xref: /petsc/src/mat/impls/sbaij/mpi/mpisbaij.c (revision d03495bd6a90c318a635ff2f45c05071e91761ec)
1 /*$Id: mpisbaij.c,v 1.54 2001/06/21 23:38:52 buschelm Exp buschelm $*/
2 
3 #include "src/mat/impls/baij/mpi/mpibaij.h"    /*I "petscmat.h" I*/
4 #include "src/vec/vecimpl.h"
5 #include "mpisbaij.h"
6 #include "src/mat/impls/sbaij/seq/sbaij.h"
7 
8 extern int MatSetUpMultiply_MPISBAIJ(Mat);
9 extern int DisAssemble_MPISBAIJ(Mat);
10 extern int MatIncreaseOverlap_MPISBAIJ(Mat,int,IS *,int);
11 extern int MatGetSubMatrices_MPISBAIJ(Mat,int,IS *,IS *,MatReuse,Mat **);
12 extern int MatGetValues_SeqSBAIJ(Mat,int,int *,int,int *,Scalar *);
13 extern int MatSetValues_SeqSBAIJ(Mat,int,int *,int,int *,Scalar *,InsertMode);
14 extern int MatSetValuesBlocked_SeqSBAIJ(Mat,int,int*,int,int*,Scalar*,InsertMode);
15 extern int MatGetRow_SeqSBAIJ(Mat,int,int*,int**,Scalar**);
16 extern int MatRestoreRow_SeqSBAIJ(Mat,int,int*,int**,Scalar**);
17 extern int MatPrintHelp_SeqSBAIJ(Mat);
18 extern int MatZeroRows_SeqSBAIJ(Mat,IS,Scalar*);
19 extern int MatZeroRows_SeqBAIJ(Mat,IS,Scalar *);
20 extern int MatGetRowMax_MPISBAIJ(Mat,Vec);
21 
22 /*  UGLY, ugly, ugly
23    When MatScalar == Scalar the function MatSetValuesBlocked_MPIBAIJ_MatScalar() does
24    not exist. Otherwise ..._MatScalar() takes matrix elements in single precision and
25    inserts them into the single precision data structure. The function MatSetValuesBlocked_MPIBAIJ()
26    converts the entries into single precision and then calls ..._MatScalar() to put them
27    into the single precision data structures.
28 */
29 #if defined(PETSC_USE_MAT_SINGLE)
30 extern int MatSetValuesBlocked_SeqSBAIJ_MatScalar(Mat,int,int*,int,int*,MatScalar*,InsertMode);
31 extern int MatSetValues_MPISBAIJ_MatScalar(Mat,int,int*,int,int*,MatScalar*,InsertMode);
32 extern int MatSetValuesBlocked_MPISBAIJ_MatScalar(Mat,int,int*,int,int*,MatScalar*,InsertMode);
33 extern int MatSetValues_MPISBAIJ_HT_MatScalar(Mat,int,int*,int,int*,MatScalar*,InsertMode);
34 extern int MatSetValuesBlocked_MPISBAIJ_HT_MatScalar(Mat,int,int*,int,int*,MatScalar*,InsertMode);
35 #else
36 #define MatSetValuesBlocked_SeqSBAIJ_MatScalar      MatSetValuesBlocked_SeqSBAIJ
37 #define MatSetValues_MPISBAIJ_MatScalar             MatSetValues_MPISBAIJ
38 #define MatSetValuesBlocked_MPISBAIJ_MatScalar      MatSetValuesBlocked_MPISBAIJ
39 #define MatSetValues_MPISBAIJ_HT_MatScalar          MatSetValues_MPISBAIJ_HT
40 #define MatSetValuesBlocked_MPISBAIJ_HT_MatScalar   MatSetValuesBlocked_MPISBAIJ_HT
41 #endif
42 
43 EXTERN_C_BEGIN
44 #undef __FUNCT__
45 #define __FUNCT__ "MatStoreValues_MPISBAIJ"
46 int MatStoreValues_MPISBAIJ(Mat mat)
47 {
48   Mat_MPISBAIJ *aij = (Mat_MPISBAIJ *)mat->data;
49   int          ierr;
50 
51   PetscFunctionBegin;
52   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
53   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
54   PetscFunctionReturn(0);
55 }
56 EXTERN_C_END
57 
58 EXTERN_C_BEGIN
59 #undef __FUNCT__
60 #define __FUNCT__ "MatRetrieveValues_MPISBAIJ"
61 int MatRetrieveValues_MPISBAIJ(Mat mat)
62 {
63   Mat_MPISBAIJ *aij = (Mat_MPISBAIJ *)mat->data;
64   int          ierr;
65 
66   PetscFunctionBegin;
67   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
68   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
69   PetscFunctionReturn(0);
70 }
71 EXTERN_C_END
72 
73 /*
74      Local utility routine that creates a mapping from the global column
75    number to the local number in the off-diagonal part of the local
76    storage of the matrix.  This is done in a non scable way since the
77    length of colmap equals the global matrix length.
78 */
79 #undef __FUNCT__
80 #define __FUNCT__ "CreateColmap_MPISBAIJ_Private"
81 static int CreateColmap_MPISBAIJ_Private(Mat mat)
82 {
83   PetscFunctionBegin;
84   SETERRQ(1,"Function not yet written for SBAIJ format");
85   /* PetscFunctionReturn(0); */
86 }
87 
88 #define CHUNKSIZE  10
89 
90 #define  MatSetValues_SeqSBAIJ_A_Private(row,col,value,addv) \
91 { \
92  \
93     brow = row/bs;  \
94     rp   = aj + ai[brow]; ap = aa + bs2*ai[brow]; \
95     rmax = aimax[brow]; nrow = ailen[brow]; \
96       bcol = col/bs; \
97       ridx = row % bs; cidx = col % bs; \
98       low = 0; high = nrow; \
99       while (high-low > 3) { \
100         t = (low+high)/2; \
101         if (rp[t] > bcol) high = t; \
102         else              low  = t; \
103       } \
104       for (_i=low; _i<high; _i++) { \
105         if (rp[_i] > bcol) break; \
106         if (rp[_i] == bcol) { \
107           bap  = ap +  bs2*_i + bs*cidx + ridx; \
108           if (addv == ADD_VALUES) *bap += value;  \
109           else                    *bap  = value;  \
110           goto a_noinsert; \
111         } \
112       } \
113       if (a->nonew == 1) goto a_noinsert; \
114       else if (a->nonew == -1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero into matrix"); \
115       if (nrow >= rmax) { \
116         /* there is no extra room in row, therefore enlarge */ \
117         int       new_nz = ai[a->mbs] + CHUNKSIZE,len,*new_i,*new_j; \
118         MatScalar *new_a; \
119  \
120         if (a->nonew == -2) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero in the matrix"); \
121  \
122         /* malloc new storage space */ \
123         len   = new_nz*(sizeof(int)+bs2*sizeof(MatScalar))+(a->mbs+1)*sizeof(int); \
124         ierr  = PetscMalloc(len,&new_a);CHKERRQ(ierr); \
125         new_j = (int*)(new_a + bs2*new_nz); \
126         new_i = new_j + new_nz; \
127  \
128         /* copy over old data into new slots */ \
129         for (ii=0; ii<brow+1; ii++) {new_i[ii] = ai[ii];} \
130         for (ii=brow+1; ii<a->mbs+1; ii++) {new_i[ii] = ai[ii]+CHUNKSIZE;} \
131         ierr = PetscMemcpy(new_j,aj,(ai[brow]+nrow)*sizeof(int));CHKERRQ(ierr); \
132         len = (new_nz - CHUNKSIZE - ai[brow] - nrow); \
133         ierr = PetscMemcpy(new_j+ai[brow]+nrow+CHUNKSIZE,aj+ai[brow]+nrow,len*sizeof(int));CHKERRQ(ierr); \
134         ierr = PetscMemcpy(new_a,aa,(ai[brow]+nrow)*bs2*sizeof(MatScalar));CHKERRQ(ierr); \
135         ierr = PetscMemzero(new_a+bs2*(ai[brow]+nrow),bs2*CHUNKSIZE*sizeof(Scalar));CHKERRQ(ierr); \
136         ierr = PetscMemcpy(new_a+bs2*(ai[brow]+nrow+CHUNKSIZE), \
137                     aa+bs2*(ai[brow]+nrow),bs2*len*sizeof(MatScalar));CHKERRQ(ierr);  \
138         /* free up old matrix storage */ \
139         ierr = PetscFree(a->a);CHKERRQ(ierr);  \
140         if (!a->singlemalloc) { \
141           ierr = PetscFree(a->i);CHKERRQ(ierr); \
142           ierr = PetscFree(a->j);CHKERRQ(ierr);\
143         } \
144         aa = a->a = new_a; ai = a->i = new_i; aj = a->j = new_j;  \
145         a->singlemalloc = PETSC_TRUE; \
146  \
147         rp   = aj + ai[brow]; ap = aa + bs2*ai[brow]; \
148         rmax = aimax[brow] = aimax[brow] + CHUNKSIZE; \
149         PetscLogObjectMemory(A,CHUNKSIZE*(sizeof(int) + bs2*sizeof(MatScalar))); \
150         a->s_maxnz += bs2*CHUNKSIZE; \
151         a->reallocs++; \
152         a->s_nz++; \
153       } \
154       N = nrow++ - 1;  \
155       /* shift up all the later entries in this row */ \
156       for (ii=N; ii>=_i; ii--) { \
157         rp[ii+1] = rp[ii]; \
158         ierr = PetscMemcpy(ap+bs2*(ii+1),ap+bs2*(ii),bs2*sizeof(MatScalar));CHKERRQ(ierr); \
159       } \
160       if (N>=_i) { ierr = PetscMemzero(ap+bs2*_i,bs2*sizeof(MatScalar));CHKERRQ(ierr); }  \
161       rp[_i]                      = bcol;  \
162       ap[bs2*_i + bs*cidx + ridx] = value;  \
163       a_noinsert:; \
164     ailen[brow] = nrow; \
165 }
166 #ifndef MatSetValues_SeqBAIJ_B_Private
167 #define  MatSetValues_SeqSBAIJ_B_Private(row,col,value,addv) \
168 { \
169     brow = row/bs;  \
170     rp   = bj + bi[brow]; ap = ba + bs2*bi[brow]; \
171     rmax = bimax[brow]; nrow = bilen[brow]; \
172       bcol = col/bs; \
173       ridx = row % bs; cidx = col % bs; \
174       low = 0; high = nrow; \
175       while (high-low > 3) { \
176         t = (low+high)/2; \
177         if (rp[t] > bcol) high = t; \
178         else              low  = t; \
179       } \
180       for (_i=low; _i<high; _i++) { \
181         if (rp[_i] > bcol) break; \
182         if (rp[_i] == bcol) { \
183           bap  = ap +  bs2*_i + bs*cidx + ridx; \
184           if (addv == ADD_VALUES) *bap += value;  \
185           else                    *bap  = value;  \
186           goto b_noinsert; \
187         } \
188       } \
189       if (b->nonew == 1) goto b_noinsert; \
190       else if (b->nonew == -1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero into matrix"); \
191       if (nrow >= rmax) { \
192         /* there is no extra room in row, therefore enlarge */ \
193         int       new_nz = bi[b->mbs] + CHUNKSIZE,len,*new_i,*new_j; \
194         MatScalar *new_a; \
195  \
196         if (b->nonew == -2) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero in the matrix"); \
197  \
198         /* malloc new storage space */ \
199         len   = new_nz*(sizeof(int)+bs2*sizeof(MatScalar))+(b->mbs+1)*sizeof(int); \
200         ierr  = PetscMalloc(len,&new_a);CHKERRQ(ierr); \
201         new_j = (int*)(new_a + bs2*new_nz); \
202         new_i = new_j + new_nz; \
203  \
204         /* copy over old data into new slots */ \
205         for (ii=0; ii<brow+1; ii++) {new_i[ii] = bi[ii];} \
206         for (ii=brow+1; ii<b->mbs+1; ii++) {new_i[ii] = bi[ii]+CHUNKSIZE;} \
207         ierr = PetscMemcpy(new_j,bj,(bi[brow]+nrow)*sizeof(int));CHKERRQ(ierr); \
208         len  = (new_nz - CHUNKSIZE - bi[brow] - nrow); \
209         ierr = PetscMemcpy(new_j+bi[brow]+nrow+CHUNKSIZE,bj+bi[brow]+nrow,len*sizeof(int));CHKERRQ(ierr); \
210         ierr = PetscMemcpy(new_a,ba,(bi[brow]+nrow)*bs2*sizeof(MatScalar));CHKERRQ(ierr); \
211         ierr = PetscMemzero(new_a+bs2*(bi[brow]+nrow),bs2*CHUNKSIZE*sizeof(MatScalar));CHKERRQ(ierr); \
212         ierr = PetscMemcpy(new_a+bs2*(bi[brow]+nrow+CHUNKSIZE), \
213                     ba+bs2*(bi[brow]+nrow),bs2*len*sizeof(MatScalar));CHKERRQ(ierr);  \
214         /* free up old matrix storage */ \
215         ierr = PetscFree(b->a);CHKERRQ(ierr);  \
216         if (!b->singlemalloc) { \
217           ierr = PetscFree(b->i);CHKERRQ(ierr); \
218           ierr = PetscFree(b->j);CHKERRQ(ierr); \
219         } \
220         ba = b->a = new_a; bi = b->i = new_i; bj = b->j = new_j;  \
221         b->singlemalloc = PETSC_TRUE; \
222  \
223         rp   = bj + bi[brow]; ap = ba + bs2*bi[brow]; \
224         rmax = bimax[brow] = bimax[brow] + CHUNKSIZE; \
225         PetscLogObjectMemory(B,CHUNKSIZE*(sizeof(int) + bs2*sizeof(MatScalar))); \
226         b->maxnz += bs2*CHUNKSIZE; \
227         b->reallocs++; \
228         b->nz++; \
229       } \
230       N = nrow++ - 1;  \
231       /* shift up all the later entries in this row */ \
232       for (ii=N; ii>=_i; ii--) { \
233         rp[ii+1] = rp[ii]; \
234         ierr = PetscMemcpy(ap+bs2*(ii+1),ap+bs2*(ii),bs2*sizeof(MatScalar));CHKERRQ(ierr); \
235       } \
236       if (N>=_i) { ierr = PetscMemzero(ap+bs2*_i,bs2*sizeof(MatScalar));CHKERRQ(ierr);}  \
237       rp[_i]                      = bcol;  \
238       ap[bs2*_i + bs*cidx + ridx] = value;  \
239       b_noinsert:; \
240     bilen[brow] = nrow; \
241 }
242 #endif
243 
244 #if defined(PETSC_USE_MAT_SINGLE)
245 #undef __FUNCT__
246 #define __FUNCT__ "MatSetValues_MPISBAIJ"
247 int MatSetValues_MPISBAIJ(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
248 {
249   Mat_MPISBAIJ *b = (Mat_MPISBAIJ*)mat->data;
250   int          ierr,i,N = m*n;
251   MatScalar    *vsingle;
252 
253   PetscFunctionBegin;
254   if (N > b->setvalueslen) {
255     if (b->setvaluescopy) {ierr = PetscFree(b->setvaluescopy);CHKERRQ(ierr);}
256     ierr = PetscMalloc(N*sizeof(MatScalar),&b->setvaluescopy);CHKERRQ(ierr);
257     b->setvalueslen  = N;
258   }
259   vsingle = b->setvaluescopy;
260 
261   for (i=0; i<N; i++) {
262     vsingle[i] = v[i];
263   }
264   ierr = MatSetValues_MPISBAIJ_MatScalar(mat,m,im,n,in,vsingle,addv);CHKERRQ(ierr);
265   PetscFunctionReturn(0);
266 }
267 
268 #undef __FUNCT__
269 #define __FUNCT__ "MatSetValuesBlocked_MPISBAIJ"
270 int MatSetValuesBlocked_MPISBAIJ(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
271 {
272   Mat_MPIBAIJ *b = (Mat_MPIBAIJ*)mat->data;
273   int         ierr,i,N = m*n*b->bs2;
274   MatScalar   *vsingle;
275 
276   PetscFunctionBegin;
277   if (N > b->setvalueslen) {
278     if (b->setvaluescopy) {ierr = PetscFree(b->setvaluescopy);CHKERRQ(ierr);}
279     ierr = PetscMalloc(N*sizeof(MatScalar),&b->setvaluescopy);CHKERRQ(ierr);
280     b->setvalueslen  = N;
281   }
282   vsingle = b->setvaluescopy;
283   for (i=0; i<N; i++) {
284     vsingle[i] = v[i];
285   }
286   ierr = MatSetValuesBlocked_MPISBAIJ_MatScalar(mat,m,im,n,in,vsingle,addv);CHKERRQ(ierr);
287   PetscFunctionReturn(0);
288 }
289 
290 #undef __FUNCT__
291 #define __FUNCT__ "MatSetValues_MPISBAIJ_HT"
292 int MatSetValues_MPISBAIJ_HT(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
293 {
294   Mat_MPIBAIJ *b = (Mat_MPIBAIJ*)mat->data;
295   int         ierr,i,N = m*n;
296   MatScalar   *vsingle;
297 
298   PetscFunctionBegin;
299   SETERRQ(1,"Function not yet written for SBAIJ format");
300   /* PetscFunctionReturn(0); */
301 }
302 
303 #undef __FUNCT__
304 #define __FUNCT__ "MatSetValuesBlocked_MPISBAIJ_HT"
305 int MatSetValuesBlocked_MPISBAIJ_HT(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
306 {
307   Mat_MPIBAIJ *b = (Mat_MPIBAIJ*)mat->data;
308   int         ierr,i,N = m*n*b->bs2;
309   MatScalar   *vsingle;
310 
311   PetscFunctionBegin;
312   SETERRQ(1,"Function not yet written for SBAIJ format");
313   /* PetscFunctionReturn(0); */
314 }
315 #endif
316 
317 /* Only add/insert a(i,j) with i<=j (blocks).
