1 files changed, 153 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/M68k/Disassembler/M68kDisassembler.cpp b/contrib/llvm-project/llvm/lib/Target/M68k/Disassembler/M68kDisassembler.cpp
new file mode 100644
index 000000000000..ffe4869e8fe5
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Target/M68k/Disassembler/M68kDisassembler.cpp
@@ -0,0 +1,153 @@
+//===-- 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,
+};
+
+static DecodeStatus DecodeRegisterClass(MCInst &Inst, uint64_t RegNo,
+                                        uint64_t Address, const void *Decoder) {
+  if (RegNo >= 16)
+    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 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"
+
+/// 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);
+}