xref: /petsc/src/mat/impls/baij/mpi/baijov.c (revision 1abc2f7b6f630c0f5b0901d1c601cff403cec83b)
1 
2 /*
3    Routines to compute overlapping regions of a parallel MPI matrix
4   and to find submatrices that were shared across processors.
5 */
6 #include <../src/mat/impls/baij/mpi/mpibaij.h>
7 #include <petscbt.h>
8 
9 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat,PetscInt,char**,PetscInt*,PetscInt**);
10 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat,PetscInt,PetscInt**,PetscInt**,PetscInt*);
11 extern PetscErrorCode MatGetRow_MPIBAIJ(Mat,PetscInt,PetscInt*,PetscInt**,PetscScalar**);
12 extern PetscErrorCode MatRestoreRow_MPIBAIJ(Mat,PetscInt,PetscInt*,PetscInt**,PetscScalar**);
13 
14 PetscErrorCode MatIncreaseOverlap_MPIBAIJ(Mat C,PetscInt imax,IS is[],PetscInt ov)
15 {
16   PetscErrorCode ierr;
17   PetscInt       i,N=C->cmap->N, bs=C->rmap->bs;
18   IS             *is_new;
19 
20   PetscFunctionBegin;
21   ierr = PetscMalloc1(imax,&is_new);CHKERRQ(ierr);
22   /* Convert the indices into block format */
23   ierr = ISCompressIndicesGeneral(N,C->rmap->n,bs,imax,is,is_new);CHKERRQ(ierr);
24   if (ov < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap specified\n");
25   for (i=0; i<ov; ++i) {
26     ierr = MatIncreaseOverlap_MPIBAIJ_Once(C,imax,is_new);CHKERRQ(ierr);
27   }
28   for (i=0; i<imax; i++) {ierr = ISDestroy(&is[i]);CHKERRQ(ierr);}
29   ierr = ISExpandIndicesGeneral(N,N,bs,imax,is_new,is);CHKERRQ(ierr);
30   for (i=0; i<imax; i++) {ierr = ISDestroy(&is_new[i]);CHKERRQ(ierr);}
31   ierr = PetscFree(is_new);CHKERRQ(ierr);
32   PetscFunctionReturn(0);
33 }
34 
35 /*
36   Sample message format:
37   If a processor A wants processor B to process some elements corresponding
38   to index sets is[1], is[5]
39   mesg [0] = 2   (no of index sets in the mesg)
40   -----------
41   mesg [1] = 1 => is[1]
42   mesg [2] = sizeof(is[1]);
43   -----------
44   mesg [5] = 5  => is[5]
45   mesg [6] = sizeof(is[5]);
46   -----------
47   mesg [7]
48   mesg [n]  data(is[1])
49   -----------
50   mesg[n+1]
51   mesg[m]  data(is[5])
52   -----------
53 
54   Notes:
55   nrqs - no of requests sent (or to be sent out)
56   nrqr - no of requests recieved (which have to be or which have been processed
57 */
58 PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Once(Mat C,PetscInt imax,IS is[])
59 {
60   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
61   const PetscInt **idx,*idx_i;
62   PetscInt       *n,*w3,*w4,**data,len;
63   PetscErrorCode ierr;
64   PetscMPIInt    size,rank,tag1,tag2,*w2,*w1,nrqr;
65   PetscInt       Mbs,i,j,k,**rbuf,row,proc=-1,nrqs,msz,**outdat,**ptr;
66   PetscInt       *ctr,*pa,*tmp,*isz,*isz1,**xdata,**rbuf2,*d_p;
67   PetscMPIInt    *onodes1,*olengths1,*onodes2,*olengths2;
68   PetscBT        *table;
69   MPI_Comm       comm;
70   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2;
71   MPI_Status     *s_status,*recv_status;
72   char           *t_p;
73 
74   PetscFunctionBegin;
75   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
76   size = c->size;
77   rank = c->rank;
78   Mbs  = c->Mbs;
79 
80   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
81   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
82 
83   ierr = PetscMalloc2(imax+1,&idx,imax,&n);CHKERRQ(ierr);
84 
85   for (i=0; i<imax; i++) {
86     ierr = ISGetIndices(is[i],&idx[i]);CHKERRQ(ierr);
87     ierr = ISGetLocalSize(is[i],&n[i]);CHKERRQ(ierr);
88   }
89 
90   /* evaluate communication - mesg to who,length of mesg, and buffer space
91      required. Based on this, buffers are allocated, and data copied into them*/
92   ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);
93   for (i=0; i<imax; i++) {
94     ierr  = PetscMemzero(w4,size*sizeof(PetscInt));CHKERRQ(ierr); /* initialise work vector*/
95     idx_i = idx[i];
96     len   = n[i];
97     for (j=0; j<len; j++) {
98       row = idx_i[j];
99       if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index set cannot have negative entries");
100       ierr = PetscLayoutFindOwner(C->rmap,row*C->rmap->bs,&proc);CHKERRQ(ierr);
101       w4[proc]++;
102     }
103     for (j=0; j<size; j++) {
104       if (w4[j]) { w1[j] += w4[j]; w3[j]++;}
105     }
106   }
107 
108   nrqs     = 0;              /* no of outgoing messages */
109   msz      = 0;              /* total mesg length (for all proc */
110   w1[rank] = 0;              /* no mesg sent to itself */
111   w3[rank] = 0;
112   for (i=0; i<size; i++) {
113     if (w1[i])  {w2[i] = 1; nrqs++;} /* there exists a message to proc i */
114   }
115   /* pa - is list of processors to communicate with */
116   ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr);
117   for (i=0,j=0; i<size; i++) {
118     if (w1[i]) {pa[j] = i; j++;}
119   }
120 
121   /* Each message would have a header = 1 + 2*(no of IS) + data */
122   for (i=0; i<nrqs; i++) {
123     j      = pa[i];
124     w1[j] += w2[j] + 2*w3[j];
125     msz   += w1[j];
126   }
127 
128   /* Determine the number of messages to expect, their lengths, from from-ids */
129   ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
130   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
131 
132   /* Now post the Irecvs corresponding to these messages */
133   ierr = PetscPostIrecvInt(comm,tag1,nrqr,onodes1,olengths1,&rbuf,&r_waits1);CHKERRQ(ierr);
134 
135   /* Allocate Memory for outgoing messages */
136   ierr = PetscMalloc4(size,&outdat,size,&ptr,msz,&tmp,size,&ctr);CHKERRQ(ierr);
137   ierr = PetscMemzero(outdat,size*sizeof(PetscInt*));CHKERRQ(ierr);
138   ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
139   {
140     PetscInt *iptr = tmp,ict  = 0;
141     for (i=0; i<nrqs; i++) {
142       j         = pa[i];
143       iptr     +=  ict;
144       outdat[j] = iptr;
145       ict       = w1[j];
146     }
147   }
148 
149   /* Form the outgoing messages */
150   /*plug in the headers*/
151   for (i=0; i<nrqs; i++) {
152     j            = pa[i];
153     outdat[j][0] = 0;
154     ierr         = PetscMemzero(outdat[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
155     ptr[j]       = outdat[j] + 2*w3[j] + 1;
156   }
157 
158   /* Memory for doing local proc's work*/
159   {
160     ierr = PetscCalloc5(imax,&table, imax,&data, imax,&isz, Mbs*imax,&d_p, (Mbs/PETSC_BITS_PER_BYTE+1)*imax,&t_p);CHKERRQ(ierr);
161 
162     for (i=0; i<imax; i++) {
163       table[i] = t_p + (Mbs/PETSC_BITS_PER_BYTE+1)*i;
164       data[i]  = d_p + (Mbs)*i;
165     }
166   }
167 
168   /* Parse the IS and update local tables and the outgoing buf with the data*/
169   {
170     PetscInt n_i,*data_i,isz_i,*outdat_j,ctr_j;
171     PetscBT  table_i;
172 
173     for (i=0; i<imax; i++) {
174       ierr    = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
175       n_i     = n[i];
176       table_i = table[i];
177       idx_i   = idx[i];
178       data_i  = data[i];
179       isz_i   = isz[i];
180       for (j=0; j<n_i; j++) {   /* parse the indices of each IS */
181         row  = idx_i[j];
182         ierr = PetscLayoutFindOwner(C->rmap,row*C->rmap->bs,&proc);CHKERRQ(ierr);
183         if (proc != rank) { /* copy to the outgoing buffer */
184           ctr[proc]++;
185           *ptr[proc] = row;
186           ptr[proc]++;
187         } else { /* Update the local table */
188           if (!PetscBTLookupSet(table_i,row)) data_i[isz_i++] = row;
189         }
190       }
191       /* Update the headers for the current IS */
192       for (j=0; j<size; j++) { /* Can Optimise this loop by using pa[] */
193         if ((ctr_j = ctr[j])) {
194           outdat_j        = outdat[j];
195           k               = ++outdat_j[0];
196           outdat_j[2*k]   = ctr_j;
197           outdat_j[2*k-1] = i;
198         }
199       }
200       isz[i] = isz_i;
201     }
202   }
203 
204   /*  Now  post the sends */
205   ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
206   for (i=0; i<nrqs; ++i) {
207     j    = pa[i];
208     ierr = MPI_Isend(outdat[j],w1[j],MPIU_INT,j,tag1,comm,s_waits1+i);CHKERRQ(ierr);
209   }
210 
211   /* No longer need the original indices*/
212   for (i=0; i<imax; ++i) {
213     ierr = ISRestoreIndices(is[i],idx+i);CHKERRQ(ierr);
214   }
215   ierr = PetscFree2(idx,n);CHKERRQ(ierr);
216 
217   for (i=0; i<imax; ++i) {
218     ierr = ISDestroy(&is[i]);CHKERRQ(ierr);
219   }
220 
221   /* Do Local work*/
222   ierr = MatIncreaseOverlap_MPIBAIJ_Local(C,imax,table,isz,data);CHKERRQ(ierr);
223 
224   /* Receive messages*/
225   ierr = PetscMalloc1(nrqr+1,&recv_status);CHKERRQ(ierr);
226   if (nrqr) {ierr = MPI_Waitall(nrqr,r_waits1,recv_status);CHKERRQ(ierr);}
227 
228   ierr = PetscMalloc1(nrqs+1,&s_status);CHKERRQ(ierr);
229   if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status);CHKERRQ(ierr);}
230 
231   /* Phase 1 sends are complete - deallocate buffers */
232   ierr = PetscFree4(outdat,ptr,tmp,ctr);CHKERRQ(ierr);
233   ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
234 
235   ierr = PetscMalloc1(nrqr+1,&xdata);CHKERRQ(ierr);
236   ierr = PetscMalloc1(nrqr+1,&isz1);CHKERRQ(ierr);
237   ierr = MatIncreaseOverlap_MPIBAIJ_Receive(C,nrqr,rbuf,xdata,isz1);CHKERRQ(ierr);
238   ierr = PetscFree(rbuf[0]);CHKERRQ(ierr);
239   ierr = PetscFree(rbuf);CHKERRQ(ierr);
240 
241   /* Send the data back*/
242   /* Do a global reduction to know the buffer space req for incoming messages*/
243   {
244     PetscMPIInt *rw1;
245 
246     ierr = PetscCalloc1(size,&rw1);CHKERRQ(ierr);
247 
248     for (i=0; i<nrqr; ++i) {
249       proc = recv_status[i].MPI_SOURCE;
250       if (proc != onodes1[i]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPI_SOURCE mismatch");
251       rw1[proc] = isz1[i];
252     }
253 
254     ierr = PetscFree(onodes1);CHKERRQ(ierr);
255     ierr = PetscFree(olengths1);CHKERRQ(ierr);
256 
257     /* Determine the number of messages to expect, their lengths, from from-ids */
258     ierr = PetscGatherMessageLengths(comm,nrqr,nrqs,rw1,&onodes2,&olengths2);CHKERRQ(ierr);
259     ierr = PetscFree(rw1);CHKERRQ(ierr);
260   }
261   /* Now post the Irecvs corresponding to these messages */
262   ierr = PetscPostIrecvInt(comm,tag2,nrqs,onodes2,olengths2,&rbuf2,&r_waits2);CHKERRQ(ierr);
263 
264   /*  Now  post the sends */
265   ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
266   for (i=0; i<nrqr; ++i) {
267     j    = recv_status[i].MPI_SOURCE;
268     ierr = MPI_Isend(xdata[i],isz1[i],MPIU_INT,j,tag2,comm,s_waits2+i);CHKERRQ(ierr);
269   }
270 
271   /* receive work done on other processors*/
272   {
273     PetscMPIInt idex;
274     PetscInt    is_no,ct1,max,*rbuf2_i,isz_i,*data_i,jmax;
275     PetscBT     table_i;
276     MPI_Status  *status2;
277 
278     ierr = PetscMalloc1(PetscMax(nrqr,nrqs)+1,&status2);CHKERRQ(ierr);
279     for (i=0; i<nrqs; ++i) {
280       ierr = MPI_Waitany(nrqs,r_waits2,&idex,status2+i);CHKERRQ(ierr);
281       /* Process the message*/
282       rbuf2_i = rbuf2[idex];
283       ct1     = 2*rbuf2_i[0]+1;
284       jmax    = rbuf2[idex][0];
285       for (j=1; j<=jmax; j++) {
286         max     = rbuf2_i[2*j];
287         is_no   = rbuf2_i[2*j-1];
288         isz_i   = isz[is_no];
289         data_i  = data[is_no];
290         table_i = table[is_no];
291         for (k=0; k<max; k++,ct1++) {
292           row = rbuf2_i[ct1];
293           if (!PetscBTLookupSet(table_i,row)) data_i[isz_i++] = row;
294         }
295         isz[is_no] = isz_i;
296       }
297     }
298     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,status2);CHKERRQ(ierr);}
299     ierr = PetscFree(status2);CHKERRQ(ierr);
300   }
301 
302   for (i=0; i<imax; ++i) {
303     ierr = ISCreateGeneral(PETSC_COMM_SELF,isz[i],data[i],PETSC_COPY_VALUES,is+i);CHKERRQ(ierr);
304   }
305 
306 
307   ierr = PetscFree(onodes2);CHKERRQ(ierr);
308   ierr = PetscFree(olengths2);CHKERRQ(ierr);
309 
310   ierr = PetscFree(pa);CHKERRQ(ierr);
311   ierr = PetscFree(rbuf2[0]);CHKERRQ(ierr);
312   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
313   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
314   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
315   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
316   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
317   ierr = PetscFree5(table,data,isz,d_p,t_p);CHKERRQ(ierr);
318   ierr = PetscFree(s_status);CHKERRQ(ierr);
319   ierr = PetscFree(recv_status);CHKERRQ(ierr);
320   ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
321   ierr = PetscFree(xdata);CHKERRQ(ierr);
322   ierr = PetscFree(isz1);CHKERRQ(ierr);
323   PetscFunctionReturn(0);
324 }
325 
326 /*
327    MatIncreaseOverlap_MPIBAIJ_Local - Called by MatincreaseOverlap, to do
328        the work on the local processor.
