arch/mips/math-emu/ieee754.h

   1 /*
   2  * MIPS floating point support
   3  * Copyright (C) 1994-2000 Algorithmics Ltd.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  *  Nov 7, 2000
  19  *  Modification to allow integration with Linux kernel
  20  *
  21  *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
  22  *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
  23  */
  24 #ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
  25 #define __ARCH_MIPS_MATH_EMU_IEEE754_H
  26
  27 #include <linux/compiler.h>
  28 #include <asm/byteorder.h>
  29 #include <linux/types.h>
  30 #include <linux/sched.h>
  31 #include <asm/bitfield.h>
  32
  33 /*
  34  * Not very pretty, but the Linux kernel's normal va_list definition
  35  * does not allow it to be used as a structure element, as it is here.
  36  */
  37 #ifndef _STDARG_H
  38 #include <stdarg.h>
  39 #endif
  40
  41 struct ieee754dp_const {
  42         __BITFIELD_FIELD(unsigned sign:1,
  43         __BITFIELD_FIELD(unsigned bexp:11,
  44         __BITFIELD_FIELD(unsigned manthi:20,
  45         __BITFIELD_FIELD(unsigned mantlo:32,
  46         ;))))
  47 };
  48
  49 union ieee754dp {
  50         struct ieee754dp_const oparts;
  51         struct {
  52                 __BITFIELD_FIELD(unsigned int sign:1,
  53                 __BITFIELD_FIELD(unsigned int bexp:11,
  54                 __BITFIELD_FIELD(u64 mant:52,
  55                 ;)))
  56         } parts;
  57         double d;
  58         u64 bits;
  59 };
  60
  61 struct ieee754sp_const {
  62         __BITFIELD_FIELD(unsigned sign:1,
  63         __BITFIELD_FIELD(unsigned bexp:8,
  64         __BITFIELD_FIELD(unsigned mant:23,
  65         ;)))
  66 };
  67
  68 union ieee754sp {
  69         struct ieee754sp_const parts;
  70         float f;
  71         u32 bits;
  72 };
  73
  74 /*
  75  * single precision (often aka float)
  76 */
  77 int ieee754sp_finite(union ieee754sp x);
  78 int ieee754sp_class(union ieee754sp x);
  79
  80 union ieee754sp ieee754sp_abs(union ieee754sp x);
  81 union ieee754sp ieee754sp_neg(union ieee754sp x);
  82 union ieee754sp ieee754sp_scalb(union ieee754sp x, int);
  83 union ieee754sp ieee754sp_logb(union ieee754sp x);
  84
  85 /* x with sign of y */
  86 union ieee754sp ieee754sp_copysign(union ieee754sp x, union ieee754sp y);
  87
  88 union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
  89 union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
  90 union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
  91 union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
  92
  93 union ieee754sp ieee754sp_fint(int x);
  94 union ieee754sp ieee754sp_funs(unsigned x);
  95 union ieee754sp ieee754sp_flong(s64 x);
  96 union ieee754sp ieee754sp_fulong(u64 x);
  97 union ieee754sp ieee754sp_fdp(union ieee754dp x);
  98
  99 int ieee754sp_tint(union ieee754sp x);
 100 unsigned int ieee754sp_tuns(union ieee754sp x);
 101 s64 ieee754sp_tlong(union ieee754sp x);
 102 u64 ieee754sp_tulong(union ieee754sp x);
 103
 104 int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
 105 /*
 106  * basic sp math
 107  */
 108 union ieee754sp ieee754sp_modf(union ieee754sp x, union ieee754sp * ip);
 109 union ieee754sp ieee754sp_frexp(union ieee754sp x, int *exp);
 110 union ieee754sp ieee754sp_ldexp(union ieee754sp x, int exp);
 111
 112 union ieee754sp ieee754sp_ceil(union ieee754sp x);
 113 union ieee754sp ieee754sp_floor(union ieee754sp x);
 114 union ieee754sp ieee754sp_trunc(union ieee754sp x);
 115
 116 union ieee754sp ieee754sp_sqrt(union ieee754sp x);
 117
 118 /*
 119  * double precision (often aka double)
 120 */
 121 int ieee754dp_finite(union ieee754dp x);
 122 int ieee754dp_class(union ieee754dp x);
 123
 124 /* x with sign of y */
