1 //===- MipsDisassembler.cpp - Disassembler for Mips -------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is part of the Mips Disassembler.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "Mips.h"
15 #include "MipsRegisterInfo.h"
16 #include "MipsSubtarget.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCDisassembler.h"
19 #include "llvm/MC/MCFixedLenDisassembler.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/MC/MCSubtargetInfo.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/TargetRegistry.h"
24 
25 using namespace llvm;
26 
27 #define DEBUG_TYPE "mips-disassembler"
28 
29 typedef MCDisassembler::DecodeStatus DecodeStatus;
30 
31 namespace {
32 
33 class MipsDisassembler : public MCDisassembler {
34   bool IsMicroMips;
35   bool IsBigEndian;
36 public:
37   MipsDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx, bool IsBigEndian)
38       : MCDisassembler(STI, Ctx),
39         IsMicroMips(STI.getFeatureBits()[Mips::FeatureMicroMips]),
40         IsBigEndian(IsBigEndian) {}
41 
42   bool hasMips3() const { return STI.getFeatureBits()[Mips::FeatureMips3]; }
43   bool hasMips32() const { return STI.getFeatureBits()[Mips::FeatureMips32]; }
44   bool hasMips32r6() const {
45     return STI.getFeatureBits()[Mips::FeatureMips32r6];
46   }
47 
48   bool isGP64() const { return STI.getFeatureBits()[Mips::FeatureGP64Bit]; }
49 
50   bool hasCnMips() const { return STI.getFeatureBits()[Mips::FeatureCnMips]; }
51 
52   bool hasCOP3() const {
53     // Only present in MIPS-I and MIPS-II
54     return !hasMips32() && !hasMips3();
55   }
56 
57   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
58                               ArrayRef<uint8_t> Bytes, uint64_t Address,
59                               raw_ostream &VStream,
60                               raw_ostream &CStream) const override;
61 };
62 
63 } // end anonymous namespace
64 
65 // Forward declare these because the autogenerated code will reference them.
66 // Definitions are further down.
67 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
68                                              unsigned RegNo,
69                                              uint64_t Address,
70                                              const void *Decoder);
71 
72 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
73                                                  unsigned RegNo,
74                                                  uint64_t Address,
75                                                  const void *Decoder);
76 
77 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
78                                                unsigned RegNo,
79                                                uint64_t Address,
80                                                const void *Decoder);
81 
82 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
83                                                    unsigned RegNo,
84                                                    uint64_t Address,
85                                                    const void *Decoder);
86 
87 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
88                                                     unsigned RegNo,
89                                                     uint64_t Address,
90                                                     const void *Decoder);
91 
92 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
93                                              unsigned RegNo,
94                                              uint64_t Address,
95                                              const void *Decoder);
96 
97 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
98                                            unsigned Insn,
99                                            uint64_t Address,
100                                            const void *Decoder);
101 
102 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
103                                             unsigned RegNo,
104                                             uint64_t Address,
105                                             const void *Decoder);
106 
107 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
108                                              unsigned RegNo,
109                                              uint64_t Address,
110                                              const void *Decoder);
111 
112 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
113                                              unsigned RegNo,
114                                              uint64_t Address,
115                                              const void *Decoder);
116 
117 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
118                                            unsigned RegNo,
119                                            uint64_t Address,
120                                            const void *Decoder);
121 
122 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
123                                            unsigned RegNo,
124                                            uint64_t Address,
125                                            const void *Decoder);
126 
127 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
128                                              uint64_t Address,
129                                              const void *Decoder);
130 
131 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
132                                               unsigned Insn,
133                                               uint64_t Address,
134                                               const void *Decoder);
135 
136 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
137                                               unsigned RegNo,
138                                               uint64_t Address,
139                                               const void *Decoder);
140 
141 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
142                                                 unsigned RegNo,
143                                                 uint64_t Address,
144                                                 const void *Decoder);
145 
146 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
147                                                unsigned RegNo,
148                                                uint64_t Address,
149                                                const void *Decoder);
150 
151 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
152                                                unsigned RegNo,
153                                                uint64_t Address,
154                                                const void *Decoder);
155 
156 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
157                                                unsigned RegNo,
158                                                uint64_t Address,
159                                                const void *Decoder);
160 
161 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
162                                                unsigned RegNo,
163                                                uint64_t Address,
164                                                const void *Decoder);
165 
166 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
167                                                unsigned RegNo,
168                                                uint64_t Address,
169                                                const void *Decoder);
170 
171 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
172                                                unsigned RegNo,
173                                                uint64_t Address,
174                                                const void *Decoder);
175 
176 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
177                                                unsigned RegNo,
178                                                uint64_t Address,
179                                                const void *Decoder);
180 
181 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
182                                             unsigned RegNo,
183                                             uint64_t Address,
184                                             const void *Decoder);
185 
186 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
187                                             unsigned RegNo,
188                                             uint64_t Address,
189                                             const void *Decoder);
190 
191 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
192                                        unsigned Offset,
193                                        uint64_t Address,
194                                        const void *Decoder);
195 
196 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
197                                      unsigned Insn,
198                                      uint64_t Address,
199                                      const void *Decoder);
200 
201 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
202                                          unsigned Offset,
203                                          uint64_t Address,
204                                          const void *Decoder);
205 
206 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
207                                          unsigned Offset,
208                                          uint64_t Address,
209                                          const void *Decoder);
210 
211 // DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
212 // shifted left by 1 bit.
213 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
214                                           unsigned Offset,
215                                           uint64_t Address,
216                                           const void *Decoder);
217 
218 // DecodeBranchTarget10MM - Decode microMIPS branch offset, which is
219 // shifted left by 1 bit.
220 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
221                                            unsigned Offset,
222                                            uint64_t Address,
223                                            const void *Decoder);
224 
225 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
226 // shifted left by 1 bit.
227 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
228                                          unsigned Offset,
229                                          uint64_t Address,
230                                          const void *Decoder);
231 
232 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
233 // shifted left by 1 bit.
234 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
235                                        unsigned Insn,
236                                        uint64_t Address,
237                                        const void *Decoder);
238 
239 static DecodeStatus DecodeMem(MCInst &Inst,
240                               unsigned Insn,
241                               uint64_t Address,
242                               const void *Decoder);
243 
244 static DecodeStatus DecodeCacheOp(MCInst &Inst,
245                               unsigned Insn,
246                               uint64_t Address,
247                               const void *Decoder);
248 
249 static DecodeStatus DecodeCacheOpR6(MCInst &Inst,
250                                     unsigned Insn,
251                                     uint64_t Address,
252                                     const void *Decoder);
253 
254 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
255                                     unsigned Insn,
256                                     uint64_t Address,
257                                     const void *Decoder);
258 
259 static DecodeStatus DecodeSyncI(MCInst &Inst,
260                                 unsigned Insn,
261                                 uint64_t Address,
262                                 const void *Decoder);
263 
264 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
265                                     uint64_t Address, const void *Decoder);
266 
267 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
268                                     unsigned Insn,
269                                     uint64_t Address,
270                                     const void *Decoder);
271 
272 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
273                                           unsigned Insn,
274                                           uint64_t Address,
275                                           const void *Decoder);
276 
277 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
278                                           unsigned Insn,
279                                           uint64_t Address,
280                                           const void *Decoder);
281 
282 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
283                                                unsigned Insn,
284                                                uint64_t Address,
285                                                const void *Decoder);
286 
287 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
288                                      unsigned Insn,
289                                      uint64_t Address,
290                                      const void *Decoder);
291 
292 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
293                                      unsigned Insn,
294                                      uint64_t Address,
295                                      const void *Decoder);
296 
297 static DecodeStatus DecodeFMem(MCInst &Inst, unsigned Insn,
298                                uint64_t Address,
299                                const void *Decoder);
300 
301 static DecodeStatus DecodeFMem2(MCInst &Inst, unsigned Insn,
302                                uint64_t Address,
303                                const void *Decoder);
304 
305 static DecodeStatus DecodeFMem3(MCInst &Inst, unsigned Insn,
306                                uint64_t Address,
307                                const void *Decoder);
308 
309 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst, unsigned Insn,
310                                uint64_t Address,
311                                const void *Decoder);
312 
313 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
314                                        unsigned Insn,
315                                        uint64_t Address,
316                                        const void *Decoder);
317 
318 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
319                                        unsigned Value,
320                                        uint64_t Address,
321                                        const void *Decoder);
322 
323 static DecodeStatus DecodeUImm6Lsl2(MCInst &Inst,
324                                     unsigned Value,
325                                     uint64_t Address,
326                                     const void *Decoder);
327 
328 static DecodeStatus DecodeLiSimm7(MCInst &Inst,
329                                   unsigned Value,
330                                   uint64_t Address,
331                                   const void *Decoder);
332 
333 static DecodeStatus DecodeSimm4(MCInst &Inst,
334                                 unsigned Value,
335                                 uint64_t Address,
336                                 const void *Decoder);
337 
338 static DecodeStatus DecodeSimm16(MCInst &Inst,
339                                  unsigned Insn,
340                                  uint64_t Address,
341                                  const void *Decoder);
342 
343 // Decode the immediate field of an LSA instruction which
344 // is off by one.
