1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
/*
-- MAGMA (version 2.9.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
@date January 2025
@author Hartwig Anzt
@generated from sparse/src/zpcgs_merge.cpp, normal z -> s, Wed Jan 22 14:42:40 2025
*/
#include "magmasparse_internal.h"
#define RTOLERANCE lapackf77_slamch( "E" )
#define ATOLERANCE lapackf77_slamch( "E" )
/**
Purpose
-------
Solves a system of linear equations
A * X = B
where A is a real matrix A.
This is a GPU implementation of the preconditioned Conjugate
Gradient Squared (CGS) method.
Arguments
---------
@param[in]
A magma_s_matrix
input matrix A
@param[in]
b magma_s_matrix
RHS b
@param[in,out]
x magma_s_matrix*
solution approximation
@param[in,out]
solver_par magma_s_solver_par*
solver parameters
@param[in]
precond_par magma_s_preconditioner*
preconditioner
@param[in]
queue magma_queue_t
Queue to execute in.
@ingroup magmasparse_sgesv
********************************************************************/
extern "C" magma_int_t
magma_spcgs_merge(
magma_s_matrix A, magma_s_matrix b, magma_s_matrix *x,
magma_s_solver_par *solver_par,
magma_s_preconditioner *precond_par,
magma_queue_t queue )
{
magma_int_t info = MAGMA_NOTCONVERGED;
// prepare solver feedback
solver_par->solver = Magma_PCGS;
solver_par->numiter = 0;
solver_par->spmv_count = 0;
// local variables
float c_zero = MAGMA_S_ZERO, c_one = MAGMA_S_ONE;
// solver variables
float nom0, r0, res, nomb;
float rho, rho_l = c_one, alpha, beta;
magma_int_t dofs = A.num_rows* b.num_cols;
// GPU workspace
magma_s_matrix r={Magma_CSR}, rt={Magma_CSR}, r_tld={Magma_CSR},
p={Magma_CSR}, q={Magma_CSR}, u={Magma_CSR}, v={Magma_CSR}, t={Magma_CSR},
p_hat={Magma_CSR}, q_hat={Magma_CSR}, u_hat={Magma_CSR}, v_hat={Magma_CSR};
CHECK( magma_svinit( &r, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &rt,Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &r_tld,Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &p, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &p_hat, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &q, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &q_hat, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &u, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &u_hat, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &v, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &v_hat, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
CHECK( magma_svinit( &t, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
// solver setup
CHECK( magma_sresidualvec( A, b, *x, &r, &nom0, queue));
magma_scopy( dofs, r.dval, 1, r_tld.dval, 1, queue );
solver_par->init_res = nom0;
nomb = magma_snrm2( dofs, b.dval, 1, queue );
if ( nomb == 0.0 ){
nomb=1.0;
}
if ( (r0 = nomb * solver_par->rtol) < ATOLERANCE ){
r0 = ATOLERANCE;
}
solver_par->final_res = solver_par->init_res;
solver_par->iter_res = solver_par->init_res;
if ( solver_par->verbose > 0 ) {
solver_par->res_vec[0] = (real_Double_t)nom0;
solver_par->timing[0] = 0.0;
}
if ( nom0 < r0 ) {
info = MAGMA_SUCCESS;
goto cleanup;
}
//Chronometry
real_Double_t tempo1, tempo2;
tempo1 = magma_sync_wtime( queue );
solver_par->numiter = 0;
solver_par->spmv_count = 0;
// start iteration
do
{
solver_par->numiter++;
rho = magma_sdot( dofs, r_tld.dval, 1, r.dval, 1, queue );
