xref: /petsc/src/mat/impls/aij/mpi/mpimatmatmult.c (revision e4073758df262be4cddaafc2bc56880a0dd627aa)
1 /*
2   Defines matrix-matrix product routines for pairs of MPIAIJ matrices
3           C = A * B
4 */
5 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
6 #include <../src/mat/utils/freespace.h>
7 #include <../src/mat/impls/aij/mpi/mpiaij.h>
8 #include <petscbt.h>
9 #include <../src/mat/impls/dense/mpi/mpidense.h>
10 #include <petsc/private/vecimpl.h>
11 #include <petsc/private/sfimpl.h>
12 
13 #if defined(PETSC_HAVE_HYPRE)
14 PETSC_INTERN PetscErrorCode MatMatMultSymbolic_AIJ_AIJ_wHYPRE(Mat, Mat, PetscReal, Mat);
15 #endif
16 
MatProductSymbolic_ABt_MPIAIJ_MPIAIJ(Mat C)17 PETSC_INTERN PetscErrorCode MatProductSymbolic_ABt_MPIAIJ_MPIAIJ(Mat C)
18 {
19   Mat_Product *product = C->product;
20   Mat          B       = product->B;
21 
22   PetscFunctionBegin;
23   PetscCall(MatTranspose(B, MAT_INITIAL_MATRIX, &product->B));
24   PetscCall(MatDestroy(&B));
25   PetscCall(MatProductSymbolic_AB_MPIAIJ_MPIAIJ(C));
26   PetscFunctionReturn(PETSC_SUCCESS);
27 }
28 
MatProductSymbolic_AB_MPIAIJ_MPIAIJ(Mat C)29 PETSC_INTERN PetscErrorCode MatProductSymbolic_AB_MPIAIJ_MPIAIJ(Mat C)
30 {
31   Mat_Product        *product = C->product;
32   Mat                 A = product->A, B = product->B;
33   MatProductAlgorithm alg  = product->alg;
34   PetscReal           fill = product->fill;
35   PetscBool           flg;
36 
37   PetscFunctionBegin;
38   /* scalable */
39   PetscCall(PetscStrcmp(alg, "scalable", &flg));
40   if (flg) {
41     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ(A, B, fill, C));
42     PetscFunctionReturn(PETSC_SUCCESS);
43   }
44 
45   /* nonscalable */
46   PetscCall(PetscStrcmp(alg, "nonscalable", &flg));
47   if (flg) {
48     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(A, B, fill, C));
49     PetscFunctionReturn(PETSC_SUCCESS);
50   }
51 
52   /* seqmpi */
53   PetscCall(PetscStrcmp(alg, "seqmpi", &flg));
54   if (flg) {
55     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ_seqMPI(A, B, fill, C));
56     PetscFunctionReturn(PETSC_SUCCESS);
57   }
58 
59   /* backend general code */
60   PetscCall(PetscStrcmp(alg, "backend", &flg));
61   if (flg) {
62     PetscCall(MatProductSymbolic_MPIAIJBACKEND(C));
63     PetscFunctionReturn(PETSC_SUCCESS);
64   }
65 
66 #if defined(PETSC_HAVE_HYPRE)
67   PetscCall(PetscStrcmp(alg, "hypre", &flg));
68   if (flg) {
69     PetscCall(MatMatMultSymbolic_AIJ_AIJ_wHYPRE(A, B, fill, C));
70     PetscFunctionReturn(PETSC_SUCCESS);
71   }
72 #endif
73   SETERRQ(PetscObjectComm((PetscObject)C), PETSC_ERR_SUP, "Mat Product Algorithm is not supported");
74 }
75 
MatProductCtxDestroy_MPIAIJ_MatMatMult(PetscCtxRt data)76 PetscErrorCode MatProductCtxDestroy_MPIAIJ_MatMatMult(PetscCtxRt data)
77 {
78   MatProductCtx_APMPI *ptap = *(MatProductCtx_APMPI **)data;
79 
80   PetscFunctionBegin;
81   PetscCall(PetscFree2(ptap->startsj_s, ptap->startsj_r));
82   PetscCall(PetscFree(ptap->bufa));
83   PetscCall(MatDestroy(&ptap->P_loc));
84   PetscCall(MatDestroy(&ptap->P_oth));
85   PetscCall(MatDestroy(&ptap->Pt));
86   PetscCall(PetscFree(ptap->api));
87   PetscCall(PetscFree(ptap->apj));
88   PetscCall(PetscFree(ptap->apa));
89   PetscCall(PetscFree(ptap));
90   PetscFunctionReturn(PETSC_SUCCESS);
91 }
92 
MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat A,Mat P,Mat C)93 PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat A, Mat P, Mat C)
94 {
95   Mat_MPIAIJ          *a = (Mat_MPIAIJ *)A->data, *c = (Mat_MPIAIJ *)C->data;
96   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data;
97   Mat_SeqAIJ          *cd = (Mat_SeqAIJ *)c->A->data, *co = (Mat_SeqAIJ *)c->B->data;
98   PetscScalar         *cda, *coa;
99   Mat_SeqAIJ          *p_loc, *p_oth;
100   PetscScalar         *apa, *ca;
101   PetscInt             cm = C->rmap->n;
102   MatProductCtx_APMPI *ptap;
103   PetscInt            *api, *apj, *apJ, i, k;
104   PetscInt             cstart = C->cmap->rstart;
105   PetscInt             cdnz, conz, k0, k1;
106   const PetscScalar   *dummy1, *dummy2, *dummy3, *dummy4;
107   MPI_Comm             comm;
108   PetscMPIInt          size;
109 
110   PetscFunctionBegin;
111   MatCheckProduct(C, 3);
112   ptap = (MatProductCtx_APMPI *)C->product->data;
113   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
114   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
115   PetscCallMPI(MPI_Comm_size(comm, &size));
116   PetscCheck(ptap->P_oth || size <= 1, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "AP cannot be reused. Do not call MatProductClear()");
117 
118   /* flag CPU mask for C */
119 #if defined(PETSC_HAVE_DEVICE)
120   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
121   if (c->A->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->A->offloadmask = PETSC_OFFLOAD_CPU;
122   if (c->B->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->B->offloadmask = PETSC_OFFLOAD_CPU;
123 #endif
124 
125   /* 1) get P_oth = ptap->P_oth  and P_loc = ptap->P_loc */
126   /* update numerical values of P_oth and P_loc */
127   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_REUSE_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
128   PetscCall(MatMPIAIJGetLocalMat(P, MAT_REUSE_MATRIX, &ptap->P_loc));
129 
130   /* 2) compute numeric C_loc = A_loc*P = Ad*P_loc + Ao*P_oth */
131   /* get data from symbolic products */
132   p_loc = (Mat_SeqAIJ *)ptap->P_loc->data;
133   p_oth = NULL;
134   if (size > 1) p_oth = (Mat_SeqAIJ *)ptap->P_oth->data;
135 
136   /* get apa for storing dense row A[i,:]*P */
137   apa = ptap->apa;
138 
139   api = ptap->api;
140   apj = ptap->apj;
141   /* trigger copy to CPU */
142   PetscCall(MatSeqAIJGetArrayRead(a->A, &dummy1));
143   PetscCall(MatSeqAIJGetArrayRead(a->B, &dummy2));
144   PetscCall(MatSeqAIJGetArrayRead(ptap->P_loc, &dummy3));
145   if (ptap->P_oth) PetscCall(MatSeqAIJGetArrayRead(ptap->P_oth, &dummy4));
146   PetscCall(MatSeqAIJGetArrayWrite(c->A, &cda));
147   PetscCall(MatSeqAIJGetArrayWrite(c->B, &coa));
148   for (i = 0; i < cm; i++) {
149     /* compute apa = A[i,:]*P */
150     AProw_nonscalable(i, ad, ao, p_loc, p_oth, apa);
151 
152     /* set values in C */
153     apJ  = PetscSafePointerPlusOffset(apj, api[i]);
154     cdnz = cd->i[i + 1] - cd->i[i];
155     conz = co->i[i + 1] - co->i[i];
156 
157     /* 1st off-diagonal part of C */
158     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
159     k  = 0;
160     for (k0 = 0; k0 < conz; k0++) {
161       if (apJ[k] >= cstart) break;
162       ca[k0]        = apa[apJ[k]];
163       apa[apJ[k++]] = 0.0;
164     }
165 
166     /* diagonal part of C */
167     ca = PetscSafePointerPlusOffset(cda, cd->i[i]);
168     for (k1 = 0; k1 < cdnz; k1++) {
169       ca[k1]        = apa[apJ[k]];
170       apa[apJ[k++]] = 0.0;
171     }
172 
173     /* 2nd off-diagonal part of C */
174     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
175     for (; k0 < conz; k0++) {
176       ca[k0]        = apa[apJ[k]];
177       apa[apJ[k++]] = 0.0;
178     }
179   }
180   PetscCall(MatSeqAIJRestoreArrayRead(a->A, &dummy1));
181   PetscCall(MatSeqAIJRestoreArrayRead(a->B, &dummy2));
182   PetscCall(MatSeqAIJRestoreArrayRead(ptap->P_loc, &dummy3));
183   if (ptap->P_oth) PetscCall(MatSeqAIJRestoreArrayRead(ptap->P_oth, &dummy4));
184   PetscCall(MatSeqAIJRestoreArrayWrite(c->A, &cda));
185   PetscCall(MatSeqAIJRestoreArrayWrite(c->B, &coa));
186 
187   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
188   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
189   PetscFunctionReturn(PETSC_SUCCESS);
190 }
191 
MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat A,Mat P,PetscReal fill,Mat C)192 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat A, Mat P, PetscReal fill, Mat C)
193 {
194   MPI_Comm             comm;
195   PetscMPIInt          size;
196   MatProductCtx_APMPI *ptap;
197   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
198   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
199   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc, *p_oth;
200   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *dnz, *onz;
201   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, *aoj = ao->j, rstart = A->rmap->rstart;
202   PetscInt            *lnk, i, pnz, row, *api, *apj, *Jptr, apnz, nspacedouble = 0, j, nzi;
203   PetscInt             am = A->rmap->n, pN = P->cmap->N, pn = P->cmap->n, pm = P->rmap->n;
204   PetscBT              lnkbt;
205   PetscReal            afill;
206   MatType              mtype;
207 
208   PetscFunctionBegin;
209   MatCheckProduct(C, 4);
210   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
211   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
212   PetscCallMPI(MPI_Comm_size(comm, &size));
213 
214   /* create struct MatProductCtx_APMPI and attached it to C later */
215   PetscCall(PetscNew(&ptap));
216 
217   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
218   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
219 
220   /* get P_loc by taking all local rows of P */
221   PetscCall(MatMPIAIJGetLocalMat(P, MAT_INITIAL_MATRIX, &ptap->P_loc));
222 
223   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
224   pi_loc = p_loc->i;
225   pj_loc = p_loc->j;
226   if (size > 1) {
227     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
228     pi_oth = p_oth->i;
229     pj_oth = p_oth->j;
230   } else {
231     p_oth  = NULL;
232     pi_oth = NULL;
233     pj_oth = NULL;
234   }
235 
236   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
237   PetscCall(PetscMalloc1(am + 1, &api));
238   ptap->api = api;
239   api[0]    = 0;
240 
241   /* create and initialize a linked list */
242   PetscCall(PetscLLCondensedCreate(pN, pN, &lnk, &lnkbt));
243 
244   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
245   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space));
246   current_space = free_space;
247 
248   MatPreallocateBegin(comm, am, pn, dnz, onz);
249   for (i = 0; i < am; i++) {
250     /* diagonal portion of A */
251     nzi = adi[i + 1] - adi[i];
252     for (j = 0; j < nzi; j++) {
253       row  = *adj++;
254       pnz  = pi_loc[row + 1] - pi_loc[row];
255       Jptr = pj_loc + pi_loc[row];
256       /* add non-zero cols of P into the sorted linked list lnk */
257       PetscCall(PetscLLCondensedAddSorted(pnz, Jptr, lnk, lnkbt));
258     }
259     /* off-diagonal portion of A */
260     nzi = aoi[i + 1] - aoi[i];
261     for (j = 0; j < nzi; j++) {
262       row  = *aoj++;
263       pnz  = pi_oth[row + 1] - pi_oth[row];
264       Jptr = pj_oth + pi_oth[row];
265       PetscCall(PetscLLCondensedAddSorted(pnz, Jptr, lnk, lnkbt));
266     }
267     /* add possible missing diagonal entry */
268     if (C->force_diagonals) {
269       j = i + rstart; /* column index */
270       PetscCall(PetscLLCondensedAddSorted(1, &j, lnk, lnkbt));
271     }
272 
273     apnz       = lnk[0];
274     api[i + 1] = api[i] + apnz;
275 
276     /* if free space is not available, double the total space in the list */
277     if (current_space->local_remaining < apnz) {
278       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(apnz, current_space->total_array_size), &current_space));
279       nspacedouble++;
280     }
281 
282     /* Copy data into free space, then initialize lnk */
283     PetscCall(PetscLLCondensedClean(pN, apnz, current_space->array, lnk, lnkbt));
