xref: /petsc/src/ksp/pc/impls/bddc/bddcschurs.c (revision c62d2063aef73dfc219d2f9fedb4e2e585a20cb3)
1 #include <../src/ksp/pc/impls/bddc/bddc.h>
2 #include <../src/ksp/pc/impls/bddc/bddcprivate.h>
3 #include <petscblaslapack.h>
4 
5 PETSC_STATIC_INLINE PetscErrorCode PCBDDCAdjGetNextLayer_Private(PetscInt*,PetscInt,PetscBT,PetscInt*,PetscInt*,PetscInt*);
6 static PetscErrorCode PCBDDCComputeExplicitSchur(Mat,PetscBool,MatReuse,Mat*);
7 static PetscErrorCode PCBDDCMumpsInteriorSolve(PC,Vec,Vec);
8 static PetscErrorCode PCBDDCMumpsCorrectionSolve(PC,Vec,Vec);
9 
10 #undef __FUNCT__
11 #define __FUNCT__ "PCBDDCMumpsCorrectionSolve_Private"
12 static PetscErrorCode PCBDDCMumpsCorrectionSolve_Private(PC pc, Vec rhs, Vec sol, PetscBool transpose)
13 {
14   PCBDDCReuseMumps ctx;
15   PetscInt         ival;
16   PetscErrorCode   ierr;
17 
18   PetscFunctionBegin;
19   ierr = PCShellGetContext(pc,(void **)&ctx);CHKERRQ(ierr);
20 #if defined(PETSC_HAVE_MUMPS)
21   ierr = MatMumpsGetIcntl(ctx->F,26,&ival);CHKERRQ(ierr);
22   ierr = MatMumpsSetIcntl(ctx->F,26,-1);CHKERRQ(ierr);
23 #endif
24   if (transpose) {
25     ierr = MatSolveTranspose(ctx->F,rhs,sol);CHKERRQ(ierr);
26   } else {
27     ierr = MatSolve(ctx->F,rhs,sol);CHKERRQ(ierr);
28   }
29 #if defined(PETSC_HAVE_MUMPS)
30   ierr = MatMumpsSetIcntl(ctx->F,26,ival);CHKERRQ(ierr);
31 #endif
32   PetscFunctionReturn(0);
33 }
34 
35 #undef __FUNCT__
36 #define __FUNCT__ "PCBDDCMumpsCorrectionSolve"
37 static PetscErrorCode PCBDDCMumpsCorrectionSolve(PC pc, Vec rhs, Vec sol)
38 {
39   PetscErrorCode   ierr;
40 
41   PetscFunctionBegin;
42   ierr = PCBDDCMumpsCorrectionSolve_Private(pc,rhs,sol,PETSC_FALSE);CHKERRQ(ierr);
43   PetscFunctionReturn(0);
44 }
45 
46 #undef __FUNCT__
47 #define __FUNCT__ "PCBDDCMumpsCorrectionSolveTranspose"
48 static PetscErrorCode PCBDDCMumpsCorrectionSolveTranspose(PC pc, Vec rhs, Vec sol)
49 {
50   PetscErrorCode   ierr;
51 
52   PetscFunctionBegin;
53   ierr = PCBDDCMumpsCorrectionSolve_Private(pc,rhs,sol,PETSC_TRUE);CHKERRQ(ierr);
54   PetscFunctionReturn(0);
55 }
56 
57 #undef __FUNCT__
58 #define __FUNCT__ "PCBDDCReuseMumpsReset"
59 static PetscErrorCode PCBDDCReuseMumpsReset(PCBDDCReuseMumps reuse)
60 {
61   PetscErrorCode ierr;
62 
63   PetscFunctionBegin;
64   ierr = MatDestroy(&reuse->F);CHKERRQ(ierr);
65   ierr = VecDestroy(&reuse->sol);CHKERRQ(ierr);
66   ierr = VecDestroy(&reuse->rhs);CHKERRQ(ierr);
67   ierr = PCDestroy(&reuse->interior_solver);CHKERRQ(ierr);
68   ierr = PCDestroy(&reuse->correction_solver);CHKERRQ(ierr);
69   ierr = ISDestroy(&reuse->is_R);CHKERRQ(ierr);
70   ierr = ISDestroy(&reuse->is_B);CHKERRQ(ierr);
71   ierr = VecScatterDestroy(&reuse->correction_scatter_B);CHKERRQ(ierr);
72   ierr = VecDestroy(&reuse->sol_B);CHKERRQ(ierr);
73   ierr = VecDestroy(&reuse->rhs_B);CHKERRQ(ierr);
74   PetscFunctionReturn(0);
75 }
76 
77 #undef __FUNCT__
78 #define __FUNCT__ "PCBDDCMumpsInteriorSolve_Private"
79 static PetscErrorCode PCBDDCMumpsInteriorSolve_Private(PC pc, Vec rhs, Vec sol, PetscBool transpose)
80 {
81   PCBDDCReuseMumps ctx;
82   PetscScalar      *array,*array_mumps;
83   PetscInt         ival;
84   PetscErrorCode   ierr;
85 
86   PetscFunctionBegin;
87   ierr = PCShellGetContext(pc,(void **)&ctx);CHKERRQ(ierr);
88 #if defined(PETSC_HAVE_MUMPS)
89   ierr = MatMumpsGetIcntl(ctx->F,26,&ival);CHKERRQ(ierr);
90   ierr = MatMumpsSetIcntl(ctx->F,26,0);CHKERRQ(ierr);
91 #endif
92   /* copy rhs into factored matrix workspace (can it be avoided?, MatSolve_MUMPS has another copy b->x internally) */
93   ierr = VecGetArrayRead(rhs,(const PetscScalar**)&array);CHKERRQ(ierr);
94   ierr = VecGetArray(ctx->rhs,&array_mumps);CHKERRQ(ierr);
95   ierr = PetscMemcpy(array_mumps,array,ctx->n_I*sizeof(PetscScalar));CHKERRQ(ierr);
96   ierr = VecRestoreArray(ctx->rhs,&array_mumps);CHKERRQ(ierr);
97   ierr = VecRestoreArrayRead(rhs,(const PetscScalar**)&array);CHKERRQ(ierr);
98 
99   if (transpose) {
100     ierr = MatSolveTranspose(ctx->F,ctx->rhs,ctx->sol);CHKERRQ(ierr);
101   } else {
102     ierr = MatSolve(ctx->F,ctx->rhs,ctx->sol);CHKERRQ(ierr);
103   }
104 
105   /* get back data to caller worskpace */
106   ierr = VecGetArrayRead(ctx->sol,(const PetscScalar**)&array_mumps);CHKERRQ(ierr);
107   ierr = VecGetArray(sol,&array);CHKERRQ(ierr);
108   ierr = PetscMemcpy(array,array_mumps,ctx->n_I*sizeof(PetscScalar));CHKERRQ(ierr);
109   ierr = VecRestoreArray(sol,&array);CHKERRQ(ierr);
110   ierr = VecRestoreArrayRead(ctx->sol,(const PetscScalar**)&array_mumps);CHKERRQ(ierr);
111 #if defined(PETSC_HAVE_MUMPS)
112   ierr = MatMumpsSetIcntl(ctx->F,26,ival);CHKERRQ(ierr);
113 #endif
114   PetscFunctionReturn(0);
115 }
116 
117 #undef __FUNCT__
118 #define __FUNCT__ "PCBDDCMumpsInteriorSolve"
119 static PetscErrorCode PCBDDCMumpsInteriorSolve(PC pc, Vec rhs, Vec sol)
120 {
121   PetscErrorCode   ierr;
122 
123   PetscFunctionBegin;
124   ierr = PCBDDCMumpsInteriorSolve_Private(pc,rhs,sol,PETSC_FALSE);CHKERRQ(ierr);
125   PetscFunctionReturn(0);
126 }
127 
128 #undef __FUNCT__
129 #define __FUNCT__ "PCBDDCMumpsInteriorSolveTranspose"
130 static PetscErrorCode PCBDDCMumpsInteriorSolveTranspose(PC pc, Vec rhs, Vec sol)
131 {
132   PetscErrorCode   ierr;
133 
134   PetscFunctionBegin;
135   ierr = PCBDDCMumpsInteriorSolve_Private(pc,rhs,sol,PETSC_TRUE);CHKERRQ(ierr);
136   PetscFunctionReturn(0);
137 }
138 
139 #undef __FUNCT__
140 #define __FUNCT__ "PCBDDCComputeExplicitSchur"
141 static PetscErrorCode PCBDDCComputeExplicitSchur(Mat M, PetscBool issym, MatReuse reuse, Mat *S)
142 {
143   Mat            B, C, D, Bd, Cd, AinvBd;
144   KSP            ksp;
145   PC             pc;
146   PetscBool      isLU, isILU, isCHOL, Bdense, Cdense;
147   PetscReal      fill = 2.0;
148   PetscInt       n_I;
149   PetscMPIInt    size;
150   PetscErrorCode ierr;
151 
152   PetscFunctionBegin;
153   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)M),&size);CHKERRQ(ierr);
154   if (size != 1) {
155     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not for parallel matrices");
156   }
157   if (reuse == MAT_REUSE_MATRIX) {
158     PetscBool Sdense;
159 
160     ierr = PetscObjectTypeCompare((PetscObject)*S, MATSEQDENSE, &Sdense);CHKERRQ(ierr);
161     if (!Sdense) {
162       SETERRQ(PetscObjectComm((PetscObject)M),PETSC_ERR_SUP,"S should dense");
163     }
164   }
165   ierr = MatSchurComplementGetSubMatrices(M, NULL, NULL, &B, &C, &D);CHKERRQ(ierr);
166   ierr = MatSchurComplementGetKSP(M, &ksp);CHKERRQ(ierr);
167   ierr = KSPGetPC(ksp, &pc);CHKERRQ(ierr);
168   ierr = PetscObjectTypeCompare((PetscObject) pc, PCLU, &isLU);CHKERRQ(ierr);
169   ierr = PetscObjectTypeCompare((PetscObject) pc, PCILU, &isILU);CHKERRQ(ierr);
