   PetscCall(MatSetUp(*P_oth));
5574:   PetscCall(PetscFree(pnnz));
5575:   p_oth = (Mat_SeqAIJ *)(*P_oth)->data;
5576:   /* diagonal */
5577:   PetscCall(PetscCalloc1(dntotalcols, &iremote));
5578:   /* off-diagonal */
5579:   PetscCall(PetscCalloc1(ontotalcols, &oiremote));
5580:   /* diagonal */
5581:   PetscCall(PetscCalloc1(dntotalcols, &ilocal));
5582:   /* off-diagonal */
5583:   PetscCall(PetscCalloc1(ontotalcols, &oilocal));
5584:   dntotalcols = 0;
5585:   ontotalcols = 0;
5586:   ntotalcols  = 0;
5587:   for (i = 0; i < nrows; i++) {
5588:     owner = 0;
5589:     PetscCall(PetscLayoutFindOwnerIndex(P->rmap, lrowindices[i], &owner, NULL));
5590:     /* Set iremote for diag matrix */
5591:     for (j = 0; j < nlcols[i * 2 + 0]; j++) {
5592:       iremote[dntotalcols].index = loffsets[i * 2 + 0] + j;
5593:       iremote[dntotalcols].rank  = owner;
5594:       /* P_oth is seqAIJ so that ilocal need to point to the first part of memory */
5595:       ilocal[dntotalcols++] = ntotalcols++;
5596:     }
5597:     /* off-diagonal */
5598:     for (j = 0; j < nlcols[i * 2 + 1]; j++) {
5599:       oiremote[ontotalcols].index = loffsets[i * 2 + 1] + j;
5600:       oiremote[ontotalcols].rank  = owner;
5601:       oilocal[ontotalcols++]      = ntotalcols++;
5602:     }
5603:   }
5604:   PetscCall(ISRestoreIndices(rows, &lrowindices));
5605:   PetscCall(PetscFree(loffsets));
5606:   PetscCall(PetscFree(nlcols));
5607:   PetscCall(PetscSFCreate(comm, &sf));
5608:   /* P serves as roots and P_oth is leaves
5609:    * Diag matrix
5610:    * */
5611:   PetscCall(PetscSFSetGraph(sf, pd->i[plocalsize], dntotalcols, ilocal, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));
5612:   PetscCall(PetscSFSetFromOptions(sf));
5613:   PetscCall(PetscSFSetUp(sf));

5615:   PetscCall(PetscSFCreate(comm, &osf));
5616:   /* off-diagonal */
5617:   PetscCall(PetscSFSetGraph(osf, po->i[plocalsize], ontotalcols, oilocal, PETSC_OWN_POINTER, oiremote, PETSC_OWN_POINTER));
5618:   PetscCall(PetscSFSetFromOptions(osf));
5619:   PetscCall(PetscSFSetUp(osf));
5620:   PetscCall(MatSeqAIJGetArrayRead(p->A, &pd_a));
5621:   PetscCall(MatSeqAIJGetArrayRead(p->B, &po_a));
5622:   /* operate on the matrix internal data to save memory */
5623:   PetscCall(PetscSFBcastBegin(sf, MPIU_SCALAR, pd_a, p_oth->a, MPI_REPLACE));
5624:   PetscCall(PetscSFBcastBegin(osf, MPIU_SCALAR, po_a, p_oth->a, MPI_REPLACE));
5625:   PetscCall(MatGetOwnershipRangeColumn(P, &pcstart, NULL));
5626:   /* Convert to global indices for diag matrix */
5627:   for (i = 0; i < pd->i[plocalsize]; i++) pd->j[i] += pcstart;
5628:   PetscCall(PetscSFBcastBegin(sf, MPIU_INT, pd->j, p_oth->j, MPI_REPLACE));
5629:   /* We want P_oth store global indices */
5630:   PetscCall(ISLocalToGlobalMappingCreate(comm, 1, p->B->cmap->n, p->garray, PETSC_COPY_VALUES, &mapping));
5631:   /* Use memory scalable approach */
5632:   PetscCall(ISLocalToGlobalMappingSetType(mapping, ISLOCALTOGLOBALMAPPINGHASH));
5633:   PetscCall(ISLocalToGlobalMappingApply(mapping, po->i[plocalsize], po->j, po->j));
5634:   PetscCall(PetscSFBcastBegin(osf, MPIU_INT, po->j, p_oth->j, MPI_REPLACE));
5635:   PetscCall(PetscSFBcastEnd(sf, MPIU_INT, pd->j, p_oth->j, MPI_REPLACE));
5636:   /* Convert back to local indices */
5637:   for (i = 0; i < pd->i[plocalsize]; i++) pd->j[i] -= pcstart;
5638:   PetscCall(PetscSFBcastEnd(osf, MPIU_INT, po->j, p_oth->j, MPI_REPLACE));
5639:   nout = 0;
5640:   PetscCall(ISGlobalToLocalMappingApply(mapping, IS_GTOLM_DROP, po->i[plocalsize], po->j, &nout, po->j));
5641:   PetscCheck(nout == po->i[plocalsize], comm, PETSC_ERR_ARG_INCOMP, "n %" PetscInt_FMT " does not equal to nout %" PetscInt_FMT " ", po->i[plocalsize], nout);
5642:   PetscCall(ISLocalToGlobalMappingDestroy(&mapping));
5643:   /* Exchange values */
5644:   PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, pd_a, p_oth->a, MPI_REPLACE));
5645:   PetscCall(PetscSFBcastEnd(osf, MPIU_SCALAR, po_a, p_oth->a, MPI_REPLACE));
5646:   PetscCall(MatSeqAIJRestoreArrayRead(p->A, &pd_a));
5647:   PetscCall(MatSeqAIJRestoreArrayRead(p->B, &po_a));
5648:   /* Stop PETSc from shrinking memory */
5649:   for (i = 0; i < nrows; i++) p_oth->ilen[i] = p_oth->imax[i];
5650:   PetscCall(MatAssemblyBegin(*P_oth, MAT_FINAL_ASSEMBLY));
5651:   PetscCall(MatAssemblyEnd(*P_oth, MAT_FINAL_ASSEMBLY));
5652:   /* Attach PetscSF objects to P_oth so that we can reuse it later */
5653:   PetscCall(PetscObjectCompose((PetscObject)*P_oth, "diagsf", (PetscObject)sf));
5654:   PetscCall(PetscObjectCompose((PetscObject)*P_oth, "offdiagsf", (PetscObject)osf));
5655:   PetscCall(PetscSFDestroy(&sf));
5656:   PetscCall(PetscSFDestroy(&osf));
5657:   PetscFunctionReturn(PETSC_SUCCESS);
5658: }

5660: /*
5661:  * Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5662:  * This supports MPIAIJ and MAIJ
5663:  * */
5664: PetscErrorCode MatGetBrowsOfAcols_MPIXAIJ(Mat A, Mat P, PetscInt dof, MatReuse reuse, Mat *P_oth)
5665: {
5666:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data, *p = (Mat_MPIAIJ *)P->data;
5667:   Mat_SeqAIJ *p_oth;
5668:   IS          rows, map;
5669:   PetscHMapI  hamp;
5670:   PetscInt    i, htsize, *rowindices, off, *mapping, key, count;
5671:   MPI_Comm    comm;
5672:   PetscSF     sf, osf;
5673:   PetscBool   has;

5675:   PetscFunctionBegin;
5676:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
5677:   PetscCall(PetscLogEventBegin(MAT_GetBrowsOfAocols, A, P, 0, 0));
5678:   /* If it is the first time, create an index set of off-diag nonzero columns of A,
5679:    *  and then create a submatrix (that often is an overlapping matrix)
5680:    * */
5681:   if (reuse == MAT_INITIAL_MATRIX) {
5682:     /* Use a hash table to figure out unique keys */
5683:     PetscCall(PetscHMapICreateWithSize(a->B->cmap->n, &hamp));
5684:     PetscCall(PetscCalloc1(a->B->cmap->n, &mapping));
5685:     count = 0;
5686:     /* Assume that  a->g is sorted, otherwise the following does not make sense */
5687:     for (i = 0; i < a->B->cmap->n; i++) {
5688:       key = a->garray[i] / dof;
5689:       PetscCall(PetscHMapIHas(hamp, key, &has));
5690:       if (!has) {
5691:         mapping[i] = count;
5692:         PetscCall(PetscHMapISet(hamp, key, count++));
5693:       } else {
5694:         /* Current 'i' has the same value the previous step */
5695:         mapping[i] = count - 1;
5696:       }
5697:     }
5698:     PetscCall(ISCreateGeneral(comm, a->B->cmap->n, mapping, PETSC_OWN_POINTER, &map));
5699:     PetscCall(PetscHMapIGetSize(hamp, &htsize));
5700:     PetscCheck(htsize == count, comm, PETSC_ERR_ARG_INCOMP, " Size of hash map %" PetscInt_FMT " is inconsistent with count %" PetscInt_FMT, htsize, count);
5701:     PetscCall(PetscCalloc1(htsize, &rowindices));
5702:     off = 0;
5703:     PetscCall(PetscHMapIGetKeys(hamp, &off, rowindices));
5704:     PetscCall(PetscHMapIDestroy(&hamp));
5705:     PetscCall(PetscSortInt(htsize, rowindices));
5706:     PetscCall(ISCreateGeneral(comm, htsize, rowindices, PETSC_OWN_POINTER, &rows));
5707:     /* In case, the matrix was already created but users want to recreate the matrix */
5708:     PetscCall(MatDestroy(P_oth));
5709:     PetscCall(MatCreateSeqSubMatrixWithRows_Private(P, rows, P_oth));
5710:     PetscCall(PetscObjectCompose((PetscObject)*P_oth, "aoffdiagtopothmapping", (PetscObject)map));
5711:     PetscCall(ISDestroy(&map));
5712:     PetscCall(ISDestroy(&rows));
5713:   } else if (reuse == MAT_REUSE_MATRIX) {
5714:     /* If matrix was already created, we simply update values using SF objects
5715:      * that as attached to the matrix earlier.
5716:      */
5717:     const PetscScalar *pd_a, *po_a;

5719:     PetscCall(PetscObjectQuery((PetscObject)*P_oth, "diagsf", (PetscObject *)&sf));
5720:     PetscCall(PetscObjectQuery((PetscObject)*P_oth, "offdiagsf", (PetscObject *)&osf));
5721:     PetscCheck(sf && osf, comm, PETSC_ERR_ARG_NULL, "Matrix is not initialized yet");
5722:     p_oth = (Mat_SeqAIJ *)(*P_oth)->data;
5723:     /* Update values in place */
5724:     PetscCall(MatSeqAIJGetArrayRead(p->A, &pd_a));
5725:     PetscCall(MatSeqAIJGetArrayRead(p->B, &po_a));
5726:     PetscCall(PetscSFBcastBegin(sf, MPIU_SCALAR, pd_a, p_oth->a, MPI_REPLACE));
5727:     PetscCall(PetscSFBcastBegin(osf, MPIU_SCALAR, po_a, p_oth->a, MPI_REPLACE));
5728:     PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, pd_a, p_oth->a, MPI_REPLACE));
5729:     PetscCall(PetscSFBcastEnd(osf, MPIU_SCALAR, po_a, p_oth->a, MPI_REPLACE));
5730:     PetscCall(MatSeqAIJRestoreArrayRead(p->A, &pd_a));
5731:     PetscCall(MatSeqAIJRestoreArrayRead(p->B, &po_a));
5732:   } else SETERRQ(comm, PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown reuse type");
5733:   PetscCall(PetscLogEventEnd(MAT_GetBrowsOfAocols, A, P, 0, 0));
5734:   PetscFunctionReturn(PETSC_SUCCESS);
5735: }

5737: /*@C
5738:   MatGetBrowsOfAcols - Returns `IS` that contain rows of `B` that equal to nonzero columns of local `A`

5740:   Collective

5742:   Input Parameters:
5743: + A     - the first matrix in `MATMPIAIJ` format
5744: . B     - the second matrix in `MATMPIAIJ` format
5745: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

5747:   Output Parameters:
5748: + rowb  - On input index sets of rows of B to extract (or `NULL`), modified on output
5749: . colb  - On input index sets of columns of B to extract (or `NULL`), modified on output
5750: - B_seq - the sequential matrix generated

5752:   Level: developer

5754: .seealso: `Mat`, `MATMPIAIJ`, `IS`, `MatReuse`
5755: @*/
5756: PetscErrorCode MatGetBrowsOfAcols(Mat A, Mat B, MatReuse scall, IS *rowb, IS *colb, Mat *B_seq)
5757: {
5758:   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
5759:   PetscInt   *idx, i, start, ncols, nzA, nzB, *cmap, imark;
5760:   IS          isrowb, iscolb;
5761:   Mat        *bseq = NULL;

5763:   PetscFunctionBegin;
5764:   PetscCheck(A->cmap->rstart == B->rmap->rstart && A->cmap->rend == B->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")",
5765:              A->cmap->rstart, A->cmap->rend, B->rmap->rstart, B->rmap->rend);
5766:   PetscCall(PetscLogEventBegin(MAT_GetBrowsOfAcols, A, B, 0, 0));

5768:   if (scall == MAT_INITIAL_MATRIX) {
5769:     start = A->cmap->rstart;
5770:     cmap  = a->garray;
5771:     nzA   = a->A->cmap->n;
5772:     nzB   = a->B->cmap->n;
5773:     PetscCall(PetscMalloc1(nzA + nzB, &idx));
5774:     ncols = 0;
5775:     for (i = 0; i < nzB; i++) { /* row < local row index */
5776:       if (cmap[i] < start) idx[ncols++] = cmap[i];
5777:       else break;
5778:     }
5779:     imark = i;
5780:     for (i = 0; i < nzA; i++) idx[ncols++] = start + i;   /* local rows */
5781:     for (i = imark; i < nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5782:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, ncols, idx, PETSC_OWN_POINTER, &isrowb));
5783:     PetscCall(ISCreateStride(PETSC_COMM_SELF, B->cmap->N, 0, 1, &iscolb));
5784:   } else {
5785:     PetscCheck(rowb && colb, PETSC_COMM_SELF, PETSC_ERR_SUP, "IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5786:     isrowb = *rowb;
5787:     iscolb = *colb;
5788:     PetscCall(PetscMalloc1(1, &bseq));
5789:     bseq[0] = *B_seq;
5790:   }
5791:   PetscCall(MatCreateSubMatrices(B, 1, &isrowb, &iscolb, scall, &bseq));
5792:   *B_seq = bseq[0];
5793:   PetscCall(PetscFree(bseq));
5794:   if (!rowb) {
5795:     PetscCall(ISDestroy(&isrowb));
5796:   } else {
5797:     *rowb = isrowb;
5798:   }
5799:   if (!colb) {
5800:     PetscCall(ISDestroy(&iscolb));
5801:   } else {
5802:     *colb = iscolb;
5803:   }
5804:   PetscCall(PetscLogEventEnd(MAT_GetBrowsOfAcols, A, B, 0, 0));
5805:   PetscFunctionReturn(PETSC_SUCCESS);
5806: }

5808: /*
5809:     MatGetBrowsOfAoCols_MPIAIJ - Creates a `MATSEQAIJ` matrix by taking rows of B that equal to nonzero columns
5810:     of the OFF-DIAGONAL portion of local A

5812:     Collective

5814:    Input Parameters:
5815: +    A,B - the matrices in `MATMPIAIJ` format
5816: -    scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

5818:    Output Parameter:
5819: +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5820: .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5821: .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5822: -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N

5824:     Developer Note:
5825:     This directly accesses information inside the VecScatter associated with the matrix-vector product
5826:      for this matrix. This is not desirable..

5828:     Level: developer

5830: */

5832: PetscErrorCode MatGetBrowsOfAoCols_MPIAIJ(Mat A, Mat B, MatReuse scall, PetscInt **startsj_s, PetscInt **startsj_r, MatScalar **bufa_ptr, Mat *B_oth)
5833: {
5834:   Mat_MPIAIJ        *a = (Mat_MPIAIJ *)A->data;
5835:   VecScatter         ctx;
5836:   MPI_Comm           comm;
5837:   const PetscMPIInt *rprocs, *sprocs;
5838:   PetscMPIInt        nrecvs, nsends;
5839:   const PetscInt    *srow, *rstarts, *sstarts;
5840:   PetscInt          *rowlen, *bufj, *bufJ, ncols = 0, aBn = a->B->cmap->n, row, *b_othi, *b_othj, *rvalues = NULL, *svalues = NULL, *cols, sbs, rbs;
5841:   PetscInt           i, j, k = 0, l, ll, nrows, *rstartsj = NULL, *sstartsj, len;
5842:   PetscScalar       *b_otha, *bufa, *bufA, *vals = NULL;
5843:   MPI_Request       *reqs = NULL, *rwaits = NULL, *swaits = NULL;
5844:   PetscMPIInt        size, tag, rank, nreqs;

5846:   PetscFunctionBegin;
5847:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
5848:   PetscCallMPI(MPI_Comm_size(comm, &size));

5850:   PetscCheck(A->cmap->rstart == B->rmap->rstart && A->cmap->rend == B->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")",
5851:              A->cmap->rstart, A->cmap->rend, B->rmap->rstart, B->rmap->rend);
5852:   PetscCall(PetscLogEventBegin(MAT_GetBrowsOfAocols, A, B, 0, 0));
5853:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

5855:   if (size == 1) {
5856:     startsj_s = NULL;
5857:     bufa_ptr  = NULL;
5858:     *B_oth    = NULL;
5859:     PetscFunctionReturn(PETSC_SUCCESS);
5860:   }

5862:   ctx = a->Mvctx;
5863:   tag = ((PetscObject)ctx)->tag;

5865:   PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &srow, &sprocs, &sbs));
5866:   /* rprocs[] must be ordered so that indices received from them are ordered in rvalues[], which is key to algorithms used in this subroutine */
5867:   PetscCall(VecScatterGetRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL /*indices not needed*/, &rprocs, &rbs));
5868:   PetscCall(PetscMPIIntCast(nsends + nrecvs, &nreqs));
5869:   PetscCall(PetscMalloc1(nreqs, &reqs));
5870:   rwaits = reqs;
5871:   swaits = PetscSafePointerPlusOffset(reqs, nrecvs);

5873:   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5874:   if (scall == MAT_INITIAL_MATRIX) {
5875:     /* i-array */
5876:     /*  post receives */
5877:     if (nrecvs) PetscCall(PetscMalloc1(rbs * (rstarts[nrecvs] - rstarts[0]), &rvalues)); /* rstarts can be NULL when nrecvs=0 */
5878:     for (i = 0; i < nrecvs; i++) {
5879:       rowlen = rvalues + rstarts[i] * rbs;
5880:       nrows  = (rstarts[i + 1] - rstarts[i]) * rbs; /* num of indices to be received */
5881:       PetscCallMPI(MPIU_Irecv(rowlen, nrows, MPIU_INT, rprocs[i], tag, comm, rwaits + i));
5882:     }

5884:     /* pack the outgoing message */
5885:     PetscCall(PetscMalloc2(nsends + 1, &sstartsj, nrecvs + 1, &rstartsj));

