xref: /petsc/src/mat/impls/aij/seq/matmatmult.c (revision e3d2fdc1d239ffe0324c17a25371fcbf3b27a61c)
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 <../src/mat/utils/petscheap.h>
10 #include <petscbt.h>
11 #include <../src/mat/impls/dense/seq/dense.h>
12 
13 static PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed(Mat,Mat,PetscReal,Mat*);
14 
15 #undef __FUNCT__
16 #define __FUNCT__ "MatMatMult_SeqAIJ_SeqAIJ"
17 PetscErrorCode MatMatMult_SeqAIJ_SeqAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
18 {
19   PetscErrorCode ierr;
20   PetscBool      scalable=PETSC_FALSE,scalable_fast=PETSC_FALSE,heap = PETSC_FALSE,btheap = PETSC_FALSE,llcondensed = PETSC_FALSE;
21 
22   PetscFunctionBegin;
23   if (scall == MAT_INITIAL_MATRIX) {
24     ierr = PetscObjectOptionsBegin((PetscObject)A);CHKERRQ(ierr);
25     ierr = PetscOptionsBool("-matmatmult_scalable","Use a scalable but slower C=A*B","",scalable,&scalable,NULL);CHKERRQ(ierr);
26     ierr = PetscOptionsBool("-matmatmult_scalable_fast","Use a scalable but slower C=A*B","",scalable_fast,&scalable_fast,NULL);CHKERRQ(ierr);
27     ierr = PetscOptionsBool("-matmatmult_heap","Use heap implementation of symbolic factorization C=A*B","",heap,&heap,NULL);CHKERRQ(ierr);
28     ierr = PetscOptionsBool("-matmatmult_btheap","Use btheap implementation of symbolic factorization C=A*B","",btheap,&btheap,NULL);CHKERRQ(ierr);
29     ierr = PetscOptionsBool("-matmatmult_llcondensed","Use LLCondensed to for symbolic C=A*B","",llcondensed,&llcondensed,NULL);CHKERRQ(ierr);
30     ierr = PetscOptionsEnd();CHKERRQ(ierr);
31     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
32     if (scalable_fast) {
33       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable_fast(A,B,fill,C);CHKERRQ(ierr);
34     } else if (scalable) {
35       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable(A,B,fill,C);CHKERRQ(ierr);
36     } else if (heap) {
37       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_Heap(A,B,fill,C);CHKERRQ(ierr);
38     } else if (btheap) {
39       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_BTHeap(A,B,fill,C);CHKERRQ(ierr);
40     } else if (llcondensed) {
41       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed(A,B,fill,C);CHKERRQ(ierr);
42     } else {
43       ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(A,B,fill,C);CHKERRQ(ierr);
44     }
45     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
46   }
47 
48   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
49   ierr = (*(*C)->ops->matmultnumeric)(A,B,*C);CHKERRQ(ierr);
50   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
51   PetscFunctionReturn(0);
52 }
53 
54 #undef __FUNCT__
55 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed"
56 static PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_LLCondensed(Mat A,Mat B,PetscReal fill,Mat *C)
57 {
58   PetscErrorCode     ierr;
59   Mat_SeqAIJ         *a =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
60   PetscInt           *ai=a->i,*bi=b->i,*ci,*cj;
61   PetscInt           am =A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
62   PetscReal          afill;
63   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,nlnk_max,*lnk,ndouble=0;
64   PetscBT            lnkbt;
65   PetscFreeSpaceList free_space=NULL,current_space=NULL;
66 
67   PetscFunctionBegin;
68   /* Get ci and cj */
69   /*---------------*/
70   /* Allocate ci array, arrays for fill computation and */
71   /* free space for accumulating nonzero column info */
72   ierr  = PetscMalloc(((am+1)+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
73   ci[0] = 0;
74 
75   /* create and initialize a linked list */
76   nlnk_max = a->rmax*b->rmax;
77   if (!nlnk_max || nlnk_max > bn) nlnk_max = bn;
78   ierr = PetscLLCondensedCreate(nlnk_max,bn,&lnk,&lnkbt);CHKERRQ(ierr);
79 
80   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
81   ierr = PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+bi[bm])),&free_space);CHKERRQ(ierr);
82 
83   current_space = free_space;
84 
85   /* Determine ci and cj */
86   for (i=0; i<am; i++) {
87     anzi = ai[i+1] - ai[i];
88     aj   = a->j + ai[i];
89     for (j=0; j<anzi; j++) {
90       brow = aj[j];
91       bnzj = bi[brow+1] - bi[brow];
92       bj   = b->j + bi[brow];
93       /* add non-zero cols of B into the sorted linked list lnk */
94       ierr = PetscLLCondensedAddSorted(bnzj,bj,lnk,lnkbt);CHKERRQ(ierr);
95     }
96     cnzi = lnk[0];
97 
98     /* If free space is not available, make more free space */
99     /* Double the amount of total space in the list */
100     if (current_space->local_remaining<cnzi) {
101       ierr = PetscFreeSpaceGet(cnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
102       ndouble++;
103     }
104 
105     /* Copy data into free space, then initialize lnk */
106     ierr = PetscLLCondensedClean(bn,cnzi,current_space->array,lnk,lnkbt);CHKERRQ(ierr);
107 
108     current_space->array           += cnzi;
109     current_space->local_used      += cnzi;
110     current_space->local_remaining -= cnzi;
111 
112     ci[i+1] = ci[i] + cnzi;
113   }
114 
115   /* Column indices are in the list of free space */
116   /* Allocate space for cj, initialize cj, and */
117   /* destroy list of free space and other temporary array(s) */
118   ierr = PetscMalloc((ci[am]+1)*sizeof(PetscInt),&cj);CHKERRQ(ierr);
119   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
120   ierr = PetscLLCondensedDestroy(lnk,lnkbt);CHKERRQ(ierr);
121 
122   /* put together the new symbolic matrix */
123   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,C);CHKERRQ(ierr);
124 
125   (*C)->rmap->bs = A->rmap->bs;
126   (*C)->cmap->bs = B->cmap->bs;
127 
128   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
129   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
130   c                         = (Mat_SeqAIJ*)((*C)->data);
131   c->free_a                 = PETSC_FALSE;
132   c->free_ij                = PETSC_TRUE;
133   c->nonew                  = 0;
134   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ; /* fast, needs non-scalable O(bn) array 'abdense' */
135 
136   /* set MatInfo */
137   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
138   if (afill < 1.0) afill = 1.0;
139   c->maxnz                     = ci[am];
140   c->nz                        = ci[am];
141   (*C)->info.mallocs           = ndouble;
142   (*C)->info.fill_ratio_given  = fill;
143   (*C)->info.fill_ratio_needed = afill;
144 
145 #if defined(PETSC_USE_INFO)
146   if (ci[am]) {
147     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
148     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
149   } else {
150     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
151   }
152 #endif
153   PetscFunctionReturn(0);
154 }
155 
156 #undef __FUNCT__
157 #define __FUNCT__ "MatMatMultNumeric_SeqAIJ_SeqAIJ"
158 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
159 {
160   PetscErrorCode ierr;
161   PetscLogDouble flops=0.0;
162   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)A->data;
163   Mat_SeqAIJ     *b   = (Mat_SeqAIJ*)B->data;
164   Mat_SeqAIJ     *c   = (Mat_SeqAIJ*)C->data;
165   PetscInt       *ai  =a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bjj,*ci=c->i,*cj=c->j;
166   PetscInt       am   =A->rmap->n,cm=C->rmap->n;
167   PetscInt       i,j,k,anzi,bnzi,cnzi,brow;
168   PetscScalar    *aa=a->a,*ba=b->a,*baj,*ca,valtmp;
169   PetscScalar    *ab_dense;
170 
171   PetscFunctionBegin;
172   /* printf("MatMatMultNumeric_SeqAIJ_SeqAIJ...ca %p\n",c->a); */
173   if (!c->a) { /* first call of MatMatMultNumeric_SeqAIJ_SeqAIJ, allocate ca and matmult_abdense */
174     ierr      = PetscMalloc((ci[cm]+1)*sizeof(MatScalar),&ca);CHKERRQ(ierr);
175     c->a      = ca;
176     c->free_a = PETSC_TRUE;
177 
178     ierr = PetscMalloc(B->cmap->N*sizeof(PetscScalar),&ab_dense);CHKERRQ(ierr);
179     ierr = PetscMemzero(ab_dense,B->cmap->N*sizeof(PetscScalar));CHKERRQ(ierr);
180 
181     c->matmult_abdense = ab_dense;
182   } else {
183     ca       = c->a;
184     ab_dense = c->matmult_abdense;
185   }
186 
187   /* clean old values in C */
188   ierr = PetscMemzero(ca,ci[cm]*sizeof(MatScalar));CHKERRQ(ierr);
