/src/capstonenext/arch/AArch64/AArch64Disassembler.c

Source
/* Capstone Disassembly Engine, http://www.capstone-engine.org */
/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013-2022, */
/*    Rot127 <unisono@quyllur.org> 2022-2023 */
/* Automatically translated source file from LLVM. */

/* LLVM-commit: <commit> */
/* LLVM-tag: <tag> */

/* Only small edits allowed. */
/* For multiple similar edits, please create a Patch for the translator. */

/* Capstone's C++ file translator: */
/* https://github.com/capstone-engine/capstone/tree/next/suite/auto-sync */

//===- AArch64Disassembler.cpp - Disassembler for AArch64 -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <capstone/platform.h>

#include "../../MCFixedLenDisassembler.h"
#include "../../MCInst.h"
#include "../../MCInstrDesc.h"
#include "../../MCRegisterInfo.h"
#include "../../LEB128.h"
#include "../../MCDisassembler.h"
#include "../../cs_priv.h"
#include "../../utils.h"
#include "AArch64AddressingModes.h"
#include "AArch64BaseInfo.h"
#include "AArch64DisassemblerExtension.h"
#include "AArch64Linkage.h"
#include "AArch64Mapping.h"

#define GET_INSTRINFO_MC_DESC
#include "AArch64GenInstrInfo.inc"

#define CONCAT(a, b) CONCAT_(a, b)
#define CONCAT_(a, b) a##_##b

#define DEBUG_TYPE "aarch64-disassembler"

// Pull DecodeStatus and its enum values into the global namespace.

// Forward declare these because the autogenerated code will reference them.
// Definitions are further down.
static DecodeStatus DecodeFPR128RegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeFPR128_loRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodeFPR128_0to7RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeFPR64RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeFPR32RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeFPR16RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeFPR8RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeGPR64commonRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeGPR64RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeGPR64x8ClassRegisterClass(MCInst *Inst,
                unsigned RegNo,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeGPR64spRegisterClass(MCInst *Inst, unsigned RegNo,
                 uint64_t Address,
                 const void *Decoder);
static DecodeStatus
DecodeMatrixIndexGPR32_8_11RegisterClass(MCInst *Inst, unsigned RegNo,
           uint64_t Address, const void *Decoder);
static DecodeStatus DecodeMatrixIndexGPR32_12_15RegisterClass(
  MCInst *Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
static DecodeStatus DecodeGPR32RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeGPR32spRegisterClass(MCInst *Inst, unsigned RegNo,
                 uint64_t Address,
                 const void *Decoder);
static DecodeStatus DecodeQQRegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeQQQRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodeQQQQRegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeDDRegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeDDDRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodeDDDDRegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeZPRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodeZPR_4bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeZPR_3bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeZPR2RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeZPR3RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeZPR4RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeZPR2Mul2RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeZPR4Mul4RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeZPR2StridedRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeZPR4StridedRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder);
#define DECLARE_DecodeMatrixTile(NumBitsForTile) \
  static DecodeStatus CONCAT(DecodeMatrixTile, NumBitsForTile)( \
    MCInst * Inst, unsigned RegNo, uint64_t Address, \
    const void *Decoder);
DECLARE_DecodeMatrixTile(2);
DECLARE_DecodeMatrixTile(1);
DECLARE_DecodeMatrixTile(3);
DECLARE_DecodeMatrixTile(4);

static DecodeStatus DecodeMatrixTileListRegisterClass(MCInst *Inst,
                  unsigned RegMask,
                  uint64_t Address,
                  const void *Decoder);
static DecodeStatus DecodePPRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodePNRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder);
static DecodeStatus DecodePPR_3bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodePNR_p8to15RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodePPR2RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodePPR2Mul2RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder);

static DecodeStatus DecodeFixedPointScaleImm32(MCInst *Inst, unsigned Imm,
                 uint64_t Address,
                 const void *Decoder);
static DecodeStatus DecodeFixedPointScaleImm64(MCInst *Inst, unsigned Imm,
                 uint64_t Address,
                 const void *Decoder);
static DecodeStatus DecodePCRelLabel16(MCInst *Inst, unsigned Imm,
               uint64_t Address, const void *Decoder);
static DecodeStatus DecodePCRelLabel19(MCInst *Inst, unsigned Imm,
               uint64_t Address, const void *Decoder);
static DecodeStatus DecodeMemExtend(MCInst *Inst, unsigned Imm,
            uint64_t Address, const void *Decoder);
static DecodeStatus DecodeMRSSystemRegister(MCInst *Inst, unsigned Imm,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeMSRSystemRegister(MCInst *Inst, unsigned Imm,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeThreeAddrSRegInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeMoveImmInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeUnsignedLdStInstruction(MCInst *Inst, uint32_t insn,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeSignedLdStInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeExclusiveLdStInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodePairLdStInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeAuthLoadInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeAddSubERegInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeLogicalImmInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeModImmInstruction(MCInst *Inst, uint32_t insn,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeModImmTiedInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Address,
            const void *Decoder);
static DecodeStatus DecodeAdrInstruction(MCInst *Inst, uint32_t insn,
           uint64_t Address, const void *Decoder);
static DecodeStatus DecodeAddSubImmShift(MCInst *Inst, uint32_t insn,
           uint64_t Address, const void *Decoder);
static DecodeStatus DecodeUnconditionalBranch(MCInst *Inst, uint32_t insn,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeSystemPStateImm0_15Instruction(MCInst *Inst,
               uint32_t insn,
               uint64_t Address,
               const void *Decoder);
static DecodeStatus DecodeSystemPStateImm0_1Instruction(MCInst *Inst,
              uint32_t insn,
              uint64_t Address,
              const void *Decoder);
static DecodeStatus DecodeTestAndBranch(MCInst *Inst, uint32_t insn,
          uint64_t Address, const void *Decoder);

static DecodeStatus DecodeFMOVLaneInstruction(MCInst *Inst, unsigned Insn,
                uint64_t Address,
                const void *Decoder);
static DecodeStatus DecodeVecShiftR64Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftR64ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder);
static DecodeStatus DecodeVecShiftR32Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftR32ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder);
static DecodeStatus DecodeVecShiftR16Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftR16ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder);
static DecodeStatus DecodeVecShiftR8Imm(MCInst *Inst, unsigned Imm,
          uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftL64Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftL32Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftL16Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeVecShiftL8Imm(MCInst *Inst, unsigned Imm,
          uint64_t Addr, const void *Decoder);
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);
static DecodeStatus DecodeSyspXzrInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr,
               const void *Decoder);
static DecodeStatus DecodeSVELogicalImmInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Address,
               const void *Decoder);
#define DECLARE_DecodeSImm(Bits) \
  static DecodeStatus CONCAT(DecodeSImm, Bits)(MCInst * Inst, \
                 uint64_t Imm, \
                 uint64_t Address, \
                 const void *Decoder);
DECLARE_DecodeSImm(4);
DECLARE_DecodeSImm(5);
DECLARE_DecodeSImm(6);
DECLARE_DecodeSImm(8);
DECLARE_DecodeSImm(9);
DECLARE_DecodeSImm(10);

