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/i387/fenv.h,v 1.4 2005/03/17 22:21:46 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 /* 36 * To preserve binary compatibility with FreeBSD 5.3, we pack the 37 * mxcsr into some reserved fields, rather than changing sizeof(fenv_t). 38 */ 39 typedef struct { 40 __uint16_t __control; 41 __uint16_t __mxcsr_hi; 42 __uint16_t __status; 43 __uint16_t __mxcsr_lo; 44 __uint32_t __tag; 45 char __other[16]; 46 } fenv_t; 47 48 #define __get_mxcsr(env) (((env).__mxcsr_hi << 16) | \ 49 ((env).__mxcsr_lo)) 50 #define __set_mxcsr(env, x) do { \ 51 (env).__mxcsr_hi = (__uint32_t)(x) >> 16; \ 52 (env).__mxcsr_lo = (__uint16_t)(x); \ 53 } while (0) 54 55 typedef __uint16_t fexcept_t; 56 57 /* Exception flags */ 58 #define FE_INVALID 0x01 59 #define FE_DENORMAL 0x02 60 #define FE_DIVBYZERO 0x04 61 #define FE_OVERFLOW 0x08 62 #define FE_UNDERFLOW 0x10 63 #define FE_INEXACT 0x20 64 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \ 65 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) 66 67 /* Rounding modes */ 68 #define FE_TONEAREST 0x0000 69 #define FE_DOWNWARD 0x0400 70 #define FE_UPWARD 0x0800 71 #define FE_TOWARDZERO 0x0c00 72 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ 73 FE_UPWARD | FE_TOWARDZERO) 74 75 /* 76 * As compared to the x87 control word, the SSE unit's control word 77 * has the rounding control bits offset by 3 and the exception mask 78 * bits offset by 7. 79 */ 80 #define _SSE_ROUND_SHIFT 3 81 #define _SSE_EMASK_SHIFT 7 82 83 /* After testing for SSE support once, we cache the result in __has_sse. */ 84 enum __sse_support { __SSE_YES, __SSE_NO, __SSE_UNK }; 85 extern enum __sse_support __has_sse; 86 int __test_sse(void); 87 #ifdef __SSE__ 88 #define __HAS_SSE() 1 89 #else 90 #define __HAS_SSE() (__has_sse == __SSE_YES || \ 91 (__has_sse == __SSE_UNK && __test_sse())) 92 #endif 93 94 __BEGIN_DECLS 95 96 /* Default floating-point environment */ 97 extern const fenv_t __fe_dfl_env; 98 #define FE_DFL_ENV (&__fe_dfl_env) 99 100 #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw)) 101 #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env)) 102 #define __fnclex() __asm __volatile("fnclex") 103 #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env))) 104 #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw))) 105 #define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw))) 106 #define __fwait() __asm __volatile("fwait") 107 #define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr)) 108 #define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr))) 109 110 static __inline int 111 feclearexcept(int __excepts) 112 { 113 fenv_t __env; 114 int __mxcsr; 115 116 if (__excepts == FE_ALL_EXCEPT) { 117 __fnclex(); 118 } else { 119 __fnstenv(&__env); 120 __env.__status &= ~__excepts; 121 __fldenv(__env); 122 } 123 if (__HAS_SSE()) { 124 __stmxcsr(&__mxcsr); 125 __mxcsr &= ~__excepts; 126 __ldmxcsr(__mxcsr); 127 } 128 return (0); 129 } 130 131 static __inline int 132 fegetexceptflag(fexcept_t *__flagp, int __excepts) 133 { 134 int __mxcsr, __status; 135 136 __fnstsw(&__status); 137 if (__HAS_SSE()) 138 __stmxcsr(&__mxcsr); 139 else 140 __mxcsr = 0; 141 *__flagp = (__mxcsr | __status) & __excepts; 142 return (0); 143 } 144 145 int fesetexceptflag(const fexcept_t *__flagp, int __excepts); 146 int feraiseexcept(int __excepts); 147 148 static __inline int 149 fetestexcept(int __excepts) 150 { 151 int __mxcsr, __status; 152 153 __fnstsw(&__status); 154 if (__HAS_SSE()) 155 __stmxcsr(&__mxcsr); 156 else 157 __mxcsr = 0; 158 return ((__status | __mxcsr) & __excepts); 159 } 160 161 static __inline int 162 fegetround(void) 163 { 164 int __control; 165 166 /* 167 * We assume that the x87 and the SSE unit agree on the 168 * rounding mode. Reading the control word on the x87 turns 169 * out to be about 5 times faster than reading it on the SSE 170 * unit on an Opteron 244. 171 */ 172 __fnstcw(&__control); 173 return (__control & _ROUND_MASK); 174 } 175 176 static __inline int 177 fesetround(int __round) 178 { 179 int __mxcsr, __control; 180 181 if (__round & ~_ROUND_MASK) 182 return (-1); 183 184 __fnstcw(&__control); 185 __control &= ~_ROUND_MASK; 186 __control |= __round; 187 __fldcw(__control); 188 189 if (__HAS_SSE()) { 190 __stmxcsr(&__mxcsr); 191 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT); 192 __mxcsr |= __round << _SSE_ROUND_SHIFT; 193 __ldmxcsr(__mxcsr); 194 } 195 196 return (0); 197 } 198 199 int fegetenv(fenv_t *__envp); 200 int feholdexcept(fenv_t *__envp); 201 202 static __inline int 203 fesetenv(const fenv_t *__envp) 204 { 205 fenv_t __env = *__envp; 206 int __mxcsr; 207 208 __mxcsr = __get_mxcsr(__env); 209 __set_mxcsr(__env, 0xffffffff); 210 __fldenv(__env); 211 if (__HAS_SSE()) 212 __ldmxcsr(__mxcsr); 213 return (0); 214 } 215 216 int feupdateenv(const fenv_t *__envp); 217 218 #if __BSD_VISIBLE 219 220 int feenableexcept(int __mask); 221 int fedisableexcept(int __mask); 222 223 static __inline int 224 fegetexcept(void) 225 { 226 int __control; 227 228 /* 229 * We assume that the masks for the x87 and the SSE unit are 230 * the same. 231 */ 232 __fnstcw(&__control); 233 return (~__control & FE_ALL_EXCEPT); 234 } 235 236 #endif /* __BSD_VISIBLE */ 237 238 __END_DECLS 239 240 #endif /* !_FENV_H_ */ 241
