xref: /petsc/src/mat/impls/aij/mpi/mpimatmatmult.c (revision f65364087b4bfa49e23d76fb5a70b92709f8f0ac)
1 
2 /*
3   Defines matrix-matrix product routines for pairs of MPIAIJ matrices
4           C = A * B
5 */
6 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
7 #include <../src/mat/utils/freespace.h>
8 #include <../src/mat/impls/aij/mpi/mpiaij.h>
9 #include <petscbt.h>
10 #include <../src/mat/impls/dense/mpi/mpidense.h>
11 
12 /* #define DEBUG_MATMATMULT */
13 
14 #undef __FUNCT__
15 #define __FUNCT__ "MatMatMult_MPIAIJ_MPIAIJ"
16 PetscErrorCode MatMatMult_MPIAIJ_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill, Mat *C)
17 {
18   PetscErrorCode ierr;
19 
20   PetscFunctionBegin;
21   if (scall == MAT_INITIAL_MATRIX){
22     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
23     ierr = MatMatMultSymbolic_MPIAIJ_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
24     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
25   }
26   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
27   ierr = (*(*C)->ops->matmultnumeric)(A,B,*C);CHKERRQ(ierr);
28   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
29   PetscFunctionReturn(0);
30 }
31 
32 #undef __FUNCT__
33 #define __FUNCT__ "PetscContainerDestroy_Mat_MatMatMultMPI"
34 PetscErrorCode PetscContainerDestroy_Mat_MatMatMultMPI(void *ptr)
35 {
36   PetscErrorCode       ierr;
37   Mat_MatMatMultMPI    *mult=(Mat_MatMatMultMPI*)ptr;
38 
39   PetscFunctionBegin;
40   ierr = ISDestroy(&mult->isrowa);CHKERRQ(ierr);
41   ierr = ISDestroy(&mult->isrowb);CHKERRQ(ierr);
42   ierr = ISDestroy(&mult->iscolb);CHKERRQ(ierr);
43   ierr = MatDestroy(&mult->C_seq);CHKERRQ(ierr);
44   ierr = MatDestroy(&mult->A_loc);CHKERRQ(ierr);
45   ierr = MatDestroy(&mult->B_seq);CHKERRQ(ierr);
46   ierr = PetscFree(mult);CHKERRQ(ierr);
47   PetscFunctionReturn(0);
48 }
49 
50 #undef __FUNCT__
51 #define __FUNCT__ "MatDestroy_MPIAIJ_MatMatMult"
52 PetscErrorCode MatDestroy_MPIAIJ_MatMatMult(Mat A)
53 {
54   PetscErrorCode ierr;
55   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
56   Mat_PtAPMPI    *ptap=a->ptap;
57 
58   PetscFunctionBegin;
59   ierr = PetscFree2(ptap->startsj,ptap->startsj_r);CHKERRQ(ierr);
60   ierr = PetscFree(ptap->bufa);CHKERRQ(ierr);
61   ierr = MatDestroy(&ptap->P_loc);CHKERRQ(ierr);
62   ierr = MatDestroy(&ptap->P_oth);CHKERRQ(ierr);
63   ierr = PetscFree(ptap->api);CHKERRQ(ierr);
64   ierr = PetscFree(ptap->apj);CHKERRQ(ierr);
65   ierr = PetscFree(ptap->apa);CHKERRQ(ierr);
66   ierr = ptap->destroy(A);CHKERRQ(ierr);
67   ierr = PetscFree(ptap);CHKERRQ(ierr);
68   PetscFunctionReturn(0);
69 }
70 
71 #undef __FUNCT__
72 #define __FUNCT__ "MatDestroy_MPIAIJ_MatMatMult_32"
73 PetscErrorCode MatDestroy_MPIAIJ_MatMatMult_32(Mat A)
74 {
75   PetscErrorCode     ierr;
76   PetscContainer     container;
77   Mat_MatMatMultMPI  *mult=PETSC_NULL;
78 
79   PetscFunctionBegin;
80   ierr = PetscObjectQuery((PetscObject)A,"Mat_MatMatMultMPI",(PetscObject *)&container);CHKERRQ(ierr);
81   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
82   ierr = PetscContainerGetPointer(container,(void **)&mult);CHKERRQ(ierr);
83   A->ops->destroy   = mult->destroy;
84   A->ops->duplicate = mult->duplicate;
85   if (A->ops->destroy) {
86     ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
87   }
88   ierr = PetscObjectCompose((PetscObject)A,"Mat_MatMatMultMPI",0);CHKERRQ(ierr);
89   PetscFunctionReturn(0);
90 }
91 
92 #undef __FUNCT__
93 #define __FUNCT__ "MatDuplicate_MPIAIJ_MatMatMult_32"
94 PetscErrorCode MatDuplicate_MPIAIJ_MatMatMult_32(Mat A, MatDuplicateOption op, Mat *M)
95 {
96   PetscErrorCode     ierr;
97   Mat_MatMatMultMPI  *mult;
98   PetscContainer     container;
99 
100   PetscFunctionBegin;
101   ierr = PetscObjectQuery((PetscObject)A,"Mat_MatMatMultMPI",(PetscObject *)&container);CHKERRQ(ierr);
102   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
103   ierr  = PetscContainerGetPointer(container,(void **)&mult);CHKERRQ(ierr);
104   /* Note: the container is not duplicated, because it requires deep copying of
105      several large data sets (see PetscContainerDestroy_Mat_MatMatMultMPI()).
