aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/luajit-2.0/lib/dis_x86.lua
blob: d9a1f32134160bce7dbf783f9d63524351a15eaf (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
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
----------------------------------------------------------------------------
-- LuaJIT x86/x64 disassembler module.
--
-- Copyright (C) 2005-2011 Mike Pall. All rights reserved.
-- Released under the MIT license. See Copyright Notice in luajit.h
----------------------------------------------------------------------------
-- This is a helper module used by the LuaJIT machine code dumper module.
--
-- Sending small code snippets to an external disassembler and mixing the
-- output with our own stuff was too fragile. So I had to bite the bullet
-- and write yet another x86 disassembler. Oh well ...
--
-- The output format is very similar to what ndisasm generates. But it has
-- been developed independently by looking at the opcode tables from the
-- Intel and AMD manuals. The supported instruction set is quite extensive
-- and reflects what a current generation Intel or AMD CPU implements in
-- 32 bit and 64 bit mode. Yes, this includes MMX, SSE, SSE2, SSE3, SSSE3,
-- SSE4.1, SSE4.2, SSE4a and even privileged and hypervisor (VMX/SVM)
-- instructions.
--
-- Notes:
-- * The (useless) a16 prefix, 3DNow and pre-586 opcodes are unsupported.
-- * No attempt at optimization has been made -- it's fast enough for my needs.
-- * The public API may change when more architectures are added.
------------------------------------------------------------------------------

local type = type
local sub, byte, format = string.sub, string.byte, string.format
local match, gmatch, gsub = string.match, string.gmatch, string.gsub
local lower, rep = string.lower, string.rep

-- Map for 1st opcode byte in 32 bit mode. Ugly? Well ... read on.
local map_opc1_32 = {
--0x
[0]="addBmr","addVmr","addBrm","addVrm","addBai","addVai","push es","pop es",
"orBmr","orVmr","orBrm","orVrm","orBai","orVai","push cs","opc2*",
--1x
"adcBmr","adcVmr","adcBrm","adcVrm","adcBai","adcVai","push ss","pop ss",
"sbbBmr","sbbVmr","sbbBrm","sbbVrm","sbbBai","sbbVai","push ds","pop ds",
--2x
"andBmr","andVmr","andBrm","andVrm","andBai","andVai","es:seg","daa",
"subBmr","subVmr","subBrm","subVrm","subBai","subVai","cs:seg","das",
--3x
"xorBmr","xorVmr","xorBrm","xorVrm","xorBai","xorVai","ss:seg","aaa",
"cmpBmr","cmpVmr","cmpBrm","cmpVrm","cmpBai","cmpVai","ds:seg","aas",
--4x
"incVR","incVR","incVR","incVR","incVR","incVR","incVR","incVR",
"decVR","decVR","decVR","decVR","decVR","decVR","decVR","decVR",
--5x
"pushUR","pushUR","pushUR","pushUR","pushUR","pushUR","pushUR","pushUR",
"popUR","popUR","popUR","popUR","popUR","popUR","popUR","popUR",
--6x
"sz*pushaw,pusha","sz*popaw,popa","boundVrm","arplWmr",
"fs:seg","gs:seg","o16:","a16",
"pushUi","imulVrmi","pushBs","imulVrms",
"insb","insVS","outsb","outsVS",
--7x
"joBj","jnoBj","jbBj","jnbBj","jzBj","jnzBj","jbeBj","jaBj",
"jsBj","jnsBj","jpeBj","jpoBj","jlBj","jgeBj","jleBj","jgBj",
--8x
"arith!Bmi","arith!Vmi","arith!Bmi","arith!Vms",
"testBmr","testVmr","xchgBrm","xchgVrm",
"movBmr","movVmr","movBrm","movVrm",
"movVmg","leaVrm","movWgm","popUm",
--9x
"nop*xchgVaR|pause|xchgWaR|repne nop","xchgVaR","xchgVaR","xchgVaR",
"xchgVaR","xchgVaR","xchgVaR","xchgVaR",
"sz*cbw,cwde,cdqe","sz*cwd,cdq,cqo","call farViw","wait",
"sz*pushfw,pushf","sz*popfw,popf","sahf","lahf",
--Ax
"movBao","movVao","movBoa","movVoa",
"movsb","movsVS","cmpsb","cmpsVS",
"testBai","testVai","stosb","stosVS",
"lodsb","lodsVS","scasb","scasVS",
--Bx
"movBRi","movBRi","movBRi","movBRi","movBRi","movBRi","movBRi","movBRi",
"movVRI","movVRI","movVRI","movVRI","movVRI","movVRI","movVRI","movVRI",
--Cx
"shift!Bmu","shift!Vmu","retBw","ret","$lesVrm","$ldsVrm","movBmi","movVmi",
"enterBwu","leave","retfBw","retf","int3","intBu","into","iretVS",
--Dx
"shift!Bm1","shift!Vm1","shift!Bmc","shift!Vmc","aamBu","aadBu","salc","xlatb",
"fp*0","fp*1","fp*2","fp*3","fp*4","fp*5","fp*6","fp*7",
--Ex
"loopneBj","loopeBj","loopBj","sz*jcxzBj,jecxzBj,jrcxzBj",
"inBau","inVau","outBua","outVua",
"callVj","jmpVj","jmp farViw","jmpBj","inBad","inVad","outBda","outVda",
--Fx
"lock:","int1","repne:rep","rep:","hlt","cmc","testb!Bm","testv!Vm",
"clc","stc","cli","sti","cld","std","incb!Bm","incd!Vm",
}
assert(#map_opc1_32 == 255)