5887:     sstartsj[0] = 0;
5888:     rstartsj[0] = 0;
5889:     len         = 0; /* total length of j or a array to be sent */
5890:     if (nsends) {
5891:       k = sstarts[0]; /* ATTENTION: sstarts[0] and rstarts[0] are not necessarily zero */
5892:       PetscCall(PetscMalloc1(sbs * (sstarts[nsends] - sstarts[0]), &svalues));
5893:     }
5894:     for (i = 0; i < nsends; i++) {
5895:       rowlen = svalues + (sstarts[i] - sstarts[0]) * sbs;
5896:       nrows  = sstarts[i + 1] - sstarts[i]; /* num of block rows */
5897:       for (j = 0; j < nrows; j++) {
5898:         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5899:         for (l = 0; l < sbs; l++) {
5900:           PetscCall(MatGetRow_MPIAIJ(B, row + l, &ncols, NULL, NULL)); /* rowlength */

5902:           rowlen[j * sbs + l] = ncols;

5904:           len += ncols;
5905:           PetscCall(MatRestoreRow_MPIAIJ(B, row + l, &ncols, NULL, NULL));
5906:         }
5907:         k++;
5908:       }
5909:       PetscCallMPI(MPIU_Isend(rowlen, nrows * sbs, MPIU_INT, sprocs[i], tag, comm, swaits + i));

5911:       sstartsj[i + 1] = len; /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5912:     }
5913:     /* recvs and sends of i-array are completed */
5914:     if (nreqs) PetscCallMPI(MPI_Waitall(nreqs, reqs, MPI_STATUSES_IGNORE));
5915:     PetscCall(PetscFree(svalues));

5917:     /* allocate buffers for sending j and a arrays */
5918:     PetscCall(PetscMalloc1(len + 1, &bufj));
5919:     PetscCall(PetscMalloc1(len + 1, &bufa));

5921:     /* create i-array of B_oth */
5922:     PetscCall(PetscMalloc1(aBn + 2, &b_othi));

5924:     b_othi[0] = 0;
5925:     len       = 0; /* total length of j or a array to be received */
5926:     k         = 0;
5927:     for (i = 0; i < nrecvs; i++) {
5928:       rowlen = rvalues + (rstarts[i] - rstarts[0]) * rbs;
5929:       nrows  = (rstarts[i + 1] - rstarts[i]) * rbs; /* num of rows to be received */
5930:       for (j = 0; j < nrows; j++) {
5931:         b_othi[k + 1] = b_othi[k] + rowlen[j];
5932:         PetscCall(PetscIntSumError(rowlen[j], len, &len));
5933:         k++;
5934:       }
5935:       rstartsj[i + 1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5936:     }
5937:     PetscCall(PetscFree(rvalues));

5939:     /* allocate space for j and a arrays of B_oth */
5940:     PetscCall(PetscMalloc1(b_othi[aBn] + 1, &b_othj));
5941:     PetscCall(PetscMalloc1(b_othi[aBn] + 1, &b_otha));

5943:     /* j-array */
5944:     /*  post receives of j-array */
5945:     for (i = 0; i < nrecvs; i++) {
5946:       nrows = rstartsj[i + 1] - rstartsj[i]; /* length of the msg received */
5947:       PetscCallMPI(MPIU_Irecv(b_othj + rstartsj[i], nrows, MPIU_INT, rprocs[i], tag, comm, rwaits + i));
5948:     }

5950:     /* pack the outgoing message j-array */
5951:     if (nsends) k = sstarts[0];
5952:     for (i = 0; i < nsends; i++) {
5953:       nrows = sstarts[i + 1] - sstarts[i]; /* num of block rows */
5954:       bufJ  = bufj + sstartsj[i];
5955:       for (j = 0; j < nrows; j++) {
5956:         row = srow[k++] + B->rmap->range[rank]; /* global row idx */
5957:         for (ll = 0; ll < sbs; ll++) {
5958:           PetscCall(MatGetRow_MPIAIJ(B, row + ll, &ncols, &cols, NULL));
5959:           for (l = 0; l < ncols; l++) *bufJ++ = cols[l];
5960:           PetscCall(MatRestoreRow_MPIAIJ(B, row + ll, &ncols, &cols, NULL));
5961:         }
5962:       }
5963:       PetscCallMPI(MPIU_Isend(bufj + sstartsj[i], sstartsj[i + 1] - sstartsj[i], MPIU_INT, sprocs[i], tag, comm, swaits + i));
5964:     }

5966:     /* recvs and sends of j-array are completed */
5967:     if (nreqs) PetscCallMPI(MPI_Waitall(nreqs, reqs, MPI_STATUSES_IGNORE));
5968:   } else if (scall == MAT_REUSE_MATRIX) {
5969:     sstartsj = *startsj_s;
5970:     rstartsj = *startsj_r;
5971:     bufa     = *bufa_ptr;
5972:     PetscCall(MatSeqAIJGetArrayWrite(*B_oth, &b_otha));
5973:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not possess an object container");

5975:   /* a-array */
5976:   /*  post receives of a-array */
5977:   for (i = 0; i < nrecvs; i++) {
5978:     nrows = rstartsj[i + 1] - rstartsj[i]; /* length of the msg received */
5979:     PetscCallMPI(MPIU_Irecv(b_otha + rstartsj[i], nrows, MPIU_SCALAR, rprocs[i], tag, comm, rwaits + i));
5980:   }

5982:   /* pack the outgoing message a-array */
5983:   if (nsends) k = sstarts[0];
5984:   for (i = 0; i < nsends; i++) {
5985:     nrows = sstarts[i + 1] - sstarts[i]; /* num of block rows */
5986:     bufA  = bufa + sstartsj[i];
5987:     for (j = 0; j < nrows; j++) {
5988:       row = srow[k++] + B->rmap->range[rank]; /* global row idx */
5989:       for (ll = 0; ll < sbs; ll++) {
5990:         PetscCall(MatGetRow_MPIAIJ(B, row + ll, &ncols, NULL, &vals));
5991:         for (l = 0; l < ncols; l++) *bufA++ = vals[l];
5992:         PetscCall(MatRestoreRow_MPIAIJ(B, row + ll, &ncols, NULL, &vals));
5993:       }
5994:     }
5995:     PetscCallMPI(MPIU_Isend(bufa + sstartsj[i], sstartsj[i + 1] - sstartsj[i], MPIU_SCALAR, sprocs[i], tag, comm, swaits + i));
5996:   }
5997:   /* recvs and sends of a-array are completed */
5998:   if (nreqs) PetscCallMPI(MPI_Waitall(nreqs, reqs, MPI_STATUSES_IGNORE));
5999:   PetscCall(PetscFree(reqs));

6001:   if (scall == MAT_INITIAL_MATRIX) {
6002:     Mat_SeqAIJ *b_oth;

6004:     /* put together the new matrix */
6005:     PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, aBn, B->cmap->N, b_othi, b_othj, b_otha, B_oth));

6007:     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
6008:     /* Since these are PETSc arrays, change flags to free them as necessary. */
6009:     b_oth          = (Mat_SeqAIJ *)(*B_oth)->data;
6010:     b_oth->free_a  = PETSC_TRUE;
6011:     b_oth->free_ij = PETSC_TRUE;
6012:     b_oth->nonew   = 0;

6014:     PetscCall(PetscFree(bufj));
6015:     if (!startsj_s || !bufa_ptr) {
6016:       PetscCall(PetscFree2(sstartsj, rstartsj));
6017:       PetscCall(PetscFree(bufa_ptr));
6018:     } else {
6019:       *startsj_s = sstartsj;
6020:       *startsj_r = rstartsj;
6021:       *bufa_ptr  = bufa;
6022:     }
6023:   } else if (scall == MAT_REUSE_MATRIX) {
6024:     PetscCall(MatSeqAIJRestoreArrayWrite(*B_oth, &b_otha));
6025:   }

6027:   PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE, &nsends, &sstarts, &srow, &sprocs, &sbs));
6028:   PetscCall(VecScatterRestoreRemoteOrdered_Private(ctx, PETSC_FALSE, &nrecvs, &rstarts, NULL, &rprocs, &rbs));
6029:   PetscCall(PetscLogEventEnd(MAT_GetBrowsOfAocols, A, B, 0, 0));
6030:   PetscFunctionReturn(PETSC_SUCCESS);
6031: }

6033: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat, MatType, MatReuse, Mat *);
6034: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat, MatType, MatReuse, Mat *);
6035: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJSELL(Mat, MatType, MatReuse, Mat *);
6036: #if defined(PETSC_HAVE_MKL_SPARSE)
6037: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJMKL(Mat, MatType, MatReuse, Mat *);
6038: #endif
6039: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIBAIJ(Mat, MatType, MatReuse, Mat *);
6040: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat, MatType, MatReuse, Mat *);
6041: #if defined(PETSC_HAVE_ELEMENTAL)
6042: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat, MatType, MatReuse, Mat *);
6043: #endif
6044: #if defined(PETSC_HAVE_SCALAPACK)
6045: PETSC_INTERN PetscErrorCode MatConvert_AIJ_ScaLAPACK(Mat, MatType, MatReuse, Mat *);
6046: #endif
6047: #if defined(PETSC_HAVE_HYPRE)
6048: PETSC_INTERN PetscErrorCode MatConvert_AIJ_HYPRE(Mat, MatType, MatReuse, Mat *);
6049: #endif
6050: #if defined(PETSC_HAVE_CUDA)
6051: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCUSPARSE(Mat, MatType, MatReuse, Mat *);
6052: #endif
6053: #if defined(PETSC_HAVE_HIP)
6054: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJHIPSPARSE(Mat, MatType, MatReuse, Mat *);
6055: #endif
6056: #if defined(PETSC_HAVE_KOKKOS_KERNELS)
6057: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJKokkos(Mat, MatType, MatReuse, Mat *);
6058: #endif
6059: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPISELL(Mat, MatType, MatReuse, Mat *);
6060: PETSC_INTERN PetscErrorCode MatConvert_XAIJ_IS(Mat, MatType, MatReuse, Mat *);
6061: PETSC_INTERN PetscErrorCode MatProductSetFromOptions_IS_XAIJ(Mat);

6063: /*
6064:     Computes (B'*A')' since computing B*A directly is untenable

6066:                n                       p                          p
6067:         [             ]       [             ]         [                 ]
6068:       m [      A      ]  *  n [       B     ]   =   m [         C       ]
6069:         [             ]       [             ]         [                 ]

6071: */
6072: static PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A, Mat B, Mat C)
6073: {
6074:   Mat At, Bt, Ct;

6076:   PetscFunctionBegin;
6077:   PetscCall(MatTranspose(A, MAT_INITIAL_MATRIX, &At));
6078:   PetscCall(MatTranspose(B, MAT_INITIAL_MATRIX, &Bt));
6079:   PetscCall(MatMatMult(Bt, At, MAT_INITIAL_MATRIX, PETSC_CURRENT, &Ct));
6080:   PetscCall(MatDestroy(&At));
6081:   PetscCall(MatDestroy(&Bt));
6082:   PetscCall(MatTransposeSetPrecursor(Ct, C));
6083:   PetscCall(MatTranspose(Ct, MAT_REUSE_MATRIX, &C));
6084:   PetscCall(MatDestroy(&Ct));
6085:   PetscFunctionReturn(PETSC_SUCCESS);
6086: }

6088: static PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A, Mat B, PetscReal fill, Mat C)
6089: {
6090:   PetscBool cisdense;

6092:   PetscFunctionBegin;
6093:   PetscCheck(A->cmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "A->cmap->n %" PetscInt_FMT " != B->rmap->n %" PetscInt_FMT, A->cmap->n, B->rmap->n);
6094:   PetscCall(MatSetSizes(C, A->rmap->n, B->cmap->n, A->rmap->N, B->cmap->N));
6095:   PetscCall(MatSetBlockSizesFromMats(C, A, B));
6096:   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &cisdense, MATMPIDENSE, MATMPIDENSECUDA, MATMPIDENSEHIP, ""));
6097:   if (!cisdense) PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
6098:   PetscCall(MatSetUp(C));

6100:   C->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
6101:   PetscFunctionReturn(PETSC_SUCCESS);
6102: }

6104: static PetscErrorCode MatProductSetFromOptions_MPIDense_MPIAIJ_AB(Mat C)
6105: {
6106:   Mat_Product *product = C->product;
6107:   Mat          A = product->A, B = product->B;

6109:   PetscFunctionBegin;
6110:   PetscCheck(A->cmap->rstart == B->rmap->rstart && A->cmap->rend == B->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")",
6111:              A->cmap->rstart, A->cmap->rend, B->rmap->rstart, B->rmap->rend);
6112:   C->ops->matmultsymbolic = MatMatMultSymbolic_MPIDense_MPIAIJ;
6113:   C->ops->productsymbolic = MatProductSymbolic_AB;
6114:   PetscFunctionReturn(PETSC_SUCCESS);
6115: }

6117: PETSC_INTERN PetscErrorCode MatProductSetFromOptions_MPIDense_MPIAIJ(Mat C)
6118: {
6119:   Mat_Product *product = C->product;

6121:   PetscFunctionBegin;
6122:   if (product->type == MATPRODUCT_AB) PetscCall(MatProductSetFromOptions_MPIDense_MPIAIJ_AB(C));
6123:   PetscFunctionReturn(PETSC_SUCCESS);
6124: }

6126: /*
6127:    Merge two sets of sorted nonzeros and return a CSR for the merged (sequential) matrix

6129:   Input Parameters:

6131:     j1,rowBegin1,rowEnd1,jmap1: describe the first set of nonzeros (Set1)
6132:     j2,rowBegin2,rowEnd2,jmap2: describe the second set of nonzeros (Set2)

6134:     mat: both sets' nonzeros are on m rows, where m is the number of local rows of the matrix mat

6136:     For Set1, j1[] contains column indices of the nonzeros.
6137:     For the k-th row (0<=k<m), [rowBegin1[k],rowEnd1[k]) index into j1[] and point to the begin/end nonzero in row k
6138:     respectively (note rowEnd1[k] is not necessarily equal to rwoBegin1[k+1]). Indices in this range of j1[] are sorted,
6139:     but might have repeats. jmap1[t+1] - jmap1[t] is the number of repeats for the t-th unique nonzero in Set1.

6141:     Similar for Set2.

6143:     This routine merges the two sets of nonzeros row by row and removes repeats.

6145:   Output Parameters: (memory is allocated by the caller)

6147:     i[],j[]: the CSR of the merged matrix, which has m rows.
6148:     imap1[]: the k-th unique nonzero in Set1 (k=0,1,...) corresponds to imap1[k]-th unique nonzero in the merged matrix.
6149:     imap2[]: similar to imap1[], but for Set2.
6150:     Note we order nonzeros row-by-row and from left to right.
6151: */
6152: static PetscErrorCode MatMergeEntries_Internal(Mat mat, const PetscInt j1[], const PetscInt j2[], const PetscCount rowBegin1[], const PetscCount rowEnd1[], const PetscCount rowBegin2[], const PetscCount rowEnd2[], const PetscCount jmap1[], const PetscCount jmap2[], PetscCount imap1[], PetscCount imap2[], PetscInt i[], PetscInt j[])
6153: {
6154:   PetscInt   r, m; /* Row index of mat */
6155:   PetscCount t, t1, t2, b1, e1, b2, e2;

6157:   PetscFunctionBegin;
6158:   PetscCall(MatGetLocalSize(mat, &m, NULL));
6159:   t1 = t2 = t = 0; /* Count unique nonzeros of in Set1, Set1 and the merged respectively */
6160:   i[0]        = 0;
6161:   for (r = 0; r < m; r++) { /* Do row by row merging */
6162:     b1 = rowBegin1[r];
6163:     e1 = rowEnd1[r];
6164:     b2 = rowBegin2[r];
6165:     e2 = rowEnd2[r];
6166:     while (b1 < e1 && b2 < e2) {
6167:       if (j1[b1] == j2[b2]) { /* Same column index and hence same nonzero */
6168:         j[t]      = j1[b1];
6169:         imap1[t1] = t;
6170:         imap2[t2] = t;
6171:         b1 += jmap1[t1 + 1] - jmap1[t1]; /* Jump to next unique local nonzero */
6172:         b2 += jmap2[t2 + 1] - jmap2[t2]; /* Jump to next unique remote nonzero */
6173:         t1++;
6174:         t2++;
6175:         t++;
6176:       } else if (j1[b1] < j2[b2]) {
6177:         j[t]      = j1[b1];
6178:         imap1[t1] = t;
6179:         b1 += jmap1[t1 + 1] - jmap1[t1];
6180:         t1++;
6181:         t++;
6182:       } else {
6183:         j[t]      = j2[b2];
6184:         imap2[t2] = t;
6185:         b2 += jmap2[t2 + 1] - jmap2[t2];
6186:         t2++;
6187:         t++;
6188:       }
6189:     }
6190:     /* Merge the remaining in either j1[] or j2[] */
6191:     while (b1 < e1) {
6192:       j[t]      = j1[b1];
6193:       imap1[t1] = t;
6194:       b1 += jmap1[t1 + 1] - jmap1[t1];
6195:       t1++;
6196:       t++;
6197:     }
6198:     while (b2 < e2) {
6199:       j[t]      = j2[b2];
6200:       imap2[t2] = t;
6201:       b2 += jmap2[t2 + 1] - jmap2[t2];
6202:       t2++;
6203:       t++;
6204:     }
6205:     PetscCall(PetscIntCast(t, i + r + 1));
6206:   }
6207:   PetscFunctionReturn(PETSC_SUCCESS);
6208: }

6210: /*
6211:   Split nonzeros in a block of local rows into two subsets: those in the diagonal block and those in the off-diagonal block

6213:   Input Parameters:
6214:     mat: an MPI matrix that provides row and column layout information for splitting. Let's say its number of local rows is m.
6215:     n,i[],j[],perm[]: there are n input entries, belonging to m rows. Row/col indices of the entries are stored in i[] and j[]
6216:       respectively, along with a permutation array perm[]. Length of the i[],j[],perm[] arrays is n.

6218:       i[] is already sorted, but within a row, j[] is not sorted and might have repeats.
6219:       i[] might contain negative indices at the beginning, which means the corresponding entries should be ignored in the splitting.

6221:   Output Parameters:
6222:     j[],perm[]: the routine needs to sort j[] within each row along with perm[].
6223:     rowBegin[],rowMid[],rowEnd[]: of length m, and the memory is preallocated and zeroed by the caller.
6224:       They contain indices pointing to j[]. For 0<=r<m, [rowBegin[r],rowMid[r]) point to begin/end entries of row r of the diagonal block,
6225:       and [rowMid[r],rowEnd[r]) point to begin/end entries of row r of the off-diagonal block.

6227:     Aperm[],Ajmap[],Atot,Annz: Arrays are allocated by this routine.
6228:       Atot: number of entries belonging to the diagonal block.
6229:       Annz: number of unique nonzeros belonging to the diagonal block.
6230:       Aperm[Atot] stores values from perm[] for entries belonging to the diagonal block. Length of Aperm[] is Atot, though it may also count
6231:         repeats (i.e., same 'i,j' pair).
6232:       Ajmap[Annz+1] stores the number of repeats of each unique entry belonging to the diagonal block. More precisely, Ajmap[t+1] - Ajmap[t]
6233:         is the number of repeats for the t-th unique entry in the diagonal block. Ajmap[0] is always 0.

