xref: /petsc/src/mat/impls/baij/mpi/baijov.c (revision ecfa4e3f7e08048e029ed54e0bfed65bf01ee008)
1 /*$Id: baijov.c,v 1.60 2001/03/06 20:15:24 balay Exp balay $*/
2 
3 /*
4    Routines to compute overlapping regions of a parallel MPI matrix
5   and to find submatrices that were shared across processors.
6 */
7 #include "src/mat/impls/baij/mpi/mpibaij.h"
8 #include "petscbt.h"
9 
10 static int MatIncreaseOverlap_MPIBAIJ_Once(Mat,int,IS *);
11 static int MatIncreaseOverlap_MPIBAIJ_Local(Mat,int,char **,int*,int**);
12 static int MatIncreaseOverlap_MPIBAIJ_Receive(Mat,int,int **,int**,int*);
13 EXTERN int MatGetRow_MPIBAIJ(Mat,int,int*,int**,Scalar**);
14 EXTERN int MatRestoreRow_MPIBAIJ(Mat,int,int*,int**,Scalar**);
15 
16 #undef __FUNC__
17 #define __FUNC__ "MatCompressIndicesGeneral_MPIBAIJ"
18 static int MatCompressIndicesGeneral_MPIBAIJ(Mat C,int imax,IS *is_in,IS *is_out)
19 {
20   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ*)C->data;
21   int          ierr,isz,bs = baij->bs,n,i,j,*idx,ival;
22 #if defined (PETSC_USE_CTABLE)
23   PetscTable   gid1_lid1;
24   int tt, gid1, *nidx;
25   PetscTablePosition tpos;
26 #else
27   int          Nbs,*nidx;
28   PetscBT      table;
29 #endif
30 
31   PetscFunctionBegin;
32 #if defined (PETSC_USE_CTABLE)
33   ierr = PetscTableCreate(baij->mbs,&gid1_lid1);CHKERRQ(ierr);
34 #else
35   Nbs  = baij->Nbs;
36   ierr = PetscMalloc((Nbs+1)*sizeof(int),&nidx);CHKERRQ(ierr);
37   ierr = PetscBTCreate(Nbs,table);CHKERRQ(ierr);
38 #endif
39   for (i=0; i<imax; i++) {
40     isz  = 0;
41 #if defined (PETSC_USE_CTABLE)
42     ierr = PetscTableRemoveAll(gid1_lid1);CHKERRQ(ierr);
43 #else
44     ierr = PetscBTMemzero(Nbs,table);CHKERRQ(ierr);
45 #endif
46     ierr = ISGetIndices(is_in[i],&idx);CHKERRQ(ierr);
47     ierr = ISGetLocalSize(is_in[i],&n);CHKERRQ(ierr);
48     for (j=0; j<n ; j++) {
49       ival = idx[j]/bs; /* convert the indices into block indices */
50 #if defined (PETSC_USE_CTABLE)
51       ierr = PetscTableFind(gid1_lid1,ival+1,&tt);CHKERRQ(ierr);
52       if (!tt) {
53 	ierr = PetscTableAdd(gid1_lid1,ival+1,isz+1);CHKERRQ(ierr);
54         isz++;
55       }
56 #else
57       if (ival>Nbs) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"index greater than mat-dim");
58       if(!PetscBTLookupSet(table,ival)) { nidx[isz++] = ival;}
59 #endif
60     }
61     ierr = ISRestoreIndices(is_in[i],&idx);CHKERRQ(ierr);
62 #if defined (PETSC_USE_CTABLE)
63     ierr = PetscMalloc((isz+1)*sizeof(int),&nidx);CHKERRQ(ierr);
64     ierr = PetscTableGetHeadPosition(gid1_lid1,&tpos);CHKERRQ(ierr);
65     j = 0;
66     while (tpos) {
67       ierr = PetscTableGetNext(gid1_lid1,&tpos,&gid1,&tt);CHKERRQ(ierr);
68       if (tt-- > isz) { SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"index greater than array-dim"); }
69       nidx[tt] = gid1 - 1;
70       j++;
71     }
72     if (j != isz) { SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"table error: jj != isz"); }
73     ierr = ISCreateGeneral(PETSC_COMM_SELF,isz,nidx,(is_out+i));CHKERRQ(ierr);
74     ierr = PetscFree(nidx);CHKERRQ(ierr);
75 #else
76     ierr = ISCreateGeneral(PETSC_COMM_SELF,isz,nidx,(is_out+i));CHKERRQ(ierr);
77 #endif
78   }
79 #if defined (PETSC_USE_CTABLE)
80   ierr = PetscTableDelete(gid1_lid1);CHKERRQ(ierr);
81 #else
82   ierr = PetscBTDestroy(table);CHKERRQ(ierr);
83   ierr = PetscFree(nidx);CHKERRQ(ierr);
84 #endif
85   PetscFunctionReturn(0);
86 }
87 
88 #undef __FUNC__
89 #define __FUNC__ "MatCompressIndicesSorted_MPIBAIJ"
90 static int MatCompressIndicesSorted_MPIBAIJ(Mat C,int imax,IS *is_in,IS *is_out)
91 {
92   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ*)C->data;
93   int          ierr,bs=baij->bs,i,j,k,val,n,*idx,*nidx,*idx_local;
94   PetscTruth   flg;
95 #if defined (PETSC_USE_CTABLE)
96   int maxsz;
97 #else
98   int Nbs=baij->Nbs;
99 #endif
100   PetscFunctionBegin;
101   for (i=0; i<imax; i++) {
102     ierr = ISSorted(is_in[i],&flg);CHKERRQ(ierr);
103     if (!flg) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Indices are not sorted");
104   }
105 #if defined (PETSC_USE_CTABLE)
106   /* Now check max size */
107   for (i=0,maxsz=0; i<imax; i++) {
108     ierr = ISGetIndices(is_in[i],&idx);CHKERRQ(ierr);
109     ierr = ISGetLocalSize(is_in[i],&n);CHKERRQ(ierr);
110     if (n%bs !=0) SETERRQ(1,"Indices are not block ordered");
111     n = n/bs; /* The reduced index size */
112     if (n > maxsz) maxsz = n;
113   }
114   ierr = PetscMalloc((maxsz+1)*sizeof(int),&nidx);CHKERRQ(ierr);
115 #else
116   ierr = PetscMalloc((Nbs+1)*sizeof(int),&nidx);CHKERRQ(ierr);
117 #endif
118   /* Now check if the indices are in block order */
119   for (i=0; i<imax; i++) {
120     ierr = ISGetIndices(is_in[i],&idx);CHKERRQ(ierr);
121     ierr = ISGetLocalSize(is_in[i],&n);CHKERRQ(ierr);
122     if (n%bs !=0) SETERRQ(1,"Indices are not block ordered");
123 
124     n = n/bs; /* The reduced index size */
125     idx_local = idx;
126     for (j=0; j<n ; j++) {
127       val = idx_local[0];
128       if (val%bs != 0) SETERRQ(1,"Indices are not block ordered");
129       for (k=0; k<bs; k++) {
130         if (val+k != idx_local[k]) SETERRQ(1,"Indices are not block ordered");
131       }
132       nidx[j] = val/bs;
133       idx_local +=bs;
134     }
135     ierr = ISRestoreIndices(is_in[i],&idx);CHKERRQ(ierr);
136     ierr = ISCreateGeneral(PETSC_COMM_SELF,n,nidx,(is_out+i));CHKERRQ(ierr);
137   }
138   ierr = PetscFree(nidx);CHKERRQ(ierr);
139 
140   PetscFunctionReturn(0);
141 }
142 
143 #undef __FUNC__
144 #define __FUNC__ "MatExpandIndices_MPIBAIJ"
145 static int MatExpandIndices_MPIBAIJ(Mat C,int imax,IS *is_in,IS *is_out)
146 {
147   Mat_MPIBAIJ  *baij = (Mat_MPIBAIJ*)C->data;
148   int          ierr,bs = baij->bs,n,i,j,k,*idx,*nidx;
149 #if defined (PETSC_USE_CTABLE)
150   int maxsz;
151 #else
152   int Nbs = baij->Nbs;
153 #endif
154   PetscFunctionBegin;
155 
156 #if defined (PETSC_USE_CTABLE)
157   /* Now check max size */
158   for (i=0,maxsz=0; i<imax; i++) {
159     ierr = ISGetIndices(is_in[i],&idx);CHKERRQ(ierr);
160     ierr = ISGetLocalSize(is_in[i],&n);CHKERRQ(ierr);
161     if (n*bs > maxsz) maxsz = n*bs;
162   }
163   ierr = PetscMalloc((maxsz+1)*sizeof(int),&nidx);CHKERRQ(ierr);
164 #else
165   ierr = PetscMalloc((Nbs*bs+1)*sizeof(int),&nidx);CHKERRQ(ierr);
166 #endif
167 
168   for (i=0; i<imax; i++) {
169     ierr = ISGetIndices(is_in[i],&idx);CHKERRQ(ierr);
170     ierr = ISGetLocalSize(is_in[i],&n);CHKERRQ(ierr);
171     for (j=0; j<n ; ++j){
172       for (k=0; k<bs; k++)
173         nidx[j*bs+k] = idx[j]*bs+k;
174     }
175     ierr = ISRestoreIndices(is_in[i],&idx);CHKERRQ(ierr);
176     ierr = ISCreateGeneral(PETSC_COMM_SELF,n*bs,nidx,is_out+i);CHKERRQ(ierr);
177   }
178   ierr = PetscFree(nidx);CHKERRQ(ierr);
179   PetscFunctionReturn(0);
180 }
181 
182 
183 #undef __FUNC__
184 #define __FUNC__ "MatIncreaseOverlap_MPIBAIJ"
185 int MatIncreaseOverlap_MPIBAIJ(Mat C,int imax,IS *is,int ov)
186 {
187   int i,ierr;
188   IS  *is_new;
189 
190   PetscFunctionBegin;
191   ierr = PetscMalloc(imax*sizeof(IS),&is_new);CHKERRQ(ierr);
192   /* Convert the indices into block format */
193   ierr = MatCompressIndicesGeneral_MPIBAIJ(C,imax,is,is_new);CHKERRQ(ierr);
