1 //===- MipsDisassembler.cpp - Disassembler for Mips -------------*- 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 Mips Disassembler.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "Mips.h"
15 #include "MipsRegisterInfo.h"
16 #include "MipsSubtarget.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCDisassembler.h"
19 #include "llvm/MC/MCFixedLenDisassembler.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/MC/MCSubtargetInfo.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/TargetRegistry.h"
24 
25 using namespace llvm;
26 
27 #define DEBUG_TYPE "mips-disassembler"
28 
29 typedef MCDisassembler::DecodeStatus DecodeStatus;
30 
31 namespace {
32 
33 /// A disasembler class for Mips.
34 class MipsDisassemblerBase : public MCDisassembler {
35 public:
36   MipsDisassemblerBase(const MCSubtargetInfo &STI, MCContext &Ctx,
37                        bool IsBigEndian)
38       : MCDisassembler(STI, Ctx),
39         IsGP64Bit(STI.getFeatureBits() & Mips::FeatureGP64Bit),
40         IsBigEndian(IsBigEndian) {}
41 
42   virtual ~MipsDisassemblerBase() {}
43 
44   bool isGP64Bit() const { return IsGP64Bit; }
45 
46 private:
47   bool IsGP64Bit;
48 protected:
49   bool IsBigEndian;
50 };
51 
52 /// A disasembler class for Mips32.
53 class MipsDisassembler : public MipsDisassemblerBase {
54   bool IsMicroMips;
55 public:
56   MipsDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx, bool bigEndian)
57       : MipsDisassemblerBase(STI, Ctx, bigEndian) {
58     IsMicroMips = STI.getFeatureBits() & Mips::FeatureMicroMips;
59   }
60 
61   bool hasMips3() const { return STI.getFeatureBits() & Mips::FeatureMips3; }
62   bool hasMips32() const { return STI.getFeatureBits() & Mips::FeatureMips32; }
63   bool hasMips32r6() const {
64     return STI.getFeatureBits() & Mips::FeatureMips32r6;
65   }
66 
67   bool isGP64() const { return STI.getFeatureBits() & Mips::FeatureGP64Bit; }
68 
69   bool hasCOP3() const {
70     // Only present in MIPS-I and MIPS-II
71     return !hasMips32() && !hasMips3();
72   }
73 
74   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
75                               ArrayRef<uint8_t> Bytes, uint64_t Address,
76                               raw_ostream &VStream,
77                               raw_ostream &CStream) const override;
78 };
79 
80 /// A disasembler class for Mips64.
81 class Mips64Disassembler : public MipsDisassemblerBase {
82 public:
83   Mips64Disassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
84                      bool bigEndian) :
85     MipsDisassemblerBase(STI, Ctx, bigEndian) {}
86 
87   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
88                               ArrayRef<uint8_t> Bytes, uint64_t Address,
89                               raw_ostream &VStream,
90                               raw_ostream &CStream) const override;
91 };
92 
93 } // end anonymous namespace
94 
95 // Forward declare these because the autogenerated code will reference them.
96 // Definitions are further down.
97 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
98                                              unsigned RegNo,
99                                              uint64_t Address,
100                                              const void *Decoder);
101 
102 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
103                                                  unsigned RegNo,
104                                                  uint64_t Address,
105                                                  const void *Decoder);
106 
107 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
108                                                unsigned RegNo,
109                                                uint64_t Address,
110                                                const void *Decoder);
111 
112 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
113                                                    unsigned RegNo,
114                                                    uint64_t Address,
115                                                    const void *Decoder);
116 
117 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
118                                              unsigned RegNo,
119                                              uint64_t Address,
120                                              const void *Decoder);
121 
122 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
123                                            unsigned Insn,
124                                            uint64_t Address,
125                                            const void *Decoder);
126 
127 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
128                                             unsigned RegNo,
129                                             uint64_t Address,
130                                             const void *Decoder);
131 
132 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
133                                              unsigned RegNo,
134                                              uint64_t Address,
135                                              const void *Decoder);
136 
137 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
138                                              unsigned RegNo,
139                                              uint64_t Address,
140                                              const void *Decoder);
141 
142 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
143                                            unsigned RegNo,
144                                            uint64_t Address,
145                                            const void *Decoder);
146 
147 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
148                                            unsigned RegNo,
149                                            uint64_t Address,
150                                            const void *Decoder);
151 
152 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
153                                              uint64_t Address,
154                                              const void *Decoder);
155 
156 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
157                                               unsigned Insn,
158                                               uint64_t Address,
159                                               const void *Decoder);
160 
161 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
162                                               unsigned RegNo,
163                                               uint64_t Address,
164                                               const void *Decoder);
165 
166 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
167                                                 unsigned RegNo,
168                                                 uint64_t Address,
169                                                 const void *Decoder);
170 
171 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
172                                                unsigned RegNo,
173                                                uint64_t Address,
174                                                const void *Decoder);
175 
176 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
177                                                unsigned RegNo,
178                                                uint64_t Address,
179                                                const void *Decoder);
180 
181 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
182                                                unsigned RegNo,
183                                                uint64_t Address,
184                                                const void *Decoder);
185 
186 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
187                                                unsigned RegNo,
188                                                uint64_t Address,
189                                                const void *Decoder);
190 
191 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
192                                                unsigned RegNo,
193                                                uint64_t Address,
194                                                const void *Decoder);
195 
196 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
197                                                unsigned RegNo,
198                                                uint64_t Address,
199                                                const void *Decoder);
200 
201 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
202                                                unsigned RegNo,
203                                                uint64_t Address,
204                                                const void *Decoder);
205 
206 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
207                                             unsigned RegNo,
208                                             uint64_t Address,
209                                             const void *Decoder);
210 
211 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
212                                        unsigned Offset,
213                                        uint64_t Address,
214                                        const void *Decoder);
215 
216 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
217                                      unsigned Insn,
218                                      uint64_t Address,
219                                      const void *Decoder);
220 
221 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
222                                          unsigned Offset,
223                                          uint64_t Address,
224                                          const void *Decoder);
225 
226 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
227                                          unsigned Offset,
228                                          uint64_t Address,
229                                          const void *Decoder);
230 
231 // DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
232 // shifted left by 1 bit.
233 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
234                                           unsigned Offset,
235                                           uint64_t Address,
236                                           const void *Decoder);
237 
238 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
239 // shifted left by 1 bit.
240 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
241                                          unsigned Offset,
242                                          uint64_t Address,
243                                          const void *Decoder);
244 
245 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
246 // shifted left by 1 bit.
