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

#include "lapacke_utils.h"

lapack_int LAPACKE_dpteqr_work( int matrix_layout, char compz, lapack_int n,
                                double* d, double* e, double* z, lapack_int ldz,
                                double* work )
{
    lapack_int info = 0;
    if( matrix_layout == LAPACK_COL_MAJOR ) {
        /* Call LAPACK function and adjust info */
        LAPACK_dpteqr( &compz, &n, d, e, z, &ldz, work, &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( ldz < n ) {
            info = -7;
            LAPACKE_xerbla( "LAPACKE_dpteqr_work", info );
            return info;
        }
        /* Allocate memory for temporary array(s) */
        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;
        }
        /* Transpose input matrices */
        if( LAPACKE_lsame( compz, 'v' ) ) {
            LAPACKE_dge_trans( matrix_layout, n, n, z, ldz, z_t, ldz_t );
        }
        /* Call LAPACK function and adjust info */
        LAPACK_dpteqr( &compz, &n, d, e, z_t, &ldz_t, work, &info );
        if( info < 0 ) {
            info = info - 1;
        }
        /* Transpose output matrices */
        LAPACKE_dge_trans( LAPACK_COL_MAJOR, n, n, z_t, ldz_t, z, ldz );
        /* Release memory and exit */
        LAPACKE_free( z_t );
exit_level_0:
        if( info == LAPACK_TRANSPOSE_MEMORY_ERROR ) {
            LAPACKE_xerbla( "LAPACKE_dpteqr_work", info );
        }
    } else {
        info = -1;
        LAPACKE_xerbla( "LAPACKE_dpteqr_work", info );
    }
    return info;
}