// rho = < r,r_tld>
if ( MAGMA_S_ABS(rho) == 0.0 ) {
goto cleanup;
}
if ( solver_par->numiter > 1 ) { // direction vectors
beta = rho / rho_l;
magma_scgs_1(
r.num_rows,
r.num_cols,
beta,
r.dval,
q.dval,
u.dval,
p.dval,
queue );
//u = r + beta*q;
//p = u + beta*( q + beta*p );
}
else{
magma_scgs_2(
r.num_rows,
r.num_cols,
r.dval,
u.dval,
p.dval,
queue );
// u = r
// p = r
}
// preconditioner
CHECK( magma_s_applyprecond_left( MagmaNoTrans, A, p, &rt, precond_par, queue ));
CHECK( magma_s_applyprecond_right( MagmaNoTrans, A, rt, &p_hat, precond_par, queue ));
CHECK( magma_s_spmv( c_one, A, p_hat, c_zero, v_hat, queue )); // v = A p
solver_par->spmv_count++;
alpha = rho / magma_sdot( dofs, r_tld.dval, 1, v_hat.dval, 1, queue );
magma_scgs_3(
r.num_rows,
r.num_cols,
alpha,
v_hat.dval,
u.dval,
q.dval,
t.dval,
queue );
// q = u - alpha v_hat
// t = u + q
// preconditioner
CHECK( magma_s_applyprecond_left( MagmaNoTrans, A, t, &rt, precond_par, queue ));
CHECK( magma_s_applyprecond_right( MagmaNoTrans, A, rt, &u_hat, precond_par, queue ));
CHECK( magma_s_spmv( c_one, A, u_hat, c_zero, t, queue )); // t = A u_hat
solver_par->spmv_count++;
magma_scgs_4(
r.num_rows,
r.num_cols,
alpha,
u_hat.dval,
t.dval,
x->dval,
r.dval,
queue );
// r = r -alpha*A u_hat
// x = x + alpha u_hat
res = magma_snrm2( dofs, r.dval, 1, queue );
if ( solver_par->verbose > 0 ) {
tempo2 = magma_sync_wtime( queue );
if ( (solver_par->numiter)%solver_par->verbose == 0 ) {
solver_par->res_vec[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) res;
solver_par->timing[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) tempo2-tempo1;
}
}
if ( res/nomb <= solver_par->rtol || res <= solver_par->atol ){
break;
}
rho_l = rho;
}
while ( solver_par->numiter+1 <= solver_par->maxiter );
tempo2 = magma_sync_wtime( queue );
solver_par->runtime = (real_Double_t) tempo2-tempo1;
float residual;
CHECK( magma_sresidualvec( A, b, *x, &r, &residual, queue));
solver_par->iter_res = res;
solver_par->final_res = residual;
if ( solver_par->numiter < solver_par->maxiter ) {
info = MAGMA_SUCCESS;
} else if ( solver_par->init_res > solver_par->final_res ) {
if ( solver_par->verbose > 0 ) {
if ( (solver_par->numiter)%solver_par->verbose == 0 ) {
solver_par->res_vec[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) res;
solver_par->timing[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) tempo2-tempo1;
}
}
info = MAGMA_SLOW_CONVERGENCE;
if( solver_par->iter_res < solver_par->rtol*nomb ||
solver_par->iter_res < solver_par->atol ) {
info = MAGMA_SUCCESS;
}
}
else {
if ( solver_par->verbose > 0 ) {
if ( (solver_par->numiter)%solver_par->verbose == 0 ) {
solver_par->res_vec[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) res;
solver_par->timing[(solver_par->numiter)/solver_par->verbose]
= (real_Double_t) tempo2-tempo1;
}
}
info = MAGMA_DIVERGENCE;
}
cleanup:
magma_smfree(&r, queue );
magma_smfree(&rt, queue );
magma_smfree(&r_tld, queue );
magma_smfree(&p, queue );
magma_smfree(&q, queue );
magma_smfree(&u, queue );
magma_smfree(&v, queue );
magma_smfree(&t, queue );
magma_smfree(&p_hat, queue );
magma_smfree(&q_hat, queue );
magma_smfree(&u_hat, queue );
magma_smfree(&v_hat, queue );
solver_par->info = info;
return info;
} /* magma_spcgs_merge */
|
