summaryrefslogtreecommitdiff
path: root/lib/Target/MBlaze/Disassembler/MBlazeDisassembler.cpp
blob: ccc3a05f5076be46f8f3cc6d676d6a3bfc1b85c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
//===- MBlazeDisassembler.cpp - Disassembler for MicroBlaze  ----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is part of the MBlaze Disassembler. It contains code to translate
// the data produced by the decoder into MCInsts.
//
//===----------------------------------------------------------------------===//

#include "MBlaze.h"
#include "MBlazeDisassembler.h"

#include "llvm/MC/EDInstInfo.h"
#include "llvm/MC/MCDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"

// #include "MBlazeGenDecoderTables.inc"
// #include "MBlazeGenRegisterNames.inc"
#include "MBlazeGenEDInfo.inc"

namespace llvm {
extern const MCInstrDesc MBlazeInsts[];
}

using namespace llvm;

const unsigned UNSUPPORTED = -1;

static const unsigned mblazeBinary2Opcode[] = {
  MBlaze::ADD,   MBlaze::RSUB,   MBlaze::ADDC,   MBlaze::RSUBC,   //00,01,02,03
  MBlaze::ADDK,  MBlaze::RSUBK,  MBlaze::ADDKC,  MBlaze::RSUBKC,  //04,05,06,07
  MBlaze::ADDI,  MBlaze::RSUBI,  MBlaze::ADDIC,  MBlaze::RSUBIC,  //08,09,0A,0B
  MBlaze::ADDIK, MBlaze::RSUBIK, MBlaze::ADDIKC, MBlaze::RSUBIKC, //0C,0D,0E,0F

  MBlaze::MUL,   MBlaze::BSRL,   MBlaze::IDIV,   MBlaze::GETD,    //10,11,12,13
  UNSUPPORTED,   UNSUPPORTED,    MBlaze::FADD,   UNSUPPORTED,     //14,15,16,17
  MBlaze::MULI,  MBlaze::BSRLI,  UNSUPPORTED,    MBlaze::GET,     //18,19,1A,1B
  UNSUPPORTED,   UNSUPPORTED,    UNSUPPORTED,    UNSUPPORTED,     //1C,1D,1E,1F

  MBlaze::OR,    MBlaze::AND,    MBlaze::XOR,    MBlaze::ANDN,    //20,21,22,23
  MBlaze::SEXT8, MBlaze::MFS,    MBlaze::BR,     MBlaze::BEQ,     //24,25,26,27
  MBlaze::ORI,   MBlaze::ANDI,   MBlaze::XORI,   MBlaze::ANDNI,   //28,29,2A,2B
  MBlaze::IMM,   MBlaze::RTSD,   MBlaze::BRI,    MBlaze::BEQI,    //2C,2D,2E,2F

  MBlaze::LBU,   MBlaze::LHU,    MBlaze::LW,     UNSUPPORTED,     //30,31,32,33
  MBlaze::SB,    MBlaze::SH,     MBlaze::SW,     UNSUPPORTED,     //34,35,36,37
  MBlaze::LBUI,  MBlaze::LHUI,   MBlaze::LWI,    UNSUPPORTED,     //38,39,3A,3B
  MBlaze::SBI,   MBlaze::SHI,    MBlaze::SWI,    UNSUPPORTED,     //3C,3D,3E,3F
};

static unsigned getRD(uint32_t insn) {
  if (!isMBlazeRegister((insn>>21)&0x1F))
    return UNSUPPORTED;
  return getMBlazeRegisterFromNumbering((insn>>21)&0x1F);
}

static unsigned getRA(uint32_t insn) {
  if (!getMBlazeRegisterFromNumbering((insn>>16)&0x1F))
    return UNSUPPORTED;
  return getMBlazeRegisterFromNumbering((insn>>16)&0x1F);
}

static unsigned getRB(uint32_t insn) {
  if (!getMBlazeRegisterFromNumbering((insn>>11)&0x1F))
    return UNSUPPORTED;
  return getMBlazeRegisterFromNumbering((insn>>11)&0x1F);
}

static int64_t getRS(uint32_t insn) {
  if (!isSpecialMBlazeRegister(insn&0x3FFF))
    return UNSUPPORTED;
  return getSpecialMBlazeRegisterFromNumbering(insn&0x3FFF);
}

