xref: /petsc/src/ksp/pc/impls/bddc/bddcfetidp.c (revision df4cd43f92eaa320656440c40edb1046daee8f75)
1 #include <petsc/private/pcbddcimpl.h>
2 #include <petsc/private/pcbddcprivateimpl.h>
3 #include <petscblaslapack.h>
4 
5 static PetscErrorCode MatMult_BDdelta_deluxe_nonred(Mat A, Vec x, Vec y)
6 {
7   BDdelta_DN ctx;
8 
9   PetscFunctionBegin;
10   PetscCall(MatShellGetContext(A, &ctx));
11   PetscCall(MatMultTranspose(ctx->BD, x, ctx->work));
12   PetscCall(KSPSolveTranspose(ctx->kBD, ctx->work, y));
13   /* No PC so cannot propagate up failure in KSPSolveTranspose() */
14   PetscFunctionReturn(PETSC_SUCCESS);
15 }
16 
17 static PetscErrorCode MatMultTranspose_BDdelta_deluxe_nonred(Mat A, Vec x, Vec y)
18 {
19   BDdelta_DN ctx;
20 
21   PetscFunctionBegin;
22   PetscCall(MatShellGetContext(A, &ctx));
23   PetscCall(KSPSolve(ctx->kBD, x, ctx->work));
24   /* No PC so cannot propagate up failure in KSPSolve() */
25   PetscCall(MatMult(ctx->BD, ctx->work, y));
26   PetscFunctionReturn(PETSC_SUCCESS);
27 }
28 
29 static PetscErrorCode MatDestroy_BDdelta_deluxe_nonred(Mat A)
30 {
31   BDdelta_DN ctx;
32 
33   PetscFunctionBegin;
34   PetscCall(MatShellGetContext(A, &ctx));
35   PetscCall(MatDestroy(&ctx->BD));
36   PetscCall(KSPDestroy(&ctx->kBD));
37   PetscCall(VecDestroy(&ctx->work));
38   PetscCall(PetscFree(ctx));
39   PetscFunctionReturn(PETSC_SUCCESS);
40 }
41 
42 PetscErrorCode PCBDDCCreateFETIDPMatContext(PC pc, FETIDPMat_ctx *fetidpmat_ctx)
43 {
44   FETIDPMat_ctx newctx;
45 
46   PetscFunctionBegin;
47   PetscCall(PetscNew(&newctx));
48   /* increase the reference count for BDDC preconditioner */
49   PetscCall(PetscObjectReference((PetscObject)pc));
50   newctx->pc     = pc;
51   *fetidpmat_ctx = newctx;
52   PetscFunctionReturn(PETSC_SUCCESS);
53 }
54 
55 PetscErrorCode PCBDDCCreateFETIDPPCContext(PC pc, FETIDPPC_ctx *fetidppc_ctx)
56 {
57   FETIDPPC_ctx newctx;
58 
59   PetscFunctionBegin;
60   PetscCall(PetscNew(&newctx));
61   /* increase the reference count for BDDC preconditioner */
62   PetscCall(PetscObjectReference((PetscObject)pc));
63   newctx->pc    = pc;
64   *fetidppc_ctx = newctx;
65   PetscFunctionReturn(PETSC_SUCCESS);
66 }
67 
68 PetscErrorCode PCBDDCDestroyFETIDPMat(Mat A)
69 {
70   FETIDPMat_ctx mat_ctx;
71 
72   PetscFunctionBegin;
73   PetscCall(MatShellGetContext(A, &mat_ctx));
74   PetscCall(VecDestroy(&mat_ctx->lambda_local));
75   PetscCall(VecDestroy(&mat_ctx->temp_solution_D));
76   PetscCall(VecDestroy(&mat_ctx->temp_solution_B));
77   PetscCall(MatDestroy(&mat_ctx->B_delta));
78   PetscCall(MatDestroy(&mat_ctx->B_Ddelta));
79   PetscCall(MatDestroy(&mat_ctx->B_BB));
80   PetscCall(MatDestroy(&mat_ctx->B_BI));
81   PetscCall(MatDestroy(&mat_ctx->Bt_BB));
82   PetscCall(MatDestroy(&mat_ctx->Bt_BI));
83   PetscCall(MatDestroy(&mat_ctx->C));
84   PetscCall(VecDestroy(&mat_ctx->rhs_flip));
85   PetscCall(VecDestroy(&mat_ctx->vP));
86   PetscCall(VecDestroy(&mat_ctx->xPg));
87   PetscCall(VecDestroy(&mat_ctx->yPg));
88   PetscCall(VecScatterDestroy(&mat_ctx->l2g_lambda));
89   PetscCall(VecScatterDestroy(&mat_ctx->l2g_lambda_only));
90   PetscCall(VecScatterDestroy(&mat_ctx->l2g_p));
91   PetscCall(VecScatterDestroy(&mat_ctx->g2g_p));
92   PetscCall(PCDestroy(&mat_ctx->pc)); /* decrease PCBDDC reference count */
93   PetscCall(ISDestroy(&mat_ctx->pressure));
94   PetscCall(ISDestroy(&mat_ctx->lagrange));
95   PetscCall(PetscFree(mat_ctx));
96   PetscFunctionReturn(PETSC_SUCCESS);
97 }
98 
99 PetscErrorCode PCBDDCDestroyFETIDPPC(PC pc)
100 {
101   FETIDPPC_ctx pc_ctx;
102 
103   PetscFunctionBegin;
104   PetscCall(PCShellGetContext(pc, &pc_ctx));
105   PetscCall(VecDestroy(&pc_ctx->lambda_local));
106   PetscCall(MatDestroy(&pc_ctx->B_Ddelta));
107   PetscCall(VecScatterDestroy(&pc_ctx->l2g_lambda));
108   PetscCall(MatDestroy(&pc_ctx->S_j));
109   PetscCall(PCDestroy(&pc_ctx->pc)); /* decrease PCBDDC reference count */
110   PetscCall(VecDestroy(&pc_ctx->xPg));
111   PetscCall(VecDestroy(&pc_ctx->yPg));
112   PetscCall(PetscFree(pc_ctx));
113   PetscFunctionReturn(PETSC_SUCCESS);
114 }
115 
116 PetscErrorCode PCBDDCSetupFETIDPMatContext(FETIDPMat_ctx fetidpmat_ctx)
117 {
118   PC_IS          *pcis      = (PC_IS *)fetidpmat_ctx->pc->data;
119   PC_BDDC        *pcbddc    = (PC_BDDC *)fetidpmat_ctx->pc->data;
120   PCBDDCGraph     mat_graph = pcbddc->mat_graph;
121   Mat_IS         *matis     = (Mat_IS *)fetidpmat_ctx->pc->pmat->data;
122   MPI_Comm        comm;
123   Mat             ScalingMat, BD1, BD2;
124   Vec             fetidp_global;
125   IS              IS_l2g_lambda;
126   IS              subset, subset_mult, subset_n, isvert;
127   PetscBool       skip_node, fully_redundant;
128   PetscInt        i, j, k, s, n_boundary_dofs, n_global_lambda, n_vertices, partial_sum;
129   PetscInt        cum, n_local_lambda, n_lambda_for_dof, dual_size, n_neg_values, n_pos_values;
130   PetscMPIInt     rank, size, buf_size, neigh;
131   PetscScalar     scalar_value;
132   const PetscInt *vertex_indices;
133   PetscInt       *dual_dofs_boundary_indices, *aux_local_numbering_1;
134   const PetscInt *aux_global_numbering;
135   PetscInt       *aux_sums, *cols_B_delta, *l2g_indices;
136   PetscScalar    *array, *scaling_factors, *vals_B_delta;
137   PetscScalar   **all_factors;
138   PetscInt       *aux_local_numbering_2;
139   PetscLayout     llay;
140 
141   /* saddlepoint */
142   ISLocalToGlobalMapping l2gmap_p;
143   PetscLayout            play;
144   IS                     gP, pP;
145   PetscInt               nPl, nPg, nPgl;
146 
147   PetscFunctionBegin;
148   PetscCall(PetscObjectGetComm((PetscObject)(fetidpmat_ctx->pc), &comm));
149   PetscCallMPI(MPI_Comm_rank(comm, &rank));
150   PetscCallMPI(MPI_Comm_size(comm, &size));
151 
152   /* saddlepoint */
153   nPl      = 0;
154   nPg      = 0;
155   nPgl     = 0;
156   gP       = NULL;
157   pP       = NULL;
158   l2gmap_p = NULL;
159   play     = NULL;
160   PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_pP", (PetscObject *)&pP));
161   if (pP) { /* saddle point */
