Actual source code: mhyp.c

  1: /*
  2:     Creates hypre ijmatrix from PETSc matrix
  3: */
  4: #include <petscsys.h>
  5: #include <petsc/private/petschypre.h>
  6: #include <petsc/private/matimpl.h>
  7: #include <petscdmda.h>
  8: #include <../src/dm/impls/da/hypre/mhyp.h>

 10: /*MC
 11:    MATHYPRESTRUCT - MATHYPRESTRUCT = "hyprestruct" - A matrix type to be used for parallel sparse matrices
 12:           based on the hypre HYPRE_StructMatrix.

 14:    Level: intermediate

 16:    Notes:
 17:     Unlike the more general support for blocks in hypre this allows only one block per process and requires the block
 18:           be defined by a `DMDA`.

 20:           The matrix needs a `DMDA` associated with it by either a call to `MatSetDM()` or if the matrix is obtained from `DMCreateMatrix()`

 22: .seealso: `MatCreate()`, `PCPFMG`, `MatSetDM()`, `DMCreateMatrix()`
 23: M*/

 25: static PetscErrorCode MatSetValuesLocal_HYPREStruct_3d(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
 26: {
 27:   HYPRE_Int        index[3], entries[9];
 28:   PetscInt         i, j, stencil, row;
 29:   HYPRE_Complex   *values = (HYPRE_Complex *)y;
 30:   Mat_HYPREStruct *ex     = (Mat_HYPREStruct *)mat->data;

 32:   PetscFunctionBegin;
 33:   PetscCheck(ncol <= 9, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "ncol %" PetscInt_FMT " > 9 too large", ncol);
 34:   for (i = 0; i < nrow; i++) {
 35:     for (j = 0; j < ncol; j++) {
 36:       stencil = icol[j] - irow[i];
 37:       if (!stencil) {
 38:         entries[j] = 3;
 39:       } else if (stencil == -1) {
 40:         entries[j] = 2;
 41:       } else if (stencil == 1) {
 42:         entries[j] = 4;
 43:       } else if (stencil == -ex->gnx) {
 44:         entries[j] = 1;
 45:       } else if (stencil == ex->gnx) {
 46:         entries[j] = 5;
 47:       } else if (stencil == -ex->gnxgny) {
 48:         entries[j] = 0;
 49:       } else if (stencil == ex->gnxgny) {
 50:         entries[j] = 6;
 51:       } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Local row %" PetscInt_FMT " local column %" PetscInt_FMT " have bad stencil %" PetscInt_FMT, irow[i], icol[j], stencil);
 52:     }
 53:     row      = ex->gindices[irow[i]] - ex->rstart;
 54:     index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
 55:     index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
 56:     index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));
 57:     if (addv == ADD_VALUES) PetscCallHYPRE(HYPRE_StructMatrixAddToValues(ex->hmat, index, (HYPRE_Int)ncol, entries, values));
 58:     else PetscCallHYPRE(HYPRE_StructMatrixSetValues(ex->hmat, index, (HYPRE_Int)ncol, entries, values));
 59:     values += ncol;
 60:   }
 61:   PetscFunctionReturn(PETSC_SUCCESS);
 62: }

 64: static PetscErrorCode MatZeroRowsLocal_HYPREStruct_3d(Mat mat, PetscInt nrow, const PetscInt irow[], PetscScalar d, Vec x, Vec b)
 65: {
 66:   HYPRE_Int        index[3], entries[7] = {0, 1, 2, 3, 4, 5, 6};
 67:   PetscInt         row, i;
 68:   HYPRE_Complex    values[7];
 69:   Mat_HYPREStruct *ex = (Mat_HYPREStruct *)mat->data;

 71:   PetscFunctionBegin;
 72:   PetscCheck(!x || !b, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "No support");
 73:   PetscCall(PetscArrayzero(values, 7));
 74:   PetscCall(PetscHYPREScalarCast(d, &values[3]));
 75:   for (i = 0; i < nrow; i++) {
 76:     row      = ex->gindices[irow[i]] - ex->rstart;
 77:     index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
 78:     index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
 79:     index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));
 80:     PetscCallHYPRE(HYPRE_StructMatrixSetValues(ex->hmat, index, 7, entries, values));
 81:   }
 82:   PetscCallHYPRE(HYPRE_StructMatrixAssemble(ex->hmat));
 83:   PetscFunctionReturn(PETSC_SUCCESS);
 84: }

 86: static PetscErrorCode MatZeroEntries_HYPREStruct_3d(Mat mat)
 87: {
 88:   HYPRE_Int        indices[7] = {0, 1, 2, 3, 4, 5, 6};
 89:   Mat_HYPREStruct *ex         = (Mat_HYPREStruct *)mat->data;

 91:   PetscFunctionBegin;
 92:   /* hypre has no public interface to do this */
 93:   PetscCallHYPRE(hypre_StructMatrixClearBoxValues(ex->hmat, &ex->hbox, 7, indices, 0, 1));
 94:   PetscCallHYPRE(HYPRE_StructMatrixAssemble(ex->hmat));
 95:   PetscFunctionReturn(PETSC_SUCCESS);
 96: }

 98: static PetscErrorCode MatSetUp_HYPREStruct(Mat mat)
 99: {
100:   Mat_HYPREStruct       *ex = (Mat_HYPREStruct *)mat->data;
101:   HYPRE_Int              sw[6];
102:   HYPRE_Int              hlower[3], hupper[3], period[3] = {0, 0, 0};
103:   PetscInt               dim, dof, psw, Nx, Ny, Nz, nx, ny, nz, ilower[3], iupper[3], ssize, i;
104:   DMBoundaryType         px, py, pz;
105:   DMDAStencilType        st;
106:   ISLocalToGlobalMapping ltog;
107:   DM                     da;

109:   PetscFunctionBegin;
110:   PetscCall(MatGetDM(mat, (DM *)&da));
111:   ex->da = da;
112:   PetscCall(PetscObjectReference((PetscObject)da));

