1 //===- MipsDisassembler.cpp - Disassembler for Mips -----------------------===//
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 "MCTargetDesc/MipsMCTargetDesc.h"
15 #include "Mips.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/Support/Compiler.h"
24 #include "llvm/Support/Debug.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/MathExtras.h"
27 #include "llvm/Support/TargetRegistry.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 hasCOP3() const {
67     // Only present in MIPS-I and MIPS-II
68     return !hasMips32() && !hasMips3();
69   }
70 
71   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
72                               ArrayRef<uint8_t> Bytes, uint64_t Address,
73                               raw_ostream &VStream,
74                               raw_ostream &CStream) const override;
75 };
76 
77 } // end anonymous namespace
78 
79 // Forward declare these because the autogenerated code will reference them.
80 // Definitions are further down.
81 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
82                                              unsigned RegNo,
83                                              uint64_t Address,
84                                              const void *Decoder);
85 
86 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
87                                                  unsigned RegNo,
88                                                  uint64_t Address,
89                                                  const void *Decoder);
90 
91 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
92                                                unsigned RegNo,
93                                                uint64_t Address,
94                                                const void *Decoder);
95 
96 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
97                                                    unsigned RegNo,
98                                                    uint64_t Address,
99                                                    const void *Decoder);
100 
101 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
102                                                     unsigned RegNo,
103                                                     uint64_t Address,
104                                                     const void *Decoder);
105 
106 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
107                                              unsigned RegNo,
108                                              uint64_t Address,
109                                              const void *Decoder);
110 
111 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
112                                            unsigned Insn,
113                                            uint64_t Address,
114                                            const void *Decoder);
115 
116 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
117                                             unsigned RegNo,
118                                             uint64_t Address,
119                                             const void *Decoder);
120 
121 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
122                                              unsigned RegNo,
123                                              uint64_t Address,
124                                              const void *Decoder);
125 
126 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
127                                              unsigned RegNo,
128                                              uint64_t Address,
129                                              const void *Decoder);
130 
131 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
132                                            unsigned RegNo,
133                                            uint64_t Address,
134                                            const void *Decoder);
135 
136 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
137                                            unsigned RegNo,
138                                            uint64_t Address,
139                                            const void *Decoder);
140 
141 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
142                                              uint64_t Address,
143                                              const void *Decoder);
144 
145 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
146                                               unsigned Insn,
147                                               uint64_t Address,
148                                               const void *Decoder);
149 
150 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
151                                               unsigned RegNo,
152                                               uint64_t Address,
153                                               const void *Decoder);
154 
155 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
156                                                 unsigned RegNo,
157                                                 uint64_t Address,
158                                                 const void *Decoder);
159 
160 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
161                                                unsigned RegNo,
162                                                uint64_t Address,
163                                                const void *Decoder);
164 
165 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
166                                                unsigned RegNo,
167                                                uint64_t Address,
168                                                const void *Decoder);
169 
170 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
171                                                unsigned RegNo,
172                                                uint64_t Address,
173                                                const void *Decoder);
174 
175 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
176                                                unsigned RegNo,
177                                                uint64_t Address,
178                                                const void *Decoder);
179 
180 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
181                                                unsigned RegNo,
182                                                uint64_t Address,
183                                                const void *Decoder);
184 
185 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
186                                                unsigned RegNo,
187                                                uint64_t Address,
188                                                const void *Decoder);
189 
190 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
191                                                unsigned RegNo,
192                                                uint64_t Address,
193                                                const void *Decoder);
194 
195 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
196                                             unsigned RegNo,
197                                             uint64_t Address,
198                                             const void *Decoder);
199 
200 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
201                                             unsigned RegNo,
202                                             uint64_t Address,
203                                             const void *Decoder);
204 
205 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
206                                        unsigned Offset,
207                                        uint64_t Address,
208                                        const void *Decoder);
209 
210 static DecodeStatus DecodeBranchTarget1SImm16(MCInst &Inst,
211                                               unsigned Offset,
212                                               uint64_t Address,
213                                               const void *Decoder);
214 
215 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
216                                      unsigned Insn,
217                                      uint64_t Address,
218                                      const void *Decoder);
219 
220 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
221                                          unsigned Offset,
222                                          uint64_t Address,
223                                          const void *Decoder);
224 
225 static DecodeStatus DecodeBranchTarget21MM(MCInst &Inst,
226                                            unsigned Offset,
227                                            uint64_t Address,
228                                            const void *Decoder);
229 
230 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
231                                          unsigned Offset,
232                                          uint64_t Address,
233                                          const void *Decoder);
234 
235 // DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
236 // shifted left by 1 bit.
237 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
238                                           unsigned Offset,
239                                           uint64_t Address,
240                                           const void *Decoder);
241 
242 // DecodeBranchTarget10MM - Decode microMIPS branch offset, which is
243 // shifted left by 1 bit.
244 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
245                                            unsigned Offset,
246                                            uint64_t Address,
247                                            const void *Decoder);
248 
249 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
250 // shifted left by 1 bit.
251 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
252                                          unsigned Offset,
253                                          uint64_t Address,
254                                          const void *Decoder);
255 
256 // DecodeBranchTarget26MM - Decode microMIPS branch offset, which is
257 // shifted left by 1 bit.
258 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
259                                            unsigned Offset,
260                                            uint64_t Address,
261                                            const void *Decoder);
262 
263 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
264 // shifted left by 1 bit.
265 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
266                                        unsigned Insn,
267                                        uint64_t Address,
268                                        const void *Decoder);
269 
270 static DecodeStatus DecodeMem(MCInst &Inst,
271                               unsigned Insn,
272                               uint64_t Address,
273                               const void *Decoder);
274 
275 static DecodeStatus DecodeMemEVA(MCInst &Inst,
276                                  unsigned Insn,
277                                  uint64_t Address,
278                                  const void *Decoder);
279 
280 static DecodeStatus DecodeLoadByte9(MCInst &Inst,
281                                     unsigned Insn,
282                                     uint64_t Address,
283                                     const void *Decoder);
284 
285 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
286                                      unsigned Insn,
287                                      uint64_t Address,
288                                      const void *Decoder);
289 
290 static DecodeStatus DecodeCacheOp(MCInst &Inst, unsigned Insn, uint64_t Address,
291                                   const void *Decoder);
292 
293 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
294                                              unsigned Insn,
295                                              uint64_t Address,
296                                              const void *Decoder);
297 
298 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
299                                     unsigned Insn,
300                                     uint64_t Address,
301                                     const void *Decoder);
302 
303 static DecodeStatus DecodeStoreEvaOpMM(MCInst &Inst,
304                                        unsigned Insn,
305                                        uint64_t Address,
306                                        const void *Decoder);
307 
308 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
309                                     unsigned Insn,
310                                     uint64_t Address,
311                                     const void *Decoder);
312 
313 static DecodeStatus DecodeSyncI(MCInst &Inst,
314                                 unsigned Insn,
315                                 uint64_t Address,
316                                 const void *Decoder);
317 
318 static DecodeStatus DecodeSynciR6(MCInst &Inst,
319                                   unsigned Insn,
320                                   uint64_t Address,
321                                   const void *Decoder);
322 
323 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
324                                     uint64_t Address, const void *Decoder);
325 
326 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
327                                     unsigned Insn,
328                                     uint64_t Address,
329                                     const void *Decoder);
330 
331 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
332                                           unsigned Insn,
333                                           uint64_t Address,
334                                           const void *Decoder);
335 
336 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
337                                           unsigned Insn,
338                                           uint64_t Address,
339                                           const void *Decoder);
340 
341 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
342                                                unsigned Insn,
343                                                uint64_t Address,
344                                                const void *Decoder);
345 
346 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
347                                     unsigned Insn,
348                                     uint64_t Address,
349                                     const void *Decoder);
350 
351 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
352                                      unsigned Insn,
353                                      uint64_t Address,
354                                      const void *Decoder);
355 
356 static DecodeStatus DecodeMemMMImm16(MCInst &Inst,
357                                      unsigned Insn,
358                                      uint64_t Address,
359                                      const void *Decoder);
360 
361 static DecodeStatus DecodeFMem(MCInst &Inst, unsigned Insn,
362                                uint64_t Address,
363                                const void *Decoder);
364 
365 static DecodeStatus DecodeFMemMMR2(MCInst &Inst, unsigned Insn,
366                                    uint64_t Address,
367                                    const void *Decoder);
368 
369 static DecodeStatus DecodeFMem2(MCInst &Inst, unsigned Insn, uint64_t Address,
370                                 const void *Decoder);
371 
372 static DecodeStatus DecodeFMem3(MCInst &Inst, unsigned Insn, uint64_t Address,
373                                 const void *Decoder);
374 
375 static DecodeStatus DecodeFMemCop2R6(MCInst &Inst, unsigned Insn,
376                                      uint64_t Address, const void *Decoder);
377 
378 static DecodeStatus DecodeFMemCop2MMR6(MCInst &Inst, unsigned Insn,
379                                        uint64_t Address,
380                                        const void *Decoder);
381 
382 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
383                                        unsigned Insn,
384                                        uint64_t Address,
385                                        const void *Decoder);
386 
387 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
388                                        unsigned Value,
389                                        uint64_t Address,
390                                        const void *Decoder);
391 
392 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
393                                   unsigned Value,
394                                   uint64_t Address,
395                                   const void *Decoder);
396 
397 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
398                                               unsigned Value,
399                                               uint64_t Address,
400                                               const void *Decoder);
401 
402 template <unsigned Bits, int Offset, int Scale>
403 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
404                                                  uint64_t Address,
405                                                  const void *Decoder);
406 
407 template <unsigned Bits, int Offset>
408 static DecodeStatus DecodeUImmWithOffset(MCInst &Inst, unsigned Value,
409                                          uint64_t Address,
410                                          const void *Decoder) {
411   return DecodeUImmWithOffsetAndScale<Bits, Offset, 1>(Inst, Value, Address,
412                                                        Decoder);
413 }
414 
415 template <unsigned Bits, int Offset = 0, int ScaleBy = 1>
416 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
417                                                  uint64_t Address,
418                                                  const void *Decoder);
419 
420 static DecodeStatus DecodeInsSize(MCInst &Inst,
421                                   unsigned Insn,
422                                   uint64_t Address,
423                                   const void *Decoder);
424 
425 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
426                                      uint64_t Address, const void *Decoder);
427 
428 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
429                                      uint64_t Address, const void *Decoder);
430 
431 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
432                                   uint64_t Address, const void *Decoder);
433 
434 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
435                                     uint64_t Address, const void *Decoder);
436 
437 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
438                                      uint64_t Address, const void *Decoder);
439 
440 /// INSVE_[BHWD] have an implicit operand that the generated decoder doesn't
441 /// handle.
