The @4 is a suffix added to routines called with the STDCALL interface to indicate that four bytes of argument list were passed. But more to the point is that you shouldn't be getting these at all. My guess is that you also got compile-time warnings about arguments to an intrinsic not matching, thus the compiler considered these to be external calls. You probably are passing single-precision arguments to IDINT and DLOG10 instead of double-precision. Try using just AINT and LOG10 as the intrinsic names instead - these are generic.