michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef jslibmath_h
michael@0: #define jslibmath_h
michael@0: 
michael@0: #include "mozilla/FloatingPoint.h"
michael@0: 
michael@0: #include <math.h>
michael@0: 
michael@0: #include "jsnum.h"
michael@0: 
michael@0: /*
michael@0:  * Use system provided math routines.
michael@0:  */
michael@0: 
michael@0: /* The right copysign function is not always named the same thing. */
michael@0: #ifdef __GNUC__
michael@0: #define js_copysign __builtin_copysign
michael@0: #elif defined _WIN32
michael@0: #define js_copysign _copysign
michael@0: #else
michael@0: #define js_copysign copysign
michael@0: #endif
michael@0: 
michael@0: /* Consistency wrapper for platform deviations in fmod() */
michael@0: static inline double
michael@0: js_fmod(double d, double d2)
michael@0: {
michael@0: #ifdef XP_WIN
michael@0:     /*
michael@0:      * Workaround MS fmod bug where 42 % (1/0) => NaN, not 42.
michael@0:      * Workaround MS fmod bug where -0 % -N => 0, not -0.
michael@0:      */
michael@0:     if ((mozilla::IsFinite(d) && mozilla::IsInfinite(d2)) ||
michael@0:         (d == 0 && mozilla::IsFinite(d2))) {
michael@0:         return d;
michael@0:     }
michael@0: #endif
michael@0:     return fmod(d, d2);
michael@0: }
michael@0: 
michael@0: namespace js {
michael@0: 
michael@0: inline double
michael@0: NumberDiv(double a, double b)
michael@0: {
michael@0:     if (b == 0) {
michael@0:         if (a == 0 || mozilla::IsNaN(a)
michael@0: #ifdef XP_WIN
michael@0:             || mozilla::IsNaN(b) /* XXX MSVC miscompiles such that (NaN == 0) */
michael@0: #endif
michael@0:         )
michael@0:             return JS::GenericNaN();
michael@0: 
michael@0:         if (mozilla::IsNegative(a) != mozilla::IsNegative(b))
michael@0:             return mozilla::NegativeInfinity<double>();
michael@0:         return mozilla::PositiveInfinity<double>();
michael@0:     }
michael@0: 
michael@0:     return a / b;
michael@0: }
michael@0: 
michael@0: inline double
michael@0: NumberMod(double a, double b) {
michael@0:     if (b == 0)
michael@0:         return JS::GenericNaN();
michael@0:     return js_fmod(a, b);
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: #endif /* jslibmath_h */