/[escript]/branches/doubleplusgood/paso/src/RILU.cpp
ViewVC logotype

Contents of /branches/doubleplusgood/paso/src/RILU.cpp

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1975 - (show annotations)
Thu Nov 6 03:07:02 2008 UTC (10 years, 6 months ago) by artak
Original Path: trunk/paso/src/Solver_RILU.c
File MIME type: text/plain
File size: 15862 byte(s)
Some variables are initialized to get rid of compiler warnings
1
2 /*******************************************************
3 *
4 * Copyright (c) 2003-2008 by University of Queensland
5 * Earth Systems Science Computational Center (ESSCC)
6 * http://www.uq.edu.au/esscc
7 *
8 * Primary Business: Queensland, Australia
9 * Licensed under the Open Software License version 3.0
10 * http://www.opensource.org/licenses/osl-3.0.php
11 *
12 *******************************************************/
13
14
15 /**************************************************************/
16
17 /* Paso: RILU preconditioner with reordering */
18
19 /**************************************************************/
20
21 /* Author: gross@access.edu.au */
22
23 /**************************************************************/
24
25 #include "Paso.h"
26 #include "Solver.h"
27 #include "PasoUtil.h"
28
29 /**************************************************************/
30
31 /* free all memory used by RILU */
32
33 void Paso_Solver_RILU_free(Paso_Solver_RILU * in) {
34 if (in!=NULL) {
35 Paso_Solver_RILU_free(in->RILU_of_Schur);
36 MEMFREE(in->inv_A_FF);
37 MEMFREE(in->A_FF_pivot);
38 Paso_SparseMatrix_free(in->A_FC);
39 Paso_SparseMatrix_free(in->A_CF);
40 MEMFREE(in->rows_in_F);
41 MEMFREE(in->rows_in_C);
42 MEMFREE(in->mask_F);
43 MEMFREE(in->mask_C);
44 MEMFREE(in->x_F);
45 MEMFREE(in->b_F);
46 MEMFREE(in->x_C);
47 MEMFREE(in->b_C);
48 MEMFREE(in);
49 }
50 }
51
52 /**************************************************************/
53
54 /* constructs the block-block factorization of
55
56 [ A_FF A_FC ]
57 A_p=
58 [ A_CF A_FF ]
59
60 to
61
62 [ I 0 ] [ A_FF 0 ] [ I invA_FF*A_FF ]
63 [ A_CF*invA_FF I ] [ 0 S ] [ 0 I ]
64
65
66 where S=A_FF-ACF*invA_FF*A_FC within the shape of S
67
68 then RILU is applied to S again until S becomes empty
69
70 */
71 Paso_Solver_RILU* Paso_Solver_getRILU(Paso_SparseMatrix *A_p,bool_t verbose) {
72 Paso_Solver_RILU* out=NULL;
73 dim_t n=A_p->numRows;
74 dim_t n_block=A_p->row_block_size;
75 index_t* mis_marker=NULL;
76 index_t* counter=NULL;
77 index_t iPtr,*index, *where_p;
78 dim_t i,k;
79 Paso_SparseMatrix * schur=NULL;
80 double A11,A12,A13,A21,A22,A23,A31,A32,A33,D,time0=0,time1=0,time2=0;
81
82
83 /* identify independend set of rows/columns */
84 mis_marker=TMPMEMALLOC(n,index_t);
85 counter=TMPMEMALLOC(n,index_t);
86 out=MEMALLOC(1,Paso_Solver_RILU);
87 out->RILU_of_Schur=NULL;
88 out->inv_A_FF=NULL;
89 out->A_FF_pivot=NULL;
90 out->A_FC=NULL;
91 out->A_CF=NULL;
92 out->rows_in_F=NULL;
93 out->rows_in_C=NULL;
94 out->mask_F=NULL;
95 out->mask_C=NULL;
96 out->x_F=NULL;
97 out->b_F=NULL;
98 out->x_C=NULL;
99 out->b_C=NULL;
100
101 if ( !(Paso_checkPtr(mis_marker) || Paso_checkPtr(out) || Paso_checkPtr(counter) ) ) {
