As preparation for LoopInterchange becoming a loop pass, it needs to
preserve ScalarEvolution. Even though interchanging should not change
the trip count of the loop, it modifies loop entry, latch and exit
blocks.
I added -verify-scev to some loop interchange tests, but the verification does
not catch problems caused by missing invalidation of SE in loop interchange, as
the trip counts themselves do not change. So there might be potential to
make the SE verification covering more stuff in the future.
Reviewers: mkazantsev, efriedma, karthikthecool
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D52026
llvm-svn: 342209
3afb974aa5