arch/x86/math-emu/reg_ld_str.c

   1 /*---------------------------------------------------------------------------+
   2  |  reg_ld_str.c                                                             |
   3  |                                                                           |
   4  | All of the functions which transfer data between user memory and FPU_REGs.|
   5  |                                                                           |
   6  | Copyright (C) 1992,1993,1994,1996,1997                                    |
   7  |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
   8  |                  E-mail   billm@suburbia.net                              |
   9  |                                                                           |
  10  |                                                                           |
  11  +---------------------------------------------------------------------------*/
  12
  13 /*---------------------------------------------------------------------------+
  14  | Note:                                                                     |
  15  |    The file contains code which accesses user memory.                     |
  16  |    Emulator static data may change when user memory is accessed, due to   |
  17  |    other processes using the emulator while swapping is in progress.      |
  18  +---------------------------------------------------------------------------*/
  19
  20 #include "fpu_emu.h"
  21
  22 #include <asm/uaccess.h>
  23
  24 #include "fpu_system.h"
  25 #include "exception.h"
  26 #include "reg_constant.h"
  27 #include "control_w.h"
  28 #include "status_w.h"
  29
  30 #define DOUBLE_Emax 1023        /* largest valid exponent */
  31 #define DOUBLE_Ebias 1023
  32 #define DOUBLE_Emin (-1022)     /* smallest valid exponent */
  33
  34 #define SINGLE_Emax 127         /* largest valid exponent */
  35 #define SINGLE_Ebias 127
  36 #define SINGLE_Emin (-126)      /* smallest valid exponent */
  37
  38 static u_char normalize_no_excep(FPU_REG *r, int exp, int sign)
  39 {
  40         u_char tag;
  41
  42         setexponent16(r, exp);
  43
  44         tag = FPU_normalize_nuo(r);
  45         stdexp(r);
  46         if (sign)
  47                 setnegative(r);
  48
  49         return tag;
  50 }
  51
  52 int FPU_tagof(FPU_REG *ptr)
  53 {
  54         int exp;
  55
  56         exp = exponent16(ptr) & 0x7fff;
  57         if (exp == 0) {
  58                 if (!(ptr->sigh | ptr->sigl)) {
  59                         return TAG_Zero;
  60                 }
  61                 /* The number is a de-normal or pseudodenormal. */
  62                 return TAG_Special;
  63         }
  64
  65         if (exp == 0x7fff) {
  66                 /* Is an Infinity, a NaN, or an unsupported data type. */
  67                 return TAG_Special;
  68         }
  69
  70         if (!(ptr->sigh & 0x80000000)) {
  71                 /* Unsupported data type. */
  72                 /* Valid numbers have the ms bit set to 1. */
  73                 /* Unnormal. */
  74                 return TAG_Special;
  75         }
  76
  77         return TAG_Valid;
  78 }
  79
  80 /* Get a long double from user memory */
  81 int FPU_load_extended(long double __user *s, int stnr)
  82 {
  83         FPU_REG *sti_ptr = &st(stnr);
  84
  85         RE_ENTRANT_CHECK_OFF;
  86         FPU_access_ok(VERIFY_READ, s, 10);
  87         __copy_from_user(sti_ptr, s, 10);
  88         RE_ENTRANT_CHECK_ON;
  89
  90         return FPU_tagof(sti_ptr);
  91 }
  92
  93 /* Get a double from user memory */
  94 int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data)
  95 {
  96         int exp, tag, negative;
  97         unsigned m64, l64;
  98
  99         RE_ENTRANT_CHECK_OFF;
 100         FPU_access_ok(VERIFY_READ, dfloat, 8);
 101         FPU_get_user(m64, 1 + (unsigned long __user *)dfloat);
 102         FPU_get_user(l64, (unsigned long __user *)dfloat);
 103         RE_ENTRANT_CHECK_ON;
 104
 105         negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
 106         exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias;
 107         m64 &= 0xfffff;
 108         if (exp > DOUBLE_Emax + EXTENDED_Ebias) {
 109                 /* Infinity or NaN */
 110                 if ((m64 == 0) && (l64 == 0)) {
 111                         /* +- infinity */
 112                         loaded_data->sigh = 0x80000000;
 113                         loaded_data->sigl = 0x00000000;
 114                         exp = EXP_Infinity + EXTENDED_Ebias;
 115                         tag = TAG_Special;
 116                 } else {
 117                         /* Must be a signaling or quiet NaN */
 118                         exp = EXP_NaN + EXTENDED_Ebias;
 119                         loaded_data->sigh = (m64 << 11) | 0x80000000;
 120                         loaded_data->sigh |= l64 >> 21;
 121                         loaded_data->sigl = l64 << 11;
 122                         tag = TAG_Special;      /* The calling function must look for NaNs */
 123                 }
 124         } else if (exp < DOUBLE_Emin + EXTENDED_Ebias) {
 125                 /* Zero or de-normal */
 126                 if ((m64 == 0) && (l64 == 0)) {
 127                         /* Zero */
 128                         reg_copy(&CONST_Z, loaded_data);
 129                         exp = 0;
 130                         tag = TAG_Zero;
 131                 } else {
 132                         /* De-normal */
 133                         loaded_data->sigh = m64 << 11;
 134                         loaded_data->sigh |= l64 >> 21;
 135                         loaded_data->sigl = l64 << 11;
 136
 137                         return normalize_no_excep(loaded_data, DOUBLE_Emin,
 138                                                   negative)
 139                             | (denormal_operand() < 0 ? FPU_Exception : 0);
 140                 }
 141         } else {
 142                 loaded_data->sigh = (m64 << 11) | 0x80000000;
 143                 loaded_data->sigh |= l64 >> 21;
 144                 loaded_data->sigl = l64 << 11;
 145
 146                 tag = TAG_Valid;
 147         }
 148
 149         setexponent16(loaded_data, exp | negative);
 150
 151         return tag;
 152 }
 153
 154 /* Get a float from user memory */