329 
330      Inputs:
331       C      - MAT_MPIBAIJ;
332       imax - total no of index sets processed at a time;
333       table  - an array of char - size = Mbs bits.
334 
335      Output:
336       isz    - array containing the count of the solution elements corresponding
337                to each index set;
338       data   - pointer to the solutions
339 */
340 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat C,PetscInt imax,PetscBT *table,PetscInt *isz,PetscInt **data)
341 {
342   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
343   Mat         A  = c->A,B = c->B;
344   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
345   PetscInt    start,end,val,max,rstart,cstart,*ai,*aj;
346   PetscInt    *bi,*bj,*garray,i,j,k,row,*data_i,isz_i;
347   PetscBT     table_i;
348 
349   PetscFunctionBegin;
350   rstart = c->rstartbs;
351   cstart = c->cstartbs;
352   ai     = a->i;
353   aj     = a->j;
354   bi     = b->i;
355   bj     = b->j;
356   garray = c->garray;
357 
358 
359   for (i=0; i<imax; i++) {
360     data_i  = data[i];
361     table_i = table[i];
362     isz_i   = isz[i];
363     for (j=0,max=isz[i]; j<max; j++) {
364       row   = data_i[j] - rstart;
365       start = ai[row];
366       end   = ai[row+1];
367       for (k=start; k<end; k++) { /* Amat */
368         val = aj[k] + cstart;
369         if (!PetscBTLookupSet(table_i,val)) data_i[isz_i++] = val;
370       }
371       start = bi[row];
372       end   = bi[row+1];
373       for (k=start; k<end; k++) { /* Bmat */
374         val = garray[bj[k]];
375         if (!PetscBTLookupSet(table_i,val)) data_i[isz_i++] = val;
376       }
377     }
378     isz[i] = isz_i;
379   }
380   PetscFunctionReturn(0);
381 }
382 /*
383       MatIncreaseOverlap_MPIBAIJ_Receive - Process the recieved messages,
384          and return the output
385 
386          Input:
387            C    - the matrix
388            nrqr - no of messages being processed.
389            rbuf - an array of pointers to the recieved requests
390 
391          Output:
392            xdata - array of messages to be sent back
393            isz1  - size of each message
394 
395   For better efficiency perhaps we should malloc separately each xdata[i],
396 then if a remalloc is required we need only copy the data for that one row
397 rather than all previous rows as it is now where a single large chunck of
398 memory is used.
399 
400 */
401 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat C,PetscInt nrqr,PetscInt **rbuf,PetscInt **xdata,PetscInt * isz1)
402 {
403   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
404   Mat            A  = c->A,B = c->B;
405   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
406   PetscErrorCode ierr;
407   PetscInt       rstart,cstart,*ai,*aj,*bi,*bj,*garray,i,j,k;
408   PetscInt       row,total_sz,ct,ct1,ct2,ct3,mem_estimate,oct2,l,start,end;
409   PetscInt       val,max1,max2,Mbs,no_malloc =0,*tmp,new_estimate,ctr;
410   PetscInt       *rbuf_i,kmax,rbuf_0;
411   PetscBT        xtable;
412 
413   PetscFunctionBegin;
414   Mbs    = c->Mbs;
415   rstart = c->rstartbs;
416   cstart = c->cstartbs;
417   ai     = a->i;
418   aj     = a->j;
419   bi     = b->i;
420   bj     = b->j;
421   garray = c->garray;
422 
423 
424   for (i=0,ct=0,total_sz=0; i<nrqr; ++i) {
425     rbuf_i =  rbuf[i];
426     rbuf_0 =  rbuf_i[0];
427     ct    += rbuf_0;
428     for (j=1; j<=rbuf_0; j++) total_sz += rbuf_i[2*j];
429   }
430 
431   if (c->Mbs) max1 = ct*(a->nz +b->nz)/c->Mbs;
432   else        max1 = 1;
433   mem_estimate = 3*((total_sz > max1 ? total_sz : max1)+1);
434   ierr         = PetscMalloc1(mem_estimate,&xdata[0]);CHKERRQ(ierr);
435   ++no_malloc;
436   ierr = PetscBTCreate(Mbs,&xtable);CHKERRQ(ierr);
437   ierr = PetscMemzero(isz1,nrqr*sizeof(PetscInt));CHKERRQ(ierr);
438 
439   ct3 = 0;
440   for (i=0; i<nrqr; i++) { /* for easch mesg from proc i */
441     rbuf_i =  rbuf[i];
442     rbuf_0 =  rbuf_i[0];
443     ct1    =  2*rbuf_0+1;
444     ct2    =  ct1;
445     ct3   += ct1;
446     for (j=1; j<=rbuf_0; j++) { /* for each IS from proc i*/
447       ierr = PetscBTMemzero(Mbs,xtable);CHKERRQ(ierr);
448       oct2 = ct2;
449       kmax = rbuf_i[2*j];
450       for (k=0; k<kmax; k++,ct1++) {
451         row = rbuf_i[ct1];
452         if (!PetscBTLookupSet(xtable,row)) {
453           if (!(ct3 < mem_estimate)) {
454             new_estimate = (PetscInt)(1.5*mem_estimate)+1;
455             ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
456             ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
457             ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
458             xdata[0]     = tmp;
459             mem_estimate = new_estimate; ++no_malloc;
460             for (ctr=1; ctr<=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
461           }
462           xdata[i][ct2++] = row;
463           ct3++;
464         }
465       }
466       for (k=oct2,max2=ct2; k<max2; k++)  {
467         row   = xdata[i][k] - rstart;
468         start = ai[row];
469         end   = ai[row+1];
470         for (l=start; l<end; l++) {
471           val = aj[l] + cstart;
472           if (!PetscBTLookupSet(xtable,val)) {
473             if (!(ct3 < mem_estimate)) {
474               new_estimate = (PetscInt)(1.5*mem_estimate)+1;
475               ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
476               ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
477               ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
478               xdata[0]     = tmp;
479               mem_estimate = new_estimate; ++no_malloc;
480               for (ctr=1; ctr<=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
481             }
482             xdata[i][ct2++] = val;
483             ct3++;
484           }
485         }
486         start = bi[row];
487         end   = bi[row+1];
488         for (l=start; l<end; l++) {
489           val = garray[bj[l]];
490           if (!PetscBTLookupSet(xtable,val)) {
491             if (!(ct3 < mem_estimate)) {
492               new_estimate = (PetscInt)(1.5*mem_estimate)+1;
493               ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
494               ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
495               ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
496               xdata[0]     = tmp;
497               mem_estimate = new_estimate; ++no_malloc;
498               for (ctr =1; ctr <=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
499             }
500             xdata[i][ct2++] = val;
501             ct3++;
502           }
503         }
504       }
505       /* Update the header*/
506       xdata[i][2*j]   = ct2 - oct2; /* Undo the vector isz1 and use only a var*/
507       xdata[i][2*j-1] = rbuf_i[2*j-1];
508     }
509     xdata[i][0] = rbuf_0;
510     xdata[i+1]  = xdata[i] + ct2;
511     isz1[i]     = ct2; /* size of each message */
512   }
513   ierr = PetscBTDestroy(&xtable);CHKERRQ(ierr);
514   ierr = PetscInfo3(C,"Allocated %D bytes, required %D, no of mallocs = %D\n",mem_estimate,ct3,no_malloc);CHKERRQ(ierr);
515   PetscFunctionReturn(0);
516 }
517 
518 PetscErrorCode MatGetSubMatrices_MPIBAIJ(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,Mat *submat[])
519 {
520   IS             *isrow_block,*iscol_block;
521   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
522   PetscErrorCode ierr;
523   PetscInt       nmax,nstages_local,nstages,i,pos,max_no,ncol,nrow,N=C->cmap->N,bs=C->rmap->bs;
524   PetscBool      colflag,*allcolumns,*allrows;
525 
526   PetscFunctionBegin;
527   //printf("MatGetSubMatrices_MPIBAIJ scall %d, bs %d\n",scall,bs);
528   /* The compression and expansion should be avoided. Doesn't point
529      out errors, might change the indices, hence buggey */
530   ierr = PetscMalloc2(ismax+1,&isrow_block,ismax+1,&iscol_block);CHKERRQ(ierr);
531   ierr = ISCompressIndicesGeneral(N,C->rmap->n,bs,ismax,isrow,isrow_block);CHKERRQ(ierr);
532   ierr = ISCompressIndicesGeneral(N,C->cmap->n,bs,ismax,iscol,iscol_block);CHKERRQ(ierr);
533 
534   /* Check for special case: each processor gets entire matrix columns -- rm! */
535   ierr = PetscMalloc2(ismax+1,&allcolumns,ismax+1,&allrows);CHKERRQ(ierr);
536   for (i=0; i<ismax; i++) {
537     ierr = ISIdentity(iscol[i],&colflag);CHKERRQ(ierr);
538     ierr = ISGetLocalSize(iscol[i],&ncol);CHKERRQ(ierr);
539     if (colflag && ncol == C->cmap->N) allcolumns[i] = PETSC_TRUE;
540     else allcolumns[i] = PETSC_FALSE;
541 
542     ierr = ISIdentity(isrow[i],&colflag);CHKERRQ(ierr);
543     ierr = ISGetLocalSize(isrow[i],&nrow);CHKERRQ(ierr);
544     if (colflag && nrow == C->rmap->N) allrows[i] = PETSC_TRUE;
545     else allrows[i] = PETSC_FALSE;
546   }
547 
548   /* Allocate memory to hold all the submatrices */
549   if (scall == MAT_INITIAL_MATRIX) {
550     ierr = PetscMalloc1(ismax+1,submat);CHKERRQ(ierr);
551   }
552   /* Determine the number of stages through which submatrices are done */
553   nmax = 20*1000000 / (c->Nbs * sizeof(PetscInt));
554   if (!nmax) nmax = 1;
555   nstages_local = ismax/nmax + ((ismax % nmax) ? 1 : 0);
556 
557   /* Make sure every processor loops through the nstages */
558   ierr = MPIU_Allreduce(&nstages_local,&nstages,1,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)C));CHKERRQ(ierr);
559   for (i=0,pos=0; i<nstages; i++) {
560     if (pos+nmax <= ismax) max_no = nmax;
561     else if (pos == ismax) max_no = 0;
562     else                   max_no = ismax-pos;
563 
564     PetscBool isbaij;
565     ierr = PetscObjectTypeCompare((PetscObject)C,MATMPIBAIJ,&isbaij);CHKERRQ(ierr);
566     if (isbaij) {
567       ierr = MatGetSubMatrices_MPIBAIJ_local_new(C,max_no,isrow_block+pos,iscol_block+pos,scall,allrows+pos,allcolumns+pos,*submat+pos);CHKERRQ(ierr);
568     } else {
569       ierr = MatGetSubMatrices_MPIBAIJ_local(C,max_no,isrow_block+pos,iscol_block+pos,scall,allrows+pos,allcolumns+pos,*submat+pos);CHKERRQ(ierr);
570     }
571     pos += max_no;
572   }
573 
574   for (i=0; i<ismax; i++) {
575     ierr = ISDestroy(&isrow_block[i]);CHKERRQ(ierr);
576     ierr = ISDestroy(&iscol_block[i]);CHKERRQ(ierr);
577   }
578   ierr = PetscFree2(isrow_block,iscol_block);CHKERRQ(ierr);
579   ierr = PetscFree2(allcolumns,allrows);CHKERRQ(ierr);
580   PetscFunctionReturn(0);
581 }
582 
583 #if defined(PETSC_USE_CTABLE)
584 PetscErrorCode PetscGetProc(const PetscInt row, const PetscMPIInt size, const PetscInt proc_gnode[], PetscMPIInt *rank)
585 {
586   PetscInt       nGlobalNd = proc_gnode[size];
587   PetscMPIInt    fproc;
588   PetscErrorCode ierr;
589 
590   PetscFunctionBegin;
591   ierr = PetscMPIIntCast((PetscInt)(((float)row * (float)size / (float)nGlobalNd + 0.5)),&fproc);CHKERRQ(ierr);
592   if (fproc > size) fproc = size;
593   while (row < proc_gnode[fproc] || row >= proc_gnode[fproc+1]) {
594     if (row < proc_gnode[fproc]) fproc--;
595     else                         fproc++;
596   }
597   *rank = fproc;
598   PetscFunctionReturn(0);
599 }
600 #endif
601 
602 /* -------------------------------------------------------------------------*/
603 /* This code is used for BAIJ and SBAIJ matrices (unfortunate dependency) */
604 
605 PetscErrorCode MatDestroy_MPIBAIJ_MatGetSubmatrices(Mat C)
606 {
607   PetscErrorCode ierr;