194   if (ov < 0){ SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap specified\n");}
195   for (i=0; i<ov; ++i) {
196     ierr = MatIncreaseOverlap_MPIBAIJ_Once(C,imax,is_new);CHKERRQ(ierr);
197   }
198   for (i=0; i<imax; i++) {ierr = ISDestroy(is[i]);CHKERRQ(ierr);}
199   ierr = MatExpandIndices_MPIBAIJ(C,imax,is_new,is);CHKERRQ(ierr);
200   for (i=0; i<imax; i++) {ierr = ISDestroy(is_new[i]);CHKERRQ(ierr);}
201   ierr = PetscFree(is_new);CHKERRQ(ierr);
202   PetscFunctionReturn(0);
203 }
204 
205 /*
206   Sample message format:
207   If a processor A wants processor B to process some elements corresponding
208   to index sets 1s[1], is[5]
209   mesg [0] = 2   (no of index sets in the mesg)
210   -----------
211   mesg [1] = 1 => is[1]
212   mesg [2] = sizeof(is[1]);
213   -----------
214   mesg [5] = 5  => is[5]
215   mesg [6] = sizeof(is[5]);
216   -----------
217   mesg [7]
218   mesg [n]  datas[1]
219   -----------
220   mesg[n+1]
221   mesg[m]  data(is[5])
222   -----------
223 
224   Notes:
225   nrqs - no of requests sent (or to be sent out)
226   nrqr - no of requests recieved (which have to be or which have been processed
227 */
228 #undef __FUNC__
229 #define __FUNC__ "MatIncreaseOverlap_MPIBAIJ_Once"
230 static int MatIncreaseOverlap_MPIBAIJ_Once(Mat C,int imax,IS *is)
231 {
232   Mat_MPIBAIJ  *c = (Mat_MPIBAIJ*)C->data;
233   int         **idx,*n,*w1,*w2,*w3,*w4,*rtable,**data,len,*idx_i;
234   int         size,rank,Mbs,i,j,k,ierr,**rbuf,row,proc,nrqs,msz,**outdat,**ptr;
235   int         *ctr,*pa,*tmp,nrqr,*isz,*isz1,**xdata,**rbuf2;
236   int         *onodes1,*olengths1,tag1,tag2,*onodes2,*olengths2;
237   PetscBT     *table;
238   MPI_Comm    comm;
239   MPI_Request *s_waits1,*r_waits1,*s_waits2,*r_waits2;
240   MPI_Status  *s_status,*recv_status;
241 
242   PetscFunctionBegin;
243   comm   = C->comm;
244   size   = c->size;
245   rank   = c->rank;
246   Mbs    = c->Mbs;
247 
248   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
249   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
250 
251   len    = (imax+1)*sizeof(int*)+ (imax + Mbs)*sizeof(int);
252   ierr   = PetscMalloc(len,&idx);CHKERRQ(ierr);
253   n      = (int*)(idx + imax);
254   rtable = n + imax;
255 
256   for (i=0; i<imax; i++) {
257     ierr = ISGetIndices(is[i],&idx[i]);CHKERRQ(ierr);
258     ierr = ISGetLocalSize(is[i],&n[i]);CHKERRQ(ierr);
259   }
260 
261   /* Create hash table for the mapping :row -> proc*/
262   for (i=0,j=0; i<size; i++) {
263     len = c->rowners[i+1];
264     for (; j<len; j++) {
265       rtable[j] = i;
266     }
267   }
268 
269   /* evaluate communication - mesg to who,length of mesg, and buffer space
270      required. Based on this, buffers are allocated, and data copied into them*/
271   ierr = PetscMalloc(size*4*sizeof(int),&w1);CHKERRQ(ierr);/*  mesg size */
272   w2   = w1 + size;       /* if w2[i] marked, then a message to proc i*/
273   w3   = w2 + size;       /* no of IS that needs to be sent to proc i */
274   w4   = w3 + size;       /* temp work space used in determining w1, w2, w3 */
275   ierr = PetscMemzero(w1,size*3*sizeof(int));CHKERRQ(ierr); /* initialise work vector*/
276   for (i=0; i<imax; i++) {
277     ierr  = PetscMemzero(w4,size*sizeof(int));CHKERRQ(ierr); /* initialise work vector*/
278     idx_i = idx[i];
279     len   = n[i];
280     for (j=0; j<len; j++) {
281       row  = idx_i[j];
282       if (row < 0) {
283         SETERRQ(1,"Index set cannot have negative entries");
284       }
285       proc = rtable[row];
286       w4[proc]++;
287     }
288     for (j=0; j<size; j++){
289       if (w4[j]) { w1[j] += w4[j]; w3[j]++;}
290     }
291   }
292 
293   nrqs     = 0;              /* no of outgoing messages */
294   msz      = 0;              /* total mesg length (for all proc */
295   w1[rank] = 0;              /* no mesg sent to intself */
296   w3[rank] = 0;
297   for (i=0; i<size; i++) {
298     if (w1[i])  {w2[i] = 1; nrqs++;} /* there exists a message to proc i */
299   }
300   /* pa - is list of processors to communicate with */
301   ierr = PetscMalloc((nrqs+1)*sizeof(int),&pa);CHKERRQ(ierr);
302   for (i=0,j=0; i<size; i++) {
303     if (w1[i]) {pa[j] = i; j++;}
304   }
305 
306   /* Each message would have a header = 1 + 2*(no of IS) + data */
307   for (i=0; i<nrqs; i++) {
308     j      = pa[i];
309     w1[j] += w2[j] + 2*w3[j];
310     msz   += w1[j];
311   }
312 
313   /* Determine the number of messages to expect, their lengths, from from-ids */
314   ierr = PetscGatherNumberOfMessages(comm,nrqs,w2,w1,&nrqr);CHKERRQ(ierr);
315   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
316 
317   /* Now post the Irecvs corresponding to these messages */
318   ierr = PetscPostIrecvInt(comm,tag1,nrqr,onodes1,olengths1,&rbuf,&r_waits1);CHKERRQ(ierr);
319 
320   /* Allocate Memory for outgoing messages */
321   len    = 2*size*sizeof(int*) + (size+msz)*sizeof(int);
322   ierr = PetscMalloc(len,&outdat);CHKERRQ(ierr);
323   ptr    = outdat + size;     /* Pointers to the data in outgoing buffers */
324   ierr   = PetscMemzero(outdat,2*size*sizeof(int*));CHKERRQ(ierr);
325   tmp    = (int*)(outdat + 2*size);
326   ctr    = tmp + msz;
327 
328   {
329     int *iptr = tmp,ict  = 0;
330     for (i=0; i<nrqs; i++) {
331       j         = pa[i];
332       iptr     +=  ict;
333       outdat[j] = iptr;
334       ict       = w1[j];
335     }
336   }
337 
338   /* Form the outgoing messages */
339   /*plug in the headers*/
340   for (i=0; i<nrqs; i++) {
341     j            = pa[i];
342     outdat[j][0] = 0;
343     ierr = PetscMemzero(outdat[j]+1,2*w3[j]*sizeof(int));CHKERRQ(ierr);
344     ptr[j]       = outdat[j] + 2*w3[j] + 1;
345   }
346 
347   /* Memory for doing local proc's work*/
348   {
349     int  *d_p;
350     char *t_p;
351 
352     len  = (imax)*(sizeof(PetscBT) + sizeof(int*)+ sizeof(int)) +
353       (Mbs)*imax*sizeof(int)  + (Mbs/BITSPERBYTE+1)*imax*sizeof(char) + 1;
354     ierr = PetscMalloc(len,&table);CHKERRQ(ierr);
355     ierr = PetscMemzero(table,len);CHKERRQ(ierr);
356     data = (int **)(table + imax);
357     isz  = (int  *)(data  + imax);
358     d_p  = (int  *)(isz   + imax);
359     t_p  = (char *)(d_p   + Mbs*imax);
360     for (i=0; i<imax; i++) {
361       table[i] = t_p + (Mbs/BITSPERBYTE+1)*i;
362       data[i]  = d_p + (Mbs)*i;
363     }
364   }
365 
366   /* Parse the IS and update local tables and the outgoing buf with the data*/
367   {
368     int     n_i,*data_i,isz_i,*outdat_j,ctr_j;
369     PetscBT table_i;
370 
371     for (i=0; i<imax; i++) {
372       ierr    = PetscMemzero(ctr,size*sizeof(int));CHKERRQ(ierr);
373       n_i     = n[i];
374       table_i = table[i];
375       idx_i   = idx[i];
376       data_i  = data[i];
377       isz_i   = isz[i];
378       for (j=0;  j<n_i; j++) {  /* parse the indices of each IS */
379         row  = idx_i[j];
380         proc = rtable[row];
381         if (proc != rank) { /* copy to the outgoing buffer */
382           ctr[proc]++;
383           *ptr[proc] = row;
384           ptr[proc]++;
385         }
386         else { /* Update the local table */
387           if (!PetscBTLookupSet(table_i,row)) { data_i[isz_i++] = row;}
388         }
389       }
390       /* Update the headers for the current IS */