345 static DecodeStatus DecodeLSAImm(MCInst &Inst,
346                                  unsigned Insn,
347                                  uint64_t Address,
348                                  const void *Decoder);
349 
350 static DecodeStatus DecodeInsSize(MCInst &Inst,
351                                   unsigned Insn,
352                                   uint64_t Address,
353                                   const void *Decoder);
354 
355 static DecodeStatus DecodeExtSize(MCInst &Inst,
356                                   unsigned Insn,
357                                   uint64_t Address,
358                                   const void *Decoder);
359 
360 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
361                                      uint64_t Address, const void *Decoder);
362 
363 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
364                                      uint64_t Address, const void *Decoder);
365 
366 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
367                                   uint64_t Address, const void *Decoder);
368 
369 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
370                                     uint64_t Address, const void *Decoder);
371 
372 static DecodeStatus DecodeUImm5lsl2(MCInst &Inst, unsigned Insn,
373                                    uint64_t Address, const void *Decoder);
374 
375 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
376                                      uint64_t Address, const void *Decoder);
377 
378 /// INSVE_[BHWD] have an implicit operand that the generated decoder doesn't
379 /// handle.
380 template <typename InsnType>
381 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
382                                    const void *Decoder);
383 
384 template <typename InsnType>
385 static DecodeStatus
386 DecodeAddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
387                       const void *Decoder);
388 
389 template <typename InsnType>
390 static DecodeStatus
391 DecodeDaddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
392                        const void *Decoder);
393 
394 template <typename InsnType>
395 static DecodeStatus
396 DecodeBlezlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
397                        const void *Decoder);
398 
399 template <typename InsnType>
400 static DecodeStatus
401 DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
402                        const void *Decoder);
403 
404 template <typename InsnType>
405 static DecodeStatus
406 DecodeBgtzGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
407                       const void *Decoder);
408 
409 template <typename InsnType>
410 static DecodeStatus
411 DecodeBlezGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
412                        const void *Decoder);
413 
414 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
415                                          uint64_t Address,
416                                          const void *Decoder);
417 
418 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
419                                            uint64_t Address,
420                                            const void *Decoder);
421 
422 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
423                                        uint64_t Address,
424                                        const void *Decoder);
425 
426 namespace llvm {
427 extern Target TheMipselTarget, TheMipsTarget, TheMips64Target,
428               TheMips64elTarget;
429 }
430 
431 static MCDisassembler *createMipsDisassembler(
432                        const Target &T,
433                        const MCSubtargetInfo &STI,
434                        MCContext &Ctx) {
435   return new MipsDisassembler(STI, Ctx, true);
436 }
437 
438 static MCDisassembler *createMipselDisassembler(
439                        const Target &T,
440                        const MCSubtargetInfo &STI,
441                        MCContext &Ctx) {
442   return new MipsDisassembler(STI, Ctx, false);
443 }
444 
445 extern "C" void LLVMInitializeMipsDisassembler() {
446   // Register the disassembler.
447   TargetRegistry::RegisterMCDisassembler(TheMipsTarget,
448                                          createMipsDisassembler);
449   TargetRegistry::RegisterMCDisassembler(TheMipselTarget,
450                                          createMipselDisassembler);
451   TargetRegistry::RegisterMCDisassembler(TheMips64Target,
452                                          createMipsDisassembler);
453   TargetRegistry::RegisterMCDisassembler(TheMips64elTarget,
454                                          createMipselDisassembler);
455 }
456 
457 #include "MipsGenDisassemblerTables.inc"
458 
459 static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) {
460   const MipsDisassembler *Dis = static_cast<const MipsDisassembler*>(D);
461   const MCRegisterInfo *RegInfo = Dis->getContext().getRegisterInfo();
462   return *(RegInfo->getRegClass(RC).begin() + RegNo);
463 }
464 
465 template <typename InsnType>
466 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
467                                    const void *Decoder) {
468   typedef DecodeStatus (*DecodeFN)(MCInst &, unsigned, uint64_t, const void *);
469   // The size of the n field depends on the element size
470   // The register class also depends on this.
471   InsnType tmp = fieldFromInstruction(insn, 17, 5);
472   unsigned NSize = 0;
473   DecodeFN RegDecoder = nullptr;
474   if ((tmp & 0x18) == 0x00) { // INSVE_B
475     NSize = 4;
476     RegDecoder = DecodeMSA128BRegisterClass;
477   } else if ((tmp & 0x1c) == 0x10) { // INSVE_H
478     NSize = 3;
479     RegDecoder = DecodeMSA128HRegisterClass;
480   } else if ((tmp & 0x1e) == 0x18) { // INSVE_W
481     NSize = 2;
482     RegDecoder = DecodeMSA128WRegisterClass;
483   } else if ((tmp & 0x1f) == 0x1c) { // INSVE_D
484     NSize = 1;
485     RegDecoder = DecodeMSA128DRegisterClass;
486   } else
487     llvm_unreachable("Invalid encoding");
488 
489   assert(NSize != 0 && RegDecoder != nullptr);
490 
491   // $wd
492   tmp = fieldFromInstruction(insn, 6, 5);
493   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
494     return MCDisassembler::Fail;
495   // $wd_in
496   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
497     return MCDisassembler::Fail;
498   // $n
499   tmp = fieldFromInstruction(insn, 16, NSize);
500   MI.addOperand(MCOperand::createImm(tmp));
501   // $ws
502   tmp = fieldFromInstruction(insn, 11, 5);
503   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
504     return MCDisassembler::Fail;
505   // $n2
506   MI.addOperand(MCOperand::createImm(0));
507 
508   return MCDisassembler::Success;
509 }
510 
511 template <typename InsnType>
512 static DecodeStatus DecodeAddiGroupBranch(MCInst &MI, InsnType insn,
513                                           uint64_t Address,
514                                           const void *Decoder) {
515   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
516   // (otherwise we would have matched the ADDI instruction from the earlier
517   // ISA's instead).
518   //
519   // We have:
520   //    0b001000 sssss ttttt iiiiiiiiiiiiiiii
521   //      BOVC if rs >= rt
522   //      BEQZALC if rs == 0 && rt != 0
523   //      BEQC if rs < rt && rs != 0
524 
525   InsnType Rs = fieldFromInstruction(insn, 21, 5);
526   InsnType Rt = fieldFromInstruction(insn, 16, 5);
527   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
528   bool HasRs = false;
529 
530   if (Rs >= Rt) {
531     MI.setOpcode(Mips::BOVC);
532     HasRs = true;
533   } else if (Rs != 0 && Rs < Rt) {
534     MI.setOpcode(Mips::BEQC);
535     HasRs = true;
536   } else
537     MI.setOpcode(Mips::BEQZALC);
538 
539   if (HasRs)
540     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
541                                        Rs)));
542 
543   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
544                                      Rt)));
545   MI.addOperand(MCOperand::createImm(Imm));
546 
547   return MCDisassembler::Success;
548 }
549 
550 template <typename InsnType>
551 static DecodeStatus DecodeDaddiGroupBranch(MCInst &MI, InsnType insn,
552                                            uint64_t Address,
553                                            const void *Decoder) {
554   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
555   // (otherwise we would have matched the ADDI instruction from the earlier
556   // ISA's instead).