608   Mat_SeqBAIJ    *c = (Mat_SeqBAIJ*)C->data;
609   Mat_SubMat     *submatj = c->submatis1;
610   PetscInt       i;
611 
612   PetscFunctionBegin;
613   if (!submatj->id) { /* delete data that are linked only to submats[id=0] */
614     ierr = PetscFree4(submatj->sbuf1,submatj->ptr,submatj->tmp,submatj->ctr);CHKERRQ(ierr);
615 
616     for (i=0; i<submatj->nrqr; ++i) {
617       ierr = PetscFree(submatj->sbuf2[i]);CHKERRQ(ierr);
618     }
619     ierr = PetscFree3(submatj->sbuf2,submatj->req_size,submatj->req_source1);CHKERRQ(ierr);
620 
621     if (submatj->rbuf1) {
622       ierr = PetscFree(submatj->rbuf1[0]);CHKERRQ(ierr);
623       ierr = PetscFree(submatj->rbuf1);CHKERRQ(ierr);
624     }
625 
626     for (i=0; i<submatj->nrqs; ++i) {
627       ierr = PetscFree(submatj->rbuf3[i]);CHKERRQ(ierr);
628     }
629     ierr = PetscFree3(submatj->req_source2,submatj->rbuf2,submatj->rbuf3);CHKERRQ(ierr);
630     ierr = PetscFree(submatj->pa);CHKERRQ(ierr);
631   }
632 
633 #if defined(PETSC_USE_CTABLE)
634   ierr = PetscTableDestroy((PetscTable*)&submatj->rmap);CHKERRQ(ierr);
635   if (submatj->cmap_loc) {ierr = PetscFree(submatj->cmap_loc);CHKERRQ(ierr);}
636   ierr = PetscFree(submatj->rmap_loc);CHKERRQ(ierr);
637 #else
638   ierr = PetscFree(submatj->rmap);CHKERRQ(ierr);
639 #endif
640 
641   if (!submatj->allcolumns) {
642 #if defined(PETSC_USE_CTABLE)
643     ierr = PetscTableDestroy((PetscTable*)&submatj->cmap);CHKERRQ(ierr);
644 #else
645     ierr = PetscFree(submatj->cmap);CHKERRQ(ierr);
646 #endif
647   }
648   ierr = submatj->destroy(C);CHKERRQ(ierr);
649   ierr = PetscFree(submatj->row2proc);CHKERRQ(ierr);
650 
651   ierr = PetscFree(submatj);CHKERRQ(ierr);
652   PetscFunctionReturn(0);
653 }
654 
655 PetscErrorCode MatGetSubMatrices_MPIBAIJ_local_new(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,PetscBool *allrows,PetscBool *allcolumns,Mat *submats)
656 {
657   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
658   Mat            A  = c->A;
659   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*subc;
660   const PetscInt **icol,**irow;
661   PetscInt       *nrow,*ncol,start;
662   PetscErrorCode ierr;
663   PetscMPIInt    rank,size,tag0,tag2,tag3,tag4,*w1,*w2,*w3,*w4,nrqr;
664   PetscInt       **sbuf1,**sbuf2,i,j,k,l,ct1,ct2,**rbuf1,row,proc=-1;
665   PetscInt       nrqs=0,msz,**ptr=NULL,*req_size=NULL,*ctr=NULL,*pa,*tmp=NULL,tcol;
666   PetscInt       **rbuf3=NULL,*req_source1=NULL,*req_source2,**sbuf_aj,**rbuf2=NULL,max1,max2;
667   PetscInt       **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax;
668 #if defined(PETSC_USE_CTABLE)
669   PetscTable     *cmap,cmap_i=NULL,*rmap,rmap_i;
670 #else
671   PetscInt       **cmap,*cmap_i=NULL,**rmap,*rmap_i;
672 #endif
673   const PetscInt *irow_i;
674   PetscInt       ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
675   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3;
676   MPI_Request    *r_waits4,*s_waits3,*s_waits4;
677   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status3,*s_status2;
678   MPI_Status     *r_status3,*r_status4,*s_status4;
679   MPI_Comm       comm;
680   PetscScalar    **rbuf4,*rbuf4_i,**sbuf_aa,*vals,*mat_a,*imat_a,*sbuf_aa_i;
681   PetscMPIInt    *onodes1,*olengths1,end;
682   PetscInt       **row2proc,*row2proc_i,ilen_row,*imat_ilen,*imat_j,*imat_i;
683   Mat_SubMat     **smats,*smat_i;
684   PetscBool      *issorted,colflag,iscsorted=PETSC_TRUE;
685   PetscInt       *sbuf1_i,*rbuf2_i,*rbuf3_i,ilen;
686 
687   PetscInt       bs=C->rmap->bs,bs2=c->bs2,rstart = c->rstartbs;
688   PetscBool      ijonly=c->ijonly; /* private flag indicates only matrix data structures are requested */
689   PetscInt       nzA,nzB,*a_i=a->i,*b_i=b->i,*a_j = a->j,*b_j = b->j,ctmp,imark,*cworkA,*cworkB;
690   PetscScalar    *vworkA,*vworkB,*a_a = a->a,*b_a = b->a;
691   PetscInt       cstart = c->cstartbs,*bmap = c->garray;
692 
693   PetscFunctionBegin;
694   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
695   size = c->size;
696   rank = c->rank;
697 
698   ierr = PetscMalloc5(ismax,&smats,ismax,&row2proc,ismax,&cmap,ismax,&rmap,ismax,&allcolumns);CHKERRQ(ierr);
699   ierr = PetscMalloc5(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol,ismax,&issorted);CHKERRQ(ierr);
700 
701   for (i=0; i<ismax; i++) {
702     ierr = ISSorted(iscol[i],&issorted[i]);CHKERRQ(ierr);
703     if (!issorted[i]) iscsorted = issorted[i];
704 
705     ierr = ISSorted(isrow[i],&issorted[i]);CHKERRQ(ierr);
706 
707     ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
708     ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
709 
710     /* Check for special case: allcolumn */
711     ierr = ISIdentity(iscol[i],&colflag);CHKERRQ(ierr);
712     ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
713 
714     if (colflag && ncol[i] == c->Nbs) {
715       allcolumns[i] = PETSC_TRUE;
716       icol[i] = NULL;
717       printf("[%d] allcolumns[%d] true\n",rank,i);
718     } else {
719       allcolumns[i] = PETSC_FALSE;
720       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
721     }
722   }
723   //printf("[%d] nrow %d, ncol %d\n",rank,nrow[0],ncol[0]);
724 
725   if (scall == MAT_REUSE_MATRIX) {
726     /* Assumes new rows are same length as the old rows */
727     for (i=0; i<ismax; i++) {
728       subc = (Mat_SeqBAIJ*)(submats[i]->data);
729       if (subc->mbs != nrow[i] || subc->nbs != ncol[i]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
730 
731       /* Initial matrix as if empty */
732       ierr = PetscMemzero(subc->ilen,subc->mbs*sizeof(PetscInt));CHKERRQ(ierr);
733 
734       /* Initial matrix as if empty */
735       submats[i]->factortype = C->factortype;
736 
737       smat_i   = subc->submatis1;
738       smats[i] = smat_i;
739 
740       nrqs        = smat_i->nrqs;
741       nrqr        = smat_i->nrqr;
742       rbuf1       = smat_i->rbuf1;
743       rbuf2       = smat_i->rbuf2;
744       rbuf3       = smat_i->rbuf3;
745       req_source2 = smat_i->req_source2;
746 
747       sbuf1     = smat_i->sbuf1;
748       sbuf2     = smat_i->sbuf2;
749       ptr       = smat_i->ptr;
750       tmp       = smat_i->tmp;
751       ctr       = smat_i->ctr;
752 
753       pa          = smat_i->pa;
754       req_size    = smat_i->req_size;
755       req_source1 = smat_i->req_source1;
756 
757       allcolumns[i] = smat_i->allcolumns;
758       row2proc[i]   = smat_i->row2proc;
759       rmap[i]       = smat_i->rmap;
760       cmap[i]       = smat_i->cmap;
761     }
762   } else { /* scall == MAT_INITIAL_MATRIX */
763     /* Get some new tags to keep the communication clean */
764     ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
765     ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
766 
767     /* evaluate communication - mesg to who, length of mesg, and buffer space
768      required. Based on this, buffers are allocated, and data copied into them*/
769     ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);   /* mesg size, initialize work vectors */
770 
771     for (i=0; i<ismax; i++) {
772       jmax   = nrow[i];
773       irow_i = irow[i];
774 
775       ierr   = PetscMalloc1(jmax,&row2proc_i);CHKERRQ(ierr);
776       row2proc[i] = row2proc_i;
777 
778       if (issorted[i]) proc = 0;
779       for (j=0; j<jmax; j++) {
780         if (!issorted[i]) proc = 0;
781         row = irow_i[j];
782         while (row >= c->rangebs[proc+1]) proc++;
783         w4[proc]++;
784         row2proc_i[j] = proc; /* map row index to proc */
785       }
786       for (j=0; j<size; j++) {
787         if (w4[j]) { w1[j] += w4[j];  w3[j]++; w4[j] = 0;}
788       }
789     }
790 
791     nrqs     = 0;              /* no of outgoing messages */
792     msz      = 0;              /* total mesg length (for all procs) */
793     w1[rank] = 0;              /* no mesg sent to self */
794     w3[rank] = 0;
795     for (i=0; i<size; i++) {
796       if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
797     }
798     ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
799     for (i=0,j=0; i<size; i++) {
800       if (w1[i]) { pa[j] = i; j++; }
801     }
802 
803     /* Each message would have a header = 1 + 2*(no of IS) + data */
804     for (i=0; i<nrqs; i++) {
805       j      = pa[i];
806       w1[j] += w2[j] + 2* w3[j];
807       msz   += w1[j];
808     }
809     ierr = PetscInfo2(0,"Number of outgoing messages %D Total message length %D\n",nrqs,msz);CHKERRQ(ierr);
810 
811     /* Determine the number of messages to expect, their lengths, from from-ids */
812     ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
813     ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
814 
815     /* Now post the Irecvs corresponding to these messages */
816     tag0 = ((PetscObject)C)->tag;
817     ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
818     /* printf("[%d] nrqs %d, nrqr %d\n",rank,nrqs,nrqr); */
819 
820     ierr = PetscFree(onodes1);CHKERRQ(ierr);
821     ierr = PetscFree(olengths1);CHKERRQ(ierr);
822 
823     /* Allocate Memory for outgoing messages */
824     ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
825     ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
826     ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
827 
828     {
829       PetscInt *iptr = tmp;
830       k    = 0;
831       for (i=0; i<nrqs; i++) {
832         j        = pa[i];
833         iptr    += k;
834         sbuf1[j] = iptr;
835         k        = w1[j];
836       }
837     }
838 
839     /* Form the outgoing messages. Initialize the header space */
840     for (i=0; i<nrqs; i++) {
841       j           = pa[i];
842       sbuf1[j][0] = 0;
843       ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
844       ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
845     }
846 
847     /* Parse the isrow and copy data into outbuf */
848     for (i=0; i<ismax; i++) {
849       row2proc_i = row2proc[i];
850       ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
851       irow_i = irow[i];
852       jmax   = nrow[i];
853       for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
854         proc = row2proc_i[j];
855         if (proc != rank) { /* copy to the outgoing buf*/
856           ctr[proc]++;
857           *ptr[proc] = irow_i[j];
858           ptr[proc]++;
859         }
860       }
861       /* Update the headers for the current IS */
862       for (j=0; j<size; j++) { /* Can Optimise this loop too */
863         if ((ctr_j = ctr[j])) {
864           sbuf1_j        = sbuf1[j];
865           k              = ++sbuf1_j[0];
866           sbuf1_j[2*k]   = ctr_j;
867           sbuf1_j[2*k-1] = i;
868         }
869       }
870     }
871 
872     /*  Now  post the sends */
873     ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
874     for (i=0; i<nrqs; ++i) {
875       j    = pa[i];
876       ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
877     }
878 
879     /* Post Receives to capture the buffer size */
880     ierr = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
881     ierr = PetscMalloc3(nrqs+1,&req_source2,nrqs+1,&rbuf2,nrqs+1,&rbuf3);CHKERRQ(ierr);
882     rbuf2[0] = tmp + msz;
883     for (i=1; i<nrqs; ++i) {
884       rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
885     }
886     for (i=0; i<nrqs; ++i) {
887       j    = pa[i];
