public static double floor(double x)
{
Float64 u = x;
ref var p = ref u.x11;
/// <summary>
/// Computes y = x*2^i
/// </summary>
/// <param name="x"></param>
/// <param name="pw2"></param>
public static double ldexp(double x, int pw2)
{
Float64 u = x;
ref var q = ref u.x11;
public static double fabs(double x) => Float64.From(x).Abs();
/// <summary>
/// Extracts the exponent from x; Returns an integer power of two to
/// expnt and the significand between 0.5 and 1 to y.
/// Thus x = y * 2**expn.
/// </summary>
/// <param name="x"></param>
/// <param name="pw2"></param>
/// <returns></returns>
public static double frexp(double x, ref int pw2)
{
Float64 u = x;
int k;
ref var q = ref u.x11;