//| <include file='doc\BinaryReader.uex' path='docs/doc[@for="BinaryReader.ReadDouble"]/*' />
public virtual double ReadDouble()
{
FillBuffer(8);
uint lo = (uint)(m_buffer[0] | (m_buffer[1]) << 8 |
(m_buffer[2]) << 16 | m_buffer[3] << 24);
uint hi = (uint)(m_buffer[4] | (m_buffer[5]) << 8 |
(m_buffer[6]) << 16 | m_buffer[7] << 24);
return(BitConverter.UInt64BitsToDouble(((ulong)hi) << 32 | lo));
}
public static void DoubleToUInt64Bits()
{
double input = 123456.3234;
ulong result = BitConverter.DoubleToUInt64Bits(input);
Assert.Equal(4683220267154373240UL, result);
double roundtripped = BitConverter.UInt64BitsToDouble(result);
Assert.Equal(input, roundtripped);
}
private void TestRoundTripDouble(ulong bits)
{
double d = BitConverter.UInt64BitsToDouble(bits);
if (double.IsFinite(d))
{
string s = InvariantToStringDouble(d);
CheckOneDouble(s, bits);
}
}
public static Double ToFloat(this UInt64 bits)
{
#if BITWISE_FLOAT_CONVERSION
return(BitConverter.UInt64BitsToDouble(bits));
#else
unsafe
{
return(*(Double *)&bits);
}
#endif
}
public static double GetDoubleFromParts(int sign, int exp, ulong man)
{
ulong bits;
if (man == 0)
{
bits = 0;
}
else
{
// Normalize so that 0x0010 0000 0000 0000 is the highest bit set.
int cbitShift = BitOperations.LeadingZeroCount(man) - 11;
if (cbitShift < 0)
{
man >>= -cbitShift;
}
else
{
man <<= cbitShift;
}
exp -= cbitShift;
Debug.Assert((man & 0xFFF0000000000000) == 0x0010000000000000);
// Move the point to just behind the leading 1: 0x001.0 0000 0000 0000
// (52 bits) and skew the exponent (by 0x3FF == 1023).
exp += 1075;
if (exp >= 0x7FF)
{
// Infinity.
bits = 0x7FF0000000000000;
}
else if (exp <= 0)
{
// Denormalized.
exp--;
if (exp < -52)
{
// Underflow to zero.
bits = 0;
}
else
{
bits = man >> -exp;
Debug.Assert(bits != 0);
}
}
else
{
// Mask off the implicit high bit.
bits = (man & 0x000FFFFFFFFFFFFF) | ((ulong)exp << 52);
}
}
if (sign < 0)
{
bits |= 0x8000000000000000;
}
return(BitConverter.UInt64BitsToDouble(bits));
}
private void CheckOneDouble(string s, ulong expectedBits)
{
CheckOneDouble(s, BitConverter.UInt64BitsToDouble(expectedBits));
}
