/home/lenb/src/to-linus-stable branch 'acpi-2.6.12'
[linux-2.6] / arch / arm / vfp / vfpdouble.c
1 /*
2  *  linux/arch/arm/vfp/vfpdouble.c
3  *
4  * This code is derived in part from John R. Housers softfloat library, which
5  * carries the following notice:
6  *
7  * ===========================================================================
8  * This C source file is part of the SoftFloat IEC/IEEE Floating-point
9  * Arithmetic Package, Release 2.
10  *
11  * Written by John R. Hauser.  This work was made possible in part by the
12  * International Computer Science Institute, located at Suite 600, 1947 Center
13  * Street, Berkeley, California 94704.  Funding was partially provided by the
14  * National Science Foundation under grant MIP-9311980.  The original version
15  * of this code was written as part of a project to build a fixed-point vector
16  * processor in collaboration with the University of California at Berkeley,
17  * overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
18  * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
19  * arithmetic/softfloat.html'.
20  *
21  * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
22  * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
23  * TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
24  * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
25  * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
26  *
27  * Derivative works are acceptable, even for commercial purposes, so long as
28  * (1) they include prominent notice that the work is derivative, and (2) they
29  * include prominent notice akin to these three paragraphs for those parts of
30  * this code that are retained.
31  * ===========================================================================
32  */
33 #include <linux/kernel.h>
34 #include <linux/bitops.h>
35
36 #include <asm/div64.h>
37 #include <asm/ptrace.h>
38 #include <asm/vfp.h>
39
40 #include "vfpinstr.h"
41 #include "vfp.h"
42
43 static struct vfp_double vfp_double_default_qnan = {
44         .exponent       = 2047,
45         .sign           = 0,
46         .significand    = VFP_DOUBLE_SIGNIFICAND_QNAN,
47 };
48
49 static void vfp_double_dump(const char *str, struct vfp_double *d)
50 {
51         pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n",
52                  str, d->sign != 0, d->exponent, d->significand);
53 }
54
55 static void vfp_double_normalise_denormal(struct vfp_double *vd)
56 {
57         int bits = 31 - fls(vd->significand >> 32);
58         if (bits == 31)
59                 bits = 62 - fls(vd->significand);
60
61         vfp_double_dump("normalise_denormal: in", vd);
62
63         if (bits) {
64                 vd->exponent -= bits - 1;
65                 vd->significand <<= bits;
66         }
67
68         vfp_double_dump("normalise_denormal: out", vd);
69 }
70
71 u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func)
72 {
73         u64 significand, incr;
74         int exponent, shift, underflow;
75         u32 rmode;
76
77         vfp_double_dump("pack: in", vd);
78
79         /*
80          * Infinities and NaNs are a special case.
81          */
82         if (vd->exponent == 2047 && (vd->significand == 0 || exceptions))
83                 goto pack;
84
85         /*
86          * Special-case zero.
87          */
88         if (vd->significand == 0) {
89                 vd->exponent = 0;
90                 goto pack;
91         }
92
93         exponent = vd->exponent;
94         significand = vd->significand;
95
96         shift = 32 - fls(significand >> 32);
97         if (shift == 32)
98                 shift = 64 - fls(significand);
99         if (shift) {
100                 exponent -= shift;
101                 significand <<= shift;
102         }
103
104 #ifdef DEBUG
105         vd->exponent = exponent;
106         vd->significand = significand;
107         vfp_double_dump("pack: normalised", vd);
108 #endif
109
110         /*
111          * Tiny number?
112          */
113         underflow = exponent < 0;
114         if (underflow) {
115                 significand = vfp_shiftright64jamming(significand, -exponent);
116                 exponent = 0;
117 #ifdef DEBUG
118                 vd->exponent = exponent;
119                 vd->significand = significand;
120                 vfp_double_dump("pack: tiny number", vd);
121 #endif
122                 if (!(significand & ((1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1)))
123                         underflow = 0;
124         }
125
126         /*
127          * Select rounding increment.
128          */
129         incr = 0;
130         rmode = fpscr & FPSCR_RMODE_MASK;
131
132         if (rmode == FPSCR_ROUND_NEAREST) {
133                 incr = 1ULL << VFP_DOUBLE_LOW_BITS;
134                 if ((significand & (1ULL << (VFP_DOUBLE_LOW_BITS + 1))) == 0)
135                         incr -= 1;
136         } else if (rmode == FPSCR_ROUND_TOZERO) {
137                 incr = 0;
138         } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vd->sign != 0))
139                 incr = (1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1;
140
141         pr_debug("VFP: rounding increment = 0x%08llx\n", incr);
142
143         /*
144          * Is our rounding going to overflow?
145          */
146         if ((significand + incr) < significand) {
147                 exponent += 1;
148                 significand = (significand >> 1) | (significand & 1);
149                 incr >>= 1;
150 #ifdef DEBUG
151                 vd->exponent = exponent;
152                 vd->significand = significand;
153                 vfp_double_dump("pack: overflow", vd);
154 #endif
155         }
156
157         /*
158          * If any of the low bits (which will be shifted out of the
159          * number) are non-zero, the result is inexact.
160          */
161         if (significand & ((1 << (VFP_DOUBLE_LOW_BITS + 1)) - 1))
162                 exceptions |= FPSCR_IXC;
163
164         /*
165          * Do our rounding.
