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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         if (st0_tag == TAG_Valid) {
387                 reg_copy(st0_ptr, &tmp);
388                 exp = exponent(&tmp);
389
390                 if (exp < DOUBLE_Emin) {        /* It may be a denormal */
391                         addexponent(&tmp, -DOUBLE_Emin + 52);   /* largest exp to be 51 */
392
393                       denormal_arg:
394
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[0] = 0x00000000;      /* Set to */
481                                 l[1] = 0x7ff00000;      /* + 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                 l[0] = 0;
496                 l[1] = 0;
497         } else if (st0_tag == TAG_Special) {
498                 st0_tag = FPU_Special(st0_ptr);
499                 if (st0_tag == TW_Denormal) {
500                         /* A denormal will always underflow. */
501 #ifndef PECULIAR_486
502                         /* An 80486 is supposed to be able to generate
503                            a denormal exception here, but... */
504                         /* Underflow has priority. */
505                         if (control_word & CW_Underflow)
506                                 denormal_operand();
507 #endif /* PECULIAR_486 */
508                         reg_copy(st0_ptr, &tmp);
509                         goto denormal_arg;
510                 } else if (st0_tag == TW_Infinity) {
511                         l[0] = 0;
512                         l[1] = 0x7ff00000;
513                 } else if (st0_tag == TW_NaN) {
514                         /* Is it really a NaN ? */
515                         if ((exponent(st0_ptr) == EXP_OVER)
516                             && (st0_ptr->sigh & 0x80000000)) {
517                                 /* See if we can get a valid NaN from the FPU_REG */
518                                 l[0] =
519                                     (st0_ptr->sigl >> 11) | (st0_ptr->
520                                                              sigh << 21);
521                                 l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
522                                 if (!(st0_ptr->sigh & 0x40000000)) {
523                                         /* It is a signalling NaN */
524                                         EXCEPTION(EX_Invalid);
525                                         if (!(control_word & CW_Invalid))
526                                                 return 0;
527                                         l[1] |= (0x40000000 >> 11);
528                                 }
529                                 l[1] |= 0x7ff00000;
530                         } else {
531                                 /* It is an unsupported data type */
532                                 EXCEPTION(EX_Invalid);
533                                 if (!(control_word & CW_Invalid))
534                                         return 0;
535                                 l[0] = 0;
536                                 l[1] = 0xfff80000;
537                         }
538                 }
539         } else if (st0_tag == TAG_Empty) {
540                 /* Empty register (stack underflow) */
541                 EXCEPTION(EX_StackUnder);
542                 if (control_word & CW_Invalid) {
543                         /* The masked response */
544                         /* Put out the QNaN indefinite */
545                         RE_ENTRANT_CHECK_OFF;
546                         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
547                         FPU_put_user(0, (unsigned long __user *)dfloat);
548                         FPU_put_user(0xfff80000,
549                                      1 + (unsigned long __user *)dfloat);
550                         RE_ENTRANT_CHECK_ON;
551                         return 1;
552                 } else
553                         return 0;
554         }
555         if (getsign(st0_ptr))
556                 l[1] |= 0x80000000;
557
558         RE_ENTRANT_CHECK_OFF;
559         FPU_access_ok(VERIFY_WRITE, dfloat, 8);
560         FPU_put_user(l[0], (unsigned long __user *)dfloat);
561         FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
562         RE_ENTRANT_CHECK_ON;
563
564         return 1;
565 }
566
567 /* Put a float into user memory */
568 int FPU_store_single(FPU_REG * st0_ptr, u_char st0_tag, float __user * single)
569 {
570         long templ = 0;
571         unsigned long increment = 0;    /* avoid gcc warnings */
572         int precision_loss;
573         int exp;
574         FPU_REG tmp;
575
576         if (st0_tag == TAG_Valid) {
577
578                 reg_copy(st0_ptr, &tmp);
579                 exp = exponent(&tmp);
580
