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/vfp.h> |
38 | |
39 | #include "vfpinstr.h" |
40 | #include "vfp.h" |
41 | |
42 | static struct vfp_double vfp_double_default_qnan = { |
43 | .exponent = 2047, |
44 | .sign = 0, |
45 | .significand = VFP_DOUBLE_SIGNIFICAND_QNAN, |
46 | }; |
47 | |
48 | static void vfp_double_dump(const char *str, struct vfp_double *d) |
49 | { |
50 | pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n" , |
51 | str, d->sign != 0, d->exponent, d->significand); |
52 | } |
53 | |
54 | static void vfp_double_normalise_denormal(struct vfp_double *vd) |
55 | { |
56 | int bits = 31 - fls(x: vd->significand >> 32); |
57 | if (bits == 31) |
58 | bits = 63 - fls(x: vd->significand); |
59 | |
60 | vfp_double_dump(str: "normalise_denormal: in" , d: vd); |
61 | |
62 | if (bits) { |
63 | vd->exponent -= bits - 1; |
64 | vd->significand <<= bits; |
65 | } |
66 | |
67 | vfp_double_dump(str: "normalise_denormal: out" , d: vd); |
68 | } |
69 | |
70 | u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func) |
71 | { |
72 | u64 significand, incr; |
73 | int exponent, shift, underflow; |
74 | u32 rmode; |
75 | |
76 | vfp_double_dump(str: "pack: in" , d: vd); |
77 | |
78 | /* |
79 | * Infinities and NaNs are a special case. |
80 | */ |
81 | if (vd->exponent == 2047 && (vd->significand == 0 || exceptions)) |
82 | goto pack; |
83 | |
84 | /* |
85 | * Special-case zero. |
86 | */ |
87 | if (vd->significand == 0) { |
88 | vd->exponent = 0; |
89 | goto pack; |
90 | } |
91 | |
92 | exponent = vd->exponent; |
93 | significand = vd->significand; |
94 | |
95 | shift = 32 - fls(x: significand >> 32); |
96 | if (shift == 32) |
97 | shift = 64 - fls(x: significand); |
98 | if (shift) { |
99 | exponent -= shift; |
100 | significand <<= shift; |
101 | } |
102 | |
103 | #ifdef DEBUG |
104 | vd->exponent = exponent; |
105 | vd->significand = significand; |
106 | vfp_double_dump("pack: normalised" , vd); |
107 | #endif |
108 | |
109 | /* |
110 | * Tiny number? |
111 | */ |
112 | underflow = exponent < 0; |
113 | if (underflow) { |
114 | significand = vfp_shiftright64jamming(val: significand, shift: -exponent); |
115 | exponent = 0; |
116 | #ifdef DEBUG |
117 | vd->exponent = exponent; |
118 | vd->significand = significand; |
119 | vfp_double_dump("pack: tiny number" , vd); |
120 | #endif |
121 | if (!(significand & ((1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1))) |
122 | underflow = 0; |
123 | } |
124 | |
125 | /* |
126 | * Select rounding increment. |
127 | */ |
128 | incr = 0; |
129 | rmode = fpscr & FPSCR_RMODE_MASK; |
130 | |
131 | if (rmode == FPSCR_ROUND_NEAREST) { |
132 | incr = 1ULL << VFP_DOUBLE_LOW_BITS; |
133 | if ((significand & (1ULL << (VFP_DOUBLE_LOW_BITS + 1))) == 0) |
134 | incr -= 1; |
135 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
136 | incr = 0; |
137 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vd->sign != 0)) |
138 | incr = (1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1; |
139 | |
140 | pr_debug("VFP: rounding increment = 0x%08llx\n" , incr); |
141 | |
142 | /* |
143 | * Is our rounding going to overflow? |
144 | */ |
145 | if ((significand + incr) < significand) { |
146 | exponent += 1; |
147 | significand = (significand >> 1) | (significand & 1); |
148 | incr >>= 1; |
149 | #ifdef DEBUG |
150 | vd->exponent = exponent; |
151 | vd->significand = significand; |
152 | vfp_double_dump("pack: overflow" , vd); |
153 | #endif |
154 | } |
155 | |
156 | /* |
157 | * If any of the low bits (which will be shifted out of the |
158 | * number) are non-zero, the result is inexact. |
159 | */ |
160 | if (significand & ((1 << (VFP_DOUBLE_LOW_BITS + 1)) - 1)) |
161 | exceptions |= FPSCR_IXC; |
162 | |
163 | /* |
164 | * Do our rounding. |
165 | */ |
166 | significand += incr; |
167 | |
168 | /* |
169 | * Infinity? |
170 | */ |
171 | if (exponent >= 2046) { |
172 | exceptions |= FPSCR_OFC | FPSCR_IXC; |
173 | if (incr == 0) { |
174 | vd->exponent = 2045; |
175 | vd->significand = 0x7fffffffffffffffULL; |
176 | } else { |
177 | vd->exponent = 2047; /* infinity */ |
178 | vd->significand = 0; |
179 | } |
180 | } else { |
181 | if (significand >> (VFP_DOUBLE_LOW_BITS + 1) == 0) |
182 | exponent = 0; |
183 | if (exponent || significand > 0x8000000000000000ULL) |
184 | underflow = 0; |
185 | if (underflow) |
186 | exceptions |= FPSCR_UFC; |
187 | vd->exponent = exponent; |
188 | vd->significand = significand >> 1; |
189 | } |
190 | |
191 | pack: |
192 | vfp_double_dump(str: "pack: final" , d: vd); |