189   /* Traverse A row-wise. */
190   /* Build the ith row in C by summing over nonzero columns in A, */
191   /* the rows of B corresponding to nonzeros of A. */
192   for (i=0; i<am; i++) {
193     anzi = ai[i+1] - ai[i];
194     for (j=0; j<anzi; j++) {
195       brow = aj[j];
196       bnzi = bi[brow+1] - bi[brow];
197       bjj  = bj + bi[brow];
198       baj  = ba + bi[brow];
199       /* perform dense axpy */
200       valtmp = aa[j];
201       for (k=0; k<bnzi; k++) {
202         ab_dense[bjj[k]] += valtmp*baj[k];
203       }
204       flops += 2*bnzi;
205     }
206     aj += anzi; aa += anzi;
207 
208     cnzi = ci[i+1] - ci[i];
209     for (k=0; k<cnzi; k++) {
210       ca[k]          += ab_dense[cj[k]];
211       ab_dense[cj[k]] = 0.0; /* zero ab_dense */
212     }
213     flops += cnzi;
214     cj    += cnzi; ca += cnzi;
215   }
216   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
217   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
218   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
219   PetscFunctionReturn(0);
220 }
221 
222 #undef __FUNCT__
223 #define __FUNCT__ "MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable"
224 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable(Mat A,Mat B,Mat C)
225 {
226   PetscErrorCode ierr;
227   PetscLogDouble flops=0.0;
228   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)A->data;
229   Mat_SeqAIJ     *b   = (Mat_SeqAIJ*)B->data;
230   Mat_SeqAIJ     *c   = (Mat_SeqAIJ*)C->data;
231   PetscInt       *ai  = a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bjj,*ci=c->i,*cj=c->j;
232   PetscInt       am   = A->rmap->N,cm=C->rmap->N;
233   PetscInt       i,j,k,anzi,bnzi,cnzi,brow;
234   PetscScalar    *aa=a->a,*ba=b->a,*baj,*ca=c->a,valtmp;
235   PetscInt       nextb;
236 
237   PetscFunctionBegin;
238   /* clean old values in C */
239   ierr = PetscMemzero(ca,ci[cm]*sizeof(MatScalar));CHKERRQ(ierr);
240   /* Traverse A row-wise. */
241   /* Build the ith row in C by summing over nonzero columns in A, */
242   /* the rows of B corresponding to nonzeros of A. */
243   for (i=0; i<am; i++) {
244     anzi = ai[i+1] - ai[i];
245     cnzi = ci[i+1] - ci[i];
246     for (j=0; j<anzi; j++) {
247       brow = aj[j];
248       bnzi = bi[brow+1] - bi[brow];
249       bjj  = bj + bi[brow];
250       baj  = ba + bi[brow];
251       /* perform sparse axpy */
252       valtmp = aa[j];
253       nextb  = 0;
254       for (k=0; nextb<bnzi; k++) {
255         if (cj[k] == bjj[nextb]) { /* ccol == bcol */
256           ca[k] += valtmp*baj[nextb++];
257         }
258       }
259       flops += 2*bnzi;
260     }
261     aj += anzi; aa += anzi;
262     cj += cnzi; ca += cnzi;
263   }
264 
265   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
266   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
267   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
268   PetscFunctionReturn(0);
269 }
270 
271 #undef __FUNCT__
272 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable_fast"
273 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable_fast(Mat A,Mat B,PetscReal fill,Mat *C)
274 {
275   PetscErrorCode     ierr;
276   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
277   PetscInt           *ai = a->i,*bi=b->i,*ci,*cj;
278   PetscInt           am  = A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
279   MatScalar          *ca;
280   PetscReal          afill;
281   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,nlnk_max,*lnk,ndouble=0;
282   PetscFreeSpaceList free_space=NULL,current_space=NULL;
283 
284   PetscFunctionBegin;
285   /* Get ci and cj - same as MatMatMultSymbolic_SeqAIJ_SeqAIJ except using PetscLLxxx_fast() */
286   /*-----------------------------------------------------------------------------------------*/
287   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
288   ierr  = PetscMalloc(((am+1)+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
289   ci[0] = 0;
290 
291   /* create and initialize a linked list */
292   nlnk_max = a->rmax*b->rmax;
293   if (!nlnk_max || nlnk_max > bn) nlnk_max = bn; /* in case rmax is not defined for A or B */
294   ierr = PetscLLCondensedCreate_fast(nlnk_max,&lnk);CHKERRQ(ierr);
295 
296   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
297   ierr          = PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+bi[bm])),&free_space);CHKERRQ(ierr);
298   current_space = free_space;
299 
300   /* Determine ci and cj */
301   for (i=0; i<am; i++) {
302     anzi = ai[i+1] - ai[i];
303     aj   = a->j + ai[i];
304     for (j=0; j<anzi; j++) {
305       brow = aj[j];
306       bnzj = bi[brow+1] - bi[brow];
307       bj   = b->j + bi[brow];
308       /* add non-zero cols of B into the sorted linked list lnk */
309       ierr = PetscLLCondensedAddSorted_fast(bnzj,bj,lnk);CHKERRQ(ierr);
310     }
311     cnzi = lnk[1];
312 
313     /* If free space is not available, make more free space */
314     /* Double the amount of total space in the list */
315     if (current_space->local_remaining<cnzi) {
316       ierr = PetscFreeSpaceGet(cnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
317       ndouble++;
318     }
319 
320     /* Copy data into free space, then initialize lnk */
321     ierr = PetscLLCondensedClean_fast(cnzi,current_space->array,lnk);CHKERRQ(ierr);
322 
323     current_space->array           += cnzi;
324     current_space->local_used      += cnzi;
325     current_space->local_remaining -= cnzi;
326 
327     ci[i+1] = ci[i] + cnzi;
328   }
329 
330   /* Column indices are in the list of free space */
331   /* Allocate space for cj, initialize cj, and */
332   /* destroy list of free space and other temporary array(s) */
333   ierr = PetscMalloc((ci[am]+1)*sizeof(PetscInt),&cj);CHKERRQ(ierr);
334   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
335   ierr = PetscLLCondensedDestroy_fast(lnk);CHKERRQ(ierr);
336 
337   /* Allocate space for ca */
338   ierr = PetscMalloc((ci[am]+1)*sizeof(MatScalar),&ca);CHKERRQ(ierr);
339   ierr = PetscMemzero(ca,(ci[am]+1)*sizeof(MatScalar));CHKERRQ(ierr);
340 
341   /* put together the new symbolic matrix */
342   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,ca,C);CHKERRQ(ierr);
343 
344   (*C)->rmap->bs = A->rmap->bs;
345   (*C)->cmap->bs = B->cmap->bs;
346 
347   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
348   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
349   c          = (Mat_SeqAIJ*)((*C)->data);
350   c->free_a  = PETSC_TRUE;
351   c->free_ij = PETSC_TRUE;
352   c->nonew   = 0;
353 
354   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable; /* slower, less memory */
355 
356   /* set MatInfo */
357   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
358   if (afill < 1.0) afill = 1.0;
359   c->maxnz                     = ci[am];
360   c->nz                        = ci[am];
361   (*C)->info.mallocs           = ndouble;
362   (*C)->info.fill_ratio_given  = fill;
363   (*C)->info.fill_ratio_needed = afill;
364 
365 #if defined(PETSC_USE_INFO)
366   if (ci[am]) {
367     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
368     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
369   } else {
370     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
371   }
372 #endif
373   PetscFunctionReturn(0);
374 }
375 
376 
377 #undef __FUNCT__
378 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable"
379 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Scalable(Mat A,Mat B,PetscReal fill,Mat *C)
380 {
381   PetscErrorCode     ierr;
382   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
383   PetscInt           *ai = a->i,*bi=b->i,*ci,*cj;
384   PetscInt           am  = A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
385   MatScalar          *ca;
386   PetscReal          afill;
387   PetscInt           i,j,anzi,brow,bnzj,cnzi,*bj,*aj,nlnk_max,*lnk,ndouble=0;
388   PetscFreeSpaceList free_space=NULL,current_space=NULL;
389 
390   PetscFunctionBegin;
391   /* Get ci and cj - same as MatMatMultSymbolic_SeqAIJ_SeqAIJ except using PetscLLxxx_Scalalbe() */
392   /*---------------------------------------------------------------------------------------------*/
