xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp (revision 3078531de10dcae44b253a35125c949ff4235284)
1 //===- MipsDisassembler.cpp - Disassembler for Mips -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is part of the Mips Disassembler.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/MipsMCTargetDesc.h"
14 #include "Mips.h"
15 #include "TargetInfo/MipsTargetInfo.h"
16 #include "llvm/ADT/ArrayRef.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/MCRegisterInfo.h"
22 #include "llvm/MC/MCSubtargetInfo.h"
23 #include "llvm/MC/TargetRegistry.h"
24 #include "llvm/Support/Compiler.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/MathExtras.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include <cassert>
30 #include <cstdint>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "mips-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40 class MipsDisassembler : public MCDisassembler {
41   bool IsMicroMips;
42   bool IsBigEndian;
43 
44 public:
45   MipsDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx, bool IsBigEndian)
46       : MCDisassembler(STI, Ctx),
47         IsMicroMips(STI.getFeatureBits()[Mips::FeatureMicroMips]),
48         IsBigEndian(IsBigEndian) {}
49 
50   bool hasMips2() const { return STI.getFeatureBits()[Mips::FeatureMips2]; }
51   bool hasMips3() const { return STI.getFeatureBits()[Mips::FeatureMips3]; }
52   bool hasMips32() const { return STI.getFeatureBits()[Mips::FeatureMips32]; }
53 
54   bool hasMips32r6() const {
55     return STI.getFeatureBits()[Mips::FeatureMips32r6];
56   }
57 
58   bool isFP64() const { return STI.getFeatureBits()[Mips::FeatureFP64Bit]; }
59 
60   bool isGP64() const { return STI.getFeatureBits()[Mips::FeatureGP64Bit]; }
61 
62   bool isPTR64() const { return STI.getFeatureBits()[Mips::FeaturePTR64Bit]; }
63 
64   bool hasCnMips() const { return STI.getFeatureBits()[Mips::FeatureCnMips]; }
65 
66   bool hasCnMipsP() const { return STI.getFeatureBits()[Mips::FeatureCnMipsP]; }
67 
68   bool hasCOP3() const {
69     // Only present in MIPS-I and MIPS-II
70     return !hasMips32() && !hasMips3();
71   }
72 
73   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
74                               ArrayRef<uint8_t> Bytes, uint64_t Address,
75                               raw_ostream &CStream) const override;
76 };
77 
78 } // end anonymous namespace
79 
80 // Forward declare these because the autogenerated code will reference them.
81 // Definitions are further down.
82 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
83                                              unsigned RegNo,
84                                              uint64_t Address,
85                                              const void *Decoder);
86 
87 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
88                                                  unsigned RegNo,
89                                                  uint64_t Address,
90                                                  const void *Decoder);
91 
92 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
93                                                unsigned RegNo,
94                                                uint64_t Address,
95                                                const void *Decoder);
96 
97 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
98                                                    unsigned RegNo,
99                                                    uint64_t Address,
100                                                    const void *Decoder);
101 
102 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
103                                                     unsigned RegNo,
104                                                     uint64_t Address,
105                                                     const void *Decoder);
106 
107 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
108                                              unsigned RegNo,
109                                              uint64_t Address,
110                                              const void *Decoder);
111 
112 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
113                                            unsigned Insn,
114                                            uint64_t Address,
115                                            const void *Decoder);
116 
117 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
118                                             unsigned RegNo,
119                                             uint64_t Address,
120                                             const void *Decoder);
121 
122 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
123                                              unsigned RegNo,
124                                              uint64_t Address,
125                                              const void *Decoder);
126 
127 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
128                                              unsigned RegNo,
129                                              uint64_t Address,
130                                              const void *Decoder);
131 
132 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
133                                            unsigned RegNo,
134                                            uint64_t Address,
135                                            const void *Decoder);
136 
137 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
138                                            unsigned RegNo,
139                                            uint64_t Address,
140                                            const void *Decoder);
141 
142 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
143                                              uint64_t Address,
144                                              const void *Decoder);
145 
146 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
147                                               unsigned Insn,
148                                               uint64_t Address,
149                                               const void *Decoder);
150 
151 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
152                                               unsigned RegNo,
153                                               uint64_t Address,
154                                               const void *Decoder);
155 
156 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
157                                                 unsigned RegNo,
158                                                 uint64_t Address,
159                                                 const void *Decoder);
160 
161 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
162                                                unsigned RegNo,
163                                                uint64_t Address,
164                                                const void *Decoder);
165 
166 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
167                                                unsigned RegNo,
168                                                uint64_t Address,
169                                                const void *Decoder);
170 
171 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
172                                                unsigned RegNo,
173                                                uint64_t Address,
174                                                const void *Decoder);
175 
176 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
177                                                unsigned RegNo,
178                                                uint64_t Address,
179                                                const void *Decoder);
180 
181 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
182                                                unsigned RegNo,
183                                                uint64_t Address,
184                                                const void *Decoder);
185 
186 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
187                                                unsigned RegNo,
188                                                uint64_t Address,
189                                                const void *Decoder);
190 
191 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
192                                                unsigned RegNo,
193                                                uint64_t Address,
194                                                const void *Decoder);
195 
196 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
197                                             unsigned RegNo,
198                                             uint64_t Address,
199                                             const void *Decoder);
200 
201 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
202                                             unsigned RegNo,
203                                             uint64_t Address,
204                                             const void *Decoder);
205 
206 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
207                                        unsigned Offset,
208                                        uint64_t Address,
209                                        const void *Decoder);
210 
211 static DecodeStatus DecodeBranchTarget1SImm16(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 DecodeBranchTarget21MM(MCInst &Inst,
227                                            unsigned Offset,
228                                            uint64_t Address,
229                                            const void *Decoder);
230 
231 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
232                                          unsigned Offset,
233                                          uint64_t Address,
234                                          const void *Decoder);
235 
236 // DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
237 // shifted left by 1 bit.
238 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
239                                           unsigned Offset,
240                                           uint64_t Address,
241                                           const void *Decoder);
242 
243 // DecodeBranchTarget10MM - Decode microMIPS branch offset, which is
244 // shifted left by 1 bit.
245 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
246                                            unsigned Offset,
247                                            uint64_t Address,
248                                            const void *Decoder);
249 
250 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
251 // shifted left by 1 bit.
252 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
253                                          unsigned Offset,
254                                          uint64_t Address,
255                                          const void *Decoder);
256 
257 // DecodeBranchTarget26MM - Decode microMIPS branch offset, which is
258 // shifted left by 1 bit.
259 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
260                                            unsigned Offset,
261                                            uint64_t Address,
262                                            const void *Decoder);
263 
264 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
265 // shifted left by 1 bit.
266 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
267                                        unsigned Insn,
268                                        uint64_t Address,
269                                        const void *Decoder);
270 
271 // DecodeJumpTargetXMM - Decode microMIPS jump and link exchange target,
272 // which is shifted left by 2 bit.
273 static DecodeStatus DecodeJumpTargetXMM(MCInst &Inst,
274                                         unsigned Insn,
275                                         uint64_t Address,
276                                         const void *Decoder);
277 
278 static DecodeStatus DecodeMem(MCInst &Inst,
279                               unsigned Insn,
280                               uint64_t Address,
281                               const void *Decoder);
282 
283 static DecodeStatus DecodeMemEVA(MCInst &Inst,
284                                  unsigned Insn,
285                                  uint64_t Address,
286                                  const void *Decoder);
287 
288 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
289                                      unsigned Insn,
290                                      uint64_t Address,
291                                      const void *Decoder);
292 
293 static DecodeStatus DecodeCacheOp(MCInst &Inst, unsigned Insn, uint64_t Address,
294                                   const void *Decoder);
295 
296 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
297                                              unsigned Insn,
298                                              uint64_t Address,
299                                              const void *Decoder);
300 
301 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
302                                     unsigned Insn,
303                                     uint64_t Address,
304                                     const void *Decoder);
305 
306 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
307                                     unsigned Insn,
308                                     uint64_t Address,
309                                     const void *Decoder);
310 
311 static DecodeStatus DecodeSyncI(MCInst &Inst,
312                                 unsigned Insn,
313                                 uint64_t Address,
314                                 const void *Decoder);
315 
316 static DecodeStatus DecodeSyncI_MM(MCInst &Inst,
317                                    unsigned Insn,
318                                    uint64_t Address,
319                                    const void *Decoder);
320 
321 static DecodeStatus DecodeSynciR6(MCInst &Inst,
322                                   unsigned Insn,
323                                   uint64_t Address,
324                                   const void *Decoder);
325 
326 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
327                                     uint64_t Address, const void *Decoder);
328 
329 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
330                                     unsigned Insn,
331                                     uint64_t Address,
332                                     const void *Decoder);
333 
334 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
335                                           unsigned Insn,
336                                           uint64_t Address,
337                                           const void *Decoder);
338 
339 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
340                                           unsigned Insn,
341                                           uint64_t Address,
342                                           const void *Decoder);
343 
344 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
345                                                unsigned Insn,
346                                                uint64_t Address,
347                                                const void *Decoder);
348 
349 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
350                                     unsigned Insn,
351                                     uint64_t Address,
352                                     const void *Decoder);
353 
354 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
355                                      unsigned Insn,
356                                      uint64_t Address,
357                                      const void *Decoder);
358 
359 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
360                                      unsigned Insn,
361                                      uint64_t Address,
362                                      const void *Decoder);
363 
364 static DecodeStatus DecodeFMem(MCInst &Inst, unsigned Insn,
365                                uint64_t Address,
366                                const void *Decoder);
367 
368 static DecodeStatus DecodeFMemMMR2(MCInst &Inst, unsigned Insn,
369                                    uint64_t Address,
370                                    const void *Decoder);
371 
372 static DecodeStatus DecodeFMem2(MCInst &Inst, unsigned Insn, uint64_t Address,
373                                 const void *Decoder);
374 
375 static DecodeStatus DecodeFMem3(MCInst &Inst, unsigned Insn, uint64_t Address,
376                                 const void *Decoder);
377 
378 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst, unsigned Insn,
379                                      uint64_t Address, const void *Decoder);
380 
381 static DecodeStatus DecodeFMemCop2MMR6(MCInst &Inst, unsigned Insn,
382                                        uint64_t Address,
383                                        const void *Decoder);
384 
385 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
386                                        unsigned Insn,
387                                        uint64_t Address,
388                                        const void *Decoder);
389 
390 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
391                                        unsigned Value,
392                                        uint64_t Address,
393                                        const void *Decoder);
394 
395 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
396                                   unsigned Value,
397                                   uint64_t Address,
398                                   const void *Decoder);
399 
400 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
401                                               unsigned Value,
402                                               uint64_t Address,
403                                               const void *Decoder);
404 
405 template <unsigned Bits, int Offset, int Scale>
406 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
407                                                  uint64_t Address,
408                                                  const void *Decoder);
409 
410 template <unsigned Bits, int Offset>
411 static DecodeStatus DecodeUImmWithOffset(MCInst &Inst, unsigned Value,
412                                          uint64_t Address,
413                                          const void *Decoder) {
414   return DecodeUImmWithOffsetAndScale<Bits, Offset, 1>(Inst, Value, Address,
415                                                        Decoder);
416 }
417 
418 template <unsigned Bits, int Offset = 0, int ScaleBy = 1>
419 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
420                                                  uint64_t Address,
421                                                  const void *Decoder);
422 
423 static DecodeStatus DecodeInsSize(MCInst &Inst,
424                                   unsigned Insn,
425                                   uint64_t Address,
426                                   const void *Decoder);
427 
428 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
429                                      uint64_t Address, const void *Decoder);
430 
431 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
432                                      uint64_t Address, const void *Decoder);
433 
434 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
435                                   uint64_t Address, const void *Decoder);
436 
437 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
438                                     uint64_t Address, const void *Decoder);
439 
440 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
441                                      uint64_t Address, const void *Decoder);
442 
443 /// INSVE_[BHWD] have an implicit operand that the generated decoder doesn't
444 /// handle.
