//===-- M68kDisassembler.cpp - Disassembler for M68k ------------*- C++ -*-===//
//
// 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 is part of the M68k Disassembler.
//
//===----------------------------------------------------------------------===//
#include "M68k.h"
#include "M68kRegisterInfo.h"
#include "M68kSubtarget.h"
#include "MCTargetDesc/M68kMCCodeEmitter.h"
#include "MCTargetDesc/M68kMCTargetDesc.h"
#include "TargetInfo/M68kTargetInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDisassembler/MCDisassembler.h"
#include "llvm/MC/MCDecoderOps.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
#define DEBUG_TYPE "m68k-disassembler"
typedef MCDisassembler::DecodeStatus DecodeStatus;
static const unsigned RegisterDecode[] = {
M68k::D0, M68k::D1, M68k::D2, M68k::D3, M68k::D4, M68k::D5,
M68k::D6, M68k::D7, M68k::A0, M68k::A1, M68k::A2, M68k::A3,
M68k::A4, M68k::A5, M68k::A6, M68k::SP, M68k::FP0, M68k::FP1,
M68k::FP2, M68k::FP3, M68k::FP4, M68k::FP5, M68k::FP6, M68k::FP7,
M68k::FPIAR, M68k::FPS, M68k::FPC};
static DecodeStatus DecodeRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address, const void *Decoder) {
if (RegNo >= 24)
return DecodeStatus::Fail;
Inst.addOperand(MCOperand::createReg(RegisterDecode[RegNo]));
return DecodeStatus::Success;
}
static DecodeStatus DecodeDR32RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeDR16RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeDR8RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeAR32RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo | 8ULL, Address, Decoder);
}
static DecodeStatus DecodeAR16RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo | 8ULL, Address, Decoder);
}
static DecodeStatus DecodeXR32RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeXR16RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeFPDRRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, RegNo | 16ULL, Address, Decoder);
}
#define DecodeFPDR32RegisterClass DecodeFPDRRegisterClass
#define DecodeFPDR64RegisterClass DecodeFPDRRegisterClass
#define DecodeFPDR80RegisterClass DecodeFPDRRegisterClass
static DecodeStatus DecodeFPCSCRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
return DecodeRegisterClass(Inst, (RegNo >> 1) + 24, Address, Decoder);
}
#define DecodeFPICRegisterClass DecodeFPCSCRegisterClass
static DecodeStatus DecodeCCRCRegisterClass(MCInst &Inst, APInt &Insn,
uint64_t Address,
const void *Decoder) {
llvm_unreachable("unimplemented");
}
static DecodeStatus DecodeImm32(MCInst &Inst, uint64_t Imm, uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(M68k::swapWord<uint32_t>(Imm)));
return DecodeStatus::Success;
}
#include "M68kGenDisassemblerTable.inc"
#undef DecodeFPDR32RegisterClass
#undef DecodeFPDR64RegisterClass
#undef DecodeFPDR80RegisterClass
#undef DecodeFPICRegisterClass
/// A disassembler class for M68k.
struct M68kDisassembler : public MCDisassembler {
M68kDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
: MCDisassembler(STI, Ctx) {}
virtual ~M68kDisassembler() {}
DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
ArrayRef<uint8_t> Bytes, uint64_t Address,
raw_ostream &CStream) const override;
};
DecodeStatus M68kDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
ArrayRef<uint8_t> Bytes,
uint64_t Address,
raw_ostream &CStream) const {
DecodeStatus Result;
auto MakeUp = [&](APInt &Insn, unsigned InstrBits) {
unsigned Idx = Insn.getBitWidth() >> 3;
unsigned RoundUp = alignTo(InstrBits, Align(16));
if (RoundUp > Insn.getBitWidth())
Insn = Insn.zext(RoundUp);
RoundUp = RoundUp >> 3;
for (; Idx < RoundUp; Idx += 2) {
Insn.insertBits(support::endian::read16be(&Bytes[Idx]), Idx * 8, 16);
}
};
APInt Insn(16, support::endian::read16be(Bytes.data()));
// 2 bytes of data are consumed, so set Size to 2
// If we don't do this, disassembler may generate result even
// the encoding is invalid. We need to let it fail correctly.
Size = 2;
Result = decodeInstruction(DecoderTable80, Instr, Insn, Address, this, STI,
MakeUp);
if (Result == DecodeStatus::Success)
Size = InstrLenTable[Instr.getOpcode()] >> 3;
return Result;
}
static MCDisassembler *createM68kDisassembler(const Target &T,
const MCSubtargetInfo &STI,
MCContext &Ctx) {
return new M68kDisassembler(STI, Ctx);
}
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeM68kDisassembler() {
// Register the disassembler.
TargetRegistry::RegisterMCDisassembler(getTheM68kTarget(),
createM68kDisassembler);
}
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