xref: /petsc/src/mat/impls/baij/mpi/baijov.c (revision a98758b74fbc47f3dca87b526141d347301fd5eb)
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,N=C->cmap->N,bs=C->rmap->bs;
524   Mat_SeqBAIJ    *subc;
525   Mat_SubMat     *smat;
526 
527   PetscFunctionBegin;
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   /* Determine the number of stages through which submatrices are done */
535   nmax = 20*1000000 / (c->Nbs * sizeof(PetscInt));
536   if (!nmax) nmax = 1;
537 
538   if (scall == MAT_INITIAL_MATRIX) {
539     nstages_local = ismax/nmax + ((ismax % nmax) ? 1 : 0);
540 
541     /* Make sure every processor loops through the nstages */
542     ierr = MPIU_Allreduce(&nstages_local,&nstages,1,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)C));CHKERRQ(ierr);
543 
544     ierr = PetscMalloc1(ismax+1,submat);CHKERRQ(ierr);
545   } else {
546     subc = (Mat_SeqBAIJ*)((*submat)[0]->data);
547     smat   = subc->submatis1;
548     if (!smat) {
549       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"MatGetSubMatrices(...,MAT_REUSE_MATRIX,...) requires submat");
550     }
551     nstages = smat->nstages;
552   }
553 
554   for (i=0,pos=0; i<nstages; i++) {
555     if (pos+nmax <= ismax) max_no = nmax;
556     else if (pos == ismax) max_no = 0;
557     else                   max_no = ismax-pos;
558 
559     ierr = MatGetSubMatrices_MPIBAIJ_local(C,max_no,isrow_block+pos,iscol_block+pos,scall,*submat+pos);CHKERRQ(ierr);
560     pos += max_no;
561   }
562 
563   if (scall == MAT_INITIAL_MATRIX && ismax) {
564     /* save nstages for reuse */
565     subc = (Mat_SeqBAIJ*)((*submat)[0]->data);
566     smat = subc->submatis1;
567     if (!smat) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"smat does not exit");
568     smat->nstages = nstages;
569   }
570 
571   for (i=0; i<ismax; i++) {
572     ierr = ISDestroy(&isrow_block[i]);CHKERRQ(ierr);
573     ierr = ISDestroy(&iscol_block[i]);CHKERRQ(ierr);
574   }
575   ierr = PetscFree2(isrow_block,iscol_block);CHKERRQ(ierr);
576   PetscFunctionReturn(0);
577 }
578 
579 #if defined(PETSC_USE_CTABLE)
580 PetscErrorCode PetscGetProc(const PetscInt row, const PetscMPIInt size, const PetscInt proc_gnode[], PetscMPIInt *rank)
581 {
582   PetscInt       nGlobalNd = proc_gnode[size];
583   PetscMPIInt    fproc;
584   PetscErrorCode ierr;
585 
586   PetscFunctionBegin;
587   ierr = PetscMPIIntCast((PetscInt)(((float)row * (float)size / (float)nGlobalNd + 0.5)),&fproc);CHKERRQ(ierr);
588   if (fproc > size) fproc = size;
589   while (row < proc_gnode[fproc] || row >= proc_gnode[fproc+1]) {
590     if (row < proc_gnode[fproc]) fproc--;
591     else                         fproc++;
592   }
593   *rank = fproc;
594   PetscFunctionReturn(0);
595 }
596 #endif
597 
598 /* -------------------------------------------------------------------------*/
599 /* This code is used for BAIJ and SBAIJ matrices (unfortunate dependency) */
600 
601 PetscErrorCode MatDestroy_MPIBAIJ_MatGetSubmatrices(Mat C)
602 {
603   PetscErrorCode ierr;
604   Mat_SeqBAIJ    *c = (Mat_SeqBAIJ*)C->data;
605   Mat_SubMat     *submatj = c->submatis1;
606   PetscInt       i;
607 
608   PetscFunctionBegin;
609   if (!submatj->id) { /* delete data that are linked only to submats[id=0] */
610     ierr = PetscFree4(submatj->sbuf1,submatj->ptr,submatj->tmp,submatj->ctr);CHKERRQ(ierr);
611 
612     for (i=0; i<submatj->nrqr; ++i) {
613       ierr = PetscFree(submatj->sbuf2[i]);CHKERRQ(ierr);
614     }
615     ierr = PetscFree3(submatj->sbuf2,submatj->req_size,submatj->req_source1);CHKERRQ(ierr);
616 
617     if (submatj->rbuf1) {
618       ierr = PetscFree(submatj->rbuf1[0]);CHKERRQ(ierr);
619       ierr = PetscFree(submatj->rbuf1);CHKERRQ(ierr);
620     }
621 
622     for (i=0; i<submatj->nrqs; ++i) {
623       ierr = PetscFree(submatj->rbuf3[i]);CHKERRQ(ierr);
624     }
625     ierr = PetscFree3(submatj->req_source2,submatj->rbuf2,submatj->rbuf3);CHKERRQ(ierr);
626     ierr = PetscFree(submatj->pa);CHKERRQ(ierr);
627   }
628 
629 #if defined(PETSC_USE_CTABLE)
630   ierr = PetscTableDestroy((PetscTable*)&submatj->rmap);CHKERRQ(ierr);
631   if (submatj->cmap_loc) {ierr = PetscFree(submatj->cmap_loc);CHKERRQ(ierr);}
632   ierr = PetscFree(submatj->rmap_loc);CHKERRQ(ierr);
633 #else
634   ierr = PetscFree(submatj->rmap);CHKERRQ(ierr);
635 #endif
636 
637   if (!submatj->allcolumns) {
638 #if defined(PETSC_USE_CTABLE)
639     ierr = PetscTableDestroy((PetscTable*)&submatj->cmap);CHKERRQ(ierr);
640 #else
641     ierr = PetscFree(submatj->cmap);CHKERRQ(ierr);
642 #endif
643   }
644   ierr = submatj->destroy(C);CHKERRQ(ierr);
645   ierr = PetscFree(submatj->row2proc);CHKERRQ(ierr);
646 
647   ierr = PetscFree(submatj);CHKERRQ(ierr);
648   PetscFunctionReturn(0);
649 }
650 
651 PetscErrorCode MatGetSubMatrices_MPIBAIJ_local(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,Mat *submats)
652 {
653   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