#define DECLARE_DecodeImm8OptLsl(ElementWidth) \
  static DecodeStatus CONCAT(DecodeImm8OptLsl, ElementWidth)( \
    MCInst * Inst, unsigned Imm, uint64_t Addr, \
    const void *Decoder);
DECLARE_DecodeImm8OptLsl(8);
DECLARE_DecodeImm8OptLsl(16);
DECLARE_DecodeImm8OptLsl(32);
DECLARE_DecodeImm8OptLsl(64);

static DecodeStatus DecodeSVEIncDecImm(MCInst *Inst, unsigned Imm,
               uint64_t Addr, const void *Decoder);
static DecodeStatus DecodeSVCROp(MCInst *Inst, unsigned Imm, uint64_t Address,
         const void *Decoder);
static DecodeStatus DecodeCPYMemOpInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder);
static DecodeStatus DecodeSETMemOpInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder);
static DecodeStatus DecodePRFMRegInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Address,
               const void *Decoder);

#include "AArch64GenDisassemblerTables.inc"

#define Success MCDisassembler_Success
#define Fail MCDisassembler_Fail
#define SoftFail MCDisassembler_SoftFail

static DecodeStatus getInstruction(csh handle, const uint8_t *Bytes,
           size_t ByteLen, MCInst *MI, uint16_t *Size,
           uint64_t Address, void *Info)
{
  *Size = 0;
  // We want to read exactly 4 bytes of data.
  if (ByteLen < 4)
    return Fail;
  *Size = 4;

  // Encoded as a small-endian 32-bit word in the stream.
  uint32_t Insn = readBytes32(MI, Bytes);

  const uint8_t *Tables[] = { DecoderTable32, DecoderTableFallback32 };

  for (int i = 0; i < (sizeof(Tables) / sizeof(Tables[0])); ++i) {
    void *Decoder = NULL;
    DecodeStatus Result = decodeInstruction_4(Tables[i], MI, Insn,
                Address, Decoder);

    // Table is indexed backwards
    const MCInstrDesc Desc =
      AArch64Descs.Insts[ARR_SIZE(AArch64Descs.Insts) - 1 -
             MCInst_getOpcode(MI)];

    // For Scalable Matrix Extension (SME) instructions that have an
    // implicit operand for the accumulator (ZA) or implicit immediate zero
    // which isn't encoded, manually insert operand.
    for (unsigned j = 0; j < Desc.NumOperands; j++) {
      if (Desc.OpInfo[j].OperandType ==
          MCOI_OPERAND_REGISTER) {
        switch (Desc.OpInfo[j].RegClass) {
        default:
          break;
        case AArch64_MPRRegClassID:
          MCInst_insert0(MI, j,
                   MCOperand_CreateReg1(
                     MI, AArch64_ZA));
          break;
        case AArch64_MPR8RegClassID:
          MCInst_insert0(MI, j,
                   MCOperand_CreateReg1(
                     MI,
                     AArch64_ZAB0));
          break;
        case AArch64_ZTRRegClassID:
          MCInst_insert0(MI, j,
                   MCOperand_CreateReg1(
                     MI,
                     AArch64_ZT0));
          break;
        }
      } else if (Desc.OpInfo[j].OperandType ==
           AARCH64_OP_IMPLICIT_IMM_0) {
        MCInst_insert0(MI, j,
                 MCOperand_CreateImm1(MI, 0));
      }
    }

    if (MCInst_getOpcode(MI) == AArch64_LDR_ZA ||
        MCInst_getOpcode(MI) == AArch64_STR_ZA) {
      // Spill and fill instructions have a single immediate used for both
      // the vector select offset and optional memory offset. Replicate
      // the decoded immediate.
      MCOperand *Imm4Op = MCInst_getOperand(MI, (2));

      MCInst_addOperand2(MI, (Imm4Op));
    }

    if (Result != MCDisassembler_Fail)
      return Result;
  }

  return MCDisassembler_Fail;
}

DecodeStatus AArch64_LLVM_getInstruction(csh handle, const uint8_t *Bytes,
           size_t ByteLen, MCInst *MI,
           uint16_t *Size, uint64_t Address,
           void *Info)
{
  DecodeStatus Result = MCDisassembler_Fail;
  Result =
    getInstruction(handle, Bytes, ByteLen, MI, Size, Address, Info);
  MCInst_handleWriteback(MI, AArch64Descs.Insts,
             ARR_SIZE(AArch64Descs.Insts));
  return Result;
}

uint64_t suggestBytesToSkip(const uint8_t *Bytes, uint64_t Address)
{
  // AArch64 instructions are always 4 bytes wide, so there's no point
  // in skipping any smaller number of bytes if an instruction can't
  // be decoded.
  return 4;
}

static DecodeStatus DecodeFPR128RegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Addr,
                const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_FPR128RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeFPR128_loRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Addr,
             const void *Decoder)
{
  if (RegNo > 15)
    return Fail;
  return DecodeFPR128RegisterClass(Inst, RegNo, Addr, Decoder);
}

static DecodeStatus DecodeFPR128_0to7RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr,
               const void *Decoder)
{
  if (RegNo > 7)
    return Fail;
  return DecodeFPR128RegisterClass(Inst, RegNo, Addr, Decoder);
}

static DecodeStatus DecodeFPR64RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_FPR64RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeFPR32RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_FPR32RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeFPR16RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_FPR16RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeFPR8RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_FPR8RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR64commonRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr,
               const void *Decoder)
{
  if (RegNo > 30)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_GPR64commonRegClassID]
      .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR64RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_GPR64RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR64x8ClassRegisterClass(MCInst *Inst,
                unsigned RegNo,
                uint64_t Address,
                const void *Decoder)
{
  if (RegNo > 22)
    return Fail;
  if (RegNo & 1)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_GPR64x8ClassRegClassID]
      .RegsBegin[RegNo >> 1];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR64spRegisterClass(MCInst *Inst, unsigned RegNo,
                 uint64_t Addr,
                 const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_GPR64spRegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus
DecodeMatrixIndexGPR32_8_11RegisterClass(MCInst *Inst, unsigned RegNo,
           uint64_t Addr, const void *Decoder)
{
  if (RegNo > 3)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_MatrixIndexGPR32_8_11RegClassID]
      .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus
DecodeMatrixIndexGPR32_12_15RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Addr, const void *Decoder)
{
  if (RegNo > 3)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_MatrixIndexGPR32_12_15RegClassID]
      .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR32RegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_GPR32RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeGPR32spRegisterClass(MCInst *Inst, unsigned RegNo,
                 uint64_t Addr,
                 const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_GPR32spRegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Address,
             const void *Decoder)
{
  if (RegNo > 31)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_ZPRRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR_4bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder)
{
  if (RegNo > 15)
    return Fail;
  return DecodeZPRRegisterClass(Inst, RegNo, Address, Decoder);
}

static DecodeStatus DecodeZPR_3bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Address,
                const void *Decoder)
{
  if (RegNo > 7)
    return Fail;
  return DecodeZPRRegisterClass(Inst, RegNo, Address, Decoder);
}

