emitarm64.h

//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
//


#if defined(_TARGET_ARM64_)

// The ARM64 instructions are all 32 bits in size.
// we use an unsigned int to hold the encoded instructions.
// This typedef defines the type that we use to hold encoded instructions.
//
typedef unsigned int code_t;


    static bool strictArmAsm;

    /************************************************************************/
    /*         Routines that compute the size of / encode instructions      */
    /************************************************************************/

    struct CnsVal
    {
        ssize_t cnsVal;
#ifdef RELOC_SUPPORT
        bool cnsReloc;
#endif
    };

#ifdef  DEBUG

    /************************************************************************/
    /*             Debug-only routines to display instructions              */
    /************************************************************************/

    const   char *  emitFPregName   (unsigned       reg,
                                     bool           varName = true);
    const   char *  emitVectorRegName(regNumber reg);

    void            emitDispInst    (instruction ins);
    void            emitDispReloc   (int value, bool addComma);
    void            emitDispImm     (ssize_t imm, bool addComma, bool alwaysHex = false);
    void            emitDispFloatZero();
    void            emitDispFloatImm(ssize_t imm8);
    void            emitDispImmOptsLSL12(ssize_t imm, insOpts opt);
    void            emitDispCond    (insCond    cond);
    void            emitDispFlags   (insCflags  flags);
    void            emitDispBarrier (insBarrier barrier);
    void            emitDispShiftOpts(insOpts opt);
    void            emitDispExtendOpts(insOpts opt);
    void            emitDispLSExtendOpts(insOpts opt);
    void            emitDispReg     (regNumber reg, emitAttr  attr, bool addComma);
    void            emitDispVectorReg (regNumber reg, insOpts opt, bool addComma);
    void            emitDispVectorRegIndex(regNumber reg, emitAttr elemsize, ssize_t index, bool addComma);
    void            emitDispArrangement(insOpts opt);
    void            emitDispShiftedReg(regNumber reg, insOpts opt, ssize_t imm, emitAttr attr);
    void            emitDispExtendReg(regNumber reg, insOpts opt, ssize_t imm);
    void            emitDispAddrRI  (regNumber reg, insOpts opt, ssize_t imm);
    void            emitDispAddrRRExt(regNumber reg1, regNumber reg2, insOpts opt, bool isScaled, emitAttr size);

    void            emitDispIns     (instrDesc *id, bool isNew, bool doffs, bool asmfm, 
                                     unsigned offs = 0, BYTE * pCode = 0, size_t sz = 0,
                                     insGroup *ig = NULL);
#endif // DEBUG

    /************************************************************************/
    /*  Private members that deal with target-dependent instr. descriptors  */
    /************************************************************************/

private:

    instrDesc      *emitNewInstrAmd     (emitAttr attr, int dsp);
    instrDesc      *emitNewInstrAmdCns  (emitAttr attr, int dsp, int cns);

    instrDesc      *emitNewInstrCallDir (int        argCnt,
                                         VARSET_VALARG_TP GCvars,
                                         regMaskTP  gcrefRegs,
                                         regMaskTP  byrefRegs,
                                         emitAttr   retSize);

    instrDesc      *emitNewInstrCallInd( int        argCnt,
                                         ssize_t    disp,
                                         VARSET_VALARG_TP GCvars,
                                         regMaskTP  gcrefRegs,
                                         regMaskTP  byrefRegs,
                                         emitAttr   retSize);

    void            emitGetInsCns   (instrDesc *id, CnsVal *cv);
    ssize_t         emitGetInsAmdCns(instrDesc *id, CnsVal *cv);
    void            emitGetInsDcmCns(instrDesc *id, CnsVal *cv);
    ssize_t         emitGetInsAmdAny(instrDesc *id);

    /************************************************************************/
    /*               Private helpers for instruction output                 */
    /************************************************************************/

private:

    bool                    emitInsIsCompare(instruction ins);
    bool                    emitInsIsLoad   (instruction ins);
    bool                    emitInsIsStore  (instruction ins);
    bool                    emitInsIsLoadOrStore(instruction ins);
    emitAttr                emitInsTargetRegSize(instrDesc *id);
    emitAttr                emitInsLoadStoreSize(instrDesc *id);

    emitter::insFormat      emitInsFormat(instruction ins);

    emitter::code_t         emitInsCode(instruction ins, insFormat fmt);

    static unsigned         emitOutput_Instr(BYTE *dst, code_t code);


    // A helper method to return the natural scale for an EA 'size'
    static unsigned NaturalScale_helper(emitAttr size);

