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
     273
     274
     275
     276
     277
     278
     279
     280
     281
     282
     283
     284
     285
     286
     287
     288
     289
     290
     291
     292
     293
     294
     295
     296
     297
     298
     299
     300
     301
     302
     303
     304
     305
     306
     307
     308
     309
     310
     311
     312
     313
     314
     315
     316
     317
     318
     319
     320
     321
     322
     323
     324
     325
     326
     327
     328
     329
     330
     331
     332
     333
     334
     335
     336
     337
     338
     339
     340
     341
     342
     343
     344
     345
     346
     347
     348
     349
     350
     351
     352
     353
     354
     355
     356
     357
     358
     359
     360
     361
     362
     363
     364
     365
     366
     367
     368
     369
     370
     371
     372
     373
     374
     375
     376
     377
     378
     379
     380
     381
     382
     383
     384
     385
     386
     387
     388
     389
     390
     391
     392
     393
/*
 *   Copyright (c) 2012, Michael Lehn, Klaus Pototzky
 *
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *   1) Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *   2) Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in
 *      the documentation and/or other materials provided with the
 *      distribution.
 *   3) Neither the name of the FLENS development group nor the names of
 *      its contributors may be used to endorse or promote products derived
 *      from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* Baesed on
 *
      SUBROUTINE DGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
      SUBROUTINE ZGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )

      SUBROUTINE DTRTRI( UPLO, DIAG, N, A, LDA, INFO )
      SUBROUTINE ZTRTRI( UPLO, DIAG, N, A, LDA, INFO )
 *
 *  -- LAPACK routine (version 3.2) --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *     November 2006
 */

#ifndef FLENS_LAPACK_GE_TRI_TCC
#define FLENS_LAPACK_GE_TRI_TCC 1

#include <algorithm>
#include <flens/blas/blas.h>
#include <flens/lapack/lapack.h>

namespace flens { namespace lapack {

//== generic lapack implementation =============================================

namespace generic {

//-- (ge)tri [real variant] ----------------------------------------------------

template <typename MA, typename VP, typename VWORK>
typename GeMatrix<MA>::IndexType
tri_impl(GeMatrix<MA>            &A,
         const DenseVector<VP>   &piv,
         DenseVector<VWORK>      &work)
{
    using std::max;

    typedef typename GeMatrix<MA>::ElementType ElementType;
    typedef typename GeMatrix<MA>::IndexType   IndexType;

    const ElementType Zero(0), One(1);
    const IndexType n = A.numRows();
    const Underscore<IndexType> _;

    IndexType info = 0;
    IndexType nb = ilaenv<ElementType>(1"GETRI""", n);

    const IndexType lWorkOpt = n*nb;

    if (work.length()==0) {
        work.resize(max(lWorkOpt, IndexType(1)));
    }
    work(1) = lWorkOpt;

//
//  Quick return if possible
//
    if (n==0) {
        return info;
    }
//
//  Form inv(U).  If INFO > 0 from DTRTRI, then U is singular,
//  and the inverse is not computed.
//
    info = tri(A.upper());
    if (info>0) {
        return info;
    }

    IndexType nbMin = 2;
    const IndexType lWork  = work.length();;
    const IndexType ldWork = n;

    IndexType iws;

    if (nb>1 && nb<n) {
        iws = max(ldWork*nb, IndexType(1));
        if (lWork<iws) {
            nb = lWork / ldWork;
            nbMin = max(2, ilaenv<ElementType>(2"GETRI""", n));
        }
    } else {
        iws = n;
    }

