xref: /llvm-project/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp (revision 484ca1a0305fc5ea3eb34ccfa7e2f2440209252f)
1 //===- SparcDisassembler.cpp - Disassembler for Sparc -----------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is part of the Sparc Disassembler.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #define DEBUG_TYPE "sparc-disassembler"
15 
16 #include "Sparc.h"
17 #include "SparcRegisterInfo.h"
18 #include "SparcSubtarget.h"
19 #include "llvm/MC/MCDisassembler.h"
20 #include "llvm/MC/MCFixedLenDisassembler.h"
21 #include "llvm/Support/MemoryObject.h"
22 #include "llvm/Support/TargetRegistry.h"
23 
24 using namespace llvm;
25 
26 typedef MCDisassembler::DecodeStatus DecodeStatus;
27 
28 namespace {
29 
30 /// SparcDisassembler - a disassembler class for Sparc.
31 class SparcDisassembler : public MCDisassembler {
32 public:
33   /// Constructor     - Initializes the disassembler.
34   ///
35   SparcDisassembler(const MCSubtargetInfo &STI, const MCRegisterInfo *Info) :
36     MCDisassembler(STI), RegInfo(Info)
37   {}
38   virtual ~SparcDisassembler() {}
39 
40   const MCRegisterInfo *getRegInfo() const { return RegInfo.get(); }
41 
42   /// getInstruction - See MCDisassembler.
43   virtual DecodeStatus getInstruction(MCInst &instr,
44                                       uint64_t &size,
45                                       const MemoryObject &region,
46                                       uint64_t address,
47                                       raw_ostream &vStream,
48                                       raw_ostream &cStream) const;
49 private:
50   OwningPtr<const MCRegisterInfo> RegInfo;
51 };
52 
53 }
54 
55 namespace llvm {
56   extern Target TheSparcTarget, TheSparcV9Target;
57 }
58 
59 static MCDisassembler *createSparcDisassembler(
60                        const Target &T,
61                        const MCSubtargetInfo &STI) {
62   return new SparcDisassembler(STI, T.createMCRegInfo(""));
63 }
64 
65 
66 extern "C" void LLVMInitializeSparcDisassembler() {
67   // Register the disassembler.
68   TargetRegistry::RegisterMCDisassembler(TheSparcTarget,
69                                          createSparcDisassembler);
70   TargetRegistry::RegisterMCDisassembler(TheSparcV9Target,
71                                          createSparcDisassembler);
72 }
73 
74 
75 
76 static const unsigned IntRegDecoderTable[] = {
77   SP::G0,  SP::G1,  SP::G2,  SP::G3,
78   SP::G4,  SP::G5,  SP::G6,  SP::G7,
79   SP::O0,  SP::O1,  SP::O2,  SP::O3,
80   SP::O4,  SP::O5,  SP::O6,  SP::O7,
81   SP::L0,  SP::L1,  SP::L2,  SP::L3,
82   SP::L4,  SP::L5,  SP::L6,  SP::L7,
83   SP::I0,  SP::I1,  SP::I2,  SP::I3,
84   SP::I4,  SP::I5,  SP::I6,  SP::I7 };
85 
86 static const unsigned FPRegDecoderTable[] = {
87   SP::F0,   SP::F1,   SP::F2,   SP::F3,
88   SP::F4,   SP::F5,   SP::F6,   SP::F7,
89   SP::F8,   SP::F9,   SP::F10,  SP::F11,
90   SP::F12,  SP::F13,  SP::F14,  SP::F15,
91   SP::F16,  SP::F17,  SP::F18,  SP::F19,
92   SP::F20,  SP::F21,  SP::F22,  SP::F23,
93   SP::F24,  SP::F25,  SP::F26,  SP::F27,
94   SP::F28,  SP::F29,  SP::F30,  SP::F31 };
95 
96 static const unsigned DFPRegDecoderTable[] = {
97   SP::D0,   SP::D16,  SP::D1,   SP::D17,
98   SP::D2,   SP::D18,  SP::D3,   SP::D19,
99   SP::D4,   SP::D20,  SP::D5,   SP::D21,
100   SP::D6,   SP::D22,  SP::D7,   SP::D23,
101   SP::D8,   SP::D24,  SP::D9,   SP::D25,
102   SP::D10,  SP::D26,  SP::D11,  SP::D27,
103   SP::D12,  SP::D28,  SP::D13,  SP::D29,
104   SP::D14,  SP::D30,  SP::D15,  SP::D31 };