static int64_t getIMM(uint32_t insn) {
    int16_t val = (insn & 0xFFFF);
    return val;
}

static int64_t getSHT(uint32_t insn) {
    int16_t val = (insn & 0x1F);
    return val;
}

static unsigned getFLAGS(int32_t insn) {
    return (insn & 0x7FF);
}

static int64_t getFSL(uint32_t insn) {
    int16_t val = (insn & 0xF);
    return val;
}

static unsigned decodeMUL(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default: return UNSUPPORTED;
    case 0:  return MBlaze::MUL;
    case 1:  return MBlaze::MULH;
    case 2:  return MBlaze::MULHSU;
    case 3:  return MBlaze::MULHU;
    }
}

static unsigned decodeSEXT(uint32_t insn) {
    switch (insn&0x7FF) {
    default:   return UNSUPPORTED;
    case 0x60: return MBlaze::SEXT8;
    case 0x68: return MBlaze::WIC;
    case 0x64: return MBlaze::WDC;
    case 0x66: return MBlaze::WDCC;
    case 0x74: return MBlaze::WDCF;
    case 0x61: return MBlaze::SEXT16;
    case 0x41: return MBlaze::SRL;
    case 0x21: return MBlaze::SRC;
    case 0x01: return MBlaze::SRA;
    case 0xE0: return MBlaze::CLZ;
    }
}

static unsigned decodeBEQ(uint32_t insn) {
    switch ((insn>>21)&0x1F) {
    default:    return UNSUPPORTED;
    case 0x00:  return MBlaze::BEQ;
    case 0x10:  return MBlaze::BEQD;
    case 0x05:  return MBlaze::BGE;
    case 0x15:  return MBlaze::BGED;
    case 0x04:  return MBlaze::BGT;
    case 0x14:  return MBlaze::BGTD;
    case 0x03:  return MBlaze::BLE;
    case 0x13:  return MBlaze::BLED;
    case 0x02:  return MBlaze::BLT;
    case 0x12:  return MBlaze::BLTD;
    case 0x01:  return MBlaze::BNE;
    case 0x11:  return MBlaze::BNED;
    }
}

static unsigned decodeBEQI(uint32_t insn) {
    switch ((insn>>21)&0x1F) {
    default:    return UNSUPPORTED;
    case 0x00:  return MBlaze::BEQI;
    case 0x10:  return MBlaze::BEQID;
    case 0x05:  return MBlaze::BGEI;
    case 0x15:  return MBlaze::BGEID;
    case 0x04:  return MBlaze::BGTI;
    case 0x14:  return MBlaze::BGTID;
    case 0x03:  return MBlaze::BLEI;
    case 0x13:  return MBlaze::BLEID;
    case 0x02:  return MBlaze::BLTI;
    case 0x12:  return MBlaze::BLTID;
    case 0x01:  return MBlaze::BNEI;
    case 0x11:  return MBlaze::BNEID;
    }
}

static unsigned decodeBR(uint32_t insn) {
    switch ((insn>>16)&0x1F) {
    default:   return UNSUPPORTED;
    case 0x00: return MBlaze::BR;
    case 0x08: return MBlaze::BRA;
    case 0x0C: return MBlaze::BRK;
    case 0x10: return MBlaze::BRD;
    case 0x14: return MBlaze::BRLD;
    case 0x18: return MBlaze::BRAD;
    case 0x1C: return MBlaze::BRALD;
    }
}

static unsigned decodeBRI(uint32_t insn) {
    switch (insn&0x3FFFFFF) {
    default:        break;
    case 0x0020004: return MBlaze::IDMEMBAR;
    case 0x0220004: return MBlaze::DMEMBAR;
    case 0x0420004: return MBlaze::IMEMBAR;
    }

    switch ((insn>>16)&0x1F) {
    default:   return UNSUPPORTED;
    case 0x00: return MBlaze::BRI;
    case 0x08: return MBlaze::BRAI;
    case 0x0C: return MBlaze::BRKI;
    case 0x10: return MBlaze::BRID;
    case 0x14: return MBlaze::BRLID;
    case 0x18: return MBlaze::BRAID;
    case 0x1C: return MBlaze::BRALID;
    }
}