193 | { |
194 | s64 d = vfp_double_pack(s: vd); |
195 | pr_debug("VFP: %s: d(d%d)=%016llx exceptions=%08x\n" , func, |
196 | dd, d, exceptions); |
197 | vfp_put_double(val: d, reg: dd); |
198 | } |
199 | return exceptions; |
200 | } |
201 | |
202 | /* |
203 | * Propagate the NaN, setting exceptions if it is signalling. |
204 | * 'n' is always a NaN. 'm' may be a number, NaN or infinity. |
205 | */ |
206 | static u32 |
207 | vfp_propagate_nan(struct vfp_double *vdd, struct vfp_double *vdn, |
208 | struct vfp_double *vdm, u32 fpscr) |
209 | { |
210 | struct vfp_double *nan; |
211 | int tn, tm = 0; |
212 | |
213 | tn = vfp_double_type(s: vdn); |
214 | |
215 | if (vdm) |
216 | tm = vfp_double_type(s: vdm); |
217 | |
218 | if (fpscr & FPSCR_DEFAULT_NAN) |
219 | /* |
220 | * Default NaN mode - always returns a quiet NaN |
221 | */ |
222 | nan = &vfp_double_default_qnan; |
223 | else { |
224 | /* |
225 | * Contemporary mode - select the first signalling |
226 | * NAN, or if neither are signalling, the first |
227 | * quiet NAN. |
228 | */ |
229 | if (tn == VFP_SNAN || (tm != VFP_SNAN && tn == VFP_QNAN)) |
230 | nan = vdn; |
231 | else |
232 | nan = vdm; |
233 | /* |
234 | * Make the NaN quiet. |
235 | */ |
236 | nan->significand |= VFP_DOUBLE_SIGNIFICAND_QNAN; |
237 | } |
238 | |
239 | *vdd = *nan; |
240 | |
241 | /* |
242 | * If one was a signalling NAN, raise invalid operation. |
243 | */ |
244 | return tn == VFP_SNAN || tm == VFP_SNAN ? FPSCR_IOC : VFP_NAN_FLAG; |
245 | } |
246 | |
247 | /* |
248 | * Extended operations |
249 | */ |
250 | static u32 vfp_double_fabs(int dd, int unused, int dm, u32 fpscr) |
251 | { |
252 | vfp_put_double(vfp_double_packed_abs(vfp_get_double(dm)), reg: dd); |
253 | return 0; |
254 | } |
255 | |
256 | static u32 vfp_double_fcpy(int dd, int unused, int dm, u32 fpscr) |
257 | { |
258 | vfp_put_double(val: vfp_get_double(reg: dm), reg: dd); |
259 | return 0; |
260 | } |
261 | |
262 | static u32 vfp_double_fneg(int dd, int unused, int dm, u32 fpscr) |
263 | { |
264 | vfp_put_double(vfp_double_packed_negate(vfp_get_double(dm)), reg: dd); |
265 | return 0; |
266 | } |
267 | |
268 | static u32 vfp_double_fsqrt(int dd, int unused, int dm, u32 fpscr) |
269 | { |
270 | struct vfp_double vdm, vdd; |
271 | int ret, tm; |
272 | |
273 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
274 | tm = vfp_double_type(s: &vdm); |
275 | if (tm & (VFP_NAN|VFP_INFINITY)) { |
276 | struct vfp_double *vdp = &vdd; |
277 | |
278 | if (tm & VFP_NAN) |
279 | ret = vfp_propagate_nan(vdd: vdp, vdn: &vdm, NULL, fpscr); |
280 | else if (vdm.sign == 0) { |
281 | sqrt_copy: |
282 | vdp = &vdm; |
283 | ret = 0; |
284 | } else { |
285 | sqrt_invalid: |
286 | vdp = &vfp_double_default_qnan; |
287 | ret = FPSCR_IOC; |
288 | } |
289 | vfp_put_double(val: vfp_double_pack(s: vdp), reg: dd); |
290 | return ret; |
291 | } |
292 | |
293 | /* |
294 | * sqrt(+/- 0) == +/- 0 |
295 | */ |
296 | if (tm & VFP_ZERO) |
297 | goto sqrt_copy; |
298 | |
299 | /* |
300 | * Normalise a denormalised number |
301 | */ |
302 | if (tm & VFP_DENORMAL) |
303 | vfp_double_normalise_denormal(vd: &vdm); |
304 | |
305 | /* |
306 | * sqrt(<0) = invalid |
307 | */ |
308 | if (vdm.sign) |
309 | goto sqrt_invalid; |
310 | |
311 | vfp_double_dump(str: "sqrt" , d: &vdm); |
312 | |
313 | /* |
314 | * Estimate the square root. |
315 | */ |
316 | vdd.sign = 0; |
317 | vdd.exponent = ((vdm.exponent - 1023) >> 1) + 1023; |
318 | vdd.significand = (u64)vfp_estimate_sqrt_significand(exponent: vdm.exponent, significand: vdm.significand >> 32) << 31; |
319 | |
320 | vfp_double_dump(str: "sqrt estimate1" , d: &vdd); |
321 | |
322 | vdm.significand >>= 1 + (vdm.exponent & 1); |
323 | vdd.significand += 2 + vfp_estimate_div128to64(nh: vdm.significand, nl: 0, m: vdd.significand); |
324 | |
325 | vfp_double_dump(str: "sqrt estimate2" , d: &vdd); |
326 | |
327 | /* |
328 | * And now adjust. |
329 | */ |
330 | if ((vdd.significand & VFP_DOUBLE_LOW_BITS_MASK) <= 5) { |
331 | if (vdd.significand < 2) { |
332 | vdd.significand = ~0ULL; |
333 | } else { |
334 | u64 termh, terml, remh, reml; |
335 | vdm.significand <<= 2; |
336 | mul64to128(resh: &termh, resl: &terml, n: vdd.significand, m: vdd.significand); |
337 | sub128(resh: &remh, resl: &reml, nh: vdm.significand, nl: 0, mh: termh, ml: terml); |
338 | while ((s64)remh < 0) { |
339 | vdd.significand -= 1; |
340 | shift64left(resh: &termh, resl: &terml, n: vdd.significand); |
341 | terml |= 1; |
342 | add128(resh: &remh, resl: &reml, nh: remh, nl: reml, mh: termh, ml: terml); |
