/[escript]/trunk/paso/src/Smoother.c
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Annotation of /trunk/paso/src/Smoother.c

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Revision 3097 - (hide annotations)
Fri Aug 20 04:59:12 2010 UTC (8 years, 4 months ago) by gross
Original Path: trunk/paso/src/Solver_GS.c
File MIME type: text/plain
File size: 14074 byte(s)
some modifications to the GaussSeidel
1 jfenwick 1851
2     /*******************************************************
3     *
4 jfenwick 2881 * Copyright (c) 2003-2010 by University of Queensland
5 jfenwick 1851 * 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 gross 3097 /* Paso: Gauss-Seidel */
18 jfenwick 1851
19     /**************************************************************/
20    
21     /* Author: artak@uq.edu.au */
22    
23     /**************************************************************/
24    
25     #include "Paso.h"
26     #include "Solver.h"
27     #include "PasoUtil.h"
28 gross 3097 #include "BlockOps.h"
29 jfenwick 1851
30     #include <stdio.h>
31    
32 gross 3094
33 jfenwick 1851 /**************************************************************/
34    
35     /* free all memory used by GS */
36    
37     void Paso_Solver_GS_free(Paso_Solver_GS * in) {
38     if (in!=NULL) {
39 gross 3094 Paso_Solver_LocalGS_free(in->localGS);
40 jfenwick 1851 MEMFREE(in);
41     }
42     }
43 gross 3094 void Paso_Solver_LocalGS_free(Paso_Solver_LocalGS * in) {
44     if (in!=NULL) {
45     MEMFREE(in->diag);
46     MEMFREE(in->pivot);
47 gross 3097 MEMFREE(in->buffer);
48 gross 3094 MEMFREE(in);
49     }
50     }
51 jfenwick 1851 /**************************************************************/
52    
53 gross 3094 /* constructs the symmetric Gauss-Seidel preconditioner
54 jfenwick 1851
55     */
56 gross 3094 Paso_Solver_GS* Paso_Solver_getGS(Paso_SystemMatrix * A_p, dim_t sweeps, bool_t is_local, bool_t verbose)
57     {
58    
59 jfenwick 1851 /* allocations: */
60     Paso_Solver_GS* out=MEMALLOC(1,Paso_Solver_GS);
61 gross 3094 if (! Paso_checkPtr(out)) {
62     out->localGS=Paso_Solver_getLocalGS(A_p->mainBlock,sweeps,verbose);
63     out->is_local=is_local;
64 jfenwick 1851 }
65 gross 3094 if (Paso_MPIInfo_noError(A_p->mpi_info)) {
66 jfenwick 1851 return out;
67 gross 3094 } else {
68 jfenwick 1851 Paso_Solver_GS_free(out);
69     return NULL;
70     }
71     }
72 gross 3094 Paso_Solver_LocalGS* Paso_Solver_getLocalGS(Paso_SparseMatrix * A_p, dim_t sweeps, bool_t verbose) {
73    
74     dim_t n=A_p->numRows;
75     dim_t n_block=A_p->row_block_size;
76     dim_t block_size=A_p->block_size;
77    
78     double time0=Paso_timer();
79     /* allocations: */
80     Paso_Solver_LocalGS* out=MEMALLOC(1,Paso_Solver_LocalGS);
81     if (! Paso_checkPtr(out)) {
82    
83     out->diag=MEMALLOC( ((size_t) n) * ((size_t) block_size),double);
84     out->pivot=MEMALLOC( ((size_t) n) * ((size_t) n_block), index_t);
85 gross 3097 out->buffer=MEMALLOC( ((size_t) n) * ((size_t) n_block), double);
86 gross 3094 out->sweeps=sweeps;
87    
88     if ( ! ( Paso_checkPtr(out->diag) || Paso_checkPtr(out->pivot) ) ) {
89     Paso_SparseMatrix_invMain(A_p, out->diag, out->pivot );
90     }
91    
92     }
93     time0=Paso_timer()-time0;
94    
95     if (Paso_noError()) {
96     if (verbose) printf("timing: Gauss-Seidel preparation: elemination : %e\n",time0);
97     return out;
98     } else {
99     Paso_Solver_LocalGS_free(out);
100     return NULL;
101     }
102     }
103 jfenwick 1851
104 gross 3097 /*
105 jfenwick 1851
106 gross 3097 performs a few sweeps of the from
107 jfenwick 1851
108 gross 3097 S (x_{k} - x_{k-1}) = b - A x_{k-1}
109 jfenwick 1851
110 gross 3097 where x_{0}=0 and S provides some approximatioon of A.