162     /* subdomain pressures in global numbering */
163     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_gP", (PetscObject *)&gP));
164     PetscCheck(gP, PETSC_COMM_SELF, PETSC_ERR_PLIB, "gP not present");
165     PetscCall(ISGetLocalSize(gP, &nPl));
166     PetscCall(VecCreate(PETSC_COMM_SELF, &fetidpmat_ctx->vP));
167     PetscCall(VecSetSizes(fetidpmat_ctx->vP, nPl, nPl));
168     PetscCall(VecSetType(fetidpmat_ctx->vP, VECSTANDARD));
169     PetscCall(VecSetUp(fetidpmat_ctx->vP));
170 
171     /* pressure matrix */
172     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_C", (PetscObject *)&fetidpmat_ctx->C));
173     if (!fetidpmat_ctx->C) { /* null pressure block, compute layout and global numbering for pressures */
174       IS Pg;
175 
176       PetscCall(ISRenumber(gP, NULL, &nPg, &Pg));
177       PetscCall(ISLocalToGlobalMappingCreateIS(Pg, &l2gmap_p));
178       PetscCall(ISDestroy(&Pg));
179       PetscCall(PetscLayoutCreate(comm, &play));
180       PetscCall(PetscLayoutSetBlockSize(play, 1));
181       PetscCall(PetscLayoutSetSize(play, nPg));
182       PetscCall(ISGetLocalSize(pP, &nPgl));
183       PetscCall(PetscLayoutSetLocalSize(play, nPgl));
184       PetscCall(PetscLayoutSetUp(play));
185     } else {
186       PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->C));
187       PetscCall(MatISGetLocalToGlobalMapping(fetidpmat_ctx->C, &l2gmap_p, NULL));
188       PetscCall(PetscObjectReference((PetscObject)l2gmap_p));
189       PetscCall(MatGetSize(fetidpmat_ctx->C, &nPg, NULL));
190       PetscCall(MatGetLocalSize(fetidpmat_ctx->C, NULL, &nPgl));
191       PetscCall(MatGetLayouts(fetidpmat_ctx->C, NULL, &llay));
192       PetscCall(PetscLayoutReference(llay, &play));
193     }
194     PetscCall(VecCreateMPIWithArray(comm, 1, nPgl, nPg, NULL, &fetidpmat_ctx->xPg));
195     PetscCall(VecCreateMPIWithArray(comm, 1, nPgl, nPg, NULL, &fetidpmat_ctx->yPg));
196 
197     /* import matrices for pressures coupling */
198     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_B_BI", (PetscObject *)&fetidpmat_ctx->B_BI));
199     PetscCheck(fetidpmat_ctx->B_BI, PETSC_COMM_SELF, PETSC_ERR_PLIB, "B_BI not present");
200     PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->B_BI));
201 
202     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_B_BB", (PetscObject *)&fetidpmat_ctx->B_BB));
203     PetscCheck(fetidpmat_ctx->B_BB, PETSC_COMM_SELF, PETSC_ERR_PLIB, "B_BB not present");
204     PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->B_BB));
205 
206     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_Bt_BI", (PetscObject *)&fetidpmat_ctx->Bt_BI));
207     PetscCheck(fetidpmat_ctx->Bt_BI, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Bt_BI not present");
208     PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->Bt_BI));
209 
210     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_Bt_BB", (PetscObject *)&fetidpmat_ctx->Bt_BB));
211     PetscCheck(fetidpmat_ctx->Bt_BB, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Bt_BB not present");
212     PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->Bt_BB));
213 
214     PetscCall(PetscObjectQuery((PetscObject)fetidpmat_ctx->pc, "__KSPFETIDP_flip", (PetscObject *)&fetidpmat_ctx->rhs_flip));
215     if (fetidpmat_ctx->rhs_flip) PetscCall(PetscObjectReference((PetscObject)fetidpmat_ctx->rhs_flip));
216   }
217 
218   /* Default type of lagrange multipliers is non-redundant */
219   fully_redundant = fetidpmat_ctx->fully_redundant;
220 
221   /* Evaluate local and global number of lagrange multipliers */
222   PetscCall(VecSet(pcis->vec1_N, 0.0));
223   n_local_lambda  = 0;
224   partial_sum     = 0;
225   n_boundary_dofs = 0;
226   s               = 0;
227 
228   /* Get Vertices used to define the BDDC */
229   PetscCall(PCBDDCGraphGetCandidatesIS(pcbddc->mat_graph, NULL, NULL, NULL, NULL, &isvert));
230   PetscCall(ISGetLocalSize(isvert, &n_vertices));
231   PetscCall(ISGetIndices(isvert, &vertex_indices));
232 
233   dual_size = pcis->n_B - n_vertices;
234   PetscCall(PetscMalloc1(dual_size, &dual_dofs_boundary_indices));
235   PetscCall(PetscMalloc1(dual_size, &aux_local_numbering_1));
236   PetscCall(PetscMalloc1(dual_size, &aux_local_numbering_2));
237 
238   PetscCall(VecGetArray(pcis->vec1_N, &array));
239   for (i = 0; i < pcis->n; i++) {
240     j = mat_graph->count[i]; /* RECALL: mat_graph->count[i] does not count myself */
241     if (j > 0) n_boundary_dofs++;
242     skip_node = PETSC_FALSE;
243     if (s < n_vertices && vertex_indices[s] == i) { /* it works for a sorted set of vertices */
244       skip_node = PETSC_TRUE;
245       s++;
246     }
247     if (j < 1) skip_node = PETSC_TRUE;
248     if (mat_graph->special_dof[i] == PCBDDCGRAPH_DIRICHLET_MARK) skip_node = PETSC_TRUE;
249     if (!skip_node) {
250       if (fully_redundant) {
251         /* fully redundant set of lagrange multipliers */
252         n_lambda_for_dof = (j * (j + 1)) / 2;
253       } else {
254         n_lambda_for_dof = j;
255       }
256       n_local_lambda += j;
257       /* needed to evaluate global number of lagrange multipliers */
258       array[i] = (1.0 * n_lambda_for_dof) / (j + 1.0); /* already scaled for the next global sum */
259       /* store some data needed */
260       dual_dofs_boundary_indices[partial_sum] = n_boundary_dofs - 1;
261       aux_local_numbering_1[partial_sum]      = i;
262       aux_local_numbering_2[partial_sum]      = n_lambda_for_dof;
263       partial_sum++;
264     }
265   }
266   PetscCall(VecRestoreArray(pcis->vec1_N, &array));
267   PetscCall(ISRestoreIndices(isvert, &vertex_indices));
268   PetscCall(PCBDDCGraphRestoreCandidatesIS(pcbddc->mat_graph, NULL, NULL, NULL, NULL, &isvert));
269   dual_size = partial_sum;
270 
271   /* compute global ordering of lagrange multipliers and associate l2g map */
272   PetscCall(ISCreateGeneral(comm, partial_sum, aux_local_numbering_1, PETSC_COPY_VALUES, &subset_n));
273   PetscCall(ISLocalToGlobalMappingApplyIS(pcis->mapping, subset_n, &subset));
274   PetscCall(ISDestroy(&subset_n));