343 | } |
344 | vdd.significand |= (remh | reml) != 0; |
345 | } |
346 | } |
347 | vdd.significand = vfp_shiftright64jamming(val: vdd.significand, shift: 1); |
348 | |
349 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions: 0, func: "fsqrt" ); |
350 | } |
351 | |
352 | /* |
353 | * Equal := ZC |
354 | * Less than := N |
355 | * Greater than := C |
356 | * Unordered := CV |
357 | */ |
358 | static u32 vfp_compare(int dd, int signal_on_qnan, int dm, u32 fpscr) |
359 | { |
360 | s64 d, m; |
361 | u32 ret = 0; |
362 | |
363 | m = vfp_get_double(reg: dm); |
364 | if (vfp_double_packed_exponent(m) == 2047 && vfp_double_packed_mantissa(m)) { |
365 | ret |= FPSCR_C | FPSCR_V; |
366 | if (signal_on_qnan || !(vfp_double_packed_mantissa(m) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
367 | /* |
368 | * Signalling NaN, or signalling on quiet NaN |
369 | */ |
370 | ret |= FPSCR_IOC; |
371 | } |
372 | |
373 | d = vfp_get_double(reg: dd); |
374 | if (vfp_double_packed_exponent(d) == 2047 && vfp_double_packed_mantissa(d)) { |
375 | ret |= FPSCR_C | FPSCR_V; |
376 | if (signal_on_qnan || !(vfp_double_packed_mantissa(d) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
377 | /* |
378 | * Signalling NaN, or signalling on quiet NaN |
379 | */ |
380 | ret |= FPSCR_IOC; |
381 | } |
382 | |
383 | if (ret == 0) { |
384 | if (d == m || vfp_double_packed_abs(d | m) == 0) { |
385 | /* |
386 | * equal |
387 | */ |
388 | ret |= FPSCR_Z | FPSCR_C; |
389 | } else if (vfp_double_packed_sign(d ^ m)) { |
390 | /* |
391 | * different signs |
392 | */ |
393 | if (vfp_double_packed_sign(d)) |
394 | /* |
395 | * d is negative, so d < m |
396 | */ |
397 | ret |= FPSCR_N; |
398 | else |
399 | /* |
400 | * d is positive, so d > m |
401 | */ |
402 | ret |= FPSCR_C; |
403 | } else if ((vfp_double_packed_sign(d) != 0) ^ (d < m)) { |
404 | /* |
405 | * d < m |
406 | */ |
407 | ret |= FPSCR_N; |
408 | } else if ((vfp_double_packed_sign(d) != 0) ^ (d > m)) { |
409 | /* |
410 | * d > m |
411 | */ |
412 | ret |= FPSCR_C; |
413 | } |
414 | } |
415 | |
416 | return ret; |
417 | } |
418 | |
419 | static u32 vfp_double_fcmp(int dd, int unused, int dm, u32 fpscr) |
420 | { |
421 | return vfp_compare(dd, signal_on_qnan: 0, dm, fpscr); |
422 | } |
423 | |
424 | static u32 vfp_double_fcmpe(int dd, int unused, int dm, u32 fpscr) |
425 | { |
426 | return vfp_compare(dd, signal_on_qnan: 1, dm, fpscr); |
427 | } |
428 | |
429 | static u32 vfp_double_fcmpz(int dd, int unused, int dm, u32 fpscr) |
430 | { |
431 | return vfp_compare(dd, signal_on_qnan: 0, VFP_REG_ZERO, fpscr); |
432 | } |
433 | |
434 | static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr) |
435 | { |
436 | return vfp_compare(dd, signal_on_qnan: 1, VFP_REG_ZERO, fpscr); |
437 | } |
438 | |
439 | static u32 vfp_double_fcvts(int sd, int unused, int dm, u32 fpscr) |
440 | { |
441 | struct vfp_double vdm; |
442 | struct vfp_single vsd; |
443 | int tm; |
444 | u32 exceptions = 0; |
445 | |
446 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
447 | |
448 | tm = vfp_double_type(s: &vdm); |
449 | |
450 | /* |
451 | * If we have a signalling NaN, signal invalid operation. |
452 | */ |
453 | if (tm == VFP_SNAN) |
454 | exceptions = FPSCR_IOC; |
455 | |
456 | if (tm & VFP_DENORMAL) |
457 | vfp_double_normalise_denormal(vd: &vdm); |
458 | |
459 | vsd.sign = vdm.sign; |
460 | vsd.significand = vfp_hi64to32jamming(val: vdm.significand); |
461 | |
462 | /* |
463 | * If we have an infinity or a NaN, the exponent must be 255 |
464 | */ |
465 | if (tm & (VFP_INFINITY|VFP_NAN)) { |
466 | vsd.exponent = 255; |
467 | if (tm == VFP_QNAN) |
468 | vsd.significand |= VFP_SINGLE_SIGNIFICAND_QNAN; |
469 | goto pack_nan; |
470 | } else if (tm & VFP_ZERO) |
471 | vsd.exponent = 0; |
472 | else |
473 | vsd.exponent = vdm.exponent - (1023 - 127); |
474 | |
475 | return vfp_single_normaliseround(sd, &vsd, fpscr, exceptions, "fcvts" ); |
476 | |
477 | pack_nan: |
478 | vfp_put_float(val: vfp_single_pack(s: &vsd), reg: sd); |
479 | return exceptions; |
480 | } |
481 | |
482 | static u32 vfp_double_fuito(int dd, int unused, int dm, u32 fpscr) |
483 | { |
484 | struct vfp_double vdm; |
485 | u32 m = vfp_get_float(reg: dm); |
486 | |
487 | vdm.sign = 0; |
488 | vdm.exponent = 1023 + 63 - 1; |
489 | vdm.significand = (u64)m; |
490 | |
491 | return vfp_double_normaliseround(dd, vd: &vdm, fpscr, exceptions: 0, func: "fuito" ); |
492 | } |
493 | |
494 | static u32 vfp_double_fsito(int dd, int unused, int dm, u32 fpscr) |
495 | { |