6235:       Atot: number of entries belonging to the diagonal block
6236:       Annz: number of unique nonzeros belonging to the diagonal block.

6238:     Bperm[], Bjmap[], Btot, Bnnz are similar but for the off-diagonal block.

6240:     Aperm[],Bperm[],Ajmap[] and Bjmap[] are allocated separately by this routine with PetscMalloc1().
6241: */
6242: static PetscErrorCode MatSplitEntries_Internal(Mat mat, PetscCount n, const PetscInt i[], PetscInt j[], PetscCount perm[], PetscCount rowBegin[], PetscCount rowMid[], PetscCount rowEnd[], PetscCount *Atot_, PetscCount **Aperm_, PetscCount *Annz_, PetscCount **Ajmap_, PetscCount *Btot_, PetscCount **Bperm_, PetscCount *Bnnz_, PetscCount **Bjmap_)
6243: {
6244:   PetscInt    cstart, cend, rstart, rend, row, col;
6245:   PetscCount  Atot = 0, Btot = 0; /* Total number of nonzeros in the diagonal and off-diagonal blocks */
6246:   PetscCount  Annz = 0, Bnnz = 0; /* Number of unique nonzeros in the diagonal and off-diagonal blocks */
6247:   PetscCount  k, m, p, q, r, s, mid;
6248:   PetscCount *Aperm, *Bperm, *Ajmap, *Bjmap;

6250:   PetscFunctionBegin;
6251:   PetscCall(PetscLayoutGetRange(mat->rmap, &rstart, &rend));
6252:   PetscCall(PetscLayoutGetRange(mat->cmap, &cstart, &cend));
6253:   m = rend - rstart;

6255:   /* Skip negative rows */
6256:   for (k = 0; k < n; k++)
6257:     if (i[k] >= 0) break;

6259:   /* Process [k,n): sort and partition each local row into diag and offdiag portions,
6260:      fill rowBegin[], rowMid[], rowEnd[], and count Atot, Btot, Annz, Bnnz.
6261:   */
6262:   while (k < n) {
6263:     row = i[k];
6264:     /* Entries in [k,s) are in one row. Shift diagonal block col indices so that diag is ahead of offdiag after sorting the row */
6265:     for (s = k; s < n; s++)
6266:       if (i[s] != row) break;

6268:     /* Shift diag columns to range of [-PETSC_INT_MAX, -1] */
6269:     for (p = k; p < s; p++) {
6270:       if (j[p] >= cstart && j[p] < cend) j[p] -= PETSC_INT_MAX;
6271:       else PetscAssert((j[p] >= 0) && (j[p] <= mat->cmap->N), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column index %" PetscInt_FMT " is out of range", j[p]);
6272:     }
6273:     PetscCall(PetscSortIntWithCountArray(s - k, j + k, perm + k));
6274:     PetscCall(PetscSortedIntUpperBound(j, k, s, -1, &mid)); /* Separate [k,s) into [k,mid) for diag and [mid,s) for offdiag */
6275:     rowBegin[row - rstart] = k;
6276:     rowMid[row - rstart]   = mid;
6277:     rowEnd[row - rstart]   = s;

6279:     /* Count nonzeros of this diag/offdiag row, which might have repeats */
6280:     Atot += mid - k;
6281:     Btot += s - mid;

6283:     /* Count unique nonzeros of this diag row */
6284:     for (p = k; p < mid;) {
6285:       col = j[p];
6286:       do {
6287:         j[p] += PETSC_INT_MAX; /* Revert the modified diagonal indices */
6288:         p++;
6289:       } while (p < mid && j[p] == col);
6290:       Annz++;
6291:     }

6293:     /* Count unique nonzeros of this offdiag row */
6294:     for (p = mid; p < s;) {
6295:       col = j[p];
6296:       do {
6297:         p++;
6298:       } while (p < s && j[p] == col);
6299:       Bnnz++;
6300:     }
6301:     k = s;
6302:   }

6304:   /* Allocation according to Atot, Btot, Annz, Bnnz */
6305:   PetscCall(PetscMalloc1(Atot, &Aperm));
6306:   PetscCall(PetscMalloc1(Btot, &Bperm));
6307:   PetscCall(PetscMalloc1(Annz + 1, &Ajmap));
6308:   PetscCall(PetscMalloc1(Bnnz + 1, &Bjmap));

6310:   /* Re-scan indices and copy diag/offdiag permutation indices to Aperm, Bperm and also fill Ajmap and Bjmap */
6311:   Ajmap[0] = Bjmap[0] = Atot = Btot = Annz = Bnnz = 0;
6312:   for (r = 0; r < m; r++) {
6313:     k   = rowBegin[r];
6314:     mid = rowMid[r];
6315:     s   = rowEnd[r];
6316:     PetscCall(PetscArraycpy(PetscSafePointerPlusOffset(Aperm, Atot), PetscSafePointerPlusOffset(perm, k), mid - k));
6317:     PetscCall(PetscArraycpy(PetscSafePointerPlusOffset(Bperm, Btot), PetscSafePointerPlusOffset(perm, mid), s - mid));
6318:     Atot += mid - k;
6319:     Btot += s - mid;

6321:     /* Scan column indices in this row and find out how many repeats each unique nonzero has */
6322:     for (p = k; p < mid;) {
6323:       col = j[p];
6324:       q   = p;
6325:       do {
6326:         p++;
6327:       } while (p < mid && j[p] == col);
6328:       Ajmap[Annz + 1] = Ajmap[Annz] + (p - q);
6329:       Annz++;
6330:     }

6332:     for (p = mid; p < s;) {
6333:       col = j[p];
6334:       q   = p;
6335:       do {
6336:         p++;
6337:       } while (p < s && j[p] == col);
6338:       Bjmap[Bnnz + 1] = Bjmap[Bnnz] + (p - q);
6339:       Bnnz++;
6340:     }
6341:   }
6342:   /* Output */
6343:   *Aperm_ = Aperm;
6344:   *Annz_  = Annz;
6345:   *Atot_  = Atot;
6346:   *Ajmap_ = Ajmap;
6347:   *Bperm_ = Bperm;
6348:   *Bnnz_  = Bnnz;
6349:   *Btot_  = Btot;
6350:   *Bjmap_ = Bjmap;
6351:   PetscFunctionReturn(PETSC_SUCCESS);
6352: }

6354: /*
6355:   Expand the jmap[] array to make a new one in view of nonzeros in the merged matrix

6357:   Input Parameters:
6358:     nnz1: number of unique nonzeros in a set that was used to produce imap[], jmap[]
6359:     nnz:  number of unique nonzeros in the merged matrix
6360:     imap[nnz1]: i-th nonzero in the set is the imap[i]-th nonzero in the merged matrix
6361:     jmap[nnz1+1]: i-th nonzero in the set has jmap[i+1] - jmap[i] repeats in the set

6363:   Output Parameter: (memory is allocated by the caller)
6364:     jmap_new[nnz+1]: i-th nonzero in the merged matrix has jmap_new[i+1] - jmap_new[i] repeats in the set

6366:   Example:
6367:     nnz1 = 4
6368:     nnz  = 6
6369:     imap = [1,3,4,5]
6370:     jmap = [0,3,5,6,7]
6371:    then,
6372:     jmap_new = [0,0,3,3,5,6,7]
6373: */
6374: static PetscErrorCode ExpandJmap_Internal(PetscCount nnz1, PetscCount nnz, const PetscCount imap[], const PetscCount jmap[], PetscCount jmap_new[])
6375: {
6376:   PetscCount k, p;

6378:   PetscFunctionBegin;
6379:   jmap_new[0] = 0;
6380:   p           = nnz;                /* p loops over jmap_new[] backwards */
6381:   for (k = nnz1 - 1; k >= 0; k--) { /* k loops over imap[] */
6382:     for (; p > imap[k]; p--) jmap_new[p] = jmap[k + 1];
6383:   }
6384:   for (; p >= 0; p--) jmap_new[p] = jmap[0];
6385:   PetscFunctionReturn(PETSC_SUCCESS);
6386: }

6388: static PetscErrorCode MatCOOStructDestroy_MPIAIJ(void **data)
6389: {
6390:   MatCOOStruct_MPIAIJ *coo = (MatCOOStruct_MPIAIJ *)*data;

6392:   PetscFunctionBegin;
6393:   PetscCall(PetscSFDestroy(&coo->sf));
6394:   PetscCall(PetscFree(coo->Aperm1));
6395:   PetscCall(PetscFree(coo->Bperm1));
6396:   PetscCall(PetscFree(coo->Ajmap1));
6397:   PetscCall(PetscFree(coo->Bjmap1));
6398:   PetscCall(PetscFree(coo->Aimap2));
6399:   PetscCall(PetscFree(coo->Bimap2));
6400:   PetscCall(PetscFree(coo->Aperm2));
6401:   PetscCall(PetscFree(coo->Bperm2));
6402:   PetscCall(PetscFree(coo->Ajmap2));
6403:   PetscCall(PetscFree(coo->Bjmap2));
6404:   PetscCall(PetscFree(coo->Cperm1));
6405:   PetscCall(PetscFree2(coo->sendbuf, coo->recvbuf));
6406:   PetscCall(PetscFree(coo));
6407:   PetscFunctionReturn(PETSC_SUCCESS);
6408: }

6410: PetscErrorCode MatSetPreallocationCOO_MPIAIJ(Mat mat, PetscCount coo_n, PetscInt coo_i[], PetscInt coo_j[])
6411: {
6412:   MPI_Comm             comm;
6413:   PetscMPIInt          rank, size;
6414:   PetscInt             m, n, M, N, rstart, rend, cstart, cend; /* Sizes, indices of row/col, therefore with type PetscInt */
6415:   PetscCount           k, p, q, rem;                           /* Loop variables over coo arrays */
6416:   Mat_MPIAIJ          *mpiaij = (Mat_MPIAIJ *)mat->data;
6417:   PetscContainer       container;
6418:   MatCOOStruct_MPIAIJ *coo;

6420:   PetscFunctionBegin;
6421:   PetscCall(PetscFree(mpiaij->garray));
6422:   PetscCall(VecDestroy(&mpiaij->lvec));
6423: #if defined(PETSC_USE_CTABLE)
6424:   PetscCall(PetscHMapIDestroy(&mpiaij->colmap));
6425: #else
6426:   PetscCall(PetscFree(mpiaij->colmap));
6427: #endif
6428:   PetscCall(VecScatterDestroy(&mpiaij->Mvctx));
6429:   mat->assembled     = PETSC_FALSE;
6430:   mat->was_assembled = PETSC_FALSE;

6432:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
6433:   PetscCallMPI(MPI_Comm_size(comm, &size));
6434:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
6435:   PetscCall(PetscLayoutSetUp(mat->rmap));
6436:   PetscCall(PetscLayoutSetUp(mat->cmap));
6437:   PetscCall(PetscLayoutGetRange(mat->rmap, &rstart, &rend));
6438:   PetscCall(PetscLayoutGetRange(mat->cmap, &cstart, &cend));
6439:   PetscCall(MatGetLocalSize(mat, &m, &n));
6440:   PetscCall(MatGetSize(mat, &M, &N));

6442:   /* Sort (i,j) by row along with a permutation array, so that the to-be-ignored */
6443:   /* entries come first, then local rows, then remote rows.                     */
6444:   PetscCount n1 = coo_n, *perm1;
6445:   PetscInt  *i1 = coo_i, *j1 = coo_j;

6447:   PetscCall(PetscMalloc1(n1, &perm1));
6448:   for (k = 0; k < n1; k++) perm1[k] = k;

6450:   /* Manipulate indices so that entries with negative row or col indices will have smallest
6451:      row indices, local entries will have greater but negative row indices, and remote entries
6452:      will have positive row indices.
6453:   */
6454:   for (k = 0; k < n1; k++) {
6455:     if (i1[k] < 0 || j1[k] < 0) i1[k] = PETSC_INT_MIN;                /* e.g., -2^31, minimal to move them ahead */
6456:     else if (i1[k] >= rstart && i1[k] < rend) i1[k] -= PETSC_INT_MAX; /* e.g., minus 2^31-1 to shift local rows to range of [-PETSC_INT_MAX, -1] */
6457:     else {
6458:       PetscCheck(!mat->nooffprocentries, PETSC_COMM_SELF, PETSC_ERR_USER_INPUT, "MAT_NO_OFF_PROC_ENTRIES is set but insert to remote rows");
6459:       if (mpiaij->donotstash) i1[k] = PETSC_INT_MIN; /* Ignore offproc entries as if they had negative indices */
6460:     }
6461:   }

6463:   /* Sort by row; after that, [0,k) have ignored entries, [k,rem) have local rows and [rem,n1) have remote rows */
6464:   PetscCall(PetscSortIntWithIntCountArrayPair(n1, i1, j1, perm1));

6466:   /* Advance k to the first entry we need to take care of */
6467:   for (k = 0; k < n1; k++)
6468:     if (i1[k] > PETSC_INT_MIN) break;
6469:   PetscCount i1start = k;

6471:   PetscCall(PetscSortedIntUpperBound(i1, k, n1, rend - 1 - PETSC_INT_MAX, &rem)); /* rem is upper bound of the last local row */
6472:   for (; k < rem; k++) i1[k] += PETSC_INT_MAX;                                    /* Revert row indices of local rows*/

6474:   /*           Send remote rows to their owner                                  */
6475:   /* Find which rows should be sent to which remote ranks*/
6476:   PetscInt        nsend = 0; /* Number of MPI ranks to send data to */
6477:   PetscMPIInt    *sendto;    /* [nsend], storing remote ranks */
6478:   PetscInt       *nentries;  /* [nsend], storing number of entries sent to remote ranks; Assume PetscInt is big enough for this count, and error if not */
6479:   const PetscInt *ranges;
6480:   PetscInt        maxNsend = size >= 128 ? 128 : size; /* Assume max 128 neighbors; realloc when needed */

6482:   PetscCall(PetscLayoutGetRanges(mat->rmap, &ranges));
6483:   PetscCall(PetscMalloc2(maxNsend, &sendto, maxNsend, &nentries));
6484:   for (k = rem; k < n1;) {
6485:     PetscMPIInt owner;
6486:     PetscInt    firstRow, lastRow;

6488:     /* Locate a row range */
6489:     firstRow = i1[k]; /* first row of this owner */
6490:     PetscCall(PetscLayoutFindOwner(mat->rmap, firstRow, &owner));
6491:     lastRow = ranges[owner + 1] - 1; /* last row of this owner */

6493:     /* Find the first index 'p' in [k,n) with i[p] belonging to next owner */
6494:     PetscCall(PetscSortedIntUpperBound(i1, k, n1, lastRow, &p));

6496:     /* All entries in [k,p) belong to this remote owner */
6497:     if (nsend >= maxNsend) { /* Double the remote ranks arrays if not long enough */
6498:       PetscMPIInt *sendto2;
6499:       PetscInt    *nentries2;
6500:       PetscInt     maxNsend2 = (maxNsend <= size / 2) ? maxNsend * 2 : size;

6502:       PetscCall(PetscMalloc2(maxNsend2, &sendto2, maxNsend2, &nentries2));
6503:       PetscCall(PetscArraycpy(sendto2, sendto, maxNsend));
6504:       PetscCall(PetscArraycpy(nentries2, nentries2, maxNsend + 1));
6505:       PetscCall(PetscFree2(sendto, nentries2));
6506:       sendto   = sendto2;
6507:       nentries = nentries2;
6508:       maxNsend = maxNsend2;
6509:     }
6510:     sendto[nsend] = owner;
6511:     PetscCall(PetscIntCast(p - k, &nentries[nsend]));
6512:     nsend++;
6513:     k = p;
6514:   }

6516:   /* Build 1st SF to know offsets on remote to send data */
6517:   PetscSF      sf1;
6518:   PetscInt     nroots = 1, nroots2 = 0;
6519:   PetscInt     nleaves = nsend, nleaves2 = 0;
6520:   PetscInt    *offsets;
6521:   PetscSFNode *iremote;

6523:   PetscCall(PetscSFCreate(comm, &sf1));
6524:   PetscCall(PetscMalloc1(nsend, &iremote));
6525:   PetscCall(PetscMalloc1(nsend, &offsets));
6526:   for (k = 0; k < nsend; k++) {
6527:     iremote[k].rank  = sendto[k];
6528:     iremote[k].index = 0;
6529:     nleaves2 += nentries[k];
6530:     PetscCheck(nleaves2 >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of SF leaves is too large for PetscInt");
6531:   }
6532:   PetscCall(PetscSFSetGraph(sf1, nroots, nleaves, NULL, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));
6533:   PetscCall(PetscSFFetchAndOpWithMemTypeBegin(sf1, MPIU_INT, PETSC_MEMTYPE_HOST, &nroots2 /*rootdata*/, PETSC_MEMTYPE_HOST, nentries /*leafdata*/, PETSC_MEMTYPE_HOST, offsets /*leafupdate*/, MPI_SUM));
6534:   PetscCall(PetscSFFetchAndOpEnd(sf1, MPIU_INT, &nroots2, nentries, offsets, MPI_SUM)); /* Would nroots2 overflow, we check offsets[] below */
6535:   PetscCall(PetscSFDestroy(&sf1));
6536:   PetscAssert(nleaves2 == n1 - rem, PETSC_COMM_SELF, PETSC_ERR_PLIB, "nleaves2 %" PetscInt_FMT " != number of remote entries %" PetscCount_FMT, nleaves2, n1 - rem);

6538:   /* Build 2nd SF to send remote COOs to their owner */
6539:   PetscSF sf2;
6540:   nroots  = nroots2;
6541:   nleaves = nleaves2;
6542:   PetscCall(PetscSFCreate(comm, &sf2));
6543:   PetscCall(PetscSFSetFromOptions(sf2));
6544:   PetscCall(PetscMalloc1(nleaves, &iremote));
6545:   p = 0;
6546:   for (k = 0; k < nsend; k++) {
6547:     PetscCheck(offsets[k] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of SF roots is too large for PetscInt");
6548:     for (q = 0; q < nentries[k]; q++, p++) {
6549:       iremote[p].rank = sendto[k];
6550:       PetscCall(PetscIntCast(offsets[k] + q, &iremote[p].index));
6551:     }
6552:   }
6553:   PetscCall(PetscSFSetGraph(sf2, nroots, nleaves, NULL, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));

6555:   /* Send the remote COOs to their owner */
6556:   PetscInt    n2 = nroots, *i2, *j2; /* Buffers for received COOs from other ranks, along with a permutation array */
6557:   PetscCount *perm2;                 /* Though PetscInt is enough for remote entries, we use PetscCount here as we want to reuse MatSplitEntries_Internal() */
6558:   PetscCall(PetscMalloc3(n2, &i2, n2, &j2, n2, &perm2));
6559:   PetscAssert(rem == 0 || i1 != NULL, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Cannot add nonzero offset to null");
6560:   PetscAssert(rem == 0 || j1 != NULL, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Cannot add nonzero offset to null");
6561:   PetscInt *i1prem = PetscSafePointerPlusOffset(i1, rem);
6562:   PetscInt *j1prem = PetscSafePointerPlusOffset(j1, rem);
6563:   PetscCall(PetscSFReduceWithMemTypeBegin(sf2, MPIU_INT, PETSC_MEMTYPE_HOST, i1prem, PETSC_MEMTYPE_HOST, i2, MPI_REPLACE));
6564:   PetscCall(PetscSFReduceEnd(sf2, MPIU_INT, i1prem, i2, MPI_REPLACE));
6565:   PetscCall(PetscSFReduceWithMemTypeBegin(sf2, MPIU_INT, PETSC_MEMTYPE_HOST, j1prem, PETSC_MEMTYPE_HOST, j2, MPI_REPLACE));
6566:   PetscCall(PetscSFReduceEnd(sf2, MPIU_INT, j1prem, j2, MPI_REPLACE));