static DecodeStatus DecodeZPR2RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_ZPR2RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR3RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_ZPR3RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR4RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_ZPR4RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR2Mul2RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder)
{
  if (RegNo * 2 > 30)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_ZPR2RegClassID]
            .RegsBegin[RegNo * 2];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR4Mul4RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder)
{
  if (RegNo * 4 > 28)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_ZPR4RegClassID]
            .RegsBegin[RegNo * 4];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR2StridedRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder)
{
  if (RegNo > 15)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_ZPR2StridedRegClassID]
      .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeZPR4StridedRegisterClass(MCInst *Inst, unsigned RegNo,
               uint64_t Address,
               const void *Decoder)
{
  if (RegNo > 7)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_ZPR4StridedRegClassID]
      .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeMatrixTileListRegisterClass(MCInst *Inst,
                  unsigned RegMask,
                  uint64_t Address,
                  const void *Decoder)
{
  if (RegMask > 0xFF)
    return Fail;
  MCOperand_CreateImm0(Inst, (RegMask));
  return Success;
}

static const MCPhysReg MatrixZATileDecoderTable[5][16] = {
  { AArch64_ZAB0 },
  { AArch64_ZAH0, AArch64_ZAH1 },
  { AArch64_ZAS0, AArch64_ZAS1, AArch64_ZAS2, AArch64_ZAS3 },
  { AArch64_ZAD0, AArch64_ZAD1, AArch64_ZAD2, AArch64_ZAD3, AArch64_ZAD4,
    AArch64_ZAD5, AArch64_ZAD6, AArch64_ZAD7 },
  { AArch64_ZAQ0, AArch64_ZAQ1, AArch64_ZAQ2, AArch64_ZAQ3, AArch64_ZAQ4,
    AArch64_ZAQ5, AArch64_ZAQ6, AArch64_ZAQ7, AArch64_ZAQ8, AArch64_ZAQ9,
    AArch64_ZAQ10, AArch64_ZAQ11, AArch64_ZAQ12, AArch64_ZAQ13,
    AArch64_ZAQ14, AArch64_ZAQ15 }
};

#define DEFINE_DecodeMatrixTile(NumBitsForTile) \
  static DecodeStatus CONCAT(DecodeMatrixTile, NumBitsForTile)( \
    MCInst * Inst, unsigned RegNo, uint64_t Address, \
    const void *Decoder) \
  { \
    unsigned LastReg = (1 << NumBitsForTile) - 1; \
    if (RegNo > LastReg) \
      return Fail; \
    MCOperand_CreateReg0( \
      Inst, \
      (MatrixZATileDecoderTable[NumBitsForTile][RegNo])); \
    return Success; \
  }
DEFINE_DecodeMatrixTile(2);
DEFINE_DecodeMatrixTile(1);
DEFINE_DecodeMatrixTile(3);
DEFINE_DecodeMatrixTile(4);

static DecodeStatus DecodePPRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Addr, const void *Decoder)
{
  if (RegNo > 15)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_PPRRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodePNRRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Addr, const void *Decoder)
{
  if (RegNo > 15)
    return Fail;

  unsigned Register =
    AArch64MCRegisterClasses[AArch64_PNRRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodePPR_3bRegisterClass(MCInst *Inst, unsigned RegNo,
                uint64_t Addr,
                const void *Decoder)
{
  if (RegNo > 7)
    return Fail;

  // Just reuse the PPR decode table
  return DecodePPRRegisterClass(Inst, RegNo, Addr, Decoder);
}

static DecodeStatus DecodePNR_p8to15RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Addr,
              const void *Decoder)
{
  if (RegNo > 7)
    return Fail;

  // Just reuse the PPR decode table
  return DecodePNRRegisterClass(Inst, RegNo + 8, Addr, Decoder);
}

static DecodeStatus DecodePPR2RegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Address,
              const void *Decoder)
{
  if (RegNo > 15)
    return Fail;

  unsigned Register = AArch64MCRegisterClasses[AArch64_PPR2RegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodePPR2Mul2RegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Address,
            const void *Decoder)
{
  if ((RegNo * 2) > 14)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_PPR2RegClassID]
            .RegsBegin[RegNo * 2];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeQQRegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_QQRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeQQQRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_QQQRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeQQQQRegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_QQQQRegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeDDRegisterClass(MCInst *Inst, unsigned RegNo,
            uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_DDRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeDDDRegisterClass(MCInst *Inst, unsigned RegNo,
             uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register =
    AArch64MCRegisterClasses[AArch64_DDDRegClassID].RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeDDDDRegisterClass(MCInst *Inst, unsigned RegNo,
              uint64_t Addr, const void *Decoder)
{
  if (RegNo > 31)
    return Fail;
  unsigned Register = AArch64MCRegisterClasses[AArch64_DDDDRegClassID]
            .RegsBegin[RegNo];
  MCOperand_CreateReg0(Inst, (Register));
  return Success;
}

static DecodeStatus DecodeFixedPointScaleImm32(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder)
{
  // scale{5} is asserted as 1 in tblgen.
  Imm |= 0x20;
  MCOperand_CreateImm0(Inst, (64 - Imm));
  return Success;
}

static DecodeStatus DecodeFixedPointScaleImm64(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder)
{
  MCOperand_CreateImm0(Inst, (64 - Imm));
  return Success;
}

static DecodeStatus DecodePCRelLabel16(MCInst *Inst, unsigned Imm,
               uint64_t Addr, const void *Decoder)
{
  // Immediate is encoded as the top 16-bits of an unsigned 18-bit negative
  // PC-relative offset.
  uint64_t ImmVal = Imm;
  if (ImmVal > (1 << 16))
    return Fail;
  // Symbols are not supported by Capstone
  return Success;
}

static DecodeStatus DecodePCRelLabel19(MCInst *Inst, unsigned Imm,
               uint64_t Addr, const void *Decoder)
{
  int64_t ImmVal = Imm;

  // Sign-extend 19-bit immediate.
  if (ImmVal & (1 << (19 - 1)))
    ImmVal |= ~((1LL << 19) - 1);

  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(
  //    Inst, ImmVal * 4, Addr, MCInst_getOpcode(Inst) != AArch64_LDRXl, 0,
  //    0, 4))
  MCOperand_CreateImm0(Inst, (ImmVal));
  return Success;
}

static DecodeStatus DecodeMemExtend(MCInst *Inst, unsigned Imm,
            uint64_t Address, const void *Decoder)
{
  MCOperand_CreateImm0(Inst, ((Imm >> 1) & 1));
  MCOperand_CreateImm0(Inst, (Imm & 1));
  return Success;
}

static DecodeStatus DecodeMRSSystemRegister(MCInst *Inst, unsigned Imm,
              uint64_t Address,
              const void *Decoder)
{
  MCOperand_CreateImm0(Inst, (Imm));

  // Every system register in the encoding space is valid with the syntax
  // S<op0>_<op1>_<Cn>_<Cm>_<op2>, so decoding system registers always
  // succeeds.
  return Success;
}

static DecodeStatus DecodeMSRSystemRegister(MCInst *Inst, unsigned Imm,
              uint64_t Address,
              const void *Decoder)
{
  MCOperand_CreateImm0(Inst, (Imm));

  return Success;
}

static DecodeStatus DecodeFMOVLaneInstruction(MCInst *Inst, unsigned Insn,
                uint64_t Address,
                const void *Decoder)
{
  // This decoder exists to add the dummy Lane operand to the MCInst, which
  // must be 1 in assembly but has no other real manifestation.
  unsigned Rd = fieldFromInstruction_4(Insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(Insn, 5, 5);
  unsigned IsToVec = fieldFromInstruction_4(Insn, 16, 1);

  if (IsToVec) {
    DecodeFPR128RegisterClass(Inst, Rd, Address, Decoder);
    DecodeGPR64RegisterClass(Inst, Rn, Address, Decoder);
  } else {
    DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder);
    DecodeFPR128RegisterClass(Inst, Rn, Address, Decoder);
  }