442 template <typename InsnType>
443 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
444                                    const void *Decoder);
445 
446 template <typename InsnType>
447 static DecodeStatus DecodeDAHIDATIMMR6(MCInst &MI, InsnType insn, uint64_t Address,
448                                    const void *Decoder);
449 
450 template <typename InsnType>
451 static DecodeStatus DecodeDAHIDATI(MCInst &MI, InsnType insn, uint64_t Address,
452                                    const void *Decoder);
453 
454 template <typename InsnType>
455 static DecodeStatus DecodeDAHIDATIMMR6(MCInst &MI, InsnType insn, uint64_t Address,
456                                    const void *Decoder);
457 
458 template <typename InsnType>
459 static DecodeStatus DecodeDAHIDATI(MCInst &MI, InsnType insn, uint64_t Address,
460                                    const void *Decoder);
461 
462 template <typename InsnType>
463 static DecodeStatus
464 DecodeAddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
465                       const void *Decoder);
466 
467 template <typename InsnType>
468 static DecodeStatus
469 DecodePOP35GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
470                            const void *Decoder);
471 
472 template <typename InsnType>
473 static DecodeStatus
474 DecodeDaddiGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
475                        const void *Decoder);
476 
477 template <typename InsnType>
478 static DecodeStatus
479 DecodePOP37GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
480                            const void *Decoder);
481 
482 template <typename InsnType>
483 static DecodeStatus
484 DecodePOP65GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
485                            const void *Decoder);
486 
487 template <typename InsnType>
488 static DecodeStatus
489 DecodePOP75GroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
490                            const void *Decoder);
491 
492 template <typename InsnType>
493 static DecodeStatus
494 DecodeBlezlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
495                        const void *Decoder);
496 
497 template <typename InsnType>
498 static DecodeStatus
499 DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
500                        const void *Decoder);
501 
502 template <typename InsnType>
503 static DecodeStatus
504 DecodeBgtzGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
505                       const void *Decoder);
506 
507 template <typename InsnType>
508 static DecodeStatus
509 DecodeBlezGroupBranch(MCInst &MI, InsnType insn, uint64_t Address,
510                        const void *Decoder);
511 
512 template <typename InsnType>
513 static DecodeStatus
514 DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
515                           const void *Decoder);
516 
517 template <typename InsnType>
518 static DecodeStatus
519 DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn, uint64_t Address,
520                           const void *Decoder);
521 
522 template <typename InsnType>
523 static DecodeStatus DecodeDINS(MCInst &MI, InsnType Insn, uint64_t Address,
524                                const void *Decoder);
525 
526 template <typename InsnType>
527 static DecodeStatus DecodeDEXT(MCInst &MI, InsnType Insn, uint64_t Address,
528                                const void *Decoder);
529 
530 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
531                                          uint64_t Address,
532                                          const void *Decoder);
533 
534 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
535                                            uint64_t Address,
536                                            const void *Decoder);
537 
538 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
539                                        uint64_t Address,
540                                        const void *Decoder);
541 
542 namespace llvm {
543 
544 Target &getTheMipselTarget();
545 Target &getTheMipsTarget();
546 Target &getTheMips64Target();
547 Target &getTheMips64elTarget();
548 
549 } // end namespace llvm
550 
551 static MCDisassembler *createMipsDisassembler(
552                        const Target &T,
553                        const MCSubtargetInfo &STI,
554                        MCContext &Ctx) {
555   return new MipsDisassembler(STI, Ctx, true);
556 }
557 
558 static MCDisassembler *createMipselDisassembler(
559                        const Target &T,
560                        const MCSubtargetInfo &STI,
561                        MCContext &Ctx) {
562   return new MipsDisassembler(STI, Ctx, false);
563 }
564 
565 extern "C" void LLVMInitializeMipsDisassembler() {
566   // Register the disassembler.
567   TargetRegistry::RegisterMCDisassembler(getTheMipsTarget(),
568                                          createMipsDisassembler);
569   TargetRegistry::RegisterMCDisassembler(getTheMipselTarget(),
570                                          createMipselDisassembler);
571   TargetRegistry::RegisterMCDisassembler(getTheMips64Target(),
572                                          createMipsDisassembler);
573   TargetRegistry::RegisterMCDisassembler(getTheMips64elTarget(),
574                                          createMipselDisassembler);
575 }
576 
577 #include "MipsGenDisassemblerTables.inc"
578 
579 static unsigned getReg(const void *D, unsigned RC, unsigned RegNo) {
580   const MipsDisassembler *Dis = static_cast<const MipsDisassembler*>(D);
581   const MCRegisterInfo *RegInfo = Dis->getContext().getRegisterInfo();
582   return *(RegInfo->getRegClass(RC).begin() + RegNo);
583 }
584 
585 template <typename InsnType>
586 static DecodeStatus DecodeINSVE_DF(MCInst &MI, InsnType insn, uint64_t Address,
587                                    const void *Decoder) {
588   using DecodeFN = DecodeStatus (*)(MCInst &, unsigned, uint64_t, const void *);
589 
590   // The size of the n field depends on the element size
591   // The register class also depends on this.
592   InsnType tmp = fieldFromInstruction(insn, 17, 5);
593   unsigned NSize = 0;
594   DecodeFN RegDecoder = nullptr;
595   if ((tmp & 0x18) == 0x00) { // INSVE_B
596     NSize = 4;
597     RegDecoder = DecodeMSA128BRegisterClass;
598   } else if ((tmp & 0x1c) == 0x10) { // INSVE_H
599     NSize = 3;
600     RegDecoder = DecodeMSA128HRegisterClass;
601   } else if ((tmp & 0x1e) == 0x18) { // INSVE_W
602     NSize = 2;
603     RegDecoder = DecodeMSA128WRegisterClass;
604   } else if ((tmp & 0x1f) == 0x1c) { // INSVE_D
605     NSize = 1;
606     RegDecoder = DecodeMSA128DRegisterClass;
607   } else
608     llvm_unreachable("Invalid encoding");
609 
610   assert(NSize != 0 && RegDecoder != nullptr);
611 
612   // $wd
613   tmp = fieldFromInstruction(insn, 6, 5);
614   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
615     return MCDisassembler::Fail;
616   // $wd_in
617   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
618     return MCDisassembler::Fail;
619   // $n
620   tmp = fieldFromInstruction(insn, 16, NSize);
621   MI.addOperand(MCOperand::createImm(tmp));
622   // $ws
623   tmp = fieldFromInstruction(insn, 11, 5);
624   if (RegDecoder(MI, tmp, Address, Decoder) == MCDisassembler::Fail)
625     return MCDisassembler::Fail;
626   // $n2
627   MI.addOperand(MCOperand::createImm(0));
628 
629   return MCDisassembler::Success;
630 }
631 
632 template <typename InsnType>
633 static DecodeStatus DecodeDAHIDATIMMR6(MCInst &MI, InsnType insn, uint64_t Address,
634                                const void *Decoder) {
635   InsnType Rs = fieldFromInstruction(insn, 16, 5);
636   InsnType Imm = fieldFromInstruction(insn, 0, 16);
637   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
638                                        Rs)));
639   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
640                                        Rs)));
641   MI.addOperand(MCOperand::createImm(Imm));
642 
643   return MCDisassembler::Success;
644 }
645 
646 template <typename InsnType>
647 static DecodeStatus DecodeDAHIDATI(MCInst &MI, InsnType insn, uint64_t Address,
648                                const void *Decoder) {
649   InsnType Rs = fieldFromInstruction(insn, 21, 5);
650   InsnType Imm = fieldFromInstruction(insn, 0, 16);
651   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
652                                        Rs)));
653   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID,
654                                        Rs)));
655   MI.addOperand(MCOperand::createImm(Imm));
656 
657   return MCDisassembler::Success;
658 }
659 
660 template <typename InsnType>
661 static DecodeStatus DecodeAddiGroupBranch(MCInst &MI, InsnType insn,
662                                           uint64_t Address,
663                                           const void *Decoder) {
664   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
665   // (otherwise we would have matched the ADDI instruction from the earlier
666   // ISA's instead).
667   //
668   // We have:
669   //    0b001000 sssss ttttt iiiiiiiiiiiiiiii
670   //      BOVC if rs >= rt
671   //      BEQZALC if rs == 0 && rt != 0
672   //      BEQC if rs < rt && rs != 0
673 
674   InsnType Rs = fieldFromInstruction(insn, 21, 5);
675   InsnType Rt = fieldFromInstruction(insn, 16, 5);
676   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
677   bool HasRs = false;
678 
679   if (Rs >= Rt) {
680     MI.setOpcode(Mips::BOVC);
681     HasRs = true;
682   } else if (Rs != 0 && Rs < Rt) {
683     MI.setOpcode(Mips::BEQC);
684     HasRs = true;
685   } else
686     MI.setOpcode(Mips::BEQZALC);
687 
688   if (HasRs)
689     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
690                                        Rs)));
691 
692   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
693                                      Rt)));
694   MI.addOperand(MCOperand::createImm(Imm));
695 
696   return MCDisassembler::Success;
697 }
698 
699 template <typename InsnType>
700 static DecodeStatus DecodePOP35GroupBranchMMR6(MCInst &MI, InsnType insn,
701                                                uint64_t Address,
702                                                const void *Decoder) {
703   InsnType Rt = fieldFromInstruction(insn, 21, 5);
704   InsnType Rs = fieldFromInstruction(insn, 16, 5);
705   int64_t Imm = 0;
706 
707   if (Rs >= Rt) {
708     MI.setOpcode(Mips::BOVC_MMR6);
709     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
710                                        Rt)));
711     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
712                                        Rs)));
713     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
714   } else if (Rs != 0 && Rs < Rt) {
715     MI.setOpcode(Mips::BEQC_MMR6);
716     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
717                                        Rs)));
718     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
719                                        Rt)));
720     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
721   } else {
722     MI.setOpcode(Mips::BEQZALC_MMR6);
723     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
724                                        Rt)));
725     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
726   }
727 
728   MI.addOperand(MCOperand::createImm(Imm));
729 
730   return MCDisassembler::Success;
731 }
732 
733 template <typename InsnType>
734 static DecodeStatus DecodeDaddiGroupBranch(MCInst &MI, InsnType insn,
735                                            uint64_t Address,
736                                            const void *Decoder) {
737   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
738   // (otherwise we would have matched the ADDI instruction from the earlier
739   // ISA's instead).
