Thanks, didn't know this one! Have some reading to do. For a library that implements just the two component version of this, commonly known as a double-double,

Thanks, didn't know this one! Have some reading to do. For a library that implements just the two component version of this, commonly known as a double-double, for a mantissa of 107 bits and an exponent of 11, see: https://github.com/ncruces/dbldbl https://github.com/ncruces/dbldbl