The C51 can't support double(8-byte) variable. Does anyone know the third party liberary to support this function?
The 8051 is an 8-bit microcontroller; using 16-bit ints is generally best avoided - but now you want 8-byte floating point!!! :-0 Do you really think this is appropriate for an 8051? Do you really need floating point? Have you looked at fixed-point?
Again we see the '51 assumed to be a PC clone. Quoting Pete Seger "when will they ever learn?" Take a quick glance through the problems discussed here and observe how many are related to stubbornly refusing to accept that the '51 is a unique architecture that is excellent when used as intended and bloody awful when not. Erik