arch/mips/math-emu/ieee754.h

   1 /*
   2  * MIPS floating point support
   3  * Copyright (C) 1994-2000 Algorithmics Ltd.
   4  * http://www.algor.co.uk
   5  *
   6  *  This program is free software; you can distribute it and/or modify it
   7  *  under the terms of the GNU General Public License (Version 2) as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope it will be useful, but WITHOUT
  11  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  *  for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  18  *
  19  *  Nov 7, 2000
  20  *  Modification to allow integration with Linux kernel
  21  *
  22  *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
  23  *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
  24  */
  25 #ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
  26 #define __ARCH_MIPS_MATH_EMU_IEEE754_H
  27
  28 #include <asm/byteorder.h>
  29 #include <linux/types.h>
  30 #include <linux/sched.h>
  31
  32 /*
  33  * Not very pretty, but the Linux kernel's normal va_list definition
  34  * does not allow it to be used as a structure element, as it is here.
  35  */
  36 #ifndef _STDARG_H
  37 #include <stdarg.h>
  38 #endif
  39
  40 #ifdef __LITTLE_ENDIAN
  41 struct ieee754dp_konst {
  42         unsigned mantlo:32;
  43         unsigned manthi:20;
  44         unsigned bexp:11;
  45         unsigned sign:1;
  46 };
  47 struct ieee754sp_konst {
  48         unsigned mant:23;
  49         unsigned bexp:8;
  50         unsigned sign:1;
  51 };
  52
  53 typedef union _ieee754dp {
  54         struct ieee754dp_konst oparts;
  55         struct {
  56                 u64 mant:52;
  57                 unsigned int bexp:11;
  58                 unsigned int sign:1;
  59         } parts;
  60         u64 bits;
  61         double d;
  62 } ieee754dp;
  63
  64 typedef union _ieee754sp {
  65         struct ieee754sp_konst parts;
  66         float f;
  67         u32 bits;
  68 } ieee754sp;
  69 #endif
  70
  71 #ifdef __BIG_ENDIAN
  72 struct ieee754dp_konst {
  73         unsigned sign:1;
  74         unsigned bexp:11;
  75         unsigned manthi:20;
  76         unsigned mantlo:32;
  77 };
  78
  79 typedef union _ieee754dp {
  80         struct ieee754dp_konst oparts;
  81         struct {
  82                 unsigned int sign:1;
  83                 unsigned int bexp:11;
  84                 u64 mant:52;
  85         } parts;
  86         double d;
  87         u64 bits;
  88 } ieee754dp;
  89
  90 struct ieee754sp_konst {
  91         unsigned sign:1;
  92         unsigned bexp:8;
  93         unsigned mant:23;
  94 };
  95
  96 typedef union _ieee754sp {
  97         struct ieee754sp_konst parts;
  98         float f;
  99         u32 bits;
 100 } ieee754sp;
 101 #endif
 102
 103 /*
 104  * single precision (often aka float)
 105 */
 106 int ieee754sp_finite(ieee754sp x);
 107 int ieee754sp_class(ieee754sp x);
 108
 109 ieee754sp ieee754sp_abs(ieee754sp x);
 110 ieee754sp ieee754sp_neg(ieee754sp x);
 111 ieee754sp ieee754sp_scalb(ieee754sp x, int);
 112 ieee754sp ieee754sp_logb(ieee754sp x);
 113
 114 /* x with sign of y */
 115 ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
 116
 117 ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
 118 ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
 119 ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
 120 ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
 121
 122 ieee754sp ieee754sp_fint(int x);
 123 ieee754sp ieee754sp_funs(unsigned x);
 124 ieee754sp ieee754sp_flong(s64 x);
 125 ieee754sp ieee754sp_fulong(u64 x);
 126 ieee754sp ieee754sp_fdp(ieee754dp x);
 127
 128 int ieee754sp_tint(ieee754sp x);
 129 unsigned int ieee754sp_tuns(ieee754sp x);
 130 s64 ieee754sp_tlong(ieee754sp x);
 131 u64 ieee754sp_tulong(ieee754sp x);
 132
 133 int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
 134 /*
 135  * basic sp math
 136  */
 137 ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
