xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 9bd13290d3b152bd11ec9e0616f24f2a797cea31)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
3 #include <petsc-private/vecimpl.h>
4 #include <petscblaslapack.h>
5 #include <petscsf.h>
6 
7 /*MC
8    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
9 
10    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
11    and MATMPIAIJ otherwise.  As a result, for single process communicators,
12   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
13   for communicators controlling multiple processes.  It is recommended that you call both of
14   the above preallocation routines for simplicity.
15 
16    Options Database Keys:
17 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
18 
19   Developer Notes: Subclasses include MATAIJCUSP, MATAIJCUSPARSE, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
20    enough exist.
21 
22   Level: beginner
23 
24 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ,MATMPIAIJ
25 M*/
26 
27 /*MC
28    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
29 
30    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
31    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
32    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
33   for communicators controlling multiple processes.  It is recommended that you call both of
34   the above preallocation routines for simplicity.
35 
36    Options Database Keys:
37 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
38 
39   Level: beginner
40 
41 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
42 M*/
43 
44 #undef __FUNCT__
45 #define __FUNCT__ "MatFindNonzeroRows_MPIAIJ"
46 PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M,IS *keptrows)
47 {
48   PetscErrorCode  ierr;
49   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
50   Mat_SeqAIJ      *a   = (Mat_SeqAIJ*)mat->A->data;
51   Mat_SeqAIJ      *b   = (Mat_SeqAIJ*)mat->B->data;
52   const PetscInt  *ia,*ib;
53   const MatScalar *aa,*bb;
54   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
55   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
56 
57   PetscFunctionBegin;
58   *keptrows = 0;
59   ia        = a->i;
60   ib        = b->i;
61   for (i=0; i<m; i++) {
62     na = ia[i+1] - ia[i];
63     nb = ib[i+1] - ib[i];
64     if (!na && !nb) {
65       cnt++;
66       goto ok1;
67     }
68     aa = a->a + ia[i];
69     for (j=0; j<na; j++) {
70       if (aa[j] != 0.0) goto ok1;
71     }
72     bb = b->a + ib[i];
73     for (j=0; j <nb; j++) {
74       if (bb[j] != 0.0) goto ok1;
75     }
76     cnt++;
77 ok1:;
78   }
79   ierr = MPI_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPIU_SUM,PetscObjectComm((PetscObject)M));CHKERRQ(ierr);
80   if (!n0rows) PetscFunctionReturn(0);
81   ierr = PetscMalloc1((M->rmap->n-cnt),&rows);CHKERRQ(ierr);
82   cnt  = 0;
83   for (i=0; i<m; i++) {
84     na = ia[i+1] - ia[i];
85     nb = ib[i+1] - ib[i];
86     if (!na && !nb) continue;
87     aa = a->a + ia[i];
88     for (j=0; j<na;j++) {
89       if (aa[j] != 0.0) {
90         rows[cnt++] = rstart + i;
91         goto ok2;
92       }
93     }
94     bb = b->a + ib[i];
95     for (j=0; j<nb; j++) {
96       if (bb[j] != 0.0) {
97         rows[cnt++] = rstart + i;
98         goto ok2;
99       }
100     }
101 ok2:;
102   }
103   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
104   PetscFunctionReturn(0);
105 }
106 
107 #undef __FUNCT__
108 #define __FUNCT__ "MatDiagonalSet_MPIAIJ"
109 PetscErrorCode  MatDiagonalSet_MPIAIJ(Mat Y,Vec D,InsertMode is)
110 {
111   PetscErrorCode    ierr;
112   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*) Y->data;
113 
114   PetscFunctionBegin;
115   if (Y->assembled && Y->rmap->rstart == Y->cmap->rstart && Y->rmap->rend == Y->cmap->rend) {
116     ierr = MatDiagonalSet(aij->A,D,is);CHKERRQ(ierr);
117   } else {
118     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
119   }
120   PetscFunctionReturn(0);
121 }
122 
123 
124 #undef __FUNCT__
125 #define __FUNCT__ "MatFindZeroDiagonals_MPIAIJ"
126 PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M,IS *zrows)
127 {
128   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)M->data;
129   PetscErrorCode ierr;
130   PetscInt       i,rstart,nrows,*rows;
131 
132   PetscFunctionBegin;
133   *zrows = NULL;
134   ierr   = MatFindZeroDiagonals_SeqAIJ_Private(aij->A,&nrows,&rows);CHKERRQ(ierr);
135   ierr   = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
136   for (i=0; i<nrows; i++) rows[i] += rstart;
137   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),nrows,rows,PETSC_OWN_POINTER,zrows);CHKERRQ(ierr);
138   PetscFunctionReturn(0);
139 }
140 
141 #undef __FUNCT__
142 #define __FUNCT__ "MatGetColumnNorms_MPIAIJ"
143 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
144 {
145   PetscErrorCode ierr;
146   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
147   PetscInt       i,n,*garray = aij->garray;
148   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
149   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
150   PetscReal      *work;
151 
152   PetscFunctionBegin;
153   ierr = MatGetSize(A,NULL,&n);CHKERRQ(ierr);
154   ierr = PetscCalloc1(n,&work);CHKERRQ(ierr);
155   if (type == NORM_2) {
156     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
157       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
158     }
159     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
160       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
161     }
162   } else if (type == NORM_1) {
163     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
164       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
165     }
166     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
167       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
168     }
169   } else if (type == NORM_INFINITY) {
170     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
171       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
172     }
173     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
174       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
175     }
176 
177   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONG,"Unknown NormType");
178   if (type == NORM_INFINITY) {
179     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
180   } else {
181     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
182   }
183   ierr = PetscFree(work);CHKERRQ(ierr);
184   if (type == NORM_2) {
185     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
186   }
187   PetscFunctionReturn(0);
188 }
189 
190 #undef __FUNCT__
191 #define __FUNCT__ "MatDistribute_MPIAIJ"
192 /*
193     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
194     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
195 
196     Only for square matrices
197 
198     Used by a preconditioner, hence PETSC_EXTERN
199 */
200 PETSC_EXTERN PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
201 {
202   PetscMPIInt    rank,size;
203   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz = 0,*gmataj,cnt,row,*ld,bses[2];
204   PetscErrorCode ierr;
205   Mat            mat;
206   Mat_SeqAIJ     *gmata;
207   PetscMPIInt    tag;
208   MPI_Status     status;
209   PetscBool      aij;
210   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
211 
212   PetscFunctionBegin;
213   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
214   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
215   if (!rank) {
216     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
217     if (!aij) SETERRQ1(PetscObjectComm((PetscObject)gmat),PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
218   }
219   if (reuse == MAT_INITIAL_MATRIX) {
220     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
221     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
222     ierr = MatGetBlockSizes(gmat,&bses[0],&bses[1]);CHKERRQ(ierr);
223     ierr = MPI_Bcast(bses,2,MPIU_INT,0,comm);CHKERRQ(ierr);
224     ierr = MatSetBlockSizes(mat,bses[0],bses[1]);CHKERRQ(ierr);
225     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
226     ierr = PetscMalloc1((size+1),&rowners);CHKERRQ(ierr);
227     ierr = PetscMalloc2(m,&dlens,m,&olens);CHKERRQ(ierr);
228     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
229 
230     rowners[0] = 0;
231     for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
232     rstart = rowners[rank];
233     rend   = rowners[rank+1];
234     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
235     if (!rank) {
236       gmata = (Mat_SeqAIJ*) gmat->data;
237       /* send row lengths to all processors */
238       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
239       for (i=1; i<size; i++) {
240         ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
241       }
242       /* determine number diagonal and off-diagonal counts */
243       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
244       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
245       jj   = 0;
246       for (i=0; i<m; i++) {
247         for (j=0; j<dlens[i]; j++) {
248           if (gmata->j[jj] < rstart) ld[i]++;
249           if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
250           jj++;
251         }
252       }
253       /* send column indices to other processes */
254       for (i=1; i<size; i++) {
255         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
256         ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
257         ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
258       }
259 
260       /* send numerical values to other processes */
261       for (i=1; i<size; i++) {
262         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
263         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
264       }
265       gmataa = gmata->a;
266       gmataj = gmata->j;
267 
268     } else {
269       /* receive row lengths */
270       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
271       /* receive column indices */
272       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
273       ierr = PetscMalloc2(nz,&gmataa,nz,&gmataj);CHKERRQ(ierr);
274       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
275       /* determine number diagonal and off-diagonal counts */
276       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
277       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
278       jj   = 0;
279       for (i=0; i<m; i++) {
280         for (j=0; j<dlens[i]; j++) {
281           if (gmataj[jj] < rstart) ld[i]++;
282           if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
283           jj++;
284         }
285       }
286       /* receive numerical values */
287       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
288       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
289     }
290     /* set preallocation */
291     for (i=0; i<m; i++) {
292       dlens[i] -= olens[i];
293     }
294     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
295     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
296 
297     for (i=0; i<m; i++) {
298       dlens[i] += olens[i];
299     }
300     cnt = 0;
301     for (i=0; i<m; i++) {
302       row  = rstart + i;
303       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
304       cnt += dlens[i];
305     }
306     if (rank) {
307       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
308     }
309     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
310     ierr = PetscFree(rowners);CHKERRQ(ierr);
311 
312     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
313 
314     *inmat = mat;
315   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
316     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
317     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
318     mat  = *inmat;
319     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
320     if (!rank) {
321       /* send numerical values to other processes */
322       gmata  = (Mat_SeqAIJ*) gmat->data;
323       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
324       gmataa = gmata->a;
325       for (i=1; i<size; i++) {
326         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
327         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
328       }
329       nz = gmata->i[rowners[1]]-gmata->i[rowners[0]];
330     } else {
331       /* receive numerical values from process 0*/
332       nz   = Ad->nz + Ao->nz;
333       ierr = PetscMalloc1(nz,&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
334       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
335     }
336     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
337     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
338     ad = Ad->a;
339     ao = Ao->a;
340     if (mat->rmap->n) {
341       i  = 0;
342       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
343       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
344     }
345     for (i=1; i<mat->rmap->n; i++) {
346       nz = Ao->i[i] - Ao->i[i-1] - ld[i-1] + ld[i]; ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
347       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
348     }
349     i--;
350     if (mat->rmap->n) {
351       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
352     }
353     if (rank) {
354       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
355     }
356   }
357   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
358   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
359   PetscFunctionReturn(0);
360 }
361 
362 /*
363   Local utility routine that creates a mapping from the global column
364 number to the local number in the off-diagonal part of the local
365 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
366 a slightly higher hash table cost; without it it is not scalable (each processor
367 has an order N integer array but is fast to acess.
368 */
369 #undef __FUNCT__
370 #define __FUNCT__ "MatCreateColmap_MPIAIJ_Private"
371 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
372 {
373   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
374   PetscErrorCode ierr;
375   PetscInt       n = aij->B->cmap->n,i;
376 
377   PetscFunctionBegin;
378   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
379 #if defined(PETSC_USE_CTABLE)
380   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
381   for (i=0; i<n; i++) {
382     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
383   }
384 #else
385   ierr = PetscCalloc1((mat->cmap->N+1),&aij->colmap);CHKERRQ(ierr);
386   ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N+1)*sizeof(PetscInt));CHKERRQ(ierr);
387   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
388 #endif
389   PetscFunctionReturn(0);
390 }
391 
392 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv) \
393 { \
394     if (col <= lastcol1)  low1 = 0;     \
395     else                 high1 = nrow1; \
396     lastcol1 = col;\
397     while (high1-low1 > 5) { \
398       t = (low1+high1)/2; \
399       if (rp1[t] > col) high1 = t; \
400       else              low1  = t; \
401     } \
402       for (_i=low1; _i<high1; _i++) { \
403         if (rp1[_i] > col) break; \
404         if (rp1[_i] == col) { \
405           if (addv == ADD_VALUES) ap1[_i] += value;   \
406           else                    ap1[_i] = value; \
407           goto a_noinsert; \
408         } \
409       }  \
410       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
411       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}                \
412       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
413       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
414       N = nrow1++ - 1; a->nz++; high1++; \
415       /* shift up all the later entries in this row */ \
416       for (ii=N; ii>=_i; ii--) { \
417         rp1[ii+1] = rp1[ii]; \
418         ap1[ii+1] = ap1[ii]; \
419       } \
420       rp1[_i] = col;  \
421       ap1[_i] = value;  \
422       A->nonzerostate++;\
423       a_noinsert: ; \
424       ailen[row] = nrow1; \
425 }
426 
427 
428 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv) \
429   { \
430     if (col <= lastcol2) low2 = 0;                        \
431     else high2 = nrow2;                                   \
432     lastcol2 = col;                                       \
433     while (high2-low2 > 5) {                              \
434       t = (low2+high2)/2;                                 \
435       if (rp2[t] > col) high2 = t;                        \
436       else             low2  = t;                         \
437     }                                                     \
438     for (_i=low2; _i<high2; _i++) {                       \
439       if (rp2[_i] > col) break;                           \
440       if (rp2[_i] == col) {                               \
441         if (addv == ADD_VALUES) ap2[_i] += value;         \
442         else                    ap2[_i] = value;          \
443         goto b_noinsert;                                  \
444       }                                                   \
445     }                                                     \
446     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
447     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}                        \
448     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
449     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
450     N = nrow2++ - 1; b->nz++; high2++;                    \
451     /* shift up all the later entries in this row */      \
452     for (ii=N; ii>=_i; ii--) {                            \
453       rp2[ii+1] = rp2[ii];                                \
454       ap2[ii+1] = ap2[ii];                                \
455     }                                                     \
456     rp2[_i] = col;                                        \
457     ap2[_i] = value;                                      \
458     B->nonzerostate++;                                    \
459     b_noinsert: ;                                         \
460     bilen[row] = nrow2;                                   \
461   }
462 
463 #undef __FUNCT__
464 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
465 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
466 {
467   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
468   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
469   PetscErrorCode ierr;
470   PetscInt       l,*garray = mat->garray,diag;
471 
472   PetscFunctionBegin;
473   /* code only works for square matrices A */
474 
475   /* find size of row to the left of the diagonal part */
476   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
477   row  = row - diag;
478   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
479     if (garray[b->j[b->i[row]+l]] > diag) break;
480   }
481   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
482 
483   /* diagonal part */
484   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
485 
486   /* right of diagonal part */
487   ierr = PetscMemcpy(b->a+b->i[row]+l,v+l+a->i[row+1]-a->i[row],(b->i[row+1]-b->i[row]-l)*sizeof(PetscScalar));CHKERRQ(ierr);
488   PetscFunctionReturn(0);
489 }
490 
491 #undef __FUNCT__
492 #define __FUNCT__ "MatSetValues_MPIAIJ"
493 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
494 {
495   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
496   PetscScalar    value;
497   PetscErrorCode ierr;
498   PetscInt       i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
499   PetscInt       cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
500   PetscBool      roworiented = aij->roworiented;
501 
502   /* Some Variables required in the macro */
503   Mat        A                 = aij->A;
504   Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
505   PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
506   MatScalar  *aa               = a->a;
507   PetscBool  ignorezeroentries = a->ignorezeroentries;
508   Mat        B                 = aij->B;
509   Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
510   PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
511   MatScalar  *ba               = b->a;
512 
513   PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
514   PetscInt  nonew;
515   MatScalar *ap1,*ap2;
516 
517   PetscFunctionBegin;
518   for (i=0; i<m; i++) {
519     if (im[i] < 0) continue;
520 #if defined(PETSC_USE_DEBUG)
521     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
522 #endif
523     if (im[i] >= rstart && im[i] < rend) {
524       row      = im[i] - rstart;
525       lastcol1 = -1;
526       rp1      = aj + ai[row];
527       ap1      = aa + ai[row];
528       rmax1    = aimax[row];
529       nrow1    = ailen[row];
530       low1     = 0;
531       high1    = nrow1;
532       lastcol2 = -1;
533       rp2      = bj + bi[row];
534       ap2      = ba + bi[row];
535       rmax2    = bimax[row];
536       nrow2    = bilen[row];
537       low2     = 0;
538       high2    = nrow2;
539 
540       for (j=0; j<n; j++) {
541         if (roworiented) value = v[i*n+j];
542         else             value = v[i+j*m];
543         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
544         if (in[j] >= cstart && in[j] < cend) {
545           col   = in[j] - cstart;
546           nonew = a->nonew;
547           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
548         } else if (in[j] < 0) continue;
549 #if defined(PETSC_USE_DEBUG)
550         else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
551 #endif
552         else {
553           if (mat->was_assembled) {
554             if (!aij->colmap) {
555               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
556             }
557 #if defined(PETSC_USE_CTABLE)
558             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
559             col--;
560 #else
561             col = aij->colmap[in[j]] - 1;
562 #endif
563             if (col < 0 && !((Mat_SeqAIJ*)(aij->B->data))->nonew) {
564               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
565               col  =  in[j];
566               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
567               B     = aij->B;
568               b     = (Mat_SeqAIJ*)B->data;
569               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
570               rp2   = bj + bi[row];
571               ap2   = ba + bi[row];
572               rmax2 = bimax[row];
573               nrow2 = bilen[row];
574               low2  = 0;
575               high2 = nrow2;
576               bm    = aij->B->rmap->n;
577               ba    = b->a;
578             } else if (col < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", im[i], in[j]);
579           } else col = in[j];
580           nonew = b->nonew;
581           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
582         }
583       }
584     } else {
585       if (mat->nooffprocentries) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Setting off process row %D even though MatSetOption(,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) was set",im[i]);
586       if (!aij->donotstash) {
587         mat->assembled = PETSC_FALSE;
588         if (roworiented) {
589           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
590         } else {
591           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
592         }
593       }
594     }
595   }
596   PetscFunctionReturn(0);
597 }
598 
599 #undef __FUNCT__
600 #define __FUNCT__ "MatGetValues_MPIAIJ"
601 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
602 {
603   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
604   PetscErrorCode ierr;
605   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
606   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
607 
608   PetscFunctionBegin;
609   for (i=0; i<m; i++) {
610     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
611     if (idxm[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",idxm[i],mat->rmap->N-1);
612     if (idxm[i] >= rstart && idxm[i] < rend) {
613       row = idxm[i] - rstart;
614       for (j=0; j<n; j++) {
615         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
616         if (idxn[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",idxn[j],mat->cmap->N-1);
617         if (idxn[j] >= cstart && idxn[j] < cend) {
618           col  = idxn[j] - cstart;
619           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
620         } else {
621           if (!aij->colmap) {
622             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
623           }
624 #if defined(PETSC_USE_CTABLE)
625           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
626           col--;
627 #else
628           col = aij->colmap[idxn[j]] - 1;
629 #endif
630           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
631           else {
632             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
633           }
634         }
635       }
636     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
637   }
638   PetscFunctionReturn(0);
639 }
640 
641 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
642 
643 #undef __FUNCT__
644 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
645 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
646 {
647   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
648   PetscErrorCode ierr;
649   PetscInt       nstash,reallocs;
650   InsertMode     addv;
651 
652   PetscFunctionBegin;
653   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(0);
654 
655   /* make sure all processors are either in INSERTMODE or ADDMODE */
656   ierr = MPI_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
657   if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
658   mat->insertmode = addv; /* in case this processor had no cache */
659 
660   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
661   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
662   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
663   PetscFunctionReturn(0);
664 }
665 
666 #undef __FUNCT__
667 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
668 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
669 {
670   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
671   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)aij->A->data;
672   PetscErrorCode ierr;
673   PetscMPIInt    n;
674   PetscInt       i,j,rstart,ncols,flg;
675   PetscInt       *row,*col;
676   PetscBool      other_disassembled;
677   PetscScalar    *val;
678   InsertMode     addv = mat->insertmode;
679 
680   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */
681 
682   PetscFunctionBegin;
683   if (!aij->donotstash && !mat->nooffprocentries) {
684     while (1) {
685       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
686       if (!flg) break;
687 
688       for (i=0; i<n; ) {
689         /* Now identify the consecutive vals belonging to the same row */
690         for (j=i,rstart=row[j]; j<n; j++) {
691           if (row[j] != rstart) break;
692         }
693         if (j < n) ncols = j-i;
694         else       ncols = n-i;
695         /* Now assemble all these values with a single function call */
696         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
697 
698         i = j;
699       }
700     }
701     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
702   }
703   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
704   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
705 
706   /* determine if any processor has disassembled, if so we must
707      also disassemble ourselfs, in order that we may reassemble. */
708   /*
709      if nonzero structure of submatrix B cannot change then we know that
710      no processor disassembled thus we can skip this stuff
711   */
712   if (!((Mat_SeqAIJ*)aij->B->data)->nonew) {
713     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPIU_BOOL,MPI_PROD,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
714     if (mat->was_assembled && !other_disassembled) {
715       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
716     }
717   }
718   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
719     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
720   }
721   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
722   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
723   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
724 
725   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
726 
727   aij->rowvalues = 0;
728 
729   /* used by MatAXPY() */
730   a->xtoy = 0; ((Mat_SeqAIJ*)aij->B->data)->xtoy = 0;   /* b->xtoy = 0 */
731   a->XtoY = 0; ((Mat_SeqAIJ*)aij->B->data)->XtoY = 0;   /* b->XtoY = 0 */
732 
733   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
734   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
735 
736   /* if no new nonzero locations are allowed in matrix then only set the matrix state the first time through */
737   if ((!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) || !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
738     PetscObjectState state = aij->A->nonzerostate + aij->B->nonzerostate;
