1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 * vim: set ts=8 sts=4 et sw=4 tw=99:
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 /*
8 * JS math package.
9 */
10
11 #include "jsmath.h"
12
13 #include "mozilla/FloatingPoint.h"
14 #include "mozilla/MathAlgorithms.h"
15 #include "mozilla/MemoryReporting.h"
16
17 #include <algorithm> // for std::max
18 #include <fcntl.h>
19
20 #ifdef XP_UNIX
21 # include <unistd.h>
22 #endif
23
24 #ifdef XP_WIN
25 # include "jswin.h"
26 #endif
27
28 #include "jsapi.h"
29 #include "jsatom.h"
30 #include "jscntxt.h"
31 #include "jscompartment.h"
32 #include "jslibmath.h"
33 #include "jstypes.h"
34
35 #include "jit/InlinableNatives.h"
36 #include "js/Class.h"
37 #include "vm/Time.h"
38
39 #include "jsobjinlines.h"
40
41 #if defined(XP_WIN)
42 // #define needed to link in RtlGenRandom(), a.k.a. SystemFunction036. See the
43 // "Community Additions" comment on MSDN here:
44 // https://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
45 # define SystemFunction036 NTAPI SystemFunction036
46 # include <NTSecAPI.h>
47 # undef SystemFunction036
48 #endif
49
50 #if defined(ANDROID) || defined(XP_DARWIN) || defined(__DragonFly__) || \
51 defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
52 # include <stdlib.h>
53 # define HAVE_ARC4RANDOM
54 #endif
55
56 using namespace js;
57
58 using mozilla::Abs;
59 using mozilla::NumberEqualsInt32;
60 using mozilla::NumberIsInt32;
61 using mozilla::ExponentComponent;
62 using mozilla::FloatingPoint;
63 using mozilla::IsFinite;
64 using mozilla::IsInfinite;
65 using mozilla::IsNaN;
66 using mozilla::IsNegative;
67 using mozilla::IsNegativeZero;
68 using mozilla::PositiveInfinity;
69 using mozilla::NegativeInfinity;
70 using JS::ToNumber;
71 using JS::GenericNaN;
72
73 static const JSConstDoubleSpec math_constants[] = {
74 {"E" , M_E },
75 {"LOG2E" , M_LOG2E },
76 {"LOG10E" , M_LOG10E },
77 {"LN2" , M_LN2 },
78 {"LN10" , M_LN10 },
79 {"PI" , M_PI },
80 {"SQRT2" , M_SQRT2 },
81 {"SQRT1_2", M_SQRT1_2 },
82 {0,0}
83 };
84
MathCache()85 MathCache::MathCache() {
86 memset(table, 0, sizeof(table));
87
88 /* See comments in lookup(). */
89 MOZ_ASSERT(IsNegativeZero(-0.0));
90 MOZ_ASSERT(!IsNegativeZero(+0.0));
91 MOZ_ASSERT(hash(-0.0, MathCache::Sin) != hash(+0.0, MathCache::Sin));
92 }
93
94 size_t
sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)95 MathCache::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
96 {
97 return mallocSizeOf(this);
98 }
99
100 const Class js::MathClass = {
101 js_Math_str,
102 JSCLASS_HAS_CACHED_PROTO(JSProto_Math)
103 };
104
105 bool
math_abs_handle(JSContext * cx,js::HandleValue v,js::MutableHandleValue r)106 js::math_abs_handle(JSContext* cx, js::HandleValue v, js::MutableHandleValue r)
107 {
108 double x;
109 if (!ToNumber(cx, v, &x))
110 return false;
111
112 double z = Abs(x);
113 r.setNumber(z);
114
115 return true;
116 }
117
118 bool
math_abs(JSContext * cx,unsigned argc,Value * vp)119 js::math_abs(JSContext* cx, unsigned argc, Value* vp)
120 {
121 CallArgs args = CallArgsFromVp(argc, vp);
122
123 if (args.length() == 0) {
124 args.rval().setNaN();
125 return true;
126 }
127
128 return math_abs_handle(cx, args[0], args.rval());
129 }
130
131 #if defined(SOLARIS) && defined(__GNUC__)
132 #define ACOS_IF_OUT_OF_RANGE(x) if (x < -1 || 1 < x) return GenericNaN();
133 #else
134 #define ACOS_IF_OUT_OF_RANGE(x)
135 #endif
136
137 double
math_acos_impl(MathCache * cache,double x)138 js::math_acos_impl(MathCache* cache, double x)
139 {
140 ACOS_IF_OUT_OF_RANGE(x);
141 return cache->lookup(acos, x, MathCache::Acos);
142 }
143
144 double
math_acos_uncached(double x)145 js::math_acos_uncached(double x)
146 {
147 ACOS_IF_OUT_OF_RANGE(x);
148 return acos(x);
149 }
150
151 #undef ACOS_IF_OUT_OF_RANGE
152
153 bool
math_acos(JSContext * cx,unsigned argc,Value * vp)154 js::math_acos(JSContext* cx, unsigned argc, Value* vp)
155 {
156 CallArgs args = CallArgsFromVp(argc, vp);
157
158 if (args.length() == 0) {
159 args.rval().setNaN();
160 return true;
161 }
162
163 double x;
164 if (!ToNumber(cx, args[0], &x))
165 return false;
166
167 MathCache* mathCache = cx->runtime()->getMathCache(cx);
168 if (!mathCache)
169 return false;
170
171 double z = math_acos_impl(mathCache, x);
172 args.rval().setDouble(z);
173 return true;
174 }
175
176 #if defined(SOLARIS) && defined(__GNUC__)
177 #define ASIN_IF_OUT_OF_RANGE(x) if (x < -1 || 1 < x) return GenericNaN();
178 #else
179 #define ASIN_IF_OUT_OF_RANGE(x)
180 #endif
181
182 double
math_asin_impl(MathCache * cache,double x)183 js::math_asin_impl(MathCache* cache, double x)
184 {
185 ASIN_IF_OUT_OF_RANGE(x);
186 return cache->lookup(asin, x, MathCache::Asin);
187 }
188
189 double
math_asin_uncached(double x)190 js::math_asin_uncached(double x)
191 {
192 ASIN_IF_OUT_OF_RANGE(x);
193 return asin(x);
194 }
195
196 #undef ASIN_IF_OUT_OF_RANGE
197
198 bool
math_asin(JSContext * cx,unsigned argc,Value * vp)199 js::math_asin(JSContext* cx, unsigned argc, Value* vp)
200 {
201 CallArgs args = CallArgsFromVp(argc, vp);
202
203 if (args.length() == 0) {
204 args.rval().setNaN();
205 return true;
206 }
207
208 double x;
209 if (!ToNumber(cx, args[0], &x))
210 return false;
211
212 MathCache* mathCache = cx->runtime()->getMathCache(cx);
213 if (!mathCache)
214 return false;
215
216 double z = math_asin_impl(mathCache, x);
217 args.rval().setDouble(z);
218 return true;
219 }
220
221 double
math_atan_impl(MathCache * cache,double x)222 js::math_atan_impl(MathCache* cache, double x)
223 {
224 return cache->lookup(atan, x, MathCache::Atan);
225 }
226
227 double
math_atan_uncached(double x)228 js::math_atan_uncached(double x)
229 {
230 return atan(x);
231 }
232
233 bool
math_atan(JSContext * cx,unsigned argc,Value * vp)234 js::math_atan(JSContext* cx, unsigned argc, Value* vp)
235 {
236 CallArgs args = CallArgsFromVp(argc, vp);
237
238 if (args.length() == 0) {
239 args.rval().setNaN();
240 return true;
241 }
242
243 double x;
244 if (!ToNumber(cx, args[0], &x))
245 return false;
246
247 MathCache* mathCache = cx->runtime()->getMathCache(cx);
248 if (!mathCache)
249 return false;
250
251 double z = math_atan_impl(mathCache, x);
252 args.rval().setDouble(z);
253 return true;
254 }
255
256 double
ecmaAtan2(double y,double x)257 js::ecmaAtan2(double y, double x)
258 {
259 #if defined(_MSC_VER)
260 /*
261 * MSVC's atan2 does not yield the result demanded by ECMA when both x
262 * and y are infinite.
