xref: /petsc/src/mat/impls/baij/seq/baijfact3.c (revision 01a79839fc82a7dabb7a87cd2a8bb532c6bfa88d)
1 #define PETSCMAT_DLL
2 
3 /*
4     Factorization code for BAIJ format.
5 */
6 #include "../src/mat/impls/baij/seq/baij.h"
7 #include "../src/mat/blockinvert.h"
8 
9 #undef __FUNCT__
10 #define __FUNCT__ "MatSeqBAIJSetNumericFactorization"
11 /*
12    This is used to set the numeric factorization for both LU and ILU symbolic factorization
13 */
14 PetscErrorCode MatSeqBAIJSetNumericFactorization(Mat fact,PetscBool  natural)
15 {
16   PetscFunctionBegin;
17   if(natural){
18     switch (fact->rmap->bs){
19     case 1:
20       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1;
21       break;
22     case 2:
23       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering;
24       break;
25     case 3:
26       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering;
27       break;
28     case 4:
29       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering;
30       break;
31     case 5:
32        fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_NaturalOrdering;
33        break;
34     case 6:
35       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_NaturalOrdering;
36       break;
37     case 7:
38       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_NaturalOrdering;
39       break;
40     case 15:
41       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_15_NaturalOrdering;
42       break;
43     default:
44       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N;
45       break;
46     }
47   } else {
48     switch (fact->rmap->bs){
49     case 1:
50       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1;
51       break;
52     case 2:
53       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2;
54       break;
55     case 3:
56       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3;
57       break;
58     case 4:
59       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4;
60       break;
61     case 5:
62       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5;
63       break;
64     case 6:
65       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6;
66       break;
67     case 7:
68       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7;
69       break;
70     default:
71       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N;
72       break;
73     }
74   }
75   PetscFunctionReturn(0);
76 }
77 
78 #undef __FUNCT__
79 #define __FUNCT__ "MatSeqBAIJSetNumericFactorization_inplace"
80 PetscErrorCode MatSeqBAIJSetNumericFactorization_inplace(Mat inA,PetscBool  natural)
81 {
82   PetscFunctionBegin;
83   if (natural) {
84     switch (inA->rmap->bs) {
85     case 1:
86       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1_inplace;
87       break;
88     case 2:
89       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering_inplace;
90       break;
91     case 3:
92       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering_inplace;
93       break;
94     case 4:
95 #if defined(PETSC_USE_SCALAR_MAT_SINGLE)
96       {
97         PetscBool   sse_enabled_local;
98         PetscErrorCode ierr;
99         ierr = PetscSSEIsEnabled(inA->comm,&sse_enabled_local,PETSC_NULL);CHKERRQ(ierr);
100         if (sse_enabled_local) {
101 #  if defined(PETSC_HAVE_SSE)
102           int i,*AJ=a->j,nz=a->nz,n=a->mbs;
103           if (n==(unsigned short)n) {
104             unsigned short *aj=(unsigned short *)AJ;
105             for (i=0;i<nz;i++) {
106               aj[i] = (unsigned short)AJ[i];
107             }
108             inA->ops->setunfactored   = MatSetUnfactored_SeqBAIJ_4_NaturalOrdering_SSE_usj;
109             inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_SSE_usj;
110             ierr = PetscInfo(inA,"Using special SSE, in-place natural ordering, ushort j index factor BS=4\n");CHKERRQ(ierr);
111           } else {
112         /* Scale the column indices for easier indexing in MatSolve. */
113 /*            for (i=0;i<nz;i++) { */
114 /*              AJ[i] = AJ[i]*4; */
115 /*            } */
116             inA->ops->setunfactored   = MatSetUnfactored_SeqBAIJ_4_NaturalOrdering_SSE;
117             inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_SSE;
118             ierr = PetscInfo(inA,"Using special SSE, in-place natural ordering, int j index factor BS=4\n");CHKERRQ(ierr);
119           }
120 #  else
121         /* This should never be reached.  If so, problem in PetscSSEIsEnabled. */
122           SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"SSE Hardware unavailable");
123 #  endif
124         } else {
125           inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_inplace;
126         }
127       }
128 #else
129       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_inplace;
130 #endif
131       break;
132     case 5:
133       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_NaturalOrdering_inplace;
134       break;
135     case 6:
136       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_NaturalOrdering_inplace;
137       break;
138     case 7:
139       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_NaturalOrdering_inplace;
140       break;
141     default:
142       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N_inplace;
143       break;
144     }
145   } else {
146     switch (inA->rmap->bs) {
147     case 1:
148       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1_inplace;
149       break;
150     case 2:
151       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_inplace;
152       break;
153     case 3:
154       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_inplace;
155       break;
156     case 4:
157       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_inplace;
158       break;
159     case 5:
160       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_inplace;
161       break;
162     case 6:
163       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_inplace;
164       break;
165     case 7:
166       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_inplace;
167       break;
168     default:
169       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N_inplace;
170       break;
171     }
172   }
173   PetscFunctionReturn(0);
174 }
175 
176 /*
177     The symbolic factorization code is identical to that for AIJ format,
178   except for very small changes since this is now a SeqBAIJ datastructure.
