You need to follow these recommendations when writing C and C++ code to call functions written in Fortran:
- Avoid using uppercase letters in identifiers. Although XL Fortran
folds external identifiers to lowercase by default, the Fortran compiler
can be set to distinguish external names by case.
- Avoid using long identifier names. The maximum number of significant
characters in XL Fortran identifiers is 2501.
Note: - The Fortran 90 and 95 language standards require identifiers to
be no more than 31 characters; the Fortran 2003 standard requires
identifiers to be no more than 63 characters.