arch/mips/math-emu/ieee754.h

   1 /* single and double precision fp ops
   2  * missing extended precision.
   3 */
   4 /*
   5  * MIPS floating point support
   6  * Copyright (C) 1994-2000 Algorithmics Ltd.
   7  * http://www.algor.co.uk
   8  *
   9  * ########################################################################
  10  *
  11  *  This program is free software; you can distribute it and/or modify it
  12  *  under the terms of the GNU General Public License (Version 2) as
  13  *  published by the Free Software Foundation.
  14  *
  15  *  This program is distributed in the hope it will be useful, but WITHOUT
  16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  *  for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  23  *
  24  * ########################################################################
  25  */
  26
  27 /**************************************************************************
  28  *  Nov 7, 2000
  29  *  Modification to allow integration with Linux kernel
  30  *
  31  *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
  32  *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
  33  *************************************************************************/
  34
  35 #ifdef __KERNEL__
  36 /* Going from Algorithmics to Linux native environment, add this */
  37 #include <linux/types.h>
  38
  39 /*
  40  * Not very pretty, but the Linux kernel's normal va_list definition
  41  * does not allow it to be used as a structure element, as it is here.
  42  */
  43 #ifndef _STDARG_H
  44 #include <stdarg.h>
  45 #endif
  46
  47 #else
  48
  49 /* Note that __KERNEL__ is taken to mean Linux kernel */
  50
  51 #if #system(OpenBSD)
  52 #include <machine/types.h>
  53 #endif
  54 #include <machine/endian.h>
  55
  56 #endif                          /* __KERNEL__ */
  57
  58 #if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__)
  59 struct ieee754dp_konst {
  60         unsigned mantlo:32;
  61         unsigned manthi:20;
  62         unsigned bexp:11;
  63         unsigned sign:1;
  64 };
  65 struct ieee754sp_konst {
  66         unsigned mant:23;
  67         unsigned bexp:8;
  68         unsigned sign:1;
  69 };
  70
  71 typedef union _ieee754dp {
  72         struct ieee754dp_konst oparts;
  73         struct {
  74                 u64 mant:52;
  75                 unsigned int bexp:11;
  76                 unsigned int sign:1;
  77         } parts;
  78         u64 bits;
  79         double d;
  80 } ieee754dp;
  81
  82 typedef union _ieee754sp {
  83         struct ieee754sp_konst parts;
  84         float f;
  85         u32 bits;
  86 } ieee754sp;
  87 #endif
  88
  89 #if (defined(BYTE_ORDER) && BYTE_ORDER == BIG_ENDIAN) || defined(__MIPSEB__)
  90 struct ieee754dp_konst {
  91         unsigned sign:1;
  92         unsigned bexp:11;
  93         unsigned manthi:20;
  94         unsigned mantlo:32;
  95 };
  96 typedef union _ieee754dp {
  97         struct ieee754dp_konst oparts;
  98         struct {
  99                 unsigned int sign:1;
 100                 unsigned int bexp:11;
 101                 u64 mant:52;
 102         } parts;
 103         double d;
 104         u64 bits;
 105 } ieee754dp;
 106
 107 struct ieee754sp_konst {
 108         unsigned sign:1;
 109         unsigned bexp:8;
 110         unsigned mant:23;
 111 };
 112
 113 typedef union _ieee754sp {
 114         struct ieee754sp_konst parts;
 115         float f;
 116         u32 bits;
 117 } ieee754sp;
 118 #endif
 119
 120 /*
 121  * single precision (often aka float)
 122 */
 123 int ieee754sp_finite(ieee754sp x);
 124 int ieee754sp_class(ieee754sp x);
 125
 126 ieee754sp ieee754sp_abs(ieee754sp x);
 127 ieee754sp ieee754sp_neg(ieee754sp x);
 128 ieee754sp ieee754sp_scalb(ieee754sp x, int);
 129 ieee754sp ieee754sp_logb(ieee754sp x);
 130
 131 /* x with sign of y */
 132 ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
 133
 134 ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
 135 ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