102 /* identify independend set of rows/columns */
103 time0=Paso_timer();
104 #pragma omp parallel for private(i) schedule(static)
105 for (i=0;i<n;++i) mis_marker[i]=-1;
106 Paso_Pattern_mis(A_p->pattern,mis_marker);
107 time2=Paso_timer()-time0;
108 if (Paso_noError()) {
109 #pragma omp parallel for private(i) schedule(static)
110 for (i = 0; i < n; ++i) counter[i]=mis_marker[i];
111 out->n=n;
112 out->n_block=n_block;
113 out->n_F=Paso_Util_cumsum(n,counter);
114 out->mask_F=MEMALLOC(n,index_t);
115 out->rows_in_F=MEMALLOC(out->n_F,index_t);
116 out->inv_A_FF=MEMALLOC(n_block*n_block*out->n_F,double);
117 out->A_FF_pivot=NULL; /* later use for block size>3 */
118 if (! (Paso_checkPtr(out->mask_F) || Paso_checkPtr(out->inv_A_FF) || Paso_checkPtr(out->rows_in_F) ) ) {
119 #pragma omp parallel
120 {
121 /* creates an index for F from mask */
122 #pragma omp for private(i) schedule(static)
123 for (i = 0; i < out->n_F; ++i) out->rows_in_F[i]=-1;
124 #pragma omp for private(i) schedule(static)
125 for (i = 0; i < n; ++i) {
126 if (mis_marker[i]) {
127 out->rows_in_F[counter[i]]=i;
128 out->mask_F[i]=counter[i];
129 } else {
130 out->mask_F[i]=-1;
131 }
132 }
133 #pragma omp for private(i, where_p,iPtr,A11,A12,A13,A21,A22,A23,A31,A32,A33,D,index) schedule(static)
134 for (i = 0; i < out->n_F; i++) {
135 /* find main diagonal */
136 iPtr=A_p->pattern->ptr[out->rows_in_F[i]];
137 index=&(A_p->pattern->index[iPtr]);
138 where_p=(index_t*)bsearch(&out->rows_in_F[i],
139 index,
140 A_p->pattern->ptr[out->rows_in_F[i] + 1]-A_p->pattern->ptr[out->rows_in_F[i]],
141 sizeof(index_t),
142 Paso_comparIndex);
143 if (where_p==NULL) {
144 Paso_setError(VALUE_ERROR, "Paso_Solver_getRILU: main diagonal element missing.");
145 } else {
146 iPtr+=(index_t)(where_p-index);
147 /* get inverse of A_FF block: */
148 if (n_block==1) {
149 if (ABS(A_p->val[iPtr])>0.) {
150 out->inv_A_FF[i]=1./A_p->val[iPtr];
151 } else {
152 Paso_setError(ZERO_DIVISION_ERROR, "Paso_Solver_getRILU: Break-down in RILU decomposition: non-regular main diagonal block.");
153 }
154 } else if (n_block==2) {
155 A11=A_p->val[iPtr*4];
156 A21=A_p->val[iPtr*4+1];
157 A12=A_p->val[iPtr*4+2];
158 A22=A_p->val[iPtr*4+3];
159 D = A11*A22-A12*A21;
160 if (ABS(D) > 0 ){
161 D=1./D;
162 out->inv_A_FF[i*4]= A22*D;
163 out->inv_A_FF[i*4+1]=-A21*D;
164 out->inv_A_FF[i*4+2]=-A12*D;
165 out->inv_A_FF[i*4+3]= A11*D;
166 } else {
167 Paso_setError(ZERO_DIVISION_ERROR, "Paso_Solver_getRILU:Break-down in RILU decomposition: non-regular main diagonal block.");
168 }
169 } else if (n_block==3) {
170 A11=A_p->val[iPtr*9 ];
171 A21=A_p->val[iPtr*9+1];
172 A31=A_p->val[iPtr*9+2];
173 A12=A_p->val[iPtr*9+3];
174 A22=A_p->val[iPtr*9+4];
175 A32=A_p->val[iPtr*9+5];
176 A13=A_p->val[iPtr*9+6];
177 A23=A_p->val[iPtr*9+7];
178 A33=A_p->val[iPtr*9+8];
179 D = A11*(A22*A33-A23*A32)+ A12*(A31*A23-A21*A33)+A13*(A21*A32-A31*A22);
180 if (ABS(D) > 0 ){
181 D=1./D;
182 out->inv_A_FF[i*9 ]=(A22*A33-A23*A32)*D;
183 out->inv_A_FF[i*9+1]=(A31*A23-A21*A33)*D;
184 out->inv_A_FF[i*9+2]=(A21*A32-A31*A22)*D;
185 out->inv_A_FF[i*9+3]=(A13*A32-A12*A33)*D;
186 out->inv_A_FF[i*9+4]=(A11*A33-A31*A13)*D;
