//===-- RISCVDisassembler.cpp - Disassembler for RISCV --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the RISCVDisassembler class.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/RISCVBaseInfo.h"
#include "MCTargetDesc/RISCVMCTargetDesc.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 "riscv-disassembler"
typedef MCDisassembler::DecodeStatus DecodeStatus;
namespace {
class RISCVDisassembler : public MCDisassembler {
public:
RISCVDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
: MCDisassembler(STI, Ctx) {}
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 MCDisassembler *createRISCVDisassembler(const Target &T,
const MCSubtargetInfo &STI,
MCContext &Ctx) {
return new RISCVDisassembler(STI, Ctx);
}
extern "C" void LLVMInitializeRISCVDisassembler() {
// Register the disassembler for each target.
TargetRegistry::RegisterMCDisassembler(getTheRISCV32Target(),
createRISCVDisassembler);
TargetRegistry::RegisterMCDisassembler(getTheRISCV64Target(),
createRISCVDisassembler);
}
static const unsigned GPRDecoderTable[] = {
RISCV::X0, RISCV::X1, RISCV::X2, RISCV::X3,
RISCV::X4, RISCV::X5, RISCV::X6, RISCV::X7,
RISCV::X8, RISCV::X9, RISCV::X10, RISCV::X11,
RISCV::X12, RISCV::X13, RISCV::X14, RISCV::X15,
RISCV::X16, RISCV::X17, RISCV::X18, RISCV::X19,
RISCV::X20, RISCV::X21, RISCV::X22, RISCV::X23,
RISCV::X24, RISCV::X25, RISCV::X26, RISCV::X27,
RISCV::X28, RISCV::X29, RISCV::X30, RISCV::X31
};
static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > sizeof(GPRDecoderTable))
return MCDisassembler::Fail;
// We must define our own mapping from RegNo to register identifier.
// Accessing index RegNo in the register class will work in the case that
// registers were added in ascending order, but not in general.
unsigned Reg = GPRDecoderTable[RegNo];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
static const unsigned FPR32DecoderTable[] = {
RISCV::F0_32, RISCV::F1_32, RISCV::F2_32, RISCV::F3_32,
RISCV::F4_32, RISCV::F5_32, RISCV::F6_32, RISCV::F7_32,
RISCV::F8_32, RISCV::F9_32, RISCV::F10_32, RISCV::F11_32,
RISCV::F12_32, RISCV::F13_32, RISCV::F14_32, RISCV::F15_32,
RISCV::F16_32, RISCV::F17_32, RISCV::F18_32, RISCV::F19_32,
RISCV::F20_32, RISCV::F21_32, RISCV::F22_32, RISCV::F23_32,
RISCV::F24_32, RISCV::F25_32, RISCV::F26_32, RISCV::F27_32,
RISCV::F28_32, RISCV::F29_32, RISCV::F30_32, RISCV::F31_32
};
static DecodeStatus DecodeFPR32RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > sizeof(FPR32DecoderTable))
return MCDisassembler::Fail;
// We must define our own mapping from RegNo to register identifier.
// Accessing index RegNo in the register class will work in the case that
// registers were added in ascending order, but not in general.
unsigned Reg = FPR32DecoderTable[RegNo];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
static DecodeStatus DecodeFPR32CRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > 8) {
return MCDisassembler::Fail;
}
unsigned Reg = FPR32DecoderTable[RegNo + 8];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
static const unsigned FPR64DecoderTable[] = {
RISCV::F0_64, RISCV::F1_64, RISCV::F2_64, RISCV::F3_64,
RISCV::F4_64, RISCV::F5_64, RISCV::F6_64, RISCV::F7_64,
RISCV::F8_64, RISCV::F9_64, RISCV::F10_64, RISCV::F11_64,
RISCV::F12_64, RISCV::F13_64, RISCV::F14_64, RISCV::F15_64,
RISCV::F16_64, RISCV::F17_64, RISCV::F18_64, RISCV::F19_64,
RISCV::F20_64, RISCV::F21_64, RISCV::F22_64, RISCV::F23_64,
RISCV::F24_64, RISCV::F25_64, RISCV::F26_64, RISCV::F27_64,
RISCV::F28_64, RISCV::F29_64, RISCV::F30_64, RISCV::F31_64
};
static DecodeStatus DecodeFPR64RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > sizeof(FPR64DecoderTable))
return MCDisassembler::Fail;
// We must define our own mapping from RegNo to register identifier.
// Accessing index RegNo in the register class will work in the case that
// registers were added in ascending order, but not in general.
unsigned Reg = FPR64DecoderTable[RegNo];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
static DecodeStatus DecodeFPR64CRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > 8) {
return MCDisassembler::Fail;
}
unsigned Reg = FPR64DecoderTable[RegNo + 8];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
static DecodeStatus DecodeGPRNoX0RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo == 0) {
return MCDisassembler::Fail;
}
return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeGPRNoX0X2RegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo == 2) {
return MCDisassembler::Fail;
}
return DecodeGPRNoX0RegisterClass(Inst, RegNo, Address, Decoder);
}
static DecodeStatus DecodeGPRCRegisterClass(MCInst &Inst, uint64_t RegNo,
uint64_t Address,
const void *Decoder) {
if (RegNo > 8)
return MCDisassembler::Fail;
unsigned Reg = GPRDecoderTable[RegNo + 8];
Inst.addOperand(MCOperand::createReg(Reg));
return MCDisassembler::Success;
}
// Add implied SP operand for instructions *SP compressed instructions. The SP
// operand isn't explicitly encoded in the instruction.
static void addImplySP(MCInst &Inst, int64_t Address, const void *Decoder) {
if (Inst.getOpcode() == RISCV::C_LWSP || Inst.getOpcode() == RISCV::C_SWSP ||
Inst.getOpcode() == RISCV::C_LDSP || Inst.getOpcode() == RISCV::C_SDSP ||
Inst.getOpcode() == RISCV::C_FLWSP ||
Inst.getOpcode() == RISCV::C_FSWSP ||
Inst.getOpcode() == RISCV::C_FLDSP ||
Inst.getOpcode() == RISCV::C_FSDSP ||
Inst.getOpcode() == RISCV::C_ADDI4SPN) {
DecodeGPRRegisterClass(Inst, 2, Address, Decoder);
}
if (Inst.getOpcode() == RISCV::C_ADDI16SP) {
DecodeGPRRegisterClass(Inst, 2, Address, Decoder);
DecodeGPRRegisterClass(Inst, 2, Address, Decoder);
}
}
template <unsigned N>
static DecodeStatus decodeUImmOperand(MCInst &Inst, uint64_t Imm,
int64_t Address, const void *Decoder) {
assert(isUInt<N>(Imm) && "Invalid immediate");
addImplySP(Inst, Address, Decoder);
Inst.addOperand(MCOperand::createImm(Imm));
return MCDisassembler::Success;
}
template <unsigned N>
static DecodeStatus decodeUImmNonZeroOperand(MCInst &Inst, uint64_t Imm,
int64_t Address,
const void *Decoder) {
if (Imm == 0)
return MCDisassembler::Fail;
return decodeUImmOperand<N>(Inst, Imm, Address, Decoder);
}
template <unsigned N>
static DecodeStatus decodeSImmOperand(MCInst &Inst, uint64_t Imm,
int64_t Address, const void *Decoder) {
assert(isUInt<N>(Imm) && "Invalid immediate");
addImplySP(Inst, Address, Decoder);
// Sign-extend the number in the bottom N bits of Imm
Inst.addOperand(MCOperand::createImm(SignExtend64<N>(Imm)));
return MCDisassembler::Success;
}
template <unsigned N>
static DecodeStatus decodeSImmNonZeroOperand(MCInst &Inst, uint64_t Imm,
int64_t Address,
const void *Decoder) {
if (Imm == 0)
return MCDisassembler::Fail;
return decodeSImmOperand<N>(Inst, Imm, Address, Decoder);
}
template <unsigned N>
static DecodeStatus decodeSImmOperandAndLsl1(MCInst &Inst, uint64_t Imm,
int64_t Address,
const void *Decoder) {
assert(isUInt<N>(Imm) && "Invalid immediate");
// Sign-extend the number in the bottom N bits of Imm after accounting for
// the fact that the N bit immediate is stored in N-1 bits (the LSB is
// always zero)
Inst.addOperand(MCOperand::createImm(SignExtend64<N>(Imm << 1)));
return MCDisassembler::Success;
}
static DecodeStatus decodeCLUIImmOperand(MCInst &Inst, uint64_t Imm,
int64_t Address,
const void *Decoder) {
assert(isUInt<6>(Imm) && "Invalid immediate");
if (Imm > 31) {
Imm = (SignExtend64<6>(Imm) & 0xfffff);
}
Inst.addOperand(MCOperand::createImm(Imm));
return MCDisassembler::Success;
}
static DecodeStatus decodeFRMArg(MCInst &Inst, uint64_t Imm,
int64_t Address,
const void *Decoder) {
assert(isUInt<3>(Imm) && "Invalid immediate");
if (!llvm::RISCVFPRndMode::isValidRoundingMode(Imm))
return MCDisassembler::Fail;
Inst.addOperand(MCOperand::createImm(Imm));
return MCDisassembler::Success;
}
#include "RISCVGenDisassemblerTables.inc"
DecodeStatus RISCVDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
ArrayRef<uint8_t> Bytes,
uint64_t Address,
raw_ostream &OS,
raw_ostream &CS) const {
// TODO: This will need modification when supporting instruction set
// extensions with instructions > 32-bits (up to 176 bits wide).
uint32_t Insn;
DecodeStatus Result;
// It's a 32 bit instruction if bit 0 and 1 are 1.
if ((Bytes[0] & 0x3) == 0x3) {
if (Bytes.size() < 4) {
Size = 0;
return MCDisassembler::Fail;
}
Insn = support::endian::read32le(Bytes.data());
LLVM_DEBUG(dbgs() << "Trying RISCV32 table :\n");
Result = decodeInstruction(DecoderTable32, MI, Insn, Address, this, STI);
Size = 4;
} else {
if (Bytes.size() < 2) {
Size = 0;
return MCDisassembler::Fail;
}
Insn = support::endian::read16le(Bytes.data());
if (!STI.getFeatureBits()[RISCV::Feature64Bit]) {
LLVM_DEBUG(
dbgs() << "Trying RISCV32Only_16 table (16-bit Instruction):\n");
// Calling the auto-generated decoder function.
Result = decodeInstruction(DecoderTableRISCV32Only_16, MI, Insn, Address,
this, STI);
if (Result != MCDisassembler::Fail) {
Size = 2;
return Result;
}
}
LLVM_DEBUG(dbgs() << "Trying RISCV_C table (16-bit Instruction):\n");
// Calling the auto-generated decoder function.
Result = decodeInstruction(DecoderTable16, MI, Insn, Address, this, STI);
Size = 2;
}
return Result;
}