247 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
248                                        unsigned Insn,
249                                        uint64_t Address,
250                                        const void *Decoder);
251 
252 static DecodeStatus DecodeMem(MCInst &Inst,
253                               unsigned Insn,
254                               uint64_t Address,
255                               const void *Decoder);
256 
257 static DecodeStatus DecodeCacheOp(MCInst &Inst,
258                               unsigned Insn,
259                               uint64_t Address,
260                               const void *Decoder);
261 
262 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
263                                     unsigned Insn,
264                                     uint64_t Address,
265                                     const void *Decoder);
266 
267 static DecodeStatus DecodeSyncI(MCInst &Inst,
268                                 unsigned Insn,
269                                 uint64_t Address,
270                                 const void *Decoder);
271 
272 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
273                                     uint64_t Address, const void *Decoder);
274 
275 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
276                                     unsigned Insn,
277                                     uint64_t Address,
278                                     const void *Decoder);
279 
280 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
281                                           unsigned Insn,
282                                           uint64_t Address,
283                                           const void *Decoder);
284 
285 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
286                                      unsigned Insn,
287                                      uint64_t Address,
288                                      const void *Decoder);
289 
290 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
291                                      unsigned Insn,
292                                      uint64_t Address,
293                                      const void *Decoder);
294 
295 static DecodeStatus DecodeFMem(MCInst &Inst, unsigned Insn,
296                                uint64_t Address,
297                                const void *Decoder);
298 
299 static DecodeStatus DecodeFMem2(MCInst &Inst, unsigned Insn,
300                                uint64_t Address,
301                                const void *Decoder);
302 
303 static DecodeStatus DecodeFMem3(MCInst &Inst, unsigned Insn,
304                                uint64_t Address,
305                                const void *Decoder);
306 
307 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
308                                        unsigned Insn,
309                                        uint64_t Address,
310                                        const void *Decoder);
311 
312 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
313                                        unsigned Value,
314                                        uint64_t Address,
315                                        const void *Decoder);
316 
317 static DecodeStatus DecodeUImm6Lsl2(MCInst &Inst,
318                                     unsigned Value,
319                                     uint64_t Address,
320                                     const void *Decoder);
321 
322 static DecodeStatus DecodeLiSimm7(MCInst &Inst,
323                                   unsigned Value,
324                                   uint64_t Address,
325                                   const void *Decoder);
326 
327 static DecodeStatus DecodeSimm4(MCInst &Inst,
328                                 unsigned Value,
329                                 uint64_t Address,
330                                 const void *Decoder);
331 
332 static DecodeStatus DecodeSimm16(MCInst &Inst,
333                                  unsigned Insn,
334                                  uint64_t Address,
335                                  const void *Decoder);
336 
337 // Decode the immediate field of an LSA instruction which
338 // is off by one.
339 static DecodeStatus DecodeLSAImm(MCInst &Inst,
340                                  unsigned Insn,
341                                  uint64_t Address,
342                                  const void *Decoder);
343 
344 static DecodeStatus DecodeInsSize(MCInst &Inst,
345                                   unsigned Insn,
346                                   uint64_t Address,
347                                   const void *Decoder);
348 
349 static DecodeStatus DecodeExtSize(MCInst &Inst,
350                                   unsigned Insn,
351                                   uint64_t Address,
352                                   const void *Decoder);
353 
354 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
355                                      uint64_t Address, const void *Decoder);
356 
357 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
358                                      uint64_t Address, const void *Decoder);
359 
360 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
361                                   uint64_t Address, const void *Decoder);
362 
363 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
364                                     uint64_t Address, const void *Decoder);
365 
366 static DecodeStatus DecodeUImm5lsl2(MCInst &Inst, unsigned Insn,
367                                    uint64_t Address, const void *Decoder);
368 
369 /// INSVE_[BHWD] have an implicit operand that the generated decoder doesn't
370 /// handle.
371 template <typename InsnType>
372 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
373                                    const void *Decoder);
374 
375 template <typename InsnType>
376 static DecodeStatus
377 DecodeAddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
378                       const void *Decoder);
379 
380 template <typename InsnType>
381 static DecodeStatus
382 DecodeDaddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
383                        const void *Decoder);
384 
385 template <typename InsnType>
386 static DecodeStatus
387 DecodeBlezlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
388                        const void *Decoder);
389 
390 template <typename InsnType>
391 static DecodeStatus
392 DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
393                        const void *Decoder);
394 
395 template <typename InsnType>
396 static DecodeStatus
397 DecodeBgtzGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
398                       const void *Decoder);
399 
400 template <typename InsnType>
401 static DecodeStatus
402 DecodeBlezGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
403                        const void *Decoder);
404 
405 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
406                                          uint64_t Address,
407                                          const void *Decoder);
408 
409 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
410                                            uint64_t Address,
411                                            const void *Decoder);
412 
413 namespace llvm {
414 extern Target TheMipselTarget, TheMipsTarget, TheMips64Target,
415               TheMips64elTarget;
416 }
417 
418 static MCDisassembler *createMipsDisassembler(
419                        const Target &T,
420                        const MCSubtargetInfo &STI,
421                        MCContext &Ctx) {
422   return new MipsDisassembler(STI, Ctx, true);
423 }
424 
425 static MCDisassembler *createMipselDisassembler(
426                        const Target &T,
427                        const MCSubtargetInfo &STI,
428                        MCContext &Ctx) {
429   return new MipsDisassembler(STI, Ctx, false);
430 }
431 
432 static MCDisassembler *createMips64Disassembler(
433                        const Target &T,
434                        const MCSubtargetInfo &STI,
435                        MCContext &Ctx) {
436   return new Mips64Disassembler(STI, Ctx, true);
437 }
438 
439 static MCDisassembler *createMips64elDisassembler(
440                        const Target &T,
441                        const MCSubtargetInfo &STI,
442                        MCContext &Ctx) {
443   return new Mips64Disassembler(STI, Ctx, false);
444 }
445 
446 extern "C" void LLVMInitializeMipsDisassembler() {
447   // Register the disassembler.
448   TargetRegistry::RegisterMCDisassembler(TheMipsTarget,
449                                          createMipsDisassembler);
450   TargetRegistry::RegisterMCDisassembler(TheMipselTarget,
451                                          createMipselDisassembler);
452   TargetRegistry::RegisterMCDisassembler(TheMips64Target,
453                                          createMips64Disassembler);
454   TargetRegistry::RegisterMCDisassembler(TheMips64elTarget,
455                                          createMips64elDisassembler);
456 }
457 
458 #include "MipsGenDisassemblerTables.inc"
459 
460 static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) {
461   const MipsDisassemblerBase *Dis = static_cast<const MipsDisassemblerBase*>(D);
462   const MCRegisterInfo *RegInfo = Dis->getContext().getRegisterInfo();
463   return *(RegInfo->getRegClass(RC).begin() + RegNo);
464 }
465 
466 template <typename InsnType>
467 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
468                                    const void *Decoder) {
469   typedef DecodeStatus (*DecodeFN)(MCInst &, unsigned, uint64_t, const void *);
470   // The size of the n field depends on the element size
471   // The register class also depends on this.
472   InsnType tmp = fieldFromInstruction(insn, 17, 5);
473   unsigned NSize = 0;
474   DecodeFN RegDecoder = nullptr;
475   if ((tmp & 0x18) == 0x00) { // INSVE_B
476     NSize = 4;
477     RegDecoder = DecodeMSA128BRegisterClass;
478   } else if ((tmp & 0x1c) == 0x10) { // INSVE_H
479     NSize = 3;
480     RegDecoder = DecodeMSA128HRegisterClass;
481   } else if ((tmp & 0x1e) == 0x18) { // INSVE_W
482     NSize = 2;
483     RegDecoder = DecodeMSA128WRegisterClass;
484   } else if ((tmp & 0x1f) == 0x1c) { // INSVE_D
485     NSize = 1;
486     RegDecoder = DecodeMSA128DRegisterClass;
487   } else
488     llvm_unreachable("Invalid encoding");
489 
490   assert(NSize != 0 && RegDecoder != nullptr);
491 
492   // $wd
493   tmp = fieldFromInstruction(insn, 6, 5);
494   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
495     return MCDisassembler::Fail;
496   // $wd_in
497   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
498     return MCDisassembler::Fail;
499   // $n
500   tmp = fieldFromInstruction(insn, 16, NSize);
501   MI.addOperand(MCOperand::CreateImm(tmp));
502   // $ws
503   tmp = fieldFromInstruction(insn, 11, 5);
504   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
505     return MCDisassembler::Fail;
506   // $n2
507   MI.addOperand(MCOperand::CreateImm(0));
508 
509   return MCDisassembler::Success;
510 }
511 
512 template <typename InsnType>
513 static DecodeStatus DecodeAddiGroupBranch(MCInst &MI, InsnType insn,
514                                           uint64_t Address,
515                                           const void *Decoder) {
516   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
517   // (otherwise we would have matched the ADDI instruction from the earlier
518   // ISA's instead).
