File: test_pbrfs.cc

package info (click to toggle)
lapackpp 2024.10.26-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 6,500 kB
  • sloc: cpp: 80,181; ansic: 27,660; python: 4,838; xml: 182; perl: 99; makefile: 53; sh: 23
file content (193 lines) | stat: -rw-r--r-- 6,437 bytes parent folder | download
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
// Copyright (c) 2017-2023, University of Tennessee. All rights reserved.
// SPDX-License-Identifier: BSD-3-Clause
// This program is free software: you can redistribute it and/or modify it under
// the terms of the BSD 3-Clause license. See the accompanying LICENSE file.

#include "test.hh"
#include "lapack.hh"
#include "lapack/flops.hh"
#include "print_matrix.hh"
#include "error.hh"
#include "lapacke_wrappers.hh"
#include "cblas_wrappers.hh"

#include <vector>

// -----------------------------------------------------------------------------
template< typename scalar_t >
void test_pbrfs_work( Params& params, bool run )
{
    using real_t = blas::real_type< scalar_t >;

    // get & mark input values
    lapack::Uplo uplo = params.uplo();
    int64_t n = params.dim.n();
    int64_t kd = params.kd();
    int64_t nrhs = params.nrhs();
    int64_t align = params.align();
    int64_t verbose = params.verbose();

    real_t eps = std::numeric_limits< real_t >::epsilon();
    real_t tol = params.tol() * eps;

    // mark non-standard output values
    params.ref_time();
    //params.ref_gflops();
    //params.gflops();

    if (! run)
        return;

    // ---------- setup
    int64_t ldab = roundup( kd+1, align );
    int64_t ldafb = ldab;
    int64_t ldb = roundup( blas::max( 1, n ), align );
    int64_t ldx = ldb;
    size_t size_AB = (size_t) ldab * n;
    size_t size_AFB = size_AB;
    size_t size_B = (size_t) ldb * nrhs;
    size_t size_X = size_B;
    size_t size_ferr = (size_t) (nrhs);
    size_t size_berr = (size_t) (nrhs);

    std::vector< scalar_t > AB( size_AB );
    std::vector< scalar_t > AFB( size_AFB );
    std::vector< scalar_t > B( size_B );
    std::vector< scalar_t > X_tst( size_X );
    std::vector< scalar_t > X_ref( size_X );
    std::vector< real_t > ferr_tst( size_ferr );
    std::vector< real_t > ferr_ref( size_ferr );
    std::vector< real_t > berr_tst( size_berr );
    std::vector< real_t > berr_ref( size_berr );

    int64_t idist = 1;
    int64_t iseed[4] = { 0, 1, 2, 3 };
    lapack::larnv( idist, iseed, AB.size(), &AB[0] );
    int64_t iseed_B[4];
    std::copy( iseed, iseed+4, iseed_B );
    lapack::larnv( idist, iseed, B.size(), &B[0] );
    X_tst = B;

    // diagonally dominant -> positive definite
    if (uplo == lapack::Uplo::Upper) {
        for (int64_t j = 0; j < n; ++j) {
            AB[ kd + j*ldab ] += n;
        }
    }
    else { // lower
        for (int64_t j = 0; j < n; ++j) {
            AB[ j*ldab ] += n;
        }
    }

    AFB = AB;

    // Factor
    int64_t info = lapack::pbtrf( uplo, n, kd, &AFB[0], ldafb );
    if (info != 0) {
        fprintf( stderr, "lapack::pbtrf returned error %lld\n", llong( info ) );
    }

    // Solve in X_tst
    info = lapack::pbtrs ( uplo, n, kd, nrhs, &AFB[0], ldab, &X_tst[0], ldx );
    if (info != 0) {
        fprintf( stderr, "lapack::pbtrs returned error %lld\n", llong( info ) );
    }
    X_ref = X_tst;

    if (verbose >= 2) {
        printf( "A_factor = " ); print_matrix( kd+1, n, &AFB[0], ldafb );
        printf( "X = " ); print_matrix( n, nrhs, &X_tst[0], ldx );
    }


