Folds G_LSHR + G_SHUFFLEVECTOR away when the shift amount
is 1/2 of the destination scalar size, and the mask starts with 1.
Depends on D134870.
Pierre-vh on Sep 26 2022, 3:55 AM.Authored by
Another thing worth thinking about is whether we should really be using legal vector_shuffle at all. The DAG path doesn't use it. Given that we have such a restricted set of shuffles (only 0, 1), it may still make sense to keep lowering to simple BUILD_VECTORs with 2 elements