391       for (j=0; j<size; j++) { /* Can Optimise this loop by using pa[] */
392         if ((ctr_j = ctr[j])) {
393           outdat_j        = outdat[j];
394           k               = ++outdat_j[0];
395           outdat_j[2*k]   = ctr_j;
396           outdat_j[2*k-1] = i;
397         }
398       }
399       isz[i] = isz_i;
400     }
401   }
402 
403   /*  Now  post the sends */
404   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Request),&s_waits1);CHKERRQ(ierr);
405   for (i=0; i<nrqs; ++i) {
406     j    = pa[i];
407     ierr = MPI_Isend(outdat[j],w1[j],MPI_INT,j,tag1,comm,s_waits1+i);CHKERRQ(ierr);
408   }
409 
410   /* No longer need the original indices*/
411   for (i=0; i<imax; ++i) {
412     ierr = ISRestoreIndices(is[i],idx+i);CHKERRQ(ierr);
413   }
414   ierr = PetscFree(idx);CHKERRQ(ierr);
415 
416   for (i=0; i<imax; ++i) {
417     ierr = ISDestroy(is[i]);CHKERRQ(ierr);
418   }
419 
420   /* Do Local work*/
421   ierr = MatIncreaseOverlap_MPIBAIJ_Local(C,imax,table,isz,data);CHKERRQ(ierr);
422 
423   /* Receive messages*/
424   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Status),&recv_status);CHKERRQ(ierr);
425   ierr = MPI_Waitall(nrqr,r_waits1,recv_status);CHKERRQ(ierr);
426 
427   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&s_status);CHKERRQ(ierr);
428   ierr = MPI_Waitall(nrqs,s_waits1,s_status);CHKERRQ(ierr);
429 
430   /* Phase 1 sends are complete - deallocate buffers */
431   ierr = PetscFree(outdat);CHKERRQ(ierr);
432   ierr = PetscFree(w1);CHKERRQ(ierr);
433 
434   ierr = PetscMalloc((nrqr+1)*sizeof(int *),&xdata);CHKERRQ(ierr);
435   ierr = PetscMalloc((nrqr+1)*sizeof(int),&isz1);CHKERRQ(ierr);
436   ierr = MatIncreaseOverlap_MPIBAIJ_Receive(C,nrqr,rbuf,xdata,isz1);CHKERRQ(ierr);
437   ierr = PetscFree(rbuf);CHKERRQ(ierr);
438 
439   /* Send the data back*/
440   /* Do a global reduction to know the buffer space req for incoming messages*/
441   {
442     int *rw1;
443 
444     ierr = PetscMalloc(size*sizeof(int),&rw1);CHKERRQ(ierr);
445     ierr = PetscMemzero(rw1,size*sizeof(int));CHKERRQ(ierr);
446 
447     for (i=0; i<nrqr; ++i) {
448       proc      = recv_status[i].MPI_SOURCE;
449       if (proc != onodes1[i]) SETERRQ(1,"MPI_SOURCE mismatch");
450       rw1[proc] = isz1[i];
451     }
452 
453     ierr = PetscFree(onodes1);CHKERRQ(ierr);
454     ierr = PetscFree(olengths1);CHKERRQ(ierr);
455 
456     /* Determine the number of messages to expect, their lengths, from from-ids */
457     ierr = PetscGatherMessageLengths(comm,nrqr,nrqs,rw1,&onodes2,&olengths2);CHKERRQ(ierr);
458     PetscFree(rw1);
459   }
460   /* Now post the Irecvs corresponding to these messages */
461   ierr = PetscPostIrecvInt(comm,tag2,nrqs,onodes2,olengths2,&rbuf2,&r_waits2);CHKERRQ(ierr);
462 
463   /*  Now  post the sends */
464   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits2);CHKERRQ(ierr);
465   for (i=0; i<nrqr; ++i) {
466     j    = recv_status[i].MPI_SOURCE;
467     ierr = MPI_Isend(xdata[i],isz1[i],MPI_INT,j,tag2,comm,s_waits2+i);CHKERRQ(ierr);
468   }
469 
470   /* receive work done on other processors*/
471   {
472     int         index,is_no,ct1,max,*rbuf2_i,isz_i,*data_i,jmax;
473     PetscBT     table_i;
474     MPI_Status  *status2;
475 
476     ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&status2);CHKERRQ(ierr);
477 
478     for (i=0; i<nrqs; ++i) {
479       ierr = MPI_Waitany(nrqs,r_waits2,&index,status2+i);CHKERRQ(ierr);
480       /* Process the message*/
481       rbuf2_i = rbuf2[index];
482       ct1     = 2*rbuf2_i[0]+1;
483       jmax    = rbuf2[index][0];
484       for (j=1; j<=jmax; j++) {
485         max     = rbuf2_i[2*j];
486         is_no   = rbuf2_i[2*j-1];
487         isz_i   = isz[is_no];
488         data_i  = data[is_no];
489         table_i = table[is_no];
490         for (k=0; k<max; k++,ct1++) {
491           row = rbuf2_i[ct1];
492           if (!PetscBTLookupSet(table_i,row)) { data_i[isz_i++] = row;}
493         }
494         isz[is_no] = isz_i;
495       }
496     }
497     ierr = MPI_Waitall(nrqr,s_waits2,status2);CHKERRQ(ierr);
498     ierr = PetscFree(status2);CHKERRQ(ierr);
499   }
500 
501   for (i=0; i<imax; ++i) {
502     ierr = ISCreateGeneral(PETSC_COMM_SELF,isz[i],data[i],is+i);CHKERRQ(ierr);
503   }
504 
505 
506   ierr = PetscFree(onodes2);CHKERRQ(ierr);
507   ierr = PetscFree(olengths2);CHKERRQ(ierr);
508 
509   ierr = PetscFree(pa);CHKERRQ(ierr);
510   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
511   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
512   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
513   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
514   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
515   ierr = PetscFree(table);CHKERRQ(ierr);
516   ierr = PetscFree(s_status);CHKERRQ(ierr);
517   ierr = PetscFree(recv_status);CHKERRQ(ierr);
518   ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
519   ierr = PetscFree(xdata);CHKERRQ(ierr);
520   ierr = PetscFree(isz1);CHKERRQ(ierr);
521   PetscFunctionReturn(0);
522 }
523 
524 #undef __FUNC__
525 #define __FUNC__ "MatIncreaseOverlap_MPIBAIJ_Local"
526 /*
527    MatIncreaseOverlap_MPIBAIJ_Local - Called by MatincreaseOverlap, to do
528        the work on the local processor.
529 
530      Inputs:
531       C      - MAT_MPIBAIJ;
532       imax - total no of index sets processed at a time;
533       table  - an array of char - size = Mbs bits.
534 
535      Output:
536       isz    - array containing the count of the solution elements correspondign
537                to each index set;
538       data   - pointer to the solutions
539 */
540 static int MatIncreaseOverlap_MPIBAIJ_Local(Mat C,int imax,PetscBT *table,int *isz,int **data)
541 {
542   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
543   Mat         A = c->A,B = c->B;
544   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
545   int         start,end,val,max,rstart,cstart,*ai,*aj;
546   int         *bi,*bj,*garray,i,j,k,row,*data_i,isz_i;
547   PetscBT     table_i;
548 
549   PetscFunctionBegin;
550   rstart = c->rstart;
551   cstart = c->cstart;
552   ai     = a->i;
553   aj     = a->j;
554   bi     = b->i;
555   bj     = b->j;
556   garray = c->garray;
557 
558 
559   for (i=0; i<imax; i++) {
560     data_i  = data[i];
561     table_i = table[i];
562     isz_i   = isz[i];
563     for (j=0,max=isz[i]; j<max; j++) {
564       row   = data_i[j] - rstart;
565       start = ai[row];
566       end   = ai[row+1];
567       for (k=start; k<end; k++) { /* Amat */
568         val = aj[k] + cstart;
569         if (!PetscBTLookupSet(table_i,val)) { data_i[isz_i++] = val;}
570       }
571       start = bi[row];
572       end   = bi[row+1];
573       for (k=start; k<end; k++) { /* Bmat */
574         val = garray[bj[k]];
575         if (!PetscBTLookupSet(table_i,val)) { data_i[isz_i++] = val;}
576       }
577     }
578     isz[i] = isz_i;
579   }
580   PetscFunctionReturn(0);
581 }
582 #undef __FUNC__
583 #define __FUNC__ "MatIncreaseOverlap_MPIBAIJ_Receive"
584 /*
585       MatIncreaseOverlap_MPIBAIJ_Receive - Process the recieved messages,
586          and return the output
587 
588          Input:
589            C    - the matrix
590            nrqr - no of messages being processed.
