1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jslibmath.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,76 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jslibmath_h
1.11 +#define jslibmath_h
1.12 +
1.13 +#include "mozilla/FloatingPoint.h"
1.14 +
1.15 +#include <math.h>
1.16 +
1.17 +#include "jsnum.h"
1.18 +
1.19 +/*
1.20 + * Use system provided math routines.
1.21 + */
1.22 +
1.23 +/* The right copysign function is not always named the same thing. */
1.24 +#ifdef __GNUC__
1.25 +#define js_copysign __builtin_copysign
1.26 +#elif defined _WIN32
1.27 +#define js_copysign _copysign
1.28 +#else
1.29 +#define js_copysign copysign
1.30 +#endif
1.31 +
1.32 +/* Consistency wrapper for platform deviations in fmod() */
1.33 +static inline double
1.34 +js_fmod(double d, double d2)
1.35 +{
1.36 +#ifdef XP_WIN
1.37 + /*
1.38 + * Workaround MS fmod bug where 42 % (1/0) => NaN, not 42.
1.39 + * Workaround MS fmod bug where -0 % -N => 0, not -0.
1.40 + */
1.41 + if ((mozilla::IsFinite(d) && mozilla::IsInfinite(d2)) ||
1.42 + (d == 0 && mozilla::IsFinite(d2))) {
1.43 + return d;
1.44 + }
1.45 +#endif
1.46 + return fmod(d, d2);
1.47 +}
1.48 +
1.49 +namespace js {
1.50 +
1.51 +inline double
1.52 +NumberDiv(double a, double b)
1.53 +{
1.54 + if (b == 0) {
1.55 + if (a == 0 || mozilla::IsNaN(a)
1.56 +#ifdef XP_WIN
1.57 + || mozilla::IsNaN(b) /* XXX MSVC miscompiles such that (NaN == 0) */
1.58 +#endif
1.59 + )
1.60 + return JS::GenericNaN();
1.61 +
1.62 + if (mozilla::IsNegative(a) != mozilla::IsNegative(b))
1.63 + return mozilla::NegativeInfinity<double>();
1.64 + return mozilla::PositiveInfinity<double>();
1.65 + }
1.66 +
1.67 + return a / b;
1.68 +}
1.69 +
1.70 +inline double
1.71 +NumberMod(double a, double b) {
1.72 + if (b == 0)
1.73 + return JS::GenericNaN();
1.74 + return js_fmod(a, b);
1.75 +}
1.76 +
1.77 +}
1.78 +
1.79 +#endif /* jslibmath_h */