6568:   PetscCall(PetscFree(offsets));
6569:   PetscCall(PetscFree2(sendto, nentries));

6571:   /* Sort received COOs by row along with the permutation array     */
6572:   for (k = 0; k < n2; k++) perm2[k] = k;
6573:   PetscCall(PetscSortIntWithIntCountArrayPair(n2, i2, j2, perm2));

6575:   /* sf2 only sends contiguous leafdata to contiguous rootdata. We record the permutation which will be used to fill leafdata */
6576:   PetscCount *Cperm1;
6577:   PetscAssert(rem == 0 || perm1 != NULL, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Cannot add nonzero offset to null");
6578:   PetscCount *perm1prem = PetscSafePointerPlusOffset(perm1, rem);
6579:   PetscCall(PetscMalloc1(nleaves, &Cperm1));
6580:   PetscCall(PetscArraycpy(Cperm1, perm1prem, nleaves));

6582:   /* Support for HYPRE matrices, kind of a hack.
6583:      Swap min column with diagonal so that diagonal values will go first */
6584:   PetscBool hypre;
6585:   PetscCall(PetscStrcmp("_internal_COO_mat_for_hypre", ((PetscObject)mat)->name, &hypre));
6586:   if (hypre) {
6587:     PetscInt *minj;
6588:     PetscBT   hasdiag;

6590:     PetscCall(PetscBTCreate(m, &hasdiag));
6591:     PetscCall(PetscMalloc1(m, &minj));
6592:     for (k = 0; k < m; k++) minj[k] = PETSC_INT_MAX;
6593:     for (k = i1start; k < rem; k++) {
6594:       if (j1[k] < cstart || j1[k] >= cend) continue;
6595:       const PetscInt rindex = i1[k] - rstart;
6596:       if ((j1[k] - cstart) == rindex) PetscCall(PetscBTSet(hasdiag, rindex));
6597:       minj[rindex] = PetscMin(minj[rindex], j1[k]);
6598:     }
6599:     for (k = 0; k < n2; k++) {
6600:       if (j2[k] < cstart || j2[k] >= cend) continue;
6601:       const PetscInt rindex = i2[k] - rstart;
6602:       if ((j2[k] - cstart) == rindex) PetscCall(PetscBTSet(hasdiag, rindex));
6603:       minj[rindex] = PetscMin(minj[rindex], j2[k]);
6604:     }
6605:     for (k = i1start; k < rem; k++) {
6606:       const PetscInt rindex = i1[k] - rstart;
6607:       if (j1[k] < cstart || j1[k] >= cend || !PetscBTLookup(hasdiag, rindex)) continue;
6608:       if (j1[k] == minj[rindex]) j1[k] = i1[k] + (cstart - rstart);
6609:       else if ((j1[k] - cstart) == rindex) j1[k] = minj[rindex];
6610:     }
6611:     for (k = 0; k < n2; k++) {
6612:       const PetscInt rindex = i2[k] - rstart;
6613:       if (j2[k] < cstart || j2[k] >= cend || !PetscBTLookup(hasdiag, rindex)) continue;
6614:       if (j2[k] == minj[rindex]) j2[k] = i2[k] + (cstart - rstart);
6615:       else if ((j2[k] - cstart) == rindex) j2[k] = minj[rindex];
6616:     }
6617:     PetscCall(PetscBTDestroy(&hasdiag));
6618:     PetscCall(PetscFree(minj));
6619:   }

6621:   /* Split local COOs and received COOs into diag/offdiag portions */
6622:   PetscCount *rowBegin1, *rowMid1, *rowEnd1;
6623:   PetscCount *Ajmap1, *Aperm1, *Bjmap1, *Bperm1;
6624:   PetscCount  Annz1, Bnnz1, Atot1, Btot1;
6625:   PetscCount *rowBegin2, *rowMid2, *rowEnd2;
6626:   PetscCount *Ajmap2, *Aperm2, *Bjmap2, *Bperm2;
6627:   PetscCount  Annz2, Bnnz2, Atot2, Btot2;

6629:   PetscCall(PetscCalloc3(m, &rowBegin1, m, &rowMid1, m, &rowEnd1));
6630:   PetscCall(PetscCalloc3(m, &rowBegin2, m, &rowMid2, m, &rowEnd2));
6631:   PetscCall(MatSplitEntries_Internal(mat, rem, i1, j1, perm1, rowBegin1, rowMid1, rowEnd1, &Atot1, &Aperm1, &Annz1, &Ajmap1, &Btot1, &Bperm1, &Bnnz1, &Bjmap1));
6632:   PetscCall(MatSplitEntries_Internal(mat, n2, i2, j2, perm2, rowBegin2, rowMid2, rowEnd2, &Atot2, &Aperm2, &Annz2, &Ajmap2, &Btot2, &Bperm2, &Bnnz2, &Bjmap2));

6634:   /* Merge local COOs with received COOs: diag with diag, offdiag with offdiag */
6635:   PetscInt *Ai, *Bi;
6636:   PetscInt *Aj, *Bj;

6638:   PetscCall(PetscMalloc1(m + 1, &Ai));
6639:   PetscCall(PetscMalloc1(m + 1, &Bi));
6640:   PetscCall(PetscMalloc1(Annz1 + Annz2, &Aj)); /* Since local and remote entries might have dups, we might allocate excess memory */
6641:   PetscCall(PetscMalloc1(Bnnz1 + Bnnz2, &Bj));

6643:   PetscCount *Aimap1, *Bimap1, *Aimap2, *Bimap2;
6644:   PetscCall(PetscMalloc1(Annz1, &Aimap1));
6645:   PetscCall(PetscMalloc1(Bnnz1, &Bimap1));
6646:   PetscCall(PetscMalloc1(Annz2, &Aimap2));
6647:   PetscCall(PetscMalloc1(Bnnz2, &Bimap2));

6649:   PetscCall(MatMergeEntries_Internal(mat, j1, j2, rowBegin1, rowMid1, rowBegin2, rowMid2, Ajmap1, Ajmap2, Aimap1, Aimap2, Ai, Aj));
6650:   PetscCall(MatMergeEntries_Internal(mat, j1, j2, rowMid1, rowEnd1, rowMid2, rowEnd2, Bjmap1, Bjmap2, Bimap1, Bimap2, Bi, Bj));

6652:   /* Expand Ajmap1/Bjmap1 to make them based off nonzeros in A/B, since we     */
6653:   /* expect nonzeros in A/B most likely have local contributing entries        */
6654:   PetscInt    Annz = Ai[m];
6655:   PetscInt    Bnnz = Bi[m];
6656:   PetscCount *Ajmap1_new, *Bjmap1_new;

6658:   PetscCall(PetscMalloc1(Annz + 1, &Ajmap1_new));
6659:   PetscCall(PetscMalloc1(Bnnz + 1, &Bjmap1_new));

6661:   PetscCall(ExpandJmap_Internal(Annz1, Annz, Aimap1, Ajmap1, Ajmap1_new));
6662:   PetscCall(ExpandJmap_Internal(Bnnz1, Bnnz, Bimap1, Bjmap1, Bjmap1_new));

6664:   PetscCall(PetscFree(Aimap1));
6665:   PetscCall(PetscFree(Ajmap1));
6666:   PetscCall(PetscFree(Bimap1));
6667:   PetscCall(PetscFree(Bjmap1));
6668:   PetscCall(PetscFree3(rowBegin1, rowMid1, rowEnd1));
6669:   PetscCall(PetscFree3(rowBegin2, rowMid2, rowEnd2));
6670:   PetscCall(PetscFree(perm1));
6671:   PetscCall(PetscFree3(i2, j2, perm2));

6673:   Ajmap1 = Ajmap1_new;
6674:   Bjmap1 = Bjmap1_new;

6676:   /* Reallocate Aj, Bj once we know actual numbers of unique nonzeros in A and B */
6677:   if (Annz < Annz1 + Annz2) {
6678:     PetscInt *Aj_new;
6679:     PetscCall(PetscMalloc1(Annz, &Aj_new));
6680:     PetscCall(PetscArraycpy(Aj_new, Aj, Annz));
6681:     PetscCall(PetscFree(Aj));
6682:     Aj = Aj_new;
6683:   }

6685:   if (Bnnz < Bnnz1 + Bnnz2) {
6686:     PetscInt *Bj_new;
6687:     PetscCall(PetscMalloc1(Bnnz, &Bj_new));
6688:     PetscCall(PetscArraycpy(Bj_new, Bj, Bnnz));
6689:     PetscCall(PetscFree(Bj));
6690:     Bj = Bj_new;
6691:   }

6693:   /* Create new submatrices for on-process and off-process coupling                  */
6694:   PetscScalar     *Aa, *Ba;
6695:   MatType          rtype;
6696:   Mat_SeqAIJ      *a, *b;
6697:   PetscObjectState state;
6698:   PetscCall(PetscCalloc1(Annz, &Aa)); /* Zero matrix on device */
6699:   PetscCall(PetscCalloc1(Bnnz, &Ba));
6700:   /* make Aj[] local, i.e, based off the start column of the diagonal portion */
6701:   if (cstart) {
6702:     for (k = 0; k < Annz; k++) Aj[k] -= cstart;
6703:   }

6705:   PetscCall(MatGetRootType_Private(mat, &rtype));

6707:   MatSeqXAIJGetOptions_Private(mpiaij->A);
6708:   PetscCall(MatDestroy(&mpiaij->A));
6709:   PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, m, n, Ai, Aj, Aa, &mpiaij->A));
6710:   PetscCall(MatSetBlockSizesFromMats(mpiaij->A, mat, mat));
6711:   MatSeqXAIJRestoreOptions_Private(mpiaij->A);

6713:   MatSeqXAIJGetOptions_Private(mpiaij->B);
6714:   PetscCall(MatDestroy(&mpiaij->B));
6715:   PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, m, mat->cmap->N, Bi, Bj, Ba, &mpiaij->B));
6716:   PetscCall(MatSetBlockSizesFromMats(mpiaij->B, mat, mat));
6717:   MatSeqXAIJRestoreOptions_Private(mpiaij->B);

6719:   PetscCall(MatSetUpMultiply_MPIAIJ(mat));
6720:   mat->was_assembled = PETSC_TRUE; // was_assembled in effect means the Mvctx is built; doing so avoids redundant MatSetUpMultiply_MPIAIJ
6721:   state              = mpiaij->A->nonzerostate + mpiaij->B->nonzerostate;
6722:   PetscCallMPI(MPIU_Allreduce(&state, &mat->nonzerostate, 1, MPIU_INT64, MPI_SUM, PetscObjectComm((PetscObject)mat)));

6724:   a          = (Mat_SeqAIJ *)mpiaij->A->data;
6725:   b          = (Mat_SeqAIJ *)mpiaij->B->data;
6726:   a->free_a  = PETSC_TRUE;
6727:   a->free_ij = PETSC_TRUE;
6728:   b->free_a  = PETSC_TRUE;
6729:   b->free_ij = PETSC_TRUE;
6730:   a->maxnz   = a->nz;
6731:   b->maxnz   = b->nz;

6733:   /* conversion must happen AFTER multiply setup */
6734:   PetscCall(MatConvert(mpiaij->A, rtype, MAT_INPLACE_MATRIX, &mpiaij->A));
6735:   PetscCall(MatConvert(mpiaij->B, rtype, MAT_INPLACE_MATRIX, &mpiaij->B));
6736:   PetscCall(VecDestroy(&mpiaij->lvec));
6737:   PetscCall(MatCreateVecs(mpiaij->B, &mpiaij->lvec, NULL));

6739:   // Put the COO struct in a container and then attach that to the matrix
6740:   PetscCall(PetscMalloc1(1, &coo));
6741:   coo->n       = coo_n;
6742:   coo->sf      = sf2;
6743:   coo->sendlen = nleaves;
6744:   coo->recvlen = nroots;
6745:   coo->Annz    = Annz;
6746:   coo->Bnnz    = Bnnz;
6747:   coo->Annz2   = Annz2;
6748:   coo->Bnnz2   = Bnnz2;
6749:   coo->Atot1   = Atot1;
6750:   coo->Atot2   = Atot2;
6751:   coo->Btot1   = Btot1;
6752:   coo->Btot2   = Btot2;
6753:   coo->Ajmap1  = Ajmap1;
6754:   coo->Aperm1  = Aperm1;
6755:   coo->Bjmap1  = Bjmap1;
6756:   coo->Bperm1  = Bperm1;
6757:   coo->Aimap2  = Aimap2;
6758:   coo->Ajmap2  = Ajmap2;
6759:   coo->Aperm2  = Aperm2;
6760:   coo->Bimap2  = Bimap2;
6761:   coo->Bjmap2  = Bjmap2;
6762:   coo->Bperm2  = Bperm2;
6763:   coo->Cperm1  = Cperm1;
6764:   // Allocate in preallocation. If not used, it has zero cost on host
6765:   PetscCall(PetscMalloc2(coo->sendlen, &coo->sendbuf, coo->recvlen, &coo->recvbuf));
6766:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
6767:   PetscCall(PetscContainerSetPointer(container, coo));
6768:   PetscCall(PetscContainerSetCtxDestroy(container, MatCOOStructDestroy_MPIAIJ));
6769:   PetscCall(PetscObjectCompose((PetscObject)mat, "__PETSc_MatCOOStruct_Host", (PetscObject)container));
6770:   PetscCall(PetscContainerDestroy(&container));
6771:   PetscFunctionReturn(PETSC_SUCCESS);
6772: }

6774: static PetscErrorCode MatSetValuesCOO_MPIAIJ(Mat mat, const PetscScalar v[], InsertMode imode)
6775: {
6776:   Mat_MPIAIJ          *mpiaij = (Mat_MPIAIJ *)mat->data;
6777:   Mat                  A = mpiaij->A, B = mpiaij->B;
6778:   PetscScalar         *Aa, *Ba;
6779:   PetscScalar         *sendbuf, *recvbuf;
6780:   const PetscCount    *Ajmap1, *Ajmap2, *Aimap2;
6781:   const PetscCount    *Bjmap1, *Bjmap2, *Bimap2;
6782:   const PetscCount    *Aperm1, *Aperm2, *Bperm1, *Bperm2;
6783:   const PetscCount    *Cperm1;
6784:   PetscContainer       container;
6785:   MatCOOStruct_MPIAIJ *coo;

6787:   PetscFunctionBegin;
6788:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", (PetscObject *)&container));
6789:   PetscCheck(container, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Not found MatCOOStruct on this matrix");
6790:   PetscCall(PetscContainerGetPointer(container, (void **)&coo));
6791:   sendbuf = coo->sendbuf;
6792:   recvbuf = coo->recvbuf;
6793:   Ajmap1  = coo->Ajmap1;
6794:   Ajmap2  = coo->Ajmap2;
6795:   Aimap2  = coo->Aimap2;
6796:   Bjmap1  = coo->Bjmap1;
6797:   Bjmap2  = coo->Bjmap2;
6798:   Bimap2  = coo->Bimap2;
6799:   Aperm1  = coo->Aperm1;
6800:   Aperm2  = coo->Aperm2;
6801:   Bperm1  = coo->Bperm1;
6802:   Bperm2  = coo->Bperm2;
6803:   Cperm1  = coo->Cperm1;

6805:   PetscCall(MatSeqAIJGetArray(A, &Aa)); /* Might read and write matrix values */
6806:   PetscCall(MatSeqAIJGetArray(B, &Ba));

6808:   /* Pack entries to be sent to remote */
6809:   for (PetscCount i = 0; i < coo->sendlen; i++) sendbuf[i] = v[Cperm1[i]];

6811:   /* Send remote entries to their owner and overlap the communication with local computation */
6812:   PetscCall(PetscSFReduceWithMemTypeBegin(coo->sf, MPIU_SCALAR, PETSC_MEMTYPE_HOST, sendbuf, PETSC_MEMTYPE_HOST, recvbuf, MPI_REPLACE));
6813:   /* Add local entries to A and B */
6814:   for (PetscCount i = 0; i < coo->Annz; i++) { /* All nonzeros in A are either zero'ed or added with a value (i.e., initialized) */
6815:     PetscScalar sum = 0.0;                     /* Do partial summation first to improve numerical stability */
6816:     for (PetscCount k = Ajmap1[i]; k < Ajmap1[i + 1]; k++) sum += v[Aperm1[k]];
6817:     Aa[i] = (imode == INSERT_VALUES ? 0.0 : Aa[i]) + sum;
6818:   }
6819:   for (PetscCount i = 0; i < coo->Bnnz; i++) {
6820:     PetscScalar sum = 0.0;
6821:     for (PetscCount k = Bjmap1[i]; k < Bjmap1[i + 1]; k++) sum += v[Bperm1[k]];
6822:     Ba[i] = (imode == INSERT_VALUES ? 0.0 : Ba[i]) + sum;
6823:   }
6824:   PetscCall(PetscSFReduceEnd(coo->sf, MPIU_SCALAR, sendbuf, recvbuf, MPI_REPLACE));

6826:   /* Add received remote entries to A and B */
6827:   for (PetscCount i = 0; i < coo->Annz2; i++) {
6828:     for (PetscCount k = Ajmap2[i]; k < Ajmap2[i + 1]; k++) Aa[Aimap2[i]] += recvbuf[Aperm2[k]];
6829:   }
6830:   for (PetscCount i = 0; i < coo->Bnnz2; i++) {
6831:     for (PetscCount k = Bjmap2[i]; k < Bjmap2[i + 1]; k++) Ba[Bimap2[i]] += recvbuf[Bperm2[k]];
6832:   }
6833:   PetscCall(MatSeqAIJRestoreArray(A, &Aa));
6834:   PetscCall(MatSeqAIJRestoreArray(B, &Ba));
6835:   PetscFunctionReturn(PETSC_SUCCESS);
6836: }

6838: /*MC
6839:    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.