114:   PetscCall(DMDAGetInfo(ex->da, &dim, &Nx, &Ny, &Nz, 0, 0, 0, &dof, &psw, &px, &py, &pz, &st));
115:   PetscCall(DMDAGetCorners(ex->da, &ilower[0], &ilower[1], &ilower[2], &iupper[0], &iupper[1], &iupper[2]));

117:   /* when HYPRE_MIXEDINT is defined, sizeof(HYPRE_Int) == 32 */
118:   iupper[0] += ilower[0] - 1;
119:   iupper[1] += ilower[1] - 1;
120:   iupper[2] += ilower[2] - 1;
121:   hlower[0] = (HYPRE_Int)ilower[0];
122:   hlower[1] = (HYPRE_Int)ilower[1];
123:   hlower[2] = (HYPRE_Int)ilower[2];
124:   hupper[0] = (HYPRE_Int)iupper[0];
125:   hupper[1] = (HYPRE_Int)iupper[1];
126:   hupper[2] = (HYPRE_Int)iupper[2];

128:   /* the hypre_Box is used to zero out the matrix entries in MatZeroValues() */
129:   ex->hbox.imin[0] = hlower[0];
130:   ex->hbox.imin[1] = hlower[1];
131:   ex->hbox.imin[2] = hlower[2];
132:   ex->hbox.imax[0] = hupper[0];
133:   ex->hbox.imax[1] = hupper[1];
134:   ex->hbox.imax[2] = hupper[2];

136:   /* create the hypre grid object and set its information */
137:   PetscCheck(dof <= 1, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Currently only support for scalar problems");
138:   if (px || py || pz) {
139:     if (px == DM_BOUNDARY_PERIODIC) period[0] = (HYPRE_Int)Nx;
140:     if (py == DM_BOUNDARY_PERIODIC) period[1] = (HYPRE_Int)Ny;
141:     if (pz == DM_BOUNDARY_PERIODIC) period[2] = (HYPRE_Int)Nz;
142:   }
143:   PetscCallHYPRE(HYPRE_StructGridCreate(ex->hcomm, (HYPRE_Int)dim, &ex->hgrid));
144:   PetscCallHYPRE(HYPRE_StructGridSetExtents(ex->hgrid, hlower, hupper));
145:   PetscCallHYPRE(HYPRE_StructGridSetPeriodic(ex->hgrid, period));
146:   PetscCallHYPRE(HYPRE_StructGridAssemble(ex->hgrid));

148:   sw[5] = sw[4] = sw[3] = sw[2] = sw[1] = sw[0] = (HYPRE_Int)psw;
149:   PetscCallHYPRE(HYPRE_StructGridSetNumGhost(ex->hgrid, sw));

151:   /* create the hypre stencil object and set its information */
152:   PetscCheck(sw[0] <= 1, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Ask us to add support for wider stencils");
153:   PetscCheck(st != DMDA_STENCIL_BOX, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Ask us to add support for box stencils");
154:   if (dim == 1) {
155:     HYPRE_Int offsets[3][1] = {{-1}, {0}, {1}};
156:     ssize                   = 3;
157:     PetscCallHYPRE(HYPRE_StructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->hstencil));
158:     for (i = 0; i < ssize; i++) PetscCallHYPRE(HYPRE_StructStencilSetElement(ex->hstencil, (HYPRE_Int)i, offsets[i]));
159:   } else if (dim == 2) {
160:     HYPRE_Int offsets[5][2] = {
161:       {0,  -1},
162:       {-1, 0 },
163:       {0,  0 },
164:       {1,  0 },
165:       {0,  1 }
166:     };
167:     ssize = 5;
168:     PetscCallHYPRE(HYPRE_StructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->hstencil));
169:     for (i = 0; i < ssize; i++) PetscCallHYPRE(HYPRE_StructStencilSetElement(ex->hstencil, (HYPRE_Int)i, offsets[i]));
170:   } else if (dim == 3) {
171:     HYPRE_Int offsets[7][3] = {
172:       {0,  0,  -1},
173:       {0,  -1, 0 },
174:       {-1, 0,  0 },
175:       {0,  0,  0 },
176:       {1,  0,  0 },
177:       {0,  1,  0 },
178:       {0,  0,  1 }
179:     };
180:     ssize = 7;
181:     PetscCallHYPRE(HYPRE_StructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->hstencil));
182:     for (i = 0; i < ssize; i++) PetscCallHYPRE(HYPRE_StructStencilSetElement(ex->hstencil, (HYPRE_Int)i, offsets[i]));
183:   }

185:   /* create the HYPRE vector for rhs and solution */
186:   PetscCallHYPRE(HYPRE_StructVectorCreate(ex->hcomm, ex->hgrid, &ex->hb));
187:   PetscCallHYPRE(HYPRE_StructVectorCreate(ex->hcomm, ex->hgrid, &ex->hx));
188:   PetscCallHYPRE(HYPRE_StructVectorInitialize(ex->hb));
189:   PetscCallHYPRE(HYPRE_StructVectorInitialize(ex->hx));
190:   PetscCallHYPRE(HYPRE_StructVectorAssemble(ex->hb));
191:   PetscCallHYPRE(HYPRE_StructVectorAssemble(ex->hx));

193:   /* create the hypre matrix object and set its information */
194:   PetscCallHYPRE(HYPRE_StructMatrixCreate(ex->hcomm, ex->hgrid, ex->hstencil, &ex->hmat));
195:   PetscCallHYPRE(HYPRE_StructGridDestroy(ex->hgrid));
196:   PetscCallHYPRE(HYPRE_StructStencilDestroy(ex->hstencil));
197:   if (ex->needsinitialization) {
198:     PetscCallHYPRE(HYPRE_StructMatrixInitialize(ex->hmat));
199:     ex->needsinitialization = PETSC_FALSE;
200:   }