445 template <typename InsnType>
446 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
447                                    const void *Decoder);
448 
449 template <typename InsnType>
450 static DecodeStatus DecodeDAHIDATIMMR6(MCInst &MI, InsnType insn,
451                                        uint64_t Address, const void *Decoder);
452 
453 template <typename InsnType>
454 static DecodeStatus DecodeDAHIDATI(MCInst &MI, InsnType insn, uint64_t Address,
455                                    const void *Decoder);
456 
457 template <typename InsnType>
458 static DecodeStatus
459 DecodeAddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
460                       const void *Decoder);
461 
462 template <typename InsnType>
463 static DecodeStatus
464 DecodePOP35GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
465                            const void *Decoder);
466 
467 template <typename InsnType>
468 static DecodeStatus
469 DecodeDaddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
470                        const void *Decoder);
471 
472 template <typename InsnType>
473 static DecodeStatus
474 DecodePOP37GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
475                            const void *Decoder);
476 
477 template <typename InsnType>
478 static DecodeStatus
479 DecodePOP65GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
480                            const void *Decoder);
481 
482 template <typename InsnType>
483 static DecodeStatus
484 DecodePOP75GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
485                            const void *Decoder);
486 
487 template <typename InsnType>
488 static DecodeStatus
489 DecodeBlezlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
490                        const void *Decoder);
491 
492 template <typename InsnType>
493 static DecodeStatus
494 DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
495                        const void *Decoder);
496 
497 template <typename InsnType>
498 static DecodeStatus
499 DecodeBgtzGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
500                       const void *Decoder);
501 
502 template <typename InsnType>
503 static DecodeStatus
504 DecodeBlezGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
505                        const void *Decoder);
506 
507 template <typename InsnType>
508 static DecodeStatus
509 DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
510                           const void *Decoder);
511 
512 template <typename InsnType>
513 static DecodeStatus
514 DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
515                           const void *Decoder);
516 
517 template <typename InsnType>
518 static DecodeStatus DecodeDINS(MCInst &MI, InsnType Insn, uint64_t Address,
519                                const void *Decoder);
520 
521 template <typename InsnType>
522 static DecodeStatus DecodeDEXT(MCInst &MI, InsnType Insn, uint64_t Address,
523                                const void *Decoder);
524 
525 template <typename InsnType>
526 static DecodeStatus DecodeCRC(MCInst &MI, InsnType Insn, uint64_t Address,
527                               const void *Decoder);
528 
529 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
530                                          uint64_t Address,
531                                          const void *Decoder);
532 
533 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
534                                            uint64_t Address,
535                                            const void *Decoder);
536 
537 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned RegPair,
538                                        uint64_t Address,
539                                        const void *Decoder);
540 
541 static DecodeStatus DecodeMovePOperands(MCInst &Inst, unsigned Insn,
542                                         uint64_t Address, const void *Decoder);
543 
544 static MCDisassembler *createMipsDisassembler(
545                        const Target &T,
546                        const MCSubtargetInfo &STI,
547                        MCContext &Ctx) {
548   return new MipsDisassembler(STI, Ctx, true);
549 }
550 
551 static MCDisassembler *createMipselDisassembler(
552                        const Target &T,
553                        const MCSubtargetInfo &STI,
554                        MCContext &Ctx) {
555   return new MipsDisassembler(STI, Ctx, false);
556 }
557 
558 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMipsDisassembler() {
559   // Register the disassembler.
560   TargetRegistry::RegisterMCDisassembler(getTheMipsTarget(),
561                                          createMipsDisassembler);
562   TargetRegistry::RegisterMCDisassembler(getTheMipselTarget(),
563                                          createMipselDisassembler);
564   TargetRegistry::RegisterMCDisassembler(getTheMips64Target(),
565                                          createMipsDisassembler);
566   TargetRegistry::RegisterMCDisassembler(getTheMips64elTarget(),
567                                          createMipselDisassembler);
568 }
569 
570 #include "MipsGenDisassemblerTables.inc"
571 
572 static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) {
573   const MipsDisassembler *Dis = static_cast<const MipsDisassembler*>(D);
574   const MCRegisterInfo *RegInfo = Dis->getContext().getRegisterInfo();
575   return *(RegInfo->getRegClass(RC).begin() + RegNo);
576 }
577 
578 template <typename InsnType>
579 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
580                                    const void *Decoder) {
581   using DecodeFN = DecodeStatus (*)(MCInst &, unsigned, uint64_t, const void *);
582 
583   // The size of the n field depends on the element size
584   // The register class also depends on this.
585   InsnType tmp = fieldFromInstruction(insn, 17, 5);
586   unsigned NSize = 0;
587   DecodeFN RegDecoder = nullptr;
588   if ((tmp & 0x18) == 0x00) { // INSVE_B
589     NSize = 4;
590     RegDecoder = DecodeMSA128BRegisterClass;
591   } else if ((tmp & 0x1c) == 0x10) { // INSVE_H
592     NSize = 3;
593     RegDecoder = DecodeMSA128HRegisterClass;
594   } else if ((tmp & 0x1e) == 0x18) { // INSVE_W
595     NSize = 2;
596     RegDecoder = DecodeMSA128WRegisterClass;
597   } else if ((tmp & 0x1f) == 0x1c) { // INSVE_D
598     NSize = 1;
599     RegDecoder = DecodeMSA128DRegisterClass;
600   } else
601     llvm_unreachable("Invalid encoding");
602 
603   assert(NSize != 0 && RegDecoder != nullptr);
604 
605   // $wd
606   tmp = fieldFromInstruction(insn, 6, 5);
607   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
608     return MCDisassembler::Fail;
609   // $wd_in
610   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
611     return MCDisassembler::Fail;
612   // $n
613   tmp = fieldFromInstruction(insn, 16, NSize);
614   MI.addOperand(MCOperand::createImm(tmp));
615   // $ws
616   tmp = fieldFromInstruction(insn, 11, 5);
617   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
618     return MCDisassembler::Fail;
619   // $n2
620   MI.addOperand(MCOperand::createImm(0));
621 
622   return MCDisassembler::Success;
623 }
624 
625 template <typename InsnType>
626 static DecodeStatus DecodeDAHIDATIMMR6(MCInst &MI, InsnType insn,
627                                        uint64_t Address, const void *Decoder) {
628   InsnType Rs = fieldFromInstruction(insn, 16, 5);
629   InsnType Imm = fieldFromInstruction(insn, 0, 16);
630   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
631                                        Rs)));
632   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
633                                        Rs)));
634   MI.addOperand(MCOperand::createImm(Imm));
635 
636   return MCDisassembler::Success;
637 }
638 
639 template <typename InsnType>
640 static DecodeStatus DecodeDAHIDATI(MCInst &MI, InsnType insn, uint64_t Address,
641                                const void *Decoder) {
642   InsnType Rs = fieldFromInstruction(insn, 21, 5);
643   InsnType Imm = fieldFromInstruction(insn, 0, 16);
644   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
645                                        Rs)));
646   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
647                                        Rs)));
648   MI.addOperand(MCOperand::createImm(Imm));
649 
650   return MCDisassembler::Success;
651 }
652 
653 template <typename InsnType>
654 static DecodeStatus DecodeAddiGroupBranch(MCInst &MI, InsnType insn,
655                                           uint64_t Address,
656                                           const void *Decoder) {
657   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
658   // (otherwise we would have matched the ADDI instruction from the earlier
659   // ISA's instead).
660   //
661   // We have:
662   //    0b001000 sssss ttttt iiiiiiiiiiiiiiii
663   //      BOVC if rs >= rt
664   //      BEQZALC if rs == 0 && rt != 0
665   //      BEQC if rs < rt && rs != 0
666 
667   InsnType Rs = fieldFromInstruction(insn, 21, 5);
668   InsnType Rt = fieldFromInstruction(insn, 16, 5);
669   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
670   bool HasRs = false;
671 
672   if (Rs >= Rt) {
673     MI.setOpcode(Mips::BOVC);
674     HasRs = true;
675   } else if (Rs != 0 && Rs < Rt) {
676     MI.setOpcode(Mips::BEQC);
677     HasRs = true;
678   } else
679     MI.setOpcode(Mips::BEQZALC);
680 
681   if (HasRs)
682     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
683                                        Rs)));
684 
685   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
686                                      Rt)));
687   MI.addOperand(MCOperand::createImm(Imm));
688 
689   return MCDisassembler::Success;
690 }
691 
692 template <typename InsnType>
693 static DecodeStatus DecodePOP35GroupBranchMMR6(MCInst &MI, InsnType insn,
694                                                uint64_t Address,
695                                                const void *Decoder) {
696   InsnType Rt = fieldFromInstruction(insn, 21, 5);
697   InsnType Rs = fieldFromInstruction(insn, 16, 5);
698   int64_t Imm = 0;
699 
700   if (Rs >= Rt) {
701     MI.setOpcode(Mips::BOVC_MMR6);
702     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
703                                        Rt)));
704     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
705                                        Rs)));
706     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
707   } else if (Rs != 0 && Rs < Rt) {
708     MI.setOpcode(Mips::BEQC_MMR6);
709     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
710                                        Rs)));
711     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
712                                        Rt)));
713     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
714   } else {
715     MI.setOpcode(Mips::BEQZALC_MMR6);
716     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
717                                        Rt)));
718     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
719   }
720 
721   MI.addOperand(MCOperand::createImm(Imm));
722 
723   return MCDisassembler::Success;
724 }
725 
726 template <typename InsnType>
727 static DecodeStatus DecodeDaddiGroupBranch(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 ADDI instruction from the earlier
732   // ISA's instead).