318    Any a(i,j) with i>j input by user is ingored.
319 */
320 #undef __FUNCT__
321 #define __FUNCT__ "MatSetValues_MPIBAIJ"
322 int MatSetValues_MPISBAIJ_MatScalar(Mat mat,int m,int *im,int n,int *in,MatScalar *v,InsertMode addv)
323 {
324   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
325   MatScalar    value;
326   PetscTruth   roworiented = baij->roworiented;
327   int          ierr,i,j,row,col;
328   int          rstart_orig=baij->rstart_bs;
329   int          rend_orig=baij->rend_bs,cstart_orig=baij->cstart_bs;
330   int          cend_orig=baij->cend_bs,bs=baij->bs;
331 
332   /* Some Variables required in the macro */
333   Mat          A = baij->A;
334   Mat_SeqSBAIJ *a = (Mat_SeqSBAIJ*)(A)->data;
335   int          *aimax=a->imax,*ai=a->i,*ailen=a->ilen,*aj=a->j;
336   MatScalar    *aa=a->a;
337 
338   Mat          B = baij->B;
339   Mat_SeqBAIJ  *b = (Mat_SeqBAIJ*)(B)->data;
340   int          *bimax=b->imax,*bi=b->i,*bilen=b->ilen,*bj=b->j;
341   MatScalar    *ba=b->a;
342 
343   int          *rp,ii,nrow,_i,rmax,N,brow,bcol;
344   int          low,high,t,ridx,cidx,bs2=a->bs2;
345   MatScalar    *ap,*bap;
346 
347   /* for stash */
348   int          n_loc, *in_loc=0;
349   MatScalar    *v_loc=0;
350 
351   PetscFunctionBegin;
352 
353   if(!baij->donotstash){
354     ierr = PetscMalloc(n*sizeof(int),&in_loc);CHKERRQ(ierr);
355     ierr = PetscMalloc(n*sizeof(MatScalar),&v_loc);CHKERRQ(ierr);
356   }
357 
358   for (i=0; i<m; i++) {
359     if (im[i] < 0) continue;
360 #if defined(PETSC_USE_BOPT_g)
361     if (im[i] >= mat->M) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Row too large");
362 #endif
363     if (im[i] >= rstart_orig && im[i] < rend_orig) { /* this processor entry */
364       row = im[i] - rstart_orig;              /* local row index */
365       for (j=0; j<n; j++) {
366         if (im[i]/bs > in[j]/bs) continue;    /* ignore lower triangular blocks */
367         if (in[j] >= cstart_orig && in[j] < cend_orig){  /* diag entry (A) */
368           col = in[j] - cstart_orig;          /* local col index */
369           brow = row/bs; bcol = col/bs;
370           if (brow > bcol) continue;  /* ignore lower triangular blocks of A */
371           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
372           MatSetValues_SeqSBAIJ_A_Private(row,col,value,addv);
373           /* ierr = MatSetValues_SeqBAIJ(baij->A,1,&row,1,&col,&value,addv);CHKERRQ(ierr); */
374         } else if (in[j] < 0) continue;
375 #if defined(PETSC_USE_BOPT_g)
376         else if (in[j] >= mat->N) {SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Col too large");}
377 #endif
378         else {  /* off-diag entry (B) */
379           if (mat->was_assembled) {
380             if (!baij->colmap) {
381               ierr = CreateColmap_MPISBAIJ_Private(mat);CHKERRQ(ierr);
382             }
383 #if defined (PETSC_USE_CTABLE)
384             ierr = PetscTableFind(baij->colmap,in[j]/bs + 1,&col);CHKERRQ(ierr);
385             col  = col - 1 + in[j]%bs;
386 #else
387             col = baij->colmap[in[j]/bs] - 1 + in[j]%bs;
388 #endif
389             if (col < 0 && !((Mat_SeqSBAIJ*)(baij->A->data))->nonew) {
390               ierr = DisAssemble_MPISBAIJ(mat);CHKERRQ(ierr);
391               col =  in[j];
392               /* Reinitialize the variables required by MatSetValues_SeqBAIJ_B_Private() */
393               B = baij->B;
394               b = (Mat_SeqBAIJ*)(B)->data;
395               bimax=b->imax;bi=b->i;bilen=b->ilen;bj=b->j;
396               ba=b->a;
397             }
398           } else col = in[j];
399           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
400           MatSetValues_SeqSBAIJ_B_Private(row,col,value,addv);
401           /* ierr = MatSetValues_SeqBAIJ(baij->B,1,&row,1,&col,&value,addv);CHKERRQ(ierr); */
402         }
403       }
404     } else {  /* off processor entry */
405       if (!baij->donotstash) {
406         n_loc = 0;
407         for (j=0; j<n; j++){
408           if (im[i]/bs > in[j]/bs) continue; /* ignore lower triangular blocks */
409           in_loc[n_loc] = in[j];
410           if (roworiented) {
411             v_loc[n_loc] = v[i*n+j];
412           } else {
413             v_loc[n_loc] = v[j*m+i];
414           }
415           n_loc++;
416         }
417         ierr = MatStashValuesRow_Private(&mat->stash,im[i],n_loc,in_loc,v_loc);CHKERRQ(ierr);
418       }
419     }
420   }
421 
422   if(!baij->donotstash){
423     ierr = PetscFree(in_loc);CHKERRQ(ierr);
424     ierr = PetscFree(v_loc);CHKERRQ(ierr);
425   }
426   PetscFunctionReturn(0);
427 }
428 
429 #undef __FUNCT__
430 #define __FUNCT__ "MatSetValuesBlocked_MPISBAIJ"
431 int MatSetValuesBlocked_MPISBAIJ_MatScalar(Mat mat,int m,int *im,int n,int *in,MatScalar *v,InsertMode addv)
432 {
433   PetscFunctionBegin;
434   SETERRQ(1,"Function not yet written for SBAIJ format");
435   /* PetscFunctionReturn(0); */
436 }
437 
438 #define HASH_KEY 0.6180339887
439 #define HASH(size,key,tmp) (tmp = (key)*HASH_KEY,(int)((size)*(tmp-(int)tmp)))
440 /* #define HASH(size,key) ((int)((size)*fmod(((key)*HASH_KEY),1))) */
441 /* #define HASH(size,key,tmp) ((int)((size)*fmod(((key)*HASH_KEY),1))) */
442 #undef __FUNCT__
443 #define __FUNCT__ "MatSetValues_MPISBAIJ_HT_MatScalar"
444 int MatSetValues_MPISBAIJ_HT_MatScalar(Mat mat,int m,int *im,int n,int *in,MatScalar *v,InsertMode addv)
445 {
446   PetscFunctionBegin;
447   SETERRQ(1,"Function not yet written for SBAIJ format");
448   /* PetscFunctionReturn(0); */
449 }
450 
451 #undef __FUNCT__
452 #define __FUNCT__ "MatSetValuesBlocked_MPISBAIJ_HT_MatScalar"
453 int MatSetValuesBlocked_MPISBAIJ_HT_MatScalar(Mat mat,int m,int *im,int n,int *in,MatScalar *v,InsertMode addv)
454 {
455   PetscFunctionBegin;
456   SETERRQ(1,"Function not yet written for SBAIJ format");
457   /* PetscFunctionReturn(0); */
458 }
459 
460 #undef __FUNCT__
461 #define __FUNCT__ "MatGetValues_MPISBAIJ"
462 int MatGetValues_MPISBAIJ(Mat mat,int m,int *idxm,int n,int *idxn,Scalar *v)
463 {
464   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
465   int          bs=baij->bs,ierr,i,j,bsrstart = baij->rstart*bs,bsrend = baij->rend*bs;
466   int          bscstart = baij->cstart*bs,bscend = baij->cend*bs,row,col,data;
467 
468   PetscFunctionBegin;
469   for (i=0; i<m; i++) {
470     if (idxm[i] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Negative row");
471     if (idxm[i] >= mat->M) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Row too large");
472     if (idxm[i] >= bsrstart && idxm[i] < bsrend) {
473       row = idxm[i] - bsrstart;
474       for (j=0; j<n; j++) {
475         if (idxn[j] < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Negative column");
476         if (idxn[j] >= mat->N) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Column too large");
477         if (idxn[j] >= bscstart && idxn[j] < bscend){
478           col = idxn[j] - bscstart;
479           ierr = MatGetValues_SeqSBAIJ(baij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
480         } else {
481           if (!baij->colmap) {
482             ierr = CreateColmap_MPISBAIJ_Private(mat);CHKERRQ(ierr);
483           }
484 #if defined (PETSC_USE_CTABLE)
485           ierr = PetscTableFind(baij->colmap,idxn[j]/bs+1,&data);CHKERRQ(ierr);
486           data --;
487 #else
488           data = baij->colmap[idxn[j]/bs]-1;
489 #endif
490           if((data < 0) || (baij->garray[data/bs] != idxn[j]/bs)) *(v+i*n+j) = 0.0;
491           else {
492             col  = data + idxn[j]%bs;
493             ierr = MatGetValues_SeqSBAIJ(baij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
494           }
495         }
496       }
497     } else {
498       SETERRQ(PETSC_ERR_SUP,"Only local values currently supported");
499     }
500   }
501  PetscFunctionReturn(0);
502 }
503 
504 #undef __FUNCT__
505 #define __FUNCT__ "MatNorm_MPISBAIJ"
506 int MatNorm_MPISBAIJ(Mat mat,NormType type,PetscReal *norm)
507 {
508   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
509   /* Mat_SeqSBAIJ *amat = (Mat_SeqSBAIJ*)baij->A->data; */
510   /* Mat_SeqBAIJ  *bmat = (Mat_SeqBAIJ*)baij->B->data; */
511   int        ierr;
512   PetscReal  sum[2],*lnorm2;
513 
514   PetscFunctionBegin;
515   if (baij->size == 1) {
516     ierr =  MatNorm(baij->A,type,norm);CHKERRQ(ierr);
517   } else {
518     if (type == NORM_FROBENIUS) {
519       ierr = PetscMalloc(2*sizeof(double),&lnorm2);CHKERRQ(ierr);
520       ierr =  MatNorm(baij->A,type,lnorm2);CHKERRQ(ierr);
521       *lnorm2 = (*lnorm2)*(*lnorm2); lnorm2++;            /* squar power of norm(A) */
522       ierr =  MatNorm(baij->B,type,lnorm2);CHKERRQ(ierr);
523       *lnorm2 = (*lnorm2)*(*lnorm2); lnorm2--;             /* squar power of norm(B) */
524       /*
525       ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
526       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d], lnorm2=%g, %g\n",rank,lnorm2[0],lnorm2[1]);
527       */
528       ierr = MPI_Allreduce(lnorm2,&sum,2,MPI_DOUBLE,MPI_SUM,mat->comm);CHKERRQ(ierr);
529       /*
530       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d], sum=%g, %g\n",rank,sum[0],sum[1]);
531       PetscSynchronizedFlush(PETSC_COMM_WORLD); */
532 
533       *norm = sqrt(sum[0] + 2*sum[1]);
534       ierr = PetscFree(lnorm2);CHKERRQ(ierr);
535     } else {
536       SETERRQ(PETSC_ERR_SUP,"No support for this norm yet");
537     }
538   }
539   PetscFunctionReturn(0);
540 }
541 
542 /*
543   Creates the hash table, and sets the table
544   This table is created only once.
545   If new entried need to be added to the matrix
546   then the hash table has to be destroyed and
547   recreated.
