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

#include "lapacke_utils.h"

lapack_int LAPACKE_dstegr_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, lapack_int* isuppz,
                                double* work, lapack_int lwork,
                                lapack_int* iwork, lapack_int liwork )
{
    lapack_int info = 0;
    if( matrix_layout == LAPACK_COL_MAJOR ) {
        /* Call LAPACK function and adjust info */
        LAPACK_dstegr( &jobz, &range, &n, d, e, &vl, &vu, &il, &iu, &abstol, m,
                       w, z, &ldz, isuppz, work, &lwork, iwork, &liwork,
                       &info );
        if( info < 0 ) {
            info = info - 1;
        }
    } else if( matrix_layout == LAPACK_ROW_MAJOR ) {
        lapack_int ldz_t = MAX(1,n);
        double* z_t = NULL;
        /* Check leading dimension(s) */
        if( ( LAPACKE_lsame( jobz, 'v' ) && ( ldz < ldz_t )  ) || ( ldz < 1 ) ) {
            info = -15;
            LAPACKE_xerbla( "LAPACKE_dstegr_work", info );
            return info;
        }
        /* Query optimal working array(s) size if requested */
        if( liwork == -1 || lwork == -1 ) {
            LAPACK_dstegr( &jobz, &range, &n, d, e, &vl, &vu, &il, &iu, &abstol,
                           m, w, z, &ldz_t, isuppz, work, &lwork, iwork,
                           &liwork, &info );
            return (info < 0) ? (info - 1) : info;
        }
        /* Allocate memory for temporary array(s) */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            /* Let be always 'n' instead of 'm' */
            z_t = (double*)LAPACKE_malloc( sizeof(double) * ldz_t * MAX(1,n) );
            if( z_t == NULL ) {
                info = LAPACK_TRANSPOSE_MEMORY_ERROR;
                goto exit_level_0;
            }
        }
        /* Call LAPACK function and adjust info */
        LAPACK_dstegr( &jobz, &range, &n, d, e, &vl, &vu, &il, &iu, &abstol, m,
                       w, z_t, &ldz_t, isuppz, work, &lwork, iwork, &liwork,
                       &info );
        if( info < 0 ) {
            info = info - 1;
        }
        /* Transpose output matrices */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_dge_trans( LAPACK_COL_MAJOR, n, *m, 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_dstegr_work", info );
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_dstegr_work", info );
    }
    return info;
}
