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 * $FreeBSD$ 35 */ 36 37 #ifndef _FLOATINGPOINT_H_ 38 #define _FLOATINGPOINT_H_ 39 40 /* 41 * IEEE floating point structure and function definitions 42 */ 43 44 /*- 45 * XXX the following undocumented pollution is exported: 46 * fpsetsticky(). 47 * FP*FLD, FP*OFF and FP*REG from <machine/ieeefp.h> 48 */ 49 50 #include <sys/cdefs.h> 51 #include <machine/ieeefp.h> 52 53 #ifdef __GNUC__ 54 55 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 56 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 57 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 58 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 59 60 /* 61 * return the contents of a FP register 62 */ 63 static __inline__ int 64 __fpgetreg(int _reg) 65 { 66 unsigned short _mem; 67 68 /*- 69 * This is more efficient than it looks. The switch gets optimized 70 * away if _reg is constant. 71 * 72 * The default case only supports _reg == 0. We could handle more 73 * registers (e.g., tags) using fnstenv, but the interface doesn't 74 * support more. 75 */ 76 switch(_reg) { 77 default: 78 __fnstcw(&_mem); 79 break; 80 case FP_STKY_REG: 81 __fnstsw(&_mem); 82 break; 83 } 84 return _mem; 85 } 86 87 /* 88 * set a FP mode; return previous mode 89 */ 90 static __inline__ int 91 __fpsetreg(int _m, int _reg, int _fld, int _off) 92 { 93 unsigned _env[7]; 94 unsigned _p; 95 96 /* 97 * _reg == 0 could be handled better using fnstcw/fldcw. 98 */ 99 __fnstenv(_env); 100 _p = (_env[_reg] & _fld) >> _off; 101 _env[_reg] = (_env[_reg] & ~_fld) | (_m << _off & _fld); 102 __fldenv(_env); 103 return _p; 104 } 105 106 #endif /* __GNUC__ */ 107 108 /* 109 * SysV/386 FP control interface 110 */ 111 #define fpgetround() ((fp_rnd_t) ((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF)) 112 #define fpsetround(m) ((fp_rnd_t) __fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF)) 113 #define fpgetprec() ((fp_prec_t) ((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF)) 114 #define fpsetprec(m) ((fp_prec_t) __fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF)) 115 #define fpgetmask() ((fp_except_t) ((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF)) 116 #define fpsetmask(m) ((fp_except_t) (__fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF))) 117 #define fpgetsticky() ((fp_except_t) ((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF)) 118 #define fpresetsticky(m) ((fp_except_t) __fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF)) 119 #define fpsetsticky(m) fpresetsticky(m) 120 121 #endif /* !_FLOATINGPOINT_H_ */ 122