xref: /petsc/src/mat/impls/aij/seq/matmatmult.c (revision dfd57a172ac9fa6c7b5fe6de6ab5df85cefc2996)
1 
2 /*
3   Defines matrix-matrix product routines for pairs of SeqAIJ matrices
4           C = A * B
5 */
6 
7 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
8 #include <../src/mat/utils/freespace.h>
9 #include <petscbt.h>
10 #include <petsc/private/isimpl.h>
11 #include <../src/mat/impls/dense/seq/dense.h>
12 
13 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
14 {
15   PetscErrorCode ierr;
16 
17   PetscFunctionBegin;
18   if (C->ops->matmultnumeric) {
19     if (C->ops->matmultnumeric == MatMatMultNumeric_SeqAIJ_SeqAIJ) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Recursive call");
20     ierr = (*C->ops->matmultnumeric)(A,B,C);CHKERRQ(ierr);
21   } else {
22     ierr = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted(A,B,C);CHKERRQ(ierr);
23   }
24   PetscFunctionReturn(0);
25 }
26 
27 /* Modified from MatCreateSeqAIJWithArrays() */
28 PETSC_INTERN PetscErrorCode MatSetSeqAIJWithArrays_private(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt i[],PetscInt j[],PetscScalar a[],MatType mtype,Mat mat)
29 {
30   PetscErrorCode ierr;
31   PetscInt       ii;
32   Mat_SeqAIJ     *aij;
33   PetscBool      isseqaij;
34 
35   PetscFunctionBegin;
36   if (m > 0 && i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
37   ierr = MatSetSizes(mat,m,n,m,n);CHKERRQ(ierr);
38 
39   if (!mtype) {
40     ierr = PetscObjectBaseTypeCompare((PetscObject)mat,MATSEQAIJ,&isseqaij);CHKERRQ(ierr);
41     if (!isseqaij) { ierr = MatSetType(mat,MATSEQAIJ);CHKERRQ(ierr); }
42   } else {
43     ierr = MatSetType(mat,mtype);CHKERRQ(ierr);
44   }
45   ierr = MatSeqAIJSetPreallocation_SeqAIJ(mat,MAT_SKIP_ALLOCATION,NULL);CHKERRQ(ierr);
46   aij  = (Mat_SeqAIJ*)(mat)->data;
47   ierr = PetscMalloc1(m,&aij->imax);CHKERRQ(ierr);
48   ierr = PetscMalloc1(m,&aij->ilen);CHKERRQ(ierr);
49 
50   aij->i            = i;
51   aij->j            = j;
52   aij->a            = a;
53   aij->singlemalloc = PETSC_FALSE;
54   aij->nonew        = -1; /*this indicates that inserting a new value in the matrix that generates a new nonzero is an error*/
55   aij->free_a       = PETSC_FALSE;
56   aij->free_ij      = PETSC_FALSE;
57 
58   for (ii=0; ii<m; ii++) {
59     aij->ilen[ii] = aij->imax[ii] = i[ii+1] - i[ii];
60   }
61 
62   PetscFunctionReturn(0);
63 }
64 
65 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat C)
66 {
67   PetscErrorCode      ierr;
68   Mat_Product         *product = C->product;
69   MatProductAlgorithm alg;
70   PetscBool           flg;
71 
72   PetscFunctionBegin;
73   if (product) {
74     alg = product->alg;
75   } else {
76     alg = "sorted";
77   }
78   /* sorted */
79   ierr = PetscStrcmp(alg,"sorted",&flg);CHKERRQ(ierr);
80   if (flg) {
81     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Sorted(A,B,fill,C);CHKERRQ(ierr);
82     PetscFunctionReturn(0);
83   }
84 
85   /* scalable */
86   ierr = PetscStrcmp(alg,"scalable",&flg);CHKERRQ(ierr);
87   if (flg) {
88     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable(A,B,fill,C);CHKERRQ(ierr);
89     PetscFunctionReturn(0);
90   }
91 
92   /* scalable_fast */
93   ierr = PetscStrcmp(alg,"scalable_fast",&flg);CHKERRQ(ierr);
94   if (flg) {
95     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable_fast(A,B,fill,C);CHKERRQ(ierr);
96     PetscFunctionReturn(0);
97   }
98 
99   /* heap */
100   ierr = PetscStrcmp(alg,"heap",&flg);CHKERRQ(ierr);
101   if (flg) {
102     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Heap(A,B,fill,C);CHKERRQ(ierr);
103     PetscFunctionReturn(0);
104   }
105 
106   /* btheap */
107   ierr = PetscStrcmp(alg,"btheap",&flg);CHKERRQ(ierr);
108   if (flg) {
109     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_BTHeap(A,B,fill,C);CHKERRQ(ierr);
110     PetscFunctionReturn(0);
111   }
112 
113   /* llcondensed */
114   ierr = PetscStrcmp(alg,"llcondensed",&flg);CHKERRQ(ierr);
115   if (flg) {
116     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed(A,B,fill,C);CHKERRQ(ierr);
117     PetscFunctionReturn(0);
118   }
119 
120   /* rowmerge */
121   ierr = PetscStrcmp(alg,"rowmerge",&flg);CHKERRQ(ierr);
122   if (flg) {
123     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_RowMerge(A,B,fill,C);CHKERRQ(ierr);
124     PetscFunctionReturn(0);
125   }
126 
127 #if defined(PETSC_HAVE_HYPRE)
128   ierr = PetscStrcmp(alg,"hypre",&flg);CHKERRQ(ierr);
129   if (flg) {
130     ierr = MatMatMultSymbolic_AIJ_AIJ_wHYPRE(A,B,fill,C);CHKERRQ(ierr);
131     PetscFunctionReturn(0);
132   }
133 #endif
134 
135   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Mat Product Algorithm is not supported");
136 }
137 
138 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed(Mat A,Mat B,PetscReal fill,Mat C)
139 {
140   PetscErrorCode     ierr;
141   Mat_SeqAIJ         *a =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
142   PetscInt           *ai=a->i,*bi=b->i,*ci,*cj;
143   PetscInt           am =A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
144   PetscReal          afill;
145   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,*lnk,ndouble=0,Crmax;
146   PetscTable         ta;
147   PetscBT            lnkbt;
148   PetscFreeSpaceList free_space=NULL,current_space=NULL;
149 
150   PetscFunctionBegin;
151   /* Get ci and cj */
152   /*---------------*/
153   /* Allocate ci array, arrays for fill computation and */
154   /* free space for accumulating nonzero column info */
155   ierr  = PetscMalloc1(am+2,&ci);CHKERRQ(ierr);
156   ci[0] = 0;
157 
158   /* create and initialize a linked list */
159   ierr = PetscTableCreate(bn,bn,&ta);CHKERRQ(ierr);
160   MatRowMergeMax_SeqAIJ(b,bm,ta);
161   ierr = PetscTableGetCount(ta,&Crmax);CHKERRQ(ierr);
162   ierr = PetscTableDestroy(&ta);CHKERRQ(ierr);
163 
164   ierr = PetscLLCondensedCreate(Crmax,bn,&lnk,&lnkbt);CHKERRQ(ierr);
165 
166   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
167   ierr = PetscFreeSpaceGet(PetscRealIntMultTruncate(fill,PetscIntSumTruncate(ai[am],bi[bm])),&free_space);CHKERRQ(ierr);
168 
169   current_space = free_space;
170 
171   /* Determine ci and cj */
172   for (i=0; i<am; i++) {
173     anzi = ai[i+1] - ai[i];
174     aj   = a->j + ai[i];
175     for (j=0; j<anzi; j++) {
176       brow = aj[j];
177       bnzj = bi[brow+1] - bi[brow];
178       bj   = b->j + bi[brow];
179       /* add non-zero cols of B into the sorted linked list lnk */
180       ierr = PetscLLCondensedAddSorted(bnzj,bj,lnk,lnkbt);CHKERRQ(ierr);
181     }
182     /* add possible missing diagonal entry */
183     if (C->force_diagonals) {
184       ierr = PetscLLCondensedAddSorted(1,&i,lnk,lnkbt);CHKERRQ(ierr);
185     }
186     cnzi = lnk[0];
187 
188     /* If free space is not available, make more free space */
189     /* Double the amount of total space in the list */
190     if (current_space->local_remaining<cnzi) {
191       ierr = PetscFreeSpaceGet(PetscIntSumTruncate(cnzi,current_space->total_array_size),&current_space);CHKERRQ(ierr);
192       ndouble++;
193     }
194 
195     /* Copy data into free space, then initialize lnk */
196     ierr = PetscLLCondensedClean(bn,cnzi,current_space->array,lnk,lnkbt);CHKERRQ(ierr);
197 
198     current_space->array           += cnzi;
199     current_space->local_used      += cnzi;
200     current_space->local_remaining -= cnzi;
201 
202     ci[i+1] = ci[i] + cnzi;
203   }
204 
205   /* Column indices are in the list of free space */
206   /* Allocate space for cj, initialize cj, and */
207   /* destroy list of free space and other temporary array(s) */
208   ierr = PetscMalloc1(ci[am]+1,&cj);CHKERRQ(ierr);
209   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
210   ierr = PetscLLCondensedDestroy(lnk,lnkbt);CHKERRQ(ierr);
211 
212   /* put together the new symbolic matrix */
213   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
214   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
215 
216   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
217   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
218   c          = (Mat_SeqAIJ*)(C->data);
219   c->free_a  = PETSC_FALSE;
220   c->free_ij = PETSC_TRUE;
221   c->nonew   = 0;
222 
223   /* fast, needs non-scalable O(bn) array 'abdense' */
224   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted;
225 
226   /* set MatInfo */
227   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
228   if (afill < 1.0) afill = 1.0;
229   c->maxnz                  = ci[am];
230   c->nz                     = ci[am];
231   C->info.mallocs           = ndouble;
232   C->info.fill_ratio_given  = fill;
233   C->info.fill_ratio_needed = afill;
234 
235 #if defined(PETSC_USE_INFO)
236   if (ci[am]) {
237     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
238     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
239   } else {
240     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
241   }
242 #endif
243   PetscFunctionReturn(0);
244 }
245 
246 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted(Mat A,Mat B,Mat C)
247 {
248   PetscErrorCode    ierr;
249   PetscLogDouble    flops=0.0;
250   Mat_SeqAIJ        *a   = (Mat_SeqAIJ*)A->data;
251   Mat_SeqAIJ        *b   = (Mat_SeqAIJ*)B->data;
252   Mat_SeqAIJ        *c   = (Mat_SeqAIJ*)C->data;
253   PetscInt          *ai  =a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bjj,*ci=c->i,*cj=c->j;
254   PetscInt          am   =A->rmap->n,cm=C->rmap->n;
255   PetscInt          i,j,k,anzi,bnzi,cnzi,brow;
256   PetscScalar       *ca,valtmp;
257   PetscScalar       *ab_dense;
258   PetscContainer    cab_dense;
259   const PetscScalar *aa,*ba,*baj;
260 
261   PetscFunctionBegin;
262   ierr = MatSeqAIJGetArrayRead(A,&aa);CHKERRQ(ierr);
263   ierr = MatSeqAIJGetArrayRead(B,&ba);CHKERRQ(ierr);
264   if (!c->a) { /* first call of MatMatMultNumeric_SeqAIJ_SeqAIJ, allocate ca and matmult_abdense */
265     ierr      = PetscMalloc1(ci[cm]+1,&ca);CHKERRQ(ierr);
266     c->a      = ca;
267     c->free_a = PETSC_TRUE;
268   } else ca = c->a;
269 
270   /* TODO this should be done in the symbolic phase */
271   /* However, this function is so heavily used (sometimes in an hidden way through multnumeric function pointers
272      that is hard to eradicate) */
273   ierr = PetscObjectQuery((PetscObject)C,"__PETSc__ab_dense",(PetscObject*)&cab_dense);CHKERRQ(ierr);
274   if (!cab_dense) {
275     ierr = PetscMalloc1(B->cmap->N,&ab_dense);CHKERRQ(ierr);
276     ierr = PetscContainerCreate(PETSC_COMM_SELF,&cab_dense);CHKERRQ(ierr);
277     ierr = PetscContainerSetPointer(cab_dense,ab_dense);CHKERRQ(ierr);
278     ierr = PetscContainerSetUserDestroy(cab_dense,PetscContainerUserDestroyDefault);CHKERRQ(ierr);
279     ierr = PetscObjectCompose((PetscObject)C,"__PETSc__ab_dense",(PetscObject)cab_dense);CHKERRQ(ierr);
280     ierr = PetscObjectDereference((PetscObject)cab_dense);CHKERRQ(ierr);
281   }
282   ierr = PetscContainerGetPointer(cab_dense,(void**)&ab_dense);CHKERRQ(ierr);
283   ierr = PetscArrayzero(ab_dense,B->cmap->N);CHKERRQ(ierr);
284 
285   /* clean old values in C */
286   ierr = PetscArrayzero(ca,ci[cm]);CHKERRQ(ierr);
287   /* Traverse A row-wise. */
288   /* Build the ith row in C by summing over nonzero columns in A, */
289   /* the rows of B corresponding to nonzeros of A. */
290   for (i=0; i<am; i++) {
291     anzi = ai[i+1] - ai[i];
292     for (j=0; j<anzi; j++) {
293       brow = aj[j];
294       bnzi = bi[brow+1] - bi[brow];
295       bjj  = bj + bi[brow];
296       baj  = ba + bi[brow];
297       /* perform dense axpy */
298       valtmp = aa[j];
299       for (k=0; k<bnzi; k++) {
300         ab_dense[bjj[k]] += valtmp*baj[k];
301       }
302       flops += 2*bnzi;
303     }
304     aj += anzi; aa += anzi;
305 
306     cnzi = ci[i+1] - ci[i];
307     for (k=0; k<cnzi; k++) {
308       ca[k]          += ab_dense[cj[k]];
309       ab_dense[cj[k]] = 0.0; /* zero ab_dense */
310     }
311     flops += cnzi;
312     cj    += cnzi; ca += cnzi;
313   }
314 #if defined(PETSC_HAVE_DEVICE)
315   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
316 #endif
317   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
318   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
319   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
320   ierr = MatSeqAIJRestoreArrayRead(A,&aa);CHKERRQ(ierr);
321   ierr = MatSeqAIJRestoreArrayRead(B,&ba);CHKERRQ(ierr);
