AArch64AddressingModes.h

//===- AArch64AddressingModes.h - AArch64 Addressing Modes ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the AArch64 addressing mode implementation stuff.
//
//===----------------------------------------------------------------------===//

#ifndef CS_AARCH64_ADDRESSINGMODES_H
#define CS_AARCH64_ADDRESSINGMODES_H

/* Capstone Disassembly Engine */
/* By Nguyen Anh Quynh <[email protected]>, 2013-2019 */

#include "../../MathExtras.h"

/// AArch64_AM - AArch64 Addressing Mode Stuff

//===----------------------------------------------------------------------===//
// Shifts
//
typedef enum AArch64_AM_ShiftExtendType {
	AArch64_AM_InvalidShiftExtend = -1,
	AArch64_AM_LSL = 0,
	AArch64_AM_LSR,
	AArch64_AM_ASR,
	AArch64_AM_ROR,
	AArch64_AM_MSL,

	AArch64_AM_UXTB,
	AArch64_AM_UXTH,
	AArch64_AM_UXTW,
	AArch64_AM_UXTX,

	AArch64_AM_SXTB,
	AArch64_AM_SXTH,
	AArch64_AM_SXTW,
	AArch64_AM_SXTX,
} AArch64_AM_ShiftExtendType;

/// getShiftName - Get the string encoding for the shift type.
static inline const char *AArch64_AM_getShiftExtendName(AArch64_AM_ShiftExtendType ST)
{
	switch (ST) {
		default: return NULL; // never reach
		case AArch64_AM_LSL: return "lsl";
		case AArch64_AM_LSR: return "lsr";
		case AArch64_AM_ASR: return "asr";
		case AArch64_AM_ROR: return "ror";
		case AArch64_AM_MSL: return "msl";
		case AArch64_AM_UXTB: return "uxtb";
		case AArch64_AM_UXTH: return "uxth";
		case AArch64_AM_UXTW: return "uxtw";
		case AArch64_AM_UXTX: return "uxtx";
		case AArch64_AM_SXTB: return "sxtb";
		case AArch64_AM_SXTH: return "sxth";
		case AArch64_AM_SXTW: return "sxtw";
		case AArch64_AM_SXTX: return "sxtx";
	}
}

/// getShiftType - Extract the shift type.
static inline AArch64_AM_ShiftExtendType AArch64_AM_getShiftType(unsigned Imm)
{
	switch ((Imm >> 6) & 0x7) {
		default: return AArch64_AM_InvalidShiftExtend;
		case 0: return AArch64_AM_LSL;
		case 1: return AArch64_AM_LSR;
		case 2: return AArch64_AM_ASR;
		case 3: return AArch64_AM_ROR;
		case 4: return AArch64_AM_MSL;
	}
}

/// getShiftValue - Extract the shift value.
static inline unsigned AArch64_AM_getShiftValue(unsigned Imm)
{
	return Imm & 0x3f;
}

static inline unsigned AArch64_AM_getShifterImm(AArch64_AM_ShiftExtendType ST, unsigned Imm)
{
	// assert((Imm & 0x3f) == Imm && "Illegal shifted immedate value!");
	unsigned STEnc = 0;

	switch (ST) {
		default:  // llvm_unreachable("Invalid shift requested");
		case AArch64_AM_LSL: STEnc = 0; break;
		case AArch64_AM_LSR: STEnc = 1; break;
		case AArch64_AM_ASR: STEnc = 2; break;
		case AArch64_AM_ROR: STEnc = 3; break;
		case AArch64_AM_MSL: STEnc = 4; break;
	}

	return (STEnc << 6) | (Imm & 0x3f);
}

//===----------------------------------------------------------------------===//
// Extends
//

/// getArithShiftValue - get the arithmetic shift value.
static inline unsigned AArch64_AM_getArithShiftValue(unsigned Imm)
{
	return Imm & 0x7;
}

/// getExtendType - Extract the extend type for operands of arithmetic ops.
static inline AArch64_AM_ShiftExtendType AArch64_AM_getExtendType(unsigned Imm)
{
	// assert((Imm & 0x7) == Imm && "invalid immediate!");
	switch (Imm) {
		default: // llvm_unreachable("Compiler bug!");
		case 0: return AArch64_AM_UXTB;
		case 1: return AArch64_AM_UXTH;
		case 2: return AArch64_AM_UXTW;
		case 3: return AArch64_AM_UXTX;
		case 4: return AArch64_AM_SXTB;
		case 5: return AArch64_AM_SXTH;
		case 6: return AArch64_AM_SXTW;
		case 7: return AArch64_AM_SXTX;
	}
}

static inline AArch64_AM_ShiftExtendType AArch64_AM_getArithExtendType(unsigned Imm)
{
	return AArch64_AM_getExtendType((Imm >> 3) & 0x7);
}

/// Mapping from extend bits to required operation:
///   shifter: 000 ==> uxtb
///            001 ==> uxth
///            010 ==> uxtw
///            011 ==> uxtx
///            100 ==> sxtb
///            101 ==> sxth
///            110 ==> sxtw
///            111 ==> sxtx
static inline unsigned AArch64_AM_getExtendEncoding(AArch64_AM_ShiftExtendType ET)
{
	switch (ET) {
		default: // llvm_unreachable("Invalid extend type requested");
		case AArch64_AM_UXTB: return 0; break;
		case AArch64_AM_UXTH: return 1; break;
		case AArch64_AM_UXTW: return 2; break;
		case AArch64_AM_UXTX: return 3; break;
		case AArch64_AM_SXTB: return 4; break;
		case AArch64_AM_SXTH: return 5; break;
		case AArch64_AM_SXTW: return 6; break;
		case AArch64_AM_SXTX: return 7; break;
	}
}

/// getArithExtendImm - Encode the extend type and shift amount for an
///                     arithmetic instruction:
///   imm:     3-bit extend amount
///   {5-3}  = shifter
///   {2-0}  = imm3
static inline unsigned AArch64_AM_getArithExtendImm(AArch64_AM_ShiftExtendType ET, unsigned Imm)
{
	// assert((Imm & 0x7) == Imm && "Illegal shifted immedate value!");
	return (AArch64_AM_getExtendEncoding(ET) << 3) | (Imm & 0x7);
}

/// getMemDoShift - Extract the "do shift" flag value for load/store
/// instructions.
static inline bool AArch64_AM_getMemDoShift(unsigned Imm)
{
	return (Imm & 0x1) != 0;
}

/// getExtendType - Extract the extend type for the offset operand of
/// loads/stores.
static inline AArch64_AM_ShiftExtendType AArch64_AM_getMemExtendType(unsigned Imm)
{
	return AArch64_AM_getExtendType((Imm >> 1) & 0x7);
}

static inline uint64_t ror(uint64_t elt, unsigned size)
{
	return ((elt & 1) << (size-1)) | (elt >> 1);
}

/// processLogicalImmediate - Determine if an immediate value can be encoded
/// as the immediate operand of a logical instruction for the given register
/// size.  If so, return true with "encoding" set to the encoded value in
/// the form N:immr:imms.
static inline bool AArch64_AM_processLogicalImmediate(uint64_t Imm, unsigned RegSize, uint64_t *Encoding)
{
	unsigned Size, Immr, N;
	uint32_t CTO, I;
	uint64_t Mask, NImms;

	if (Imm == 0ULL || Imm == ~0ULL ||
		(RegSize != 64 && (Imm >> RegSize != 0 || Imm == (~0ULL >> (64 - RegSize))))) {
		return false;
	}

	// First, determine the element size.
	Size = RegSize;
	do {
		uint64_t Mask;

		Size /= 2;
		Mask = (1ULL << Size) - 1;
		if ((Imm & Mask) != ((Imm >> Size) & Mask)) {
			Size *= 2;
			break;
		}
	} while (Size > 2);

	// Second, determine the rotation to make the element be: 0^m 1^n.
	Mask = ((uint64_t)-1LL) >> (64 - Size);
	Imm &= Mask;

	if (isShiftedMask_64(Imm)) {
		I = CountTrailingZeros_32(Imm);
		// assert(I < 64 && "undefined behavior");
		CTO = CountTrailingOnes_32(Imm >> I);
	} else {
		unsigned CLO;

		Imm |= ~Mask;
		if (!isShiftedMask_64(~Imm))
			return false;

		CLO = CountLeadingOnes_32(Imm);
		I = 64 - CLO;
		CTO = CLO + CountTrailingOnes_32(Imm) - (64 - Size);
	}

	// Encode in Immr the number of RORs it would take to get *from* 0^m 1^n
	// to our target value, where I is the number of RORs to go the opposite
	// direction.
	// assert(Size > I && "I should be smaller than element size");
	Immr = (Size - I) & (Size - 1);

	// If size has a 1 in the n'th bit, create a value that has zeroes in
	// bits [0, n] and ones above that.
	NImms = ~(Size-1) << 1;

	// Or the CTO value into the low bits, which must be below the Nth bit
	// bit mentioned above.
	NImms |= (CTO-1);

	// Extract the seventh bit and toggle it to create the N field.
	N = ((NImms >> 6) & 1) ^ 1;

	*Encoding = (N << 12) | (Immr << 6) | (NImms & 0x3f);

	return true;
}

/// isLogicalImmediate - Return true if the immediate is valid for a logical
/// immediate instruction of the given register size. Return false otherwise.
static inline bool isLogicalImmediate(uint64_t imm, unsigned regSize)
{
	uint64_t encoding;
	return AArch64_AM_processLogicalImmediate(imm, regSize, &encoding);
}

/// encodeLogicalImmediate - Return the encoded immediate value for a logical
/// immediate instruction of the given register size.
static inline uint64_t AArch64_AM_encodeLogicalImmediate(uint64_t imm, unsigned regSize)
{
	uint64_t encoding = 0;

	bool res = AArch64_AM_processLogicalImmediate(imm, regSize, &encoding);
	// assert(res && "invalid logical immediate");
	(void)res;

	return encoding;
}

/// decodeLogicalImmediate - Decode a logical immediate value in the form
/// "N:immr:imms" (where the immr and imms fields are each 6 bits) into the
/// integer value it represents with regSize bits.
static inline uint64_t AArch64_AM_decodeLogicalImmediate(uint64_t val, unsigned regSize)
{
	// Extract the N, imms, and immr fields.
	unsigned N = (val >> 12) & 1;
	unsigned immr = (val >> 6) & 0x3f;
	unsigned imms = val & 0x3f;
	unsigned i, size, R, S;
	uint64_t pattern;

	// assert((regSize == 64 || N == 0) && "undefined logical immediate encoding");
	int len = 31 - CountLeadingZeros_32((N << 6) | (~imms & 0x3f));

	// assert(len >= 0 && "undefined logical immediate encoding");
	size = (1 << len);
	R = immr & (size - 1);
	S = imms & (size - 1);

	// assert(S != size - 1 && "undefined logical immediate encoding");
	pattern = (1ULL << (S + 1)) - 1;

	for (i = 0; i < R; ++i)
		pattern = ror(pattern, size);

	// Replicate the pattern to fill the regSize.
	while (size != regSize) {
		pattern |= (pattern << size);
		size *= 2;
	}

	return pattern;
}

/// isValidDecodeLogicalImmediate - Check to see if the logical immediate value
/// in the form "N:immr:imms" (where the immr and imms fields are each 6 bits)
/// is a valid encoding for an integer value with regSize bits.
static inline bool AArch64_AM_isValidDecodeLogicalImmediate(uint64_t val, unsigned regSize)
{
	unsigned size, S;
	int len;
	// Extract the N and imms fields needed for checking.
	unsigned N = (val >> 12) & 1;
	unsigned imms = val & 0x3f;

	if (regSize == 32 && N != 0) // undefined logical immediate encoding
		return false;
	len = 31 - CountLeadingZeros_32((N << 6) | (~imms & 0x3f));
	if (len < 0) // undefined logical immediate encoding
		return false;
	size = (1 << len);
	S = imms & (size - 1);
	if (S == size - 1) // undefined logical immediate encoding
		return false;

	return true;
}

//===----------------------------------------------------------------------===//
// Floating-point Immediates
//
static inline float AArch64_AM_getFPImmFloat(unsigned Imm)
{
	// We expect an 8-bit binary encoding of a floating-point number here.
	union {
		uint32_t I;
		float F;
	} FPUnion;

	uint8_t Sign = (Imm >> 7) & 0x1;
	uint8_t Exp = (Imm >> 4) & 0x7;
	uint8_t Mantissa = Imm & 0xf;

	//   8-bit FP    iEEEE Float Encoding
	//   abcd efgh   aBbbbbbc defgh000 00000000 00000000
	//
	// where B = NOT(b);

	FPUnion.I = 0;
	FPUnion.I |= ((uint32_t)Sign) << 31;
	FPUnion.I |= ((Exp & 0x4) != 0 ? 0 : 1) << 30;
	FPUnion.I |= ((Exp & 0x4) != 0 ? 0x1f : 0) << 25;
	FPUnion.I |= (Exp & 0x3) << 23;
	FPUnion.I |= Mantissa << 19;

	return FPUnion.F;
}

//===--------------------------------------------------------------------===//
// AdvSIMD Modified Immediates
//===--------------------------------------------------------------------===//

// 0x00 0x00 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh
static inline bool AArch64_AM_isAdvSIMDModImmType1(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0xffffff00ffffff00ULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType1(uint64_t Imm)
{
	return (Imm & 0xffULL);
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType1(uint8_t Imm)
{
	uint64_t EncVal = Imm;

	return (EncVal << 32) | EncVal;
}

// 0x00 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType2(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0xffff00ffffff00ffULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType2(uint64_t Imm)
{
	return (Imm & 0xff00ULL) >> 8;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType2(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 40) | (EncVal << 8);
}

// 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh 0x00 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType3(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0xff00ffffff00ffffULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType3(uint64_t Imm)
{
	return (Imm & 0xff0000ULL) >> 16;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType3(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 48) | (EncVal << 16);
}

// abcdefgh 0x00 0x00 0x00 abcdefgh 0x00 0x00 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType4(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0x00ffffff00ffffffULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType4(uint64_t Imm)
{
	return (Imm & 0xff000000ULL) >> 24;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType4(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 56) | (EncVal << 24);
}

// 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh
static inline bool AArch64_AM_isAdvSIMDModImmType5(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		(((Imm & 0x00ff0000ULL) >> 16) == (Imm & 0x000000ffULL)) &&
		((Imm & 0xff00ff00ff00ff00ULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType5(uint64_t Imm)
{
	return (Imm & 0xffULL);
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType5(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 48) | (EncVal << 32) | (EncVal << 16) | EncVal;
}

// abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType6(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		(((Imm & 0xff000000ULL) >> 16) == (Imm & 0x0000ff00ULL)) &&
		((Imm & 0x00ff00ff00ff00ffULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType6(uint64_t Imm)
{
	return (Imm & 0xff00ULL) >> 8;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType6(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 56) | (EncVal << 40) | (EncVal << 24) | (EncVal << 8);
}

// 0x00 0x00 abcdefgh 0xFF 0x00 0x00 abcdefgh 0xFF
static inline bool AArch64_AM_isAdvSIMDModImmType7(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0xffff00ffffff00ffULL) == 0x000000ff000000ffULL);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType7(uint64_t Imm)
{
	return (Imm & 0xff00ULL) >> 8;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType7(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 40) | (EncVal << 8) | 0x000000ff000000ffULL;
}

// 0x00 abcdefgh 0xFF 0xFF 0x00 abcdefgh 0xFF 0xFF
static inline bool AArch64_AM_isAdvSIMDModImmType8(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm & 0xff00ffffff00ffffULL) == 0x0000ffff0000ffffULL);
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType8(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	return (EncVal << 48) | (EncVal << 16) | 0x0000ffff0000ffffULL;
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType8(uint64_t Imm)
{
	return (Imm & 0x00ff0000ULL) >> 16;
}

// abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh
static inline bool AArch64_AM_isAdvSIMDModImmType9(uint64_t Imm)
{
	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		((Imm >> 48) == (Imm & 0x0000ffffULL)) &&
		((Imm >> 56) == (Imm & 0x000000ffULL));
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType9(uint64_t Imm)
{
	return (Imm & 0xffULL);
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType9(uint8_t Imm)
{
	uint64_t EncVal = Imm;
	EncVal |= (EncVal << 8);
	EncVal |= (EncVal << 16);
	EncVal |= (EncVal << 32);

	return EncVal;
}

// aaaaaaaa bbbbbbbb cccccccc dddddddd eeeeeeee ffffffff gggggggg hhhhhhhh
// cmode: 1110, op: 1
static inline bool AArch64_AM_isAdvSIMDModImmType10(uint64_t Imm)
{
	uint64_t ByteA = Imm & 0xff00000000000000ULL;
	uint64_t ByteB = Imm & 0x00ff000000000000ULL;
	uint64_t ByteC = Imm & 0x0000ff0000000000ULL;
	uint64_t ByteD = Imm & 0x000000ff00000000ULL;
	uint64_t ByteE = Imm & 0x00000000ff000000ULL;
	uint64_t ByteF = Imm & 0x0000000000ff0000ULL;
	uint64_t ByteG = Imm & 0x000000000000ff00ULL;
	uint64_t ByteH = Imm & 0x00000000000000ffULL;

	return (ByteA == 0ULL || ByteA == 0xff00000000000000ULL) &&
		(ByteB == 0ULL || ByteB == 0x00ff000000000000ULL) &&
		(ByteC == 0ULL || ByteC == 0x0000ff0000000000ULL) &&
		(ByteD == 0ULL || ByteD == 0x000000ff00000000ULL) &&
		(ByteE == 0ULL || ByteE == 0x00000000ff000000ULL) &&
		(ByteF == 0ULL || ByteF == 0x0000000000ff0000ULL) &&
		(ByteG == 0ULL || ByteG == 0x000000000000ff00ULL) &&
		(ByteH == 0ULL || ByteH == 0x00000000000000ffULL);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType10(uint64_t Imm)
{
	uint8_t BitA = (Imm & 0xff00000000000000ULL) != 0;
	uint8_t BitB = (Imm & 0x00ff000000000000ULL) != 0;
	uint8_t BitC = (Imm & 0x0000ff0000000000ULL) != 0;
	uint8_t BitD = (Imm & 0x000000ff00000000ULL) != 0;
	uint8_t BitE = (Imm & 0x00000000ff000000ULL) != 0;
	uint8_t BitF = (Imm & 0x0000000000ff0000ULL) != 0;
	uint8_t BitG = (Imm & 0x000000000000ff00ULL) != 0;
	uint8_t BitH = (Imm & 0x00000000000000ffULL) != 0;

	uint8_t EncVal = BitA;

	EncVal <<= 1;
	EncVal |= BitB;
	EncVal <<= 1;
	EncVal |= BitC;
	EncVal <<= 1;
	EncVal |= BitD;
	EncVal <<= 1;
	EncVal |= BitE;
	EncVal <<= 1;
	EncVal |= BitF;
	EncVal <<= 1;
	EncVal |= BitG;
	EncVal <<= 1;
	EncVal |= BitH;

	return EncVal;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType10(uint8_t Imm)
{
	uint64_t EncVal = 0;

	if (Imm & 0x80)
		EncVal |= 0xff00000000000000ULL;

	if (Imm & 0x40)
		EncVal |= 0x00ff000000000000ULL;

	if (Imm & 0x20)
		EncVal |= 0x0000ff0000000000ULL;

	if (Imm & 0x10)
		EncVal |= 0x000000ff00000000ULL;

	if (Imm & 0x08)
		EncVal |= 0x00000000ff000000ULL;

	if (Imm & 0x04)
		EncVal |= 0x0000000000ff0000ULL;

	if (Imm & 0x02)
		EncVal |= 0x000000000000ff00ULL;

	if (Imm & 0x01)
		EncVal |= 0x00000000000000ffULL;

	return EncVal;
}

// aBbbbbbc defgh000 0x00 0x00 aBbbbbbc defgh000 0x00 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType11(uint64_t Imm)
{
	uint64_t BString = (Imm & 0x7E000000ULL) >> 25;

	return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
		(BString == 0x1f || BString == 0x20) &&
		((Imm & 0x0007ffff0007ffffULL) == 0);
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType11(uint64_t Imm)
{
	uint8_t BitA = (Imm & 0x80000000ULL) != 0;
	uint8_t BitB = (Imm & 0x20000000ULL) != 0;
	uint8_t BitC = (Imm & 0x01000000ULL) != 0;
	uint8_t BitD = (Imm & 0x00800000ULL) != 0;
	uint8_t BitE = (Imm & 0x00400000ULL) != 0;
	uint8_t BitF = (Imm & 0x00200000ULL) != 0;
	uint8_t BitG = (Imm & 0x00100000ULL) != 0;
	uint8_t BitH = (Imm & 0x00080000ULL) != 0;

	uint8_t EncVal = BitA;
	EncVal <<= 1;
	EncVal |= BitB;
	EncVal <<= 1;
	EncVal |= BitC;
	EncVal <<= 1;
	EncVal |= BitD;
	EncVal <<= 1;
	EncVal |= BitE;
	EncVal <<= 1;
	EncVal |= BitF;
	EncVal <<= 1;
	EncVal |= BitG;
	EncVal <<= 1;
	EncVal |= BitH;

	return EncVal;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType11(uint8_t Imm)
{
	uint64_t EncVal = 0;

	if (Imm & 0x80)
		EncVal |= 0x80000000ULL;

	if (Imm & 0x40)
		EncVal |= 0x3e000000ULL;
	else
		EncVal |= 0x40000000ULL;

	if (Imm & 0x20)
		EncVal |= 0x01000000ULL;

	if (Imm & 0x10)
		EncVal |= 0x00800000ULL;

	if (Imm & 0x08)
		EncVal |= 0x00400000ULL;

	if (Imm & 0x04)
		EncVal |= 0x00200000ULL;

	if (Imm & 0x02)
		EncVal |= 0x00100000ULL;

	if (Imm & 0x01)
		EncVal |= 0x00080000ULL;

	return (EncVal << 32) | EncVal;
}

// aBbbbbbb bbcdefgh 0x00 0x00 0x00 0x00 0x00 0x00
static inline bool AArch64_AM_isAdvSIMDModImmType12(uint64_t Imm)
{
	uint64_t BString = (Imm & 0x7fc0000000000000ULL) >> 54;
	return ((BString == 0xff || BString == 0x100) &&
		((Imm & 0x0000ffffffffffffULL) == 0));
}

static inline uint8_t AArch64_AM_encodeAdvSIMDModImmType12(uint64_t Imm)
{
	uint8_t BitA = (Imm & 0x8000000000000000ULL) != 0;
	uint8_t BitB = (Imm & 0x0040000000000000ULL) != 0;
	uint8_t BitC = (Imm & 0x0020000000000000ULL) != 0;
	uint8_t BitD = (Imm & 0x0010000000000000ULL) != 0;
	uint8_t BitE = (Imm & 0x0008000000000000ULL) != 0;
	uint8_t BitF = (Imm & 0x0004000000000000ULL) != 0;
	uint8_t BitG = (Imm & 0x0002000000000000ULL) != 0;
	uint8_t BitH = (Imm & 0x0001000000000000ULL) != 0;

	uint8_t EncVal = BitA;
	EncVal <<= 1;
	EncVal |= BitB;
	EncVal <<= 1;
	EncVal |= BitC;
	EncVal <<= 1;
	EncVal |= BitD;
	EncVal <<= 1;
	EncVal |= BitE;
	EncVal <<= 1;
	EncVal |= BitF;
	EncVal <<= 1;
	EncVal |= BitG;
	EncVal <<= 1;
	EncVal |= BitH;

	return EncVal;
}

static inline uint64_t AArch64_AM_decodeAdvSIMDModImmType12(uint8_t Imm)
{
	uint64_t EncVal = 0;
	if (Imm & 0x80)
		EncVal |= 0x8000000000000000ULL;

	if (Imm & 0x40)
		EncVal |= 0x3fc0000000000000ULL;
	else
		EncVal |= 0x4000000000000000ULL;

	if (Imm & 0x20)
		EncVal |= 0x0020000000000000ULL;

	if (Imm & 0x10)
		EncVal |= 0x0010000000000000ULL;

	if (Imm & 0x08)
		EncVal |= 0x0008000000000000ULL;

	if (Imm & 0x04)
		EncVal |= 0x0004000000000000ULL;

	if (Imm & 0x02)
		EncVal |= 0x0002000000000000ULL;

	if (Imm & 0x01)
		EncVal |= 0x0001000000000000ULL;

	return (EncVal << 32) | EncVal;
}

/// Returns true if Imm is the concatenation of a repeating pattern of type T.
static inline bool AArch64_AM_isSVEMaskOfIdenticalElements8(int64_t Imm)
{
#define _VECSIZE (sizeof(int64_t)/sizeof(int8_t))
	unsigned int i;
	union {
		int64_t Whole;
		int8_t Parts[_VECSIZE];
	} Vec;

	Vec.Whole = Imm;

	for(i = 1; i < _VECSIZE; i++) {
		if (Vec.Parts[i] != Vec.Parts[0])
			return false;
	}
#undef _VECSIZE

	return true;
}

static inline bool AArch64_AM_isSVEMaskOfIdenticalElements16(int64_t Imm)
{
#define _VECSIZE (sizeof(int64_t)/sizeof(int16_t))
	unsigned int i;
	union {
		int64_t Whole;
		int16_t Parts[_VECSIZE];
	} Vec;

	Vec.Whole = Imm;

	for(i = 1; i < _VECSIZE; i++) {
		if (Vec.Parts[i] != Vec.Parts[0])
			return false;
	}
#undef _VECSIZE

	return true;
}

static inline bool AArch64_AM_isSVEMaskOfIdenticalElements32(int64_t Imm)
{
#define _VECSIZE (sizeof(int64_t)/sizeof(int32_t))
	unsigned int i;
	union {
		int64_t Whole;
		int32_t Parts[_VECSIZE];
	} Vec;

	Vec.Whole = Imm;

	for(i = 1; i < _VECSIZE; i++) {
		if (Vec.Parts[i] != Vec.Parts[0])
			return false;
	}
#undef _VECSIZE

	return true;
}

static inline bool AArch64_AM_isSVEMaskOfIdenticalElements64(int64_t Imm)
{
	return true;
}

static inline bool isSVECpyImm8(int64_t Imm)
{
	bool IsImm8 = (int8_t)Imm == Imm;

	return IsImm8 || (uint8_t)Imm == Imm;
}

static inline bool isSVECpyImm16(int64_t Imm)
{
	bool IsImm8 = (int8_t)Imm == Imm;
	bool IsImm16 = (int16_t)(Imm & ~0xff) == Imm;

	return IsImm8 || IsImm16 || (uint16_t)(Imm & ~0xff) == Imm;
}

static inline bool isSVECpyImm32(int64_t Imm)
{
	bool IsImm8 = (int8_t)Imm == Imm;
	bool IsImm16 = (int16_t)(Imm & ~0xff) == Imm;

	return IsImm8 || IsImm16;
}

static inline bool isSVECpyImm64(int64_t Imm)
{
	bool IsImm8 = (int8_t)Imm == Imm;
	bool IsImm16 = (int16_t)(Imm & ~0xff) == Imm;

	return IsImm8 || IsImm16;
}

/// Return true if Imm is valid for DUPM and has no single CPY/DUP equivalent.
static inline bool AArch64_AM_isSVEMoveMaskPreferredLogicalImmediate(int64_t Imm)
{
	union {
		int64_t D;
		int32_t S[2];
		int16_t H[4];
		int8_t B[8];
	} Vec = {Imm};

	if (isSVECpyImm64(Vec.D))
		return false;

	if (AArch64_AM_isSVEMaskOfIdenticalElements32(Imm) &&
			isSVECpyImm32(Vec.S[0]))
		return false;

	if (AArch64_AM_isSVEMaskOfIdenticalElements16(Imm) &&
			isSVECpyImm16(Vec.H[0]))
		return false;

	if (AArch64_AM_isSVEMaskOfIdenticalElements8(Imm) &&
			isSVECpyImm8(Vec.B[0]))
		return false;

	return isLogicalImmediate(Vec.D, 64);
}

inline static bool isAnyMOVZMovAlias(uint64_t Value, int RegWidth)
{
	int Shift;

	for (Shift = 0; Shift <= RegWidth - 16; Shift += 16)
		if ((Value & ~(0xffffULL << Shift)) == 0)
			return true;

	return false;
}

inline static bool isMOVZMovAlias(uint64_t Value, int Shift, int RegWidth)
{
	if (RegWidth == 32)
		Value &= 0xffffffffULL;

	// "lsl #0" takes precedence: in practice this only affects "#0, lsl #0".
	if (Value == 0 && Shift != 0)
		return false;

	return (Value & ~(0xffffULL << Shift)) == 0;
}

inline static bool AArch64_AM_isMOVNMovAlias(uint64_t Value, int Shift, int RegWidth)
{
	// MOVZ takes precedence over MOVN.
	if (isAnyMOVZMovAlias(Value, RegWidth))
		return false;

	Value = ~Value;
	if (RegWidth == 32)
		Value &= 0xffffffffULL;

	return isMOVZMovAlias(Value, Shift, RegWidth);
}

inline static bool AArch64_AM_isAnyMOVWMovAlias(uint64_t Value, int RegWidth)
{
	if (isAnyMOVZMovAlias(Value, RegWidth))
		return true;

	// It's not a MOVZ, but it might be a MOVN.
	Value = ~Value;
	if (RegWidth == 32)
		Value &= 0xffffffffULL;

	return isAnyMOVZMovAlias(Value, RegWidth);
}

#endif