 136 ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
 137 ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
 138
 139 ieee754sp ieee754sp_fint(int x);
 140 ieee754sp ieee754sp_funs(unsigned x);
 141 ieee754sp ieee754sp_flong(s64 x);
 142 ieee754sp ieee754sp_fulong(u64 x);
 143 ieee754sp ieee754sp_fdp(ieee754dp x);
 144
 145 int ieee754sp_tint(ieee754sp x);
 146 unsigned int ieee754sp_tuns(ieee754sp x);
 147 s64 ieee754sp_tlong(ieee754sp x);
 148 u64 ieee754sp_tulong(ieee754sp x);
 149
 150 int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
 151 /*
 152  * basic sp math
 153  */
 154 ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
 155 ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
 156 ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
 157
 158 ieee754sp ieee754sp_ceil(ieee754sp x);
 159 ieee754sp ieee754sp_floor(ieee754sp x);
 160 ieee754sp ieee754sp_trunc(ieee754sp x);
 161
 162 ieee754sp ieee754sp_sqrt(ieee754sp x);
 163
 164 /*
 165  * double precision (often aka double)
 166 */
 167 int ieee754dp_finite(ieee754dp x);
 168 int ieee754dp_class(ieee754dp x);
 169
 170 /* x with sign of y */
 171 ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
 172
 173 ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
 174 ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
 175 ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
 176 ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
 177
 178 ieee754dp ieee754dp_abs(ieee754dp x);
 179 ieee754dp ieee754dp_neg(ieee754dp x);
 180 ieee754dp ieee754dp_scalb(ieee754dp x, int);
 181
 182 /* return exponent as integer in floating point format
 183  */
 184 ieee754dp ieee754dp_logb(ieee754dp x);
 185
 186 ieee754dp ieee754dp_fint(int x);
 187 ieee754dp ieee754dp_funs(unsigned x);
 188 ieee754dp ieee754dp_flong(s64 x);
 189 ieee754dp ieee754dp_fulong(u64 x);
 190 ieee754dp ieee754dp_fsp(ieee754sp x);
 191
 192 ieee754dp ieee754dp_ceil(ieee754dp x);
 193 ieee754dp ieee754dp_floor(ieee754dp x);
 194 ieee754dp ieee754dp_trunc(ieee754dp x);
 195
 196 int ieee754dp_tint(ieee754dp x);
 197 unsigned int ieee754dp_tuns(ieee754dp x);
 198 s64 ieee754dp_tlong(ieee754dp x);
 199 u64 ieee754dp_tulong(ieee754dp x);
 200
 201 int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
 202 /*
 203  * basic sp math
 204  */
 205 ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
 206 ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
 207 ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
 208
 209 ieee754dp ieee754dp_ceil(ieee754dp x);
 210 ieee754dp ieee754dp_floor(ieee754dp x);
 211 ieee754dp ieee754dp_trunc(ieee754dp x);
 212
 213 ieee754dp ieee754dp_sqrt(ieee754dp x);
 214
 215
 216
 217 /* 5 types of floating point number
 218 */
 219 #define IEEE754_CLASS_NORM      0x00
 220 #define IEEE754_CLASS_ZERO      0x01
 221 #define IEEE754_CLASS_DNORM     0x02
 222 #define IEEE754_CLASS_INF       0x03
 223 #define IEEE754_CLASS_SNAN      0x04
 224 #define IEEE754_CLASS_QNAN      0x05
 225 extern const char *const ieee754_cname[];
 226
 227 /* exception numbers */
 228 #define IEEE754_INEXACT                 0x01
 229 #define IEEE754_UNDERFLOW               0x02
 230 #define IEEE754_OVERFLOW                0x04
 231 #define IEEE754_ZERO_DIVIDE             0x08
 232 #define IEEE754_INVALID_OPERATION       0x10
 233
 234 /* cmp operators
 235 */
 236 #define IEEE754_CLT     0x01
 237 #define IEEE754_CEQ     0x02
 238 #define IEEE754_CGT     0x04
 239 #define IEEE754_CUN     0x08
 240
 241 /* rounding mode
 242 */
 243 #define IEEE754_RN      0       /* round to nearest */
 244 #define IEEE754_RZ      1       /* round toward zero  */
 245 #define IEEE754_RD      2       /* round toward -Infinity */
 246 #define IEEE754_RU      3       /* round toward +Infinity */
 247
 248 /* other naming */
 249 #define IEEE754_RM      IEEE754_RD
 250 #define IEEE754_RP      IEEE754_RU
 251
 252 /* "normal" comparisons
 253 */
 254 static __inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
 255 {
 256         return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