557   //
558   // We have:
559   //    0b011000 sssss ttttt iiiiiiiiiiiiiiii
560   //      BNVC if rs >= rt
561   //      BNEZALC if rs == 0 && rt != 0
562   //      BNEC if rs < rt && rs != 0
563 
564   InsnType Rs = fieldFromInstruction(insn, 21, 5);
565   InsnType Rt = fieldFromInstruction(insn, 16, 5);
566   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
567   bool HasRs = false;
568 
569   if (Rs >= Rt) {
570     MI.setOpcode(Mips::BNVC);
571     HasRs = true;
572   } else if (Rs != 0 && Rs < Rt) {
573     MI.setOpcode(Mips::BNEC);
574     HasRs = true;
575   } else
576     MI.setOpcode(Mips::BNEZALC);
577 
578   if (HasRs)
579     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
580                                        Rs)));
581 
582   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
583                                      Rt)));
584   MI.addOperand(MCOperand::createImm(Imm));
585 
586   return MCDisassembler::Success;
587 }
588 
589 template <typename InsnType>
590 static DecodeStatus DecodeBlezlGroupBranch(MCInst &MI, InsnType insn,
591                                            uint64_t Address,
592                                            const void *Decoder) {
593   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
594   // (otherwise we would have matched the BLEZL instruction from the earlier
595   // ISA's instead).
596   //
597   // We have:
598   //    0b010110 sssss ttttt iiiiiiiiiiiiiiii
599   //      Invalid if rs == 0
600   //      BLEZC   if rs == 0  && rt != 0
601   //      BGEZC   if rs == rt && rt != 0
602   //      BGEC    if rs != rt && rs != 0  && rt != 0
603 
604   InsnType Rs = fieldFromInstruction(insn, 21, 5);
605   InsnType Rt = fieldFromInstruction(insn, 16, 5);
606   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
607   bool HasRs = false;
608 
609   if (Rt == 0)
610     return MCDisassembler::Fail;
611   else if (Rs == 0)
612     MI.setOpcode(Mips::BLEZC);
613   else if (Rs == Rt)
614     MI.setOpcode(Mips::BGEZC);
615   else {
616     HasRs = true;
617     MI.setOpcode(Mips::BGEC);
618   }
619 
620   if (HasRs)
621     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
622                                        Rs)));
623 
624   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
625                                      Rt)));
626 
627   MI.addOperand(MCOperand::createImm(Imm));
628 
629   return MCDisassembler::Success;
630 }
631 
632 template <typename InsnType>
633 static DecodeStatus DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn,
634                                            uint64_t Address,
635                                            const void *Decoder) {
636   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
637   // (otherwise we would have matched the BGTZL instruction from the earlier
638   // ISA's instead).
639   //
640   // We have:
641   //    0b010111 sssss ttttt iiiiiiiiiiiiiiii
642   //      Invalid if rs == 0
643   //      BGTZC   if rs == 0  && rt != 0
644   //      BLTZC   if rs == rt && rt != 0
645   //      BLTC    if rs != rt && rs != 0  && rt != 0
646 
647   bool HasRs = false;
648 
649   InsnType Rs = fieldFromInstruction(insn, 21, 5);
650   InsnType Rt = fieldFromInstruction(insn, 16, 5);
651   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
652 
653   if (Rt == 0)
654     return MCDisassembler::Fail;
655   else if (Rs == 0)
656     MI.setOpcode(Mips::BGTZC);
657   else if (Rs == Rt)
658     MI.setOpcode(Mips::BLTZC);
659   else {
660     MI.setOpcode(Mips::BLTC);
661     HasRs = true;
662   }
663 
664   if (HasRs)
665     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
666                                               Rs)));
667 
668   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
669                                      Rt)));
670 
671   MI.addOperand(MCOperand::createImm(Imm));
672 
673   return MCDisassembler::Success;
674 }
675 
676 template <typename InsnType>
677 static DecodeStatus DecodeBgtzGroupBranch(MCInst &MI, InsnType insn,
678                                           uint64_t Address,
679                                           const void *Decoder) {
680   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
681   // (otherwise we would have matched the BGTZ instruction from the earlier
682   // ISA's instead).
683   //
684   // We have:
685   //    0b000111 sssss ttttt iiiiiiiiiiiiiiii
686   //      BGTZ    if rt == 0
687   //      BGTZALC if rs == 0 && rt != 0
688   //      BLTZALC if rs != 0 && rs == rt
689   //      BLTUC   if rs != 0 && rs != rt
690 
691   InsnType Rs = fieldFromInstruction(insn, 21, 5);
692   InsnType Rt = fieldFromInstruction(insn, 16, 5);
693   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
694   bool HasRs = false;
695   bool HasRt = false;
696 
697   if (Rt == 0) {
698     MI.setOpcode(Mips::BGTZ);
699     HasRs = true;
700   } else if (Rs == 0) {
701     MI.setOpcode(Mips::BGTZALC);
702     HasRt = true;
703   } else if (Rs == Rt) {
704     MI.setOpcode(Mips::BLTZALC);
705     HasRs = true;
706   } else {
707     MI.setOpcode(Mips::BLTUC);
708     HasRs = true;
709     HasRt = true;
710   }
711 
712   if (HasRs)
713     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
714                                        Rs)));
715 
716   if (HasRt)
717     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
718                                        Rt)));
719 
720   MI.addOperand(MCOperand::createImm(Imm));
721 
722   return MCDisassembler::Success;
723 }
724 
725 template <typename InsnType>
726 static DecodeStatus DecodeBlezGroupBranch(MCInst &MI, InsnType insn,
727                                            uint64_t Address,
728                                            const void *Decoder) {
729   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
730   // (otherwise we would have matched the BLEZL instruction from the earlier
731   // ISA's instead).
732   //
733   // We have:
734   //    0b000110 sssss ttttt iiiiiiiiiiiiiiii
735   //      Invalid   if rs == 0
736   //      BLEZALC   if rs == 0  && rt != 0
737   //      BGEZALC   if rs == rt && rt != 0
738   //      BGEUC     if rs != rt && rs != 0  && rt != 0
739 
740   InsnType Rs = fieldFromInstruction(insn, 21, 5);
741   InsnType Rt = fieldFromInstruction(insn, 16, 5);
742   InsnType Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4;
743   bool HasRs = false;
744 
745   if (Rt == 0)
746     return MCDisassembler::Fail;
747   else if (Rs == 0)
748     MI.setOpcode(Mips::BLEZALC);
749   else if (Rs == Rt)
750     MI.setOpcode(Mips::BGEZALC);
751   else {
752     HasRs = true;
753     MI.setOpcode(Mips::BGEUC);
754   }
755 
756   if (HasRs)
757     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
758                                        Rs)));
759   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
760                                      Rt)));
761 
762   MI.addOperand(MCOperand::createImm(Imm));
763 
764   return MCDisassembler::Success;
765 }
766 
767 /// Read two bytes from the ArrayRef and return 16 bit halfword sorted
768 /// according to the given endianess.
769 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
770                                       uint64_t &Size, uint32_t &Insn,
771                                       bool IsBigEndian) {
772   // We want to read exactly 2 Bytes of data.