393   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
394   ierr  = PetscMalloc(((am+1)+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
395   ci[0] = 0;
396 
397   /* create and initialize a linked list */
398   nlnk_max = a->rmax*b->rmax;
399   if (!nlnk_max || nlnk_max > bn) nlnk_max = bn; /* in case rmax is not defined for A or B */
400   ierr = PetscLLCondensedCreate_Scalable(nlnk_max,&lnk);CHKERRQ(ierr);
401 
402   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
403   ierr          = PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+bi[bm])),&free_space);CHKERRQ(ierr);
404   current_space = free_space;
405 
406   /* Determine ci and cj */
407   for (i=0; i<am; i++) {
408     anzi = ai[i+1] - ai[i];
409     aj   = a->j + ai[i];
410     for (j=0; j<anzi; j++) {
411       brow = aj[j];
412       bnzj = bi[brow+1] - bi[brow];
413       bj   = b->j + bi[brow];
414       /* add non-zero cols of B into the sorted linked list lnk */
415       ierr = PetscLLCondensedAddSorted_Scalable(bnzj,bj,lnk);CHKERRQ(ierr);
416     }
417     cnzi = lnk[0];
418 
419     /* If free space is not available, make more free space */
420     /* Double the amount of total space in the list */
421     if (current_space->local_remaining<cnzi) {
422       ierr = PetscFreeSpaceGet(cnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
423       ndouble++;
424     }
425 
426     /* Copy data into free space, then initialize lnk */
427     ierr = PetscLLCondensedClean_Scalable(cnzi,current_space->array,lnk);CHKERRQ(ierr);
428 
429     current_space->array           += cnzi;
430     current_space->local_used      += cnzi;
431     current_space->local_remaining -= cnzi;
432 
433     ci[i+1] = ci[i] + cnzi;
434   }
435 
436   /* Column indices are in the list of free space */
437   /* Allocate space for cj, initialize cj, and */
438   /* destroy list of free space and other temporary array(s) */
439   ierr = PetscMalloc((ci[am]+1)*sizeof(PetscInt),&cj);CHKERRQ(ierr);
440   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
441   ierr = PetscLLCondensedDestroy_Scalable(lnk);CHKERRQ(ierr);
442 
443   /* Allocate space for ca */
444   /*-----------------------*/
445   ierr = PetscMalloc((ci[am]+1)*sizeof(MatScalar),&ca);CHKERRQ(ierr);
446   ierr = PetscMemzero(ca,(ci[am]+1)*sizeof(MatScalar));CHKERRQ(ierr);
447 
448   /* put together the new symbolic matrix */
449   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,ca,C);CHKERRQ(ierr);
450 
451   (*C)->rmap->bs = A->rmap->bs;
452   (*C)->cmap->bs = B->cmap->bs;
453 
454   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
455   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
456   c          = (Mat_SeqAIJ*)((*C)->data);
457   c->free_a  = PETSC_TRUE;
458   c->free_ij = PETSC_TRUE;
459   c->nonew   = 0;
460 
461   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ_Scalable; /* slower, less memory */
462 
463   /* set MatInfo */
464   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
465   if (afill < 1.0) afill = 1.0;
466   c->maxnz                     = ci[am];
467   c->nz                        = ci[am];
468   (*C)->info.mallocs           = ndouble;
469   (*C)->info.fill_ratio_given  = fill;
470   (*C)->info.fill_ratio_needed = afill;
471 
472 #if defined(PETSC_USE_INFO)
473   if (ci[am]) {
474     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
475     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
476   } else {
477     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
478   }
479 #endif
480   PetscFunctionReturn(0);
481 }
482 
483 #undef __FUNCT__
484 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ_Heap"
485 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_Heap(Mat A,Mat B,PetscReal fill,Mat *C)
486 {
487   PetscErrorCode     ierr;
488   Mat_SeqAIJ         *a = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
489   const PetscInt     *ai=a->i,*bi=b->i,*aj=a->j,*bj=b->j;
490   PetscInt           *ci,*cj,*bb;
491   PetscInt           am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
492   PetscReal          afill;
493   PetscInt           i,j,col,ndouble = 0;
494   PetscFreeSpaceList free_space=NULL,current_space=NULL;
495   PetscHeap          h;
496 
497   PetscFunctionBegin;
498   /* Get ci and cj - by merging sorted rows using a heap */
499   /*---------------------------------------------------------------------------------------------*/
500   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
501   ierr  = PetscMalloc(((am+1)+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
502   ci[0] = 0;
503 
504   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
505   ierr          = PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+bi[bm])),&free_space);CHKERRQ(ierr);
506   current_space = free_space;
507 
508   ierr = PetscHeapCreate(a->rmax,&h);CHKERRQ(ierr);
509   ierr = PetscMalloc(a->rmax*sizeof(PetscInt),&bb);CHKERRQ(ierr);
510 
511   /* Determine ci and cj */
512   for (i=0; i<am; i++) {
513     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 */
514     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
515     ci[i+1] = ci[i];
516     /* Populate the min heap */
517     for (j=0; j<anzi; j++) {
518       bb[j] = bi[acol[j]];         /* bb points at the start of the row */
519       if (bb[j] < bi[acol[j]+1]) { /* Add if row is nonempty */
520         ierr = PetscHeapAdd(h,j,bj[bb[j]++]);CHKERRQ(ierr);
521       }
522     }
523     /* Pick off the min element, adding it to free space */
524     ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
525     while (j >= 0) {
526       if (current_space->local_remaining < 1) { /* double the size, but don't exceed 16 MiB */
527         ierr = PetscFreeSpaceGet(PetscMin(2*current_space->total_array_size,16 << 20),&current_space);CHKERRQ(ierr);
528         ndouble++;
529       }
530       *(current_space->array++) = col;
531       current_space->local_used++;
532       current_space->local_remaining--;
533       ci[i+1]++;
534 
535       /* stash if anything else remains in this row of B */
536       if (bb[j] < bi[acol[j]+1]) {ierr = PetscHeapStash(h,j,bj[bb[j]++]);CHKERRQ(ierr);}
537       while (1) {               /* pop and stash any other rows of B that also had an entry in this column */
538         PetscInt j2,col2;
539         ierr = PetscHeapPeek(h,&j2,&col2);CHKERRQ(ierr);
540         if (col2 != col) break;
541         ierr = PetscHeapPop(h,&j2,&col2);CHKERRQ(ierr);
542         if (bb[j2] < bi[acol[j2]+1]) {ierr = PetscHeapStash(h,j2,bj[bb[j2]++]);CHKERRQ(ierr);}
543       }
544       /* Put any stashed elements back into the min heap */
545       ierr = PetscHeapUnstash(h);CHKERRQ(ierr);
546       ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
547     }
548   }
549   ierr = PetscFree(bb);CHKERRQ(ierr);
550   ierr = PetscHeapDestroy(&h);CHKERRQ(ierr);
551 
552   /* Column indices are in the list of free space */
553   /* Allocate space for cj, initialize cj, and */
554   /* destroy list of free space and other temporary array(s) */
555   ierr = PetscMalloc(ci[am]*sizeof(PetscInt),&cj);CHKERRQ(ierr);
556   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
557 
558   /* put together the new symbolic matrix */
559   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,C);CHKERRQ(ierr);
560 
561   (*C)->rmap->bs = A->rmap->bs;
562   (*C)->cmap->bs = B->cmap->bs;
563 
564   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
565   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
566   c          = (Mat_SeqAIJ*)((*C)->data);
567   c->free_a  = PETSC_TRUE;
568   c->free_ij = PETSC_TRUE;
569   c->nonew   = 0;
570 
571   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ;
572 
573   /* set MatInfo */
574   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
575   if (afill < 1.0) afill = 1.0;
576   c->maxnz                     = ci[am];
577   c->nz                        = ci[am];
578   (*C)->info.mallocs           = ndouble;
579   (*C)->info.fill_ratio_given  = fill;
580   (*C)->info.fill_ratio_needed = afill;
581 
582 #if defined(PETSC_USE_INFO)
583   if (ci[am]) {
584     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
585     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