166          */
167         significand += incr;
168
169         /*
170          * Infinity?
171          */
172         if (exponent >= 2046) {
173                 exceptions |= FPSCR_OFC | FPSCR_IXC;
174                 if (incr == 0) {
175                         vd->exponent = 2045;
176                         vd->significand = 0x7fffffffffffffffULL;
177                 } else {
178                         vd->exponent = 2047;            /* infinity */
179                         vd->significand = 0;
180                 }
181         } else {
182                 if (significand >> (VFP_DOUBLE_LOW_BITS + 1) == 0)
183                         exponent = 0;
184                 if (exponent || significand > 0x8000000000000000ULL)
185                         underflow = 0;
186                 if (underflow)
187                         exceptions |= FPSCR_UFC;
188                 vd->exponent = exponent;
189                 vd->significand = significand >> 1;
190         }
191
192  pack:
193         vfp_double_dump("pack: final", vd);
194         {
195                 s64 d = vfp_double_pack(vd);
196                 pr_debug("VFP: %s: d(d%d)=%016llx exceptions=%08x\n", func,
197                          dd, d, exceptions);
198                 vfp_put_double(dd, d);
199         }
200         return exceptions & ~VFP_NAN_FLAG;
201 }
202
203 /*
204  * Propagate the NaN, setting exceptions if it is signalling.
205  * 'n' is always a NaN.  'm' may be a number, NaN or infinity.
206  */
207 static u32
208 vfp_propagate_nan(struct vfp_double *vdd, struct vfp_double *vdn,
209                   struct vfp_double *vdm, u32 fpscr)
210 {
211         struct vfp_double *nan;
212         int tn, tm = 0;
213
214         tn = vfp_double_type(vdn);
215
216         if (vdm)
217                 tm = vfp_double_type(vdm);
218
219         if (fpscr & FPSCR_DEFAULT_NAN)
220                 /*
221                  * Default NaN mode - always returns a quiet NaN
222                  */
223                 nan = &vfp_double_default_qnan;
224         else {
225                 /*
226                  * Contemporary mode - select the first signalling
227                  * NAN, or if neither are signalling, the first
228                  * quiet NAN.
229                  */
230                 if (tn == VFP_SNAN || (tm != VFP_SNAN && tn == VFP_QNAN))
231                         nan = vdn;
232                 else
233                         nan = vdm;
234                 /*
235                  * Make the NaN quiet.
236                  */
237                 nan->significand |= VFP_DOUBLE_SIGNIFICAND_QNAN;
238         }
239
240         *vdd = *nan;
241
242         /*
243          * If one was a signalling NAN, raise invalid operation.
244          */
245         return tn == VFP_SNAN || tm == VFP_SNAN ? FPSCR_IOC : VFP_NAN_FLAG;
246 }
247
248 /*
249  * Extended operations
250  */
251 static u32 vfp_double_fabs(int dd, int unused, int dm, u32 fpscr)
252 {
253         vfp_put_double(dd, vfp_double_packed_abs(vfp_get_double(dm)));
254         return 0;
255 }
256
257 static u32 vfp_double_fcpy(int dd, int unused, int dm, u32 fpscr)
258 {
259         vfp_put_double(dd, vfp_get_double(dm));
260         return 0;
261 }
262
263 static u32 vfp_double_fneg(int dd, int unused, int dm, u32 fpscr)
264 {
265         vfp_put_double(dd, vfp_double_packed_negate(vfp_get_double(dm)));
266         return 0;
267 }
268
269 static u32 vfp_double_fsqrt(int dd, int unused, int dm, u32 fpscr)
270 {
271         struct vfp_double vdm, vdd;
272         int ret, tm;
273
274         vfp_double_unpack(&vdm, vfp_get_double(dm));
275         tm = vfp_double_type(&vdm);
276         if (tm & (VFP_NAN|VFP_INFINITY)) {
277                 struct vfp_double *vdp = &vdd;
278
279                 if (tm & VFP_NAN)
280                         ret = vfp_propagate_nan(vdp, &vdm, NULL, fpscr);
281                 else if (vdm.sign == 0) {
282  sqrt_copy:
283                         vdp = &vdm;
284                         ret = 0;
285                 } else {
286  sqrt_invalid:
287                         vdp = &vfp_double_default_qnan;
288                         ret = FPSCR_IOC;
289                 }
290                 vfp_put_double(dd, vfp_double_pack(vdp));
291                 return ret;
292         }
293
294         /*
295          * sqrt(+/- 0) == +/- 0
296          */
297         if (tm & VFP_ZERO)
298                 goto sqrt_copy;
299
300         /*
301          * Normalise a denormalised number
302          */
303         if (tm & VFP_DENORMAL)
304                 vfp_double_normalise_denormal(&vdm);
305
306         /*
307          * sqrt(<0) = invalid
308          */
309         if (vdm.sign)
310                 goto sqrt_invalid;
311
312         vfp_double_dump("sqrt", &vdm);
313
314         /*
315          * Estimate the square root.
