Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1090 insertions, 0 deletions

diff --git a/js/src/jsmath.cpp b/js/src/jsmath.cpp
new file mode 100644
index 0000000000..e01951bc7f
--- /dev/null
+++ b/js/src/jsmath.cpp
@@ -0,0 +1,1090 @@
+/* -*- 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/. */
+
+/*
+ * JS math package.
+ */
+
+#include "jsmath.h"
+
+#include "mozilla/CheckedInt.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/RandomNum.h"
+#include "mozilla/WrappingOperations.h"
+
+#include <cmath>
+
+#include "fdlibm.h"
+#include "jsapi.h"
+#include "jstypes.h"
+
+#include "jit/InlinableNatives.h"
+#include "js/Class.h"
+#include "js/PropertySpec.h"
+#include "util/DifferentialTesting.h"
+#include "vm/JSContext.h"
+#include "vm/Realm.h"
+#include "vm/Time.h"
+#include "vm/WellKnownAtom.h"  // js_*_str
+
+#include "vm/JSObject-inl.h"
+
+using namespace js;
+
+using JS::GenericNaN;
+using JS::ToNumber;
+using mozilla::ExponentComponent;
+using mozilla::FloatingPoint;
+using mozilla::IsNegative;
+using mozilla::IsNegativeZero;
+using mozilla::Maybe;
+using mozilla::NegativeInfinity;
+using mozilla::NumberEqualsInt32;
+using mozilla::NumberEqualsInt64;
+using mozilla::PositiveInfinity;
+using mozilla::WrappingMultiply;
+
+static mozilla::Atomic<bool, mozilla::Relaxed> sUseFdlibmForSinCosTan;
+
+JS_PUBLIC_API void JS::SetUseFdlibmForSinCosTan(bool value) {
+  sUseFdlibmForSinCosTan = value;
+}
+
+bool js::math_use_fdlibm_for_sin_cos_tan() { return sUseFdlibmForSinCosTan; }
+
+static inline bool UseFdlibmForSinCosTan(const CallArgs& args) {
+  return sUseFdlibmForSinCosTan ||
+         args.callee().nonCCWRealm()->behaviors().shouldResistFingerprinting();
+}
+
+template <UnaryMathFunctionType F>
+static bool math_function(JSContext* cx, CallArgs& args) {
+  if (args.length() == 0) {
+    args.rval().setNaN();
+    return true;
+  }
+
+  double x;
+  if (!ToNumber(cx, args[0], &x)) {
+    return false;
+  }
+
+  // TODO(post-Warp): Re-evaluate if it's still necessary resp. useful to always
+  // type the value as a double.
+
+  // NB: Always stored as a double so the math function can be inlined
+  // through MMathFunction.
+  double z = F(x);
+  args.rval().setDouble(z);
+  return true;
+}
+
+double js::math_abs_impl(double x) { return mozilla::Abs(x); }
+
+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;
+  }
+
+  args.rval().setNumber(math_abs_impl(x));
+  return true;
+}
+
+double js::math_acos_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::acos(x);
+}
+
+static bool math_acos(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_acos_impl>(cx, args);
+}
+
+double js::math_asin_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::asin(x);
+}
+
+static bool math_asin(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_asin_impl>(cx, args);
+}
+
+double js::math_atan_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::atan(x);
+}
+
+static bool math_atan(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_atan_impl>(cx, args);
+}
+
+double js::ecmaAtan2(double y, double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::atan2(y, x);
+}
+
+static bool 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) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::ceil(x);
+}
+
+static bool 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;
+  }
+
+  args.rval().setNumber(math_ceil_impl(x));
+  return true;
+}
+
+static bool math_clz32(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (args.length() == 0) {
+    args.rval().setInt32(32);
+    return true;
+  }
+
+  uint32_t n;
+  if (!ToUint32(cx, args[0], &n)) {
+    return false;
+  }
+
+  if (n == 0) {
+    args.rval().setInt32(32);
+    return true;
+  }
+
+  args.rval().setInt32(mozilla::CountLeadingZeroes32(n));
