1/*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 2003 Peter Wemm. 5 * Copyright (c) 1990 Andrew Moore, Talke Studio 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93 37 * $FreeBSD$ 38 */ 39 40#ifndef _MACHINE_IEEEFP_H_ 41#define _MACHINE_IEEEFP_H_ 42 43/* 44 * Deprecated historical FPU control interface 45 * 46 * IEEE floating point type, constant and function definitions. 47 * XXX: {FP,SSE}*FLD and {FP,SSE}*OFF are undocumented pollution. 48 */ 49 50#ifndef _SYS_CDEFS_H_ 51#error this file needs sys/cdefs.h as a prerequisite 52#endif 53 54/* 55 * Rounding modes. 56 */ 57typedef enum { 58 FP_RN=0, /* round to nearest */ 59 FP_RM, /* round down towards minus infinity */ 60 FP_RP, /* round up towards plus infinity */ 61 FP_RZ /* truncate */ 62} fp_rnd_t; 63 64/* 65 * Precision (i.e., rounding precision) modes. 66 */ 67typedef enum { 68 FP_PS=0, /* 24 bit (single-precision) */ 69 FP_PRS, /* reserved */ 70 FP_PD, /* 53 bit (double-precision) */ 71 FP_PE /* 64 bit (extended-precision) */ 72} fp_prec_t; 73 74#define fp_except_t int 75 76/* 77 * Exception bit masks. 78 */ 79#define FP_X_INV 0x01 /* invalid operation */ 80#define FP_X_DNML 0x02 /* denormal */ 81#define FP_X_DZ 0x04 /* zero divide */ 82#define FP_X_OFL 0x08 /* overflow */ 83#define FP_X_UFL 0x10 /* underflow */ 84#define FP_X_IMP 0x20 /* (im)precision */ 85#define FP_X_STK 0x40 /* stack fault */ 86 87/* 88 * FPU control word bit-field masks. 89 */ 90#define FP_MSKS_FLD 0x3f /* exception masks field */ 91#define FP_PRC_FLD 0x300 /* precision control field */ 92#define FP_RND_FLD 0xc00 /* rounding control field */ 93 94/* 95 * FPU status word bit-field masks. 96 */ 97#define FP_STKY_FLD 0x3f /* sticky flags field */ 98 99/* 100 * SSE mxcsr register bit-field masks. 101 */ 102#define SSE_STKY_FLD 0x3f /* exception flags */ 103#define SSE_DAZ_FLD 0x40 /* Denormals are zero */ 104#define SSE_MSKS_FLD 0x1f80 /* exception masks field */ 105#define SSE_RND_FLD 0x6000 /* rounding control */ 106#define SSE_FZ_FLD 0x8000 /* flush to zero on underflow */ 107 108/* 109 * FPU control word bit-field offsets (shift counts). 110 */ 111#define FP_MSKS_OFF 0 /* exception masks offset */ 112#define FP_PRC_OFF 8 /* precision control offset */ 113#define FP_RND_OFF 10 /* rounding control offset */ 114 115/* 116 * FPU status word bit-field offsets (shift counts). 117 */ 118#define FP_STKY_OFF 0 /* sticky flags offset */ 119 120/* 121 * SSE mxcsr register bit-field offsets (shift counts). 122 */ 123#define SSE_STKY_OFF 0 /* exception flags offset */ 124#define SSE_DAZ_OFF 6 /* DAZ exception mask offset */ 125#define SSE_MSKS_OFF 7 /* other exception masks offset */ 126#define SSE_RND_OFF 13 /* rounding control offset */ 127#define SSE_FZ_OFF 15 /* flush to zero offset */ 128 129#ifdef __GNUCLIKE_ASM 130 131#define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr))) 132#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr))) 133#define __fnclex() __asm __volatile("fnclex") 134#define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 135#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr))) 136#define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 137#define __ldmxcsr(addr) __asm __volatile("ldmxcsr %0" : : "m" (*(addr))) 138#define __stmxcsr(addr) __asm __volatile("stmxcsr %0" : "=m" (*(addr))) 139 140/* 141 * Load the control word. Be careful not to trap if there is a currently 142 * unmasked exception (ones that will become freshly unmasked are not a 143 * problem). This case must be handled by a save/restore of the 144 * environment or even of the full x87 state. Accessing the environment 145 * is very inefficient, so only do it when necessary. 146 */ 147static __inline void 148__fnldcw(unsigned short _cw, unsigned short _newcw) 149{ 150 struct { 151 unsigned _cw; 152 unsigned _other[6]; 153 } _env; 154 unsigned short _sw; 155 156 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) { 157 __fnstsw(&_sw); 158 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) { 159 __fnstenv(&_env); 160 _env._cw = _newcw; 161 __fldenv(&_env); 162 return; 163 } 164 } 165 __fldcw(&_newcw); 166} 167 168/* 169 * General notes about conflicting SSE vs FP status bits. 170 * This code assumes that software will not fiddle with the control 171 * bits of the SSE and x87 in such a way to get them out of sync and 172 * still expect this to work. Break this at your peril. 