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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * 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 jslibmath_h
+#define jslibmath_h
+
+#include "mozilla/FloatingPoint.h"
+
+#include <math.h>
+
+#include "js/Value.h"
+#include "vm/JSContext.h"
+
+namespace js {
+
+inline double NumberDiv(double a, double b) {
+ AutoUnsafeCallWithABI unsafe;
+ if (b == 0) {
+ if (a == 0 || std::isnan(a)) {
+ return JS::GenericNaN();
+ }
+ if (mozilla::IsNegative(a) != mozilla::IsNegative(b)) {
+ return mozilla::NegativeInfinity<double>();
+ }
+ return mozilla::PositiveInfinity<double>();
+ }
+
+ return a / b;
+}
+
+inline double NumberMod(double a, double b) {
+ AutoUnsafeCallWithABI unsafe;
+ if (b == 0) {
+ return JS::GenericNaN();
+ }
+ double r = fmod(a, b);
+#if defined(XP_WIN)
+ // Some versions of Windows (Win 10 v1803, v1809) miscompute the sign of zero
+ // results from fmod. The sign should match the sign of the LHS. This bug
+ // only affects 64-bit builds. See bug 1527007.
+ if (mozilla::IsPositiveZero(r) && mozilla::IsNegative(a)) {
+ return -0.0;
+ }
+#endif
+ return r;
+}
+
+} // namespace js
+
+#endif /* jslibmath_h */