105 
106 static const unsigned QFPRegDecoderTable[] = {
107   SP::Q0,  SP::Q8,   ~0U,  ~0U,
108   SP::Q1,  SP::Q9,   ~0U,  ~0U,
109   SP::Q2,  SP::Q10,  ~0U,  ~0U,
110   SP::Q3,  SP::Q11,  ~0U,  ~0U,
111   SP::Q4,  SP::Q12,  ~0U,  ~0U,
112   SP::Q5,  SP::Q13,  ~0U,  ~0U,
113   SP::Q6,  SP::Q14,  ~0U,  ~0U,
114   SP::Q7,  SP::Q15,  ~0U,  ~0U } ;
115 
116 static DecodeStatus DecodeIntRegsRegisterClass(MCInst &Inst,
117                                                unsigned RegNo,
118                                                uint64_t Address,
119                                                const void *Decoder) {
120   if (RegNo > 31)
121     return MCDisassembler::Fail;
122   unsigned Reg = IntRegDecoderTable[RegNo];
123   Inst.addOperand(MCOperand::CreateReg(Reg));
124   return MCDisassembler::Success;
125 }
126 
127 static DecodeStatus DecodeI64RegsRegisterClass(MCInst &Inst,
128                                                unsigned RegNo,
129                                                uint64_t Address,
130                                                const void *Decoder) {
131   if (RegNo > 31)
132     return MCDisassembler::Fail;
133   unsigned Reg = IntRegDecoderTable[RegNo];
134   Inst.addOperand(MCOperand::CreateReg(Reg));
135   return MCDisassembler::Success;
136 }
137 
138 
139 static DecodeStatus DecodeFPRegsRegisterClass(MCInst &Inst,
140                                               unsigned RegNo,
141                                               uint64_t Address,
142                                               const void *Decoder) {
143   if (RegNo > 31)
144     return MCDisassembler::Fail;
145   unsigned Reg = FPRegDecoderTable[RegNo];
146   Inst.addOperand(MCOperand::CreateReg(Reg));
147   return MCDisassembler::Success;
148 }
149 
150 
151 static DecodeStatus DecodeDFPRegsRegisterClass(MCInst &Inst,
152                                                unsigned RegNo,
153                                                uint64_t Address,
154                                                const void *Decoder) {
155   if (RegNo > 31)
156     return MCDisassembler::Fail;
157   unsigned Reg = DFPRegDecoderTable[RegNo];
158   Inst.addOperand(MCOperand::CreateReg(Reg));
159   return MCDisassembler::Success;
160 }
161 
162 
163 static DecodeStatus DecodeQFPRegsRegisterClass(MCInst &Inst,
164                                                unsigned RegNo,
165                                                uint64_t Address,
166                                                const void *Decoder) {
167   if (RegNo > 31)
168     return MCDisassembler::Fail;
169 
170   unsigned Reg = QFPRegDecoderTable[RegNo];
171   if (Reg == ~0U)
172     return MCDisassembler::Fail;
173   Inst.addOperand(MCOperand::CreateReg(Reg));
174   return MCDisassembler::Success;
175 }
176 
177 static DecodeStatus DecodeLoadInt(MCInst &Inst, unsigned insn, uint64_t Address,
178                                   const void *Decoder);
179 static DecodeStatus DecodeLoadFP(MCInst &Inst, unsigned insn, uint64_t Address,
180                                  const void *Decoder);
181 static DecodeStatus DecodeLoadDFP(MCInst &Inst, unsigned insn, uint64_t Address,
182                                   const void *Decoder);
183 static DecodeStatus DecodeLoadQFP(MCInst &Inst, unsigned insn, uint64_t Address,
184                                   const void *Decoder);
185 static DecodeStatus DecodeStoreInt(MCInst &Inst, unsigned insn,
186                                    uint64_t Address, const void *Decoder);
