xref: /llvm-project/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp (revision f703132b09a2b5a53461f2b220e2f8e548d46c47)
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 const unsigned FCCRegDecoderTable[] = {
117   SP::FCC0, SP::FCC1, SP::FCC2, SP::FCC3 };
118 
119 static DecodeStatus DecodeIntRegsRegisterClass(MCInst &Inst,
120                                                unsigned RegNo,
121                                                uint64_t Address,
122                                                const void *Decoder) {
123   if (RegNo > 31)
124     return MCDisassembler::Fail;
125   unsigned Reg = IntRegDecoderTable[RegNo];
126   Inst.addOperand(MCOperand::CreateReg(Reg));
127   return MCDisassembler::Success;
128 }
129 
130 static DecodeStatus DecodeI64RegsRegisterClass(MCInst &Inst,
131                                                unsigned RegNo,
132                                                uint64_t Address,
133                                                const void *Decoder) {
134   if (RegNo > 31)
135     return MCDisassembler::Fail;
136   unsigned Reg = IntRegDecoderTable[RegNo];
137   Inst.addOperand(MCOperand::CreateReg(Reg));
138   return MCDisassembler::Success;
139 }
140 
141 
142 static DecodeStatus DecodeFPRegsRegisterClass(MCInst &Inst,
143                                               unsigned RegNo,
144                                               uint64_t Address,
145                                               const void *Decoder) {
146   if (RegNo > 31)
147     return MCDisassembler::Fail;
148   unsigned Reg = FPRegDecoderTable[RegNo];
149   Inst.addOperand(MCOperand::CreateReg(Reg));
150   return MCDisassembler::Success;
151 }
152 
153 
154 static DecodeStatus DecodeDFPRegsRegisterClass(MCInst &Inst,
155                                                unsigned RegNo,
156                                                uint64_t Address,
157                                                const void *Decoder) {
158   if (RegNo > 31)
159     return MCDisassembler::Fail;
160   unsigned Reg = DFPRegDecoderTable[RegNo];
161   Inst.addOperand(MCOperand::CreateReg(Reg));
162   return MCDisassembler::Success;
163 }
164 
165 
166 static DecodeStatus DecodeQFPRegsRegisterClass(MCInst &Inst,
167                                                unsigned RegNo,
168                                                uint64_t Address,
169                                                const void *Decoder) {
170   if (RegNo > 31)
171     return MCDisassembler::Fail;
172 
173   unsigned Reg = QFPRegDecoderTable[RegNo];
174   if (Reg == ~0U)
175     return MCDisassembler::Fail;
176   Inst.addOperand(MCOperand::CreateReg(Reg));
177   return MCDisassembler::Success;
178 }
179 
180 static DecodeStatus DecodeFCCRegsRegisterClass(MCInst &Inst, unsigned RegNo,
181                                                uint64_t Address,
182                                                const void *Decoder) {
183   if (RegNo > 3)
184     return MCDisassembler::Fail;
185   Inst.addOperand(MCOperand::CreateReg(FCCRegDecoderTable[RegNo]));
186   return MCDisassembler::Success;
187 }
188 
189 
190 static DecodeStatus DecodeLoadInt(MCInst &Inst, unsigned insn, uint64_t Address,
191                                   const void *Decoder);
192 static DecodeStatus DecodeLoadFP(MCInst &Inst, unsigned insn, uint64_t Address,
193                                  const void *Decoder);
194 static DecodeStatus DecodeLoadDFP(MCInst &Inst, unsigned insn, uint64_t Address,
195                                   const void *Decoder);
196 static DecodeStatus DecodeLoadQFP(MCInst &Inst, unsigned insn, uint64_t Address,
197                                   const void *Decoder);
198 static DecodeStatus DecodeStoreInt(MCInst &Inst, unsigned insn,
199                                    uint64_t Address, const void *Decoder);
