[llvm] [LLVM][AArch64]Use load/store with consecutive registers in SME2 or S… (PR #77665)

[Sander de Smalen via llvm-commits]

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@@ -3065,19 +3071,38 @@ bool AArch64FrameLowering::spillCalleeSavedRegisters(
       std::swap(Reg1, Reg2);
       std::swap(FrameIdxReg1, FrameIdxReg2);
     }
+
+    unsigned PairRegs;
+    unsigned PnReg;
+    if (RPI.isPaired() && RPI.isScalable()) {
+      PairRegs = AArch64::Z0_Z1 + (RPI.Reg1 - AArch64::Z0);
+      if (!PtrueCreated) {
+        PtrueCreated = true;
+        PnReg = AArch64::PN8;
+        BuildMI(MBB, MI, DL, TII.get(AArch64::PTRUE_C_B), PnReg)
+            .setMIFlags(MachineInstr::FrameSetup);
+      }
+    }
+
     MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, TII.get(StrOpc));
     if (!MRI.isReserved(Reg1))
       MBB.addLiveIn(Reg1);
     if (RPI.isPaired()) {
       if (!MRI.isReserved(Reg2))
         MBB.addLiveIn(Reg2);
-      MIB.addReg(Reg2, getPrologueDeath(MF, Reg2));
+      if (RPI.isScalable())
+        MIB.addReg(PairRegs);
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sdesmalen-arm wrote:

Should PairRegs also use `getPrologueDeath` ?

https://github.com/llvm/llvm-project/pull/77665