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
/*
 *   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.
 */

/* Based on
 *
       SUBROUTINE DSYTRS( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
       SUBROUTINE ZSYTRS( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
 *
 *  -- LAPACK routine (version 3.3.1) --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *  -- April 2011                                                      --
 *
 */

#ifndef FLENS_LAPACK_SY_TRS_TCC
#define FLENS_LAPACK_SY_TRS_TCC 1

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

namespace flens { namespace lapack {

//== interface for external lapack =============================================

#ifdef USE_CXXLAPACK

namespace external {

//-- (sy)trs [real variant] ----------------------------------------------------

template <typename MA, typename VP, typename MB>
void
trs_impl(const SyMatrix<MA> &A, const DenseVector<VP> &piv,
         GeMatrix<MB> &B)
{
    typedef typename GeMatrix<MA>::IndexType  IndexType;

    IndexType info;
    info = cxxlapack::sytrs<IndexType>(getF77Char(A.upLo()),
                                       A.dim(),
                                       B.numCols(),
                                       A.data(),
                                       A.leadingDimension(),
                                       piv.data(),
                                       B.data(),
                                       B.leadingDimension());
    ASSERT(info==0);
}

// namespace external

#endif // USE_CXXLAPACK


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


#ifdef USE_CXXLAPACK

//-- (sy)trs [real and complex variant] ----------------------------------------

template <typename MA, typename VPIV, typename MB>
typename RestrictTo<IsSyMatrix<MA>::value
                 && IsIntegerDenseVector<VPIV>::value
                 && IsGeMatrix<MB>::value,
        void>::Type
trs(const MA &A, const VPIV &piv, MB &&B)
{
    LAPACK_DEBUG_OUT("(sy)trs [real/complex]");
//
//  Remove references from rvalue types
//
    typedef typename RemoveRef<MA>::Type     MatrixA;
    typedef typename MatrixA::IndexType      IndexType;
    typedef typename RemoveRef<MB>::Type     MatrixB;

//
//  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);

    ASSERT(B.firstRow()==1);
    ASSERT(B.firstCol()==1);
    ASSERT(B.numRows()==n);
#   endif

//
//  Call implementation
//
    external::trs_impl(A, piv, B);
}

//-- (sy)trs [variant if rhs is vector] ----------------------------------------

template <typename MA, typename VPIV, typename VB>
typename RestrictTo<IsSyMatrix<MA>::value
                 && IsIntegerDenseVector<VPIV>::value
                 && IsDenseVector<VB>::value,
          void>::Type
trs(const MA &A, const VPIV &piv, VB &&b)
{
//
//  Remove references from rvalue types
//
    typedef typename RemoveRef<MA>::Type    MatrixA;
    typedef typename RemoveRef<VB>::Type    VectorB;

//
//  Create matrix view from vector b and call above variant
//
    typedef typename VectorB::ElementType  ElementType;
    typedef typename VectorB::IndexType    IndexType;

    const IndexType    n     = b.length();
    const StorageOrder order = MatrixA::Engine::order;

    GeMatrix<FullStorageView<ElementType, order> >  B(n1, b, n);

    trs(A, piv, B);
}

#endif // USE_CXXLAPACK

} } // namespace lapack, flens

#endif // FLENS_LAPACK_SY_TRS_TCC