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gecko/js/src/jsmath.cpp
Benjamin Bouvier 5b77ae66ed Bug 878488: Implement asm.js Math constants; r=luke
2014-02-04 16:11:54 +01:00

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* JS math package.
*/
#include "jsmath.h"
#include "mozilla/Constants.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"
#include <algorithm> // for std::max
#include <fcntl.h>
#ifdef XP_UNIX
# include <unistd.h>
#endif
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jscompartment.h"
#include "jslibmath.h"
#include "jstypes.h"
#include "prmjtime.h"
#include "jsobjinlines.h"
using namespace js;
using mozilla::Abs;
using mozilla::DoubleEqualsInt32;
using mozilla::DoubleIsInt32;
using mozilla::ExponentComponent;
using mozilla::IsFinite;
using mozilla::IsInfinite;
using mozilla::IsNaN;
using mozilla::IsNegative;
using mozilla::IsNegativeZero;
using mozilla::PositiveInfinity;
using mozilla::NegativeInfinity;
using mozilla::SpecificNaN;
using JS::ToNumber;
using JS::GenericNaN;
static const JSConstDoubleSpec math_constants[] = {
{M_E, "E", 0, {0,0,0}},
{M_LOG2E, "LOG2E", 0, {0,0,0}},
{M_LOG10E, "LOG10E", 0, {0,0,0}},
{M_LN2, "LN2", 0, {0,0,0}},
{M_LN10, "LN10", 0, {0,0,0}},
{M_PI, "PI", 0, {0,0,0}},
{M_SQRT2, "SQRT2", 0, {0,0,0}},
{M_SQRT1_2, "SQRT1_2", 0, {0,0,0}},
{0,0,0,{0,0,0}}
};
MathCache::MathCache() {
memset(table, 0, sizeof(table));
/* See comments in lookup(). */
JS_ASSERT(IsNegativeZero(-0.0));
JS_ASSERT(!IsNegativeZero(+0.0));
JS_ASSERT(hash(-0.0) != hash(+0.0));
}
size_t
MathCache::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
{
return mallocSizeOf(this);
}
const Class js::MathClass = {
js_Math_str,
JSCLASS_HAS_CACHED_PROTO(JSProto_Math),
JS_PropertyStub, /* addProperty */
JS_DeletePropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub
};
bool
js_math_abs(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
double z = Abs(x);
args.rval().setNumber(z);
return true;
}
#if defined(SOLARIS) && defined(__GNUC__)
#define ACOS_IF_OUT_OF_RANGE(x) if (x < -1 || 1 < x) return GenericNaN();
#else
#define ACOS_IF_OUT_OF_RANGE(x)
#endif
double
js::math_acos_impl(MathCache *cache, double x)
{
ACOS_IF_OUT_OF_RANGE(x);
return cache->lookup(acos, x);
}
double
js::math_acos_uncached(double x)
{
ACOS_IF_OUT_OF_RANGE(x);
return acos(x);
}
#undef ACOS_IF_OUT_OF_RANGE
bool
js::math_acos(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_acos_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
#if defined(SOLARIS) && defined(__GNUC__)
#define ASIN_IF_OUT_OF_RANGE(x) if (x < -1 || 1 < x) return GenericNaN();
#else
#define ASIN_IF_OUT_OF_RANGE(x)
#endif
double
js::math_asin_impl(MathCache *cache, double x)
{
ASIN_IF_OUT_OF_RANGE(x);
return cache->lookup(asin, x);
}
double
js::math_asin_uncached(double x)
{
ASIN_IF_OUT_OF_RANGE(x);
return asin(x);
}
#undef ASIN_IF_OUT_OF_RANGE
bool
js::math_asin(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_asin_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
double
js::math_atan_impl(MathCache *cache, double x)
{
return cache->lookup(atan, x);
}
double
js::math_atan_uncached(double x)
{
return atan(x);
}
bool
js::math_atan(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_atan_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
double
js::ecmaAtan2(double y, double x)
{
#if defined(_MSC_VER)
/*
* MSVC's atan2 does not yield the result demanded by ECMA when both x
* and y are infinite.
* - The result is a multiple of pi/4.
* - The sign of y determines the sign of the result.
* - The sign of x determines the multiplicator, 1 or 3.