static unsigned decodeBSRL(uint32_t insn) {
    switch ((insn>>9)&0x3) {
    default:  return UNSUPPORTED;
    case 0x2: return MBlaze::BSLL;
    case 0x1: return MBlaze::BSRA;
    case 0x0: return MBlaze::BSRL;
    }
}

static unsigned decodeBSRLI(uint32_t insn) {
    switch ((insn>>9)&0x3) {
    default:  return UNSUPPORTED;
    case 0x2: return MBlaze::BSLLI;
    case 0x1: return MBlaze::BSRAI;
    case 0x0: return MBlaze::BSRLI;
    }
}

static unsigned decodeRSUBK(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::RSUBK;
    case 0x1: return MBlaze::CMP;
    case 0x3: return MBlaze::CMPU;
    }
}

static unsigned decodeFADD(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default:    return UNSUPPORTED;
    case 0x000: return MBlaze::FADD;
    case 0x080: return MBlaze::FRSUB;
    case 0x100: return MBlaze::FMUL;
    case 0x180: return MBlaze::FDIV;
    case 0x200: return MBlaze::FCMP_UN;
    case 0x210: return MBlaze::FCMP_LT;
    case 0x220: return MBlaze::FCMP_EQ;
    case 0x230: return MBlaze::FCMP_LE;
    case 0x240: return MBlaze::FCMP_GT;
    case 0x250: return MBlaze::FCMP_NE;
    case 0x260: return MBlaze::FCMP_GE;
    case 0x280: return MBlaze::FLT;
    case 0x300: return MBlaze::FINT;
    case 0x380: return MBlaze::FSQRT;
    }
}

static unsigned decodeGET(uint32_t insn) {
    switch ((insn>>10)&0x3F) {
    default:   return UNSUPPORTED;
    case 0x00: return MBlaze::GET;
    case 0x01: return MBlaze::EGET;
    case 0x02: return MBlaze::AGET;
    case 0x03: return MBlaze::EAGET;
    case 0x04: return MBlaze::TGET;
    case 0x05: return MBlaze::TEGET;
    case 0x06: return MBlaze::TAGET;
    case 0x07: return MBlaze::TEAGET;
    case 0x08: return MBlaze::CGET;
    case 0x09: return MBlaze::ECGET;
    case 0x0A: return MBlaze::CAGET;
    case 0x0B: return MBlaze::ECAGET;
    case 0x0C: return MBlaze::TCGET;
    case 0x0D: return MBlaze::TECGET;
    case 0x0E: return MBlaze::TCAGET;
    case 0x0F: return MBlaze::TECAGET;
    case 0x10: return MBlaze::NGET;
    case 0x11: return MBlaze::NEGET;
    case 0x12: return MBlaze::NAGET;
    case 0x13: return MBlaze::NEAGET;
    case 0x14: return MBlaze::TNGET;
    case 0x15: return MBlaze::TNEGET;
    case 0x16: return MBlaze::TNAGET;
    case 0x17: return MBlaze::TNEAGET;
    case 0x18: return MBlaze::NCGET;
    case 0x19: return MBlaze::NECGET;
    case 0x1A: return MBlaze::NCAGET;
    case 0x1B: return MBlaze::NECAGET;
    case 0x1C: return MBlaze::TNCGET;
    case 0x1D: return MBlaze::TNECGET;
    case 0x1E: return MBlaze::TNCAGET;
    case 0x1F: return MBlaze::TNECAGET;
    case 0x20: return MBlaze::PUT;
    case 0x22: return MBlaze::APUT;
    case 0x24: return MBlaze::TPUT;
    case 0x26: return MBlaze::TAPUT;
    case 0x28: return MBlaze::CPUT;
    case 0x2A: return MBlaze::CAPUT;
    case 0x2C: return MBlaze::TCPUT;
    case 0x2E: return MBlaze::TCAPUT;
    case 0x30: return MBlaze::NPUT;
    case 0x32: return MBlaze::NAPUT;
    case 0x34: return MBlaze::TNPUT;
    case 0x36: return MBlaze::TNAPUT;
    case 0x38: return MBlaze::NCPUT;
    case 0x3A: return MBlaze::NCAPUT;
    case 0x3C: return MBlaze::TNCPUT;
    case 0x3E: return MBlaze::TNCAPUT;
    }
}

