[AArch64] Enable ARMv8.3-A pointer authentication

[samparker]

Summary

Add assembler and disassembler support for the ARMv8.3-A pointer authentication instructions.

[SjoerdMeijer]

Looks okay to me.

lib/Target/AArch64/AArch64InstrFormats.td

   let ParserMatchClass = GPR32as64Operand;
 }
 
 // 8-bit immediate for AdvSIMD where 64-bit values of the form:
 // aaaaaaaa bbbbbbbb cccccccc dddddddd eeeeeeee ffffffff gggggggg hhhhhhhh
 // are encoded as the eight bit value 'abcdefgh'.
 def SIMDImmType10Operand : AsmOperandClass { let Name = "SIMDImmType10"; }
 
+// Authenticated loads for v8.3 can have scaled 10-bit immediate offsets.
+def SImm10s8Operand : AsmOperandClass {
+  let Name = "SImm10s8";
+  let DiagnosticType = "InvalidMemoryIndexedSImm10";
+}
 
 //===----------------------------------------------------------------------===//
 // Operand Definitions.
 //
 
 // ADR[P] instruction labels.
 def AdrpOperand : AsmOperandClass {
   let Name = "AdrpLabel";

   let ParserMethod = "tryParseAdrLabel";
   let DiagnosticType = "InvalidLabel";
 }
 def adrlabel : Operand<i64> {
   let EncoderMethod = "getAdrLabelOpValue";
   let ParserMatchClass = AdrOperand;
 }
 
+def simm10Scaled : Operand<i64> {
+  let ParserMatchClass = SImm10s8Operand;
+  let DecoderMethod = "DecodeSImm<10>";
+  let PrintMethod = "printImmScale<8>";
+}
+
 // simm9 predicate - True if the immediate is in the range [-256, 255].
 def SImm9Operand : AsmOperandClass {
   let Name = "SImm9";
   let DiagnosticType = "InvalidMemoryIndexedSImm9";
 }
 def simm9 : Operand<i64>, ImmLeaf<i64, [{ return Imm >= -256 && Imm < 256; }]> {
   let ParserMatchClass = SImm9Operand;
 }

     : SimpleSystemI<0, (ins crmtype:$CRm), asm, "\t$CRm", pattern>,
       Sched<[WriteBarrier]> {
   bits<4> CRm;
   let Inst{20-12} = 0b000110011;
   let Inst{11-8} = CRm;
   let Inst{7-5} = opc;
 }
 
+class SystemNoOperands<bits<3> op2, string asm, list<dag> pattern = []>
+    : SimpleSystemI<0, (ins), asm, "", pattern>,
+      Sched<[]> {
+  bits<4> CRm;
+  let CRm = 0b0011;
+  let Inst{31-12} = 0b11010101000000110010;
+  let Inst{11-8} = CRm;
+  let Inst{7-5} = op2;
+  let Inst{4-0} = 0b11111;
+}
+
 // MRS/MSR system instructions. These have different operand classes because
 // a different subset of registers can be accessed through each instruction.
 def MRSSystemRegisterOperand : AsmOperandClass {
   let Name = "MRSSystemRegister";
   let ParserMethod = "tryParseSysReg";
   let DiagnosticType = "MRS";
 }
 // concatenation of op0, op1, CRn, CRm, op2. 16-bit immediate.

 }
 
 let mayLoad = 0, mayStore = 0, hasSideEffects = 1, isReturn = 1 in
 class SpecialReturn<bits<4> opc, string asm>
     : BaseBranchReg<opc, (outs), (ins), asm, "", []> {
   let Inst{9-5} = 0b11111;
 }
 
+class AuthBase<bits<1> M, dag oops, dag iops, string asm, string operands,
+               list<dag> pattern>
+  : I<oops, iops, asm, operands, "", pattern>, Sched<[]> {
+  let Inst{31-25} = 0b1101011;
+  let Inst{20-11} = 0b1111100001;
+  let Inst{10} = M;
+  let Inst{4-0} = 0b11111;
+}
+
+class AuthBranchTwoOperands<bits<1> op, bits<1> M, string asm>
+  : AuthBase<M, (outs), (ins GPR64:$Rn, GPR64sp:$Rm), asm, "\t$Rn, $Rm", []> {
+  bits<5> Rn;
+  bits<5> Rm;
+  let Inst{24-22} = 0b100;
+  let Inst{21} = op;
+  let Inst{9-5} = Rn;
+  let Inst{4-0} = Rm;
+}
+
+class AuthOneOperand<bits<3> opc, bits<1> M, string asm>
+  : AuthBase<M, (outs), (ins GPR64:$Rn), asm, "\t$Rn", []> {
+  bits<5> Rn;
+  let Inst{24} = 0;
+  let Inst{23-21} = opc;
+  let Inst{9-5} = Rn;
+}
+
+class AuthReturn<bits<3> op, bits<1> M, string asm>
+  : AuthBase<M, (outs), (ins), asm, "", []> {
+  let Inst{24} = 0;
+  let Inst{23-21} = op;
+  let Inst{9-0} = 0b1111111111;
+}
+
+let mayLoad = 1 in
+class BaseAuthLoad<bit M, bit W, dag oops, dag iops, string asm,
+                   string operands, string cstr, Operand opr>
+  : I<oops, iops, asm, operands, "", []>, Sched<[]> {
+  bits<10> offset;
+  bits<5> Rn;
+  bits<5> Rt;
+  let Inst{31-24} = 0b11111000;
+  let Inst{23} = M;
+  let Inst{22} = offset{9};
+  let Inst{21} = 1;
+  let Inst{20-12} = offset{8-0};
+  let Inst{11} = W;
+  let Inst{10} = 1;
+  let Inst{9-5} = Rn;
+  let Inst{4-0} = Rt;
+}
+
+multiclass AuthLoad<bit M, string asm, Operand opr> {
+  def indexed   : BaseAuthLoad<M, 0, (outs GPR64:$Rt), (ins GPR64sp:$Rn, opr:$offset),
+                               asm, "\t$Rt, [$Rn, $offset]", "", opr>;
+  def writeback : BaseAuthLoad<M, 1, (outs GPR64sp:$wback, GPR64:$Rt),
+                               (ins GPR64sp:$Rn, opr:$offset),
+                               asm, "\t$Rt, [$Rn, $offset]!",
+                               "$Rn = $wback,@earlyclobber $wback", opr> {
+    let DecoderMethod = "DecodeAuthLoadWriteback";
+  }
+
+  def : InstAlias<asm # "\t$Rt, [$Rn]",
+                  (!cast<Instruction>(NAME # "indexed") GPR64:$Rt, GPR64sp:$Rn, 0)>;
+}
+
 //---
 // Conditional branch instruction.
 //---
 