    // ---------- run test
    testsweeper::flush_cache( params.cache() );
    double time = testsweeper::get_wtime();
    // Refine solution in X_tst, using original AB and B, factored AFB.
    int64_t info_tst = lapack::pbrfs(
        uplo, n, kd, nrhs, &AB[0], ldab, &AFB[0], ldafb,
        &B[0], ldb, &X_tst[0], ldx, &ferr_tst[0], &berr_tst[0] );
    time = testsweeper::get_wtime() - time;
    if (info_tst != 0) {
        fprintf( stderr, "lapack::pbrfs returned error %lld\n", llong( info_tst ) );
    }

    params.time() = time;
    //double gflop = lapack::Gflop< scalar_t >::pbrfs( n, kd, nrhs );
    //params.gflops() = gflop / time;

    if (verbose >= 2) {
        printf( "Xrfs = " ); print_matrix( n, nrhs, &X_tst[0], ldx );
        printf( "ferr = " ); print_vector( n, &ferr_tst[0], 1 );
        printf( "berr = " ); print_vector( n, &berr_tst[0], 1 );
    }

    if (params.check() == 'y') {
        // ---------- check error
        // Relative backwards error = ||b - Ax|| / (n * ||A|| * ||x||).
        // No hbmm, so loop over RHS.
        for (int64_t j = 0; j < nrhs; ++j) {
            // B_ref -= A * B_tst
            cblas_hbmv( CblasColMajor, cblas_uplo_const(uplo), n, kd,
                        -1.0, &AB[0], ldab,
                              &X_tst[ j*ldx ], 1,
                         1.0, &B[ j*ldb ], 1 );
        }
        if (verbose >= 2) {
            printf( "R = " ); print_matrix( n, nrhs, &B[0], ldb );
        }

        real_t error = lapack::lange( lapack::Norm::One, n, nrhs, &B[0], ldb );
        real_t Xnorm = lapack::lange( lapack::Norm::One, n, nrhs, &X_tst[0], ldx );
        real_t Anorm = lapack::lanhb( lapack::Norm::One, uplo, n, kd, &AB[0], ldab );
        error /= (n * Anorm * Xnorm);
        params.error() = error;
        params.okay() = (error < tol);

        // Reset B for ref using saved seed.
        lapack::larnv( idist, iseed_B, B.size(), &B[0] );
    }

    if (params.ref() == 'y') {
        // ---------- run reference
        testsweeper::flush_cache( params.cache() );
        time = testsweeper::get_wtime();
        int64_t info_ref = LAPACKE_pbrfs(
            to_char( uplo ), n, kd, nrhs, &AB[0], ldab, &AFB[0], ldafb,
            &B[0], ldb, &X_ref[0], ldx, &ferr_ref[0], &berr_ref[0] );
        time = testsweeper::get_wtime() - time;
        if (info_ref != 0) {
            fprintf( stderr, "LAPACKE_pbrfs returned error %lld\n", llong( info_ref ) );
        }

        params.ref_time() = time;
        //params.ref_gflops() = gflop / time;
    }
}

// -----------------------------------------------------------------------------
void test_pbrfs( Params& params, bool run )
{
    switch (params.datatype()) {
        case testsweeper::DataType::Single:
            test_pbrfs_work< float >( params, run );
            break;

        case testsweeper::DataType::Double:
            test_pbrfs_work< double >( params, run );
            break;

        case testsweeper::DataType::SingleComplex:
            test_pbrfs_work< std::complex<float> >( params, run );
            break;

        case testsweeper::DataType::DoubleComplex:
            test_pbrfs_work< std::complex<double> >( params, run );
            break;

        default:
            throw std::runtime_error( "unknown datatype" );
            break;
    }
}