GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / math-emu / reg_ld_str.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*---------------------------------------------------------------------------+
3  |  reg_ld_str.c                                                             |
4  |                                                                           |
5  | All of the functions which transfer data between user memory and FPU_REGs.|
6  |                                                                           |
7  | Copyright (C) 1992,1993,1994,1996,1997                                    |
8  |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
9  |                  E-mail   billm@suburbia.net                              |
10  |                                                                           |
11  |                                                                           |
12  +---------------------------------------------------------------------------*/
13
14 /*---------------------------------------------------------------------------+
15  | Note:                                                                     |
16  |    The file contains code which accesses user memory.                     |
17  |    Emulator static data may change when user memory is accessed, due to   |
18  |    other processes using the emulator while swapping is in progress.      |
19  +---------------------------------------------------------------------------*/
20
21 #include "fpu_emu.h"
22
23 #include <linux/uaccess.h>
24
25 #include "fpu_system.h"
26 #include "exception.h"
27 #include "reg_constant.h"
28 #include "control_w.h"
29 #include "status_w.h"
30
31 #define DOUBLE_Emax 1023        /* largest valid exponent */
32 #define DOUBLE_Ebias 1023
33 #define DOUBLE_Emin (-1022)     /* smallest valid exponent */
34
35 #define SINGLE_Emax 127         /* largest valid exponent */
36 #define SINGLE_Ebias 127
37 #define SINGLE_Emin (-126)      /* smallest valid exponent */
38
39 static u_char normalize_no_excep(FPU_REG *r, int exp, int sign)
40 {
41         u_char tag;
42
43         setexponent16(r, exp);
44
45         tag = FPU_normalize_nuo(r);
46         stdexp(r);
47         if (sign)
48                 setnegative(r);
49
50         return tag;
51 }
52
53 int FPU_tagof(FPU_REG *ptr)
54 {
55         int exp;
56
57         exp = exponent16(ptr) & 0x7fff;
58         if (exp == 0) {
59                 if (!(ptr->sigh | ptr->sigl)) {
60                         return TAG_Zero;
61                 }
62                 /* The number is a de-normal or pseudodenormal. */
63                 return TAG_Special;
64         }
65
66         if (exp == 0x7fff) {
67                 /* Is an Infinity, a NaN, or an unsupported data type. */
68                 return TAG_Special;
69         }
70
71         if (!(ptr->sigh & 0x80000000)) {
72                 /* Unsupported data type. */
73                 /* Valid numbers have the ms bit set to 1. */
74                 /* Unnormal. */
75                 return TAG_Special;
76         }
77
78         return TAG_Valid;
79 }
80
81 /* Get a long double from user memory */
82 int FPU_load_extended(long double __user *s, int stnr)
83 {
84         FPU_REG *sti_ptr = &st(stnr);
85
86         RE_ENTRANT_CHECK_OFF;
87         FPU_access_ok(VERIFY_READ, s, 10);
88         __copy_from_user(sti_ptr, s, 10);
89         RE_ENTRANT_CHECK_ON;
90
91         return FPU_tagof(sti_ptr);
92 }
93
94 /* Get a double from user memory */
95 int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data)
96 {
97         int exp, tag, negative;
98         unsigned m64, l64;
99
100         RE_ENTRANT_CHECK_OFF;
101         FPU_access_ok(VERIFY_READ, dfloat, 8);
102         FPU_get_user(m64, 1 + (unsigned long __user *)dfloat);
103         FPU_get_user(l64, (unsigned long __user *)dfloat);
104         RE_ENTRANT_CHECK_ON;
105
106         negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
107         exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias;
108         m64 &= 0xfffff;
109         if (exp > DOUBLE_Emax + EXTENDED_Ebias) {
110                 /* Infinity or NaN */
111                 if ((m64 == 0) && (l64 == 0)) {
112                         /* +- infinity */
113                         loaded_data->sigh = 0x80000000;
114                         loaded_data->sigl = 0x00000000;
115                         exp = EXP_Infinity + EXTENDED_Ebias;
116                         tag = TAG_Special;
117                 } else {
118                         /* Must be a signaling or quiet NaN */
119                         exp = EXP_NaN + EXTENDED_Ebias;
120                         loaded_data->sigh = (m64 << 11) | 0x80000000;
121                         loaded_data->sigh |= l64 >> 21;
122                         loaded_data->sigl = l64 << 11;
123                         tag = TAG_Special;      /* The calling function must look for NaNs */
124                 }
125         } else if (exp < DOUBLE_Emin + EXTENDED_Ebias) {
126                 /* Zero or de-normal */
127                 if ((m64 == 0) && (l64 == 0)) {
128                         /* Zero */
129                         reg_copy(&CONST_Z, loaded_data);
130                         exp = 0;
131                         tag = TAG_Zero;
132                 } else {
133                         /* De-normal */
134                         loaded_data->sigh = m64 << 11;
135                         loaded_data->sigh |= l64 >> 21;
136                         loaded_data->sigl = l64 << 11;
137
138                         return normalize_no_excep(loaded_data, DOUBLE_Emin,
139                                                   negative)
140                             | (denormal_operand() < 0 ? FPU_Exception : 0);
141                 }
142         } else {
143                 loaded_data->sigh = (m64 << 11) | 0x80000000;
144                 loaded_data->sigh |= l64 >> 21;
145                 loaded_data->sigl = l64 << 11;
146
147                 tag = TAG_Valid;
148         }
149
150         setexponent16(loaded_data, exp | negative);
151
152         return tag;
153 }
154
155 /* Get a float from user memory */