 // Condition code.
 // 4-bit immediate. Pretty-printed as <cc>
 def ccode : Operand<i32> {
   let PrintMethod = "printCondCode";

   let Inst{31} = 0;
 }
 
 class OneXRegData<bits<3> opc, string asm, SDPatternOperator node>
     : BaseOneOperandData<opc, GPR64, asm, node> {
   let Inst{31} = 1;
 }
 
+class SignAuthOneData<bits<3> opcode_prefix, bits<2> opcode, string asm>
+  : I<(outs GPR64:$Rd), (ins GPR64sp:$Rn), asm, "\t$Rd, $Rn", "",
+      []>,
+    Sched<[WriteI, ReadI]> {
+  bits<5> Rd;
+  bits<5> Rn;
+  let Inst{31-15} = 0b11011010110000010;
+  let Inst{14-12} = opcode_prefix;
+  let Inst{11-10} = opcode;
+  let Inst{9-5} = Rn;
+  let Inst{4-0} = Rd;
+}
+
+class SignAuthZero<bits<3> opcode_prefix, bits<2> opcode, string asm>
+  : I<(outs GPR64:$Rd), (ins), asm, "\t$Rd", "", []>, Sched<[]> {
+  bits<5> Rd;
+  let Inst{31-15} = 0b11011010110000010;
+  let Inst{14-12} = opcode_prefix;
+  let Inst{11-10} = opcode;
+  let Inst{9-5} = 0b11111;
+  let Inst{4-0} = Rd;
+}
+
+class SignAuthTwoOperand<bits<4> opc, string asm,
+                         SDPatternOperator OpNode>
+  : I<(outs GPR64:$Rd), (ins GPR64:$Rn, GPR64sp:$Rm),
+      asm, "\t$Rd, $Rn, $Rm", "",
+      [(set GPR64:$Rd, (OpNode GPR64:$Rn, GPR64sp:$Rm))]>,
+    Sched<[WriteI, ReadI, ReadI]> {
+  bits<5> Rd;
+  bits<5> Rn;
+  bits<5> Rm;
+  let Inst{31-21} = 0b10011010110;
+  let Inst{20-16} = Rm;
+  let Inst{15-14} = 0b00;
+  let Inst{13-10} = opc;
+  let Inst{9-5}   = Rn;
+  let Inst{4-0}   = Rd;
+}
+
 //---
 // Basic two-operand data processing instructions.
 //---
 class BaseBaseAddSubCarry<bit isSub, RegisterClass regtype, string asm,
                           list<dag> pattern>
     : I<(outs regtype:$Rd), (ins regtype:$Rn, regtype:$Rm),
         asm, "\t$Rd, $Rn, $Rm", "", pattern>,
       Sched<[WriteI, ReadI, ReadI]> {

lib/Target/AArch64/AArch64InstrInfo.td

 
 def DSB   : CRmSystemI<barrier_op, 0b100, "dsb",
                        [(int_aarch64_dsb (i32 imm32_0_15:$CRm))]>;
 
 def ISB   : CRmSystemI<barrier_op, 0b110, "isb",
                        [(int_aarch64_isb (i32 imm32_0_15:$CRm))]>;
 }
 