*/
if (IsInfinite(y) && IsInfinite(x)) {
double z = js_copysign(M_PI / 4, y);
if (x < 0)
z *= 3;
return z;
}
#endif
#if defined(SOLARIS) && defined(__GNUC__)
if (y == 0) {
if (IsNegativeZero(x))
return js_copysign(M_PI, y);
if (x == 0)
return y;
}
#endif
return atan2(y, x);
}
bool
js::math_atan2(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
double y;
if (!ToNumber(cx, args.get(0), &y))
return false;
double x;
if (!ToNumber(cx, args.get(1), &x))
return false;
double z = ecmaAtan2(y, x);
args.rval().setDouble(z);
return true;
}
double
js::math_ceil_impl(double x)
{
#ifdef __APPLE__
if (x < 0 && x > -1.0)
return js_copysign(0, -1);
#endif
return ceil(x);
}
bool
js::math_ceil(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
double z = math_ceil_impl(x);
args.rval().setNumber(z);
return true;
}
double
js::math_cos_impl(MathCache *cache, double x)
{
return cache->lookup(cos, x);
}
double
js::math_cos_uncached(double x)
{
return cos(x);
}
bool
js::math_cos(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_cos_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
#ifdef _WIN32
#define EXP_IF_OUT_OF_RANGE(x) \
if (!IsNaN(x)) { \
if (x == PositiveInfinity()) \
return PositiveInfinity(); \
if (x == NegativeInfinity()) \
return 0.0; \
}
#else
#define EXP_IF_OUT_OF_RANGE(x)
#endif
double
js::math_exp_impl(MathCache *cache, double x)
{
EXP_IF_OUT_OF_RANGE(x);
return cache->lookup(exp, x);
}
double
js::math_exp_uncached(double x)
{
EXP_IF_OUT_OF_RANGE(x);
return exp(x);
}
#undef EXP_IF_OUT_OF_RANGE
bool
js::math_exp(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_exp_impl(mathCache, x);
args.rval().setNumber(z);
return true;
}
double
js::math_floor_impl(double x)
{
return floor(x);
}
bool
js::math_floor(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
double z = math_floor_impl(x);
args.rval().setNumber(z);
return true;
}
bool
js::math_imul(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
uint32_t a = 0, b = 0;
if (args.hasDefined(0) && !ToUint32(cx, args[0], &a))
return false;
if (args.hasDefined(1) && !ToUint32(cx, args[1], &b))
return false;
uint32_t product = a * b;
args.rval().setInt32(product > INT32_MAX
? int32_t(INT32_MIN + (product - INT32_MAX - 1))
: int32_t(product));
return true;
}
// Implements Math.fround (20.2.2.16) up to step 3
bool
js::RoundFloat32(JSContext *cx, Handle<Value> v, float *out)
{
double d;
bool success = ToNumber(cx, v, &d);
*out = static_cast<float>(d);
return success;
}
bool
js::math_fround(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
float f;
if (!RoundFloat32(cx, args[0], &f))
return false;
args.rval().setDouble(static_cast<double>(f));
return true;
}
#if defined(SOLARIS) && defined(__GNUC__)
#define LOG_IF_OUT_OF_RANGE(x) if (x < 0) return GenericNaN();
#else
#define LOG_IF_OUT_OF_RANGE(x)
#endif
double
js::math_log_impl(MathCache *cache, double x)
{
LOG_IF_OUT_OF_RANGE(x);
return cache->lookup(log, x);
}
double
js::math_log_uncached(double x)
{
LOG_IF_OUT_OF_RANGE(x);
return log(x);
}
#undef LOG_IF_OUT_OF_RANGE
bool
js::math_log(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_log_impl(mathCache, x);
args.rval().setNumber(z);
return true;
}
bool
js_math_max(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
double maxval = NegativeInfinity();
for (unsigned i = 0; i < args.length(); i++) {
double x;
if (!ToNumber(cx, args[i], &x))
return false;
// Math.max(num, NaN) => NaN, Math.max(-0, +0) => +0
if (x > maxval || IsNaN(x) || (x == maxval && IsNegative(maxval)))
maxval = x;
}
args.rval().setNumber(maxval);
return true;
}
bool
js_math_min(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
double minval = PositiveInfinity();
for (unsigned i = 0; i < args.length(); i++) {
double x;
if (!ToNumber(cx, args[i], &x))
return false;
// Math.min(num, NaN) => NaN, Math.min(-0, +0) => -0
if (x < minval || IsNaN(x) || (x == minval && IsNegativeZero(x)))
minval = x;
}
args.rval().setNumber(minval);
return true;
}
// Disable PGO for Math.pow() and related functions (see bug 791214).
