llvm-project

5aae014e - [LV] Refine tripcount estimate using minimum iteration count rt check. (#188135)

[LV] Refine tripcount estimate using minimum iteration count rt check. (#188135) When not folding the tail the minimum iteration count check ensures that the vector loop is not executed if computing the trip count wraps around to zero, as the trip count must be at least VF when vectorizing without tail-folding. Add and use a new tryToRefineConstantMaxTripCount helper. This ensures we do not create dead main loops when vectorizing the epilogue, as we choose smaller main VFs. PR: https://github.com/llvm/llvm-project/pull/188135