[llvm] [VectorCombine] foldShuffleToIdentity - handle bitcasts with equal element counts (PR #97731)

[David Green via llvm-commits]

davemgreen wrote:

It seems to be this case, which is not reduced: https://godbolt.org/z/xxMoM37oj

I haven't analyzed very much, but it might need to check that each of the bitcasts is the same size/type, not just the first.

https://github.com/llvm/llvm-project/pull/97731