1 //===- SparcDisassembler.cpp - Disassembler for Sparc -----------*- C++ -*-===//
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 is part of the Sparc Disassembler.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/SparcMCTargetDesc.h"
14 #include "TargetInfo/SparcTargetInfo.h"
15 #include "llvm/MC/MCAsmInfo.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/TargetRegistry.h"
21 
22 using namespace llvm;
23 
24 #define DEBUG_TYPE "sparc-disassembler"
25 
26 typedef MCDisassembler::DecodeStatus DecodeStatus;
27 
28 namespace {
29 
30 /// A disassembler class for Sparc.
31 class SparcDisassembler : public MCDisassembler {
32 public:
33   SparcDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
34       : MCDisassembler(STI, Ctx) {}
35   virtual ~SparcDisassembler() = default;
36 
37   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
38                               ArrayRef<uint8_t> Bytes, uint64_t Address,
39                               raw_ostream &CStream) const override;
40 };
41 }
42 
43 static MCDisassembler *createSparcDisassembler(const Target &T,
44                                                const MCSubtargetInfo &STI,
45                                                MCContext &Ctx) {
46   return new SparcDisassembler(STI, Ctx);
47 }
48 
49 
50 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSparcDisassembler() {
51   // Register the disassembler.
52   TargetRegistry::RegisterMCDisassembler(getTheSparcTarget(),
53                                          createSparcDisassembler);
54   TargetRegistry::RegisterMCDisassembler(getTheSparcV9Target(),
55                                          createSparcDisassembler);
56   TargetRegistry::RegisterMCDisassembler(getTheSparcelTarget(),
57                                          createSparcDisassembler);
58 }
59 
60 static const unsigned IntRegDecoderTable[] = {
61   SP::G0,  SP::G1,  SP::G2,  SP::G3,
62   SP::G4,  SP::G5,  SP::G6,  SP::G7,
63   SP::O0,  SP::O1,  SP::O2,  SP::O3,
64   SP::O4,  SP::O5,  SP::O6,  SP::O7,
65   SP::L0,  SP::L1,  SP::L2,  SP::L3,
66   SP::L4,  SP::L5,  SP::L6,  SP::L7,
67   SP::I0,  SP::I1,  SP::I2,  SP::I3,
68   SP::I4,  SP::I5,  SP::I6,  SP::I7 };
69 
70 static const unsigned FPRegDecoderTable[] = {
71   SP::F0,   SP::F1,   SP::F2,   SP::F3,
72   SP::F4,   SP::F5,   SP::F6,   SP::F7,
73   SP::F8,   SP::F9,   SP::F10,  SP::F11,
74   SP::F12,  SP::F13,  SP::F14,  SP::F15,
75   SP::F16,  SP::F17,  SP::F18,  SP::F19,
76   SP::F20,  SP::F21,  SP::F22,  SP::F23,
77   SP::F24,  SP::F25,  SP::F26,  SP::F27,
78   SP::F28,  SP::F29,  SP::F30,  SP::F31 };
79 
80 static const unsigned DFPRegDecoderTable[] = {
81   SP::D0,   SP::D16,  SP::D1,   SP::D17,
82   SP::D2,   SP::D18,  SP::D3,   SP::D19,
83   SP::D4,   SP::D20,  SP::D5,   SP::D21,
84   SP::D6,   SP::D22,  SP::D7,   SP::D23,
85   SP::D8,   SP::D24,  SP::D9,   SP::D25,
86   SP::D10,  SP::D26,  SP::D11,  SP::D27,
87   SP::D12,  SP::D28,  SP::D13,  SP::D29,
88   SP::D14,  SP::D30,  SP::D15,  SP::D31 };
89 