+let Predicates = [HasV8_3a] in {
+  // v8.3a Pointer Authentication
+  let Uses = [LR], Defs = [LR] in {
+    def PACIAZ   : SystemNoOperands<0b000, "paciaz">;
+    def PACIBZ   : SystemNoOperands<0b010, "pacibz">;
+    def AUTIAZ   : SystemNoOperands<0b100, "autiaz">;
+    def AUTIBZ   : SystemNoOperands<0b110, "autibz">;
+  }
+  let Uses = [LR, SP], Defs = [LR] in {
+    def PACIASP  : SystemNoOperands<0b001, "paciasp">;
+    def PACIBSP  : SystemNoOperands<0b011, "pacibsp">;
+    def AUTIASP  : SystemNoOperands<0b101, "autiasp">;
+    def AUTIBSP  : SystemNoOperands<0b111, "autibsp">;
+  }
+  let Uses = [X16, X17], Defs = [X17], CRm = 0b0001 in {
+    def PACIA1716  : SystemNoOperands<0b000, "pacia1716">;
+    def PACIB1716  : SystemNoOperands<0b010, "pacib1716">;
+    def AUTIA1716  : SystemNoOperands<0b100, "autia1716">;
+    def AUTIB1716  : SystemNoOperands<0b110, "autib1716">;
+  }
+
+  let Uses = [LR], Defs = [LR], CRm = 0b0000 in {
+    def XPACLRI   : SystemNoOperands<0b111, "xpaclri">;
+  }
+
+  multiclass SignAuth<bits<3> prefix, bits<3> prefix_z, string asm> {
+    def IA   : SignAuthOneData<prefix, 0b00, !strconcat(asm, "ia")>;
+    def IB   : SignAuthOneData<prefix, 0b01, !strconcat(asm, "ib")>;
+    def DA   : SignAuthOneData<prefix, 0b10, !strconcat(asm, "da")>;
+    def DB   : SignAuthOneData<prefix, 0b11, !strconcat(asm, "db")>;
+    def IZA  : SignAuthZero<prefix_z, 0b00, !strconcat(asm, "iza")>;
+    def DZA  : SignAuthZero<prefix_z, 0b10, !strconcat(asm, "dza")>;
+    def IZB  : SignAuthZero<prefix_z, 0b01, !strconcat(asm, "izb")>;
+    def DZB  : SignAuthZero<prefix_z, 0b11, !strconcat(asm, "dzb")>;
+  }
+
+  defm PAC : SignAuth<0b000, 0b010, "pac">;
+  defm AUT : SignAuth<0b001, 0b011, "aut">;
+
+  def XPACI : SignAuthZero<0b100, 0b00, "xpaci">;
+  def XPACD : SignAuthZero<0b100, 0b01, "xpacd">;
+  def PACGA : SignAuthTwoOperand<0b1100, "pacga", null_frag>;
+
+  // Combined Instructions
+  def BRAA    : AuthBranchTwoOperands<0, 0, "braa">;
+  def BRAB    : AuthBranchTwoOperands<0, 1, "brab">;
+  def BLRAA   : AuthBranchTwoOperands<1, 0, "blraa">;
+  def BLRAB   : AuthBranchTwoOperands<1, 1, "blrab">;
+
+  def BRAAZ   : AuthOneOperand<0b000, 0, "braaz">;
+  def BRABZ   : AuthOneOperand<0b000, 1, "brabz">;
+  def BLRAAZ  : AuthOneOperand<0b001, 0, "blraaz">;
+  def BLRABZ  : AuthOneOperand<0b001, 1, "blrabz">;
+
+  let isReturn = 1 in {
+    def RETAA   : AuthReturn<0b010, 0, "retaa">;
+    def RETAB   : AuthReturn<0b010, 1, "retab">;
+    def ERETAA  : AuthReturn<0b100, 0, "eretaa">;
+    def ERETAB  : AuthReturn<0b100, 1, "eretab">;
+  }
+
+  defm LDRAA  : AuthLoad<0, "ldraa", simm10Scaled>;
+  defm LDRAB  : AuthLoad<1, "ldrab", simm10Scaled>;
+
+} // HasV8_3A
+
 def : InstAlias<"clrex", (CLREX 0xf)>;
 def : InstAlias<"isb", (ISB 0xf)>;
 
 def MRS    : MRSI;
 def MSR    : MSRI;
 def MSRpstateImm1 : MSRpstateImm0_1;
 def MSRpstateImm4 : MSRpstateImm0_15;
 

lib/Target/AArch64/AArch64SchedThunderX.td

                               WriteIM32, WriteIM64]>;
 
 //===----------------------------------------------------------------------===//
 // Subtarget-specific InstRW.
 
 //---
 // Branch
 //---
-def : InstRW<[THXT8XWriteBR], (instregex "^B")>;
-def : InstRW<[THXT8XWriteBR], (instregex "^BL")>;
-def : InstRW<[THXT8XWriteBR], (instregex "^B.*")>;
+def : InstRW<[THXT8XWriteBR], (instregex "^B$")>;
+def : InstRW<[THXT8XWriteBR], (instregex "^BL$")>;
+def : InstRW<[THXT8XWriteBR], (instregex "^B..$")>;
 def : InstRW<[THXT8XWriteBR], (instregex "^CBNZ")>;
 def : InstRW<[THXT8XWriteBR], (instregex "^CBZ")>;
 def : InstRW<[THXT8XWriteBR], (instregex "^TBNZ")>;
 def : InstRW<[THXT8XWriteBR], (instregex "^TBZ")>;
-def : InstRW<[THXT8XWriteBRR], (instregex "^BR")>;
-def : InstRW<[THXT8XWriteBRR], (instregex "^BLR")>;
+def : InstRW<[THXT8XWriteBRR], (instregex "^BR$")>;
+def : InstRW<[THXT8XWriteBRR], (instregex "^BLR$")>;
 
 //---
 // Ret
 //---
-def : InstRW<[THXT8XWriteRET], (instregex "^RET")>;
+def : InstRW<[THXT8XWriteRET], (instregex "^RET$")>;
 
 //---
 // Miscellaneous
 //---
 def : InstRW<[WriteI], (instrs COPY)>;
 