170   ierr = PetscObjectTypeCompare((PetscObject) pc, PCCHOLESKY, &isCHOL);CHKERRQ(ierr);
171   ierr = PetscObjectTypeCompare((PetscObject) B, MATSEQDENSE, &Bdense);CHKERRQ(ierr);
172   ierr = PetscObjectTypeCompare((PetscObject) C, MATSEQDENSE, &Cdense);CHKERRQ(ierr);
173   ierr = MatGetSize(B,&n_I,NULL);CHKERRQ(ierr);
174   if (n_I) {
175     if (!Bdense) {
176       ierr = MatConvert(B, MATSEQDENSE, MAT_INITIAL_MATRIX, &Bd);CHKERRQ(ierr);
177     } else {
178       Bd = B;
179     }
180 
181     if (isLU || isILU || isCHOL) {
182       Mat fact;
183       ierr = KSPSetUp(ksp);CHKERRQ(ierr);
184       ierr = PCFactorGetMatrix(pc, &fact);CHKERRQ(ierr);
185       ierr = MatDuplicate(Bd, MAT_DO_NOT_COPY_VALUES, &AinvBd);CHKERRQ(ierr);
186       ierr = MatMatSolve(fact, Bd, AinvBd);CHKERRQ(ierr);
187     } else {
188       PetscBool ex = PETSC_TRUE;
189 
190       if (ex) {
191         Mat Ainvd;
192 
193         ierr = PCComputeExplicitOperator(pc, &Ainvd);CHKERRQ(ierr);
194         ierr = MatMatMult(Ainvd, Bd, MAT_INITIAL_MATRIX, fill, &AinvBd);CHKERRQ(ierr);
195         ierr = MatDestroy(&Ainvd);CHKERRQ(ierr);
196       } else {
197         Vec         sol,rhs;
198         PetscScalar *arrayrhs,*arraysol;
199         PetscInt    i,nrhs,n;
200 
201         ierr = MatDuplicate(Bd, MAT_DO_NOT_COPY_VALUES, &AinvBd);CHKERRQ(ierr);
202         ierr = MatGetSize(Bd,&n,&nrhs);CHKERRQ(ierr);
203         ierr = MatDenseGetArray(Bd,&arrayrhs);CHKERRQ(ierr);
204         ierr = MatDenseGetArray(AinvBd,&arraysol);CHKERRQ(ierr);
205         ierr = KSPGetSolution(ksp,&sol);CHKERRQ(ierr);
206         ierr = KSPGetRhs(ksp,&rhs);CHKERRQ(ierr);
207         for (i=0;i<nrhs;i++) {
208           ierr = VecPlaceArray(rhs,arrayrhs+i*n);CHKERRQ(ierr);
209           ierr = VecPlaceArray(sol,arraysol+i*n);CHKERRQ(ierr);
210           ierr = KSPSolve(ksp,rhs,sol);CHKERRQ(ierr);
211           ierr = VecResetArray(rhs);CHKERRQ(ierr);
212           ierr = VecResetArray(sol);CHKERRQ(ierr);
213         }
214         ierr = MatDenseRestoreArray(Bd,&arrayrhs);CHKERRQ(ierr);
215         ierr = MatDenseRestoreArray(AinvBd,&arrayrhs);CHKERRQ(ierr);
216       }
217     }
218     if (!Bdense & !issym) {
219       ierr = MatDestroy(&Bd);CHKERRQ(ierr);
220     }
221 
222     if (!issym) {
223       if (!Cdense) {
224         ierr = MatConvert(C, MATSEQDENSE, MAT_INITIAL_MATRIX, &Cd);CHKERRQ(ierr);
225       } else {
226         Cd = C;
227       }
228       ierr = MatMatMult(Cd, AinvBd, reuse, fill, S);CHKERRQ(ierr);
229       if (!Cdense) {
230         ierr = MatDestroy(&Cd);CHKERRQ(ierr);
231       }
232     } else {
233       ierr = MatTransposeMatMult(Bd, AinvBd, reuse, fill, S);CHKERRQ(ierr);
234       if (!Bdense) {
235         ierr = MatDestroy(&Bd);CHKERRQ(ierr);
236       }
237     }
238     ierr = MatDestroy(&AinvBd);CHKERRQ(ierr);
239   }
240 
241   if (D) {
242     Mat       Dd;
243     PetscBool Ddense;
244 
245     ierr = PetscObjectTypeCompare((PetscObject)D,MATSEQDENSE,&Ddense);CHKERRQ(ierr);
246     if (!Ddense) {
247       ierr = MatConvert(D, MATSEQDENSE, MAT_INITIAL_MATRIX, &Dd);CHKERRQ(ierr);
248     } else {
249       Dd = D;
250     }
251     if (n_I) {
252       ierr = MatAYPX(*S,-1.0,Dd,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
253     } else {
254       if (reuse == MAT_INITIAL_MATRIX) {
255         ierr = MatDuplicate(Dd,MAT_COPY_VALUES,S);CHKERRQ(ierr);
256       } else {
257         ierr = MatCopy(Dd,*S,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
258       }
259     }
260     if (!Ddense) {
261       ierr = MatDestroy(&Dd);CHKERRQ(ierr);
262     }
263   } else {
264     ierr = MatScale(*S,-1.0);CHKERRQ(ierr);
265   }
266   PetscFunctionReturn(0);
267 }
268 
269 #undef __FUNCT__
270 #define __FUNCT__ "PCBDDCSubSchursSetUp"
271 PetscErrorCode PCBDDCSubSchursSetUp(PCBDDCSubSchurs sub_schurs, Mat Ain, Mat Sin, PetscInt xadj[], PetscInt adjncy[], PetscInt nlayers, PetscBool faster_deluxe, PetscBool compute_Stilda, PetscBool reuse_solvers,PetscBool use_edges, PetscBool use_faces)
272 {
273   Mat                    F,A_II,A_IB,A_BI,A_BB,AE_II;
274   Mat                    S_all;
275   Mat                    global_schur_subsets,work_mat;
276   Mat                    S_Ej_tilda_all,S_Ej_inv_all;
277   ISLocalToGlobalMapping l2gmap_subsets;
278   IS                     is_I,is_I_layer,temp_is;
279   PetscInt               *nnz,*all_local_idx_G,*all_local_idx_N;
280   PetscInt               *auxnum1,*auxnum2,*all_local_idx_G_rep;
281   PetscInt               i,subset_size,max_subset_size;
282   PetscInt               extra,local_size,global_size;
283   PetscBLASInt           B_N,B_ierr,B_lwork,*pivots;
284   PetscScalar            *Bwork;
285   PetscSubcomm           subcomm;
286   PetscMPIInt            color,rank;
287   MPI_Comm               comm_n;
288   PetscErrorCode         ierr;
289 
290   PetscFunctionBegin;
291   /* update info in sub_schurs */
292   ierr = MatDestroy(&sub_schurs->A);CHKERRQ(ierr);
293   ierr = MatDestroy(&sub_schurs->S);CHKERRQ(ierr);
294   if (Ain) {
295     PetscBool isseqaij;
296 
297     ierr = PetscObjectTypeCompare((PetscObject)Ain,MATSEQAIJ,&isseqaij);CHKERRQ(ierr);
298     if (isseqaij) {
299       ierr = PetscObjectReference((PetscObject)Ain);CHKERRQ(ierr);
300       sub_schurs->A = Ain;
301     } else { /* SeqBAIJ matrices does not support symmetry checking, SeqSBAIJ does not support MatPermute */
302       ierr = MatConvert(Ain,MATSEQAIJ,MAT_INITIAL_MATRIX,&sub_schurs->A);CHKERRQ(ierr);
303     }
304   }
305   ierr = PetscObjectReference((PetscObject)Sin);CHKERRQ(ierr);
306   sub_schurs->S = Sin;
307   if (sub_schurs->use_mumps) {
308     sub_schurs->use_mumps = (PetscBool)(!!sub_schurs->A);
309   }
310 
311   /* preliminary checks */
312   if (!sub_schurs->use_mumps && compute_Stilda) {
313     SETERRQ(PetscObjectComm((PetscObject)sub_schurs->l2gmap),PETSC_ERR_SUP,"Adaptive selection of constraints requires MUMPS");
314   }
315   /* determine if we are dealing with hermitian positive definite problems */
316   sub_schurs->is_hermitian = PETSC_FALSE;
317   sub_schurs->is_posdef = PETSC_FALSE;
318   if (sub_schurs->A) {
319     PetscInt lsize;
320 
321     ierr = MatGetSize(sub_schurs->A,&lsize,NULL);CHKERRQ(ierr);
322     if (lsize) {
323       ierr = MatIsHermitian(sub_schurs->A,0.0,&sub_schurs->is_hermitian);CHKERRQ(ierr);
324       if (sub_schurs->is_hermitian) {
325         PetscScalar val;
326         Vec         vec1,vec2;
327 
328         ierr = MatCreateVecs(sub_schurs->A,&vec1,&vec2);CHKERRQ(ierr);
329         ierr = VecSetRandom(vec1,NULL);
330         ierr = VecCopy(vec1,vec2);CHKERRQ(ierr);
331         ierr = MatMult(sub_schurs->A,vec2,vec1);CHKERRQ(ierr);
332         ierr = VecDot(vec1,vec2,&val);CHKERRQ(ierr);