106      These data sets are only used for repeated calling of MatMatMultNumeric().
107      *M is unlikely being used in this way. Thus we create *M with pure mpiaij format */
108   ierr = (*mult->duplicate)(A,op,M);CHKERRQ(ierr);
109   (*M)->ops->destroy   = mult->destroy;   /* = MatDestroy_MPIAIJ, *M doesn't duplicate A's container! */
110   (*M)->ops->duplicate = mult->duplicate; /* = MatDuplicate_MPIAIJ */
111   PetscFunctionReturn(0);
112 }
113 
114 #undef __FUNCT__
115 #define __FUNCT__ "MatDuplicate_MPIAIJ_MatMatMult"
116 PetscErrorCode MatDuplicate_MPIAIJ_MatMatMult(Mat A, MatDuplicateOption op, Mat *M)
117 {
118   PetscErrorCode     ierr;
119   Mat_MPIAIJ         *a=(Mat_MPIAIJ*)A->data;
120   Mat_PtAPMPI        *ptap=a->ptap;
121 
122   PetscFunctionBegin;
123   ierr = (*ptap->duplicate)(A,op,M);CHKERRQ(ierr);
124   (*M)->ops->destroy   = ptap->destroy;   /* = MatDestroy_MPIAIJ, *M doesn't duplicate A's special structure! */
125   (*M)->ops->duplicate = ptap->duplicate; /* = MatDuplicate_MPIAIJ */
126   PetscFunctionReturn(0);
127 }
128 
129 #undef __FUNCT__
130 #define __FUNCT__ "MatMatMultNumeric_MPIAIJ_MPIAIJ"
131 PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ(Mat A,Mat P,Mat C)
132 {
133   PetscErrorCode     ierr;
134   Mat_MPIAIJ         *a=(Mat_MPIAIJ*)A->data,*c=(Mat_MPIAIJ*)C->data;
135   Mat_SeqAIJ         *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data;
136   Mat_SeqAIJ         *cd=(Mat_SeqAIJ*)(c->A)->data,*co=(Mat_SeqAIJ*)(c->B)->data;
137   PetscInt           *adi=ad->i,*adj,*aoi=ao->i,*aoj;
138   PetscScalar        *ada,*aoa,*cda=cd->a,*coa=co->a;
139   Mat_SeqAIJ         *p_loc,*p_oth;
140   PetscInt           *pi_loc,*pj_loc,*pi_oth,*pj_oth,*pj;
141   PetscScalar        *pa_loc,*pa_oth,*pa,*apa,valtmp,*ca;
142   PetscInt           cm=C->rmap->n,anz,pnz;
143   Mat_PtAPMPI        *ptap=c->ptap;
144   PetscInt           *api,*apj,*apJ,i,j,k,row;
145   PetscInt           rstart=C->rmap->rstart,cstart=C->cmap->rstart;
146   PetscInt           cdnz,conz,k0,k1;
147 #if defined(DEBUG_MATMATMULT)
148   PetscMPIInt        rank=a->rank;
149 #endif
150 
151   PetscFunctionBegin;
152 #if defined(DEBUG_MATMATMULT)
153   if (!rank) ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] call MatMatMultNumeric_MPIAIJ_MPIAIJ()...\n",rank);
154 #endif
155 
156   /* 1) get P_oth = ptap->P_oth  and P_loc = ptap->P_loc */
157   /*-----------------------------------------------------*/
158   /* update numerical values of P_oth and P_loc */
159   ierr = MatGetBrowsOfAoCols_MPIAIJ(A,P,MAT_REUSE_MATRIX,&ptap->startsj,&ptap->startsj_r,&ptap->bufa,&ptap->P_oth);CHKERRQ(ierr);
160   ierr = MatMPIAIJGetLocalMat(P,MAT_REUSE_MATRIX,&ptap->P_loc);CHKERRQ(ierr);
161 
162   /* 2) compute numeric C_loc = A_loc*P = Ad*P_loc + Ao*P_oth */
163   /*----------------------------------------------------------*/
164   /* get data from symbolic products */
165   p_loc = (Mat_SeqAIJ*)(ptap->P_loc)->data;
166   p_oth = (Mat_SeqAIJ*)(ptap->P_oth)->data;
167   pi_loc=p_loc->i; pj_loc=p_loc->j; pa_loc=p_loc->a;
168   pi_oth=p_oth->i; pj_oth=p_oth->j; pa_oth=p_oth->a;
169 
170   /* get apa for storing dense row A[i,:]*P */
171   apa = ptap->apa;
172 
173   for (i=0; i<cm; i++) {
174     /* diagonal portion of A */
175     anz = adi[i+1] - adi[i];
176     adj = ad->j + adi[i];
177     ada = ad->a + adi[i];
178     for (j=0; j<anz; j++) {
179       row = adj[j];
180       pnz = pi_loc[row+1] - pi_loc[row];
181       pj  = pj_loc + pi_loc[row];
182       pa  = pa_loc + pi_loc[row];
183 
184       /* perform dense axpy */
185       valtmp = ada[j];
186       for (k=0; k<pnz; k++){
187         apa[pj[k]] += valtmp*pa[k];