6841:    Options Database Keys:
6842: . -mat_type mpiaij - sets the matrix type to `MATMPIAIJ` during a call to `MatSetFromOptions()`

6844:    Level: beginner

6846:    Notes:
6847:    `MatSetValues()` may be called for this matrix type with a `NULL` argument for the numerical values,
6848:     in this case the values associated with the rows and columns one passes in are set to zero
6849:     in the matrix

6851:     `MatSetOptions`(,`MAT_STRUCTURE_ONLY`,`PETSC_TRUE`) may be called for this matrix type. In this no
6852:     space is allocated for the nonzero entries and any entries passed with `MatSetValues()` are ignored

6854: .seealso: [](ch_matrices), `Mat`, `MATSEQAIJ`, `MATAIJ`, `MatCreateAIJ()`
6855: M*/
6856: PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
6857: {
6858:   Mat_MPIAIJ *b;
6859:   PetscMPIInt size;

6861:   PetscFunctionBegin;
6862:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)B), &size));

6864:   PetscCall(PetscNew(&b));
6865:   B->data       = (void *)b;
6866:   B->ops[0]     = MatOps_Values;
6867:   B->assembled  = PETSC_FALSE;
6868:   B->insertmode = NOT_SET_VALUES;
6869:   b->size       = size;

6871:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)B), &b->rank));

6873:   /* build cache for off array entries formed */
6874:   PetscCall(MatStashCreate_Private(PetscObjectComm((PetscObject)B), 1, &B->stash));

6876:   b->donotstash  = PETSC_FALSE;
6877:   b->colmap      = NULL;
6878:   b->garray      = NULL;
6879:   b->roworiented = PETSC_TRUE;

6881:   /* stuff used for matrix vector multiply */
6882:   b->lvec  = NULL;
6883:   b->Mvctx = NULL;

6885:   /* stuff for MatGetRow() */
6886:   b->rowindices   = NULL;
6887:   b->rowvalues    = NULL;
6888:   b->getrowactive = PETSC_FALSE;

6890:   /* flexible pointer used in CUSPARSE classes */
6891:   b->spptr = NULL;

6893:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatMPIAIJSetUseScalableIncreaseOverlap_C", MatMPIAIJSetUseScalableIncreaseOverlap_MPIAIJ));
6894:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatStoreValues_C", MatStoreValues_MPIAIJ));
6895:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatRetrieveValues_C", MatRetrieveValues_MPIAIJ));
6896:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsTranspose_C", MatIsTranspose_MPIAIJ));
6897:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatMPIAIJSetPreallocation_C", MatMPIAIJSetPreallocation_MPIAIJ));
6898:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatResetPreallocation_C", MatResetPreallocation_MPIAIJ));
6899:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatResetHash_C", MatResetHash_MPIAIJ));
6900:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatMPIAIJSetPreallocationCSR_C", MatMPIAIJSetPreallocationCSR_MPIAIJ));
6901:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatDiagonalScaleLocal_C", MatDiagonalScaleLocal_MPIAIJ));
6902:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijperm_C", MatConvert_MPIAIJ_MPIAIJPERM));
6903:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijsell_C", MatConvert_MPIAIJ_MPIAIJSELL));
6904: #if defined(PETSC_HAVE_CUDA)
6905:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijcusparse_C", MatConvert_MPIAIJ_MPIAIJCUSPARSE));
6906: #endif
6907: #if defined(PETSC_HAVE_HIP)
6908:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijhipsparse_C", MatConvert_MPIAIJ_MPIAIJHIPSPARSE));
6909: #endif
6910: #if defined(PETSC_HAVE_KOKKOS_KERNELS)
6911:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijkokkos_C", MatConvert_MPIAIJ_MPIAIJKokkos));
6912: #endif
6913: #if defined(PETSC_HAVE_MKL_SPARSE)
6914:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijmkl_C", MatConvert_MPIAIJ_MPIAIJMKL));
6915: #endif
6916:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpiaijcrl_C", MatConvert_MPIAIJ_MPIAIJCRL));
6917:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpibaij_C", MatConvert_MPIAIJ_MPIBAIJ));
6918:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpisbaij_C", MatConvert_MPIAIJ_MPISBAIJ));
6919:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpidense_C", MatConvert_MPIAIJ_MPIDense));
6920: #if defined(PETSC_HAVE_ELEMENTAL)
6921:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_elemental_C", MatConvert_MPIAIJ_Elemental));
6922: #endif
6923: #if defined(PETSC_HAVE_SCALAPACK)
6924:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_scalapack_C", MatConvert_AIJ_ScaLAPACK));
6925: #endif
6926:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_is_C", MatConvert_XAIJ_IS));
6927:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_mpisell_C", MatConvert_MPIAIJ_MPISELL));
6928: #if defined(PETSC_HAVE_HYPRE)
6929:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_mpiaij_hypre_C", MatConvert_AIJ_HYPRE));
6930:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_transpose_mpiaij_mpiaij_C", MatProductSetFromOptions_Transpose_AIJ_AIJ));
6931: #endif
6932:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_is_mpiaij_C", MatProductSetFromOptions_IS_XAIJ));
6933:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_mpiaij_mpiaij_C", MatProductSetFromOptions_MPIAIJ));
6934:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetPreallocationCOO_C", MatSetPreallocationCOO_MPIAIJ));
6935:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetValuesCOO_C", MatSetValuesCOO_MPIAIJ));
6936:   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATMPIAIJ));
6937:   PetscFunctionReturn(PETSC_SUCCESS);
6938: }

6940: /*@
6941:   MatCreateMPIAIJWithSplitArrays - creates a `MATMPIAIJ` matrix using arrays that contain the "diagonal"
6942:   and "off-diagonal" part of the matrix in CSR format.

6944:   Collective

6946:   Input Parameters:
6947: + comm - MPI communicator
6948: . m    - number of local rows (Cannot be `PETSC_DECIDE`)
6949: . n    - This value should be the same as the local size used in creating the
6950:          x vector for the matrix-vector product $y = Ax$. (or `PETSC_DECIDE` to have
6951:          calculated if `N` is given) For square matrices `n` is almost always `m`.
6952: . M    - number of global rows (or `PETSC_DETERMINE` to have calculated if `m` is given)
6953: . N    - number of global columns (or `PETSC_DETERMINE` to have calculated if `n` is given)
6954: . i    - row indices for "diagonal" portion of matrix; that is i[0] = 0, i[row] = i[row-1] + number of elements in that row of the matrix
6955: . j    - column indices, which must be local, i.e., based off the start column of the diagonal portion
6956: . a    - matrix values
6957: . oi   - row indices for "off-diagonal" portion of matrix; that is oi[0] = 0, oi[row] = oi[row-1] + number of elements in that row of the matrix
6958: . oj   - column indices, which must be global, representing global columns in the `MATMPIAIJ` matrix
6959: - oa   - matrix values

6961:   Output Parameter:
6962: . mat - the matrix

6964:   Level: advanced

6966:   Notes:
6967:   The `i`, `j`, and `a` arrays ARE NOT copied by this routine into the internal format used by PETSc (even in Fortran). The user
6968:   must free the arrays once the matrix has been destroyed and not before.

6970:   The `i` and `j` indices are 0 based

6972:   See `MatCreateAIJ()` for the definition of "diagonal" and "off-diagonal" portion of the matrix

6974:   This sets local rows and cannot be used to set off-processor values.

6976:   Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
6977:   legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
6978:   not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
6979:   the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
6980:   keep track of the underlying array. Use `MatSetOption`(A,`MAT_NO_OFF_PROC_ENTRIES`,`PETSC_TRUE`) to disable all
6981:   communication if it is known that only local entries will be set.

6983: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`,
6984:           `MATMPIAIJ`, `MatCreateAIJ()`, `MatCreateMPIAIJWithArrays()`
6985: @*/
6986: PetscErrorCode MatCreateMPIAIJWithSplitArrays(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscInt i[], PetscInt j[], PetscScalar a[], PetscInt oi[], PetscInt oj[], PetscScalar oa[], Mat *mat)
6987: {
6988:   Mat_MPIAIJ *maij;

6990:   PetscFunctionBegin;
6991:   PetscCheck(m >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "local number of rows (m) cannot be PETSC_DECIDE, or negative");
6992:   PetscCheck(i[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
6993:   PetscCheck(oi[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "oi (row indices) must start with 0");
6994:   PetscCall(MatCreate(comm, mat));
6995:   PetscCall(MatSetSizes(*mat, m, n, M, N));
6996:   PetscCall(MatSetType(*mat, MATMPIAIJ));
6997:   maij = (Mat_MPIAIJ *)(*mat)->data;

6999:   (*mat)->preallocated = PETSC_TRUE;

7001:   PetscCall(PetscLayoutSetUp((*mat)->rmap));
7002:   PetscCall(PetscLayoutSetUp((*mat)->cmap));

7004:   PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, m, n, i, j, a, &maij->A));
7005:   PetscCall(MatCreateSeqAIJWithArrays(PETSC_COMM_SELF, m, (*mat)->cmap->N, oi, oj, oa, &maij->B));

7007:   PetscCall(MatSetOption(*mat, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
7008:   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
7009:   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
7010:   PetscCall(MatSetOption(*mat, MAT_NO_OFF_PROC_ENTRIES, PETSC_FALSE));
7011:   PetscCall(MatSetOption(*mat, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
7012:   PetscFunctionReturn(PETSC_SUCCESS);
7013: }

7015: typedef struct {
7016:   Mat       *mp;    /* intermediate products */
7017:   PetscBool *mptmp; /* is the intermediate product temporary ? */
7018:   PetscInt   cp;    /* number of intermediate products */

7020:   /* support for MatGetBrowsOfAoCols_MPIAIJ for P_oth */
7021:   PetscInt    *startsj_s, *startsj_r;
7022:   PetscScalar *bufa;
7023:   Mat          P_oth;

7025:   /* may take advantage of merging product->B */
7026:   Mat Bloc; /* B-local by merging diag and off-diag */

7028:   /* cusparse does not have support to split between symbolic and numeric phases.
7029:      When api_user is true, we don't need to update the numerical values
7030:      of the temporary storage */
7031:   PetscBool reusesym;

7033:   /* support for COO values insertion */
7034:   PetscScalar *coo_v, *coo_w; /* store on-process and off-process COO scalars, and used as MPI recv/send buffers respectively */
7035:   PetscInt   **own;           /* own[i] points to address of on-process COO indices for Mat mp[i] */
7036:   PetscInt   **off;           /* off[i] points to address of off-process COO indices for Mat mp[i] */
7037:   PetscBool    hasoffproc;    /* if true, have off-process values insertion (i.e. AtB or PtAP) */
7038:   PetscSF      sf;            /* used for non-local values insertion and memory malloc */
7039:   PetscMemType mtype;

7041:   /* customization */
7042:   PetscBool abmerge;
7043:   PetscBool P_oth_bind;
7044: } MatMatMPIAIJBACKEND;

7046: static PetscErrorCode MatDestroy_MatMatMPIAIJBACKEND(void *data)
7047: {
7048:   MatMatMPIAIJBACKEND *mmdata = (MatMatMPIAIJBACKEND *)data;
7049:   PetscInt             i;

7051:   PetscFunctionBegin;
7052:   PetscCall(PetscFree2(mmdata->startsj_s, mmdata->startsj_r));
7053:   PetscCall(PetscFree(mmdata->bufa));
7054:   PetscCall(PetscSFFree(mmdata->sf, mmdata->mtype, mmdata->coo_v));
7055:   PetscCall(PetscSFFree(mmdata->sf, mmdata->mtype, mmdata->coo_w));
7056:   PetscCall(MatDestroy(&mmdata->P_oth));
7057:   PetscCall(MatDestroy(&mmdata->Bloc));
7058:   PetscCall(PetscSFDestroy(&mmdata->sf));
7059:   for (i = 0; i < mmdata->cp; i++) PetscCall(MatDestroy(&mmdata->mp[i]));
7060:   PetscCall(PetscFree2(mmdata->mp, mmdata->mptmp));
7061:   PetscCall(PetscFree(mmdata->own[0]));
7062:   PetscCall(PetscFree(mmdata->own));
7063:   PetscCall(PetscFree(mmdata->off[0]));
7064:   PetscCall(PetscFree(mmdata->off));
7065:   PetscCall(PetscFree(mmdata));
7066:   PetscFunctionReturn(PETSC_SUCCESS);
7067: }

7069: /* Copy selected n entries with indices in idx[] of A to v[].
7070:    If idx is NULL, copy the whole data array of A to v[]
7071:  */
7072: static PetscErrorCode MatSeqAIJCopySubArray(Mat A, PetscInt n, const PetscInt idx[], PetscScalar v[])
7073: {
7074:   PetscErrorCode (*f)(Mat, PetscInt, const PetscInt[], PetscScalar[]);

7076:   PetscFunctionBegin;
7077:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatSeqAIJCopySubArray_C", &f));
7078:   if (f) {
7079:     PetscCall((*f)(A, n, idx, v));
7080:   } else {
7081:     const PetscScalar *vv;

7083:     PetscCall(MatSeqAIJGetArrayRead(A, &vv));
7084:     if (n && idx) {
7085:       PetscScalar    *w  = v;
7086:       const PetscInt *oi = idx;
7087:       PetscInt        j;

7089:       for (j = 0; j < n; j++) *w++ = vv[*oi++];
7090:     } else {
7091:       PetscCall(PetscArraycpy(v, vv, n));
7092:     }
7093:     PetscCall(MatSeqAIJRestoreArrayRead(A, &vv));
7094:   }
7095:   PetscFunctionReturn(PETSC_SUCCESS);
7096: }

7098: static PetscErrorCode MatProductNumeric_MPIAIJBACKEND(Mat C)
7099: {
7100:   MatMatMPIAIJBACKEND *mmdata;
7101:   PetscInt             i, n_d, n_o;

7103:   PetscFunctionBegin;
7104:   MatCheckProduct(C, 1);
7105:   PetscCheck(C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
7106:   mmdata = (MatMatMPIAIJBACKEND *)C->product->data;
7107:   if (!mmdata->reusesym) { /* update temporary matrices */
7108:     if (mmdata->P_oth) PetscCall(MatGetBrowsOfAoCols_MPIAIJ(C->product->A, C->product->B, MAT_REUSE_MATRIX, &mmdata->startsj_s, &mmdata->startsj_r, &mmdata->bufa, &mmdata->P_oth));
7109:     if (mmdata->Bloc) PetscCall(MatMPIAIJGetLocalMatMerge(C->product->B, MAT_REUSE_MATRIX, NULL, &mmdata->Bloc));
7110:   }
7111:   mmdata->reusesym = PETSC_FALSE;

7113:   for (i = 0; i < mmdata->cp; i++) {
7114:     PetscCheck(mmdata->mp[i]->ops->productnumeric, PetscObjectComm((PetscObject)mmdata->mp[i]), PETSC_ERR_PLIB, "Missing numeric op for %s", MatProductTypes[mmdata->mp[i]->product->type]);
7115:     PetscCall((*mmdata->mp[i]->ops->productnumeric)(mmdata->mp[i]));
7116:   }
7117:   for (i = 0, n_d = 0, n_o = 0; i < mmdata->cp; i++) {
7118:     PetscInt noff;

7120:     PetscCall(PetscIntCast(mmdata->off[i + 1] - mmdata->off[i], &noff));
7121:     if (mmdata->mptmp[i]) continue;
7122:     if (noff) {
7123:       PetscInt nown;

7125:       PetscCall(PetscIntCast(mmdata->own[i + 1] - mmdata->own[i], &nown));
7126:       PetscCall(MatSeqAIJCopySubArray(mmdata->mp[i], noff, mmdata->off[i], mmdata->coo_w + n_o));
7127:       PetscCall(MatSeqAIJCopySubArray(mmdata->mp[i], nown, mmdata->own[i], mmdata->coo_v + n_d));
7128:       n_o += noff;
7129:       n_d += nown;
7130:     } else {
7131:       Mat_SeqAIJ *mm = (Mat_SeqAIJ *)mmdata->mp[i]->data;

7133:       PetscCall(MatSeqAIJCopySubArray(mmdata->mp[i], mm->nz, NULL, mmdata->coo_v + n_d));
7134:       n_d += mm->nz;
7135:     }
7136:   }
7137:   if (mmdata->hasoffproc) { /* offprocess insertion */
7138:     PetscCall(PetscSFGatherBegin(mmdata->sf, MPIU_SCALAR, mmdata->coo_w, mmdata->coo_v + n_d));
7139:     PetscCall(PetscSFGatherEnd(mmdata->sf, MPIU_SCALAR, mmdata->coo_w, mmdata->coo_v + n_d));
7140:   }
7141:   PetscCall(MatSetValuesCOO(C, mmdata->coo_v, INSERT_VALUES));
7142:   PetscFunctionReturn(PETSC_SUCCESS);
7143: }

7145: /* Support for Pt * A, A * P, or Pt * A * P */
7146: #define MAX_NUMBER_INTERMEDIATE 4
7147: PetscErrorCode MatProductSymbolic_MPIAIJBACKEND(Mat C)
7148: {
7149:   Mat_Product           *product = C->product;
7150:   Mat                    A, P, mp[MAX_NUMBER_INTERMEDIATE]; /* A, P and a series of intermediate matrices */
7151:   Mat_MPIAIJ            *a, *p;
7152:   MatMatMPIAIJBACKEND   *mmdata;
7153:   ISLocalToGlobalMapping P_oth_l2g = NULL;
7154:   IS                     glob      = NULL;
7155:   const char            *prefix;
7156:   char                   pprefix[256];
7157:   const PetscInt        *globidx, *P_oth_idx;
7158:   PetscInt               i, j, cp, m, n, M, N, *coo_i, *coo_j;
7159:   PetscCount             ncoo, ncoo_d, ncoo_o, ncoo_oown;
7160:   PetscInt               cmapt[MAX_NUMBER_INTERMEDIATE], rmapt[MAX_NUMBER_INTERMEDIATE]; /* col/row map type for each Mat in mp[]. */
7161:                                                                                          /* type-0: consecutive, start from 0; type-1: consecutive with */
7162:                                                                                          /* a base offset; type-2: sparse with a local to global map table */
7163:   const PetscInt *cmapa[MAX_NUMBER_INTERMEDIATE], *rmapa[MAX_NUMBER_INTERMEDIATE];       /* col/row local to global map array (table) for type-2 map type */

7165:   MatProductType ptype;
7166:   PetscBool      mptmp[MAX_NUMBER_INTERMEDIATE], hasoffproc = PETSC_FALSE, iscuda, iship, iskokk;
7167:   PetscMPIInt    size;

7169:   PetscFunctionBegin;
7170:   MatCheckProduct(C, 1);
7171:   PetscCheck(!product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
7172:   ptype = product->type;
7173:   if (product->A->symmetric == PETSC_BOOL3_TRUE && ptype == MATPRODUCT_AtB) {
7174:     ptype                                          = MATPRODUCT_AB;
7175:     product->symbolic_used_the_fact_A_is_symmetric = PETSC_TRUE;
7176:   }
7177:   switch (ptype) {
7178:   case MATPRODUCT_AB:
7179:     A          = product->A;
7180:     P          = product->B;
7181:     m          = A->rmap->n;
7182:     n          = P->cmap->n;
7183:     M          = A->rmap->N;
7184:     N          = P->cmap->N;
7185:     hasoffproc = PETSC_FALSE; /* will not scatter mat product values to other processes */
7186:     break;
7187:   case MATPRODUCT_AtB:
7188:     P          = product->A;
7189:     A          = product->B;
7190:     m          = P->cmap->n;
7191:     n          = A->cmap->n;
7192:     M          = P->cmap->N;
7193:     N          = A->cmap->N;
7194:     hasoffproc = PETSC_TRUE;
7195:     break;
7196:   case MATPRODUCT_PtAP:
7197:     A          = product->A;
7198:     P          = product->B;
7199:     m          = P->cmap->n;
7200:     n          = P->cmap->n;
7201:     M          = P->cmap->N;
7202:     N          = P->cmap->N;
7203:     hasoffproc = PETSC_TRUE;
7204:     break;
7205:   default:
7206:     SETERRQ(PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Not for product type %s", MatProductTypes[ptype]);
7207:   }
7208:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)C), &size));
7209:   if (size == 1) hasoffproc = PETSC_FALSE;

