/* ieee-utils/fp-darwin.c

 * 

 * Copyright (C) 2001 Rodney Sparapani <rsparapa@mcw.edu>

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

#include <architecture/ppc/fp_regs.h> 

#include <gsl/gsl_ieee_utils.h>

#include <gsl/gsl_errno.h>

int

gsl_ieee_set_mode (int precision, int rounding, int exception_mask)

{

  ppc_fp_scr_t fp_scr = get_fp_scr() ;

  switch (precision)

    {

    case GSL_IEEE_SINGLE_PRECISION:

      GSL_ERROR ("powerpc only supports default precision rounding", GSL_EUNSUP);

      break ;

    case GSL_IEEE_DOUBLE_PRECISION:

      GSL_ERROR ("powerpc only supports default precision rounding", GSL_EUNSUP);

      break ;

    case GSL_IEEE_EXTENDED_PRECISION:

      GSL_ERROR ("powerpc only supports default precision rounding", GSL_EUNSUP);

      break ;

    }

  switch (rounding)

    {

    case GSL_IEEE_ROUND_TO_NEAREST:

      fp_scr.rn = RN_NEAREST ;

      break ;

    case GSL_IEEE_ROUND_DOWN:

      fp_scr.rn = RN_TOWARD_MINUS ;

      break ;

    case GSL_IEEE_ROUND_UP:

      fp_scr.rn = RN_TOWARD_PLUS ;

      break ;

    case GSL_IEEE_ROUND_TO_ZERO:

      fp_scr.rn = RN_TOWARD_ZERO ;

      break ;

    default:

      fp_scr.rn = RN_NEAREST ;

    }

  if (exception_mask & GSL_IEEE_MASK_INVALID)

    fp_scr.ve = 0 ;                             //ve bit:  invalid op exception enable

  if (exception_mask & GSL_IEEE_MASK_DENORMALIZED)

    {

      /* do nothing */

    }

  else

    {

      GSL_ERROR ("powerpc does not support the denormalized operand exception. "

                 "Use 'mask-denormalized' to work around this.", GSL_EUNSUP) ;

    }

  if (exception_mask & GSL_IEEE_MASK_DIVISION_BY_ZERO)

    fp_scr.ze = 0 ;                             //ze bit:  zero divide exception enable

  if (exception_mask & GSL_IEEE_MASK_OVERFLOW)

    fp_scr.oe = 0 ;                             //oe bit:  overflow exception enable

  if (exception_mask & GSL_IEEE_MASK_UNDERFLOW)

    fp_scr.ue  = 0 ;                            //ue bit:  underflow exception enable

  if (exception_mask & GSL_IEEE_TRAP_INEXACT)

    {

      fp_scr.xe = 1 ;                           //xe bit:  inexact exception enable

    }

  else

    {

      fp_scr.xe = 01 ;                  

    }

  set_fp_scr(fp_scr);

  return GSL_SUCCESS ;

}