333         if (PetscRealPart(val) > 0. && PetscAbsReal(PetscImaginaryPart(val)) < PETSC_SMALL) sub_schurs->is_posdef = PETSC_TRUE;
334         ierr = VecDestroy(&vec1);CHKERRQ(ierr);
335         ierr = VecDestroy(&vec2);CHKERRQ(ierr);
336       }
337     } else {
338       sub_schurs->is_hermitian = PETSC_TRUE;
339       sub_schurs->is_posdef = PETSC_TRUE;
340     }
341     if (compute_Stilda && (!sub_schurs->is_hermitian || !sub_schurs->is_posdef)) {
342       SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_SUP,"General matrix pencils are not currently supported (%d,%d)",sub_schurs->is_hermitian,sub_schurs->is_posdef);
343     }
344   }
345   /* restrict work on active processes */
346   color = 0;
347   if (!sub_schurs->n_subs) color = 1; /* this can happen if we are in a multilevel case or if the subdomain is disconnected */
348   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)sub_schurs->l2gmap),&rank);CHKERRQ(ierr);
349   ierr = PetscSubcommCreate(PetscObjectComm((PetscObject)sub_schurs->l2gmap),&subcomm);CHKERRQ(ierr);
350   ierr = PetscSubcommSetNumber(subcomm,2);CHKERRQ(ierr);
351   ierr = PetscSubcommSetTypeGeneral(subcomm,color,rank);CHKERRQ(ierr);
352   ierr = PetscCommDuplicate(PetscSubcommChild(subcomm),&comm_n,NULL);CHKERRQ(ierr);
353   ierr = PetscSubcommDestroy(&subcomm);CHKERRQ(ierr);
354   if (!sub_schurs->n_subs) {
355     ierr = PetscCommDestroy(&comm_n);CHKERRQ(ierr);
356     PetscFunctionReturn(0);
357   }
358 
359   /* get Schur complement matrices */
360   if (!sub_schurs->use_mumps) {
361     Mat       tA_IB,tA_BI,tA_BB;
362     PetscBool isseqaij;
363     ierr = MatSchurComplementGetSubMatrices(sub_schurs->S,&A_II,NULL,&tA_IB,&tA_BI,&tA_BB);CHKERRQ(ierr);
364     ierr = PetscObjectTypeCompare((PetscObject)tA_BB,MATSEQAIJ,&isseqaij);CHKERRQ(ierr);
365     if (!isseqaij) {
366       ierr = MatConvert(tA_BB,MATSEQAIJ,MAT_INITIAL_MATRIX,&A_BB);CHKERRQ(ierr);
367       ierr = MatConvert(tA_IB,MATSEQAIJ,MAT_INITIAL_MATRIX,&A_IB);CHKERRQ(ierr);
368       ierr = MatConvert(tA_BI,MATSEQAIJ,MAT_INITIAL_MATRIX,&A_BI);CHKERRQ(ierr);
369     } else {
370       ierr = PetscObjectReference((PetscObject)tA_BB);CHKERRQ(ierr);
371       A_BB = tA_BB;
372       ierr = PetscObjectReference((PetscObject)tA_IB);CHKERRQ(ierr);
373       A_IB = tA_IB;
374       ierr = PetscObjectReference((PetscObject)tA_BI);CHKERRQ(ierr);
375       A_BI = tA_BI;
376     }
377   } else {
378     A_II = NULL;
379     A_IB = NULL;
380     A_BI = NULL;
381     A_BB = NULL;
382   }
383   S_all = NULL;
384   S_Ej_tilda_all = NULL;
385   S_Ej_inv_all = NULL;
386 
387   /* determine interior problems */
388   ierr = ISGetLocalSize(sub_schurs->is_I,&i);CHKERRQ(ierr);
389   if (nlayers >= 0 && i) { /* Interior problems can be different from the original one */
390     PetscBT                touched;
391     const PetscInt*        idx_B;
392     PetscInt               n_I,n_B,n_local_dofs,n_prev_added,j,layer,*local_numbering;
393 
394     if (xadj == NULL || adjncy == NULL) {
395       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cannot request layering without adjacency");
396     }
397     /* get sizes */
398     ierr = ISGetLocalSize(sub_schurs->is_I,&n_I);CHKERRQ(ierr);
399     ierr = ISGetLocalSize(sub_schurs->is_B,&n_B);CHKERRQ(ierr);
400 
401     ierr = PetscMalloc1(n_I+n_B,&local_numbering);CHKERRQ(ierr);
402     ierr = PetscBTCreate(n_I+n_B,&touched);CHKERRQ(ierr);
403     ierr = PetscBTMemzero(n_I+n_B,touched);CHKERRQ(ierr);
404 
405     /* all boundary dofs must be skipped when adding layers */
406     ierr = ISGetIndices(sub_schurs->is_B,&idx_B);CHKERRQ(ierr);
407     for (j=0;j<n_B;j++) {
408       ierr = PetscBTSet(touched,idx_B[j]);CHKERRQ(ierr);
409     }
410     ierr = PetscMemcpy(local_numbering,idx_B,n_B*sizeof(PetscInt));CHKERRQ(ierr);
411     ierr = ISRestoreIndices(sub_schurs->is_B,&idx_B);CHKERRQ(ierr);
412 
413     /* add prescribed number of layers of dofs */
414     n_local_dofs = n_B;
415     n_prev_added = n_B;
416     for (layer=0;layer<nlayers;layer++) {
417       PetscInt n_added;
418       if (n_local_dofs == n_I+n_B) break;
419       if (n_local_dofs > n_I+n_B) {
420         SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Error querying layer %d. Out of bound access (%d > %d)",layer,n_local_dofs,n_I+n_B);
421       }
422       ierr = PCBDDCAdjGetNextLayer_Private(local_numbering+n_local_dofs,n_prev_added,touched,xadj,adjncy,&n_added);CHKERRQ(ierr);
423       n_prev_added = n_added;
424       n_local_dofs += n_added;
425       if (!n_added) break;
426     }
427     ierr = PetscBTDestroy(&touched);CHKERRQ(ierr);
428 
429     /* IS for I layer dofs in original numbering */
430     ierr = ISCreateGeneral(PetscObjectComm((PetscObject)sub_schurs->is_I),n_local_dofs-n_B,local_numbering+n_B,PETSC_COPY_VALUES,&is_I_layer);CHKERRQ(ierr);
431     ierr = PetscFree(local_numbering);CHKERRQ(ierr);
432     ierr = ISSort(is_I_layer);CHKERRQ(ierr);
433     /* IS for I layer dofs in I numbering */
434     if (!sub_schurs->use_mumps) {
435       ISLocalToGlobalMapping ItoNmap;
436       ierr = ISLocalToGlobalMappingCreateIS(sub_schurs->is_I,&ItoNmap);CHKERRQ(ierr);
437       ierr = ISGlobalToLocalMappingApplyIS(ItoNmap,IS_GTOLM_DROP,is_I_layer,&is_I);CHKERRQ(ierr);
438       ierr = ISLocalToGlobalMappingDestroy(&ItoNmap);CHKERRQ(ierr);
439 
440       /* II block */
441       ierr = MatGetSubMatrix(A_II,is_I,is_I,MAT_INITIAL_MATRIX,&AE_II);CHKERRQ(ierr);
442     }
443   } else {
444     PetscInt n_I;
445 
446     /* IS for I dofs in original numbering */
447     ierr = PetscObjectReference((PetscObject)sub_schurs->is_I);CHKERRQ(ierr);
448     is_I_layer = sub_schurs->is_I;
449 
450     /* IS for I dofs in I numbering (strided 1) */
451     if (!sub_schurs->use_mumps) {
452       ierr = ISGetSize(sub_schurs->is_I,&n_I);CHKERRQ(ierr);
453       ierr = ISCreateStride(PetscObjectComm((PetscObject)sub_schurs->is_I),n_I,0,1,&is_I);CHKERRQ(ierr);
454 
455       /* II block is the same */
456       ierr = PetscObjectReference((PetscObject)A_II);CHKERRQ(ierr);
457       AE_II = A_II;
458     }
459   }
460 
461   /* Get info on subset sizes and sum of all subsets sizes */
462   max_subset_size = 0;
463   local_size = 0;
464   for (i=0;i<sub_schurs->n_subs;i++) {
465     ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
466     max_subset_size = PetscMax(subset_size,max_subset_size);
467     local_size += subset_size;
468   }
469 
470   /* Work arrays for local indices */
471   extra = 0;
472   if (sub_schurs->use_mumps) {
473     ierr = ISGetLocalSize(is_I_layer,&extra);CHKERRQ(ierr);
474   }
475   ierr = PetscMalloc1(local_size+extra,&all_local_idx_N);CHKERRQ(ierr);
476   if (extra) {
