Hi Eilert,
In the 2008 standard it says:
An implementation shall choose a representation for all floating-point types except for universal_real that conforms either to IEEE Std 754-1985 or to IEEE Std 854-1987; in either case, a minimum representation size of 64 bits is required for this chosen representation.
I think this changed before 2008, perhaps in 2002.
Best Regards,
Jim