7211:   /* defaults */
7212:   for (i = 0; i < MAX_NUMBER_INTERMEDIATE; i++) {
7213:     mp[i]    = NULL;
7214:     mptmp[i] = PETSC_FALSE;
7215:     rmapt[i] = -1;
7216:     cmapt[i] = -1;
7217:     rmapa[i] = NULL;
7218:     cmapa[i] = NULL;
7219:   }

7221:   /* customization */
7222:   PetscCall(PetscNew(&mmdata));
7223:   mmdata->reusesym = product->api_user;
7224:   if (ptype == MATPRODUCT_AB) {
7225:     if (product->api_user) {
7226:       PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatMatMult", "Mat");
7227:       PetscCall(PetscOptionsBool("-matmatmult_backend_mergeB", "Merge product->B local matrices", "MatMatMult", mmdata->abmerge, &mmdata->abmerge, NULL));
7228:       PetscCall(PetscOptionsBool("-matmatmult_backend_pothbind", "Bind P_oth to CPU", "MatBindToCPU", mmdata->P_oth_bind, &mmdata->P_oth_bind, NULL));
7229:       PetscOptionsEnd();
7230:     } else {
7231:       PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_AB", "Mat");
7232:       PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_mergeB", "Merge product->B local matrices", "MatMatMult", mmdata->abmerge, &mmdata->abmerge, NULL));
7233:       PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_pothbind", "Bind P_oth to CPU", "MatBindToCPU", mmdata->P_oth_bind, &mmdata->P_oth_bind, NULL));
7234:       PetscOptionsEnd();
7235:     }
7236:   } else if (ptype == MATPRODUCT_PtAP) {
7237:     if (product->api_user) {
7238:       PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatPtAP", "Mat");
7239:       PetscCall(PetscOptionsBool("-matptap_backend_pothbind", "Bind P_oth to CPU", "MatBindToCPU", mmdata->P_oth_bind, &mmdata->P_oth_bind, NULL));
7240:       PetscOptionsEnd();
7241:     } else {
7242:       PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_PtAP", "Mat");
7243:       PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_pothbind", "Bind P_oth to CPU", "MatBindToCPU", mmdata->P_oth_bind, &mmdata->P_oth_bind, NULL));
7244:       PetscOptionsEnd();
7245:     }
7246:   }
7247:   a = (Mat_MPIAIJ *)A->data;
7248:   p = (Mat_MPIAIJ *)P->data;
7249:   PetscCall(MatSetSizes(C, m, n, M, N));
7250:   PetscCall(PetscLayoutSetUp(C->rmap));
7251:   PetscCall(PetscLayoutSetUp(C->cmap));
7252:   PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
7253:   PetscCall(MatGetOptionsPrefix(C, &prefix));

7255:   cp = 0;
7256:   switch (ptype) {
7257:   case MATPRODUCT_AB: /* A * P */
7258:     PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &mmdata->startsj_s, &mmdata->startsj_r, &mmdata->bufa, &mmdata->P_oth));

7260:     /* A_diag * P_local (merged or not) */
7261:     if (mmdata->abmerge) { /* P's diagonal and off-diag blocks are merged to one matrix, then multiplied by A_diag */
7262:       /* P is product->B */
7263:       PetscCall(MatMPIAIJGetLocalMatMerge(P, MAT_INITIAL_MATRIX, &glob, &mmdata->Bloc));
7264:       PetscCall(MatProductCreate(a->A, mmdata->Bloc, NULL, &mp[cp]));
7265:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AB));
7266:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7267:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7268:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7269:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7270:       mp[cp]->product->api_user = product->api_user;
7271:       PetscCall(MatProductSetFromOptions(mp[cp]));
7272:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7273:       PetscCall(ISGetIndices(glob, &globidx));
7274:       rmapt[cp] = 1;
7275:       cmapt[cp] = 2;
7276:       cmapa[cp] = globidx;
7277:       mptmp[cp] = PETSC_FALSE;
7278:       cp++;
7279:     } else { /* A_diag * P_diag and A_diag * P_off */
7280:       PetscCall(MatProductCreate(a->A, p->A, NULL, &mp[cp]));
7281:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AB));
7282:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7283:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7284:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7285:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7286:       mp[cp]->product->api_user = product->api_user;
7287:       PetscCall(MatProductSetFromOptions(mp[cp]));
7288:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7289:       rmapt[cp] = 1;
7290:       cmapt[cp] = 1;
7291:       mptmp[cp] = PETSC_FALSE;
7292:       cp++;
7293:       PetscCall(MatProductCreate(a->A, p->B, NULL, &mp[cp]));
7294:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AB));
7295:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7296:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7297:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7298:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7299:       mp[cp]->product->api_user = product->api_user;
7300:       PetscCall(MatProductSetFromOptions(mp[cp]));
7301:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7302:       rmapt[cp] = 1;
7303:       cmapt[cp] = 2;
7304:       cmapa[cp] = p->garray;
7305:       mptmp[cp] = PETSC_FALSE;
7306:       cp++;
7307:     }

7309:     /* A_off * P_other */
7310:     if (mmdata->P_oth) {
7311:       PetscCall(MatSeqAIJCompactOutExtraColumns_SeqAIJ(mmdata->P_oth, &P_oth_l2g)); /* make P_oth use local col ids */
7312:       PetscCall(ISLocalToGlobalMappingGetIndices(P_oth_l2g, &P_oth_idx));
7313:       PetscCall(MatSetType(mmdata->P_oth, ((PetscObject)a->B)->type_name));
7314:       PetscCall(MatBindToCPU(mmdata->P_oth, mmdata->P_oth_bind));
7315:       PetscCall(MatProductCreate(a->B, mmdata->P_oth, NULL, &mp[cp]));
7316:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AB));
7317:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7318:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7319:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7320:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7321:       mp[cp]->product->api_user = product->api_user;
7322:       PetscCall(MatProductSetFromOptions(mp[cp]));
7323:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7324:       rmapt[cp] = 1;
7325:       cmapt[cp] = 2;
7326:       cmapa[cp] = P_oth_idx;
7327:       mptmp[cp] = PETSC_FALSE;
7328:       cp++;
7329:     }
7330:     break;

7332:   case MATPRODUCT_AtB: /* (P^t * A): P_diag * A_loc + P_off * A_loc */
7333:     /* A is product->B */
7334:     PetscCall(MatMPIAIJGetLocalMatMerge(A, MAT_INITIAL_MATRIX, &glob, &mmdata->Bloc));
7335:     if (A == P) { /* when A==P, we can take advantage of the already merged mmdata->Bloc */
7336:       PetscCall(MatProductCreate(mmdata->Bloc, mmdata->Bloc, NULL, &mp[cp]));
7337:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AtB));
7338:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7339:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7340:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7341:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7342:       mp[cp]->product->api_user = product->api_user;
7343:       PetscCall(MatProductSetFromOptions(mp[cp]));
7344:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7345:       PetscCall(ISGetIndices(glob, &globidx));
7346:       rmapt[cp] = 2;
7347:       rmapa[cp] = globidx;
7348:       cmapt[cp] = 2;
7349:       cmapa[cp] = globidx;
7350:       mptmp[cp] = PETSC_FALSE;
7351:       cp++;
7352:     } else {
7353:       PetscCall(MatProductCreate(p->A, mmdata->Bloc, NULL, &mp[cp]));
7354:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AtB));
7355:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7356:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7357:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7358:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7359:       mp[cp]->product->api_user = product->api_user;
7360:       PetscCall(MatProductSetFromOptions(mp[cp]));
7361:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7362:       PetscCall(ISGetIndices(glob, &globidx));
7363:       rmapt[cp] = 1;
7364:       cmapt[cp] = 2;
7365:       cmapa[cp] = globidx;
7366:       mptmp[cp] = PETSC_FALSE;
7367:       cp++;
7368:       PetscCall(MatProductCreate(p->B, mmdata->Bloc, NULL, &mp[cp]));
7369:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AtB));
7370:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7371:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7372:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7373:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7374:       mp[cp]->product->api_user = product->api_user;
7375:       PetscCall(MatProductSetFromOptions(mp[cp]));
7376:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7377:       rmapt[cp] = 2;
7378:       rmapa[cp] = p->garray;
7379:       cmapt[cp] = 2;
7380:       cmapa[cp] = globidx;
7381:       mptmp[cp] = PETSC_FALSE;
7382:       cp++;
7383:     }
7384:     break;
7385:   case MATPRODUCT_PtAP:
7386:     PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &mmdata->startsj_s, &mmdata->startsj_r, &mmdata->bufa, &mmdata->P_oth));
7387:     /* P is product->B */
7388:     PetscCall(MatMPIAIJGetLocalMatMerge(P, MAT_INITIAL_MATRIX, &glob, &mmdata->Bloc));
7389:     PetscCall(MatProductCreate(a->A, mmdata->Bloc, NULL, &mp[cp]));
7390:     PetscCall(MatProductSetType(mp[cp], MATPRODUCT_PtAP));
7391:     PetscCall(MatProductSetFill(mp[cp], product->fill));
7392:     PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7393:     PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7394:     PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7395:     mp[cp]->product->api_user = product->api_user;
7396:     PetscCall(MatProductSetFromOptions(mp[cp]));
7397:     PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7398:     PetscCall(ISGetIndices(glob, &globidx));
7399:     rmapt[cp] = 2;
7400:     rmapa[cp] = globidx;
7401:     cmapt[cp] = 2;
7402:     cmapa[cp] = globidx;
7403:     mptmp[cp] = PETSC_FALSE;
7404:     cp++;
7405:     if (mmdata->P_oth) {
7406:       PetscCall(MatSeqAIJCompactOutExtraColumns_SeqAIJ(mmdata->P_oth, &P_oth_l2g));
7407:       PetscCall(ISLocalToGlobalMappingGetIndices(P_oth_l2g, &P_oth_idx));
7408:       PetscCall(MatSetType(mmdata->P_oth, ((PetscObject)a->B)->type_name));
7409:       PetscCall(MatBindToCPU(mmdata->P_oth, mmdata->P_oth_bind));
7410:       PetscCall(MatProductCreate(a->B, mmdata->P_oth, NULL, &mp[cp]));
7411:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AB));
7412:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7413:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7414:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7415:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7416:       mp[cp]->product->api_user = product->api_user;
7417:       PetscCall(MatProductSetFromOptions(mp[cp]));
7418:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7419:       mptmp[cp] = PETSC_TRUE;
7420:       cp++;
7421:       PetscCall(MatProductCreate(mmdata->Bloc, mp[1], NULL, &mp[cp]));
7422:       PetscCall(MatProductSetType(mp[cp], MATPRODUCT_AtB));
7423:       PetscCall(MatProductSetFill(mp[cp], product->fill));
7424:       PetscCall(PetscSNPrintf(pprefix, sizeof(pprefix), "backend_p%" PetscInt_FMT "_", cp));
7425:       PetscCall(MatSetOptionsPrefix(mp[cp], prefix));
7426:       PetscCall(MatAppendOptionsPrefix(mp[cp], pprefix));
7427:       mp[cp]->product->api_user = product->api_user;
7428:       PetscCall(MatProductSetFromOptions(mp[cp]));
7429:       PetscCall((*mp[cp]->ops->productsymbolic)(mp[cp]));
7430:       rmapt[cp] = 2;
7431:       rmapa[cp] = globidx;
7432:       cmapt[cp] = 2;
7433:       cmapa[cp] = P_oth_idx;
7434:       mptmp[cp] = PETSC_FALSE;
7435:       cp++;
7436:     }
7437:     break;
7438:   default:
7439:     SETERRQ(PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Not for product type %s", MatProductTypes[ptype]);
7440:   }
7441:   /* sanity check */
7442:   if (size > 1)
7443:     for (i = 0; i < cp; i++) PetscCheck(rmapt[i] != 2 || hasoffproc, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unexpected offproc map type for product %" PetscInt_FMT, i);

7445:   PetscCall(PetscMalloc2(cp, &mmdata->mp, cp, &mmdata->mptmp));
7446:   for (i = 0; i < cp; i++) {
7447:     mmdata->mp[i]    = mp[i];
7448:     mmdata->mptmp[i] = mptmp[i];
7449:   }
7450:   mmdata->cp             = cp;
7451:   C->product->data       = mmdata;
7452:   C->product->destroy    = MatDestroy_MatMatMPIAIJBACKEND;
7453:   C->ops->productnumeric = MatProductNumeric_MPIAIJBACKEND;

7455:   /* memory type */
7456:   mmdata->mtype = PETSC_MEMTYPE_HOST;
7457:   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &iscuda, MATSEQAIJCUSPARSE, MATMPIAIJCUSPARSE, ""));
7458:   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &iship, MATSEQAIJHIPSPARSE, MATMPIAIJHIPSPARSE, ""));
7459:   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &iskokk, MATSEQAIJKOKKOS, MATMPIAIJKOKKOS, ""));
7460:   if (iscuda) mmdata->mtype = PETSC_MEMTYPE_CUDA;
7461:   else if (iship) mmdata->mtype = PETSC_MEMTYPE_HIP;
7462:   else if (iskokk) mmdata->mtype = PETSC_MEMTYPE_KOKKOS;

7464:   /* prepare coo coordinates for values insertion */

7466:   /* count total nonzeros of those intermediate seqaij Mats
7467:     ncoo_d:    # of nonzeros of matrices that do not have offproc entries
7468:     ncoo_o:    # of nonzeros (of matrices that might have offproc entries) that will be inserted to remote procs
7469:     ncoo_oown: # of nonzeros (of matrices that might have offproc entries) that will be inserted locally
7470:   */
7471:   for (cp = 0, ncoo_d = 0, ncoo_o = 0, ncoo_oown = 0; cp < mmdata->cp; cp++) {
7472:     Mat_SeqAIJ *mm = (Mat_SeqAIJ *)mp[cp]->data;
7473:     if (mptmp[cp]) continue;
7474:     if (rmapt[cp] == 2 && hasoffproc) { /* the rows need to be scatter to all processes (might include self) */
7475:       const PetscInt *rmap = rmapa[cp];
7476:       const PetscInt  mr   = mp[cp]->rmap->n;
7477:       const PetscInt  rs   = C->rmap->rstart;
7478:       const PetscInt  re   = C->rmap->rend;
7479:       const PetscInt *ii   = mm->i;
7480:       for (i = 0; i < mr; i++) {
7481:         const PetscInt gr = rmap[i];
7482:         const PetscInt nz = ii[i + 1] - ii[i];
7483:         if (gr < rs || gr >= re) ncoo_o += nz; /* this row is offproc */
7484:         else ncoo_oown += nz;                  /* this row is local */
7485:       }
7486:     } else ncoo_d += mm->nz;
7487:   }

7489:   /*
7490:     ncoo: total number of nonzeros (including those inserted by remote procs) belonging to this proc

7492:     ncoo = ncoo_d + ncoo_oown + ncoo2, which ncoo2 is number of nonzeros inserted to me by other procs.

7494:     off[0] points to a big index array, which is shared by off[1,2,...]. Similarly, for own[0].

7496:     off[p]: points to the segment for matrix mp[p], storing location of nonzeros that mp[p] will insert to others
7497:     own[p]: points to the segment for matrix mp[p], storing location of nonzeros that mp[p] will insert locally
7498:     so, off[p+1]-off[p] is the number of nonzeros that mp[p] will send to others.

7500:     coo_i/j/v[]: [ncoo] row/col/val of nonzeros belonging to this proc.
7501:     Ex. coo_i[]: the beginning part (of size ncoo_d + ncoo_oown) stores i of local nonzeros, and the remaining part stores i of nonzeros I will receive.
7502:   */
7503:   PetscCall(PetscCalloc1(mmdata->cp + 1, &mmdata->off)); /* +1 to make a csr-like data structure */
7504:   PetscCall(PetscCalloc1(mmdata->cp + 1, &mmdata->own));

7506:   /* gather (i,j) of nonzeros inserted by remote procs */
7507:   if (hasoffproc) {
7508:     PetscSF  msf;
7509:     PetscInt ncoo2, *coo_i2, *coo_j2;

7511:     PetscCall(PetscMalloc1(ncoo_o, &mmdata->off[0]));
7512:     PetscCall(PetscMalloc1(ncoo_oown, &mmdata->own[0]));
7513:     PetscCall(PetscMalloc2(ncoo_o, &coo_i, ncoo_o, &coo_j)); /* to collect (i,j) of entries to be sent to others */

7515:     for (cp = 0, ncoo_o = 0; cp < mmdata->cp; cp++) {
7516:       Mat_SeqAIJ *mm     = (Mat_SeqAIJ *)mp[cp]->data;
7517:       PetscInt   *idxoff = mmdata->off[cp];
7518:       PetscInt   *idxown = mmdata->own[cp];
7519:       if (!mptmp[cp] && rmapt[cp] == 2) { /* row map is sparse */
7520:         const PetscInt *rmap = rmapa[cp];
7521:         const PetscInt *cmap = cmapa[cp];
7522:         const PetscInt *ii   = mm->i;
7523:         PetscInt       *coi  = coo_i + ncoo_o;
7524:         PetscInt       *coj  = coo_j + ncoo_o;
7525:         const PetscInt  mr   = mp[cp]->rmap->n;
7526:         const PetscInt  rs   = C->rmap->rstart;
7527:         const PetscInt  re   = C->rmap->rend;
7528:         const PetscInt  cs   = C->cmap->rstart;
7529:         for (i = 0; i < mr; i++) {
7530:           const PetscInt *jj = mm->j + ii[i];
7531:           const PetscInt  gr = rmap[i];
7532:           const PetscInt  nz = ii[i + 1] - ii[i];
7533:           if (gr < rs || gr >= re) { /* this is an offproc row */
7534:             for (j = ii[i]; j < ii[i + 1]; j++) {
7535:               *coi++    = gr;
7536:               *idxoff++ = j;
7537:             }
7538:             if (!cmapt[cp]) { /* already global */
7539:               for (j = 0; j < nz; j++) *coj++ = jj[j];
7540:             } else if (cmapt[cp] == 1) { /* local to global for owned columns of C */
7541:               for (j = 0; j < nz; j++) *coj++ = jj[j] + cs;
7542:             } else { /* offdiag */
7543:               for (j = 0; j < nz; j++) *coj++ = cmap[jj[j]];
7544:             }
7545:             ncoo_o += nz;
7546:           } else { /* this is a local row */
7547:             for (j = ii[i]; j < ii[i + 1]; j++) *idxown++ = j;
7548:           }
7549:         }
7550:       }
7551:       mmdata->off[cp + 1] = idxoff;
7552:       mmdata->own[cp + 1] = idxown;
7553:     }