179   NOT good code reuse.
180 */
181 #include "petscbt.h"
182 #include "../src/mat/utils/freespace.h"
183 
184 #undef __FUNCT__
185 #define __FUNCT__ "MatLUFactorSymbolic_SeqBAIJ"
186 PetscErrorCode MatLUFactorSymbolic_SeqBAIJ(Mat B,Mat A,IS isrow,IS iscol,const MatFactorInfo *info)
187 {
188   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data,*b;
189   PetscInt           n=a->mbs,bs = A->rmap->bs,bs2=a->bs2;
190   PetscBool          row_identity,col_identity,both_identity;
191   IS                 isicol;
192   PetscErrorCode     ierr;
193   const PetscInt     *r,*ic;
194   PetscInt           i,*ai=a->i,*aj=a->j;
195   PetscInt           *bi,*bj,*ajtmp;
196   PetscInt           *bdiag,row,nnz,nzi,reallocs=0,nzbd,*im;
197   PetscReal          f;
198   PetscInt           nlnk,*lnk,k,**bi_ptr;
199   PetscFreeSpaceList free_space=PETSC_NULL,current_space=PETSC_NULL;
200   PetscBT            lnkbt;
201 
202   PetscFunctionBegin;
203   if (A->rmap->N != A->cmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"matrix must be square");
204   if (bs>1){  /* check shifttype */
205     if (info->shifttype == MAT_SHIFT_NONZERO || info->shifttype == MAT_SHIFT_POSITIVE_DEFINITE)
206       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only MAT_SHIFT_NONE and MAT_SHIFT_INBLOCKS are supported for BAIJ matrix");
207   }
208 
209   ierr = ISInvertPermutation(iscol,PETSC_DECIDE,&isicol);CHKERRQ(ierr);
210   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
211   ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
212 
213   /* get new row and diagonal pointers, must be allocated separately because they will be given to the Mat_SeqAIJ and freed separately */
214   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
215   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bdiag);CHKERRQ(ierr);
216   bi[0] = bdiag[0] = 0;
217 
218   /* linked list for storing column indices of the active row */
219   nlnk = n + 1;
220   ierr = PetscLLCreate(n,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
221 
222   ierr = PetscMalloc2(n+1,PetscInt**,&bi_ptr,n+1,PetscInt,&im);CHKERRQ(ierr);
223 
224   /* initial FreeSpace size is f*(ai[n]+1) */
225   f = info->fill;
226   ierr = PetscFreeSpaceGet((PetscInt)(f*(ai[n]+1)),&free_space);CHKERRQ(ierr);
227   current_space = free_space;
228 
229   for (i=0; i<n; i++) {
230     /* copy previous fill into linked list */
231     nzi = 0;
232     nnz = ai[r[i]+1] - ai[r[i]];
233     if (!nnz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_MAT_LU_ZRPVT,"Empty row in matrix: row in original ordering %D in permuted ordering %D",r[i],i);
234     ajtmp = aj + ai[r[i]];
235     ierr = PetscLLAddPerm(nnz,ajtmp,ic,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
236     nzi += nlnk;
237 
238     /* add pivot rows into linked list */
239     row = lnk[n];
240     while (row < i) {
241       nzbd    = bdiag[row] + 1; /* num of entries in the row with column index <= row */
242       ajtmp   = bi_ptr[row] + nzbd; /* points to the entry next to the diagonal */
243       ierr = PetscLLAddSortedLU(ajtmp,row,nlnk,lnk,lnkbt,i,nzbd,im);CHKERRQ(ierr);
244       nzi += nlnk;
245       row  = lnk[row];
246     }
247     bi[i+1] = bi[i] + nzi;
248     im[i]   = nzi;
249 
250     /* mark bdiag */
251     nzbd = 0;
252     nnz  = nzi;
253     k    = lnk[n];
254     while (nnz-- && k < i){