322   PetscFunctionReturn(0);
323 }
324 
325 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable(Mat A,Mat B,Mat C)
326 {
327   PetscErrorCode    ierr;
328   PetscLogDouble    flops=0.0;
329   Mat_SeqAIJ        *a   = (Mat_SeqAIJ*)A->data;
330   Mat_SeqAIJ        *b   = (Mat_SeqAIJ*)B->data;
331   Mat_SeqAIJ        *c   = (Mat_SeqAIJ*)C->data;
332   PetscInt          *ai  = a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bjj,*ci=c->i,*cj=c->j;
333   PetscInt          am   = A->rmap->N,cm=C->rmap->N;
334   PetscInt          i,j,k,anzi,bnzi,cnzi,brow;
335   PetscScalar       *ca=c->a,valtmp;
336   const PetscScalar *aa,*ba,*baj;
337   PetscInt          nextb;
338 
339   PetscFunctionBegin;
340   ierr = MatSeqAIJGetArrayRead(A,&aa);CHKERRQ(ierr);
341   ierr = MatSeqAIJGetArrayRead(B,&ba);CHKERRQ(ierr);
342   if (!ca) { /* first call of MatMatMultNumeric_SeqAIJ_SeqAIJ, allocate ca and matmult_abdense */
343     ierr      = PetscMalloc1(ci[cm]+1,&ca);CHKERRQ(ierr);
344     c->a      = ca;
345     c->free_a = PETSC_TRUE;
346   }
347 
348   /* clean old values in C */
349   ierr = PetscArrayzero(ca,ci[cm]);CHKERRQ(ierr);
350   /* Traverse A row-wise. */
351   /* Build the ith row in C by summing over nonzero columns in A, */
352   /* the rows of B corresponding to nonzeros of A. */
353   for (i=0; i<am; i++) {
354     anzi = ai[i+1] - ai[i];
355     cnzi = ci[i+1] - ci[i];
356     for (j=0; j<anzi; j++) {
357       brow = aj[j];
358       bnzi = bi[brow+1] - bi[brow];
359       bjj  = bj + bi[brow];
360       baj  = ba + bi[brow];
361       /* perform sparse axpy */
362       valtmp = aa[j];
363       nextb  = 0;
364       for (k=0; nextb<bnzi; k++) {
365         if (cj[k] == bjj[nextb]) { /* ccol == bcol */
366           ca[k] += valtmp*baj[nextb++];
367         }
368       }
369       flops += 2*bnzi;
370     }
371     aj += anzi; aa += anzi;
372     cj += cnzi; ca += cnzi;
373   }
374 #if defined(PETSC_HAVE_DEVICE)
375   if (C->offloadmask != PETSC_OFFLOAD_UNALLOCATED) C->offloadmask = PETSC_OFFLOAD_CPU;
376 #endif
377   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
378   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
379   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
380   ierr = MatSeqAIJRestoreArrayRead(A,&aa);CHKERRQ(ierr);
381   ierr = MatSeqAIJRestoreArrayRead(B,&ba);CHKERRQ(ierr);
382   PetscFunctionReturn(0);
383 }
384 
385 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable_fast(Mat A,Mat B,PetscReal fill,Mat C)
386 {
387   PetscErrorCode     ierr;
388   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
389   PetscInt           *ai = a->i,*bi=b->i,*ci,*cj;
390   PetscInt           am  = A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
391   MatScalar          *ca;
392   PetscReal          afill;
393   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,*lnk,ndouble=0,Crmax;
394   PetscTable         ta;
395   PetscFreeSpaceList free_space=NULL,current_space=NULL;
396 
397   PetscFunctionBegin;
398   /* Get ci and cj - same as MatMatMultSymbolic_SeqAIJ_SeqAIJ except using PetscLLxxx_fast() */
399   /*-----------------------------------------------------------------------------------------*/
400   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
401   ierr  = PetscMalloc1(am+2,&ci);CHKERRQ(ierr);
402   ci[0] = 0;
403 
404   /* create and initialize a linked list */
405   ierr = PetscTableCreate(bn,bn,&ta);CHKERRQ(ierr);
406   MatRowMergeMax_SeqAIJ(b,bm,ta);
407   ierr = PetscTableGetCount(ta,&Crmax);CHKERRQ(ierr);
408   ierr = PetscTableDestroy(&ta);CHKERRQ(ierr);
409 
410   ierr = PetscLLCondensedCreate_fast(Crmax,&lnk);CHKERRQ(ierr);
411 
412   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
413   ierr          = PetscFreeSpaceGet(PetscRealIntMultTruncate(fill,PetscIntSumTruncate(ai[am],bi[bm])),&free_space);CHKERRQ(ierr);
414   current_space = free_space;
415 
416   /* Determine ci and cj */
417   for (i=0; i<am; i++) {
418     anzi = ai[i+1] - ai[i];
419     aj   = a->j + ai[i];
420     for (j=0; j<anzi; j++) {
421       brow = aj[j];
422       bnzj = bi[brow+1] - bi[brow];
423       bj   = b->j + bi[brow];
424       /* add non-zero cols of B into the sorted linked list lnk */
425       ierr = PetscLLCondensedAddSorted_fast(bnzj,bj,lnk);CHKERRQ(ierr);
426     }
427     /* add possible missing diagonal entry */
428     if (C->force_diagonals) {
429       ierr = PetscLLCondensedAddSorted_fast(1,&i,lnk);CHKERRQ(ierr);
430     }
431     cnzi = lnk[1];
432 
433     /* If free space is not available, make more free space */
434     /* Double the amount of total space in the list */
435     if (current_space->local_remaining<cnzi) {
436       ierr = PetscFreeSpaceGet(PetscIntSumTruncate(cnzi,current_space->total_array_size),&current_space);CHKERRQ(ierr);
437       ndouble++;
438     }
439 
440     /* Copy data into free space, then initialize lnk */
441     ierr = PetscLLCondensedClean_fast(cnzi,current_space->array,lnk);CHKERRQ(ierr);
442 
443     current_space->array           += cnzi;
444     current_space->local_used      += cnzi;
445     current_space->local_remaining -= cnzi;
446 
447     ci[i+1] = ci[i] + cnzi;
448   }
449 
450   /* Column indices are in the list of free space */
451   /* Allocate space for cj, initialize cj, and */
452   /* destroy list of free space and other temporary array(s) */
453   ierr = PetscMalloc1(ci[am]+1,&cj);CHKERRQ(ierr);
454   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
455   ierr = PetscLLCondensedDestroy_fast(lnk);CHKERRQ(ierr);
456 
457   /* Allocate space for ca */
458   ierr = PetscCalloc1(ci[am]+1,&ca);CHKERRQ(ierr);
459 
460   /* put together the new symbolic matrix */
461   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,ca,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
462   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
463 
464   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
465   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
466   c          = (Mat_SeqAIJ*)(C->data);
467   c->free_a  = PETSC_TRUE;
468   c->free_ij = PETSC_TRUE;
469   c->nonew   = 0;
470 
471   /* slower, less memory */
472   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable;
473 
474   /* set MatInfo */
475   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
476   if (afill < 1.0) afill = 1.0;
477   c->maxnz                     = ci[am];
478   c->nz                        = ci[am];
479   C->info.mallocs           = ndouble;
480   C->info.fill_ratio_given  = fill;
481   C->info.fill_ratio_needed = afill;
482 
483 #if defined(PETSC_USE_INFO)
484   if (ci[am]) {
485     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
486     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
487   } else {
488     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
489   }
490 #endif
491   PetscFunctionReturn(0);
492 }
493 
494 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable(Mat A,Mat B,PetscReal fill,Mat C)
495 {
496   PetscErrorCode     ierr;
497   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
498   PetscInt           *ai = a->i,*bi=b->i,*ci,*cj;
499   PetscInt           am  = A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
500   MatScalar          *ca;
501   PetscReal          afill;
502   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,*lnk,ndouble=0,Crmax;
503   PetscTable         ta;
504   PetscFreeSpaceList free_space=NULL,current_space=NULL;
505 
506   PetscFunctionBegin;
507   /* Get ci and cj - same as MatMatMultSymbolic_SeqAIJ_SeqAIJ except using PetscLLxxx_Scalalbe() */
508   /*---------------------------------------------------------------------------------------------*/
509   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
510   ierr  = PetscMalloc1(am+2,&ci);CHKERRQ(ierr);
511   ci[0] = 0;
512 
513   /* create and initialize a linked list */
514   ierr = PetscTableCreate(bn,bn,&ta);CHKERRQ(ierr);
515   MatRowMergeMax_SeqAIJ(b,bm,ta);
516   ierr = PetscTableGetCount(ta,&Crmax);CHKERRQ(ierr);
517   ierr = PetscTableDestroy(&ta);CHKERRQ(ierr);
518   ierr = PetscLLCondensedCreate_Scalable(Crmax,&lnk);CHKERRQ(ierr);
519 
520   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
521   ierr = PetscFreeSpaceGet(PetscRealIntMultTruncate(fill,PetscIntSumTruncate(ai[am],bi[bm])),&free_space);CHKERRQ(ierr);
522   current_space = free_space;
523 
524   /* Determine ci and cj */
525   for (i=0; i<am; i++) {
526     anzi = ai[i+1] - ai[i];
527     aj   = a->j + ai[i];
528     for (j=0; j<anzi; j++) {
529       brow = aj[j];
530       bnzj = bi[brow+1] - bi[brow];
531       bj   = b->j + bi[brow];
532       /* add non-zero cols of B into the sorted linked list lnk */
533       ierr = PetscLLCondensedAddSorted_Scalable(bnzj,bj,lnk);CHKERRQ(ierr);
534     }
535     /* add possible missing diagonal entry */
536     if (C->force_diagonals) {
537       ierr = PetscLLCondensedAddSorted_Scalable(1,&i,lnk);CHKERRQ(ierr);
538     }
539 
540     cnzi = lnk[0];
541 
542     /* If free space is not available, make more free space */
543     /* Double the amount of total space in the list */
544     if (current_space->local_remaining<cnzi) {
545       ierr = PetscFreeSpaceGet(PetscIntSumTruncate(cnzi,current_space->total_array_size),&current_space);CHKERRQ(ierr);
546       ndouble++;
547     }
548 
549     /* Copy data into free space, then initialize lnk */
550     ierr = PetscLLCondensedClean_Scalable(cnzi,current_space->array,lnk);CHKERRQ(ierr);
551 
552     current_space->array           += cnzi;
553     current_space->local_used      += cnzi;
554     current_space->local_remaining -= cnzi;
555 
556     ci[i+1] = ci[i] + cnzi;
557   }
558 
559   /* Column indices are in the list of free space */
560   /* Allocate space for cj, initialize cj, and */
561   /* destroy list of free space and other temporary array(s) */
562   ierr = PetscMalloc1(ci[am]+1,&cj);CHKERRQ(ierr);
563   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
564   ierr = PetscLLCondensedDestroy_Scalable(lnk);CHKERRQ(ierr);
565 
566   /* Allocate space for ca */
567   /*-----------------------*/
568   ierr = PetscCalloc1(ci[am]+1,&ca);CHKERRQ(ierr);
569 
570   /* put together the new symbolic matrix */
571   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,ca,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
572   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
573 
574   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
575   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
576   c          = (Mat_SeqAIJ*)(C->data);
577   c->free_a  = PETSC_TRUE;
578   c->free_ij = PETSC_TRUE;
579   c->nonew   = 0;
580 
581   /* slower, less memory */
582   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable;
583 
584   /* set MatInfo */
585   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
586   if (afill < 1.0) afill = 1.0;
587   c->maxnz                     = ci[am];
588   c->nz                        = ci[am];
589   C->info.mallocs           = ndouble;
590   C->info.fill_ratio_given  = fill;
591   C->info.fill_ratio_needed = afill;
592 
593 #if defined(PETSC_USE_INFO)
594   if (ci[am]) {
595     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
596     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
597   } else {
598     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
599   }
600 #endif
601   PetscFunctionReturn(0);
602 }
603 
604 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Heap(Mat A,Mat B,PetscReal fill,Mat C)
605 {
606   PetscErrorCode     ierr;
607   Mat_SeqAIJ         *a = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
608   const PetscInt     *ai=a->i,*bi=b->i,*aj=a->j,*bj=b->j;
609   PetscInt           *ci,*cj,*bb;
610   PetscInt           am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
611   PetscReal          afill;
612   PetscInt           i,j,col,ndouble = 0;
613   PetscFreeSpaceList free_space=NULL,current_space=NULL;
614   PetscHeap          h;
615 
616   PetscFunctionBegin;
617   /* Get ci and cj - by merging sorted rows using a heap */
618   /*---------------------------------------------------------------------------------------------*/
619   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
620   ierr  = PetscMalloc1(am+2,&ci);CHKERRQ(ierr);
621   ci[0] = 0;
622 
623   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
624   ierr          = PetscFreeSpaceGet(PetscRealIntMultTruncate(fill,PetscIntSumTruncate(ai[am],bi[bm])),&free_space);CHKERRQ(ierr);
