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/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 class MipsDisassembler : public MCDisassembler {
34   bool IsMicroMips;
35   bool IsBigEndian;
36 public:
37   MipsDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx, bool IsBigEndian)
38       : MCDisassembler(STI, Ctx),
39         IsMicroMips(STI.getFeatureBits()[Mips::FeatureMicroMips]),
40         IsBigEndian(IsBigEndian) {}
41 
42   bool hasMips3() const { return STI.getFeatureBits()[Mips::FeatureMips3]; }
43   bool hasMips32() const { return STI.getFeatureBits()[Mips::FeatureMips32]; }
44   bool hasMips32r6() const {
45     return STI.getFeatureBits()[Mips::FeatureMips32r6];
46   }
47   bool isFP64() const { return STI.getFeatureBits()[Mips::FeatureFP64Bit]; }
48 
49   bool isGP64() const { return STI.getFeatureBits()[Mips::FeatureGP64Bit]; }
50 
51   bool hasCnMips() const { return STI.getFeatureBits()[Mips::FeatureCnMips]; }
52 
53   bool hasCOP3() const {
54     // Only present in MIPS-I and MIPS-II
55     return !hasMips32() && !hasMips3();
56   }
57 
58   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
59                               ArrayRef<uint8_t> Bytes, uint64_t Address,
60                               raw_ostream &VStream,
61                               raw_ostream &CStream) const override;
62 };
63 
64 } // end anonymous namespace
65 
66 // Forward declare these because the autogenerated code will reference them.
67 // Definitions are further down.
68 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
69                                              unsigned RegNo,
70                                              uint64_t Address,
71                                              const void *Decoder);
72 
73 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
74                                                  unsigned RegNo,
75                                                  uint64_t Address,
76                                                  const void *Decoder);
77 
78 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
79                                                unsigned RegNo,
80                                                uint64_t Address,
81                                                const void *Decoder);
82 
83 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
84                                                    unsigned RegNo,
85                                                    uint64_t Address,
86                                                    const void *Decoder);
87 
88 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
89                                                     unsigned RegNo,
90                                                     uint64_t Address,
91                                                     const void *Decoder);
92 
93 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
94                                              unsigned RegNo,
95                                              uint64_t Address,
96                                              const void *Decoder);
97 
98 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
99                                            unsigned Insn,
100                                            uint64_t Address,
101                                            const void *Decoder);
102 
103 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
104                                             unsigned RegNo,
105                                             uint64_t Address,
106                                             const void *Decoder);
107 
108 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
109                                              unsigned RegNo,
110                                              uint64_t Address,
111                                              const void *Decoder);
112 
113 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
114                                              unsigned RegNo,
115                                              uint64_t Address,
116                                              const void *Decoder);
117 
118 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
119                                            unsigned RegNo,
120                                            uint64_t Address,
121                                            const void *Decoder);
122 
123 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
124                                            unsigned RegNo,
125                                            uint64_t Address,
126                                            const void *Decoder);
127 
128 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
129                                              uint64_t Address,
130                                              const void *Decoder);
131 
132 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
133                                               unsigned Insn,
134                                               uint64_t Address,
135                                               const void *Decoder);
136 
137 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
138                                               unsigned RegNo,
139                                               uint64_t Address,
140                                               const void *Decoder);
141 
142 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
143                                                 unsigned RegNo,
144                                                 uint64_t Address,
145                                                 const void *Decoder);
146 
147 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
148                                                unsigned RegNo,
149                                                uint64_t Address,
150                                                const void *Decoder);
151 
152 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
153                                                unsigned RegNo,
154                                                uint64_t Address,
155                                                const void *Decoder);
156 
157 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
158                                                unsigned RegNo,
159                                                uint64_t Address,
160                                                const void *Decoder);
161 
162 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
163                                                unsigned RegNo,
164                                                uint64_t Address,
165                                                const void *Decoder);
166 
167 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
168                                                unsigned RegNo,
169                                                uint64_t Address,
170                                                const void *Decoder);
171 
172 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
173                                                unsigned RegNo,
174                                                uint64_t Address,
175                                                const void *Decoder);
176 
177 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
178                                                unsigned RegNo,
179                                                uint64_t Address,
180                                                const void *Decoder);
181 
182 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
183                                             unsigned RegNo,
184                                             uint64_t Address,
185                                             const void *Decoder);
186 
187 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
188                                             unsigned RegNo,
189                                             uint64_t Address,
190                                             const void *Decoder);
191 
192 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
193                                        unsigned Offset,
194                                        uint64_t Address,
195                                        const void *Decoder);
196 
197 static DecodeStatus DecodeBranchTarget1SImm16(MCInst &Inst,
198                                               unsigned Offset,
199                                               uint64_t Address,
200                                               const void *Decoder);
201 
202 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
203                                      unsigned Insn,
204                                      uint64_t Address,
205                                      const void *Decoder);
206 
207 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
208                                          unsigned Offset,
209                                          uint64_t Address,
210                                          const void *Decoder);
211 
212 static DecodeStatus DecodeBranchTarget21MM(MCInst &Inst,
213                                            unsigned Offset,
214                                            uint64_t Address,
215                                            const void *Decoder);
216 
217 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
218                                          unsigned Offset,
219                                          uint64_t Address,
220                                          const void *Decoder);
221 
222 // DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
223 // shifted left by 1 bit.
224 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
225                                           unsigned Offset,
226                                           uint64_t Address,
227                                           const void *Decoder);
228 
229 // DecodeBranchTarget10MM - Decode microMIPS branch offset, which is
230 // shifted left by 1 bit.
231 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
232                                            unsigned Offset,
233                                            uint64_t Address,
234                                            const void *Decoder);
235 
236 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
237 // shifted left by 1 bit.
238 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
239                                          unsigned Offset,
240                                          uint64_t Address,
241                                          const void *Decoder);
242 
243 // DecodeBranchTarget26MM - Decode microMIPS branch offset, which is
244 // shifted left by 1 bit.
245 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
246                                            unsigned Offset,
247                                            uint64_t Address,
248                                            const void *Decoder);
249 
250 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
251 // shifted left by 1 bit.
252 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
253                                        unsigned Insn,
254                                        uint64_t Address,
255                                        const void *Decoder);
256 
257 static DecodeStatus DecodeMem(MCInst &Inst,
258                               unsigned Insn,
259                               uint64_t Address,
260                               const void *Decoder);
261 
262 static DecodeStatus DecodeMemEVA(MCInst &Inst,
263                                  unsigned Insn,
264                                  uint64_t Address,
265                                  const void *Decoder);
266 
267 static DecodeStatus DecodeLoadByte9(MCInst &Inst,
268                                     unsigned Insn,
269                                     uint64_t Address,
270                                     const void *Decoder);
271 
272 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
273                                      unsigned Insn,
274                                      uint64_t Address,
275                                      const void *Decoder);
276 
277 static DecodeStatus DecodeCacheOp(MCInst &Inst,
278                               unsigned Insn,
279                               uint64_t Address,
280                               const void *Decoder);
281 
282 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
283                                              unsigned Insn,
284                                              uint64_t Address,
285                                              const void *Decoder);
286 
287 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
288                                     unsigned Insn,
289                                     uint64_t Address,
290                                     const void *Decoder);
291 
292 static DecodeStatus DecodeStoreEvaOpMM(MCInst &Inst,
293                                        unsigned Insn,
294                                        uint64_t Address,
295                                        const void *Decoder);
296 
297 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
298                                     unsigned Insn,
299                                     uint64_t Address,
300                                     const void *Decoder);
301 
302 static DecodeStatus DecodeSyncI(MCInst &Inst,
303                                 unsigned Insn,
304                                 uint64_t Address,
305                                 const void *Decoder);
306 
307 static DecodeStatus DecodeSynciR6(MCInst &Inst,
308                                   unsigned Insn,
309                                   uint64_t Address,
310                                   const void *Decoder);
311 
312 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
313                                     uint64_t Address, const void *Decoder);
314 
315 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
316                                     unsigned Insn,
317                                     uint64_t Address,
318                                     const void *Decoder);
319 
320 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
321                                           unsigned Insn,
322                                           uint64_t Address,
323                                           const void *Decoder);
324 
325 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
326                                           unsigned Insn,
327                                           uint64_t Address,
328                                           const void *Decoder);
329 
330 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
331                                                unsigned Insn,
332                                                uint64_t Address,
333                                                const void *Decoder);
334 
335 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
336                                     unsigned Insn,
337                                     uint64_t Address,
338                                     const void *Decoder);
339 
340 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
341                                      unsigned Insn,
342                                      uint64_t Address,
343                                      const void *Decoder);
344 
345 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
346                                      unsigned Insn,
347                                      uint64_t Address,
348                                      const void *Decoder);
349 
350 static DecodeStatus DecodeFMem(MCInst &Inst, unsigned Insn,
351                                uint64_t Address,
352                                const void *Decoder);
353 
354 static DecodeStatus DecodeFMem2(MCInst &Inst, unsigned Insn,
355                                uint64_t Address,
356                                const void *Decoder);
357 
358 static DecodeStatus DecodeFMem3(MCInst &Inst, unsigned Insn,
359                                uint64_t Address,
360                                const void *Decoder);
361 
362 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst, unsigned Insn,
363                                uint64_t Address,
364                                const void *Decoder);
365 
366 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
367                                        unsigned Insn,
368                                        uint64_t Address,
369                                        const void *Decoder);
370 
371 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
372                                        unsigned Value,
373                                        uint64_t Address,
374                                        const void *Decoder);
375 
376 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
377                                   unsigned Value,
378                                   uint64_t Address,
379                                   const void *Decoder);
380 
381 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
382                                               unsigned Value,
383                                               uint64_t Address,
384                                               const void *Decoder);
385 
386 template <unsigned Bits, int Offset, int Scale>
387 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
388                                                  uint64_t Address,
389                                                  const void *Decoder);
390 
391 template <unsigned Bits, int Offset>
392 static DecodeStatus DecodeUImmWithOffset(MCInst &Inst, unsigned Value,
393                                          uint64_t Address,
394                                          const void *Decoder) {
395   return DecodeUImmWithOffsetAndScale<Bits, Offset, 1>(Inst, Value, Address,
396                                                        Decoder);
397 }
398 
399 template <unsigned Bits, int Offset = 0, int ScaleBy = 1>
400 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
401                                                  uint64_t Address,
402                                                  const void *Decoder);
403 
404 static DecodeStatus DecodeInsSize(MCInst &Inst,
405                                   unsigned Insn,
406                                   uint64_t Address,
407                                   const void *Decoder);
408 
409 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
410                                      uint64_t Address, const void *Decoder);
411 
412 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
413                                      uint64_t Address, const void *Decoder);
414 
415 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
416                                   uint64_t Address, const void *Decoder);
417 
418 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
419                                     uint64_t Address, const void *Decoder);
420 
421 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
422                                      uint64_t Address, const void *Decoder);
423 
424 /// INSVE_[BHWD] have an implicit operand that the generated decoder doesn't
425 /// handle.