591            rbuf - an array of pointers to the recieved requests
592 
593          Output:
594            xdata - array of messages to be sent back
595            isz1  - size of each message
596 
597   For better efficiency perhaps we should malloc seperately each xdata[i],
598 then if a remalloc is required we need only copy the data for that one row
599 rather then all previous rows as it is now where a single large chunck of
600 memory is used.
601 
602 */
603 static int MatIncreaseOverlap_MPIBAIJ_Receive(Mat C,int nrqr,int **rbuf,int **xdata,int * isz1)
604 {
605   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
606   Mat         A = c->A,B = c->B;
607   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
608   int         rstart,cstart,*ai,*aj,*bi,*bj,*garray,i,j,k;
609   int         row,total_sz,ct,ct1,ct2,ct3,mem_estimate,oct2,l,start,end;
610   int         val,max1,max2,rank,Mbs,no_malloc =0,*tmp,new_estimate,ctr;
611   int         *rbuf_i,kmax,rbuf_0,ierr;
612   PetscBT     xtable;
613 
614   PetscFunctionBegin;
615   rank   = c->rank;
616   Mbs    = c->Mbs;
617   rstart = c->rstart;
618   cstart = c->cstart;
619   ai     = a->i;
620   aj     = a->j;
621   bi     = b->i;
622   bj     = b->j;
623   garray = c->garray;
624 
625 
626   for (i=0,ct=0,total_sz=0; i<nrqr; ++i) {
627     rbuf_i  =  rbuf[i];
628     rbuf_0  =  rbuf_i[0];
629     ct     += rbuf_0;
630     for (j=1; j<=rbuf_0; j++) { total_sz += rbuf_i[2*j]; }
631   }
632 
633   if (c->Mbs) max1 = ct*(a->nz +b->nz)/c->Mbs;
634   else        max1 = 1;
635   mem_estimate = 3*((total_sz > max1 ? total_sz : max1)+1);
636   ierr         = PetscMalloc(mem_estimate*sizeof(int),&xdata[0]);CHKERRQ(ierr);
637   ++no_malloc;
638   ierr         = PetscBTCreate(Mbs,xtable);CHKERRQ(ierr);
639   ierr         = PetscMemzero(isz1,nrqr*sizeof(int));CHKERRQ(ierr);
640 
641   ct3 = 0;
642   for (i=0; i<nrqr; i++) { /* for easch mesg from proc i */
643     rbuf_i =  rbuf[i];
644     rbuf_0 =  rbuf_i[0];
645     ct1    =  2*rbuf_0+1;
646     ct2    =  ct1;
647     ct3    += ct1;
648     for (j=1; j<=rbuf_0; j++) { /* for each IS from proc i*/
649       ierr = PetscBTMemzero(Mbs,xtable);CHKERRQ(ierr);
650       oct2 = ct2;
651       kmax = rbuf_i[2*j];
652       for (k=0; k<kmax; k++,ct1++) {
653         row = rbuf_i[ct1];
654         if (!PetscBTLookupSet(xtable,row)) {
655           if (!(ct3 < mem_estimate)) {
656             new_estimate = (int)(1.5*mem_estimate)+1;
657             ierr = PetscMalloc(new_estimate * sizeof(int),&tmp);CHKERRQ(ierr);
658             ierr = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(int));CHKERRQ(ierr);
659             ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
660             xdata[0]     = tmp;
661             mem_estimate = new_estimate; ++no_malloc;
662             for (ctr=1; ctr<=i; ctr++) { xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];}
663           }
664           xdata[i][ct2++] = row;
665           ct3++;
666         }
667       }
668       for (k=oct2,max2=ct2; k<max2; k++)  {
669         row   = xdata[i][k] - rstart;
670         start = ai[row];
671         end   = ai[row+1];
672         for (l=start; l<end; l++) {
673           val = aj[l] + cstart;
674           if (!PetscBTLookupSet(xtable,val)) {
675             if (!(ct3 < mem_estimate)) {
676               new_estimate = (int)(1.5*mem_estimate)+1;
677               ierr = PetscMalloc(new_estimate * sizeof(int),&tmp);CHKERRQ(ierr);
678               ierr = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(int));CHKERRQ(ierr);
679               ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
680               xdata[0]     = tmp;
681               mem_estimate = new_estimate; ++no_malloc;
682               for (ctr=1; ctr<=i; ctr++) { xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];}
683             }
684             xdata[i][ct2++] = val;
685             ct3++;
686           }
687         }
688         start = bi[row];
689         end   = bi[row+1];
690         for (l=start; l<end; l++) {
691           val = garray[bj[l]];
692           if (!PetscBTLookupSet(xtable,val)) {
693             if (!(ct3 < mem_estimate)) {
694               new_estimate = (int)(1.5*mem_estimate)+1;
695               ierr = PetscMalloc(new_estimate * sizeof(int),&tmp);CHKERRQ(ierr);
696               ierr = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(int));CHKERRQ(ierr);
697               ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
698               xdata[0]     = tmp;
699               mem_estimate = new_estimate; ++no_malloc;
700               for (ctr =1; ctr <=i; ctr++) { xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];}
701             }
702             xdata[i][ct2++] = val;
703             ct3++;
704           }
705         }
706       }
707       /* Update the header*/
708       xdata[i][2*j]   = ct2 - oct2; /* Undo the vector isz1 and use only a var*/
709       xdata[i][2*j-1] = rbuf_i[2*j-1];
710     }
711     xdata[i][0] = rbuf_0;
712     xdata[i+1]  = xdata[i] + ct2;
713     isz1[i]     = ct2; /* size of each message */
714   }
715   ierr = PetscBTDestroy(xtable);CHKERRQ(ierr);
716   PetscLogInfo(0,"MatIncreaseOverlap_MPIBAIJ:[%d] Allocated %d bytes, required %d, no of mallocs = %d\n",rank,mem_estimate,ct3,no_malloc);
717   PetscFunctionReturn(0);
718 }
719 
720 static int MatGetSubMatrices_MPIBAIJ_local(Mat,int,IS *,IS *,MatReuse,Mat *);
721 
722 #undef __FUNC__
723 #define __FUNC__ "MatGetSubMatrices_MPIBAIJ"
724 int MatGetSubMatrices_MPIBAIJ(Mat C,int ismax,IS *isrow,IS *iscol,MatReuse scall,Mat **submat)
725 {
726   IS          *isrow_new,*iscol_new;
727   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
728   int         nmax,nstages_local,nstages,i,pos,max_no,ierr;
729 
730   PetscFunctionBegin;
731   /* The compression and expansion should be avoided. Does'nt point
732      out errors might change the indices hence buggey */
733 
734   ierr = PetscMalloc(2*(ismax+1)*sizeof(IS),&isrow_new);CHKERRQ(ierr);
735   iscol_new = isrow_new + ismax;
736   ierr = MatCompressIndicesSorted_MPIBAIJ(C,ismax,isrow,isrow_new);CHKERRQ(ierr);
737   ierr = MatCompressIndicesSorted_MPIBAIJ(C,ismax,iscol,iscol_new);CHKERRQ(ierr);
738 
739   /* Allocate memory to hold all the submatrices */
740   if (scall != MAT_REUSE_MATRIX) {
741     ierr = PetscMalloc((ismax+1)*sizeof(Mat),submat);CHKERRQ(ierr);
742   }
743   /* Determine the number of stages through which submatrices are done */
744   nmax          = 20*1000000 / (c->Nbs * sizeof(int));
745   if (!nmax) nmax = 1;
746   nstages_local = ismax/nmax + ((ismax % nmax)?1:0);
747 
748   /* Make sure every porcessor loops through the nstages */
749   ierr = MPI_Allreduce(&nstages_local,&nstages,1,MPI_INT,MPI_MAX,C->comm);CHKERRQ(ierr);
750   for (i=0,pos=0; i<nstages; i++) {
751     if (pos+nmax <= ismax) max_no = nmax;
752     else if (pos == ismax) max_no = 0;
753     else                   max_no = ismax-pos;
754     ierr = MatGetSubMatrices_MPIBAIJ_local(C,max_no,isrow_new+pos,iscol_new+pos,scall,*submat+pos);CHKERRQ(ierr);
755     pos += max_no;
756   }
757 
758   for (i=0; i<ismax; i++) {
759     ierr = ISDestroy(isrow_new[i]);CHKERRQ(ierr);
760     ierr = ISDestroy(iscol_new[i]);CHKERRQ(ierr);
761   }
762   ierr = PetscFree(isrow_new);CHKERRQ(ierr);
763   PetscFunctionReturn(0);
764 }
765 
766 #if defined (PETSC_USE_CTABLE)
767 #undef __FUNC__
768 #define __FUNC__ "PetscGetProc"