740   //
741   // We have:
742   //    0b011000 sssss ttttt iiiiiiiiiiiiiiii
743   //      BNVC if rs >= rt
744   //      BNEZALC if rs == 0 && rt != 0
745   //      BNEC if rs < rt && rs != 0
746 
747   InsnType Rs = fieldFromInstruction(insn, 21, 5);
748   InsnType Rt = fieldFromInstruction(insn, 16, 5);
749   int64_t  Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
750   bool HasRs = false;
751 
752   if (Rs >= Rt) {
753     MI.setOpcode(Mips::BNVC);
754     HasRs = true;
755   } else if (Rs != 0 && Rs < Rt) {
756     MI.setOpcode(Mips::BNEC);
757     HasRs = true;
758   } else
759     MI.setOpcode(Mips::BNEZALC);
760 
761   if (HasRs)
762     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
763                                        Rs)));
764 
765   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
766                                      Rt)));
767   MI.addOperand(MCOperand::createImm(Imm));
768 
769   return MCDisassembler::Success;
770 }
771 
772 template <typename InsnType>
773 static DecodeStatus DecodePOP37GroupBranchMMR6(MCInst &MI, InsnType insn,
774                                                uint64_t Address,
775                                                const void *Decoder) {
776   InsnType Rt = fieldFromInstruction(insn, 21, 5);
777   InsnType Rs = fieldFromInstruction(insn, 16, 5);
778   int64_t Imm = 0;
779 
780   if (Rs >= Rt) {
781     MI.setOpcode(Mips::BNVC_MMR6);
782     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
783                                        Rt)));
784     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
785                                        Rs)));
786     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
787   } else if (Rs != 0 && Rs < Rt) {
788     MI.setOpcode(Mips::BNEC_MMR6);
789     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
790                                        Rs)));
791     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
792                                        Rt)));
793     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
794   } else {
795     MI.setOpcode(Mips::BNEZALC_MMR6);
796     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
797                                        Rt)));
798     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
799   }
800 
801   MI.addOperand(MCOperand::createImm(Imm));
802 
803   return MCDisassembler::Success;
804 }
805 
806 template <typename InsnType>
807 static DecodeStatus DecodePOP65GroupBranchMMR6(MCInst &MI, InsnType insn,
808                                                uint64_t Address,
809                                                const void *Decoder) {
810   // We have:
811   //    0b110101 ttttt sssss iiiiiiiiiiiiiiii
812   //      Invalid if rt == 0
813   //      BGTZC_MMR6   if rs == 0  && rt != 0
814   //      BLTZC_MMR6   if rs == rt && rt != 0
815   //      BLTC_MMR6    if rs != rt && rs != 0  && rt != 0
816 
817   InsnType Rt = fieldFromInstruction(insn, 21, 5);
818   InsnType Rs = fieldFromInstruction(insn, 16, 5);
819   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
820   bool HasRs = false;
821 
822   if (Rt == 0)
823     return MCDisassembler::Fail;
824   else if (Rs == 0)
825     MI.setOpcode(Mips::BGTZC_MMR6);
826   else if (Rs == Rt)
827     MI.setOpcode(Mips::BLTZC_MMR6);
828   else {
829     MI.setOpcode(Mips::BLTC_MMR6);
830     HasRs = true;
831   }
832 
833   if (HasRs)
834     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
835                                               Rs)));
836 
837   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
838                                      Rt)));
839 
840   MI.addOperand(MCOperand::createImm(Imm));
841 
842   return MCDisassembler::Success;
843 }
844 
845 template <typename InsnType>
846 static DecodeStatus DecodePOP75GroupBranchMMR6(MCInst &MI, InsnType insn,
847                                                uint64_t Address,
848                                                const void *Decoder) {
849   // We have:
850   //    0b111101 ttttt sssss iiiiiiiiiiiiiiii
851   //      Invalid if rt == 0
852   //      BLEZC_MMR6   if rs == 0  && rt != 0
853   //      BGEZC_MMR6   if rs == rt && rt != 0
854   //      BGEC_MMR6    if rs != rt && rs != 0  && rt != 0
855 
856   InsnType Rt = fieldFromInstruction(insn, 21, 5);
857   InsnType Rs = fieldFromInstruction(insn, 16, 5);
858   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
859   bool HasRs = false;
860 
861   if (Rt == 0)
862     return MCDisassembler::Fail;
863   else if (Rs == 0)
864     MI.setOpcode(Mips::BLEZC_MMR6);
865   else if (Rs == Rt)
866     MI.setOpcode(Mips::BGEZC_MMR6);
867   else {
868     HasRs = true;
869     MI.setOpcode(Mips::BGEC_MMR6);
870   }
871 
872   if (HasRs)
873     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
874                                        Rs)));
875 
876   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
877                                      Rt)));
878 
879   MI.addOperand(MCOperand::createImm(Imm));
880 
881   return MCDisassembler::Success;
882 }
883 
884 template <typename InsnType>
885 static DecodeStatus DecodeBlezlGroupBranch(MCInst &MI, InsnType insn,
886                                            uint64_t Address,
887                                            const void *Decoder) {
888   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
889   // (otherwise we would have matched the BLEZL instruction from the earlier
890   // ISA's instead).
891   //
892   // We have:
893   //    0b010110 sssss ttttt iiiiiiiiiiiiiiii
894   //      Invalid if rs == 0
895   //      BLEZC   if rs == 0  && rt != 0
896   //      BGEZC   if rs == rt && rt != 0
897   //      BGEC    if rs != rt && rs != 0  && rt != 0
898 
899   InsnType Rs = fieldFromInstruction(insn, 21, 5);
900   InsnType Rt = fieldFromInstruction(insn, 16, 5);
901   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
902   bool HasRs = false;
903 
904   if (Rt == 0)
905     return MCDisassembler::Fail;
906   else if (Rs == 0)
907     MI.setOpcode(Mips::BLEZC);
908   else if (Rs == Rt)
909     MI.setOpcode(Mips::BGEZC);
910   else {
911     HasRs = true;
912     MI.setOpcode(Mips::BGEC);
913   }
914 
915   if (HasRs)
916     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
917                                        Rs)));
918 
919   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
920                                      Rt)));
921 
922   MI.addOperand(MCOperand::createImm(Imm));
923 
924   return MCDisassembler::Success;
925 }
926 
927 template <typename InsnType>
928 static DecodeStatus DecodeBgtzlGroupBranch(MCInst &MI, InsnType insn,
929                                            uint64_t Address,
930                                            const void *Decoder) {
931   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
932   // (otherwise we would have matched the BGTZL instruction from the earlier
933   // ISA's instead).
934   //
935   // We have:
936   //    0b010111 sssss ttttt iiiiiiiiiiiiiiii
937   //      Invalid if rs == 0
938   //      BGTZC   if rs == 0  && rt != 0
939   //      BLTZC   if rs == rt && rt != 0
940   //      BLTC    if rs != rt && rs != 0  && rt != 0
941 
942   bool HasRs = false;
943 
944   InsnType Rs = fieldFromInstruction(insn, 21, 5);
945   InsnType Rt = fieldFromInstruction(insn, 16, 5);
946   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
947 
948   if (Rt == 0)
949     return MCDisassembler::Fail;
950   else if (Rs == 0)
951     MI.setOpcode(Mips::BGTZC);
952   else if (Rs == Rt)
953     MI.setOpcode(Mips::BLTZC);
954   else {
955     MI.setOpcode(Mips::BLTC);
956     HasRs = true;
957   }
958 
959   if (HasRs)
960     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
961                                               Rs)));
962 
963   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
964                                      Rt)));
965 
966   MI.addOperand(MCOperand::createImm(Imm));
967 
968   return MCDisassembler::Success;
969 }
970 
971 template <typename InsnType>
972 static DecodeStatus DecodeBgtzGroupBranch(MCInst &MI, InsnType insn,
973                                           uint64_t Address,
974                                           const void *Decoder) {
975   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
976   // (otherwise we would have matched the BGTZ instruction from the earlier
977   // ISA's instead).
978   //
979   // We have:
980   //    0b000111 sssss ttttt iiiiiiiiiiiiiiii
981   //      BGTZ    if rt == 0
982   //      BGTZALC if rs == 0 && rt != 0
983   //      BLTZALC if rs != 0 && rs == rt
984   //      BLTUC   if rs != 0 && rs != rt
985 
986   InsnType Rs = fieldFromInstruction(insn, 21, 5);
987   InsnType Rt = fieldFromInstruction(insn, 16, 5);
988   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
989   bool HasRs = false;
990   bool HasRt = false;
991 
992   if (Rt == 0) {
993     MI.setOpcode(Mips::BGTZ);
994     HasRs = true;
995   } else if (Rs == 0) {
996     MI.setOpcode(Mips::BGTZALC);
997     HasRt = true;
998   } else if (Rs == Rt) {
999     MI.setOpcode(Mips::BLTZALC);
1000     HasRs = true;
1001   } else {
1002     MI.setOpcode(Mips::BLTUC);
1003     HasRs = true;
1004     HasRt = true;
1005   }
1006 
1007   if (HasRs)
1008     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1009                                        Rs)));
1010 
1011   if (HasRt)
1012     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1013                                        Rt)));
1014 
1015   MI.addOperand(MCOperand::createImm(Imm));
1016 
1017   return MCDisassembler::Success;
1018 }
1019 
1020 template <typename InsnType>
1021 static DecodeStatus DecodeBlezGroupBranch(MCInst &MI, InsnType insn,
1022                                            uint64_t Address,
1023                                            const void *Decoder) {
1024   // If we are called then we can assume that MIPS32r6/MIPS64r6 is enabled
1025   // (otherwise we would have matched the BLEZL instruction from the earlier
1026   // ISA's instead).
1027   //
1028   // We have:
1029   //    0b000110 sssss ttttt iiiiiiiiiiiiiiii
1030   //      Invalid   if rs == 0
1031   //      BLEZALC   if rs == 0  && rt != 0
1032   //      BGEZALC   if rs == rt && rt != 0
1033   //      BGEUC     if rs != rt && rs != 0  && rt != 0
1034 
1035   InsnType Rs = fieldFromInstruction(insn, 21, 5);
1036   InsnType Rt = fieldFromInstruction(insn, 16, 5);
1037   int64_t Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
1038   bool HasRs = false;
1039 
1040   if (Rt == 0)
1041     return MCDisassembler::Fail;
1042   else if (Rs == 0)
1043     MI.setOpcode(Mips::BLEZALC);
1044   else if (Rs == Rt)
1045     MI.setOpcode(Mips::BGEZALC);
1046   else {
1047     HasRs = true;
1048     MI.setOpcode(Mips::BGEUC);
1049   }
1050 
1051   if (HasRs)
1052     MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1053                                        Rs)));
1054   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID,
1055                                      Rt)));
1056 
1057   MI.addOperand(MCOperand::createImm(Imm));
1058 
1059   return MCDisassembler::Success;
1060 }
1061 
1062 // Override the generated disassembler to produce DEXT all the time. This is
1063 // for feature / behaviour parity with  binutils.
1064 template <typename InsnType>
1065 static DecodeStatus DecodeDEXT(MCInst &MI, InsnType Insn, uint64_t Address,
1066                                const void *Decoder) {
1067   unsigned Msbd = fieldFromInstruction(Insn, 11, 5);
1068   unsigned Lsb = fieldFromInstruction(Insn, 6, 5);
1069   unsigned Size = 0;
1070   unsigned Pos = 0;
1071   bool IsMicroMips = false;
1072 
1073   switch (MI.getOpcode()) {
1074     case Mips::DEXT_MM64R6:
1075       IsMicroMips = true;
1076       LLVM_FALLTHROUGH;
1077     case Mips::DEXT:
1078       Pos = Lsb;
1079       Size = Msbd + 1;
1080       break;
1081     case Mips::DEXTM_MM64R6:
1082       IsMicroMips = true;
1083       LLVM_FALLTHROUGH;
1084     case Mips::DEXTM:
1085       Pos = Lsb;
1086       Size = Msbd + 1 + 32;
1087       break;
1088     case Mips::DEXTU_MM64R6:
1089       IsMicroMips = true;
1090       LLVM_FALLTHROUGH;
1091     case Mips::DEXTU:
1092       Pos = Lsb + 32;
1093       Size = Msbd + 1;
1094       break;
1095     default:
1096       llvm_unreachable("Unknown DEXT instruction!");
1097   }
1098 
1099   MI.setOpcode(IsMicroMips ? Mips::DEXT_MM64R6 : Mips::DEXT);
1100 
1101   // Although the format of the instruction is similar, rs and rt are swapped
1102   // for microMIPS64R6.
1103   InsnType Rs = fieldFromInstruction(Insn, 21, 5);
1104   InsnType Rt = fieldFromInstruction(Insn, 16, 5);
1105   if (IsMicroMips)
1106     std::swap(Rs, Rt);
1107 
1108   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rt)));
1109   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rs)));
1110   MI.addOperand(MCOperand::createImm(Pos));
1111   MI.addOperand(MCOperand::createImm(Size));
1112 
1113   return MCDisassembler::Success;
1114 }
1115 
1116 // Override the generated disassembler to produce DINS all the time. This is
1117 // for feature / behaviour parity with binutils.
