/* 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 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 <math.h>
#include <fptrap.h>
#include <float.h>
#include <gsl/gsl_ieee_utils.h>
#include <gsl/gsl_errno.h>
/* GCC uses a common float.h for all platforms, and ignores all vendor
specific code in float.h. That causes problems with fprnd_t,
FP_RND_RZ, FP_RND_RN and FP_RND_RP on AIX.
Personally I consider that a bug, and was advised by a GCC developer
to report this as a bug, which I did.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46155
However, there is not universal agreement whether this is a gcc bug, so
the issue needs to be worked around on AIX.
David Kirkby, 26th October 2010. */
#if !HAVE_DECL_FPRND_T
typedef unsigned short fprnd_t;
#endif
#ifndef FP_RND_RZ
#define FP_RND_RZ 0
#endif
#ifndef FP_RND_RN
#define FP_RND_RN 1
#endif
#ifndef FP_RND_RP
#define FP_RND_RP 2
#endif
#ifndef FP_RND_RM
#define FP_RND_RM 3
#endif
int
gsl_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 ;
}