586   } else {
587     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
588   }
589 #endif
590   PetscFunctionReturn(0);
591 }
592 
593 #undef __FUNCT__
594 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ_BTHeap"
595 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ_BTHeap(Mat A,Mat B,PetscReal fill,Mat *C)
596 {
597   PetscErrorCode     ierr;
598   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
599   const PetscInt     *ai = a->i,*bi=b->i,*aj=a->j,*bj=b->j;
600   PetscInt           *ci,*cj,*bb;
601   PetscInt           am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
602   PetscReal          afill;
603   PetscInt           i,j,col,ndouble = 0;
604   PetscFreeSpaceList free_space=NULL,current_space=NULL;
605   PetscHeap          h;
606   PetscBT            bt;
607 
608   PetscFunctionBegin;
609   /* Get ci and cj - using a heap for the sorted rows, but use BT so that each index is only added once */
610   /*---------------------------------------------------------------------------------------------*/
611   /* Allocate arrays for fill computation and free space for accumulating nonzero column */
612   ierr  = PetscMalloc(((am+1)+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
613   ci[0] = 0;
614 
615   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
616   ierr = PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+bi[bm])),&free_space);CHKERRQ(ierr);
617 
618   current_space = free_space;
619 
620   ierr = PetscHeapCreate(a->rmax,&h);CHKERRQ(ierr);
621   ierr = PetscMalloc(a->rmax*sizeof(PetscInt),&bb);CHKERRQ(ierr);
622   ierr = PetscBTCreate(bn,&bt);CHKERRQ(ierr);
623 
624   /* Determine ci and cj */
625   for (i=0; i<am; i++) {
626     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 */
627     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
628     const PetscInt *fptr = current_space->array; /* Save beginning of the row so we can clear the BT later */
629     ci[i+1] = ci[i];
630     /* Populate the min heap */
631     for (j=0; j<anzi; j++) {
632       PetscInt brow = acol[j];
633       for (bb[j] = bi[brow]; bb[j] < bi[brow+1]; bb[j]++) {
634         PetscInt bcol = bj[bb[j]];
635         if (!PetscBTLookupSet(bt,bcol)) { /* new entry */
636           ierr = PetscHeapAdd(h,j,bcol);CHKERRQ(ierr);
637           bb[j]++;
638           break;
639         }
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         fptr = NULL;                      /* need PetscBTMemzero */
647         ierr = PetscFreeSpaceGet(PetscMin(2*current_space->total_array_size,16 << 20),&current_space);CHKERRQ(ierr);
648         ndouble++;
649       }
650       *(current_space->array++) = col;
651       current_space->local_used++;
652       current_space->local_remaining--;
653       ci[i+1]++;
654 
655       /* stash if anything else remains in this row of B */
656       for (; bb[j] < bi[acol[j]+1]; bb[j]++) {
657         PetscInt bcol = bj[bb[j]];
658         if (!PetscBTLookupSet(bt,bcol)) { /* new entry */
659           ierr = PetscHeapAdd(h,j,bcol);CHKERRQ(ierr);
660           bb[j]++;
661           break;
662         }
663       }
664       ierr = PetscHeapPop(h,&j,&col);CHKERRQ(ierr);
665     }
666     if (fptr) {                 /* Clear the bits for this row */
667       for (; fptr<current_space->array; fptr++) {ierr = PetscBTClear(bt,*fptr);CHKERRQ(ierr);}
668     } else {                    /* We reallocated so we don't remember (easily) how to clear only the bits we changed */
669       ierr = PetscBTMemzero(bn,bt);CHKERRQ(ierr);
670     }
671   }
672   ierr = PetscFree(bb);CHKERRQ(ierr);
673   ierr = PetscHeapDestroy(&h);CHKERRQ(ierr);
674   ierr = PetscBTDestroy(&bt);CHKERRQ(ierr);
675 
676   /* Column indices are in the list of free space */
677   /* Allocate space for cj, initialize cj, and */
678   /* destroy list of free space and other temporary array(s) */
679   ierr = PetscMalloc(ci[am]*sizeof(PetscInt),&cj);CHKERRQ(ierr);
680   ierr = PetscFreeSpaceContiguous(&free_space,cj);CHKERRQ(ierr);
681 
682   /* put together the new symbolic matrix */
683   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,C);CHKERRQ(ierr);
684 
685   (*C)->rmap->bs = A->rmap->bs;
686   (*C)->cmap->bs = B->cmap->bs;
687 
688   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
689   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
690   c          = (Mat_SeqAIJ*)((*C)->data);
691   c->free_a  = PETSC_TRUE;
692   c->free_ij = PETSC_TRUE;
693   c->nonew   = 0;
694 
695   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ;
696 
697   /* set MatInfo */
698   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
699   if (afill < 1.0) afill = 1.0;
700   c->maxnz                     = ci[am];
701   c->nz                        = ci[am];
702   (*C)->info.mallocs           = ndouble;
703   (*C)->info.fill_ratio_given  = fill;
704   (*C)->info.fill_ratio_needed = afill;
705 
706 #if defined(PETSC_USE_INFO)
707   if (ci[am]) {
708     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
709     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
710   } else {
711     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
712   }
713 #endif
714   PetscFunctionReturn(0);
715 }
716 
717 #undef __FUNCT__
718 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqAIJ"
719 /* concatenate unique entries and then sort */
720 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
721 {
722   PetscErrorCode     ierr;
723   Mat_SeqAIJ         *a  = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c;
724   const PetscInt     *ai = a->i,*bi=b->i,*aj=a->j,*bj=b->j;
725   PetscInt           *ci,*cj;
726   PetscInt           am=A->rmap->N,bn=B->cmap->N,bm=B->rmap->N;
727   PetscReal          afill;
728   PetscInt           i,j,ndouble = 0;
729   PetscSegBuffer     seg,segrow;
730   char               *seen;
731 
732   PetscFunctionBegin;
733   ierr  = PetscMalloc((am+1)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
734   ci[0] = 0;
735 
736   /* Initial FreeSpace size is fill*(nnz(A)+nnz(B)) */
737   ierr = PetscSegBufferCreate(sizeof(PetscInt),(PetscInt)(fill*(ai[am]+bi[bm])),&seg);CHKERRQ(ierr);
738   ierr = PetscSegBufferCreate(sizeof(PetscInt),100,&segrow);CHKERRQ(ierr);
739   ierr = PetscMalloc(bn*sizeof(char),&seen);CHKERRQ(ierr);
740   ierr = PetscMemzero(seen,bn*sizeof(char));CHKERRQ(ierr);
741 
742   /* Determine ci and cj */
743   for (i=0; i<am; i++) {
744     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 */
745     const PetscInt *acol = aj + ai[i]; /* column indices of nonzero entries in this row */
746     PetscInt packlen = 0,*PETSC_RESTRICT crow;
747     /* Pack segrow */
748     for (j=0; j<anzi; j++) {
749       PetscInt brow = acol[j],bjstart = bi[brow],bjend = bi[brow+1],k;
750       for (k=bjstart; k<bjend; k++) {
751         PetscInt bcol = bj[k];
752         if (!seen[bcol]) { /* new entry */
753           PetscInt *PETSC_RESTRICT slot;
754           ierr = PetscSegBufferGetInts(segrow,1,&slot);CHKERRQ(ierr);
755           *slot = bcol;
756           seen[bcol] = 1;
757           packlen++;
758         }
759       }
760     }
761     ierr = PetscSegBufferGetInts(seg,packlen,&crow);CHKERRQ(ierr);
762     ierr = PetscSegBufferExtractTo(segrow,crow);CHKERRQ(ierr);
763     ierr = PetscSortInt(packlen,crow);CHKERRQ(ierr);
764     ci[i+1] = ci[i] + packlen;
765     for (j=0; j<packlen; j++) seen[crow[j]] = 0;
766   }
767   ierr = PetscSegBufferDestroy(&segrow);CHKERRQ(ierr);
768   ierr = PetscFree(seen);CHKERRQ(ierr);
769 
770   /* Column indices are in the segmented buffer */
771   ierr = PetscSegBufferExtractAlloc(seg,&cj);CHKERRQ(ierr);
772   ierr = PetscSegBufferDestroy(&seg);CHKERRQ(ierr);
773 
774   /* put together the new symbolic matrix */
775   ierr = MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A),am,bn,ci,cj,NULL,C);CHKERRQ(ierr);
776 
777   (*C)->rmap->bs = A->rmap->bs;
778   (*C)->cmap->bs = B->cmap->bs;
779 
780   /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
781   /* These are PETSc arrays, so change flags so arrays can be deleted by PETSc */
782   c          = (Mat_SeqAIJ*)((*C)->data);
783   c->free_a  = PETSC_TRUE;
784   c->free_ij = PETSC_TRUE;
785   c->nonew   = 0;