773   if (Bytes.size() < 2) {
774     Size = 0;
775     return MCDisassembler::Fail;
776   }
777 
778   if (IsBigEndian) {
779     Insn = (Bytes[0] << 8) | Bytes[1];
780   } else {
781     Insn = (Bytes[1] << 8) | Bytes[0];
782   }
783 
784   return MCDisassembler::Success;
785 }
786 
787 /// Read four bytes from the ArrayRef and return 32 bit word sorted
788 /// according to the given endianess
789 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
790                                       uint64_t &Size, uint32_t &Insn,
791                                       bool IsBigEndian, bool IsMicroMips) {
792   // We want to read exactly 4 Bytes of data.
793   if (Bytes.size() < 4) {
794     Size = 0;
795     return MCDisassembler::Fail;
796   }
797 
798   // High 16 bits of a 32-bit microMIPS instruction (where the opcode is)
799   // always precede the low 16 bits in the instruction stream (that is, they
800   // are placed at lower addresses in the instruction stream).
801   //
802   // microMIPS byte ordering:
803   //   Big-endian:    0 | 1 | 2 | 3
804   //   Little-endian: 1 | 0 | 3 | 2
805 
806   if (IsBigEndian) {
807     // Encoded as a big-endian 32-bit word in the stream.
808     Insn =
809         (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) | (Bytes[0] << 24);
810   } else {
811     if (IsMicroMips) {
812       Insn = (Bytes[2] << 0) | (Bytes[3] << 8) | (Bytes[0] << 16) |
813              (Bytes[1] << 24);
814     } else {
815       Insn = (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
816              (Bytes[3] << 24);
817     }
818   }
819 
820   return MCDisassembler::Success;
821 }
822 
823 DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
824                                               ArrayRef<uint8_t> Bytes,
825                                               uint64_t Address,
826                                               raw_ostream &VStream,
827                                               raw_ostream &CStream) const {
828   uint32_t Insn;
829   DecodeStatus Result;
830 
831   if (IsMicroMips) {
832     Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian);
833 
834     DEBUG(dbgs() << "Trying MicroMips16 table (16-bit instructions):\n");
835     // Calling the auto-generated decoder function.
836     Result = decodeInstruction(DecoderTableMicroMips16, Instr, Insn, Address,
837                                this, STI);
838     if (Result != MCDisassembler::Fail) {
839       Size = 2;
840       return Result;
841     }
842 
843     Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, true);
844     if (Result == MCDisassembler::Fail)
845       return MCDisassembler::Fail;
846 
847     if (hasMips32r6()) {
848       DEBUG(dbgs() << "Trying MicroMips32r632 table (32-bit instructions):\n");
849       // Calling the auto-generated decoder function.
850       Result = decodeInstruction(DecoderTableMicroMips32r632, Instr, Insn, Address,
851                                  this, STI);
852     } else {
853       DEBUG(dbgs() << "Trying MicroMips32 table (32-bit instructions):\n");
854       // Calling the auto-generated decoder function.
855       Result = decodeInstruction(DecoderTableMicroMips32, Instr, Insn, Address,
856                                  this, STI);
857     }
858     if (Result != MCDisassembler::Fail) {
859       Size = 4;
860       return Result;
861     }
862     return MCDisassembler::Fail;
863   }
864 
865   Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
866   if (Result == MCDisassembler::Fail)
867     return MCDisassembler::Fail;
868 
869   if (hasCOP3()) {
870     DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n");
871     Result =
872         decodeInstruction(DecoderTableCOP3_32, Instr, Insn, Address, this, STI);
873     if (Result != MCDisassembler::Fail) {
874       Size = 4;
875       return Result;
876     }
877   }
878 
879   if (hasMips32r6() && isGP64()) {
880     DEBUG(dbgs() << "Trying Mips32r6_64r6 (GPR64) table (32-bit opcodes):\n");
881     Result = decodeInstruction(DecoderTableMips32r6_64r6_GP6432, Instr, Insn,
882                                Address, this, STI);
883     if (Result != MCDisassembler::Fail) {
884       Size = 4;
885       return Result;
886     }
887   }
888 
889   if (hasMips32r6()) {
890     DEBUG(dbgs() << "Trying Mips32r6_64r6 table (32-bit opcodes):\n");
891     Result = decodeInstruction(DecoderTableMips32r6_64r632, Instr, Insn,
892                                Address, this, STI);
893     if (Result != MCDisassembler::Fail) {
894       Size = 4;
895       return Result;
896     }
897   }
898 
899   if (hasCnMips()) {
900     DEBUG(dbgs() << "Trying CnMips table (32-bit opcodes):\n");
901     Result = decodeInstruction(DecoderTableCnMips32, Instr, Insn,
902                                Address, this, STI);
903     if (Result != MCDisassembler::Fail) {
904       Size = 4;
905       return Result;
906     }
907   }
908 
909   if (isGP64()) {
910     DEBUG(dbgs() << "Trying Mips64 (GPR64) table (32-bit opcodes):\n");
911     Result = decodeInstruction(DecoderTableMips6432, Instr, Insn,
912                                Address, this, STI);
913     if (Result != MCDisassembler::Fail) {
914       Size = 4;
915       return Result;
916     }
917   }
918 
919   DEBUG(dbgs() << "Trying Mips table (32-bit opcodes):\n");
920   // Calling the auto-generated decoder function.
921   Result =
922       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
923   if (Result != MCDisassembler::Fail) {
924     Size = 4;
925     return Result;
926   }
927 
928   return MCDisassembler::Fail;
929 }
930 
931 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
932                                                  unsigned RegNo,
933                                                  uint64_t Address,
934                                                  const void *Decoder) {
935 
936   return MCDisassembler::Fail;
937 
938 }
939 
940 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
941                                              unsigned RegNo,
942                                              uint64_t Address,
943                                              const void *Decoder) {
944 
945   if (RegNo > 31)
946     return MCDisassembler::Fail;
947 
948   unsigned Reg = getReg(Decoder, Mips::GPR64RegClassID, RegNo);
949   Inst.addOperand(MCOperand::createReg(Reg));
950   return MCDisassembler::Success;
951 }
952 
953 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
954                                                unsigned RegNo,
955                                                uint64_t Address,
956                                                const void *Decoder) {
957   if (RegNo > 7)
958     return MCDisassembler::Fail;
959   unsigned Reg = getReg(Decoder, Mips::GPRMM16RegClassID, RegNo);
960   Inst.addOperand(MCOperand::createReg(Reg));
961   return MCDisassembler::Success;
962 }
963 
964 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
965                                                    unsigned RegNo,
966                                                    uint64_t Address,
967                                                    const void *Decoder) {
968   if (RegNo > 7)
969     return MCDisassembler::Fail;
970   unsigned Reg = getReg(Decoder, Mips::GPRMM16ZeroRegClassID, RegNo);
971   Inst.addOperand(MCOperand::createReg(Reg));
972   return MCDisassembler::Success;
973 }
974 
975 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
976                                                     unsigned RegNo,
977                                                     uint64_t Address,
978                                                     const void *Decoder) {
979   if (RegNo > 7)
980     return MCDisassembler::Fail;
981   unsigned Reg = getReg(Decoder, Mips::GPRMM16MovePRegClassID, RegNo);
982   Inst.addOperand(MCOperand::createReg(Reg));
983   return MCDisassembler::Success;
984 }
985 