static unsigned decodeGETD(uint32_t insn) {
    switch ((insn>>5)&0x3F) {
    default:   return UNSUPPORTED;
    case 0x00: return MBlaze::GETD;
    case 0x01: return MBlaze::EGETD;
    case 0x02: return MBlaze::AGETD;
    case 0x03: return MBlaze::EAGETD;
    case 0x04: return MBlaze::TGETD;
    case 0x05: return MBlaze::TEGETD;
    case 0x06: return MBlaze::TAGETD;
    case 0x07: return MBlaze::TEAGETD;
    case 0x08: return MBlaze::CGETD;
    case 0x09: return MBlaze::ECGETD;
    case 0x0A: return MBlaze::CAGETD;
    case 0x0B: return MBlaze::ECAGETD;
    case 0x0C: return MBlaze::TCGETD;
    case 0x0D: return MBlaze::TECGETD;
    case 0x0E: return MBlaze::TCAGETD;
    case 0x0F: return MBlaze::TECAGETD;
    case 0x10: return MBlaze::NGETD;
    case 0x11: return MBlaze::NEGETD;
    case 0x12: return MBlaze::NAGETD;
    case 0x13: return MBlaze::NEAGETD;
    case 0x14: return MBlaze::TNGETD;
    case 0x15: return MBlaze::TNEGETD;
    case 0x16: return MBlaze::TNAGETD;
    case 0x17: return MBlaze::TNEAGETD;
    case 0x18: return MBlaze::NCGETD;
    case 0x19: return MBlaze::NECGETD;
    case 0x1A: return MBlaze::NCAGETD;
    case 0x1B: return MBlaze::NECAGETD;
    case 0x1C: return MBlaze::TNCGETD;
    case 0x1D: return MBlaze::TNECGETD;
    case 0x1E: return MBlaze::TNCAGETD;
    case 0x1F: return MBlaze::TNECAGETD;
    case 0x20: return MBlaze::PUTD;
    case 0x22: return MBlaze::APUTD;
    case 0x24: return MBlaze::TPUTD;
    case 0x26: return MBlaze::TAPUTD;
    case 0x28: return MBlaze::CPUTD;
    case 0x2A: return MBlaze::CAPUTD;
    case 0x2C: return MBlaze::TCPUTD;
    case 0x2E: return MBlaze::TCAPUTD;
    case 0x30: return MBlaze::NPUTD;
    case 0x32: return MBlaze::NAPUTD;
    case 0x34: return MBlaze::TNPUTD;
    case 0x36: return MBlaze::TNAPUTD;
    case 0x38: return MBlaze::NCPUTD;
    case 0x3A: return MBlaze::NCAPUTD;
    case 0x3C: return MBlaze::TNCPUTD;
    case 0x3E: return MBlaze::TNCAPUTD;
    }
}

static unsigned decodeIDIV(uint32_t insn) {
    switch (insn&0x3) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::IDIV;
    case 0x2: return MBlaze::IDIVU;
    }
}

static unsigned decodeLBU(uint32_t insn) {
    switch ((insn>>9)&0x1) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::LBU;
    case 0x1: return MBlaze::LBUR;
    }
}

static unsigned decodeLHU(uint32_t insn) {
    switch ((insn>>9)&0x1) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::LHU;
    case 0x1: return MBlaze::LHUR;
    }
}

static unsigned decodeLW(uint32_t insn) {
    switch ((insn>>9)&0x3) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::LW;
    case 0x1: return MBlaze::LWR;
    case 0x2: return MBlaze::LWX;
    }
}

static unsigned decodeSB(uint32_t insn) {
    switch ((insn>>9)&0x1) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::SB;
    case 0x1: return MBlaze::SBR;
    }
}

static unsigned decodeSH(uint32_t insn) {
    switch ((insn>>9)&0x1) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::SH;
    case 0x1: return MBlaze::SHR;
    }
}

static unsigned decodeSW(uint32_t insn) {
    switch ((insn>>9)&0x3) {
    default:  return UNSUPPORTED;
    case 0x0: return MBlaze::SW;
    case 0x1: return MBlaze::SWR;
    case 0x2: return MBlaze::SWX;
    }
}

static unsigned decodeMFS(uint32_t insn) {
    switch ((insn>>15)&0x1) {
    default:   return UNSUPPORTED;
    case 0x0:
      switch ((insn>>16)&0x1) {
      default:   return UNSUPPORTED;
      case 0x0: return MBlaze::MSRSET;
      case 0x1: return MBlaze::MSRCLR;
      }
    case 0x1:
      switch ((insn>>14)&0x1) {
      default:   return UNSUPPORTED;
      case 0x0: return MBlaze::MFS;
      case 0x1: return MBlaze::MTS;
      }
    }
}

