[llvm] [DA] Check monotonicity for subscripts (PR #154527)

[Sebastian Pop via llvm-commits]

sebpop wrote:

Two points:
- monotonicity checker belongs to ScalarEvolution.[h|cpp] (there's nothing specific to DA.)
- monotonic checker is redundant with SCEV's existing range analysis.

Instead of a separate monotonicity checker, enhance SCEV's existing getRange() methods to detect wrapping more accurately and integrate this into the existing DA wrapping checks.

https://github.com/llvm/llvm-project/pull/154527