426 template <typename InsnType>
427 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
428                                    const void *Decoder);
429 
430 template <typename InsnType>
431 static DecodeStatus
432 DecodeAddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
433                       const void *Decoder);
434 
435 template <typename InsnType>
436 static DecodeStatus
437 DecodeDaddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
438                        const void *Decoder);
439 
440 template <typename InsnType>
441 static DecodeStatus
442 DecodeBlezlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
443                        const void *Decoder);
444 
445 template <typename InsnType>
446 static DecodeStatus
447 DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
448                        const void *Decoder);
449 
450 template <typename InsnType>
451 static DecodeStatus
452 DecodeBgtzGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
453                       const void *Decoder);
454 
455 template <typename InsnType>
456 static DecodeStatus
457 DecodeBlezGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
458                        const void *Decoder);
459 
460 template <typename InsnType>
461 static DecodeStatus
462 DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
463                           const void *Decoder);
464 
465 template <typename InsnType>
466 static DecodeStatus
467 DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
468                           const void *Decoder);
469 
470 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
471                                          uint64_t Address,
472                                          const void *Decoder);
473 
474 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
475                                            uint64_t Address,
476                                            const void *Decoder);
477 
478 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
479                                        uint64_t Address,
480                                        const void *Decoder);
481 
482 namespace llvm {
483 extern Target TheMipselTarget, TheMipsTarget, TheMips64Target,
484               TheMips64elTarget;
485 }
486 
487 static MCDisassembler *createMipsDisassembler(
488                        const Target &T,
489                        const MCSubtargetInfo &STI,
490                        MCContext &Ctx) {
491   return new MipsDisassembler(STI, Ctx, true);
492 }
493 
494 static MCDisassembler *createMipselDisassembler(
495                        const Target &T,
496                        const MCSubtargetInfo &STI,
497                        MCContext &Ctx) {
498   return new MipsDisassembler(STI, Ctx, false);
499 }
500 
501 extern "C" void LLVMInitializeMipsDisassembler() {
502   // Register the disassembler.
503   TargetRegistry::RegisterMCDisassembler(TheMipsTarget,
504                                          createMipsDisassembler);
505   TargetRegistry::RegisterMCDisassembler(TheMipselTarget,
506                                          createMipselDisassembler);
507   TargetRegistry::RegisterMCDisassembler(TheMips64Target,
508                                          createMipsDisassembler);
509   TargetRegistry::RegisterMCDisassembler(TheMips64elTarget,
510                                          createMipselDisassembler);
511 }
512 
513 #include "MipsGenDisassemblerTables.inc"
514 
515 static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) {
516   const MipsDisassembler *Dis = static_cast<const MipsDisassembler*>(D);
517   const MCRegisterInfo *RegInfo = Dis->getContext().getRegisterInfo();
518   return *(RegInfo->getRegClass(RC).begin() + RegNo);
519 }
520 
521 template <typename InsnType>
522 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
523                                    const void *Decoder) {
524   typedef DecodeStatus (*DecodeFN)(MCInst &, unsigned, uint64_t, const void *);
525   // The size of the n field depends on the element size
526   // The register class also depends on this.
527   InsnType tmp = fieldFromInstruction(insn, 17, 5);
528   unsigned NSize = 0;
529   DecodeFN RegDecoder = nullptr;
530   if ((tmp & 0x18) == 0x00) { // INSVE_B
531     NSize = 4;
532     RegDecoder = DecodeMSA128BRegisterClass;
533   } else if ((tmp & 0x1c) == 0x10) { // INSVE_H
534     NSize = 3;
535     RegDecoder = DecodeMSA128HRegisterClass;
536   } else if ((tmp & 0x1e) == 0x18) { // INSVE_W
537     NSize = 2;
538     RegDecoder = DecodeMSA128WRegisterClass;
539   } else if ((tmp & 0x1f) == 0x1c) { // INSVE_D
540     NSize = 1;
541     RegDecoder = DecodeMSA128DRegisterClass;
542   } else
543     llvm_unreachable("Invalid encoding");
544 
545   assert(NSize != 0 && RegDecoder != nullptr);
546 
547   // $wd
548   tmp = fieldFromInstruction(insn, 6, 5);
549   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
550     return MCDisassembler::Fail;
551   // $wd_in
552   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
553     return MCDisassembler::Fail;
554   // $n
555   tmp = fieldFromInstruction(insn, 16, NSize);
556   MI.addOperand(MCOperand::createImm(tmp));
557   // $ws
558   tmp = fieldFromInstruction(insn, 11, 5);
559   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
560     return MCDisassembler::Fail;
561   // $n2
562   MI.addOperand(MCOperand::createImm(0));
563 
564   return MCDisassembler::Success;
565 }
566 
567 template <typename InsnType>
568 static DecodeStatus DecodeAddiGroupBranch(MCInst &MI, InsnType insn,
569                                           uint64_t Address,
570                                           const void *Decoder) {
571   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
572   // (otherwise we would have matched the ADDI instruction from the earlier
573   // ISA's instead).
574   //
575   // We have:
576   //    0b001000 sssss ttttt iiiiiiiiiiiiiiii
577   //      BOVC if rs >= rt
578   //      BEQZALC if rs == 0 && rt != 0
579   //      BEQC if rs < rt && rs != 0
580 
581   InsnType Rs = fieldFromInstruction(insn, 21, 5);
582   InsnType Rt = fieldFromInstruction(insn, 16, 5);
583   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
584   bool HasRs = false;
585 
586   if (Rs >= Rt) {
587     MI.setOpcode(Mips::BOVC);
588     HasRs = true;
589   } else if (Rs != 0 && Rs < Rt) {
590     MI.setOpcode(Mips::BEQC);
591     HasRs = true;
592   } else
593     MI.setOpcode(Mips::BEQZALC);
594 
595   if (HasRs)
596     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
597                                        Rs)));
598 
599   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
600                                      Rt)));
601   MI.addOperand(MCOperand::createImm(Imm));
602 
603   return MCDisassembler::Success;
604 }
605 
606 template <typename InsnType>
607 static DecodeStatus DecodeDaddiGroupBranch(MCInst &MI, InsnType insn,
608                                            uint64_t Address,
609                                            const void *Decoder) {
610   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
611   // (otherwise we would have matched the ADDI instruction from the earlier
612   // ISA's instead).
613   //
614   // We have:
615   //    0b011000 sssss ttttt iiiiiiiiiiiiiiii
616   //      BNVC if rs >= rt
617   //      BNEZALC if rs == 0 && rt != 0
618   //      BNEC if rs < rt && rs != 0
619 
620   InsnType Rs = fieldFromInstruction(insn, 21, 5);
621   InsnType Rt = fieldFromInstruction(insn, 16, 5);
622   int64_t  Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
623   bool HasRs = false;
624 
625   if (Rs >= Rt) {
626     MI.setOpcode(Mips::BNVC);
627     HasRs = true;
628   } else if (Rs != 0 && Rs < Rt) {
629     MI.setOpcode(Mips::BNEC);
630     HasRs = true;
631   } else
632     MI.setOpcode(Mips::BNEZALC);
633 
634   if (HasRs)
635     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
636                                        Rs)));
637 
638   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
639                                      Rt)));
640   MI.addOperand(MCOperand::createImm(Imm));
641 
642   return MCDisassembler::Success;
643 }
644 
645 template <typename InsnType>
646 static DecodeStatus DecodeBlezlGroupBranch(MCInst &MI, InsnType insn,
647                                            uint64_t Address,
648                                            const void *Decoder) {
649   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
650   // (otherwise we would have matched the BLEZL instruction from the earlier
651   // ISA's instead).