188       }
189       ierr = PetscLogFlops(2.0*pnz);CHKERRQ(ierr);
190     }
191 
192     /* off-diagonal portion of A */
193     anz = aoi[i+1] - aoi[i];
194     aoj = ao->j + aoi[i];
195     aoa = ao->a + aoi[i];
196     for (j=0; j<anz; j++) {
197       row = aoj[j];
198       pnz = pi_oth[row+1] - pi_oth[row];
199       pj  = pj_oth + pi_oth[row];
200       pa  = pa_oth + pi_oth[row];
201 
202       /* perform dense axpy */
203       valtmp = aoa[j];
204       for (k=0; k<pnz; k++){
205         apa[pj[k]] += valtmp*pa[k];
206       }
207       ierr = PetscLogFlops(2.0*pnz);CHKERRQ(ierr);
208     }
209 
210     /* set values in C */
211     row = rstart + i;
212     api = ptap->api;
213     apj = ptap->apj;
214     apJ = apj + api[i];
215     cdnz = cd->i[i+1] - cd->i[i];
216     conz = co->i[i+1] - co->i[i];
217 
218     /* 1st off-diagoanl part of C */
219     ca = coa + co->i[i];
220     k  = 0;
221     for (k0=0; k0<conz; k0++){
222       if (apJ[k] >= cstart) break;
223       ca[k0]      = apa[apJ[k]];
224       apa[apJ[k]] = 0.0;
225       k++;
226     }
227 
228     /* diagonal part of C */
229     ca = cda + cd->i[i];
230     for (k1=0; k1<cdnz; k1++){
231       ca[k1]      = apa[apJ[k]];
232       apa[apJ[k]] = 0.0;
233       k++;
234     }
235 
236     /* 2nd off-diagoanl part of C */
237     ca = coa + co->i[i];
238     for (; k0<conz; k0++){
239       ca[k0]      = apa[apJ[k]];
240       apa[apJ[k]] = 0.0;
241       k++;
242     }
243   }
244   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
245   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
246   PetscFunctionReturn(0);
247 }
248 
249 #undef __FUNCT__
250 #define __FUNCT__ "MatMatMultSymbolic_MPIAIJ_MPIAIJ"
251 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat *C)
252 {
253   PetscErrorCode       ierr;
254   MPI_Comm             comm=((PetscObject)A)->comm;
255   Mat                  Cmpi;
256   Mat_PtAPMPI          *ptap;
257   PetscFreeSpaceList   free_space=PETSC_NULL,current_space=PETSC_NULL;
258   Mat_MPIAIJ           *a=(Mat_MPIAIJ*)A->data,*c;
259   Mat_SeqAIJ           *ad=(Mat_SeqAIJ*)(a->A)->data,*ao=(Mat_SeqAIJ*)(a->B)->data,*p_loc,*p_oth;
260   PetscInt             *pi_loc,*pj_loc,*pi_oth,*pj_oth,*dnz,*onz;
261   PetscInt             *adi=ad->i,*adj=ad->j,*aoi=ao->i,*aoj=ao->j,rstart=A->rmap->rstart;
262   PetscInt             nlnk,*lnk,i,pnz,row,*api,*apj,*Jptr,apnz,nspacedouble=0,j,nzi;
263   PetscInt             am=A->rmap->n,pN=P->cmap->N,pn=P->cmap->n,pm=P->rmap->n;
264   PetscBT              lnkbt;
265   PetscScalar          *apa;
266   PetscReal            afill;
267   PetscBool            matmatmult_old=PETSC_FALSE;
268 #if defined(DEBUG_MATMATMULT)
269   PetscMPIInt          rank=a->rank;
270 #endif
271 
272   PetscFunctionBegin;
273   if (A->cmap->rstart != P->rmap->rstart || A->cmap->rend != P->rmap->rend){
274     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%D, %D) != (%D,%D)",A->cmap->rstart,A->cmap->rend,P->rmap->rstart,P->rmap->rend);
275   }
276   ierr = PetscOptionsGetBool(PETSC_NULL,"-matmatmult_old",&matmatmult_old,PETSC_NULL);CHKERRQ(ierr);
277   if (matmatmult_old){
278     ierr = MatMatMultSymbolic_MPIAIJ_MPIAIJ_32(A,P,fill,C);;CHKERRQ(ierr);
279     PetscFunctionReturn(0);
280   }
281 
282 #if defined(DEBUG_MATMATMULT)
283   if (!rank) ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] call MatMatMultSymbolic_MPIAIJ_MPIAIJ()...\n",rank);
284 #endif
285 
286   /* create struct Mat_PtAPMPI and attached it to C later */
287   ierr = PetscNew(Mat_PtAPMPI,&ptap);CHKERRQ(ierr);
288 
289   /* malloc apa to store dense row A[i,:]*P */
290   ierr = PetscMalloc(pN*sizeof(PetscScalar),&apa);CHKERRQ(ierr);