 125 union ieee754dp ieee754dp_copysign(union ieee754dp x, union ieee754dp y);
 126
 127 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
 128 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
 129 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
 130 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
 131
 132 union ieee754dp ieee754dp_abs(union ieee754dp x);
 133 union ieee754dp ieee754dp_neg(union ieee754dp x);
 134 union ieee754dp ieee754dp_scalb(union ieee754dp x, int);
 135
 136 /* return exponent as integer in floating point format
 137  */
 138 union ieee754dp ieee754dp_logb(union ieee754dp x);
 139
 140 union ieee754dp ieee754dp_fint(int x);
 141 union ieee754dp ieee754dp_funs(unsigned x);
 142 union ieee754dp ieee754dp_flong(s64 x);
 143 union ieee754dp ieee754dp_fulong(u64 x);
 144 union ieee754dp ieee754dp_fsp(union ieee754sp x);
 145
 146 union ieee754dp ieee754dp_ceil(union ieee754dp x);
 147 union ieee754dp ieee754dp_floor(union ieee754dp x);
 148 union ieee754dp ieee754dp_trunc(union ieee754dp x);
 149
 150 int ieee754dp_tint(union ieee754dp x);
 151 unsigned int ieee754dp_tuns(union ieee754dp x);
 152 s64 ieee754dp_tlong(union ieee754dp x);
 153 u64 ieee754dp_tulong(union ieee754dp x);
 154
 155 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
 156 /*
 157  * basic sp math
 158  */
 159 union ieee754dp ieee754dp_modf(union ieee754dp x, union ieee754dp * ip);
 160 union ieee754dp ieee754dp_frexp(union ieee754dp x, int *exp);
 161 union ieee754dp ieee754dp_ldexp(union ieee754dp x, int exp);
 162
 163 union ieee754dp ieee754dp_ceil(union ieee754dp x);
 164 union ieee754dp ieee754dp_floor(union ieee754dp x);
 165 union ieee754dp ieee754dp_trunc(union ieee754dp x);
 166
 167 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
 168
 169
 170
 171 /* 5 types of floating point number
 172 */
 173 #define IEEE754_CLASS_NORM      0x00
 174 #define IEEE754_CLASS_ZERO      0x01
 175 #define IEEE754_CLASS_DNORM     0x02
 176 #define IEEE754_CLASS_INF       0x03
 177 #define IEEE754_CLASS_SNAN      0x04
 178 #define IEEE754_CLASS_QNAN      0x05
 179
 180 /* exception numbers */
 181 #define IEEE754_INEXACT                 0x01
 182 #define IEEE754_UNDERFLOW               0x02
 183 #define IEEE754_OVERFLOW                0x04
 184 #define IEEE754_ZERO_DIVIDE             0x08
 185 #define IEEE754_INVALID_OPERATION       0x10
 186
 187 /* cmp operators
 188 */
 189 #define IEEE754_CLT     0x01
 190 #define IEEE754_CEQ     0x02
 191 #define IEEE754_CGT     0x04
 192 #define IEEE754_CUN     0x08
 193
 194 /* rounding mode
 195 */
 196 #define IEEE754_RN      0       /* round to nearest */
 197 #define IEEE754_RZ      1       /* round toward zero  */
 198 #define IEEE754_RD      2       /* round toward -Infinity */
 199 #define IEEE754_RU      3       /* round toward +Infinity */
 200
 201 /* other naming */
 202 #define IEEE754_RM      IEEE754_RD
 203 #define IEEE754_RP      IEEE754_RU
 204
 205 /* "normal" comparisons
 206 */
 207 static inline int ieee754sp_eq(union ieee754sp x, union ieee754sp y)
 208 {
 209         return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
 210 }
 211
 212 static inline int ieee754sp_ne(union ieee754sp x, union ieee754sp y)
 213 {
 214         return ieee754sp_cmp(x, y,
 215                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 216 }
 217
 218 static inline int ieee754sp_lt(union ieee754sp x, union ieee754sp y)
 219 {
 220         return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
 221 }
 222
 223 static inline int ieee754sp_le(union ieee754sp x, union ieee754sp y)
 224 {
 225         return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 226 }
 227
 228 static inline int ieee754sp_gt(union ieee754sp x, union ieee754sp y)
 229 {