187 static DecodeStatus DecodeStoreFP(MCInst &Inst, unsigned insn,
188                                   uint64_t Address, const void *Decoder);
189 static DecodeStatus DecodeStoreDFP(MCInst &Inst, unsigned insn,
190                                    uint64_t Address, const void *Decoder);
191 static DecodeStatus DecodeStoreQFP(MCInst &Inst, unsigned insn,
192                                    uint64_t Address, const void *Decoder);
193 static DecodeStatus DecodeCall(MCInst &Inst, unsigned insn,
194                                uint64_t Address, const void *Decoder);
195 static DecodeStatus DecodeSIMM13(MCInst &Inst, unsigned insn,
196                                  uint64_t Address, const void *Decoder);
197 
198 #include "SparcGenDisassemblerTables.inc"
199 
200 /// readInstruction - read four bytes from the MemoryObject
201 /// and return 32 bit word.
202 static DecodeStatus readInstruction32(const MemoryObject &region,
203                                       uint64_t address,
204                                       uint64_t &size,
205                                       uint32_t &insn) {
206   uint8_t Bytes[4];
207 
208   // We want to read exactly 4 Bytes of data.
209   if (region.readBytes(address, 4, Bytes) == -1) {
210     size = 0;
211     return MCDisassembler::Fail;
212   }
213 
214   // Encoded as a big-endian 32-bit word in the stream.
215   insn = (Bytes[3] <<  0) |
216     (Bytes[2] <<  8) |
217     (Bytes[1] << 16) |
218     (Bytes[0] << 24);
219 
220   return MCDisassembler::Success;
221 }
222 
223 
224 DecodeStatus
225 SparcDisassembler::getInstruction(MCInst &instr,
226                                  uint64_t &Size,
227                                  const MemoryObject &Region,
228                                  uint64_t Address,
229                                  raw_ostream &vStream,
230                                  raw_ostream &cStream) const {
231   uint32_t Insn;
232 
233   DecodeStatus Result = readInstruction32(Region, Address, Size, Insn);
234   if (Result == MCDisassembler::Fail)
235     return MCDisassembler::Fail;
236 
237 
238   // Calling the auto-generated decoder function.
239   Result = decodeInstruction(DecoderTableSparc32, instr, Insn, Address,
240                              this, STI);
241 
242   if (Result != MCDisassembler::Fail) {
243     Size = 4;
244     return Result;
245   }
246 
247   return MCDisassembler::Fail;
248 }
249 
250 
251 typedef DecodeStatus (*DecodeFunc)(MCInst &MI, unsigned insn, uint64_t Address,
252                                    const void *Decoder);
253 
254 static DecodeStatus DecodeMem(MCInst &MI, unsigned insn, uint64_t Address,
255                               const void *Decoder,
256                               bool isLoad, DecodeFunc DecodeRD) {
257   unsigned rd = fieldFromInstruction(insn, 25, 5);
258   unsigned rs1 = fieldFromInstruction(insn, 14, 5);
259   bool isImm = fieldFromInstruction(insn, 13, 1);
260   unsigned rs2 = 0;
261   unsigned simm13 = 0;
262   if (isImm)
263     simm13 = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
264   else
265     rs2 = fieldFromInstruction(insn, 0, 5);
266 
267   DecodeStatus status;
268   if (isLoad) {
269     status = DecodeRD(MI, rd, Address, Decoder);
270     if (status != MCDisassembler::Success)
271       return status;
272   }
273 
274   // Decode rs1.
275   status = DecodeIntRegsRegisterClass(MI, rs1, Address, Decoder);
276   if (status != MCDisassembler::Success)
277     return status;
278 
279   // Decode imm|rs2.