654   Mat            A  = c->A;
655   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*subc;
656   const PetscInt **icol,**irow;
657   PetscInt       *nrow,*ncol,start;
658   PetscErrorCode ierr;
659   PetscMPIInt    rank,size,tag0,tag2,tag3,tag4,*w1,*w2,*w3,*w4,nrqr;
660   PetscInt       **sbuf1,**sbuf2,*sbuf2_i,i,j,k,l,ct1,ct2,**rbuf1,row,proc=-1;
661   PetscInt       nrqs=0,msz,**ptr=NULL,*req_size=NULL,*ctr=NULL,*pa,*tmp=NULL,tcol;
662   PetscInt       **rbuf3=NULL,*req_source1=NULL,*req_source2,**sbuf_aj,**rbuf2=NULL,max1,max2;
663   PetscInt       **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax;
664 #if defined(PETSC_USE_CTABLE)
665   PetscTable     *cmap,cmap_i=NULL,*rmap,rmap_i;
666 #else
667   PetscInt       **cmap,*cmap_i=NULL,**rmap,*rmap_i;
668 #endif
669   const PetscInt *irow_i,*icol_i;
670   PetscInt       ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
671   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3;
672   MPI_Request    *r_waits4,*s_waits3,*s_waits4;
673   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status3,*s_status2;
674   MPI_Status     *r_status3,*r_status4,*s_status4;
675   MPI_Comm       comm;
676   PetscScalar    **rbuf4,*rbuf4_i=NULL,**sbuf_aa,*vals,*mat_a=NULL,*imat_a,*sbuf_aa_i;
677   PetscMPIInt    *onodes1,*olengths1,end;
678   PetscInt       **row2proc,*row2proc_i,*imat_ilen,*imat_j,*imat_i;
679   Mat_SubMat     **smats,*smat_i;
680   PetscBool      *issorted,colflag,iscsorted=PETSC_TRUE;
681   PetscInt       *sbuf1_i,*rbuf2_i,*rbuf3_i,ilen;
682   PetscInt       bs=C->rmap->bs,bs2=c->bs2,rstart = c->rstartbs;
683   PetscBool      ijonly=c->ijonly; /* private flag indicates only matrix data structures are requested */
684   PetscInt       nzA,nzB,*a_i=a->i,*b_i=b->i,*a_j = a->j,*b_j = b->j,ctmp,imark,*cworkA,*cworkB;
685   PetscScalar    *vworkA=NULL,*vworkB=NULL,*a_a = a->a,*b_a = b->a;
686   PetscInt       cstart = c->cstartbs,*bmap = c->garray;
687   PetscBool      *allrows,*allcolumns;
688 
689   PetscFunctionBegin;
690   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
691   size = c->size;
692   rank = c->rank;
693 
694   ierr = PetscMalloc6(ismax,&smats,ismax,&row2proc,ismax,&cmap,ismax,&rmap,ismax,&allcolumns,ismax,&allrows);CHKERRQ(ierr);
695   ierr = PetscMalloc5(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol,ismax,&issorted);CHKERRQ(ierr);
696 
697   for (i=0; i<ismax; i++) {
698     ierr = ISSorted(iscol[i],&issorted[i]);CHKERRQ(ierr);
699     if (!issorted[i]) iscsorted = issorted[i]; /* columns are not sorted! */
700     ierr = ISSorted(isrow[i],&issorted[i]);CHKERRQ(ierr);
701 
702     /* Check for special case: allcolumns */
703     ierr = ISIdentity(iscol[i],&colflag);CHKERRQ(ierr);
704     ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
705 
706     if (colflag && ncol[i] == c->Nbs) {
707       allcolumns[i] = PETSC_TRUE;
708       icol[i]       = NULL;
709     } else {
710       allcolumns[i] = PETSC_FALSE;
711       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
712     }
713 
714     /* Check for special case: allrows */
715     ierr = ISIdentity(isrow[i],&colflag);CHKERRQ(ierr);
716     ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
717     if (colflag && nrow[i] == c->Mbs) {
718       allrows[i] = PETSC_TRUE;
719       irow[i]    = NULL;
720     } else {
721       allrows[i] = PETSC_FALSE;
722       ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
723     }
724   }
725 
726   if (scall == MAT_REUSE_MATRIX) {
727     /* Assumes new rows are same length as the old rows */
728     for (i=0; i<ismax; i++) {
729       subc = (Mat_SeqBAIJ*)(submats[i]->data);
730       if (subc->mbs != nrow[i] || subc->nbs != ncol[i]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
731 
732       /* Initial matrix as if empty */
733       ierr = PetscMemzero(subc->ilen,subc->mbs*sizeof(PetscInt));CHKERRQ(ierr);
734 
735       /* Initial matrix as if empty */
736       submats[i]->factortype = C->factortype;
737 
738       smat_i   = subc->submatis1;
739       smats[i] = smat_i;
740 
741       nrqs        = smat_i->nrqs;
742       nrqr        = smat_i->nrqr;
743       rbuf1       = smat_i->rbuf1;
744       rbuf2       = smat_i->rbuf2;
745       rbuf3       = smat_i->rbuf3;
746       req_source2 = smat_i->req_source2;
747 
748       sbuf1     = smat_i->sbuf1;
749       sbuf2     = smat_i->sbuf2;
750       ptr       = smat_i->ptr;
751       tmp       = smat_i->tmp;
752       ctr       = smat_i->ctr;
753 
754       pa          = smat_i->pa;
755       req_size    = smat_i->req_size;
756       req_source1 = smat_i->req_source1;
757 
758       allcolumns[i] = smat_i->allcolumns;
759       allrows[i]    = smat_i->allrows;
760       row2proc[i]   = smat_i->row2proc;
761       rmap[i]       = smat_i->rmap;
762       cmap[i]       = smat_i->cmap;
763     }
764   } else { /* scall == MAT_INITIAL_MATRIX */
