/* 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 ;
}