786 
787   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqAIJ;
788 
789   /* set MatInfo */
790   afill = (PetscReal)ci[am]/(ai[am]+bi[bm]) + 1.e-5;
791   if (afill < 1.0) afill = 1.0;
792   c->maxnz                     = ci[am];
793   c->nz                        = ci[am];
794   (*C)->info.mallocs           = ndouble;
795   (*C)->info.fill_ratio_given  = fill;
796   (*C)->info.fill_ratio_needed = afill;
797 
798 #if defined(PETSC_USE_INFO)
799   if (ci[am]) {
800     ierr = PetscInfo3((*C),"Reallocs %D; Fill ratio: given %G needed %G.\n",ndouble,fill,afill);CHKERRQ(ierr);
801     ierr = PetscInfo1((*C),"Use MatMatMult(A,B,MatReuse,%G,&C) for best performance.;\n",afill);CHKERRQ(ierr);
802   } else {
803     ierr = PetscInfo((*C),"Empty matrix product\n");CHKERRQ(ierr);
804   }
805 #endif
806   PetscFunctionReturn(0);
807 }
808 
809 /* This routine is not used. Should be removed! */
810 #undef __FUNCT__
811 #define __FUNCT__ "MatMatTransposeMult_SeqAIJ_SeqAIJ"
812 PetscErrorCode MatMatTransposeMult_SeqAIJ_SeqAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
813 {
814   PetscErrorCode ierr;
815 
816   PetscFunctionBegin;
817   if (scall == MAT_INITIAL_MATRIX) {
818     ierr = PetscLogEventBegin(MAT_MatTransposeMultSymbolic,A,B,0,0);CHKERRQ(ierr);
819     ierr = MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ(A,B,fill,C);CHKERRQ(ierr);
820     ierr = PetscLogEventEnd(MAT_MatTransposeMultSymbolic,A,B,0,0);CHKERRQ(ierr);
821   }
822   ierr = PetscLogEventBegin(MAT_MatTransposeMultNumeric,A,B,0,0);CHKERRQ(ierr);
823   ierr = MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ(A,B,*C);CHKERRQ(ierr);
824   ierr = PetscLogEventEnd(MAT_MatTransposeMultNumeric,A,B,0,0);CHKERRQ(ierr);
825   PetscFunctionReturn(0);
826 }
827 
828 #undef __FUNCT__
829 #define __FUNCT__ "PetscContainerDestroy_Mat_MatMatTransMult"
830 PetscErrorCode PetscContainerDestroy_Mat_MatMatTransMult(void *ptr)
831 {
832   PetscErrorCode      ierr;
833   Mat_MatMatTransMult *multtrans=(Mat_MatMatTransMult*)ptr;
834 
835   PetscFunctionBegin;
836   ierr = MatTransposeColoringDestroy(&multtrans->matcoloring);CHKERRQ(ierr);
837   ierr = MatDestroy(&multtrans->Bt_den);CHKERRQ(ierr);
838   ierr = MatDestroy(&multtrans->ABt_den);CHKERRQ(ierr);
839   ierr = PetscFree(multtrans);CHKERRQ(ierr);
840   PetscFunctionReturn(0);
841 }
842 
843 #undef __FUNCT__
844 #define __FUNCT__ "MatDestroy_SeqAIJ_MatMatMultTrans"
845 PetscErrorCode MatDestroy_SeqAIJ_MatMatMultTrans(Mat A)
846 {
847   PetscErrorCode      ierr;
848   PetscContainer      container;
849   Mat_MatMatTransMult *multtrans=NULL;
850 
851   PetscFunctionBegin;
852   ierr = PetscObjectQuery((PetscObject)A,"Mat_MatMatTransMult",(PetscObject*)&container);CHKERRQ(ierr);
853   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
854   ierr = PetscContainerGetPointer(container,(void**)&multtrans);CHKERRQ(ierr);
855 
856   A->ops->destroy = multtrans->destroy;
857   if (A->ops->destroy) {
858     ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
859   }
860   ierr = PetscObjectCompose((PetscObject)A,"Mat_MatMatTransMult",0);CHKERRQ(ierr);
861   PetscFunctionReturn(0);
862 }
863 
864 #undef __FUNCT__
865 #define __FUNCT__ "MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ"
866 PetscErrorCode MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
867 {
868   PetscErrorCode      ierr;
869   Mat                 Bt;
870   PetscInt            *bti,*btj;
871   Mat_MatMatTransMult *multtrans;
872   PetscContainer      container;
873 
874   PetscFunctionBegin;
875   /* create symbolic Bt */
876   ierr = MatGetSymbolicTranspose_SeqAIJ(B,&bti,&btj);CHKERRQ(ierr);
877   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,B->cmap->n,B->rmap->n,bti,btj,NULL,&Bt);CHKERRQ(ierr);
878 
879   Bt->rmap->bs = A->cmap->bs;
880   Bt->cmap->bs = B->cmap->bs;
881 
882   /* get symbolic C=A*Bt */
883   ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(A,Bt,fill,C);CHKERRQ(ierr);
884 
885   /* create a supporting struct for reuse intermidiate dense matrices with matcoloring */
886   ierr = PetscNew(Mat_MatMatTransMult,&multtrans);CHKERRQ(ierr);
887 
888   /* attach the supporting struct to C */
889   ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
890   ierr = PetscContainerSetPointer(container,multtrans);CHKERRQ(ierr);
891   ierr = PetscContainerSetUserDestroy(container,PetscContainerDestroy_Mat_MatMatTransMult);CHKERRQ(ierr);
892   ierr = PetscObjectCompose((PetscObject)(*C),"Mat_MatMatTransMult",(PetscObject)container);CHKERRQ(ierr);
893   ierr = PetscContainerDestroy(&container);CHKERRQ(ierr);
894 
895   multtrans->usecoloring = PETSC_FALSE;
896   multtrans->destroy     = (*C)->ops->destroy;
897   (*C)->ops->destroy     = MatDestroy_SeqAIJ_MatMatMultTrans;
898 
899   ierr = PetscOptionsGetBool(NULL,"-matmattransmult_color",&multtrans->usecoloring,NULL);CHKERRQ(ierr);
900   if (multtrans->usecoloring) {
901     /* Create MatTransposeColoring from symbolic C=A*B^T */
902     MatTransposeColoring matcoloring;
903     ISColoring           iscoloring;
904     Mat                  Bt_dense,C_dense;
905 
906     ierr = MatGetColoring(*C,MATCOLORINGLF,&iscoloring);CHKERRQ(ierr);
907     ierr = MatTransposeColoringCreate(*C,iscoloring,&matcoloring);CHKERRQ(ierr);
908 
909     multtrans->matcoloring = matcoloring;
910 
911     ierr = ISColoringDestroy(&iscoloring);CHKERRQ(ierr);
912 
913     /* Create Bt_dense and C_dense = A*Bt_dense */
914     ierr = MatCreate(PETSC_COMM_SELF,&Bt_dense);CHKERRQ(ierr);
915     ierr = MatSetSizes(Bt_dense,A->cmap->n,matcoloring->ncolors,A->cmap->n,matcoloring->ncolors);CHKERRQ(ierr);
916     ierr = MatSetType(Bt_dense,MATSEQDENSE);CHKERRQ(ierr);
917     ierr = MatSeqDenseSetPreallocation(Bt_dense,NULL);CHKERRQ(ierr);
918 
919     Bt_dense->assembled = PETSC_TRUE;
920     multtrans->Bt_den   = Bt_dense;
921 
922     ierr = MatCreate(PETSC_COMM_SELF,&C_dense);CHKERRQ(ierr);
923     ierr = MatSetSizes(C_dense,A->rmap->n,matcoloring->ncolors,A->rmap->n,matcoloring->ncolors);CHKERRQ(ierr);
924     ierr = MatSetType(C_dense,MATSEQDENSE);CHKERRQ(ierr);
925     ierr = MatSeqDenseSetPreallocation(C_dense,NULL);CHKERRQ(ierr);
926 
927     Bt_dense->assembled = PETSC_TRUE;
928     multtrans->ABt_den  = C_dense;
929 
930 #if defined(PETSC_USE_INFO)
931     {
932       Mat_SeqAIJ *c = (Mat_SeqAIJ*)(*C)->data;
933       ierr = PetscInfo5(*C,"Bt_dense: %D,%D; Cnz %D / (cm*ncolors %D) = %g\n",A->cmap->n,matcoloring->ncolors,c->nz,A->rmap->n*matcoloring->ncolors,(PetscReal)(c->nz)/(A->rmap->n*matcoloring->ncolors));CHKERRQ(ierr);
934     }
935 #endif
936   }
937   /* clean up */
938   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
939   ierr = MatRestoreSymbolicTranspose_SeqAIJ(B,&bti,&btj);CHKERRQ(ierr);
940   PetscFunctionReturn(0);
941 }
942 
943 /* #define USE_ARRAY - for sparse dot product. Slower than !USE_ARRAY */
944 #undef __FUNCT__
945 #define __FUNCT__ "MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ"
946 PetscErrorCode MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
947 {
948   PetscErrorCode      ierr;
949   Mat_SeqAIJ          *a   =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c=(Mat_SeqAIJ*)C->data;
950   PetscInt            *ai  =a->i,*aj=a->j,*bi=b->i,*bj=b->j,anzi,bnzj,nexta,nextb,*acol,*bcol,brow;
951   PetscInt            cm   =C->rmap->n,*ci=c->i,*cj=c->j,i,j,cnzi,*ccol;
952   PetscLogDouble      flops=0.0;
953   MatScalar           *aa  =a->a,*aval,*ba=b->a,*bval,*ca,*cval;
954   Mat_MatMatTransMult *multtrans;
955   PetscContainer      container;
956 #if defined(USE_ARRAY)
957   MatScalar *spdot;
958 #endif
959 
960   PetscFunctionBegin;
961   /* clear old values in C */
962   if (!c->a) {
963     ierr      = PetscMalloc((ci[cm]+1)*sizeof(MatScalar),&ca);CHKERRQ(ierr);
964     c->a      = ca;
965     c->free_a = PETSC_TRUE;
966   } else {
967     ca =  c->a;
968   }
969   ierr = PetscMemzero(ca,ci[cm]*sizeof(MatScalar));CHKERRQ(ierr);
970 
971   ierr = PetscObjectQuery((PetscObject)C,"Mat_MatMatTransMult",(PetscObject*)&container);CHKERRQ(ierr);
972   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
973   ierr = PetscContainerGetPointer(container,(void**)&multtrans);CHKERRQ(ierr);