1118 template <typename InsnType>
1119 static DecodeStatus DecodeDINS(MCInst &MI, InsnType Insn, uint64_t Address,
1120                                const void *Decoder) {
1121   unsigned Msbd = fieldFromInstruction(Insn, 11, 5);
1122   unsigned Lsb = fieldFromInstruction(Insn, 6, 5);
1123   unsigned Size = 0;
1124   unsigned Pos = 0;
1125   bool IsMicroMips = false;
1126 
1127   switch (MI.getOpcode()) {
1128     case Mips::DINS_MM64R6:
1129       IsMicroMips = true;
1130       LLVM_FALLTHROUGH;
1131     case Mips::DINS:
1132       Pos = Lsb;
1133       Size = Msbd + 1 - Pos;
1134       break;
1135     case Mips::DINSM_MM64R6:
1136       IsMicroMips = true;
1137       LLVM_FALLTHROUGH;
1138     case Mips::DINSM:
1139       Pos = Lsb;
1140       Size = Msbd + 33 - Pos;
1141       break;
1142     case Mips::DINSU_MM64R6:
1143       IsMicroMips = true;
1144       LLVM_FALLTHROUGH;
1145     case Mips::DINSU:
1146       Pos = Lsb + 32;
1147       // mbsd = pos + size - 33
1148       // mbsd - pos + 33 = size
1149       Size = Msbd + 33 - Pos;
1150       break;
1151     default:
1152       llvm_unreachable("Unknown DINS instruction!");
1153   }
1154 
1155   // Although the format of the instruction is similar, rs and rt are swapped
1156   // for microMIPS64R6.
1157   InsnType Rs = fieldFromInstruction(Insn, 21, 5);
1158   InsnType Rt = fieldFromInstruction(Insn, 16, 5);
1159   if (IsMicroMips)
1160     std::swap(Rs, Rt);
1161 
1162   MI.setOpcode(IsMicroMips ? Mips::DINS_MM64R6 : Mips::DINS);
1163   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rt)));
1164   MI.addOperand(MCOperand::createReg(getReg(Decoder, Mips::GPR64RegClassID, Rs)));
1165   MI.addOperand(MCOperand::createImm(Pos));
1166   MI.addOperand(MCOperand::createImm(Size));
1167 
1168   return MCDisassembler::Success;
1169 }
1170 /// Read two bytes from the ArrayRef and return 16 bit halfword sorted
1171 /// according to the given endianness.
1172 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
1173                                       uint64_t &Size, uint32_t &Insn,
1174                                       bool IsBigEndian) {
1175   // We want to read exactly 2 Bytes of data.
1176   if (Bytes.size() < 2) {
1177     Size = 0;
1178     return MCDisassembler::Fail;
1179   }
1180 
1181   if (IsBigEndian) {
1182     Insn = (Bytes[0] << 8) | Bytes[1];
1183   } else {
1184     Insn = (Bytes[1] << 8) | Bytes[0];
1185   }
1186 
1187   return MCDisassembler::Success;
1188 }
1189 
1190 /// Read four bytes from the ArrayRef and return 32 bit word sorted
1191 /// according to the given endianness.
1192 static DecodeStatus readInstruction32(ArrayRef<uint8_t> Bytes, uint64_t Address,
1193                                       uint64_t &Size, uint32_t &Insn,
1194                                       bool IsBigEndian, bool IsMicroMips) {
1195   // We want to read exactly 4 Bytes of data.
1196   if (Bytes.size() < 4) {
1197     Size = 0;
1198     return MCDisassembler::Fail;
1199   }
1200 
1201   // High 16 bits of a 32-bit microMIPS instruction (where the opcode is)
1202   // always precede the low 16 bits in the instruction stream (that is, they
1203   // are placed at lower addresses in the instruction stream).
1204   //
1205   // microMIPS byte ordering:
1206   //   Big-endian:    0 | 1 | 2 | 3
1207   //   Little-endian: 1 | 0 | 3 | 2
1208 
1209   if (IsBigEndian) {
1210     // Encoded as a big-endian 32-bit word in the stream.
1211     Insn =
1212         (Bytes[3] << 0) | (Bytes[2] << 8) | (Bytes[1] << 16) | (Bytes[0] << 24);
1213   } else {
1214     if (IsMicroMips) {
1215       Insn = (Bytes[2] << 0) | (Bytes[3] << 8) | (Bytes[0] << 16) |
1216              (Bytes[1] << 24);
1217     } else {
1218       Insn = (Bytes[0] << 0) | (Bytes[1] << 8) | (Bytes[2] << 16) |
1219              (Bytes[3] << 24);
1220     }
1221   }
1222 
1223   return MCDisassembler::Success;
1224 }
1225 
1226 DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
1227                                               ArrayRef<uint8_t> Bytes,
1228                                               uint64_t Address,
1229                                               raw_ostream &VStream,
1230                                               raw_ostream &CStream) const {
1231   uint32_t Insn;
1232   DecodeStatus Result;
1233   Size = 0;
1234 
1235   if (IsMicroMips) {
1236     Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian);
1237     if (Result == MCDisassembler::Fail)
1238       return MCDisassembler::Fail;
1239 
1240     if (hasMips32r6()) {
1241       DEBUG(dbgs() << "Trying MicroMipsR616 table (16-bit instructions):\n");
1242       // Calling the auto-generated decoder function for microMIPS32R6
1243       // (and microMIPS64R6) 16-bit instructions.
1244       Result = decodeInstruction(DecoderTableMicroMipsR616, Instr, Insn,
1245                                  Address, this, STI);
1246       if (Result != MCDisassembler::Fail) {
1247         Size = 2;
1248         return Result;
1249       }
1250     }
1251 
1252     DEBUG(dbgs() << "Trying MicroMips16 table (16-bit instructions):\n");
1253     // Calling the auto-generated decoder function for microMIPS 16-bit
1254     // instructions.
1255     Result = decodeInstruction(DecoderTableMicroMips16, Instr, Insn, Address,
1256                                this, STI);
1257     if (Result != MCDisassembler::Fail) {
1258       Size = 2;
1259       return Result;
1260     }
1261 
1262     Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, true);
1263     if (Result == MCDisassembler::Fail)
1264       return MCDisassembler::Fail;
1265 
1266     if (hasMips32r6()) {
1267       DEBUG(dbgs() << "Trying MicroMips32r632 table (32-bit instructions):\n");
1268       // Calling the auto-generated decoder function.
1269       Result = decodeInstruction(DecoderTableMicroMipsR632, Instr, Insn, Address,
1270                                  this, STI);
1271       if (Result != MCDisassembler::Fail) {
1272         Size = 4;
1273         return Result;
1274       }
1275     }
1276 
1277     DEBUG(dbgs() << "Trying MicroMips32 table (32-bit instructions):\n");
1278     // Calling the auto-generated decoder function.
1279     Result = decodeInstruction(DecoderTableMicroMips32, Instr, Insn, Address,
1280                                this, STI);
1281     if (Result != MCDisassembler::Fail) {
1282       Size = 4;
1283       return Result;
1284     }
1285 
1286     if (hasMips32r6() && isFP64()) {
1287       DEBUG(dbgs() << "Trying MicroMips32r6FP64 table (32-bit opcodes):\n");
1288       Result = decodeInstruction(DecoderTableMicroMips32r6FP6432, Instr, Insn,
1289                                  Address, this, STI);
1290       if (Result != MCDisassembler::Fail) {
1291         Size = 4;
1292         return Result;
1293       }
1294     }
1295 
1296     // This is an invalid instruction. Claim that the Size is 2 bytes. Since
1297     // microMIPS instructions have a minimum alignment of 2, the next 2 bytes
1298     // could form a valid instruction. The two bytes we rejected as an
1299     // instruction could have actually beeen an inline constant pool that is
1300     // unconditionally branched over.
1301     Size = 2;
1302     return MCDisassembler::Fail;
1303   }
1304 
1305   // Attempt to read the instruction so that we can attempt to decode it. If
1306   // the buffer is not 4 bytes long, let the higher level logic figure out
1307   // what to do with a size of zero and MCDisassembler::Fail.
1308   Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false);
1309   if (Result == MCDisassembler::Fail)
1310     return MCDisassembler::Fail;
1311 
1312   // The only instruction size for standard encoded MIPS.
1313   Size = 4;
1314 
1315   if (hasCOP3()) {
1316     DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n");
1317     Result =
1318         decodeInstruction(DecoderTableCOP3_32, Instr, Insn, Address, this, STI);
1319     if (Result != MCDisassembler::Fail)
1320       return Result;
1321   }
1322 
1323   if (hasMips32r6() && isGP64()) {
1324     DEBUG(dbgs() << "Trying Mips32r6_64r6 (GPR64) table (32-bit opcodes):\n");
1325     Result = decodeInstruction(DecoderTableMips32r6_64r6_GP6432, Instr, Insn,
1326                                Address, this, STI);
1327     if (Result != MCDisassembler::Fail)
1328       return Result;
1329   }
1330 
1331   if (hasMips32r6() && isPTR64()) {
1332     DEBUG(dbgs() << "Trying Mips32r6_64r6 (PTR64) table (32-bit opcodes):\n");
1333     Result = decodeInstruction(DecoderTableMips32r6_64r6_PTR6432, Instr, Insn,
1334                                Address, this, STI);
1335     if (Result != MCDisassembler::Fail)
1336       return Result;
1337   }
1338 
1339   if (hasMips32r6()) {
1340     DEBUG(dbgs() << "Trying Mips32r6_64r6 table (32-bit opcodes):\n");
1341     Result = decodeInstruction(DecoderTableMips32r6_64r632, Instr, Insn,
1342                                Address, this, STI);
1343     if (Result != MCDisassembler::Fail)
1344       return Result;
1345   }
1346 
1347   if (hasMips2() && isPTR64()) {
1348     DEBUG(dbgs() << "Trying Mips32r6_64r6 (PTR64) table (32-bit opcodes):\n");
1349     Result = decodeInstruction(DecoderTableMips32_64_PTR6432, Instr, Insn,
1350                                Address, this, STI);
1351     if (Result != MCDisassembler::Fail)
1352       return Result;
1353   }
1354 
1355   if (hasCnMips()) {
1356     DEBUG(dbgs() << "Trying CnMips table (32-bit opcodes):\n");
1357     Result = decodeInstruction(DecoderTableCnMips32, Instr, Insn,
1358                                Address, this, STI);
1359     if (Result != MCDisassembler::Fail)
1360       return Result;
1361   }
1362 
1363   if (isGP64()) {
1364     DEBUG(dbgs() << "Trying Mips64 (GPR64) table (32-bit opcodes):\n");
1365     Result = decodeInstruction(DecoderTableMips6432, Instr, Insn,
1366                                Address, this, STI);
1367     if (Result != MCDisassembler::Fail)
1368       return Result;
1369   }
1370 
1371   DEBUG(dbgs() << "Trying Mips table (32-bit opcodes):\n");
1372   // Calling the auto-generated decoder function.