202:   /* set the global and local sizes of the matrix */
203:   PetscCall(DMDAGetCorners(da, 0, 0, 0, &nx, &ny, &nz));
204:   PetscCall(MatSetSizes(mat, dof * nx * ny * nz, dof * nx * ny * nz, PETSC_DECIDE, PETSC_DECIDE));
205:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, 1));
206:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, 1));
207:   PetscCall(PetscLayoutSetUp(mat->rmap));
208:   PetscCall(PetscLayoutSetUp(mat->cmap));
209:   mat->preallocated = PETSC_TRUE;

211:   PetscCheck(dim == 3, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Only support for 3d DMDA currently");
212:   mat->ops->setvalueslocal = MatSetValuesLocal_HYPREStruct_3d;
213:   mat->ops->zerorowslocal  = MatZeroRowsLocal_HYPREStruct_3d;
214:   mat->ops->zeroentries    = MatZeroEntries_HYPREStruct_3d;

216:   /*        PetscCall(MatZeroEntries_HYPREStruct_3d(mat)); */

218:   /* get values that will be used repeatedly in MatSetValuesLocal() and MatZeroRowsLocal() repeatedly */
219:   PetscCall(MatGetOwnershipRange(mat, &ex->rstart, NULL));
220:   PetscCall(DMGetLocalToGlobalMapping(ex->da, &ltog));
221:   PetscCall(ISLocalToGlobalMappingGetIndices(ltog, (const PetscInt **)&ex->gindices));
222:   PetscCall(DMDAGetGhostCorners(ex->da, 0, 0, 0, &ex->gnx, &ex->gnxgny, 0));
223:   ex->gnxgny *= ex->gnx;
224:   PetscCall(DMDAGetCorners(ex->da, &ex->xs, &ex->ys, &ex->zs, &ex->nx, &ex->ny, 0));
225:   ex->nxny = ex->nx * ex->ny;
226:   PetscFunctionReturn(PETSC_SUCCESS);
227: }

229: static PetscErrorCode MatMult_HYPREStruct(Mat A, Vec x, Vec y)
230: {
231:   const PetscScalar *xx;
232:   PetscScalar       *yy;
233:   PetscInt           ilower[3], iupper[3];
234:   HYPRE_Int          hlower[3], hupper[3];
235:   Mat_HYPREStruct   *mx = (Mat_HYPREStruct *)A->data;

237:   PetscFunctionBegin;
238:   PetscCall(DMDAGetCorners(mx->da, &ilower[0], &ilower[1], &ilower[2], &iupper[0], &iupper[1], &iupper[2]));
239:   /* when HYPRE_MIXEDINT is defined, sizeof(HYPRE_Int) == 32 */
240:   iupper[0] += ilower[0] - 1;
241:   iupper[1] += ilower[1] - 1;
242:   iupper[2] += ilower[2] - 1;
243:   hlower[0] = (HYPRE_Int)ilower[0];
244:   hlower[1] = (HYPRE_Int)ilower[1];
245:   hlower[2] = (HYPRE_Int)ilower[2];
246:   hupper[0] = (HYPRE_Int)iupper[0];
247:   hupper[1] = (HYPRE_Int)iupper[1];
248:   hupper[2] = (HYPRE_Int)iupper[2];

250:   /* copy x values over to hypre */
251:   PetscCallHYPRE(HYPRE_StructVectorSetConstantValues(mx->hb, 0.0));
252:   PetscCall(VecGetArrayRead(x, &xx));
253:   PetscCallHYPRE(HYPRE_StructVectorSetBoxValues(mx->hb, hlower, hupper, (HYPRE_Complex *)xx));
254:   PetscCall(VecRestoreArrayRead(x, &xx));
255:   PetscCallHYPRE(HYPRE_StructVectorAssemble(mx->hb));
256:   PetscCallHYPRE(HYPRE_StructMatrixMatvec(1.0, mx->hmat, mx->hb, 0.0, mx->hx));

258:   /* copy solution values back to PETSc */
259:   PetscCall(VecGetArray(y, &yy));
260:   PetscCallHYPRE(HYPRE_StructVectorGetBoxValues(mx->hx, hlower, hupper, (HYPRE_Complex *)yy));
261:   PetscCall(VecRestoreArray(y, &yy));
262:   PetscFunctionReturn(PETSC_SUCCESS);
263: }

265: static PetscErrorCode MatAssemblyEnd_HYPREStruct(Mat mat, MatAssemblyType mode)
266: {
267:   Mat_HYPREStruct *ex = (Mat_HYPREStruct *)mat->data;

269:   PetscFunctionBegin;
270:   PetscCallHYPRE(HYPRE_StructMatrixAssemble(ex->hmat));
271:   PetscFunctionReturn(PETSC_SUCCESS);
272: }

274: static PetscErrorCode MatZeroEntries_HYPREStruct(Mat mat)
275: {
276:   PetscFunctionBegin;
277:   /* before the DMDA is set to the matrix the zero doesn't need to do anything */
278:   PetscFunctionReturn(PETSC_SUCCESS);
279: }

281: static PetscErrorCode MatDestroy_HYPREStruct(Mat mat)
282: {
283:   Mat_HYPREStruct *ex = (Mat_HYPREStruct *)mat->data;

285:   PetscFunctionBegin;
286:   PetscCallHYPRE(HYPRE_StructMatrixDestroy(ex->hmat));
287:   PetscCallHYPRE(HYPRE_StructVectorDestroy(ex->hx));
288:   PetscCallHYPRE(HYPRE_StructVectorDestroy(ex->hb));
289:   PetscCall(PetscObjectDereference((PetscObject)ex->da));
290:   PetscCallMPI(MPI_Comm_free(&ex->hcomm));
291:   PetscCall(PetscFree(ex));
292:   PetscFunctionReturn(PETSC_SUCCESS);
293: }

295: PETSC_EXTERN PetscErrorCode MatCreate_HYPREStruct(Mat B)
296: {
297:   Mat_HYPREStruct *ex;

