Anyone know of an open-source 96 or 128 bit floating point C++ library? (Or even better, a specifiable but fixed bit library?)

I have seen and used apfloat, but the one thing I don't like about it is that apfloat numbers extend its precision with certain operations -- meaning that I have to continually go back an tell it I only need n significant digits.

What I'm trying to say is that I'm looking for something like:

class Float96;
class Float128;

or:

template<size_t bits>
class NBitFloat
{
//...
};

Thanks guys!

- Kevin