316          */
317         vdd.sign = 0;
318         vdd.exponent = ((vdm.exponent - 1023) >> 1) + 1023;
319         vdd.significand = (u64)vfp_estimate_sqrt_significand(vdm.exponent, vdm.significand >> 32) << 31;
320
321         vfp_double_dump("sqrt estimate1", &vdd);
322
323         vdm.significand >>= 1 + (vdm.exponent & 1);
324         vdd.significand += 2 + vfp_estimate_div128to64(vdm.significand, 0, vdd.significand);
325
326         vfp_double_dump("sqrt estimate2", &vdd);
327
328         /*
329          * And now adjust.
330          */
331         if ((vdd.significand & VFP_DOUBLE_LOW_BITS_MASK) <= 5) {
332                 if (vdd.significand < 2) {
333                         vdd.significand = ~0ULL;
334                 } else {
335                         u64 termh, terml, remh, reml;
336                         vdm.significand <<= 2;
337                         mul64to128(&termh, &terml, vdd.significand, vdd.significand);
338                         sub128(&remh, &reml, vdm.significand, 0, termh, terml);
339                         while ((s64)remh < 0) {
340                                 vdd.significand -= 1;
341                                 shift64left(&termh, &terml, vdd.significand);
342                                 terml |= 1;
343                                 add128(&remh, &reml, remh, reml, termh, terml);
344                         }
345                         vdd.significand |= (remh | reml) != 0;
346                 }
347         }
348         vdd.significand = vfp_shiftright64jamming(vdd.significand, 1);
349
350         return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fsqrt");
351 }
352
353 /*
354  * Equal        := ZC
355  * Less than    := N
356  * Greater than := C
357  * Unordered    := CV
358  */
359 static u32 vfp_compare(int dd, int signal_on_qnan, int dm, u32 fpscr)
360 {
361         s64 d, m;
362         u32 ret = 0;
363
364         m = vfp_get_double(dm);
365         if (vfp_double_packed_exponent(m) == 2047 && vfp_double_packed_mantissa(m)) {
366                 ret |= FPSCR_C | FPSCR_V;
367                 if (signal_on_qnan || !(vfp_double_packed_mantissa(m) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1))))
368                         /*
369                          * Signalling NaN, or signalling on quiet NaN
370                          */
371                         ret |= FPSCR_IOC;
372         }
373
374         d = vfp_get_double(dd);
375         if (vfp_double_packed_exponent(d) == 2047 && vfp_double_packed_mantissa(d)) {
376                 ret |= FPSCR_C | FPSCR_V;
377                 if (signal_on_qnan || !(vfp_double_packed_mantissa(d) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1))))
378                         /*
379                          * Signalling NaN, or signalling on quiet NaN
380                          */
381                         ret |= FPSCR_IOC;
382         }
383
384         if (ret == 0) {
385                 if (d == m || vfp_double_packed_abs(d | m) == 0) {
386                         /*
387                          * equal
388                          */
389                         ret |= FPSCR_Z | FPSCR_C;
390                 } else if (vfp_double_packed_sign(d ^ m)) {
391                         /*
392                          * different signs
393                          */
394                         if (vfp_double_packed_sign(d))
395                                 /*
396                                  * d is negative, so d < m
397                                  */
398                                 ret |= FPSCR_N;
399                         else
400                                 /*
401                                  * d is positive, so d > m
402                                  */
403                                 ret |= FPSCR_C;
404                 } else if ((vfp_double_packed_sign(d) != 0) ^ (d < m)) {
405                         /*
406                          * d < m
407                          */
408                         ret |= FPSCR_N;
409                 } else if ((vfp_double_packed_sign(d) != 0) ^ (d > m)) {
410                         /*
411                          * d > m
412                          */
413                         ret |= FPSCR_C;
414                 }
415         }
416
417         return ret;
418 }
419
420 static u32 vfp_double_fcmp(int dd, int unused, int dm, u32 fpscr)
421 {
422         return vfp_compare(dd, 0, dm, fpscr);
423 }
424
425 static u32 vfp_double_fcmpe(int dd, int unused, int dm, u32 fpscr)
426 {
427         return vfp_compare(dd, 1, dm, fpscr);
428 }
429
430 static u32 vfp_double_fcmpz(int dd, int unused, int dm, u32 fpscr)
431 {
432         return vfp_compare(dd, 0, VFP_REG_ZERO, fpscr);
433 }
434
435 static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr)
436 {
437         return vfp_compare(dd, 1, VFP_REG_ZERO, fpscr);
438 }
439
440 static u32 vfp_double_fcvts(int sd, int unused, int dm, u32 fpscr)
441 {
442         struct vfp_double vdm;
443         struct vfp_single vsd;
444         int tm;
445         u32 exceptions = 0;
446
447         vfp_double_unpack(&vdm, vfp_get_double(dm));
448
449         tm = vfp_double_type(&vdm);
450
451         /*
452          * If we have a signalling NaN, signal invalid operation.
