[llvm] Use ScaledThreshold to calculate Unroll count (PR #162247)

[Brian Cain via llvm-commits]

androm3da wrote:

> but for small loops it is giving more unroll count which is degrading the performance.Using Scaled Threshold improves the performance.

OBTW I've never made any real codegen changes but for the community's sake you should probably disclose the benchmark you are using here, and perhaps any other benchmarks that you think have at least neutral impact (to avoid performance regressions caused by this change).

https://github.com/llvm/llvm-project/pull/162247