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

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Revision 3159 - (hide annotations)
Mon Sep 6 06:59:31 2010 UTC (8 years, 4 months ago) by gross
File MIME type: text/plain
File size: 14858 byte(s)
AMG is using now a simpler interface to the Smoothers.
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 gross 3120 #include "Preconditioner.h"
27 jfenwick 1851 #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 gross 3158 /* free all memory used by Smoother */
36 jfenwick 1851
37 gross 3158 void Paso_Preconditioner_Smoother_free(Paso_Preconditioner_Smoother * in) {
38 jfenwick 1851 if (in!=NULL) {
39 gross 3158 Paso_Preconditioner_LocalSmoother_free(in->localSmoother);
40 jfenwick 1851 MEMFREE(in);
41     }
42     }
43 gross 3158 void Paso_Preconditioner_LocalSmoother_free(Paso_Preconditioner_LocalSmoother * in) {
44 gross 3094 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 3158 Paso_Preconditioner_Smoother* Paso_Preconditioner_Smoother_alloc(Paso_SystemMatrix * A_p, const bool_t jacobi, const bool_t is_local, const bool_t verbose)
57 gross 3094 {
58    
59 jfenwick 1851 /* allocations: */
60 gross 3158 Paso_Preconditioner_Smoother* out=MEMALLOC(1,Paso_Preconditioner_Smoother);
61 gross 3094 if (! Paso_checkPtr(out)) {
62 gross 3158 out->localSmoother=Paso_Preconditioner_LocalSmoother_alloc(A_p->mainBlock,jacobi,verbose);
63 gross 3094 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 gross 3158 Paso_Preconditioner_Smoother_free(out);
69 jfenwick 1851 return NULL;
70     }
71     }
72 gross 3158 Paso_Preconditioner_LocalSmoother* Paso_Preconditioner_LocalSmoother_alloc(Paso_SparseMatrix * A_p, const bool_t jacobi, bool_t verbose)
73     {
74 gross 3094
75     dim_t n=A_p->numRows;
76     dim_t n_block=A_p->row_block_size;
77     dim_t block_size=A_p->block_size;
78    
79     double time0=Paso_timer();
80     /* allocations: */
81 gross 3158 Paso_Preconditioner_LocalSmoother* out=MEMALLOC(1,Paso_Preconditioner_LocalSmoother);
82 gross 3094 if (! Paso_checkPtr(out)) {
83    
84     out->diag=MEMALLOC( ((size_t) n) * ((size_t) block_size),double);
85     out->pivot=MEMALLOC( ((size_t) n) * ((size_t) n_block), index_t);
86 gross 3097 out->buffer=MEMALLOC( ((size_t) n) * ((size_t) n_block), double);
87 gross 3158 out->Jacobi=jacobi;
88 gross 3094
89     if ( ! ( Paso_checkPtr(out->diag) || Paso_checkPtr(out->pivot) ) ) {
90     Paso_SparseMatrix_invMain(A_p, out->diag, out->pivot );
91     }
92    
93     }
94     time0=Paso_timer()-time0;
95    
96     if (Paso_noError()) {
97 gross 3158 if (verbose) {
98     if (jacobi) {
99     printf("timing: Jacobi preparation: elemination : %e\n",time0);
100     } else {
101     printf("timing: Gauss-Seidel preparation: elemination : %e\n",time0);
102     }
103     }
104 gross 3094 return out;
105     } else {
106 gross 3158 Paso_Preconditioner_LocalSmoother_free(out);
107 gross 3094 return NULL;
108     }
109     }
110 jfenwick 1851
111 gross 3097 /*
112 jfenwick 1851
113 gross 3097 performs a few sweeps of the from
114 jfenwick 1851
115 gross 3097 S (x_{k} - x_{k-1}) = b - A x_{k-1}
116 jfenwick 1851
117 gross 3097 where x_{0}=0 and S provides some approximatioon of A.
118 jfenwick 1851
119 gross 3097 Under MPI S is build on using A_p->mainBlock only.
120 gross 3158 if Smoother is local the defect b - A x_{k-1} is calculated using A_p->mainBlock only.