548 */
549 #undef __FUNCT__
550 #define __FUNCT__ "MatCreateHashTable_MPISBAIJ_Private"
551 int MatCreateHashTable_MPISBAIJ_Private(Mat mat,PetscReal factor)
552 {
553   PetscFunctionBegin;
554   SETERRQ(1,"Function not yet written for SBAIJ format");
555   /* PetscFunctionReturn(0); */
556 }
557 
558 #undef __FUNCT__
559 #define __FUNCT__ "MatAssemblyBegin_MPISBAIJ"
560 int MatAssemblyBegin_MPISBAIJ(Mat mat,MatAssemblyType mode)
561 {
562   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
563   int         ierr,nstash,reallocs;
564   InsertMode  addv;
565 
566   PetscFunctionBegin;
567   if (baij->donotstash) {
568     PetscFunctionReturn(0);
569   }
570 
571   /* make sure all processors are either in INSERTMODE or ADDMODE */
572   ierr = MPI_Allreduce(&mat->insertmode,&addv,1,MPI_INT,MPI_BOR,mat->comm);CHKERRQ(ierr);
573   if (addv == (ADD_VALUES|INSERT_VALUES)) {
574     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
575   }
576   mat->insertmode = addv; /* in case this processor had no cache */
577 
578   ierr = MatStashScatterBegin_Private(&mat->stash,baij->rowners_bs);CHKERRQ(ierr);
579   ierr = MatStashScatterBegin_Private(&mat->bstash,baij->rowners);CHKERRQ(ierr);
580   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
581   PetscLogInfo(0,"MatAssemblyBegin_MPISBAIJ:Stash has %d entries,uses %d mallocs.\n",nstash,reallocs);
582   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
583   PetscLogInfo(0,"MatAssemblyBegin_MPISBAIJ:Block-Stash has %d entries, uses %d mallocs.\n",nstash,reallocs);
584   PetscFunctionReturn(0);
585 }
586 
587 #undef __FUNCT__
588 #define __FUNCT__ "MatAssemblyEnd_MPISBAIJ"
589 int MatAssemblyEnd_MPISBAIJ(Mat mat,MatAssemblyType mode)
590 {
591   Mat_MPISBAIJ *baij=(Mat_MPISBAIJ*)mat->data;
592   Mat_SeqSBAIJ  *a=(Mat_SeqSBAIJ*)baij->A->data;
593   Mat_SeqBAIJ  *b=(Mat_SeqBAIJ*)baij->B->data;
594   int         i,j,rstart,ncols,n,ierr,flg,bs2=baij->bs2;
595   int         *row,*col,other_disassembled;
596   PetscTruth  r1,r2,r3;
597   MatScalar   *val;
598   InsertMode  addv = mat->insertmode;
599   /* int         rank;*/
600 
601   PetscFunctionBegin;
602   /* remove 2 line below later */
603   /*ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &rank);CHKERRQ(ierr); */
604 
605   if (!baij->donotstash) {
606     while (1) {
607       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
608       /*
609       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d]: in AssemblyEnd, stash, flg=%d\n",rank,flg);
610       PetscSynchronizedFlush(PETSC_COMM_WORLD);
611       */
612       if (!flg) break;
613 
614       for (i=0; i<n;) {
615         /* Now identify the consecutive vals belonging to the same row */
616         for (j=i,rstart=row[j]; j<n; j++) { if (row[j] != rstart) break; }
617         if (j < n) ncols = j-i;
618         else       ncols = n-i;
619         /* Now assemble all these values with a single function call */
620         ierr = MatSetValues_MPISBAIJ_MatScalar(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
621         i = j;
622       }
623     }
624     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
625     /* Now process the block-stash. Since the values are stashed column-oriented,
626        set the roworiented flag to column oriented, and after MatSetValues()
627        restore the original flags */
628     r1 = baij->roworiented;
629     r2 = a->roworiented;
630     r3 = b->roworiented;
631     baij->roworiented = PETSC_FALSE;
632     a->roworiented    = PETSC_FALSE;
633     b->roworiented    = PETSC_FALSE;
634     while (1) {
635       ierr = MatStashScatterGetMesg_Private(&mat->bstash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
636       if (!flg) break;
637 
638       for (i=0; i<n;) {
639         /* Now identify the consecutive vals belonging to the same row */
640         for (j=i,rstart=row[j]; j<n; j++) { if (row[j] != rstart) break; }
641         if (j < n) ncols = j-i;
642         else       ncols = n-i;
643         ierr = MatSetValuesBlocked_MPISBAIJ_MatScalar(mat,1,row+i,ncols,col+i,val+i*bs2,addv);CHKERRQ(ierr);
644         i = j;
645       }
646     }
647     ierr = MatStashScatterEnd_Private(&mat->bstash);CHKERRQ(ierr);
648     baij->roworiented = r1;
649     a->roworiented    = r2;
650     b->roworiented    = r3;
651   }
652 
653   ierr = MatAssemblyBegin(baij->A,mode);CHKERRQ(ierr);
654   ierr = MatAssemblyEnd(baij->A,mode);CHKERRQ(ierr);
655 
656   /* determine if any processor has disassembled, if so we must
657      also disassemble ourselfs, in order that we may reassemble. */
658   /*
659      if nonzero structure of submatrix B cannot change then we know that
660      no processor disassembled thus we can skip this stuff
661   */
662   if (!((Mat_SeqBAIJ*)baij->B->data)->nonew)  {
663     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPI_INT,MPI_PROD,mat->comm);CHKERRQ(ierr);
664     if (mat->was_assembled && !other_disassembled) {
665       ierr = DisAssemble_MPISBAIJ(mat);CHKERRQ(ierr);
666     }
667   }
668 
669   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
670     ierr = MatSetUpMultiply_MPISBAIJ(mat);CHKERRQ(ierr);
671   }
672   ierr = MatAssemblyBegin(baij->B,mode);CHKERRQ(ierr);
673   ierr = MatAssemblyEnd(baij->B,mode);CHKERRQ(ierr);
674 
675 #if defined(PETSC_USE_BOPT_g)
676   if (baij->ht && mode== MAT_FINAL_ASSEMBLY) {
677     PetscLogInfo(0,"MatAssemblyEnd_MPISBAIJ:Average Hash Table Search in MatSetValues = %5.2f\n",((double)baij->ht_total_ct)/baij->ht_insert_ct);
678     baij->ht_total_ct  = 0;
679     baij->ht_insert_ct = 0;
680   }
681 #endif
682   if (baij->ht_flag && !baij->ht && mode == MAT_FINAL_ASSEMBLY) {
683     ierr = MatCreateHashTable_MPISBAIJ_Private(mat,baij->ht_fact);CHKERRQ(ierr);
684     mat->ops->setvalues        = MatSetValues_MPISBAIJ_HT;
685     mat->ops->setvaluesblocked = MatSetValuesBlocked_MPISBAIJ_HT;
686   }
687 
688   if (baij->rowvalues) {
689     ierr = PetscFree(baij->rowvalues);CHKERRQ(ierr);
690     baij->rowvalues = 0;
691   }
692   PetscFunctionReturn(0);
693 }
694 
695 #undef __FUNCT__
696 #define __FUNCT__ "MatView_MPISBAIJ_ASCIIorDraworSocket"
697 static int MatView_MPISBAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
698 {
699   Mat_MPISBAIJ      *baij = (Mat_MPISBAIJ*)mat->data;
700   int               ierr,bs = baij->bs,size = baij->size,rank = baij->rank;
701   PetscTruth        isascii,isdraw;
702   PetscViewer       sviewer;
703   PetscViewerFormat format;
704 
705   PetscFunctionBegin;
706   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&isascii);CHKERRQ(ierr);
707   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);CHKERRQ(ierr);
708   if (isascii) {
709     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
710     if (format == PETSC_VIEWER_ASCII_INFO_LONG) {
711       MatInfo info;
712       ierr = MPI_Comm_rank(mat->comm,&rank);CHKERRQ(ierr);
713       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
714       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %d nz %d nz alloced %d bs %d mem %d\n",
715               rank,mat->m,(int)info.nz_used*bs,(int)info.nz_allocated*bs,
716               baij->bs,(int)info.memory);CHKERRQ(ierr);
717       ierr = MatGetInfo(baij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
718       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %d \n",rank,(int)info.nz_used*bs);CHKERRQ(ierr);
719       ierr = MatGetInfo(baij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
720       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %d \n",rank,(int)info.nz_used*bs);CHKERRQ(ierr);
721       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
722       ierr = VecScatterView(baij->Mvctx,viewer);CHKERRQ(ierr);
723       PetscFunctionReturn(0);
724     } else if (format == PETSC_VIEWER_ASCII_INFO) {
725       ierr = PetscViewerASCIIPrintf(viewer,"  block size is %d\n",bs);CHKERRQ(ierr);
726       PetscFunctionReturn(0);
727     }
728   }
729 
730   if (isdraw) {
731     PetscDraw       draw;
732     PetscTruth isnull;
733     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
734     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
735   }
736 
737   if (size == 1) {
738     ierr = PetscObjectSetName((PetscObject)baij->A,mat->name);CHKERRQ(ierr);
739     ierr = MatView(baij->A,viewer);CHKERRQ(ierr);
740   } else {
741     /* assemble the entire matrix onto first processor. */
742     Mat         A;
743     Mat_SeqSBAIJ *Aloc;
744     Mat_SeqBAIJ *Bloc;
745     int         M = mat->M,N = mat->N,*ai,*aj,col,i,j,k,*rvals,mbs = baij->mbs;
746     MatScalar   *a;
747 
748     if (!rank) {
749       ierr = MatCreateMPISBAIJ(mat->comm,baij->bs,M,N,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);CHKERRQ(ierr);
750     } else {
751       ierr = MatCreateMPISBAIJ(mat->comm,baij->bs,0,0,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);CHKERRQ(ierr);
752     }
753     PetscLogObjectParent(mat,A);
754 
755     /* copy over the A part */
756     Aloc  = (Mat_SeqSBAIJ*)baij->A->data;
757     ai    = Aloc->i; aj = Aloc->j; a = Aloc->a;
758     ierr  = PetscMalloc(bs*sizeof(int),&rvals);CHKERRQ(ierr);
759 
760     for (i=0; i<mbs; i++) {
761       rvals[0] = bs*(baij->rstart + i);
762       for (j=1; j<bs; j++) { rvals[j] = rvals[j-1] + 1; }
763       for (j=ai[i]; j<ai[i+1]; j++) {
764         col = (baij->cstart+aj[j])*bs;
765         for (k=0; k<bs; k++) {
766           ierr = MatSetValues_MPISBAIJ_MatScalar(A,bs,rvals,1,&col,a,INSERT_VALUES);CHKERRQ(ierr);
767           col++; a += bs;
768         }
769       }
770     }
771     /* copy over the B part */
772     Bloc = (Mat_SeqBAIJ*)baij->B->data;
773     ai = Bloc->i; aj = Bloc->j; a = Bloc->a;
774     for (i=0; i<mbs; i++) {
775       rvals[0] = bs*(baij->rstart + i);
776       for (j=1; j<bs; j++) { rvals[j] = rvals[j-1] + 1; }
777       for (j=ai[i]; j<ai[i+1]; j++) {
778         col = baij->garray[aj[j]]*bs;
779         for (k=0; k<bs; k++) {
780           ierr = MatSetValues_MPISBAIJ_MatScalar(A,bs,rvals,1,&col,a,INSERT_VALUES);CHKERRQ(ierr);
781           col++; a += bs;
782         }
783       }
784     }
785     ierr = PetscFree(rvals);CHKERRQ(ierr);
786     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
787     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
788     /*
789        Everyone has to call to draw the matrix since the graphics waits are
790        synchronized across all processors that share the PetscDraw object
791     */
792     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
793     if (!rank) {
794       ierr = PetscObjectSetName((PetscObject)((Mat_MPISBAIJ*)(A->data))->A,mat->name);CHKERRQ(ierr);
795       ierr = MatView(((Mat_MPISBAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
796     }
797     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
798     ierr = MatDestroy(A);CHKERRQ(ierr);
799   }
800   PetscFunctionReturn(0);
801 }
802 
803 #undef __FUNCT__
804 #define __FUNCT__ "MatView_MPISBAIJ"
805 int MatView_MPISBAIJ(Mat mat,PetscViewer viewer)
806 {
807   int        ierr;
808   PetscTruth isascii,isdraw,issocket,isbinary;
809 
810   PetscFunctionBegin;
811   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&isascii);CHKERRQ(ierr);
812   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);CHKERRQ(ierr);
813   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_SOCKET,&issocket);CHKERRQ(ierr);
814   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);CHKERRQ(ierr);
815   if (isascii || isdraw || issocket || isbinary) {
816     ierr = MatView_MPISBAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
817   } else {
818     SETERRQ1(1,"Viewer type %s not supported by MPISBAIJ matrices",((PetscObject)viewer)->type_name);
819   }
820   PetscFunctionReturn(0);
821 }
822 
823 #undef __FUNCT__
824 #define __FUNCT__ "MatDestroy_MPISBAIJ"
825 int MatDestroy_MPISBAIJ(Mat mat)
826 {
827   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
828   int         ierr;
829 
830   PetscFunctionBegin;
831 #if defined(PETSC_USE_LOG)
832   PetscLogObjectState((PetscObject)mat,"Rows=%d,Cols=%d",mat->M,mat->N);
833 #endif
834   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