-- Map for 1st opcode byte in 64 bit mode (overrides only).
local map_opc1_64 = setmetatable({
  [0x06]=false, [0x07]=false, [0x0e]=false,
  [0x16]=false, [0x17]=false, [0x1e]=false, [0x1f]=false,
  [0x27]=false, [0x2f]=false, [0x37]=false, [0x3f]=false,
  [0x60]=false, [0x61]=false, [0x62]=false, [0x63]="movsxdVrDmt", [0x67]="a32:",
  [0x40]="rex*",   [0x41]="rex*b",   [0x42]="rex*x",   [0x43]="rex*xb",
  [0x44]="rex*r",  [0x45]="rex*rb",  [0x46]="rex*rx",  [0x47]="rex*rxb",
  [0x48]="rex*w",  [0x49]="rex*wb",  [0x4a]="rex*wx",  [0x4b]="rex*wxb",
  [0x4c]="rex*wr", [0x4d]="rex*wrb", [0x4e]="rex*wrx", [0x4f]="rex*wrxb",
  [0x82]=false, [0x9a]=false, [0xc4]=false, [0xc5]=false, [0xce]=false,
  [0xd4]=false, [0xd5]=false, [0xd6]=false, [0xea]=false,
}, { __index = map_opc1_32 })

-- Map for 2nd opcode byte (0F xx). True CISC hell. Hey, I told you.
-- Prefix dependent MMX/SSE opcodes: (none)|rep|o16|repne, -|F3|66|F2
local map_opc2 = {
--0x
[0]="sldt!Dmp","sgdt!Ump","larVrm","lslVrm",nil,"syscall","clts","sysret",
"invd","wbinvd",nil,"ud1",nil,"$prefetch!Bm","femms","3dnowMrmu",
--1x
"movupsXrm|movssXrm|movupdXrm|movsdXrm",
"movupsXmr|movssXmr|movupdXmr|movsdXmr",
"movhlpsXrm$movlpsXrm|movsldupXrm|movlpdXrm|movddupXrm",
"movlpsXmr||movlpdXmr",
"unpcklpsXrm||unpcklpdXrm",
"unpckhpsXrm||unpckhpdXrm",
"movlhpsXrm$movhpsXrm|movshdupXrm|movhpdXrm",
"movhpsXmr||movhpdXmr",
"$prefetcht!Bm","hintnopVm","hintnopVm","hintnopVm",
"hintnopVm","hintnopVm","hintnopVm","hintnopVm",
--2x
"movUmx$","movUmy$","movUxm$","movUym$","movUmz$",nil,"movUzm$",nil,
"movapsXrm||movapdXrm",
"movapsXmr||movapdXmr",
"cvtpi2psXrMm|cvtsi2ssXrVmt|cvtpi2pdXrMm|cvtsi2sdXrVmt",
"movntpsXmr|movntssXmr|movntpdXmr|movntsdXmr",
"cvttps2piMrXm|cvttss2siVrXm|cvttpd2piMrXm|cvttsd2siVrXm",
"cvtps2piMrXm|cvtss2siVrXm|cvtpd2piMrXm|cvtsd2siVrXm",
"ucomissXrm||ucomisdXrm",
"comissXrm||comisdXrm",
--3x
"wrmsr","rdtsc","rdmsr","rdpmc","sysenter","sysexit",nil,"getsec",
"opc3*38",nil,"opc3*3a",nil,nil,nil,nil,nil,
--4x
"cmovoVrm","cmovnoVrm","cmovbVrm","cmovnbVrm",
"cmovzVrm","cmovnzVrm","cmovbeVrm","cmovaVrm",
"cmovsVrm","cmovnsVrm","cmovpeVrm","cmovpoVrm",
"cmovlVrm","cmovgeVrm","cmovleVrm","cmovgVrm",
--5x
"movmskpsVrXm$||movmskpdVrXm$","sqrtpsXrm|sqrtssXrm|sqrtpdXrm|sqrtsdXrm",
"rsqrtpsXrm|rsqrtssXrm","rcppsXrm|rcpssXrm",
"andpsXrm||andpdXrm","andnpsXrm||andnpdXrm",
"orpsXrm||orpdXrm","xorpsXrm||xorpdXrm",
"addpsXrm|addssXrm|addpdXrm|addsdXrm","mulpsXrm|mulssXrm|mulpdXrm|mulsdXrm",
"cvtps2pdXrm|cvtss2sdXrm|cvtpd2psXrm|cvtsd2ssXrm",
"cvtdq2psXrm|cvttps2dqXrm|cvtps2dqXrm",
"subpsXrm|subssXrm|subpdXrm|subsdXrm","minpsXrm|minssXrm|minpdXrm|minsdXrm",
"divpsXrm|divssXrm|divpdXrm|divsdXrm","maxpsXrm|maxssXrm|maxpdXrm|maxsdXrm",
--6x
"punpcklbwPrm","punpcklwdPrm","punpckldqPrm","packsswbPrm",
"pcmpgtbPrm","pcmpgtwPrm","pcmpgtdPrm","packuswbPrm",
"punpckhbwPrm","punpckhwdPrm","punpckhdqPrm","packssdwPrm",
"||punpcklqdqXrm","||punpckhqdqXrm",