496 | struct vfp_double vdm; |
497 | u32 m = vfp_get_float(reg: dm); |
498 | |
499 | vdm.sign = (m & 0x80000000) >> 16; |
500 | vdm.exponent = 1023 + 63 - 1; |
501 | vdm.significand = vdm.sign ? -m : m; |
502 | |
503 | return vfp_double_normaliseround(dd, vd: &vdm, fpscr, exceptions: 0, func: "fsito" ); |
504 | } |
505 | |
506 | static u32 vfp_double_ftoui(int sd, int unused, int dm, u32 fpscr) |
507 | { |
508 | struct vfp_double vdm; |
509 | u32 d, exceptions = 0; |
510 | int rmode = fpscr & FPSCR_RMODE_MASK; |
511 | int tm; |
512 | |
513 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
514 | |
515 | /* |
516 | * Do we have a denormalised number? |
517 | */ |
518 | tm = vfp_double_type(s: &vdm); |
519 | if (tm & VFP_DENORMAL) |
520 | exceptions |= FPSCR_IDC; |
521 | |
522 | if (tm & VFP_NAN) |
523 | vdm.sign = 0; |
524 | |
525 | if (vdm.exponent >= 1023 + 32) { |
526 | d = vdm.sign ? 0 : 0xffffffff; |
527 | exceptions = FPSCR_IOC; |
528 | } else if (vdm.exponent >= 1023 - 1) { |
529 | int shift = 1023 + 63 - vdm.exponent; |
530 | u64 rem, incr = 0; |
531 | |
532 | /* |
533 | * 2^0 <= m < 2^32-2^8 |
534 | */ |
535 | d = (vdm.significand << 1) >> shift; |
536 | rem = vdm.significand << (65 - shift); |
537 | |
538 | if (rmode == FPSCR_ROUND_NEAREST) { |
539 | incr = 0x8000000000000000ULL; |
540 | if ((d & 1) == 0) |
541 | incr -= 1; |
542 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
543 | incr = 0; |
544 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
545 | incr = ~0ULL; |
546 | } |
547 | |
548 | if ((rem + incr) < rem) { |
549 | if (d < 0xffffffff) |
550 | d += 1; |
551 | else |
552 | exceptions |= FPSCR_IOC; |
553 | } |
554 | |
555 | if (d && vdm.sign) { |
556 | d = 0; |
557 | exceptions |= FPSCR_IOC; |
558 | } else if (rem) |
559 | exceptions |= FPSCR_IXC; |
560 | } else { |
561 | d = 0; |
562 | if (vdm.exponent | vdm.significand) { |
563 | exceptions |= FPSCR_IXC; |
564 | if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
565 | d = 1; |
566 | else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) { |
567 | d = 0; |
568 | exceptions |= FPSCR_IOC; |
569 | } |
570 | } |
571 | } |
572 | |
573 | pr_debug("VFP: ftoui: d(s%d)=%08x exceptions=%08x\n" , sd, d, exceptions); |
574 | |
575 | vfp_put_float(val: d, reg: sd); |
576 | |
577 | return exceptions; |
578 | } |
579 | |
580 | static u32 vfp_double_ftouiz(int sd, int unused, int dm, u32 fpscr) |
581 | { |
582 | return vfp_double_ftoui(sd, unused, dm, fpscr: FPSCR_ROUND_TOZERO); |
583 | } |
584 | |
585 | static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr) |
586 | { |
587 | struct vfp_double vdm; |
588 | u32 d, exceptions = 0; |
589 | int rmode = fpscr & FPSCR_RMODE_MASK; |
590 | int tm; |
591 | |
592 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
593 | vfp_double_dump(str: "VDM" , d: &vdm); |
594 | |
595 | /* |
596 | * Do we have denormalised number? |
597 | */ |
598 | tm = vfp_double_type(s: &vdm); |
599 | if (tm & VFP_DENORMAL) |
600 | exceptions |= FPSCR_IDC; |
601 | |
602 | if (tm & VFP_NAN) { |
603 | d = 0; |
604 | exceptions |= FPSCR_IOC; |
605 | } else if (vdm.exponent >= 1023 + 32) { |
606 | d = 0x7fffffff; |
607 | if (vdm.sign) |
608 | d = ~d; |
609 | exceptions |= FPSCR_IOC; |
610 | } else if (vdm.exponent >= 1023 - 1) { |
611 | int shift = 1023 + 63 - vdm.exponent; /* 58 */ |
612 | u64 rem, incr = 0; |
613 | |
614 | d = (vdm.significand << 1) >> shift; |
615 | rem = vdm.significand << (65 - shift); |
616 | |
617 | if (rmode == FPSCR_ROUND_NEAREST) { |
618 | incr = 0x8000000000000000ULL; |
619 | if ((d & 1) == 0) |
620 | incr -= 1; |
621 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
622 | incr = 0; |
623 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
624 | incr = ~0ULL; |
625 | } |
626 | |
627 | if ((rem + incr) < rem && d < 0xffffffff) |
628 | d += 1; |
629 | if (d > 0x7fffffff + (vdm.sign != 0)) { |
630 | d = 0x7fffffff + (vdm.sign != 0); |
631 | exceptions |= FPSCR_IOC; |
632 | } else if (rem) |
633 | exceptions |= FPSCR_IXC; |
634 | |
635 | if (vdm.sign) |
636 | d = -d; |
637 | } else { |
638 | d = 0; |
639 | if (vdm.exponent | vdm.significand) { |
640 | exceptions |= FPSCR_IXC; |
641 | if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
642 | d = 1; |
643 | else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) |
644 | d = -1; |
645 | } |
646 | } |
647 | |
648 | pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n" , sd, d, exceptions); |
649 | |
650 | vfp_put_float(val: (s32)d, reg: sd); |
651 | |
652 | return exceptions; |