974   if (multtrans->usecoloring) {
975     MatTransposeColoring matcoloring = multtrans->matcoloring;
976     Mat                  Bt_dense;
977     PetscInt             m,n;
978     Mat                  C_dense = multtrans->ABt_den;
979 
980     Bt_dense = multtrans->Bt_den;
981     ierr     = MatGetLocalSize(Bt_dense,&m,&n);CHKERRQ(ierr);
982 
983     /* Get Bt_dense by Apply MatTransposeColoring to B */
984     ierr = MatTransColoringApplySpToDen(matcoloring,B,Bt_dense);CHKERRQ(ierr);
985 
986     /* C_dense = A*Bt_dense */
987     ierr = MatMatMultNumeric_SeqAIJ_SeqDense(A,Bt_dense,C_dense);CHKERRQ(ierr);
988 
989     /* Recover C from C_dense */
990     ierr = MatTransColoringApplyDenToSp(matcoloring,C_dense,C);CHKERRQ(ierr);
991     PetscFunctionReturn(0);
992   }
993 
994 #if defined(USE_ARRAY)
995   /* allocate an array for implementing sparse inner-product */
996   ierr = PetscMalloc((A->cmap->n+1)*sizeof(MatScalar),&spdot);CHKERRQ(ierr);
997   ierr = PetscMemzero(spdot,(A->cmap->n+1)*sizeof(MatScalar));CHKERRQ(ierr);
998 #endif
999 
1000   for (i=0; i<cm; i++) {
1001     anzi = ai[i+1] - ai[i];
1002     acol = aj + ai[i];
1003     aval = aa + ai[i];
1004     cnzi = ci[i+1] - ci[i];
1005     ccol = cj + ci[i];
1006     cval = ca + ci[i];
1007     for (j=0; j<cnzi; j++) {
1008       brow = ccol[j];
1009       bnzj = bi[brow+1] - bi[brow];
1010       bcol = bj + bi[brow];
1011       bval = ba + bi[brow];
1012 
1013       /* perform sparse inner-product c(i,j)=A[i,:]*B[j,:]^T */
1014 #if defined(USE_ARRAY)
1015       /* put ba to spdot array */
1016       for (nextb=0; nextb<bnzj; nextb++) spdot[bcol[nextb]] = bval[nextb];
1017       /* c(i,j)=A[i,:]*B[j,:]^T */
1018       for (nexta=0; nexta<anzi; nexta++) {
1019         cval[j] += spdot[acol[nexta]]*aval[nexta];
1020       }
1021       /* zero spdot array */
1022       for (nextb=0; nextb<bnzj; nextb++) spdot[bcol[nextb]] = 0.0;
1023 #else
1024       nexta = 0; nextb = 0;
1025       while (nexta<anzi && nextb<bnzj) {
1026         while (nexta < anzi && acol[nexta] < bcol[nextb]) nexta++;
1027         if (nexta == anzi) break;
1028         while (nextb < bnzj && acol[nexta] > bcol[nextb]) nextb++;
1029         if (nextb == bnzj) break;
1030         if (acol[nexta] == bcol[nextb]) {
1031           cval[j] += aval[nexta]*bval[nextb];
1032           nexta++; nextb++;
1033           flops += 2;
1034         }
1035       }
1036 #endif
1037     }
1038   }
1039   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1040   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1041   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
1042 #if defined(USE_ARRAY)
1043   ierr = PetscFree(spdot);
1044 #endif
1045   PetscFunctionReturn(0);
1046 }
1047 
1048 #undef __FUNCT__
1049 #define __FUNCT__ "MatTransposeMatMult_SeqAIJ_SeqAIJ"
1050 PetscErrorCode MatTransposeMatMult_SeqAIJ_SeqAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
1051 {
1052   PetscErrorCode ierr;
1053 
1054   PetscFunctionBegin;
1055   if (scall == MAT_INITIAL_MATRIX) {
1056     ierr = MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ(A,B,fill,C);CHKERRQ(ierr);
1057   }
1058   ierr = MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ(A,B,*C);CHKERRQ(ierr);
1059   PetscFunctionReturn(0);
1060 }
1061 
1062 #undef __FUNCT__
1063 #define __FUNCT__ "MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ"
1064 PetscErrorCode MatTransposeMatMultSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
1065 {
1066   PetscErrorCode ierr;
1067   Mat            At;
1068   PetscInt       *ati,*atj;
1069 
1070   PetscFunctionBegin;
1071   /* create symbolic At */
1072   ierr = MatGetSymbolicTranspose_SeqAIJ(A,&ati,&atj);CHKERRQ(ierr);
1073   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,A->cmap->n,A->rmap->n,ati,atj,NULL,&At);CHKERRQ(ierr);
1074 
1075   At->rmap->bs = A->cmap->bs;
1076   At->cmap->bs = B->cmap->bs;
1077 
1078   /* get symbolic C=At*B */
1079   ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(At,B,fill,C);CHKERRQ(ierr);
1080 
1081   /* clean up */
1082   ierr = MatDestroy(&At);CHKERRQ(ierr);
1083   ierr = MatRestoreSymbolicTranspose_SeqAIJ(A,&ati,&atj);CHKERRQ(ierr);
1084   PetscFunctionReturn(0);
1085 }
1086 
1087 #undef __FUNCT__
1088 #define __FUNCT__ "MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ"
1089 PetscErrorCode MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C)
1090 {
1091   PetscErrorCode ierr;
1092   Mat_SeqAIJ     *a   =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data,*c=(Mat_SeqAIJ*)C->data;
1093   PetscInt       am   =A->rmap->n,anzi,*ai=a->i,*aj=a->j,*bi=b->i,*bj,bnzi,nextb;
1094   PetscInt       cm   =C->rmap->n,*ci=c->i,*cj=c->j,crow,*cjj,i,j,k;
1095   PetscLogDouble flops=0.0;
1096   MatScalar      *aa  =a->a,*ba,*ca,*caj;
1097 
1098   PetscFunctionBegin;
1099   if (!c->a) {
1100     ierr = PetscMalloc((ci[cm]+1)*sizeof(MatScalar),&ca);CHKERRQ(ierr);
1101 
1102     c->a      = ca;
1103     c->free_a = PETSC_TRUE;
1104   } else {
1105     ca = c->a;
1106   }
1107   /* clear old values in C */
1108   ierr = PetscMemzero(ca,ci[cm]*sizeof(MatScalar));CHKERRQ(ierr);
1109 
1110   /* compute A^T*B using outer product (A^T)[:,i]*B[i,:] */
1111   for (i=0; i<am; i++) {
1112     bj   = b->j + bi[i];
1113     ba   = b->a + bi[i];
1114     bnzi = bi[i+1] - bi[i];
1115     anzi = ai[i+1] - ai[i];
1116     for (j=0; j<anzi; j++) {
1117       nextb = 0;
1118       crow  = *aj++;
1119       cjj   = cj + ci[crow];
1120       caj   = ca + ci[crow];
1121       /* perform sparse axpy operation.  Note cjj includes bj. */
1122       for (k=0; nextb<bnzi; k++) {
1123         if (cjj[k] == *(bj+nextb)) { /* ccol == bcol */
1124           caj[k] += (*aa)*(*(ba+nextb));
1125           nextb++;
1126         }
1127       }
1128       flops += 2*bnzi;
1129       aa++;
1130     }
1131   }
1132 
1133   /* Assemble the final matrix and clean up */
1134   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1135   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1136   ierr = PetscLogFlops(flops);CHKERRQ(ierr);
1137   PetscFunctionReturn(0);
1138 }
1139 
1140 #undef __FUNCT__
1141 #define __FUNCT__ "MatMatMult_SeqAIJ_SeqDense"
1142 PetscErrorCode MatMatMult_SeqAIJ_SeqDense(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
1143 {
1144   PetscErrorCode ierr;
1145 
1146   PetscFunctionBegin;
1147   if (scall == MAT_INITIAL_MATRIX) {
1148     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
1149     ierr = MatMatMultSymbolic_SeqAIJ_SeqDense(A,B,fill,C);CHKERRQ(ierr);
1150     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
1151   }
1152   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
1153   ierr = MatMatMultNumeric_SeqAIJ_SeqDense(A,B,*C);CHKERRQ(ierr);
1154   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
1155   PetscFunctionReturn(0);
1156 }
1157 
1158 #undef __FUNCT__
1159 #define __FUNCT__ "MatMatMultSymbolic_SeqAIJ_SeqDense"
1160 PetscErrorCode MatMatMultSymbolic_SeqAIJ_SeqDense(Mat A,Mat B,PetscReal fill,Mat *C)
1161 {
1162   PetscErrorCode ierr;
1163 
1164   PetscFunctionBegin;
1165   ierr = MatMatMultSymbolic_SeqDense_SeqDense(A,B,0.0,C);CHKERRQ(ierr);
1166 
1167   (*C)->ops->matmultnumeric = MatMatMultNumeric_SeqAIJ_SeqDense;
1168   PetscFunctionReturn(0);
1169 }
1170 
1171 #undef __FUNCT__
1172 #define __FUNCT__ "MatMatMultNumeric_SeqAIJ_SeqDense"
1173 PetscErrorCode MatMatMultNumeric_SeqAIJ_SeqDense(Mat A,Mat B,Mat C)
1174 {
1175   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data;
1176   PetscErrorCode ierr;
1177   PetscScalar    *b,*c,r1,r2,r3,r4,*b1,*b2,*b3,*b4;
1178   MatScalar      *aa;
1179   PetscInt       cm  = C->rmap->n, cn=B->cmap->n, bm=B->rmap->n, col, i,j,n,*aj, am = A->rmap->n;
1180   PetscInt       am2 = 2*am, am3 = 3*am,  bm4 = 4*bm,colam;
1181 
1182   PetscFunctionBegin;
1183   if (!cm || !cn) PetscFunctionReturn(0);
1184   if (bm != 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,bm);
1185   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);
1186   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);
1187   ierr = MatDenseGetArray(B,&b);CHKERRQ(ierr);
1188   ierr = MatDenseGetArray(C,&c);CHKERRQ(ierr);
