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*****************************************************************************
* Contents: Native middle-level C interface to LAPACK function zhbevd_2stage
* Author: Intel Corporation
*****************************************************************************/

#include "lapacke_utils.h"

lapack_int LAPACKE_zhbevd_2stage_work( int matrix_layout, char jobz, char uplo,
                                lapack_int n, lapack_int kd,
                                lapack_complex_double* ab, lapack_int ldab,
                                double* w, lapack_complex_double* z,
                                lapack_int ldz, lapack_complex_double* work,
                                lapack_int lwork, double* rwork,
                                lapack_int lrwork, lapack_int* iwork,
                                lapack_int liwork )
{
    lapack_int info = 0;
    if( matrix_layout == LAPACK_COL_MAJOR ) {
        /* Call LAPACK function and adjust info */
        LAPACK_zhbevd_2stage( &jobz, &uplo, &n, &kd, ab, &ldab, w, z, &ldz, work,
                       &lwork, rwork, &lrwork, iwork, &liwork, &info );
        if( info < 0 ) {
            info = info - 1;
        }
    } else if( matrix_layout == LAPACK_ROW_MAJOR ) {
        lapack_int ldab_t = MAX(1,kd+1);
        lapack_int ldz_t = MAX(1,n);
        lapack_complex_double* ab_t = NULL;
        lapack_complex_double* z_t = NULL;
        /* Check leading dimension(s) */
        if( ldab < n ) {
            info = -7;
            LAPACKE_xerbla( "LAPACKE_zhbevd_2stage_work", info );
            return info;
        }
        if( ldz < n ) {
            info = -10;
            LAPACKE_xerbla( "LAPACKE_zhbevd_2stage_work", info );
            return info;
        }
        /* Query optimal working array(s) size if requested */
        if( liwork == -1 || lrwork == -1 || lwork == -1 ) {
            LAPACK_zhbevd_2stage( &jobz, &uplo, &n, &kd, ab, &ldab_t, w, z, &ldz_t,
                           work, &lwork, rwork, &lrwork, iwork, &liwork,
                           &info );
            return (info < 0) ? (info - 1) : info;
        }
        /* Allocate memory for temporary array(s) */
        ab_t = (lapack_complex_double*)
            LAPACKE_malloc( sizeof(lapack_complex_double) * ldab_t * MAX(1,n) );
        if( ab_t == NULL ) {
            info = LAPACK_TRANSPOSE_MEMORY_ERROR;
            goto exit_level_0;
        }
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            z_t = (lapack_complex_double*)
                LAPACKE_malloc( sizeof(lapack_complex_double) *
                                ldz_t * MAX(1,n) );
            if( z_t == NULL ) {
                info = LAPACK_TRANSPOSE_MEMORY_ERROR;
                goto exit_level_1;
            }
        }
        /* Transpose input matrices */
        LAPACKE_zhb_trans( matrix_layout, uplo, n, kd, ab, ldab, ab_t, ldab_t );
        /* Call LAPACK function and adjust info */
        LAPACK_zhbevd_2stage( &jobz, &uplo, &n, &kd, ab_t, &ldab_t, w, z_t, &ldz_t,
                       work, &lwork, rwork, &lrwork, iwork, &liwork, &info );
        if( info < 0 ) {
            info = info - 1;
        }
        /* Transpose output matrices */
        LAPACKE_zhb_trans( LAPACK_COL_MAJOR, uplo, n, kd, ab_t, ldab_t, ab,
                           ldab );
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_zge_trans( LAPACK_COL_MAJOR, n, n, z_t, ldz_t, z, ldz );
        }
        /* Release memory and exit */
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_free( z_t );
        }
exit_level_1:
        LAPACKE_free( ab_t );
exit_level_0:
        if( info == LAPACK_TRANSPOSE_MEMORY_ERROR ) {
            LAPACKE_xerbla( "LAPACKE_zhbevd_2stage_work", info );
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_zhbevd_2stage_work", info );
    }
    return info;
}