652   //
653   // We have:
654   //    0b010110 sssss ttttt iiiiiiiiiiiiiiii
655   //      Invalid if rs == 0
656   //      BLEZC   if rs == 0  && rt != 0
657   //      BGEZC   if rs == rt && rt != 0
658   //      BGEC    if rs != rt && rs != 0  && rt != 0
659 
660   InsnType Rs = fieldFromInstruction(insn, 21, 5);
661   InsnType Rt = fieldFromInstruction(insn, 16, 5);
662   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
663   bool HasRs = false;
664 
665   if (Rt == 0)
666     return MCDisassembler::Fail;
667   else if (Rs == 0)
668     MI.setOpcode(Mips::BLEZC);
669   else if (Rs == Rt)
670     MI.setOpcode(Mips::BGEZC);
671   else {
672     HasRs = true;
673     MI.setOpcode(Mips::BGEC);
674   }
675 
676   if (HasRs)
677     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
678                                        Rs)));
679 
680   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
681                                      Rt)));
682 
683   MI.addOperand(MCOperand::createImm(Imm));
684 
685   return MCDisassembler::Success;
686 }
687 
688 template <typename InsnType>
689 static DecodeStatus DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn,
690                                            uint64_t Address,
691                                            const void *Decoder) {
692   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
693   // (otherwise we would have matched the BGTZL instruction from the earlier
694   // ISA's instead).
695   //
696   // We have:
697   //    0b010111 sssss ttttt iiiiiiiiiiiiiiii
698   //      Invalid if rs == 0
699   //      BGTZC   if rs == 0  && rt != 0
700   //      BLTZC   if rs == rt && rt != 0
701   //      BLTC    if rs != rt && rs != 0  && rt != 0
702 
703   bool HasRs = false;
704 
705   InsnType Rs = fieldFromInstruction(insn, 21, 5);
706   InsnType Rt = fieldFromInstruction(insn, 16, 5);
707   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
708 
709   if (Rt == 0)
710     return MCDisassembler::Fail;
711   else if (Rs == 0)
712     MI.setOpcode(Mips::BGTZC);
713   else if (Rs == Rt)
714     MI.setOpcode(Mips::BLTZC);
715   else {
716     MI.setOpcode(Mips::BLTC);
717     HasRs = true;
718   }
719 
720   if (HasRs)
721     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
722                                               Rs)));
723 
724   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
725                                      Rt)));
726 
727   MI.addOperand(MCOperand::createImm(Imm));
728 
729   return MCDisassembler::Success;
730 }
731 
732 template <typename InsnType>
733 static DecodeStatus DecodeBgtzGroupBranch(MCInst &MI, InsnType insn,
734                                           uint64_t Address,
735                                           const void *Decoder) {
736   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
737   // (otherwise we would have matched the BGTZ instruction from the earlier
738   // ISA's instead).
739   //
740   // We have:
741   //    0b000111 sssss ttttt iiiiiiiiiiiiiiii
742   //      BGTZ    if rt == 0
743   //      BGTZALC if rs == 0 && rt != 0
744   //      BLTZALC if rs != 0 && rs == rt
745   //      BLTUC   if rs != 0 && rs != rt
746 
747   InsnType Rs = fieldFromInstruction(insn, 21, 5);
748   InsnType Rt = fieldFromInstruction(insn, 16, 5);
749   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
750   bool HasRs = false;
751   bool HasRt = false;
752 
753   if (Rt == 0) {
754     MI.setOpcode(Mips::BGTZ);
755     HasRs = true;
756   } else if (Rs == 0) {
757     MI.setOpcode(Mips::BGTZALC);
758     HasRt = true;
759   } else if (Rs == Rt) {
760     MI.setOpcode(Mips::BLTZALC);
761     HasRs = true;
762   } else {
763     MI.setOpcode(Mips::BLTUC);
764     HasRs = true;
765     HasRt = true;
766   }
767 
768   if (HasRs)
769     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
770                                        Rs)));
771 
772   if (HasRt)
773     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
774                                        Rt)));
775 
776   MI.addOperand(MCOperand::createImm(Imm));
777 
778   return MCDisassembler::Success;
779 }
780 
781 template <typename InsnType>
782 static DecodeStatus DecodeBlezGroupBranch(MCInst &MI, InsnType insn,
783                                            uint64_t Address,
784                                            const void *Decoder) {
785   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
786   // (otherwise we would have matched the BLEZL instruction from the earlier
787   // ISA's instead).
788   //
789   // We have:
790   //    0b000110 sssss ttttt iiiiiiiiiiiiiiii
791   //      Invalid   if rs == 0
792   //      BLEZALC   if rs == 0  && rt != 0
793   //      BGEZALC   if rs == rt && rt != 0
794   //      BGEUC     if rs != rt && rs != 0  && rt != 0
795 
796   InsnType Rs = fieldFromInstruction(insn, 21, 5);
797   InsnType Rt = fieldFromInstruction(insn, 16, 5);
798   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
799   bool HasRs = false;
800 
801   if (Rt == 0)
802     return MCDisassembler::Fail;
803   else if (Rs == 0)
804     MI.setOpcode(Mips::BLEZALC);
805   else if (Rs == Rt)
806     MI.setOpcode(Mips::BGEZALC);
807   else {
808     HasRs = true;
809     MI.setOpcode(Mips::BGEUC);
810   }
811 
812   if (HasRs)
813     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
814                                        Rs)));
815   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
816                                      Rt)));
817 
818   MI.addOperand(MCOperand::createImm(Imm));
819 
820   return MCDisassembler::Success;
821 }
822 
823 /// Read two bytes from the ArrayRef and return 16 bit halfword sorted
824 /// according to the given endianess.
825 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
826                                       uint64_t &Size, uint32_t &Insn,
827                                       bool IsBigEndian) {
828   // We want to read exactly 2 Bytes of data.
829   if (Bytes.size() < 2) {
830     Size = 0;
831     return MCDisassembler::Fail;
832   }
833 
834   if (IsBigEndian) {
835     Insn = (Bytes[0] << 8) | Bytes[1];
836   } else {
837     Insn = (Bytes[1] << 8) | Bytes[0];
838   }
839 
840   return MCDisassembler::Success;
841 }
842 
843 /// Read four bytes from the ArrayRef and return 32 bit word sorted
844 /// according to the given endianess
845 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
846                                       uint64_t &Size, uint32_t &Insn,
847                                       bool IsBigEndian, bool IsMicroMips) {
848   // We want to read exactly 4 Bytes of data.
849   if (Bytes.size() < 4) {
850     Size = 0;
851     return MCDisassembler::Fail;
852   }
853 
854   // High 16 bits of a 32-bit microMIPS instruction (where the opcode is)
855   // always precede the low 16 bits in the instruction stream (that is, they
856   // are placed at lower addresses in the instruction stream).
857   //
858   // microMIPS byte ordering:
859   //   Big-endian:    0 | 1 | 2 | 3
860   //   Little-endian: 1 | 0 | 3 | 2
861 
862   if (IsBigEndian) {
863     // Encoded as a big-endian 32-bit word in the stream.
864     Insn =
865         (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) | (Bytes[0] << 24);
866   } else {
867     if (IsMicroMips) {
868       Insn = (Bytes[2] << 0) | (Bytes[3] << 8) | (Bytes[0] << 16) |
869              (Bytes[1] << 24);
870     } else {
871       Insn = (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
872              (Bytes[3] << 24);
873     }
874   }
875 
876   return MCDisassembler::Success;
877 }
878 
879 DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
880                                               ArrayRef<uint8_t> Bytes,
881                                               uint64_t Address,
882                                               raw_ostream &VStream,
883                                               raw_ostream &CStream) const {
884   uint32_t Insn;
885   DecodeStatus Result;
886 
887   if (IsMicroMips) {
888     Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian);
889     if (Result == MCDisassembler::Fail)
890       return MCDisassembler::Fail;
891 
892     if (hasMips32r6()) {
893       DEBUG(dbgs() << "Trying MicroMipsR616 table (16-bit instructions):\n");
894       // Calling the auto-generated decoder function for microMIPS32R6
895       // (and microMIPS64R6) 16-bit instructions.
896       Result = decodeInstruction(DecoderTableMicroMipsR616, Instr, Insn,
897                                  Address, this, STI);
898       if (Result != MCDisassembler::Fail) {
899         Size = 2;
900         return Result;
901       }
902     }
903 
904     DEBUG(dbgs() << "Trying MicroMips16 table (16-bit instructions):\n");
905     // Calling the auto-generated decoder function for microMIPS 16-bit
906     // instructions.
907     Result = decodeInstruction(DecoderTableMicroMips16, Instr, Insn, Address,
908                                this, STI);
909     if (Result != MCDisassembler::Fail) {
910       Size = 2;
911       return Result;
912     }
913 
914     Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, true);
915     if (Result == MCDisassembler::Fail)
916       return MCDisassembler::Fail;
917 
918     if (hasMips32r6()) {
919       DEBUG(dbgs() << "Trying MicroMips32r632 table (32-bit instructions):\n");
920       // Calling the auto-generated decoder function.