156 int FPU_load_single(float __user *single, FPU_REG *loaded_data)
157 {
158         unsigned m32;
159         int exp, tag, negative;
160
161         RE_ENTRANT_CHECK_OFF;
162         FPU_access_ok(VERIFY_READ, single, 4);
163         FPU_get_user(m32, (unsigned long __user *)single);
164         RE_ENTRANT_CHECK_ON;
165
166         negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
167
168         if (!(m32 & 0x7fffffff)) {
169                 /* Zero */
170                 reg_copy(&CONST_Z, loaded_data);
171                 addexponent(loaded_data, negative);
172                 return TAG_Zero;
173         }
174         exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias;
175         m32 = (m32 & 0x7fffff) << 8;
176         if (exp < SINGLE_Emin + EXTENDED_Ebias) {
177                 /* De-normals */
178                 loaded_data->sigh = m32;
179                 loaded_data->sigl = 0;
180
181                 return normalize_no_excep(loaded_data, SINGLE_Emin, negative)
182                     | (denormal_operand() < 0 ? FPU_Exception : 0);
183         } else if (exp > SINGLE_Emax + EXTENDED_Ebias) {
184                 /* Infinity or NaN */
185                 if (m32 == 0) {
186                         /* +- infinity */
187                         loaded_data->sigh = 0x80000000;
188                         loaded_data->sigl = 0x00000000;
189                         exp = EXP_Infinity + EXTENDED_Ebias;
190                         tag = TAG_Special;
191                 } else {
192                         /* Must be a signaling or quiet NaN */
193                         exp = EXP_NaN + EXTENDED_Ebias;
194                         loaded_data->sigh = m32 | 0x80000000;
195                         loaded_data->sigl = 0;
196                         tag = TAG_Special;      /* The calling function must look for NaNs */
197                 }
198         } else {
199                 loaded_data->sigh = m32 | 0x80000000;
200                 loaded_data->sigl = 0;
201                 tag = TAG_Valid;
202         }
203
204         setexponent16(loaded_data, exp | negative);     /* Set the sign. */
205
206         return tag;
207 }
208
209 /* Get a long long from user memory */
210 int FPU_load_int64(long long __user *_s)
211 {
212         long long s;
213         int sign;
214         FPU_REG *st0_ptr = &st(0);
215
216         RE_ENTRANT_CHECK_OFF;
217         FPU_access_ok(VERIFY_READ, _s, 8);
218         if (copy_from_user(&s, _s, 8))
219                 FPU_abort;
220         RE_ENTRANT_CHECK_ON;
221
222         if (s == 0) {
223                 reg_copy(&CONST_Z, st0_ptr);
224                 return TAG_Zero;
225         }
226
227         if (s > 0)
228                 sign = SIGN_Positive;
229         else {
230                 s = -s;
231                 sign = SIGN_Negative;
232         }
233
234         significand(st0_ptr) = s;
235
236         return normalize_no_excep(st0_ptr, 63, sign);
237 }
238
239 /* Get a long from user memory */
240 int FPU_load_int32(long __user *_s, FPU_REG *loaded_data)
241 {
242         long s;
243         int negative;
244
245         RE_ENTRANT_CHECK_OFF;
246         FPU_access_ok(VERIFY_READ, _s, 4);
247         FPU_get_user(s, _s);
248         RE_ENTRANT_CHECK_ON;
249
250         if (s == 0) {
251                 reg_copy(&CONST_Z, loaded_data);
252                 return TAG_Zero;
253         }
254
255         if (s > 0)
256                 negative = SIGN_Positive;
257         else {
258                 s = -s;
259                 negative = SIGN_Negative;
260         }
261
262         loaded_data->sigh = s;
263         loaded_data->sigl = 0;
264
265         return normalize_no_excep(loaded_data, 31, negative);
266 }
267
268 /* Get a short from user memory */
269 int FPU_load_int16(short __user *_s, FPU_REG *loaded_data)
270 {
271         int s, negative;
272
273         RE_ENTRANT_CHECK_OFF;
274         FPU_access_ok(VERIFY_READ, _s, 2);
275         /* Cast as short to get the sign extended. */
276         FPU_get_user(s, _s);
277         RE_ENTRANT_CHECK_ON;
278
279         if (s == 0) {
280                 reg_copy(&CONST_Z, loaded_data);
281                 return TAG_Zero;
282         }
283
284         if (s > 0)
285                 negative = SIGN_Positive;
286         else {
287                 s = -s;
288                 negative = SIGN_Negative;
289         }
290
291         loaded_data->sigh = s << 16;
292         loaded_data->sigl = 0;
293
294         return normalize_no_excep(loaded_data, 15, negative);
295 }
296
297 /* Get a packed bcd array from user memory */
298 int FPU_load_bcd(u_char __user *s)
299 {
300         FPU_REG *st0_ptr = &st(0);
301         int pos;
302         u_char bcd;
303         long long l = 0;
304         int sign;
305
306         RE_ENTRANT_CHECK_OFF;
307         FPU_access_ok(VERIFY_READ, s, 10);
308         RE_ENTRANT_CHECK_ON;
309         for (pos = 8; pos >= 0; pos--) {
310                 l *= 10;
311                 RE_ENTRANT_CHECK_OFF;
312                 FPU_get_user(bcd, s + pos);
313                 RE_ENTRANT_CHECK_ON;
314                 l += bcd >> 4;
315                 l *= 10;
316                 l += bcd & 0x0f;
317         }
318
319         RE_ENTRANT_CHECK_OFF;
320         FPU_get_user(sign, s + 9);
321         sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive;
322         RE_ENTRANT_CHECK_ON;
323
324         if (l == 0) {
325                 reg_copy(&CONST_Z, st0_ptr);
326                 addexponent(st0_ptr, sign);     /* Set the sign. */
327                 return TAG_Zero;
328         } else {
329                 significand(st0_ptr) = l;
330                 return normalize_no_excep(st0_ptr, 63, sign);
331         }
332 }
333
334 /*===========================================================================*/
335
336 /* Put a long double into user memory */
337 int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag,
338                        long double __user * d)
339 {
340         /*
341            The only exception raised by an attempt to store to an
342            extended format is the Invalid Stack exception, i.e.