+  return true;
+}
+
+double js::math_cos_fdlibm_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::cos(x);
+}
+
+double js::math_cos_native_impl(double x) {
+  MOZ_ASSERT(!sUseFdlibmForSinCosTan);
+  AutoUnsafeCallWithABI unsafe;
+  return std::cos(x);
+}
+
+static bool math_cos(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  if (UseFdlibmForSinCosTan(args)) {
+    return math_function<math_cos_fdlibm_impl>(cx, args);
+  }
+  return math_function<math_cos_native_impl>(cx, args);
+}
+
+double js::math_exp_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::exp(x);
+}
+
+static bool math_exp(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_exp_impl>(cx, args);
+}
+
+double js::math_floor_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::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;
+  }
+
+  args.rval().setNumber(math_floor_impl(x));
+  return true;
+}
+
+bool js::math_imul_handle(JSContext* cx, HandleValue lhs, HandleValue rhs,
+                          MutableHandleValue res) {
+  int32_t a = 0, b = 0;
+  if (!lhs.isUndefined() && !ToInt32(cx, lhs, &a)) {
+    return false;
+  }
+  if (!rhs.isUndefined() && !ToInt32(cx, rhs, &b)) {
+    return false;
+  }
+
+  res.setInt32(WrappingMultiply(a, b));
+  return true;
+}
+
+static bool math_imul(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  return math_imul_handle(cx, args.get(0), args.get(1), args.rval());
+}
+
+// Implements Math.fround (20.2.2.16) up to step 3
+bool js::RoundFloat32(JSContext* cx, HandleValue v, float* out) {
+  double d;
+  bool success = ToNumber(cx, v, &d);
+  *out = static_cast<float>(d);
+  return success;
+}
+
+bool js::RoundFloat32(JSContext* cx, HandleValue arg, MutableHandleValue res) {
+  float f;
+  if (!RoundFloat32(cx, arg, &f)) {
+    return false;
+  }
+
+  res.setDouble(static_cast<double>(f));
+  return true;
+}
+
+double js::RoundFloat32(double d) {
+  return static_cast<double>(static_cast<float>(d));
+}
+
+static bool math_fround(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (args.length() == 0) {
+    args.rval().setNaN();
+    return true;
+  }
+
+  return RoundFloat32(cx, args[0], args.rval());
+}
+
+double js::math_log_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::log(x);
+}
+
+static bool math_log(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_log_impl>(cx, args);
+}
+
+double js::math_max_impl(double x, double y) {
+  AutoUnsafeCallWithABI unsafe;
+
+  // Math.max(num, NaN) => NaN, Math.max(-0, +0) => +0
+  if (x > y || std::isnan(x) || (x == y && IsNegative(y))) {
+    return x;
+  }
+  return y;
+}
+
+bool js::math_max(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  double maxval = NegativeInfinity<double>();
+  for (unsigned i = 0; i < args.length(); i++) {
+    double x;
+    if (!ToNumber(cx, args[i], &x)) {
+      return false;
+    }
+    maxval = math_max_impl(x, maxval);
+  }
+  args.rval().setNumber(maxval);
+  return true;
+}
+
+double js::math_min_impl(double x, double y) {
+  AutoUnsafeCallWithABI unsafe;
+
+  // Math.min(num, NaN) => NaN, Math.min(-0, +0) => -0
+  if (x < y || std::isnan(x) || (x == y && IsNegativeZero(x))) {
+    return x;
+  }
+  return y;
+}
+
+bool js::math_min(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  double minval = PositiveInfinity<double>();
+  for (unsigned i = 0; i < args.length(); i++) {
+    double x;
+    if (!ToNumber(cx, args[i], &x)) {
+      return false;
+    }
+    minval = math_min_impl(x, minval);
+  }
+  args.rval().setNumber(minval);
+  return true;
+}
+
+double js::powi(double x, int32_t y) {
+  AutoUnsafeCallWithABI unsafe;
+
+  // It's only safe to optimize this when we can compute with integer values or
+  // the exponent is a small, positive constant.