653 | } |
654 | |
655 | static u32 vfp_double_ftosiz(int dd, int unused, int dm, u32 fpscr) |
656 | { |
657 | return vfp_double_ftosi(sd: dd, unused, dm, fpscr: FPSCR_ROUND_TOZERO); |
658 | } |
659 | |
660 | |
661 | static struct op fops_ext[32] = { |
662 | [FEXT_TO_IDX(FEXT_FCPY)] = { vfp_double_fcpy, 0 }, |
663 | [FEXT_TO_IDX(FEXT_FABS)] = { vfp_double_fabs, 0 }, |
664 | [FEXT_TO_IDX(FEXT_FNEG)] = { vfp_double_fneg, 0 }, |
665 | [FEXT_TO_IDX(FEXT_FSQRT)] = { vfp_double_fsqrt, 0 }, |
666 | [FEXT_TO_IDX(FEXT_FCMP)] = { vfp_double_fcmp, OP_SCALAR }, |
667 | [FEXT_TO_IDX(FEXT_FCMPE)] = { vfp_double_fcmpe, OP_SCALAR }, |
668 | [FEXT_TO_IDX(FEXT_FCMPZ)] = { vfp_double_fcmpz, OP_SCALAR }, |
669 | [FEXT_TO_IDX(FEXT_FCMPEZ)] = { vfp_double_fcmpez, OP_SCALAR }, |
670 | [FEXT_TO_IDX(FEXT_FCVT)] = { vfp_double_fcvts, OP_SCALAR|OP_SD }, |
671 | [FEXT_TO_IDX(FEXT_FUITO)] = { vfp_double_fuito, OP_SCALAR|OP_SM }, |
672 | [FEXT_TO_IDX(FEXT_FSITO)] = { vfp_double_fsito, OP_SCALAR|OP_SM }, |
673 | [FEXT_TO_IDX(FEXT_FTOUI)] = { vfp_double_ftoui, OP_SCALAR|OP_SD }, |
674 | [FEXT_TO_IDX(FEXT_FTOUIZ)] = { vfp_double_ftouiz, OP_SCALAR|OP_SD }, |
675 | [FEXT_TO_IDX(FEXT_FTOSI)] = { vfp_double_ftosi, OP_SCALAR|OP_SD }, |
676 | [FEXT_TO_IDX(FEXT_FTOSIZ)] = { vfp_double_ftosiz, OP_SCALAR|OP_SD }, |
677 | }; |
678 | |
679 | |
680 | |
681 | |
682 | static u32 |
683 | vfp_double_fadd_nonnumber(struct vfp_double *vdd, struct vfp_double *vdn, |
684 | struct vfp_double *vdm, u32 fpscr) |
685 | { |
686 | struct vfp_double *vdp; |
687 | u32 exceptions = 0; |
688 | int tn, tm; |
689 | |
690 | tn = vfp_double_type(s: vdn); |
691 | tm = vfp_double_type(s: vdm); |
692 | |
693 | if (tn & tm & VFP_INFINITY) { |
694 | /* |
695 | * Two infinities. Are they different signs? |
696 | */ |
697 | if (vdn->sign ^ vdm->sign) { |
698 | /* |
699 | * different signs -> invalid |
700 | */ |
701 | exceptions = FPSCR_IOC; |
702 | vdp = &vfp_double_default_qnan; |
703 | } else { |
704 | /* |
705 | * same signs -> valid |
706 | */ |
707 | vdp = vdn; |
708 | } |
709 | } else if (tn & VFP_INFINITY && tm & VFP_NUMBER) { |
710 | /* |
711 | * One infinity and one number -> infinity |
712 | */ |
713 | vdp = vdn; |
714 | } else { |
715 | /* |
716 | * 'n' is a NaN of some type |
717 | */ |
718 | return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
719 | } |
720 | *vdd = *vdp; |
721 | return exceptions; |
722 | } |
723 | |
724 | static u32 |
725 | vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn, |
726 | struct vfp_double *vdm, u32 fpscr) |
727 | { |
728 | u32 exp_diff; |
729 | u64 m_sig; |
730 | |
731 | if (vdn->significand & (1ULL << 63) || |
732 | vdm->significand & (1ULL << 63)) { |
733 | pr_info("VFP: bad FP values in %s\n" , __func__); |
734 | vfp_double_dump(str: "VDN" , d: vdn); |
735 | vfp_double_dump(str: "VDM" , d: vdm); |
736 | } |
737 | |
738 | /* |
739 | * Ensure that 'n' is the largest magnitude number. Note that |
740 | * if 'n' and 'm' have equal exponents, we do not swap them. |
741 | * This ensures that NaN propagation works correctly. |
742 | */ |
743 | if (vdn->exponent < vdm->exponent) { |
744 | struct vfp_double *t = vdn; |
745 | vdn = vdm; |
746 | vdm = t; |
747 | } |
748 | |
749 | /* |
750 | * Is 'n' an infinity or a NaN? Note that 'm' may be a number, |
751 | * infinity or a NaN here. |
752 | */ |
753 | if (vdn->exponent == 2047) |
754 | return vfp_double_fadd_nonnumber(vdd, vdn, vdm, fpscr); |
755 | |
756 | /* |
757 | * We have two proper numbers, where 'vdn' is the larger magnitude. |
758 | * |
759 | * Copy 'n' to 'd' before doing the arithmetic. |
760 | */ |
761 | *vdd = *vdn; |
762 | |
763 | /* |
764 | * Align 'm' with the result. |
765 | */ |
766 | exp_diff = vdn->exponent - vdm->exponent; |
767 | m_sig = vfp_shiftright64jamming(val: vdm->significand, shift: exp_diff); |
768 | |
769 | /* |
770 | * If the signs are different, we are really subtracting. |
771 | */ |
772 | if (vdn->sign ^ vdm->sign) { |
773 | m_sig = vdn->significand - m_sig; |
774 | if ((s64)m_sig < 0) { |
775 | vdd->sign = vfp_sign_negate(vdd->sign); |
776 | m_sig = -m_sig; |
777 | } else if (m_sig == 0) { |
778 | vdd->sign = (fpscr & FPSCR_RMODE_MASK) == |
779 | FPSCR_ROUND_MINUSINF ? 0x8000 : 0; |
780 | } |
781 | } else { |
782 | m_sig += vdn->significand; |
783 | } |
784 | vdd->significand = m_sig; |
785 | |
786 | return 0; |
787 | } |
788 | |
789 | static u32 |
790 | vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn, |
791 | struct vfp_double *vdm, u32 fpscr) |
792 | { |
793 | vfp_double_dump(str: "VDN" , d: vdn); |