835   ierr = MatStashDestroy_Private(&mat->bstash);CHKERRQ(ierr);
836   ierr = PetscFree(baij->rowners);CHKERRQ(ierr);
837   ierr = MatDestroy(baij->A);CHKERRQ(ierr);
838   ierr = MatDestroy(baij->B);CHKERRQ(ierr);
839 #if defined (PETSC_USE_CTABLE)
840   if (baij->colmap) {ierr = PetscTableDelete(baij->colmap);CHKERRQ(ierr);}
841 #else
842   if (baij->colmap) {ierr = PetscFree(baij->colmap);CHKERRQ(ierr);}
843 #endif
844   if (baij->garray) {ierr = PetscFree(baij->garray);CHKERRQ(ierr);}
845   if (baij->lvec)   {ierr = VecDestroy(baij->lvec);CHKERRQ(ierr);}
846   if (baij->Mvctx)  {ierr = VecScatterDestroy(baij->Mvctx);CHKERRQ(ierr);}
847   if (baij->rowvalues) {ierr = PetscFree(baij->rowvalues);CHKERRQ(ierr);}
848   if (baij->barray) {ierr = PetscFree(baij->barray);CHKERRQ(ierr);}
849   if (baij->hd) {ierr = PetscFree(baij->hd);CHKERRQ(ierr);}
850 #if defined(PETSC_USE_MAT_SINGLE)
851   if (baij->setvaluescopy) {ierr = PetscFree(baij->setvaluescopy);CHKERRQ(ierr);}
852 #endif
853   ierr = PetscFree(baij);CHKERRQ(ierr);
854   PetscFunctionReturn(0);
855 }
856 
857 #undef __FUNCT__
858 #define __FUNCT__ "MatMult_MPISBAIJ"
859 int MatMult_MPISBAIJ(Mat A,Vec xx,Vec yy)
860 {
861   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
862   int         ierr,nt;
863 
864   PetscFunctionBegin;
865   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
866   if (nt != A->n) {
867     SETERRQ(PETSC_ERR_ARG_SIZ,"Incompatible partition of A and xx");
868   }
869   ierr = VecGetLocalSize(yy,&nt);CHKERRQ(ierr);
870   if (nt != A->m) {
871     SETERRQ(PETSC_ERR_ARG_SIZ,"Incompatible parition of A and yy");
872   }
873 
874   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
875   /* do diagonal part */
876   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
877   /* do supperdiagonal part */
878   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
879   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
880   /* do subdiagonal part */
881   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
882   ierr = VecScatterBegin(a->lvec,yy,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
883   ierr = VecScatterEnd(a->lvec,yy,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
884 
885   PetscFunctionReturn(0);
886 }
887 
888 #undef __FUNCT__
889 #define __FUNCT__ "MatMultAdd_MPISBAIJ"
890 int MatMultAdd_MPISBAIJ(Mat A,Vec xx,Vec yy,Vec zz)
891 {
892   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
893   int        ierr;
894 
895   PetscFunctionBegin;
896   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
897   /* do diagonal part */
898   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
899   /* do supperdiagonal part */
900   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD,a->Mvctx);CHKERRQ(ierr);
901   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
902 
903   /* do subdiagonal part */
904   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
905   ierr = VecScatterBegin(a->lvec,zz,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
906   ierr = VecScatterEnd(a->lvec,zz,ADD_VALUES,SCATTER_REVERSE,a->Mvctx);CHKERRQ(ierr);
907 
908   PetscFunctionReturn(0);
909 }
910 
911 #undef __FUNCT__
912 #define __FUNCT__ "MatMultTranspose_MPISBAIJ"
913 int MatMultTranspose_MPISBAIJ(Mat A,Vec xx,Vec yy)
914 {
915   PetscFunctionBegin;
916   SETERRQ(1,"Matrix is symmetric. Call MatMult().");
917   /* PetscFunctionReturn(0); */
918 }
919 
920 #undef __FUNCT__
921 #define __FUNCT__ "MatMultTransposeAdd_MPISBAIJ"
922 int MatMultTransposeAdd_MPISBAIJ(Mat A,Vec xx,Vec yy,Vec zz)
923 {
924   PetscFunctionBegin;
925   SETERRQ(1,"Matrix is symmetric. Call MatMultAdd().");
926   /* PetscFunctionReturn(0); */
927 }
928 
929 /*
930   This only works correctly for square matrices where the subblock A->A is the
931    diagonal block
932 */
933 #undef __FUNCT__
934 #define __FUNCT__ "MatGetDiagonal_MPISBAIJ"
935 int MatGetDiagonal_MPISBAIJ(Mat A,Vec v)
936 {
937   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
938   int         ierr;
939 
940   PetscFunctionBegin;
941   /* if (a->M != a->N) SETERRQ(PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block"); */
942   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
943   PetscFunctionReturn(0);
944 }
945 
946 #undef __FUNCT__
947 #define __FUNCT__ "MatScale_MPISBAIJ"
948 int MatScale_MPISBAIJ(Scalar *aa,Mat A)
949 {
950   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
951   int         ierr;
952 
953   PetscFunctionBegin;
954   ierr = MatScale(aa,a->A);CHKERRQ(ierr);
955   ierr = MatScale(aa,a->B);CHKERRQ(ierr);
956   PetscFunctionReturn(0);
957 }
958 
959 #undef __FUNCT__
960 #define __FUNCT__ "MatGetOwnershipRange_MPISBAIJ"
961 int MatGetOwnershipRange_MPISBAIJ(Mat matin,int *m,int *n)
962 {
963   Mat_MPISBAIJ *mat = (Mat_MPISBAIJ*)matin->data;
964 
965   PetscFunctionBegin;
966   if (m) *m = mat->rstart*mat->bs;
967   if (n) *n = mat->rend*mat->bs;
968   PetscFunctionReturn(0);
969 }
970 
971 #undef __FUNCT__
972 #define __FUNCT__ "MatGetRow_MPISBAIJ"
973 int MatGetRow_MPISBAIJ(Mat matin,int row,int *nz,int **idx,Scalar **v)
974 {
975   Mat_MPISBAIJ *mat = (Mat_MPISBAIJ*)matin->data;
976   Scalar     *vworkA,*vworkB,**pvA,**pvB,*v_p;
977   int        bs = mat->bs,bs2 = mat->bs2,i,ierr,*cworkA,*cworkB,**pcA,**pcB;
978   int        nztot,nzA,nzB,lrow,brstart = mat->rstart*bs,brend = mat->rend*bs;
979   int        *cmap,*idx_p,cstart = mat->cstart;
980 
981   PetscFunctionBegin;
982   if (mat->getrowactive == PETSC_TRUE) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Already active");
983   mat->getrowactive = PETSC_TRUE;
984 
985   if (!mat->rowvalues && (idx || v)) {
986     /*
987         allocate enough space to hold information from the longest row.
988     */
989     Mat_SeqSBAIJ *Aa = (Mat_SeqSBAIJ*)mat->A->data;
990     Mat_SeqBAIJ  *Ba = (Mat_SeqBAIJ*)mat->B->data;
991     int     max = 1,mbs = mat->mbs,tmp;
992     for (i=0; i<mbs; i++) {
993       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i]; /* row length */
994       if (max < tmp) { max = tmp; }
995     }
996     ierr = PetscMalloc(max*bs2*(sizeof(int)+sizeof(Scalar)),&mat->rowvalues);CHKERRQ(ierr);
997     mat->rowindices = (int*)(mat->rowvalues + max*bs2);
998   }
999 
1000   if (row < brstart || row >= brend) SETERRQ(PETSC_ERR_SUP,"Only local rows")
1001   lrow = row - brstart;  /* local row index */
1002 
1003   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1004   if (!v)   {pvA = 0; pvB = 0;}
1005   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1006   ierr = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1007   ierr = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1008   nztot = nzA + nzB;
1009 
1010   cmap  = mat->garray;
1011   if (v  || idx) {
1012     if (nztot) {
1013       /* Sort by increasing column numbers, assuming A and B already sorted */
1014       int imark = -1;
1015       if (v) {
1016         *v = v_p = mat->rowvalues;
1017         for (i=0; i<nzB; i++) {
1018           if (cmap[cworkB[i]/bs] < cstart)   v_p[i] = vworkB[i];
1019           else break;
1020         }
1021         imark = i;
1022         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1023         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1024       }
1025       if (idx) {
1026         *idx = idx_p = mat->rowindices;
1027         if (imark > -1) {
1028           for (i=0; i<imark; i++) {
1029             idx_p[i] = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs;
1030           }
1031         } else {
1032           for (i=0; i<nzB; i++) {
1033             if (cmap[cworkB[i]/bs] < cstart)
1034               idx_p[i] = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs ;
1035             else break;
1036           }
1037           imark = i;
1038         }
1039         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart*bs + cworkA[i];
1040         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]/bs]*bs + cworkB[i]%bs ;
1041       }
1042     } else {
1043       if (idx) *idx = 0;
1044       if (v)   *v   = 0;
1045     }
1046   }
1047   *nz = nztot;
1048   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1049   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1050   PetscFunctionReturn(0);
1051 }
1052 
1053 #undef __FUNCT__
1054 #define __FUNCT__ "MatRestoreRow_MPISBAIJ"
1055 int MatRestoreRow_MPISBAIJ(Mat mat,int row,int *nz,int **idx,Scalar **v)
1056 {
1057   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
1058 
1059   PetscFunctionBegin;
1060   if (baij->getrowactive == PETSC_FALSE) {
1061     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"MatGetRow not called");
1062   }
1063   baij->getrowactive = PETSC_FALSE;
1064   PetscFunctionReturn(0);
1065 }
1066 
1067 #undef __FUNCT__
1068 #define __FUNCT__ "MatGetBlockSize_MPISBAIJ"
1069 int MatGetBlockSize_MPISBAIJ(Mat mat,int *bs)
1070 {
1071   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
1072 
1073   PetscFunctionBegin;
1074   *bs = baij->bs;
1075   PetscFunctionReturn(0);
1076 }
1077 
1078 #undef __FUNCT__
1079 #define __FUNCT__ "MatZeroEntries_MPISBAIJ"
1080 int MatZeroEntries_MPISBAIJ(Mat A)
1081 {
1082   Mat_MPISBAIJ *l = (Mat_MPISBAIJ*)A->data;
1083   int         ierr;
1084 
1085   PetscFunctionBegin;
1086   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
1087   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
1088   PetscFunctionReturn(0);
1089 }
1090 
1091 #undef __FUNCT__
1092 #define __FUNCT__ "MatGetInfo_MPISBAIJ"
1093 int MatGetInfo_MPISBAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1094 {
1095   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)matin->data;
1096   Mat         A = a->A,B = a->B;
1097   int         ierr;
1098   PetscReal   isend[5],irecv[5];
1099 
1100   PetscFunctionBegin;
1101   info->block_size     = (double)a->bs;
1102   ierr = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1103   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1104   isend[3] = info->memory;  isend[4] = info->mallocs;
1105   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1106   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1107   isend[3] += info->memory;  isend[4] += info->mallocs;
1108   if (flag == MAT_LOCAL) {
1109     info->nz_used      = isend[0];
1110     info->nz_allocated = isend[1];
1111     info->nz_unneeded  = isend[2];
1112     info->memory       = isend[3];
1113     info->mallocs      = isend[4];
1114   } else if (flag == MAT_GLOBAL_MAX) {
1115     ierr = MPI_Allreduce(isend,irecv,5,MPI_DOUBLE,MPI_MAX,matin->comm);CHKERRQ(ierr);
1116     info->nz_used      = irecv[0];
1117     info->nz_allocated = irecv[1];
1118     info->nz_unneeded  = irecv[2];
1119     info->memory       = irecv[3];
1120     info->mallocs      = irecv[4];
1121   } else if (flag == MAT_GLOBAL_SUM) {
1122     ierr = MPI_Allreduce(isend,irecv,5,MPI_DOUBLE,MPI_SUM,matin->comm);CHKERRQ(ierr);
1123     info->nz_used      = irecv[0];
1124     info->nz_allocated = irecv[1];
1125     info->nz_unneeded  = irecv[2];
1126     info->memory       = irecv[3];
1127     info->mallocs      = irecv[4];
1128   } else {
1129     SETERRQ1(1,"Unknown MatInfoType argument %d",flag);
1130   }
1131   info->rows_global       = (double)A->M;
1132   info->columns_global    = (double)A->N;
1133   info->rows_local        = (double)A->m;
1134   info->columns_local     = (double)A->N;
1135   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1136   info->fill_ratio_needed = 0;
1137   info->factor_mallocs    = 0;
1138   PetscFunctionReturn(0);
1139 }
1140 
1141 #undef __FUNCT__
1142 #define __FUNCT__ "MatSetOption_MPISBAIJ"
1143 int MatSetOption_MPISBAIJ(Mat A,MatOption op)
1144 {
1145   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
1146   int         ierr;
1147 
1148   PetscFunctionBegin;
1149   switch (op) {
1150   case MAT_NO_NEW_NONZERO_LOCATIONS:
1151   case MAT_YES_NEW_NONZERO_LOCATIONS:
1152   case MAT_COLUMNS_UNSORTED:
1153   case MAT_COLUMNS_SORTED:
1154   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1155   case MAT_KEEP_ZEROED_ROWS:
1156   case MAT_NEW_NONZERO_LOCATION_ERR:
1157     ierr = MatSetOption(a->A,op);CHKERRQ(ierr);
1158     ierr = MatSetOption(a->B,op);CHKERRQ(ierr);
