about summary refs log tree commit diff stats
path: root/subx/014indirect_addressing.cc
blob: 3767c46d3dab5a064af3f1515af6485a7612e2be (plain) (blame)
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
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//: operating on memory at the address provided by some register
//: we'll now start providing data in a separate segment

void test_add_r32_to_mem_at_r32() {
  Reg[EBX].i = 0x10;
  Reg[EAX].i = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     18                                    \n"  // add EBX to *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x00000011\n"
  );
}

:(before "End Mod Special-cases(addr)")
case 0:  // indirect addressing
  switch (rm) {
  default:  // address in register
    trace(Callstack_depth+1, "run") << "effective address is 0x" << HEXWORD << Reg[rm].u << " (" << rname(rm) << ")" << end();
    addr = Reg[rm].u;
    break;
  // End Mod 0 Special-cases(addr)
  }
  break;

//:

:(before "End Initialize Op Names")
put_new(Name, "03", "add rm32 to r32 (add)");

:(code)
void test_add_mem_at_r32_to_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x10;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  03     18                                    \n"  // add *EAX to EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add r/m32 to EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x00000011\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x03: {  // add r/m32 to r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "add r/m32 to " << rname(arg1) << end();
  const int32_t* signed_arg2 = effective_address(modrm);
  int32_t signed_result = Reg[arg1].i + *signed_arg2;
  SF = (signed_result < 0);
  ZF = (signed_result == 0);
  int64_t signed_full_result = static_cast<int64_t>(Reg[arg1].i) + *signed_arg2;
  OF = (signed_result != signed_full_result);
  // set CF
  uint32_t unsigned_arg2 = static_cast<uint32_t>(*signed_arg2);
  uint32_t unsigned_result = Reg[arg1].u + unsigned_arg2;
  uint64_t unsigned_full_result = static_cast<uint64_t>(Reg[arg1].u) + unsigned_arg2;
  CF = (unsigned_result != unsigned_full_result);
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  Reg[arg1].i = signed_result;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[arg1].i << end();
  break;
}

:(code)
void test_add_mem_at_r32_to_r32_signed_overflow() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x7fffffff;  // largest positive signed integer
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  03     18                                    \n" // add *EAX to EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 1
  );
  CHECK_TRACE_CONTENTS(
      "run: add r/m32 to EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 1\n"
      "run: SF=1; ZF=0; CF=0; OF=1\n"
      "run: storing 0x80000000\n"
  );
}

void test_add_mem_at_r32_to_r32_unsigned_overflow() {
  Reg[EAX].u = 0x2000;
  Reg[EBX].u = 0xffffffff;  // largest unsigned number
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  03     18                                    \n" // add *EAX to EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"
  );
  CHECK_TRACE_CONTENTS(
      "run: add r/m32 to EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 1\n"
      "run: SF=0; ZF=1; CF=1; OF=0\n"
      "run: storing 0x00000000\n"
  );
}

void test_add_mem_at_r32_to_r32_unsigned_and_signed_overflow() {
  Reg[EAX].u = 0x2000;
  Reg[EBX].u = 0x80000000;  // smallest negative signed integer
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  03     18                                    \n" // add *EAX to EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "00 00 00 80\n"  // smallest negative signed integer
  );
  CHECK_TRACE_CONTENTS(
      "run: add r/m32 to EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 80000000\n"
      "run: SF=0; ZF=1; CF=1; OF=1\n"
      "run: storing 0x00000000\n"
  );
}

//:: subtract

:(code)
void test_subtract_r32_from_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 1;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  29     18                                    \n"  // subtract EBX from *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0a 00 00 00\n"  // 0x0000000a
  );
  CHECK_TRACE_CONTENTS(
      "run: subtract EBX from r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x00000009\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "2b", "subtract rm32 from r32 (sub)");

:(code)
void test_subtract_mem_at_r32_from_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 10;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  2b     18                                    \n"  // subtract *EAX from EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: subtract r/m32 from EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x00000009\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x2b: {  // subtract r/m32 from r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "subtract r/m32 from " << rname(arg1) << end();
  const int32_t* signed_arg2 = effective_address(modrm);
  const int32_t signed_result = Reg[arg1].i - *signed_arg2;
  SF = (signed_result < 0);
  ZF = (signed_result == 0);
  int64_t signed_full_result = static_cast<int64_t>(Reg[arg1].i) - *signed_arg2;
  OF = (signed_result != signed_full_result);
  // set CF
  uint32_t unsigned_arg2 = static_cast<uint32_t>(*signed_arg2);
  uint32_t unsigned_result = Reg[arg1].u - unsigned_arg2;
  uint64_t unsigned_full_result = static_cast<uint64_t>(Reg[arg1].u) - unsigned_arg2;
  CF = (unsigned_result != unsigned_full_result);
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  Reg[arg1].i = signed_result;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[arg1].i << end();
  break;
}

