| //===-- MSP430Disassembler.cpp - Disassembler for MSP430 ------------------===// |
| // |
| // 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 MSP430Disassembler class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "MSP430.h" |
| #include "MCTargetDesc/MSP430MCTargetDesc.h" |
| #include "TargetInfo/MSP430TargetInfo.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCDisassembler/MCDisassembler.h" |
| #include "llvm/MC/MCFixedLenDisassembler.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCRegisterInfo.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/Support/Endian.h" |
| #include "llvm/Support/TargetRegistry.h" |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "msp430-disassembler" |
| |
| typedef MCDisassembler::DecodeStatus DecodeStatus; |
| |
| namespace { |
| class MSP430Disassembler : public MCDisassembler { |
| DecodeStatus getInstructionI(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, uint64_t Address, |
| raw_ostream &CStream) const; |
| |
| DecodeStatus getInstructionII(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, uint64_t Address, |
| raw_ostream &CStream) const; |
| |
| DecodeStatus getInstructionCJ(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, uint64_t Address, |
| raw_ostream &CStream) const; |
| |
| public: |
| MSP430Disassembler(const MCSubtargetInfo &STI, MCContext &Ctx) |
| : MCDisassembler(STI, Ctx) {} |
| |
| DecodeStatus getInstruction(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, uint64_t Address, |
| raw_ostream &CStream) const override; |
| }; |
| } // end anonymous namespace |
| |
| static MCDisassembler *createMSP430Disassembler(const Target &T, |
| const MCSubtargetInfo &STI, |
| MCContext &Ctx) { |
| return new MSP430Disassembler(STI, Ctx); |
| } |
| |
| extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMSP430Disassembler() { |
| TargetRegistry::RegisterMCDisassembler(getTheMSP430Target(), |
| createMSP430Disassembler); |
| } |
| |
| static const unsigned GR8DecoderTable[] = { |
| MSP430::PCB, MSP430::SPB, MSP430::SRB, MSP430::CGB, |
| MSP430::FPB, MSP430::R5B, MSP430::R6B, MSP430::R7B, |
| MSP430::R8B, MSP430::R9B, MSP430::R10B, MSP430::R11B, |
| MSP430::R12B, MSP430::R13B, MSP430::R14B, MSP430::R15B |
| }; |
| |
| static DecodeStatus DecodeGR8RegisterClass(MCInst &MI, uint64_t RegNo, |
| uint64_t Address, |
| const void *Decoder) { |
| if (RegNo > 15) |
| return MCDisassembler::Fail; |
| |
| unsigned Reg = GR8DecoderTable[RegNo]; |
| MI.addOperand(MCOperand::createReg(Reg)); |
| return MCDisassembler::Success; |
| } |
| |
| static const unsigned GR16DecoderTable[] = { |
| MSP430::PC, MSP430::SP, MSP430::SR, MSP430::CG, |
| MSP430::FP, MSP430::R5, MSP430::R6, MSP430::R7, |
| MSP430::R8, MSP430::R9, MSP430::R10, MSP430::R11, |
| MSP430::R12, MSP430::R13, MSP430::R14, MSP430::R15 |
| }; |
| |
| static DecodeStatus DecodeGR16RegisterClass(MCInst &MI, uint64_t RegNo, |
| uint64_t Address, |
| const void *Decoder) { |
| if (RegNo > 15) |
| return MCDisassembler::Fail; |
| |
| unsigned Reg = GR16DecoderTable[RegNo]; |
| MI.addOperand(MCOperand::createReg(Reg)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus DecodeCGImm(MCInst &MI, uint64_t Bits, uint64_t Address, |
| const void *Decoder); |
| |
| static DecodeStatus DecodeMemOperand(MCInst &MI, uint64_t Bits, |
| uint64_t Address, |
| const void *Decoder); |
| |
| #include "MSP430GenDisassemblerTables.inc" |
| |
| static DecodeStatus DecodeCGImm(MCInst &MI, uint64_t Bits, uint64_t Address, |
| const void *Decoder) { |
| int64_t Imm; |
| switch (Bits) { |
| default: |
| llvm_unreachable("Invalid immediate value"); |
| case 0x22: Imm = 4; break; |
| case 0x32: Imm = 8; break; |
| case 0x03: Imm = 0; break; |
| case 0x13: Imm = 1; break; |
| case 0x23: Imm = 2; break; |
| case 0x33: Imm = -1; break; |
| } |
| MI.addOperand(MCOperand::createImm(Imm)); |
| return MCDisassembler::Success; |
| } |
| |
| static DecodeStatus DecodeMemOperand(MCInst &MI, uint64_t Bits, |
| uint64_t Address, |
| const void *Decoder) { |
| unsigned Reg = Bits & 15; |
| unsigned Imm = Bits >> 4; |
| |
| if (DecodeGR16RegisterClass(MI, Reg, Address, Decoder) != |
| MCDisassembler::Success) |
| return MCDisassembler::Fail; |
| |
| MI.addOperand(MCOperand::createImm((int16_t)Imm)); |
| return MCDisassembler::Success; |
| } |
| |
| enum AddrMode { |
| amInvalid = 0, |
| amRegister, |
| amIndexed, |
| amIndirect, |
| amIndirectPost, |
| amSymbolic, |
| amImmediate, |
| amAbsolute, |
| amConstant |
| }; |
| |
| static AddrMode DecodeSrcAddrMode(unsigned Rs, unsigned As) { |
| switch (Rs) { |
| case 0: |
| if (As == 1) return amSymbolic; |
| if (As == 2) return amInvalid; |
| if (As == 3) return amImmediate; |
| break; |
| case 2: |
| if (As == 1) return amAbsolute; |
| if (As == 2) return amConstant; |
| if (As == 3) return amConstant; |
| break; |
| case 3: |
| return amConstant; |
| default: |
| break; |
| } |
| switch (As) { |
| case 0: return amRegister; |
| case 1: return amIndexed; |
| case 2: return amIndirect; |
| case 3: return amIndirectPost; |
| default: |
| llvm_unreachable("As out of range"); |
| } |
| } |
| |
| static AddrMode DecodeSrcAddrModeI(unsigned Insn) { |
| unsigned Rs = fieldFromInstruction(Insn, 8, 4); |
| unsigned As = fieldFromInstruction(Insn, 4, 2); |
| return DecodeSrcAddrMode(Rs, As); |
| } |
| |
| static AddrMode DecodeSrcAddrModeII(unsigned Insn) { |
| unsigned Rs = fieldFromInstruction(Insn, 0, 4); |
| unsigned As = fieldFromInstruction(Insn, 4, 2); |
| return DecodeSrcAddrMode(Rs, As); |
| } |
| |
| static AddrMode DecodeDstAddrMode(unsigned Insn) { |
| unsigned Rd = fieldFromInstruction(Insn, 0, 4); |
| unsigned Ad = fieldFromInstruction(Insn, 7, 1); |
| switch (Rd) { |
| case 0: return Ad ? amSymbolic : amRegister; |
| case 2: return Ad ? amAbsolute : amRegister; |
| default: |
| break; |
| } |
| return Ad ? amIndexed : amRegister; |
| } |
| |
| static const uint8_t *getDecoderTable(AddrMode SrcAM, unsigned Words) { |
| assert(0 < Words && Words < 4 && "Incorrect number of words"); |
| switch (SrcAM) { |
| default: |
| llvm_unreachable("Invalid addressing mode"); |
| case amRegister: |
| assert(Words < 3 && "Incorrect number of words"); |
| return Words == 2 ? DecoderTableAlpha32 : DecoderTableAlpha16; |
| case amConstant: |
| assert(Words < 3 && "Incorrect number of words"); |
| return Words == 2 ? DecoderTableBeta32 : DecoderTableBeta16; |
| case amIndexed: |
| case amSymbolic: |
| case amImmediate: |
| case amAbsolute: |
| assert(Words > 1 && "Incorrect number of words"); |
| return Words == 2 ? DecoderTableGamma32 : DecoderTableGamma48; |
| case amIndirect: |
| case amIndirectPost: |
| assert(Words < 3 && "Incorrect number of words"); |
| return Words == 2 ? DecoderTableDelta32 : DecoderTableDelta16; |
| } |
| } |
| |
| DecodeStatus MSP430Disassembler::getInstructionI(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, |
| uint64_t Address, |
| raw_ostream &CStream) const { |
| uint64_t Insn = support::endian::read16le(Bytes.data()); |
| AddrMode SrcAM = DecodeSrcAddrModeI(Insn); |
| AddrMode DstAM = DecodeDstAddrMode(Insn); |
| if (SrcAM == amInvalid || DstAM == amInvalid) { |
| Size = 2; // skip one word and let disassembler to try further |
| return MCDisassembler::Fail; |
| } |
| |
| unsigned Words = 1; |
| switch (SrcAM) { |
| case amIndexed: |
| case amSymbolic: |
| case amImmediate: |
| case amAbsolute: |
| if (Bytes.size() < (Words + 1) * 2) { |
| Size = 2; |
| return DecodeStatus::Fail; |
| } |
| Insn |= (uint64_t)support::endian::read16le(Bytes.data() + 2) << 16; |
| ++Words; |
| break; |
| default: |
| break; |
| } |
| switch (DstAM) { |
| case amIndexed: |
| case amSymbolic: |
| case amAbsolute: |
| if (Bytes.size() < (Words + 1) * 2) { |
| Size = 2; |
| return DecodeStatus::Fail; |
| } |
| Insn |= (uint64_t)support::endian::read16le(Bytes.data() + Words * 2) |
| << (Words * 16); |
| ++Words; |
| break; |
| default: |
| break; |
| } |
| |
| DecodeStatus Result = decodeInstruction(getDecoderTable(SrcAM, Words), MI, |
| Insn, Address, this, STI); |
| if (Result != MCDisassembler::Fail) { |
| Size = Words * 2; |
| return Result; |
| } |
| |
| Size = 2; |
| return DecodeStatus::Fail; |
| } |
| |
| DecodeStatus MSP430Disassembler::getInstructionII(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, |
| uint64_t Address, |
| raw_ostream &CStream) const { |
| uint64_t Insn = support::endian::read16le(Bytes.data()); |
| AddrMode SrcAM = DecodeSrcAddrModeII(Insn); |
| if (SrcAM == amInvalid) { |
| Size = 2; // skip one word and let disassembler to try further |
| return MCDisassembler::Fail; |
| } |
| |
| unsigned Words = 1; |
| switch (SrcAM) { |
| case amIndexed: |
| case amSymbolic: |
| case amImmediate: |
| case amAbsolute: |
| if (Bytes.size() < (Words + 1) * 2) { |
| Size = 2; |
| return DecodeStatus::Fail; |
| } |
| Insn |= (uint64_t)support::endian::read16le(Bytes.data() + 2) << 16; |
| ++Words; |
| break; |
| default: |
| break; |
| } |
| |
| const uint8_t *DecoderTable = Words == 2 ? DecoderTable32 : DecoderTable16; |
| DecodeStatus Result = decodeInstruction(DecoderTable, MI, Insn, Address, |
| this, STI); |
| if (Result != MCDisassembler::Fail) { |
| Size = Words * 2; |
| return Result; |
| } |
| |
| Size = 2; |
| return DecodeStatus::Fail; |
| } |
| |
| static MSP430CC::CondCodes getCondCode(unsigned Cond) { |
| switch (Cond) { |
| case 0: return MSP430CC::COND_NE; |
| case 1: return MSP430CC::COND_E; |
| case 2: return MSP430CC::COND_LO; |
| case 3: return MSP430CC::COND_HS; |
| case 4: return MSP430CC::COND_N; |
| case 5: return MSP430CC::COND_GE; |
| case 6: return MSP430CC::COND_L; |
| case 7: return MSP430CC::COND_NONE; |
| default: |
| llvm_unreachable("Cond out of range"); |
| } |
| } |
| |
| DecodeStatus MSP430Disassembler::getInstructionCJ(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, |
| uint64_t Address, |
| raw_ostream &CStream) const { |
| uint64_t Insn = support::endian::read16le(Bytes.data()); |
| unsigned Cond = fieldFromInstruction(Insn, 10, 3); |
| unsigned Offset = fieldFromInstruction(Insn, 0, 10); |
| |
| MI.addOperand(MCOperand::createImm(SignExtend32(Offset, 10))); |
| |
| if (Cond == 7) |
| MI.setOpcode(MSP430::JMP); |
| else { |
| MI.setOpcode(MSP430::JCC); |
| MI.addOperand(MCOperand::createImm(getCondCode(Cond))); |
| } |
| |
| Size = 2; |
| return DecodeStatus::Success; |
| } |
| |
| DecodeStatus MSP430Disassembler::getInstruction(MCInst &MI, uint64_t &Size, |
| ArrayRef<uint8_t> Bytes, |
| uint64_t Address, |
| raw_ostream &CStream) const { |
| if (Bytes.size() < 2) { |
| Size = 0; |
| return MCDisassembler::Fail; |
| } |
| |
| uint64_t Insn = support::endian::read16le(Bytes.data()); |
| unsigned Opc = fieldFromInstruction(Insn, 13, 3); |
| switch (Opc) { |
| case 0: |
| return getInstructionII(MI, Size, Bytes, Address, CStream); |
| case 1: |
| return getInstructionCJ(MI, Size, Bytes, Address, CStream); |
| default: |
| return getInstructionI(MI, Size, Bytes, Address, CStream); |
| } |
| } |