1159     break;
1160   case MAT_ROW_ORIENTED:
1161     a->roworiented = PETSC_TRUE;
1162     ierr = MatSetOption(a->A,op);CHKERRQ(ierr);
1163     ierr = MatSetOption(a->B,op);CHKERRQ(ierr);
1164     break;
1165   case MAT_ROWS_SORTED:
1166   case MAT_ROWS_UNSORTED:
1167   case MAT_YES_NEW_DIAGONALS:
1168   case MAT_USE_HASH_TABLE:
1169   case MAT_USE_SINGLE_PRECISION_SOLVES:
1170     PetscLogInfo(A,"Info:MatSetOption_MPIBAIJ:Option ignored\n");
1171     break;
1172   case MAT_COLUMN_ORIENTED:
1173     a->roworiented = PETSC_FALSE;
1174     ierr = MatSetOption(a->A,op);CHKERRQ(ierr);
1175     ierr = MatSetOption(a->B,op);CHKERRQ(ierr);
1176     break;
1177   case MAT_IGNORE_OFF_PROC_ENTRIES:
1178     a->donotstash = PETSC_TRUE;
1179     break;
1180   case MAT_NO_NEW_DIAGONALS:
1181     SETERRQ(PETSC_ERR_SUP,"MAT_NO_NEW_DIAGONALS");
1182     break;
1183   case MAT_USE_HASH_TABLE:
1184     a->ht_flag = PETSC_TRUE;
1185     break;
1186   default:
1187     SETERRQ(PETSC_ERR_SUP,"unknown option");
1188     break;
1189   }
1190   PetscFunctionReturn(0);
1191 }
1192 
1193 #undef __FUNCT__
1194 #define __FUNCT__ "MatTranspose_MPISBAIJ("
1195 int MatTranspose_MPISBAIJ(Mat A,Mat *matout)
1196 {
1197   PetscFunctionBegin;
1198   SETERRQ(1,"Matrix is symmetric. MatTranspose() should not be called");
1199   /* PetscFunctionReturn(0); */
1200 }
1201 
1202 #undef __FUNCT__
1203 #define __FUNCT__ "MatDiagonalScale_MPISBAIJ"
1204 int MatDiagonalScale_MPISBAIJ(Mat mat,Vec ll,Vec rr)
1205 {
1206   Mat_MPISBAIJ *baij = (Mat_MPISBAIJ*)mat->data;
1207   Mat         a = baij->A,b = baij->B;
1208   int         ierr,s1,s2,s3;
1209 
1210   PetscFunctionBegin;
1211   if (ll != rr) {
1212     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"For symmetric format, left and right scaling vectors must be same\n");
1213   }
1214   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
1215   if (rr) {
1216     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
1217     if (s1!=s3) SETERRQ(PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
1218     /* Overlap communication with computation. */
1219     ierr = VecScatterBegin(rr,baij->lvec,INSERT_VALUES,SCATTER_FORWARD,baij->Mvctx);CHKERRQ(ierr);
1220     /*} if (ll) { */
1221     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
1222     if (s1!=s2) SETERRQ(PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
1223     ierr = (*b->ops->diagonalscale)(b,ll,PETSC_NULL);CHKERRQ(ierr);
1224     /* } */
1225   /* scale  the diagonal block */
1226   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
1227 
1228   /* if (rr) { */
1229     /* Do a scatter end and then right scale the off-diagonal block */
1230     ierr = VecScatterEnd(rr,baij->lvec,INSERT_VALUES,SCATTER_FORWARD,baij->Mvctx);CHKERRQ(ierr);
1231     ierr = (*b->ops->diagonalscale)(b,PETSC_NULL,baij->lvec);CHKERRQ(ierr);
1232   }
1233 
1234   PetscFunctionReturn(0);
1235 }
1236 
1237 #undef __FUNCT__
1238 #define __FUNCT__ "MatZeroRows_MPISBAIJ"
1239 int MatZeroRows_MPISBAIJ(Mat A,IS is,Scalar *diag)
1240 {
1241   Mat_MPISBAIJ   *l = (Mat_MPISBAIJ*)A->data;
1242   int            i,ierr,N,*rows,*owners = l->rowners,size = l->size;
1243   int            *procs,*nprocs,j,idx,nsends,*work,row;
1244   int            nmax,*svalues,*starts,*owner,nrecvs,rank = l->rank;
1245   int            *rvalues,tag = A->tag,count,base,slen,n,*source;
1246   int            *lens,imdex,*lrows,*values,bs=l->bs,rstart_bs=l->rstart_bs;
1247   MPI_Comm       comm = A->comm;
1248   MPI_Request    *send_waits,*recv_waits;
1249   MPI_Status     recv_status,*send_status;
1250   IS             istmp;
1251   PetscTruth     found;
1252 
1253   PetscFunctionBegin;
1254   ierr = ISGetSize(is,&N);CHKERRQ(ierr);
1255   ierr = ISGetIndices(is,&rows);CHKERRQ(ierr);
1256 
1257   /*  first count number of contributors to each processor */
1258   ierr  = PetscMalloc(2*size*sizeof(int),&nprocs);CHKERRQ(ierr);
1259   ierr  = PetscMemzero(nprocs,2*size*sizeof(int));CHKERRQ(ierr);
1260   procs = nprocs + size;
1261   ierr  = PetscMalloc((N+1)*sizeof(int),&owner);CHKERRQ(ierr); /* see note*/
1262   for (i=0; i<N; i++) {
1263     idx   = rows[i];
1264     found = PETSC_FALSE;
1265     for (j=0; j<size; j++) {
1266       if (idx >= owners[j]*bs && idx < owners[j+1]*bs) {
1267         nprocs[j]++; procs[j] = 1; owner[i] = j; found = PETSC_TRUE; break;
1268       }
1269     }
1270     if (!found) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
1271   }
1272   nsends = 0;  for (i=0; i<size; i++) { nsends += procs[i];}
1273 
1274   /* inform other processors of number of messages and max length*/
1275   ierr   = PetscMalloc(2*size*sizeof(int),&work);CHKERRQ(ierr);
1276   ierr   = MPI_Allreduce(nprocs,work,2*size,MPI_INT,PetscMaxSum_Op,comm);CHKERRQ(ierr);
1277   nmax   = work[rank];
1278   nrecvs = work[size+rank];
1279   ierr   = PetscFree(work);CHKERRQ(ierr);
1280 
1281   /* post receives:   */
1282   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(int),&rvalues);CHKERRQ(ierr);
1283   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
1284   for (i=0; i<nrecvs; i++) {
1285     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPI_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
1286   }
1287 
1288   /* do sends:
1289      1) starts[i] gives the starting index in svalues for stuff going to
1290      the ith processor
1291   */
1292   ierr = PetscMalloc((N+1)*sizeof(int),&svalues);CHKERRQ(ierr);
1293   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
1294   ierr = PetscMalloc((size+1)*sizeof(int),&starts);CHKERRQ(ierr);
1295   starts[0]  = 0;
1296   for (i=1; i<size; i++) { starts[i] = starts[i-1] + nprocs[i-1];}
1297   for (i=0; i<N; i++) {
1298     svalues[starts[owner[i]]++] = rows[i];
1299   }
1300   ierr = ISRestoreIndices(is,&rows);CHKERRQ(ierr);
1301 
1302   starts[0] = 0;
1303   for (i=1; i<size+1; i++) { starts[i] = starts[i-1] + nprocs[i-1];}
1304   count = 0;
1305   for (i=0; i<size; i++) {
1306     if (procs[i]) {
1307       ierr = MPI_Isend(svalues+starts[i],nprocs[i],MPI_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
1308     }
1309   }
1310   ierr = PetscFree(starts);CHKERRQ(ierr);
1311 
1312   base = owners[rank]*bs;
1313 
1314   /*  wait on receives */
1315   ierr   = PetscMalloc(2*(nrecvs+1)*sizeof(int),&lens);CHKERRQ(ierr);
1316   source = lens + nrecvs;
1317   count  = nrecvs; slen = 0;
1318   while (count) {
1319     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
1320     /* unpack receives into our local space */
1321     ierr = MPI_Get_count(&recv_status,MPI_INT,&n);CHKERRQ(ierr);
1322     source[imdex]  = recv_status.MPI_SOURCE;
1323     lens[imdex]    = n;
1324     slen          += n;
1325     count--;
1326   }
1327   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
1328 
1329   /* move the data into the send scatter */
1330   ierr = PetscMalloc((slen+1)*sizeof(int),&lrows);CHKERRQ(ierr);
1331   count = 0;
1332   for (i=0; i<nrecvs; i++) {
1333     values = rvalues + i*nmax;
1334     for (j=0; j<lens[i]; j++) {
1335       lrows[count++] = values[j] - base;
1336     }
1337   }
1338   ierr = PetscFree(rvalues);CHKERRQ(ierr);
1339   ierr = PetscFree(lens);CHKERRQ(ierr);
1340   ierr = PetscFree(owner);CHKERRQ(ierr);
1341   ierr = PetscFree(nprocs);CHKERRQ(ierr);
1342 
1343   /* actually zap the local rows */
1344   ierr = ISCreateGeneral(PETSC_COMM_SELF,slen,lrows,&istmp);CHKERRQ(ierr);
1345   PetscLogObjectParent(A,istmp);
1346 
1347   /*
1348         Zero the required rows. If the "diagonal block" of the matrix
1349      is square and the user wishes to set the diagonal we use seperate
1350      code so that MatSetValues() is not called for each diagonal allocating
1351      new memory, thus calling lots of mallocs and slowing things down.
1352 
1353        Contributed by: Mathew Knepley
1354   */
1355   /* must zero l->B before l->A because the (diag) case below may put values into l->B*/
1356   ierr = MatZeroRows_SeqBAIJ(l->B,istmp,0);CHKERRQ(ierr);
1357   if (diag && (l->A->M == l->A->N)) {
1358     ierr = MatZeroRows_SeqSBAIJ(l->A,istmp,diag);CHKERRQ(ierr);
1359   } else if (diag) {
1360     ierr = MatZeroRows_SeqSBAIJ(l->A,istmp,0);CHKERRQ(ierr);
1361     if (((Mat_SeqSBAIJ*)l->A->data)->nonew) {
1362       SETERRQ(PETSC_ERR_SUP,"MatZeroRows() on rectangular matrices cannot be used with the Mat options \n\
1363 MAT_NO_NEW_NONZERO_LOCATIONS,MAT_NEW_NONZERO_LOCATION_ERR,MAT_NEW_NONZERO_ALLOCATION_ERR");
1364     }
1365     for (i=0; i<slen; i++) {
1366       row  = lrows[i] + rstart_bs;
1367       ierr = MatSetValues(A,1,&row,1,&row,diag,INSERT_VALUES);CHKERRQ(ierr);
1368     }
1369     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1370     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1371   } else {
1372     ierr = MatZeroRows_SeqSBAIJ(l->A,istmp,0);CHKERRQ(ierr);
1373   }
1374 
1375   ierr = ISDestroy(istmp);CHKERRQ(ierr);
1376   ierr = PetscFree(lrows);CHKERRQ(ierr);
1377 
1378   /* wait on sends */
1379   if (nsends) {
1380     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
1381     ierr        = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
1382     ierr        = PetscFree(send_status);CHKERRQ(ierr);
1383   }
1384   ierr = PetscFree(send_waits);CHKERRQ(ierr);
1385   ierr = PetscFree(svalues);CHKERRQ(ierr);
1386 
1387   PetscFunctionReturn(0);
1388 }
1389 
1390 #undef __FUNCT__
1391 #define __FUNCT__ "MatPrintHelp_MPISBAIJ"
1392 int MatPrintHelp_MPISBAIJ(Mat A)
1393 {
1394   Mat_MPISBAIJ *a   = (Mat_MPISBAIJ*)A->data;
1395   MPI_Comm    comm = A->comm;
1396   static int  called = 0;
1397   int         ierr;
1398 
1399   PetscFunctionBegin;
1400   if (!a->rank) {
1401     ierr = MatPrintHelp_SeqSBAIJ(a->A);CHKERRQ(ierr);
1402   }
1403   if (called) {PetscFunctionReturn(0);} else called = 1;
1404   ierr = (*PetscHelpPrintf)(comm," Options for MATMPISBAIJ matrix format (the defaults):\n");CHKERRQ(ierr);
1405   ierr = (*PetscHelpPrintf)(comm,"  -mat_use_hash_table <factor>: Use hashtable for efficient matrix assembly\n");CHKERRQ(ierr);
1406   PetscFunctionReturn(0);
1407 }
1408 
1409 #undef __FUNCT__
1410 #define __FUNCT__ "MatSetUnfactored_MPISBAIJ"
1411 int MatSetUnfactored_MPISBAIJ(Mat A)
1412 {
1413   Mat_MPISBAIJ *a   = (Mat_MPISBAIJ*)A->data;
1414   int         ierr;
1415 
1416   PetscFunctionBegin;
1417   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
1418   PetscFunctionReturn(0);
1419 }
1420 
1421 static int MatDuplicate_MPISBAIJ(Mat,MatDuplicateOption,Mat *);
1422 
1423 #undef __FUNCT__
1424 #define __FUNCT__ "MatEqual_MPISBAIJ"
1425 int MatEqual_MPISBAIJ(Mat A,Mat B,PetscTruth *flag)
1426 {
1427   Mat_MPISBAIJ *matB = (Mat_MPISBAIJ*)B->data,*matA = (Mat_MPISBAIJ*)A->data;
1428   Mat         a,b,c,d;
1429   PetscTruth  flg;
1430   int         ierr;
1431 
1432   PetscFunctionBegin;
1433   ierr = PetscTypeCompare((PetscObject)B,MATMPISBAIJ,&flg);CHKERRQ(ierr);
1434   if (!flg) SETERRQ(PETSC_ERR_ARG_INCOMP,"Matrices must be same type");
1435   a = matA->A; b = matA->B;
1436   c = matB->A; d = matB->B;
1437 
1438   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
1439   if (flg == PETSC_TRUE) {
1440     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
1441   }
1442   ierr = MPI_Allreduce(&flg,flag,1,MPI_INT,MPI_LAND,A->comm);CHKERRQ(ierr);
1443   PetscFunctionReturn(0);
1444 }
1445 
1446 #undef __FUNCT__
1447 #define __FUNCT__ "MatSetUpPreallocation_MPISBAIJ"
1448 int MatSetUpPreallocation_MPISBAIJ(Mat A)
1449 {
1450   int        ierr;
1451 
1452   PetscFunctionBegin;
1453   ierr = MatMPISBAIJSetPreallocation(A,1,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
1454   PetscFunctionReturn(0);
1455 }
1456 /* -------------------------------------------------------------------*/
1457 static struct _MatOps MatOps_Values = {
1458   MatSetValues_MPISBAIJ,
1459   MatGetRow_MPISBAIJ,
1460   MatRestoreRow_MPISBAIJ,
1461   MatMult_MPISBAIJ,
1462   MatMultAdd_MPISBAIJ,
1463   MatMultTranspose_MPISBAIJ,
1464   MatMultTransposeAdd_MPISBAIJ,
1465   0,
1466   0,
1467   0,
1468   0,
1469   0,
1470   0,
1471   0,
1472   MatTranspose_MPISBAIJ,
1473   MatGetInfo_MPISBAIJ,
1474   MatEqual_MPISBAIJ,
1475   MatGetDiagonal_MPISBAIJ,