739     ierr = MPI_Allreduce(&state,&mat->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
740   }
741   PetscFunctionReturn(0);
742 }
743 
744 #undef __FUNCT__
745 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
746 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
747 {
748   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
749   PetscErrorCode ierr;
750 
751   PetscFunctionBegin;
752   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
753   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
754   PetscFunctionReturn(0);
755 }
756 
757 #undef __FUNCT__
758 #define __FUNCT__ "MatZeroRows_MPIAIJ"
759 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
760 {
761   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
762   PetscInt      *owners = A->rmap->range;
763   PetscInt       n      = A->rmap->n;
764   PetscSF        sf;
765   PetscInt      *lrows;
766   PetscSFNode   *rrows;
767   PetscInt       r, p = 0, len = 0;
768   PetscErrorCode ierr;
769 
770   PetscFunctionBegin;
771   /* Create SF where leaves are input rows and roots are owned rows */
772   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
773   for (r = 0; r < n; ++r) lrows[r] = -1;
774   if (!A->nooffproczerorows) {ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);}
775   for (r = 0; r < N; ++r) {
776     const PetscInt idx   = rows[r];
777     if (idx < 0 || A->rmap->N <= idx) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row %D out of range [0,%D)",idx,A->rmap->N);
778     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
779       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
780     }
781     if (A->nooffproczerorows) {
782       if (p != mat->rank) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"MAT_NO_OFF_PROC_ZERO_ROWS set, but row %D is not owned by rank %d",idx,mat->rank);
783       lrows[len++] = idx - owners[p];
784     } else {
785       rrows[r].rank = p;
786       rrows[r].index = rows[r] - owners[p];
787     }
788   }
789   if (!A->nooffproczerorows) {
790     ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
791     ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
792     /* Collect flags for rows to be zeroed */
793     ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
794     ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
795     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
796     /* Compress and put in row numbers */
797     for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
798   }
799   /* fix right hand side if needed */
800   if (x && b) {
801     const PetscScalar *xx;
802     PetscScalar       *bb;
803 
804     ierr = VecGetArrayRead(x, &xx);CHKERRQ(ierr);
805     ierr = VecGetArray(b, &bb);CHKERRQ(ierr);
806     for (r = 0; r < len; ++r) bb[lrows[r]] = diag*xx[lrows[r]];
807     ierr = VecRestoreArrayRead(x, &xx);CHKERRQ(ierr);
808     ierr = VecRestoreArray(b, &bb);CHKERRQ(ierr);
809   }
810   /* Must zero l->B before l->A because the (diag) case below may put values into l->B*/
811   ierr = MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
812   if ((diag != 0.0) && (mat->A->rmap->N == mat->A->cmap->N)) {
813     ierr = MatZeroRows(mat->A, len, lrows, diag, NULL, NULL);CHKERRQ(ierr);
814   } else if (diag != 0.0) {
815     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
816     if (((Mat_SeqAIJ *) mat->A->data)->nonew) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "MatZeroRows() on rectangular matrices cannot be used with the Mat options\nMAT_NEW_NONZERO_LOCATIONS,MAT_NEW_NONZERO_LOCATION_ERR,MAT_NEW_NONZERO_ALLOCATION_ERR");
817     for (r = 0; r < len; ++r) {
818       const PetscInt row = lrows[r] + A->rmap->rstart;
819       ierr = MatSetValues(A, 1, &row, 1, &row, &diag, INSERT_VALUES);CHKERRQ(ierr);
820     }
821     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
822     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
823   } else {
824     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
825   }
826   ierr = PetscFree(lrows);CHKERRQ(ierr);
827 
828   /* only change matrix nonzero state if pattern was allowed to be changed */
829   if (!((Mat_SeqAIJ*)(mat->A->data))->keepnonzeropattern) {
830     PetscObjectState state = mat->A->nonzerostate + mat->B->nonzerostate;
831     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
832   }
833   PetscFunctionReturn(0);
834 }
835 
836 #undef __FUNCT__
837 #define __FUNCT__ "MatZeroRowsColumns_MPIAIJ"
838 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
839 {
840   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
841   PetscErrorCode    ierr;
842   PetscMPIInt       n = A->rmap->n;
843   PetscInt          i,j,r,m,p = 0,len = 0;
844   PetscInt          *lrows,*owners = A->rmap->range;
845   PetscSFNode       *rrows;
846   PetscSF           sf;
847   const PetscScalar *xx;
848   PetscScalar       *bb,*mask;
849   Vec               xmask,lmask;
850   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
851   const PetscInt    *aj, *ii,*ridx;
852   PetscScalar       *aa;
853 
854   PetscFunctionBegin;
855   /* Create SF where leaves are input rows and roots are owned rows */
856   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
857   for (r = 0; r < n; ++r) lrows[r] = -1;
858   ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);
859   for (r = 0; r < N; ++r) {
860     const PetscInt idx   = rows[r];
861     if (idx < 0 || A->rmap->N <= idx) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row %D out of range [0,%D)",idx,A->rmap->N);
862     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
863       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
864     }
865     rrows[r].rank  = p;
866     rrows[r].index = rows[r] - owners[p];
867   }
868   ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
869   ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
870   /* Collect flags for rows to be zeroed */
871   ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
872   ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
873   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
874   /* Compress and put in row numbers */
875   for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
876   /* zero diagonal part of matrix */
877   ierr = MatZeroRowsColumns(l->A,len,lrows,diag,x,b);CHKERRQ(ierr);
878   /* handle off diagonal part of matrix */
879   ierr = MatCreateVecs(A,&xmask,NULL);CHKERRQ(ierr);
880   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
881   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
882   for (i=0; i<len; i++) bb[lrows[i]] = 1;
883   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
884   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
885   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
886   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
887   if (x) {
888     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
889     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
890     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
891     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
892   }
893   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
894   /* remove zeroed rows of off diagonal matrix */
895   ii = aij->i;
896   for (i=0; i<len; i++) {
897     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
898   }
899   /* loop over all elements of off process part of matrix zeroing removed columns*/
900   if (aij->compressedrow.use) {
901     m    = aij->compressedrow.nrows;
902     ii   = aij->compressedrow.i;
903     ridx = aij->compressedrow.rindex;
904     for (i=0; i<m; i++) {
905       n  = ii[i+1] - ii[i];
906       aj = aij->j + ii[i];
907       aa = aij->a + ii[i];
908 
909       for (j=0; j<n; j++) {
910         if (PetscAbsScalar(mask[*aj])) {
911           if (b) bb[*ridx] -= *aa*xx[*aj];
912           *aa = 0.0;
913         }
914         aa++;
915         aj++;
916       }
917       ridx++;
918     }
919   } else { /* do not use compressed row format */
920     m = l->B->rmap->n;
921     for (i=0; i<m; i++) {
922       n  = ii[i+1] - ii[i];
923       aj = aij->j + ii[i];
924       aa = aij->a + ii[i];
925       for (j=0; j<n; j++) {
926         if (PetscAbsScalar(mask[*aj])) {
927           if (b) bb[i] -= *aa*xx[*aj];
928           *aa = 0.0;
929         }
930         aa++;
931         aj++;
932       }
933     }
934   }
935   if (x) {
936     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
937     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
938   }
939   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
940   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
941   ierr = PetscFree(lrows);CHKERRQ(ierr);
942 
943   /* only change matrix nonzero state if pattern was allowed to be changed */
944   if (!((Mat_SeqAIJ*)(l->A->data))->keepnonzeropattern) {
945     PetscObjectState state = l->A->nonzerostate + l->B->nonzerostate;
946     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
947   }
948   PetscFunctionReturn(0);
949 }
950 
951 #undef __FUNCT__
952 #define __FUNCT__ "MatMult_MPIAIJ"
953 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
954 {
955   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
956   PetscErrorCode ierr;
957   PetscInt       nt;
958 
959   PetscFunctionBegin;
960   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
961   if (nt != A->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Incompatible partition of A (%D) and xx (%D)",A->cmap->n,nt);
962   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
963   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
964   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
965   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
966   PetscFunctionReturn(0);
967 }
968 
969 #undef __FUNCT__
970 #define __FUNCT__ "MatMultDiagonalBlock_MPIAIJ"
971 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
972 {
973   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
974   PetscErrorCode ierr;
975 
976   PetscFunctionBegin;
977   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
978   PetscFunctionReturn(0);
979 }
980 
981 #undef __FUNCT__
982 #define __FUNCT__ "MatMultAdd_MPIAIJ"
983 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
984 {
985   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
986   PetscErrorCode ierr;
987 
988   PetscFunctionBegin;
989   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
990   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
991   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
992   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
993   PetscFunctionReturn(0);
994 }
995 
996 #undef __FUNCT__
997 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
998 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
999 {
1000   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1001   PetscErrorCode ierr;
1002   PetscBool      merged;
1003 
1004   PetscFunctionBegin;
1005   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
1006   /* do nondiagonal part */
1007   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1008   if (!merged) {
1009     /* send it on its way */
1010     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1011     /* do local part */
1012     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1013     /* receive remote parts: note this assumes the values are not actually */
1014     /* added in yy until the next line, */
1015     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1016   } else {
1017     /* do local part */
1018     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1019     /* send it on its way */
1020     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1021     /* values actually were received in the Begin() but we need to call this nop */
1022     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1023   }
1024   PetscFunctionReturn(0);
1025 }
1026 
1027 #undef __FUNCT__
1028 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
1029 PetscErrorCode  MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1030 {
1031   MPI_Comm       comm;
1032   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ*) Amat->data, *Bij;
1033   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1034   IS             Me,Notme;
1035   PetscErrorCode ierr;
1036   PetscInt       M,N,first,last,*notme,i;
1037   PetscMPIInt    size;
1038 
1039   PetscFunctionBegin;
1040   /* Easy test: symmetric diagonal block */
1041   Bij  = (Mat_MPIAIJ*) Bmat->data; Bdia = Bij->A;
1042   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1043   if (!*f) PetscFunctionReturn(0);
1044   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1045   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1046   if (size == 1) PetscFunctionReturn(0);
1047 
1048   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
1049   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1050   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1051   ierr = PetscMalloc1((N-last+first),&notme);CHKERRQ(ierr);
1052   for (i=0; i<first; i++) notme[i] = i;
1053   for (i=last; i<M; i++) notme[i-last+first] = i;
1054   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1055   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1056   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1057   Aoff = Aoffs[0];
1058   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1059   Boff = Boffs[0];
1060   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1061   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1062   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1063   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1064   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1065   ierr = PetscFree(notme);CHKERRQ(ierr);
1066   PetscFunctionReturn(0);
1067 }
1068 
1069 #undef __FUNCT__
1070 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
1071 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1072 {
1073   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1074   PetscErrorCode ierr;
1075 
1076   PetscFunctionBegin;
1077   /* do nondiagonal part */
1078   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1079   /* send it on its way */
1080   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1081   /* do local part */
1082   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1083   /* receive remote parts */
1084   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1085   PetscFunctionReturn(0);
1086 }
1087 
1088 /*
1089   This only works correctly for square matrices where the subblock A->A is the
1090    diagonal block
1091 */
1092 #undef __FUNCT__
1093 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
1094 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1095 {
1096   PetscErrorCode ierr;
1097   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1098 
1099   PetscFunctionBegin;
1100   if (A->rmap->N != A->cmap->N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1101   if (A->rmap->rstart != A->cmap->rstart || A->rmap->rend != A->cmap->rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"row partition must equal col partition");
1102   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1103   PetscFunctionReturn(0);
1104 }
1105 
1106 #undef __FUNCT__
1107 #define __FUNCT__ "MatScale_MPIAIJ"
1108 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1109 {
1110   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1111   PetscErrorCode ierr;
1112 
1113   PetscFunctionBegin;
1114   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1115   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1116   PetscFunctionReturn(0);
1117 }
1118 
1119 #undef __FUNCT__
1120 #define __FUNCT__ "MatDestroy_Redundant"
1121 PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1122 {
1123   PetscErrorCode ierr;
1124   Mat_Redundant  *redund = *redundant;
1125   PetscInt       i;
1126 
1127   PetscFunctionBegin;
1128   *redundant = NULL;
1129   if (redund){
1130     if (redund->matseq) { /* via MatGetSubMatrices()  */
1131       ierr = ISDestroy(&redund->isrow);CHKERRQ(ierr);
1132       ierr = ISDestroy(&redund->iscol);CHKERRQ(ierr);
1133       ierr = MatDestroy(&redund->matseq[0]);CHKERRQ(ierr);
1134       ierr = PetscFree(redund->matseq);CHKERRQ(ierr);
1135     } else {
1136       ierr = PetscFree2(redund->send_rank,redund->recv_rank);CHKERRQ(ierr);
1137       ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
1138       ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
1139       for (i=0; i<redund->nrecvs; i++) {
1140         ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
1141         ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
1142       }
1143       ierr = PetscFree4(redund->sbuf_nz,redund->rbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
1144     }
1145 
1146     if (redund->subcomm) {
1147       ierr = PetscCommDestroy(&redund->subcomm);CHKERRQ(ierr);
1148     }
1149     ierr = PetscFree(redund);CHKERRQ(ierr);
1150   }
1151   PetscFunctionReturn(0);
1152 }
1153 
1154 #undef __FUNCT__
1155 #define __FUNCT__ "MatDestroy_MPIAIJ"
1156 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1157 {
1158   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1159   PetscErrorCode ierr;
1160 
1161   PetscFunctionBegin;
1162 #if defined(PETSC_USE_LOG)
1163   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1164 #endif
1165   ierr = MatDestroy_Redundant(&mat->redundant);CHKERRQ(ierr);
1166   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1167   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1168   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1169   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1170 #if defined(PETSC_USE_CTABLE)
1171   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1172 #else
1173   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1174 #endif
1175   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1176   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1177   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1178   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1179   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1180   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1181 
1182   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1183   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C",NULL);CHKERRQ(ierr);
1184   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C",NULL);CHKERRQ(ierr);
1185   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C",NULL);CHKERRQ(ierr);
1186   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C",NULL);CHKERRQ(ierr);
1187   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C",NULL);CHKERRQ(ierr);
1188   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C",NULL);CHKERRQ(ierr);
1189   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C",NULL);CHKERRQ(ierr);
1190   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C",NULL);CHKERRQ(ierr);
1191 #if defined(PETSC_HAVE_ELEMENTAL)
1192   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_elemental_C",NULL);CHKERRQ(ierr);
1193 #endif
1194   PetscFunctionReturn(0);
1195 }
1196 
1197 #undef __FUNCT__
1198 #define __FUNCT__ "MatView_MPIAIJ_Binary"
1199 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1200 {
1201   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1202   Mat_SeqAIJ     *A   = (Mat_SeqAIJ*)aij->A->data;
1203   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)aij->B->data;
1204   PetscErrorCode ierr;
1205   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
1206   int            fd;
1207   PetscInt       nz,header[4],*row_lengths,*range=0,rlen,i;
1208   PetscInt       nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz = 0;
1209   PetscScalar    *column_values;
1210   PetscInt       message_count,flowcontrolcount;
1211   FILE           *file;
1212 
1213   PetscFunctionBegin;
1214   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1215   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
1216   nz   = A->nz + B->nz;
1217   if (!rank) {
1218     header[0] = MAT_FILE_CLASSID;
1219     header[1] = mat->rmap->N;
1220     header[2] = mat->cmap->N;
1221 
1222     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1223     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1224     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1225     /* get largest number of rows any processor has */
1226     rlen  = mat->rmap->n;
1227     range = mat->rmap->range;
1228     for (i=1; i<size; i++) rlen = PetscMax(rlen,range[i+1] - range[i]);
1229   } else {
1230     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1231     rlen = mat->rmap->n;
1232   }
1233 
1234   /* load up the local row counts */
1235   ierr = PetscMalloc1((rlen+1),&row_lengths);CHKERRQ(ierr);
1236   for (i=0; i<mat->rmap->n; i++) row_lengths[i] = A->i[i+1] - A->i[i] + B->i[i+1] - B->i[i];
1237 
1238   /* store the row lengths to the file */
1239   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1240   if (!rank) {
1241     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1242     for (i=1; i<size; i++) {
1243       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1244       rlen = range[i+1] - range[i];
1245       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1246       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1247     }
1248     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1249   } else {
1250     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1251     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1252     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1253   }
1254   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1255 
1256   /* load up the local column indices */
1257   nzmax = nz; /* th processor needs space a largest processor needs */
1258   ierr  = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1259   ierr  = PetscMalloc1((nzmax+1),&column_indices);CHKERRQ(ierr);
1260   cnt   = 0;
1261   for (i=0; i<mat->rmap->n; i++) {
1262     for (j=B->i[i]; j<B->i[i+1]; j++) {
1263       if ((col = garray[B->j[j]]) > cstart) break;
1264       column_indices[cnt++] = col;
1265     }
1266     for (k=A->i[i]; k<A->i[i+1]; k++) column_indices[cnt++] = A->j[k] + cstart;
1267     for (; j<B->i[i+1]; j++) column_indices[cnt++] = garray[B->j[j]];
1268   }
1269   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1270 
1271   /* store the column indices to the file */
1272   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1273   if (!rank) {
1274     MPI_Status status;
1275     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1276     for (i=1; i<size; i++) {
1277       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1278       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1279       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1280       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1281       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1282     }
1283     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1284   } else {
1285     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1286     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1287     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1288     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1289   }
1290   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1291 
1292   /* load up the local column values */
1293   ierr = PetscMalloc1((nzmax+1),&column_values);CHKERRQ(ierr);
1294   cnt  = 0;
1295   for (i=0; i<mat->rmap->n; i++) {
1296     for (j=B->i[i]; j<B->i[i+1]; j++) {
1297       if (garray[B->j[j]] > cstart) break;
1298       column_values[cnt++] = B->a[j];
1299     }
1300     for (k=A->i[i]; k<A->i[i+1]; k++) column_values[cnt++] = A->a[k];
1301     for (; j<B->i[i+1]; j++) column_values[cnt++] = B->a[j];
1302   }
1303   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1304 
1305   /* store the column values to the file */
1306   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1307   if (!rank) {
1308     MPI_Status status;
1309     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1310     for (i=1; i<size; i++) {
1311       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1312       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1313       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1314       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1315       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1316     }
1317     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1318   } else {
1319     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1320     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1321     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1322     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1323   }
1324   ierr = PetscFree(column_values);CHKERRQ(ierr);
1325 
1326   ierr = PetscViewerBinaryGetInfoPointer(viewer,&file);CHKERRQ(ierr);
1327   if (file) fprintf(file,"-matload_block_size %d\n",(int)PetscAbs(mat->rmap->bs));
1328   PetscFunctionReturn(0);
1329 }
1330 
1331 #include <petscdraw.h>
1332 #undef __FUNCT__
1333 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1334 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1335 {
1336   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1337   PetscErrorCode    ierr;
1338   PetscMPIInt       rank = aij->rank,size = aij->size;
1339   PetscBool         isdraw,iascii,isbinary;
1340   PetscViewer       sviewer;
1341   PetscViewerFormat format;
1342 
1343   PetscFunctionBegin;
1344   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1345   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1346   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1347   if (iascii) {
1348     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1349     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1350       MatInfo   info;
1351       PetscBool inodes;
1352 
1353       ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1354       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1355       ierr = MatInodeGetInodeSizes(aij->A,NULL,(PetscInt**)&inodes,NULL);CHKERRQ(ierr);
1356       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
1357       if (!inodes) {
1358         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1359                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1360       } else {
1361         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1362                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1363       }
1364       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1365       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1366       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1367       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1368       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1369       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
1370       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1371       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1372       PetscFunctionReturn(0);
1373     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1374       PetscInt inodecount,inodelimit,*inodes;
1375       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1376       if (inodes) {
1377         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1378       } else {
1379         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1380       }
1381       PetscFunctionReturn(0);
1382     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1383       PetscFunctionReturn(0);
1384     }
1385   } else if (isbinary) {
1386     if (size == 1) {
1387       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1388       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1389     } else {
1390       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1391     }
1392     PetscFunctionReturn(0);
1393   } else if (isdraw) {
1394     PetscDraw draw;
1395     PetscBool isnull;
1396     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1397     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1398   }
1399 
1400   {
1401     /* assemble the entire matrix onto first processor. */
1402     Mat        A;
1403     Mat_SeqAIJ *Aloc;
1404     PetscInt   M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1405     MatScalar  *a;
1406 
1407     ierr = MatCreate(PetscObjectComm((PetscObject)mat),&A);CHKERRQ(ierr);
1408     if (!rank) {
1409       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1410     } else {
1411       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1412     }
1413     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1414     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1415     ierr = MatMPIAIJSetPreallocation(A,0,NULL,0,NULL);CHKERRQ(ierr);
1416     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1417     ierr = PetscLogObjectParent((PetscObject)mat,(PetscObject)A);CHKERRQ(ierr);
1418 
1419     /* copy over the A part */
1420     Aloc = (Mat_SeqAIJ*)aij->A->data;
1421     m    = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1422     row  = mat->rmap->rstart;