625   current_space = free_space;
626 
627   ierr = PetscHeapCreate(a->rmax,&h);CHKERRQ(ierr);
628   ierr = PetscMalloc1(a->rmax,&bb);CHKERRQ(ierr);
629 
630   /* Determine ci and cj */
631   for (i=0; i<am; i++) {
632     const PetscInt anzi  = ai[i+1] - ai[i]; /* number of nonzeros in this row of A, this is the number of rows of B that we merge */
633     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
634     ci[i+1] = ci[i];
635     /* Populate the min heap */
636     for (j=0; j<anzi; j++) {
637       bb[j] = bi[acol[j]];         /* bb points at the start of the row */
638       if (bb[j] < bi[acol[j]+1]) { /* Add if row is nonempty */
639         ierr = PetscHeapAdd(h,j,bj[bb[j]++]);CHKERRQ(ierr);
640       }
641     }
642     /* Pick off the min element, adding it to free space */
643     ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
644     while (j >= 0) {
645       if (current_space->local_remaining < 1) { /* double the size, but don't exceed 16 MiB */
646         ierr = PetscFreeSpaceGet(PetscMin(PetscIntMultTruncate(2,current_space->total_array_size),16 << 20),&current_space);CHKERRQ(ierr);
647         ndouble++;
648       }
649       *(current_space->array++) = col;
650       current_space->local_used++;
651       current_space->local_remaining--;
652       ci[i+1]++;
653 
654       /* stash if anything else remains in this row of B */
655       if (bb[j] < bi[acol[j]+1]) {ierr = PetscHeapStash(h,j,bj[bb[j]++]);CHKERRQ(ierr);}
656       while (1) {               /* pop and stash any other rows of B that also had an entry in this column */
657         PetscInt j2,col2;
658         ierr = PetscHeapPeek(h,&j2,&col2);CHKERRQ(ierr);
659         if (col2 != col) break;
660         ierr = PetscHeapPop(h,&j2,&col2);CHKERRQ(ierr);
661         if (bb[j2] < bi[acol[j2]+1]) {ierr = PetscHeapStash(h,j2,bj[bb[j2]++]);CHKERRQ(ierr);}
662       }
663       /* Put any stashed elements back into the min heap */
664       ierr = PetscHeapUnstash(h);CHKERRQ(ierr);
665       ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
666     }
667   }
668   ierr = PetscFree(bb);CHKERRQ(ierr);
669   ierr = PetscHeapDestroy(&h);CHKERRQ(ierr);
670 
671   /* Column indices are in the list of free space */
672   /* Allocate space for cj, initialize cj, and */
673   /* destroy list of free space and other temporary array(s) */
674   ierr = PetscMalloc1(ci[am],&cj);CHKERRQ(ierr);
675   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
676 
677   /* put together the new symbolic matrix */
678   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
679   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
680 
681   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
682   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
683   c          = (Mat_SeqAIJ*)(C->data);
684   c->free_a  = PETSC_TRUE;
685   c->free_ij = PETSC_TRUE;
686   c->nonew   = 0;
687 
688   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted;
689 
690   /* set MatInfo */
691   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
692   if (afill < 1.0) afill = 1.0;
693   c->maxnz                     = ci[am];
694   c->nz                        = ci[am];
695   C->info.mallocs           = ndouble;
696   C->info.fill_ratio_given  = fill;
697   C->info.fill_ratio_needed = afill;
698 
699 #if defined(PETSC_USE_INFO)
700   if (ci[am]) {
701     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
702     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
703   } else {
704     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
705   }
706 #endif
707   PetscFunctionReturn(0);
708 }
709 
710 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_BTHeap(Mat A,Mat B,PetscReal fill,Mat C)
711 {
712   PetscErrorCode     ierr;
713   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
714   const PetscInt     *ai = a->i,*bi=b->i,*aj=a->j,*bj=b->j;
715   PetscInt           *ci,*cj,*bb;
716   PetscInt           am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
717   PetscReal          afill;
718   PetscInt           i,j,col,ndouble = 0;
719   PetscFreeSpaceList free_space=NULL,current_space=NULL;
720   PetscHeap          h;
721   PetscBT            bt;
722 
723   PetscFunctionBegin;
724   /* Get ci and cj - using a heap for the sorted rows, but use BT so that each index is only added once */
725   /*---------------------------------------------------------------------------------------------*/
726   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
727   ierr  = PetscMalloc1(am+2,&ci);CHKERRQ(ierr);
728   ci[0] = 0;
729 
730   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
731   ierr = PetscFreeSpaceGet(PetscRealIntMultTruncate(fill,PetscIntSumTruncate(ai[am],bi[bm])),&free_space);CHKERRQ(ierr);
732 
733   current_space = free_space;
734 
735   ierr = PetscHeapCreate(a->rmax,&h);CHKERRQ(ierr);
736   ierr = PetscMalloc1(a->rmax,&bb);CHKERRQ(ierr);
737   ierr = PetscBTCreate(bn,&bt);CHKERRQ(ierr);
738 
739   /* Determine ci and cj */
740   for (i=0; i<am; i++) {
741     const PetscInt anzi  = ai[i+1] - ai[i]; /* number of nonzeros in this row of A, this is the number of rows of B that we merge */
742     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
743     const PetscInt *fptr = current_space->array; /* Save beginning of the row so we can clear the BT later */
744     ci[i+1] = ci[i];
745     /* Populate the min heap */
746     for (j=0; j<anzi; j++) {
747       PetscInt brow = acol[j];
748       for (bb[j] = bi[brow]; bb[j] < bi[brow+1]; bb[j]++) {
749         PetscInt bcol = bj[bb[j]];
750         if (!PetscBTLookupSet(bt,bcol)) { /* new entry */
751           ierr = PetscHeapAdd(h,j,bcol);CHKERRQ(ierr);
752           bb[j]++;
753           break;
754         }
755       }
756     }
757     /* Pick off the min element, adding it to free space */
758     ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
759     while (j >= 0) {
760       if (current_space->local_remaining < 1) { /* double the size, but don't exceed 16 MiB */
761         fptr = NULL;                      /* need PetscBTMemzero */
762         ierr = PetscFreeSpaceGet(PetscMin(PetscIntMultTruncate(2,current_space->total_array_size),16 << 20),&current_space);CHKERRQ(ierr);
763         ndouble++;
764       }
765       *(current_space->array++) = col;
766       current_space->local_used++;
767       current_space->local_remaining--;
768       ci[i+1]++;
769 
770       /* stash if anything else remains in this row of B */
771       for (; bb[j] < bi[acol[j]+1]; bb[j]++) {
772         PetscInt bcol = bj[bb[j]];
773         if (!PetscBTLookupSet(bt,bcol)) { /* new entry */
774           ierr = PetscHeapAdd(h,j,bcol);CHKERRQ(ierr);
775           bb[j]++;
776           break;
777         }
778       }
779       ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
780     }
781     if (fptr) {                 /* Clear the bits for this row */
782       for (; fptr<current_space->array; fptr++) {ierr = PetscBTClear(bt,*fptr);CHKERRQ(ierr);}
783     } else {                    /* We reallocated so we don't remember (easily) how to clear only the bits we changed */
784       ierr = PetscBTMemzero(bn,bt);CHKERRQ(ierr);
785     }
786   }
787   ierr = PetscFree(bb);CHKERRQ(ierr);
788   ierr = PetscHeapDestroy(&h);CHKERRQ(ierr);
789   ierr = PetscBTDestroy(&bt);CHKERRQ(ierr);
790 
791   /* Column indices are in the list of free space */
792   /* Allocate space for cj, initialize cj, and */
793   /* destroy list of free space and other temporary array(s) */
794   ierr = PetscMalloc1(ci[am],&cj);CHKERRQ(ierr);
795   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
796 
797   /* put together the new symbolic matrix */
798   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
799   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
800 
801   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
802   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
803   c          = (Mat_SeqAIJ*)(C->data);
804   c->free_a  = PETSC_TRUE;
805   c->free_ij = PETSC_TRUE;
806   c->nonew   = 0;
807 
808   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted;
809 
810   /* set MatInfo */
811   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
812   if (afill < 1.0) afill = 1.0;
813   c->maxnz                     = ci[am];
814   c->nz                        = ci[am];
815   C->info.mallocs           = ndouble;
816   C->info.fill_ratio_given  = fill;
817   C->info.fill_ratio_needed = afill;
818 
819 #if defined(PETSC_USE_INFO)
820   if (ci[am]) {
821     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
822     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
823   } else {
824     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
825   }
826 #endif
827   PetscFunctionReturn(0);
828 }
829 
830 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_RowMerge(Mat A,Mat B,PetscReal fill,Mat C)
831 {
832   PetscErrorCode     ierr;
833   Mat_SeqAIJ         *a=(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
834   const PetscInt     *ai=a->i,*bi=b->i,*aj=a->j,*bj=b->j,*inputi,*inputj,*inputcol,*inputcol_L1;
835   PetscInt           *ci,*cj,*outputj,worki_L1[9],worki_L2[9];
836   PetscInt           c_maxmem,a_maxrownnz=0,a_rownnz;
837   const PetscInt     workcol[8]={0,1,2,3,4,5,6,7};
838   const PetscInt     am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
839   const PetscInt     *brow_ptr[8],*brow_end[8];
840   PetscInt           window[8];
841   PetscInt           window_min,old_window_min,ci_nnz,outputi_nnz=0,L1_nrows,L2_nrows;
842   PetscInt           i,k,ndouble=0,L1_rowsleft,rowsleft;
843   PetscReal          afill;
844   PetscInt           *workj_L1,*workj_L2,*workj_L3;
845   PetscInt           L1_nnz,L2_nnz;
846 
847   /* Step 1: Get upper bound on memory required for allocation.
848              Because of the way virtual memory works,
849              only the memory pages that are actually needed will be physically allocated. */
850   PetscFunctionBegin;
851   ierr = PetscMalloc1(am+1,&ci);CHKERRQ(ierr);
852   for (i=0; i<am; i++) {
853     const PetscInt anzi  = ai[i+1] - ai[i]; /* number of nonzeros in this row of A, this is the number of rows of B that we merge */
854     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
855     a_rownnz = 0;
856     for (k=0; k<anzi; ++k) {
857       a_rownnz += bi[acol[k]+1] - bi[acol[k]];
858       if (a_rownnz > bn) {
859         a_rownnz = bn;
860         break;
861       }
862     }
863     a_maxrownnz = PetscMax(a_maxrownnz, a_rownnz);
864   }
865   /* temporary work areas for merging rows */
866   ierr = PetscMalloc1(a_maxrownnz*8,&workj_L1);CHKERRQ(ierr);
867   ierr = PetscMalloc1(a_maxrownnz*8,&workj_L2);CHKERRQ(ierr);
868   ierr = PetscMalloc1(a_maxrownnz,&workj_L3);CHKERRQ(ierr);
869 
870   /* This should be enough for almost all matrices. If not, memory is reallocated later. */
871   c_maxmem = 8*(ai[am]+bi[bm]);
872   /* Step 2: Populate pattern for C */
873   ierr  = PetscMalloc1(c_maxmem,&cj);CHKERRQ(ierr);
874 
875   ci_nnz       = 0;
876   ci[0]        = 0;
877   worki_L1[0]  = 0;
878   worki_L2[0]  = 0;
879   for (i=0; i<am; i++) {
880     const PetscInt anzi  = ai[i+1] - ai[i]; /* number of nonzeros in this row of A, this is the number of rows of B that we merge */
881     const PetscInt *acol = aj + ai[i];      /* column indices of nonzero entries in this row */
882     rowsleft             = anzi;
883     inputcol_L1          = acol;
884     L2_nnz               = 0;
885     L2_nrows             = 1;  /* Number of rows to be merged on Level 3. output of L3 already exists -> initial value 1   */
886     worki_L2[1]          = 0;
887     outputi_nnz          = 0;
888 
889     /* If the number of indices in C so far + the max number of columns in the next row > c_maxmem  -> allocate more memory */
890     while (ci_nnz+a_maxrownnz > c_maxmem) {
891       c_maxmem *= 2;
892       ndouble++;
893       ierr = PetscRealloc(sizeof(PetscInt)*c_maxmem,&cj);CHKERRQ(ierr);
894     }
895 
896     while (rowsleft) {
897       L1_rowsleft = PetscMin(64, rowsleft); /* In the inner loop max 64 rows of B can be merged */
898       L1_nrows    = 0;
899       L1_nnz      = 0;
900       inputcol    = inputcol_L1;
901       inputi      = bi;
902       inputj      = bj;
903 
904       /* The following macro is used to specialize for small rows in A.