187 out->inv_A_FF[i*9+5]=(A12*A31-A11*A32)*D;
188 out->inv_A_FF[i*9+6]=(A12*A23-A13*A22)*D;
189 out->inv_A_FF[i*9+7]=(A13*A21-A11*A23)*D;
190 out->inv_A_FF[i*9+8]=(A11*A22-A12*A21)*D;
191 } else {
192 Paso_setError(ZERO_DIVISION_ERROR, "Paso_Solver_getRILU:Break-down in RILU decomposition: non-regular main diagonal block.");
193 }
194 }
195 }
196 }
197 } /* end parallel region */
198
199 if( Paso_noError()) {
200 /* if there are no nodes in the coarse level there is no more work to do */
201 out->n_C=n-out->n_F;
202 if (out->n_C>0) {
203 out->rows_in_C=MEMALLOC(out->n_C,index_t);
204 out->mask_C=MEMALLOC(n,index_t);
205 if (! (Paso_checkPtr(out->mask_C) || Paso_checkPtr(out->rows_in_C) ) ) {
206 /* creates an index for C from mask */
207 #pragma omp parallel for private(i) schedule(static)
208 for (i = 0; i < n; ++i) counter[i]=! mis_marker[i];
209 Paso_Util_cumsum(n,counter);
210 #pragma omp parallel
211 {
212 #pragma omp for private(i) schedule(static)
213 for (i = 0; i < out->n_C; ++i) out->rows_in_C[i]=-1;
214 #pragma omp for private(i) schedule(static)
215 for (i = 0; i < n; ++i) {
216 if (! mis_marker[i]) {
217 out->rows_in_C[counter[i]]=i;
218 out->mask_C[i]=counter[i];
219 } else {
220 out->mask_C[i]=-1;
221 }
222 }
223 } /* end parallel region */
224 /* get A_CF block: */
225 out->A_CF=Paso_SparseMatrix_getSubmatrix(A_p,out->n_C,out->n_F,out->rows_in_C,out->mask_F);
226 if (Paso_noError()) {
227 /* get A_FC block: */
228 out->A_FC=Paso_SparseMatrix_getSubmatrix(A_p,out->n_F,out->n_C,out->rows_in_F,out->mask_C);
229 /* get A_FF block: */
230 if (Paso_noError()) {
231 schur=Paso_SparseMatrix_getSubmatrix(A_p,out->n_C,out->n_C,out->rows_in_C,out->mask_C);
232 time0=Paso_timer()-time0;
233 if (Paso_noError()) {
234 time1=Paso_timer();
235 /* update A_CC block to get Schur complement and then apply RILU to it */
236 Paso_Solver_updateIncompleteSchurComplement(schur,out->A_CF,out->inv_A_FF,out->A_FF_pivot,out->A_FC);
237 time1=Paso_timer()-time1;
238 out->RILU_of_Schur=Paso_Solver_getRILU(schur,verbose);
239 Paso_SparseMatrix_free(schur);
240 }
241 /* allocate work arrays for RILU application */
242 if (Paso_noError()) {
243 out->x_F=MEMALLOC(n_block*out->n_F,double);
244 out->b_F=MEMALLOC(n_block*out->n_F,double);
245 out->x_C=MEMALLOC(n_block*out->n_C,double);
246 out->b_C=MEMALLOC(n_block*out->n_C,double);
247 if (! (Paso_checkPtr(out->x_F) || Paso_checkPtr(out->b_F) || Paso_checkPtr(out->x_C) || Paso_checkPtr(out->b_C) ) ) {
248 #pragma omp parallel
249 {
250 #pragma omp for private(i,k) schedule(static)
251 for (i = 0; i < out->n_F; ++i) {
252 for (k=0; k<n_block;++k) {
253 out->x_F[i*n_block+k]=0.;
254 out->b_F[i*n_block+k]=0.;
255 }
256 }
257 #pragma omp for private(i,k) schedule(static)
258 for (i = 0; i < out->n_C; ++i) {
259 for (k=0; k<n_block;++k) {
260 out->x_C[i*n_block+k]=0.;
261 out->b_C[i*n_block+k]=0.;
262 }
263 }
264 } /* end parallel region */
265 }
266 }
267 }
268 }
269 }
270 }
271 }
272 }
273 }
274 }
275 TMPMEMFREE(mis_marker);
276 TMPMEMFREE(counter);
277 if (Paso_noError()) {
278 if (verbose) {
279 printf("RILU: %d unknowns eliminated. %d left.\n",out->n_F,n-out->n_F);