111 jfenwick 1851
112 gross 3097 Under MPI S is build on using A_p->mainBlock only.
113     if GS is local the defect b - A x_{k-1} is calculated using A_p->mainBlock only.
114 gross 3094
115 jfenwick 1851 */
116    
117 gross 3094 void Paso_Solver_solveGS(Paso_SystemMatrix* A_p, Paso_Solver_GS * gs, double * x, const double * b)
118     {
119     register dim_t i;
120 gross 3097 const dim_t n= (A_p->mainBlock->numRows) * (A_p->mainBlock->row_block_size);
121    
122     double *b_new = gs->localGS->buffer;
123 gross 3094 dim_t sweeps=gs->localGS->sweeps;
124    
125 gross 3097 if (gs->is_local) {
126     Paso_Solver_solveLocalGS(A_p->mainBlock,gs->localGS,x,b);
127     } else {
128     #pragma omp parallel for private(i) schedule(static)
129     for (i=0;i<n;++i) x[i]=b[i];
130    
131     Paso_Solver_localGSSweep(A_p->mainBlock,gs->localGS,x);
132     while (sweeps > 0 ) {
133     #pragma omp parallel for private(i) schedule(static)
134     for (i=0;i<n;++i) b_new[i]=b[i];
135    
136     Paso_SystemMatrix_MatrixVector((-1.), A_p, x, 1., b_new); /* b_new = b - A*x */
137    
138     Paso_Solver_localGSSweep(A_p->mainBlock,gs->localGS,b_new);
139    
140     #pragma omp parallel for private(i) schedule(static)
141     for (i=0;i<n;++i) x[i]+=b_new[i];
142    
143     sweeps--;
144     }
145    
146 gross 3094 }
147 gross 3097 }
148     void Paso_Solver_solveLocalGS(Paso_SparseMatrix* A_p, Paso_Solver_LocalGS * gs, double * x, const double * b)
149     {
150     register dim_t i;
151     const dim_t n= (A_p->numRows) * (A_p->row_block_size);
152     double *b_new = gs->buffer;
153     dim_t sweeps=gs->sweeps;
154 gross 3094
155 gross 3097 #pragma omp parallel for private(i) schedule(static)
156     for (i=0;i<n;++i) x[i]=b[i];
157     Paso_Solver_localGSSweep(A_p,gs,x);
158 gross 3094
159 gross 3097 while (sweeps > 0 ) {
160 gross 3094 #pragma omp parallel for private(i) schedule(static)
161 gross 3097 for (i=0;i<n;++i) b_new[i]=b[i];
162 gross 3094
163 gross 3097 Paso_SparseMatrix_MatrixVector_CSC_OFFSET0((-1.), A_p, x, 1., b_new); /* b_new = b - A*x */
164    
165     Paso_Solver_localGSSweep(A_p,gs,b_new);
166    
167     #pragma omp parallel for private(i) schedule(static)
168     for (i=0;i<n;++i) x[i]+=b_new[i];
169    
170     sweeps--;
171 gross 3094 }
172     }
173 jfenwick 1851
174 gross 3097 void Paso_Solver_localGSSweep(Paso_SparseMatrix* A, Paso_Solver_LocalGS * gs, double * x)
175 gross 3094 {
176     #ifdef _OPENMP
177     const dim_t nt=omp_get_max_threads();
178     #else
179     const dim_t nt = 1;
180     #endif
181 gross 3097 if (nt > 1) {
182     Paso_Solver_localGSSweep_sequential(A,gs,x);
183     } else {
184     Paso_Solver_localGSSweep_colored(A,gs,x);
185 gross 3094 }
186 jfenwick 1851 }
187    
188 gross 3097 /* inplace Gauss-Seidel sweep in seqential mode: */
189 gross 3094
190 gross 3097 void Paso_Solver_localGSSweep_sequential(Paso_SparseMatrix* A_p, Paso_Solver_LocalGS * gs, double * x)
191     {
192     const dim_t n=A_p->numRows;
193     const dim_t n_block=A_p->row_block_size;
194     const double *diag = gs->diag;
195     /* const index_t* pivot = gs->pivot;
196     const dim_t block_size=A_p->block_size; use for block size >3*/
197 gross 3094
198 gross 3097 register dim_t i,k;
199     register index_t iptr_ik, mm;
200    
201     const index_t* ptr_main = Paso_SparseMatrix_borrowMainDiagonalPointer(A_p);
202    
203     /* forward substitution */
204    
205     if (n_block==1) {
206     for (i = 0; i < n; ++i) {
207     mm=ptr_main[i];
208     /* x_i=x_i-a_ik*x_k (with k<i) */
209     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
210     k=A_p->pattern->index[iptr_ik];
211     Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
212     }
213     Paso_BlockOps_MV_1(&x[i], &A_p->val[i], &x[i]);
214     }
215     } else if (n_block==2) {
216     for (i = 0; i < n; ++i) {
217     mm=ptr_main[i];
218    
219     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
220     k=A_p->pattern->index[iptr_ik];
221     Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
222     }
223     Paso_BlockOps_MV_2(&x[2*i], &A_p->val[4*i], &x[2*i]);