986 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
987                                              unsigned RegNo,
988                                              uint64_t Address,
989                                              const void *Decoder) {
990   if (RegNo > 31)
991     return MCDisassembler::Fail;
992   unsigned Reg = getReg(Decoder, Mips::GPR32RegClassID, RegNo);
993   Inst.addOperand(MCOperand::createReg(Reg));
994   return MCDisassembler::Success;
995 }
996 
997 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
998                                            unsigned RegNo,
999                                            uint64_t Address,
1000                                            const void *Decoder) {
1001   if (static_cast<const MipsDisassembler *>(Decoder)->isGP64())
1002     return DecodeGPR64RegisterClass(Inst, RegNo, Address, Decoder);
1003 
1004   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1005 }
1006 
1007 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
1008                                             unsigned RegNo,
1009                                             uint64_t Address,
1010                                             const void *Decoder) {
1011   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1012 }
1013 
1014 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
1015                                              unsigned RegNo,
1016                                              uint64_t Address,
1017                                              const void *Decoder) {
1018   if (RegNo > 31)
1019     return MCDisassembler::Fail;
1020 
1021   unsigned Reg = getReg(Decoder, Mips::FGR64RegClassID, RegNo);
1022   Inst.addOperand(MCOperand::createReg(Reg));
1023   return MCDisassembler::Success;
1024 }
1025 
1026 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
1027                                              unsigned RegNo,
1028                                              uint64_t Address,
1029                                              const void *Decoder) {
1030   if (RegNo > 31)
1031     return MCDisassembler::Fail;
1032 
1033   unsigned Reg = getReg(Decoder, Mips::FGR32RegClassID, RegNo);
1034   Inst.addOperand(MCOperand::createReg(Reg));
1035   return MCDisassembler::Success;
1036 }
1037 
1038 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
1039                                            unsigned RegNo,
1040                                            uint64_t Address,
1041                                            const void *Decoder) {
1042   if (RegNo > 31)
1043     return MCDisassembler::Fail;
1044   unsigned Reg = getReg(Decoder, Mips::CCRRegClassID, RegNo);
1045   Inst.addOperand(MCOperand::createReg(Reg));
1046   return MCDisassembler::Success;
1047 }
1048 
1049 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
1050                                            unsigned RegNo,
1051                                            uint64_t Address,
1052                                            const void *Decoder) {
1053   if (RegNo > 7)
1054     return MCDisassembler::Fail;
1055   unsigned Reg = getReg(Decoder, Mips::FCCRegClassID, RegNo);
1056   Inst.addOperand(MCOperand::createReg(Reg));
1057   return MCDisassembler::Success;
1058 }
1059 
1060 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
1061                                              uint64_t Address,
1062                                              const void *Decoder) {
1063   if (RegNo > 31)
1064     return MCDisassembler::Fail;
1065 
1066   unsigned Reg = getReg(Decoder, Mips::FGRCCRegClassID, RegNo);
1067   Inst.addOperand(MCOperand::createReg(Reg));
1068   return MCDisassembler::Success;
1069 }
1070 
1071 static DecodeStatus DecodeMem(MCInst &Inst,
1072                               unsigned Insn,
1073                               uint64_t Address,
1074                               const void *Decoder) {
1075   int Offset = SignExtend32<16>(Insn & 0xffff);
1076   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1077   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1078 
1079   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1080   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1081 
1082   if(Inst.getOpcode() == Mips::SC ||
1083      Inst.getOpcode() == Mips::SCD){
1084     Inst.addOperand(MCOperand::createReg(Reg));
1085   }
1086 
1087   Inst.addOperand(MCOperand::createReg(Reg));
1088   Inst.addOperand(MCOperand::createReg(Base));
1089   Inst.addOperand(MCOperand::createImm(Offset));
1090 
1091   return MCDisassembler::Success;
1092 }
1093 
1094 static DecodeStatus DecodeCacheOp(MCInst &Inst,
1095                               unsigned Insn,
1096                               uint64_t Address,
1097                               const void *Decoder) {
1098   int Offset = SignExtend32<16>(Insn & 0xffff);
1099   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1100   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1101 
1102   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1103 
1104   Inst.addOperand(MCOperand::createReg(Base));
1105   Inst.addOperand(MCOperand::createImm(Offset));
1106   Inst.addOperand(MCOperand::createImm(Hint));
1107 
1108   return MCDisassembler::Success;
1109 }
1110 
1111 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
1112                                     unsigned Insn,
1113                                     uint64_t Address,
1114                                     const void *Decoder) {
1115   int Offset = SignExtend32<12>(Insn & 0xfff);
1116   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1117   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1118 
1119   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1120 
1121   Inst.addOperand(MCOperand::createReg(Base));
1122   Inst.addOperand(MCOperand::createImm(Offset));
1123   Inst.addOperand(MCOperand::createImm(Hint));
1124 
1125   return MCDisassembler::Success;
1126 }
1127 
1128 static DecodeStatus DecodeCacheOpR6(MCInst &Inst,
1129                                     unsigned Insn,
1130                                     uint64_t Address,
1131                                     const void *Decoder) {
1132   int Offset = fieldFromInstruction(Insn, 7, 9);
1133   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1134   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1135 
1136   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1137 
1138   Inst.addOperand(MCOperand::createReg(Base));
1139   Inst.addOperand(MCOperand::createImm(Offset));
1140   Inst.addOperand(MCOperand::createImm(Hint));
1141 
1142   return MCDisassembler::Success;
1143 }
1144 
1145 static DecodeStatus DecodeSyncI(MCInst &Inst,
1146                               unsigned Insn,
1147                               uint64_t Address,
1148                               const void *Decoder) {
1149   int Offset = SignExtend32<16>(Insn & 0xffff);
1150   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1151 
1152   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1153 
1154   Inst.addOperand(MCOperand::createReg(Base));
1155   Inst.addOperand(MCOperand::createImm(Offset));
1156 
1157   return MCDisassembler::Success;
1158 }
1159 
1160 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
1161                                     uint64_t Address, const void *Decoder) {
1162   int Offset = SignExtend32<10>(fieldFromInstruction(Insn, 16, 10));
1163   unsigned Reg = fieldFromInstruction(Insn, 6, 5);
1164   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1165 
1166   Reg = getReg(Decoder, Mips::MSA128BRegClassID, Reg);
1167   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1168 
1169   Inst.addOperand(MCOperand::createReg(Reg));
1170   Inst.addOperand(MCOperand::createReg(Base));
1171 
1172   // The immediate field of an LD/ST instruction is scaled which means it must
1173   // be multiplied (when decoding) by the size (in bytes) of the instructions'
1174   // data format.