 155 int FPU_load_single(float __user *single, FPU_REG *loaded_data)
 156 {
 157         unsigned m32;
 158         int exp, tag, negative;
 159
 160         RE_ENTRANT_CHECK_OFF;
 161         FPU_access_ok(VERIFY_READ, single, 4);
 162         FPU_get_user(m32, (unsigned long __user *)single);
 163         RE_ENTRANT_CHECK_ON;
 164
 165         negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
 166
 167         if (!(m32 & 0x7fffffff)) {
 168                 /* Zero */
 169                 reg_copy(&CONST_Z, loaded_data);
 170                 addexponent(loaded_data, negative);
 171                 return TAG_Zero;
 172         }
 173         exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias;
 174         m32 = (m32 & 0x7fffff) << 8;
 175         if (exp < SINGLE_Emin + EXTENDED_Ebias) {
 176                 /* De-normals */
 177                 loaded_data->sigh = m32;
 178                 loaded_data->sigl = 0;
 179
 180                 return normalize_no_excep(loaded_data, SINGLE_Emin, negative)
 181                     | (denormal_operand() < 0 ? FPU_Exception : 0);
 182         } else if (exp > SINGLE_Emax + EXTENDED_Ebias) {
 183                 /* Infinity or NaN */
 184                 if (m32 == 0) {
 185                         /* +- infinity */
 186                         loaded_data->sigh = 0x80000000;
 187                         loaded_data->sigl = 0x00000000;
 188                         exp = EXP_Infinity + EXTENDED_Ebias;
 189                         tag = TAG_Special;
 190                 } else {
 191                         /* Must be a signaling or quiet NaN */
 192                         exp = EXP_NaN + EXTENDED_Ebias;
 193                         loaded_data->sigh = m32 | 0x80000000;
 194                         loaded_data->sigl = 0;
 195                         tag = TAG_Special;      /* The calling function must look for NaNs */
 196                 }
 197         } else {
 198                 loaded_data->sigh = m32 | 0x80000000;
 199                 loaded_data->sigl = 0;
 200                 tag = TAG_Valid;
 201         }
 202
 203         setexponent16(loaded_data, exp | negative);     /* Set the sign. */
 204
 205         return tag;
 206 }
 207
 208 /* Get a long long from user memory */
 209 int FPU_load_int64(long long __user *_s)
 210 {
 211         long long s;
 212         int sign;
 213         FPU_REG *st0_ptr = &st(0);
 214
 215         RE_ENTRANT_CHECK_OFF;
 216         FPU_access_ok(VERIFY_READ, _s, 8);
 217         if (copy_from_user(&s, _s, 8))
 218                 FPU_abort;
 219         RE_ENTRANT_CHECK_ON;
 220
 221         if (s == 0) {
 222                 reg_copy(&CONST_Z, st0_ptr);
 223                 return TAG_Zero;
 224         }
 225
 226         if (s > 0)
 227                 sign = SIGN_Positive;
 228         else {
 229                 s = -s;
 230                 sign = SIGN_Negative;
 231         }
 232
 233         significand(st0_ptr) = s;
 234
 235         return normalize_no_excep(st0_ptr, 63, sign);
 236 }
 237
 238 /* Get a long from user memory */
 239 int FPU_load_int32(long __user *_s, FPU_REG *loaded_data)
 240 {
 241         long s;
 242         int negative;
 243
 244         RE_ENTRANT_CHECK_OFF;
 245         FPU_access_ok(VERIFY_READ, _s, 4);
 246         FPU_get_user(s, _s);
 247         RE_ENTRANT_CHECK_ON;
 248
 249         if (s == 0) {
 250                 reg_copy(&CONST_Z, loaded_data);
 251                 return TAG_Zero;
 252         }
 253
 254         if (s > 0)
 255                 negative = SIGN_Positive;
 256         else {
 257                 s = -s;
 258                 negative = SIGN_Negative;
 259         }
 260
 261         loaded_data->sigh = s;
 262         loaded_data->sigl = 0;
 263
 264         return normalize_no_excep(loaded_data, 31, negative);
 265 }
 266
 267 /* Get a short from user memory */
 268 int FPU_load_int16(short __user *_s, FPU_REG *loaded_data)
 269 {
 270         int s, negative;
 271
 272         RE_ENTRANT_CHECK_OFF;
 273         FPU_access_ok(VERIFY_READ, _s, 2);
 274         /* Cast as short to get the sign extended. */
 275         FPU_get_user(s, _s);
 276         RE_ENTRANT_CHECK_ON;
 277
 278         if (s == 0) {
 279                 reg_copy(&CONST_Z, loaded_data);
 280                 return TAG_Zero;
 281         }
 282
 283         if (s > 0)
 284                 negative = SIGN_Positive;
 285         else {
 286                 s = -s;
 287                 negative = SIGN_Negative;
 288         }
 289
 290         loaded_data->sigh = s << 16;
 291         loaded_data->sigl = 0;
 292
 293         return normalize_no_excep(loaded_data, 15, negative);
 294 }
 295
 296 /* Get a packed bcd array from user memory */
 297 int FPU_load_bcd(u_char __user *s)
 298 {
 299         FPU_REG *st0_ptr = &st(0);
 300         int pos;
 301         u_char bcd;
 302         long long l = 0;
 303         int sign;
 304
 305         RE_ENTRANT_CHECK_OFF;
 306         FPU_access_ok(VERIFY_READ, s, 10);
 307         RE_ENTRANT_CHECK_ON;
 308         for (pos = 8; pos >= 0; pos--) {
 309                 l *= 10;
 310                 RE_ENTRANT_CHECK_OFF;
 311                 FPU_get_user(bcd, s + pos);
 312                 RE_ENTRANT_CHECK_ON;
 313                 l += bcd >> 4;
 314                 l *= 10;
 315                 l += bcd & 0x0f;
 316         }
 317
 318         RE_ENTRANT_CHECK_OFF;
 319         FPU_get_user(sign, s + 9);
 320         sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive;
 321         RE_ENTRANT_CHECK_ON;
 322
 323         if (l == 0) {
 324                 reg_copy(&CONST_Z, st0_ptr);
 325                 addexponent(st0_ptr, sign);     /* Set the sign. */
 326                 return TAG_Zero;
 327         } else {
 328                 significand(st0_ptr) = l;
 329                 return normalize_no_excep(st0_ptr, 63, sign);
 330         }
 331 }
 332
 333 /*===========================================================================*/
 334
 335 /* Put a long double into user memory */
 336 int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag,
 337                        long double __user * d)
 338 {
 339         /*
 340            The only exception raised by an attempt to store to an
 341            extended format is the Invalid Stack exception, i.e.