888       ierr = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag2,comm,r_waits2+i);CHKERRQ(ierr);
889     }
890 
891     /* Send to other procs the buf size they should allocate */
892     /* Receive messages*/
893     ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
894     ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
895     ierr = PetscMalloc3(nrqr,&sbuf2,nrqr,&req_size,nrqr,&req_source1);CHKERRQ(ierr);
896     {
897       PetscInt   *sAi = a->i,*sBi = b->i,id;
898       PetscInt   *sbuf2_i;
899 
900       ierr = MPI_Waitall(nrqr,r_waits1,r_status1);CHKERRQ(ierr);
901       for (i=0; i<nrqr; ++i) {
902         req_size[i] = 0;
903         rbuf1_i        = rbuf1[i];
904         start          = 2*rbuf1_i[0] + 1;
905         ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
906         ierr           = PetscMalloc1(end+1,&sbuf2[i]);CHKERRQ(ierr);
907         sbuf2_i        = sbuf2[i];
908         for (j=start; j<end; j++) {
909           id              = rbuf1_i[j] - rstart;
910           ncols           = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
911           sbuf2_i[j]      = ncols;
912           req_size[i] += ncols;
913         }
914         req_source1[i] = r_status1[i].MPI_SOURCE;
915         /* form the header */
916         sbuf2_i[0] = req_size[i];
917         for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
918 
919         ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source1[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
920       }
921     }
922     ierr = PetscFree(r_status1);CHKERRQ(ierr);
923     ierr = PetscFree(r_waits1);CHKERRQ(ierr);
924     ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
925 
926     /* Receive messages*/
927     ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
928     ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
929 
930     ierr = MPI_Waitall(nrqs,r_waits2,r_status2);CHKERRQ(ierr);
931     for (i=0; i<nrqs; ++i) {
932       ierr = PetscMalloc1(rbuf2[i][0]+1,&rbuf3[i]);CHKERRQ(ierr);
933       req_source2[i] = r_status2[i].MPI_SOURCE;
934       ierr = MPI_Irecv(rbuf3[i],rbuf2[i][0],MPIU_INT,req_source2[i],tag3,comm,r_waits3+i);CHKERRQ(ierr);
935     }
936     ierr = PetscFree(r_status2);CHKERRQ(ierr);
937     ierr = PetscFree(r_waits2);CHKERRQ(ierr);
938 
939     /* Wait on sends1 and sends2 */
940     ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
941     ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
942 
943     if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
944     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
945     ierr = PetscFree(s_status1);CHKERRQ(ierr);
946     ierr = PetscFree(s_status2);CHKERRQ(ierr);
947     ierr = PetscFree(s_waits1);CHKERRQ(ierr);
948     ierr = PetscFree(s_waits2);CHKERRQ(ierr);
949 
950     /* Now allocate sending buffers for a->j, and send them off */
951     ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
952     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
953     ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
954     for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
955 
956     ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
957     {
958 
959       for (i=0; i<nrqr; i++) {
960         rbuf1_i   = rbuf1[i];
961         sbuf_aj_i = sbuf_aj[i];
962         ct1       = 2*rbuf1_i[0] + 1;
963         ct2       = 0;
964         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
965           kmax = rbuf1[i][2*j];
966           for (k=0; k<kmax; k++,ct1++) {
967             row    = rbuf1_i[ct1] - rstart;
968             nzA    = a_i[row+1] - a_i[row]; nzB = b_i[row+1] - b_i[row];
969             ncols  = nzA + nzB;
970             cworkA = a_j + a_i[row]; cworkB = b_j + b_i[row];
971 
972             /* load the column indices for this row into cols */
973             cols = sbuf_aj_i + ct2;
974             for (l=0; l<nzB; l++) {
975               if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
976               else break;
977             }
978             imark = l;
979             for (l=0; l<nzA; l++) {cols[imark+l] = cstart + cworkA[l];}
980             for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
981             ct2 += ncols;
982           }
983         }
984         ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source1[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
985       }
986     }
987     ierr = PetscMalloc2(nrqs+1,&r_status3,nrqr+1,&s_status3);CHKERRQ(ierr);
988 
989     /* create col map: global col of C -> local col of submatrices */
990     const PetscInt *icol_i;
991 #if defined(PETSC_USE_CTABLE)
992     for (i=0; i<ismax; i++) {
993       if (!allcolumns[i]) {
994         ierr = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
995 
996         jmax   = ncol[i];
997         icol_i = icol[i];
998         cmap_i = cmap[i];
999         for (j=0; j<jmax; j++) {
1000           ierr = PetscTableAdd(cmap[i],icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1001         }
1002       } else cmap[i] = NULL;
1003     }
1004 #else
1005     for (i=0; i<ismax; i++) {
1006       if (!allcolumns[i]) {
1007         ierr   = PetscCalloc1(c->Nbs,&cmap[i]);CHKERRQ(ierr);
1008         jmax   = ncol[i];
1009         icol_i = icol[i];
1010         cmap_i = cmap[i];
1011         for (j=0; j<jmax; j++) cmap_i[icol_i[j]] = j+1;
1012       } else cmap[i] = NULL;
1013     }
1014 #endif
1015 
1016     /* Create lens which is required for MatCreate... */
1017     for (i=0,j=0; i<ismax; i++) j += nrow[i];
1018     ierr = PetscMalloc1(ismax,&lens);CHKERRQ(ierr);
1019 
1020     if (ismax) {
1021       ierr = PetscCalloc1(j,&lens[0]);CHKERRQ(ierr);
1022     }
1023     for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1024 
1025     /* Update lens from local data */
1026     for (i=0; i<ismax; i++) {
1027       row2proc_i = row2proc[i];
1028       jmax = nrow[i];
1029       if (!allcolumns[i]) cmap_i = cmap[i];
1030       irow_i = irow[i];
1031       lens_i = lens[i];
1032       for (j=0; j<jmax; j++) {
1033         row = irow_i[j]; /* global blocked row of C */
1034         proc = row2proc_i[j];
1035         if (proc == rank) {
1036           /* Get indices from matA and then from matB */
1037 #if defined(PETSC_USE_CTABLE)
1038           PetscInt   tt;
1039 #endif
1040           row    = row - rstart;
1041           nzA    = a_i[row+1] - a_i[row];
1042           nzB    = b_i[row+1] - b_i[row];
1043           cworkA =  a_j + a_i[row];
1044           cworkB = b_j + b_i[row];
1045 
1046           if (!allcolumns[i]) {
1047 #if defined(PETSC_USE_CTABLE)
1048             for (k=0; k<nzA; k++) {
1049               ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1050               if (tt) lens_i[j]++;
1051             }
1052             for (k=0; k<nzB; k++) {
1053               ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1054               if (tt) lens_i[j]++;
1055             }
1056 
1057 #else
1058             for (k=0; k<nzA; k++) {
1059               if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1060             }
1061             for (k=0; k<nzB; k++) {
1062               if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1063             }
1064 #endif
1065           } else { /* allcolumns */
1066             lens_i[j] = nzA + nzB;
1067           }
1068         }
1069       }
1070     }
1071 
1072     /* Create row map: global row of C -> local row of submatrices */
1073 #if defined(PETSC_USE_CTABLE)
1074     for (i=0; i<ismax; i++) {
1075       ierr   = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1076       irow_i = irow[i];
1077       jmax   = nrow[i];
1078       for (j=0; j<jmax; j++) {
1079       ierr = PetscTableAdd(rmap[i],irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1080       }
1081     }
1082 #else
1083     for (i=0; i<ismax; i++) {
1084       ierr   = PetscCalloc1(c->Mbs,&rmap[i]);CHKERRQ(ierr);
1085       rmap_i = rmap[i];
1086       irow_i = irow[i];
1087       jmax   = nrow[i];
1088       for (j=0; j<jmax; j++) {
1089         rmap_i[irow_i[j]] = j;
1090       }
1091     }
1092 #endif
1093 
1094     /* Update lens from offproc data */
1095     {
1096       PetscInt *rbuf2_i,*rbuf3_i,*sbuf1_i;
1097 
1098       ierr    = MPI_Waitall(nrqs,r_waits3,r_status3);CHKERRQ(ierr);
1099       for (tmp2=0; tmp2<nrqs; tmp2++) {
1100         sbuf1_i = sbuf1[pa[tmp2]];
1101         jmax    = sbuf1_i[0];
1102         ct1     = 2*jmax+1;
1103         ct2     = 0;
1104         rbuf2_i = rbuf2[tmp2];
1105         rbuf3_i = rbuf3[tmp2];
1106         for (j=1; j<=jmax; j++) {
1107           is_no  = sbuf1_i[2*j-1];
1108           max1   = sbuf1_i[2*j];
1109           lens_i = lens[is_no];
1110           if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1111           rmap_i = rmap[is_no];
1112           for (k=0; k<max1; k++,ct1++) {
1113 #if defined(PETSC_USE_CTABLE)
1114             ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
1115             row--;
1116             if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1117 #else
1118             row = rmap_i[sbuf1_i[ct1]]; /* the val in the new matrix to be */
1119 #endif
1120             max2 = rbuf2_i[ct1];
1121             for (l=0; l<max2; l++,ct2++) {
1122               if (!allcolumns[is_no]) {
1123 #if defined(PETSC_USE_CTABLE)
1124                 ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1125 #else
1126                 tcol = cmap_i[rbuf3_i[ct2]];
1127 #endif
1128                 if (tcol) lens_i[row]++;
1129               } else { /* allcolumns */
1130                 lens_i[row]++; /* lens_i[row] += max2 ? */
1131               }
1132             }
1133           }
1134         }
1135       }
1136     }
1137     ierr = PetscFree(r_waits3);CHKERRQ(ierr);
1138     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
1139     ierr = PetscFree2(r_status3,s_status3);CHKERRQ(ierr);
1140     ierr = PetscFree(s_waits3);CHKERRQ(ierr);
1141 
1142     /* Create the submatrices */
1143     for (i=0; i<ismax; i++) {
1144       PetscInt bs_tmp;
1145       if (ijonly) bs_tmp = 1;
1146       else        bs_tmp = bs;
1147 
1148       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
1149       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
1150 
1151       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
1152       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
1153       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
1154 
1155       /* create struct Mat_SubMat and attached it to submat */
1156       ierr = PetscNew(&smat_i);CHKERRQ(ierr);
1157       subc = (Mat_SeqBAIJ*)submats[i]->data;
1158       subc->submatis1 = smat_i;
1159       smats[i]        = smat_i;
1160 
1161       smat_i->destroy          = submats[i]->ops->destroy;
1162       submats[i]->ops->destroy = MatDestroy_MPIBAIJ_MatGetSubmatrices;
1163       submats[i]->factortype   = C->factortype;
1164 
1165       smat_i->id          = i;
1166       smat_i->nrqs        = nrqs;
1167       smat_i->nrqr        = nrqr;
1168       smat_i->rbuf1       = rbuf1;
1169       smat_i->rbuf2       = rbuf2;
1170       smat_i->rbuf3       = rbuf3;
1171       smat_i->sbuf2       = sbuf2;
1172       smat_i->req_source2 = req_source2;
1173 
1174       smat_i->sbuf1       = sbuf1;
1175       smat_i->ptr         = ptr;