224     }
225     } else if (n_block==3) {
226     for (i = 0; i < n; ++i) {
227     mm=ptr_main[i];
228     /* x_i=x_i-a_ik*x_k */
229     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
230     k=A_p->pattern->index[iptr_ik];
231     Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
232     }
233     Paso_BlockOps_MV_3(&x[3*i], &A_p->val[9*i], &x[3*i]);
234     }
235    
236     } /* add block size >3 */
237    
238    
239    
240     /* backward substitution */
241    
242     if (n_block==1) {
243     for (i = n-2; i > -1; ++i) {
244     mm=ptr_main[i];
245     Paso_BlockOps_MV_1(&x[i], &A_p->val[mm], &x[i]);
246     for (iptr_ik=mm+1; iptr_ik < A_p->pattern->ptr[i+1]; ++iptr_ik) {
247     k=A_p->pattern->index[iptr_ik];
248     Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
249     }
250     Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
251     }
252     } else if (n_block==2) {
253     for (i = n-2; i > -1; ++i) {
254     mm=ptr_main[i];
255     Paso_BlockOps_MV_3(&x[2*i], &A_p->val[4*mm], &x[2*i]);
256     for (iptr_ik=mm+1; iptr_ik < A_p->pattern->ptr[i+1]; ++iptr_ik) {
257     k=A_p->pattern->index[iptr_ik];
258     Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
259     }
260     Paso_BlockOps_MV_2(&x[2*i], &diag[i*4], &x[2*i]);
261     }
262     } else if (n_block==3) {
263     for (i = n-2; i > -1; ++i) {
264    
265     mm=ptr_main[i];
266     Paso_BlockOps_MV_3(&x[3*i], &A_p->val[9*mm], &x[3*i]);
267    
268     for (iptr_ik=mm+1; iptr_ik < A_p->pattern->ptr[i+1]; ++iptr_ik) {
269     k=A_p->pattern->index[iptr_ik];
270     Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
271     }
272     Paso_BlockOps_MV_3(&x[3*i], &diag[i*9], &x[3*i]);
273     }
274    
275     } /* add block size >3 */
276    
277     return;
278     }
279 gross 3094
280 gross 3097 void Paso_Solver_localGSSweep_colored(Paso_SparseMatrix* A_p, Paso_Solver_LocalGS * gs, double * x)
281 gross 3094 {
282     const dim_t n=A_p->numRows;
283     const dim_t n_block=A_p->row_block_size;
284     const double *diag = gs->diag;
285 gross 3097 index_t* pivot = gs->pivot;
286     const dim_t block_size=A_p->block_size;
287 gross 3094
288     register dim_t i,k;
289     register index_t color,iptr_ik, mm;
290    
291     const index_t* coloring = Paso_Pattern_borrowColoringPointer(A_p->pattern);
292     const dim_t num_colors = Paso_Pattern_getNumColors(A_p->pattern);
293     const index_t* ptr_main = Paso_SparseMatrix_borrowMainDiagonalPointer(A_p);
294    
295     /* forward substitution */
296    
297     /* color = 0 */
298     if (n_block==1) {
299 gross 3097 #pragma omp parallel for schedule(static) private(i)
300 gross 3094 for (i = 0; i < n; ++i) {
301 gross 3097 if (coloring[i]== 0 ) Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
302     }
303 gross 3094 } else if (n_block==2) {
304 gross 3097 #pragma omp parallel for schedule(static) private(i)
305 gross 3094 for (i = 0; i < n; ++i) {
306 gross 3097 if (coloring[i]== 0 ) Paso_BlockOps_MV_2(&x[2*i], &diag[i*4], &x[2*i]);
307 gross 3094 }
308 gross 3097 } else if (n_block==3) {
309     #pragma omp parallel for schedule(static) private(i)
310 gross 3094 for (i = 0; i < n; ++i) {
311 gross 3097 if (coloring[i]==0) Paso_BlockOps_MV_3(&x[3*i], &diag[i*9], &x[3*i]);
312 gross 3094 }
313 gross 3097 } else {
314     #pragma omp parallel for schedule(static) private(i)
315     for (i = 0; i < n; ++i) {
316     if (coloring[i]==0) Paso_BlockOps_Solve_N(n_block, &x[n_block*i], &diag[block_size*i], &pivot[n_block*i], &x[n_block*i]);
317     }
318     }
319 gross 3094
320     for (color=1;color<num_colors;++color) {
321     if (n_block==1) {
322 gross 3097 #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
323 gross 3094 for (i = 0; i < n; ++i) {
324     if (coloring[i]==color) {
325     /* x_i=x_i-a_ik*x_k */
326     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
327     k=A_p->pattern->index[iptr_ik];
328 gross 3097 if (coloring[k]<color) Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
329 gross 3094 }
330 gross 3097 Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