284     PetscCall(MatPreallocateSet(i + rstart, apnz, current_space->array, dnz, onz));
285 
286     current_space->array += apnz;
287     current_space->local_used += apnz;
288     current_space->local_remaining -= apnz;
289   }
290 
291   /* Allocate space for apj, initialize apj, and */
292   /* destroy list of free space and other temporary array(s) */
293   PetscCall(PetscMalloc1(api[am], &ptap->apj));
294   apj = ptap->apj;
295   PetscCall(PetscFreeSpaceContiguous(&free_space, ptap->apj));
296   PetscCall(PetscLLDestroy(lnk, lnkbt));
297 
298   /* malloc apa to store dense row A[i,:]*P */
299   PetscCall(PetscCalloc1(pN, &ptap->apa));
300 
301   /* set and assemble symbolic parallel matrix C */
302   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
303   PetscCall(MatSetBlockSizesFromMats(C, A, P));
304 
305   PetscCall(MatGetType(A, &mtype));
306   PetscCall(MatSetType(C, mtype));
307   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
308   MatPreallocateEnd(dnz, onz);
309 
310   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
311   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
312   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
313   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
314   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
315 
316   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;
317   C->ops->productnumeric = MatProductNumeric_AB;
318 
319   /* attach the supporting struct to C for reuse */
320   C->product->data    = ptap;
321   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;
322 
323   /* set MatInfo */
324   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
325   if (afill < 1.0) afill = 1.0;
326   C->info.mallocs           = nspacedouble;
327   C->info.fill_ratio_given  = fill;
328   C->info.fill_ratio_needed = afill;
329 
330 #if defined(PETSC_USE_INFO)
331   if (api[am]) {
332     PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
333     PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
334   } else {
335     PetscCall(PetscInfo(C, "Empty matrix product\n"));
336   }
337 #endif
338   PetscFunctionReturn(PETSC_SUCCESS);
339 }
340 
341 static PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIDense(Mat, Mat, PetscReal, Mat);
342 static PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIDense(Mat, Mat, Mat);
343 
MatProductSetFromOptions_MPIAIJ_MPIDense_AB(Mat C)344 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense_AB(Mat C)
345 {
346   Mat_Product *product = C->product;
347   Mat          A = product->A, B = product->B;
348 
349   PetscFunctionBegin;
350   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend)
351     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->cmap->rstart, A->cmap->rend, B->rmap->rstart, B->rmap->rend);
352 
353   C->ops->matmultsymbolic = MatMatMultSymbolic_MPIAIJ_MPIDense;
354   C->ops->productsymbolic = MatProductSymbolic_AB;
355   PetscFunctionReturn(PETSC_SUCCESS);
356 }
357 
MatProductSetFromOptions_MPIAIJ_MPIDense_AtB(Mat C)358 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense_AtB(Mat C)
359 {
360   Mat_Product *product = C->product;
361   Mat          A = product->A, B = product->B;
362 
363   PetscFunctionBegin;
364   if (A->rmap->rstart != B->rmap->rstart || A->rmap->rend != B->rmap->rend)
365     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, (%" PetscInt_FMT ", %" PetscInt_FMT ") != (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->rstart, A->rmap->rend, B->rmap->rstart, B->rmap->rend);
366 
367   C->ops->transposematmultsymbolic = MatTransposeMatMultSymbolic_MPIAIJ_MPIDense;
368   C->ops->productsymbolic          = MatProductSymbolic_AtB;
369   PetscFunctionReturn(PETSC_SUCCESS);
370 }
371 
MatProductSetFromOptions_MPIAIJ_MPIDense(Mat C)372 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_MPIAIJ_MPIDense(Mat C)
373 {
374   Mat_Product *product = C->product;
375 
376   PetscFunctionBegin;
377   switch (product->type) {
378   case MATPRODUCT_AB:
379     PetscCall(MatProductSetFromOptions_MPIAIJ_MPIDense_AB(C));
380     break;
381   case MATPRODUCT_AtB:
382     PetscCall(MatProductSetFromOptions_MPIAIJ_MPIDense_AtB(C));
383     break;
384   default:
385     break;
386   }
387   PetscFunctionReturn(PETSC_SUCCESS);
388 }
389 
390 typedef struct {
391   Mat           workB, workB1;
392   MPI_Request  *rwaits, *swaits;
393   PetscInt      nsends, nrecvs;
394   MPI_Datatype *stype, *rtype;
395   PetscInt      blda;
396 } MPIAIJ_MPIDense;
397 
MatMPIAIJ_MPIDenseDestroy(PetscCtxRt ctx)398 static PetscErrorCode MatMPIAIJ_MPIDenseDestroy(PetscCtxRt ctx)
399 {
400   MPIAIJ_MPIDense *contents = *(MPIAIJ_MPIDense **)ctx;
401   PetscInt         i;
402 
403   PetscFunctionBegin;
404   PetscCall(MatDestroy(&contents->workB));
405   PetscCall(MatDestroy(&contents->workB1));
406   for (i = 0; i < contents->nsends; i++) PetscCallMPI(MPI_Type_free(&contents->stype[i]));
407   for (i = 0; i < contents->nrecvs; i++) PetscCallMPI(MPI_Type_free(&contents->rtype[i]));
408   PetscCall(PetscFree4(contents->stype, contents->rtype, contents->rwaits, contents->swaits));
409   PetscCall(PetscFree(contents));
410   PetscFunctionReturn(PETSC_SUCCESS);
411 }
412 
MatMatMultSymbolic_MPIAIJ_MPIDense(Mat A,Mat B,PetscReal fill,Mat C)413 static PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIDense(Mat A, Mat B, PetscReal fill, Mat C)
414 {
415   Mat_MPIAIJ      *aij = (Mat_MPIAIJ *)A->data;
416   PetscInt         nz  = aij->B->cmap->n, blda, m, M, n, N;
417   MPIAIJ_MPIDense *contents;
418   VecScatter       ctx = aij->Mvctx;
419   PetscInt         Am = A->rmap->n, Bm = B->rmap->n, BN = B->cmap->N, Bbn, Bbn1, bs, numBb;
420   MPI_Comm         comm;
421   MPI_Datatype     type1, *stype, *rtype;
422   const PetscInt  *sindices, *sstarts, *rstarts;
423   PetscMPIInt     *disp, nsends, nrecvs, nrows_to, nrows_from;
424   PetscBool        cisdense;
425 
426   PetscFunctionBegin;
427   MatCheckProduct(C, 4);
428   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
429   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
430   PetscCall(PetscObjectBaseTypeCompare((PetscObject)C, MATMPIDENSE, &cisdense));
431   if (!cisdense) PetscCall(MatSetType(C, ((PetscObject)B)->type_name));
432   PetscCall(MatGetLocalSize(C, &m, &n));
433   PetscCall(MatGetSize(C, &M, &N));
434   if (m == PETSC_DECIDE || n == PETSC_DECIDE || M == PETSC_DECIDE || N == PETSC_DECIDE) PetscCall(MatSetSizes(C, Am, B->cmap->n, A->rmap->N, BN));
435   PetscCall(MatSetBlockSizesFromMats(C, A, B));
436   PetscCall(MatSetUp(C));
437   PetscCall(MatDenseGetLDA(B, &blda));
438   PetscCall(PetscNew(&contents));
439 
440   PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, NULL, NULL));
441   PetscCall(VecScatterGetRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, NULL, NULL));
442 
443   /* Create column block of B and C for memory scalability when BN is too large */
444   /* Estimate Bbn, column size of Bb */
445   if (nz) {
446     Bbn1 = 2 * Am * BN / nz;
447     if (!Bbn1) Bbn1 = 1;
448   } else Bbn1 = BN;
449 
450   bs   = B->cmap->bs;
451   Bbn1 = Bbn1 / bs * bs; /* Bbn1 is a multiple of bs */
452   if (Bbn1 > BN) Bbn1 = BN;
453   PetscCallMPI(MPIU_Allreduce(&Bbn1, &Bbn, 1, MPIU_INT, MPI_MAX, comm));
454 
455   /* Enable runtime option for Bbn */
456   PetscOptionsBegin(comm, ((PetscObject)C)->prefix, "MatProduct", "Mat");
457   PetscCall(PetscOptionsDeprecated("-matmatmult_Bbn", "-matproduct_batch_size", "3.25", NULL));
458   PetscCall(PetscOptionsInt("-matproduct_batch_size", "Number of columns in Bb", "MatProduct", Bbn, &Bbn, NULL));
459   PetscOptionsEnd();
460   Bbn = PetscMin(Bbn, BN);
461 
462   if (Bbn > 0 && Bbn < BN) {
463     numBb = BN / Bbn;
464     Bbn1  = BN - numBb * Bbn;
465   } else numBb = 0;
466 
467   if (numBb) {
468     PetscCall(PetscInfo(C, "use Bb, BN=%" PetscInt_FMT ", Bbn=%" PetscInt_FMT "; numBb=%" PetscInt_FMT "\n", BN, Bbn, numBb));
469     if (Bbn1) { /* Create workB1 for the remaining columns */
470       PetscCall(PetscInfo(C, "use Bb1, BN=%" PetscInt_FMT ", Bbn1=%" PetscInt_FMT "\n", BN, Bbn1));
471       /* Create work matrix used to store off processor rows of B needed for local product */
472       PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, nz, Bbn1, NULL, &contents->workB1));
473     } else contents->workB1 = NULL;
474   }
475 
476   /* Create work matrix used to store off processor rows of B needed for local product */
477   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, nz, Bbn, NULL, &contents->workB));
478 
479   /* Use MPI derived data type to reduce memory required by the send/recv buffers */
480   PetscCall(PetscMalloc4(nsends, &stype, nrecvs, &rtype, nrecvs, &contents->rwaits, nsends, &contents->swaits));
481   contents->stype  = stype;
482   contents->nsends = nsends;
483 
484   contents->rtype  = rtype;
485   contents->nrecvs = nrecvs;
486   contents->blda   = blda;
487 
488   PetscCall(PetscMalloc1(Bm, &disp));
489   for (PetscMPIInt i = 0; i < nsends; i++) {
490     PetscCall(PetscMPIIntCast(sstarts[i + 1] - sstarts[i], &nrows_to));
491     for (PetscInt j = 0; j < nrows_to; j++) PetscCall(PetscMPIIntCast(sindices[sstarts[i] + j], &disp[j])); /* rowB to be sent */
492     PetscCallMPI(MPI_Type_create_indexed_block(nrows_to, 1, disp, MPIU_SCALAR, &type1));
493     PetscCallMPI(MPI_Type_create_resized(type1, 0, blda * sizeof(PetscScalar), &stype[i]));
494     PetscCallMPI(MPI_Type_commit(&stype[i]));
495     PetscCallMPI(MPI_Type_free(&type1));
496   }
497 
498   for (PetscMPIInt i = 0; i < nrecvs; i++) {
499     /* received values from a process form a (nrows_from x Bbn) row block in workB (column-wise) */
500     PetscCall(PetscMPIIntCast(rstarts[i + 1] - rstarts[i], &nrows_from));
501     disp[0] = 0;
502     PetscCallMPI(MPI_Type_create_indexed_block(1, nrows_from, disp, MPIU_SCALAR, &type1));
503     PetscCallMPI(MPI_Type_create_resized(type1, 0, nz * sizeof(PetscScalar), &rtype[i]));
504     PetscCallMPI(MPI_Type_commit(&rtype[i]));
505     PetscCallMPI(MPI_Type_free(&type1));
506   }
507 
508   PetscCall(PetscFree(disp));
509   PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, NULL, NULL));
510   PetscCall(VecScatterRestoreRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, NULL, NULL));
511   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
512   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
513   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
514   PetscCall(MatProductClear(aij->A));
515   PetscCall(MatProductClear(((Mat_MPIDense *)B->data)->A));
516   PetscCall(MatProductClear(((Mat_MPIDense *)C->data)->A));
517   PetscCall(MatProductCreateWithMat(aij->A, ((Mat_MPIDense *)B->data)->A, NULL, ((Mat_MPIDense *)C->data)->A));
518   PetscCall(MatProductSetType(((Mat_MPIDense *)C->data)->A, MATPRODUCT_AB));
519   PetscCall(MatProductSetFromOptions(((Mat_MPIDense *)C->data)->A));
520   PetscCall(MatProductSymbolic(((Mat_MPIDense *)C->data)->A));
521   C->product->data       = contents;
522   C->product->destroy    = MatMPIAIJ_MPIDenseDestroy;
523   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIDense;
524   PetscFunctionReturn(PETSC_SUCCESS);
525 }
526 
527 PETSC_INTERN PetscErrorCode MatMatMultNumericAdd_SeqAIJ_SeqDense(Mat, Mat, Mat, const PetscBool);
528 
529 /*
530     Performs an efficient scatter on the rows of B needed by this process; this is
531     a modification of the VecScatterBegin_() routines.