275   PetscCall(ISCreateGeneral(comm, partial_sum, aux_local_numbering_2, PETSC_OWN_POINTER, &subset_mult));
276   PetscCall(ISRenumber(subset, subset_mult, &fetidpmat_ctx->n_lambda, &subset_n));
277   PetscCall(ISDestroy(&subset));
278 
279   if (PetscDefined(USE_DEBUG)) {
280     PetscCall(VecSet(pcis->vec1_global, 0.0));
281     PetscCall(VecScatterBegin(matis->rctx, pcis->vec1_N, pcis->vec1_global, ADD_VALUES, SCATTER_REVERSE));
282     PetscCall(VecScatterEnd(matis->rctx, pcis->vec1_N, pcis->vec1_global, ADD_VALUES, SCATTER_REVERSE));
283     PetscCall(VecSum(pcis->vec1_global, &scalar_value));
284     i = (PetscInt)PetscRealPart(scalar_value);
285     PetscCheck(i == fetidpmat_ctx->n_lambda, PETSC_COMM_WORLD, PETSC_ERR_PLIB, "Global number of multipliers mismatch! (%" PetscInt_FMT " != %" PetscInt_FMT ")", fetidpmat_ctx->n_lambda, i);
286   }
287 
288   /* init data for scaling factors exchange */
289   if (!pcbddc->use_deluxe_scaling) {
290     PetscInt    *ptrs_buffer, neigh_position;
291     PetscScalar *send_buffer, *recv_buffer;
292     MPI_Request *send_reqs, *recv_reqs;
293 
294     partial_sum = 0;
295     PetscCall(PetscMalloc1(pcis->n_neigh, &ptrs_buffer));
296     PetscCall(PetscMalloc1(PetscMax(pcis->n_neigh - 1, 0), &send_reqs));
297     PetscCall(PetscMalloc1(PetscMax(pcis->n_neigh - 1, 0), &recv_reqs));
298     PetscCall(PetscMalloc1(pcis->n + 1, &all_factors));
299     if (pcis->n_neigh > 0) ptrs_buffer[0] = 0;
300     for (i = 1; i < pcis->n_neigh; i++) {
301       partial_sum += pcis->n_shared[i];
302       ptrs_buffer[i] = ptrs_buffer[i - 1] + pcis->n_shared[i];
303     }
304     PetscCall(PetscMalloc1(partial_sum, &send_buffer));
305     PetscCall(PetscMalloc1(partial_sum, &recv_buffer));
306     PetscCall(PetscMalloc1(partial_sum, &all_factors[0]));
307     for (i = 0; i < pcis->n - 1; i++) {
308       j                  = mat_graph->count[i];
309       all_factors[i + 1] = all_factors[i] + j;
310     }
311 
312     /* scatter B scaling to N vec */
313     PetscCall(VecScatterBegin(pcis->N_to_B, pcis->D, pcis->vec1_N, INSERT_VALUES, SCATTER_REVERSE));
314     PetscCall(VecScatterEnd(pcis->N_to_B, pcis->D, pcis->vec1_N, INSERT_VALUES, SCATTER_REVERSE));
315     /* communications */
316     PetscCall(VecGetArrayRead(pcis->vec1_N, (const PetscScalar **)&array));
317     for (i = 1; i < pcis->n_neigh; i++) {
318       for (j = 0; j < pcis->n_shared[i]; j++) send_buffer[ptrs_buffer[i - 1] + j] = array[pcis->shared[i][j]];
319       PetscCall(PetscMPIIntCast(ptrs_buffer[i] - ptrs_buffer[i - 1], &buf_size));
320       PetscCall(PetscMPIIntCast(pcis->neigh[i], &neigh));
321       PetscCallMPI(MPI_Isend(&send_buffer[ptrs_buffer[i - 1]], buf_size, MPIU_SCALAR, neigh, 0, comm, &send_reqs[i - 1]));
322       PetscCallMPI(MPI_Irecv(&recv_buffer[ptrs_buffer[i - 1]], buf_size, MPIU_SCALAR, neigh, 0, comm, &recv_reqs[i - 1]));
323     }
324     PetscCall(VecRestoreArrayRead(pcis->vec1_N, (const PetscScalar **)&array));
325     if (pcis->n_neigh > 0) PetscCallMPI(MPI_Waitall(pcis->n_neigh - 1, recv_reqs, MPI_STATUSES_IGNORE));
326     /* put values in correct places */
327     for (i = 1; i < pcis->n_neigh; i++) {
328       for (j = 0; j < pcis->n_shared[i]; j++) {
329         k              = pcis->shared[i][j];
330         neigh_position = 0;
331         while (mat_graph->neighbours_set[k][neigh_position] != pcis->neigh[i]) neigh_position++;
332         all_factors[k][neigh_position] = recv_buffer[ptrs_buffer[i - 1] + j];
333       }
334     }
335     if (pcis->n_neigh > 0) PetscCallMPI(MPI_Waitall(pcis->n_neigh - 1, send_reqs, MPI_STATUSES_IGNORE));
336     PetscCall(PetscFree(send_reqs));
337     PetscCall(PetscFree(recv_reqs));
338     PetscCall(PetscFree(send_buffer));
339     PetscCall(PetscFree(recv_buffer));
340     PetscCall(PetscFree(ptrs_buffer));
341   }
342 
343   /* Compute B and B_delta (local actions) */
344   PetscCall(PetscMalloc1(pcis->n_neigh, &aux_sums));
345   PetscCall(PetscMalloc1(n_local_lambda, &l2g_indices));
346   PetscCall(PetscMalloc1(n_local_lambda, &vals_B_delta));
347   PetscCall(PetscMalloc1(n_local_lambda, &cols_B_delta));
348   if (!pcbddc->use_deluxe_scaling) {
349     PetscCall(PetscMalloc1(n_local_lambda, &scaling_factors));
350   } else {
351     scaling_factors = NULL;
352     all_factors     = NULL;
353   }
354   PetscCall(ISGetIndices(subset_n, &aux_global_numbering));
355   partial_sum = 0;
356   cum         = 0;
357   for (i = 0; i < dual_size; i++) {
358     n_global_lambda = aux_global_numbering[cum];
359     j               = mat_graph->count[aux_local_numbering_1[i]];
360     aux_sums[0]     = 0;
361     for (s = 1; s < j; s++) aux_sums[s] = aux_sums[s - 1] + j - s + 1;
362     if (all_factors) array = all_factors[aux_local_numbering_1[i]];
363     n_neg_values = 0;
364     while (n_neg_values < j && mat_graph->neighbours_set[aux_local_numbering_1[i]][n_neg_values] < rank) n_neg_values++;
365     n_pos_values = j - n_neg_values;
366     if (fully_redundant) {
367       for (s = 0; s < n_neg_values; s++) {
368         l2g_indices[partial_sum + s]  = aux_sums[s] + n_neg_values - s - 1 + n_global_lambda;
369         cols_B_delta[partial_sum + s] = dual_dofs_boundary_indices[i];
370         vals_B_delta[partial_sum + s] = -1.0;
371         if (!pcbddc->use_deluxe_scaling) scaling_factors[partial_sum + s] = array[s];
372       }
373       for (s = 0; s < n_pos_values; s++) {
374         l2g_indices[partial_sum + s + n_neg_values]  = aux_sums[n_neg_values] + s + n_global_lambda;
375         cols_B_delta[partial_sum + s + n_neg_values] = dual_dofs_boundary_indices[i];
376         vals_B_delta[partial_sum + s + n_neg_values] = 1.0;
377         if (!pcbddc->use_deluxe_scaling) scaling_factors[partial_sum + s + n_neg_values] = array[s + n_neg_values];
378       }
379       partial_sum += j;
380     } else {
381       /* l2g_indices and default cols and vals of B_delta */
382       for (s = 0; s < j; s++) {
383         l2g_indices[partial_sum + s]  = n_global_lambda + s;
384         cols_B_delta[partial_sum + s] = dual_dofs_boundary_indices[i];
