xref: /petsc/src/mat/impls/baij/mpi/baijov.c (revision 9e686edcc510731859ac0c7d39046afbc71c7231)
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 */
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     if (colflag && ncol[i] == C->cmap->N) {
714       allcolumns[i] = PETSC_TRUE;
715       icol[i] = NULL;
716     } else {
717       allcolumns[i] = PETSC_FALSE;
718       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
719     }
720   }
721 
722   if (scall == MAT_REUSE_MATRIX) {
723     /* Assumes new rows are same length as the old rows */
724     for (i=0; i<ismax; i++) {
725       subc = (Mat_SeqBAIJ*)(submats[i]->data);
726       if (subc->mbs != nrow[i] || subc->nbs != ncol[i]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
727 
728       /* Initial matrix as if empty */
729       ierr = PetscMemzero(subc->ilen,subc->mbs*sizeof(PetscInt));CHKERRQ(ierr);
730 
731       /* Initial matrix as if empty */
732       submats[i]->factortype = C->factortype;
733 
734       smat_i   = subc->submatis1;
735       smats[i] = smat_i;
736 
737       nrqs        = smat_i->nrqs;
738       nrqr        = smat_i->nrqr;
739       rbuf1       = smat_i->rbuf1;
740       rbuf2       = smat_i->rbuf2;
741       rbuf3       = smat_i->rbuf3;
742       req_source2 = smat_i->req_source2;
743 
744       sbuf1     = smat_i->sbuf1;
745       sbuf2     = smat_i->sbuf2;
746       ptr       = smat_i->ptr;
747       tmp       = smat_i->tmp;
748       ctr       = smat_i->ctr;
749 
750       pa          = smat_i->pa;
751       req_size    = smat_i->req_size;
752       req_source1 = smat_i->req_source1;
753 
754       allcolumns[i] = smat_i->allcolumns;
755       row2proc[i]   = smat_i->row2proc;
756       rmap[i]       = smat_i->rmap;
757       cmap[i]       = smat_i->cmap;
758     }
759   } else { /* scall == MAT_INITIAL_MATRIX */
760     /* Get some new tags to keep the communication clean */
761     ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
762     ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
763 
764     /* evaluate communication - mesg to who, length of mesg, and buffer space
765      required. Based on this, buffers are allocated, and data copied into them*/
766     ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);   /* mesg size, initialize work vectors */
767 
768     for (i=0; i<ismax; i++) {
769       jmax   = nrow[i];
770       irow_i = irow[i];
771 
772       ierr   = PetscMalloc1(jmax,&row2proc_i);CHKERRQ(ierr);
773       row2proc[i] = row2proc_i;
774 
775       if (issorted[i]) proc = 0;
776       for (j=0; j<jmax; j++) {
777         if (!issorted[i]) proc = 0;
778         row = irow_i[j];
779         while (row >= c->rangebs[proc+1]) proc++;
780         w4[proc]++;
781         row2proc_i[j] = proc; /* map row index to proc */
782       }
783       for (j=0; j<size; j++) {
784         if (w4[j]) { w1[j] += w4[j];  w3[j]++; w4[j] = 0;}
785       }
786     }
787 
788     nrqs     = 0;              /* no of outgoing messages */
789     msz      = 0;              /* total mesg length (for all procs) */
790     w1[rank] = 0;              /* no mesg sent to self */
791     w3[rank] = 0;
792     for (i=0; i<size; i++) {
793       if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
794     }
795     ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
796     for (i=0,j=0; i<size; i++) {
797       if (w1[i]) { pa[j] = i; j++; }
798     }
799 
800     /* Each message would have a header = 1 + 2*(no of IS) + data */
801     for (i=0; i<nrqs; i++) {
802       j      = pa[i];
803       w1[j] += w2[j] + 2* w3[j];
804       msz   += w1[j];
805     }
806     ierr = PetscInfo2(0,"Number of outgoing messages %D Total message length %D\n",nrqs,msz);CHKERRQ(ierr);
807 
808     /* Determine the number of messages to expect, their lengths, from from-ids */
809     ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
810     ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
811 
812     /* Now post the Irecvs corresponding to these messages */
813     tag0 = ((PetscObject)C)->tag;
814     ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
815 
816     ierr = PetscFree(onodes1);CHKERRQ(ierr);
817     ierr = PetscFree(olengths1);CHKERRQ(ierr);
818 
819     /* Allocate Memory for outgoing messages */
820     ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
821     ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
822     ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
823 
824     {
825       PetscInt *iptr = tmp;
826       k    = 0;
827       for (i=0; i<nrqs; i++) {
828         j        = pa[i];
829         iptr    += k;
830         sbuf1[j] = iptr;
831         k        = w1[j];
832       }
833     }
834 
835     /* Form the outgoing messages. Initialize the header space */
836     for (i=0; i<nrqs; i++) {
837       j           = pa[i];
838       sbuf1[j][0] = 0;
839       ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
840       ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
841     }
842 
843     /* Parse the isrow and copy data into outbuf */
844     for (i=0; i<ismax; i++) {
845       row2proc_i = row2proc[i];
846       ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
847       irow_i = irow[i];
848       jmax   = nrow[i];
849       for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
850         proc = row2proc_i[j];
851         if (proc != rank) { /* copy to the outgoing buf*/
852           ctr[proc]++;
853           *ptr[proc] = irow_i[j];
854           ptr[proc]++;
855         }
856       }
857       /* Update the headers for the current IS */
858       for (j=0; j<size; j++) { /* Can Optimise this loop too */
859         if ((ctr_j = ctr[j])) {
860           sbuf1_j        = sbuf1[j];
861           k              = ++sbuf1_j[0];
862           sbuf1_j[2*k]   = ctr_j;
863           sbuf1_j[2*k-1] = i;
864         }
865       }
866     }
867 
868     /*  Now  post the sends */
869     ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
870     for (i=0; i<nrqs; ++i) {
871       j    = pa[i];
872       ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
873     }
874 
875     /* Post Receives to capture the buffer size */
876     ierr = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
877     ierr = PetscMalloc3(nrqs+1,&req_source2,nrqs+1,&rbuf2,nrqs+1,&rbuf3);CHKERRQ(ierr);
878     rbuf2[0] = tmp + msz;
879     for (i=1; i<nrqs; ++i) {
880       rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
881     }
882     for (i=0; i<nrqs; ++i) {
883       j    = pa[i];
884       ierr = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag2,comm,r_waits2+i);CHKERRQ(ierr);
885     }
886 
887     /* Send to other procs the buf size they should allocate */
888     /* Receive messages*/
889     ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
890     ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
891     ierr = PetscMalloc3(nrqr,&sbuf2,nrqr,&req_size,nrqr,&req_source1);CHKERRQ(ierr);
892     {
893       PetscInt   *sAi = a->i,*sBi = b->i,id;
894       PetscInt   *sbuf2_i;
895 
896       ierr = MPI_Waitall(nrqr,r_waits1,r_status1);CHKERRQ(ierr);
897       for (i=0; i<nrqr; ++i) {
898         req_size[i] = 0;
899         rbuf1_i        = rbuf1[i];
900         start          = 2*rbuf1_i[0] + 1;
901         ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
902         ierr           = PetscMalloc1(end+1,&sbuf2[i]);CHKERRQ(ierr);
903         sbuf2_i        = sbuf2[i];
904         for (j=start; j<end; j++) {
905           id              = rbuf1_i[j] - rstart;
906           ncols           = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
907           sbuf2_i[j]      = ncols;
908           req_size[i] += ncols;
909         }
910         req_source1[i] = r_status1[i].MPI_SOURCE;
911         /* form the header */
912         sbuf2_i[0] = req_size[i];
913         for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