532 
533     Input: If Bbidx = 0, uses B = Bb, else B = Bb1, see MatMatMultSymbolic_MPIAIJ_MPIDense()
534 */
535 
MatMPIDenseScatter(Mat A,Mat B,PetscInt Bbidx,Mat C,Mat * outworkB)536 static PetscErrorCode MatMPIDenseScatter(Mat A, Mat B, PetscInt Bbidx, Mat C, Mat *outworkB)
537 {
538   Mat_MPIAIJ        *aij = (Mat_MPIAIJ *)A->data;
539   const PetscScalar *b;
540   PetscScalar       *rvalues;
541   VecScatter         ctx = aij->Mvctx;
542   const PetscInt    *sindices, *sstarts, *rstarts;
543   const PetscMPIInt *sprocs, *rprocs;
544   PetscMPIInt        nsends, nrecvs;
545   MPI_Request       *swaits, *rwaits;
546   MPI_Comm           comm;
547   PetscMPIInt        tag = ((PetscObject)ctx)->tag, ncols, nrows, nsends_mpi, nrecvs_mpi;
548   MPIAIJ_MPIDense   *contents;
549   Mat                workB;
550   MPI_Datatype      *stype, *rtype;
551   PetscInt           blda;
552 
553   PetscFunctionBegin;
554   MatCheckProduct(C, 4);
555   PetscCheck(C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
556   PetscCall(PetscMPIIntCast(B->cmap->N, &ncols));
557   PetscCall(PetscMPIIntCast(aij->B->cmap->n, &nrows));
558   contents = (MPIAIJ_MPIDense *)C->product->data;
559   PetscCall(VecScatterGetRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, &sprocs, NULL /*bs*/));
560   PetscCall(VecScatterGetRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, &rprocs, NULL /*bs*/));
561   PetscCall(PetscMPIIntCast(nsends, &nsends_mpi));
562   PetscCall(PetscMPIIntCast(nrecvs, &nrecvs_mpi));
563   if (Bbidx == 0) workB = *outworkB = contents->workB;
564   else workB = *outworkB = contents->workB1;
565   PetscCheck(nrows == workB->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of rows of workB %" PetscInt_FMT " not equal to columns of aij->B %d", workB->cmap->n, nrows);
566   swaits = contents->swaits;
567   rwaits = contents->rwaits;
568 
569   PetscCall(MatDenseGetArrayRead(B, &b));
570   PetscCall(MatDenseGetLDA(B, &blda));
571   PetscCheck(blda == contents->blda, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cannot reuse an input matrix with lda %" PetscInt_FMT " != %" PetscInt_FMT, blda, contents->blda);
572   PetscCall(MatDenseGetArray(workB, &rvalues));
573 
574   /* Post recv, use MPI derived data type to save memory */
575   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
576   rtype = contents->rtype;
577   for (PetscMPIInt i = 0; i < nrecvs; i++) PetscCallMPI(MPIU_Irecv(rvalues + (rstarts[i] - rstarts[0]), ncols, rtype[i], rprocs[i], tag, comm, rwaits + i));
578 
579   stype = contents->stype;
580   for (PetscMPIInt i = 0; i < nsends; i++) PetscCallMPI(MPIU_Isend(b, ncols, stype[i], sprocs[i], tag, comm, swaits + i));
581 
582   if (nrecvs) PetscCallMPI(MPI_Waitall(nrecvs_mpi, rwaits, MPI_STATUSES_IGNORE));
583   if (nsends) PetscCallMPI(MPI_Waitall(nsends_mpi, swaits, MPI_STATUSES_IGNORE));
584 
585   PetscCall(VecScatterRestoreRemote_Private(ctx, PETSC_TRUE /*send*/, &nsends, &sstarts, &sindices, &sprocs, NULL));
586   PetscCall(VecScatterRestoreRemoteOrdered_Private(ctx, PETSC_FALSE /*recv*/, &nrecvs, &rstarts, NULL, &rprocs, NULL));
587   PetscCall(MatDenseRestoreArrayRead(B, &b));
588   PetscCall(MatDenseRestoreArray(workB, &rvalues));
589   PetscFunctionReturn(PETSC_SUCCESS);
590 }
591 
MatMatMultNumeric_MPIAIJ_MPIDense(Mat A,Mat B,Mat C)592 static PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIDense(Mat A, Mat B, Mat C)
593 {
594   Mat_MPIAIJ      *aij    = (Mat_MPIAIJ *)A->data;
595   Mat_MPIDense    *bdense = (Mat_MPIDense *)B->data;
596   Mat_MPIDense    *cdense = (Mat_MPIDense *)C->data;
597   Mat              workB;
598   MPIAIJ_MPIDense *contents;
599 
600   PetscFunctionBegin;
601   MatCheckProduct(C, 3);
602   PetscCheck(C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
603   contents = (MPIAIJ_MPIDense *)C->product->data;
604   /* diagonal block of A times all local rows of B, first make sure that everything is up-to-date */
605   if (!cdense->A->product) {
606     PetscCall(MatProductCreateWithMat(aij->A, bdense->A, NULL, cdense->A));
607     PetscCall(MatProductSetType(cdense->A, MATPRODUCT_AB));
608     PetscCall(MatProductSetFromOptions(cdense->A));
609     PetscCall(MatProductSymbolic(cdense->A));
610   } else PetscCall(MatProductReplaceMats(aij->A, bdense->A, NULL, cdense->A));
611   if (PetscDefined(HAVE_CUPM) && !cdense->A->product->clear) {
612     PetscBool flg;
613 
614     PetscCall(PetscObjectTypeCompare((PetscObject)C, MATMPIDENSE, &flg));
615     if (flg) PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMPIAIJ, &flg));
616     if (!flg) cdense->A->product->clear = PETSC_TRUE; /* if either A or C is a device Mat, make sure MatProductClear() is called */
617   }
618   PetscCall(MatProductNumeric(cdense->A));
619   if (contents->workB->cmap->n == B->cmap->N) {
620     /* get off processor parts of B needed to complete C=A*B */
621     PetscCall(MatMPIDenseScatter(A, B, 0, C, &workB));
622 
623     /* off-diagonal block of A times nonlocal rows of B */
624     PetscCall(MatMatMultNumericAdd_SeqAIJ_SeqDense(aij->B, workB, cdense->A, PETSC_TRUE));
625   } else {
626     Mat       Bb, Cb;
627     PetscInt  BN = B->cmap->N, n = contents->workB->cmap->n;
628     PetscBool ccpu;
629 
630     PetscCheck(n > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Column block size %" PetscInt_FMT " must be positive", n);
631     /* Prevent from unneeded copies back and forth from the GPU
632        when getting and restoring the submatrix
633        We need a proper GPU code for AIJ * dense in parallel */
634     PetscCall(MatBoundToCPU(C, &ccpu));
635     PetscCall(MatBindToCPU(C, PETSC_TRUE));
636     for (PetscInt i = 0; i < BN; i += n) {
637       PetscCall(MatDenseGetSubMatrix(B, PETSC_DECIDE, PETSC_DECIDE, i, PetscMin(i + n, BN), &Bb));
638       PetscCall(MatDenseGetSubMatrix(C, PETSC_DECIDE, PETSC_DECIDE, i, PetscMin(i + n, BN), &Cb));
639 
640       /* get off processor parts of B needed to complete C=A*B */
641       PetscCall(MatMPIDenseScatter(A, Bb, (i + n) > BN, C, &workB));
642 
643       /* off-diagonal block of A times nonlocal rows of B */
644       cdense = (Mat_MPIDense *)Cb->data;
645       PetscCall(MatMatMultNumericAdd_SeqAIJ_SeqDense(aij->B, workB, cdense->A, PETSC_TRUE));
646       PetscCall(MatDenseRestoreSubMatrix(B, &Bb));
647       PetscCall(MatDenseRestoreSubMatrix(C, &Cb));
648     }
649     PetscCall(MatBindToCPU(C, ccpu));
650   }
651   PetscFunctionReturn(PETSC_SUCCESS);
652 }
653 
MatMatMultNumeric_MPIAIJ_MPIAIJ(Mat A,Mat P,Mat C)654 PetscErrorCode MatMatMultNumeric_MPIAIJ_MPIAIJ(Mat A, Mat P, Mat C)
655 {
656   Mat_MPIAIJ          *a = (Mat_MPIAIJ *)A->data, *c = (Mat_MPIAIJ *)C->data;
657   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data;
658   Mat_SeqAIJ          *cd = (Mat_SeqAIJ *)c->A->data, *co = (Mat_SeqAIJ *)c->B->data;
659   PetscInt            *adi = ad->i, *adj, *aoi = ao->i, *aoj;
660   PetscScalar         *ada, *aoa, *cda = cd->a, *coa = co->a;
661   Mat_SeqAIJ          *p_loc, *p_oth;
662   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *pj;
663   PetscScalar         *pa_loc, *pa_oth, *pa, valtmp, *ca;
664   PetscInt             cm = C->rmap->n, anz, pnz;
665   MatProductCtx_APMPI *ptap;
666   PetscScalar         *apa_sparse;
667   const PetscScalar   *dummy;
668   PetscInt            *api, *apj, *apJ, i, j, k, row;
669   PetscInt             cstart = C->cmap->rstart;
670   PetscInt             cdnz, conz, k0, k1, nextp;
671   MPI_Comm             comm;
672   PetscMPIInt          size;
673 
674   PetscFunctionBegin;
675   MatCheckProduct(C, 3);
676   ptap = (MatProductCtx_APMPI *)C->product->data;
677   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
678   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
679   PetscCallMPI(MPI_Comm_size(comm, &size));
680   PetscCheck(ptap->P_oth || size <= 1, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "AP cannot be reused. Do not call MatProductClear()");
681 
682   /* flag CPU mask for C */
683 #if defined(PETSC_HAVE_DEVICE)
684   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
685   if (c->A->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->A->offloadmask = PETSC_OFFLOAD_CPU;
686   if (c->B->offloadmask != PETSC_OFFLOAD_UNALLOCATED) c->B->offloadmask = PETSC_OFFLOAD_CPU;
687 #endif
688   apa_sparse = ptap->apa;
689 
690   /* 1) get P_oth = ptap->P_oth  and P_loc = ptap->P_loc */
691   /* update numerical values of P_oth and P_loc */
692   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_REUSE_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
693   PetscCall(MatMPIAIJGetLocalMat(P, MAT_REUSE_MATRIX, &ptap->P_loc));
694 
695   /* 2) compute numeric C_loc = A_loc*P = Ad*P_loc + Ao*P_oth */
696   /* get data from symbolic products */
697   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
698   pi_loc = p_loc->i;
699   pj_loc = p_loc->j;
700   pa_loc = p_loc->a;
701   if (size > 1) {
702     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
703     pi_oth = p_oth->i;
704     pj_oth = p_oth->j;
705     pa_oth = p_oth->a;
706   } else {
707     p_oth  = NULL;
708     pi_oth = NULL;
709     pj_oth = NULL;
710     pa_oth = NULL;
711   }
712 
713   /* trigger copy to CPU */
714   PetscCall(MatSeqAIJGetArrayRead(a->A, &dummy));
715   PetscCall(MatSeqAIJRestoreArrayRead(a->A, &dummy));
716   PetscCall(MatSeqAIJGetArrayRead(a->B, &dummy));
717   PetscCall(MatSeqAIJRestoreArrayRead(a->B, &dummy));
718   api = ptap->api;
719   apj = ptap->apj;
720   for (i = 0; i < cm; i++) {
721     apJ = apj + api[i];
722 
723     /* diagonal portion of A */
724     anz = adi[i + 1] - adi[i];
725     adj = ad->j + adi[i];
726     ada = ad->a + adi[i];
727     for (j = 0; j < anz; j++) {
728       row = adj[j];
729       pnz = pi_loc[row + 1] - pi_loc[row];
730       pj  = pj_loc + pi_loc[row];
731       pa  = pa_loc + pi_loc[row];
732       /* perform sparse axpy */
733       valtmp = ada[j];
734       nextp  = 0;
735       for (k = 0; nextp < pnz; k++) {
736         if (apJ[k] == pj[nextp]) { /* column of AP == column of P */
737           apa_sparse[k] += valtmp * pa[nextp++];
738         }
739       }
740       PetscCall(PetscLogFlops(2.0 * pnz));
741     }
742 
743     /* off-diagonal portion of A */
744     anz = aoi[i + 1] - aoi[i];
745     aoj = PetscSafePointerPlusOffset(ao->j, aoi[i]);
746     aoa = PetscSafePointerPlusOffset(ao->a, aoi[i]);
747     for (j = 0; j < anz; j++) {
748       row = aoj[j];
749       pnz = pi_oth[row + 1] - pi_oth[row];
750       pj  = pj_oth + pi_oth[row];
751       pa  = pa_oth + pi_oth[row];
752       /* perform sparse axpy */
753       valtmp = aoa[j];
754       nextp  = 0;
755       for (k = 0; nextp < pnz; k++) {
756         if (apJ[k] == pj[nextp]) { /* column of AP == column of P */
757           apa_sparse[k] += valtmp * pa[nextp++];
758         }
759       }
760       PetscCall(PetscLogFlops(2.0 * pnz));
761     }
762 
763     /* set values in C */
764     cdnz = cd->i[i + 1] - cd->i[i];
765     conz = co->i[i + 1] - co->i[i];
766 
767     /* 1st off-diagonal part of C */
768     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
769     k  = 0;
770     for (k0 = 0; k0 < conz; k0++) {
771       if (apJ[k] >= cstart) break;
772       ca[k0]        = apa_sparse[k];
773       apa_sparse[k] = 0.0;
774       k++;
775     }
776 
777     /* diagonal part of C */
778     ca = cda + cd->i[i];
779     for (k1 = 0; k1 < cdnz; k1++) {
780       ca[k1]        = apa_sparse[k];
781       apa_sparse[k] = 0.0;
782       k++;
783     }
784 
785     /* 2nd off-diagonal part of C */
786     ca = PetscSafePointerPlusOffset(coa, co->i[i]);
787     for (; k0 < conz; k0++) {
788       ca[k0]        = apa_sparse[k];
789       apa_sparse[k] = 0.0;
790       k++;
791     }
792   }
793   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
794   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
795   PetscFunctionReturn(PETSC_SUCCESS);
796 }
797 
798 /* same as MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(), except using LLCondensed to avoid O(BN) memory requirement */
MatMatMultSymbolic_MPIAIJ_MPIAIJ(Mat A,Mat P,PetscReal fill,Mat C)799 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ(Mat A, Mat P, PetscReal fill, Mat C)
800 {
801   MPI_Comm             comm;
802   PetscMPIInt          size;
803   MatProductCtx_APMPI *ptap;
804   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
805   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
806   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc, *p_oth;
807   PetscInt            *pi_loc, *pj_loc, *pi_oth, *pj_oth, *dnz, *onz;
808   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, *aoj = ao->j, rstart = A->rmap->rstart;
809   PetscInt             i, pnz, row, *api, *apj, *Jptr, apnz, nspacedouble = 0, j, nzi, *lnk, apnz_max = 1;
810   PetscInt             am = A->rmap->n, pn = P->cmap->n, pm = P->rmap->n, lsize = pn + 20;
811   PetscReal            afill;
812   MatType              mtype;
813 
814   PetscFunctionBegin;
815   MatCheckProduct(C, 4);
816   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
817   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
818   PetscCallMPI(MPI_Comm_size(comm, &size));
819 
820   /* create struct MatProductCtx_APMPI and attached it to C later */
821   PetscCall(PetscNew(&ptap));
822 
823   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
824   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
825 
826   /* get P_loc by taking all local rows of P */
827   PetscCall(MatMPIAIJGetLocalMat(P, MAT_INITIAL_MATRIX, &ptap->P_loc));
828 
829   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
830   pi_loc = p_loc->i;
831   pj_loc = p_loc->j;
832   if (size > 1) {
833     p_oth  = (Mat_SeqAIJ *)ptap->P_oth->data;
