LXR linux/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
  41struct ieee754dp_konst {
  42        unsigned mantlo:32;
  43        unsigned manthi:20;
  44        unsigned bexp:11;
  45        unsigned sign:1;
  46};
  47struct ieee754sp_konst {
  48        unsigned mant:23;
  49        unsigned bexp:8;
  50        unsigned sign:1;
  51};
  52
  53typedef 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
  64typedef union _ieee754sp {
  65        struct ieee754sp_konst parts;
  66        float f;
  67        u32 bits;
  68} ieee754sp;
  69#endif
  70
  71#ifdef __BIG_ENDIAN
  72struct ieee754dp_konst {
  73        unsigned sign:1;
  74        unsigned bexp:11;
  75        unsigned manthi:20;
  76        unsigned mantlo:32;
  77};
  78
  79typedef 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
  90struct ieee754sp_konst {
  91        unsigned sign:1;
  92        unsigned bexp:8;
  93        unsigned mant:23;
  94};
  95
  96typedef 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*/
 106int ieee754sp_finite(ieee754sp x);
 107int ieee754sp_class(ieee754sp x);
 108
 109ieee754sp ieee754sp_abs(ieee754sp x);
 110ieee754sp ieee754sp_neg(ieee754sp x);
 111ieee754sp ieee754sp_scalb(ieee754sp x, int);
 112ieee754sp ieee754sp_logb(ieee754sp x);
 113
 114/* x with sign of y */
 115ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
 116
 117ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
 118ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
 119ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
 120ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
 121
 122ieee754sp ieee754sp_fint(int x);
 123ieee754sp ieee754sp_funs(unsigned x);
 124ieee754sp ieee754sp_flong(s64 x);
 125ieee754sp ieee754sp_fulong(u64 x);
 126ieee754sp ieee754sp_fdp(ieee754dp x);
 127
 128int ieee754sp_tint(ieee754sp x);
 129unsigned int ieee754sp_tuns(ieee754sp x);
 130s64 ieee754sp_tlong(ieee754sp x);
 131u64 ieee754sp_tulong(ieee754sp x);
 132
 133int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
 134/*
 135 * basic sp math
 136 */
 137ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
 138ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
 139ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
 140
 141ieee754sp ieee754sp_ceil(ieee754sp x);
 142ieee754sp ieee754sp_floor(ieee754sp x);
 143ieee754sp ieee754sp_trunc(ieee754sp x);
 144
 145ieee754sp ieee754sp_sqrt(ieee754sp x);
 146
 147/*
 148 * double precision (often aka double)
 149*/
 150int ieee754dp_finite(ieee754dp x);
 151int ieee754dp_class(ieee754dp x);
 152
 153/* x with sign of y */
 154ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
 155
 156ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
 157ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
 158ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
 159ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
 160
 161ieee754dp ieee754dp_abs(ieee754dp x);
 162ieee754dp ieee754dp_neg(ieee754dp x);
 163ieee754dp ieee754dp_scalb(ieee754dp x, int);
 164
 165/* return exponent as integer in floating point format
 166 */
 167ieee754dp ieee754dp_logb(ieee754dp x);
 168
 169ieee754dp ieee754dp_fint(int x);
 170ieee754dp ieee754dp_funs(unsigned x);
 171ieee754dp ieee754dp_flong(s64 x);
 172ieee754dp ieee754dp_fulong(u64 x);
 173ieee754dp ieee754dp_fsp(ieee754sp x);
 174
 175ieee754dp ieee754dp_ceil(ieee754dp x);
 176ieee754dp ieee754dp_floor(ieee754dp x);
 177ieee754dp ieee754dp_trunc(ieee754dp x);
 178
 179int ieee754dp_tint(ieee754dp x);
 180unsigned int ieee754dp_tuns(ieee754dp x);
 181s64 ieee754dp_tlong(ieee754dp x);
 182u64 ieee754dp_tulong(ieee754dp x);
 183
 184int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
 185/*
 186 * basic sp math
 187 */
 188ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
 189ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
 190ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
 191
 192ieee754dp ieee754dp_ceil(ieee754dp x);
 193ieee754dp ieee754dp_floor(ieee754dp x);
 194ieee754dp ieee754dp_trunc(ieee754dp x);
 195
 196ieee754dp 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*/
 236static inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
 237{
 238        return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
 239}
 240
 241static 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
 247static inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
 248{
 249        return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
 250}
 251
 252static inline int ieee754sp_le(ieee754sp x, ieee754sp y)
 253{
 254        return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 255}
 256
 257static inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
 258{
 259        return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
 260}
 261
 262
 263static inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
 264{
 265        return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 266}
 267
 268static inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
 269{
 270        return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
 271}
 272
 273static 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
 279static inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
 280{
 281        return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
 282}
 283
 284static inline int ieee754dp_le(ieee754dp x, ieee754dp y)
 285{
 286        return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 287}
 288
 289static inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
 290{
 291        return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
 292}
 293
 294static 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 */
 303ieee754dp ieee754dp_fstr(const char *s, char **endp);
 304char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
 305
 306
 307/*
 308 * The control status register
 309 */
 310struct _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
 334static inline unsigned ieee754_getrm(void)
 335{
 336        return (ieee754_csr.rm);
 337}
 338static inline unsigned ieee754_setrm(unsigned rm)
 339{
 340        return (ieee754_csr.rm = rm);
 341}
 342
 343/*
 344 * get current exceptions
 345 */
 346static inline unsigned ieee754_getcx(void)
 347{
 348        return (ieee754_csr.cx);
 349}
 350
 351/* test for current exception condition
 352 */
 353static inline int ieee754_cxtest(unsigned n)
 354{
 355        return (ieee754_csr.cx & n);
 356}
 357
 358/*
 359 * get sticky exceptions
 360 */
 361static inline unsigned ieee754_getsx(void)
 362{
 363        return (ieee754_csr.sx);
 364}
 365
 366/* clear sticky conditions
 367*/
 368static inline unsigned ieee754_clrsx(void)
 369{
 370        return (ieee754_csr.sx = 0);
 371}
 372
 373/* test for sticky exception condition
 374 */
 375static inline int ieee754_sxtest(unsigned n)
 376{
 377        return (ieee754_csr.sx & n);
 378}
 379
 380/* debugging */
 381ieee754sp ieee754sp_dump(char *s, ieee754sp x);
 382ieee754dp 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
 402extern const struct ieee754dp_konst __ieee754dp_spcvals[];
 403extern 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 */
 443struct 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
 465extern 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 */
 472