[llvm] [AArch64] Combine getActiveLaneMask with vector_extract (PR #81139)

[David Sherwood via llvm-commits]

================
@@ -1873,8 +1873,8 @@ void AArch64TargetLowering::addTypeForNEON(MVT VT) {
 
 bool AArch64TargetLowering::shouldExpandGetActiveLaneMask(EVT ResVT,
                                                           EVT OpVT) const {
-  // Only SVE has a 1:1 mapping from intrinsic -> instruction (whilelo).
-  if (!Subtarget->hasSVE())
+  // Only SVE/SME has a 1:1 mapping from intrinsic -> instruction (whilelo).
+  if (!Subtarget->hasSVEorSME())
----------------
david-arm wrote:

Can you revert this change for now due to a missing capability in the backend? Basically, the SME feature doesn't necessarily imply that SVE is always available. You could add a TODO here that we should also enable this for SME with SVE.

https://github.com/llvm/llvm-project/pull/81139