834     pi_oth = p_oth->i;
835     pj_oth = p_oth->j;
836   } else {
837     p_oth  = NULL;
838     pi_oth = NULL;
839     pj_oth = NULL;
840   }
841 
842   /* first, compute symbolic AP = A_loc*P = A_diag*P_loc + A_off*P_oth */
843   PetscCall(PetscMalloc1(am + 1, &api));
844   ptap->api = api;
845   api[0]    = 0;
846 
847   PetscCall(PetscLLCondensedCreate_Scalable(lsize, &lnk));
848 
849   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
850   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space));
851   current_space = free_space;
852   MatPreallocateBegin(comm, am, pn, dnz, onz);
853   for (i = 0; i < am; i++) {
854     /* diagonal portion of A */
855     nzi = adi[i + 1] - adi[i];
856     for (j = 0; j < nzi; j++) {
857       row  = *adj++;
858       pnz  = pi_loc[row + 1] - pi_loc[row];
859       Jptr = pj_loc + pi_loc[row];
860       /* Expand list if it is not long enough */
861       if (pnz + apnz_max > lsize) {
862         lsize = pnz + apnz_max;
863         PetscCall(PetscLLCondensedExpand_Scalable(lsize, &lnk));
864       }
865       /* add non-zero cols of P into the sorted linked list lnk */
866       PetscCall(PetscLLCondensedAddSorted_Scalable(pnz, Jptr, lnk));
867       apnz       = *lnk; /* The first element in the list is the number of items in the list */
868       api[i + 1] = api[i] + apnz;
869       if (apnz > apnz_max) apnz_max = apnz + 1; /* '1' for diagonal entry */
870     }
871     /* off-diagonal portion of A */
872     nzi = aoi[i + 1] - aoi[i];
873     for (j = 0; j < nzi; j++) {
874       row  = *aoj++;
875       pnz  = pi_oth[row + 1] - pi_oth[row];
876       Jptr = pj_oth + pi_oth[row];
877       /* Expand list if it is not long enough */
878       if (pnz + apnz_max > lsize) {
879         lsize = pnz + apnz_max;
880         PetscCall(PetscLLCondensedExpand_Scalable(lsize, &lnk));
881       }
882       /* add non-zero cols of P into the sorted linked list lnk */
883       PetscCall(PetscLLCondensedAddSorted_Scalable(pnz, Jptr, lnk));
884       apnz       = *lnk; /* The first element in the list is the number of items in the list */
885       api[i + 1] = api[i] + apnz;
886       if (apnz > apnz_max) apnz_max = apnz + 1; /* '1' for diagonal entry */
887     }
888 
889     /* add missing diagonal entry */
890     if (C->force_diagonals) {
891       j = i + rstart; /* column index */
892       PetscCall(PetscLLCondensedAddSorted_Scalable(1, &j, lnk));
893     }
894 
895     apnz       = *lnk;
896     api[i + 1] = api[i] + apnz;
897     if (apnz > apnz_max) apnz_max = apnz;
898 
899     /* if free space is not available, double the total space in the list */
900     if (current_space->local_remaining < apnz) {
901       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(apnz, current_space->total_array_size), &current_space));
902       nspacedouble++;
903     }
904 
905     /* Copy data into free space, then initialize lnk */
906     PetscCall(PetscLLCondensedClean_Scalable(apnz, current_space->array, lnk));
907     PetscCall(MatPreallocateSet(i + rstart, apnz, current_space->array, dnz, onz));
908 
909     current_space->array += apnz;
910     current_space->local_used += apnz;
911     current_space->local_remaining -= apnz;
912   }
913 
914   /* Allocate space for apj, initialize apj, and */
915   /* destroy list of free space and other temporary array(s) */
916   PetscCall(PetscMalloc1(api[am], &ptap->apj));
917   apj = ptap->apj;
918   PetscCall(PetscFreeSpaceContiguous(&free_space, ptap->apj));
919   PetscCall(PetscLLCondensedDestroy_Scalable(lnk));
920 
921   /* create and assemble symbolic parallel matrix C */
922   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
923   PetscCall(MatSetBlockSizesFromMats(C, A, P));
924   PetscCall(MatGetType(A, &mtype));
925   PetscCall(MatSetType(C, mtype));
926   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
927   MatPreallocateEnd(dnz, onz);
928 
929   /* malloc apa for assembly C */
930   PetscCall(PetscCalloc1(apnz_max, &ptap->apa));
931 
932   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
933   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
934   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
935   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
936   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
937 
938   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ;
939   C->ops->productnumeric = MatProductNumeric_AB;
940 
941   /* attach the supporting struct to C for reuse */
942   C->product->data    = ptap;
943   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;
944 
945   /* set MatInfo */
946   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
947   if (afill < 1.0) afill = 1.0;
948   C->info.mallocs           = nspacedouble;
949   C->info.fill_ratio_given  = fill;
950   C->info.fill_ratio_needed = afill;
951 
952 #if defined(PETSC_USE_INFO)
953   if (api[am]) {
954     PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
955     PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
956   } else {
957     PetscCall(PetscInfo(C, "Empty matrix product\n"));
958   }
959 #endif
960   PetscFunctionReturn(PETSC_SUCCESS);
961 }
962 
963 /* This function is needed for the seqMPI matrix-matrix multiplication.  */
964 /* Three input arrays are merged to one output array. The size of the    */
965 /* output array is also output. Duplicate entries only show up once.     */
Merge3SortedArrays(PetscInt size1,PetscInt * in1,PetscInt size2,PetscInt * in2,PetscInt size3,PetscInt * in3,PetscInt * size4,PetscInt * out)966 static void Merge3SortedArrays(PetscInt size1, PetscInt *in1, PetscInt size2, PetscInt *in2, PetscInt size3, PetscInt *in3, PetscInt *size4, PetscInt *out)
967 {
968   int i = 0, j = 0, k = 0, l = 0;
969 
970   /* Traverse all three arrays */
971   while (i < size1 && j < size2 && k < size3) {
972     if (in1[i] < in2[j] && in1[i] < in3[k]) {
973       out[l++] = in1[i++];
974     } else if (in2[j] < in1[i] && in2[j] < in3[k]) {
975       out[l++] = in2[j++];
976     } else if (in3[k] < in1[i] && in3[k] < in2[j]) {
977       out[l++] = in3[k++];
978     } else if (in1[i] == in2[j] && in1[i] < in3[k]) {
979       out[l++] = in1[i];
980       i++, j++;
981     } else if (in1[i] == in3[k] && in1[i] < in2[j]) {
982       out[l++] = in1[i];
983       i++, k++;
984     } else if (in3[k] == in2[j] && in2[j] < in1[i]) {
985       out[l++] = in2[j];
986       k++, j++;
987     } else if (in1[i] == in2[j] && in1[i] == in3[k]) {
988       out[l++] = in1[i];
989       i++, j++, k++;
990     }
991   }
992 
993   /* Traverse two remaining arrays */
994   while (i < size1 && j < size2) {
995     if (in1[i] < in2[j]) {
996       out[l++] = in1[i++];
997     } else if (in1[i] > in2[j]) {
998       out[l++] = in2[j++];
999     } else {
1000       out[l++] = in1[i];
1001       i++, j++;
1002     }
1003   }
1004 
1005   while (i < size1 && k < size3) {
1006     if (in1[i] < in3[k]) {
1007       out[l++] = in1[i++];
1008     } else if (in1[i] > in3[k]) {
1009       out[l++] = in3[k++];
1010     } else {
1011       out[l++] = in1[i];
1012       i++, k++;
1013     }
1014   }
1015 
1016   while (k < size3 && j < size2) {
1017     if (in3[k] < in2[j]) {
1018       out[l++] = in3[k++];
1019     } else if (in3[k] > in2[j]) {
1020       out[l++] = in2[j++];
1021     } else {
1022       out[l++] = in3[k];
1023       k++, j++;
1024     }
1025   }
1026 
1027   /* Traverse one remaining array */
1028   while (i < size1) out[l++] = in1[i++];
1029   while (j < size2) out[l++] = in2[j++];
1030   while (k < size3) out[l++] = in3[k++];
1031 
1032   *size4 = l;
1033 }
1034 
1035 /* This matrix-matrix multiplication algorithm divides the multiplication into three multiplications and  */
1036 /* adds up the products. Two of these three multiplications are performed with existing (sequential)      */
1037 /* matrix-matrix multiplications.  */
MatMatMultSymbolic_MPIAIJ_MPIAIJ_seqMPI(Mat A,Mat P,PetscReal fill,Mat C)1038 PetscErrorCode MatMatMultSymbolic_MPIAIJ_MPIAIJ_seqMPI(Mat A, Mat P, PetscReal fill, Mat C)
1039 {
1040   MPI_Comm             comm;
1041   PetscMPIInt          size;
1042   MatProductCtx_APMPI *ptap;
1043   PetscFreeSpaceList   free_space_diag = NULL, current_space = NULL;
1044   Mat_MPIAIJ          *a  = (Mat_MPIAIJ *)A->data;
1045   Mat_SeqAIJ          *ad = (Mat_SeqAIJ *)a->A->data, *ao = (Mat_SeqAIJ *)a->B->data, *p_loc;
1046   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data;
1047   Mat_SeqAIJ          *adpd_seq, *p_off, *aopoth_seq;
1048   PetscInt             adponz, adpdnz;
1049   PetscInt            *pi_loc, *dnz, *onz;
1050   PetscInt            *adi = ad->i, *adj = ad->j, *aoi = ao->i, rstart = A->rmap->rstart;
1051   PetscInt            *lnk, i, i1 = 0, pnz, row, *adpoi, *adpoj, *api, *adpoJ, *aopJ, *apJ, *Jptr, aopnz, nspacedouble = 0, j, nzi, *apj, apnz, *adpdi, *adpdj, *adpdJ, *poff_i, *poff_j, *j_temp, *aopothi, *aopothj;
1052   PetscInt             am = A->rmap->n, pN = P->cmap->N, pn = P->cmap->n, pm = P->rmap->n, p_colstart, p_colend;
1053   PetscBT              lnkbt;
1054   PetscReal            afill;
1055   PetscMPIInt          rank;
1056   Mat                  adpd, aopoth;
1057   MatType              mtype;
1058   const char          *prefix;
1059 
1060   PetscFunctionBegin;
1061   MatCheckProduct(C, 4);
1062   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
1063   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1064   PetscCallMPI(MPI_Comm_size(comm, &size));
1065   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1066   PetscCall(MatGetOwnershipRangeColumn(P, &p_colstart, &p_colend));
1067 
1068   /* create struct MatProductCtx_APMPI and attached it to C later */
1069   PetscCall(PetscNew(&ptap));
1070 
1071   /* get P_oth by taking rows of P (= non-zero cols of local A) from other processors */
1072   PetscCall(MatGetBrowsOfAoCols_MPIAIJ(A, P, MAT_INITIAL_MATRIX, &ptap->startsj_s, &ptap->startsj_r, &ptap->bufa, &ptap->P_oth));
1073 
1074   /* get P_loc by taking all local rows of P */
1075   PetscCall(MatMPIAIJGetLocalMat(P, MAT_INITIAL_MATRIX, &ptap->P_loc));
1076 
1077   p_loc  = (Mat_SeqAIJ *)ptap->P_loc->data;
1078   pi_loc = p_loc->i;
1079 
1080   /* Allocate memory for the i arrays of the matrices A*P, A_diag*P_off and A_offd * P */
1081   PetscCall(PetscMalloc1(am + 1, &api));
1082   PetscCall(PetscMalloc1(am + 1, &adpoi));
1083 
1084   adpoi[0]  = 0;
1085   ptap->api = api;
1086   api[0]    = 0;
1087 
1088   /* create and initialize a linked list, will be used for both A_diag * P_loc_off and A_offd * P_oth */
1089   PetscCall(PetscLLCondensedCreate(pN, pN, &lnk, &lnkbt));
1090   MatPreallocateBegin(comm, am, pn, dnz, onz);
1091 
1092   /* Symbolic calc of A_loc_diag * P_loc_diag */
1093   PetscCall(MatGetOptionsPrefix(A, &prefix));
1094   PetscCall(MatProductCreate(a->A, p->A, NULL, &adpd));
1095   PetscCall(MatGetOptionsPrefix(A, &prefix));
1096   PetscCall(MatSetOptionsPrefix(adpd, prefix));
1097   PetscCall(MatAppendOptionsPrefix(adpd, "inner_diag_"));
1098 
1099   PetscCall(MatProductSetType(adpd, MATPRODUCT_AB));
1100   PetscCall(MatProductSetAlgorithm(adpd, "sorted"));
1101   PetscCall(MatProductSetFill(adpd, fill));
1102   PetscCall(MatProductSetFromOptions(adpd));
1103 
1104   adpd->force_diagonals = C->force_diagonals;
1105   PetscCall(MatProductSymbolic(adpd));
1106 
1107   adpd_seq = (Mat_SeqAIJ *)((adpd)->data);
1108   adpdi    = adpd_seq->i;
1109   adpdj    = adpd_seq->j;
1110   p_off    = (Mat_SeqAIJ *)p->B->data;
1111   poff_i   = p_off->i;
1112   poff_j   = p_off->j;
1113 
1114   /* j_temp stores indices of a result row before they are added to the linked list */
1115   PetscCall(PetscMalloc1(pN, &j_temp));
1116 
1117   /* Symbolic calc of the A_diag * p_loc_off */
1118   /* Initial FreeSpace size is fill*(nnz(A)+nnz(P)) */
1119   PetscCall(PetscFreeSpaceGet(PetscRealIntMultTruncate(fill, PetscIntSumTruncate(adi[am], PetscIntSumTruncate(aoi[am], pi_loc[pm]))), &free_space_diag));
1120   current_space = free_space_diag;
1121 
1122   for (i = 0; i < am; i++) {
1123     /* A_diag * P_loc_off */
1124     nzi = adi[i + 1] - adi[i];
1125     for (j = 0; j < nzi; j++) {
1126       row  = *adj++;
1127       pnz  = poff_i[row + 1] - poff_i[row];
1128       Jptr = poff_j + poff_i[row];
1129       for (i1 = 0; i1 < pnz; i1++) j_temp[i1] = p->garray[Jptr[i1]];
1130       /* add non-zero cols of P into the sorted linked list lnk */
1131       PetscCall(PetscLLCondensedAddSorted(pnz, j_temp, lnk, lnkbt));
1132     }
1133 
1134     adponz       = lnk[0];
1135     adpoi[i + 1] = adpoi[i] + adponz;
1136 
1137     /* if free space is not available, double the total space in the list */
1138     if (current_space->local_remaining < adponz) {
1139       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(adponz, current_space->total_array_size), &current_space));
1140       nspacedouble++;
1141     }
1142 
1143     /* Copy data into free space, then initialize lnk */
1144     PetscCall(PetscLLCondensedClean(pN, adponz, current_space->array, lnk, lnkbt));
1145 
1146     current_space->array += adponz;
1147     current_space->local_used += adponz;
1148     current_space->local_remaining -= adponz;
1149   }
1150 
1151   /* Symbolic calc of A_off * P_oth */
1152   PetscCall(MatSetOptionsPrefix(a->B, prefix));
1153   PetscCall(MatAppendOptionsPrefix(a->B, "inner_offdiag_"));
1154   PetscCall(MatCreate(PETSC_COMM_SELF, &aopoth));
1155   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(a->B, ptap->P_oth, fill, aopoth));
1156   aopoth_seq = (Mat_SeqAIJ *)((aopoth)->data);
1157   aopothi    = aopoth_seq->i;
1158   aopothj    = aopoth_seq->j;
1159 
1160   /* Allocate space for apj, adpj, aopj, ... */