90 static const unsigned QFPRegDecoderTable[] = {
91   SP::Q0,  SP::Q8,   ~0U,  ~0U,
92   SP::Q1,  SP::Q9,   ~0U,  ~0U,
93   SP::Q2,  SP::Q10,  ~0U,  ~0U,
94   SP::Q3,  SP::Q11,  ~0U,  ~0U,
95   SP::Q4,  SP::Q12,  ~0U,  ~0U,
96   SP::Q5,  SP::Q13,  ~0U,  ~0U,
97   SP::Q6,  SP::Q14,  ~0U,  ~0U,
98   SP::Q7,  SP::Q15,  ~0U,  ~0U } ;
99 
100 static const unsigned FCCRegDecoderTable[] = {
101   SP::FCC0, SP::FCC1, SP::FCC2, SP::FCC3 };
102 
103 static const unsigned ASRRegDecoderTable[] = {
104     SP::Y,     SP::ASR1,  SP::ASR2,  SP::ASR3,  SP::ASR4,  SP::ASR5,  SP::ASR6,
105     SP::ASR7,  SP::ASR8,  SP::ASR9,  SP::ASR10, SP::ASR11, SP::ASR12, SP::ASR13,
106     SP::ASR14, SP::ASR15, SP::ASR16, SP::ASR17, SP::ASR18, SP::ASR19, SP::ASR20,
107     SP::ASR21, SP::ASR22, SP::ASR23, SP::ASR24, SP::ASR25, SP::ASR26, SP::ASR27,
108     SP::ASR28, SP::ASR29, SP::ASR30, SP::ASR31};
109 
110 static const unsigned PRRegDecoderTable[] = {
111     SP::TPC,     SP::TNPC,       SP::TSTATE,   SP::TT,       SP::TICK,
112     SP::TBA,     SP::PSTATE,     SP::TL,       SP::PIL,      SP::CWP,
113     SP::CANSAVE, SP::CANRESTORE, SP::CLEANWIN, SP::OTHERWIN, SP::WSTATE};
114 
115 static const uint16_t IntPairDecoderTable[] = {
116   SP::G0_G1, SP::G2_G3, SP::G4_G5, SP::G6_G7,
117   SP::O0_O1, SP::O2_O3, SP::O4_O5, SP::O6_O7,
118   SP::L0_L1, SP::L2_L3, SP::L4_L5, SP::L6_L7,
119   SP::I0_I1, SP::I2_I3, SP::I4_I5, SP::I6_I7,
120 };
121 
122 static const unsigned CPRegDecoderTable[] = {
123   SP::C0,  SP::C1,  SP::C2,  SP::C3,
124   SP::C4,  SP::C5,  SP::C6,  SP::C7,
125   SP::C8,  SP::C9,  SP::C10, SP::C11,
126   SP::C12, SP::C13, SP::C14, SP::C15,
127   SP::C16, SP::C17, SP::C18, SP::C19,
128   SP::C20, SP::C21, SP::C22, SP::C23,
129   SP::C24, SP::C25, SP::C26, SP::C27,
130   SP::C28, SP::C29, SP::C30, SP::C31
131 };
132 
133 
134 static const uint16_t CPPairDecoderTable[] = {
135   SP::C0_C1,   SP::C2_C3,   SP::C4_C5,   SP::C6_C7,
136   SP::C8_C9,   SP::C10_C11, SP::C12_C13, SP::C14_C15,
137   SP::C16_C17, SP::C18_C19, SP::C20_C21, SP::C22_C23,
138   SP::C24_C25, SP::C26_C27, SP::C28_C29, SP::C30_C31
139 };
140 
141 static DecodeStatus DecodeIntRegsRegisterClass(MCInst &Inst, unsigned RegNo,
142                                                uint64_t Address,
143                                                const MCDisassembler *Decoder) {
144   if (RegNo > 31)
145     return MCDisassembler::Fail;
146   unsigned Reg = IntRegDecoderTable[RegNo];
147   Inst.addOperand(MCOperand::createReg(Reg));
148   return MCDisassembler::Success;
149 }
150 
151 static DecodeStatus DecodeI64RegsRegisterClass(MCInst &Inst, unsigned RegNo,
152                                                uint64_t Address,
153                                                const MCDisassembler *Decoder) {
154   return DecodeIntRegsRegisterClass(Inst, RegNo, Address, Decoder);
155 }
156 
157 // This is used for the type "ptr_rc", which is either IntRegs or I64Regs
158 // depending on SparcRegisterInfo::getPointerRegClass.