7555:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)C), &mmdata->sf));
7556:     PetscInt incoo_o;
7557:     PetscCall(PetscIntCast(ncoo_o, &incoo_o));
7558:     PetscCall(PetscSFSetGraphLayout(mmdata->sf, C->rmap, incoo_o /*nleaves*/, NULL /*ilocal*/, PETSC_OWN_POINTER, coo_i));
7559:     PetscCall(PetscSFGetMultiSF(mmdata->sf, &msf));
7560:     PetscCall(PetscSFGetGraph(msf, &ncoo2 /*nroots*/, NULL, NULL, NULL));
7561:     ncoo = ncoo_d + ncoo_oown + ncoo2;
7562:     PetscCall(PetscMalloc2(ncoo, &coo_i2, ncoo, &coo_j2));
7563:     PetscCall(PetscSFGatherBegin(mmdata->sf, MPIU_INT, coo_i, coo_i2 + ncoo_d + ncoo_oown)); /* put (i,j) of remote nonzeros at back */
7564:     PetscCall(PetscSFGatherEnd(mmdata->sf, MPIU_INT, coo_i, coo_i2 + ncoo_d + ncoo_oown));
7565:     PetscCall(PetscSFGatherBegin(mmdata->sf, MPIU_INT, coo_j, coo_j2 + ncoo_d + ncoo_oown));
7566:     PetscCall(PetscSFGatherEnd(mmdata->sf, MPIU_INT, coo_j, coo_j2 + ncoo_d + ncoo_oown));
7567:     PetscCall(PetscFree2(coo_i, coo_j));
7568:     /* allocate MPI send buffer to collect nonzero values to be sent to remote procs */
7569:     PetscCall(PetscSFMalloc(mmdata->sf, mmdata->mtype, ncoo_o * sizeof(PetscScalar), (void **)&mmdata->coo_w));
7570:     coo_i = coo_i2;
7571:     coo_j = coo_j2;
7572:   } else { /* no offproc values insertion */
7573:     ncoo = ncoo_d;
7574:     PetscCall(PetscMalloc2(ncoo, &coo_i, ncoo, &coo_j));

7576:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)C), &mmdata->sf));
7577:     PetscCall(PetscSFSetGraph(mmdata->sf, 0, 0, NULL, PETSC_OWN_POINTER, NULL, PETSC_OWN_POINTER));
7578:     PetscCall(PetscSFSetUp(mmdata->sf));
7579:   }
7580:   mmdata->hasoffproc = hasoffproc;

7582:   /* gather (i,j) of nonzeros inserted locally */
7583:   for (cp = 0, ncoo_d = 0; cp < mmdata->cp; cp++) {
7584:     Mat_SeqAIJ     *mm   = (Mat_SeqAIJ *)mp[cp]->data;
7585:     PetscInt       *coi  = coo_i + ncoo_d;
7586:     PetscInt       *coj  = coo_j + ncoo_d;
7587:     const PetscInt *jj   = mm->j;
7588:     const PetscInt *ii   = mm->i;
7589:     const PetscInt *cmap = cmapa[cp];
7590:     const PetscInt *rmap = rmapa[cp];
7591:     const PetscInt  mr   = mp[cp]->rmap->n;
7592:     const PetscInt  rs   = C->rmap->rstart;
7593:     const PetscInt  re   = C->rmap->rend;
7594:     const PetscInt  cs   = C->cmap->rstart;

7596:     if (mptmp[cp]) continue;
7597:     if (rmapt[cp] == 1) { /* consecutive rows */
7598:       /* fill coo_i */
7599:       for (i = 0; i < mr; i++) {
7600:         const PetscInt gr = i + rs;
7601:         for (j = ii[i]; j < ii[i + 1]; j++) coi[j] = gr;
7602:       }
7603:       /* fill coo_j */
7604:       if (!cmapt[cp]) { /* type-0, already global */
7605:         PetscCall(PetscArraycpy(coj, jj, mm->nz));
7606:       } else if (cmapt[cp] == 1) {                        /* type-1, local to global for consecutive columns of C */
7607:         for (j = 0; j < mm->nz; j++) coj[j] = jj[j] + cs; /* lid + col start */
7608:       } else {                                            /* type-2, local to global for sparse columns */
7609:         for (j = 0; j < mm->nz; j++) coj[j] = cmap[jj[j]];
7610:       }
7611:       ncoo_d += mm->nz;
7612:     } else if (rmapt[cp] == 2) { /* sparse rows */
7613:       for (i = 0; i < mr; i++) {
7614:         const PetscInt *jj = mm->j + ii[i];
7615:         const PetscInt  gr = rmap[i];
7616:         const PetscInt  nz = ii[i + 1] - ii[i];
7617:         if (gr >= rs && gr < re) { /* local rows */
7618:           for (j = ii[i]; j < ii[i + 1]; j++) *coi++ = gr;
7619:           if (!cmapt[cp]) { /* type-0, already global */
7620:             for (j = 0; j < nz; j++) *coj++ = jj[j];
7621:           } else if (cmapt[cp] == 1) { /* local to global for owned columns of C */
7622:             for (j = 0; j < nz; j++) *coj++ = jj[j] + cs;
7623:           } else { /* type-2, local to global for sparse columns */
7624:             for (j = 0; j < nz; j++) *coj++ = cmap[jj[j]];
7625:           }
7626:           ncoo_d += nz;
7627:         }
7628:       }
7629:     }
7630:   }
7631:   if (glob) PetscCall(ISRestoreIndices(glob, &globidx));
7632:   PetscCall(ISDestroy(&glob));
7633:   if (P_oth_l2g) PetscCall(ISLocalToGlobalMappingRestoreIndices(P_oth_l2g, &P_oth_idx));
7634:   PetscCall(ISLocalToGlobalMappingDestroy(&P_oth_l2g));
7635:   /* allocate an array to store all nonzeros (inserted locally or remotely) belonging to this proc */
7636:   PetscCall(PetscSFMalloc(mmdata->sf, mmdata->mtype, ncoo * sizeof(PetscScalar), (void **)&mmdata->coo_v));

7638:   /* set block sizes */
7639:   A = product->A;
7640:   P = product->B;
7641:   switch (ptype) {
7642:   case MATPRODUCT_PtAP:
7643:     PetscCall(MatSetBlockSizes(C, P->cmap->bs, P->cmap->bs));
7644:     break;
7645:   case MATPRODUCT_RARt:
7646:     PetscCall(MatSetBlockSizes(C, P->rmap->bs, P->rmap->bs));
7647:     break;
7648:   case MATPRODUCT_ABC:
7649:     PetscCall(MatSetBlockSizesFromMats(C, A, product->C));
7650:     break;
7651:   case MATPRODUCT_AB:
7652:     PetscCall(MatSetBlockSizesFromMats(C, A, P));
7653:     break;
7654:   case MATPRODUCT_AtB:
7655:     PetscCall(MatSetBlockSizes(C, A->cmap->bs, P->cmap->bs));
7656:     break;
7657:   case MATPRODUCT_ABt:
7658:     PetscCall(MatSetBlockSizes(C, A->rmap->bs, P->rmap->bs));
7659:     break;
7660:   default:
7661:     SETERRQ(PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Not for ProductType %s", MatProductTypes[ptype]);
7662:   }

7664:   /* preallocate with COO data */
7665:   PetscCall(MatSetPreallocationCOO(C, ncoo, coo_i, coo_j));
7666:   PetscCall(PetscFree2(coo_i, coo_j));
7667:   PetscFunctionReturn(PETSC_SUCCESS);
7668: }

7670: PetscErrorCode MatProductSetFromOptions_MPIAIJBACKEND(Mat mat)
7671: {
7672:   Mat_Product *product = mat->product;
7673: #if defined(PETSC_HAVE_DEVICE)
7674:   PetscBool match  = PETSC_FALSE;
7675:   PetscBool usecpu = PETSC_FALSE;
7676: #else
7677:   PetscBool match = PETSC_TRUE;
7678: #endif

7680:   PetscFunctionBegin;
7681:   MatCheckProduct(mat, 1);
7682: #if defined(PETSC_HAVE_DEVICE)
7683:   if (!product->A->boundtocpu && !product->B->boundtocpu) PetscCall(PetscObjectTypeCompare((PetscObject)product->B, ((PetscObject)product->A)->type_name, &match));
7684:   if (match) { /* we can always fallback to the CPU if requested */
7685:     switch (product->type) {
7686:     case MATPRODUCT_AB:
7687:       if (product->api_user) {
7688:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatMatMult", "Mat");
7689:         PetscCall(PetscOptionsBool("-matmatmult_backend_cpu", "Use CPU code", "MatMatMult", usecpu, &usecpu, NULL));
7690:         PetscOptionsEnd();
7691:       } else {
7692:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatProduct_AB", "Mat");
7693:         PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_cpu", "Use CPU code", "MatMatMult", usecpu, &usecpu, NULL));
7694:         PetscOptionsEnd();
7695:       }
7696:       break;
7697:     case MATPRODUCT_AtB:
7698:       if (product->api_user) {
7699:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatTransposeMatMult", "Mat");
7700:         PetscCall(PetscOptionsBool("-mattransposematmult_backend_cpu", "Use CPU code", "MatTransposeMatMult", usecpu, &usecpu, NULL));
7701:         PetscOptionsEnd();
7702:       } else {
7703:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatProduct_AtB", "Mat");
7704:         PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_cpu", "Use CPU code", "MatTransposeMatMult", usecpu, &usecpu, NULL));
7705:         PetscOptionsEnd();
7706:       }
7707:       break;
7708:     case MATPRODUCT_PtAP:
7709:       if (product->api_user) {
7710:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatPtAP", "Mat");
7711:         PetscCall(PetscOptionsBool("-matptap_backend_cpu", "Use CPU code", "MatPtAP", usecpu, &usecpu, NULL));
7712:         PetscOptionsEnd();
7713:       } else {
7714:         PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "MatProduct_PtAP", "Mat");
7715:         PetscCall(PetscOptionsBool("-mat_product_algorithm_backend_cpu", "Use CPU code", "MatPtAP", usecpu, &usecpu, NULL));
7716:         PetscOptionsEnd();
7717:       }
7718:       break;
7719:     default:
7720:       break;
7721:     }
7722:     match = (PetscBool)!usecpu;
7723:   }
7724: #endif
7725:   if (match) {
7726:     switch (product->type) {
7727:     case MATPRODUCT_AB:
7728:     case MATPRODUCT_AtB:
7729:     case MATPRODUCT_PtAP:
7730:       mat->ops->productsymbolic = MatProductSymbolic_MPIAIJBACKEND;
7731:       break;
7732:     default:
7733:       break;
7734:     }
7735:   }
7736:   /* fallback to MPIAIJ ops */
7737:   if (!mat->ops->productsymbolic) PetscCall(MatProductSetFromOptions_MPIAIJ(mat));
7738:   PetscFunctionReturn(PETSC_SUCCESS);
7739: }

7741: /*
7742:    Produces a set of block column indices of the matrix row, one for each block represented in the original row

7744:    n - the number of block indices in cc[]
7745:    cc - the block indices (must be large enough to contain the indices)
7746: */
7747: static inline PetscErrorCode MatCollapseRow(Mat Amat, PetscInt row, PetscInt bs, PetscInt *n, PetscInt *cc)
7748: {
7749:   PetscInt        cnt = -1, nidx, j;
7750:   const PetscInt *idx;

7752:   PetscFunctionBegin;
7753:   PetscCall(MatGetRow(Amat, row, &nidx, &idx, NULL));
7754:   if (nidx) {
7755:     cnt     = 0;
7756:     cc[cnt] = idx[0] / bs;
7757:     for (j = 1; j < nidx; j++) {
7758:       if (cc[cnt] < idx[j] / bs) cc[++cnt] = idx[j] / bs;
7759:     }
7760:   }
7761:   PetscCall(MatRestoreRow(Amat, row, &nidx, &idx, NULL));
7762:   *n = cnt + 1;
7763:   PetscFunctionReturn(PETSC_SUCCESS);
7764: }

7766: /*
7767:     Produces a set of block column indices of the matrix block row, one for each block represented in the original set of rows

7769:     ncollapsed - the number of block indices
7770:     collapsed - the block indices (must be large enough to contain the indices)
7771: */
7772: static inline PetscErrorCode MatCollapseRows(Mat Amat, PetscInt start, PetscInt bs, PetscInt *w0, PetscInt *w1, PetscInt *w2, PetscInt *ncollapsed, PetscInt **collapsed)
7773: {
7774:   PetscInt i, nprev, *cprev = w0, ncur = 0, *ccur = w1, *merged = w2, *cprevtmp;

7776:   PetscFunctionBegin;
7777:   PetscCall(MatCollapseRow(Amat, start, bs, &nprev, cprev));
7778:   for (i = start + 1; i < start + bs; i++) {
7779:     PetscCall(MatCollapseRow(Amat, i, bs, &ncur, ccur));
7780:     PetscCall(PetscMergeIntArray(nprev, cprev, ncur, ccur, &nprev, &merged));
7781:     cprevtmp = cprev;
7782:     cprev    = merged;
7783:     merged   = cprevtmp;
7784:   }
7785:   *ncollapsed = nprev;
7786:   if (collapsed) *collapsed = cprev;
7787:   PetscFunctionReturn(PETSC_SUCCESS);
7788: }

7790: /*
7791:  MatCreateGraph_Simple_AIJ - create simple scalar matrix (graph) from potentially blocked matrix

7793:  Input Parameter:
7794:  . Amat - matrix
7795:  - symmetrize - make the result symmetric
7796:  + scale - scale with diagonal

7798:  Output Parameter:
7799:  . a_Gmat - output scalar graph >= 0

7801: */
7802: PETSC_INTERN PetscErrorCode MatCreateGraph_Simple_AIJ(Mat Amat, PetscBool symmetrize, PetscBool scale, PetscReal filter, PetscInt index_size, PetscInt index[], Mat *a_Gmat)
7803: {
7804:   PetscInt  Istart, Iend, Ii, jj, kk, ncols, nloc, NN, MM, bs;
7805:   MPI_Comm  comm;
7806:   Mat       Gmat;
7807:   PetscBool ismpiaij, isseqaij;
7808:   Mat       a, b, c;
7809:   MatType   jtype;

7811:   PetscFunctionBegin;
7812:   PetscCall(PetscObjectGetComm((PetscObject)Amat, &comm));
7813:   PetscCall(MatGetOwnershipRange(Amat, &Istart, &Iend));
7814:   PetscCall(MatGetSize(Amat, &MM, &NN));
7815:   PetscCall(MatGetBlockSize(Amat, &bs));
7816:   nloc = (Iend - Istart) / bs;

7818:   PetscCall(PetscObjectBaseTypeCompare((PetscObject)Amat, MATSEQAIJ, &isseqaij));
7819:   PetscCall(PetscObjectBaseTypeCompare((PetscObject)Amat, MATMPIAIJ, &ismpiaij));
7820:   PetscCheck(isseqaij || ismpiaij, comm, PETSC_ERR_USER, "Require (MPI)AIJ matrix type");

7822:   /* TODO GPU: these calls are potentially expensive if matrices are large and we want to use the GPU */
7823:   /* A solution consists in providing a new API, MatAIJGetCollapsedAIJ, and each class can provide a fast
7824:      implementation */
7825:   if (bs > 1) {
7826:     PetscCall(MatGetType(Amat, &jtype));
7827:     PetscCall(MatCreate(comm, &Gmat));
7828:     PetscCall(MatSetType(Gmat, jtype));
7829:     PetscCall(MatSetSizes(Gmat, nloc, nloc, PETSC_DETERMINE, PETSC_DETERMINE));
7830:     PetscCall(MatSetBlockSizes(Gmat, 1, 1));
7831:     if (isseqaij || ((Mat_MPIAIJ *)Amat->data)->garray) {
7832:       PetscInt  *d_nnz, *o_nnz;
7833:       MatScalar *aa, val, *AA;
7834:       PetscInt  *aj, *ai, *AJ, nc, nmax = 0;

7836:       if (isseqaij) {
7837:         a = Amat;
7838:         b = NULL;
7839:       } else {
7840:         Mat_MPIAIJ *d = (Mat_MPIAIJ *)Amat->data;
7841:         a             = d->A;
7842:         b             = d->B;
7843:       }
7844:       PetscCall(PetscInfo(Amat, "New bs>1 Graph. nloc=%" PetscInt_FMT "\n", nloc));
7845:       PetscCall(PetscMalloc2(nloc, &d_nnz, (isseqaij ? 0 : nloc), &o_nnz));
7846:       for (c = a, kk = 0; c && kk < 2; c = b, kk++) {
7847:         PetscInt       *nnz = (c == a) ? d_nnz : o_nnz;
7848:         const PetscInt *cols1, *cols2;

7850:         for (PetscInt brow = 0, nc1, nc2, ok = 1; brow < nloc * bs; brow += bs) { // block rows
7851:           PetscCall(MatGetRow(c, brow, &nc2, &cols2, NULL));
7852:           nnz[brow / bs] = nc2 / bs;
7853:           if (nc2 % bs) ok = 0;
7854:           if (nnz[brow / bs] > nmax) nmax = nnz[brow / bs];
7855:           for (PetscInt ii = 1; ii < bs; ii++) { // check for non-dense blocks
7856:             PetscCall(MatGetRow(c, brow + ii, &nc1, &cols1, NULL));
7857:             if (nc1 != nc2) ok = 0;
7858:             else {
7859:               for (PetscInt jj = 0; jj < nc1 && ok == 1; jj++) {
7860:                 if (cols1[jj] != cols2[jj]) ok = 0;
7861:                 if (cols1[jj] % bs != jj % bs) ok = 0;
7862:               }
7863:             }
7864:             PetscCall(MatRestoreRow(c, brow + ii, &nc1, &cols1, NULL));
7865:           }
7866:           PetscCall(MatRestoreRow(c, brow, &nc2, &cols2, NULL));
7867:           if (!ok) {
7868:             PetscCall(PetscFree2(d_nnz, o_nnz));
7869:             PetscCall(PetscInfo(Amat, "Found sparse blocks - revert to slow method\n"));
7870:             goto old_bs;
7871:           }
7872:         }
7873:       }
7874:       PetscCall(MatSeqAIJSetPreallocation(Gmat, 0, d_nnz));
7875:       PetscCall(MatMPIAIJSetPreallocation(Gmat, 0, d_nnz, 0, o_nnz));
7876:       PetscCall(PetscFree2(d_nnz, o_nnz));
7877:       PetscCall(PetscMalloc2(nmax, &AA, nmax, &AJ));
7878:       // diag
7879:       for (PetscInt brow = 0, n, grow; brow < nloc * bs; brow += bs) { // block rows
7880:         Mat_SeqAIJ *aseq = (Mat_SeqAIJ *)a->data;