453          */
454         if (tm == VFP_SNAN)
455                 exceptions = FPSCR_IOC;
456
457         if (tm & VFP_DENORMAL)
458                 vfp_double_normalise_denormal(&vdm);
459
460         vsd.sign = vdm.sign;
461         vsd.significand = vfp_hi64to32jamming(vdm.significand);
462
463         /*
464          * If we have an infinity or a NaN, the exponent must be 255
465          */
466         if (tm & (VFP_INFINITY|VFP_NAN)) {
467                 vsd.exponent = 255;
468                 if (tm & VFP_NAN)
469                         vsd.significand |= VFP_SINGLE_SIGNIFICAND_QNAN;
470                 goto pack_nan;
471         } else if (tm & VFP_ZERO)
472                 vsd.exponent = 0;
473         else
474                 vsd.exponent = vdm.exponent - (1023 - 127);
475
476         return vfp_single_normaliseround(sd, &vsd, fpscr, exceptions, "fcvts");
477
478  pack_nan:
479         vfp_put_float(sd, vfp_single_pack(&vsd));
480         return exceptions;
481 }
482
483 static u32 vfp_double_fuito(int dd, int unused, int dm, u32 fpscr)
484 {
485         struct vfp_double vdm;
486         u32 m = vfp_get_float(dm);
487
488         vdm.sign = 0;
489         vdm.exponent = 1023 + 63 - 1;
490         vdm.significand = (u64)m;
491
492         return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fuito");
493 }
494
495 static u32 vfp_double_fsito(int dd, int unused, int dm, u32 fpscr)
496 {
497         struct vfp_double vdm;
498         u32 m = vfp_get_float(dm);
499
500         vdm.sign = (m & 0x80000000) >> 16;
501         vdm.exponent = 1023 + 63 - 1;
502         vdm.significand = vdm.sign ? -m : m;
503
504         return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fsito");
505 }
506
507 static u32 vfp_double_ftoui(int sd, int unused, int dm, u32 fpscr)
508 {
509         struct vfp_double vdm;
510         u32 d, exceptions = 0;
511         int rmode = fpscr & FPSCR_RMODE_MASK;
512         int tm;
513
514         vfp_double_unpack(&vdm, vfp_get_double(dm));
515
516         /*
517          * Do we have a denormalised number?
518          */
519         tm = vfp_double_type(&vdm);
520         if (tm & VFP_DENORMAL)
521                 exceptions |= FPSCR_IDC;
522
523         if (tm & VFP_NAN)
524                 vdm.sign = 0;
525
526         if (vdm.exponent >= 1023 + 32) {
527                 d = vdm.sign ? 0 : 0xffffffff;
528                 exceptions = FPSCR_IOC;
529         } else if (vdm.exponent >= 1023 - 1) {
530                 int shift = 1023 + 63 - vdm.exponent;
531                 u64 rem, incr = 0;
532
533                 /*
534                  * 2^0 <= m < 2^32-2^8
535                  */
536                 d = (vdm.significand << 1) >> shift;
537                 rem = vdm.significand << (65 - shift);
538
539                 if (rmode == FPSCR_ROUND_NEAREST) {
540                         incr = 0x8000000000000000ULL;
541                         if ((d & 1) == 0)
542                                 incr -= 1;
543                 } else if (rmode == FPSCR_ROUND_TOZERO) {
544                         incr = 0;
545                 } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) {
546                         incr = ~0ULL;
547                 }
548
549                 if ((rem + incr) < rem) {
550                         if (d < 0xffffffff)
551                                 d += 1;
552                         else
553                                 exceptions |= FPSCR_IOC;
554                 }
555
556                 if (d && vdm.sign) {
557                         d = 0;
558                         exceptions |= FPSCR_IOC;
559                 } else if (rem)
560                         exceptions |= FPSCR_IXC;
561         } else {
562                 d = 0;
563                 if (vdm.exponent | vdm.significand) {
564                         exceptions |= FPSCR_IXC;
565                         if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0)
566                                 d = 1;
567                         else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) {
568                                 d = 0;
569                                 exceptions |= FPSCR_IOC;
570                         }
571                 }
572         }
573
574         pr_debug("VFP: ftoui: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions);
575
576         vfp_put_float(sd, d);
577
578         return exceptions;
579 }
580
581 static u32 vfp_double_ftouiz(int sd, int unused, int dm, u32 fpscr)
582 {
583         return vfp_double_ftoui(sd, unused, dm, FPSCR_ROUND_TOZERO);
584 }
585
586 static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr)
587 {
588         struct vfp_double vdm;
589         u32 d, exceptions = 0;
590         int rmode = fpscr & FPSCR_RMODE_MASK;
591
592         vfp_double_unpack(&vdm, vfp_get_double(dm));
593         vfp_double_dump("VDM", &vdm);
594
595         /*
596          * Do we have denormalised number?