519   //
520   // We have:
521   //    0b001000 sssss ttttt iiiiiiiiiiiiiiii
522   //      BOVC if rs >= rt
523   //      BEQZALC if rs == 0 && rt != 0
524   //      BEQC if rs < rt && rs != 0
525 
526   InsnType Rs = fieldFromInstruction(insn, 21, 5);
527   InsnType Rt = fieldFromInstruction(insn, 16, 5);
528   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
529   bool HasRs = false;
530 
531   if (Rs >= Rt) {
532     MI.setOpcode(Mips::BOVC);
533     HasRs = true;
534   } else if (Rs != 0 && Rs < Rt) {
535     MI.setOpcode(Mips::BEQC);
536     HasRs = true;
537   } else
538     MI.setOpcode(Mips::BEQZALC);
539 
540   if (HasRs)
541     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
542                                        Rs)));
543 
544   MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
545                                      Rt)));
546   MI.addOperand(MCOperand::CreateImm(Imm));
547 
548   return MCDisassembler::Success;
549 }
550 
551 template <typename InsnType>
552 static DecodeStatus DecodeDaddiGroupBranch(MCInst &MI, InsnType insn,
553                                            uint64_t Address,
554                                            const void *Decoder) {
555   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
556   // (otherwise we would have matched the ADDI instruction from the earlier
557   // ISA's instead).
558   //
559   // We have:
560   //    0b011000 sssss ttttt iiiiiiiiiiiiiiii
561   //      BNVC if rs >= rt
562   //      BNEZALC if rs == 0 && rt != 0
563   //      BNEC if rs < rt && rs != 0
564 
565   InsnType Rs = fieldFromInstruction(insn, 21, 5);
566   InsnType Rt = fieldFromInstruction(insn, 16, 5);
567   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
568   bool HasRs = false;
569 
570   if (Rs >= Rt) {
571     MI.setOpcode(Mips::BNVC);
572     HasRs = true;
573   } else if (Rs != 0 && Rs < Rt) {
574     MI.setOpcode(Mips::BNEC);
575     HasRs = true;
576   } else
577     MI.setOpcode(Mips::BNEZALC);
578 
579   if (HasRs)
580     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
581                                        Rs)));
582 
583   MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
584                                      Rt)));
585   MI.addOperand(MCOperand::CreateImm(Imm));
586 
587   return MCDisassembler::Success;
588 }
589 
590 template <typename InsnType>
591 static DecodeStatus DecodeBlezlGroupBranch(MCInst &MI, InsnType insn,
592                                            uint64_t Address,
593                                            const void *Decoder) {
594   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
595   // (otherwise we would have matched the BLEZL instruction from the earlier
596   // ISA's instead).
597   //
598   // We have:
599   //    0b010110 sssss ttttt iiiiiiiiiiiiiiii
600   //      Invalid if rs == 0
601   //      BLEZC   if rs == 0  && rt != 0
602   //      BGEZC   if rs == rt && rt != 0
603   //      BGEC    if rs != rt && rs != 0  && rt != 0
604 
605   InsnType Rs = fieldFromInstruction(insn, 21, 5);
606   InsnType Rt = fieldFromInstruction(insn, 16, 5);
607   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
608   bool HasRs = false;
609 
610   if (Rt == 0)
611     return MCDisassembler::Fail;
612   else if (Rs == 0)
613     MI.setOpcode(Mips::BLEZC);
614   else if (Rs == Rt)
615     MI.setOpcode(Mips::BGEZC);
616   else {
617     HasRs = true;
618     MI.setOpcode(Mips::BGEC);
619   }
620 
621   if (HasRs)
622     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
623                                        Rs)));
624 
625   MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
626                                      Rt)));
627 
628   MI.addOperand(MCOperand::CreateImm(Imm));
629 
630   return MCDisassembler::Success;
631 }
632 
633 template <typename InsnType>
634 static DecodeStatus DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn,
635                                            uint64_t Address,
636                                            const void *Decoder) {
637   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
638   // (otherwise we would have matched the BGTZL instruction from the earlier
639   // ISA's instead).
640   //
641   // We have:
642   //    0b010111 sssss ttttt iiiiiiiiiiiiiiii
643   //      Invalid if rs == 0
644   //      BGTZC   if rs == 0  && rt != 0
645   //      BLTZC   if rs == rt && rt != 0
646   //      BLTC    if rs != rt && rs != 0  && rt != 0
647 
648   bool HasRs = false;
649 
650   InsnType Rs = fieldFromInstruction(insn, 21, 5);
651   InsnType Rt = fieldFromInstruction(insn, 16, 5);
652   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
653 
654   if (Rt == 0)
655     return MCDisassembler::Fail;
656   else if (Rs == 0)
657     MI.setOpcode(Mips::BGTZC);
658   else if (Rs == Rt)
659     MI.setOpcode(Mips::BLTZC);
660   else {
661     MI.setOpcode(Mips::BLTC);
662     HasRs = true;
663   }
664 
665   if (HasRs)
666     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
667                                               Rs)));
668 
669   MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
670                                      Rt)));
671 
672   MI.addOperand(MCOperand::CreateImm(Imm));
673 
674   return MCDisassembler::Success;
675 }
676 
677 template <typename InsnType>
678 static DecodeStatus DecodeBgtzGroupBranch(MCInst &MI, InsnType insn,
679                                           uint64_t Address,
680                                           const void *Decoder) {
681   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
682   // (otherwise we would have matched the BGTZ instruction from the earlier
683   // ISA's instead).
684   //
685   // We have:
686   //    0b000111 sssss ttttt iiiiiiiiiiiiiiii
687   //      BGTZ    if rt == 0
688   //      BGTZALC if rs == 0 && rt != 0
689   //      BLTZALC if rs != 0 && rs == rt
690   //      BLTUC   if rs != 0 && rs != rt
691 
692   InsnType Rs = fieldFromInstruction(insn, 21, 5);
693   InsnType Rt = fieldFromInstruction(insn, 16, 5);
694   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
695   bool HasRs = false;
696   bool HasRt = false;
697 
698   if (Rt == 0) {
699     MI.setOpcode(Mips::BGTZ);
700     HasRs = true;
701   } else if (Rs == 0) {
702     MI.setOpcode(Mips::BGTZALC);
703     HasRt = true;
704   } else if (Rs == Rt) {
705     MI.setOpcode(Mips::BLTZALC);
706     HasRs = true;
707   } else {
708     MI.setOpcode(Mips::BLTUC);
709     HasRs = true;
710     HasRt = true;
711   }
712 
713   if (HasRs)
714     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
715                                        Rs)));
716 
717   if (HasRt)
718     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
719                                        Rt)));
720 
721   MI.addOperand(MCOperand::CreateImm(Imm));
722 
723   return MCDisassembler::Success;
724 }
725 
726 template <typename InsnType>
727 static DecodeStatus DecodeBlezGroupBranch(MCInst &MI, InsnType insn,
728                                            uint64_t Address,
729                                            const void *Decoder) {
730   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
731   // (otherwise we would have matched the BLEZL instruction from the earlier
732   // ISA's instead).
