new packfloat

float pack_float_bits(const float v, const int r)
{
  union {
    float f;
    struct { unsigned value:31, sign:1; } vbits;
    struct { unsigned value:29, realm:2, sign:1; } rbits;
  } a;

  a.f = v;
  a.rbits.value = a.vbits.value >> 2;
  a.rbits.realm = r;

  return a.f;
}