477     const PetscInt *idxs;
478     ierr = ISGetIndices(is_I_layer,&idxs);CHKERRQ(ierr);
479     ierr = PetscMemcpy(all_local_idx_N,idxs,extra*sizeof(PetscInt));CHKERRQ(ierr);
480     ierr = ISRestoreIndices(is_I_layer,&idxs);CHKERRQ(ierr);
481   }
482   ierr = PetscMalloc1(local_size,&nnz);CHKERRQ(ierr);
483   ierr = PetscMalloc2(sub_schurs->n_subs,&auxnum1,sub_schurs->n_subs,&auxnum2);CHKERRQ(ierr);
484 
485   /* Get local indices in local numbering */
486   local_size = 0;
487   for (i=0;i<sub_schurs->n_subs;i++) {
488     PetscInt j;
489     const    PetscInt *idxs;
490 
491     ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
492     ierr = ISGetIndices(sub_schurs->is_subs[i],&idxs);CHKERRQ(ierr);
493     /* start (smallest in global ordering) and multiplicity */
494     auxnum1[i] = idxs[0];
495     auxnum2[i] = subset_size;
496     /* subset indices in local numbering */
497     ierr = PetscMemcpy(all_local_idx_N+local_size+extra,idxs,subset_size*sizeof(PetscInt));CHKERRQ(ierr);
498     ierr = ISRestoreIndices(sub_schurs->is_subs[i],&idxs);CHKERRQ(ierr);
499     for (j=0;j<subset_size;j++) nnz[local_size+j] = subset_size;
500     local_size += subset_size;
501   }
502 
503   /* allocate extra workspace needed only for GETRI */
504   Bwork = NULL;
505   pivots = NULL;
506   if (sub_schurs->n_subs && !sub_schurs->is_hermitian) {
507     PetscScalar lwork;
508 
509     B_lwork = -1;
510     ierr = PetscBLASIntCast(local_size,&B_N);CHKERRQ(ierr);
511     ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
512     PetscStackCallBLAS("LAPACKgetri",LAPACKgetri_(&B_N,Bwork,&B_N,pivots,&lwork,&B_lwork,&B_ierr));
513     ierr = PetscFPTrapPop();CHKERRQ(ierr);
514     if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in query to GETRI Lapack routine %d",(int)B_ierr);
515     ierr = PetscBLASIntCast((PetscInt)PetscRealPart(lwork),&B_lwork);CHKERRQ(ierr);
516     ierr = PetscMalloc2(B_lwork,&Bwork,B_N,&pivots);CHKERRQ(ierr);
517   }
518 
519   /* prepare parallel matrices for summing up properly schurs on subsets */
520   ierr = PCBDDCSubsetNumbering(comm_n,sub_schurs->l2gmap,sub_schurs->n_subs,auxnum1,auxnum2,&global_size,&all_local_idx_G_rep);CHKERRQ(ierr);
521   ierr = PetscMalloc1(local_size,&all_local_idx_G);CHKERRQ(ierr);
522   local_size = 0;
523   for (i=0;i<sub_schurs->n_subs;i++) {
524     PetscInt j;
525     for (j=0;j<auxnum2[i];j++) all_local_idx_G[local_size++] = all_local_idx_G_rep[i] + j;
526   }
527   ierr = PetscFree(all_local_idx_G_rep);CHKERRQ(ierr);
528   ierr = PetscFree2(auxnum1,auxnum2);CHKERRQ(ierr);
529   ierr = ISLocalToGlobalMappingCreate(comm_n,1,local_size,all_local_idx_G,PETSC_COPY_VALUES,&l2gmap_subsets);CHKERRQ(ierr);
530   ierr = MatCreateIS(comm_n,1,PETSC_DECIDE,PETSC_DECIDE,global_size,global_size,l2gmap_subsets,&work_mat);CHKERRQ(ierr);
531   ierr = ISLocalToGlobalMappingDestroy(&l2gmap_subsets);CHKERRQ(ierr);
532   ierr = MatCreate(PetscObjectComm((PetscObject)work_mat),&global_schur_subsets);CHKERRQ(ierr);
533   ierr = MatSetSizes(global_schur_subsets,PETSC_DECIDE,PETSC_DECIDE,global_size,global_size);CHKERRQ(ierr);
534   ierr = MatSetType(global_schur_subsets,MATMPIAIJ);CHKERRQ(ierr);
535 
536   /* subset indices in local boundary numbering */
537   if (!sub_schurs->is_Ej_all) {
538     PetscInt *all_local_idx_B;
539 
540     ierr = PetscMalloc1(local_size,&all_local_idx_B);CHKERRQ(ierr);
541     ierr = ISGlobalToLocalMappingApply(sub_schurs->BtoNmap,IS_GTOLM_DROP,local_size,all_local_idx_N+extra,&subset_size,all_local_idx_B);CHKERRQ(ierr);
542     if (subset_size != local_size) {
543       SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Error in sub_schurs serial (BtoNmap)! %d != %d\n",subset_size,local_size);
544     }
545     ierr = ISCreateGeneral(PETSC_COMM_SELF,local_size,all_local_idx_B,PETSC_OWN_POINTER,&sub_schurs->is_Ej_all);CHKERRQ(ierr);
546   }
547 
548   /* Local matrix of all local Schur on subsets (transposed) */
549   if (!sub_schurs->S_Ej_all) {
550     ierr = MatCreate(PETSC_COMM_SELF,&sub_schurs->S_Ej_all);CHKERRQ(ierr);
551     ierr = MatSetSizes(sub_schurs->S_Ej_all,PETSC_DECIDE,PETSC_DECIDE,local_size,local_size);CHKERRQ(ierr);
552     ierr = MatSetType(sub_schurs->S_Ej_all,MATAIJ);CHKERRQ(ierr);
553     ierr = MatSeqAIJSetPreallocation(sub_schurs->S_Ej_all,0,nnz);CHKERRQ(ierr);
554   } else {
555     ierr = MatZeroEntries(sub_schurs->S_Ej_all);CHKERRQ(ierr);
556   }
557 
558   /* Compute Schur complements explicitly */
559   F = NULL;
560   ierr = PetscBTMemzero(sub_schurs->n_subs,sub_schurs->computed_Stilda_subs);CHKERRQ(ierr);
561   if (!sub_schurs->use_mumps) {
562     Mat         S_Ej_expl;
563     PetscScalar *work;
564     PetscInt    j,*dummy_idx;
565     PetscBool   Sdense;
566 
567     ierr = PetscMalloc2(max_subset_size,&dummy_idx,max_subset_size*max_subset_size,&work);CHKERRQ(ierr);
568     local_size = 0;
569     for (i=0;i<sub_schurs->n_subs;i++) {
570       IS  is_subset_B;
571       Mat AE_EE,AE_IE,AE_EI,S_Ej;
572 
573       /* subsets in original and boundary numbering */
574       ierr = ISGlobalToLocalMappingApplyIS(sub_schurs->BtoNmap,IS_GTOLM_DROP,sub_schurs->is_subs[i],&is_subset_B);CHKERRQ(ierr);
575       /* EE block */
576       ierr = MatGetSubMatrix(A_BB,is_subset_B,is_subset_B,MAT_INITIAL_MATRIX,&AE_EE);CHKERRQ(ierr);
577       /* IE block */
578       ierr = MatGetSubMatrix(A_IB,is_I,is_subset_B,MAT_INITIAL_MATRIX,&AE_IE);CHKERRQ(ierr);
579       /* EI block */
580       if (sub_schurs->is_hermitian) {
581         ierr = MatCreateTranspose(AE_IE,&AE_EI);CHKERRQ(ierr);
582       } else {
583         ierr = MatGetSubMatrix(A_BI,is_subset_B,is_I,MAT_INITIAL_MATRIX,&AE_EI);CHKERRQ(ierr);
584       }
585       ierr = ISDestroy(&is_subset_B);CHKERRQ(ierr);
586       ierr = MatCreateSchurComplement(AE_II,AE_II,AE_IE,AE_EI,AE_EE,&S_Ej);CHKERRQ(ierr);
587       ierr = MatDestroy(&AE_EE);CHKERRQ(ierr);
588       ierr = MatDestroy(&AE_IE);CHKERRQ(ierr);
589       ierr = MatDestroy(&AE_EI);CHKERRQ(ierr);
590       if (AE_II == A_II) { /* we can reuse the same ksp */
591         KSP ksp;
592         ierr = MatSchurComplementGetKSP(sub_schurs->S,&ksp);CHKERRQ(ierr);
593         ierr = MatSchurComplementSetKSP(S_Ej,ksp);CHKERRQ(ierr);
594       } else { /* build new ksp object which inherits ksp and pc types from the original one */
595         KSP       origksp,schurksp;
596         PC        origpc,schurpc;
597         KSPType   ksp_type;
598         PetscInt  n_internal;
599         PetscBool ispcnone;
600 
601         ierr = MatSchurComplementGetKSP(sub_schurs->S,&origksp);CHKERRQ(ierr);
602         ierr = MatSchurComplementGetKSP(S_Ej,&schurksp);CHKERRQ(ierr);
603         ierr = KSPGetType(origksp,&ksp_type);CHKERRQ(ierr);