"movPrVSm","movqMrm|movdquXrm|movdqaXrm",
--7x
"pshufwMrmu|pshufhwXrmu|pshufdXrmu|pshuflwXrmu","pshiftw!Pmu",
"pshiftd!Pmu","pshiftq!Mmu||pshiftdq!Xmu",
"pcmpeqbPrm","pcmpeqwPrm","pcmpeqdPrm","emms|",
"vmreadUmr||extrqXmuu$|insertqXrmuu$","vmwriteUrm||extrqXrm$|insertqXrm$",
nil,nil,
"||haddpdXrm|haddpsXrm","||hsubpdXrm|hsubpsXrm",
"movVSmMr|movqXrm|movVSmXr","movqMmr|movdquXmr|movdqaXmr",
--8x
"joVj","jnoVj","jbVj","jnbVj","jzVj","jnzVj","jbeVj","jaVj",
"jsVj","jnsVj","jpeVj","jpoVj","jlVj","jgeVj","jleVj","jgVj",
--9x
"setoBm","setnoBm","setbBm","setnbBm","setzBm","setnzBm","setbeBm","setaBm",
"setsBm","setnsBm","setpeBm","setpoBm","setlBm","setgeBm","setleBm","setgBm",
--Ax
"push fs","pop fs","cpuid","btVmr","shldVmru","shldVmrc",nil,nil,
"push gs","pop gs","rsm","btsVmr","shrdVmru","shrdVmrc","fxsave!Dmp","imulVrm",
--Bx
"cmpxchgBmr","cmpxchgVmr","$lssVrm","btrVmr",
"$lfsVrm","$lgsVrm","movzxVrBmt","movzxVrWmt",
"|popcntVrm","ud2Dp","bt!Vmu","btcVmr",
"bsfVrm","bsrVrm|lzcntVrm|bsrWrm","movsxVrBmt","movsxVrWmt",
--Cx
"xaddBmr","xaddVmr",
"cmppsXrmu|cmpssXrmu|cmppdXrmu|cmpsdXrmu","$movntiVmr|",
"pinsrwPrWmu","pextrwDrPmu",
"shufpsXrmu||shufpdXrmu","$cmpxchg!Qmp",
"bswapVR","bswapVR","bswapVR","bswapVR","bswapVR","bswapVR","bswapVR","bswapVR",
--Dx
"||addsubpdXrm|addsubpsXrm","psrlwPrm","psrldPrm","psrlqPrm",
"paddqPrm","pmullwPrm",
"|movq2dqXrMm|movqXmr|movdq2qMrXm$","pmovmskbVrMm||pmovmskbVrXm",
"psubusbPrm","psubuswPrm","pminubPrm","pandPrm",
"paddusbPrm","padduswPrm","pmaxubPrm","pandnPrm",
--Ex
"pavgbPrm","psrawPrm","psradPrm","pavgwPrm",
"pmulhuwPrm","pmulhwPrm",
"|cvtdq2pdXrm|cvttpd2dqXrm|cvtpd2dqXrm","$movntqMmr||$movntdqXmr",
"psubsbPrm","psubswPrm","pminswPrm","porPrm",
"paddsbPrm","paddswPrm","pmaxswPrm","pxorPrm",
--Fx
"|||lddquXrm","psllwPrm","pslldPrm","psllqPrm",
"pmuludqPrm","pmaddwdPrm","psadbwPrm","maskmovqMrm||maskmovdquXrm$",
"psubbPrm","psubwPrm","psubdPrm","psubqPrm",
"paddbPrm","paddwPrm","padddPrm","ud",
}
assert(map_opc2[255] == "ud")

-- Map for three-byte opcodes. Can't wait for their next invention.
local map_opc3 = {
["38"] = { -- [66] 0f 38 xx
--0x
[0]="pshufbPrm","phaddwPrm","phadddPrm","phaddswPrm",
"pmaddubswPrm","phsubwPrm","phsubdPrm","phsubswPrm",
"psignbPrm","psignwPrm","psigndPrm","pmulhrswPrm",
nil,nil,nil,nil,
--1x
"||pblendvbXrma",nil,nil,nil,
"||blendvpsXrma","||blendvpdXrma",nil,"||ptestXrm",
nil,nil,nil,nil,
"pabsbPrm","pabswPrm","pabsdPrm",nil,
--2x
"||pmovsxbwXrm","||pmovsxbdXrm","||pmovsxbqXrm","||pmovsxwdXrm",
"||pmovsxwqXrm","||pmovsxdqXrm",nil,nil,
"||pmuldqXrm","||pcmpeqqXrm","||$movntdqaXrm","||packusdwXrm",
nil,nil,nil,nil,
--3x
"||pmovzxbwXrm","||pmovzxbdXrm","||pmovzxbqXrm","||pmovzxwdXrm",
"||pmovzxwqXrm","||pmovzxdqXrm",nil,"||pcmpgtqXrm",
"||pminsbXrm","||pminsdXrm","||pminuwXrm","||pminudXrm",
"||pmaxsbXrm","||pmaxsdXrm","||pmaxuwXrm","||pmaxudXrm",
--4x
"||pmulddXrm","||phminposuwXrm",
--Fx
[0xf0] = "|||crc32TrBmt",[0xf1] = "|||crc32TrVmt",
},