921       Result = decodeInstruction(DecoderTableMicroMipsR632, Instr, Insn, Address,
922                                  this, STI);
923       if (Result != MCDisassembler::Fail) {
924         Size = 4;
925         return Result;
926       }
927     }
928 
929     DEBUG(dbgs() << "Trying MicroMips32 table (32-bit instructions):\n");
930     // Calling the auto-generated decoder function.
931     Result = decodeInstruction(DecoderTableMicroMips32, Instr, Insn, Address,
932                                this, STI);
933     if (Result != MCDisassembler::Fail) {
934       Size = 4;
935       return Result;
936     }
937 
938     if (hasMips32r6() && isFP64()) {
939       DEBUG(dbgs() << "Trying MicroMips32r6FP64 table (32-bit opcodes):\n");
940       Result = decodeInstruction(DecoderTableMicroMips32r6FP6432, Instr, Insn,
941                                  Address, this, STI);
942       if (Result != MCDisassembler::Fail) {
943         Size = 4;
944         return Result;
945       }
946     }
947 
948     // This is an invalid instruction. Let the disassembler move forward by the
949     // minimum instruction size.
950     Size = 2;
951     return MCDisassembler::Fail;
952   }
953 
954   Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
955   if (Result == MCDisassembler::Fail) {
956     Size = 4;
957     return MCDisassembler::Fail;
958   }
959 
960   if (hasCOP3()) {
961     DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n");
962     Result =
963         decodeInstruction(DecoderTableCOP3_32, Instr, Insn, Address, this, STI);
964     if (Result != MCDisassembler::Fail) {
965       Size = 4;
966       return Result;
967     }
968   }
969 
970   if (hasMips32r6() && isGP64()) {
971     DEBUG(dbgs() << "Trying Mips32r6_64r6 (GPR64) table (32-bit opcodes):\n");
972     Result = decodeInstruction(DecoderTableMips32r6_64r6_GP6432, Instr, Insn,
973                                Address, this, STI);
974     if (Result != MCDisassembler::Fail) {
975       Size = 4;
976       return Result;
977     }
978   }
979 
980   if (hasMips32r6()) {
981     DEBUG(dbgs() << "Trying Mips32r6_64r6 table (32-bit opcodes):\n");
982     Result = decodeInstruction(DecoderTableMips32r6_64r632, Instr, Insn,
983                                Address, this, STI);
984     if (Result != MCDisassembler::Fail) {
985       Size = 4;
986       return Result;
987     }
988   }
989 
990   if (hasCnMips()) {
991     DEBUG(dbgs() << "Trying CnMips table (32-bit opcodes):\n");
992     Result = decodeInstruction(DecoderTableCnMips32, Instr, Insn,
993                                Address, this, STI);
994     if (Result != MCDisassembler::Fail) {
995       Size = 4;
996       return Result;
997     }
998   }
999 
1000   if (isGP64()) {
1001     DEBUG(dbgs() << "Trying Mips64 (GPR64) table (32-bit opcodes):\n");
1002     Result = decodeInstruction(DecoderTableMips6432, Instr, Insn,
1003                                Address, this, STI);
1004     if (Result != MCDisassembler::Fail) {
1005       Size = 4;
1006       return Result;
1007     }
1008   }
1009 
1010   DEBUG(dbgs() << "Trying Mips table (32-bit opcodes):\n");
1011   // Calling the auto-generated decoder function.
1012   Result =
1013       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
1014   if (Result != MCDisassembler::Fail) {
1015     Size = 4;
1016     return Result;
1017   }
1018 
1019   Size = 4;
1020   return MCDisassembler::Fail;
1021 }
1022 
1023 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
1024                                                  unsigned RegNo,
1025                                                  uint64_t Address,
1026                                                  const void *Decoder) {
1027 
1028   return MCDisassembler::Fail;
1029 
1030 }
1031 
1032 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
1033                                              unsigned RegNo,
1034                                              uint64_t Address,
1035                                              const void *Decoder) {
1036 
1037   if (RegNo > 31)
1038     return MCDisassembler::Fail;
1039 
1040   unsigned Reg = getReg(Decoder, Mips::GPR64RegClassID, RegNo);
1041   Inst.addOperand(MCOperand::createReg(Reg));
1042   return MCDisassembler::Success;
1043 }
1044 
1045 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
1046                                                unsigned RegNo,
1047                                                uint64_t Address,
1048                                                const void *Decoder) {
1049   if (RegNo > 7)
1050     return MCDisassembler::Fail;
1051   unsigned Reg = getReg(Decoder, Mips::GPRMM16RegClassID, RegNo);
1052   Inst.addOperand(MCOperand::createReg(Reg));
1053   return MCDisassembler::Success;
1054 }
1055 
1056 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
1057                                                    unsigned RegNo,
1058                                                    uint64_t Address,
1059                                                    const void *Decoder) {
1060   if (RegNo > 7)
1061     return MCDisassembler::Fail;
1062   unsigned Reg = getReg(Decoder, Mips::GPRMM16ZeroRegClassID, RegNo);
1063   Inst.addOperand(MCOperand::createReg(Reg));
1064   return MCDisassembler::Success;
1065 }
1066 
1067 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
1068                                                     unsigned RegNo,
1069                                                     uint64_t Address,
1070                                                     const void *Decoder) {
1071   if (RegNo > 7)
1072     return MCDisassembler::Fail;
1073   unsigned Reg = getReg(Decoder, Mips::GPRMM16MovePRegClassID, RegNo);
1074   Inst.addOperand(MCOperand::createReg(Reg));
1075   return MCDisassembler::Success;
1076 }
1077 
1078 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
1079                                              unsigned RegNo,
1080                                              uint64_t Address,
1081                                              const void *Decoder) {
1082   if (RegNo > 31)
1083     return MCDisassembler::Fail;
1084   unsigned Reg = getReg(Decoder, Mips::GPR32RegClassID, RegNo);
1085   Inst.addOperand(MCOperand::createReg(Reg));
1086   return MCDisassembler::Success;
1087 }
1088 
1089 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
1090                                            unsigned RegNo,
1091                                            uint64_t Address,
1092                                            const void *Decoder) {
1093   if (static_cast<const MipsDisassembler *>(Decoder)->isGP64())
1094     return DecodeGPR64RegisterClass(Inst, RegNo, Address, Decoder);
1095 
1096   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1097 }
1098 
1099 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
1100                                             unsigned RegNo,
1101                                             uint64_t Address,
1102                                             const void *Decoder) {
1103   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1104 }
1105 
1106 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
1107                                              unsigned RegNo,
1108                                              uint64_t Address,
1109                                              const void *Decoder) {
1110   if (RegNo > 31)
1111     return MCDisassembler::Fail;
1112 
1113   unsigned Reg = getReg(Decoder, Mips::FGR64RegClassID, RegNo);
1114   Inst.addOperand(MCOperand::createReg(Reg));
1115   return MCDisassembler::Success;
1116 }
1117 
1118 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
1119                                              unsigned RegNo,
1120                                              uint64_t Address,
1121                                              const void *Decoder) {
1122   if (RegNo > 31)
1123     return MCDisassembler::Fail;
1124 
1125   unsigned Reg = getReg(Decoder, Mips::FGR32RegClassID, RegNo);
1126   Inst.addOperand(MCOperand::createReg(Reg));
1127   return MCDisassembler::Success;
1128 }
1129 
1130 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
1131                                            unsigned RegNo,
1132                                            uint64_t Address,
1133                                            const void *Decoder) {
1134   if (RegNo > 31)
1135     return MCDisassembler::Fail;
1136   unsigned Reg = getReg(Decoder, Mips::CCRRegClassID, RegNo);
1137   Inst.addOperand(MCOperand::createReg(Reg));
1138   return MCDisassembler::Success;
1139 }
1140 
1141 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
1142                                            unsigned RegNo,
1143                                            uint64_t Address,
1144                                            const void *Decoder) {
1145   if (RegNo > 7)
1146     return MCDisassembler::Fail;
1147   unsigned Reg = getReg(Decoder, Mips::FCCRegClassID, RegNo);
1148   Inst.addOperand(MCOperand::createReg(Reg));
1149   return MCDisassembler::Success;
1150 }
1151 
1152 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
1153                                              uint64_t Address,
1154                                              const void *Decoder) {
1155   if (RegNo > 31)
1156     return MCDisassembler::Fail;
1157 
1158   unsigned Reg = getReg(Decoder, Mips::FGRCCRegClassID, RegNo);
1159   Inst.addOperand(MCOperand::createReg(Reg));
1160   return MCDisassembler::Success;
1161 }
1162 
1163 static DecodeStatus DecodeMem(MCInst &Inst,
1164                               unsigned Insn,
1165                               uint64_t Address,
1166                               const void *Decoder) {
1167   int Offset = SignExtend32<16>(Insn & 0xffff);
1168   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1169   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1170 
1171   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1172   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1173 
1174   if (Inst.getOpcode() == Mips::SC ||
1175       Inst.getOpcode() == Mips::SCD)