733   //
734   // We have:
735   //    0b000110 sssss ttttt iiiiiiiiiiiiiiii
736   //      Invalid   if rs == 0
737   //      BLEZALC   if rs == 0  && rt != 0
738   //      BGEZALC   if rs == rt && rt != 0
739   //      BGEUC     if rs != rt && rs != 0  && rt != 0
740 
741   InsnType Rs = fieldFromInstruction(insn, 21, 5);
742   InsnType Rt = fieldFromInstruction(insn, 16, 5);
743   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
744   bool HasRs = false;
745 
746   if (Rt == 0)
747     return MCDisassembler::Fail;
748   else if (Rs == 0)
749     MI.setOpcode(Mips::BLEZALC);
750   else if (Rs == Rt)
751     MI.setOpcode(Mips::BGEZALC);
752   else {
753     HasRs = true;
754     MI.setOpcode(Mips::BGEUC);
755   }
756 
757   if (HasRs)
758     MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
759                                        Rs)));
760   MI.addOperand(MCOperand::CreateReg(getReg(Decoder, Mips::GPR32RegClassID,
761                                      Rt)));
762 
763   MI.addOperand(MCOperand::CreateImm(Imm));
764 
765   return MCDisassembler::Success;
766 }
767 
768 /// Read two bytes from the ArrayRef and return 16 bit halfword sorted
769 /// according to the given endianess.
770 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
771                                       uint64_t &Size, uint32_t &Insn,
772                                       bool IsBigEndian) {
773   // We want to read exactly 2 Bytes of data.
774   if (Bytes.size() < 2) {
775     Size = 0;
776     return MCDisassembler::Fail;
777   }
778 
779   if (IsBigEndian) {
780     Insn = (Bytes[0] << 8) | Bytes[1];
781   } else {
782     Insn = (Bytes[1] << 8) | Bytes[0];
783   }
784 
785   return MCDisassembler::Success;
786 }
787 
788 /// Read four bytes from the ArrayRef and return 32 bit word sorted
789 /// according to the given endianess
790 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
791                                       uint64_t &Size, uint32_t &Insn,
792                                       bool IsBigEndian, bool IsMicroMips) {
793   // We want to read exactly 4 Bytes of data.
794   if (Bytes.size() < 4) {
795     Size = 0;
796     return MCDisassembler::Fail;
797   }
798 
799   // High 16 bits of a 32-bit microMIPS instruction (where the opcode is)
800   // always precede the low 16 bits in the instruction stream (that is, they
801   // are placed at lower addresses in the instruction stream).
802   //
803   // microMIPS byte ordering:
804   //   Big-endian:    0 | 1 | 2 | 3
805   //   Little-endian: 1 | 0 | 3 | 2
806 
807   if (IsBigEndian) {
808     // Encoded as a big-endian 32-bit word in the stream.
809     Insn =
810         (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) | (Bytes[0] << 24);
811   } else {
812     if (IsMicroMips) {
813       Insn = (Bytes[2] << 0) | (Bytes[3] << 8) | (Bytes[0] << 16) |
814              (Bytes[1] << 24);
815     } else {
816       Insn = (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
817              (Bytes[3] << 24);
818     }
819   }
820 
821   return MCDisassembler::Success;
822 }
823 
824 DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
825                                               ArrayRef<uint8_t> Bytes,
826                                               uint64_t Address,
827                                               raw_ostream &VStream,
828                                               raw_ostream &CStream) const {
829   uint32_t Insn;
830   DecodeStatus Result;
831 
832   if (IsMicroMips) {
833     Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian);
834 
835     DEBUG(dbgs() << "Trying MicroMips16 table (16-bit instructions):\n");
836     // Calling the auto-generated decoder function.
837     Result = decodeInstruction(DecoderTableMicroMips16, Instr, Insn, Address,
838                                this, STI);
839     if (Result != MCDisassembler::Fail) {
840       Size = 2;
841       return Result;
842     }
843 
844     Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, true);
845     if (Result == MCDisassembler::Fail)
846       return MCDisassembler::Fail;
847 
848     DEBUG(dbgs() << "Trying MicroMips32 table (32-bit instructions):\n");
849     // Calling the auto-generated decoder function.
850     Result = decodeInstruction(DecoderTableMicroMips32, Instr, Insn, Address,
851                                this, STI);
852     if (Result != MCDisassembler::Fail) {
853       Size = 4;
854       return Result;
855     }
856     return MCDisassembler::Fail;
857   }
858 
859   Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
860   if (Result == MCDisassembler::Fail)
861     return MCDisassembler::Fail;
862 
863   if (hasCOP3()) {
864     DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n");
865     Result =
866         decodeInstruction(DecoderTableCOP3_32, Instr, Insn, Address, this, STI);
867     if (Result != MCDisassembler::Fail) {
868       Size = 4;
869       return Result;
870     }
871   }
872 
873   if (hasMips32r6() && isGP64()) {
874     DEBUG(dbgs() << "Trying Mips32r6_64r6 (GPR64) table (32-bit opcodes):\n");
875     Result = decodeInstruction(DecoderTableMips32r6_64r6_GP6432, Instr, Insn,
876                                Address, this, STI);
877     if (Result != MCDisassembler::Fail) {
878       Size = 4;
879       return Result;
880     }
881   }
882 
883   if (hasMips32r6()) {
884     DEBUG(dbgs() << "Trying Mips32r6_64r6 table (32-bit opcodes):\n");
885     Result = decodeInstruction(DecoderTableMips32r6_64r632, Instr, Insn,
886                                Address, this, STI);
887     if (Result != MCDisassembler::Fail) {
888       Size = 4;
889       return Result;
890     }
891   }
892 
893   DEBUG(dbgs() << "Trying Mips table (32-bit opcodes):\n");
894   // Calling the auto-generated decoder function.
895   Result =
896       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
897   if (Result != MCDisassembler::Fail) {
898     Size = 4;
899     return Result;
900   }
901 
902   return MCDisassembler::Fail;
903 }
904 
905 DecodeStatus Mips64Disassembler::getInstruction(MCInst &Instr, uint64_t &Size,
906                                                 ArrayRef<uint8_t> Bytes,
907                                                 uint64_t Address,
908                                                 raw_ostream &VStream,
909                                                 raw_ostream &CStream) const {
910   uint32_t Insn;
911 
912   DecodeStatus Result =
913       readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
914   if (Result == MCDisassembler::Fail)
915     return MCDisassembler::Fail;
916 
917   // Calling the auto-generated decoder function.
