Add m-esr52 at 52.6.0

1 files changed, 1922 insertions, 0 deletions

diff --git a/js/src/jsnum.cpp b/js/src/jsnum.cpp
new file mode 100644
index 000000000..8885737f7
--- /dev/null
+++ b/js/src/jsnum.cpp
@@ -0,0 +1,1922 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 number type and wrapper class.
+ */
+
+#include "jsnum.h"
+
+#include "mozilla/double-conversion.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/PodOperations.h"
+#include "mozilla/RangedPtr.h"
+
+#ifdef HAVE_LOCALECONV
+#include <locale.h>
+#endif
+#include <math.h>
+#include <string.h>
+
+#include "jsatom.h"
+#include "jscntxt.h"
+#include "jsdtoa.h"
+#include "jsobj.h"
+#include "jsstr.h"
+#include "jstypes.h"
+
+#include "js/Conversions.h"
+#include "vm/GlobalObject.h"
+#include "vm/StringBuffer.h"
+
+#include "jsatominlines.h"
+
+#include "vm/NativeObject-inl.h"
+#include "vm/NumberObject-inl.h"
+#include "vm/String-inl.h"
+
+using namespace js;
+
+using mozilla::Abs;
+using mozilla::ArrayLength;
+using mozilla::MinNumberValue;
+using mozilla::NegativeInfinity;
+using mozilla::PodCopy;
+using mozilla::PositiveInfinity;
+using mozilla::RangedPtr;
+
+using JS::AutoCheckCannotGC;
+using JS::GenericNaN;
+using JS::ToInt8;
+using JS::ToInt16;
+using JS::ToInt32;
+using JS::ToInt64;
+using JS::ToUint32;
+using JS::ToUint64;
+
+/*
+ * If we're accumulating a decimal number and the number is >= 2^53, then the
+ * fast result from the loop in Get{Prefix,Decimal}Integer may be inaccurate.
+ * Call js_strtod_harder to get the correct answer.
+ */
+template <typename CharT>
+static bool
+ComputeAccurateDecimalInteger(ExclusiveContext* cx, const CharT* start, const CharT* end,
+                              double* dp)
+{
+    size_t length = end - start;
+    ScopedJSFreePtr<char> cstr(cx->pod_malloc<char>(length + 1));
+    if (!cstr)
+        return false;
+
+    for (size_t i = 0; i < length; i++) {
+        char c = char(start[i]);
+        MOZ_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'));
+        cstr[i] = c;
+    }
+    cstr[length] = 0;
+
+    char* estr;
+    int err = 0;
+    *dp = js_strtod_harder(cx->dtoaState(), cstr, &estr, &err);
+    if (err == JS_DTOA_ENOMEM) {
+        ReportOutOfMemory(cx);
+        return false;
+    }
+
+    return true;
+}
+
+namespace {
+
+template <typename CharT>
+class BinaryDigitReader
+{
+    const int base;      /* Base of number; must be a power of 2 */
+    int digit;           /* Current digit value in radix given by base */
+    int digitMask;       /* Mask to extract the next bit from digit */
+    const CharT* start;  /* Pointer to the remaining digits */
+    const CharT* end;    /* Pointer to first non-digit */
+
+  public:
+    BinaryDigitReader(int base, const CharT* start, const CharT* end)
+      : base(base), digit(0), digitMask(0), start(start), end(end)
+    {
+    }
+
+    /* Return the next binary digit from the number, or -1 if done. */
+    int nextDigit() {
+        if (digitMask == 0) {
+            if (start == end)
+                return -1;
+
+            int c = *start++;
+            MOZ_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'));
+            if ('0' <= c && c <= '9')
+                digit = c - '0';
+            else if ('a' <= c && c <= 'z')
+                digit = c - 'a' + 10;
+            else
+                digit = c - 'A' + 10;
+            digitMask = base >> 1;
+        }
+
+        int bit = (digit & digitMask) != 0;
+        digitMask >>= 1;
+        return bit;
+    }
+};
+
+} /* anonymous namespace */
+
+/*
+ * The fast result might also have been inaccurate for power-of-two bases. This
+ * happens if the addition in value * 2 + digit causes a round-down to an even
+ * least significant mantissa bit when the first dropped bit is a one.  If any
+ * of the following digits in the number (which haven't been added in yet) are
+ * nonzero, then the correct action would have been to round up instead of
+ * down.  An example occurs when reading the number 0x1000000000000081, which
+ * rounds to 0x1000000000000000 instead of 0x1000000000000100.
+ */
+template <typename CharT>
+static double
+ComputeAccurateBinaryBaseInteger(const CharT* start, const CharT* end, int base)
+{
+    BinaryDigitReader<CharT> bdr(base, start, end);
+
+    /* Skip leading zeroes. */
+    int bit;
+    do {
+        bit = bdr.nextDigit();
+    } while (bit == 0);
+
+    MOZ_ASSERT(bit == 1); // guaranteed by Get{Prefix,Decimal}Integer
+
+    /* Gather the 53 significant bits (including the leading 1). */
+    double value = 1.0;
+    for (int j = 52; j > 0; j--) {
+        bit = bdr.nextDigit();
+        if (bit < 0)
+            return value;
+        value = value * 2 + bit;
+    }
+
+    /* bit2 is the 54th bit (the first dropped from the mantissa). */
+    int bit2 = bdr.nextDigit();
+    if (bit2 >= 0) {
+        double factor = 2.0;
+        int sticky = 0;  /* sticky is 1 if any bit beyond the 54th is 1 */
+        int bit3;
+
+        while ((bit3 = bdr.nextDigit()) >= 0) {
+            sticky |= bit3;
+            factor *= 2;
+        }
+        value += bit2 & (bit | sticky);
+        value *= factor;
+    }
+
+    return value;
+}
+
+template <typename CharT>
+double
+js::ParseDecimalNumber(const mozilla::Range<const CharT> chars)
+{
+    MOZ_ASSERT(chars.length() > 0);
+    uint64_t dec = 0;
+    RangedPtr<const CharT> s = chars.begin(), end = chars.end();
+    do {
+        CharT c = *s;
+        MOZ_ASSERT('0' <= c && c <= '9');
+        uint8_t digit = c - '0';
+        uint64_t next = dec * 10 + digit;
+        MOZ_ASSERT(next < DOUBLE_INTEGRAL_PRECISION_LIMIT,
+                   "next value won't be an integrally-precise double");
+        dec = next;
+    } while (++s < end);
+    return static_cast<double>(dec);
+}
+
+template double
+js::ParseDecimalNumber(const mozilla::Range<const Latin1Char> chars);
+
+template double
+js::ParseDecimalNumber(const mozilla::Range<const char16_t> chars);
+
+template <typename CharT>
+bool
+js::GetPrefixInteger(ExclusiveContext* cx, const CharT* start, const CharT* end, int base,
+                     const CharT** endp, double* dp)
+{
+    MOZ_ASSERT(start <= end);
+    MOZ_ASSERT(2 <= base && base <= 36);
+
+    const CharT* s = start;
+    double d = 0.0;
+    for (; s < end; s++) {
+        int digit;
+        CharT c = *s;
+        if ('0' <= c && c <= '9')
+            digit = c - '0';
+        else if ('a' <= c && c <= 'z')
+            digit = c - 'a' + 10;
+        else if ('A' <= c && c <= 'Z')
+            digit = c - 'A' + 10;
+        else
+            break;
+        if (digit >= base)
+            break;
+        d = d * base + digit;
+    }
+
+    *endp = s;
+    *dp = d;
+
+    /* If we haven't reached the limit of integer precision, we're done. */
+    if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT)
+        return true;
+
+    /*
+     * Otherwise compute the correct integer from the prefix of valid digits
+     * if we're computing for base ten or a power of two.  Don't worry about
+     * other bases; see 15.1.2.2 step 13.
+     */
+    if (base == 10)
+        return ComputeAccurateDecimalInteger(cx, start, s, dp);
+
+    if ((base & (base - 1)) == 0)
+        *dp = ComputeAccurateBinaryBaseInteger(start, s, base);
+
+    return true;
+}
+
+template bool
+js::GetPrefixInteger(ExclusiveContext* cx, const char16_t* start, const char16_t* end, int base,
+                     const char16_t** endp, double* dp);
+
+template bool
+js::GetPrefixInteger(ExclusiveContext* cx, const Latin1Char* start, const Latin1Char* end,
+                     int base, const Latin1Char** endp, double* dp);
+
+bool
+js::GetDecimalInteger(ExclusiveContext* cx, const char16_t* start, const char16_t* end, double* dp)
+{
+    MOZ_ASSERT(start <= end);
+
+    const char16_t* s = start;
+    double d = 0.0;
+    for (; s < end; s++) {
+        char16_t c = *s;
+        MOZ_ASSERT('0' <= c && c <= '9');
+        int digit = c - '0';
+        d = d * 10 + digit;
+    }
+
+    *dp = d;
+
+    // If we haven't reached the limit of integer precision, we're done.
+    if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT)
+        return true;
+
+    // Otherwise compute the correct integer from the prefix of valid digits.
+    return ComputeAccurateDecimalInteger(cx, start, s, dp);
+}
+
+static bool
+num_parseFloat(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    if (args.length() == 0) {
+        args.rval().setNaN();
+        return true;
+    }
+
+    JSString* str = ToString<CanGC>(cx, args[0]);
+    if (!str)
+        return false;
+
+    JSLinearString* linear = str->ensureLinear(cx);
+    if (!linear)
+        return false;
+
+    double d;
+    AutoCheckCannotGC nogc;
+    if (linear->hasLatin1Chars()) {
+        const Latin1Char* begin = linear->latin1Chars(nogc);
+        const Latin1Char* end;
+        if (!js_strtod(cx, begin, begin + linear->length(), &end, &d))
+            return false;
+        if (end == begin)
+            d = GenericNaN();
+    } else {
+        const char16_t* begin = linear->twoByteChars(nogc);
+        const char16_t* end;
+        if (!js_strtod(cx, begin, begin + linear->length(), &end, &d))
+            return false;
+        if (end == begin)
+            d = GenericNaN();
+    }
+
+    args.rval().setDouble(d);
+    return true;
+}
+
+template <typename CharT>
+static bool
+ParseIntImpl(JSContext* cx, const CharT* chars, size_t length, bool stripPrefix, int32_t radix,
+             double* res)
+{
+    /* Step 2. */
+    const CharT* end = chars + length;
+    const CharT* s = SkipSpace(chars, end);
+
+    MOZ_ASSERT(chars <= s);
+    MOZ_ASSERT(s <= end);
+
+    /* Steps 3-4. */
+    bool negative = (s != end && s[0] == '-');
+
+    /* Step 5. */
+    if (s != end && (s[0] == '-' || s[0] == '+'))
+        s++;
+
+    /* Step 10. */
+    if (stripPrefix) {
+        if (end - s >= 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) {
+            s += 2;
+            radix = 16;
+        }
+    }
+
+    /* Steps 11-15. */
+    const CharT* actualEnd;
+    double d;
+    if (!GetPrefixInteger(cx, s, end, radix, &actualEnd, &d))
+        return false;
+
+    if (s == actualEnd)
+        *res = GenericNaN();
+    else
+        *res = negative ? -d : d;
+    return true;
+}
+
+/* ES5 15.1.2.2. */
+bool
+js::num_parseInt(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Fast paths and exceptional cases. */
+    if (args.length() == 0) {
+        args.rval().setNaN();
+        return true;
+    }
+
+    if (args.length() == 1 ||
+        (args[1].isInt32() && (args[1].toInt32() == 0 || args[1].toInt32() == 10))) {
+        if (args[0].isInt32()) {
+            args.rval().set(args[0]);
+            return true;
+        }
+
+        /*
+         * Step 1 is |inputString = ToString(string)|. When string >=
+         * 1e21, ToString(string) is in the form "NeM". 'e' marks the end of
+         * the word, which would mean the result of parseInt(string) should be |N|.
+         *
+         * To preserve this behaviour, we can't use the fast-path when string >
+         * 1e21, or else the result would be |NeM|.
+         *
+         * The same goes for values smaller than 1.0e-6, because the string would be in
+         * the form of "Ne-M".
+         */
+        if (args[0].isDouble()) {
+            double d = args[0].toDouble();
+            if (1.0e-6 < d && d < 1.0e21) {
+                args.rval().setNumber(floor(d));
+                return true;
+            }
+            if (-1.0e21 < d && d < -1.0e-6) {
+                args.rval().setNumber(-floor(-d));
+                return true;
+            }
+            if (d == 0.0) {
+                args.rval().setInt32(0);
+                return true;
+            }
+        }
+    }
+
+    /* Step 1. */
+    RootedString inputString(cx, ToString<CanGC>(cx, args[0]));
+    if (!inputString)
+        return false;
+    args[0].setString(inputString);
+
+    /* Steps 6-9. */
+    bool stripPrefix = true;
+    int32_t radix;
+    if (!args.hasDefined(1)) {
+        radix = 10;
+    } else {
+        if (!ToInt32(cx, args[1], &radix))
+            return false;
+        if (radix == 0) {
+            radix = 10;
+        } else {
+            if (radix < 2 || radix > 36) {
+                args.rval().setNaN();
+                return true;
+            }
+            if (radix != 16)
+                stripPrefix = false;
+        }
+    }
+
+    JSLinearString* linear = inputString->ensureLinear(cx);
+    if (!linear)
+        return false;
+
+    AutoCheckCannotGC nogc;
+    size_t length = inputString->length();
+    double number;
+    if (linear->hasLatin1Chars()) {
+        if (!ParseIntImpl(cx, linear->latin1Chars(nogc), length, stripPrefix, radix, &number))
+            return false;
+    } else {
+        if (!ParseIntImpl(cx, linear->twoByteChars(nogc), length, stripPrefix, radix, &number))
+            return false;
+    }
+
+    args.rval().setNumber(number);
+    return true;
+}
+
+static const JSFunctionSpec number_functions[] = {
+    JS_SELF_HOSTED_FN(js_isNaN_str, "Global_isNaN", 1, JSPROP_RESOLVING),
+    JS_SELF_HOSTED_FN(js_isFinite_str, "Global_isFinite", 1, JSPROP_RESOLVING),
+    JS_FS_END
+};
+
+const Class NumberObject::class_ = {
+    js_Number_str,
+    JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Number)
+};
+
+static bool
+Number(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Sample JS_CALLEE before clobbering. */
+    bool isConstructing = args.isConstructing();
+
+    if (args.length() > 0) {
+        if (!ToNumber(cx, args[0]))
+            return false;
+        args.rval().set(args[0]);
+    } else {
+        args.rval().setInt32(0);
+    }
+
+    if (!isConstructing)
+        return true;
+
+    RootedObject newTarget(cx, &args.newTarget().toObject());
+    RootedObject proto(cx);
+    if (!GetPrototypeFromConstructor(cx, newTarget, &proto))
+        return false;
+    JSObject* obj = NumberObject::create(cx, args.rval().toNumber(), proto);
+    if (!obj)
+        return false;
+    args.rval().setObject(*obj);
+    return true;
+}
+
+MOZ_ALWAYS_INLINE bool
+IsNumber(HandleValue v)
+{
+    return v.isNumber() || (v.isObject() && v.toObject().is<NumberObject>());
+}
+
+static inline double
+Extract(const Value& v)
+{
+    if (v.isNumber())
+        return v.toNumber();
+    return v.toObject().as<NumberObject>().unbox();
+}
+
+#if JS_HAS_TOSOURCE
+MOZ_ALWAYS_INLINE bool
+num_toSource_impl(JSContext* cx, const CallArgs& args)
+{
+    double d = Extract(args.thisv());
+
+    StringBuffer sb(cx);
+    if (!sb.append("(new Number(") ||
+        !NumberValueToStringBuffer(cx, NumberValue(d), sb) ||
+        !sb.append("))"))
+    {
+        return false;
+    }
+
+    JSString* str = sb.finishString();
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+}
+
+static bool
+num_toSource(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toSource_impl>(cx, args);
+}
+#endif
+
+ToCStringBuf::ToCStringBuf() : dbuf(nullptr)
+{
+    static_assert(sbufSize >= DTOSTR_STANDARD_BUFFER_SIZE,
+                  "builtin space must be large enough to store even the "
+                  "longest string produced by a conversion");
+}
+
+ToCStringBuf::~ToCStringBuf()
+{
+    js_free(dbuf);
+}
+
+MOZ_ALWAYS_INLINE
+static JSFlatString*
+LookupDtoaCache(ExclusiveContext* cx, double d)
+{
+    if (JSCompartment* comp = cx->compartment()) {
+        if (JSFlatString* str = comp->dtoaCache.lookup(10, d))
+            return str;
+    }
+
+    return nullptr;
+}
+
+MOZ_ALWAYS_INLINE
+static void
+CacheNumber(ExclusiveContext* cx, double d, JSFlatString* str)
+{
+    if (JSCompartment* comp = cx->compartment())
+        comp->dtoaCache.cache(10, d, str);
+}
+
+MOZ_ALWAYS_INLINE
+static JSFlatString*
+LookupInt32ToString(ExclusiveContext* cx, int32_t si)
+{
+    if (si >= 0 && StaticStrings::hasInt(si))
+        return cx->staticStrings().getInt(si);
+
+    return LookupDtoaCache(cx, si);
+}
+
+template <typename T>
+MOZ_ALWAYS_INLINE
+static T*
+BackfillInt32InBuffer(int32_t si, T* buffer, size_t size, size_t* length)
+{
+    uint32_t ui = Abs(si);
+    MOZ_ASSERT_IF(si == INT32_MIN, ui == uint32_t(INT32_MAX) + 1);
+
+    RangedPtr<T> end(buffer + size - 1, buffer, size);
+    *end = '\0';
+    RangedPtr<T> start = BackfillIndexInCharBuffer(ui, end);
+    if (si < 0)
+        *--start = '-';
+
+    *length = end - start;
+    return start.get();
+}
+
+template <AllowGC allowGC>
+JSFlatString*
+js::Int32ToString(ExclusiveContext* cx, int32_t si)
+{
+    if (JSFlatString* str = LookupInt32ToString(cx, si))
+        return str;
+
+    Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1];
+    size_t length;
+    Latin1Char* start = BackfillInt32InBuffer(si, buffer, ArrayLength(buffer), &length);
+
+    mozilla::Range<const Latin1Char> chars(start, length);
+    JSInlineString* str = NewInlineString<allowGC>(cx, chars);
+    if (!str)
+        return nullptr;
+
+    CacheNumber(cx, si, str);
+    return str;
+}
+
+template JSFlatString*
+js::Int32ToString<CanGC>(ExclusiveContext* cx, int32_t si);
+
+template JSFlatString*
+js::Int32ToString<NoGC>(ExclusiveContext* cx, int32_t si);
+
+JSAtom*
+js::Int32ToAtom(ExclusiveContext* cx, int32_t si)
+{
+    if (JSFlatString* str = LookupInt32ToString(cx, si))
+        return js::AtomizeString(cx, str);
+
+    char buffer[JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1];
+    size_t length;
+    char* start = BackfillInt32InBuffer(si, buffer, JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1, &length);
+
+    JSAtom* atom = Atomize(cx, start, length);
+    if (!atom)
+        return nullptr;
+
+    CacheNumber(cx, si, atom);
+    return atom;
+}
+
+/* Returns a non-nullptr pointer to inside cbuf.  */
+static char*
+Int32ToCString(ToCStringBuf* cbuf, int32_t i, size_t* len, int base = 10)
+{
+    uint32_t u = Abs(i);
+
+    RangedPtr<char> cp(cbuf->sbuf + ToCStringBuf::sbufSize - 1, cbuf->sbuf, ToCStringBuf::sbufSize);
+    char* end = cp.get();
+    *cp = '\0';
+
+    /* Build the string from behind. */
+    switch (base) {
+    case 10:
+      cp = BackfillIndexInCharBuffer(u, cp);
+      break;
+    case 16:
+      do {
+          unsigned newu = u / 16;
+          *--cp = "0123456789abcdef"[u - newu * 16];
+          u = newu;
+      } while (u != 0);
+      break;
+    default:
+      MOZ_ASSERT(base >= 2 && base <= 36);
+      do {
+          unsigned newu = u / base;
+          *--cp = "0123456789abcdefghijklmnopqrstuvwxyz"[u - newu * base];
+          u = newu;
+      } while (u != 0);
+      break;
+    }
+    if (i < 0)
+        *--cp = '-';
+
+    *len = end - cp.get();
+    return cp.get();
+}
+
+template <AllowGC allowGC>
+static JSString*
+NumberToStringWithBase(ExclusiveContext* cx, double d, int base);
+
+MOZ_ALWAYS_INLINE bool
+num_toString_impl(JSContext* cx, const CallArgs& args)
+{
+    MOZ_ASSERT(IsNumber(args.thisv()));
+
+    double d = Extract(args.thisv());
+
+    int32_t base = 10;
+    if (args.hasDefined(0)) {
+        double d2;
+        if (!ToInteger(cx, args[0], &d2))
+            return false;
+
+        if (d2 < 2 || d2 > 36) {
+            JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_RADIX);
+            return false;
+        }
+
+        base = int32_t(d2);
+    }
+    JSString* str = NumberToStringWithBase<CanGC>(cx, d, base);
+    if (!str) {
+        JS_ReportOutOfMemory(cx);
+        return false;
+    }
+    args.rval().setString(str);
+    return true;
+}
+
+bool
+js::num_toString(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toString_impl>(cx, args);
+}
+
+#if !EXPOSE_INTL_API
+MOZ_ALWAYS_INLINE bool
+num_toLocaleString_impl(JSContext* cx, const CallArgs& args)
+{
+    MOZ_ASSERT(IsNumber(args.thisv()));
+
+    double d = Extract(args.thisv());
+
+    RootedString str(cx, NumberToStringWithBase<CanGC>(cx, d, 10));
+    if (!str) {
+        JS_ReportOutOfMemory(cx);
+        return false;
+    }
+
+    /*
+     * Create the string, move back to bytes to make string twiddling
+     * a bit easier and so we can insert platform charset seperators.
+     */
+    JSAutoByteString numBytes(cx, str);
+    if (!numBytes)
+        return false;
+    const char* num = numBytes.ptr();
+    if (!num)
+        return false;
+
+    /*
+     * Find the first non-integer value, whether it be a letter as in
+     * 'Infinity', a decimal point, or an 'e' from exponential notation.
+     */
+    const char* nint = num;
+    if (*nint == '-')
+        nint++;
+    while (*nint >= '0' && *nint <= '9')
+        nint++;
+    int digits = nint - num;
+    const char* end = num + digits;
+    if (!digits) {
+        args.rval().setString(str);
+        return true;
+    }
+
+    JSRuntime* rt = cx->runtime();
+    size_t thousandsLength = strlen(rt->thousandsSeparator);
+    size_t decimalLength = strlen(rt->decimalSeparator);
+
+    /* Figure out how long resulting string will be. */
+    int buflen = strlen(num);
+    if (*nint == '.')
+        buflen += decimalLength - 1; /* -1 to account for existing '.' */
+
+    const char* numGrouping;
+    const char* tmpGroup;
+    numGrouping = tmpGroup = rt->numGrouping;
+    int remainder = digits;
+    if (*num == '-')
+        remainder--;
+
+    while (*tmpGroup != CHAR_MAX && *tmpGroup != '\0') {
+        if (*tmpGroup >= remainder)
+            break;
+        buflen += thousandsLength;
+        remainder -= *tmpGroup;
+        tmpGroup++;
+    }
+
+    int nrepeat;
+    if (*tmpGroup == '\0' && *numGrouping != '\0') {
+        nrepeat = (remainder - 1) / tmpGroup[-1];
+        buflen += thousandsLength * nrepeat;
+        remainder -= nrepeat * tmpGroup[-1];
+    } else {
+        nrepeat = 0;
+    }
+    tmpGroup--;
+
+    char* buf = cx->pod_malloc<char>(buflen + 1);
+    if (!buf)
+        return false;
+
+    char* tmpDest = buf;
+    const char* tmpSrc = num;
+
+    while (*tmpSrc == '-' || remainder--) {
+        MOZ_ASSERT(tmpDest - buf < buflen);
+        *tmpDest++ = *tmpSrc++;
+    }
+    while (tmpSrc < end) {
+        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(thousandsLength) <= buflen);
+        strcpy(tmpDest, rt->thousandsSeparator);
+        tmpDest += thousandsLength;
+        MOZ_ASSERT(tmpDest - buf + *tmpGroup <= buflen);
+        js_memcpy(tmpDest, tmpSrc, *tmpGroup);
+        tmpDest += *tmpGroup;
+        tmpSrc += *tmpGroup;
+        if (--nrepeat < 0)
+            tmpGroup--;
+    }
+
+    if (*nint == '.') {
+        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(decimalLength) <= buflen);
+        strcpy(tmpDest, rt->decimalSeparator);
+        tmpDest += decimalLength;
+        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint + 1)) <= buflen);
+        strcpy(tmpDest, nint + 1);
+    } else {
+        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint)) <= buflen);
+        strcpy(tmpDest, nint);
+    }
+
+    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeToUnicode) {
+        Rooted<Value> v(cx, StringValue(str));
+        bool ok = !!cx->runtime()->localeCallbacks->localeToUnicode(cx, buf, &v);
+        if (ok)
+            args.rval().set(v);
+        js_free(buf);
+        return ok;
+    }
+
+    str = NewStringCopyN<CanGC>(cx, buf, buflen);
+    js_free(buf);
+    if (!str)
+        return false;
+
+    args.rval().setString(str);
+    return true;
+}
+
+static bool
+num_toLocaleString(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toLocaleString_impl>(cx, args);
+}
+#endif /* !EXPOSE_INTL_API */
+
+MOZ_ALWAYS_INLINE bool
+num_valueOf_impl(JSContext* cx, const CallArgs& args)
+{
+    MOZ_ASSERT(IsNumber(args.thisv()));
+    args.rval().setNumber(Extract(args.thisv()));
+    return true;
+}
+
+bool
+js::num_valueOf(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_valueOf_impl>(cx, args);
+}
+
+static const unsigned MAX_PRECISION = 100;
+
+static bool
+ComputePrecisionInRange(JSContext* cx, int minPrecision, int maxPrecision, double prec,
+                        int* precision)
+{
+    if (minPrecision <= prec && prec <= maxPrecision) {
+        *precision = int(prec);
+        return true;
+    }
+
+    ToCStringBuf cbuf;
+    if (char* numStr = NumberToCString(cx, &cbuf, prec, 10))
+        JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_PRECISION_RANGE, numStr);
+    return false;
+}
+
+static bool
+DToStrResult(JSContext* cx, double d, JSDToStrMode mode, int precision, const CallArgs& args)
+{
+    char buf[DTOSTR_VARIABLE_BUFFER_SIZE(MAX_PRECISION + 1)];
+    char* numStr = js_dtostr(cx->mainThread().dtoaState, buf, sizeof buf, mode, precision, d);
+    if (!numStr) {
+        JS_ReportOutOfMemory(cx);
+        return false;
+    }
+    JSString* str = NewStringCopyZ<CanGC>(cx, numStr);
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+}
+
+/*
+ * In the following three implementations, we allow a larger range of precision
+ * than ECMA requires; this is permitted by ECMA-262.
+ */
+// ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.3.
+MOZ_ALWAYS_INLINE bool
+num_toFixed_impl(JSContext* cx, const CallArgs& args)
+{
+    // Step 1.
+    MOZ_ASSERT(IsNumber(args.thisv()));
+    double d = Extract(args.thisv());
+
+    // Steps 2-3.
+    int precision;
+    if (args.length() == 0) {
+        precision = 0;
+    } else {
+        double prec = 0;
+        if (!ToInteger(cx, args[0], &prec))
+            return false;
+
+        if (!ComputePrecisionInRange(cx, -20, MAX_PRECISION, prec, &precision))
+            return false;
+    }
+
+    // Step 4.
+    if (mozilla::IsNaN(d)) {
+        args.rval().setString(cx->names().NaN);
+        return true;
+    }
+
+    // Steps 5-7, 9 (optimized path for Infinity).
+    if (mozilla::IsInfinite(d)) {
+        if(d > 0) {
+            args.rval().setString(cx->names().Infinity);
+            return true;
+        }
+
+        args.rval().setString(cx->names().NegativeInfinity);
+        return true;
+    }
+
+    // Steps 5-9.
+    return DToStrResult(cx, Extract(args.thisv()), DTOSTR_FIXED, precision, args);
+}
+
+static bool
+num_toFixed(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toFixed_impl>(cx, args);
+}
+
+// ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.2.
+MOZ_ALWAYS_INLINE bool
+num_toExponential_impl(JSContext* cx, const CallArgs& args)
+{
+    // Step 1.
+    MOZ_ASSERT(IsNumber(args.thisv()));
+    double d = Extract(args.thisv());
+
+    // Step 2.
+    double prec = 0;
+    JSDToStrMode mode = DTOSTR_STANDARD_EXPONENTIAL;
+    if (args.hasDefined(0)) {
+        mode = DTOSTR_EXPONENTIAL;
+        if (!ToInteger(cx, args[0], &prec))
+            return false;
+    }
+
+    // Step 3.
+    MOZ_ASSERT_IF(!args.hasDefined(0), prec == 0);
+
+    // Step 4.
+    if (mozilla::IsNaN(d)) {
+        args.rval().setString(cx->names().NaN);
+        return true;
+    }
+
+    // Steps 5-7.
+    if (mozilla::IsInfinite(d)) {
+        if (d > 0) {
+            args.rval().setString(cx->names().Infinity);
+            return true;
+        }
+
+        args.rval().setString(cx->names().NegativeInfinity);
+        return true;
+    }
+
+    // Steps 5-6, 8-15.
+    int precision = 0;
+    if (mode == DTOSTR_EXPONENTIAL) {
+        if (!ComputePrecisionInRange(cx, 0, MAX_PRECISION, prec, &precision))
+            return false;
+    }
+
+    return DToStrResult(cx, d, mode, precision + 1, args);
+}
+
+static bool
+num_toExponential(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toExponential_impl>(cx, args);
+}
+
+// ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.5.
+MOZ_ALWAYS_INLINE bool
+num_toPrecision_impl(JSContext* cx, const CallArgs& args)
+{
+    // Step 1.
+    MOZ_ASSERT(IsNumber(args.thisv()));
+    double d = Extract(args.thisv());
+
+    // Step 2.
+    if (!args.hasDefined(0)) {
+        JSString* str = NumberToStringWithBase<CanGC>(cx, d, 10);
+        if (!str) {
+            JS_ReportOutOfMemory(cx);
+            return false;
+        }
+        args.rval().setString(str);
+        return true;
+    }
+
+    // Step 3.
+    double prec = 0;
+    if (!ToInteger(cx, args[0], &prec))
+        return false;
+
+    // Step 4.
+    if (mozilla::IsNaN(d)) {
+        args.rval().setString(cx->names().NaN);
+        return true;
+    }
+
+    // Steps 5-7.
+    if (mozilla::IsInfinite(d)) {
+        if (d > 0) {
+            args.rval().setString(cx->names().Infinity);
+            return true;
+        }
+
+        args.rval().setString(cx->names().NegativeInfinity);
+        return true;
+    }
+
+    // Steps 5-6, 8-14.
+    int precision = 0;
+    if (!ComputePrecisionInRange(cx, 1, MAX_PRECISION, prec, &precision))
+        return false;
+
+    return DToStrResult(cx, d, DTOSTR_PRECISION, precision, args);
+}
+
+static bool
+num_toPrecision(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsNumber, num_toPrecision_impl>(cx, args);
+}
+
+static const JSFunctionSpec number_methods[] = {
+#if JS_HAS_TOSOURCE
+    JS_FN(js_toSource_str,       num_toSource,          0, 0),
+#endif
+    JS_FN(js_toString_str,       num_toString,          1, 0),
+#if EXPOSE_INTL_API
+    JS_SELF_HOSTED_FN(js_toLocaleString_str, "Number_toLocaleString", 0,0),
+#else
+    JS_FN(js_toLocaleString_str, num_toLocaleString,     0,0),
+#endif
+    JS_FN(js_valueOf_str,        num_valueOf,           0, 0),
+    JS_FN("toFixed",             num_toFixed,           1, 0),
+    JS_FN("toExponential",       num_toExponential,     1, 0),
+    JS_FN("toPrecision",         num_toPrecision,       1, 0),
+    JS_FS_END
+};
+
+// ES6 draft ES6 15.7.3.12
+static bool
+Number_isInteger(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    if (args.length() < 1 || !args[0].isNumber()) {
+        args.rval().setBoolean(false);
+        return true;
+    }
+    Value val = args[0];
+    args.rval().setBoolean(val.isInt32() ||
+                           (mozilla::IsFinite(val.toDouble()) &&
+                            JS::ToInteger(val.toDouble()) == val.toDouble()));
+    return true;
+}
+
+
+static const JSFunctionSpec number_static_methods[] = {
+    JS_SELF_HOSTED_FN("isFinite", "Number_isFinite", 1,0),
+    JS_FN("isInteger", Number_isInteger, 1, 0),
+    JS_SELF_HOSTED_FN("isNaN", "Number_isNaN", 1,0),
+    JS_SELF_HOSTED_FN("isSafeInteger", "Number_isSafeInteger", 1,0),
+    JS_FS_END
+};
+
+
+/*
+ * Set the exception mask to mask all exceptions and set the FPU precision
+ * to 53 bit mantissa (64 bit doubles).
+ */
+void
+js::FIX_FPU()
+{
+#if (defined __GNUC__ && defined __i386__) || \
+    (defined __SUNPRO_CC && defined __i386)
+    short control;
+    asm("fstcw %0" : "=m" (control) : );
+    control &= ~0x300; // Lower bits 8 and 9 (precision control).
+    control |= 0x2f3;  // Raise bits 0-5 (exception masks) and 9 (64-bit precision).
+    asm("fldcw %0" : : "m" (control) );
+#endif
+}
+
+bool
+js::InitRuntimeNumberState(JSRuntime* rt)
+{
+    FIX_FPU();
+
+    // XXX If EXPOSE_INTL_API becomes true all the time at some point,
+    //     js::InitRuntimeNumberState is no longer fallible, and we should
+    //     change its return type.
+#if !EXPOSE_INTL_API
+    /* Copy locale-specific separators into the runtime strings. */
+    const char* thousandsSeparator;
+    const char* decimalPoint;
+    const char* grouping;
+#ifdef HAVE_LOCALECONV
+    struct lconv* locale = localeconv();
+    thousandsSeparator = locale->thousands_sep;
+    decimalPoint = locale->decimal_point;
+    grouping = locale->grouping;
+#else
+    thousandsSeparator = getenv("LOCALE_THOUSANDS_SEP");
+    decimalPoint = getenv("LOCALE_DECIMAL_POINT");
+    grouping = getenv("LOCALE_GROUPING");
+#endif
+    if (!thousandsSeparator)
+        thousandsSeparator = "'";
+    if (!decimalPoint)
+        decimalPoint = ".";
+    if (!grouping)
+        grouping = "\3\0";
+
+    /*
+     * We use single malloc to get the memory for all separator and grouping
+     * strings.
+     */
+    size_t thousandsSeparatorSize = strlen(thousandsSeparator) + 1;
+    size_t decimalPointSize = strlen(decimalPoint) + 1;
+    size_t groupingSize = strlen(grouping) + 1;
+
+    char* storage = js_pod_malloc<char>(thousandsSeparatorSize +
+                                        decimalPointSize +
+                                        groupingSize);
+    if (!storage)
+        return false;
+
+    js_memcpy(storage, thousandsSeparator, thousandsSeparatorSize);
+    rt->thousandsSeparator = storage;
+    storage += thousandsSeparatorSize;
+
+    js_memcpy(storage, decimalPoint, decimalPointSize);
+    rt->decimalSeparator = storage;
+    storage += decimalPointSize;
+
+    js_memcpy(storage, grouping, groupingSize);
+    rt->numGrouping = grouping;
+#endif /* !EXPOSE_INTL_API */
+    return true;
+}
+
+#if !EXPOSE_INTL_API
+void
+js::FinishRuntimeNumberState(JSRuntime* rt)
+{
+    /*
+     * The free also releases the memory for decimalSeparator and numGrouping
+     * strings.
+     */
+    char* storage = const_cast<char*>(rt->thousandsSeparator);
+    js_free(storage);
+}
+#endif
+
+JSObject*
+js::InitNumberClass(JSContext* cx, HandleObject obj)
+{
+    MOZ_ASSERT(obj->isNative());
+
+    /* XXX must do at least once per new thread, so do it per JSContext... */
+    FIX_FPU();
+
+    Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
+
+    RootedObject numberProto(cx, global->createBlankPrototype(cx, &NumberObject::class_));
+    if (!numberProto)
+        return nullptr;
+    numberProto->as<NumberObject>().setPrimitiveValue(0);
+
+    RootedFunction ctor(cx);
+    ctor = global->createConstructor(cx, Number, cx->names().Number, 1);
+    if (!ctor)
+        return nullptr;
+
+    if (!LinkConstructorAndPrototype(cx, ctor, numberProto))
+        return nullptr;
+
+    /*
+     * Our NaN must be one particular canonical value, because we rely on NaN
+     * encoding for our value representation.  See Value.h.
+     */
+    static JSConstDoubleSpec number_constants[] = {
+        {"NaN",               GenericNaN()               },
+        {"POSITIVE_INFINITY", mozilla::PositiveInfinity<double>() },
+        {"NEGATIVE_INFINITY", mozilla::NegativeInfinity<double>() },
+        {"MAX_VALUE",         1.7976931348623157E+308    },
+        {"MIN_VALUE",         MinNumberValue<double>()   },
+        /* ES6 (April 2014 draft) 20.1.2.6 */
+        {"MAX_SAFE_INTEGER",  9007199254740991           },
+        /* ES6 (April 2014 draft) 20.1.2.10 */
+        {"MIN_SAFE_INTEGER", -9007199254740991,          },
+        /* ES6 (May 2013 draft) 15.7.3.7 */
+        {"EPSILON", 2.2204460492503130808472633361816e-16},
+        {0,0}
+    };
+
+    /* Add numeric constants (MAX_VALUE, NaN, &c.) to the Number constructor. */
+    if (!JS_DefineConstDoubles(cx, ctor, number_constants))
+        return nullptr;
+
+    if (!DefinePropertiesAndFunctions(cx, ctor, nullptr, number_static_methods))
+        return nullptr;
+
+    if (!DefinePropertiesAndFunctions(cx, numberProto, nullptr, number_methods))
+        return nullptr;
+
+    if (!JS_DefineFunctions(cx, global, number_functions))
+        return nullptr;
+
+    /* Number.parseInt should be the same function object as global parseInt. */
+    RootedId parseIntId(cx, NameToId(cx->names().parseInt));
+    JSFunction* parseInt = DefineFunction(cx, global, parseIntId, num_parseInt, 2,
+                                          JSPROP_RESOLVING);
+    if (!parseInt)
+        return nullptr;
+    RootedValue parseIntValue(cx, ObjectValue(*parseInt));
+    if (!DefineProperty(cx, ctor, parseIntId, parseIntValue, nullptr, nullptr, 0))
+        return nullptr;
+
+    /* Number.parseFloat should be the same function object as global parseFloat. */
+    RootedId parseFloatId(cx, NameToId(cx->names().parseFloat));
+    JSFunction* parseFloat = DefineFunction(cx, global, parseFloatId, num_parseFloat, 1,
+                                            JSPROP_RESOLVING);
+    if (!parseFloat)
+        return nullptr;
+    RootedValue parseFloatValue(cx, ObjectValue(*parseFloat));
+    if (!DefineProperty(cx, ctor, parseFloatId, parseFloatValue, nullptr, nullptr, 0))
+        return nullptr;
+
+    RootedValue valueNaN(cx, cx->runtime()->NaNValue);
+    RootedValue valueInfinity(cx, cx->runtime()->positiveInfinityValue);
+
+    /* ES5 15.1.1.1, 15.1.1.2 */
+    if (!NativeDefineProperty(cx, global, cx->names().NaN, valueNaN, nullptr, nullptr,
+                              JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING) ||
+        !NativeDefineProperty(cx, global, cx->names().Infinity, valueInfinity, nullptr, nullptr,
+                              JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING))
+    {
+        return nullptr;
+    }
+
+    if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_Number, ctor, numberProto))
+        return nullptr;
+
+    return numberProto;
+}
+
+static char*
+FracNumberToCString(ExclusiveContext* cx, ToCStringBuf* cbuf, double d, int base = 10)
+{
+#ifdef DEBUG
+    {
+        int32_t _;
+        MOZ_ASSERT(!mozilla::NumberIsInt32(d, &_));
+    }
+#endif
+
+    char* numStr;
+    if (base == 10) {
+        /*
+         * This is V8's implementation of the algorithm described in the
+         * following paper:
+         *
+         *   Printing floating-point numbers quickly and accurately with integers.
+         *   Florian Loitsch, PLDI 2010.
+         */
+        const double_conversion::DoubleToStringConverter& converter
+            = double_conversion::DoubleToStringConverter::EcmaScriptConverter();
+        double_conversion::StringBuilder builder(cbuf->sbuf, cbuf->sbufSize);
+        converter.ToShortest(d, &builder);
+        numStr = builder.Finalize();
+    } else {
+        numStr = cbuf->dbuf = js_dtobasestr(cx->dtoaState(), base, d);
+    }
+    return numStr;
+}
+
+char*
+js::NumberToCString(JSContext* cx, ToCStringBuf* cbuf, double d, int base/* = 10*/)
+{
+    int32_t i;
+    size_t len;
+    return mozilla::NumberIsInt32(d, &i)
+           ? Int32ToCString(cbuf, i, &len, base)
+           : FracNumberToCString(cx, cbuf, d, base);
+}
+
+template <AllowGC allowGC>
+static JSString*
+NumberToStringWithBase(ExclusiveContext* cx, double d, int base)
+{
+    ToCStringBuf cbuf;
+    char* numStr;
+
+    /*
+     * Caller is responsible for error reporting. When called from trace,
+     * returning nullptr here will cause us to fall of trace and then retry
+     * from the interpreter (which will report the error).
+     */
+    if (base < 2 || base > 36)
+        return nullptr;
+
+    JSCompartment* comp = cx->compartment();
+
+    int32_t i;
+    if (mozilla::NumberIsInt32(d, &i)) {
+        if (base == 10 && StaticStrings::hasInt(i))
+            return cx->staticStrings().getInt(i);
+        if (unsigned(i) < unsigned(base)) {
+            if (i < 10)
+                return cx->staticStrings().getInt(i);
+            char16_t c = 'a' + i - 10;
+            MOZ_ASSERT(StaticStrings::hasUnit(c));
+            return cx->staticStrings().getUnit(c);
+        }
+
+        if (JSFlatString* str = comp->dtoaCache.lookup(base, d))
+            return str;
+
+        size_t len;
+        numStr = Int32ToCString(&cbuf, i, &len, base);
+        MOZ_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
+    } else {
+        if (JSFlatString* str = comp->dtoaCache.lookup(base, d))
+            return str;
+
+        numStr = FracNumberToCString(cx, &cbuf, d, base);
+        if (!numStr) {
+            ReportOutOfMemory(cx);
+            return nullptr;
+        }
+        MOZ_ASSERT_IF(base == 10,
+                      !cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
+        MOZ_ASSERT_IF(base != 10,
+                      cbuf.dbuf && cbuf.dbuf == numStr);
+    }
+
+    JSFlatString* s = NewStringCopyZ<allowGC>(cx, numStr);
+
+    comp->dtoaCache.cache(base, d, s);
+    return s;
+}
+
+template <AllowGC allowGC>
+JSString*
+js::NumberToString(ExclusiveContext* cx, double d)
+{
+    return NumberToStringWithBase<allowGC>(cx, d, 10);
+}
+
+template JSString*
+js::NumberToString<CanGC>(ExclusiveContext* cx, double d);
+
+template JSString*
+js::NumberToString<NoGC>(ExclusiveContext* cx, double d);
+
+JSAtom*
+js::NumberToAtom(ExclusiveContext* cx, double d)
+{
+    int32_t si;
+    if (mozilla::NumberIsInt32(d, &si))
+        return Int32ToAtom(cx, si);
+
+    if (JSFlatString* str = LookupDtoaCache(cx, d))
+        return AtomizeString(cx, str);
+
+    ToCStringBuf cbuf;
+    char* numStr = FracNumberToCString(cx, &cbuf, d);
+    if (!numStr) {
+        ReportOutOfMemory(cx);
+        return nullptr;
+    }
+    MOZ_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
+
+    size_t length = strlen(numStr);
+    JSAtom* atom = Atomize(cx, numStr, length);
+    if (!atom)
+        return nullptr;
+
+    CacheNumber(cx, d, atom);
+
+    return atom;
+}
+
+JSFlatString*
+js::NumberToString(JSContext* cx, double d)
+{
+    if (JSString* str = NumberToStringWithBase<CanGC>(cx, d, 10))
+        return &str->asFlat();
+    return nullptr;
+}
+
+JSFlatString*
+js::IndexToString(JSContext* cx, uint32_t index)
+{
+    if (StaticStrings::hasUint(index))
+        return cx->staticStrings().getUint(index);
+
+    JSCompartment* c = cx->compartment();
+    if (JSFlatString* str = c->dtoaCache.lookup(10, index))
+        return str;
+
+    Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1];
+    RangedPtr<Latin1Char> end(buffer + JSFatInlineString::MAX_LENGTH_LATIN1,
+                              buffer, JSFatInlineString::MAX_LENGTH_LATIN1 + 1);
+    *end = '\0';
+    RangedPtr<Latin1Char> start = BackfillIndexInCharBuffer(index, end);
+
+    mozilla::Range<const Latin1Char> chars(start.get(), end - start);
+    JSInlineString* str = NewInlineString<CanGC>(cx, chars);
+    if (!str)
+        return nullptr;
+
+    c->dtoaCache.cache(10, index, str);
+    return str;
+}
+
+bool JS_FASTCALL
+js::NumberValueToStringBuffer(JSContext* cx, const Value& v, StringBuffer& sb)
+{
+    /* Convert to C-string. */
+    ToCStringBuf cbuf;
+    const char* cstr;
+    size_t cstrlen;
+    if (v.isInt32()) {
+        cstr = Int32ToCString(&cbuf, v.toInt32(), &cstrlen);
+        MOZ_ASSERT(cstrlen == strlen(cstr));
+    } else {
+        cstr = NumberToCString(cx, &cbuf, v.toDouble());
+        if (!cstr) {
+            JS_ReportOutOfMemory(cx);
+            return false;
+        }
+        cstrlen = strlen(cstr);
+    }
+
+    /*
+     * Inflate to char16_t string.  The input C-string characters are < 127, so
+     * even if char16_t units are UTF-8, all chars should map to one char16_t.
+     */
+    MOZ_ASSERT(!cbuf.dbuf && cstrlen < cbuf.sbufSize);
+    return sb.append(cstr, cstrlen);
+}
+
+template <typename CharT>
+static bool
+CharsToNumber(ExclusiveContext* cx, const CharT* chars, size_t length, double* result)
+{
+    if (length == 1) {
+        CharT c = chars[0];
+        if ('0' <= c && c <= '9')
+            *result = c - '0';
+        else if (unicode::IsSpace(c))
+            *result = 0.0;
+        else
+            *result = GenericNaN();
+        return true;
+    }
+
+    const CharT* end = chars + length;
+    const CharT* bp = SkipSpace(chars, end);
+
+    /* ECMA doesn't allow signed non-decimal numbers (bug 273467). */
+    if (end - bp >= 2 && bp[0] == '0') {
+        int radix = 0;
+        if (bp[1] == 'b' || bp[1] == 'B')
+            radix = 2;
+        else if (bp[1] == 'o' || bp[1] == 'O')
+            radix = 8;
+        else if (bp[1] == 'x' || bp[1] == 'X')
+            radix = 16;
+
+        if (radix != 0) {
+            /*
+             * It's probably a non-decimal number. Accept if there's at least one digit after
+             * the 0b|0o|0x, and if no non-whitespace characters follow all the digits.
+             */
+            const CharT* endptr;
+            double d;
+            if (!GetPrefixInteger(cx, bp + 2, end, radix, &endptr, &d) ||
+                endptr == bp + 2 ||
+                SkipSpace(endptr, end) != end)
+            {
+                *result = GenericNaN();
+            } else {
+                *result = d;
+            }
+            return true;
+        }
+    }
+
+    /*
+     * Note that ECMA doesn't treat a string beginning with a '0' as
+     * an octal number here. This works because all such numbers will
+     * be interpreted as decimal by js_strtod.  Also, any hex numbers
+     * that have made it here (which can only be negative ones) will
+     * be treated as 0 without consuming the 'x' by js_strtod.
+     */
+    const CharT* ep;
+    double d;
+    if (!js_strtod(cx, bp, end, &ep, &d)) {
+        *result = GenericNaN();
+        return false;
+    }
+
+    if (SkipSpace(ep, end) != end)
+        *result = GenericNaN();
+    else
+        *result = d;
+
+    return true;
+}
+
+bool
+js::StringToNumber(ExclusiveContext* cx, JSString* str, double* result)
+{
+    AutoCheckCannotGC nogc;
+    JSLinearString* linearStr = str->ensureLinear(cx);
+    if (!linearStr)
+        return false;
+
+    return linearStr->hasLatin1Chars()
+           ? CharsToNumber(cx, linearStr->latin1Chars(nogc), str->length(), result)
+           : CharsToNumber(cx, linearStr->twoByteChars(nogc), str->length(), result);
+}
+
+bool
+js::ToNumberSlow(ExclusiveContext* cx, HandleValue v_, double* out)
+{
+    RootedValue v(cx, v_);
+    MOZ_ASSERT(!v.isNumber());
+
+    if (!v.isPrimitive()) {
+        if (!cx->isJSContext())
+            return false;
+
+        if (!ToPrimitive(cx->asJSContext(), JSTYPE_NUMBER, &v))
+            return false;
+
+        if (v.isNumber()) {
+            *out = v.toNumber();
+            return true;
+        }
+    }
+    if (v.isString())
+        return StringToNumber(cx, v.toString(), out);
+    if (v.isBoolean()) {
+        *out = v.toBoolean() ? 1.0 : 0.0;
+        return true;
+    }
+    if (v.isNull()) {
+        *out = 0.0;
+        return true;
+    }
+    if (v.isSymbol()) {
+        if (cx->isJSContext()) {
+            JS_ReportErrorNumberASCII(cx->asJSContext(), GetErrorMessage, nullptr,
+                                      JSMSG_SYMBOL_TO_NUMBER);
+        }
+        return false;
+    }
+
+    MOZ_ASSERT(v.isUndefined());
+    *out = GenericNaN();
+    return true;
+}
+
+JS_PUBLIC_API(bool)
+js::ToNumberSlow(JSContext* cx, HandleValue v, double* out)
+{
+    return ToNumberSlow(static_cast<ExclusiveContext*>(cx), v, out);
+}
+
+/*
+ * Convert a value to an int8_t, according to the WebIDL rules for byte
+ * conversion. Return converted value in *out on success, false on failure.
+ */
+JS_PUBLIC_API(bool)
+js::ToInt8Slow(JSContext *cx, const HandleValue v, int8_t *out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToInt8(d);
+    return true;
+}
+
+/*
+ * Convert a value to an uint8_t, according to the ToUInt8() function in ES6
+ * ECMA-262, 7.1.10. Return converted value in *out on success, false on failure.
+ */
+JS_PUBLIC_API(bool)
+js::ToUint8Slow(JSContext *cx, const HandleValue v, uint8_t *out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToInt8(d);
+    return true;
+}
+
+/*
+ * Convert a value to an int16_t, according to the WebIDL rules for short
+ * conversion. Return converted value in *out on success, false on failure.
+ */
+JS_PUBLIC_API(bool)
+js::ToInt16Slow(JSContext *cx, const HandleValue v, int16_t *out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToInt16(d);
+    return true;
+}
+
+/*
+ * Convert a value to an int64_t, according to the WebIDL rules for long long
+ * conversion. Return converted value in *out on success, false on failure.
+ */
+JS_PUBLIC_API(bool)
+js::ToInt64Slow(JSContext* cx, const HandleValue v, int64_t* out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToInt64(d);
+    return true;
+}
+
+/*
+ * Convert a value to an uint64_t, according to the WebIDL rules for unsigned long long
+ * conversion. Return converted value in *out on success, false on failure.
+ */
+JS_PUBLIC_API(bool)
+js::ToUint64Slow(JSContext* cx, const HandleValue v, uint64_t* out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToUint64(d);
+    return true;
+}
+
+JS_PUBLIC_API(bool)
+js::ToInt32Slow(JSContext* cx, const HandleValue v, int32_t* out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToInt32(d);
+    return true;
+}
+
+JS_PUBLIC_API(bool)
+js::ToUint32Slow(JSContext* cx, const HandleValue v, uint32_t* out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumberSlow(cx, v, &d))
+            return false;
+    }
+    *out = ToUint32(d);
+    return true;
+}
+
+JS_PUBLIC_API(bool)
+js::ToUint16Slow(JSContext* cx, const HandleValue v, uint16_t* out)
+{
+    MOZ_ASSERT(!v.isInt32());
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else if (!ToNumberSlow(cx, v, &d)) {
+        return false;
+    }
+
+    if (d == 0 || !mozilla::IsFinite(d)) {
+        *out = 0;
+        return true;
+    }
+
+    uint16_t u = (uint16_t) d;
+    if ((double)u == d) {
+        *out = u;
+        return true;
+    }
+
+    bool neg = (d < 0);
+    d = floor(neg ? -d : d);
+    d = neg ? -d : d;
+    unsigned m = JS_BIT(16);
+    d = fmod(d, (double) m);
+    if (d < 0)
+        d += m;
+    *out = (uint16_t) d;
+    return true;
+}
+
+template<typename T>
+bool
+js::ToLengthClamped(T* cx, HandleValue v, uint32_t* out, bool* overflow)
+{
+    if (v.isInt32()) {
+        int32_t i = v.toInt32();
+        *out = i < 0 ? 0 : i;
+        return true;
+    }
+    double d;
+    if (v.isDouble()) {
+        d = v.toDouble();
+    } else {
+        if (!ToNumber(cx, v, &d)) {
+            *overflow = false;
+            return false;
+        }
+    }
+    d = JS::ToInteger(d);
+    if (d <= 0.0) {
+        *out = 0;
+        return true;
+    }
+    if (d >= (double)0xFFFFFFFEU) {
+        *overflow = true;
+        return false;
+    }
+    *out = (uint32_t)d;
+    return true;
+}
+
+template bool
+js::ToLengthClamped<JSContext>(JSContext*, HandleValue, uint32_t*, bool*);
+template bool
+js::ToLengthClamped<ExclusiveContext>(ExclusiveContext*, HandleValue, uint32_t*, bool*);
+
+bool
+js::ToIntegerIndex(JSContext* cx, JS::HandleValue v, uint64_t* index)
+{
+    // Fast common case.
+    if (v.isInt32()) {
+        int32_t i = v.toInt32();
+        if (i >= 0) {
+            *index = i;
+            return true;
+        }
+    }
+
+    // Slow case. Use ToNumber() to coerce. This may throw a TypeError.
+    double d;
+    if (!ToNumber(cx, v, &d))
+        return false;
+
+    // Check that |d| is an integer in the valid range.
+    //
+    // Not all floating point integers fit in the range of a uint64_t, so we
+    // need a rough range check before the real range check in our caller. We
+    // could limit indexes to UINT64_MAX, but this would mean that our callers
+    // have to be very careful about integer overflow. The contiguous integer
+    // floating point numbers end at 2^53, so make that our upper limit. If we
+    // ever support arrays with more than 2^53 elements, this will need to
+    // change.
+    //
+    // Reject infinities, NaNs, and numbers outside the contiguous integer range
+    // with a RangeError.
+
+    // Write relation so NaNs throw a RangeError.
+    if (!(0 <= d && d <= (uint64_t(1) << 53))) {
+        JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_INDEX);
+        return false;
+    }
+
+    // Check that d is an integer, throw a RangeError if not.
+    // Note that this conversion could invoke undefined behaviour without the
+    // range check above.
+    uint64_t i(d);
+    if (d != double(i)) {
+        JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_INDEX);
+        return false;
+    }
+
+    *index = i;
+    return true;
+}
+
+template <typename CharT>
+bool
+js_strtod(ExclusiveContext* cx, const CharT* begin, const CharT* end, const CharT** dEnd,
+          double* d)
+{
+    const CharT* s = SkipSpace(begin, end);
+    size_t length = end - s;
+
+    Vector<char, 32> chars(cx);
+    if (!chars.growByUninitialized(length + 1))
+        return false;
+
+    size_t i = 0;
+    for (; i < length; i++) {
+        char16_t c = s[i];
+        if (c >> 8)
+            break;
+        chars[i] = char(c);
+    }
+    chars[i] = 0;
+
+    /* Try to parse +Infinity, -Infinity or Infinity. */
+    {
+        char* afterSign = chars.begin();
+        bool negative = (*afterSign == '-');
+        if (negative || *afterSign == '+')
+            afterSign++;
+
+        if (*afterSign == 'I' && !strncmp(afterSign, "Infinity", 8)) {
+            *d = negative ? NegativeInfinity<double>() : PositiveInfinity<double>();
+            *dEnd = s + (afterSign - chars.begin()) + 8;
+            return true;
+        }
+    }
+
+    /* Everything else. */
+    int err;
+    char* ep;
+    *d = js_strtod_harder(cx->dtoaState(), chars.begin(), &ep, &err);
+
+    MOZ_ASSERT(ep >= chars.begin());
+
+    if (ep == chars.begin())
+        *dEnd = begin;
+    else
+        *dEnd = s + (ep - chars.begin());
+
+    return true;
+}
+
+template bool
+js_strtod(ExclusiveContext* cx, const char16_t* begin, const char16_t* end, const char16_t** dEnd,
+          double* d);
+
+template bool
+js_strtod(ExclusiveContext* cx, const Latin1Char* begin, const Latin1Char* end,
+          const Latin1Char** dEnd, double* d);