 342            attempting to store from an empty register.
 343          */
 344
 345         if (st0_tag != TAG_Empty) {
 346                 RE_ENTRANT_CHECK_OFF;
 347                 FPU_access_ok(VERIFY_WRITE, d, 10);
 348
 349                 FPU_put_user(st0_ptr->sigl, (unsigned long __user *)d);
 350                 FPU_put_user(st0_ptr->sigh,
 351                              (unsigned long __user *)((u_char __user *) d + 4));
 352                 FPU_put_user(exponent16(st0_ptr),
 353                              (unsigned short __user *)((u_char __user *) d +
 354                                                        8));
 355                 RE_ENTRANT_CHECK_ON;
 356
 357                 return 1;
 358         }
 359
 360         /* Empty register (stack underflow) */
 361         EXCEPTION(EX_StackUnder);
 362         if (control_word & CW_Invalid) {
 363                 /* The masked response */
 364                 /* Put out the QNaN indefinite */
 365                 RE_ENTRANT_CHECK_OFF;
 366                 FPU_access_ok(VERIFY_WRITE, d, 10);
 367                 FPU_put_user(0, (unsigned long __user *)d);
 368                 FPU_put_user(0xc0000000, 1 + (unsigned long __user *)d);
 369                 FPU_put_user(0xffff, 4 + (short __user *)d);
 370                 RE_ENTRANT_CHECK_ON;
 371                 return 1;
 372         } else
 373                 return 0;
 374
 375 }
 376
 377 /* Put a double into user memory */
 378 int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat)
 379 {
 380         unsigned long l[2];
 381         unsigned long increment = 0;    /* avoid gcc warnings */
 382         int precision_loss;
 383         int exp;
 384         FPU_REG tmp;
 385
 386         l[0] = 0;
 387         l[1] = 0;
 388         if (st0_tag == TAG_Valid) {
 389                 reg_copy(st0_ptr, &tmp);
 390                 exp = exponent(&tmp);
 391
 392                 if (exp < DOUBLE_Emin) {        /* It may be a denormal */
 393                         addexponent(&tmp, -DOUBLE_Emin + 52);   /* largest exp to be 51 */
 394 denormal_arg:
 395                         if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
 396 #ifdef PECULIAR_486
 397                                 /* Did it round to a non-denormal ? */
 398                                 /* This behaviour might be regarded as peculiar, it appears
 399                                    that the 80486 rounds to the dest precision, then
 400                                    converts to decide underflow. */
 401                                 if (!
 402                                     ((tmp.sigh == 0x00100000) && (tmp.sigl == 0)
 403                                      && (st0_ptr->sigl & 0x000007ff)))
 404 #endif /* PECULIAR_486 */
 405                                 {
 406                                         EXCEPTION(EX_Underflow);
 407                                         /* This is a special case: see sec 16.2.5.1 of
 408                                            the 80486 book */
 409                                         if (!(control_word & CW_Underflow))
 410                                                 return 0;
 411                                 }
 412                                 EXCEPTION(precision_loss);
 413                                 if (!(control_word & CW_Precision))
 414                                         return 0;
 415                         }
 416                         l[0] = tmp.sigl;
 417                         l[1] = tmp.sigh;
 418                 } else {
 419                         if (tmp.sigl & 0x000007ff) {
 420                                 precision_loss = 1;
 421                                 switch (control_word & CW_RC) {
 422                                 case RC_RND:
 423                                         /* Rounding can get a little messy.. */
 424                                         increment = ((tmp.sigl & 0x7ff) > 0x400) |      /* nearest */
 425                                             ((tmp.sigl & 0xc00) == 0xc00);      /* odd -> even */
 426                                         break;
 427                                 case RC_DOWN:   /* towards -infinity */
 428                                         increment =
 429                                             signpositive(&tmp) ? 0 : tmp.
 430                                             sigl & 0x7ff;
 431                                         break;
 432                                 case RC_UP:     /* towards +infinity */
 433                                         increment =
 434                                             signpositive(&tmp) ? tmp.