 257 }
 258
 259 static __inline int ieee754sp_ne(ieee754sp x, ieee754sp y)
 260 {
 261         return ieee754sp_cmp(x, y,
 262                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 263 }
 264
 265 static __inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
 266 {
 267         return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
 268 }
 269
 270 static __inline int ieee754sp_le(ieee754sp x, ieee754sp y)
 271 {
 272         return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 273 }
 274
 275 static __inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
 276 {
 277         return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
 278 }
 279
 280
 281 static __inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
 282 {
 283         return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 284 }
 285
 286 static __inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
 287 {
 288         return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
 289 }
 290
 291 static __inline int ieee754dp_ne(ieee754dp x, ieee754dp y)
 292 {
 293         return ieee754dp_cmp(x, y,
 294                              IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
 295 }
 296
 297 static __inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
 298 {
 299         return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
 300 }
 301
 302 static __inline int ieee754dp_le(ieee754dp x, ieee754dp y)
 303 {
 304         return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 305 }
 306
 307 static __inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
 308 {
 309         return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
 310 }
 311
 312 static __inline int ieee754dp_ge(ieee754dp x, ieee754dp y)
 313 {
 314         return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 315 }
 316
 317
 318 /* like strtod
 319 */
 320 ieee754dp ieee754dp_fstr(const char *s, char **endp);
 321 char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
 322
 323
 324 /* the control status register
 325 */
 326 struct ieee754_csr {
 327         unsigned pad:13;
 328         unsigned nod:1;         /* set 1 for no denormalised numbers */
 329         unsigned cx:5;          /* exceptions this operation */
 330         unsigned mx:5;          /* exception enable  mask */
 331         unsigned sx:5;          /* exceptions total */
 332         unsigned rm:2;          /* current rounding mode */
 333 };
 334 extern struct ieee754_csr ieee754_csr;
 335
 336 static __inline unsigned ieee754_getrm(void)
 337 {
 338         return (ieee754_csr.rm);
 339 }
 340 static __inline unsigned ieee754_setrm(unsigned rm)
 341 {
 342         return (ieee754_csr.rm = rm);
 343 }
 344
 345 /*
 346  * get current exceptions
 347  */
 348 static __inline unsigned ieee754_getcx(void)
 349 {
 350         return (ieee754_csr.cx);
 351 }
 352
 353 /* test for current exception condition
 354  */
 355 static __inline int ieee754_cxtest(unsigned n)
 356 {
 357         return (ieee754_csr.cx & n);
 358 }
 359
 360 /*
 361  * get sticky exceptions
 362  */
 363 static __inline unsigned ieee754_getsx(void)
 364 {
 365         return (ieee754_csr.sx);
 366 }
 367
 368 /* clear sticky conditions
 369 */
 370 static __inline unsigned ieee754_clrsx(void)
 371 {
 372         return (ieee754_csr.sx = 0);
 373 }
 374
 375 /* test for sticky exception condition
 376  */
 377 static __inline int ieee754_sxtest(unsigned n)
 378 {
 379         return (ieee754_csr.sx & n);
 380 }
 381
 382 /* debugging */
 383 ieee754sp ieee754sp_dump(char *s, ieee754sp x);
 384 ieee754dp ieee754dp_dump(char *s, ieee754dp x);
 385
 386 #define IEEE754_SPCVAL_PZERO    0
 387 #define IEEE754_SPCVAL_NZERO    1
 388 #define IEEE754_SPCVAL_PONE     2
 389 #define IEEE754_SPCVAL_NONE     3
 390 #define IEEE754_SPCVAL_PTEN     4
 391 #define IEEE754_SPCVAL_NTEN     5
 392 #define IEEE754_SPCVAL_PINFINITY        6
 393 #define IEEE754_SPCVAL_NINFINITY        7
 394 #define IEEE754_SPCVAL_INDEF    8
