I would also like to know this. Fortran itself is column-major, so I would guess the internal layout isn't same for multi-dimensional arrays when compared to row-major C? I'm not sure how LFortran represents arrays internally though.

LFortran internally uses column-major, so interchanging data with C should be done carefully for multi-dimensional arrays. If row-major representation is highly needed feature, We can introduce a flag to do that. I'm not totally sure about that but it's doable under some conditions for sure.