1189   b1   = b; b2 = b1 + bm; b3 = b2 + bm; b4 = b3 + bm;
1190   for (col=0; col<cn-4; col += 4) {  /* over columns of C */
1191     colam = col*am;
1192     for (i=0; i<am; i++) {        /* over rows of C in those columns */
1193       r1 = r2 = r3 = r4 = 0.0;
1194       n  = a->i[i+1] - a->i[i];
1195       aj = a->j + a->i[i];
1196       aa = a->a + a->i[i];
1197       for (j=0; j<n; j++) {
1198         r1 += (*aa)*b1[*aj];
1199         r2 += (*aa)*b2[*aj];
1200         r3 += (*aa)*b3[*aj];
1201         r4 += (*aa++)*b4[*aj++];
1202       }
1203       c[colam + i]       = r1;
1204       c[colam + am + i]  = r2;
1205       c[colam + am2 + i] = r3;
1206       c[colam + am3 + i] = r4;
1207     }
1208     b1 += bm4;
1209     b2 += bm4;
1210     b3 += bm4;
1211     b4 += bm4;
1212   }
1213   for (; col<cn; col++) {     /* over extra columns of C */
1214     for (i=0; i<am; i++) {  /* over rows of C in those columns */
1215       r1 = 0.0;
1216       n  = a->i[i+1] - a->i[i];
1217       aj = a->j + a->i[i];
1218       aa = a->a + a->i[i];
1219 
1220       for (j=0; j<n; j++) {
1221         r1 += (*aa++)*b1[*aj++];
1222       }
1223       c[col*am + i] = r1;
1224     }
1225     b1 += bm;
1226   }
1227   ierr = PetscLogFlops(cn*(2.0*a->nz));CHKERRQ(ierr);
1228   ierr = MatDenseRestoreArray(B,&b);CHKERRQ(ierr);
1229   ierr = MatDenseRestoreArray(C,&c);CHKERRQ(ierr);
1230   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1231   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1232   PetscFunctionReturn(0);
1233 }
1234 
1235 /*
1236    Note very similar to MatMult_SeqAIJ(), should generate both codes from same base
1237 */
1238 #undef __FUNCT__
1239 #define __FUNCT__ "MatMatMultNumericAdd_SeqAIJ_SeqDense"
1240 PetscErrorCode MatMatMultNumericAdd_SeqAIJ_SeqDense(Mat A,Mat B,Mat C)
1241 {
1242   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data;
1243   PetscErrorCode ierr;
1244   PetscScalar    *b,*c,r1,r2,r3,r4,*b1,*b2,*b3,*b4;
1245   MatScalar      *aa;
1246   PetscInt       cm  = C->rmap->n, cn=B->cmap->n, bm=B->rmap->n, col, i,j,n,*aj, am = A->rmap->n,*ii,arm;
1247   PetscInt       am2 = 2*am, am3 = 3*am,  bm4 = 4*bm,colam,*ridx;
1248 
1249   PetscFunctionBegin;
1250   if (!cm || !cn) PetscFunctionReturn(0);
1251   ierr = MatDenseGetArray(B,&b);CHKERRQ(ierr);
1252   ierr = MatDenseGetArray(C,&c);CHKERRQ(ierr);
1253   b1   = b; b2 = b1 + bm; b3 = b2 + bm; b4 = b3 + bm;
1254 
1255   if (a->compressedrow.use) { /* use compressed row format */
1256     for (col=0; col<cn-4; col += 4) {  /* over columns of C */
1257       colam = col*am;
1258       arm   = a->compressedrow.nrows;
1259       ii    = a->compressedrow.i;
1260       ridx  = a->compressedrow.rindex;
1261       for (i=0; i<arm; i++) {        /* over rows of C in those columns */
1262         r1 = r2 = r3 = r4 = 0.0;
1263         n  = ii[i+1] - ii[i];
1264         aj = a->j + ii[i];
1265         aa = a->a + ii[i];
1266         for (j=0; j<n; j++) {
1267           r1 += (*aa)*b1[*aj];
1268           r2 += (*aa)*b2[*aj];
1269           r3 += (*aa)*b3[*aj];
1270           r4 += (*aa++)*b4[*aj++];
1271         }
1272         c[colam       + ridx[i]] += r1;
1273         c[colam + am  + ridx[i]] += r2;
1274         c[colam + am2 + ridx[i]] += r3;
1275         c[colam + am3 + ridx[i]] += r4;
1276       }
1277       b1 += bm4;
1278       b2 += bm4;
1279       b3 += bm4;
1280       b4 += bm4;
1281     }
1282     for (; col<cn; col++) {     /* over extra columns of C */
1283       colam = col*am;
1284       arm   = a->compressedrow.nrows;
1285       ii    = a->compressedrow.i;
1286       ridx  = a->compressedrow.rindex;
1287       for (i=0; i<arm; i++) {  /* over rows of C in those columns */
1288         r1 = 0.0;
1289         n  = ii[i+1] - ii[i];
1290         aj = a->j + ii[i];
1291         aa = a->a + ii[i];
1292 
1293         for (j=0; j<n; j++) {
1294           r1 += (*aa++)*b1[*aj++];
1295         }
1296         c[colam + ridx[i]] += r1;
1297       }
1298       b1 += bm;
1299     }
1300   } else {
1301     for (col=0; col<cn-4; col += 4) {  /* over columns of C */
1302       colam = col*am;
1303       for (i=0; i<am; i++) {        /* over rows of C in those columns */
1304         r1 = r2 = r3 = r4 = 0.0;
1305         n  = a->i[i+1] - a->i[i];
1306         aj = a->j + a->i[i];
1307         aa = a->a + a->i[i];
1308         for (j=0; j<n; j++) {
1309           r1 += (*aa)*b1[*aj];
1310           r2 += (*aa)*b2[*aj];
1311           r3 += (*aa)*b3[*aj];
1312           r4 += (*aa++)*b4[*aj++];
1313         }
1314         c[colam + i]       += r1;
1315         c[colam + am + i]  += r2;
1316         c[colam + am2 + i] += r3;
1317         c[colam + am3 + i] += r4;
1318       }
1319       b1 += bm4;
1320       b2 += bm4;
1321       b3 += bm4;
1322       b4 += bm4;
1323     }
1324     for (; col<cn; col++) {     /* over extra columns of C */
1325       colam = col*am;
1326       for (i=0; i<am; i++) {  /* over rows of C in those columns */
1327         r1 = 0.0;
1328         n  = a->i[i+1] - a->i[i];
1329         aj = a->j + a->i[i];
1330         aa = a->a + a->i[i];
1331 
1332         for (j=0; j<n; j++) {
1333           r1 += (*aa++)*b1[*aj++];
1334         }
1335         c[colam + i] += r1;
1336       }
1337       b1 += bm;
1338     }
1339   }
1340   ierr = PetscLogFlops(cn*2.0*a->nz);CHKERRQ(ierr);
1341   ierr = MatDenseRestoreArray(B,&b);CHKERRQ(ierr);
1342   ierr = MatDenseRestoreArray(C,&c);CHKERRQ(ierr);
1343   PetscFunctionReturn(0);
1344 }
1345 
1346 #undef __FUNCT__
1347 #define __FUNCT__ "MatTransColoringApplySpToDen_SeqAIJ"
1348 PetscErrorCode  MatTransColoringApplySpToDen_SeqAIJ(MatTransposeColoring coloring,Mat B,Mat Btdense)
1349 {
1350   PetscErrorCode ierr;
1351   Mat_SeqAIJ     *b       = (Mat_SeqAIJ*)B->data;
1352   Mat_SeqDense   *btdense = (Mat_SeqDense*)Btdense->data;
1353   PetscInt       *bi      = b->i,*bj=b->j;
1354   PetscInt       m        = Btdense->rmap->n,n=Btdense->cmap->n,j,k,l,col,anz,*btcol,brow,ncolumns;
1355   MatScalar      *btval,*btval_den,*ba=b->a;
1356   PetscInt       *columns=coloring->columns,*colorforcol=coloring->colorforcol,ncolors=coloring->ncolors;
1357 
1358   PetscFunctionBegin;
1359   btval_den=btdense->v;
1360   ierr     = PetscMemzero(btval_den,(m*n)*sizeof(MatScalar));CHKERRQ(ierr);
1361   for (k=0; k<ncolors; k++) {
1362     ncolumns = coloring->ncolumns[k];
1363     for (l=0; l<ncolumns; l++) { /* insert a row of B to a column of Btdense */
1364       col   = *(columns + colorforcol[k] + l);
1365       btcol = bj + bi[col];
1366       btval = ba + bi[col];
1367       anz   = bi[col+1] - bi[col];
1368       for (j=0; j<anz; j++) {
1369         brow            = btcol[j];
1370         btval_den[brow] = btval[j];
1371       }
1372     }
1373     btval_den += m;
1374   }
1375   PetscFunctionReturn(0);
1376 }
1377 
1378 #undef __FUNCT__
1379 #define __FUNCT__ "MatTransColoringApplyDenToSp_SeqAIJ"
1380 PetscErrorCode MatTransColoringApplyDenToSp_SeqAIJ(MatTransposeColoring matcoloring,Mat Cden,Mat Csp)
1381 {
1382   PetscErrorCode ierr;
1383   Mat_SeqAIJ     *csp = (Mat_SeqAIJ*)Csp->data;
1384   PetscInt       k,l,*row,*idx,m,ncolors=matcoloring->ncolors,nrows;
1385   PetscScalar    *ca_den,*cp_den,*ca=csp->a;
1386   PetscInt       *rows=matcoloring->rows,*spidx=matcoloring->columnsforspidx,*colorforrow=matcoloring->colorforrow;
1387 
1388   PetscFunctionBegin;
1389   ierr   = MatGetLocalSize(Csp,&m,NULL);CHKERRQ(ierr);
1390   ierr   = MatDenseGetArray(Cden,&ca_den);CHKERRQ(ierr);
1391   cp_den = ca_den;
1392   for (k=0; k<ncolors; k++) {
1393     nrows = matcoloring->nrows[k];
1394     row   = rows  + colorforrow[k];
1395     idx   = spidx + colorforrow[k];
1396     for (l=0; l<nrows; l++) {
1397       ca[idx[l]] = cp_den[row[l]];
1398     }
1399     cp_den += m;
1400   }
1401   ierr = MatDenseRestoreArray(Cden,&ca_den);CHKERRQ(ierr);
1402   PetscFunctionReturn(0);
1403 }
1404 
1405 /*
1406  MatGetColumnIJ_SeqAIJ_Color() and MatRestoreColumnIJ_SeqAIJ_Color() are customized from
1407  MatGetColumnIJ_SeqAIJ() and MatRestoreColumnIJ_SeqAIJ() by adding an output
1408  spidx[], index of a->j, to be used for setting 'columnsforspidx' in MatTransposeColoringCreate_SeqAIJ().
