xref: /petsc/src/mat/impls/baij/mpi/mpibaij.c (revision 25fdafccf5b8454556b53f7b0ed4394feb23003a)
1 #ifdef PETSC_RCS_HEADER
2 static char vcid[] = "$Id: mpibaij.c,v 1.104 1998/02/18 20:37:17 balay Exp balay $";
3 #endif
4 
5 #include "pinclude/pviewer.h"
6 #include "src/mat/impls/baij/mpi/mpibaij.h"
7 #include "src/vec/vecimpl.h"
8 
9 
10 extern int MatSetUpMultiply_MPIBAIJ(Mat);
11 extern int DisAssemble_MPIBAIJ(Mat);
12 extern int MatIncreaseOverlap_MPIBAIJ(Mat,int,IS *,int);
13 extern int MatGetSubMatrices_MPIBAIJ(Mat,int,IS *,IS *,MatGetSubMatrixCall,Mat **);
14 
15 /*
16      Local utility routine that creates a mapping from the global column
17    number to the local number in the off-diagonal part of the local
18    storage of the matrix.  This is done in a non scable way since the
19    length of colmap equals the global matrix length.
20 */
21 #undef __FUNC__
22 #define __FUNC__ "CreateColmap_MPIBAIJ_Private"
23 static int CreateColmap_MPIBAIJ_Private(Mat mat)
24 {
25   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
26   Mat_SeqBAIJ *B = (Mat_SeqBAIJ*) baij->B->data;
27   int         nbs = B->nbs,i,bs=B->bs;;
28 
29   PetscFunctionBegin;
30   baij->colmap = (int *) PetscMalloc((baij->Nbs+1)*sizeof(int));CHKPTRQ(baij->colmap);
31   PLogObjectMemory(mat,baij->Nbs*sizeof(int));
32   PetscMemzero(baij->colmap,baij->Nbs*sizeof(int));
33   for ( i=0; i<nbs; i++ ) baij->colmap[baij->garray[i]] = i*bs+1;
34   PetscFunctionReturn(0);
35 }
36 
37 #define CHUNKSIZE  10
38 
39 #define  MatSetValues_SeqBAIJ_A_Private(row,col,value,addv) \
40 { \
41  \
42     brow = row/bs;  \
43     rp   = aj + ai[brow]; ap = aa + bs2*ai[brow]; \
44     rmax = aimax[brow]; nrow = ailen[brow]; \
45       bcol = col/bs; \
46       ridx = row % bs; cidx = col % bs; \
47       low = 0; high = nrow; \
48       while (high-low > 3) { \
49         t = (low+high)/2; \
50         if (rp[t] > bcol) high = t; \
51         else              low  = t; \
52       } \
53       for ( _i=low; _i<high; _i++ ) { \
54         if (rp[_i] > bcol) break; \
55         if (rp[_i] == bcol) { \
56           bap  = ap +  bs2*_i + bs*cidx + ridx; \
57           if (addv == ADD_VALUES) *bap += value;  \
58           else                    *bap  = value;  \
59           goto a_noinsert; \
60         } \
61       } \
62       if (a->nonew == 1) goto a_noinsert; \
63       else if (a->nonew == -1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Inserting a new nonzero into matrix"); \
64       if (nrow >= rmax) { \
65         /* there is no extra room in row, therefore enlarge */ \
66         int    new_nz = ai[a->mbs] + CHUNKSIZE,len,*new_i,*new_j; \
67         Scalar *new_a; \
68  \
69         if (a->nonew == -2) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Inserting a new nonzero in the matrix"); \
70  \
71         /* malloc new storage space */ \
72         len     = new_nz*(sizeof(int)+bs2*sizeof(Scalar))+(a->mbs+1)*sizeof(int); \
73         new_a   = (Scalar *) PetscMalloc( len ); CHKPTRQ(new_a); \
74         new_j   = (int *) (new_a + bs2*new_nz); \
75         new_i   = new_j + new_nz; \
76  \
77         /* copy over old data into new slots */ \
78         for ( ii=0; ii<brow+1; ii++ ) {new_i[ii] = ai[ii];} \
79         for ( ii=brow+1; ii<a->mbs+1; ii++ ) {new_i[ii] = ai[ii]+CHUNKSIZE;} \
80         PetscMemcpy(new_j,aj,(ai[brow]+nrow)*sizeof(int)); \
81         len = (new_nz - CHUNKSIZE - ai[brow] - nrow); \
82         PetscMemcpy(new_j+ai[brow]+nrow+CHUNKSIZE,aj+ai[brow]+nrow, \
83                                                            len*sizeof(int)); \
84         PetscMemcpy(new_a,aa,(ai[brow]+nrow)*bs2*sizeof(Scalar)); \
85         PetscMemzero(new_a+bs2*(ai[brow]+nrow),bs2*CHUNKSIZE*sizeof(Scalar)); \
86         PetscMemcpy(new_a+bs2*(ai[brow]+nrow+CHUNKSIZE), \
87                     aa+bs2*(ai[brow]+nrow),bs2*len*sizeof(Scalar));  \
88         /* free up old matrix storage */ \
89         PetscFree(a->a);  \
90         if (!a->singlemalloc) {PetscFree(a->i);PetscFree(a->j);} \
91         aa = a->a = new_a; ai = a->i = new_i; aj = a->j = new_j;  \
92         a->singlemalloc = 1; \
93  \
94         rp   = aj + ai[brow]; ap = aa + bs2*ai[brow]; \
95         rmax = aimax[brow] = aimax[brow] + CHUNKSIZE; \
96         PLogObjectMemory(A,CHUNKSIZE*(sizeof(int) + bs2*sizeof(Scalar))); \
97         a->maxnz += bs2*CHUNKSIZE; \
98         a->reallocs++; \
99         a->nz++; \
100       } \
101       N = nrow++ - 1;  \
102       /* shift up all the later entries in this row */ \
103       for ( ii=N; ii>=_i; ii-- ) { \
104         rp[ii+1] = rp[ii]; \
105         PetscMemcpy(ap+bs2*(ii+1),ap+bs2*(ii),bs2*sizeof(Scalar)); \
106       } \
107       if (N>=_i) PetscMemzero(ap+bs2*_i,bs2*sizeof(Scalar));  \
108       rp[_i]                      = bcol;  \
109       ap[bs2*_i + bs*cidx + ridx] = value;  \
110       a_noinsert:; \
111     ailen[brow] = nrow; \
112 }
113 
114 #define  MatSetValues_SeqBAIJ_B_Private(row,col,value,addv) \
115 { \
116  \
117     brow = row/bs;  \
118     rp   = bj + bi[brow]; ap = ba + bs2*bi[brow]; \
119     rmax = bimax[brow]; nrow = bilen[brow]; \
120       bcol = col/bs; \
121       ridx = row % bs; cidx = col % bs; \
122       low = 0; high = nrow; \
123       while (high-low > 3) { \
124         t = (low+high)/2; \
125         if (rp[t] > bcol) high = t; \
126         else              low  = t; \
127       } \
128       for ( _i=low; _i<high; _i++ ) { \
129         if (rp[_i] > bcol) break; \
130         if (rp[_i] == bcol) { \
131           bap  = ap +  bs2*_i + bs*cidx + ridx; \
132           if (addv == ADD_VALUES) *bap += value;  \
133           else                    *bap  = value;  \
134           goto b_noinsert; \
135         } \
136       } \
137       if (b->nonew == 1) goto b_noinsert; \
138       else if (b->nonew == -1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Inserting a new nonzero into matrix"); \
139       if (nrow >= rmax) { \
140         /* there is no extra room in row, therefore enlarge */ \
141         int    new_nz = bi[b->mbs] + CHUNKSIZE,len,*new_i,*new_j; \
142         Scalar *new_a; \
143  \
144         if (b->nonew == -2) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Inserting a new nonzero in the matrix"); \
145  \
146         /* malloc new storage space */ \
147         len     = new_nz*(sizeof(int)+bs2*sizeof(Scalar))+(b->mbs+1)*sizeof(int); \
148         new_a   = (Scalar *) PetscMalloc( len ); CHKPTRQ(new_a); \
149         new_j   = (int *) (new_a + bs2*new_nz); \
150         new_i   = new_j + new_nz; \
151  \
152         /* copy over old data into new slots */ \
153         for ( ii=0; ii<brow+1; ii++ ) {new_i[ii] = bi[ii];} \
154         for ( ii=brow+1; ii<b->mbs+1; ii++ ) {new_i[ii] = bi[ii]+CHUNKSIZE;} \
155         PetscMemcpy(new_j,bj,(bi[brow]+nrow)*sizeof(int)); \
156         len = (new_nz - CHUNKSIZE - bi[brow] - nrow); \
157         PetscMemcpy(new_j+bi[brow]+nrow+CHUNKSIZE,bj+bi[brow]+nrow, \
158                                                            len*sizeof(int)); \
159         PetscMemcpy(new_a,ba,(bi[brow]+nrow)*bs2*sizeof(Scalar)); \
160         PetscMemzero(new_a+bs2*(bi[brow]+nrow),bs2*CHUNKSIZE*sizeof(Scalar)); \
161         PetscMemcpy(new_a+bs2*(bi[brow]+nrow+CHUNKSIZE), \
162                     ba+bs2*(bi[brow]+nrow),bs2*len*sizeof(Scalar));  \
163         /* free up old matrix storage */ \
164         PetscFree(b->a);  \
165         if (!b->singlemalloc) {PetscFree(b->i);PetscFree(b->j);} \
166         ba = b->a = new_a; bi = b->i = new_i; bj = b->j = new_j;  \
167         b->singlemalloc = 1; \
168  \
169         rp   = bj + bi[brow]; ap = ba + bs2*bi[brow]; \
170         rmax = bimax[brow] = bimax[brow] + CHUNKSIZE; \
171         PLogObjectMemory(B,CHUNKSIZE*(sizeof(int) + bs2*sizeof(Scalar))); \
172         b->maxnz += bs2*CHUNKSIZE; \
173         b->reallocs++; \
174         b->nz++; \
175       } \
176       N = nrow++ - 1;  \
177       /* shift up all the later entries in this row */ \
178       for ( ii=N; ii>=_i; ii-- ) { \
179         rp[ii+1] = rp[ii]; \
180         PetscMemcpy(ap+bs2*(ii+1),ap+bs2*(ii),bs2*sizeof(Scalar)); \
181       } \
182       if (N>=_i) PetscMemzero(ap+bs2*_i,bs2*sizeof(Scalar));  \
183       rp[_i]                      = bcol;  \
184       ap[bs2*_i + bs*cidx + ridx] = value;  \
185       b_noinsert:; \
186     bilen[brow] = nrow; \
187 }
188 
189 #undef __FUNC__
190 #define __FUNC__ "MatSetValues_MPIBAIJ"
191 int MatSetValues_MPIBAIJ(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
192 {
193   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
194   Scalar      value;
195   int         ierr,i,j,row,col;
196   int         roworiented = baij->roworiented,rstart_orig=baij->rstart_bs ;
197   int         rend_orig=baij->rend_bs,cstart_orig=baij->cstart_bs;
198   int         cend_orig=baij->cend_bs,bs=baij->bs;
199 
200   /* Some Variables required in the macro */
201   Mat         A = baij->A;
202   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *) (A)->data;
203   int         *aimax=a->imax,*ai=a->i,*ailen=a->ilen,*aj=a->j;
204   Scalar      *aa=a->a;
205 
206   Mat         B = baij->B;
207   Mat_SeqBAIJ *b = (Mat_SeqBAIJ *) (B)->data;
208   int         *bimax=b->imax,*bi=b->i,*bilen=b->ilen,*bj=b->j;
209   Scalar      *ba=b->a;
210 
211   int         *rp,ii,nrow,_i,rmax,N,brow,bcol;
212   int         low,high,t,ridx,cidx,bs2=a->bs2;
213   Scalar      *ap,*bap;
214 
215   PetscFunctionBegin;
216   for ( i=0; i<m; i++ ) {
217 #if defined(USE_PETSC_BOPT_g)
218     if (im[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative row");
219     if (im[i] >= baij->M) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Row too large");
220 #endif
221     if (im[i] >= rstart_orig && im[i] < rend_orig) {
222       row = im[i] - rstart_orig;
223       for ( j=0; j<n; j++ ) {
224         if (in[j] >= cstart_orig && in[j] < cend_orig){
225           col = in[j] - cstart_orig;
226           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
227           MatSetValues_SeqBAIJ_A_Private(row,col,value,addv);
228           /* ierr = MatSetValues_SeqBAIJ(baij->A,1,&row,1,&col,&value,addv);CHKERRQ(ierr); */
229         }
230 #if defined(USE_PETSC_BOPT_g)
231         else if (in[j] < 0) {SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative column");}
232         else if (in[j] >= baij->N) {SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Col too large");}
233 #endif
234         else {
235           if (mat->was_assembled) {
236             if (!baij->colmap) {
237               ierr = CreateColmap_MPIBAIJ_Private(mat);CHKERRQ(ierr);
238             }
239             col = baij->colmap[in[j]/bs] - 1 + in[j]%bs;
240             if (col < 0 && !((Mat_SeqBAIJ*)(baij->A->data))->nonew) {
241               ierr = DisAssemble_MPIBAIJ(mat); CHKERRQ(ierr);
242               col =  in[j];
243               /* Reinitialize the variables required by MatSetValues_SeqBAIJ_B_Private() */
244               B = baij->B;
245               b = (Mat_SeqBAIJ *) (B)->data;
246               bimax=b->imax;bi=b->i;bilen=b->ilen;bj=b->j;
247               ba=b->a;
248             }
249           } else col = in[j];
250           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
251           MatSetValues_SeqBAIJ_B_Private(row,col,value,addv);
252           /* ierr = MatSetValues_SeqBAIJ(baij->B,1,&row,1,&col,&value,addv);CHKERRQ(ierr); */
253         }
254       }
255     } else {
256       if (roworiented && !baij->donotstash) {
257         ierr = StashValues_Private(&baij->stash,im[i],n,in,v+i*n,addv);CHKERRQ(ierr);
258       } else {
259         if (!baij->donotstash) {
260           row = im[i];
261 	  for ( j=0; j<n; j++ ) {
262 	    ierr = StashValues_Private(&baij->stash,row,1,in+j,v+i+j*m,addv);CHKERRQ(ierr);
263           }
264         }
265       }
266     }
267   }
268   PetscFunctionReturn(0);
269 }
270 
271 extern int MatSetValuesBlocked_SeqBAIJ(Mat,int,int*,int,int*,Scalar*,InsertMode);
272 #undef __FUNC__
273 #define __FUNC__ "MatSetValuesBlocked_MPIBAIJ"
274 int MatSetValuesBlocked_MPIBAIJ(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
275 {
276   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
277   Scalar      *value,*barray=baij->barray;
278   int         ierr,i,j,ii,jj,row,col,k,l;
279   int         roworiented = baij->roworiented,rstart=baij->rstart ;
280   int         rend=baij->rend,cstart=baij->cstart,stepval;
281   int         cend=baij->cend,bs=baij->bs,bs2=baij->bs2;
282 
283   if(!barray) {
284     baij->barray = barray = (Scalar*) PetscMalloc(bs2*sizeof(Scalar)); CHKPTRQ(barray);
285   }
286 
287   if (roworiented) {
288     stepval = (n-1)*bs;
289   } else {
290     stepval = (m-1)*bs;
291   }
292   for ( i=0; i<m; i++ ) {
293 #if defined(USE_PETSC_BOPT_g)
294     if (im[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative row");