 230         return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
 231 }
 232
 233
 234 static inline int ieee754sp_ge(union ieee754sp x, union ieee754sp y)
 235 {
 236         return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 237 }
 238
 239 static inline int ieee754dp_eq(union ieee754dp x, union ieee754dp y)
 240 {
 241         return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
 242 }
 243
 244 static inline int ieee754dp_ne(union ieee754dp x, union ieee754dp y)
 245 {
 246         return ieee754dp_cmp(x, y,
 247                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 248 }
 249
 250 static inline int ieee754dp_lt(union ieee754dp x, union ieee754dp y)
 251 {
 252         return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
 253 }
 254
 255 static inline int ieee754dp_le(union ieee754dp x, union ieee754dp y)
 256 {
 257         return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 258 }
 259
 260 static inline int ieee754dp_gt(union ieee754dp x, union ieee754dp y)
 261 {
 262         return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
 263 }
 264
 265 static inline int ieee754dp_ge(union ieee754dp x, union ieee754dp y)
 266 {
 267         return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 268 }
 269
 270
 271 /*
 272  * Like strtod
 273  */
 274 union ieee754dp ieee754dp_fstr(const char *s, char **endp);
 275 char *ieee754dp_tstr(union ieee754dp x, int prec, int fmt, int af);
 276
 277
 278 /*
 279  * The control status register
 280  */
 281 struct _ieee754_csr {
 282         __BITFIELD_FIELD(unsigned pad0:7,
 283         __BITFIELD_FIELD(unsigned nod:1,        /* set 1 for no denormalised numbers */
 284         __BITFIELD_FIELD(unsigned c:1,          /* condition */
 285         __BITFIELD_FIELD(unsigned pad1:5,
 286         __BITFIELD_FIELD(unsigned cx:6,         /* exceptions this operation */
 287         __BITFIELD_FIELD(unsigned mx:5,         /* exception enable  mask */
 288         __BITFIELD_FIELD(unsigned sx:5,         /* exceptions total */
 289         __BITFIELD_FIELD(unsigned rm:2,         /* current rounding mode */
 290         ;))))))))
 291 };
 292 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
 293
 294 static inline unsigned ieee754_getrm(void)
 295 {
 296         return (ieee754_csr.rm);
 297 }
 298 static inline unsigned ieee754_setrm(unsigned rm)
 299 {
 300         return (ieee754_csr.rm = rm);
 301 }
 302
 303 /*
 304  * get current exceptions
 305  */
 306 static inline unsigned ieee754_getcx(void)
 307 {
 308         return (ieee754_csr.cx);
 309 }
 310
 311 /* test for current exception condition
 312  */
 313 static inline int ieee754_cxtest(unsigned n)
 314 {
 315         return (ieee754_csr.cx & n);
 316 }
 317
 318 /*
 319  * get sticky exceptions
 320  */
 321 static inline unsigned ieee754_getsx(void)
 322 {
 323         return (ieee754_csr.sx);
 324 }
 325
 326 /* clear sticky conditions
 327 */
 328 static inline unsigned ieee754_clrsx(void)
 329 {
 330         return (ieee754_csr.sx = 0);
 331 }
 332
 333 /* test for sticky exception condition
 334  */
 335 static inline int ieee754_sxtest(unsigned n)
 336 {
 337         return (ieee754_csr.sx & n);
 338 }
 339
 340 /* debugging */
 341 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
 342 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
 343
 344 #define IEEE754_SPCVAL_PZERO    0
 345 #define IEEE754_SPCVAL_NZERO    1
 346 #define IEEE754_SPCVAL_PONE     2
 347 #define IEEE754_SPCVAL_NONE     3
 348 #define IEEE754_SPCVAL_PTEN     4
 349 #define IEEE754_SPCVAL_NTEN     5
 350 #define IEEE754_SPCVAL_PINFINITY        6
 351 #define IEEE754_SPCVAL_NINFINITY        7
 352 #define IEEE754_SPCVAL_INDEF    8
 353 #define IEEE754_SPCVAL_PMAX     9       /* +max norm */