385         vals_B_delta[partial_sum + s] = 0.0;
386       }
387       /* B_delta */
388       if (n_neg_values > 0) { /* there's a rank next to me to the left */
389         vals_B_delta[partial_sum + n_neg_values - 1] = -1.0;
390       }
391       if (n_neg_values < j) { /* there's a rank next to me to the right */
392         vals_B_delta[partial_sum + n_neg_values] = 1.0;
393       }
394       /* scaling as in Klawonn-Widlund 1999 */
395       if (!pcbddc->use_deluxe_scaling) {
396         for (s = 0; s < n_neg_values; s++) {
397           scalar_value = 0.0;
398           for (k = 0; k < s + 1; k++) scalar_value += array[k];
399           scaling_factors[partial_sum + s] = -scalar_value;
400         }
401         for (s = 0; s < n_pos_values; s++) {
402           scalar_value = 0.0;
403           for (k = s + n_neg_values; k < j; k++) scalar_value += array[k];
404           scaling_factors[partial_sum + s + n_neg_values] = scalar_value;
405         }
406       }
407       partial_sum += j;
408     }
409     cum += aux_local_numbering_2[i];
410   }
411   PetscCall(ISRestoreIndices(subset_n, &aux_global_numbering));
412   PetscCall(ISDestroy(&subset_mult));
413   PetscCall(ISDestroy(&subset_n));
414   PetscCall(PetscFree(aux_sums));
415   PetscCall(PetscFree(aux_local_numbering_1));
416   PetscCall(PetscFree(dual_dofs_boundary_indices));
417   if (all_factors) {
418     PetscCall(PetscFree(all_factors[0]));
419     PetscCall(PetscFree(all_factors));
420   }
421 
422   /* Create local part of B_delta */
423   PetscCall(MatCreate(PETSC_COMM_SELF, &fetidpmat_ctx->B_delta));
424   PetscCall(MatSetSizes(fetidpmat_ctx->B_delta, n_local_lambda, pcis->n_B, n_local_lambda, pcis->n_B));
425   PetscCall(MatSetType(fetidpmat_ctx->B_delta, MATSEQAIJ));
426   PetscCall(MatSeqAIJSetPreallocation(fetidpmat_ctx->B_delta, 1, NULL));
427   PetscCall(MatSetOption(fetidpmat_ctx->B_delta, MAT_IGNORE_ZERO_ENTRIES, PETSC_TRUE));
428   for (i = 0; i < n_local_lambda; i++) PetscCall(MatSetValue(fetidpmat_ctx->B_delta, i, cols_B_delta[i], vals_B_delta[i], INSERT_VALUES));
429   PetscCall(PetscFree(vals_B_delta));
430   PetscCall(MatAssemblyBegin(fetidpmat_ctx->B_delta, MAT_FINAL_ASSEMBLY));
431   PetscCall(MatAssemblyEnd(fetidpmat_ctx->B_delta, MAT_FINAL_ASSEMBLY));
432 
433   BD1 = NULL;
434   BD2 = NULL;
435   if (fully_redundant) {
436     PetscCheck(!pcbddc->use_deluxe_scaling, comm, PETSC_ERR_SUP, "Deluxe FETIDP with fully-redundant multipliers to be implemented");
437     PetscCall(MatCreate(PETSC_COMM_SELF, &ScalingMat));
438     PetscCall(MatSetSizes(ScalingMat, n_local_lambda, n_local_lambda, n_local_lambda, n_local_lambda));
439     PetscCall(MatSetType(ScalingMat, MATSEQAIJ));
440     PetscCall(MatSeqAIJSetPreallocation(ScalingMat, 1, NULL));
441     for (i = 0; i < n_local_lambda; i++) PetscCall(MatSetValue(ScalingMat, i, i, scaling_factors[i], INSERT_VALUES));
442     PetscCall(MatAssemblyBegin(ScalingMat, MAT_FINAL_ASSEMBLY));
443     PetscCall(MatAssemblyEnd(ScalingMat, MAT_FINAL_ASSEMBLY));
444     PetscCall(MatMatMult(ScalingMat, fetidpmat_ctx->B_delta, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &fetidpmat_ctx->B_Ddelta));
445     PetscCall(MatDestroy(&ScalingMat));
446   } else {
447     PetscCall(MatCreate(PETSC_COMM_SELF, &fetidpmat_ctx->B_Ddelta));
448     PetscCall(MatSetSizes(fetidpmat_ctx->B_Ddelta, n_local_lambda, pcis->n_B, n_local_lambda, pcis->n_B));
449     if (!pcbddc->use_deluxe_scaling || !pcbddc->sub_schurs) {
450       PetscCall(MatSetType(fetidpmat_ctx->B_Ddelta, MATSEQAIJ));
451       PetscCall(MatSeqAIJSetPreallocation(fetidpmat_ctx->B_Ddelta, 1, NULL));
452       for (i = 0; i < n_local_lambda; i++) PetscCall(MatSetValue(fetidpmat_ctx->B_Ddelta, i, cols_B_delta[i], scaling_factors[i], INSERT_VALUES));
453       PetscCall(MatAssemblyBegin(fetidpmat_ctx->B_Ddelta, MAT_FINAL_ASSEMBLY));
454       PetscCall(MatAssemblyEnd(fetidpmat_ctx->B_Ddelta, MAT_FINAL_ASSEMBLY));
455     } else {
456       /* scaling as in Klawonn-Widlund 1999 */
457       PCBDDCDeluxeScaling deluxe_ctx = pcbddc->deluxe_ctx;
458       PCBDDCSubSchurs     sub_schurs = pcbddc->sub_schurs;
459       Mat                 T;
460       PetscScalar        *W, lwork, *Bwork;
461       const PetscInt     *idxs = NULL;
462       PetscInt            cum, mss, *nnz;
463       PetscBLASInt       *pivots, B_lwork, B_N, B_ierr;
464 
465       PetscCheck(pcbddc->deluxe_singlemat, comm, PETSC_ERR_USER, "Cannot compute B_Ddelta! rerun with -pc_bddc_deluxe_singlemat");
466       mss = 0;
467       PetscCall(PetscCalloc1(pcis->n_B, &nnz));
468       if (sub_schurs->is_Ej_all) {
469         PetscCall(ISGetIndices(sub_schurs->is_Ej_all, &idxs));
470         for (i = 0, cum = 0; i < sub_schurs->n_subs; i++) {
471           PetscInt subset_size;
472 
473           PetscCall(ISGetLocalSize(sub_schurs->is_subs[i], &subset_size));
474           for (j = 0; j < subset_size; j++) nnz[idxs[j + cum]] = subset_size;
475           mss = PetscMax(mss, subset_size);
476           cum += subset_size;
477         }
478       }
479       PetscCall(MatCreate(PETSC_COMM_SELF, &T));
480       PetscCall(MatSetSizes(T, pcis->n_B, pcis->n_B, pcis->n_B, pcis->n_B));
481       PetscCall(MatSetType(T, MATSEQAIJ));
482       PetscCall(MatSeqAIJSetPreallocation(T, 0, nnz));
483       PetscCall(PetscFree(nnz));
484 
485       /* workspace allocation */
486       B_lwork = 0;
487       if (mss) {
488         PetscScalar dummy = 1;
489 
490         B_lwork = -1;
491         PetscCall(PetscBLASIntCast(mss, &B_N));
492         PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
493         PetscCallBLAS("LAPACKgetri", LAPACKgetri_(&B_N, &dummy, &B_N, &B_N, &lwork, &B_lwork, &B_ierr));
494         PetscCall(PetscFPTrapPop());
495         PetscCheck(!B_ierr, PETSC_COMM_SELF, PETSC_ERR_LIB, "Error in query to GETRI Lapack routine %d", (int)B_ierr);
496         PetscCall(PetscBLASIntCast((PetscInt)PetscRealPart(lwork), &B_lwork));
497       }
498       PetscCall(PetscMalloc3(mss * mss, &W, mss, &pivots, B_lwork, &Bwork));
