Adding upstream version 124.0.1.upstream/124.0.1

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

13 files changed, 2386 insertions, 0 deletions

diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
new file mode 100644
index 0000000000..7d2bcfa712
--- /dev/null
+++ b/mozglue/misc/decimal/Decimal.cpp
@@ -0,0 +1,1017 @@
+/*
+ * Copyright (C) 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Decimal.h"
+#include "moz-decimal-utils.h"
+#include "DoubleConversion.h"
+
+using namespace moz_decimal_utils;
+
+#include <algorithm>
+#include <float.h>
+
+namespace blink {
+
+namespace DecimalPrivate {
+
+// This class handles Decimal special values.
+class SpecialValueHandler {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(SpecialValueHandler);
+public:
+    enum HandleResult {
+        BothFinite,
+        BothInfinity,
+        EitherNaN,
+        LHSIsInfinity,
+        RHSIsInfinity,
+    };
+
+    SpecialValueHandler(const Decimal& lhs, const Decimal& rhs);
+    HandleResult handle();
+    Decimal value() const;
+
+private:
+    enum Result {
+        ResultIsLHS,
+        ResultIsRHS,
+        ResultIsUnknown,
+    };
+
+    const Decimal& m_lhs;
+    const Decimal& m_rhs;
+    Result m_result;
+};
+
+SpecialValueHandler::SpecialValueHandler(const Decimal& lhs, const Decimal& rhs)
+    : m_lhs(lhs), m_rhs(rhs), m_result(ResultIsUnknown)
+{
+}
+
+SpecialValueHandler::HandleResult SpecialValueHandler::handle()
+{
+    if (m_lhs.isFinite() && m_rhs.isFinite())
+        return BothFinite;
+
+    const Decimal::EncodedData::FormatClass lhsClass = m_lhs.value().formatClass();
+    const Decimal::EncodedData::FormatClass rhsClass = m_rhs.value().formatClass();
+    if (lhsClass == Decimal::EncodedData::ClassNaN) {
+        m_result = ResultIsLHS;
+        return EitherNaN;
+    }
+
+    if (rhsClass == Decimal::EncodedData::ClassNaN) {
+        m_result = ResultIsRHS;
+        return EitherNaN;
+    }
+
+    if (lhsClass == Decimal::EncodedData::ClassInfinity)
+        return rhsClass == Decimal::EncodedData::ClassInfinity ? BothInfinity : LHSIsInfinity;
+
+    if (rhsClass == Decimal::EncodedData::ClassInfinity)
+        return RHSIsInfinity;
+
+    ASSERT_NOT_REACHED();
+    return BothFinite;
+}
+
+Decimal SpecialValueHandler::value() const
+{
+    switch (m_result) {
+    case ResultIsLHS:
+        return m_lhs;
+    case ResultIsRHS:
+        return m_rhs;
+    case ResultIsUnknown:
+    default:
+        ASSERT_NOT_REACHED();
+        return m_lhs;
+    }
+}
+
+// This class is used for 128 bit unsigned integer arithmetic.
+class UInt128 {
+public:
+    UInt128(uint64_t low, uint64_t high)
+        : m_high(high), m_low(low)
+    {
+    }
+
+    UInt128& operator/=(uint32_t);
+
+    uint64_t high() const { return m_high; }
+    uint64_t low() const { return m_low; }
+
+    static UInt128 multiply(uint64_t u, uint64_t v) { return UInt128(u * v, multiplyHigh(u, v)); }
+
+private:
+    static uint32_t highUInt32(uint64_t x) { return static_cast<uint32_t>(x >> 32); }
+    static uint32_t lowUInt32(uint64_t x) { return static_cast<uint32_t>(x & ((static_cast<uint64_t>(1) << 32) - 1)); }
+    static uint64_t makeUInt64(uint32_t low, uint32_t high) { return low | (static_cast<uint64_t>(high) << 32); }
+
+    static uint64_t multiplyHigh(uint64_t, uint64_t);
+
+    uint64_t m_high;
+    uint64_t m_low;
+};
+
+UInt128& UInt128::operator/=(const uint32_t divisor)
+{
+    ASSERT(divisor);
+
+    if (!m_high) {
+        m_low /= divisor;
+        return *this;
+    }
+
+    uint32_t dividend[4];
+    dividend[0] = lowUInt32(m_low);
+    dividend[1] = highUInt32(m_low);
+    dividend[2] = lowUInt32(m_high);
+    dividend[3] = highUInt32(m_high);
+
+    uint32_t quotient[4];
+    uint32_t remainder = 0;
+    for (int i = 3; i >= 0; --i) {
+        const uint64_t work = makeUInt64(dividend[i], remainder);
+        remainder = static_cast<uint32_t>(work % divisor);
+        quotient[i] = static_cast<uint32_t>(work / divisor);
+    }
+    m_low = makeUInt64(quotient[0], quotient[1]);
+    m_high = makeUInt64(quotient[2], quotient[3]);
+    return *this;
+}
+
+// Returns high 64bit of 128bit product.
+uint64_t UInt128::multiplyHigh(uint64_t u, uint64_t v)
+{
+    const uint64_t uLow = lowUInt32(u);
+    const uint64_t uHigh = highUInt32(u);
+    const uint64_t vLow = lowUInt32(v);
+    const uint64_t vHigh = highUInt32(v);
+    const uint64_t partialProduct = uHigh * vLow + highUInt32(uLow * vLow);
+    return uHigh * vHigh + highUInt32(partialProduct) + highUInt32(uLow * vHigh + lowUInt32(partialProduct));
+}
+
+static int countDigits(uint64_t x)
+{
+    int numberOfDigits = 0;
+    for (uint64_t powerOfTen = 1; x >= powerOfTen; powerOfTen *= 10) {
+        ++numberOfDigits;
+        if (powerOfTen >= std::numeric_limits<uint64_t>::max() / 10)
+            break;
+    }
+    return numberOfDigits;
+}
+
+static uint64_t scaleDown(uint64_t x, int n)
+{
+    ASSERT(n >= 0);
+    while (n > 0 && x) {
+        x /= 10;
+        --n;
+    }
+    return x;
+}
+
+static uint64_t scaleUp(uint64_t x, int n)
+{
+    ASSERT(n >= 0);
+    ASSERT(n <= Precision);
+
+    uint64_t y = 1;
+    uint64_t z = 10;
+    for (;;) {
+        if (n & 1)
+            y = y * z;
+
+        n >>= 1;
+        if (!n)
+            return x * y;
+
+        z = z * z;
+    }
+}
+
+} // namespace DecimalPrivate
+
+using namespace DecimalPrivate;
+
+bool Decimal::EncodedData::operator==(const EncodedData& another) const
+{
+    return m_sign == another.m_sign
+        && m_formatClass == another.m_formatClass
+        && m_exponent == another.m_exponent
+        && m_coefficient == another.m_coefficient;
+}
+
+
+Decimal::Decimal(int32_t i32)
+    : Decimal(DecimalLiteral{i32}) {}
+
+Decimal::Decimal(Sign sign, int exponent, uint64_t coefficient)
+    : m_data(sign, coefficient ? exponent : 0, coefficient) {}
+
+Decimal::Decimal(const EncodedData& data)
+    : m_data(data)
+{
+}
+
+Decimal::Decimal(const Decimal& other)
+    : m_data(other.m_data)
+{
+}
+
+Decimal& Decimal::operator=(const Decimal& other)
+{
+    m_data = other.m_data;
+    return *this;
+}
+
+Decimal& Decimal::operator+=(const Decimal& other)
+{
+    m_data = (*this + other).m_data;
+    return *this;
+}
+
+Decimal& Decimal::operator-=(const Decimal& other)
+{
+    m_data = (*this - other).m_data;
+    return *this;
+}
+
+Decimal& Decimal::operator*=(const Decimal& other)
+{
+    m_data = (*this * other).m_data;
+    return *this;
+}
+
+Decimal& Decimal::operator/=(const Decimal& other)
+{
+    m_data = (*this / other).m_data;
+    return *this;
+}
+
+Decimal Decimal::operator-() const
+{
+    if (isNaN())
+        return *this;
+
+    Decimal result(*this);
+    result.m_data.setSign(invertSign(m_data.sign()));
+    return result;
+}
+
+Decimal Decimal::operator+(const Decimal& rhs) const
+{
+    const Decimal& lhs = *this;
+    const Sign lhsSign = lhs.sign();
+    const Sign rhsSign = rhs.sign();
+
+    SpecialValueHandler handler(lhs, rhs);
+    switch (handler.handle()) {
+    case SpecialValueHandler::BothFinite:
+        break;
+
+    case SpecialValueHandler::BothInfinity:
+        return lhsSign == rhsSign ? lhs : nan();
+
+    case SpecialValueHandler::EitherNaN:
+        return handler.value();
+
+    case SpecialValueHandler::LHSIsInfinity:
+        return lhs;
+
+    case SpecialValueHandler::RHSIsInfinity:
+        return rhs;
+    }
+
+    const AlignedOperands alignedOperands = alignOperands(lhs, rhs);
+
+    const uint64_t result = lhsSign == rhsSign
+        ? alignedOperands.lhsCoefficient + alignedOperands.rhsCoefficient
+        : alignedOperands.lhsCoefficient - alignedOperands.rhsCoefficient;
+
+    if (lhsSign == Negative && rhsSign == Positive && !result)
+        return Decimal(Positive, alignedOperands.exponent, 0);
+
+    return static_cast<int64_t>(result) >= 0
+        ? Decimal(lhsSign, alignedOperands.exponent, result)
+        : Decimal(invertSign(lhsSign), alignedOperands.exponent, -static_cast<int64_t>(result));
+}
+
+Decimal Decimal::operator-(const Decimal& rhs) const
+{
+    const Decimal& lhs = *this;
+    const Sign lhsSign = lhs.sign();
+    const Sign rhsSign = rhs.sign();
+
+    SpecialValueHandler handler(lhs, rhs);
+    switch (handler.handle()) {
+    case SpecialValueHandler::BothFinite:
+        break;
+
+    case SpecialValueHandler::BothInfinity:
+        return lhsSign == rhsSign ? nan() : lhs;
+
+    case SpecialValueHandler::EitherNaN:
+        return handler.value();
+
+    case SpecialValueHandler::LHSIsInfinity:
+        return lhs;
+
+    case SpecialValueHandler::RHSIsInfinity:
+        return infinity(invertSign(rhsSign));
+    }
+
+    const AlignedOperands alignedOperands = alignOperands(lhs, rhs);
+
+    const uint64_t result = lhsSign == rhsSign
+        ? alignedOperands.lhsCoefficient - alignedOperands.rhsCoefficient
+        : alignedOperands.lhsCoefficient + alignedOperands.rhsCoefficient;
+
+    if (lhsSign == Negative && rhsSign == Negative && !result)
+        return Decimal(Positive, alignedOperands.exponent, 0);
+
+    return static_cast<int64_t>(result) >= 0
+        ? Decimal(lhsSign, alignedOperands.exponent, result)
+        : Decimal(invertSign(lhsSign), alignedOperands.exponent, -static_cast<int64_t>(result));
+}
+
+Decimal Decimal::operator*(const Decimal& rhs) const
+{
+    const Decimal& lhs = *this;
+    const Sign lhsSign = lhs.sign();
+    const Sign rhsSign = rhs.sign();
+    const Sign resultSign = lhsSign == rhsSign ? Positive : Negative;
+
+    SpecialValueHandler handler(lhs, rhs);
+    switch (handler.handle()) {
+    case SpecialValueHandler::BothFinite: {
+        const uint64_t lhsCoefficient = lhs.m_data.coefficient();
+        const uint64_t rhsCoefficient = rhs.m_data.coefficient();
+        int resultExponent = lhs.exponent() + rhs.exponent();
+        UInt128 work(UInt128::multiply(lhsCoefficient, rhsCoefficient));
+        while (work.high()) {
+            work /= 10;
+            ++resultExponent;
+        }
+        return Decimal(resultSign, resultExponent, work.low());
+    }
+
+    case SpecialValueHandler::BothInfinity:
+        return infinity(resultSign);
+
+    case SpecialValueHandler::EitherNaN:
+        return handler.value();
+
+    case SpecialValueHandler::LHSIsInfinity:
+        return rhs.isZero() ? nan() : infinity(resultSign);
+
+    case SpecialValueHandler::RHSIsInfinity:
+        return lhs.isZero() ? nan() : infinity(resultSign);
+    }
+
+    ASSERT_NOT_REACHED();
+    return nan();
+}
+
+Decimal Decimal::operator/(const Decimal& rhs) const
+{
+    const Decimal& lhs = *this;
+    const Sign lhsSign = lhs.sign();
+    const Sign rhsSign = rhs.sign();
+    const Sign resultSign = lhsSign == rhsSign ? Positive : Negative;
+
+    SpecialValueHandler handler(lhs, rhs);
+    switch (handler.handle()) {
+    case SpecialValueHandler::BothFinite:
+        break;
+
+    case SpecialValueHandler::BothInfinity:
+        return nan();
+
+    case SpecialValueHandler::EitherNaN:
+        return handler.value();
+
+    case SpecialValueHandler::LHSIsInfinity:
+        return infinity(resultSign);
+
+    case SpecialValueHandler::RHSIsInfinity:
+        return zero(resultSign);
+    }
+
+    ASSERT(lhs.isFinite());
+    ASSERT(rhs.isFinite());
+
+    if (rhs.isZero())
+        return lhs.isZero() ? nan() : infinity(resultSign);
+
+    int resultExponent = lhs.exponent() - rhs.exponent();
+
+    if (lhs.isZero())
+        return Decimal(resultSign, resultExponent, 0);
+
+    uint64_t remainder = lhs.m_data.coefficient();
+    const uint64_t divisor = rhs.m_data.coefficient();
+    uint64_t result = 0;
+    for (;;) {
+        while (remainder < divisor && result < MaxCoefficient / 10) {
+            remainder *= 10;
+            result *= 10;
+            --resultExponent;
+        }
+        if (remainder < divisor)
+            break;
+        uint64_t quotient = remainder / divisor;
+        if (result > MaxCoefficient - quotient)
+            break;
+        result += quotient;
+        remainder %= divisor;
+        if (!remainder)
+            break;
+    }
+
+    if (remainder > divisor / 2)
+        ++result;
+
+    return Decimal(resultSign, resultExponent, result);
+}
+
+bool Decimal::operator==(const Decimal& rhs) const
+{
+    if (isNaN() || rhs.isNaN())
+        return false;
+    return m_data == rhs.m_data || compareTo(rhs).isZero();
+}
+
+bool Decimal::operator!=(const Decimal& rhs) const
+{
+    if (isNaN() || rhs.isNaN())
+        return true;
+    if (m_data == rhs.m_data)
+        return false;
+    const Decimal result = compareTo(rhs);
+    if (result.isNaN())
+        return false;
+    return !result.isZero();
+}
+
+bool Decimal::operator<(const Decimal& rhs) const
+{
+    const Decimal result = compareTo(rhs);
+    if (result.isNaN())
+        return false;
+    return !result.isZero() && result.isNegative();
+}
+
+bool Decimal::operator<=(const Decimal& rhs) const
+{
+    if (isNaN() || rhs.isNaN())
+        return false;
+    if (m_data == rhs.m_data)
+        return true;
+    const Decimal result = compareTo(rhs);
+    if (result.isNaN())
+        return false;
+    return result.isZero() || result.isNegative();
+}
+
+bool Decimal::operator>(const Decimal& rhs) const
+{
+    const Decimal result = compareTo(rhs);
+    if (result.isNaN())
+        return false;
+    return !result.isZero() && result.isPositive();
+}
+
+bool Decimal::operator>=(const Decimal& rhs) const
+{
+    if (isNaN() || rhs.isNaN())
+        return false;
+    if (m_data == rhs.m_data)
+        return true;
+    const Decimal result = compareTo(rhs);
+    if (result.isNaN())
+        return false;
+    return result.isZero() || !result.isNegative();
+}
+
+Decimal Decimal::abs() const
+{
+    Decimal result(*this);
+    result.m_data.setSign(Positive);
+    return result;
+}
+
+Decimal::AlignedOperands Decimal::alignOperands(const Decimal& lhs, const Decimal& rhs)
+{
+    ASSERT(lhs.isFinite());
+    ASSERT(rhs.isFinite());
+
+    const int lhsExponent = lhs.exponent();
+    const int rhsExponent = rhs.exponent();
+    int exponent = std::min(lhsExponent, rhsExponent);
+    uint64_t lhsCoefficient = lhs.m_data.coefficient();
+    uint64_t rhsCoefficient = rhs.m_data.coefficient();
+
+    if (lhsExponent > rhsExponent) {
+        const int numberOfLHSDigits = countDigits(lhsCoefficient);
+        if (numberOfLHSDigits) {
+            const int lhsShiftAmount = lhsExponent - rhsExponent;
+            const int overflow = numberOfLHSDigits + lhsShiftAmount - Precision;
+            if (overflow <= 0) {
+                lhsCoefficient = scaleUp(lhsCoefficient, lhsShiftAmount);
+            } else {
+                lhsCoefficient = scaleUp(lhsCoefficient, lhsShiftAmount - overflow);
+                rhsCoefficient = scaleDown(rhsCoefficient, overflow);
+                exponent += overflow;
+            }
+        }
+
+    } else if (lhsExponent < rhsExponent) {
+        const int numberOfRHSDigits = countDigits(rhsCoefficient);
+        if (numberOfRHSDigits) {
+            const int rhsShiftAmount = rhsExponent - lhsExponent;
+            const int overflow = numberOfRHSDigits + rhsShiftAmount - Precision;
+            if (overflow <= 0) {
+                rhsCoefficient = scaleUp(rhsCoefficient, rhsShiftAmount);
+            } else {
+                rhsCoefficient = scaleUp(rhsCoefficient, rhsShiftAmount - overflow);
+                lhsCoefficient = scaleDown(lhsCoefficient, overflow);
+                exponent += overflow;
+            }
+        }
+    }
+
+    AlignedOperands alignedOperands;
+    alignedOperands.exponent = exponent;
+    alignedOperands.lhsCoefficient = lhsCoefficient;
+    alignedOperands.rhsCoefficient = rhsCoefficient;
+    return alignedOperands;
+}
+
+static bool isMultiplePowersOfTen(uint64_t coefficient, int n)
+{
+    return !coefficient || !(coefficient % scaleUp(1, n));
+}
+
+// Round toward positive infinity.
+Decimal Decimal::ceil() const
+{
+    if (isSpecial())
+        return *this;
+
+    if (exponent() >= 0)
+        return *this;
+
+    uint64_t result = m_data.coefficient();
+    const int numberOfDigits = countDigits(result);
+    const int numberOfDropDigits = -exponent();
+    if (numberOfDigits <= numberOfDropDigits)
+        return isPositive() ? Decimal(1) : zero(Positive);
+
+    result = scaleDown(result, numberOfDropDigits);
+    if (isPositive() && !isMultiplePowersOfTen(m_data.coefficient(), numberOfDropDigits))
+        ++result;
+    return Decimal(sign(), 0, result);
+}
+
+Decimal Decimal::compareTo(const Decimal& rhs) const
+{
+    const Decimal result(*this - rhs);
+    switch (result.m_data.formatClass()) {
+    case EncodedData::ClassInfinity:
+        return result.isNegative() ? Decimal(-1) : Decimal(1);
+
+    case EncodedData::ClassNaN:
+    case EncodedData::ClassNormal:
+        return result;
+
+    case EncodedData::ClassZero:
+        return zero(Positive);
+
+    default:
+        ASSERT_NOT_REACHED();
+        return nan();
+    }
+}
+
+// Round toward negative infinity.
