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 <stdint.h> 33 #include <sys/cdefs.h> 34 #include <sys/types.h> 35 36 #ifndef __fenv_static 37 #define __fenv_static static 38 #endif 39 40 typedef uint64_t fenv_t; 41 typedef uint64_t fexcept_t; 42 43 /* Exception flags */ 44 #define FE_INVALID 0x00000001 45 #define FE_DIVBYZERO 0x00000002 46 #define FE_OVERFLOW 0x00000004 47 #define FE_UNDERFLOW 0x00000008 48 #define FE_INEXACT 0x00000010 49 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | \ 50 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 51 52 /* 53 * Rounding modes 54 * 55 * We can't just use the hardware bit values here, because that would 56 * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed. 57 */ 58 #define FE_TONEAREST 0x0 59 #define FE_UPWARD 0x1 60 #define FE_DOWNWARD 0x2 61 #define FE_TOWARDZERO 0x3 62 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ 63 FE_UPWARD | FE_TOWARDZERO) 64 #define _ROUND_SHIFT 22 65 66 __BEGIN_DECLS 67 68 /* Default floating-point environment */ 69 extern const fenv_t __fe_dfl_env; 70 #define FE_DFL_ENV (&__fe_dfl_env) 71 72 /* We need to be able to map status flag positions to mask flag positions */ 73 #define _FPUSW_SHIFT 8 74 #define _ENABLE_MASK (FE_ALL_EXCEPT << _FPUSW_SHIFT) 75 76 #define __mrs_fpcr(__r) __asm __volatile("mrs %0, fpcr" : "=r" (__r)) 77 #define __msr_fpcr(__r) __asm __volatile("msr fpcr, %0" : : "r" (__r)) 78 79 #define __mrs_fpsr(__r) __asm __volatile("mrs %0, fpsr" : "=r" (__r)) 80 #define __msr_fpsr(__r) __asm __volatile("msr fpsr, %0" : : "r" (__r)) 81 82 __fenv_static __inline int 83 feclearexcept(int __excepts) 84 { 85 fexcept_t __r; 86 87 __mrs_fpsr(__r); 88 __r &= ~__excepts; 89 __msr_fpsr(__r); 90 return (0); 91 } 92 93 __fenv_static inline int 94 fegetexceptflag(fexcept_t *__flagp, int __excepts) 95 { 96 fexcept_t __r; 97 98 __mrs_fpsr(__r); 99 *__flagp = __r & __excepts; 100 return (0); 101 } 102 103 __fenv_static inline int 104 fesetexceptflag(const fexcept_t *__flagp, int __excepts) 105 { 106 fexcept_t __r; 107 108 __mrs_fpsr(__r); 109 __r &= ~__excepts; 110 __r |= *__flagp & __excepts; 111 __msr_fpsr(__r); 112 return (0); 113 } 114 115 __fenv_static inline int 116 feraiseexcept(int __excepts) 117 { 118 fexcept_t __r; 119 120 __mrs_fpsr(__r); 121 __r |= __excepts; 122 __msr_fpsr(__r); 123 return (0); 124 } 125 126 __fenv_static inline int 127 fetestexcept(int __excepts) 128 { 129 fexcept_t __r; 130 131 __mrs_fpsr(__r); 132 return (__r & __excepts); 133 } 134 135 __fenv_static inline int 136 fegetround(void) 137 { 138 fenv_t __r; 139 140 __mrs_fpcr(__r); 141 return ((__r >> _ROUND_SHIFT) & _ROUND_MASK); 142 } 143 144 __fenv_static inline int 145 fesetround(int __round) 146 { 147 fenv_t __r; 148 149 if (__round & ~_ROUND_MASK) 150 return (-1); 151 __mrs_fpcr(__r); 152 __r &= ~(_ROUND_MASK << _ROUND_SHIFT); 153 __r |= __round << _ROUND_SHIFT; 154 __msr_fpcr(__r); 155 return (0); 156 } 157 158 __fenv_static inline int 159 fegetenv(fenv_t *__envp) 160 { 161 fenv_t __r; 162 163 __mrs_fpcr(__r); 164 *__envp = __r & _ENABLE_MASK; 165 166 __mrs_fpsr(__r); 167 *__envp |= __r & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT)); 168 169 return (0); 170 } 171 172 __fenv_static inline int 173 feholdexcept(fenv_t *__envp) 174 { 175 fenv_t __r; 176 177 __mrs_fpcr(__r); 178 *__envp = __r & _ENABLE_MASK; 179 __r &= ~(_ENABLE_MASK); 180 __msr_fpcr(__r); 181 182 __mrs_fpsr(__r); 183 *__envp |= __r & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT)); 184 __r &= ~(_ENABLE_MASK); 185 __msr_fpsr(__r); 186 return (0); 187 } 188 189 __fenv_static inline int 190 fesetenv(const fenv_t *__envp) 191 { 192 193 __msr_fpcr((*__envp) & _ENABLE_MASK); 194 __msr_fpsr((*__envp) & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT))); 195 return (0); 196 } 197 198 __fenv_static inline int 199 feupdateenv(const fenv_t *__envp) 200 { 201 fexcept_t __r; 202 203 __mrs_fpsr(__r); 204 fesetenv(__envp); 205 feraiseexcept(__r & FE_ALL_EXCEPT); 206 return (0); 207 } 208 209 #if __BSD_VISIBLE 210 211 /* We currently provide no external definitions of the functions below. */ 212 213 static inline int 214 feenableexcept(int __mask) 215 { 216 fenv_t __old_r, __new_r; 217 218 __mrs_fpcr(__old_r); 219 __new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); 220 __msr_fpcr(__new_r); 221 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); 222 } 223 224 static inline int 225 fedisableexcept(int __mask) 226 { 227 fenv_t __old_r, __new_r; 228 229 __mrs_fpcr(__old_r); 230 __new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); 231 __msr_fpcr(__new_r); 232 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); 233 } 234 235 static inline int 236 fegetexcept(void) 237 { 238 fenv_t __r; 239 240 __mrs_fpcr(__r); 241 return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT); 242 } 243 244 #endif /* __BSD_VISIBLE */ 245 246 __END_DECLS 247 248 #endif /* !_FENV_H_ */ 249