["3a"] = { -- [66] 0f 3a xx
--0x
[0x00]=nil,nil,nil,nil,nil,nil,nil,nil,
"||roundpsXrmu","||roundpdXrmu","||roundssXrmu","||roundsdXrmu",
"||blendpsXrmu","||blendpdXrmu","||pblendwXrmu","palignrPrmu",
--1x
nil,nil,nil,nil,
"||pextrbVmXru","||pextrwVmXru","||pextrVmSXru","||extractpsVmXru",
nil,nil,nil,nil,nil,nil,nil,nil,
--2x
"||pinsrbXrVmu","||insertpsXrmu","||pinsrXrVmuS",nil,
--4x
[0x40] = "||dppsXrmu",
[0x41] = "||dppdXrmu",
[0x42] = "||mpsadbwXrmu",
--6x
[0x60] = "||pcmpestrmXrmu",[0x61] = "||pcmpestriXrmu",
[0x62] = "||pcmpistrmXrmu",[0x63] = "||pcmpistriXrmu",
},
}

-- Map for VMX/SVM opcodes 0F 01 C0-FF (sgdt group with register operands).
local map_opcvm = {
[0xc1]="vmcall",[0xc2]="vmlaunch",[0xc3]="vmresume",[0xc4]="vmxoff",
[0xc8]="monitor",[0xc9]="mwait",
[0xd8]="vmrun",[0xd9]="vmmcall",[0xda]="vmload",[0xdb]="vmsave",
[0xdc]="stgi",[0xdd]="clgi",[0xde]="skinit",[0xdf]="invlpga",
[0xf8]="swapgs",[0xf9]="rdtscp",
}

-- Map for FP opcodes. And you thought stack machines are simple?
local map_opcfp = {
-- D8-DF 00-BF: opcodes with a memory operand.
-- D8
[0]="faddFm","fmulFm","fcomFm","fcompFm","fsubFm","fsubrFm","fdivFm","fdivrFm",
"fldFm",nil,"fstFm","fstpFm","fldenvVm","fldcwWm","fnstenvVm","fnstcwWm",
-- DA
"fiaddDm","fimulDm","ficomDm","ficompDm",
"fisubDm","fisubrDm","fidivDm","fidivrDm",
-- DB
"fildDm","fisttpDm","fistDm","fistpDm",nil,"fld twordFmp",nil,"fstp twordFmp",
-- DC
"faddGm","fmulGm","fcomGm","fcompGm","fsubGm","fsubrGm","fdivGm","fdivrGm",
-- DD
"fldGm","fisttpQm","fstGm","fstpGm","frstorDmp",nil,"fnsaveDmp","fnstswWm",
-- DE
"fiaddWm","fimulWm","ficomWm","ficompWm",
"fisubWm","fisubrWm","fidivWm","fidivrWm",
-- DF
"fildWm","fisttpWm","fistWm","fistpWm",
"fbld twordFmp","fildQm","fbstp twordFmp","fistpQm",
-- xx C0-FF: opcodes with a pseudo-register operand.
-- D8
"faddFf","fmulFf","fcomFf","fcompFf","fsubFf","fsubrFf","fdivFf","fdivrFf",
-- D9
"fldFf","fxchFf",{"fnop"},nil,
{"fchs","fabs",nil,nil,"ftst","fxam"},
{"fld1","fldl2t","fldl2e","fldpi","fldlg2","fldln2","fldz"},
{"f2xm1","fyl2x","fptan","fpatan","fxtract","fprem1","fdecstp","fincstp"},
{"fprem","fyl2xp1","fsqrt","fsincos","frndint","fscale","fsin","fcos"},
-- DA
"fcmovbFf","fcmoveFf","fcmovbeFf","fcmovuFf",nil,{nil,"fucompp"},nil,nil,
-- DB
"fcmovnbFf","fcmovneFf","fcmovnbeFf","fcmovnuFf",
{nil,nil,"fnclex","fninit"},"fucomiFf","fcomiFf",nil,
-- DC
"fadd toFf","fmul toFf",nil,nil,
"fsub toFf","fsubr toFf","fdivr toFf","fdiv toFf",
-- DD
"ffreeFf",nil,"fstFf","fstpFf","fucomFf","fucompFf",nil,nil,
-- DE
"faddpFf","fmulpFf",nil,{nil,"fcompp"},
"fsubrpFf","fsubpFf","fdivrpFf","fdivpFf",
-- DF
nil,nil,nil,nil,{"fnstsw ax"},"fucomipFf","fcomipFf",nil,
}
assert(map_opcfp[126] == "fcomipFf")