291   ierr = PetscMemzero(apa,pN*sizeof(PetscScalar));CHKERRQ(ierr);
292   ptap->apa = apa;
293 
294   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
295   ierr = MatGetBrowsOfAoCols_MPIAIJ(A,P,MAT_INITIAL_MATRIX,&ptap->startsj,&ptap->startsj_r,&ptap->bufa,&ptap->P_oth);CHKERRQ(ierr);
296   /* get P_loc by taking all local rows of P */
297   ierr = MatMPIAIJGetLocalMat(P,MAT_INITIAL_MATRIX,&ptap->P_loc);CHKERRQ(ierr);
298 
299   p_loc = (Mat_SeqAIJ*)(ptap->P_loc)->data;
300   p_oth = (Mat_SeqAIJ*)(ptap->P_oth)->data;
301   pi_loc = p_loc->i; pj_loc = p_loc->j;
302   pi_oth = p_oth->i; pj_oth = p_oth->j;
303 
304   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
305   /*-------------------------------------------------------------------*/
306   ierr  = PetscMalloc((am+2)*sizeof(PetscInt),&api);CHKERRQ(ierr);
307   ptap->api = api;
308   api[0]    = 0;
309 
310   /* create and initialize a linked list */
311   nlnk = pN+1;
312   ierr = PetscLLCreate(pN,pN,nlnk,lnk,lnkbt);CHKERRQ(ierr);
313 
314   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
315   ierr = PetscFreeSpaceGet((PetscInt)(fill*(adi[am]+aoi[am]+pi_loc[pm])),&free_space);CHKERRQ(ierr);
316   current_space = free_space;
317 
318   ierr = MatPreallocateInitialize(comm,am,pn,dnz,onz);CHKERRQ(ierr);
319   for (i=0; i<am; i++) {
320     apnz = 0;
321     /* diagonal portion of A */
322     nzi = adi[i+1] - adi[i];
323     for (j=0; j<nzi; j++){
324       row = *adj++;
325       pnz = pi_loc[row+1] - pi_loc[row];
326       Jptr  = pj_loc + pi_loc[row];
327       /* add non-zero cols of P into the sorted linked list lnk */
328       ierr = PetscLLAddSorted(pnz,Jptr,pN,nlnk,lnk,lnkbt);CHKERRQ(ierr);
329       apnz += nlnk;
330     }
331     /* off-diagonal portion of A */
332     nzi = aoi[i+1] - aoi[i];
333     for (j=0; j<nzi; j++){
334       row = *aoj++;
335       pnz = pi_oth[row+1] - pi_oth[row];
336       Jptr  = pj_oth + pi_oth[row];
337       ierr = PetscLLAddSorted(pnz,Jptr,pN,nlnk,lnk,lnkbt);CHKERRQ(ierr);
338       apnz += nlnk;
339     }
340 
341     api[i+1] = api[i] + apnz;
342 
343     /* if free space is not available, double the total space in the list */
344     if (current_space->local_remaining<apnz) {
345       ierr = PetscFreeSpaceGet(apnz+current_space->total_array_size,&current_space);CHKERRQ(ierr);
346       nspacedouble++;
347     }
348 
349     /* Copy data into free space, then initialize lnk */
350     ierr = PetscLLClean(pN,pN,apnz,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
351     ierr = MatPreallocateSet(i+rstart,apnz,current_space->array,dnz,onz);CHKERRQ(ierr);
352     current_space->array           += apnz;
353     current_space->local_used      += apnz;
354     current_space->local_remaining -= apnz;
355   }
356 
357   /* Allocate space for apj, initialize apj, and */
358   /* destroy list of free space and other temporary array(s) */
359   ierr = PetscMalloc((api[am]+1)*sizeof(PetscInt),&ptap->apj);CHKERRQ(ierr);
360   apj  = ptap->apj;
361   ierr = PetscFreeSpaceContiguous(&free_space,ptap->apj);CHKERRQ(ierr);
362   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
363 
364   /* create and assemble symbolic parallel matrix Cmpi */
365   /*----------------------------------------------------*/
366   ierr = MatCreate(comm,&Cmpi);CHKERRQ(ierr);
367   ierr = MatSetSizes(Cmpi,am,pn,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
368   ierr = MatSetType(Cmpi,MATMPIAIJ);CHKERRQ(ierr);
369   ierr = MatMPIAIJSetPreallocation(Cmpi,0,dnz,0,onz);CHKERRQ(ierr);
370   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
371   ierr = MatSetBlockSize(Cmpi,1);CHKERRQ(ierr);
