[llvm-branch-commits] [llvm] release/23.x: [AArch64] Fix cost of vector shifts with non-uniform constants(#214206) (PR #215625)

[Hassnaa Hamdi via llvm-branch-commits]

hassnaaHamdi wrote:

> > I have been giving it a few days on trunk to see if there is any fallout. It does help fix the regression, and another issue in leela too. The performance changes are not universally positive and can cause regressions elsewhere though.
> 
> Do you have any idea how big is the performance regressions are that this change introduces, and how widespread they are?

This change improves the performance ~4% for imagick and ~3% for leela. These measures are for neoverse-v1/v2.

https://github.com/llvm/llvm-project/pull/215625