914 
915         ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source1[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
916       }
917     }
918     ierr = PetscFree(r_status1);CHKERRQ(ierr);
919     ierr = PetscFree(r_waits1);CHKERRQ(ierr);
920     ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
921 
922     /* Receive messages*/
923     ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
924     ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
925 
926     ierr = MPI_Waitall(nrqs,r_waits2,r_status2);CHKERRQ(ierr);
927     for (i=0; i<nrqs; ++i) {
928       ierr = PetscMalloc1(rbuf2[i][0]+1,&rbuf3[i]);CHKERRQ(ierr);
929       req_source2[i] = r_status2[i].MPI_SOURCE;
930       ierr = MPI_Irecv(rbuf3[i],rbuf2[i][0],MPIU_INT,req_source2[i],tag3,comm,r_waits3+i);CHKERRQ(ierr);
931     }
932     ierr = PetscFree(r_status2);CHKERRQ(ierr);
933     ierr = PetscFree(r_waits2);CHKERRQ(ierr);
934 
935     /* Wait on sends1 and sends2 */
936     ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
937     ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
938 
939     if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
940     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
941     ierr = PetscFree(s_status1);CHKERRQ(ierr);
942     ierr = PetscFree(s_status2);CHKERRQ(ierr);
943     ierr = PetscFree(s_waits1);CHKERRQ(ierr);
944     ierr = PetscFree(s_waits2);CHKERRQ(ierr);
945 
946     /* Now allocate sending buffers for a->j, and send them off */
947     ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
948     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
949     ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
950     for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
951 
952     ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
953     {
954 
955       for (i=0; i<nrqr; i++) {
956         rbuf1_i   = rbuf1[i];
957         sbuf_aj_i = sbuf_aj[i];
958         ct1       = 2*rbuf1_i[0] + 1;
959         ct2       = 0;
960         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
961           kmax = rbuf1[i][2*j];
962           for (k=0; k<kmax; k++,ct1++) {
963             row    = rbuf1_i[ct1] - rstart;
964             nzA    = a_i[row+1] - a_i[row]; nzB = b_i[row+1] - b_i[row];
965             ncols  = nzA + nzB;
966             cworkA = a_j + a_i[row]; cworkB = b_j + b_i[row];
967 
968             /* load the column indices for this row into cols */
969             cols = sbuf_aj_i + ct2;
970             for (l=0; l<nzB; l++) {
971               if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
972               else break;
973             }
974             imark = l;
975             for (l=0; l<nzA; l++) {cols[imark+l] = cstart + cworkA[l];}
976             for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
977             ct2 += ncols;
978           }
979         }
980         ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source1[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
981       }
982     }
983     ierr = PetscMalloc2(nrqs+1,&r_status3,nrqr+1,&s_status3);CHKERRQ(ierr);
984 
985     /* create col map: global col of C -> local col of submatrices */
986     const PetscInt *icol_i;
987 #if defined(PETSC_USE_CTABLE)
988     for (i=0; i<ismax; i++) {
989       if (!allcolumns[i]) {
990         ierr = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
991 
992         jmax   = ncol[i];
993         icol_i = icol[i];
994         cmap_i = cmap[i];
995         for (j=0; j<jmax; j++) {
996           ierr = PetscTableAdd(cmap[i],icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
997         }
998       } else cmap[i] = NULL;
999     }
1000 #else
1001     for (i=0; i<ismax; i++) {
1002       if (!allcolumns[i]) {
1003         ierr   = PetscCalloc1(c->Nbs,&cmap[i]);CHKERRQ(ierr);
1004         jmax   = ncol[i];
1005         icol_i = icol[i];
1006         cmap_i = cmap[i];
1007         for (j=0; j<jmax; j++) cmap_i[icol_i[j]] = j+1;
1008       } else cmap[i] = NULL;
1009     }
1010 #endif
1011 
1012     /* Create lens which is required for MatCreate... */
1013     for (i=0,j=0; i<ismax; i++) j += nrow[i];
1014     ierr = PetscMalloc1(ismax,&lens);CHKERRQ(ierr);
1015 
1016     if (ismax) {
1017       ierr = PetscCalloc1(j,&lens[0]);CHKERRQ(ierr);
1018     }
1019     for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1020 
1021     /* Update lens from local data */
1022     for (i=0; i<ismax; i++) {
1023       row2proc_i = row2proc[i];
1024       jmax = nrow[i];
1025       if (!allcolumns[i]) cmap_i = cmap[i];
1026       irow_i = irow[i];
1027       lens_i = lens[i];
1028       for (j=0; j<jmax; j++) {
1029         row = irow_i[j]; /* global blocked row of C */
1030         proc = row2proc_i[j];
1031         if (proc == rank) {
1032           /* Get indices from matA and then from matB */
1033 #if defined(PETSC_USE_CTABLE)
1034           PetscInt   tt;
1035 #endif
1036           row    = row - rstart;
1037           nzA    = a_i[row+1] - a_i[row];
1038           nzB    = b_i[row+1] - b_i[row];
1039           cworkA =  a_j + a_i[row];
1040           cworkB = b_j + b_i[row];
1041 
1042           if (!allcolumns[i]) {
1043 #if defined(PETSC_USE_CTABLE)
1044             for (k=0; k<nzA; k++) {
1045               ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1046               if (tt) lens_i[j]++;
1047             }
1048             for (k=0; k<nzB; k++) {
1049               ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1050               if (tt) lens_i[j]++;
1051             }
1052 
1053 #else
1054             for (k=0; k<nzA; k++) {
1055               if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1056             }
1057             for (k=0; k<nzB; k++) {
1058               if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1059             }
1060 #endif
1061           } else { /* allcolumns */
1062             lens_i[j] = nzA + nzB;
1063           }
1064         }
1065       }
1066     }
1067 
1068     /* Create row map: global row of C -> local row of submatrices */
1069 #if defined(PETSC_USE_CTABLE)
1070     for (i=0; i<ismax; i++) {
1071       ierr   = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1072       irow_i = irow[i];
1073       jmax   = nrow[i];
1074       for (j=0; j<jmax; j++) {
1075       ierr = PetscTableAdd(rmap[i],irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1076       }
1077     }
1078 #else
1079     for (i=0; i<ismax; i++) {
1080       ierr   = PetscCalloc1(c->Mbs,&rmap[i]);CHKERRQ(ierr);
1081       rmap_i = rmap[i];
1082       irow_i = irow[i];
1083       jmax   = nrow[i];
1084       for (j=0; j<jmax; j++) {
1085         rmap_i[irow_i[j]] = j;
1086       }
1087     }
1088 #endif
1089 
1090     /* Update lens from offproc data */
1091     {
1092       PetscInt *rbuf2_i,*rbuf3_i,*sbuf1_i;
1093 
1094       ierr    = MPI_Waitall(nrqs,r_waits3,r_status3);CHKERRQ(ierr);
1095       for (tmp2=0; tmp2<nrqs; tmp2++) {
1096         sbuf1_i = sbuf1[pa[tmp2]];
1097         jmax    = sbuf1_i[0];
1098         ct1     = 2*jmax+1;
1099         ct2     = 0;
1100         rbuf2_i = rbuf2[tmp2];
1101         rbuf3_i = rbuf3[tmp2];
1102         for (j=1; j<=jmax; j++) {
1103           is_no  = sbuf1_i[2*j-1];
1104           max1   = sbuf1_i[2*j];
1105           lens_i = lens[is_no];
1106           if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1107           rmap_i = rmap[is_no];
1108           for (k=0; k<max1; k++,ct1++) {
1109 #if defined(PETSC_USE_CTABLE)
1110             ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
1111             row--;
1112             if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1113 #else
1114             row = rmap_i[sbuf1_i[ct1]]; /* the val in the new matrix to be */
1115 #endif
1116             max2 = rbuf2_i[ct1];
1117             for (l=0; l<max2; l++,ct2++) {