+Decimal Decimal::floor() const
+{
+    if (isSpecial())
+        return *this;
+
+    if (exponent() >= 0)
+        return *this;
+
+    uint64_t result = m_data.coefficient();
+    const int numberOfDigits = countDigits(result);
+    const int numberOfDropDigits = -exponent();
+    if (numberOfDigits < numberOfDropDigits)
+        return isPositive() ? zero(Positive) : Decimal(-1);
+
+    result = scaleDown(result, numberOfDropDigits);
+    if (isNegative() && !isMultiplePowersOfTen(m_data.coefficient(), numberOfDropDigits))
+        ++result;
+    return Decimal(sign(), 0, result);
+}
+
+Decimal Decimal::fromDouble(double doubleValue)
+{
+    if (std::isfinite(doubleValue))
+        return fromString(mozToString(doubleValue));
+
+    if (std::isinf(doubleValue))
+        return infinity(doubleValue < 0 ? Negative : Positive);
+
+    return nan();
+}
+
+Decimal Decimal::fromString(const String& str)
+{
+    int exponent = 0;
+    Sign exponentSign = Positive;
+    int numberOfDigits = 0;
+    int numberOfDigitsAfterDot = 0;
+    int numberOfExtraDigits = 0;
+    Sign sign = Positive;
+
+    enum {
+        StateDigit,
+        StateDot,
+        StateDotDigit,
+        StateE,
+        StateEDigit,
+        StateESign,
+        StateSign,
+        StateStart,
+        StateZero,
+    } state = StateStart;
+
+#define HandleCharAndBreak(expected, nextState) \
+    if (ch == expected) { \
+        state = nextState; \
+        break; \
+    }
+
+#define HandleTwoCharsAndBreak(expected1, expected2, nextState) \
+    if (ch == expected1 || ch == expected2) { \
+        state = nextState; \
+        break; \
+    }
+
+    uint64_t accumulator = 0;
+    for (unsigned index = 0; index < str.length(); ++index) {
+        const int ch = str[index];
+        switch (state) {
+        case StateDigit:
+            if (ch >= '0' && ch <= '9') {
+                if (numberOfDigits < Precision) {
+                    ++numberOfDigits;
+                    accumulator *= 10;
+                    accumulator += ch - '0';
+                } else {
+                    ++numberOfExtraDigits;
+                }
+                break;
+            }
+
+            HandleCharAndBreak('.', StateDot);
+            HandleTwoCharsAndBreak('E', 'e', StateE);
+            return nan();
+
+        case StateDot:
+        case StateDotDigit:
+            if (ch >= '0' && ch <= '9') {
+                if (numberOfDigits < Precision) {
+                    ++numberOfDigits;
+                    ++numberOfDigitsAfterDot;
+                    accumulator *= 10;
+                    accumulator += ch - '0';
+                }
+                state = StateDotDigit;
+                break;
+            }
+
+            HandleTwoCharsAndBreak('E', 'e', StateE);
+            return nan();
+
+        case StateE:
+            if (ch == '+') {
+                exponentSign = Positive;
+                state = StateESign;
+                break;
+            }
+
+            if (ch == '-') {
+                exponentSign = Negative;
+                state = StateESign;
+                break;
+            }
+
+            if (ch >= '0' && ch <= '9') {
+                exponent = ch - '0';
+                state = StateEDigit;
+                break;
+            }
+
+            return nan();
+
+        case StateEDigit:
+            if (ch >= '0' && ch <= '9') {
+                exponent *= 10;
+                exponent += ch - '0';
+                if (exponent > ExponentMax + Precision) {
+                    if (accumulator)
+                        return exponentSign == Negative ? zero(Positive) : infinity(sign);
+                    return zero(sign);
+                }
+                state = StateEDigit;
+                break;
+            }
+
+            return nan();
+
+        case StateESign:
+            if (ch >= '0' && ch <= '9') {
+                exponent = ch - '0';
+                state = StateEDigit;
+                break;
+            }
+
+            return nan();
+
+        case StateSign:
+            if (ch >= '1' && ch <= '9') {
+                accumulator = ch - '0';
+                numberOfDigits = 1;
+                state = StateDigit;
+                break;
+            }
+
+            HandleCharAndBreak('0', StateZero);
+            return nan();
+
+        case StateStart:
+            if (ch >= '1' && ch <= '9') {
+                accumulator = ch - '0';
+                numberOfDigits = 1;
+                state = StateDigit;
+                break;
+            }
+
+            if (ch == '-') {
+                sign = Negative;
+                state = StateSign;
+                break;
+            }
+
+            if (ch == '+') {
+                sign = Positive;
+                state = StateSign;
+                break;
+            }
+
+            HandleCharAndBreak('0', StateZero);
+            HandleCharAndBreak('.', StateDot);
+            return nan();
+
+        case StateZero:
+            if (ch == '0')
+                break;
+
+            if (ch >= '1' && ch <= '9') {
+                accumulator = ch - '0';
+                numberOfDigits = 1;
+                state = StateDigit;
+                break;
+            }
+
+            HandleCharAndBreak('.', StateDot);
+            HandleTwoCharsAndBreak('E', 'e', StateE);
+            return nan();
+
+        default:
+            ASSERT_NOT_REACHED();
+            return nan();
+        }
+    }
+
+    if (state == StateZero)
+        return zero(sign);
+
+    if (state == StateDigit || state == StateEDigit || state == StateDotDigit) {
+        int resultExponent = exponent * (exponentSign == Negative ? -1 : 1) - numberOfDigitsAfterDot + numberOfExtraDigits;
+        if (resultExponent < ExponentMin)
+            return zero(Positive);
+
+        const int overflow = resultExponent - ExponentMax + 1;
+        if (overflow > 0) {
+            if (overflow + numberOfDigits - numberOfDigitsAfterDot > Precision)
+                return infinity(sign);
+            accumulator = scaleUp(accumulator, overflow);
+            resultExponent -= overflow;
+        }
+
+        return Decimal(sign, resultExponent, accumulator);
+    }
+
+    return nan();
+}
+
+Decimal Decimal::infinity(const Sign sign)
+{
+    return Decimal(EncodedData(sign, EncodedData::ClassInfinity));
+}
+
+Decimal Decimal::nan()
+{
+    return Decimal(EncodedData(Positive, EncodedData::ClassNaN));
+}
+
+Decimal Decimal::remainder(const Decimal& rhs) const
+{
+    const Decimal quotient = *this / rhs;
+    return quotient.isSpecial() ? quotient : *this - (quotient.isNegative() ? quotient.ceil() : quotient.floor()) * rhs;
+}
+
+Decimal Decimal::round() const
+{
+    if (isSpecial())
+        return *this;
+
+    if (exponent() >= 0)
+        return *this;
+
+    uint64_t result = m_data.coefficient();
+    const int numberOfDigits = countDigits(result);
+    const int numberOfDropDigits = -exponent();
+    if (numberOfDigits < numberOfDropDigits)
+        return zero(Positive);
+
+    result = scaleDown(result, numberOfDropDigits - 1);
+    if (result % 10 >= 5)
+        result += 10;
+    result /= 10;
+    return Decimal(sign(), 0, result);
+}
+
+double Decimal::toDouble() const
+{
+    if (isFinite()) {
+        bool valid;
+        const double doubleValue = mozToDouble(toString(), &valid);
+        return valid ? doubleValue : std::numeric_limits<double>::quiet_NaN();
+    }
+
+    if (isInfinity())
+        return isNegative() ? -std::numeric_limits<double>::infinity() : std::numeric_limits<double>::infinity();
+
+    return std::numeric_limits<double>::quiet_NaN();
+}
+
+String Decimal::toString() const
+{
+    switch (m_data.formatClass()) {
+    case EncodedData::ClassInfinity:
+        return sign() ? "-Infinity" : "Infinity";
+
+    case EncodedData::ClassNaN:
+        return "NaN";
+
+    case EncodedData::ClassNormal:
+    case EncodedData::ClassZero:
+        break;
+
+    default:
+        ASSERT_NOT_REACHED();
+        return "";
+    }
+
+    StringBuilder builder;
+    if (sign())
+        builder.append('-');
+
+    int originalExponent = exponent();
+    uint64_t coefficient = m_data.coefficient();
+
+    if (originalExponent < 0) {
+        const int maxDigits = DBL_DIG;
+        uint64_t lastDigit = 0;
+        while (countDigits(coefficient) > maxDigits) {
+            lastDigit = coefficient % 10;
+            coefficient /= 10;
+            ++originalExponent;
+        }
+
+        if (lastDigit >= 5)
+            ++coefficient;
+
+        while (originalExponent < 0 && coefficient && !(coefficient % 10)) {
+            coefficient /= 10;
+            ++originalExponent;
+        }
+    }
+
+    const String digits = mozToString(coefficient);
+    int coefficientLength = static_cast<int>(digits.length());
+    const int adjustedExponent = originalExponent + coefficientLength - 1;
+    if (originalExponent <= 0 && adjustedExponent >= -6) {
+        if (!originalExponent) {
+            builder.append(digits);
+            return builder.toString();
+        }
+
+        if (adjustedExponent >= 0) {
+            for (int i = 0; i < coefficientLength; ++i) {
+                builder.append(digits[i]);
+                if (i == adjustedExponent)
+                    builder.append('.');
+            }
+            return builder.toString();
+        }
+
+        builder.appendLiteral("0.");
+        for (int i = adjustedExponent + 1; i < 0; ++i)
+            builder.append('0');
+
+        builder.append(digits);
+
+    } else {
+        builder.append(digits[0]);
+        while (coefficientLength >= 2 && digits[coefficientLength - 1] == '0')
+            --coefficientLength;
+        if (coefficientLength >= 2) {
+            builder.append('.');
+            for (int i = 1; i < coefficientLength; ++i)
+                builder.append(digits[i]);
+        }
+
+        if (adjustedExponent) {
+            builder.append(adjustedExponent < 0 ? "e" : "e+");
+            builder.appendNumber(adjustedExponent);
+        }
+    }
+    return builder.toString();
+}
+
+bool Decimal::toString(char* strBuf, size_t bufLength) const
+{
+  ASSERT(bufLength > 0);
+  String str = toString();
+  size_t length = str.copy(strBuf, bufLength);
+  if (length < bufLength) {
+    strBuf[length] = '\0';
+    return true;
+  }
+  strBuf[bufLength - 1] = '\0';
+  return false;
+}
+
+Decimal Decimal::zero(Sign sign)
+{
+    return Decimal(EncodedData(sign, EncodedData::ClassZero));
+}
+
+} // namespace blink
+
+// Implementation of DoubleConversion.h:
+
+namespace mozilla {
+
+Maybe<double> StringToDouble(Span<const char> aStringSpan) {
+    bool valid = false;
+    double result = mozToDouble(aStringSpan, &valid);
+    return valid ? Some(result) : Nothing();
+}
+
+}
diff --git a/mozglue/misc/decimal/Decimal.h b/mozglue/misc/decimal/Decimal.h
new file mode 100644
index 0000000000..4bb9a841e5
--- /dev/null
+++ b/mozglue/misc/decimal/Decimal.h
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * Imported from:
+ * https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/platform/Decimal.h
+ * Check UPSTREAM-GIT-SHA for the commit ID of the last update from Blink core.
