xref: /petsc/src/mat/impls/aij/seq/matrart.c (revision 235162ce3537ea98be83a1ac893e389d13562573)
1 
2 /*
3   Defines projective product routines where A is a SeqAIJ matrix
4           C = R * A * R^T
5 */
6 
7 #include <../src/mat/impls/aij/seq/aij.h>
8 #include <../src/mat/utils/freespace.h>
9 #include <../src/mat/impls/dense/seq/dense.h> /*I "petscmat.h" I*/
10 
11 #undef __FUNCT__
12 #define __FUNCT__ "MatDestroy_SeqAIJ_RARt"
13 PetscErrorCode MatDestroy_SeqAIJ_RARt(Mat A)
14 {
15   PetscErrorCode ierr;
16   Mat_SeqAIJ     *a    = (Mat_SeqAIJ*)A->data;
17   Mat_RARt       *rart = a->rart;
18 
19   PetscFunctionBegin;
20   ierr = MatTransposeColoringDestroy(&rart->matcoloring);CHKERRQ(ierr);
21   ierr = MatDestroy(&rart->Rt);CHKERRQ(ierr);
22   ierr = MatDestroy(&rart->RARt);CHKERRQ(ierr);
23   ierr = MatDestroy(&rart->ARt);CHKERRQ(ierr);
24   ierr = PetscFree(rart->work);CHKERRQ(ierr);
25 
26   A->ops->destroy = rart->destroy;
27   if (A->ops->destroy) {
28     ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
29   }
30   ierr = PetscFree(rart);CHKERRQ(ierr);
31   PetscFunctionReturn(0);
32 }
33 
34 #undef __FUNCT__
35 #define __FUNCT__ "MatRARtSymbolic_SeqAIJ_SeqAIJ_colorrart"
36 PetscErrorCode MatRARtSymbolic_SeqAIJ_SeqAIJ_colorrart(Mat A,Mat R,PetscReal fill,Mat *C)
37 {
38   PetscErrorCode       ierr;
39   Mat                  P;
40   PetscInt             *rti,*rtj;
41   Mat_RARt             *rart;
42   MatTransposeColoring matcoloring;
43   ISColoring           iscoloring;
44   Mat                  Rt_dense,RARt_dense;
45   Mat_SeqAIJ           *c;
46 
47   PetscFunctionBegin;
48   /* create symbolic P=Rt */
49   ierr = MatGetSymbolicTranspose_SeqAIJ(R,&rti,&rtj);CHKERRQ(ierr);
50   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,R->cmap->n,R->rmap->n,rti,rtj,NULL,&P);CHKERRQ(ierr);
51 
52   /* get symbolic C=Pt*A*P */
53   ierr           = MatPtAPSymbolic_SeqAIJ_SeqAIJ_SparseAxpy(A,P,fill,C);CHKERRQ(ierr);
54   (*C)->rmap->bs = R->rmap->bs;
55   (*C)->cmap->bs = R->rmap->bs;
56   (*C)->ops->rartnumeric = MatRARtNumeric_SeqAIJ_SeqAIJ_colorrart;
57 
58   /* create a supporting struct */
59   ierr    = PetscNew(Mat_RARt,&rart);CHKERRQ(ierr);
60   c       = (Mat_SeqAIJ*)(*C)->data;
61   c->rart = rart;
62 
63   /* ------ Use coloring ---------- */
64   /* inode causes memory problem, don't know why */
65   if (c->inode.use) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"MAT_USE_INODES is not supported. Use '-mat_no_inode'");
66 
67   /* Create MatTransposeColoring from symbolic C=R*A*R^T */
68   ierr = MatGetColoring(*C,MATCOLORINGLF,&iscoloring);CHKERRQ(ierr);
69   ierr = MatTransposeColoringCreate(*C,iscoloring,&matcoloring);CHKERRQ(ierr);
70 
71   rart->matcoloring = matcoloring;
72   ierr = ISColoringDestroy(&iscoloring);CHKERRQ(ierr);
73 
74   /* Create Rt_dense */
75   ierr = MatCreate(PETSC_COMM_SELF,&Rt_dense);CHKERRQ(ierr);
76   ierr = MatSetSizes(Rt_dense,A->cmap->n,matcoloring->ncolors,A->cmap->n,matcoloring->ncolors);CHKERRQ(ierr);
77   ierr = MatSetType(Rt_dense,MATSEQDENSE);CHKERRQ(ierr);