121 gross 3094
122 jfenwick 1851 */
123    
124 gross 3159 void Paso_Preconditioner_Smoother_solve(Paso_SystemMatrix* A_p, Paso_Preconditioner_Smoother * smoother, double * x, const double * b,
125     const dim_t sweeps, const bool_t x_is_initial)
126 gross 3094 {
127 gross 3097 const dim_t n= (A_p->mainBlock->numRows) * (A_p->mainBlock->row_block_size);
128    
129 gross 3158 double *b_new = smoother->localSmoother->buffer;
130     dim_t nsweeps=sweeps;
131     if (smoother->is_local) {
132 gross 3159 Paso_Preconditioner_LocalSmoother_solve(A_p->mainBlock,smoother->localSmoother,x,b,sweeps,x_is_initial);
133 gross 3097 } else {
134 gross 3159 if (! x_is_initial) {
135     Paso_Copy(n, x, b);
136     Paso_Preconditioner_LocalSmoother_Sweep(A_p->mainBlock,smoother->localSmoother,x);
137     nsweeps--;
138     }
139     while (nsweeps > 0 ) {
140 gross 3158 Paso_Copy(n, b_new, b);
141 gross 3097 Paso_SystemMatrix_MatrixVector((-1.), A_p, x, 1., b_new); /* b_new = b - A*x */
142 gross 3159 Paso_Preconditioner_LocalSmoother_Sweep(A_p->mainBlock,smoother->localSmoother,b_new);
143 gross 3158 Paso_AXPY(n, x, 1., b_new);
144     nsweeps--;
145 gross 3097 }
146    
147 gross 3094 }
148 gross 3097 }
149 gross 3159 void Paso_Preconditioner_LocalSmoother_solve(Paso_SparseMatrix* A_p, Paso_Preconditioner_LocalSmoother * smoother, double * x, const double * b,
150     const dim_t sweeps, const bool_t x_is_initial)
151 gross 3097 {
152     const dim_t n= (A_p->numRows) * (A_p->row_block_size);
153 gross 3158 double *b_new = smoother->buffer;
154     dim_t nsweeps=sweeps;
155 gross 3094
156 gross 3159 if (! x_is_initial) {
157     Paso_Copy(n, x, b);
158     Paso_Preconditioner_LocalSmoother_Sweep(A_p,smoother,x);
159     nsweeps--;
160     }
161 gross 3105
162 gross 3159 while (nsweeps > 0 ) {
163 gross 3158 Paso_Copy(n, b_new, b);
164 gross 3097 Paso_SparseMatrix_MatrixVector_CSC_OFFSET0((-1.), A_p, x, 1., b_new); /* b_new = b - A*x */
165 gross 3158 Paso_Preconditioner_LocalSmoother_Sweep(A_p,smoother,b_new);
166 gross 3159 Paso_AXPY(n, x, 1., b_new);
167 gross 3158 nsweeps--;
168 gross 3094 }
169     }
170 jfenwick 1851
171 gross 3158 void Paso_Preconditioner_LocalSmoother_Sweep(Paso_SparseMatrix* A, Paso_Preconditioner_LocalSmoother * smoother, double * x)
172 gross 3094 {
173     #ifdef _OPENMP
174     const dim_t nt=omp_get_max_threads();
175     #else
176     const dim_t nt = 1;
177     #endif
178 gross 3158 if (smoother->Jacobi) {
179     Paso_BlockOps_allMV(A->row_block_size,A->numRows,smoother->diag,smoother->pivot,x);
180 gross 3097 } else {
181 gross 3158 if (nt < 2) {
182     Paso_Preconditioner_LocalSmoother_Sweep_sequential(A,smoother,x);
183     } else {
184     Paso_Preconditioner_LocalSmoother_Sweep_colored(A,smoother,x);
185     }
186 gross 3094 }
187 jfenwick 1851 }
188    
189 gross 3097 /* inplace Gauss-Seidel sweep in seqential mode: */
190 gross 3094
191 gross 3158 void Paso_Preconditioner_LocalSmoother_Sweep_sequential(Paso_SparseMatrix* A_p, Paso_Preconditioner_LocalSmoother * smoother, double * x)
192 gross 3097 {
193     const dim_t n=A_p->numRows;
194     const dim_t n_block=A_p->row_block_size;
195 gross 3158 const double *diag = smoother->diag;
196     /* const index_t* pivot = smoother->pivot;
197 gross 3097 const dim_t block_size=A_p->block_size; use for block size >3*/
198 gross 3094
199 gross 3097 register dim_t i,k;
200     register index_t iptr_ik, mm;
201    
202     const index_t* ptr_main = Paso_SparseMatrix_borrowMainDiagonalPointer(A_p);
203     /* forward substitution */
204    
