[llvm] [SLP]Model reduction_add(ext(<n x i1>)) as ext(ctpop(bitcast <n x i1> to int n)) (PR #116875)

[Philip Reames via llvm-commits]

preames wrote:

Why not use the existing getExtendedReductionCost and push the logic about the ctpop inside that?

https://github.com/llvm/llvm-project/pull/116875