263 * - The result is a multiple of pi/4.
264 * - The sign of y determines the sign of the result.
265 * - The sign of x determines the multiplicator, 1 or 3.
266 */
267 if (IsInfinite(y) && IsInfinite(x)) {
268 double z = js_copysign(M_PI / 4, y);
269 if (x < 0)
270 z *= 3;
271 return z;
272 }
273 #endif
274
275 #if defined(SOLARIS) && defined(__GNUC__)
276 if (y == 0) {
277 if (IsNegativeZero(x))
278 return js_copysign(M_PI, y);
279 if (x == 0)
280 return y;
281 }
282 #endif
283 return atan2(y, x);
284 }
285
286 bool
math_atan2_handle(JSContext * cx,HandleValue y,HandleValue x,MutableHandleValue res)287 js::math_atan2_handle(JSContext* cx, HandleValue y, HandleValue x, MutableHandleValue res)
288 {
289 double dy;
290 if (!ToNumber(cx, y, &dy))
291 return false;
292
293 double dx;
294 if (!ToNumber(cx, x, &dx))
295 return false;
296
297 double z = ecmaAtan2(dy, dx);
298 res.setDouble(z);
299 return true;
300 }
301
302 bool
math_atan2(JSContext * cx,unsigned argc,Value * vp)303 js::math_atan2(JSContext* cx, unsigned argc, Value* vp)
304 {
305 CallArgs args = CallArgsFromVp(argc, vp);
306
307 return math_atan2_handle(cx, args.get(0), args.get(1), args.rval());
308 }
309
310 double
math_ceil_impl(double x)311 js::math_ceil_impl(double x)
312 {
313 #ifdef __APPLE__
314 if (x < 0 && x > -1.0)
315 return js_copysign(0, -1);
316 #endif
317 return ceil(x);
318 }
319
320 bool
math_ceil_handle(JSContext * cx,HandleValue v,MutableHandleValue res)321 js::math_ceil_handle(JSContext* cx, HandleValue v, MutableHandleValue res)
322 {
323 double d;
324 if(!ToNumber(cx, v, &d))
325 return false;
326
327 double result = math_ceil_impl(d);
328 res.setNumber(result);
329 return true;
330 }
331
332 bool
math_ceil(JSContext * cx,unsigned argc,Value * vp)333 js::math_ceil(JSContext* cx, unsigned argc, Value* vp)
334 {
335 CallArgs args = CallArgsFromVp(argc, vp);
336
337 if (args.length() == 0) {
338 args.rval().setNaN();
339 return true;
340 }
341
342 return math_ceil_handle(cx, args[0], args.rval());
343 }
344
345 bool
math_clz32(JSContext * cx,unsigned argc,Value * vp)346 js::math_clz32(JSContext* cx, unsigned argc, Value* vp)
347 {
348 CallArgs args = CallArgsFromVp(argc, vp);
349
350 if (args.length() == 0) {
351 args.rval().setInt32(32);
352 return true;
353 }
354
355 uint32_t n;
356 if (!ToUint32(cx, args[0], &n))
357 return false;
358
359 if (n == 0) {
360 args.rval().setInt32(32);
361 return true;
362 }
363
364 args.rval().setInt32(mozilla::CountLeadingZeroes32(n));
365 return true;
366 }
367
368 double
math_cos_impl(MathCache * cache,double x)369 js::math_cos_impl(MathCache* cache, double x)
370 {
371 return cache->lookup(cos, x, MathCache::Cos);
372 }
373
374 double
math_cos_uncached(double x)375 js::math_cos_uncached(double x)
376 {
377 return cos(x);
378 }
379
380 bool
math_cos(JSContext * cx,unsigned argc,Value * vp)381 js::math_cos(JSContext* cx, unsigned argc, Value* vp)
382 {
383 CallArgs args = CallArgsFromVp(argc, vp);
384
385 if (args.length() == 0) {
386 args.rval().setNaN();
387 return true;
388 }
389
390 double x;
391 if (!ToNumber(cx, args[0], &x))
392 return false;
393
394 MathCache* mathCache = cx->runtime()->getMathCache(cx);
395 if (!mathCache)
396 return false;
397
398 double z = math_cos_impl(mathCache, x);
399 args.rval().setDouble(z);
400 return true;
401 }
402
403 #ifdef _WIN32
404 #define EXP_IF_OUT_OF_RANGE(x) \
405 if (!IsNaN(x)) { \
406 if (x == PositiveInfinity<double>()) \
407 return PositiveInfinity<double>(); \
408 if (x == NegativeInfinity<double>()) \
409 return 0.0; \
410 }
411 #else
412 #define EXP_IF_OUT_OF_RANGE(x)
413 #endif
414
415 double
math_exp_impl(MathCache * cache,double x)416 js::math_exp_impl(MathCache* cache, double x)
417 {
418 EXP_IF_OUT_OF_RANGE(x);
419 return cache->lookup(exp, x, MathCache::Exp);
420 }
421
422 double
math_exp_uncached(double x)423 js::math_exp_uncached(double x)
424 {
425 EXP_IF_OUT_OF_RANGE(x);
426 return exp(x);
427 }
428
429 #undef EXP_IF_OUT_OF_RANGE
430
431 bool
math_exp(JSContext * cx,unsigned argc,Value * vp)432 js::math_exp(JSContext* cx, unsigned argc, Value* vp)
433 {
434 CallArgs args = CallArgsFromVp(argc, vp);
435
436 if (args.length() == 0) {
437 args.rval().setNaN();
438 return true;
439 }
440
441 double x;
442 if (!ToNumber(cx, args[0], &x))
443 return false;
444
445 MathCache* mathCache = cx->runtime()->getMathCache(cx);
446 if (!mathCache)
447 return false;
448
449 double z = math_exp_impl(mathCache, x);
450 args.rval().setNumber(z);
451 return true;
452 }
453
454 double
math_floor_impl(double x)455 js::math_floor_impl(double x)
456 {
457 return floor(x);
458 }
459
460 bool
math_floor_handle(JSContext * cx,HandleValue v,MutableHandleValue r)461 js::math_floor_handle(JSContext* cx, HandleValue v, MutableHandleValue r)
462 {
463 double d;
464 if (!ToNumber(cx, v, &d))
465 return false;
466
467 double z = math_floor_impl(d);
468 r.setNumber(z);
469
470 return true;
471 }
472
473 bool
math_floor(JSContext * cx,unsigned argc,Value * vp)474 js::math_floor(JSContext* cx, unsigned argc, Value* vp)
475 {
476 CallArgs args = CallArgsFromVp(argc, vp);
477
478 if (args.length() == 0) {
479 args.rval().setNaN();
480 return true;
481 }
482
483 return math_floor_handle(cx, args[0], args.rval());
484 }
485
486 bool
math_imul_handle(JSContext * cx,HandleValue lhs,HandleValue rhs,MutableHandleValue res)487 js::math_imul_handle(JSContext* cx, HandleValue lhs, HandleValue rhs, MutableHandleValue res)
488 {
489 uint32_t a = 0, b = 0;
490 if (!lhs.isUndefined() && !ToUint32(cx, lhs, &a))
491 return false;
492 if (!rhs.isUndefined() && !ToUint32(cx, rhs, &b))
493 return false;
494