 //---
 // Vector Loads

lib/Target/AArch64/AArch64SchedThunderX2T99.td

   let NumMicroOps = 2;
 }
 
 //---
 // Branch
 //---
 def : InstRW<[THX2T99Write_1Cyc_I2], (instrs B, BL, BR, BLR)>;
 def : InstRW<[THX2T99Write_1Cyc_I2], (instrs RET)>;
-def : InstRW<[THX2T99Write_1Cyc_I2], (instregex "^B.*")>;
+def : InstRW<[THX2T99Write_1Cyc_I2], (instregex "^B..$")>;
 def : InstRW<[THX2T99Write_1Cyc_I2],
             (instregex "^CBZ", "^CBNZ", "^TBZ", "^TBNZ")>;
 
 //---
 // 3.2 Arithmetic and Logical Instructions
 // 3.3 Move and Shift Instructions
 //---
 

lib/Target/AArch64/AArch64SystemOperands.td

 def : RWSysReg<"ERXADDR_EL1",   0b11, 0b000, 0b0101, 0b0100, 0b011>;
 def : RWSysReg<"ERXMISC0_EL1",  0b11, 0b000, 0b0101, 0b0101, 0b000>;
 def : RWSysReg<"ERXMISC1_EL1",  0b11, 0b000, 0b0101, 0b0101, 0b001>;
 def : RWSysReg<"DISR_EL1",      0b11, 0b000, 0b1100, 0b0001, 0b001>;
 def : RWSysReg<"VDISR_EL2",     0b11, 0b100, 0b1100, 0b0001, 0b001>;
 def : RWSysReg<"VSESR_EL2",     0b11, 0b100, 0b0101, 0b0010, 0b011>;
 }
 
+// v8.3a "Pointer authentication extension" registers
+//                              Op0    Op1     CRn     CRm    Op2
+let Requires = [{ {AArch64::HasV8_3aOps} }] in {
+def : RWSysReg<"APIAKeyLo_EL1", 0b11, 0b000, 0b0010, 0b0001, 0b000>;
+def : RWSysReg<"APIAKeyHi_EL1", 0b11, 0b000, 0b0010, 0b0001, 0b001>;
+def : RWSysReg<"APIBKeyLo_EL1", 0b11, 0b000, 0b0010, 0b0001, 0b010>;
+def : RWSysReg<"APIBKeyHi_EL1", 0b11, 0b000, 0b0010, 0b0001, 0b011>;
+def : RWSysReg<"APDAKeyLo_EL1", 0b11, 0b000, 0b0010, 0b0010, 0b000>;
+def : RWSysReg<"APDAKeyHi_EL1", 0b11, 0b000, 0b0010, 0b0010, 0b001>;
+def : RWSysReg<"APDBKeyLo_EL1", 0b11, 0b000, 0b0010, 0b0010, 0b010>;
+def : RWSysReg<"APDBKeyHi_EL1", 0b11, 0b000, 0b0010, 0b0010, 0b011>;
+def : RWSysReg<"APGAKeyLo_EL1", 0b11, 0b000, 0b0010, 0b0011, 0b000>;
+def : RWSysReg<"APGAKeyHi_EL1", 0b11, 0b000, 0b0010, 0b0011, 0b001>;
+}
+
 // Cyclone specific system registers
 //                                 Op0    Op1     CRn     CRm    Op2
 let Requires = [{ {AArch64::ProcCyclone} }] in
 def : RWSysReg<"CPM_IOACC_CTL_EL3", 0b11, 0b111, 0b1111, 0b0010, 0b000>;

lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

     if (!isImm())
       return false;
     const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(getImm());
     if (!MCE)
       return false;
     int64_t Val = MCE->getValue();
     return (Val >= -256 && Val < 256);
   }
+  bool isSImm10s8() const {
+    if (!isImm())
+      return false;
+    const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(getImm());
+    if (!MCE)
+      return false;
+    int64_t Val = MCE->getValue();
+    return (Val >= -4096 && Val < 4089 && (Val & 7) == 0);
+  }
   bool isSImm7s4() const {
     if (!isImm())
       return false;
     const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(getImm());
     if (!MCE)
       return false;
     int64_t Val = MCE->getValue();
     return (Val >= -256 && Val <= 252 && (Val & 3) == 0);

   }
 
   void addSImm9Operands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     const MCConstantExpr *MCE = cast<MCConstantExpr>(getImm());
     Inst.addOperand(MCOperand::createImm(MCE->getValue()));
   }
 
+  void addSImm10s8Operands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    const MCConstantExpr *MCE = cast<MCConstantExpr>(getImm());
+    Inst.addOperand(MCOperand::createImm(MCE->getValue() / 8));
+  }
+
   void addSImm7s4Operands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     const MCConstantExpr *MCE = cast<MCConstantExpr>(getImm());
     Inst.addOperand(MCOperand::createImm(MCE->getValue() / 4));
   }
 
   void addSImm7s8Operands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");

   case Match_AddSubRegShift64:
     return Error(Loc,
        "expected 'lsl', 'lsr' or 'asr' with optional integer in range [0, 63]");
   case Match_InvalidFPImm:
     return Error(Loc,
                  "expected compatible register or floating-point constant");
   case Match_InvalidMemoryIndexedSImm9:
     return Error(Loc, "index must be an integer in range [-256, 255].");
+  case Match_InvalidMemoryIndexedSImm10:
+    return Error(Loc, "index must be a multiple of 8 in range [-4096, 4088].");
   case Match_InvalidMemoryIndexed4SImm7:
     return Error(Loc, "index must be a multiple of 4 in range [-256, 252].");
   case Match_InvalidMemoryIndexed8SImm7:
     return Error(Loc, "index must be a multiple of 8 in range [-512, 504].");
   case Match_InvalidMemoryIndexed16SImm7:
     return Error(Loc, "index must be a multiple of 16 in range [-1024, 1008].");
   case Match_InvalidMemoryWExtend8:
     return Error(Loc,