1423     for (i=0; i<ai[m]; i++) aj[i] += mat->cmap->rstart;
1424     for (i=0; i<m; i++) {
1425       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1426       row++;
1427       a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1428     }
1429     aj = Aloc->j;
1430     for (i=0; i<ai[m]; i++) aj[i] -= mat->cmap->rstart;
1431 
1432     /* copy over the B part */
1433     Aloc = (Mat_SeqAIJ*)aij->B->data;
1434     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1435     row  = mat->rmap->rstart;
1436     ierr = PetscMalloc1((ai[m]+1),&cols);CHKERRQ(ierr);
1437     ct   = cols;
1438     for (i=0; i<ai[m]; i++) cols[i] = aij->garray[aj[i]];
1439     for (i=0; i<m; i++) {
1440       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1441       row++;
1442       a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1443     }
1444     ierr = PetscFree(ct);CHKERRQ(ierr);
1445     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1446     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1447     /*
1448        Everyone has to call to draw the matrix since the graphics waits are
1449        synchronized across all processors that share the PetscDraw object
1450     */
1451     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1452     if (!rank) {
1453       ierr = MatView_SeqAIJ(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1454     }
1455     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1456     ierr = MatDestroy(&A);CHKERRQ(ierr);
1457   }
1458   PetscFunctionReturn(0);
1459 }
1460 
1461 #undef __FUNCT__
1462 #define __FUNCT__ "MatView_MPIAIJ"
1463 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1464 {
1465   PetscErrorCode ierr;
1466   PetscBool      iascii,isdraw,issocket,isbinary;
1467 
1468   PetscFunctionBegin;
1469   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1470   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1471   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1472   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1473   if (iascii || isdraw || isbinary || issocket) {
1474     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1475   }
1476   PetscFunctionReturn(0);
1477 }
1478 
1479 #undef __FUNCT__
1480 #define __FUNCT__ "MatSOR_MPIAIJ"
1481 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1482 {
1483   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1484   PetscErrorCode ierr;
1485   Vec            bb1 = 0;
1486   PetscBool      hasop;
1487 
1488   PetscFunctionBegin;
1489   if (flag == SOR_APPLY_UPPER) {
1490     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1491     PetscFunctionReturn(0);
1492   }
1493 
1494   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1495     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1496   }
1497 
1498   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1499     if (flag & SOR_ZERO_INITIAL_GUESS) {
1500       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1501       its--;
1502     }
1503 
1504     while (its--) {
1505       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1506       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1507 
1508       /* update rhs: bb1 = bb - B*x */
1509       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1510       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1511 
1512       /* local sweep */
1513       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1514     }
1515   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1516     if (flag & SOR_ZERO_INITIAL_GUESS) {
1517       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1518       its--;
1519     }
1520     while (its--) {
1521       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1522       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1523 
1524       /* update rhs: bb1 = bb - B*x */
1525       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1526       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1527 
1528       /* local sweep */
1529       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1530     }
1531   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1532     if (flag & SOR_ZERO_INITIAL_GUESS) {
1533       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1534       its--;
1535     }
1536     while (its--) {
1537       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1538       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1539 
1540       /* update rhs: bb1 = bb - B*x */
1541       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1542       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1543 
1544       /* local sweep */
1545       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1546     }
1547   } else if (flag & SOR_EISENSTAT) {
1548     Vec xx1;
1549 
1550     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1551     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1552 
1553     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1554     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1555     if (!mat->diag) {
1556       ierr = MatCreateVecs(matin,&mat->diag,NULL);CHKERRQ(ierr);
1557       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1558     }
1559     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1560     if (hasop) {
1561       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1562     } else {
1563       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1564     }
1565     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1566 
1567     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1568 
1569     /* local sweep */
1570     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1571     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1572     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1573   } else SETERRQ(PetscObjectComm((PetscObject)matin),PETSC_ERR_SUP,"Parallel SOR not supported");
1574 
1575   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1576   PetscFunctionReturn(0);
1577 }
1578 
1579 #undef __FUNCT__
1580 #define __FUNCT__ "MatPermute_MPIAIJ"
1581 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1582 {
1583   Mat            aA,aB,Aperm;
1584   const PetscInt *rwant,*cwant,*gcols,*ai,*bi,*aj,*bj;
1585   PetscScalar    *aa,*ba;
1586   PetscInt       i,j,m,n,ng,anz,bnz,*dnnz,*onnz,*tdnnz,*tonnz,*rdest,*cdest,*work,*gcdest;
1587   PetscSF        rowsf,sf;
1588   IS             parcolp = NULL;
1589   PetscBool      done;
1590   PetscErrorCode ierr;
1591 
1592   PetscFunctionBegin;
1593   ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
1594   ierr = ISGetIndices(rowp,&rwant);CHKERRQ(ierr);
1595   ierr = ISGetIndices(colp,&cwant);CHKERRQ(ierr);
1596   ierr = PetscMalloc3(PetscMax(m,n),&work,m,&rdest,n,&cdest);CHKERRQ(ierr);
1597 
1598   /* Invert row permutation to find out where my rows should go */
1599   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&rowsf);CHKERRQ(ierr);
1600   ierr = PetscSFSetGraphLayout(rowsf,A->rmap,A->rmap->n,NULL,PETSC_OWN_POINTER,rwant);CHKERRQ(ierr);
1601   ierr = PetscSFSetFromOptions(rowsf);CHKERRQ(ierr);
1602   for (i=0; i<m; i++) work[i] = A->rmap->rstart + i;
1603   ierr = PetscSFReduceBegin(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1604   ierr = PetscSFReduceEnd(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1605 
1606   /* Invert column permutation to find out where my columns should go */
1607   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1608   ierr = PetscSFSetGraphLayout(sf,A->cmap,A->cmap->n,NULL,PETSC_OWN_POINTER,cwant);CHKERRQ(ierr);
1609   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1610   for (i=0; i<n; i++) work[i] = A->cmap->rstart + i;
1611   ierr = PetscSFReduceBegin(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1612   ierr = PetscSFReduceEnd(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1613   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1614 
1615   ierr = ISRestoreIndices(rowp,&rwant);CHKERRQ(ierr);
1616   ierr = ISRestoreIndices(colp,&cwant);CHKERRQ(ierr);
1617   ierr = MatMPIAIJGetSeqAIJ(A,&aA,&aB,&gcols);CHKERRQ(ierr);
1618 
1619   /* Find out where my gcols should go */
1620   ierr = MatGetSize(aB,NULL,&ng);CHKERRQ(ierr);
1621   ierr = PetscMalloc1(ng,&gcdest);CHKERRQ(ierr);
1622   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1623   ierr = PetscSFSetGraphLayout(sf,A->cmap,ng,NULL,PETSC_OWN_POINTER,gcols);CHKERRQ(ierr);
1624   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1625   ierr = PetscSFBcastBegin(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1626   ierr = PetscSFBcastEnd(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1627   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1628 
1629   ierr = PetscCalloc4(m,&dnnz,m,&onnz,m,&tdnnz,m,&tonnz);CHKERRQ(ierr);
1630   ierr = MatGetRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1631   ierr = MatGetRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1632   for (i=0; i<m; i++) {
1633     PetscInt row = rdest[i],rowner;
1634     ierr = PetscLayoutFindOwner(A->rmap,row,&rowner);CHKERRQ(ierr);
1635     for (j=ai[i]; j<ai[i+1]; j++) {
1636       PetscInt cowner,col = cdest[aj[j]];
1637       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr); /* Could build an index for the columns to eliminate this search */
1638       if (rowner == cowner) dnnz[i]++;
1639       else onnz[i]++;
1640     }
1641     for (j=bi[i]; j<bi[i+1]; j++) {
1642       PetscInt cowner,col = gcdest[bj[j]];
1643       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr);
1644       if (rowner == cowner) dnnz[i]++;
1645       else onnz[i]++;
1646     }
1647   }
1648   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1649   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1650   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1651   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1652   ierr = PetscSFDestroy(&rowsf);CHKERRQ(ierr);
1653 
1654   ierr = MatCreateAIJ(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,0,tdnnz,0,tonnz,&Aperm);CHKERRQ(ierr);
1655   ierr = MatSeqAIJGetArray(aA,&aa);CHKERRQ(ierr);
1656   ierr = MatSeqAIJGetArray(aB,&ba);CHKERRQ(ierr);
1657   for (i=0; i<m; i++) {
1658     PetscInt *acols = dnnz,*bcols = onnz; /* Repurpose now-unneeded arrays */
1659     PetscInt j0,rowlen;
1660     rowlen = ai[i+1] - ai[i];
1661     for (j0=j=0; j<rowlen; j0=j) { /* rowlen could be larger than number of rows m, so sum in batches */
1662       for ( ; j<PetscMin(rowlen,j0+m); j++) acols[j-j0] = cdest[aj[ai[i]+j]];
1663       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,acols,aa+ai[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1664     }
1665     rowlen = bi[i+1] - bi[i];
1666     for (j0=j=0; j<rowlen; j0=j) {
1667       for ( ; j<PetscMin(rowlen,j0+m); j++) bcols[j-j0] = gcdest[bj[bi[i]+j]];
1668       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,bcols,ba+bi[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1669     }
1670   }
1671   ierr = MatAssemblyBegin(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1672   ierr = MatAssemblyEnd(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1673   ierr = MatRestoreRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1674   ierr = MatRestoreRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1675   ierr = MatSeqAIJRestoreArray(aA,&aa);CHKERRQ(ierr);
1676   ierr = MatSeqAIJRestoreArray(aB,&ba);CHKERRQ(ierr);
1677   ierr = PetscFree4(dnnz,onnz,tdnnz,tonnz);CHKERRQ(ierr);
1678   ierr = PetscFree3(work,rdest,cdest);CHKERRQ(ierr);
1679   ierr = PetscFree(gcdest);CHKERRQ(ierr);
1680   if (parcolp) {ierr = ISDestroy(&colp);CHKERRQ(ierr);}
1681   *B = Aperm;
1682   PetscFunctionReturn(0);
1683 }
1684 
1685 #undef __FUNCT__
1686 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1687 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1688 {
1689   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1690   Mat            A    = mat->A,B = mat->B;
1691   PetscErrorCode ierr;
1692   PetscReal      isend[5],irecv[5];
1693 
1694   PetscFunctionBegin;
1695   info->block_size = 1.0;
1696   ierr             = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1697 
1698   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1699   isend[3] = info->memory;  isend[4] = info->mallocs;
1700 
1701   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1702 
1703   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1704   isend[3] += info->memory;  isend[4] += info->mallocs;
1705   if (flag == MAT_LOCAL) {
1706     info->nz_used      = isend[0];
1707     info->nz_allocated = isend[1];
1708     info->nz_unneeded  = isend[2];
1709     info->memory       = isend[3];
1710     info->mallocs      = isend[4];
1711   } else if (flag == MAT_GLOBAL_MAX) {
1712     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1713 
1714     info->nz_used      = irecv[0];
1715     info->nz_allocated = irecv[1];
1716     info->nz_unneeded  = irecv[2];
1717     info->memory       = irecv[3];
1718     info->mallocs      = irecv[4];
1719   } else if (flag == MAT_GLOBAL_SUM) {
1720     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1721 
1722     info->nz_used      = irecv[0];
1723     info->nz_allocated = irecv[1];
1724     info->nz_unneeded  = irecv[2];
1725     info->memory       = irecv[3];
1726     info->mallocs      = irecv[4];
1727   }
1728   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1729   info->fill_ratio_needed = 0;
1730   info->factor_mallocs    = 0;
1731   PetscFunctionReturn(0);
1732 }
1733 
1734 #undef __FUNCT__
1735 #define __FUNCT__ "MatSetOption_MPIAIJ"
1736 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool flg)
1737 {
1738   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1739   PetscErrorCode ierr;
1740 
1741   PetscFunctionBegin;
1742   switch (op) {
1743   case MAT_NEW_NONZERO_LOCATIONS:
1744   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1745   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1746   case MAT_KEEP_NONZERO_PATTERN:
1747   case MAT_NEW_NONZERO_LOCATION_ERR:
1748   case MAT_USE_INODES:
1749   case MAT_IGNORE_ZERO_ENTRIES:
1750     MatCheckPreallocated(A,1);
1751     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1752     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1753     break;
1754   case MAT_ROW_ORIENTED:
1755     a->roworiented = flg;
1756 
1757     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1758     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1759     break;
1760   case MAT_NEW_DIAGONALS:
1761     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1762     break;
1763   case MAT_IGNORE_OFF_PROC_ENTRIES:
1764     a->donotstash = flg;
1765     break;
1766   case MAT_SPD:
1767     A->spd_set = PETSC_TRUE;
1768     A->spd     = flg;
1769     if (flg) {
1770       A->symmetric                  = PETSC_TRUE;
1771       A->structurally_symmetric     = PETSC_TRUE;
1772       A->symmetric_set              = PETSC_TRUE;
1773       A->structurally_symmetric_set = PETSC_TRUE;
1774     }
1775     break;
1776   case MAT_SYMMETRIC:
1777     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1778     break;
1779   case MAT_STRUCTURALLY_SYMMETRIC:
1780     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1781     break;
1782   case MAT_HERMITIAN:
1783     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1784     break;
1785   case MAT_SYMMETRY_ETERNAL:
1786     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1787     break;
1788   default:
1789     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1790   }
1791   PetscFunctionReturn(0);
1792 }
1793 
1794 #undef __FUNCT__
1795 #define __FUNCT__ "MatGetRow_MPIAIJ"
1796 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1797 {
1798   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1799   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1800   PetscErrorCode ierr;
1801   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1802   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1803   PetscInt       *cmap,*idx_p;
1804 
1805   PetscFunctionBegin;
1806   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1807   mat->getrowactive = PETSC_TRUE;
1808 
1809   if (!mat->rowvalues && (idx || v)) {
1810     /*
1811         allocate enough space to hold information from the longest row.
1812     */
1813     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1814     PetscInt   max = 1,tmp;
1815     for (i=0; i<matin->rmap->n; i++) {
1816       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1817       if (max < tmp) max = tmp;
1818     }
1819     ierr = PetscMalloc2(max,&mat->rowvalues,max,&mat->rowindices);CHKERRQ(ierr);
1820   }
1821 
1822   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1823   lrow = row - rstart;
1824 
1825   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1826   if (!v)   {pvA = 0; pvB = 0;}
1827   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1828   ierr  = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1829   ierr  = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1830   nztot = nzA + nzB;
1831 
1832   cmap = mat->garray;
1833   if (v  || idx) {
1834     if (nztot) {
1835       /* Sort by increasing column numbers, assuming A and B already sorted */
1836       PetscInt imark = -1;
1837       if (v) {
1838         *v = v_p = mat->rowvalues;
1839         for (i=0; i<nzB; i++) {
1840           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1841           else break;
1842         }
1843         imark = i;
1844         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1845         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1846       }
1847       if (idx) {
1848         *idx = idx_p = mat->rowindices;
1849         if (imark > -1) {
1850           for (i=0; i<imark; i++) {
1851             idx_p[i] = cmap[cworkB[i]];
1852           }
1853         } else {
1854           for (i=0; i<nzB; i++) {
1855             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1856             else break;
1857           }
1858           imark = i;
1859         }
1860         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1861         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1862       }
1863     } else {
1864       if (idx) *idx = 0;
1865       if (v)   *v   = 0;
1866     }
1867   }
1868   *nz  = nztot;
1869   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1870   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1871   PetscFunctionReturn(0);
1872 }
1873 
1874 #undef __FUNCT__
1875 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1876 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1877 {
1878   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1879 
1880   PetscFunctionBegin;
1881   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1882   aij->getrowactive = PETSC_FALSE;
1883   PetscFunctionReturn(0);
1884 }
1885 
1886 #undef __FUNCT__
1887 #define __FUNCT__ "MatNorm_MPIAIJ"
1888 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1889 {
1890   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)mat->data;
1891   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1892   PetscErrorCode ierr;
1893   PetscInt       i,j,cstart = mat->cmap->rstart;
1894   PetscReal      sum = 0.0;
1895   MatScalar      *v;
1896 
1897   PetscFunctionBegin;
1898   if (aij->size == 1) {
1899     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1900   } else {
1901     if (type == NORM_FROBENIUS) {
1902       v = amat->a;
1903       for (i=0; i<amat->nz; i++) {
1904         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1905       }
1906       v = bmat->a;
1907       for (i=0; i<bmat->nz; i++) {
1908         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1909       }
1910       ierr  = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1911       *norm = PetscSqrtReal(*norm);
1912     } else if (type == NORM_1) { /* max column norm */
1913       PetscReal *tmp,*tmp2;
1914       PetscInt  *jj,*garray = aij->garray;
1915       ierr  = PetscCalloc1((mat->cmap->N+1),&tmp);CHKERRQ(ierr);
1916       ierr  = PetscMalloc1((mat->cmap->N+1),&tmp2);CHKERRQ(ierr);
1917       *norm = 0.0;
1918       v     = amat->a; jj = amat->j;
1919       for (j=0; j<amat->nz; j++) {
1920         tmp[cstart + *jj++] += PetscAbsScalar(*v);  v++;
1921       }
1922       v = bmat->a; jj = bmat->j;
1923       for (j=0; j<bmat->nz; j++) {
1924         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1925       }
1926       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1927       for (j=0; j<mat->cmap->N; j++) {
1928         if (tmp2[j] > *norm) *norm = tmp2[j];
1929       }
1930       ierr = PetscFree(tmp);CHKERRQ(ierr);
1931       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1932     } else if (type == NORM_INFINITY) { /* max row norm */
1933       PetscReal ntemp = 0.0;
1934       for (j=0; j<aij->A->rmap->n; j++) {
1935         v   = amat->a + amat->i[j];
1936         sum = 0.0;
1937         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1938           sum += PetscAbsScalar(*v); v++;
1939         }
1940         v = bmat->a + bmat->i[j];
1941         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1942           sum += PetscAbsScalar(*v); v++;
1943         }
1944         if (sum > ntemp) ntemp = sum;
1945       }
1946       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1947     } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"No support for two norm");
1948   }
1949   PetscFunctionReturn(0);
1950 }
1951 
1952 #undef __FUNCT__
1953 #define __FUNCT__ "MatTranspose_MPIAIJ"
1954 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1955 {
1956   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1957   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1958   PetscErrorCode ierr;
1959   PetscInt       M      = A->rmap->N,N = A->cmap->N,ma,na,mb,nb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i;
1960   PetscInt       cstart = A->cmap->rstart,ncol;
1961   Mat            B;
1962   MatScalar      *array;
1963 
1964   PetscFunctionBegin;
1965   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1966 
1967   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n; nb = a->B->cmap->n;
1968   ai = Aloc->i; aj = Aloc->j;
1969   bi = Bloc->i; bj = Bloc->j;
1970   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1971     PetscInt             *d_nnz,*g_nnz,*o_nnz;
1972     PetscSFNode          *oloc;
1973     PETSC_UNUSED PetscSF sf;
1974 
1975     ierr = PetscMalloc4(na,&d_nnz,na,&o_nnz,nb,&g_nnz,nb,&oloc);CHKERRQ(ierr);
1976     /* compute d_nnz for preallocation */
1977     ierr = PetscMemzero(d_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1978     for (i=0; i<ai[ma]; i++) {
1979       d_nnz[aj[i]]++;
1980       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1981     }
1982     /* compute local off-diagonal contributions */
1983     ierr = PetscMemzero(g_nnz,nb*sizeof(PetscInt));CHKERRQ(ierr);
1984     for (i=0; i<bi[ma]; i++) g_nnz[bj[i]]++;
1985     /* map those to global */
1986     ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1987     ierr = PetscSFSetGraphLayout(sf,A->cmap,nb,NULL,PETSC_USE_POINTER,a->garray);CHKERRQ(ierr);
1988     ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1989     ierr = PetscMemzero(o_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1990     ierr = PetscSFReduceBegin(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1991     ierr = PetscSFReduceEnd(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1992     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1993 
1994     ierr = MatCreate(PetscObjectComm((PetscObject)A),&B);CHKERRQ(ierr);
1995     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1996     ierr = MatSetBlockSizes(B,PetscAbs(A->cmap->bs),PetscAbs(A->rmap->bs));CHKERRQ(ierr);
1997     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
1998     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
1999     ierr = PetscFree4(d_nnz,o_nnz,g_nnz,oloc);CHKERRQ(ierr);
2000   } else {
2001     B    = *matout;
2002     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
2003     for (i=0; i<ai[ma]; i++) aj[i] += cstart; /* global col index to be used by MatSetValues() */
2004   }
2005 
2006   /* copy over the A part */
2007   array = Aloc->a;
2008   row   = A->rmap->rstart;
2009   for (i=0; i<ma; i++) {
2010     ncol = ai[i+1]-ai[i];
2011     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2012     row++;
2013     array += ncol; aj += ncol;
2014   }
2015   aj = Aloc->j;
2016   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
2017 
2018   /* copy over the B part */
2019   ierr  = PetscCalloc1(bi[mb],&cols);CHKERRQ(ierr);
2020   array = Bloc->a;
2021   row   = A->rmap->rstart;
2022   for (i=0; i<bi[mb]; i++) cols[i] = a->garray[bj[i]];
2023   cols_tmp = cols;
2024   for (i=0; i<mb; i++) {
2025     ncol = bi[i+1]-bi[i];
2026     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2027     row++;
2028     array += ncol; cols_tmp += ncol;
2029   }
2030   ierr = PetscFree(cols);CHKERRQ(ierr);
2031 
2032   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2033   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2034   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
2035     *matout = B;
2036   } else {
2037     ierr = MatHeaderMerge(A,B);CHKERRQ(ierr);
2038   }
2039   PetscFunctionReturn(0);
2040 }
2041 
2042 #undef __FUNCT__
2043 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
2044 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
2045 {
2046   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2047   Mat            a    = aij->A,b = aij->B;
2048   PetscErrorCode ierr;
2049   PetscInt       s1,s2,s3;
2050 
2051   PetscFunctionBegin;
2052   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
2053   if (rr) {
2054     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
2055     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
2056     /* Overlap communication with computation. */
2057     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2058   }
2059   if (ll) {
2060     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
2061     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
2062     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2063   }
2064   /* scale  the diagonal block */
2065   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2066 
2067   if (rr) {
2068     /* Do a scatter end and then right scale the off-diagonal block */
2069     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2070     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2071   }
2072   PetscFunctionReturn(0);
2073 }
2074 
2075 #undef __FUNCT__
2076 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
2077 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2078 {
2079   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2080   PetscErrorCode ierr;
2081 
2082   PetscFunctionBegin;
2083   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2084   PetscFunctionReturn(0);
2085 }
2086 
2087 #undef __FUNCT__
2088 #define __FUNCT__ "MatEqual_MPIAIJ"
2089 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2090 {
2091   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2092   Mat            a,b,c,d;
2093   PetscBool      flg;
2094   PetscErrorCode ierr;
2095 
2096   PetscFunctionBegin;
2097   a = matA->A; b = matA->B;
2098   c = matB->A; d = matB->B;
2099 
2100   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2101   if (flg) {
2102     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2103   }
2104   ierr = MPI_Allreduce(&flg,flag,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
2105   PetscFunctionReturn(0);
2106 }
2107 
2108 #undef __FUNCT__
2109 #define __FUNCT__ "MatCopy_MPIAIJ"
2110 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2111 {
2112   PetscErrorCode ierr;
2113   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2114   Mat_MPIAIJ     *b = (Mat_MPIAIJ*)B->data;
2115 
2116   PetscFunctionBegin;
2117   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2118   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2119     /* because of the column compression in the off-processor part of the matrix a->B,
2120        the number of columns in a->B and b->B may be different, hence we cannot call
2121        the MatCopy() directly on the two parts. If need be, we can provide a more
2122        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2123        then copying the submatrices */
2124     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2125   } else {
2126     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2127     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2128   }
2129   PetscFunctionReturn(0);
2130 }
2131 
2132 #undef __FUNCT__
2133 #define __FUNCT__ "MatSetUp_MPIAIJ"
2134 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2135 {
2136   PetscErrorCode ierr;
2137 
2138   PetscFunctionBegin;
2139   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2140   PetscFunctionReturn(0);
2141 }
2142 
2143 /*
2144    Computes the number of nonzeros per row needed for preallocation when X and Y
2145    have different nonzero structure.