331 gross 3094 }
332     }
333     } else if (n_block==2) {
334 gross 3097 #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
335 gross 3094 for (i = 0; i < n; ++i) {
336     if (coloring[i]==color) {
337     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
338     k=A_p->pattern->index[iptr_ik];
339 gross 3097 if (coloring[k]<color) Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
340 gross 3094 }
341 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &diag[4*i], &x[2*i]);
342 gross 3094 }
343    
344     }
345     } else if (n_block==3) {
346 gross 3097 #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
347 gross 3094 for (i = 0; i < n; ++i) {
348     if (coloring[i]==color) {
349     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
350     k=A_p->pattern->index[iptr_ik];
351 gross 3097 if (coloring[k]<color) Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
352 gross 3094 }
353 gross 3097 Paso_BlockOps_MV_3(&x[3*i], &diag[9*i], &x[3*i]);
354 gross 3094 }
355     }
356 gross 3097 } else {
357     #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
358     for (i = 0; i < n; ++i) {
359     if (coloring[i] == color) {
360     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
361     k=A_p->pattern->index[iptr_ik];
362     if (coloring[k]<color) Paso_BlockOps_SMV_N(n_block, &x[n_block*i], &A_p->val[block_size*iptr_ik], &x[n_block*k]);
363     }
364     Paso_BlockOps_Solve_N(n_block, &x[n_block*i], &diag[block_size*i], &pivot[n_block*i], &x[n_block*i]);
365     }
366     }
367     }
368 gross 3094 } /* end of coloring loop */
369    
370    
371     /* backward substitution */
372     for (color=(num_colors)-2 ;color>-1;--color) { /* Note: color=(num_colors)-1 is not required */
373     if (n_block==1) {
374 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
375 gross 3094 for (i = 0; i < n; ++i) {
376     if (coloring[i]==color) {
377     mm=ptr_main[i];
378 gross 3097 Paso_BlockOps_MV_1(&x[i], &A_p->val[mm], &x[i]);
379 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
380     k=A_p->pattern->index[iptr_ik];
381 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
382 gross 3094 }
383 gross 3097 Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
384 gross 3094 }
385     }
386     } else if (n_block==2) {
387 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
388 gross 3094 for (i = 0; i < n; ++i) {
389     if (coloring[i]==color) {
390     mm=ptr_main[i];
391 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &A_p->val[4*mm], &x[2*i]);
392 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
393     k=A_p->pattern->index[iptr_ik];
394 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
395 gross 3094 }
396 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &diag[4*i], &x[2*i]);
397 gross 3094 }
398     }
399     } else if (n_block==3) {
400 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
401 gross 3094 for (i = 0; i < n; ++i) {
402     if (coloring[i]==color) {
403     mm=ptr_main[i];
404 gross 3097 Paso_BlockOps_MV_3(&x[3*i], &A_p->val[9*mm], &x[3*i]);
405 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
406     k=A_p->pattern->index[iptr_ik];
407 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
408 gross 3094 }
409 gross 3097 Paso_BlockOps_MV_3(&x[3*i], &diag[9*i], &x[3*i]);
410 gross 3094 }
411     }
412 gross 3097 } else {
413     #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
414     for (i = 0; i < n; ++i) {
415     if (coloring[i]==color) {
416     mm=ptr_main[i];
417     Paso_BlockOps_MV_N( n_block, &x[n_block*i], &A_p->val[block_size*mm], &x[n_block*i] );
418     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
419     k=A_p->pattern->index[iptr_ik];
420     if (coloring[k]>color) Paso_BlockOps_SMV_N(n_block, &x[n_block*i], &A_p->val[block_size*iptr_ik], &x[n_block*k]);
421     }
422     Paso_BlockOps_Solve_N(n_block, &x[n_block*i], &diag[block_size*i], &pivot[n_block*i], &x[n_block*i]);
423     }
424     }
425     }
426 gross 3094 }
427     return;
428     }
429    
430    
431    

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