495 uint32_t product = a * b;
496 res.setInt32(product > INT32_MAX
497 ? int32_t(INT32_MIN + (product - INT32_MAX - 1))
498 : int32_t(product));
499 return true;
500 }
501
502 bool
math_imul(JSContext * cx,unsigned argc,Value * vp)503 js::math_imul(JSContext* cx, unsigned argc, Value* vp)
504 {
505 CallArgs args = CallArgsFromVp(argc, vp);
506
507 return math_imul_handle(cx, args.get(0), args.get(1), args.rval());
508 }
509
510 // Implements Math.fround (20.2.2.16) up to step 3
511 bool
RoundFloat32(JSContext * cx,HandleValue v,float * out)512 js::RoundFloat32(JSContext* cx, HandleValue v, float* out)
513 {
514 double d;
515 bool success = ToNumber(cx, v, &d);
516 *out = static_cast<float>(d);
517 return success;
518 }
519
520 bool
RoundFloat32(JSContext * cx,HandleValue arg,MutableHandleValue res)521 js::RoundFloat32(JSContext* cx, HandleValue arg, MutableHandleValue res)
522 {
523 float f;
524 if (!RoundFloat32(cx, arg, &f))
525 return false;
526
527 res.setDouble(static_cast<double>(f));
528 return true;
529 }
530
531 bool
math_fround(JSContext * cx,unsigned argc,Value * vp)532 js::math_fround(JSContext* cx, unsigned argc, Value* vp)
533 {
534 CallArgs args = CallArgsFromVp(argc, vp);
535
536 if (args.length() == 0) {
537 args.rval().setNaN();
538 return true;
539 }
540
541 return RoundFloat32(cx, args[0], args.rval());
542 }
543
544 #if defined(SOLARIS) && defined(__GNUC__)
545 #define LOG_IF_OUT_OF_RANGE(x) if (x < 0) return GenericNaN();
546 #else
547 #define LOG_IF_OUT_OF_RANGE(x)
548 #endif
549
550 double
math_log_impl(MathCache * cache,double x)551 js::math_log_impl(MathCache* cache, double x)
552 {
553 LOG_IF_OUT_OF_RANGE(x);
554 return cache->lookup(math_log_uncached, x, MathCache::Log);
555 }
556
557 double
math_log_uncached(double x)558 js::math_log_uncached(double x)
559 {
560 LOG_IF_OUT_OF_RANGE(x);
561 return log(x);
562 }
563
564 #undef LOG_IF_OUT_OF_RANGE
565
566 bool
math_log_handle(JSContext * cx,HandleValue val,MutableHandleValue res)567 js::math_log_handle(JSContext* cx, HandleValue val, MutableHandleValue res)
568 {
569 double in;
570 if (!ToNumber(cx, val, &in))
571 return false;
572
573 MathCache* mathCache = cx->runtime()->getMathCache(cx);
574 if (!mathCache)
575 return false;
576
577 double out = math_log_impl(mathCache, in);
578 res.setNumber(out);
579 return true;
580 }
581
582 bool
math_log(JSContext * cx,unsigned argc,Value * vp)583 js::math_log(JSContext* cx, unsigned argc, Value* vp)
584 {
585 CallArgs args = CallArgsFromVp(argc, vp);
586
587 if (args.length() == 0) {
588 args.rval().setNaN();
589 return true;
590 }
591
592 return math_log_handle(cx, args[0], args.rval());
593 }
594
595 double
math_max_impl(double x,double y)596 js::math_max_impl(double x, double y)
597 {
598 // Math.max(num, NaN) => NaN, Math.max(-0, +0) => +0
599 if (x > y || IsNaN(x) || (x == y && IsNegative(y)))
600 return x;
601 return y;
602 }
603
604 bool
math_max(JSContext * cx,unsigned argc,Value * vp)605 js::math_max(JSContext* cx, unsigned argc, Value* vp)
606 {
607 CallArgs args = CallArgsFromVp(argc, vp);
608
609 double maxval = NegativeInfinity<double>();
610 for (unsigned i = 0; i < args.length(); i++) {
611 double x;
612 if (!ToNumber(cx, args[i], &x))
613 return false;
614 maxval = math_max_impl(x, maxval);
615 }
616 args.rval().setNumber(maxval);
617 return true;
618 }
619
620 double
math_min_impl(double x,double y)621 js::math_min_impl(double x, double y)
622 {
623 // Math.min(num, NaN) => NaN, Math.min(-0, +0) => -0
624 if (x < y || IsNaN(x) || (x == y && IsNegativeZero(x)))
625 return x;
626 return y;
627 }
628
629 bool
math_min(JSContext * cx,unsigned argc,Value * vp)630 js::math_min(JSContext* cx, unsigned argc, Value* vp)
631 {
632 CallArgs args = CallArgsFromVp(argc, vp);
633
634 double minval = PositiveInfinity<double>();
635 for (unsigned i = 0; i < args.length(); i++) {
636 double x;
637 if (!ToNumber(cx, args[i], &x))
638 return false;
639 minval = math_min_impl(x, minval);
640 }
641 args.rval().setNumber(minval);
642 return true;
643 }
644
645 bool
minmax_impl(JSContext * cx,bool max,HandleValue a,HandleValue b,MutableHandleValue res)646 js::minmax_impl(JSContext* cx, bool max, HandleValue a, HandleValue b, MutableHandleValue res)
647 {
648 double x, y;
649
650 if (!ToNumber(cx, a, &x))
651 return false;
652 if (!ToNumber(cx, b, &y))
653 return false;
654
655 if (max)
656 res.setNumber(math_max_impl(x, y));
657 else
658 res.setNumber(math_min_impl(x, y));
659
660 return true;
661 }
662
663 double
powi(double x,int y)664 js::powi(double x, int y)
665 {
666 unsigned n = (y < 0) ? -y : y;
667 double m = x;
668 double p = 1;
669 while (true) {
670 if ((n & 1) != 0) p *= m;
671 n >>= 1;
672 if (n == 0) {
673 if (y < 0) {
674 // Unfortunately, we have to be careful when p has reached
675 // infinity in the computation, because sometimes the higher
676 // internal precision in the pow() implementation would have
677 // given us a finite p. This happens very rarely.
678
679 double result = 1.0 / p;
680 return (result == 0 && IsInfinite(p))
681 ? pow(x, static_cast<double>(y)) // Avoid pow(double, int).
682 : result;
683 }
684
685 return p;
686 }
687 m *= m;
688 }
689 }
690
691 double
ecmaPow(double x,double y)692 js::ecmaPow(double x, double y)
693 {
694 /*
695 * Use powi if the exponent is an integer-valued double. We don't have to
696 * check for NaN since a comparison with NaN is always false.
697 */
698 int32_t yi;
699 if (NumberEqualsInt32(y, &yi))
700 return powi(x, yi);
701
702 /*
703 * Because C99 and ECMA specify different behavior for pow(),
704 * we need to wrap the libm call to make it ECMA compliant.