918   Result =
919       decodeInstruction(DecoderTableMips6432, Instr, Insn, Address, this, STI);
920   if (Result != MCDisassembler::Fail) {
921     Size = 4;
922     return Result;
923   }
924   // If we fail to decode in Mips64 decoder space we can try in Mips32
925   Result =
926       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
927   if (Result != MCDisassembler::Fail) {
928     Size = 4;
929     return Result;
930   }
931 
932   return MCDisassembler::Fail;
933 }
934 
935 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
936                                                  unsigned RegNo,
937                                                  uint64_t Address,
938                                                  const void *Decoder) {
939 
940   return MCDisassembler::Fail;
941 
942 }
943 
944 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
945                                              unsigned RegNo,
946                                              uint64_t Address,
947                                              const void *Decoder) {
948 
949   if (RegNo > 31)
950     return MCDisassembler::Fail;
951 
952   unsigned Reg = getReg(Decoder, Mips::GPR64RegClassID, RegNo);
953   Inst.addOperand(MCOperand::CreateReg(Reg));
954   return MCDisassembler::Success;
955 }
956 
957 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
958                                                unsigned RegNo,
959                                                uint64_t Address,
960                                                const void *Decoder) {
961   if (RegNo > 7)
962     return MCDisassembler::Fail;
963   unsigned Reg = getReg(Decoder, Mips::GPRMM16RegClassID, RegNo);
964   Inst.addOperand(MCOperand::CreateReg(Reg));
965   return MCDisassembler::Success;
966 }
967 
968 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
969                                                    unsigned RegNo,
970                                                    uint64_t Address,
971                                                    const void *Decoder) {
972   if (RegNo > 7)
973     return MCDisassembler::Fail;
974   unsigned Reg = getReg(Decoder, Mips::GPRMM16ZeroRegClassID, RegNo);
975   Inst.addOperand(MCOperand::CreateReg(Reg));
976   return MCDisassembler::Success;
977 }
978 
979 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
980                                              unsigned RegNo,
981                                              uint64_t Address,
982                                              const void *Decoder) {
983   if (RegNo > 31)
984     return MCDisassembler::Fail;
985   unsigned Reg = getReg(Decoder, Mips::GPR32RegClassID, RegNo);
986   Inst.addOperand(MCOperand::CreateReg(Reg));
987   return MCDisassembler::Success;
988 }
989 
990 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
991                                            unsigned RegNo,
992                                            uint64_t Address,
993                                            const void *Decoder) {
994   if (static_cast<const MipsDisassembler *>(Decoder)->isGP64Bit())
995     return DecodeGPR64RegisterClass(Inst, RegNo, Address, Decoder);
996 
997   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
998 }
999 
1000 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
1001                                             unsigned RegNo,
1002                                             uint64_t Address,
1003                                             const void *Decoder) {
1004   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1005 }
1006 
1007 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
1008                                              unsigned RegNo,
1009                                              uint64_t Address,
1010                                              const void *Decoder) {
1011   if (RegNo > 31)
1012     return MCDisassembler::Fail;
1013 
1014   unsigned Reg = getReg(Decoder, Mips::FGR64RegClassID, RegNo);
1015   Inst.addOperand(MCOperand::CreateReg(Reg));
1016   return MCDisassembler::Success;
1017 }
1018 
1019 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
1020                                              unsigned RegNo,
1021                                              uint64_t Address,
1022                                              const void *Decoder) {
1023   if (RegNo > 31)
1024     return MCDisassembler::Fail;
1025 
1026   unsigned Reg = getReg(Decoder, Mips::FGR32RegClassID, RegNo);
1027   Inst.addOperand(MCOperand::CreateReg(Reg));
1028   return MCDisassembler::Success;
1029 }
1030 
1031 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
1032                                            unsigned RegNo,
1033                                            uint64_t Address,
1034                                            const void *Decoder) {
1035   if (RegNo > 31)
1036     return MCDisassembler::Fail;
1037   unsigned Reg = getReg(Decoder, Mips::CCRRegClassID, RegNo);
1038   Inst.addOperand(MCOperand::CreateReg(Reg));
1039   return MCDisassembler::Success;
1040 }
1041 
1042 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
1043                                            unsigned RegNo,
1044                                            uint64_t Address,
1045                                            const void *Decoder) {
1046   if (RegNo > 7)
1047     return MCDisassembler::Fail;
1048   unsigned Reg = getReg(Decoder, Mips::FCCRegClassID, RegNo);
1049   Inst.addOperand(MCOperand::CreateReg(Reg));
1050   return MCDisassembler::Success;
1051 }
1052 
1053 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
1054                                              uint64_t Address,
1055                                              const void *Decoder) {
1056   if (RegNo > 31)
1057     return MCDisassembler::Fail;
1058 
1059   unsigned Reg = getReg(Decoder, Mips::FGRCCRegClassID, RegNo);
1060   Inst.addOperand(MCOperand::CreateReg(Reg));
1061   return MCDisassembler::Success;
1062 }
1063 
1064 static DecodeStatus DecodeMem(MCInst &Inst,
1065                               unsigned Insn,
1066                               uint64_t Address,
1067                               const void *Decoder) {
1068   int Offset = SignExtend32<16>(Insn & 0xffff);
1069   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1070   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1071 
1072   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1073   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1074 
1075   if(Inst.getOpcode() == Mips::SC ||
1076      Inst.getOpcode() == Mips::SCD){
1077     Inst.addOperand(MCOperand::CreateReg(Reg));
1078   }
1079 
1080   Inst.addOperand(MCOperand::CreateReg(Reg));
1081   Inst.addOperand(MCOperand::CreateReg(Base));
1082   Inst.addOperand(MCOperand::CreateImm(Offset));
1083 
1084   return MCDisassembler::Success;
1085 }
1086 
1087 static DecodeStatus DecodeCacheOp(MCInst &Inst,
1088                               unsigned Insn,
1089                               uint64_t Address,
1090                               const void *Decoder) {
1091   int Offset = SignExtend32<16>(Insn & 0xffff);
1092   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1093   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1094 
1095   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1096 
1097   Inst.addOperand(MCOperand::CreateReg(Base));
1098   Inst.addOperand(MCOperand::CreateImm(Offset));
1099   Inst.addOperand(MCOperand::CreateImm(Hint));
1100 
1101   return MCDisassembler::Success;
1102 }
1103 
1104 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
1105                                     unsigned Insn,
1106                                     uint64_t Address,
1107                                     const void *Decoder) {
1108   int Offset = SignExtend32<12>(Insn & 0xfff);
1109   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1110   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1111 
1112   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1113 
1114   Inst.addOperand(MCOperand::CreateReg(Base));
1115   Inst.addOperand(MCOperand::CreateImm(Offset));
1116   Inst.addOperand(MCOperand::CreateImm(Hint));
1117 
1118   return MCDisassembler::Success;
1119 }
1120 
1121 static DecodeStatus DecodeSyncI(MCInst &Inst,
1122                               unsigned Insn,
1123                               uint64_t Address,
1124                               const void *Decoder) {
1125   int Offset = SignExtend32<16>(Insn & 0xffff);
1126   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1127 
1128   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1129 
1130   Inst.addOperand(MCOperand::CreateReg(Base));
1131   Inst.addOperand(MCOperand::CreateImm(Offset));
1132 
1133   return MCDisassembler::Success;
1134 }
1135 
1136 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
1137                                     uint64_t Address, const void *Decoder) {
1138   int Offset = SignExtend32<10>(fieldFromInstruction(Insn, 16, 10));
1139   unsigned Reg = fieldFromInstruction(Insn, 6, 5);
1140   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1141 
1142   Reg = getReg(Decoder, Mips::MSA128BRegClassID, Reg);
1143   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1144 
1145   Inst.addOperand(MCOperand::CreateReg(Reg));
1146   Inst.addOperand(MCOperand::CreateReg(Base));
1147 
1148   // The immediate field of an LD/ST instruction is scaled which means it must
1149   // be multiplied (when decoding) by the size (in bytes) of the instructions'
1150   // data format.