604         ierr = KSPSetType(schurksp,ksp_type);CHKERRQ(ierr);
605         ierr = KSPGetPC(schurksp,&schurpc);CHKERRQ(ierr);
606         ierr = KSPGetPC(origksp,&origpc);CHKERRQ(ierr);
607         ierr = PetscObjectTypeCompare((PetscObject)origpc,PCNONE,&ispcnone);CHKERRQ(ierr);
608         if (!ispcnone) {
609           PCType pc_type;
610           ierr = PCGetType(origpc,&pc_type);CHKERRQ(ierr);
611           ierr = PCSetType(schurpc,pc_type);CHKERRQ(ierr);
612         } else {
613           ierr = PCSetType(schurpc,PCLU);CHKERRQ(ierr);
614         }
615         ierr = ISGetSize(is_I,&n_internal);CHKERRQ(ierr);
616         if (n_internal) { /* UMFPACK gives error with 0 sized problems */
617           MatSolverPackage solver=NULL;
618           ierr = PCFactorGetMatSolverPackage(origpc,(const MatSolverPackage*)&solver);CHKERRQ(ierr);
619           if (solver) {
620             ierr = PCFactorSetMatSolverPackage(schurpc,solver);CHKERRQ(ierr);
621           }
622         }
623         ierr = KSPSetUp(schurksp);CHKERRQ(ierr);
624       }
625       ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
626       ierr = MatCreateSeqDense(PETSC_COMM_SELF,subset_size,subset_size,work,&S_Ej_expl);CHKERRQ(ierr);
627       ierr = PCBDDCComputeExplicitSchur(S_Ej,sub_schurs->is_hermitian,MAT_REUSE_MATRIX,&S_Ej_expl);CHKERRQ(ierr);
628       ierr = PetscObjectTypeCompare((PetscObject)S_Ej_expl,MATSEQDENSE,&Sdense);CHKERRQ(ierr);
629       if (Sdense) {
630         for (j=0;j<subset_size;j++) {
631           dummy_idx[j]=local_size+j;
632         }
633         ierr = MatSetValues(sub_schurs->S_Ej_all,subset_size,dummy_idx,subset_size,dummy_idx,work,INSERT_VALUES);CHKERRQ(ierr);
634       } else {
635         SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not yet implemented for sparse matrices");
636       }
637       ierr = MatDestroy(&S_Ej);CHKERRQ(ierr);
638       ierr = MatDestroy(&S_Ej_expl);CHKERRQ(ierr);
639       local_size += subset_size;
640     }
641     ierr = PetscFree2(dummy_idx,work);CHKERRQ(ierr);
642     /* free */
643     ierr = ISDestroy(&is_I);CHKERRQ(ierr);
644     ierr = MatDestroy(&AE_II);CHKERRQ(ierr);
645     ierr = PetscFree(all_local_idx_N);CHKERRQ(ierr);
646   } else {
647     Mat         A;
648     IS          is_A_all;
649     PetscScalar *work,*S_data;
650     PetscInt    *idxs_schur,n_I,n_I_all,*dummy_idx,size_schur,size_active_schur,cum,cum2;
651     PetscBool   restore_S;
652 
653     /* get working mat */
654     ierr = ISGetLocalSize(is_I_layer,&n_I);CHKERRQ(ierr);
655     if (!sub_schurs->is_dir) {
656       ierr = ISCreateGeneral(PETSC_COMM_SELF,local_size+n_I,all_local_idx_N,PETSC_COPY_VALUES,&is_A_all);CHKERRQ(ierr);
657       size_schur = local_size;
658     } else {
659       IS list[2];
660 
661       ierr = ISCreateGeneral(PETSC_COMM_SELF,local_size+n_I,all_local_idx_N,PETSC_COPY_VALUES,&list[0]);CHKERRQ(ierr);
662       list[1] = sub_schurs->is_dir;
663       ierr = ISConcatenate(PETSC_COMM_SELF,2,list,&is_A_all);CHKERRQ(ierr);
664       ierr = ISDestroy(&list[0]);CHKERRQ(ierr);
665       ierr = ISGetLocalSize(sub_schurs->is_dir,&size_schur);CHKERRQ(ierr);
666       size_schur += local_size;
667     }
668     ierr = PetscFree(all_local_idx_N);CHKERRQ(ierr);
669     size_active_schur = local_size; /* size active schurs does not count any dirichlet dof on the interface */
670     ierr = MatGetSubMatrix(sub_schurs->A,is_A_all,is_A_all,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr);
671     ierr = MatSetOptionsPrefix(A,"sub_schurs_");CHKERRQ(ierr);
672 
673     if (n_I) {
674       if (sub_schurs->is_hermitian && sub_schurs->is_posdef) {
675         ierr = MatSetOption(A,MAT_SPD,PETSC_TRUE);CHKERRQ(ierr);
676         ierr = MatGetFactor(A,MATSOLVERMUMPS,MAT_FACTOR_CHOLESKY,&F);CHKERRQ(ierr);
677       } else {
678         ierr = MatSetOption(A,MAT_SYMMETRIC,sub_schurs->is_hermitian);CHKERRQ(ierr);
679         ierr = MatGetFactor(A,MATSOLVERMUMPS,MAT_FACTOR_LU,&F);CHKERRQ(ierr);
680       }
681 
682       /* subsets ordered last */
683       ierr = PetscMalloc1(size_schur,&idxs_schur);CHKERRQ(ierr);
684       for (i=0;i<size_schur;i++) {
685         idxs_schur[i] = n_I+i+1;
686       }
687 #if defined(PETSC_HAVE_MUMPS)
688       ierr = MatMumpsSetSchurIndices(F,size_schur,idxs_schur);CHKERRQ(ierr);
689 #endif
690       ierr = PetscFree(idxs_schur);CHKERRQ(ierr);
691 
692       /* factorization step */
693       if (sub_schurs->is_hermitian && sub_schurs->is_posdef) {
694         ierr = MatCholeskyFactorSymbolic(F,A,NULL,NULL);CHKERRQ(ierr);
695 #if defined(PETSC_HAVE_MUMPS) /* be sure that icntl 19 is not set by command line */
696         ierr = MatMumpsSetIcntl(F,19,2);CHKERRQ(ierr);
697 #endif
698         ierr = MatCholeskyFactorNumeric(F,A,NULL);CHKERRQ(ierr);
699       } else {
700         ierr = MatLUFactorSymbolic(F,A,NULL,NULL,NULL);CHKERRQ(ierr);
701 #if defined(PETSC_HAVE_MUMPS) /* be sure that icntl 19 is not set by command line */
702         ierr = MatMumpsSetIcntl(F,19,3);CHKERRQ(ierr);
703 #endif
704         ierr = MatLUFactorNumeric(F,A,NULL);CHKERRQ(ierr);
705       }
706 
707       /* get explicit Schur Complement computed during numeric factorization */
708 #if defined(PETSC_HAVE_MUMPS)
709       ierr = MatMumpsGetSchurComplement(F,&S_all);CHKERRQ(ierr);
710 #endif
711 
712       /* we can reuse the solvers if we are not using the economic version */
713       ierr = ISGetLocalSize(sub_schurs->is_I,&n_I_all);CHKERRQ(ierr);
714       reuse_solvers = (PetscBool)(reuse_solvers && (n_I == n_I_all));
715       restore_S = PETSC_TRUE;
716     } else { /* we can't use MUMPS when size_schur == size_of_the_problem */
717       ierr = MatConvert(A,MATSEQDENSE,MAT_INITIAL_MATRIX,&S_all);CHKERRQ(ierr);
718       reuse_solvers = PETSC_FALSE;
719       restore_S = PETSC_FALSE;
720     }
721 
722     if (reuse_solvers) {
723       Mat              A_II;
724       Vec              vec1_B;
725       PCBDDCReuseMumps msolv_ctx;
726 
727       if (sub_schurs->reuse_mumps) {
728         ierr = PCBDDCReuseMumpsReset(sub_schurs->reuse_mumps);CHKERRQ(ierr);
729       } else {
730         ierr = PetscNew(&sub_schurs->reuse_mumps);CHKERRQ(ierr);
731       }
732       msolv_ctx = sub_schurs->reuse_mumps;
733       ierr = MatSchurComplementGetSubMatrices(sub_schurs->S,&A_II,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
734       ierr = MatGetSize(A_II,&msolv_ctx->n_I,NULL);CHKERRQ(ierr);
735       ierr = PetscObjectReference((PetscObject)F);CHKERRQ(ierr);
736       msolv_ctx->F = F;
737       ierr = MatCreateVecs(F,&msolv_ctx->sol,&msolv_ctx->rhs);CHKERRQ(ierr);
738 
739       /* interior solver */
740       ierr = PCCreate(PETSC_COMM_SELF,&msolv_ctx->interior_solver);CHKERRQ(ierr);