765     /* Get some new tags to keep the communication clean */
766     ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
767     ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
768 
769     /* evaluate communication - mesg to who, length of mesg, and buffer space
770      required. Based on this, buffers are allocated, and data copied into them*/
771     ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);   /* mesg size, initialize work vectors */
772 
773     for (i=0; i<ismax; i++) {
774       jmax   = nrow[i];
775       irow_i = irow[i];
776 
777       ierr   = PetscMalloc1(jmax,&row2proc_i);CHKERRQ(ierr);
778       row2proc[i] = row2proc_i;
779 
780       if (issorted[i]) proc = 0;
781       for (j=0; j<jmax; j++) {
782         if (!issorted[i]) proc = 0;
783         if (allrows[i]) row = j;
784         else row = irow_i[j];
785 
786         while (row >= c->rangebs[proc+1]) proc++;
787         w4[proc]++;
788         row2proc_i[j] = proc; /* map row index to proc */
789       }
790       for (j=0; j<size; j++) {
791         if (w4[j]) { w1[j] += w4[j];  w3[j]++; w4[j] = 0;}
792       }
793     }
794 
795     nrqs     = 0;              /* no of outgoing messages */
796     msz      = 0;              /* total mesg length (for all procs) */
797     w1[rank] = 0;              /* no mesg sent to self */
798     w3[rank] = 0;
799     for (i=0; i<size; i++) {
800       if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
801     }
802     ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
803     for (i=0,j=0; i<size; i++) {
804       if (w1[i]) { pa[j] = i; j++; }
805     }
806 
807     /* Each message would have a header = 1 + 2*(no of IS) + data */
808     for (i=0; i<nrqs; i++) {
809       j      = pa[i];
810       w1[j] += w2[j] + 2* w3[j];
811       msz   += w1[j];
812     }
813     ierr = PetscInfo2(0,"Number of outgoing messages %D Total message length %D\n",nrqs,msz);CHKERRQ(ierr);
814 
815     /* Determine the number of messages to expect, their lengths, from from-ids */
816     ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
817     ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
818 
819     /* Now post the Irecvs corresponding to these messages */
820     tag0 = ((PetscObject)C)->tag;
821     ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
822 
823     ierr = PetscFree(onodes1);CHKERRQ(ierr);
824     ierr = PetscFree(olengths1);CHKERRQ(ierr);
825 
826     /* Allocate Memory for outgoing messages */
827     ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
828     ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
829     ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
830 
831     {
832       PetscInt *iptr = tmp;
833       k    = 0;
834       for (i=0; i<nrqs; i++) {
835         j        = pa[i];
836         iptr    += k;
837         sbuf1[j] = iptr;
838         k        = w1[j];
839       }
840     }
841 
842     /* Form the outgoing messages. Initialize the header space */
843     for (i=0; i<nrqs; i++) {
844       j           = pa[i];
845       sbuf1[j][0] = 0;
846       ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
847       ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
848     }
849 
850     /* Parse the isrow and copy data into outbuf */
851     for (i=0; i<ismax; i++) {
852       row2proc_i = row2proc[i];
853       ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
854       irow_i = irow[i];
855       jmax   = nrow[i];
856       for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
857         proc = row2proc_i[j];
858         if (allrows[i]) row = j;
859         else row = irow_i[j];
860 
861         if (proc != rank) { /* copy to the outgoing buf*/
862           ctr[proc]++;
863           *ptr[proc] = row;
864           ptr[proc]++;
865         }
866       }
867       /* Update the headers for the current IS */
868       for (j=0; j<size; j++) { /* Can Optimise this loop too */
869         if ((ctr_j = ctr[j])) {
870           sbuf1_j        = sbuf1[j];
871           k              = ++sbuf1_j[0];
872           sbuf1_j[2*k]   = ctr_j;
873           sbuf1_j[2*k-1] = i;
874         }
875       }
876     }
877 
878     /*  Now  post the sends */
879     ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
880     for (i=0; i<nrqs; ++i) {
881       j    = pa[i];
882       ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
883     }
884 
885     /* Post Receives to capture the buffer size */
886     ierr = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
887     ierr = PetscMalloc3(nrqs+1,&req_source2,nrqs+1,&rbuf2,nrqs+1,&rbuf3);CHKERRQ(ierr);
888     rbuf2[0] = tmp + msz;
889     for (i=1; i<nrqs; ++i) {
890       rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
891     }
892     for (i=0; i<nrqs; ++i) {
893       j    = pa[i];
894       ierr = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag2,comm,r_waits2+i);CHKERRQ(ierr);
