// Tencent is pleased to support the open source community by making RapidJSON available. // // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. // // Licensed under the MIT License (the "License"); you may not use this file except // in compliance with the License. You may obtain a copy of the License at // // http://opensource.org/licenses/MIT // // Unless required by applicable law or agreed to in writing, software distributed // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR // CONDITIONS OF ANY KIND, either express or implied. See the License for the // specific language governing permissions and limitations under the License. #ifndef RAPIDJSON_IEEE754_ #define RAPIDJSON_IEEE754_ #include "../rapidjson.h" RAPIDJSON_NAMESPACE_BEGIN namespace internal { class Double { public: Double() {} Double(double d) : d_(d) {} Double(uint64_t u) : u_(u) {} double Value() const { return d_; } uint64_t Uint64Value() const { return u_; } double NextPositiveDouble() const { RAPIDJSON_ASSERT(!Sign()); return Double(u_ + 1).Value(); } bool Sign() const { return (u_ & kSignMask) != 0; } uint64_t Significand() const { return u_ & kSignificandMask; } int Exponent() const { return static_cast<int>(((u_ & kExponentMask) >> kSignificandSize) - kExponentBias); } bool IsNan() const { return (u_ & kExponentMask) == kExponentMask && Significand() != 0; } bool IsInf() const { return (u_ & kExponentMask) == kExponentMask && Significand() == 0; } bool IsNanOrInf() const { return (u_ & kExponentMask) == kExponentMask; } bool IsNormal() const { return (u_ & kExponentMask) != 0 || Significand() == 0; } bool IsZero() const { return (u_ & (kExponentMask | kSignificandMask)) == 0; } uint64_t IntegerSignificand() const { return IsNormal() ? Significand() | kHiddenBit : Significand(); } int IntegerExponent() const { return (IsNormal() ? Exponent() : kDenormalExponent) - kSignificandSize; } uint64_t ToBias() const { return (u_ & kSignMask) ? ~u_ + 1 : u_ | kSignMask; } static int EffectiveSignificandSize(int order) { if (order >= -1021) return 53; else if (order <= -1074) return 0; else return order + 1074; } private: static const int kSignificandSize = 52; static const int kExponentBias = 0x3FF; static const int kDenormalExponent = 1 - kExponentBias; static const uint64_t kSignMask = RAPIDJSON_UINT64_C2(0x80000000, 0x00000000); static const uint64_t kExponentMask = RAPIDJSON_UINT64_C2(0x7FF00000, 0x00000000); static const uint64_t kSignificandMask = RAPIDJSON_UINT64_C2(0x000FFFFF, 0xFFFFFFFF); static const uint64_t kHiddenBit = RAPIDJSON_UINT64_C2(0x00100000, 0x00000000); union { double d_; uint64_t u_; }; }; } // namespace internal RAPIDJSON_NAMESPACE_END #endif // RAPIDJSON_IEEE754_