1476   MatDiagonalScale_MPISBAIJ,
1477   MatNorm_MPISBAIJ,
1478   MatAssemblyBegin_MPISBAIJ,
1479   MatAssemblyEnd_MPISBAIJ,
1480   0,
1481   MatSetOption_MPISBAIJ,
1482   MatZeroEntries_MPISBAIJ,
1483   MatZeroRows_MPISBAIJ,
1484   0,
1485   0,
1486   0,
1487   0,
1488   MatSetUpPreallocation_MPISBAIJ,
1489   0,
1490   MatGetOwnershipRange_MPISBAIJ,
1491   0,
1492   0,
1493   0,
1494   0,
1495   MatDuplicate_MPISBAIJ,
1496   0,
1497   0,
1498   0,
1499   0,
1500   0,
1501   MatGetSubMatrices_MPISBAIJ,
1502   MatIncreaseOverlap_MPISBAIJ,
1503   MatGetValues_MPISBAIJ,
1504   0,
1505   MatPrintHelp_MPISBAIJ,
1506   MatScale_MPISBAIJ,
1507   0,
1508   0,
1509   0,
1510   MatGetBlockSize_MPISBAIJ,
1511   0,
1512   0,
1513   0,
1514   0,
1515   0,
1516   0,
1517   MatSetUnfactored_MPISBAIJ,
1518   0,
1519   MatSetValuesBlocked_MPISBAIJ,
1520   0,
1521   0,
1522   0,
1523   MatGetMaps_Petsc,
1524   0,
1525   0,
1526   0,
1527   0,
1528   0,
1529   0,
1530   MatGetRowMax_MPISBAIJ};
1531 
1532 
1533 EXTERN_C_BEGIN
1534 #undef __FUNCT__
1535 #define __FUNCT__ "MatGetDiagonalBlock_MPISBAIJ"
1536 int MatGetDiagonalBlock_MPISBAIJ(Mat A,PetscTruth *iscopy,MatReuse reuse,Mat *a)
1537 {
1538   PetscFunctionBegin;
1539   *a      = ((Mat_MPISBAIJ *)A->data)->A;
1540   *iscopy = PETSC_FALSE;
1541   PetscFunctionReturn(0);
1542 }
1543 EXTERN_C_END
1544 
1545 EXTERN_C_BEGIN
1546 #undef __FUNCT__
1547 #define __FUNCT__ "MatCreate_MPISBAIJ"
1548 int MatCreate_MPISBAIJ(Mat B)
1549 {
1550   Mat_MPISBAIJ *b;
1551   int          ierr;
1552   PetscTruth   flg;
1553 
1554   PetscFunctionBegin;
1555 
1556   ierr    = PetscNew(Mat_MPISBAIJ,&b);CHKERRQ(ierr);
1557   B->data = (void*)b;
1558   ierr    = PetscMemzero(b,sizeof(Mat_MPISBAIJ));CHKERRQ(ierr);
1559   ierr    = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
1560 
1561   B->ops->destroy    = MatDestroy_MPISBAIJ;
1562   B->ops->view       = MatView_MPISBAIJ;
1563   B->mapping    = 0;
1564   B->factor     = 0;
1565   B->assembled  = PETSC_FALSE;
1566 
1567   B->insertmode = NOT_SET_VALUES;
1568   ierr = MPI_Comm_rank(B->comm,&b->rank);CHKERRQ(ierr);
1569   ierr = MPI_Comm_size(B->comm,&b->size);CHKERRQ(ierr);
1570 
1571   /* build local table of row and column ownerships */
1572   ierr          = PetscMalloc(3*(b->size+2)*sizeof(int),&b->rowners);CHKERRQ(ierr);
1573   b->cowners    = b->rowners + b->size + 2;
1574   b->rowners_bs = b->cowners + b->size + 2;
1575   PetscLogObjectMemory(B,3*(b->size+2)*sizeof(int)+sizeof(struct _p_Mat)+sizeof(Mat_MPISBAIJ));
1576 
1577   /* build cache for off array entries formed */
1578   ierr = MatStashCreate_Private(B->comm,1,&B->stash);CHKERRQ(ierr);
1579   b->donotstash  = PETSC_FALSE;
1580   b->colmap      = PETSC_NULL;
1581   b->garray      = PETSC_NULL;
1582   b->roworiented = PETSC_TRUE;
1583 
1584 #if defined(PETSC_USE_MAT_SINGLE)
1585   /* stuff for MatSetValues_XXX in single precision */
1586   b->setvalueslen     = 0;
1587   b->setvaluescopy    = PETSC_NULL;
1588 #endif
1589 
1590   /* stuff used in block assembly */
1591   b->barray       = 0;
1592 
1593   /* stuff used for matrix vector multiply */
1594   b->lvec         = 0;
1595   b->Mvctx        = 0;
1596 
1597   /* stuff for MatGetRow() */
1598   b->rowindices   = 0;
1599   b->rowvalues    = 0;
1600   b->getrowactive = PETSC_FALSE;
1601 
1602   /* hash table stuff */
1603   b->ht           = 0;
1604   b->hd           = 0;
1605   b->ht_size      = 0;
1606   b->ht_flag      = PETSC_FALSE;
1607   b->ht_fact      = 0;
1608   b->ht_total_ct  = 0;
1609   b->ht_insert_ct = 0;
1610 
1611   ierr = PetscOptionsHasName(PETSC_NULL,"-mat_use_hash_table",&flg);CHKERRQ(ierr);
1612   if (flg) {
1613     double fact = 1.39;
1614     ierr = MatSetOption(B,MAT_USE_HASH_TABLE);CHKERRQ(ierr);
1615     ierr = PetscOptionsGetDouble(PETSC_NULL,"-mat_use_hash_table",&fact,PETSC_NULL);CHKERRQ(ierr);
1616     if (fact <= 1.0) fact = 1.39;
1617     ierr = MatMPIBAIJSetHashTableFactor(B,fact);CHKERRQ(ierr);
1618     PetscLogInfo(0,"MatCreateMPISBAIJ:Hash table Factor used %5.2f\n",fact);
1619   }
1620   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatStoreValues_C",
1621                                      "MatStoreValues_MPISBAIJ",
1622                                      MatStoreValues_MPISBAIJ);CHKERRQ(ierr);
1623   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatRetrieveValues_C",
1624                                      "MatRetrieveValues_MPISBAIJ",
1625                                      MatRetrieveValues_MPISBAIJ);CHKERRQ(ierr);
1626   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetDiagonalBlock_C",
1627                                      "MatGetDiagonalBlock_MPISBAIJ",
1628                                      MatGetDiagonalBlock_MPISBAIJ);CHKERRQ(ierr);
1629   PetscFunctionReturn(0);
1630 }
1631 EXTERN_C_END
1632 
1633 #undef __FUNCT__
1634 #define __FUNCT__ "MatMPISBAIJSetPreallocation"
1635 /*@C
1636    MatMPISBAIJSetPreallocation - For good matrix assembly performance
1637    the user should preallocate the matrix storage by setting the parameters
1638    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
1639    performance can be increased by more than a factor of 50.
1640 
1641    Collective on Mat
1642 
1643    Input Parameters:
1644 +  A - the matrix
1645 .  bs   - size of blockk
1646 .  d_nz  - number of block nonzeros per block row in diagonal portion of local
1647            submatrix  (same for all local rows)
1648 .  d_nnz - array containing the number of block nonzeros in the various block rows
1649            of the in diagonal portion of the local (possibly different for each block
1650            row) or PETSC_NULL.  You must leave room for the diagonal entry even if it is zero.
1651 .  o_nz  - number of block nonzeros per block row in the off-diagonal portion of local
1652            submatrix (same for all local rows).
1653 -  o_nnz - array containing the number of nonzeros in the various block rows of the
1654            off-diagonal portion of the local submatrix (possibly different for
1655            each block row) or PETSC_NULL.
1656 
1657 
1658    Options Database Keys:
1659 .   -mat_no_unroll - uses code that does not unroll the loops in the
1660                      block calculations (much slower)
1661 .   -mat_block_size - size of the blocks to use
1662 
1663    Notes:
1664 
1665    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one processor
1666    than it must be used on all processors that share the object for that argument.
1667 
1668    Storage Information:
1669    For a square global matrix we define each processor's diagonal portion
1670    to be its local rows and the corresponding columns (a square submatrix);
1671    each processor's off-diagonal portion encompasses the remainder of the
1672    local matrix (a rectangular submatrix).
1673 
1674    The user can specify preallocated storage for the diagonal part of
1675    the local submatrix with either d_nz or d_nnz (not both).  Set
1676    d_nz=PETSC_DEFAULT and d_nnz=PETSC_NULL for PETSc to control dynamic
1677    memory allocation.  Likewise, specify preallocated storage for the
1678    off-diagonal part of the local submatrix with o_nz or o_nnz (not both).
1679 
1680    Consider a processor that owns rows 3, 4 and 5 of a parallel matrix. In
1681    the figure below we depict these three local rows and all columns (0-11).
1682 
1683 .vb
1684            0 1 2 3 4 5 6 7 8 9 10 11
1685           -------------------
1686    row 3  |  o o o d d d o o o o o o
1687    row 4  |  o o o d d d o o o o o o
1688    row 5  |  o o o d d d o o o o o o
1689           -------------------
1690 .ve
1691 
1692    Thus, any entries in the d locations are stored in the d (diagonal)
1693    submatrix, and any entries in the o locations are stored in the
1694    o (off-diagonal) submatrix.  Note that the d and the o submatrices are
1695    stored simply in the MATSEQBAIJ format for compressed row storage.
1696 
1697    Now d_nz should indicate the number of block nonzeros per row in the d matrix,
1698    and o_nz should indicate the number of block nonzeros per row in the o matrix.
1699    In general, for PDE problems in which most nonzeros are near the diagonal,
1700    one expects d_nz >> o_nz.   For large problems you MUST preallocate memory
1701    or you will get TERRIBLE performance; see the users' manual chapter on
1702    matrices.
1703 
1704    Level: intermediate
1705 
1706 .keywords: matrix, block, aij, compressed row, sparse, parallel
1707 
1708 .seealso: MatCreate(), MatCreateSeqSBAIJ(), MatSetValues(), MatCreateMPIBAIJ()
1709 @*/
1710 
1711 int MatMPISBAIJSetPreallocation(Mat B,int bs,int d_nz,int *d_nnz,int o_nz,int *o_nnz)
1712 {
1713   Mat_MPISBAIJ *b;
1714   int          ierr,i,mbs,Mbs;
1715   PetscTruth   flg2;
1716 
1717   PetscFunctionBegin;
1718   ierr = PetscTypeCompare((PetscObject)B,MATMPISBAIJ,&flg2);CHKERRQ(ierr);
1719   if (!flg2) PetscFunctionReturn(0);
1720 
1721   ierr = PetscOptionsGetInt(PETSC_NULL,"-mat_block_size",&bs,PETSC_NULL);CHKERRQ(ierr);
1722 
1723   if (bs < 1) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Invalid block size specified, must be positive");
1724   if (d_nz == PETSC_DECIDE || d_nz == PETSC_DEFAULT) d_nz = 3;
1725   if (o_nz == PETSC_DECIDE || o_nz == PETSC_DEFAULT) o_nz = 1;
1726   if (d_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"d_nz cannot be less than 0: value %d",d_nz);
1727   if (o_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"o_nz cannot be less than 0: value %d",o_nz);
1728   if (d_nnz) {
1729     for (i=0; i<B->m/bs; i++) {
1730       if (d_nnz[i] < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"d_nnz cannot be less than -1: local row %d value %d",i,d_nnz[i]);
1731     }
1732   }
1733   if (o_nnz) {
1734     for (i=0; i<B->m/bs; i++) {
1735       if (o_nnz[i] < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"o_nnz cannot be less than -1: local row %d value %d",i,o_nnz[i]);
1736     }
1737   }
1738   B->preallocated = PETSC_TRUE;
1739   ierr = PetscSplitOwnershipBlock(B->comm,bs,&B->m,&B->M);CHKERRQ(ierr);
1740   ierr = PetscSplitOwnershipBlock(B->comm,bs,&B->n,&B->N);CHKERRQ(ierr);
1741   ierr = MapCreateMPI(B->comm,B->m,B->M,&B->rmap);CHKERRQ(ierr);
1742   ierr = MapCreateMPI(B->comm,B->m,B->M,&B->cmap);CHKERRQ(ierr);
1743 
1744   b   = (Mat_MPISBAIJ*)B->data;
1745   mbs = B->m/bs;
1746   Mbs = B->M/bs;
1747   if (mbs*bs != B->m) {
1748     SETERRQ2(PETSC_ERR_ARG_SIZ,"No of local rows %d must be divisible by blocksize %d",B->m,bs);
1749   }
1750 
1751   b->bs  = bs;
1752   b->bs2 = bs*bs;
1753   b->mbs = mbs;
1754   b->nbs = mbs;
1755   b->Mbs = Mbs;
1756   b->Nbs = Mbs;
1757 
1758   ierr = MPI_Allgather(&b->mbs,1,MPI_INT,b->rowners+1,1,MPI_INT,B->comm);CHKERRQ(ierr);
1759   b->rowners[0]    = 0;
1760   for (i=2; i<=b->size; i++) {
1761     b->rowners[i] += b->rowners[i-1];
1762   }
1763   b->rstart    = b->rowners[b->rank];
1764   b->rend      = b->rowners[b->rank+1];
1765   b->cstart    = b->rstart;
1766   b->cend      = b->rend;
1767   for (i=0; i<=b->size; i++) {
1768     b->rowners_bs[i] = b->rowners[i]*bs;
1769   }
1770   b->rstart_bs = b-> rstart*bs;
1771   b->rend_bs   = b->rend*bs;
1772 
1773   b->cstart_bs = b->cstart*bs;
1774   b->cend_bs   = b->cend*bs;
1775 
1776 
1777   ierr = MatCreateSeqSBAIJ(PETSC_COMM_SELF,bs,B->m,B->m,d_nz,d_nnz,&b->A);CHKERRQ(ierr);
1778   PetscLogObjectParent(B,b->A);
1779   ierr = MatCreateSeqBAIJ(PETSC_COMM_SELF,bs,B->m,B->M,o_nz,o_nnz,&b->B);CHKERRQ(ierr);
1780   PetscLogObjectParent(B,b->B);
1781 
1782   /* build cache for off array entries formed */
1783   ierr = MatStashCreate_Private(B->comm,bs,&B->bstash);CHKERRQ(ierr);
1784 
1785   PetscFunctionReturn(0);
1786 }
1787 
1788 #undef __FUNCT__
1789 #define __FUNCT__ "MatCreateMPISBAIJ"
1790 /*@C
1791    MatCreateMPISBAIJ - Creates a sparse parallel matrix in symmetric block AIJ format
1792    (block compressed row).  For good matrix assembly performance
1793    the user should preallocate the matrix storage by setting the parameters
1794    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
1795    performance can be increased by more than a factor of 50.
