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 * Deprecated historical FPU control interface 43 * 44 * IEEE floating point type, constant and function definitions. 45 * XXX: FP*FLD and FP*OFF are undocumented pollution. 46 */ 47 48 /* VBS 49 50 #ifndef _SYS_CDEFS_H_ 51 #error this file needs sys/cdefs.h as a prerequisite 52 #endif 53 54 */ 55 56 /* 57 * Rounding modes. 58 */ 59 typedef enum { 60 FP_RN=0, /* round to nearest */ 61 FP_RM, /* round down towards minus infinity */ 62 FP_RP, /* round up towards plus infinity */ 63 FP_RZ /* truncate */ 64 } fp_rnd_t; 65 66 /* 67 * Precision (i.e., rounding precision) modes. 68 */ 69 typedef enum { 70 FP_PS=0, /* 24 bit (single-precision) */ 71 FP_PRS, /* reserved */ 72 FP_PD, /* 53 bit (double-precision) */ 73 FP_PE /* 64 bit (extended-precision) */ 74 } fp_prec_t; 75 76 #define fp_except_t int 77 78 /* 79 * Exception bit masks. 80 */ 81 #define FP_X_INV 0x01 /* invalid operation */ 82 #define FP_X_DNML 0x02 /* denormal */ 83 #define FP_X_DZ 0x04 /* zero divide */ 84 #define FP_X_OFL 0x08 /* overflow */ 85 #define FP_X_UFL 0x10 /* underflow */ 86 #define FP_X_IMP 0x20 /* (im)precision */ 87 #define FP_X_STK 0x40 /* stack fault */ 88 89 /* 90 * FPU control word bit-field masks. 91 */ 92 #define FP_MSKS_FLD 0x3f /* exception masks field */ 93 #define FP_PRC_FLD 0x300 /* precision control field */ 94 #define FP_RND_FLD 0xc00 /* rounding control field */ 95 96 /* 97 * FPU status word bit-field masks. 98 */ 99 #define FP_STKY_FLD 0x3f /* sticky flags field */ 100 101 /* 102 * FPU control word bit-field offsets (shift counts). 103 */ 104 #define FP_MSKS_OFF 0 /* exception masks offset */ 105 #define FP_PRC_OFF 8 /* precision control offset */ 106 #define FP_RND_OFF 10 /* rounding control offset */ 107 108 /* 109 * FPU status word bit-field offsets (shift counts). 110 */ 111 #define FP_STKY_OFF 0 /* sticky flags offset */ 112 113 //VBS 114 //#ifdef __GNUCLIKE_ASM 115 116 #define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr))) 117 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 118 #define __fnclex() __asm __volatile("fnclex") 119 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 120 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 121 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 122 123 /* 124 * Load the control word. Be careful not to trap if there is a currently 125 * unmasked exception (ones that will become freshly unmasked are not a 126 * problem). This case must be handled by a save/restore of the 127 * environment or even of the full x87 state. Accessing the environment 128 * is very inefficient, so only do it when necessary. 129 */ 130 static __inline void 131 __fnldcw(unsigned short _cw, unsigned short _newcw) 132 { 133 struct { 134 unsigned _cw; 135 unsigned _other[6]; 136 } _env; 137 unsigned short _sw; 138 139 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) { 140 __fnstsw(&_sw); 141 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) { 142 __fnstenv(&_env); 143 _env._cw = _newcw; 144 __fldenv(&_env); 145 return; 146 } 147 } 148 __fldcw(&_newcw); 149 } 150 151 static __inline fp_rnd_t 152 fpgetround(void) 153 { 154 unsigned short _cw; 155 156 __fnstcw(&_cw); 157 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF)); 158 } 159 160 static __inline fp_rnd_t 161 fpsetround(fp_rnd_t _m) 162 { 163 fp_rnd_t _p; 164 unsigned short _cw, _newcw; 165 166 __fnstcw(&_cw); 167 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF); 168 _newcw = _cw & ~FP_RND_FLD; 169 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD; 170 __fnldcw(_cw, _newcw); 171 return (_p); 172 } 173 174 //static __inline fp_prec_t 175 OLM_DLLEXPORT fp_prec_t 176 fpgetprec(void) 177 { 178 unsigned short _cw; 179 180 __fnstcw(&_cw); 181 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF)); 182 } 183 184 //static __inline fp_prec_t 185 OLM_DLLEXPORT fp_prec_t 186 fpsetprec(fp_prec_t _m) 187 { 188 fp_prec_t _p; 189 unsigned short _cw, _newcw; 190 191 __fnstcw(&_cw); 192 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF); 193 _newcw = _cw & ~FP_PRC_FLD; 194 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD; 195 __fnldcw(_cw, _newcw); 196 return (_p); 197 } 198 199 /* 200 * Get or set the exception mask. 201 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1 202 * means disable for x87 and SSE, but for fp*mask() it means enable. 203 */ 204 205 static __inline fp_except_t 206 fpgetmask(void) 207 { 208 unsigned short _cw; 209 210 __fnstcw(&_cw); 211 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF); 212 } 213 214 static __inline fp_except_t 215 fpsetmask(fp_except_t _m) 216 { 217 fp_except_t _p; 218 unsigned short _cw, _newcw; 219 220 __fnstcw(&_cw); 221 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF; 222 _newcw = _cw & ~FP_MSKS_FLD; 223 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD; 224 __fnldcw(_cw, _newcw); 225 return (_p); 226 } 227 228 static __inline fp_except_t 229 fpgetsticky(void) 230 { 231 unsigned _ex; 232 unsigned short _sw; 233 234 __fnstsw(&_sw); 235 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF; 236 return ((fp_except_t)_ex); 237 } 238 239 static __inline fp_except_t 240 fpresetsticky(fp_except_t _m) 241 { 242 struct { 243 unsigned _cw; 244 unsigned _sw; 245 unsigned _other[5]; 246 } _env; 247 fp_except_t _p; 248 249 _m &= FP_STKY_FLD >> FP_STKY_OFF; 250 _p = fpgetsticky(); 251 if ((_p & ~_m) == _p) 252 return (_p); 253 if ((_p & ~_m) == 0) { 254 __fnclex(); 255 return (_p); 256 } 257 __fnstenv(&_env); 258 _env._sw &= ~_m; 259 __fldenv(&_env); 260 return (_p); 261 } 262 263 //#endif /* __GNUCLIKE_ASM */ 264 265 #endif /* !_MACHINE_IEEEFP_H_ */ 266