X86/MCTargetDesc/X86BaseInfo.h

//===-- X86BaseInfo.h - Top level definitions for X86 -------- --*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file contains small standalone helper functions and enum definitions for
// the X86 target useful for the compiler back-end and the MC libraries.
// As such, it deliberately does not include references to LLVM core
// code gen types, passes, etc..
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_X86_MCTARGETDESC_X86BASEINFO_H
#define LLVM_LIB_TARGET_X86_MCTARGETDESC_X86BASEINFO_H

#include "X86MCTargetDesc.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"

namespace llvm {

namespace X86 {
  // Enums for memory operand decoding.  Each memory operand is represented with
  // a 5 operand sequence in the form:
  //   [BaseReg, ScaleAmt, IndexReg, Disp, Segment]
  // These enums help decode this.
  enum {
    AddrBaseReg = 0,
    AddrScaleAmt = 1,
    AddrIndexReg = 2,
    AddrDisp = 3,

    /// AddrSegmentReg - The operand # of the segment in the memory operand.
    AddrSegmentReg = 4,

    /// AddrNumOperands - Total number of operands in a memory reference.
    AddrNumOperands = 5
  };

  /// AVX512 static rounding constants.  These need to match the values in
  /// avx512fintrin.h.
  enum STATIC_ROUNDING {
    TO_NEAREST_INT = 0,
    TO_NEG_INF = 1,
    TO_POS_INF = 2,
    TO_ZERO = 3,
    CUR_DIRECTION = 4,
    NO_EXC = 8
  };

  /// The constants to describe instr prefixes if there are
  enum IPREFIXES {
    IP_NO_PREFIX = 0,
    IP_HAS_OP_SIZE =   1U << 0,
    IP_HAS_AD_SIZE =   1U << 1,
    IP_HAS_REPEAT_NE = 1U << 2,
    IP_HAS_REPEAT =    1U << 3,
    IP_HAS_LOCK =      1U << 4,
    IP_HAS_NOTRACK =   1U << 5,
    IP_USE_VEX =       1U << 6,
    IP_USE_VEX2 =      1U << 7,
    IP_USE_VEX3 =      1U << 8,
    IP_USE_EVEX =      1U << 9,
    IP_USE_DISP8 =     1U << 10,
    IP_USE_DISP32 =    1U << 11,
  };

  enum OperandType : unsigned {
    /// AVX512 embedded rounding control. This should only have values 0-3.
    OPERAND_ROUNDING_CONTROL = MCOI::OPERAND_FIRST_TARGET,
    OPERAND_COND_CODE,
  };

  // X86 specific condition code. These correspond to X86_*_COND in
  // X86InstrInfo.td. They must be kept in synch.
  enum CondCode {
    COND_O = 0,
    COND_NO = 1,
    COND_B = 2,
    COND_AE = 3,
    COND_E = 4,
    COND_NE = 5,
    COND_BE = 6,
    COND_A = 7,
    COND_S = 8,
    COND_NS = 9,
    COND_P = 10,
    COND_NP = 11,
    COND_L = 12,
    COND_GE = 13,
    COND_LE = 14,
    COND_G = 15,
    LAST_VALID_COND = COND_G,

    // Artificial condition codes. These are used by analyzeBranch
    // to indicate a block terminated with two conditional branches that together
    // form a compound condition. They occur in code using FCMP_OEQ or FCMP_UNE,
    // which can't be represented on x86 with a single condition. These
    // are never used in MachineInstrs and are inverses of one another.
    COND_NE_OR_P,
    COND_E_AND_NP,

    COND_INVALID
  };

  // The classification for the first instruction in macro fusion.
  enum class FirstMacroFusionInstKind {
    // TEST
    Test,
    // CMP
    Cmp,
    // AND
    And,
    // FIXME: Zen 3 support branch fusion for OR/XOR.
    // ADD, SUB
    AddSub,
    // INC, DEC
    IncDec,
    // Not valid as a first macro fusion instruction
    Invalid
  };

  enum class SecondMacroFusionInstKind {
    // JA, JB and variants.
    AB,
    // JE, JL, JG and variants.
    ELG,
    // JS, JP, JO and variants
    SPO,
    // Not a fusible jump.
    Invalid,
  };

