jslibmath.h
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=4 sw=4 et tw=79:
*
* 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/. */
#ifndef _LIBMATH_H
#define _LIBMATH_H
#include "mozilla/FloatingPoint.h"
#include <math.h>
#include "jsnum.h"
/*
* Use system provided math routines.
*/
/* The right copysign function is not always named the same thing. */
#ifdef __GNUC__
#define js_copysign __builtin_copysign
#elif defined _WIN32
#define js_copysign _copysign
#else
#define js_copysign copysign
#endif
#if defined(_M_X64) && defined(_MSC_VER) && _MSC_VER <= 1500
// This is a workaround for fmod bug (http://support.microsoft.com/kb/982107)
extern "C" double js_myfmod(double x, double y);
#define fmod js_myfmod
#endif
/* Consistency wrapper for platform deviations in fmod() */
static inline double
js_fmod(double d, double d2)
{
#ifdef XP_WIN
/*
* Workaround MS fmod bug where 42 % (1/0) => NaN, not 42.
* Workaround MS fmod bug where -0 % -N => 0, not -0.
*/
if ((MOZ_DOUBLE_IS_FINITE(d) && MOZ_DOUBLE_IS_INFINITE(d2)) ||
(d == 0 && MOZ_DOUBLE_IS_FINITE(d2))) {
return d;
}
#endif
return fmod(d, d2);
}
namespace js {
inline double
NumberDiv(double a, double b)
{
if (b == 0) {
if (a == 0 || MOZ_DOUBLE_IS_NaN(a)
#ifdef XP_WIN
|| MOZ_DOUBLE_IS_NaN(b) /* XXX MSVC miscompiles such that (NaN == 0) */
#endif
)
return js_NaN;
if (MOZ_DOUBLE_IS_NEGATIVE(a) != MOZ_DOUBLE_IS_NEGATIVE(b))
return js_NegativeInfinity;
return js_PositiveInfinity;
}
return a / b;
}
inline double
NumberMod(double a, double b) {
if (b == 0)
return js_NaN;
return js_fmod(a, b);
}
}
#endif /* _LIBMATH_H */