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,SSE}*FLD and {FP,SSE}*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 * SSE mxcsr register bit-field masks. 97 */ 98 #define SSE_STKY_FLD 0x3f /* exception flags */ 99 #define SSE_DAZ_FLD 0x40 /* Denormals are zero */ 100 #define SSE_MSKS_FLD 0x1f80 /* exception masks field */ 101 #define SSE_RND_FLD 0x6000 /* rounding control */ 102 #define SSE_FZ_FLD 0x8000 /* flush to zero on underflow */ 103 104 /* 105 * FPU control word bit-field offsets (shift counts). 106 */ 107 #define FP_MSKS_OFF 0 /* exception masks offset */ 108 #define FP_PRC_OFF 8 /* precision control offset */ 109 #define FP_RND_OFF 10 /* rounding control offset */ 110 111 /* 112 * FPU status word bit-field offsets (shift counts). 113 */ 114 #define FP_STKY_OFF 0 /* sticky flags offset */ 115 116 /* 117 * SSE mxcsr register bit-field offsets (shift counts). 118 */ 119 #define SSE_STKY_OFF 0 /* exception flags offset */ 120 #define SSE_DAZ_OFF 6 /* DAZ exception mask offset */ 121 #define SSE_MSKS_OFF 7 /* other exception masks offset */ 122 #define SSE_RND_OFF 13 /* rounding control offset */ 123 #define SSE_FZ_OFF 15 /* flush to zero offset */ 124 125 #ifdef __GNUCLIKE_ASM 126 127 #define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr))) 128 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 129 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 130 #define __ldmxcsr(addr) __asm __volatile("ldmxcsr %0" : : "m" (*(addr))) 131 #define __stmxcsr(addr) __asm __volatile("stmxcsr %0" : "=m" (*(addr))) 132 133 /* 134 * General notes about conflicting SSE vs FP status bits. 135 * This code assumes that software will not fiddle with the control 136 * bits of the SSE and x87 in such a way to get them out of sync and 137 * still expect this to work. Break this at your peril. 138 * Because I based this on the i386 port, the x87 state is used for 139 * the fpget*() functions, and is shadowed into the SSE state for 140 * the fpset*() functions. For dual source fpget*() functions, I 141 * merge the two together. I think. 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 _mxcsr; 158 unsigned short _cw; 159 160 __fnstcw(&_cw); 161 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF); 162 _cw &= ~FP_RND_FLD; 163 _cw |= (_m << FP_RND_OFF) & FP_RND_FLD; 164 __fldcw(&_cw); 165 __stmxcsr(&_mxcsr); 166 _mxcsr &= ~SSE_RND_FLD; 167 _mxcsr |= (_m << SSE_RND_OFF) & SSE_RND_FLD; 168 __ldmxcsr(&_mxcsr); 169 return (_p); 170 } 171 172 /* 173 * Get or set the rounding precision for x87 arithmetic operations. 174 * There is no equivalent SSE mode or control. 175 */ 176 177 static __inline fp_prec_t 178 __fpgetprec(void) 179 { 180 unsigned short _cw; 181 182 __fnstcw(&_cw); 183 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF)); 184 } 185 186 static __inline fp_prec_t 187 __fpsetprec(fp_prec_t _m) 188 { 189 fp_prec_t _p; 190 unsigned short _cw; 191 192 __fnstcw(&_cw); 193 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF); 194 _cw &= ~FP_PRC_FLD; 195 _cw |= (_m << FP_PRC_OFF) & FP_PRC_FLD; 196 __fldcw(&_cw); 197 return (_p); 198 } 199 200 /* 201 * Get or set the exception mask. 202 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1 203 * means disable for x87 and SSE, but for fp*mask() it means enable. 204 */ 205 206 static __inline fp_except_t 207 __fpgetmask(void) 208 { 209 unsigned short _cw; 210 211 __fnstcw(&_cw); 212 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF); 213 } 214 215 static __inline fp_except_t 216 __fpsetmask(fp_except_t _m) 217 { 218 fp_except_t _p; 219 unsigned _mxcsr; 220 unsigned short _cw; 221 222 __fnstcw(&_cw); 223 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF; 224 _cw &= ~FP_MSKS_FLD; 225 _cw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD; 226 __fldcw(&_cw); 227 __stmxcsr(&_mxcsr); 228 /* XXX should we clear non-ieee SSE_DAZ_FLD and SSE_FZ_FLD ? */ 229 _mxcsr &= ~SSE_MSKS_FLD; 230 _mxcsr |= (~_m << SSE_MSKS_OFF) & SSE_MSKS_FLD; 231 __ldmxcsr(&_mxcsr); 232 return (_p); 233 } 234 235 static __inline fp_except_t 236 __fpgetsticky(void) 237 { 238 unsigned _ex, _mxcsr; 239 unsigned short _sw; 240 241 __fnstsw(&_sw); 242 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF; 243 __stmxcsr(&_mxcsr); 244 _ex |= (_mxcsr & SSE_STKY_FLD) >> SSE_STKY_OFF; 245 return ((fp_except_t)_ex); 246 } 247 248 #endif /* __GNUCLIKE_ASM */ 249 250 #if !defined(__IEEEFP_NOINLINES__) && defined(__GNUCLIKE_ASM) 251 252 #define fpgetmask() __fpgetmask() 253 #define fpgetprec() __fpgetprec() 254 #define fpgetround() __fpgetround() 255 #define fpgetsticky() __fpgetsticky() 256 #define fpsetmask(m) __fpsetmask(m) 257 #define fpsetprec(m) __fpsetprec(m) 258 #define fpsetround(m) __fpsetround(m) 259 260 /* Suppress prototypes in the MI header. */ 261 #define _IEEEFP_INLINED_ 1 262 263 #else /* !(!__IEEEFP_NOINLINES__ && __GNUCLIKE_ASM) */ 264 265 /* Augment the userland declarations. */ 266 __BEGIN_DECLS 267 fp_prec_t fpgetprec(void); 268 fp_prec_t fpsetprec(fp_prec_t); 269 __END_DECLS 270 271 #endif /* !__IEEEFP_NOINLINES__ && __GNUCLIKE_ASM */ 272 273 #endif /* !_MACHINE_IEEEFP_H_ */ 274