705 */
706 if (!IsFinite(y) && (x == 1.0 || x == -1.0))
707 return GenericNaN();
708
709 /* pow(x, +-0) is always 1, even for x = NaN (MSVC gets this wrong). */
710 if (y == 0)
711 return 1;
712
713 /*
714 * Special case for square roots. Note that pow(x, 0.5) != sqrt(x)
715 * when x = -0.0, so we have to guard for this.
716 */
717 if (IsFinite(x) && x != 0.0) {
718 if (y == 0.5)
719 return sqrt(x);
720 if (y == -0.5)
721 return 1.0 / sqrt(x);
722 }
723 return pow(x, y);
724 }
725
726 bool
math_pow_handle(JSContext * cx,HandleValue base,HandleValue power,MutableHandleValue result)727 js::math_pow_handle(JSContext* cx, HandleValue base, HandleValue power, MutableHandleValue result)
728 {
729 double x;
730 if (!ToNumber(cx, base, &x))
731 return false;
732
733 double y;
734 if (!ToNumber(cx, power, &y))
735 return false;
736
737 double z = ecmaPow(x, y);
738 result.setNumber(z);
739 return true;
740 }
741
742 bool
math_pow(JSContext * cx,unsigned argc,Value * vp)743 js::math_pow(JSContext* cx, unsigned argc, Value* vp)
744 {
745 CallArgs args = CallArgsFromVp(argc, vp);
746
747 return math_pow_handle(cx, args.get(0), args.get(1), args.rval());
748 }
749
750 uint64_t
GenerateRandomSeed()751 js::GenerateRandomSeed()
752 {
753 uint64_t seed = 0;
754
755 #if defined(XP_WIN)
756 MOZ_ALWAYS_TRUE(RtlGenRandom(&seed, sizeof(seed)));
757 #elif defined(HAVE_ARC4RANDOM)
758 seed = (static_cast<uint64_t>(arc4random()) << 32) | arc4random();
759 #elif defined(XP_UNIX)
760 int fd = open("/dev/urandom", O_RDONLY);
761 if (fd >= 0) {
762 read(fd, static_cast<void*>(&seed), sizeof(seed));
763 close(fd);
764 }
765 #else
766 # error "Platform needs to implement GenerateRandomSeed()"
767 #endif
768
769 // Also mix in PRMJ_Now() in case we couldn't read random bits from the OS.
770 return seed ^ PRMJ_Now();
771 }
772
773 void
GenerateXorShift128PlusSeed(mozilla::Array<uint64_t,2> & seed)774 js::GenerateXorShift128PlusSeed(mozilla::Array<uint64_t, 2>& seed)
775 {
776 // XorShift128PlusRNG must be initialized with a non-zero seed.
777 do {
778 seed[0] = GenerateRandomSeed();
779 seed[1] = GenerateRandomSeed();
780 } while (seed[0] == 0 && seed[1] == 0);
781 }
782
783 void
ensureRandomNumberGenerator()784 JSCompartment::ensureRandomNumberGenerator()
785 {
786 if (randomNumberGenerator.isNothing()) {
787 mozilla::Array<uint64_t, 2> seed;
788 GenerateXorShift128PlusSeed(seed);
789 randomNumberGenerator.emplace(seed[0], seed[1]);
790 }
791 }
792
793 bool
math_random(JSContext * cx,unsigned argc,Value * vp)794 js::math_random(JSContext* cx, unsigned argc, Value* vp)
795 {
796 CallArgs args = CallArgsFromVp(argc, vp);
797
798 JSCompartment* comp = cx->compartment();
799 comp->ensureRandomNumberGenerator();
800
801 double z = comp->randomNumberGenerator.ref().nextDouble();
802 args.rval().setDouble(z);
803 return true;
804 }
805
806 bool
math_round_handle(JSContext * cx,HandleValue arg,MutableHandleValue res)807 js::math_round_handle(JSContext* cx, HandleValue arg, MutableHandleValue res)
808 {
809 double d;
810 if (!ToNumber(cx, arg, &d))
811 return false;
812
813 d = math_round_impl(d);
814 res.setNumber(d);
815 return true;
816 }
817
818 template<typename T>
819 T
GetBiggestNumberLessThan(T x)820 js::GetBiggestNumberLessThan(T x)
821 {
822 MOZ_ASSERT(!IsNegative(x));
823 MOZ_ASSERT(IsFinite(x));
824 typedef typename mozilla::FloatingPoint<T>::Bits Bits;
825 Bits bits = mozilla::BitwiseCast<Bits>(x);
826 MOZ_ASSERT(bits > 0, "will underflow");
827 return mozilla::BitwiseCast<T>(bits - 1);
828 }
829
830 template double js::GetBiggestNumberLessThan<>(double x);
831 template float js::GetBiggestNumberLessThan<>(float x);
832
833 double
math_round_impl(double x)834 js::math_round_impl(double x)
835 {
836 int32_t ignored;
837 if (NumberIsInt32(x, &ignored))
838 return x;
839
840 /* Some numbers are so big that adding 0.5 would give the wrong number. */
841 if (ExponentComponent(x) >= int_fast16_t(FloatingPoint<double>::kExponentShift))
842 return x;
843
844 double add = (x >= 0) ? GetBiggestNumberLessThan(0.5) : 0.5;
845 return js_copysign(floor(x + add), x);
846 }
847
848 float
math_roundf_impl(float x)849 js::math_roundf_impl(float x)
850 {
851 int32_t ignored;
852 if (NumberIsInt32(x, &ignored))
853 return x;
854
855 /* Some numbers are so big that adding 0.5 would give the wrong number. */
856 if (ExponentComponent(x) >= int_fast16_t(FloatingPoint<float>::kExponentShift))
857 return x;
858
859 float add = (x >= 0) ? GetBiggestNumberLessThan(0.5f) : 0.5f;
860 return js_copysign(floorf(x + add), x);
861 }
862
863 bool /* ES5 15.8.2.15. */
math_round(JSContext * cx,unsigned argc,Value * vp)864 js::math_round(JSContext* cx, unsigned argc, Value* vp)
865 {
866 CallArgs args = CallArgsFromVp(argc, vp);
867
868 if (args.length() == 0) {
869 args.rval().setNaN();
870 return true;
871 }
872
873 return math_round_handle(cx, args[0], args.rval());
874 }
875
876 double
math_sin_impl(MathCache * cache,double x)877 js::math_sin_impl(MathCache* cache, double x)
878 {
879 return cache->lookup(math_sin_uncached, x, MathCache::Sin);
880 }
881
882 double
math_sin_uncached(double x)883 js::math_sin_uncached(double x)
884 {
885 #ifdef _WIN64
886 // Workaround MSVC bug where sin(-0) is +0 instead of -0 on x64 on
887 // CPUs without FMA3 (pre-Haswell). See bug 1076670.
