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