205     if (n_block==1) {
206 gross 3098 Paso_BlockOps_MV_1(&x[0], &diag[0], &x[0]);
207     for (i = 1; i < n; ++i) {
208 gross 3097 mm=ptr_main[i];
209 gross 3105 /* x_i=x_i-a_ik*x_k (with k<i) */
210 gross 3097 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
211 gross 3098 k=A_p->pattern->index[iptr_ik];
212 gross 3097 Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
213     }
214 gross 3098 Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
215 gross 3097 }
216     } else if (n_block==2) {
217 gross 3098 Paso_BlockOps_MV_2(&x[0], &diag[0], &x[0]);
218     for (i = 1; i < n; ++i) {
219 gross 3097 mm=ptr_main[i];
220     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
221     k=A_p->pattern->index[iptr_ik];
222     Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
223     }
224 gross 3098 Paso_BlockOps_MV_2(&x[2*i], &diag[4*i], &x[2*i]);
225 gross 3097 }
226     } else if (n_block==3) {
227 gross 3098 Paso_BlockOps_MV_3(&x[0], &diag[0], &x[0]);
228     for (i = 1; i < n; ++i) {
229 gross 3097 mm=ptr_main[i];
230     /* x_i=x_i-a_ik*x_k */
231     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<mm; ++iptr_ik) {
232     k=A_p->pattern->index[iptr_ik];
233     Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
234     }
235 gross 3098 Paso_BlockOps_MV_3(&x[3*i], &diag[9*i], &x[3*i]);
236 gross 3097 }
237     } /* add block size >3 */
238 gross 3105
239 gross 3097 /* backward substitution */
240    
241     if (n_block==1) {
242 gross 3105 for (i = n-2; i > -1; --i) {
243 gross 3098 mm=ptr_main[i];
244     Paso_BlockOps_MV_1(&x[i], &A_p->val[mm], &x[i]);
245     for (iptr_ik=mm+1; iptr_ik < A_p->pattern->ptr[i+1]; ++iptr_ik) {
246     k=A_p->pattern->index[iptr_ik];
247     Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
248     }
249     Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
250 gross 3097 }
251 gross 3098
252 gross 3097 } else if (n_block==2) {
253 gross 3105 for (i = n-2; i > -1; --i) {
254 gross 3098 mm=ptr_main[i];
255     Paso_BlockOps_MV_2(&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 gross 3097 }
262     } else if (n_block==3) {
263 gross 3105 for (i = n-2; i > -1; --i) {
264 gross 3098 mm=ptr_main[i];
265     Paso_BlockOps_MV_3(&x[3*i], &A_p->val[9*mm], &x[3*i]);
266 gross 3097
267 gross 3098 for (iptr_ik=mm+1; iptr_ik < A_p->pattern->ptr[i+1]; ++iptr_ik) {
268     k=A_p->pattern->index[iptr_ik];
269     Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
270     }
271     Paso_BlockOps_MV_3(&x[3*i], &diag[i*9], &x[3*i]);
272 gross 3097 }
273    
274     } /* add block size >3 */
275    
276     return;
277     }
278 gross 3094
279 gross 3158 void Paso_Preconditioner_LocalSmoother_Sweep_colored(Paso_SparseMatrix* A_p, Paso_Preconditioner_LocalSmoother * smoother, double * x)
280 gross 3094 {
281     const dim_t n=A_p->numRows;
282     const dim_t n_block=A_p->row_block_size;
283 gross 3158 const double *diag = smoother->diag;
284     index_t* pivot = smoother->pivot;
285 gross 3097 const dim_t block_size=A_p->block_size;
286 gross 3094
287     register dim_t i,k;
288     register index_t color,iptr_ik, mm;
289    
290     const index_t* coloring = Paso_Pattern_borrowColoringPointer(A_p->pattern);
291     const dim_t num_colors = Paso_Pattern_getNumColors(A_p->pattern);
292     const index_t* ptr_main = Paso_SparseMatrix_borrowMainDiagonalPointer(A_p);
293    
294     /* forward substitution */
295 gross 3105
296 gross 3094
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 gross 3105
322 gross 3094 if (n_block==1) {
323 gross 3097 #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