    // A helper method to perform a Rotate-Right shift operation 
    static UINT64  ROR_helper(UINT64 value, unsigned sh, unsigned width);

    // A helper method to perform a 'NOT' bitwise complement operation 
    static UINT64  NOT_helper(UINT64 value, unsigned width);

    // A helper method to perform a bit Replicate operation
    static UINT64  Replicate_helper(UINT64 value, unsigned width, emitAttr size);


    /************************************************************************
    *
    * This union is used to to encode/decode the special ARM64 immediate values
    * that is listed as imm(N,r,s) and referred to as 'bitmask immediate'
    */

    union bitMaskImm
    {
        struct {
            unsigned immS:6;   // bits 0..5
            unsigned immR:6;   // bits 6..11
            unsigned immN:1;   // bits 12
        };
        unsigned immNRS;  // concat N:R:S forming a 13-bit unsigned immediate
    };

    /************************************************************************
    *
    *  Convert between a 64-bit immediate and its 'bitmask immediate'
    *   representation imm(i16,hw)
    */

    static emitter::bitMaskImm emitEncodeBitMaskImm(INT64 imm,  emitAttr size);

    static INT64               emitDecodeBitMaskImm(const emitter::bitMaskImm bmImm,
                                                    emitAttr size);


    /************************************************************************
    *
    * This union is used to to encode/decode the special ARM64 immediate values
    * that is listed as imm(i16,hw) and referred to as 'halfword immediate'
    */

    union halfwordImm
    {
        struct {
            unsigned immVal:16;   // bits  0..15
            unsigned immHW:2;     // bits 16..17
        };
        unsigned immHWVal;  // concat HW:Val forming a 18-bit unsigned immediate
    };

    /************************************************************************
    *
    *  Convert between a 64-bit immediate and its 'halfword immediate'
    *   representation imm(i16,hw)
    */

    static emitter::halfwordImm emitEncodeHalfwordImm(INT64 imm,  emitAttr size);

    static INT64                emitDecodeHalfwordImm(const emitter::halfwordImm hwImm,
                                                      emitAttr size);

    /************************************************************************
    *
    * This union is used to encode/decode the special ARM64 immediate values
    * that is listed as imm(i16,by) and referred to as 'byteShifted immediate'
    */

    union byteShiftedImm
    {
        struct {
            unsigned immVal:8;   // bits  0..7
            unsigned immBY:2;    // bits  8..9
            unsigned immOnes:1;  // bit   10
        };
        unsigned immBSVal;  // concat Ones:BY:Val forming a 10-bit unsigned immediate
    };

    /************************************************************************
    *
    *  Convert between a 16/32-bit immediate and its 'byteShifted immediate'
    *   representation imm(i8,by)
    */

    static emitter::byteShiftedImm  emitEncodeByteShiftedImm(INT64 imm, emitAttr size, bool allow_MSL);

    static INT32  emitDecodeByteShiftedImm(const emitter::byteShiftedImm bsImm,
                                           emitAttr size);

    /************************************************************************
    *
    * This union is used to to encode/decode the special ARM64 immediate values
    * that are use for FMOV immediate and referred to as 'float 8-bit immediate'
    */

    union floatImm8
    {
        struct {
            unsigned immMant:4;   // bits 0..3
            unsigned immExp:3;    // bits 4..6
            unsigned immSign:1;   // bits 7
        };
        unsigned immFPIVal;  // concat Sign:Exp:Mant forming an 8-bit unsigned immediate
    };

    /************************************************************************
    *
    *  Convert between a double and its 'float 8-bit immediate' representation
    */

    static emitter::floatImm8   emitEncodeFloatImm8(double immDbl);

    static double               emitDecodeFloatImm8(const emitter::floatImm8 fpImm);

    /************************************************************************
    *
    *  This union is used to to encode/decode the cond, nzcv and imm5 values for 
    *   instructions that use them in the small constant immediate field
    */

    union condFlagsImm
    {
        struct {
            insCond    cond :4;     // bits  0..3
            insCflags  flags:4;     // bits  4..7
            unsigned   imm5 :5;     // bits  8..12
        };
        unsigned immCFVal;          // concat imm5:flags:cond forming an 13-bit unsigned immediate
    };

    // Returns an encoding for the specified register used in the 'Rd' position
    static code_t  insEncodeReg_Rd(regNumber reg);

    // Returns an encoding for the specified register used in the 'Rt' position
    static code_t  insEncodeReg_Rt(regNumber reg);

    // Returns an encoding for the specified register used in the 'Rn' position
    static code_t  insEncodeReg_Rn(regNumber reg);