 138 ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
 139 ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
 140
 141 ieee754sp ieee754sp_ceil(ieee754sp x);
 142 ieee754sp ieee754sp_floor(ieee754sp x);
 143 ieee754sp ieee754sp_trunc(ieee754sp x);
 144
 145 ieee754sp ieee754sp_sqrt(ieee754sp x);
 146
 147 /*
 148  * double precision (often aka double)
 149 */
 150 int ieee754dp_finite(ieee754dp x);
 151 int ieee754dp_class(ieee754dp x);
 152
 153 /* x with sign of y */
 154 ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
 155
 156 ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
 157 ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
 158 ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
 159 ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
 160
 161 ieee754dp ieee754dp_abs(ieee754dp x);
 162 ieee754dp ieee754dp_neg(ieee754dp x);
 163 ieee754dp ieee754dp_scalb(ieee754dp x, int);
 164
 165 /* return exponent as integer in floating point format
 166  */
 167 ieee754dp ieee754dp_logb(ieee754dp x);
 168
 169 ieee754dp ieee754dp_fint(int x);
 170 ieee754dp ieee754dp_funs(unsigned x);
 171 ieee754dp ieee754dp_flong(s64 x);
 172 ieee754dp ieee754dp_fulong(u64 x);
 173 ieee754dp ieee754dp_fsp(ieee754sp x);
 174
 175 ieee754dp ieee754dp_ceil(ieee754dp x);
 176 ieee754dp ieee754dp_floor(ieee754dp x);
 177 ieee754dp ieee754dp_trunc(ieee754dp x);
 178
 179 int ieee754dp_tint(ieee754dp x);
 180 unsigned int ieee754dp_tuns(ieee754dp x);
 181 s64 ieee754dp_tlong(ieee754dp x);
 182 u64 ieee754dp_tulong(ieee754dp x);
 183
 184 int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
 185 /*
 186  * basic sp math
 187  */
 188 ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
 189 ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
 190 ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
 191
 192 ieee754dp ieee754dp_ceil(ieee754dp x);
 193 ieee754dp ieee754dp_floor(ieee754dp x);
 194 ieee754dp ieee754dp_trunc(ieee754dp x);
 195
 196 ieee754dp ieee754dp_sqrt(ieee754dp x);
 197
 198
 199
 200 /* 5 types of floating point number
 201 */
 202 #define IEEE754_CLASS_NORM      0x00
 203 #define IEEE754_CLASS_ZERO      0x01
 204 #define IEEE754_CLASS_DNORM     0x02
 205 #define IEEE754_CLASS_INF       0x03
 206 #define IEEE754_CLASS_SNAN      0x04
 207 #define IEEE754_CLASS_QNAN      0x05
 208
 209 /* exception numbers */
 210 #define IEEE754_INEXACT                 0x01
 211 #define IEEE754_UNDERFLOW               0x02
 212 #define IEEE754_OVERFLOW                0x04
 213 #define IEEE754_ZERO_DIVIDE             0x08
 214 #define IEEE754_INVALID_OPERATION       0x10
 215
 216 /* cmp operators
 217 */
 218 #define IEEE754_CLT     0x01
 219 #define IEEE754_CEQ     0x02
 220 #define IEEE754_CGT     0x04
 221 #define IEEE754_CUN     0x08
 222
 223 /* rounding mode
 224 */
 225 #define IEEE754_RN      0       /* round to nearest */
 226 #define IEEE754_RZ      1       /* round toward zero  */
 227 #define IEEE754_RD      2       /* round toward -Infinity */
 228 #define IEEE754_RU      3       /* round toward +Infinity */
 229
 230 /* other naming */
 231 #define IEEE754_RM      IEEE754_RD
 232 #define IEEE754_RP      IEEE754_RU
 233
 234 /* "normal" comparisons
 235 */
 236 static inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
 237 {
 238         return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
 239 }
 240
 241 static inline int ieee754sp_ne(ieee754sp x, ieee754sp y)
 242 {
 243         return ieee754sp_cmp(x, y,
 244                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 245 }
 246
 247 static inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
 248 {
 249         return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
 250 }
 251
 252 static inline int ieee754sp_le(ieee754sp x, ieee754sp y)
 253 {
 254         return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 255 }
 256
 257 static inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