324 gross 3094 for (i = 0; i < n; ++i) {
325     if (coloring[i]==color) {
326     /* x_i=x_i-a_ik*x_k */
327     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
328 gross 3105 k=A_p->pattern->index[iptr_ik];
329 gross 3097 if (coloring[k]<color) Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
330 gross 3094 }
331 gross 3097 Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
332 gross 3094 }
333     }
334     } else if (n_block==2) {
335 gross 3097 #pragma omp parallel for schedule(static) private(i,iptr_ik,k)
336 gross 3094 for (i = 0; i < n; ++i) {
337     if (coloring[i]==color) {
338     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
339     k=A_p->pattern->index[iptr_ik];
340 gross 3097 if (coloring[k]<color) Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
341 gross 3094 }
342 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &diag[4*i], &x[2*i]);
343 gross 3094 }
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     /* backward substitution */
371     for (color=(num_colors)-2 ;color>-1;--color) { /* Note: color=(num_colors)-1 is not required */
372     if (n_block==1) {
373 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
374 gross 3094 for (i = 0; i < n; ++i) {
375     if (coloring[i]==color) {
376     mm=ptr_main[i];
377 gross 3097 Paso_BlockOps_MV_1(&x[i], &A_p->val[mm], &x[i]);
378 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
379     k=A_p->pattern->index[iptr_ik];
380 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_1(&x[i], &A_p->val[iptr_ik], &x[k]);
381 gross 3094 }
382 gross 3097 Paso_BlockOps_MV_1(&x[i], &diag[i], &x[i]);
383 gross 3094 }
384     }
385     } else if (n_block==2) {
386 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
387 gross 3094 for (i = 0; i < n; ++i) {
388     if (coloring[i]==color) {
389     mm=ptr_main[i];
390 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &A_p->val[4*mm], &x[2*i]);
391 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
392     k=A_p->pattern->index[iptr_ik];
393 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_2(&x[2*i], &A_p->val[4*iptr_ik], &x[2*k]);
394 gross 3094 }
395 gross 3097 Paso_BlockOps_MV_2(&x[2*i], &diag[4*i], &x[2*i]);
396 gross 3094 }
397     }
398     } else if (n_block==3) {
399 gross 3097 #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
400 gross 3094 for (i = 0; i < n; ++i) {
401     if (coloring[i]==color) {
402     mm=ptr_main[i];
403 gross 3097 Paso_BlockOps_MV_3(&x[3*i], &A_p->val[9*mm], &x[3*i]);
404 gross 3094 for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
405     k=A_p->pattern->index[iptr_ik];
406 gross 3097 if (coloring[k]>color) Paso_BlockOps_SMV_3(&x[3*i], &A_p->val[9*iptr_ik], &x[3*k]);
407 gross 3094 }
408 gross 3097 Paso_BlockOps_MV_3(&x[3*i], &diag[9*i], &x[3*i]);
409 gross 3094 }
410     }
411 gross 3097 } else {
412     #pragma omp parallel for schedule(static) private(mm, i,iptr_ik,k)
413     for (i = 0; i < n; ++i) {
414     if (coloring[i]==color) {
415     mm=ptr_main[i];
416     Paso_BlockOps_MV_N( n_block, &x[n_block*i], &A_p->val[block_size*mm], &x[n_block*i] );
417     for (iptr_ik=A_p->pattern->ptr[i];iptr_ik<A_p->pattern->ptr[i+1]; ++iptr_ik) {
418     k=A_p->pattern->index[iptr_ik];
419     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]);
420     }
421     Paso_BlockOps_Solve_N(n_block, &x[n_block*i], &diag[block_size*i], &pivot[n_block*i], &x[n_block*i]);
422     }
423     }
424     }
425 gross 3094 }
426     return;
427 gross 3125 }

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