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/amd64/fenv.h,v 1.5 2005/03/16 22:34:14 das Exp $ 27 */ 28 29 #ifndef _FENV_H_ 30 #define _FENV_H_ 31 32 #include <sys/cdefs.h> 33 #include <sys/_types.h> 34 35 typedef struct { 36 struct { 37 __uint32_t __control; 38 __uint32_t __status; 39 __uint32_t __tag; 40 char __other[16]; 41 } __x87; 42 __uint32_t __mxcsr; 43 } fenv_t; 44 45 typedef __uint16_t fexcept_t; 46 47 /* Exception flags */ 48 #define FE_INVALID 0x01 49 #define FE_DENORMAL 0x02 50 #define FE_DIVBYZERO 0x04 51 #define FE_OVERFLOW 0x08 52 #define FE_UNDERFLOW 0x10 53 #define FE_INEXACT 0x20 54 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \ 55 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 56 57 /* Rounding modes */ 58 #define FE_TONEAREST 0x0000 59 #define FE_DOWNWARD 0x0400 60 #define FE_UPWARD 0x0800 61 #define FE_TOWARDZERO 0x0c00 62 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ 63 FE_UPWARD | FE_TOWARDZERO) 64 65 /* 66 * As compared to the x87 control word, the SSE unit's control word 67 * has the rounding control bits offset by 3 and the exception mask 68 * bits offset by 7. 69 */ 70 #define _SSE_ROUND_SHIFT 3 71 #define _SSE_EMASK_SHIFT 7 72 73 __BEGIN_DECLS 74 75 /* Default floating-point environment */ 76 extern const fenv_t __fe_dfl_env; 77 #define FE_DFL_ENV (&__fe_dfl_env) 78 79 #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw)) 80 #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env)) 81 #define __fnclex() __asm __volatile("fnclex") 82 #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env))) 83 #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw))) 84 #define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw))) 85 #define __fwait() __asm __volatile("fwait") 86 #define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr)) 87 #define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr))) 88 89 static __inline int 90 feclearexcept(int __excepts) 91 { 92 fenv_t __env; 93 94 if (__excepts == FE_ALL_EXCEPT) { 95 __fnclex(); 96 } else { 97 __fnstenv(&__env.__x87); 98 __env.__x87.__status &= ~__excepts; 99 __fldenv(__env.__x87); 100 } 101 __stmxcsr(&__env.__mxcsr); 102 __env.__mxcsr &= ~__excepts; 103 __ldmxcsr(__env.__mxcsr); 104 return (0); 105 } 106 107 static __inline int 108 fegetexceptflag(fexcept_t *__flagp, int __excepts) 109 { 110 int __mxcsr, __status; 111 112 __stmxcsr(&__mxcsr); 113 __fnstsw(&__status); 114 *__flagp = (__mxcsr | __status) & __excepts; 115 return (0); 116 } 117 118 int fesetexceptflag(const fexcept_t *__flagp, int __excepts); 119 int feraiseexcept(int __excepts); 120 121 static __inline int 122 fetestexcept(int __excepts) 123 { 124 int __mxcsr, __status; 125 126 __stmxcsr(&__mxcsr); 127 __fnstsw(&__status); 128 return ((__status | __mxcsr) & __excepts); 129 } 130 131 static __inline int 132 fegetround(void) 133 { 134 int __control; 135 136 /* 137 * We assume that the x87 and the SSE unit agree on the 138 * rounding mode. Reading the control word on the x87 turns 139 * out to be about 5 times faster than reading it on the SSE 140 * unit on an Opteron 244. 141 */ 142 __fnstcw(&__control); 143 return (__control & _ROUND_MASK); 144 } 145 146 static __inline int 147 fesetround(int __round) 148 { 149 int __mxcsr, __control; 150 151 if (__round & ~_ROUND_MASK) 152 return (-1); 153 154 __fnstcw(&__control); 155 __control &= ~_ROUND_MASK; 156 __control |= __round; 157 __fldcw(__control); 158 159 __stmxcsr(&__mxcsr); 160 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT); 161 __mxcsr |= __round << _SSE_ROUND_SHIFT; 162 __ldmxcsr(__mxcsr); 163 164 return (0); 165 } 166 167 int fegetenv(fenv_t *__envp); 168 int feholdexcept(fenv_t *__envp); 169 170 static __inline int 171 fesetenv(const fenv_t *__envp) 172 { 173 174 __fldenv(__envp->__x87); 175 __ldmxcsr(__envp->__mxcsr); 176 return (0); 177 } 178 179 int feupdateenv(const fenv_t *__envp); 180 181 #if __BSD_VISIBLE 182 183 int feenableexcept(int __mask); 184 int fedisableexcept(int __mask); 185 186 static __inline int 187 fegetexcept(void) 188 { 189 int __control; 190 191 /* 192 * We assume that the masks for the x87 and the SSE unit are 193 * the same. 194 */ 195 __fnstcw(&__control); 196 return (~__control & FE_ALL_EXCEPT); 197 } 198 199 #endif /* __BSD_VISIBLE */ 200 201 __END_DECLS 202 203 #endif /* !_FENV_H_ */ 204
