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*****************************************************************************
* Contents: Native high-level C interface to LAPACK function zgesvdx
* Author: Intel Corporation
*****************************************************************************/

#include "lapacke_utils.h"

lapack_int LAPACKE_zgesvdx( int matrix_layout, char jobu, char jobvt, char range,
                            lapack_int m, lapack_int n, lapack_complex_double* a,
                            lapack_int lda, double vl, double vu,
                            lapack_int il, lapack_int iu, lapack_int* ns,
                            double* s, lapack_complex_double* u, lapack_int ldu,
                            lapack_complex_double* vt, lapack_int ldvt,
                            lapack_int* superb )
{
    lapack_int info = 0;
    lapack_int lwork = -1;
    lapack_complex_double* work = NULL;
    lapack_complex_double work_query;
    double* rwork = NULL;
    lapack_int lrwork = MAX(1,MIN(m,n)*(MIN(m,n)*2+15*MIN(m,n)));
    lapack_int* iwork = NULL;
    lapack_int i;
    if( matrix_layout != LAPACK_COL_MAJOR && matrix_layout != LAPACK_ROW_MAJOR ) {
        LAPACKE_xerbla( "LAPACKE_zgesvdx", -1 );
        return -1;
    }
#ifndef LAPACK_DISABLE_NAN_CHECK
    if( LAPACKE_get_nancheck() ) {
        /* Optionally check input matrices for NaNs */
        if( LAPACKE_zge_nancheck( matrix_layout, m, n, a, lda ) ) {
            return -6;
        }
    }
#endif
    /* Query optimal working array(s) size */
    info = LAPACKE_zgesvdx_work( matrix_layout, jobu, jobvt, range,
                                 m, n, a, lda, vl, vu, il, iu, ns, s, u,
                                 ldu, vt, ldvt, &work_query, lwork, rwork, iwork );
    if( info != 0 ) {
        goto exit_level_0;
    }
    lwork = LAPACK_Z2INT (work_query);
    /* Allocate memory for work arrays */
    work = (lapack_complex_double*)
        LAPACKE_malloc( sizeof(lapack_complex_double) * lwork );
    if( work == NULL ) {
        info = LAPACK_WORK_MEMORY_ERROR;
        goto exit_level_1;
    }
    rwork = (double*)LAPACKE_malloc( sizeof(double) * lrwork );
    if( rwork == NULL ) {
        info = LAPACK_WORK_MEMORY_ERROR;
        goto exit_level_0;
    }
    iwork = (lapack_int*)LAPACKE_malloc( sizeof(lapack_int) * MAX(1,(12*MIN(m,n))) );
    if( iwork == NULL ) {
        info = LAPACK_WORK_MEMORY_ERROR;
        goto exit_level_2;
    }
    /* Call middle-level interface */
    info = LAPACKE_zgesvdx_work( matrix_layout, jobu, jobvt,  range,
                                 m, n, a, lda, vl, vu, il, iu, ns, s, u,
                                 ldu, vt, ldvt, work, lwork, rwork, iwork );
    /* Backup significant data from working array(s) */
    for( i=0; i<12*MIN(m,n)-1; i++ ) {
        superb[i] = iwork[i+1];
    }
    /* Release memory and exit */
    LAPACKE_free( iwork );
exit_level_2:
    LAPACKE_free( work );
exit_level_1:
    LAPACKE_free( rwork );
exit_level_0:
    if( info == LAPACK_WORK_MEMORY_ERROR ) {
        LAPACKE_xerbla( "LAPACKE_zgesvdx", info );
    }
    return info;
}