255       nzbd++;
256       k = lnk[k];
257     }
258     bdiag[i] = nzbd; /* note : bdaig[i] = nnzL as input for PetscFreeSpaceContiguous_LU() */
259 
260     /* if free space is not available, make more free space */
261     if (current_space->local_remaining<nzi) {
262       nnz = 2*(n - i)*nzi; /* estimated and max additional space needed */
263       ierr = PetscFreeSpaceGet(nnz,&current_space);CHKERRQ(ierr);
264       reallocs++;
265     }
266 
267     /* copy data into free space, then initialize lnk */
268     ierr = PetscLLClean(n,n,nzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
269     bi_ptr[i] = current_space->array;
270     current_space->array           += nzi;
271     current_space->local_used      += nzi;
272     current_space->local_remaining -= nzi;
273   }
274 
275   ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
276   ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
277 
278   /* copy free_space into bj and free free_space; set bi, bj, bdiag in new datastructure; */
279   ierr = PetscMalloc((bi[n]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
280   ierr = PetscFreeSpaceContiguous_LU(&free_space,bj,n,bi,bdiag);CHKERRQ(ierr);
281   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
282   ierr = PetscFree2(bi_ptr,im);CHKERRQ(ierr);
283 
284   /* put together the new matrix */
285   ierr = MatSeqBAIJSetPreallocation_SeqBAIJ(B,bs,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
286   ierr = PetscLogObjectParent(B,isicol);CHKERRQ(ierr);
287   b    = (Mat_SeqBAIJ*)(B)->data;
288   b->free_a       = PETSC_TRUE;
289   b->free_ij      = PETSC_TRUE;
290   b->singlemalloc = PETSC_FALSE;
291   ierr          = PetscMalloc((bdiag[0]+1)*sizeof(MatScalar)*bs2,&b->a);CHKERRQ(ierr);
292   b->j          = bj;
293   b->i          = bi;
294   b->diag       = bdiag;
295   b->free_diag  = PETSC_TRUE;
296   b->ilen       = 0;
297   b->imax       = 0;
298   b->row        = isrow;
299   b->col        = iscol;
300   b->pivotinblocks = (info->pivotinblocks) ? PETSC_TRUE : PETSC_FALSE;
301   ierr          = PetscObjectReference((PetscObject)isrow);CHKERRQ(ierr);
302   ierr          = PetscObjectReference((PetscObject)iscol);CHKERRQ(ierr);
303   b->icol       = isicol;
304   ierr = PetscMalloc((bs*n+bs)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
305   ierr = PetscLogObjectMemory(B,(bdiag[0]+1)*(sizeof(PetscInt)+sizeof(PetscScalar)*bs2));CHKERRQ(ierr);
306 
307   b->maxnz = b->nz = bdiag[0]+1;
308   B->factortype            =  MAT_FACTOR_LU;
309   B->info.factor_mallocs   = reallocs;
310   B->info.fill_ratio_given = f;
311 
312   if (ai[n] != 0) {
313     B->info.fill_ratio_needed = ((PetscReal)(bdiag[0]+1))/((PetscReal)ai[n]);
314   } else {
315     B->info.fill_ratio_needed = 0.0;
316   }
317 #if defined(PETSC_USE_INFO)
318   if (ai[n] != 0) {
319     PetscReal af = B->info.fill_ratio_needed;
320     ierr = PetscInfo3(A,"Reallocs %D Fill ratio:given %G needed %G\n",reallocs,f,af);CHKERRQ(ierr);
321     ierr = PetscInfo1(A,"Run with -pc_factor_fill %G or use \n",af);CHKERRQ(ierr);
322     ierr = PetscInfo1(A,"PCFactorSetFill(pc,%G);\n",af);CHKERRQ(ierr);
323     ierr = PetscInfo(A,"for best performance.\n");CHKERRQ(ierr);
324   } else {
325     ierr = PetscInfo(A,"Empty matrix\n");CHKERRQ(ierr);
326   }
327 #endif
328 
329   ierr = ISIdentity(isrow,&row_identity);CHKERRQ(ierr);