+  if (y >= 0) {
+    uint32_t n = uint32_t(y);
+
+    // NB: Have to take fast-path for n <= 4 to match |MPow::foldsTo|. Otherwise
+    // we risk causing differential testing issues.
+    if (n == 0) {
+      return 1;
+    }
+    if (n == 1) {
+      return x;
+    }
+    if (n == 2) {
+      return x * x;
+    }
+    if (n == 3) {
+      return x * x * x;
+    }
+    if (n == 4) {
+      double z = x * x;
+      return z * z;
+    }
+
+    int64_t i;
+    if (NumberEqualsInt64(x, &i)) {
+      // Special-case: |-0 ** odd| is -0.
+      if (i == 0) {
+        return (n & 1) ? x : 0;
+      }
+
+      // Use int64 to cover cases like |Math.pow(2, 53)|.
+      mozilla::CheckedInt64 runningSquare = i;
+      mozilla::CheckedInt64 result = 1;
+      while (true) {
+        if ((n & 1) != 0) {
+          result *= runningSquare;
+          if (!result.isValid()) {
+            break;
+          }
+        }
+
+        n >>= 1;
+        if (n == 0) {
+          return static_cast<double>(result.value());
+        }
+
+        runningSquare *= runningSquare;
+        if (!runningSquare.isValid()) {
+          break;
+        }
+      }
+    }
+
+    // Fall-back to use std::pow to reduce floating point precision errors.
+  }
+
+  return std::pow(x, static_cast<double>(y));  // Avoid pow(double, int).
+}
+
+double js::ecmaPow(double x, double y) {
+  AutoUnsafeCallWithABI unsafe;
+
+  /*
+   * 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 (NumberEqualsInt32(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 (!std::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 (std::isfinite(x) && x != 0.0) {
+    if (y == 0.5) {
+      return std::sqrt(x);
+    }
+    if (y == -0.5) {
+      return 1.0 / std::sqrt(x);
+    }
+  }
+  return std::pow(x, y);
+}
+
+static bool 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;
+}
+
+uint64_t js::GenerateRandomSeed() {
+  Maybe<uint64_t> maybeSeed = mozilla::RandomUint64();
+
+  return maybeSeed.valueOrFrom([] {
+    // Use PRMJ_Now() in case we couldn't read random bits from the OS.
+    uint64_t timestamp = PRMJ_Now();
+    return timestamp ^ (timestamp << 32);
+  });
+}
+
+void js::GenerateXorShift128PlusSeed(mozilla::Array<uint64_t, 2>& seed) {
+  // XorShift128PlusRNG must be initialized with a non-zero seed.
+  do {
+    seed[0] = GenerateRandomSeed();
+    seed[1] = GenerateRandomSeed();
+  } while (seed[0] == 0 && seed[1] == 0);
+}
+
+mozilla::non_crypto::XorShift128PlusRNG&
+Realm::getOrCreateRandomNumberGenerator() {
+  if (randomNumberGenerator_.isNothing()) {
+    mozilla::Array<uint64_t, 2> seed;
+    GenerateXorShift128PlusSeed(seed);
+    randomNumberGenerator_.emplace(seed[0], seed[1]);
+  }
+
+  return randomNumberGenerator_.ref();
+}
+
+double js::math_random_impl(JSContext* cx) {
+  return cx->realm()->getOrCreateRandomNumberGenerator().nextDouble();
+}
+
+static bool math_random(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  if (js::SupportDifferentialTesting()) {
+    args.rval().setDouble(0);
+  } else {
+    args.rval().setDouble(math_random_impl(cx));
+  }
+  return true;
+}
+
+template <typename T>
+T js::GetBiggestNumberLessThan(T x) {
+  MOZ_ASSERT(!IsNegative(x));
+  MOZ_ASSERT(std::isfinite(x));
+  using Bits = typename mozilla::FloatingPoint<T>::Bits;
+  Bits bits = mozilla::BitwiseCast<Bits>(x);
+  MOZ_ASSERT(bits > 0, "will underflow");
+  return mozilla::BitwiseCast<T>(bits - 1);
+}
+
+template double js::GetBiggestNumberLessThan<>(double x);
+template float js::GetBiggestNumberLessThan<>(float x);
+
+double js::math_round_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+
+  int32_t ignored;
+  if (NumberEqualsInt32(x, &ignored)) {
+    return x;
+  }
+
+  /* Some numbers are so big that adding 0.5 would give the wrong number. */
+  if (ExponentComponent(x) >=
+      int_fast16_t(FloatingPoint<double>::kExponentShift)) {
+    return x;
+  }
+
+  double add = (x >= 0) ? GetBiggestNumberLessThan(0.5) : 0.5;
+  return std::copysign(fdlibm::floor(x + add), x);
+}
+
+float js::math_roundf_impl(float x) {
+  AutoUnsafeCallWithABI unsafe;