343            attempting to store from an empty register.
344          */
345
346         if (st0_tag != TAG_Empty) {
347                 RE_ENTRANT_CHECK_OFF;
348                 FPU_access_ok(VERIFY_WRITE, d, 10);
349
350                 FPU_put_user(st0_ptr->sigl, (unsigned long __user *)d);
351                 FPU_put_user(st0_ptr->sigh,
352                              (unsigned long __user *)((u_char __user *) d + 4));
353                 FPU_put_user(exponent16(st0_ptr),
354                              (unsigned short __user *)((u_char __user *) d +
355                                                        8));
356                 RE_ENTRANT_CHECK_ON;
357
358                 return 1;
359         }
360
361         /* Empty register (stack underflow) */
362         EXCEPTION(EX_StackUnder);
363         if (control_word & CW_Invalid) {
364                 /* The masked response */
365                 /* Put out the QNaN indefinite */
366                 RE_ENTRANT_CHECK_OFF;
367                 FPU_access_ok(VERIFY_WRITE, d, 10);
368                 FPU_put_user(0, (unsigned long __user *)d);
369                 FPU_put_user(0xc0000000, 1 + (unsigned long __user *)d);
370                 FPU_put_user(0xffff, 4 + (short __user *)d);
371                 RE_ENTRANT_CHECK_ON;
372                 return 1;
373         } else
374                 return 0;
375
376 }
377
378 /* Put a double into user memory */
379 int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat)
380 {
381         unsigned long l[2];
382         unsigned long increment = 0;    /* avoid gcc warnings */
383         int precision_loss;
384         int exp;
385         FPU_REG tmp;
386
387         l[0] = 0;
388         l[1] = 0;
389         if (st0_tag == TAG_Valid) {
390                 reg_copy(st0_ptr, &tmp);
391                 exp = exponent(&tmp);
392
393                 if (exp < DOUBLE_Emin) {        /* It may be a denormal */
394                         addexponent(&tmp, -DOUBLE_Emin + 52);   /* largest exp to be 51 */
395 denormal_arg:
396                         if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
397 #ifdef PECULIAR_486
398                                 /* Did it round to a non-denormal ? */
399                                 /* This behaviour might be regarded as peculiar, it appears
400                                    that the 80486 rounds to the dest precision, then
401                                    converts to decide underflow. */
402                                 if (!
403                                     ((tmp.sigh == 0x00100000) && (tmp.sigl == 0)
404                                      && (st0_ptr->sigl & 0x000007ff)))
405 #endif /* PECULIAR_486 */
406                                 {
407                                         EXCEPTION(EX_Underflow);
408                                         /* This is a special case: see sec 16.2.5.1 of
409                                            the 80486 book */
410                                         if (!(control_word & CW_Underflow))
411                                                 return 0;
412                                 }
413                                 EXCEPTION(precision_loss);
414                                 if (!(control_word & CW_Precision))
415                                         return 0;
416                         }
417                         l[0] = tmp.sigl;
418                         l[1] = tmp.sigh;
419                 } else {
420                         if (tmp.sigl & 0x000007ff) {
421                                 precision_loss = 1;
422                                 switch (control_word & CW_RC) {
423                                 case RC_RND:
424                                         /* Rounding can get a little messy.. */
425                                         increment = ((tmp.sigl & 0x7ff) > 0x400) |      /* nearest */
426                                             ((tmp.sigl & 0xc00) == 0xc00);      /* odd -> even */
427                                         break;
428                                 case RC_DOWN:   /* towards -infinity */
429                                         increment =
430                                             signpositive(&tmp) ? 0 : tmp.
431                                             sigl & 0x7ff;
432                                         break;
433                                 case RC_UP:     /* towards +infinity */
434                                         increment =
435                                             signpositive(&tmp) ? tmp.