 435                                             sigl & 0x7ff : 0;
 436                                         break;
 437                                 case RC_CHOP:
 438                                         increment = 0;
 439                                         break;
 440                                 }
 441
 442                                 /* Truncate the mantissa */
 443                                 tmp.sigl &= 0xfffff800;
 444
 445                                 if (increment) {
 446                                         if (tmp.sigl >= 0xfffff800) {
 447                                                 /* the sigl part overflows */
 448                                                 if (tmp.sigh == 0xffffffff) {
 449                                                         /* The sigh part overflows */
 450                                                         tmp.sigh = 0x80000000;
 451                                                         exp++;
 452                                                         if (exp >= EXP_OVER)
 453                                                                 goto overflow;
 454                                                 } else {
 455                                                         tmp.sigh++;
 456                                                 }
 457                                                 tmp.sigl = 0x00000000;
 458                                         } else {
 459                                                 /* We only need to increment sigl */
 460                                                 tmp.sigl += 0x00000800;
 461                                         }
 462                                 }
 463                         } else
 464                                 precision_loss = 0;
 465
 466                         l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21);
 467                         l[1] = ((tmp.sigh >> 11) & 0xfffff);
 468
 469                         if (exp > DOUBLE_Emax) {
 470                               overflow:
 471                                 EXCEPTION(EX_Overflow);
 472                                 if (!(control_word & CW_Overflow))
 473                                         return 0;
 474                                 set_precision_flag_up();
 475                                 if (!(control_word & CW_Precision))
 476                                         return 0;
 477
 478                                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
 479                                 /* Overflow to infinity */
 480                                 l[1] = 0x7ff00000;      /* Set to + INF */
 481                         } else {
 482                                 if (precision_loss) {
 483                                         if (increment)
 484                                                 set_precision_flag_up();
 485                                         else
 486                                                 set_precision_flag_down();
 487                                 }
 488                                 /* Add the exponent */
 489                                 l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20);
 490                         }
 491                 }
 492         } else if (st0_tag == TAG_Zero) {
 493                 /* Number is zero */
 494         } else if (st0_tag == TAG_Special) {
 495                 st0_tag = FPU_Special(st0_ptr);
 496                 if (st0_tag == TW_Denormal) {
 497                         /* A denormal will always underflow. */
 498 #ifndef PECULIAR_486
 499                         /* An 80486 is supposed to be able to generate
 500                            a denormal exception here, but... */
 501                         /* Underflow has priority. */
 502                         if (control_word & CW_Underflow)
 503                                 denormal_operand();
 504 #endif /* PECULIAR_486 */
 505                         reg_copy(st0_ptr, &tmp);
 506                         goto denormal_arg;
 507                 } else if (st0_tag == TW_Infinity) {
 508                         l[1] = 0x7ff00000;
 509                 } else if (st0_tag == TW_NaN) {
 510                         /* Is it really a NaN ? */
 511                         if ((exponent(st0_ptr) == EXP_OVER)
 512                             && (st0_ptr->sigh & 0x80000000)) {
 513                                 /* See if we can get a valid NaN from the FPU_REG */
 514                                 l[0] =
 515                                     (st0_ptr->sigl >> 11) | (st0_ptr->
 516                                                              sigh << 21);
 517                                 l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
 518                                 if (!(st0_ptr->sigh & 0x40000000)) {
 519                                         /* It is a signalling NaN */
 520                                         EXCEPTION(EX_Invalid);
 521                                         if (!(control_word & CW_Invalid))
 522                                                 return 0;
 523                                         l[1] |= (0x40000000 >> 11);
 524                                 }
 525                                 l[1] |= 0x7ff00000;
 526                         } else {
 527                                 /* It is an unsupported data type */
 528                                 EXCEPTION(EX_Invalid);
 529                                 if (!(control_word & CW_Invalid))
 530                                         return 0;
 531                                 l[1] = 0xfff80000;
 532                         }
 533                 }
 534         } else if (st0_tag == TAG_Empty) {
 535                 /* Empty register (stack underflow) */
 536                 EXCEPTION(EX_StackUnder);
 537                 if (control_word & CW_Invalid) {
 538                         /* The masked response */
 539                         /* Put out the QNaN indefinite */
 540                         RE_ENTRANT_CHECK_OFF;
 541                         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
 542                         FPU_put_user(0, (unsigned long __user *)dfloat);
 543                         FPU_put_user(0xfff80000,
 544                                      1 + (unsigned long __user *)dfloat);
 545                         RE_ENTRANT_CHECK_ON;
 546                         return 1;
 547                 } else
 548                         return 0;
 549         }
 550         if (getsign(st0_ptr))
 551                 l[1] |= 0x80000000;
 552
 553         RE_ENTRANT_CHECK_OFF;
 554         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
 555         FPU_put_user(l[0], (unsigned long __user *)dfloat);
 556         FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
 557         RE_ENTRANT_CHECK_ON;
 558
 559         return 1;
 560 }
 561
 562 /* Put a float into user memory */
 563 int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single)
 564 {
 565         long templ = 0;
 566         unsigned long increment = 0;    /* avoid gcc warnings */
 567         int precision_loss;
 568         int exp;
 569         FPU_REG tmp;
 570
 571         if (st0_tag == TAG_Valid) {
 572
 573                 reg_copy(st0_ptr, &tmp);
 574                 exp = exponent(&tmp);
 575
 576                 if (exp < SINGLE_Emin) {
 577                         addexponent(&tmp, -SINGLE_Emin + 23);   /* largest exp to be 22 */
 578
 579                       denormal_arg:
 580
 581                         if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
 582 #ifdef PECULIAR_486
 583                                 /* Did it round to a non-denormal ? */
 584                                 /* This behaviour might be regarded as peculiar, it appears
 585                                    that the 80486 rounds to the dest precision, then
 586                                    converts to decide underflow. */
 587                                 if (!((tmp.sigl == 0x00800000) &&
 588                                       ((st0_ptr->sigh & 0x000000ff)
 589                                        || st0_ptr->sigl)))
 590 #endif /* PECULIAR_486 */
 591                                 {
 592                                         EXCEPTION(EX_Underflow);
 593                                         /* This is a special case: see sec 16.2.5.1 of