1118               if (!allcolumns[is_no]) {
1119 #if defined(PETSC_USE_CTABLE)
1120                 ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1121 #else
1122                 tcol = cmap_i[rbuf3_i[ct2]];
1123 #endif
1124                 if (tcol) lens_i[row]++;
1125               } else { /* allcolumns */
1126                 lens_i[row]++; /* lens_i[row] += max2 ? */
1127               }
1128             }
1129           }
1130         }
1131       }
1132     }
1133     ierr = PetscFree(r_waits3);CHKERRQ(ierr);
1134     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
1135     ierr = PetscFree2(r_status3,s_status3);CHKERRQ(ierr);
1136     ierr = PetscFree(s_waits3);CHKERRQ(ierr);
1137 
1138     /* Create the submatrices */
1139     for (i=0; i<ismax; i++) {
1140       PetscInt bs_tmp;
1141       if (ijonly) bs_tmp = 1;
1142       else        bs_tmp = bs;
1143 
1144       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
1145       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
1146 
1147       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
1148       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
1149       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
1150 
1151       /* create struct Mat_SubMat and attached it to submat */
1152       ierr = PetscNew(&smat_i);CHKERRQ(ierr);
1153       subc = (Mat_SeqBAIJ*)submats[i]->data;
1154       subc->submatis1 = smat_i;
1155       smats[i]        = smat_i;
1156 
1157       smat_i->destroy          = submats[i]->ops->destroy;
1158       submats[i]->ops->destroy = MatDestroy_MPIBAIJ_MatGetSubmatrices;
1159       submats[i]->factortype   = C->factortype;
1160 
1161       smat_i->id          = i;
1162       smat_i->nrqs        = nrqs;
1163       smat_i->nrqr        = nrqr;
1164       smat_i->rbuf1       = rbuf1;
1165       smat_i->rbuf2       = rbuf2;
1166       smat_i->rbuf3       = rbuf3;
1167       smat_i->sbuf2       = sbuf2;
1168       smat_i->req_source2 = req_source2;
1169 
1170       smat_i->sbuf1       = sbuf1;
1171       smat_i->ptr         = ptr;
1172       smat_i->tmp         = tmp;
1173       smat_i->ctr         = ctr;
1174 
1175       smat_i->pa           = pa;
1176       smat_i->req_size     = req_size;
1177       smat_i->req_source1  = req_source1;
1178 
1179       smat_i->allcolumns  = allcolumns[i];
1180       smat_i->singleis    = PETSC_FALSE;
1181       smat_i->row2proc    = row2proc[i];
1182       smat_i->rmap        = rmap[i];
1183       smat_i->cmap        = cmap[i];
1184     }
1185 
1186     if (ismax) {ierr = PetscFree(lens[0]);CHKERRQ(ierr);}
1187     ierr = PetscFree(lens);CHKERRQ(ierr);
1188     ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
1189     ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
1190 
1191   } /* endof scall == MAT_INITIAL_MATRIX */
1192 
1193   /* Post recv matrix values */
1194   ierr = PetscObjectGetNewTag((PetscObject)C,&tag4);CHKERRQ(ierr);
1195   ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
1196   ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
1197   ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
1198   ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
1199   for (i=0; i<nrqs; ++i) {
1200     ierr = PetscMalloc1(rbuf2[i][0]*bs2,&rbuf4[i]);CHKERRQ(ierr);
1201     ierr = MPI_Irecv(rbuf4[i],rbuf2[i][0]*bs2,MPIU_SCALAR,req_source2[i],tag4,comm,r_waits4+i);CHKERRQ(ierr);
1202   }
1203 
1204   /* Allocate sending buffers for a->a, and send them off */
1205   ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
1206   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1207 
1208   ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
1209   for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1210 
1211   ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
1212 
1213   for (i=0; i<nrqr; i++) {
1214     rbuf1_i   = rbuf1[i];
1215     sbuf_aa_i = sbuf_aa[i];
1216     ct1       = 2*rbuf1_i[0]+1;
1217     ct2       = 0;
1218     for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1219       kmax = rbuf1_i[2*j];
1220       for (k=0; k<kmax; k++,ct1++) {
1221         row    = rbuf1_i[ct1] - rstart;
1222         nzA    = a_i[row+1] - a_i[row];
1223         nzB    = b_i[row+1] - b_i[row];
1224         ncols  = nzA + nzB;
1225         cworkB = b_j + b_i[row];
1226         vworkA = a_a + a_i[row]*bs2;
1227         vworkB = b_a + b_i[row]*bs2;
1228 
1229         /* load the column values for this row into vals*/
1230         vals = sbuf_aa_i+ct2*bs2;
1231         for (l=0; l<nzB; l++) {
1232           if ((bmap[cworkB[l]]) < cstart) {
1233             ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1234           } else break;
1235         }
1236         imark = l;
1237         for (l=0; l<nzA; l++) {
1238           ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);//error in proc[1]???
1239         }
1240         for (l=imark; l<nzB; l++) {
1241           ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1242         }
1243 
1244         ct2 += ncols;
1245       }
1246     }
1247     ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_SCALAR,req_source1[i],tag4,comm,s_waits4+i);CHKERRQ(ierr);
1248   }
1249 
1250   if (!ismax) {
1251     ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
1252     ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1253   }
1254 
1255   /* Assemble the matrices */
1256   /* First assemble the local rows */
1257   for (i=0; i<ismax; i++) {
1258     row2proc_i = row2proc[i];
1259     subc      = (Mat_SeqBAIJ*)submats[i]->data;
1260     imat_ilen = subc->ilen;
1261     imat_j    = subc->j;
1262     imat_i    = subc->i;
1263     imat_a    = subc->a;
1264 
1265     if (!allcolumns[i]) cmap_i = cmap[i];
1266     rmap_i = rmap[i];
1267     irow_i = irow[i];
1268     jmax   = nrow[i];
1269     for (j=0; j<jmax; j++) {
1270       row  = irow_i[j];
1271       proc = row2proc_i[j];
1272 
1273       if (proc == rank) {
1274 
1275         row    = row - rstart;
1276         nzA    = a_i[row+1] - a_i[row];
1277         nzB    = b_i[row+1] - b_i[row];
1278         cworkA = a_j + a_i[row];
1279         cworkB = b_j + b_i[row];
1280         if (!ijonly) {
1281           vworkA = a_a + a_i[row]*bs2;
1282           vworkB = b_a + b_i[row]*bs2;
1283         }
1284 #if defined(PETSC_USE_CTABLE)
1285         ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
1286         row--;
1287         if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1288 #else
1289         row = rmap_i[row + rstart];
1290 #endif
1291         mat_i = imat_i[row];
1292         if (!ijonly) mat_a = imat_a + mat_i*bs2;
1293         mat_j    = imat_j + mat_i;
1294         ilen_row = imat_ilen[row];
1295 
1296         /* load the column indices for this row into cols*/
1297         if (!allcolumns[i]) {
1298           for (l=0; l<nzB; l++) {
1299             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1300 #if defined(PETSC_USE_CTABLE)
1301               ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
1302               if (tcol) {
1303 #else
1304               if ((tcol = cmap_i[ctmp])) {
1305 #endif
1306                 *mat_j++ = tcol - 1;
1307                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1308                 mat_a   += bs2;
1309                 ilen_row++;
1310               }
1311             } else break;
1312           }
1313           imark = l;
1314           for (l=0; l<nzA; l++) {
1315 #if defined(PETSC_USE_CTABLE)
1316             ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
1317             if (tcol) {
1318 #else
1319             if ((tcol = cmap_i[cstart + cworkA[l]])) {
1320 #endif
1321               *mat_j++ = tcol - 1;
1322               if (!ijonly) {
1323                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1324                 mat_a += bs2;
1325               }
1326               ilen_row++;
1327             }
1328           }