78   ierr = MatSeqDenseSetPreallocation(Rt_dense,NULL);CHKERRQ(ierr);
79 
80   Rt_dense->assembled = PETSC_TRUE;
81   rart->Rt            = Rt_dense;
82 
83   /* Create RARt_dense = R*A*Rt_dense */
84   ierr = MatCreate(PETSC_COMM_SELF,&RARt_dense);CHKERRQ(ierr);
85   ierr = MatSetSizes(RARt_dense,(*C)->rmap->n,matcoloring->ncolors,(*C)->rmap->n,matcoloring->ncolors);CHKERRQ(ierr);
86   ierr = MatSetType(RARt_dense,MATSEQDENSE);CHKERRQ(ierr);
87   ierr = MatSeqDenseSetPreallocation(RARt_dense,NULL);CHKERRQ(ierr);
88 
89   rart->RARt = RARt_dense;
90 
91   /* Allocate work array to store columns of A*R^T used in MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqDense() */
92   ierr = PetscMalloc(A->rmap->n*4*sizeof(PetscScalar),&rart->work);CHKERRQ(ierr);
93 
94   rart->destroy      = (*C)->ops->destroy;
95   (*C)->ops->destroy = MatDestroy_SeqAIJ_RARt;
96 
97   /* clean up */
98   ierr = MatRestoreSymbolicTranspose_SeqAIJ(R,&rti,&rtj);CHKERRQ(ierr);
99   ierr = MatDestroy(&P);CHKERRQ(ierr);
100 
101 #if defined(PETSC_USE_INFO)
102   {
103     PetscReal density= (PetscReal)(c->nz)/(RARt_dense->rmap->n*RARt_dense->cmap->n);
104     ierr = PetscInfo(*C,"C=R*(A*Rt) via coloring C - use sparse-dense inner products\n");CHKERRQ(ierr);
105     ierr = PetscInfo6(*C,"RARt_den %D %D; Rt %D %D (RARt->nz %D)/(m*ncolors)=%g\n",RARt_dense->rmap->n,RARt_dense->cmap->n,R->cmap->n,R->rmap->n,c->nz,density);CHKERRQ(ierr);
106   }
107 #endif
108   PetscFunctionReturn(0);
109 }
110 
111 /*
112  RAB = R * A * B, R and A in seqaij format, B in dense format;
113 */
114 #undef __FUNCT__
115 #define __FUNCT__ "MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqDense"
116 PetscErrorCode MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqDense(Mat R,Mat A,Mat B,Mat RAB,PetscScalar *work)
117 {
118   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data,*r=(Mat_SeqAIJ*)R->data;
119   PetscErrorCode ierr;
120   PetscScalar    *b,r1,r2,r3,r4,*b1,*b2,*b3,*b4;
121   MatScalar      *aa,*ra;
122   PetscInt       cn =B->cmap->n,bm=B->rmap->n,col,i,j,n,*ai=a->i,*aj,am=A->rmap->n;
123   PetscInt       am2=2*am,am3=3*am,bm4=4*bm;
124   PetscScalar    *d,*c,*c2,*c3,*c4;
125   PetscInt       *rj,rm=R->rmap->n,dm=RAB->rmap->n,dn=RAB->cmap->n;
126   PetscInt       rm2=2*rm,rm3=3*rm,colrm;
127 
128   PetscFunctionBegin;
129   if (!dm || !dn) PetscFunctionReturn(0);
130   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);
131   if (am != R->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number columns in R %D not equal rows in A %D\n",R->cmap->n,am);
132   if (R->rmap->n != RAB->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number rows in RAB %D not equal rows in R %D\n",RAB->rmap->n,R->rmap->n);
133   if (B->cmap->n != RAB->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number columns in RAB %D not equal columns in B %D\n",RAB->cmap->n,B->cmap->n);
134 
135   { /*
136      This approach is not as good as original ones (will be removed later), but it reveals that