-- Map for opcode groups. The subkey is sp from the ModRM byte.
local map_opcgroup = {
  arith = { "add", "or", "adc", "sbb", "and", "sub", "xor", "cmp" },
  shift = { "rol", "ror", "rcl", "rcr", "shl", "shr", "sal", "sar" },
  testb = { "testBmi", "testBmi", "not", "neg", "mul", "imul", "div", "idiv" },
  testv = { "testVmi", "testVmi", "not", "neg", "mul", "imul", "div", "idiv" },
  incb = { "inc", "dec" },
  incd = { "inc", "dec", "callUmp", "$call farDmp",
	   "jmpUmp", "$jmp farDmp", "pushUm" },
  sldt = { "sldt", "str", "lldt", "ltr", "verr", "verw" },
  sgdt = { "vm*$sgdt", "vm*$sidt", "$lgdt", "vm*$lidt",
	   "smsw", nil, "lmsw", "vm*$invlpg" },
  bt = { nil, nil, nil, nil, "bt", "bts", "btr", "btc" },
  cmpxchg = { nil, "sz*,cmpxchg8bQmp,cmpxchg16bXmp", nil, nil,
	      nil, nil, "vmptrld|vmxon|vmclear", "vmptrst" },
  pshiftw = { nil, nil, "psrlw", nil, "psraw", nil, "psllw" },
  pshiftd = { nil, nil, "psrld", nil, "psrad", nil, "pslld" },
  pshiftq = { nil, nil, "psrlq", nil, nil, nil, "psllq" },
  pshiftdq = { nil, nil, "psrlq", "psrldq", nil, nil, "psllq", "pslldq" },
  fxsave = { "$fxsave", "$fxrstor", "$ldmxcsr", "$stmxcsr",
	     nil, "lfenceDp$", "mfenceDp$", "sfenceDp$clflush" },
  prefetch = { "prefetch", "prefetchw" },
  prefetcht = { "prefetchnta", "prefetcht0", "prefetcht1", "prefetcht2" },
}

------------------------------------------------------------------------------

-- Maps for register names.
local map_regs = {
  B = { "al", "cl", "dl", "bl", "ah", "ch", "dh", "bh",
	"r8b", "r9b", "r10b", "r11b", "r12b", "r13b", "r14b", "r15b" },
  B64 = { "al", "cl", "dl", "bl", "spl", "bpl", "sil", "dil",
	  "r8b", "r9b", "r10b", "r11b", "r12b", "r13b", "r14b", "r15b" },
  W = { "ax", "cx", "dx", "bx", "sp", "bp", "si", "di",
	"r8w", "r9w", "r10w", "r11w", "r12w", "r13w", "r14w", "r15w" },
  D = { "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi",
	"r8d", "r9d", "r10d", "r11d", "r12d", "r13d", "r14d", "r15d" },
  Q = { "rax", "rcx", "rdx", "rbx", "rsp", "rbp", "rsi", "rdi",
	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15" },
  M = { "mm0", "mm1", "mm2", "mm3", "mm4", "mm5", "mm6", "mm7",
	"mm0", "mm1", "mm2", "mm3", "mm4", "mm5", "mm6", "mm7" }, -- No x64 ext!
  X = { "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7",
	"xmm8", "xmm9", "xmm10", "xmm11", "xmm12", "xmm13", "xmm14", "xmm15" },
}
local map_segregs = { "es", "cs", "ss", "ds", "fs", "gs", "segr6", "segr7" }

-- Maps for size names.
local map_sz2n = {
  B = 1, W = 2, D = 4, Q = 8, M = 8, X = 16,
}
local map_sz2prefix = {
  B = "byte", W = "word", D = "dword",
  Q = "qword",
  M = "qword", X = "xword",
  F = "dword", G = "qword", -- No need for sizes/register names for these two.
}

------------------------------------------------------------------------------

-- Output a nicely formatted line with an opcode and operands.
local function putop(ctx, text, operands)
  local code, pos, hex = ctx.code, ctx.pos, ""
  local hmax = ctx.hexdump
  if hmax > 0 then
    for i=ctx.start,pos-1 do
      hex = hex..format("%02X", byte(code, i, i))
    end
    if #hex > hmax then hex = sub(hex, 1, hmax)..". "
    else hex = hex..rep(" ", hmax-#hex+2) end
  end
  if operands then text = text.." "..operands end
  if ctx.o16 then text = "o16 "..text; ctx.o16 = false end
  if ctx.a32 then text = "a32 "..text; ctx.a32 = false end
  if ctx.rep then text = ctx.rep.." "..text; ctx.rep = false end
  if ctx.rex then
    local t = (ctx.rexw and "w" or "")..(ctx.rexr and "r" or "")..
	      (ctx.rexx and "x" or "")..(ctx.rexb and "b" or "")
    if t ~= "" then text = "rex."..t.." "..text end
    ctx.rexw = false; ctx.rexr = false; ctx.rexx = false; ctx.rexb = false
    ctx.rex = false
  end
  if ctx.seg then
    local text2, n = gsub(text, "%[", "["..ctx.seg..":")
    if n == 0 then text = ctx.seg.." "..text else text = text2 end
    ctx.seg = false
  end
  if ctx.lock then text = "lock "..text; ctx.lock = false end
  local imm = ctx.imm
  if imm then
    local sym = ctx.symtab[imm]
    if sym then text = text.."\t->"..sym end
  end
  ctx.out(format("%08x  %s%s\n", ctx.addr+ctx.start, hex, text))
  ctx.mrm = false
  ctx.start = pos
  ctx.imm = nil
end