2146 */
2147 #undef __FUNCT__
2148 #define __FUNCT__ "MatAXPYGetPreallocation_MPIX_private"
2149 PetscErrorCode MatAXPYGetPreallocation_MPIX_private(PetscInt m,const PetscInt *xi,const PetscInt *xj,const PetscInt *xltog,const PetscInt *yi,const PetscInt *yj,const PetscInt *yltog,PetscInt *nnz)
2150 {
2151   PetscInt       i,j,k,nzx,nzy;
2152 
2153   PetscFunctionBegin;
2154   /* Set the number of nonzeros in the new matrix */
2155   for (i=0; i<m; i++) {
2156     const PetscInt *xjj = xj+xi[i],*yjj = yj+yi[i];
2157     nzx = xi[i+1] - xi[i];
2158     nzy = yi[i+1] - yi[i];
2159     nnz[i] = 0;
2160     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2161       for (; k<nzy && yltog[yjj[k]]<xltog[xjj[j]]; k++) nnz[i]++; /* Catch up to X */
2162       if (k<nzy && yltog[yjj[k]]==xltog[xjj[j]]) k++;             /* Skip duplicate */
2163       nnz[i]++;
2164     }
2165     for (; k<nzy; k++) nnz[i]++;
2166   }
2167   PetscFunctionReturn(0);
2168 }
2169 
2170 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2171 #undef __FUNCT__
2172 #define __FUNCT__ "MatAXPYGetPreallocation_MPIAIJ"
2173 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt *nnz)
2174 {
2175   PetscErrorCode ierr;
2176   PetscInt       m = Y->rmap->N;
2177   Mat_SeqAIJ     *x = (Mat_SeqAIJ*)X->data;
2178   Mat_SeqAIJ     *y = (Mat_SeqAIJ*)Y->data;
2179 
2180   PetscFunctionBegin;
2181   ierr = MatAXPYGetPreallocation_MPIX_private(m,x->i,x->j,xltog,y->i,y->j,yltog,nnz);CHKERRQ(ierr);
2182   PetscFunctionReturn(0);
2183 }
2184 
2185 #undef __FUNCT__
2186 #define __FUNCT__ "MatAXPY_MPIAIJ"
2187 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2188 {
2189   PetscErrorCode ierr;
2190   PetscInt       i;
2191   Mat_MPIAIJ     *xx = (Mat_MPIAIJ*)X->data,*yy = (Mat_MPIAIJ*)Y->data;
2192   PetscBLASInt   bnz,one=1;
2193   Mat_SeqAIJ     *x,*y;
2194 
2195   PetscFunctionBegin;
2196   if (str == SAME_NONZERO_PATTERN) {
2197     PetscScalar alpha = a;
2198     x    = (Mat_SeqAIJ*)xx->A->data;
2199     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2200     y    = (Mat_SeqAIJ*)yy->A->data;
2201     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2202     x    = (Mat_SeqAIJ*)xx->B->data;
2203     y    = (Mat_SeqAIJ*)yy->B->data;
2204     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2205     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2206     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2207   } else if (str == SUBSET_NONZERO_PATTERN) {
2208     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
2209 
2210     x = (Mat_SeqAIJ*)xx->B->data;
2211     y = (Mat_SeqAIJ*)yy->B->data;
2212     if (y->xtoy && y->XtoY != xx->B) {
2213       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
2214       ierr = MatDestroy(&y->XtoY);CHKERRQ(ierr);
2215     }
2216     if (!y->xtoy) { /* get xtoy */
2217       ierr    = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
2218       y->XtoY = xx->B;
2219       ierr    = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
2220     }
2221     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
2222     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2223   } else {
2224     Mat      B;
2225     PetscInt *nnz_d,*nnz_o;
2226     ierr = PetscMalloc1(yy->A->rmap->N,&nnz_d);CHKERRQ(ierr);
2227     ierr = PetscMalloc1(yy->B->rmap->N,&nnz_o);CHKERRQ(ierr);
2228     ierr = MatCreate(PetscObjectComm((PetscObject)Y),&B);CHKERRQ(ierr);
2229     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2230     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2231     ierr = MatSetBlockSizesFromMats(B,Y,Y);CHKERRQ(ierr);
2232     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2233     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2234     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2235     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2236     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2237     ierr = MatHeaderReplace(Y,B);CHKERRQ(ierr);
2238     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2239     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2240   }
2241   PetscFunctionReturn(0);
2242 }
2243 
2244 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2245 
2246 #undef __FUNCT__
2247 #define __FUNCT__ "MatConjugate_MPIAIJ"
2248 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2249 {
2250 #if defined(PETSC_USE_COMPLEX)
2251   PetscErrorCode ierr;
2252   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2253 
2254   PetscFunctionBegin;
2255   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2256   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2257 #else
2258   PetscFunctionBegin;
2259 #endif
2260   PetscFunctionReturn(0);
2261 }
2262 
2263 #undef __FUNCT__
2264 #define __FUNCT__ "MatRealPart_MPIAIJ"
2265 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2266 {
2267   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2268   PetscErrorCode ierr;
2269 
2270   PetscFunctionBegin;
2271   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2272   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2273   PetscFunctionReturn(0);
2274 }
2275 
2276 #undef __FUNCT__
2277 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
2278 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2279 {
2280   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2281   PetscErrorCode ierr;
2282 
2283   PetscFunctionBegin;
2284   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2285   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2286   PetscFunctionReturn(0);
2287 }
2288 
2289 #if defined(PETSC_HAVE_PBGL)
2290 
2291 #include <boost/parallel/mpi/bsp_process_group.hpp>
2292 #include <boost/graph/distributed/ilu_default_graph.hpp>
2293 #include <boost/graph/distributed/ilu_0_block.hpp>
2294 #include <boost/graph/distributed/ilu_preconditioner.hpp>
2295 #include <boost/graph/distributed/petsc/interface.hpp>
2296 #include <boost/multi_array.hpp>
2297 #include <boost/parallel/distributed_property_map->hpp>
2298 
2299 #undef __FUNCT__
2300 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
2301 /*
2302   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2303 */
2304 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
2305 {
2306   namespace petsc = boost::distributed::petsc;
2307 
2308   namespace graph_dist = boost::graph::distributed;
2309   using boost::graph::distributed::ilu_default::process_group_type;
2310   using boost::graph::ilu_permuted;
2311 
2312   PetscBool      row_identity, col_identity;
2313   PetscContainer c;
2314   PetscInt       m, n, M, N;
2315   PetscErrorCode ierr;
2316 
2317   PetscFunctionBegin;
2318   if (info->levels != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
2319   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
2320   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
2321   if (!row_identity || !col_identity) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
2322 
2323   process_group_type pg;
2324   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2325   lgraph_type  *lgraph_p   = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
2326   lgraph_type& level_graph = *lgraph_p;
2327   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2328 
2329   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
2330   ilu_permuted(level_graph);
2331 
2332   /* put together the new matrix */
2333   ierr = MatCreate(PetscObjectComm((PetscObject)A), fact);CHKERRQ(ierr);
2334   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
2335   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
2336   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
2337   ierr = MatSetBlockSizesFromMats(fact,A,A);CHKERRQ(ierr);
2338   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
2339   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2340   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2341 
2342   ierr = PetscContainerCreate(PetscObjectComm((PetscObject)A), &c);
2343   ierr = PetscContainerSetPointer(c, lgraph_p);
2344   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
2345   ierr = PetscContainerDestroy(&c);
2346   PetscFunctionReturn(0);
2347 }
2348 
2349 #undef __FUNCT__
2350 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
2351 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
2352 {
2353   PetscFunctionBegin;
2354   PetscFunctionReturn(0);
2355 }
2356 
2357 #undef __FUNCT__
2358 #define __FUNCT__ "MatSolve_MPIAIJ"
2359 /*
2360   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2361 */
2362 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
2363 {
2364   namespace graph_dist = boost::graph::distributed;
2365 
2366   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2367   lgraph_type    *lgraph_p;
2368   PetscContainer c;
2369   PetscErrorCode ierr;
2370 
2371   PetscFunctionBegin;
2372   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject*) &c);CHKERRQ(ierr);
2373   ierr = PetscContainerGetPointer(c, (void**) &lgraph_p);CHKERRQ(ierr);
2374   ierr = VecCopy(b, x);CHKERRQ(ierr);
2375 
2376   PetscScalar *array_x;
2377   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
2378   PetscInt sx;
2379   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
2380 
2381   PetscScalar *array_b;
2382   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
2383   PetscInt sb;
2384   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
2385 
2386   lgraph_type& level_graph = *lgraph_p;
2387   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2388 
2389   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
2390   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]);
2391   array_ref_type                                 ref_x(array_x, boost::extents[num_vertices(graph)]);
2392 
2393   typedef boost::iterator_property_map<array_ref_type::iterator,
2394                                        boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
2395   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph));
2396   gvector_type                                   vector_x(ref_x.begin(), get(boost::vertex_index, graph));
2397 
2398   ilu_set_solve(*lgraph_p, vector_b, vector_x);
2399   PetscFunctionReturn(0);
2400 }
2401 #endif
2402 
2403 
2404 #undef __FUNCT__
2405 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ_interlaced"
2406 PetscErrorCode MatGetRedundantMatrix_MPIAIJ_interlaced(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,MatReuse reuse,Mat *matredundant)
2407 {
2408   PetscMPIInt    rank,size;
2409   MPI_Comm       comm;
2410   PetscErrorCode ierr;
2411   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0,M=mat->rmap->N,N=mat->cmap->N;
2412   PetscMPIInt    *send_rank= NULL,*recv_rank=NULL,subrank,subsize;
2413   PetscInt       *rowrange = mat->rmap->range;
2414   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2415   Mat            A = aij->A,B=aij->B,C=*matredundant;
2416   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2417   PetscScalar    *sbuf_a;
2418   PetscInt       nzlocal=a->nz+b->nz;
2419   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2420   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray;
2421   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2422   MatScalar      *aworkA,*aworkB;
2423   PetscScalar    *vals;
2424   PetscMPIInt    tag1,tag2,tag3,imdex;
2425   MPI_Request    *s_waits1=NULL,*s_waits2=NULL,*s_waits3=NULL;
2426   MPI_Request    *r_waits1=NULL,*r_waits2=NULL,*r_waits3=NULL;
2427   MPI_Status     recv_status,*send_status;
2428   PetscInt       *sbuf_nz=NULL,*rbuf_nz=NULL,count;
2429   PetscInt       **rbuf_j=NULL;
2430   PetscScalar    **rbuf_a=NULL;
2431   Mat_Redundant  *redund =NULL;
2432 
2433   PetscFunctionBegin;
2434   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2435   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2436   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2437   ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2438   ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2439 
2440   if (reuse == MAT_REUSE_MATRIX) {
2441     if (M != mat->rmap->N || N != mat->cmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2442 
2443     redund = C->redundant;
2444     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2445 
2446     nsends    = redund->nsends;
2447     nrecvs    = redund->nrecvs;
2448     send_rank = redund->send_rank;
2449     recv_rank = redund->recv_rank;
2450     sbuf_nz   = redund->sbuf_nz;
2451     rbuf_nz   = redund->rbuf_nz;
2452     sbuf_j    = redund->sbuf_j;
2453     sbuf_a    = redund->sbuf_a;
2454     rbuf_j    = redund->rbuf_j;
2455     rbuf_a    = redund->rbuf_a;
2456   }
2457 
2458   if (reuse == MAT_INITIAL_MATRIX) {
2459     PetscInt    nleftover,np_subcomm;
2460 
2461     /* get the destination processors' id send_rank, nsends and nrecvs */
2462     ierr = PetscMalloc2(size,&send_rank,size,&recv_rank);CHKERRQ(ierr);
2463 
2464     np_subcomm = size/nsubcomm;
2465     nleftover  = size - nsubcomm*np_subcomm;
2466 
2467     /* block of codes below is specific for INTERLACED */
2468     /* ------------------------------------------------*/
2469     nsends = 0; nrecvs = 0;
2470     for (i=0; i<size; i++) {
2471       if (subrank == i/nsubcomm && i != rank) { /* my_subrank == other's subrank */
2472         send_rank[nsends++] = i;
2473         recv_rank[nrecvs++] = i;
2474       }
2475     }
2476     if (rank >= size - nleftover) { /* this proc is a leftover processor */
2477       i = size-nleftover-1;
2478       j = 0;
2479       while (j < nsubcomm - nleftover) {
2480         send_rank[nsends++] = i;
2481         i--; j++;
2482       }
2483     }
2484 
2485     if (nleftover && subsize == size/nsubcomm && subrank==subsize-1) { /* this proc recvs from leftover processors */
2486       for (i=0; i<nleftover; i++) {
2487         recv_rank[nrecvs++] = size-nleftover+i;
2488       }
2489     }
2490     /*----------------------------------------------*/
2491 
2492     /* allocate sbuf_j, sbuf_a */
2493     i    = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2494     ierr = PetscMalloc1(i,&sbuf_j);CHKERRQ(ierr);
2495     ierr = PetscMalloc1((nzlocal+1),&sbuf_a);CHKERRQ(ierr);
2496     /*
2497     ierr = PetscSynchronizedPrintf(comm,"[%d] nsends %d, nrecvs %d\n",rank,nsends,nrecvs);CHKERRQ(ierr);
2498     ierr = PetscSynchronizedFlush(comm,PETSC_STDOUT);CHKERRQ(ierr);
2499      */
2500   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2501 
2502   /* copy mat's local entries into the buffers */
2503   if (reuse == MAT_INITIAL_MATRIX) {
2504     rownz_max = 0;
2505     rptr      = sbuf_j;
2506     cols      = sbuf_j + rend-rstart + 1;
2507     vals      = sbuf_a;
2508     rptr[0]   = 0;
2509     for (i=0; i<rend-rstart; i++) {
2510       row    = i + rstart;
2511       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2512       ncols  = nzA + nzB;
2513       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2514       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2515       /* load the column indices for this row into cols */
2516       lwrite = 0;
2517       for (l=0; l<nzB; l++) {
2518         if ((ctmp = bmap[cworkB[l]]) < cstart) {
2519           vals[lwrite]   = aworkB[l];
2520           cols[lwrite++] = ctmp;
2521         }
2522       }
2523       for (l=0; l<nzA; l++) {
2524         vals[lwrite]   = aworkA[l];
2525         cols[lwrite++] = cstart + cworkA[l];
2526       }
2527       for (l=0; l<nzB; l++) {
2528         if ((ctmp = bmap[cworkB[l]]) >= cend) {
2529           vals[lwrite]   = aworkB[l];
2530           cols[lwrite++] = ctmp;
2531         }
2532       }
2533       vals     += ncols;
2534       cols     += ncols;
2535       rptr[i+1] = rptr[i] + ncols;
2536       if (rownz_max < ncols) rownz_max = ncols;
2537     }
2538     if (rptr[rend-rstart] != a->nz + b->nz) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB, "rptr[%d] %d != %d + %d",rend-rstart,rptr[rend-rstart+1],a->nz,b->nz);
2539   } else { /* only copy matrix values into sbuf_a */
2540     rptr    = sbuf_j;
2541     vals    = sbuf_a;
2542     rptr[0] = 0;
2543     for (i=0; i<rend-rstart; i++) {
2544       row    = i + rstart;
2545       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2546       ncols  = nzA + nzB;
2547       cworkB = b->j + b->i[i];
2548       aworkA = a->a + a->i[i];
2549       aworkB = b->a + b->i[i];
2550       lwrite = 0;
2551       for (l=0; l<nzB; l++) {
2552         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2553       }
2554       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2555       for (l=0; l<nzB; l++) {
2556         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2557       }
2558       vals     += ncols;
2559       rptr[i+1] = rptr[i] + ncols;
2560     }
2561   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2562 
2563   /* send nzlocal to others, and recv other's nzlocal */
2564   /*--------------------------------------------------*/
2565   if (reuse == MAT_INITIAL_MATRIX) {
2566     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,&s_waits3,nsends+1,&send_status);CHKERRQ(ierr);
2567 
2568     s_waits2 = s_waits3 + nsends;
2569     s_waits1 = s_waits2 + nsends;
2570     r_waits1 = s_waits1 + nsends;
2571     r_waits2 = r_waits1 + nrecvs;
2572     r_waits3 = r_waits2 + nrecvs;
2573   } else {
2574     ierr = PetscMalloc2(nsends + nrecvs +1,&s_waits3,nsends+1,&send_status);CHKERRQ(ierr);
2575 
2576     r_waits3 = s_waits3 + nsends;
2577   }
2578 
2579   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2580   if (reuse == MAT_INITIAL_MATRIX) {
2581     /* get new tags to keep the communication clean */
2582     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2583     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2584     ierr = PetscMalloc4(nsends,&sbuf_nz,nrecvs,&rbuf_nz,nrecvs,&rbuf_j,nrecvs,&rbuf_a);CHKERRQ(ierr);
2585 
2586     /* post receives of other's nzlocal */
2587     for (i=0; i<nrecvs; i++) {
2588       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2589     }
2590     /* send nzlocal to others */
2591     for (i=0; i<nsends; i++) {
2592       sbuf_nz[i] = nzlocal;
2593       ierr       = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2594     }
2595     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2596     count = nrecvs;
2597     while (count) {
2598       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2599 
2600       recv_rank[imdex] = recv_status.MPI_SOURCE;
2601       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2602       ierr = PetscMalloc1((rbuf_nz[imdex]+1),&rbuf_a[imdex]);CHKERRQ(ierr);
2603 
2604       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2605 
2606       rbuf_nz[imdex] += i + 2;
2607 
2608       ierr = PetscMalloc1(rbuf_nz[imdex],&rbuf_j[imdex]);CHKERRQ(ierr);
2609       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2610       count--;
2611     }
2612     /* wait on sends of nzlocal */
2613     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2614     /* send mat->i,j to others, and recv from other's */
2615     /*------------------------------------------------*/
2616     for (i=0; i<nsends; i++) {
2617       j    = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2618       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2619     }
2620     /* wait on receives of mat->i,j */
2621     /*------------------------------*/
2622     count = nrecvs;
2623     while (count) {
2624       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2625       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2626       count--;
2627     }
2628     /* wait on sends of mat->i,j */
2629     /*---------------------------*/
2630     if (nsends) {
2631       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2632     }
2633   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2634 
2635   /* post receives, send and receive mat->a */
2636   /*----------------------------------------*/
2637   for (imdex=0; imdex<nrecvs; imdex++) {
2638     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2639   }
2640   for (i=0; i<nsends; i++) {
2641     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2642   }
2643   count = nrecvs;
2644   while (count) {
2645     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2646     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2647     count--;
2648   }
2649   if (nsends) {
2650     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2651   }
2652 
2653   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2654 
2655   /* create redundant matrix */
2656   /*-------------------------*/
2657   if (reuse == MAT_INITIAL_MATRIX) {
2658     const PetscInt *range;
2659     PetscInt       rstart_sub,rend_sub,mloc_sub;
2660 
2661     /* compute rownz_max for preallocation */
2662     for (imdex=0; imdex<nrecvs; imdex++) {
2663       j    = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2664       rptr = rbuf_j[imdex];
2665       for (i=0; i<j; i++) {
2666         ncols = rptr[i+1] - rptr[i];
2667         if (rownz_max < ncols) rownz_max = ncols;
2668       }
2669     }
2670 
2671     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2672 
2673     /* get local size of redundant matrix
2674        - mloc_sub is chosen for PETSC_SUBCOMM_INTERLACED, works for other types, but may not efficient! */
2675     ierr = MatGetOwnershipRanges(mat,&range);CHKERRQ(ierr);
2676     rstart_sub = range[nsubcomm*subrank];
2677     if (subrank+1 < subsize) { /* not the last proc in subcomm */
2678       rend_sub = range[nsubcomm*(subrank+1)];
2679     } else {
2680       rend_sub = mat->rmap->N;
2681     }
2682     mloc_sub = rend_sub - rstart_sub;
2683 
2684     if (M == N) {
2685       ierr = MatSetSizes(C,mloc_sub,mloc_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2686     } else { /* non-square matrix */
2687       ierr = MatSetSizes(C,mloc_sub,PETSC_DECIDE,PETSC_DECIDE,mat->cmap->N);CHKERRQ(ierr);
2688     }
2689     ierr = MatSetBlockSizesFromMats(C,mat,mat);CHKERRQ(ierr);
2690     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2691     ierr = MatSeqAIJSetPreallocation(C,rownz_max,NULL);CHKERRQ(ierr);
2692     ierr = MatMPIAIJSetPreallocation(C,rownz_max,NULL,rownz_max,NULL);CHKERRQ(ierr);
2693   } else {
2694     C = *matredundant;
2695   }
2696 
2697   /* insert local matrix entries */
2698   rptr = sbuf_j;
2699   cols = sbuf_j + rend-rstart + 1;
2700   vals = sbuf_a;
2701   for (i=0; i<rend-rstart; i++) {
2702     row   = i + rstart;
2703     ncols = rptr[i+1] - rptr[i];
2704     ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2705     vals += ncols;
2706     cols += ncols;
2707   }
2708   /* insert received matrix entries */
2709   for (imdex=0; imdex<nrecvs; imdex++) {
2710     rstart = rowrange[recv_rank[imdex]];
2711     rend   = rowrange[recv_rank[imdex]+1];
2712     /* printf("[%d] insert rows %d - %d\n",rank,rstart,rend-1); */
2713     rptr   = rbuf_j[imdex];
2714     cols   = rbuf_j[imdex] + rend-rstart + 1;
2715     vals   = rbuf_a[imdex];
2716     for (i=0; i<rend-rstart; i++) {
2717       row   = i + rstart;
2718       ncols = rptr[i+1] - rptr[i];
2719       ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2720       vals += ncols;
2721       cols += ncols;
2722     }
2723   }
2724   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2725   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2726 
2727   if (reuse == MAT_INITIAL_MATRIX) {
2728     *matredundant = C;
2729 
2730     /* create a supporting struct and attach it to C for reuse */
2731     ierr = PetscNewLog(C,&redund);CHKERRQ(ierr);
2732     C->redundant      = redund;
2733     redund->nzlocal   = nzlocal;
2734     redund->nsends    = nsends;
2735     redund->nrecvs    = nrecvs;
2736     redund->send_rank = send_rank;
2737     redund->recv_rank = recv_rank;
2738     redund->sbuf_nz   = sbuf_nz;
2739     redund->rbuf_nz   = rbuf_nz;
2740     redund->sbuf_j    = sbuf_j;
2741     redund->sbuf_a    = sbuf_a;
2742     redund->rbuf_j    = rbuf_j;
2743     redund->rbuf_a    = rbuf_a;
2744     redund->subcomm   = subcomm;
2745     redund->type      = PETSC_SUBCOMM_INTERLACED;
2746   }
2747   PetscFunctionReturn(0);
2748 }
2749 
2750 #undef __FUNCT__
2751 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2752 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,MatReuse reuse,Mat *matredundant)
2753 {
2754   PetscErrorCode ierr;
2755   MPI_Comm       comm;
2756   PetscMPIInt    size;
2757   PetscInt       mloc_sub,rstart,rend,M=mat->rmap->N,N=mat->cmap->N;
2758   Mat_Redundant  *redund=NULL;
2759   PetscSubcomm   psubcomm=NULL;
2760   MPI_Comm       subcomm_in=subcomm;
2761   Mat            *matseq;
2762   IS             isrow,iscol;
2763 
2764   PetscFunctionBegin;
2765   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
2766     /* create psubcomm, then get subcomm */
2767     ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2768     ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2769     if (nsubcomm < 1 || nsubcomm > size) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"nsubcomm must between 1 and %D",size);
2770 
2771     ierr = PetscSubcommCreate(comm,&psubcomm);CHKERRQ(ierr);
2772     ierr = PetscSubcommSetNumber(psubcomm,nsubcomm);CHKERRQ(ierr);
2773     ierr = PetscSubcommSetType(psubcomm,PETSC_SUBCOMM_CONTIGUOUS);CHKERRQ(ierr);
2774     ierr = PetscSubcommSetFromOptions(psubcomm);CHKERRQ(ierr);
2775     ierr = PetscCommDuplicate(psubcomm->comm,&subcomm,NULL);CHKERRQ(ierr);
2776     if (psubcomm->type == PETSC_SUBCOMM_INTERLACED) {
2777       ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2778       ierr = PetscSubcommDestroy(&psubcomm);CHKERRQ(ierr);
2779       PetscFunctionReturn(0);
2780     }
2781     ierr = PetscSubcommDestroy(&psubcomm);CHKERRQ(ierr);
2782   }
2783 
2784   /* get isrow and iscol for redund->type == PETSC_SUBCOMM_CONTIGUOUS */
2785   if (reuse == MAT_INITIAL_MATRIX) {
2786     /* create a local sequential matrix matseq[0] */
2787     mloc_sub = PETSC_DECIDE;
2788     ierr = PetscSplitOwnership(subcomm,&mloc_sub,&M);CHKERRQ(ierr);
2789     ierr = MPI_Scan(&mloc_sub,&rend,1,MPIU_INT,MPI_SUM,subcomm);CHKERRQ(ierr);
2790     rstart = rend - mloc_sub;
2791     ierr = ISCreateStride(PETSC_COMM_SELF,mloc_sub,rstart,1,&isrow);CHKERRQ(ierr);
2792     ierr = ISCreateStride(PETSC_COMM_SELF,N,0,1,&iscol);CHKERRQ(ierr);
2793   } else { /* reuse == MAT_REUSE_MATRIX */
2794     /* retrieve subcomm */
2795     ierr = PetscObjectGetComm((PetscObject)(*matredundant),&subcomm);CHKERRQ(ierr);
2796     redund = (*matredundant)->redundant;
2797     if (redund->type == PETSC_SUBCOMM_INTERLACED) {
2798       ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2799       PetscFunctionReturn(0);
2800     }
2801 
2802     isrow  = redund->isrow;
2803     iscol  = redund->iscol;
2804     matseq = redund->matseq;
2805   }
2806   ierr = MatGetSubMatrices(mat,1,&isrow,&iscol,reuse,&matseq);CHKERRQ(ierr);
2807   ierr = MatCreateMPIMatConcatenateSeqMat(subcomm,matseq[0],PETSC_DECIDE,reuse,matredundant);CHKERRQ(ierr);
2808 
2809   if (reuse == MAT_INITIAL_MATRIX) {
2810     /* create a supporting struct and attach it to C for reuse */
2811     ierr = PetscNewLog(*matredundant,&redund);CHKERRQ(ierr);
2812     (*matredundant)->redundant = redund;
2813     redund->isrow              = isrow;
2814     redund->iscol              = iscol;
2815     redund->matseq             = matseq;
2816     redund->subcomm            = subcomm;
2817     redund->type               = PETSC_SUBCOMM_CONTIGUOUS;
2818   }
2819   PetscFunctionReturn(0);
2820 }
2821 
2822 #undef __FUNCT__
2823 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2824 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2825 {
2826   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2827   PetscErrorCode ierr;
2828   PetscInt       i,*idxb = 0;
2829   PetscScalar    *va,*vb;
2830   Vec            vtmp;
2831 
2832   PetscFunctionBegin;
2833   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2834   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2835   if (idx) {
2836     for (i=0; i<A->rmap->n; i++) {
2837       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2838     }
2839   }
2840 
2841   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2842   if (idx) {
2843     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2844   }
2845   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2846   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2847 
2848   for (i=0; i<A->rmap->n; i++) {
2849     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2850       va[i] = vb[i];
2851       if (idx) idx[i] = a->garray[idxb[i]];
2852     }
2853   }
2854 
2855   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2856   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2857   ierr = PetscFree(idxb);CHKERRQ(ierr);
2858   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2859   PetscFunctionReturn(0);
2860 }
2861 
2862 #undef __FUNCT__