905          This helps with compiler unrolling, improving performance substantially.
906           Input:  inputj   inputi  inputcol  bn
907           Output: outputj  outputi_nnz                       */
908        #define MatMatMultSymbolic_RowMergeMacro(ANNZ)                        \
909          window_min  = bn;                                                   \
910          outputi_nnz = 0;                                                    \
911          for (k=0; k<ANNZ; ++k) {                                            \
912            brow_ptr[k] = inputj + inputi[inputcol[k]];                       \
913            brow_end[k] = inputj + inputi[inputcol[k]+1];                     \
914            window[k]   = (brow_ptr[k] != brow_end[k]) ? *brow_ptr[k] : bn;   \
915            window_min  = PetscMin(window[k], window_min);                    \
916          }                                                                   \
917          while (window_min < bn) {                                           \
918            outputj[outputi_nnz++] = window_min;                              \
919            /* advance front and compute new minimum */                       \
920            old_window_min = window_min;                                      \
921            window_min = bn;                                                  \
922            for (k=0; k<ANNZ; ++k) {                                          \
923              if (window[k] == old_window_min) {                              \
924                brow_ptr[k]++;                                                \
925                window[k] = (brow_ptr[k] != brow_end[k]) ? *brow_ptr[k] : bn; \
926              }                                                               \
927              window_min = PetscMin(window[k], window_min);                   \
928            }                                                                 \
929          }
930 
931       /************** L E V E L  1 ***************/
932       /* Merge up to 8 rows of B to L1 work array*/
933       while (L1_rowsleft) {
934         outputi_nnz = 0;
935         if (anzi > 8)  outputj = workj_L1 + L1_nnz;     /* Level 1 rowmerge*/
936         else           outputj = cj + ci_nnz;           /* Merge directly to C */
937 
938         switch (L1_rowsleft) {
939         case 1:  brow_ptr[0] = inputj + inputi[inputcol[0]];
940                  brow_end[0] = inputj + inputi[inputcol[0]+1];
941                  for (; brow_ptr[0] != brow_end[0]; ++brow_ptr[0]) outputj[outputi_nnz++] = *brow_ptr[0]; /* copy row in b over */
942                  inputcol    += L1_rowsleft;
943                  rowsleft    -= L1_rowsleft;
944                  L1_rowsleft  = 0;
945                  break;
946         case 2:  MatMatMultSymbolic_RowMergeMacro(2);
947                  inputcol    += L1_rowsleft;
948                  rowsleft    -= L1_rowsleft;
949                  L1_rowsleft  = 0;
950                  break;
951         case 3: MatMatMultSymbolic_RowMergeMacro(3);
952                  inputcol    += L1_rowsleft;
953                  rowsleft    -= L1_rowsleft;
954                  L1_rowsleft  = 0;
955                  break;
956         case 4:  MatMatMultSymbolic_RowMergeMacro(4);
957                  inputcol    += L1_rowsleft;
958                  rowsleft    -= L1_rowsleft;
959                  L1_rowsleft  = 0;
960                  break;
961         case 5:  MatMatMultSymbolic_RowMergeMacro(5);
962                  inputcol    += L1_rowsleft;
963                  rowsleft    -= L1_rowsleft;
964                  L1_rowsleft  = 0;
965                  break;
966         case 6:  MatMatMultSymbolic_RowMergeMacro(6);
967                  inputcol    += L1_rowsleft;
968                  rowsleft    -= L1_rowsleft;
969                  L1_rowsleft  = 0;
970                  break;
971         case 7:  MatMatMultSymbolic_RowMergeMacro(7);
972                  inputcol    += L1_rowsleft;
973                  rowsleft    -= L1_rowsleft;
974                  L1_rowsleft  = 0;
975                  break;
976         default: MatMatMultSymbolic_RowMergeMacro(8);
977                  inputcol    += 8;
978                  rowsleft    -= 8;
979                  L1_rowsleft -= 8;
980                  break;
981         }
982         inputcol_L1           = inputcol;
983         L1_nnz               += outputi_nnz;
984         worki_L1[++L1_nrows]  = L1_nnz;
985       }
986 
987       /********************** L E V E L  2 ************************/
988       /* Merge from L1 work array to either C or to L2 work array */
989       if (anzi > 8) {
990         inputi      = worki_L1;
991         inputj      = workj_L1;
992         inputcol    = workcol;
993         outputi_nnz = 0;
994 
995         if (anzi <= 64) outputj = cj + ci_nnz;        /* Merge from L1 work array to C */
996         else            outputj = workj_L2 + L2_nnz;  /* Merge from L1 work array to L2 work array */
997 
998         switch (L1_nrows) {
999         case 1:  brow_ptr[0] = inputj + inputi[inputcol[0]];
1000                  brow_end[0] = inputj + inputi[inputcol[0]+1];
1001                  for (; brow_ptr[0] != brow_end[0]; ++brow_ptr[0]) outputj[outputi_nnz++] = *brow_ptr[0]; /* copy row in b over */
1002                  break;
1003         case 2:  MatMatMultSymbolic_RowMergeMacro(2); break;
1004         case 3:  MatMatMultSymbolic_RowMergeMacro(3); break;
1005         case 4:  MatMatMultSymbolic_RowMergeMacro(4); break;
1006         case 5:  MatMatMultSymbolic_RowMergeMacro(5); break;
1007         case 6:  MatMatMultSymbolic_RowMergeMacro(6); break;
1008         case 7:  MatMatMultSymbolic_RowMergeMacro(7); break;
1009         case 8:  MatMatMultSymbolic_RowMergeMacro(8); break;
1010         default: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"MatMatMult logic error: Not merging 1-8 rows from L1 work array!");
1011         }
1012         L2_nnz               += outputi_nnz;
1013         worki_L2[++L2_nrows]  = L2_nnz;
1014 
1015         /************************ L E V E L  3 **********************/
1016         /* Merge from L2 work array to either C or to L2 work array */
1017         if (anzi > 64 && (L2_nrows == 8 || rowsleft == 0)) {
1018           inputi      = worki_L2;
1019           inputj      = workj_L2;
1020           inputcol    = workcol;
1021           outputi_nnz = 0;
1022           if (rowsleft) outputj = workj_L3;
1023           else          outputj = cj + ci_nnz;
1024           switch (L2_nrows) {
1025           case 1:  brow_ptr[0] = inputj + inputi[inputcol[0]];
1026                    brow_end[0] = inputj + inputi[inputcol[0]+1];
1027                    for (; brow_ptr[0] != brow_end[0]; ++brow_ptr[0]) outputj[outputi_nnz++] = *brow_ptr[0]; /* copy row in b over */
1028                    break;
1029           case 2:  MatMatMultSymbolic_RowMergeMacro(2); break;
1030           case 3:  MatMatMultSymbolic_RowMergeMacro(3); break;
1031           case 4:  MatMatMultSymbolic_RowMergeMacro(4); break;
1032           case 5:  MatMatMultSymbolic_RowMergeMacro(5); break;
1033           case 6:  MatMatMultSymbolic_RowMergeMacro(6); break;
1034           case 7:  MatMatMultSymbolic_RowMergeMacro(7); break;
1035           case 8:  MatMatMultSymbolic_RowMergeMacro(8); break;
1036           default: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"MatMatMult logic error: Not merging 1-8 rows from L2 work array!");
1037           }
1038           L2_nrows    = 1;
1039           L2_nnz      = outputi_nnz;
1040           worki_L2[1] = outputi_nnz;
1041           /* Copy to workj_L2 */
1042           if (rowsleft) {
1043             for (k=0; k<outputi_nnz; ++k)  workj_L2[k] = outputj[k];
1044           }
1045         }
1046       }
1047     }  /* while (rowsleft) */
1048 #undef MatMatMultSymbolic_RowMergeMacro
1049 
1050     /* terminate current row */
1051     ci_nnz += outputi_nnz;
1052     ci[i+1] = ci_nnz;
1053   }
1054 
1055   /* Step 3: Create the new symbolic matrix */
1056   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
1057   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
1058 
1059   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
1060   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
1061   c          = (Mat_SeqAIJ*)(C->data);
1062   c->free_a  = PETSC_TRUE;
1063   c->free_ij = PETSC_TRUE;
1064   c->nonew   = 0;
1065 
1066   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted;
1067 
1068   /* set MatInfo */
1069   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
1070   if (afill < 1.0) afill = 1.0;
1071   c->maxnz                     = ci[am];
1072   c->nz                        = ci[am];
1073   C->info.mallocs           = ndouble;
1074   C->info.fill_ratio_given  = fill;
1075   C->info.fill_ratio_needed = afill;
1076 
1077 #if defined(PETSC_USE_INFO)
1078   if (ci[am]) {
1079     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
1080     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
1081   } else {
1082     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
1083   }
1084 #endif
1085 
1086   /* Step 4: Free temporary work areas */
1087   ierr = PetscFree(workj_L1);CHKERRQ(ierr);
1088   ierr = PetscFree(workj_L2);CHKERRQ(ierr);
1089   ierr = PetscFree(workj_L3);CHKERRQ(ierr);
1090   PetscFunctionReturn(0);
1091 }
1092 
1093 /* concatenate unique entries and then sort */
1094 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Sorted(Mat A,Mat B,PetscReal fill,Mat C)
1095 {
1096   PetscErrorCode ierr;
1097   Mat_SeqAIJ     *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
1098   const PetscInt *ai = a->i,*bi=b->i,*aj=a->j,*bj=b->j;
1099   PetscInt       *ci,*cj,bcol;
1100   PetscInt       am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
1101   PetscReal      afill;
1102   PetscInt       i,j,ndouble = 0;
1103   PetscSegBuffer seg,segrow;
1104   char           *seen;
1105 
1106   PetscFunctionBegin;
1107   ierr  = PetscMalloc1(am+1,&ci);CHKERRQ(ierr);
1108   ci[0] = 0;
1109 
1110   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
1111   ierr = PetscSegBufferCreate(sizeof(PetscInt),(PetscInt)(fill*(ai[am]+bi[bm])),&seg);CHKERRQ(ierr);
1112   ierr = PetscSegBufferCreate(sizeof(PetscInt),100,&segrow);CHKERRQ(ierr);
1113   ierr = PetscCalloc1(bn,&seen);CHKERRQ(ierr);
1114 
1115   /* Determine ci and cj */
1116   for (i=0; i<am; i++) {
1117     const PetscInt anzi  = ai[i+1] - ai[i]; /* number of nonzeros in this row of A, this is the number of rows of B that we merge */
1118     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
1119     PetscInt packlen = 0,*PETSC_RESTRICT crow;
1120 
1121     /* Pack segrow */
1122     for (j=0; j<anzi; j++) {
1123       PetscInt brow = acol[j],bjstart = bi[brow],bjend = bi[brow+1],k;
1124       for (k=bjstart; k<bjend; k++) {
1125         bcol = bj[k];
1126         if (!seen[bcol]) { /* new entry */
1127           PetscInt *PETSC_RESTRICT slot;
1128           ierr = PetscSegBufferGetInts(segrow,1,&slot);CHKERRQ(ierr);
1129           *slot = bcol;
1130           seen[bcol] = 1;