295     if (im[i] >= baij->Mbs) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Row too large");
296 #endif
297     if (im[i] >= rstart && im[i] < rend) {
298       row = im[i] - rstart;
299       for ( j=0; j<n; j++ ) {
300         /* If NumCol = 1 then a copy is not required */
301         if ((roworiented) && (n == 1)) {
302           barray = v + i*bs2;
303         } else if((!roworiented) && (m == 1)) {
304           barray = v + j*bs2;
305         } else { /* Here a copy is required */
306           if (roworiented) {
307             value = v + i*(stepval+bs)*bs + j*bs;
308           } else {
309             value = v + j*(stepval+bs)*bs + i*bs;
310           }
311           for ( ii=0; ii<bs; ii++,value+=stepval ) {
312             for (jj=0; jj<bs; jj++ ) {
313               *barray++  = *value++;
314             }
315           }
316           barray -=bs2;
317         }
318 
319         if (in[j] >= cstart && in[j] < cend){
320           col  = in[j] - cstart;
321           ierr = MatSetValuesBlocked_SeqBAIJ(baij->A,1,&row,1,&col,barray,addv);CHKERRQ(ierr);
322         }
323 #if defined(USE_PETSC_BOPT_g)
324         else if (in[j] < 0) {SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative column");}
325         else if (in[j] >= baij->Nbs) {SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Column too large");}
326 #endif
327         else {
328           if (mat->was_assembled) {
329             if (!baij->colmap) {
330               ierr = CreateColmap_MPIBAIJ_Private(mat);CHKERRQ(ierr);
331             }
332 
333 #if defined(USE_PETSC_BOPT_g)
334             if ((baij->colmap[in[j]] - 1) % bs) {SETERRQ(PETSC_ERR_PLIB,0,"Incorrect colmap");}
335 #endif
336             col = (baij->colmap[in[j]] - 1)/bs;
337             if (col < 0 && !((Mat_SeqBAIJ*)(baij->A->data))->nonew) {
338               ierr = DisAssemble_MPIBAIJ(mat); CHKERRQ(ierr);
339               col =  in[j];
340             }
341           }
342           else col = in[j];
343           ierr = MatSetValuesBlocked_SeqBAIJ(baij->B,1,&row,1,&col,barray,addv);CHKERRQ(ierr);
344         }
345       }
346     } else {
347       if (!baij->donotstash) {
348         if (roworiented ) {
349           row   = im[i]*bs;
350           value = v + i*(stepval+bs)*bs;
351           for ( j=0; j<bs; j++,row++ ) {
352             for ( k=0; k<n; k++ ) {
353               for ( col=in[k]*bs,l=0; l<bs; l++,col++) {
354                 ierr = StashValues_Private(&baij->stash,row,1,&col,value++,addv);CHKERRQ(ierr);
355               }
356             }
357           }
358         } else {
359           for ( j=0; j<n; j++ ) {
360             value = v + j*(stepval+bs)*bs + i*bs;
361             col   = in[j]*bs;
362             for ( k=0; k<bs; k++,col++,value+=stepval) {
363               for ( row = im[i]*bs,l=0; l<bs; l++,row++) {
364                 ierr = StashValues_Private(&baij->stash,row,1,&col,value++,addv);CHKERRQ(ierr);
365               }
366             }
367           }
368         }
369       }
370     }
371   }
372   PetscFunctionReturn(0);
373 }
374 #include <math.h>
375 #define HASH_KEY 0.6180339887
376 /* #define HASH1(size,key) ((int)((size)*fmod(((key)*HASH_KEY),1))) */
377 #define HASH(size,key,tmp) (tmp = (key)*HASH_KEY,(int)((size)*(tmp-(int)tmp)))
378 /* #define HASH(size,key,tmp) ((int)((size)*fmod(((key)*HASH_KEY),1))) */
379 #undef __FUNC__
380 #define __FUNC__ "MatSetValues_MPIBAIJ_HT"
381 int MatSetValues_MPIBAIJ_HT(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
382 {
383   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
384   int         ierr,i,j,row,col;
385   int         roworiented = baij->roworiented,rstart_orig=baij->rstart_bs ;
386   int         rend_orig=baij->rend_bs,Nbs=baij->Nbs;
387   int         h1,key,size=baij->ht_size,bs=baij->bs,*HT=baij->ht,idx;
388   double      tmp;
389   Scalar      ** HD = baij->hd,value;
390 #if defined(USE_PETSC_BOPT_g)
391   int         total_ct=baij->ht_total_ct,insert_ct=baij->ht_insert_ct;
392 #endif
393 
394   PetscFunctionBegin;
395 
396   for ( i=0; i<m; i++ ) {
397 #if defined(USE_PETSC_BOPT_g)
398     if (im[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative row");
399     if (im[i] >= baij->M) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Row too large");
400 #endif
401       row = im[i];
402     if (row >= rstart_orig && row < rend_orig) {
403       for ( j=0; j<n; j++ ) {
404         col = in[j];
405         if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
406         /* Look up into the Hash Table */
407         key = (row/bs)*Nbs+(col/bs)+1;
408         h1  = HASH(size,key,tmp);
409 
410 
411         idx = h1;
412 #if defined(USE_PETSC_BOPT_g)
413         insert_ct++;
414         total_ct++;
415         if (HT[idx] != key) {
416           for ( idx=h1; (idx<size) && (HT[idx]!=key); idx++,total_ct++);
417           if (idx == size) {
418             for ( idx=0; (idx<h1) && (HT[idx]!=key); idx++,total_ct++);
419             if (idx == h1) {
420               SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"(row,col) has no entry in the hash table");
421             }
422           }
423         }
424 #else
425         if (HT[idx] != key) {
426           for ( idx=h1; (idx<size) && (HT[idx]!=key); idx++);
427           if (idx == size) {
428             for ( idx=0; (idx<h1) && (HT[idx]!=key); idx++);
429             if (idx == h1) {
430               SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"(row,col) has no entry in the hash table");
431             }
432           }
433         }
434 #endif
435         /* A HASH table entry is found, so insert the values at the correct address */
436         if (addv == ADD_VALUES) *(HD[idx]+ (col % bs)*bs + (row % bs)) += value;
437         else                    *(HD[idx]+ (col % bs)*bs + (row % bs))  = value;
438       }
439     } else {
440       if (roworiented && !baij->donotstash) {
441         ierr = StashValues_Private(&baij->stash,im[i],n,in,v+i*n,addv);CHKERRQ(ierr);
442       } else {
443         if (!baij->donotstash) {
444           row = im[i];
445 	  for ( j=0; j<n; j++ ) {
446 	    ierr = StashValues_Private(&baij->stash,row,1,in+j,v+i+j*m,addv);CHKERRQ(ierr);
447           }
448         }
449       }
450     }
451   }
452 #if defined(USE_PETSC_BOPT_g)
453   baij->ht_total_ct = total_ct;
454   baij->ht_insert_ct = insert_ct;
455 #endif
456   PetscFunctionReturn(0);
457 }
458 
459 #undef __FUNC__
460 #define __FUNC__ "MatSetValuesBlocked_MPIBAIJ_HT"
461 int MatSetValuesBlocked_MPIBAIJ_HT(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
462 {
463   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
464   int         ierr,i,j,ii,jj,row,col,k,l;
465   int         roworiented = baij->roworiented,rstart=baij->rstart ;
466   int         rend=baij->rend,stepval,bs=baij->bs,bs2=baij->bs2;
467   int         h1,key,size=baij->ht_size,idx,*HT=baij->ht,Nbs=baij->Nbs;
468   double      tmp;
469   Scalar      ** HD = baij->hd,*value,*v_t,*baij_a;
470 #if defined(USE_PETSC_BOPT_g)
471   int         total_ct=baij->ht_total_ct,insert_ct=baij->ht_insert_ct;
472 #endif
473 
474   PetscFunctionBegin;
475 
476   if (roworiented) {
477     stepval = (n-1)*bs;
478   } else {
479     stepval = (m-1)*bs;
480   }
481   for ( i=0; i<m; i++ ) {
482 #if defined(USE_PETSC_BOPT_g)
483     if (im[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative row");
484     if (im[i] >= baij->Mbs) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Row too large");
485 #endif
486     row   = im[i];
487     v_t   = v + i*bs2;
488     if (row >= rstart && row < rend) {
489       for ( j=0; j<n; j++ ) {
490         col = in[j];
491 
492         /* Look up into the Hash Table */
493         key = row*Nbs+col+1;
494         h1  = HASH(size,key,tmp);
495 
496         idx = h1;
497 #if defined(USE_PETSC_BOPT_g)
498         total_ct++;
499         insert_ct++;
500        if (HT[idx] != key) {
501           for ( idx=h1; (idx<size) && (HT[idx]!=key); idx++,total_ct++);
502           if (idx == size) {
503             for ( idx=0; (idx<h1) && (HT[idx]!=key); idx++,total_ct++);
504             if (idx == h1) {
505               SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"(row,col) has no entry in the hash table");
506             }
507           }
508         }
509 #else
510         if (HT[idx] != key) {
511           for ( idx=h1; (idx<size) && (HT[idx]!=key); idx++);
512           if (idx == size) {
513             for ( idx=0; (idx<h1) && (HT[idx]!=key); idx++);
514             if (idx == h1) {
515               SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"(row,col) has no entry in the hash table");
516             }
517           }
518         }
519 #endif
520         baij_a = HD[idx];
521         if (roworiented) {
522           /*value = v + i*(stepval+bs)*bs + j*bs;*/
523           /* value = v + (i*(stepval+bs)+j)*bs; */
524           value = v_t;
525           v_t  += bs;
526           if (addv == ADD_VALUES) {
527             for ( ii=0; ii<bs; ii++,value+=stepval) {
528               for ( jj=ii; jj<bs2; jj+=bs ) {
529                 baij_a[jj]  += *value++;
530               }
531             }
532           } else {
533             for ( ii=0; ii<bs; ii++,value+=stepval) {
534               for ( jj=ii; jj<bs2; jj+=bs ) {
535                 baij_a[jj]  = *value++;
536               }
537             }
538           }
539         } else {
540           value = v + j*(stepval+bs)*bs + i*bs;
541           if (addv == ADD_VALUES) {
542             for ( ii=0; ii<bs; ii++,value+=stepval,baij_a+=bs ) {
543               for ( jj=0; jj<bs; jj++ ) {
544                 baij_a[jj]  += *value++;
545               }
546             }
547           } else {
548             for ( ii=0; ii<bs; ii++,value+=stepval,baij_a+=bs ) {
549               for ( jj=0; jj<bs; jj++ ) {
550                 baij_a[jj]  = *value++;
551               }
552             }
553           }
554         }
555       }
556     } else {
557       if (!baij->donotstash) {
558         if (roworiented ) {
559           row   = im[i]*bs;
560           value = v + i*(stepval+bs)*bs;
561           for ( j=0; j<bs; j++,row++ ) {
562             for ( k=0; k<n; k++ ) {
563               for ( col=in[k]*bs,l=0; l<bs; l++,col++) {
564                 ierr = StashValues_Private(&baij->stash,row,1,&col,value++,addv);CHKERRQ(ierr);
565               }
566             }
567           }
568         } else {
569           for ( j=0; j<n; j++ ) {
570             value = v + j*(stepval+bs)*bs + i*bs;
571             col   = in[j]*bs;
572             for ( k=0; k<bs; k++,col++,value+=stepval) {
573               for ( row = im[i]*bs,l=0; l<bs; l++,row++) {
574                 ierr = StashValues_Private(&baij->stash,row,1,&col,value++,addv);CHKERRQ(ierr);
575               }
576             }
577           }
578         }
579       }
580     }
581   }
582 #if defined(USE_PETSC_BOPT_g)
583   baij->ht_total_ct = total_ct;
584   baij->ht_insert_ct = insert_ct;
585 #endif
586   PetscFunctionReturn(0);
587 }
588 
589 #undef __FUNC__
590 #define __FUNC__ "MatGetValues_MPIBAIJ"
591 int MatGetValues_MPIBAIJ(Mat mat,int m,int *idxm,int n,int *idxn,Scalar *v)
592 {
593   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
594   int        bs=baij->bs,ierr,i,j, bsrstart = baij->rstart*bs, bsrend = baij->rend*bs;
595   int        bscstart = baij->cstart*bs, bscend = baij->cend*bs,row,col;
596 
597   PetscFunctionBegin;
598   for ( i=0; i<m; i++ ) {
599     if (idxm[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative row");
600     if (idxm[i] >= baij->M) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Row too large");
601     if (idxm[i] >= bsrstart && idxm[i] < bsrend) {
602       row = idxm[i] - bsrstart;
603       for ( j=0; j<n; j++ ) {
604         if (idxn[j] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Negative column");
605         if (idxn[j] >= baij->N) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Column too large");
606         if (idxn[j] >= bscstart && idxn[j] < bscend){
607           col = idxn[j] - bscstart;
608           ierr = MatGetValues(baij->A,1,&row,1,&col,v+i*n+j); CHKERRQ(ierr);
609         } else {
610           if (!baij->colmap) {
611             ierr = CreateColmap_MPIBAIJ_Private(mat);CHKERRQ(ierr);
612           }
613           if((baij->colmap[idxn[j]/bs]-1 < 0) ||
614              (baij->garray[(baij->colmap[idxn[j]/bs]-1)/bs] != idxn[j]/bs)) *(v+i*n+j) = 0.0;
615           else {
616             col  = (baij->colmap[idxn[j]/bs]-1) + idxn[j]%bs;
617             ierr = MatGetValues(baij->B,1,&row,1,&col,v+i*n+j); CHKERRQ(ierr);
618           }
619         }
620       }
621     } else {
622       SETERRQ(PETSC_ERR_SUP,0,"Only local values currently supported");
623     }
624   }
625  PetscFunctionReturn(0);
626 }
627 
628 #undef __FUNC__
629 #define __FUNC__ "MatNorm_MPIBAIJ"