1329           for (l=imark; l<nzB; l++) {
1330 #if defined(PETSC_USE_CTABLE)
1331             ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
1332             if (tcol) {
1333 #else
1334             if ((tcol = cmap_i[bmap[cworkB[l]]])) {
1335 #endif
1336               *mat_j++ = tcol - 1;
1337               if (!ijonly) {
1338                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1339                 mat_a += bs2;
1340               }
1341               ilen_row++;
1342             }
1343           }
1344         } else { /* allcolumns */
1345           for (l=0; l<nzB; l++) {
1346             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1347               *mat_j++ = ctmp;
1348               ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1349               mat_a   += bs2;
1350               ilen_row++;
1351             } else break;
1352           }
1353           imark = l;
1354           for (l=0; l<nzA; l++) {
1355             *mat_j++ = cstart+cworkA[l];
1356             if (!ijonly) {
1357               ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1358               mat_a += bs2;
1359             }
1360             ilen_row++;
1361           }
1362           for (l=imark; l<nzB; l++) {
1363             *mat_j++ = bmap[cworkB[l]];
1364             if (!ijonly) {
1365               ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1366               mat_a += bs2;
1367             }
1368             ilen_row++;
1369           }
1370         }
1371         imat_ilen[row] = ilen_row;
1372       }
1373     }
1374   }
1375 
1376   /* Now assemble the off proc rows */
1377   ierr    = MPI_Waitall(nrqs,r_waits4,r_status4);CHKERRQ(ierr);
1378   for (tmp2=0; tmp2<nrqs; tmp2++) {
1379     sbuf1_i = sbuf1[pa[tmp2]];
1380     jmax    = sbuf1_i[0];
1381     ct1     = 2*jmax + 1;
1382     ct2     = 0;
1383     rbuf2_i = rbuf2[tmp2];
1384     rbuf3_i = rbuf3[tmp2];
1385     rbuf4_i = rbuf4[tmp2];
1386     for (j=1; j<=jmax; j++) {
1387       is_no     = sbuf1_i[2*j-1];
1388       rmap_i    = rmap[is_no];
1389       if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1390       subc      = (Mat_SeqBAIJ*)submats[is_no]->data;
1391       imat_ilen = subc->ilen;
1392       imat_j    = subc->j;
1393       imat_i    = subc->i;
1394       imat_a    = subc->a;
1395       max1      = sbuf1_i[2*j];
1396       for (k=0; k<max1; k++,ct1++) {
1397         row = sbuf1_i[ct1];
1398 #if defined(PETSC_USE_CTABLE)
1399         ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
1400         row--;
1401 #else
1402         row = rmap_i[row];
1403 #endif
1404         ilen  = imat_ilen[row];
1405         mat_i = imat_i[row];
1406         mat_a = imat_a + mat_i;
1407         mat_j = imat_j + mat_i;
1408         max2  = rbuf2_i[ct1];
1409         if (!allcolumns[is_no]) {
1410           for (l=0; l<max2; l++,ct2++) {
1411 #if defined(PETSC_USE_CTABLE)
1412             ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1413 #else
1414             tcol = cmap_i[rbuf3_i[ct2]];
1415 #endif
1416             if (tcol) {
1417               *mat_j++ = tcol - 1;
1418               *mat_a++ = rbuf4_i[ct2];
1419               ilen++;
1420             }
1421           }
1422         } else { /* allcolumns */
1423           for (l=0; l<max2; l++,ct2++) {
1424             *mat_j++ = rbuf3_i[ct2]; /* same global column index of C */
1425             *mat_a++ = rbuf4_i[ct2];
1426             ilen++;
1427           }
1428         }
1429         imat_ilen[row] = ilen;
1430       }
1431     }
1432   }
1433 
1434   if (!iscsorted) { /* sort column indices of the rows */
1435     for (i=0; i<ismax; i++) {
1436       subc       = (Mat_SeqBAIJ*)submats[i]->data;
1437       imat_j    = subc->j;
1438       imat_i    = subc->i;
1439       imat_a    = subc->a;
1440       imat_ilen = subc->ilen;
1441 
1442       if (allcolumns[i]) continue;
1443       jmax = nrow[i];
1444       for (j=0; j<jmax; j++) {
1445         PetscInt ilen;
1446 
1447         mat_i = imat_i[j];
1448         mat_a = imat_a + mat_i;
1449         mat_j = imat_j + mat_i;
1450         ilen  = imat_ilen[j];
1451         ierr  = PetscSortIntWithScalarArray(ilen,mat_j,mat_a);CHKERRQ(ierr);
1452       }
1453     }
1454   }
1455 
1456   ierr = PetscFree(r_status4);CHKERRQ(ierr);
1457   ierr = PetscFree(r_waits4);CHKERRQ(ierr);
1458   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
1459   ierr = PetscFree(s_waits4);CHKERRQ(ierr);
1460   ierr = PetscFree(s_status4);CHKERRQ(ierr);
1461 
1462   /* Restore the indices */
1463   for (i=0; i<ismax; i++) {
1464     ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
1465     if (!allcolumns[i]) {
1466       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
1467     }
1468   }
1469 
1470   for (i=0; i<ismax; i++) {
1471     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1472     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1473   }
1474 
1475   /* Destroy allocated memory */
1476   if (!ismax) {
1477     ierr = PetscFree(pa);CHKERRQ(ierr);
1478 
1479     ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
1480     for (i=0; i<nrqr; ++i) {
1481       ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
1482     }
1483     for (i=0; i<nrqs; ++i) {
1484       ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
1485     }
1486 
1487     ierr = PetscFree3(sbuf2,req_size,req_source1);CHKERRQ(ierr);
1488     ierr = PetscFree3(req_source2,rbuf2,rbuf3);CHKERRQ(ierr);
1489   }
1490 
1491   ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
1492   ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
1493   ierr = PetscFree5(irow,icol,nrow,ncol,issorted);CHKERRQ(ierr);
1494 
1495   for (i=0; i<nrqs; ++i) {
1496     ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);
1497   }
1498   ierr = PetscFree(rbuf4);CHKERRQ(ierr);
1499 
1500   ierr = PetscFree5(smats,row2proc,cmap,rmap,allcolumns);CHKERRQ(ierr);
1501   PetscFunctionReturn(0);
1502 }
1503 
1504 //------------ endof new -------------
1505 
1506 PetscErrorCode MatGetSubMatrices_MPIBAIJ_local(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,PetscBool *allrows,PetscBool *allcolumns,Mat *submats)
1507 {
1508   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
1509   Mat            A  = c->A;
1510   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*mat;
1511   const PetscInt **irow,**icol,*irow_i;
1512   PetscInt       *nrow,*ncol,*w3,*w4,start;
1513   PetscErrorCode ierr;
1514   PetscMPIInt    size,tag0,tag1,tag2,tag3,*w1,*w2,nrqr,idex,end,proc;
1515   PetscInt       **sbuf1,**sbuf2,rank,i,j,k,l,ct1,ct2,**rbuf1,row;
1516   PetscInt       nrqs,msz,**ptr,*req_size,*ctr,*pa,*tmp,tcol;
1517   PetscInt       **rbuf3,*req_source,**sbuf_aj,**rbuf2,max1,max2;
1518   PetscInt       **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax;
1519   PetscInt       ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
1520   PetscInt       bs     =C->rmap->bs,bs2=c->bs2,*a_j=a->j,*b_j=b->j,*cworkA,*cworkB;
1521   PetscInt       cstart = c->cstartbs,nzA,nzB,*a_i=a->i,*b_i=b->i,imark;
1522   PetscInt       *bmap  = c->garray,ctmp,rstart=c->rstartbs;
1523   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3,*s_waits3;
1524   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status3,*s_status2,*r_status3;
1525   MPI_Comm       comm;
1526   PetscBool      flag;
1527   PetscMPIInt    *onodes1,*olengths1;
1528   PetscBool      ijonly=c->ijonly; /* private flag indicates only matrix data structures are requested */
1529 
1530   /* variables below are used for the matrix numerical values - case of !ijonly */
1531   MPI_Request *r_waits4,*s_waits4;
1532   MPI_Status  *r_status4,*s_status4;
1533   MatScalar   **rbuf4,**sbuf_aa,*vals,*mat_a = NULL,*sbuf_aa_i,*vworkA = NULL,*vworkB = NULL;
1534   MatScalar   *a_a=a->a,*b_a=b->a;
1535 
1536 #if defined(PETSC_USE_CTABLE)
1537   PetscInt   tt;
1538   PetscTable *rmap,*cmap,rmap_i,cmap_i=NULL;