1373   Result =
1374       decodeInstruction(DecoderTableMips32, Instr, Insn, Address, this, STI);
1375   if (Result != MCDisassembler::Fail)
1376     return Result;
1377 
1378   return MCDisassembler::Fail;
1379 }
1380 
1381 static DecodeStatus DecodeCPU16RegsRegisterClass(MCInst &Inst,
1382                                                  unsigned RegNo,
1383                                                  uint64_t Address,
1384                                                  const void *Decoder) {
1385   return MCDisassembler::Fail;
1386 }
1387 
1388 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst,
1389                                              unsigned RegNo,
1390                                              uint64_t Address,
1391                                              const void *Decoder) {
1392   if (RegNo > 31)
1393     return MCDisassembler::Fail;
1394 
1395   unsigned Reg = getReg(Decoder, Mips::GPR64RegClassID, RegNo);
1396   Inst.addOperand(MCOperand::createReg(Reg));
1397   return MCDisassembler::Success;
1398 }
1399 
1400 static DecodeStatus DecodeGPRMM16RegisterClass(MCInst &Inst,
1401                                                unsigned RegNo,
1402                                                uint64_t Address,
1403                                                const void *Decoder) {
1404   if (RegNo > 7)
1405     return MCDisassembler::Fail;
1406   unsigned Reg = getReg(Decoder, Mips::GPRMM16RegClassID, RegNo);
1407   Inst.addOperand(MCOperand::createReg(Reg));
1408   return MCDisassembler::Success;
1409 }
1410 
1411 static DecodeStatus DecodeGPRMM16ZeroRegisterClass(MCInst &Inst,
1412                                                    unsigned RegNo,
1413                                                    uint64_t Address,
1414                                                    const void *Decoder) {
1415   if (RegNo > 7)
1416     return MCDisassembler::Fail;
1417   unsigned Reg = getReg(Decoder, Mips::GPRMM16ZeroRegClassID, RegNo);
1418   Inst.addOperand(MCOperand::createReg(Reg));
1419   return MCDisassembler::Success;
1420 }
1421 
1422 static DecodeStatus DecodeGPRMM16MovePRegisterClass(MCInst &Inst,
1423                                                     unsigned RegNo,
1424                                                     uint64_t Address,
1425                                                     const void *Decoder) {
1426   if (RegNo > 7)
1427     return MCDisassembler::Fail;
1428   unsigned Reg = getReg(Decoder, Mips::GPRMM16MovePRegClassID, RegNo);
1429   Inst.addOperand(MCOperand::createReg(Reg));
1430   return MCDisassembler::Success;
1431 }
1432 
1433 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst,
1434                                              unsigned RegNo,
1435                                              uint64_t Address,
1436                                              const void *Decoder) {
1437   if (RegNo > 31)
1438     return MCDisassembler::Fail;
1439   unsigned Reg = getReg(Decoder, Mips::GPR32RegClassID, RegNo);
1440   Inst.addOperand(MCOperand::createReg(Reg));
1441   return MCDisassembler::Success;
1442 }
1443 
1444 static DecodeStatus DecodePtrRegisterClass(MCInst &Inst,
1445                                            unsigned RegNo,
1446                                            uint64_t Address,
1447                                            const void *Decoder) {
1448   if (static_cast<const MipsDisassembler *>(Decoder)->isGP64())
1449     return DecodeGPR64RegisterClass(Inst, RegNo, Address, Decoder);
1450 
1451   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1452 }
1453 
1454 static DecodeStatus DecodeDSPRRegisterClass(MCInst &Inst,
1455                                             unsigned RegNo,
1456                                             uint64_t Address,
1457                                             const void *Decoder) {
1458   return DecodeGPR32RegisterClass(Inst, RegNo, Address, Decoder);
1459 }
1460 
1461 static DecodeStatus DecodeFGR64RegisterClass(MCInst &Inst,
1462                                              unsigned RegNo,
1463                                              uint64_t Address,
1464                                              const void *Decoder) {
1465   if (RegNo > 31)
1466     return MCDisassembler::Fail;
1467 
1468   unsigned Reg = getReg(Decoder, Mips::FGR64RegClassID, RegNo);
1469   Inst.addOperand(MCOperand::createReg(Reg));
1470   return MCDisassembler::Success;
1471 }
1472 
1473 static DecodeStatus DecodeFGR32RegisterClass(MCInst &Inst,
1474                                              unsigned RegNo,
1475                                              uint64_t Address,
1476                                              const void *Decoder) {
1477   if (RegNo > 31)
1478     return MCDisassembler::Fail;
1479 
1480   unsigned Reg = getReg(Decoder, Mips::FGR32RegClassID, RegNo);
1481   Inst.addOperand(MCOperand::createReg(Reg));
1482   return MCDisassembler::Success;
1483 }
1484 
1485 static DecodeStatus DecodeCCRRegisterClass(MCInst &Inst,
1486                                            unsigned RegNo,
1487                                            uint64_t Address,
1488                                            const void *Decoder) {
1489   if (RegNo > 31)
1490     return MCDisassembler::Fail;
1491   unsigned Reg = getReg(Decoder, Mips::CCRRegClassID, RegNo);
1492   Inst.addOperand(MCOperand::createReg(Reg));
1493   return MCDisassembler::Success;
1494 }
1495 
1496 static DecodeStatus DecodeFCCRegisterClass(MCInst &Inst,
1497                                            unsigned RegNo,
1498                                            uint64_t Address,
1499                                            const void *Decoder) {
1500   if (RegNo > 7)
1501     return MCDisassembler::Fail;
1502   unsigned Reg = getReg(Decoder, Mips::FCCRegClassID, RegNo);
1503   Inst.addOperand(MCOperand::createReg(Reg));
1504   return MCDisassembler::Success;
1505 }
1506 
1507 static DecodeStatus DecodeFGRCCRegisterClass(MCInst &Inst, unsigned RegNo,
1508                                              uint64_t Address,
1509                                              const void *Decoder) {
1510   if (RegNo > 31)
1511     return MCDisassembler::Fail;
1512 
1513   unsigned Reg = getReg(Decoder, Mips::FGRCCRegClassID, RegNo);
1514   Inst.addOperand(MCOperand::createReg(Reg));
1515   return MCDisassembler::Success;
1516 }
1517 
1518 static DecodeStatus DecodeMem(MCInst &Inst,
1519                               unsigned Insn,
1520                               uint64_t Address,
1521                               const void *Decoder) {
1522   int Offset = SignExtend32<16>(Insn & 0xffff);
1523   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1524   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1525 
1526   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1527   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1528 
1529   if (Inst.getOpcode() == Mips::SC ||
1530       Inst.getOpcode() == Mips::SCD)
1531     Inst.addOperand(MCOperand::createReg(Reg));
1532 
1533   Inst.addOperand(MCOperand::createReg(Reg));
1534   Inst.addOperand(MCOperand::createReg(Base));
1535   Inst.addOperand(MCOperand::createImm(Offset));
1536 
1537   return MCDisassembler::Success;
1538 }
1539 
1540 static DecodeStatus DecodeMemEVA(MCInst &Inst,
1541                                  unsigned Insn,
1542                                  uint64_t Address,
1543                                  const void *Decoder) {
1544   int Offset = SignExtend32<9>(Insn >> 7);
1545   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1546   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1547 
1548   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1549   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1550 
1551    if (Inst.getOpcode() == Mips::SCE)
1552      Inst.addOperand(MCOperand::createReg(Reg));
1553 
1554   Inst.addOperand(MCOperand::createReg(Reg));
1555   Inst.addOperand(MCOperand::createReg(Base));
1556   Inst.addOperand(MCOperand::createImm(Offset));
1557 
1558   return MCDisassembler::Success;
1559 }
1560 
1561 static DecodeStatus DecodeLoadByte9(MCInst &Inst,
1562                                     unsigned Insn,
1563                                     uint64_t Address,
1564                                     const void *Decoder) {
1565   int Offset = SignExtend32<9>(Insn & 0x1ff);
1566   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1567   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1568 
1569   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1570   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1571 
1572   Inst.addOperand(MCOperand::createReg(Reg));
1573   Inst.addOperand(MCOperand::createReg(Base));
1574   Inst.addOperand(MCOperand::createImm(Offset));
1575 
1576   return MCDisassembler::Success;
1577 }
1578 
1579 static DecodeStatus DecodeLoadByte15(MCInst &Inst,
1580                                      unsigned Insn,
1581                                      uint64_t Address,
1582                                      const void *Decoder) {
1583   int Offset = SignExtend32<16>(Insn & 0xffff);
1584   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1585   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1586 
1587   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1588   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1589 
1590   Inst.addOperand(MCOperand::createReg(Reg));
1591   Inst.addOperand(MCOperand::createReg(Base));
1592   Inst.addOperand(MCOperand::createImm(Offset));
1593 
1594   return MCDisassembler::Success;
1595 }
1596 
1597 static DecodeStatus DecodeCacheOp(MCInst &Inst,
1598                               unsigned Insn,
1599                               uint64_t Address,
1600                               const void *Decoder) {
1601   int Offset = SignExtend32<16>(Insn & 0xffff);
1602   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1603   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1604 
1605   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1606 
1607   Inst.addOperand(MCOperand::createReg(Base));
1608   Inst.addOperand(MCOperand::createImm(Offset));
1609   Inst.addOperand(MCOperand::createImm(Hint));
1610 
1611   return MCDisassembler::Success;
1612 }
1613 
1614 static DecodeStatus DecodeCacheOpMM(MCInst &Inst,
1615                                     unsigned Insn,
1616                                     uint64_t Address,
1617                                     const void *Decoder) {
1618   int Offset = SignExtend32<12>(Insn & 0xfff);
1619   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1620   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1621 
1622   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1623 
1624   Inst.addOperand(MCOperand::createReg(Base));
1625   Inst.addOperand(MCOperand::createImm(Offset));
1626   Inst.addOperand(MCOperand::createImm(Hint));
1627 
1628   return MCDisassembler::Success;
1629 }
1630 
1631 static DecodeStatus DecodePrefeOpMM(MCInst &Inst,
1632                                     unsigned Insn,
1633                                     uint64_t Address,
1634                                     const void *Decoder) {
1635   int Offset = SignExtend32<9>(Insn & 0x1ff);
1636   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1637   unsigned Hint = fieldFromInstruction(Insn, 21, 5);
1638 
1639   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1640 
1641   Inst.addOperand(MCOperand::createReg(Base));
1642   Inst.addOperand(MCOperand::createImm(Offset));
1643   Inst.addOperand(MCOperand::createImm(Hint));
1644 
1645   return MCDisassembler::Success;
1646 }
1647 
1648 static DecodeStatus DecodeCacheeOp_CacheOpR6(MCInst &Inst,
1649                                              unsigned Insn,
1650                                              uint64_t Address,
1651                                              const void *Decoder) {
1652   int Offset = SignExtend32<9>(Insn >> 7);
1653   unsigned Hint = fieldFromInstruction(Insn, 16, 5);
1654   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1655 
1656   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1657 
1658   Inst.addOperand(MCOperand::createReg(Base));
1659   Inst.addOperand(MCOperand::createImm(Offset));
1660   Inst.addOperand(MCOperand::createImm(Hint));
1661 
1662   return MCDisassembler::Success;
1663 }
1664 
1665 static DecodeStatus DecodeStoreEvaOpMM(MCInst &Inst,
1666                                        unsigned Insn,
1667                                        uint64_t Address,
1668                                        const void *Decoder) {
1669   int Offset = SignExtend32<9>(Insn & 0x1ff);
1670   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1671   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1672 
1673   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1674   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1675 
1676   Inst.addOperand(MCOperand::createReg(Reg));
1677   Inst.addOperand(MCOperand::createReg(Base));
1678   Inst.addOperand(MCOperand::createImm(Offset));
1679 
1680   return MCDisassembler::Success;
1681 }
1682 
1683 static DecodeStatus DecodeSyncI(MCInst &Inst,
1684                               unsigned Insn,
1685                               uint64_t Address,
1686                               const void *Decoder) {
1687   int Offset = SignExtend32<16>(Insn & 0xffff);
1688   unsigned Base = fieldFromInstruction(Insn, 21, 5);
1689 
1690   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1691 
1692   Inst.addOperand(MCOperand::createReg(Base));
1693   Inst.addOperand(MCOperand::createImm(Offset));
1694 
1695   return MCDisassembler::Success;
1696 }
1697 
1698 static DecodeStatus DecodeSynciR6(MCInst &Inst,
1699                                   unsigned Insn,
1700                                   uint64_t Address,
1701                                   const void *Decoder) {
1702   int Immediate = SignExtend32<16>(Insn & 0xffff);
1703   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1704 
1705   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1706 
1707   Inst.addOperand(MCOperand::createReg(Base));
1708   Inst.addOperand(MCOperand::createImm(Immediate));
1709 
1710   return MCDisassembler::Success;
1711 }
1712 
1713 static DecodeStatus DecodeMSA128Mem(MCInst &Inst, unsigned Insn,
1714                                     uint64_t Address, const void *Decoder) {
1715   int Offset = SignExtend32<10>(fieldFromInstruction(Insn, 16, 10));
1716   unsigned Reg = fieldFromInstruction(Insn, 6, 5);
1717   unsigned Base = fieldFromInstruction(Insn, 11, 5);
1718 
1719   Reg = getReg(Decoder, Mips::MSA128BRegClassID, Reg);
1720   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1721 
1722   Inst.addOperand(MCOperand::createReg(Reg));
1723   Inst.addOperand(MCOperand::createReg(Base));
1724 
1725   // The immediate field of an LD/ST instruction is scaled which means it must
1726   // be multiplied (when decoding) by the size (in bytes) of the instructions'
1727   // data format.