-- Clear all prefix flags.
local function clearprefixes(ctx)
  ctx.o16 = false; ctx.seg = false; ctx.lock = false; ctx.rep = false
  ctx.rexw = false; ctx.rexr = false; ctx.rexx = false; ctx.rexb = false
  ctx.rex = false; ctx.a32 = false
end

-- Fallback for incomplete opcodes at the end.
local function incomplete(ctx)
  ctx.pos = ctx.stop+1
  clearprefixes(ctx)
  return putop(ctx, "(incomplete)")
end

-- Fallback for unknown opcodes.
local function unknown(ctx)
  clearprefixes(ctx)
  return putop(ctx, "(unknown)")
end

-- Return an immediate of the specified size.
local function getimm(ctx, pos, n)
  if pos+n-1 > ctx.stop then return incomplete(ctx) end
  local code = ctx.code
  if n == 1 then
    local b1 = byte(code, pos, pos)
    return b1
  elseif n == 2 then
    local b1, b2 = byte(code, pos, pos+1)
    return b1+b2*256
  else
    local b1, b2, b3, b4 = byte(code, pos, pos+3)
    local imm = b1+b2*256+b3*65536+b4*16777216
    ctx.imm = imm
    return imm
  end
end

-- Process pattern string and generate the operands.
local function putpat(ctx, name, pat)
  local operands, regs, sz, mode, sp, rm, sc, rx, sdisp
  local code, pos, stop = ctx.code, ctx.pos, ctx.stop

  -- Chars used: 1DFGIMPQRSTUVWXacdfgijmoprstuwxyz
  for p in gmatch(pat, ".") do
    local x = nil
    if p == "V" or p == "U" then
      if ctx.rexw then sz = "Q"; ctx.rexw = false
      elseif ctx.o16 then sz = "W"; ctx.o16 = false
      elseif p == "U" and ctx.x64 then sz = "Q"
      else sz = "D" end
      regs = map_regs[sz]
    elseif p == "T" then
      if ctx.rexw then sz = "Q"; ctx.rexw = false else sz = "D" end
      regs = map_regs[sz]
    elseif p == "B" then
      sz = "B"
      regs = ctx.rex and map_regs.B64 or map_regs.B
    elseif match(p, "[WDQMXFG]") then
      sz = p
      regs = map_regs[sz]
    elseif p == "P" then
      sz = ctx.o16 and "X" or "M"; ctx.o16 = false
      regs = map_regs[sz]
    elseif p == "S" then
      name = name..lower(sz)
    elseif p == "s" then
      local imm = getimm(ctx, pos, 1); if not imm then return end
      x = imm <= 127 and format("+0x%02x", imm)
		     or format("-0x%02x", 256-imm)
      pos = pos+1
    elseif p == "u" then
      local imm = getimm(ctx, pos, 1); if not imm then return end
      x = format("0x%02x", imm)
      pos = pos+1
    elseif p == "w" then
      local imm = getimm(ctx, pos, 2); if not imm then return end
      x = format("0x%x", imm)
      pos = pos+2
    elseif p == "o" then -- [offset]
      if ctx.x64 then
	local imm1 = getimm(ctx, pos, 4); if not imm1 then return end
	local imm2 = getimm(ctx, pos+4, 4); if not imm2 then return end
	x = format("[0x%08x%08x]", imm2, imm1)
	pos = pos+8
      else
	local imm = getimm(ctx, pos, 4); if not imm then return end
	x = format("[0x%08x]", imm)
	pos = pos+4
      end
    elseif p == "i" or p == "I" then
      local n = map_sz2n[sz]
      if n == 8 and ctx.x64 and p == "I" then
	local imm1 = getimm(ctx, pos, 4); if not imm1 then return end
	local imm2 = getimm(ctx, pos+4, 4); if not imm2 then return end
	x = format("0x%08x%08x", imm2, imm1)
      else
	if n == 8 then n = 4 end
	local imm = getimm(ctx, pos, n); if not imm then return end
	if sz == "Q" and (imm < 0 or imm > 0x7fffffff) then
	  imm = (0xffffffff+1)-imm
	  x = format(imm > 65535 and "-0x%08x" or "-0x%x", imm)
	else
	  x = format(imm > 65535 and "0x%08x" or "0x%x", imm)
	end
      end
      pos = pos+n
    elseif p == "j" then
      local n = map_sz2n[sz]
      if n == 8 then n = 4 end
      local imm = getimm(ctx, pos, n); if not imm then return end
      if sz == "B" and imm > 127 then imm = imm-256
      elseif imm > 2147483647 then imm = imm-4294967296 end
      pos = pos+n
      imm = imm + pos + ctx.addr
      if imm > 4294967295 and not ctx.x64 then imm = imm-4294967296 end
      ctx.imm = imm
      if sz == "W" then
	x = format("word 0x%04x", imm%65536)
      elseif ctx.x64 then
	local lo = imm % 0x1000000
	x = format("0x%02x%06x", (imm-lo) / 0x1000000, lo)
      else
	x = format("0x%08x", imm)
      end
    elseif p == "R" then
      local r = byte(code, pos-1, pos-1)%8
      if ctx.rexb then r = r + 8; ctx.rexb = false end
      x = regs[r+1]
    elseif p == "a" then x = regs[1]
    elseif p == "c" then x = "cl"
    elseif p == "d" then x = "dx"
    elseif p == "1" then x = "1"
    else
      if not mode then
	mode = ctx.mrm
	if not mode then
	  if pos > stop then return incomplete(ctx) end
	  mode = byte(code, pos, pos)
	  pos = pos+1
	end
	rm = mode%8; mode = (mode-rm)/8
	sp = mode%8; mode = (mode-sp)/8
	sdisp = ""
	if mode < 3 then
	  if rm == 4 then
	    if pos > stop then return incomplete(ctx) end
	    sc = byte(code, pos, pos)
	    pos = pos+1
	    rm = sc%8; sc = (sc-rm)/8
	    rx = sc%8; sc = (sc-rx)/8
	    if ctx.rexx then rx = rx + 8; ctx.rexx = false end
	    if rx == 4 then rx = nil end
	  end
	  if mode > 0 or rm == 5 then
	    local dsz = mode
	    if dsz ~= 1 then dsz = 4 end
	    local disp = getimm(ctx, pos, dsz); if not disp then return end
	    if mode == 0 then rm = nil end
	    if rm or rx or (not sc and ctx.x64 and not ctx.a32) then
	      if dsz == 1 and disp > 127 then
		sdisp = format("-0x%x", 256-disp)
	      elseif disp >= 0 and disp <= 0x7fffffff then
		sdisp = format("+0x%x", disp)
	      else
		sdisp = format("-0x%x", (0xffffffff+1)-disp)
	      end
	    else
	      sdisp = format(ctx.x64 and not ctx.a32 and
		not (disp >= 0 and disp <= 0x7fffffff)
		and "0xffffffff%08x" or "0x%08x", disp)
	    end
	    pos = pos+dsz
	  end
	end
	if rm and ctx.rexb then rm = rm + 8; ctx.rexb = false end
	if ctx.rexr then sp = sp + 8; ctx.rexr = false end
      end
      if p == "m" then
	if mode == 3 then x = regs[rm+1]
	else
	  local aregs = ctx.a32 and map_regs.D or ctx.aregs
	  local srm, srx = "", ""
	  if rm then srm = aregs[rm+1]
	  elseif not sc and ctx.x64 and not ctx.a32 then srm = "rip" end
	  ctx.a32 = false
	  if rx then
	    if rm then srm = srm.."+" end
	    srx = aregs[rx+1]
	    if sc > 0 then srx = srx.."*"..(2^sc) end
	  end
	  x = format("[%s%s%s]", srm, srx, sdisp)
	end
	if mode < 3 and
	   (not match(pat, "[aRrgp]") or match(pat, "t")) then -- Yuck.
	  x = map_sz2prefix[sz].." "..x
	end
      elseif p == "r" then x = regs[sp+1]
      elseif p == "g" then x = map_segregs[sp+1]
      elseif p == "p" then -- Suppress prefix.
      elseif p == "f" then x = "st"..rm
      elseif p == "x" then
	if sp == 0 and ctx.lock and not ctx.x64 then
	  x = "CR8"; ctx.lock = false
	else
	  x = "CR"..sp
	end
      elseif p == "y" then x = "DR"..sp
      elseif p == "z" then x = "TR"..sp
      elseif p == "t" then
      else
	error("bad pattern `"..pat.."'")
      end
    end
    if x then operands = operands and operands..", "..x or x end
  end
  ctx.pos = pos
  return putop(ctx, name, operands)
end