1131           packlen++;
1132         }
1133       }
1134     }
1135 
1136     /* Check i-th diagonal entry */
1137     if (C->force_diagonals && !seen[i]) {
1138       PetscInt *PETSC_RESTRICT slot;
1139       ierr = PetscSegBufferGetInts(segrow,1,&slot);CHKERRQ(ierr);
1140       *slot   = i;
1141       seen[i] = 1;
1142       packlen++;
1143     }
1144 
1145     ierr = PetscSegBufferGetInts(seg,packlen,&crow);CHKERRQ(ierr);
1146     ierr = PetscSegBufferExtractTo(segrow,crow);CHKERRQ(ierr);
1147     ierr = PetscSortInt(packlen,crow);CHKERRQ(ierr);
1148     ci[i+1] = ci[i] + packlen;
1149     for (j=0; j<packlen; j++) seen[crow[j]] = 0;
1150   }
1151   ierr = PetscSegBufferDestroy(&segrow);CHKERRQ(ierr);
1152   ierr = PetscFree(seen);CHKERRQ(ierr);
1153 
1154   /* Column indices are in the segmented buffer */
1155   ierr = PetscSegBufferExtractAlloc(seg,&cj);CHKERRQ(ierr);
1156   ierr = PetscSegBufferDestroy(&seg);CHKERRQ(ierr);
1157 
1158   /* put together the new symbolic matrix */
1159   ierr = MatSetSeqAIJWithArrays_private(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,((PetscObject)A)->type_name,C);CHKERRQ(ierr);
1160   ierr = MatSetBlockSizesFromMats(C,A,B);CHKERRQ(ierr);
1161 
1162   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
1163   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
1164   c          = (Mat_SeqAIJ*)(C->data);
1165   c->free_a  = PETSC_TRUE;
1166   c->free_ij = PETSC_TRUE;
1167   c->nonew   = 0;
1168 
1169   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted;
1170 
1171   /* set MatInfo */
1172   afill = (PetscReal)ci[am]/PetscMax(ai[am]+bi[bm],1) + 1.e-5;
1173   if (afill < 1.0) afill = 1.0;
1174   c->maxnz                  = ci[am];
1175   c->nz                     = ci[am];
1176   C->info.mallocs           = ndouble;
1177   C->info.fill_ratio_given  = fill;
1178   C->info.fill_ratio_needed = afill;
1179 
1180 #if defined(PETSC_USE_INFO)
1181   if (ci[am]) {
1182     ierr = PetscInfo3(C,"Reallocs %D; Fill ratio: given %g needed %g.\n",ndouble,(double)fill,(double)afill);CHKERRQ(ierr);
1183     ierr = PetscInfo1(C,"Use MatMatMult(A,B,MatReuse,%g,&C) for best performance.;\n",(double)afill);CHKERRQ(ierr);
1184   } else {
1185     ierr = PetscInfo(C,"Empty matrix product\n");CHKERRQ(ierr);
1186   }
1187 #endif
1188   PetscFunctionReturn(0);
1189 }
1190 
1191 PetscErrorCode MatDestroy_SeqAIJ_MatMatMultTrans(void *data)
1192 {
1193   PetscErrorCode      ierr;
1194   Mat_MatMatTransMult *abt=(Mat_MatMatTransMult *)data;
1195 
1196   PetscFunctionBegin;
1197   ierr = MatTransposeColoringDestroy(&abt->matcoloring);CHKERRQ(ierr);
1198   ierr = MatDestroy(&abt->Bt_den);CHKERRQ(ierr);
1199   ierr = MatDestroy(&abt->ABt_den);CHKERRQ(ierr);
1200   ierr = PetscFree(abt);CHKERRQ(ierr);
1201   PetscFunctionReturn(0);
1202 }
1203 
1204 PetscErrorCode MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat C)
1205 {
1206   PetscErrorCode      ierr;
1207   Mat                 Bt;
1208   PetscInt            *bti,*btj;
1209   Mat_MatMatTransMult *abt;
1210   Mat_Product         *product = C->product;
1211   char                *alg;
1212 
1213   PetscFunctionBegin;
1214   if (!product) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing product struct");
1215   if (product->data) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Extra product struct not empty");
1216 
1217   /* create symbolic Bt */
1218   ierr = MatGetSymbolicTranspose_SeqAIJ(B,&bti,&btj);CHKERRQ(ierr);
1219   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,B->cmap->n,B->rmap->n,bti,btj,NULL,&Bt);CHKERRQ(ierr);
1220   ierr = MatSetBlockSizes(Bt,PetscAbs(A->cmap->bs),PetscAbs(B->cmap->bs));CHKERRQ(ierr);
1221   ierr = MatSetType(Bt,((PetscObject)A)->type_name);CHKERRQ(ierr);
1222 
1223   /* get symbolic C=A*Bt */
1224   ierr = PetscStrallocpy(product->alg,&alg);CHKERRQ(ierr);
1225   ierr = MatProductSetAlgorithm(C,"sorted");CHKERRQ(ierr); /* set algorithm for C = A*Bt */
1226   ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(A,Bt,fill,C);CHKERRQ(ierr);
1227   ierr = MatProductSetAlgorithm(C,alg);CHKERRQ(ierr); /* resume original algorithm for ABt product */
1228   ierr = PetscFree(alg);CHKERRQ(ierr);
1229 
1230   /* create a supporting struct for reuse intermidiate dense matrices with matcoloring */
1231   ierr = PetscNew(&abt);CHKERRQ(ierr);
1232 
1233   product->data    = abt;
1234   product->destroy = MatDestroy_SeqAIJ_MatMatMultTrans;
1235 
1236   C->ops->mattransposemultnumeric = MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ;
1237 
1238   abt->usecoloring = PETSC_FALSE;
1239   ierr = PetscStrcmp(product->alg,"color",&abt->usecoloring);CHKERRQ(ierr);
1240   if (abt->usecoloring) {
1241     /* Create MatTransposeColoring from symbolic C=A*B^T */
1242     MatTransposeColoring matcoloring;
1243     MatColoring          coloring;
1244     ISColoring           iscoloring;
1245     Mat                  Bt_dense,C_dense;
1246 
1247     /* inode causes memory problem */
1248     ierr = MatSetOption(C,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
1249 
1250     ierr = MatColoringCreate(C,&coloring);CHKERRQ(ierr);
1251     ierr = MatColoringSetDistance(coloring,2);CHKERRQ(ierr);
1252     ierr = MatColoringSetType(coloring,MATCOLORINGSL);CHKERRQ(ierr);
1253     ierr = MatColoringSetFromOptions(coloring);CHKERRQ(ierr);
1254     ierr = MatColoringApply(coloring,&iscoloring);CHKERRQ(ierr);
1255     ierr = MatColoringDestroy(&coloring);CHKERRQ(ierr);
1256     ierr = MatTransposeColoringCreate(C,iscoloring,&matcoloring);CHKERRQ(ierr);
1257 
1258     abt->matcoloring = matcoloring;
1259 
1260     ierr = ISColoringDestroy(&iscoloring);CHKERRQ(ierr);
1261 
1262     /* Create Bt_dense and C_dense = A*Bt_dense */
1263     ierr = MatCreate(PETSC_COMM_SELF,&Bt_dense);CHKERRQ(ierr);
1264     ierr = MatSetSizes(Bt_dense,A->cmap->n,matcoloring->ncolors,A->cmap->n,matcoloring->ncolors);CHKERRQ(ierr);
1265     ierr = MatSetType(Bt_dense,MATSEQDENSE);CHKERRQ(ierr);
1266     ierr = MatSeqDenseSetPreallocation(Bt_dense,NULL);CHKERRQ(ierr);
1267 
1268     Bt_dense->assembled = PETSC_TRUE;
1269     abt->Bt_den         = Bt_dense;
1270 
1271     ierr = MatCreate(PETSC_COMM_SELF,&C_dense);CHKERRQ(ierr);
1272     ierr = MatSetSizes(C_dense,A->rmap->n,matcoloring->ncolors,A->rmap->n,matcoloring->ncolors);CHKERRQ(ierr);
1273     ierr = MatSetType(C_dense,MATSEQDENSE);CHKERRQ(ierr);
1274     ierr = MatSeqDenseSetPreallocation(C_dense,NULL);CHKERRQ(ierr);
1275 
1276     Bt_dense->assembled = PETSC_TRUE;
1277     abt->ABt_den  = C_dense;
1278 
1279 #if defined(PETSC_USE_INFO)
1280     {
1281       Mat_SeqAIJ *c = (Mat_SeqAIJ*)C->data;
1282       ierr = PetscInfo7(C,"Use coloring of C=A*B^T; B^T: %D %D, Bt_dense: %D,%D; Cnz %D / (cm*ncolors %D) = %g\n",B->cmap->n,B->rmap->n,Bt_dense->rmap->n,Bt_dense->cmap->n,c->nz,A->rmap->n*matcoloring->ncolors,(PetscReal)(c->nz)/(A->rmap->n*matcoloring->ncolors));CHKERRQ(ierr);
1283     }
1284 #endif
1285   }
1286   /* clean up */
1287   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
1288   ierr = MatRestoreSymbolicTranspose_SeqAIJ(B,&bti,&btj);CHKERRQ(ierr);
1289   PetscFunctionReturn(0);
1290 }
1291 
1292 PetscErrorCode MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
1293 {
1294   PetscErrorCode      ierr;
1295   Mat_SeqAIJ          *a   =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c=(Mat_SeqAIJ*)C->data;
1296   PetscInt            *ai  =a->i,*aj=a->j,*bi=b->i,*bj=b->j,anzi,bnzj,nexta,nextb,*acol,*bcol,brow;
1297   PetscInt            cm   =C->rmap->n,*ci=c->i,*cj=c->j,i,j,cnzi,*ccol;
1298   PetscLogDouble      flops=0.0;
1299   MatScalar           *aa  =a->a,*aval,*ba=b->a,*bval,*ca,*cval;
1300   Mat_MatMatTransMult *abt;
1301   Mat_Product         *product = C->product;
1302 
1303   PetscFunctionBegin;
1304   if (!product) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing product struct");
1305   abt = (Mat_MatMatTransMult *)product->data;
1306   if (!abt) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing product struct");
1307   /* clear old values in C */
1308   if (!c->a) {
1309     ierr      = PetscCalloc1(ci[cm]+1,&ca);CHKERRQ(ierr);
1310     c->a      = ca;
1311     c->free_a = PETSC_TRUE;
1312   } else {
1313     ca =  c->a;
1314     ierr = PetscArrayzero(ca,ci[cm]+1);CHKERRQ(ierr);
1315   }
1316 
1317   if (abt->usecoloring) {
1318     MatTransposeColoring matcoloring = abt->matcoloring;
1319     Mat                  Bt_dense,C_dense = abt->ABt_den;
1320 
1321     /* Get Bt_dense by Apply MatTransposeColoring to B */
1322     Bt_dense = abt->Bt_den;
1323     ierr = MatTransColoringApplySpToDen(matcoloring,B,Bt_dense);CHKERRQ(ierr);
1324 
1325     /* C_dense = A*Bt_dense */
1326     ierr = MatMatMultNumeric_SeqAIJ_SeqDense(A,Bt_dense,C_dense);CHKERRQ(ierr);
1327 
1328     /* Recover C from C_dense */
1329     ierr = MatTransColoringApplyDenToSp(matcoloring,C_dense,C);CHKERRQ(ierr);
1330     PetscFunctionReturn(0);
1331   }
1332 
1333   for (i=0; i<cm; i++) {
1334     anzi = ai[i+1] - ai[i];
1335     acol = aj + ai[i];
1336     aval = aa + ai[i];
1337     cnzi = ci[i+1] - ci[i];
1338     ccol = cj + ci[i];
1339     cval = ca + ci[i];
1340     for (j=0; j<cnzi; j++) {
1341       brow = ccol[j];
1342       bnzj = bi[brow+1] - bi[brow];
1343       bcol = bj + bi[brow];
1344       bval = ba + bi[brow];
1345 
1346       /* perform sparse inner-product c(i,j)=A[i,:]*B[j,:]^T */
1347       nexta = 0; nextb = 0;
1348       while (nexta<anzi && nextb<bnzj) {
1349         while (nexta < anzi && acol[nexta] < bcol[nextb]) nexta++;
1350         if (nexta == anzi) break;
1351         while (nextb < bnzj && acol[nexta] > bcol[nextb]) nextb++;
1352         if (nextb == bnzj) break;
1353         if (acol[nexta] == bcol[nextb]) {
1354           cval[j] += aval[nexta]*bval[nextb];
1355           nexta++; nextb++;
1356           flops += 2;
1357         }
1358       }
1359     }
1360   }
1361   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1362   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1363   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
1364   PetscFunctionReturn(0);
1365 }
1366 
1367 PetscErrorCode MatDestroy_SeqAIJ_MatTransMatMult(void *data)
1368 {
1369   PetscErrorCode      ierr;
1370   Mat_MatTransMatMult *atb = (Mat_MatTransMatMult*)data;
1371 
1372   PetscFunctionBegin;
1373   ierr = MatDestroy(&atb->At);CHKERRQ(ierr);
1374   if (atb->destroy) {
1375     ierr = (*atb->destroy)(atb->data);CHKERRQ(ierr);
1376   }
1377   ierr = PetscFree(atb);CHKERRQ(ierr);
1378   PetscFunctionReturn(0);
1379 }
1380 
1381 PetscErrorCode MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat C)
1382 {
1383   PetscErrorCode ierr;
1384   Mat            At = NULL;
1385   PetscInt       *ati,*atj;
1386   Mat_Product    *product = C->product;
1387   PetscBool      flg,def,square;
1388 
1389   PetscFunctionBegin;
1390   MatCheckProduct(C,4);
1391   square = (PetscBool)(A == B && A->symmetric && A->symmetric_set);
1392   /* outerproduct */
1393   ierr = PetscStrcmp(product->alg,"outerproduct",&flg);CHKERRQ(ierr);
1394   if (flg) {