1728   // .b - 1 byte
1729   // .h - 2 bytes
1730   // .w - 4 bytes
1731   // .d - 8 bytes
1732   switch(Inst.getOpcode())
1733   {
1734   default:
1735     assert(false && "Unexpected instruction");
1736     return MCDisassembler::Fail;
1737     break;
1738   case Mips::LD_B:
1739   case Mips::ST_B:
1740     Inst.addOperand(MCOperand::createImm(Offset));
1741     break;
1742   case Mips::LD_H:
1743   case Mips::ST_H:
1744     Inst.addOperand(MCOperand::createImm(Offset * 2));
1745     break;
1746   case Mips::LD_W:
1747   case Mips::ST_W:
1748     Inst.addOperand(MCOperand::createImm(Offset * 4));
1749     break;
1750   case Mips::LD_D:
1751   case Mips::ST_D:
1752     Inst.addOperand(MCOperand::createImm(Offset * 8));
1753     break;
1754   }
1755 
1756   return MCDisassembler::Success;
1757 }
1758 
1759 static DecodeStatus DecodeMemMMImm4(MCInst &Inst,
1760                                     unsigned Insn,
1761                                     uint64_t Address,
1762                                     const void *Decoder) {
1763   unsigned Offset = Insn & 0xf;
1764   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1765   unsigned Base = fieldFromInstruction(Insn, 4, 3);
1766 
1767   switch (Inst.getOpcode()) {
1768     case Mips::LBU16_MM:
1769     case Mips::LHU16_MM:
1770     case Mips::LW16_MM:
1771       if (DecodeGPRMM16RegisterClass(Inst, Reg, Address, Decoder)
1772             == MCDisassembler::Fail)
1773         return MCDisassembler::Fail;
1774       break;
1775     case Mips::SB16_MM:
1776     case Mips::SB16_MMR6:
1777     case Mips::SH16_MM:
1778     case Mips::SH16_MMR6:
1779     case Mips::SW16_MM:
1780     case Mips::SW16_MMR6:
1781       if (DecodeGPRMM16ZeroRegisterClass(Inst, Reg, Address, Decoder)
1782             == MCDisassembler::Fail)
1783         return MCDisassembler::Fail;
1784       break;
1785   }
1786 
1787   if (DecodeGPRMM16RegisterClass(Inst, Base, Address, Decoder)
1788         == MCDisassembler::Fail)
1789     return MCDisassembler::Fail;
1790 
1791   switch (Inst.getOpcode()) {
1792     case Mips::LBU16_MM:
1793       if (Offset == 0xf)
1794         Inst.addOperand(MCOperand::createImm(-1));
1795       else
1796         Inst.addOperand(MCOperand::createImm(Offset));
1797       break;
1798     case Mips::SB16_MM:
1799     case Mips::SB16_MMR6:
1800       Inst.addOperand(MCOperand::createImm(Offset));
1801       break;
1802     case Mips::LHU16_MM:
1803     case Mips::SH16_MM:
1804     case Mips::SH16_MMR6:
1805       Inst.addOperand(MCOperand::createImm(Offset << 1));
1806       break;
1807     case Mips::LW16_MM:
1808     case Mips::SW16_MM:
1809     case Mips::SW16_MMR6:
1810       Inst.addOperand(MCOperand::createImm(Offset << 2));
1811       break;
1812   }
1813 
1814   return MCDisassembler::Success;
1815 }
1816 
1817 static DecodeStatus DecodeMemMMSPImm5Lsl2(MCInst &Inst,
1818                                           unsigned Insn,
1819                                           uint64_t Address,
1820                                           const void *Decoder) {
1821   unsigned Offset = Insn & 0x1F;
1822   unsigned Reg = fieldFromInstruction(Insn, 5, 5);
1823 
1824   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1825 
1826   Inst.addOperand(MCOperand::createReg(Reg));
1827   Inst.addOperand(MCOperand::createReg(Mips::SP));
1828   Inst.addOperand(MCOperand::createImm(Offset << 2));
1829 
1830   return MCDisassembler::Success;
1831 }
1832 
1833 static DecodeStatus DecodeMemMMGPImm7Lsl2(MCInst &Inst,
1834                                           unsigned Insn,
1835                                           uint64_t Address,
1836                                           const void *Decoder) {
1837   unsigned Offset = Insn & 0x7F;
1838   unsigned Reg = fieldFromInstruction(Insn, 7, 3);
1839 
1840   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1841 
1842   Inst.addOperand(MCOperand::createReg(Reg));
1843   Inst.addOperand(MCOperand::createReg(Mips::GP));
1844   Inst.addOperand(MCOperand::createImm(Offset << 2));
1845 
1846   return MCDisassembler::Success;
1847 }
1848 
1849 static DecodeStatus DecodeMemMMReglistImm4Lsl2(MCInst &Inst,
1850                                                unsigned Insn,
1851                                                uint64_t Address,
1852                                                const void *Decoder) {
1853   int Offset;
1854   switch (Inst.getOpcode()) {
1855   case Mips::LWM16_MMR6:
1856   case Mips::SWM16_MMR6:
1857     Offset = fieldFromInstruction(Insn, 4, 4);
1858     break;
1859   default:
1860     Offset = SignExtend32<4>(Insn & 0xf);
1861     break;
1862   }
1863 
1864   if (DecodeRegListOperand16(Inst, Insn, Address, Decoder)
1865       == MCDisassembler::Fail)
1866     return MCDisassembler::Fail;
1867 
1868   Inst.addOperand(MCOperand::createReg(Mips::SP));
1869   Inst.addOperand(MCOperand::createImm(Offset << 2));
1870 
1871   return MCDisassembler::Success;
1872 }
1873 
1874 static DecodeStatus DecodeMemMMImm9(MCInst &Inst,
1875                                     unsigned Insn,
1876                                     uint64_t Address,
1877                                     const void *Decoder) {
1878   int Offset = SignExtend32<9>(Insn & 0x1ff);
1879   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1880   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1881 
1882   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1883   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1884 
1885   if (Inst.getOpcode() == Mips::SCE_MM)
1886     Inst.addOperand(MCOperand::createReg(Reg));
1887 
1888   Inst.addOperand(MCOperand::createReg(Reg));
1889   Inst.addOperand(MCOperand::createReg(Base));
1890   Inst.addOperand(MCOperand::createImm(Offset));
1891 
1892   return MCDisassembler::Success;
1893 }
1894 
1895 static DecodeStatus DecodeMemMMImm12(MCInst &Inst,
1896                                      unsigned Insn,
1897                                      uint64_t Address,
1898                                      const void *Decoder) {
1899   int Offset = SignExtend32<12>(Insn & 0x0fff);
1900   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1901   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1902 
1903   Reg = getReg(Decoder, Mips::GPR32RegClassID, Reg);
1904   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
1905 
1906   switch (Inst.getOpcode()) {
1907   case Mips::SWM32_MM:
1908   case Mips::LWM32_MM:
1909     if (DecodeRegListOperand(Inst, Insn, Address, Decoder)
1910         == MCDisassembler::Fail)
1911       return MCDisassembler::Fail;
1912     Inst.addOperand(MCOperand::createReg(Base));
1913     Inst.addOperand(MCOperand::createImm(Offset));
1914     break;
1915   case Mips::SC_MM:
1916     Inst.addOperand(MCOperand::createReg(Reg));
1917     LLVM_FALLTHROUGH;
1918   default:
1919     Inst.addOperand(MCOperand::createReg(Reg));
1920     if (Inst.getOpcode() == Mips::LWP_MM || Inst.getOpcode() == Mips::SWP_MM ||
1921         Inst.getOpcode() == Mips::LWP_MMR6 || Inst.getOpcode() == Mips::SWP_MMR6)
1922       Inst.addOperand(MCOperand::createReg(Reg+1));
1923 
1924     Inst.addOperand(MCOperand::createReg(Base));
1925     Inst.addOperand(MCOperand::createImm(Offset));
1926   }
1927 
1928   return MCDisassembler::Success;
1929 }
1930 
1931 static DecodeStatus DecodeMemMMImm16(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, 21, 5);
1937   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1938 
1939   Reg = getReg(Decoder, Mips::GPR32RegClassID, 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 DecodeFMem(MCInst &Inst,
1950                                unsigned Insn,
1951                                uint64_t Address,
1952                                const void *Decoder) {
1953   int Offset = SignExtend32<16>(Insn & 0xffff);
1954   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
1955   unsigned Base = 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 DecodeFMemMMR2(MCInst &Inst, unsigned Insn,
1968                                    uint64_t Address, const void *Decoder) {
1969   // This function is the same as DecodeFMem but with the Reg and Base fields
1970   // swapped according to microMIPS spec.
1971   int Offset = SignExtend32<16>(Insn & 0xffff);
1972   unsigned Base = fieldFromInstruction(Insn, 16, 5);
1973   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
1974 
1975   Reg = getReg(Decoder, Mips::FGR64RegClassID, 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 DecodeFMem2(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::COP2RegClassID, 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 DecodeFMem3(MCInst &Inst,
2004                                unsigned Insn,
2005                                uint64_t Address,
2006                                const void *Decoder) {
2007   int Offset = SignExtend32<16>(Insn & 0xffff);
2008   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
2009   unsigned Base = fieldFromInstruction(Insn, 21, 5);
2010 
2011   Reg = getReg(Decoder, Mips::COP3RegClassID, 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 DecodeFMemCop2R6(MCInst &Inst,
2022                                     unsigned Insn,
2023                                     uint64_t Address,
2024                                     const void *Decoder) {
2025   int Offset = SignExtend32<11>(Insn & 0x07ff);
2026   unsigned Reg = fieldFromInstruction(Insn, 16, 5);
2027   unsigned Base = fieldFromInstruction(Insn, 11, 5);
2028 
2029   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
2030   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2031 
2032   Inst.addOperand(MCOperand::createReg(Reg));
2033   Inst.addOperand(MCOperand::createReg(Base));
2034   Inst.addOperand(MCOperand::createImm(Offset));
2035 
2036   return MCDisassembler::Success;
2037 }
2038 
2039 static DecodeStatus DecodeFMemCop2MMR6(MCInst &Inst, unsigned Insn,
2040                                        uint64_t Address, const void *Decoder) {
2041   int Offset = SignExtend32<11>(Insn & 0x07ff);
2042   unsigned Reg = fieldFromInstruction(Insn, 21, 5);
2043   unsigned Base = fieldFromInstruction(Insn, 16, 5);
2044 
2045   Reg = getReg(Decoder, Mips::COP2RegClassID, Reg);
2046   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2047 
2048   Inst.addOperand(MCOperand::createReg(Reg));
2049   Inst.addOperand(MCOperand::createReg(Base));
2050   Inst.addOperand(MCOperand::createImm(Offset));
2051 
2052   return MCDisassembler::Success;
2053 }
2054 
2055 static DecodeStatus DecodeSpecial3LlSc(MCInst &Inst,
2056                                        unsigned Insn,
2057                                        uint64_t Address,
2058                                        const void *Decoder) {
2059   int64_t Offset = SignExtend64<9>((Insn >> 7) & 0x1ff);
2060   unsigned Rt = fieldFromInstruction(Insn, 16, 5);
2061   unsigned Base = fieldFromInstruction(Insn, 21, 5);
2062 
2063   Rt = getReg(Decoder, Mips::GPR32RegClassID, Rt);
2064   Base = getReg(Decoder, Mips::GPR32RegClassID, Base);
2065 
2066   if(Inst.getOpcode() == Mips::SC_R6 || Inst.getOpcode() == Mips::SCD_R6){
2067     Inst.addOperand(MCOperand::createReg(Rt));
2068   }
2069 
2070   Inst.addOperand(MCOperand::createReg(Rt));
2071   Inst.addOperand(MCOperand::createReg(Base));
2072   Inst.addOperand(MCOperand::createImm(Offset));
2073 
2074   return MCDisassembler::Success;
2075 }
2076 
2077 static DecodeStatus DecodeHWRegsRegisterClass(MCInst &Inst,
2078                                               unsigned RegNo,
2079                                               uint64_t Address,
2080                                               const void *Decoder) {
2081   // Currently only hardware register 29 is supported.
