Remove fixupPtrauthDiscriminator (not needed by PR130809)

Author: atrosinenko

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -3228,7 +3228,7 @@ AArch64TargetLowering::EmitEntryPStateSM(MachineInstr &MI,
   return BB;
 }
 
-// Partially used by https://github.com/llvm/llvm-project/pull/130809.
+// Used by https://github.com/llvm/llvm-project/pull/130809.
 #if 0
 // Helper function to find the instruction that defined a virtual register.
 // If unable to find such instruction, returns nullptr.
@@ -3255,32 +3255,6 @@ static const MachineInstr *stripVRegCopies(const MachineRegisterInfo &MRI,
   }
   return nullptr;
 }
-
-void AArch64TargetLowering::fixupPtrauthDiscriminator(
-    MachineInstr &MI, MachineBasicBlock *BB, MachineOperand &IntDiscOp,
-    MachineOperand &AddrDiscOp, const TargetRegisterClass *AddrDiscRC) const {
-  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
-  MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
-  const DebugLoc &DL = MI.getDebugLoc();
-
-  Register AddrDisc = AddrDiscOp.getReg();
-  int64_t IntDisc = IntDiscOp.getImm();
-
-  // For uniformity, always use NoRegister, as XZR is not necessarily contained
-  // in the requested register class.
-  if (AddrDisc == AArch64::XZR)
-    AddrDisc = AArch64::NoRegister;
-
-  // Make sure AddrDisc operand respects the register class imposed by MI.
-  if (AddrDisc && MRI.getRegClass(AddrDisc) != AddrDiscRC) {
-    Register TmpReg = MRI.createVirtualRegister(AddrDiscRC);
-    BuildMI(*BB, MI, DL, TII->get(AArch64::COPY), TmpReg).addReg(AddrDisc);
-    AddrDisc = TmpReg;
-  }
-
-  AddrDiscOp.setReg(AddrDisc);
-  IntDiscOp.setImm(IntDisc);
-}
 #endif
 
 MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
@@ -3388,10 +3362,6 @@ MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
     return EmitZTInstr(MI, BB, AArch64::MOVT_TIZ, /*Op0IsDef=*/true);
 
   case AArch64::PAC:
-#if 0
-    fixupPtrauthDiscriminator(MI, BB, MI.getOperand(3), MI.getOperand(4),
-                              &AArch64::GPR64noipRegClass);
-#endif
     return BB;
   }
 }

llvm/lib/Target/AArch64/AArch64ISelLowering.h

@@ -195,13 +195,6 @@ class AArch64TargetLowering : public TargetLowering {
   MachineBasicBlock *EmitEntryPStateSM(MachineInstr &MI,
                                        MachineBasicBlock *BB) const;
 
-  /// Replace (0, vreg) discriminator components with the operands of blend
-  /// or with (immediate, NoRegister) when possible.
-  void fixupPtrauthDiscriminator(MachineInstr &MI, MachineBasicBlock *BB,
-                                 MachineOperand &IntDiscOp,
-                                 MachineOperand &AddrDiscOp,
-                                 const TargetRegisterClass *AddrDiscRC) const;
-
   MachineBasicBlock *
   EmitInstrWithCustomInserter(MachineInstr &MI,
                               MachineBasicBlock *MBB) const override;