  // Add the lane
  MCOperand_CreateImm0(Inst, (1));

  return Success;
}

static DecodeStatus DecodeVecShiftRImm(MCInst *Inst, unsigned Imm, unsigned Add)
{
  MCOperand_CreateImm0(Inst, (Add - Imm));
  return Success;
}

static DecodeStatus DecodeVecShiftLImm(MCInst *Inst, unsigned Imm, unsigned Add)
{
  MCOperand_CreateImm0(Inst, ((Imm + Add) & (Add - 1)));
  return Success;
}

static DecodeStatus DecodeVecShiftR64Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm, 64);
}

static DecodeStatus DecodeVecShiftR64ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm | 0x20, 64);
}

static DecodeStatus DecodeVecShiftR32Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm, 32);
}

static DecodeStatus DecodeVecShiftR32ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm | 0x10, 32);
}

static DecodeStatus DecodeVecShiftR16Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm, 16);
}

static DecodeStatus DecodeVecShiftR16ImmNarrow(MCInst *Inst, unsigned Imm,
                 uint64_t Addr,
                 const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm | 0x8, 16);
}

static DecodeStatus DecodeVecShiftR8Imm(MCInst *Inst, unsigned Imm,
          uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftRImm(Inst, Imm, 8);
}

static DecodeStatus DecodeVecShiftL64Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftLImm(Inst, Imm, 64);
}

static DecodeStatus DecodeVecShiftL32Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftLImm(Inst, Imm, 32);
}

static DecodeStatus DecodeVecShiftL16Imm(MCInst *Inst, unsigned Imm,
           uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftLImm(Inst, Imm, 16);
}

static DecodeStatus DecodeVecShiftL8Imm(MCInst *Inst, unsigned Imm,
          uint64_t Addr, const void *Decoder)
{
  return DecodeVecShiftLImm(Inst, Imm, 8);
}

static DecodeStatus DecodeThreeAddrSRegInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr,
               const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Rm = fieldFromInstruction_4(insn, 16, 5);
  unsigned shiftHi = fieldFromInstruction_4(insn, 22, 2);
  unsigned shiftLo = fieldFromInstruction_4(insn, 10, 6);
  unsigned shift = (shiftHi << 6) | shiftLo;
  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_ADDWrs:
  case AArch64_ADDSWrs:
  case AArch64_SUBWrs:
  case AArch64_SUBSWrs:
    // if shift == '11' then ReservedValue()
    if (shiftHi == 0x3)
      return Fail;
    // fall through
  case AArch64_ANDWrs:
  case AArch64_ANDSWrs:
  case AArch64_BICWrs:
  case AArch64_BICSWrs:
  case AArch64_ORRWrs:
  case AArch64_ORNWrs:
  case AArch64_EORWrs:
  case AArch64_EONWrs: {
    // if sf == '0' and imm6<5> == '1' then ReservedValue()
    if (shiftLo >> 5 == 1)
      return Fail;
    DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  }
  case AArch64_ADDXrs:
  case AArch64_ADDSXrs:
  case AArch64_SUBXrs:
  case AArch64_SUBSXrs:
    // if shift == '11' then ReservedValue()
    if (shiftHi == 0x3)
      return Fail;
    // fall through
  case AArch64_ANDXrs:
  case AArch64_ANDSXrs:
  case AArch64_BICXrs:
  case AArch64_BICSXrs:
  case AArch64_ORRXrs:
  case AArch64_ORNXrs:
  case AArch64_EORXrs:
  case AArch64_EONXrs:
    DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  }

  MCOperand_CreateImm0(Inst, (shift));
  return Success;
}

static DecodeStatus DecodeMoveImmInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr, const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned imm = fieldFromInstruction_4(insn, 5, 16);
  unsigned shift = fieldFromInstruction_4(insn, 21, 2);
  shift <<= 4;
  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_MOVZWi:
  case AArch64_MOVNWi:
  case AArch64_MOVKWi:
    if (shift & (1U << 5))
      return Fail;
    DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
    break;
  case AArch64_MOVZXi:
  case AArch64_MOVNXi:
  case AArch64_MOVKXi:
    DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    break;
  }

  if (MCInst_getOpcode(Inst) == AArch64_MOVKWi ||
      MCInst_getOpcode(Inst) == AArch64_MOVKXi)
    MCInst_addOperand2(Inst, (MCInst_getOperand(Inst, (0))));

  MCOperand_CreateImm0(Inst, (imm));
  MCOperand_CreateImm0(Inst, (shift));
  return Success;
}

static DecodeStatus DecodeUnsignedLdStInstruction(MCInst *Inst, uint32_t insn,
              uint64_t Addr,
              const void *Decoder)
{
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned offset = fieldFromInstruction_4(insn, 10, 12);

  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_PRFMui:
    // Rt is an immediate in prefetch.
    MCOperand_CreateImm0(Inst, (Rt));
    break;
  case AArch64_STRBBui:
  case AArch64_LDRBBui:
  case AArch64_LDRSBWui:
  case AArch64_STRHHui:
  case AArch64_LDRHHui:
  case AArch64_LDRSHWui:
  case AArch64_STRWui:
  case AArch64_LDRWui:
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRSBXui:
  case AArch64_LDRSHXui:
  case AArch64_LDRSWui:
  case AArch64_STRXui:
  case AArch64_LDRXui:
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRQui:
  case AArch64_STRQui:
    DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRDui:
  case AArch64_STRDui:
    DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRSui:
  case AArch64_STRSui:
    DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRHui:
  case AArch64_STRHui:
    DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDRBui:
  case AArch64_STRBui:
    DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  }

  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(Inst, offset, Addr, Fail, 0, 0, 4))
  MCOperand_CreateImm0(Inst, (offset));
  return Success;
}

static DecodeStatus DecodeSignedLdStInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Addr,
            const void *Decoder)
{
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  int64_t offset = fieldFromInstruction_4(insn, 12, 9);

  // offset is a 9-bit signed immediate, so sign extend it to
  // fill the unsigned.
  if (offset & (1 << (9 - 1)))
    offset |= ~((1LL << 9) - 1);