1539 #else
1540   PetscInt **cmap,*cmap_i=NULL,*rtable,*rmap_i,**rmap, Mbs = c->Mbs;
1541 #endif
1542 
1543   PetscFunctionBegin;
1544   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
1545   tag0 = ((PetscObject)C)->tag;
1546   size = c->size;
1547   rank = c->rank;
1548   //if (!rank) printf("MatGetSubMatrices_MPIBAIJ scall %d, bs %d\n",scall,bs);
1549 
1550   /* Get some new tags to keep the communication clean */
1551   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
1552   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
1553   ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
1554 
1555 #if defined(PETSC_USE_CTABLE)
1556   ierr = PetscMalloc4(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol);CHKERRQ(ierr);
1557 #else
1558   ierr = PetscMalloc5(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol,Mbs+1,&rtable);CHKERRQ(ierr);
1559   /* Create hash table for the mapping :row -> proc*/
1560   for (i=0,j=0; i<size; i++) {
1561     jmax = C->rmap->range[i+1]/bs;
1562     for (; j<jmax; j++) rtable[j] = i;
1563   }
1564 #endif
1565 
1566   for (i=0; i<ismax; i++) {
1567     if (allrows[i]) {
1568       irow[i] = NULL;
1569       nrow[i] = C->rmap->N/bs;
1570     } else {
1571       ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
1572       ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
1573     }
1574 
1575     if (allcolumns[i]) {
1576       icol[i] = NULL;
1577       ncol[i] = C->cmap->N/bs;
1578     } else {
1579       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
1580       ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
1581     }
1582   }
1583 
1584   /* evaluate communication - mesg to who,length of mesg,and buffer space
1585      required. Based on this, buffers are allocated, and data copied into them*/
1586   ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);
1587   for (i=0; i<ismax; i++) {
1588     ierr   = PetscMemzero(w4,size*sizeof(PetscInt));CHKERRQ(ierr); /* initialise work vector*/
1589     jmax   = nrow[i];
1590     irow_i = irow[i];
1591     for (j=0; j<jmax; j++) {
1592       if (allrows[i]) row = j;
1593       else row = irow_i[j];
1594 
1595 #if defined(PETSC_USE_CTABLE)
1596       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1597 #else
1598       proc = rtable[row];
1599 #endif
1600       w4[proc]++;
1601     }
1602     for (j=0; j<size; j++) {
1603       if (w4[j]) { w1[j] += w4[j];  w3[j]++;}
1604     }
1605   }
1606 
1607   nrqs     = 0;              /* no of outgoing messages */
1608   msz      = 0;              /* total mesg length for all proc */
1609   w1[rank] = 0;              /* no mesg sent to intself */
1610   w3[rank] = 0;
1611   for (i=0; i<size; i++) {
1612     if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
1613   }
1614   ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
1615   for (i=0,j=0; i<size; i++) {
1616     if (w1[i]) { pa[j] = i; j++; }
1617   }
1618 
1619   /* Each message would have a header = 1 + 2*(no of IS) + data */
1620   for (i=0; i<nrqs; i++) {
1621     j     = pa[i];
1622     w1[j] += w2[j] + 2* w3[j];
1623     msz   += w1[j];
1624   }
1625 
1626   /* Determine the number of messages to expect, their lengths, from from-ids */
1627   ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
1628   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
1629 
1630   /* Now post the Irecvs corresponding to these messages */
1631   ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
1632 
1633   ierr = PetscFree(onodes1);CHKERRQ(ierr);
1634   ierr = PetscFree(olengths1);CHKERRQ(ierr);
1635 
1636   /* Allocate Memory for outgoing messages */
1637   ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
1638   ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
1639   ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
1640   {
1641     PetscInt *iptr = tmp,ict = 0;
1642     for (i=0; i<nrqs; i++) {
1643       j        = pa[i];
1644       iptr    += ict;
1645       sbuf1[j] = iptr;
1646       ict      = w1[j];
1647     }
1648   }
1649 
1650   /* Form the outgoing messages */
1651   /* Initialise the header space */
1652   for (i=0; i<nrqs; i++) {
1653     j           = pa[i];
1654     sbuf1[j][0] = 0;
1655     ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
1656     ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
1657   }
1658 
1659   /* Parse the isrow and copy data into outbuf */
1660   for (i=0; i<ismax; i++) {
1661     ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
1662     irow_i = irow[i];
1663     jmax   = nrow[i];
1664     for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
1665       if (allrows[i]) row = j;
1666       else row = irow_i[j];
1667 
1668 #if defined(PETSC_USE_CTABLE)
1669       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1670 #else
1671       proc = rtable[row];
1672 #endif
1673       if (proc != rank) { /* copy to the outgoing buf*/
1674         ctr[proc]++;
1675         *ptr[proc] = row;
1676         ptr[proc]++;
1677       }
1678     }
1679     /* Update the headers for the current IS */
1680     for (j=0; j<size; j++) { /* Can Optimise this loop too */
1681       if ((ctr_j = ctr[j])) {
1682         sbuf1_j        = sbuf1[j];
1683         k              = ++sbuf1_j[0];
1684         sbuf1_j[2*k]   = ctr_j;
1685         sbuf1_j[2*k-1] = i;
1686       }
1687     }
1688   }
1689 
1690   /*  Now  post the sends */
1691   ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
1692   for (i=0; i<nrqs; ++i) {
1693     j    = pa[i];
1694     ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
1695   }
1696 
1697   /* Post Recieves to capture the buffer size */
1698   ierr     = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
1699   ierr     = PetscMalloc1(nrqs+1,&rbuf2);CHKERRQ(ierr);
1700   rbuf2[0] = tmp + msz;
1701   for (i=1; i<nrqs; ++i) {
1702     rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
1703   }
1704   for (i=0; i<nrqs; ++i) {
1705     j        = pa[i];
1706     ierr     = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag1,comm,r_waits2+i);CHKERRQ(ierr);
1707   }
1708 
1709   /* Send to other procs the buf size they should allocate */
1710 
1711   /* Receive messages*/
1712   ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
1713   ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
1714   ierr = PetscMalloc3(nrqr+1,&sbuf2,nrqr,&req_size,nrqr,&req_source);CHKERRQ(ierr);
1715   {
1716     Mat_SeqBAIJ *sA  = (Mat_SeqBAIJ*)c->A->data,*sB = (Mat_SeqBAIJ*)c->B->data;
1717     PetscInt    *sAi = sA->i,*sBi = sB->i,id,*sbuf2_i;
1718 
1719     for (i=0; i<nrqr; ++i) {
1720       ierr = MPI_Waitany(nrqr,r_waits1,&idex,r_status1+i);CHKERRQ(ierr);
1721 
1722       req_size[idex] = 0;
1723       rbuf1_i        = rbuf1[idex];
1724       start          = 2*rbuf1_i[0] + 1;
1725       ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
1726       ierr           = PetscMalloc1(end,&sbuf2[idex]);CHKERRQ(ierr);
1727       sbuf2_i        = sbuf2[idex];
1728       for (j=start; j<end; j++) {
1729         id              = rbuf1_i[j] - rstart;
1730         ncols           = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
1731         sbuf2_i[j]      = ncols;
1732         req_size[idex] += ncols;
1733       }
1734       req_source[idex] = r_status1[i].MPI_SOURCE;
1735       /* form the header */
1736       sbuf2_i[0] = req_size[idex];
1737       for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
1738       ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source[idex],tag1,comm,s_waits2+i);CHKERRQ(ierr);
1739     }
1740   }
1741   ierr = PetscFree(r_status1);CHKERRQ(ierr);
1742   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
1743 
1744   /*  recv buffer sizes */
1745   /* Receive messages*/
1746   ierr = PetscMalloc1(nrqs+1,&rbuf3);CHKERRQ(ierr);
1747   ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
1748   ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