 395 #define IEEE754_SPCVAL_PMAX     9       /* +max norm */
 396 #define IEEE754_SPCVAL_NMAX     10      /* -max norm */
 397 #define IEEE754_SPCVAL_PMIN     11      /* +min norm */
 398 #define IEEE754_SPCVAL_NMIN     12      /* +min norm */
 399 #define IEEE754_SPCVAL_PMIND    13      /* +min denorm */
 400 #define IEEE754_SPCVAL_NMIND    14      /* +min denorm */
 401 #define IEEE754_SPCVAL_P1E31    15      /* + 1.0e31 */
 402 #define IEEE754_SPCVAL_P1E63    16      /* + 1.0e63 */
 403
 404 extern const struct ieee754dp_konst __ieee754dp_spcvals[];
 405 extern const struct ieee754sp_konst __ieee754sp_spcvals[];
 406 #define ieee754dp_spcvals ((const ieee754dp *)__ieee754dp_spcvals)
 407 #define ieee754sp_spcvals ((const ieee754sp *)__ieee754sp_spcvals)
 408
 409 /* return infinity with given sign
 410 */
 411 #define ieee754dp_inf(sn)       \
 412   (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 413 #define ieee754dp_zero(sn) \
 414   (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 415 #define ieee754dp_one(sn) \
 416   (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 417 #define ieee754dp_ten(sn) \
 418   (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 419 #define ieee754dp_indef() \
 420   (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
 421 #define ieee754dp_max(sn) \
 422   (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 423 #define ieee754dp_min(sn) \
 424   (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 425 #define ieee754dp_mind(sn) \
 426   (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 427 #define ieee754dp_1e31() \
 428   (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
 429 #define ieee754dp_1e63() \
 430   (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
 431
 432 #define ieee754sp_inf(sn) \
 433   (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
 434 #define ieee754sp_zero(sn) \
 435   (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
 436 #define ieee754sp_one(sn) \
 437   (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
 438 #define ieee754sp_ten(sn) \
 439   (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
 440 #define ieee754sp_indef() \
 441   (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
 442 #define ieee754sp_max(sn) \
 443   (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
 444 #define ieee754sp_min(sn) \
 445   (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
 446 #define ieee754sp_mind(sn) \
 447   (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
 448 #define ieee754sp_1e31() \
 449   (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
 450 #define ieee754sp_1e63() \
 451   (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
 452
 453 /* indefinite integer value
 454 */
 455 #define ieee754si_indef()       INT_MAX
 456 #ifdef LONG_LONG_MAX
 457 #define ieee754di_indef()       LONG_LONG_MAX
 458 #else
 459 #define ieee754di_indef()       ((s64)(~0ULL>>1))
 460 #endif
 461
 462 /* IEEE exception context, passed to handler */
 463 struct ieee754xctx {
 464         const char *op;         /* operation name */
 465         int rt;                 /* result type */
 466         union {
 467                 ieee754sp sp;   /* single precision */
 468                 ieee754dp dp;   /* double precision */
 469 #ifdef IEEE854_XP
 470                 ieee754xp xp;   /* extended precision */
 471 #endif
 472                 int si;         /* standard signed integer (32bits) */
 473                 s64 di;         /* extended signed integer (64bits) */
 474         } rv;                   /* default result format implied by op */
 475         va_list ap;
 476 };
 477
 478 /* result types for xctx.rt */
 479 #define IEEE754_RT_SP   0
 480 #define IEEE754_RT_DP   1
 481 #define IEEE754_RT_XP   2
 482 #define IEEE754_RT_SI   3
 483 #define IEEE754_RT_DI   4
 484
 485 extern void ieee754_xcpt(struct ieee754xctx *xcp);
 486
 487 /* compat */
 488 #define ieee754dp_fix(x)        ieee754dp_tint(x)
 489 #define ieee754sp_fix(x)        ieee754sp_tint(x)