#if defined(_MSC_VER)
# pragma optimize("g", off)
#endif
double
js::powi(double x, int y)
{
unsigned n = (y < 0) ? -y : y;
double m = x;
double p = 1;
while (true) {
if ((n & 1) != 0) p *= m;
n >>= 1;
if (n == 0) {
if (y < 0) {
// Unfortunately, we have to be careful when p has reached
// infinity in the computation, because sometimes the higher
// internal precision in the pow() implementation would have
// given us a finite p. This happens very rarely.
double result = 1.0 / p;
return (result == 0 && IsInfinite(p))
? pow(x, static_cast<double>(y)) // Avoid pow(double, int).
: result;
}
return p;
}
m *= m;
}
}
#if defined(_MSC_VER)
# pragma optimize("", on)
#endif
// Disable PGO for Math.pow() and related functions (see bug 791214).
#if defined(_MSC_VER)
# pragma optimize("g", off)
#endif
double
js::ecmaPow(double x, double y)
{
/*
* Use powi if the exponent is an integer-valued double. We don't have to
* check for NaN since a comparison with NaN is always false.
*/
int32_t yi;
if (DoubleEqualsInt32(y, &yi))
return powi(x, yi);
/*
* Because C99 and ECMA specify different behavior for pow(),
* we need to wrap the libm call to make it ECMA compliant.
*/
if (!IsFinite(y) && (x == 1.0 || x == -1.0))
return GenericNaN();
/* pow(x, +-0) is always 1, even for x = NaN (MSVC gets this wrong). */
if (y == 0)
return 1;
/*
* Special case for square roots. Note that pow(x, 0.5) != sqrt(x)
* when x = -0.0, so we have to guard for this.
*/
if (IsFinite(x) && x != 0.0) {
if (y == 0.5)
return sqrt(x);
if (y == -0.5)
return 1.0 / sqrt(x);
}
return pow(x, y);
}
#if defined(_MSC_VER)
# pragma optimize("", on)
#endif
// Disable PGO for Math.pow() and related functions (see bug 791214).
#if defined(_MSC_VER)
# pragma optimize("g", off)
#endif
bool
js_math_pow(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
double x;
if (!ToNumber(cx, args.get(0), &x))
return false;
double y;
if (!ToNumber(cx, args.get(1), &y))
return false;
double z = ecmaPow(x, y);
args.rval().setNumber(z);
return true;
}
#if defined(_MSC_VER)
# pragma optimize("", on)
#endif
static uint64_t
random_generateSeed()
{
union {
uint8_t u8[8];
uint32_t u32[2];
uint64_t u64;
} seed;
seed.u64 = 0;
#if defined(XP_WIN)
/*
* Our PRNG only uses 48 bits, so calling rand_s() twice to get 64 bits is
* probably overkill.
*/
rand_s(&seed.u32[0]);
#elif defined(XP_UNIX)
/*
* In the unlikely event we can't read /dev/urandom, there's not much we can
* do, so just mix in the fd error code and the current time.
*/
int fd = open("/dev/urandom", O_RDONLY);
MOZ_ASSERT(fd >= 0, "Can't open /dev/urandom");
if (fd >= 0) {
read(fd, seed.u8, mozilla::ArrayLength(seed.u8));
close(fd);
}
seed.u32[0] ^= fd;
#else
# error "Platform needs to implement random_generateSeed()"
#endif
seed.u32[1] ^= PRMJ_Now();
return seed.u64;
}
static const uint64_t RNG_MULTIPLIER = 0x5DEECE66DLL;
static const uint64_t RNG_ADDEND = 0xBLL;
static const uint64_t RNG_MASK = (1LL << 48) - 1;
static const double RNG_DSCALE = double(1LL << 53);
/*
* Math.random() support, lifted from java.util.Random.java.