630 int MatNorm_MPIBAIJ(Mat mat,NormType type,double *norm)
631 {
632   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
633   Mat_SeqBAIJ *amat = (Mat_SeqBAIJ*) baij->A->data, *bmat = (Mat_SeqBAIJ*) baij->B->data;
634   int        ierr, i,bs2=baij->bs2;
635   double     sum = 0.0;
636   Scalar     *v;
637 
638   PetscFunctionBegin;
639   if (baij->size == 1) {
640     ierr =  MatNorm(baij->A,type,norm); CHKERRQ(ierr);
641   } else {
642     if (type == NORM_FROBENIUS) {
643       v = amat->a;
644       for (i=0; i<amat->nz*bs2; i++ ) {
645 #if defined(USE_PETSC_COMPLEX)
646         sum += real(conj(*v)*(*v)); v++;
647 #else
648         sum += (*v)*(*v); v++;
649 #endif
650       }
651       v = bmat->a;
652       for (i=0; i<bmat->nz*bs2; i++ ) {
653 #if defined(USE_PETSC_COMPLEX)
654         sum += real(conj(*v)*(*v)); v++;
655 #else
656         sum += (*v)*(*v); v++;
657 #endif
658       }
659       ierr = MPI_Allreduce(&sum,norm,1,MPI_DOUBLE,MPI_SUM,mat->comm);CHKERRQ(ierr);
660       *norm = sqrt(*norm);
661     } else {
662       SETERRQ(PETSC_ERR_SUP,0,"No support for this norm yet");
663     }
664   }
665   PetscFunctionReturn(0);
666 }
667 
668 #undef __FUNC__
669 #define __FUNC__ "MatAssemblyBegin_MPIBAIJ"
670 int MatAssemblyBegin_MPIBAIJ(Mat mat,MatAssemblyType mode)
671 {
672   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ *) mat->data;
673   MPI_Comm    comm = mat->comm;
674   int         size = baij->size, *owners = baij->rowners,bs=baij->bs;
675   int         rank = baij->rank,tag = mat->tag, *owner,*starts,count,ierr;
676   MPI_Request *send_waits,*recv_waits;
677   int         *nprocs,i,j,idx,*procs,nsends,nreceives,nmax,*work;
678   InsertMode  addv;
679   Scalar      *rvalues,*svalues;
680 
681   PetscFunctionBegin;
682   /* make sure all processors are either in INSERTMODE or ADDMODE */
683   ierr = MPI_Allreduce(&mat->insertmode,&addv,1,MPI_INT,MPI_BOR,comm);CHKERRQ(ierr);
684   if (addv == (ADD_VALUES|INSERT_VALUES)) {
685     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,0,"Some processors inserted others added");
686   }
687   mat->insertmode = addv; /* in case this processor had no cache */
688 
689   /*  first count number of contributors to each processor */
690   nprocs = (int *) PetscMalloc( 2*size*sizeof(int) ); CHKPTRQ(nprocs);
691   PetscMemzero(nprocs,2*size*sizeof(int)); procs = nprocs + size;
692   owner = (int *) PetscMalloc( (baij->stash.n+1)*sizeof(int) ); CHKPTRQ(owner);
693   for ( i=0; i<baij->stash.n; i++ ) {
694     idx = baij->stash.idx[i];
695     for ( j=0; j<size; j++ ) {
696       if (idx >= owners[j]*bs && idx < owners[j+1]*bs) {
697         nprocs[j]++; procs[j] = 1; owner[i] = j; break;
698       }
699     }
700   }
701   nsends = 0;  for ( i=0; i<size; i++ ) { nsends += procs[i];}
702 
703   /* inform other processors of number of messages and max length*/
704   work      = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(work);
705   ierr      = MPI_Allreduce(procs, work,size,MPI_INT,MPI_SUM,comm);CHKERRQ(ierr);
706   nreceives = work[rank];
707   ierr      = MPI_Allreduce( nprocs, work,size,MPI_INT,MPI_MAX,comm);CHKERRQ(ierr);
708   nmax      = work[rank];
709   PetscFree(work);
710 
711   /* post receives:
712        1) each message will consist of ordered pairs
713      (global index,value) we store the global index as a double
714      to simplify the message passing.
715        2) since we don't know how long each individual message is we
716      allocate the largest needed buffer for each receive. Potentially
717      this is a lot of wasted space.
718 
719 
720        This could be done better.
721   */
722   rvalues = (Scalar *) PetscMalloc(3*(nreceives+1)*(nmax+1)*sizeof(Scalar));CHKPTRQ(rvalues);
723   recv_waits = (MPI_Request *) PetscMalloc((nreceives+1)*sizeof(MPI_Request));CHKPTRQ(recv_waits);
724   for ( i=0; i<nreceives; i++ ) {
725     ierr = MPI_Irecv(rvalues+3*nmax*i,3*nmax,MPIU_SCALAR,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
726   }
727 
728   /* do sends:
729       1) starts[i] gives the starting index in svalues for stuff going to
730          the ith processor
731   */
732   svalues = (Scalar *) PetscMalloc(3*(baij->stash.n+1)*sizeof(Scalar));CHKPTRQ(svalues);
733   send_waits = (MPI_Request *) PetscMalloc((nsends+1)*sizeof(MPI_Request));CHKPTRQ(send_waits);
734   starts = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(starts);
735   starts[0] = 0;
736   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
737   for ( i=0; i<baij->stash.n; i++ ) {
738     svalues[3*starts[owner[i]]]       = (Scalar)  baij->stash.idx[i];
739     svalues[3*starts[owner[i]]+1]     = (Scalar)  baij->stash.idy[i];
740     svalues[3*(starts[owner[i]]++)+2] =  baij->stash.array[i];
741   }
742   PetscFree(owner);
743   starts[0] = 0;
744   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
745   count = 0;
746   for ( i=0; i<size; i++ ) {
747     if (procs[i]) {
748       ierr = MPI_Isend(svalues+3*starts[i],3*nprocs[i],MPIU_SCALAR,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
749     }
750   }
751   PetscFree(starts); PetscFree(nprocs);
752 
753   /* Free cache space */
754   PLogInfo(0,"MatAssemblyBegin_MPIBAIJ:Number of off-processor values %d\n",baij->stash.n);
755   ierr = StashDestroy_Private(&baij->stash); CHKERRQ(ierr);
756 
757   baij->svalues    = svalues;    baij->rvalues    = rvalues;
758   baij->nsends     = nsends;     baij->nrecvs     = nreceives;
759   baij->send_waits = send_waits; baij->recv_waits = recv_waits;
760   baij->rmax       = nmax;
761 
762   PetscFunctionReturn(0);
763 }
764 
765 /*
766   Creates the hash table, and sets the table
767   This table is created only once.
768   If new entried need to be added to the matrix
769   then the hash table has to be destroyed and
770   recreated.
771 */
772 #undef __FUNC__
773 #define __FUNC__ "MatCreateHashTable_MPIBAIJ_Private"
774 int MatCreateHashTable_MPIBAIJ_Private(Mat mat,double factor)
775 {
776   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
777   Mat         A = baij->A, B=baij->B;
778   Mat_SeqBAIJ *a=(Mat_SeqBAIJ *)A->data, *b=(Mat_SeqBAIJ *)B->data;
779   int         i,j,k,nz=a->nz+b->nz,h1,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j;
780   int         size,bs2=baij->bs2,rstart=baij->rstart;
781   int         cstart=baij->cstart,*garray=baij->garray,row,col,Nbs=baij->Nbs;
782   int         *HT,key;
783   Scalar      **HD;
784   double      tmp;
785 #if defined(USE_PETSC_BOPT_g)
786   int         ct=0,max=0;
787 #endif
788 
789   PetscFunctionBegin;
790   baij->ht_size=(int)(factor*nz);
791   size = baij->ht_size;
792 
793   if (baij->ht) {
794     PetscFunctionReturn(0);
795   }
796 
797   /* Allocate Memory for Hash Table */
798   baij->hd = (Scalar**)PetscMalloc((size)*(sizeof(int)+sizeof(Scalar*))+1); CHKPTRQ(baij->hd);
799   baij->ht = (int*)(baij->hd + size);
800   HD = baij->hd;
801   HT = baij->ht;
802 
803 
804   PetscMemzero(HD,size*(sizeof(int)+sizeof(Scalar*)));
805 
806 
807   /* Loop Over A */
808   for ( i=0; i<a->mbs; i++ ) {
809     for ( j=ai[i]; j<ai[i+1]; j++ ) {
810       row = i+rstart;
811       col = aj[j]+cstart;
812 
813       key = row*Nbs + col + 1;
814       h1  = HASH(size,key,tmp);
815       for ( k=0; k<size; k++ ){
816         if (HT[(h1+k)%size] == 0.0) {
817           HT[(h1+k)%size] = key;
818           HD[(h1+k)%size] = a->a + j*bs2;
819           break;
820 #if defined(USE_PETSC_BOPT_g)
821         } else {
822           ct++;
823 #endif
824         }
825       }
826 #if defined(USE_PETSC_BOPT_g)
827       if (k> max) max = k;
828 #endif
829     }
830   }
831   /* Loop Over B */
832   for ( i=0; i<b->mbs; i++ ) {
833     for ( j=bi[i]; j<bi[i+1]; j++ ) {
834       row = i+rstart;
835       col = garray[bj[j]];
836       key = row*Nbs + col + 1;
837       h1  = HASH(size,key,tmp);
838       for ( k=0; k<size; k++ ){
839         if (HT[(h1+k)%size] == 0.0) {
840           HT[(h1+k)%size] = key;
841           HD[(h1+k)%size] = b->a + j*bs2;
842           break;
843 #if defined(USE_PETSC_BOPT_g)
844         } else {
845           ct++;
846 #endif
847         }
848       }
849 #if defined(USE_PETSC_BOPT_g)
850       if (k> max) max = k;
851 #endif
852     }
853   }
854 
855   /* Print Summary */
856 #if defined(USE_PETSC_BOPT_g)
857   for ( i=0,j=0; i<size; i++)
858     if (HT[i]) {j++;}
859   PLogInfo(0,"MatCreateHashTable_MPIBAIJ_Private: Average Search = %5.2f,max search = %d\n",
860            (j== 0)? 0.0:((double)(ct+j))/j,max);
861 #endif
862   PetscFunctionReturn(0);
863 }
864 
865 #undef __FUNC__
866 #define __FUNC__ "MatAssemblyEnd_MPIBAIJ"
867 int MatAssemblyEnd_MPIBAIJ(Mat mat,MatAssemblyType mode)
868 {
869   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
870   MPI_Status  *send_status,recv_status;
871   int         imdex,nrecvs = baij->nrecvs, count = nrecvs, i, n, ierr;
872   int         bs=baij->bs,row,col,other_disassembled,flg;
873   Scalar      *values,val;
874   InsertMode  addv = mat->insertmode;
875 
876   PetscFunctionBegin;
877   /*  wait on receives */
878   while (count) {
879     ierr = MPI_Waitany(nrecvs,baij->recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
880     /* unpack receives into our local space */
881     values = baij->rvalues + 3*imdex*baij->rmax;
882     ierr = MPI_Get_count(&recv_status,MPIU_SCALAR,&n);CHKERRQ(ierr);
883     n = n/3;
884     for ( i=0; i<n; i++ ) {
885       row = (int) PetscReal(values[3*i]) - baij->rstart*bs;
886       col = (int) PetscReal(values[3*i+1]);
887       val = values[3*i+2];
888       if (col >= baij->cstart*bs && col < baij->cend*bs) {
889         col -= baij->cstart*bs;
890         ierr = MatSetValues(baij->A,1,&row,1,&col,&val,addv); CHKERRQ(ierr)
891       } else {
892         if (mat->was_assembled) {
893           if (!baij->colmap) {
894             ierr = CreateColmap_MPIBAIJ_Private(mat); CHKERRQ(ierr);
895           }
896           col = (baij->colmap[col/bs]) - 1 + col%bs;
897           if (col < 0  && !((Mat_SeqBAIJ*)(baij->A->data))->nonew) {
898             ierr = DisAssemble_MPIBAIJ(mat); CHKERRQ(ierr);
899             col = (int) PetscReal(values[3*i+1]);
900           }
901         }
902         ierr = MatSetValues(baij->B,1,&row,1,&col,&val,addv); CHKERRQ(ierr)
903       }
904     }
905     count--;
906   }
907   PetscFree(baij->recv_waits); PetscFree(baij->rvalues);
908 
909   /* wait on sends */
910   if (baij->nsends) {
911     send_status = (MPI_Status *) PetscMalloc(baij->nsends*sizeof(MPI_Status));CHKPTRQ(send_status);
912     ierr        = MPI_Waitall(baij->nsends,baij->send_waits,send_status);CHKERRQ(ierr);
913     PetscFree(send_status);
914   }
915   PetscFree(baij->send_waits); PetscFree(baij->svalues);
916 
917   ierr = MatAssemblyBegin(baij->A,mode); CHKERRQ(ierr);
918   ierr = MatAssemblyEnd(baij->A,mode); CHKERRQ(ierr);
919 
920   /* determine if any processor has disassembled, if so we must
921      also disassemble ourselfs, in order that we may reassemble. */
922   ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPI_INT,MPI_PROD,mat->comm);CHKERRQ(ierr);
923   if (mat->was_assembled && !other_disassembled) {
924     ierr = DisAssemble_MPIBAIJ(mat); CHKERRQ(ierr);
925   }
926 
927   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
928     ierr = MatSetUpMultiply_MPIBAIJ(mat); CHKERRQ(ierr);
929   }
930   ierr = MatAssemblyBegin(baij->B,mode); CHKERRQ(ierr);
931   ierr = MatAssemblyEnd(baij->B,mode); CHKERRQ(ierr);
932 
933 #if defined(USE_PETSC_BOPT_g)
934   if (baij->ht && mode== MAT_FINAL_ASSEMBLY) {
935     PLogInfo(0,"MatAssemblyEnd_MPIBAIJ:Average Hash Table Search in MatSetValues = %5.2f\n",
936              ((double)baij->ht_total_ct)/baij->ht_insert_ct);
937     baij->ht_total_ct  = 0;
938     baij->ht_insert_ct = 0;
939   }
940 #endif
941   if (baij->ht_flag && !baij->ht && mode == MAT_FINAL_ASSEMBLY) {
942     ierr = MatCreateHashTable_MPIBAIJ_Private(mat,baij->ht_fact); CHKERRQ(ierr);
943     mat->ops.setvalues        = MatSetValues_MPIBAIJ_HT;
944     mat->ops.setvaluesblocked = MatSetValuesBlocked_MPIBAIJ_HT;
945   }
946 
947   if (baij->rowvalues) {PetscFree(baij->rowvalues); baij->rowvalues = 0;}
948   PetscFunctionReturn(0);
949 }
950 
951 #undef __FUNC__
952 #define __FUNC__ "MatView_MPIBAIJ_Binary"
953 static int MatView_MPIBAIJ_Binary(Mat mat,Viewer viewer)
954 {
955   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ *) mat->data;
956   int          ierr;
957 
958   PetscFunctionBegin;
959   if (baij->size == 1) {
960     ierr = MatView(baij->A,viewer); CHKERRQ(ierr);
961   } else SETERRQ(PETSC_ERR_SUP,0,"Only uniprocessor output supported");
962   PetscFunctionReturn(0);
963 }
964 
965 #undef __FUNC__
966 #define __FUNC__ "MatView_MPIBAIJ_ASCIIorDraworMatlab"
967 static int MatView_MPIBAIJ_ASCIIorDraworMatlab(Mat mat,Viewer viewer)
968 {
969   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ *) mat->data;