  /// \returns the type of the first instruction in macro-fusion.
  inline FirstMacroFusionInstKind
  classifyFirstOpcodeInMacroFusion(unsigned Opcode) {
    switch (Opcode) {
    default:
      return FirstMacroFusionInstKind::Invalid;
    // TEST
    case X86::TEST16i16:
    case X86::TEST16mr:
    case X86::TEST16ri:
    case X86::TEST16rr:
    case X86::TEST32i32:
    case X86::TEST32mr:
    case X86::TEST32ri:
    case X86::TEST32rr:
    case X86::TEST64i32:
    case X86::TEST64mr:
    case X86::TEST64ri32:
    case X86::TEST64rr:
    case X86::TEST8i8:
    case X86::TEST8mr:
    case X86::TEST8ri:
    case X86::TEST8rr:
      return FirstMacroFusionInstKind::Test;
    case X86::AND16i16:
    case X86::AND16ri:
    case X86::AND16ri8:
    case X86::AND16rm:
    case X86::AND16rr:
    case X86::AND16rr_REV:
    case X86::AND32i32:
    case X86::AND32ri:
    case X86::AND32ri8:
    case X86::AND32rm:
    case X86::AND32rr:
    case X86::AND32rr_REV:
    case X86::AND64i32:
    case X86::AND64ri32:
    case X86::AND64ri8:
    case X86::AND64rm:
    case X86::AND64rr:
    case X86::AND64rr_REV:
    case X86::AND8i8:
    case X86::AND8ri:
    case X86::AND8ri8:
    case X86::AND8rm:
    case X86::AND8rr:
    case X86::AND8rr_REV:
      return FirstMacroFusionInstKind::And;
    // FIXME: Zen 3 support branch fusion for OR/XOR.
    // CMP
    case X86::CMP16i16:
    case X86::CMP16mr:
    case X86::CMP16ri:
    case X86::CMP16ri8:
    case X86::CMP16rm:
    case X86::CMP16rr:
    case X86::CMP16rr_REV:
    case X86::CMP32i32:
    case X86::CMP32mr:
    case X86::CMP32ri:
    case X86::CMP32ri8:
    case X86::CMP32rm:
    case X86::CMP32rr:
    case X86::CMP32rr_REV:
    case X86::CMP64i32:
    case X86::CMP64mr:
    case X86::CMP64ri32:
    case X86::CMP64ri8:
    case X86::CMP64rm:
    case X86::CMP64rr:
    case X86::CMP64rr_REV:
    case X86::CMP8i8:
    case X86::CMP8mr:
    case X86::CMP8ri:
    case X86::CMP8ri8:
    case X86::CMP8rm:
    case X86::CMP8rr:
    case X86::CMP8rr_REV:
      return FirstMacroFusionInstKind::Cmp;
    // ADD
    case X86::ADD16i16:
    case X86::ADD16ri:
    case X86::ADD16ri8:
    case X86::ADD16rm:
    case X86::ADD16rr:
    case X86::ADD16rr_REV:
    case X86::ADD32i32:
    case X86::ADD32ri:
    case X86::ADD32ri8:
    case X86::ADD32rm:
    case X86::ADD32rr:
    case X86::ADD32rr_REV:
    case X86::ADD64i32:
    case X86::ADD64ri32:
    case X86::ADD64ri8:
    case X86::ADD64rm:
    case X86::ADD64rr:
    case X86::ADD64rr_REV:
    case X86::ADD8i8:
    case X86::ADD8ri:
    case X86::ADD8ri8:
    case X86::ADD8rm:
    case X86::ADD8rr:
    case X86::ADD8rr_REV:
    // SUB
    case X86::SUB16i16:
    case X86::SUB16ri:
    case X86::SUB16ri8:
    case X86::SUB16rm:
    case X86::SUB16rr:
    case X86::SUB16rr_REV:
    case X86::SUB32i32:
    case X86::SUB32ri:
    case X86::SUB32ri8:
    case X86::SUB32rm:
    case X86::SUB32rr:
    case X86::SUB32rr_REV:
    case X86::SUB64i32:
    case X86::SUB64ri32:
    case X86::SUB64ri8:
    case X86::SUB64rm:
    case X86::SUB64rr:
    case X86::SUB64rr_REV:
    case X86::SUB8i8:
    case X86::SUB8ri:
    case X86::SUB8ri8:
    case X86::SUB8rm:
    case X86::SUB8rr:
    case X86::SUB8rr_REV:
      return FirstMacroFusionInstKind::AddSub;
    // INC
    case X86::INC16r:
    case X86::INC16r_alt:
    case X86::INC32r:
    case X86::INC32r_alt:
    case X86::INC64r:
    case X86::INC8r:
    // DEC
    case X86::DEC16r:
    case X86::DEC16r_alt:
    case X86::DEC32r:
    case X86::DEC32r_alt:
    case X86::DEC64r:
    case X86::DEC8r:
      return FirstMacroFusionInstKind::IncDec;
    }
  }

  /// \returns the type of the second instruction in macro-fusion.
  inline SecondMacroFusionInstKind
  classifySecondCondCodeInMacroFusion(X86::CondCode CC) {
    if (CC == X86::COND_INVALID)
      return SecondMacroFusionInstKind::Invalid;

    switch (CC) {
    default:
      return SecondMacroFusionInstKind::Invalid;
    // JE,JZ
    case X86::COND_E:
    // JNE,JNZ
    case X86::COND_NE:
    // JL,JNGE
    case X86::COND_L:
    // JLE,JNG
    case X86::COND_LE:
    // JG,JNLE
    case X86::COND_G:
    // JGE,JNL
    case X86::COND_GE:
      return SecondMacroFusionInstKind::ELG;
    // JB,JC
    case X86::COND_B:
    // JNA,JBE
    case X86::COND_BE:
    // JA,JNBE
    case X86::COND_A:
    // JAE,JNC,JNB
    case X86::COND_AE:
      return SecondMacroFusionInstKind::AB;
    // JS
    case X86::COND_S:
    // JNS
    case X86::COND_NS:
    // JP,JPE
    case X86::COND_P:
    // JNP,JPO
    case X86::COND_NP:
    // JO
    case X86::COND_O:
    // JNO
    case X86::COND_NO:
      return SecondMacroFusionInstKind::SPO;
    }
  }

  /// \param FirstKind kind of the first instruction in macro fusion.
  /// \param SecondKind kind of the second instruction in macro fusion.
  ///
  /// \returns true if the two instruction can be macro fused.
  inline bool isMacroFused(FirstMacroFusionInstKind FirstKind,
                           SecondMacroFusionInstKind SecondKind) {
    switch (FirstKind) {
    case X86::FirstMacroFusionInstKind::Test:
    case X86::FirstMacroFusionInstKind::And:
      return true;
    case X86::FirstMacroFusionInstKind::Cmp:
    case X86::FirstMacroFusionInstKind::AddSub:
      return SecondKind == X86::SecondMacroFusionInstKind::AB ||
             SecondKind == X86::SecondMacroFusionInstKind::ELG;
    case X86::FirstMacroFusionInstKind::IncDec:
      return SecondKind == X86::SecondMacroFusionInstKind::ELG;
    case X86::FirstMacroFusionInstKind::Invalid:
      return false;
    }
    llvm_unreachable("unknown fusion type");
  }

  /// Defines the possible values of the branch boundary alignment mask.
  enum AlignBranchBoundaryKind : uint8_t {
    AlignBranchNone = 0,
    AlignBranchFused = 1U << 0,
    AlignBranchJcc = 1U << 1,
    AlignBranchJmp = 1U << 2,
    AlignBranchCall = 1U << 3,
    AlignBranchRet = 1U << 4,
    AlignBranchIndirect = 1U << 5
  };

  /// Defines the encoding values for segment override prefix.
  enum EncodingOfSegmentOverridePrefix : uint8_t {
    CS_Encoding = 0x2E,
    DS_Encoding = 0x3E,
    ES_Encoding = 0x26,
    FS_Encoding = 0x64,
    GS_Encoding = 0x65,
    SS_Encoding = 0x36
  };