499 
500       for (i = 0, cum = 0; i < sub_schurs->n_subs; i++) {
501         const PetscScalar *M;
502         PetscInt           subset_size;
503 
504         PetscCall(ISGetLocalSize(sub_schurs->is_subs[i], &subset_size));
505         PetscCall(PetscBLASIntCast(subset_size, &B_N));
506         PetscCall(MatDenseGetArrayRead(deluxe_ctx->seq_mat[i], &M));
507         PetscCall(PetscArraycpy(W, M, subset_size * subset_size));
508         PetscCall(MatDenseRestoreArrayRead(deluxe_ctx->seq_mat[i], &M));
509         PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
510         PetscCallBLAS("LAPACKgetrf", LAPACKgetrf_(&B_N, &B_N, W, &B_N, pivots, &B_ierr));
511         PetscCheck(!B_ierr, PETSC_COMM_SELF, PETSC_ERR_LIB, "Error in GETRF Lapack routine %d", (int)B_ierr);
512         PetscCallBLAS("LAPACKgetri", LAPACKgetri_(&B_N, W, &B_N, pivots, Bwork, &B_lwork, &B_ierr));
513         PetscCheck(!B_ierr, PETSC_COMM_SELF, PETSC_ERR_LIB, "Error in GETRI Lapack routine %d", (int)B_ierr);
514         PetscCall(PetscFPTrapPop());
515         /* silent static analyzer */
516         PetscCheck(idxs, PETSC_COMM_SELF, PETSC_ERR_PLIB, "IDXS not present");
517         PetscCall(MatSetValues(T, subset_size, idxs + cum, subset_size, idxs + cum, W, INSERT_VALUES));
518         cum += subset_size;
519       }
520       PetscCall(MatAssemblyBegin(T, MAT_FINAL_ASSEMBLY));
521       PetscCall(MatAssemblyEnd(T, MAT_FINAL_ASSEMBLY));
522       PetscCall(MatMatTransposeMult(T, fetidpmat_ctx->B_delta, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &BD1));
523       PetscCall(MatMatMult(fetidpmat_ctx->B_delta, BD1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &BD2));
524       PetscCall(MatDestroy(&T));
525       PetscCall(PetscFree3(W, pivots, Bwork));
526       if (sub_schurs->is_Ej_all) PetscCall(ISRestoreIndices(sub_schurs->is_Ej_all, &idxs));
527     }
528   }
529   PetscCall(PetscFree(scaling_factors));
530   PetscCall(PetscFree(cols_B_delta));
531 
532   /* Layout of multipliers */
533   PetscCall(PetscLayoutCreate(comm, &llay));
534   PetscCall(PetscLayoutSetBlockSize(llay, 1));
535   PetscCall(PetscLayoutSetSize(llay, fetidpmat_ctx->n_lambda));
536   PetscCall(PetscLayoutSetUp(llay));
537   PetscCall(PetscLayoutGetLocalSize(llay, &fetidpmat_ctx->n));
538 
539   /* Local work vector of multipliers */
540   PetscCall(VecCreate(PETSC_COMM_SELF, &fetidpmat_ctx->lambda_local));
541   PetscCall(VecSetSizes(fetidpmat_ctx->lambda_local, n_local_lambda, n_local_lambda));
542   PetscCall(VecSetType(fetidpmat_ctx->lambda_local, VECSEQ));
543 
544   if (BD2) {
545     ISLocalToGlobalMapping l2g;
546     Mat                    T, TA, *pT;
547     IS                     is;
548     PetscInt               nl, N;
549     BDdelta_DN             ctx;
550 
551     PetscCall(PetscLayoutGetLocalSize(llay, &nl));
552     PetscCall(PetscLayoutGetSize(llay, &N));
553     PetscCall(MatCreate(comm, &T));
554     PetscCall(MatSetSizes(T, nl, nl, N, N));
555     PetscCall(MatSetType(T, MATIS));
556     PetscCall(ISLocalToGlobalMappingCreate(comm, 1, n_local_lambda, l2g_indices, PETSC_COPY_VALUES, &l2g));
557     PetscCall(MatSetLocalToGlobalMapping(T, l2g, l2g));
558     PetscCall(ISLocalToGlobalMappingDestroy(&l2g));
559     PetscCall(MatISSetLocalMat(T, BD2));
560     PetscCall(MatAssemblyBegin(T, MAT_FINAL_ASSEMBLY));
561     PetscCall(MatAssemblyEnd(T, MAT_FINAL_ASSEMBLY));
562     PetscCall(MatDestroy(&BD2));
563     PetscCall(MatConvert(T, MATAIJ, MAT_INITIAL_MATRIX, &TA));
564     PetscCall(MatDestroy(&T));
565     PetscCall(ISCreateGeneral(comm, n_local_lambda, l2g_indices, PETSC_USE_POINTER, &is));
566     PetscCall(MatCreateSubMatrices(TA, 1, &is, &is, MAT_INITIAL_MATRIX, &pT));
567     PetscCall(MatDestroy(&TA));
568     PetscCall(ISDestroy(&is));
569     BD2 = pT[0];
570     PetscCall(PetscFree(pT));
571 
572     /* B_Ddelta for non-redundant multipliers with deluxe scaling */
573     PetscCall(PetscNew(&ctx));
574     PetscCall(MatSetType(fetidpmat_ctx->B_Ddelta, MATSHELL));
575     PetscCall(MatShellSetContext(fetidpmat_ctx->B_Ddelta, ctx));
576     PetscCall(MatShellSetOperation(fetidpmat_ctx->B_Ddelta, MATOP_MULT, (void (*)(void))MatMult_BDdelta_deluxe_nonred));
577     PetscCall(MatShellSetOperation(fetidpmat_ctx->B_Ddelta, MATOP_MULT_TRANSPOSE, (void (*)(void))MatMultTranspose_BDdelta_deluxe_nonred));
578     PetscCall(MatShellSetOperation(fetidpmat_ctx->B_Ddelta, MATOP_DESTROY, (void (*)(void))MatDestroy_BDdelta_deluxe_nonred));
579     PetscCall(MatSetUp(fetidpmat_ctx->B_Ddelta));
580 
581     PetscCall(PetscObjectReference((PetscObject)BD1));
582     ctx->BD = BD1;
583     PetscCall(KSPCreate(PETSC_COMM_SELF, &ctx->kBD));
584     PetscCall(KSPSetOperators(ctx->kBD, BD2, BD2));
585     PetscCall(VecDuplicate(fetidpmat_ctx->lambda_local, &ctx->work));
586     fetidpmat_ctx->deluxe_nonred = PETSC_TRUE;
587   }
588   PetscCall(MatDestroy(&BD1));
589   PetscCall(MatDestroy(&BD2));
590 
591   /* fetidpmat sizes */
592   fetidpmat_ctx->n += nPgl;
593   fetidpmat_ctx->N = fetidpmat_ctx->n_lambda + nPg;
594 
595   /* Global vector for FETI-DP linear system */
596   PetscCall(VecCreate(comm, &fetidp_global));
597   PetscCall(VecSetSizes(fetidp_global, fetidpmat_ctx->n, fetidpmat_ctx->N));
598   PetscCall(VecSetType(fetidp_global, VECMPI));
599   PetscCall(VecSetUp(fetidp_global));
600 
601   /* Decide layout for fetidp dofs: if it is a saddle point problem
602      pressure is ordered first in the local part of the global vector
603      of the FETI-DP linear system */
604   if (nPg) {
605     Vec             v;
606     IS              IS_l2g_p, ais;
607     PetscLayout     alay;
608     const PetscInt *idxs, *pranges, *aranges, *lranges;
609     PetscInt       *l2g_indices_p, rst;
610     PetscMPIInt     rank;
611 
612     PetscCall(PetscMalloc1(nPl, &l2g_indices_p));
613     PetscCall(VecGetLayout(fetidp_global, &alay));
614     PetscCall(PetscLayoutGetRanges(alay, &aranges));
615     PetscCall(PetscLayoutGetRanges(play, &pranges));
616     PetscCall(PetscLayoutGetRanges(llay, &lranges));