*/
static void
random_initState(uint64_t *rngState)
{
/* Our PRNG only uses 48 bits, so squeeze our entropy into those bits. */
uint64_t seed = random_generateSeed();
seed ^= (seed >> 16);
*rngState = (seed ^ RNG_MULTIPLIER) & RNG_MASK;
}
uint64_t
random_next(uint64_t *rngState, int bits)
{
MOZ_ASSERT((*rngState & 0xffff000000000000ULL) == 0, "Bad rngState");
MOZ_ASSERT(bits > 0 && bits <= 48, "bits is out of range");
if (*rngState == 0) {
random_initState(rngState);
}
uint64_t nextstate = *rngState * RNG_MULTIPLIER;
nextstate += RNG_ADDEND;
nextstate &= RNG_MASK;
*rngState = nextstate;
return nextstate >> (48 - bits);
}
static inline double
random_nextDouble(JSContext *cx)
{
uint64_t *rng = &cx->compartment()->rngState;
return double((random_next(rng, 26) << 27) + random_next(rng, 27)) / RNG_DSCALE;
}
double
math_random_no_outparam(JSContext *cx)
{
/* Calculate random without memory traffic, for use in the JITs. */
return random_nextDouble(cx);
}
bool
js_math_random(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
double z = random_nextDouble(cx);
args.rval().setDouble(z);
return true;
}
double
js::math_round_impl(double x)
{
int32_t i;
if (DoubleIsInt32(x, &i))
return double(i);
/* Some numbers are so big that adding 0.5 would give the wrong number. */
if (ExponentComponent(x) >= 52)
return x;
return js_copysign(floor(x + 0.5), x);
}
bool /* ES5 15.8.2.15. */
js::math_round(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
double z = math_round_impl(x);
args.rval().setNumber(z);
return true;
}
double
js::math_sin_impl(MathCache *cache, double x)
{
return cache->lookup(sin, x);
}
double
js::math_sin_uncached(double x)
{
return sin(x);
}
bool
js::math_sin(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_sin_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
bool
js_math_sqrt(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = mathCache->lookup(sqrt, x);
args.rval().setDouble(z);
return true;
}
double
js::math_tan_impl(MathCache *cache, double x)
{
return cache->lookup(tan, x);
}
double
js::math_tan_uncached(double x)
{
return tan(x);
}
bool
js::math_tan(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = math_tan_impl(mathCache, x);
args.rval().setDouble(z);
return true;
}
typedef double (*UnaryMathFunctionType)(MathCache *cache, double);
template <UnaryMathFunctionType F>
static bool math_function(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNumber(GenericNaN());
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
MathCache *mathCache = cx->runtime()->getMathCache(cx);
if (!mathCache)
return false;
double z = F(mathCache, x);
args.rval().setNumber(z);
return true;
}
double
js::math_log10_impl(MathCache *cache, double x)
{
return cache->lookup(log10, x);
}
double
js::math_log10_uncached(double x)
{
return log10(x);
}
bool
js::math_log10(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_log10_impl>(cx, argc, vp);
}
#if !HAVE_LOG2
double log2(double x)
{
return log(x) / M_LN2;
}
#endif
double
js::math_log2_impl(MathCache *cache, double x)
{
return cache->lookup(log2, x);
}
double
js::math_log2_uncached(double x)
{
return log2(x);
}
bool
js::math_log2(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_log2_impl>(cx, argc, vp);
}
#if !HAVE_LOG1P
double log1p(double x)
{
if (fabs(x) < 1e-4) {
/*
* Use Taylor approx. log(1 + x) = x - x^2 / 2 + x^3 / 3 - x^4 / 4 with error x^5 / 5
* Since |x| < 10^-4, |x|^5 < 10^-20, relative error less than 10^-16
*/
double z = -(x * x * x * x) / 4 + (x * x * x) / 3 - (x * x) / 2 + x;
return z;
} else {
/* For other large enough values of x use direct computation */
return log(1.0 + x);
}
}
#endif
#ifdef __APPLE__
// Ensure that log1p(-0) is -0.