static unsigned decodeOR(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default:    return UNSUPPORTED;
    case 0x000: return MBlaze::OR;
    case 0x400: return MBlaze::PCMPBF;
    }
}

static unsigned decodeXOR(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default:    return UNSUPPORTED;
    case 0x000: return MBlaze::XOR;
    case 0x400: return MBlaze::PCMPEQ;
    }
}

static unsigned decodeANDN(uint32_t insn) {
    switch (getFLAGS(insn)) {
    default:    return UNSUPPORTED;
    case 0x000: return MBlaze::ANDN;
    case 0x400: return MBlaze::PCMPNE;
    }
}

static unsigned decodeRTSD(uint32_t insn) {
    switch ((insn>>21)&0x1F) {
    default:   return UNSUPPORTED;
    case 0x10: return MBlaze::RTSD;
    case 0x11: return MBlaze::RTID;
    case 0x12: return MBlaze::RTBD;
    case 0x14: return MBlaze::RTED;
    }
}

static unsigned getOPCODE(uint32_t insn) {
  unsigned opcode = mblazeBinary2Opcode[ (insn>>26)&0x3F ];
  switch (opcode) {
  case MBlaze::MUL:     return decodeMUL(insn);
  case MBlaze::SEXT8:   return decodeSEXT(insn);
  case MBlaze::BEQ:     return decodeBEQ(insn);
  case MBlaze::BEQI:    return decodeBEQI(insn);
  case MBlaze::BR:      return decodeBR(insn);
  case MBlaze::BRI:     return decodeBRI(insn);
  case MBlaze::BSRL:    return decodeBSRL(insn);
  case MBlaze::BSRLI:   return decodeBSRLI(insn);
  case MBlaze::RSUBK:   return decodeRSUBK(insn);
  case MBlaze::FADD:    return decodeFADD(insn);
  case MBlaze::GET:     return decodeGET(insn);
  case MBlaze::GETD:    return decodeGETD(insn);
  case MBlaze::IDIV:    return decodeIDIV(insn);
  case MBlaze::LBU:     return decodeLBU(insn);
  case MBlaze::LHU:     return decodeLHU(insn);
  case MBlaze::LW:      return decodeLW(insn);
  case MBlaze::SB:      return decodeSB(insn);
  case MBlaze::SH:      return decodeSH(insn);
  case MBlaze::SW:      return decodeSW(insn);
  case MBlaze::MFS:     return decodeMFS(insn);
  case MBlaze::OR:      return decodeOR(insn);
  case MBlaze::XOR:     return decodeXOR(insn);
  case MBlaze::ANDN:    return decodeANDN(insn);
  case MBlaze::RTSD:    return decodeRTSD(insn);
  default:              return opcode;
  }
}

EDInstInfo *MBlazeDisassembler::getEDInfo() const {
  return instInfoMBlaze;
}

//
// Public interface for the disassembler
//

MCDisassembler::DecodeStatus MBlazeDisassembler::getInstruction(MCInst &instr,
                                        uint64_t &size,
                                        const MemoryObject &region,
                                        uint64_t address,
                                        raw_ostream &vStream,
                                        raw_ostream &cStream) const {
  // The machine instruction.
  uint32_t insn;
  uint64_t read;
  uint8_t bytes[4];

  // By default we consume 1 byte on failure
  size = 1;

  // We want to read exactly 4 bytes of data.
  if (region.readBytes(address, 4, (uint8_t*)bytes, &read) == -1 || read < 4)
    return Fail;

  // Encoded as a big-endian 32-bit word in the stream.
  insn = (bytes[0]<<24) | (bytes[1]<<16) | (bytes[2]<< 8) | (bytes[3]<<0);