888 if (IsNegativeZero(x))
889 return -0.0;
890 #endif
891 return sin(x);
892 }
893
894 bool
math_sin_handle(JSContext * cx,HandleValue val,MutableHandleValue res)895 js::math_sin_handle(JSContext* cx, HandleValue val, MutableHandleValue res)
896 {
897 double in;
898 if (!ToNumber(cx, val, &in))
899 return false;
900
901 MathCache* mathCache = cx->runtime()->getMathCache(cx);
902 if (!mathCache)
903 return false;
904
905 double out = math_sin_impl(mathCache, in);
906 res.setDouble(out);
907 return true;
908 }
909
910 bool
math_sin(JSContext * cx,unsigned argc,Value * vp)911 js::math_sin(JSContext* cx, unsigned argc, Value* vp)
912 {
913 CallArgs args = CallArgsFromVp(argc, vp);
914
915 if (args.length() == 0) {
916 args.rval().setNaN();
917 return true;
918 }
919
920 return math_sin_handle(cx, args[0], args.rval());
921 }
922
923 void
math_sincos_uncached(double x,double * sin,double * cos)924 js::math_sincos_uncached(double x, double *sin, double *cos)
925 {
926 #if defined(__GLIBC__)
927 sincos(x, sin, cos);
928 #elif defined(HAVE_SINCOS)
929 __sincos(x, sin, cos);
930 #else
931 *sin = js::math_sin_uncached(x);
932 *cos = js::math_cos_uncached(x);
933 #endif
934 }
935
936 void
math_sincos_impl(MathCache * mathCache,double x,double * sin,double * cos)937 js::math_sincos_impl(MathCache* mathCache, double x, double *sin, double *cos)
938 {
939 unsigned indexSin;
940 unsigned indexCos;
941 bool hasSin = mathCache->isCached(x, MathCache::Sin, sin, &indexSin);
942 bool hasCos = mathCache->isCached(x, MathCache::Cos, cos, &indexCos);
943 if (!(hasSin || hasCos)) {
944 js::math_sincos_uncached(x, sin, cos);
945 mathCache->store(MathCache::Sin, x, *sin, indexSin);
946 mathCache->store(MathCache::Cos, x, *cos, indexCos);
947 return;
948 }
949
950 if (!hasSin)
951 *sin = js::math_sin_impl(mathCache, x);
952
953 if (!hasCos)
954 *cos = js::math_cos_impl(mathCache, x);
955 }
956
957 bool
math_sqrt_handle(JSContext * cx,HandleValue number,MutableHandleValue result)958 js::math_sqrt_handle(JSContext* cx, HandleValue number, MutableHandleValue result)
959 {
960 double x;
961 if (!ToNumber(cx, number, &x))
962 return false;
963
964 MathCache* mathCache = cx->runtime()->getMathCache(cx);
965 if (!mathCache)
966 return false;
967
968 double z = mathCache->lookup(sqrt, x, MathCache::Sqrt);
969 result.setDouble(z);
970 return true;
971 }
972
973 bool
math_sqrt(JSContext * cx,unsigned argc,Value * vp)974 js::math_sqrt(JSContext* cx, unsigned argc, Value* vp)
975 {
976 CallArgs args = CallArgsFromVp(argc, vp);
977
978 if (args.length() == 0) {
979 args.rval().setNaN();
980 return true;
981 }
982
983 return math_sqrt_handle(cx, args[0], args.rval());
984 }
985
986 double
math_tan_impl(MathCache * cache,double x)987 js::math_tan_impl(MathCache* cache, double x)
988 {
989 return cache->lookup(tan, x, MathCache::Tan);
990 }
991
992 double
math_tan_uncached(double x)993 js::math_tan_uncached(double x)
994 {
995 return tan(x);
996 }
997
998 bool
math_tan(JSContext * cx,unsigned argc,Value * vp)999 js::math_tan(JSContext* cx, unsigned argc, Value* vp)
1000 {
1001 CallArgs args = CallArgsFromVp(argc, vp);
1002
1003 if (args.length() == 0) {
1004 args.rval().setNaN();
1005 return true;
1006 }
1007
1008 double x;
1009 if (!ToNumber(cx, args[0], &x))
1010 return false;
1011
1012 MathCache* mathCache = cx->runtime()->getMathCache(cx);
1013 if (!mathCache)
1014 return false;
1015
1016 double z = math_tan_impl(mathCache, x);
1017 args.rval().setDouble(z);
1018 return true;
1019 }
1020
1021 typedef double (*UnaryMathFunctionType)(MathCache* cache, double);
1022
1023 template <UnaryMathFunctionType F>
math_function(JSContext * cx,unsigned argc,Value * vp)1024 static bool math_function(JSContext* cx, unsigned argc, Value* vp)
1025 {
1026 CallArgs args = CallArgsFromVp(argc, vp);
1027 if (args.length() == 0) {
1028 args.rval().setNumber(GenericNaN());
1029 return true;
1030 }
1031
1032 double x;
1033 if (!ToNumber(cx, args[0], &x))
1034 return false;
1035
1036 MathCache* mathCache = cx->runtime()->getMathCache(cx);
1037 if (!mathCache)
1038 return false;
1039 double z = F(mathCache, x);
1040 args.rval().setNumber(z);
1041
1042 return true;
1043 }
1044
1045 double
math_log10_impl(MathCache * cache,double x)1046 js::math_log10_impl(MathCache* cache, double x)
1047 {
1048 return cache->lookup(log10, x, MathCache::Log10);
1049 }
1050
1051 double
math_log10_uncached(double x)1052 js::math_log10_uncached(double x)
1053 {
1054 return log10(x);
1055 }
1056
1057 bool
math_log10(JSContext * cx,unsigned argc,Value * vp)1058 js::math_log10(JSContext* cx, unsigned argc, Value* vp)
1059 {
1060 return math_function<math_log10_impl>(cx, argc, vp);
1061 }
1062
1063 #if !HAVE_LOG2
log2(double x)1064 double log2(double x)
1065 {
1066 return log(x) / M_LN2;
1067 }
1068 #endif
1069
1070 double
math_log2_impl(MathCache * cache,double x)1071 js::math_log2_impl(MathCache* cache, double x)
1072 {
1073 return cache->lookup(log2, x, MathCache::Log2);
1074 }
1075
1076 double
math_log2_uncached(double x)1077 js::math_log2_uncached(double x)
1078 {
1079 return log2(x);
1080 }
1081
1082 bool
math_log2(JSContext * cx,unsigned argc,Value * vp)1083 js::math_log2(JSContext* cx, unsigned argc, Value* vp)
1084 {
1085 return math_function<math_log2_impl>(cx, argc, vp);
1086 }
1087
1088 #if !HAVE_LOG1P
log1p(double x)1089 double log1p(double x)
1090 {
1091 if (fabs(x) < 1e-4) {
1092 /*
1093 * Use Taylor approx. log(1 + x) = x - x^2 / 2 + x^3 / 3 - x^4 / 4 with error x^5 / 5
1094 * Since |x| < 10^-4, |x|^5 < 10^-20, relative error less than 10^-16
1095 */
1096 double z = -(x * x * x * x) / 4 + (x * x * x) / 3 - (x * x) / 2 + x;
1097 return z;
1098 } else {
1099 /* For other large enough values of x use direct computation */
1100 return log(1.0 + x);
1101 }
1102 }
1103 #endif
1104
1105 #ifdef __APPLE__
1106 // Ensure that log1p(-0) is -0.
