text: /*-
   * 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: src/sys/i386/include/floatingpoint.h,v 1.10.2.1 2002/06/30 00:55:09 bde Exp $
   */
  
  #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()	((fp_rnd_t)					\
  	((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF))
  #define	fpsetround(m)	((fp_rnd_t)					\
  	__fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF))
  #define	fpgetprec()	((fp_prec_t)					\
  	((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF))
  #define	fpsetprec(m)	((fp_prec_t)					\
  	__fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF))
  #define	fpgetmask()	((fp_except_t)					\
  	((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF))
  #define	fpsetmask(m)	((fp_except_t)					\
  	(~__fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF)) &	\
  	    (FP_MSKS_FLD >> FP_MSKS_OFF))
  #define	fpgetsticky()	((fp_except_t)					\
  	((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF))
  #define	fpresetsticky(m) ((fp_except_t)					\
  	__fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF))
  #define	fpsetsticky(m)	fpresetsticky(m)
  
  #endif /* !_FLOATINGPOINT_H_ */
  