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