769 int PetscGetProc(const int gid, const int numprocs, const int proc_gnode[], int *proc)
770 {
771   int nGlobalNd = proc_gnode[numprocs];
772   int fproc = (int) ((float)gid * (float)numprocs / (float)nGlobalNd + 0.5);
773 
774   PetscFunctionBegin;
775   /* if(fproc < 0) SETERRQ(1,"fproc < 0");*/
776   if (fproc > numprocs) fproc = numprocs;
777   while (gid < proc_gnode[fproc] || gid >= proc_gnode[fproc+1]) {
778     if (gid < proc_gnode[fproc]) fproc--;
779     else                         fproc++;
780   }
781   /* if(fproc<0 || fproc>=numprocs) { SETERRQ(1,"fproc < 0 || fproc >= numprocs"); }*/
782   *proc = fproc;
783   PetscFunctionReturn(0);
784 }
785 #endif
786 
787 /* -------------------------------------------------------------------------*/
788 #undef __FUNC__
789 #define __FUNC__ "MatGetSubMatrices_MPIBAIJ_local"
790 static int MatGetSubMatrices_MPIBAIJ_local(Mat C,int ismax,IS *isrow,IS *iscol,MatReuse scall,Mat *submats)
791 {
792   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
793   Mat         A = c->A;
794   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*mat;
795   int         **irow,**icol,*nrow,*ncol,*w1,*w2,*w3,*w4,start,end,size;
796   int         **sbuf1,**sbuf2,rank,i,j,k,l,ct1,ct2,ierr,**rbuf1,row,proc;
797   int         nrqs,msz,**ptr,index,*req_size,*ctr,*pa,*tmp,tcol,nrqr;
798   int         **rbuf3,*req_source,**sbuf_aj,**rbuf2,max1,max2;
799   int         **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax,*irow_i;
800   int         len,ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
801   int         bs=c->bs,bs2=c->bs2,*a_j=a->j,*b_j=b->j,*cworkA,*cworkB;
802   int         cstart = c->cstart,nzA,nzB,*a_i=a->i,*b_i=b->i,imark;
803   int         *bmap = c->garray,ctmp,rstart=c->rstart,tag0,tag1,tag2,tag3;
804   MPI_Request *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3;
805   MPI_Request *r_waits4,*s_waits3,*s_waits4;
806   MPI_Status  *r_status1,*r_status2,*s_status1,*s_status3,*s_status2;
807   MPI_Status  *r_status3,*r_status4,*s_status4;
808   MPI_Comm    comm;
809   MatScalar   **rbuf4,**sbuf_aa,*vals,*mat_a,*sbuf_aa_i,*vworkA,*vworkB;
810   MatScalar   *a_a=a->a,*b_a=b->a;
811   PetscTruth  flag;
812   int         *onodes1,*olengths1;
813 
814 #if defined (PETSC_USE_CTABLE)
815   int tt;
816   PetscTable  *rowmaps,*colmaps,lrow1_grow1,lcol1_gcol1;
817 #else
818   int         **cmap,*cmap_i,*rtable,*rmap_i,**rmap, Mbs = c->Mbs;
819 #endif
820 
821   PetscFunctionBegin;
822   comm   = C->comm;
823   tag0   = C->tag;
824   size   = c->size;
825   rank   = c->rank;
826 
827   /* Get some new tags to keep the communication clean */
828   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
829   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
830   ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
831 
832   /* Check if the col indices are sorted */
833   for (i=0; i<ismax; i++) {
834     ierr = ISSorted(iscol[i],(PetscTruth*)&j);CHKERRQ(ierr);
835     if (!j) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"IS is not sorted");
836   }
837 
838   len    = (2*ismax+1)*(sizeof(int*)+ sizeof(int));
839 #if !defined (PETSC_USE_CTABLE)
840   len    += (Mbs+1)*sizeof(int);
841 #endif
842   ierr = PetscMalloc(len,&irow);CHKERRQ(ierr);
843   icol = irow + ismax;
844   nrow = (int*)(icol + ismax);
845   ncol = nrow + ismax;
846 #if !defined (PETSC_USE_CTABLE)
847   rtable = ncol + ismax;
848   /* Create hash table for the mapping :row -> proc*/
849   for (i=0,j=0; i<size; i++) {
850     jmax = c->rowners[i+1];
851     for (; j<jmax; j++) {
852       rtable[j] = i;
853     }
854   }
855 #endif
856 
857   for (i=0; i<ismax; i++) {
858     ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
859     ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
860     ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
861     ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
862   }
863 
864   /* evaluate communication - mesg to who,length of mesg,and buffer space
865      required. Based on this, buffers are allocated, and data copied into them*/
866   ierr = PetscMalloc(size*4*sizeof(int),&w1);CHKERRQ(ierr); /* mesg size */
867   w2   = w1 + size;      /* if w2[i] marked, then a message to proc i*/
868   w3   = w2 + size;      /* no of IS that needs to be sent to proc i */
869   w4   = w3 + size;      /* temp work space used in determining w1, w2, w3 */
870   ierr = PetscMemzero(w1,size*3*sizeof(int));CHKERRQ(ierr); /* initialise work vector*/
871   for (i=0; i<ismax; i++) {
872     ierr   = PetscMemzero(w4,size*sizeof(int));CHKERRQ(ierr); /* initialise work vector*/
873     jmax   = nrow[i];
874     irow_i = irow[i];
875     for (j=0; j<jmax; j++) {
876       row  = irow_i[j];
877 #if defined (PETSC_USE_CTABLE)
878       ierr = PetscGetProc(row,size,c->rowners,&proc);CHKERRQ(ierr);
879 #else
880       proc = rtable[row];
881 #endif
882       w4[proc]++;
883     }
884     for (j=0; j<size; j++) {
885       if (w4[j]) { w1[j] += w4[j];  w3[j]++;}
886     }
887   }
888 
889   nrqs     = 0;              /* no of outgoing messages */
890   msz      = 0;              /* total mesg length for all proc */
891   w1[rank] = 0;              /* no mesg sent to intself */
892   w3[rank] = 0;
893   for (i=0; i<size; i++) {
894     if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
895   }
896   ierr = PetscMalloc((nrqs+1)*sizeof(int),&pa);CHKERRQ(ierr); /*(proc -array)*/
897   for (i=0,j=0; i<size; i++) {
898     if (w1[i]) { pa[j] = i; j++; }
899   }
900 
901   /* Each message would have a header = 1 + 2*(no of IS) + data */
902   for (i=0; i<nrqs; i++) {
903     j     = pa[i];
904     w1[j] += w2[j] + 2* w3[j];
905     msz   += w1[j];
906   }
907 
908   /* Determine the number of messages to expect, their lengths, from from-ids */
909   ierr = PetscGatherNumberOfMessages(comm,nrqs,w2,w1,&nrqr);CHKERRQ(ierr);
910   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
911 
912   /* Now post the Irecvs corresponding to these messages */
913   ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
914 
915   ierr = PetscFree(onodes1);CHKERRQ(ierr);
916   ierr = PetscFree(olengths1);CHKERRQ(ierr);
917 
918   /* Allocate Memory for outgoing messages */
919   len  = 2*size*sizeof(int*) + 2*msz*sizeof(int) + size*sizeof(int);
920   ierr = PetscMalloc(len,&sbuf1);CHKERRQ(ierr);
921   ptr  = sbuf1 + size;   /* Pointers to the data in outgoing buffers */
922   ierr = PetscMemzero(sbuf1,2*size*sizeof(int*));CHKERRQ(ierr);
923   /* allocate memory for outgoing data + buf to receive the first reply */
924   tmp  = (int*)(ptr + size);
925   ctr  = tmp + 2*msz;
926 
927   {
928     int *iptr = tmp,ict = 0;
929     for (i=0; i<nrqs; i++) {
930       j         = pa[i];
931       iptr     += ict;
932       sbuf1[j]  = iptr;
933       ict       = w1[j];
934     }
935   }
936 
937   /* Form the outgoing messages */
938   /* Initialise the header space */
939   for (i=0; i<nrqs; i++) {
940     j           = pa[i];
941     sbuf1[j][0] = 0;
942     ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(int));CHKERRQ(ierr);
943     ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
944   }
945 
946   /* Parse the isrow and copy data into outbuf */
947   for (i=0; i<ismax; i++) {
948     ierr   = PetscMemzero(ctr,size*sizeof(int));CHKERRQ(ierr);
949     irow_i = irow[i];
950     jmax   = nrow[i];
951     for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
952       row  = irow_i[j];