  /// Given a segment register, return the encoding of the segment override
  /// prefix for it.
  inline EncodingOfSegmentOverridePrefix
  getSegmentOverridePrefixForReg(unsigned Reg) {
    switch (Reg) {
    default:
      llvm_unreachable("Unknown segment register!");
    case X86::CS:
      return CS_Encoding;
    case X86::DS:
      return DS_Encoding;
    case X86::ES:
      return ES_Encoding;
    case X86::FS:
      return FS_Encoding;
    case X86::GS:
      return GS_Encoding;
    case X86::SS:
      return SS_Encoding;
    }
  }

} // end namespace X86;

/// X86II - This namespace holds all of the target specific flags that
/// instruction info tracks.
///
namespace X86II {
  /// Target Operand Flag enum.
  enum TOF {
    //===------------------------------------------------------------------===//
    // X86 Specific MachineOperand flags.

    MO_NO_FLAG,

    /// MO_GOT_ABSOLUTE_ADDRESS - On a symbol operand, this represents a
    /// relocation of:
    ///    SYMBOL_LABEL + [. - PICBASELABEL]
    MO_GOT_ABSOLUTE_ADDRESS,

    /// MO_PIC_BASE_OFFSET - On a symbol operand this indicates that the
    /// immediate should get the value of the symbol minus the PIC base label:
    ///    SYMBOL_LABEL - PICBASELABEL
    MO_PIC_BASE_OFFSET,

    /// MO_GOT - On a symbol operand this indicates that the immediate is the
    /// offset to the GOT entry for the symbol name from the base of the GOT.
    ///
    /// See the X86-64 ELF ABI supplement for more details.
    ///    SYMBOL_LABEL @GOT
    MO_GOT,

    /// MO_GOTOFF - On a symbol operand this indicates that the immediate is
    /// the offset to the location of the symbol name from the base of the GOT.
    ///
    /// See the X86-64 ELF ABI supplement for more details.
    ///    SYMBOL_LABEL @GOTOFF
    MO_GOTOFF,

    /// MO_GOTPCREL - On a symbol operand this indicates that the immediate is
    /// offset to the GOT entry for the symbol name from the current code
    /// location.
    ///
    /// See the X86-64 ELF ABI supplement for more details.
    ///    SYMBOL_LABEL @GOTPCREL
    MO_GOTPCREL,

    /// MO_PLT - On a symbol operand this indicates that the immediate is
    /// offset to the PLT entry of symbol name from the current code location.
    ///
    /// See the X86-64 ELF ABI supplement for more details.
    ///    SYMBOL_LABEL @PLT
    MO_PLT,

    /// MO_TLSGD - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the TLS index structure that contains
    /// the module number and variable offset for the symbol. Used in the
    /// general dynamic TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @TLSGD
    MO_TLSGD,

    /// MO_TLSLD - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the TLS index for the module that
    /// contains the symbol. When this index is passed to a call to
    /// __tls_get_addr, the function will return the base address of the TLS
    /// block for the symbol. Used in the x86-64 local dynamic TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @TLSLD
    MO_TLSLD,

    /// MO_TLSLDM - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the TLS index for the module that
    /// contains the symbol. When this index is passed to a call to
    /// ___tls_get_addr, the function will return the base address of the TLS
    /// block for the symbol. Used in the IA32 local dynamic TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @TLSLDM
    MO_TLSLDM,

    /// MO_GOTTPOFF - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the thread-pointer offset for the
    /// symbol. Used in the x86-64 initial exec TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @GOTTPOFF
    MO_GOTTPOFF,

    /// MO_INDNTPOFF - On a symbol operand this indicates that the immediate is
    /// the absolute address of the GOT entry with the negative thread-pointer
    /// offset for the symbol. Used in the non-PIC IA32 initial exec TLS access
    /// model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @INDNTPOFF
    MO_INDNTPOFF,

    /// MO_TPOFF - On a symbol operand this indicates that the immediate is
    /// the thread-pointer offset for the symbol. Used in the x86-64 local
    /// exec TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @TPOFF
    MO_TPOFF,

    /// MO_DTPOFF - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the TLS offset of the symbol. Used
    /// in the local dynamic TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @DTPOFF
    MO_DTPOFF,

    /// MO_NTPOFF - On a symbol operand this indicates that the immediate is
    /// the negative thread-pointer offset for the symbol. Used in the IA32
    /// local exec TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @NTPOFF
    MO_NTPOFF,

    /// MO_GOTNTPOFF - On a symbol operand this indicates that the immediate is
    /// the offset of the GOT entry with the negative thread-pointer offset for
    /// the symbol. Used in the PIC IA32 initial exec TLS access model.
    ///
    /// See 'ELF Handling for Thread-Local Storage' for more details.
    ///    SYMBOL_LABEL @GOTNTPOFF
    MO_GOTNTPOFF,

    /// MO_DLLIMPORT - On a symbol operand "FOO", this indicates that the
    /// reference is actually to the "__imp_FOO" symbol.  This is used for
    /// dllimport linkage on windows.
    MO_DLLIMPORT,

    /// MO_DARWIN_NONLAZY - On a symbol operand "FOO", this indicates that the
    /// reference is actually to the "FOO$non_lazy_ptr" symbol, which is a
    /// non-PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
    MO_DARWIN_NONLAZY,

    /// MO_DARWIN_NONLAZY_PIC_BASE - On a symbol operand "FOO", this indicates
    /// that the reference is actually to "FOO$non_lazy_ptr - PICBASE", which is
    /// a PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
    MO_DARWIN_NONLAZY_PIC_BASE,

    /// MO_TLVP - On a symbol operand this indicates that the immediate is
    /// some TLS offset.
    ///
    /// This is the TLS offset for the Darwin TLS mechanism.
    MO_TLVP,

    /// MO_TLVP_PIC_BASE - On a symbol operand this indicates that the immediate
    /// is some TLS offset from the picbase.
    ///
    /// This is the 32-bit TLS offset for Darwin TLS in PIC mode.
    MO_TLVP_PIC_BASE,