    // Returns an encoding for the specified register used in the 'Rm' position
    static code_t  insEncodeReg_Rm(regNumber reg);

    // Returns an encoding for the specified register used in the 'Ra' position
    static code_t  insEncodeReg_Ra(regNumber reg);

    // Returns an encoding for the specified register used in the 'Vd' position
    static code_t  insEncodeReg_Vd(regNumber reg);

    // Returns an encoding for the specified register used in the 'Vt' position
    static code_t  insEncodeReg_Vt(regNumber reg);

    // Returns an encoding for the specified register used in the 'Vn' position
    static code_t  insEncodeReg_Vn(regNumber reg);

    // Returns an encoding for the specified register used in the 'Vm' position
    static code_t  insEncodeReg_Vm(regNumber reg);

    // Returns an encoding for the specified register used in the 'Va' position
    static code_t  insEncodeReg_Va(regNumber reg);

    // Returns an encoding for the imm which represents the condition code.
    static code_t  insEncodeCond(insCond cond);

    // Returns an encoding for the imm whioch represents the 'condition code' 
    //  with the lowest bit inverted (marked by invert(<cond>) in the architecture manual.
    static code_t  insEncodeInvertedCond(insCond cond);

    // Returns an encoding for the imm which represents the flags.
    static code_t  insEncodeFlags(insCflags flags);

    // Returns the encoding for the Shift Count bits to be used for Arm64 encodings
    static code_t  insEncodeShiftCount(ssize_t imm, emitAttr  size);

    // Returns the encoding to select the datasize for most Arm64 instructions
    static code_t  insEncodeDatasize(emitAttr  size);

    // Returns the encoding to select the datasize for the general load/store Arm64 instructions
    static code_t  insEncodeDatasizeLS(code_t code, emitAttr  size);

    // Returns the encoding to select the datasize for the vector load/store Arm64 instructions
    static code_t  insEncodeDatasizeVLS(code_t code, emitAttr size);

    // Returns the encoding to select the datasize for the vector load/store pair Arm64 instructions
    static code_t  insEncodeDatasizeVPLS(code_t code, emitAttr size);

    // Returns the encoding to select the datasize for bitfield Arm64 instructions
    static code_t  insEncodeDatasizeBF(code_t code, emitAttr  size);

    // Returns the encoding to select the vectorsize for SIMD Arm64 instructions
    static code_t  insEncodeVectorsize(emitAttr  size);

    // Returns the encoding to select 'index' for an Arm64 vector elem instruction
    static code_t  insEncodeVectorIndex(emitAttr elemsize, ssize_t index);

    // Returns the encoding to select 'index2' for an Arm64 'ins' elem instruction
    static code_t  insEncodeVectorIndex2(emitAttr elemsize, ssize_t index2);

    // Returns the encoding to select 'index' for an Arm64 'mul' elem instruction
    static code_t  insEncodeVectorIndexLMH(emitAttr elemsize, ssize_t index);

    // Returns the encoding to shift by 'shift' bits for an Arm64 vector or scalar instruction
    static code_t  insEncodeVectorShift(emitAttr size, ssize_t shift);

    // Returns the encoding to select the 1/2/4/8 byte elemsize for an Arm64 vector instruction
    static code_t  insEncodeElemsize(emitAttr  size);

    // Returns the encoding to select the 4/8 byte elemsize for an Arm64 float vector instruction
    static code_t  insEncodeFloatElemsize(emitAttr  size);

     // Returns the encoding to select the index for an Arm64 float vector by elem instruction
    static code_t  insEncodeFloatIndex(emitAttr elemsize, ssize_t index);

    // Returns the encoding to select the 'conversion' operation for a type 'fmt' Arm64 instruction
    static code_t  insEncodeConvertOpt(insFormat fmt, insOpts conversion);

    // Returns the encoding to have the Rn register of a ld/st reg be Pre/Post/Not indexed updated
    static code_t  insEncodeIndexedOpt(insOpts opt);

    // Returns the encoding to have the Rn register of a ld/st pair be Pre/Post/Not indexed updated
    static code_t  insEncodePairIndexedOpt(instruction ins, insOpts opt);

    // Returns the encoding to apply a Shift Type on the Rm register
    static code_t  insEncodeShiftType(insOpts opt);

    // Returns the encoding to apply a 12 bit left shift to the immediate
    static code_t  insEncodeShiftImm12(insOpts opt);

    // Returns the encoding to have the Rm register use an extend operation 
    static code_t  insEncodeExtend(insOpts opt);

