llvm-project/llvm/lib/Target/ARC/Disassembler/ARCDisassembler.cpp

299 lines
11 KiB
C++

//===- ARCDisassembler.cpp - Disassembler for ARC ---------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file is part of the ARC Disassembler.
///
//===----------------------------------------------------------------------===//
#include "ARC.h"
#include "ARCRegisterInfo.h"
#include "MCTargetDesc/ARCMCTargetDesc.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/MCInstrInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
#define DEBUG_TYPE "arc-disassembler"
using DecodeStatus = MCDisassembler::DecodeStatus;
namespace {
/// \brief A disassembler class for ARC.
class ARCDisassembler : public MCDisassembler {
public:
std::unique_ptr<MCInstrInfo const> const MCII;
ARCDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
MCInstrInfo const *MCII)
: MCDisassembler(STI, Ctx), MCII(MCII) {}
DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
ArrayRef<uint8_t> Bytes, uint64_t Address,
raw_ostream &VStream,
raw_ostream &CStream) const override;
};
} // end anonymous namespace
static bool readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
uint64_t &Size, uint32_t &Insn) {
Size = 4;
// Read 2 16-bit values, but swap hi/lo parts.
Insn =
(Bytes[0] << 16) | (Bytes[1] << 24) | (Bytes[2] << 0) | (Bytes[3] << 8);
return true;
}
static bool readInstruction64(ArrayRef<uint8_t> Bytes, uint64_t Address,
uint64_t &Size, uint64_t &Insn) {
Size = 8;
Insn = ((uint64_t)Bytes[0] << 16) | ((uint64_t)Bytes[1] << 24) |
((uint64_t)Bytes[2] << 0) | ((uint64_t)Bytes[3] << 8) |
((uint64_t)Bytes[4] << 48) | ((uint64_t)Bytes[5] << 56) |
((uint64_t)Bytes[6] << 32) | ((uint64_t)Bytes[7] << 40);
return true;
}
static bool readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
uint64_t &Size, uint32_t &Insn) {
Size = 2;
Insn = (Bytes[0] << 0) | (Bytes[1] << 8);
return true;
}
static MCDisassembler::DecodeStatus DecodeS12Operand(MCInst &, unsigned,
uint64_t, const void *);
static MCDisassembler::DecodeStatus DecodeS9Operand(MCInst &, unsigned,
uint64_t, const void *);
static MCDisassembler::DecodeStatus
DecodeBranchTargetS9(MCInst &, unsigned, uint64_t, const void *);
static MCDisassembler::DecodeStatus
DecodeBranchTargetS21(MCInst &, unsigned, uint64_t, const void *);
static MCDisassembler::DecodeStatus
DecodeBranchTargetS25(MCInst &, unsigned, uint64_t, const void *);
static MCDisassembler::DecodeStatus DecodeMEMrs9(MCInst &, unsigned, uint64_t,
const void *);
static MCDisassembler::DecodeStatus
DecodeLdLImmInstruction(MCInst &, uint64_t, uint64_t, const void *);
static MCDisassembler::DecodeStatus
DecodeStLImmInstruction(MCInst &, uint64_t, uint64_t, const void *);
static MCDisassembler::DecodeStatus
DecodeLdRLImmInstruction(MCInst &, uint64_t, uint64_t, const void *);
static const uint16_t GPR32DecoderTable[] = {
ARC::R0, ARC::R1, ARC::R2, ARC::R3, ARC::R4, ARC::R5, ARC::R6,
ARC::R7, ARC::R8, ARC::R9, ARC::R10, ARC::R11, ARC::R12, ARC::R13,
ARC::R14, ARC::R15, ARC::R16, ARC::R17, ARC::R18, ARC::R19, ARC::R20,
ARC::R21, ARC::R22, ARC::R23, ARC::R24, ARC::R25, ARC::GP, ARC::FP,
ARC::SP, ARC::ILINK, ARC::R30, ARC::BLINK};
static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst, unsigned RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo >= 32) {
DEBUG(dbgs() << "Not a GPR32 register.");
return MCDisassembler::Fail;
}
unsigned Reg = GPR32DecoderTable[RegNo];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
#include "ARCGenDisassemblerTables.inc"
static unsigned decodeCField(unsigned Insn) {
return fieldFromInstruction(Insn, 6, 6);
}
static unsigned decodeBField(unsigned Insn) {
return (fieldFromInstruction(Insn, 12, 3) << 3) |
fieldFromInstruction(Insn, 24, 3);
}
static unsigned decodeAField(unsigned Insn) {
return fieldFromInstruction(Insn, 0, 6);
}
static MCDisassembler::DecodeStatus
DecodeMEMrs9(MCInst &Inst, unsigned Insn, uint64_t Address, const void *Dec) {
// We have the 9-bit immediate in the low bits, 6-bit register in high bits.
unsigned S9 = Insn & 0x1ff;
unsigned R = (Insn & (0x7fff & ~0x1ff)) >> 9;
DecodeGPR32RegisterClass(Inst, R, Address, Dec);
Inst.addOperand(MCOperand::createImm(SignExtend32<9>(S9)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus DecodeS9Operand(MCInst &Inst,
unsigned InsnS9,
uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(SignExtend32<9>(0x1ff & InsnS9)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus DecodeS12Operand(MCInst &Inst,
unsigned InsnS12,
uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(SignExtend32<12>(0xfff & InsnS12)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus DecodeBranchTargetS9(MCInst &Inst,
unsigned S,
uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(SignExtend32<9>(S)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus DecodeBranchTargetS21(MCInst &Inst,
unsigned S,
uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(SignExtend32<21>(S)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus DecodeBranchTargetS25(MCInst &Inst,
unsigned S,
uint64_t Address,
const void *Decoder) {
Inst.addOperand(MCOperand::createImm(SignExtend32<25>(S)));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus
DecodeStLImmInstruction(MCInst &Inst, uint64_t Insn, uint64_t Address,
const void *Decoder) {
unsigned SrcC, DstB, LImm;
DstB = decodeBField(Insn);
if (DstB != 62) {
DEBUG(dbgs() << "Decoding StLImm found non-limm register.");
return MCDisassembler::Fail;
}
SrcC = decodeCField(Insn);
DecodeGPR32RegisterClass(Inst, SrcC, Address, Decoder);
LImm = (Insn >> 32);
Inst.addOperand(MCOperand::createImm(LImm));
Inst.addOperand(MCOperand::createImm(0));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus
DecodeLdLImmInstruction(MCInst &Inst, uint64_t Insn, uint64_t Address,
const void *Decoder) {
unsigned DstA, SrcB, LImm;
DEBUG(dbgs() << "Decoding LdLImm:\n");
SrcB = decodeBField(Insn);
if (SrcB != 62) {
DEBUG(dbgs() << "Decoding LdLImm found non-limm register.");
return MCDisassembler::Fail;
}
DstA = decodeAField(Insn);
DecodeGPR32RegisterClass(Inst, DstA, Address, Decoder);
LImm = (Insn >> 32);
Inst.addOperand(MCOperand::createImm(LImm));
Inst.addOperand(MCOperand::createImm(0));
return MCDisassembler::Success;
}
static MCDisassembler::DecodeStatus
DecodeLdRLImmInstruction(MCInst &Inst, uint64_t Insn, uint64_t Address,
const void *Decoder) {
unsigned DstA, SrcB;
DEBUG(dbgs() << "Decoding LdRLimm\n");
DstA = decodeAField(Insn);
DecodeGPR32RegisterClass(Inst, DstA, Address, Decoder);
SrcB = decodeBField(Insn);
DecodeGPR32RegisterClass(Inst, SrcB, Address, Decoder);
if (decodeCField(Insn) != 62) {
DEBUG(dbgs() << "Decoding LdRLimm found non-limm register.");
return MCDisassembler::Fail;
}
Inst.addOperand(MCOperand::createImm((uint32_t)(Insn >> 32)));
return MCDisassembler::Success;
}
MCDisassembler::DecodeStatus ARCDisassembler::getInstruction(
MCInst &Instr, uint64_t &Size, ArrayRef<uint8_t> Bytes, uint64_t Address,
raw_ostream &vStream, raw_ostream &cStream) const {
MCDisassembler::DecodeStatus Result;
if (Bytes.size() < 2) {
Size = 0;
return Fail;
}
uint8_t DecodeByte = (Bytes[1] & 0xF7) >> 3;
// 0x00 -> 0x07 are 32-bit instructions.
// 0x08 -> 0x1F are 16-bit instructions.
if (DecodeByte < 0x08) {
// 32-bit instruction.
if (Bytes.size() < 4) {
// Did we decode garbage?
Size = 0;
return Fail;
}
if (Bytes.size() >= 8) {
// Attempt to decode 64-bit instruction.
uint64_t Insn64;
if (!readInstruction64(Bytes, Address, Size, Insn64))
return Fail;
Result =
decodeInstruction(DecoderTable64, Instr, Insn64, Address, this, STI);
if (Result == MCDisassembler::Success) {
DEBUG(dbgs() << "Successfully decoded 64-bit instruction.");
return MCDisassembler::Success;
}
DEBUG(dbgs() << "Not a 64-bit instruction, falling back to 32-bit.");
}
uint32_t Insn32;
if (!readInstruction32(Bytes, Address, Size, Insn32)) {
return Fail;
}
// Calling the auto-generated decoder function.
return decodeInstruction(DecoderTable32, Instr, Insn32, Address, this, STI);
}
// 16-bit instruction.
uint32_t Insn16;
if (!readInstruction16(Bytes, Address, Size, Insn16)) {
return Fail;
}
// Calling the auto-generated decoder function.
return decodeInstruction(DecoderTable16, Instr, Insn16, Address, this, STI);
}
static MCDisassembler *createARCDisassembler(const Target &T,
const MCSubtargetInfo &STI,
MCContext &Ctx) {
return new ARCDisassembler(STI, Ctx, T.createMCInstrInfo());
}
extern "C" void LLVMInitializeARCDisassembler() {
// Register the disassembler.
TargetRegistry::RegisterMCDisassembler(getTheARCTarget(),
createARCDisassembler);
}