436                                             sigl & 0x7ff : 0;
437                                         break;
438                                 case RC_CHOP:
439                                         increment = 0;
440                                         break;
441                                 }
442
443                                 /* Truncate the mantissa */
444                                 tmp.sigl &= 0xfffff800;
445
446                                 if (increment) {
447                                         if (tmp.sigl >= 0xfffff800) {
448                                                 /* the sigl part overflows */
449                                                 if (tmp.sigh == 0xffffffff) {
450                                                         /* The sigh part overflows */
451                                                         tmp.sigh = 0x80000000;
452                                                         exp++;
453                                                         if (exp >= EXP_OVER)
454                                                                 goto overflow;
455                                                 } else {
456                                                         tmp.sigh++;
457                                                 }
458                                                 tmp.sigl = 0x00000000;
459                                         } else {
460                                                 /* We only need to increment sigl */
461                                                 tmp.sigl += 0x00000800;
462                                         }
463                                 }
464                         } else
465                                 precision_loss = 0;
466
467                         l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21);
468                         l[1] = ((tmp.sigh >> 11) & 0xfffff);
469
470                         if (exp > DOUBLE_Emax) {
471                               overflow:
472                                 EXCEPTION(EX_Overflow);
473                                 if (!(control_word & CW_Overflow))
474                                         return 0;
475                                 set_precision_flag_up();
476                                 if (!(control_word & CW_Precision))
477                                         return 0;
478
479                                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
480                                 /* Overflow to infinity */
481                                 l[1] = 0x7ff00000;      /* Set to + INF */
482                         } else {
483                                 if (precision_loss) {
484                                         if (increment)
485                                                 set_precision_flag_up();
486                                         else
487                                                 set_precision_flag_down();
488                                 }
489                                 /* Add the exponent */
490                                 l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20);
491                         }
492                 }
493         } else if (st0_tag == TAG_Zero) {
494                 /* Number is zero */
495         } else if (st0_tag == TAG_Special) {
496                 st0_tag = FPU_Special(st0_ptr);
497                 if (st0_tag == TW_Denormal) {
498                         /* A denormal will always underflow. */
499 #ifndef PECULIAR_486
500                         /* An 80486 is supposed to be able to generate
501                            a denormal exception here, but... */
502                         /* Underflow has priority. */
503                         if (control_word & CW_Underflow)
504                                 denormal_operand();
505 #endif /* PECULIAR_486 */
506                         reg_copy(st0_ptr, &tmp);
507                         goto denormal_arg;
508                 } else if (st0_tag == TW_Infinity) {
509                         l[1] = 0x7ff00000;
510                 } else if (st0_tag == TW_NaN) {
511                         /* Is it really a NaN ? */
512                         if ((exponent(st0_ptr) == EXP_OVER)
513                             && (st0_ptr->sigh & 0x80000000)) {
514                                 /* See if we can get a valid NaN from the FPU_REG */
515                                 l[0] =
516                                     (st0_ptr->sigl >> 11) | (st0_ptr->
517                                                              sigh << 21);
518                                 l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
519                                 if (!(st0_ptr->sigh & 0x40000000)) {
520                                         /* It is a signalling NaN */
521                                         EXCEPTION(EX_Invalid);
522                                         if (!(control_word & CW_Invalid))
523                                                 return 0;
524                                         l[1] |= (0x40000000 >> 11);
525                                 }
526                                 l[1] |= 0x7ff00000;
527                         } else {
528                                 /* It is an unsupported data type */
529                                 EXCEPTION(EX_Invalid);
530                                 if (!(control_word & CW_Invalid))
531                                         return 0;
532                                 l[1] = 0xfff80000;
533                         }
534                 }
535         } else if (st0_tag == TAG_Empty) {
536                 /* Empty register (stack underflow) */
537                 EXCEPTION(EX_StackUnder);
538                 if (control_word & CW_Invalid) {
539                         /* The masked response */
540                         /* Put out the QNaN indefinite */
541                         RE_ENTRANT_CHECK_OFF;
542                         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
543                         FPU_put_user(0, (unsigned long __user *)dfloat);
544                         FPU_put_user(0xfff80000,
545                                      1 + (unsigned long __user *)dfloat);
546                         RE_ENTRANT_CHECK_ON;
547                         return 1;
548                 } else
549                         return 0;
550         }
551         if (getsign(st0_ptr))
552                 l[1] |= 0x80000000;
553
554         RE_ENTRANT_CHECK_OFF;
555         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
556         FPU_put_user(l[0], (unsigned long __user *)dfloat);
557         FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
558         RE_ENTRANT_CHECK_ON;
559
560         return 1;
561 }
562
563 /* Put a float into user memory */
564 int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single)
565 {
566         long templ = 0;
567         unsigned long increment = 0;    /* avoid gcc warnings */
568         int precision_loss;
569         int exp;
570         FPU_REG tmp;
571
572         if (st0_tag == TAG_Valid) {
573
574                 reg_copy(st0_ptr, &tmp);
575                 exp = exponent(&tmp);
576
577                 if (exp < SINGLE_Emin) {
578                         addexponent(&tmp, -SINGLE_Emin + 23);   /* largest exp to be 22 */
579
580                       denormal_arg:
581
582                         if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
583 #ifdef PECULIAR_486
584                                 /* Did it round to a non-denormal ? */
585                                 /* This behaviour might be regarded as peculiar, it appears
586                                    that the 80486 rounds to the dest precision, then
587                                    converts to decide underflow. */
588                                 if (!((tmp.sigl == 0x00800000) &&
589                                       ((st0_ptr->sigh & 0x000000ff)
590                                        || st0_ptr->sigl)))
591 #endif /* PECULIAR_486 */
592                                 {
593                                         EXCEPTION(EX_Underflow);