    /// MO_SECREL - On a symbol operand this indicates that the immediate is
    /// the offset from beginning of section.
    ///
    /// This is the TLS offset for the COFF/Windows TLS mechanism.
    MO_SECREL,

    /// MO_ABS8 - On a symbol operand this indicates that the symbol is known
    /// to be an absolute symbol in range [0,128), so we can use the @ABS8
    /// symbol modifier.
    MO_ABS8,

    /// MO_COFFSTUB - On a symbol operand "FOO", this indicates that the
    /// reference is actually to the ".refptr.FOO" symbol.  This is used for
    /// stub symbols on windows.
    MO_COFFSTUB,
  };

  enum : uint64_t {
    //===------------------------------------------------------------------===//
    // Instruction encodings.  These are the standard/most common forms for X86
    // instructions.
    //

    // PseudoFrm - This represents an instruction that is a pseudo instruction
    // or one that has not been implemented yet.  It is illegal to code generate
    // it, but tolerated for intermediate implementation stages.
    Pseudo         = 0,

    /// Raw - This form is for instructions that don't have any operands, so
    /// they are just a fixed opcode value, like 'leave'.
    RawFrm         = 1,

    /// AddRegFrm - This form is used for instructions like 'push r32' that have
    /// their one register operand added to their opcode.
    AddRegFrm      = 2,

    /// RawFrmMemOffs - This form is for instructions that store an absolute
    /// memory offset as an immediate with a possible segment override.
    RawFrmMemOffs  = 3,

    /// RawFrmSrc - This form is for instructions that use the source index
    /// register SI/ESI/RSI with a possible segment override.
    RawFrmSrc      = 4,

    /// RawFrmDst - This form is for instructions that use the destination index
    /// register DI/EDI/RDI.
    RawFrmDst      = 5,

    /// RawFrmDstSrc - This form is for instructions that use the source index
    /// register SI/ESI/RSI with a possible segment override, and also the
    /// destination index register DI/EDI/RDI.
    RawFrmDstSrc   = 6,

    /// RawFrmImm8 - This is used for the ENTER instruction, which has two
    /// immediates, the first of which is a 16-bit immediate (specified by
    /// the imm encoding) and the second is a 8-bit fixed value.
    RawFrmImm8 = 7,

    /// RawFrmImm16 - This is used for CALL FAR instructions, which have two
    /// immediates, the first of which is a 16 or 32-bit immediate (specified by
    /// the imm encoding) and the second is a 16-bit fixed value.  In the AMD
    /// manual, this operand is described as pntr16:32 and pntr16:16
    RawFrmImm16 = 8,

    /// AddCCFrm - This form is used for Jcc that encode the condition code
    /// in the lower 4 bits of the opcode.
    AddCCFrm = 9,

    /// PrefixByte - This form is used for instructions that represent a prefix
    /// byte like data16 or rep.
    PrefixByte = 10,

    /// MRM[0-7][rm] - These forms are used to represent instructions that use
    /// a Mod/RM byte, and use the middle field to hold extended opcode
    /// information.  In the intel manual these are represented as /0, /1, ...
    ///

    // Instructions operate on a register Reg/Opcode operand not the r/m field.
    MRMr0 = 21,

    /// MRMSrcMem - But force to use the SIB field.
    MRMSrcMemFSIB  = 22,

    /// MRMDestMem - But force to use the SIB field.
    MRMDestMemFSIB = 23,

    /// MRMDestMem - This form is used for instructions that use the Mod/RM byte
    /// to specify a destination, which in this case is memory.
    ///
    MRMDestMem     = 24,

    /// MRMSrcMem - This form is used for instructions that use the Mod/RM byte
    /// to specify a source, which in this case is memory.
    ///
    MRMSrcMem      = 25,

    /// MRMSrcMem4VOp3 - This form is used for instructions that encode
    /// operand 3 with VEX.VVVV and load from memory.
    ///
    MRMSrcMem4VOp3 = 26,

    /// MRMSrcMemOp4 - This form is used for instructions that use the Mod/RM
    /// byte to specify the fourth source, which in this case is memory.
    ///
    MRMSrcMemOp4   = 27,

    /// MRMSrcMemCC - This form is used for instructions that use the Mod/RM
    /// byte to specify the operands and also encodes a condition code.
    ///
    MRMSrcMemCC    = 28,

    /// MRMXm - This form is used for instructions that use the Mod/RM byte
    /// to specify a memory source, but doesn't use the middle field. And has
    /// a condition code.
    ///
    MRMXmCC = 30,

    /// MRMXm - This form is used for instructions that use the Mod/RM byte
    /// to specify a memory source, but doesn't use the middle field.
    ///
    MRMXm = 31,

    // Next, instructions that operate on a memory r/m operand...
    MRM0m = 32,  MRM1m = 33,  MRM2m = 34,  MRM3m = 35, // Format /0 /1 /2 /3
    MRM4m = 36,  MRM5m = 37,  MRM6m = 38,  MRM7m = 39, // Format /4 /5 /6 /7

    /// MRMDestReg - This form is used for instructions that use the Mod/RM byte
    /// to specify a destination, which in this case is a register.
    ///
    MRMDestReg     = 40,

    /// MRMSrcReg - This form is used for instructions that use the Mod/RM byte
    /// to specify a source, which in this case is a register.
    ///
    MRMSrcReg      = 41,

    /// MRMSrcReg4VOp3 - This form is used for instructions that encode
    /// operand 3 with VEX.VVVV and do not load from memory.
    ///
    MRMSrcReg4VOp3 = 42,

    /// MRMSrcRegOp4 - This form is used for instructions that use the Mod/RM
    /// byte to specify the fourth source, which in this case is a register.
    ///
    MRMSrcRegOp4   = 43,

    /// MRMSrcRegCC - This form is used for instructions that use the Mod/RM
    /// byte to specify the operands and also encodes a condition code
    ///
    MRMSrcRegCC    = 44,

    /// MRMXCCr - This form is used for instructions that use the Mod/RM byte
    /// to specify a register source, but doesn't use the middle field. And has
    /// a condition code.
    ///
    MRMXrCC = 46,