+
+  int32_t ignored;
+  if (NumberEqualsInt32(x, &ignored)) {
+    return x;
+  }
+
+  /* Some numbers are so big that adding 0.5 would give the wrong number. */
+  if (ExponentComponent(x) >=
+      int_fast16_t(FloatingPoint<float>::kExponentShift)) {
+    return x;
+  }
+
+  float add = (x >= 0) ? GetBiggestNumberLessThan(0.5f) : 0.5f;
+  return std::copysign(fdlibm::floorf(x + add), x);
+}
+
+/* ES5 15.8.2.15. */
+static bool 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;
+  }
+
+  args.rval().setNumber(math_round_impl(x));
+  return true;
+}
+
+double js::math_sin_fdlibm_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::sin(x);
+}
+
+double js::math_sin_native_impl(double x) {
+  MOZ_ASSERT(!sUseFdlibmForSinCosTan);
+  AutoUnsafeCallWithABI unsafe;
+  return std::sin(x);
+}
+
+static bool math_sin(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  if (UseFdlibmForSinCosTan(args)) {
+    return math_function<math_sin_fdlibm_impl>(cx, args);
+  }
+  return math_function<math_sin_native_impl>(cx, args);
+}
+
+double js::math_sqrt_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return std::sqrt(x);
+}
+
+static bool math_sqrt(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_sqrt_impl>(cx, args);
+}
+
+double js::math_tan_fdlibm_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::tan(x);
+}
+
+double js::math_tan_native_impl(double x) {
+  MOZ_ASSERT(!sUseFdlibmForSinCosTan);
+  AutoUnsafeCallWithABI unsafe;
+  return std::tan(x);
+}
+
+static bool math_tan(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  if (UseFdlibmForSinCosTan(args)) {
+    return math_function<math_tan_fdlibm_impl>(cx, args);
+  }
+  return math_function<math_tan_native_impl>(cx, args);
+}
+
+double js::math_log10_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::log10(x);
+}
+
+static bool math_log10(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_log10_impl>(cx, args);
+}
+
+double js::math_log2_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::log2(x);
+}
+
+static bool math_log2(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_log2_impl>(cx, args);
+}
+
+double js::math_log1p_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::log1p(x);
+}
+
+static bool math_log1p(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_log1p_impl>(cx, args);
+}
+
+double js::math_expm1_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::expm1(x);
+}
+
+static bool math_expm1(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_expm1_impl>(cx, args);
+}
+
+double js::math_cosh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::cosh(x);
+}
+
+static bool math_cosh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_cosh_impl>(cx, args);
+}
+
+double js::math_sinh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::sinh(x);
+}
+
+static bool math_sinh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_sinh_impl>(cx, args);
+}
+
+double js::math_tanh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::tanh(x);
+}
+
+static bool math_tanh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_tanh_impl>(cx, args);
+}
+
+double js::math_acosh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::acosh(x);
+}
+
+static bool math_acosh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_acosh_impl>(cx, args);
+}
+
+double js::math_asinh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::asinh(x);
+}
+
+static bool math_asinh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_asinh_impl>(cx, args);
+}
+
+double js::math_atanh_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::atanh(x);
+}
+
+static bool math_atanh(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_atanh_impl>(cx, args);
+}
+
+double js::ecmaHypot(double x, double y) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::hypot(x, y);
+}
+
+static inline void hypot_step(double& scale, double& sumsq, double 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 js::hypot4(double x, double y, double z, double w) {
+  AutoUnsafeCallWithABI unsafe;
+
+  // Check for infinities or NaNs so that we can return immediately.