299:   PetscFunctionBegin;
300:   PetscCall(PetscNew(&ex));
301:   B->data      = (void *)ex;
302:   B->rmap->bs  = 1;
303:   B->assembled = PETSC_FALSE;

305:   B->insertmode = NOT_SET_VALUES;

307:   B->ops->assemblyend = MatAssemblyEnd_HYPREStruct;
308:   B->ops->mult        = MatMult_HYPREStruct;
309:   B->ops->zeroentries = MatZeroEntries_HYPREStruct;
310:   B->ops->destroy     = MatDestroy_HYPREStruct;
311:   B->ops->setup       = MatSetUp_HYPREStruct;

313:   ex->needsinitialization = PETSC_TRUE;

315:   PetscCallMPI(MPI_Comm_dup(PetscObjectComm((PetscObject)B), &ex->hcomm));
316:   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATHYPRESTRUCT));
317:   PetscCall(PetscHYPREInitialize());
318:   PetscFunctionReturn(PETSC_SUCCESS);
319: }

321: /*MC
322:    MATHYPRESSTRUCT - MATHYPRESSTRUCT = "hypresstruct" - A matrix type to be used for parallel sparse matrices
323:           based on the hypre HYPRE_SStructMatrix.

325:    Level: intermediate

327:    Notes:
328:     Unlike hypre's general semi-struct object consisting of a collection of structured-grid objects and unstructured
329:           grid objects, we restrict the semi-struct objects to consist of only structured-grid components.

331:           Unlike the more general support for parts and blocks in hypre this allows only one part, and one block per process and requires the block
332:           be defined by a `DMDA`.

334:           The matrix needs a DMDA associated with it by either a call to MatSetDM() or if the matrix is obtained from DMCreateMatrix()

336: .seealso: `Mat`
337: M*/

339: static PetscErrorCode MatSetValuesLocal_HYPRESStruct_3d(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
340: {
341:   HYPRE_Int         index[3], *entries;
342:   PetscInt          i, j, stencil;
343:   HYPRE_Complex    *values = (HYPRE_Complex *)y;
344:   Mat_HYPRESStruct *ex     = (Mat_HYPRESStruct *)mat->data;

346:   HYPRE_Int part = 0; /* PETSc sstruct interface only allows 1 part */
347:   PetscInt  ordering;
348:   PetscInt  grid_rank, to_grid_rank;
349:   PetscInt  var_type, to_var_type;
350:   PetscInt  to_var_entry = 0;
351:   PetscInt  nvars        = ex->nvars;
352:   PetscInt  row;

354:   PetscFunctionBegin;
355:   PetscCall(PetscMalloc1(7 * nvars, &entries));
356:   ordering = ex->dofs_order; /* ordering= 0   nodal ordering
357:                                            1   variable ordering */
358:   /* stencil entries are ordered by variables: var0_stencil0, var0_stencil1, ..., var0_stencil6, var1_stencil0, var1_stencil1, ...  */
359:   if (!ordering) {
360:     for (i = 0; i < nrow; i++) {
361:       grid_rank = irow[i] / nvars;
362:       var_type  = (irow[i] % nvars);

364:       for (j = 0; j < ncol; j++) {
365:         to_grid_rank = icol[j] / nvars;
366:         to_var_type  = (icol[j] % nvars);

368:         to_var_entry = to_var_entry * 7;
369:         entries[j]   = (HYPRE_Int)to_var_entry;

371:         stencil = to_grid_rank - grid_rank;
372:         if (!stencil) {
373:           entries[j] += 3;
374:         } else if (stencil == -1) {
375:           entries[j] += 2;
376:         } else if (stencil == 1) {
377:           entries[j] += 4;
378:         } else if (stencil == -ex->gnx) {
379:           entries[j] += 1;
380:         } else if (stencil == ex->gnx) {
381:           entries[j] += 5;
382:         } else if (stencil == -ex->gnxgny) {
383:           entries[j] += 0;
384:         } else if (stencil == ex->gnxgny) {
385:           entries[j] += 6;
386:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Local row %" PetscInt_FMT " local column %" PetscInt_FMT " have bad stencil %" PetscInt_FMT, irow[i], icol[j], stencil);
387:       }

389:       row      = ex->gindices[grid_rank] - ex->rstart;
390:       index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
391:       index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
392:       index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));

394:       if (addv == ADD_VALUES) PetscCallHYPRE(HYPRE_SStructMatrixAddToValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, (HYPRE_Int)ncol, entries, values));
395:       else PetscCallHYPRE(HYPRE_SStructMatrixSetValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, (HYPRE_Int)ncol, entries, values));
396:       values += ncol;
397:     }
398:   } else {
399:     for (i = 0; i < nrow; i++) {
400:       var_type  = irow[i] / (ex->gnxgnygnz);
401:       grid_rank = irow[i] - var_type * (ex->gnxgnygnz);

403:       for (j = 0; j < ncol; j++) {
404:         to_var_type  = icol[j] / (ex->gnxgnygnz);
405:         to_grid_rank = icol[j] - to_var_type * (ex->gnxgnygnz);

407:         to_var_entry = to_var_entry * 7;
408:         entries[j]   = (HYPRE_Int)to_var_entry;

410:         stencil = to_grid_rank - grid_rank;
411:         if (!stencil) {
412:           entries[j] += 3;
413:         } else if (stencil == -1) {
414:           entries[j] += 2;
415:         } else if (stencil == 1) {
416:           entries[j] += 4;
417:         } else if (stencil == -ex->gnx) {
418:           entries[j] += 1;
419:         } else if (stencil == ex->gnx) {
420:           entries[j] += 5;
421:         } else if (stencil == -ex->gnxgny) {
422:           entries[j] += 0;
423:         } else if (stencil == ex->gnxgny) {
424:           entries[j] += 6;
425:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Local row %" PetscInt_FMT " local column %" PetscInt_FMT " have bad stencil %" PetscInt_FMT, irow[i], icol[j], stencil);
426:       }

428:       row      = ex->gindices[grid_rank] - ex->rstart;
429:       index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
430:       index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
431:       index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));