617 
618     PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)fetidp_global), &rank));
619     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)fetidp_global), pranges[rank + 1] - pranges[rank], aranges[rank], 1, &fetidpmat_ctx->pressure));
620     PetscCall(PetscObjectSetName((PetscObject)fetidpmat_ctx->pressure, "F_P"));
621     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)fetidp_global), lranges[rank + 1] - lranges[rank], aranges[rank] + pranges[rank + 1] - pranges[rank], 1, &fetidpmat_ctx->lagrange));
622     PetscCall(PetscObjectSetName((PetscObject)fetidpmat_ctx->lagrange, "F_L"));
623     PetscCall(ISLocalToGlobalMappingGetIndices(l2gmap_p, &idxs));
624     /* shift local to global indices for pressure */
625     for (i = 0; i < nPl; i++) {
626       PetscMPIInt owner;
627 
628       PetscCall(PetscLayoutFindOwner(play, idxs[i], &owner));
629       l2g_indices_p[i] = idxs[i] - pranges[owner] + aranges[owner];
630     }
631     PetscCall(ISLocalToGlobalMappingRestoreIndices(l2gmap_p, &idxs));
632     PetscCall(ISCreateGeneral(comm, nPl, l2g_indices_p, PETSC_OWN_POINTER, &IS_l2g_p));
633 
634     /* local to global scatter for pressure */
635     PetscCall(VecScatterCreate(fetidpmat_ctx->vP, NULL, fetidp_global, IS_l2g_p, &fetidpmat_ctx->l2g_p));
636     PetscCall(ISDestroy(&IS_l2g_p));
637 
638     /* scatter for lagrange multipliers only */
639     PetscCall(VecCreate(comm, &v));
640     PetscCall(VecSetType(v, VECSTANDARD));
641     PetscCall(VecSetLayout(v, llay));
642     PetscCall(VecSetUp(v));
643     PetscCall(ISCreateGeneral(comm, n_local_lambda, l2g_indices, PETSC_COPY_VALUES, &ais));
644     PetscCall(VecScatterCreate(fetidpmat_ctx->lambda_local, NULL, v, ais, &fetidpmat_ctx->l2g_lambda_only));
645     PetscCall(ISDestroy(&ais));
646     PetscCall(VecDestroy(&v));
647 
648     /* shift local to global indices for multipliers */
649     for (i = 0; i < n_local_lambda; i++) {
650       PetscInt    ps;
651       PetscMPIInt owner;
652 
653       PetscCall(PetscLayoutFindOwner(llay, l2g_indices[i], &owner));
654       ps             = pranges[owner + 1] - pranges[owner];
655       l2g_indices[i] = l2g_indices[i] - lranges[owner] + aranges[owner] + ps;
656     }
657 
658     /* scatter from alldofs to pressures global fetidp vector */
659     PetscCall(PetscLayoutGetRange(alay, &rst, NULL));
660     PetscCall(ISCreateStride(comm, nPgl, rst, 1, &ais));
661     PetscCall(VecScatterCreate(pcis->vec1_global, pP, fetidp_global, ais, &fetidpmat_ctx->g2g_p));
662     PetscCall(ISDestroy(&ais));
663   }
664   PetscCall(PetscLayoutDestroy(&llay));
665   PetscCall(PetscLayoutDestroy(&play));
666   PetscCall(ISCreateGeneral(comm, n_local_lambda, l2g_indices, PETSC_OWN_POINTER, &IS_l2g_lambda));
667 
668   /* scatter from local to global multipliers */
669   PetscCall(VecScatterCreate(fetidpmat_ctx->lambda_local, NULL, fetidp_global, IS_l2g_lambda, &fetidpmat_ctx->l2g_lambda));
670   PetscCall(ISDestroy(&IS_l2g_lambda));
671   PetscCall(ISLocalToGlobalMappingDestroy(&l2gmap_p));
672   PetscCall(VecDestroy(&fetidp_global));
673 
674   /* Create some work vectors needed by fetidp */
675   PetscCall(VecDuplicate(pcis->vec1_B, &fetidpmat_ctx->temp_solution_B));
676   PetscCall(VecDuplicate(pcis->vec1_D, &fetidpmat_ctx->temp_solution_D));
677   PetscFunctionReturn(PETSC_SUCCESS);
678 }
679 
680 PetscErrorCode PCBDDCSetupFETIDPPCContext(Mat fetimat, FETIDPPC_ctx fetidppc_ctx)
681 {
682   FETIDPMat_ctx mat_ctx;
683   PC_BDDC      *pcbddc = (PC_BDDC *)fetidppc_ctx->pc->data;
684   PC_IS        *pcis   = (PC_IS *)fetidppc_ctx->pc->data;
685   PetscBool     lumped = PETSC_FALSE;
686 
687   PetscFunctionBegin;
688   PetscCall(MatShellGetContext(fetimat, &mat_ctx));
689   /* get references from objects created when setting up feti mat context */
690   PetscCall(PetscObjectReference((PetscObject)mat_ctx->lambda_local));
691   fetidppc_ctx->lambda_local = mat_ctx->lambda_local;
692   PetscCall(PetscObjectReference((PetscObject)mat_ctx->B_Ddelta));
693   fetidppc_ctx->B_Ddelta = mat_ctx->B_Ddelta;
694   if (mat_ctx->deluxe_nonred) {
695     PC            pc, mpc;
696     BDdelta_DN    ctx;
697     MatSolverType solver;
698     const char   *prefix;
699 
700     PetscCall(MatShellGetContext(mat_ctx->B_Ddelta, &ctx));
701     PetscCall(KSPSetType(ctx->kBD, KSPPREONLY));
702     PetscCall(KSPGetPC(ctx->kBD, &mpc));
703     PetscCall(KSPGetPC(pcbddc->ksp_D, &pc));
704     PetscCall(PCSetType(mpc, PCLU));
705     PetscCall(PCFactorGetMatSolverType(pc, (MatSolverType *)&solver));
706     if (solver) PetscCall(PCFactorSetMatSolverType(mpc, solver));
707     PetscCall(MatGetOptionsPrefix(fetimat, &prefix));
708     PetscCall(KSPSetOptionsPrefix(ctx->kBD, prefix));
709     PetscCall(KSPAppendOptionsPrefix(ctx->kBD, "bddelta_"));
710     PetscCall(KSPSetFromOptions(ctx->kBD));
711   }
712 
713   if (mat_ctx->l2g_lambda_only) {
714     PetscCall(PetscObjectReference((PetscObject)mat_ctx->l2g_lambda_only));
715     fetidppc_ctx->l2g_lambda = mat_ctx->l2g_lambda_only;
716   } else {
717     PetscCall(PetscObjectReference((PetscObject)mat_ctx->l2g_lambda));
718     fetidppc_ctx->l2g_lambda = mat_ctx->l2g_lambda;
719   }
720   /* Dirichlet preconditioner */
721   PetscCall(PetscOptionsGetBool(NULL, ((PetscObject)fetimat)->prefix, "-pc_lumped", &lumped, NULL));
722   if (!lumped) {
723     IS        iV;
724     PetscBool discrete_harmonic = PETSC_FALSE;
725 
726     PetscCall(PetscObjectQuery((PetscObject)fetidppc_ctx->pc, "__KSPFETIDP_iV", (PetscObject *)&iV));
727     if (iV) PetscCall(PetscOptionsGetBool(NULL, ((PetscObject)fetimat)->prefix, "-pc_discrete_harmonic", &discrete_harmonic, NULL));
728     if (discrete_harmonic) {
729       KSP             sksp;
730       PC              pc;
731       PCBDDCSubSchurs sub_schurs = pcbddc->sub_schurs;
732       Mat             A_II, A_IB, A_BI;
733       IS              iP = NULL;
734       PetscBool       isshell, reuse = PETSC_FALSE;
735       KSPType         ksptype;
736       const char     *prefix;
737 
738       /*