1107 #define LOG1P_IF_OUT_OF_RANGE(x) if (x == 0) return x;
1108 #else
1109 #define LOG1P_IF_OUT_OF_RANGE(x)
1110 #endif
1111
1112 double
math_log1p_impl(MathCache * cache,double x)1113 js::math_log1p_impl(MathCache* cache, double x)
1114 {
1115 LOG1P_IF_OUT_OF_RANGE(x);
1116 return cache->lookup(log1p, x, MathCache::Log1p);
1117 }
1118
1119 double
math_log1p_uncached(double x)1120 js::math_log1p_uncached(double x)
1121 {
1122 LOG1P_IF_OUT_OF_RANGE(x);
1123 return log1p(x);
1124 }
1125
1126 #undef LOG1P_IF_OUT_OF_RANGE
1127
1128 bool
math_log1p(JSContext * cx,unsigned argc,Value * vp)1129 js::math_log1p(JSContext* cx, unsigned argc, Value* vp)
1130 {
1131 return math_function<math_log1p_impl>(cx, argc, vp);
1132 }
1133
1134 #if !HAVE_EXPM1
expm1(double x)1135 double expm1(double x)
1136 {
1137 /* Special handling for -0 */
1138 if (x == 0.0)
1139 return x;
1140
1141 if (fabs(x) < 1e-5) {
1142 /*
1143 * Use Taylor approx. exp(x) - 1 = x + x^2 / 2 + x^3 / 6 with error x^4 / 24
1144 * Since |x| < 10^-5, |x|^4 < 10^-20, relative error less than 10^-15
1145 */
1146 double z = (x * x * x) / 6 + (x * x) / 2 + x;
1147 return z;
1148 } else {
1149 /* For other large enough values of x use direct computation */
1150 return exp(x) - 1.0;
1151 }
1152 }
1153 #endif
1154
1155 double
math_expm1_impl(MathCache * cache,double x)1156 js::math_expm1_impl(MathCache* cache, double x)
1157 {
1158 return cache->lookup(expm1, x, MathCache::Expm1);
1159 }
1160
1161 double
math_expm1_uncached(double x)1162 js::math_expm1_uncached(double x)
1163 {
1164 return expm1(x);
1165 }
1166
1167 bool
math_expm1(JSContext * cx,unsigned argc,Value * vp)1168 js::math_expm1(JSContext* cx, unsigned argc, Value* vp)
1169 {
1170 return math_function<math_expm1_impl>(cx, argc, vp);
1171 }
1172
1173 #if !HAVE_SQRT1PM1
1174 /* This algorithm computes sqrt(1+x)-1 for small x */
sqrt1pm1(double x)1175 double sqrt1pm1(double x)
1176 {
1177 if (fabs(x) > 0.75)
1178 return sqrt(1 + x) - 1;
1179
1180 return expm1(log1p(x) / 2);
1181 }
1182 #endif
1183
1184 double
math_cosh_impl(MathCache * cache,double x)1185 js::math_cosh_impl(MathCache* cache, double x)
1186 {
1187 return cache->lookup(cosh, x, MathCache::Cosh);
1188 }
1189
1190 double
math_cosh_uncached(double x)1191 js::math_cosh_uncached(double x)
1192 {
1193 return cosh(x);
1194 }
1195
1196 bool
math_cosh(JSContext * cx,unsigned argc,Value * vp)1197 js::math_cosh(JSContext* cx, unsigned argc, Value* vp)
1198 {
1199 return math_function<math_cosh_impl>(cx, argc, vp);
1200 }
1201
1202 double
math_sinh_impl(MathCache * cache,double x)1203 js::math_sinh_impl(MathCache* cache, double x)
1204 {
1205 return cache->lookup(sinh, x, MathCache::Sinh);
1206 }
1207
1208 double
math_sinh_uncached(double x)1209 js::math_sinh_uncached(double x)
1210 {
1211 return sinh(x);
1212 }
1213
1214 bool
math_sinh(JSContext * cx,unsigned argc,Value * vp)1215 js::math_sinh(JSContext* cx, unsigned argc, Value* vp)
1216 {
1217 return math_function<math_sinh_impl>(cx, argc, vp);
1218 }
1219
1220 double
math_tanh_impl(MathCache * cache,double x)1221 js::math_tanh_impl(MathCache* cache, double x)
1222 {
1223 return cache->lookup(tanh, x, MathCache::Tanh);
1224 }
1225
1226 double
math_tanh_uncached(double x)1227 js::math_tanh_uncached(double x)
1228 {
1229 return tanh(x);
1230 }
1231
1232 bool
math_tanh(JSContext * cx,unsigned argc,Value * vp)1233 js::math_tanh(JSContext* cx, unsigned argc, Value* vp)
1234 {
1235 return math_function<math_tanh_impl>(cx, argc, vp);
1236 }
1237
1238 #if !HAVE_ACOSH
acosh(double x)1239 double acosh(double x)
1240 {
1241 const double SQUARE_ROOT_EPSILON = sqrt(std::numeric_limits<double>::epsilon());
1242
1243 if ((x - 1) >= SQUARE_ROOT_EPSILON) {
1244 if (x > 1 / SQUARE_ROOT_EPSILON) {
1245 /*
1246 * http://functions.wolfram.com/ElementaryFunctions/ArcCosh/06/01/06/01/0001/
1247 * approximation by laurent series in 1/x at 0+ order from -1 to 0
1248 */
1249 return log(x) + M_LN2;
1250 } else if (x < 1.5) {
1251 // This is just a rearrangement of the standard form below
1252 // devised to minimize loss of precision when x ~ 1:
1253 double y = x - 1;
1254 return log1p(y + sqrt(y * y + 2 * y));
1255 } else {
1256 // http://functions.wolfram.com/ElementaryFunctions/ArcCosh/02/
1257 return log(x + sqrt(x * x - 1));
1258 }
1259 } else {
1260 // see http://functions.wolfram.com/ElementaryFunctions/ArcCosh/06/01/04/01/0001/
1261 double y = x - 1;
1262 // approximation by taylor series in y at 0 up to order 2.
1263 // If x is less than 1, sqrt(2 * y) is NaN and the result is NaN.
1264 return sqrt(2 * y) * (1 - y / 12 + 3 * y * y / 160);
1265 }
1266 }
1267 #endif
1268
1269 double
math_acosh_impl(MathCache * cache,double x)1270 js::math_acosh_impl(MathCache* cache, double x)
1271 {
1272 return cache->lookup(acosh, x, MathCache::Acosh);
1273 }
1274
1275 double
math_acosh_uncached(double x)1276 js::math_acosh_uncached(double x)
1277 {
1278 return acosh(x);
1279 }
1280
1281 bool
math_acosh(JSContext * cx,unsigned argc,Value * vp)1282 js::math_acosh(JSContext* cx, unsigned argc, Value* vp)
1283 {
1284 return math_function<math_acosh_impl>(cx, argc, vp);
1285 }
1286
1287 #if !HAVE_ASINH
1288 // Bug 899712 - gcc incorrectly rewrites -asinh(-x) to asinh(x) when overriding
1289 // asinh.