200 static DecodeStatus DecodeStoreFP(MCInst &Inst, unsigned insn,
201                                   uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeStoreDFP(MCInst &Inst, unsigned insn,
203                                    uint64_t Address, const void *Decoder);
204 static DecodeStatus DecodeStoreQFP(MCInst &Inst, unsigned insn,
205                                    uint64_t Address, const void *Decoder);
206 static DecodeStatus DecodeCall(MCInst &Inst, unsigned insn,
207                                uint64_t Address, const void *Decoder);
208 static DecodeStatus DecodeSIMM13(MCInst &Inst, unsigned insn,
209                                  uint64_t Address, const void *Decoder);
210 static DecodeStatus DecodeJMPL(MCInst &Inst, unsigned insn, uint64_t Address,
211                                const void *Decoder);
212 static DecodeStatus DecodeReturn(MCInst &MI, unsigned insn, uint64_t Address,
213                                  const void *Decoder);
214 static DecodeStatus DecodeSWAP(MCInst &Inst, unsigned insn, uint64_t Address,
215                                const void *Decoder);
216 
217 #include "SparcGenDisassemblerTables.inc"
218 
219 /// readInstruction - read four bytes from the MemoryObject
220 /// and return 32 bit word.
221 static DecodeStatus readInstruction32(const MemoryObject &region,
222                                       uint64_t address,
223                                       uint64_t &size,
224                                       uint32_t &insn) {
225   uint8_t Bytes[4];
226 
227   // We want to read exactly 4 Bytes of data.
228   if (region.readBytes(address, 4, Bytes) == -1) {
229     size = 0;
230     return MCDisassembler::Fail;
231   }
232 
233   // Encoded as a big-endian 32-bit word in the stream.
234   insn = (Bytes[3] <<  0) |
235     (Bytes[2] <<  8) |
236     (Bytes[1] << 16) |
237     (Bytes[0] << 24);
238 
239   return MCDisassembler::Success;
240 }
241 
242 
243 DecodeStatus
244 SparcDisassembler::getInstruction(MCInst &instr,
245                                  uint64_t &Size,
246                                  const MemoryObject &Region,
247                                  uint64_t Address,
248                                  raw_ostream &vStream,
249                                  raw_ostream &cStream) const {
250   uint32_t Insn;
251 
252   DecodeStatus Result = readInstruction32(Region, Address, Size, Insn);
253   if (Result == MCDisassembler::Fail)
254     return MCDisassembler::Fail;
255 
256 
257   // Calling the auto-generated decoder function.
258   Result = decodeInstruction(DecoderTableSparc32, instr, Insn, Address,
259                              this, STI);
260 
261   if (Result != MCDisassembler::Fail) {
262     Size = 4;
263     return Result;
264   }
265 
266   return MCDisassembler::Fail;
267 }
268 
269 
270 typedef DecodeStatus (*DecodeFunc)(MCInst &MI, unsigned insn, uint64_t Address,
271                                    const void *Decoder);
272 
273 static DecodeStatus DecodeMem(MCInst &MI, unsigned insn, uint64_t Address,
274                               const void *Decoder,
275                               bool isLoad, DecodeFunc DecodeRD) {
276   unsigned rd = fieldFromInstruction(insn, 25, 5);
277   unsigned rs1 = fieldFromInstruction(insn, 14, 5);
278   bool isImm = fieldFromInstruction(insn, 13, 1);
279   unsigned rs2 = 0;
280   unsigned simm13 = 0;
281   if (isImm)
282     simm13 = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
283   else
284     rs2 = fieldFromInstruction(insn, 0, 5);
285 
286   DecodeStatus status;
287   if (isLoad) {
288     status = DecodeRD(MI, rd, Address, Decoder);
289     if (status != MCDisassembler::Success)
290       return status;
291   }
292 
293   // Decode rs1.
294   status = DecodeIntRegsRegisterClass(MI, rs1, Address, Decoder);
295   if (status != MCDisassembler::Success)
296     return status;
297 
298   // Decode imm|rs2.