739         We constructs a Schur complement for
740 
741         | A_II A_ID |
742         | A_DI A_DD |
743 
744         instead of
745 
746         | A_II  B^t_II A_ID |
747         | B_II -C_II   B_ID |
748         | A_DI  B^t_ID A_DD |
749 
750       */
751       if (sub_schurs && sub_schurs->reuse_solver) {
752         PetscCall(PetscObjectQuery((PetscObject)sub_schurs->A, "__KSPFETIDP_iP", (PetscObject *)&iP));
753         if (iP) reuse = PETSC_TRUE;
754       }
755       if (!reuse) {
756         IS       aB;
757         PetscInt nb;
758         PetscCall(ISGetLocalSize(pcis->is_B_local, &nb));
759         PetscCall(ISCreateStride(PetscObjectComm((PetscObject)pcis->A_II), nb, 0, 1, &aB));
760         PetscCall(MatCreateSubMatrix(pcis->A_II, iV, iV, MAT_INITIAL_MATRIX, &A_II));
761         PetscCall(MatCreateSubMatrix(pcis->A_IB, iV, aB, MAT_INITIAL_MATRIX, &A_IB));
762         PetscCall(MatCreateSubMatrix(pcis->A_BI, aB, iV, MAT_INITIAL_MATRIX, &A_BI));
763         PetscCall(ISDestroy(&aB));
764       } else {
765         PetscCall(MatCreateSubMatrix(sub_schurs->A, pcis->is_I_local, pcis->is_B_local, MAT_INITIAL_MATRIX, &A_IB));
766         PetscCall(MatCreateSubMatrix(sub_schurs->A, pcis->is_B_local, pcis->is_I_local, MAT_INITIAL_MATRIX, &A_BI));
767         PetscCall(PetscObjectReference((PetscObject)pcis->A_II));
768         A_II = pcis->A_II;
769       }
770       PetscCall(MatCreateSchurComplement(A_II, A_II, A_IB, A_BI, pcis->A_BB, &fetidppc_ctx->S_j));
771 
772       /* propagate settings of solver */
773       PetscCall(MatSchurComplementGetKSP(fetidppc_ctx->S_j, &sksp));
774       PetscCall(KSPGetType(pcis->ksp_D, &ksptype));
775       PetscCall(KSPSetType(sksp, ksptype));
776       PetscCall(KSPGetPC(pcis->ksp_D, &pc));
777       PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCSHELL, &isshell));
778       if (!isshell) {
779         MatSolverType solver;
780         PCType        pctype;
781 
782         PetscCall(PCGetType(pc, &pctype));
783         PetscCall(PCFactorGetMatSolverType(pc, (MatSolverType *)&solver));
784         PetscCall(KSPGetPC(sksp, &pc));
785         PetscCall(PCSetType(pc, pctype));
786         if (solver) PetscCall(PCFactorSetMatSolverType(pc, solver));
787       } else {
788         PetscCall(KSPGetPC(sksp, &pc));
789         PetscCall(PCSetType(pc, PCLU));
790       }
791       PetscCall(MatDestroy(&A_II));
792       PetscCall(MatDestroy(&A_IB));
793       PetscCall(MatDestroy(&A_BI));
794       PetscCall(MatGetOptionsPrefix(fetimat, &prefix));
795       PetscCall(KSPSetOptionsPrefix(sksp, prefix));
796       PetscCall(KSPAppendOptionsPrefix(sksp, "harmonic_"));
797       PetscCall(KSPSetFromOptions(sksp));
798       if (reuse) {
799         PetscCall(KSPSetPC(sksp, sub_schurs->reuse_solver->interior_solver));
800         PetscCall(PetscObjectIncrementTabLevel((PetscObject)sub_schurs->reuse_solver->interior_solver, (PetscObject)sksp, 0));
801       }
802     } else { /* default Dirichlet preconditioner is pde-harmonic */
803       PetscCall(MatCreateSchurComplement(pcis->A_II, pcis->A_II, pcis->A_IB, pcis->A_BI, pcis->A_BB, &fetidppc_ctx->S_j));
804       PetscCall(MatSchurComplementSetKSP(fetidppc_ctx->S_j, pcis->ksp_D));
805     }
806   } else {
807     PetscCall(PetscObjectReference((PetscObject)pcis->A_BB));
808     fetidppc_ctx->S_j = pcis->A_BB;
809   }
810   /* saddle-point */
811   if (mat_ctx->xPg) {
812     PetscCall(PetscObjectReference((PetscObject)mat_ctx->xPg));
813     fetidppc_ctx->xPg = mat_ctx->xPg;
814     PetscCall(PetscObjectReference((PetscObject)mat_ctx->yPg));
815     fetidppc_ctx->yPg = mat_ctx->yPg;
816   }
817   PetscFunctionReturn(PETSC_SUCCESS);
818 }
819 
820 PetscErrorCode FETIDPMatMult_Kernel(Mat fetimat, Vec x, Vec y, PetscBool trans)
821 {
822   FETIDPMat_ctx mat_ctx;
823   PC_BDDC      *pcbddc;
824   PC_IS        *pcis;
825 
826   PetscFunctionBegin;
827   PetscCall(MatShellGetContext(fetimat, &mat_ctx));
828   pcis   = (PC_IS *)mat_ctx->pc->data;
829   pcbddc = (PC_BDDC *)mat_ctx->pc->data;
830   /* Application of B_delta^T */
831   PetscCall(VecSet(pcis->vec1_B, 0.));
832   PetscCall(VecScatterBegin(mat_ctx->l2g_lambda, x, mat_ctx->lambda_local, INSERT_VALUES, SCATTER_REVERSE));
833   PetscCall(VecScatterEnd(mat_ctx->l2g_lambda, x, mat_ctx->lambda_local, INSERT_VALUES, SCATTER_REVERSE));
834   PetscCall(MatMultTranspose(mat_ctx->B_delta, mat_ctx->lambda_local, pcis->vec1_B));
835 
836   /* Add contribution from saddle point */
837   if (mat_ctx->l2g_p) {
838     PetscCall(VecScatterBegin(mat_ctx->l2g_p, x, mat_ctx->vP, INSERT_VALUES, SCATTER_REVERSE));
839     PetscCall(VecScatterEnd(mat_ctx->l2g_p, x, mat_ctx->vP, INSERT_VALUES, SCATTER_REVERSE));
840     if (pcbddc->switch_static) {
841       if (trans) {
842         PetscCall(MatMultTranspose(mat_ctx->B_BI, mat_ctx->vP, pcis->vec1_D));
843       } else {
844         PetscCall(MatMult(mat_ctx->Bt_BI, mat_ctx->vP, pcis->vec1_D));
845       }
846     }
847     if (trans) {
848       PetscCall(MatMultTransposeAdd(mat_ctx->B_BB, mat_ctx->vP, pcis->vec1_B, pcis->vec1_B));
849     } else {
850       PetscCall(MatMultAdd(mat_ctx->Bt_BB, mat_ctx->vP, pcis->vec1_B, pcis->vec1_B));
851     }
852   } else {
853     if (pcbddc->switch_static) PetscCall(VecSet(pcis->vec1_D, 0.0));
854   }
855   /* Application of \widetilde{S}^-1 */
856   PetscCall(PetscArrayzero(pcbddc->benign_p0, pcbddc->benign_n));
857   PetscCall(PCBDDCApplyInterfacePreconditioner(mat_ctx->pc, trans));
858   PetscCall(PetscArrayzero(pcbddc->benign_p0, pcbddc->benign_n));
859   PetscCall(VecSet(y, 0.0));
860   /* Application of B_delta */
861   PetscCall(MatMult(mat_ctx->B_delta, pcis->vec1_B, mat_ctx->lambda_local));
862   /* Contribution from boundary pressures */
863   if (mat_ctx->C) {
864     const PetscScalar *lx;
865     PetscScalar       *ly;
866 
867     /* pressure ordered first in the local part of x and y */
868     PetscCall(VecGetArrayRead(x, &lx));
869     PetscCall(VecGetArray(y, &ly));
870     PetscCall(VecPlaceArray(mat_ctx->xPg, lx));
