[llvm] [LV][NFC] Simplify initialization of MinProfitableTripCount (PR #113445)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

> On the surface the change seems fine. Do you have any examples of where this would be useful?

We encountered a case where vectorization requires a lot of overflow checks, resulting in the need for a higher trip count for vectorization to be profitable. We hope to emit a profitable check for such cases when MinProfitableTripCount is not zero, in order to reduce unprofitable vectorized code be executed.

https://github.com/llvm/llvm-project/pull/113445