159 static DecodeStatus DecodePointerLikeRegClass0(MCInst &Inst, unsigned RegNo,
160                                                uint64_t Address,
161                                                const MCDisassembler *Decoder) {
162   return DecodeIntRegsRegisterClass(Inst, RegNo, Address, Decoder);
163 }
164 
165 static DecodeStatus DecodeFPRegsRegisterClass(MCInst &Inst, unsigned RegNo,
166                                               uint64_t Address,
167                                               const MCDisassembler *Decoder) {
168   if (RegNo > 31)
169     return MCDisassembler::Fail;
170   unsigned Reg = FPRegDecoderTable[RegNo];
171   Inst.addOperand(MCOperand::createReg(Reg));
172   return MCDisassembler::Success;
173 }
174 
175 static DecodeStatus DecodeDFPRegsRegisterClass(MCInst &Inst, unsigned RegNo,
176                                                uint64_t Address,
177                                                const MCDisassembler *Decoder) {
178   if (RegNo > 31)
179     return MCDisassembler::Fail;
180   unsigned Reg = DFPRegDecoderTable[RegNo];
181   Inst.addOperand(MCOperand::createReg(Reg));
182   return MCDisassembler::Success;
183 }
184 
185 static DecodeStatus DecodeQFPRegsRegisterClass(MCInst &Inst, unsigned RegNo,
186                                                uint64_t Address,
187                                                const MCDisassembler *Decoder) {
188   if (RegNo > 31)
189     return MCDisassembler::Fail;
190 
191   unsigned Reg = QFPRegDecoderTable[RegNo];
192   if (Reg == ~0U)
193     return MCDisassembler::Fail;
194   Inst.addOperand(MCOperand::createReg(Reg));
195   return MCDisassembler::Success;
196 }
197 
198 static DecodeStatus
199 DecodeCoprocRegsRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
200                               const MCDisassembler *Decoder) {
201   if (RegNo > 31)
202     return MCDisassembler::Fail;
203   unsigned Reg = CPRegDecoderTable[RegNo];
204   Inst.addOperand(MCOperand::createReg(Reg));
205   return MCDisassembler::Success;
206 }
207 
208 static DecodeStatus DecodeFCCRegsRegisterClass(MCInst &Inst, unsigned RegNo,
209                                                uint64_t Address,
210                                                const MCDisassembler *Decoder) {
211   if (RegNo > 3)
212     return MCDisassembler::Fail;
213   Inst.addOperand(MCOperand::createReg(FCCRegDecoderTable[RegNo]));
214   return MCDisassembler::Success;
215 }
216 
217 static DecodeStatus DecodeASRRegsRegisterClass(MCInst &Inst, unsigned RegNo,
218                                                uint64_t Address,
219                                                const MCDisassembler *Decoder) {
220   if (RegNo > 31)
221     return MCDisassembler::Fail;
222   Inst.addOperand(MCOperand::createReg(ASRRegDecoderTable[RegNo]));
223   return MCDisassembler::Success;
224 }
225 
226 static DecodeStatus DecodePRRegsRegisterClass(MCInst &Inst, unsigned RegNo,
227                                               uint64_t Address,
228                                               const MCDisassembler *Decoder) {
229   if (RegNo >= std::size(PRRegDecoderTable))
230     return MCDisassembler::Fail;
231   Inst.addOperand(MCOperand::createReg(PRRegDecoderTable[RegNo]));
232   return MCDisassembler::Success;
233 }
234 
235 static DecodeStatus DecodeIntPairRegisterClass(MCInst &Inst, unsigned RegNo,
236                                                uint64_t Address,
237                                                const MCDisassembler *Decoder) {
238   DecodeStatus S = MCDisassembler::Success;
239 
240   if (RegNo > 31)
241     return MCDisassembler::Fail;
242 
243   if ((RegNo & 1))
244     S = MCDisassembler::SoftFail;
245 
246   unsigned RegisterPair = IntPairDecoderTable[RegNo/2];
247   Inst.addOperand(MCOperand::createReg(RegisterPair));
248   return S;
249 }
250 
251 static DecodeStatus
252 DecodeCoprocPairRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
253                               const MCDisassembler *Decoder) {
254   if (RegNo > 31)
255     return MCDisassembler::Fail;
256 
257   unsigned RegisterPair = CPPairDecoderTable[RegNo/2];
258   Inst.addOperand(MCOperand::createReg(RegisterPair));
259   return MCDisassembler::Success;
260 }
261 
262 static DecodeStatus DecodeCall(MCInst &Inst, unsigned insn, uint64_t Address,
263                                const MCDisassembler *Decoder);
264 static DecodeStatus DecodeSIMM13(MCInst &Inst, unsigned insn, uint64_t Address,
265                                  const MCDisassembler *Decoder);
266 
267 #include "SparcGenDisassemblerTables.inc"
268 
269 /// Read four bytes from the ArrayRef and return 32 bit word.
