/* ieee-utils/fp-aix.c *  * Copyright (C) 1996, 1997, 1998, 1999, 2000 Tim Mooney *  * 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 2 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 <math.h>#include <fptrap.h>#include <float.h>#include <gsl/gsl_ieee_utils.h>#include <gsl/gsl_errno.h>intgsl_ieee_set_mode (int precision, int rounding, int exception_mask){  fptrap_t   mode = 0 ;  fprnd_t    rnd  = 0 ;  switch (precision)    {    /* I'm not positive about AIX only supporting default precision rounding,     * but this is the best assumption until it's proven otherwise. */    case GSL_IEEE_SINGLE_PRECISION:      GSL_ERROR ("AIX only supports default precision rounding",                 GSL_EUNSUP) ;      break ;    case GSL_IEEE_DOUBLE_PRECISION:      GSL_ERROR ("AIX only supports default precision rounding",                 GSL_EUNSUP) ;      break ;    case GSL_IEEE_EXTENDED_PRECISION:      GSL_ERROR ("AIX only supports default precision rounding",                 GSL_EUNSUP) ;      break ;    }  switch (rounding)    {    case GSL_IEEE_ROUND_TO_NEAREST:      rnd = FP_RND_RN ;      fp_swap_rnd (rnd) ;      break ;    case GSL_IEEE_ROUND_DOWN:      rnd = FP_RND_RM ;      fp_swap_rnd (rnd) ;      break ;    case GSL_IEEE_ROUND_UP:      rnd = FP_RND_RP ;      fp_swap_rnd (rnd) ;      break ;    case GSL_IEEE_ROUND_TO_ZERO:      rnd = FP_RND_RZ ;      fp_swap_rnd (rnd) ;      break ;    default:      rnd = FP_RND_RN ;      fp_swap_rnd (rnd) ;    }  /* Turn on all the exceptions apart from 'inexact' */  mode = TRP_INVALID | TRP_DIV_BY_ZERO | TRP_OVERFLOW | TRP_UNDERFLOW ;  if (exception_mask & GSL_IEEE_MASK_INVALID)    mode &= ~ TRP_INVALID ;  if (exception_mask & GSL_IEEE_MASK_DENORMALIZED)    {      /* do nothing */    }  else     {      GSL_ERROR ("AIX 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)    mode &= ~ TRP_DIV_BY_ZERO ;  if (exception_mask & GSL_IEEE_MASK_OVERFLOW)    mode &= ~ TRP_OVERFLOW ;  if (exception_mask & GSL_IEEE_MASK_UNDERFLOW)    mode &=  ~ TRP_UNDERFLOW ;  if (exception_mask & GSL_IEEE_TRAP_INEXACT)    {      mode |= TRP_INEXACT ;    }  else    {      mode &= ~ TRP_INEXACT ;    }  /* AIX appears to require two steps -- first enable floating point traps   * in general... */  fp_trap(FP_TRAP_SYNC);  /* next, enable the traps we're interested in */  fp_enable(mode);  return GSL_SUCCESS ;}