 594                                            the 80486 book */
 595                                         if (!(control_word & CW_Underflow))
 596                                                 return 0;
 597                                 }
 598                                 EXCEPTION(precision_loss);
 599                                 if (!(control_word & CW_Precision))
 600                                         return 0;
 601                         }
 602                         templ = tmp.sigl;
 603                 } else {
 604                         if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
 605                                 unsigned long sigh = tmp.sigh;
 606                                 unsigned long sigl = tmp.sigl;
 607
 608                                 precision_loss = 1;
 609                                 switch (control_word & CW_RC) {
 610                                 case RC_RND:
 611                                         increment = ((sigh & 0xff) > 0x80)      /* more than half */
 612                                             ||(((sigh & 0xff) == 0x80) && sigl) /* more than half */
 613                                             ||((sigh & 0x180) == 0x180);        /* round to even */
 614                                         break;
 615                                 case RC_DOWN:   /* towards -infinity */
 616                                         increment = signpositive(&tmp)
 617                                             ? 0 : (sigl | (sigh & 0xff));
 618                                         break;
 619                                 case RC_UP:     /* towards +infinity */
 620                                         increment = signpositive(&tmp)
 621                                             ? (sigl | (sigh & 0xff)) : 0;
 622                                         break;
 623                                 case RC_CHOP:
 624                                         increment = 0;
 625                                         break;
 626                                 }
 627
 628                                 /* Truncate part of the mantissa */
 629                                 tmp.sigl = 0;
 630
 631                                 if (increment) {
 632                                         if (sigh >= 0xffffff00) {
 633                                                 /* The sigh part overflows */
 634                                                 tmp.sigh = 0x80000000;
 635                                                 exp++;
 636                                                 if (exp >= EXP_OVER)
 637                                                         goto overflow;
 638                                         } else {
 639                                                 tmp.sigh &= 0xffffff00;
 640                                                 tmp.sigh += 0x100;
 641                                         }
 642                                 } else {
 643                                         tmp.sigh &= 0xffffff00; /* Finish the truncation */
 644                                 }
 645                         } else
 646                                 precision_loss = 0;
 647
 648                         templ = (tmp.sigh >> 8) & 0x007fffff;
 649
 650                         if (exp > SINGLE_Emax) {
 651                               overflow:
 652                                 EXCEPTION(EX_Overflow);
 653                                 if (!(control_word & CW_Overflow))
 654                                         return 0;
 655                                 set_precision_flag_up();
 656                                 if (!(control_word & CW_Precision))
 657                                         return 0;
 658
 659                                 /* This is a special case: see sec 16.2.5.1 of the 80486 book. */
 660                                 /* Masked response is overflow to infinity. */
 661                                 templ = 0x7f800000;
 662                         } else {
 663                                 if (precision_loss) {
 664                                         if (increment)
 665                                                 set_precision_flag_up();
 666                                         else
 667                                                 set_precision_flag_down();
 668                                 }
 669                                 /* Add the exponent */
 670                                 templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
 671                         }
 672                 }
 673         } else if (st0_tag == TAG_Zero) {
 674                 templ = 0;
 675         } else if (st0_tag == TAG_Special) {
 676                 st0_tag = FPU_Special(st0_ptr);
 677                 if (st0_tag == TW_Denormal) {
 678                         reg_copy(st0_ptr, &tmp);
 679
 680                         /* A denormal will always underflow. */
 681 #ifndef PECULIAR_486
 682                         /* An 80486 is supposed to be able to generate
 683                            a denormal exception here, but... */
 684                         /* Underflow has priority. */
 685                         if (control_word & CW_Underflow)
 686                                 denormal_operand();
 687 #endif /* PECULIAR_486 */
 688                         goto denormal_arg;
 689                 } else if (st0_tag == TW_Infinity) {
 690                         templ = 0x7f800000;
 691                 } else if (st0_tag == TW_NaN) {
 692                         /* Is it really a NaN ? */
 693                         if ((exponent(st0_ptr) == EXP_OVER)
 694                             && (st0_ptr->sigh & 0x80000000)) {
 695                                 /* See if we can get a valid NaN from the FPU_REG */
 696                                 templ = st0_ptr->sigh >> 8;
 697                                 if (!(st0_ptr->sigh & 0x40000000)) {
 698                                         /* It is a signalling NaN */
 699                                         EXCEPTION(EX_Invalid);
 700                                         if (!(control_word & CW_Invalid))
 701                                                 return 0;
 702                                         templ |= (0x40000000 >> 8);
 703                                 }
 704                                 templ |= 0x7f800000;
 705                         } else {
 706                                 /* It is an unsupported data type */
 707                                 EXCEPTION(EX_Invalid);
 708                                 if (!(control_word & CW_Invalid))
 709                                         return 0;
 710                                 templ = 0xffc00000;
 711                         }
 712                 }
 713 #ifdef PARANOID
 714                 else {
 715                         EXCEPTION(EX_INTERNAL | 0x164);
 716                         return 0;
 717                 }
 718 #endif
 719         } else if (st0_tag == TAG_Empty) {
 720                 /* Empty register (stack underflow) */
 721                 EXCEPTION(EX_StackUnder);
 722                 if (control_word & EX_Invalid) {
 723                         /* The masked response */
 724                         /* Put out the QNaN indefinite */
 725                         RE_ENTRANT_CHECK_OFF;
 726                         FPU_access_ok(VERIFY_WRITE, single, 4);
 727                         FPU_put_user(0xffc00000,
 728                                      (unsigned long __user *)single);
 729                         RE_ENTRANT_CHECK_ON;
 730                         return 1;
 731                 } else
 732                         return 0;
 733         }
 734 #ifdef PARANOID
 735         else {
 736                 EXCEPTION(EX_INTERNAL | 0x163);
 737                 return 0;
 738         }
 739 #endif
 740         if (getsign(st0_ptr))
 741                 templ |= 0x80000000;
 742
 743         RE_ENTRANT_CHECK_OFF;
 744         FPU_access_ok(VERIFY_WRITE, single, 4);
 745         FPU_put_user(templ, (unsigned long __user *)single);
 746         RE_ENTRANT_CHECK_ON;
 747
 748         return 1;
 749 }
 750
 751 /* Put a long long into user memory */
 752 int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d)
 753 {
 754         FPU_REG t;
 755         long long tll;
 756         int precision_loss;