299   if (isImm)
300     MI.addOperand(MCOperand::CreateImm(simm13));
301   else {
302     status = DecodeIntRegsRegisterClass(MI, rs2, Address, Decoder);
303     if (status != MCDisassembler::Success)
304       return status;
305   }
306 
307   if (!isLoad) {
308     status = DecodeRD(MI, rd, Address, Decoder);
309     if (status != MCDisassembler::Success)
310       return status;
311   }
312   return MCDisassembler::Success;
313 }
314 
315 static DecodeStatus DecodeLoadInt(MCInst &Inst, unsigned insn, uint64_t Address,
316                                   const void *Decoder) {
317   return DecodeMem(Inst, insn, Address, Decoder, true,
318                    DecodeIntRegsRegisterClass);
319 }
320 
321 static DecodeStatus DecodeLoadFP(MCInst &Inst, unsigned insn, uint64_t Address,
322                                  const void *Decoder) {
323   return DecodeMem(Inst, insn, Address, Decoder, true,
324                    DecodeFPRegsRegisterClass);
325 }
326 
327 static DecodeStatus DecodeLoadDFP(MCInst &Inst, unsigned insn, uint64_t Address,
328                                   const void *Decoder) {
329   return DecodeMem(Inst, insn, Address, Decoder, true,
330                    DecodeDFPRegsRegisterClass);
331 }
332 
333 static DecodeStatus DecodeLoadQFP(MCInst &Inst, unsigned insn, uint64_t Address,
334                                   const void *Decoder) {
335   return DecodeMem(Inst, insn, Address, Decoder, true,
336                    DecodeQFPRegsRegisterClass);
337 }
338 
339 static DecodeStatus DecodeStoreInt(MCInst &Inst, unsigned insn,
340                                    uint64_t Address, const void *Decoder) {
341   return DecodeMem(Inst, insn, Address, Decoder, false,
342                    DecodeIntRegsRegisterClass);
343 }
344 
345 static DecodeStatus DecodeStoreFP(MCInst &Inst, unsigned insn, uint64_t Address,
346                                   const void *Decoder) {
347   return DecodeMem(Inst, insn, Address, Decoder, false,
348                    DecodeFPRegsRegisterClass);
349 }
350 
351 static DecodeStatus DecodeStoreDFP(MCInst &Inst, unsigned insn,
352                                    uint64_t Address, const void *Decoder) {
353   return DecodeMem(Inst, insn, Address, Decoder, false,
354                    DecodeDFPRegsRegisterClass);
355 }
356 
357 static DecodeStatus DecodeStoreQFP(MCInst &Inst, unsigned insn,
358                                    uint64_t Address, const void *Decoder) {
359   return DecodeMem(Inst, insn, Address, Decoder, false,
360                    DecodeQFPRegsRegisterClass);
361 }
362 
363 static bool tryAddingSymbolicOperand(int64_t Value,  bool isBranch,
364                                      uint64_t Address, uint64_t Offset,
365                                      uint64_t Width, MCInst &MI,
366                                      const void *Decoder) {
367   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
368   return Dis->tryAddingSymbolicOperand(MI, Value, Address, isBranch,
369                                        Offset, Width);
370 }
371 
372 static DecodeStatus DecodeCall(MCInst &MI, unsigned insn,
373                                uint64_t Address, const void *Decoder) {
374   unsigned tgt = fieldFromInstruction(insn, 0, 30);
375   tgt <<= 2;
376   if (!tryAddingSymbolicOperand(tgt+Address, false, Address,
377                                 0, 30, MI, Decoder))
378     MI.addOperand(MCOperand::CreateImm(tgt));
379   return MCDisassembler::Success;
380 }
381 
382 static DecodeStatus DecodeSIMM13(MCInst &MI, unsigned insn,
383                                  uint64_t Address, const void *Decoder) {
384   unsigned tgt = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
385   MI.addOperand(MCOperand::CreateImm(tgt));
386   return MCDisassembler::Success;
387 }
388 
389 static DecodeStatus DecodeJMPL(MCInst &MI, unsigned insn, uint64_t Address,
390                                const void *Decoder) {
391 
392   unsigned rd = fieldFromInstruction(insn, 25, 5);
393   unsigned rs1 = fieldFromInstruction(insn, 14, 5);
394   unsigned isImm = fieldFromInstruction(insn, 13, 1);
395   unsigned rs2 = 0;
396   unsigned simm13 = 0;
397   if (isImm)
398     simm13 = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
399   else
400     rs2 = fieldFromInstruction(insn, 0, 5);
401 
402   // Decode RD.
