llvm-project

555d8a58 - [AArch64] Reorganise perfect shuffle generation. NFC (#224526)

[AArch64] Reorganise perfect shuffle generation. NFC (#224526) This adds a generatePerfectShuffle implementation for parsing through the perfect shuffle tables, generating a list of ShuffleEntry's that represent the sequence of shuffles that need to be performed. This is intended to be a NFC as-is, allowing it to be reused in global isel and extended in the future to handle shuffles that are not part of the shuffle table. The number of instructions generated can also be used for costing shuffles, as we do for immediate generation.