+ */
+
+#ifndef Decimal_h
+#define Decimal_h
+
+#include "mozilla/Assertions.h"
+#include <stdint.h>
+#include "mozilla/Types.h"
+
+#include <string>
+
+#ifndef ASSERT
+#define DEFINED_ASSERT_FOR_DECIMAL_H 1
+#define ASSERT MOZ_ASSERT
+#endif
+
+#define PLATFORM_EXPORT
+
+// To use USING_FAST_MALLOC we'd need:
+// https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/wtf/Allocator.h
+// Since we don't allocate Decimal objects, no need.
+#define USING_FAST_MALLOC(type) \
+  void ignore_this_dummy_method() = delete
+
+#define DISALLOW_NEW()                                          \
+    private:                                                    \
+        void* operator new(size_t) = delete;                    \
+        void* operator new(size_t, void*) = delete;             \
+    public:
+
+namespace blink {
+
+namespace DecimalPrivate {
+constexpr int ExponentMax = 1023;
+constexpr int ExponentMin = -1023;
+constexpr int Precision = 18;
+
+static const uint64_t MaxCoefficient = UINT64_C(0xDE0B6B3A763FFFF);  // 999999999999999999 == 18 9's
+class SpecialValueHandler;
+}
+
+struct DecimalLiteral {
+  int32_t value;
+  friend constexpr DecimalLiteral operator*(int32_t lhs, DecimalLiteral rhs) {
+    return {lhs * rhs.value};
+  }
+  constexpr DecimalLiteral operator-() {
+    return {-value};
+  }
+};
+
+constexpr DecimalLiteral operator""_d(unsigned long long value) {
+  return {static_cast<int32_t>(value)};
+}
+
+// This class represents decimal base floating point number.
+//
+// FIXME: Once all C++ compiler support decimal type, we should replace this
+// class to compiler supported one. See below URI for current status of decimal
+// type for C++: // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1977.html
+class PLATFORM_EXPORT Decimal {
+    USING_FAST_MALLOC(Decimal);
+public:
+    enum Sign {
+        Positive,
+        Negative,
+    };
+
+    // You should not use EncodedData other than unit testing.
+    class EncodedData {
+        DISALLOW_NEW();
+        // For accessing FormatClass.
+        friend class Decimal;
+        friend class DecimalPrivate::SpecialValueHandler;
+    public:
+     constexpr EncodedData(Sign sign, int exponent, uint64_t coefficient)
+         : m_coefficient(0),
+           m_exponent(0),
+           m_formatClass(coefficient ? ClassNormal : ClassZero),
+           m_sign(sign) {
+       if (exponent >= DecimalPrivate::ExponentMin &&
+           exponent <= DecimalPrivate::ExponentMax) {
+         while (coefficient > DecimalPrivate::MaxCoefficient) {
+           coefficient /= 10;
+           ++exponent;
+         }
+       }
+
+       if (exponent > DecimalPrivate::ExponentMax) {
+         m_formatClass = ClassInfinity;
+         return;
+       }
+
+       if (exponent < DecimalPrivate::ExponentMin) {
+         m_formatClass = ClassZero;
+         return;
+       }
+
+       m_coefficient = coefficient;
+       m_exponent = static_cast<int16_t>(exponent);
+     }
+
+        bool operator==(const EncodedData&) const;
+        bool operator!=(const EncodedData& another) const { return !operator==(another); }
+
+        uint64_t coefficient() const { return m_coefficient; }
+        int countDigits() const;
+        int exponent() const { return m_exponent; }
+        bool isFinite() const { return !isSpecial(); }
+        bool isInfinity() const { return m_formatClass == ClassInfinity; }
+        bool isNaN() const { return m_formatClass == ClassNaN; }
+        bool isSpecial() const { return m_formatClass == ClassInfinity || m_formatClass == ClassNaN; }
+        bool isZero() const { return m_formatClass == ClassZero; }
+        Sign sign() const { return m_sign; }
+        void setSign(Sign sign) { m_sign = sign; }
+
+    private:
+        enum FormatClass {
+            ClassInfinity,
+            ClassNormal,
+            ClassNaN,
+            ClassZero,
+        };
+
+        constexpr EncodedData(Sign sign, FormatClass formatClass)
+            : m_coefficient(0),
+              m_exponent(0),
+              m_formatClass(formatClass),
+              m_sign(sign) {}
+
+        FormatClass formatClass() const { return m_formatClass; }
+
+        uint64_t m_coefficient;
+        int16_t m_exponent;
+        FormatClass m_formatClass;
+        Sign m_sign;
+    };
+
+    constexpr explicit Decimal(DecimalLiteral i32)
+    : m_data(i32.value < 0 ? Negative : Positive, 0,
+             i32.value < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32.value))
+                     : static_cast<uint64_t>(i32.value)) {}
+
+    MFBT_API explicit Decimal(int32_t i32 = 0);
+    MFBT_API Decimal(Sign sign, int exponent, uint64_t coefficient);
+    MFBT_API Decimal(const Decimal&);
+
+    MFBT_API Decimal& operator=(const Decimal&);
+    MFBT_API Decimal& operator+=(const Decimal&);
+    MFBT_API Decimal& operator-=(const Decimal&);
+    MFBT_API Decimal& operator*=(const Decimal&);
+    MFBT_API Decimal& operator/=(const Decimal&);
+
+    MFBT_API Decimal operator-() const;
+
+    MFBT_API bool operator==(const Decimal&) const;
+    MFBT_API bool operator!=(const Decimal&) const;
+    MFBT_API bool operator<(const Decimal&) const;
+    MFBT_API bool operator<=(const Decimal&) const;
+    MFBT_API bool operator>(const Decimal&) const;
+    MFBT_API bool operator>=(const Decimal&) const;
+
+    MFBT_API Decimal operator+(const Decimal&) const;
+    MFBT_API Decimal operator-(const Decimal&) const;
+    MFBT_API Decimal operator*(const Decimal&) const;
+    MFBT_API Decimal operator/(const Decimal&) const;
+
+    int exponent() const
+    {
+        ASSERT(isFinite());
+        return m_data.exponent();
+    }
+
+    bool isFinite() const { return m_data.isFinite(); }
+    bool isInfinity() const { return m_data.isInfinity(); }
+    bool isNaN() const { return m_data.isNaN(); }
+    bool isNegative() const { return sign() == Negative; }
+    bool isPositive() const { return sign() == Positive; }
+    bool isSpecial() const { return m_data.isSpecial(); }
+    bool isZero() const { return m_data.isZero(); }
+
+    MFBT_API Decimal abs() const;
+    MFBT_API Decimal ceil() const;
+    MFBT_API Decimal floor() const;
+    MFBT_API Decimal remainder(const Decimal&) const;
+    MFBT_API Decimal round() const;
+
+    MFBT_API double toDouble() const;
+    // Note: toString method supports infinity and nan but fromString not.
+    MFBT_API std::string toString() const;
+    MFBT_API bool toString(char* strBuf, size_t bufLength) const;
+
+    static MFBT_API Decimal fromDouble(double);
+    // fromString supports following syntax EBNF:
+    //  number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)?
+    //          | sign? '.' digit+ (exponent-marker sign? digit+)?
+    //  sign ::= '+' | '-'
+    //  exponent-marker ::= 'e' | 'E'
+    //  digit ::= '0' | '1' | ... | '9'
+    // Note: fromString doesn't support "infinity" and "nan".
+    static MFBT_API Decimal fromString(const std::string& aValue);
+    static MFBT_API Decimal infinity(Sign);
+    static MFBT_API Decimal nan();
+    static MFBT_API Decimal zero(Sign);
+
+    // You should not use below methods. We expose them for unit testing.
+    MFBT_API explicit Decimal(const EncodedData&);
+    const EncodedData& value() const { return m_data; }
+
+private:
+    struct AlignedOperands {
+        uint64_t lhsCoefficient;
+        uint64_t rhsCoefficient;
+        int exponent;
+    };
+
+    MFBT_API explicit Decimal(double);
+    MFBT_API Decimal compareTo(const Decimal&) const;
+
+    static MFBT_API AlignedOperands alignOperands(const Decimal& lhs, const Decimal& rhs);
+    static inline Sign invertSign(Sign sign) { return sign == Negative ? Positive : Negative; }
+
+    Sign sign() const { return m_data.sign(); }
+
+    EncodedData m_data;
+};
+
+} // namespace blink
+
+namespace mozilla {
+typedef blink::Decimal Decimal;
+using blink::operator""_d;
+} // namespace mozilla
+
+#undef USING_FAST_MALLOC
+
+#ifdef DEFINED_ASSERT_FOR_DECIMAL_H
+#undef DEFINED_ASSERT_FOR_DECIMAL_H
+#undef ASSERT
+#endif
+
+#endif // Decimal_h
diff --git a/mozglue/misc/decimal/DoubleConversion.h b/mozglue/misc/decimal/DoubleConversion.h
new file mode 100644
index 0000000000..14c19e2540
--- /dev/null
+++ b/mozglue/misc/decimal/DoubleConversion.h
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/* A utility function that converts a string to a double independent of OS locale. */
+
+#ifndef MOZILLA_DOUBLECONVERSION_H
+#define MOZILLA_DOUBLECONVERSION_H
+
+#include "mozilla/Maybe.h"
+#include "mozilla/Span.h"
+
+#include <string>
+
+namespace mozilla {
+
+// Parses aStringSpan into a double floating point value. Always treats . as the
+// decimal separator, regardless of OS locale. Consumes the entire string;
+// trailing garbage is invalid. Returns Nothing() for invalid input.
+// The implementation uses double_conversion::StringToDoubleConverter with
+// NO_FLAGS, see double-conversion/string-to-double.h for more documentation.