597          */
598         if (vfp_double_type(&vdm) & VFP_DENORMAL)
599                 exceptions |= FPSCR_IDC;
600
601         if (vdm.exponent >= 1023 + 32) {
602                 d = 0x7fffffff;
603                 if (vdm.sign)
604                         d = ~d;
605                 exceptions |= FPSCR_IOC;
606         } else if (vdm.exponent >= 1023 - 1) {
607                 int shift = 1023 + 63 - vdm.exponent;   /* 58 */
608                 u64 rem, incr = 0;
609
610                 d = (vdm.significand << 1) >> shift;
611                 rem = vdm.significand << (65 - shift);
612
613                 if (rmode == FPSCR_ROUND_NEAREST) {
614                         incr = 0x8000000000000000ULL;
615                         if ((d & 1) == 0)
616                                 incr -= 1;
617                 } else if (rmode == FPSCR_ROUND_TOZERO) {
618                         incr = 0;
619                 } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) {
620                         incr = ~0ULL;
621                 }
622
623                 if ((rem + incr) < rem && d < 0xffffffff)
624                         d += 1;
625                 if (d > 0x7fffffff + (vdm.sign != 0)) {
626                         d = 0x7fffffff + (vdm.sign != 0);
627                         exceptions |= FPSCR_IOC;
628                 } else if (rem)
629                         exceptions |= FPSCR_IXC;
630
631                 if (vdm.sign)
632                         d = -d;
633         } else {
634                 d = 0;
635                 if (vdm.exponent | vdm.significand) {
636                         exceptions |= FPSCR_IXC;
637                         if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0)
638                                 d = 1;
639                         else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign)
640                                 d = -1;
641                 }
642         }
643
644         pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions);
645
646         vfp_put_float(sd, (s32)d);
647
648         return exceptions;
649 }
650
651 static u32 vfp_double_ftosiz(int dd, int unused, int dm, u32 fpscr)
652 {
653         return vfp_double_ftosi(dd, unused, dm, FPSCR_ROUND_TOZERO);
654 }
655
656
657 static u32 (* const fop_extfns[32])(int dd, int unused, int dm, u32 fpscr) = {
658         [FEXT_TO_IDX(FEXT_FCPY)]        = vfp_double_fcpy,
659         [FEXT_TO_IDX(FEXT_FABS)]        = vfp_double_fabs,
660         [FEXT_TO_IDX(FEXT_FNEG)]        = vfp_double_fneg,
661         [FEXT_TO_IDX(FEXT_FSQRT)]       = vfp_double_fsqrt,
662         [FEXT_TO_IDX(FEXT_FCMP)]        = vfp_double_fcmp,
663         [FEXT_TO_IDX(FEXT_FCMPE)]       = vfp_double_fcmpe,
664         [FEXT_TO_IDX(FEXT_FCMPZ)]       = vfp_double_fcmpz,
665         [FEXT_TO_IDX(FEXT_FCMPEZ)]      = vfp_double_fcmpez,
666         [FEXT_TO_IDX(FEXT_FCVT)]        = vfp_double_fcvts,
667         [FEXT_TO_IDX(FEXT_FUITO)]       = vfp_double_fuito,
668         [FEXT_TO_IDX(FEXT_FSITO)]       = vfp_double_fsito,
669         [FEXT_TO_IDX(FEXT_FTOUI)]       = vfp_double_ftoui,
670         [FEXT_TO_IDX(FEXT_FTOUIZ)]      = vfp_double_ftouiz,
671         [FEXT_TO_IDX(FEXT_FTOSI)]       = vfp_double_ftosi,
672         [FEXT_TO_IDX(FEXT_FTOSIZ)]      = vfp_double_ftosiz,
673 };
674
675
676
677
678 static u32
679 vfp_double_fadd_nonnumber(struct vfp_double *vdd, struct vfp_double *vdn,
680                           struct vfp_double *vdm, u32 fpscr)
681 {
682         struct vfp_double *vdp;
683         u32 exceptions = 0;
684         int tn, tm;
685
686         tn = vfp_double_type(vdn);
687         tm = vfp_double_type(vdm);
688
689         if (tn & tm & VFP_INFINITY) {
690                 /*
691                  * Two infinities.  Are they different signs?
692                  */
693                 if (vdn->sign ^ vdm->sign) {
694                         /*
695                          * different signs -> invalid
696                          */
697                         exceptions = FPSCR_IOC;
698                         vdp = &vfp_double_default_qnan;
699                 } else {
700                         /*
701                          * same signs -> valid
702                          */
703                         vdp = vdn;
704                 }
705         } else if (tn & VFP_INFINITY && tm & VFP_NUMBER) {
706                 /*
707                  * One infinity and one number -> infinity
708                  */
709                 vdp = vdn;
710         } else {
711                 /*
712                  * 'n' is a NaN of some type
713                  */
714                 return vfp_propagate_nan(vdd, vdn, vdm, fpscr);
715         }
716         *vdd = *vdp;
717         return exceptions;
718 }
719
720 static u32
721 vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn,
722                struct vfp_double *vdm, u32 fpscr)
723 {
724         u32 exp_diff;
725         u64 m_sig;
726
727         if (vdn->significand & (1ULL << 63) ||
728             vdm->significand & (1ULL << 63)) {
729                 pr_info("VFP: bad FP values in %s\n", __func__);
730                 vfp_double_dump("VDN", vdn);
731                 vfp_double_dump("VDM", vdm);
732         }
733
734         /*
735          * Ensure that 'n' is the largest magnitude number.  Note that
736          * if 'n' and 'm' have equal exponents, we do not swap them.
737          * This ensures that NaN propagation works correctly.
738          */
739         if (vdn->exponent < vdm->exponent) {
740                 struct vfp_double *t = vdn;
741                 vdn = vdm;
742                 vdm = t;
743         }
744
745         /*
746          * Is 'n' an infinity or a NaN?  Note that 'm' may be a number,
747          * infinity or a NaN here.
748          */
749         if (vdn->exponent == 2047)
750                 return vfp_double_fadd_nonnumber(vdd, vdn, vdm, fpscr);
751
752         /*
753          * We have two proper numbers, where 'vdn' is the larger magnitude.
754          *
755          * Copy 'n' to 'd' before doing the arithmetic.