  // First operand is always the writeback to the address register, if needed.
  switch (MCInst_getOpcode(Inst)) {
  default:
    break;
  case AArch64_LDRSBWpre:
  case AArch64_LDRSHWpre:
  case AArch64_STRBBpre:
  case AArch64_LDRBBpre:
  case AArch64_STRHHpre:
  case AArch64_LDRHHpre:
  case AArch64_STRWpre:
  case AArch64_LDRWpre:
  case AArch64_LDRSBWpost:
  case AArch64_LDRSHWpost:
  case AArch64_STRBBpost:
  case AArch64_LDRBBpost:
  case AArch64_STRHHpost:
  case AArch64_LDRHHpost:
  case AArch64_STRWpost:
  case AArch64_LDRWpost:
  case AArch64_LDRSBXpre:
  case AArch64_LDRSHXpre:
  case AArch64_STRXpre:
  case AArch64_LDRSWpre:
  case AArch64_LDRXpre:
  case AArch64_LDRSBXpost:
  case AArch64_LDRSHXpost:
  case AArch64_STRXpost:
  case AArch64_LDRSWpost:
  case AArch64_LDRXpost:
  case AArch64_LDRQpre:
  case AArch64_STRQpre:
  case AArch64_LDRQpost:
  case AArch64_STRQpost:
  case AArch64_LDRDpre:
  case AArch64_STRDpre:
  case AArch64_LDRDpost:
  case AArch64_STRDpost:
  case AArch64_LDRSpre:
  case AArch64_STRSpre:
  case AArch64_LDRSpost:
  case AArch64_STRSpost:
  case AArch64_LDRHpre:
  case AArch64_STRHpre:
  case AArch64_LDRHpost:
  case AArch64_STRHpost:
  case AArch64_LDRBpre:
  case AArch64_STRBpre:
  case AArch64_LDRBpost:
  case AArch64_STRBpost:
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    break;
  }

  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_PRFUMi:
    // Rt is an immediate in prefetch.
    MCOperand_CreateImm0(Inst, (Rt));
    break;
  case AArch64_STURBBi:
  case AArch64_LDURBBi:
  case AArch64_LDURSBWi:
  case AArch64_STURHHi:
  case AArch64_LDURHHi:
  case AArch64_LDURSHWi:
  case AArch64_STURWi:
  case AArch64_LDURWi:
  case AArch64_LDTRSBWi:
  case AArch64_LDTRSHWi:
  case AArch64_STTRWi:
  case AArch64_LDTRWi:
  case AArch64_STTRHi:
  case AArch64_LDTRHi:
  case AArch64_LDTRBi:
  case AArch64_STTRBi:
  case AArch64_LDRSBWpre:
  case AArch64_LDRSHWpre:
  case AArch64_STRBBpre:
  case AArch64_LDRBBpre:
  case AArch64_STRHHpre:
  case AArch64_LDRHHpre:
  case AArch64_STRWpre:
  case AArch64_LDRWpre:
  case AArch64_LDRSBWpost:
  case AArch64_LDRSHWpost:
  case AArch64_STRBBpost:
  case AArch64_LDRBBpost:
  case AArch64_STRHHpost:
  case AArch64_LDRHHpost:
  case AArch64_STRWpost:
  case AArch64_LDRWpost:
  case AArch64_STLURBi:
  case AArch64_STLURHi:
  case AArch64_STLURWi:
  case AArch64_LDAPURBi:
  case AArch64_LDAPURSBWi:
  case AArch64_LDAPURHi:
  case AArch64_LDAPURSHWi:
  case AArch64_LDAPURi:
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURSBXi:
  case AArch64_LDURSHXi:
  case AArch64_LDURSWi:
  case AArch64_STURXi:
  case AArch64_LDURXi:
  case AArch64_LDTRSBXi:
  case AArch64_LDTRSHXi:
  case AArch64_LDTRSWi:
  case AArch64_STTRXi:
  case AArch64_LDTRXi:
  case AArch64_LDRSBXpre:
  case AArch64_LDRSHXpre:
  case AArch64_STRXpre:
  case AArch64_LDRSWpre:
  case AArch64_LDRXpre:
  case AArch64_LDRSBXpost:
  case AArch64_LDRSHXpost:
  case AArch64_STRXpost:
  case AArch64_LDRSWpost:
  case AArch64_LDRXpost:
  case AArch64_LDAPURSWi:
  case AArch64_LDAPURSHXi:
  case AArch64_LDAPURSBXi:
  case AArch64_STLURXi:
  case AArch64_LDAPURXi:
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURQi:
  case AArch64_STURQi:
  case AArch64_LDRQpre:
  case AArch64_STRQpre:
  case AArch64_LDRQpost:
  case AArch64_STRQpost:
    DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURDi:
  case AArch64_STURDi:
  case AArch64_LDRDpre:
  case AArch64_STRDpre:
  case AArch64_LDRDpost:
  case AArch64_STRDpost:
    DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURSi:
  case AArch64_STURSi:
  case AArch64_LDRSpre:
  case AArch64_STRSpre:
  case AArch64_LDRSpost:
  case AArch64_STRSpost:
    DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURHi:
  case AArch64_STURHi:
  case AArch64_LDRHpre:
  case AArch64_STRHpre:
  case AArch64_LDRHpost:
  case AArch64_STRHpost:
    DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_LDURBi:
  case AArch64_STURBi:
  case AArch64_LDRBpre:
  case AArch64_STRBpre:
  case AArch64_LDRBpost:
  case AArch64_STRBpost:
    DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  }

  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
  MCOperand_CreateImm0(Inst, (offset));

  bool IsLoad = fieldFromInstruction_4(insn, 22, 1);
  bool IsIndexed = fieldFromInstruction_4(insn, 10, 2) != 0;
  bool IsFP = fieldFromInstruction_4(insn, 26, 1);

  // Cannot write back to a transfer register (but xzr != sp).
  if (IsLoad && IsIndexed && !IsFP && Rn != 31 && Rt == Rn)
    return SoftFail;

  return Success;
}

static DecodeStatus DecodeExclusiveLdStInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr,
               const void *Decoder)
{
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Rt2 = fieldFromInstruction_4(insn, 10, 5);
  unsigned Rs = fieldFromInstruction_4(insn, 16, 5);

  unsigned Opcode = MCInst_getOpcode(Inst);
  switch (Opcode) {
  default:
    return Fail;
  case AArch64_STLXRW:
  case AArch64_STLXRB:
  case AArch64_STLXRH:
  case AArch64_STXRW:
  case AArch64_STXRB:
  case AArch64_STXRH:
    DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
    // fall through
  case AArch64_LDARW:
  case AArch64_LDARB:
  case AArch64_LDARH:
  case AArch64_LDAXRW:
  case AArch64_LDAXRB:
  case AArch64_LDAXRH:
  case AArch64_LDXRW:
  case AArch64_LDXRB:
  case AArch64_LDXRH:
  case AArch64_STLRW:
  case AArch64_STLRB:
  case AArch64_STLRH:
  case AArch64_STLLRW:
  case AArch64_STLLRB:
  case AArch64_STLLRH:
  case AArch64_LDLARW:
  case AArch64_LDLARB:
  case AArch64_LDLARH:
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_STLXRX:
  case AArch64_STXRX:
    DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
    // fall through
  case AArch64_LDARX:
  case AArch64_LDAXRX:
  case AArch64_LDXRX:
  case AArch64_STLRX:
  case AArch64_LDLARX:
  case AArch64_STLLRX:
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
    break;
  case AArch64_STLXPW:
  case AArch64_STXPW:
    DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
    // fall through
  case AArch64_LDAXPW:
  case AArch64_LDXPW:
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  case AArch64_STLXPX:
  case AArch64_STXPX:
    DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
    // fall through
  case AArch64_LDAXPX:
  case AArch64_LDXPX:
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  }

  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);