+Maybe<double> StringToDouble(Span<const char> aStringSpan);
+
+}
+
+#endif // MOZILLA_DOUBLECONVERSION_H
diff --git a/mozglue/misc/decimal/UPSTREAM-GIT-SHA b/mozglue/misc/decimal/UPSTREAM-GIT-SHA
new file mode 100644
index 0000000000..ed86150b28
--- /dev/null
+++ b/mozglue/misc/decimal/UPSTREAM-GIT-SHA
@@ -0,0 +1 @@
+cad4c9e3b3c9e80bb189059373db528272bca96f
diff --git a/mozglue/misc/decimal/add-doubleconversion-impl.patch b/mozglue/misc/decimal/add-doubleconversion-impl.patch
new file mode 100644
index 0000000000..1cf0fb6ff1
--- /dev/null
+++ b/mozglue/misc/decimal/add-doubleconversion-impl.patch
@@ -0,0 +1,42 @@
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -25,16 +25,17 @@
+  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  */
+ 
+ #include "Decimal.h"
+ #include "moz-decimal-utils.h"
++#include "DoubleConversion.h"
+ 
+ using namespace moz_decimal_utils;
+ 
+ #include <algorithm>
+ #include <float.h>
+ 
+ namespace blink {
+ 
+@@ -1043,8 +1044,20 @@ bool Decimal::toString(char* strBuf, siz
+ }
+ 
+ Decimal Decimal::zero(Sign sign)
+ {
+     return Decimal(EncodedData(sign, EncodedData::ClassZero));
+ }
+ 
+ } // namespace blink
++
++// Implementation of DoubleConversion.h:
++
++namespace mozilla {
++
++Maybe<double> StringToDouble(Span<const char> aStringSpan) {
++    bool valid = false;
++    double result = mozToDouble(aStringSpan, &valid);
++    return valid ? Some(result) : Nothing();
++}
++
++}
diff --git a/mozglue/misc/decimal/comparison-with-nan.patch b/mozglue/misc/decimal/comparison-with-nan.patch
new file mode 100644
index 0000000000..0e274ce033
--- /dev/null
+++ b/mozglue/misc/decimal/comparison-with-nan.patch
@@ -0,0 +1,67 @@
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -509,21 +509,25 @@ Decimal Decimal::operator/(const Decimal
+     if (remainder > divisor / 2)
+         ++result;
+ 
+     return Decimal(resultSign, resultExponent, result);
+ }
+ 
+ bool Decimal::operator==(const Decimal& rhs) const
+ {
++    if (isNaN() || rhs.isNaN())
++        return false;
+     return m_data == rhs.m_data || compareTo(rhs).isZero();
+ }
+ 
+ bool Decimal::operator!=(const Decimal& rhs) const
+ {
++    if (isNaN() || rhs.isNaN())
++        return true;
+     if (m_data == rhs.m_data)
+         return false;
+     const Decimal result = compareTo(rhs);
+     if (result.isNaN())
+         return false;
+     return !result.isZero();
+ }
+ 
+@@ -532,16 +536,18 @@ bool Decimal::operator<(const Decimal& r
+     const Decimal result = compareTo(rhs);
+     if (result.isNaN())
+         return false;
+     return !result.isZero() && result.isNegative();
+ }
+ 
+ bool Decimal::operator<=(const Decimal& rhs) const
+ {
++    if (isNaN() || rhs.isNaN())
++        return false;
+     if (m_data == rhs.m_data)
+         return true;
+     const Decimal result = compareTo(rhs);
+     if (result.isNaN())
+         return false;
+     return result.isZero() || result.isNegative();
+ }
+ 
+@@ -550,16 +556,18 @@ bool Decimal::operator>(const Decimal& r
+     const Decimal result = compareTo(rhs);
+     if (result.isNaN())
+         return false;
+     return !result.isZero() && result.isPositive();
+ }
+ 
+ bool Decimal::operator>=(const Decimal& rhs) const
+ {
++    if (isNaN() || rhs.isNaN())
++        return false;
+     if (m_data == rhs.m_data)
+         return true;
+     const Decimal result = compareTo(rhs);
+     if (result.isNaN())
+         return false;
+     return result.isZero() || !result.isNegative();
+ }
+ 
diff --git a/mozglue/misc/decimal/fix-wshadow-warnings.patch b/mozglue/misc/decimal/fix-wshadow-warnings.patch
new file mode 100644
index 0000000000..465c61a223
--- /dev/null
+++ b/mozglue/misc/decimal/fix-wshadow-warnings.patch
@@ -0,0 +1,171 @@
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -118,18 +118,18 @@ Decimal SpecialValueHandler::value() con
+         ASSERT_NOT_REACHED();
+         return m_lhs;
+     }
+ }
+ 
+ // This class is used for 128 bit unsigned integer arithmetic.
+ class UInt128 {
+ public:
+-    UInt128(uint64_t low, uint64_t high)
+-        : m_high(high), m_low(low)
++    UInt128(uint64_t aLow, uint64_t aHigh)
++        : m_high(aHigh), m_low(aLow)
+     {
+     }
+ 
+     UInt128& operator/=(uint32_t);
+ 
+     uint64_t high() const { return m_high; }
+     uint64_t low() const { return m_low; }
+ 
+@@ -224,68 +224,68 @@ static uint64_t scaleUp(uint64_t x, int 
+         z = z * z;
+     }
+ }
+ 
+ } // namespace DecimalPrivate
+ 
+ using namespace DecimalPrivate;
+ 
+-Decimal::EncodedData::EncodedData(Sign sign, FormatClass formatClass)
++Decimal::EncodedData::EncodedData(Sign aSign, FormatClass aFormatClass)
+     : m_coefficient(0)
+     , m_exponent(0)
+-    , m_formatClass(formatClass)
+-    , m_sign(sign)
++    , m_formatClass(aFormatClass)
++    , m_sign(aSign)
+ {
+ }
+ 
+-Decimal::EncodedData::EncodedData(Sign sign, int exponent, uint64_t coefficient)
+-    : m_formatClass(coefficient ? ClassNormal : ClassZero)
+-    , m_sign(sign)
++Decimal::EncodedData::EncodedData(Sign aSign, int aExponent, uint64_t aCoefficient)
++    : m_formatClass(aCoefficient ? ClassNormal : ClassZero)
++    , m_sign(aSign)
+ {
+-    if (exponent >= ExponentMin && exponent <= ExponentMax) {
+-        while (coefficient > MaxCoefficient) {
+-            coefficient /= 10;
+-            ++exponent;
++    if (aExponent >= ExponentMin && aExponent <= ExponentMax) {
++        while (aCoefficient > MaxCoefficient) {
++            aCoefficient /= 10;
++            ++aExponent;
+         }
+     }
+ 
+-    if (exponent > ExponentMax) {
++    if (aExponent > ExponentMax) {
+         m_coefficient = 0;
+         m_exponent = 0;
+         m_formatClass = ClassInfinity;
+         return;
+     }
+ 
+-    if (exponent < ExponentMin) {
++    if (aExponent < ExponentMin) {
+         m_coefficient = 0;
+         m_exponent = 0;
+         m_formatClass = ClassZero;
+         return;
+     }
+ 
+-    m_coefficient = coefficient;
+-    m_exponent = static_cast<int16_t>(exponent);
++    m_coefficient = aCoefficient;
++    m_exponent = static_cast<int16_t>(aExponent);
+ }
+ 
+ bool Decimal::EncodedData::operator==(const EncodedData& another) const
+ {
+     return m_sign == another.m_sign
+         && m_formatClass == another.m_formatClass
+         && m_exponent == another.m_exponent
+         && m_coefficient == another.m_coefficient;
+ }
+ 
+ Decimal::Decimal(int32_t i32)
+     : m_data(i32 < 0 ? Negative : Positive, 0, i32 < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32)) : static_cast<uint64_t>(i32))
+ {
+ }
+ 
+-Decimal::Decimal(Sign sign, int exponent, uint64_t coefficient)
+-    : m_data(sign, coefficient ? exponent : 0, coefficient)
++Decimal::Decimal(Sign aSign, int aExponent, uint64_t aCoefficient)
++    : m_data(aSign, aCoefficient ? aExponent : 0, aCoefficient)
+ {
+ }
+ 
+ Decimal::Decimal(const EncodedData& data)
+     : m_data(data)
+ {
+ }
+ 
+@@ -479,32 +479,32 @@ Decimal Decimal::operator/(const Decimal
+     if (rhs.isZero())
+         return lhs.isZero() ? nan() : infinity(resultSign);
+ 
+     int resultExponent = lhs.exponent() - rhs.exponent();
+ 
+     if (lhs.isZero())
+         return Decimal(resultSign, resultExponent, 0);
+ 
+-    uint64_t remainder = lhs.m_data.coefficient();
++    uint64_t lhsRemainder = lhs.m_data.coefficient();
+     const uint64_t divisor = rhs.m_data.coefficient();
+     uint64_t result = 0;
+     while (result < MaxCoefficient / 100) {
+-        while (remainder < divisor) {
+-            remainder *= 10;
++        while (lhsRemainder < divisor) {
++            lhsRemainder *= 10;
+             result *= 10;
+             --resultExponent;
+         }
+-        result += remainder / divisor;
+-        remainder %= divisor;
+-        if (!remainder)
++        result += lhsRemainder / divisor;
++        lhsRemainder %= divisor;
++        if (!lhsRemainder)
+             break;
+     }
+ 
+-    if (remainder > divisor / 2)
++    if (lhsRemainder > divisor / 2)
+         ++result;
+ 
+     return Decimal(resultSign, resultExponent, result);
+ }
+ 
+ bool Decimal::operator==(const Decimal& rhs) const
+ {
+     if (isNaN() || rhs.isNaN())
+diff --git a/mozglue/misc/decimal/Decimal.h b/mozglue/misc/decimal/Decimal.h
+--- a/mozglue/misc/decimal/Decimal.h
++++ b/mozglue/misc/decimal/Decimal.h
+@@ -88,17 +88,17 @@ public:
+         int countDigits() const;
+         int exponent() const { return m_exponent; }
+         bool isFinite() const { return !isSpecial(); }
+         bool isInfinity() const { return m_formatClass == ClassInfinity; }
+         bool isNaN() const { return m_formatClass == ClassNaN; }