330   ierr = ISIdentity(iscol,&col_identity);CHKERRQ(ierr);
331   both_identity = (PetscBool) (row_identity && col_identity);
332   ierr = MatSeqBAIJSetNumericFactorization(B,both_identity);CHKERRQ(ierr);
333   PetscFunctionReturn(0);
334  }
335 
336 #undef __FUNCT__
337 #define __FUNCT__ "MatLUFactorSymbolic_SeqBAIJ_inplace"
338 PetscErrorCode MatLUFactorSymbolic_SeqBAIJ_inplace(Mat B,Mat A,IS isrow,IS iscol,const MatFactorInfo *info)
339 {
340   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data,*b;
341   PetscInt           n=a->mbs,bs = A->rmap->bs,bs2=a->bs2;
342   PetscBool          row_identity,col_identity,both_identity;
343   IS                 isicol;
344   PetscErrorCode     ierr;
345   const PetscInt     *r,*ic;
346   PetscInt           i,*ai=a->i,*aj=a->j;
347   PetscInt           *bi,*bj,*ajtmp;
348   PetscInt           *bdiag,row,nnz,nzi,reallocs=0,nzbd,*im;
349   PetscReal          f;
350   PetscInt           nlnk,*lnk,k,**bi_ptr;
351   PetscFreeSpaceList free_space=PETSC_NULL,current_space=PETSC_NULL;
352   PetscBT            lnkbt;
353 
354   PetscFunctionBegin;
355   if (A->rmap->N != A->cmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"matrix must be square");
356   ierr = ISInvertPermutation(iscol,PETSC_DECIDE,&isicol);CHKERRQ(ierr);
357   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
358   ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
359 
360   /* get new row and diagonal pointers, must be allocated separately because they will be given to the Mat_SeqAIJ and freed separately */
361   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
362   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bdiag);CHKERRQ(ierr);
363 
364   bi[0] = bdiag[0] = 0;
365 
366   /* linked list for storing column indices of the active row */
367   nlnk = n + 1;
368   ierr = PetscLLCreate(n,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
369 
370   ierr = PetscMalloc2(n+1,PetscInt**,&bi_ptr,n+1,PetscInt,&im);CHKERRQ(ierr);
371 
372   /* initial FreeSpace size is f*(ai[n]+1) */
373   f = info->fill;
374   ierr = PetscFreeSpaceGet((PetscInt)(f*(ai[n]+1)),&free_space);CHKERRQ(ierr);
375   current_space = free_space;
376 
377   for (i=0; i<n; i++) {
378     /* copy previous fill into linked list */
379     nzi = 0;
380     nnz = ai[r[i]+1] - ai[r[i]];
381     if (!nnz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_MAT_LU_ZRPVT,"Empty row in matrix: row in original ordering %D in permuted ordering %D",r[i],i);
382     ajtmp = aj + ai[r[i]];
383     ierr = PetscLLAddPerm(nnz,ajtmp,ic,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
384     nzi += nlnk;
385 
386     /* add pivot rows into linked list */
387     row = lnk[n];
388     while (row < i) {
389       nzbd    = bdiag[row] - bi[row] + 1; /* num of entries in the row with column index <= row */
390       ajtmp   = bi_ptr[row] + nzbd; /* points to the entry next to the diagonal */
391       ierr = PetscLLAddSortedLU(ajtmp,row,nlnk,lnk,lnkbt,i,nzbd,im);CHKERRQ(ierr);
392       nzi += nlnk;
393       row  = lnk[row];
394     }
395     bi[i+1] = bi[i] + nzi;
396     im[i]   = nzi;
397 
398     /* mark bdiag */
399     nzbd = 0;
400     nnz  = nzi;
401     k    = lnk[n];
402     while (nnz-- && k < i){
403       nzbd++;
404       k = lnk[k];
405     }
406     bdiag[i] = bi[i] + nzbd;
407 
408     /* if free space is not available, make more free space */