741       ierr = PCSetOperators(msolv_ctx->interior_solver,A_II,A_II);CHKERRQ(ierr);
742       ierr = PCSetType(msolv_ctx->interior_solver,PCSHELL);CHKERRQ(ierr);
743       ierr = PCShellSetContext(msolv_ctx->interior_solver,msolv_ctx);CHKERRQ(ierr);
744       ierr = PCShellSetApply(msolv_ctx->interior_solver,PCBDDCMumpsInteriorSolve);CHKERRQ(ierr);
745       ierr = PCShellSetApplyTranspose(msolv_ctx->interior_solver,PCBDDCMumpsInteriorSolveTranspose);CHKERRQ(ierr);
746 
747       /* correction solver */
748       ierr = PCCreate(PETSC_COMM_SELF,&msolv_ctx->correction_solver);CHKERRQ(ierr);
749       ierr = PCSetOperators(msolv_ctx->correction_solver,A,A);CHKERRQ(ierr);
750       ierr = PCSetType(msolv_ctx->correction_solver,PCSHELL);CHKERRQ(ierr);
751       ierr = PCShellSetContext(msolv_ctx->correction_solver,msolv_ctx);CHKERRQ(ierr);
752       ierr = PCShellSetApply(msolv_ctx->correction_solver,PCBDDCMumpsCorrectionSolve);CHKERRQ(ierr);
753       ierr = PCShellSetApplyTranspose(msolv_ctx->correction_solver,PCBDDCMumpsCorrectionSolveTranspose);CHKERRQ(ierr);
754 
755       /* scatter and vecs for Schur complement solver */
756       ierr = MatCreateVecs(S_all,&msolv_ctx->sol_B,&msolv_ctx->rhs_B);CHKERRQ(ierr);
757       ierr = MatCreateVecs(sub_schurs->S,&vec1_B,NULL);CHKERRQ(ierr);
758       ierr = ISGlobalToLocalMappingApplyIS(sub_schurs->BtoNmap,IS_GTOLM_DROP,is_A_all,&msolv_ctx->is_B);CHKERRQ(ierr);
759       ierr = VecScatterCreate(vec1_B,msolv_ctx->is_B,msolv_ctx->sol_B,NULL,&msolv_ctx->correction_scatter_B);CHKERRQ(ierr);
760       ierr = VecDestroy(&vec1_B);CHKERRQ(ierr);
761       ierr = PetscObjectReference((PetscObject)is_A_all);CHKERRQ(ierr);
762       msolv_ctx->is_R = is_A_all;
763     }
764     ierr = MatDestroy(&A);CHKERRQ(ierr);
765     ierr = ISDestroy(&is_A_all);CHKERRQ(ierr);
766 
767     /* Work arrays */
768     ierr = PetscMalloc2(max_subset_size,&dummy_idx,max_subset_size*max_subset_size,&work);CHKERRQ(ierr);
769     if (compute_Stilda) {
770       ierr = MatCreate(PETSC_COMM_SELF,&S_Ej_tilda_all);CHKERRQ(ierr);
771       ierr = MatSetSizes(S_Ej_tilda_all,PETSC_DECIDE,PETSC_DECIDE,size_active_schur,size_active_schur);CHKERRQ(ierr);
772       ierr = MatSetType(S_Ej_tilda_all,MATAIJ);CHKERRQ(ierr);
773       ierr = MatSeqAIJSetPreallocation(S_Ej_tilda_all,0,nnz);CHKERRQ(ierr);
774       ierr = MatCreate(PETSC_COMM_SELF,&S_Ej_inv_all);CHKERRQ(ierr);
775       ierr = MatSetSizes(S_Ej_inv_all,PETSC_DECIDE,PETSC_DECIDE,size_active_schur,size_active_schur);CHKERRQ(ierr);
776       ierr = MatSetType(S_Ej_inv_all,MATAIJ);CHKERRQ(ierr);
777       ierr = MatSeqAIJSetPreallocation(S_Ej_inv_all,0,nnz);CHKERRQ(ierr);
778     }
779 
780     /* S_Ej_all */
781     cum = cum2 = 0;
782     ierr = MatDenseGetArray(S_all,&S_data);CHKERRQ(ierr);
783     for (i=0;i<sub_schurs->n_subs;i++) {
784       PetscInt j;
785 
786       /* get S_E */
787       ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
788       if (restore_S && sub_schurs->is_hermitian) { /* When using MUMPS data I need to expand to upper triangular (column oriented) */
789         PetscInt k;
790         for (k=0;k<subset_size;k++) {
791           for (j=k;j<subset_size;j++) {
792             work[k*subset_size+j] = S_data[cum2+k*size_schur+j];
793             work[j*subset_size+k] = S_data[cum2+k*size_schur+j];
794           }
795         }
796       } else { /* copy to workspace */
797         PetscInt k;
798         for (k=0;k<subset_size;k++) {
799           for (j=0;j<subset_size;j++) {
800             work[k*subset_size+j] = S_data[cum2+k*size_schur+j];
801           }
802         }
803       }
804       /* insert S_E values */
805       for (j=0;j<subset_size;j++) dummy_idx[j] = cum+j;
806       ierr = MatSetValues(sub_schurs->S_Ej_all,subset_size,dummy_idx,subset_size,dummy_idx,work,INSERT_VALUES);CHKERRQ(ierr);
807 
808       /* if adaptivity is requested, invert S_E block */
809       if (compute_Stilda && ((PetscBTLookup(sub_schurs->is_edge,i) && use_edges) || (!PetscBTLookup(sub_schurs->is_edge,i) && use_faces))) {
810         ierr = PetscBLASIntCast(subset_size,&B_N);CHKERRQ(ierr);
811         ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
812         if (!sub_schurs->is_hermitian) { /* TODO add sytrf/i for symmetric non hermitian */
813           PetscStackCallBLAS("LAPACKgetrf",LAPACKgetrf_(&B_N,&B_N,work,&B_N,pivots,&B_ierr));
814           if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRF Lapack routine %d",(int)B_ierr);
815           PetscStackCallBLAS("LAPACKgetri",LAPACKgetri_(&B_N,work,&B_N,pivots,Bwork,&B_lwork,&B_ierr));
816           if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRI Lapack routine %d",(int)B_ierr);
817         } else {
818           PetscStackCallBLAS("LAPACKpotrf",LAPACKpotrf_("L",&B_N,work,&B_N,&B_ierr));
819           if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRF Lapack routine %d",(int)B_ierr);
820           PetscStackCallBLAS("LAPACKpotri",LAPACKpotri_("L",&B_N,work,&B_N,&B_ierr));
821           if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRI Lapack routine %d",(int)B_ierr);
822         }
823         ierr = PetscFPTrapPop();CHKERRQ(ierr);
824         ierr = MatSetValues(S_Ej_inv_all,subset_size,dummy_idx,subset_size,dummy_idx,work,INSERT_VALUES);CHKERRQ(ierr);
825       }
826       cum += subset_size;
827       cum2 += subset_size*(size_schur + 1);
828     }
829     ierr = MatDenseRestoreArray(S_all,&S_data);CHKERRQ(ierr);
830 #if defined(PETSC_HAVE_MUMPS)
831     if (restore_S) {
832       ierr = MatMumpsRestoreSchurComplement(F,&S_all);CHKERRQ(ierr);
833       ierr = MatMumpsInvertSchurComplement(F);CHKERRQ(ierr);
834       ierr = MatMumpsGetSchurComplement(F,&S_all);CHKERRQ(ierr);
835     } else if (compute_Stilda) { /* we need to invert explicitly since we are not using MUMPS */
836       ierr = MatDenseGetArray(S_all,&S_data);CHKERRQ(ierr);
837       ierr = PetscBLASIntCast(size_schur,&B_N);CHKERRQ(ierr);
838       ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
839       if (!sub_schurs->is_hermitian) { /* TODO add sytrf/i for symmetric non hermitian */
840         PetscStackCallBLAS("LAPACKgetrf",LAPACKgetrf_(&B_N,&B_N,S_data,&B_N,pivots,&B_ierr));
841         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRF Lapack routine %d",(int)B_ierr);
842         PetscStackCallBLAS("LAPACKgetri",LAPACKgetri_(&B_N,S_data,&B_N,pivots,Bwork,&B_lwork,&B_ierr));
843         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRI Lapack routine %d",(int)B_ierr);
844       } else {
845         PetscStackCallBLAS("LAPACKpotrf",LAPACKpotrf_("L",&B_N,S_data,&B_N,&B_ierr));
846         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRF Lapack routine %d",(int)B_ierr);