#define LOG1P_IF_OUT_OF_RANGE(x) if (x == 0) return x;
#else
#define LOG1P_IF_OUT_OF_RANGE(x)
#endif
double
js::math_log1p_impl(MathCache *cache, double x)
{
LOG1P_IF_OUT_OF_RANGE(x);
return cache->lookup(log1p, x);
}
double
js::math_log1p_uncached(double x)
{
LOG1P_IF_OUT_OF_RANGE(x);
return log1p(x);
}
#undef LOG1P_IF_OUT_OF_RANGE
bool
js::math_log1p(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_log1p_impl>(cx, argc, vp);
}
#if !HAVE_EXPM1
double expm1(double x)
{
/* Special handling for -0 */
if (x == 0.0)
return x;
if (fabs(x) < 1e-5) {
/*
* Use Taylor approx. exp(x) - 1 = x + x^2 / 2 + x^3 / 6 with error x^4 / 24
* Since |x| < 10^-5, |x|^4 < 10^-20, relative error less than 10^-15
*/
double z = (x * x * x) / 6 + (x * x) / 2 + x;
return z;
} else {
/* For other large enough values of x use direct computation */
return exp(x) - 1.0;
}
}
#endif
double
js::math_expm1_impl(MathCache *cache, double x)
{
return cache->lookup(expm1, x);
}
double
js::math_expm1_uncached(double x)
{
return expm1(x);
}
bool
js::math_expm1(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_expm1_impl>(cx, argc, vp);
}
#if !HAVE_SQRT1PM1
/* This algorithm computes sqrt(1+x)-1 for small x */
double sqrt1pm1(double x)
{
if (fabs(x) > 0.75)
return sqrt(1 + x) - 1;
return expm1(log1p(x) / 2);
}
#endif
double
js::math_cosh_impl(MathCache *cache, double x)
{
return cache->lookup(cosh, x);
}
double
js::math_cosh_uncached(double x)
{
return cosh(x);
}
bool
js::math_cosh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_cosh_impl>(cx, argc, vp);
}
double
js::math_sinh_impl(MathCache *cache, double x)
{
return cache->lookup(sinh, x);
}
double
js::math_sinh_uncached(double x)
{
return sinh(x);
}
bool
js::math_sinh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_sinh_impl>(cx, argc, vp);
}
double
js::math_tanh_impl(MathCache *cache, double x)
{
return cache->lookup(tanh, x);
}
double
js::math_tanh_uncached(double x)
{
return tanh(x);
}
bool
js::math_tanh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_tanh_impl>(cx, argc, vp);
}
#if !HAVE_ACOSH
double acosh(double x)
{
const double SQUARE_ROOT_EPSILON = sqrt(std::numeric_limits<double>::epsilon());
if ((x - 1) >= SQUARE_ROOT_EPSILON) {
if (x > 1 / SQUARE_ROOT_EPSILON) {
/*
* http://functions.wolfram.com/ElementaryFunctions/ArcCosh/06/01/06/01/0001/
* approximation by laurent series in 1/x at 0+ order from -1 to 0
*/
return log(x) + M_LN2;
} else if (x < 1.5) {
// This is just a rearrangement of the standard form below
// devised to minimize loss of precision when x ~ 1:
double y = x - 1;
return log1p(y + sqrt(y * y + 2 * y));
} else {
// http://functions.wolfram.com/ElementaryFunctions/ArcCosh/02/
return log(x + sqrt(x * x - 1));
}
} else {
// see http://functions.wolfram.com/ElementaryFunctions/ArcCosh/06/01/04/01/0001/
double y = x - 1;
// approximation by taylor series in y at 0 up to order 2.
// If x is less than 1, sqrt(2 * y) is NaN and the result is NaN.
return sqrt(2 * y) * (1 - y / 12 + 3 * y * y / 160);
}
}
#endif
double
js::math_acosh_impl(MathCache *cache, double x)
{
return cache->lookup(acosh, x);
}
double
js::math_acosh_uncached(double x)
{
return acosh(x);
}
bool
js::math_acosh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_acosh_impl>(cx, argc, vp);
}
#if !HAVE_ASINH
// Bug 899712 - gcc incorrectly rewrites -asinh(-x) to asinh(x) when overriding
// asinh.