1175   // .b - 1 byte
1176   // .h - 2 bytes
1177   // .w - 4 bytes
1178   // .d - 8 bytes
1179   switch(Inst.getOpcode())
1180   {
1181   default:
1182     assert (0 && "Unexpected instruction");
1183     return MCDisassembler::Fail;
1184     break;
1185   case Mips::LD_B:
1186   case Mips::ST_B:
1187     Inst.addOperand(MCOperand::createImm(Offset));
1188     break;
1189   case Mips::LD_H:
1190   case Mips::ST_H:
1191     Inst.addOperand(MCOperand::createImm(Offset * 2));
1192     break;
1193   case Mips::LD_W:
1194   case Mips::ST_W:
1195     Inst.addOperand(MCOperand::createImm(Offset * 4));
1196     break;
1197   case Mips::LD_D:
1198   case Mips::ST_D:
1199     Inst.addOperand(MCOperand::createImm(Offset * 8));
1200     break;
1201   }
1202 
1203   return MCDisassembler::Success;
1204 }
1205 
1206 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
1207                                     unsigned Insn,
1208                                     uint64_t Address,
1209                                     const void *Decoder) {
1210   unsigned Offset = Insn & 0xf;
1211   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1212   unsigned Base = fieldFromInstruction(Insn, 4, 3);
1213 
1214   switch (Inst.getOpcode()) {
1215     case Mips::LBU16_MM:
1216     case Mips::LHU16_MM:
1217     case Mips::LW16_MM:
1218       if (DecodeGPRMM16RegisterClass(Inst, Reg, Address, Decoder)
1219             == MCDisassembler::Fail)
1220         return MCDisassembler::Fail;
1221       break;
1222     case Mips::SB16_MM:
1223     case Mips::SH16_MM:
1224     case Mips::SW16_MM:
1225       if (DecodeGPRMM16ZeroRegisterClass(Inst, Reg, Address, Decoder)
1226             == MCDisassembler::Fail)
1227         return MCDisassembler::Fail;
1228       break;
1229   }
1230 
1231   if (DecodeGPRMM16RegisterClass(Inst, Base, Address, Decoder)
1232         == MCDisassembler::Fail)
1233     return MCDisassembler::Fail;
1234 
1235   switch (Inst.getOpcode()) {
1236     case Mips::LBU16_MM:
1237       if (Offset == 0xf)
1238         Inst.addOperand(MCOperand::createImm(-1));
1239       else
1240         Inst.addOperand(MCOperand::createImm(Offset));
1241       break;
1242     case Mips::SB16_MM:
1243       Inst.addOperand(MCOperand::createImm(Offset));
1244       break;
1245     case Mips::LHU16_MM:
1246     case Mips::SH16_MM:
1247       Inst.addOperand(MCOperand::createImm(Offset << 1));
1248       break;
1249     case Mips::LW16_MM:
1250     case Mips::SW16_MM:
1251       Inst.addOperand(MCOperand::createImm(Offset << 2));
1252       break;
1253   }
1254 
1255   return MCDisassembler::Success;
1256 }
1257 
1258 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
1259                                           unsigned Insn,
1260                                           uint64_t Address,
1261                                           const void *Decoder) {
1262   unsigned Offset = Insn & 0x1F;
1263   unsigned Reg = fieldFromInstruction(Insn, 5, 5);
1264 
1265   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1266 
1267   Inst.addOperand(MCOperand::createReg(Reg));
1268   Inst.addOperand(MCOperand::createReg(Mips::SP));
1269   Inst.addOperand(MCOperand::createImm(Offset << 2));
1270 
1271   return MCDisassembler::Success;
1272 }
1273 
1274 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
1275                                           unsigned Insn,
1276                                           uint64_t Address,
1277                                           const void *Decoder) {
1278   unsigned Offset = Insn & 0x7F;
1279   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1280 
1281   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1282 
1283   Inst.addOperand(MCOperand::createReg(Reg));
1284   Inst.addOperand(MCOperand::createReg(Mips::GP));
1285   Inst.addOperand(MCOperand::createImm(Offset << 2));
1286 
1287   return MCDisassembler::Success;
1288 }
1289 
1290 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
1291                                                unsigned Insn,
1292                                                uint64_t Address,
1293                                                const void *Decoder) {
1294   int Offset = SignExtend32<4>(Insn & 0xf);
1295 
1296   if (DecodeRegListOperand16(Inst, Insn, Address, Decoder)
1297       == MCDisassembler::Fail)
1298     return MCDisassembler::Fail;
1299 
1300   Inst.addOperand(MCOperand::createReg(Mips::SP));
1301   Inst.addOperand(MCOperand::createImm(Offset << 2));
1302 
1303   return MCDisassembler::Success;
1304 }
1305 
1306 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
1307                                      unsigned Insn,
1308                                      uint64_t Address,
1309                                      const void *Decoder) {
1310   int Offset = SignExtend32<12>(Insn & 0x0fff);
1311   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1312   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1313 
1314   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1315   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1316 
1317   switch (Inst.getOpcode()) {
1318   case Mips::SWM32_MM:
1319   case Mips::LWM32_MM:
1320     if (DecodeRegListOperand(Inst, Insn, Address, Decoder)
1321         == MCDisassembler::Fail)
1322       return MCDisassembler::Fail;
1323     Inst.addOperand(MCOperand::createReg(Base));
1324     Inst.addOperand(MCOperand::createImm(Offset));
1325     break;
1326   case Mips::SC_MM:
1327     Inst.addOperand(MCOperand::createReg(Reg));
1328     // fallthrough
1329   default:
1330     Inst.addOperand(MCOperand::createReg(Reg));
1331     if (Inst.getOpcode() == Mips::LWP_MM || Inst.getOpcode() == Mips::SWP_MM)
1332       Inst.addOperand(MCOperand::createReg(Reg+1));
1333 
1334     Inst.addOperand(MCOperand::createReg(Base));
1335     Inst.addOperand(MCOperand::createImm(Offset));
1336   }
1337 
1338   return MCDisassembler::Success;
1339 }
1340 
1341 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
1342                                      unsigned Insn,
1343                                      uint64_t Address,
1344                                      const void *Decoder) {
1345   int Offset = SignExtend32<16>(Insn & 0xffff);
1346   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1347   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1348 
1349   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1350   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1351 
1352   Inst.addOperand(MCOperand::createReg(Reg));
1353   Inst.addOperand(MCOperand::createReg(Base));
1354   Inst.addOperand(MCOperand::createImm(Offset));
1355 
1356   return MCDisassembler::Success;
1357 }
1358 
1359 static DecodeStatus DecodeFMem(MCInst &Inst,
1360                                unsigned Insn,
1361                                uint64_t Address,
1362                                const void *Decoder) {
1363   int Offset = SignExtend32<16>(Insn & 0xffff);
1364   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1365   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1366 
1367   Reg = getReg(Decoder, Mips::FGR64RegClassID, Reg);
1368   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1369 
1370   Inst.addOperand(MCOperand::createReg(Reg));
1371   Inst.addOperand(MCOperand::createReg(Base));
1372   Inst.addOperand(MCOperand::createImm(Offset));
1373 
1374   return MCDisassembler::Success;
1375 }
1376 
1377 static DecodeStatus DecodeFMem2(MCInst &Inst,
1378                                unsigned Insn,
1379                                uint64_t Address,
1380                                const void *Decoder) {
1381   int Offset = SignExtend32<16>(Insn & 0xffff);
1382   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1383   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1384 
1385   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1386   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1387 
1388   Inst.addOperand(MCOperand::createReg(Reg));
1389   Inst.addOperand(MCOperand::createReg(Base));
1390   Inst.addOperand(MCOperand::createImm(Offset));
1391 
1392   return MCDisassembler::Success;
1393 }
1394 
1395 static DecodeStatus DecodeFMem3(MCInst &Inst,
1396                                unsigned Insn,
1397                                uint64_t Address,
1398                                const void *Decoder) {
1399   int Offset = SignExtend32<16>(Insn & 0xffff);
1400   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1401   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1402 
1403   Reg = getReg(Decoder, Mips::COP3RegClassID, Reg);
1404   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1405 
1406   Inst.addOperand(MCOperand::createReg(Reg));
1407   Inst.addOperand(MCOperand::createReg(Base));
1408   Inst.addOperand(MCOperand::createImm(Offset));
1409 
1410   return MCDisassembler::Success;
1411 }
1412 
1413 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst,
1414                                     unsigned Insn,
1415                                     uint64_t Address,
1416                                     const void *Decoder) {
1417   int Offset = SignExtend32<11>(Insn & 0x07ff);
1418   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1419   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1420 
1421   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
1422   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1423 
1424   Inst.addOperand(MCOperand::createReg(Reg));
1425   Inst.addOperand(MCOperand::createReg(Base));
1426   Inst.addOperand(MCOperand::createImm(Offset));
1427 
1428   return MCDisassembler::Success;
1429 }
1430 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
1431                                        unsigned Insn,
1432                                        uint64_t Address,
1433                                        const void *Decoder) {
1434   int64_t Offset = SignExtend64<9>((Insn >> 7) & 0x1ff);
1435   unsigned Rt = fieldFromInstruction(Insn, 16, 5);
1436   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1437 
1438   Rt = getReg(Decoder, Mips::GPR32RegClassID, Rt);
1439   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1440 
1441   if(Inst.getOpcode() == Mips::SC_R6 || Inst.getOpcode() == Mips::SCD_R6){
1442     Inst.addOperand(MCOperand::createReg(Rt));
1443   }
1444 
1445   Inst.addOperand(MCOperand::createReg(Rt));
1446   Inst.addOperand(MCOperand::createReg(Base));
1447   Inst.addOperand(MCOperand::createImm(Offset));
1448 
1449   return MCDisassembler::Success;
1450 }
1451 
1452 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
1453                                               unsigned RegNo,
1454                                               uint64_t Address,
1455                                               const void *Decoder) {
1456   // Currently only hardware register 29 is supported.