1176       smat_i->tmp         = tmp;
1177       smat_i->ctr         = ctr;
1178 
1179       smat_i->pa           = pa;
1180       smat_i->req_size     = req_size;
1181       smat_i->req_source1  = req_source1;
1182 
1183       smat_i->allcolumns  = allcolumns[i];
1184       smat_i->singleis    = PETSC_FALSE;
1185       smat_i->row2proc    = row2proc[i];
1186       smat_i->rmap        = rmap[i];
1187       smat_i->cmap        = cmap[i];
1188     }
1189 
1190     if (ismax) {ierr = PetscFree(lens[0]);CHKERRQ(ierr);}
1191     ierr = PetscFree(lens);CHKERRQ(ierr);
1192     ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
1193     ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
1194 
1195   } /* endof scall == MAT_INITIAL_MATRIX */
1196 
1197   /* Post recv matrix values */
1198   ierr = PetscObjectGetNewTag((PetscObject)C,&tag4);CHKERRQ(ierr);
1199   ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
1200   ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
1201   ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
1202   ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
1203   for (i=0; i<nrqs; ++i) {
1204     ierr = PetscMalloc1(rbuf2[i][0]*bs2,&rbuf4[i]);CHKERRQ(ierr);
1205     ierr = MPI_Irecv(rbuf4[i],rbuf2[i][0]*bs2,MPIU_SCALAR,req_source2[i],tag4,comm,r_waits4+i);CHKERRQ(ierr);
1206   }
1207 
1208   /* Allocate sending buffers for a->a, and send them off */
1209   ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
1210   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1211 
1212   ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
1213   for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1214 
1215   ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
1216 
1217   for (i=0; i<nrqr; i++) {
1218     rbuf1_i   = rbuf1[i];
1219     sbuf_aa_i = sbuf_aa[i];
1220     ct1       = 2*rbuf1_i[0]+1;
1221     ct2       = 0;
1222     for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1223       kmax = rbuf1_i[2*j];
1224       for (k=0; k<kmax; k++,ct1++) {
1225         row    = rbuf1_i[ct1] - rstart;
1226         nzA    = a_i[row+1] - a_i[row];
1227         nzB    = b_i[row+1] - b_i[row];
1228         ncols  = nzA + nzB;
1229         cworkB = b_j + b_i[row];
1230         vworkA = a_a + a_i[row]*bs2;
1231         vworkB = b_a + b_i[row]*bs2;
1232 
1233         /* load the column values for this row into vals*/
1234         vals = sbuf_aa_i+ct2*bs2;
1235         for (l=0; l<nzB; l++) {
1236           if ((bmap[cworkB[l]]) < cstart) {
1237             ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1238           } else break;
1239         }
1240         imark = l;
1241         for (l=0; l<nzA; l++) {
1242           ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);//error in proc[1]???
1243         }
1244         for (l=imark; l<nzB; l++) {
1245           ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1246         }
1247 
1248         ct2 += ncols;
1249       }
1250     }
1251     ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_SCALAR,req_source1[i],tag4,comm,s_waits4+i);CHKERRQ(ierr);
1252   }
1253 
1254   if (!ismax) {
1255     ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
1256     ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1257   }
1258 
1259   /* Assemble the matrices */
1260   /* First assemble the local rows */
1261   for (i=0; i<ismax; i++) {
1262     row2proc_i = row2proc[i];
1263     subc      = (Mat_SeqBAIJ*)submats[i]->data;
1264     imat_ilen = subc->ilen;
1265     imat_j    = subc->j;
1266     imat_i    = subc->i;
1267     imat_a    = subc->a;
1268 
1269     if (!allcolumns[i]) cmap_i = cmap[i];
1270     rmap_i = rmap[i];
1271     irow_i = irow[i];
1272     jmax   = nrow[i];
1273     for (j=0; j<jmax; j++) {
1274       row  = irow_i[j];
1275       proc = row2proc_i[j];
1276 
1277       if (proc == rank) {
1278 
1279         row    = row - rstart;
1280         nzA    = a_i[row+1] - a_i[row];
1281         nzB    = b_i[row+1] - b_i[row];
1282         cworkA = a_j + a_i[row];
1283         cworkB = b_j + b_i[row];
1284         if (!ijonly) {
1285           vworkA = a_a + a_i[row]*bs2;
1286           vworkB = b_a + b_i[row]*bs2;
1287         }
1288 #if defined(PETSC_USE_CTABLE)
1289         ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
1290         row--;
1291         if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1292 #else
1293         row = rmap_i[row + rstart];
1294 #endif
1295         mat_i = imat_i[row];
1296         if (!ijonly) mat_a = imat_a + mat_i*bs2;
1297         mat_j    = imat_j + mat_i;
1298         ilen_row = imat_ilen[row];
1299 
1300         /* load the column indices for this row into cols*/
1301         if (!allcolumns[i]) {
1302           for (l=0; l<nzB; l++) {
1303             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1304 #if defined(PETSC_USE_CTABLE)
1305               ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
1306               if (tcol) {
1307 #else
1308               if ((tcol = cmap_i[ctmp])) {
1309 #endif
1310                 *mat_j++ = tcol - 1;
1311                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1312                 mat_a   += bs2;
1313                 ilen_row++;
1314               }
1315             } else break;
1316           }
1317           imark = l;
1318           for (l=0; l<nzA; l++) {
1319 #if defined(PETSC_USE_CTABLE)
1320             ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
1321             if (tcol) {
1322 #else
1323             if ((tcol = cmap_i[cstart + cworkA[l]])) {
1324 #endif
1325               *mat_j++ = tcol - 1;
1326               if (!ijonly) {
1327                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1328                 mat_a += bs2;
1329               }
1330               ilen_row++;
1331             }
1332           }
1333           for (l=imark; l<nzB; l++) {
1334 #if defined(PETSC_USE_CTABLE)
1335             ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
1336             if (tcol) {
1337 #else
1338             if ((tcol = cmap_i[bmap[cworkB[l]]])) {
1339 #endif
1340               *mat_j++ = tcol - 1;
1341               if (!ijonly) {
1342                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1343                 mat_a += bs2;
1344               }
1345               ilen_row++;
1346             }
1347           }
1348         } else { /* allcolumns */
1349           for (l=0; l<nzB; l++) {
1350             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1351               *mat_j++ = ctmp;
1352               ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1353               mat_a   += bs2;
1354               ilen_row++;
1355             } else break;
1356           }
1357           imark = l;
1358           for (l=0; l<nzA; l++) {
1359             *mat_j++ = cstart+cworkA[l];
1360             if (!ijonly) {
1361               ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1362               mat_a += bs2;
1363             }
1364             ilen_row++;
1365           }
1366           for (l=imark; l<nzB; l++) {
1367             *mat_j++ = bmap[cworkB[l]];
1368             if (!ijonly) {
1369               ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1370               mat_a += bs2;
1371             }
1372             ilen_row++;
1373           }
1374         }
1375         imat_ilen[row] = ilen_row;
1376       }
1377     }
1378   }
1379 
1380   /* Now assemble the off proc rows */
1381   if (!ijonly) {
1382     ierr = MPI_Waitall(nrqs,r_waits4,r_status4);CHKERRQ(ierr);
1383   }
1384   for (tmp2=0; tmp2<nrqs; tmp2++) {
1385     sbuf1_i = sbuf1[pa[tmp2]];
1386     jmax    = sbuf1_i[0];
1387     ct1     = 2*jmax + 1;
1388     ct2     = 0;
1389     rbuf2_i = rbuf2[tmp2];
1390     rbuf3_i = rbuf3[tmp2];
1391     if (!ijonly) rbuf4_i = rbuf4[tmp2];
1392     for (j=1; j<=jmax; j++) {
1393       is_no     = sbuf1_i[2*j-1];
1394       rmap_i    = rmap[is_no];
1395       if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1396       subc      = (Mat_SeqBAIJ*)submats[is_no]->data;
1397       imat_ilen = subc->ilen;
1398       imat_j    = subc->j;
1399       imat_i    = subc->i;
1400       if (!ijonly) imat_a    = subc->a;
1401       max1      = sbuf1_i[2*j];
1402       for (k=0; k<max1; k++,ct1++) { /* for each recved block row */
1403         row = sbuf1_i[ct1];
1404 #if defined(PETSC_USE_CTABLE)
1405         ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
1406         row--;
1407         if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1408 #else
1409         row = rmap_i[row];
1410 #endif
1411         ilen  = imat_ilen[row];
1412         mat_i = imat_i[row];
1413         if (!ijonly) mat_a = imat_a + mat_i*bs2;
1414         mat_j = imat_j + mat_i;
1415         max2  = rbuf2_i[ct1];
1416         if (!allcolumns[is_no]) {
1417           for (l=0; l<max2; l++,ct2++) {
1418 #if defined(PETSC_USE_CTABLE)
1419             ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1420 #else
1421             tcol = cmap_i[rbuf3_i[ct2]];
1422 #endif
1423             if (tcol) {
1424               *mat_j++ = tcol - 1;
1425               if (!ijonly) {
1426                 ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1427                 mat_a += bs2;
1428               }
1429               //*mat_a++ = rbuf4_i[ct2];
1430               ilen++;
1431             }
1432           }
1433         } else { /* allcolumns */
1434           for (l=0; l<max2; l++,ct2++) {
1435             *mat_j++ = rbuf3_i[ct2]; /* same global column index of C */
1436             //*mat_a++ = rbuf4_i[ct2];
1437             if (!ijonly) {
1438               ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1439               mat_a += bs2;
1440             }
1441             ilen++;
1442           }
1443         }
1444         imat_ilen[row] = ilen;
1445       }
1446     }
1447   }
1448 
1449   if (!iscsorted) { /* sort column indices of the rows -- not done yet!!! */
1450     for (i=0; i<ismax; i++) {
1451       subc       = (Mat_SeqBAIJ*)submats[i]->data;
1452       imat_j    = subc->j;
1453       imat_i    = subc->i;
1454       imat_a    = subc->a;
1455       imat_ilen = subc->ilen;
1456 
1457       if (allcolumns[i]) continue;
1458       jmax = nrow[i];
1459       for (j=0; j<jmax; j++) {
1460         PetscInt ilen;
1461 
1462         mat_i = imat_i[j];
1463         if (!ijonly) mat_a = imat_a + mat_i;
1464         mat_j = imat_j + mat_i;
1465         ilen  = imat_ilen[j];
1466         ierr  = PetscSortIntWithScalarArray(ilen,mat_j,mat_a);CHKERRQ(ierr);
1467       }
1468     }
1469   }
1470 
1471   ierr = PetscFree(r_status4);CHKERRQ(ierr);
1472   ierr = PetscFree(r_waits4);CHKERRQ(ierr);
1473   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
1474   ierr = PetscFree(s_waits4);CHKERRQ(ierr);
1475   ierr = PetscFree(s_status4);CHKERRQ(ierr);
1476 
1477   /* Restore the indices */
1478   for (i=0; i<ismax; i++) {
1479     ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
1480     if (!allcolumns[i]) {
1481       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
1482     }
1483   }
1484 
1485   for (i=0; i<ismax; i++) {
1486     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1487     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1488   }