756          */
757         *vdd = *vdn;
758
759         /*
760          * Align 'm' with the result.
761          */
762         exp_diff = vdn->exponent - vdm->exponent;
763         m_sig = vfp_shiftright64jamming(vdm->significand, exp_diff);
764
765         /*
766          * If the signs are different, we are really subtracting.
767          */
768         if (vdn->sign ^ vdm->sign) {
769                 m_sig = vdn->significand - m_sig;
770                 if ((s64)m_sig < 0) {
771                         vdd->sign = vfp_sign_negate(vdd->sign);
772                         m_sig = -m_sig;
773                 }
774         } else {
775                 m_sig += vdn->significand;
776         }
777         vdd->significand = m_sig;
778
779         return 0;
780 }
781
782 static u32
783 vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn,
784                     struct vfp_double *vdm, u32 fpscr)
785 {
786         vfp_double_dump("VDN", vdn);
787         vfp_double_dump("VDM", vdm);
788
789         /*
790          * Ensure that 'n' is the largest magnitude number.  Note that
791          * if 'n' and 'm' have equal exponents, we do not swap them.
792          * This ensures that NaN propagation works correctly.
793          */
794         if (vdn->exponent < vdm->exponent) {
795                 struct vfp_double *t = vdn;
796                 vdn = vdm;
797                 vdm = t;
798                 pr_debug("VFP: swapping M <-> N\n");
799         }
800
801         vdd->sign = vdn->sign ^ vdm->sign;
802
803         /*
804          * If 'n' is an infinity or NaN, handle it.  'm' may be anything.
805          */
806         if (vdn->exponent == 2047) {
807                 if (vdn->significand || (vdm->exponent == 2047 && vdm->significand))
808                         return vfp_propagate_nan(vdd, vdn, vdm, fpscr);
809                 if ((vdm->exponent | vdm->significand) == 0) {
810                         *vdd = vfp_double_default_qnan;
811                         return FPSCR_IOC;
812                 }
813                 vdd->exponent = vdn->exponent;
814                 vdd->significand = 0;
815                 return 0;
816         }
817
818         /*
819          * If 'm' is zero, the result is always zero.  In this case,
820          * 'n' may be zero or a number, but it doesn't matter which.
821          */
822         if ((vdm->exponent | vdm->significand) == 0) {
823                 vdd->exponent = 0;
824                 vdd->significand = 0;
825                 return 0;
826         }
827
828         /*
829          * We add 2 to the destination exponent for the same reason
830          * as the addition case - though this time we have +1 from
831          * each input operand.
832          */
833         vdd->exponent = vdn->exponent + vdm->exponent - 1023 + 2;
834         vdd->significand = vfp_hi64multiply64(vdn->significand, vdm->significand);
835
836         vfp_double_dump("VDD", vdd);
837         return 0;
838 }
839
840 #define NEG_MULTIPLY    (1 << 0)
841 #define NEG_SUBTRACT    (1 << 1)
842
843 static u32
844 vfp_double_multiply_accumulate(int dd, int dn, int dm, u32 fpscr, u32 negate, char *func)
845 {
846         struct vfp_double vdd, vdp, vdn, vdm;
847         u32 exceptions;
848
849         vfp_double_unpack(&vdn, vfp_get_double(dn));
850         if (vdn.exponent == 0 && vdn.significand)
851                 vfp_double_normalise_denormal(&vdn);
852
853         vfp_double_unpack(&vdm, vfp_get_double(dm));
854         if (vdm.exponent == 0 && vdm.significand)
855                 vfp_double_normalise_denormal(&vdm);
856
857         exceptions = vfp_double_multiply(&vdp, &vdn, &vdm, fpscr);
858         if (negate & NEG_MULTIPLY)
859                 vdp.sign = vfp_sign_negate(vdp.sign);
860
861         vfp_double_unpack(&vdn, vfp_get_double(dd));
862         if (negate & NEG_SUBTRACT)
863                 vdn.sign = vfp_sign_negate(vdn.sign);
864
865         exceptions |= vfp_double_add(&vdd, &vdn, &vdp, fpscr);
866
867         return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, func);
868 }
869
870 /*
871  * Standard operations
872  */
873
874 /*
875  * sd = sd + (sn * sm)
876  */
877 static u32 vfp_double_fmac(int dd, int dn, int dm, u32 fpscr)
878 {
879         return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, 0, "fmac");
880 }
881
882 /*
883  * sd = sd - (sn * sm)
884  */
885 static u32 vfp_double_fnmac(int dd, int dn, int dm, u32 fpscr)
886 {
887         return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_MULTIPLY, "fnmac");
888 }
889
890 /*
891  * sd = -sd + (sn * sm)
892  */
893 static u32 vfp_double_fmsc(int dd, int dn, int dm, u32 fpscr)
894 {
895         return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT, "fmsc");
896 }
897
898 /*
899  * sd = -sd - (sn * sm)
900  */
901 static u32 vfp_double_fnmsc(int dd, int dn, int dm, u32 fpscr)