733   //
734   // We have:
735   //    0b011000 sssss ttttt iiiiiiiiiiiiiiii
736   //      BNVC if rs >= rt
737   //      BNEZALC if rs == 0 && rt != 0
738   //      BNEC if rs < rt && rs != 0
739 
740   InsnType Rs = fieldFromInstruction(insn, 21, 5);
741   InsnType Rt = fieldFromInstruction(insn, 16, 5);
742   int64_t  Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
743   bool HasRs = false;
744 
745   if (Rs >= Rt) {
746     MI.setOpcode(Mips::BNVC);
747     HasRs = true;
748   } else if (Rs != 0 && Rs < Rt) {
749     MI.setOpcode(Mips::BNEC);
750     HasRs = true;
751   } else
752     MI.setOpcode(Mips::BNEZALC);
753 
754   if (HasRs)
755     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
756                                        Rs)));
757 
758   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
759                                      Rt)));
760   MI.addOperand(MCOperand::createImm(Imm));
761 
762   return MCDisassembler::Success;
763 }
764 
765 template <typename InsnType>
766 static DecodeStatus DecodePOP37GroupBranchMMR6(MCInst &MI, InsnType insn,
767                                                uint64_t Address,
768                                                const void *Decoder) {
769   InsnType Rt = fieldFromInstruction(insn, 21, 5);
770   InsnType Rs = fieldFromInstruction(insn, 16, 5);
771   int64_t Imm = 0;
772 
773   if (Rs >= Rt) {
774     MI.setOpcode(Mips::BNVC_MMR6);
775     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
776                                        Rt)));
777     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
778                                        Rs)));
779     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
780   } else if (Rs != 0 && Rs < Rt) {
781     MI.setOpcode(Mips::BNEC_MMR6);
782     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
783                                        Rs)));
784     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
785                                        Rt)));
786     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
787   } else {
788     MI.setOpcode(Mips::BNEZALC_MMR6);
789     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
790                                        Rt)));
791     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
792   }
793 
794   MI.addOperand(MCOperand::createImm(Imm));
795 
796   return MCDisassembler::Success;
797 }
798 
799 template <typename InsnType>
800 static DecodeStatus DecodePOP65GroupBranchMMR6(MCInst &MI, InsnType insn,
801                                                uint64_t Address,
802                                                const void *Decoder) {
803   // We have:
804   //    0b110101 ttttt sssss iiiiiiiiiiiiiiii
805   //      Invalid if rt == 0
806   //      BGTZC_MMR6   if rs == 0  && rt != 0
807   //      BLTZC_MMR6   if rs == rt && rt != 0
808   //      BLTC_MMR6    if rs != rt && rs != 0  && rt != 0
809 
810   InsnType Rt = fieldFromInstruction(insn, 21, 5);
811   InsnType Rs = fieldFromInstruction(insn, 16, 5);
812   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
813   bool HasRs = false;
814 
815   if (Rt == 0)
816     return MCDisassembler::Fail;
817   else if (Rs == 0)
818     MI.setOpcode(Mips::BGTZC_MMR6);
819   else if (Rs == Rt)
820     MI.setOpcode(Mips::BLTZC_MMR6);
821   else {
822     MI.setOpcode(Mips::BLTC_MMR6);
823     HasRs = true;
824   }
825 
826   if (HasRs)
827     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
828                                               Rs)));
829 
830   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
831                                      Rt)));
832 
833   MI.addOperand(MCOperand::createImm(Imm));
834 
835   return MCDisassembler::Success;
836 }
837 
838 template <typename InsnType>
839 static DecodeStatus DecodePOP75GroupBranchMMR6(MCInst &MI, InsnType insn,
840                                                uint64_t Address,
841                                                const void *Decoder) {
842   // We have:
843   //    0b111101 ttttt sssss iiiiiiiiiiiiiiii
844   //      Invalid if rt == 0
845   //      BLEZC_MMR6   if rs == 0  && rt != 0
846   //      BGEZC_MMR6   if rs == rt && rt != 0
847   //      BGEC_MMR6    if rs != rt && rs != 0  && rt != 0
848 
849   InsnType Rt = fieldFromInstruction(insn, 21, 5);
850   InsnType Rs = fieldFromInstruction(insn, 16, 5);
851   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
852   bool HasRs = false;
853 
854   if (Rt == 0)
855     return MCDisassembler::Fail;
856   else if (Rs == 0)
857     MI.setOpcode(Mips::BLEZC_MMR6);
858   else if (Rs == Rt)
859     MI.setOpcode(Mips::BGEZC_MMR6);
860   else {
861     HasRs = true;
862     MI.setOpcode(Mips::BGEC_MMR6);
863   }
864 
865   if (HasRs)
866     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
867                                        Rs)));
868 
869   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
870                                      Rt)));
871 
872   MI.addOperand(MCOperand::createImm(Imm));
873 
874   return MCDisassembler::Success;
875 }
876 
877 template <typename InsnType>
878 static DecodeStatus DecodeBlezlGroupBranch(MCInst &MI, InsnType insn,
879                                            uint64_t Address,
880                                            const void *Decoder) {
881   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
882   // (otherwise we would have matched the BLEZL instruction from the earlier
883   // ISA's instead).
884   //
885   // We have:
886   //    0b010110 sssss ttttt iiiiiiiiiiiiiiii
887   //      Invalid if rs == 0
888   //      BLEZC   if rs == 0  && rt != 0
889   //      BGEZC   if rs == rt && rt != 0
890   //      BGEC    if rs != rt && rs != 0  && rt != 0
891 
892   InsnType Rs = fieldFromInstruction(insn, 21, 5);
893   InsnType Rt = fieldFromInstruction(insn, 16, 5);
894   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
895   bool HasRs = false;
896 
897   if (Rt == 0)
898     return MCDisassembler::Fail;
899   else if (Rs == 0)
900     MI.setOpcode(Mips::BLEZC);
901   else if (Rs == Rt)
902     MI.setOpcode(Mips::BGEZC);
903   else {
904     HasRs = true;
905     MI.setOpcode(Mips::BGEC);
906   }
907 
908   if (HasRs)
909     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
910                                        Rs)));
911 
912   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
913                                      Rt)));
914 
915   MI.addOperand(MCOperand::createImm(Imm));
916 
917   return MCDisassembler::Success;
918 }
919 
920 template <typename InsnType>
921 static DecodeStatus DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn,
922                                            uint64_t Address,
923                                            const void *Decoder) {
924   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
925   // (otherwise we would have matched the BGTZL instruction from the earlier
926   // ISA's instead).
927   //
928   // We have:
929   //    0b010111 sssss ttttt iiiiiiiiiiiiiiii
930   //      Invalid if rs == 0
931   //      BGTZC   if rs == 0  && rt != 0
932   //      BLTZC   if rs == rt && rt != 0
933   //      BLTC    if rs != rt && rs != 0  && rt != 0
934 
935   bool HasRs = false;
936 
937   InsnType Rs = fieldFromInstruction(insn, 21, 5);
938   InsnType Rt = fieldFromInstruction(insn, 16, 5);
939   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
940 
941   if (Rt == 0)
942     return MCDisassembler::Fail;
943   else if (Rs == 0)
944     MI.setOpcode(Mips::BGTZC);
945   else if (Rs == Rt)
946     MI.setOpcode(Mips::BLTZC);
947   else {
948     MI.setOpcode(Mips::BLTC);
949     HasRs = true;
950   }
951 
952   if (HasRs)
953     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
954                                               Rs)));
955 
956   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
957                                      Rt)));
958 
959   MI.addOperand(MCOperand::createImm(Imm));
960 
961   return MCDisassembler::Success;
962 }
963 
964 template <typename InsnType>
965 static DecodeStatus DecodeBgtzGroupBranch(MCInst &MI, InsnType insn,
966                                           uint64_t Address,
967                                           const void *Decoder) {
968   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
969   // (otherwise we would have matched the BGTZ instruction from the earlier
970   // ISA's instead).
971   //
972   // We have:
973   //    0b000111 sssss ttttt iiiiiiiiiiiiiiii
974   //      BGTZ    if rt == 0
975   //      BGTZALC if rs == 0 && rt != 0
976   //      BLTZALC if rs != 0 && rs == rt
977   //      BLTUC   if rs != 0 && rs != rt
978 
979   InsnType Rs = fieldFromInstruction(insn, 21, 5);
980   InsnType Rt = fieldFromInstruction(insn, 16, 5);
981   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
982   bool HasRs = false;
983   bool HasRt = false;
984 
985   if (Rt == 0) {
986     MI.setOpcode(Mips::BGTZ);
987     HasRs = true;
988   } else if (Rs == 0) {
989     MI.setOpcode(Mips::BGTZALC);
990     HasRt = true;
991   } else if (Rs == Rt) {
992     MI.setOpcode(Mips::BLTZALC);
993     HasRs = true;
994   } else {
995     MI.setOpcode(Mips::BLTUC);
996     HasRs = true;
997     HasRt = true;
998   }
999 
1000   if (HasRs)
1001     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1002                                        Rs)));
1003 
1004   if (HasRt)
1005     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1006                                        Rt)));
1007 
1008   MI.addOperand(MCOperand::createImm(Imm));
1009 
1010   return MCDisassembler::Success;
1011 }
1012 
1013 template <typename InsnType>
1014 static DecodeStatus DecodeBlezGroupBranch(MCInst &MI, InsnType insn,
1015                                            uint64_t Address,
1016                                            const void *Decoder) {
1017   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
1018   // (otherwise we would have matched the BLEZL instruction from the earlier
1019   // ISA's instead).
1020   //
1021   // We have:
1022   //    0b000110 sssss ttttt iiiiiiiiiiiiiiii
1023   //      Invalid   if rs == 0
1024   //      BLEZALC   if rs == 0  && rt != 0
1025   //      BGEZALC   if rs == rt && rt != 0
1026   //      BGEUC     if rs != rt && rs != 0  && rt != 0
1027 
1028   InsnType Rs = fieldFromInstruction(insn, 21, 5);
1029   InsnType Rt = fieldFromInstruction(insn, 16, 5);
1030   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
1031   bool HasRs = false;
1032 
1033   if (Rt == 0)
1034     return MCDisassembler::Fail;
1035   else if (Rs == 0)
1036     MI.setOpcode(Mips::BLEZALC);
1037   else if (Rs == Rt)
1038     MI.setOpcode(Mips::BGEZALC);
1039   else {
1040     HasRs = true;
1041     MI.setOpcode(Mips::BGEUC);
1042   }
1043 
1044   if (HasRs)
1045     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1046                                        Rs)));
1047   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1048                                      Rt)));
1049 
1050   MI.addOperand(MCOperand::createImm(Imm));
1051 
1052   return MCDisassembler::Success;
1053 }
1054 
1055 // Override the generated disassembler to produce DEXT all the time. This is
1056 // for feature / behaviour parity with  binutils.
1057 template <typename InsnType>
1058 static DecodeStatus DecodeDEXT(MCInst &MI, InsnType Insn, uint64_t Address,
1059                                const void *Decoder) {
1060   unsigned Msbd = fieldFromInstruction(Insn, 11, 5);
1061   unsigned Lsb = fieldFromInstruction(Insn, 6, 5);
1062   unsigned Size = 0;
1063   unsigned Pos = 0;
1064 
1065   switch (MI.getOpcode()) {
1066     case Mips::DEXT:
1067       Pos = Lsb;
1068       Size = Msbd + 1;
1069       break;
1070     case Mips::DEXTM:
1071       Pos = Lsb;
1072       Size = Msbd + 1 + 32;
1073       break;
1074     case Mips::DEXTU:
1075       Pos = Lsb + 32;
1076       Size = Msbd + 1;
1077       break;
1078     default:
1079       llvm_unreachable("Unknown DEXT instruction!");
1080   }
1081 
1082   MI.setOpcode(Mips::DEXT);
1083 
1084   InsnType Rs = fieldFromInstruction(Insn, 21, 5);
1085   InsnType Rt = fieldFromInstruction(Insn, 16, 5);
1086 
1087   MI.addOperand(
1088       MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rt)));
1089   MI.addOperand(
1090       MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rs)));
1091   MI.addOperand(MCOperand::createImm(Pos));
1092   MI.addOperand(MCOperand::createImm(Size));
1093 
1094   return MCDisassembler::Success;
1095 }
1096 
1097 // Override the generated disassembler to produce DINS all the time. This is
1098 // for feature / behaviour parity with binutils.