1749   if (!ijonly) {
1750     ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
1751     ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
1752   }
1753 
1754   for (i=0; i<nrqs; ++i) {
1755     ierr = MPI_Waitany(nrqs,r_waits2,&idex,r_status2+i);CHKERRQ(ierr);
1756     ierr = PetscMalloc1(rbuf2[idex][0],&rbuf3[idex]);CHKERRQ(ierr);
1757     ierr = MPI_Irecv(rbuf3[idex],rbuf2[idex][0],MPIU_INT,r_status2[i].MPI_SOURCE,tag2,comm,r_waits3+idex);CHKERRQ(ierr);
1758     if (!ijonly) {
1759       ierr = PetscMalloc1(rbuf2[idex][0]*bs2,&rbuf4[idex]);CHKERRQ(ierr);
1760       ierr = MPI_Irecv(rbuf4[idex],rbuf2[idex][0]*bs2,MPIU_MATSCALAR,r_status2[i].MPI_SOURCE,tag3,comm,r_waits4+idex);CHKERRQ(ierr);
1761     }
1762   }
1763   ierr = PetscFree(r_status2);CHKERRQ(ierr);
1764   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
1765 
1766   /* Wait on sends1 and sends2 */
1767   ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
1768   ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
1769 
1770   if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
1771   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
1772   ierr = PetscFree(s_status1);CHKERRQ(ierr);
1773   ierr = PetscFree(s_status2);CHKERRQ(ierr);
1774   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
1775   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
1776 
1777   /* Now allocate buffers for a->j, and send them off */
1778   ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
1779   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1780   ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
1781   for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
1782 
1783   ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
1784   {
1785     for (i=0; i<nrqr; i++) {
1786       rbuf1_i   = rbuf1[i];
1787       sbuf_aj_i = sbuf_aj[i];
1788       ct1       = 2*rbuf1_i[0] + 1;
1789       ct2       = 0;
1790       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1791         kmax = rbuf1[i][2*j];
1792         for (k=0; k<kmax; k++,ct1++) {
1793           row    = rbuf1_i[ct1] - rstart;
1794           nzA    = a_i[row+1] - a_i[row];
1795           nzB    = b_i[row+1] - b_i[row];
1796           ncols  = nzA + nzB;
1797           cworkA = a_j + a_i[row];
1798           cworkB = b_j + b_i[row];
1799 
1800           /* load the column indices for this row into cols*/
1801           cols = sbuf_aj_i + ct2;
1802           for (l=0; l<nzB; l++) {
1803             if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
1804             else break;
1805           }
1806           imark = l;
1807           for (l=0; l<nzA; l++)   cols[imark+l] = cstart + cworkA[l];
1808           for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
1809           ct2 += ncols;
1810         }
1811       }
1812       ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source[i],tag2,comm,s_waits3+i);CHKERRQ(ierr);
1813     }
1814   }
1815   ierr = PetscMalloc1(nrqs+1,&r_status3);CHKERRQ(ierr);
1816   ierr = PetscMalloc1(nrqr+1,&s_status3);CHKERRQ(ierr);
1817 
1818   /* Allocate buffers for a->a, and send them off */
1819   if (!ijonly) {
1820     ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
1821     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1822     ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
1823     for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1824 
1825     ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
1826     {
1827       for (i=0; i<nrqr; i++) {
1828         rbuf1_i   = rbuf1[i];
1829         sbuf_aa_i = sbuf_aa[i];
1830         ct1       = 2*rbuf1_i[0]+1;
1831         ct2       = 0;
1832         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1833           kmax = rbuf1_i[2*j];
1834           for (k=0; k<kmax; k++,ct1++) {
1835             row    = rbuf1_i[ct1] - rstart;
1836             nzA    = a_i[row+1] - a_i[row];
1837             nzB    = b_i[row+1] - b_i[row];
1838             ncols  = nzA + nzB;
1839             cworkB = b_j + b_i[row];
1840             vworkA = a_a + a_i[row]*bs2;
1841             vworkB = b_a + b_i[row]*bs2;
1842 
1843             /* load the column values for this row into vals*/
1844             vals = sbuf_aa_i+ct2*bs2;
1845             for (l=0; l<nzB; l++) {
1846               if ((bmap[cworkB[l]]) < cstart) {
1847                 ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1848               } else break;
1849             }
1850             imark = l;
1851             for (l=0; l<nzA; l++) {
1852               ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1853             }
1854             for (l=imark; l<nzB; l++) {
1855               ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1856             }
1857             ct2 += ncols;
1858           }
1859         }
1860         ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_MATSCALAR,req_source[i],tag3,comm,s_waits4+i);CHKERRQ(ierr);
1861       }
1862     }
1863     ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
1864     ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
1865   }
1866   ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
1867   ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1868 
1869   /* Form the matrix */
1870   /* create col map: global col of C -> local col of submatrices */
1871   {
1872     const PetscInt *icol_i;
1873 #if defined(PETSC_USE_CTABLE)
1874     ierr = PetscMalloc1(1+ismax,&cmap);CHKERRQ(ierr);
1875     for (i=0; i<ismax; i++) {
1876       if (!allcolumns[i]) {
1877         ierr   = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
1878         jmax   = ncol[i];
1879         icol_i = icol[i];
1880         cmap_i = cmap[i];
1881         for (j=0; j<jmax; j++) {
1882           ierr = PetscTableAdd(cmap_i,icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1883         }
1884       } else {
1885         cmap[i] = NULL;
1886       }
1887     }
1888 #else
1889     ierr = PetscMalloc1(ismax,&cmap);CHKERRQ(ierr);
1890     for (i=0; i<ismax; i++) {
1891       if (!allcolumns[i]) {
1892         ierr   = PetscCalloc1(c->Nbs,&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           cmap_i[icol_i[j]] = j+1;
1898         }
1899       } else { /* allcolumns[i] */
1900         cmap[i] = NULL;
1901       }
1902     }
1903 #endif
1904   }
1905 
1906   /* Create lens which is required for MatCreate... */
1907   for (i=0,j=0; i<ismax; i++) j += nrow[i];
1908   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ j*sizeof(PetscInt),&lens);CHKERRQ(ierr);
1909   lens[0] = (PetscInt*)(lens + ismax);
1910   ierr    = PetscMemzero(lens[0],j*sizeof(PetscInt));CHKERRQ(ierr);
1911   for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1912 
1913   /* Update lens from local data */
1914   for (i=0; i<ismax; i++) {
1915     jmax = nrow[i];
1916     if (!allcolumns[i]) cmap_i = cmap[i];
1917     irow_i = irow[i];
1918     lens_i = lens[i];
1919     for (j=0; j<jmax; j++) {
1920       if (allrows[i]) row = j;
1921       else row = irow_i[j];
1922 
1923 #if defined(PETSC_USE_CTABLE)
1924       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1925 #else
1926       proc = rtable[row];
1927 #endif
1928       if (proc == rank) {
1929         /* Get indices from matA and then from matB */
1930         row    = row - rstart;
1931         nzA    = a_i[row+1] - a_i[row];
1932         nzB    = b_i[row+1] - b_i[row];
1933         cworkA =  a_j + a_i[row];
1934         cworkB = b_j + b_i[row];
1935         if (!allcolumns[i]) {
1936 #if defined(PETSC_USE_CTABLE)
1937           for (k=0; k<nzA; k++) {
1938             ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1939             if (tt) lens_i[j]++;
1940           }
1941           for (k=0; k<nzB; k++) {
1942             ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1943             if (tt) lens_i[j]++;
1944           }
1945 