static double my_asinh(double x)
{
const double SQUARE_ROOT_EPSILON = sqrt(std::numeric_limits<double>::epsilon());
const double FOURTH_ROOT_EPSILON = sqrt(SQUARE_ROOT_EPSILON);
if (x >= FOURTH_ROOT_EPSILON) {
if (x > 1 / SQUARE_ROOT_EPSILON)
// http://functions.wolfram.com/ElementaryFunctions/ArcSinh/06/01/06/01/0001/
// approximation by laurent series in 1/x at 0+ order from -1 to 1
return M_LN2 + log(x) + 1 / (4 * x * x);
else if (x < 0.5)
return log1p(x + sqrt1pm1(x * x));
else
return log(x + sqrt(x * x + 1));
} else if (x <= -FOURTH_ROOT_EPSILON) {
return -my_asinh(-x);
} else {
// http://functions.wolfram.com/ElementaryFunctions/ArcSinh/06/01/03/01/0001/
// approximation by taylor series in x at 0 up to order 2
double result = x;
if (fabs(x) >= SQUARE_ROOT_EPSILON) {
double x3 = x * x * x;
// approximation by taylor series in x at 0 up to order 4
result -= x3 / 6;
}
return result;
}
}
#endif
double
js::math_asinh_impl(MathCache *cache, double x)
{
#ifdef HAVE_ASINH
return cache->lookup(asinh, x);
#else
return cache->lookup(my_asinh, x);
#endif
}
double
js::math_asinh_uncached(double x)
{
#ifdef HAVE_ASINH
return asinh(x);
#else
return my_asinh(x);
#endif
}
bool
js::math_asinh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_asinh_impl>(cx, argc, vp);
}
#if !HAVE_ATANH
double atanh(double x)
{
const double EPSILON = std::numeric_limits<double>::epsilon();
const double SQUARE_ROOT_EPSILON = sqrt(EPSILON);
const double FOURTH_ROOT_EPSILON = sqrt(SQUARE_ROOT_EPSILON);
if (fabs(x) >= FOURTH_ROOT_EPSILON) {
// http://functions.wolfram.com/ElementaryFunctions/ArcTanh/02/
if (fabs(x) < 0.5)
return (log1p(x) - log1p(-x)) / 2;
return log((1 + x) / (1 - x)) / 2;
} else {
// http://functions.wolfram.com/ElementaryFunctions/ArcTanh/06/01/03/01/
// approximation by taylor series in x at 0 up to order 2
double result = x;
if (fabs(x) >= SQUARE_ROOT_EPSILON) {
double x3 = x * x * x;
result += x3 / 3;
}
return result;
}
}
#endif
double
js::math_atanh_impl(MathCache *cache, double x)
{
return cache->lookup(atanh, x);
}
double
js::math_atanh_uncached(double x)
{
return atanh(x);
}
bool
js::math_atanh(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_atanh_impl>(cx, argc, vp);
}
/* Consistency wrapper for platform deviations in hypot() */
double
js::ecmaHypot(double x, double y)
{
#ifdef XP_WIN
/*
* Workaround MS hypot bug, where hypot(Infinity, NaN or Math.MIN_VALUE)
* is NaN, not Infinity.
*/
if (mozilla::IsInfinite(x) || mozilla::IsInfinite(y)) {
return mozilla::PositiveInfinity();
}
#endif
return hypot(x, y);
}
bool
js::math_hypot(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
// IonMonkey calls the system hypot function directly if two arguments are
// given. Do that here as well to get the same results.