    // Returns the encoding to scale the Rm register by {0,1,2,3,4} in an extend operation
    static code_t  insEncodeExtendScale(ssize_t imm);

    // Returns the encoding to have the Rm register be auto scaled by the ld/st size 
    static code_t  insEncodeReg3Scale(bool isScaled);

    // Returns true if 'reg' represents an integer register.
    static bool isIntegerRegister (regNumber reg)
                { return (reg >= REG_INT_FIRST) && (reg <= REG_INT_LAST); }

    // Returns true if 'value' is a legal unsigned immediate 8 bit encoding (such as for fMOV).
    static bool isValidUimm8(ssize_t value)
                { return (0 <= value) && (value <= 0xFFLL); };

    // Returns true if 'value' is a legal unsigned immediate 12 bit encoding (such as for CMP, CMN).
    static bool isValidUimm12(ssize_t value)
                { return (0 <= value) && (value <= 0xFFFLL); };

    // Returns true if 'value' is a legal unsigned immediate 16 bit encoding (such as for MOVZ, MOVN, MOVK).
    static bool isValidUimm16(ssize_t value)
                { return (0 <= value) && (value <= 0xFFFFLL); };

    // Returns true if 'value' is a legal signed immediate 26 bit encoding (such as for B or BL).
    static bool isValidSimm26(ssize_t value)
                { return (-0x2000000LL <= value) && (value <= 0x1FFFFFFLL); };

    // Returns true if 'value' is a legal signed immediate 19 bit encoding (such as for B.cond, CBNZ, CBZ).
    static bool isValidSimm19(ssize_t value)
                { return (-0x40000LL <= value) && (value <= 0x3FFFFLL); };

    // Returns true if 'value' is a legal signed immediate 14 bit encoding (such as for TBNZ, TBZ).
    static bool isValidSimm14(ssize_t value)
                { return (-0x2000LL <= value) && (value <= 0x1FFFLL); };

    // Returns true if 'value' represents a valid 'bitmask immediate' encoding.
    static bool isValidImmNRS (size_t value, emitAttr size)
                { return (value >= 0) && (value < 0x2000); }       // any unsigned 13-bit immediate

    // Returns true if 'value' represents a valid 'halfword immediate' encoding.
    static bool isValidImmHWVal (size_t value, emitAttr size)
                { return (value >= 0) && (value < 0x40000); }      // any unsigned 18-bit immediate

    // Returns true if 'value' represents a valid 'byteShifted immediate' encoding.
    static bool isValidImmBSVal (size_t value, emitAttr size)
                { return (value >= 0) && (value < 0x800); }        // any unsigned 11-bit immediate

    //  The return value replaces REG_ZR with REG_SP
    static regNumber encodingZRtoSP(regNumber reg)
                     { return (reg == REG_ZR) ? REG_SP : reg; }    // ZR (R31) encodes the SP register 

    //  The return value replaces REG_SP with REG_ZR
    static regNumber encodingSPtoZR(regNumber reg)
                     { return (reg == REG_SP) ? REG_ZR : reg; }    // SP is encoded using ZR (R31)

    //  For the given 'ins' returns the reverse instruction, if one exists, otherwise returns INS_INVALID
    static instruction  insReverse(instruction ins);

    //  For the given 'datasize' and 'elemsize' returns the insOpts that specifies the vector register arrangement
    static insOpts      optMakeArrangement(emitAttr datasize, emitAttr elemsize);

    //    For the given 'datasize' and 'opt' returns true if it specifies a valid vector register arrangement
    static bool         isValidArrangement(emitAttr datasize, insOpts opt);

    //  For the given 'arrangement' returns the 'datasize' specified by the vector register arrangement
    static emitAttr     optGetDatasize(insOpts arrangement);

    //  For the given 'arrangement' returns the 'elemsize' specified by the vector register arrangement
    static emitAttr     optGetElemsize(insOpts arrangement);

    //  For the given 'arrangement' returns the 'widen-arrangement' specified by the vector register arrangement
    static insOpts     optWidenElemsize(insOpts arrangement);

    //  For the given 'conversion' returns the 'dstsize' specified by the conversion option
    static emitAttr     optGetDstsize(insOpts conversion);

    //  For the given 'conversion' returns the 'srcsize' specified by the conversion option
    static emitAttr     optGetSrcsize(insOpts conversion);

    //    For the given 'datasize', 'elemsize' and 'index' returns true, if it specifies a valid 'index' 
    //    for an element of size 'elemsize' in a vector register of size 'datasize'
    static bool         isValidVectorIndex(emitAttr datasize, emitAttr elemsize, ssize_t index);

    /************************************************************************/
    /*           Public inline informational methods                        */
    /************************************************************************/

public:

    // true if this 'imm' can be encoded as a input operand to a mov instruction 
    static bool              emitIns_valid_imm_for_mov(INT64 imm, emitAttr size);

    // true if this 'imm' can be encoded as a input operand to a vector movi instruction 
    static bool              emitIns_valid_imm_for_movi(INT64 imm, emitAttr size);

    // true if this 'immDbl' can be encoded as a input operand to a fmov instruction 
    static bool              emitIns_valid_imm_for_fmov(double immDbl);

    // true if this 'imm' can be encoded as a input operand to an add instruction 
    static bool              emitIns_valid_imm_for_add(INT64 imm, emitAttr size);

    // true if this 'imm' can be encoded as a input operand to a cmp instruction 
    static bool              emitIns_valid_imm_for_cmp(INT64 imm, emitAttr size);

    // true if this 'imm' can be encoded as a input operand to an alu instruction 
    static bool              emitIns_valid_imm_for_alu(INT64 imm, emitAttr size);

    // true if 'imm' can use the left shifted by 12 bits encoding
    static bool              canEncodeWithShiftImmBy12(INT64 imm);

    // Normalize the 'imm' so that the upper bits, as defined by 'size' are zero
    static INT64             normalizeImm64(INT64 imm, emitAttr size);

    // Normalize the 'imm' so that the upper bits, as defined by 'size' are zero
    static INT32             normalizeImm32(INT32 imm, emitAttr size);

    // true if 'imm' can be encoded using a 'bitmask immediate', also returns the encoding if wbBMI is non-null
    static bool              canEncodeBitMaskImm(INT64  imm,  emitAttr  size,
                                                 emitter::bitMaskImm*  wbBMI = nullptr);

    // true if 'imm' can be encoded using a 'halfword immediate', also returns the encoding if wbHWI is non-null
    static bool              canEncodeHalfwordImm(INT64  imm,  emitAttr  size,
                                                  emitter::halfwordImm*  wbHWI = nullptr);

    // true if 'imm' can be encoded using a 'byteShifted immediate', also returns the encoding if wbBSI is non-null
    static bool              canEncodeByteShiftedImm(INT64  imm,  emitAttr  size, bool allow_MSL,
                                                     emitter::byteShiftedImm*  wbBSI = nullptr);

    // true if 'immDbl' can be encoded using a 'float immediate', also returns the encoding if wbFPI is non-null
    static bool              canEncodeFloatImm8(double  immDbl,  
                                                emitter::floatImm8*  wbFPI = nullptr);

    // Returns the number of bits used by the given 'size'.
    inline static unsigned   getBitWidth       (emitAttr  size)
                             { assert(size <= EA_8BYTE); return (unsigned)size * BITS_PER_BYTE; }

    // Returns true if the imm represents a valid bit shift or bit position for the given 'size' [0..31] or [0..63]
    inline static unsigned   isValidImmShift   (ssize_t imm, emitAttr  size)
                             { return (imm >= 0) && (imm < getBitWidth(size));      }

    inline static bool       isValidGeneralDatasize   (emitAttr  size)
                             { return (size == EA_8BYTE) || (size == EA_4BYTE);     }

    inline static bool       isValidScalarDatasize    (emitAttr  size)
                             { return (size == EA_8BYTE) || (size == EA_4BYTE);     }

    inline static bool       isValidVectorDatasize    (emitAttr  size)
                             { return (size == EA_16BYTE) || (size == EA_8BYTE);    }

    inline static bool       isValidGeneralLSDatasize (emitAttr  size)
                             { return (size == EA_8BYTE)  || (size == EA_4BYTE)  ||
                                      (size == EA_2BYTE)  || (size == EA_1BYTE);    }

    inline static bool       isValidVectorLSDatasize  (emitAttr  size)
                             { return (size == EA_16BYTE) ||
                                      (size == EA_8BYTE)  || (size == EA_4BYTE)  ||
                                      (size == EA_2BYTE)  || (size == EA_1BYTE);    }

    inline static bool       isValidVectorLSPDatasize (emitAttr  size)
                             { return (size == EA_16BYTE) ||
                                      (size == EA_8BYTE)  || (size == EA_4BYTE);   }

    inline static bool       isValidVectorElemsize    (emitAttr  size)
                             { return (size == EA_8BYTE) || (size == EA_4BYTE) ||
                                      (size == EA_2BYTE) || (size == EA_1BYTE);    }

    inline static bool       isValidVectorFcvtsize(emitAttr  size)
                             { return (size == EA_8BYTE) || (size == EA_4BYTE) ||
                                      (size == EA_2BYTE);                          }    

    inline static bool       isValidVectorElemsizeFloat (emitAttr  size)
                             { return (size == EA_8BYTE) || (size == EA_4BYTE);    }

    inline static bool       isGeneralRegister (regNumber reg)
                             { return (reg >= REG_INT_FIRST) && (reg <= REG_LR);    }   // Excludes REG_ZR

    inline static bool       isGeneralRegisterOrZR (regNumber reg)
                             { return (reg >= REG_INT_FIRST) && (reg <= REG_ZR);    }   // Includes REG_ZR

    inline static bool       isGeneralRegisterOrSP (regNumber reg)
                             { return isGeneralRegister(reg) || (reg == REG_SP);    }   // Includes REG_SP, Excludes REG_ZR

    inline static bool       isVectorRegister      (regNumber reg)
                             { return (reg >= REG_FP_FIRST && reg <= REG_FP_LAST);  }

    inline static bool       isFloatReg       (regNumber reg)
                             { return isVectorRegister(reg);             }
 
    inline static bool       insOptsNone       (insOpts  opt)
                             { return (opt == INS_OPTS_NONE);            }

    inline static bool       insOptsIndexed    (insOpts  opt)
                             { return (opt == INS_OPTS_PRE_INDEX)  ||
                                      (opt == INS_OPTS_POST_INDEX);      }

    inline static bool       insOptsPreIndex    (insOpts  opt)
                             { return (opt == INS_OPTS_PRE_INDEX);       }

    inline static bool       insOptsPostIndex   (insOpts  opt)
                             { return (opt == INS_OPTS_POST_INDEX);      }

    inline static bool       insOptsLSL12       (insOpts  opt)             // special 12-bit shift only used for imm12
                             { return (opt == INS_OPTS_LSL12);           }

    inline static bool       insOptsAnyShift    (insOpts  opt)
                             { return ((opt >= INS_OPTS_LSL) && 
                                       (opt <= INS_OPTS_ROR)    );       }

    inline static bool       insOptsAluShift    (insOpts  opt)             // excludes ROR
                             { return ((opt >= INS_OPTS_LSL) && 
                                       (opt <= INS_OPTS_ASR)    );       }

    inline static bool       insOptsVectorImmShift (insOpts  opt)
                             { return ((opt == INS_OPTS_LSL) || 
                                       (opt == INS_OPTS_MSL)    );       }

    inline static bool       insOptsLSL         (insOpts  opt)
                             { return (opt == INS_OPTS_LSL);             }

    inline static bool       insOptsLSR         (insOpts  opt)
                             { return (opt == INS_OPTS_LSR);             }

    inline static bool       insOptsASR         (insOpts  opt)
                             { return (opt == INS_OPTS_ASR);             }

    inline static bool       insOptsROR         (insOpts  opt)
                             { return (opt == INS_OPTS_ROR);             }

    inline static bool       insOptsAnyExtend   (insOpts  opt)
                             { return ((opt >= INS_OPTS_UXTB) && 
                                       (opt <= INS_OPTS_SXTX)    );      }

    inline static bool       insOptsLSExtend    (insOpts  opt)
                             { return ((opt == INS_OPTS_NONE) || (opt == INS_OPTS_LSL)  || 
                                       (opt == INS_OPTS_UXTW) || (opt == INS_OPTS_SXTW) ||
                                       (opt == INS_OPTS_UXTX) || (opt == INS_OPTS_SXTX)    );  }

    inline static bool       insOpts32BitExtend (insOpts  opt)
                             { return ((opt == INS_OPTS_UXTW) || (opt == INS_OPTS_SXTW));  }

    inline static bool       insOpts64BitExtend (insOpts  opt)
                             { return ((opt == INS_OPTS_UXTX) || (opt == INS_OPTS_SXTX));  }

    inline static bool       insOptsAnyArrangement(insOpts  opt)
                             { return ((opt >= INS_OPTS_8B) && (opt <= INS_OPTS_2D));  }

    inline static bool       insOptsConvertFloatToFloat (insOpts  opt)
                             { return ((opt >= INS_OPTS_S_TO_D) && (opt <= INS_OPTS_D_TO_H));  }

    inline static bool       insOptsConvertFloatToInt   (insOpts  opt)
                             { return ((opt >= INS_OPTS_S_TO_4BYTE) && (opt <= INS_OPTS_D_TO_8BYTE));  }

    inline static bool       insOptsConvertIntToFloat   (insOpts  opt)
                             { return ((opt >= INS_OPTS_4BYTE_TO_S) && (opt <= INS_OPTS_8BYTE_TO_D));  }

    static bool             isValidImmCond          (ssize_t imm);
    static bool             isValidImmCondFlags     (ssize_t imm);
    static bool             isValidImmCondFlagsImm5 (ssize_t imm);

    /************************************************************************/
    /*           The public entry points to output instructions             */
    /************************************************************************/

public:

    void            emitIns        (instruction ins);

    void            emitIns_I      (instruction ins,
                                    emitAttr    attr,
                                    ssize_t     imm);

    void            emitIns_R      (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg);

    void            emitIns_R_I    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg,
                                    ssize_t     imm,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_F    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg,
                                    double      immDbl,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    insFlags    flags)
    {
        emitIns_R_R(ins,attr,reg1,reg2);
    }

    void            emitIns_R_I_I  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    ssize_t     imm1,
                                    ssize_t     imm2,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R_I  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    ssize_t     imm,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R_R  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    regNumber   reg3,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R_R_I(instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    regNumber   reg3,
                                    ssize_t     imm,
                                    insOpts     opt   = INS_OPTS_NONE);

    void            emitIns_R_R_R_Ext(instruction ins,
                                      emitAttr    attr,
                                      regNumber   reg1,
                                      regNumber   reg2,
                                      regNumber   reg3,
                                      insOpts     opt = INS_OPTS_NONE,
                                      int         shiftAmount = -1);

    void            emitIns_R_R_I_I(instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    int         imm1,
                                    int         imm2);

    void            emitIns_R_R_R_R(instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg1,
                                    regNumber   reg2,
                                    regNumber   reg3,
                                    regNumber   reg4);

    void            emitIns_R_COND (instruction ins,
                                    emitAttr    attr,
                                    regNumber   reg,
                                    insCond     cond);

    void            emitIns_R_R_COND (instruction ins,
                                      emitAttr    attr,
                                      regNumber   reg1,
                                      regNumber   reg2,
                                      insCond     cond);

    void            emitIns_R_R_R_COND (instruction ins,
                                        emitAttr    attr,
                                        regNumber   reg1,
                                        regNumber   reg2,
                                        regNumber   reg3,
                                        insCond     cond);

    void            emitIns_R_R_FLAGS_COND (instruction ins,
                                            emitAttr    attr,
                                            regNumber   reg1,
                                            regNumber   reg2,
                                            insCflags   flags,
                                            insCond     cond);

    void            emitIns_R_I_FLAGS_COND (instruction ins,
                                            emitAttr    attr,
                                            regNumber   reg1,
                                            int         imm,
                                            insCflags   flags,
                                            insCond     cond);

    void            emitIns_BARR   (instruction  ins,
                                    insBarrier   barrier);

    void            emitIns_C      (instruction  ins,
                                    emitAttr     attr,
                                    CORINFO_FIELD_HANDLE fdlHnd,
                                    int          offs);

    void            emitIns_S      (instruction ins,
                                    emitAttr    attr,
                                    int         varx,
                                    int         offs);

    void            emitIns_S_R    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    int         varx,
                                    int         offs);

    void            emitIns_R_S    (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    int         varx,
                                    int         offs);

    void            emitIns_S_I    (instruction ins,
                                    emitAttr    attr,
                                    int         varx,
                                    int         offs,
                                    int         val);

    void            emitIns_R_C    (instruction  ins,
                                    emitAttr     attr,
                                    regNumber    reg,
                                    CORINFO_FIELD_HANDLE fldHnd,
                                    int          offs);

    void            emitIns_C_R    (instruction  ins,
                                    emitAttr     attr,
                                    CORINFO_FIELD_HANDLE fldHnd,
                                    regNumber    reg,
                                    int          offs);

    void            emitIns_C_I    (instruction  ins,
                                    emitAttr     attr,
                                    CORINFO_FIELD_HANDLE fdlHnd,
                                    ssize_t      offs,
                                    ssize_t      val);

    void            emitIns_R_L    (instruction   ins,
                                    emitAttr      attr,
                                    BasicBlock *  dst,
                                    regNumber     reg);
    
    void            emitIns_R_D    (instruction   ins,
                                    emitAttr      attr,
                                    unsigned      offs,
                                    regNumber     reg);

    void            emitIns_J_R    (instruction ins,
                                    emitAttr    attr,
                                    BasicBlock *dst,
                                    regNumber   reg);

    void            emitIns_I_AR   (instruction ins,
                                    emitAttr    attr,
                                    int         val,
                                    regNumber   reg,
                                    int         offs,
                                    int         memCookie = 0,
                                    void *      clsCookie = NULL);

    void            emitIns_R_AR   (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    regNumber   reg,
                                    int         offs,
                                    int         memCookie = 0,
                                    void *      clsCookie = NULL);

    void            emitIns_R_AI   (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    ssize_t     disp);

    void            emitIns_AR_R   (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    regNumber   reg,
                                    int         offs,
                                    int         memCookie = 0,
                                    void *      clsCookie = NULL);

    void            emitIns_R_ARR  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    regNumber   reg,
                                    regNumber   rg2,
                                    int         disp);

    void            emitIns_ARR_R  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    regNumber   reg,
                                    regNumber   rg2,
                                    int         disp);

    void            emitIns_R_ARX  (instruction ins,
                                    emitAttr    attr,
                                    regNumber   ireg,
                                    regNumber   reg,
                                    regNumber   rg2,
                                    unsigned    mul,
                                    int         disp);

    enum EmitCallType
    {

    // I have included here, but commented out, all the values used by the x86 emitter.
    // However, ARM has a much reduced instruction set, and so the ARM emitter only
    // supports a subset of the x86 variants.  By leaving them commented out, it becomes
    // a compile time error if code tries to use them (and hopefully see this comment
    // and know why they are unavailible on ARM), while making it easier to stay
    // in-sync with x86 and possibly add them back in if needed.

        EC_FUNC_TOKEN,          //   Direct call to a helper/static/nonvirtual/global method
    //  EC_FUNC_TOKEN_INDIR,    // Indirect call to a helper/static/nonvirtual/global method
        EC_FUNC_ADDR,           // Direct call to an absolute address

    //  EC_FUNC_VIRTUAL,        // Call to a virtual method (using the vtable)
        EC_INDIR_R,             // Indirect call via register
    //  EC_INDIR_SR,            // Indirect call via stack-reference (local var)
    //  EC_INDIR_C,             // Indirect call via static class var
    //  EC_INDIR_ARD,           // Indirect call via an addressing mode

        EC_COUNT
    };

    void            emitIns_Call   (EmitCallType    callType,
                                    CORINFO_METHOD_HANDLE methHnd,
                                    INDEBUG_LDISASM_COMMA(CORINFO_SIG_INFO* sigInfo)     // used to report call sites to the EE
                                    void*           addr,
                                    ssize_t         argSize,
                                    emitAttr        retSize,
                                    VARSET_VALARG_TP ptrVars,
                                    regMaskTP       gcrefRegs,
                                    regMaskTP       byrefRegs,
                                    IL_OFFSETX      ilOffset = BAD_IL_OFFSET,
                                    regNumber       ireg = REG_NA,
                                    regNumber       xreg = REG_NA,                                    
                                    unsigned        xmul = 0,
                                    ssize_t         disp = 0,
                                    bool            isJump = false,
                                    bool            isNoGC = false,
                                    bool            isProfLeaveCB = false);

    BYTE*           emitOutputLJ  (insGroup  *ig, BYTE *dst, instrDesc *i);
    unsigned        emitOutputCall(insGroup  *ig, BYTE *dst, instrDesc *i, code_t code);

/*****************************************************************************
 *
 *  Given an instrDesc, return true if it's a conditional jump.
 */

inline bool        emitIsCondJump(instrDesc *jmp)
{
    return (jmp->idInsFmt() == IF_BI_0B);
}


/*****************************************************************************
 *
 *  Given an instrDesc, return true if it's a compare and jump.
 */

inline bool        emitIsCmpJump(instrDesc *jmp)
{
    return ((jmp->idInsFmt() == IF_BI_1A) ||
            (jmp->idInsFmt() == IF_BI_1B));
}

/*****************************************************************************
 *
 *  Given a instrDesc, return true if it's an unconditional jump.
 */

inline bool        emitIsUncondJump(instrDesc *jmp)
{
    return (jmp->idInsFmt() == IF_BI_0A);
}

/*****************************************************************************
 *
 *  Given a instrDesc, return true if it's a direct call.
 */

inline bool        emitIsDirectCall(instrDesc *call)
{
    return (call->idInsFmt() == IF_BI_0C);
}

/*****************************************************************************
 *
 *  Given a instrDesc, return true if it's a load label instruction.
 */

inline bool        emitIsLoadLabel(instrDesc *jmp)
{
    return (jmp->idInsFmt() == IF_DI_1E); // adr or adrp
}

#endif // _TARGET_ARM64_