[llvm] [SLP]Improve reordering for consts, splats and ops from same nodes + improved analysis. (PR #87091)

[Elvina Yakubova via llvm-commits]

ElvinaYakubova wrote:

> I will check, probably some corner case analysis, thanks.

That's exactly the reason why I asked about the Score check above. Without this, there are fewer shuffles generated. Could the problem be fixed with shiffles cost model tuning as well?

https://github.com/llvm/llvm-project/pull/87091