372   for (i=0; i<am; i++){
373     row  = i + rstart;
374     apnz = api[i+1] - api[i];
375     ierr = MatSetValues(Cmpi,1,&row,apnz,apj,apa,INSERT_VALUES);CHKERRQ(ierr);
376     apj += apnz;
377   }
378   ierr = MatAssemblyBegin(Cmpi,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
379   ierr = MatAssemblyEnd(Cmpi,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
380 
381   ptap->destroy             = Cmpi->ops->destroy;
382   ptap->duplicate           = Cmpi->ops->duplicate;
383   Cmpi->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ;
384   Cmpi->ops->destroy        = MatDestroy_MPIAIJ_MatMatMult;
385   Cmpi->ops->duplicate      = MatDuplicate_MPIAIJ_MatMatMult;
386 
387   /* attach the supporting struct to Cmpi for reuse */
388   c = (Mat_MPIAIJ*)Cmpi->data;
389   c->ptap  = ptap;
390 
391   *C = Cmpi;
392 
393   /* set MatInfo */
394   afill = (PetscReal)api[am]/(adi[am]+aoi[am]+pi_loc[pm]) + 1.e-5;
395   if (afill < 1.0) afill = 1.0;
396   Cmpi->info.mallocs           = nspacedouble;
397   Cmpi->info.fill_ratio_given  = fill;
398   Cmpi->info.fill_ratio_needed = afill;
399 
400 #if defined(PETSC_USE_INFO)
401   if (api[am]) {
402     ierr = PetscInfo3(Cmpi,"Reallocs %D; Fill ratio: given %G needed %G.\n",nspacedouble,fill,afill);CHKERRQ(ierr);
403     ierr = PetscInfo1(Cmpi,"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
404   } else {
405     ierr = PetscInfo(Cmpi,"Empty matrix product\n");CHKERRQ(ierr);
406   }
407 #endif
408   PetscFunctionReturn(0);
409 }
410 
411 /* implementation used in PETSc-3.2 */
412 /* This routine is called ONLY in the case of reusing previously computed symbolic C */
413 #undef __FUNCT__
414 #define __FUNCT__ "MatMatMultNumeric_MPIAIJ_MPIAIJ_32"
415 PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ_32(Mat A,Mat B,Mat C)
416 {
417   PetscErrorCode     ierr;
418   Mat                *seq;
419   Mat_MatMatMultMPI  *mult;
420   PetscContainer     container;
421 
422   PetscFunctionBegin;
423   ierr = PetscObjectQuery((PetscObject)C,"Mat_MatMatMultMPI",(PetscObject *)&container);CHKERRQ(ierr);
424   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
425   ierr  = PetscContainerGetPointer(container,(void **)&mult);CHKERRQ(ierr);
426 
427   if (mult->skipNumeric){ /* first numeric product is done during symbolic product */
428     mult->skipNumeric = PETSC_FALSE;
429     PetscFunctionReturn(0);
430   }
431 #if defined(DEBUG_MATMATMULT)
432   PetscMPIInt rank;
433   ierr = MPI_Comm_rank(((PetscObject)C)->comm,&rank);CHKERRQ(ierr);
434   if (!rank) ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] call MatMatMultNumeric_MPIAIJ_MPIAIJ_32()...\n",rank);
435 #endif
436 
437   seq = &mult->B_seq;
438   ierr = MatGetSubMatrices(B,1,&mult->isrowb,&mult->iscolb,MAT_REUSE_MATRIX,&seq);CHKERRQ(ierr);
439   mult->B_seq = *seq;
440 
441   seq = &mult->A_loc;
442   ierr = MatGetSubMatrices(A,1,&mult->isrowa,&mult->isrowb,MAT_REUSE_MATRIX,&seq);CHKERRQ(ierr);
443   mult->A_loc = *seq;
444 
445   ierr = MatMatMultNumeric_SeqAIJ_SeqAIJ_SparseAxpy(mult->A_loc,mult->B_seq,mult->C_seq);CHKERRQ(ierr);
446 
447   ierr = PetscObjectReference((PetscObject)mult->C_seq);CHKERRQ(ierr);
448   ierr = MatMerge(((PetscObject)A)->comm,mult->C_seq,B->cmap->n,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
449   PetscFunctionReturn(0);
450 }
451 
452 /* numeric product is computed as well */
453 #undef __FUNCT__
454 #define __FUNCT__ "MatMatMultSymbolic_MPIAIJ_MPIAIJ_32"
455 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ_32(Mat A,Mat B,PetscReal fill,Mat *C)
456 {
457   PetscErrorCode     ierr;
458   Mat_MatMatMultMPI  *mult;
459   PetscContainer     container;