953 #if defined (PETSC_USE_CTABLE)
954       ierr = PetscGetProc(row,size,c->rowners,&proc);CHKERRQ(ierr);
955 #else
956       proc = rtable[row];
957 #endif
958       if (proc != rank) { /* copy to the outgoing buf*/
959         ctr[proc]++;
960         *ptr[proc] = row;
961         ptr[proc]++;
962       }
963     }
964     /* Update the headers for the current IS */
965     for (j=0; j<size; j++) { /* Can Optimise this loop too */
966       if ((ctr_j == ctr[j])) {
967         sbuf1_j        = sbuf1[j];
968         k              = ++sbuf1_j[0];
969         sbuf1_j[2*k]   = ctr_j;
970         sbuf1_j[2*k-1] = i;
971       }
972     }
973   }
974 
975   /*  Now  post the sends */
976   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Request),&s_waits1);CHKERRQ(ierr);
977   for (i=0; i<nrqs; ++i) {
978     j = pa[i];
979     ierr = MPI_Isend(sbuf1[j],w1[j],MPI_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
980   }
981 
982   /* Post Recieves to capture the buffer size */
983   ierr     = PetscMalloc((nrqs+1)*sizeof(MPI_Request),&r_waits2);CHKERRQ(ierr);
984   ierr     = PetscMalloc((nrqs+1)*sizeof(int *),&rbuf2);CHKERRQ(ierr);
985   rbuf2[0] = tmp + msz;
986   for (i=1; i<nrqs; ++i) {
987     j        = pa[i];
988     rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
989   }
990   for (i=0; i<nrqs; ++i) {
991     j    = pa[i];
992     ierr = MPI_Irecv(rbuf2[i],w1[j],MPI_INT,j,tag1,comm,r_waits2+i);CHKERRQ(ierr);
993   }
994 
995   /* Send to other procs the buf size they should allocate */
996 
997   /* Receive messages*/
998   ierr       = PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits2);CHKERRQ(ierr);
999   ierr       = PetscMalloc((nrqr+1)*sizeof(MPI_Status),&r_status1);CHKERRQ(ierr);
1000   len        = 2*nrqr*sizeof(int) + (nrqr+1)*sizeof(int*);
1001   ierr       = PetscMalloc(len,&sbuf2);CHKERRQ(ierr);
1002   req_size   = (int*)(sbuf2 + nrqr);
1003   req_source = req_size + nrqr;
1004 
1005   {
1006     Mat_SeqBAIJ *sA = (Mat_SeqBAIJ*)c->A->data,*sB = (Mat_SeqBAIJ*)c->B->data;
1007     int        *sAi = sA->i,*sBi = sB->i,id,*sbuf2_i;
1008 
1009     for (i=0; i<nrqr; ++i) {
1010       ierr = MPI_Waitany(nrqr,r_waits1,&index,r_status1+i);CHKERRQ(ierr);
1011       req_size[index] = 0;
1012       rbuf1_i         = rbuf1[index];
1013       start           = 2*rbuf1_i[0] + 1;
1014       ierr            = MPI_Get_count(r_status1+i,MPI_INT,&end);CHKERRQ(ierr);
1015       ierr            = PetscMalloc(end*sizeof(int),&sbuf2[index]);CHKERRQ(ierr);
1016       sbuf2_i         = sbuf2[index];
1017       for (j=start; j<end; j++) {
1018         id               = rbuf1_i[j] - rstart;
1019         ncols            = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
1020         sbuf2_i[j]       = ncols;
1021         req_size[index] += ncols;
1022       }
1023       req_source[index] = r_status1[i].MPI_SOURCE;
1024       /* form the header */
1025       sbuf2_i[0]   = req_size[index];
1026       for (j=1; j<start; j++) { sbuf2_i[j] = rbuf1_i[j]; }
1027       ierr = MPI_Isend(sbuf2_i,end,MPI_INT,req_source[index],tag1,comm,s_waits2+i);CHKERRQ(ierr);
1028     }
1029   }
1030   ierr = PetscFree(r_status1);CHKERRQ(ierr);
1031   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
1032 
1033   /*  recv buffer sizes */
1034   /* Receive messages*/
1035 
1036   ierr = PetscMalloc((nrqs+1)*sizeof(int*),&rbuf3);CHKERRQ(ierr);
1037   ierr = PetscMalloc((nrqs+1)*sizeof(MatScalar*),&rbuf4);CHKERRQ(ierr);
1038   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Request),&r_waits3);CHKERRQ(ierr);
1039   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Request),&r_waits4);CHKERRQ(ierr);
1040   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&r_status2);CHKERRQ(ierr);
1041 
1042   for (i=0; i<nrqs; ++i) {
1043     ierr = MPI_Waitany(nrqs,r_waits2,&index,r_status2+i);CHKERRQ(ierr);
1044     ierr = PetscMalloc(rbuf2[index][0]*sizeof(int),&rbuf3[index]);CHKERRQ(ierr);
1045     ierr = PetscMalloc(rbuf2[index][0]*bs2*sizeof(MatScalar),&rbuf4[index]);CHKERRQ(ierr);
1046     ierr = MPI_Irecv(rbuf3[index],rbuf2[index][0],MPI_INT,
1047                      r_status2[i].MPI_SOURCE,tag2,comm,r_waits3+index);CHKERRQ(ierr);
1048     ierr = MPI_Irecv(rbuf4[index],rbuf2[index][0]*bs2,MPIU_MATSCALAR,
1049                      r_status2[i].MPI_SOURCE,tag3,comm,r_waits4+index);CHKERRQ(ierr);
1050   }
1051   ierr = PetscFree(r_status2);CHKERRQ(ierr);
1052   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
1053 
1054   /* Wait on sends1 and sends2 */
1055   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&s_status1);CHKERRQ(ierr);
1056   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Status),&s_status2);CHKERRQ(ierr);
1057 
1058   ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);
1059   ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);
1060   ierr = PetscFree(s_status1);CHKERRQ(ierr);
1061   ierr = PetscFree(s_status2);CHKERRQ(ierr);
1062   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
1063   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
1064 
1065   /* Now allocate buffers for a->j, and send them off */
1066   ierr = PetscMalloc((nrqr+1)*sizeof(int *),&sbuf_aj);CHKERRQ(ierr);
1067   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1068   ierr = PetscMalloc((j+1)*sizeof(int),&sbuf_aj[0]);CHKERRQ(ierr);
1069   for (i=1; i<nrqr; i++)  sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
1070 
1071   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits3);CHKERRQ(ierr);
1072   {
1073      for (i=0; i<nrqr; i++) {
1074       rbuf1_i   = rbuf1[i];
1075       sbuf_aj_i = sbuf_aj[i];
1076       ct1       = 2*rbuf1_i[0] + 1;
1077       ct2       = 0;
1078       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1079         kmax = rbuf1[i][2*j];
1080         for (k=0; k<kmax; k++,ct1++) {
1081           row    = rbuf1_i[ct1] - rstart;
1082           nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
1083           ncols  = nzA + nzB;
1084           cworkA = a_j + a_i[row]; cworkB = b_j + b_i[row];
1085 
1086           /* load the column indices for this row into cols*/
1087           cols  = sbuf_aj_i + ct2;
1088           for (l=0; l<nzB; l++) {
1089             if ((ctmp = bmap[cworkB[l]]) < cstart)  cols[l] = ctmp;
1090             else break;
1091           }
1092           imark = l;
1093           for (l=0; l<nzA; l++)   cols[imark+l] = cstart + cworkA[l];
1094           for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
1095           ct2 += ncols;
1096         }
1097       }
1098       ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPI_INT,req_source[i],tag2,comm,s_waits3+i);CHKERRQ(ierr);
1099     }
1100   }
1101   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&r_status3);CHKERRQ(ierr);
1102   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Status),&s_status3);CHKERRQ(ierr);
1103 
1104   /* Allocate buffers for a->a, and send them off */
1105   ierr = PetscMalloc((nrqr+1)*sizeof(MatScalar *),&sbuf_aa);CHKERRQ(ierr);
1106   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1107   ierr = PetscMalloc((j+1)*bs2*sizeof(MatScalar),&sbuf_aa[0]);CHKERRQ(ierr);
1108   for (i=1; i<nrqr; i++)  sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1109 
1110   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits4);CHKERRQ(ierr);
1111   {
1112     for (i=0; i<nrqr; i++) {
1113       rbuf1_i   = rbuf1[i];
1114       sbuf_aa_i = sbuf_aa[i];
1115       ct1       = 2*rbuf1_i[0]+1;
