floatingpoint.h revision 621
1/*- 2 * Copyright (c) 1993 Andrew Moore, Talke Studio 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#) floatingpoint.h 1.0 (Berkeley) 9/23/93 34 * $Id$ 35 */ 36 37/* 38 * IEEE floating point structure and function definitions 39 */ 40 41#ifndef _FLOATINGPOINT_H_ 42#define _FLOATINGPOINT_H_ 43 44#include <sys/cdefs.h> 45#include <sys/ieeefp.h> 46 47#ifdef __GNUC__ 48 49#define fnstcw(addr) __asm("fnstcw %0" : "=m" (*addr) : "0" (*addr)) 50#define fnstsw(addr) __asm("fnstsw %0" : "=m" (*addr) : "0" (*addr)) 51#define fnstenv(addr) __asm("fnstenv %0" : "=m" (*addr) : "0" (*addr)) 52#define fldenv(addr) __asm("fldenv %0" : : "m" (*addr)) 53 54#ifdef __i386__ 55 56/* 57 * return the contents of a FP register 58 */ 59static __inline__ int 60__fpgetreg(int _reg) 61{ 62 unsigned short _mem; 63 64 switch(_reg) { 65 default: 66 fnstcw(&_mem); 67 break; 68 case FP_STKY_REG: 69 fnstsw(&_mem); 70 break; 71 } 72 return _mem; 73} 74 75/* 76 * set a FP mode; return previous mode 77 */ 78static __inline__ int 79__fpsetreg(int _m, int _reg, int _fld, int _off) 80{ 81 unsigned _env[7]; 82 unsigned _p; 83 84 fnstenv(_env); 85 _p = (_env[_reg] & _fld) >> _off; 86 _env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld); 87 fldenv(_env); 88 return _p; 89} 90 91#endif /* __i386__ */ 92 93#endif /* __GNUC__ */ 94 95/* 96 * SysV/386 FP control interface 97 */ 98#define fpgetround() ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF) 99#define fpsetround(m) __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF) 100#define fpgetprec() ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF) 101#define fpsetprec(m) __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF) 102#define fpgetmask() ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF) 103#define fpsetmask(m) __fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF) 104#define fpgetsticky() ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF) 105#define fpresetsticky(m) __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF) 106#define fpsetsticky(m) fpresetsticky(m) 107 108#endif /* !_FLOATINGPOINT_H_ */ 109