1489 
1490   /* Destroy allocated memory */
1491   if (!ismax) {
1492     ierr = PetscFree(pa);CHKERRQ(ierr);
1493 
1494     ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
1495     for (i=0; i<nrqr; ++i) {
1496       ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
1497     }
1498     for (i=0; i<nrqs; ++i) {
1499       ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
1500     }
1501 
1502     ierr = PetscFree3(sbuf2,req_size,req_source1);CHKERRQ(ierr);
1503     ierr = PetscFree3(req_source2,rbuf2,rbuf3);CHKERRQ(ierr);
1504   }
1505 
1506   ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
1507   ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
1508   ierr = PetscFree5(irow,icol,nrow,ncol,issorted);CHKERRQ(ierr);
1509 
1510   for (i=0; i<nrqs; ++i) {
1511     ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);
1512   }
1513   ierr = PetscFree(rbuf4);CHKERRQ(ierr);
1514 
1515   ierr = PetscFree5(smats,row2proc,cmap,rmap,allcolumns);CHKERRQ(ierr);
1516   PetscFunctionReturn(0);
1517 }
1518 
1519 //------------ endof new -------------
1520 
1521 PetscErrorCode MatGetSubMatrices_MPIBAIJ_local(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,PetscBool *allrows,PetscBool *allcolumns,Mat *submats)
1522 {
1523   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
1524   Mat            A  = c->A;
1525   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*mat;
1526   const PetscInt **irow,**icol,*irow_i;
1527   PetscInt       *nrow,*ncol,*w3,*w4,start;
1528   PetscErrorCode ierr;
1529   PetscMPIInt    size,tag0,tag1,tag2,tag3,*w1,*w2,nrqr,idex,end,proc;
1530   PetscInt       **sbuf1,**sbuf2,rank,i,j,k,l,ct1,ct2,**rbuf1,row;
1531   PetscInt       nrqs,msz,**ptr,*req_size,*ctr,*pa,*tmp,tcol;
1532   PetscInt       **rbuf3,*req_source,**sbuf_aj,**rbuf2,max1,max2;
1533   PetscInt       **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax;
1534   PetscInt       ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
1535   PetscInt       bs     =C->rmap->bs,bs2=c->bs2,*a_j=a->j,*b_j=b->j,*cworkA,*cworkB;
1536   PetscInt       cstart = c->cstartbs,nzA,nzB,*a_i=a->i,*b_i=b->i,imark;
1537   PetscInt       *bmap  = c->garray,ctmp,rstart=c->rstartbs;
1538   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3,*s_waits3;
1539   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status3,*s_status2,*r_status3;
1540   MPI_Comm       comm;
1541   PetscBool      flag;
1542   PetscMPIInt    *onodes1,*olengths1;
1543   PetscBool      ijonly=c->ijonly; /* private flag indicates only matrix data structures are requested */
1544 
1545   /* variables below are used for the matrix numerical values - case of !ijonly */
1546   MPI_Request *r_waits4,*s_waits4;
1547   MPI_Status  *r_status4,*s_status4;
1548   MatScalar   **rbuf4,**sbuf_aa,*vals,*mat_a = NULL,*sbuf_aa_i,*vworkA = NULL,*vworkB = NULL;
1549   MatScalar   *a_a=a->a,*b_a=b->a;
1550 
1551 #if defined(PETSC_USE_CTABLE)
1552   PetscInt   tt;
1553   PetscTable *rmap,*cmap,rmap_i,cmap_i=NULL;
1554 #else
1555   PetscInt **cmap,*cmap_i=NULL,*rtable,*rmap_i,**rmap, Mbs = c->Mbs;
1556 #endif
1557 
1558   PetscFunctionBegin;
1559   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
1560   tag0 = ((PetscObject)C)->tag;
1561   size = c->size;
1562   rank = c->rank;
1563   //if (!rank) printf("MatGetSubMatrices_MPIBAIJ scall %d, bs %d\n",scall,bs);
1564 
1565   /* Get some new tags to keep the communication clean */
1566   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
1567   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
1568   ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
1569 
1570 #if defined(PETSC_USE_CTABLE)
1571   ierr = PetscMalloc4(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol);CHKERRQ(ierr);
1572 #else
1573   ierr = PetscMalloc5(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol,Mbs+1,&rtable);CHKERRQ(ierr);
1574   /* Create hash table for the mapping :row -> proc*/
1575   for (i=0,j=0; i<size; i++) {
1576     jmax = C->rmap->range[i+1]/bs;
1577     for (; j<jmax; j++) rtable[j] = i;
1578   }
1579 #endif
1580 
1581   for (i=0; i<ismax; i++) {
1582     if (allrows[i]) {
1583       irow[i] = NULL;
1584       nrow[i] = C->rmap->N/bs;
1585     } else {
1586       ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
1587       ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
1588     }
1589 
1590     if (allcolumns[i]) {
1591       icol[i] = NULL;
1592       ncol[i] = C->cmap->N/bs;
1593     } else {
1594       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
1595       ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
1596     }
1597   }
1598 
1599   /* evaluate communication - mesg to who,length of mesg,and buffer space
1600      required. Based on this, buffers are allocated, and data copied into them*/
1601   ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);
1602   for (i=0; i<ismax; i++) {
1603     ierr   = PetscMemzero(w4,size*sizeof(PetscInt));CHKERRQ(ierr); /* initialise work vector*/
1604     jmax   = nrow[i];
1605     irow_i = irow[i];
1606     for (j=0; j<jmax; j++) {
1607       if (allrows[i]) row = j;
1608       else row = irow_i[j];
1609 
1610 #if defined(PETSC_USE_CTABLE)
1611       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1612 #else
1613       proc = rtable[row];
1614 #endif
1615       w4[proc]++;
1616     }
1617     for (j=0; j<size; j++) {
1618       if (w4[j]) { w1[j] += w4[j];  w3[j]++;}
1619     }
1620   }
1621 
1622   nrqs     = 0;              /* no of outgoing messages */
1623   msz      = 0;              /* total mesg length for all proc */
1624   w1[rank] = 0;              /* no mesg sent to intself */
1625   w3[rank] = 0;
1626   for (i=0; i<size; i++) {
1627     if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
1628   }
1629   ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
1630   for (i=0,j=0; i<size; i++) {
1631     if (w1[i]) { pa[j] = i; j++; }
1632   }
1633 
1634   /* Each message would have a header = 1 + 2*(no of IS) + data */
1635   for (i=0; i<nrqs; i++) {
1636     j     = pa[i];
1637     w1[j] += w2[j] + 2* w3[j];
1638     msz   += w1[j];
1639   }
1640 
1641   /* Determine the number of messages to expect, their lengths, from from-ids */
1642   ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
1643   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
1644 
1645   /* Now post the Irecvs corresponding to these messages */
1646   ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
1647 
1648   ierr = PetscFree(onodes1);CHKERRQ(ierr);
1649   ierr = PetscFree(olengths1);CHKERRQ(ierr);
1650 
1651   /* Allocate Memory for outgoing messages */
1652   ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
1653   ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
1654   ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
1655   {
1656     PetscInt *iptr = tmp,ict = 0;
1657     for (i=0; i<nrqs; i++) {
1658       j        = pa[i];
1659       iptr    += ict;
1660       sbuf1[j] = iptr;
1661       ict      = w1[j];
1662     }
1663   }
1664 
1665   /* Form the outgoing messages */
1666   /* Initialise the header space */
1667   for (i=0; i<nrqs; i++) {
1668     j           = pa[i];
1669     sbuf1[j][0] = 0;
1670     ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
1671     ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
1672   }
1673 
1674   /* Parse the isrow and copy data into outbuf */
1675   for (i=0; i<ismax; i++) {
1676     ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
1677     irow_i = irow[i];
1678     jmax   = nrow[i];
1679     for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
1680       if (allrows[i]) row = j;
1681       else row = irow_i[j];
1682 
1683 #if defined(PETSC_USE_CTABLE)
1684       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1685 #else
1686       proc = rtable[row];
1687 #endif
1688       if (proc != rank) { /* copy to the outgoing buf*/
1689         ctr[proc]++;
1690         *ptr[proc] = row;
1691         ptr[proc]++;
1692       }
1693     }
1694     /* Update the headers for the current IS */
1695     for (j=0; j<size; j++) { /* Can Optimise this loop too */
1696       if ((ctr_j = ctr[j])) {
1697         sbuf1_j        = sbuf1[j];
1698         k              = ++sbuf1_j[0];
1699         sbuf1_j[2*k]   = ctr_j;
1700         sbuf1_j[2*k-1] = i;
1701       }
1702     }
1703   }
1704 
1705   /*  Now  post the sends */
1706   ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
1707   for (i=0; i<nrqs; ++i) {
1708     j    = pa[i];
1709     ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
1710   }
1711 
1712   /* Post Recieves to capture the buffer size */
1713   ierr     = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
1714   ierr     = PetscMalloc1(nrqs+1,&rbuf2);CHKERRQ(ierr);
1715   rbuf2[0] = tmp + msz;
1716   for (i=1; i<nrqs; ++i) {
1717     rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
1718   }
1719   for (i=0; i<nrqs; ++i) {
1720     j        = pa[i];
1721     ierr     = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag1,comm,r_waits2+i);CHKERRQ(ierr);
1722   }
1723 
1724   /* Send to other procs the buf size they should allocate */
1725 
1726   /* Receive messages*/
1727   ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
1728   ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
1729   ierr = PetscMalloc3(nrqr+1,&sbuf2,nrqr,&req_size,nrqr,&req_source);CHKERRQ(ierr);
1730   {
1731     Mat_SeqBAIJ *sA  = (Mat_SeqBAIJ*)c->A->data,*sB = (Mat_SeqBAIJ*)c->B->data;
1732     PetscInt    *sAi = sA->i,*sBi = sB->i,id,*sbuf2_i;
1733 
1734     for (i=0; i<nrqr; ++i) {
1735       ierr = MPI_Waitany(nrqr,r_waits1,&idex,r_status1+i);CHKERRQ(ierr);
1736 
1737       req_size[idex] = 0;
1738       rbuf1_i        = rbuf1[idex];
1739       start          = 2*rbuf1_i[0] + 1;
1740       ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
1741       ierr           = PetscMalloc1(end,&sbuf2[idex]);CHKERRQ(ierr);
1742       sbuf2_i        = sbuf2[idex];
1743       for (j=start; j<end; j++) {
1744         id              = rbuf1_i[j] - rstart;
1745         ncols           = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
1746         sbuf2_i[j]      = ncols;
1747         req_size[idex] += ncols;
1748       }
1749       req_source[idex] = r_status1[i].MPI_SOURCE;
1750       /* form the header */
1751       sbuf2_i[0] = req_size[idex];
1752       for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
1753       ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source[idex],tag1,comm,s_waits2+i);CHKERRQ(ierr);
1754     }
1755   }
1756   ierr = PetscFree(r_status1);CHKERRQ(ierr);
1757   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
1758 
1759   /*  recv buffer sizes */
1760   /* Receive messages*/
1761   ierr = PetscMalloc1(nrqs+1,&rbuf3);CHKERRQ(ierr);
1762   ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
1763   ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
1764   if (!ijonly) {
1765     ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
1766     ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
1767   }
1768 
1769   for (i=0; i<nrqs; ++i) {
1770     ierr = MPI_Waitany(nrqs,r_waits2,&idex,r_status2+i);CHKERRQ(ierr);
1771     ierr = PetscMalloc1(rbuf2[idex][0],&rbuf3[idex]);CHKERRQ(ierr);