581                 if (exp < SINGLE_Emin) {
582                         addexponent(&tmp, -SINGLE_Emin + 23);   /* largest exp to be 22 */
583
584                       denormal_arg:
585
586                         if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
587 #ifdef PECULIAR_486
588                                 /* Did it round to a non-denormal ? */
589                                 /* This behaviour might be regarded as peculiar, it appears
590                                    that the 80486 rounds to the dest precision, then
591                                    converts to decide underflow. */
592                                 if (!((tmp.sigl == 0x00800000) &&
593                                       ((st0_ptr->sigh & 0x000000ff)
594                                        || st0_ptr->sigl)))
595 #endif /* PECULIAR_486 */
596                                 {
597                                         EXCEPTION(EX_Underflow);
598                                         /* This is a special case: see sec 16.2.5.1 of
599                                            the 80486 book */
600                                         if (!(control_word & CW_Underflow))
601                                                 return 0;
602                                 }
603                                 EXCEPTION(precision_loss);
604                                 if (!(control_word & CW_Precision))
605                                         return 0;
606                         }
607                         templ = tmp.sigl;
608                 } else {
609                         if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
610                                 unsigned long sigh = tmp.sigh;
611                                 unsigned long sigl = tmp.sigl;
612
613                                 precision_loss = 1;
614                                 switch (control_word & CW_RC) {
615                                 case RC_RND:
616                                         increment = ((sigh & 0xff) > 0x80)      /* more than half */
617                                             ||(((sigh & 0xff) == 0x80) && sigl) /* more than half */
618                                             ||((sigh & 0x180) == 0x180);        /* round to even */
619                                         break;
620                                 case RC_DOWN:   /* towards -infinity */
621                                         increment = signpositive(&tmp)
622                                             ? 0 : (sigl | (sigh & 0xff));
623                                         break;
624                                 case RC_UP:     /* towards +infinity */
625                                         increment = signpositive(&tmp)
626                                             ? (sigl | (sigh & 0xff)) : 0;
627                                         break;
628                                 case RC_CHOP:
629                                         increment = 0;
630                                         break;
631                                 }
632
633                                 /* Truncate part of the mantissa */
634                                 tmp.sigl = 0;
635
636                                 if (increment) {
637                                         if (sigh >= 0xffffff00) {
638                                                 /* The sigh part overflows */
639                                                 tmp.sigh = 0x80000000;
640                                                 exp++;
641                                                 if (exp >= EXP_OVER)
642                                                         goto overflow;
643                                         } else {
644                                                 tmp.sigh &= 0xffffff00;
645                                                 tmp.sigh += 0x100;
646                                         }
647                                 } else {
648                                         tmp.sigh &= 0xffffff00; /* Finish the truncation */
649                                 }
650                         } else
651                                 precision_loss = 0;
652
653                         templ = (tmp.sigh >> 8) & 0x007fffff;
654
655                         if (exp > SINGLE_Emax) {
656                               overflow:
657                                 EXCEPTION(EX_Overflow);
658                                 if (!(control_word & CW_Overflow))
659                                         return 0;
660                                 set_precision_flag_up();
661                                 if (!(control_word & CW_Precision))
662                                         return 0;
