llvm-project

7e054c33 - [VectorCombine] foldShuffleOfCastops - don't restrict to oneuse but compare total costs instead

[VectorCombine] foldShuffleOfCastops - don't restrict to oneuse but compare total costs instead Some casts (especially bitcasts but others as well) are incredibly cheap (or free), so don't limit the shuffle(cast(x),cast(y)) -> cast(shuffle(x,y)) to oneuse cases, but instead compare the total before/after costs of possibly repeating some casts.