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

[Sebastian Pop via llvm-commits]

sebpop wrote:

Hi Alexey, with this change we are seeing more shuffles created by SLP.
On a small testcase from TSVC https://godbolt.org/z/cb9YYbfY9 there are 5 more shffules compared to before the change.
Could you please check how to improve the code produced by SLP vectorizer on this testcase?

Thank you,
Sebastian


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