663
664                                 /* This is a special case: see sec 16.2.5.1 of the 80486 book. */
665                                 /* Masked response is overflow to infinity. */
666                                 templ = 0x7f800000;
667                         } else {
668                                 if (precision_loss) {
669                                         if (increment)
670                                                 set_precision_flag_up();
671                                         else
672                                                 set_precision_flag_down();
673                                 }
674                                 /* Add the exponent */
675                                 templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
676                         }
677                 }
678         } else if (st0_tag == TAG_Zero) {
679                 templ = 0;
680         } else if (st0_tag == TAG_Special) {
681                 st0_tag = FPU_Special(st0_ptr);
682                 if (st0_tag == TW_Denormal) {
683                         reg_copy(st0_ptr, &tmp);
684
685                         /* A denormal will always underflow. */
686 #ifndef PECULIAR_486
687                         /* An 80486 is supposed to be able to generate
688                            a denormal exception here, but... */
689                         /* Underflow has priority. */
690                         if (control_word & CW_Underflow)
691                                 denormal_operand();
692 #endif /* PECULIAR_486 */
693                         goto denormal_arg;
694                 } else if (st0_tag == TW_Infinity) {
695                         templ = 0x7f800000;
696                 } else if (st0_tag == TW_NaN) {
697                         /* Is it really a NaN ? */
698                         if ((exponent(st0_ptr) == EXP_OVER)
699                             && (st0_ptr->sigh & 0x80000000)) {
700                                 /* See if we can get a valid NaN from the FPU_REG */
701                                 templ = st0_ptr->sigh >> 8;
702                                 if (!(st0_ptr->sigh & 0x40000000)) {
703                                         /* It is a signalling NaN */
704                                         EXCEPTION(EX_Invalid);
705                                         if (!(control_word & CW_Invalid))
706                                                 return 0;
707                                         templ |= (0x40000000 >> 8);
708                                 }
709                                 templ |= 0x7f800000;
710                         } else {
711                                 /* It is an unsupported data type */
712                                 EXCEPTION(EX_Invalid);
713                                 if (!(control_word & CW_Invalid))
714                                         return 0;
715                                 templ = 0xffc00000;
716                         }
717                 }
718 #ifdef PARANOID
719                 else {
720                         EXCEPTION(EX_INTERNAL | 0x164);
721                         return 0;
722                 }
723 #endif
724         } else if (st0_tag == TAG_Empty) {
725                 /* Empty register (stack underflow) */
726                 EXCEPTION(EX_StackUnder);
727                 if (control_word & EX_Invalid) {
728                         /* The masked response */
729                         /* Put out the QNaN indefinite */
730                         RE_ENTRANT_CHECK_OFF;
731                         FPU_access_ok(VERIFY_WRITE, single, 4);
732                         FPU_put_user(0xffc00000,
733                                      (unsigned long __user *)single);
734                         RE_ENTRANT_CHECK_ON;
735                         return 1;
736                 } else
737                         return 0;
738         }
739 #ifdef PARANOID
740         else {
741                 EXCEPTION(EX_INTERNAL | 0x163);
742                 return 0;
743         }
744 #endif
745         if (getsign(st0_ptr))
746                 templ |= 0x80000000;
747
748         RE_ENTRANT_CHECK_OFF;
749         FPU_access_ok(VERIFY_WRITE, single, 4);
750         FPU_put_user(templ, (unsigned long __user *)single);
751         RE_ENTRANT_CHECK_ON;
752
753         return 1;
754 }
755
756 /* Put a long long into user memory */
757 int FPU_store_int64(FPU_REG * st0_ptr, u_char st0_tag, long long __user * d)
758 {
759         FPU_REG t;
760         long long tll;
761         int precision_loss;
762
763         if (st0_tag == TAG_Empty) {
764                 /* Empty register (stack underflow) */
765                 EXCEPTION(EX_StackUnder);
