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

#include "lapacke_utils.h"

lapack_int LAPACKE_ssbevx_work( int matrix_layout, char jobz, char range,
                                char uplo, lapack_int n, lapack_int kd,
                                float* ab, lapack_int ldab, float* q,
                                lapack_int ldq, float vl, float vu,
                                lapack_int il, lapack_int iu, float abstol,
                                lapack_int* m, float* w, float* z,
                                lapack_int ldz, float* work, lapack_int* iwork,
                                lapack_int* ifail )
{
    lapack_int info = 0;
    if( matrix_layout == LAPACK_COL_MAJOR ) {
        /* Call LAPACK function and adjust info */
        LAPACK_ssbevx( &jobz, &range, &uplo, &n, &kd, ab, &ldab, q, &ldq, &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 ldab_t = MAX(1,kd+1);
        lapack_int ldq_t = MAX(1,n);
        lapack_int ldz_t = MAX(1,n);
        float* ab_t = NULL;
        float* q_t = NULL;
        float* z_t = NULL;
        /* Check leading dimension(s) */
        if( ldab < n ) {
            info = -8;
            LAPACKE_xerbla( "LAPACKE_ssbevx_work", info );
            return info;
        }
        if( ldq < n ) {
            info = -10;
            LAPACKE_xerbla( "LAPACKE_ssbevx_work", info );
            return info;
        }
        if( ldz < ncols_z ) {
            info = -19;
            LAPACKE_xerbla( "LAPACKE_ssbevx_work", info );
            return info;
        }
        /* Allocate memory for temporary array(s) */
        ab_t = (float*)LAPACKE_malloc( sizeof(float) * ldab_t * MAX(1,n) );
        if( ab_t == NULL ) {
            info = LAPACK_TRANSPOSE_MEMORY_ERROR;
            goto exit_level_0;
        }
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            q_t = (float*)LAPACKE_malloc( sizeof(float) * ldq_t * MAX(1,n) );
            if( q_t == NULL ) {
                info = LAPACK_TRANSPOSE_MEMORY_ERROR;
                goto exit_level_1;
            }
        }
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            z_t = (float*)
                LAPACKE_malloc( sizeof(float) * ldz_t * MAX(1,ncols_z) );
            if( z_t == NULL ) {
                info = LAPACK_TRANSPOSE_MEMORY_ERROR;
                goto exit_level_2;
            }
        }
        /* Transpose input matrices */
        LAPACKE_ssb_trans( matrix_layout, uplo, n, kd, ab, ldab, ab_t, ldab_t );
        /* Call LAPACK function and adjust info */
        LAPACK_ssbevx( &jobz, &range, &uplo, &n, &kd, ab_t, &ldab_t, q_t,
                       &ldq_t, &vl, &vu, &il, &iu, &abstol, m, w, z_t, &ldz_t,
                       work, iwork, ifail, &info );
        if( info < 0 ) {
            info = info - 1;
        }
        /* Transpose output matrices */
        LAPACKE_ssb_trans( LAPACK_COL_MAJOR, uplo, n, kd, ab_t, ldab_t, ab,
                           ldab );
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_sge_trans( LAPACK_COL_MAJOR, n, n, q_t, ldq_t, q, ldq );
        }
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_sge_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_2:
        if( LAPACKE_lsame( jobz, 'v' ) ) {
            LAPACKE_free( q_t );
        }
exit_level_1:
        LAPACKE_free( ab_t );
exit_level_0:
        if( info == LAPACK_TRANSPOSE_MEMORY_ERROR ) {
            LAPACKE_xerbla( "LAPACKE_ssbevx_work", info );
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_ssbevx_work", info );
    }
    return info;
}
