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/*-
* Copyright (c) 1993 Andrew Moore, Talke Studio
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#) floatingpoint.h 1.0 (Berkeley) 9/23/93
* $FreeBSD$
*/
#ifndef _FLOATINGPOINT_H_
#define _FLOATINGPOINT_H_
/*
* IEEE floating point structure and function definitions
*/
/*-
* XXX the following undocumented pollution is exported:
* fpsetsticky().
* FP*FLD, FP*OFF and FP*REG from <machine/ieeefp.h>
*/
#include <sys/cdefs.h>
#include <machine/ieeefp.h>
#ifdef __GNUC__
#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
#define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
#define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
/*
* return the contents of a FP register
*/
static __inline__ int
__fpgetreg(int _reg)
{
unsigned short _mem;
/*-
* This is more efficient than it looks. The switch gets optimized
* away if _reg is constant.
*
* The default case only supports _reg == 0. We could handle more
* registers (e.g., tags) using fnstenv, but the interface doesn't
* support more.
*/
switch(_reg) {
default:
__fnstcw(&_mem);
break;
case FP_STKY_REG:
__fnstsw(&_mem);
break;
}
return _mem;
}
/*
* set a FP mode; return previous mode
*/
static __inline__ int
__fpsetreg(int _m, int _reg, int _fld, int _off)
{
unsigned _env[7];
unsigned _p;
/*
* _reg == 0 could be handled better using fnstcw/fldcw.
*/
__fnstenv(_env);
_p = (_env[_reg] & _fld) >> _off;
_env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld);
__fldenv(_env);
return _p;
}
#endif /* __GNUC__ */
/*
* SysV/386 FP control interface
*/
#define fpgetround() ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF)
#define fpsetround(m) __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF)
#define fpgetprec() ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF)
#define fpsetprec(m) __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF)
#define fpgetmask() ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF)
#define fpsetmask(m) __fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF)
#define fpgetsticky() ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF)
#define fpresetsticky(m) __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF)
#define fpsetsticky(m) fpresetsticky(m)
#endif /* !_FLOATINGPOINT_H_ */
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