895     }
896 
897     /* Send to other procs the buf size they should allocate */
898     /* Receive messages*/
899     ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
900     ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
901     ierr = PetscMalloc3(nrqr,&sbuf2,nrqr,&req_size,nrqr,&req_source1);CHKERRQ(ierr);
902 
903     ierr = MPI_Waitall(nrqr,r_waits1,r_status1);CHKERRQ(ierr);
904     for (i=0; i<nrqr; ++i) {
905       req_size[i] = 0;
906       rbuf1_i        = rbuf1[i];
907       start          = 2*rbuf1_i[0] + 1;
908       ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
909       ierr           = PetscMalloc1(end+1,&sbuf2[i]);CHKERRQ(ierr);
910       sbuf2_i        = sbuf2[i];
911       for (j=start; j<end; j++) {
912         row             = rbuf1_i[j] - rstart;
913         ncols           = a_i[row+1] - a_i[row] + b_i[row+1] - b_i[row];
914         sbuf2_i[j]      = ncols;
915         req_size[i] += ncols;
916       }
917       req_source1[i] = r_status1[i].MPI_SOURCE;
918       /* form the header */
919       sbuf2_i[0] = req_size[i];
920       for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
921 
922       ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source1[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
923     }
924 
925     ierr = PetscFree(r_status1);CHKERRQ(ierr);
926     ierr = PetscFree(r_waits1);CHKERRQ(ierr);
927     ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
928 
929     /* Receive messages*/
930     ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
931     ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
932 
933     ierr = MPI_Waitall(nrqs,r_waits2,r_status2);CHKERRQ(ierr);
934     for (i=0; i<nrqs; ++i) {
935       ierr = PetscMalloc1(rbuf2[i][0]+1,&rbuf3[i]);CHKERRQ(ierr);
936       req_source2[i] = r_status2[i].MPI_SOURCE;
937       ierr = MPI_Irecv(rbuf3[i],rbuf2[i][0],MPIU_INT,req_source2[i],tag3,comm,r_waits3+i);CHKERRQ(ierr);
938     }
939     ierr = PetscFree(r_status2);CHKERRQ(ierr);
940     ierr = PetscFree(r_waits2);CHKERRQ(ierr);
941 
942     /* Wait on sends1 and sends2 */
943     ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
944     ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
945 
946     if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
947     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
948     ierr = PetscFree(s_status1);CHKERRQ(ierr);
949     ierr = PetscFree(s_status2);CHKERRQ(ierr);
950     ierr = PetscFree(s_waits1);CHKERRQ(ierr);
951     ierr = PetscFree(s_waits2);CHKERRQ(ierr);
952 
953     /* Now allocate sending buffers for a->j, and send them off */
954     ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
955     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
956     ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
957     for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
958 
959     ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
960     {
961 
962       for (i=0; i<nrqr; i++) {
963         rbuf1_i   = rbuf1[i];
964         sbuf_aj_i = sbuf_aj[i];
965         ct1       = 2*rbuf1_i[0] + 1;
966         ct2       = 0;
967         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
968           kmax = rbuf1[i][2*j];
969           for (k=0; k<kmax; k++,ct1++) {
970             row    = rbuf1_i[ct1] - rstart;
971             nzA    = a_i[row+1] - a_i[row]; nzB = b_i[row+1] - b_i[row];
972             ncols  = nzA + nzB;
973             cworkA = a_j + a_i[row]; cworkB = b_j + b_i[row];
974 
975             /* load the column indices for this row into cols */
976             cols = sbuf_aj_i + ct2;
977             for (l=0; l<nzB; l++) {
978               if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
979               else break;
980             }
981             imark = l;
982             for (l=0; l<nzA; l++) {cols[imark+l] = cstart + cworkA[l];}
983             for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
984             ct2 += ncols;
985           }
986         }
987         ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source1[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
988       }
989     }
990     ierr = PetscMalloc2(nrqs+1,&r_status3,nrqr+1,&s_status3);CHKERRQ(ierr);
991 
992     /* create col map: global col of C -> local col of submatrices */
993 #if defined(PETSC_USE_CTABLE)
994     for (i=0; i<ismax; i++) {
995       if (!allcolumns[i]) {
996         ierr = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
997 
998         jmax   = ncol[i];
999         icol_i = icol[i];
1000         cmap_i = cmap[i];
1001         for (j=0; j<jmax; j++) {
1002           ierr = PetscTableAdd(cmap[i],icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1003         }
1004       } else cmap[i] = NULL;
1005     }
1006 #else
1007     for (i=0; i<ismax; i++) {
1008       if (!allcolumns[i]) {