1772     ierr = MPI_Irecv(rbuf3[idex],rbuf2[idex][0],MPIU_INT,r_status2[i].MPI_SOURCE,tag2,comm,r_waits3+idex);CHKERRQ(ierr);
1773     if (!ijonly) {
1774       ierr = PetscMalloc1(rbuf2[idex][0]*bs2,&rbuf4[idex]);CHKERRQ(ierr);
1775       ierr = MPI_Irecv(rbuf4[idex],rbuf2[idex][0]*bs2,MPIU_MATSCALAR,r_status2[i].MPI_SOURCE,tag3,comm,r_waits4+idex);CHKERRQ(ierr);
1776     }
1777   }
1778   ierr = PetscFree(r_status2);CHKERRQ(ierr);
1779   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
1780 
1781   /* Wait on sends1 and sends2 */
1782   ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
1783   ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
1784 
1785   if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
1786   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
1787   ierr = PetscFree(s_status1);CHKERRQ(ierr);
1788   ierr = PetscFree(s_status2);CHKERRQ(ierr);
1789   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
1790   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
1791 
1792   /* Now allocate buffers for a->j, and send them off */
1793   ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
1794   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1795   ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
1796   for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
1797 
1798   ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
1799   {
1800     for (i=0; i<nrqr; i++) {
1801       rbuf1_i   = rbuf1[i];
1802       sbuf_aj_i = sbuf_aj[i];
1803       ct1       = 2*rbuf1_i[0] + 1;
1804       ct2       = 0;
1805       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1806         kmax = rbuf1[i][2*j];
1807         for (k=0; k<kmax; k++,ct1++) {
1808           row    = rbuf1_i[ct1] - rstart;
1809           nzA    = a_i[row+1] - a_i[row];
1810           nzB    = b_i[row+1] - b_i[row];
1811           ncols  = nzA + nzB;
1812           cworkA = a_j + a_i[row];
1813           cworkB = b_j + b_i[row];
1814 
1815           /* load the column indices for this row into cols*/
1816           cols = sbuf_aj_i + ct2;
1817           for (l=0; l<nzB; l++) {
1818             if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
1819             else break;
1820           }
1821           imark = l;
1822           for (l=0; l<nzA; l++)   cols[imark+l] = cstart + cworkA[l];
1823           for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
1824           ct2 += ncols;
1825         }
1826       }
1827       ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source[i],tag2,comm,s_waits3+i);CHKERRQ(ierr);
1828     }
1829   }
1830   ierr = PetscMalloc1(nrqs+1,&r_status3);CHKERRQ(ierr);
1831   ierr = PetscMalloc1(nrqr+1,&s_status3);CHKERRQ(ierr);
1832 
1833   /* Allocate buffers for a->a, and send them off */
1834   if (!ijonly) {
1835     ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
1836     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1837     ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
1838     for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1839 
1840     ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
1841     {
1842       for (i=0; i<nrqr; i++) {
1843         rbuf1_i   = rbuf1[i];
1844         sbuf_aa_i = sbuf_aa[i];
1845         ct1       = 2*rbuf1_i[0]+1;
1846         ct2       = 0;
1847         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1848           kmax = rbuf1_i[2*j];
1849           for (k=0; k<kmax; k++,ct1++) {
1850             row    = rbuf1_i[ct1] - rstart;
1851             nzA    = a_i[row+1] - a_i[row];
1852             nzB    = b_i[row+1] - b_i[row];
1853             ncols  = nzA + nzB;
1854             cworkB = b_j + b_i[row];
1855             vworkA = a_a + a_i[row]*bs2;
1856             vworkB = b_a + b_i[row]*bs2;
1857 
1858             /* load the column values for this row into vals*/
1859             vals = sbuf_aa_i+ct2*bs2;
1860             for (l=0; l<nzB; l++) {
1861               if ((bmap[cworkB[l]]) < cstart) {
1862                 ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1863               } else break;
1864             }
1865             imark = l;
1866             for (l=0; l<nzA; l++) {
1867               ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1868             }
1869             for (l=imark; l<nzB; l++) {
1870               ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1871             }
1872             ct2 += ncols;
1873           }
1874         }
1875         ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_MATSCALAR,req_source[i],tag3,comm,s_waits4+i);CHKERRQ(ierr);
1876       }
1877     }
1878     ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
1879     ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
1880   }
1881   ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
1882   ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1883 
1884   /* Form the matrix */
1885   /* create col map: global col of C -> local col of submatrices */
1886   {
1887     const PetscInt *icol_i;
1888 #if defined(PETSC_USE_CTABLE)
1889     ierr = PetscMalloc1(1+ismax,&cmap);CHKERRQ(ierr);
1890     for (i=0; i<ismax; i++) {
1891       if (!allcolumns[i]) {
1892         ierr   = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
1893         jmax   = ncol[i];
1894         icol_i = icol[i];
1895         cmap_i = cmap[i];
1896         for (j=0; j<jmax; j++) {
1897           ierr = PetscTableAdd(cmap_i,icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1898         }
1899       } else {
1900         cmap[i] = NULL;
1901       }
1902     }
1903 #else
1904     ierr = PetscMalloc1(ismax,&cmap);CHKERRQ(ierr);
1905     for (i=0; i<ismax; i++) {
1906       if (!allcolumns[i]) {
1907         ierr   = PetscCalloc1(c->Nbs,&cmap[i]);CHKERRQ(ierr);
1908         jmax   = ncol[i];
1909         icol_i = icol[i];
1910         cmap_i = cmap[i];
1911         for (j=0; j<jmax; j++) {
1912           cmap_i[icol_i[j]] = j+1;
1913         }
1914       } else { /* allcolumns[i] */
1915         cmap[i] = NULL;
1916       }
1917     }
1918 #endif
1919   }
1920 
1921   /* Create lens which is required for MatCreate... */
1922   for (i=0,j=0; i<ismax; i++) j += nrow[i];
1923   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ j*sizeof(PetscInt),&lens);CHKERRQ(ierr);
1924   lens[0] = (PetscInt*)(lens + ismax);
1925   ierr    = PetscMemzero(lens[0],j*sizeof(PetscInt));CHKERRQ(ierr);
1926   for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1927 
1928   /* Update lens from local data */
1929   for (i=0; i<ismax; i++) {
1930     jmax = nrow[i];
1931     if (!allcolumns[i]) cmap_i = cmap[i];
1932     irow_i = irow[i];
1933     lens_i = lens[i];
1934     for (j=0; j<jmax; j++) {
1935       if (allrows[i]) row = j;
1936       else row = irow_i[j];
1937 
1938 #if defined(PETSC_USE_CTABLE)
1939       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1940 #else
1941       proc = rtable[row];
1942 #endif
1943       if (proc == rank) {
1944         /* Get indices from matA and then from matB */
1945         row    = row - rstart;
1946         nzA    = a_i[row+1] - a_i[row];
1947         nzB    = b_i[row+1] - b_i[row];
1948         cworkA =  a_j + a_i[row];
1949         cworkB = b_j + b_i[row];
1950         if (!allcolumns[i]) {
1951 #if defined(PETSC_USE_CTABLE)
1952           for (k=0; k<nzA; k++) {
1953             ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1954             if (tt) lens_i[j]++;
1955           }
1956           for (k=0; k<nzB; k++) {
1957             ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1958             if (tt) lens_i[j]++;
1959           }
1960 
1961 #else
1962           for (k=0; k<nzA; k++) {
1963             if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1964           }
1965           for (k=0; k<nzB; k++) {
1966             if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1967           }
1968 #endif
1969         } else { /* allcolumns */
1970           lens_i[j] = nzA + nzB;
1971         }
1972       }
1973     }
1974   }
1975 #if defined(PETSC_USE_CTABLE)
1976   /* Create row map*/
1977   ierr = PetscMalloc1(1+ismax,&rmap);CHKERRQ(ierr);
1978   for (i=0; i<ismax; i++) {
1979     ierr = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1980   }
1981 #else
1982   /* Create row map*/
1983   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ ismax*Mbs*sizeof(PetscInt),&rmap);CHKERRQ(ierr);
1984   rmap[0] = (PetscInt*)(rmap + ismax);
1985   ierr    = PetscMemzero(rmap[0],ismax*Mbs*sizeof(PetscInt));CHKERRQ(ierr);
1986   for (i=1; i<ismax; i++) rmap[i] = rmap[i-1] + Mbs;
1987 #endif
1988   for (i=0; i<ismax; i++) {
1989     irow_i = irow[i];
1990     jmax   = nrow[i];
1991 #if defined(PETSC_USE_CTABLE)
1992     rmap_i = rmap[i];
1993     for (j=0; j<jmax; j++) {
1994       if (allrows[i]) {
1995         ierr = PetscTableAdd(rmap_i,j+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1996       } else {
1997         ierr = PetscTableAdd(rmap_i,irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1998       }
1999     }
2000 #else
2001     rmap_i = rmap[i];
2002     for (j=0; j<jmax; j++) {
2003       if (allrows[i]) rmap_i[j] = j;
2004       else rmap_i[irow_i[j]] = j;
2005     }
2006 #endif
2007   }
2008 
2009   /* Update lens from offproc data */
2010   {
2011     PetscInt    *rbuf2_i,*rbuf3_i,*sbuf1_i;
2012     PetscMPIInt ii;
2013 
2014     for (tmp2=0; tmp2<nrqs; tmp2++) {
2015       ierr    = MPI_Waitany(nrqs,r_waits3,&ii,r_status3+tmp2);CHKERRQ(ierr);
2016       idex    = pa[ii];
2017       sbuf1_i = sbuf1[idex];
2018       jmax    = sbuf1_i[0];
2019       ct1     = 2*jmax+1;
2020       ct2     = 0;
2021       rbuf2_i = rbuf2[ii];
2022       rbuf3_i = rbuf3[ii];
2023       for (j=1; j<=jmax; j++) {
2024         is_no  = sbuf1_i[2*j-1];
2025         max1   = sbuf1_i[2*j];
2026         lens_i = lens[is_no];
2027         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
2028         rmap_i = rmap[is_no];
2029         for (k=0; k<max1; k++,ct1++) {
2030 #if defined(PETSC_USE_CTABLE)
2031           ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
2032           row--;
2033           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2034 #else
2035           row = rmap_i[sbuf1_i[ct1]];  /* the val in the new matrix to be */
2036 #endif
2037           max2 = rbuf2_i[ct1];
2038           for (l=0; l<max2; l++,ct2++) {
2039             if (!allcolumns[is_no]) {
2040 #if defined(PETSC_USE_CTABLE)
2041               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tt);CHKERRQ(ierr);
2042               if (tt) lens_i[row]++;
2043 #else
2044               if (cmap_i[rbuf3_i[ct2]]) lens_i[row]++;
2045 #endif
2046             } else { /* allcolumns */
2047               lens_i[row]++;
2048             }
2049           }
2050         }
2051       }
2052     }
2053   }
2054   ierr = PetscFree(r_status3);CHKERRQ(ierr);
2055   ierr = PetscFree(r_waits3);CHKERRQ(ierr);
2056   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
2057   ierr = PetscFree(s_status3);CHKERRQ(ierr);
2058   ierr = PetscFree(s_waits3);CHKERRQ(ierr);
2059 
2060   /* Create the submatrices */
2061   if (scall == MAT_REUSE_MATRIX) {
2062     if (ijonly) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," MAT_REUSE_MATRIX and ijonly is not supported yet");