1099 template <typename InsnType>
1100 static DecodeStatus DecodeDINS(MCInst &MI, InsnType Insn, uint64_t Address,
1101                                const void *Decoder) {
1102   unsigned Msbd = fieldFromInstruction(Insn, 11, 5);
1103   unsigned Lsb = fieldFromInstruction(Insn, 6, 5);
1104   unsigned Size = 0;
1105   unsigned Pos = 0;
1106 
1107   switch (MI.getOpcode()) {
1108     case Mips::DINS:
1109       Pos = Lsb;
1110       Size = Msbd + 1 - Pos;
1111       break;
1112     case Mips::DINSM:
1113       Pos = Lsb;
1114       Size = Msbd + 33 - Pos;
1115       break;
1116     case Mips::DINSU:
1117       Pos = Lsb + 32;
1118       // mbsd = pos + size - 33
1119       // mbsd - pos + 33 = size
1120       Size = Msbd + 33 - Pos;
1121       break;
1122     default:
1123       llvm_unreachable("Unknown DINS instruction!");
1124   }
1125 
1126   InsnType Rs = fieldFromInstruction(Insn, 21, 5);
1127   InsnType Rt = fieldFromInstruction(Insn, 16, 5);
1128 
1129   MI.setOpcode(Mips::DINS);
1130   MI.addOperand(
1131       MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rt)));
1132   MI.addOperand(
1133       MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rs)));
1134   MI.addOperand(MCOperand::createImm(Pos));
1135   MI.addOperand(MCOperand::createImm(Size));
1136 
1137   return MCDisassembler::Success;
1138 }
1139 
1140 // Auto-generated decoder wouldn't add the third operand for CRC32*.
1141 template <typename InsnType>
1142 static DecodeStatus DecodeCRC(MCInst &MI, InsnType Insn, uint64_t Address,
1143                               const void *Decoder) {
1144   InsnType Rs = fieldFromInstruction(Insn, 21, 5);
1145   InsnType Rt = fieldFromInstruction(Insn, 16, 5);
1146   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1147                                      Rt)));
1148   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1149                                      Rs)));
1150   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1151                                      Rt)));
1152   return MCDisassembler::Success;
1153 }
1154 
1155 /// Read two bytes from the ArrayRef and return 16 bit halfword sorted
1156 /// according to the given endianness.
1157 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
1158                                       uint64_t &Size, uint32_t &Insn,
1159                                       bool IsBigEndian) {
1160   // We want to read exactly 2 Bytes of data.
1161   if (Bytes.size() < 2) {
1162     Size = 0;
1163     return MCDisassembler::Fail;
1164   }
1165 
1166   if (IsBigEndian) {
1167     Insn = (Bytes[0] << 8) | Bytes[1];
1168   } else {
1169     Insn = (Bytes[1] << 8) | Bytes[0];
1170   }
1171 
1172   return MCDisassembler::Success;
1173 }
1174 
1175 /// Read four bytes from the ArrayRef and return 32 bit word sorted
1176 /// according to the given endianness.
1177 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
1178                                       uint64_t &Size, uint32_t &Insn,
1179                                       bool IsBigEndian, bool IsMicroMips) {
1180   // We want to read exactly 4 Bytes of data.
1181   if (Bytes.size() < 4) {
1182     Size = 0;
1183     return MCDisassembler::Fail;
1184   }
1185 
1186   // High 16 bits of a 32-bit microMIPS instruction (where the opcode is)
1187   // always precede the low 16 bits in the instruction stream (that is, they
1188   // are placed at lower addresses in the instruction stream).
1189   //
1190   // microMIPS byte ordering:
1191   //   Big-endian:    0 | 1 | 2 | 3
1192   //   Little-endian: 1 | 0 | 3 | 2
1193 
1194   if (IsBigEndian) {
1195     // Encoded as a big-endian 32-bit word in the stream.
1196     Insn =
1197         (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) | (Bytes[0] << 24);
1198   } else {
1199     if (IsMicroMips) {
1200       Insn = (Bytes[2] << 0) | (Bytes[3] << 8) | (Bytes[0] << 16) |
1201              (Bytes[1] << 24);
1202     } else {
1203       Insn = (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
1204              (Bytes[3] << 24);
1205     }
1206   }
1207 
1208   return MCDisassembler::Success;
1209 }
1210 
1211 DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
1212                                               ArrayRef<uint8_t> Bytes,
1213                                               uint64_t Address,
1214                                               raw_ostream &CStream) const {
1215   uint32_t Insn;
1216   DecodeStatus Result;
1217   Size = 0;
1218 
1219   if (IsMicroMips) {
1220     Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian);
1221     if (Result == MCDisassembler::Fail)
1222       return MCDisassembler::Fail;
1223 
1224     if (hasMips32r6()) {
1225       LLVM_DEBUG(
1226           dbgs() << "Trying MicroMipsR616 table (16-bit instructions):\n");
1227       // Calling the auto-generated decoder function for microMIPS32R6
1228       // 16-bit instructions.
1229       Result = decodeInstruction(DecoderTableMicroMipsR616, Instr, Insn,
1230                                  Address, this, STI);
1231       if (Result != MCDisassembler::Fail) {
1232         Size = 2;
1233         return Result;
1234       }
1235     }
1236 
1237     LLVM_DEBUG(dbgs() << "Trying MicroMips16 table (16-bit instructions):\n");
1238     // Calling the auto-generated decoder function for microMIPS 16-bit
1239     // instructions.
1240     Result = decodeInstruction(DecoderTableMicroMips16, Instr, Insn, Address,
1241                                this, STI);
1242     if (Result != MCDisassembler::Fail) {
1243       Size = 2;
1244       return Result;
1245     }
1246 
1247     Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, true);
1248     if (Result == MCDisassembler::Fail)
1249       return MCDisassembler::Fail;
1250 
1251     if (hasMips32r6()) {
1252       LLVM_DEBUG(
1253           dbgs() << "Trying MicroMips32r632 table (32-bit instructions):\n");
1254       // Calling the auto-generated decoder function.
1255       Result = decodeInstruction(DecoderTableMicroMipsR632, Instr, Insn,
1256                                  Address, this, STI);
1257       if (Result != MCDisassembler::Fail) {
1258         Size = 4;
1259         return Result;
1260       }
1261     }
1262 
1263     LLVM_DEBUG(dbgs() << "Trying MicroMips32 table (32-bit instructions):\n");
1264     // Calling the auto-generated decoder function.
1265     Result = decodeInstruction(DecoderTableMicroMips32, Instr, Insn, Address,
1266                                this, STI);
1267     if (Result != MCDisassembler::Fail) {
1268       Size = 4;
1269       return Result;
1270     }
1271 
1272     if (isFP64()) {
1273       LLVM_DEBUG(dbgs() << "Trying MicroMipsFP64 table (32-bit opcodes):\n");
1274       Result = decodeInstruction(DecoderTableMicroMipsFP6432, Instr, Insn,
1275                                  Address, this, STI);
1276       if (Result != MCDisassembler::Fail) {
1277         Size = 4;
1278         return Result;
1279       }
1280     }
1281 
1282     // This is an invalid instruction. Claim that the Size is 2 bytes. Since
1283     // microMIPS instructions have a minimum alignment of 2, the next 2 bytes
1284     // could form a valid instruction. The two bytes we rejected as an
1285     // instruction could have actually beeen an inline constant pool that is
1286     // unconditionally branched over.
1287     Size = 2;
1288     return MCDisassembler::Fail;
1289   }
1290 
1291   // Attempt to read the instruction so that we can attempt to decode it. If
1292   // the buffer is not 4 bytes long, let the higher level logic figure out
1293   // what to do with a size of zero and MCDisassembler::Fail.
1294   Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
1295   if (Result == MCDisassembler::Fail)
1296     return MCDisassembler::Fail;
1297 
1298   // The only instruction size for standard encoded MIPS.
1299   Size = 4;
1300 
1301   if (hasCOP3()) {
1302     LLVM_DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n");
1303     Result =
1304         decodeInstruction(DecoderTableCOP3_32, Instr, Insn, Address, this, STI);
1305     if (Result != MCDisassembler::Fail)
1306       return Result;
1307   }
1308 
1309   if (hasMips32r6() && isGP64()) {
1310     LLVM_DEBUG(
1311         dbgs() << "Trying Mips32r6_64r6 (GPR64) table (32-bit opcodes):\n");
1312     Result = decodeInstruction(DecoderTableMips32r6_64r6_GP6432, Instr, Insn,
1313                                Address, this, STI);
1314     if (Result != MCDisassembler::Fail)
1315       return Result;
1316   }
1317 
1318   if (hasMips32r6() && isPTR64()) {
1319     LLVM_DEBUG(
1320         dbgs() << "Trying Mips32r6_64r6 (PTR64) table (32-bit opcodes):\n");
1321     Result = decodeInstruction(DecoderTableMips32r6_64r6_PTR6432, Instr, Insn,
1322                                Address, this, STI);
1323     if (Result != MCDisassembler::Fail)
1324       return Result;
1325   }
1326 
1327   if (hasMips32r6()) {
1328     LLVM_DEBUG(dbgs() << "Trying Mips32r6_64r6 table (32-bit opcodes):\n");
1329     Result = decodeInstruction(DecoderTableMips32r6_64r632, Instr, Insn,
1330                                Address, this, STI);
1331     if (Result != MCDisassembler::Fail)
1332       return Result;
1333   }
1334 
1335   if (hasMips2() && isPTR64()) {
1336     LLVM_DEBUG(
1337         dbgs() << "Trying Mips32r6_64r6 (PTR64) table (32-bit opcodes):\n");
1338     Result = decodeInstruction(DecoderTableMips32_64_PTR6432, Instr, Insn,
1339                                Address, this, STI);
1340     if (Result != MCDisassembler::Fail)
1341       return Result;
1342   }
1343 
1344   if (hasCnMips()) {
1345     LLVM_DEBUG(dbgs() << "Trying CnMips table (32-bit opcodes):\n");
1346     Result = decodeInstruction(DecoderTableCnMips32, Instr, Insn,
1347                                Address, this, STI);
1348     if (Result != MCDisassembler::Fail)
1349       return Result;
1350   }
1351 
1352   if (hasCnMipsP()) {
1353     LLVM_DEBUG(dbgs() << "Trying CnMipsP table (32-bit opcodes):\n");
1354     Result = decodeInstruction(DecoderTableCnMipsP32, Instr, Insn,
1355                                Address, this, STI);
1356     if (Result != MCDisassembler::Fail)
1357       return Result;
1358   }
1359 
1360   if (isGP64()) {
1361     LLVM_DEBUG(dbgs() << "Trying Mips64 (GPR64) table (32-bit opcodes):\n");
1362     Result = decodeInstruction(DecoderTableMips6432, Instr, Insn,
1363                                Address, this, STI);
1364     if (Result != MCDisassembler::Fail)
1365       return Result;
1366   }
1367 
1368   if (isFP64()) {
1369     LLVM_DEBUG(
1370         dbgs() << "Trying MipsFP64 (64 bit FPU) table (32-bit opcodes):\n");
1371     Result = decodeInstruction(DecoderTableMipsFP6432, Instr, Insn,
1372                                Address, this, STI);
1373     if (Result != MCDisassembler::Fail)
1374       return Result;
1375   }
1376 
1377   LLVM_DEBUG(dbgs() << "Trying Mips table (32-bit opcodes):\n");
1378   // Calling the auto-generated decoder function.