if (args.length() == 2) {
double x, y;
if (!ToNumber(cx, args[0], &x))
return false;
if (!ToNumber(cx, args[1], &y))
return false;
double result = ecmaHypot(x, y);
args.rval().setNumber(result);
return true;
}
bool isInfinite = false;
bool isNaN = false;
double scale = 0;
double sumsq = 1;
for (unsigned i = 0; i < args.length(); i++) {
double x;
if (!ToNumber(cx, args[i], &x))
return false;
isInfinite |= mozilla::IsInfinite(x);
isNaN |= mozilla::IsNaN(x);
double xabs = mozilla::Abs(x);
if (scale < xabs) {
sumsq = 1 + sumsq * (scale / xabs) * (scale / xabs);
scale = xabs;
} else if (scale != 0) {
sumsq += (xabs / scale) * (xabs / scale);
}
}
double result = isInfinite ? PositiveInfinity() :
isNaN ? GenericNaN() :
scale * sqrt(sumsq);
args.rval().setNumber(result);
return true;
}
#if !HAVE_TRUNC
double trunc(double x)
{
return x > 0 ? floor(x) : ceil(x);
}
#endif
double
js::math_trunc_impl(MathCache *cache, double x)
{
return cache->lookup(trunc, x);
}
double
js::math_trunc_uncached(double x)
{
return trunc(x);
}
bool
js::math_trunc(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_trunc_impl>(cx, argc, vp);
}
static double sign(double x)
{
if (mozilla::IsNaN(x))
return GenericNaN();
return x == 0 ? x : x < 0 ? -1 : 1;
}
double
js::math_sign_impl(MathCache *cache, double x)
{
return cache->lookup(sign, x);
}
double
js::math_sign_uncached(double x)
{
return sign(x);
}
bool
js::math_sign(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_sign_impl>(cx, argc, vp);
}
#if !HAVE_CBRT
double cbrt(double x)
{
if (x > 0) {
return pow(x, 1.0 / 3.0);
} else if (x == 0) {
return x;
} else {
return -pow(-x, 1.0 / 3.0);
}
}
#endif
double
js::math_cbrt_impl(MathCache *cache, double x)
{
return cache->lookup(cbrt, x);
}
double
js::math_cbrt_uncached(double x)
{
return cbrt(x);
}
bool
js::math_cbrt(JSContext *cx, unsigned argc, Value *vp)
{
return math_function<math_cbrt_impl>(cx, argc, vp);
}
#if JS_HAS_TOSOURCE
static bool
math_toSource(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
args.rval().setString(cx->names().Math);
return true;
}
#endif
static const JSFunctionSpec math_static_methods[] = {
#if JS_HAS_TOSOURCE
JS_FN(js_toSource_str, math_toSource, 0, 0),
#endif
JS_FN("abs", js_math_abs, 1, 0),
JS_FN("acos", math_acos, 1, 0),
JS_FN("asin", math_asin, 1, 0),
JS_FN("atan", math_atan, 1, 0),
JS_FN("atan2", math_atan2, 2, 0),
JS_FN("ceil", math_ceil, 1, 0),
JS_FN("cos", math_cos, 1, 0),
JS_FN("exp", math_exp, 1, 0),
JS_FN("floor", math_floor, 1, 0),
JS_FN("imul", math_imul, 2, 0),
JS_FN("fround", math_fround, 1, 0),
JS_FN("log", math_log, 1, 0),
JS_FN("max", js_math_max, 2, 0),
JS_FN("min", js_math_min, 2, 0),
JS_FN("pow", js_math_pow, 2, 0),
JS_FN("random", js_math_random, 0, 0),
JS_FN("round", math_round, 1, 0),
JS_FN("sin", math_sin, 1, 0),
JS_FN("sqrt", js_math_sqrt, 1, 0),
JS_FN("tan", math_tan, 1, 0),
JS_FN("log10", math_log10, 1, 0),
JS_FN("log2", math_log2, 1, 0),
JS_FN("log1p", math_log1p, 1, 0),
JS_FN("expm1", math_expm1, 1, 0),
JS_FN("cosh", math_cosh, 1, 0),
JS_FN("sinh", math_sinh, 1, 0),
JS_FN("tanh", math_tanh, 1, 0),
JS_FN("acosh", math_acosh, 1, 0),
JS_FN("asinh", math_asinh, 1, 0),
JS_FN("atanh", math_atanh, 1, 0),
JS_FN("hypot", math_hypot, 2, 0),
JS_FN("trunc", math_trunc, 1, 0),
JS_FN("sign", math_sign, 1, 0),
JS_FN("cbrt", math_cbrt, 1, 0),
JS_FS_END
};
JSObject *
js_InitMathClass(JSContext *cx, HandleObject obj)
{
RootedObject proto(cx, obj->as<GlobalObject>().getOrCreateObjectPrototype(cx));
if (!proto)
return nullptr;
RootedObject Math(cx, NewObjectWithGivenProto(cx, &MathClass, proto, obj, SingletonObject));
if (!Math)
return nullptr;
if (!JS_DefineProperty(cx, obj, js_Math_str, OBJECT_TO_JSVAL(Math),
JS_PropertyStub, JS_StrictPropertyStub, 0)) {
return nullptr;
}
if (!JS_DefineFunctions(cx, Math, math_static_methods))
return nullptr;
if (!JS_DefineConstDoubles(cx, Math, math_constants))
return nullptr;
obj->as<GlobalObject>().setConstructor(JSProto_Math, ObjectValue(*Math));
return Math;
}
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