 757
 758         if (st0_tag == TAG_Empty) {
 759                 /* Empty register (stack underflow) */
 760                 EXCEPTION(EX_StackUnder);
 761                 goto invalid_operand;
 762         } else if (st0_tag == TAG_Special) {
 763                 st0_tag = FPU_Special(st0_ptr);
 764                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
 765                         EXCEPTION(EX_Invalid);
 766                         goto invalid_operand;
 767                 }
 768         }
 769
 770         reg_copy(st0_ptr, &t);
 771         precision_loss = FPU_round_to_int(&t, st0_tag);
 772         ((long *)&tll)[0] = t.sigl;
 773         ((long *)&tll)[1] = t.sigh;
 774         if ((precision_loss == 1) ||
 775             ((t.sigh & 0x80000000) &&
 776              !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
 777                 EXCEPTION(EX_Invalid);
 778                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
 779               invalid_operand:
 780                 if (control_word & EX_Invalid) {
 781                         /* Produce something like QNaN "indefinite" */
 782                         tll = 0x8000000000000000LL;
 783                 } else
 784                         return 0;
 785         } else {
 786                 if (precision_loss)
 787                         set_precision_flag(precision_loss);
 788                 if (signnegative(&t))
 789                         tll = -tll;
 790         }
 791
 792         RE_ENTRANT_CHECK_OFF;
 793         FPU_access_ok(VERIFY_WRITE, d, 8);
 794         if (copy_to_user(d, &tll, 8))
 795                 FPU_abort;
 796         RE_ENTRANT_CHECK_ON;
 797
 798         return 1;
 799 }
 800
 801 /* Put a long into user memory */
 802 int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d)
 803 {
 804         FPU_REG t;
 805         int precision_loss;
 806
 807         if (st0_tag == TAG_Empty) {
 808                 /* Empty register (stack underflow) */
 809                 EXCEPTION(EX_StackUnder);
 810                 goto invalid_operand;
 811         } else if (st0_tag == TAG_Special) {
 812                 st0_tag = FPU_Special(st0_ptr);
 813                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
 814                         EXCEPTION(EX_Invalid);
 815                         goto invalid_operand;
 816                 }
 817         }
 818
 819         reg_copy(st0_ptr, &t);
 820         precision_loss = FPU_round_to_int(&t, st0_tag);
 821         if (t.sigh ||
 822             ((t.sigl & 0x80000000) &&
 823              !((t.sigl == 0x80000000) && signnegative(&t)))) {
 824                 EXCEPTION(EX_Invalid);
 825                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
 826               invalid_operand:
 827                 if (control_word & EX_Invalid) {
 828                         /* Produce something like QNaN "indefinite" */
 829                         t.sigl = 0x80000000;
 830                 } else
 831                         return 0;
 832         } else {
 833                 if (precision_loss)
 834                         set_precision_flag(precision_loss);
 835                 if (signnegative(&t))
 836                         t.sigl = -(long)t.sigl;
 837         }
 838
 839         RE_ENTRANT_CHECK_OFF;
 840         FPU_access_ok(VERIFY_WRITE, d, 4);
 841         FPU_put_user(t.sigl, (unsigned long __user *)d);
 842         RE_ENTRANT_CHECK_ON;
 843
 844         return 1;
 845 }
 846
 847 /* Put a short into user memory */
 848 int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d)
 849 {
 850         FPU_REG t;
 851         int precision_loss;
 852
 853         if (st0_tag == TAG_Empty) {
 854                 /* Empty register (stack underflow) */
 855                 EXCEPTION(EX_StackUnder);
 856                 goto invalid_operand;
 857         } else if (st0_tag == TAG_Special) {
 858                 st0_tag = FPU_Special(st0_ptr);
 859                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
 860                         EXCEPTION(EX_Invalid);
 861                         goto invalid_operand;
 862                 }
 863         }
 864
 865         reg_copy(st0_ptr, &t);
 866         precision_loss = FPU_round_to_int(&t, st0_tag);
 867         if (t.sigh ||
 868             ((t.sigl & 0xffff8000) &&
 869              !((t.sigl == 0x8000) && signnegative(&t)))) {
 870                 EXCEPTION(EX_Invalid);
 871                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
 872               invalid_operand:
 873                 if (control_word & EX_Invalid) {
 874                         /* Produce something like QNaN "indefinite" */
 875                         t.sigl = 0x8000;
 876                 } else
 877                         return 0;
 878         } else {
 879                 if (precision_loss)
 880                         set_precision_flag(precision_loss);
 881                 if (signnegative(&t))
 882                         t.sigl = -t.sigl;
 883         }
 884
 885         RE_ENTRANT_CHECK_OFF;
 886         FPU_access_ok(VERIFY_WRITE, d, 2);
 887         FPU_put_user((short)t.sigl, d);
 888         RE_ENTRANT_CHECK_ON;
 889
 890         return 1;
 891 }
 892
 893 /* Put a packed bcd array into user memory */
 894 int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d)
 895 {
 896         FPU_REG t;
 897         unsigned long long ll;
 898         u_char b;
 899         int i, precision_loss;
 900         u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;
 901
 902         if (st0_tag == TAG_Empty) {
 903                 /* Empty register (stack underflow) */
 904                 EXCEPTION(EX_StackUnder);
 905                 goto invalid_operand;
 906         } else if (st0_tag == TAG_Special) {
 907                 st0_tag = FPU_Special(st0_ptr);
 908                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
 909                         EXCEPTION(EX_Invalid);
 910                         goto invalid_operand;
 911                 }
 912         }
 913
 914         reg_copy(st0_ptr, &t);
 915         precision_loss = FPU_round_to_int(&t, st0_tag);
 916         ll = significand(&t);
 917
 918         /* Check for overflow, by comparing with 999999999999999999 decimal. */
 919         if ((t.sigh > 0x0de0b6b3) ||
 920             ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
 921                 EXCEPTION(EX_Invalid);
 922                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
 923               invalid_operand:
 924                 if (control_word & CW_Invalid) {
 925                         /* Produce the QNaN "indefinite" */
 926                         RE_ENTRANT_CHECK_OFF;
 927                         FPU_access_ok(VERIFY_WRITE, d, 10);
 928                         for (i = 0; i < 7; i++)
 929                                 FPU_put_user(0, d + i); /* These bytes "undefined" */
 930                         FPU_put_user(0xc0, d + 7);      /* This byte "undefined" */
 931                         FPU_put_user(0xff, d + 8);
 932                         FPU_put_user(0xff, d + 9);
 933                         RE_ENTRANT_CHECK_ON;
 934                         return 1;
 935                 } else
 936                         return 0;
 937         } else if (precision_loss) {
 938                 /* Precision loss doesn't stop the data transfer */
 939                 set_precision_flag(precision_loss);
 940         }
 941
 942         RE_ENTRANT_CHECK_OFF;
 943         FPU_access_ok(VERIFY_WRITE, d, 10);
 944         RE_ENTRANT_CHECK_ON;
 945         for (i = 0; i < 9; i++) {
 946                 b = FPU_div_small(&ll, 10);
 947                 b |= (FPU_div_small(&ll, 10)) << 4;
 948                 RE_ENTRANT_CHECK_OFF;
 949                 FPU_put_user(b, d + i);
 950                 RE_ENTRANT_CHECK_ON;
 951         }
 952         RE_ENTRANT_CHECK_OFF;
 953         FPU_put_user(sign, d + 9);
 954         RE_ENTRANT_CHECK_ON;
 955
 956         return 1;
 957 }
 958
 959 /*===========================================================================*/
 960
 961 /* r gets mangled such that sig is int, sign:
 962    it is NOT normalized */
 963 /* The return value (in eax) is zero if the result is exact,
 964    if bits are changed due to rounding, truncation, etc, then
 965    a non-zero value is returned */
 966 /* Overflow is signalled by a non-zero return value (in eax).