2863 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2864 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2865 {
2866   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2867   PetscErrorCode ierr;
2868   PetscInt       i,*idxb = 0;
2869   PetscScalar    *va,*vb;
2870   Vec            vtmp;
2871 
2872   PetscFunctionBegin;
2873   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2874   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2875   if (idx) {
2876     for (i=0; i<A->cmap->n; i++) {
2877       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2878     }
2879   }
2880 
2881   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2882   if (idx) {
2883     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2884   }
2885   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2886   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2887 
2888   for (i=0; i<A->rmap->n; i++) {
2889     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2890       va[i] = vb[i];
2891       if (idx) idx[i] = a->garray[idxb[i]];
2892     }
2893   }
2894 
2895   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2896   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2897   ierr = PetscFree(idxb);CHKERRQ(ierr);
2898   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2899   PetscFunctionReturn(0);
2900 }
2901 
2902 #undef __FUNCT__
2903 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2904 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2905 {
2906   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2907   PetscInt       n      = A->rmap->n;
2908   PetscInt       cstart = A->cmap->rstart;
2909   PetscInt       *cmap  = mat->garray;
2910   PetscInt       *diagIdx, *offdiagIdx;
2911   Vec            diagV, offdiagV;
2912   PetscScalar    *a, *diagA, *offdiagA;
2913   PetscInt       r;
2914   PetscErrorCode ierr;
2915 
2916   PetscFunctionBegin;
2917   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2918   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
2919   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
2920   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2921   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2922   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2923   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2924   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2925   for (r = 0; r < n; ++r) {
2926     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2927       a[r]   = diagA[r];
2928       idx[r] = cstart + diagIdx[r];
2929     } else {
2930       a[r]   = offdiagA[r];
2931       idx[r] = cmap[offdiagIdx[r]];
2932     }
2933   }
2934   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2935   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2936   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2937   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2938   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2939   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2940   PetscFunctionReturn(0);
2941 }
2942 
2943 #undef __FUNCT__
2944 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2945 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2946 {
2947   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2948   PetscInt       n      = A->rmap->n;
2949   PetscInt       cstart = A->cmap->rstart;
2950   PetscInt       *cmap  = mat->garray;
2951   PetscInt       *diagIdx, *offdiagIdx;
2952   Vec            diagV, offdiagV;
2953   PetscScalar    *a, *diagA, *offdiagA;
2954   PetscInt       r;
2955   PetscErrorCode ierr;
2956 
2957   PetscFunctionBegin;
2958   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2959   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
2960   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
2961   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2962   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2963   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2964   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2965   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2966   for (r = 0; r < n; ++r) {
2967     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2968       a[r]   = diagA[r];
2969       idx[r] = cstart + diagIdx[r];
2970     } else {
2971       a[r]   = offdiagA[r];
2972       idx[r] = cmap[offdiagIdx[r]];
2973     }
2974   }
2975   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2976   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2977   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2978   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2979   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2980   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2981   PetscFunctionReturn(0);
2982 }
2983 
2984 #undef __FUNCT__
2985 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
2986 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2987 {
2988   PetscErrorCode ierr;
2989   Mat            *dummy;
2990 
2991   PetscFunctionBegin;
2992   ierr    = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2993   *newmat = *dummy;
2994   ierr    = PetscFree(dummy);CHKERRQ(ierr);
2995   PetscFunctionReturn(0);
2996 }
2997 
2998 #undef __FUNCT__
2999 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
3000 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
3001 {
3002   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
3003   PetscErrorCode ierr;
3004 
3005   PetscFunctionBegin;
3006   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
3007   PetscFunctionReturn(0);
3008 }
3009 
3010 #undef __FUNCT__
3011 #define __FUNCT__ "MatSetRandom_MPIAIJ"
3012 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
3013 {
3014   PetscErrorCode ierr;
3015   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
3016 
3017   PetscFunctionBegin;
3018   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
3019   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
3020   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3021   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3022   PetscFunctionReturn(0);
3023 }
3024 
3025 /* -------------------------------------------------------------------*/
3026 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
3027                                        MatGetRow_MPIAIJ,
3028                                        MatRestoreRow_MPIAIJ,
3029                                        MatMult_MPIAIJ,
3030                                 /* 4*/ MatMultAdd_MPIAIJ,
3031                                        MatMultTranspose_MPIAIJ,
3032                                        MatMultTransposeAdd_MPIAIJ,
3033 #if defined(PETSC_HAVE_PBGL)
3034                                        MatSolve_MPIAIJ,
3035 #else
3036                                        0,
3037 #endif
3038                                        0,
3039                                        0,
3040                                 /*10*/ 0,
3041                                        0,
3042                                        0,
3043                                        MatSOR_MPIAIJ,
3044                                        MatTranspose_MPIAIJ,
3045                                 /*15*/ MatGetInfo_MPIAIJ,
3046                                        MatEqual_MPIAIJ,
3047                                        MatGetDiagonal_MPIAIJ,
3048                                        MatDiagonalScale_MPIAIJ,
3049                                        MatNorm_MPIAIJ,
3050                                 /*20*/ MatAssemblyBegin_MPIAIJ,
3051                                        MatAssemblyEnd_MPIAIJ,
3052                                        MatSetOption_MPIAIJ,
3053                                        MatZeroEntries_MPIAIJ,
3054                                 /*24*/ MatZeroRows_MPIAIJ,
3055                                        0,
3056 #if defined(PETSC_HAVE_PBGL)
3057                                        0,
3058 #else
3059                                        0,
3060 #endif
3061                                        0,
3062                                        0,
3063                                 /*29*/ MatSetUp_MPIAIJ,
3064 #if defined(PETSC_HAVE_PBGL)
3065                                        0,
3066 #else
3067                                        0,
3068 #endif
3069                                        0,
3070                                        0,
3071                                        0,
3072                                 /*34*/ MatDuplicate_MPIAIJ,
3073                                        0,
3074                                        0,
3075                                        0,
3076                                        0,
3077                                 /*39*/ MatAXPY_MPIAIJ,
3078                                        MatGetSubMatrices_MPIAIJ,
3079                                        MatIncreaseOverlap_MPIAIJ,
3080                                        MatGetValues_MPIAIJ,
3081                                        MatCopy_MPIAIJ,
3082                                 /*44*/ MatGetRowMax_MPIAIJ,
3083                                        MatScale_MPIAIJ,
3084                                        0,
3085                                        MatDiagonalSet_MPIAIJ,
3086                                        MatZeroRowsColumns_MPIAIJ,
3087                                 /*49*/ MatSetRandom_MPIAIJ,
3088                                        0,
3089                                        0,
3090                                        0,
3091                                        0,
3092                                 /*54*/ MatFDColoringCreate_MPIXAIJ,
3093                                        0,
3094                                        MatSetUnfactored_MPIAIJ,
3095                                        MatPermute_MPIAIJ,
3096                                        0,
3097                                 /*59*/ MatGetSubMatrix_MPIAIJ,
3098                                        MatDestroy_MPIAIJ,
3099                                        MatView_MPIAIJ,
3100                                        0,
3101                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
3102                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
3103                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
3104                                        0,
3105                                        0,
3106                                        0,
3107                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
3108                                        MatGetRowMinAbs_MPIAIJ,
3109                                        0,
3110                                        MatSetColoring_MPIAIJ,
3111                                        0,
3112                                        MatSetValuesAdifor_MPIAIJ,
3113                                 /*75*/ MatFDColoringApply_AIJ,
3114                                        0,
3115                                        0,
3116                                        0,
3117                                        MatFindZeroDiagonals_MPIAIJ,
3118                                 /*80*/ 0,
3119                                        0,
3120                                        0,
3121                                 /*83*/ MatLoad_MPIAIJ,
3122                                        0,
3123                                        0,
3124                                        0,
3125                                        0,
3126                                        0,
3127                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
3128                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
3129                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
3130                                        MatPtAP_MPIAIJ_MPIAIJ,
3131                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
3132                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
3133                                        0,
3134                                        0,
3135                                        0,
3136                                        0,
3137                                 /*99*/ 0,
3138                                        0,
3139                                        0,
3140                                        MatConjugate_MPIAIJ,
3141                                        0,
3142                                 /*104*/MatSetValuesRow_MPIAIJ,
3143                                        MatRealPart_MPIAIJ,
3144                                        MatImaginaryPart_MPIAIJ,
3145                                        0,
3146                                        0,
3147                                 /*109*/0,
3148                                        MatGetRedundantMatrix_MPIAIJ,
3149                                        MatGetRowMin_MPIAIJ,
3150                                        0,
3151                                        0,
3152                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
3153                                        0,
3154                                        0,
3155                                        0,
3156                                        0,
3157                                 /*119*/0,
3158                                        0,
3159                                        0,
3160                                        0,
3161                                        MatGetMultiProcBlock_MPIAIJ,
3162                                 /*124*/MatFindNonzeroRows_MPIAIJ,
3163                                        MatGetColumnNorms_MPIAIJ,
3164                                        MatInvertBlockDiagonal_MPIAIJ,
3165                                        0,
3166                                        MatGetSubMatricesParallel_MPIAIJ,
3167                                 /*129*/0,
3168                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
3169                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
3170                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
3171                                        0,
3172                                 /*134*/0,
3173                                        0,
3174                                        0,
3175                                        0,
3176                                        0,
3177                                 /*139*/0,
3178                                        0,
3179                                        0,
3180                                        MatFDColoringSetUp_MPIXAIJ,
3181                                        0,
3182                                 /*144*/MatCreateMPIMatConcatenateSeqMat_MPIAIJ
3183 };
3184 
3185 /* ----------------------------------------------------------------------------------------*/
3186 
3187 #undef __FUNCT__
3188 #define __FUNCT__ "MatStoreValues_MPIAIJ"
3189 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
3190 {
3191   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3192   PetscErrorCode ierr;
3193 
3194   PetscFunctionBegin;
3195   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
3196   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
3197   PetscFunctionReturn(0);
3198 }
3199 
3200 #undef __FUNCT__
3201 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
3202 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
3203 {
3204   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3205   PetscErrorCode ierr;
3206 
3207   PetscFunctionBegin;
3208   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
3209   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
3210   PetscFunctionReturn(0);
3211 }
3212 
3213 #undef __FUNCT__
3214 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
3215 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3216 {
3217   Mat_MPIAIJ     *b;
3218   PetscErrorCode ierr;
3219 
3220   PetscFunctionBegin;
3221   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3222   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3223   b = (Mat_MPIAIJ*)B->data;
3224 
3225   if (!B->preallocated) {
3226     /* Explicitly create 2 MATSEQAIJ matrices. */
3227     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
3228     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
3229     ierr = MatSetBlockSizesFromMats(b->A,B,B);CHKERRQ(ierr);
3230     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
3231     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->A);CHKERRQ(ierr);
3232     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
3233     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
3234     ierr = MatSetBlockSizesFromMats(b->B,B,B);CHKERRQ(ierr);
3235     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
3236     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->B);CHKERRQ(ierr);
3237   }
3238 
3239   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
3240   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
3241   B->preallocated = PETSC_TRUE;
3242   PetscFunctionReturn(0);
3243 }
3244 
3245 #undef __FUNCT__
3246 #define __FUNCT__ "MatDuplicate_MPIAIJ"
3247 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
3248 {
3249   Mat            mat;
3250   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
3251   PetscErrorCode ierr;
3252 
3253   PetscFunctionBegin;
3254   *newmat = 0;
3255   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
3256   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
3257   ierr    = MatSetBlockSizesFromMats(mat,matin,matin);CHKERRQ(ierr);
3258   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
3259   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
3260   a       = (Mat_MPIAIJ*)mat->data;
3261 
3262   mat->factortype   = matin->factortype;
3263   mat->assembled    = PETSC_TRUE;
3264   mat->insertmode   = NOT_SET_VALUES;
3265   mat->preallocated = PETSC_TRUE;
3266 
3267   a->size         = oldmat->size;
3268   a->rank         = oldmat->rank;
3269   a->donotstash   = oldmat->donotstash;
3270   a->roworiented  = oldmat->roworiented;
3271   a->rowindices   = 0;
3272   a->rowvalues    = 0;
3273   a->getrowactive = PETSC_FALSE;
3274 
3275   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
3276   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
3277 
3278   if (oldmat->colmap) {
3279 #if defined(PETSC_USE_CTABLE)
3280     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
3281 #else
3282     ierr = PetscMalloc1((mat->cmap->N),&a->colmap);CHKERRQ(ierr);
3283     ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3284     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3285 #endif
3286   } else a->colmap = 0;
3287   if (oldmat->garray) {
3288     PetscInt len;
3289     len  = oldmat->B->cmap->n;
3290     ierr = PetscMalloc1((len+1),&a->garray);CHKERRQ(ierr);
3291     ierr = PetscLogObjectMemory((PetscObject)mat,len*sizeof(PetscInt));CHKERRQ(ierr);
3292     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
3293   } else a->garray = 0;
3294 
3295   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
3296   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->lvec);CHKERRQ(ierr);
3297   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
3298   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->Mvctx);CHKERRQ(ierr);
3299   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
3300   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->A);CHKERRQ(ierr);
3301   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
3302   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->B);CHKERRQ(ierr);
3303   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
3304   *newmat = mat;
3305   PetscFunctionReturn(0);
3306 }
3307 
3308 
3309 
3310 #undef __FUNCT__
3311 #define __FUNCT__ "MatLoad_MPIAIJ"
3312 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3313 {
3314   PetscScalar    *vals,*svals;
3315   MPI_Comm       comm;
3316   PetscErrorCode ierr;
3317   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
3318   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0,grows,gcols;
3319   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
3320   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
3321   PetscInt       cend,cstart,n,*rowners,sizesset=1;
3322   int            fd;
3323   PetscInt       bs = 1;
3324 
3325   PetscFunctionBegin;
3326   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
3327   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3328   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3329   if (!rank) {
3330     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
3331     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
3332     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
3333   }
3334 
3335   ierr = PetscOptionsBegin(comm,NULL,"Options for loading SEQAIJ matrix","Mat");CHKERRQ(ierr);
3336   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
3337   ierr = PetscOptionsEnd();CHKERRQ(ierr);
3338 
3339   if (newMat->rmap->n < 0 && newMat->rmap->N < 0 && newMat->cmap->n < 0 && newMat->cmap->N < 0) sizesset = 0;
3340 
3341   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
3342   M    = header[1]; N = header[2];
3343   /* If global rows/cols are set to PETSC_DECIDE, set it to the sizes given in the file */
3344   if (sizesset && newMat->rmap->N < 0) newMat->rmap->N = M;
3345   if (sizesset && newMat->cmap->N < 0) newMat->cmap->N = N;
3346 
3347   /* If global sizes are set, check if they are consistent with that given in the file */
3348   if (sizesset) {
3349     ierr = MatGetSize(newMat,&grows,&gcols);CHKERRQ(ierr);
3350   }
3351   if (sizesset && newMat->rmap->N != grows) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows:Matrix in file has (%d) and input matrix has (%d)",M,grows);
3352   if (sizesset && newMat->cmap->N != gcols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of cols:Matrix in file has (%d) and input matrix has (%d)",N,gcols);
3353 
3354   /* determine ownership of all (block) rows */
3355   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
3356   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
3357   else m = newMat->rmap->n; /* Set by user */
3358 
3359   ierr = PetscMalloc1((size+1),&rowners);CHKERRQ(ierr);
3360   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
3361 
3362   /* First process needs enough room for process with most rows */
3363   if (!rank) {
3364     mmax = rowners[1];
3365     for (i=2; i<=size; i++) {
3366       mmax = PetscMax(mmax, rowners[i]);
3367     }
3368   } else mmax = -1;             /* unused, but compilers complain */
3369 
3370   rowners[0] = 0;
3371   for (i=2; i<=size; i++) {
3372     rowners[i] += rowners[i-1];
3373   }
3374   rstart = rowners[rank];
3375   rend   = rowners[rank+1];
3376 
3377   /* distribute row lengths to all processors */
3378   ierr = PetscMalloc2(m,&ourlens,m,&offlens);CHKERRQ(ierr);
3379   if (!rank) {
3380     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
3381     ierr = PetscMalloc1(mmax,&rowlengths);CHKERRQ(ierr);
3382     ierr = PetscCalloc1(size,&procsnz);CHKERRQ(ierr);
3383     for (j=0; j<m; j++) {
3384       procsnz[0] += ourlens[j];
3385     }
3386     for (i=1; i<size; i++) {
3387       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
3388       /* calculate the number of nonzeros on each processor */
3389       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
3390         procsnz[i] += rowlengths[j];
3391       }
3392       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3393     }
3394     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
3395   } else {
3396     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3397   }
3398 
3399   if (!rank) {
3400     /* determine max buffer needed and allocate it */
3401     maxnz = 0;
3402     for (i=0; i<size; i++) {
3403       maxnz = PetscMax(maxnz,procsnz[i]);
3404     }
3405     ierr = PetscMalloc1(maxnz,&cols);CHKERRQ(ierr);
3406 
3407     /* read in my part of the matrix column indices  */
3408     nz   = procsnz[0];
3409     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3410     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
3411 
3412     /* read in every one elses and ship off */
3413     for (i=1; i<size; i++) {
3414       nz   = procsnz[i];
3415       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
3416       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3417     }
3418     ierr = PetscFree(cols);CHKERRQ(ierr);
3419   } else {
3420     /* determine buffer space needed for message */
3421     nz = 0;
3422     for (i=0; i<m; i++) {
3423       nz += ourlens[i];
3424     }
3425     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3426 
3427     /* receive message of column indices*/
3428     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3429   }
3430 
3431   /* determine column ownership if matrix is not square */
3432   if (N != M) {
3433     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
3434     else n = newMat->cmap->n;
3435     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3436     cstart = cend - n;
3437   } else {
3438     cstart = rstart;
3439     cend   = rend;
3440     n      = cend - cstart;
3441   }
3442 
3443   /* loop over local rows, determining number of off diagonal entries */
3444   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
3445   jj   = 0;
3446   for (i=0; i<m; i++) {
3447     for (j=0; j<ourlens[i]; j++) {
3448       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
3449       jj++;
3450     }
3451   }
3452 
3453   for (i=0; i<m; i++) {
3454     ourlens[i] -= offlens[i];
3455   }
3456   if (!sizesset) {
3457     ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
3458   }
3459 
3460   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
3461 
3462   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
3463 
3464   for (i=0; i<m; i++) {
3465     ourlens[i] += offlens[i];
3466   }
3467 
3468   if (!rank) {
3469     ierr = PetscMalloc1((maxnz+1),&vals);CHKERRQ(ierr);
3470 
3471     /* read in my part of the matrix numerical values  */
3472     nz   = procsnz[0];
3473     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3474 
3475     /* insert into matrix */
3476     jj      = rstart;
3477     smycols = mycols;
3478     svals   = vals;
3479     for (i=0; i<m; i++) {
3480       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3481       smycols += ourlens[i];
3482       svals   += ourlens[i];
3483       jj++;
3484     }
3485 
3486     /* read in other processors and ship out */
3487     for (i=1; i<size; i++) {
3488       nz   = procsnz[i];
3489       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3490       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3491     }
3492     ierr = PetscFree(procsnz);CHKERRQ(ierr);
3493   } else {
3494     /* receive numeric values */
3495     ierr = PetscMalloc1((nz+1),&vals);CHKERRQ(ierr);
3496 
3497     /* receive message of values*/
3498     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3499 
3500     /* insert into matrix */
3501     jj      = rstart;
3502     smycols = mycols;
3503     svals   = vals;
3504     for (i=0; i<m; i++) {
3505       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3506       smycols += ourlens[i];
3507       svals   += ourlens[i];
3508       jj++;
3509     }
3510   }
3511   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
3512   ierr = PetscFree(vals);CHKERRQ(ierr);
3513   ierr = PetscFree(mycols);CHKERRQ(ierr);
3514   ierr = PetscFree(rowners);CHKERRQ(ierr);
3515   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3516   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3517   PetscFunctionReturn(0);
3518 }
3519 
3520 #undef __FUNCT__
3521 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3522 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3523 {
3524   PetscErrorCode ierr;
3525   IS             iscol_local;
3526   PetscInt       csize;
3527 
3528   PetscFunctionBegin;
3529   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3530   if (call == MAT_REUSE_MATRIX) {
3531     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3532     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3533   } else {
3534     PetscInt cbs;
3535     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3536     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3537     ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
3538   }
3539   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3540   if (call == MAT_INITIAL_MATRIX) {
3541     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3542     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3543   }
3544   PetscFunctionReturn(0);
3545 }
3546 
3547 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3548 #undef __FUNCT__
3549 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3550 /*
3551     Not great since it makes two copies of the submatrix, first an SeqAIJ
3552   in local and then by concatenating the local matrices the end result.