1151   // .b - 1 byte
1152   // .h - 2 bytes
1153   // .w - 4 bytes
1154   // .d - 8 bytes
1155   switch(Inst.getOpcode())
1156   {
1157   default:
1158     assert (0 && "Unexpected instruction");
1159     return MCDisassembler::Fail;
1160     break;
1161   case Mips::LD_B:
1162   case Mips::ST_B:
1163     Inst.addOperand(MCOperand::CreateImm(Offset));
1164     break;
1165   case Mips::LD_H:
1166   case Mips::ST_H:
1167     Inst.addOperand(MCOperand::CreateImm(Offset * 2));
1168     break;
1169   case Mips::LD_W:
1170   case Mips::ST_W:
1171     Inst.addOperand(MCOperand::CreateImm(Offset * 4));
1172     break;
1173   case Mips::LD_D:
1174   case Mips::ST_D:
1175     Inst.addOperand(MCOperand::CreateImm(Offset * 8));
1176     break;
1177   }
1178 
1179   return MCDisassembler::Success;
1180 }
1181 
1182 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
1183                                     unsigned Insn,
1184                                     uint64_t Address,
1185                                     const void *Decoder) {
1186   unsigned Offset = Insn & 0xf;
1187   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1188   unsigned Base = fieldFromInstruction(Insn, 4, 3);
1189 
1190   switch (Inst.getOpcode()) {
1191     case Mips::LBU16_MM:
1192     case Mips::LHU16_MM:
1193     case Mips::LW16_MM:
1194       if (DecodeGPRMM16RegisterClass(Inst, Reg, Address, Decoder)
1195             == MCDisassembler::Fail)
1196         return MCDisassembler::Fail;
1197       break;
1198     case Mips::SB16_MM:
1199     case Mips::SH16_MM:
1200     case Mips::SW16_MM:
1201       if (DecodeGPRMM16ZeroRegisterClass(Inst, Reg, Address, Decoder)
1202             == MCDisassembler::Fail)
1203         return MCDisassembler::Fail;
1204       break;
1205   }
1206 
1207   if (DecodeGPRMM16RegisterClass(Inst, Base, Address, Decoder)
1208         == MCDisassembler::Fail)
1209     return MCDisassembler::Fail;
1210 
1211   switch (Inst.getOpcode()) {
1212     case Mips::LBU16_MM:
1213       if (Offset == 0xf)
1214         Inst.addOperand(MCOperand::CreateImm(-1));
1215       else
1216         Inst.addOperand(MCOperand::CreateImm(Offset));
1217       break;
1218     case Mips::SB16_MM:
1219       Inst.addOperand(MCOperand::CreateImm(Offset));
1220       break;
1221     case Mips::LHU16_MM:
1222     case Mips::SH16_MM:
1223       Inst.addOperand(MCOperand::CreateImm(Offset << 1));
1224       break;
1225     case Mips::LW16_MM:
1226     case Mips::SW16_MM:
1227       Inst.addOperand(MCOperand::CreateImm(Offset << 2));
1228       break;
1229   }
1230 
1231   return MCDisassembler::Success;
1232 }
1233 
1234 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
1235                                           unsigned Insn,
1236                                           uint64_t Address,
1237                                           const void *Decoder) {
1238   unsigned Offset = Insn & 0x1F;
1239   unsigned Reg = fieldFromInstruction(Insn, 5, 5);
1240 
1241   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1242 
1243   Inst.addOperand(MCOperand::CreateReg(Reg));
1244   Inst.addOperand(MCOperand::CreateReg(Mips::SP));
1245   Inst.addOperand(MCOperand::CreateImm(Offset << 2));
1246 
1247   return MCDisassembler::Success;
1248 }
1249 
1250 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
1251                                      unsigned Insn,
1252                                      uint64_t Address,
1253                                      const void *Decoder) {
1254   int Offset = SignExtend32<12>(Insn & 0x0fff);
1255   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1256   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1257 
1258   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1259   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1260 
1261   switch (Inst.getOpcode()) {
1262   case Mips::SWM32_MM:
1263   case Mips::LWM32_MM:
1264     if (DecodeRegListOperand(Inst, Insn, Address, Decoder)
1265         == MCDisassembler::Fail)
1266       return MCDisassembler::Fail;
1267     Inst.addOperand(MCOperand::CreateReg(Base));
1268     Inst.addOperand(MCOperand::CreateImm(Offset));
1269     break;
1270   case Mips::SC_MM:
1271     Inst.addOperand(MCOperand::CreateReg(Reg));
1272     // fallthrough
1273   default:
1274     Inst.addOperand(MCOperand::CreateReg(Reg));
1275     if (Inst.getOpcode() == Mips::LWP_MM || Inst.getOpcode() == Mips::SWP_MM)
1276       Inst.addOperand(MCOperand::CreateReg(Reg+1));
1277 
1278     Inst.addOperand(MCOperand::CreateReg(Base));
1279     Inst.addOperand(MCOperand::CreateImm(Offset));
1280   }
1281 
1282   return MCDisassembler::Success;
1283 }
1284 
1285 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
1286                                      unsigned Insn,
1287                                      uint64_t Address,
1288                                      const void *Decoder) {
1289   int Offset = SignExtend32<16>(Insn & 0xffff);
1290   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1291   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1292 
1293   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1294   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1295 
1296   Inst.addOperand(MCOperand::CreateReg(Reg));
1297   Inst.addOperand(MCOperand::CreateReg(Base));
1298   Inst.addOperand(MCOperand::CreateImm(Offset));
1299 
1300   return MCDisassembler::Success;
1301 }
1302 
1303 static DecodeStatus DecodeFMem(MCInst &Inst,
1304                                unsigned Insn,
1305                                uint64_t Address,
1306                                const void *Decoder) {
1307   int Offset = SignExtend32<16>(Insn & 0xffff);
1308   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1309   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1310 
1311   Reg = getReg(Decoder, Mips::FGR64RegClassID, Reg);
1312   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1313 
1314   Inst.addOperand(MCOperand::CreateReg(Reg));
1315   Inst.addOperand(MCOperand::CreateReg(Base));
1316   Inst.addOperand(MCOperand::CreateImm(Offset));
1317 
1318   return MCDisassembler::Success;
1319 }
1320 
1321 static DecodeStatus DecodeFMem2(MCInst &Inst,
1322                                unsigned Insn,
1323                                uint64_t Address,
1324                                const void *Decoder) {
1325   int Offset = SignExtend32<16>(Insn & 0xffff);
1326   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1327   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1328 
1329   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1330   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1331 
1332   Inst.addOperand(MCOperand::CreateReg(Reg));
1333   Inst.addOperand(MCOperand::CreateReg(Base));
1334   Inst.addOperand(MCOperand::CreateImm(Offset));
1335 
1336   return MCDisassembler::Success;
1337 }
1338 
1339 static DecodeStatus DecodeFMem3(MCInst &Inst,
1340                                unsigned Insn,
1341                                uint64_t Address,
1342                                const void *Decoder) {
1343   int Offset = SignExtend32<16>(Insn & 0xffff);
1344   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1345   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1346 
1347   Reg = getReg(Decoder, Mips::COP3RegClassID, Reg);
1348   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1349 
1350   Inst.addOperand(MCOperand::CreateReg(Reg));
1351   Inst.addOperand(MCOperand::CreateReg(Base));
1352   Inst.addOperand(MCOperand::CreateImm(Offset));
1353 
1354   return MCDisassembler::Success;
1355 }
1356 
1357 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
1358                                        unsigned Insn,
1359                                        uint64_t Address,
1360                                        const void *Decoder) {
1361   int64_t Offset = SignExtend64<9>((Insn >> 7) & 0x1ff);
1362   unsigned Rt = fieldFromInstruction(Insn, 16, 5);
1363   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1364 
1365   Rt = getReg(Decoder, Mips::GPR32RegClassID, Rt);
1366   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1367 
1368   if(Inst.getOpcode() == Mips::SC_R6 || Inst.getOpcode() == Mips::SCD_R6){
1369     Inst.addOperand(MCOperand::CreateReg(Rt));
1370   }
1371 
1372   Inst.addOperand(MCOperand::CreateReg(Rt));
1373   Inst.addOperand(MCOperand::CreateReg(Base));
1374   Inst.addOperand(MCOperand::CreateImm(Offset));
1375 
1376   return MCDisassembler::Success;
1377 }
1378 
1379 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
1380                                               unsigned RegNo,
1381                                               uint64_t Address,
1382                                               const void *Decoder) {
1383   // Currently only hardware register 29 is supported.