1395     /* create symbolic At */
1396     if (!square) {
1397       ierr = MatGetSymbolicTranspose_SeqAIJ(A,&ati,&atj);CHKERRQ(ierr);
1398       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,A->cmap->n,A->rmap->n,ati,atj,NULL,&At);CHKERRQ(ierr);
1399       ierr = MatSetBlockSizes(At,PetscAbs(A->cmap->bs),PetscAbs(B->cmap->bs));CHKERRQ(ierr);
1400       ierr = MatSetType(At,((PetscObject)A)->type_name);CHKERRQ(ierr);
1401     }
1402     /* get symbolic C=At*B */
1403     ierr = MatProductSetAlgorithm(C,"sorted");CHKERRQ(ierr);
1404     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(square ? A : At,B,fill,C);CHKERRQ(ierr);
1405 
1406     /* clean up */
1407     if (!square) {
1408       ierr = MatDestroy(&At);CHKERRQ(ierr);
1409       ierr = MatRestoreSymbolicTranspose_SeqAIJ(A,&ati,&atj);CHKERRQ(ierr);
1410     }
1411 
1412     C->ops->mattransposemultnumeric = MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ; /* outerproduct */
1413     ierr = MatProductSetAlgorithm(C,"outerproduct");CHKERRQ(ierr);
1414     PetscFunctionReturn(0);
1415   }
1416 
1417   /* matmatmult */
1418   ierr = PetscStrcmp(product->alg,"default",&def);CHKERRQ(ierr);
1419   ierr = PetscStrcmp(product->alg,"at*b",&flg);CHKERRQ(ierr);
1420   if (flg || def) {
1421     Mat_MatTransMatMult *atb;
1422 
1423     if (product->data) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Extra product struct not empty");
1424     ierr = PetscNew(&atb);CHKERRQ(ierr);
1425     if (!square) {
1426       ierr = MatTranspose_SeqAIJ(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
1427     }
1428     ierr = MatProductSetAlgorithm(C,"sorted");CHKERRQ(ierr);
1429     ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(square ? A : At,B,fill,C);CHKERRQ(ierr);
1430     ierr = MatProductSetAlgorithm(C,"at*b");CHKERRQ(ierr);
1431     product->data    = atb;
1432     product->destroy = MatDestroy_SeqAIJ_MatTransMatMult;
1433     atb->At          = At;
1434     atb->updateAt    = PETSC_FALSE; /* because At is computed here */
1435 
1436     C->ops->mattransposemultnumeric = NULL; /* see MatProductNumeric_AtB_SeqAIJ_SeqAIJ */
1437     PetscFunctionReturn(0);
1438   }
1439 
1440   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Mat Product Algorithm is not supported");
1441 }
1442 
1443 PetscErrorCode MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
1444 {
1445   PetscErrorCode ierr;
1446   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c=(Mat_SeqAIJ*)C->data;
1447   PetscInt       am=A->rmap->n,anzi,*ai=a->i,*aj=a->j,*bi=b->i,*bj,bnzi,nextb;
1448   PetscInt       cm=C->rmap->n,*ci=c->i,*cj=c->j,crow,*cjj,i,j,k;
1449   PetscLogDouble flops=0.0;
1450   MatScalar      *aa=a->a,*ba,*ca,*caj;
1451 
1452   PetscFunctionBegin;
1453   if (!c->a) {
1454     ierr = PetscCalloc1(ci[cm]+1,&ca);CHKERRQ(ierr);
1455 
1456     c->a      = ca;
1457     c->free_a = PETSC_TRUE;
1458   } else {
1459     ca   = c->a;
1460     ierr = PetscArrayzero(ca,ci[cm]);CHKERRQ(ierr);
1461   }
1462 
1463   /* compute A^T*B using outer product (A^T)[:,i]*B[i,:] */
1464   for (i=0; i<am; i++) {
1465     bj   = b->j + bi[i];
1466     ba   = b->a + bi[i];
1467     bnzi = bi[i+1] - bi[i];
1468     anzi = ai[i+1] - ai[i];
1469     for (j=0; j<anzi; j++) {
1470       nextb = 0;
1471       crow  = *aj++;
1472       cjj   = cj + ci[crow];
1473       caj   = ca + ci[crow];
1474       /* perform sparse axpy operation.  Note cjj includes bj. */
1475       for (k=0; nextb<bnzi; k++) {
1476         if (cjj[k] == *(bj+nextb)) { /* ccol == bcol */
1477           caj[k] += (*aa)*(*(ba+nextb));
1478           nextb++;
1479         }
1480       }
1481       flops += 2*bnzi;
1482       aa++;
1483     }
1484   }
1485 
1486   /* Assemble the final matrix and clean up */
1487   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1488   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1489   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
1490   PetscFunctionReturn(0);
1491 }
1492 
1493 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqDense(Mat A,Mat B,PetscReal fill,Mat C)
1494 {
1495   PetscErrorCode ierr;
1496 
1497   PetscFunctionBegin;
1498   ierr = MatMatMultSymbolic_SeqDense_SeqDense(A,B,0.0,C);CHKERRQ(ierr);
1499   C->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqDense;
1500   PetscFunctionReturn(0);
1501 }
1502 
1503 PETSC_INTERN PetscErrorCode MatMatMultNumericAdd_SeqAIJ_SeqDense(Mat A,Mat B,Mat C,const PetscBool add)
1504 {
1505   Mat_SeqAIJ        *a=(Mat_SeqAIJ*)A->data;
1506   Mat_SeqDense      *bd=(Mat_SeqDense*)B->data;
1507   Mat_SeqDense      *cd=(Mat_SeqDense*)C->data;
1508   PetscErrorCode    ierr;
1509   PetscScalar       *c,r1,r2,r3,r4,*c1,*c2,*c3,*c4;
1510   const PetscScalar *aa,*b,*b1,*b2,*b3,*b4,*av;
1511   const PetscInt    *aj;
1512   PetscInt          cm=C->rmap->n,cn=B->cmap->n,bm=bd->lda,am=A->rmap->n;
1513   PetscInt          clda=cd->lda;
1514   PetscInt          am4=4*clda,bm4=4*bm,col,i,j,n;
1515 
1516   PetscFunctionBegin;
1517   if (!cm || !cn) PetscFunctionReturn(0);
1518   ierr = MatSeqAIJGetArrayRead(A,&av);CHKERRQ(ierr);
1519   if (add) {
1520     ierr = MatDenseGetArray(C,&c);CHKERRQ(ierr);
1521   } else {
1522     ierr = MatDenseGetArrayWrite(C,&c);CHKERRQ(ierr);
1523   }
1524   ierr = MatDenseGetArrayRead(B,&b);CHKERRQ(ierr);
1525   b1 = b; b2 = b1 + bm; b3 = b2 + bm; b4 = b3 + bm;
1526   c1 = c; c2 = c1 + clda; c3 = c2 + clda; c4 = c3 + clda;
1527   for (col=0; col<(cn/4)*4; col += 4) {  /* over columns of C */
1528     for (i=0; i<am; i++) {        /* over rows of A in those columns */
1529       r1 = r2 = r3 = r4 = 0.0;
1530       n  = a->i[i+1] - a->i[i];
1531       aj = a->j + a->i[i];
1532       aa = av + a->i[i];
1533       for (j=0; j<n; j++) {
1534         const PetscScalar aatmp = aa[j];
1535         const PetscInt    ajtmp = aj[j];
1536         r1 += aatmp*b1[ajtmp];
1537         r2 += aatmp*b2[ajtmp];
1538         r3 += aatmp*b3[ajtmp];
1539         r4 += aatmp*b4[ajtmp];
1540       }
1541       if (add) {
1542         c1[i] += r1;
1543         c2[i] += r2;
1544         c3[i] += r3;
1545         c4[i] += r4;
1546       } else {
1547         c1[i] = r1;
1548         c2[i] = r2;
1549         c3[i] = r3;
1550         c4[i] = r4;
1551       }
1552     }
1553     b1 += bm4; b2 += bm4; b3 += bm4; b4 += bm4;
1554     c1 += am4; c2 += am4; c3 += am4; c4 += am4;
1555   }
1556   /* process remaining columns */
1557   if (col != cn) {
1558     PetscInt rc = cn-col;
1559 
1560     if (rc == 1) {
1561       for (i=0; i<am; i++) {
1562         r1 = 0.0;
1563         n  = a->i[i+1] - a->i[i];
1564         aj = a->j + a->i[i];
1565         aa = av + a->i[i];
1566         for (j=0; j<n; j++) r1 += aa[j]*b1[aj[j]];
1567         if (add) c1[i] += r1;
1568         else c1[i] = r1;
1569       }
1570     } else if (rc == 2) {
1571       for (i=0; i<am; i++) {
1572         r1 = r2 = 0.0;
1573         n  = a->i[i+1] - a->i[i];
1574         aj = a->j + a->i[i];
1575         aa = av + a->i[i];
1576         for (j=0; j<n; j++) {
1577           const PetscScalar aatmp = aa[j];
1578           const PetscInt    ajtmp = aj[j];
1579           r1 += aatmp*b1[ajtmp];
1580           r2 += aatmp*b2[ajtmp];
1581         }
1582         if (add) {
1583           c1[i] += r1;
1584           c2[i] += r2;
1585         } else {
1586           c1[i] = r1;
1587           c2[i] = r2;
1588         }
1589       }
1590     } else {
1591       for (i=0; i<am; i++) {
1592         r1 = r2 = r3 = 0.0;
1593         n  = a->i[i+1] - a->i[i];
1594         aj = a->j + a->i[i];
1595         aa = av + a->i[i];
1596         for (j=0; j<n; j++) {
1597           const PetscScalar aatmp = aa[j];
1598           const PetscInt    ajtmp = aj[j];
1599           r1 += aatmp*b1[ajtmp];
1600           r2 += aatmp*b2[ajtmp];
1601           r3 += aatmp*b3[ajtmp];
1602         }
1603         if (add) {
1604           c1[i] += r1;
1605           c2[i] += r2;
1606           c3[i] += r3;
1607         } else {
1608           c1[i] = r1;
1609           c2[i] = r2;
1610           c3[i] = r3;
1611         }
1612       }
1613     }
1614   }
1615   ierr = PetscLogFlops(cn*(2.0*a->nz));CHKERRQ(ierr);
1616   if (add) {
1617     ierr = MatDenseRestoreArray(C,&c);CHKERRQ(ierr);
1618   } else {
1619     ierr = MatDenseRestoreArrayWrite(C,&c);CHKERRQ(ierr);
1620   }
1621   ierr = MatDenseRestoreArrayRead(B,&b);CHKERRQ(ierr);
1622   ierr = MatSeqAIJRestoreArrayRead(A,&av);CHKERRQ(ierr);
1623   PetscFunctionReturn(0);
1624 }
1625 
1626 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqDense(Mat A,Mat B,Mat C)
1627 {
1628   PetscErrorCode ierr;
1629 
1630   PetscFunctionBegin;
1631   if (B->rmap->n != A->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number columns in A %D not equal rows in B %D\n",A->cmap->n,B->rmap->n);
1632   if (A->rmap->n != C->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number rows in C %D not equal rows in A %D\n",C->rmap->n,A->rmap->n);
1633   if (B->cmap->n != C->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number columns in B %D not equal columns in C %D\n",B->cmap->n,C->cmap->n);
1634 
1635   ierr = MatMatMultNumericAdd_SeqAIJ_SeqDense(A,B,C,PETSC_FALSE);CHKERRQ(ierr);
1636   PetscFunctionReturn(0);
1637 }
1638 
1639 /* ------------------------------------------------------- */
1640 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_SeqDense_AB(Mat C)
1641 {
1642   PetscFunctionBegin;
1643   C->ops->matmultsymbolic = MatMatMultSymbolic_SeqAIJ_SeqDense;
1644   C->ops->productsymbolic = MatProductSymbolic_AB;
1645   PetscFunctionReturn(0);
1646 }
1647 
1648 PETSC_INTERN PetscErrorCode MatTMatTMultSymbolic_SeqAIJ_SeqDense(Mat,Mat,PetscReal,Mat);
1649 
1650 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_SeqDense_AtB(Mat C)
1651 {
1652   PetscFunctionBegin;
1653   C->ops->transposematmultsymbolic = MatTMatTMultSymbolic_SeqAIJ_SeqDense;
1654   C->ops->productsymbolic          = MatProductSymbolic_AtB;
1655   PetscFunctionReturn(0);
1656 }
1657 
1658 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_SeqDense_ABt(Mat C)
1659 {
1660   PetscFunctionBegin;
1661   C->ops->mattransposemultsymbolic = MatTMatTMultSymbolic_SeqAIJ_SeqDense;
1662   C->ops->productsymbolic          = MatProductSymbolic_ABt;
1663   PetscFunctionReturn(0);
1664 }
1665 
1666 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_SeqAIJ_SeqDense(Mat C)
1667 {
1668   PetscErrorCode ierr;
1669   Mat_Product    *product = C->product;
1670 
1671   PetscFunctionBegin;
1672   switch (product->type) {
1673   case MATPRODUCT_AB:
1674     ierr = MatProductSetFromOptions_SeqAIJ_SeqDense_AB(C);CHKERRQ(ierr);
1675     break;
1676   case MATPRODUCT_AtB:
1677     ierr = MatProductSetFromOptions_SeqAIJ_SeqDense_AtB(C);CHKERRQ(ierr);
1678     break;
1679   case MATPRODUCT_ABt:
1680     ierr = MatProductSetFromOptions_SeqAIJ_SeqDense_ABt(C);CHKERRQ(ierr);
1681     break;
1682   default:
1683     break;
1684   }
1685   PetscFunctionReturn(0);
1686 }
1687 /* ------------------------------------------------------- */
1688 static PetscErrorCode MatProductSetFromOptions_SeqXBAIJ_SeqDense_AB(Mat C)