137      AB_den=A*B takes almost all execution time in R*A*B for src/ksp/ksp/examples/tutorials/ex56.c
138      */
139     PetscBool via_matmatmult=PETSC_FALSE;
140     ierr = PetscOptionsGetBool(NULL,"-matrart_via_matmatmult",&via_matmatmult,NULL);CHKERRQ(ierr);
141     if (via_matmatmult) {
142       Mat AB_den;
143       ierr = MatMatMultSymbolic_SeqAIJ_SeqDense(A,B,0.0,&AB_den);CHKERRQ(ierr);
144       ierr = MatMatMultNumeric_SeqAIJ_SeqDense(A,B,AB_den);CHKERRQ(ierr);
145       ierr = MatMatMultNumeric_SeqAIJ_SeqDense(R,AB_den,RAB);CHKERRQ(ierr);
146       ierr = MatDestroy(&AB_den);CHKERRQ(ierr);
147       PetscFunctionReturn(0);
148     }
149   }
150 
151   ierr = MatDenseGetArray(B,&b);CHKERRQ(ierr);
152   ierr = MatDenseGetArray(RAB,&d);CHKERRQ(ierr);
153   b1   = b; b2 = b1 + bm; b3 = b2 + bm; b4 = b3 + bm;
154   c    = work; c2 = c + am; c3 = c2 + am; c4 = c3 + am;
155   for (col=0; col<cn-4; col += 4) {  /* over columns of C */
156     for (i=0; i<am; i++) {        /* over rows of A in those columns */
157       r1 = r2 = r3 = r4 = 0.0;
158       n  = ai[i+1] - ai[i];
159       aj = a->j + ai[i];
160       aa = a->a + ai[i];
161       for (j=0; j<n; j++) {
162         r1 += (*aa)*b1[*aj];
163         r2 += (*aa)*b2[*aj];
164         r3 += (*aa)*b3[*aj];
165         r4 += (*aa++)*b4[*aj++];
166       }
167       c[i]       = r1;
168       c[am  + i] = r2;
169       c[am2 + i] = r3;
170       c[am3 + i] = r4;
171     }
172     b1 += bm4;
173     b2 += bm4;
174     b3 += bm4;
175     b4 += bm4;
176 
177     /* RAB[:,col] = R*C[:,col] */
178     colrm = col*rm;
179     for (i=0; i<rm; i++) {        /* over rows of R in those columns */
180       r1 = r2 = r3 = r4 = 0.0;
181       n  = r->i[i+1] - r->i[i];
182       rj = r->j + r->i[i];
183       ra = r->a + r->i[i];
184       for (j=0; j<n; j++) {
185         r1 += (*ra)*c[*rj];
186         r2 += (*ra)*c2[*rj];
187         r3 += (*ra)*c3[*rj];
188         r4 += (*ra++)*c4[*rj++];
189       }
190       d[colrm + i]       = r1;
191       d[colrm + rm + i]  = r2;
192       d[colrm + rm2 + i] = r3;
193       d[colrm + rm3 + i] = r4;
194     }
195   }
196   for (; col<cn; col++) {     /* over extra columns of C */
197     for (i=0; i<am; i++) {  /* over rows of A in those columns */
198       r1 = 0.0;
199       n  = a->i[i+1] - a->i[i];
200       aj = a->j + a->i[i];
201       aa = a->a + a->i[i];
202       for (j=0; j<n; j++) {
203         r1 += (*aa++)*b1[*aj++];
204       }
205       c[i] = r1;
206     }
207     b1 += bm;
208 
209     for (i=0; i<rm; i++) {  /* over rows of R in those columns */
210       r1 = 0.0;
211       n  = r->i[i+1] - r->i[i];
212       rj = r->j + r->i[i];
213       ra = r->a + r->i[i];
214       for (j=0; j<n; j++) {
215         r1 += (*ra++)*c[*rj++];
216       }
217       d[col*rm + i] = r1;
218     }
219   }
220   ierr = PetscLogFlops(cn*2.0*(a->nz + r->nz));CHKERRQ(ierr);
221 
222   ierr = MatDenseRestoreArray(B,&b);CHKERRQ(ierr);
223   ierr = MatDenseRestoreArray(RAB,&d);CHKERRQ(ierr);
224   ierr = MatAssemblyBegin(RAB,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
