I migrated a code from (vs 2008+Intel11.1) to (vs 2017+Parallel Studio 18). But I don't obtain the same result after calculations, the new result is wrong. The code contains .f90 files and also .f files. Do I need to change something in .f files ? Are there any changes to be made after this migration? Thank you !
You need to look carefully at the optimisations in use for both versions. This will change results.
You should also look for uninitialized variables, where you may have assumed that these were zero. All variables should be explicitly initialized if needed before they are used.
Also, you need to review the methods you are using in the calculations, as to whether they are well conditioned, or whether errors can propagate through your calculations.