   case Match_InvalidMemoryXExtend16:
   case Match_InvalidMemoryXExtend32:
   case Match_InvalidMemoryXExtend64:
   case Match_InvalidMemoryXExtend128:
   case Match_InvalidMemoryIndexed4SImm7:
   case Match_InvalidMemoryIndexed8SImm7:
   case Match_InvalidMemoryIndexed16SImm7:
   case Match_InvalidMemoryIndexedSImm9:
+  case Match_InvalidMemoryIndexedSImm10:
   case Match_InvalidImm0_1:
   case Match_InvalidImm0_7:
   case Match_InvalidImm0_15:
   case Match_InvalidImm0_31:
   case Match_InvalidImm0_63:
   case Match_InvalidImm0_127:
   case Match_InvalidImm0_255:
   case Match_InvalidImm0_65535:

lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp

 static DecodeStatus DecodeWSeqPairsClassRegisterClass(MCInst &Inst,
                                                       unsigned RegNo,
                                                       uint64_t Addr,
                                                       const void *Decoder);
 static DecodeStatus DecodeXSeqPairsClassRegisterClass(MCInst &Inst,
                                                       unsigned RegNo,
                                                       uint64_t Addr,
                                                       const void *Decoder);
+template<int Bits>
+static DecodeStatus DecodeSImm(llvm::MCInst &Inst, uint64_t Imm,
+                               uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeAuthLoadWriteback(llvm::MCInst &Inst, uint32_t insn,
+                                            uint64_t Address,
+                                            const void *Decoder);
 
 static bool Check(DecodeStatus &Out, DecodeStatus In) {
   switch (In) {
     case MCDisassembler::Success:
       // Out stays the same.
       return true;
     case MCDisassembler::SoftFail:
       Out = In;

 static DecodeStatus DecodeXSeqPairsClassRegisterClass(MCInst &Inst,
                                                       unsigned RegNo,
                                                       uint64_t Addr,
                                                       const void *Decoder) {
   return DecodeGPRSeqPairsClassRegisterClass(Inst,
                                              AArch64::XSeqPairsClassRegClassID,
                                              RegNo, Addr, Decoder);
 }
+
+template<int Bits>
+static DecodeStatus DecodeSImm(llvm::MCInst &Inst, uint64_t Imm,
+                               uint64_t Address, const void *Decoder) {
+  if (Imm & ~((1LL << Bits) - 1))
+      return Fail;
+
+  // Imm is a signed immediate, so sign extend it.
+  if (Imm & (1 << (Bits - 1)))
+    Imm |= ~((1LL << Bits) - 1);
+
+  Inst.addOperand(MCOperand::createImm(Imm));
+  return Success;
+}
+
+static DecodeStatus DecodeAuthLoadWriteback(llvm::MCInst &Inst, uint32_t insn,
+                                            uint64_t Address,
+                                            const void *Decoder) {
+  unsigned Rt = fieldFromInstruction(insn, 0, 5);
+  unsigned Rn = fieldFromInstruction(insn, 5, 5);
+  unsigned Imm9 = fieldFromInstruction(insn, 12, 9);
+  unsigned S = fieldFromInstruction(insn, 22, 1);
+
+  unsigned Imm = Imm9 | (S << 9);
+
+  // Address writeback
+  DecodeGPR64spRegisterClass(Inst, Rn, Address, Decoder);
+  // Destination
+  DecodeGPR64RegisterClass(Inst, Rt, Address, Decoder);
+  // Address
+  DecodeGPR64spRegisterClass(Inst, Rn, Address, Decoder);
+  // Offset
+  DecodeSImm<10>(Inst, Imm, Address, Decoder);
+
+  return Success;
+}

lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp

uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
                               const MCSubtargetInfo &STI) const;
 
   /// getAddSubImmOpValue - Return encoding for the 12-bit immediate value and
   /// the 2-bit shift field.
   uint32_t getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
                                SmallVectorImpl<MCFixup> &Fixups,
                                const MCSubtargetInfo &STI) const;
 
+  /// getAuthSImmOpValue - Return encoding for a 10-bit immediate which is
+  /// encoded as a sign bit and an 9-bit immediate, separated by a single bit.
+  uint32_t getAuthSImmOpValue(const MCInst &MI, unsigned OpIdx,
+                              SmallVectorImpl<MCFixup> &Fixups,
+                              const MCSubtargetInfo &STI) const;
+
   /// getCondBranchTargetOpValue - Return the encoded value for a conditional
   /// branch target.
   uint32_t getCondBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
                                       SmallVectorImpl<MCFixup> &Fixups,
                                       const MCSubtargetInfo &STI) const;
 
   /// getLoadLiteralOpValue - Return the encoded value for a load-literal
   /// pc-relative address.
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
     AArch64MCExpr::VariantKind RefKind = A64E->getKind();
     if (RefKind == AArch64MCExpr::VK_TPREL_HI12 ||
         RefKind == AArch64MCExpr::VK_DTPREL_HI12)
       ShiftVal = 12;
   }
   return ShiftVal == 0 ? 0 : (1 << ShiftVal);
 }
 
