LXR linux/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
  40struct ieee754dp_konst {
  41        unsigned mantlo:32;
  42        unsigned manthi:20;
  43        unsigned bexp:11;
  44        unsigned sign:1;
  45};
  46struct ieee754sp_konst {
  47        unsigned mant:23;
  48        unsigned bexp:8;
  49        unsigned sign:1;
  50};
  51
  52typedef 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
  63typedef union _ieee754sp {
  64        struct ieee754sp_konst parts;
  65        float f;
  66        u32 bits;
  67} ieee754sp;
  68#endif
  69
  70#ifdef __BIG_ENDIAN
  71struct ieee754dp_konst {
  72        unsigned sign:1;
  73        unsigned bexp:11;
  74        unsigned manthi:20;
  75        unsigned mantlo:32;
  76};
  77
  78typedef 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
  89struct ieee754sp_konst {
  90        unsigned sign:1;
  91        unsigned bexp:8;
  92        unsigned mant:23;
  93};
  94
  95typedef 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*/
 105int ieee754sp_finite(ieee754sp x);
 106int ieee754sp_class(ieee754sp x);
 107
 108ieee754sp ieee754sp_abs(ieee754sp x);
 109ieee754sp ieee754sp_neg(ieee754sp x);
 110ieee754sp ieee754sp_scalb(ieee754sp x, int);
 111ieee754sp ieee754sp_logb(ieee754sp x);
 112
 113/* x with sign of y */
 114ieee754sp ieee754sp_copysign(ieee754sp x, ieee754sp y);
 115
 116ieee754sp ieee754sp_add(ieee754sp x, ieee754sp y);
 117ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y);
 118ieee754sp ieee754sp_mul(ieee754sp x, ieee754sp y);
 119ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y);
 120
 121ieee754sp ieee754sp_fint(int x);
 122ieee754sp ieee754sp_funs(unsigned x);
 123ieee754sp ieee754sp_flong(s64 x);
 124ieee754sp ieee754sp_fulong(u64 x);
 125ieee754sp ieee754sp_fdp(ieee754dp x);
 126
 127int ieee754sp_tint(ieee754sp x);
 128unsigned int ieee754sp_tuns(ieee754sp x);
 129s64 ieee754sp_tlong(ieee754sp x);
 130u64 ieee754sp_tulong(ieee754sp x);
 131
 132int ieee754sp_cmp(ieee754sp x, ieee754sp y, int cop, int sig);
 133/*
 134 * basic sp math
 135 */
 136ieee754sp ieee754sp_modf(ieee754sp x, ieee754sp * ip);
 137ieee754sp ieee754sp_frexp(ieee754sp x, int *exp);
 138ieee754sp ieee754sp_ldexp(ieee754sp x, int exp);
 139
 140ieee754sp ieee754sp_ceil(ieee754sp x);
 141ieee754sp ieee754sp_floor(ieee754sp x);
 142ieee754sp ieee754sp_trunc(ieee754sp x);
 143
 144ieee754sp ieee754sp_sqrt(ieee754sp x);
 145
 146/*
 147 * double precision (often aka double)
 148*/
 149int ieee754dp_finite(ieee754dp x);
 150int ieee754dp_class(ieee754dp x);
 151
 152/* x with sign of y */
 153ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y);
 154
 155ieee754dp ieee754dp_add(ieee754dp x, ieee754dp y);
 156ieee754dp ieee754dp_sub(ieee754dp x, ieee754dp y);
 157ieee754dp ieee754dp_mul(ieee754dp x, ieee754dp y);
 158ieee754dp ieee754dp_div(ieee754dp x, ieee754dp y);
 159
 160ieee754dp ieee754dp_abs(ieee754dp x);
 161ieee754dp ieee754dp_neg(ieee754dp x);
 162ieee754dp ieee754dp_scalb(ieee754dp x, int);
 163
 164/* return exponent as integer in floating point format
 165 */
 166ieee754dp ieee754dp_logb(ieee754dp x);
 167
 168ieee754dp ieee754dp_fint(int x);
 169ieee754dp ieee754dp_funs(unsigned x);
 170ieee754dp ieee754dp_flong(s64 x);
 171ieee754dp ieee754dp_fulong(u64 x);
 172ieee754dp ieee754dp_fsp(ieee754sp x);
 173
 174ieee754dp ieee754dp_ceil(ieee754dp x);
 175ieee754dp ieee754dp_floor(ieee754dp x);
 176ieee754dp ieee754dp_trunc(ieee754dp x);
 177
 178int ieee754dp_tint(ieee754dp x);
 179unsigned int ieee754dp_tuns(ieee754dp x);
 180s64 ieee754dp_tlong(ieee754dp x);
 181u64 ieee754dp_tulong(ieee754dp x);
 182