  // You shouldn't load to the same register twice in an instruction...
  if ((Opcode == AArch64_LDAXPW || Opcode == AArch64_LDXPW ||
       Opcode == AArch64_LDAXPX || Opcode == AArch64_LDXPX) &&
      Rt == Rt2)
    return SoftFail;

  return Success;
}

static DecodeStatus DecodePairLdStInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder)
{
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Rt2 = fieldFromInstruction_4(insn, 10, 5);
  int64_t offset = fieldFromInstruction_4(insn, 15, 7);
  bool IsLoad = fieldFromInstruction_4(insn, 22, 1);

  // offset is a 7-bit signed immediate, so sign extend it to
  // fill the unsigned.
  if (offset & (1 << (7 - 1)))
    offset |= ~((1LL << 7) - 1);

  unsigned Opcode = MCInst_getOpcode(Inst);
  bool NeedsDisjointWritebackTransfer = false;

  // First operand is always writeback of base register.
  switch (Opcode) {
  default:
    break;
  case AArch64_LDPXpost:
  case AArch64_STPXpost:
  case AArch64_LDPSWpost:
  case AArch64_LDPXpre:
  case AArch64_STPXpre:
  case AArch64_LDPSWpre:
  case AArch64_LDPWpost:
  case AArch64_STPWpost:
  case AArch64_LDPWpre:
  case AArch64_STPWpre:
  case AArch64_LDPQpost:
  case AArch64_STPQpost:
  case AArch64_LDPQpre:
  case AArch64_STPQpre:
  case AArch64_LDPDpost:
  case AArch64_STPDpost:
  case AArch64_LDPDpre:
  case AArch64_STPDpre:
  case AArch64_LDPSpost:
  case AArch64_STPSpost:
  case AArch64_LDPSpre:
  case AArch64_STPSpre:
  case AArch64_STGPpre:
  case AArch64_STGPpost:
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    break;
  }

  switch (Opcode) {
  default:
    return Fail;
  case AArch64_LDPXpost:
  case AArch64_STPXpost:
  case AArch64_LDPSWpost:
  case AArch64_LDPXpre:
  case AArch64_STPXpre:
  case AArch64_LDPSWpre:
  case AArch64_STGPpre:
  case AArch64_STGPpost:
    NeedsDisjointWritebackTransfer = true;
    // fall through
  case AArch64_LDNPXi:
  case AArch64_STNPXi:
  case AArch64_LDPXi:
  case AArch64_STPXi:
  case AArch64_LDPSWi:
  case AArch64_STGPi:
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  case AArch64_LDPWpost:
  case AArch64_STPWpost:
  case AArch64_LDPWpre:
  case AArch64_STPWpre:
    NeedsDisjointWritebackTransfer = true;
    // fall through
  case AArch64_LDNPWi:
  case AArch64_STNPWi:
  case AArch64_LDPWi:
  case AArch64_STPWi:
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  case AArch64_LDNPQi:
  case AArch64_STNPQi:
  case AArch64_LDPQpost:
  case AArch64_STPQpost:
  case AArch64_LDPQi:
  case AArch64_STPQi:
  case AArch64_LDPQpre:
  case AArch64_STPQpre:
    DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeFPR128RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  case AArch64_LDNPDi:
  case AArch64_STNPDi:
  case AArch64_LDPDpost:
  case AArch64_STPDpost:
  case AArch64_LDPDi:
  case AArch64_STPDi:
  case AArch64_LDPDpre:
  case AArch64_STPDpre:
    DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeFPR64RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  case AArch64_LDNPSi:
  case AArch64_STNPSi:
  case AArch64_LDPSpost:
  case AArch64_STPSpost:
  case AArch64_LDPSi:
  case AArch64_STPSi:
  case AArch64_LDPSpre:
  case AArch64_STPSpre:
    DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
    DecodeFPR32RegisterClass(Inst, Rt2, Addr, Decoder);
    break;
  }

  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
  MCOperand_CreateImm0(Inst, (offset));

  // You shouldn't load to the same register twice in an instruction...
  if (IsLoad && Rt == Rt2)
    return SoftFail;

  // ... or do any operation that writes-back to a transfer register. But note
  // that "stp xzr, xzr, [sp], #4" is fine because xzr and sp are different.
  if (NeedsDisjointWritebackTransfer && Rn != 31 &&
      (Rt == Rn || Rt2 == Rn))
    return SoftFail;

  return Success;
}

static DecodeStatus DecodeAuthLoadInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder)
{
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  uint64_t offset = fieldFromInstruction_4(insn, 22, 1) << 9 |
        fieldFromInstruction_4(insn, 12, 9);
  unsigned writeback = fieldFromInstruction_4(insn, 11, 1);

  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_LDRAAwriteback:
  case AArch64_LDRABwriteback:
    DecodeGPR64spRegisterClass(Inst, Rn /* writeback register */,
             Addr, Decoder);
    break;
  case AArch64_LDRAAindexed:
  case AArch64_LDRABindexed:
    break;
  }

  DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
  CONCAT(DecodeSImm, 10)(Inst, offset, Addr, Decoder);

  if (writeback && Rt == Rn && Rn != 31) {
    return SoftFail;
  }

  return Success;
}

static DecodeStatus DecodeAddSubERegInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Addr,
            const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Rm = fieldFromInstruction_4(insn, 16, 5);
  unsigned extend = fieldFromInstruction_4(insn, 10, 6);

  unsigned shift = extend & 0x7;
  if (shift > 4)
    return Fail;

  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_ADDWrx:
  case AArch64_SUBWrx:
    DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_ADDSWrx:
  case AArch64_SUBSWrx:
    DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_ADDXrx:
  case AArch64_SUBXrx:
    DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_ADDSXrx:
  case AArch64_SUBSXrx:
    DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_ADDXrx64:
  case AArch64_SUBXrx64:
    DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_SUBSXrx64:
  case AArch64_ADDSXrx64:
    DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  }

  MCOperand_CreateImm0(Inst, (extend));
  return Success;
}

static DecodeStatus DecodeLogicalImmInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Addr,
            const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Datasize = fieldFromInstruction_4(insn, 31, 1);
  unsigned imm;

  if (Datasize) {
    if (MCInst_getOpcode(Inst) == AArch64_ANDSXri)
      DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    else
      DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
    imm = fieldFromInstruction_4(insn, 10, 13);
    if (!AArch64_AM_isValidDecodeLogicalImmediate(imm, 64))
      return Fail;
  } else {
    if (MCInst_getOpcode(Inst) == AArch64_ANDSWri)
      DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
    else
      DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
    imm = fieldFromInstruction_4(insn, 10, 12);
    if (!AArch64_AM_isValidDecodeLogicalImmediate(imm, 32))
      return Fail;
  }
  MCOperand_CreateImm0(Inst, (imm));
  return Success;
}

static DecodeStatus DecodeModImmInstruction(MCInst *Inst, uint32_t insn,
              uint64_t Addr, const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned cmode = fieldFromInstruction_4(insn, 12, 4);
  unsigned imm = fieldFromInstruction_4(insn, 16, 3) << 5;
  imm |= fieldFromInstruction_4(insn, 5, 5);

  if (MCInst_getOpcode(Inst) == AArch64_MOVID)
    DecodeFPR64RegisterClass(Inst, Rd, Addr, Decoder);
  else
    DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);