270 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
271                                       uint64_t &Size, uint32_t &Insn,
272                                       bool IsLittleEndian) {
273   // We want to read exactly 4 Bytes of data.
274   if (Bytes.size() < 4) {
275     Size = 0;
276     return MCDisassembler::Fail;
277   }
278 
279   Insn = IsLittleEndian
280              ? (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
281                    (Bytes[3] << 24)
282              : (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) |
283                    (Bytes[0] << 24);
284 
285   return MCDisassembler::Success;
286 }
287 
288 DecodeStatus SparcDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
289                                                ArrayRef<uint8_t> Bytes,
290                                                uint64_t Address,
291                                                raw_ostream &CStream) const {
292   uint32_t Insn;
293   bool isLittleEndian = getContext().getAsmInfo()->isLittleEndian();
294   DecodeStatus Result =
295       readInstruction32(Bytes, Address, Size, Insn, isLittleEndian);
296   if (Result == MCDisassembler::Fail)
297     return MCDisassembler::Fail;
298 
299   // Calling the auto-generated decoder function.
300 
301   if (STI.hasFeature(Sparc::FeatureV9))
302   {
303     Result = decodeInstruction(DecoderTableSparcV932, Instr, Insn, Address, this, STI);
304   }
305   else
306   {
307     Result = decodeInstruction(DecoderTableSparcV832, Instr, Insn, Address, this, STI);
308   }
309   if (Result != MCDisassembler::Fail) {
310     Size = 4;
311     return Result;
312   }
313 
314   Result =
315       decodeInstruction(DecoderTableSparc32, Instr, Insn, Address, this, STI);
316 
317   if (Result != MCDisassembler::Fail) {
318     Size = 4;
319     return Result;
320   }
321 
322   return MCDisassembler::Fail;
323 }
324 
325 static bool tryAddingSymbolicOperand(int64_t Value, bool isBranch,
326                                      uint64_t Address, uint64_t Offset,
327                                      uint64_t Width, MCInst &MI,
328                                      const MCDisassembler *Decoder) {
329   return Decoder->tryAddingSymbolicOperand(MI, Value, Address, isBranch, Offset,
330                                            Width, /*InstSize=*/4);
331 }
332 
333 static DecodeStatus DecodeCall(MCInst &MI, unsigned insn, uint64_t Address,
334                                const MCDisassembler *Decoder) {
335   unsigned tgt = fieldFromInstruction(insn, 0, 30);
336   tgt <<= 2;
337   if (!tryAddingSymbolicOperand(tgt+Address, false, Address,
338                                 0, 30, MI, Decoder))
339     MI.addOperand(MCOperand::createImm(tgt));
340   return MCDisassembler::Success;
341 }
342 
343 static DecodeStatus DecodeSIMM13(MCInst &MI, unsigned insn, uint64_t Address,
344                                  const MCDisassembler *Decoder) {
345   assert(isUInt<13>(insn));
346   MI.addOperand(MCOperand::createImm(SignExtend64<13>(insn)));
347   return MCDisassembler::Success;
348 }
349