902 {
903         return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT | NEG_MULTIPLY, "fnmsc");
904 }
905
906 /*
907  * sd = sn * sm
908  */
909 static u32 vfp_double_fmul(int dd, int dn, int dm, u32 fpscr)
910 {
911         struct vfp_double vdd, vdn, vdm;
912         u32 exceptions;
913
914         vfp_double_unpack(&vdn, vfp_get_double(dn));
915         if (vdn.exponent == 0 && vdn.significand)
916                 vfp_double_normalise_denormal(&vdn);
917
918         vfp_double_unpack(&vdm, vfp_get_double(dm));
919         if (vdm.exponent == 0 && vdm.significand)
920                 vfp_double_normalise_denormal(&vdm);
921
922         exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr);
923         return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fmul");
924 }
925
926 /*
927  * sd = -(sn * sm)
928  */
929 static u32 vfp_double_fnmul(int dd, int dn, int dm, u32 fpscr)
930 {
931         struct vfp_double vdd, vdn, vdm;
932         u32 exceptions;
933
934         vfp_double_unpack(&vdn, vfp_get_double(dn));
935         if (vdn.exponent == 0 && vdn.significand)
936                 vfp_double_normalise_denormal(&vdn);
937
938         vfp_double_unpack(&vdm, vfp_get_double(dm));
939         if (vdm.exponent == 0 && vdm.significand)
940                 vfp_double_normalise_denormal(&vdm);
941
942         exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr);
943         vdd.sign = vfp_sign_negate(vdd.sign);
944
945         return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fnmul");
946 }
947
948 /*
949  * sd = sn + sm
950  */
951 static u32 vfp_double_fadd(int dd, int dn, int dm, u32 fpscr)
952 {
953         struct vfp_double vdd, vdn, vdm;
954         u32 exceptions;
955
956         vfp_double_unpack(&vdn, vfp_get_double(dn));
957         if (vdn.exponent == 0 && vdn.significand)
958                 vfp_double_normalise_denormal(&vdn);
959
960         vfp_double_unpack(&vdm, vfp_get_double(dm));
961         if (vdm.exponent == 0 && vdm.significand)
962                 vfp_double_normalise_denormal(&vdm);
963
964         exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr);
965
966         return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fadd");
967 }
968
969 /*
970  * sd = sn - sm
971  */
972 static u32 vfp_double_fsub(int dd, int dn, int dm, u32 fpscr)
973 {
974         struct vfp_double vdd, vdn, vdm;
975         u32 exceptions;
976
977         vfp_double_unpack(&vdn, vfp_get_double(dn));
978         if (vdn.exponent == 0 && vdn.significand)
979                 vfp_double_normalise_denormal(&vdn);
980
981         vfp_double_unpack(&vdm, vfp_get_double(dm));
982         if (vdm.exponent == 0 && vdm.significand)
983                 vfp_double_normalise_denormal(&vdm);
984
985         /*
986          * Subtraction is like addition, but with a negated operand.
987          */
988         vdm.sign = vfp_sign_negate(vdm.sign);
989
990         exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr);
991
992         return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fsub");
993 }
994
995 /*
996  * sd = sn / sm
997  */
998 static u32 vfp_double_fdiv(int dd, int dn, int dm, u32 fpscr)
999 {
1000         struct vfp_double vdd, vdn, vdm;
1001         u32 exceptions = 0;
1002         int tm, tn;
1003
1004         vfp_double_unpack(&vdn, vfp_get_double(dn));
1005         vfp_double_unpack(&vdm, vfp_get_double(dm));
1006
1007         vdd.sign = vdn.sign ^ vdm.sign;
1008
1009         tn = vfp_double_type(&vdn);
1010         tm = vfp_double_type(&vdm);
1011
1012         /*
1013          * Is n a NAN?
1014          */
1015         if (tn & VFP_NAN)
1016                 goto vdn_nan;
1017
1018         /*
1019          * Is m a NAN?
1020          */
1021         if (tm & VFP_NAN)
1022                 goto vdm_nan;
1023
1024         /*
1025          * If n and m are infinity, the result is invalid
1026          * If n and m are zero, the result is invalid
1027          */
1028         if (tm & tn & (VFP_INFINITY|VFP_ZERO))
1029                 goto invalid;
1030
1031         /*
1032          * If n is infinity, the result is infinity
1033          */
1034         if (tn & VFP_INFINITY)
1035                 goto infinity;
1036
1037         /*
1038          * If m is zero, raise div0 exceptions
1039          */
1040         if (tm & VFP_ZERO)
1041                 goto divzero;
1042
1043         /*
1044          * If m is infinity, or n is zero, the result is zero
1045          */
1046         if (tm & VFP_INFINITY || tn & VFP_ZERO)
1047                 goto zero;
1048
1049         if (tn & VFP_DENORMAL)
1050                 vfp_double_normalise_denormal(&vdn);
1051         if (tm & VFP_DENORMAL)
1052                 vfp_double_normalise_denormal(&vdm);
1053
1054         /*
1055          * Ok, we have two numbers, we can perform division.