  MCOperand_CreateImm0(Inst, (imm));

  switch (MCInst_getOpcode(Inst)) {
  default:
    break;
  case AArch64_MOVIv4i16:
  case AArch64_MOVIv8i16:
  case AArch64_MVNIv4i16:
  case AArch64_MVNIv8i16:
  case AArch64_MOVIv2i32:
  case AArch64_MOVIv4i32:
  case AArch64_MVNIv2i32:
  case AArch64_MVNIv4i32:
    MCOperand_CreateImm0(Inst, ((cmode & 6) << 2));
    break;
  case AArch64_MOVIv2s_msl:
  case AArch64_MOVIv4s_msl:
  case AArch64_MVNIv2s_msl:
  case AArch64_MVNIv4s_msl:
    MCOperand_CreateImm0(Inst, ((cmode & 1) ? 0x110 : 0x108));
    break;
  }

  return Success;
}

static DecodeStatus DecodeModImmTiedInstruction(MCInst *Inst, uint32_t insn,
            uint64_t Addr,
            const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned cmode = fieldFromInstruction_4(insn, 12, 4);
  unsigned imm = fieldFromInstruction_4(insn, 16, 3) << 5;
  imm |= fieldFromInstruction_4(insn, 5, 5);

  // Tied operands added twice.
  DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);
  DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);

  MCOperand_CreateImm0(Inst, (imm));
  MCOperand_CreateImm0(Inst, ((cmode & 6) << 2));

  return Success;
}

static DecodeStatus DecodeAdrInstruction(MCInst *Inst, uint32_t insn,
           uint64_t Addr, const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  int64_t imm = fieldFromInstruction_4(insn, 5, 19) << 2;
  imm |= fieldFromInstruction_4(insn, 29, 2);

  // Sign-extend the 21-bit immediate.
  if (imm & (1 << (21 - 1)))
    imm |= ~((1LL << 21) - 1);

  DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(Inst, imm, Addr, Fail, 0, 0, 4))
  MCOperand_CreateImm0(Inst, (imm));

  return Success;
}

static DecodeStatus DecodeAddSubImmShift(MCInst *Inst, uint32_t insn,
           uint64_t Addr, const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);
  unsigned Imm = fieldFromInstruction_4(insn, 10, 14);
  unsigned S = fieldFromInstruction_4(insn, 29, 1);
  unsigned Datasize = fieldFromInstruction_4(insn, 31, 1);

  unsigned ShifterVal = (Imm >> 12) & 3;
  unsigned ImmVal = Imm & 0xFFF;

  if (ShifterVal != 0 && ShifterVal != 1)
    return Fail;

  if (Datasize) {
    if (Rd == 31 && !S)
      DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
    else
      DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
  } else {
    if (Rd == 31 && !S)
      DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
    else
      DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
    DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
  }

  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(Inst, Imm, Addr, Fail, 0, 0, 4))
  MCOperand_CreateImm0(Inst, (ImmVal));
  MCOperand_CreateImm0(Inst, (12 * ShifterVal));
  return Success;
}

static DecodeStatus DecodeUnconditionalBranch(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder)
{
  int64_t imm = fieldFromInstruction_4(insn, 0, 26);

  // Sign-extend the 26-bit immediate.
  if (imm & (1 << (26 - 1)))
    imm |= ~((1LL << 26) - 1);

  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(Inst, imm * 4, Addr, true, 0, 0, 4))
  MCOperand_CreateImm0(Inst, (imm));

  return Success;
}

static bool isInvalidPState(uint64_t Op1, uint64_t Op2)
{
  return Op1 == 0 && (Op2 == 0 || // CFINV
          Op2 == 1 || // XAFlag
          Op2 == 2); // AXFlag
}

static DecodeStatus DecodeSystemPStateImm0_15Instruction(MCInst *Inst,
               uint32_t insn,
               uint64_t Addr,
               const void *Decoder)
{
  uint64_t op1 = fieldFromInstruction_4(insn, 16, 3);
  uint64_t op2 = fieldFromInstruction_4(insn, 5, 3);
  uint64_t imm = fieldFromInstruction_4(insn, 8, 4);
  uint64_t pstate_field = (op1 << 3) | op2;

  if (isInvalidPState(op1, op2))
    return Fail;

  MCOperand_CreateImm0(Inst, (pstate_field));
  MCOperand_CreateImm0(Inst, (imm));

  const AArch64PState_PStateImm0_15 *PState =
    AArch64PState_lookupPStateImm0_15ByEncoding(pstate_field);
  if (PState &&
      AArch64_testFeatureList(Inst->csh->mode, PState->FeaturesRequired))
    return Success;
  return Fail;
}

static DecodeStatus DecodeSystemPStateImm0_1Instruction(MCInst *Inst,
              uint32_t insn,
              uint64_t Addr,
              const void *Decoder)
{
  uint64_t op1 = fieldFromInstruction_4(insn, 16, 3);
  uint64_t op2 = fieldFromInstruction_4(insn, 5, 3);
  uint64_t crm_high = fieldFromInstruction_4(insn, 9, 3);
  uint64_t imm = fieldFromInstruction_4(insn, 8, 1);
  uint64_t pstate_field = (crm_high << 6) | (op1 << 3) | op2;

  if (isInvalidPState(op1, op2))
    return Fail;

  MCOperand_CreateImm0(Inst, (pstate_field));
  MCOperand_CreateImm0(Inst, (imm));

  const AArch64PState_PStateImm0_1 *PState =
    AArch64PState_lookupPStateImm0_1ByEncoding(pstate_field);
  if (PState &&
      AArch64_testFeatureList(Inst->csh->mode, PState->FeaturesRequired))
    return Success;
  return Fail;
}

static DecodeStatus DecodeTestAndBranch(MCInst *Inst, uint32_t insn,
          uint64_t Addr, const void *Decoder)
{
  uint64_t Rt = fieldFromInstruction_4(insn, 0, 5);
  uint64_t bit = fieldFromInstruction_4(insn, 31, 1) << 5;
  bit |= fieldFromInstruction_4(insn, 19, 5);
  int64_t dst = fieldFromInstruction_4(insn, 5, 14);

  // Sign-extend 14-bit immediate.
  if (dst & (1 << (14 - 1)))
    dst |= ~((1LL << 14) - 1);

  if (fieldFromInstruction_4(insn, 31, 1) == 0)
    DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
  else
    DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
  MCOperand_CreateImm0(Inst, (bit));
  // No symbols supported in Capstone
  // if (!Decoder->tryAddingSymbolicOperand(Inst, dst * 4, Addr, true, 0, 0, 4))
  MCOperand_CreateImm0(Inst, (dst));

  return Success;
}

static DecodeStatus DecodeGPRSeqPairsClassRegisterClass(MCInst *Inst,
              unsigned RegClassID,
              unsigned RegNo,
              uint64_t Addr,
              const void *Decoder)
{
  // Register number must be even (see CASP instruction)
  if (RegNo & 0x1)
    return Fail;

  unsigned Reg =
    AArch64MCRegisterClasses[RegClassID].RegsBegin[RegNo / 2];
  MCOperand_CreateReg0(Inst, (Reg));
  return Success;
}

static DecodeStatus DecodeWSeqPairsClassRegisterClass(MCInst *Inst,
                  unsigned RegNo,
                  uint64_t Addr,
                  const void *Decoder)
{
  return DecodeGPRSeqPairsClassRegisterClass(
    Inst, AArch64_WSeqPairsClassRegClassID, RegNo, Addr, Decoder);
}

static DecodeStatus DecodeXSeqPairsClassRegisterClass(MCInst *Inst,
                  unsigned RegNo,
                  uint64_t Addr,
                  const void *Decoder)
{
  return DecodeGPRSeqPairsClassRegisterClass(
    Inst, AArch64_XSeqPairsClassRegClassID, RegNo, Addr, Decoder);
}

static DecodeStatus DecodeSyspXzrInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr, const void *Decoder)
{
  unsigned op1 = fieldFromInstruction_4(insn, 16, 3);
  unsigned CRn = fieldFromInstruction_4(insn, 12, 4);
  unsigned CRm = fieldFromInstruction_4(insn, 8, 4);
  unsigned op2 = fieldFromInstruction_4(insn, 5, 3);
  unsigned Rt = fieldFromInstruction_4(insn, 0, 5);
  if (Rt != 0x1f)
    return Fail;