 258 {
 259         return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
 260 }
 261
 262
 263 static inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
 264 {
 265         return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 266 }
 267
 268 static inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
 269 {
 270         return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
 271 }
 272
 273 static inline int ieee754dp_ne(ieee754dp x, ieee754dp y)
 274 {
 275         return ieee754dp_cmp(x, y,
 276                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 277 }
 278
 279 static inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
 280 {
 281         return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
 282 }
 283
 284 static inline int ieee754dp_le(ieee754dp x, ieee754dp y)
 285 {
 286         return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 287 }
 288
 289 static inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
 290 {
 291         return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
 292 }
 293
 294 static inline int ieee754dp_ge(ieee754dp x, ieee754dp y)
 295 {
 296         return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 297 }
 298
 299
 300 /*
 301  * Like strtod
 302  */
 303 ieee754dp ieee754dp_fstr(const char *s, char **endp);
 304 char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
 305
 306
 307 /*
 308  * The control status register
 309  */
 310 struct _ieee754_csr {
 311 #ifdef __BIG_ENDIAN
 312         unsigned pad0:7;
 313         unsigned nod:1;         /* set 1 for no denormalised numbers */
 314         unsigned c:1;           /* condition */
 315         unsigned pad1:5;
 316         unsigned cx:6;          /* exceptions this operation */
 317         unsigned mx:5;          /* exception enable  mask */
 318         unsigned sx:5;          /* exceptions total */
 319         unsigned rm:2;          /* current rounding mode */
 320 #endif
 321 #ifdef __LITTLE_ENDIAN
 322         unsigned rm:2;          /* current rounding mode */
 323         unsigned sx:5;          /* exceptions total */
 324         unsigned mx:5;          /* exception enable  mask */
 325         unsigned cx:6;          /* exceptions this operation */
 326         unsigned pad1:5;
 327         unsigned c:1;           /* condition */
 328         unsigned nod:1;         /* set 1 for no denormalised numbers */
 329         unsigned pad0:7;
 330 #endif
 331 };
 332 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
 333
 334 static inline unsigned ieee754_getrm(void)
 335 {
 336         return (ieee754_csr.rm);
 337 }
 338 static inline unsigned ieee754_setrm(unsigned rm)
 339 {
 340         return (ieee754_csr.rm = rm);
 341 }
 342
 343 /*
 344  * get current exceptions
 345  */
 346 static inline unsigned ieee754_getcx(void)
 347 {
 348         return (ieee754_csr.cx);
 349 }
 350
 351 /* test for current exception condition
 352  */
 353 static inline int ieee754_cxtest(unsigned n)
 354 {
 355         return (ieee754_csr.cx & n);
 356 }
 357
 358 /*
 359  * get sticky exceptions
 360  */
 361 static inline unsigned ieee754_getsx(void)
 362 {
 363         return (ieee754_csr.sx);
 364 }
 365
 366 /* clear sticky conditions
 367 */
 368 static inline unsigned ieee754_clrsx(void)
 369 {
 370         return (ieee754_csr.sx = 0);
 371 }
 372
 373 /* test for sticky exception condition
 374  */
 375 static inline int ieee754_sxtest(unsigned n)
 376 {
 377         return (ieee754_csr.sx & n);
 378 }
 379
 380 /* debugging */
 381 ieee754sp ieee754sp_dump(char *s, ieee754sp x);
 382 ieee754dp ieee754dp_dump(char *s, ieee754dp x);
 383
 384 #define IEEE754_SPCVAL_PZERO    0
 385 #define IEEE754_SPCVAL_NZERO    1
 386 #define IEEE754_SPCVAL_PONE     2
 387 #define IEEE754_SPCVAL_NONE     3
 388 #define IEEE754_SPCVAL_PTEN     4
 389 #define IEEE754_SPCVAL_NTEN     5
 390 #define IEEE754_SPCVAL_PINFINITY        6
