[llvm] [SCEV] Rewrite some SCEVAdd sub-expressions using loop guards. (PR #156013)

[Florian Hahn via llvm-commits]

fhahn wrote:

Compile-time is neutral: https://llvm-compile-time-tracker.com/compare.php?from=3a9f80372b6f64e45145ed3497f7a6612d14049d&to=fb79c0af9b0c916edb3012ec8f8901f78f6c0014&stat=instructions:u

https://github.com/llvm/llvm-project/pull/156013