847         PetscStackCallBLAS("LAPACKpotri",LAPACKpotri_("L",&B_N,S_data,&B_N,&B_ierr));
848         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRI Lapack routine %d",(int)B_ierr);
849       }
850       ierr = PetscFPTrapPop();CHKERRQ(ierr);
851       ierr = MatDenseRestoreArray(S_all,&S_data);CHKERRQ(ierr);
852     }
853 #endif
854     /* S_Ej_tilda_all */
855     cum = cum2 = 0;
856     ierr = MatDenseGetArray(S_all,&S_data);CHKERRQ(ierr);
857     for (i=0;i<sub_schurs->n_subs;i++) {
858       ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
859       /* if adaptivity is requested, invert S_E and insert St_E^-1 blocks */
860       if (compute_Stilda && ((PetscBTLookup(sub_schurs->is_edge,i) && use_edges) || (!PetscBTLookup(sub_schurs->is_edge,i) && use_faces))) {
861         PetscInt j;
862         /* get (St^-1)_E */
863         if (sub_schurs->is_hermitian) { /* I need to expand to upper triangular (column oriented) */
864           PetscInt k;
865           for (k=0;k<subset_size;k++) {
866             for (j=k;j<subset_size;j++) {
867               work[k*subset_size+j] = S_data[cum2+k*size_schur+j];
868               work[j*subset_size+k] = S_data[cum2+k*size_schur+j];
869             }
870           }
871         } else { /* copy to workspace */
872           PetscInt k;
873           for (k=0;k<subset_size;k++) {
874             for (j=0;j<subset_size;j++) {
875               work[k*subset_size+j] = S_data[cum2+k*size_schur+j];
876             }
877           }
878         }
879         for (j=0;j<subset_size;j++) dummy_idx[j] = cum+j;
880         ierr = MatSetValues(S_Ej_tilda_all,subset_size,dummy_idx,subset_size,dummy_idx,work,INSERT_VALUES);CHKERRQ(ierr);
881         ierr = PetscBTSet(sub_schurs->computed_Stilda_subs,i);CHKERRQ(ierr);
882       }
883       cum += subset_size;
884       cum2 += subset_size*(size_schur + 1);
885     }
886     ierr = MatDenseRestoreArray(S_all,&S_data);CHKERRQ(ierr);
887     ierr = PetscFree2(dummy_idx,work);CHKERRQ(ierr);
888 #if defined(PETSC_HAVE_MUMPS)
889     if (restore_S) {
890       ierr = MatMumpsRestoreSchurComplement(F,&S_all);CHKERRQ(ierr);
891     }
892 #endif
893   }
894   ierr = MatDestroy(&F);CHKERRQ(ierr);
895   ierr = ISDestroy(&is_I_layer);CHKERRQ(ierr);
896   ierr = PetscFree(nnz);CHKERRQ(ierr);
897   ierr = MatDestroy(&S_all);CHKERRQ(ierr);
898   ierr = MatDestroy(&A_BB);CHKERRQ(ierr);
899   ierr = MatDestroy(&A_IB);CHKERRQ(ierr);
900   ierr = MatDestroy(&A_BI);CHKERRQ(ierr);
901   ierr = MatAssemblyBegin(sub_schurs->S_Ej_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
902   ierr = MatAssemblyEnd(sub_schurs->S_Ej_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
903   if (compute_Stilda) {
904     ierr = MatAssemblyBegin(S_Ej_tilda_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
905     ierr = MatAssemblyEnd(S_Ej_tilda_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
906     ierr = MatAssemblyBegin(S_Ej_inv_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
907     ierr = MatAssemblyEnd(S_Ej_inv_all,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
908   }
909 
910   /* Global matrix of all assembled Schur on subsets */
911   ierr = MatISSetLocalMat(work_mat,sub_schurs->S_Ej_all);CHKERRQ(ierr);
912   ierr = MatISSetMPIXAIJPreallocation_Private(work_mat,global_schur_subsets,PETSC_TRUE);CHKERRQ(ierr);
913   ierr = MatISGetMPIXAIJ(work_mat,MAT_REUSE_MATRIX,&global_schur_subsets);CHKERRQ(ierr);
914 
915   /* Get local part of (\sum_j S_Ej) */
916   ierr = ISCreateGeneral(comm_n,local_size,all_local_idx_G,PETSC_OWN_POINTER,&temp_is);CHKERRQ(ierr);
917   ierr = MatDestroy(&sub_schurs->sum_S_Ej_all);CHKERRQ(ierr);
918   ierr = MatGetSubMatrixUnsorted(global_schur_subsets,temp_is,temp_is,&sub_schurs->sum_S_Ej_all);CHKERRQ(ierr);
919 
920   /* Compute explicitly (\sum_j S_Ej)^-1 (faster scaling during PCApply, needs extra work when doing setup) */
921   if (faster_deluxe) {
922     Mat         tmpmat;
923     PetscScalar *array;
924     PetscInt    cum;
925 
926     ierr = MatSeqAIJGetArray(sub_schurs->sum_S_Ej_all,&array);CHKERRQ(ierr);
927     cum = 0;
928     for (i=0;i<sub_schurs->n_subs;i++) {
929       ierr = ISGetLocalSize(sub_schurs->is_subs[i],&subset_size);CHKERRQ(ierr);
930       ierr = PetscBLASIntCast(subset_size,&B_N);CHKERRQ(ierr);
931       ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
932       if (!sub_schurs->is_hermitian) {
933         PetscStackCallBLAS("LAPACKgetrf",LAPACKgetrf_(&B_N,&B_N,array+cum,&B_N,pivots,&B_ierr));
934         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRF Lapack routine %d",(int)B_ierr);
935         PetscStackCallBLAS("LAPACKgetri",LAPACKgetri_(&B_N,array+cum,&B_N,pivots,Bwork,&B_lwork,&B_ierr));
936         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in GETRI Lapack routine %d",(int)B_ierr);
937       } else {
938         PetscInt j,k;
939 
940         PetscStackCallBLAS("LAPACKpotrf",LAPACKpotrf_("L",&B_N,array+cum,&B_N,&B_ierr));
941         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRF Lapack routine %d",(int)B_ierr);
942         PetscStackCallBLAS("LAPACKpotri",LAPACKpotri_("L",&B_N,array+cum,&B_N,&B_ierr));
943         if (B_ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in POTRI Lapack routine %d",(int)B_ierr);
944         for (j=0;j<B_N;j++) {
945           for (k=j+1;k<B_N;k++) {
946             array[k*B_N+j+cum] = array[j*B_N+k+cum];
947           }
948         }
949       }
950       ierr = PetscFPTrapPop();CHKERRQ(ierr);
951       cum += subset_size*subset_size;
952     }
953     ierr = MatSeqAIJRestoreArray(sub_schurs->sum_S_Ej_all,&array);CHKERRQ(ierr);
954     ierr = MatMatMult(sub_schurs->S_Ej_all,sub_schurs->sum_S_Ej_all,MAT_INITIAL_MATRIX,1.0,&tmpmat);CHKERRQ(ierr);
955     ierr = MatDestroy(&sub_schurs->S_Ej_all);CHKERRQ(ierr);
956     ierr = MatDestroy(&sub_schurs->sum_S_Ej_all);CHKERRQ(ierr);
957     sub_schurs->S_Ej_all = tmpmat;
958   }
959 
960   /* Get local part of (\sum_j S^-1_Ej) (\sum_j St^-1_Ej) */
961   if (compute_Stilda) {
962     ierr = MatISSetLocalMat(work_mat,S_Ej_tilda_all);CHKERRQ(ierr);
963     ierr = MatISGetMPIXAIJ(work_mat,MAT_REUSE_MATRIX,&global_schur_subsets);CHKERRQ(ierr);
964     ierr = MatDestroy(&sub_schurs->sum_S_Ej_tilda_all);CHKERRQ(ierr);
965     ierr = MatGetSubMatrixUnsorted(global_schur_subsets,temp_is,temp_is,&sub_schurs->sum_S_Ej_tilda_all);CHKERRQ(ierr);
966     ierr = MatISSetLocalMat(work_mat,S_Ej_inv_all);CHKERRQ(ierr);
967     ierr = MatISGetMPIXAIJ(work_mat,MAT_REUSE_MATRIX,&global_schur_subsets);CHKERRQ(ierr);
968     ierr = MatDestroy(&sub_schurs->sum_S_Ej_inv_all);CHKERRQ(ierr);
969     ierr = MatGetSubMatrixUnsorted(global_schur_subsets,temp_is,temp_is,&sub_schurs->sum_S_Ej_inv_all);CHKERRQ(ierr);