    /// MRMXr - This form is used for instructions that use the Mod/RM byte
    /// to specify a register source, but doesn't use the middle field.
    ///
    MRMXr = 47,

    // Instructions that operate on a register r/m operand...
    MRM0r = 48,  MRM1r = 49,  MRM2r = 50,  MRM3r = 51, // Format /0 /1 /2 /3
    MRM4r = 52,  MRM5r = 53,  MRM6r = 54,  MRM7r = 55, // Format /4 /5 /6 /7

    // Instructions that operate that have mod=11 and an opcode but ignore r/m.
    MRM0X = 56,  MRM1X = 57,  MRM2X = 58,  MRM3X = 59, // Format /0 /1 /2 /3
    MRM4X = 60,  MRM5X = 61,  MRM6X = 62,  MRM7X = 63, // Format /4 /5 /6 /7

    /// MRM_XX - A mod/rm byte of exactly 0xXX.
    MRM_C0 = 64,  MRM_C1 = 65,  MRM_C2 = 66,  MRM_C3 = 67,
    MRM_C4 = 68,  MRM_C5 = 69,  MRM_C6 = 70,  MRM_C7 = 71,
    MRM_C8 = 72,  MRM_C9 = 73,  MRM_CA = 74,  MRM_CB = 75,
    MRM_CC = 76,  MRM_CD = 77,  MRM_CE = 78,  MRM_CF = 79,
    MRM_D0 = 80,  MRM_D1 = 81,  MRM_D2 = 82,  MRM_D3 = 83,
    MRM_D4 = 84,  MRM_D5 = 85,  MRM_D6 = 86,  MRM_D7 = 87,
    MRM_D8 = 88,  MRM_D9 = 89,  MRM_DA = 90,  MRM_DB = 91,
    MRM_DC = 92,  MRM_DD = 93,  MRM_DE = 94,  MRM_DF = 95,
    MRM_E0 = 96,  MRM_E1 = 97,  MRM_E2 = 98,  MRM_E3 = 99,
    MRM_E4 = 100, MRM_E5 = 101, MRM_E6 = 102, MRM_E7 = 103,
    MRM_E8 = 104, MRM_E9 = 105, MRM_EA = 106, MRM_EB = 107,
    MRM_EC = 108, MRM_ED = 109, MRM_EE = 110, MRM_EF = 111,
    MRM_F0 = 112, MRM_F1 = 113, MRM_F2 = 114, MRM_F3 = 115,
    MRM_F4 = 116, MRM_F5 = 117, MRM_F6 = 118, MRM_F7 = 119,
    MRM_F8 = 120, MRM_F9 = 121, MRM_FA = 122, MRM_FB = 123,
    MRM_FC = 124, MRM_FD = 125, MRM_FE = 126, MRM_FF = 127,

    FormMask       = 127,

    //===------------------------------------------------------------------===//
    // Actual flags...

    // OpSize - OpSizeFixed implies instruction never needs a 0x66 prefix.
    // OpSize16 means this is a 16-bit instruction and needs 0x66 prefix in
    // 32-bit mode. OpSize32 means this is a 32-bit instruction needs a 0x66
    // prefix in 16-bit mode.
    OpSizeShift = 7,
    OpSizeMask = 0x3 << OpSizeShift,

    OpSizeFixed  = 0 << OpSizeShift,
    OpSize16     = 1 << OpSizeShift,
    OpSize32     = 2 << OpSizeShift,

    // AsSize - AdSizeX implies this instruction determines its need of 0x67
    // prefix from a normal ModRM memory operand. The other types indicate that
    // an operand is encoded with a specific width and a prefix is needed if
    // it differs from the current mode.
    AdSizeShift = OpSizeShift + 2,
    AdSizeMask  = 0x3 << AdSizeShift,

    AdSizeX  = 0 << AdSizeShift,
    AdSize16 = 1 << AdSizeShift,
    AdSize32 = 2 << AdSizeShift,
    AdSize64 = 3 << AdSizeShift,

    //===------------------------------------------------------------------===//
    // OpPrefix - There are several prefix bytes that are used as opcode
    // extensions. These are 0x66, 0xF3, and 0xF2. If this field is 0 there is
    // no prefix.
    //
    OpPrefixShift = AdSizeShift + 2,
    OpPrefixMask  = 0x3 << OpPrefixShift,

    // PD - Prefix code for packed double precision vector floating point
    // operations performed in the SSE registers.
    PD = 1 << OpPrefixShift,

    // XS, XD - These prefix codes are for single and double precision scalar
    // floating point operations performed in the SSE registers.
    XS = 2 << OpPrefixShift,  XD = 3 << OpPrefixShift,

    //===------------------------------------------------------------------===//
    // OpMap - This field determines which opcode map this instruction
    // belongs to. i.e. one-byte, two-byte, 0x0f 0x38, 0x0f 0x3a, etc.
    //
    OpMapShift = OpPrefixShift + 2,
    OpMapMask  = 0x7 << OpMapShift,

    // OB - OneByte - Set if this instruction has a one byte opcode.
    OB = 0 << OpMapShift,

    // TB - TwoByte - Set if this instruction has a two byte opcode, which
    // starts with a 0x0F byte before the real opcode.
    TB = 1 << OpMapShift,

    // T8, TA - Prefix after the 0x0F prefix.
    T8 = 2 << OpMapShift,  TA = 3 << OpMapShift,

    // XOP8 - Prefix to include use of imm byte.
    XOP8 = 4 << OpMapShift,

    // XOP9 - Prefix to exclude use of imm byte.
    XOP9 = 5 << OpMapShift,

    // XOPA - Prefix to encode 0xA in VEX.MMMM of XOP instructions.
    XOPA = 6 << OpMapShift,

    /// ThreeDNow - This indicates that the instruction uses the
    /// wacky 0x0F 0x0F prefix for 3DNow! instructions.  The manual documents
    /// this as having a 0x0F prefix with a 0x0F opcode, and each instruction
    /// storing a classifier in the imm8 field.  To simplify our implementation,
    /// we handle this by storeing the classifier in the opcode field and using
    /// this flag to indicate that the encoder should do the wacky 3DNow! thing.
    ThreeDNow = 7 << OpMapShift,