1379   Result =
1380       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
1381   if (Result != MCDisassembler::Fail)
1382     return Result;
1383 
1384   return MCDisassembler::Fail;
1385 }
1386 
1387 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
1388                                                  unsigned RegNo,
1389                                                  uint64_t Address,
1390                                                  const void *Decoder) {
1391   return MCDisassembler::Fail;
1392 }
1393 
1394 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
1395                                              unsigned RegNo,
1396                                              uint64_t Address,
1397                                              const void *Decoder) {
1398   if (RegNo > 31)
1399     return MCDisassembler::Fail;
1400 
1401   unsigned Reg = getReg(Decoder, Mips::GPR64RegClassID, RegNo);
1402   Inst.addOperand(MCOperand::createReg(Reg));
1403   return MCDisassembler::Success;
1404 }
1405 
1406 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
1407                                                unsigned RegNo,
1408                                                uint64_t Address,
1409                                                const void *Decoder) {
1410   if (RegNo > 7)
1411     return MCDisassembler::Fail;
1412   unsigned Reg = getReg(Decoder, Mips::GPRMM16RegClassID, RegNo);
1413   Inst.addOperand(MCOperand::createReg(Reg));
1414   return MCDisassembler::Success;
1415 }
1416 
1417 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
1418                                                    unsigned RegNo,
1419                                                    uint64_t Address,
1420                                                    const void *Decoder) {
1421   if (RegNo > 7)
1422     return MCDisassembler::Fail;
1423   unsigned Reg = getReg(Decoder, Mips::GPRMM16ZeroRegClassID, RegNo);
1424   Inst.addOperand(MCOperand::createReg(Reg));
1425   return MCDisassembler::Success;
1426 }
1427 
1428 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
1429                                                     unsigned RegNo,
1430                                                     uint64_t Address,
1431                                                     const void *Decoder) {
1432   if (RegNo > 7)
1433     return MCDisassembler::Fail;
1434   unsigned Reg = getReg(Decoder, Mips::GPRMM16MovePRegClassID, RegNo);
1435   Inst.addOperand(MCOperand::createReg(Reg));
1436   return MCDisassembler::Success;
1437 }
1438 
1439 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
1440                                              unsigned RegNo,
1441                                              uint64_t Address,
1442                                              const void *Decoder) {
1443   if (RegNo > 31)
1444     return MCDisassembler::Fail;
1445   unsigned Reg = getReg(Decoder, Mips::GPR32RegClassID, RegNo);
1446   Inst.addOperand(MCOperand::createReg(Reg));
1447   return MCDisassembler::Success;
1448 }
1449 
1450 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
1451                                            unsigned RegNo,
1452                                            uint64_t Address,
1453                                            const void *Decoder) {
1454   if (static_cast<const MipsDisassembler *>(Decoder)->isGP64())
1455     return DecodeGPR64RegisterClass(Inst, RegNo, Address, Decoder);
1456 
1457   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1458 }
1459 
1460 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
1461                                             unsigned RegNo,
1462                                             uint64_t Address,
1463                                             const void *Decoder) {
1464   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1465 }
1466 
1467 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
1468                                              unsigned RegNo,
1469                                              uint64_t Address,
1470                                              const void *Decoder) {
1471   if (RegNo > 31)
1472     return MCDisassembler::Fail;
1473 
1474   unsigned Reg = getReg(Decoder, Mips::FGR64RegClassID, RegNo);
1475   Inst.addOperand(MCOperand::createReg(Reg));
1476   return MCDisassembler::Success;
1477 }
1478 
1479 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
1480                                              unsigned RegNo,
1481                                              uint64_t Address,
1482                                              const void *Decoder) {
1483   if (RegNo > 31)
1484     return MCDisassembler::Fail;
1485 
1486   unsigned Reg = getReg(Decoder, Mips::FGR32RegClassID, RegNo);
1487   Inst.addOperand(MCOperand::createReg(Reg));
1488   return MCDisassembler::Success;
1489 }
1490 
1491 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
1492                                            unsigned RegNo,
1493                                            uint64_t Address,
1494                                            const void *Decoder) {
1495   if (RegNo > 31)
1496     return MCDisassembler::Fail;
1497   unsigned Reg = getReg(Decoder, Mips::CCRRegClassID, RegNo);
1498   Inst.addOperand(MCOperand::createReg(Reg));
1499   return MCDisassembler::Success;
1500 }
1501 
1502 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
1503                                            unsigned RegNo,
1504                                            uint64_t Address,
1505                                            const void *Decoder) {
1506   if (RegNo > 7)
1507     return MCDisassembler::Fail;
1508   unsigned Reg = getReg(Decoder, Mips::FCCRegClassID, RegNo);
1509   Inst.addOperand(MCOperand::createReg(Reg));
1510   return MCDisassembler::Success;
1511 }
1512 
1513 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
1514                                              uint64_t Address,
1515                                              const void *Decoder) {
1516   if (RegNo > 31)
1517     return MCDisassembler::Fail;
1518 
1519   unsigned Reg = getReg(Decoder, Mips::FGRCCRegClassID, RegNo);
1520   Inst.addOperand(MCOperand::createReg(Reg));
1521   return MCDisassembler::Success;
1522 }
1523 
1524 static DecodeStatus DecodeMem(MCInst &Inst,
1525                               unsigned Insn,
1526                               uint64_t Address,
1527                               const void *Decoder) {
1528   int Offset = SignExtend32<16>(Insn & 0xffff);
1529   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1530   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1531 
1532   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1533   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1534 
1535   if (Inst.getOpcode() == Mips::SC ||
1536       Inst.getOpcode() == Mips::SCD)
1537     Inst.addOperand(MCOperand::createReg(Reg));
1538 
1539   Inst.addOperand(MCOperand::createReg(Reg));
1540   Inst.addOperand(MCOperand::createReg(Base));
1541   Inst.addOperand(MCOperand::createImm(Offset));
1542 
1543   return MCDisassembler::Success;
1544 }
1545 
1546 static DecodeStatus DecodeMemEVA(MCInst &Inst,
1547                                  unsigned Insn,
1548                                  uint64_t Address,
1549                                  const void *Decoder) {
1550   int Offset = SignExtend32<9>(Insn >> 7);
1551   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1552   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1553 
1554   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1555   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1556 
1557    if (Inst.getOpcode() == Mips::SCE)
1558      Inst.addOperand(MCOperand::createReg(Reg));
1559 
1560   Inst.addOperand(MCOperand::createReg(Reg));
1561   Inst.addOperand(MCOperand::createReg(Base));
1562   Inst.addOperand(MCOperand::createImm(Offset));
1563 
1564   return MCDisassembler::Success;
1565 }
1566 
1567 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
1568                                      unsigned Insn,
1569                                      uint64_t Address,
1570                                      const void *Decoder) {
1571   int Offset = SignExtend32<16>(Insn & 0xffff);
1572   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1573   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1574 
1575   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1576   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1577 
1578   Inst.addOperand(MCOperand::createReg(Reg));
1579   Inst.addOperand(MCOperand::createReg(Base));
1580   Inst.addOperand(MCOperand::createImm(Offset));
1581 
1582   return MCDisassembler::Success;
1583 }
1584 
1585 static DecodeStatus DecodeCacheOp(MCInst &Inst,
1586                               unsigned Insn,
1587                               uint64_t Address,
1588                               const void *Decoder) {
1589   int Offset = SignExtend32<16>(Insn & 0xffff);
1590   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1591   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1592 
1593   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1594 
1595   Inst.addOperand(MCOperand::createReg(Base));
1596   Inst.addOperand(MCOperand::createImm(Offset));
1597   Inst.addOperand(MCOperand::createImm(Hint));
1598 
1599   return MCDisassembler::Success;
1600 }
1601 
1602 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
1603                                     unsigned Insn,
1604                                     uint64_t Address,
1605                                     const void *Decoder) {
1606   int Offset = SignExtend32<12>(Insn & 0xfff);
1607   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1608   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1609 
1610   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1611 
1612   Inst.addOperand(MCOperand::createReg(Base));
1613   Inst.addOperand(MCOperand::createImm(Offset));
1614   Inst.addOperand(MCOperand::createImm(Hint));
1615 
1616   return MCDisassembler::Success;
1617 }
1618 
1619 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
1620                                     unsigned Insn,
1621                                     uint64_t Address,
1622                                     const void *Decoder) {
1623   int Offset = SignExtend32<9>(Insn & 0x1ff);
1624   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1625   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1626 
1627   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1628 
1629   Inst.addOperand(MCOperand::createReg(Base));
1630   Inst.addOperand(MCOperand::createImm(Offset));
1631   Inst.addOperand(MCOperand::createImm(Hint));
1632 
1633   return MCDisassembler::Success;
1634 }
1635 
1636 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
1637                                              unsigned Insn,
1638                                              uint64_t Address,
1639                                              const void *Decoder) {
1640   int Offset = SignExtend32<9>(Insn >> 7);
1641   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1642   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1643 
1644   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1645 
1646   Inst.addOperand(MCOperand::createReg(Base));
1647   Inst.addOperand(MCOperand::createImm(Offset));
1648   Inst.addOperand(MCOperand::createImm(Hint));
1649 
1650   return MCDisassembler::Success;
1651 }
1652 
1653 static DecodeStatus DecodeSyncI(MCInst &Inst,
1654                               unsigned Insn,
1655                               uint64_t Address,
1656                               const void *Decoder) {
1657   int Offset = SignExtend32<16>(Insn & 0xffff);
1658   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1659 
1660   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1661 
1662   Inst.addOperand(MCOperand::createReg(Base));
1663   Inst.addOperand(MCOperand::createImm(Offset));
1664 
1665   return MCDisassembler::Success;
1666 }
1667 
1668 static DecodeStatus DecodeSyncI_MM(MCInst &Inst, unsigned Insn,
1669                                    uint64_t Address, const void *Decoder) {
1670   int Offset = SignExtend32<16>(Insn & 0xffff);
1671   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1672 
1673   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1674 
1675   Inst.addOperand(MCOperand::createReg(Base));
1676   Inst.addOperand(MCOperand::createImm(Offset));
1677 
1678   return MCDisassembler::Success;
1679 }
1680 
1681 static DecodeStatus DecodeSynciR6(MCInst &Inst,
1682                                   unsigned Insn,
1683                                   uint64_t Address,
1684                                   const void *Decoder) {
1685   int Immediate = SignExtend32<16>(Insn & 0xffff);
1686   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1687 
1688   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1689 
1690   Inst.addOperand(MCOperand::createReg(Base));
1691   Inst.addOperand(MCOperand::createImm(Immediate));
1692 
1693   return MCDisassembler::Success;
1694 }
1695 
1696 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
1697                                     uint64_t Address, const void *Decoder) {
1698   int Offset = SignExtend32<10>(fieldFromInstruction(Insn, 16, 10));
1699   unsigned Reg = fieldFromInstruction(Insn, 6, 5);
1700   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1701 
1702   Reg = getReg(Decoder, Mips::MSA128BRegClassID, Reg);
1703   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1704 
1705   Inst.addOperand(MCOperand::createReg(Reg));
1706   Inst.addOperand(MCOperand::createReg(Base));
1707 
1708   // The immediate field of an LD/ST instruction is scaled which means it must
1709   // be multiplied (when decoding) by the size (in bytes) of the instructions'
1710   // data format.
