llvm-project

57d4c90d - [AArch64][SME] Propagate desired ZA states in the MachineSMEABIPass (#149510)

[AArch64][SME] Propagate desired ZA states in the MachineSMEABIPass (#149510) This patch adds a step to the MachineSMEABIPass that propagates desired ZA states. This aims to pick better ZA states for edge bundles, as when many (or all) blocks in a bundle do not have a preferred ZA state, the ZA state assigned to a bundle can be less than ideal. An important case is nested loops, where only the inner loop has a preferred ZA state. Here we'd like to propagate the ZA state from the inner loop to the outer loops (to avoid saves/restores in any loop).