970   int          ierr, format,rank,bs = baij->bs;
971   FILE         *fd;
972   ViewerType   vtype;
973 
974   PetscFunctionBegin;
975   ierr = ViewerGetType(viewer,&vtype); CHKERRQ(ierr);
976   if (vtype  == ASCII_FILES_VIEWER || vtype == ASCII_FILE_VIEWER) {
977     ierr = ViewerGetFormat(viewer,&format);
978     if (format == VIEWER_FORMAT_ASCII_INFO_LONG) {
979       MatInfo info;
980       MPI_Comm_rank(mat->comm,&rank);
981       ierr = ViewerASCIIGetPointer(viewer,&fd); CHKERRQ(ierr);
982       ierr = MatGetInfo(mat,MAT_LOCAL,&info);
983       PetscSequentialPhaseBegin(mat->comm,1);
984       fprintf(fd,"[%d] Local rows %d nz %d nz alloced %d bs %d mem %d\n",
985               rank,baij->m,(int)info.nz_used*bs,(int)info.nz_allocated*bs,
986               baij->bs,(int)info.memory);
987       ierr = MatGetInfo(baij->A,MAT_LOCAL,&info);
988       fprintf(fd,"[%d] on-diagonal part: nz %d \n",rank,(int)info.nz_used*bs);
989       ierr = MatGetInfo(baij->B,MAT_LOCAL,&info);
990       fprintf(fd,"[%d] off-diagonal part: nz %d \n",rank,(int)info.nz_used*bs);
991       fflush(fd);
992       PetscSequentialPhaseEnd(mat->comm,1);
993       ierr = VecScatterView(baij->Mvctx,viewer); CHKERRQ(ierr);
994       PetscFunctionReturn(0);
995     } else if (format == VIEWER_FORMAT_ASCII_INFO) {
996       PetscPrintf(mat->comm,"  block size is %d\n",bs);
997       PetscFunctionReturn(0);
998     }
999   }
1000 
1001   if (vtype == DRAW_VIEWER) {
1002     Draw       draw;
1003     PetscTruth isnull;
1004     ierr = ViewerDrawGetDraw(viewer,&draw); CHKERRQ(ierr);
1005     ierr = DrawIsNull(draw,&isnull); CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1006   }
1007 
1008   if (vtype == ASCII_FILE_VIEWER) {
1009     ierr = ViewerASCIIGetPointer(viewer,&fd); CHKERRQ(ierr);
1010     PetscSequentialPhaseBegin(mat->comm,1);
1011     fprintf(fd,"[%d] rows %d starts %d ends %d cols %d starts %d ends %d\n",
1012            baij->rank,baij->m,baij->rstart*bs,baij->rend*bs,baij->n,
1013             baij->cstart*bs,baij->cend*bs);
1014     ierr = MatView(baij->A,viewer); CHKERRQ(ierr);
1015     ierr = MatView(baij->B,viewer); CHKERRQ(ierr);
1016     fflush(fd);
1017     PetscSequentialPhaseEnd(mat->comm,1);
1018   } else {
1019     int size = baij->size;
1020     rank = baij->rank;
1021     if (size == 1) {
1022       ierr = MatView(baij->A,viewer); CHKERRQ(ierr);
1023     } else {
1024       /* assemble the entire matrix onto first processor. */
1025       Mat         A;
1026       Mat_SeqBAIJ *Aloc;
1027       int         M = baij->M, N = baij->N,*ai,*aj,row,col,i,j,k,*rvals;
1028       int         mbs=baij->mbs;
1029       Scalar      *a;
1030 
1031       if (!rank) {
1032         ierr = MatCreateMPIBAIJ(mat->comm,baij->bs,M,N,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);CHKERRQ(ierr);
1033       } else {
1034         ierr = MatCreateMPIBAIJ(mat->comm,baij->bs,0,0,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);CHKERRQ(ierr);
1035       }
1036       PLogObjectParent(mat,A);
1037 
1038       /* copy over the A part */
1039       Aloc = (Mat_SeqBAIJ*) baij->A->data;
1040       ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1041       row = baij->rstart;
1042       rvals = (int *) PetscMalloc(bs*sizeof(int)); CHKPTRQ(rvals);
1043 
1044       for ( i=0; i<mbs; i++ ) {
1045         rvals[0] = bs*(baij->rstart + i);
1046         for ( j=1; j<bs; j++ ) { rvals[j] = rvals[j-1] + 1; }
1047         for ( j=ai[i]; j<ai[i+1]; j++ ) {
1048           col = (baij->cstart+aj[j])*bs;
1049           for (k=0; k<bs; k++ ) {
1050             ierr = MatSetValues(A,bs,rvals,1,&col,a,INSERT_VALUES);CHKERRQ(ierr);
1051             col++; a += bs;
1052           }
1053         }
1054       }
1055       /* copy over the B part */
1056       Aloc = (Mat_SeqBAIJ*) baij->B->data;
1057       ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1058       row = baij->rstart*bs;
1059       for ( i=0; i<mbs; i++ ) {
1060         rvals[0] = bs*(baij->rstart + i);
1061         for ( j=1; j<bs; j++ ) { rvals[j] = rvals[j-1] + 1; }
1062         for ( j=ai[i]; j<ai[i+1]; j++ ) {
1063           col = baij->garray[aj[j]]*bs;
1064           for (k=0; k<bs; k++ ) {
1065             ierr = MatSetValues(A,bs,rvals,1,&col,a,INSERT_VALUES);CHKERRQ(ierr);
1066             col++; a += bs;
1067           }
1068         }
1069       }
1070       PetscFree(rvals);
1071       ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1072       ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1073       /*
1074          Everyone has to call to draw the matrix since the graphics waits are
1075          synchronized across all processors that share the Draw object
1076       */
1077       if (!rank || vtype == DRAW_VIEWER) {
1078         ierr = MatView(((Mat_MPIBAIJ*)(A->data))->A,viewer); CHKERRQ(ierr);
1079       }
1080       ierr = MatDestroy(A); CHKERRQ(ierr);
1081     }
1082   }
1083   PetscFunctionReturn(0);
1084 }
1085 
1086 
1087 
1088 #undef __FUNC__
1089 #define __FUNC__ "MatView_MPIBAIJ"
1090 int MatView_MPIBAIJ(PetscObject obj,Viewer viewer)
1091 {
1092   Mat         mat = (Mat) obj;
1093   int         ierr;
1094   ViewerType  vtype;
1095 
1096   PetscFunctionBegin;
1097   ierr = ViewerGetType(viewer,&vtype); CHKERRQ(ierr);
1098   if (vtype == ASCII_FILE_VIEWER || vtype == ASCII_FILES_VIEWER ||
1099       vtype == DRAW_VIEWER       || vtype == MATLAB_VIEWER) {
1100     ierr = MatView_MPIBAIJ_ASCIIorDraworMatlab(mat,viewer); CHKERRQ(ierr);
1101   } else if (vtype == BINARY_FILE_VIEWER) {
1102     ierr = MatView_MPIBAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1103   }
1104   PetscFunctionReturn(0);
1105 }
1106 
1107 #undef __FUNC__
1108 #define __FUNC__ "MatDestroy_MPIBAIJ"
1109 int MatDestroy_MPIBAIJ(PetscObject obj)
1110 {
1111   Mat         mat = (Mat) obj;
1112   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
1113   int         ierr;
1114 
1115   PetscFunctionBegin;
1116 #if defined(USE_PETSC_LOG)
1117   PLogObjectState(obj,"Rows=%d, Cols=%d",baij->M,baij->N);
1118 #endif
1119 
1120   ierr = StashDestroy_Private(&baij->stash); CHKERRQ(ierr);
1121   PetscFree(baij->rowners);
1122   ierr = MatDestroy(baij->A); CHKERRQ(ierr);
1123   ierr = MatDestroy(baij->B); CHKERRQ(ierr);
1124   if (baij->colmap) PetscFree(baij->colmap);
1125   if (baij->garray) PetscFree(baij->garray);
1126   if (baij->lvec)   VecDestroy(baij->lvec);
1127   if (baij->Mvctx)  VecScatterDestroy(baij->Mvctx);
1128   if (baij->rowvalues) PetscFree(baij->rowvalues);
1129   if (baij->barray) PetscFree(baij->barray);
1130   if (baij->hd) PetscFree(baij->hd);
1131   PetscFree(baij);
1132   PLogObjectDestroy(mat);
1133   PetscHeaderDestroy(mat);
1134   PetscFunctionReturn(0);
1135 }
1136 
1137 #undef __FUNC__
1138 #define __FUNC__ "MatMult_MPIBAIJ"
1139 int MatMult_MPIBAIJ(Mat A,Vec xx,Vec yy)
1140 {
1141   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1142   int         ierr, nt;
1143 
1144   PetscFunctionBegin;
1145   VecGetLocalSize_Fast(xx,nt);
1146   if (nt != a->n) {
1147     SETERRQ(PETSC_ERR_ARG_SIZ,0,"Incompatible partition of A and xx");
1148   }
1149   VecGetLocalSize_Fast(yy,nt);
1150   if (nt != a->m) {
1151     SETERRQ(PETSC_ERR_ARG_SIZ,0,"Incompatible parition of A and yy");
1152   }
1153   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
1154   ierr = (*a->A->ops.mult)(a->A,xx,yy); CHKERRQ(ierr);
1155   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
1156   ierr = (*a->B->ops.multadd)(a->B,a->lvec,yy,yy); CHKERRQ(ierr);
1157   ierr = VecScatterPostRecvs(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
1158   PetscFunctionReturn(0);
1159 }
1160 
1161 #undef __FUNC__
1162 #define __FUNC__ "MatMultAdd_MPIBAIJ"
1163 int MatMultAdd_MPIBAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1164 {
1165   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1166   int        ierr;
1167 
1168   PetscFunctionBegin;
1169   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
1170   ierr = (*a->A->ops.multadd)(a->A,xx,yy,zz); CHKERRQ(ierr);
1171   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
1172   ierr = (*a->B->ops.multadd)(a->B,a->lvec,zz,zz); CHKERRQ(ierr);
1173   PetscFunctionReturn(0);
1174 }
1175 
1176 #undef __FUNC__
1177 #define __FUNC__ "MatMultTrans_MPIBAIJ"
1178 int MatMultTrans_MPIBAIJ(Mat A,Vec xx,Vec yy)
1179 {
1180   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1181   int         ierr;
1182 
1183   PetscFunctionBegin;
1184   /* do nondiagonal part */
1185   ierr = (*a->B->ops.multtrans)(a->B,xx,a->lvec); CHKERRQ(ierr);
1186   /* send it on its way */
1187   ierr = VecScatterBegin(a->lvec,yy,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
1188   /* do local part */
1189   ierr = (*a->A->ops.multtrans)(a->A,xx,yy); CHKERRQ(ierr);
1190   /* receive remote parts: note this assumes the values are not actually */
1191   /* inserted in yy until the next line, which is true for my implementation*/
1192   /* but is not perhaps always true. */
1193   ierr = VecScatterEnd(a->lvec,yy,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
1194   PetscFunctionReturn(0);
1195 }
1196 
1197 #undef __FUNC__
1198 #define __FUNC__ "MatMultTransAdd_MPIBAIJ"
1199 int MatMultTransAdd_MPIBAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1200 {
1201   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1202   int         ierr;
1203 
1204   PetscFunctionBegin;
1205   /* do nondiagonal part */
1206   ierr = (*a->B->ops.multtrans)(a->B,xx,a->lvec); CHKERRQ(ierr);
1207   /* send it on its way */
1208   ierr = VecScatterBegin(a->lvec,zz,ADD_VALUES,SCATTER_REVERSE,a->Mvctx); CHKERRQ(ierr);
1209   /* do local part */
1210   ierr = (*a->A->ops.multtransadd)(a->A,xx,yy,zz); CHKERRQ(ierr);
1211   /* receive remote parts: note this assumes the values are not actually */
1212   /* inserted in yy until the next line, which is true for my implementation*/
1213   /* but is not perhaps always true. */
1214   ierr = VecScatterEnd(a->lvec,zz,ADD_VALUES,SCATTER_REVERSE,a->Mvctx); CHKERRQ(ierr);
1215   PetscFunctionReturn(0);
1216 }
1217 
1218 /*
1219   This only works correctly for square matrices where the subblock A->A is the
1220    diagonal block
1221 */
1222 #undef __FUNC__
1223 #define __FUNC__ "MatGetDiagonal_MPIBAIJ"
1224 int MatGetDiagonal_MPIBAIJ(Mat A,Vec v)
1225 {
1226   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1227   int         ierr;
1228 
1229   PetscFunctionBegin;
1230   if (a->M != a->N) SETERRQ(PETSC_ERR_SUP,0,"Supports only square matrix where A->A is diag block");
1231   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1232   PetscFunctionReturn(0);
1233 }
1234 
1235 #undef __FUNC__
1236 #define __FUNC__ "MatScale_MPIBAIJ"
1237 int MatScale_MPIBAIJ(Scalar *aa,Mat A)
1238 {
1239   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1240   int         ierr;
1241 
1242   PetscFunctionBegin;
1243   ierr = MatScale(aa,a->A); CHKERRQ(ierr);
1244   ierr = MatScale(aa,a->B); CHKERRQ(ierr);
1245   PetscFunctionReturn(0);
1246 }
1247 
1248 #undef __FUNC__
1249 #define __FUNC__ "MatGetSize_MPIBAIJ"
1250 int MatGetSize_MPIBAIJ(Mat matin,int *m,int *n)
1251 {
1252   Mat_MPIBAIJ *mat = (Mat_MPIBAIJ *) matin->data;
1253 
1254   PetscFunctionBegin;
1255   if (m) *m = mat->M;
1256   if (n) *n = mat->N;
1257   PetscFunctionReturn(0);
1258 }
1259 
1260 #undef __FUNC__
1261 #define __FUNC__ "MatGetLocalSize_MPIBAIJ"
1262 int MatGetLocalSize_MPIBAIJ(Mat matin,int *m,int *n)
1263 {
1264   Mat_MPIBAIJ *mat = (Mat_MPIBAIJ *) matin->data;
1265 
1266   PetscFunctionBegin;
1267   *m = mat->m; *n = mat->N;
1268   PetscFunctionReturn(0);
1269 }
1270 
1271 #undef __FUNC__
1272 #define __FUNC__ "MatGetOwnershipRange_MPIBAIJ"
1273 int MatGetOwnershipRange_MPIBAIJ(Mat matin,int *m,int *n)
1274 {
1275   Mat_MPIBAIJ *mat = (Mat_MPIBAIJ *) matin->data;
1276 
1277   PetscFunctionBegin;
1278   *m = mat->rstart*mat->bs; *n = mat->rend*mat->bs;
1279   PetscFunctionReturn(0);
1280 }
1281 
1282 extern int MatGetRow_SeqBAIJ(Mat,int,int*,int**,Scalar**);
1283 extern int MatRestoreRow_SeqBAIJ(Mat,int,int*,int**,Scalar**);
1284 
1285 #undef __FUNC__
1286 #define __FUNC__ "MatGetRow_MPIBAIJ"
1287 int MatGetRow_MPIBAIJ(Mat matin,int row,int *nz,int **idx,Scalar **v)
1288 {
1289   Mat_MPIBAIJ *mat = (Mat_MPIBAIJ *) matin->data;
1290   Scalar     *vworkA, *vworkB, **pvA, **pvB,*v_p;
1291   int        bs = mat->bs, bs2 = mat->bs2, i, ierr, *cworkA, *cworkB, **pcA, **pcB;
1292   int        nztot, nzA, nzB, lrow, brstart = mat->rstart*bs, brend = mat->rend*bs;
1293   int        *cmap, *idx_p,cstart = mat->cstart;
1294 
1295   PetscFunctionBegin;
1296   if (mat->getrowactive == PETSC_TRUE) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,0,"Already active");
1297   mat->getrowactive = PETSC_TRUE;
1298 
1299   if (!mat->rowvalues && (idx || v)) {
1300     /*
1301         allocate enough space to hold information from the longest row.