    //===------------------------------------------------------------------===//
    // REX_W - REX prefixes are instruction prefixes used in 64-bit mode.
    // They are used to specify GPRs and SSE registers, 64-bit operand size,
    // etc. We only cares about REX.W and REX.R bits and only the former is
    // statically determined.
    //
    REXShift    = OpMapShift + 3,
    REX_W       = 1 << REXShift,

    //===------------------------------------------------------------------===//
    // This three-bit field describes the size of an immediate operand.  Zero is
    // unused so that we can tell if we forgot to set a value.
    ImmShift = REXShift + 1,
    ImmMask    = 15 << ImmShift,
    Imm8       = 1 << ImmShift,
    Imm8PCRel  = 2 << ImmShift,
    Imm8Reg    = 3 << ImmShift,
    Imm16      = 4 << ImmShift,
    Imm16PCRel = 5 << ImmShift,
    Imm32      = 6 << ImmShift,
    Imm32PCRel = 7 << ImmShift,
    Imm32S     = 8 << ImmShift,
    Imm64      = 9 << ImmShift,

    //===------------------------------------------------------------------===//
    // FP Instruction Classification...  Zero is non-fp instruction.

    // FPTypeMask - Mask for all of the FP types...
    FPTypeShift = ImmShift + 4,
    FPTypeMask  = 7 << FPTypeShift,

    // NotFP - The default, set for instructions that do not use FP registers.
    NotFP      = 0 << FPTypeShift,

    // ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0
    ZeroArgFP  = 1 << FPTypeShift,

    // OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst
    OneArgFP   = 2 << FPTypeShift,

    // OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a
    // result back to ST(0).  For example, fcos, fsqrt, etc.
    //
    OneArgFPRW = 3 << FPTypeShift,

    // TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an
    // explicit argument, storing the result to either ST(0) or the implicit
    // argument.  For example: fadd, fsub, fmul, etc...
    TwoArgFP   = 4 << FPTypeShift,

    // CompareFP - 2 arg FP instructions which implicitly read ST(0) and an
    // explicit argument, but have no destination.  Example: fucom, fucomi, ...
    CompareFP  = 5 << FPTypeShift,

    // CondMovFP - "2 operand" floating point conditional move instructions.
    CondMovFP  = 6 << FPTypeShift,

    // SpecialFP - Special instruction forms.  Dispatch by opcode explicitly.
    SpecialFP  = 7 << FPTypeShift,

    // Lock prefix
    LOCKShift = FPTypeShift + 3,
    LOCK = 1 << LOCKShift,

    // REP prefix
    REPShift = LOCKShift + 1,
    REP = 1 << REPShift,

    // Execution domain for SSE instructions.
    // 0 means normal, non-SSE instruction.
    SSEDomainShift = REPShift + 1,

    // Encoding
    EncodingShift = SSEDomainShift + 2,
    EncodingMask = 0x3 << EncodingShift,

    // VEX - encoding using 0xC4/0xC5
    VEX = 1 << EncodingShift,

    /// XOP - Opcode prefix used by XOP instructions.
    XOP = 2 << EncodingShift,

    // VEX_EVEX - Specifies that this instruction use EVEX form which provides
    // syntax support up to 32 512-bit register operands and up to 7 16-bit
    // mask operands as well as source operand data swizzling/memory operand
    // conversion, eviction hint, and rounding mode.
    EVEX = 3 << EncodingShift,

    // Opcode
    OpcodeShift   = EncodingShift + 2,

    /// VEX_W - Has a opcode specific functionality, but is used in the same
    /// way as REX_W is for regular SSE instructions.
    VEX_WShift  = OpcodeShift + 8,
    VEX_W       = 1ULL << VEX_WShift,

    /// VEX_4V - Used to specify an additional AVX/SSE register. Several 2
    /// address instructions in SSE are represented as 3 address ones in AVX
    /// and the additional register is encoded in VEX_VVVV prefix.
    VEX_4VShift = VEX_WShift + 1,
    VEX_4V      = 1ULL << VEX_4VShift,

    /// VEX_L - Stands for a bit in the VEX opcode prefix meaning the current
    /// instruction uses 256-bit wide registers. This is usually auto detected
    /// if a VR256 register is used, but some AVX instructions also have this
    /// field marked when using a f256 memory references.
    VEX_LShift = VEX_4VShift + 1,
    VEX_L       = 1ULL << VEX_LShift,

    // EVEX_K - Set if this instruction requires masking
    EVEX_KShift = VEX_LShift + 1,
    EVEX_K      = 1ULL << EVEX_KShift,

    // EVEX_Z - Set if this instruction has EVEX.Z field set.
    EVEX_ZShift = EVEX_KShift + 1,
    EVEX_Z      = 1ULL << EVEX_ZShift,

    // EVEX_L2 - Set if this instruction has EVEX.L' field set.
    EVEX_L2Shift = EVEX_ZShift + 1,
    EVEX_L2     = 1ULL << EVEX_L2Shift,

    // EVEX_B - Set if this instruction has EVEX.B field set.
    EVEX_BShift = EVEX_L2Shift + 1,
    EVEX_B      = 1ULL << EVEX_BShift,

    // The scaling factor for the AVX512's 8-bit compressed displacement.
    CD8_Scale_Shift = EVEX_BShift + 1,
    CD8_Scale_Mask = 127ULL << CD8_Scale_Shift,

    /// Explicitly specified rounding control
    EVEX_RCShift = CD8_Scale_Shift + 7,
    EVEX_RC = 1ULL << EVEX_RCShift,

    // NOTRACK prefix
    NoTrackShift = EVEX_RCShift + 1,
    NOTRACK = 1ULL << NoTrackShift,

    // Force VEX encoding
    ExplicitVEXShift = NoTrackShift + 1,
    ExplicitVEXPrefix = 1ULL << ExplicitVEXShift
  };

  /// \returns true if the instruction with given opcode is a prefix.
  inline bool isPrefix(uint64_t TSFlags) {
    return (TSFlags & X86II::FormMask) == PrefixByte;
  }

  /// \returns true if the instruction with given opcode is a pseudo.
  inline bool isPseudo(uint64_t TSFlags) {
    return (TSFlags & X86II::FormMask) == Pseudo;
  }

  /// \returns the "base" X86 opcode for the specified machine
  /// instruction.
  inline uint8_t getBaseOpcodeFor(uint64_t TSFlags) {
    return TSFlags >> X86II::OpcodeShift;
  }

  inline bool hasImm(uint64_t TSFlags) {
    return (TSFlags & X86II::ImmMask) != 0;
  }

  /// Decode the "size of immediate" field from the TSFlags field of the
  /// specified instruction.
  inline unsigned getSizeOfImm(uint64_t TSFlags) {
    switch (TSFlags & X86II::ImmMask) {
    default: llvm_unreachable("Unknown immediate size");
    case X86II::Imm8:
    case X86II::Imm8PCRel:
    case X86II::Imm8Reg:    return 1;
    case X86II::Imm16:
    case X86II::Imm16PCRel: return 2;
    case X86II::Imm32:
    case X86II::Imm32S:
    case X86II::Imm32PCRel: return 4;
    case X86II::Imm64:      return 8;
    }
  }

  /// \returns true if the immediate of the specified instruction's TSFlags
  /// indicates that it is pc relative.
  inline bool isImmPCRel(uint64_t TSFlags) {
    switch (TSFlags & X86II::ImmMask) {
    default: llvm_unreachable("Unknown immediate size");
    case X86II::Imm8PCRel:
    case X86II::Imm16PCRel:
    case X86II::Imm32PCRel:
      return true;
    case X86II::Imm8:
    case X86II::Imm8Reg:
    case X86II::Imm16:
    case X86II::Imm32:
    case X86II::Imm32S:
    case X86II::Imm64:
      return false;
    }
  }

  /// \returns true if the immediate of the specified instruction's
  /// TSFlags indicates that it is signed.
  inline bool isImmSigned(uint64_t TSFlags) {
    switch (TSFlags & X86II::ImmMask) {
    default: llvm_unreachable("Unknown immediate signedness");
    case X86II::Imm32S:
      return true;
    case X86II::Imm8:
    case X86II::Imm8PCRel:
    case X86II::Imm8Reg:
    case X86II::Imm16:
    case X86II::Imm16PCRel:
    case X86II::Imm32:
    case X86II::Imm32PCRel:
    case X86II::Imm64:
      return false;
    }
  }

  /// Compute whether all of the def operands are repeated in the uses and
  /// therefore should be skipped.
  /// This determines the start of the unique operand list. We need to determine
  /// if all of the defs have a corresponding tied operand in the uses.
  /// Unfortunately, the tied operand information is encoded in the uses not
  /// the defs so we have to use some heuristics to find which operands to
  /// query.
  inline unsigned getOperandBias(const MCInstrDesc& Desc) {
    unsigned NumDefs = Desc.getNumDefs();
    unsigned NumOps = Desc.getNumOperands();
    switch (NumDefs) {
    default: llvm_unreachable("Unexpected number of defs");
    case 0:
      return 0;
    case 1:
      // Common two addr case.
      if (NumOps > 1 && Desc.getOperandConstraint(1, MCOI::TIED_TO) == 0)
        return 1;
      // Check for AVX-512 scatter which has a TIED_TO in the second to last
      // operand.
      if (NumOps == 8 &&
          Desc.getOperandConstraint(6, MCOI::TIED_TO) == 0)
        return 1;
      return 0;
    case 2:
      // XCHG/XADD have two destinations and two sources.
      if (NumOps >= 4 && Desc.getOperandConstraint(2, MCOI::TIED_TO) == 0 &&
          Desc.getOperandConstraint(3, MCOI::TIED_TO) == 1)
        return 2;
      // Check for gather. AVX-512 has the second tied operand early. AVX2
      // has it as the last op.
      if (NumOps == 9 && Desc.getOperandConstraint(2, MCOI::TIED_TO) == 0 &&
          (Desc.getOperandConstraint(3, MCOI::TIED_TO) == 1 ||
           Desc.getOperandConstraint(8, MCOI::TIED_TO) == 1))
        return 2;
      return 0;
    }
  }

  /// The function returns the MCInst operand # for the first field of the
  /// memory operand.  If the instruction doesn't have a
  /// memory operand, this returns -1.
  ///
  /// Note that this ignores tied operands.  If there is a tied register which
  /// is duplicated in the MCInst (e.g. "EAX = addl EAX, [mem]") it is only
  /// counted as one operand.
  ///
  inline int getMemoryOperandNo(uint64_t TSFlags) {
    bool HasVEX_4V = TSFlags & X86II::VEX_4V;
    bool HasEVEX_K = TSFlags & X86II::EVEX_K;

    switch (TSFlags & X86II::FormMask) {
    default: llvm_unreachable("Unknown FormMask value in getMemoryOperandNo!");
    case X86II::Pseudo:
    case X86II::RawFrm:
    case X86II::AddRegFrm:
    case X86II::RawFrmImm8:
    case X86II::RawFrmImm16:
    case X86II::RawFrmMemOffs:
    case X86II::RawFrmSrc:
    case X86II::RawFrmDst:
    case X86II::RawFrmDstSrc:
    case X86II::AddCCFrm:
    case X86II::PrefixByte:
      return -1;
    case X86II::MRMDestMem:
    case X86II::MRMDestMemFSIB:
      return 0;
    case X86II::MRMSrcMem:
    case X86II::MRMSrcMemFSIB:
      // Start from 1, skip any registers encoded in VEX_VVVV or I8IMM, or a
      // mask register.
      return 1 + HasVEX_4V + HasEVEX_K;
    case X86II::MRMSrcMem4VOp3:
      // Skip registers encoded in reg.
      return 1 + HasEVEX_K;
    case X86II::MRMSrcMemOp4:
      // Skip registers encoded in reg, VEX_VVVV, and I8IMM.
      return 3;
    case X86II::MRMSrcMemCC:
      // Start from 1, skip any registers encoded in VEX_VVVV or I8IMM, or a
      // mask register.
      return 1;
    case X86II::MRMDestReg:
    case X86II::MRMSrcReg:
    case X86II::MRMSrcReg4VOp3:
    case X86II::MRMSrcRegOp4:
    case X86II::MRMSrcRegCC:
    case X86II::MRMXrCC:
    case X86II::MRMr0:
    case X86II::MRMXr:
    case X86II::MRM0r: case X86II::MRM1r:
    case X86II::MRM2r: case X86II::MRM3r:
    case X86II::MRM4r: case X86II::MRM5r:
    case X86II::MRM6r: case X86II::MRM7r:
      return -1;
    case X86II::MRM0X: case X86II::MRM1X:
    case X86II::MRM2X: case X86II::MRM3X:
    case X86II::MRM4X: case X86II::MRM5X:
    case X86II::MRM6X: case X86II::MRM7X:
      return -1;
    case X86II::MRMXmCC:
    case X86II::MRMXm:
    case X86II::MRM0m: case X86II::MRM1m:
    case X86II::MRM2m: case X86II::MRM3m:
    case X86II::MRM4m: case X86II::MRM5m:
    case X86II::MRM6m: case X86II::MRM7m:
      // Start from 0, skip registers encoded in VEX_VVVV or a mask register.
      return 0 + HasVEX_4V + HasEVEX_K;
    case X86II::MRM_C0: case X86II::MRM_C1: case X86II::MRM_C2:
    case X86II::MRM_C3: case X86II::MRM_C4: case X86II::MRM_C5:
    case X86II::MRM_C6: case X86II::MRM_C7: case X86II::MRM_C8:
    case X86II::MRM_C9: case X86II::MRM_CA: case X86II::MRM_CB:
    case X86II::MRM_CC: case X86II::MRM_CD: case X86II::MRM_CE:
    case X86II::MRM_CF: case X86II::MRM_D0: case X86II::MRM_D1:
    case X86II::MRM_D2: case X86II::MRM_D3: case X86II::MRM_D4:
    case X86II::MRM_D5: case X86II::MRM_D6: case X86II::MRM_D7:
    case X86II::MRM_D8: case X86II::MRM_D9: case X86II::MRM_DA:
    case X86II::MRM_DB: case X86II::MRM_DC: case X86II::MRM_DD:
    case X86II::MRM_DE: case X86II::MRM_DF: case X86II::MRM_E0:
    case X86II::MRM_E1: case X86II::MRM_E2: case X86II::MRM_E3:
    case X86II::MRM_E4: case X86II::MRM_E5: case X86II::MRM_E6:
    case X86II::MRM_E7: case X86II::MRM_E8: case X86II::MRM_E9:
    case X86II::MRM_EA: case X86II::MRM_EB: case X86II::MRM_EC:
    case X86II::MRM_ED: case X86II::MRM_EE: case X86II::MRM_EF:
    case X86II::MRM_F0: case X86II::MRM_F1: case X86II::MRM_F2:
    case X86II::MRM_F3: case X86II::MRM_F4: case X86II::MRM_F5:
    case X86II::MRM_F6: case X86II::MRM_F7: case X86II::MRM_F8:
    case X86II::MRM_F9: case X86II::MRM_FA: case X86II::MRM_FB:
    case X86II::MRM_FC: case X86II::MRM_FD: case X86II::MRM_FE:
    case X86II::MRM_FF:
      return -1;
    }
  }

  /// \returns true if the MachineOperand is a x86-64 extended (r8 or
  /// higher) register,  e.g. r8, xmm8, xmm13, etc.
  inline bool isX86_64ExtendedReg(unsigned RegNo) {
    if ((RegNo >= X86::XMM8 && RegNo <= X86::XMM31) ||
        (RegNo >= X86::YMM8 && RegNo <= X86::YMM31) ||
        (RegNo >= X86::ZMM8 && RegNo <= X86::ZMM31))
      return true;

    switch (RegNo) {
    default: break;
    case X86::R8:    case X86::R9:    case X86::R10:   case X86::R11:
    case X86::R12:   case X86::R13:   case X86::R14:   case X86::R15:
    case X86::R8D:   case X86::R9D:   case X86::R10D:  case X86::R11D:
    case X86::R12D:  case X86::R13D:  case X86::R14D:  case X86::R15D:
    case X86::R8W:   case X86::R9W:   case X86::R10W:  case X86::R11W:
    case X86::R12W:  case X86::R13W:  case X86::R14W:  case X86::R15W:
    case X86::R8B:   case X86::R9B:   case X86::R10B:  case X86::R11B:
    case X86::R12B:  case X86::R13B:  case X86::R14B:  case X86::R15B:
    case X86::CR8:   case X86::CR9:   case X86::CR10:  case X86::CR11:
    case X86::CR12:  case X86::CR13:  case X86::CR14:  case X86::CR15:
    case X86::DR8:   case X86::DR9:   case X86::DR10:  case X86::DR11:
    case X86::DR12:  case X86::DR13:  case X86::DR14:  case X86::DR15:
      return true;
    }
    return false;
  }

  /// \returns true if the MemoryOperand is a 32 extended (zmm16 or higher)
  /// registers, e.g. zmm21, etc.
  static inline bool is32ExtendedReg(unsigned RegNo) {
    return ((RegNo >= X86::XMM16 && RegNo <= X86::XMM31) ||
            (RegNo >= X86::YMM16 && RegNo <= X86::YMM31) ||
            (RegNo >= X86::ZMM16 && RegNo <= X86::ZMM31));
  }


  inline bool isX86_64NonExtLowByteReg(unsigned reg) {
    return (reg == X86::SPL || reg == X86::BPL ||
            reg == X86::SIL || reg == X86::DIL);
  }

  /// \returns true if this is a masked instruction.
  inline bool isKMasked(uint64_t TSFlags) {
    return (TSFlags & X86II::EVEX_K) != 0;
  }

  /// \returns true if this is a merge masked instruction.
  inline bool isKMergeMasked(uint64_t TSFlags) {
    return isKMasked(TSFlags) && (TSFlags & X86II::EVEX_Z) == 0;
  }
}

} // end namespace llvm;

#endif