+         bool isSpecial() const { return m_formatClass == ClassInfinity || m_formatClass == ClassNaN; }
+         bool isZero() const { return m_formatClass == ClassZero; }
+         Sign sign() const { return m_sign; }
+-        void setSign(Sign sign) { m_sign = sign; }
++        void setSign(Sign aSign) { m_sign = aSign; }
+ 
+     private:
+         enum FormatClass {
+             ClassInfinity,
+             ClassNormal,
+             ClassNaN,
+             ClassZero,
+         };
diff --git a/mozglue/misc/decimal/mfbt-abi-markers.patch b/mozglue/misc/decimal/mfbt-abi-markers.patch
new file mode 100644
index 0000000000..1d50d3d643
--- /dev/null
+++ b/mozglue/misc/decimal/mfbt-abi-markers.patch
@@ -0,0 +1,150 @@
+diff --git a/mozglue/misc/decimal/Decimal.h b/mozglue/misc/decimal/Decimal.h
+--- a/mozglue/misc/decimal/Decimal.h
++++ b/mozglue/misc/decimal/Decimal.h
+@@ -26,16 +26,18 @@
+  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  */
+ 
+ #ifndef Decimal_h
+ #define Decimal_h
+ 
++#include "mozilla/Types.h"
++
+ #include "platform/PlatformExport.h"
+ #include "wtf/Allocator.h"
+ #include "wtf/Assertions.h"
+ #include "wtf/text/WTFString.h"
+ #include <stdint.h>
+ 
+ namespace blink {
+ 
+@@ -91,92 +93,92 @@ public:
+         FormatClass formatClass() const { return m_formatClass; }
+ 
+         uint64_t m_coefficient;
+         int16_t m_exponent;
+         FormatClass m_formatClass;
+         Sign m_sign;
+     };
+ 
+-    Decimal(int32_t = 0);
+-    Decimal(Sign, int exponent, uint64_t coefficient);
+-    Decimal(const Decimal&);
++    MFBT_API explicit Decimal(int32_t = 0);
++    MFBT_API Decimal(Sign, int exponent, uint64_t coefficient);
++    MFBT_API Decimal(const Decimal&);
+ 
+-    Decimal& operator=(const Decimal&);
+-    Decimal& operator+=(const Decimal&);
+-    Decimal& operator-=(const Decimal&);
+-    Decimal& operator*=(const Decimal&);
+-    Decimal& operator/=(const Decimal&);
++    MFBT_API Decimal& operator=(const Decimal&);
++    MFBT_API Decimal& operator+=(const Decimal&);
++    MFBT_API Decimal& operator-=(const Decimal&);
++    MFBT_API Decimal& operator*=(const Decimal&);
++    MFBT_API Decimal& operator/=(const Decimal&);
+ 
+-    Decimal operator-() const;
++    MFBT_API Decimal operator-() const;
+ 
+-    bool operator==(const Decimal&) const;
+-    bool operator!=(const Decimal&) const;
+-    bool operator<(const Decimal&) const;
+-    bool operator<=(const Decimal&) const;
+-    bool operator>(const Decimal&) const;
+-    bool operator>=(const Decimal&) const;
++    MFBT_API bool operator==(const Decimal&) const;
++    MFBT_API bool operator!=(const Decimal&) const;
++    MFBT_API bool operator<(const Decimal&) const;
++    MFBT_API bool operator<=(const Decimal&) const;
++    MFBT_API bool operator>(const Decimal&) const;
++    MFBT_API bool operator>=(const Decimal&) const;
+ 
+-    Decimal operator+(const Decimal&) const;
+-    Decimal operator-(const Decimal&) const;
+-    Decimal operator*(const Decimal&) const;
+-    Decimal operator/(const Decimal&) const;
++    MFBT_API Decimal operator+(const Decimal&) const;
++    MFBT_API Decimal operator-(const Decimal&) const;
++    MFBT_API Decimal operator*(const Decimal&) const;
++    MFBT_API Decimal operator/(const Decimal&) const;
+ 
+     int exponent() const
+     {
+         ASSERT(isFinite());
+         return m_data.exponent();
+     }
+ 
+     bool isFinite() const { return m_data.isFinite(); }
+     bool isInfinity() const { return m_data.isInfinity(); }
+     bool isNaN() const { return m_data.isNaN(); }
+     bool isNegative() const { return sign() == Negative; }
+     bool isPositive() const { return sign() == Positive; }
+     bool isSpecial() const { return m_data.isSpecial(); }
+     bool isZero() const { return m_data.isZero(); }
+ 
+-    Decimal abs() const;
+-    Decimal ceil() const;
+-    Decimal floor() const;
+-    Decimal remainder(const Decimal&) const;
+-    Decimal round() const;
++    MFBT_API Decimal abs() const;
++    MFBT_API Decimal ceil() const;
++    MFBT_API Decimal floor() const;
++    MFBT_API Decimal remainder(const Decimal&) const;
++    MFBT_API Decimal round() const;
+ 
+-    double toDouble() const;
++    MFBT_API double toDouble() const;
+     // Note: toString method supports infinity and nan but fromString not.
+-    String toString() const;
++    MFBT_API String toString() const;
+ 
+-    static Decimal fromDouble(double);
++    static MFBT_API Decimal fromDouble(double);
+     // fromString supports following syntax EBNF:
+     //  number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)?
+     //          | sign? '.' digit+ (exponent-marker sign? digit+)?
+     //  sign ::= '+' | '-'
+     //  exponent-marker ::= 'e' | 'E'
+     //  digit ::= '0' | '1' | ... | '9'
+     // Note: fromString doesn't support "infinity" and "nan".
+-    static Decimal fromString(const String&);
+-    static Decimal infinity(Sign);
+-    static Decimal nan();
+-    static Decimal zero(Sign);
++    static MFBT_API Decimal fromString(const String&);
++    static MFBT_API Decimal infinity(Sign);
++    static MFBT_API Decimal nan();
++    static MFBT_API Decimal zero(Sign);
+ 
+     // You should not use below methods. We expose them for unit testing.
+-    explicit Decimal(const EncodedData&);
++    MFBT_API explicit Decimal(const EncodedData&);
+     const EncodedData& value() const { return m_data; }
+ 
+ private:
+     struct AlignedOperands {
+         uint64_t lhsCoefficient;
+         uint64_t rhsCoefficient;
+         int exponent;
+     };
+ 
+-    Decimal(double);
+-    Decimal compareTo(const Decimal&) const;
++    MFBT_API explicit Decimal(double);
++    MFBT_API Decimal compareTo(const Decimal&) const;
+ 
+-    static AlignedOperands alignOperands(const Decimal& lhs, const Decimal& rhs);
++    static MFBT_API AlignedOperands alignOperands(const Decimal& lhs, const Decimal& rhs);
+     static inline Sign invertSign(Sign sign) { return sign == Negative ? Positive : Negative; }
+ 
+     Sign sign() const { return m_data.sign(); }
+ 
+     EncodedData m_data;
+ };
+ 
+ } // namespace blink
diff --git a/mozglue/misc/decimal/moz-constexpr-decimal.patch b/mozglue/misc/decimal/moz-constexpr-decimal.patch
new file mode 100644
index 0000000000..845352bd05
--- /dev/null
+++ b/mozglue/misc/decimal/moz-constexpr-decimal.patch
@@ -0,0 +1,218 @@
+diff --git a/dom/html/HTMLInputElement.cpp b/dom/html/HTMLInputElement.cpp
+index 7fdf38c5cb7c3..8bce5c3312f55 100644
+--- a/dom/html/HTMLInputElement.cpp
++++ b/dom/html/HTMLInputElement.cpp
+@@ -187,16 +187,18 @@ static const nsAttrValue::EnumTable kCaptureTable[] = {
+ 
+ static const nsAttrValue::EnumTable* kCaptureDefault = &kCaptureTable[2];
+ 
+-const Decimal HTMLInputElement::kStepScaleFactorDate = Decimal(86400000);
+-const Decimal HTMLInputElement::kStepScaleFactorNumberRange = Decimal(1);
+-const Decimal HTMLInputElement::kStepScaleFactorTime = Decimal(1000);
+-const Decimal HTMLInputElement::kStepScaleFactorMonth = Decimal(1);
+-const Decimal HTMLInputElement::kStepScaleFactorWeek = Decimal(7 * 86400000);
+-const Decimal HTMLInputElement::kDefaultStepBase = Decimal(0);
+-const Decimal HTMLInputElement::kDefaultStepBaseWeek = Decimal(-259200000);
+-const Decimal HTMLInputElement::kDefaultStep = Decimal(1);
+-const Decimal HTMLInputElement::kDefaultStepTime = Decimal(60);
+-const Decimal HTMLInputElement::kStepAny = Decimal(0);
++using namespace blink;
++
++constexpr Decimal HTMLInputElement::kStepScaleFactorDate(86400000_d);
++constexpr Decimal HTMLInputElement::kStepScaleFactorNumberRange(1_d);
++constexpr Decimal HTMLInputElement::kStepScaleFactorTime(1000_d);
++constexpr Decimal HTMLInputElement::kStepScaleFactorMonth(1_d);
++constexpr Decimal HTMLInputElement::kStepScaleFactorWeek(7 * 86400000_d);
++constexpr Decimal HTMLInputElement::kDefaultStepBase(0_d);
++constexpr Decimal HTMLInputElement::kDefaultStepBaseWeek(-259200000_d);
++constexpr Decimal HTMLInputElement::kDefaultStep(1_d);
++constexpr Decimal HTMLInputElement::kDefaultStepTime(60_d);
++constexpr Decimal HTMLInputElement::kStepAny(0_d);
+ 
+ const double HTMLInputElement::kMinimumYear = 1;
+ const double HTMLInputElement::kMaximumYear = 275760;
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+index cc828e28439f5..7d2bcfa712c5d 100644
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -41,12 +41,6 @@ namespace blink {
+ 
+ namespace DecimalPrivate {
+ 
+-static int const ExponentMax = 1023;
+-static int const ExponentMin = -1023;
+-static int const Precision = 18;
+-
+-static const uint64_t MaxCoefficient = UINT64_C(0xDE0B6B3A763FFFF); // 999999999999999999 == 18 9's
+-
+ // This class handles Decimal special values.