1302     */
1303     Mat_SeqBAIJ *Aa = (Mat_SeqBAIJ *) mat->A->data,*Ba = (Mat_SeqBAIJ *) mat->B->data;
1304     int     max = 1,mbs = mat->mbs,tmp;
1305     for ( i=0; i<mbs; i++ ) {
1306       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1307       if (max < tmp) { max = tmp; }
1308     }
1309     mat->rowvalues = (Scalar *) PetscMalloc( max*bs2*(sizeof(int)+sizeof(Scalar)));
1310     CHKPTRQ(mat->rowvalues);
1311     mat->rowindices = (int *) (mat->rowvalues + max*bs2);
1312   }
1313 
1314   if (row < brstart || row >= brend) SETERRQ(PETSC_ERR_SUP,0,"Only local rows")
1315   lrow = row - brstart;
1316 
1317   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1318   if (!v)   {pvA = 0; pvB = 0;}
1319   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1320   ierr = (*mat->A->ops.getrow)(mat->A,lrow,&nzA,pcA,pvA); CHKERRQ(ierr);
1321   ierr = (*mat->B->ops.getrow)(mat->B,lrow,&nzB,pcB,pvB); CHKERRQ(ierr);
1322   nztot = nzA + nzB;
1323 
1324   cmap  = mat->garray;
1325   if (v  || idx) {
1326     if (nztot) {
1327       /* Sort by increasing column numbers, assuming A and B already sorted */
1328       int imark = -1;
1329       if (v) {
1330         *v = v_p = mat->rowvalues;
1331         for ( i=0; i<nzB; i++ ) {
1332           if (cmap[cworkB[i]/bs] < cstart)   v_p[i] = vworkB[i];
1333           else break;
1334         }
1335         imark = i;
1336         for ( i=0; i<nzA; i++ )     v_p[imark+i] = vworkA[i];
1337         for ( i=imark; i<nzB; i++ ) v_p[nzA+i]   = vworkB[i];
1338       }
1339       if (idx) {
1340         *idx = idx_p = mat->rowindices;
1341         if (imark > -1) {
1342           for ( i=0; i<imark; i++ ) {
1343             idx_p[i] = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs;
1344           }
1345         } else {
1346           for ( i=0; i<nzB; i++ ) {
1347             if (cmap[cworkB[i]/bs] < cstart)
1348               idx_p[i] = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs ;
1349             else break;
1350           }
1351           imark = i;
1352         }
1353         for ( i=0; i<nzA; i++ )     idx_p[imark+i] = cstart*bs + cworkA[i];
1354         for ( i=imark; i<nzB; i++ ) idx_p[nzA+i]   = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs ;
1355       }
1356     } else {
1357       if (idx) *idx = 0;
1358       if (v)   *v   = 0;
1359     }
1360   }
1361   *nz = nztot;
1362   ierr = (*mat->A->ops.restorerow)(mat->A,lrow,&nzA,pcA,pvA); CHKERRQ(ierr);
1363   ierr = (*mat->B->ops.restorerow)(mat->B,lrow,&nzB,pcB,pvB); CHKERRQ(ierr);
1364   PetscFunctionReturn(0);
1365 }
1366 
1367 #undef __FUNC__
1368 #define __FUNC__ "MatRestoreRow_MPIBAIJ"
1369 int MatRestoreRow_MPIBAIJ(Mat mat,int row,int *nz,int **idx,Scalar **v)
1370 {
1371   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
1372 
1373   PetscFunctionBegin;
1374   if (baij->getrowactive == PETSC_FALSE) {
1375     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,0,"MatGetRow not called");
1376   }
1377   baij->getrowactive = PETSC_FALSE;
1378   PetscFunctionReturn(0);
1379 }
1380 
1381 #undef __FUNC__
1382 #define __FUNC__ "MatGetBlockSize_MPIBAIJ"
1383 int MatGetBlockSize_MPIBAIJ(Mat mat,int *bs)
1384 {
1385   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) mat->data;
1386 
1387   PetscFunctionBegin;
1388   *bs = baij->bs;
1389   PetscFunctionReturn(0);
1390 }
1391 
1392 #undef __FUNC__
1393 #define __FUNC__ "MatZeroEntries_MPIBAIJ"
1394 int MatZeroEntries_MPIBAIJ(Mat A)
1395 {
1396   Mat_MPIBAIJ *l = (Mat_MPIBAIJ *) A->data;
1397   int         ierr;
1398 
1399   PetscFunctionBegin;
1400   ierr = MatZeroEntries(l->A); CHKERRQ(ierr);
1401   ierr = MatZeroEntries(l->B); CHKERRQ(ierr);
1402   PetscFunctionReturn(0);
1403 }
1404 
1405 #undef __FUNC__
1406 #define __FUNC__ "MatGetInfo_MPIBAIJ"
1407 int MatGetInfo_MPIBAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1408 {
1409   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) matin->data;
1410   Mat         A = a->A, B = a->B;
1411   int         ierr;
1412   double      isend[5], irecv[5];
1413 
1414   PetscFunctionBegin;
1415   info->block_size     = (double)a->bs;
1416   ierr = MatGetInfo(A,MAT_LOCAL,info); CHKERRQ(ierr);
1417   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->memory;
1418   ierr = MatGetInfo(B,MAT_LOCAL,info); CHKERRQ(ierr);
1419   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->memory;
1420   if (flag == MAT_LOCAL) {
1421     info->nz_used      = isend[0];
1422     info->nz_allocated = isend[1];
1423     info->nz_unneeded  = isend[2];
1424     info->memory       = isend[3];
1425     info->mallocs      = isend[4];
1426   } else if (flag == MAT_GLOBAL_MAX) {
1427     ierr = MPI_Allreduce(isend,irecv,5,MPI_INT,MPI_MAX,matin->comm);CHKERRQ(ierr);
1428     info->nz_used      = irecv[0];
1429     info->nz_allocated = irecv[1];
1430     info->nz_unneeded  = irecv[2];
1431     info->memory       = irecv[3];
1432     info->mallocs      = irecv[4];
1433   } else if (flag == MAT_GLOBAL_SUM) {
1434     ierr = MPI_Allreduce(isend,irecv,5,MPI_INT,MPI_SUM,matin->comm);CHKERRQ(ierr);
1435     info->nz_used      = irecv[0];
1436     info->nz_allocated = irecv[1];
1437     info->nz_unneeded  = irecv[2];
1438     info->memory       = irecv[3];
1439     info->mallocs      = irecv[4];
1440   }
1441   info->rows_global       = (double)a->M;
1442   info->columns_global    = (double)a->N;
1443   info->rows_local        = (double)a->m;
1444   info->columns_local     = (double)a->N;
1445   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1446   info->fill_ratio_needed = 0;
1447   info->factor_mallocs    = 0;
1448   PetscFunctionReturn(0);
1449 }
1450 
1451 #undef __FUNC__
1452 #define __FUNC__ "MatSetOption_MPIBAIJ"
1453 int MatSetOption_MPIBAIJ(Mat A,MatOption op)
1454 {
1455   Mat_MPIBAIJ *a = (Mat_MPIBAIJ *) A->data;
1456 
1457   PetscFunctionBegin;
1458   if (op == MAT_NO_NEW_NONZERO_LOCATIONS ||
1459       op == MAT_YES_NEW_NONZERO_LOCATIONS ||
1460       op == MAT_COLUMNS_UNSORTED ||
1461       op == MAT_COLUMNS_SORTED ||
1462       op == MAT_NEW_NONZERO_ALLOCATION_ERROR ||
1463       op == MAT_NEW_NONZERO_LOCATION_ERROR) {
1464         MatSetOption(a->A,op);
1465         MatSetOption(a->B,op);
1466   } else if (op == MAT_ROW_ORIENTED) {
1467         a->roworiented = 1;
1468         MatSetOption(a->A,op);
1469         MatSetOption(a->B,op);
1470   } else if (op == MAT_ROWS_SORTED ||
1471              op == MAT_ROWS_UNSORTED ||
1472              op == MAT_SYMMETRIC ||
1473              op == MAT_STRUCTURALLY_SYMMETRIC ||
1474              op == MAT_YES_NEW_DIAGONALS)
1475     PLogInfo(A,"Info:MatSetOption_MPIBAIJ:Option ignored\n");
1476   else if (op == MAT_COLUMN_ORIENTED) {
1477     a->roworiented = 0;
1478     MatSetOption(a->A,op);
1479     MatSetOption(a->B,op);
1480   } else if (op == MAT_IGNORE_OFF_PROC_ENTRIES) {
1481     a->donotstash = 1;
1482   } else if (op == MAT_NO_NEW_DIAGONALS) {
1483     SETERRQ(PETSC_ERR_SUP,0,"MAT_NO_NEW_DIAGONALS");
1484   } else if (op == MAT_USE_HASH_TABLE) {
1485     a->ht_flag = 1;
1486   } else {
1487     SETERRQ(PETSC_ERR_SUP,0,"unknown option");
1488   }
1489   PetscFunctionReturn(0);
1490 }
1491 
1492 #undef __FUNC__
1493 #define __FUNC__ "MatTranspose_MPIBAIJ("
1494 int MatTranspose_MPIBAIJ(Mat A,Mat *matout)
1495 {
1496   Mat_MPIBAIJ *baij = (Mat_MPIBAIJ *) A->data;
1497   Mat_SeqBAIJ *Aloc;
1498   Mat        B;
1499   int        ierr,M=baij->M,N=baij->N,*ai,*aj,row,i,*rvals,j,k,col;
1500   int        bs=baij->bs,mbs=baij->mbs;
1501   Scalar     *a;
1502 
1503   PetscFunctionBegin;
1504   if (matout == PETSC_NULL && M != N) SETERRQ(PETSC_ERR_ARG_SIZ,0,"Square matrix only for in-place");
1505   ierr = MatCreateMPIBAIJ(A->comm,baij->bs,PETSC_DECIDE,PETSC_DECIDE,N,M,0,PETSC_NULL,0,PETSC_NULL,&B);
1506   CHKERRQ(ierr);
1507 
1508   /* copy over the A part */
1509   Aloc = (Mat_SeqBAIJ*) baij->A->data;
1510   ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1511   row = baij->rstart;
1512   rvals = (int *) PetscMalloc(bs*sizeof(int)); CHKPTRQ(rvals);
1513 
1514   for ( i=0; i<mbs; i++ ) {
1515     rvals[0] = bs*(baij->rstart + i);
1516     for ( j=1; j<bs; j++ ) { rvals[j] = rvals[j-1] + 1; }
1517     for ( j=ai[i]; j<ai[i+1]; j++ ) {
1518       col = (baij->cstart+aj[j])*bs;
1519       for (k=0; k<bs; k++ ) {
1520         ierr = MatSetValues(B,1,&col,bs,rvals,a,INSERT_VALUES);CHKERRQ(ierr);
1521         col++; a += bs;
1522       }
1523     }
1524   }
1525   /* copy over the B part */
1526   Aloc = (Mat_SeqBAIJ*) baij->B->data;
1527   ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1528   row = baij->rstart*bs;
1529   for ( i=0; i<mbs; i++ ) {
1530     rvals[0] = bs*(baij->rstart + i);
1531     for ( j=1; j<bs; j++ ) { rvals[j] = rvals[j-1] + 1; }
1532     for ( j=ai[i]; j<ai[i+1]; j++ ) {
1533       col = baij->garray[aj[j]]*bs;
1534       for (k=0; k<bs; k++ ) {
1535         ierr = MatSetValues(B,1,&col,bs,rvals,a,INSERT_VALUES);CHKERRQ(ierr);
1536         col++; a += bs;
1537       }
1538     }
1539   }
1540   PetscFree(rvals);
1541   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1542   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1543 
1544   if (matout != PETSC_NULL) {
1545     *matout = B;
1546   } else {
1547     /* This isn't really an in-place transpose .... but free data structures from baij */
1548     PetscFree(baij->rowners);
1549     ierr = MatDestroy(baij->A); CHKERRQ(ierr);
1550     ierr = MatDestroy(baij->B); CHKERRQ(ierr);
1551     if (baij->colmap) PetscFree(baij->colmap);
1552     if (baij->garray) PetscFree(baij->garray);
1553     if (baij->lvec) VecDestroy(baij->lvec);
1554     if (baij->Mvctx) VecScatterDestroy(baij->Mvctx);
1555     PetscFree(baij);
1556     PetscMemcpy(A,B,sizeof(struct _p_Mat));
1557     PetscHeaderDestroy(B);
1558   }
1559   PetscFunctionReturn(0);
1560 }
1561 
1562 #undef __FUNC__
1563 #define __FUNC__ "MatDiagonalScale_MPIBAIJ"
1564 int MatDiagonalScale_MPIBAIJ(Mat A,Vec ll,Vec rr)
1565 {
1566   Mat a = ((Mat_MPIBAIJ *) A->data)->A;
1567   Mat b = ((Mat_MPIBAIJ *) A->data)->B;
