floatingpoint.h revision 2941
1139804Simp/*- 22729Sdfr * Copyright (c) 1993 Andrew Moore, Talke Studio 32729Sdfr * All rights reserved. 42729Sdfr * 52729Sdfr * Redistribution and use in source and binary forms, with or without 62729Sdfr * modification, are permitted provided that the following conditions 72729Sdfr * are met: 82729Sdfr * 1. Redistributions of source code must retain the above copyright 92729Sdfr * notice, this list of conditions and the following disclaimer. 102729Sdfr * 2. Redistributions in binary form must reproduce the above copyright 112729Sdfr * notice, this list of conditions and the following disclaimer in the 122729Sdfr * documentation and/or other materials provided with the distribution. 132729Sdfr * 3. All advertising materials mentioning features or use of this software 142729Sdfr * must display the following acknowledgement: 152729Sdfr * This product includes software developed by the University of 162729Sdfr * California, Berkeley and its contributors. 172729Sdfr * 4. Neither the name of the University nor the names of its contributors 182729Sdfr * may be used to endorse or promote products derived from this software 19140614Srwatson * without specific prior written permission. 20140614Srwatson * 21140614Srwatson * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22140614Srwatson * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23140614Srwatson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24140614Srwatson * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25140614Srwatson * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26140614Srwatson * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27140614Srwatson * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28140614Srwatson * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29140614Srwatson * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30140614Srwatson * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31140614Srwatson * SUCH DAMAGE. 32140614Srwatson * 33140614Srwatson * from: @(#) floatingpoint.h 1.0 (Berkeley) 9/23/93 34140614Srwatson * $Id: floatingpoint.h,v 1.5 1994/08/04 19:16:36 wollman Exp $ 35140614Srwatson */ 36140614Srwatson 37140614Srwatson#ifndef _FLOATINGPOINT_H_ 38140614Srwatson#define _FLOATINGPOINT_H_ 39140614Srwatson 40140614Srwatson/* 41140614Srwatson * IEEE floating point structure and function definitions 42140614Srwatson */ 43140614Srwatson 44140614Srwatson/*- 45140614Srwatson * XXX the following undocumented pollution is exported: 46140614Srwatson * fpsetsticky(). 47140614Srwatson * FP*FLD, FP*OFF and FP*REG from <machine/ieeefp.h> 48140614Srwatson */ 492729Sdfr 50116182Sobrien#include <sys/cdefs.h> 51116182Sobrien#include <machine/ieeefp.h> 52116182Sobrien 5359839Speter#ifdef __GNUC__ 54140614Srwatson 5559839Speter#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 562729Sdfr#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 572729Sdfr#define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 5811626Sbde#define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 592729Sdfr 602729Sdfr/* 6182607Sdillon * return the contents of a FP register 62140614Srwatson */ 6382607Sdillonstatic __inline__ int 64129882Sphk__fpgetreg(int _reg) 652729Sdfr{ 6669449Salfred unsigned short _mem; 67140839Ssobomax 6811626Sbde /*- 6959839Speter * This is more efficient than it looks. The switch gets optimized 7059839Speter * away if _reg is constant. 7168024Srwatson * 722729Sdfr * The default case only supports _reg == 0. We could handle more 7359839Speter * registers (e.g., tags) using fnstenv, but the interface doesn't 7459839Speter * support more. 7592723Salfred */ 7692723Salfred switch(_reg) { 7792723Salfred default: 7810358Sjulian __fnstcw(&_mem); 79100523Salfred break; 80100523Salfred case FP_STKY_REG: 81100523Salfred __fnstsw(&_mem); 82100523Salfred break; 83100523Salfred } 84140614Srwatson return _mem; 85140614Srwatson} 86140614Srwatson 87140614Srwatson/* 88140614Srwatson * set a FP mode; return previous mode 892729Sdfr */ 9092723Salfredstatic __inline__ int 912729Sdfr__fpsetreg(int _m, int _reg, int _fld, int _off) 9211626Sbde{ 9312819Sphk unsigned _env[7]; 9411626Sbde unsigned _p; 9511626Sbde 9611626Sbde /* 972729Sdfr * _reg == 0 could be handled better using fnstcw/fldcw. 9859839Speter */ 9959839Speter __fnstenv(_env); 10059839Speter _p = (_env[_reg] & _fld) >> _off; 10159839Speter _env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld); 10259839Speter __fldenv(_env); 10359839Speter return _p; 10459839Speter} 10559839Speter 10659839Speter#endif /* __GNUC__ */ 10759839Speter 10859839Speter/* 10959839Speter * SysV/386 FP control interface 11059839Speter */ 11159839Speter#define fpgetround() ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF) 11259839Speter#define fpsetround(m) __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF) 11359839Speter#define fpgetprec() ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF) 11459839Speter#define fpsetprec(m) __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF) 11559839Speter#define fpgetmask() ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF) 11659839Speter#define fpsetmask(m) __fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF) 11759839Speter#define fpgetsticky() ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF) 11859839Speter#define fpresetsticky(m) __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF) 11959839Speter#define fpsetsticky(m) fpresetsticky(m) 12059839Speter 12159839Speter#endif /* !_FLOATINGPOINT_H_ */ 12259839Speter