766                 goto invalid_operand;
767         } else if (st0_tag == TAG_Special) {
768                 st0_tag = FPU_Special(st0_ptr);
769                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
770                         EXCEPTION(EX_Invalid);
771                         goto invalid_operand;
772                 }
773         }
774
775         reg_copy(st0_ptr, &t);
776         precision_loss = FPU_round_to_int(&t, st0_tag);
777         ((long *)&tll)[0] = t.sigl;
778         ((long *)&tll)[1] = t.sigh;
779         if ((precision_loss == 1) ||
780             ((t.sigh & 0x80000000) &&
781              !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
782                 EXCEPTION(EX_Invalid);
783                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
784               invalid_operand:
785                 if (control_word & EX_Invalid) {
786                         /* Produce something like QNaN "indefinite" */
787                         tll = 0x8000000000000000LL;
788                 } else
789                         return 0;
790         } else {
791                 if (precision_loss)
792                         set_precision_flag(precision_loss);
793                 if (signnegative(&t))
794                         tll = -tll;
795         }
796
797         RE_ENTRANT_CHECK_OFF;
798         FPU_access_ok(VERIFY_WRITE, d, 8);
799         if (copy_to_user(d, &tll, 8))
800                 FPU_abort;
801         RE_ENTRANT_CHECK_ON;
802
803         return 1;
804 }
805
806 /* Put a long into user memory */
807 int FPU_store_int32(FPU_REG * st0_ptr, u_char st0_tag, long __user * d)
808 {
809         FPU_REG t;
810         int precision_loss;
811
812         if (st0_tag == TAG_Empty) {
813                 /* Empty register (stack underflow) */
814                 EXCEPTION(EX_StackUnder);
815                 goto invalid_operand;
816         } else if (st0_tag == TAG_Special) {
817                 st0_tag = FPU_Special(st0_ptr);
818                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
819                         EXCEPTION(EX_Invalid);
820                         goto invalid_operand;
821                 }
822         }
823
824         reg_copy(st0_ptr, &t);
825         precision_loss = FPU_round_to_int(&t, st0_tag);
826         if (t.sigh ||
827             ((t.sigl & 0x80000000) &&
828              !((t.sigl == 0x80000000) && signnegative(&t)))) {
829                 EXCEPTION(EX_Invalid);
830                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
831               invalid_operand:
832                 if (control_word & EX_Invalid) {
833                         /* Produce something like QNaN "indefinite" */
834                         t.sigl = 0x80000000;
835                 } else
836                         return 0;
837         } else {
838                 if (precision_loss)
839                         set_precision_flag(precision_loss);
840                 if (signnegative(&t))
841                         t.sigl = -(long)t.sigl;
842         }
843
844         RE_ENTRANT_CHECK_OFF;
845         FPU_access_ok(VERIFY_WRITE, d, 4);
846         FPU_put_user(t.sigl, (unsigned long __user *)d);
847         RE_ENTRANT_CHECK_ON;
848
849         return 1;
850 }
851
852 /* Put a short into user memory */
853 int FPU_store_int16(FPU_REG * st0_ptr, u_char st0_tag, short __user * d)
854 {
855         FPU_REG t;
856         int precision_loss;
857
858         if (st0_tag == TAG_Empty) {
859                 /* Empty register (stack underflow) */
860                 EXCEPTION(EX_StackUnder);
861                 goto invalid_operand;
862         } else if (st0_tag == TAG_Special) {
863                 st0_tag = FPU_Special(st0_ptr);
864                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
865                         EXCEPTION(EX_Invalid);
866                         goto invalid_operand;
867                 }
868         }
869
870         reg_copy(st0_ptr, &t);
871         precision_loss = FPU_round_to_int(&t, st0_tag);
872         if (t.sigh ||
873             ((t.sigl & 0xffff8000) &&
874              !((t.sigl == 0x8000) && signnegative(&t)))) {
875                 EXCEPTION(EX_Invalid);
876                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
877               invalid_operand:
878                 if (control_word & EX_Invalid) {
879                         /* Produce something like QNaN "indefinite" */
880                         t.sigl = 0x8000;
881                 } else
882                         return 0;
883         } else {
884                 if (precision_loss)
885                         set_precision_flag(precision_loss);
886                 if (signnegative(&t))
