1 /*- 2 * Copyright (c) 2003 Peter Wemm. 3 * Copyright (c) 1990 Andrew Moore, Talke Studio 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93 35 * $FreeBSD$ 36 */ 37 38 #ifndef _MACHINE_IEEEFP_H_ 39 #define _MACHINE_IEEEFP_H_ 40 41 /* 42 * IEEE floating point type, constant and function definitions. 43 * XXX: FP*FLD and FP*OFF are undocumented pollution. 44 */ 45 46 #ifndef _SYS_CDEFS_H_ 47 #error this file needs sys/cdefs.h as a prerequisite 48 #endif 49 50 /* 51 * Rounding modes. 52 */ 53 typedef enum { 54 FP_RN=0, /* round to nearest */ 55 FP_RM, /* round down towards minus infinity */ 56 FP_RP, /* round up towards plus infinity */ 57 FP_RZ /* truncate */ 58 } fp_rnd_t; 59 60 /* 61 * Precision (i.e., rounding precision) modes. 62 */ 63 typedef enum { 64 FP_PS=0, /* 24 bit (single-precision) */ 65 FP_PRS, /* reserved */ 66 FP_PD, /* 53 bit (double-precision) */ 67 FP_PE /* 64 bit (extended-precision) */ 68 } fp_prec_t; 69 70 #define fp_except_t int 71 72 /* 73 * Exception bit masks. 74 */ 75 #define FP_X_INV 0x01 /* invalid operation */ 76 #define FP_X_DNML 0x02 /* denormal */ 77 #define FP_X_DZ 0x04 /* zero divide */ 78 #define FP_X_OFL 0x08 /* overflow */ 79 #define FP_X_UFL 0x10 /* underflow */ 80 #define FP_X_IMP 0x20 /* (im)precision */ 81 #define FP_X_STK 0x40 /* stack fault */ 82 83 /* 84 * FPU control word bit-field masks. 85 */ 86 #define FP_MSKS_FLD 0x3f /* exception masks field */ 87 #define FP_PRC_FLD 0x300 /* precision control field */ 88 #define FP_RND_FLD 0xc00 /* rounding control field */ 89 90 /* 91 * FPU status word bit-field masks. 92 */ 93 #define FP_STKY_FLD 0x3f /* sticky flags field */ 94 95 /* 96 * FPU control word bit-field offsets (shift counts). 97 */ 98 #define FP_MSKS_OFF 0 /* exception masks offset */ 99 #define FP_PRC_OFF 8 /* precision control offset */ 100 #define FP_RND_OFF 10 /* rounding control offset */ 101 102 /* 103 * FPU status word bit-field offsets (shift counts). 104 */ 105 #define FP_STKY_OFF 0 /* sticky flags offset */ 106 107 #ifdef __GNUCLIKE_ASM 108 109 #define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr))) 110 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 111 #define __fnclex() __asm __volatile("fnclex") 112 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 113 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 114 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 115 116 /* 117 * Load the control word. Be careful not to trap if there is a currently 118 * unmasked exception (ones that will become freshly unmasked are not a 119 * problem). This case must be handled by a save/restore of the 120 * environment or even of the full x87 state. Accessing the environment 121 * is very inefficient, so only do it when necessary. 122 */ 123 static __inline void 124 __fnldcw(unsigned short _cw, unsigned short _newcw) 125 { 126 struct { 127 unsigned _cw; 128 unsigned _other[6]; 129 } _env; 130 unsigned short _sw; 131 132 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) { 133 __fnstsw(&_sw); 134 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) { 135 __fnstenv(&_env); 136 _env._cw = _newcw; 137 __fldenv(&_env); 138 return; 139 } 140 } 141 __fldcw(&_newcw); 142 } 143 144 static __inline fp_rnd_t 145 fpgetround(void) 146 { 147 unsigned short _cw; 148 149 __fnstcw(&_cw); 150 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF)); 151 } 152 153 static __inline fp_rnd_t 154 fpsetround(fp_rnd_t _m) 155 { 156 fp_rnd_t _p; 157 unsigned short _cw, _newcw; 158 159 __fnstcw(&_cw); 160 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF); 161 _newcw = _cw & ~FP_RND_FLD; 162 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD; 163 __fnldcw(_cw, _newcw); 164 return (_p); 165 } 166 167 static __inline fp_prec_t 168 fpgetprec(void) 169 { 170 unsigned short _cw; 171 172 __fnstcw(&_cw); 173 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF)); 174 } 175 176 static __inline fp_prec_t 177 fpsetprec(fp_prec_t _m) 178 { 179 fp_prec_t _p; 180 unsigned short _cw, _newcw; 181 182 __fnstcw(&_cw); 183 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF); 184 _newcw = _cw & ~FP_PRC_FLD; 185 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD; 186 __fnldcw(_cw, _newcw); 187 return (_p); 188 } 189 190 /* 191 * Get or set the exception mask. 192 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1 193 * means disable for x87 and SSE, but for fp*mask() it means enable. 194 */ 195 196 static __inline fp_except_t 197 fpgetmask(void) 198 { 199 unsigned short _cw; 200 201 __fnstcw(&_cw); 202 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF); 203 } 204 205 static __inline fp_except_t 206 fpsetmask(fp_except_t _m) 207 { 208 fp_except_t _p; 209 unsigned short _cw, _newcw; 210 211 __fnstcw(&_cw); 212 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF; 213 _newcw = _cw & ~FP_MSKS_FLD; 214 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD; 215 __fnldcw(_cw, _newcw); 216 return (_p); 217 } 218 219 static __inline fp_except_t 220 fpgetsticky(void) 221 { 222 unsigned _ex; 223 unsigned short _sw; 224 225 __fnstsw(&_sw); 226 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF; 227 return ((fp_except_t)_ex); 228 } 229 230 static __inline fp_except_t 231 fpresetsticky(fp_except_t _m) 232 { 233 struct { 234 unsigned _cw; 235 unsigned _sw; 236 unsigned _other[5]; 237 } _env; 238 fp_except_t _p; 239 240 _m &= FP_STKY_FLD >> FP_STKY_OFF; 241 _p = fpgetsticky(); 242 if ((_p & ~_m) == _p) 243 return (_p); 244 if ((_p & ~_m) == 0) { 245 __fnclex(); 246 return (_p); 247 } 248 __fnstenv(&_env); 249 _env._sw &= ~_m; 250 __fldenv(&_env); 251 return (_p); 252 } 253 254 #endif /* __GNUCLIKE_ASM */ 255 256 /* Suppress prototypes in the MI header. */ 257 #define _IEEEFP_INLINED_ 1 258 259 #endif /* !_MACHINE_IEEEFP_H_ */ 260