2082   if (RegNo != 29)
2083     return  MCDisassembler::Fail;
2084   Inst.addOperand(MCOperand::createReg(Mips::HWR29));
2085   return MCDisassembler::Success;
2086 }
2087 
2088 static DecodeStatus DecodeAFGR64RegisterClass(MCInst &Inst,
2089                                               unsigned RegNo,
2090                                               uint64_t Address,
2091                                               const void *Decoder) {
2092   if (RegNo > 30 || RegNo %2)
2093     return MCDisassembler::Fail;
2094 
2095   unsigned Reg = getReg(Decoder, Mips::AFGR64RegClassID, RegNo /2);
2096   Inst.addOperand(MCOperand::createReg(Reg));
2097   return MCDisassembler::Success;
2098 }
2099 
2100 static DecodeStatus DecodeACC64DSPRegisterClass(MCInst &Inst,
2101                                                 unsigned RegNo,
2102                                                 uint64_t Address,
2103                                                 const void *Decoder) {
2104   if (RegNo >= 4)
2105     return MCDisassembler::Fail;
2106 
2107   unsigned Reg = getReg(Decoder, Mips::ACC64DSPRegClassID, RegNo);
2108   Inst.addOperand(MCOperand::createReg(Reg));
2109   return MCDisassembler::Success;
2110 }
2111 
2112 static DecodeStatus DecodeHI32DSPRegisterClass(MCInst &Inst,
2113                                                unsigned RegNo,
2114                                                uint64_t Address,
2115                                                const void *Decoder) {
2116   if (RegNo >= 4)
2117     return MCDisassembler::Fail;
2118 
2119   unsigned Reg = getReg(Decoder, Mips::HI32DSPRegClassID, RegNo);
2120   Inst.addOperand(MCOperand::createReg(Reg));
2121   return MCDisassembler::Success;
2122 }
2123 
2124 static DecodeStatus DecodeLO32DSPRegisterClass(MCInst &Inst,
2125                                                unsigned RegNo,
2126                                                uint64_t Address,
2127                                                const void *Decoder) {
2128   if (RegNo >= 4)
2129     return MCDisassembler::Fail;
2130 
2131   unsigned Reg = getReg(Decoder, Mips::LO32DSPRegClassID, RegNo);
2132   Inst.addOperand(MCOperand::createReg(Reg));
2133   return MCDisassembler::Success;
2134 }
2135 
2136 static DecodeStatus DecodeMSA128BRegisterClass(MCInst &Inst,
2137                                                unsigned RegNo,
2138                                                uint64_t Address,
2139                                                const void *Decoder) {
2140   if (RegNo > 31)
2141     return MCDisassembler::Fail;
2142 
2143   unsigned Reg = getReg(Decoder, Mips::MSA128BRegClassID, RegNo);
2144   Inst.addOperand(MCOperand::createReg(Reg));
2145   return MCDisassembler::Success;
2146 }
2147 
2148 static DecodeStatus DecodeMSA128HRegisterClass(MCInst &Inst,
2149                                                unsigned RegNo,
2150                                                uint64_t Address,
2151                                                const void *Decoder) {
2152   if (RegNo > 31)
2153     return MCDisassembler::Fail;
2154 
2155   unsigned Reg = getReg(Decoder, Mips::MSA128HRegClassID, RegNo);
2156   Inst.addOperand(MCOperand::createReg(Reg));
2157   return MCDisassembler::Success;
2158 }
2159 
2160 static DecodeStatus DecodeMSA128WRegisterClass(MCInst &Inst,
2161                                                unsigned RegNo,
2162                                                uint64_t Address,
2163                                                const void *Decoder) {
2164   if (RegNo > 31)
2165     return MCDisassembler::Fail;
2166 
2167   unsigned Reg = getReg(Decoder, Mips::MSA128WRegClassID, RegNo);
2168   Inst.addOperand(MCOperand::createReg(Reg));
2169   return MCDisassembler::Success;
2170 }
2171 
2172 static DecodeStatus DecodeMSA128DRegisterClass(MCInst &Inst,
2173                                                unsigned RegNo,
2174                                                uint64_t Address,
2175                                                const void *Decoder) {
2176   if (RegNo > 31)
2177     return MCDisassembler::Fail;
2178 
2179   unsigned Reg = getReg(Decoder, Mips::MSA128DRegClassID, RegNo);
2180   Inst.addOperand(MCOperand::createReg(Reg));
2181   return MCDisassembler::Success;
2182 }
2183 
2184 static DecodeStatus DecodeMSACtrlRegisterClass(MCInst &Inst,
2185                                                unsigned RegNo,
2186                                                uint64_t Address,
2187                                                const void *Decoder) {
2188   if (RegNo > 7)
2189     return MCDisassembler::Fail;
2190 
2191   unsigned Reg = getReg(Decoder, Mips::MSACtrlRegClassID, RegNo);
2192   Inst.addOperand(MCOperand::createReg(Reg));
2193   return MCDisassembler::Success;
2194 }
2195 
2196 static DecodeStatus DecodeCOP0RegisterClass(MCInst &Inst,
2197                                             unsigned RegNo,
2198                                             uint64_t Address,
2199                                             const void *Decoder) {
2200   if (RegNo > 31)
2201     return MCDisassembler::Fail;
2202 
2203   unsigned Reg = getReg(Decoder, Mips::COP0RegClassID, RegNo);
2204   Inst.addOperand(MCOperand::createReg(Reg));
2205   return MCDisassembler::Success;
2206 }
2207 
2208 static DecodeStatus DecodeCOP2RegisterClass(MCInst &Inst,
2209                                             unsigned RegNo,
2210                                             uint64_t Address,
2211                                             const void *Decoder) {
2212   if (RegNo > 31)
2213     return MCDisassembler::Fail;
2214 
2215   unsigned Reg = getReg(Decoder, Mips::COP2RegClassID, RegNo);
2216   Inst.addOperand(MCOperand::createReg(Reg));
2217   return MCDisassembler::Success;
2218 }
2219 
2220 static DecodeStatus DecodeBranchTarget(MCInst &Inst,
2221                                        unsigned Offset,
2222                                        uint64_t Address,
2223                                        const void *Decoder) {
2224   int32_t BranchOffset = (SignExtend32<16>(Offset) * 4) + 4;
2225   Inst.addOperand(MCOperand::createImm(BranchOffset));
2226   return MCDisassembler::Success;
2227 }
2228 
2229 static DecodeStatus DecodeBranchTarget1SImm16(MCInst &Inst,
2230                                               unsigned Offset,
2231                                               uint64_t Address,
2232                                               const void *Decoder) {
2233   int32_t BranchOffset = (SignExtend32<16>(Offset) * 2);
2234   Inst.addOperand(MCOperand::createImm(BranchOffset));
2235   return MCDisassembler::Success;
2236 }
2237 
2238 static DecodeStatus DecodeJumpTarget(MCInst &Inst,
2239                                      unsigned Insn,
2240                                      uint64_t Address,
2241                                      const void *Decoder) {
2242   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 2;
2243   Inst.addOperand(MCOperand::createImm(JumpOffset));
2244   return MCDisassembler::Success;
2245 }
2246 
2247 static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
2248                                          unsigned Offset,
2249                                          uint64_t Address,
2250                                          const void *Decoder) {
2251   int32_t BranchOffset = SignExtend32<21>(Offset) * 4 + 4;
2252 
2253   Inst.addOperand(MCOperand::createImm(BranchOffset));
2254   return MCDisassembler::Success;
2255 }
2256 
2257 static DecodeStatus DecodeBranchTarget21MM(MCInst &Inst,
2258                                            unsigned Offset,
2259                                            uint64_t Address,
2260                                            const void *Decoder) {
2261   int32_t BranchOffset = SignExtend32<21>(Offset) * 4 + 4;
2262 
2263   Inst.addOperand(MCOperand::createImm(BranchOffset));
2264   return MCDisassembler::Success;
2265 }
2266 
2267 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
2268                                          unsigned Offset,
2269                                          uint64_t Address,
2270                                          const void *Decoder) {
2271   int32_t BranchOffset = SignExtend32<26>(Offset) * 4 + 4;
2272 
2273   Inst.addOperand(MCOperand::createImm(BranchOffset));
2274   return MCDisassembler::Success;
2275 }
2276 
2277 static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
2278                                           unsigned Offset,
2279                                           uint64_t Address,
2280                                           const void *Decoder) {
2281   int32_t BranchOffset = SignExtend32<8>(Offset << 1);
2282   Inst.addOperand(MCOperand::createImm(BranchOffset));
2283   return MCDisassembler::Success;
2284 }
2285 
2286 static DecodeStatus DecodeBranchTarget10MM(MCInst &Inst,
2287                                            unsigned Offset,
2288                                            uint64_t Address,
2289                                            const void *Decoder) {
2290   int32_t BranchOffset = SignExtend32<11>(Offset << 1);
2291   Inst.addOperand(MCOperand::createImm(BranchOffset));
2292   return MCDisassembler::Success;
2293 }
2294 
2295 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
2296                                          unsigned Offset,
2297                                          uint64_t Address,
2298                                          const void *Decoder) {
2299   int32_t BranchOffset = SignExtend32<16>(Offset) * 2 + 4;
2300   Inst.addOperand(MCOperand::createImm(BranchOffset));
2301   return MCDisassembler::Success;
2302 }
2303 
2304 static DecodeStatus DecodeBranchTarget26MM(MCInst &Inst,
2305   unsigned Offset,
2306   uint64_t Address,
2307   const void *Decoder) {
2308   int32_t BranchOffset = SignExtend32<27>(Offset << 1);
2309 
2310   Inst.addOperand(MCOperand::createImm(BranchOffset));
2311   return MCDisassembler::Success;
2312 }
2313 
2314 static DecodeStatus DecodeJumpTargetMM(MCInst &Inst,
2315                                        unsigned Insn,
2316                                        uint64_t Address,
2317                                        const void *Decoder) {
2318   unsigned JumpOffset = fieldFromInstruction(Insn, 0, 26) << 1;
2319   Inst.addOperand(MCOperand::createImm(JumpOffset));
2320   return MCDisassembler::Success;
2321 }
2322 
2323 static DecodeStatus DecodeAddiur2Simm7(MCInst &Inst,
2324                                        unsigned Value,
2325                                        uint64_t Address,
2326                                        const void *Decoder) {
2327   if (Value == 0)
2328     Inst.addOperand(MCOperand::createImm(1));
2329   else if (Value == 0x7)
2330     Inst.addOperand(MCOperand::createImm(-1));
2331   else
2332     Inst.addOperand(MCOperand::createImm(Value << 2));
2333   return MCDisassembler::Success;
2334 }
2335 
2336 static DecodeStatus DecodeLi16Imm(MCInst &Inst,
2337                                   unsigned Value,
2338                                   uint64_t Address,
2339                                   const void *Decoder) {
2340   if (Value == 0x7F)
2341     Inst.addOperand(MCOperand::createImm(-1));
2342   else
2343     Inst.addOperand(MCOperand::createImm(Value));
2344   return MCDisassembler::Success;
2345 }
2346 
2347 static DecodeStatus DecodePOOL16BEncodedField(MCInst &Inst,
2348                                               unsigned Value,
2349                                               uint64_t Address,
2350                                               const void *Decoder) {
2351   Inst.addOperand(MCOperand::createImm(Value == 0x0 ? 8 : Value));
2352   return MCDisassembler::Success;
2353 }
2354 
2355 template <unsigned Bits, int Offset, int Scale>
2356 static DecodeStatus DecodeUImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
2357                                                  uint64_t Address,
2358                                                  const void *Decoder) {
2359   Value &= ((1 << Bits) - 1);
2360   Value *= Scale;
2361   Inst.addOperand(MCOperand::createImm(Value + Offset));
2362   return MCDisassembler::Success;
2363 }
2364 
2365 template <unsigned Bits, int Offset, int ScaleBy>
2366 static DecodeStatus DecodeSImmWithOffsetAndScale(MCInst &Inst, unsigned Value,
2367                                                  uint64_t Address,
2368                                                  const void *Decoder) {
2369   int32_t Imm = SignExtend32<Bits>(Value) * ScaleBy;
2370   Inst.addOperand(MCOperand::createImm(Imm + Offset));
2371   return MCDisassembler::Success;
2372 }
2373 
2374 static DecodeStatus DecodeInsSize(MCInst &Inst,
2375                                   unsigned Insn,
2376                                   uint64_t Address,
2377                                   const void *Decoder) {
2378   // First we need to grab the pos(lsb) from MCInst.