970   }
971 
972   /* free workspace */
973   ierr = PetscFree2(Bwork,pivots);CHKERRQ(ierr);
974   ierr = MatDestroy(&global_schur_subsets);CHKERRQ(ierr);
975   ierr = MatDestroy(&S_Ej_tilda_all);CHKERRQ(ierr);
976   ierr = MatDestroy(&S_Ej_inv_all);CHKERRQ(ierr);
977   ierr = MatDestroy(&work_mat);CHKERRQ(ierr);
978   ierr = ISDestroy(&temp_is);CHKERRQ(ierr);
979   ierr = PetscCommDestroy(&comm_n);CHKERRQ(ierr);
980   PetscFunctionReturn(0);
981 }
982 
983 #undef __FUNCT__
984 #define __FUNCT__ "PCBDDCSubSchursInit"
985 PetscErrorCode PCBDDCSubSchursInit(PCBDDCSubSchurs sub_schurs, IS is_I, IS is_B, PCBDDCGraph graph, ISLocalToGlobalMapping BtoNmap)
986 {
987   IS              *faces,*edges,*all_cc,vertices;
988   PetscInt        i,n_faces,n_edges,n_all_cc;
989   PetscBool       is_sorted;
990   PetscErrorCode  ierr;
991 
992   PetscFunctionBegin;
993   ierr = ISSorted(is_I,&is_sorted);CHKERRQ(ierr);
994   if (!is_sorted) {
995     SETERRQ(PetscObjectComm((PetscObject)is_I),PETSC_ERR_PLIB,"IS for I dofs should be shorted");
996   }
997   ierr = ISSorted(is_B,&is_sorted);CHKERRQ(ierr);
998   if (!is_sorted) {
999     SETERRQ(PetscObjectComm((PetscObject)is_B),PETSC_ERR_PLIB,"IS for B dofs should be shorted");
1000   }
1001 
1002   /* reset any previous data */
1003   ierr = PCBDDCSubSchursReset(sub_schurs);CHKERRQ(ierr);
1004 
1005   /* get index sets for faces and edges (already sorted by global ordering) */
1006   ierr = PCBDDCGraphGetCandidatesIS(graph,&n_faces,&faces,&n_edges,&edges,&vertices);CHKERRQ(ierr);
1007   n_all_cc = n_faces+n_edges;
1008   ierr = PetscBTCreate(n_all_cc,&sub_schurs->is_edge);CHKERRQ(ierr);
1009   ierr = PetscBTCreate(n_all_cc,&sub_schurs->computed_Stilda_subs);CHKERRQ(ierr);
1010   ierr = PetscMalloc1(n_all_cc,&all_cc);CHKERRQ(ierr);
1011   for (i=0;i<n_faces;i++) {
1012     all_cc[i] = faces[i];
1013   }
1014   for (i=0;i<n_edges;i++) {
1015     all_cc[n_faces+i] = edges[i];
1016     ierr = PetscBTSet(sub_schurs->is_edge,n_faces+i);CHKERRQ(ierr);
1017   }
1018   ierr = PetscFree(faces);CHKERRQ(ierr);
1019   ierr = PetscFree(edges);CHKERRQ(ierr);
1020   sub_schurs->is_dir = NULL;
1021   ierr = PCBDDCGraphGetDirichletDofsB(graph,&sub_schurs->is_dir);CHKERRQ(ierr);
1022 
1023   /* Determine if MUMPS can be used */
1024   sub_schurs->use_mumps = PETSC_FALSE;
1025 #if defined(PETSC_HAVE_MUMPS)
1026   sub_schurs->use_mumps = PETSC_TRUE;
1027 #endif
1028 
1029   ierr = PetscObjectReference((PetscObject)is_I);CHKERRQ(ierr);
1030   sub_schurs->is_I = is_I;
1031   ierr = PetscObjectReference((PetscObject)is_B);CHKERRQ(ierr);
1032   sub_schurs->is_B = is_B;
1033   ierr = PetscObjectReference((PetscObject)graph->l2gmap);CHKERRQ(ierr);
1034   sub_schurs->l2gmap = graph->l2gmap;
1035   ierr = PetscObjectReference((PetscObject)BtoNmap);CHKERRQ(ierr);
1036   sub_schurs->BtoNmap = BtoNmap;
1037   sub_schurs->n_subs = n_all_cc;
1038   sub_schurs->is_subs = all_cc;
1039   if (!sub_schurs->use_mumps) { /* sort by local ordering mumps is not present */
1040     for (i=0;i<sub_schurs->n_subs;i++) {
1041       ierr = ISSort(sub_schurs->is_subs[i]);CHKERRQ(ierr);
1042     }
1043   }
1044   sub_schurs->is_vertices = vertices;
1045   sub_schurs->S_Ej_all = NULL;
1046   sub_schurs->sum_S_Ej_all = NULL;
1047   sub_schurs->sum_S_Ej_inv_all = NULL;
1048   sub_schurs->sum_S_Ej_tilda_all = NULL;
1049   sub_schurs->is_Ej_all = NULL;
1050   PetscFunctionReturn(0);
1051 }
1052 
1053 #undef __FUNCT__
1054 #define __FUNCT__ "PCBDDCSubSchursCreate"
1055 PetscErrorCode PCBDDCSubSchursCreate(PCBDDCSubSchurs *sub_schurs)
1056 {
1057   PCBDDCSubSchurs schurs_ctx;
1058   PetscErrorCode  ierr;
1059 
1060   PetscFunctionBegin;
1061   ierr = PetscNew(&schurs_ctx);CHKERRQ(ierr);
1062   schurs_ctx->n_subs = 0;
1063   *sub_schurs = schurs_ctx;
1064   PetscFunctionReturn(0);
1065 }
1066 
1067 #undef __FUNCT__
1068 #define __FUNCT__ "PCBDDCSubSchursDestroy"
1069 PetscErrorCode PCBDDCSubSchursDestroy(PCBDDCSubSchurs *sub_schurs)
1070 {
1071   PetscErrorCode ierr;
1072 
1073   PetscFunctionBegin;
1074   ierr = PCBDDCSubSchursReset(*sub_schurs);CHKERRQ(ierr);
1075   ierr = PetscFree(*sub_schurs);CHKERRQ(ierr);
1076   PetscFunctionReturn(0);
1077 }
1078 
1079 #undef __FUNCT__
1080 #define __FUNCT__ "PCBDDCSubSchursReset"
1081 PetscErrorCode PCBDDCSubSchursReset(PCBDDCSubSchurs sub_schurs)
1082 {
1083   PetscInt       i;
1084   PetscErrorCode ierr;
1085 
1086   PetscFunctionBegin;
1087   ierr = MatDestroy(&sub_schurs->A);CHKERRQ(ierr);
1088   ierr = MatDestroy(&sub_schurs->S);CHKERRQ(ierr);
1089   ierr = ISDestroy(&sub_schurs->is_I);CHKERRQ(ierr);
1090   ierr = ISDestroy(&sub_schurs->is_B);CHKERRQ(ierr);
1091   ierr = ISLocalToGlobalMappingDestroy(&sub_schurs->l2gmap);CHKERRQ(ierr);
1092   ierr = ISLocalToGlobalMappingDestroy(&sub_schurs->BtoNmap);CHKERRQ(ierr);
1093   ierr = MatDestroy(&sub_schurs->S_Ej_all);CHKERRQ(ierr);
1094   ierr = MatDestroy(&sub_schurs->sum_S_Ej_all);CHKERRQ(ierr);
1095   ierr = MatDestroy(&sub_schurs->sum_S_Ej_inv_all);CHKERRQ(ierr);
1096   ierr = MatDestroy(&sub_schurs->sum_S_Ej_tilda_all);CHKERRQ(ierr);
1097   ierr = ISDestroy(&sub_schurs->is_Ej_all);CHKERRQ(ierr);
1098   ierr = ISDestroy(&sub_schurs->is_vertices);CHKERRQ(ierr);
1099   ierr = ISDestroy(&sub_schurs->is_dir);CHKERRQ(ierr);
1100   ierr = PetscBTDestroy(&sub_schurs->is_edge);CHKERRQ(ierr);
1101   ierr = PetscBTDestroy(&sub_schurs->computed_Stilda_subs);CHKERRQ(ierr);
1102   for (i=0;i<sub_schurs->n_subs;i++) {
1103     ierr = ISDestroy(&sub_schurs->is_subs[i]);CHKERRQ(ierr);
1104   }
1105   if (sub_schurs->n_subs) {
1106     ierr = PetscFree(sub_schurs->is_subs);CHKERRQ(ierr);
1107   }
1108   if (sub_schurs->reuse_mumps) {
1109     ierr = PCBDDCReuseMumpsReset(sub_schurs->reuse_mumps);CHKERRQ(ierr);
1110   }
1111   ierr = PetscFree(sub_schurs->reuse_mumps);CHKERRQ(ierr);
1112   sub_schurs->n_subs = 0;
1113   PetscFunctionReturn(0);
1114 }
1115 
1116 #undef __FUNCT__
1117 #define __FUNCT__ "PCBDDCAdjGetNextLayer_Private"
1118 PETSC_STATIC_INLINE PetscErrorCode PCBDDCAdjGetNextLayer_Private(PetscInt* queue_tip,PetscInt n_prev,PetscBT touched,PetscInt* xadj,PetscInt* adjncy,PetscInt* n_added)
1119 {
1120   PetscInt       i,j,n;
1121   PetscErrorCode ierr;
1122 
1123   PetscFunctionBegin;
1124   n = 0;
1125   for (i=-n_prev;i<0;i++) {
1126     PetscInt start_dof = queue_tip[i];
1127     for (j=xadj[start_dof];j<xadj[start_dof+1];j++) {
1128       PetscInt dof = adjncy[j];
1129       if (!PetscBTLookup(touched,dof)) {
1130         ierr = PetscBTSet(touched,dof);CHKERRQ(ierr);
1131         queue_tip[n] = dof;
1132         n++;
1133       }
1134     }
1135   }
1136   *n_added = n;
1137   PetscFunctionReturn(0);
1138 }
1139