Restriction: The following information applies to native COBOL only.
In general, you can take a 32-bit program, recompile it with the P64 Compiler directive set, and it should run without problem as a 64-bit application. There are, however, certain circumstances in which the conversion of your program won't be as simple as this:
- If your program uses pointers
- You need to ensure that pointers are not redefined or modified by reference. There should also be no assumptions in your record definitions about the sizes of pointers.
- If your program uses a File Control Description (FCD) block that has been directly coded
- The program will have to be modified to use the 64-bit FCD3 format if the 32-bit program was using the older FCD2 format. 64-bit programs need an FCD control block that has a different format to that used by older 32-bit applications.