1161   /* destroy lists of free space and other temporary array(s) */
1162 
1163   PetscCall(PetscMalloc1(aopothi[am] + adpoi[am] + adpdi[am], &ptap->apj));
1164   PetscCall(PetscMalloc1(adpoi[am], &adpoj));
1165 
1166   /* Copy from linked list to j-array */
1167   PetscCall(PetscFreeSpaceContiguous(&free_space_diag, adpoj));
1168   PetscCall(PetscLLDestroy(lnk, lnkbt));
1169 
1170   adpoJ = adpoj;
1171   adpdJ = adpdj;
1172   aopJ  = aopothj;
1173   apj   = ptap->apj;
1174   apJ   = apj; /* still empty */
1175 
1176   /* Merge j-arrays of A_off * P, A_diag * P_loc_off, and */
1177   /* A_diag * P_loc_diag to get A*P */
1178   for (i = 0; i < am; i++) {
1179     aopnz  = aopothi[i + 1] - aopothi[i];
1180     adponz = adpoi[i + 1] - adpoi[i];
1181     adpdnz = adpdi[i + 1] - adpdi[i];
1182 
1183     /* Correct indices from A_diag*P_diag */
1184     for (i1 = 0; i1 < adpdnz; i1++) adpdJ[i1] += p_colstart;
1185     /* Merge j-arrays of A_diag * P_loc_off and A_diag * P_loc_diag and A_off * P_oth */
1186     Merge3SortedArrays(adponz, adpoJ, adpdnz, adpdJ, aopnz, aopJ, &apnz, apJ);
1187     PetscCall(MatPreallocateSet(i + rstart, apnz, apJ, dnz, onz));
1188 
1189     aopJ += aopnz;
1190     adpoJ += adponz;
1191     adpdJ += adpdnz;
1192     apJ += apnz;
1193     api[i + 1] = api[i] + apnz;
1194   }
1195 
1196   /* malloc apa to store dense row A[i,:]*P */
1197   PetscCall(PetscCalloc1(pN, &ptap->apa));
1198 
1199   /* create and assemble symbolic parallel matrix C */
1200   PetscCall(MatSetSizes(C, am, pn, PETSC_DETERMINE, PETSC_DETERMINE));
1201   PetscCall(MatSetBlockSizesFromMats(C, A, P));
1202   PetscCall(MatGetType(A, &mtype));
1203   PetscCall(MatSetType(C, mtype));
1204   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
1205   MatPreallocateEnd(dnz, onz);
1206 
1207   PetscCall(MatSetValues_MPIAIJ_CopyFromCSRFormat_Symbolic(C, apj, api));
1208   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
1209   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1210   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1211   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
1212 
1213   C->ops->matmultnumeric = MatMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;
1214   C->ops->productnumeric = MatProductNumeric_AB;
1215 
1216   /* attach the supporting struct to C for reuse */
1217   C->product->data    = ptap;
1218   C->product->destroy = MatProductCtxDestroy_MPIAIJ_MatMatMult;
1219 
1220   /* set MatInfo */
1221   afill = (PetscReal)api[am] / (adi[am] + aoi[am] + pi_loc[pm] + 1) + 1.e-5;
1222   if (afill < 1.0) afill = 1.0;
1223   C->info.mallocs           = nspacedouble;
1224   C->info.fill_ratio_given  = fill;
1225   C->info.fill_ratio_needed = afill;
1226 
1227 #if defined(PETSC_USE_INFO)
1228   if (api[am]) {
1229     PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
1230     PetscCall(PetscInfo(C, "Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n", (double)afill));
1231   } else {
1232     PetscCall(PetscInfo(C, "Empty matrix product\n"));
1233   }
1234 #endif
1235 
1236   PetscCall(MatDestroy(&aopoth));
1237   PetscCall(MatDestroy(&adpd));
1238   PetscCall(PetscFree(j_temp));
1239   PetscCall(PetscFree(adpoj));
1240   PetscCall(PetscFree(adpoi));
1241   PetscFunctionReturn(PETSC_SUCCESS);
1242 }
1243 
1244 /* This routine only works when scall=MAT_REUSE_MATRIX! */
MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_matmatmult(Mat P,Mat A,Mat C)1245 PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_matmatmult(Mat P, Mat A, Mat C)
1246 {
1247   MatProductCtx_APMPI *ptap;
1248   Mat                  Pt;
1249 
1250   PetscFunctionBegin;
1251   MatCheckProduct(C, 3);
1252   ptap = (MatProductCtx_APMPI *)C->product->data;
1253   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
1254   PetscCheck(ptap->Pt, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");
1255 
1256   Pt = ptap->Pt;
1257   PetscCall(MatTransposeSetPrecursor(P, Pt));
1258   PetscCall(MatTranspose(P, MAT_REUSE_MATRIX, &Pt));
1259   PetscCall(MatMatMultNumeric_MPIAIJ_MPIAIJ(Pt, A, C));
1260   PetscFunctionReturn(PETSC_SUCCESS);
1261 }
1262 
1263 /* This routine is modified from MatPtAPSymbolic_MPIAIJ_MPIAIJ() */
MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat P,Mat A,PetscReal fill,Mat C)1264 PetscErrorCode MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(Mat P, Mat A, PetscReal fill, Mat C)
1265 {
1266   MatProductCtx_APMPI     *ptap;
1267   Mat_MPIAIJ              *p = (Mat_MPIAIJ *)P->data;
1268   MPI_Comm                 comm;
1269   PetscMPIInt              size, rank;
1270   PetscFreeSpaceList       free_space = NULL, current_space = NULL;
1271   PetscInt                 pn = P->cmap->n, aN = A->cmap->N, an = A->cmap->n;
1272   PetscInt                *lnk, i, k, rstart;
1273   PetscBT                  lnkbt;
1274   PetscMPIInt              tagi, tagj, *len_si, *len_s, *len_ri, nrecv, proc, nsend;
1275   PETSC_UNUSED PetscMPIInt icompleted = 0;
1276   PetscInt               **buf_rj, **buf_ri, **buf_ri_k, row, ncols, *cols;
1277   PetscInt                 len, *dnz, *onz, *owners, nzi;
1278   PetscInt                 nrows, *buf_s, *buf_si, *buf_si_i, **nextrow, **nextci;
1279   MPI_Request             *swaits, *rwaits;
1280   MPI_Status              *sstatus, rstatus;
1281   PetscLayout              rowmap;
1282   PetscInt                *owners_co, *coi, *coj; /* i and j array of (p->B)^T*A*P - used in the communication */
1283   PetscMPIInt             *len_r, *id_r;          /* array of length of comm->size, store send/recv matrix values */
1284   PetscInt                *Jptr, *prmap = p->garray, con, j, Crmax;
1285   Mat_SeqAIJ              *a_loc, *c_loc, *c_oth;
1286   PetscHMapI               ta;
1287   MatType                  mtype;
1288   const char              *prefix;
1289 
1290   PetscFunctionBegin;
1291   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1292   PetscCallMPI(MPI_Comm_size(comm, &size));
1293   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1294 
1295   /* create symbolic parallel matrix C */
1296   PetscCall(MatGetType(A, &mtype));
1297   PetscCall(MatSetType(C, mtype));
1298 
1299   C->ops->transposematmultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable;
1300 
1301   /* create struct MatProductCtx_APMPI and attached it to C later */
1302   PetscCall(PetscNew(&ptap));
1303 
1304   /* (0) compute Rd = Pd^T, Ro = Po^T  */
1305   PetscCall(MatTranspose(p->A, MAT_INITIAL_MATRIX, &ptap->Rd));
1306   PetscCall(MatTranspose(p->B, MAT_INITIAL_MATRIX, &ptap->Ro));
1307 
1308   /* (1) compute symbolic A_loc */
1309   PetscCall(MatMPIAIJGetLocalMat(A, MAT_INITIAL_MATRIX, &ptap->A_loc));
1310 
1311   /* (2-1) compute symbolic C_oth = Ro*A_loc  */
1312   PetscCall(MatGetOptionsPrefix(A, &prefix));
1313   PetscCall(MatSetOptionsPrefix(ptap->Ro, prefix));
1314   PetscCall(MatAppendOptionsPrefix(ptap->Ro, "inner_offdiag_"));
1315   PetscCall(MatCreate(PETSC_COMM_SELF, &ptap->C_oth));
1316   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(ptap->Ro, ptap->A_loc, fill, ptap->C_oth));
1317 
1318   /* (3) send coj of C_oth to other processors  */
1319   /* determine row ownership */
1320   PetscCall(PetscLayoutCreate(comm, &rowmap));
1321   rowmap->n  = pn;
1322   rowmap->bs = 1;
1323   PetscCall(PetscLayoutSetUp(rowmap));
1324   owners = rowmap->range;
1325 
1326   /* determine the number of messages to send, their lengths */
1327   PetscCall(PetscMalloc4(size, &len_s, size, &len_si, size, &sstatus, size + 1, &owners_co));
1328   PetscCall(PetscArrayzero(len_s, size));
1329   PetscCall(PetscArrayzero(len_si, size));
1330 
1331   c_oth = (Mat_SeqAIJ *)ptap->C_oth->data;
1332   coi   = c_oth->i;
1333   coj   = c_oth->j;
1334   con   = ptap->C_oth->rmap->n;
1335   proc  = 0;
1336   for (i = 0; i < con; i++) {
1337     while (prmap[i] >= owners[proc + 1]) proc++;
1338     len_si[proc]++;                     /* num of rows in Co(=Pt*A) to be sent to [proc] */
1339     len_s[proc] += coi[i + 1] - coi[i]; /* num of nonzeros in Co to be sent to [proc] */
1340   }
1341 
1342   len          = 0; /* max length of buf_si[], see (4) */
1343   owners_co[0] = 0;
1344   nsend        = 0;
1345   for (proc = 0; proc < size; proc++) {
1346     owners_co[proc + 1] = owners_co[proc] + len_si[proc];
1347     if (len_s[proc]) {
1348       nsend++;
1349       len_si[proc] = 2 * (len_si[proc] + 1); /* length of buf_si to be sent to [proc] */
1350       len += len_si[proc];
1351     }
1352   }
1353 
1354   /* determine the number and length of messages to receive for coi and coj  */
1355   PetscCall(PetscGatherNumberOfMessages(comm, NULL, len_s, &nrecv));
1356   PetscCall(PetscGatherMessageLengths2(comm, nsend, nrecv, len_s, len_si, &id_r, &len_r, &len_ri));
1357 
1358   /* post the Irecv and Isend of coj */
1359   PetscCall(PetscCommGetNewTag(comm, &tagj));
1360   PetscCall(PetscPostIrecvInt(comm, tagj, nrecv, id_r, len_r, &buf_rj, &rwaits));
1361   PetscCall(PetscMalloc1(nsend, &swaits));
1362   for (proc = 0, k = 0; proc < size; proc++) {
1363     if (!len_s[proc]) continue;
1364     i = owners_co[proc];
1365     PetscCallMPI(MPIU_Isend(coj + coi[i], len_s[proc], MPIU_INT, proc, tagj, comm, swaits + k));
1366     k++;
1367   }
1368 
1369   /* (2-2) compute symbolic C_loc = Rd*A_loc */
1370   PetscCall(MatSetOptionsPrefix(ptap->Rd, prefix));
1371   PetscCall(MatAppendOptionsPrefix(ptap->Rd, "inner_diag_"));
1372   PetscCall(MatCreate(PETSC_COMM_SELF, &ptap->C_loc));
1373   PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(ptap->Rd, ptap->A_loc, fill, ptap->C_loc));
1374   c_loc = (Mat_SeqAIJ *)ptap->C_loc->data;
1375 
1376   /* receives coj are complete */
1377   for (i = 0; i < nrecv; i++) PetscCallMPI(MPI_Waitany(nrecv, rwaits, &icompleted, &rstatus));
1378   PetscCall(PetscFree(rwaits));
1379   if (nsend) PetscCallMPI(MPI_Waitall(nsend, swaits, sstatus));
1380 
1381   /* add received column indices into ta to update Crmax */
1382   a_loc = (Mat_SeqAIJ *)ptap->A_loc->data;
1383 
1384   /* create and initialize a linked list */
1385   PetscCall(PetscHMapICreateWithSize(an, &ta)); /* for compute Crmax */
1386   MatRowMergeMax_SeqAIJ(a_loc, ptap->A_loc->rmap->N, ta);
1387 
1388   for (k = 0; k < nrecv; k++) { /* k-th received message */
1389     Jptr = buf_rj[k];
1390     for (j = 0; j < len_r[k]; j++) PetscCall(PetscHMapISet(ta, *(Jptr + j) + 1, 1));
1391   }
1392   PetscCall(PetscHMapIGetSize(ta, &Crmax));
1393   PetscCall(PetscHMapIDestroy(&ta));
1394 
1395   /* (4) send and recv coi */
1396   PetscCall(PetscCommGetNewTag(comm, &tagi));
1397   PetscCall(PetscPostIrecvInt(comm, tagi, nrecv, id_r, len_ri, &buf_ri, &rwaits));
1398   PetscCall(PetscMalloc1(len, &buf_s));
1399   buf_si = buf_s; /* points to the beginning of k-th msg to be sent */
1400   for (proc = 0, k = 0; proc < size; proc++) {
1401     if (!len_s[proc]) continue;
1402     /* form outgoing message for i-structure:
1403          buf_si[0]:                 nrows to be sent
1404                [1:nrows]:           row index (global)
1405                [nrows+1:2*nrows+1]: i-structure index
1406     */
1407     nrows       = len_si[proc] / 2 - 1; /* num of rows in Co to be sent to [proc] */
1408     buf_si_i    = buf_si + nrows + 1;
1409     buf_si[0]   = nrows;
1410     buf_si_i[0] = 0;
1411     nrows       = 0;
1412     for (i = owners_co[proc]; i < owners_co[proc + 1]; i++) {
1413       nzi                 = coi[i + 1] - coi[i];
1414       buf_si_i[nrows + 1] = buf_si_i[nrows] + nzi;   /* i-structure */
1415       buf_si[nrows + 1]   = prmap[i] - owners[proc]; /* local row index */
1416       nrows++;
1417     }
1418     PetscCallMPI(MPIU_Isend(buf_si, len_si[proc], MPIU_INT, proc, tagi, comm, swaits + k));
1419     k++;
1420     buf_si += len_si[proc];
1421   }
1422   for (i = 0; i < nrecv; i++) PetscCallMPI(MPI_Waitany(nrecv, rwaits, &icompleted, &rstatus));
1423   PetscCall(PetscFree(rwaits));
1424   if (nsend) PetscCallMPI(MPI_Waitall(nsend, swaits, sstatus));
1425 
1426   PetscCall(PetscFree4(len_s, len_si, sstatus, owners_co));
1427   PetscCall(PetscFree(len_ri));
1428   PetscCall(PetscFree(swaits));
1429   PetscCall(PetscFree(buf_s));
1430 
1431   /* (5) compute the local portion of C      */
1432   /* set initial free space to be Crmax, sufficient for holding nonzeros in each row of C */
1433   PetscCall(PetscFreeSpaceGet(Crmax, &free_space));
1434   current_space = free_space;
1435 
1436   PetscCall(PetscMalloc3(nrecv, &buf_ri_k, nrecv, &nextrow, nrecv, &nextci));
1437   for (k = 0; k < nrecv; k++) {
1438     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
1439     nrows       = *buf_ri_k[k];
1440     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
1441     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
1442   }
1443 
1444   MatPreallocateBegin(comm, pn, an, dnz, onz);
1445   PetscCall(PetscLLCondensedCreate(Crmax, aN, &lnk, &lnkbt));
1446   for (i = 0; i < pn; i++) { /* for each local row of C */
1447     /* add C_loc into C */
1448     nzi  = c_loc->i[i + 1] - c_loc->i[i];
1449     Jptr = c_loc->j + c_loc->i[i];
1450     PetscCall(PetscLLCondensedAddSorted(nzi, Jptr, lnk, lnkbt));
1451 
1452     /* add received col data into lnk */
1453     for (k = 0; k < nrecv; k++) { /* k-th received message */
1454       if (i == *nextrow[k]) {     /* i-th row */
1455         nzi  = *(nextci[k] + 1) - *nextci[k];
1456         Jptr = buf_rj[k] + *nextci[k];
1457         PetscCall(PetscLLCondensedAddSorted(nzi, Jptr, lnk, lnkbt));
1458         nextrow[k]++;
1459         nextci[k]++;
1460       }
1461     }
1462 
1463     /* add missing diagonal entry */
1464     if (C->force_diagonals) {
1465       k = i + owners[rank]; /* column index */
1466       PetscCall(PetscLLCondensedAddSorted(1, &k, lnk, lnkbt));
1467     }