280   if (isImm)
281     MI.addOperand(MCOperand::CreateImm(simm13));
282   else {
283     status = DecodeIntRegsRegisterClass(MI, rs2, Address, Decoder);
284     if (status != MCDisassembler::Success)
285       return status;
286   }
287 
288   if (!isLoad) {
289     status = DecodeRD(MI, rd, Address, Decoder);
290     if (status != MCDisassembler::Success)
291       return status;
292   }
293   return MCDisassembler::Success;
294 }
295 
296 static DecodeStatus DecodeLoadInt(MCInst &Inst, unsigned insn, uint64_t Address,
297                                   const void *Decoder) {
298   return DecodeMem(Inst, insn, Address, Decoder, true,
299                    DecodeIntRegsRegisterClass);
300 }
301 
302 static DecodeStatus DecodeLoadFP(MCInst &Inst, unsigned insn, uint64_t Address,
303                                  const void *Decoder) {
304   return DecodeMem(Inst, insn, Address, Decoder, true,
305                    DecodeFPRegsRegisterClass);
306 }
307 
308 static DecodeStatus DecodeLoadDFP(MCInst &Inst, unsigned insn, uint64_t Address,
309                                   const void *Decoder) {
310   return DecodeMem(Inst, insn, Address, Decoder, true,
311                    DecodeDFPRegsRegisterClass);
312 }
313 
314 static DecodeStatus DecodeLoadQFP(MCInst &Inst, unsigned insn, uint64_t Address,
315                                   const void *Decoder) {
316   return DecodeMem(Inst, insn, Address, Decoder, true,
317                    DecodeQFPRegsRegisterClass);
318 }
319 
320 static DecodeStatus DecodeStoreInt(MCInst &Inst, unsigned insn,
321                                    uint64_t Address, const void *Decoder) {
322   return DecodeMem(Inst, insn, Address, Decoder, false,
323                    DecodeIntRegsRegisterClass);
324 }
325 
326 static DecodeStatus DecodeStoreFP(MCInst &Inst, unsigned insn, uint64_t Address,
327                                   const void *Decoder) {
328   return DecodeMem(Inst, insn, Address, Decoder, false,
329                    DecodeFPRegsRegisterClass);
330 }
331 
332 static DecodeStatus DecodeStoreDFP(MCInst &Inst, unsigned insn,
333                                    uint64_t Address, const void *Decoder) {
334   return DecodeMem(Inst, insn, Address, Decoder, false,
335                    DecodeDFPRegsRegisterClass);
336 }
337 
338 static DecodeStatus DecodeStoreQFP(MCInst &Inst, unsigned insn,
339                                    uint64_t Address, const void *Decoder) {
340   return DecodeMem(Inst, insn, Address, Decoder, false,
341                    DecodeQFPRegsRegisterClass);
342 }
343 
344 static bool tryAddingSymbolicOperand(int64_t Value,  bool isBranch,
345                                      uint64_t Address, uint64_t Offset,
346                                      uint64_t Width, MCInst &MI,
347                                      const void *Decoder) {
348   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
349   return Dis->tryAddingSymbolicOperand(MI, Value, Address, isBranch,
350                                        Offset, Width);
351 }
352 
353 static DecodeStatus DecodeCall(MCInst &MI, unsigned insn,
354                                uint64_t Address, const void *Decoder) {
355   unsigned tgt = fieldFromInstruction(insn, 0, 30);
356   tgt <<= 2;
357   if (!tryAddingSymbolicOperand(tgt+Address, false, Address,
358                                 0, 30, MI, Decoder))
359     MI.addOperand(MCOperand::CreateImm(tgt));
360   return MCDisassembler::Success;
361 }
362 
363 static DecodeStatus DecodeSIMM13(MCInst &MI, unsigned insn,
364                                  uint64_t Address, const void *Decoder) {
365   unsigned tgt = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
366   MI.addOperand(MCOperand::CreateImm(tgt));
367   return MCDisassembler::Success;
368 }
369