594                                         /* This is a special case: see sec 16.2.5.1 of
595                                            the 80486 book */
596                                         if (!(control_word & CW_Underflow))
597                                                 return 0;
598                                 }
599                                 EXCEPTION(precision_loss);
600                                 if (!(control_word & CW_Precision))
601                                         return 0;
602                         }
603                         templ = tmp.sigl;
604                 } else {
605                         if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
606                                 unsigned long sigh = tmp.sigh;
607                                 unsigned long sigl = tmp.sigl;
608
609                                 precision_loss = 1;
610                                 switch (control_word & CW_RC) {
611                                 case RC_RND:
612                                         increment = ((sigh & 0xff) > 0x80)      /* more than half */
613                                             ||(((sigh & 0xff) == 0x80) && sigl) /* more than half */
614                                             ||((sigh & 0x180) == 0x180);        /* round to even */
615                                         break;
616                                 case RC_DOWN:   /* towards -infinity */
617                                         increment = signpositive(&tmp)
618                                             ? 0 : (sigl | (sigh & 0xff));
619                                         break;
620                                 case RC_UP:     /* towards +infinity */
621                                         increment = signpositive(&tmp)
622                                             ? (sigl | (sigh & 0xff)) : 0;
623                                         break;
624                                 case RC_CHOP:
625                                         increment = 0;
626                                         break;
627                                 }
628
629                                 /* Truncate part of the mantissa */
630                                 tmp.sigl = 0;
631
632                                 if (increment) {
633                                         if (sigh >= 0xffffff00) {
634                                                 /* The sigh part overflows */
635                                                 tmp.sigh = 0x80000000;
636                                                 exp++;
637                                                 if (exp >= EXP_OVER)
638                                                         goto overflow;
639                                         } else {
640                                                 tmp.sigh &= 0xffffff00;
641                                                 tmp.sigh += 0x100;
642                                         }
643                                 } else {
644                                         tmp.sigh &= 0xffffff00; /* Finish the truncation */
645                                 }
646                         } else
647                                 precision_loss = 0;
648
649                         templ = (tmp.sigh >> 8) & 0x007fffff;
650
651                         if (exp > SINGLE_Emax) {
652                               overflow:
653                                 EXCEPTION(EX_Overflow);
654                                 if (!(control_word & CW_Overflow))
655                                         return 0;
656                                 set_precision_flag_up();
657                                 if (!(control_word & CW_Precision))
658                                         return 0;
659
660                                 /* This is a special case: see sec 16.2.5.1 of the 80486 book. */
661                                 /* Masked response is overflow to infinity. */
662                                 templ = 0x7f800000;
663                         } else {
664                                 if (precision_loss) {
665                                         if (increment)
666                                                 set_precision_flag_up();
667                                         else
668                                                 set_precision_flag_down();
669                                 }
670                                 /* Add the exponent */
671                                 templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
672                         }
673                 }
674         } else if (st0_tag == TAG_Zero) {
675                 templ = 0;
676         } else if (st0_tag == TAG_Special) {
677                 st0_tag = FPU_Special(st0_ptr);
678                 if (st0_tag == TW_Denormal) {
679                         reg_copy(st0_ptr, &tmp);
680
681                         /* A denormal will always underflow. */
682 #ifndef PECULIAR_486
683                         /* An 80486 is supposed to be able to generate
684                            a denormal exception here, but... */
685                         /* Underflow has priority. */
686                         if (control_word & CW_Underflow)
687                                 denormal_operand();
688 #endif /* PECULIAR_486 */
689                         goto denormal_arg;
690                 } else if (st0_tag == TW_Infinity) {
691                         templ = 0x7f800000;
692                 } else if (st0_tag == TW_NaN) {
693                         /* Is it really a NaN ? */
694                         if ((exponent(st0_ptr) == EXP_OVER)
695                             && (st0_ptr->sigh & 0x80000000)) {
696                                 /* See if we can get a valid NaN from the FPU_REG */
697                                 templ = st0_ptr->sigh >> 8;
698                                 if (!(st0_ptr->sigh & 0x40000000)) {
699                                         /* It is a signalling NaN */
700                                         EXCEPTION(EX_Invalid);
701                                         if (!(control_word & CW_Invalid))
702                                                 return 0;
703                                         templ |= (0x40000000 >> 8);
704                                 }
705                                 templ |= 0x7f800000;
706                         } else {
707                                 /* It is an unsupported data type */
708                                 EXCEPTION(EX_Invalid);
709                                 if (!(control_word & CW_Invalid))
710                                         return 0;
711                                 templ = 0xffc00000;
712                         }
713                 }
714 #ifdef PARANOID
715                 else {
716                         EXCEPTION(EX_INTERNAL | 0x164);
717                         return 0;
718                 }
719 #endif
720         } else if (st0_tag == TAG_Empty) {
721                 /* Empty register (stack underflow) */
722                 EXCEPTION(EX_StackUnder);
723                 if (control_word & EX_Invalid) {
724                         /* The masked response */
725                         /* Put out the QNaN indefinite */
726                         RE_ENTRANT_CHECK_OFF;
727                         FPU_access_ok(VERIFY_WRITE, single, 4);
728                         FPU_put_user(0xffc00000,
729                                      (unsigned long __user *)single);
730                         RE_ENTRANT_CHECK_ON;
731                         return 1;
732                 } else
733                         return 0;
734         }
735 #ifdef PARANOID
736         else {
737                 EXCEPTION(EX_INTERNAL | 0x163);
738                 return 0;
739         }
740 #endif
741         if (getsign(st0_ptr))
742                 templ |= 0x80000000;
743
744         RE_ENTRANT_CHECK_OFF;
745         FPU_access_ok(VERIFY_WRITE, single, 4);
746         FPU_put_user(templ, (unsigned long __user *)single);
747         RE_ENTRANT_CHECK_ON;
748
749         return 1;
750 }
751
752 /* Put a long long into user memory */
753 int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d)
754 {
755         FPU_REG t;