460   Mat                AB,*seq;
461   Mat_MPIAIJ         *a=(Mat_MPIAIJ*)A->data;
462   PetscInt           *idx,i,start,ncols,nzA,nzB,*cmap,imark;
463 #if defined(DEBUG_MATMATMULT)
464   PetscMPIInt          rank=a->rank;
465 #endif
466 
467   PetscFunctionBegin;
468 #if defined(DEBUG_MATMATMULT)
469   if (!rank) ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] call MatMatMultSymbolic_MPIAIJ_MPIAIJ_32()...\n",rank);
470 #endif
471   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
472     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%D, %D) != (%D,%D)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
473   }
474 
475   ierr = PetscNew(Mat_MatMatMultMPI,&mult);CHKERRQ(ierr);
476 
477   /* get isrowb: nonzero col of A */
478   start = A->cmap->rstart;
479   cmap  = a->garray;
480   nzA   = a->A->cmap->n;
481   nzB   = a->B->cmap->n;
482   ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
483   ncols = 0;
484   for (i=0; i<nzB; i++) {  /* row < local row index */
485     if (cmap[i] < start) idx[ncols++] = cmap[i];
486     else break;
487   }
488   imark = i;
489   for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
490   for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
491   ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&mult->isrowb);CHKERRQ(ierr);
492   ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&mult->iscolb);CHKERRQ(ierr);
493 
494   /*  get isrowa: all local rows of A */
495   ierr = ISCreateStride(PETSC_COMM_SELF,A->rmap->n,A->rmap->rstart,1,&mult->isrowa);CHKERRQ(ierr);
496 
497   /* Below should go to MatMatMultNumeric_MPIAIJ_MPIAIJ() - How to generate C there? */
498   /* create a seq matrix B_seq = submatrix of B by taking rows of B that equal to nonzero col of A */
499   ierr = MatGetSubMatrices(B,1,&mult->isrowb,&mult->iscolb,MAT_INITIAL_MATRIX,&seq);CHKERRQ(ierr);
500   mult->B_seq = *seq;
501   ierr = PetscFree(seq);CHKERRQ(ierr);
502 
503   /*  create a seq matrix A_seq = submatrix of A by taking all local rows of A */
504   ierr = MatGetSubMatrices(A,1,&mult->isrowa,&mult->isrowb,MAT_INITIAL_MATRIX,&seq);CHKERRQ(ierr);
505   mult->A_loc = *seq;
506   ierr = PetscFree(seq);CHKERRQ(ierr);
507 
508   /* compute C_seq = A_seq * B_seq */
509   ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(mult->A_loc,mult->B_seq,fill,&mult->C_seq);CHKERRQ(ierr);
510   ierr = MatMatMultNumeric_SeqAIJ_SeqAIJ(mult->A_loc,mult->B_seq,mult->C_seq);CHKERRQ(ierr);
511 
512   /* create mpi matrix C by concatinating C_seq */
513   ierr = PetscObjectReference((PetscObject)mult->C_seq);CHKERRQ(ierr); /* prevent C_seq being destroyed by MatMerge() */
514   ierr = MatMergeSymbolic(((PetscObject)A)->comm,mult->C_seq,B->cmap->n,&AB);CHKERRQ(ierr);
515   ierr = MatMergeNumeric(((PetscObject)A)->comm,mult->C_seq,B->cmap->n,AB);CHKERRQ(ierr);
516 
517   /* attach the supporting struct to C for reuse of symbolic C */
518   ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
519   ierr = PetscContainerSetPointer(container,mult);CHKERRQ(ierr);
520   ierr = PetscContainerSetUserDestroy(container,PetscContainerDestroy_Mat_MatMatMultMPI);CHKERRQ(ierr);
521   ierr = PetscObjectCompose((PetscObject)AB,"Mat_MatMatMultMPI",(PetscObject)container);CHKERRQ(ierr);
522   ierr = PetscContainerDestroy(&container);CHKERRQ(ierr);
523   mult->skipNumeric  = PETSC_TRUE; /* a numeric product is done here */
524   mult->destroy      = AB->ops->destroy;
525   mult->duplicate    = AB->ops->duplicate;
526   AB->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ_32;
527   AB->ops->destroy        = MatDestroy_MPIAIJ_MatMatMult_32;
528   AB->ops->duplicate      = MatDuplicate_MPIAIJ_MatMatMult_32;