1384   if (RegNo != 29)
1385     return  MCDisassembler::Fail;
1386   Inst.addOperand(MCOperand::CreateReg(Mips::HWR29));
1387   return MCDisassembler::Success;
1388 }
1389 
1390 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
1391                                               unsigned RegNo,
1392                                               uint64_t Address,
1393                                               const void *Decoder) {
1394   if (RegNo > 30 || RegNo %2)
1395     return MCDisassembler::Fail;
1396 
1397   ;
1398   unsigned Reg = getReg(Decoder, Mips::AFGR64RegClassID, RegNo /2);
1399   Inst.addOperand(MCOperand::CreateReg(Reg));
1400   return MCDisassembler::Success;
1401 }
1402 
1403 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
1404                                                 unsigned RegNo,
1405                                                 uint64_t Address,
1406                                                 const void *Decoder) {
1407   if (RegNo >= 4)
1408     return MCDisassembler::Fail;
1409 
1410   unsigned Reg = getReg(Decoder, Mips::ACC64DSPRegClassID, RegNo);
1411   Inst.addOperand(MCOperand::CreateReg(Reg));
1412   return MCDisassembler::Success;
1413 }
1414 
1415 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
1416                                                unsigned RegNo,
1417                                                uint64_t Address,
1418                                                const void *Decoder) {
1419   if (RegNo >= 4)
1420     return MCDisassembler::Fail;
1421 
1422   unsigned Reg = getReg(Decoder, Mips::HI32DSPRegClassID, RegNo);
1423   Inst.addOperand(MCOperand::CreateReg(Reg));
1424   return MCDisassembler::Success;
1425 }
1426 
1427 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
1428                                                unsigned RegNo,
1429                                                uint64_t Address,
1430                                                const void *Decoder) {
1431   if (RegNo >= 4)
1432     return MCDisassembler::Fail;
1433 
1434   unsigned Reg = getReg(Decoder, Mips::LO32DSPRegClassID, RegNo);
1435   Inst.addOperand(MCOperand::CreateReg(Reg));
1436   return MCDisassembler::Success;
1437 }
1438 
1439 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
1440                                                unsigned RegNo,
1441                                                uint64_t Address,
1442                                                const void *Decoder) {
1443   if (RegNo > 31)
1444     return MCDisassembler::Fail;
1445 
1446   unsigned Reg = getReg(Decoder, Mips::MSA128BRegClassID, RegNo);
1447   Inst.addOperand(MCOperand::CreateReg(Reg));
1448   return MCDisassembler::Success;
1449 }
1450 
1451 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
1452                                                unsigned RegNo,
1453                                                uint64_t Address,
1454                                                const void *Decoder) {
1455   if (RegNo > 31)
1456     return MCDisassembler::Fail;
1457 
1458   unsigned Reg = getReg(Decoder, Mips::MSA128HRegClassID, RegNo);
1459   Inst.addOperand(MCOperand::CreateReg(Reg));
1460   return MCDisassembler::Success;
1461 }
1462 
1463 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
1464                                                unsigned RegNo,
1465                                                uint64_t Address,
1466                                                const void *Decoder) {
1467   if (RegNo > 31)
1468     return MCDisassembler::Fail;
1469 
1470   unsigned Reg = getReg(Decoder, Mips::MSA128WRegClassID, RegNo);
1471   Inst.addOperand(MCOperand::CreateReg(Reg));
1472   return MCDisassembler::Success;
1473 }
1474 
1475 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
1476                                                unsigned RegNo,
1477                                                uint64_t Address,
1478                                                const void *Decoder) {
1479   if (RegNo > 31)
1480     return MCDisassembler::Fail;
1481 
1482   unsigned Reg = getReg(Decoder, Mips::MSA128DRegClassID, RegNo);
1483   Inst.addOperand(MCOperand::CreateReg(Reg));
1484   return MCDisassembler::Success;
1485 }
1486 
1487 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
1488                                                unsigned RegNo,
1489                                                uint64_t Address,
1490                                                const void *Decoder) {
1491   if (RegNo > 7)
1492     return MCDisassembler::Fail;
1493 
1494   unsigned Reg = getReg(Decoder, Mips::MSACtrlRegClassID, RegNo);
1495   Inst.addOperand(MCOperand::CreateReg(Reg));
1496   return MCDisassembler::Success;
1497 }
1498 
1499 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
1500                                             unsigned RegNo,
1501                                             uint64_t Address,
1502                                             const void *Decoder) {
1503   if (RegNo > 31)
1504     return MCDisassembler::Fail;
1505 
1506   unsigned Reg = getReg(Decoder, Mips::COP2RegClassID, RegNo);
1507   Inst.addOperand(MCOperand::CreateReg(Reg));
1508   return MCDisassembler::Success;
1509 }
1510 
1511 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
1512                                        unsigned Offset,
1513                                        uint64_t Address,
1514                                        const void *Decoder) {
1515   int32_t BranchOffset = (SignExtend32<16>(Offset) * 4) + 4;
1516   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
1517   return MCDisassembler::Success;
1518 }
1519 
1520 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
1521                                      unsigned Insn,
1522                                      uint64_t Address,
1523                                      const void *Decoder) {
1524 
1525   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
1526   Inst.addOperand(MCOperand::CreateImm(JumpOffset));
1527   return MCDisassembler::Success;
1528 }
1529 
1530 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
1531                                          unsigned Offset,
1532                                          uint64_t Address,
1533                                          const void *Decoder) {
1534   int32_t BranchOffset = SignExtend32<21>(Offset) * 4;
1535 
1536   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
1537   return MCDisassembler::Success;
1538 }
1539 
1540 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
1541                                          unsigned Offset,
1542                                          uint64_t Address,
1543                                          const void *Decoder) {
1544   int32_t BranchOffset = SignExtend32<26>(Offset) * 4;
1545 
1546   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
1547   return MCDisassembler::Success;
1548 }
1549 
1550 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
1551                                           unsigned Offset,
1552                                           uint64_t Address,
1553                                           const void *Decoder) {
1554   int32_t BranchOffset = SignExtend32<7>(Offset) << 1;
1555   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
1556   return MCDisassembler::Success;
1557 }
1558 
1559 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