+  if (std::isinf(x) || std::isinf(y) || std::isinf(z) || std::isinf(w)) {
+    return mozilla::PositiveInfinity<double>();
+  }
+
+  if (std::isnan(x) || std::isnan(y) || std::isnan(z) || std::isnan(w)) {
+    return GenericNaN();
+  }
+
+  double scale = 0;
+  double sumsq = 1;
+
+  hypot_step(scale, sumsq, x);
+  hypot_step(scale, sumsq, y);
+  hypot_step(scale, sumsq, z);
+  hypot_step(scale, sumsq, w);
+
+  return scale * std::sqrt(sumsq);
+}
+
+double js::hypot3(double x, double y, double z) {
+  AutoUnsafeCallWithABI unsafe;
+  return hypot4(x, y, z, 0.0);
+}
+
+static bool math_hypot(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_hypot_handle(cx, args, args.rval());
+}
+
+bool js::math_hypot_handle(JSContext* cx, HandleValueArray args,
+                           MutableHandleValue res) {
+  // IonMonkey calls the ecmaHypot 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);
+    res.setDouble(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 |= std::isinf(x);
+    isNaN |= std::isnan(x);
+    if (isInfinite || isNaN) {
+      continue;
+    }
+
+    hypot_step(scale, sumsq, x);
+  }
+
+  double result = isInfinite ? PositiveInfinity<double>()
+                  : isNaN    ? GenericNaN()
+                             : scale * std::sqrt(sumsq);
+  res.setDouble(result);
+  return true;
+}
+
+double js::math_trunc_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::trunc(x);
+}
+
+float js::math_truncf_impl(float x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::truncf(x);
+}
+
+bool js::math_trunc(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;
+  }
+
+  args.rval().setNumber(math_trunc_impl(x));
+  return true;
+}
+
+double js::math_sign_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+
+  if (std::isnan(x)) {
+    return GenericNaN();
+  }
+
+  return x == 0 ? x : x < 0 ? -1 : 1;
+}
+
+static bool math_sign(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;
+  }
+
+  args.rval().setNumber(math_sign_impl(x));
+  return true;
+}
+
+double js::math_cbrt_impl(double x) {
+  AutoUnsafeCallWithABI unsafe;
+  return fdlibm::cbrt(x);
+}
+
+static bool math_cbrt(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return math_function<math_cbrt_impl>(cx, args);
+}
+
+static bool math_toSource(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  args.rval().setString(cx->names().Math);
+  return true;
+}
+
+UnaryMathFunctionType js::GetUnaryMathFunctionPtr(UnaryMathFunction fun) {
+  switch (fun) {
+    case UnaryMathFunction::SinNative:
+      return math_sin_native_impl;
+    case UnaryMathFunction::SinFdlibm:
+      return math_sin_fdlibm_impl;
+    case UnaryMathFunction::CosNative:
+      return math_cos_native_impl;
+    case UnaryMathFunction::CosFdlibm:
+      return math_cos_fdlibm_impl;
+    case UnaryMathFunction::TanNative:
+      return math_tan_native_impl;
+    case UnaryMathFunction::TanFdlibm:
+      return math_tan_fdlibm_impl;
+    case UnaryMathFunction::Log:
+      return math_log_impl;
+    case UnaryMathFunction::Exp:
+      return math_exp_impl;
+    case UnaryMathFunction::ATan:
+      return math_atan_impl;
+    case UnaryMathFunction::ASin:
+      return math_asin_impl;