756         long long tll;
757         int precision_loss;
758
759         if (st0_tag == TAG_Empty) {
760                 /* Empty register (stack underflow) */
761                 EXCEPTION(EX_StackUnder);
762                 goto invalid_operand;
763         } else if (st0_tag == TAG_Special) {
764                 st0_tag = FPU_Special(st0_ptr);
765                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
766                         EXCEPTION(EX_Invalid);
767                         goto invalid_operand;
768                 }
769         }
770
771         reg_copy(st0_ptr, &t);
772         precision_loss = FPU_round_to_int(&t, st0_tag);
773         ((long *)&tll)[0] = t.sigl;
774         ((long *)&tll)[1] = t.sigh;
775         if ((precision_loss == 1) ||
776             ((t.sigh & 0x80000000) &&
777              !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
778                 EXCEPTION(EX_Invalid);
779                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
780               invalid_operand:
781                 if (control_word & EX_Invalid) {
782                         /* Produce something like QNaN "indefinite" */
783                         tll = 0x8000000000000000LL;
784                 } else
785                         return 0;
786         } else {
787                 if (precision_loss)
788                         set_precision_flag(precision_loss);
789                 if (signnegative(&t))
790                         tll = -tll;
791         }
792
793         RE_ENTRANT_CHECK_OFF;
794         FPU_access_ok(VERIFY_WRITE, d, 8);
795         if (copy_to_user(d, &tll, 8))
796                 FPU_abort;
797         RE_ENTRANT_CHECK_ON;
798
799         return 1;
800 }
801
802 /* Put a long into user memory */
803 int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d)
804 {
805         FPU_REG t;
806         int precision_loss;
807
808         if (st0_tag == TAG_Empty) {
809                 /* Empty register (stack underflow) */
810                 EXCEPTION(EX_StackUnder);
811                 goto invalid_operand;
812         } else if (st0_tag == TAG_Special) {
813                 st0_tag = FPU_Special(st0_ptr);
814                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
815                         EXCEPTION(EX_Invalid);
816                         goto invalid_operand;
817                 }
818         }
819
820         reg_copy(st0_ptr, &t);
821         precision_loss = FPU_round_to_int(&t, st0_tag);
822         if (t.sigh ||
823             ((t.sigl & 0x80000000) &&
824              !((t.sigl == 0x80000000) && signnegative(&t)))) {
825                 EXCEPTION(EX_Invalid);
826                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
827               invalid_operand:
828                 if (control_word & EX_Invalid) {
829                         /* Produce something like QNaN "indefinite" */
830                         t.sigl = 0x80000000;
831                 } else
832                         return 0;
833         } else {
834                 if (precision_loss)
835                         set_precision_flag(precision_loss);
836                 if (signnegative(&t))
837                         t.sigl = -(long)t.sigl;
838         }
839
840         RE_ENTRANT_CHECK_OFF;
841         FPU_access_ok(VERIFY_WRITE, d, 4);
842         FPU_put_user(t.sigl, (unsigned long __user *)d);
843         RE_ENTRANT_CHECK_ON;
844
845         return 1;
846 }
847
848 /* Put a short into user memory */
849 int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d)
850 {
851         FPU_REG t;
852         int precision_loss;
853
854         if (st0_tag == TAG_Empty) {
855                 /* Empty register (stack underflow) */
856                 EXCEPTION(EX_StackUnder);
857                 goto invalid_operand;
858         } else if (st0_tag == TAG_Special) {
859                 st0_tag = FPU_Special(st0_ptr);
860                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
861                         EXCEPTION(EX_Invalid);
862                         goto invalid_operand;
863                 }
864         }
865
866         reg_copy(st0_ptr, &t);
867         precision_loss = FPU_round_to_int(&t, st0_tag);
868         if (t.sigh ||
869             ((t.sigl & 0xffff8000) &&
870              !((t.sigl == 0x8000) && signnegative(&t)))) {
871                 EXCEPTION(EX_Invalid);
872                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
873               invalid_operand:
874                 if (control_word & EX_Invalid) {
875                         /* Produce something like QNaN "indefinite" */
876                         t.sigl = 0x8000;
877                 } else
878                         return 0;
879         } else {
880                 if (precision_loss)
881                         set_precision_flag(precision_loss);
882                 if (signnegative(&t))
883                         t.sigl = -t.sigl;
884         }
885
886         RE_ENTRANT_CHECK_OFF;
887         FPU_access_ok(VERIFY_WRITE, d, 2);
888         FPU_put_user((short)t.sigl, d);
889         RE_ENTRANT_CHECK_ON;
890
891         return 1;
892 }
893
894 /* Put a packed bcd array into user memory */
895 int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d)
896 {
897         FPU_REG t;
898         unsigned long long ll;
899         u_char b;
900         int i, precision_loss;
901         u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;
902
903         if (st0_tag == TAG_Empty) {
904                 /* Empty register (stack underflow) */
905                 EXCEPTION(EX_StackUnder);
906                 goto invalid_operand;
907         } else if (st0_tag == TAG_Special) {
908                 st0_tag = FPU_Special(st0_ptr);
909                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
910                         EXCEPTION(EX_Invalid);
911                         goto invalid_operand;
912                 }
913         }
914
915         reg_copy(st0_ptr, &t);
916         precision_loss = FPU_round_to_int(&t, st0_tag);
917         ll = significand(&t);
918
919         /* Check for overflow, by comparing with 999999999999999999 decimal. */
920         if ((t.sigh > 0x0de0b6b3) ||
921             ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
922                 EXCEPTION(EX_Invalid);
923                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
924               invalid_operand:
925                 if (control_word & CW_Invalid) {
926                         /* Produce the QNaN "indefinite" */
927                         RE_ENTRANT_CHECK_OFF;
928                         FPU_access_ok(VERIFY_WRITE, d, 10);
929                         for (i = 0; i < 7; i++)
930                                 FPU_put_user(0, d + i); /* These bytes "undefined" */
931                         FPU_put_user(0xc0, d + 7);      /* This byte "undefined" */
932                         FPU_put_user(0xff, d + 8);
933                         FPU_put_user(0xff, d + 9);
934                         RE_ENTRANT_CHECK_ON;
935                         return 1;
936                 } else
937                         return 0;
938         } else if (precision_loss) {
939                 /* Precision loss doesn't stop the data transfer */
940                 set_precision_flag(precision_loss);
941         }
942
943         RE_ENTRANT_CHECK_OFF;
944         FPU_access_ok(VERIFY_WRITE, d, 10);
945         RE_ENTRANT_CHECK_ON;
946         for (i = 0; i < 9; i++) {
947                 b = FPU_div_small(&ll, 10);
948                 b |= (FPU_div_small(&ll, 10)) << 4;
949                 RE_ENTRANT_CHECK_OFF;
950                 FPU_put_user(b, d + i);
951                 RE_ENTRANT_CHECK_ON;
952         }
953         RE_ENTRANT_CHECK_OFF;
954         FPU_put_user(sign, d + 9);
955         RE_ENTRANT_CHECK_ON;
956
957         return 1;
958 }
959
960 /*===========================================================================*/
961
962 /* r gets mangled such that sig is int, sign: 
963    it is NOT normalized */
964 /* The return value (in eax) is zero if the result is exact,
965    if bits are changed due to rounding, truncation, etc, then
966    a non-zero value is returned */
967 /* Overflow is signalled by a non-zero return value (in eax).
