...apples and oranges.... R doesn't support non IEEE standard floats, what you are basically doing is using an external library (GMP), and special functions for

...apples and oranges.... R doesn't support non IEEE standard floats, what you are basically doing is using an external library (GMP), and special functions for addition, multiplication from that package. Nor can any of the functions in R "base" use GMP. Again, nobody is fudging numbers, neither R, Java, C, or JS because floating point is implemented on hardware so this argumument is a moot one.