+    case UnaryMathFunction::ACos:
+      return math_acos_impl;
+    case UnaryMathFunction::Log10:
+      return math_log10_impl;
+    case UnaryMathFunction::Log2:
+      return math_log2_impl;
+    case UnaryMathFunction::Log1P:
+      return math_log1p_impl;
+    case UnaryMathFunction::ExpM1:
+      return math_expm1_impl;
+    case UnaryMathFunction::CosH:
+      return math_cosh_impl;
+    case UnaryMathFunction::SinH:
+      return math_sinh_impl;
+    case UnaryMathFunction::TanH:
+      return math_tanh_impl;
+    case UnaryMathFunction::ACosH:
+      return math_acosh_impl;
+    case UnaryMathFunction::ASinH:
+      return math_asinh_impl;
+    case UnaryMathFunction::ATanH:
+      return math_atanh_impl;
+    case UnaryMathFunction::Trunc:
+      return math_trunc_impl;
+    case UnaryMathFunction::Cbrt:
+      return math_cbrt_impl;
+    case UnaryMathFunction::Floor:
+      return math_floor_impl;
+    case UnaryMathFunction::Ceil:
+      return math_ceil_impl;
+    case UnaryMathFunction::Round:
+      return math_round_impl;
+  }
+  MOZ_CRASH("Unknown function");
+}
+
+const char* js::GetUnaryMathFunctionName(UnaryMathFunction fun) {
+  switch (fun) {
+    case UnaryMathFunction::SinNative:
+      return "Sin (native)";
+    case UnaryMathFunction::SinFdlibm:
+      return "Sin (fdlibm)";
+    case UnaryMathFunction::CosNative:
+      return "Cos (native)";
+    case UnaryMathFunction::CosFdlibm:
+      return "Cos (fdlibm)";
+    case UnaryMathFunction::TanNative:
+      return "Tan (native)";
+    case UnaryMathFunction::TanFdlibm:
+      return "Tan (fdlibm)";
+    case UnaryMathFunction::Log:
+      return "Log";
+    case UnaryMathFunction::Exp:
+      return "Exp";
+    case UnaryMathFunction::ACos:
+      return "ACos";
+    case UnaryMathFunction::ASin:
+      return "ASin";
+    case UnaryMathFunction::ATan:
+      return "ATan";
+    case UnaryMathFunction::Log10:
+      return "Log10";
+    case UnaryMathFunction::Log2:
+      return "Log2";
+    case UnaryMathFunction::Log1P:
+      return "Log1P";
+    case UnaryMathFunction::ExpM1:
+      return "ExpM1";
+    case UnaryMathFunction::CosH:
+      return "CosH";
+    case UnaryMathFunction::SinH:
+      return "SinH";
+    case UnaryMathFunction::TanH:
+      return "TanH";
+    case UnaryMathFunction::ACosH:
+      return "ACosH";
+    case UnaryMathFunction::ASinH:
+      return "ASinH";
+    case UnaryMathFunction::ATanH:
+      return "ATanH";
+    case UnaryMathFunction::Trunc:
+      return "Trunc";
+    case UnaryMathFunction::Cbrt:
+      return "Cbrt";
+    case UnaryMathFunction::Floor:
+      return "Floor";
+    case UnaryMathFunction::Ceil:
+      return "Ceil";
+    case UnaryMathFunction::Round:
+      return "Round";
+  }
+  MOZ_CRASH("Unknown function");
+}
+
+static const JSFunctionSpec math_static_methods[] = {
+    JS_FN(js_toSource_str, math_toSource, 0, 0),
+    JS_INLINABLE_FN("abs", math_abs, 1, 0, MathAbs),
+    JS_INLINABLE_FN("acos", math_acos, 1, 0, MathACos),
+    JS_INLINABLE_FN("asin", math_asin, 1, 0, MathASin),
+    JS_INLINABLE_FN("atan", math_atan, 1, 0, MathATan),
+    JS_INLINABLE_FN("atan2", math_atan2, 2, 0, MathATan2),
