[llvm] [AArch64] Separate PNR into its own Register Class (PR #65306)

[Matthew Devereau via llvm-commits]

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@@ -3993,6 +4000,10 @@ void AArch64InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     } else if (AArch64::PNRRegClass.hasSubClassEq(RC)) {
       assert((Subtarget.hasSVE2p1() || Subtarget.hasSME2()) &&
              "Unexpected register store without SVE2p1 or SME2");
+      if (SrcReg != AArch64::SP) {
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MDevereau wrote:

I saw it done elsewhere in this function and wanted to be conservative, but yes, it is pointless. Removed.

https://github.com/llvm/llvm-project/pull/65306