+/// getAuthSImmOpValue - encode a 10-bit scale signed immediate within an 11-bit
+/// field in which bit 10 of that field is not used to encode any information
+/// about the immediate.
+uint32_t
+AArch64MCCodeEmitter::getAuthSImmOpValue(const MCInst &MI, unsigned OpIdx,
+                                         SmallVectorImpl<MCFixup> &Fixups,
+                                         const MCSubtargetInfo &STI) const {
+  const MCOperand &MO = MI.getOperand(OpIdx);
+  int32_t offset = MO.getImm();
+  return (uint32_t)offset;
+}
+
 /// getCondBranchTargetOpValue - Return the encoded value for a conditional
 /// branch target.
 uint32_t AArch64MCCodeEmitter::getCondBranchTargetOpValue(
     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
     const MCSubtargetInfo &STI) const {
   const MCOperand &MO = MI.getOperand(OpIdx);
 
   // If the destination is an immediate, we have nothing to do.

test/MC/AArch64/armv8.3a-diagnostics.s

+// RUN: not llvm-mc -triple aarch64-none-linux-gnu -mattr=+v8.3a < %s 2> %t
+// RUN: FileCheck %s < %t
+
+ msr ID_ISAR6_EL1, x0
+// CHECK: error: expected writable system register or pstate
+// CHECK-NEXT: msr ID_ISAR6_EL1, x0
+// CHECK-NEXT:     ^
+
+  ldraa x0, [x1, 4089]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].
+  ldraa x0, [x1, -4097]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].
+  ldraa x0, [x1, 4086]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].
+  ldrab x0, [x1, 4089]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].
+  ldrab x0, [x1, -4097]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].
+  ldrab x0, [x1, 4086]
+// CHECK: error: index must be a multiple of 8 in range [-4096, 4088].