1009         ierr   = PetscCalloc1(c->Nbs,&cmap[i]);CHKERRQ(ierr);
1010         jmax   = ncol[i];
1011         icol_i = icol[i];
1012         cmap_i = cmap[i];
1013         for (j=0; j<jmax; j++) cmap_i[icol_i[j]] = j+1;
1014       } else cmap[i] = NULL;
1015     }
1016 #endif
1017 
1018     /* Create lens which is required for MatCreate... */
1019     for (i=0,j=0; i<ismax; i++) j += nrow[i];
1020     ierr = PetscMalloc1(ismax,&lens);CHKERRQ(ierr);
1021 
1022     if (ismax) {
1023       ierr = PetscCalloc1(j,&lens[0]);CHKERRQ(ierr);
1024     }
1025     for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1026 
1027     /* Update lens from local data */
1028     for (i=0; i<ismax; i++) {
1029       row2proc_i = row2proc[i];
1030       jmax = nrow[i];
1031       if (!allcolumns[i]) cmap_i = cmap[i];
1032       irow_i = irow[i];
1033       lens_i = lens[i];
1034       for (j=0; j<jmax; j++) {
1035         if (allrows[i]) row = j;
1036         else row = irow_i[j]; /* global blocked row of C */
1037 
1038         proc = row2proc_i[j];
1039         if (proc == rank) {
1040           /* Get indices from matA and then from matB */
1041 #if defined(PETSC_USE_CTABLE)
1042           PetscInt   tt;
1043 #endif
1044           row    = row - rstart;
1045           nzA    = a_i[row+1] - a_i[row];
1046           nzB    = b_i[row+1] - b_i[row];
1047           cworkA =  a_j + a_i[row];
1048           cworkB = b_j + b_i[row];
1049 
1050           if (!allcolumns[i]) {
1051 #if defined(PETSC_USE_CTABLE)
1052             for (k=0; k<nzA; k++) {
1053               ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1054               if (tt) lens_i[j]++;
1055             }
1056             for (k=0; k<nzB; k++) {
1057               ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1058               if (tt) lens_i[j]++;
1059             }
1060 
1061 #else
1062             for (k=0; k<nzA; k++) {
1063               if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1064             }
1065             for (k=0; k<nzB; k++) {
1066               if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1067             }
1068 #endif
1069           } else { /* allcolumns */
1070             lens_i[j] = nzA + nzB;
1071           }
1072         }
1073       }
1074     }
1075 
1076     /* Create row map: global row of C -> local row of submatrices */
1077     for (i=0; i<ismax; i++) {
1078       if (!allrows[i]) {
1079 #if defined(PETSC_USE_CTABLE)
1080         ierr   = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1081         irow_i = irow[i];
1082         jmax   = nrow[i];
1083         for (j=0; j<jmax; j++) {
1084           if (allrows[i]) {
1085             ierr = PetscTableAdd(rmap[i],j+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1086           } else {
1087             ierr = PetscTableAdd(rmap[i],irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1088           }
1089         }
1090 #else
1091         ierr   = PetscCalloc1(c->Mbs,&rmap[i]);CHKERRQ(ierr);
1092         rmap_i = rmap[i];
1093         irow_i = irow[i];
1094         jmax   = nrow[i];
1095         for (j=0; j<jmax; j++) {
1096           if (allrows[i]) rmap_i[j] = j;
1097           else rmap_i[irow_i[j]] = j;
1098         }
1099 #endif
1100       } else rmap[i] = NULL;
1101     }
1102 
1103     /* Update lens from offproc data */
1104     {
1105       PetscInt *rbuf2_i,*rbuf3_i,*sbuf1_i;
1106 
1107       ierr    = MPI_Waitall(nrqs,r_waits3,r_status3);CHKERRQ(ierr);
1108       for (tmp2=0; tmp2<nrqs; tmp2++) {
1109         sbuf1_i = sbuf1[pa[tmp2]];
1110         jmax    = sbuf1_i[0];
1111         ct1     = 2*jmax+1;
1112         ct2     = 0;
1113         rbuf2_i = rbuf2[tmp2];
1114         rbuf3_i = rbuf3[tmp2];
1115         for (j=1; j<=jmax; j++) {
1116           is_no  = sbuf1_i[2*j-1];
1117           max1   = sbuf1_i[2*j];
1118           lens_i = lens[is_no];
1119           if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1120           rmap_i = rmap[is_no];
1121           for (k=0; k<max1; k++,ct1++) {
1122             if (allrows[is_no]) {
1123               row = sbuf1_i[ct1];
1124             } else {
1125 #if defined(PETSC_USE_CTABLE)
1126               ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
1127               row--;
1128               if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1129 #else
1130               row = rmap_i[sbuf1_i[ct1]]; /* the val in the new matrix to be */
1131 #endif
1132             }
1133             max2 = rbuf2_i[ct1];
1134             for (l=0; l<max2; l++,ct2++) {
1135               if (!allcolumns[is_no]) {
1136 #if defined(PETSC_USE_CTABLE)
1137                 ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1138 #else
1139                 tcol = cmap_i[rbuf3_i[ct2]];
1140 #endif
1141                 if (tcol) lens_i[row]++;
1142               } else { /* allcolumns */
1143                 lens_i[row]++; /* lens_i[row] += max2 ? */