968    In the case of overflow, the returned significand always has the
969    largest possible value */
970 int FPU_round_to_int(FPU_REG *r, u_char tag)
971 {
972         u_char very_big;
973         unsigned eax;
974
975         if (tag == TAG_Zero) {
976                 /* Make sure that zero is returned */
977                 significand(r) = 0;
978                 return 0;       /* o.k. */
979         }
980
981         if (exponent(r) > 63) {
982                 r->sigl = r->sigh = ~0; /* The largest representable number */
983                 return 1;       /* overflow */
984         }
985
986         eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
987         very_big = !(~(r->sigh) | ~(r->sigl));  /* test for 0xfff...fff */
988 #define half_or_more    (eax & 0x80000000)
989 #define frac_part       (eax)
990 #define more_than_half  ((eax & 0x80000001) == 0x80000001)
991         switch (control_word & CW_RC) {
992         case RC_RND:
993                 if (more_than_half      /* nearest */
994                     || (half_or_more && (r->sigl & 1))) {       /* odd -> even */
995                         if (very_big)
996                                 return 1;       /* overflow */
997                         significand(r)++;
998                         return PRECISION_LOST_UP;
999                 }
1000                 break;
1001         case RC_DOWN:
1002                 if (frac_part && getsign(r)) {
1003                         if (very_big)
1004                                 return 1;       /* overflow */
1005                         significand(r)++;
1006                         return PRECISION_LOST_UP;
1007                 }
1008                 break;
1009         case RC_UP:
1010                 if (frac_part && !getsign(r)) {
1011                         if (very_big)
1012                                 return 1;       /* overflow */
1013                         significand(r)++;
1014                         return PRECISION_LOST_UP;
1015                 }
1016                 break;
1017         case RC_CHOP:
1018                 break;
1019         }
1020
1021         return eax ? PRECISION_LOST_DOWN : 0;
1022
1023 }
1024
1025 /*===========================================================================*/
1026
1027 u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s)
1028 {
1029         unsigned short tag_word = 0;
1030         u_char tag;
1031         int i;
1032
1033         if ((addr_modes.default_mode == VM86) ||
1034             ((addr_modes.default_mode == PM16)
1035              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1036                 RE_ENTRANT_CHECK_OFF;
1037                 FPU_access_ok(VERIFY_READ, s, 0x0e);
1038                 FPU_get_user(control_word, (unsigned short __user *)s);
1039                 FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
1040                 FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
1041                 FPU_get_user(instruction_address.offset,
1042                              (unsigned short __user *)(s + 6));
1043                 FPU_get_user(instruction_address.selector,
1044                              (unsigned short __user *)(s + 8));
1045                 FPU_get_user(operand_address.offset,
1046                              (unsigned short __user *)(s + 0x0a));
1047                 FPU_get_user(operand_address.selector,
1048                              (unsigned short __user *)(s + 0x0c));
1049                 RE_ENTRANT_CHECK_ON;
1050                 s += 0x0e;
1051                 if (addr_modes.default_mode == VM86) {
1052                         instruction_address.offset
1053                             += (instruction_address.selector & 0xf000) << 4;
1054                         operand_address.offset +=
1055                             (operand_address.selector & 0xf000) << 4;
1056                 }
1057         } else {
1058                 RE_ENTRANT_CHECK_OFF;
1059                 FPU_access_ok(VERIFY_READ, s, 0x1c);
1060                 FPU_get_user(control_word, (unsigned short __user *)s);
1061                 FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
1062                 FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
1063                 FPU_get_user(instruction_address.offset,
1064                              (unsigned long __user *)(s + 0x0c));
1065                 FPU_get_user(instruction_address.selector,
1066                              (unsigned short __user *)(s + 0x10));
1067                 FPU_get_user(instruction_address.opcode,
1068                              (unsigned short __user *)(s + 0x12));
1069                 FPU_get_user(operand_address.offset,
1070                              (unsigned long __user *)(s + 0x14));
1071                 FPU_get_user(operand_address.selector,
1072                              (unsigned long __user *)(s + 0x18));
1073                 RE_ENTRANT_CHECK_ON;
1074                 s += 0x1c;
1075         }
1076
1077 #ifdef PECULIAR_486
1078         control_word &= ~0xe080;
1079 #endif /* PECULIAR_486 */
1080
1081         top = (partial_status >> SW_Top_Shift) & 7;
1082
1083         if (partial_status & ~control_word & CW_Exceptions)
1084                 partial_status |= (SW_Summary | SW_Backward);
1085         else
1086                 partial_status &= ~(SW_Summary | SW_Backward);
1087
1088         for (i = 0; i < 8; i++) {
1089                 tag = tag_word & 3;
1090                 tag_word >>= 2;
1091
1092                 if (tag == TAG_Empty)
1093                         /* New tag is empty.  Accept it */
1094                         FPU_settag(i, TAG_Empty);
1095                 else if (FPU_gettag(i) == TAG_Empty) {
1096                         /* Old tag is empty and new tag is not empty.  New tag is determined
1097                            by old reg contents */
1098                         if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
1099                                 if (!