225   ierr = MatAssemblyEnd(RAB,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
226   PetscFunctionReturn(0);
227 }
228 
229 #undef __FUNCT__
230 #define __FUNCT__ "MatRARtNumeric_SeqAIJ_SeqAIJ_colorrart"
231 PetscErrorCode MatRARtNumeric_SeqAIJ_SeqAIJ_colorrart(Mat A,Mat R,Mat C)
232 {
233   PetscErrorCode       ierr;
234   Mat_SeqAIJ           *c = (Mat_SeqAIJ*)C->data;
235   Mat_RARt             *rart=c->rart;
236   MatTransposeColoring matcoloring;
237   Mat                  Rt,RARt;
238 
239   PetscFunctionBegin;
240   /* Get dense Rt by Apply MatTransposeColoring to R */
241   matcoloring = rart->matcoloring;
242   Rt          = rart->Rt;
243   ierr  = MatTransColoringApplySpToDen(matcoloring,R,Rt);CHKERRQ(ierr);
244 
245   /* Get dense RARt = R*A*Rt -- dominates! */
246   RARt = rart->RARt;
247   ierr = MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqDense(R,A,Rt,RARt,rart->work);CHKERRQ(ierr);
248 
249   /* Recover C from C_dense */
250   ierr = MatTransColoringApplyDenToSp(matcoloring,RARt,C);CHKERRQ(ierr);
251   PetscFunctionReturn(0);
252 }
253 
254 #undef __FUNCT__
255 #define __FUNCT__ "MatRARtSymbolic_SeqAIJ_SeqAIJ_matmattransposemult"
256 PetscErrorCode MatRARtSymbolic_SeqAIJ_SeqAIJ_matmattransposemult(Mat A,Mat R,PetscReal fill,Mat *C)
257 {
258   PetscErrorCode  ierr;
259   Mat             ARt,RARt;
260   Mat_SeqAIJ     *c;
261   Mat_RARt       *rart;
262 
263   PetscFunctionBegin;
264   /* must use '-mat_no_inode' with '-matmattransmult_color 1' - do not knwo why? */
265   ierr = MatMatTransposeMultSymbolic_SeqAIJ_SeqAIJ(A,R,fill,&ARt);CHKERRQ(ierr);
266   ierr = MatMatMultSymbolic_SeqAIJ_SeqAIJ(R,ARt,fill,&RARt);CHKERRQ(ierr);
267   *C                     = RARt;
268   RARt->ops->rartnumeric = MatRARtNumeric_SeqAIJ_SeqAIJ_matmattransposemult;
269 
270   ierr = PetscNew(Mat_RARt,&rart);CHKERRQ(ierr);
271   c         = (Mat_SeqAIJ*)(*C)->data;
272   c->rart   = rart;
273   rart->ARt = ARt;
274   rart->destroy      = RARt->ops->destroy;
275   RARt->ops->destroy = MatDestroy_SeqAIJ_RARt;
276 #if defined(PETSC_USE_INFO)
277   ierr = PetscInfo(*C,"Use ARt=A*R^T, C=R*ARt via MatMatTransposeMult(). Coloring can be applied to A*R^T.\n");CHKERRQ(ierr);
278 #endif
279   PetscFunctionReturn(0);
280 }
281 
282 #undef __FUNCT__
283 #define __FUNCT__ "MatRARtNumeric_SeqAIJ_SeqAIJ_matmattransposemult"
284 PetscErrorCode MatRARtNumeric_SeqAIJ_SeqAIJ_matmattransposemult(Mat A,Mat R,Mat C)
285 {
286   PetscErrorCode  ierr;
287   Mat_SeqAIJ      *c=(Mat_SeqAIJ*)C->data;
288   Mat_RARt        *rart=c->rart;
289   Mat             ARt=rart->ARt;
290 
291   PetscFunctionBegin;
292   ierr = MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ(A,R,ARt);CHKERRQ(ierr); /* dominate! */
293   ierr = MatMatMultNumeric_SeqAIJ_SeqAIJ(R,ARt,C);CHKERRQ(ierr);
294   PetscFunctionReturn(0);
295 }
296 
297 #undef __FUNCT__
298 #define __FUNCT__ "MatRARtSymbolic_SeqAIJ_SeqAIJ"
299 PetscErrorCode MatRARtSymbolic_SeqAIJ_SeqAIJ(Mat A,Mat R,PetscReal fill,Mat *C)
300 {
301   PetscErrorCode  ierr;
