In previous releases of Quintus Prolog, floating-point numbers had less precision than single-precision floats in other languages. The result was a loss of precision when floats were passed between Prolog and foreign functions. In release 3 and later releases of Quintus Prolog the precision of floating-point numbers has been raised to 64 bits (double precision); hence, these errors no longer occur.
Quintus Prolog release 3 also supports the passing of floating point numbers explicitly as doubles or singles.