433:       if (addv == ADD_VALUES) PetscCallHYPRE(HYPRE_SStructMatrixAddToValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, (HYPRE_Int)ncol, entries, values));
434:       else PetscCallHYPRE(HYPRE_SStructMatrixSetValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, (HYPRE_Int)ncol, entries, values));
435:       values += ncol;
436:     }
437:   }
438:   PetscCall(PetscFree(entries));
439:   PetscFunctionReturn(PETSC_SUCCESS);
440: }

442: static PetscErrorCode MatZeroRowsLocal_HYPRESStruct_3d(Mat mat, PetscInt nrow, const PetscInt irow[], PetscScalar d, Vec x, Vec b)
443: {
444:   HYPRE_Int         index[3], *entries;
445:   PetscInt          i;
446:   HYPRE_Complex   **values;
447:   Mat_HYPRESStruct *ex = (Mat_HYPRESStruct *)mat->data;

449:   HYPRE_Int part     = 0; /* PETSc sstruct interface only allows 1 part */
450:   PetscInt  ordering = ex->dofs_order;
451:   PetscInt  grid_rank;
452:   PetscInt  var_type;
453:   PetscInt  nvars = ex->nvars;
454:   PetscInt  row;

456:   PetscFunctionBegin;
457:   PetscCheck(!x || !b, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "No support");
458:   PetscCall(PetscMalloc1(7 * nvars, &entries));

460:   PetscCall(PetscMalloc1(nvars, &values));
461:   PetscCall(PetscMalloc1(7 * nvars * nvars, &values[0]));
462:   for (i = 1; i < nvars; i++) values[i] = values[i - 1] + nvars * 7;

464:   for (i = 0; i < nvars; i++) {
465:     PetscCall(PetscArrayzero(values[i], nvars * 7 * sizeof(HYPRE_Complex)));
466:     PetscCall(PetscHYPREScalarCast(d, values[i] + 3));
467:   }

469:   for (i = 0; i < nvars * 7; i++) entries[i] = (HYPRE_Int)i;

471:   if (!ordering) {
472:     for (i = 0; i < nrow; i++) {
473:       grid_rank = irow[i] / nvars;
474:       var_type  = (irow[i] % nvars);

476:       row      = ex->gindices[grid_rank] - ex->rstart;
477:       index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
478:       index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
479:       index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));
480:       PetscCallHYPRE(HYPRE_SStructMatrixSetValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, 7 * (HYPRE_Int)nvars, entries, values[var_type]));
481:     }
482:   } else {
483:     for (i = 0; i < nrow; i++) {
484:       var_type  = irow[i] / (ex->gnxgnygnz);
485:       grid_rank = irow[i] - var_type * (ex->gnxgnygnz);

487:       row      = ex->gindices[grid_rank] - ex->rstart;
488:       index[0] = (HYPRE_Int)(ex->xs + (row % ex->nx));
489:       index[1] = (HYPRE_Int)(ex->ys + ((row / ex->nx) % ex->ny));
490:       index[2] = (HYPRE_Int)(ex->zs + (row / (ex->nxny)));
491:       PetscCallHYPRE(HYPRE_SStructMatrixSetValues(ex->ss_mat, part, index, (HYPRE_Int)var_type, 7 * (HYPRE_Int)nvars, entries, values[var_type]));
492:     }
493:   }
494:   PetscCallHYPRE(HYPRE_SStructMatrixAssemble(ex->ss_mat));
495:   PetscCall(PetscFree(values[0]));
496:   PetscCall(PetscFree(values));
497:   PetscCall(PetscFree(entries));
498:   PetscFunctionReturn(PETSC_SUCCESS);
499: }

501: static PetscErrorCode MatZeroEntries_HYPRESStruct_3d(Mat mat)
502: {
503:   Mat_HYPRESStruct *ex    = (Mat_HYPRESStruct *)mat->data;
504:   PetscInt          nvars = ex->nvars;
505:   PetscInt          size;
506:   HYPRE_Int         part = 0; /* only one part */

508:   PetscFunctionBegin;
509:   size = (ex->hbox.imax[0] - ex->hbox.imin[0] + 1) * (ex->hbox.imax[1] - ex->hbox.imin[1] + 1) * (ex->hbox.imax[2] - ex->hbox.imin[2] + 1);
510:   {
511:     HYPRE_Int      i, *entries, iupper[3], ilower[3];
512:     HYPRE_Complex *values;

514:     for (i = 0; i < 3; i++) {
515:       ilower[i] = (HYPRE_Int)ex->hbox.imin[i];
516:       iupper[i] = (HYPRE_Int)ex->hbox.imax[i];
517:     }

519:     PetscCall(PetscMalloc2(nvars * 7, &entries, nvars * 7 * size, &values));
520:     for (i = 0; i < nvars * 7; i++) entries[i] = i;
521:     PetscCall(PetscArrayzero(values, nvars * 7 * size));

523:     for (i = 0; i < nvars; i++) PetscCallHYPRE(HYPRE_SStructMatrixSetBoxValues(ex->ss_mat, part, ilower, iupper, (HYPRE_Int)i, (HYPRE_Int)nvars * 7, entries, values));
524:     PetscCall(PetscFree2(entries, values));
525:   }
526:   PetscCallHYPRE(HYPRE_SStructMatrixAssemble(ex->ss_mat));
527:   PetscFunctionReturn(PETSC_SUCCESS);
528: }

530: static PetscErrorCode MatSetUp_HYPRESStruct(Mat mat)
531: {
532:   Mat_HYPRESStruct      *ex = (Mat_HYPRESStruct *)mat->data;
533:   PetscInt               dim, dof, sw[3], nx, ny, nz;
534:   PetscInt               ilower[3], iupper[3], ssize, i;
535:   DMBoundaryType         px, py, pz;
536:   DMDAStencilType        st;
537:   PetscInt               nparts = 1; /* assuming only one part */
538:   HYPRE_Int              part   = 0;
539:   ISLocalToGlobalMapping ltog;
540:   DM                     da;

