mirror of
https://github.com/Relintai/rcpp_framework.git
synced 2024-11-14 04:57:21 +01:00
79 lines
2.9 KiB
C
79 lines
2.9 KiB
C
|
// 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_
|