1568   int ierr,s1,s2,s3;
1569 
1570   PetscFunctionBegin;
1571   if (ll)  {
1572     ierr = VecGetLocalSize(ll,&s1); CHKERRQ(ierr);
1573     ierr = MatGetLocalSize(A,&s2,&s3); CHKERRQ(ierr);
1574     if (s1!=s2) SETERRQ(PETSC_ERR_ARG_SIZ,0,"non-conforming local sizes");
1575     ierr = MatDiagonalScale(a,ll,0); CHKERRQ(ierr);
1576     ierr = MatDiagonalScale(b,ll,0); CHKERRQ(ierr);
1577   }
1578   if (rr) SETERRQ(PETSC_ERR_SUP,0,"not supported for right vector");
1579   PetscFunctionReturn(0);
1580 }
1581 
1582 #undef __FUNC__
1583 #define __FUNC__ "MatZeroRows_MPIBAIJ"
1584 int MatZeroRows_MPIBAIJ(Mat A,IS is,Scalar *diag)
1585 {
1586   Mat_MPIBAIJ    *l = (Mat_MPIBAIJ *) A->data;
1587   int            i,ierr,N, *rows,*owners = l->rowners,size = l->size;
1588   int            *procs,*nprocs,j,found,idx,nsends,*work,row;
1589   int            nmax,*svalues,*starts,*owner,nrecvs,rank = l->rank;
1590   int            *rvalues,tag = A->tag,count,base,slen,n,*source;
1591   int            *lens,imdex,*lrows,*values,bs=l->bs,rstart_bs=l->rstart_bs;
1592   MPI_Comm       comm = A->comm;
1593   MPI_Request    *send_waits,*recv_waits;
1594   MPI_Status     recv_status,*send_status;
1595   IS             istmp;
1596 
1597   PetscFunctionBegin;
1598   ierr = ISGetSize(is,&N); CHKERRQ(ierr);
1599   ierr = ISGetIndices(is,&rows); CHKERRQ(ierr);
1600 
1601   /*  first count number of contributors to each processor */
1602   nprocs = (int *) PetscMalloc( 2*size*sizeof(int) ); CHKPTRQ(nprocs);
1603   PetscMemzero(nprocs,2*size*sizeof(int)); procs = nprocs + size;
1604   owner = (int *) PetscMalloc((N+1)*sizeof(int)); CHKPTRQ(owner); /* see note*/
1605   for ( i=0; i<N; i++ ) {
1606     idx = rows[i];
1607     found = 0;
1608     for ( j=0; j<size; j++ ) {
1609       if (idx >= owners[j]*bs && idx < owners[j+1]*bs) {
1610         nprocs[j]++; procs[j] = 1; owner[i] = j; found = 1; break;
1611       }
1612     }
1613     if (!found) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Index out of range");
1614   }
1615   nsends = 0;  for ( i=0; i<size; i++ ) { nsends += procs[i];}
1616 
1617   /* inform other processors of number of messages and max length*/
1618   work   = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(work);
1619   ierr   = MPI_Allreduce( procs, work,size,MPI_INT,MPI_SUM,comm);CHKERRQ(ierr);
1620   nrecvs = work[rank];
1621   ierr   = MPI_Allreduce( nprocs, work,size,MPI_INT,MPI_MAX,comm);CHKERRQ(ierr);
1622   nmax   = work[rank];
1623   PetscFree(work);
1624 
1625   /* post receives:   */
1626   rvalues = (int *) PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(int)); CHKPTRQ(rvalues);
1627   recv_waits = (MPI_Request *) PetscMalloc((nrecvs+1)*sizeof(MPI_Request));CHKPTRQ(recv_waits);
1628   for ( i=0; i<nrecvs; i++ ) {
1629     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPI_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
1630   }
1631 
1632   /* do sends:
1633      1) starts[i] gives the starting index in svalues for stuff going to
1634      the ith processor
1635   */
1636   svalues = (int *) PetscMalloc( (N+1)*sizeof(int) ); CHKPTRQ(svalues);
1637   send_waits = (MPI_Request *) PetscMalloc( (nsends+1)*sizeof(MPI_Request));CHKPTRQ(send_waits);
1638   starts = (int *) PetscMalloc( (size+1)*sizeof(int) ); CHKPTRQ(starts);
1639   starts[0] = 0;
1640   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
1641   for ( i=0; i<N; i++ ) {
1642     svalues[starts[owner[i]]++] = rows[i];
1643   }
1644   ISRestoreIndices(is,&rows);
1645 
1646   starts[0] = 0;
1647   for ( i=1; i<size+1; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
1648   count = 0;
1649   for ( i=0; i<size; i++ ) {
1650     if (procs[i]) {
1651       ierr = MPI_Isend(svalues+starts[i],nprocs[i],MPI_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
1652     }
1653   }
1654   PetscFree(starts);
1655 
1656   base = owners[rank]*bs;
1657 
1658   /*  wait on receives */
1659   lens   = (int *) PetscMalloc( 2*(nrecvs+1)*sizeof(int) ); CHKPTRQ(lens);
1660   source = lens + nrecvs;
1661   count  = nrecvs; slen = 0;
1662   while (count) {
1663     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
1664     /* unpack receives into our local space */
1665     ierr = MPI_Get_count(&recv_status,MPI_INT,&n);CHKERRQ(ierr);
1666     source[imdex]  = recv_status.MPI_SOURCE;
1667     lens[imdex]  = n;
1668     slen += n;
1669     count--;
1670   }
1671   PetscFree(recv_waits);
1672 
1673   /* move the data into the send scatter */
1674   lrows = (int *) PetscMalloc( (slen+1)*sizeof(int) ); CHKPTRQ(lrows);
1675   count = 0;
1676   for ( i=0; i<nrecvs; i++ ) {
1677     values = rvalues + i*nmax;
1678     for ( j=0; j<lens[i]; j++ ) {
1679       lrows[count++] = values[j] - base;
1680     }
1681   }
1682   PetscFree(rvalues); PetscFree(lens);
1683   PetscFree(owner); PetscFree(nprocs);
1684 
1685   /* actually zap the local rows */
1686   ierr = ISCreateGeneral(PETSC_COMM_SELF,slen,lrows,&istmp);CHKERRQ(ierr);
1687   PLogObjectParent(A,istmp);
1688 
1689   ierr = MatZeroRows(l->A,istmp,0); CHKERRQ(ierr);
1690   ierr = MatZeroRows(l->B,istmp,0); CHKERRQ(ierr);
1691   ierr = ISDestroy(istmp); CHKERRQ(ierr);
1692 
1693   if (diag) {
1694     for ( i = 0; i < slen; i++ ) {
1695       row = lrows[i] + rstart_bs;
1696       ierr = MatSetValues(A,1,&row,1,&row,diag,INSERT_VALUES); CHKERRQ(ierr);
1697     }
1698     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1699     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
1700   }
1701   PetscFree(lrows);
1702 
1703   /* wait on sends */
1704   if (nsends) {
1705     send_status = (MPI_Status *) PetscMalloc(nsends*sizeof(MPI_Status));CHKPTRQ(send_status);
1706     ierr        = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
1707     PetscFree(send_status);
1708   }
1709   PetscFree(send_waits); PetscFree(svalues);
1710 
1711   PetscFunctionReturn(0);
1712 }
1713 extern int MatPrintHelp_SeqBAIJ(Mat);
1714 #undef __FUNC__
1715 #define __FUNC__ "MatPrintHelp_MPIBAIJ"
1716 int MatPrintHelp_MPIBAIJ(Mat A)
1717 {
1718   Mat_MPIBAIJ *a   = (Mat_MPIBAIJ*) A->data;
1719   MPI_Comm    comm = A->comm;
1720   static int  called = 0;
1721   int         ierr;
1722 
1723   PetscFunctionBegin;
1724   if (!a->rank) {
1725     ierr = MatPrintHelp_SeqBAIJ(a->A);CHKERRQ(ierr);
1726   }
1727   if (called) {PetscFunctionReturn(0);} else called = 1;
1728   (*PetscHelpPrintf)(comm," Options for MATMPIBAIJ matrix format (the defaults):\n");
1729   (*PetscHelpPrintf)(comm,"  -mat_use_hash_table <factor>: Use hashtable for efficient matrix assembly\n");
1730   PetscFunctionReturn(0);
1731 }
1732 
1733 #undef __FUNC__
1734 #define __FUNC__ "MatSetUnfactored_MPIBAIJ"
1735 int MatSetUnfactored_MPIBAIJ(Mat A)
1736 {
1737   Mat_MPIBAIJ *a   = (Mat_MPIBAIJ*) A->data;
1738   int         ierr;
1739 
1740   PetscFunctionBegin;
1741   ierr = MatSetUnfactored(a->A); CHKERRQ(ierr);
1742   PetscFunctionReturn(0);
1743 }
1744 
1745 static int MatConvertSameType_MPIBAIJ(Mat,Mat *,int);
1746 
1747 /* -------------------------------------------------------------------*/
1748 static struct _MatOps MatOps = {
1749   MatSetValues_MPIBAIJ,MatGetRow_MPIBAIJ,MatRestoreRow_MPIBAIJ,MatMult_MPIBAIJ,
1750   MatMultAdd_MPIBAIJ,MatMultTrans_MPIBAIJ,MatMultTransAdd_MPIBAIJ,0,
1751   0,0,0,0,
1752   0,0,MatTranspose_MPIBAIJ,MatGetInfo_MPIBAIJ,
1753   0,MatGetDiagonal_MPIBAIJ,MatDiagonalScale_MPIBAIJ,MatNorm_MPIBAIJ,
1754   MatAssemblyBegin_MPIBAIJ,MatAssemblyEnd_MPIBAIJ,0,MatSetOption_MPIBAIJ,
1755   MatZeroEntries_MPIBAIJ,MatZeroRows_MPIBAIJ,0,
1756   0,0,0,MatGetSize_MPIBAIJ,
1757   MatGetLocalSize_MPIBAIJ,MatGetOwnershipRange_MPIBAIJ,0,0,
1758   0,0,MatConvertSameType_MPIBAIJ,0,0,
1759   0,0,0,MatGetSubMatrices_MPIBAIJ,
1760   MatIncreaseOverlap_MPIBAIJ,MatGetValues_MPIBAIJ,0,MatPrintHelp_MPIBAIJ,
1761   MatScale_MPIBAIJ,0,0,0,MatGetBlockSize_MPIBAIJ,
1762   0,0,0,0,0,0,MatSetUnfactored_MPIBAIJ,0,MatSetValuesBlocked_MPIBAIJ};
1763 
1764 
1765 #undef __FUNC__
1766 #define __FUNC__ "MatCreateMPIBAIJ"
1767 /*@C
1768    MatCreateMPIBAIJ - Creates a sparse parallel matrix in block AIJ format
1769    (block compressed row).  For good matrix assembly performance
1770    the user should preallocate the matrix storage by setting the parameters
1771    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
1772    performance can be increased by more than a factor of 50.
1773 
1774    Input Parameters:
1775 .  comm - MPI communicator
1776 .  bs   - size of blockk
1777 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
1778            This value should be the same as the local size used in creating the
1779            y vector for the matrix-vector product y = Ax.
1780 .  n - number of local columns (or PETSC_DECIDE to have calculated if N is given)
1781            This value should be the same as the local size used in creating the
1782            x vector for the matrix-vector product y = Ax.
1783 .  M - number of global rows (or PETSC_DECIDE to have calculated if m is given)
1784 .  N - number of global columns (or PETSC_DECIDE to have calculated if n is given)
1785 .  d_nz  - number of block nonzeros per block row in diagonal portion of local
1786            submatrix  (same for all local rows)
1787 .  d_nzz - array containing the number of block nonzeros in the various block rows
1788            of the in diagonal portion of the local (possibly different for each block
1789            row) or PETSC_NULL.  You must leave room for the diagonal entry even if
1790            it is zero.
1791 .  o_nz  - number of block nonzeros per block row in the off-diagonal portion of local
1792            submatrix (same for all local rows).
1793 .  o_nzz - array containing the number of nonzeros in the various block rows of the
1794            off-diagonal portion of the local submatrix (possibly different for
1795            each block row) or PETSC_NULL.
1796 
1797    Output Parameter:
1798 .  A - the matrix
1799 
1800    Notes:
1801    The user MUST specify either the local or global matrix dimensions
1802    (possibly both).