 967    In the case of overflow, the returned significand always has the
 968    largest possible value */
 969 int FPU_round_to_int(FPU_REG *r, u_char tag)
 970 {
 971         u_char very_big;
 972         unsigned eax;
 973
 974         if (tag == TAG_Zero) {
 975                 /* Make sure that zero is returned */
 976                 significand(r) = 0;
 977                 return 0;       /* o.k. */
 978         }
 979
 980         if (exponent(r) > 63) {
 981                 r->sigl = r->sigh = ~0; /* The largest representable number */
 982                 return 1;       /* overflow */
 983         }
 984
 985         eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
 986         very_big = !(~(r->sigh) | ~(r->sigl));  /* test for 0xfff...fff */
 987 #define half_or_more    (eax & 0x80000000)
 988 #define frac_part       (eax)
 989 #define more_than_half  ((eax & 0x80000001) == 0x80000001)
 990         switch (control_word & CW_RC) {
 991         case RC_RND:
 992                 if (more_than_half      /* nearest */
 993                     || (half_or_more && (r->sigl & 1))) {       /* odd -> even */
 994                         if (very_big)
 995                                 return 1;       /* overflow */
 996                         significand(r)++;
 997                         return PRECISION_LOST_UP;
 998                 }
 999                 break;
1000         case RC_DOWN:
1001                 if (frac_part && getsign(r)) {
1002                         if (very_big)
1003                                 return 1;       /* overflow */
1004                         significand(r)++;
1005                         return PRECISION_LOST_UP;
1006                 }
1007                 break;
1008         case RC_UP:
1009                 if (frac_part && !getsign(r)) {
1010                         if (very_big)
1011                                 return 1;       /* overflow */
1012                         significand(r)++;
1013                         return PRECISION_LOST_UP;
1014                 }
1015                 break;
1016         case RC_CHOP:
1017                 break;
1018         }
1019
1020         return eax ? PRECISION_LOST_DOWN : 0;
1021
1022 }
1023
1024 /*===========================================================================*/
1025
1026 u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s)
1027 {
1028         unsigned short tag_word = 0;
1029         u_char tag;
1030         int i;
1031
1032         if ((addr_modes.default_mode == VM86) ||
1033             ((addr_modes.default_mode == PM16)
1034              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1035                 RE_ENTRANT_CHECK_OFF;
1036                 FPU_access_ok(VERIFY_READ, s, 0x0e);
1037                 FPU_get_user(control_word, (unsigned short __user *)s);
1038                 FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
1039                 FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
1040                 FPU_get_user(instruction_address.offset,
1041                              (unsigned short __user *)(s + 6));
1042                 FPU_get_user(instruction_address.selector,
1043                              (unsigned short __user *)(s + 8));
1044                 FPU_get_user(operand_address.offset,
1045                              (unsigned short __user *)(s + 0x0a));
1046                 FPU_get_user(operand_address.selector,
1047                              (unsigned short __user *)(s + 0x0c));
1048                 RE_ENTRANT_CHECK_ON;
1049                 s += 0x0e;
1050                 if (addr_modes.default_mode == VM86) {
1051                         instruction_address.offset
1052                             += (instruction_address.selector & 0xf000) << 4;
1053                         operand_address.offset +=
1054                             (operand_address.selector & 0xf000) << 4;
1055                 }
1056         } else {
1057                 RE_ENTRANT_CHECK_OFF;
1058                 FPU_access_ok(VERIFY_READ, s, 0x1c);
1059                 FPU_get_user(control_word, (unsigned short __user *)s);
1060                 FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
1061                 FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
1062                 FPU_get_user(instruction_address.offset,
1063                              (unsigned long __user *)(s + 0x0c));
1064                 FPU_get_user(instruction_address.selector,
1065                              (unsigned short __user *)(s + 0x10));
1066                 FPU_get_user(instruction_address.opcode,
1067                              (unsigned short __user *)(s + 0x12));
1068                 FPU_get_user(operand_address.offset,
1069                              (unsigned long __user *)(s + 0x14));
1070                 FPU_get_user(operand_address.selector,
1071                              (unsigned long __user *)(s + 0x18));
1072                 RE_ENTRANT_CHECK_ON;
1073                 s += 0x1c;
1074         }
1075
1076 #ifdef PECULIAR_486
1077         control_word &= ~0xe080;
1078 #endif /* PECULIAR_486 */
1079
1080         top = (partial_status >> SW_Top_Shift) & 7;
1081
1082         if (partial_status & ~control_word & CW_Exceptions)
1083                 partial_status |= (SW_Summary | SW_Backward);
1084         else
1085                 partial_status &= ~(SW_Summary | SW_Backward);
1086
1087         for (i = 0; i < 8; i++) {
1088                 tag = tag_word & 3;
1089                 tag_word >>= 2;
1090
1091                 if (tag == TAG_Empty)
1092                         /* New tag is empty.  Accept it */
1093                         FPU_settag(i, TAG_Empty);
1094                 else if (FPU_gettag(i) == TAG_Empty) {
1095                         /* Old tag is empty and new tag is not empty.  New tag is determined
1096                            by old reg contents */
1097                         if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
1098                                 if (!