1468 
1469     nzi = lnk[0];
1470 
1471     /* copy data into free space, then initialize lnk */
1472     PetscCall(PetscLLCondensedClean(aN, nzi, current_space->array, lnk, lnkbt));
1473     PetscCall(MatPreallocateSet(i + owners[rank], nzi, current_space->array, dnz, onz));
1474   }
1475   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));
1476   PetscCall(PetscLLDestroy(lnk, lnkbt));
1477   PetscCall(PetscFreeSpaceDestroy(free_space));
1478 
1479   /* local sizes and preallocation */
1480   PetscCall(MatSetSizes(C, pn, an, PETSC_DETERMINE, PETSC_DETERMINE));
1481   PetscCall(PetscLayoutSetBlockSize(C->rmap, P->cmap->bs));
1482   PetscCall(PetscLayoutSetBlockSize(C->cmap, A->cmap->bs));
1483   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
1484   MatPreallocateEnd(dnz, onz);
1485 
1486   /* add C_loc and C_oth to C */
1487   PetscCall(MatGetOwnershipRange(C, &rstart, NULL));
1488   for (i = 0; i < pn; i++) {
1489     ncols = c_loc->i[i + 1] - c_loc->i[i];
1490     cols  = c_loc->j + c_loc->i[i];
1491     row   = rstart + i;
1492     PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, ncols, (const PetscInt *)cols, NULL, INSERT_VALUES));
1493 
1494     if (C->force_diagonals) PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, 1, (const PetscInt *)&row, NULL, INSERT_VALUES));
1495   }
1496   for (i = 0; i < con; i++) {
1497     ncols = c_oth->i[i + 1] - c_oth->i[i];
1498     cols  = c_oth->j + c_oth->i[i];
1499     row   = prmap[i];
1500     PetscCall(MatSetValues(C, 1, (const PetscInt *)&row, ncols, (const PetscInt *)cols, NULL, INSERT_VALUES));
1501   }
1502   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1503   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1504   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
1505 
1506   /* members in merge */
1507   PetscCall(PetscFree(id_r));
1508   PetscCall(PetscFree(len_r));
1509   PetscCall(PetscFree(buf_ri[0]));
1510   PetscCall(PetscFree(buf_ri));
1511   PetscCall(PetscFree(buf_rj[0]));
1512   PetscCall(PetscFree(buf_rj));
1513   PetscCall(PetscLayoutDestroy(&rowmap));
1514 
1515   /* attach the supporting struct to C for reuse */
1516   C->product->data    = ptap;
1517   C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
1518   PetscFunctionReturn(PETSC_SUCCESS);
1519 }
1520 
MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat P,Mat A,Mat C)1521 PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_nonscalable(Mat P, Mat A, Mat C)
1522 {
1523   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data;
1524   Mat_SeqAIJ          *c_seq;
1525   MatProductCtx_APMPI *ptap;
1526   Mat                  A_loc, C_loc, C_oth;
1527   PetscInt             i, rstart, rend, cm, ncols, row;
1528   const PetscInt      *cols;
1529   const PetscScalar   *vals;
1530 
1531   PetscFunctionBegin;
1532   MatCheckProduct(C, 3);
1533   ptap = (MatProductCtx_APMPI *)C->product->data;
1534   PetscCheck(ptap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtAP cannot be computed. Missing data");
1535   PetscCheck(ptap->A_loc, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");
1536   PetscCall(MatZeroEntries(C));
1537 
1538   /* These matrices are obtained in MatTransposeMatMultSymbolic() */
1539   /* 1) get R = Pd^T, Ro = Po^T */
1540   PetscCall(MatTransposeSetPrecursor(p->A, ptap->Rd));
1541   PetscCall(MatTranspose(p->A, MAT_REUSE_MATRIX, &ptap->Rd));
1542   PetscCall(MatTransposeSetPrecursor(p->B, ptap->Ro));
1543   PetscCall(MatTranspose(p->B, MAT_REUSE_MATRIX, &ptap->Ro));
1544 
1545   /* 2) compute numeric A_loc */
1546   PetscCall(MatMPIAIJGetLocalMat(A, MAT_REUSE_MATRIX, &ptap->A_loc));
1547 
1548   /* 3) C_loc = Rd*A_loc, C_oth = Ro*A_loc */
1549   A_loc = ptap->A_loc;
1550   PetscCall(ptap->C_loc->ops->matmultnumeric(ptap->Rd, A_loc, ptap->C_loc));
1551   PetscCall(ptap->C_oth->ops->matmultnumeric(ptap->Ro, A_loc, ptap->C_oth));
1552   C_loc = ptap->C_loc;
1553   C_oth = ptap->C_oth;
1554 
1555   /* add C_loc and C_oth to C */
1556   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
1557 
1558   /* C_loc -> C */
1559   cm    = C_loc->rmap->N;
1560   c_seq = (Mat_SeqAIJ *)C_loc->data;
1561   cols  = c_seq->j;
1562   vals  = c_seq->a;
1563   for (i = 0; i < cm; i++) {
1564     ncols = c_seq->i[i + 1] - c_seq->i[i];
1565     row   = rstart + i;
1566     PetscCall(MatSetValues(C, 1, &row, ncols, cols, vals, ADD_VALUES));
1567     cols += ncols;
1568     vals += ncols;
1569   }
1570 
1571   /* Co -> C, off-processor part */
1572   cm    = C_oth->rmap->N;
1573   c_seq = (Mat_SeqAIJ *)C_oth->data;
1574   cols  = c_seq->j;
1575   vals  = c_seq->a;
1576   for (i = 0; i < cm; i++) {
1577     ncols = c_seq->i[i + 1] - c_seq->i[i];
1578     row   = p->garray[i];
1579     PetscCall(MatSetValues(C, 1, &row, ncols, cols, vals, ADD_VALUES));
1580     cols += ncols;
1581     vals += ncols;
1582   }
1583   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1584   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1585   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
1586   PetscFunctionReturn(PETSC_SUCCESS);
1587 }
1588 
MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ(Mat P,Mat A,Mat C)1589 PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ(Mat P, Mat A, Mat C)
1590 {
1591   MatMergeSeqsToMPI   *merge;
1592   Mat_MPIAIJ          *p  = (Mat_MPIAIJ *)P->data;
1593   Mat_SeqAIJ          *pd = (Mat_SeqAIJ *)p->A->data, *po = (Mat_SeqAIJ *)p->B->data;
1594   MatProductCtx_APMPI *ap;
1595   PetscInt            *adj;
1596   PetscInt             i, j, k, anz, pnz, row, *cj, nexta;
1597   MatScalar           *ada, *ca, valtmp;
1598   PetscInt             am = A->rmap->n, cm = C->rmap->n, pon = (p->B)->cmap->n;
1599   MPI_Comm             comm;
1600   PetscMPIInt          size, rank, taga, *len_s, proc;
1601   PetscInt            *owners, nrows, **buf_ri_k, **nextrow, **nextci;
1602   PetscInt           **buf_ri, **buf_rj;
1603   PetscInt             cnz = 0, *bj_i, *bi, *bj, bnz, nextcj; /* bi,bj,ba: local array of C(mpi mat) */
1604   MPI_Request         *s_waits, *r_waits;
1605   MPI_Status          *status;
1606   MatScalar          **abuf_r, *ba_i, *pA, *coa, *ba;
1607   const PetscScalar   *dummy;
1608   PetscInt            *ai, *aj, *coi, *coj, *poJ, *pdJ;
1609   Mat                  A_loc;
1610   Mat_SeqAIJ          *a_loc;
1611 
1612   PetscFunctionBegin;
1613   MatCheckProduct(C, 3);
1614   ap = (MatProductCtx_APMPI *)C->product->data;
1615   PetscCheck(ap, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be computed. Missing data");
1616   PetscCheck(ap->A_loc, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "PtA cannot be reused. Do not call MatProductClear()");
1617   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
1618   PetscCallMPI(MPI_Comm_size(comm, &size));
1619   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1620 
1621   merge = ap->merge;
1622 
1623   /* 2) compute numeric C_seq = P_loc^T*A_loc */
1624   /* get data from symbolic products */
1625   coi = merge->coi;
1626   coj = merge->coj;
1627   PetscCall(PetscCalloc1(coi[pon], &coa));
1628   bi     = merge->bi;
1629   bj     = merge->bj;
1630   owners = merge->rowmap->range;
1631   PetscCall(PetscCalloc1(bi[cm], &ba));
1632 
1633   /* get A_loc by taking all local rows of A */
1634   A_loc = ap->A_loc;
1635   PetscCall(MatMPIAIJGetLocalMat(A, MAT_REUSE_MATRIX, &A_loc));
1636   a_loc = (Mat_SeqAIJ *)A_loc->data;
1637   ai    = a_loc->i;
1638   aj    = a_loc->j;
1639 
1640   /* trigger copy to CPU */
1641   PetscCall(MatSeqAIJGetArrayRead(p->A, &dummy));
1642   PetscCall(MatSeqAIJRestoreArrayRead(p->A, &dummy));
1643   PetscCall(MatSeqAIJGetArrayRead(p->B, &dummy));
1644   PetscCall(MatSeqAIJRestoreArrayRead(p->B, &dummy));
1645   for (i = 0; i < am; i++) {
1646     anz = ai[i + 1] - ai[i];
1647     adj = aj + ai[i];
1648     ada = a_loc->a + ai[i];
1649 
1650     /* 2-b) Compute Cseq = P_loc[i,:]^T*A[i,:] using outer product */
1651     /* put the value into Co=(p->B)^T*A (off-diagonal part, send to others) */
1652     pnz = po->i[i + 1] - po->i[i];
1653     poJ = po->j + po->i[i];
1654     pA  = po->a + po->i[i];
1655     for (j = 0; j < pnz; j++) {
1656       row = poJ[j];
1657       cj  = coj + coi[row];
1658       ca  = coa + coi[row];
1659       /* perform sparse axpy */
1660       nexta  = 0;
1661       valtmp = pA[j];
1662       for (k = 0; nexta < anz; k++) {
1663         if (cj[k] == adj[nexta]) {
1664           ca[k] += valtmp * ada[nexta];
1665           nexta++;
1666         }
1667       }
1668       PetscCall(PetscLogFlops(2.0 * anz));
1669     }
1670 
1671     /* put the value into Cd (diagonal part) */
1672     pnz = pd->i[i + 1] - pd->i[i];
1673     pdJ = pd->j + pd->i[i];
1674     pA  = pd->a + pd->i[i];
1675     for (j = 0; j < pnz; j++) {
1676       row = pdJ[j];
1677       cj  = bj + bi[row];
1678       ca  = ba + bi[row];
1679       /* perform sparse axpy */
1680       nexta  = 0;
1681       valtmp = pA[j];
1682       for (k = 0; nexta < anz; k++) {
1683         if (cj[k] == adj[nexta]) {
1684           ca[k] += valtmp * ada[nexta];
1685           nexta++;
1686         }
1687       }
1688       PetscCall(PetscLogFlops(2.0 * anz));
1689     }
1690   }
1691 
1692   /* 3) send and recv matrix values coa */
1693   buf_ri = merge->buf_ri;
1694   buf_rj = merge->buf_rj;
1695   len_s  = merge->len_s;
1696   PetscCall(PetscCommGetNewTag(comm, &taga));
1697   PetscCall(PetscPostIrecvScalar(comm, taga, merge->nrecv, merge->id_r, merge->len_r, &abuf_r, &r_waits));
1698 
1699   PetscCall(PetscMalloc2(merge->nsend, &s_waits, size, &status));
1700   for (proc = 0, k = 0; proc < size; proc++) {
1701     if (!len_s[proc]) continue;
1702     i = merge->owners_co[proc];
1703     PetscCallMPI(MPIU_Isend(coa + coi[i], len_s[proc], MPIU_MATSCALAR, proc, taga, comm, s_waits + k));
1704     k++;
1705   }
1706   if (merge->nrecv) PetscCallMPI(MPI_Waitall(merge->nrecv, r_waits, status));
1707   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, s_waits, status));
1708 
1709   PetscCall(PetscFree2(s_waits, status));
1710   PetscCall(PetscFree(r_waits));
1711   PetscCall(PetscFree(coa));
1712 
1713   /* 4) insert local Cseq and received values into Cmpi */
1714   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextci));
1715   for (k = 0; k < merge->nrecv; k++) {
1716     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
1717     nrows       = *buf_ri_k[k];
1718     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
1719     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th recved i-structure  */
1720   }
1721 
1722   for (i = 0; i < cm; i++) {
1723     row  = owners[rank] + i; /* global row index of C_seq */
1724     bj_i = bj + bi[i];       /* col indices of the i-th row of C */
1725     ba_i = ba + bi[i];
1726     bnz  = bi[i + 1] - bi[i];
1727     /* add received vals into ba */
1728     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
1729       /* i-th row */
1730       if (i == *nextrow[k]) {
1731         cnz    = *(nextci[k] + 1) - *nextci[k];
1732         cj     = buf_rj[k] + *nextci[k];
1733         ca     = abuf_r[k] + *nextci[k];
1734         nextcj = 0;
1735         for (j = 0; nextcj < cnz; j++) {
1736           if (bj_i[j] == cj[nextcj]) { /* bcol == ccol */
1737             ba_i[j] += ca[nextcj++];
1738           }
1739         }
1740         nextrow[k]++;
1741         nextci[k]++;
1742         PetscCall(PetscLogFlops(2.0 * cnz));
1743       }
1744     }
1745     PetscCall(MatSetValues(C, 1, &row, bnz, bj_i, ba_i, INSERT_VALUES));
1746   }
1747   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1748   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1749 
1750   PetscCall(PetscFree(ba));
1751   PetscCall(PetscFree(abuf_r[0]));
1752   PetscCall(PetscFree(abuf_r));
1753   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));
1754   PetscFunctionReturn(PETSC_SUCCESS);
1755 }
1756 
MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ(Mat P,Mat A,PetscReal fill,Mat C)1757 PetscErrorCode MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ(Mat P, Mat A, PetscReal fill, Mat C)
1758 {
1759   Mat                  A_loc;
1760   MatProductCtx_APMPI *ap;
1761   PetscFreeSpaceList   free_space = NULL, current_space = NULL;
1762   Mat_MPIAIJ          *p = (Mat_MPIAIJ *)P->data, *a = (Mat_MPIAIJ *)A->data;
1763   PetscInt            *pdti, *pdtj, *poti, *potj, *ptJ;
1764   PetscInt             nnz;
1765   PetscInt            *lnk, *owners_co, *coi, *coj, i, k, pnz, row;
1766   PetscInt             am = A->rmap->n, pn = P->cmap->n;
1767   MPI_Comm             comm;
1768   PetscMPIInt          size, rank, tagi, tagj, *len_si, *len_s, *len_ri, proc;
1769   PetscInt           **buf_rj, **buf_ri, **buf_ri_k;
1770   PetscInt             len, *dnz, *onz, *owners;
1771   PetscInt             nzi, *bi, *bj;
1772   PetscInt             nrows, *buf_s, *buf_si, *buf_si_i, **nextrow, **nextci;
1773   MPI_Request         *swaits, *rwaits;
1774   MPI_Status          *sstatus, rstatus;
1775   MatMergeSeqsToMPI   *merge;
1776   PetscInt            *ai, *aj, *Jptr, anz, *prmap = p->garray, pon, nspacedouble = 0, j;
1777   PetscReal            afill  = 1.0, afill_tmp;
1778   PetscInt             rstart = P->cmap->rstart, rmax, Armax;
1779   Mat_SeqAIJ          *a_loc;
1780   PetscHMapI           ta;
1781   MatType              mtype;
1782 
1783   PetscFunctionBegin;
1784   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
1785   /* check if matrix local sizes are compatible */
1786   PetscCheck(A->rmap->rstart == P->rmap->rstart && A->rmap->rend == P->rmap->rend, comm, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A (%" PetscInt_FMT ", %" PetscInt_FMT ") != P (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->rstart,
