Re: [問題] 請問是否有浮點數轉二進制的函式(C)

==> [e-mail] (Avril Lavigne) 提到:
>         想請問是否有函式可以浮點數轉成32bit的
>         thx

Visual Studio 2005 以上的版本的指令,
僅供參考

typedef __int64 Int64;
//! Check if a number is infinite.
inline bool isInfinite(double A)
{
        // Representation of infinity for double precision number.
        static const Int64 _kInfAsInt = 0x7FF0000000000000;

        // An infinity has an exponent of 1023 (shift left 52 positions) and
        // a zero mantissa. There are two infinities - positive and negative.
        if ((*(Int64*)&A & 0x7FFFFFFFFFFFFFFF) == _kInfAsInt)
        {
                return true;
        }
        else
        {
                return false;
        }
}
//! Check if a number is Not-a-Number.
inline bool isNan(double A)
{       // A NAN has an exponent of 1023 (shifted left 52 positions) and
        // a non-zero mantissa. There are two Nan's - positive and negative.
        Int64 _exp      = *(Int64*)&A & 0x7FF0000000000000;
        Int64 _mantissa = *(Int64*)&A & 0x7FFFFFFFFFFFF;

        if(_exp == 0x7FF0000000000000 && _mantissa == 0)
        {
                return true;
        }
        else
        {
                return false;
        }
}
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