1689 {
1690   PetscErrorCode ierr;
1691   Mat_Product    *product = C->product;
1692   Mat            A = product->A;
1693   PetscBool      baij;
1694 
1695   PetscFunctionBegin;
1696   ierr = PetscObjectTypeCompare((PetscObject)A,MATSEQBAIJ,&baij);CHKERRQ(ierr);
1697   if (!baij) { /* A is seqsbaij */
1698     PetscBool sbaij;
1699     ierr = PetscObjectTypeCompare((PetscObject)A,MATSEQSBAIJ,&sbaij);CHKERRQ(ierr);
1700     if (!sbaij) SETERRQ(PetscObjectComm((PetscObject)C),PETSC_ERR_ARG_WRONGSTATE,"Mat must be either seqbaij or seqsbaij format");
1701 
1702     C->ops->matmultsymbolic = MatMatMultSymbolic_SeqSBAIJ_SeqDense;
1703   } else { /* A is seqbaij */
1704     C->ops->matmultsymbolic = MatMatMultSymbolic_SeqBAIJ_SeqDense;
1705   }
1706 
1707   C->ops->productsymbolic = MatProductSymbolic_AB;
1708   PetscFunctionReturn(0);
1709 }
1710 
1711 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_SeqXBAIJ_SeqDense(Mat C)
1712 {
1713   PetscErrorCode ierr;
1714   Mat_Product    *product = C->product;
1715 
1716   PetscFunctionBegin;
1717   MatCheckProduct(C,1);
1718   if (!product->A) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing A");
1719   if (product->type == MATPRODUCT_AB || (product->type == MATPRODUCT_AtB && product->A->symmetric)) {
1720     ierr = MatProductSetFromOptions_SeqXBAIJ_SeqDense_AB(C);CHKERRQ(ierr);
1721   }
1722   PetscFunctionReturn(0);
1723 }
1724 
1725 /* ------------------------------------------------------- */
1726 static PetscErrorCode MatProductSetFromOptions_SeqDense_SeqAIJ_AB(Mat C)
1727 {
1728   PetscFunctionBegin;
1729   C->ops->matmultsymbolic = MatMatMultSymbolic_SeqDense_SeqAIJ;
1730   C->ops->productsymbolic = MatProductSymbolic_AB;
1731   PetscFunctionReturn(0);
1732 }
1733 
1734 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_SeqDense_SeqAIJ(Mat C)
1735 {
1736   PetscErrorCode ierr;
1737   Mat_Product    *product = C->product;
1738 
1739   PetscFunctionBegin;
1740   if (product->type == MATPRODUCT_AB) {
1741     ierr = MatProductSetFromOptions_SeqDense_SeqAIJ_AB(C);CHKERRQ(ierr);
1742   }
1743   PetscFunctionReturn(0);
1744 }
1745 /* ------------------------------------------------------- */
1746 
1747 PetscErrorCode  MatTransColoringApplySpToDen_SeqAIJ(MatTransposeColoring coloring,Mat B,Mat Btdense)
1748 {
1749   PetscErrorCode ierr;
1750   Mat_SeqAIJ     *b       = (Mat_SeqAIJ*)B->data;
1751   Mat_SeqDense   *btdense = (Mat_SeqDense*)Btdense->data;
1752   PetscInt       *bi      = b->i,*bj=b->j;
1753   PetscInt       m        = Btdense->rmap->n,n=Btdense->cmap->n,j,k,l,col,anz,*btcol,brow,ncolumns;
1754   MatScalar      *btval,*btval_den,*ba=b->a;
1755   PetscInt       *columns=coloring->columns,*colorforcol=coloring->colorforcol,ncolors=coloring->ncolors;
1756 
1757   PetscFunctionBegin;
1758   btval_den=btdense->v;
1759   ierr     = PetscArrayzero(btval_den,m*n);CHKERRQ(ierr);
1760   for (k=0; k<ncolors; k++) {
1761     ncolumns = coloring->ncolumns[k];
1762     for (l=0; l<ncolumns; l++) { /* insert a row of B to a column of Btdense */
1763       col   = *(columns + colorforcol[k] + l);
1764       btcol = bj + bi[col];
1765       btval = ba + bi[col];
1766       anz   = bi[col+1] - bi[col];
1767       for (j=0; j<anz; j++) {
1768         brow            = btcol[j];
1769         btval_den[brow] = btval[j];
1770       }
1771     }
1772     btval_den += m;
1773   }
1774   PetscFunctionReturn(0);
1775 }
1776 
1777 PetscErrorCode MatTransColoringApplyDenToSp_SeqAIJ(MatTransposeColoring matcoloring,Mat Cden,Mat Csp)
1778 {
1779   PetscErrorCode    ierr;
1780   Mat_SeqAIJ        *csp = (Mat_SeqAIJ*)Csp->data;
1781   const PetscScalar *ca_den,*ca_den_ptr;
1782   PetscScalar       *ca=csp->a;
1783   PetscInt          k,l,m=Cden->rmap->n,ncolors=matcoloring->ncolors;
1784   PetscInt          brows=matcoloring->brows,*den2sp=matcoloring->den2sp;
1785   PetscInt          nrows,*row,*idx;
1786   PetscInt          *rows=matcoloring->rows,*colorforrow=matcoloring->colorforrow;
1787 
1788   PetscFunctionBegin;
1789   ierr   = MatDenseGetArrayRead(Cden,&ca_den);CHKERRQ(ierr);
1790 
1791   if (brows > 0) {
1792     PetscInt *lstart,row_end,row_start;
1793     lstart = matcoloring->lstart;
1794     ierr = PetscArrayzero(lstart,ncolors);CHKERRQ(ierr);
1795 
1796     row_end = brows;
1797     if (row_end > m) row_end = m;
1798     for (row_start=0; row_start<m; row_start+=brows) { /* loop over row blocks of Csp */
1799       ca_den_ptr = ca_den;
1800       for (k=0; k<ncolors; k++) { /* loop over colors (columns of Cden) */
1801         nrows = matcoloring->nrows[k];
1802         row   = rows  + colorforrow[k];
1803         idx   = den2sp + colorforrow[k];
1804         for (l=lstart[k]; l<nrows; l++) {
1805           if (row[l] >= row_end) {
1806             lstart[k] = l;
1807             break;
1808           } else {
1809             ca[idx[l]] = ca_den_ptr[row[l]];
1810           }
1811         }
1812         ca_den_ptr += m;
1813       }
1814       row_end += brows;
1815       if (row_end > m) row_end = m;
1816     }
1817   } else { /* non-blocked impl: loop over columns of Csp - slow if Csp is large */
1818     ca_den_ptr = ca_den;
1819     for (k=0; k<ncolors; k++) {
1820       nrows = matcoloring->nrows[k];
1821       row   = rows  + colorforrow[k];
1822       idx   = den2sp + colorforrow[k];
1823       for (l=0; l<nrows; l++) {
1824         ca[idx[l]] = ca_den_ptr[row[l]];
1825       }
1826       ca_den_ptr += m;
1827     }
1828   }
1829 
1830   ierr = MatDenseRestoreArrayRead(Cden,&ca_den);CHKERRQ(ierr);
1831 #if defined(PETSC_USE_INFO)
1832   if (matcoloring->brows > 0) {
1833     ierr = PetscInfo1(Csp,"Loop over %D row blocks for den2sp\n",brows);CHKERRQ(ierr);
1834   } else {
1835     ierr = PetscInfo(Csp,"Loop over colors/columns of Cden, inefficient for large sparse matrix product \n");CHKERRQ(ierr);
1836   }
1837 #endif
1838   PetscFunctionReturn(0);
1839 }
1840 
1841 PetscErrorCode MatTransposeColoringCreate_SeqAIJ(Mat mat,ISColoring iscoloring,MatTransposeColoring c)
1842 {
1843   PetscErrorCode ierr;
1844   PetscInt       i,n,nrows,Nbs,j,k,m,ncols,col,cm;
1845   const PetscInt *is,*ci,*cj,*row_idx;
1846   PetscInt       nis = iscoloring->n,*rowhit,bs = 1;
1847   IS             *isa;
1848   Mat_SeqAIJ     *csp = (Mat_SeqAIJ*)mat->data;
1849   PetscInt       *colorforrow,*rows,*rows_i,*idxhit,*spidx,*den2sp,*den2sp_i;
1850   PetscInt       *colorforcol,*columns,*columns_i,brows;
1851   PetscBool      flg;
1852 
1853   PetscFunctionBegin;
1854   ierr = ISColoringGetIS(iscoloring,PETSC_USE_POINTER,PETSC_IGNORE,&isa);CHKERRQ(ierr);
1855 
1856   /* bs >1 is not being tested yet! */
1857   Nbs       = mat->cmap->N/bs;
1858   c->M      = mat->rmap->N/bs;  /* set total rows, columns and local rows */
1859   c->N      = Nbs;
1860   c->m      = c->M;
1861   c->rstart = 0;
1862   c->brows  = 100;
1863 
1864   c->ncolors = nis;
1865   ierr = PetscMalloc3(nis,&c->ncolumns,nis,&c->nrows,nis+1,&colorforrow);CHKERRQ(ierr);
1866   ierr = PetscMalloc1(csp->nz+1,&rows);CHKERRQ(ierr);
1867   ierr = PetscMalloc1(csp->nz+1,&den2sp);CHKERRQ(ierr);
1868 
1869   brows = c->brows;
1870   ierr = PetscOptionsGetInt(NULL,NULL,"-matden2sp_brows",&brows,&flg);CHKERRQ(ierr);
1871   if (flg) c->brows = brows;
1872   if (brows > 0) {
1873     ierr = PetscMalloc1(nis+1,&c->lstart);CHKERRQ(ierr);
1874   }
1875 
1876   colorforrow[0] = 0;
1877   rows_i         = rows;
1878   den2sp_i       = den2sp;
1879 
1880   ierr = PetscMalloc1(nis+1,&colorforcol);CHKERRQ(ierr);
1881   ierr = PetscMalloc1(Nbs+1,&columns);CHKERRQ(ierr);
1882 
1883   colorforcol[0] = 0;
1884   columns_i      = columns;
1885 
1886   /* get column-wise storage of mat */
1887   ierr = MatGetColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
1888 
1889   cm   = c->m;
1890   ierr = PetscMalloc1(cm+1,&rowhit);CHKERRQ(ierr);
1891   ierr = PetscMalloc1(cm+1,&idxhit);CHKERRQ(ierr);
1892   for (i=0; i<nis; i++) { /* loop over color */
1893     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
1894     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
1895 
1896     c->ncolumns[i] = n;
1897     if (n) {
1898       ierr = PetscArraycpy(columns_i,is,n);CHKERRQ(ierr);
1899     }
1900     colorforcol[i+1] = colorforcol[i] + n;
1901     columns_i       += n;
1902 
1903     /* fast, crude version requires O(N*N) work */
1904     ierr = PetscArrayzero(rowhit,cm);CHKERRQ(ierr);
1905 
1906     for (j=0; j<n; j++) { /* loop over columns*/
1907       col     = is[j];
1908       row_idx = cj + ci[col];
1909       m       = ci[col+1] - ci[col];
1910       for (k=0; k<m; k++) { /* loop over columns marking them in rowhit */
1911         idxhit[*row_idx]   = spidx[ci[col] + k];
1912         rowhit[*row_idx++] = col + 1;
1913       }
1914     }
1915     /* count the number of hits */
1916     nrows = 0;
1917     for (j=0; j<cm; j++) {
1918       if (rowhit[j]) nrows++;
1919     }
1920     c->nrows[i]      = nrows;
1921     colorforrow[i+1] = colorforrow[i] + nrows;
1922 
1923     nrows = 0;
1924     for (j=0; j<cm; j++) { /* loop over rows */
1925       if (rowhit[j]) {
1926         rows_i[nrows]   = j;
1927         den2sp_i[nrows] = idxhit[j];
1928         nrows++;
1929       }
1930     }
1931     den2sp_i += nrows;
1932 
1933     ierr    = ISRestoreIndices(isa[i],&is);CHKERRQ(ierr);
1934     rows_i += nrows;
1935   }
1936   ierr = MatRestoreColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
1937   ierr = PetscFree(rowhit);CHKERRQ(ierr);
1938   ierr = ISColoringRestoreIS(iscoloring,PETSC_USE_POINTER,&isa);CHKERRQ(ierr);
1939   if (csp->nz != colorforrow[nis]) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"csp->nz %d != colorforrow[nis] %d",csp->nz,colorforrow[nis]);
1940 
1941   c->colorforrow = colorforrow;
1942   c->rows        = rows;
1943   c->den2sp      = den2sp;
1944   c->colorforcol = colorforcol;
1945   c->columns     = columns;
1946 
1947   ierr = PetscFree(idxhit);CHKERRQ(ierr);
1948   PetscFunctionReturn(0);
1949 }
1950 
1951 /* --------------------------------------------------------------- */
1952 static PetscErrorCode MatProductNumeric_AtB_SeqAIJ_SeqAIJ(Mat C)
1953 {
1954   PetscErrorCode ierr;
1955   Mat_Product    *product = C->product;
1956   Mat            A=product->A,B=product->B;
1957 
1958   PetscFunctionBegin;
1959   if (C->ops->mattransposemultnumeric) {
1960     /* Alg: "outerproduct" */
1961     ierr = (*C->ops->mattransposemultnumeric)(A,B,C);CHKERRQ(ierr);
1962   } else {
1963     /* Alg: "matmatmult" -- C = At*B */
1964     Mat_MatTransMatMult *atb = (Mat_MatTransMatMult *)product->data;
1965     Mat                 At;
1966 
1967     if (!atb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing product struct");
1968     At = atb->At;
1969     if (atb->updateAt && At) { /* At is computed in MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ() */
1970       ierr = MatTranspose_SeqAIJ(A,MAT_REUSE_MATRIX,&At);CHKERRQ(ierr);
1971     }
1972     ierr = MatMatMultNumeric_SeqAIJ_SeqAIJ(At ? At : A,B,C);CHKERRQ(ierr);
1973     atb->updateAt = PETSC_TRUE;
1974   }
1975   PetscFunctionReturn(0);