1787              A->rmap->rend, P->rmap->rstart, P->rmap->rend);
1788 
1789   PetscCallMPI(MPI_Comm_size(comm, &size));
1790   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1791 
1792   /* create struct MatProductCtx_APMPI and attached it to C later */
1793   PetscCall(PetscNew(&ap));
1794 
1795   /* get A_loc by taking all local rows of A */
1796   PetscCall(MatMPIAIJGetLocalMat(A, MAT_INITIAL_MATRIX, &A_loc));
1797 
1798   ap->A_loc = A_loc;
1799   a_loc     = (Mat_SeqAIJ *)A_loc->data;
1800   ai        = a_loc->i;
1801   aj        = a_loc->j;
1802 
1803   /* determine symbolic Co=(p->B)^T*A - send to others */
1804   PetscCall(MatGetSymbolicTranspose_SeqAIJ(p->A, &pdti, &pdtj));
1805   PetscCall(MatGetSymbolicTranspose_SeqAIJ(p->B, &poti, &potj));
1806   pon = (p->B)->cmap->n; /* total num of rows to be sent to other processors
1807                          >= (num of nonzero rows of C_seq) - pn */
1808   PetscCall(PetscMalloc1(pon + 1, &coi));
1809   coi[0] = 0;
1810 
1811   /* set initial free space to be fill*(nnz(p->B) + nnz(A)) */
1812   nnz = PetscRealIntMultTruncate(fill, PetscIntSumTruncate(poti[pon], ai[am]));
1813   PetscCall(PetscFreeSpaceGet(nnz, &free_space));
1814   current_space = free_space;
1815 
1816   /* create and initialize a linked list */
1817   PetscCall(PetscHMapICreateWithSize(A->cmap->n + a->B->cmap->N, &ta));
1818   MatRowMergeMax_SeqAIJ(a_loc, am, ta);
1819   PetscCall(PetscHMapIGetSize(ta, &Armax));
1820 
1821   PetscCall(PetscLLCondensedCreate_Scalable(Armax, &lnk));
1822 
1823   for (i = 0; i < pon; i++) {
1824     pnz = poti[i + 1] - poti[i];
1825     ptJ = potj + poti[i];
1826     for (j = 0; j < pnz; j++) {
1827       row  = ptJ[j]; /* row of A_loc == col of Pot */
1828       anz  = ai[row + 1] - ai[row];
1829       Jptr = aj + ai[row];
1830       /* add non-zero cols of AP into the sorted linked list lnk */
1831       PetscCall(PetscLLCondensedAddSorted_Scalable(anz, Jptr, lnk));
1832     }
1833     nnz = lnk[0];
1834 
1835     /* If free space is not available, double the total space in the list */
1836     if (current_space->local_remaining < nnz) {
1837       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(nnz, current_space->total_array_size), &current_space));
1838       nspacedouble++;
1839     }
1840 
1841     /* Copy data into free space, and zero out denserows */
1842     PetscCall(PetscLLCondensedClean_Scalable(nnz, current_space->array, lnk));
1843 
1844     current_space->array += nnz;
1845     current_space->local_used += nnz;
1846     current_space->local_remaining -= nnz;
1847 
1848     coi[i + 1] = coi[i] + nnz;
1849   }
1850 
1851   PetscCall(PetscMalloc1(coi[pon], &coj));
1852   PetscCall(PetscFreeSpaceContiguous(&free_space, coj));
1853   PetscCall(PetscLLCondensedDestroy_Scalable(lnk)); /* must destroy to get a new one for C */
1854 
1855   afill_tmp = (PetscReal)coi[pon] / (poti[pon] + ai[am] + 1);
1856   if (afill_tmp > afill) afill = afill_tmp;
1857 
1858   /* send j-array (coj) of Co to other processors */
1859   /* determine row ownership */
1860   PetscCall(PetscNew(&merge));
1861   PetscCall(PetscLayoutCreate(comm, &merge->rowmap));
1862 
1863   merge->rowmap->n  = pn;
1864   merge->rowmap->bs = 1;
1865 
1866   PetscCall(PetscLayoutSetUp(merge->rowmap));
1867   owners = merge->rowmap->range;
1868 
1869   /* determine the number of messages to send, their lengths */
1870   PetscCall(PetscCalloc1(size, &len_si));
1871   PetscCall(PetscCalloc1(size, &merge->len_s));
1872 
1873   len_s        = merge->len_s;
1874   merge->nsend = 0;
1875 
1876   PetscCall(PetscMalloc1(size + 1, &owners_co));
1877 
1878   proc = 0;
1879   for (i = 0; i < pon; i++) {
1880     while (prmap[i] >= owners[proc + 1]) proc++;
1881     len_si[proc]++; /* num of rows in Co to be sent to [proc] */
1882     len_s[proc] += coi[i + 1] - coi[i];
1883   }
1884 
1885   len          = 0; /* max length of buf_si[] */
1886   owners_co[0] = 0;
1887   for (proc = 0; proc < size; proc++) {
1888     owners_co[proc + 1] = owners_co[proc] + len_si[proc];
1889     if (len_s[proc]) {
1890       merge->nsend++;
1891       len_si[proc] = 2 * (len_si[proc] + 1);
1892       len += len_si[proc];
1893     }
1894   }
1895 
1896   /* determine the number and length of messages to receive for coi and coj  */
1897   PetscCall(PetscGatherNumberOfMessages(comm, NULL, len_s, &merge->nrecv));
1898   PetscCall(PetscGatherMessageLengths2(comm, merge->nsend, merge->nrecv, len_s, len_si, &merge->id_r, &merge->len_r, &len_ri));
1899 
1900   /* post the Irecv and Isend of coj */
1901   PetscCall(PetscCommGetNewTag(comm, &tagj));
1902   PetscCall(PetscPostIrecvInt(comm, tagj, merge->nrecv, merge->id_r, merge->len_r, &buf_rj, &rwaits));
1903   PetscCall(PetscMalloc1(merge->nsend, &swaits));
1904   for (proc = 0, k = 0; proc < size; proc++) {
1905     if (!len_s[proc]) continue;
1906     i = owners_co[proc];
1907     PetscCallMPI(MPIU_Isend(coj + coi[i], len_s[proc], MPIU_INT, proc, tagj, comm, swaits + k));
1908     k++;
1909   }
1910 
1911   /* receives and sends of coj are complete */
1912   PetscCall(PetscMalloc1(size, &sstatus));
1913   for (i = 0; i < merge->nrecv; i++) {
1914     PETSC_UNUSED PetscMPIInt icompleted;
1915     PetscCallMPI(MPI_Waitany(merge->nrecv, rwaits, &icompleted, &rstatus));
1916   }
1917   PetscCall(PetscFree(rwaits));
1918   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, swaits, sstatus));
1919 
1920   /* add received column indices into table to update Armax */
1921   /* Armax can be as large as aN if a P[row,:] is dense, see src/ksp/ksp/tutorials/ex56.c! */
1922   for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
1923     Jptr = buf_rj[k];
1924     for (j = 0; j < merge->len_r[k]; j++) PetscCall(PetscHMapISet(ta, *(Jptr + j) + 1, 1));
1925   }
1926   PetscCall(PetscHMapIGetSize(ta, &Armax));
1927 
1928   /* send and recv coi */
1929   PetscCall(PetscCommGetNewTag(comm, &tagi));
1930   PetscCall(PetscPostIrecvInt(comm, tagi, merge->nrecv, merge->id_r, len_ri, &buf_ri, &rwaits));
1931   PetscCall(PetscMalloc1(len, &buf_s));
1932   buf_si = buf_s; /* points to the beginning of k-th msg to be sent */
1933   for (proc = 0, k = 0; proc < size; proc++) {
1934     if (!len_s[proc]) continue;
1935     /* form outgoing message for i-structure:
1936          buf_si[0]:                 nrows to be sent
1937                [1:nrows]:           row index (global)
1938                [nrows+1:2*nrows+1]: i-structure index
1939     */
1940     nrows       = len_si[proc] / 2 - 1;
1941     buf_si_i    = buf_si + nrows + 1;
1942     buf_si[0]   = nrows;
1943     buf_si_i[0] = 0;
1944     nrows       = 0;
1945     for (i = owners_co[proc]; i < owners_co[proc + 1]; i++) {
1946       nzi                 = coi[i + 1] - coi[i];
1947       buf_si_i[nrows + 1] = buf_si_i[nrows] + nzi;   /* i-structure */
1948       buf_si[nrows + 1]   = prmap[i] - owners[proc]; /* local row index */
1949       nrows++;
1950     }
1951     PetscCallMPI(MPIU_Isend(buf_si, len_si[proc], MPIU_INT, proc, tagi, comm, swaits + k));
1952     k++;
1953     buf_si += len_si[proc];
1954   }
1955   i = merge->nrecv;
1956   while (i--) {
1957     PETSC_UNUSED PetscMPIInt icompleted;
1958     PetscCallMPI(MPI_Waitany(merge->nrecv, rwaits, &icompleted, &rstatus));
1959   }
1960   PetscCall(PetscFree(rwaits));
1961   if (merge->nsend) PetscCallMPI(MPI_Waitall(merge->nsend, swaits, sstatus));
1962   PetscCall(PetscFree(len_si));
1963   PetscCall(PetscFree(len_ri));
1964   PetscCall(PetscFree(swaits));
1965   PetscCall(PetscFree(sstatus));
1966   PetscCall(PetscFree(buf_s));
1967 
1968   /* compute the local portion of C (mpi mat) */
1969   /* allocate bi array and free space for accumulating nonzero column info */
1970   PetscCall(PetscMalloc1(pn + 1, &bi));
1971   bi[0] = 0;
1972 
1973   /* set initial free space to be fill*(nnz(P) + nnz(AP)) */
1974   nnz = PetscRealIntMultTruncate(fill, PetscIntSumTruncate(pdti[pn], PetscIntSumTruncate(poti[pon], ai[am])));
1975   PetscCall(PetscFreeSpaceGet(nnz, &free_space));
1976   current_space = free_space;
1977 
1978   PetscCall(PetscMalloc3(merge->nrecv, &buf_ri_k, merge->nrecv, &nextrow, merge->nrecv, &nextci));
1979   for (k = 0; k < merge->nrecv; k++) {
1980     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
1981     nrows       = *buf_ri_k[k];
1982     nextrow[k]  = buf_ri_k[k] + 1;           /* next row number of k-th recved i-structure */
1983     nextci[k]   = buf_ri_k[k] + (nrows + 1); /* points to the next i-structure of k-th received i-structure  */
1984   }
1985 
1986   PetscCall(PetscLLCondensedCreate_Scalable(Armax, &lnk));
1987   MatPreallocateBegin(comm, pn, A->cmap->n, dnz, onz);
1988   rmax = 0;
1989   for (i = 0; i < pn; i++) {
1990     /* add pdt[i,:]*AP into lnk */
1991     pnz = pdti[i + 1] - pdti[i];
1992     ptJ = pdtj + pdti[i];
1993     for (j = 0; j < pnz; j++) {
1994       row  = ptJ[j]; /* row of AP == col of Pt */
1995       anz  = ai[row + 1] - ai[row];
1996       Jptr = aj + ai[row];
1997       /* add non-zero cols of AP into the sorted linked list lnk */
1998       PetscCall(PetscLLCondensedAddSorted_Scalable(anz, Jptr, lnk));
1999     }
2000 
2001     /* add received col data into lnk */
2002     for (k = 0; k < merge->nrecv; k++) { /* k-th received message */
2003       if (i == *nextrow[k]) {            /* i-th row */
2004         nzi  = *(nextci[k] + 1) - *nextci[k];
2005         Jptr = buf_rj[k] + *nextci[k];
2006         PetscCall(PetscLLCondensedAddSorted_Scalable(nzi, Jptr, lnk));
2007         nextrow[k]++;
2008         nextci[k]++;
2009       }
2010     }
2011 
2012     /* add missing diagonal entry */
2013     if (C->force_diagonals) {
2014       k = i + owners[rank]; /* column index */
2015       PetscCall(PetscLLCondensedAddSorted_Scalable(1, &k, lnk));
2016     }
2017 
2018     nnz = lnk[0];
2019 
2020     /* if free space is not available, make more free space */
2021     if (current_space->local_remaining < nnz) {
2022       PetscCall(PetscFreeSpaceGet(PetscIntSumTruncate(nnz, current_space->total_array_size), &current_space));
2023       nspacedouble++;
2024     }
2025     /* copy data into free space, then initialize lnk */
2026     PetscCall(PetscLLCondensedClean_Scalable(nnz, current_space->array, lnk));
2027     PetscCall(MatPreallocateSet(i + owners[rank], nnz, current_space->array, dnz, onz));
2028 
2029     current_space->array += nnz;
2030     current_space->local_used += nnz;
2031     current_space->local_remaining -= nnz;
2032 
2033     bi[i + 1] = bi[i] + nnz;
2034     if (nnz > rmax) rmax = nnz;
2035   }
2036   PetscCall(PetscFree3(buf_ri_k, nextrow, nextci));
2037 
2038   PetscCall(PetscMalloc1(bi[pn], &bj));
2039   PetscCall(PetscFreeSpaceContiguous(&free_space, bj));
2040   afill_tmp = (PetscReal)bi[pn] / (pdti[pn] + poti[pon] + ai[am] + 1);
2041   if (afill_tmp > afill) afill = afill_tmp;
2042   PetscCall(PetscLLCondensedDestroy_Scalable(lnk));
2043   PetscCall(PetscHMapIDestroy(&ta));
2044   PetscCall(MatRestoreSymbolicTranspose_SeqAIJ(p->A, &pdti, &pdtj));
2045   PetscCall(MatRestoreSymbolicTranspose_SeqAIJ(p->B, &poti, &potj));
2046 
2047   /* create symbolic parallel matrix C - why cannot be assembled in Numeric part   */
2048   PetscCall(MatSetSizes(C, pn, A->cmap->n, PETSC_DETERMINE, PETSC_DETERMINE));
2049   PetscCall(MatSetBlockSizes(C, P->cmap->bs, A->cmap->bs));
2050   PetscCall(MatGetType(A, &mtype));
2051   PetscCall(MatSetType(C, mtype));
2052   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnz, 0, onz));
2053   MatPreallocateEnd(dnz, onz);
2054   PetscCall(MatSetBlockSize(C, 1));
2055   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
2056   for (i = 0; i < pn; i++) {
2057     row  = i + rstart;
2058     nnz  = bi[i + 1] - bi[i];
2059     Jptr = bj + bi[i];
2060     PetscCall(MatSetValues(C, 1, &row, nnz, Jptr, NULL, INSERT_VALUES));
2061   }
2062   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2063   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2064   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
2065   merge->bi        = bi;
2066   merge->bj        = bj;
2067   merge->coi       = coi;
2068   merge->coj       = coj;
2069   merge->buf_ri    = buf_ri;
2070   merge->buf_rj    = buf_rj;
2071   merge->owners_co = owners_co;
2072 
2073   /* attach the supporting struct to C for reuse */
2074   C->product->data    = ap;
2075   C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
2076   ap->merge           = merge;
2077 
2078   C->ops->mattransposemultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ;
2079 
2080 #if defined(PETSC_USE_INFO)
2081   if (bi[pn] != 0) {
2082     PetscCall(PetscInfo(C, "Reallocs %" PetscInt_FMT "; Fill ratio: given %g needed %g.\n", nspacedouble, (double)fill, (double)afill));
2083     PetscCall(PetscInfo(C, "Use MatTransposeMatMult(A,B,MatReuse,%g,&C) for best performance.\n", (double)afill));
2084   } else {
2085     PetscCall(PetscInfo(C, "Empty matrix product\n"));
2086   }
2087 #endif
2088   PetscFunctionReturn(PETSC_SUCCESS);
2089 }
2090 
MatProductSymbolic_AtB_MPIAIJ_MPIAIJ(Mat C)2091 static PetscErrorCode MatProductSymbolic_AtB_MPIAIJ_MPIAIJ(Mat C)
2092 {
2093   Mat_Product *product = C->product;
2094   Mat          A = product->A, B = product->B;
2095   PetscReal    fill = product->fill;
2096   PetscBool    flg;
2097 
2098   PetscFunctionBegin;
2099   /* scalable */
2100   PetscCall(PetscStrcmp(product->alg, "scalable", &flg));
2101   if (flg) {
2102     PetscCall(MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ(A, B, fill, C));
2103     goto next;
2104   }
2105 
2106   /* nonscalable */
2107   PetscCall(PetscStrcmp(product->alg, "nonscalable", &flg));
2108   if (flg) {
2109     PetscCall(MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(A, B, fill, C));