1711   // .b - 1 byte
1712   // .h - 2 bytes
1713   // .w - 4 bytes
1714   // .d - 8 bytes
1715   switch(Inst.getOpcode())
1716   {
1717   default:
1718     assert(false && "Unexpected instruction");
1719     return MCDisassembler::Fail;
1720     break;
1721   case Mips::LD_B:
1722   case Mips::ST_B:
1723     Inst.addOperand(MCOperand::createImm(Offset));
1724     break;
1725   case Mips::LD_H:
1726   case Mips::ST_H:
1727     Inst.addOperand(MCOperand::createImm(Offset * 2));
1728     break;
1729   case Mips::LD_W:
1730   case Mips::ST_W:
1731     Inst.addOperand(MCOperand::createImm(Offset * 4));
1732     break;
1733   case Mips::LD_D:
1734   case Mips::ST_D:
1735     Inst.addOperand(MCOperand::createImm(Offset * 8));
1736     break;
1737   }
1738 
1739   return MCDisassembler::Success;
1740 }
1741 
1742 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
1743                                     unsigned Insn,
1744                                     uint64_t Address,
1745                                     const void *Decoder) {
1746   unsigned Offset = Insn & 0xf;
1747   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1748   unsigned Base = fieldFromInstruction(Insn, 4, 3);
1749 
1750   switch (Inst.getOpcode()) {
1751     case Mips::LBU16_MM:
1752     case Mips::LHU16_MM:
1753     case Mips::LW16_MM:
1754       if (DecodeGPRMM16RegisterClass(Inst, Reg, Address, Decoder)
1755             == MCDisassembler::Fail)
1756         return MCDisassembler::Fail;
1757       break;
1758     case Mips::SB16_MM:
1759     case Mips::SB16_MMR6:
1760     case Mips::SH16_MM:
1761     case Mips::SH16_MMR6:
1762     case Mips::SW16_MM:
1763     case Mips::SW16_MMR6:
1764       if (DecodeGPRMM16ZeroRegisterClass(Inst, Reg, Address, Decoder)
1765             == MCDisassembler::Fail)
1766         return MCDisassembler::Fail;
1767       break;
1768   }
1769 
1770   if (DecodeGPRMM16RegisterClass(Inst, Base, Address, Decoder)
1771         == MCDisassembler::Fail)
1772     return MCDisassembler::Fail;
1773 
1774   switch (Inst.getOpcode()) {
1775     case Mips::LBU16_MM:
1776       if (Offset == 0xf)
1777         Inst.addOperand(MCOperand::createImm(-1));
1778       else
1779         Inst.addOperand(MCOperand::createImm(Offset));
1780       break;
1781     case Mips::SB16_MM:
1782     case Mips::SB16_MMR6:
1783       Inst.addOperand(MCOperand::createImm(Offset));
1784       break;
1785     case Mips::LHU16_MM:
1786     case Mips::SH16_MM:
1787     case Mips::SH16_MMR6:
1788       Inst.addOperand(MCOperand::createImm(Offset << 1));
1789       break;
1790     case Mips::LW16_MM:
1791     case Mips::SW16_MM:
1792     case Mips::SW16_MMR6:
1793       Inst.addOperand(MCOperand::createImm(Offset << 2));
1794       break;
1795   }
1796 
1797   return MCDisassembler::Success;
1798 }
1799 
1800 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
1801                                           unsigned Insn,
1802                                           uint64_t Address,
1803                                           const void *Decoder) {
1804   unsigned Offset = Insn & 0x1F;
1805   unsigned Reg = fieldFromInstruction(Insn, 5, 5);
1806 
1807   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1808 
1809   Inst.addOperand(MCOperand::createReg(Reg));
1810   Inst.addOperand(MCOperand::createReg(Mips::SP));
1811   Inst.addOperand(MCOperand::createImm(Offset << 2));
1812 
1813   return MCDisassembler::Success;
1814 }
1815 
1816 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
1817                                           unsigned Insn,
1818                                           uint64_t Address,
1819                                           const void *Decoder) {
1820   unsigned Offset = Insn & 0x7F;
1821   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1822 
1823   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1824 
1825   Inst.addOperand(MCOperand::createReg(Reg));
1826   Inst.addOperand(MCOperand::createReg(Mips::GP));
1827   Inst.addOperand(MCOperand::createImm(Offset << 2));
1828 
1829   return MCDisassembler::Success;
1830 }
1831 
1832 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
1833                                                unsigned Insn,
1834                                                uint64_t Address,
1835                                                const void *Decoder) {
1836   int Offset;
1837   switch (Inst.getOpcode()) {
1838   case Mips::LWM16_MMR6:
1839   case Mips::SWM16_MMR6:
1840     Offset = fieldFromInstruction(Insn, 4, 4);
1841     break;
1842   default:
1843     Offset = SignExtend32<4>(Insn & 0xf);
1844     break;
1845   }
1846 
1847   if (DecodeRegListOperand16(Inst, Insn, Address, Decoder)
1848       == MCDisassembler::Fail)
1849     return MCDisassembler::Fail;
1850 
1851   Inst.addOperand(MCOperand::createReg(Mips::SP));
1852   Inst.addOperand(MCOperand::createImm(Offset << 2));
1853 
1854   return MCDisassembler::Success;
1855 }
1856 
1857 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
1858                                     unsigned Insn,
1859                                     uint64_t Address,
1860                                     const void *Decoder) {
1861   int Offset = SignExtend32<9>(Insn & 0x1ff);
1862   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1863   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1864 
1865   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1866   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1867 
1868   if (Inst.getOpcode() == Mips::SCE_MM || Inst.getOpcode() == Mips::SC_MMR6)
1869     Inst.addOperand(MCOperand::createReg(Reg));
1870 
1871   Inst.addOperand(MCOperand::createReg(Reg));
1872   Inst.addOperand(MCOperand::createReg(Base));
1873   Inst.addOperand(MCOperand::createImm(Offset));
1874 
1875   return MCDisassembler::Success;
1876 }
1877 
1878 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
1879                                      unsigned Insn,
1880                                      uint64_t Address,
1881                                      const void *Decoder) {
1882   int Offset = SignExtend32<12>(Insn & 0x0fff);
1883   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1884   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1885 
1886   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1887   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1888 
1889   switch (Inst.getOpcode()) {
1890   case Mips::SWM32_MM:
1891   case Mips::LWM32_MM:
1892     if (DecodeRegListOperand(Inst, Insn, Address, Decoder)
1893         == MCDisassembler::Fail)
1894       return MCDisassembler::Fail;
1895     Inst.addOperand(MCOperand::createReg(Base));
1896     Inst.addOperand(MCOperand::createImm(Offset));
1897     break;
1898   case Mips::SC_MM:
1899     Inst.addOperand(MCOperand::createReg(Reg));
1900     LLVM_FALLTHROUGH;
1901   default:
1902     Inst.addOperand(MCOperand::createReg(Reg));
1903     if (Inst.getOpcode() == Mips::LWP_MM || Inst.getOpcode() == Mips::SWP_MM)
1904       Inst.addOperand(MCOperand::createReg(Reg+1));
1905 
1906     Inst.addOperand(MCOperand::createReg(Base));
1907     Inst.addOperand(MCOperand::createImm(Offset));
1908   }
1909 
1910   return MCDisassembler::Success;
1911 }
1912 
1913 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
1914                                      unsigned Insn,
1915                                      uint64_t Address,
1916                                      const void *Decoder) {
1917   int Offset = SignExtend32<16>(Insn & 0xffff);
1918   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1919   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1920 
1921   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1922   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1923 
1924   Inst.addOperand(MCOperand::createReg(Reg));
1925   Inst.addOperand(MCOperand::createReg(Base));
1926   Inst.addOperand(MCOperand::createImm(Offset));
1927 
1928   return MCDisassembler::Success;
1929 }
1930 
1931 static DecodeStatus DecodeFMem(MCInst &Inst,
1932                                unsigned Insn,
1933                                uint64_t Address,
1934                                const void *Decoder) {
1935   int Offset = SignExtend32<16>(Insn & 0xffff);
1936   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1937   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1938 
1939   Reg = getReg(Decoder, Mips::FGR64RegClassID, Reg);
1940   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1941 
1942   Inst.addOperand(MCOperand::createReg(Reg));
1943   Inst.addOperand(MCOperand::createReg(Base));
1944   Inst.addOperand(MCOperand::createImm(Offset));
1945 
1946   return MCDisassembler::Success;
1947 }
1948 
1949 static DecodeStatus DecodeFMemMMR2(MCInst &Inst, unsigned Insn,
1950                                    uint64_t Address, const void *Decoder) {
1951   // This function is the same as DecodeFMem but with the Reg and Base fields
1952   // swapped according to microMIPS spec.
1953   int Offset = SignExtend32<16>(Insn & 0xffff);
1954   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1955   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1956 
1957   Reg = getReg(Decoder, Mips::FGR64RegClassID, Reg);
1958   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1959 
1960   Inst.addOperand(MCOperand::createReg(Reg));
1961   Inst.addOperand(MCOperand::createReg(Base));
1962   Inst.addOperand(MCOperand::createImm(Offset));
1963 
1964   return MCDisassembler::Success;
1965 }
1966 
1967 static DecodeStatus DecodeFMem2(MCInst &Inst,
1968                                unsigned Insn,
1969                                uint64_t Address,
1970                                const void *Decoder) {
1971   int Offset = SignExtend32<16>(Insn & 0xffff);
1972   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1973   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1974 
1975   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1976   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1977 
1978   Inst.addOperand(MCOperand::createReg(Reg));
1979   Inst.addOperand(MCOperand::createReg(Base));
1980   Inst.addOperand(MCOperand::createImm(Offset));
1981 
1982   return MCDisassembler::Success;
1983 }
1984 
1985 static DecodeStatus DecodeFMem3(MCInst &Inst,
1986                                unsigned Insn,
1987                                uint64_t Address,
1988                                const void *Decoder) {
1989   int Offset = SignExtend32<16>(Insn & 0xffff);
1990   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1991   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1992 
1993   Reg = getReg(Decoder, Mips::COP3RegClassID, Reg);
1994   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1995 
1996   Inst.addOperand(MCOperand::createReg(Reg));
1997   Inst.addOperand(MCOperand::createReg(Base));
1998   Inst.addOperand(MCOperand::createImm(Offset));
1999 
2000   return MCDisassembler::Success;
2001 }
2002 
2003 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst,
2004                                     unsigned Insn,
2005                                     uint64_t Address,
2006                                     const void *Decoder) {
2007   int Offset = SignExtend32<11>(Insn & 0x07ff);
2008   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
2009   unsigned Base = fieldFromInstruction(Insn, 11, 5);
2010 
2011   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
2012   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2013 
2014   Inst.addOperand(MCOperand::createReg(Reg));
2015   Inst.addOperand(MCOperand::createReg(Base));
2016   Inst.addOperand(MCOperand::createImm(Offset));
2017 
2018   return MCDisassembler::Success;
2019 }
2020 
2021 static DecodeStatus DecodeFMemCop2MMR6(MCInst &Inst, unsigned Insn,
2022                                        uint64_t Address, const void *Decoder) {
2023   int Offset = SignExtend32<11>(Insn & 0x07ff);
2024   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
2025   unsigned Base = fieldFromInstruction(Insn, 16, 5);
2026 
2027   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
2028   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2029 
2030   Inst.addOperand(MCOperand::createReg(Reg));
2031   Inst.addOperand(MCOperand::createReg(Base));
2032   Inst.addOperand(MCOperand::createImm(Offset));
2033 
2034   return MCDisassembler::Success;
2035 }
2036 
2037 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
2038                                        unsigned Insn,
2039                                        uint64_t Address,
2040                                        const void *Decoder) {
2041   int64_t Offset = SignExtend64<9>((Insn >> 7) & 0x1ff);
2042   unsigned Rt = fieldFromInstruction(Insn, 16, 5);
2043   unsigned Base = fieldFromInstruction(Insn, 21, 5);
2044 
2045   Rt = getReg(Decoder, Mips::GPR32RegClassID, Rt);
2046   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2047 
2048   if(Inst.getOpcode() == Mips::SC_R6 || Inst.getOpcode() == Mips::SCD_R6){
2049     Inst.addOperand(MCOperand::createReg(Rt));
2050   }
2051 
2052   Inst.addOperand(MCOperand::createReg(Rt));
2053   Inst.addOperand(MCOperand::createReg(Base));
2054   Inst.addOperand(MCOperand::createImm(Offset));
2055 
2056   return MCDisassembler::Success;
2057 }
2058 
2059 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
2060                                               unsigned RegNo,
2061                                               uint64_t Address,
2062                                               const void *Decoder) {
2063   // Currently only hardware register 29 is supported.