1796 
1797    Collective on MPI_Comm
1798 
1799    Input Parameters:
1800 +  comm - MPI communicator
1801 .  bs   - size of blockk
1802 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
1803            This value should be the same as the local size used in creating the
1804            y vector for the matrix-vector product y = Ax.
1805 .  n - number of local columns (or PETSC_DECIDE to have calculated if N is given)
1806            This value should be the same as the local size used in creating the
1807            x vector for the matrix-vector product y = Ax.
1808 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
1809 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
1810 .  d_nz  - number of block nonzeros per block row in diagonal portion of local
1811            submatrix  (same for all local rows)
1812 .  d_nnz - array containing the number of block nonzeros in the various block rows
1813            of the in diagonal portion of the local (possibly different for each block
1814            row) or PETSC_NULL.  You must leave room for the diagonal entry even if it is zero.
1815 .  o_nz  - number of block nonzeros per block row in the off-diagonal portion of local
1816            submatrix (same for all local rows).
1817 -  o_nnz - array containing the number of nonzeros in the various block rows of the
1818            off-diagonal portion of the local submatrix (possibly different for
1819            each block row) or PETSC_NULL.
1820 
1821    Output Parameter:
1822 .  A - the matrix
1823 
1824    Options Database Keys:
1825 .   -mat_no_unroll - uses code that does not unroll the loops in the
1826                      block calculations (much slower)
1827 .   -mat_block_size - size of the blocks to use
1828 .   -mat_mpi - use the parallel matrix data structures even on one processor
1829                (defaults to using SeqBAIJ format on one processor)
1830 
1831    Notes:
1832    The user MUST specify either the local or global matrix dimensions
1833    (possibly both).
1834 
1835    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one processor
1836    than it must be used on all processors that share the object for that argument.
1837 
1838    Storage Information:
1839    For a square global matrix we define each processor's diagonal portion
1840    to be its local rows and the corresponding columns (a square submatrix);
1841    each processor's off-diagonal portion encompasses the remainder of the
1842    local matrix (a rectangular submatrix).
1843 
1844    The user can specify preallocated storage for the diagonal part of
1845    the local submatrix with either d_nz or d_nnz (not both).  Set
1846    d_nz=PETSC_DEFAULT and d_nnz=PETSC_NULL for PETSc to control dynamic
1847    memory allocation.  Likewise, specify preallocated storage for the
1848    off-diagonal part of the local submatrix with o_nz or o_nnz (not both).
1849 
1850    Consider a processor that owns rows 3, 4 and 5 of a parallel matrix. In
1851    the figure below we depict these three local rows and all columns (0-11).
1852 
1853 .vb
1854            0 1 2 3 4 5 6 7 8 9 10 11
1855           -------------------
1856    row 3  |  o o o d d d o o o o o o
1857    row 4  |  o o o d d d o o o o o o
1858    row 5  |  o o o d d d o o o o o o
1859           -------------------
1860 .ve
1861 
1862    Thus, any entries in the d locations are stored in the d (diagonal)
1863    submatrix, and any entries in the o locations are stored in the
1864    o (off-diagonal) submatrix.  Note that the d and the o submatrices are
1865    stored simply in the MATSEQBAIJ format for compressed row storage.
1866 
1867    Now d_nz should indicate the number of block nonzeros per row in the d matrix,
1868    and o_nz should indicate the number of block nonzeros per row in the o matrix.
1869    In general, for PDE problems in which most nonzeros are near the diagonal,
1870    one expects d_nz >> o_nz.   For large problems you MUST preallocate memory
1871    or you will get TERRIBLE performance; see the users' manual chapter on
1872    matrices.
1873 
1874    Level: intermediate
1875 
1876 .keywords: matrix, block, aij, compressed row, sparse, parallel
1877 
1878 .seealso: MatCreate(), MatCreateSeqSBAIJ(), MatSetValues(), MatCreateMPIBAIJ()
1879 @*/
1880 
1881 int MatCreateMPISBAIJ(MPI_Comm comm,int bs,int m,int n,int M,int N,int d_nz,int *d_nnz,int o_nz,int *o_nnz,Mat *A)
1882 {
1883   int ierr,size;
1884 
1885   PetscFunctionBegin;
1886   ierr = MatCreate(comm,m,n,M,N,A);CHKERRQ(ierr);
1887   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1888   if (size > 1) {
1889     ierr = MatSetType(*A,MATMPISBAIJ);CHKERRQ(ierr);
1890     ierr = MatMPISBAIJSetPreallocation(*A,bs,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
1891   } else {
1892     ierr = MatSetType(*A,MATSEQSBAIJ);CHKERRQ(ierr);
1893     ierr = MatSeqSBAIJSetPreallocation(*A,bs,d_nz,d_nnz);CHKERRQ(ierr);
1894   }
1895   PetscFunctionReturn(0);
1896 }
1897 
1898 
1899 #undef __FUNCT__
1900 #define __FUNCT__ "MatDuplicate_MPISBAIJ"
1901 static int MatDuplicate_MPISBAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
1902 {
1903   Mat          mat;
1904   Mat_MPISBAIJ *a,*oldmat = (Mat_MPISBAIJ*)matin->data;
1905   int          ierr,len=0;
1906 
1907   PetscFunctionBegin;
1908   *newmat       = 0;
1909   ierr = MatCreate(matin->comm,matin->m,matin->n,matin->M,matin->N,&mat);CHKERRQ(ierr);
1910   ierr = MatSetType(mat,MATMPISBAIJ);CHKERRQ(ierr);
1911   mat->preallocated = PETSC_TRUE;
1912   a = (Mat_MPISBAIJ*)mat->data;
1913   a->bs  = oldmat->bs;
1914   a->bs2 = oldmat->bs2;
1915   a->mbs = oldmat->mbs;
1916   a->nbs = oldmat->nbs;
1917   a->Mbs = oldmat->Mbs;
1918   a->Nbs = oldmat->Nbs;
1919 
1920   a->rstart       = oldmat->rstart;
1921   a->rend         = oldmat->rend;
1922   a->cstart       = oldmat->cstart;
1923   a->cend         = oldmat->cend;
1924   a->size         = oldmat->size;
1925   a->rank         = oldmat->rank;
1926   a->donotstash   = oldmat->donotstash;
1927   a->roworiented  = oldmat->roworiented;
1928   a->rowindices   = 0;
1929   a->rowvalues    = 0;
1930   a->getrowactive = PETSC_FALSE;
1931   a->barray       = 0;
1932   a->rstart_bs    = oldmat->rstart_bs;
1933   a->rend_bs      = oldmat->rend_bs;
1934   a->cstart_bs    = oldmat->cstart_bs;
1935   a->cend_bs      = oldmat->cend_bs;
1936 
1937   /* hash table stuff */
1938   a->ht           = 0;
1939   a->hd           = 0;
1940   a->ht_size      = 0;
1941   a->ht_flag      = oldmat->ht_flag;
1942   a->ht_fact      = oldmat->ht_fact;
1943   a->ht_total_ct  = 0;
1944   a->ht_insert_ct = 0;
1945 
1946   ierr = PetscMalloc(3*(a->size+2)*sizeof(int),&a->rowners);CHKERRQ(ierr);
1947   PetscLogObjectMemory(mat,3*(a->size+2)*sizeof(int)+sizeof(struct _p_Mat)+sizeof(Mat_MPISBAIJ));
1948   a->cowners    = a->rowners + a->size + 2;
1949   a->rowners_bs = a->cowners + a->size + 2;
1950   ierr = PetscMemcpy(a->rowners,oldmat->rowners,3*(a->size+2)*sizeof(int));CHKERRQ(ierr);
1951   ierr = MatStashCreate_Private(matin->comm,1,&mat->stash);CHKERRQ(ierr);
1952   ierr = MatStashCreate_Private(matin->comm,oldmat->bs,&mat->bstash);CHKERRQ(ierr);
1953   if (oldmat->colmap) {
1954 #if defined (PETSC_USE_CTABLE)
1955     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
1956 #else
1957     ierr = PetscMalloc((a->Nbs)*sizeof(int),&a->colmap);CHKERRQ(ierr);
1958     PetscLogObjectMemory(mat,(a->Nbs)*sizeof(int));
1959     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(a->Nbs)*sizeof(int));CHKERRQ(ierr);
1960 #endif
1961   } else a->colmap = 0;
1962   if (oldmat->garray && (len = ((Mat_SeqBAIJ*)(oldmat->B->data))->nbs)) {
1963     ierr = PetscMalloc(len*sizeof(int),&a->garray);CHKERRQ(ierr);
1964     PetscLogObjectMemory(mat,len*sizeof(int));
1965     ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(int));CHKERRQ(ierr);
1966   } else a->garray = 0;
1967 
1968   ierr =  VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
1969   PetscLogObjectParent(mat,a->lvec);
1970   ierr =  VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
1971 
1972   PetscLogObjectParent(mat,a->Mvctx);
1973   ierr =  MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
1974   PetscLogObjectParent(mat,a->A);
1975   ierr =  MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
1976   PetscLogObjectParent(mat,a->B);
1977   ierr = PetscFListDuplicate(mat->qlist,&matin->qlist);CHKERRQ(ierr);
1978   *newmat = mat;
1979   PetscFunctionReturn(0);
1980 }
1981 
1982 #include "petscsys.h"
1983 
1984 EXTERN_C_BEGIN
1985 #undef __FUNCT__
1986 #define __FUNCT__ "MatLoad_MPISBAIJ"
1987 int MatLoad_MPISBAIJ(PetscViewer viewer,MatType type,Mat *newmat)
1988 {
1989   Mat          A;
1990   int          i,nz,ierr,j,rstart,rend,fd;
1991   Scalar       *vals,*buf;
1992   MPI_Comm     comm = ((PetscObject)viewer)->comm;
1993   MPI_Status   status;
1994   int          header[4],rank,size,*rowlengths = 0,M,N,m,*rowners,*browners,maxnz,*cols;
1995   int          *locrowlens,*sndcounts = 0,*procsnz = 0,jj,*mycols,*ibuf;
1996   int          tag = ((PetscObject)viewer)->tag,bs=1,Mbs,mbs,extra_rows;
1997   int          *dlens,*odlens,*mask,*masked1,*masked2,rowcount,odcount;
1998   int          dcount,kmax,k,nzcount,tmp;
1999 
2000   PetscFunctionBegin;
2001   ierr = PetscOptionsGetInt(PETSC_NULL,"-matload_block_size",&bs,PETSC_NULL);CHKERRQ(ierr);
2002 
2003   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2004   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2005   if (!rank) {
2006     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
2007     ierr = PetscBinaryRead(fd,(char *)header,4,PETSC_INT);CHKERRQ(ierr);
2008     if (header[0] != MAT_COOKIE) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
2009     if (header[3] < 0) {
2010       SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"Matrix stored in special format, cannot load as MPISBAIJ");
2011     }
2012   }
2013 
2014   ierr = MPI_Bcast(header+1,3,MPI_INT,0,comm);CHKERRQ(ierr);
2015   M = header[1]; N = header[2];
2016 
2017   if (M != N) SETERRQ(PETSC_ERR_SUP,"Can only do square matrices");
2018 
2019   /*
2020      This code adds extra rows to make sure the number of rows is
2021      divisible by the blocksize
2022   */
2023   Mbs        = M/bs;
2024   extra_rows = bs - M + bs*(Mbs);
2025   if (extra_rows == bs) extra_rows = 0;
2026   else                  Mbs++;
2027   if (extra_rows &&!rank) {
2028     PetscLogInfo(0,"MatLoad_MPISBAIJ:Padding loaded matrix to match blocksize\n");
2029   }
2030 
2031   /* determine ownership of all rows */
2032   mbs        = Mbs/size + ((Mbs % size) > rank);
2033   m          = mbs*bs;
2034   ierr       = PetscMalloc(2*(size+2)*sizeof(int),&rowners);CHKERRQ(ierr);
2035   browners   = rowners + size + 1;
2036   ierr       = MPI_Allgather(&mbs,1,MPI_INT,rowners+1,1,MPI_INT,comm);CHKERRQ(ierr);
2037   rowners[0] = 0;
2038   for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
2039   for (i=0; i<=size;  i++) browners[i] = rowners[i]*bs;
2040   rstart = rowners[rank];
2041   rend   = rowners[rank+1];
2042 
2043   /* distribute row lengths to all processors */
2044   ierr = PetscMalloc((rend-rstart)*bs*sizeof(int),&locrowlens);CHKERRQ(ierr);
2045   if (!rank) {
2046     ierr = PetscMalloc((M+extra_rows)*sizeof(int),&rowlengths);CHKERRQ(ierr);
2047     ierr = PetscBinaryRead(fd,rowlengths,M,PETSC_INT);CHKERRQ(ierr);
2048     for (i=0; i<extra_rows; i++) rowlengths[M+i] = 1;
2049     ierr = PetscMalloc(size*sizeof(int),&sndcounts);CHKERRQ(ierr);
2050     for (i=0; i<size; i++) sndcounts[i] = browners[i+1] - browners[i];
