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

#include "lapacke_utils.h"

lapack_int LAPACKE_dstevx_work( int matrix_layout, char jobz, char range,
                                lapack_int n, double* d, double* e, double vl,
                                double vu, lapack_int il, lapack_int iu,
                                double abstol, lapack_int* m, double* w,
                                double* z, lapack_int ldz, double* work,
                                lapack_int* iwork, lapack_int* ifail )
{
    lapack_int info = 0;
    if( matrix_layout == LAPACK_COL_MAJOR ) {
        /* Call LAPACK function and adjust info */
        LAPACK_dstevx( &jobz, &range, &n, d, e, &vl, &vu, &il, &iu, &abstol, m,
                       w, z, &ldz, work, iwork, ifail, &info );
        if( info < 0 ) {
            info = info - 1;
        }
    } else if( matrix_layout == LAPACK_ROW_MAJOR ) {
        lapack_int ncols_z = ( LAPACKE_lsame( range, 'a' ) ||
                             LAPACKE_lsame( range, 'v' ) ) ? n :
                             ( LAPACKE_lsame( range, 'i' ) ? (iu-il+1) : 1);
        lapack_int ldz_t = MAX(1,n);
        double* z_t = NULL;
        /* Check leading dimension(s) */
        if( ldz < ncols_z ) {
            info = -15;
            LAPACKE_xerbla( "LAPACKE_dstevx_work", info );
            return info;
        }
        /* Allocate memory for temporary array(s) */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            z_t = (double*)
                LAPACKE_malloc( sizeof(double) * ldz_t * MAX(1,ncols_z) );
            if( z_t == NULL ) {
                info = LAPACK_TRANSPOSE_MEMORY_ERROR;
                goto exit_level_0;
            }
        }
        /* Call LAPACK function and adjust info */
        LAPACK_dstevx( &jobz, &range, &n, d, e, &vl, &vu, &il, &iu, &abstol, m,
                       w, z_t, &ldz_t, work, iwork, ifail, &info );
        if( info < 0 ) {
            info = info - 1;
        }
        /* Transpose output matrices */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_dge_trans( LAPACK_COL_MAJOR, n, ncols_z, z_t, ldz_t, z,
                               ldz );
        }
        /* Release memory and exit */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_free( z_t );
        }
exit_level_0:
        if( info == LAPACK_TRANSPOSE_MEMORY_ERROR ) {
            LAPACKE_xerbla( "LAPACKE_dstevx_work", info );
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_dstevx_work", info );
    }
    return info;
}