529   AB->ops->matmult        = MatMatMult_MPIAIJ_MPIAIJ;
530   *C                      = AB;
531   PetscFunctionReturn(0);
532 }
533 
534 #undef __FUNCT__
535 #define __FUNCT__ "MatMatMult_MPIAIJ_MPIDense"
536 PetscErrorCode MatMatMult_MPIAIJ_MPIDense(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
537 {
538   PetscErrorCode ierr;
539 
540   PetscFunctionBegin;
541   if (scall == MAT_INITIAL_MATRIX){
542     ierr = MatMatMultSymbolic_MPIAIJ_MPIDense(A,B,fill,C);CHKERRQ(ierr);
543   }
544   ierr = MatMatMultNumeric_MPIAIJ_MPIDense(A,B,*C);CHKERRQ(ierr);
545   PetscFunctionReturn(0);
546 }
547 
548 typedef struct {
549   Mat         workB;
550   PetscScalar *rvalues,*svalues;
551   MPI_Request *rwaits,*swaits;
552 } MPIAIJ_MPIDense;
553 
554 #undef __FUNCT__
555 #define __FUNCT__ "MPIAIJ_MPIDenseDestroy"
556 PetscErrorCode MPIAIJ_MPIDenseDestroy(void *ctx)
557 {
558   MPIAIJ_MPIDense *contents = (MPIAIJ_MPIDense*) ctx;
559   PetscErrorCode  ierr;
560 
561   PetscFunctionBegin;
562   ierr = MatDestroy(&contents->workB);CHKERRQ(ierr);
563   ierr = PetscFree4(contents->rvalues,contents->svalues,contents->rwaits,contents->swaits);CHKERRQ(ierr);
564   ierr = PetscFree(contents);CHKERRQ(ierr);
565   PetscFunctionReturn(0);
566 }
567 
568 #undef __FUNCT__
569 #define __FUNCT__ "MatMatMultSymbolic_MPIAIJ_MPIDense"
570 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIDense(Mat A,Mat B,PetscReal fill,Mat *C)
571 {
572   PetscErrorCode         ierr;
573   Mat_MPIAIJ             *aij = (Mat_MPIAIJ*) A->data;
574   PetscInt               nz = aij->B->cmap->n;
575   PetscContainer         container;
576   MPIAIJ_MPIDense        *contents;
577   VecScatter             ctx = aij->Mvctx;
578   VecScatter_MPI_General *from = (VecScatter_MPI_General*) ctx->fromdata;
579   VecScatter_MPI_General *to   = ( VecScatter_MPI_General*) ctx->todata;
580   PetscInt               m=A->rmap->n,n=B->cmap->n;
581 
582   PetscFunctionBegin;
583   ierr = MatCreate(((PetscObject)B)->comm,C);CHKERRQ(ierr);
584   ierr = MatSetSizes(*C,m,n,A->rmap->N,B->cmap->N);CHKERRQ(ierr);
585   ierr = MatSetType(*C,MATMPIDENSE);CHKERRQ(ierr);
586   ierr = MatAssemblyBegin(*C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
587   ierr = MatAssemblyEnd(*C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
588   (*C)->ops->matmult = MatMatMult_MPIAIJ_MPIDense;
589 
590   ierr = PetscNew(MPIAIJ_MPIDense,&contents);CHKERRQ(ierr);
591   /* Create work matrix used to store off processor rows of B needed for local product */
592   ierr = MatCreateSeqDense(PETSC_COMM_SELF,nz,B->cmap->N,PETSC_NULL,&contents->workB);CHKERRQ(ierr);
593   /* Create work arrays needed */
594   ierr = PetscMalloc4(B->cmap->N*from->starts[from->n],PetscScalar,&contents->rvalues,
595                       B->cmap->N*to->starts[to->n],PetscScalar,&contents->svalues,
596                       from->n,MPI_Request,&contents->rwaits,
597                       to->n,MPI_Request,&contents->swaits);CHKERRQ(ierr);
598 
599   ierr = PetscContainerCreate(((PetscObject)A)->comm,&container);CHKERRQ(ierr);
600   ierr = PetscContainerSetPointer(container,contents);CHKERRQ(ierr);
601   ierr = PetscContainerSetUserDestroy(container,MPIAIJ_MPIDenseDestroy);CHKERRQ(ierr);
602   ierr = PetscObjectCompose((PetscObject)(*C),"workB",(PetscObject)container);CHKERRQ(ierr);
603   ierr = PetscContainerDestroy(&container);CHKERRQ(ierr);
604   PetscFunctionReturn(0);
605 }
606 
607 #undef __FUNCT__
608 #define __FUNCT__ "MatMPIDenseScatter"
609 /*
610     Performs an efficient scatter on the rows of B needed by this process; this is
611     a modification of the VecScatterBegin_() routines.