  MCOperand_CreateImm0(Inst, (op1));
  MCOperand_CreateImm0(Inst, (CRn));
  MCOperand_CreateImm0(Inst, (CRm));
  MCOperand_CreateImm0(Inst, (op2));
  DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);

  return Success;
}

static DecodeStatus DecodeSVELogicalImmInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr,
               const void *Decoder)
{
  unsigned Zdn = fieldFromInstruction_4(insn, 0, 5);
  unsigned imm = fieldFromInstruction_4(insn, 5, 13);
  if (!AArch64_AM_isValidDecodeLogicalImmediate(imm, 64))
    return Fail;

  // The same (tied) operand is added twice to the instruction.
  DecodeZPRRegisterClass(Inst, Zdn, Addr, Decoder);
  if (MCInst_getOpcode(Inst) != AArch64_DUPM_ZI)
    DecodeZPRRegisterClass(Inst, Zdn, Addr, Decoder);
  MCOperand_CreateImm0(Inst, (imm));
  return Success;
}

#define DEFINE_DecodeSImm(Bits) \
  static DecodeStatus CONCAT(DecodeSImm, Bits)(MCInst * Inst, \
                 uint64_t Imm, \
                 uint64_t Address, \
                 const void *Decoder) \
  { \
    if (Imm & ~((1LL << Bits) - 1)) \
      return Fail; \
\
    if (Imm & (1 << (Bits - 1))) \
      Imm |= ~((1LL << Bits) - 1); \
\
    MCOperand_CreateImm0(Inst, (Imm)); \
    return Success; \
  }
DEFINE_DecodeSImm(4);
DEFINE_DecodeSImm(5);
DEFINE_DecodeSImm(6);
DEFINE_DecodeSImm(8);
DEFINE_DecodeSImm(9);
DEFINE_DecodeSImm(10);

// Decode 8-bit signed/unsigned immediate for a given element width.
#define DEFINE_DecodeImm8OptLsl(ElementWidth) \
  static DecodeStatus CONCAT(DecodeImm8OptLsl, ElementWidth)( \
    MCInst * Inst, unsigned Imm, uint64_t Addr, \
    const void *Decoder) \
  { \
    unsigned Val = (uint8_t)Imm; \
    unsigned Shift = (Imm & 0x100) ? 8 : 0; \
    if (ElementWidth == 8 && Shift) \
      return Fail; \
    MCOperand_CreateImm0(Inst, (Val)); \
    MCOperand_CreateImm0(Inst, (Shift)); \
    return Success; \
  }
DEFINE_DecodeImm8OptLsl(8);
DEFINE_DecodeImm8OptLsl(16);
DEFINE_DecodeImm8OptLsl(32);
DEFINE_DecodeImm8OptLsl(64);

// Decode uimm4 ranged from 1-16.
static DecodeStatus DecodeSVEIncDecImm(MCInst *Inst, unsigned Imm,
               uint64_t Addr, const void *Decoder)
{
  MCOperand_CreateImm0(Inst, (Imm + 1));
  return Success;
}

static DecodeStatus DecodeSVCROp(MCInst *Inst, unsigned Imm, uint64_t Address,
         const void *Decoder)
{
  if (AArch64SVCR_lookupSVCRByEncoding(Imm)) {
    MCOperand_CreateImm0(Inst, (Imm));
    return Success;
  }
  return Fail;
}

static DecodeStatus DecodeCPYMemOpInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rs = fieldFromInstruction_4(insn, 16, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);

  // None of the registers may alias: if they do, then the instruction is not
  // merely unpredictable but actually entirely unallocated.
  if (Rd == Rs || Rs == Rn || Rd == Rn)
    return MCDisassembler_Fail;

  // All three register operands are written back, so they all appear
  // twice in the operand list, once as outputs and once as inputs.
  if (!DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
      !DecodeGPR64commonRegisterClass(Inst, Rs, Addr, Decoder) ||
      !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
      !DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
      !DecodeGPR64commonRegisterClass(Inst, Rs, Addr, Decoder) ||
      !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder))
    return MCDisassembler_Fail;

  return MCDisassembler_Success;
}

static DecodeStatus DecodeSETMemOpInstruction(MCInst *Inst, uint32_t insn,
                uint64_t Addr,
                const void *Decoder)
{
  unsigned Rd = fieldFromInstruction_4(insn, 0, 5);
  unsigned Rm = fieldFromInstruction_4(insn, 16, 5);
  unsigned Rn = fieldFromInstruction_4(insn, 5, 5);

  // None of the registers may alias: if they do, then the instruction is not
  // merely unpredictable but actually entirely unallocated.
  if (Rd == Rm || Rm == Rn || Rd == Rn)
    return MCDisassembler_Fail;

  // Rd and Rn (not Rm) register operands are written back, so they appear
  // twice in the operand list, once as outputs and once as inputs.
  if (!DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
      !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
      !DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
      !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
      !DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder))
    return MCDisassembler_Fail;

  return MCDisassembler_Success;
}

static DecodeStatus DecodePRFMRegInstruction(MCInst *Inst, uint32_t insn,
               uint64_t Addr, const void *Decoder)
{
  // PRFM with Rt = '11xxx' should be decoded as RPRFM.
  // Fail to decode and defer to fallback decoder table to decode RPRFM.
  unsigned Mask = 0x18;
  uint64_t Rt = fieldFromInstruction_4(insn, 0, 5);
  if ((Rt & Mask) == Mask)
    return Fail;

  uint64_t Rn = fieldFromInstruction_4(insn, 5, 5);
  uint64_t Shift = fieldFromInstruction_4(insn, 12, 1);
  uint64_t Extend = fieldFromInstruction_4(insn, 15, 1);
  uint64_t Rm = fieldFromInstruction_4(insn, 16, 5);

  MCOperand_CreateImm0(Inst, (Rt));
  DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);

  switch (MCInst_getOpcode(Inst)) {
  default:
    return Fail;
  case AArch64_PRFMroW:
    DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  case AArch64_PRFMroX:
    DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
    break;
  }

  DecodeMemExtend(Inst, (Extend << 1) | Shift, Addr, Decoder);

  return Success;
}

Coverage Report

Created: 2026-06-15 06:41