1946 #else
1947           for (k=0; k<nzA; k++) {
1948             if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1949           }
1950           for (k=0; k<nzB; k++) {
1951             if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1952           }
1953 #endif
1954         } else { /* allcolumns */
1955           lens_i[j] = nzA + nzB;
1956         }
1957       }
1958     }
1959   }
1960 #if defined(PETSC_USE_CTABLE)
1961   /* Create row map*/
1962   ierr = PetscMalloc1(1+ismax,&rmap);CHKERRQ(ierr);
1963   for (i=0; i<ismax; i++) {
1964     ierr = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1965   }
1966 #else
1967   /* Create row map*/
1968   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ ismax*Mbs*sizeof(PetscInt),&rmap);CHKERRQ(ierr);
1969   rmap[0] = (PetscInt*)(rmap + ismax);
1970   ierr    = PetscMemzero(rmap[0],ismax*Mbs*sizeof(PetscInt));CHKERRQ(ierr);
1971   for (i=1; i<ismax; i++) rmap[i] = rmap[i-1] + Mbs;
1972 #endif
1973   for (i=0; i<ismax; i++) {
1974     irow_i = irow[i];
1975     jmax   = nrow[i];
1976 #if defined(PETSC_USE_CTABLE)
1977     rmap_i = rmap[i];
1978     for (j=0; j<jmax; j++) {
1979       if (allrows[i]) {
1980         ierr = PetscTableAdd(rmap_i,j+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1981       } else {
1982         ierr = PetscTableAdd(rmap_i,irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1983       }
1984     }
1985 #else
1986     rmap_i = rmap[i];
1987     for (j=0; j<jmax; j++) {
1988       if (allrows[i]) rmap_i[j] = j;
1989       else rmap_i[irow_i[j]] = j;
1990     }
1991 #endif
1992   }
1993 
1994   /* Update lens from offproc data */
1995   {
1996     PetscInt    *rbuf2_i,*rbuf3_i,*sbuf1_i;
1997     PetscMPIInt ii;
1998 
1999     for (tmp2=0; tmp2<nrqs; tmp2++) {
2000       ierr    = MPI_Waitany(nrqs,r_waits3,&ii,r_status3+tmp2);CHKERRQ(ierr);
2001       idex    = pa[ii];
2002       sbuf1_i = sbuf1[idex];
2003       jmax    = sbuf1_i[0];
2004       ct1     = 2*jmax+1;
2005       ct2     = 0;
2006       rbuf2_i = rbuf2[ii];
2007       rbuf3_i = rbuf3[ii];
2008       for (j=1; j<=jmax; j++) {
2009         is_no  = sbuf1_i[2*j-1];
2010         max1   = sbuf1_i[2*j];
2011         lens_i = lens[is_no];
2012         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
2013         rmap_i = rmap[is_no];
2014         for (k=0; k<max1; k++,ct1++) {
2015 #if defined(PETSC_USE_CTABLE)
2016           ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
2017           row--;
2018           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2019 #else
2020           row = rmap_i[sbuf1_i[ct1]];  /* the val in the new matrix to be */
2021 #endif
2022           max2 = rbuf2_i[ct1];
2023           for (l=0; l<max2; l++,ct2++) {
2024             if (!allcolumns[is_no]) {
2025 #if defined(PETSC_USE_CTABLE)
2026               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tt);CHKERRQ(ierr);
2027               if (tt) lens_i[row]++;
2028 #else
2029               if (cmap_i[rbuf3_i[ct2]]) lens_i[row]++;
2030 #endif
2031             } else { /* allcolumns */
2032               lens_i[row]++;
2033             }
2034           }
2035         }
2036       }
2037     }
2038   }
2039   ierr = PetscFree(r_status3);CHKERRQ(ierr);
2040   ierr = PetscFree(r_waits3);CHKERRQ(ierr);
2041   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
2042   ierr = PetscFree(s_status3);CHKERRQ(ierr);
2043   ierr = PetscFree(s_waits3);CHKERRQ(ierr);
2044 
2045   /* Create the submatrices */
2046   if (scall == MAT_REUSE_MATRIX) {
2047     if (ijonly) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," MAT_REUSE_MATRIX and ijonly is not supported yet");
2048     /*
2049         Assumes new rows are same length as the old rows, hence bug!
2050     */
2051     for (i=0; i<ismax; i++) {
2052       mat = (Mat_SeqBAIJ*)(submats[i]->data);
2053       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");
2054       ierr = PetscMemcmp(mat->ilen,lens[i],mat->mbs *sizeof(PetscInt),&flag);CHKERRQ(ierr);
2055       if (!flag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Cannot reuse matrix. wrong no of nonzeros");
2056       /* Initial matrix as if empty */
2057       ierr = PetscMemzero(mat->ilen,mat->mbs*sizeof(PetscInt));CHKERRQ(ierr);
2058 
2059       submats[i]->factortype = C->factortype;
2060     }
2061   } else {
2062     PetscInt bs_tmp;
2063     if (ijonly) bs_tmp = 1;
2064     else        bs_tmp = bs;
2065     for (i=0; i<ismax; i++) {
2066       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
2067       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,nrow[i]*bs_tmp,ncol[i]*bs_tmp);CHKERRQ(ierr);
2068       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
2069       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
2070       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
2071     }
2072   }
2073 
2074   /* Assemble the matrices */
2075   /* First assemble the local rows */
2076   {
2077     PetscInt  ilen_row,*imat_ilen,*imat_j,*imat_i;
2078     MatScalar *imat_a = NULL;
2079 
2080     for (i=0; i<ismax; i++) {
2081       mat       = (Mat_SeqBAIJ*)submats[i]->data;
2082       imat_ilen = mat->ilen;
2083       imat_j    = mat->j;
2084       imat_i    = mat->i;
2085       if (!ijonly) imat_a = mat->a;
2086       if (!allcolumns[i]) cmap_i = cmap[i];
2087       rmap_i = rmap[i];
2088       irow_i = irow[i];
2089       jmax   = nrow[i];
2090       for (j=0; j<jmax; j++) {
2091         if (allrows[i]) row = j;
2092         else row = irow_i[j];
2093 
2094 #if defined(PETSC_USE_CTABLE)
2095         ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
2096 #else
2097         proc = rtable[row];
2098 #endif
2099         if (proc == rank) {
2100           row    = row - rstart;
2101           nzA    = a_i[row+1] - a_i[row];
2102           nzB    = b_i[row+1] - b_i[row];
2103           cworkA = a_j + a_i[row];
2104           cworkB = b_j + b_i[row];
2105           if (!ijonly) {
2106             vworkA = a_a + a_i[row]*bs2;
2107             vworkB = b_a + b_i[row]*bs2;
2108           }
2109 #if defined(PETSC_USE_CTABLE)
2110           ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
2111           row--;
2112           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2113 #else
2114           row = rmap_i[row + rstart];
2115 #endif
2116           mat_i = imat_i[row];
2117           if (!ijonly) mat_a = imat_a + mat_i*bs2;
2118           mat_j    = imat_j + mat_i;
2119           ilen_row = imat_ilen[row];
2120 
2121           /* load the column indices for this row into cols*/
2122           if (!allcolumns[i]) {
2123             for (l=0; l<nzB; l++) {
2124               if ((ctmp = bmap[cworkB[l]]) < cstart) {
2125 #if defined(PETSC_USE_CTABLE)
2126                 ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
2127                 if (tcol) {
2128 #else
2129                 if ((tcol = cmap_i[ctmp])) {
2130 #endif
2131                   *mat_j++ = tcol - 1;
2132                   ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2133                   mat_a   += bs2;
2134                   ilen_row++;
2135                 }
2136               } else break;
2137             }
2138             imark = l;
2139             for (l=0; l<nzA; l++) {
2140 #if defined(PETSC_USE_CTABLE)
2141               ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
2142               if (tcol) {
2143 #else
2144               if ((tcol = cmap_i[cstart + cworkA[l]])) {
2145 #endif
2146                 *mat_j++ = tcol - 1;
2147                 if (!ijonly) {
2148                   ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2149                   mat_a += bs2;
2150                 }
2151                 ilen_row++;
2152               }
2153             }
2154             for (l=imark; l<nzB; l++) {
2155 #if defined(PETSC_USE_CTABLE)
2156               ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
