| //===-- XtensaDisassembler.cpp - Disassembler for Xtensa ------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the XtensaDisassembler class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "MCTargetDesc/XtensaMCTargetDesc.h" |
| #include "TargetInfo/XtensaTargetInfo.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCDecoderOps.h" |
| #include "llvm/MC/MCDisassembler/MCDisassembler.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCRegisterInfo.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/MC/TargetRegistry.h" |
| #include "llvm/Support/Endian.h" |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "Xtensa-disassembler" |
| |
| using DecodeStatus = MCDisassembler::DecodeStatus; |
| |
| namespace { |
| |
| class XtensaDisassembler : public MCDisassembler { |
| bool IsLittleEndian; |
| |
| public: |
| XtensaDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx, bool isLE) |
| : MCDisassembler(STI, Ctx), IsLittleEndian(isLE) {} |
| |
| bool hasDensity() const { |
| return STI.hasFeature(Xtensa::FeatureDensity); |
| } |
| |
| DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, uint64_t Address, |
| raw_ostream &CStream) const override; |
| }; |
| } // end anonymous namespace |
| |
| static MCDisassembler *createXtensaDisassembler(const Target &T, |
| const MCSubtargetInfo &STI, |
| MCContext &Ctx) { |
| return new XtensaDisassembler(STI, Ctx, true); |
| } |
| |
| extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeXtensaDisassembler() { |
| TargetRegistry::RegisterMCDisassembler(getTheXtensaTarget(), |
| createXtensaDisassembler); |
| } |
| |
| static const unsigned ARDecoderTable[] = { |
| Xtensa::A0, Xtensa::SP, Xtensa::A2, Xtensa::A3, Xtensa::A4, Xtensa::A5, |
| Xtensa::A6, Xtensa::A7, Xtensa::A8, Xtensa::A9, Xtensa::A10, Xtensa::A11, |
| Xtensa::A12, Xtensa::A13, Xtensa::A14, Xtensa::A15}; |
| |
| static DecodeStatus DecodeARRegisterClass(MCInst &Inst, uint64_t RegNo, |
| uint64_t Address, |
| const void *Decoder) { |
| if (RegNo >= std::size(ARDecoderTable)) |
| return MCDisassembler::Fail; |
| |
| unsigned Reg = ARDecoderTable[RegNo]; |
| Inst.addOperand(MCOperand::createReg(Reg)); |
| return MCDisassembler::Success; |
| } |
| |
| static const unsigned SRDecoderTable[] = {Xtensa::SAR, 3}; |
| |
| static DecodeStatus DecodeSRRegisterClass(MCInst &Inst, uint64_t RegNo, |
| uint64_t Address, |
| const void *Decoder) { |
| if (RegNo > 255) |
| return MCDisassembler::Fail; |
| |
| for (unsigned i = 0; i < std::size(SRDecoderTable); i += 2) { |
| if (SRDecoderTable[i + 1] == RegNo) { |
| unsigned Reg = SRDecoderTable[i]; |
| Inst.addOperand(MCOperand::createReg(Reg)); |
| return MCDisassembler::Success; |
| } |
| } |
| |
| return MCDisassembler::Fail; |
| } |
| |
| static bool tryAddingSymbolicOperand(int64_t Value, bool isBranch, |
| uint64_t Address, uint64_t Offset, |
| uint64_t InstSize, MCInst &MI, |
| const void *Decoder) { |
| const MCDisassembler *Dis = static_cast<const MCDisassembler *>(Decoder); |
| return Dis->tryAddingSymbolicOperand(MI, Value, Address, isBranch, Offset, /*OpSize=*/0, |
| InstSize); |
| } |
| |
| static DecodeStatus decodeCallOperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<18>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(SignExtend64<20>(Imm << 2))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeJumpOperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<18>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(SignExtend64<18>(Imm))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeBranchOperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| switch (Inst.getOpcode()) { |
| case Xtensa::BEQZ: |
| case Xtensa::BGEZ: |
| case Xtensa::BLTZ: |
| case Xtensa::BNEZ: |
| assert(isUInt<12>(Imm) && "Invalid immediate"); |
| if (!tryAddingSymbolicOperand(SignExtend64<12>(Imm) + 4 + Address, true, |
| Address, 0, 3, Inst, Decoder)) |
| Inst.addOperand(MCOperand::createImm(SignExtend64<12>(Imm))); |
| break; |
| default: |
| assert(isUInt<8>(Imm) && "Invalid immediate"); |
| if (!tryAddingSymbolicOperand(SignExtend64<8>(Imm) + 4 + Address, true, |
| Address, 0, 3, Inst, Decoder)) |
| Inst.addOperand(MCOperand::createImm(SignExtend64<8>(Imm))); |
| } |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeL32ROperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| |
| assert(isUInt<16>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm( |
| SignExtend64<17>((Imm << 2) + 0x40000 + (Address & 0x3)))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeImm8Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<8>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(SignExtend64<8>(Imm))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeImm8_sh8Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, |
| const void *Decoder) { |
| assert(isUInt<8>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(SignExtend64<16>(Imm << 8))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeImm12Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<12>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(SignExtend64<12>(Imm))); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeUimm4Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<4>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(Imm)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeUimm5Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<5>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(Imm)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeImm1_16Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<4>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(Imm + 1)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeShimm1_31Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, |
| const void *Decoder) { |
| assert(isUInt<5>(Imm) && "Invalid immediate"); |
| Inst.addOperand(MCOperand::createImm(32 - Imm)); |
| return MCDisassembler::Success; |
| } |
| |
| static int64_t TableB4const[16] = {-1, 1, 2, 3, 4, 5, 6, 7, |
| 8, 10, 12, 16, 32, 64, 128, 256}; |
| static DecodeStatus decodeB4constOperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<4>(Imm) && "Invalid immediate"); |
| |
| Inst.addOperand(MCOperand::createImm(TableB4const[Imm])); |
| return MCDisassembler::Success; |
| } |
| |
| static int64_t TableB4constu[16] = {32768, 65536, 2, 3, 4, 5, 6, 7, |
| 8, 10, 12, 16, 32, 64, 128, 256}; |
| static DecodeStatus decodeB4constuOperand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, |
| const void *Decoder) { |
| assert(isUInt<4>(Imm) && "Invalid immediate"); |
| |
| Inst.addOperand(MCOperand::createImm(TableB4constu[Imm])); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeMem8Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<12>(Imm) && "Invalid immediate"); |
| DecodeARRegisterClass(Inst, Imm & 0xf, Address, Decoder); |
| Inst.addOperand(MCOperand::createImm((Imm >> 4) & 0xff)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeMem16Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<12>(Imm) && "Invalid immediate"); |
| DecodeARRegisterClass(Inst, Imm & 0xf, Address, Decoder); |
| Inst.addOperand(MCOperand::createImm((Imm >> 3) & 0x1fe)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus decodeMem32Operand(MCInst &Inst, uint64_t Imm, |
| int64_t Address, const void *Decoder) { |
| assert(isUInt<12>(Imm) && "Invalid immediate"); |
| DecodeARRegisterClass(Inst, Imm & 0xf, Address, Decoder); |
| Inst.addOperand(MCOperand::createImm((Imm >> 2) & 0x3fc)); |
| return MCDisassembler::Success; |
| } |
| |
| /// Read three bytes from the ArrayRef and return 24 bit data |
| static DecodeStatus readInstruction24(ArrayRef<uint8_t> Bytes, uint64_t Address, |
| uint64_t &Size, uint32_t &Insn, |
| bool IsLittleEndian) { |
| // We want to read exactly 3 Bytes of data. |
| if (Bytes.size() < 3) { |
| Size = 0; |
| return MCDisassembler::Fail; |
| } |
| |
| if (!IsLittleEndian) { |
| report_fatal_error("Big-endian mode currently is not supported!"); |
| } else { |
| Insn = (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0); |
| } |
| |
| Size = 3; |
| return MCDisassembler::Success; |
| } |
| |
| #include "XtensaGenDisassemblerTables.inc" |
| |
| DecodeStatus XtensaDisassembler::getInstruction(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, |
| uint64_t Address, |
| raw_ostream &CS) const { |
| uint32_t Insn; |
| DecodeStatus Result; |
| |
| Result = readInstruction24(Bytes, Address, Size, Insn, IsLittleEndian); |
| if (Result == MCDisassembler::Fail) |
| return MCDisassembler::Fail; |
| LLVM_DEBUG(dbgs() << "Trying Xtensa 24-bit instruction table :\n"); |
| Result = decodeInstruction(DecoderTable24, MI, Insn, Address, this, STI); |
| return Result; |
| } |