test/MC/AArch64/armv8.3a-signed-pointer.s

+// RUN: llvm-mc -triple aarch64-none-linux-gnu -show-encoding -mattr=+v8.3a < %s 2> %t | FileCheck %s
+// RUN: not llvm-mc -triple aarch64-none-linux-gnu < %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-REQ %s < %t
+
+  mrs x0, apiakeylo_el1
+  mrs x0, apiakeyhi_el1
+  mrs x0, apibkeylo_el1
+  mrs x0, apibkeyhi_el1
+  mrs x0, apdakeylo_el1
+  mrs x0, apdakeyhi_el1
+  mrs x0, apdbkeylo_el1
+  mrs x0, apdbkeyhi_el1
+  mrs x0, apgakeylo_el1
+  mrs x0, apgakeyhi_el1
+
+// CHECK: mrs x0, APIAKeyLo_EL1     // encoding: [0x00,0x21,0x38,0xd5]
+// CHECK: mrs x0, APIAKeyHi_EL1     // encoding: [0x20,0x21,0x38,0xd5]
+// CHECK: mrs x0, APIBKeyLo_EL1     // encoding: [0x40,0x21,0x38,0xd5]
+// CHECK: mrs x0, APIBKeyHi_EL1     // encoding: [0x60,0x21,0x38,0xd5]
+// CHECK: mrs x0, APDAKeyLo_EL1     // encoding: [0x00,0x22,0x38,0xd5]
+// CHECK: mrs x0, APDAKeyHi_EL1     // encoding: [0x20,0x22,0x38,0xd5]
+// CHECK: mrs x0, APDBKeyLo_EL1     // encoding: [0x40,0x22,0x38,0xd5]
+// CHECK: mrs x0, APDBKeyHi_EL1     // encoding: [0x60,0x22,0x38,0xd5]
+// CHECK: mrs x0, APGAKeyLo_EL1     // encoding: [0x00,0x23,0x38,0xd5]
+// CHECK: mrs x0, APGAKeyHi_EL1     // encoding: [0x20,0x23,0x38,0xd5]
+
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+// CHECK-REQ: error: expected readable system register
+
+  msr apiakeylo_el1, x0
+  msr apiakeyhi_el1, x0
+  msr apibkeylo_el1, x0
+  msr apibkeyhi_el1, x0
+  msr apdakeylo_el1, x0
+  msr apdakeyhi_el1, x0
+  msr apdbkeylo_el1, x0
+  msr apdbkeyhi_el1, x0
+  msr apgakeylo_el1, x0
+  msr apgakeyhi_el1, x0
+
+// CHECK: msr APIAKeyLo_EL1, x0     // encoding: [0x00,0x21,0x18,0xd5]
+// CHECK: msr APIAKeyHi_EL1, x0     // encoding: [0x20,0x21,0x18,0xd5]
+// CHECK: msr APIBKeyLo_EL1, x0     // encoding: [0x40,0x21,0x18,0xd5]
+// CHECK: msr APIBKeyHi_EL1, x0     // encoding: [0x60,0x21,0x18,0xd5]
+// CHECK: msr APDAKeyLo_EL1, x0     // encoding: [0x00,0x22,0x18,0xd5]
+// CHECK: msr APDAKeyHi_EL1, x0     // encoding: [0x20,0x22,0x18,0xd5]
+// CHECK: msr APDBKeyLo_EL1, x0     // encoding: [0x40,0x22,0x18,0xd5]
+// CHECK: msr APDBKeyHi_EL1, x0     // encoding: [0x60,0x22,0x18,0xd5]
+// CHECK: msr APGAKeyLo_EL1, x0     // encoding: [0x00,0x23,0x18,0xd5]
+// CHECK: msr APGAKeyHi_EL1, x0     // encoding: [0x20,0x23,0x18,0xd5]
+
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+// CHECK-REQ: error: expected writable system register or pstate
+
+  paciasp
+// CHECK: paciasp        // encoding: [0x3f,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autiasp
+// CHECK: autiasp        // encoding: [0xbf,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  paciaz
+// CHECK: paciaz         // encoding: [0x1f,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autiaz
+// CHECK: autiaz         // encoding: [0x9f,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacia1716
+// CHECK: pacia1716      // encoding: [0x1f,0x21,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autia1716
+// CHECK: autia1716      // encoding: [0x9f,0x21,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacibsp
+// CHECK: pacibsp        // encoding: [0x7f,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autibsp
+// CHECK: autibsp        // encoding: [0xff,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacibz
+// CHECK: pacibz         // encoding: [0x5f,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autibz
+// CHECK: autibz         // encoding: [0xdf,0x23,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacib1716
+// CHECK: pacib1716      // encoding: [0x5f,0x21,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autib1716
+// CHECK: autib1716      // encoding: [0xdf,0x21,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  xpaclri
+// CHECK: xpaclri           // encoding: [0xff,0x20,0x03,0xd5]
+// CHECK-REQ: error: instruction requires: armv8.3a
+
+  pacia x0, x1
+// CHECK: pacia x0, x1     // encoding: [0x20,0x00,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autia x0, x1
+// CHECK: autia x0, x1     // encoding: [0x20,0x10,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacda x0, x1
+// CHECK: pacda x0, x1     // encoding: [0x20,0x08,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autda x0, x1
+// CHECK: autda x0, x1     // encoding: [0x20,0x18,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacib x0, x1
+// CHECK: pacib x0, x1     // encoding: [0x20,0x04,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autib x0, x1
+// CHECK: autib x0, x1     // encoding: [0x20,0x14,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacdb x0, x1
+// CHECK: pacdb x0, x1     // encoding: [0x20,0x0c,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autdb x0, x1
+// CHECK: autdb x0, x1     // encoding: [0x20,0x1c,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacga x0, x1, x2
+// CHECK: pacga x0, x1, x2  // encoding: [0x20,0x30,0xc2,0x9a]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  paciza x0
+// CHECK: paciza x0         // encoding: [0xe0,0x23,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autiza x0
+// CHECK: autiza x0         // encoding: [0xe0,0x33,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacdza x0
+// CHECK: pacdza x0         // encoding: [0xe0,0x2b,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autdza x0
+// CHECK: autdza x0         // encoding: [0xe0,0x3b,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacizb x0
+// CHECK: pacizb x0         // encoding: [0xe0,0x27,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autizb x0
+// CHECK: autizb x0         // encoding: [0xe0,0x37,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  pacdzb x0
+// CHECK: pacdzb x0         // encoding: [0xe0,0x2f,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  autdzb x0
+// CHECK: autdzb x0         // encoding: [0xe0,0x3f,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  xpaci x0
+// CHECK: xpaci x0          // encoding: [0xe0,0x43,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  xpacd x0
+// CHECK: xpacd x0          // encoding: [0xe0,0x47,0xc1,0xda]
+// CHECK-REQ: error: instruction requires: armv8.3a
+
+  braa x0, x1
+// CHECK: braa x0, x1       // encoding: [0x01,0x08,0x1f,0xd7]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  brab x0, x1
+// CHECK: brab x0, x1       // encoding: [0x01,0x0c,0x1f,0xd7]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  blraa x0, x1
+// CHECK: blraa x0, x1      // encoding: [0x01,0x08,0x3f,0xd7]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  blrab x0, x1
+// CHECK: blrab x0, x1      // encoding: [0x01,0x0c,0x3f,0xd7]
+// CHECK-REQ: error: instruction requires: armv8.3a
+
+  braaz x0
+// CHECK: braaz x0          // encoding: [0x1f,0x08,0x1f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  brabz x0
+// CHECK: brabz x0          // encoding: [0x1f,0x0c,0x1f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  blraaz x0
+// CHECK: blraaz x0         // encoding: [0x1f,0x08,0x3f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  blrabz x0
+// CHECK: blrabz x0         // encoding: [0x1f,0x0c,0x3f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  retaa
+// CHECK: retaa             // encoding: [0xff,0x0b,0x5f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  retab
+// CHECK: retab             // encoding: [0xff,0x0f,0x5f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  eretaa
+// CHECK: eretaa            // encoding: [0xff,0x0b,0x9f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  eretab
+// CHECK: eretab            // encoding: [0xff,0x0f,0x9f,0xd6]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldraa x0, [x1, 4088]
+// CHECK: ldraa x0, [x1, #4088]  // encoding: [0x20,0xf4,0x3f,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldraa x0, [x1, -4096]
+// CHECK: ldraa x0, [x1, #-4096] // encoding: [0x20,0x04,0x60,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldrab x0, [x1, 4088]
+// CHECK: ldrab x0, [x1, #4088]  // encoding: [0x20,0xf4,0xbf,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldrab x0, [x1, -4096]
+// CHECK: ldrab x0, [x1, #-4096] // encoding: [0x20,0x04,0xe0,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldraa x0, [x1, 4088]!
+// CHECK: ldraa x0, [x1, #4088]!  // encoding: [0x20,0xfc,0x3f,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldraa x0, [x1, -4096]!
+// CHECK: ldraa x0, [x1, #-4096]! // encoding: [0x20,0x0c,0x60,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldrab x0, [x1, 4088]!
+// CHECK: ldrab x0, [x1, #4088]!  // encoding: [0x20,0xfc,0xbf,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldrab x0, [x1, -4096]!
+// CHECK: ldrab x0, [x1, #-4096]! // encoding: [0x20,0x0c,0xe0,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldraa x0, [x1]
+// CHECK: ldraa x0, [x1]  // encoding: [0x20,0x04,0x20,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a
+  ldrab x0, [x1]
+// CHECK: ldrab x0, [x1]  // encoding: [0x20,0x04,0xa0,0xf8]
+// CHECK-REQ: error: instruction requires: armv8.3a