+ class SpecialValueHandler {
+     STACK_ALLOCATED();
+@@ -230,43 +224,6 @@ static uint64_t scaleUp(uint64_t x, int n)
+ 
+ using namespace DecimalPrivate;
+ 
+-Decimal::EncodedData::EncodedData(Sign sign, FormatClass formatClass)
+-    : m_coefficient(0)
+-    , m_exponent(0)
+-    , m_formatClass(formatClass)
+-    , m_sign(sign)
+-{
+-}
+-
+-Decimal::EncodedData::EncodedData(Sign sign, int exponent, uint64_t coefficient)
+-    : m_formatClass(coefficient ? ClassNormal : ClassZero)
+-    , m_sign(sign)
+-{
+-    if (exponent >= ExponentMin && exponent <= ExponentMax) {
+-        while (coefficient > MaxCoefficient) {
+-            coefficient /= 10;
+-            ++exponent;
+-        }
+-    }
+-
+-    if (exponent > ExponentMax) {
+-        m_coefficient = 0;
+-        m_exponent = 0;
+-        m_formatClass = ClassInfinity;
+-        return;
+-    }
+-
+-    if (exponent < ExponentMin) {
+-        m_coefficient = 0;
+-        m_exponent = 0;
+-        m_formatClass = ClassZero;
+-        return;
+-    }
+-
+-    m_coefficient = coefficient;
+-    m_exponent = static_cast<int16_t>(exponent);
+-}
+-
+ bool Decimal::EncodedData::operator==(const EncodedData& another) const
+ {
+     return m_sign == another.m_sign
+@@ -275,15 +232,12 @@ bool Decimal::EncodedData::operator==(const EncodedData& another) const
+         && m_coefficient == another.m_coefficient;
+ }
+ 
++
+ Decimal::Decimal(int32_t i32)
+-    : m_data(i32 < 0 ? Negative : Positive, 0, i32 < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32)) : static_cast<uint64_t>(i32))
+-{
+-}
++    : Decimal(DecimalLiteral{i32}) {}
+ 
+ Decimal::Decimal(Sign sign, int exponent, uint64_t coefficient)
+-    : m_data(sign, coefficient ? exponent : 0, coefficient)
+-{
+-}
++    : m_data(sign, coefficient ? exponent : 0, coefficient) {}
+ 
+ Decimal::Decimal(const EncodedData& data)
+     : m_data(data)
+diff --git a/mozglue/misc/decimal/Decimal.h b/mozglue/misc/decimal/Decimal.h
+index 10d0e2c7cefa3..4bb9a841e585f 100644
+--- a/mozglue/misc/decimal/Decimal.h
++++ b/mozglue/misc/decimal/Decimal.h
+@@ -65,9 +65,28 @@
+ namespace blink {
+ 
+ namespace DecimalPrivate {
++constexpr int ExponentMax = 1023;
++constexpr int ExponentMin = -1023;
++constexpr int Precision = 18;
++
++static const uint64_t MaxCoefficient = UINT64_C(0xDE0B6B3A763FFFF);  // 999999999999999999 == 18 9's
+ class SpecialValueHandler;
+ }
+ 
++struct DecimalLiteral {
++  int32_t value;
++  friend constexpr DecimalLiteral operator*(int32_t lhs, DecimalLiteral rhs) {
++    return {lhs * rhs.value};
++  }
++  constexpr DecimalLiteral operator-() {
++    return {-value};
++  }
++};
++
++constexpr DecimalLiteral operator""_d(unsigned long long value) {
++  return {static_cast<int32_t>(value)};
++}
++
+ // This class represents decimal base floating point number.
+ //
+ // FIXME: Once all C++ compiler support decimal type, we should replace this
+@@ -88,7 +107,32 @@ public:
+         friend class Decimal;
+         friend class DecimalPrivate::SpecialValueHandler;
+     public:
+-        EncodedData(Sign, int exponent, uint64_t coefficient);
++     constexpr EncodedData(Sign sign, int exponent, uint64_t coefficient)
++         : m_coefficient(0),
++           m_exponent(0),
++           m_formatClass(coefficient ? ClassNormal : ClassZero),
++           m_sign(sign) {
++       if (exponent >= DecimalPrivate::ExponentMin &&
++           exponent <= DecimalPrivate::ExponentMax) {
++         while (coefficient > DecimalPrivate::MaxCoefficient) {
++           coefficient /= 10;
++           ++exponent;
++         }
++       }
++
++       if (exponent > DecimalPrivate::ExponentMax) {
++         m_formatClass = ClassInfinity;
++         return;
++       }
++
++       if (exponent < DecimalPrivate::ExponentMin) {
++         m_formatClass = ClassZero;
++         return;
++       }
++
++       m_coefficient = coefficient;
++       m_exponent = static_cast<int16_t>(exponent);
++     }
+ 
+         bool operator==(const EncodedData&) const;
+         bool operator!=(const EncodedData& another) const { return !operator==(another); }
+@@ -112,7 +156,12 @@ public:
+             ClassZero,
+         };
+ 
+-        EncodedData(Sign, FormatClass);
++        constexpr EncodedData(Sign sign, FormatClass formatClass)
++            : m_coefficient(0),
++              m_exponent(0),
++              m_formatClass(formatClass),
++              m_sign(sign) {}
++
+         FormatClass formatClass() const { return m_formatClass; }
+ 
+         uint64_t m_coefficient;
+@@ -121,8 +170,13 @@ public:
+         Sign m_sign;
+     };
+ 
+-    MFBT_API explicit Decimal(int32_t = 0);
+-    MFBT_API Decimal(Sign, int exponent, uint64_t coefficient);
++    constexpr explicit Decimal(DecimalLiteral i32)
++    : m_data(i32.value < 0 ? Negative : Positive, 0,
++             i32.value < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32.value))
++                     : static_cast<uint64_t>(i32.value)) {}
++
++    MFBT_API explicit Decimal(int32_t i32 = 0);
++    MFBT_API Decimal(Sign sign, int exponent, uint64_t coefficient);
+     MFBT_API Decimal(const Decimal&);
+ 
+     MFBT_API Decimal& operator=(const Decimal&);
+@@ -209,6 +263,7 @@ private:
+ 
+ namespace mozilla {
+ typedef blink::Decimal Decimal;
++using blink::operator""_d;
+ } // namespace mozilla
+ 
+ #undef USING_FAST_MALLOC
diff --git a/mozglue/misc/decimal/moz-decimal-utils.h b/mozglue/misc/decimal/moz-decimal-utils.h
new file mode 100644
index 0000000000..05ea61e4bd
--- /dev/null
+++ b/mozglue/misc/decimal/moz-decimal-utils.h
@@ -0,0 +1,110 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 MOZ_DECIMAL_UTILS_H
+#define MOZ_DECIMAL_UTILS_H
+
+// This file contains extra includes, defines and typedefs to allow compilation
+// of Decimal.cpp under the Mozilla source without blink core dependencies. Do
+// not include it into any file other than Decimal.cpp.
+
+#include "double-conversion/double-conversion.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Casting.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/Span.h"
+
+#include <cmath>
+#include <cstring>
+#include <iomanip>
+#include <limits>
+#include <sstream>
+
+#ifndef UINT64_C
+// For Android toolchain
+#define UINT64_C(c) (c ## ULL)
+#endif
+
+#ifdef ASSERT
+#undef ASSERT
+#endif
+#define ASSERT MOZ_ASSERT
+
+#define ASSERT_NOT_REACHED() MOZ_ASSERT_UNREACHABLE("moz-decimal-utils.h")
+
+#define STACK_ALLOCATED() DISALLOW_NEW()
+
+#define WTF_MAKE_NONCOPYABLE(ClassName) \
+  private: \
+    ClassName(const ClassName&) = delete; \
+    void operator=(const ClassName&) = delete;
+
+typedef std::string String;
+
+double mozToDouble(mozilla::Span<const char> aStr, bool *valid) {
+  double_conversion::StringToDoubleConverter converter(
+    double_conversion::StringToDoubleConverter::NO_FLAGS,
+    mozilla::UnspecifiedNaN<double>(), mozilla::UnspecifiedNaN<double>(), nullptr, nullptr);
+  const char* str = aStr.Elements();
+  int length = mozilla::AssertedCast<int>(aStr.Length());
+  int processed_char_count; // unused - NO_FLAGS requires the whole string to parse
+  double result = converter.StringToDouble(str, length, &processed_char_count);
+  *valid = std::isfinite(result);
+  return result;
+}
+
+double mozToDouble(const String &aStr, bool *valid) {
+  return mozToDouble(mozilla::MakeStringSpan(aStr.c_str()), valid);
+}
+
+String mozToString(double aNum) {
+  char buffer[64];
+  int buffer_length = mozilla::ArrayLength(buffer);
+  const double_conversion::DoubleToStringConverter& converter =
+    double_conversion::DoubleToStringConverter::EcmaScriptConverter();
+  double_conversion::StringBuilder builder(buffer, buffer_length);
+  converter.ToShortest(aNum, &builder);
+  return String(builder.Finalize());
+}
+
+String mozToString(int64_t aNum) {
+  std::ostringstream o;
+  o << std::setprecision(std::numeric_limits<int64_t>::digits10) << aNum;
+  return o.str();
+}
+
+String mozToString(uint64_t aNum) {
+  std::ostringstream o;
+  o << std::setprecision(std::numeric_limits<uint64_t>::digits10) << aNum;
+  return o.str();
+}
+
+namespace moz_decimal_utils {
+
+class StringBuilder
+{
+public:
+  void append(char c) {
+    mStr += c;
+  }
+  void appendLiteral(const char *aStr) {
+    mStr += aStr;
+  }
+  void appendNumber(int aNum) {
+    mStr += mozToString(int64_t(aNum));
+  }
+  void append(const String& aStr) {
+    mStr += aStr;
+  }
+  std::string toString() const {
+    return mStr;
+  }
+private:
+  std::string mStr;
+};
+
+} // namespace moz_decimal_utils
+
+#endif
diff --git a/mozglue/misc/decimal/to-moz-dependencies.patch b/mozglue/misc/decimal/to-moz-dependencies.patch
new file mode 100644
index 0000000000..bf19a6da96
--- /dev/null
+++ b/mozglue/misc/decimal/to-moz-dependencies.patch
@@ -0,0 +1,224 @@
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -23,22 +23,20 @@
+  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  */
+ 
+-#include "platform/Decimal.h"
++#include "Decimal.h"
++#include "moz-decimal-utils.h"
+ 
+-#include "wtf/Allocator.h"
+-#include "wtf/MathExtras.h"