2110     goto next;
2111   }
2112 
2113   /* matmatmult */
2114   PetscCall(PetscStrcmp(product->alg, "at*b", &flg));
2115   if (flg) {
2116     Mat                  At;
2117     MatProductCtx_APMPI *ptap;
2118 
2119     PetscCall(MatTranspose(A, MAT_INITIAL_MATRIX, &At));
2120     PetscCall(MatMatMultSymbolic_MPIAIJ_MPIAIJ(At, B, fill, C));
2121     ptap = (MatProductCtx_APMPI *)C->product->data;
2122     if (ptap) {
2123       ptap->Pt            = At;
2124       C->product->destroy = MatProductCtxDestroy_MPIAIJ_PtAP;
2125     }
2126     C->ops->transposematmultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ_matmatmult;
2127     goto next;
2128   }
2129 
2130   /* backend general code */
2131   PetscCall(PetscStrcmp(product->alg, "backend", &flg));
2132   if (flg) {
2133     PetscCall(MatProductSymbolic_MPIAIJBACKEND(C));
2134     PetscFunctionReturn(PETSC_SUCCESS);
2135   }
2136 
2137   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "MatProduct type is not supported");
2138 
2139 next:
2140   C->ops->productnumeric = MatProductNumeric_AtB;
2141   PetscFunctionReturn(PETSC_SUCCESS);
2142 }
2143 
2144 /* Set options for MatMatMultxxx_MPIAIJ_MPIAIJ */
MatProductSetFromOptions_MPIAIJ_AB(Mat C)2145 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_AB(Mat C)
2146 {
2147   Mat_Product *product = C->product;
2148   Mat          A = product->A, B = product->B;
2149 #if defined(PETSC_HAVE_HYPRE)
2150   const char *algTypes[5] = {"scalable", "nonscalable", "seqmpi", "backend", "hypre"};
2151   PetscInt    nalg        = 5;
2152 #else
2153   const char *algTypes[4] = {
2154     "scalable",
2155     "nonscalable",
2156     "seqmpi",
2157     "backend",
2158   };
2159   PetscInt nalg = 4;
2160 #endif
2161   PetscInt  alg = 1; /* set nonscalable algorithm as default */
2162   PetscBool flg;
2163   MPI_Comm  comm;
2164 
2165   PetscFunctionBegin;
2166   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
2167 
2168   /* Set "nonscalable" as default algorithm */
2169   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2170   if (flg) {
2171     PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2172 
2173     /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2174     if (B->cmap->N > 100000) { /* may switch to scalable algorithm as default */
2175       MatInfo   Ainfo, Binfo;
2176       PetscInt  nz_local;
2177       PetscBool alg_scalable_loc = PETSC_FALSE, alg_scalable;
2178 
2179       PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2180       PetscCall(MatGetInfo(B, MAT_LOCAL, &Binfo));
2181       nz_local = (PetscInt)(Ainfo.nz_allocated + Binfo.nz_allocated);
2182 
2183       if (B->cmap->N > product->fill * nz_local) alg_scalable_loc = PETSC_TRUE;
2184       PetscCallMPI(MPIU_Allreduce(&alg_scalable_loc, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));
2185 
2186       if (alg_scalable) {
2187         alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2188         PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2189         PetscCall(PetscInfo(B, "Use scalable algorithm, BN %" PetscInt_FMT ", fill*nz_allocated %g\n", B->cmap->N, (double)(product->fill * nz_local)));
2190       }
2191     }
2192   }
2193 
2194   /* Get runtime option */
2195   if (product->api_user) {
2196     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatMatMult", "Mat");
2197     PetscCall(PetscOptionsEList("-matmatmult_via", "Algorithmic approach", "MatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2198     PetscOptionsEnd();
2199   } else {
2200     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_AB", "Mat");
2201     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2202     PetscOptionsEnd();
2203   }
2204   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2205 
2206   C->ops->productsymbolic = MatProductSymbolic_AB_MPIAIJ_MPIAIJ;
2207   PetscFunctionReturn(PETSC_SUCCESS);
2208 }
2209 
MatProductSetFromOptions_MPIAIJ_ABt(Mat C)2210 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_ABt(Mat C)
2211 {
2212   PetscFunctionBegin;
2213   PetscCall(MatProductSetFromOptions_MPIAIJ_AB(C));
2214   C->ops->productsymbolic = MatProductSymbolic_ABt_MPIAIJ_MPIAIJ;
2215   PetscFunctionReturn(PETSC_SUCCESS);
2216 }
2217 
2218 /* Set options for MatTransposeMatMultXXX_MPIAIJ_MPIAIJ */
MatProductSetFromOptions_MPIAIJ_AtB(Mat C)2219 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_AtB(Mat C)
2220 {
2221   Mat_Product *product = C->product;
2222   Mat          A = product->A, B = product->B;
2223   const char  *algTypes[4] = {"scalable", "nonscalable", "at*b", "backend"};
2224   PetscInt     nalg        = 4;
2225   PetscInt     alg         = 1; /* set default algorithm  */
2226   PetscBool    flg;
2227   MPI_Comm     comm;
2228 
2229   PetscFunctionBegin;
2230   /* Check matrix local sizes */
2231   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
2232   PetscCheck(A->rmap->rstart == B->rmap->rstart && A->rmap->rend == B->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A (%" PetscInt_FMT ", %" PetscInt_FMT ") != B (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2233              A->rmap->rstart, A->rmap->rend, B->rmap->rstart, B->rmap->rend);
2234 
2235   /* Set default algorithm */
2236   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2237   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2238 
2239   /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2240   if (alg && B->cmap->N > 100000) { /* may switch to scalable algorithm as default */
2241     MatInfo   Ainfo, Binfo;
2242     PetscInt  nz_local;
2243     PetscBool alg_scalable_loc = PETSC_FALSE, alg_scalable;
2244 
2245     PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2246     PetscCall(MatGetInfo(B, MAT_LOCAL, &Binfo));
2247     nz_local = (PetscInt)(Ainfo.nz_allocated + Binfo.nz_allocated);
2248 
2249     if (B->cmap->N > product->fill * nz_local) alg_scalable_loc = PETSC_TRUE;
2250     PetscCallMPI(MPIU_Allreduce(&alg_scalable_loc, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));
2251 
2252     if (alg_scalable) {
2253       alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2254       PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2255       PetscCall(PetscInfo(B, "Use scalable algorithm, BN %" PetscInt_FMT ", fill*nz_allocated %g\n", B->cmap->N, (double)(product->fill * nz_local)));
2256     }
2257   }
2258 
2259   /* Get runtime option */
2260   if (product->api_user) {
2261     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatTransposeMatMult", "Mat");
2262     PetscCall(PetscOptionsEList("-mattransposematmult_via", "Algorithmic approach", "MatTransposeMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2263     PetscOptionsEnd();
2264   } else {
2265     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_AtB", "Mat");
2266     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatTransposeMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2267     PetscOptionsEnd();
2268   }
2269   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2270 
2271   C->ops->productsymbolic = MatProductSymbolic_AtB_MPIAIJ_MPIAIJ;
2272   PetscFunctionReturn(PETSC_SUCCESS);
2273 }
2274 
MatProductSetFromOptions_MPIAIJ_PtAP(Mat C)2275 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_PtAP(Mat C)
2276 {
2277   Mat_Product *product = C->product;
2278   Mat          A = product->A, P = product->B;
2279   MPI_Comm     comm;
2280   PetscBool    flg;
2281   PetscInt     alg = 1; /* set default algorithm */
2282 #if !defined(PETSC_HAVE_HYPRE)
2283   const char *algTypes[5] = {"scalable", "nonscalable", "allatonce", "allatonce_merged", "backend"};
2284   PetscInt    nalg        = 5;
2285 #else
2286   const char *algTypes[6] = {"scalable", "nonscalable", "allatonce", "allatonce_merged", "backend", "hypre"};
2287   PetscInt    nalg        = 6;
2288 #endif
2289   PetscInt pN = P->cmap->N;
2290 
2291   PetscFunctionBegin;
2292   /* Check matrix local sizes */
2293   PetscCall(PetscObjectGetComm((PetscObject)C, &comm));
2294   PetscCheck(A->rmap->rstart == P->rmap->rstart && A->rmap->rend == P->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, Arow (%" PetscInt_FMT ", %" PetscInt_FMT ") != Prow (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2295              A->rmap->rstart, A->rmap->rend, P->rmap->rstart, P->rmap->rend);
2296   PetscCheck(A->cmap->rstart == P->rmap->rstart && A->cmap->rend == P->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, Acol (%" PetscInt_FMT ", %" PetscInt_FMT ") != Prow (%" PetscInt_FMT ",%" PetscInt_FMT ")",
2297              A->cmap->rstart, A->cmap->rend, P->rmap->rstart, P->rmap->rend);
2298 
2299   /* Set "nonscalable" as default algorithm */
2300   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2301   if (flg) {
2302     PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2303 
2304     /* Set "scalable" as default if BN and local nonzeros of A and B are large */
2305     if (pN > 100000) {
2306       MatInfo   Ainfo, Pinfo;
2307       PetscInt  nz_local;
2308       PetscBool alg_scalable_loc = PETSC_FALSE, alg_scalable;
2309 
2310       PetscCall(MatGetInfo(A, MAT_LOCAL, &Ainfo));
2311       PetscCall(MatGetInfo(P, MAT_LOCAL, &Pinfo));
2312       nz_local = (PetscInt)(Ainfo.nz_allocated + Pinfo.nz_allocated);
2313 
2314       if (pN > product->fill * nz_local) alg_scalable_loc = PETSC_TRUE;
2315       PetscCallMPI(MPIU_Allreduce(&alg_scalable_loc, &alg_scalable, 1, MPI_C_BOOL, MPI_LOR, comm));
2316 
2317       if (alg_scalable) {
2318         alg = 0; /* scalable algorithm would 50% slower than nonscalable algorithm */
2319         PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2320       }
2321     }
2322   }
2323 
2324   /* Get runtime option */
2325   if (product->api_user) {
2326     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatPtAP", "Mat");
2327     PetscCall(PetscOptionsEList("-matptap_via", "Algorithmic approach", "MatPtAP", algTypes, nalg, algTypes[alg], &alg, &flg));
2328     PetscOptionsEnd();
2329   } else {
2330     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_PtAP", "Mat");
2331     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatPtAP", algTypes, nalg, algTypes[alg], &alg, &flg));
2332     PetscOptionsEnd();
2333   }
2334   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2335 
2336   C->ops->productsymbolic = MatProductSymbolic_PtAP_MPIAIJ_MPIAIJ;
2337   PetscFunctionReturn(PETSC_SUCCESS);
2338 }
2339 
MatProductSetFromOptions_MPIAIJ_RARt(Mat C)2340 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_RARt(Mat C)
2341 {
2342   Mat_Product *product = C->product;
2343   Mat          A = product->A, R = product->B;
2344 
2345   PetscFunctionBegin;
2346   /* Check matrix local sizes */
2347   PetscCheck(A->cmap->n == R->cmap->n && A->rmap->n == R->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrix local dimensions are incompatible, A local (%" PetscInt_FMT ", %" PetscInt_FMT "), R local (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->n,
2348              A->rmap->n, R->rmap->n, R->cmap->n);
2349 
2350   C->ops->productsymbolic = MatProductSymbolic_RARt_MPIAIJ_MPIAIJ;
2351   PetscFunctionReturn(PETSC_SUCCESS);
2352 }
2353 
2354 /*
2355  Set options for ABC = A*B*C = A*(B*C); ABC's algorithm must be chosen from AB's algorithm
2356 */
MatProductSetFromOptions_MPIAIJ_ABC(Mat C)2357 static PetscErrorCode MatProductSetFromOptions_MPIAIJ_ABC(Mat C)
2358 {
2359   Mat_Product *product     = C->product;
2360   PetscBool    flg         = PETSC_FALSE;
2361   PetscInt     alg         = 1; /* default algorithm */
2362   const char  *algTypes[3] = {"scalable", "nonscalable", "seqmpi"};
2363   PetscInt     nalg        = 3;
2364 
2365   PetscFunctionBegin;
2366   /* Set default algorithm */
2367   PetscCall(PetscStrcmp(C->product->alg, "default", &flg));
2368   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2369 
2370   /* Get runtime option */
2371   if (product->api_user) {
2372     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatMatMatMult", "Mat");
2373     PetscCall(PetscOptionsEList("-matmatmatmult_via", "Algorithmic approach", "MatMatMatMult", algTypes, nalg, algTypes[alg], &alg, &flg));
2374     PetscOptionsEnd();
2375   } else {
2376     PetscOptionsBegin(PetscObjectComm((PetscObject)C), ((PetscObject)C)->prefix, "MatProduct_ABC", "Mat");
2377     PetscCall(PetscOptionsEList("-mat_product_algorithm", "Algorithmic approach", "MatProduct_ABC", algTypes, nalg, algTypes[alg], &alg, &flg));
2378     PetscOptionsEnd();
2379   }
2380   if (flg) PetscCall(MatProductSetAlgorithm(C, algTypes[alg]));
2381 
2382   C->ops->matmatmultsymbolic = MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ;
2383   C->ops->productsymbolic    = MatProductSymbolic_ABC;
2384   PetscFunctionReturn(PETSC_SUCCESS);
2385 }
2386 
MatProductSetFromOptions_MPIAIJ(Mat C)2387 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_MPIAIJ(Mat C)
2388 {
2389   Mat_Product *product = C->product;
2390 
2391   PetscFunctionBegin;
2392   switch (product->type) {
2393   case MATPRODUCT_AB:
2394     PetscCall(MatProductSetFromOptions_MPIAIJ_AB(C));
2395     break;
2396   case MATPRODUCT_ABt:
2397     PetscCall(MatProductSetFromOptions_MPIAIJ_ABt(C));
2398     break;
2399   case MATPRODUCT_AtB:
2400     PetscCall(MatProductSetFromOptions_MPIAIJ_AtB(C));
2401     break;
2402   case MATPRODUCT_PtAP:
2403     PetscCall(MatProductSetFromOptions_MPIAIJ_PtAP(C));
2404     break;
2405   case MATPRODUCT_RARt:
2406     PetscCall(MatProductSetFromOptions_MPIAIJ_RARt(C));
2407     break;
2408   case MATPRODUCT_ABC:
2409     PetscCall(MatProductSetFromOptions_MPIAIJ_ABC(C));
2410     break;
2411   default:
2412     break;
2413   }
2414   PetscFunctionReturn(PETSC_SUCCESS);
2415 }
2416