1 /*- 2 * Copyright (c) 2004-2005 David Schultz <das (at) 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: src/lib/msun/alpha/fenv.h,v 1.3 2005/03/16 19:03:44 das Exp $ 27 */ 28 29 #ifndef _FENV_H_ 30 #define _FENV_H_ 31 32 #include <sys/_types.h> 33 34 typedef __uint64_t fenv_t; 35 typedef __uint16_t fexcept_t; 36 37 /* Exception flags */ 38 #define FE_INVALID 0x02 39 #define FE_DIVBYZERO 0x04 40 #define FE_OVERFLOW 0x08 41 #define FE_UNDERFLOW 0x10 42 #define FE_INEXACT 0x20 43 #define FE_INTOVF 0x40 /* not maskable */ 44 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INTOVF | \ 45 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 46 47 /* Rounding modes */ 48 #define FE_TOWARDZERO 0x00 49 #define FE_DOWNWARD 0x01 50 #define FE_TONEAREST 0x02 51 #define FE_UPWARD 0x03 52 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ 53 FE_UPWARD | FE_TOWARDZERO) 54 #define _ROUND_SHIFT 58 55 56 #define _FPUSW_SHIFT 51 57 58 #define __excb() __asm __volatile("excb") 59 #define __mf_fpcr(__cw) __asm __volatile("mf_fpcr %0" : "=f" (*(__cw))) 60 #define __mt_fpcr(__cw) __asm __volatile("mt_fpcr %0" : : "f" (__cw)) 61 62 union __fpcr { 63 double __d; 64 fenv_t __bits; 65 }; 66 67 __BEGIN_DECLS 68 69 /* Default floating-point environment */ 70 extern const fenv_t __fe_dfl_env; 71 #define FE_DFL_ENV (&__fe_dfl_env) 72 73 static __inline int 74 feclearexcept(int __excepts) 75 { 76 union __fpcr __r; 77 78 __excb(); 79 __mf_fpcr(&__r.__d); 80 __r.__bits &= ~((fenv_t)__excepts << _FPUSW_SHIFT); 81 __mt_fpcr(__r.__d); 82 __excb(); 83 return (0); 84 } 85 86 static __inline int 87 fegetexceptflag(fexcept_t *__flagp, int __excepts) 88 { 89 union __fpcr __r; 90 91 __excb(); 92 __mf_fpcr(&__r.__d); 93 __excb(); 94 *__flagp = (__r.__bits >> _FPUSW_SHIFT) & __excepts; 95 return (0); 96 } 97 98 static __inline int 99 fesetexceptflag(const fexcept_t *__flagp, int __excepts) 100 { 101 union __fpcr __r; 102 fenv_t __xflag, __xexcepts; 103 104 __xflag = (fenv_t)*__flagp << _FPUSW_SHIFT; 105 __xexcepts = (fenv_t)__excepts << _FPUSW_SHIFT; 106 __excb(); 107 __mf_fpcr(&__r.__d); 108 __r.__bits &= ~__xexcepts; 109 __r.__bits |= __xflag & __xexcepts; 110 __mt_fpcr(__r.__d); 111 __excb(); 112 return (0); 113 } 114 115 static __inline int 116 feraiseexcept(int __excepts) 117 { 118 119 /* 120 * XXX Generating exceptions this way does not actually invoke 121 * a userland trap handler when enabled, but neither do 122 * arithmetic operations as far as I can tell. Perhaps there 123 * are more bugs in the kernel trap handler. 124 */ 125 fexcept_t __ex = __excepts; 126 fesetexceptflag(&__ex, __excepts); 127 return (0); 128 } 129 130 static __inline int 131 fetestexcept(int __excepts) 132 { 133 union __fpcr __r; 134 135 __excb(); 136 __mf_fpcr(&__r.__d); 137 __excb(); 138 return ((__r.__bits >> _FPUSW_SHIFT) & __excepts); 139 } 140 141 static __inline int 142 fegetround(void) 143 { 144 union __fpcr __r; 145 146 /* 147 * No exception barriers should be required here if we assume 148 * that only fesetround() can change the rounding mode. 149 */ 150 __mf_fpcr(&__r.__d); 151 return ((int)(__r.__bits >> _ROUND_SHIFT) & _ROUND_MASK); 152 } 153 154 static __inline int 155 fesetround(int __round) 156 { 157 union __fpcr __r; 158 159 if (__round & ~_ROUND_MASK) 160 return (-1); 161 __excb(); 162 __mf_fpcr(&__r.__d); 163 __r.__bits &= ~((fenv_t)_ROUND_MASK << _ROUND_SHIFT); 164 __r.__bits |= (fenv_t)__round << _ROUND_SHIFT; 165 __mt_fpcr(__r.__d); 166 __excb(); 167 return (0); 168 } 169 170 int fegetenv(fenv_t *__envp); 171 int feholdexcept(fenv_t *__envp); 172 int fesetenv(const fenv_t *__envp); 173 int feupdateenv(const fenv_t *__envp); 174 175 #if __BSD_VISIBLE 176 177 int feenableexcept(int __mask); 178 int fedisableexcept(int __mask); 179 int fegetexcept(void); 180 181 #endif /* __BSD_VISIBLE */ 182 183 __END_DECLS 184 185 #endif /* !_FENV_H_ */ 186