794 | vfp_double_dump(str: "VDM" , d: vdm); |
795 | |
796 | /* |
797 | * Ensure that 'n' is the largest magnitude number. Note that |
798 | * if 'n' and 'm' have equal exponents, we do not swap them. |
799 | * This ensures that NaN propagation works correctly. |
800 | */ |
801 | if (vdn->exponent < vdm->exponent) { |
802 | struct vfp_double *t = vdn; |
803 | vdn = vdm; |
804 | vdm = t; |
805 | pr_debug("VFP: swapping M <-> N\n" ); |
806 | } |
807 | |
808 | vdd->sign = vdn->sign ^ vdm->sign; |
809 | |
810 | /* |
811 | * If 'n' is an infinity or NaN, handle it. 'm' may be anything. |
812 | */ |
813 | if (vdn->exponent == 2047) { |
814 | if (vdn->significand || (vdm->exponent == 2047 && vdm->significand)) |
815 | return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
816 | if ((vdm->exponent | vdm->significand) == 0) { |
817 | *vdd = vfp_double_default_qnan; |
818 | return FPSCR_IOC; |
819 | } |
820 | vdd->exponent = vdn->exponent; |
821 | vdd->significand = 0; |
822 | return 0; |
823 | } |
824 | |
825 | /* |
826 | * If 'm' is zero, the result is always zero. In this case, |
827 | * 'n' may be zero or a number, but it doesn't matter which. |
828 | */ |
829 | if ((vdm->exponent | vdm->significand) == 0) { |
830 | vdd->exponent = 0; |
831 | vdd->significand = 0; |
832 | return 0; |
833 | } |
834 | |
835 | /* |
836 | * We add 2 to the destination exponent for the same reason |
837 | * as the addition case - though this time we have +1 from |
838 | * each input operand. |
839 | */ |
840 | vdd->exponent = vdn->exponent + vdm->exponent - 1023 + 2; |
841 | vdd->significand = vfp_hi64multiply64(n: vdn->significand, m: vdm->significand); |
842 | |
843 | vfp_double_dump(str: "VDD" , d: vdd); |
844 | return 0; |
845 | } |
846 | |
847 | #define NEG_MULTIPLY (1 << 0) |
848 | #define NEG_SUBTRACT (1 << 1) |
849 | |
850 | static u32 |
851 | vfp_double_multiply_accumulate(int dd, int dn, int dm, u32 fpscr, u32 negate, char *func) |
852 | { |
853 | struct vfp_double vdd, vdp, vdn, vdm; |
854 | u32 exceptions; |
855 | |
856 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
857 | if (vdn.exponent == 0 && vdn.significand) |
858 | vfp_double_normalise_denormal(vd: &vdn); |
859 | |
860 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
861 | if (vdm.exponent == 0 && vdm.significand) |
862 | vfp_double_normalise_denormal(vd: &vdm); |
863 | |
864 | exceptions = vfp_double_multiply(vdd: &vdp, vdn: &vdn, vdm: &vdm, fpscr); |
865 | if (negate & NEG_MULTIPLY) |
866 | vdp.sign = vfp_sign_negate(vdp.sign); |
867 | |
868 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dd)); |
869 | if (vdn.exponent == 0 && vdn.significand) |
870 | vfp_double_normalise_denormal(vd: &vdn); |
871 | if (negate & NEG_SUBTRACT) |
872 | vdn.sign = vfp_sign_negate(vdn.sign); |
873 | |
874 | exceptions |= vfp_double_add(vdd: &vdd, vdn: &vdn, vdm: &vdp, fpscr); |
875 | |
876 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions, func); |
877 | } |
878 | |
879 | /* |
880 | * Standard operations |
881 | */ |
882 | |
883 | /* |
884 | * sd = sd + (sn * sm) |
885 | */ |
886 | static u32 vfp_double_fmac(int dd, int dn, int dm, u32 fpscr) |
887 | { |
888 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, negate: 0, func: "fmac" ); |
889 | } |
890 | |
891 | /* |
892 | * sd = sd - (sn * sm) |
893 | */ |
894 | static u32 vfp_double_fnmac(int dd, int dn, int dm, u32 fpscr) |
895 | { |
896 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_MULTIPLY, func: "fnmac" ); |
897 | } |
898 | |
899 | /* |
900 | * sd = -sd + (sn * sm) |
901 | */ |
902 | static u32 vfp_double_fmsc(int dd, int dn, int dm, u32 fpscr) |
903 | { |
904 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT, func: "fmsc" ); |
905 | } |
906 | |
907 | /* |
908 | * sd = -sd - (sn * sm) |
909 | */ |
910 | static u32 vfp_double_fnmsc(int dd, int dn, int dm, u32 fpscr) |
911 | { |
912 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT | NEG_MULTIPLY, func: "fnmsc" ); |
913 | } |
914 | |
915 | /* |
916 | * sd = sn * sm |
917 | */ |
918 | static u32 vfp_double_fmul(int dd, int dn, int dm, u32 fpscr) |
919 | { |
920 | struct vfp_double vdd, vdn, vdm; |
921 | u32 exceptions; |
922 | |
923 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
924 | if (vdn.exponent == 0 && vdn.significand) |
925 | vfp_double_normalise_denormal(vd: &vdn); |
926 | |
927 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
928 | if (vdm.exponent == 0 && vdm.significand) |
929 | vfp_double_normalise_denormal(vd: &vdm); |
930 | |