1560                                          unsigned Offset,
1561                                          uint64_t Address,
1562                                          const void *Decoder) {
1563   int32_t BranchOffset = SignExtend32<16>(Offset) * 2;
1564   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
1565   return MCDisassembler::Success;
1566 }
1567 
1568 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
1569                                        unsigned Insn,
1570                                        uint64_t Address,
1571                                        const void *Decoder) {
1572   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 1;
1573   Inst.addOperand(MCOperand::CreateImm(JumpOffset));
1574   return MCDisassembler::Success;
1575 }
1576 
1577 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
1578                                        unsigned Value,
1579                                        uint64_t Address,
1580                                        const void *Decoder) {
1581   if (Value == 0)
1582     Inst.addOperand(MCOperand::CreateImm(1));
1583   else if (Value == 0x7)
1584     Inst.addOperand(MCOperand::CreateImm(-1));
1585   else
1586     Inst.addOperand(MCOperand::CreateImm(Value << 2));
1587   return MCDisassembler::Success;
1588 }
1589 
1590 static DecodeStatus DecodeUImm6Lsl2(MCInst &Inst,
1591                                     unsigned Value,
1592                                     uint64_t Address,
1593                                     const void *Decoder) {
1594   Inst.addOperand(MCOperand::CreateImm(Value << 2));
1595   return MCDisassembler::Success;
1596 }
1597 
1598 static DecodeStatus DecodeLiSimm7(MCInst &Inst,
1599                                   unsigned Value,
1600                                   uint64_t Address,
1601                                   const void *Decoder) {
1602   if (Value == 0x7F)
1603     Inst.addOperand(MCOperand::CreateImm(-1));
1604   else
1605     Inst.addOperand(MCOperand::CreateImm(Value));
1606   return MCDisassembler::Success;
1607 }
1608 
1609 static DecodeStatus DecodeSimm4(MCInst &Inst,
1610                                 unsigned Value,
1611                                 uint64_t Address,
1612                                 const void *Decoder) {
1613   Inst.addOperand(MCOperand::CreateImm(SignExtend32<4>(Value)));
1614   return MCDisassembler::Success;
1615 }
1616 
1617 static DecodeStatus DecodeSimm16(MCInst &Inst,
1618                                  unsigned Insn,
1619                                  uint64_t Address,
1620                                  const void *Decoder) {
1621   Inst.addOperand(MCOperand::CreateImm(SignExtend32<16>(Insn)));
1622   return MCDisassembler::Success;
1623 }
1624 
1625 static DecodeStatus DecodeLSAImm(MCInst &Inst,
1626                                  unsigned Insn,
1627                                  uint64_t Address,
1628                                  const void *Decoder) {
1629   // We add one to the immediate field as it was encoded as 'imm - 1'.
1630   Inst.addOperand(MCOperand::CreateImm(Insn + 1));
1631   return MCDisassembler::Success;
1632 }
1633 
1634 static DecodeStatus DecodeInsSize(MCInst &Inst,
1635                                   unsigned Insn,
1636                                   uint64_t Address,
1637                                   const void *Decoder) {
1638   // First we need to grab the pos(lsb) from MCInst.
1639   int Pos = Inst.getOperand(2).getImm();
1640   int Size = (int) Insn - Pos + 1;
1641   Inst.addOperand(MCOperand::CreateImm(SignExtend32<16>(Size)));
1642   return MCDisassembler::Success;
1643 }
1644 
1645 static DecodeStatus DecodeExtSize(MCInst &Inst,
1646                                   unsigned Insn,
1647                                   uint64_t Address,
1648                                   const void *Decoder) {
1649   int Size = (int) Insn  + 1;
1650   Inst.addOperand(MCOperand::CreateImm(SignExtend32<16>(Size)));
1651   return MCDisassembler::Success;
1652 }
1653 
1654 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
1655                                      uint64_t Address, const void *Decoder) {
1656   Inst.addOperand(MCOperand::CreateImm(SignExtend32<19>(Insn) * 4));
1657   return MCDisassembler::Success;
1658 }
1659 
1660 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
1661                                      uint64_t Address, const void *Decoder) {
1662   Inst.addOperand(MCOperand::CreateImm(SignExtend32<18>(Insn) * 8));
1663   return MCDisassembler::Success;
1664 }
1665 
1666 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
1667                                   uint64_t Address, const void *Decoder) {
1668   int32_t DecodedValue;
1669   switch (Insn) {
1670   case 0: DecodedValue = 256; break;
1671   case 1: DecodedValue = 257; break;
1672   case 510: DecodedValue = -258; break;
1673   case 511: DecodedValue = -257; break;
1674   default: DecodedValue = SignExtend32<9>(Insn); break;
1675   }
1676   Inst.addOperand(MCOperand::CreateImm(DecodedValue * 4));
1677   return MCDisassembler::Success;
1678 }
1679 
1680 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
1681                                     uint64_t Address, const void *Decoder) {
1682   // Insn must be >= 0, since it is unsigned that condition is always true.
1683   assert(Insn < 16);
1684   int32_t DecodedValues[] = {128, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64,
1685                              255, 32768, 65535};
1686   Inst.addOperand(MCOperand::CreateImm(DecodedValues[Insn]));
1687   return MCDisassembler::Success;
1688 }
1689 
1690 static DecodeStatus DecodeUImm5lsl2(MCInst &Inst, unsigned Insn,
1691                                     uint64_t Address, const void *Decoder) {
1692   Inst.addOperand(MCOperand::CreateImm(Insn << 2));
1693   return MCDisassembler::Success;
1694 }
1695 
1696 static DecodeStatus DecodeRegListOperand(MCInst &Inst,
1697                                          unsigned Insn,
1698                                          uint64_t Address,
1699                                          const void *Decoder) {
1700   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5,
1701                      Mips::S6, Mips::FP};
1702   unsigned RegNum;
1703 
1704   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
1705   // Empty register lists are not allowed.
1706   if (RegLst == 0)
1707     return MCDisassembler::Fail;
1708 
1709   RegNum = RegLst & 0xf;
1710   for (unsigned i = 0; i < RegNum; i++)
1711     Inst.addOperand(MCOperand::CreateReg(Regs[i]));
1712 
1713   if (RegLst & 0x10)
1714     Inst.addOperand(MCOperand::CreateReg(Mips::RA));
1715 
1716   return MCDisassembler::Success;
1717 }
1718 
1719 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
1720                                            uint64_t Address,
1721                                            const void *Decoder) {
1722   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
1723   unsigned RegNum;
1724 
1725   unsigned RegLst = fieldFromInstruction(Insn, 4, 2);
1726   // Empty register lists are not allowed.
1727   if (RegLst == 0)
1728     return MCDisassembler::Fail;
1729 
1730   RegNum = RegLst & 0x3;
1731   for (unsigned i = 0; i < RegNum - 1; i++)
1732     Inst.addOperand(MCOperand::CreateReg(Regs[i]));
1733 
1734   Inst.addOperand(MCOperand::CreateReg(Mips::RA));
1735 
1736   return MCDisassembler::Success;
1737 }
1738