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.
- A File Control Description (FCD) block that has been directly coded, the program will have to be modified to use the 64-bit FCD format. 64-bit programs need an FCD control block that has a different format to that used by 32-bit applications. See the chapter File Handler API in your File Handling book for details on the FCD. See the section File and FCD Handling below for information on the FCDs supported by different versions of Micro Focus COBOL systems.