542:   PetscFunctionBegin;
543:   PetscCall(MatGetDM(mat, (DM *)&da));
544:   ex->da = da;
545:   PetscCall(PetscObjectReference((PetscObject)da));

547:   PetscCall(DMDAGetInfo(ex->da, &dim, 0, 0, 0, 0, 0, 0, &dof, &sw[0], &px, &py, &pz, &st));
548:   PetscCall(DMDAGetCorners(ex->da, &ilower[0], &ilower[1], &ilower[2], &iupper[0], &iupper[1], &iupper[2]));
549:   iupper[0] += ilower[0] - 1;
550:   iupper[1] += ilower[1] - 1;
551:   iupper[2] += ilower[2] - 1;
552:   /* the hypre_Box is used to zero out the matrix entries in MatZeroValues() */
553:   ex->hbox.imin[0] = (HYPRE_Int)ilower[0];
554:   ex->hbox.imin[1] = (HYPRE_Int)ilower[1];
555:   ex->hbox.imin[2] = (HYPRE_Int)ilower[2];
556:   ex->hbox.imax[0] = (HYPRE_Int)iupper[0];
557:   ex->hbox.imax[1] = (HYPRE_Int)iupper[1];
558:   ex->hbox.imax[2] = (HYPRE_Int)iupper[2];

560:   ex->dofs_order = 0;

562:   /* assuming that the same number of dofs on each gridpoint. Also assume all cell-centred based */
563:   ex->nvars = (int)dof;

565:   /* create the hypre grid object and set its information */
566:   PetscCheck(!px && !py && !pz, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Ask us to add periodic support by calling HYPRE_SStructGridSetPeriodic()");
567:   PetscCallHYPRE(HYPRE_SStructGridCreate(ex->hcomm, (HYPRE_Int)dim, (HYPRE_Int)nparts, &ex->ss_grid));
568:   PetscCallHYPRE(HYPRE_SStructGridSetExtents(ex->ss_grid, part, ex->hbox.imin, ex->hbox.imax));
569:   {
570:     HYPRE_SStructVariable *vartypes;
571:     PetscCall(PetscMalloc1(ex->nvars, &vartypes));
572:     for (i = 0; i < ex->nvars; i++) vartypes[i] = HYPRE_SSTRUCT_VARIABLE_CELL;
573:     PetscCallHYPRE(HYPRE_SStructGridSetVariables(ex->ss_grid, part, (HYPRE_Int)ex->nvars, vartypes));
574:     PetscCall(PetscFree(vartypes));
575:   }
576:   PetscCallHYPRE(HYPRE_SStructGridAssemble(ex->ss_grid));

578:   sw[1] = sw[0];
579:   sw[2] = sw[1];
580:   /* PetscCallHYPRE(HYPRE_SStructGridSetNumGhost(ex->ss_grid,sw)); */

582:   /* create the hypre stencil object and set its information */
583:   PetscCheck(sw[0] <= 1, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Ask us to add support for wider stencils");
584:   PetscCheck(st != DMDA_STENCIL_BOX, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Ask us to add support for box stencils");

586:   if (dim == 1) {
587:     HYPRE_Int offsets[3][1] = {{-1}, {0}, {1}};
588:     PetscInt  j, cnt;

590:     ssize = 3 * (ex->nvars);
591:     PetscCallHYPRE(HYPRE_SStructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->ss_stencil));
592:     cnt = 0;
593:     for (i = 0; i < (ex->nvars); i++) {
594:       for (j = 0; j < 3; j++) {
595:         PetscCallHYPRE(HYPRE_SStructStencilSetEntry(ex->ss_stencil, (HYPRE_Int)cnt, offsets[j], (HYPRE_Int)i));
596:         cnt++;
597:       }
598:     }
599:   } else if (dim == 2) {
600:     HYPRE_Int offsets[5][2] = {
601:       {0,  -1},
602:       {-1, 0 },
603:       {0,  0 },
604:       {1,  0 },
605:       {0,  1 }
606:     };
607:     PetscInt j, cnt;

609:     ssize = 5 * (ex->nvars);
610:     PetscCallHYPRE(HYPRE_SStructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->ss_stencil));
611:     cnt = 0;
612:     for (i = 0; i < (ex->nvars); i++) {
613:       for (j = 0; j < 5; j++) {
614:         PetscCallHYPRE(HYPRE_SStructStencilSetEntry(ex->ss_stencil, (HYPRE_Int)cnt, offsets[j], (HYPRE_Int)i));
615:         cnt++;
616:       }
617:     }
618:   } else if (dim == 3) {
619:     HYPRE_Int offsets[7][3] = {
620:       {0,  0,  -1},
621:       {0,  -1, 0 },
622:       {-1, 0,  0 },
623:       {0,  0,  0 },
624:       {1,  0,  0 },
625:       {0,  1,  0 },
626:       {0,  0,  1 }
627:     };
628:     PetscInt j, cnt;

630:     ssize = 7 * (ex->nvars);
631:     PetscCallHYPRE(HYPRE_SStructStencilCreate((HYPRE_Int)dim, (HYPRE_Int)ssize, &ex->ss_stencil));
632:     cnt = 0;
633:     for (i = 0; i < (ex->nvars); i++) {
634:       for (j = 0; j < 7; j++) {
635:         PetscCallHYPRE(HYPRE_SStructStencilSetEntry(ex->ss_stencil, (HYPRE_Int)cnt, offsets[j], (HYPRE_Int)i));
636:         cnt++;
637:       }
638:     }
639:   }

641:   /* create the HYPRE graph */
642:   PetscCallHYPRE(HYPRE_SStructGraphCreate(ex->hcomm, ex->ss_grid, &ex->ss_graph));

