informix ESQL/C API changes for 64-bit SDK

We just migrate to Informix ESQL/C 9.20.FC1 from ESQL/C 7.12.UC1 on a Digital Alpha Unix V4.0. The version of SDK we got was 64-bit version. For this 64-bit version of SDK 2.20 the internal date representation and has been implemented as an "int" rather than "long". The sqlca.sqlcode was defined as "int" rather than "long", the interface of library functions handling dates changed respectively. According to the release notes we have to change source code to reflect these changes. Actually we got funny results if we leave the host variables for dates as "long". The work involved to identify all spots to be changed across the whole system and actually change and test them is not trivial. Does anybody have previous experience of doing this work? Any shortcuts, precautions? Any of your help is greatly appreciated! Carl Y. Wu