32 → 64-bit migration
Lifting production Fortran codebases from 32-bit to modern 64-bit architectures.
Categories:
Moving a real Fortran ERP from 32-bit to 64-bit is rarely a recompile. Pointer sizes, integer kinds, file formats, third-party libraries, and decades of implicit assumptions all have to be found and fixed without breaking business logic that has been correct for thirty years.
We have done this on a production ERP — see Projects → Profitool — and we know what to look for.
Where we add value
- Auditing the codebase for 32-bit assumptions: integer kinds, pointer arithmetic, record sizes, common blocks, EQUIVALENCE.
- Driving the translation with Promula / gmFortran and hand-tuned changes where the tool can’t decide.
- Locking the result with tests so the 64-bit build provably matches the 32-bit one before you cut over — see Expertise → Testing.
- Operational cutover: data file formats, on-disk layouts, third-party library upgrades, and rollback plans.