1976 }
1977 
1978 static PetscErrorCode MatProductSymbolic_AtB_SeqAIJ_SeqAIJ(Mat C)
1979 {
1980   PetscErrorCode ierr;
1981   Mat_Product    *product = C->product;
1982   Mat            A=product->A,B=product->B;
1983   PetscReal      fill=product->fill;
1984 
1985   PetscFunctionBegin;
1986   ierr = MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ(A,B,fill,C);CHKERRQ(ierr);
1987 
1988   C->ops->productnumeric = MatProductNumeric_AtB_SeqAIJ_SeqAIJ;
1989   PetscFunctionReturn(0);
1990 }
1991 
1992 /* --------------------------------------------------------------- */
1993 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_AB(Mat C)
1994 {
1995   PetscErrorCode ierr;
1996   Mat_Product    *product = C->product;
1997   PetscInt       alg = 0; /* default algorithm */
1998   PetscBool      flg = PETSC_FALSE;
1999 #if !defined(PETSC_HAVE_HYPRE)
2000   const char     *algTypes[7] = {"sorted","scalable","scalable_fast","heap","btheap","llcondensed","rowmerge"};
2001   PetscInt       nalg = 7;
2002 #else
2003   const char     *algTypes[8] = {"sorted","scalable","scalable_fast","heap","btheap","llcondensed","rowmerge","hypre"};
2004   PetscInt       nalg = 8;
2005 #endif
2006 
2007   PetscFunctionBegin;
2008   /* Set default algorithm */
2009   ierr = PetscStrcmp(C->product->alg,"default",&flg);CHKERRQ(ierr);
2010   if (flg) {
2011     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2012   }
2013 
2014   /* Get runtime option */
2015   if (product->api_user) {
2016     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatMatMult","Mat");CHKERRQ(ierr);
2017     ierr = PetscOptionsEList("-matmatmult_via","Algorithmic approach","MatMatMult",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2018     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2019   } else {
2020     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_AB","Mat");CHKERRQ(ierr);
2021     ierr = PetscOptionsEList("-matproduct_ab_via","Algorithmic approach","MatProduct_AB",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2022     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2023   }
2024   if (flg) {
2025     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2026   }
2027 
2028   C->ops->productsymbolic = MatProductSymbolic_AB;
2029   C->ops->matmultsymbolic = MatMatMultSymbolic_SeqAIJ_SeqAIJ;
2030   PetscFunctionReturn(0);
2031 }
2032 
2033 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_AtB(Mat C)
2034 {
2035   PetscErrorCode ierr;
2036   Mat_Product    *product = C->product;
2037   PetscInt       alg = 0; /* default algorithm */
2038   PetscBool      flg = PETSC_FALSE;
2039   const char     *algTypes[3] = {"default","at*b","outerproduct"};
2040   PetscInt       nalg = 3;
2041 
2042   PetscFunctionBegin;
2043   /* Get runtime option */
2044   if (product->api_user) {
2045     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatTransposeMatMult","Mat");CHKERRQ(ierr);
2046     ierr = PetscOptionsEList("-mattransposematmult_via","Algorithmic approach","MatTransposeMatMult",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2047     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2048   } else {
2049     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_AtB","Mat");CHKERRQ(ierr);
2050     ierr = PetscOptionsEList("-matproduct_atb_via","Algorithmic approach","MatProduct_AtB",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2051     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2052   }
2053   if (flg) {
2054     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2055   }
2056 
2057   C->ops->productsymbolic = MatProductSymbolic_AtB_SeqAIJ_SeqAIJ;
2058   PetscFunctionReturn(0);
2059 }
2060 
2061 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_ABt(Mat C)
2062 {
2063   PetscErrorCode ierr;
2064   Mat_Product    *product = C->product;
2065   PetscInt       alg = 0; /* default algorithm */
2066   PetscBool      flg = PETSC_FALSE;
2067   const char     *algTypes[2] = {"default","color"};
2068   PetscInt       nalg = 2;
2069 
2070   PetscFunctionBegin;
2071   /* Set default algorithm */
2072   ierr = PetscStrcmp(C->product->alg,"default",&flg);CHKERRQ(ierr);
2073   if (!flg) {
2074     alg = 1;
2075     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2076   }
2077 
2078   /* Get runtime option */
2079   if (product->api_user) {
2080     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatMatTransposeMult","Mat");CHKERRQ(ierr);
2081     ierr = PetscOptionsEList("-matmattransmult_via","Algorithmic approach","MatMatTransposeMult",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2082     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2083   } else {
2084     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_ABt","Mat");CHKERRQ(ierr);
2085     ierr = PetscOptionsEList("-matproduct_abt_via","Algorithmic approach","MatProduct_ABt",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2086     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2087   }
2088   if (flg) {
2089     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2090   }
2091 
2092   C->ops->mattransposemultsymbolic = MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ;
2093   C->ops->productsymbolic          = MatProductSymbolic_ABt;
2094   PetscFunctionReturn(0);
2095 }
2096 
2097 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_PtAP(Mat C)
2098 {
2099   PetscErrorCode ierr;
2100   Mat_Product    *product = C->product;
2101   PetscBool      flg = PETSC_FALSE;
2102   PetscInt       alg = 0; /* default algorithm -- alg=1 should be default!!! */
2103 #if !defined(PETSC_HAVE_HYPRE)
2104   const char     *algTypes[2] = {"scalable","rap"};
2105   PetscInt       nalg = 2;
2106 #else
2107   const char     *algTypes[3] = {"scalable","rap","hypre"};
2108   PetscInt       nalg = 3;
2109 #endif
2110 
2111   PetscFunctionBegin;
2112   /* Set default algorithm */
2113   ierr = PetscStrcmp(product->alg,"default",&flg);CHKERRQ(ierr);
2114   if (flg) {
2115     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2116   }
2117 
2118   /* Get runtime option */
2119   if (product->api_user) {
2120     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatPtAP","Mat");CHKERRQ(ierr);
2121     ierr = PetscOptionsEList("-matptap_via","Algorithmic approach","MatPtAP",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2122     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2123   } else {
2124     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_PtAP","Mat");CHKERRQ(ierr);
2125     ierr = PetscOptionsEList("-matproduct_ptap_via","Algorithmic approach","MatProduct_PtAP",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2126     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2127   }
2128   if (flg) {
2129     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2130   }
2131 
2132   C->ops->productsymbolic = MatProductSymbolic_PtAP_SeqAIJ_SeqAIJ;
2133   PetscFunctionReturn(0);
2134 }
2135 
2136 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_RARt(Mat C)
2137 {
2138   PetscErrorCode ierr;
2139   Mat_Product    *product = C->product;
2140   PetscBool      flg = PETSC_FALSE;
2141   PetscInt       alg = 0; /* default algorithm */
2142   const char     *algTypes[3] = {"r*a*rt","r*art","coloring_rart"};
2143   PetscInt        nalg = 3;
2144 
2145   PetscFunctionBegin;
2146   /* Set default algorithm */
2147   ierr = PetscStrcmp(product->alg,"default",&flg);CHKERRQ(ierr);
2148   if (flg) {
2149     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2150   }
2151 
2152   /* Get runtime option */
2153   if (product->api_user) {
2154     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatRARt","Mat");CHKERRQ(ierr);
2155     ierr = PetscOptionsEList("-matrart_via","Algorithmic approach","MatRARt",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2156     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2157   } else {
2158     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_RARt","Mat");CHKERRQ(ierr);
2159     ierr = PetscOptionsEList("-matproduct_rart_via","Algorithmic approach","MatProduct_RARt",algTypes,nalg,algTypes[0],&alg,&flg);CHKERRQ(ierr);
2160     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2161   }
2162   if (flg) {
2163     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2164   }
2165 
2166   C->ops->productsymbolic = MatProductSymbolic_RARt_SeqAIJ_SeqAIJ;
2167   PetscFunctionReturn(0);
2168 }
2169 
2170 /* ABC = A*B*C = A*(B*C); ABC's algorithm must be chosen from AB's algorithm */
2171 static PetscErrorCode MatProductSetFromOptions_SeqAIJ_ABC(Mat C)
2172 {
2173   PetscErrorCode ierr;
2174   Mat_Product    *product = C->product;
2175   PetscInt       alg = 0; /* default algorithm */
2176   PetscBool      flg = PETSC_FALSE;
2177   const char     *algTypes[7] = {"sorted","scalable","scalable_fast","heap","btheap","llcondensed","rowmerge"};
2178   PetscInt       nalg = 7;
2179 
2180   PetscFunctionBegin;
2181   /* Set default algorithm */
2182   ierr = PetscStrcmp(product->alg,"default",&flg);CHKERRQ(ierr);
2183   if (flg) {
2184     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2185   }
2186 
2187   /* Get runtime option */
2188   if (product->api_user) {
2189     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatMatMatMult","Mat");CHKERRQ(ierr);
2190     ierr = PetscOptionsEList("-matmatmatmult_via","Algorithmic approach","MatMatMatMult",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2191     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2192   } else {
2193     ierr = PetscOptionsBegin(PetscObjectComm((PetscObject)C),((PetscObject)C)->prefix,"MatProduct_ABC","Mat");CHKERRQ(ierr);
2194     ierr = PetscOptionsEList("-matproduct_abc_via","Algorithmic approach","MatProduct_ABC",algTypes,nalg,algTypes[alg],&alg,&flg);CHKERRQ(ierr);
2195     ierr = PetscOptionsEnd();CHKERRQ(ierr);
2196   }
2197   if (flg) {
2198     ierr = MatProductSetAlgorithm(C,(MatProductAlgorithm)algTypes[alg]);CHKERRQ(ierr);
2199   }
2200 
2201   C->ops->matmatmultsymbolic = MatMatMatMultSymbolic_SeqAIJ_SeqAIJ_SeqAIJ;
2202   C->ops->productsymbolic    = MatProductSymbolic_ABC;
2203   PetscFunctionReturn(0);
2204 }
2205 
2206 PetscErrorCode MatProductSetFromOptions_SeqAIJ(Mat C)
2207 {
2208   PetscErrorCode ierr;
2209   Mat_Product    *product = C->product;
2210 
2211   PetscFunctionBegin;
2212   switch (product->type) {
2213   case MATPRODUCT_AB:
2214     ierr = MatProductSetFromOptions_SeqAIJ_AB(C);CHKERRQ(ierr);
2215     break;
2216   case MATPRODUCT_AtB:
2217     ierr = MatProductSetFromOptions_SeqAIJ_AtB(C);CHKERRQ(ierr);
2218     break;
2219   case MATPRODUCT_ABt:
2220     ierr = MatProductSetFromOptions_SeqAIJ_ABt(C);CHKERRQ(ierr);
2221     break;
2222   case MATPRODUCT_PtAP:
2223     ierr = MatProductSetFromOptions_SeqAIJ_PtAP(C);CHKERRQ(ierr);
2224     break;
2225   case MATPRODUCT_RARt:
2226     ierr = MatProductSetFromOptions_SeqAIJ_RARt(C);CHKERRQ(ierr);
2227     break;
2228   case MATPRODUCT_ABC:
2229     ierr = MatProductSetFromOptions_SeqAIJ_ABC(C);CHKERRQ(ierr);
2230     break;
2231   default:
2232     break;
2233   }
2234   PetscFunctionReturn(0);
2235 }
2236