644:   /* set the stencil graph. Note that each variable has the same graph. This means that each
645:      variable couples to all the other variable and with the same stencil pattern. */
646:   for (i = 0; i < (ex->nvars); i++) PetscCallHYPRE(HYPRE_SStructGraphSetStencil(ex->ss_graph, part, (HYPRE_Int)i, ex->ss_stencil));
647:   PetscCallHYPRE(HYPRE_SStructGraphAssemble(ex->ss_graph));

649:   /* create the HYPRE sstruct vectors for rhs and solution */
650:   PetscCallHYPRE(HYPRE_SStructVectorCreate(ex->hcomm, ex->ss_grid, &ex->ss_b));
651:   PetscCallHYPRE(HYPRE_SStructVectorCreate(ex->hcomm, ex->ss_grid, &ex->ss_x));
652:   PetscCallHYPRE(HYPRE_SStructVectorInitialize(ex->ss_b));
653:   PetscCallHYPRE(HYPRE_SStructVectorInitialize(ex->ss_x));
654:   PetscCallHYPRE(HYPRE_SStructVectorAssemble(ex->ss_b));
655:   PetscCallHYPRE(HYPRE_SStructVectorAssemble(ex->ss_x));

657:   /* create the hypre matrix object and set its information */
658:   PetscCallHYPRE(HYPRE_SStructMatrixCreate(ex->hcomm, ex->ss_graph, &ex->ss_mat));
659:   PetscCallHYPRE(HYPRE_SStructGridDestroy(ex->ss_grid));
660:   PetscCallHYPRE(HYPRE_SStructStencilDestroy(ex->ss_stencil));
661:   if (ex->needsinitialization) {
662:     PetscCallHYPRE(HYPRE_SStructMatrixInitialize(ex->ss_mat));
663:     ex->needsinitialization = PETSC_FALSE;
664:   }

666:   /* set the global and local sizes of the matrix */
667:   PetscCall(DMDAGetCorners(da, 0, 0, 0, &nx, &ny, &nz));
668:   PetscCall(MatSetSizes(mat, dof * nx * ny * nz, dof * nx * ny * nz, PETSC_DECIDE, PETSC_DECIDE));
669:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, dof));
670:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, dof));
671:   PetscCall(PetscLayoutSetUp(mat->rmap));
672:   PetscCall(PetscLayoutSetUp(mat->cmap));
673:   mat->preallocated = PETSC_TRUE;

675:   PetscCheck(dim == 3, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Only support for 3d DMDA currently");
676:   mat->ops->setvalueslocal = MatSetValuesLocal_HYPRESStruct_3d;
677:   mat->ops->zerorowslocal  = MatZeroRowsLocal_HYPRESStruct_3d;
678:   mat->ops->zeroentries    = MatZeroEntries_HYPRESStruct_3d;

680:   /* PetscCall(MatZeroEntries_HYPRESStruct_3d(mat)); */

682:   /* get values that will be used repeatedly in MatSetValuesLocal() and MatZeroRowsLocal() repeatedly */
683:   PetscCall(MatGetOwnershipRange(mat, &ex->rstart, NULL));
684:   PetscCall(DMGetLocalToGlobalMapping(ex->da, &ltog));
685:   PetscCall(ISLocalToGlobalMappingGetIndices(ltog, (const PetscInt **)&ex->gindices));
686:   PetscCall(DMDAGetGhostCorners(ex->da, 0, 0, 0, &ex->gnx, &ex->gnxgny, &ex->gnxgnygnz));

688:   ex->gnxgny *= ex->gnx;
689:   ex->gnxgnygnz *= ex->gnxgny;

691:   PetscCall(DMDAGetCorners(ex->da, &ex->xs, &ex->ys, &ex->zs, &ex->nx, &ex->ny, &ex->nz));

693:   ex->nxny   = ex->nx * ex->ny;
694:   ex->nxnynz = ex->nz * ex->nxny;
695:   PetscFunctionReturn(PETSC_SUCCESS);
696: }

698: static PetscErrorCode MatMult_HYPRESStruct(Mat A, Vec x, Vec y)
699: {
700:   const PetscScalar *xx;
701:   PetscScalar       *yy;
702:   HYPRE_Int          hlower[3], hupper[3];
703:   PetscInt           ilower[3], iupper[3];
704:   Mat_HYPRESStruct  *mx       = (Mat_HYPRESStruct *)A->data;
705:   PetscInt           ordering = mx->dofs_order;
706:   PetscInt           nvars    = mx->nvars;
707:   HYPRE_Int          part     = 0;
708:   PetscInt           size;
709:   PetscInt           i;

711:   PetscFunctionBegin;
712:   PetscCall(DMDAGetCorners(mx->da, &ilower[0], &ilower[1], &ilower[2], &iupper[0], &iupper[1], &iupper[2]));

714:   /* when HYPRE_MIXEDINT is defined, sizeof(HYPRE_Int) == 32 */
715:   iupper[0] += ilower[0] - 1;
716:   iupper[1] += ilower[1] - 1;
717:   iupper[2] += ilower[2] - 1;
718:   hlower[0] = (HYPRE_Int)ilower[0];
719:   hlower[1] = (HYPRE_Int)ilower[1];
720:   hlower[2] = (HYPRE_Int)ilower[2];
721:   hupper[0] = (HYPRE_Int)iupper[0];
722:   hupper[1] = (HYPRE_Int)iupper[1];
723:   hupper[2] = (HYPRE_Int)iupper[2];

725:   size = 1;
726:   for (i = 0; i < 3; i++) size *= (iupper[i] - ilower[i] + 1);

728:   /* copy x values over to hypre for variable ordering */
729:   if (ordering) {
730:     PetscCallHYPRE(HYPRE_SStructVectorSetConstantValues(mx->ss_b, 0.0));
731:     PetscCall(VecGetArrayRead(x, &xx));
732:     for (i = 0; i < nvars; i++) PetscCallHYPRE(HYPRE_SStructVectorSetBoxValues(mx->ss_b, part, hlower, hupper, (HYPRE_Int)i, (HYPRE_Complex *)(xx + (size * i))));
733:     PetscCall(VecRestoreArrayRead(x, &xx));
734:     PetscCallHYPRE(HYPRE_SStructVectorAssemble(mx->ss_b));
735:     PetscCallHYPRE(HYPRE_SStructMatrixMatvec(1.0, mx->ss_mat, mx->ss_b, 0.0, mx->ss_x));

