floatingpoint.h revision 2941
1326Salm/*- 2326Salm * Copyright (c) 1993 Andrew Moore, Talke Studio 3326Salm * All rights reserved. 4326Salm * 5326Salm * Redistribution and use in source and binary forms, with or without 6326Salm * modification, are permitted provided that the following conditions 7326Salm * are met: 8326Salm * 1. Redistributions of source code must retain the above copyright 9326Salm * notice, this list of conditions and the following disclaimer. 10326Salm * 2. Redistributions in binary form must reproduce the above copyright 11326Salm * notice, this list of conditions and the following disclaimer in the 12326Salm * documentation and/or other materials provided with the distribution. 13326Salm * 3. All advertising materials mentioning features or use of this software 14326Salm * must display the following acknowledgement: 15326Salm * This product includes software developed by the University of 16326Salm * California, Berkeley and its contributors. 17326Salm * 4. Neither the name of the University nor the names of its contributors 18326Salm * may be used to endorse or promote products derived from this software 19326Salm * without specific prior written permission. 20326Salm * 21326Salm * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22326Salm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23326Salm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24326Salm * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25326Salm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26326Salm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27326Salm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28326Salm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29326Salm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30326Salm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31326Salm * SUCH DAMAGE. 32326Salm * 33621Srgrimes * from: @(#) floatingpoint.h 1.0 (Berkeley) 9/23/93 342941Sbde * $Id: floatingpoint.h,v 1.5 1994/08/04 19:16:36 wollman Exp $ 35326Salm */ 36326Salm 372941Sbde#ifndef _FLOATINGPOINT_H_ 382941Sbde#define _FLOATINGPOINT_H_ 392941Sbde 40326Salm/* 412941Sbde * IEEE floating point structure and function definitions 42326Salm */ 43326Salm 442941Sbde/*- 452941Sbde * XXX the following undocumented pollution is exported: 462941Sbde * fpsetsticky(). 472941Sbde * FP*FLD, FP*OFF and FP*REG from <machine/ieeefp.h> 482941Sbde */ 49326Salm 50326Salm#include <sys/cdefs.h> 511834Swollman#include <machine/ieeefp.h> 52326Salm 53326Salm#ifdef __GNUC__ 54326Salm 552941Sbde#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 562941Sbde#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 572941Sbde#define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 582941Sbde#define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 59719Swollman 60326Salm/* 61326Salm * return the contents of a FP register 62326Salm */ 63338Salmstatic __inline__ int 64338Salm__fpgetreg(int _reg) 65326Salm{ 66338Salm unsigned short _mem; 67326Salm 682941Sbde /*- 692941Sbde * This is more efficient than it looks. The switch gets optimized 702941Sbde * away if _reg is constant. 712941Sbde * 722941Sbde * The default case only supports _reg == 0. We could handle more 732941Sbde * registers (e.g., tags) using fnstenv, but the interface doesn't 742941Sbde * support more. 752941Sbde */ 76338Salm switch(_reg) { 77326Salm default: 782941Sbde __fnstcw(&_mem); 79326Salm break; 80326Salm case FP_STKY_REG: 812941Sbde __fnstsw(&_mem); 82326Salm break; 83326Salm } 84338Salm return _mem; 85326Salm} 86326Salm 87326Salm/* 88326Salm * set a FP mode; return previous mode 89326Salm */ 90338Salmstatic __inline__ int 91338Salm__fpsetreg(int _m, int _reg, int _fld, int _off) 92326Salm{ 93338Salm unsigned _env[7]; 94338Salm unsigned _p; 95326Salm 962941Sbde /* 972941Sbde * _reg == 0 could be handled better using fnstcw/fldcw. 982941Sbde */ 992941Sbde __fnstenv(_env); 100338Salm _p = (_env[_reg] & _fld) >> _off; 101338Salm _env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld); 1022941Sbde __fldenv(_env); 103338Salm return _p; 104326Salm} 105326Salm 106326Salm#endif /* __GNUC__ */ 107326Salm 108326Salm/* 109326Salm * SysV/386 FP control interface 110326Salm */ 111326Salm#define fpgetround() ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF) 112326Salm#define fpsetround(m) __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF) 113326Salm#define fpgetprec() ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF) 114326Salm#define fpsetprec(m) __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF) 115326Salm#define fpgetmask() ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF) 116326Salm#define fpsetmask(m) __fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF) 117326Salm#define fpgetsticky() ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF) 118326Salm#define fpresetsticky(m) __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF) 119326Salm#define fpsetsticky(m) fpresetsticky(m) 120326Salm 121326Salm#endif /* !_FLOATINGPOINT_H_ */ 122