887                         t.sigl = -t.sigl;
888         }
889
890         RE_ENTRANT_CHECK_OFF;
891         FPU_access_ok(VERIFY_WRITE, d, 2);
892         FPU_put_user((short)t.sigl, d);
893         RE_ENTRANT_CHECK_ON;
894
895         return 1;
896 }
897
898 /* Put a packed bcd array into user memory */
899 int FPU_store_bcd(FPU_REG * st0_ptr, u_char st0_tag, u_char __user * d)
900 {
901         FPU_REG t;
902         unsigned long long ll;
903         u_char b;
904         int i, precision_loss;
905         u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;
906
907         if (st0_tag == TAG_Empty) {
908                 /* Empty register (stack underflow) */
909                 EXCEPTION(EX_StackUnder);
910                 goto invalid_operand;
911         } else if (st0_tag == TAG_Special) {
912                 st0_tag = FPU_Special(st0_ptr);
913                 if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
914                         EXCEPTION(EX_Invalid);
915                         goto invalid_operand;
916                 }
917         }
918
919         reg_copy(st0_ptr, &t);
920         precision_loss = FPU_round_to_int(&t, st0_tag);
921         ll = significand(&t);
922
923         /* Check for overflow, by comparing with 999999999999999999 decimal. */
924         if ((t.sigh > 0x0de0b6b3) ||
925             ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
926                 EXCEPTION(EX_Invalid);
927                 /* This is a special case: see sec 16.2.5.1 of the 80486 book */
928               invalid_operand:
929                 if (control_word & CW_Invalid) {
930                         /* Produce the QNaN "indefinite" */
931                         RE_ENTRANT_CHECK_OFF;
932                         FPU_access_ok(VERIFY_WRITE, d, 10);
933                         for (i = 0; i < 7; i++)
934                                 FPU_put_user(0, d + i); /* These bytes "undefined" */
935                         FPU_put_user(0xc0, d + 7);      /* This byte "undefined" */
936                         FPU_put_user(0xff, d + 8);
937                         FPU_put_user(0xff, d + 9);
938                         RE_ENTRANT_CHECK_ON;
939                         return 1;
940                 } else
941                         return 0;
942         } else if (precision_loss) {
943                 /* Precision loss doesn't stop the data transfer */
944                 set_precision_flag(precision_loss);
945         }
946
947         RE_ENTRANT_CHECK_OFF;
948         FPU_access_ok(VERIFY_WRITE, d, 10);
949         RE_ENTRANT_CHECK_ON;
950         for (i = 0; i < 9; i++) {
951                 b = FPU_div_small(&ll, 10);
952                 b |= (FPU_div_small(&ll, 10)) << 4;
953                 RE_ENTRANT_CHECK_OFF;
954                 FPU_put_user(b, d + i);
955                 RE_ENTRANT_CHECK_ON;
956         }
957         RE_ENTRANT_CHECK_OFF;
958         FPU_put_user(sign, d + 9);
959         RE_ENTRANT_CHECK_ON;
960
961         return 1;
962 }
963
964 /*===========================================================================*/
965
966 /* r gets mangled such that sig is int, sign: 
967    it is NOT normalized */
968 /* The return value (in eax) is zero if the result is exact,
969    if bits are changed due to rounding, truncation, etc, then
970    a non-zero value is returned */
971 /* Overflow is signalled by a non-zero return value (in eax).
972    In the case of overflow, the returned significand always has the
973    largest possible value */
974 int FPU_round_to_int(FPU_REG * r, u_char tag)
975 {
976         u_char very_big;
977         unsigned eax;
978
979         if (tag == TAG_Zero) {
980                 /* Make sure that zero is returned */
981                 significand(r) = 0;
982                 return 0;       /* o.k. */
983         }
984
985         if (exponent(r) > 63) {
986                 r->sigl = r->sigh = ~0; /* The largest representable number */
987                 return 1;       /* overflow */
988         }
989
990         eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
991         very_big = !(~(r->sigh) | ~(r->sigl));  /* test for 0xfff...fff */
992 #define half_or_more    (eax & 0x80000000)
993 #define frac_part       (eax)
994 #define more_than_half  ((eax & 0x80000001) == 0x80000001)
995         switch (control_word & CW_RC) {
996         case RC_RND:
997                 if (more_than_half      /* nearest */
998                     || (half_or_more && (r->sigl & 1))) {       /* odd -> even */
999                         if (very_big)
1000                                 return 1;       /* overflow */
1001                         significand(r)++;
1002                         return PRECISION_LOST_UP;
1003                 }