737:     /* copy solution values back to PETSc */
738:     PetscCall(VecGetArray(y, &yy));
739:     for (i = 0; i < nvars; i++) PetscCallHYPRE(HYPRE_SStructVectorGetBoxValues(mx->ss_x, part, hlower, hupper, (HYPRE_Int)i, (HYPRE_Complex *)(yy + (size * i))));
740:     PetscCall(VecRestoreArray(y, &yy));
741:   } else { /* nodal ordering must be mapped to variable ordering for sys_pfmg */
742:     PetscScalar *z;
743:     PetscInt     j, k;

745:     PetscCall(PetscMalloc1(nvars * size, &z));
746:     PetscCallHYPRE(HYPRE_SStructVectorSetConstantValues(mx->ss_b, 0.0));
747:     PetscCall(VecGetArrayRead(x, &xx));

749:     /* transform nodal to hypre's variable ordering for sys_pfmg */
750:     for (i = 0; i < size; i++) {
751:       k = i * nvars;
752:       for (j = 0; j < nvars; j++) z[j * size + i] = xx[k + j];
753:     }
754:     for (i = 0; i < nvars; i++) PetscCallHYPRE(HYPRE_SStructVectorSetBoxValues(mx->ss_b, part, hlower, hupper, (HYPRE_Int)i, (HYPRE_Complex *)(z + (size * i))));
755:     PetscCall(VecRestoreArrayRead(x, &xx));
756:     PetscCallHYPRE(HYPRE_SStructVectorAssemble(mx->ss_b));
757:     PetscCallHYPRE(HYPRE_SStructMatrixMatvec(1.0, mx->ss_mat, mx->ss_b, 0.0, mx->ss_x));

759:     /* copy solution values back to PETSc */
760:     PetscCall(VecGetArray(y, &yy));
761:     for (i = 0; i < nvars; i++) PetscCallHYPRE(HYPRE_SStructVectorGetBoxValues(mx->ss_x, part, hlower, hupper, (HYPRE_Int)i, (HYPRE_Complex *)(z + (size * i))));
762:     /* transform hypre's variable ordering for sys_pfmg to nodal ordering */
763:     for (i = 0; i < size; i++) {
764:       k = i * nvars;
765:       for (j = 0; j < nvars; j++) yy[k + j] = z[j * size + i];
766:     }
767:     PetscCall(VecRestoreArray(y, &yy));
768:     PetscCall(PetscFree(z));
769:   }
770:   PetscFunctionReturn(PETSC_SUCCESS);
771: }

773: static PetscErrorCode MatAssemblyEnd_HYPRESStruct(Mat mat, MatAssemblyType mode)
774: {
775:   Mat_HYPRESStruct *ex = (Mat_HYPRESStruct *)mat->data;

777:   PetscFunctionBegin;
778:   PetscCallHYPRE(HYPRE_SStructMatrixAssemble(ex->ss_mat));
779:   PetscFunctionReturn(PETSC_SUCCESS);
780: }

782: static PetscErrorCode MatZeroEntries_HYPRESStruct(Mat mat)
783: {
784:   PetscFunctionBegin;
785:   /* before the DMDA is set to the matrix the zero doesn't need to do anything */
786:   PetscFunctionReturn(PETSC_SUCCESS);
787: }

789: static PetscErrorCode MatDestroy_HYPRESStruct(Mat mat)
790: {
791:   Mat_HYPRESStruct      *ex = (Mat_HYPRESStruct *)mat->data;
792:   ISLocalToGlobalMapping ltog;

794:   PetscFunctionBegin;
795:   PetscCall(DMGetLocalToGlobalMapping(ex->da, &ltog));
796:   PetscCall(ISLocalToGlobalMappingRestoreIndices(ltog, (const PetscInt **)&ex->gindices));
797:   PetscCallHYPRE(HYPRE_SStructGraphDestroy(ex->ss_graph));
798:   PetscCallHYPRE(HYPRE_SStructMatrixDestroy(ex->ss_mat));
799:   PetscCallHYPRE(HYPRE_SStructVectorDestroy(ex->ss_x));
800:   PetscCallHYPRE(HYPRE_SStructVectorDestroy(ex->ss_b));
801:   PetscCall(PetscObjectDereference((PetscObject)ex->da));
802:   PetscCallMPI(MPI_Comm_free(&ex->hcomm));
803:   PetscCall(PetscFree(ex));
804:   PetscFunctionReturn(PETSC_SUCCESS);
805: }

807: PETSC_EXTERN PetscErrorCode MatCreate_HYPRESStruct(Mat B)
808: {
809:   Mat_HYPRESStruct *ex;

811:   PetscFunctionBegin;
812:   PetscCall(PetscNew(&ex));
813:   B->data      = (void *)ex;
814:   B->rmap->bs  = 1;
815:   B->assembled = PETSC_FALSE;

817:   B->insertmode = NOT_SET_VALUES;

819:   B->ops->assemblyend = MatAssemblyEnd_HYPRESStruct;
820:   B->ops->mult        = MatMult_HYPRESStruct;
821:   B->ops->zeroentries = MatZeroEntries_HYPRESStruct;
822:   B->ops->destroy     = MatDestroy_HYPRESStruct;
823:   B->ops->setup       = MatSetUp_HYPRESStruct;

825:   ex->needsinitialization = PETSC_TRUE;

827:   PetscCallMPI(MPI_Comm_dup(PetscObjectComm((PetscObject)B), &ex->hcomm));
828:   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATHYPRESSTRUCT));
829:   PetscCall(PetscHYPREInitialize());
830:   PetscFunctionReturn(PETSC_SUCCESS);
831: }