1457   if (RegNo != 29)
1458     return  MCDisassembler::Fail;
1459   Inst.addOperand(MCOperand::createReg(Mips::HWR29));
1460   return MCDisassembler::Success;
1461 }
1462 
1463 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
1464                                               unsigned RegNo,
1465                                               uint64_t Address,
1466                                               const void *Decoder) {
1467   if (RegNo > 30 || RegNo %2)
1468     return MCDisassembler::Fail;
1469 
1470   ;
1471   unsigned Reg = getReg(Decoder, Mips::AFGR64RegClassID, RegNo /2);
1472   Inst.addOperand(MCOperand::createReg(Reg));
1473   return MCDisassembler::Success;
1474 }
1475 
1476 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
1477                                                 unsigned RegNo,
1478                                                 uint64_t Address,
1479                                                 const void *Decoder) {
1480   if (RegNo >= 4)
1481     return MCDisassembler::Fail;
1482 
1483   unsigned Reg = getReg(Decoder, Mips::ACC64DSPRegClassID, RegNo);
1484   Inst.addOperand(MCOperand::createReg(Reg));
1485   return MCDisassembler::Success;
1486 }
1487 
1488 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
1489                                                unsigned RegNo,
1490                                                uint64_t Address,
1491                                                const void *Decoder) {
1492   if (RegNo >= 4)
1493     return MCDisassembler::Fail;
1494 
1495   unsigned Reg = getReg(Decoder, Mips::HI32DSPRegClassID, RegNo);
1496   Inst.addOperand(MCOperand::createReg(Reg));
1497   return MCDisassembler::Success;
1498 }
1499 
1500 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
1501                                                unsigned RegNo,
1502                                                uint64_t Address,
1503                                                const void *Decoder) {
1504   if (RegNo >= 4)
1505     return MCDisassembler::Fail;
1506 
1507   unsigned Reg = getReg(Decoder, Mips::LO32DSPRegClassID, RegNo);
1508   Inst.addOperand(MCOperand::createReg(Reg));
1509   return MCDisassembler::Success;
1510 }
1511 
1512 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
1513                                                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::MSA128BRegClassID, RegNo);
1520   Inst.addOperand(MCOperand::createReg(Reg));
1521   return MCDisassembler::Success;
1522 }
1523 
1524 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
1525                                                unsigned RegNo,
1526                                                uint64_t Address,
1527                                                const void *Decoder) {
1528   if (RegNo > 31)
1529     return MCDisassembler::Fail;
1530 
1531   unsigned Reg = getReg(Decoder, Mips::MSA128HRegClassID, RegNo);
1532   Inst.addOperand(MCOperand::createReg(Reg));
1533   return MCDisassembler::Success;
1534 }
1535 
1536 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
1537                                                unsigned RegNo,
1538                                                uint64_t Address,
1539                                                const void *Decoder) {
1540   if (RegNo > 31)
1541     return MCDisassembler::Fail;
1542 
1543   unsigned Reg = getReg(Decoder, Mips::MSA128WRegClassID, RegNo);
1544   Inst.addOperand(MCOperand::createReg(Reg));
1545   return MCDisassembler::Success;
1546 }
1547 
1548 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
1549                                                unsigned RegNo,
1550                                                uint64_t Address,
1551                                                const void *Decoder) {
1552   if (RegNo > 31)
1553     return MCDisassembler::Fail;
1554 
1555   unsigned Reg = getReg(Decoder, Mips::MSA128DRegClassID, RegNo);
1556   Inst.addOperand(MCOperand::createReg(Reg));
1557   return MCDisassembler::Success;
1558 }
1559 
1560 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
1561                                                unsigned RegNo,
1562                                                uint64_t Address,
1563                                                const void *Decoder) {
1564   if (RegNo > 7)
1565     return MCDisassembler::Fail;
1566 
1567   unsigned Reg = getReg(Decoder, Mips::MSACtrlRegClassID, RegNo);
1568   Inst.addOperand(MCOperand::createReg(Reg));
1569   return MCDisassembler::Success;
1570 }
1571 
1572 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
1573                                             unsigned RegNo,
1574                                             uint64_t Address,
1575                                             const void *Decoder) {
1576   if (RegNo > 31)
1577     return MCDisassembler::Fail;
1578 
1579   unsigned Reg = getReg(Decoder, Mips::COP0RegClassID, RegNo);
1580   Inst.addOperand(MCOperand::createReg(Reg));
1581   return MCDisassembler::Success;
1582 }
1583 
1584 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
1585                                             unsigned RegNo,
1586                                             uint64_t Address,
1587                                             const void *Decoder) {
1588   if (RegNo > 31)
1589     return MCDisassembler::Fail;
1590 
1591   unsigned Reg = getReg(Decoder, Mips::COP2RegClassID, RegNo);
1592   Inst.addOperand(MCOperand::createReg(Reg));
1593   return MCDisassembler::Success;
1594 }
1595 
1596 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
1597                                        unsigned Offset,
1598                                        uint64_t Address,
1599                                        const void *Decoder) {
1600   int32_t BranchOffset = (SignExtend32<16>(Offset) * 4) + 4;
1601   Inst.addOperand(MCOperand::createImm(BranchOffset));
1602   return MCDisassembler::Success;
1603 }
1604 
1605 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
1606                                      unsigned Insn,
1607                                      uint64_t Address,
1608                                      const void *Decoder) {
1609 
1610   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
1611   Inst.addOperand(MCOperand::createImm(JumpOffset));
1612   return MCDisassembler::Success;
1613 }
1614 
1615 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
1616                                          unsigned Offset,
1617                                          uint64_t Address,
1618                                          const void *Decoder) {
1619   int32_t BranchOffset = SignExtend32<21>(Offset) * 4;
1620 
1621   Inst.addOperand(MCOperand::createImm(BranchOffset));
1622   return MCDisassembler::Success;
1623 }
1624 
1625 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
1626                                          unsigned Offset,
1627                                          uint64_t Address,
1628                                          const void *Decoder) {
1629   int32_t BranchOffset = SignExtend32<26>(Offset) * 4;
1630 
1631   Inst.addOperand(MCOperand::createImm(BranchOffset));
1632   return MCDisassembler::Success;
1633 }
1634 
1635 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
1636                                           unsigned Offset,
1637                                           uint64_t Address,
1638                                           const void *Decoder) {
1639   int32_t BranchOffset = SignExtend32<7>(Offset) << 1;
1640   Inst.addOperand(MCOperand::createImm(BranchOffset));
1641   return MCDisassembler::Success;
1642 }
1643 
1644 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
1645                                            unsigned Offset,
1646                                            uint64_t Address,
1647                                            const void *Decoder) {
1648   int32_t BranchOffset = SignExtend32<10>(Offset) << 1;
1649   Inst.addOperand(MCOperand::createImm(BranchOffset));
1650   return MCDisassembler::Success;
1651 }
1652 
1653 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
1654                                          unsigned Offset,
1655                                          uint64_t Address,
1656                                          const void *Decoder) {
1657   int32_t BranchOffset = SignExtend32<16>(Offset) * 2;
1658   Inst.addOperand(MCOperand::createImm(BranchOffset));
1659   return MCDisassembler::Success;
1660 }
1661 
1662 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
1663                                        unsigned Insn,
1664                                        uint64_t Address,
1665                                        const void *Decoder) {
1666   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 1;
1667   Inst.addOperand(MCOperand::createImm(JumpOffset));
1668   return MCDisassembler::Success;
1669 }
1670 
1671 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
1672                                        unsigned Value,
1673                                        uint64_t Address,
1674                                        const void *Decoder) {
1675   if (Value == 0)
1676     Inst.addOperand(MCOperand::createImm(1));
1677   else if (Value == 0x7)
1678     Inst.addOperand(MCOperand::createImm(-1));
1679   else
1680     Inst.addOperand(MCOperand::createImm(Value << 2));
1681   return MCDisassembler::Success;
1682 }
1683 
1684 static DecodeStatus DecodeUImm6Lsl2(MCInst &Inst,
1685                                     unsigned Value,
1686                                     uint64_t Address,
1687                                     const void *Decoder) {
1688   Inst.addOperand(MCOperand::createImm(Value << 2));
1689   return MCDisassembler::Success;
1690 }
1691 
1692 static DecodeStatus DecodeLiSimm7(MCInst &Inst,
1693                                   unsigned Value,
1694                                   uint64_t Address,
1695                                   const void *Decoder) {
1696   if (Value == 0x7F)
1697     Inst.addOperand(MCOperand::createImm(-1));
1698   else
1699     Inst.addOperand(MCOperand::createImm(Value));
1700   return MCDisassembler::Success;
1701 }
1702 
1703 static DecodeStatus DecodeSimm4(MCInst &Inst,
1704                                 unsigned Value,
1705                                 uint64_t Address,
1706                                 const void *Decoder) {
1707   Inst.addOperand(MCOperand::createImm(SignExtend32<4>(Value)));
1708   return MCDisassembler::Success;
1709 }
1710 
1711 static DecodeStatus DecodeSimm16(MCInst &Inst,
1712                                  unsigned Insn,
1713                                  uint64_t Address,
1714                                  const void *Decoder) {
1715   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Insn)));
1716   return MCDisassembler::Success;
1717 }
1718 
1719 static DecodeStatus DecodeLSAImm(MCInst &Inst,
1720                                  unsigned Insn,
1721                                  uint64_t Address,
1722                                  const void *Decoder) {
1723   // We add one to the immediate field as it was encoded as 'imm - 1'.