931 | exceptions = vfp_double_multiply(vdd: &vdd, vdn: &vdn, vdm: &vdm, fpscr); |
932 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions, func: "fmul" ); |
933 | } |
934 | |
935 | /* |
936 | * sd = -(sn * sm) |
937 | */ |
938 | static u32 vfp_double_fnmul(int dd, int dn, int dm, u32 fpscr) |
939 | { |
940 | struct vfp_double vdd, vdn, vdm; |
941 | u32 exceptions; |
942 | |
943 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
944 | if (vdn.exponent == 0 && vdn.significand) |
945 | vfp_double_normalise_denormal(vd: &vdn); |
946 | |
947 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
948 | if (vdm.exponent == 0 && vdm.significand) |
949 | vfp_double_normalise_denormal(vd: &vdm); |
950 | |
951 | exceptions = vfp_double_multiply(vdd: &vdd, vdn: &vdn, vdm: &vdm, fpscr); |
952 | vdd.sign = vfp_sign_negate(vdd.sign); |
953 | |
954 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions, func: "fnmul" ); |
955 | } |
956 | |
957 | /* |
958 | * sd = sn + sm |
959 | */ |
960 | static u32 vfp_double_fadd(int dd, int dn, int dm, u32 fpscr) |
961 | { |
962 | struct vfp_double vdd, vdn, vdm; |
963 | u32 exceptions; |
964 | |
965 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
966 | if (vdn.exponent == 0 && vdn.significand) |
967 | vfp_double_normalise_denormal(vd: &vdn); |
968 | |
969 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
970 | if (vdm.exponent == 0 && vdm.significand) |
971 | vfp_double_normalise_denormal(vd: &vdm); |
972 | |
973 | exceptions = vfp_double_add(vdd: &vdd, vdn: &vdn, vdm: &vdm, fpscr); |
974 | |
975 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions, func: "fadd" ); |
976 | } |
977 | |
978 | /* |
979 | * sd = sn - sm |
980 | */ |
981 | static u32 vfp_double_fsub(int dd, int dn, int dm, u32 fpscr) |
982 | { |
983 | struct vfp_double vdd, vdn, vdm; |
984 | u32 exceptions; |
985 | |
986 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
987 | if (vdn.exponent == 0 && vdn.significand) |
988 | vfp_double_normalise_denormal(vd: &vdn); |
989 | |
990 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
991 | if (vdm.exponent == 0 && vdm.significand) |
992 | vfp_double_normalise_denormal(vd: &vdm); |
993 | |
994 | /* |
995 | * Subtraction is like addition, but with a negated operand. |
996 | */ |
997 | vdm.sign = vfp_sign_negate(vdm.sign); |
998 | |
999 | exceptions = vfp_double_add(vdd: &vdd, vdn: &vdn, vdm: &vdm, fpscr); |
1000 | |
1001 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions, func: "fsub" ); |
1002 | } |
1003 | |
1004 | /* |
1005 | * sd = sn / sm |
1006 | */ |
1007 | static u32 vfp_double_fdiv(int dd, int dn, int dm, u32 fpscr) |
1008 | { |
1009 | struct vfp_double vdd, vdn, vdm; |
1010 | u32 exceptions = 0; |
1011 | int tm, tn; |
1012 | |
1013 | vfp_double_unpack(s: &vdn, val: vfp_get_double(reg: dn)); |
1014 | vfp_double_unpack(s: &vdm, val: vfp_get_double(reg: dm)); |
1015 | |
1016 | vdd.sign = vdn.sign ^ vdm.sign; |
1017 | |
1018 | tn = vfp_double_type(s: &vdn); |
1019 | tm = vfp_double_type(s: &vdm); |
1020 | |
1021 | /* |
1022 | * Is n a NAN? |
1023 | */ |
1024 | if (tn & VFP_NAN) |
1025 | goto vdn_nan; |
1026 | |
1027 | /* |
1028 | * Is m a NAN? |
1029 | */ |
1030 | if (tm & VFP_NAN) |
1031 | goto vdm_nan; |
1032 | |
1033 | /* |
1034 | * If n and m are infinity, the result is invalid |
1035 | * If n and m are zero, the result is invalid |
1036 | */ |
1037 | if (tm & tn & (VFP_INFINITY|VFP_ZERO)) |
1038 | goto invalid; |
1039 | |
1040 | /* |
1041 | * If n is infinity, the result is infinity |
1042 | */ |
1043 | if (tn & VFP_INFINITY) |
1044 | goto infinity; |
1045 | |
1046 | /* |
1047 | * If m is zero, raise div0 exceptions |
1048 | */ |
1049 | if (tm & VFP_ZERO) |
1050 | goto divzero; |
1051 | |
1052 | /* |
1053 | * If m is infinity, or n is zero, the result is zero |
1054 | */ |
1055 | if (tm & VFP_INFINITY || tn & VFP_ZERO) |
1056 | goto zero; |
1057 | |
1058 | if (tn & VFP_DENORMAL) |
1059 | vfp_double_normalise_denormal(vd: &vdn); |
1060 | if (tm & VFP_DENORMAL) |
1061 | vfp_double_normalise_denormal(vd: &vdm); |
1062 | |
1063 | /* |
1064 | * Ok, we have two numbers, we can perform division. |
1065 | */ |
1066 | vdd.exponent = vdn.exponent - vdm.exponent + 1023 - 1; |
1067 | vdm.significand <<= 1; |
1068 | if (vdm.significand <= (2 * vdn.significand)) { |
1069 | vdn.significand >>= 1; |
1070 | vdd.exponent++; |
1071 | } |
1072 | vdd.significand = vfp_estimate_div128to64(nh: vdn.significand, nl: 0, m: vdm.significand); |
1073 | if ((vdd.significand & 0x1ff) <= 2) { |