1144               }
1145             }
1146           }
1147         }
1148       }
1149     }
1150     ierr = PetscFree(r_waits3);CHKERRQ(ierr);
1151     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
1152     ierr = PetscFree2(r_status3,s_status3);CHKERRQ(ierr);
1153     ierr = PetscFree(s_waits3);CHKERRQ(ierr);
1154 
1155     /* Create the submatrices */
1156     for (i=0; i<ismax; i++) {
1157       PetscInt bs_tmp;
1158       if (ijonly) bs_tmp = 1;
1159       else        bs_tmp = bs;
1160 
1161       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
1162       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
1163 
1164       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
1165       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
1166       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
1167 
1168       /* create struct Mat_SubMat and attached it to submat */
1169       ierr = PetscNew(&smat_i);CHKERRQ(ierr);
1170       subc = (Mat_SeqBAIJ*)submats[i]->data;
1171       subc->submatis1 = smat_i;
1172       smats[i]        = smat_i;
1173 
1174       smat_i->destroy          = submats[i]->ops->destroy;
1175       submats[i]->ops->destroy = MatDestroy_MPIBAIJ_MatGetSubmatrices;
1176       submats[i]->factortype   = C->factortype;
1177 
1178       smat_i->id          = i;
1179       smat_i->nrqs        = nrqs;
1180       smat_i->nrqr        = nrqr;
1181       smat_i->rbuf1       = rbuf1;
1182       smat_i->rbuf2       = rbuf2;
1183       smat_i->rbuf3       = rbuf3;
1184       smat_i->sbuf2       = sbuf2;
1185       smat_i->req_source2 = req_source2;
1186 
1187       smat_i->sbuf1       = sbuf1;
1188       smat_i->ptr         = ptr;
1189       smat_i->tmp         = tmp;
1190       smat_i->ctr         = ctr;
1191 
1192       smat_i->pa           = pa;
1193       smat_i->req_size     = req_size;
1194       smat_i->req_source1  = req_source1;
1195 
1196       smat_i->allcolumns  = allcolumns[i];
1197       smat_i->allrows     = allrows[i];
1198       smat_i->singleis    = PETSC_FALSE;
1199       smat_i->row2proc    = row2proc[i];
1200       smat_i->rmap        = rmap[i];
1201       smat_i->cmap        = cmap[i];
1202     }
1203 
1204     if (ismax) {ierr = PetscFree(lens[0]);CHKERRQ(ierr);}
1205     ierr = PetscFree(lens);CHKERRQ(ierr);
1206     ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
1207     ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
1208 
1209   } /* endof scall == MAT_INITIAL_MATRIX */
1210 
1211   /* Post recv matrix values */
1212   if (!ijonly) {
1213     ierr = PetscObjectGetNewTag((PetscObject)C,&tag4);CHKERRQ(ierr);
1214     ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
1215     ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
1216     ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
1217     ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
1218     for (i=0; i<nrqs; ++i) {
1219       ierr = PetscMalloc1(rbuf2[i][0]*bs2,&rbuf4[i]);CHKERRQ(ierr);
1220       ierr = MPI_Irecv(rbuf4[i],rbuf2[i][0]*bs2,MPIU_SCALAR,req_source2[i],tag4,comm,r_waits4+i);CHKERRQ(ierr);
1221     }
1222 
1223     /* Allocate sending buffers for a->a, and send them off */
1224     ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
1225     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
1226 
1227     ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
1228     for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
1229 
1230     ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
1231 
1232     for (i=0; i<nrqr; i++) {
1233       rbuf1_i   = rbuf1[i];
1234       sbuf_aa_i = sbuf_aa[i];
1235       ct1       = 2*rbuf1_i[0]+1;
1236       ct2       = 0;
1237       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
1238         kmax = rbuf1_i[2*j];
1239         for (k=0; k<kmax; k++,ct1++) {
1240           row    = rbuf1_i[ct1] - rstart;
1241           nzA    = a_i[row+1] - a_i[row];
1242           nzB    = b_i[row+1] - b_i[row];
1243           ncols  = nzA + nzB;
1244           cworkB = b_j + b_i[row];
1245           vworkA = a_a + a_i[row]*bs2;
1246           vworkB = b_a + b_i[row]*bs2;
1247 
1248           /* load the column values for this row into vals*/
1249           vals = sbuf_aa_i+ct2*bs2;
1250           for (l=0; l<nzB; l++) {
1251             if ((bmap[cworkB[l]]) < cstart) {
1252               ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1253             } else break;
1254           }
1255           imark = l;
1256           for (l=0; l<nzA; l++) {
1257             ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1258           }
1259           for (l=imark; l<nzB; l++) {
1260             ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1261           }
1262 
1263           ct2 += ncols;
1264         }
1265       }
1266       ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_SCALAR,req_source1[i],tag4,comm,s_waits4+i);CHKERRQ(ierr);
