/* ieee-utils/fp-gnux86.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough

 * 

 * 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 <stdio.h>

#include <fpu_control.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_ieee_utils.h>

  /* Handle libc5, where _FPU_SETCW is not available, suggested by

     OKUJI Yoshinori <okuji@gnu.org> and Evgeny Stambulchik

     <fnevgeny@plasma-gate.weizmann.ac.il> */

#ifndef _FPU_SETCW

#include <i386/fpu_control.h>

#define _FPU_SETCW(cw) __setfpucw(cw)

#endif

int

gsl_ieee_set_mode (int precision, int rounding, int exception_mask)

{

  unsigned short mode = 0 ;

  switch (precision)

    {

    case GSL_IEEE_SINGLE_PRECISION:

      mode |= _FPU_SINGLE ;

      break ;

    case GSL_IEEE_DOUBLE_PRECISION:

      mode |= _FPU_DOUBLE ;

      break ;

    case GSL_IEEE_EXTENDED_PRECISION:

      mode |= _FPU_EXTENDED ;

      break ;

    default:

      mode |= _FPU_EXTENDED ;

    }

  switch (rounding)

    {

    case GSL_IEEE_ROUND_TO_NEAREST:

      mode |= _FPU_RC_NEAREST ;

      break ;

    case GSL_IEEE_ROUND_DOWN:

      mode |= _FPU_RC_DOWN ;

      break ;

    case GSL_IEEE_ROUND_UP:

      mode |= _FPU_RC_UP ;

      break ;

    case GSL_IEEE_ROUND_TO_ZERO:

      mode |= _FPU_RC_ZERO ;

      break ;

    default:

      mode |= _FPU_RC_NEAREST ;

    }

  if (exception_mask & GSL_IEEE_MASK_INVALID)

    mode |= _FPU_MASK_IM ;

  if (exception_mask & GSL_IEEE_MASK_DENORMALIZED)

    mode |= _FPU_MASK_DM ;

  if (exception_mask & GSL_IEEE_MASK_DIVISION_BY_ZERO)

    mode |= _FPU_MASK_ZM ;

  if (exception_mask & GSL_IEEE_MASK_OVERFLOW)

    mode |= _FPU_MASK_OM ;

  if (exception_mask & GSL_IEEE_MASK_UNDERFLOW)

    mode |= _FPU_MASK_UM ;

  if (exception_mask & GSL_IEEE_TRAP_INEXACT)

    {

      mode &= ~ _FPU_MASK_PM ;

    }

  else

    {

      mode |= _FPU_MASK_PM ;

    }

  _FPU_SETCW(mode) ;

#if HAVE_FPU_X86_SSE

#define _FPU_SETMXCSR(cw_sse) asm volatile ("ldmxcsr %0" : : "m" (*&cw_sse))

  {

    unsigned int mode_sse = 0;

    mode_sse |= (mode & 0x3f)<<7;  /* exception masks */

    mode_sse |= (mode & 0xc00)<<3;    /* rounding control */

    _FPU_SETMXCSR(mode_sse);

  }

#endif

  return GSL_SUCCESS ;

}