 183int ieee754dp_cmp(ieee754dp x, ieee754dp y, int cop, int sig);
 184/*
 185 * basic sp math
 186 */
 187ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip);
 188ieee754dp ieee754dp_frexp(ieee754dp x, int *exp);
 189ieee754dp ieee754dp_ldexp(ieee754dp x, int exp);
 190
 191ieee754dp ieee754dp_ceil(ieee754dp x);
 192ieee754dp ieee754dp_floor(ieee754dp x);
 193ieee754dp ieee754dp_trunc(ieee754dp x);
 194
 195ieee754dp 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*/
 235static inline int ieee754sp_eq(ieee754sp x, ieee754sp y)
 236{
 237        return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
 238}
 239
 240static 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
 246static inline int ieee754sp_lt(ieee754sp x, ieee754sp y)
 247{
 248        return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
 249}
 250
 251static inline int ieee754sp_le(ieee754sp x, ieee754sp y)
 252{
 253        return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 254}
 255
 256static inline int ieee754sp_gt(ieee754sp x, ieee754sp y)
 257{
 258        return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
 259}
 260
 261
 262static inline int ieee754sp_ge(ieee754sp x, ieee754sp y)
 263{
 264        return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
 265}
 266
 267static inline int ieee754dp_eq(ieee754dp x, ieee754dp y)
 268{
 269        return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
 270}
 271
 272static 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
 278static inline int ieee754dp_lt(ieee754dp x, ieee754dp y)
 279{
 280        return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
 281}
 282
 283static inline int ieee754dp_le(ieee754dp x, ieee754dp y)
 284{
 285        return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
 286}
 287
 288static inline int ieee754dp_gt(ieee754dp x, ieee754dp y)
 289{
 290        return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
 291}
 292
 293static 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 */
 302ieee754dp ieee754dp_fstr(const char *s, char **endp);
 303char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af);
 304
 305
 306/*
 307 * The control status register
 308 */
 309struct _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
 333static inline unsigned ieee754_getrm(void)
 334{
 335        return (ieee754_csr.rm);
 336}
 337static inline unsigned ieee754_setrm(unsigned rm)
 338{
 339        return (ieee754_csr.rm = rm);
 340}
 341
 342/*
 343 * get current exceptions
 344 */
 345static inline unsigned ieee754_getcx(void)
 346{
 347        return (ieee754_csr.cx);
 348}
 349
 350/* test for current exception condition
 351 */
 352static inline int ieee754_cxtest(unsigned n)
 353{
 354        return (ieee754_csr.cx & n);
 355}
 356
 357/*
 358 * get sticky exceptions
 359 */
 360static inline unsigned ieee754_getsx(void)
 361{
 362        return (ieee754_csr.sx);
 363}
 364
 365/* clear sticky conditions
 366*/
 367static inline unsigned ieee754_clrsx(void)
 368{
 369        return (ieee754_csr.sx = 0);
 370}
 371
 372/* test for sticky exception condition
 373 */
 374static inline int ieee754_sxtest(unsigned n)
 375{
 376        return (ieee754_csr.sx & n);
 377}
 378
 379/* debugging */
 380ieee754sp ieee754sp_dump(char *s, ieee754sp x);
 381ieee754dp 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
 401extern const struct ieee754dp_konst __ieee754dp_spcvals[];
 402extern 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 */
 442struct 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
 464extern 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 */
 471