SCEV - Non liner induction variable Addrec expression


We are students at the Carnegie Mellon university.
We are currently working on a project which needs non linear IV's and their
corresponding increments.

We tried decoding their ADDRecExpr and found ourselves in a puzzle.

so basically we want to use the ADDRec expression(e.g. {k,+,l,+,n,+,m},
k,l,n,m being constants) to compute the increments of the
non linear IV's(e.g. j += A*i*I + B*I + c ), without requiring further
details about I (also an induction variable), A, B and C are constants.

we were hoping if someone has some documentation or already know how to do

Hoping for a reply soon.