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Diffstat (limited to 'lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp')
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1 files changed, 803 insertions, 0 deletions
diff --git a/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp new file mode 100644 index 000000000000..12c1b8f4c81a --- /dev/null +++ b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp @@ -0,0 +1,803 @@ +//===- AArch64Disassembler.cpp - Disassembler for AArch64 ISA -------------===// +// +// 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 functions necessary to decode AArch64 instruction +// bitpatterns into MCInsts (with the help of TableGenerated information from +// the instruction definitions). +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "arm-disassembler" + +#include "AArch64.h" +#include "AArch64RegisterInfo.h" +#include "AArch64Subtarget.h" +#include "Utils/AArch64BaseInfo.h" +#include "llvm/MC/MCInst.h" +#include "llvm/MC/MCInstrDesc.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCDisassembler.h" +#include "llvm/MC/MCFixedLenDisassembler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/MemoryObject.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/TargetRegistry.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; + +typedef MCDisassembler::DecodeStatus DecodeStatus; + +namespace { +/// AArch64 disassembler for all AArch64 platforms. +class AArch64Disassembler : public MCDisassembler { + const MCRegisterInfo *RegInfo; +public: + /// Initializes the disassembler. + /// + AArch64Disassembler(const MCSubtargetInfo &STI, const MCRegisterInfo *Info) + : MCDisassembler(STI), RegInfo(Info) { + } + + ~AArch64Disassembler() { + } + + /// See MCDisassembler. + DecodeStatus getInstruction(MCInst &instr, + uint64_t &size, + const MemoryObject ®ion, + uint64_t address, + raw_ostream &vStream, + raw_ostream &cStream) const; + + const MCRegisterInfo *getRegInfo() const { return RegInfo; } +}; + +} + +// Forward-declarations used in the auto-generated files. +static DecodeStatus DecodeGPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus +DecodeGPR64xspRegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); + +static DecodeStatus DecodeGPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus +DecodeGPR32wspRegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); + +static DecodeStatus DecodeFPR8RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus DecodeFPR16RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus DecodeFPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus DecodeFPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder); +static DecodeStatus DecodeFPR128RegisterClass(llvm::MCInst &Inst, + unsigned RegNo, uint64_t Address, + const void *Decoder); +static DecodeStatus DecodeVPR128RegisterClass(llvm::MCInst &Inst, + unsigned RegNo, uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeAddrRegExtendOperand(llvm::MCInst &Inst, + unsigned OptionHiS, + uint64_t Address, + const void *Decoder); + + +static DecodeStatus DecodeBitfield32ImmOperand(llvm::MCInst &Inst, + unsigned Imm6Bits, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeCVT32FixedPosOperand(llvm::MCInst &Inst, + unsigned Imm6Bits, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeFPZeroOperand(llvm::MCInst &Inst, + unsigned RmBits, + uint64_t Address, + const void *Decoder); + +template<int RegWidth> +static DecodeStatus DecodeMoveWideImmOperand(llvm::MCInst &Inst, + unsigned FullImm, + uint64_t Address, + const void *Decoder); + +template<int RegWidth> +static DecodeStatus DecodeLogicalImmOperand(llvm::MCInst &Inst, + unsigned Bits, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeRegExtendOperand(llvm::MCInst &Inst, + unsigned ShiftAmount, + uint64_t Address, + const void *Decoder); + +static DecodeStatus Decode32BitShiftOperand(llvm::MCInst &Inst, + unsigned ShiftAmount, + uint64_t Address, + const void *Decoder); +static DecodeStatus DecodeBitfieldInstruction(llvm::MCInst &Inst, unsigned Insn, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeFMOVLaneInstruction(llvm::MCInst &Inst, unsigned Insn, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeLDSTPairInstruction(llvm::MCInst &Inst, + unsigned Insn, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeLoadPairExclusiveInstruction(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder); + +template<typename SomeNamedImmMapper> +static DecodeStatus DecodeNamedImmOperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder); + +static DecodeStatus +DecodeSysRegOperand(const A64SysReg::SysRegMapper &InstMapper, + llvm::MCInst &Inst, unsigned Val, + uint64_t Address, const void *Decoder); + +static DecodeStatus DecodeMRSOperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder); + +static DecodeStatus DecodeMSROperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder); + + +static DecodeStatus DecodeSingleIndexedInstruction(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder); + + +static bool Check(DecodeStatus &Out, DecodeStatus In); + +#include "AArch64GenDisassemblerTables.inc" +#include "AArch64GenInstrInfo.inc" + +static bool Check(DecodeStatus &Out, DecodeStatus In) { + switch (In) { + case MCDisassembler::Success: + // Out stays the same. + return true; + case MCDisassembler::SoftFail: + Out = In; + return true; + case MCDisassembler::Fail: + Out = In; + return false; + } + llvm_unreachable("Invalid DecodeStatus!"); +} + +DecodeStatus AArch64Disassembler::getInstruction(MCInst &MI, uint64_t &Size, + const MemoryObject &Region, + uint64_t Address, + raw_ostream &os, + raw_ostream &cs) const { + CommentStream = &cs; + + uint8_t bytes[4]; + + // We want to read exactly 4 bytes of data. + if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) { + Size = 0; + return MCDisassembler::Fail; + } + + // Encoded as a small-endian 32-bit word in the stream. + uint32_t insn = (bytes[3] << 24) | + (bytes[2] << 16) | + (bytes[1] << 8) | + (bytes[0] << 0); + + // Calling the auto-generated decoder function. + DecodeStatus result = decodeInstruction(DecoderTableA6432, MI, insn, Address, + this, STI); + if (result != MCDisassembler::Fail) { + Size = 4; + return result; + } + + MI.clear(); + Size = 0; + return MCDisassembler::Fail; +} + +static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) { + const AArch64Disassembler *Dis = static_cast<const AArch64Disassembler*>(D); + return Dis->getRegInfo()->getRegClass(RC).getRegister(RegNo); +} + +static DecodeStatus DecodeGPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::GPR64RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeGPR64xspRegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::GPR64xspRegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeGPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, + const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::GPR32RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeGPR32wspRegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::GPR32wspRegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeFPR8RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::FPR8RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeFPR16RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::FPR16RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + + +static DecodeStatus +DecodeFPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::FPR32RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeFPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::FPR64RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + + +static DecodeStatus +DecodeFPR128RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::FPR128RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus +DecodeVPR128RegisterClass(llvm::MCInst &Inst, unsigned RegNo, + uint64_t Address, const void *Decoder) { + if (RegNo > 31) + return MCDisassembler::Fail; + + uint16_t Register = getReg(Decoder, AArch64::VPR128RegClassID, RegNo); + Inst.addOperand(MCOperand::CreateReg(Register)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeAddrRegExtendOperand(llvm::MCInst &Inst, + unsigned OptionHiS, + uint64_t Address, + const void *Decoder) { + // Option{1} must be 1. OptionHiS is made up of {Option{2}, Option{1}, + // S}. Hence we want to check bit 1. + if (!(OptionHiS & 2)) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(OptionHiS)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeBitfield32ImmOperand(llvm::MCInst &Inst, + unsigned Imm6Bits, + uint64_t Address, + const void *Decoder) { + // In the 32-bit variant, bit 6 must be zero. I.e. the immediate must be + // between 0 and 31. + if (Imm6Bits > 31) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(Imm6Bits)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeCVT32FixedPosOperand(llvm::MCInst &Inst, + unsigned Imm6Bits, + uint64_t Address, + const void *Decoder) { + // 1 <= Imm <= 32. Encoded as 64 - Imm so: 63 >= Encoded >= 32. + if (Imm6Bits < 32) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(Imm6Bits)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeFPZeroOperand(llvm::MCInst &Inst, + unsigned RmBits, + uint64_t Address, + const void *Decoder) { + // Any bits are valid in the instruction (they're architecturally ignored), + // but a code generator should insert 0. + Inst.addOperand(MCOperand::CreateImm(0)); + return MCDisassembler::Success; +} + + + +template<int RegWidth> +static DecodeStatus DecodeMoveWideImmOperand(llvm::MCInst &Inst, + unsigned FullImm, + uint64_t Address, + const void *Decoder) { + unsigned Imm16 = FullImm & 0xffff; + unsigned Shift = FullImm >> 16; + + if (RegWidth == 32 && Shift > 1) return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(Imm16)); + Inst.addOperand(MCOperand::CreateImm(Shift)); + return MCDisassembler::Success; +} + +template<int RegWidth> +static DecodeStatus DecodeLogicalImmOperand(llvm::MCInst &Inst, + unsigned Bits, + uint64_t Address, + const void *Decoder) { + uint64_t Imm; + if (!A64Imms::isLogicalImmBits(RegWidth, Bits, Imm)) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(Bits)); + return MCDisassembler::Success; +} + + +static DecodeStatus DecodeRegExtendOperand(llvm::MCInst &Inst, + unsigned ShiftAmount, + uint64_t Address, + const void *Decoder) { + // Only values 0-4 are valid for this 3-bit field + if (ShiftAmount > 4) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(ShiftAmount)); + return MCDisassembler::Success; +} + +static DecodeStatus Decode32BitShiftOperand(llvm::MCInst &Inst, + unsigned ShiftAmount, + uint64_t Address, + const void *Decoder) { + // Only values below 32 are valid for a 32-bit register + if (ShiftAmount > 31) + return MCDisassembler::Fail; + + Inst.addOperand(MCOperand::CreateImm(ShiftAmount)); + return MCDisassembler::Success; +} + +static DecodeStatus DecodeBitfieldInstruction(llvm::MCInst &Inst, unsigned Insn, + uint64_t Address, + const void *Decoder) { + unsigned Rd = fieldFromInstruction(Insn, 0, 5); + unsigned Rn = fieldFromInstruction(Insn, 5, 5); + unsigned ImmS = fieldFromInstruction(Insn, 10, 6); + unsigned ImmR = fieldFromInstruction(Insn, 16, 6); + unsigned SF = fieldFromInstruction(Insn, 31, 1); + + // Undef for 0b11 just in case it occurs. Don't want the compiler to optimise + // out assertions that it thinks should never be hit. + enum OpcTypes { SBFM = 0, BFM, UBFM, Undef } Opc; + Opc = (OpcTypes)fieldFromInstruction(Insn, 29, 2); + + if (!SF) { + // ImmR and ImmS must be between 0 and 31 for 32-bit instructions. + if (ImmR > 31 || ImmS > 31) + return MCDisassembler::Fail; + } + + if (SF) { + DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder); + // BFM MCInsts use Rd as a source too. + if (Opc == BFM) DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder); + DecodeGPR64RegisterClass(Inst, Rn, Address, Decoder); + } else { + DecodeGPR32RegisterClass(Inst, Rd, Address, Decoder); + // BFM MCInsts use Rd as a source too. + if (Opc == BFM) DecodeGPR32RegisterClass(Inst, Rd, Address, Decoder); + DecodeGPR32RegisterClass(Inst, Rn, Address, Decoder); + } + + // ASR and LSR have more specific patterns so they won't get here: + assert(!(ImmS == 31 && !SF && Opc != BFM) + && "shift should have used auto decode"); + assert(!(ImmS == 63 && SF && Opc != BFM) + && "shift should have used auto decode"); + + // Extension instructions similarly: + if (Opc == SBFM && ImmR == 0) { + assert((ImmS != 7 && ImmS != 15) && "extension got here"); + assert((ImmS != 31 || SF == 0) && "extension got here"); + } else if (Opc == UBFM && ImmR == 0) { + assert((SF != 0 || (ImmS != 7 && ImmS != 15)) && "extension got here"); + } + + if (Opc == UBFM) { + // It might be a LSL instruction, which actually takes the shift amount + // itself as an MCInst operand. + if (SF && (ImmS + 1) % 64 == ImmR) { + Inst.setOpcode(AArch64::LSLxxi); + Inst.addOperand(MCOperand::CreateImm(63 - ImmS)); + return MCDisassembler::Success; + } else if (!SF && (ImmS + 1) % 32 == ImmR) { + Inst.setOpcode(AArch64::LSLwwi); + Inst.addOperand(MCOperand::CreateImm(31 - ImmS)); + return MCDisassembler::Success; + } + } + + // Otherwise it's definitely either an extract or an insert depending on which + // of ImmR or ImmS is larger. + unsigned ExtractOp, InsertOp; + switch (Opc) { + default: llvm_unreachable("unexpected instruction trying to decode bitfield"); + case SBFM: + ExtractOp = SF ? AArch64::SBFXxxii : AArch64::SBFXwwii; + InsertOp = SF ? AArch64::SBFIZxxii : AArch64::SBFIZwwii; + break; + case BFM: + ExtractOp = SF ? AArch64::BFXILxxii : AArch64::BFXILwwii; + InsertOp = SF ? AArch64::BFIxxii : AArch64::BFIwwii; + break; + case UBFM: + ExtractOp = SF ? AArch64::UBFXxxii : AArch64::UBFXwwii; + InsertOp = SF ? AArch64::UBFIZxxii : AArch64::UBFIZwwii; + break; + } + + // Otherwise it's a boring insert or extract + Inst.addOperand(MCOperand::CreateImm(ImmR)); + Inst.addOperand(MCOperand::CreateImm(ImmS)); + + + if (ImmS < ImmR) + Inst.setOpcode(InsertOp); + else + Inst.setOpcode(ExtractOp); + + return MCDisassembler::Success; +} + +static DecodeStatus DecodeFMOVLaneInstruction(llvm::MCInst &Inst, unsigned Insn, + uint64_t Address, + const void *Decoder) { + // This decoder exists to add the dummy Lane operand to the MCInst, which must + // be 1 in assembly but has no other real manifestation. + unsigned Rd = fieldFromInstruction(Insn, 0, 5); + unsigned Rn = fieldFromInstruction(Insn, 5, 5); + unsigned IsToVec = fieldFromInstruction(Insn, 16, 1); + + if (IsToVec) { + DecodeVPR128RegisterClass(Inst, Rd, Address, Decoder); + DecodeGPR64RegisterClass(Inst, Rn, Address, Decoder); + } else { + DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder); + DecodeVPR128RegisterClass(Inst, Rn, Address, Decoder); + } + + // Add the lane + Inst.addOperand(MCOperand::CreateImm(1)); + + return MCDisassembler::Success; +} + + +static DecodeStatus DecodeLDSTPairInstruction(llvm::MCInst &Inst, + unsigned Insn, + uint64_t Address, + const void *Decoder) { + DecodeStatus Result = MCDisassembler::Success; + unsigned Rt = fieldFromInstruction(Insn, 0, 5); + unsigned Rn = fieldFromInstruction(Insn, 5, 5); + unsigned Rt2 = fieldFromInstruction(Insn, 10, 5); + unsigned SImm7 = fieldFromInstruction(Insn, 15, 7); + unsigned L = fieldFromInstruction(Insn, 22, 1); + unsigned V = fieldFromInstruction(Insn, 26, 1); + unsigned Opc = fieldFromInstruction(Insn, 30, 2); + + // Not an official name, but it turns out that bit 23 distinguishes indexed + // from non-indexed operations. + unsigned Indexed = fieldFromInstruction(Insn, 23, 1); + + if (Indexed && L == 0) { + // The MCInst for an indexed store has an out operand and 4 ins: + // Rn_wb, Rt, Rt2, Rn, Imm + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + } + + // You shouldn't load to the same register twice in an instruction... + if (L && Rt == Rt2) + Result = MCDisassembler::SoftFail; + + // ... or do any operation that writes-back to a transfer register. But note + // that "stp xzr, xzr, [sp], #4" is fine because xzr and sp are different. + if (Indexed && V == 0 && Rn != 31 && (Rt == Rn || Rt2 == Rn)) + Result = MCDisassembler::SoftFail; + + // Exactly how we decode the MCInst's registers depends on the Opc and V + // fields of the instruction. These also obviously determine the size of the + // operation so we can fill in that information while we're at it. + if (V) { + // The instruction operates on the FP/SIMD registers + switch (Opc) { + default: return MCDisassembler::Fail; + case 0: + DecodeFPR32RegisterClass(Inst, Rt, Address, Decoder); + DecodeFPR32RegisterClass(Inst, Rt2, Address, Decoder); + break; + case 1: + DecodeFPR64RegisterClass(Inst, Rt, Address, Decoder); + DecodeFPR64RegisterClass(Inst, Rt2, Address, Decoder); + break; + case 2: + DecodeFPR128RegisterClass(Inst, Rt, Address, Decoder); + DecodeFPR128RegisterClass(Inst, Rt2, Address, Decoder); + break; + } + } else { + switch (Opc) { + default: return MCDisassembler::Fail; + case 0: + DecodeGPR32RegisterClass(Inst, Rt, Address, Decoder); + DecodeGPR32RegisterClass(Inst, Rt2, Address, Decoder); + break; + case 1: + assert(L && "unexpected \"store signed\" attempt"); + DecodeGPR64RegisterClass(Inst, Rt, Address, Decoder); + DecodeGPR64RegisterClass(Inst, Rt2, Address, Decoder); + break; + case 2: + DecodeGPR64RegisterClass(Inst, Rt, Address, Decoder); + DecodeGPR64RegisterClass(Inst, Rt2, Address, Decoder); + break; + } + } + + if (Indexed && L == 1) { + // The MCInst for an indexed load has 3 out operands and an 3 ins: + // Rt, Rt2, Rn_wb, Rt2, Rn, Imm + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + } + + + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + Inst.addOperand(MCOperand::CreateImm(SImm7)); + + return Result; +} + +static DecodeStatus DecodeLoadPairExclusiveInstruction(llvm::MCInst &Inst, + uint32_t Val, + uint64_t Address, + const void *Decoder) { + unsigned Rt = fieldFromInstruction(Val, 0, 5); + unsigned Rn = fieldFromInstruction(Val, 5, 5); + unsigned Rt2 = fieldFromInstruction(Val, 10, 5); + unsigned MemSize = fieldFromInstruction(Val, 30, 2); + + DecodeStatus S = MCDisassembler::Success; + if (Rt == Rt2) S = MCDisassembler::SoftFail; + + switch (MemSize) { + case 2: + if (!Check(S, DecodeGPR32RegisterClass(Inst, Rt, Address, Decoder))) + return MCDisassembler::Fail; + if (!Check(S, DecodeGPR32RegisterClass(Inst, Rt2, Address, Decoder))) + return MCDisassembler::Fail; + break; + case 3: + if (!Check(S, DecodeGPR64RegisterClass(Inst, Rt, Address, Decoder))) + return MCDisassembler::Fail; + if (!Check(S, DecodeGPR64RegisterClass(Inst, Rt2, Address, Decoder))) + return MCDisassembler::Fail; + break; + default: + llvm_unreachable("Invalid MemSize in DecodeLoadPairExclusiveInstruction"); + } + + if (!Check(S, DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder))) + return MCDisassembler::Fail; + + return S; +} + +template<typename SomeNamedImmMapper> +static DecodeStatus DecodeNamedImmOperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder) { + SomeNamedImmMapper Mapper; + bool ValidNamed; + Mapper.toString(Val, ValidNamed); + if (ValidNamed || Mapper.validImm(Val)) { + Inst.addOperand(MCOperand::CreateImm(Val)); + return MCDisassembler::Success; + } + + return MCDisassembler::Fail; +} + +static DecodeStatus DecodeSysRegOperand(const A64SysReg::SysRegMapper &Mapper, + llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder) { + bool ValidNamed; + Mapper.toString(Val, ValidNamed); + + Inst.addOperand(MCOperand::CreateImm(Val)); + + return ValidNamed ? MCDisassembler::Success : MCDisassembler::Fail; +} + +static DecodeStatus DecodeMRSOperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder) { + return DecodeSysRegOperand(A64SysReg::MRSMapper(), Inst, Val, Address, + Decoder); +} + +static DecodeStatus DecodeMSROperand(llvm::MCInst &Inst, + unsigned Val, + uint64_t Address, + const void *Decoder) { + return DecodeSysRegOperand(A64SysReg::MSRMapper(), Inst, Val, Address, + Decoder); +} + +static DecodeStatus DecodeSingleIndexedInstruction(llvm::MCInst &Inst, + unsigned Insn, + uint64_t Address, + const void *Decoder) { + unsigned Rt = fieldFromInstruction(Insn, 0, 5); + unsigned Rn = fieldFromInstruction(Insn, 5, 5); + unsigned Imm9 = fieldFromInstruction(Insn, 12, 9); + + unsigned Opc = fieldFromInstruction(Insn, 22, 2); + unsigned V = fieldFromInstruction(Insn, 26, 1); + unsigned Size = fieldFromInstruction(Insn, 30, 2); + + if (Opc == 0 || (V == 1 && Opc == 2)) { + // It's a store, the MCInst gets: Rn_wb, Rt, Rn, Imm + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + } + + if (V == 0 && (Opc == 2 || Size == 3)) { + DecodeGPR64RegisterClass(Inst, Rt, Address, Decoder); + } else if (V == 0) { + DecodeGPR32RegisterClass(Inst, Rt, Address, Decoder); + } else if (V == 1 && (Opc & 2)) { + DecodeFPR128RegisterClass(Inst, Rt, Address, Decoder); + } else { + switch (Size) { + case 0: + DecodeFPR8RegisterClass(Inst, Rt, Address, Decoder); + break; + case 1: + DecodeFPR16RegisterClass(Inst, Rt, Address, Decoder); + break; + case 2: + DecodeFPR32RegisterClass(Inst, Rt, Address, Decoder); + break; + case 3: + DecodeFPR64RegisterClass(Inst, Rt, Address, Decoder); + break; + } + } + + if (Opc != 0 && (V != 1 || Opc != 2)) { + // It's a load, the MCInst gets: Rt, Rn_wb, Rn, Imm + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + } + + DecodeGPR64xspRegisterClass(Inst, Rn, Address, Decoder); + + Inst.addOperand(MCOperand::CreateImm(Imm9)); + + // N.b. The official documentation says undpredictable if Rt == Rn, but this + // takes place at the architectural rather than encoding level: + // + // "STR xzr, [sp], #4" is perfectly valid. + if (V == 0 && Rt == Rn && Rn != 31) + return MCDisassembler::SoftFail; + else + return MCDisassembler::Success; +} + +static MCDisassembler *createAArch64Disassembler(const Target &T, + const MCSubtargetInfo &STI) { + return new AArch64Disassembler(STI, T.createMCRegInfo("")); +} + +extern "C" void LLVMInitializeAArch64Disassembler() { + TargetRegistry::RegisterMCDisassembler(TheAArch64Target, + createAArch64Disassembler); +} + + |