    GeMatrixView<ElementType> Work(n, nb, work);
//
//  Solve the equation inv(A)*L = inv(U) for inv(A).
//
    if (nb<nbMin || nb>=n) {
//
//      Use unblocked code.
//
        for (IndexType j=n; j>=1; --j) {
//
//          Copy current column of L to WORK and replace with zeros.
//
            work(_(j+1,n)) = A(_(j+1,n),j);
            A(_(j+1,n),j)  = Zero;;
//
//          Compute current column of inv(A).
//
            if (j<n) {
                blas::mv(NoTrans, -One,
                         A(_,_(j+1,n)), work(_(j+1,n)),
                         One,
                         A(_,j));
            }
        }
    } else {
//
//      Use blocked code.
//
        const IndexType nn = ((n-1)/nb)*nb1;
        for (IndexType j=nn; j>=1; j-=nb) {
            const IndexType jb = min(nb, n-j+1);
//
//          Copy current block column of L to WORK and replace with
//          zeros.
//
            for (IndexType jj=j, JJ=1; jj<=j+jb-1; ++jj, ++JJ) {
                Work(_(jj+1,n),JJ) = A(_(jj+1,n),jj);
                A(_(jj+1,n),jj)    = Zero;
            }
//
//          Compute current block column of inv(A).
//
            if (j+jb<=n) {
                blas::mm(NoTrans, NoTrans,
                         -One,
                         A(_,_(j+jb,n)),
                         Work(_(j+jb,n),_(1,jb)),
                         One,
                         A(_,_(j,j+jb-1)));
            }
            blas::sm(Right, NoTrans,
                     One, Work(_(j,j+jb-1),_(1,jb)).lowerUnit(),
                     A(_,_(j,j+jb-1)));
        }
    }
//
//  Apply column interchanges.
//
    for (IndexType j=n-1; j>=1; --j) {
        const IndexType jp = piv(j);
        if (jp!=j) {
            blas::swap(A(_,j), A(_,jp));
        }
    }

    work(1) = iws;
    return info;
}

// namespace generic

//== interface for native lapack ===============================================

#ifdef USE_CXXLAPACK

namespace external {

//-- (ge)tri [real and complex variant] ----------------------------------------

template <typename MA, typename VP, typename VWORK>
typename GeMatrix<MA>::IndexType
tri_impl(GeMatrix<MA>             &A,
         const DenseVector<VP>    &piv,
         DenseVector<VWORK>       &work)
{
    typedef typename GeMatrix<MA>::ElementType  ElementType;
    typedef typename GeMatrix<MA>::IndexType    IndexType;

    IndexType info;

    if (work.length()==0) {
        ElementType  WORK;
        IndexType    LWORK = -1;

        info = cxxlapack::getri<IndexType>(A.numRows(),
                                           A.data(),
                                           A.leadingDimension(),
                                           piv.data(),
                                           &WORK,
                                           LWORK);
        work.resize(IndexType(cxxblas::real(WORK)));
    }

    info = cxxlapack::getri<IndexType>(A.numRows(),
                                       A.data(),
                                       A.leadingDimension(),
                                       piv.data(),
                                       work.data(),
                                       work.length());
    ASSERT(info>=0);
    return info;
}

// namespace external

#endif // USE_CXXLAPACK

//== public interface ==========================================================

//-- (ge)tri [real variant] ----------------------------------------------------

template <typename MA, typename VPIV, typename VWORK>
typename RestrictTo<IsRealGeMatrix<MA>::value
                 && IsIntegerDenseVector<VPIV>::value
                 && IsRealDenseVector<VWORK>::value,
         typename RemoveRef<MA>::Type::IndexType>::Type
tri(MA          &&A,
    const VPIV  &piv,
    VWORK       &&work)
{
    using std::max;

//
//  Remove references from rvalue types
//
    typedef typename RemoveRef<MA>::Type    MatrixA;
    typedef typename MatrixA::IndexType     IndexType;
    typedef typename RemoveRef<VPIV>::Type  VectorPiv;
    typedef typename RemoveRef<VWORK>::Type VectorWork;

//
//  Test the input parameters
//
#   ifndef NDEBUG
    ASSERT(A.firstRow()==1);
    ASSERT(A.firstCol()==1);
    ASSERT(A.numRows()==A.numCols());

    const IndexType n = A.numRows();