 391 #define IEEE754_SPCVAL_NINFINITY        7
 392 #define IEEE754_SPCVAL_INDEF    8
 393 #define IEEE754_SPCVAL_PMAX     9       /* +max norm */
 394 #define IEEE754_SPCVAL_NMAX     10      /* -max norm */
 395 #define IEEE754_SPCVAL_PMIN     11      /* +min norm */
 396 #define IEEE754_SPCVAL_NMIN     12      /* +min norm */
 397 #define IEEE754_SPCVAL_PMIND    13      /* +min denorm */
 398 #define IEEE754_SPCVAL_NMIND    14      /* +min denorm */
 399 #define IEEE754_SPCVAL_P1E31    15      /* + 1.0e31 */
 400 #define IEEE754_SPCVAL_P1E63    16      /* + 1.0e63 */
 401
 402 extern const struct ieee754dp_konst __ieee754dp_spcvals[];
 403 extern const struct ieee754sp_konst __ieee754sp_spcvals[];
 404 #define ieee754dp_spcvals ((const ieee754dp *)__ieee754dp_spcvals)
 405 #define ieee754sp_spcvals ((const ieee754sp *)__ieee754sp_spcvals)
 406
 407 /*
 408  * Return infinity with given sign
 409  */
 410 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 411 #define ieee754dp_zero(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 412 #define ieee754dp_one(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 413 #define ieee754dp_ten(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 414 #define ieee754dp_indef()       (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
 415 #define ieee754dp_max(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 416 #define ieee754dp_min(sn)       (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 417 #define ieee754dp_mind(sn)      (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 418 #define ieee754dp_1e31()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 419 #define ieee754dp_1e63()        (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 420
 421 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 422 #define ieee754sp_zero(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 423 #define ieee754sp_one(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 424 #define ieee754sp_ten(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 425 #define ieee754sp_indef()       (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
 426 #define ieee754sp_max(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 427 #define ieee754sp_min(sn)       (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 428 #define ieee754sp_mind(sn)      (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 429 #define ieee754sp_1e31()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 430 #define ieee754sp_1e63()        (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 431
 432 /*
 433  * Indefinite integer value
 434  */
 435 #define ieee754si_indef()       INT_MAX
 436 #ifdef LONG_LONG_MAX
 437 #define ieee754di_indef()       LONG_LONG_MAX
 438 #else
 439 #define ieee754di_indef()       ((s64)(~0ULL>>1))
 440 #endif
 441
 442 /* IEEE exception context, passed to handler */
 443 struct ieee754xctx {
 444         const char *op;         /* operation name */
 445         int rt;                 /* result type */
 446         union {
 447                 ieee754sp sp;   /* single precision */
 448                 ieee754dp dp;   /* double precision */
 449 #ifdef IEEE854_XP
 450                 ieee754xp xp;   /* extended precision */
 451 #endif
 452                 int si;         /* standard signed integer (32bits) */
 453                 s64 di;         /* extended signed integer (64bits) */
 454         } rv;                   /* default result format implied by op */
 455         va_list ap;
 456 };
 457
 458 /* result types for xctx.rt */
 459 #define IEEE754_RT_SP   0
 460 #define IEEE754_RT_DP   1
 461 #define IEEE754_RT_XP   2
 462 #define IEEE754_RT_SI   3
 463 #define IEEE754_RT_DI   4
 464
 465 extern void ieee754_xcpt(struct ieee754xctx *xcp);
 466
 467 /* compat */
 468 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 469 #define ieee754sp_fix(x)        ieee754sp_tint(x)
 470
 471 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */