llvm/lib/Target/LoongArch/Disassembler/LoongArchDisassembler.cpp

   1 //===-- LoongArchDisassembler.cpp - Disassembler for LoongArch ------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the LoongArchDisassembler class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "MCTargetDesc/LoongArchBaseInfo.h"
  14 #include "MCTargetDesc/LoongArchMCTargetDesc.h"
  15 #include "TargetInfo/LoongArchTargetInfo.h"
  16 #include "llvm/MC/MCContext.h"
  17 #include "llvm/MC/MCDecoderOps.h"
  18 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
  19 #include "llvm/MC/MCInst.h"
  20 #include "llvm/MC/MCInstrInfo.h"
  21 #include "llvm/MC/MCRegisterInfo.h"
  22 #include "llvm/MC/MCSubtargetInfo.h"
  23 #include "llvm/MC/TargetRegistry.h"
  24 #include "llvm/Support/Endian.h"
  25
  26 using namespace llvm;
  27
  28 #define DEBUG_TYPE "loongarch-disassembler"
  29
  30 typedef MCDisassembler::DecodeStatus DecodeStatus;
  31
  32 namespace {
  33 class LoongArchDisassembler : public MCDisassembler {
  34 public:
  35   LoongArchDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
  36       : MCDisassembler(STI, Ctx) {}
  37
  38   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
  39                               ArrayRef<uint8_t> Bytes, uint64_t Address,
  40                               raw_ostream &CStream) const override;
  41 };
  42 } // end namespace
  43
  44 static MCDisassembler *createLoongArchDisassembler(const Target &T,
  45                                                    const MCSubtargetInfo &STI,
  46                                                    MCContext &Ctx) {
  47   return new LoongArchDisassembler(STI, Ctx);
  48 }
  49
  50 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchDisassembler() {
  51   // Register the disassembler for each target.
  52   TargetRegistry::RegisterMCDisassembler(getTheLoongArch32Target(),
  53                                          createLoongArchDisassembler);
  54   TargetRegistry::RegisterMCDisassembler(getTheLoongArch64Target(),
  55                                          createLoongArchDisassembler);
  56 }
  57
  58 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, uint64_t RegNo,
  59                                            uint64_t Address,
  60                                            const MCDisassembler *Decoder) {
  61   if (RegNo >= 32)
  62     return MCDisassembler::Fail;
  63   Inst.addOperand(MCOperand::createReg(LoongArch::R0 + RegNo));
  64   return MCDisassembler::Success;
  65 }
  66
  67 static DecodeStatus DecodeFPR32RegisterClass(MCInst &Inst, uint64_t RegNo,
  68                                              uint64_t Address,
  69                                              const MCDisassembler *Decoder) {
  70   if (RegNo >= 32)
  71     return MCDisassembler::Fail;
  72   Inst.addOperand(MCOperand::createReg(LoongArch::F0 + RegNo));
  73   return MCDisassembler::Success;
  74 }
  75
  76 static DecodeStatus DecodeFPR64RegisterClass(MCInst &Inst, uint64_t RegNo,
  77                                              uint64_t Address,
  78                                              const MCDisassembler *Decoder) {
  79   if (RegNo >= 32)
  80     return MCDisassembler::Fail;
  81   Inst.addOperand(MCOperand::createReg(LoongArch::F0_64 + RegNo));
  82   return MCDisassembler::Success;
  83 }
  84
  85 static DecodeStatus DecodeCFRRegisterClass(MCInst &Inst, uint64_t RegNo,
  86                                            uint64_t Address,
  87                                            const MCDisassembler *Decoder) {
  88   if (RegNo >= 8)
  89     return MCDisassembler::Fail;
  90   Inst.addOperand(MCOperand::createReg(LoongArch::FCC0 + RegNo));
  91   return MCDisassembler::Success;
  92 }
  93
  94 static DecodeStatus DecodeFCSRRegisterClass(MCInst &Inst, uint64_t RegNo,
  95                                             uint64_t Address,
  96                                             const MCDisassembler *Decoder) {
  97   if (RegNo >= 4)
  98     return MCDisassembler::Fail;
  99   Inst.addOperand(MCOperand::createReg(LoongArch::FCSR0 + RegNo));
 100   return MCDisassembler::Success;
 101 }
 102
 103 static DecodeStatus DecodeLSX128RegisterClass(MCInst &Inst, uint64_t RegNo,
 104                                               uint64_t Address,
 105                                               const MCDisassembler *Decoder) {
 106   if (RegNo >= 32)
 107     return MCDisassembler::Fail;
 108   Inst.addOperand(MCOperand::createReg(LoongArch::VR0 + RegNo));
 109   return MCDisassembler::Success;
 110 }
 111
 112 static DecodeStatus DecodeLASX256RegisterClass(MCInst &Inst, uint64_t RegNo,
 113                                                uint64_t Address,
 114                                                const MCDisassembler *Decoder) {
 115   if (RegNo >= 32)
 116     return MCDisassembler::Fail;
 117   Inst.addOperand(MCOperand::createReg(LoongArch::XR0 + RegNo));
 118   return MCDisassembler::Success;
 119 }
 120
 121 static DecodeStatus DecodeSCRRegisterClass(MCInst &Inst, uint64_t RegNo,
 122                                            uint64_t Address,
 123                                            const MCDisassembler *Decoder) {
 124   if (RegNo >= 4)
 125     return MCDisassembler::Fail;
 126   Inst.addOperand(MCOperand::createReg(LoongArch::SCR0 + RegNo));
 127   return MCDisassembler::Success;
 128 }
 129
 130 template <unsigned N, int P = 0>
 131 static DecodeStatus decodeUImmOperand(MCInst &Inst, uint64_t Imm,
 132                                       int64_t Address,
 133                                       const MCDisassembler *Decoder) {
 134   assert(isUInt<N>(Imm) && "Invalid immediate");
 135   Inst.addOperand(MCOperand::createImm(Imm + P));
 136   return MCDisassembler::Success;
 137 }
 138
 139 template <unsigned N, unsigned S = 0>
 140 static DecodeStatus decodeSImmOperand(MCInst &Inst, uint64_t Imm,
 141                                       int64_t Address,
 142                                       const MCDisassembler *Decoder) {
 143   assert(isUInt<N>(Imm) && "Invalid immediate");
 144   // Shift left Imm <S> bits, then sign-extend the number in the bottom <N+S>
 145   // bits.
 146   Inst.addOperand(MCOperand::createImm(SignExtend64<N + S>(Imm << S)));
 147   return MCDisassembler::Success;
 148 }
 149
 150 #include "LoongArchGenDisassemblerTables.inc"
 151
 152 DecodeStatus LoongArchDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
 153                                                    ArrayRef<uint8_t> Bytes,
 154                                                    uint64_t Address,
 155                                                    raw_ostream &CS) const {
 156   uint32_t Insn;
 157   DecodeStatus Result;
 158
 159   // We want to read exactly 4 bytes of data because all LoongArch instructions
 160   // are fixed 32 bits.
 161   if (Bytes.size() < 4) {
 162     Size = 0;
 163     return MCDisassembler::Fail;
 164   }
 165
 166   Insn = support::endian::read32le(Bytes.data());
 167   // Calling the auto-generated decoder function.
 168   Result = decodeInstruction(DecoderTable32, MI, Insn, Address, this, STI);
 169   Size = 4;
 170
 171   return Result;
 172 }