403   DecodeStatus status = DecodeIntRegsRegisterClass(MI, rd, Address, Decoder);
404   if (status != MCDisassembler::Success)
405     return status;
406 
407   // Decode RS1.
408   status = DecodeIntRegsRegisterClass(MI, rs1, Address, Decoder);
409   if (status != MCDisassembler::Success)
410     return status;
411 
412   // Decode RS1 | SIMM13.
413   if (isImm)
414     MI.addOperand(MCOperand::CreateImm(simm13));
415   else {
416     status = DecodeIntRegsRegisterClass(MI, rs2, Address, Decoder);
417     if (status != MCDisassembler::Success)
418       return status;
419   }
420   return MCDisassembler::Success;
421 }
422 
423 static DecodeStatus DecodeReturn(MCInst &MI, unsigned insn, uint64_t Address,
424                                  const void *Decoder) {
425 
426   unsigned rs1 = fieldFromInstruction(insn, 14, 5);
427   unsigned isImm = fieldFromInstruction(insn, 13, 1);
428   unsigned rs2 = 0;
429   unsigned simm13 = 0;
430   if (isImm)
431     simm13 = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
432   else
433     rs2 = fieldFromInstruction(insn, 0, 5);
434 
435   // Decode RS1.
436   DecodeStatus status = DecodeIntRegsRegisterClass(MI, rs1, Address, Decoder);
437   if (status != MCDisassembler::Success)
438     return status;
439 
440   // Decode RS2 | SIMM13.
441   if (isImm)
442     MI.addOperand(MCOperand::CreateImm(simm13));
443   else {
444     status = DecodeIntRegsRegisterClass(MI, rs2, Address, Decoder);
445     if (status != MCDisassembler::Success)
446       return status;
447   }
448   return MCDisassembler::Success;
449 }
450 
451 static DecodeStatus DecodeSWAP(MCInst &MI, unsigned insn, uint64_t Address,
452                                const void *Decoder) {
453 
454   unsigned rd = fieldFromInstruction(insn, 25, 5);
455   unsigned rs1 = fieldFromInstruction(insn, 14, 5);
456   unsigned isImm = fieldFromInstruction(insn, 13, 1);
457   unsigned rs2 = 0;
458   unsigned simm13 = 0;
459   if (isImm)
460     simm13 = SignExtend32<13>(fieldFromInstruction(insn, 0, 13));
461   else
462     rs2 = fieldFromInstruction(insn, 0, 5);
463 
464   // Decode RD.
465   DecodeStatus status = DecodeIntRegsRegisterClass(MI, rd, Address, Decoder);
466   if (status != MCDisassembler::Success)
467     return status;
468 
469   // Decode RS1.
470   status = DecodeIntRegsRegisterClass(MI, rs1, Address, Decoder);
471   if (status != MCDisassembler::Success)
472     return status;
473 
474   // Decode RS1 | SIMM13.
475   if (isImm)
476     MI.addOperand(MCOperand::CreateImm(simm13));
477   else {
478     status = DecodeIntRegsRegisterClass(MI, rs2, Address, Decoder);
479     if (status != MCDisassembler::Success)
480       return status;
481   }
482   return MCDisassembler::Success;
483 }
484