1 files changed, 38 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index c4b43e1..c52487a 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -176,6 +176,9 @@ public:
                              std::optional<AArch64PACKey::ID> PACKey,
                              uint64_t PACDisc, Register PACAddrDisc);
 
+  // Emit the sequence for PAC.
+  void emitPtrauthSign(const MachineInstr *MI);
+
   // Emit the sequence to compute the discriminator.
   //
   // The returned register is either unmodified AddrDisc or ScratchReg.
@@ -2175,6 +2178,37 @@ void AArch64AsmPrinter::emitPtrauthAuthResign(
     OutStreamer->emitLabel(EndSym);
 }
 
+void AArch64AsmPrinter::emitPtrauthSign(const MachineInstr *MI) {
+  Register Val = MI->getOperand(1).getReg();
+  auto Key = (AArch64PACKey::ID)MI->getOperand(2).getImm();
+  uint64_t Disc = MI->getOperand(3).getImm();
+  Register AddrDisc = MI->getOperand(4).getReg();
+  bool AddrDiscKilled = MI->getOperand(4).isKill();
+
+  // As long as at least one of Val and AddrDisc is in GPR64noip, a scratch
+  // register is available.
+  Register ScratchReg = Val == AArch64::X16 ? AArch64::X17 : AArch64::X16;
+  assert(ScratchReg != AddrDisc &&
+         "Neither X16 nor X17 is available as a scratch register");
+
+  // Compute pac discriminator
+  assert(isUInt<16>(Disc));
+  Register DiscReg = emitPtrauthDiscriminator(
+      Disc, AddrDisc, ScratchReg, /*MayUseAddrAsScratch=*/AddrDiscKilled);
+  bool IsZeroDisc = DiscReg == AArch64::XZR;
+  unsigned Opc = getPACOpcodeForKey(Key, IsZeroDisc);
+
+  //  paciza x16      ; if  IsZeroDisc
+  //  pacia x16, x17  ; if !IsZeroDisc
+  MCInst PACInst;
+  PACInst.setOpcode(Opc);
+  PACInst.addOperand(MCOperand::createReg(Val));
+  PACInst.addOperand(MCOperand::createReg(Val));
+  if (!IsZeroDisc)
+    PACInst.addOperand(MCOperand::createReg(DiscReg));
+  EmitToStreamer(*OutStreamer, PACInst);
+}
+
 void AArch64AsmPrinter::emitPtrauthBranch(const MachineInstr *MI) {
   bool IsCall = MI->getOpcode() == AArch64::BLRA;
   unsigned BrTarget = MI->getOperand(0).getReg();
@@ -2890,6 +2924,10 @@ void AArch64AsmPrinter::emitInstruction(const MachineInstr *MI) {
         MI->getOperand(4).getImm(), MI->getOperand(5).getReg());
     return;
 
+  case AArch64::PAC:
+    emitPtrauthSign(MI);
+    return;
+
   case AArch64::LOADauthptrstatic:
     LowerLOADauthptrstatic(*MI);
     return;