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* Contents: Native middle-level C interface to LAPACK function cuncsd
* Author: Intel Corporation
*****************************************************************************/

#include "lapacke_utils.h"

lapack_int LAPACKE_cuncsd_work( int matrix_layout, char jobu1, char jobu2,
                                char jobv1t, char jobv2t, char trans,
                                char signs, lapack_int m, lapack_int p,
                                lapack_int q, lapack_complex_float* x11,
                                lapack_int ldx11, lapack_complex_float* x12,
                                lapack_int ldx12, lapack_complex_float* x21,
                                lapack_int ldx21, lapack_complex_float* x22,
                                lapack_int ldx22, float* theta,
                                lapack_complex_float* u1, lapack_int ldu1,
                                lapack_complex_float* u2, lapack_int ldu2,
                                lapack_complex_float* v1t, lapack_int ldv1t,
                                lapack_complex_float* v2t, lapack_int ldv2t,
                                lapack_complex_float* work, lapack_int lwork,
                                float* rwork, lapack_int lrwork,
                                lapack_int* iwork )
{
    lapack_int info = 0;
    /* LAPACK function works with matrices in both layouts. It is supported
     * through TRANS parameter. So all conversion between layouts can be
     * completed in LAPACK function. See the table below which describes how
     * every LAPACKE call is forwarded to corresponding LAPACK call.
     *
     *   matrix_layout    | trans_LAPACKE | -> trans_LAPACK
     *                    |   (trans)     |       (ltrans)
     *   -----------------+---------------+----------------
     *   LAPACK_COL_MAJOR |     'N'       | ->     'N'
     *   LAPACK_COL_MAJOR |     'T'       | ->     'T'
     *   LAPACK_ROW_MAJOR |     'N'       | ->     'T'
     *   LAPACK_ROW_MAJOR |     'T'       | ->     'T'
     *       (note that for row major layout trans parameter is ignored)
     */
    if( matrix_layout == LAPACK_COL_MAJOR ||
        matrix_layout == LAPACK_ROW_MAJOR ) {
        char ltrans;
        if( !LAPACKE_lsame( trans, 't' ) && matrix_layout == LAPACK_COL_MAJOR ) {
            ltrans = 'n';
        } else {
            ltrans = 't';
        }
        /* Call LAPACK function and adjust info */
        LAPACK_cuncsd( &jobu1, &jobu2, &jobv1t, &jobv2t, &ltrans, &signs, &m,
                       &p, &q, x11, &ldx11, x12, &ldx12, x21, &ldx21, x22,
                       &ldx22, theta, u1, &ldu1, u2, &ldu2, v1t, &ldv1t, v2t,
                       &ldv2t, work, &lwork, rwork, &lrwork, iwork, &info );
        if( info < 0 ) {
            info = info - 1;
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_cuncsd_work", info );
    }
    return info;
}