2064   if (RegNo != 29)
2065     return  MCDisassembler::Fail;
2066   Inst.addOperand(MCOperand::createReg(Mips::HWR29));
2067   return MCDisassembler::Success;
2068 }
2069 
2070 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
2071                                               unsigned RegNo,
2072                                               uint64_t Address,
2073                                               const void *Decoder) {
2074   if (RegNo > 30 || RegNo %2)
2075     return MCDisassembler::Fail;
2076 
2077   unsigned Reg = getReg(Decoder, Mips::AFGR64RegClassID, RegNo /2);
2078   Inst.addOperand(MCOperand::createReg(Reg));
2079   return MCDisassembler::Success;
2080 }
2081 
2082 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
2083                                                 unsigned RegNo,
2084                                                 uint64_t Address,
2085                                                 const void *Decoder) {
2086   if (RegNo >= 4)
2087     return MCDisassembler::Fail;
2088 
2089   unsigned Reg = getReg(Decoder, Mips::ACC64DSPRegClassID, RegNo);
2090   Inst.addOperand(MCOperand::createReg(Reg));
2091   return MCDisassembler::Success;
2092 }
2093 
2094 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
2095                                                unsigned RegNo,
2096                                                uint64_t Address,
2097                                                const void *Decoder) {
2098   if (RegNo >= 4)
2099     return MCDisassembler::Fail;
2100 
2101   unsigned Reg = getReg(Decoder, Mips::HI32DSPRegClassID, RegNo);
2102   Inst.addOperand(MCOperand::createReg(Reg));
2103   return MCDisassembler::Success;
2104 }
2105 
2106 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
2107                                                unsigned RegNo,
2108                                                uint64_t Address,
2109                                                const void *Decoder) {
2110   if (RegNo >= 4)
2111     return MCDisassembler::Fail;
2112 
2113   unsigned Reg = getReg(Decoder, Mips::LO32DSPRegClassID, RegNo);
2114   Inst.addOperand(MCOperand::createReg(Reg));
2115   return MCDisassembler::Success;
2116 }
2117 
2118 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
2119                                                unsigned RegNo,
2120                                                uint64_t Address,
2121                                                const void *Decoder) {
2122   if (RegNo > 31)
2123     return MCDisassembler::Fail;
2124 
2125   unsigned Reg = getReg(Decoder, Mips::MSA128BRegClassID, RegNo);
2126   Inst.addOperand(MCOperand::createReg(Reg));
2127   return MCDisassembler::Success;
2128 }
2129 
2130 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
2131                                                unsigned RegNo,
2132                                                uint64_t Address,
2133                                                const void *Decoder) {
2134   if (RegNo > 31)
2135     return MCDisassembler::Fail;
2136 
2137   unsigned Reg = getReg(Decoder, Mips::MSA128HRegClassID, RegNo);
2138   Inst.addOperand(MCOperand::createReg(Reg));
2139   return MCDisassembler::Success;
2140 }
2141 
2142 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
2143                                                unsigned RegNo,
2144                                                uint64_t Address,
2145                                                const void *Decoder) {
2146   if (RegNo > 31)
2147     return MCDisassembler::Fail;
2148 
2149   unsigned Reg = getReg(Decoder, Mips::MSA128WRegClassID, RegNo);
2150   Inst.addOperand(MCOperand::createReg(Reg));
2151   return MCDisassembler::Success;
2152 }
2153 
2154 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
2155                                                unsigned RegNo,
2156                                                uint64_t Address,
2157                                                const void *Decoder) {
2158   if (RegNo > 31)
2159     return MCDisassembler::Fail;
2160 
2161   unsigned Reg = getReg(Decoder, Mips::MSA128DRegClassID, RegNo);
2162   Inst.addOperand(MCOperand::createReg(Reg));
2163   return MCDisassembler::Success;
2164 }
2165 
2166 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
2167                                                unsigned RegNo,
2168                                                uint64_t Address,
2169                                                const void *Decoder) {
2170   if (RegNo > 7)
2171     return MCDisassembler::Fail;
2172 
2173   unsigned Reg = getReg(Decoder, Mips::MSACtrlRegClassID, RegNo);
2174   Inst.addOperand(MCOperand::createReg(Reg));
2175   return MCDisassembler::Success;
2176 }
2177 
2178 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
2179                                             unsigned RegNo,
2180                                             uint64_t Address,
2181                                             const void *Decoder) {
2182   if (RegNo > 31)
2183     return MCDisassembler::Fail;
2184 
2185   unsigned Reg = getReg(Decoder, Mips::COP0RegClassID, RegNo);
2186   Inst.addOperand(MCOperand::createReg(Reg));
2187   return MCDisassembler::Success;
2188 }
2189 
2190 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
2191                                             unsigned RegNo,
2192                                             uint64_t Address,
2193                                             const void *Decoder) {
2194   if (RegNo > 31)
2195     return MCDisassembler::Fail;
2196 
2197   unsigned Reg = getReg(Decoder, Mips::COP2RegClassID, RegNo);
2198   Inst.addOperand(MCOperand::createReg(Reg));
2199   return MCDisassembler::Success;
2200 }
2201 
2202 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
2203                                        unsigned Offset,
2204                                        uint64_t Address,
2205                                        const void *Decoder) {
2206   int32_t BranchOffset = (SignExtend32<16>(Offset) * 4) + 4;
2207   Inst.addOperand(MCOperand::createImm(BranchOffset));
2208   return MCDisassembler::Success;
2209 }
2210 
2211 static DecodeStatus DecodeBranchTarget1SImm16(MCInst &Inst,
2212                                               unsigned Offset,
2213                                               uint64_t Address,
2214                                               const void *Decoder) {
2215   int32_t BranchOffset = (SignExtend32<16>(Offset) * 2);
2216   Inst.addOperand(MCOperand::createImm(BranchOffset));
2217   return MCDisassembler::Success;
2218 }
2219 
2220 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
2221                                      unsigned Insn,
2222                                      uint64_t Address,
2223                                      const void *Decoder) {
2224   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
2225   Inst.addOperand(MCOperand::createImm(JumpOffset));
2226   return MCDisassembler::Success;
2227 }
2228 
2229 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
2230                                          unsigned Offset,
2231                                          uint64_t Address,
2232                                          const void *Decoder) {
2233   int32_t BranchOffset = SignExtend32<21>(Offset) * 4 + 4;
2234 
2235   Inst.addOperand(MCOperand::createImm(BranchOffset));
2236   return MCDisassembler::Success;
2237 }
2238 
2239 static DecodeStatus DecodeBranchTarget21MM(MCInst &Inst,
2240                                            unsigned Offset,
2241                                            uint64_t Address,
2242                                            const void *Decoder) {
2243   int32_t BranchOffset = SignExtend32<21>(Offset) * 4 + 4;
2244 
2245   Inst.addOperand(MCOperand::createImm(BranchOffset));
2246   return MCDisassembler::Success;
2247 }
2248 
2249 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
2250                                          unsigned Offset,
2251                                          uint64_t Address,
2252                                          const void *Decoder) {
2253   int32_t BranchOffset = SignExtend32<26>(Offset) * 4 + 4;
2254 
2255   Inst.addOperand(MCOperand::createImm(BranchOffset));
2256   return MCDisassembler::Success;
2257 }
2258 
2259 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
2260                                           unsigned Offset,
2261                                           uint64_t Address,
2262                                           const void *Decoder) {
2263   int32_t BranchOffset = SignExtend32<8>(Offset << 1);
2264   Inst.addOperand(MCOperand::createImm(BranchOffset));
2265   return MCDisassembler::Success;
2266 }
2267 
2268 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
2269                                            unsigned Offset,
2270                                            uint64_t Address,
2271                                            const void *Decoder) {
2272   int32_t BranchOffset = SignExtend32<11>(Offset << 1);
2273   Inst.addOperand(MCOperand::createImm(BranchOffset));
2274   return MCDisassembler::Success;
2275 }
2276 
2277 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
2278                                          unsigned Offset,
2279                                          uint64_t Address,
2280                                          const void *Decoder) {
2281   int32_t BranchOffset = SignExtend32<16>(Offset) * 2 + 4;
2282   Inst.addOperand(MCOperand::createImm(BranchOffset));
2283   return MCDisassembler::Success;
2284 }
2285 
2286 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
2287   unsigned Offset,
2288   uint64_t Address,
2289   const void *Decoder) {
2290   int32_t BranchOffset = SignExtend32<27>(Offset << 1);
2291 
2292   Inst.addOperand(MCOperand::createImm(BranchOffset));
2293   return MCDisassembler::Success;
2294 }
2295 
2296 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
2297                                        unsigned Insn,
2298                                        uint64_t Address,
2299                                        const void *Decoder) {
2300   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 1;
2301   Inst.addOperand(MCOperand::createImm(JumpOffset));
2302   return MCDisassembler::Success;
2303 }
2304 
2305 static DecodeStatus DecodeJumpTargetXMM(MCInst &Inst,
2306                                         unsigned Insn,
2307                                         uint64_t Address,
2308                                         const void *Decoder) {
2309   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
2310   Inst.addOperand(MCOperand::createImm(JumpOffset));
2311   return MCDisassembler::Success;
2312 }
2313 
2314 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
2315                                        unsigned Value,
2316                                        uint64_t Address,
2317                                        const void *Decoder) {
2318   if (Value == 0)
2319     Inst.addOperand(MCOperand::createImm(1));
2320   else if (Value == 0x7)
2321     Inst.addOperand(MCOperand::createImm(-1));
2322   else
2323     Inst.addOperand(MCOperand::createImm(Value << 2));
2324   return MCDisassembler::Success;
2325 }
2326 
2327 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
2328                                   unsigned Value,
2329                                   uint64_t Address,
2330                                   const void *Decoder) {
2331   if (Value == 0x7F)
2332     Inst.addOperand(MCOperand::createImm(-1));
2333   else
2334     Inst.addOperand(MCOperand::createImm(Value));
2335   return MCDisassembler::Success;
2336 }
2337 
2338 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
2339                                               unsigned Value,
2340                                               uint64_t Address,
2341                                               const void *Decoder) {
2342   Inst.addOperand(MCOperand::createImm(Value == 0x0 ? 8 : Value));
2343   return MCDisassembler::Success;
2344 }
2345 
2346 template <unsigned Bits, int Offset, int Scale>
2347 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
2348                                                  uint64_t Address,
2349                                                  const void *Decoder) {
2350   Value &= ((1 << Bits) - 1);
2351   Value *= Scale;
2352   Inst.addOperand(MCOperand::createImm(Value + Offset));
2353   return MCDisassembler::Success;
2354 }
2355 
2356 template <unsigned Bits, int Offset, int ScaleBy>
2357 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
2358                                                  uint64_t Address,
2359                                                  const void *Decoder) {
2360   int32_t Imm = SignExtend32<Bits>(Value) * ScaleBy;
2361   Inst.addOperand(MCOperand::createImm(Imm + Offset));
2362   return MCDisassembler::Success;
2363 }
2364 
2365 static DecodeStatus DecodeInsSize(MCInst &Inst,
2366                                   unsigned Insn,
2367                                   uint64_t Address,
2368                                   const void *Decoder) {
2369   // First we need to grab the pos(lsb) from MCInst.