1004                 break;
1005         case RC_DOWN:
1006                 if (frac_part && getsign(r)) {
1007                         if (very_big)
1008                                 return 1;       /* overflow */
1009                         significand(r)++;
1010                         return PRECISION_LOST_UP;
1011                 }
1012                 break;
1013         case RC_UP:
1014                 if (frac_part && !getsign(r)) {
1015                         if (very_big)
1016                                 return 1;       /* overflow */
1017                         significand(r)++;
1018                         return PRECISION_LOST_UP;
1019                 }
1020                 break;
1021         case RC_CHOP:
1022                 break;
1023         }
1024
1025         return eax ? PRECISION_LOST_DOWN : 0;
1026
1027 }
1028
1029 /*===========================================================================*/
1030
1031 u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user * s)
1032 {
1033         unsigned short tag_word = 0;
1034         u_char tag;
1035         int i;
1036
1037         if ((addr_modes.default_mode == VM86) ||
1038             ((addr_modes.default_mode == PM16)
1039              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1040                 RE_ENTRANT_CHECK_OFF;
1041                 FPU_access_ok(VERIFY_READ, s, 0x0e);
1042                 FPU_get_user(control_word, (unsigned short __user *)s);
1043                 FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
1044                 FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
1045                 FPU_get_user(instruction_address.offset,
1046                              (unsigned short __user *)(s + 6));
1047                 FPU_get_user(instruction_address.selector,
1048                              (unsigned short __user *)(s + 8));
1049                 FPU_get_user(operand_address.offset,
1050                              (unsigned short __user *)(s + 0x0a));
1051                 FPU_get_user(operand_address.selector,
1052                              (unsigned short __user *)(s + 0x0c));
1053                 RE_ENTRANT_CHECK_ON;
1054                 s += 0x0e;
1055                 if (addr_modes.default_mode == VM86) {
1056                         instruction_address.offset
1057                             += (instruction_address.selector & 0xf000) << 4;
1058                         operand_address.offset +=
1059                             (operand_address.selector & 0xf000) << 4;
1060                 }
1061         } else {
1062                 RE_ENTRANT_CHECK_OFF;
1063                 FPU_access_ok(VERIFY_READ, s, 0x1c);
1064                 FPU_get_user(control_word, (unsigned short __user *)s);
1065                 FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
1066                 FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
1067                 FPU_get_user(instruction_address.offset,
1068                              (unsigned long __user *)(s + 0x0c));
1069                 FPU_get_user(instruction_address.selector,
1070                              (unsigned short __user *)(s + 0x10));
1071                 FPU_get_user(instruction_address.opcode,
1072                              (unsigned short __user *)(s + 0x12));
1073                 FPU_get_user(operand_address.offset,
1074                              (unsigned long __user *)(s + 0x14));
1075                 FPU_get_user(operand_address.selector,
1076                              (unsigned long __user *)(s + 0x18));
1077                 RE_ENTRANT_CHECK_ON;
1078                 s += 0x1c;
1079         }
1080
1081 #ifdef PECULIAR_486
1082         control_word &= ~0xe080;
1083 #endif /* PECULIAR_486 */
1084
1085         top = (partial_status >> SW_Top_Shift) & 7;
1086
1087         if (partial_status & ~control_word & CW_Exceptions)
1088                 partial_status |= (SW_Summary | SW_Backward);
1089         else
1090                 partial_status &= ~(SW_Summary | SW_Backward);
1091
1092         for (i = 0; i < 8; i++) {
1093                 tag = tag_word & 3;
1094                 tag_word >>= 2;
1095
1096                 if (tag == TAG_Empty)
1097                         /* New tag is empty.  Accept it */
1098                         FPU_settag(i, TAG_Empty);
1099                 else if (FPU_gettag(i) == TAG_Empty) {
1100                         /* Old tag is empty and new tag is not empty.  New tag is determined
1101                            by old reg contents */
1102                         if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
1103                                 if (!
1104                                     (fpu_register(i).sigl | fpu_register(i).
