Log() [2/2]

static double System.Numerics.BigInteger.Log ( BigInteger value, double baseValue )

inlinestatic

Definition at line 711 of file BigInteger.cs.

    {
        if (value._sign < 0 || baseValue == 1.0)
        {
            return double.NaN;
        }
        if (baseValue == double.PositiveInfinity)
        {
            if (!value.IsOne)
            {
                return double.NaN;
            }
            return 0.0;
        }
        if (baseValue == 0.0 && !value.IsOne)
        {
            return double.NaN;
        }
        if (value._bits == null)
        {
            return Math.Log(value._sign, baseValue);
        }
        ulong num = value._bits[value._bits.Length - 1];
        ulong num2 = ((value._bits.Length > 1) ? value._bits[value._bits.Length - 2] : 0u);
        ulong num3 = ((value._bits.Length > 2) ? value._bits[value._bits.Length - 3] : 0u);
        int num4 = NumericsHelpers.CbitHighZero((uint)num);
        long num5 = (long)value._bits.Length * 32L - num4;
        ulong num6 = (num << 32 + num4) | (num2 << num4) | (num3 >> 32 - num4);
        return Math.Log(num6, baseValue) + (double)(num5 - 64) / Math.Log(baseValue, 2.0);
    }

References System.Numerics.NumericsHelpers.CbitHighZero(), System.L, System.Math.Log(), and System.value.