+    JS_INLINABLE_FN("ceil", math_ceil, 1, 0, MathCeil),
+    JS_INLINABLE_FN("clz32", math_clz32, 1, 0, MathClz32),
+    JS_INLINABLE_FN("cos", math_cos, 1, 0, MathCos),
+    JS_INLINABLE_FN("exp", math_exp, 1, 0, MathExp),
+    JS_INLINABLE_FN("floor", math_floor, 1, 0, MathFloor),
+    JS_INLINABLE_FN("imul", math_imul, 2, 0, MathImul),
+    JS_INLINABLE_FN("fround", math_fround, 1, 0, MathFRound),
+    JS_INLINABLE_FN("log", math_log, 1, 0, MathLog),
+    JS_INLINABLE_FN("max", math_max, 2, 0, MathMax),
+    JS_INLINABLE_FN("min", math_min, 2, 0, MathMin),
+    JS_INLINABLE_FN("pow", math_pow, 2, 0, MathPow),
+    JS_INLINABLE_FN("random", math_random, 0, 0, MathRandom),
+    JS_INLINABLE_FN("round", math_round, 1, 0, MathRound),
+    JS_INLINABLE_FN("sin", math_sin, 1, 0, MathSin),
+    JS_INLINABLE_FN("sqrt", math_sqrt, 1, 0, MathSqrt),
+    JS_INLINABLE_FN("tan", math_tan, 1, 0, MathTan),
+    JS_INLINABLE_FN("log10", math_log10, 1, 0, MathLog10),
+    JS_INLINABLE_FN("log2", math_log2, 1, 0, MathLog2),
+    JS_INLINABLE_FN("log1p", math_log1p, 1, 0, MathLog1P),
+    JS_INLINABLE_FN("expm1", math_expm1, 1, 0, MathExpM1),
+    JS_INLINABLE_FN("cosh", math_cosh, 1, 0, MathCosH),
+    JS_INLINABLE_FN("sinh", math_sinh, 1, 0, MathSinH),
+    JS_INLINABLE_FN("tanh", math_tanh, 1, 0, MathTanH),
+    JS_INLINABLE_FN("acosh", math_acosh, 1, 0, MathACosH),
+    JS_INLINABLE_FN("asinh", math_asinh, 1, 0, MathASinH),
+    JS_INLINABLE_FN("atanh", math_atanh, 1, 0, MathATanH),
+    JS_INLINABLE_FN("hypot", math_hypot, 2, 0, MathHypot),
+    JS_INLINABLE_FN("trunc", math_trunc, 1, 0, MathTrunc),
+    JS_INLINABLE_FN("sign", math_sign, 1, 0, MathSign),
+    JS_INLINABLE_FN("cbrt", math_cbrt, 1, 0, MathCbrt),
+    JS_FS_END};
+
+static const JSPropertySpec math_static_properties[] = {
+    JS_DOUBLE_PS("E", M_E, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("LOG2E", M_LOG2E, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("LOG10E", M_LOG10E, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("LN2", M_LN2, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("LN10", M_LN10, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("PI", M_PI, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("SQRT2", M_SQRT2, JSPROP_READONLY | JSPROP_PERMANENT),
+    JS_DOUBLE_PS("SQRT1_2", M_SQRT1_2, JSPROP_READONLY | JSPROP_PERMANENT),
+
+    JS_STRING_SYM_PS(toStringTag, "Math", JSPROP_READONLY),
+    JS_PS_END};
+
+static JSObject* CreateMathObject(JSContext* cx, JSProtoKey key) {
+  RootedObject proto(cx, &cx->global()->getObjectPrototype());
+  return NewTenuredObjectWithGivenProto(cx, &MathClass, proto);
+}
+
+static const ClassSpec MathClassSpec = {CreateMathObject,
+                                        nullptr,
+                                        math_static_methods,
+                                        math_static_properties,
+                                        nullptr,
+                                        nullptr,
+                                        nullptr};
+
+const JSClass js::MathClass = {js_Math_str,
+                               JSCLASS_HAS_CACHED_PROTO(JSProto_Math),
+                               JS_NULL_CLASS_OPS, &MathClassSpec};