173 * Because I based this on the i386 port, the x87 state is used for 174 * the fpget*() functions, and is shadowed into the SSE state for 175 * the fpset*() functions. For dual source fpget*() functions, I 176 * merge the two together. I think. 177 */ 178 179static __inline fp_rnd_t 180__fpgetround(void) 181{ 182 unsigned short _cw; 183 184 __fnstcw(&_cw); 185 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF)); 186} 187 188static __inline fp_rnd_t 189__fpsetround(fp_rnd_t _m) 190{ 191 fp_rnd_t _p; 192 unsigned _mxcsr; 193 unsigned short _cw, _newcw; 194 195 __fnstcw(&_cw); 196 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF); 197 _newcw = _cw & ~FP_RND_FLD; 198 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD; 199 __fnldcw(_cw, _newcw); 200 __stmxcsr(&_mxcsr); 201 _mxcsr &= ~SSE_RND_FLD; 202 _mxcsr |= (_m << SSE_RND_OFF) & SSE_RND_FLD; 203 __ldmxcsr(&_mxcsr); 204 return (_p); 205} 206 207/* 208 * Get or set the rounding precision for x87 arithmetic operations. 209 * There is no equivalent SSE mode or control. 210 */ 211 212static __inline fp_prec_t 213__fpgetprec(void) 214{ 215 unsigned short _cw; 216 217 __fnstcw(&_cw); 218 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF)); 219} 220 221static __inline fp_prec_t 222__fpsetprec(fp_prec_t _m) 223{ 224 fp_prec_t _p; 225 unsigned short _cw, _newcw; 226 227 __fnstcw(&_cw); 228 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF); 229 _newcw = _cw & ~FP_PRC_FLD; 230 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD; 231 __fnldcw(_cw, _newcw); 232 return (_p); 233} 234 235/* 236 * Get or set the exception mask. 237 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1 238 * means disable for x87 and SSE, but for fp*mask() it means enable. 239 */ 240 241static __inline fp_except_t 242__fpgetmask(void) 243{ 244 unsigned short _cw; 245 246 __fnstcw(&_cw); 247 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF); 248} 249 250static __inline fp_except_t 251__fpsetmask(fp_except_t _m) 252{ 253 fp_except_t _p; 254 unsigned _mxcsr; 255 unsigned short _cw, _newcw; 256 257 __fnstcw(&_cw); 258 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF; 259 _newcw = _cw & ~FP_MSKS_FLD; 260 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD; 261 __fnldcw(_cw, _newcw); 262 __stmxcsr(&_mxcsr); 263 /* XXX should we clear non-ieee SSE_DAZ_FLD and SSE_FZ_FLD ? */ 264 _mxcsr &= ~SSE_MSKS_FLD; 265 _mxcsr |= (~_m << SSE_MSKS_OFF) & SSE_MSKS_FLD; 266 __ldmxcsr(&_mxcsr); 267 return (_p); 268} 269 270static __inline fp_except_t 271__fpgetsticky(void) 272{ 273 unsigned _ex, _mxcsr; 274 unsigned short _sw; 275 276 __fnstsw(&_sw); 277 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF; 278 __stmxcsr(&_mxcsr); 279 _ex |= (_mxcsr & SSE_STKY_FLD) >> SSE_STKY_OFF; 280 return ((fp_except_t)_ex); 281} 282 283#endif /* __GNUCLIKE_ASM */ 284 285#if !defined(__IEEEFP_NOINLINES__) && defined(__GNUCLIKE_ASM) 286 287#define fpgetmask() __fpgetmask() 288#define fpgetprec() __fpgetprec() 289#define fpgetround() __fpgetround() 290#define fpgetsticky() __fpgetsticky() 291#define fpsetmask(m) __fpsetmask(m) 292#define fpsetprec(m) __fpsetprec(m) 293#define fpsetround(m) __fpsetround(m) 294 295#else /* !(!__IEEEFP_NOINLINES__ && __GNUCLIKE_ASM) */ 296 297/* Augment the userland declarations. */ 298__BEGIN_DECLS 299extern fp_rnd_t fpgetround(void); 300extern fp_rnd_t fpsetround(fp_rnd_t); 301extern fp_except_t fpgetmask(void); 302extern fp_except_t fpsetmask(fp_except_t); 303extern fp_except_t fpgetsticky(void); 304extern fp_except_t fpsetsticky(fp_except_t); 305fp_prec_t fpgetprec(void); 306fp_prec_t fpsetprec(fp_prec_t); 307__END_DECLS 308 309#endif /* !__IEEEFP_NOINLINES__ && __GNUCLIKE_ASM */ 310 311#endif /* !_MACHINE_IEEEFP_H_ */ 312