-- Forward declaration.
local map_act

-- Fetch and cache MRM byte.
local function getmrm(ctx)
  local mrm = ctx.mrm
  if not mrm then
    local pos = ctx.pos
    if pos > ctx.stop then return nil end
    mrm = byte(ctx.code, pos, pos)
    ctx.pos = pos+1
    ctx.mrm = mrm
  end
  return mrm
end

-- Dispatch to handler depending on pattern.
local function dispatch(ctx, opat, patgrp)
  if not opat then return unknown(ctx) end
  if match(opat, "%|") then -- MMX/SSE variants depending on prefix.
    local p
    if ctx.rep then
      p = ctx.rep=="rep" and "%|([^%|]*)" or "%|[^%|]*%|[^%|]*%|([^%|]*)"
      ctx.rep = false
    elseif ctx.o16 then p = "%|[^%|]*%|([^%|]*)"; ctx.o16 = false
    else p = "^[^%|]*" end
    opat = match(opat, p)
    if not opat then return unknown(ctx) end
--    ctx.rep = false; ctx.o16 = false
    --XXX fails for 66 f2 0f 38 f1 06  crc32 eax,WORD PTR [esi]
    --XXX remove in branches?
  end
  if match(opat, "%$") then -- reg$mem variants.
    local mrm = getmrm(ctx); if not mrm then return incomplete(ctx) end
    opat = match(opat, mrm >= 192 and "^[^%$]*" or "%$(.*)")
    if opat == "" then return unknown(ctx) end
  end
  if opat == "" then return unknown(ctx) end
  local name, pat = match(opat, "^([a-z0-9 ]*)(.*)")
  if pat == "" and patgrp then pat = patgrp end
  return map_act[sub(pat, 1, 1)](ctx, name, pat)
end