  // Get the MCInst opcode from the binary instruction and make sure
  // that it is a valid instruction.
  unsigned opcode = getOPCODE(insn);
  if (opcode == UNSUPPORTED)
    return Fail;

  instr.setOpcode(opcode);

  unsigned RD = getRD(insn);
  unsigned RA = getRA(insn);
  unsigned RB = getRB(insn);
  unsigned RS = getRS(insn);

  uint64_t tsFlags = MBlazeInsts[opcode].TSFlags;
  switch ((tsFlags & MBlazeII::FormMask)) {
  default: 
    return Fail;

  case MBlazeII::FC:
    break;

  case MBlazeII::FRRRR:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED || RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RB));
    instr.addOperand(MCOperand::CreateReg(RA));
    break;

  case MBlazeII::FRRR:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED || RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RA));
    instr.addOperand(MCOperand::CreateReg(RB));
    break;

  case MBlazeII::FRR:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RA));
    break;

  case MBlazeII::FRI:
    switch (opcode) {
    default: 
      return Fail;
    case MBlaze::MFS:
      if (RD == UNSUPPORTED)
        return Fail;
      instr.addOperand(MCOperand::CreateReg(RD));
      instr.addOperand(MCOperand::CreateImm(insn&0x3FFF));
      break;
    case MBlaze::MTS:
      if (RA == UNSUPPORTED)
        return Fail;
      instr.addOperand(MCOperand::CreateImm(insn&0x3FFF));
      instr.addOperand(MCOperand::CreateReg(RA));
      break;
    case MBlaze::MSRSET:
    case MBlaze::MSRCLR:
      if (RD == UNSUPPORTED)
        return Fail;
      instr.addOperand(MCOperand::CreateReg(RD));
      instr.addOperand(MCOperand::CreateImm(insn&0x7FFF));
      break;
    }
    break;

  case MBlazeII::FRRI:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RA));
    switch (opcode) {
    default:
      instr.addOperand(MCOperand::CreateImm(getIMM(insn)));
      break;
    case MBlaze::BSRLI:
    case MBlaze::BSRAI:
    case MBlaze::BSLLI:
      instr.addOperand(MCOperand::CreateImm(insn&0x1F));
      break;
    }
    break;

  case MBlazeII::FCRR:
    if (RA == UNSUPPORTED || RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RA));
    instr.addOperand(MCOperand::CreateReg(RB));
    break;

  case MBlazeII::FCRI:
    if (RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RA));
    instr.addOperand(MCOperand::CreateImm(getIMM(insn)));
    break;

  case MBlazeII::FRCR:
    if (RD == UNSUPPORTED || RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RB));
    break;

  case MBlazeII::FRCI:
    if (RD == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateImm(getIMM(insn)));
    break;

  case MBlazeII::FCCR:
    if (RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RB));
    break;

  case MBlazeII::FCCI:
    instr.addOperand(MCOperand::CreateImm(getIMM(insn)));
    break;

  case MBlazeII::FRRCI:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RA));
    instr.addOperand(MCOperand::CreateImm(getSHT(insn)));
    break;

  case MBlazeII::FRRC:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RA));
    break;

  case MBlazeII::FRCX:
    if (RD == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateImm(getFSL(insn)));
    break;

  case MBlazeII::FRCS:
    if (RD == UNSUPPORTED || RS == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateReg(RS));
    break;

  case MBlazeII::FCRCS:
    if (RS == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RS));
    instr.addOperand(MCOperand::CreateReg(RA));
    break;

  case MBlazeII::FCRCX:
    if (RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RA));
    instr.addOperand(MCOperand::CreateImm(getFSL(insn)));
    break;

  case MBlazeII::FCX:
    instr.addOperand(MCOperand::CreateImm(getFSL(insn)));
    break;

  case MBlazeII::FCR:
    if (RB == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RB));
    break;

  case MBlazeII::FRIR:
    if (RD == UNSUPPORTED || RA == UNSUPPORTED)
      return Fail;
    instr.addOperand(MCOperand::CreateReg(RD));
    instr.addOperand(MCOperand::CreateImm(getIMM(insn)));
    instr.addOperand(MCOperand::CreateReg(RA));
    break;
  }

  // We always consume 4 bytes of data on success
  size = 4;

  return Success;
}

static MCDisassembler *createMBlazeDisassembler(const Target &T,
                                                const MCSubtargetInfo &STI) {
  return new MBlazeDisassembler(STI);
}

extern "C" void LLVMInitializeMBlazeDisassembler() {
  // Register the disassembler.
  TargetRegistry::RegisterMCDisassembler(TheMBlazeTarget,
                                         createMBlazeDisassembler);
}