1176     Inst.addOperand(MCOperand::createReg(Reg));
1177 
1178   Inst.addOperand(MCOperand::createReg(Reg));
1179   Inst.addOperand(MCOperand::createReg(Base));
1180   Inst.addOperand(MCOperand::createImm(Offset));
1181 
1182   return MCDisassembler::Success;
1183 }
1184 
1185 static DecodeStatus DecodeMemEVA(MCInst &Inst,
1186                                  unsigned Insn,
1187                                  uint64_t Address,
1188                                  const void *Decoder) {
1189   int Offset = SignExtend32<9>(Insn >> 7);
1190   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1191   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1192 
1193   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1194   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1195 
1196    if (Inst.getOpcode() == Mips::SCE)
1197      Inst.addOperand(MCOperand::createReg(Reg));
1198 
1199   Inst.addOperand(MCOperand::createReg(Reg));
1200   Inst.addOperand(MCOperand::createReg(Base));
1201   Inst.addOperand(MCOperand::createImm(Offset));
1202 
1203   return MCDisassembler::Success;
1204 }
1205 
1206 static DecodeStatus DecodeLoadByte9(MCInst &Inst,
1207                                     unsigned Insn,
1208                                     uint64_t Address,
1209                                     const void *Decoder) {
1210   int Offset = SignExtend32<9>(Insn & 0x1ff);
1211   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1212   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1213 
1214   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1215   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1216 
1217   Inst.addOperand(MCOperand::createReg(Reg));
1218   Inst.addOperand(MCOperand::createReg(Base));
1219   Inst.addOperand(MCOperand::createImm(Offset));
1220 
1221   return MCDisassembler::Success;
1222 }
1223 
1224 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
1225                                      unsigned Insn,
1226                                      uint64_t Address,
1227                                      const void *Decoder) {
1228   int Offset = SignExtend32<16>(Insn & 0xffff);
1229   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1230   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1231 
1232   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1233   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1234 
1235   Inst.addOperand(MCOperand::createReg(Reg));
1236   Inst.addOperand(MCOperand::createReg(Base));
1237   Inst.addOperand(MCOperand::createImm(Offset));
1238 
1239   return MCDisassembler::Success;
1240 }
1241 
1242 static DecodeStatus DecodeCacheOp(MCInst &Inst,
1243                               unsigned Insn,
1244                               uint64_t Address,
1245                               const void *Decoder) {
1246   int Offset = SignExtend32<16>(Insn & 0xffff);
1247   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1248   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1249 
1250   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1251 
1252   Inst.addOperand(MCOperand::createReg(Base));
1253   Inst.addOperand(MCOperand::createImm(Offset));
1254   Inst.addOperand(MCOperand::createImm(Hint));
1255 
1256   return MCDisassembler::Success;
1257 }
1258 
1259 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
1260                                     unsigned Insn,
1261                                     uint64_t Address,
1262                                     const void *Decoder) {
1263   int Offset = SignExtend32<12>(Insn & 0xfff);
1264   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1265   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1266 
1267   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1268 
1269   Inst.addOperand(MCOperand::createReg(Base));
1270   Inst.addOperand(MCOperand::createImm(Offset));
1271   Inst.addOperand(MCOperand::createImm(Hint));
1272 
1273   return MCDisassembler::Success;
1274 }
1275 
1276 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
1277                                     unsigned Insn,
1278                                     uint64_t Address,
1279                                     const void *Decoder) {
1280   int Offset = SignExtend32<9>(Insn & 0x1ff);
1281   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1282   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1283 
1284   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1285 
1286   Inst.addOperand(MCOperand::createReg(Base));
1287   Inst.addOperand(MCOperand::createImm(Offset));
1288   Inst.addOperand(MCOperand::createImm(Hint));
1289 
1290   return MCDisassembler::Success;
1291 }
1292 
1293 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
1294                                              unsigned Insn,
1295                                              uint64_t Address,
1296                                              const void *Decoder) {
1297   int Offset = SignExtend32<9>(Insn >> 7);
1298   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1299   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1300 
1301   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1302 
1303   Inst.addOperand(MCOperand::createReg(Base));
1304   Inst.addOperand(MCOperand::createImm(Offset));
1305   Inst.addOperand(MCOperand::createImm(Hint));
1306 
1307   return MCDisassembler::Success;
1308 }
1309 
1310 static DecodeStatus DecodeStoreEvaOpMM(MCInst &Inst,
1311                                        unsigned Insn,
1312                                        uint64_t Address,
1313                                        const void *Decoder) {
1314   int Offset = SignExtend32<9>(Insn & 0x1ff);
1315   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1316   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1317 
1318   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1319   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1320 
1321   Inst.addOperand(MCOperand::createReg(Reg));
1322   Inst.addOperand(MCOperand::createReg(Base));
1323   Inst.addOperand(MCOperand::createImm(Offset));
1324 
1325   return MCDisassembler::Success;
1326 }
1327 
1328 static DecodeStatus DecodeSyncI(MCInst &Inst,
1329                               unsigned Insn,
1330                               uint64_t Address,
1331                               const void *Decoder) {
1332   int Offset = SignExtend32<16>(Insn & 0xffff);
1333   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1334 
1335   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1336 
1337   Inst.addOperand(MCOperand::createReg(Base));
1338   Inst.addOperand(MCOperand::createImm(Offset));
1339 
1340   return MCDisassembler::Success;
1341 }
1342 
1343 static DecodeStatus DecodeSynciR6(MCInst &Inst,
1344                                   unsigned Insn,
1345                                   uint64_t Address,
1346                                   const void *Decoder) {
1347   int Immediate = SignExtend32<16>(Insn & 0xffff);
1348   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1349 
1350   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1351 
1352   Inst.addOperand(MCOperand::createReg(Base));
1353   Inst.addOperand(MCOperand::createImm(Immediate));
1354 
1355   return MCDisassembler::Success;
1356 }
1357 
1358 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
1359                                     uint64_t Address, const void *Decoder) {
1360   int Offset = SignExtend32<10>(fieldFromInstruction(Insn, 16, 10));
1361   unsigned Reg = fieldFromInstruction(Insn, 6, 5);
1362   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1363 
1364   Reg = getReg(Decoder, Mips::MSA128BRegClassID, Reg);
1365   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1366 
1367   Inst.addOperand(MCOperand::createReg(Reg));
1368   Inst.addOperand(MCOperand::createReg(Base));
1369 
1370   // The immediate field of an LD/ST instruction is scaled which means it must
1371   // be multiplied (when decoding) by the size (in bytes) of the instructions'
1372   // data format.
1373   // .b - 1 byte
1374   // .h - 2 bytes
1375   // .w - 4 bytes
1376   // .d - 8 bytes
1377   switch(Inst.getOpcode())
1378   {
1379   default:
1380     assert (0 && "Unexpected instruction");
1381     return MCDisassembler::Fail;
1382     break;
1383   case Mips::LD_B:
1384   case Mips::ST_B:
1385     Inst.addOperand(MCOperand::createImm(Offset));
1386     break;
1387   case Mips::LD_H:
1388   case Mips::ST_H:
1389     Inst.addOperand(MCOperand::createImm(Offset * 2));
1390     break;
1391   case Mips::LD_W:
1392   case Mips::ST_W:
1393     Inst.addOperand(MCOperand::createImm(Offset * 4));
1394     break;
1395   case Mips::LD_D:
1396   case Mips::ST_D:
1397     Inst.addOperand(MCOperand::createImm(Offset * 8));
1398     break;
1399   }
1400 
1401   return MCDisassembler::Success;
1402 }
1403 
1404 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
1405                                     unsigned Insn,
1406                                     uint64_t Address,
1407                                     const void *Decoder) {
1408   unsigned Offset = Insn & 0xf;
1409   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1410   unsigned Base = fieldFromInstruction(Insn, 4, 3);
1411 
1412   switch (Inst.getOpcode()) {
1413     case Mips::LBU16_MM:
1414     case Mips::LHU16_MM:
1415     case Mips::LW16_MM:
1416       if (DecodeGPRMM16RegisterClass(Inst, Reg, Address, Decoder)
1417             == MCDisassembler::Fail)
1418         return MCDisassembler::Fail;
1419       break;
1420     case Mips::SB16_MM:
1421     case Mips::SB16_MMR6:
1422     case Mips::SH16_MM:
1423     case Mips::SH16_MMR6:
1424     case Mips::SW16_MM:
1425     case Mips::SW16_MMR6:
1426       if (DecodeGPRMM16ZeroRegisterClass(Inst, Reg, Address, Decoder)
1427             == MCDisassembler::Fail)
1428         return MCDisassembler::Fail;
1429       break;
1430   }
1431 
1432   if (DecodeGPRMM16RegisterClass(Inst, Base, Address, Decoder)
1433         == MCDisassembler::Fail)
1434     return MCDisassembler::Fail;
1435 
1436   switch (Inst.getOpcode()) {
1437     case Mips::LBU16_MM:
