/*
 Copyright (c) 2011, Intel Corporation. All rights reserved.

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 ********************************************************************************
 *   Content : Eigen bindings to LAPACKe
 *    Householder QR decomposition of a matrix w/o pivoting based on
 *    LAPACKE_?geqrf function.
 ********************************************************************************
*/

#ifndef EIGEN_QR_LAPACKE_H
#define EIGEN_QR_LAPACKE_H

#include "./InternalHeaderCheck.h"

namespace Eigen { 

namespace internal {

namespace lapacke_helpers {

template<typename MatrixQR, typename HCoeffs>
struct lapacke_hqr
{
  static void run(MatrixQR& mat, HCoeffs& hCoeffs, Index = 32, typename MatrixQR::Scalar* = 0)
  {
    lapack_int m = to_lapack(mat.rows());
    lapack_int n = to_lapack(mat.cols());
    lapack_int lda = to_lapack(mat.outerStride());
    lapack_int matrix_order = lapack_storage_of(mat);
    geqrf(matrix_order, m, n, to_lapack(mat.data()), lda, to_lapack(hCoeffs.data()));
    hCoeffs.adjointInPlace();
  }
};

}

/** \internal Specialization for the data types supported by LAPACKe */
#define EIGEN_LAPACKE_HH_QR(EIGTYPE) \
template<typename MatrixQR, typename HCoeffs> \
struct householder_qr_inplace_blocked<MatrixQR, HCoeffs, EIGTYPE, true> : public lapacke_helpers::lapacke_hqr<MatrixQR, HCoeffs> {};

EIGEN_LAPACKE_HH_QR(double)
EIGEN_LAPACKE_HH_QR(float)
EIGEN_LAPACKE_HH_QR(std::complex<double>)
EIGEN_LAPACKE_HH_QR(std::complex<float>)

#undef EIGEN_LAPACKE_HH_QR

} // end namespace internal

} // end namespace Eigen

#endif // EIGEN_QR_LAPACKE_H