-- Get a pattern from an opcode map and dispatch to handler.
local function dispatchmap(ctx, opcmap)
  local pos = ctx.pos
  local opat = opcmap[byte(ctx.code, pos, pos)]
  pos = pos + 1
  ctx.pos = pos
  return dispatch(ctx, opat)
end

-- Map for action codes. The key is the first char after the name.
map_act = {
  -- Simple opcodes without operands.
  [""] = function(ctx, name, pat)
    return putop(ctx, name)
  end,

  -- Operand size chars fall right through.
  B = putpat, W = putpat, D = putpat, Q = putpat,
  V = putpat, U = putpat, T = putpat,
  M = putpat, X = putpat, P = putpat,
  F = putpat, G = putpat,

  -- Collect prefixes.
  [":"] = function(ctx, name, pat)
    ctx[pat == ":" and name or sub(pat, 2)] = name
    if ctx.pos - ctx.start > 5 then return unknown(ctx) end -- Limit #prefixes.
  end,

  -- Chain to special handler specified by name.
  ["*"] = function(ctx, name, pat)
    return map_act[name](ctx, name, sub(pat, 2))
  end,

  -- Use named subtable for opcode group.
  ["!"] = function(ctx, name, pat)
    local mrm = getmrm(ctx); if not mrm then return incomplete(ctx) end
    return dispatch(ctx, map_opcgroup[name][((mrm-(mrm%8))/8)%8+1], sub(pat, 2))
  end,

  -- o16,o32[,o64] variants.
  sz = function(ctx, name, pat)
    if ctx.o16 then ctx.o16 = false
    else
      pat = match(pat, ",(.*)")
      if ctx.rexw then
	local p = match(pat, ",(.*)")
	if p then pat = p; ctx.rexw = false end
      end
    end
    pat = match(pat, "^[^,]*")
    return dispatch(ctx, pat)
  end,

  -- Two-byte opcode dispatch.
  opc2 = function(ctx, name, pat)
    return dispatchmap(ctx, map_opc2)
  end,

  -- Three-byte opcode dispatch.
  opc3 = function(ctx, name, pat)
    return dispatchmap(ctx, map_opc3[pat])
  end,

  -- VMX/SVM dispatch.
  vm = function(ctx, name, pat)
    return dispatch(ctx, map_opcvm[ctx.mrm])
  end,

  -- Floating point opcode dispatch.
  fp = function(ctx, name, pat)
    local mrm = getmrm(ctx); if not mrm then return incomplete(ctx) end
    local rm = mrm%8
    local idx = pat*8 + ((mrm-rm)/8)%8
    if mrm >= 192 then idx = idx + 64 end
    local opat = map_opcfp[idx]
    if type(opat) == "table" then opat = opat[rm+1] end
    return dispatch(ctx, opat)
  end,

  -- REX prefix.
  rex = function(ctx, name, pat)
    if ctx.rex then return unknown(ctx) end -- Only 1 REX prefix allowed.
    for p in gmatch(pat, ".") do ctx["rex"..p] = true end
    ctx.rex = true
  end,

  -- Special case for nop with REX prefix.
  nop = function(ctx, name, pat)
    return dispatch(ctx, ctx.rex and pat or "nop")
  end,
}

------------------------------------------------------------------------------

-- Disassemble a block of code.
local function disass_block(ctx, ofs, len)
  if not ofs then ofs = 0 end
  local stop = len and ofs+len or #ctx.code
  ofs = ofs + 1
  ctx.start = ofs
  ctx.pos = ofs
  ctx.stop = stop
  ctx.imm = nil
  ctx.mrm = false
  clearprefixes(ctx)
  while ctx.pos <= stop do dispatchmap(ctx, ctx.map1) end
  if ctx.pos ~= ctx.start then incomplete(ctx) end
end

-- Extended API: create a disassembler context. Then call ctx:disass(ofs, len).
local function create_(code, addr, out)
  local ctx = {}
  ctx.code = code
  ctx.addr = (addr or 0) - 1
  ctx.out = out or io.write
  ctx.symtab = {}
  ctx.disass = disass_block
  ctx.hexdump = 16
  ctx.x64 = false
  ctx.map1 = map_opc1_32
  ctx.aregs = map_regs.D
  return ctx
end

local function create64_(code, addr, out)
  local ctx = create_(code, addr, out)
  ctx.x64 = true
  ctx.map1 = map_opc1_64
  ctx.aregs = map_regs.Q
  return ctx
end

-- Simple API: disassemble code (a string) at address and output via out.
local function disass_(code, addr, out)
  create_(code, addr, out):disass()
end

local function disass64_(code, addr, out)
  create64_(code, addr, out):disass()
end

-- Return register name for RID.
local function regname_(r)
  if r < 8 then return map_regs.D[r+1] end
  return map_regs.X[r-7]
end

local function regname64_(r)
  if r < 16 then return map_regs.Q[r+1] end
  return map_regs.X[r-15]
end

-- Public module functions.
module(...)

create = create_
create64 = create64_
disass = disass_
disass64 = disass64_
regname = regname_
regname64 = regname64_