    ASSERT(piv.firstIndex()==1);
    ASSERT(piv.length()==n);

    const bool lQuery = (work.length()==0);
    ASSERT(lQuery || work.length()>=max(IndexType(1),n));
#   endif

//
//  Make copies of output arguments
//
#   ifdef CHECK_CXXLAPACK
    typename MatrixA::NoView        A_org    = A;
    typename VectorWork::NoView     work_org = work;
#   endif

//
//  Call implementation
//
    const IndexType info = LAPACK_SELECT::tri_impl(A, piv, work);

//
//  Compare results
//
#   ifdef CHECK_CXXLAPACK
    typename MatrixA::NoView        A_generic    = A;
    typename VectorWork::NoView     work_generic = work;

    A    = A_org;
    work = work_org;

    const IndexType _info = external::tri_impl(A, piv, work);

    bool failed = false;
    if (! isIdentical(A_generic, A, "A_generic""A")) {
        std::cerr << "CXXLAPACK: A_generic = " << A_generic << std::endl;
        std::cerr << "F77LAPACK: A = " << A << std::endl;
        failed = true;
    }

    if (! isIdentical(work_generic, work, "work_generic""work")) {
        std::cerr << "CXXLAPACK: work_generic = " << work_generic << std::endl;
        std::cerr << "F77LAPACK: work = " << work << std::endl;
        failed = true;
    }

    if (! isIdentical(info, _info, " info""_info")) {
        std::cerr << "CXXLAPACK:  info = " << info << std::endl;
        std::cerr << "F77LAPACK: _info = " << _info << std::endl;
        failed = true;
    }

    if (failed) {
        ASSERT(0);
    } else {
        // std::cerr << "passed: (ge)tri.tcc" << std::endl;
    }
#   endif

    return info;
}

//-- (ge)tri [complex variant] -------------------------------------------------

#ifdef USE_CXXLAPACK

template <typename MA, typename VPIV, typename VWORK>
typename RestrictTo<IsComplexGeMatrix<MA>::value
                 && IsIntegerDenseVector<VPIV>::value
                 && IsComplexDenseVector<VWORK>::value,
         typename RemoveRef<MA>::Type::IndexType>::Type
tri(MA &&A, const VPIV &piv, VWORK &&work)
{
    using std::max;

//
//  Remove references from rvalue types
//
    typedef typename RemoveRef<MA>::Type    MatrixA;
    typedef typename MatrixA::IndexType     IndexType;
    typedef typename RemoveRef<VPIV>::Type  VectorPiv;
    typedef typename RemoveRef<VWORK>::Type VectorWork;

//
//  Test the input parameters
//
#   ifndef NDEBUG
    ASSERT(A.firstRow()==1);
    ASSERT(A.firstCol()==1);
    ASSERT(A.numRows()==A.numCols());

    const IndexType n = A.numRows();

    ASSERT(piv.firstIndex()==1);
    ASSERT(piv.length()==n);

    const bool lQuery = (work.length()==0);
    ASSERT(lQuery || work.length()>=max(IndexType(1),n));
#   endif

//
//  Call implementation
//
    const IndexType info = external::tri_impl(A, piv, work);

    return info;
}

#endif // USE_CXXLAPACK

//-- (ge)tri [real/complex variant with temporary workspace] -------------------
template <typename MA, typename VPIV>
typename RestrictTo<IsGeMatrix<MA>::value
                 && IsIntegerDenseVector<VPIV>::value,
         typename RemoveRef<MA>::Type::IndexType>::Type
tri(MA          &&A,
    const VPIV  &piv)
{
    typedef typename RemoveRef<MA>::Type::Vector WorkVector;

    WorkVector  work;
    return tri(A, piv, work);
}

} } // namespace lapack, flens

#endif // FLENS_LAPACK_GE_TRI_TCC