1803 
1804    Storage Information:
1805    For a square global matrix we define each processor's diagonal portion
1806    to be its local rows and the corresponding columns (a square submatrix);
1807    each processor's off-diagonal portion encompasses the remainder of the
1808    local matrix (a rectangular submatrix).
1809 
1810    The user can specify preallocated storage for the diagonal part of
1811    the local submatrix with either d_nz or d_nnz (not both).  Set
1812    d_nz=PETSC_DEFAULT and d_nnz=PETSC_NULL for PETSc to control dynamic
1813    memory allocation.  Likewise, specify preallocated storage for the
1814    off-diagonal part of the local submatrix with o_nz or o_nnz (not both).
1815 
1816    Consider a processor that owns rows 3, 4 and 5 of a parallel matrix. In
1817    the figure below we depict these three local rows and all columns (0-11).
1818 
1819 $          0 1 2 3 4 5 6 7 8 9 10 11
1820 $         -------------------
1821 $  row 3  |  o o o d d d o o o o o o
1822 $  row 4  |  o o o d d d o o o o o o
1823 $  row 5  |  o o o d d d o o o o o o
1824 $         -------------------
1825 $
1826 
1827    Thus, any entries in the d locations are stored in the d (diagonal)
1828    submatrix, and any entries in the o locations are stored in the
1829    o (off-diagonal) submatrix.  Note that the d and the o submatrices are
1830    stored simply in the MATSEQBAIJ format for compressed row storage.
1831 
1832    Now d_nz should indicate the number of block nonzeros per row in the d matrix,
1833    and o_nz should indicate the number of block nonzeros per row in the o matrix.
1834    In general, for PDE problems in which most nonzeros are near the diagonal,
1835    one expects d_nz >> o_nz.   For large problems you MUST preallocate memory
1836    or you will get TERRIBLE performance; see the users' manual chapter on
1837    matrices.
1838 
1839 .keywords: matrix, block, aij, compressed row, sparse, parallel
1840 
1841 .seealso: MatCreate(), MatCreateSeqBAIJ(), MatSetValues()
1842 @*/
1843 int MatCreateMPIBAIJ(MPI_Comm comm,int bs,int m,int n,int M,int N,
1844                     int d_nz,int *d_nnz,int o_nz,int *o_nnz,Mat *A)
1845 {
1846   Mat          B;
1847   Mat_MPIBAIJ  *b;
1848   int          ierr, i,sum[2],work[2],mbs,nbs,Mbs=PETSC_DECIDE,Nbs=PETSC_DECIDE,size,flg;
1849 
1850   PetscFunctionBegin;
1851   if (bs < 1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Invalid block size specified, must be positive");
1852 
1853   MPI_Comm_size(comm,&size);
1854   if (size == 1) {
1855     if (M == PETSC_DECIDE) M = m;
1856     if (N == PETSC_DECIDE) N = n;
1857     ierr = MatCreateSeqBAIJ(comm,bs,M,N,d_nz,d_nnz,A); CHKERRQ(ierr);
1858     PetscFunctionReturn(0);
1859   }
1860 
1861   *A = 0;
1862   PetscHeaderCreate(B,_p_Mat,MAT_COOKIE,MATMPIBAIJ,comm,MatDestroy,MatView);
1863   PLogObjectCreate(B);
1864   B->data       = (void *) (b = PetscNew(Mat_MPIBAIJ)); CHKPTRQ(b);
1865   PetscMemzero(b,sizeof(Mat_MPIBAIJ));
1866   PetscMemcpy(&B->ops,&MatOps,sizeof(struct _MatOps));
1867 
1868   B->destroy    = MatDestroy_MPIBAIJ;
1869   B->view       = MatView_MPIBAIJ;
1870   B->mapping    = 0;
1871   B->factor     = 0;
1872   B->assembled  = PETSC_FALSE;
1873 
1874   B->insertmode = NOT_SET_VALUES;
1875   MPI_Comm_rank(comm,&b->rank);
1876   MPI_Comm_size(comm,&b->size);
1877 
1878   if ( m == PETSC_DECIDE && (d_nnz != PETSC_NULL || o_nnz != PETSC_NULL)) {
1879     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"Cannot have PETSC_DECIDE rows but set d_nnz or o_nnz");
1880   }
1881   if ( M == PETSC_DECIDE && m == PETSC_DECIDE) {
1882     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"either M or m should be specified");
1883   }
1884   if ( N == PETSC_DECIDE && n == PETSC_DECIDE) {
1885     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,0,"either N or n should be specified");
1886   }
1887   if ( M != PETSC_DECIDE && m != PETSC_DECIDE) M = PETSC_DECIDE;
1888   if ( N != PETSC_DECIDE && n != PETSC_DECIDE) N = PETSC_DECIDE;
1889 
1890   if (M == PETSC_DECIDE || N == PETSC_DECIDE) {
1891     work[0] = m; work[1] = n;
1892     mbs = m/bs; nbs = n/bs;
1893     ierr = MPI_Allreduce( work, sum,2,MPI_INT,MPI_SUM,comm );CHKERRQ(ierr);
1894     if (M == PETSC_DECIDE) {M = sum[0]; Mbs = M/bs;}
1895     if (N == PETSC_DECIDE) {N = sum[1]; Nbs = N/bs;}
1896   }
1897   if (m == PETSC_DECIDE) {
1898     Mbs = M/bs;
1899     if (Mbs*bs != M) SETERRQ(PETSC_ERR_ARG_SIZ,0,"No of global rows must be divisible by blocksize");
1900     mbs = Mbs/b->size + ((Mbs % b->size) > b->rank);
1901     m   = mbs*bs;
1902   }
1903   if (n == PETSC_DECIDE) {
1904     Nbs = N/bs;
1905     if (Nbs*bs != N) SETERRQ(PETSC_ERR_ARG_SIZ,0,"No of global cols must be divisible by blocksize");
1906     nbs = Nbs/b->size + ((Nbs % b->size) > b->rank);
1907     n   = nbs*bs;
1908   }
1909   if (mbs*bs != m || nbs*bs != n) {
1910     SETERRQ(PETSC_ERR_ARG_SIZ,0,"No of local rows, cols must be divisible by blocksize");
1911   }
1912 
1913   b->m = m; B->m = m;
1914   b->n = n; B->n = n;
1915   b->N = N; B->N = N;
1916   b->M = M; B->M = M;
1917   b->bs  = bs;
1918   b->bs2 = bs*bs;
1919   b->mbs = mbs;
1920   b->nbs = nbs;
1921   b->Mbs = Mbs;
1922   b->Nbs = Nbs;
1923 
1924   /* build local table of row and column ownerships */
1925   b->rowners = (int *) PetscMalloc(2*(b->size+2)*sizeof(int)); CHKPTRQ(b->rowners);
1926   PLogObjectMemory(B,2*(b->size+2)*sizeof(int)+sizeof(struct _p_Mat)+sizeof(Mat_MPIBAIJ));
1927   b->cowners = b->rowners + b->size + 2;
1928   ierr = MPI_Allgather(&mbs,1,MPI_INT,b->rowners+1,1,MPI_INT,comm);CHKERRQ(ierr);
1929   b->rowners[0] = 0;
1930   for ( i=2; i<=b->size; i++ ) {
1931     b->rowners[i] += b->rowners[i-1];
1932   }
1933   b->rstart    = b->rowners[b->rank];
1934   b->rend      = b->rowners[b->rank+1];
1935   b->rstart_bs = b->rstart * bs;
1936   b->rend_bs   = b->rend * bs;
1937 
1938   ierr = MPI_Allgather(&nbs,1,MPI_INT,b->cowners+1,1,MPI_INT,comm);CHKERRQ(ierr);
1939   b->cowners[0] = 0;
1940   for ( i=2; i<=b->size; i++ ) {
1941     b->cowners[i] += b->cowners[i-1];
1942   }
1943   b->cstart    = b->cowners[b->rank];
1944   b->cend      = b->cowners[b->rank+1];
1945   b->cstart_bs = b->cstart * bs;
1946   b->cend_bs   = b->cend * bs;
1947 
1948 
1949   if (d_nz == PETSC_DEFAULT) d_nz = 5;
1950   ierr = MatCreateSeqBAIJ(PETSC_COMM_SELF,bs,m,n,d_nz,d_nnz,&b->A); CHKERRQ(ierr);
1951   PLogObjectParent(B,b->A);
1952   if (o_nz == PETSC_DEFAULT) o_nz = 0;
1953   ierr = MatCreateSeqBAIJ(PETSC_COMM_SELF,bs,m,N,o_nz,o_nnz,&b->B); CHKERRQ(ierr);
1954   PLogObjectParent(B,b->B);
1955 
1956   /* build cache for off array entries formed */
1957   ierr = StashBuild_Private(&b->stash); CHKERRQ(ierr);
1958   b->donotstash  = 0;
1959   b->colmap      = 0;
1960   b->garray      = 0;
1961   b->roworiented = 1;
1962 
1963   /* stuff used in block assembly */
1964   b->barray       = 0;
1965 
1966   /* stuff used for matrix vector multiply */
1967   b->lvec         = 0;
1968   b->Mvctx        = 0;
1969 
1970   /* stuff for MatGetRow() */
1971   b->rowindices   = 0;
1972   b->rowvalues    = 0;
1973   b->getrowactive = PETSC_FALSE;
1974 
1975   /* hash table stuff */
1976   b->ht           = 0;
1977   b->hd           = 0;
1978   b->ht_size      = 0;
1979   b->ht_flag      = 0;
1980   b->ht_fact      = 0;
1981   b->ht_total_ct  = 0;
1982   b->ht_insert_ct = 0;
1983 
1984   *A = B;
1985   ierr = OptionsHasName(PETSC_NULL,"-mat_use_hash_table",&flg); CHKERRQ(ierr);
1986   if (flg) {
1987     double fact = 1.39;
1988     ierr = MatSetOption(B,MAT_USE_HASH_TABLE); CHKERRQ(ierr);
1989     ierr = OptionsGetDouble(PETSC_NULL,"-mat_use_hash_table",&fact,&flg); CHKERRQ(ierr);
1990     if (fact <= 1.0) fact = 1.39;
1991     ierr = MatMPIBAIJSetHashTableFactor(B,fact); CHKERRQ(ierr);
1992     PLogInfo(0,"MatCreateMPIBAIJ:Hash table Factor used %5.2f\n",fact);
1993   }
1994   PetscFunctionReturn(0);
1995 }
1996 
1997 #undef __FUNC__
1998 #define __FUNC__ "MatConvertSameType_MPIBAIJ"
1999 static int MatConvertSameType_MPIBAIJ(Mat matin,Mat *newmat,int cpvalues)
2000 {
2001   Mat         mat;
2002   Mat_MPIBAIJ *a,*oldmat = (Mat_MPIBAIJ *) matin->data;
2003   int         ierr, len=0, flg;
2004 
2005   PetscFunctionBegin;
2006   *newmat       = 0;
2007   PetscHeaderCreate(mat,_p_Mat,MAT_COOKIE,MATMPIBAIJ,matin->comm,MatDestroy,MatView);
2008   PLogObjectCreate(mat);
2009   mat->data       = (void *) (a = PetscNew(Mat_MPIBAIJ)); CHKPTRQ(a);
2010   PetscMemcpy(&mat->ops,&MatOps,sizeof(struct _MatOps));
2011   mat->destroy    = MatDestroy_MPIBAIJ;
2012   mat->view       = MatView_MPIBAIJ;
2013   mat->factor     = matin->factor;
2014   mat->assembled  = PETSC_TRUE;
2015 
2016   a->m = mat->m   = oldmat->m;
2017   a->n = mat->n   = oldmat->n;
2018   a->M = mat->M   = oldmat->M;
2019   a->N = mat->N   = oldmat->N;
2020 
2021   a->bs  = oldmat->bs;
2022   a->bs2 = oldmat->bs2;
2023   a->mbs = oldmat->mbs;
2024   a->nbs = oldmat->nbs;
2025   a->Mbs = oldmat->Mbs;
2026   a->Nbs = oldmat->Nbs;
2027 
2028   a->rstart       = oldmat->rstart;
2029   a->rend         = oldmat->rend;
2030   a->cstart       = oldmat->cstart;
2031   a->cend         = oldmat->cend;
2032   a->size         = oldmat->size;
2033   a->rank         = oldmat->rank;
2034   mat->insertmode = NOT_SET_VALUES;
2035   a->rowvalues    = 0;
2036   a->getrowactive = PETSC_FALSE;
2037   a->barray       = 0;
2038 
2039   /* hash table stuff */
2040   a->ht           = 0;
2041   a->hd           = 0;
2042   a->ht_size      = 0;
2043   a->ht_flag      = oldmat->ht_flag;
2044   a->ht_fact      = oldmat->ht_fact;
2045   a->ht_total_ct  = 0;
2046   a->ht_insert_ct = 0;
2047 
2048 
2049   a->rowners = (int *) PetscMalloc(2*(a->size+2)*sizeof(int)); CHKPTRQ(a->rowners);
2050   PLogObjectMemory(mat,2*(a->size+2)*sizeof(int)+sizeof(struct _p_Mat)+sizeof(Mat_MPIBAIJ));
2051   a->cowners = a->rowners + a->size + 2;
2052   PetscMemcpy(a->rowners,oldmat->rowners,2*(a->size+2)*sizeof(int));
2053   ierr = StashInitialize_Private(&a->stash); CHKERRQ(ierr);
2054   if (oldmat->colmap) {
2055     a->colmap = (int *) PetscMalloc((a->Nbs)*sizeof(int));CHKPTRQ(a->colmap);
2056     PLogObjectMemory(mat,(a->Nbs)*sizeof(int));
2057     PetscMemcpy(a->colmap,oldmat->colmap,(a->Nbs)*sizeof(int));
2058   } else a->colmap = 0;
2059   if (oldmat->garray && (len = ((Mat_SeqBAIJ *) (oldmat->B->data))->nbs)) {
2060     a->garray = (int *) PetscMalloc(len*sizeof(int)); CHKPTRQ(a->garray);
2061     PLogObjectMemory(mat,len*sizeof(int));
2062     PetscMemcpy(a->garray,oldmat->garray,len*sizeof(int));
2063   } else a->garray = 0;
2064 
2065   ierr =  VecDuplicate(oldmat->lvec,&a->lvec); CHKERRQ(ierr);
2066   PLogObjectParent(mat,a->lvec);
2067   ierr =  VecScatterCopy(oldmat->Mvctx,&a->Mvctx); CHKERRQ(ierr);
2068   PLogObjectParent(mat,a->Mvctx);
2069   ierr =  MatConvert(oldmat->A,MATSAME,&a->A); CHKERRQ(ierr);