test/MC/Disassembler/AArch64/armv8.3a-signed-pointer.txt

+# RUN: llvm-mc -triple aarch64-none-linux-gnu -mattr=+v8.3a --disassemble < %s | FileCheck %s
+
+# CHECK: paciasp
+# CHECK: autiasp
+# CHECK: paciaz
+# CHECK: autiaz
+# CHECK: pacia1716
+# CHECK: autia1716
+# CHECK: pacibsp
+# CHECK: autibsp
+# CHECK: pacibz
+# CHECK: autibz
+# CHECK: pacib1716
+# CHECK: autib1716
+# CHECK: xpaclri
+[0x3f,0x23,0x03,0xd5]
+[0xbf,0x23,0x03,0xd5]
+[0x1f,0x23,0x03,0xd5]
+[0x9f,0x23,0x03,0xd5]
+[0x1f,0x21,0x03,0xd5]
+[0x9f,0x21,0x03,0xd5]
+[0x7f,0x23,0x03,0xd5]
+[0xff,0x23,0x03,0xd5]
+[0x5f,0x23,0x03,0xd5]
+[0xdf,0x23,0x03,0xd5]
+[0x5f,0x21,0x03,0xd5]
+[0xdf,0x21,0x03,0xd5]
+[0xff,0x20,0x03,0xd5]
+
+# CHECK: pacia x0, x1
+# CHECK: autia x0, x1
+# CHECK: pacda x0, x1
+# CHECK: autda x0, x1
+# CHECK: pacib x0, x1
+# CHECK: autib x0, x1
+# CHECK: pacdb x0, x1
+# CHECK: autdb x0, x1
+# CHECK: pacga x0, x1, x2
+# CHECK: paciza x0
+# CHECK: autiza x0
+# CHECK: pacdza x0
+# CHECK: autdza x0
+# CHECK: pacizb x0
+# CHECK: autizb x0
+# CHECK: pacdzb x0
+# CHECK: autdzb x0
+# CHECK: xpaci x0
+# CHECK: xpacd x0
+[0x20,0x00,0xc1,0xda]
+[0x20,0x10,0xc1,0xda]
+[0x20,0x08,0xc1,0xda]
+[0x20,0x18,0xc1,0xda]
+[0x20,0x04,0xc1,0xda]
+[0x20,0x14,0xc1,0xda]
+[0x20,0x0c,0xc1,0xda]
+[0x20,0x1c,0xc1,0xda]
+[0x20,0x30,0xc2,0x9a]
+[0xe0,0x23,0xc1,0xda]
+[0xe0,0x33,0xc1,0xda]
+[0xe0,0x2b,0xc1,0xda]
+[0xe0,0x3b,0xc1,0xda]
+[0xe0,0x27,0xc1,0xda]
+[0xe0,0x37,0xc1,0xda]
+[0xe0,0x2f,0xc1,0xda]
+[0xe0,0x3f,0xc1,0xda]
+[0xe0,0x43,0xc1,0xda]
+[0xe0,0x47,0xc1,0xda]
+
+# CHECK: braa x0, x1
+# CHECK: brab x0, x1
+# CHECK: blraa x0, x1
+# CHECK: blrab x0, x1
+[0x01,0x08,0x1f,0xd7]
+[0x01,0x0c,0x1f,0xd7]
+[0x01,0x08,0x3f,0xd7]
+[0x01,0x0c,0x3f,0xd7]
+
+# CHECK: braaz x0
+# CHECK: brabz x0
+# CHECK: blraaz x0
+# CHECK: blrabz x0
+# CHECK: retaa
+# CHECK: retab
+# CHECK: eretaa
+# CHECK: eretab
+# CHECK: ldraa x0, [x1, #4088]
+# CHECK: ldraa x0, [x1, #-4096]
+# CHECK: ldrab x0, [x1, #4088]
+# CHECK: ldrab x0, [x1, #-4096]
+# CHECK: ldraa x0, [x1, #4088]!
+# CHECK: ldraa x0, [x1, #-4096]!
+# CHECK: ldrab x0, [x1, #4088]!
+# CHECK: ldrab x0, [x1, #-4096]!
+[0x1f,0x08,0x1f,0xd6]
+[0x1f,0x0c,0x1f,0xd6]
+[0x1f,0x08,0x3f,0xd6]
+[0x1f,0x0c,0x3f,0xd6]
+[0xff,0x0b,0x5f,0xd6]
+[0xff,0x0f,0x5f,0xd6]
+[0xff,0x0b,0x9f,0xd6]
+[0xff,0x0f,0x9f,0xd6]
+[0x20,0xf4,0x3f,0xf8]
+[0x20,0x04,0x60,0xf8]
+[0x20,0xf4,0xbf,0xf8]
+[0x20,0x04,0xe0,0xf8]
+[0x20,0xfc,0x3f,0xf8]
+[0x20,0x0c,0x60,0xf8]
+[0x20,0xfc,0xbf,0xf8]
+[0x20,0x0c,0xe0,0xf8]
+
+# CHECK: ldraa x0, [x1]
+# CHECK: ldrab x0, [x1]
+[0x20,0x04,0x20,0xf8]
+[0x20,0x04,0xa0,0xf8]