1438       if (Offset == 0xf)
1439         Inst.addOperand(MCOperand::createImm(-1));
1440       else
1441         Inst.addOperand(MCOperand::createImm(Offset));
1442       break;
1443     case Mips::SB16_MM:
1444     case Mips::SB16_MMR6:
1445       Inst.addOperand(MCOperand::createImm(Offset));
1446       break;
1447     case Mips::LHU16_MM:
1448     case Mips::SH16_MM:
1449     case Mips::SH16_MMR6:
1450       Inst.addOperand(MCOperand::createImm(Offset << 1));
1451       break;
1452     case Mips::LW16_MM:
1453     case Mips::SW16_MM:
1454     case Mips::SW16_MMR6:
1455       Inst.addOperand(MCOperand::createImm(Offset << 2));
1456       break;
1457   }
1458 
1459   return MCDisassembler::Success;
1460 }
1461 
1462 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
1463                                           unsigned Insn,
1464                                           uint64_t Address,
1465                                           const void *Decoder) {
1466   unsigned Offset = Insn & 0x1F;
1467   unsigned Reg = fieldFromInstruction(Insn, 5, 5);
1468 
1469   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1470 
1471   Inst.addOperand(MCOperand::createReg(Reg));
1472   Inst.addOperand(MCOperand::createReg(Mips::SP));
1473   Inst.addOperand(MCOperand::createImm(Offset << 2));
1474 
1475   return MCDisassembler::Success;
1476 }
1477 
1478 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
1479                                           unsigned Insn,
1480                                           uint64_t Address,
1481                                           const void *Decoder) {
1482   unsigned Offset = Insn & 0x7F;
1483   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1484 
1485   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1486 
1487   Inst.addOperand(MCOperand::createReg(Reg));
1488   Inst.addOperand(MCOperand::createReg(Mips::GP));
1489   Inst.addOperand(MCOperand::createImm(Offset << 2));
1490 
1491   return MCDisassembler::Success;
1492 }
1493 
1494 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
1495                                                unsigned Insn,
1496                                                uint64_t Address,
1497                                                const void *Decoder) {
1498   int Offset;
1499   switch (Inst.getOpcode()) {
1500   case Mips::LWM16_MMR6:
1501   case Mips::SWM16_MMR6:
1502     Offset = fieldFromInstruction(Insn, 4, 4);
1503     break;
1504   default:
1505     Offset = SignExtend32<4>(Insn & 0xf);
1506     break;
1507   }
1508 
1509   if (DecodeRegListOperand16(Inst, Insn, Address, Decoder)
1510       == MCDisassembler::Fail)
1511     return MCDisassembler::Fail;
1512 
1513   Inst.addOperand(MCOperand::createReg(Mips::SP));
1514   Inst.addOperand(MCOperand::createImm(Offset << 2));
1515 
1516   return MCDisassembler::Success;
1517 }
1518 
1519 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
1520                                     unsigned Insn,
1521                                     uint64_t Address,
1522                                     const void *Decoder) {
1523   int Offset = SignExtend32<9>(Insn & 0x1ff);
1524   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1525   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1526 
1527   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1528   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1529 
1530   if (Inst.getOpcode() == Mips::SCE_MM)
1531     Inst.addOperand(MCOperand::createReg(Reg));
1532 
1533   Inst.addOperand(MCOperand::createReg(Reg));
1534   Inst.addOperand(MCOperand::createReg(Base));
1535   Inst.addOperand(MCOperand::createImm(Offset));
1536 
1537   return MCDisassembler::Success;
1538 }
1539 
1540 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
1541                                      unsigned Insn,
1542                                      uint64_t Address,
1543                                      const void *Decoder) {
1544   int Offset = SignExtend32<12>(Insn & 0x0fff);
1545   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1546   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1547 
1548   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1549   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1550 
1551   switch (Inst.getOpcode()) {
1552   case Mips::SWM32_MM:
1553   case Mips::LWM32_MM:
1554     if (DecodeRegListOperand(Inst, Insn, Address, Decoder)
1555         == MCDisassembler::Fail)
1556       return MCDisassembler::Fail;
1557     Inst.addOperand(MCOperand::createReg(Base));
1558     Inst.addOperand(MCOperand::createImm(Offset));
1559     break;
1560   case Mips::SC_MM:
1561     Inst.addOperand(MCOperand::createReg(Reg));
1562     // fallthrough
1563   default:
1564     Inst.addOperand(MCOperand::createReg(Reg));
1565     if (Inst.getOpcode() == Mips::LWP_MM || Inst.getOpcode() == Mips::SWP_MM ||
1566         Inst.getOpcode() == Mips::LWP_MMR6 || Inst.getOpcode() == Mips::SWP_MMR6)
1567       Inst.addOperand(MCOperand::createReg(Reg+1));
1568 
1569     Inst.addOperand(MCOperand::createReg(Base));
1570     Inst.addOperand(MCOperand::createImm(Offset));
1571   }
1572 
1573   return MCDisassembler::Success;
1574 }
1575 
1576 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
1577                                      unsigned Insn,
1578                                      uint64_t Address,
1579                                      const void *Decoder) {
1580   int Offset = SignExtend32<16>(Insn & 0xffff);
1581   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1582   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1583 
1584   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1585   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1586 
1587   Inst.addOperand(MCOperand::createReg(Reg));
1588   Inst.addOperand(MCOperand::createReg(Base));
1589   Inst.addOperand(MCOperand::createImm(Offset));
1590 
1591   return MCDisassembler::Success;
1592 }
1593 
1594 static DecodeStatus DecodeFMem(MCInst &Inst,
1595                                unsigned Insn,
1596                                uint64_t Address,
1597                                const void *Decoder) {
1598   int Offset = SignExtend32<16>(Insn & 0xffff);
1599   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1600   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1601 
1602   Reg = getReg(Decoder, Mips::FGR64RegClassID, Reg);
1603   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1604 
1605   Inst.addOperand(MCOperand::createReg(Reg));
1606   Inst.addOperand(MCOperand::createReg(Base));
1607   Inst.addOperand(MCOperand::createImm(Offset));
1608 
1609   return MCDisassembler::Success;
1610 }
1611 
1612 static DecodeStatus DecodeFMem2(MCInst &Inst,
1613                                unsigned Insn,
1614                                uint64_t Address,
1615                                const void *Decoder) {
1616   int Offset = SignExtend32<16>(Insn & 0xffff);
1617   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1618   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1619 
1620   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1621   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1622 
1623   Inst.addOperand(MCOperand::createReg(Reg));
1624   Inst.addOperand(MCOperand::createReg(Base));
1625   Inst.addOperand(MCOperand::createImm(Offset));
1626 
1627   return MCDisassembler::Success;
1628 }
1629 
1630 static DecodeStatus DecodeFMem3(MCInst &Inst,
1631                                unsigned Insn,
1632                                uint64_t Address,
1633                                const void *Decoder) {
1634   int Offset = SignExtend32<16>(Insn & 0xffff);
1635   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1636   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1637 
1638   Reg = getReg(Decoder, Mips::COP3RegClassID, Reg);
1639   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1640 
1641   Inst.addOperand(MCOperand::createReg(Reg));
1642   Inst.addOperand(MCOperand::createReg(Base));
1643   Inst.addOperand(MCOperand::createImm(Offset));
1644 
1645   return MCDisassembler::Success;
1646 }
1647 
1648 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst,
1649                                     unsigned Insn,
1650                                     uint64_t Address,
1651                                     const void *Decoder) {
1652   int Offset = SignExtend32<11>(Insn & 0x07ff);
1653   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1654   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1655 
1656   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1657   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1658 
1659   Inst.addOperand(MCOperand::createReg(Reg));
1660   Inst.addOperand(MCOperand::createReg(Base));
1661   Inst.addOperand(MCOperand::createImm(Offset));
1662 
1663   return MCDisassembler::Success;
1664 }
1665 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
1666                                        unsigned Insn,
1667                                        uint64_t Address,
1668                                        const void *Decoder) {
1669   int64_t Offset = SignExtend64<9>((Insn >> 7) & 0x1ff);
1670   unsigned Rt = fieldFromInstruction(Insn, 16, 5);
1671   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1672 
1673   Rt = getReg(Decoder, Mips::GPR32RegClassID, Rt);
1674   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1675 
1676   if(Inst.getOpcode() == Mips::SC_R6 || Inst.getOpcode() == Mips::SCD_R6){
1677     Inst.addOperand(MCOperand::createReg(Rt));
1678   }
1679 
1680   Inst.addOperand(MCOperand::createReg(Rt));
1681   Inst.addOperand(MCOperand::createReg(Base));
1682   Inst.addOperand(MCOperand::createImm(Offset));
1683 
1684   return MCDisassembler::Success;
1685 }
1686 
1687 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
1688                                               unsigned RegNo,
1689                                               uint64_t Address,
1690                                               const void *Decoder) {
1691   // Currently only hardware register 29 is supported.