2070   PLogObjectParent(mat,a->A);
2071   ierr =  MatConvert(oldmat->B,MATSAME,&a->B); CHKERRQ(ierr);
2072   PLogObjectParent(mat,a->B);
2073   ierr = OptionsHasName(PETSC_NULL,"-help",&flg); CHKERRQ(ierr);
2074   if (flg) {
2075     ierr = MatPrintHelp(mat); CHKERRQ(ierr);
2076   }
2077   *newmat = mat;
2078   PetscFunctionReturn(0);
2079 }
2080 
2081 #include "sys.h"
2082 
2083 #undef __FUNC__
2084 #define __FUNC__ "MatLoad_MPIBAIJ"
2085 int MatLoad_MPIBAIJ(Viewer viewer,MatType type,Mat *newmat)
2086 {
2087   Mat          A;
2088   int          i, nz, ierr, j,rstart, rend, fd;
2089   Scalar       *vals,*buf;
2090   MPI_Comm     comm = ((PetscObject)viewer)->comm;
2091   MPI_Status   status;
2092   int          header[4],rank,size,*rowlengths = 0,M,N,m,*rowners,*browners,maxnz,*cols;
2093   int          *locrowlens,*sndcounts = 0,*procsnz = 0, jj,*mycols,*ibuf;
2094   int          flg,tag = ((PetscObject)viewer)->tag,bs=1,bs2,Mbs,mbs,extra_rows;
2095   int          *dlens,*odlens,*mask,*masked1,*masked2,rowcount,odcount;
2096   int          dcount,kmax,k,nzcount,tmp;
2097 
2098   PetscFunctionBegin;
2099   ierr = OptionsGetInt(PETSC_NULL,"-matload_block_size",&bs,&flg);CHKERRQ(ierr);
2100   bs2  = bs*bs;
2101 
2102   MPI_Comm_size(comm,&size); MPI_Comm_rank(comm,&rank);
2103   if (!rank) {
2104     ierr = ViewerBinaryGetDescriptor(viewer,&fd); CHKERRQ(ierr);
2105     ierr = PetscBinaryRead(fd,(char *)header,4,PETSC_INT); CHKERRQ(ierr);
2106     if (header[0] != MAT_COOKIE) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,0,"not matrix object");
2107     if (header[3] < 0) {
2108       SETERRQ(PETSC_ERR_FILE_UNEXPECTED,1,"Matrix stored in special format, cannot load as MPIBAIJ");
2109     }
2110   }
2111 
2112   ierr = MPI_Bcast(header+1,3,MPI_INT,0,comm);CHKERRQ(ierr);
2113   M = header[1]; N = header[2];
2114 
2115   if (M != N) SETERRQ(PETSC_ERR_SUP,0,"Can only do square matrices");
2116 
2117   /*
2118      This code adds extra rows to make sure the number of rows is
2119      divisible by the blocksize
2120   */
2121   Mbs        = M/bs;
2122   extra_rows = bs - M + bs*(Mbs);
2123   if (extra_rows == bs) extra_rows = 0;
2124   else                  Mbs++;
2125   if (extra_rows &&!rank) {
2126     PLogInfo(0,"MatLoad_MPIBAIJ:Padding loaded matrix to match blocksize\n");
2127   }
2128 
2129   /* determine ownership of all rows */
2130   mbs = Mbs/size + ((Mbs % size) > rank);
2131   m   = mbs * bs;
2132   rowners = (int *) PetscMalloc(2*(size+2)*sizeof(int)); CHKPTRQ(rowners);
2133   browners = rowners + size + 1;
2134   ierr = MPI_Allgather(&mbs,1,MPI_INT,rowners+1,1,MPI_INT,comm);CHKERRQ(ierr);
2135   rowners[0] = 0;
2136   for ( i=2; i<=size; i++ ) rowners[i] += rowners[i-1];
2137   for ( i=0; i<=size;  i++ ) browners[i] = rowners[i]*bs;
2138   rstart = rowners[rank];
2139   rend   = rowners[rank+1];
2140 
2141   /* distribute row lengths to all processors */
2142   locrowlens = (int*) PetscMalloc( (rend-rstart)*bs*sizeof(int) ); CHKPTRQ(locrowlens);
2143   if (!rank) {
2144     rowlengths = (int*) PetscMalloc( (M+extra_rows)*sizeof(int) ); CHKPTRQ(rowlengths);
2145     ierr = PetscBinaryRead(fd,rowlengths,M,PETSC_INT); CHKERRQ(ierr);
2146     for ( i=0; i<extra_rows; i++ ) rowlengths[M+i] = 1;
2147     sndcounts = (int*) PetscMalloc( size*sizeof(int) ); CHKPTRQ(sndcounts);
2148     for ( i=0; i<size; i++ ) sndcounts[i] = browners[i+1] - browners[i];
2149     ierr = MPI_Scatterv(rowlengths,sndcounts,browners,MPI_INT,locrowlens,(rend-rstart)*bs,MPI_INT,0,comm);CHKERRQ(ierr);
2150     PetscFree(sndcounts);
2151   } else {
2152     ierr = MPI_Scatterv(0,0,0,MPI_INT,locrowlens,(rend-rstart)*bs,MPI_INT, 0,comm);CHKERRQ(ierr);
2153   }
2154 
2155   if (!rank) {
2156     /* calculate the number of nonzeros on each processor */
2157     procsnz = (int*) PetscMalloc( size*sizeof(int) ); CHKPTRQ(procsnz);
2158     PetscMemzero(procsnz,size*sizeof(int));
2159     for ( i=0; i<size; i++ ) {
2160       for ( j=rowners[i]*bs; j< rowners[i+1]*bs; j++ ) {
2161         procsnz[i] += rowlengths[j];
2162       }
2163     }
2164     PetscFree(rowlengths);
2165 
2166     /* determine max buffer needed and allocate it */
2167     maxnz = 0;
2168     for ( i=0; i<size; i++ ) {
2169       maxnz = PetscMax(maxnz,procsnz[i]);
2170     }
2171     cols = (int *) PetscMalloc( maxnz*sizeof(int) ); CHKPTRQ(cols);
2172 
2173     /* read in my part of the matrix column indices  */
2174     nz = procsnz[0];
2175     ibuf = (int *) PetscMalloc( nz*sizeof(int) ); CHKPTRQ(ibuf);
2176     mycols = ibuf;
2177     if (size == 1)  nz -= extra_rows;
2178     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT); CHKERRQ(ierr);
2179     if (size == 1)  for (i=0; i< extra_rows; i++) { mycols[nz+i] = M+i; }
2180 
2181     /* read in every ones (except the last) and ship off */
2182     for ( i=1; i<size-1; i++ ) {
2183       nz   = procsnz[i];
2184       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT); CHKERRQ(ierr);
2185       ierr = MPI_Send(cols,nz,MPI_INT,i,tag,comm);CHKERRQ(ierr);
2186     }
2187     /* read in the stuff for the last proc */
2188     if ( size != 1 ) {
2189       nz   = procsnz[size-1] - extra_rows;  /* the extra rows are not on the disk */
2190       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT); CHKERRQ(ierr);
2191       for ( i=0; i<extra_rows; i++ ) cols[nz+i] = M+i;
2192       ierr = MPI_Send(cols,nz+extra_rows,MPI_INT,size-1,tag,comm);CHKERRQ(ierr);
2193     }
2194     PetscFree(cols);
2195   } else {
2196     /* determine buffer space needed for message */
2197     nz = 0;
2198     for ( i=0; i<m; i++ ) {
2199       nz += locrowlens[i];
2200     }
2201     ibuf   = (int*) PetscMalloc( nz*sizeof(int) ); CHKPTRQ(ibuf);
2202     mycols = ibuf;
2203     /* receive message of column indices*/
2204     ierr = MPI_Recv(mycols,nz,MPI_INT,0,tag,comm,&status);CHKERRQ(ierr);
2205     ierr = MPI_Get_count(&status,MPI_INT,&maxnz);CHKERRQ(ierr);
2206     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,0,"something is wrong with file");
2207   }
2208 
2209   /* loop over local rows, determining number of off diagonal entries */
2210   dlens  = (int *) PetscMalloc( 2*(rend-rstart+1)*sizeof(int) ); CHKPTRQ(dlens);
2211   odlens = dlens + (rend-rstart);
2212   mask   = (int *) PetscMalloc( 3*Mbs*sizeof(int) ); CHKPTRQ(mask);
2213   PetscMemzero(mask,3*Mbs*sizeof(int));
2214   masked1 = mask    + Mbs;
2215   masked2 = masked1 + Mbs;
2216   rowcount = 0; nzcount = 0;
2217   for ( i=0; i<mbs; i++ ) {
2218     dcount  = 0;
2219     odcount = 0;
2220     for ( j=0; j<bs; j++ ) {
2221       kmax = locrowlens[rowcount];
2222       for ( k=0; k<kmax; k++ ) {
2223         tmp = mycols[nzcount++]/bs;
2224         if (!mask[tmp]) {
2225           mask[tmp] = 1;
2226           if (tmp < rstart || tmp >= rend ) masked2[odcount++] = tmp;
2227           else masked1[dcount++] = tmp;
2228         }
2229       }
2230       rowcount++;
2231     }
2232 
2233     dlens[i]  = dcount;
2234     odlens[i] = odcount;
2235 
2236     /* zero out the mask elements we set */
2237     for ( j=0; j<dcount; j++ ) mask[masked1[j]] = 0;
2238     for ( j=0; j<odcount; j++ ) mask[masked2[j]] = 0;
2239   }
2240 
2241   /* create our matrix */
2242   ierr = MatCreateMPIBAIJ(comm,bs,m,PETSC_DECIDE,M+extra_rows,N+extra_rows,0,dlens,0,odlens,newmat);
2243          CHKERRQ(ierr);
2244   A = *newmat;
2245   MatSetOption(A,MAT_COLUMNS_SORTED);
2246 
2247   if (!rank) {
2248     buf = (Scalar *) PetscMalloc( maxnz*sizeof(Scalar) ); CHKPTRQ(buf);
2249     /* read in my part of the matrix numerical values  */
2250     nz = procsnz[0];
2251     vals = buf;
2252     mycols = ibuf;
2253     if (size == 1)  nz -= extra_rows;
2254     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR); CHKERRQ(ierr);
2255     if (size == 1)  for (i=0; i< extra_rows; i++) { vals[nz+i] = 1.0; }
2256 
2257     /* insert into matrix */
2258     jj      = rstart*bs;
2259     for ( i=0; i<m; i++ ) {
2260       ierr = MatSetValues(A,1,&jj,locrowlens[i],mycols,vals,INSERT_VALUES);CHKERRQ(ierr);
2261       mycols += locrowlens[i];
2262       vals   += locrowlens[i];
2263       jj++;
2264     }
2265     /* read in other processors (except the last one) and ship out */
2266     for ( i=1; i<size-1; i++ ) {
2267       nz   = procsnz[i];
2268       vals = buf;
2269       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR); CHKERRQ(ierr);
2270       ierr = MPI_Send(vals,nz,MPIU_SCALAR,i,A->tag,comm);CHKERRQ(ierr);
2271     }
2272     /* the last proc */
2273     if ( size != 1 ){
2274       nz   = procsnz[i] - extra_rows;
2275       vals = buf;
2276       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR); CHKERRQ(ierr);
2277       for ( i=0; i<extra_rows; i++ ) vals[nz+i] = 1.0;
2278       ierr = MPI_Send(vals,nz+extra_rows,MPIU_SCALAR,size-1,A->tag,comm);CHKERRQ(ierr);
2279     }
2280     PetscFree(procsnz);
2281   } else {
2282     /* receive numeric values */
2283     buf = (Scalar*) PetscMalloc( nz*sizeof(Scalar) ); CHKPTRQ(buf);
2284 
2285     /* receive message of values*/
2286     vals   = buf;
2287     mycols = ibuf;
2288     ierr   = MPI_Recv(vals,nz,MPIU_SCALAR,0,A->tag,comm,&status);CHKERRQ(ierr);
2289     ierr   = MPI_Get_count(&status,MPIU_SCALAR,&maxnz);CHKERRQ(ierr);
2290     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,0,"something is wrong with file");
2291 
2292     /* insert into matrix */
2293     jj      = rstart*bs;
2294     for ( i=0; i<m; i++ ) {
2295       ierr    = MatSetValues(A,1,&jj,locrowlens[i],mycols,vals,INSERT_VALUES);CHKERRQ(ierr);
2296       mycols += locrowlens[i];
2297       vals   += locrowlens[i];
2298       jj++;
2299     }
2300   }
2301   PetscFree(locrowlens);
2302   PetscFree(buf);
2303   PetscFree(ibuf);
2304   PetscFree(rowners);
2305   PetscFree(dlens);
2306   PetscFree(mask);
2307   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
2308   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
2309   PetscFunctionReturn(0);
2310 }
2311 
2312 
2313 
2314 #undef __FUNC__
2315 #define __FUNC__ "MatMPIBAIJSetHashTableFactor"
2316 /*@
2317    MatMPIBAIJSetHashTableFactor - Sets the factor required to compute the size of the HashTable.
2318 
2319    Input Parameters:
2320 .  mat  - the matrix
2321 .  fact - factor
2322 
2323    Notes:
2324    This can also be set by the command line option: -mat_use_hash_table fact
2325 
2326 .keywords: matrix, hashtable, factor, HT
2327 
2328 .seealso: MatSetOption()
2329 @*/
2330 int MatMPIBAIJSetHashTableFactor(Mat mat,double fact)
2331 {
2332   int         ierr;
2333   Mat_MPIBAIJ *baij;
2334 
2335   PetscFunctionBegin;
2336   PetscValidHeaderSpecific(mat,MAT_COOKIE);
2337   if (mat->type != MATMPIBAIJ) {
2338       SETERRQ(PETSC_ERR_ARG_WRONG,1,"Incorrect matrix type. Use MPIBAIJ only.");
2339   }
2340   baij = (Mat_MPIBAIJ*) mat->data;
2341   baij->ht_fact = fact;
2342   PetscFunctionReturn(0);
2343 }
2344