2157               if (tcol) {
2158 #else
2159               if ((tcol = cmap_i[bmap[cworkB[l]]])) {
2160 #endif
2161                 *mat_j++ = tcol - 1;
2162                 if (!ijonly) {
2163                   ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2164                   mat_a += bs2;
2165                 }
2166                 ilen_row++;
2167               }
2168             }
2169           } else { /* allcolumns */
2170             for (l=0; l<nzB; l++) {
2171               if ((ctmp = bmap[cworkB[l]]) < cstart) {
2172                 *mat_j++ = ctmp;
2173                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2174                 mat_a   += bs2;
2175                 ilen_row++;
2176               } else break;
2177             }
2178             imark = l;
2179             for (l=0; l<nzA; l++) {
2180               *mat_j++ = cstart+cworkA[l];
2181               if (!ijonly) {
2182                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2183                 mat_a += bs2;
2184               }
2185               ilen_row++;
2186             }
2187             for (l=imark; l<nzB; l++) {
2188               *mat_j++ = bmap[cworkB[l]];
2189               if (!ijonly) {
2190                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2191                 mat_a += bs2;
2192               }
2193               ilen_row++;
2194             }
2195           }
2196           imat_ilen[row] = ilen_row;
2197         }
2198       }
2199     }
2200   }
2201 
2202   /*   Now assemble the off proc rows*/
2203   {
2204     PetscInt    *sbuf1_i,*rbuf2_i,*rbuf3_i,*imat_ilen,ilen;
2205     PetscInt    *imat_j,*imat_i;
2206     MatScalar   *imat_a = NULL,*rbuf4_i = NULL;
2207     PetscMPIInt ii;
2208 
2209     for (tmp2=0; tmp2<nrqs; tmp2++) {
2210       if (ijonly) ii = tmp2;
2211       else {
2212         ierr = MPI_Waitany(nrqs,r_waits4,&ii,r_status4+tmp2);CHKERRQ(ierr);
2213       }
2214       idex    = pa[ii];
2215       sbuf1_i = sbuf1[idex];
2216       jmax    = sbuf1_i[0];
2217       ct1     = 2*jmax + 1;
2218       ct2     = 0;
2219       rbuf2_i = rbuf2[ii];
2220       rbuf3_i = rbuf3[ii];
2221       if (!ijonly) rbuf4_i = rbuf4[ii];
2222       for (j=1; j<=jmax; j++) {
2223         is_no = sbuf1_i[2*j-1];
2224         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
2225         rmap_i    = rmap[is_no];
2226         mat       = (Mat_SeqBAIJ*)submats[is_no]->data;
2227         imat_ilen = mat->ilen;
2228         imat_j    = mat->j;
2229         imat_i    = mat->i;
2230         if (!ijonly) imat_a = mat->a;
2231         max1 = sbuf1_i[2*j];
2232         for (k=0; k<max1; k++,ct1++) {
2233           row = sbuf1_i[ct1];
2234 #if defined(PETSC_USE_CTABLE)
2235           ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
2236           row--;
2237           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
2238 #else
2239           row = rmap_i[row];
2240 #endif
2241           ilen  = imat_ilen[row];
2242           mat_i = imat_i[row];
2243           if (!ijonly) mat_a = imat_a + mat_i*bs2;
2244           mat_j = imat_j + mat_i;
2245           max2  = rbuf2_i[ct1];
2246 
2247           if (!allcolumns[is_no]) {
2248             for (l=0; l<max2; l++,ct2++) {
2249 #if defined(PETSC_USE_CTABLE)
2250               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
2251               if (tcol) {
2252 #else
2253               if ((tcol = cmap_i[rbuf3_i[ct2]])) {
2254 #endif
2255                 *mat_j++ = tcol - 1;
2256                 if (!ijonly) {
2257                   ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2258                   mat_a += bs2;
2259                 }
2260                 ilen++;
2261               }
2262             }
2263           } else { /* allcolumns */
2264             for (l=0; l<max2; l++,ct2++) {
2265               *mat_j++ = rbuf3_i[ct2];
2266               if (!ijonly) {
2267                 ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
2268                 mat_a += bs2;
2269               }
2270               ilen++;
2271             }
2272           }
2273           imat_ilen[row] = ilen;
2274         }
2275       }
2276     }
2277   }
2278   /* sort the rows */
2279   {
2280     PetscInt  ilen_row,*imat_ilen,*imat_j,*imat_i;
2281     MatScalar *imat_a = NULL;
2282     MatScalar *work;
2283 
2284     ierr = PetscMalloc1(bs2,&work);CHKERRQ(ierr);
2285     for (i=0; i<ismax; i++) {
2286       mat       = (Mat_SeqBAIJ*)submats[i]->data;
2287       imat_ilen = mat->ilen;
2288       imat_j    = mat->j;
2289       imat_i    = mat->i;
2290       if (!ijonly) imat_a = mat->a;
2291       if (allcolumns[i]) continue;
2292       jmax   = nrow[i];
2293       for (j=0; j<jmax; j++) {
2294         mat_i = imat_i[j];
2295         if (!ijonly) mat_a = imat_a + mat_i*bs2;
2296         mat_j    = imat_j + mat_i;
2297         ilen_row = imat_ilen[j];
2298         if (!ijonly) {ierr = PetscSortIntWithDataArray(ilen_row,mat_j,mat_a,bs2*sizeof(MatScalar),work);CHKERRQ(ierr);}
2299         else {ierr = PetscSortInt(ilen_row,mat_j);CHKERRQ(ierr);}
2300       }
2301     }
2302     ierr = PetscFree(work);CHKERRQ(ierr);
2303   }
2304   if (!ijonly) {
2305     ierr = PetscFree(r_status4);CHKERRQ(ierr);
2306     ierr = PetscFree(r_waits4);CHKERRQ(ierr);
2307     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
2308     ierr = PetscFree(s_waits4);CHKERRQ(ierr);
2309     ierr = PetscFree(s_status4);CHKERRQ(ierr);
2310   }
2311 
2312   /* Restore the indices */
2313   for (i=0; i<ismax; i++) {
2314     if (!allrows[i]) {
2315       ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
2316     }
2317     if (!allcolumns[i]) {
2318       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
2319     }
2320   }
2321 
2322   /* Destroy allocated memory */
2323 #if defined(PETSC_USE_CTABLE)
2324   ierr = PetscFree4(irow,icol,nrow,ncol);CHKERRQ(ierr);
2325 #else
2326   ierr = PetscFree5(irow,icol,nrow,ncol,rtable);CHKERRQ(ierr);
2327 #endif
2328   ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
2329   ierr = PetscFree(pa);CHKERRQ(ierr);
2330 
2331   ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
2332   ierr = PetscFree(sbuf1);CHKERRQ(ierr);
2333   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
2334   for (i=0; i<nrqr; ++i) {
2335     ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
2336   }
2337   for (i=0; i<nrqs; ++i) {
2338     ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
2339   }
2340   ierr = PetscFree3(sbuf2,req_size,req_source);CHKERRQ(ierr);
2341   ierr = PetscFree(rbuf3);CHKERRQ(ierr);
2342   ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
2343   ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
2344   if (!ijonly) {
2345     for (i=0; i<nrqs; ++i) {ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);}
2346     ierr = PetscFree(rbuf4);CHKERRQ(ierr);
2347     ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
2348     ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
2349   }
2350 
2351 #if defined(PETSC_USE_CTABLE)
2352   for (i=0; i<ismax; i++) {
2353     ierr = PetscTableDestroy((PetscTable*)&rmap[i]);CHKERRQ(ierr);
2354   }
2355 #endif
2356   ierr = PetscFree(rmap);CHKERRQ(ierr);
2357 
2358   for (i=0; i<ismax; i++) {
2359     if (!allcolumns[i]) {
2360 #if defined(PETSC_USE_CTABLE)
2361       ierr = PetscTableDestroy((PetscTable*)&cmap[i]);CHKERRQ(ierr);
2362 #else
2363       ierr = PetscFree(cmap[i]);CHKERRQ(ierr);
2364 #endif
2365     }
2366   }
2367   ierr = PetscFree(cmap);CHKERRQ(ierr);
2368   ierr = PetscFree(lens);CHKERRQ(ierr);
2369 
2370   for (i=0; i<ismax; i++) {
2371     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2372     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2373   }
2374 
2375   c->ijonly = PETSC_FALSE; /* set back to the default */
2376   PetscFunctionReturn(0);
2377 }
2378 
2379