1692   if (RegNo != 29)
1693     return  MCDisassembler::Fail;
1694   Inst.addOperand(MCOperand::createReg(Mips::HWR29));
1695   return MCDisassembler::Success;
1696 }
1697 
1698 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
1699                                               unsigned RegNo,
1700                                               uint64_t Address,
1701                                               const void *Decoder) {
1702   if (RegNo > 30 || RegNo %2)
1703     return MCDisassembler::Fail;
1704 
1705   ;
1706   unsigned Reg = getReg(Decoder, Mips::AFGR64RegClassID, RegNo /2);
1707   Inst.addOperand(MCOperand::createReg(Reg));
1708   return MCDisassembler::Success;
1709 }
1710 
1711 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
1712                                                 unsigned RegNo,
1713                                                 uint64_t Address,
1714                                                 const void *Decoder) {
1715   if (RegNo >= 4)
1716     return MCDisassembler::Fail;
1717 
1718   unsigned Reg = getReg(Decoder, Mips::ACC64DSPRegClassID, RegNo);
1719   Inst.addOperand(MCOperand::createReg(Reg));
1720   return MCDisassembler::Success;
1721 }
1722 
1723 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
1724                                                unsigned RegNo,
1725                                                uint64_t Address,
1726                                                const void *Decoder) {
1727   if (RegNo >= 4)
1728     return MCDisassembler::Fail;
1729 
1730   unsigned Reg = getReg(Decoder, Mips::HI32DSPRegClassID, RegNo);
1731   Inst.addOperand(MCOperand::createReg(Reg));
1732   return MCDisassembler::Success;
1733 }
1734 
1735 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
1736                                                unsigned RegNo,
1737                                                uint64_t Address,
1738                                                const void *Decoder) {
1739   if (RegNo >= 4)
1740     return MCDisassembler::Fail;
1741 
1742   unsigned Reg = getReg(Decoder, Mips::LO32DSPRegClassID, RegNo);
1743   Inst.addOperand(MCOperand::createReg(Reg));
1744   return MCDisassembler::Success;
1745 }
1746 
1747 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
1748                                                unsigned RegNo,
1749                                                uint64_t Address,
1750                                                const void *Decoder) {
1751   if (RegNo > 31)
1752     return MCDisassembler::Fail;
1753 
1754   unsigned Reg = getReg(Decoder, Mips::MSA128BRegClassID, RegNo);
1755   Inst.addOperand(MCOperand::createReg(Reg));
1756   return MCDisassembler::Success;
1757 }
1758 
1759 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
1760                                                unsigned RegNo,
1761                                                uint64_t Address,
1762                                                const void *Decoder) {
1763   if (RegNo > 31)
1764     return MCDisassembler::Fail;
1765 
1766   unsigned Reg = getReg(Decoder, Mips::MSA128HRegClassID, RegNo);
1767   Inst.addOperand(MCOperand::createReg(Reg));
1768   return MCDisassembler::Success;
1769 }
1770 
1771 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
1772                                                unsigned RegNo,
1773                                                uint64_t Address,
1774                                                const void *Decoder) {
1775   if (RegNo > 31)
1776     return MCDisassembler::Fail;
1777 
1778   unsigned Reg = getReg(Decoder, Mips::MSA128WRegClassID, RegNo);
1779   Inst.addOperand(MCOperand::createReg(Reg));
1780   return MCDisassembler::Success;
1781 }
1782 
1783 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
1784                                                unsigned RegNo,
1785                                                uint64_t Address,
1786                                                const void *Decoder) {
1787   if (RegNo > 31)
1788     return MCDisassembler::Fail;
1789 
1790   unsigned Reg = getReg(Decoder, Mips::MSA128DRegClassID, RegNo);
1791   Inst.addOperand(MCOperand::createReg(Reg));
1792   return MCDisassembler::Success;
1793 }
1794 
1795 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
1796                                                unsigned RegNo,
1797                                                uint64_t Address,
1798                                                const void *Decoder) {
1799   if (RegNo > 7)
1800     return MCDisassembler::Fail;
1801 
1802   unsigned Reg = getReg(Decoder, Mips::MSACtrlRegClassID, RegNo);
1803   Inst.addOperand(MCOperand::createReg(Reg));
1804   return MCDisassembler::Success;
1805 }
1806 
1807 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
1808                                             unsigned RegNo,
1809                                             uint64_t Address,
1810                                             const void *Decoder) {
1811   if (RegNo > 31)
1812     return MCDisassembler::Fail;
1813 
1814   unsigned Reg = getReg(Decoder, Mips::COP0RegClassID, RegNo);
1815   Inst.addOperand(MCOperand::createReg(Reg));
1816   return MCDisassembler::Success;
1817 }
1818 
1819 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
1820                                             unsigned RegNo,
1821                                             uint64_t Address,
1822                                             const void *Decoder) {
1823   if (RegNo > 31)
1824     return MCDisassembler::Fail;
1825 
1826   unsigned Reg = getReg(Decoder, Mips::COP2RegClassID, RegNo);
1827   Inst.addOperand(MCOperand::createReg(Reg));
1828   return MCDisassembler::Success;
1829 }
1830 
1831 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
1832                                        unsigned Offset,
1833                                        uint64_t Address,
1834                                        const void *Decoder) {
1835   int32_t BranchOffset = (SignExtend32<16>(Offset) * 4) + 4;
1836   Inst.addOperand(MCOperand::createImm(BranchOffset));
1837   return MCDisassembler::Success;
1838 }
1839 
1840 static DecodeStatus DecodeBranchTarget1SImm16(MCInst &Inst,
1841                                               unsigned Offset,
1842                                               uint64_t Address,
1843                                               const void *Decoder) {
1844   int32_t BranchOffset = (SignExtend32<16>(Offset) * 2);
1845   Inst.addOperand(MCOperand::createImm(BranchOffset));
1846   return MCDisassembler::Success;
1847 }
1848 
1849 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
1850                                      unsigned Insn,
1851                                      uint64_t Address,
1852                                      const void *Decoder) {
1853 
1854   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
1855   Inst.addOperand(MCOperand::createImm(JumpOffset));
1856   return MCDisassembler::Success;
1857 }
1858 
1859 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
1860                                          unsigned Offset,
1861                                          uint64_t Address,
1862                                          const void *Decoder) {
1863   int32_t BranchOffset = SignExtend32<21>(Offset) * 4 + 4;
1864 
1865   Inst.addOperand(MCOperand::createImm(BranchOffset));
1866   return MCDisassembler::Success;
1867 }
1868 
1869 static DecodeStatus DecodeBranchTarget21MM(MCInst &Inst,
1870                                            unsigned Offset,
1871                                            uint64_t Address,
1872                                            const void *Decoder) {
1873   int32_t BranchOffset = SignExtend32<21>(Offset) << 1;
1874 
1875   Inst.addOperand(MCOperand::createImm(BranchOffset));
1876   return MCDisassembler::Success;
1877 }
1878 
1879 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
1880                                          unsigned Offset,
1881                                          uint64_t Address,
1882                                          const void *Decoder) {
1883   int32_t BranchOffset = SignExtend32<26>(Offset) * 4 + 4;
1884 
1885   Inst.addOperand(MCOperand::createImm(BranchOffset));
1886   return MCDisassembler::Success;
1887 }
1888 
1889 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
1890                                           unsigned Offset,
1891                                           uint64_t Address,
1892                                           const void *Decoder) {
1893   int32_t BranchOffset = SignExtend32<7>(Offset) << 1;
1894   Inst.addOperand(MCOperand::createImm(BranchOffset));
1895   return MCDisassembler::Success;
1896 }
1897 
1898 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
1899                                            unsigned Offset,
1900                                            uint64_t Address,
1901                                            const void *Decoder) {
1902   int32_t BranchOffset = SignExtend32<10>(Offset) << 1;
1903   Inst.addOperand(MCOperand::createImm(BranchOffset));
1904   return MCDisassembler::Success;
1905 }
1906 
1907 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
1908                                          unsigned Offset,
1909                                          uint64_t Address,
1910                                          const void *Decoder) {
1911   int32_t BranchOffset = SignExtend32<16>(Offset) * 2;
1912   Inst.addOperand(MCOperand::createImm(BranchOffset));
1913   return MCDisassembler::Success;
1914 }
1915 
1916 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
1917   unsigned Offset,
1918   uint64_t Address,
1919   const void *Decoder) {
1920   int32_t BranchOffset = SignExtend32<26>(Offset) << 1;
1921 
1922   Inst.addOperand(MCOperand::createImm(BranchOffset));
1923   return MCDisassembler::Success;
1924 }
1925 
1926 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
1927                                        unsigned Insn,
1928                                        uint64_t Address,
1929                                        const void *Decoder) {
1930   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 1;
1931   Inst.addOperand(MCOperand::createImm(JumpOffset));
1932   return MCDisassembler::Success;
1933 }
1934 
1935 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
1936                                        unsigned Value,
1937                                        uint64_t Address,
1938                                        const void *Decoder) {
1939   if (Value == 0)
1940     Inst.addOperand(MCOperand::createImm(1));
1941   else if (Value == 0x7)
1942     Inst.addOperand(MCOperand::createImm(-1));
1943   else
1944     Inst.addOperand(MCOperand::createImm(Value << 2));
1945   return MCDisassembler::Success;
1946 }
1947 
1948 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
1949                                   unsigned Value,
1950                                   uint64_t Address,
1951                                   const void *Decoder) {
1952   if (Value == 0x7F)
1953     Inst.addOperand(MCOperand::createImm(-1));
1954   else
1955     Inst.addOperand(MCOperand::createImm(Value));
1956   return MCDisassembler::Success;
1957 }
1958 
1959 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
1960                                               unsigned Value,
1961                                               uint64_t Address,
1962                                               const void *Decoder) {
1963   Inst.addOperand(MCOperand::createImm(Value == 0x0 ? 8 : Value));
1964   return MCDisassembler::Success;
1965 }
1966 
1967 template <unsigned Bits, int Offset, int Scale>
1968 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
1969                                                  uint64_t Address,
1970                                                  const void *Decoder) {
1971   Value &= ((1 << Bits) - 1);
1972   Value *= Scale;
1973   Inst.addOperand(MCOperand::createImm(Value + Offset));
1974   return MCDisassembler::Success;
1975 }
1976 
1977 template <unsigned Bits, int Offset, int ScaleBy>
1978 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
1979                                                  uint64_t Address,
1980                                                  const void *Decoder) {
1981   int32_t Imm = SignExtend32<Bits>(Value) * ScaleBy;
1982   Inst.addOperand(MCOperand::createImm(Imm + Offset));
1983   return MCDisassembler::Success;
1984 }
1985 
1986 static DecodeStatus DecodeInsSize(MCInst &Inst,
1987                                   unsigned Insn,
1988                                   uint64_t Address,
1989                                   const void *Decoder) {
1990   // First we need to grab the pos(lsb) from MCInst.
