1/*- 2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#ifndef _FENV_H_ 30#define _FENV_H_ 31 32#include <sys/_types.h> 33 34#ifndef __fenv_static 35#define __fenv_static static 36#endif 37 38typedef __uint64_t fenv_t; 39typedef __uint64_t fexcept_t; 40 41/* Exception flags */ 42#define FE_INVALID 0x00000200 43#define FE_DIVBYZERO 0x00000040 44#define FE_OVERFLOW 0x00000100 45#define FE_UNDERFLOW 0x00000080 46#define FE_INEXACT 0x00000020 47#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | \ 48 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 49 50/* 51 * Rounding modes 52 * 53 * We can't just use the hardware bit values here, because that would 54 * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed. 55 */ 56#define FE_TONEAREST 0x0 57#define FE_TOWARDZERO 0x1 58#define FE_UPWARD 0x2 59#define FE_DOWNWARD 0x3 60#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ 61 FE_UPWARD | FE_TOWARDZERO) 62#define _ROUND_SHIFT 30 63 64__BEGIN_DECLS 65 66/* Default floating-point environment */ 67extern const fenv_t __fe_dfl_env; 68#define FE_DFL_ENV (&__fe_dfl_env) 69 70/* We need to be able to map status flag positions to mask flag positions */ 71#define _FPUSW_SHIFT 18 72#define _ENABLE_MASK (FE_ALL_EXCEPT << _FPUSW_SHIFT) 73 74#define __ldxfsr(__r) __asm __volatile("ldx %0, %%fsr" : : "m" (__r)) 75#define __stxfsr(__r) __asm __volatile("stx %%fsr, %0" : "=m" (*(__r))) 76 77__fenv_static __inline int 78feclearexcept(int __excepts) 79{ 80 fexcept_t __r; 81 82 __stxfsr(&__r); 83 __r &= ~__excepts; 84 __ldxfsr(__r); 85 return (0); 86} 87 88__fenv_static inline int 89fegetexceptflag(fexcept_t *__flagp, int __excepts) 90{ 91 fexcept_t __r; 92 93 __stxfsr(&__r); 94 *__flagp = __r & __excepts; 95 return (0); 96} 97 98__fenv_static inline int 99fesetexceptflag(const fexcept_t *__flagp, int __excepts) 100{ 101 fexcept_t __r; 102 103 __stxfsr(&__r); 104 __r &= ~__excepts; 105 __r |= *__flagp & __excepts; 106 __ldxfsr(__r); 107 return (0); 108} 109 110/* 111 * It seems to be worthwhile to inline this function even when the 112 * arguments are not compile-time constants. Perhaps this depends 113 * on the register window. 114 */ 115__fenv_static inline int 116feraiseexcept(int __excepts) 117{ 118 volatile double d; 119 120 /* 121 * With a compiler that supports the FENV_ACCESS pragma 122 * properly, simple expressions like '0.0 / 0.0' should 123 * be sufficient to generate traps. Unfortunately, we 124 * need to bring a volatile variable into the equation 125 * to prevent incorrect optimizations. 126 */ 127 if (__excepts & FE_INVALID) { 128 d = 0.0; 129 d = 0.0 / d; 130 } 131 if (__excepts & FE_DIVBYZERO) { 132 d = 0.0; 133 d = 1.0 / d; 134 } 135 if (__excepts & FE_OVERFLOW) { 136 d = 0x1.ffp1023; 137 d *= 2.0; 138 } 139 if (__excepts & FE_UNDERFLOW) { 140 d = 0x1p-1022; 141 d /= 0x1p1023; 142 } 143 if (__excepts & FE_INEXACT) { 144 d = 0x1p-1022; 145 d += 1.0; 146 } 147 return (0); 148} 149 150__fenv_static inline int 151fetestexcept(int __excepts) 152{ 153 fexcept_t __r; 154 155 __stxfsr(&__r); 156 return (__r & __excepts); 157} 158 159__fenv_static inline int 160fegetround(void) 161{ 162 fenv_t __r; 163 164 __stxfsr(&__r); 165 return ((__r >> _ROUND_SHIFT) & _ROUND_MASK); 166} 167 168__fenv_static inline int 169fesetround(int __round) 170{ 171 fenv_t __r; 172 173 if (__round & ~_ROUND_MASK) 174 return (-1); 175 __stxfsr(&__r); 176 __r &= ~(_ROUND_MASK << _ROUND_SHIFT); 177 __r |= __round << _ROUND_SHIFT; 178 __ldxfsr(__r); 179 return (0); 180} 181 182__fenv_static inline int 183fegetenv(fenv_t *__envp) 184{ 185 186 __stxfsr(__envp); 187 return (0); 188} 189 190__fenv_static inline int 191feholdexcept(fenv_t *__envp) 192{ 193 fenv_t __r; 194 195 __stxfsr(&__r); 196 *__envp = __r; 197 __r &= ~(FE_ALL_EXCEPT | _ENABLE_MASK); 198 __ldxfsr(__r); 199 return (0); 200} 201 202__fenv_static inline int 203fesetenv(const fenv_t *__envp) 204{ 205 206 __ldxfsr(*__envp); 207 return (0); 208} 209 210__fenv_static inline int 211feupdateenv(const fenv_t *__envp) 212{ 213 fexcept_t __r; 214 215 __stxfsr(&__r); 216 __ldxfsr(*__envp); 217 feraiseexcept(__r & FE_ALL_EXCEPT); 218 return (0); 219} 220 221#if __BSD_VISIBLE 222 223/* We currently provide no external definitions of the functions below. */ 224 225static inline int 226feenableexcept(int __mask) 227{ 228 fenv_t __old_r, __new_r; 229 230 __stxfsr(&__old_r); 231 __new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); 232 __ldxfsr(__new_r); 233 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); 234} 235 236static inline int 237fedisableexcept(int __mask) 238{ 239 fenv_t __old_r, __new_r; 240 241 __stxfsr(&__old_r); 242 __new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); 243 __ldxfsr(__new_r); 244 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); 245} 246 247static inline int 248fegetexcept(void) 249{ 250 fenv_t __r; 251 252 __stxfsr(&__r); 253 return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT); 254} 255 256#endif /* __BSD_VISIBLE */ 257 258__END_DECLS 259 260#endif /* !_FENV_H_ */ 261