612 */
613 PetscErrorCode MatMPIDenseScatter(Mat A,Mat B,Mat C,Mat *outworkB)
614 {
615   Mat_MPIAIJ             *aij = (Mat_MPIAIJ*)A->data;
616   PetscErrorCode         ierr;
617   PetscScalar            *b,*w,*svalues,*rvalues;
618   VecScatter             ctx = aij->Mvctx;
619   VecScatter_MPI_General *from = (VecScatter_MPI_General*) ctx->fromdata;
620   VecScatter_MPI_General *to   = ( VecScatter_MPI_General*) ctx->todata;
621   PetscInt               i,j,k;
622   PetscInt               *sindices,*sstarts,*rindices,*rstarts;
623   PetscMPIInt            *sprocs,*rprocs,nrecvs;
624   MPI_Request            *swaits,*rwaits;
625   MPI_Comm               comm = ((PetscObject)A)->comm;
626   PetscMPIInt            tag = ((PetscObject)ctx)->tag,ncols = B->cmap->N, nrows = aij->B->cmap->n,imdex,nrowsB = B->rmap->n;
627   MPI_Status             status;
628   MPIAIJ_MPIDense        *contents;
629   PetscContainer         container;
630   Mat                    workB;
631 
632   PetscFunctionBegin;
633   ierr = PetscObjectQuery((PetscObject)C,"workB",(PetscObject*)&container);CHKERRQ(ierr);
634   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
635   ierr = PetscContainerGetPointer(container,(void**)&contents);CHKERRQ(ierr);
636 
637   workB = *outworkB = contents->workB;
638   if (nrows != workB->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Number of rows of workB %D not equal to columns of aij->B %D",nrows,workB->cmap->n);
639   sindices  = to->indices;
640   sstarts   = to->starts;
641   sprocs    = to->procs;
642   swaits    = contents->swaits;
643   svalues   = contents->svalues;
644 
645   rindices  = from->indices;
646   rstarts   = from->starts;
647   rprocs    = from->procs;
648   rwaits    = contents->rwaits;
649   rvalues   = contents->rvalues;
650 
651   ierr = MatGetArray(B,&b);CHKERRQ(ierr);
652   ierr = MatGetArray(workB,&w);CHKERRQ(ierr);
653 
654   for (i=0; i<from->n; i++) {
655     ierr = MPI_Irecv(rvalues+ncols*rstarts[i],ncols*(rstarts[i+1]-rstarts[i]),MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
656   }
657 
658   for (i=0; i<to->n; i++) {
659     /* pack a message at a time */
660     CHKMEMQ;
661     for (j=0; j<sstarts[i+1]-sstarts[i]; j++){
662       for (k=0; k<ncols; k++) {
663         svalues[ncols*(sstarts[i] + j) + k] = b[sindices[sstarts[i]+j] + nrowsB*k];
664       }
665     }
666     CHKMEMQ;
667     ierr = MPI_Isend(svalues+ncols*sstarts[i],ncols*(sstarts[i+1]-sstarts[i]),MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
668   }
669 
670   nrecvs = from->n;
671   while (nrecvs) {
672     ierr = MPI_Waitany(from->n,rwaits,&imdex,&status);CHKERRQ(ierr);
673     nrecvs--;
674     /* unpack a message at a time */
675     CHKMEMQ;
676     for (j=0; j<rstarts[imdex+1]-rstarts[imdex]; j++){
677       for (k=0; k<ncols; k++) {
678         w[rindices[rstarts[imdex]+j] + nrows*k] = rvalues[ncols*(rstarts[imdex] + j) + k];
679       }
680     }
681     CHKMEMQ;
682   }
683   if (to->n) {ierr = MPI_Waitall(to->n,swaits,to->sstatus);CHKERRQ(ierr);}
684 
685   ierr = MatRestoreArray(B,&b);CHKERRQ(ierr);
686   ierr = MatRestoreArray(workB,&w);CHKERRQ(ierr);
687   ierr = MatAssemblyBegin(workB,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
688   ierr = MatAssemblyEnd(workB,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
689   PetscFunctionReturn(0);
690 }
691 extern PetscErrorCode MatMatMultNumericAdd_SeqAIJ_SeqDense(Mat,Mat,Mat);
692 
693 #undef __FUNCT__
694 #define __FUNCT__ "MatMatMultNumeric_MPIAIJ_MPIDense"
695 PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIDense(Mat A,Mat B,Mat C)
696 {
697   PetscErrorCode       ierr;
698   Mat_MPIAIJ           *aij = (Mat_MPIAIJ*)A->data;
699   Mat_MPIDense         *bdense = (Mat_MPIDense*)B->data;
700   Mat_MPIDense         *cdense = (Mat_MPIDense*)C->data;
701   Mat                  workB;
702 
703   PetscFunctionBegin;
704 
705   /* diagonal block of A times all local rows of B*/
706   ierr = MatMatMultNumeric_SeqAIJ_SeqDense(aij->A,bdense->A,cdense->A);CHKERRQ(ierr);
707 
708   /* get off processor parts of B needed to complete the product */
709   ierr = MatMPIDenseScatter(A,B,C,&workB);CHKERRQ(ierr);
710 
711   /* off-diagonal block of A times nonlocal rows of B */
712   ierr = MatMatMultNumericAdd_SeqAIJ_SeqDense(aij->B,workB,cdense->A);CHKERRQ(ierr);
713   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
714   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
715   PetscFunctionReturn(0);
716 }
717 
718