871     PetscCall(VecPlaceArray(mat_ctx->yPg, ly));
872     if (trans) {
873       PetscCall(MatMultTranspose(mat_ctx->C, mat_ctx->xPg, mat_ctx->yPg));
874     } else {
875       PetscCall(MatMult(mat_ctx->C, mat_ctx->xPg, mat_ctx->yPg));
876     }
877     PetscCall(VecResetArray(mat_ctx->xPg));
878     PetscCall(VecResetArray(mat_ctx->yPg));
879     PetscCall(VecRestoreArrayRead(x, &lx));
880     PetscCall(VecRestoreArray(y, &ly));
881   }
882   /* Add contribution from saddle point */
883   if (mat_ctx->l2g_p) {
884     if (trans) {
885       PetscCall(MatMultTranspose(mat_ctx->Bt_BB, pcis->vec1_B, mat_ctx->vP));
886     } else {
887       PetscCall(MatMult(mat_ctx->B_BB, pcis->vec1_B, mat_ctx->vP));
888     }
889     if (pcbddc->switch_static) {
890       if (trans) {
891         PetscCall(MatMultTransposeAdd(mat_ctx->Bt_BI, pcis->vec1_D, mat_ctx->vP, mat_ctx->vP));
892       } else {
893         PetscCall(MatMultAdd(mat_ctx->B_BI, pcis->vec1_D, mat_ctx->vP, mat_ctx->vP));
894       }
895     }
896     PetscCall(VecScatterBegin(mat_ctx->l2g_p, mat_ctx->vP, y, ADD_VALUES, SCATTER_FORWARD));
897     PetscCall(VecScatterEnd(mat_ctx->l2g_p, mat_ctx->vP, y, ADD_VALUES, SCATTER_FORWARD));
898   }
899   PetscCall(VecScatterBegin(mat_ctx->l2g_lambda, mat_ctx->lambda_local, y, ADD_VALUES, SCATTER_FORWARD));
900   PetscCall(VecScatterEnd(mat_ctx->l2g_lambda, mat_ctx->lambda_local, y, ADD_VALUES, SCATTER_FORWARD));
901   PetscFunctionReturn(PETSC_SUCCESS);
902 }
903 
904 PetscErrorCode FETIDPMatMult(Mat fetimat, Vec x, Vec y)
905 {
906   PetscFunctionBegin;
907   PetscCall(FETIDPMatMult_Kernel(fetimat, x, y, PETSC_FALSE));
908   PetscFunctionReturn(PETSC_SUCCESS);
909 }
910 
911 PetscErrorCode FETIDPMatMultTranspose(Mat fetimat, Vec x, Vec y)
912 {
913   PetscFunctionBegin;
914   PetscCall(FETIDPMatMult_Kernel(fetimat, x, y, PETSC_TRUE));
915   PetscFunctionReturn(PETSC_SUCCESS);
916 }
917 
918 PetscErrorCode FETIDPPCApply_Kernel(PC fetipc, Vec x, Vec y, PetscBool trans)
919 {
920   FETIDPPC_ctx pc_ctx;
921   PC_IS       *pcis;
922 
923   PetscFunctionBegin;
924   PetscCall(PCShellGetContext(fetipc, &pc_ctx));
925   pcis = (PC_IS *)pc_ctx->pc->data;
926   /* Application of B_Ddelta^T */
927   PetscCall(VecScatterBegin(pc_ctx->l2g_lambda, x, pc_ctx->lambda_local, INSERT_VALUES, SCATTER_REVERSE));
928   PetscCall(VecScatterEnd(pc_ctx->l2g_lambda, x, pc_ctx->lambda_local, INSERT_VALUES, SCATTER_REVERSE));
929   PetscCall(VecSet(pcis->vec2_B, 0.0));
930   PetscCall(MatMultTranspose(pc_ctx->B_Ddelta, pc_ctx->lambda_local, pcis->vec2_B));
931   /* Application of local Schur complement */
932   if (trans) {
933     PetscCall(MatMultTranspose(pc_ctx->S_j, pcis->vec2_B, pcis->vec1_B));
934   } else {
935     PetscCall(MatMult(pc_ctx->S_j, pcis->vec2_B, pcis->vec1_B));
936   }
937   /* Application of B_Ddelta */
938   PetscCall(MatMult(pc_ctx->B_Ddelta, pcis->vec1_B, pc_ctx->lambda_local));
939   PetscCall(VecSet(y, 0.0));
940   PetscCall(VecScatterBegin(pc_ctx->l2g_lambda, pc_ctx->lambda_local, y, ADD_VALUES, SCATTER_FORWARD));
941   PetscCall(VecScatterEnd(pc_ctx->l2g_lambda, pc_ctx->lambda_local, y, ADD_VALUES, SCATTER_FORWARD));
942   PetscFunctionReturn(PETSC_SUCCESS);
943 }
944 
945 PetscErrorCode FETIDPPCApply(PC pc, Vec x, Vec y)
946 {
947   PetscFunctionBegin;
948   PetscCall(FETIDPPCApply_Kernel(pc, x, y, PETSC_FALSE));
949   PetscFunctionReturn(PETSC_SUCCESS);
950 }
951 
952 PetscErrorCode FETIDPPCApplyTranspose(PC pc, Vec x, Vec y)
953 {
954   PetscFunctionBegin;
955   PetscCall(FETIDPPCApply_Kernel(pc, x, y, PETSC_TRUE));
956   PetscFunctionReturn(PETSC_SUCCESS);
957 }
958 
959 PetscErrorCode FETIDPPCView(PC pc, PetscViewer viewer)
960 {
961   FETIDPPC_ctx pc_ctx;
962   PetscBool    iascii;
963   PetscViewer  sviewer;
964 
965   PetscFunctionBegin;
966   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
967   if (iascii) {
968     PetscMPIInt rank;
969     PetscBool   isschur, isshell;
970 
971     PetscCall(PCShellGetContext(pc, &pc_ctx));
972     PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
973     PetscCall(PetscObjectTypeCompare((PetscObject)pc_ctx->S_j, MATSCHURCOMPLEMENT, &isschur));
974     if (isschur) {
975       PetscCall(PetscViewerASCIIPrintf(viewer, "  Dirichlet preconditioner (just from rank 0)\n"));
976     } else {
977       PetscCall(PetscViewerASCIIPrintf(viewer, "  Lumped preconditioner (just from rank 0)\n"));
978     }
979     PetscCall(PetscViewerGetSubViewer(viewer, PetscObjectComm((PetscObject)pc_ctx->S_j), &sviewer));
980     if (rank == 0) {
981       PetscCall(PetscViewerPushFormat(sviewer, PETSC_VIEWER_ASCII_INFO));
982       PetscCall(PetscViewerASCIIPushTab(sviewer));
983       PetscCall(MatView(pc_ctx->S_j, sviewer));
984       PetscCall(PetscViewerASCIIPopTab(sviewer));
985       PetscCall(PetscViewerPopFormat(sviewer));
986     }
987     PetscCall(PetscViewerRestoreSubViewer(viewer, PetscObjectComm((PetscObject)pc_ctx->S_j), &sviewer));
988     PetscCall(PetscObjectTypeCompare((PetscObject)pc_ctx->B_Ddelta, MATSHELL, &isshell));
989     if (isshell) {
990       BDdelta_DN ctx;
991       PetscCall(PetscViewerASCIIPrintf(viewer, "  FETI-DP BDdelta: DB^t * (B D^-1 B^t)^-1 for deluxe scaling (just from rank 0)\n"));
992       PetscCall(MatShellGetContext(pc_ctx->B_Ddelta, &ctx));
993       PetscCall(PetscViewerGetSubViewer(viewer, PetscObjectComm((PetscObject)pc_ctx->S_j), &sviewer));
994       if (rank == 0) {
995         PetscInt tl;
996 
997         PetscCall(PetscViewerASCIIGetTab(sviewer, &tl));
998         PetscCall(PetscObjectSetTabLevel((PetscObject)ctx->kBD, tl));
999         PetscCall(KSPView(ctx->kBD, sviewer));
1000         PetscCall(PetscViewerPushFormat(sviewer, PETSC_VIEWER_ASCII_INFO));
1001         PetscCall(MatView(ctx->BD, sviewer));
1002         PetscCall(PetscViewerPopFormat(sviewer));
1003       }
1004       PetscCall(PetscViewerRestoreSubViewer(viewer, PetscObjectComm((PetscObject)pc_ctx->S_j), &sviewer));
1005     }
1006     PetscCall(PetscViewerFlush(viewer));
1007   }
1008   PetscFunctionReturn(PETSC_SUCCESS);
1009 }
1010