1267     }
1268   }
1269 
1270   if (!ismax) {
1271     ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
1272     ierr = PetscFree(rbuf1);CHKERRQ(ierr);
1273   }
1274 
1275   /* Assemble the matrices */
1276   /* First assemble the local rows */
1277   for (i=0; i<ismax; i++) {
1278     row2proc_i = row2proc[i];
1279     subc      = (Mat_SeqBAIJ*)submats[i]->data;
1280     imat_ilen = subc->ilen;
1281     imat_j    = subc->j;
1282     imat_i    = subc->i;
1283     imat_a    = subc->a;
1284 
1285     if (!allcolumns[i]) cmap_i = cmap[i];
1286     rmap_i = rmap[i];
1287     irow_i = irow[i];
1288     jmax   = nrow[i];
1289     for (j=0; j<jmax; j++) {
1290       if (allrows[i]) row = j;
1291       else row  = irow_i[j];
1292       proc = row2proc_i[j];
1293 
1294       if (proc == rank) {
1295 
1296         row    = row - rstart;
1297         nzA    = a_i[row+1] - a_i[row];
1298         nzB    = b_i[row+1] - b_i[row];
1299         cworkA = a_j + a_i[row];
1300         cworkB = b_j + b_i[row];
1301         if (!ijonly) {
1302           vworkA = a_a + a_i[row]*bs2;
1303           vworkB = b_a + b_i[row]*bs2;
1304         }
1305 
1306         if (allrows[i]) {
1307           row = row+rstart;
1308         } else {
1309 #if defined(PETSC_USE_CTABLE)
1310           ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
1311           row--;
1312 
1313           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1314 #else
1315           row = rmap_i[row + rstart];
1316 #endif
1317         }
1318         mat_i = imat_i[row];
1319         if (!ijonly) mat_a = imat_a + mat_i*bs2;
1320         mat_j    = imat_j + mat_i;
1321         ilen = imat_ilen[row];
1322 
1323         /* load the column indices for this row into cols*/
1324         if (!allcolumns[i]) {
1325           for (l=0; l<nzB; l++) {
1326             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1327 #if defined(PETSC_USE_CTABLE)
1328               ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
1329               if (tcol) {
1330 #else
1331               if ((tcol = cmap_i[ctmp])) {
1332 #endif
1333                 *mat_j++ = tcol - 1;
1334                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1335                 mat_a   += bs2;
1336                 ilen++;
1337               }
1338             } else break;
1339           }
1340           imark = l;
1341           for (l=0; l<nzA; l++) {
1342 #if defined(PETSC_USE_CTABLE)
1343             ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
1344             if (tcol) {
1345 #else
1346             if ((tcol = cmap_i[cstart + cworkA[l]])) {
1347 #endif
1348               *mat_j++ = tcol - 1;
1349               if (!ijonly) {
1350                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1351                 mat_a += bs2;
1352               }
1353               ilen++;
1354             }
1355           }
1356           for (l=imark; l<nzB; l++) {
1357 #if defined(PETSC_USE_CTABLE)
1358             ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
1359             if (tcol) {
1360 #else
1361             if ((tcol = cmap_i[bmap[cworkB[l]]])) {
1362 #endif
1363               *mat_j++ = tcol - 1;
1364               if (!ijonly) {
1365                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1366                 mat_a += bs2;
1367               }
1368               ilen++;
1369             }
1370           }
1371         } else { /* allcolumns */
1372           for (l=0; l<nzB; l++) {
1373             if ((ctmp = bmap[cworkB[l]]) < cstart) {
1374               *mat_j++ = ctmp;
1375               ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1376               mat_a   += bs2;
1377               ilen++;
1378             } else break;
1379           }
1380           imark = l;
1381           for (l=0; l<nzA; l++) {
1382             *mat_j++ = cstart+cworkA[l];
1383             if (!ijonly) {
1384               ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1385               mat_a += bs2;
1386             }
1387             ilen++;
1388           }
1389           for (l=imark; l<nzB; l++) {
1390             *mat_j++ = bmap[cworkB[l]];
1391             if (!ijonly) {
1392               ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1393               mat_a += bs2;
1394             }
1395             ilen++;
1396           }
1397         }
1398         imat_ilen[row] = ilen;
1399       }
1400     }
1401   }
1402 
1403   /* Now assemble the off proc rows */
1404   if (!ijonly) {
1405     ierr = MPI_Waitall(nrqs,r_waits4,r_status4);CHKERRQ(ierr);
1406   }
1407   for (tmp2=0; tmp2<nrqs; tmp2++) {
1408     sbuf1_i = sbuf1[pa[tmp2]];
1409     jmax    = sbuf1_i[0];
1410     ct1     = 2*jmax + 1;
1411     ct2     = 0;
1412     rbuf2_i = rbuf2[tmp2];
1413     rbuf3_i = rbuf3[tmp2];
1414     if (!ijonly) rbuf4_i = rbuf4[tmp2];
1415     for (j=1; j<=jmax; j++) {