1991   int Pos = Inst.getOperand(2).getImm();
1992   int Size = (int) Insn - Pos + 1;
1993   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Size)));
1994   return MCDisassembler::Success;
1995 }
1996 
1997 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
1998                                      uint64_t Address, const void *Decoder) {
1999   Inst.addOperand(MCOperand::createImm(SignExtend32<19>(Insn) * 4));
2000   return MCDisassembler::Success;
2001 }
2002 
2003 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
2004                                      uint64_t Address, const void *Decoder) {
2005   Inst.addOperand(MCOperand::createImm(SignExtend32<18>(Insn) * 8));
2006   return MCDisassembler::Success;
2007 }
2008 
2009 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
2010                                   uint64_t Address, const void *Decoder) {
2011   int32_t DecodedValue;
2012   switch (Insn) {
2013   case 0: DecodedValue = 256; break;
2014   case 1: DecodedValue = 257; break;
2015   case 510: DecodedValue = -258; break;
2016   case 511: DecodedValue = -257; break;
2017   default: DecodedValue = SignExtend32<9>(Insn); break;
2018   }
2019   Inst.addOperand(MCOperand::createImm(DecodedValue * 4));
2020   return MCDisassembler::Success;
2021 }
2022 
2023 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
2024                                     uint64_t Address, const void *Decoder) {
2025   // Insn must be >= 0, since it is unsigned that condition is always true.
2026   assert(Insn < 16);
2027   int32_t DecodedValues[] = {128, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64,
2028                              255, 32768, 65535};
2029   Inst.addOperand(MCOperand::createImm(DecodedValues[Insn]));
2030   return MCDisassembler::Success;
2031 }
2032 
2033 static DecodeStatus DecodeRegListOperand(MCInst &Inst,
2034                                          unsigned Insn,
2035                                          uint64_t Address,
2036                                          const void *Decoder) {
2037   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5,
2038                      Mips::S6, Mips::S7, Mips::FP};
2039   unsigned RegNum;
2040 
2041   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
2042 
2043   // Empty register lists are not allowed.
2044   if (RegLst == 0)
2045     return MCDisassembler::Fail;
2046 
2047   RegNum = RegLst & 0xf;
2048 
2049   // RegLst values 10-15, and 26-31 are reserved.
2050   if (RegNum > 9)
2051     return MCDisassembler::Fail;
2052 
2053   for (unsigned i = 0; i < RegNum; i++)
2054     Inst.addOperand(MCOperand::createReg(Regs[i]));
2055 
2056   if (RegLst & 0x10)
2057     Inst.addOperand(MCOperand::createReg(Mips::RA));
2058 
2059   return MCDisassembler::Success;
2060 }
2061 
2062 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
2063                                            uint64_t Address,
2064                                            const void *Decoder) {
2065   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
2066   unsigned RegLst;
2067   switch(Inst.getOpcode()) {
2068   default:
2069     RegLst = fieldFromInstruction(Insn, 4, 2);
2070     break;
2071   case Mips::LWM16_MMR6:
2072   case Mips::SWM16_MMR6:
2073     RegLst = fieldFromInstruction(Insn, 8, 2);
2074     break;
2075   }
2076   unsigned RegNum = RegLst & 0x3;
2077 
2078   for (unsigned i = 0; i <= RegNum; i++)
2079     Inst.addOperand(MCOperand::createReg(Regs[i]));
2080 
2081   Inst.addOperand(MCOperand::createReg(Mips::RA));
2082 
2083   return MCDisassembler::Success;
2084 }
2085 
2086 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
2087                                        uint64_t Address, const void *Decoder) {
2088 
2089   unsigned RegPair = fieldFromInstruction(Insn, 7, 3);
2090 
2091   switch (RegPair) {
2092   default:
2093     return MCDisassembler::Fail;
2094   case 0:
2095     Inst.addOperand(MCOperand::createReg(Mips::A1));
2096     Inst.addOperand(MCOperand::createReg(Mips::A2));
2097     break;
2098   case 1:
2099     Inst.addOperand(MCOperand::createReg(Mips::A1));
2100     Inst.addOperand(MCOperand::createReg(Mips::A3));
2101     break;
2102   case 2:
2103     Inst.addOperand(MCOperand::createReg(Mips::A2));
2104     Inst.addOperand(MCOperand::createReg(Mips::A3));
2105     break;
2106   case 3:
2107     Inst.addOperand(MCOperand::createReg(Mips::A0));
2108     Inst.addOperand(MCOperand::createReg(Mips::S5));
2109     break;
2110   case 4:
2111     Inst.addOperand(MCOperand::createReg(Mips::A0));
2112     Inst.addOperand(MCOperand::createReg(Mips::S6));
2113     break;
2114   case 5:
2115     Inst.addOperand(MCOperand::createReg(Mips::A0));
2116     Inst.addOperand(MCOperand::createReg(Mips::A1));
2117     break;
2118   case 6:
2119     Inst.addOperand(MCOperand::createReg(Mips::A0));
2120     Inst.addOperand(MCOperand::createReg(Mips::A2));
2121     break;
2122   case 7:
2123     Inst.addOperand(MCOperand::createReg(Mips::A0));
2124     Inst.addOperand(MCOperand::createReg(Mips::A3));
2125     break;
2126   }
2127 
2128   return MCDisassembler::Success;
2129 }
2130 
2131 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
2132                                      uint64_t Address, const void *Decoder) {
2133   Inst.addOperand(MCOperand::createImm(SignExtend32<25>(Insn << 2)));
2134   return MCDisassembler::Success;
2135 }
2136 
2137 template <typename InsnType>
2138 static DecodeStatus DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn,
2139   uint64_t Address,
2140   const void *Decoder) {
2141   // We have:
2142   //    0b000111 ttttt sssss iiiiiiiiiiiiiiii
2143   //      Invalid      if rt == 0
2144   //      BGTZALC_MMR6 if rs == 0 && rt != 0
2145   //      BLTZALC_MMR6 if rs != 0 && rs == rt
2146   //      BLTUC_MMR6   if rs != 0 && rs != rt
2147 
2148   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2149   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2150   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2;
2151   bool HasRs = false;
2152   bool HasRt = false;
2153 
2154   if (Rt == 0)
2155     return MCDisassembler::Fail;
2156   else if (Rs == 0) {
2157     MI.setOpcode(Mips::BGTZALC_MMR6);
2158     HasRt = true;
2159   }
2160   else if (Rs == Rt) {
2161     MI.setOpcode(Mips::BLTZALC_MMR6);
2162     HasRs = true;
2163   }
2164   else {
2165     MI.setOpcode(Mips::BLTUC_MMR6);
2166     HasRs = true;
2167     HasRt = true;
2168   }
2169 
2170   if (HasRs)
2171     MI.addOperand(
2172     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2173 
2174   if (HasRt)
2175     MI.addOperand(
2176     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2177 
2178   MI.addOperand(MCOperand::createImm(Imm));
2179 
2180   return MCDisassembler::Success;
2181 }
2182 
2183 template <typename InsnType>
2184 static DecodeStatus DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn,
2185   uint64_t Address,
2186   const void *Decoder) {
2187   // We have:
2188   //    0b000110 ttttt sssss iiiiiiiiiiiiiiii
2189   //      Invalid        if rs == 0
2190   //      BLEZALC_MMR6   if rs == 0  && rt != 0
2191   //      BGEZALC_MMR6   if rs == rt && rt != 0
2192   //      BGEUC_MMR6     if rs != rt && rs != 0  && rt != 0
2193 
2194   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2195   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2196   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2;
2197   bool HasRs = false;
2198 
2199   if (Rt == 0)
2200     return MCDisassembler::Fail;
2201   else if (Rs == 0)
2202     MI.setOpcode(Mips::BLEZALC_MMR6);
2203   else if (Rs == Rt)
2204     MI.setOpcode(Mips::BGEZALC_MMR6);
2205   else {
2206     HasRs = true;
2207     MI.setOpcode(Mips::BGEUC_MMR6);
2208   }
2209 
2210   if (HasRs)
2211     MI.addOperand(
2212     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2213   MI.addOperand(
2214     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2215 
2216   MI.addOperand(MCOperand::createImm(Imm));
2217 
2218   return MCDisassembler::Success;
2219 }
2220