280 if (out->n_C>0) {
281 printf("timing: RILU: MIS/reordering/elemination : %e/%e/%e\n",time2,time0,time1);
282 } else {
283 printf("timing: RILU: MIS: %e\n",time2);
284 }
285 }
286 return out;
287 } else {
288 Paso_Solver_RILU_free(out);
289 return NULL;
290 }
291 }
292
293 /**************************************************************/
294
295 /* apply RILU precondition b-> x
296
297 in fact it solves
298
299 [ I 0 ] [ A_FF 0 ] [ I invA_FF*A_FF ] [ x_F ] = [b_F]
300 [ A_CF*invA_FF I ] [ 0 S ] [ 0 I ] [ x_C ] = [b_C]
301
302 in the form
303
304 b->[b_F,b_C]
305 x_F=invA_FF*b_F
306 b_C=b_C-A_CF*x_F
307 x_C=RILU(b_C)
308 b_F=b_F-A_FC*x_C
309 x_F=invA_FF*b_F
310 x<-[x_F,x_C]
311
312 should be called within a parallel region
313 barrier synconization should be performed to make sure that the input vector available
314
315 */
316
317 void Paso_Solver_solveRILU(Paso_Solver_RILU * rilu, double * x, double * b) {
318 dim_t i,k;
319 dim_t n_block=rilu->n_block;
320
321 if (rilu->n_C==0) {
322 /* x=invA_FF*b */
323 Paso_Solver_applyBlockDiagonalMatrix(n_block,rilu->n_F,rilu->inv_A_FF,rilu->A_FF_pivot,x,b);
324 } else {
325 /* b->[b_F,b_C] */
326 if (n_block==1) {
327 #pragma omp parallel for private(i) schedule(static)
328 for (i=0;i<rilu->n_F;++i) rilu->b_F[i]=b[rilu->rows_in_F[i]];
329 #pragma omp parallel for private(i) schedule(static)
330 for (i=0;i<rilu->n_C;++i) rilu->b_C[i]=b[rilu->rows_in_C[i]];
331 } else {
332 #pragma omp parallel for private(i,k) schedule(static)
333 for (i=0;i<rilu->n_F;++i)
334 for (k=0;k<n_block;k++) rilu->b_F[rilu->n_block*i+k]=b[n_block*rilu->rows_in_F[i]+k];
335 #pragma omp parallel for private(i,k) schedule(static)
336 for (i=0;i<rilu->n_C;++i)
337 for (k=0;k<n_block;k++) rilu->b_C[rilu->n_block*i+k]=b[n_block*rilu->rows_in_C[i]+k];
338 }
339 /* x_F=invA_FF*b_F */
340 Paso_Solver_applyBlockDiagonalMatrix(n_block,rilu->n_F,rilu->inv_A_FF,rilu->A_FF_pivot,rilu->x_F,rilu->b_F);
341 /* b_C=b_C-A_CF*x_F */
342 Paso_SparseMatrix_MatrixVector_CSR_OFFSET0(-1.,rilu->A_CF,rilu->x_F,1.,rilu->b_C);
343 /* x_C=RILU(b_C) */
344 Paso_Solver_solveRILU(rilu->RILU_of_Schur,rilu->x_C,rilu->b_C);
345 /* b_F=b_F-A_FC*x_C */
346 Paso_SparseMatrix_MatrixVector_CSR_OFFSET0(-1.,rilu->A_FC,rilu->x_C,1.,rilu->b_F);
347 /* x_F=invA_FF*b_F */
348 Paso_Solver_applyBlockDiagonalMatrix(n_block,rilu->n_F,rilu->inv_A_FF,rilu->A_FF_pivot,rilu->x_F,rilu->b_F);
349 /* x<-[x_F,x_C] */
350 if (n_block==1) {
351 #pragma omp parallel for private(i) schedule(static)
352 for (i=0;i<rilu->n;++i) {
353 if (rilu->mask_C[i]>-1) {
354 x[i]=rilu->x_C[rilu->mask_C[i]];
355 } else {
356 x[i]=rilu->x_F[rilu->mask_F[i]];
357 }
358 }
359 } else {
360 #pragma omp parallel for private(i,k) schedule(static)
361 for (i=0;i<rilu->n;++i) {
362 if (rilu->mask_C[i]>-1) {
363 for (k=0;k<n_block;k++) x[n_block*i+k]=rilu->x_C[n_block*rilu->mask_C[i]+k];
364 } else {
365 for (k=0;k<n_block;k++) x[n_block*i+k]=rilu->x_F[n_block*rilu->mask_F[i]+k];
366 }
367 }
368 }
369 /* all done */
370 }
371 return;
372 }
373
374 /*
375 * $Log$
376 *
377 */

  ViewVC Help
Powered by ViewVC 1.1.26