my_asinh(double x)1290 static double my_asinh(double x)
1291 {
1292 const double SQUARE_ROOT_EPSILON = sqrt(std::numeric_limits<double>::epsilon());
1293 const double FOURTH_ROOT_EPSILON = sqrt(SQUARE_ROOT_EPSILON);
1294
1295 if (x >= FOURTH_ROOT_EPSILON) {
1296 if (x > 1 / SQUARE_ROOT_EPSILON)
1297 // http://functions.wolfram.com/ElementaryFunctions/ArcSinh/06/01/06/01/0001/
1298 // approximation by laurent series in 1/x at 0+ order from -1 to 1
1299 return M_LN2 + log(x) + 1 / (4 * x * x);
1300 else if (x < 0.5)
1301 return log1p(x + sqrt1pm1(x * x));
1302 else
1303 return log(x + sqrt(x * x + 1));
1304 } else if (x <= -FOURTH_ROOT_EPSILON) {
1305 return -my_asinh(-x);
1306 } else {
1307 // http://functions.wolfram.com/ElementaryFunctions/ArcSinh/06/01/03/01/0001/
1308 // approximation by taylor series in x at 0 up to order 2
1309 double result = x;
1310
1311 if (fabs(x) >= SQUARE_ROOT_EPSILON) {
1312 double x3 = x * x * x;
1313 // approximation by taylor series in x at 0 up to order 4
1314 result -= x3 / 6;
1315 }
1316
1317 return result;
1318 }
1319 }
1320 #endif
1321
1322 double
math_asinh_impl(MathCache * cache,double x)1323 js::math_asinh_impl(MathCache* cache, double x)
1324 {
1325 #ifdef HAVE_ASINH
1326 return cache->lookup(asinh, x, MathCache::Asinh);
1327 #else
1328 return cache->lookup(my_asinh, x, MathCache::Asinh);
1329 #endif
1330 }
1331
1332 double
math_asinh_uncached(double x)1333 js::math_asinh_uncached(double x)
1334 {
1335 #ifdef HAVE_ASINH
1336 return asinh(x);
1337 #else
1338 return my_asinh(x);
1339 #endif
1340 }
1341
1342 bool
math_asinh(JSContext * cx,unsigned argc,Value * vp)1343 js::math_asinh(JSContext* cx, unsigned argc, Value* vp)
1344 {
1345 return math_function<math_asinh_impl>(cx, argc, vp);
1346 }
1347
1348 #if !HAVE_ATANH
atanh(double x)1349 double atanh(double x)
1350 {
1351 const double EPSILON = std::numeric_limits<double>::epsilon();
1352 const double SQUARE_ROOT_EPSILON = sqrt(EPSILON);
1353 const double FOURTH_ROOT_EPSILON = sqrt(SQUARE_ROOT_EPSILON);
1354
1355 if (fabs(x) >= FOURTH_ROOT_EPSILON) {
1356 // http://functions.wolfram.com/ElementaryFunctions/ArcTanh/02/
1357 if (fabs(x) < 0.5)
1358 return (log1p(x) - log1p(-x)) / 2;
1359
1360 return log((1 + x) / (1 - x)) / 2;
1361 } else {
1362 // http://functions.wolfram.com/ElementaryFunctions/ArcTanh/06/01/03/01/
1363 // approximation by taylor series in x at 0 up to order 2
1364 double result = x;
1365
1366 if (fabs(x) >= SQUARE_ROOT_EPSILON) {
1367 double x3 = x * x * x;
1368 result += x3 / 3;
1369 }
1370
1371 return result;
1372 }
1373 }
1374 #endif
1375
1376 double
math_atanh_impl(MathCache * cache,double x)1377 js::math_atanh_impl(MathCache* cache, double x)
1378 {
1379 return cache->lookup(atanh, x, MathCache::Atanh);
1380 }
1381
1382 double
math_atanh_uncached(double x)1383 js::math_atanh_uncached(double x)
1384 {
1385 return atanh(x);
1386 }
1387
1388 bool
math_atanh(JSContext * cx,unsigned argc,Value * vp)1389 js::math_atanh(JSContext* cx, unsigned argc, Value* vp)
1390 {
1391 return math_function<math_atanh_impl>(cx, argc, vp);
1392 }
1393
1394 /* Consistency wrapper for platform deviations in hypot() */
1395 double
ecmaHypot(double x,double y)1396 js::ecmaHypot(double x, double y)
1397 {
1398 #ifdef XP_WIN
1399 /*
1400 * Workaround MS hypot bug, where hypot(Infinity, NaN or Math.MIN_VALUE)
1401 * is NaN, not Infinity.
1402 */
1403 if (mozilla::IsInfinite(x) || mozilla::IsInfinite(y)) {
1404 return mozilla::PositiveInfinity<double>();
1405 }
1406 #endif
1407 return hypot(x, y);
1408 }
1409
1410 static inline
1411 void
hypot_step(double & scale,double & sumsq,double x)1412 hypot_step(double& scale, double& sumsq, double x)
1413 {
1414 double xabs = mozilla::Abs(x);
1415 if (scale < xabs) {
1416 sumsq = 1 + sumsq * (scale / xabs) * (scale / xabs);
1417 scale = xabs;
1418 } else if (scale != 0) {
1419 sumsq += (xabs / scale) * (xabs / scale);
1420 }
1421 }
1422
1423 double
hypot4(double x,double y,double z,double w)1424 js::hypot4(double x, double y, double z, double w)
1425 {
1426 /* Check for infinity or NaNs so that we can return immediatelly.
1427 * Does not need to be WIN_XP specific as ecmaHypot
1428 */
1429 if (mozilla::IsInfinite(x) || mozilla::IsInfinite(y) ||
1430 mozilla::IsInfinite(z) || mozilla::IsInfinite(w))
1431 return mozilla::PositiveInfinity<double>();
1432
1433 if (mozilla::IsNaN(x) || mozilla::IsNaN(y) || mozilla::IsNaN(z) ||
1434 mozilla::IsNaN(w))
1435 return GenericNaN();
1436
1437 double scale = 0;
1438 double sumsq = 1;
1439
1440 hypot_step(scale, sumsq, x);
1441 hypot_step(scale, sumsq, y);
1442 hypot_step(scale, sumsq, z);
1443 hypot_step(scale, sumsq, w);
1444
1445 return scale * sqrt(sumsq);
1446 }
1447
1448 double
hypot3(double x,double y,double z)1449 js::hypot3(double x, double y, double z)
1450 {
1451 return hypot4(x, y, z, 0.0);
1452 }
1453
1454 bool
math_hypot(JSContext * cx,unsigned argc,Value * vp)1455 js::math_hypot(JSContext* cx, unsigned argc, Value* vp)
1456 {
1457 CallArgs args = CallArgsFromVp(argc, vp);
1458 return math_hypot_handle(cx, args, args.rval());
1459 }
1460
1461 bool
math_hypot_handle(JSContext * cx,HandleValueArray args,MutableHandleValue res)1462 js::math_hypot_handle(JSContext* cx, HandleValueArray args, MutableHandleValue res)
1463 {
1464 // IonMonkey calls the system hypot function directly if two arguments are
1465 // given. Do that here as well to get the same results.