3553   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3554 
3555   Note: This requires a sequential iscol with all indices.
3556 */
3557 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3558 {
3559   PetscErrorCode ierr;
3560   PetscMPIInt    rank,size;
3561   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3562   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3563   PetscBool      allcolumns, colflag;
3564   Mat            M,Mreuse;
3565   MatScalar      *vwork,*aa;
3566   MPI_Comm       comm;
3567   Mat_SeqAIJ     *aij;
3568 
3569   PetscFunctionBegin;
3570   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3571   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3572   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3573 
3574   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3575   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3576   if (colflag && ncol == mat->cmap->N) {
3577     allcolumns = PETSC_TRUE;
3578   } else {
3579     allcolumns = PETSC_FALSE;
3580   }
3581   if (call ==  MAT_REUSE_MATRIX) {
3582     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3583     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3584     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3585   } else {
3586     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3587   }
3588 
3589   /*
3590       m - number of local rows
3591       n - number of columns (same on all processors)
3592       rstart - first row in new global matrix generated
3593   */
3594   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3595   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3596   if (call == MAT_INITIAL_MATRIX) {
3597     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3598     ii  = aij->i;
3599     jj  = aij->j;
3600 
3601     /*
3602         Determine the number of non-zeros in the diagonal and off-diagonal
3603         portions of the matrix in order to do correct preallocation
3604     */
3605 
3606     /* first get start and end of "diagonal" columns */
3607     if (csize == PETSC_DECIDE) {
3608       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3609       if (mglobal == n) { /* square matrix */
3610         nlocal = m;
3611       } else {
3612         nlocal = n/size + ((n % size) > rank);
3613       }
3614     } else {
3615       nlocal = csize;
3616     }
3617     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3618     rstart = rend - nlocal;
3619     if (rank == size - 1 && rend != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,n);
3620 
3621     /* next, compute all the lengths */
3622     ierr  = PetscMalloc1((2*m+1),&dlens);CHKERRQ(ierr);
3623     olens = dlens + m;
3624     for (i=0; i<m; i++) {
3625       jend = ii[i+1] - ii[i];
3626       olen = 0;
3627       dlen = 0;
3628       for (j=0; j<jend; j++) {
3629         if (*jj < rstart || *jj >= rend) olen++;
3630         else dlen++;
3631         jj++;
3632       }
3633       olens[i] = olen;
3634       dlens[i] = dlen;
3635     }
3636     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3637     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3638     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3639     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3640     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3641     ierr = PetscFree(dlens);CHKERRQ(ierr);
3642   } else {
3643     PetscInt ml,nl;
3644 
3645     M    = *newmat;
3646     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3647     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3648     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3649     /*
3650          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3651        rather than the slower MatSetValues().
3652     */
3653     M->was_assembled = PETSC_TRUE;
3654     M->assembled     = PETSC_FALSE;
3655   }
3656   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3657   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3658   ii   = aij->i;
3659   jj   = aij->j;
3660   aa   = aij->a;
3661   for (i=0; i<m; i++) {
3662     row   = rstart + i;
3663     nz    = ii[i+1] - ii[i];
3664     cwork = jj;     jj += nz;
3665     vwork = aa;     aa += nz;
3666     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3667   }
3668 
3669   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3670   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3671   *newmat = M;
3672 
3673   /* save submatrix used in processor for next request */
3674   if (call ==  MAT_INITIAL_MATRIX) {
3675     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3676     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3677   }
3678   PetscFunctionReturn(0);
3679 }
3680 
3681 #undef __FUNCT__
3682 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3683 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3684 {
3685   PetscInt       m,cstart, cend,j,nnz,i,d;
3686   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3687   const PetscInt *JJ;
3688   PetscScalar    *values;
3689   PetscErrorCode ierr;
3690 
3691   PetscFunctionBegin;
3692   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3693 
3694   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3695   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3696   m      = B->rmap->n;
3697   cstart = B->cmap->rstart;
3698   cend   = B->cmap->rend;
3699   rstart = B->rmap->rstart;
3700 
3701   ierr = PetscMalloc2(m,&d_nnz,m,&o_nnz);CHKERRQ(ierr);
3702 
3703 #if defined(PETSC_USE_DEBUGGING)
3704   for (i=0; i<m; i++) {
3705     nnz = Ii[i+1]- Ii[i];
3706     JJ  = J + Ii[i];
3707     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3708     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3709     if (nnz && (JJ[nnz-1] >= B->cmap->N) SETERRRQ3(PETSC_ERR_ARG_WRONGSTATE,"Row %D ends with too large a column index %D (max allowed %D)",i,JJ[nnz-1],B->cmap->N);
3710   }
3711 #endif
3712 
3713   for (i=0; i<m; i++) {
3714     nnz     = Ii[i+1]- Ii[i];
3715     JJ      = J + Ii[i];
3716     nnz_max = PetscMax(nnz_max,nnz);
3717     d       = 0;
3718     for (j=0; j<nnz; j++) {
3719       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3720     }
3721     d_nnz[i] = d;
3722     o_nnz[i] = nnz - d;
3723   }
3724   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3725   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3726 
3727   if (v) values = (PetscScalar*)v;
3728   else {
3729     ierr = PetscCalloc1((nnz_max+1),&values);CHKERRQ(ierr);
3730   }
3731 
3732   for (i=0; i<m; i++) {
3733     ii   = i + rstart;
3734     nnz  = Ii[i+1]- Ii[i];
3735     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3736   }
3737   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3738   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3739 
3740   if (!v) {
3741     ierr = PetscFree(values);CHKERRQ(ierr);
3742   }
3743   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3744   PetscFunctionReturn(0);
3745 }
3746 
3747 #undef __FUNCT__
3748 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3749 /*@
3750    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3751    (the default parallel PETSc format).
3752 
3753    Collective on MPI_Comm
3754 
3755    Input Parameters:
3756 +  B - the matrix
3757 .  i - the indices into j for the start of each local row (starts with zero)
3758 .  j - the column indices for each local row (starts with zero)
3759 -  v - optional values in the matrix
3760 
3761    Level: developer
3762 
3763    Notes:
3764        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3765      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3766      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3767 
3768        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3769 
3770        The format which is used for the sparse matrix input, is equivalent to a
3771     row-major ordering.. i.e for the following matrix, the input data expected is
3772     as shown:
3773 
3774         1 0 0
3775         2 0 3     P0
3776        -------
3777         4 5 6     P1
3778 
3779      Process0 [P0]: rows_owned=[0,1]
3780         i =  {0,1,3}  [size = nrow+1  = 2+1]
3781         j =  {0,0,2}  [size = nz = 6]
3782         v =  {1,2,3}  [size = nz = 6]
3783 
3784      Process1 [P1]: rows_owned=[2]
3785         i =  {0,3}    [size = nrow+1  = 1+1]
3786         j =  {0,1,2}  [size = nz = 6]
3787         v =  {4,5,6}  [size = nz = 6]
3788 
3789 .keywords: matrix, aij, compressed row, sparse, parallel
3790 
3791 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
3792           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3793 @*/
3794 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3795 {
3796   PetscErrorCode ierr;
3797 
3798   PetscFunctionBegin;
3799   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3800   PetscFunctionReturn(0);
3801 }
3802 
3803 #undef __FUNCT__
3804 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3805 /*@C
3806    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3807    (the default parallel PETSc format).  For good matrix assembly performance
3808    the user should preallocate the matrix storage by setting the parameters
3809    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3810    performance can be increased by more than a factor of 50.
3811 
3812    Collective on MPI_Comm
3813 
3814    Input Parameters:
3815 +  B - the matrix
3816 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3817            (same value is used for all local rows)
3818 .  d_nnz - array containing the number of nonzeros in the various rows of the
3819            DIAGONAL portion of the local submatrix (possibly different for each row)
3820            or NULL, if d_nz is used to specify the nonzero structure.
3821            The size of this array is equal to the number of local rows, i.e 'm'.
3822            For matrices that will be factored, you must leave room for (and set)
3823            the diagonal entry even if it is zero.
3824 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3825            submatrix (same value is used for all local rows).
3826 -  o_nnz - array containing the number of nonzeros in the various rows of the
3827            OFF-DIAGONAL portion of the local submatrix (possibly different for
3828            each row) or NULL, if o_nz is used to specify the nonzero
3829            structure. The size of this array is equal to the number
3830            of local rows, i.e 'm'.
3831 
3832    If the *_nnz parameter is given then the *_nz parameter is ignored
3833 
3834    The AIJ format (also called the Yale sparse matrix format or
3835    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3836    storage.  The stored row and column indices begin with zero.
3837    See Users-Manual: ch_mat for details.
3838 
3839    The parallel matrix is partitioned such that the first m0 rows belong to
3840    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3841    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3842 
3843    The DIAGONAL portion of the local submatrix of a processor can be defined
3844    as the submatrix which is obtained by extraction the part corresponding to
3845    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3846    first row that belongs to the processor, r2 is the last row belonging to
3847    the this processor, and c1-c2 is range of indices of the local part of a
3848    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3849    common case of a square matrix, the row and column ranges are the same and
3850    the DIAGONAL part is also square. The remaining portion of the local
3851    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3852 
3853    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3854 
3855    You can call MatGetInfo() to get information on how effective the preallocation was;
3856    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3857    You can also run with the option -info and look for messages with the string
3858    malloc in them to see if additional memory allocation was needed.
3859 
3860    Example usage:
3861 
3862    Consider the following 8x8 matrix with 34 non-zero values, that is
3863    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3864    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3865    as follows:
3866 
3867 .vb
3868             1  2  0  |  0  3  0  |  0  4
3869     Proc0   0  5  6  |  7  0  0  |  8  0
3870             9  0 10  | 11  0  0  | 12  0
3871     -------------------------------------
3872            13  0 14  | 15 16 17  |  0  0
3873     Proc1   0 18  0  | 19 20 21  |  0  0
3874             0  0  0  | 22 23  0  | 24  0
3875     -------------------------------------
3876     Proc2  25 26 27  |  0  0 28  | 29  0
3877            30  0  0  | 31 32 33  |  0 34
3878 .ve
3879 
3880    This can be represented as a collection of submatrices as:
3881 
3882 .vb
3883       A B C
3884       D E F
3885       G H I
3886 .ve
3887 
3888    Where the submatrices A,B,C are owned by proc0, D,E,F are
3889    owned by proc1, G,H,I are owned by proc2.
3890 
3891    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3892    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3893    The 'M','N' parameters are 8,8, and have the same values on all procs.
3894 
3895    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3896    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3897    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3898    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3899    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3900    matrix, ans [DF] as another SeqAIJ matrix.
3901 
3902    When d_nz, o_nz parameters are specified, d_nz storage elements are
3903    allocated for every row of the local diagonal submatrix, and o_nz
3904    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3905    One way to choose d_nz and o_nz is to use the max nonzerors per local
3906    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3907    In this case, the values of d_nz,o_nz are:
3908 .vb
3909      proc0 : dnz = 2, o_nz = 2
3910      proc1 : dnz = 3, o_nz = 2
3911      proc2 : dnz = 1, o_nz = 4
3912 .ve
3913    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3914    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3915    for proc3. i.e we are using 12+15+10=37 storage locations to store
3916    34 values.
3917 
3918    When d_nnz, o_nnz parameters are specified, the storage is specified
3919    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3920    In the above case the values for d_nnz,o_nnz are:
3921 .vb
3922      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3923      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3924      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3925 .ve
3926    Here the space allocated is sum of all the above values i.e 34, and
3927    hence pre-allocation is perfect.
3928 
3929    Level: intermediate
3930 
3931 .keywords: matrix, aij, compressed row, sparse, parallel
3932 
3933 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3934           MPIAIJ, MatGetInfo(), PetscSplitOwnership()
3935 @*/
3936 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3937 {
3938   PetscErrorCode ierr;
3939 
3940   PetscFunctionBegin;
3941   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3942   PetscValidType(B,1);
3943   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3944   PetscFunctionReturn(0);
3945 }
3946 
3947 #undef __FUNCT__
3948 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3949 /*@
3950      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3951          CSR format the local rows.
3952 
3953    Collective on MPI_Comm
3954 
3955    Input Parameters:
3956 +  comm - MPI communicator
3957 .  m - number of local rows (Cannot be PETSC_DECIDE)
3958 .  n - This value should be the same as the local size used in creating the
3959        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3960        calculated if N is given) For square matrices n is almost always m.
3961 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3962 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3963 .   i - row indices
3964 .   j - column indices
3965 -   a - matrix values
3966 
3967    Output Parameter:
3968 .   mat - the matrix
3969 
3970    Level: intermediate
3971 
3972    Notes:
3973        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3974      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3975      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3976 
3977        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3978 
3979        The format which is used for the sparse matrix input, is equivalent to a
3980     row-major ordering.. i.e for the following matrix, the input data expected is
3981     as shown:
3982 
3983         1 0 0
3984         2 0 3     P0
3985        -------
3986         4 5 6     P1
3987 
3988      Process0 [P0]: rows_owned=[0,1]
3989         i =  {0,1,3}  [size = nrow+1  = 2+1]
3990         j =  {0,0,2}  [size = nz = 6]
3991         v =  {1,2,3}  [size = nz = 6]
3992 
3993      Process1 [P1]: rows_owned=[2]
3994         i =  {0,3}    [size = nrow+1  = 1+1]
3995         j =  {0,1,2}  [size = nz = 6]
3996         v =  {4,5,6}  [size = nz = 6]
3997 
3998 .keywords: matrix, aij, compressed row, sparse, parallel
3999 
4000 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4001           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
4002 @*/
4003 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
4004 {
4005   PetscErrorCode ierr;
4006 
4007   PetscFunctionBegin;
4008   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
4009   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
4010   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
4011   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
4012   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
4013   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
4014   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4015   PetscFunctionReturn(0);
4016 }
4017 
4018 #undef __FUNCT__
4019 #define __FUNCT__ "MatCreateAIJ"
4020 /*@C
4021    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4022    (the default parallel PETSc format).  For good matrix assembly performance
4023    the user should preallocate the matrix storage by setting the parameters
4024    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4025    performance can be increased by more than a factor of 50.
4026 
4027    Collective on MPI_Comm
4028 
4029    Input Parameters:
4030 +  comm - MPI communicator
4031 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4032            This value should be the same as the local size used in creating the
4033            y vector for the matrix-vector product y = Ax.
4034 .  n - This value should be the same as the local size used in creating the
4035        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4036        calculated if N is given) For square matrices n is almost always m.
4037 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4038 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4039 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4040            (same value is used for all local rows)
4041 .  d_nnz - array containing the number of nonzeros in the various rows of the
4042            DIAGONAL portion of the local submatrix (possibly different for each row)
4043            or NULL, if d_nz is used to specify the nonzero structure.
4044            The size of this array is equal to the number of local rows, i.e 'm'.
4045 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4046            submatrix (same value is used for all local rows).
4047 -  o_nnz - array containing the number of nonzeros in the various rows of the
4048            OFF-DIAGONAL portion of the local submatrix (possibly different for
4049            each row) or NULL, if o_nz is used to specify the nonzero
4050            structure. The size of this array is equal to the number
4051            of local rows, i.e 'm'.
4052 
4053    Output Parameter:
4054 .  A - the matrix
4055 
4056    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4057    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4058    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4059 
4060    Notes:
4061    If the *_nnz parameter is given then the *_nz parameter is ignored
4062 
4063    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4064    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4065    storage requirements for this matrix.
4066 
4067    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4068    processor than it must be used on all processors that share the object for
4069    that argument.
4070 
4071    The user MUST specify either the local or global matrix dimensions
4072    (possibly both).
4073 
4074    The parallel matrix is partitioned across processors such that the
4075    first m0 rows belong to process 0, the next m1 rows belong to
4076    process 1, the next m2 rows belong to process 2 etc.. where
4077    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4078    values corresponding to [m x N] submatrix.
4079 
4080    The columns are logically partitioned with the n0 columns belonging
4081    to 0th partition, the next n1 columns belonging to the next
4082    partition etc.. where n0,n1,n2... are the input parameter 'n'.
4083 
4084    The DIAGONAL portion of the local submatrix on any given processor
4085    is the submatrix corresponding to the rows and columns m,n
4086    corresponding to the given processor. i.e diagonal matrix on
4087    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4088    etc. The remaining portion of the local submatrix [m x (N-n)]
4089    constitute the OFF-DIAGONAL portion. The example below better
4090    illustrates this concept.
4091 
4092    For a square global matrix we define each processor's diagonal portion
4093    to be its local rows and the corresponding columns (a square submatrix);
4094    each processor's off-diagonal portion encompasses the remainder of the
4095    local matrix (a rectangular submatrix).
4096 
4097    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4098 
4099    When calling this routine with a single process communicator, a matrix of
4100    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4101    type of communicator, use the construction mechanism:
4102      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4103 
4104    By default, this format uses inodes (identical nodes) when possible.
4105    We search for consecutive rows with the same nonzero structure, thereby
4106    reusing matrix information to achieve increased efficiency.
4107 
4108    Options Database Keys:
4109 +  -mat_no_inode  - Do not use inodes
4110 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4111 -  -mat_aij_oneindex - Internally use indexing starting at 1
4112         rather than 0.  Note that when calling MatSetValues(),
4113         the user still MUST index entries starting at 0!
4114 
4115 
4116    Example usage:
4117 
4118    Consider the following 8x8 matrix with 34 non-zero values, that is
4119    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4120    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4121    as follows:
4122 
4123 .vb
4124             1  2  0  |  0  3  0  |  0  4
4125     Proc0   0  5  6  |  7  0  0  |  8  0
4126             9  0 10  | 11  0  0  | 12  0
4127     -------------------------------------
4128            13  0 14  | 15 16 17  |  0  0
4129     Proc1   0 18  0  | 19 20 21  |  0  0
4130             0  0  0  | 22 23  0  | 24  0
4131     -------------------------------------
4132     Proc2  25 26 27  |  0  0 28  | 29  0
4133            30  0  0  | 31 32 33  |  0 34
4134 .ve
4135 
4136    This can be represented as a collection of submatrices as:
4137 
4138 .vb
4139       A B C
4140       D E F
4141       G H I
4142 .ve
4143 
4144    Where the submatrices A,B,C are owned by proc0, D,E,F are
4145    owned by proc1, G,H,I are owned by proc2.
4146 
4147    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4148    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4149    The 'M','N' parameters are 8,8, and have the same values on all procs.
4150 
4151    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4152    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4153    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4154    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4155    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4156    matrix, ans [DF] as another SeqAIJ matrix.
4157 
4158    When d_nz, o_nz parameters are specified, d_nz storage elements are
4159    allocated for every row of the local diagonal submatrix, and o_nz
4160    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4161    One way to choose d_nz and o_nz is to use the max nonzerors per local
4162    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4163    In this case, the values of d_nz,o_nz are:
4164 .vb
4165      proc0 : dnz = 2, o_nz = 2
4166      proc1 : dnz = 3, o_nz = 2
4167      proc2 : dnz = 1, o_nz = 4
4168 .ve
4169    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4170    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4171    for proc3. i.e we are using 12+15+10=37 storage locations to store
4172    34 values.
4173 
4174    When d_nnz, o_nnz parameters are specified, the storage is specified
4175    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4176    In the above case the values for d_nnz,o_nnz are:
4177 .vb
4178      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4179      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4180      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4181 .ve
4182    Here the space allocated is sum of all the above values i.e 34, and
4183    hence pre-allocation is perfect.
