| // Copyright (C) 2011 Milo Yip |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| #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(); |
| } |
| |
| double PreviousPositiveDouble() const { |
| RAPIDJSON_ASSERT(!Sign()); |
| if (d == 0.0) |
| return 0.0; |
| else |
| return Double(u - 1).Value(); |
| } |
| |
| bool Sign() const { return (u & kSignMask) != 0; } |
| uint64_t Significand() const { return u & kSignificandMask; } |
| int Exponent() const { return ((u & kExponentMask) >> kSignificandSize) - kExponentBias; } |
| |
| bool IsNan() const { return (u & kExponentMask) == kExponentMask && Significand() != 0; } |
| bool IsInf() const { return (u & kExponentMask) == kExponentMask && Significand() == 0; } |
| bool IsNormal() const { return (u & kExponentMask) != 0 || Significand() == 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 unsigned 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_ |