1466 if (args.length() == 2) {
1467 double x, y;
1468 if (!ToNumber(cx, args[0], &x))
1469 return false;
1470 if (!ToNumber(cx, args[1], &y))
1471 return false;
1472
1473 double result = ecmaHypot(x, y);
1474 res.setNumber(result);
1475 return true;
1476 }
1477
1478 bool isInfinite = false;
1479 bool isNaN = false;
1480
1481 double scale = 0;
1482 double sumsq = 1;
1483
1484 for (unsigned i = 0; i < args.length(); i++) {
1485 double x;
1486 if (!ToNumber(cx, args[i], &x))
1487 return false;
1488
1489 isInfinite |= mozilla::IsInfinite(x);
1490 isNaN |= mozilla::IsNaN(x);
1491 if (isInfinite || isNaN)
1492 continue;
1493
1494 hypot_step(scale, sumsq, x);
1495 }
1496
1497 double result = isInfinite ? PositiveInfinity<double>() :
1498 isNaN ? GenericNaN() :
1499 scale * sqrt(sumsq);
1500 res.setNumber(result);
1501 return true;
1502 }
1503
1504 double
math_trunc_impl(MathCache * cache,double x)1505 js::math_trunc_impl(MathCache* cache, double x)
1506 {
1507 return cache->lookup(trunc, x, MathCache::Trunc);
1508 }
1509
1510 double
math_trunc_uncached(double x)1511 js::math_trunc_uncached(double x)
1512 {
1513 return trunc(x);
1514 }
1515
1516 bool
math_trunc(JSContext * cx,unsigned argc,Value * vp)1517 js::math_trunc(JSContext* cx, unsigned argc, Value* vp)
1518 {
1519 return math_function<math_trunc_impl>(cx, argc, vp);
1520 }
1521
sign(double x)1522 static double sign(double x)
1523 {
1524 if (mozilla::IsNaN(x))
1525 return GenericNaN();
1526
1527 return x == 0 ? x : x < 0 ? -1 : 1;
1528 }
1529
1530 double
math_sign_impl(MathCache * cache,double x)1531 js::math_sign_impl(MathCache* cache, double x)
1532 {
1533 return cache->lookup(sign, x, MathCache::Sign);
1534 }
1535
1536 double
math_sign_uncached(double x)1537 js::math_sign_uncached(double x)
1538 {
1539 return sign(x);
1540 }
1541
1542 bool
math_sign(JSContext * cx,unsigned argc,Value * vp)1543 js::math_sign(JSContext* cx, unsigned argc, Value* vp)
1544 {
1545 return math_function<math_sign_impl>(cx, argc, vp);
1546 }
1547
1548 #if !HAVE_CBRT
cbrt(double x)1549 double cbrt(double x)
1550 {
1551 if (x > 0) {
1552 return pow(x, 1.0 / 3.0);
1553 } else if (x == 0) {
1554 return x;
1555 } else {
1556 return -pow(-x, 1.0 / 3.0);
1557 }
1558 }
1559 #endif
1560
1561 double
math_cbrt_impl(MathCache * cache,double x)1562 js::math_cbrt_impl(MathCache* cache, double x)
1563 {
1564 return cache->lookup(cbrt, x, MathCache::Cbrt);
1565 }
1566
1567 double
math_cbrt_uncached(double x)1568 js::math_cbrt_uncached(double x)
1569 {
1570 return cbrt(x);
1571 }
1572
1573 bool
math_cbrt(JSContext * cx,unsigned argc,Value * vp)1574 js::math_cbrt(JSContext* cx, unsigned argc, Value* vp)
1575 {
1576 return math_function<math_cbrt_impl>(cx, argc, vp);
1577 }
1578
1579 #if JS_HAS_TOSOURCE
1580 static bool
math_toSource(JSContext * cx,unsigned argc,Value * vp)1581 math_toSource(JSContext* cx, unsigned argc, Value* vp)
1582 {
1583 CallArgs args = CallArgsFromVp(argc, vp);
1584 args.rval().setString(cx->names().Math);
1585 return true;
1586 }
1587 #endif
1588
1589 static const JSFunctionSpec math_static_methods[] = {
1590 #if JS_HAS_TOSOURCE
1591 JS_FN(js_toSource_str, math_toSource, 0, 0),
1592 #endif
1593 JS_INLINABLE_FN("abs", math_abs, 1, 0, MathAbs),
1594 JS_INLINABLE_FN("acos", math_acos, 1, 0, MathACos),
1595 JS_INLINABLE_FN("asin", math_asin, 1, 0, MathASin),
1596 JS_INLINABLE_FN("atan", math_atan, 1, 0, MathATan),
1597 JS_INLINABLE_FN("atan2", math_atan2, 2, 0, MathATan2),
1598 JS_INLINABLE_FN("ceil", math_ceil, 1, 0, MathCeil),
1599 JS_INLINABLE_FN("clz32", math_clz32, 1, 0, MathClz32),
1600 JS_INLINABLE_FN("cos", math_cos, 1, 0, MathCos),
1601 JS_INLINABLE_FN("exp", math_exp, 1, 0, MathExp),
1602 JS_INLINABLE_FN("floor", math_floor, 1, 0, MathFloor),
1603 JS_INLINABLE_FN("imul", math_imul, 2, 0, MathImul),
1604 JS_INLINABLE_FN("fround", math_fround, 1, 0, MathFRound),
1605 JS_INLINABLE_FN("log", math_log, 1, 0, MathLog),
1606 JS_INLINABLE_FN("max", math_max, 2, 0, MathMax),
1607 JS_INLINABLE_FN("min", math_min, 2, 0, MathMin),
1608 JS_INLINABLE_FN("pow", math_pow, 2, 0, MathPow),
1609 JS_INLINABLE_FN("random", math_random, 0, 0, MathRandom),
1610 JS_INLINABLE_FN("round", math_round, 1, 0, MathRound),
1611 JS_INLINABLE_FN("sin", math_sin, 1, 0, MathSin),
1612 JS_INLINABLE_FN("sqrt", math_sqrt, 1, 0, MathSqrt),
1613 JS_INLINABLE_FN("tan", math_tan, 1, 0, MathTan),
1614 JS_INLINABLE_FN("log10", math_log10, 1, 0, MathLog10),
1615 JS_INLINABLE_FN("log2", math_log2, 1, 0, MathLog2),
1616 JS_INLINABLE_FN("log1p", math_log1p, 1, 0, MathLog1P),
1617 JS_INLINABLE_FN("expm1", math_expm1, 1, 0, MathExpM1),
1618 JS_INLINABLE_FN("cosh", math_cosh, 1, 0, MathCosH),
1619 JS_INLINABLE_FN("sinh", math_sinh, 1, 0, MathSinH),
1620 JS_INLINABLE_FN("tanh", math_tanh, 1, 0, MathTanH),
1621 JS_INLINABLE_FN("acosh", math_acosh, 1, 0, MathACosH),
1622 JS_INLINABLE_FN("asinh", math_asinh, 1, 0, MathASinH),
1623 JS_INLINABLE_FN("atanh", math_atanh, 1, 0, MathATanH),
1624 JS_INLINABLE_FN("hypot", math_hypot, 2, 0, MathHypot),
1625 JS_INLINABLE_FN("trunc", math_trunc, 1, 0, MathTrunc),
1626 JS_INLINABLE_FN("sign", math_sign, 1, 0, MathSign),
1627 JS_INLINABLE_FN("cbrt", math_cbrt, 1, 0, MathCbrt),
1628 JS_FS_END
1629 };
1630
1631 JSObject*
InitMathClass(JSContext * cx,HandleObject obj)1632 js::InitMathClass(JSContext* cx, HandleObject obj)
1633 {
1634 RootedObject proto(cx, obj->as<GlobalObject>().getOrCreateObjectPrototype(cx));
1635 if (!proto)
1636 return nullptr;
1637 RootedObject Math(cx, NewObjectWithGivenProto(cx, &MathClass, proto, SingletonObject));
1638 if (!Math)
1639 return nullptr;
1640
1641 if (!JS_DefineProperty(cx, obj, js_Math_str, Math, JSPROP_RESOLVING,
1642 JS_STUBGETTER, JS_STUBSETTER))
1643 {
1644 return nullptr;
1645 }
1646 if (!JS_DefineFunctions(cx, Math, math_static_methods))
1647 return nullptr;
1648 if (!JS_DefineConstDoubles(cx, Math, math_constants))
1649 return nullptr;
1650
1651 obj->as<GlobalObject>().setConstructor(JSProto_Math, ObjectValue(*Math));
1652
1653 return Math;
1654 }
1655