2370   // This function only handles the 32 bit variants of ins, as dins
2371   // variants are handled differently.
2372   int Pos = Inst.getOperand(2).getImm();
2373   int Size = (int) Insn - Pos + 1;
2374   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Size)));
2375   return MCDisassembler::Success;
2376 }
2377 
2378 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
2379                                      uint64_t Address, const void *Decoder) {
2380   Inst.addOperand(MCOperand::createImm(SignExtend32<19>(Insn) * 4));
2381   return MCDisassembler::Success;
2382 }
2383 
2384 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
2385                                      uint64_t Address, const void *Decoder) {
2386   Inst.addOperand(MCOperand::createImm(SignExtend32<18>(Insn) * 8));
2387   return MCDisassembler::Success;
2388 }
2389 
2390 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
2391                                   uint64_t Address, const void *Decoder) {
2392   int32_t DecodedValue;
2393   switch (Insn) {
2394   case 0: DecodedValue = 256; break;
2395   case 1: DecodedValue = 257; break;
2396   case 510: DecodedValue = -258; break;
2397   case 511: DecodedValue = -257; break;
2398   default: DecodedValue = SignExtend32<9>(Insn); break;
2399   }
2400   Inst.addOperand(MCOperand::createImm(DecodedValue * 4));
2401   return MCDisassembler::Success;
2402 }
2403 
2404 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
2405                                     uint64_t Address, const void *Decoder) {
2406   // Insn must be >= 0, since it is unsigned that condition is always true.
2407   assert(Insn < 16);
2408   int32_t DecodedValues[] = {128, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64,
2409                              255, 32768, 65535};
2410   Inst.addOperand(MCOperand::createImm(DecodedValues[Insn]));
2411   return MCDisassembler::Success;
2412 }
2413 
2414 static DecodeStatus DecodeRegListOperand(MCInst &Inst,
2415                                          unsigned Insn,
2416                                          uint64_t Address,
2417                                          const void *Decoder) {
2418   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5,
2419                      Mips::S6, Mips::S7, Mips::FP};
2420   unsigned RegNum;
2421 
2422   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
2423 
2424   // Empty register lists are not allowed.
2425   if (RegLst == 0)
2426     return MCDisassembler::Fail;
2427 
2428   RegNum = RegLst & 0xf;
2429 
2430   // RegLst values 10-15, and 26-31 are reserved.
2431   if (RegNum > 9)
2432     return MCDisassembler::Fail;
2433 
2434   for (unsigned i = 0; i < RegNum; i++)
2435     Inst.addOperand(MCOperand::createReg(Regs[i]));
2436 
2437   if (RegLst & 0x10)
2438     Inst.addOperand(MCOperand::createReg(Mips::RA));
2439 
2440   return MCDisassembler::Success;
2441 }
2442 
2443 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
2444                                            uint64_t Address,
2445                                            const void *Decoder) {
2446   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
2447   unsigned RegLst;
2448   switch(Inst.getOpcode()) {
2449   default:
2450     RegLst = fieldFromInstruction(Insn, 4, 2);
2451     break;
2452   case Mips::LWM16_MMR6:
2453   case Mips::SWM16_MMR6:
2454     RegLst = fieldFromInstruction(Insn, 8, 2);
2455     break;
2456   }
2457   unsigned RegNum = RegLst & 0x3;
2458 
2459   for (unsigned i = 0; i <= RegNum; i++)
2460     Inst.addOperand(MCOperand::createReg(Regs[i]));
2461 
2462   Inst.addOperand(MCOperand::createReg(Mips::RA));
2463 
2464   return MCDisassembler::Success;
2465 }
2466 
2467 static DecodeStatus DecodeMovePOperands(MCInst &Inst, unsigned Insn,
2468                                           uint64_t Address,
2469                                           const void *Decoder) {
2470   unsigned RegPair = fieldFromInstruction(Insn, 7, 3);
2471   if (DecodeMovePRegPair(Inst, RegPair, Address, Decoder) ==
2472       MCDisassembler::Fail)
2473     return MCDisassembler::Fail;
2474 
2475   unsigned RegRs;
2476   if (static_cast<const MipsDisassembler*>(Decoder)->hasMips32r6())
2477     RegRs = fieldFromInstruction(Insn, 0, 2) |
2478             (fieldFromInstruction(Insn, 3, 1) << 2);
2479   else
2480     RegRs = fieldFromInstruction(Insn, 1, 3);
2481   if (DecodeGPRMM16MovePRegisterClass(Inst, RegRs, Address, Decoder) ==
2482       MCDisassembler::Fail)
2483     return MCDisassembler::Fail;
2484 
2485   unsigned RegRt = fieldFromInstruction(Insn, 4, 3);
2486   if (DecodeGPRMM16MovePRegisterClass(Inst, RegRt, Address, Decoder) ==
2487       MCDisassembler::Fail)
2488     return MCDisassembler::Fail;
2489 
2490   return MCDisassembler::Success;
2491 }
2492 
2493 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned RegPair,
2494                                        uint64_t Address, const void *Decoder) {
2495   switch (RegPair) {
2496   default:
2497     return MCDisassembler::Fail;
2498   case 0:
2499     Inst.addOperand(MCOperand::createReg(Mips::A1));
2500     Inst.addOperand(MCOperand::createReg(Mips::A2));
2501     break;
2502   case 1:
2503     Inst.addOperand(MCOperand::createReg(Mips::A1));
2504     Inst.addOperand(MCOperand::createReg(Mips::A3));
2505     break;
2506   case 2:
2507     Inst.addOperand(MCOperand::createReg(Mips::A2));
2508     Inst.addOperand(MCOperand::createReg(Mips::A3));
2509     break;
2510   case 3:
2511     Inst.addOperand(MCOperand::createReg(Mips::A0));
2512     Inst.addOperand(MCOperand::createReg(Mips::S5));
2513     break;
2514   case 4:
2515     Inst.addOperand(MCOperand::createReg(Mips::A0));
2516     Inst.addOperand(MCOperand::createReg(Mips::S6));
2517     break;
2518   case 5:
2519     Inst.addOperand(MCOperand::createReg(Mips::A0));
2520     Inst.addOperand(MCOperand::createReg(Mips::A1));
2521     break;
2522   case 6:
2523     Inst.addOperand(MCOperand::createReg(Mips::A0));
2524     Inst.addOperand(MCOperand::createReg(Mips::A2));
2525     break;
2526   case 7:
2527     Inst.addOperand(MCOperand::createReg(Mips::A0));
2528     Inst.addOperand(MCOperand::createReg(Mips::A3));
2529     break;
2530   }
2531 
2532   return MCDisassembler::Success;
2533 }
2534 
2535 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
2536                                      uint64_t Address, const void *Decoder) {
2537   Inst.addOperand(MCOperand::createImm(SignExtend32<25>(Insn << 2)));
2538   return MCDisassembler::Success;
2539 }
2540 
2541 template <typename InsnType>
2542 static DecodeStatus DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn,
2543   uint64_t Address,
2544   const void *Decoder) {
2545   // We have:
2546   //    0b000111 ttttt sssss iiiiiiiiiiiiiiii
2547   //      Invalid      if rt == 0
2548   //      BGTZALC_MMR6 if rs == 0 && rt != 0
2549   //      BLTZALC_MMR6 if rs != 0 && rs == rt
2550   //      BLTUC_MMR6   if rs != 0 && rs != rt
2551 
2552   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2553   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2554   InsnType Imm = 0;
2555   bool HasRs = false;
2556   bool HasRt = false;
2557 
2558   if (Rt == 0)
2559     return MCDisassembler::Fail;
2560   else if (Rs == 0) {
2561     MI.setOpcode(Mips::BGTZALC_MMR6);
2562     HasRt = true;
2563     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2564   }
2565   else if (Rs == Rt) {
2566     MI.setOpcode(Mips::BLTZALC_MMR6);
2567     HasRs = true;
2568     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2569   }
2570   else {
2571     MI.setOpcode(Mips::BLTUC_MMR6);
2572     HasRs = true;
2573     HasRt = true;
2574     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
2575   }
2576 
2577   if (HasRs)
2578     MI.addOperand(
2579     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2580 
2581   if (HasRt)
2582     MI.addOperand(
2583     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2584 
2585   MI.addOperand(MCOperand::createImm(Imm));
2586 
2587   return MCDisassembler::Success;
2588 }
2589 
2590 template <typename InsnType>
2591 static DecodeStatus DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn,
2592   uint64_t Address,
2593   const void *Decoder) {
2594   // We have:
2595   //    0b000110 ttttt sssss iiiiiiiiiiiiiiii
2596   //      Invalid        if rt == 0
2597   //      BLEZALC_MMR6   if rs == 0  && rt != 0
2598   //      BGEZALC_MMR6   if rs == rt && rt != 0
2599   //      BGEUC_MMR6     if rs != rt && rs != 0  && rt != 0
2600 
2601   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2602   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2603   InsnType Imm = 0;
2604   bool HasRs = false;
2605 
2606   if (Rt == 0)
2607     return MCDisassembler::Fail;
2608   else if (Rs == 0) {
2609     MI.setOpcode(Mips::BLEZALC_MMR6);
2610     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2611   }
2612   else if (Rs == Rt) {
2613     MI.setOpcode(Mips::BGEZALC_MMR6);
2614     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2615   }
2616   else {
2617     HasRs = true;
2618     MI.setOpcode(Mips::BGEUC_MMR6);
2619     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
2620   }
2621 
2622   if (HasRs)
2623     MI.addOperand(
2624     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2625   MI.addOperand(
2626     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2627 
2628   MI.addOperand(MCOperand::createImm(Imm));
2629 
2630   return MCDisassembler::Success;
2631 }
2632