1409  */
1410 #undef __FUNCT__
1411 #define __FUNCT__ "MatGetColumnIJ_SeqAIJ_Color"
1412 PetscErrorCode MatGetColumnIJ_SeqAIJ_Color(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool inodecompressed,PetscInt *nn,const PetscInt *ia[],const PetscInt *ja[],PetscInt *spidx[],PetscBool  *done)
1413 {
1414   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
1415   PetscErrorCode ierr;
1416   PetscInt       i,*collengths,*cia,*cja,n = A->cmap->n,m = A->rmap->n;
1417   PetscInt       nz = a->i[m],row,*jj,mr,col;
1418   PetscInt       *cspidx;
1419 
1420   PetscFunctionBegin;
1421   *nn = n;
1422   if (!ia) PetscFunctionReturn(0);
1423   if (symmetric) {
1424     SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"MatGetColumnIJ_SeqAIJ_Color() not supported for the case symmetric");
1425     ierr = MatToSymmetricIJ_SeqAIJ(A->rmap->n,a->i,a->j,0,oshift,(PetscInt**)ia,(PetscInt**)ja);CHKERRQ(ierr);
1426   } else {
1427     ierr = PetscMalloc((n+1)*sizeof(PetscInt),&collengths);CHKERRQ(ierr);
1428     ierr = PetscMemzero(collengths,n*sizeof(PetscInt));CHKERRQ(ierr);
1429     ierr = PetscMalloc((n+1)*sizeof(PetscInt),&cia);CHKERRQ(ierr);
1430     ierr = PetscMalloc((nz+1)*sizeof(PetscInt),&cja);CHKERRQ(ierr);
1431     ierr = PetscMalloc((nz+1)*sizeof(PetscInt),&cspidx);CHKERRQ(ierr);
1432     jj   = a->j;
1433     for (i=0; i<nz; i++) {
1434       collengths[jj[i]]++;
1435     }
1436     cia[0] = oshift;
1437     for (i=0; i<n; i++) {
1438       cia[i+1] = cia[i] + collengths[i];
1439     }
1440     ierr = PetscMemzero(collengths,n*sizeof(PetscInt));CHKERRQ(ierr);
1441     jj   = a->j;
1442     for (row=0; row<m; row++) {
1443       mr = a->i[row+1] - a->i[row];
1444       for (i=0; i<mr; i++) {
1445         col = *jj++;
1446 
1447         cspidx[cia[col] + collengths[col] - oshift] = a->i[row] + i; /* index of a->j */
1448         cja[cia[col] + collengths[col]++ - oshift]  = row + oshift;
1449       }
1450     }
1451     ierr   = PetscFree(collengths);CHKERRQ(ierr);
1452     *ia    = cia; *ja = cja;
1453     *spidx = cspidx;
1454   }
1455   PetscFunctionReturn(0);
1456 }
1457 
1458 #undef __FUNCT__
1459 #define __FUNCT__ "MatRestoreColumnIJ_SeqAIJ_Color"
1460 PetscErrorCode MatRestoreColumnIJ_SeqAIJ_Color(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool inodecompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscInt *spidx[],PetscBool  *done)
1461 {
1462   PetscErrorCode ierr;
1463 
1464   PetscFunctionBegin;
1465   if (!ia) PetscFunctionReturn(0);
1466 
1467   ierr = PetscFree(*ia);CHKERRQ(ierr);
1468   ierr = PetscFree(*ja);CHKERRQ(ierr);
1469   ierr = PetscFree(*spidx);CHKERRQ(ierr);
1470   PetscFunctionReturn(0);
1471 }
1472 
1473 #undef __FUNCT__
1474 #define __FUNCT__ "MatTransposeColoringCreate_SeqAIJ"
1475 PetscErrorCode MatTransposeColoringCreate_SeqAIJ(Mat mat,ISColoring iscoloring,MatTransposeColoring c)
1476 {
1477   PetscErrorCode ierr;
1478   PetscInt       i,n,nrows,N,j,k,m,ncols,col,cm;
1479   const PetscInt *is,*ci,*cj,*row_idx;
1480   PetscInt       nis = iscoloring->n,*rowhit,bs = 1;
1481   IS             *isa;
1482   PetscBool      flg1,flg2;
1483   Mat_SeqAIJ     *csp = (Mat_SeqAIJ*)mat->data;
1484   PetscInt       *colorforrow,*rows,*rows_i,*columnsforspidx,*columnsforspidx_i,*idxhit,*spidx;
1485   PetscInt       *colorforcol,*columns,*columns_i;
1486 
1487   PetscFunctionBegin;
1488   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
1489 
1490   /* this is ugly way to get blocksize but cannot call MatGetBlockSize() because AIJ can have bs > 1 */
1491   ierr = PetscObjectTypeCompare((PetscObject)mat,MATSEQBAIJ,&flg1);CHKERRQ(ierr);
1492   ierr = PetscObjectTypeCompare((PetscObject)mat,MATMPIBAIJ,&flg2);CHKERRQ(ierr);
1493   if (flg1 || flg2) {
1494     ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
1495   }
1496 
1497   N         = mat->cmap->N/bs;
1498   c->M      = mat->rmap->N/bs;  /* set total rows, columns and local rows */
1499   c->N      = mat->cmap->N/bs;
1500   c->m      = mat->rmap->N/bs;
1501   c->rstart = 0;
1502 
1503   c->ncolors = nis;
1504   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
1505   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
1506   ierr       = PetscMalloc2(csp->nz+1,PetscInt,&rows,csp->nz+1,PetscInt,&columnsforspidx);CHKERRQ(ierr);
1507   ierr       = PetscMalloc((nis+1)*sizeof(PetscInt),&colorforrow);CHKERRQ(ierr);
1508 
1509   colorforrow[0]    = 0;
1510   rows_i            = rows;
1511   columnsforspidx_i = columnsforspidx;
1512 
1513   ierr = PetscMalloc((nis+1)*sizeof(PetscInt),&colorforcol);CHKERRQ(ierr);
1514   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&columns);CHKERRQ(ierr);
1515 
1516   colorforcol[0] = 0;
1517   columns_i      = columns;
1518 
1519   ierr = MatGetColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr); /* column-wise storage of mat */
1520 
1521   cm   = c->m;
1522   ierr = PetscMalloc((cm+1)*sizeof(PetscInt),&rowhit);CHKERRQ(ierr);
1523   ierr = PetscMalloc((cm+1)*sizeof(PetscInt),&idxhit);CHKERRQ(ierr);
1524   for (i=0; i<nis; i++) {
1525     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
1526     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
1527 
1528     c->ncolumns[i] = n;
1529     if (n) {
1530       ierr = PetscMemcpy(columns_i,is,n*sizeof(PetscInt));CHKERRQ(ierr);
1531     }
1532     colorforcol[i+1] = colorforcol[i] + n;
1533     columns_i       += n;
1534 
1535     /* fast, crude version requires O(N*N) work */
1536     ierr = PetscMemzero(rowhit,cm*sizeof(PetscInt));CHKERRQ(ierr);
1537 
1538     /* loop over columns*/
1539     for (j=0; j<n; j++) {
1540       col     = is[j];
1541       row_idx = cj + ci[col];
1542       m       = ci[col+1] - ci[col];
1543       /* loop over columns marking them in rowhit */
1544       for (k=0; k<m; k++) {
1545         idxhit[*row_idx]   = spidx[ci[col] + k];
1546         rowhit[*row_idx++] = col + 1;
1547       }
1548     }
1549     /* count the number of hits */
1550     nrows = 0;
1551     for (j=0; j<cm; j++) {
1552       if (rowhit[j]) nrows++;
1553     }
1554     c->nrows[i]      = nrows;
1555     colorforrow[i+1] = colorforrow[i] + nrows;
1556 
1557     nrows = 0;
1558     for (j=0; j<cm; j++) {
1559       if (rowhit[j]) {
1560         rows_i[nrows]            = j;
1561         columnsforspidx_i[nrows] = idxhit[j];
1562         nrows++;
1563       }
1564     }
1565     ierr    = ISRestoreIndices(isa[i],&is);CHKERRQ(ierr);
1566     rows_i += nrows; columnsforspidx_i += nrows;
1567   }
1568   ierr = MatRestoreColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
1569   ierr = PetscFree(rowhit);CHKERRQ(ierr);
1570   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
1571 #if defined(PETSC_USE_DEBUG)
1572   if (csp->nz != colorforrow[nis]) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"csp->nz %d != colorforrow[nis] %d",csp->nz,colorforrow[nis]);
1573 #endif
1574 
1575   c->colorforrow     = colorforrow;
1576   c->rows            = rows;
1577   c->columnsforspidx = columnsforspidx;
1578   c->colorforcol     = colorforcol;
1579   c->columns         = columns;
1580 
1581   ierr = PetscFree(idxhit);CHKERRQ(ierr);
1582   PetscFunctionReturn(0);
1583 }
1584