1105                                      sigh))
1106                                         FPU_settag(i, TAG_Zero);
1107                                 else
1108                                         FPU_settag(i, TAG_Special);
1109                         } else if (exponent(&fpu_register(i)) ==
1110                                    0x7fff - EXTENDED_Ebias) {
1111                                 FPU_settag(i, TAG_Special);
1112                         } else if (fpu_register(i).sigh & 0x80000000)
1113                                 FPU_settag(i, TAG_Valid);
1114                         else
1115                                 FPU_settag(i, TAG_Special);     /* An Un-normal */
1116                 }
1117                 /* Else old tag is not empty and new tag is not empty.  Old tag
1118                    remains correct */
1119         }
1120
1121         return s;
1122 }
1123
1124 void frstor(fpu_addr_modes addr_modes, u_char __user * data_address)
1125 {
1126         int i, regnr;
1127         u_char __user *s = fldenv(addr_modes, data_address);
1128         int offset = (top & 7) * 10, other = 80 - offset;
1129
1130         /* Copy all registers in stack order. */
1131         RE_ENTRANT_CHECK_OFF;
1132         FPU_access_ok(VERIFY_READ, s, 80);
1133         __copy_from_user(register_base + offset, s, other);
1134         if (offset)
1135                 __copy_from_user(register_base, s + other, offset);
1136         RE_ENTRANT_CHECK_ON;
1137
1138         for (i = 0; i < 8; i++) {
1139                 regnr = (i + top) & 7;
1140                 if (FPU_gettag(regnr) != TAG_Empty)
1141                         /* The loaded data over-rides all other cases. */
1142                         FPU_settag(regnr, FPU_tagof(&st(i)));
1143         }
1144
1145 }
1146
1147 u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user * d)
1148 {
1149         if ((addr_modes.default_mode == VM86) ||
1150             ((addr_modes.default_mode == PM16)
1151              ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
1152                 RE_ENTRANT_CHECK_OFF;
1153                 FPU_access_ok(VERIFY_WRITE, d, 14);
1154 #ifdef PECULIAR_486
1155                 FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
1156 #else
1157                 FPU_put_user(control_word, (unsigned short __user *)d);
1158 #endif /* PECULIAR_486 */
1159                 FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
1160                 FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
1161                 FPU_put_user(instruction_address.offset,
1162                              (unsigned short __user *)(d + 6));
1163                 FPU_put_user(operand_address.offset,
1164                              (unsigned short __user *)(d + 0x0a));
1165                 if (addr_modes.default_mode == VM86) {
1166                         FPU_put_user((instruction_address.
1167                                       offset & 0xf0000) >> 4,
1168                                      (unsigned short __user *)(d + 8));
1169                         FPU_put_user((operand_address.offset & 0xf0000) >> 4,
1170                                      (unsigned short __user *)(d + 0x0c));
1171                 } else {
1172                         FPU_put_user(instruction_address.selector,
1173                                      (unsigned short __user *)(d + 8));
1174                         FPU_put_user(operand_address.selector,
1175                                      (unsigned short __user *)(d + 0x0c));
1176                 }
1177                 RE_ENTRANT_CHECK_ON;
1178                 d += 0x0e;
1179         } else {
1180                 RE_ENTRANT_CHECK_OFF;
1181                 FPU_access_ok(VERIFY_WRITE, d, 7 * 4);
1182 #ifdef PECULIAR_486
1183                 control_word &= ~0xe080;
1184                 /* An 80486 sets nearly all of the reserved bits to 1. */
1185                 control_word |= 0xffff0040;
1186                 partial_status = status_word() | 0xffff0000;
1187                 fpu_tag_word |= 0xffff0000;
1188                 I387.soft.fcs &= ~0xf8000000;
1189                 I387.soft.fos |= 0xffff0000;
1190 #endif /* PECULIAR_486 */
1191                 if (__copy_to_user(d, &control_word, 7 * 4))
1192                         FPU_abort;
1193                 RE_ENTRANT_CHECK_ON;
1194                 d += 0x1c;
1195         }
1196
1197         control_word |= CW_Exceptions;
1198         partial_status &= ~(SW_Summary | SW_Backward);
1199
1200         return d;
1201 }
1202
1203 void fsave(fpu_addr_modes addr_modes, u_char __user * data_address)
1204 {
1205         u_char __user *d;
1206         int offset = (top & 7) * 10, other = 80 - offset;
1207
1208         d = fstenv(addr_modes, data_address);
1209
1210         RE_ENTRANT_CHECK_OFF;
1211         FPU_access_ok(VERIFY_WRITE, d, 80);
1212
1213         /* Copy all registers in stack order. */
1214         if (__copy_to_user(d, register_base + offset, other))
1215                 FPU_abort;
1216         if (offset)
1217                 if (__copy_to_user(d + other, register_base, offset))
1218                         FPU_abort;
1219         RE_ENTRANT_CHECK_ON;
1220
1221         finit();
1222 }
1223
1224 /*===========================================================================*/