7882:         ai = aseq->i;
7883:         n  = ai[brow + 1] - ai[brow];
7884:         aj = aseq->j + ai[brow];
7885:         for (PetscInt k = 0; k < n; k += bs) {   // block columns
7886:           AJ[k / bs] = aj[k] / bs + Istart / bs; // diag starts at (Istart,Istart)
7887:           val        = 0;
7888:           if (index_size == 0) {
7889:             for (PetscInt ii = 0; ii < bs; ii++) { // rows in block
7890:               aa = aseq->a + ai[brow + ii] + k;
7891:               for (PetscInt jj = 0; jj < bs; jj++) {    // columns in block
7892:                 val += PetscAbs(PetscRealPart(aa[jj])); // a sort of norm
7893:               }
7894:             }
7895:           } else {                                            // use (index,index) value if provided
7896:             for (PetscInt iii = 0; iii < index_size; iii++) { // rows in block
7897:               PetscInt ii = index[iii];
7898:               aa          = aseq->a + ai[brow + ii] + k;
7899:               for (PetscInt jjj = 0; jjj < index_size; jjj++) { // columns in block
7900:                 PetscInt jj = index[jjj];
7901:                 val += PetscAbs(PetscRealPart(aa[jj]));
7902:               }
7903:             }
7904:           }
7905:           PetscAssert(k / bs < nmax, comm, PETSC_ERR_USER, "k / bs (%" PetscInt_FMT ") >= nmax (%" PetscInt_FMT ")", k / bs, nmax);
7906:           AA[k / bs] = val;
7907:         }
7908:         grow = Istart / bs + brow / bs;
7909:         PetscCall(MatSetValues(Gmat, 1, &grow, n / bs, AJ, AA, ADD_VALUES));
7910:       }
7911:       // off-diag
7912:       if (ismpiaij) {
7913:         Mat_MPIAIJ        *aij = (Mat_MPIAIJ *)Amat->data;
7914:         const PetscScalar *vals;
7915:         const PetscInt    *cols, *garray = aij->garray;

7917:         PetscCheck(garray, PETSC_COMM_SELF, PETSC_ERR_USER, "No garray ?");
7918:         for (PetscInt brow = 0, grow; brow < nloc * bs; brow += bs) { // block rows
7919:           PetscCall(MatGetRow(b, brow, &ncols, &cols, NULL));
7920:           for (PetscInt k = 0, cidx = 0; k < ncols; k += bs, cidx++) {
7921:             PetscAssert(k / bs < nmax, comm, PETSC_ERR_USER, "k / bs >= nmax");
7922:             AA[k / bs] = 0;
7923:             AJ[cidx]   = garray[cols[k]] / bs;
7924:           }
7925:           nc = ncols / bs;
7926:           PetscCall(MatRestoreRow(b, brow, &ncols, &cols, NULL));
7927:           if (index_size == 0) {
7928:             for (PetscInt ii = 0; ii < bs; ii++) { // rows in block
7929:               PetscCall(MatGetRow(b, brow + ii, &ncols, &cols, &vals));
7930:               for (PetscInt k = 0; k < ncols; k += bs) {
7931:                 for (PetscInt jj = 0; jj < bs; jj++) { // cols in block
7932:                   PetscAssert(k / bs < nmax, comm, PETSC_ERR_USER, "k / bs (%" PetscInt_FMT ") >= nmax (%" PetscInt_FMT ")", k / bs, nmax);
7933:                   AA[k / bs] += PetscAbs(PetscRealPart(vals[k + jj]));
7934:                 }
7935:               }
7936:               PetscCall(MatRestoreRow(b, brow + ii, &ncols, &cols, &vals));
7937:             }
7938:           } else {                                            // use (index,index) value if provided
7939:             for (PetscInt iii = 0; iii < index_size; iii++) { // rows in block
7940:               PetscInt ii = index[iii];
7941:               PetscCall(MatGetRow(b, brow + ii, &ncols, &cols, &vals));
7942:               for (PetscInt k = 0; k < ncols; k += bs) {
7943:                 for (PetscInt jjj = 0; jjj < index_size; jjj++) { // cols in block
7944:                   PetscInt jj = index[jjj];
7945:                   AA[k / bs] += PetscAbs(PetscRealPart(vals[k + jj]));
7946:                 }
7947:               }
7948:               PetscCall(MatRestoreRow(b, brow + ii, &ncols, &cols, &vals));
7949:             }
7950:           }
7951:           grow = Istart / bs + brow / bs;
7952:           PetscCall(MatSetValues(Gmat, 1, &grow, nc, AJ, AA, ADD_VALUES));
7953:         }
7954:       }
7955:       PetscCall(MatAssemblyBegin(Gmat, MAT_FINAL_ASSEMBLY));
7956:       PetscCall(MatAssemblyEnd(Gmat, MAT_FINAL_ASSEMBLY));
7957:       PetscCall(PetscFree2(AA, AJ));
7958:     } else {
7959:       const PetscScalar *vals;
7960:       const PetscInt    *idx;
7961:       PetscInt          *d_nnz, *o_nnz, *w0, *w1, *w2;
7962:     old_bs:
7963:       /*
7964:        Determine the preallocation needed for the scalar matrix derived from the vector matrix.
7965:        */
7966:       PetscCall(PetscInfo(Amat, "OLD bs>1 CreateGraph\n"));
7967:       PetscCall(PetscMalloc2(nloc, &d_nnz, (isseqaij ? 0 : nloc), &o_nnz));
7968:       if (isseqaij) {
7969:         PetscInt max_d_nnz;

7971:         /*
7972:          Determine exact preallocation count for (sequential) scalar matrix
7973:          */
7974:         PetscCall(MatSeqAIJGetMaxRowNonzeros(Amat, &max_d_nnz));
7975:         max_d_nnz = PetscMin(nloc, bs * max_d_nnz);
7976:         PetscCall(PetscMalloc3(max_d_nnz, &w0, max_d_nnz, &w1, max_d_nnz, &w2));
7977:         for (Ii = 0, jj = 0; Ii < Iend; Ii += bs, jj++) PetscCall(MatCollapseRows(Amat, Ii, bs, w0, w1, w2, &d_nnz[jj], NULL));
7978:         PetscCall(PetscFree3(w0, w1, w2));
7979:       } else if (ismpiaij) {
7980:         Mat             Daij, Oaij;
7981:         const PetscInt *garray;
7982:         PetscInt        max_d_nnz;

7984:         PetscCall(MatMPIAIJGetSeqAIJ(Amat, &Daij, &Oaij, &garray));
7985:         /*
7986:          Determine exact preallocation count for diagonal block portion of scalar matrix
7987:          */
7988:         PetscCall(MatSeqAIJGetMaxRowNonzeros(Daij, &max_d_nnz));
7989:         max_d_nnz = PetscMin(nloc, bs * max_d_nnz);
7990:         PetscCall(PetscMalloc3(max_d_nnz, &w0, max_d_nnz, &w1, max_d_nnz, &w2));
7991:         for (Ii = 0, jj = 0; Ii < Iend - Istart; Ii += bs, jj++) PetscCall(MatCollapseRows(Daij, Ii, bs, w0, w1, w2, &d_nnz[jj], NULL));
7992:         PetscCall(PetscFree3(w0, w1, w2));
7993:         /*
7994:          Over estimate (usually grossly over), preallocation count for off-diagonal portion of scalar matrix
7995:          */
7996:         for (Ii = 0, jj = 0; Ii < Iend - Istart; Ii += bs, jj++) {
7997:           o_nnz[jj] = 0;
7998:           for (kk = 0; kk < bs; kk++) { /* rows that get collapsed to a single row */
7999:             PetscCall(MatGetRow(Oaij, Ii + kk, &ncols, NULL, NULL));
8000:             o_nnz[jj] += ncols;
8001:             PetscCall(MatRestoreRow(Oaij, Ii + kk, &ncols, NULL, NULL));
8002:           }
8003:           if (o_nnz[jj] > (NN / bs - nloc)) o_nnz[jj] = NN / bs - nloc;
8004:         }
8005:       } else SETERRQ(comm, PETSC_ERR_USER, "Require AIJ matrix type");
8006:       /* get scalar copy (norms) of matrix */
8007:       PetscCall(MatSeqAIJSetPreallocation(Gmat, 0, d_nnz));
8008:       PetscCall(MatMPIAIJSetPreallocation(Gmat, 0, d_nnz, 0, o_nnz));
8009:       PetscCall(PetscFree2(d_nnz, o_nnz));
8010:       for (Ii = Istart; Ii < Iend; Ii++) {
8011:         PetscInt dest_row = Ii / bs;

8013:         PetscCall(MatGetRow(Amat, Ii, &ncols, &idx, &vals));
8014:         for (jj = 0; jj < ncols; jj++) {
8015:           PetscInt    dest_col = idx[jj] / bs;
8016:           PetscScalar sv       = PetscAbs(PetscRealPart(vals[jj]));

8018:           PetscCall(MatSetValues(Gmat, 1, &dest_row, 1, &dest_col, &sv, ADD_VALUES));
8019:         }
8020:         PetscCall(MatRestoreRow(Amat, Ii, &ncols, &idx, &vals));
8021:       }
8022:       PetscCall(MatAssemblyBegin(Gmat, MAT_FINAL_ASSEMBLY));
8023:       PetscCall(MatAssemblyEnd(Gmat, MAT_FINAL_ASSEMBLY));
8024:     }
8025:   } else {
8026:     if (symmetrize || filter >= 0 || scale) PetscCall(MatDuplicate(Amat, MAT_COPY_VALUES, &Gmat));
8027:     else {
8028:       Gmat = Amat;
8029:       PetscCall(PetscObjectReference((PetscObject)Gmat));
8030:     }
8031:     if (isseqaij) {
8032:       a = Gmat;
8033:       b = NULL;
8034:     } else {
8035:       Mat_MPIAIJ *d = (Mat_MPIAIJ *)Gmat->data;
8036:       a             = d->A;
8037:       b             = d->B;
8038:     }
8039:     if (filter >= 0 || scale) {
8040:       /* take absolute value of each entry */
8041:       for (c = a, kk = 0; c && kk < 2; c = b, kk++) {
8042:         MatInfo      info;
8043:         PetscScalar *avals;

8045:         PetscCall(MatGetInfo(c, MAT_LOCAL, &info));
8046:         PetscCall(MatSeqAIJGetArray(c, &avals));
8047:         for (int jj = 0; jj < info.nz_used; jj++) avals[jj] = PetscAbsScalar(avals[jj]);
8048:         PetscCall(MatSeqAIJRestoreArray(c, &avals));
8049:       }
8050:     }
8051:   }
8052:   if (symmetrize) {
8053:     PetscBool isset, issym;

8055:     PetscCall(MatIsSymmetricKnown(Amat, &isset, &issym));
8056:     if (!isset || !issym) {
8057:       Mat matTrans;

8059:       PetscCall(MatTranspose(Gmat, MAT_INITIAL_MATRIX, &matTrans));
8060:       PetscCall(MatAXPY(Gmat, 1.0, matTrans, Gmat->structurally_symmetric == PETSC_BOOL3_TRUE ? SAME_NONZERO_PATTERN : DIFFERENT_NONZERO_PATTERN));
8061:       PetscCall(MatDestroy(&matTrans));
8062:     }
8063:     PetscCall(MatSetOption(Gmat, MAT_SYMMETRIC, PETSC_TRUE));
8064:   } else if (Amat != Gmat) PetscCall(MatPropagateSymmetryOptions(Amat, Gmat));
8065:   if (scale) {
8066:     /* scale c for all diagonal values = 1 or -1 */
8067:     Vec diag;

8069:     PetscCall(MatCreateVecs(Gmat, &diag, NULL));
8070:     PetscCall(MatGetDiagonal(Gmat, diag));
8071:     PetscCall(VecReciprocal(diag));
8072:     PetscCall(VecSqrtAbs(diag));
8073:     PetscCall(MatDiagonalScale(Gmat, diag, diag));
8074:     PetscCall(VecDestroy(&diag));
8075:   }
8076:   PetscCall(MatViewFromOptions(Gmat, NULL, "-mat_graph_view"));
8077:   if (filter >= 0) {
8078:     PetscCall(MatFilter(Gmat, filter, PETSC_TRUE, PETSC_TRUE));
8079:     PetscCall(MatViewFromOptions(Gmat, NULL, "-mat_filter_graph_view"));
8080:   }
8081:   *a_Gmat = Gmat;
8082:   PetscFunctionReturn(PETSC_SUCCESS);
8083: }

8085: /*
8086:     Special version for direct calls from Fortran
8087: */

8089: /* Change these macros so can be used in void function */
8090: /* Identical to PetscCallVoid, except it assigns to *_ierr */
8091: #undef PetscCall
8092: #define PetscCall(...) \
8093:   do { \
8094:     PetscErrorCode ierr_msv_mpiaij = __VA_ARGS__; \
8095:     if (PetscUnlikely(ierr_msv_mpiaij)) { \
8096:       *_ierr = PetscError(PETSC_COMM_SELF, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr_msv_mpiaij, PETSC_ERROR_REPEAT, " "); \
8097:       return; \
8098:     } \
8099:   } while (0)

8101: #undef SETERRQ
8102: #define SETERRQ(comm, ierr, ...) \
8103:   do { \
8104:     *_ierr = PetscError(comm, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr, PETSC_ERROR_INITIAL, __VA_ARGS__); \
8105:     return; \
8106:   } while (0)

8108: #if defined(PETSC_HAVE_FORTRAN_CAPS)
8109:   #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
8110: #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
8111:   #define matsetvaluesmpiaij_ matsetvaluesmpiaij
8112: #else
8113: #endif
8114: PETSC_EXTERN void matsetvaluesmpiaij_(Mat *mmat, PetscInt *mm, const PetscInt im[], PetscInt *mn, const PetscInt in[], const PetscScalar v[], InsertMode *maddv, PetscErrorCode *_ierr)
8115: {
8116:   Mat         mat = *mmat;
8117:   PetscInt    m = *mm, n = *mn;
8118:   InsertMode  addv = *maddv;
8119:   Mat_MPIAIJ *aij  = (Mat_MPIAIJ *)mat->data;
8120:   PetscScalar value;

8122:   MatCheckPreallocated(mat, 1);
8123:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
8124:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
8125:   {
8126:     PetscInt  i, j, rstart = mat->rmap->rstart, rend = mat->rmap->rend;
8127:     PetscInt  cstart = mat->cmap->rstart, cend = mat->cmap->rend, row, col;
8128:     PetscBool roworiented = aij->roworiented;

8130:     /* Some Variables required in the macro */
8131:     Mat         A     = aij->A;
8132:     Mat_SeqAIJ *a     = (Mat_SeqAIJ *)A->data;
8133:     PetscInt   *aimax = a->imax, *ai = a->i, *ailen = a->ilen, *aj = a->j;
8134:     MatScalar  *aa;
8135:     PetscBool   ignorezeroentries = ((a->ignorezeroentries && (addv == ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
8136:     Mat         B                 = aij->B;
8137:     Mat_SeqAIJ *b                 = (Mat_SeqAIJ *)B->data;
8138:     PetscInt   *bimax = b->imax, *bi = b->i, *bilen = b->ilen, *bj = b->j, bm = aij->B->rmap->n, am = aij->A->rmap->n;
8139:     MatScalar  *ba;
8140:     /* This variable below is only for the PETSC_HAVE_VIENNACL or PETSC_HAVE_CUDA cases, but we define it in all cases because we
8141:      * cannot use "#if defined" inside a macro. */
8142:     PETSC_UNUSED PetscBool inserted = PETSC_FALSE;

8144:     PetscInt  *rp1, *rp2, ii, nrow1, nrow2, _i, rmax1, rmax2, N, low1, high1, low2, high2, t, lastcol1, lastcol2;
8145:     PetscInt   nonew = a->nonew;
8146:     MatScalar *ap1, *ap2;

8148:     PetscFunctionBegin;
8149:     PetscCall(MatSeqAIJGetArray(A, &aa));
8150:     PetscCall(MatSeqAIJGetArray(B, &ba));
8151:     for (i = 0; i < m; i++) {
8152:       if (im[i] < 0) continue;
8153:       PetscCheck(im[i] < mat->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, im[i], mat->rmap->N - 1);
8154:       if (im[i] >= rstart && im[i] < rend) {
8155:         row      = im[i] - rstart;
8156:         lastcol1 = -1;
8157:         rp1      = aj + ai[row];
8158:         ap1      = aa + ai[row];
8159:         rmax1    = aimax[row];
8160:         nrow1    = ailen[row];
8161:         low1     = 0;
8162:         high1    = nrow1;
8163:         lastcol2 = -1;
8164:         rp2      = bj + bi[row];
8165:         ap2      = ba + bi[row];
8166:         rmax2    = bimax[row];
8167:         nrow2    = bilen[row];
8168:         low2     = 0;
8169:         high2    = nrow2;

8171:         for (j = 0; j < n; j++) {
8172:           if (roworiented) value = v[i * n + j];
8173:           else value = v[i + j * m];
8174:           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES) && im[i] != in[j]) continue;
8175:           if (in[j] >= cstart && in[j] < cend) {
8176:             col = in[j] - cstart;
8177:             MatSetValues_SeqAIJ_A_Private(row, col, value, addv, im[i], in[j]);
8178:           } else if (in[j] < 0) continue;
8179:           else if (PetscUnlikelyDebug(in[j] >= mat->cmap->N)) {
8180:             SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[j], mat->cmap->N - 1);
8181:           } else {
8182:             if (mat->was_assembled) {
8183:               if (!aij->colmap) PetscCall(MatCreateColmap_MPIAIJ_Private(mat));
8184: #if defined(PETSC_USE_CTABLE)
8185:               PetscCall(PetscHMapIGetWithDefault(aij->colmap, in[j] + 1, 0, &col));
8186:               col--;
8187: #else
8188:               col = aij->colmap[in[j]] - 1;
8189: #endif
8190:               if (col < 0 && !((Mat_SeqAIJ *)aij->A->data)->nonew) {
8191:                 PetscCall(MatDisAssemble_MPIAIJ(mat, PETSC_FALSE));
8192:                 col = in[j];
8193:                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
8194:                 B        = aij->B;
8195:                 b        = (Mat_SeqAIJ *)B->data;
8196:                 bimax    = b->imax;
8197:                 bi       = b->i;
8198:                 bilen    = b->ilen;
8199:                 bj       = b->j;
8200:                 rp2      = bj + bi[row];
8201:                 ap2      = ba + bi[row];
8202:                 rmax2    = bimax[row];
8203:                 nrow2    = bilen[row];
8204:                 low2     = 0;
8205:                 high2    = nrow2;
8206:                 bm       = aij->B->rmap->n;
8207:                 ba       = b->a;
8208:                 inserted = PETSC_FALSE;
8209:               }
8210:             } else col = in[j];
8211:             MatSetValues_SeqAIJ_B_Private(row, col, value, addv, im[i], in[j]);
8212:           }
8213:         }
8214:       } else if (!aij->donotstash) {
8215:         if (roworiented) {
8216:           PetscCall(MatStashValuesRow_Private(&mat->stash, im[i], n, in, v + i * n, (PetscBool)(ignorezeroentries && (addv == ADD_VALUES))));
8217:         } else {
8218:           PetscCall(MatStashValuesCol_Private(&mat->stash, im[i], n, in, v + i, m, (PetscBool)(ignorezeroentries && (addv == ADD_VALUES))));
8219:         }
8220:       }
8221:     }
8222:     PetscCall(MatSeqAIJRestoreArray(A, &aa));
8223:     PetscCall(MatSeqAIJRestoreArray(B, &ba));
8224:   }
8225:   PetscFunctionReturnVoid();
8226: }

8228: /* Undefining these here since they were redefined from their original definition above! No
8229:  * other PETSc functions should be defined past this point, as it is impossible to recover the
8230:  * original definitions */
8231: #undef PetscCall
8232: #undef SETERRQ