+-#include "wtf/Noncopyable.h"
+-#include "wtf/text/StringBuilder.h"
++using namespace moz_decimal_utils;
+ 
+ #include <algorithm>
+ #include <float.h>
+ 
+ namespace blink {
+ 
+ namespace DecimalPrivate {
+ 
+@@ -690,17 +688,17 @@ Decimal Decimal::floor() const
+     if (isNegative() && !isMultiplePowersOfTen(m_data.coefficient(), numberOfDropDigits))
+         ++result;
+     return Decimal(sign(), 0, result);
+ }
+ 
+ Decimal Decimal::fromDouble(double doubleValue)
+ {
+     if (std::isfinite(doubleValue))
+-        return fromString(String::numberToStringECMAScript(doubleValue));
++        return fromString(mozToString(doubleValue));
+ 
+     if (std::isinf(doubleValue))
+         return infinity(doubleValue < 0 ? Negative : Positive);
+ 
+     return nan();
+ }
+ 
+ Decimal Decimal::fromString(const String& str)
+@@ -931,17 +929,17 @@ Decimal Decimal::round() const
+     result /= 10;
+     return Decimal(sign(), 0, result);
+ }
+ 
+ double Decimal::toDouble() const
+ {
+     if (isFinite()) {
+         bool valid;
+-        const double doubleValue = toString().toDouble(&valid);
++        const double doubleValue = mozToDouble(toString(), &valid);
+         return valid ? doubleValue : std::numeric_limits<double>::quiet_NaN();
+     }
+ 
+     if (isInfinity())
+         return isNegative() ? -std::numeric_limits<double>::infinity() : std::numeric_limits<double>::infinity();
+ 
+     return std::numeric_limits<double>::quiet_NaN();
+ }
+@@ -984,17 +982,17 @@ String Decimal::toString() const
+             ++coefficient;
+ 
+         while (originalExponent < 0 && coefficient && !(coefficient % 10)) {
+             coefficient /= 10;
+             ++originalExponent;
+         }
+     }
+ 
+-    const String digits = String::number(coefficient);
++    const String digits = mozToString(coefficient);
+     int coefficientLength = static_cast<int>(digits.length());
+     const int adjustedExponent = originalExponent + coefficientLength - 1;
+     if (originalExponent <= 0 && adjustedExponent >= -6) {
+         if (!originalExponent) {
+             builder.append(digits);
+             return builder.toString();
+         }
+ 
+@@ -1026,14 +1024,27 @@ String Decimal::toString() const
+         if (adjustedExponent) {
+             builder.append(adjustedExponent < 0 ? "e" : "e+");
+             builder.appendNumber(adjustedExponent);
+         }
+     }
+     return builder.toString();
+ }
+ 
++bool Decimal::toString(char* strBuf, size_t bufLength) const
++{
++  ASSERT(bufLength > 0);
++  String str = toString();
++  size_t length = str.copy(strBuf, bufLength);
++  if (length < bufLength) {
++    strBuf[length] = '\0';
++    return true;
++  }
++  strBuf[bufLength - 1] = '\0';
++  return false;
++}
++
+ Decimal Decimal::zero(Sign sign)
+ {
+     return Decimal(EncodedData(sign, EncodedData::ClassZero));
+ }
+ 
+ } // namespace blink
+diff --git a/mozglue/misc/decimal/Decimal.h b/mozglue/misc/decimal/Decimal.h
+--- a/mozglue/misc/decimal/Decimal.h
++++ b/mozglue/misc/decimal/Decimal.h
+@@ -23,26 +23,49 @@
+  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  */
+ 
++/**
++ * Imported from:
++ * https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/platform/Decimal.h
++ * Check UPSTREAM-GIT-SHA for the commit ID of the last update from Blink core.
++ */
++
+ #ifndef Decimal_h
+ #define Decimal_h
+ 
++#include "mozilla/Assertions.h"
++#include <stdint.h>
+ #include "mozilla/Types.h"
+ 
+-#include "platform/PlatformExport.h"
+-#include "wtf/Allocator.h"
+-#include "wtf/Assertions.h"
+-#include "wtf/text/WTFString.h"
+-#include <stdint.h>
++#include <string>
++
++#ifndef ASSERT
++#define DEFINED_ASSERT_FOR_DECIMAL_H 1
++#define ASSERT MOZ_ASSERT
++#endif
++
++#define PLATFORM_EXPORT
++
++// To use USING_FAST_MALLOC we'd need:
++// https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/wtf/Allocator.h
++// Since we don't allocate Decimal objects, no need.
++#define USING_FAST_MALLOC(type) \
++  void ignore_this_dummy_method() = delete
++
++#define DISALLOW_NEW()                                          \
++    private:                                                    \
++        void* operator new(size_t) = delete;                    \
++        void* operator new(size_t, void*) = delete;             \
++    public:
+ 
+ namespace blink {
+ 
+ namespace DecimalPrivate {
+ class SpecialValueHandler;
+ }
+ 
+ // This class represents decimal base floating point number.
+@@ -139,27 +162,28 @@ public:
+     MFBT_API Decimal abs() const;
+     MFBT_API Decimal ceil() const;
+     MFBT_API Decimal floor() const;
+     MFBT_API Decimal remainder(const Decimal&) const;
+     MFBT_API Decimal round() const;
+ 
+     MFBT_API double toDouble() const;
+     // Note: toString method supports infinity and nan but fromString not.
+-    MFBT_API String toString() const;
++    MFBT_API std::string toString() const;
++    MFBT_API bool toString(char* strBuf, size_t bufLength) const;
+ 
+     static MFBT_API Decimal fromDouble(double);
+     // fromString supports following syntax EBNF:
+     //  number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)?
+     //          | sign? '.' digit+ (exponent-marker sign? digit+)?
+     //  sign ::= '+' | '-'
+     //  exponent-marker ::= 'e' | 'E'
+     //  digit ::= '0' | '1' | ... | '9'
+     // Note: fromString doesn't support "infinity" and "nan".
+-    static MFBT_API Decimal fromString(const String&);
++    static MFBT_API Decimal fromString(const std::string& aValue);
+     static MFBT_API Decimal infinity(Sign);
+     static MFBT_API Decimal nan();
+     static MFBT_API Decimal zero(Sign);
+ 
+     // You should not use below methods. We expose them for unit testing.
+     MFBT_API explicit Decimal(const EncodedData&);
+     const EncodedData& value() const { return m_data; }
+ 
+@@ -178,9 +202,20 @@ private:
+ 
+     Sign sign() const { return m_data.sign(); }
+ 
+     EncodedData m_data;
+ };
+ 
+ } // namespace blink
+ 
++namespace mozilla {
++typedef blink::Decimal Decimal;
++} // namespace mozilla
++
++#undef USING_FAST_MALLOC
++
++#ifdef DEFINED_ASSERT_FOR_DECIMAL_H
++#undef DEFINED_ASSERT_FOR_DECIMAL_H
++#undef ASSERT
++#endif
++
+ #endif // Decimal_h
diff --git a/mozglue/misc/decimal/update.sh b/mozglue/misc/decimal/update.sh
new file mode 100755
index 0000000000..696685f9ba
--- /dev/null
+++ b/mozglue/misc/decimal/update.sh
@@ -0,0 +1,61 @@
+# Usage: ./update.sh [blink-core-source-directory]
+#
+# Copies the needed files from a directory containing the original
+# Decimal.h and Decimal.cpp source that we need.
+# If [blink-core-source-directory] is not specified, this script will
+# attempt to download the latest versions using git.
+
+set -e
+
+FILES=(
+  "Decimal.h"
+  "Decimal.cpp"
+)
+
+OWN_NAME=`basename $0`
+
+if [ $# -gt 1 ]; then
+  echo "$OWN_NAME: Too many arguments">&2
+  exit 1
+fi
+
+if [ $# -eq 1 ]; then
+  BLINK_CORE_DIR="$1"
+  for F in "${FILES[@]}"
+  do
+    P="$BLINK_CORE_DIR/$F"
+    if [ ! -f "$P" ]; then
+      echo "$OWN_NAME: Couldn't find file: $P">&2
+      exit 1
+    fi
+  done
+  for F in "${FILES[@]}"
+  do
+    P="$BLINK_CORE_DIR/$F"
+    cp "$P" .
+  done
+else
+  #LATEST_SHA=$(cat UPSTREAM-GIT-SHA)
+  LATEST_SHA=$(git ls-remote https://chromium.googlesource.com/chromium/src.git/ | awk "/refs\/heads\/master/ {print \$1}")
+  REPO_PATH="https://chromium.googlesource.com/chromium/src.git/+/$LATEST_SHA/third_party/WebKit/Source/platform"
+  #REPO_PATH="https://github.com/WebKit/webkit/tree/master/Source/WebCore/platform"
+  for F in "${FILES[@]}"
+  do
+    printf "Downloading `basename $F`..."
+    curl "$REPO_PATH/${F}?format=TEXT" | base64 -D > "$F"
+    echo done.
+  done
+  echo $LATEST_SHA > UPSTREAM-GIT-SHA
+fi
+
+# Apply patches:
+
+patch -p4 < zero-serialization.patch
+patch -p4 < comparison-with-nan.patch
+patch -p4 < mfbt-abi-markers.patch
+patch -p4 < to-moz-dependencies.patch
+patch -p4 < add-doubleconversion-impl.patch
+patch -p4 < moz-constexpr-decimal.patch
+# The following is disabled. See
+# https://bugzilla.mozilla.org/show_bug.cgi?id=1208357#c7
+#patch -p4 < fix-wshadow-warnings.patch
diff --git a/mozglue/misc/decimal/zero-serialization.patch b/mozglue/misc/decimal/zero-serialization.patch
new file mode 100644
index 0000000000..b8de9241bd
--- /dev/null
+++ b/mozglue/misc/decimal/zero-serialization.patch
@@ -0,0 +1,22 @@
+diff --git a/mozglue/misc/decimal/Decimal.cpp b/mozglue/misc/decimal/Decimal.cpp
+--- a/mozglue/misc/decimal/Decimal.cpp
++++ b/mozglue/misc/decimal/Decimal.cpp
+@@ -277,17 +277,17 @@ bool Decimal::EncodedData::operator==(co
+ }
+ 
+ Decimal::Decimal(int32_t i32)
+     : m_data(i32 < 0 ? Negative : Positive, 0, i32 < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32)) : static_cast<uint64_t>(i32))
+ {
+ }
+ 
+ Decimal::Decimal(Sign sign, int exponent, uint64_t coefficient)
+-    : m_data(sign, exponent, coefficient)
++    : m_data(sign, coefficient ? exponent : 0, coefficient)
+ {
+ }
+ 
+ Decimal::Decimal(const EncodedData& data)
+     : m_data(data)
+ {
+ }
+