1056          */
1057         vdd.exponent = vdn.exponent - vdm.exponent + 1023 - 1;
1058         vdm.significand <<= 1;
1059         if (vdm.significand <= (2 * vdn.significand)) {
1060                 vdn.significand >>= 1;
1061                 vdd.exponent++;
1062         }
1063         vdd.significand = vfp_estimate_div128to64(vdn.significand, 0, vdm.significand);
1064         if ((vdd.significand & 0x1ff) <= 2) {
1065                 u64 termh, terml, remh, reml;
1066                 mul64to128(&termh, &terml, vdm.significand, vdd.significand);
1067                 sub128(&remh, &reml, vdn.significand, 0, termh, terml);
1068                 while ((s64)remh < 0) {
1069                         vdd.significand -= 1;
1070                         add128(&remh, &reml, remh, reml, 0, vdm.significand);
1071                 }
1072                 vdd.significand |= (reml != 0);
1073         }
1074         return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fdiv");
1075
1076  vdn_nan:
1077         exceptions = vfp_propagate_nan(&vdd, &vdn, &vdm, fpscr);
1078  pack:
1079         vfp_put_double(dd, vfp_double_pack(&vdd));
1080         return exceptions;
1081
1082  vdm_nan:
1083         exceptions = vfp_propagate_nan(&vdd, &vdm, &vdn, fpscr);
1084         goto pack;
1085
1086  zero:
1087         vdd.exponent = 0;
1088         vdd.significand = 0;
1089         goto pack;
1090
1091  divzero:
1092         exceptions = FPSCR_DZC;
1093  infinity:
1094         vdd.exponent = 2047;
1095         vdd.significand = 0;
1096         goto pack;
1097
1098  invalid:
1099         vfp_put_double(dd, vfp_double_pack(&vfp_double_default_qnan));
1100         return FPSCR_IOC;
1101 }
1102
1103 static u32 (* const fop_fns[16])(int dd, int dn, int dm, u32 fpscr) = {
1104         [FOP_TO_IDX(FOP_FMAC)]  = vfp_double_fmac,
1105         [FOP_TO_IDX(FOP_FNMAC)] = vfp_double_fnmac,
1106         [FOP_TO_IDX(FOP_FMSC)]  = vfp_double_fmsc,
1107         [FOP_TO_IDX(FOP_FNMSC)] = vfp_double_fnmsc,
1108         [FOP_TO_IDX(FOP_FMUL)]  = vfp_double_fmul,
1109         [FOP_TO_IDX(FOP_FNMUL)] = vfp_double_fnmul,
1110         [FOP_TO_IDX(FOP_FADD)]  = vfp_double_fadd,
1111         [FOP_TO_IDX(FOP_FSUB)]  = vfp_double_fsub,
1112         [FOP_TO_IDX(FOP_FDIV)]  = vfp_double_fdiv,
1113 };
1114
1115 #define FREG_BANK(x)    ((x) & 0x0c)
1116 #define FREG_IDX(x)     ((x) & 3)
1117
1118 u32 vfp_double_cpdo(u32 inst, u32 fpscr)
1119 {
1120         u32 op = inst & FOP_MASK;
1121         u32 exceptions = 0;
1122         unsigned int dd = vfp_get_sd(inst);
1123         unsigned int dn = vfp_get_sn(inst);
1124         unsigned int dm = vfp_get_sm(inst);
1125         unsigned int vecitr, veclen, vecstride;
1126         u32 (*fop)(int, int, s32, u32);
1127
1128         veclen = fpscr & FPSCR_LENGTH_MASK;
1129         vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)) * 2;
1130
1131         /*
1132          * If destination bank is zero, vector length is always '1'.
1133          * ARM DDI0100F C5.1.3, C5.3.2.
1134          */
1135         if (FREG_BANK(dd) == 0)
1136                 veclen = 0;
1137
1138         pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride,
1139                  (veclen >> FPSCR_LENGTH_BIT) + 1);
1140
1141         fop = (op == FOP_EXT) ? fop_extfns[dn] : fop_fns[FOP_TO_IDX(op)];
1142         if (!fop)
1143                 goto invalid;
1144
1145         for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) {
1146                 u32 except;
1147
1148                 if (op == FOP_EXT)
1149                         pr_debug("VFP: itr%d (d%u.%u) = op[%u] (d%u.%u)\n",
1150                                  vecitr >> FPSCR_LENGTH_BIT,
1151                                  dd >> 1, dd & 1, dn,
1152                                  dm >> 1, dm & 1);
1153                 else
1154                         pr_debug("VFP: itr%d (d%u.%u) = (d%u.%u) op[%u] (d%u.%u)\n",
1155                                  vecitr >> FPSCR_LENGTH_BIT,
1156                                  dd >> 1, dd & 1,
1157                                  dn >> 1, dn & 1,
1158                                  FOP_TO_IDX(op),
1159                                  dm >> 1, dm & 1);
1160
1161                 except = fop(dd, dn, dm, fpscr);
1162                 pr_debug("VFP: itr%d: exceptions=%08x\n",
1163                          vecitr >> FPSCR_LENGTH_BIT, except);
1164
1165                 exceptions |= except;
1166
1167                 /*
1168                  * This ensures that comparisons only operate on scalars;
1169                  * comparisons always return with one FPSCR status bit set.
1170                  */
1171                 if (except & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V))
1172                         break;
1173
1174                 /*
1175                  * CHECK: It appears to be undefined whether we stop when
1176                  * we encounter an exception.  We continue.
1177                  */
1178
1179                 dd = FREG_BANK(dd) + ((FREG_IDX(dd) + vecstride) & 6);
1180                 dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 6);
1181                 if (FREG_BANK(dm) != 0)
1182                         dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 6);
1183         }
1184         return exceptions;
1185
1186  invalid:
1187         return ~0;
1188 }