1116       ct2       = 0;
1117       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1118         kmax = rbuf1_i[2*j];
1119         for (k=0; k<kmax; k++,ct1++) {
1120           row    = rbuf1_i[ct1] - rstart;
1121           nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
1122           ncols  = nzA + nzB;
1123           cworkA = a_j + a_i[row];     cworkB = b_j + b_i[row];
1124           vworkA = a_a + a_i[row]*bs2; vworkB = b_a + b_i[row]*bs2;
1125 
1126           /* load the column values for this row into vals*/
1127           vals  = sbuf_aa_i+ct2*bs2;
1128           for (l=0; l<nzB; l++) {
1129             if ((bmap[cworkB[l]]) < cstart) {
1130               ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1131             }
1132             else break;
1133           }
1134           imark = l;
1135           for (l=0; l<nzA; l++) {
1136             ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1137           }
1138           for (l=imark; l<nzB; l++) {
1139             ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1140           }
1141           ct2 += ncols;
1142         }
1143       }
1144       ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_MATSCALAR,req_source[i],tag3,comm,s_waits4+i);CHKERRQ(ierr);
1145     }
1146   }
1147   ierr = PetscMalloc((nrqs+1)*sizeof(MPI_Status),&r_status4);CHKERRQ(ierr);
1148   ierr = PetscMalloc((nrqr+1)*sizeof(MPI_Status),&s_status4);CHKERRQ(ierr);
1149   ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1150 
1151   /* Form the matrix */
1152   /* create col map */
1153   {
1154     int *icol_i;
1155 #if defined (PETSC_USE_CTABLE)
1156     /* Create row map*/
1157     ierr = PetscMalloc((1+ismax)*sizeof(PetscTable),&colmaps);CHKERRQ(ierr);
1158     for (i=0; i<ismax+1; i++) {
1159       ierr = PetscTableCreate(((i<ismax) ? ncol[i] : ncol[i-1])+1,&colmaps[i]);CHKERRQ(ierr);
1160     }
1161 #else
1162     len     = (1+ismax)*sizeof(int*)+ ismax*c->Nbs*sizeof(int);
1163     ierr    = PetscMalloc(len,&cmap);CHKERRQ(ierr);
1164     cmap[0] = (int *)(cmap + ismax);
1165     ierr    = PetscMemzero(cmap[0],(1+ismax*c->Nbs)*sizeof(int));CHKERRQ(ierr);
1166     for (i=1; i<ismax; i++) { cmap[i] = cmap[i-1] + c->Nbs; }
1167 #endif
1168     for (i=0; i<ismax; i++) {
1169       jmax   = ncol[i];
1170       icol_i = icol[i];
1171 #if defined (PETSC_USE_CTABLE)
1172       lcol1_gcol1 = colmaps[i];
1173       for (j=0; j<jmax; j++) {
1174 	ierr = PetscTableAdd(lcol1_gcol1,icol_i[j]+1,j+1);CHKERRQ(ierr);
1175       }
1176 #else
1177       cmap_i = cmap[i];
1178       for (j=0; j<jmax; j++) {
1179         cmap_i[icol_i[j]] = j+1;
1180       }
1181 #endif
1182     }
1183   }
1184 
1185   /* Create lens which is required for MatCreate... */
1186   for (i=0,j=0; i<ismax; i++) { j += nrow[i]; }
1187   len     = (1+ismax)*sizeof(int*)+ j*sizeof(int);
1188   ierr    = PetscMalloc(len,&lens);CHKERRQ(ierr);
1189   lens[0] = (int *)(lens + ismax);
1190   ierr    = PetscMemzero(lens[0],j*sizeof(int));CHKERRQ(ierr);
1191   for (i=1; i<ismax; i++) { lens[i] = lens[i-1] + nrow[i-1]; }
1192 
1193   /* Update lens from local data */
1194   for (i=0; i<ismax; i++) {
1195     jmax   = nrow[i];
1196 #if defined (PETSC_USE_CTABLE)
1197     lcol1_gcol1 = colmaps[i];
1198 #else
1199     cmap_i = cmap[i];
1200 #endif
1201     irow_i = irow[i];
1202     lens_i = lens[i];
1203     for (j=0; j<jmax; j++) {
1204       row  = irow_i[j];
1205 #if defined (PETSC_USE_CTABLE)
1206       ierr = PetscGetProc(row,size,c->rowners,&proc);CHKERRQ(ierr);
1207 #else
1208       proc = rtable[row];
1209 #endif
1210       if (proc == rank) {
1211         /* Get indices from matA and then from matB */
1212         row    = row - rstart;
1213         nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
1214         cworkA =  a_j + a_i[row]; cworkB = b_j + b_i[row];
1215 #if defined (PETSC_USE_CTABLE)
1216        for (k=0; k<nzA; k++) {
1217 	 ierr = PetscTableFind(lcol1_gcol1,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1218           if (tt) { lens_i[j]++; }
1219         }
1220         for (k=0; k<nzB; k++) {
1221 	  ierr = PetscTableFind(lcol1_gcol1,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1222           if (tt) { lens_i[j]++; }
1223         }
1224 #else
1225         for (k=0; k<nzA; k++) {
1226           if (cmap_i[cstart + cworkA[k]]) { lens_i[j]++; }
1227         }
1228         for (k=0; k<nzB; k++) {
1229           if (cmap_i[bmap[cworkB[k]]]) { lens_i[j]++; }
1230         }
1231 #endif
1232       }
1233     }
1234   }
1235 #if defined (PETSC_USE_CTABLE)
1236   /* Create row map*/
1237   ierr = PetscMalloc((1+ismax)*sizeof(PetscTable),&rowmaps);CHKERRQ(ierr);
1238   for (i=0; i<ismax+1; i++){
1239     ierr = PetscTableCreate((i<ismax) ? nrow[i] : nrow[i-1],&rowmaps[i]);CHKERRQ(ierr);
1240   }
1241 #else
1242   /* Create row map*/
1243   len     = (1+ismax)*sizeof(int*)+ ismax*Mbs*sizeof(int);
1244   ierr    = PetscMalloc(len,&rmap);CHKERRQ(ierr);
1245   rmap[0] = (int *)(rmap + ismax);
1246   ierr    = PetscMemzero(rmap[0],ismax*Mbs*sizeof(int));CHKERRQ(ierr);
1247   for (i=1; i<ismax; i++) { rmap[i] = rmap[i-1] + Mbs;}
1248 #endif
1249   for (i=0; i<ismax; i++) {
1250     irow_i = irow[i];
1251     jmax   = nrow[i];
1252 #if defined (PETSC_USE_CTABLE)
1253     lrow1_grow1 = rowmaps[i];
1254     for (j=0; j<jmax; j++) {
1255       ierr = PetscTableAdd(lrow1_grow1,irow_i[j]+1,j+1);CHKERRQ(ierr);
1256     }
1257 #else
1258     rmap_i = rmap[i];
1259     for (j=0; j<jmax; j++) {
1260       rmap_i[irow_i[j]] = j;
1261     }
1262 #endif
1263   }
1264 
1265   /* Update lens from offproc data */
1266   {
1267     int *rbuf2_i,*rbuf3_i,*sbuf1_i;
1268 
1269     for (tmp2=0; tmp2<nrqs; tmp2++) {
1270       ierr    = MPI_Waitany(nrqs,r_waits3,&i,r_status3+tmp2);CHKERRQ(ierr);
1271       index   = pa[i];
1272       sbuf1_i = sbuf1[index];
1273       jmax    = sbuf1_i[0];
1274       ct1     = 2*jmax+1;
1275       ct2     = 0;
1276       rbuf2_i = rbuf2[i];
1277       rbuf3_i = rbuf3[i];
1278       for (j=1; j<=jmax; j++) {
1279         is_no   = sbuf1_i[2*j-1];
1280         max1    = sbuf1_i[2*j];
1281         lens_i  = lens[is_no];
1282 #if defined (PETSC_USE_CTABLE)
1283 	lcol1_gcol1 = colmaps[is_no];
1284 	lrow1_grow1 = rowmaps[is_no];
1285 #else
1286         cmap_i  = cmap[is_no];
1287 	rmap_i  = rmap[is_no];
1288 #endif
1289         for (k=0; k<max1; k++,ct1++) {
1290 #if defined (PETSC_USE_CTABLE)
1291 	  ierr = PetscTableFind(lrow1_grow1,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
1292           row--;
1293           if(row < 0) { SETERRQ(1,"row not found in table"); }
1294 #else
1295           row  = rmap_i[sbuf1_i[ct1]]; /* the val in the new matrix to be */
1296 #endif
1297           max2 = rbuf2_i[ct1];
1298           for (l=0; l<max2; l++,ct2++) {
1299 #if defined (PETSC_USE_CTABLE)
1300 	    ierr = PetscTableFind(lcol1_gcol1,rbuf3_i[ct2]+1,&tt);CHKERRQ(ierr);
1301 	    if (tt) {
1302               lens_i[row]++;
1303             }
1304 #else
1305             if (cmap_i[rbuf3_i[ct2]]) {
1306               lens_i[row]++;
1307             }
1308 #endif
1309           }
1310         }
1311       }
1312     }
1313   }
1314   ierr = PetscFree(r_status3);CHKERRQ(ierr);
1315   ierr = PetscFree(r_waits3);CHKERRQ(ierr);
1316   ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);
1317   ierr = PetscFree(s_status3);CHKERRQ(ierr);
1318   ierr = PetscFree(s_waits3);CHKERRQ(ierr);