2379   // This function only handles the 32 bit variants of ins, as dins
2380   // variants are handled differently.
2381   int Pos = Inst.getOperand(2).getImm();
2382   int Size = (int) Insn - Pos + 1;
2383   Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Size)));
2384   return MCDisassembler::Success;
2385 }
2386 
2387 static DecodeStatus DecodeSimm19Lsl2(MCInst &Inst, unsigned Insn,
2388                                      uint64_t Address, const void *Decoder) {
2389   Inst.addOperand(MCOperand::createImm(SignExtend32<19>(Insn) * 4));
2390   return MCDisassembler::Success;
2391 }
2392 
2393 static DecodeStatus DecodeSimm18Lsl3(MCInst &Inst, unsigned Insn,
2394                                      uint64_t Address, const void *Decoder) {
2395   Inst.addOperand(MCOperand::createImm(SignExtend32<18>(Insn) * 8));
2396   return MCDisassembler::Success;
2397 }
2398 
2399 static DecodeStatus DecodeSimm9SP(MCInst &Inst, unsigned Insn,
2400                                   uint64_t Address, const void *Decoder) {
2401   int32_t DecodedValue;
2402   switch (Insn) {
2403   case 0: DecodedValue = 256; break;
2404   case 1: DecodedValue = 257; break;
2405   case 510: DecodedValue = -258; break;
2406   case 511: DecodedValue = -257; break;
2407   default: DecodedValue = SignExtend32<9>(Insn); break;
2408   }
2409   Inst.addOperand(MCOperand::createImm(DecodedValue * 4));
2410   return MCDisassembler::Success;
2411 }
2412 
2413 static DecodeStatus DecodeANDI16Imm(MCInst &Inst, unsigned Insn,
2414                                     uint64_t Address, const void *Decoder) {
2415   // Insn must be >= 0, since it is unsigned that condition is always true.
2416   assert(Insn < 16);
2417   int32_t DecodedValues[] = {128, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64,
2418                              255, 32768, 65535};
2419   Inst.addOperand(MCOperand::createImm(DecodedValues[Insn]));
2420   return MCDisassembler::Success;
2421 }
2422 
2423 static DecodeStatus DecodeRegListOperand(MCInst &Inst,
2424                                          unsigned Insn,
2425                                          uint64_t Address,
2426                                          const void *Decoder) {
2427   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5,
2428                      Mips::S6, Mips::S7, Mips::FP};
2429   unsigned RegNum;
2430 
2431   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
2432 
2433   // Empty register lists are not allowed.
2434   if (RegLst == 0)
2435     return MCDisassembler::Fail;
2436 
2437   RegNum = RegLst & 0xf;
2438 
2439   // RegLst values 10-15, and 26-31 are reserved.
2440   if (RegNum > 9)
2441     return MCDisassembler::Fail;
2442 
2443   for (unsigned i = 0; i < RegNum; i++)
2444     Inst.addOperand(MCOperand::createReg(Regs[i]));
2445 
2446   if (RegLst & 0x10)
2447     Inst.addOperand(MCOperand::createReg(Mips::RA));
2448 
2449   return MCDisassembler::Success;
2450 }
2451 
2452 static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
2453                                            uint64_t Address,
2454                                            const void *Decoder) {
2455   unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
2456   unsigned RegLst;
2457   switch(Inst.getOpcode()) {
2458   default:
2459     RegLst = fieldFromInstruction(Insn, 4, 2);
2460     break;
2461   case Mips::LWM16_MMR6:
2462   case Mips::SWM16_MMR6:
2463     RegLst = fieldFromInstruction(Insn, 8, 2);
2464     break;
2465   }
2466   unsigned RegNum = RegLst & 0x3;
2467 
2468   for (unsigned i = 0; i <= RegNum; i++)
2469     Inst.addOperand(MCOperand::createReg(Regs[i]));
2470 
2471   Inst.addOperand(MCOperand::createReg(Mips::RA));
2472 
2473   return MCDisassembler::Success;
2474 }
2475 
2476 static DecodeStatus DecodeMovePRegPair(MCInst &Inst, unsigned Insn,
2477                                        uint64_t Address, const void *Decoder) {
2478   unsigned RegPair = fieldFromInstruction(Insn, 7, 3);
2479 
2480   switch (RegPair) {
2481   default:
2482     return MCDisassembler::Fail;
2483   case 0:
2484     Inst.addOperand(MCOperand::createReg(Mips::A1));
2485     Inst.addOperand(MCOperand::createReg(Mips::A2));
2486     break;
2487   case 1:
2488     Inst.addOperand(MCOperand::createReg(Mips::A1));
2489     Inst.addOperand(MCOperand::createReg(Mips::A3));
2490     break;
2491   case 2:
2492     Inst.addOperand(MCOperand::createReg(Mips::A2));
2493     Inst.addOperand(MCOperand::createReg(Mips::A3));
2494     break;
2495   case 3:
2496     Inst.addOperand(MCOperand::createReg(Mips::A0));
2497     Inst.addOperand(MCOperand::createReg(Mips::S5));
2498     break;
2499   case 4:
2500     Inst.addOperand(MCOperand::createReg(Mips::A0));
2501     Inst.addOperand(MCOperand::createReg(Mips::S6));
2502     break;
2503   case 5:
2504     Inst.addOperand(MCOperand::createReg(Mips::A0));
2505     Inst.addOperand(MCOperand::createReg(Mips::A1));
2506     break;
2507   case 6:
2508     Inst.addOperand(MCOperand::createReg(Mips::A0));
2509     Inst.addOperand(MCOperand::createReg(Mips::A2));
2510     break;
2511   case 7:
2512     Inst.addOperand(MCOperand::createReg(Mips::A0));
2513     Inst.addOperand(MCOperand::createReg(Mips::A3));
2514     break;
2515   }
2516 
2517   return MCDisassembler::Success;
2518 }
2519 
2520 static DecodeStatus DecodeSimm23Lsl2(MCInst &Inst, unsigned Insn,
2521                                      uint64_t Address, const void *Decoder) {
2522   Inst.addOperand(MCOperand::createImm(SignExtend32<25>(Insn << 2)));
2523   return MCDisassembler::Success;
2524 }
2525 
2526 template <typename InsnType>
2527 static DecodeStatus DecodeBgtzGroupBranchMMR6(MCInst &MI, InsnType insn,
2528   uint64_t Address,
2529   const void *Decoder) {
2530   // We have:
2531   //    0b000111 ttttt sssss iiiiiiiiiiiiiiii
2532   //      Invalid      if rt == 0
2533   //      BGTZALC_MMR6 if rs == 0 && rt != 0
2534   //      BLTZALC_MMR6 if rs != 0 && rs == rt
2535   //      BLTUC_MMR6   if rs != 0 && rs != rt
2536 
2537   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2538   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2539   InsnType Imm = 0;
2540   bool HasRs = false;
2541   bool HasRt = false;
2542 
2543   if (Rt == 0)
2544     return MCDisassembler::Fail;
2545   else if (Rs == 0) {
2546     MI.setOpcode(Mips::BGTZALC_MMR6);
2547     HasRt = true;
2548     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2549   }
2550   else if (Rs == Rt) {
2551     MI.setOpcode(Mips::BLTZALC_MMR6);
2552     HasRs = true;
2553     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2554   }
2555   else {
2556     MI.setOpcode(Mips::BLTUC_MMR6);
2557     HasRs = true;
2558     HasRt = true;
2559     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
2560   }
2561 
2562   if (HasRs)
2563     MI.addOperand(
2564     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2565 
2566   if (HasRt)
2567     MI.addOperand(
2568     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2569 
2570   MI.addOperand(MCOperand::createImm(Imm));
2571 
2572   return MCDisassembler::Success;
2573 }
2574 
2575 template <typename InsnType>
2576 static DecodeStatus DecodeBlezGroupBranchMMR6(MCInst &MI, InsnType insn,
2577   uint64_t Address,
2578   const void *Decoder) {
2579   // We have:
2580   //    0b000110 ttttt sssss iiiiiiiiiiiiiiii
2581   //      Invalid        if rt == 0
2582   //      BLEZALC_MMR6   if rs == 0  && rt != 0
2583   //      BGEZALC_MMR6   if rs == rt && rt != 0
2584   //      BGEUC_MMR6     if rs != rt && rs != 0  && rt != 0
2585 
2586   InsnType Rt = fieldFromInstruction(insn, 21, 5);
2587   InsnType Rs = fieldFromInstruction(insn, 16, 5);
2588   InsnType Imm = 0;
2589   bool HasRs = false;
2590 
2591   if (Rt == 0)
2592     return MCDisassembler::Fail;
2593   else if (Rs == 0) {
2594     MI.setOpcode(Mips::BLEZALC_MMR6);
2595     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2596   }
2597   else if (Rs == Rt) {
2598     MI.setOpcode(Mips::BGEZALC_MMR6);
2599     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 2 + 4;
2600   }
2601   else {
2602     HasRs = true;
2603     MI.setOpcode(Mips::BGEUC_MMR6);
2604     Imm = SignExtend64(fieldFromInstruction(insn, 0, 16), 16) * 4 + 4;
2605   }
2606 
2607   if (HasRs)
2608     MI.addOperand(
2609     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rs)));
2610   MI.addOperand(
2611     MCOperand::createReg(getReg(Decoder, Mips::GPR32RegClassID, Rt)));
2612 
2613   MI.addOperand(MCOperand::createImm(Imm));
2614 
2615   return MCDisassembler::Success;
2616 }
2617