302   Mat             Rt;
303   Mat_SeqAIJ      *c;
304   Mat_RARt        *rart;
305 
306   PetscFunctionBegin;
307   ierr = MatTranspose_SeqAIJ(R,MAT_INITIAL_MATRIX,&Rt);CHKERRQ(ierr);
308   ierr = MatMatMatMultSymbolic_SeqAIJ_SeqAIJ_SeqAIJ(R,A,Rt,fill,C);CHKERRQ(ierr);
309 
310   ierr = PetscNew(Mat_RARt,&rart);CHKERRQ(ierr);
311   rart->Rt = Rt;
312   c        = (Mat_SeqAIJ*)(*C)->data;
313   c->rart  = rart;
314   rart->destroy          = (*C)->ops->destroy;
315   (*C)->ops->destroy     = MatDestroy_SeqAIJ_RARt;
316   (*C)->ops->rartnumeric = MatRARtNumeric_SeqAIJ_SeqAIJ;
317 #if defined(PETSC_USE_INFO)
318   ierr = PetscInfo(*C,"Use Rt=R^T and C=R*A*Rt via MatMatMatMult() to avoid sparse inner products\n");CHKERRQ(ierr);
319 #endif
320   PetscFunctionReturn(0);
321 }
322 
323 #undef __FUNCT__
324 #define __FUNCT__ "MatRARtNumeric_SeqAIJ_SeqAIJ"
325 PetscErrorCode MatRARtNumeric_SeqAIJ_SeqAIJ(Mat A,Mat R,Mat C)
326 {
327   PetscErrorCode  ierr;
328   Mat_SeqAIJ      *c = (Mat_SeqAIJ*)C->data;
329   Mat_RARt        *rart = c->rart;
330   Mat             Rt = rart->Rt;
331 
332   PetscFunctionBegin;
333   ierr = MatTranspose_SeqAIJ(R,MAT_REUSE_MATRIX,&Rt);CHKERRQ(ierr);
334   ierr = MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqAIJ(R,A,Rt,C);CHKERRQ(ierr);
335   PetscFunctionReturn(0);
336 }
337 
338 #undef __FUNCT__
339 #define __FUNCT__ "MatRARt_SeqAIJ_SeqAIJ"
340 PetscErrorCode MatRARt_SeqAIJ_SeqAIJ(Mat A,Mat R,MatReuse scall,PetscReal fill,Mat *C)
341 {
342   PetscErrorCode ierr;
343   const char     *algTypes[3] = {"matmatmatmult","matmattransposemult","coloring_rart"};
344   PetscInt       alg=0; /* set default algorithm */
345 
346   PetscFunctionBegin;
347   if (scall == MAT_INITIAL_MATRIX) {
348     ierr = PetscObjectOptionsBegin((PetscObject)A);CHKERRQ(ierr);
349     ierr = PetscOptionsEList("-matrart_via","Algorithmic approach","MatRARt",algTypes,3,algTypes[0],&alg,NULL);CHKERRQ(ierr);
350     ierr = PetscOptionsEnd();CHKERRQ(ierr);
351 
352     ierr = PetscLogEventBegin(MAT_RARtSymbolic,A,R,0,0);CHKERRQ(ierr);
353     switch (alg) {
354     case 1:
355       /* via matmattransposemult: ARt=A*R^T, C=R*ARt - matrix coloring can be applied to A*R^T */
356       ierr = MatRARtSymbolic_SeqAIJ_SeqAIJ_matmattransposemult(A,R,fill,C);CHKERRQ(ierr);
357       break;
358     case 2:
359       /* via coloring_rart: apply coloring C = R*A*R^T                          */
360       ierr = MatRARtSymbolic_SeqAIJ_SeqAIJ_colorrart(A,R,fill,C);CHKERRQ(ierr);
361       break;
362     default:
363       /* via matmatmatmult: Rt=R^T, C=R*A*Rt - avoid inefficient sparse inner products */
364       ierr = MatRARtSymbolic_SeqAIJ_SeqAIJ(A,R,fill,C);CHKERRQ(ierr);
365       break;
366     }
367     ierr = PetscLogEventEnd(MAT_RARtSymbolic,A,R,0,0);CHKERRQ(ierr);
368   }
369 
370   ierr = PetscLogEventBegin(MAT_RARtNumeric,A,R,0,0);CHKERRQ(ierr);
371   ierr = (*(*C)->ops->rartnumeric)(A,R,*C);CHKERRQ(ierr);
372   ierr = PetscLogEventEnd(MAT_RARtNumeric,A,R,0,0);CHKERRQ(ierr);
373   PetscFunctionReturn(0);
374 }
375