1319 
1320   /* Create the submatrices */
1321   if (scall == MAT_REUSE_MATRIX) {
1322     /*
1323         Assumes new rows are same length as the old rows, hence bug!
1324     */
1325     for (i=0; i<ismax; i++) {
1326       mat = (Mat_SeqBAIJ *)(submats[i]->data);
1327       if ((mat->mbs != nrow[i]) || (mat->nbs != ncol[i] || mat->bs != bs)) {
1328         SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
1329       }
1330       ierr = PetscMemcmp(mat->ilen,lens[i],mat->mbs *sizeof(int),&flag);CHKERRQ(ierr);
1331       if (flag == PETSC_FALSE) {
1332         SETERRQ(PETSC_ERR_ARG_INCOMP,"Cannot reuse matrix. wrong no of nonzeros");
1333       }
1334       /* Initial matrix as if empty */
1335       ierr = PetscMemzero(mat->ilen,mat->mbs*sizeof(int));CHKERRQ(ierr);
1336       submats[i]->factor = C->factor;
1337     }
1338   } else {
1339     for (i=0; i<ismax; i++) {
1340       ierr = MatCreateSeqBAIJ(PETSC_COMM_SELF,a->bs,nrow[i]*bs,ncol[i]*bs,0,lens[i],submats+i);CHKERRQ(ierr);
1341     }
1342   }
1343 
1344   /* Assemble the matrices */
1345   /* First assemble the local rows */
1346   {
1347     int       ilen_row,*imat_ilen,*imat_j,*imat_i;
1348     MatScalar *imat_a;
1349 
1350     for (i=0; i<ismax; i++) {
1351       mat       = (Mat_SeqBAIJ*)submats[i]->data;
1352       imat_ilen = mat->ilen;
1353       imat_j    = mat->j;
1354       imat_i    = mat->i;
1355       imat_a    = mat->a;
1356 
1357 #if defined (PETSC_USE_CTABLE)
1358       lcol1_gcol1 = colmaps[i];
1359       lrow1_grow1 = rowmaps[i];
1360 #else
1361       cmap_i    = cmap[i];
1362       rmap_i    = rmap[i];
1363 #endif
1364       irow_i    = irow[i];
1365       jmax      = nrow[i];
1366       for (j=0; j<jmax; j++) {
1367         row      = irow_i[j];
1368 #if defined (PETSC_USE_CTABLE)
1369 	ierr = PetscGetProc(row,size,c->rowners,&proc);CHKERRQ(ierr);
1370 #else
1371 	proc = rtable[row];
1372 #endif
1373         if (proc == rank) {
1374           row      = row - rstart;
1375           nzA      = a_i[row+1] - a_i[row];
1376           nzB      = b_i[row+1] - b_i[row];
1377           cworkA   = a_j + a_i[row];
1378           cworkB   = b_j + b_i[row];
1379           vworkA   = a_a + a_i[row]*bs2;
1380           vworkB   = b_a + b_i[row]*bs2;
1381 #if defined (PETSC_USE_CTABLE)
1382 	  ierr = PetscTableFind(lrow1_grow1,row+rstart+1,&row);CHKERRQ(ierr);
1383           row--;
1384           if (row < 0) { SETERRQ(1,"row not found in table"); }
1385 #else
1386           row      = rmap_i[row + rstart];
1387 #endif
1388           mat_i    = imat_i[row];
1389           mat_a    = imat_a + mat_i*bs2;
1390           mat_j    = imat_j + mat_i;
1391           ilen_row = imat_ilen[row];
1392 
1393           /* load the column indices for this row into cols*/
1394           for (l=0; l<nzB; l++) {
1395 	    if ((ctmp = bmap[cworkB[l]]) < cstart) {
1396 #if defined (PETSC_USE_CTABLE)
1397 	      ierr = PetscTableFind(lcol1_gcol1,ctmp+1,&tcol);CHKERRQ(ierr);
1398 	      if (tcol) {
1399 #else
1400               if ((tcol = cmap_i[ctmp])) {
1401 #endif
1402                 *mat_j++ = tcol - 1;
1403                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1404                 mat_a   += bs2;
1405                 ilen_row++;
1406               }
1407             } else break;
1408           }
1409           imark = l;
1410           for (l=0; l<nzA; l++) {
1411 #if defined (PETSC_USE_CTABLE)
1412 	    ierr = PetscTableFind(lcol1_gcol1,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
1413 	    if (tcol) {
1414 #else
1415 	    if ((tcol = cmap_i[cstart + cworkA[l]])) {
1416 #endif
1417               *mat_j++ = tcol - 1;
1418               ierr     = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1419               mat_a   += bs2;
1420               ilen_row++;
1421             }
1422           }
1423           for (l=imark; l<nzB; l++) {
1424 #if defined (PETSC_USE_CTABLE)
1425 	    ierr = PetscTableFind(lcol1_gcol1,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
1426 	    if (tcol) {
1427 #else
1428             if ((tcol = cmap_i[bmap[cworkB[l]]])) {
1429 #endif
1430               *mat_j++ = tcol - 1;
1431               ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1432               mat_a   += bs2;
1433               ilen_row++;
1434             }
1435           }
1436           imat_ilen[row] = ilen_row;
1437         }
1438       }
1439 
1440     }
1441   }
1442 
1443   /*   Now assemble the off proc rows*/
1444   {
1445     int       *sbuf1_i,*rbuf2_i,*rbuf3_i,*imat_ilen,ilen;
1446     int       *imat_j,*imat_i;
1447     MatScalar *imat_a,*rbuf4_i;
1448 
1449     for (tmp2=0; tmp2<nrqs; tmp2++) {
1450       ierr    = MPI_Waitany(nrqs,r_waits4,&i,r_status4+tmp2);CHKERRQ(ierr);
1451       index   = pa[i];
1452       sbuf1_i = sbuf1[index];
1453       jmax    = sbuf1_i[0];
1454       ct1     = 2*jmax + 1;
1455       ct2     = 0;
1456       rbuf2_i = rbuf2[i];
1457       rbuf3_i = rbuf3[i];
1458       rbuf4_i = rbuf4[i];
1459       for (j=1; j<=jmax; j++) {
1460         is_no     = sbuf1_i[2*j-1];
1461 #if defined (PETSC_USE_CTABLE)
1462 	lrow1_grow1 = rowmaps[is_no];
1463 	lcol1_gcol1 = colmaps[is_no];
1464 #else
1465         rmap_i    = rmap[is_no];
1466         cmap_i    = cmap[is_no];
1467 #endif
1468         mat       = (Mat_SeqBAIJ*)submats[is_no]->data;
1469         imat_ilen = mat->ilen;
1470         imat_j    = mat->j;
1471         imat_i    = mat->i;
1472         imat_a    = mat->a;
1473         max1      = sbuf1_i[2*j];
1474         for (k=0; k<max1; k++,ct1++) {
1475           row   = sbuf1_i[ct1];
1476 #if defined (PETSC_USE_CTABLE)
1477 	  ierr = PetscTableFind(lrow1_grow1,row+1,&row);CHKERRQ(ierr);
1478           row--;
1479           if(row < 0) { SETERRQ(1,"row not found in table"); }
1480 #else
1481           row   = rmap_i[row];
1482 #endif
1483           ilen  = imat_ilen[row];
1484           mat_i = imat_i[row];
1485           mat_a = imat_a + mat_i*bs2;
1486           mat_j = imat_j + mat_i;
1487           max2 = rbuf2_i[ct1];
1488           for (l=0; l<max2; l++,ct2++) {
1489 #if defined (PETSC_USE_CTABLE)
1490 	    ierr = PetscTableFind(lcol1_gcol1,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1491 	    if (tcol) {
1492 #else
1493 	    if ((tcol = cmap_i[rbuf3_i[ct2]])) {
1494 #endif
1495               *mat_j++    = tcol - 1;
1496               /* *mat_a++= rbuf4_i[ct2]; */
1497               ierr        = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1498               mat_a      += bs2;
1499               ilen++;
1500             }
1501           }
1502           imat_ilen[row] = ilen;
1503         }
1504       }
1505     }
1506   }
1507   ierr = PetscFree(r_status4);CHKERRQ(ierr);
1508   ierr = PetscFree(r_waits4);CHKERRQ(ierr);
1509   ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);
1510   ierr = PetscFree(s_waits4);CHKERRQ(ierr);
1511   ierr = PetscFree(s_status4);CHKERRQ(ierr);
1512 
1513   /* Restore the indices */
1514   for (i=0; i<ismax; i++) {
1515     ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
1516     ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
1517   }
1518 
1519   /* Destroy allocated memory */
1520   ierr = PetscFree(irow);CHKERRQ(ierr);
1521   ierr = PetscFree(w1);CHKERRQ(ierr);
1522   ierr = PetscFree(pa);CHKERRQ(ierr);
1523 
1524   ierr = PetscFree(sbuf1);CHKERRQ(ierr);
1525   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
1526   for (i=0; i<nrqr; ++i) {
1527     ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
1528   }
1529   for (i=0; i<nrqs; ++i) {
1530     ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
1531     ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);
1532   }
1533 
1534   ierr = PetscFree(sbuf2);CHKERRQ(ierr);
1535   ierr = PetscFree(rbuf3);CHKERRQ(ierr);
1536   ierr = PetscFree(rbuf4);CHKERRQ(ierr);
1537   ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
1538   ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
1539   ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
1540   ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
1541 
1542 #if defined (PETSC_USE_CTABLE)
1543   for (i=0; i<ismax+1; i++){
1544     ierr = PetscTableDelete(rowmaps[i]);CHKERRQ(ierr);
1545     ierr = PetscTableDelete(colmaps[i]);CHKERRQ(ierr);
1546   }
1547   ierr = PetscFree(colmaps);CHKERRQ(ierr);
1548   ierr = PetscFree(rowmaps);CHKERRQ(ierr);
1549   /* Mark Adams */
1550 #else
1551   ierr = PetscFree(rmap);CHKERRQ(ierr);
1552   ierr = PetscFree(cmap);CHKERRQ(ierr);
1553 #endif
1554   ierr = PetscFree(lens);CHKERRQ(ierr);
1555 
1556   for (i=0; i<ismax; i++) {
1557     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1558     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1559   }
1560 
1561   PetscFunctionReturn(0);
1562 }
1563 
1564