4184 
4185    Level: intermediate
4186 
4187 .keywords: matrix, aij, compressed row, sparse, parallel
4188 
4189 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4190           MPIAIJ, MatCreateMPIAIJWithArrays()
4191 @*/
4192 PetscErrorCode  MatCreateAIJ(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[],Mat *A)
4193 {
4194   PetscErrorCode ierr;
4195   PetscMPIInt    size;
4196 
4197   PetscFunctionBegin;
4198   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4199   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4200   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4201   if (size > 1) {
4202     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4203     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4204   } else {
4205     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4206     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4207   }
4208   PetscFunctionReturn(0);
4209 }
4210 
4211 #undef __FUNCT__
4212 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
4213 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
4214 {
4215   Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
4216 
4217   PetscFunctionBegin;
4218   if (Ad)     *Ad     = a->A;
4219   if (Ao)     *Ao     = a->B;
4220   if (colmap) *colmap = a->garray;
4221   PetscFunctionReturn(0);
4222 }
4223 
4224 #undef __FUNCT__
4225 #define __FUNCT__ "MatSetColoring_MPIAIJ"
4226 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
4227 {
4228   PetscErrorCode ierr;
4229   PetscInt       i;
4230   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4231 
4232   PetscFunctionBegin;
4233   if (coloring->ctype == IS_COLORING_GLOBAL) {
4234     ISColoringValue *allcolors,*colors;
4235     ISColoring      ocoloring;
4236 
4237     /* set coloring for diagonal portion */
4238     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
4239 
4240     /* set coloring for off-diagonal portion */
4241     ierr = ISAllGatherColors(PetscObjectComm((PetscObject)A),coloring->n,coloring->colors,NULL,&allcolors);CHKERRQ(ierr);
4242     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4243     for (i=0; i<a->B->cmap->n; i++) {
4244       colors[i] = allcolors[a->garray[i]];
4245     }
4246     ierr = PetscFree(allcolors);CHKERRQ(ierr);
4247     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4248     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4249     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4250   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
4251     ISColoringValue *colors;
4252     PetscInt        *larray;
4253     ISColoring      ocoloring;
4254 
4255     /* set coloring for diagonal portion */
4256     ierr = PetscMalloc1((a->A->cmap->n+1),&larray);CHKERRQ(ierr);
4257     for (i=0; i<a->A->cmap->n; i++) {
4258       larray[i] = i + A->cmap->rstart;
4259     }
4260     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,NULL,larray);CHKERRQ(ierr);
4261     ierr = PetscMalloc1((a->A->cmap->n+1),&colors);CHKERRQ(ierr);
4262     for (i=0; i<a->A->cmap->n; i++) {
4263       colors[i] = coloring->colors[larray[i]];
4264     }
4265     ierr = PetscFree(larray);CHKERRQ(ierr);
4266     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4267     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
4268     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4269 
4270     /* set coloring for off-diagonal portion */
4271     ierr = PetscMalloc1((a->B->cmap->n+1),&larray);CHKERRQ(ierr);
4272     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,NULL,larray);CHKERRQ(ierr);
4273     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4274     for (i=0; i<a->B->cmap->n; i++) {
4275       colors[i] = coloring->colors[larray[i]];
4276     }
4277     ierr = PetscFree(larray);CHKERRQ(ierr);
4278     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4279     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4280     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4281   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
4282   PetscFunctionReturn(0);
4283 }
4284 
4285 #undef __FUNCT__
4286 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
4287 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
4288 {
4289   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4290   PetscErrorCode ierr;
4291 
4292   PetscFunctionBegin;
4293   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
4294   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
4295   PetscFunctionReturn(0);
4296 }
4297 
4298 #undef __FUNCT__
4299 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJSymbolic"
4300 PetscErrorCode MatCreateMPIAIJConcatenateSeqAIJSymbolic(MPI_Comm comm,Mat inmat,PetscInt n,Mat *outmat)
4301 {
4302   PetscErrorCode ierr;
4303   PetscInt       m,N,i,rstart,nnz,*dnz,*onz,sum,bs,cbs;
4304   PetscInt       *indx;
4305 
4306   PetscFunctionBegin;
4307   /* This routine will ONLY return MPIAIJ type matrix */
4308   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4309   ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4310   if (n == PETSC_DECIDE) {
4311     ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4312   }
4313   /* Check sum(n) = N */
4314   ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4315   if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4316 
4317   ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4318   rstart -= m;
4319 
4320   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4321   for (i=0; i<m; i++) {
4322     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4323     ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4324     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4325   }
4326 
4327   ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4328   ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4329   ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
4330   ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
4331   ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4332   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4333   PetscFunctionReturn(0);
4334 }
4335 
4336 #undef __FUNCT__
4337 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJNumeric"
4338 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJNumeric(MPI_Comm comm,Mat inmat,PetscInt n,Mat outmat)
4339 {
4340   PetscErrorCode ierr;
4341   PetscInt       m,N,i,rstart,nnz,Ii;
4342   PetscInt       *indx;
4343   PetscScalar    *values;
4344 
4345   PetscFunctionBegin;
4346   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4347   ierr = MatGetOwnershipRange(outmat,&rstart,NULL);CHKERRQ(ierr);
4348   for (i=0; i<m; i++) {
4349     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4350     Ii   = i + rstart;
4351     ierr = MatSetValues(outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4352     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4353   }
4354   ierr = MatAssemblyBegin(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4355   ierr = MatAssemblyEnd(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4356   PetscFunctionReturn(0);
4357 }
4358 
4359 #undef __FUNCT__
4360 #define __FUNCT__ "MatCreateMPIMatConcatenateSeqMat_MPIAIJ"
4361 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4362 {
4363   PetscErrorCode ierr;
4364   PetscMPIInt    size;
4365 
4366   PetscFunctionBegin;
4367   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4368   ierr = PetscLogEventBegin(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4369   if (size == 1) {
4370     if (scall == MAT_INITIAL_MATRIX) {
4371       ierr = MatDuplicate(inmat,MAT_COPY_VALUES,outmat);CHKERRQ(ierr);
4372     } else {
4373       ierr = MatCopy(inmat,*outmat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4374     }
4375   } else {
4376     if (scall == MAT_INITIAL_MATRIX) {
4377       ierr = MatCreateMPIAIJConcatenateSeqAIJSymbolic(comm,inmat,n,outmat);CHKERRQ(ierr);
4378     }
4379     ierr = MatCreateMPIAIJConcatenateSeqAIJNumeric(comm,inmat,n,*outmat);CHKERRQ(ierr);
4380   }
4381   ierr = PetscLogEventEnd(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4382   PetscFunctionReturn(0);
4383 }
4384 
4385 #undef __FUNCT__
4386 #define __FUNCT__ "MatFileSplit"
4387 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4388 {
4389   PetscErrorCode    ierr;
4390   PetscMPIInt       rank;
4391   PetscInt          m,N,i,rstart,nnz;
4392   size_t            len;
4393   const PetscInt    *indx;
4394   PetscViewer       out;
4395   char              *name;
4396   Mat               B;
4397   const PetscScalar *values;
4398 
4399   PetscFunctionBegin;
4400   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4401   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4402   /* Should this be the type of the diagonal block of A? */
4403   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4404   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4405   ierr = MatSetBlockSizesFromMats(B,A,A);CHKERRQ(ierr);
4406   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4407   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
4408   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4409   for (i=0; i<m; i++) {
4410     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4411     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4412     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4413   }
4414   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4415   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4416 
4417   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
4418   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4419   ierr = PetscMalloc1((len+5),&name);CHKERRQ(ierr);
4420   sprintf(name,"%s.%d",outfile,rank);
4421   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4422   ierr = PetscFree(name);CHKERRQ(ierr);
4423   ierr = MatView(B,out);CHKERRQ(ierr);
4424   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4425   ierr = MatDestroy(&B);CHKERRQ(ierr);
4426   PetscFunctionReturn(0);
4427 }
4428 
4429 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
4430 #undef __FUNCT__
4431 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
4432 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4433 {
4434   PetscErrorCode      ierr;
4435   Mat_Merge_SeqsToMPI *merge;
4436   PetscContainer      container;
4437 
4438   PetscFunctionBegin;
4439   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4440   if (container) {
4441     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4442     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4443     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4444     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4445     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4446     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4447     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4448     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4449     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4450     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4451     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4452     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4453     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4454     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4455     ierr = PetscFree(merge);CHKERRQ(ierr);
4456     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4457   }
4458   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4459   PetscFunctionReturn(0);
4460 }
4461 
4462 #include <../src/mat/utils/freespace.h>
4463 #include <petscbt.h>
4464 
4465 #undef __FUNCT__
4466 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
4467 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4468 {
4469   PetscErrorCode      ierr;
4470   MPI_Comm            comm;
4471   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
4472   PetscMPIInt         size,rank,taga,*len_s;
4473   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
4474   PetscInt            proc,m;
4475   PetscInt            **buf_ri,**buf_rj;
4476   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4477   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
4478   MPI_Request         *s_waits,*r_waits;
4479   MPI_Status          *status;
4480   MatScalar           *aa=a->a;
4481   MatScalar           **abuf_r,*ba_i;
4482   Mat_Merge_SeqsToMPI *merge;
4483   PetscContainer      container;
4484 
4485   PetscFunctionBegin;
4486   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
4487   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4488 
4489   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4490   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4491 
4492   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4493   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4494 
4495   bi     = merge->bi;
4496   bj     = merge->bj;
4497   buf_ri = merge->buf_ri;
4498   buf_rj = merge->buf_rj;
4499 
4500   ierr   = PetscMalloc1(size,&status);CHKERRQ(ierr);
4501   owners = merge->rowmap->range;
4502   len_s  = merge->len_s;
4503 
4504   /* send and recv matrix values */
4505   /*-----------------------------*/
4506   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4507   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4508 
4509   ierr = PetscMalloc1((merge->nsend+1),&s_waits);CHKERRQ(ierr);
4510   for (proc=0,k=0; proc<size; proc++) {
4511     if (!len_s[proc]) continue;
4512     i    = owners[proc];
4513     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4514     k++;
4515   }
4516 
4517   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4518   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4519   ierr = PetscFree(status);CHKERRQ(ierr);
4520 
4521   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4522   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4523 
4524   /* insert mat values of mpimat */
4525   /*----------------------------*/
4526   ierr = PetscMalloc1(N,&ba_i);CHKERRQ(ierr);
4527   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4528 
4529   for (k=0; k<merge->nrecv; k++) {
4530     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4531     nrows       = *(buf_ri_k[k]);
4532     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4533     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4534   }
4535 
4536   /* set values of ba */
4537   m = merge->rowmap->n;
4538   for (i=0; i<m; i++) {
4539     arow = owners[rank] + i;
4540     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4541     bnzi = bi[i+1] - bi[i];
4542     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4543 
4544     /* add local non-zero vals of this proc's seqmat into ba */
4545     anzi   = ai[arow+1] - ai[arow];
4546     aj     = a->j + ai[arow];
4547     aa     = a->a + ai[arow];
4548     nextaj = 0;
4549     for (j=0; nextaj<anzi; j++) {
4550       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4551         ba_i[j] += aa[nextaj++];
4552       }
4553     }
4554 
4555     /* add received vals into ba */
4556     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4557       /* i-th row */
4558       if (i == *nextrow[k]) {
4559         anzi   = *(nextai[k]+1) - *nextai[k];
4560         aj     = buf_rj[k] + *(nextai[k]);
4561         aa     = abuf_r[k] + *(nextai[k]);
4562         nextaj = 0;
4563         for (j=0; nextaj<anzi; j++) {
4564           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4565             ba_i[j] += aa[nextaj++];
4566           }
4567         }
4568         nextrow[k]++; nextai[k]++;
4569       }
4570     }
4571     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4572   }
4573   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4574   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4575 
4576   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4577   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4578   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4579   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4580   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4581   PetscFunctionReturn(0);
4582 }
4583 
4584 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4585 
4586 #undef __FUNCT__
4587 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4588 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4589 {
4590   PetscErrorCode      ierr;
4591   Mat                 B_mpi;
4592   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4593   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4594   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4595   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4596   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4597   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4598   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4599   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4600   MPI_Status          *status;
4601   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4602   PetscBT             lnkbt;
4603   Mat_Merge_SeqsToMPI *merge;
4604   PetscContainer      container;
4605 
4606   PetscFunctionBegin;
4607   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4608 
4609   /* make sure it is a PETSc comm */
4610   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4611   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4612   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4613 
4614   ierr = PetscNew(&merge);CHKERRQ(ierr);
4615   ierr = PetscMalloc1(size,&status);CHKERRQ(ierr);
4616 
4617   /* determine row ownership */
4618   /*---------------------------------------------------------*/
4619   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4620   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4621   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4622   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4623   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4624   ierr = PetscMalloc1(size,&len_si);CHKERRQ(ierr);
4625   ierr = PetscMalloc1(size,&merge->len_s);CHKERRQ(ierr);
4626 
4627   m      = merge->rowmap->n;
4628   owners = merge->rowmap->range;
4629 
4630   /* determine the number of messages to send, their lengths */
4631   /*---------------------------------------------------------*/
4632   len_s = merge->len_s;
4633 
4634   len          = 0; /* length of buf_si[] */
4635   merge->nsend = 0;
4636   for (proc=0; proc<size; proc++) {
4637     len_si[proc] = 0;
4638     if (proc == rank) {
4639       len_s[proc] = 0;
4640     } else {
4641       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4642       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4643     }
4644     if (len_s[proc]) {
4645       merge->nsend++;
4646       nrows = 0;
4647       for (i=owners[proc]; i<owners[proc+1]; i++) {
4648         if (ai[i+1] > ai[i]) nrows++;
4649       }
4650       len_si[proc] = 2*(nrows+1);
4651       len         += len_si[proc];
4652     }
4653   }
4654 
4655   /* determine the number and length of messages to receive for ij-structure */
4656   /*-------------------------------------------------------------------------*/
4657   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4658   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4659 
4660   /* post the Irecv of j-structure */
4661   /*-------------------------------*/
4662   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4663   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4664 
4665   /* post the Isend of j-structure */
4666   /*--------------------------------*/
4667   ierr = PetscMalloc2(merge->nsend,&si_waits,merge->nsend,&sj_waits);CHKERRQ(ierr);
4668 
4669   for (proc=0, k=0; proc<size; proc++) {
4670     if (!len_s[proc]) continue;
4671     i    = owners[proc];
4672     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4673     k++;
4674   }
4675 
4676   /* receives and sends of j-structure are complete */
4677   /*------------------------------------------------*/
4678   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4679   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4680 
4681   /* send and recv i-structure */
4682   /*---------------------------*/
4683   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4684   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4685 
4686   ierr   = PetscMalloc1((len+1),&buf_s);CHKERRQ(ierr);
4687   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4688   for (proc=0,k=0; proc<size; proc++) {
4689     if (!len_s[proc]) continue;
4690     /* form outgoing message for i-structure:
4691          buf_si[0]:                 nrows to be sent
4692                [1:nrows]:           row index (global)
4693                [nrows+1:2*nrows+1]: i-structure index
4694     */
4695     /*-------------------------------------------*/
4696     nrows       = len_si[proc]/2 - 1;
4697     buf_si_i    = buf_si + nrows+1;
4698     buf_si[0]   = nrows;
4699     buf_si_i[0] = 0;
4700     nrows       = 0;
4701     for (i=owners[proc]; i<owners[proc+1]; i++) {
4702       anzi = ai[i+1] - ai[i];
4703       if (anzi) {
4704         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4705         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4706         nrows++;
4707       }
4708     }
4709     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4710     k++;
4711     buf_si += len_si[proc];
4712   }
4713 
4714   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4715   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4716 
4717   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4718   for (i=0; i<merge->nrecv; i++) {
4719     ierr = PetscInfo3(seqmat,"recv len_ri=%D, len_rj=%D from [%D]\n",len_ri[i],merge->len_r[i],merge->id_r[i]);CHKERRQ(ierr);
4720   }
4721 
4722   ierr = PetscFree(len_si);CHKERRQ(ierr);
4723   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4724   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4725   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4726   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4727   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4728   ierr = PetscFree(status);CHKERRQ(ierr);
4729 
4730   /* compute a local seq matrix in each processor */
4731   /*----------------------------------------------*/
4732   /* allocate bi array and free space for accumulating nonzero column info */
4733   ierr  = PetscMalloc1((m+1),&bi);CHKERRQ(ierr);
4734   bi[0] = 0;
4735 
4736   /* create and initialize a linked list */
4737   nlnk = N+1;
4738   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4739 
4740   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4741   len  = ai[owners[rank+1]] - ai[owners[rank]];
4742   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4743 
4744   current_space = free_space;
4745 
4746   /* determine symbolic info for each local row */
4747   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4748 
4749   for (k=0; k<merge->nrecv; k++) {
4750     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4751     nrows       = *buf_ri_k[k];
4752     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4753     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4754   }
4755 
4756   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4757   len  = 0;
4758   for (i=0; i<m; i++) {
4759     bnzi = 0;
4760     /* add local non-zero cols of this proc's seqmat into lnk */
4761     arow  = owners[rank] + i;
4762     anzi  = ai[arow+1] - ai[arow];
4763     aj    = a->j + ai[arow];
4764     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4765     bnzi += nlnk;
4766     /* add received col data into lnk */
4767     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4768       if (i == *nextrow[k]) { /* i-th row */
4769         anzi  = *(nextai[k]+1) - *nextai[k];
4770         aj    = buf_rj[k] + *nextai[k];
4771         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4772         bnzi += nlnk;
4773         nextrow[k]++; nextai[k]++;
4774       }
4775     }
4776     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4777 
4778     /* if free space is not available, make more free space */
4779     if (current_space->local_remaining<bnzi) {
4780       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4781       nspacedouble++;
4782     }
4783     /* copy data into free space, then initialize lnk */
4784     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4785     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4786 
4787     current_space->array           += bnzi;
4788     current_space->local_used      += bnzi;
4789     current_space->local_remaining -= bnzi;
4790 
4791     bi[i+1] = bi[i] + bnzi;
4792   }
4793 
4794   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4795 
4796   ierr = PetscMalloc1((bi[m]+1),&bj);CHKERRQ(ierr);
4797   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4798   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4799 
4800   /* create symbolic parallel matrix B_mpi */
4801   /*---------------------------------------*/
4802   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4803   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4804   if (n==PETSC_DECIDE) {
4805     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4806   } else {
4807     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4808   }
4809   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
4810   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4811   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4812   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4813   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4814 
4815   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4816   B_mpi->assembled    = PETSC_FALSE;
4817   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
4818   merge->bi           = bi;
4819   merge->bj           = bj;
4820   merge->buf_ri       = buf_ri;
4821   merge->buf_rj       = buf_rj;
4822   merge->coi          = NULL;
4823   merge->coj          = NULL;
4824   merge->owners_co    = NULL;
4825 
4826   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4827 
4828   /* attach the supporting struct to B_mpi for reuse */
4829   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4830   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4831   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4832   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
4833   *mpimat = B_mpi;
4834 
4835   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4836   PetscFunctionReturn(0);
4837 }
4838 
4839 #undef __FUNCT__
4840 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
4841 /*@C
4842       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
4843                  matrices from each processor
4844 
4845     Collective on MPI_Comm
4846 
4847    Input Parameters:
4848 +    comm - the communicators the parallel matrix will live on
4849 .    seqmat - the input sequential matrices
4850 .    m - number of local rows (or PETSC_DECIDE)
4851 .    n - number of local columns (or PETSC_DECIDE)