1100                                     (fpu_register(i).sigl | fpu_register(i).
1101                                      sigh))
1102                                         FPU_settag(i, TAG_Zero);
1103                                 else
1104                                         FPU_settag(i, TAG_Special);
1105                         } else if (exponent(&fpu_register(i)) ==
1106                                    0x7fff - EXTENDED_Ebias) {
1107                                 FPU_settag(i, TAG_Special);
1108                         } else if (fpu_register(i).sigh & 0x80000000)
1109                                 FPU_settag(i, TAG_Valid);
1110                         else
1111                                 FPU_settag(i, TAG_Special);     /* An Un-normal */
1112                 }
1113                 /* Else old tag is not empty and new tag is not empty.  Old tag
1114                    remains correct */
1115         }
1116
1117         return s;
1118 }
1119
1120 void frstor(fpu_addr_modes addr_modes, u_char __user *data_address)
1121 {
1122         int i, regnr;
1123         u_char __user *s = fldenv(addr_modes, data_address);
1124         int offset = (top & 7) * 10, other = 80 - offset;
1125
1126         /* Copy all registers in stack order. */
1127         RE_ENTRANT_CHECK_OFF;
1128         FPU_access_ok(VERIFY_READ, s, 80);
1129         __copy_from_user(register_base + offset, s, other);
1130         if (offset)
1131                 __copy_from_user(register_base, s + other, offset);
1132         RE_ENTRANT_CHECK_ON;
1133
1134         for (i = 0; i < 8; i++) {
1135                 regnr = (i + top) & 7;
1136                 if (FPU_gettag(regnr) != TAG_Empty)
1137                         /* The loaded data over-rides all other cases. */
1138                         FPU_settag(regnr, FPU_tagof(&st(i)));
1139         }
1140
1141 }
1142
1143 u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
1144 {
1145         if ((addr_modes.default_mode == VM86) ||
1146             ((addr_modes.default_mode == PM16)
1147              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1148                 RE_ENTRANT_CHECK_OFF;
1149                 FPU_access_ok(VERIFY_WRITE, d, 14);
1150 #ifdef PECULIAR_486
1151                 FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
1152 #else
1153                 FPU_put_user(control_word, (unsigned short __user *)d);
1154 #endif /* PECULIAR_486 */
1155                 FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
1156                 FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
1157                 FPU_put_user(instruction_address.offset,
1158                              (unsigned short __user *)(d + 6));
1159                 FPU_put_user(operand_address.offset,
1160                              (unsigned short __user *)(d + 0x0a));
1161                 if (addr_modes.default_mode == VM86) {
1162                         FPU_put_user((instruction_address.
1163                                       offset & 0xf0000) >> 4,
1164                                      (unsigned short __user *)(d + 8));
1165                         FPU_put_user((operand_address.offset & 0xf0000) >> 4,
1166                                      (unsigned short __user *)(d + 0x0c));
1167                 } else {
1168                         FPU_put_user(instruction_address.selector,
1169                                      (unsigned short __user *)(d + 8));
1170                         FPU_put_user(operand_address.selector,
1171                                      (unsigned short __user *)(d + 0x0c));
1172                 }
1173                 RE_ENTRANT_CHECK_ON;
1174                 d += 0x0e;
1175         } else {
1176                 RE_ENTRANT_CHECK_OFF;
1177                 FPU_access_ok(VERIFY_WRITE, d, 7 * 4);
1178 #ifdef PECULIAR_486
1179                 control_word &= ~0xe080;
1180                 /* An 80486 sets nearly all of the reserved bits to 1. */
1181                 control_word |= 0xffff0040;
1182                 partial_status = status_word() | 0xffff0000;
1183                 fpu_tag_word |= 0xffff0000;
1184                 I387->soft.fcs &= ~0xf8000000;
1185                 I387->soft.fos |= 0xffff0000;
1186 #endif /* PECULIAR_486 */
1187                 if (__copy_to_user(d, &control_word, 7 * 4))
1188                         FPU_abort;
1189                 RE_ENTRANT_CHECK_ON;
1190                 d += 0x1c;
1191         }
1192
1193         control_word |= CW_Exceptions;
1194         partial_status &= ~(SW_Summary | SW_Backward);
1195
1196         return d;
1197 }
1198
1199 void fsave(fpu_addr_modes addr_modes, u_char __user *data_address)
1200 {
1201         u_char __user *d;
1202         int offset = (top & 7) * 10, other = 80 - offset;
1203
1204         d = fstenv(addr_modes, data_address);
1205
1206         RE_ENTRANT_CHECK_OFF;
1207         FPU_access_ok(VERIFY_WRITE, d, 80);
1208
1209         /* Copy all registers in stack order. */
1210         if (__copy_to_user(d, register_base + offset, other))
1211                 FPU_abort;
1212         if (offset)
1213                 if (__copy_to_user(d + other, register_base, offset))
1214                         FPU_abort;
1215         RE_ENTRANT_CHECK_ON;
1216
1217         finit();
1218 }
1219
1220 /*===========================================================================*/