409     if (current_space->local_remaining<nzi) {
410       nnz = (n - i)*nzi; /* estimated and max additional space needed */
411       ierr = PetscFreeSpaceGet(nnz,&current_space);CHKERRQ(ierr);
412       reallocs++;
413     }
414 
415     /* copy data into free space, then initialize lnk */
416     ierr = PetscLLClean(n,n,nzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
417     bi_ptr[i] = current_space->array;
418     current_space->array           += nzi;
419     current_space->local_used      += nzi;
420     current_space->local_remaining -= nzi;
421   }
422 #if defined(PETSC_USE_INFO)
423   if (ai[n] != 0) {
424     PetscReal af = ((PetscReal)bi[n])/((PetscReal)ai[n]);
425     ierr = PetscInfo3(A,"Reallocs %D Fill ratio:given %G needed %G\n",reallocs,f,af);CHKERRQ(ierr);
426     ierr = PetscInfo1(A,"Run with -pc_factor_fill %G or use \n",af);CHKERRQ(ierr);
427     ierr = PetscInfo1(A,"PCFactorSetFill(pc,%G);\n",af);CHKERRQ(ierr);
428     ierr = PetscInfo(A,"for best performance.\n");CHKERRQ(ierr);
429   } else {
430     ierr = PetscInfo(A,"Empty matrix\n");CHKERRQ(ierr);
431   }
432 #endif
433 
434   ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
435   ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
436 
437   /* destroy list of free space and other temporary array(s) */
438   ierr = PetscMalloc((bi[n]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
439   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
440   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
441   ierr = PetscFree2(bi_ptr,im);CHKERRQ(ierr);
442 
443   /* put together the new matrix */
444   ierr = MatSeqBAIJSetPreallocation_SeqBAIJ(B,bs,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
445   ierr = PetscLogObjectParent(B,isicol);CHKERRQ(ierr);
446   b    = (Mat_SeqBAIJ*)(B)->data;
447   b->free_a       = PETSC_TRUE;
448   b->free_ij      = PETSC_TRUE;
449   b->singlemalloc = PETSC_FALSE;
450   ierr          = PetscMalloc((bi[n]+1)*sizeof(MatScalar)*bs2,&b->a);CHKERRQ(ierr);
451   b->j          = bj;
452   b->i          = bi;
453   b->diag       = bdiag;
454   b->free_diag  = PETSC_TRUE;
455   b->ilen       = 0;
456   b->imax       = 0;
457   b->row        = isrow;
458   b->col        = iscol;
459   b->pivotinblocks = (info->pivotinblocks) ? PETSC_TRUE : PETSC_FALSE;
460   ierr          = PetscObjectReference((PetscObject)isrow);CHKERRQ(ierr);
461   ierr          = PetscObjectReference((PetscObject)iscol);CHKERRQ(ierr);
462   b->icol       = isicol;
463   ierr = PetscMalloc((bs*n+bs)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
464   ierr = PetscLogObjectMemory(B,(bi[n]-n)*(sizeof(PetscInt)+sizeof(PetscScalar)*bs2));CHKERRQ(ierr);
465 
466   b->maxnz = b->nz = bi[n] ;
467   (B)->factortype            =  MAT_FACTOR_LU;
468   (B)->info.factor_mallocs   = reallocs;
469   (B)->info.fill_ratio_given = f;
470 
471   if (ai[n] != 0) {
472     (B)->info.fill_ratio_needed = ((PetscReal)bi[n])/((PetscReal)ai[n]);
473   } else {
474     (B)->info.fill_ratio_needed = 0.0;
475   }
476 
477   ierr = ISIdentity(isrow,&row_identity);CHKERRQ(ierr);
478   ierr = ISIdentity(iscol,&col_identity);CHKERRQ(ierr);
479   both_identity = (PetscBool) (row_identity && col_identity);
480   ierr = MatSeqBAIJSetNumericFactorization_inplace(B,both_identity);CHKERRQ(ierr);
481   PetscFunctionReturn(0);
482  }
483 
484