1724   Inst.addOperand(MCOperand::createImm(Insn + 1));
1725   return MCDisassembler::Success;
1726 }
1727 
1728 static DecodeStatus DecodeInsSize(MCInst &Inst,
1729                                   unsigned Insn,
1730                                   uint64_t Address,
1731                                   const void *Decoder) {
1732   // First we need to grab the pos(lsb) from MCInst.
1733   int Pos = Inst.getOperand(2).getImm();
1734   int Size = (int) Insn - Pos + 1;
1735   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Size)));
1736   return MCDisassembler::Success;
1737 }
1738 
1739 static DecodeStatus DecodeExtSize(MCInst &Inst,
1740                                   unsigned Insn,
1741                                   uint64_t Address,
1742                                   const void *Decoder) {
1743   int Size = (int) Insn  + 1;
1744   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Size)));
1745   return MCDisassembler::Success;
1746 }
1747 
1748 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
1749                                      uint64_t Address, const void *Decoder) {
1750   Inst.addOperand(MCOperand::createImm(SignExtend32<19>(Insn) * 4));
1751   return MCDisassembler::Success;
1752 }
1753 
1754 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
1755                                      uint64_t Address, const void *Decoder) {
1756   Inst.addOperand(MCOperand::createImm(SignExtend32<18>(Insn) * 8));
1757   return MCDisassembler::Success;
1758 }
1759 
1760 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
1761                                   uint64_t Address, const void *Decoder) {
1762   int32_t DecodedValue;
1763   switch (Insn) {
1764   case 0: DecodedValue = 256; break;
1765   case 1: DecodedValue = 257; break;
1766   case 510: DecodedValue = -258; break;
1767   case 511: DecodedValue = -257; break;
1768   default: DecodedValue = SignExtend32<9>(Insn); break;
1769   }
1770   Inst.addOperand(MCOperand::createImm(DecodedValue * 4));
1771   return MCDisassembler::Success;
1772 }
1773 
1774 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
1775                                     uint64_t Address, const void *Decoder) {
1776   // Insn must be >= 0, since it is unsigned that condition is always true.
1777   assert(Insn < 16);
1778   int32_t DecodedValues[] = {128, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64,
1779                              255, 32768, 65535};
1780   Inst.addOperand(MCOperand::createImm(DecodedValues[Insn]));
1781   return MCDisassembler::Success;
1782 }
1783 
1784 static DecodeStatus DecodeUImm5lsl2(MCInst &Inst, unsigned Insn,
1785                                     uint64_t Address, const void *Decoder) {
1786   Inst.addOperand(MCOperand::createImm(Insn << 2));
1787   return MCDisassembler::Success;
1788 }
1789 
1790 static DecodeStatus DecodeRegListOperand(MCInst &Inst,
1791                                          unsigned Insn,
1792                                          uint64_t Address,
1793                                          const void *Decoder) {
1794   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5,
1795                      Mips::S6, Mips::FP};
1796   unsigned RegNum;
1797 
1798   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
1799   // Empty register lists are not allowed.
1800   if (RegLst == 0)
1801     return MCDisassembler::Fail;
1802 
1803   RegNum = RegLst & 0xf;
1804   for (unsigned i = 0; i < RegNum; i++)
1805     Inst.addOperand(MCOperand::createReg(Regs[i]));
1806 
1807   if (RegLst & 0x10)
1808     Inst.addOperand(MCOperand::createReg(Mips::RA));
1809 
1810   return MCDisassembler::Success;
1811 }
1812 
1813 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
1814                                            uint64_t Address,
1815                                            const void *Decoder) {
1816   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
1817   unsigned RegLst = fieldFromInstruction(Insn, 4, 2);
1818   unsigned RegNum = RegLst & 0x3;
1819 
1820   for (unsigned i = 0; i <= RegNum; i++)
1821     Inst.addOperand(MCOperand::createReg(Regs[i]));
1822 
1823   Inst.addOperand(MCOperand::createReg(Mips::RA));
1824 
1825   return MCDisassembler::Success;
1826 }
1827 
1828 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
1829                                        uint64_t Address, const void *Decoder) {
1830 
1831   unsigned RegPair = fieldFromInstruction(Insn, 7, 3);
1832 
1833   switch (RegPair) {
1834   default:
1835     return MCDisassembler::Fail;
1836   case 0:
1837     Inst.addOperand(MCOperand::createReg(Mips::A1));
1838     Inst.addOperand(MCOperand::createReg(Mips::A2));
1839     break;
1840   case 1:
1841     Inst.addOperand(MCOperand::createReg(Mips::A1));
1842     Inst.addOperand(MCOperand::createReg(Mips::A3));
1843     break;
1844   case 2:
1845     Inst.addOperand(MCOperand::createReg(Mips::A2));
1846     Inst.addOperand(MCOperand::createReg(Mips::A3));
1847     break;
1848   case 3:
1849     Inst.addOperand(MCOperand::createReg(Mips::A0));
1850     Inst.addOperand(MCOperand::createReg(Mips::S5));
1851     break;
1852   case 4:
1853     Inst.addOperand(MCOperand::createReg(Mips::A0));
1854     Inst.addOperand(MCOperand::createReg(Mips::S6));
1855     break;
1856   case 5:
1857     Inst.addOperand(MCOperand::createReg(Mips::A0));
1858     Inst.addOperand(MCOperand::createReg(Mips::A1));
1859     break;
1860   case 6:
1861     Inst.addOperand(MCOperand::createReg(Mips::A0));
1862     Inst.addOperand(MCOperand::createReg(Mips::A2));
1863     break;
1864   case 7:
1865     Inst.addOperand(MCOperand::createReg(Mips::A0));
1866     Inst.addOperand(MCOperand::createReg(Mips::A3));
1867     break;
1868   }
1869 
1870   return MCDisassembler::Success;
1871 }
1872 
1873 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
1874                                      uint64_t Address, const void *Decoder) {
1875   Inst.addOperand(MCOperand::createImm(SignExtend32<25>(Insn << 2)));
1876   return MCDisassembler::Success;
1877 }
1878