4852 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4853 
4854    Output Parameter:
4855 .    mpimat - the parallel matrix generated
4856 
4857     Level: advanced
4858 
4859    Notes:
4860      The dimensions of the sequential matrix in each processor MUST be the same.
4861      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4862      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4863 @*/
4864 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4865 {
4866   PetscErrorCode ierr;
4867   PetscMPIInt    size;
4868 
4869   PetscFunctionBegin;
4870   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4871   if (size == 1) {
4872     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4873     if (scall == MAT_INITIAL_MATRIX) {
4874       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4875     } else {
4876       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4877     }
4878     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4879     PetscFunctionReturn(0);
4880   }
4881   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4882   if (scall == MAT_INITIAL_MATRIX) {
4883     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4884   }
4885   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4886   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4887   PetscFunctionReturn(0);
4888 }
4889 
4890 #undef __FUNCT__
4891 #define __FUNCT__ "MatMPIAIJGetLocalMat"
4892 /*@
4893      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4894           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4895           with MatGetSize()
4896 
4897     Not Collective
4898 
4899    Input Parameters:
4900 +    A - the matrix
4901 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4902 
4903    Output Parameter:
4904 .    A_loc - the local sequential matrix generated
4905 
4906     Level: developer
4907 
4908 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4909 
4910 @*/
4911 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4912 {
4913   PetscErrorCode ierr;
4914   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
4915   Mat_SeqAIJ     *mat,*a,*b;
4916   PetscInt       *ai,*aj,*bi,*bj,*cmap=mpimat->garray;
4917   MatScalar      *aa,*ba,*cam;
4918   PetscScalar    *ca;
4919   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4920   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
4921   PetscBool      match;
4922   MPI_Comm       comm;
4923   PetscMPIInt    size;
4924 
4925   PetscFunctionBegin;
4926   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4927   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4928   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4929   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4930   if (size == 1 && scall == MAT_REUSE_MATRIX) PetscFunctionReturn(0);
4931 
4932   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4933   a = (Mat_SeqAIJ*)(mpimat->A)->data;
4934   b = (Mat_SeqAIJ*)(mpimat->B)->data;
4935   ai = a->i; aj = a->j; bi = b->i; bj = b->j;
4936   aa = a->a; ba = b->a;
4937   if (scall == MAT_INITIAL_MATRIX) {
4938     if (size == 1) {
4939       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ai,aj,aa,A_loc);CHKERRQ(ierr);
4940       PetscFunctionReturn(0);
4941     }
4942 
4943     ierr  = PetscMalloc1((1+am),&ci);CHKERRQ(ierr);
4944     ci[0] = 0;
4945     for (i=0; i<am; i++) {
4946       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4947     }
4948     ierr = PetscMalloc1((1+ci[am]),&cj);CHKERRQ(ierr);
4949     ierr = PetscMalloc1((1+ci[am]),&ca);CHKERRQ(ierr);
4950     k    = 0;
4951     for (i=0; i<am; i++) {
4952       ncols_o = bi[i+1] - bi[i];
4953       ncols_d = ai[i+1] - ai[i];
4954       /* off-diagonal portion of A */
4955       for (jo=0; jo<ncols_o; jo++) {
4956         col = cmap[*bj];
4957         if (col >= cstart) break;
4958         cj[k]   = col; bj++;
4959         ca[k++] = *ba++;
4960       }
4961       /* diagonal portion of A */
4962       for (j=0; j<ncols_d; j++) {
4963         cj[k]   = cstart + *aj++;
4964         ca[k++] = *aa++;
4965       }
4966       /* off-diagonal portion of A */
4967       for (j=jo; j<ncols_o; j++) {
4968         cj[k]   = cmap[*bj++];
4969         ca[k++] = *ba++;
4970       }
4971     }
4972     /* put together the new matrix */
4973     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4974     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4975     /* Since these are PETSc arrays, change flags to free them as necessary. */
4976     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4977     mat->free_a  = PETSC_TRUE;
4978     mat->free_ij = PETSC_TRUE;
4979     mat->nonew   = 0;
4980   } else if (scall == MAT_REUSE_MATRIX) {
4981     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4982     ci = mat->i; cj = mat->j; cam = mat->a;
4983     for (i=0; i<am; i++) {
4984       /* off-diagonal portion of A */
4985       ncols_o = bi[i+1] - bi[i];
4986       for (jo=0; jo<ncols_o; jo++) {
4987         col = cmap[*bj];
4988         if (col >= cstart) break;
4989         *cam++ = *ba++; bj++;
4990       }
4991       /* diagonal portion of A */
4992       ncols_d = ai[i+1] - ai[i];
4993       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4994       /* off-diagonal portion of A */
4995       for (j=jo; j<ncols_o; j++) {
4996         *cam++ = *ba++; bj++;
4997       }
4998     }
4999   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
5000   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
5001   PetscFunctionReturn(0);
5002 }
5003 
5004 #undef __FUNCT__
5005 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
5006 /*@C
5007      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
5008 
5009     Not Collective
5010 
5011    Input Parameters:
5012 +    A - the matrix
5013 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5014 -    row, col - index sets of rows and columns to extract (or NULL)
5015 
5016    Output Parameter:
5017 .    A_loc - the local sequential matrix generated
5018 
5019     Level: developer
5020 
5021 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
5022 
5023 @*/
5024 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
5025 {
5026   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5027   PetscErrorCode ierr;
5028   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
5029   IS             isrowa,iscola;
5030   Mat            *aloc;
5031   PetscBool      match;
5032 
5033   PetscFunctionBegin;
5034   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5035   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5036   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5037   if (!row) {
5038     start = A->rmap->rstart; end = A->rmap->rend;
5039     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
5040   } else {
5041     isrowa = *row;
5042   }
5043   if (!col) {
5044     start = A->cmap->rstart;
5045     cmap  = a->garray;
5046     nzA   = a->A->cmap->n;
5047     nzB   = a->B->cmap->n;
5048     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5049     ncols = 0;
5050     for (i=0; i<nzB; i++) {
5051       if (cmap[i] < start) idx[ncols++] = cmap[i];
5052       else break;
5053     }
5054     imark = i;
5055     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
5056     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
5057     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
5058   } else {
5059     iscola = *col;
5060   }
5061   if (scall != MAT_INITIAL_MATRIX) {
5062     ierr    = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
5063     aloc[0] = *A_loc;
5064   }
5065   ierr   = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
5066   *A_loc = aloc[0];
5067   ierr   = PetscFree(aloc);CHKERRQ(ierr);
5068   if (!row) {
5069     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
5070   }
5071   if (!col) {
5072     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
5073   }
5074   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5075   PetscFunctionReturn(0);
5076 }
5077 
5078 #undef __FUNCT__
5079 #define __FUNCT__ "MatGetBrowsOfAcols"
5080 /*@C
5081     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5082 
5083     Collective on Mat
5084 
5085    Input Parameters:
5086 +    A,B - the matrices in mpiaij format
5087 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5088 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
5089 
5090    Output Parameter:
5091 +    rowb, colb - index sets of rows and columns of B to extract
5092 -    B_seq - the sequential matrix generated
5093 
5094     Level: developer
5095 
5096 @*/
5097 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5098 {
5099   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5100   PetscErrorCode ierr;
5101   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5102   IS             isrowb,iscolb;
5103   Mat            *bseq=NULL;
5104 
5105   PetscFunctionBegin;
5106   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5107     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%D, %D) != (%D,%D)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
5108   }
5109   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5110 
5111   if (scall == MAT_INITIAL_MATRIX) {
5112     start = A->cmap->rstart;
5113     cmap  = a->garray;
5114     nzA   = a->A->cmap->n;
5115     nzB   = a->B->cmap->n;
5116     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5117     ncols = 0;
5118     for (i=0; i<nzB; i++) {  /* row < local row index */
5119       if (cmap[i] < start) idx[ncols++] = cmap[i];
5120       else break;
5121     }
5122     imark = i;
5123     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5124     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5125     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5126     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5127   } else {
5128     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5129     isrowb  = *rowb; iscolb = *colb;
5130     ierr    = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
5131     bseq[0] = *B_seq;
5132   }
5133   ierr   = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5134   *B_seq = bseq[0];
5135   ierr   = PetscFree(bseq);CHKERRQ(ierr);
5136   if (!rowb) {
5137     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5138   } else {
5139     *rowb = isrowb;
5140   }
5141   if (!colb) {
5142     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5143   } else {
5144     *colb = iscolb;
5145   }
5146   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5147   PetscFunctionReturn(0);
5148 }
5149 
5150 #undef __FUNCT__
5151 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
5152 /*
5153     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5154     of the OFF-DIAGONAL portion of local A
5155 
5156     Collective on Mat
5157 
5158    Input Parameters:
5159 +    A,B - the matrices in mpiaij format
5160 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5161 
5162    Output Parameter:
5163 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5164 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5165 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5166 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5167 
5168     Level: developer
5169 
5170 */
5171 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5172 {
5173   VecScatter_MPI_General *gen_to,*gen_from;
5174   PetscErrorCode         ierr;
5175   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5176   Mat_SeqAIJ             *b_oth;
5177   VecScatter             ctx =a->Mvctx;
5178   MPI_Comm               comm;
5179   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5180   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5181   PetscScalar            *rvalues,*svalues;
5182   MatScalar              *b_otha,*bufa,*bufA;
5183   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5184   MPI_Request            *rwaits = NULL,*swaits = NULL;
5185   MPI_Status             *sstatus,rstatus;
5186   PetscMPIInt            jj,size;
5187   PetscInt               *cols,sbs,rbs;
5188   PetscScalar            *vals;
5189 
5190   PetscFunctionBegin;
5191   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
5192   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
5193   if (size == 1) PetscFunctionReturn(0);
5194 
5195   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5196     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%d, %d) != (%d,%d)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
5197   }
5198   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5199   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5200 
5201   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5202   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5203   rvalues  = gen_from->values; /* holds the length of receiving row */
5204   svalues  = gen_to->values;   /* holds the length of sending row */
5205   nrecvs   = gen_from->n;
5206   nsends   = gen_to->n;
5207 
5208   ierr    = PetscMalloc2(nrecvs,&rwaits,nsends,&swaits);CHKERRQ(ierr);
5209   srow    = gen_to->indices;    /* local row index to be sent */
5210   sstarts = gen_to->starts;
5211   sprocs  = gen_to->procs;
5212   sstatus = gen_to->sstatus;
5213   sbs     = gen_to->bs;
5214   rstarts = gen_from->starts;
5215   rprocs  = gen_from->procs;
5216   rbs     = gen_from->bs;
5217 
5218   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5219   if (scall == MAT_INITIAL_MATRIX) {
5220     /* i-array */
5221     /*---------*/
5222     /*  post receives */
5223     for (i=0; i<nrecvs; i++) {
5224       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5225       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5226       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5227     }
5228 
5229     /* pack the outgoing message */
5230     ierr = PetscMalloc2(nsends+1,&sstartsj,nrecvs+1,&rstartsj);CHKERRQ(ierr);
5231 
5232     sstartsj[0] = 0;
5233     rstartsj[0] = 0;
5234     len         = 0; /* total length of j or a array to be sent */
5235     k           = 0;
5236     for (i=0; i<nsends; i++) {
5237       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
5238       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
5239       for (j=0; j<nrows; j++) {
5240         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5241         for (l=0; l<sbs; l++) {
5242           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
5243 
5244           rowlen[j*sbs+l] = ncols;
5245 
5246           len += ncols;
5247           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
5248         }
5249         k++;
5250       }
5251       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5252 
5253       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5254     }
5255     /* recvs and sends of i-array are completed */
5256     i = nrecvs;
5257     while (i--) {
5258       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5259     }
5260     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5261 
5262     /* allocate buffers for sending j and a arrays */
5263     ierr = PetscMalloc1((len+1),&bufj);CHKERRQ(ierr);
5264     ierr = PetscMalloc1((len+1),&bufa);CHKERRQ(ierr);
5265 
5266     /* create i-array of B_oth */
5267     ierr = PetscMalloc1((aBn+2),&b_othi);CHKERRQ(ierr);
5268 
5269     b_othi[0] = 0;
5270     len       = 0; /* total length of j or a array to be received */
5271     k         = 0;
5272     for (i=0; i<nrecvs; i++) {
5273       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5274       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
5275       for (j=0; j<nrows; j++) {
5276         b_othi[k+1] = b_othi[k] + rowlen[j];
5277         len        += rowlen[j]; k++;
5278       }
5279       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5280     }
5281 
5282     /* allocate space for j and a arrrays of B_oth */
5283     ierr = PetscMalloc1((b_othi[aBn]+1),&b_othj);CHKERRQ(ierr);
5284     ierr = PetscMalloc1((b_othi[aBn]+1),&b_otha);CHKERRQ(ierr);
5285 
5286     /* j-array */
5287     /*---------*/
5288     /*  post receives of j-array */
5289     for (i=0; i<nrecvs; i++) {
5290       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5291       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5292     }
5293 
5294     /* pack the outgoing message j-array */
5295     k = 0;
5296     for (i=0; i<nsends; i++) {
5297       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5298       bufJ  = bufj+sstartsj[i];
5299       for (j=0; j<nrows; j++) {
5300         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5301         for (ll=0; ll<sbs; ll++) {
5302           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5303           for (l=0; l<ncols; l++) {
5304             *bufJ++ = cols[l];
5305           }
5306           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5307         }
5308       }
5309       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5310     }
5311 
5312     /* recvs and sends of j-array are completed */
5313     i = nrecvs;
5314     while (i--) {
5315       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5316     }
5317     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5318   } else if (scall == MAT_REUSE_MATRIX) {
5319     sstartsj = *startsj_s;
5320     rstartsj = *startsj_r;
5321     bufa     = *bufa_ptr;
5322     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5323     b_otha   = b_oth->a;
5324   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5325 
5326   /* a-array */
5327   /*---------*/
5328   /*  post receives of a-array */
5329   for (i=0; i<nrecvs; i++) {
5330     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5331     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5332   }
5333 
5334   /* pack the outgoing message a-array */
5335   k = 0;
5336   for (i=0; i<nsends; i++) {
5337     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5338     bufA  = bufa+sstartsj[i];
5339     for (j=0; j<nrows; j++) {
5340       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5341       for (ll=0; ll<sbs; ll++) {
5342         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5343         for (l=0; l<ncols; l++) {
5344           *bufA++ = vals[l];
5345         }
5346         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5347       }
5348     }
5349     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5350   }
5351   /* recvs and sends of a-array are completed */
5352   i = nrecvs;
5353   while (i--) {
5354     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5355   }
5356   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5357   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5358 
5359   if (scall == MAT_INITIAL_MATRIX) {
5360     /* put together the new matrix */
5361     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5362 
5363     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5364     /* Since these are PETSc arrays, change flags to free them as necessary. */
5365     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
5366     b_oth->free_a  = PETSC_TRUE;
5367     b_oth->free_ij = PETSC_TRUE;
5368     b_oth->nonew   = 0;
5369 
5370     ierr = PetscFree(bufj);CHKERRQ(ierr);
5371     if (!startsj_s || !bufa_ptr) {
5372       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5373       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5374     } else {
5375       *startsj_s = sstartsj;
5376       *startsj_r = rstartsj;
5377       *bufa_ptr  = bufa;
5378     }
5379   }
5380   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5381   PetscFunctionReturn(0);
5382 }
5383 
5384 #undef __FUNCT__
5385 #define __FUNCT__ "MatGetCommunicationStructs"
5386 /*@C
5387   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5388 
5389   Not Collective
5390 
5391   Input Parameters:
5392 . A - The matrix in mpiaij format
5393 
5394   Output Parameter:
5395 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5396 . colmap - A map from global column index to local index into lvec
5397 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5398 
5399   Level: developer
5400 
5401 @*/
5402 #if defined(PETSC_USE_CTABLE)
5403 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5404 #else
5405 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5406 #endif
5407 {
5408   Mat_MPIAIJ *a;
5409 
5410   PetscFunctionBegin;
5411   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5412   PetscValidPointer(lvec, 2);
5413   PetscValidPointer(colmap, 3);
5414   PetscValidPointer(multScatter, 4);
5415   a = (Mat_MPIAIJ*) A->data;
5416   if (lvec) *lvec = a->lvec;
5417   if (colmap) *colmap = a->colmap;
5418   if (multScatter) *multScatter = a->Mvctx;
5419   PetscFunctionReturn(0);
5420 }
5421 
5422 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
5423 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
5424 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
5425 #if defined(PETSC_HAVE_ELEMENTAL)
5426 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat,MatType,MatReuse,Mat*);
5427 #endif
5428 
5429 #undef __FUNCT__
5430 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
5431 /*
5432     Computes (B'*A')' since computing B*A directly is untenable
5433 
5434                n                       p                          p
5435         (              )       (              )         (                  )
5436       m (      A       )  *  n (       B      )   =   m (         C        )
5437         (              )       (              )         (                  )
5438 
5439 */
5440 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5441 {
5442   PetscErrorCode ierr;
5443   Mat            At,Bt,Ct;
5444 
5445   PetscFunctionBegin;
5446   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5447   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5448   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5449   ierr = MatDestroy(&At);CHKERRQ(ierr);
5450   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5451   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5452   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5453   PetscFunctionReturn(0);
5454 }
5455 
5456 #undef __FUNCT__
5457 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
5458 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5459 {
5460   PetscErrorCode ierr;
5461   PetscInt       m=A->rmap->n,n=B->cmap->n;
5462   Mat            Cmat;
5463 
5464   PetscFunctionBegin;
5465   if (A->cmap->n != B->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"A->cmap->n %d != B->rmap->n %d\n",A->cmap->n,B->rmap->n);
5466   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
5467   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5468   ierr = MatSetBlockSizesFromMats(Cmat,A,B);CHKERRQ(ierr);
5469   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5470   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
5471   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5472   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5473 
5474   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
5475 
5476   *C = Cmat;
5477   PetscFunctionReturn(0);
5478 }
5479 
5480 /* ----------------------------------------------------------------*/
5481 #undef __FUNCT__
5482 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
5483 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5484 {
5485   PetscErrorCode ierr;
5486 
5487   PetscFunctionBegin;
5488   if (scall == MAT_INITIAL_MATRIX) {
5489     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5490     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5491     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5492   }
5493   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5494   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5495   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5496   PetscFunctionReturn(0);
5497 }
5498 
5499 #if defined(PETSC_HAVE_MUMPS)
5500 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_mumps(Mat,MatFactorType,Mat*);
5501 #endif
5502 #if defined(PETSC_HAVE_PASTIX)
5503 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
5504 #endif
5505 #if defined(PETSC_HAVE_SUPERLU_DIST)
5506 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
5507 #endif
5508 #if defined(PETSC_HAVE_CLIQUE)
5509 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_clique(Mat,MatFactorType,Mat*);
5510 #endif
5511 
5512 /*MC
5513    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5514 
5515    Options Database Keys:
5516 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5517 
5518   Level: beginner
5519 
5520 .seealso: MatCreateAIJ()
5521 M*/
5522 
5523 #undef __FUNCT__
5524 #define __FUNCT__ "MatCreate_MPIAIJ"
5525 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
5526 {
5527   Mat_MPIAIJ     *b;
5528   PetscErrorCode ierr;
5529   PetscMPIInt    size;
5530 
5531   PetscFunctionBegin;
5532   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
5533 
5534   ierr          = PetscNewLog(B,&b);CHKERRQ(ierr);
5535   B->data       = (void*)b;
5536   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5537   B->assembled  = PETSC_FALSE;
5538   B->insertmode = NOT_SET_VALUES;
5539   b->size       = size;
5540 
5541   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
5542 
5543   /* build cache for off array entries formed */
5544   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
5545 
5546   b->donotstash  = PETSC_FALSE;
5547   b->colmap      = 0;
5548   b->garray      = 0;
5549   b->roworiented = PETSC_TRUE;
5550 
5551   /* stuff used for matrix vector multiply */
5552   b->lvec  = NULL;
5553   b->Mvctx = NULL;
5554 
5555   /* stuff for MatGetRow() */
5556   b->rowindices   = 0;
5557   b->rowvalues    = 0;
5558   b->getrowactive = PETSC_FALSE;
5559 
5560   /* flexible pointer used in CUSP/CUSPARSE classes */
5561   b->spptr = NULL;
5562 
5563 #if defined(PETSC_HAVE_MUMPS)
5564   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_mumps_C",MatGetFactor_aij_mumps);CHKERRQ(ierr);
5565 #endif
5566 #if defined(PETSC_HAVE_PASTIX)
5567   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_pastix_C",MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
5568 #endif
5569 #if defined(PETSC_HAVE_SUPERLU_DIST)
5570   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_superlu_dist_C",MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
5571 #endif
5572 #if defined(PETSC_HAVE_CLIQUE)
5573   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_clique_C",MatGetFactor_aij_clique);CHKERRQ(ierr);
5574 #endif
5575   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5576   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5577   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetDiagonalBlock_C",MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5578   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5579   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5580   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5581   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5582   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5583   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5584   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5585 #if defined(PETSC_HAVE_ELEMENTAL)
5586   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_elemental_C",MatConvert_MPIAIJ_Elemental);CHKERRQ(ierr);
5587 #endif
5588   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5589   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5590   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5591   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5592   PetscFunctionReturn(0);
5593 }
5594 
5595 #undef __FUNCT__
5596 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5597 /*@
5598      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5599          and "off-diagonal" part of the matrix in CSR format.
5600 
5601    Collective on MPI_Comm
5602 
5603    Input Parameters:
5604 +  comm - MPI communicator
5605 .  m - number of local rows (Cannot be PETSC_DECIDE)
5606 .  n - This value should be the same as the local size used in creating the
5607        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5608        calculated if N is given) For square matrices n is almost always m.
5609 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5610 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5611 .   i - row indices for "diagonal" portion of matrix
5612 .   j - column indices
5613 .   a - matrix values
5614 .   oi - row indices for "off-diagonal" portion of matrix
5615 .   oj - column indices
5616 -   oa - matrix values
5617 
5618    Output Parameter:
5619 .   mat - the matrix
5620 
5621    Level: advanced
5622 
5623    Notes:
5624        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5625        must free the arrays once the matrix has been destroyed and not before.
5626 
5627        The i and j indices are 0 based
5628 
5629        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5630 
5631        This sets local rows and cannot be used to set off-processor values.
5632 
5633        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5634        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5635        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5636        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5637        keep track of the underlying array. Use MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5638        communication if it is known that only local entries will be set.
5639 
5640 .keywords: matrix, aij, compressed row, sparse, parallel
5641 
5642 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5643           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5644 @*/
5645 PetscErrorCode  MatCreateMPIAIJWithSplitArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt i[],PetscInt j[],PetscScalar a[],PetscInt oi[], PetscInt oj[],PetscScalar oa[],Mat *mat)
5646 {
5647   PetscErrorCode ierr;
5648   Mat_MPIAIJ     *maij;
5649 
5650   PetscFunctionBegin;
5651   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5652   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5653   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5654   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5655   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5656   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5657   maij = (Mat_MPIAIJ*) (*mat)->data;
5658 
5659   (*mat)->preallocated = PETSC_TRUE;
5660 
5661   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5662   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5663 
5664   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5665   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5666 
5667   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5668   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5669   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5670   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5671 
5672   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5673   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5674   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5675   PetscFunctionReturn(0);
5676 }
5677 
5678 /*
5679     Special version for direct calls from Fortran
5680 */
5681 #include <petsc-private/fortranimpl.h>
5682 
5683 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5684 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5685 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5686 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5687 #endif
5688 
5689 /* Change these macros so can be used in void function */
5690 #undef CHKERRQ
5691 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5692 #undef SETERRQ2
5693 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5694 #undef SETERRQ3
5695 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5696 #undef SETERRQ
5697 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5698 
5699 #undef __FUNCT__
5700 #define __FUNCT__ "matsetvaluesmpiaij_"
5701 PETSC_EXTERN void PETSC_STDCALL matsetvaluesmpiaij_(Mat *mmat,PetscInt *mm,const PetscInt im[],PetscInt *mn,const PetscInt in[],const PetscScalar v[],InsertMode *maddv,PetscErrorCode *_ierr)
5702 {
5703   Mat            mat  = *mmat;
5704   PetscInt       m    = *mm, n = *mn;
5705   InsertMode     addv = *maddv;
5706   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5707   PetscScalar    value;
5708   PetscErrorCode ierr;
5709 
5710   MatCheckPreallocated(mat,1);
5711   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5712 
5713 #if defined(PETSC_USE_DEBUG)
5714   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5715 #endif
5716   {
5717     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5718     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5719     PetscBool roworiented = aij->roworiented;
5720 
5721     /* Some Variables required in the macro */
5722     Mat        A                 = aij->A;
5723     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5724     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5725     MatScalar  *aa               = a->a;
5726     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5727     Mat        B                 = aij->B;
5728     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5729     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5730     MatScalar  *ba               = b->a;
5731 
5732     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5733     PetscInt  nonew = a->nonew;
5734     MatScalar *ap1,*ap2;
5735 
5736     PetscFunctionBegin;
5737     for (i=0; i<m; i++) {
5738       if (im[i] < 0) continue;
5739 #if defined(PETSC_USE_DEBUG)
5740       if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
5741 #endif
5742       if (im[i] >= rstart && im[i] < rend) {
5743         row      = im[i] - rstart;
5744         lastcol1 = -1;
5745         rp1      = aj + ai[row];
5746         ap1      = aa + ai[row];
5747         rmax1    = aimax[row];
5748         nrow1    = ailen[row];
5749         low1     = 0;
5750         high1    = nrow1;
5751         lastcol2 = -1;
5752         rp2      = bj + bi[row];
5753         ap2      = ba + bi[row];
5754         rmax2    = bimax[row];
5755         nrow2    = bilen[row];
5756         low2     = 0;
5757         high2    = nrow2;
5758 
5759         for (j=0; j<n; j++) {
5760           if (roworiented) value = v[i*n+j];
5761           else value = v[i+j*m];
5762           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5763           if (in[j] >= cstart && in[j] < cend) {
5764             col = in[j] - cstart;
5765             MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5766           } else if (in[j] < 0) continue;
5767 #if defined(PETSC_USE_DEBUG)
5768           else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
5769 #endif
5770           else {
5771             if (mat->was_assembled) {
5772               if (!aij->colmap) {
5773                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5774               }
5775 #if defined(PETSC_USE_CTABLE)
5776               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5777               col--;
5778 #else
5779               col = aij->colmap[in[j]] - 1;
5780 #endif
5781               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5782                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5783                 col  =  in[j];
5784                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5785                 B     = aij->B;
5786                 b     = (Mat_SeqAIJ*)B->data;
5787                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5788                 rp2   = bj + bi[row];
5789                 ap2   = ba + bi[row];
5790                 rmax2 = bimax[row];
5791                 nrow2 = bilen[row];
5792                 low2  = 0;
5793                 high2 = nrow2;
5794                 bm    = aij->B->rmap->n;
5795                 ba    = b->a;
5796               }
5797             } else col = in[j];
5798             MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5799           }
5800         }
5801       } else if (!aij->donotstash) {
5802         if (roworiented) {
5803           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5804         } else {
5805           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5806         }
5807       }
5808     }
5809   }
5810   PetscFunctionReturnVoid();
5811 }
5812 
5813