2063     /*
2064         Assumes new rows are same length as the old rows, hence bug!
2065     */
2066     for (i=0; i<ismax; i++) {
2067       mat = (Mat_SeqBAIJ*)(submats[i]->data);
2068       if ((mat->mbs != nrow[i]) || (mat->nbs != ncol[i] || C->rmap->bs != bs)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
2069       ierr = PetscMemcmp(mat->ilen,lens[i],mat->mbs *sizeof(PetscInt),&flag);CHKERRQ(ierr);
2070       if (!flag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Cannot reuse matrix. wrong no of nonzeros");
2071       /* Initial matrix as if empty */
2072       ierr = PetscMemzero(mat->ilen,mat->mbs*sizeof(PetscInt));CHKERRQ(ierr);
2073 
2074       submats[i]->factortype = C->factortype;
2075     }
2076   } else {
2077     PetscInt bs_tmp;
2078     if (ijonly) bs_tmp = 1;
2079     else        bs_tmp = bs;
2080     for (i=0; i<ismax; i++) {
2081       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
2082       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,nrow[i]*bs_tmp,ncol[i]*bs_tmp);CHKERRQ(ierr);
2083       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
2084       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
2085       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
2086     }
2087   }
2088 
2089   /* Assemble the matrices */
2090   /* First assemble the local rows */
2091   {
2092     PetscInt  ilen_row,*imat_ilen,*imat_j,*imat_i;
2093     MatScalar *imat_a = NULL;
2094 
2095     for (i=0; i<ismax; i++) {
2096       mat       = (Mat_SeqBAIJ*)submats[i]->data;
2097       imat_ilen = mat->ilen;
2098       imat_j    = mat->j;
2099       imat_i    = mat->i;
2100       if (!ijonly) imat_a = mat->a;
2101       if (!allcolumns[i]) cmap_i = cmap[i];
2102       rmap_i = rmap[i];
2103       irow_i = irow[i];
2104       jmax   = nrow[i];
2105       for (j=0; j<jmax; j++) {
2106         if (allrows[i]) row = j;
2107         else row = irow_i[j];
2108 
2109 #if defined(PETSC_USE_CTABLE)
2110         ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
2111 #else
2112         proc = rtable[row];
2113 #endif
2114         if (proc == rank) {
2115           row    = row - rstart;
2116           nzA    = a_i[row+1] - a_i[row];
2117           nzB    = b_i[row+1] - b_i[row];
2118           cworkA = a_j + a_i[row];
2119           cworkB = b_j + b_i[row];
2120           if (!ijonly) {
2121             vworkA = a_a + a_i[row]*bs2;
2122             vworkB = b_a + b_i[row]*bs2;
2123           }
2124 #if defined(PETSC_USE_CTABLE)
2125           ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
2126           row--;
2127           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2128 #else
2129           row = rmap_i[row + rstart];
2130 #endif
2131           mat_i = imat_i[row];
2132           if (!ijonly) mat_a = imat_a + mat_i*bs2;
2133           mat_j    = imat_j + mat_i;
2134           ilen_row = imat_ilen[row];
2135 
2136           /* load the column indices for this row into cols*/
2137           if (!allcolumns[i]) {
2138             for (l=0; l<nzB; l++) {
2139               if ((ctmp = bmap[cworkB[l]]) < cstart) {
2140 #if defined(PETSC_USE_CTABLE)
2141                 ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
2142                 if (tcol) {
2143 #else
2144                 if ((tcol = cmap_i[ctmp])) {
2145 #endif
2146                   *mat_j++ = tcol - 1;
2147                   ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2148                   mat_a   += bs2;
2149                   ilen_row++;
2150                 }
2151               } else break;
2152             }
2153             imark = l;
2154             for (l=0; l<nzA; l++) {
2155 #if defined(PETSC_USE_CTABLE)
2156               ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
2157               if (tcol) {
2158 #else
2159               if ((tcol = cmap_i[cstart + cworkA[l]])) {
2160 #endif
2161                 *mat_j++ = tcol - 1;
2162                 if (!ijonly) {
2163                   ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2164                   mat_a += bs2;
2165                 }
2166                 ilen_row++;
2167               }
2168             }
2169             for (l=imark; l<nzB; l++) {
2170 #if defined(PETSC_USE_CTABLE)
2171               ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
2172               if (tcol) {
2173 #else
2174               if ((tcol = cmap_i[bmap[cworkB[l]]])) {
2175 #endif
2176                 *mat_j++ = tcol - 1;
2177                 if (!ijonly) {
2178                   ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2179                   mat_a += bs2;
2180                 }
2181                 ilen_row++;
2182               }
2183             }
2184           } else { /* allcolumns */
2185             for (l=0; l<nzB; l++) {
2186               if ((ctmp = bmap[cworkB[l]]) < cstart) {
2187                 *mat_j++ = ctmp;
2188                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2189                 mat_a   += bs2;
2190                 ilen_row++;
2191               } else break;
2192             }
2193             imark = l;
2194             for (l=0; l<nzA; l++) {
2195               *mat_j++ = cstart+cworkA[l];
2196               if (!ijonly) {
2197                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2198                 mat_a += bs2;
2199               }
2200               ilen_row++;
2201             }
2202             for (l=imark; l<nzB; l++) {
2203               *mat_j++ = bmap[cworkB[l]];
2204               if (!ijonly) {
2205                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2206                 mat_a += bs2;
2207               }
2208               ilen_row++;
2209             }
2210           }
2211           imat_ilen[row] = ilen_row;
2212         }
2213       }
2214     }
2215   }
2216 
2217   /*   Now assemble the off proc rows*/
2218   {
2219     PetscInt    *sbuf1_i,*rbuf2_i,*rbuf3_i,*imat_ilen,ilen;
2220     PetscInt    *imat_j,*imat_i;
2221     MatScalar   *imat_a = NULL,*rbuf4_i = NULL;
2222     PetscMPIInt ii;
2223 
2224     for (tmp2=0; tmp2<nrqs; tmp2++) {
2225       if (ijonly) ii = tmp2;
2226       else {
2227         ierr = MPI_Waitany(nrqs,r_waits4,&ii,r_status4+tmp2);CHKERRQ(ierr);
2228       }
2229       idex    = pa[ii];
2230       sbuf1_i = sbuf1[idex];
2231       jmax    = sbuf1_i[0];
2232       ct1     = 2*jmax + 1;
2233       ct2     = 0;
2234       rbuf2_i = rbuf2[ii];
2235       rbuf3_i = rbuf3[ii];
2236       if (!ijonly) rbuf4_i = rbuf4[ii];
2237       for (j=1; j<=jmax; j++) {
2238         is_no = sbuf1_i[2*j-1];
2239         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
2240         rmap_i    = rmap[is_no];
2241         mat       = (Mat_SeqBAIJ*)submats[is_no]->data;
2242         imat_ilen = mat->ilen;
2243         imat_j    = mat->j;
2244         imat_i    = mat->i;
2245         if (!ijonly) imat_a = mat->a;
2246         max1 = sbuf1_i[2*j];
2247         for (k=0; k<max1; k++,ct1++) {
2248           row = sbuf1_i[ct1];
2249 #if defined(PETSC_USE_CTABLE)
2250           ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
2251           row--;
2252           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2253 #else
2254           row = rmap_i[row];
2255 #endif
2256           ilen  = imat_ilen[row];
2257           mat_i = imat_i[row];
2258           if (!ijonly) mat_a = imat_a + mat_i*bs2;
2259           mat_j = imat_j + mat_i;
2260           max2  = rbuf2_i[ct1];
2261 
2262           if (!allcolumns[is_no]) {
2263             for (l=0; l<max2; l++,ct2++) {
2264 #if defined(PETSC_USE_CTABLE)
2265               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
2266               if (tcol) {
2267 #else
2268               if ((tcol = cmap_i[rbuf3_i[ct2]])) {
2269 #endif
2270                 *mat_j++ = tcol - 1;
2271                 if (!ijonly) {
2272                   ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2273                   mat_a += bs2;
2274                 }
2275                 ilen++;
2276               }
2277             }
2278           } else { /* allcolumns */
2279             for (l=0; l<max2; l++,ct2++) {
2280               *mat_j++ = rbuf3_i[ct2];
2281               if (!ijonly) {
2282                 ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2283                 mat_a += bs2;
2284               }
2285               ilen++;
2286             }
2287           }
2288           imat_ilen[row] = ilen;
2289         }
2290       }
2291     }
2292   }
2293   /* sort the rows */
2294   {
2295     PetscInt  ilen_row,*imat_ilen,*imat_j,*imat_i;
2296     MatScalar *imat_a = NULL;
2297     MatScalar *work;
2298 
2299     ierr = PetscMalloc1(bs2,&work);CHKERRQ(ierr);
2300     for (i=0; i<ismax; i++) {
2301       mat       = (Mat_SeqBAIJ*)submats[i]->data;
2302       imat_ilen = mat->ilen;
2303       imat_j    = mat->j;
2304       imat_i    = mat->i;
2305       if (!ijonly) imat_a = mat->a;
2306       if (allcolumns[i]) continue;
2307       jmax   = nrow[i];
2308       for (j=0; j<jmax; j++) {
2309         mat_i = imat_i[j];
2310         if (!ijonly) mat_a = imat_a + mat_i*bs2;
2311         mat_j    = imat_j + mat_i;
2312         ilen_row = imat_ilen[j];
2313         if (!ijonly) {ierr = PetscSortIntWithDataArray(ilen_row,mat_j,mat_a,bs2*sizeof(MatScalar),work);CHKERRQ(ierr);}
2314         else {ierr = PetscSortInt(ilen_row,mat_j);CHKERRQ(ierr);}
2315       }
2316     }
2317     ierr = PetscFree(work);CHKERRQ(ierr);
2318   }
2319   if (!ijonly) {
2320     ierr = PetscFree(r_status4);CHKERRQ(ierr);
2321     ierr = PetscFree(r_waits4);CHKERRQ(ierr);
2322     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
2323     ierr = PetscFree(s_waits4);CHKERRQ(ierr);
2324     ierr = PetscFree(s_status4);CHKERRQ(ierr);
2325   }
2326 
2327   /* Restore the indices */
2328   for (i=0; i<ismax; i++) {
2329     if (!allrows[i]) {
2330       ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
2331     }
2332     if (!allcolumns[i]) {
2333       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
2334     }
2335   }
2336 
2337   /* Destroy allocated memory */
2338 #if defined(PETSC_USE_CTABLE)
2339   ierr = PetscFree4(irow,icol,nrow,ncol);CHKERRQ(ierr);
2340 #else
2341   ierr = PetscFree5(irow,icol,nrow,ncol,rtable);CHKERRQ(ierr);
2342 #endif
2343   ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
2344   ierr = PetscFree(pa);CHKERRQ(ierr);
2345 
2346   ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
2347   ierr = PetscFree(sbuf1);CHKERRQ(ierr);
2348   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
2349   for (i=0; i<nrqr; ++i) {
2350     ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
2351   }
2352   for (i=0; i<nrqs; ++i) {
2353     ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
2354   }
2355   ierr = PetscFree3(sbuf2,req_size,req_source);CHKERRQ(ierr);
2356   ierr = PetscFree(rbuf3);CHKERRQ(ierr);
2357   ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
2358   ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
2359   if (!ijonly) {
2360     for (i=0; i<nrqs; ++i) {ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);}
2361     ierr = PetscFree(rbuf4);CHKERRQ(ierr);
2362     ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
2363     ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
2364   }
2365 
2366 #if defined(PETSC_USE_CTABLE)
2367   for (i=0; i<ismax; i++) {
2368     ierr = PetscTableDestroy((PetscTable*)&rmap[i]);CHKERRQ(ierr);
2369   }
2370 #endif
2371   ierr = PetscFree(rmap);CHKERRQ(ierr);
2372 
2373   for (i=0; i<ismax; i++) {
2374     if (!allcolumns[i]) {
2375 #if defined(PETSC_USE_CTABLE)
2376       ierr = PetscTableDestroy((PetscTable*)&cmap[i]);CHKERRQ(ierr);
2377 #else
2378       ierr = PetscFree(cmap[i]);CHKERRQ(ierr);
2379 #endif
2380     }
2381   }
2382   ierr = PetscFree(cmap);CHKERRQ(ierr);
2383   ierr = PetscFree(lens);CHKERRQ(ierr);
2384 
2385   for (i=0; i<ismax; i++) {
2386     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2387     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2388   }
2389 
2390   c->ijonly = PETSC_FALSE; /* set back to the default */
2391   PetscFunctionReturn(0);
2392 }
2393 
2394