1099                                     (fpu_register(i).sigl | fpu_register(i).
1100                                      sigh))
1101                                         FPU_settag(i, TAG_Zero);
1102                                 else
1103                                         FPU_settag(i, TAG_Special);
1104                         } else if (exponent(&fpu_register(i)) ==
1105                                    0x7fff - EXTENDED_Ebias) {
1106                                 FPU_settag(i, TAG_Special);
1107                         } else if (fpu_register(i).sigh & 0x80000000)
1108                                 FPU_settag(i, TAG_Valid);
1109                         else
1110                                 FPU_settag(i, TAG_Special);     /* An Un-normal */
1111                 }
1112                 /* Else old tag is not empty and new tag is not empty.  Old tag
1113                    remains correct */
1114         }
1115
1116         return s;
1117 }
1118
1119 void frstor(fpu_addr_modes addr_modes, u_char __user *data_address)
1120 {
1121         int i, regnr;
1122         u_char __user *s = fldenv(addr_modes, data_address);
1123         int offset = (top & 7) * 10, other = 80 - offset;
1124
1125         /* Copy all registers in stack order. */
1126         RE_ENTRANT_CHECK_OFF;
1127         FPU_access_ok(VERIFY_READ, s, 80);
1128         __copy_from_user(register_base + offset, s, other);
1129         if (offset)
1130                 __copy_from_user(register_base, s + other, offset);
1131         RE_ENTRANT_CHECK_ON;
1132
1133         for (i = 0; i < 8; i++) {
1134                 regnr = (i + top) & 7;
1135                 if (FPU_gettag(regnr) != TAG_Empty)
1136                         /* The loaded data over-rides all other cases. */
1137                         FPU_settag(regnr, FPU_tagof(&st(i)));
1138         }
1139
1140 }
1141
1142 u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
1143 {
1144         if ((addr_modes.default_mode == VM86) ||
1145             ((addr_modes.default_mode == PM16)
1146              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1147                 RE_ENTRANT_CHECK_OFF;
1148                 FPU_access_ok(VERIFY_WRITE, d, 14);
1149 #ifdef PECULIAR_486
1150                 FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
1151 #else
1152                 FPU_put_user(control_word, (unsigned short __user *)d);
1153 #endif /* PECULIAR_486 */
1154                 FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
1155                 FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
1156                 FPU_put_user(instruction_address.offset,
1157                              (unsigned short __user *)(d + 6));
1158                 FPU_put_user(operand_address.offset,
1159                              (unsigned short __user *)(d + 0x0a));
1160                 if (addr_modes.default_mode == VM86) {
1161                         FPU_put_user((instruction_address.
1162                                       offset & 0xf0000) >> 4,
1163                                      (unsigned short __user *)(d + 8));
1164                         FPU_put_user((operand_address.offset & 0xf0000) >> 4,
1165                                      (unsigned short __user *)(d + 0x0c));
1166                 } else {
1167                         FPU_put_user(instruction_address.selector,
1168                                      (unsigned short __user *)(d + 8));
1169                         FPU_put_user(operand_address.selector,
1170                                      (unsigned short __user *)(d + 0x0c));
1171                 }
1172                 RE_ENTRANT_CHECK_ON;
1173                 d += 0x0e;
1174         } else {
1175                 RE_ENTRANT_CHECK_OFF;
1176                 FPU_access_ok(VERIFY_WRITE, d, 7 * 4);
1177 #ifdef PECULIAR_486
1178                 control_word &= ~0xe080;
1179                 /* An 80486 sets nearly all of the reserved bits to 1. */
1180                 control_word |= 0xffff0040;
1181                 partial_status = status_word() | 0xffff0000;
1182                 fpu_tag_word |= 0xffff0000;
1183                 I387->soft.fcs &= ~0xf8000000;
1184                 I387->soft.fos |= 0xffff0000;
1185 #endif /* PECULIAR_486 */
1186                 if (__copy_to_user(d, &control_word, 7 * 4))
1187                         FPU_abort;
1188                 RE_ENTRANT_CHECK_ON;
1189                 d += 0x1c;
1190         }
1191
1192         control_word |= CW_Exceptions;
1193         partial_status &= ~(SW_Summary | SW_Backward);
1194
1195         return d;
1196 }
1197
1198 void fsave(fpu_addr_modes addr_modes, u_char __user *data_address)
1199 {
1200         u_char __user *d;
1201         int offset = (top & 7) * 10, other = 80 - offset;
1202
1203         d = fstenv(addr_modes, data_address);
1204
1205         RE_ENTRANT_CHECK_OFF;
1206         FPU_access_ok(VERIFY_WRITE, d, 80);
1207
1208         /* Copy all registers in stack order. */
1209         if (__copy_to_user(d, register_base + offset, other))
1210                 FPU_abort;
1211         if (offset)
1212                 if (__copy_to_user(d + other, register_base, offset))
1213                         FPU_abort;
1214         RE_ENTRANT_CHECK_ON;
1215
1216         finit();
1217 }
1218
1219 /*===========================================================================*/