2051     ierr = MPI_Scatterv(rowlengths,sndcounts,browners,MPI_INT,locrowlens,(rend-rstart)*bs,MPI_INT,0,comm);CHKERRQ(ierr);
2052     ierr = PetscFree(sndcounts);CHKERRQ(ierr);
2053   } else {
2054     ierr = MPI_Scatterv(0,0,0,MPI_INT,locrowlens,(rend-rstart)*bs,MPI_INT,0,comm);CHKERRQ(ierr);
2055   }
2056 
2057   if (!rank) {   /* procs[0] */
2058     /* calculate the number of nonzeros on each processor */
2059     ierr = PetscMalloc(size*sizeof(int),&procsnz);CHKERRQ(ierr);
2060     ierr = PetscMemzero(procsnz,size*sizeof(int));CHKERRQ(ierr);
2061     for (i=0; i<size; i++) {
2062       for (j=rowners[i]*bs; j< rowners[i+1]*bs; j++) {
2063         procsnz[i] += rowlengths[j];
2064       }
2065     }
2066     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
2067 
2068     /* determine max buffer needed and allocate it */
2069     maxnz = 0;
2070     for (i=0; i<size; i++) {
2071       maxnz = PetscMax(maxnz,procsnz[i]);
2072     }
2073     ierr = PetscMalloc(maxnz*sizeof(int),&cols);CHKERRQ(ierr);
2074 
2075     /* read in my part of the matrix column indices  */
2076     nz     = procsnz[0];
2077     ierr   = PetscMalloc(nz*sizeof(int),&ibuf);CHKERRQ(ierr);
2078     mycols = ibuf;
2079     if (size == 1)  nz -= extra_rows;
2080     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
2081     if (size == 1)  for (i=0; i< extra_rows; i++) { mycols[nz+i] = M+i; }
2082 
2083     /* read in every ones (except the last) and ship off */
2084     for (i=1; i<size-1; i++) {
2085       nz   = procsnz[i];
2086       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2087       ierr = MPI_Send(cols,nz,MPI_INT,i,tag,comm);CHKERRQ(ierr);
2088     }
2089     /* read in the stuff for the last proc */
2090     if (size != 1) {
2091       nz   = procsnz[size-1] - extra_rows;  /* the extra rows are not on the disk */
2092       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2093       for (i=0; i<extra_rows; i++) cols[nz+i] = M+i;
2094       ierr = MPI_Send(cols,nz+extra_rows,MPI_INT,size-1,tag,comm);CHKERRQ(ierr);
2095     }
2096     ierr = PetscFree(cols);CHKERRQ(ierr);
2097   } else {  /* procs[i], i>0 */
2098     /* determine buffer space needed for message */
2099     nz = 0;
2100     for (i=0; i<m; i++) {
2101       nz += locrowlens[i];
2102     }
2103     ierr   = PetscMalloc(nz*sizeof(int),&ibuf);CHKERRQ(ierr);
2104     mycols = ibuf;
2105     /* receive message of column indices*/
2106     ierr = MPI_Recv(mycols,nz,MPI_INT,0,tag,comm,&status);CHKERRQ(ierr);
2107     ierr = MPI_Get_count(&status,MPI_INT,&maxnz);CHKERRQ(ierr);
2108     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file");
2109   }
2110 
2111   /* loop over local rows, determining number of off diagonal entries */
2112   ierr     = PetscMalloc(2*(rend-rstart+1)*sizeof(int),&dlens);CHKERRQ(ierr);
2113   odlens   = dlens + (rend-rstart);
2114   ierr     = PetscMalloc(3*Mbs*sizeof(int),&mask);CHKERRQ(ierr);
2115   ierr     = PetscMemzero(mask,3*Mbs*sizeof(int));CHKERRQ(ierr);
2116   masked1  = mask    + Mbs;
2117   masked2  = masked1 + Mbs;
2118   rowcount = 0; nzcount = 0;
2119   for (i=0; i<mbs; i++) {
2120     dcount  = 0;
2121     odcount = 0;
2122     for (j=0; j<bs; j++) {
2123       kmax = locrowlens[rowcount];
2124       for (k=0; k<kmax; k++) {
2125         tmp = mycols[nzcount++]/bs; /* block col. index */
2126         if (!mask[tmp]) {
2127           mask[tmp] = 1;
2128           if (tmp < rstart || tmp >= rend) masked2[odcount++] = tmp; /* entry in off-diag portion */
2129           else masked1[dcount++] = tmp; /* entry in diag portion */
2130         }
2131       }
2132       rowcount++;
2133     }
2134 
2135     dlens[i]  = dcount;  /* d_nzz[i] */
2136     odlens[i] = odcount; /* o_nzz[i] */
2137 
2138     /* zero out the mask elements we set */
2139     for (j=0; j<dcount; j++) mask[masked1[j]] = 0;
2140     for (j=0; j<odcount; j++) mask[masked2[j]] = 0;
2141   }
2142 
2143   /* create our matrix */
2144   ierr = MatCreateMPISBAIJ(comm,bs,m,m,PETSC_DETERMINE,PETSC_DETERMINE,0,dlens,0,odlens,newmat);
2145   CHKERRQ(ierr);
2146   A = *newmat;
2147   ierr = MatSetOption(A,MAT_COLUMNS_SORTED);CHKERRQ(ierr);
2148 
2149   if (!rank) {
2150     ierr = PetscMalloc(maxnz*sizeof(Scalar),&buf);CHKERRQ(ierr);
2151     /* read in my part of the matrix numerical values  */
2152     nz = procsnz[0];
2153     vals = buf;
2154     mycols = ibuf;
2155     if (size == 1)  nz -= extra_rows;
2156     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2157     if (size == 1)  for (i=0; i< extra_rows; i++) { vals[nz+i] = 1.0; }
2158 
2159     /* insert into matrix */
2160     jj      = rstart*bs;
2161     for (i=0; i<m; i++) {
2162       ierr = MatSetValues(A,1,&jj,locrowlens[i],mycols,vals,INSERT_VALUES);CHKERRQ(ierr);
2163       mycols += locrowlens[i];
2164       vals   += locrowlens[i];
2165       jj++;
2166     }
2167 
2168     /* read in other processors (except the last one) and ship out */
2169     for (i=1; i<size-1; i++) {
2170       nz   = procsnz[i];
2171       vals = buf;
2172       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2173       ierr = MPI_Send(vals,nz,MPIU_SCALAR,i,A->tag,comm);CHKERRQ(ierr);
2174     }
2175     /* the last proc */
2176     if (size != 1){
2177       nz   = procsnz[i] - extra_rows;
2178       vals = buf;
2179       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2180       for (i=0; i<extra_rows; i++) vals[nz+i] = 1.0;
2181       ierr = MPI_Send(vals,nz+extra_rows,MPIU_SCALAR,size-1,A->tag,comm);CHKERRQ(ierr);
2182     }
2183     ierr = PetscFree(procsnz);CHKERRQ(ierr);
2184 
2185   } else {
2186     /* receive numeric values */
2187     ierr = PetscMalloc(nz*sizeof(Scalar),&buf);CHKERRQ(ierr);
2188 
2189     /* receive message of values*/
2190     vals   = buf;
2191     mycols = ibuf;
2192     ierr   = MPI_Recv(vals,nz,MPIU_SCALAR,0,A->tag,comm,&status);CHKERRQ(ierr);
2193     ierr   = MPI_Get_count(&status,MPIU_SCALAR,&maxnz);CHKERRQ(ierr);
2194     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file");
2195 
2196     /* insert into matrix */
2197     jj      = rstart*bs;
2198     for (i=0; i<m; i++) {
2199       ierr    = MatSetValues_MPISBAIJ(A,1,&jj,locrowlens[i],mycols,vals,INSERT_VALUES);CHKERRQ(ierr);
2200       mycols += locrowlens[i];
2201       vals   += locrowlens[i];
2202       jj++;
2203     }
2204   }
2205 
2206   ierr = PetscFree(locrowlens);CHKERRQ(ierr);
2207   ierr = PetscFree(buf);CHKERRQ(ierr);
2208   ierr = PetscFree(ibuf);CHKERRQ(ierr);
2209   ierr = PetscFree(rowners);CHKERRQ(ierr);
2210   ierr = PetscFree(dlens);CHKERRQ(ierr);
2211   ierr = PetscFree(mask);CHKERRQ(ierr);
2212   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2213   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2214   PetscFunctionReturn(0);
2215 }
2216 EXTERN_C_END
2217 
2218 #undef __FUNCT__
2219 #define __FUNCT__ "MatMPISBAIJSetHashTableFactor"
2220 /*@
2221    MatMPISBAIJSetHashTableFactor - Sets the factor required to compute the size of the HashTable.
2222 
2223    Input Parameters:
2224 .  mat  - the matrix
2225 .  fact - factor
2226 
2227    Collective on Mat
2228 
2229    Level: advanced
2230 
2231   Notes:
2232    This can also be set by the command line option: -mat_use_hash_table fact
2233 
2234 .keywords: matrix, hashtable, factor, HT
2235 
2236 .seealso: MatSetOption()
2237 @*/
2238 int MatMPISBAIJSetHashTableFactor(Mat mat,PetscReal fact)
2239 {
2240   PetscFunctionBegin;
2241   SETERRQ(1,"Function not yet written for SBAIJ format");
2242   /* PetscFunctionReturn(0); */
2243 }
2244 
2245 #undef __FUNCT__
2246 #define __FUNCT__ "MatGetRowMax_MPISBAIJ"
2247 int MatGetRowMax_MPISBAIJ(Mat A,Vec v)
2248 {
2249   Mat_MPISBAIJ *a = (Mat_MPISBAIJ*)A->data;
2250   Mat_SeqBAIJ  *b = (Mat_SeqBAIJ*)(a->B)->data;
2251   PetscReal    atmp;
2252   double       *work,*svalues,*rvalues;
2253   int          ierr,i,bs,mbs,*bi,*bj,brow,j,ncols,krow,kcol,col,row,Mbs,bcol;
2254   int          rank,size,*rowners_bs,dest,count,source;
2255   Scalar       *va;
2256   MatScalar    *ba;
2257   MPI_Status   stat;
2258 
2259   PetscFunctionBegin;
2260   ierr = MatGetRowMax(a->A,v);CHKERRQ(ierr);
2261   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2262 
2263   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
2264   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
2265 
2266   bs   = a->bs;
2267   mbs  = a->mbs;
2268   Mbs  = a->Mbs;
2269   ba   = b->a;
2270   bi   = b->i;
2271   bj   = b->j;
2272   /*
2273   PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d] M: %d, bs: %d, mbs: %d \n",rank,bs*Mbs,bs,mbs);
2274   PetscSynchronizedFlush(PETSC_COMM_WORLD);
2275   */
2276 
2277   /* find ownerships */
2278   rowners_bs = a->rowners_bs;
2279   /*
2280   if (!rank){
2281     for (i=0; i<size+1; i++) PetscPrintf(PETSC_COMM_SELF," rowners_bs[%d]: %d\n",i,rowners_bs[i]);
2282   }
2283   */
2284 
2285   /* each proc creates an array to be distributed */
2286   ierr = PetscMalloc(bs*Mbs*sizeof(PetscReal),&work);CHKERRQ(ierr);
2287   ierr = PetscMemzero(work,bs*Mbs*sizeof(PetscReal));CHKERRQ(ierr);
2288 
2289   /* row_max for B */
2290   if (rank != size-1){
2291     for (i=0; i<mbs; i++) {
2292       ncols = bi[1] - bi[0]; bi++;
2293       brow  = bs*i;
2294       for (j=0; j<ncols; j++){
2295         bcol = bs*(*bj);
2296         for (kcol=0; kcol<bs; kcol++){
2297           col = bcol + kcol;                 /* local col index */
2298           col += rowners_bs[rank+1];      /* global col index */
2299           /* PetscPrintf(PETSC_COMM_SELF,"[%d], col: %d\n",rank,col); */
2300           for (krow=0; krow<bs; krow++){
2301             atmp = PetscAbsScalar(*ba); ba++;
2302             row = brow + krow;    /* local row index */
2303             /* printf("val[%d,%d]: %g\n",row,col,atmp); */
2304             if (PetscRealPart(va[row]) < atmp) va[row] = atmp;
2305             if (work[col] < atmp) work[col] = atmp;
2306           }
2307         }
2308         bj++;
2309       }
2310     }
2311     /*
2312       PetscPrintf(PETSC_COMM_SELF,"[%d], work: ",rank);
2313       for (i=0; i<bs*Mbs; i++) PetscPrintf(PETSC_COMM_SELF,"%g ",work[i]);
2314       PetscPrintf(PETSC_COMM_SELF,"[%d]: \n");
2315       */
2316 
2317     /* send values to its owners */
2318     for (dest=rank+1; dest<size; dest++){
2319       svalues = work + rowners_bs[dest];
2320       count = rowners_bs[dest+1]-rowners_bs[dest];
2321       ierr = MPI_Send(svalues,count,MPI_DOUBLE,dest,rank,PETSC_COMM_WORLD);CHKERRQ(ierr);
2322       /*
2323       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d] sends %d values to [%d]: %g, %g, %g, %g\n",rank,count,dest,svalues[0],svalues[1],svalues[2],svalues[3]);
2324       PetscSynchronizedFlush(PETSC_COMM_WORLD);
2325       */
2326     }
2327   }
2328 
2329   /* receive values */
2330   if (rank){
2331     rvalues = work;
2332     count = rowners_bs[rank+1]-rowners_bs[rank];
2333     for (source=0; source<rank; source++){
2334       ierr = MPI_Recv(rvalues,count,MPI_DOUBLE,MPI_ANY_SOURCE,MPI_ANY_TAG,PETSC_COMM_WORLD,&stat);CHKERRQ(ierr);
2335       /* process values */
2336       for (i=0; i<count; i++){
2337         if (PetscRealPart(va[i]) < rvalues[i]) va[i] = rvalues[i];
2338       }
2339       /*
2340       PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%d] received %d values from [%d]: %g, %g, %g, %g \n",rank,count,stat.MPI_SOURCE,rvalues[0],rvalues[1],rvalues[2],rvalues[3]);
2341       PetscSynchronizedFlush(PETSC_COMM_WORLD);
2342       */
2343     }
2344   }
2345 
2346   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2347   ierr = PetscFree(work);CHKERRQ(ierr);
2348   PetscFunctionReturn(0);
2349 }
2350