 354 #define IEEE754_SPCVAL_NMAX     10      /* -max norm */
 355 #define IEEE754_SPCVAL_PMIN     11      /* +min norm */
 356 #define IEEE754_SPCVAL_NMIN     12      /* +min norm */
 357 #define IEEE754_SPCVAL_PMIND    13      /* +min denorm */
 358 #define IEEE754_SPCVAL_NMIND    14      /* +min denorm */
 359 #define IEEE754_SPCVAL_P1E31    15      /* + 1.0e31 */
 360 #define IEEE754_SPCVAL_P1E63    16      /* + 1.0e63 */
 361
 362 extern const struct ieee754dp_const __ieee754dp_spcvals[];
 363 extern const struct ieee754sp_const __ieee754sp_spcvals[];
 364 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
 365 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
 366
 367 /*
 368  * Return infinity with given sign
 369  */
 370 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 371 #define ieee754dp_zero(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 372 #define ieee754dp_one(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 373 #define ieee754dp_ten(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 374 #define ieee754dp_indef()       (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
 375 #define ieee754dp_max(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 376 #define ieee754dp_min(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 377 #define ieee754dp_mind(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 378 #define ieee754dp_1e31()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 379 #define ieee754dp_1e63()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 380
 381 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 382 #define ieee754sp_zero(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 383 #define ieee754sp_one(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 384 #define ieee754sp_ten(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 385 #define ieee754sp_indef()       (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
 386 #define ieee754sp_max(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 387 #define ieee754sp_min(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 388 #define ieee754sp_mind(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 389 #define ieee754sp_1e31()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 390 #define ieee754sp_1e63()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 391
 392 /*
 393  * Indefinite integer value
 394  */
 395 #define ieee754si_indef()       INT_MAX
 396 #ifdef LONG_LONG_MAX
 397 #define ieee754di_indef()       LONG_LONG_MAX
 398 #else
 399 #define ieee754di_indef()       ((s64)(~0ULL>>1))
 400 #endif
 401
 402 /* IEEE exception context, passed to handler */
 403 struct ieee754xctx {
 404         const char *op;         /* operation name */
 405         int rt;                 /* result type */
 406         union {
 407                 union ieee754sp sp;     /* single precision */
 408                 union ieee754dp dp;     /* double precision */
 409 #ifdef IEEE854_XP
 410                 ieee754xp xp;   /* extended precision */
 411 #endif
 412                 int si;         /* standard signed integer (32bits) */
 413                 s64 di;         /* extended signed integer (64bits) */
 414         } rv;                   /* default result format implied by op */
 415         va_list ap;
 416 };
 417
 418 /* result types for xctx.rt */
 419 #define IEEE754_RT_SP   0
 420 #define IEEE754_RT_DP   1
 421 #define IEEE754_RT_XP   2
 422 #define IEEE754_RT_SI   3
 423 #define IEEE754_RT_DI   4
 424
 425 extern void __cold ieee754_xcpt(struct ieee754xctx *xcp);
 426
 427 /* compat */
 428 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 429 #define ieee754sp_fix(x)        ieee754sp_tint(x)
 430
 431 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */