blob: e0b5bcfa1075794d5c7677e41bbb920d1de07ff2 [file] [log] [blame]
/*
* Copyright (C) 2017 Caio Lima <ticaiolima@gmail.com>
* Copyright (C) 2019-2022 Apple 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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.
*/
#pragma once
#include "CPU.h"
#include "Error.h"
#include "ExceptionHelpers.h"
#include "JSGlobalObject.h"
#include "JSObject.h"
#include "MathCommon.h"
#include <wtf/CagedUniquePtr.h>
#include <wtf/Int128.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/StringView.h>
#include <wtf/text/WTFString.h>
namespace JSC {
class Int32BigIntImpl;
class HeapBigIntImpl;
class JSBigInt final : public JSCell {
public:
using Base = JSCell;
using Digit = UCPURegister;
static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal | OverridesToThis;
friend class CachedBigInt;
DECLARE_VISIT_CHILDREN;
template<typename CellType, SubspaceAccess>
static GCClient::IsoSubspace* subspaceFor(VM& vm)
{
return &vm.bigIntSpace();
}
enum class InitializationType { None, WithZero };
void initialize(InitializationType);
static size_t estimatedSize(JSCell*, VM&);
static Structure* createStructure(VM&, JSGlobalObject*, JSValue prototype);
JS_EXPORT_PRIVATE static JSBigInt* createZero(JSGlobalObject*);
JS_EXPORT_PRIVATE static JSBigInt* tryCreateZero(VM&);
JS_EXPORT_PRIVATE static JSBigInt* tryCreateWithLength(VM&, unsigned length);
JS_EXPORT_PRIVATE static JSBigInt* createWithLength(JSGlobalObject*, unsigned length);
JS_EXPORT_PRIVATE static JSBigInt* createFrom(JSGlobalObject*, int32_t value);
static JSBigInt* tryCreateFrom(VM&, int32_t value);
static JSBigInt* createFrom(JSGlobalObject*, uint32_t value);
JS_EXPORT_PRIVATE static JSBigInt* createFrom(JSGlobalObject*, int64_t value);
JS_EXPORT_PRIVATE static JSBigInt* createFrom(JSGlobalObject*, uint64_t value);
JS_EXPORT_PRIVATE static JSBigInt* createFrom(JSGlobalObject*, Int128 value);
static JSBigInt* createFrom(JSGlobalObject*, bool value);
static JSBigInt* createFrom(JSGlobalObject*, double value);
static JSBigInt* createFrom(JSGlobalObject*, VM&, int32_t value);
static size_t offsetOfLength()
{
return OBJECT_OFFSETOF(JSBigInt, m_length);
}
DECLARE_EXPORT_INFO;
JSValue toPrimitive(JSGlobalObject*, PreferredPrimitiveType) const;
void setSign(bool sign) { m_sign = sign; }
bool sign() const { return m_sign; }
unsigned length() const { return m_length; }
static JSValue makeHeapBigIntOrBigInt32(JSGlobalObject* globalObject, int64_t value)
{
#if USE(BIGINT32)
if (value <= INT_MAX && value >= INT_MIN)
return jsBigInt32(static_cast<int32_t>(value));
#endif
return JSBigInt::createFrom(globalObject, value);
}
static JSValue makeHeapBigIntOrBigInt32(JSGlobalObject* globalObject, uint64_t value)
{
#if USE(BIGINT32)
if (value <= INT_MAX)
return jsBigInt32(static_cast<int32_t>(value));
#endif
return JSBigInt::createFrom(globalObject, value);
}
static JSValue makeHeapBigIntOrBigInt32(JSGlobalObject* globalObject, double value)
{
ASSERT(isInteger(value));
if (std::abs(value) <= maxSafeInteger())
return makeHeapBigIntOrBigInt32(globalObject, static_cast<int64_t>(value));
return JSBigInt::createFrom(globalObject, value);
}
enum class ErrorParseMode {
ThrowExceptions,
IgnoreExceptions
};
enum class ParseIntMode { DisallowEmptyString, AllowEmptyString };
enum class ParseIntSign { Unsigned, Signed };
static JSValue parseInt(JSGlobalObject*, VM&, StringView, uint8_t radix, ErrorParseMode = ErrorParseMode::ThrowExceptions, ParseIntSign = ParseIntSign::Unsigned);
static JSValue parseInt(JSGlobalObject*, StringView, ErrorParseMode = ErrorParseMode::ThrowExceptions);
static JSValue stringToBigInt(JSGlobalObject*, StringView);
static String tryGetString(VM&, JSBigInt*, unsigned radix);
String toString(JSGlobalObject*, unsigned radix);
enum class ComparisonMode {
LessThan,
LessThanOrEqual
};
enum class ComparisonResult {
Equal,
Undefined,
GreaterThan,
LessThan
};
JS_EXPORT_PRIVATE static bool equals(JSBigInt*, JSBigInt*);
bool equalsToNumber(JSValue);
JS_EXPORT_PRIVATE bool equalsToInt32(int32_t);
static ComparisonResult compare(JSBigInt* x, JSBigInt* y);
static ComparisonResult compare(int32_t x, JSBigInt* y);
static ComparisonResult compare(JSBigInt* x, int32_t y);
static ComparisonResult compare(int32_t x, int32_t y)
{
if (x == y)
return JSBigInt::ComparisonResult::Equal;
if (x < y)
return JSBigInt::ComparisonResult::LessThan;
return JSBigInt::ComparisonResult::GreaterThan;
}
double toNumber(JSGlobalObject*) const;
JSObject* toObject(JSGlobalObject*) const;
inline bool toBoolean() const { return !isZero(); }
ComparisonResult static compareToDouble(JSBigInt* x, double y);
ALWAYS_INLINE static JSValue asInt32OrHeapCell(JSGlobalObject* globalObject, int64_t value)
{
#if USE(BIGINT32)
if (static_cast<int64_t>(static_cast<int32_t>(value)) == value)
return jsBigInt32(static_cast<int32_t>(value));
#endif
return createFrom(globalObject, value);
}
private:
friend class HeapBigIntImpl;
public:
struct ImplResult {
ImplResult(HeapBigIntImpl&);
ImplResult(JSBigInt*);
#if USE(BIGINT32)
ImplResult(Int32BigIntImpl&);
#endif
ImplResult(JSValue);
JSValue payload;
};
private:
static JSBigInt* createWithLength(JSGlobalObject*, VM&, unsigned length);
static JSBigInt* createZero(JSGlobalObject*, VM&);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult exponentiateImpl(JSGlobalObject*, BigIntImpl1 base, BigIntImpl2 exponent);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult multiplyImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl>
static ImplResult incImpl(JSGlobalObject*, BigIntImpl x);
template <typename BigIntImpl>
static ImplResult decImpl(JSGlobalObject*, BigIntImpl x);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult addImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult subImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult divideImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult remainderImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl>
static ImplResult unaryMinusImpl(JSGlobalObject*, BigIntImpl x);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult bitwiseAndImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult bitwiseOrImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult bitwiseXorImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl>
static ImplResult bitwiseNotImpl(JSGlobalObject*, BigIntImpl x);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult leftShiftImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult signedRightShiftImpl(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ComparisonResult compareImpl(BigIntImpl1 x, BigIntImpl2 y);
public:
static JSValue exponentiate(JSGlobalObject*, JSBigInt* base, JSBigInt* exponent);
#if USE(BIGINT32)
static JSValue exponentiate(JSGlobalObject*, JSBigInt* base, int32_t exponent);
static JSValue exponentiate(JSGlobalObject*, int32_t base, JSBigInt* exponent);
static JSValue exponentiate(JSGlobalObject*, int32_t base, int32_t exponent);
#endif
static JSValue multiply(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue multiply(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue multiply(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue multiply(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
int64_t result = static_cast<int64_t>(x) * static_cast<int64_t>(y);
return asInt32OrHeapCell(globalObject, result);
}
#endif
static JSValue inc(JSGlobalObject*, JSBigInt* x);
#if USE(BIGINT32)
static JSValue inc(JSGlobalObject* globalObject, int32_t x)
{
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) + 1);
}
#endif
static JSValue dec(JSGlobalObject*, JSBigInt* x);
#if USE(BIGINT32)
static JSValue dec(JSGlobalObject* globalObject, int32_t x)
{
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) - 1);
}
#endif
static JSValue add(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue add(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue add(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue add(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) + static_cast<int64_t>(y));
}
#endif
static JSValue sub(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue sub(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue sub(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue sub(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) - static_cast<int64_t>(y));
}
#endif
static JSValue divide(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue divide(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue divide(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue divide(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
if (!y) {
auto scope = DECLARE_THROW_SCOPE(getVM(globalObject));
throwRangeError(globalObject, scope, "0 is an invalid divisor value."_s);
return JSValue();
}
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) / static_cast<int64_t>(y));
}
#endif
static JSValue remainder(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue remainder(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue remainder(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue remainder(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
if (!y) {
auto scope = DECLARE_THROW_SCOPE(getVM(globalObject));
throwRangeError(globalObject, scope, "0 is an invalid divisor value."_s);
return JSValue();
}
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) % static_cast<int64_t>(y));
}
#endif
static JSValue unaryMinus(JSGlobalObject*, JSBigInt* x);
#if USE(BIGINT32)
static JSValue unaryMinus(JSGlobalObject* globalObject, int32_t x)
{
return asInt32OrHeapCell(globalObject, -static_cast<int64_t>(x));
}
#endif
static JSValue bitwiseAnd(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue bitwiseAnd(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue bitwiseAnd(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue bitwiseAnd(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
return asInt32OrHeapCell(globalObject, x & y);
}
#endif
static JSValue bitwiseOr(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue bitwiseOr(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue bitwiseOr(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue bitwiseOr(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
return asInt32OrHeapCell(globalObject, x | y);
}
#endif
static JSValue bitwiseXor(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue bitwiseXor(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue bitwiseXor(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue bitwiseXor(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
return asInt32OrHeapCell(globalObject, x ^ y);
}
#endif
static JSValue bitwiseNot(JSGlobalObject*, JSBigInt* x);
#if USE(BIGINT32)
static JSValue bitwiseNot(JSGlobalObject* globalObject, int32_t x)
{
return asInt32OrHeapCell(globalObject, ~x);
}
#endif
static JSValue leftShift(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue leftShift(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue leftShift(JSGlobalObject*, int32_t x, JSBigInt* y);
private:
static JSValue leftShiftSlow(JSGlobalObject*, int32_t x, int32_t y);
public:
static JSValue leftShift(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
if (y < 0) {
// Shifts one less than requested, but doesn't matter since lhs is int32
return signedRightShift(globalObject, x, y == INT32_MIN ? INT32_MAX : -y);
}
// Do some checks to detect overflow of left-shift. But this is much cheaper compared to allocating two JSBigInt and perform shift operations in JSBigInt.
if (!x)
return jsBigInt32(0);
if (y < 32)
return asInt32OrHeapCell(globalObject, static_cast<int64_t>(x) << y);
return leftShiftSlow(globalObject, x, y);
}
#endif
static JSValue signedRightShift(JSGlobalObject*, JSBigInt* x, JSBigInt* y);
#if USE(BIGINT32)
static JSValue signedRightShift(JSGlobalObject*, JSBigInt* x, int32_t y);
static JSValue signedRightShift(JSGlobalObject*, int32_t x, JSBigInt* y);
static JSValue signedRightShift(JSGlobalObject* globalObject, int32_t x, int32_t y)
{
if (y < 0) {
// Shifts one less than requested, but doesn't matter since lhs is int32
return leftShift(globalObject, x, y == INT32_MIN ? INT32_MAX : -y);
}
return jsBigInt32(x >> std::min(y, 31));
}
#endif
static JSValue toNumberHeap(JSBigInt*);
static JSValue toNumber(JSValue bigInt)
{
ASSERT(bigInt.isBigInt());
#if USE(BIGINT32)
if (bigInt.isBigInt32())
return jsNumber(bigInt.bigInt32AsInt32());
#endif
return toNumberHeap(jsCast<JSBigInt*>(bigInt));
}
static JSValue asIntN(JSGlobalObject*, uint64_t numberOfBits, JSBigInt*);
static JSValue asUintN(JSGlobalObject*, uint64_t numberOfBits, JSBigInt*);
#if USE(BIGINT32)
static JSValue asIntN(JSGlobalObject*, uint64_t numberOfBits, int32_t bigIntAsInt32);
static JSValue asUintN(JSGlobalObject*, uint64_t numberOfBits, int32_t bigIntAsInt32);
#endif
static uint64_t toBigUInt64(JSValue bigInt)
{
ASSERT(bigInt.isBigInt());
#if USE(BIGINT32)
if (bigInt.isBigInt32())
return static_cast<uint64_t>(static_cast<int64_t>(bigInt.bigInt32AsInt32()));
#endif
return toBigUInt64Heap(bigInt.asHeapBigInt());
}
static int64_t toBigInt64(JSValue bigInt)
{
ASSERT(bigInt.isBigInt());
#if USE(BIGINT32)
if (bigInt.isBigInt32())
return static_cast<int64_t>(bigInt.bigInt32AsInt32());
#endif
return static_cast<int64_t>(toBigUInt64Heap(bigInt.asHeapBigInt()));
}
Digit digit(unsigned);
void setDigit(unsigned, Digit); // Use only when initializing.
JS_EXPORT_PRIVATE JSBigInt* rightTrim(JSGlobalObject*);
JS_EXPORT_PRIVATE JSBigInt* tryRightTrim(VM&);
JS_EXPORT_PRIVATE std::optional<unsigned> concurrentHash();
unsigned hash()
{
if (m_hash)
return m_hash;
return hashSlow();
}
static std::optional<double> tryExtractDouble(JSValue);
private:
JSBigInt(VM&, Structure*, Digit*, unsigned length);
JSBigInt* rightTrim(JSGlobalObject*, VM&);
JS_EXPORT_PRIVATE unsigned hashSlow();
static JSBigInt* createFromImpl(JSGlobalObject*, uint64_t value, bool sign);
static constexpr unsigned bitsPerByte = 8;
static constexpr unsigned digitBits = sizeof(Digit) * bitsPerByte;
static constexpr unsigned halfDigitBits = digitBits / 2;
static constexpr Digit halfDigitMask = (1ull << halfDigitBits) - 1;
static constexpr int maxInt = 0x7FFFFFFF;
static constexpr unsigned doubleMantissaSize = 53;
static constexpr unsigned doublePhysicalMantissaSize = 52; // Excluding hidden-bit.
static constexpr uint64_t doublePhysicalMantissaMask = (1ULL << doublePhysicalMantissaSize) - 1;
static constexpr uint64_t doubleMantissaHiddenBit = 1ULL << doublePhysicalMantissaSize;
// The maximum length that the current implementation supports would be
// maxInt / digitBits. However, we use a lower limit for now, because
// raising it later is easier than lowering it.
// Support up to 1 million bits.
static constexpr unsigned maxLengthBits = 1024 * 1024;
static constexpr unsigned maxLength = maxLengthBits / digitBits;
static_assert(maxLengthBits % digitBits == 0);
static uint64_t calculateMaximumCharactersRequired(unsigned length, unsigned radix, Digit lastDigit, bool sign);
template <typename BigIntImpl1, typename BigIntImpl2>
static ComparisonResult absoluteCompare(BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl>
static bool absoluteDivWithDigitDivisor(JSGlobalObject*, VM&, BigIntImpl x, Digit divisor, JSBigInt** quotient, Digit& remainder);
template <typename BigIntImpl>
static void internalMultiplyAdd(BigIntImpl source, Digit factor, Digit summand, unsigned, JSBigInt* result);
template <typename BigIntImpl>
static void multiplyAccumulate(BigIntImpl multiplicand, Digit multiplier, JSBigInt* accumulator, unsigned accumulatorIndex);
template <typename BigIntImpl1>
static void absoluteDivWithBigIntDivisor(JSGlobalObject*, BigIntImpl1 dividend, JSBigInt* divisor, JSBigInt** quotient, JSBigInt** remainder);
enum class LeftShiftMode {
SameSizeResult,
AlwaysAddOneDigit
};
template <typename BigIntImpl>
static JSBigInt* absoluteLeftShiftAlwaysCopy(JSGlobalObject*, BigIntImpl x, unsigned shift, LeftShiftMode);
static bool productGreaterThan(Digit factor1, Digit factor2, Digit high, Digit low);
Digit absoluteInplaceAdd(JSBigInt* summand, unsigned startIndex);
Digit absoluteInplaceSub(JSBigInt* subtrahend, unsigned startIndex);
void inplaceRightShift(unsigned shift);
enum class RoundingResult {
RoundDown,
Tie,
RoundUp
};
static RoundingResult decideRounding(JSBigInt*, int32_t mantissaBitsUnset, int32_t digitIndex, uint64_t currentDigit);
enum class ExtraDigitsHandling {
Copy,
Skip
};
template<typename BigIntImpl1, typename BigIntImpl2, typename BitwiseOp>
static JSBigInt* absoluteBitwiseOp(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y, ExtraDigitsHandling, BitwiseOp&&);
template <typename BigIntImpl1, typename BigIntImpl2>
static JSBigInt* absoluteAnd(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static JSBigInt* absoluteOr(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static JSBigInt* absoluteAndNot(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static JSBigInt* absoluteXor(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
enum class SignOption {
Signed,
Unsigned
};
template <typename BigIntImpl>
static JSBigInt* absoluteAddOne(JSGlobalObject*, BigIntImpl x, SignOption);
template <typename BigIntImpl>
static JSBigInt* absoluteSubOne(JSGlobalObject*, BigIntImpl x, unsigned resultLength);
// Digit arithmetic helpers.
static Digit digitAdd(Digit a, Digit b, Digit& carry);
static Digit digitSub(Digit a, Digit b, Digit& borrow);
static Digit digitMul(Digit a, Digit b, Digit& high);
static Digit digitDiv(Digit high, Digit low, Digit divisor, Digit& remainder);
static Digit digitPow(Digit base, Digit exponent);
static String toStringBasePowerOfTwo(VM&, JSGlobalObject*, JSBigInt*, unsigned radix);
static String toStringGeneric(VM&, JSGlobalObject*, JSBigInt*, unsigned radix);
inline bool isZero() const
{
ASSERT(length() || !sign());
return length() == 0;
}
template <typename CharType>
static JSValue parseInt(JSGlobalObject*, CharType* data, unsigned length, ErrorParseMode);
template <typename CharType>
static JSValue parseInt(JSGlobalObject*, VM&, CharType* data, unsigned length, unsigned startIndex, unsigned radix, ErrorParseMode, ParseIntSign = ParseIntSign::Signed, ParseIntMode = ParseIntMode::AllowEmptyString);
static JSBigInt* allocateFor(JSGlobalObject*, VM&, unsigned radix, unsigned charcount);
template <typename BigIntImpl>
static JSBigInt* copy(JSGlobalObject*, BigIntImpl x);
void inplaceMultiplyAdd(Digit multiplier, Digit part);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult absoluteAdd(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y, bool resultSign);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult absoluteSub(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y, bool resultSign);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult leftShiftByAbsolute(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
template <typename BigIntImpl1, typename BigIntImpl2>
static ImplResult rightShiftByAbsolute(JSGlobalObject*, BigIntImpl1 x, BigIntImpl2 y);
static ImplResult rightShiftByMaximum(JSGlobalObject*, bool sign);
template <typename BigIntImpl>
static std::optional<Digit> toShiftAmount(BigIntImpl x);
template <typename BigIntImpl>
static ImplResult asIntNImpl(JSGlobalObject*, uint64_t, BigIntImpl);
template <typename BigIntImpl>
static ImplResult asUintNImpl(JSGlobalObject*, uint64_t, BigIntImpl);
template <typename BigIntImpl>
static ImplResult truncateToNBits(JSGlobalObject*, int32_t, BigIntImpl);
template <typename BigIntImpl>
static ImplResult truncateAndSubFromPowerOfTwo(JSGlobalObject*, int32_t, BigIntImpl, bool resultSign);
JS_EXPORT_PRIVATE static uint64_t toBigUInt64Heap(JSBigInt*);
inline static size_t offsetOfData()
{
return OBJECT_OFFSETOF(JSBigInt, m_data);
}
inline Digit* dataStorage() { return m_data.get(m_length); }
inline Digit* dataStorageUnsafe() { return m_data.getUnsafe(); }
const unsigned m_length;
unsigned m_hash { 0 };
bool m_sign { false };
CagedBarrierPtr<Gigacage::Primitive, Digit, tagCagedPtr> m_data;
};
inline JSBigInt* asHeapBigInt(JSValue value)
{
ASSERT(value.asCell()->isHeapBigInt());
return jsCast<JSBigInt*>(value.asCell());
}
inline JSBigInt::Digit JSBigInt::digit(unsigned n)
{
ASSERT(n < length());
return dataStorage()[n];
}
inline void JSBigInt::setDigit(unsigned n, Digit value)
{
ASSERT(n < length());
dataStorage()[n] = value;
}
ALWAYS_INLINE JSBigInt::ComparisonResult invertBigIntCompareResult(JSBigInt::ComparisonResult comparisonResult)
{
switch (comparisonResult) {
case JSBigInt::ComparisonResult::GreaterThan:
return JSBigInt::ComparisonResult::LessThan;
case JSBigInt::ComparisonResult::LessThan:
return JSBigInt::ComparisonResult::GreaterThan;
default:
return comparisonResult;
}
}
ALWAYS_INLINE JSValue tryConvertToBigInt32(JSBigInt* bigInt)
{
#if USE(BIGINT32)
if (UNLIKELY(!bigInt))
return JSValue();
if (bigInt->length() <= 1) {
if (!bigInt->length())
return jsBigInt32(0);
JSBigInt::Digit digit = bigInt->digit(0);
if (bigInt->sign()) {
static constexpr uint64_t maxValue = -static_cast<int64_t>(std::numeric_limits<int32_t>::min());
if (digit <= maxValue)
return jsBigInt32(static_cast<int32_t>(-static_cast<int64_t>(digit)));
} else {
static constexpr uint64_t maxValue = static_cast<uint64_t>(std::numeric_limits<int32_t>::max());
if (digit <= maxValue)
return jsBigInt32(static_cast<int32_t>(digit));
}
}
#endif
return bigInt;
}
ALWAYS_INLINE std::optional<double> JSBigInt::tryExtractDouble(JSValue value)
{
if (value.isNumber())
return value.asNumber();
if (!value.isBigInt())
return std::nullopt;
#if USE(BIGINT32)
if (value.isBigInt32())
return value.bigInt32AsInt32();
#endif
ASSERT(value.isHeapBigInt());
JSBigInt* bigInt = value.asHeapBigInt();
if (!bigInt->length())
return 0;
uint64_t integer = 0;
if constexpr (sizeof(Digit) == 8) {
if (bigInt->length() != 1)
return std::nullopt;
integer = bigInt->digit(0);
} else {
ASSERT(sizeof(Digit) == 4);
if (bigInt->length() > 2)
return std::nullopt;
integer = bigInt->digit(0);
if (bigInt->length() == 2)
integer |= (static_cast<uint64_t>(bigInt->digit(1)) << 32);
}
if (integer <= static_cast<uint64_t>(maxSafeInteger()))
return (bigInt->sign()) ? -static_cast<double>(integer) : static_cast<double>(integer);
return std::nullopt;
}
} // namespace JSC