1074 | u64 termh, terml, remh, reml; |
1075 | mul64to128(resh: &termh, resl: &terml, n: vdm.significand, m: vdd.significand); |
1076 | sub128(resh: &remh, resl: &reml, nh: vdn.significand, nl: 0, mh: termh, ml: terml); |
1077 | while ((s64)remh < 0) { |
1078 | vdd.significand -= 1; |
1079 | add128(resh: &remh, resl: &reml, nh: remh, nl: reml, mh: 0, ml: vdm.significand); |
1080 | } |
1081 | vdd.significand |= (reml != 0); |
1082 | } |
1083 | return vfp_double_normaliseround(dd, vd: &vdd, fpscr, exceptions: 0, func: "fdiv" ); |
1084 | |
1085 | vdn_nan: |
1086 | exceptions = vfp_propagate_nan(vdd: &vdd, vdn: &vdn, vdm: &vdm, fpscr); |
1087 | pack: |
1088 | vfp_put_double(val: vfp_double_pack(s: &vdd), reg: dd); |
1089 | return exceptions; |
1090 | |
1091 | vdm_nan: |
1092 | exceptions = vfp_propagate_nan(vdd: &vdd, vdn: &vdm, vdm: &vdn, fpscr); |
1093 | goto pack; |
1094 | |
1095 | zero: |
1096 | vdd.exponent = 0; |
1097 | vdd.significand = 0; |
1098 | goto pack; |
1099 | |
1100 | divzero: |
1101 | exceptions = FPSCR_DZC; |
1102 | infinity: |
1103 | vdd.exponent = 2047; |
1104 | vdd.significand = 0; |
1105 | goto pack; |
1106 | |
1107 | invalid: |
1108 | vfp_put_double(val: vfp_double_pack(s: &vfp_double_default_qnan), reg: dd); |
1109 | return FPSCR_IOC; |
1110 | } |
1111 | |
1112 | static struct op fops[16] = { |
1113 | [FOP_TO_IDX(FOP_FMAC)] = { vfp_double_fmac, 0 }, |
1114 | [FOP_TO_IDX(FOP_FNMAC)] = { vfp_double_fnmac, 0 }, |
1115 | [FOP_TO_IDX(FOP_FMSC)] = { vfp_double_fmsc, 0 }, |
1116 | [FOP_TO_IDX(FOP_FNMSC)] = { vfp_double_fnmsc, 0 }, |
1117 | [FOP_TO_IDX(FOP_FMUL)] = { vfp_double_fmul, 0 }, |
1118 | [FOP_TO_IDX(FOP_FNMUL)] = { vfp_double_fnmul, 0 }, |
1119 | [FOP_TO_IDX(FOP_FADD)] = { vfp_double_fadd, 0 }, |
1120 | [FOP_TO_IDX(FOP_FSUB)] = { vfp_double_fsub, 0 }, |
1121 | [FOP_TO_IDX(FOP_FDIV)] = { vfp_double_fdiv, 0 }, |
1122 | }; |
1123 | |
1124 | #define FREG_BANK(x) ((x) & 0x0c) |
1125 | #define FREG_IDX(x) ((x) & 3) |
1126 | |
1127 | u32 vfp_double_cpdo(u32 inst, u32 fpscr) |
1128 | { |
1129 | u32 op = inst & FOP_MASK; |
1130 | u32 exceptions = 0; |
1131 | unsigned int dest; |
1132 | unsigned int dn = vfp_get_dn(inst); |
1133 | unsigned int dm; |
1134 | unsigned int vecitr, veclen, vecstride; |
1135 | struct op *fop; |
1136 | |
1137 | vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)); |
1138 | |
1139 | fop = (op == FOP_EXT) ? &fops_ext[FEXT_TO_IDX(inst)] : &fops[FOP_TO_IDX(op)]; |
1140 | |
1141 | /* |
1142 | * fcvtds takes an sN register number as destination, not dN. |
1143 | * It also always operates on scalars. |
1144 | */ |
1145 | if (fop->flags & OP_SD) |
1146 | dest = vfp_get_sd(inst); |
1147 | else |
1148 | dest = vfp_get_dd(inst); |
1149 | |
1150 | /* |
1151 | * f[us]ito takes a sN operand, not a dN operand. |
1152 | */ |
1153 | if (fop->flags & OP_SM) |
1154 | dm = vfp_get_sm(inst); |
1155 | else |
1156 | dm = vfp_get_dm(inst); |
1157 | |
1158 | /* |
1159 | * If destination bank is zero, vector length is always '1'. |
1160 | * ARM DDI0100F C5.1.3, C5.3.2. |
1161 | */ |
1162 | if ((fop->flags & OP_SCALAR) || (FREG_BANK(dest) == 0)) |
1163 | veclen = 0; |
1164 | else |
1165 | veclen = fpscr & FPSCR_LENGTH_MASK; |
1166 | |
1167 | pr_debug("VFP: vecstride=%u veclen=%u\n" , vecstride, |
1168 | (veclen >> FPSCR_LENGTH_BIT) + 1); |
1169 | |
1170 | if (!fop->fn) |
1171 | goto invalid; |
1172 | |
1173 | for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) { |
1174 | u32 except; |
1175 | char type; |
1176 | |
1177 | type = fop->flags & OP_SD ? 's' : 'd'; |
1178 | if (op == FOP_EXT) |
1179 | pr_debug("VFP: itr%d (%c%u) = op[%u] (d%u)\n" , |
1180 | vecitr >> FPSCR_LENGTH_BIT, |
1181 | type, dest, dn, dm); |
1182 | else |
1183 | pr_debug("VFP: itr%d (%c%u) = (d%u) op[%u] (d%u)\n" , |
1184 | vecitr >> FPSCR_LENGTH_BIT, |
1185 | type, dest, dn, FOP_TO_IDX(op), dm); |
1186 | |
1187 | except = fop->fn(dest, dn, dm, fpscr); |
1188 | pr_debug("VFP: itr%d: exceptions=%08x\n" , |
1189 | vecitr >> FPSCR_LENGTH_BIT, except); |
1190 | |
1191 | exceptions |= except; |
1192 | |
1193 | /* |
1194 | * CHECK: It appears to be undefined whether we stop when |
1195 | * we encounter an exception. We continue. |
1196 | */ |
1197 | dest = FREG_BANK(dest) + ((FREG_IDX(dest) + vecstride) & 3); |
1198 | dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 3); |
1199 | if (FREG_BANK(dm) != 0) |
1200 | dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 3); |
1201 | } |
1202 | return exceptions; |
1203 | |
1204 | invalid: |
1205 | return ~0; |
1206 | } |
1207 | |