1416       is_no     = sbuf1_i[2*j-1];
1417       rmap_i    = rmap[is_no];
1418       if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1419       subc      = (Mat_SeqBAIJ*)submats[is_no]->data;
1420       imat_ilen = subc->ilen;
1421       imat_j    = subc->j;
1422       imat_i    = subc->i;
1423       if (!ijonly) imat_a    = subc->a;
1424       max1      = sbuf1_i[2*j];
1425       for (k=0; k<max1; k++,ct1++) { /* for each recved block row */
1426         row = sbuf1_i[ct1];
1427 
1428         if (allrows[is_no]) {
1429           row = sbuf1_i[ct1];
1430         } else {
1431 #if defined(PETSC_USE_CTABLE)
1432           ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
1433           row--;
1434           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1435 #else
1436           row = rmap_i[row];
1437 #endif
1438         }
1439         ilen  = imat_ilen[row];
1440         mat_i = imat_i[row];
1441         if (!ijonly) mat_a = imat_a + mat_i*bs2;
1442         mat_j = imat_j + mat_i;
1443         max2  = rbuf2_i[ct1];
1444         if (!allcolumns[is_no]) {
1445           for (l=0; l<max2; l++,ct2++) {
1446 #if defined(PETSC_USE_CTABLE)
1447             ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1448 #else
1449             tcol = cmap_i[rbuf3_i[ct2]];
1450 #endif
1451             if (tcol) {
1452               *mat_j++ = tcol - 1;
1453               if (!ijonly) {
1454                 ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1455                 mat_a += bs2;
1456               }
1457               ilen++;
1458             }
1459           }
1460         } else { /* allcolumns */
1461           for (l=0; l<max2; l++,ct2++) {
1462             *mat_j++ = rbuf3_i[ct2]; /* same global column index of C */
1463             if (!ijonly) {
1464               ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1465               mat_a += bs2;
1466             }
1467             ilen++;
1468           }
1469         }
1470         imat_ilen[row] = ilen;
1471       }
1472     }
1473   }
1474 
1475   if (!iscsorted) { /* sort column indices of the rows */
1476     MatScalar *work;
1477 
1478     ierr = PetscMalloc1(bs2,&work);CHKERRQ(ierr);
1479     for (i=0; i<ismax; i++) {
1480       subc      = (Mat_SeqBAIJ*)submats[i]->data;
1481       imat_ilen = subc->ilen;
1482       imat_j    = subc->j;
1483       imat_i    = subc->i;
1484       if (!ijonly) imat_a = subc->a;
1485       if (allcolumns[i]) continue;
1486 
1487       jmax = nrow[i];
1488       for (j=0; j<jmax; j++) {
1489         mat_i = imat_i[j];
1490         mat_j = imat_j + mat_i;
1491         ilen  = imat_ilen[j];
1492         if (ijonly) {
1493           ierr = PetscSortInt(ilen,mat_j);CHKERRQ(ierr);
1494         } else {
1495           mat_a = imat_a + mat_i*bs2;
1496           ierr = PetscSortIntWithDataArray(ilen,mat_j,mat_a,bs2*sizeof(MatScalar),work);CHKERRQ(ierr);
1497         }
1498       }
1499     }
1500     ierr = PetscFree(work);CHKERRQ(ierr);
1501   }
1502 
1503   if (!ijonly) {
1504     ierr = PetscFree(r_status4);CHKERRQ(ierr);
1505     ierr = PetscFree(r_waits4);CHKERRQ(ierr);
1506     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
1507     ierr = PetscFree(s_waits4);CHKERRQ(ierr);
1508     ierr = PetscFree(s_status4);CHKERRQ(ierr);
1509   }
1510 
1511   /* Restore the indices */
1512   for (i=0; i<ismax; i++) {
1513     if (!allrows[i]) {
1514       ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
1515     }
1516     if (!allcolumns[i]) {
1517       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
1518     }
1519   }
1520 
1521   for (i=0; i<ismax; i++) {
1522     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1523     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1524   }
1525 
1526   /* Destroy allocated memory */
1527   if (!ismax) {
1528     ierr = PetscFree(pa);CHKERRQ(ierr);
1529     ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
1530     for (i=0; i<nrqr; ++i) {
1531       ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
1532     }
1533     for (i=0; i<nrqs; ++i) {
1534       ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
1535     }
1536 
1537     ierr = PetscFree3(sbuf2,req_size,req_source1);CHKERRQ(ierr);
1538     ierr = PetscFree3(req_source2,rbuf2,rbuf3);CHKERRQ(ierr);
1539   }
1540   ierr = PetscFree5(irow,icol,nrow,ncol,issorted);CHKERRQ(ierr);
1541   ierr = PetscFree6(smats,row2proc,cmap,rmap,allcolumns,allrows);CHKERRQ(ierr);
1542 
1543   if (!ijonly) {
1544     ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
1545     ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
1546 
1547     for (i=0; i<nrqs; ++i) {
1548       ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);
1549     }
1550     ierr = PetscFree(rbuf4);CHKERRQ(ierr);
1551   }
1552   c->ijonly = PETSC_FALSE; /* set back to the default */
1553   PetscFunctionReturn(0);
1554 }
1555