:(code)
void test_subtract_mem_at_r32_from_r32_signed_overflow() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x80000000;  // smallest negative signed integer
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  2b     18                                    \n"  // subtract *EAX from EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "ff ff ff 7f\n"  // largest positive signed integer
  );
  CHECK_TRACE_CONTENTS(
      "run: subtract r/m32 from EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 7fffffff\n"
      "run: SF=0; ZF=0; CF=0; OF=1\n"
      "run: storing 0x00000001\n"
  );
}

void test_subtract_mem_at_r32_from_r32_unsigned_overflow() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  2b     18                                    \n"  // subtract *EAX from EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 1
  );
  CHECK_TRACE_CONTENTS(
      "run: subtract r/m32 from EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 1\n"
      "run: SF=1; ZF=0; CF=1; OF=0\n"
      "run: storing 0xffffffff\n"
  );
}

void test_subtract_mem_at_r32_from_r32_signed_and_unsigned_overflow() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  2b     18                                    \n"  // subtract *EAX from EBX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "00 00 00 80\n"  // smallest negative signed integer
  );
  CHECK_TRACE_CONTENTS(
      "run: subtract r/m32 from EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 80000000\n"
      "run: SF=1; ZF=0; CF=1; OF=1\n"
      "run: storing 0x80000000\n"
  );
}

//:: and
:(code)
void test_and_r32_with_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xff;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  21     18                                    \n"  // and EBX with *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: and EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x0000000d\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "23", "r32 = bitwise AND of r32 with rm32 (and)");

:(code)
void test_and_mem_at_r32_with_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c0d;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  23     18                                    \n"  // and *EAX with EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "ff 00 00 00\n"  // 0x000000ff
  );
  CHECK_TRACE_CONTENTS(
      "run: and r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x0000000d\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x23: {  // and r/m32 with r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "and r/m32 with " << rname(arg1) << end();
  // bitwise ops technically operate on unsigned numbers, but it makes no
  // difference
  const int32_t* signed_arg2 = effective_address(modrm);
  Reg[arg1].i &= *signed_arg2;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[arg1].i << end();
  SF = (Reg[arg1].i >> 31);
  ZF = (Reg[arg1].i == 0);
  CF = false;
  OF = false;
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  break;
}

//:: or

:(code)
void test_or_r32_with_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xa0b0c0d0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  09     18                                   #\n"  // EBX with *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: or EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0xaabbccdd\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "0b", "r32 = bitwise OR of r32 with rm32 (or)");

:(code)
void test_or_mem_at_r32_with_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xa0b0c0d0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  0b     18                                    \n"  // or *EAX with EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: or r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0xaabbccdd\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x0b: {  // or r/m32 with r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "or r/m32 with " << rname(arg1) << end();
  // bitwise ops technically operate on unsigned numbers, but it makes no
  // difference
  const int32_t* signed_arg2 = effective_address(modrm);
  Reg[arg1].i |= *signed_arg2;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[arg1].i << end();
  SF = (Reg[arg1].i >> 31);
  ZF = (Reg[arg1].i == 0);
  CF = false;
  OF = false;
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  break;
}

//:: xor

:(code)
void test_xor_r32_with_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xa0b0c0d0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  31     18                                    \n"  // xor EBX with *EAX
      "== data 0x2000\n"
      "0d 0c bb aa\n"  // 0xaabb0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: xor EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x0a0bccdd\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "33", "r32 = bitwise XOR of r32 with rm32 (xor)");

:(code)
void test_xor_mem_at_r32_with_r32() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xa0b0c0d0;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  33     18                                    \n"  // xor *EAX with EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: xor r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0xaabbccdd\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x33: {  // xor r/m32 with r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "xor r/m32 with " << rname(arg1) << end();
  // bitwise ops technically operate on unsigned numbers, but it makes no
  // difference
  const int32_t* signed_arg2 = effective_address(modrm);
  Reg[arg1].i |= *signed_arg2;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[arg1].i << end();
  SF = (Reg[arg1].i >> 31);
  ZF = (Reg[arg1].i == 0);
  CF = false;
  OF = false;
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  break;
}

//:: not

:(code)
void test_not_of_mem_at_r32() {
  Reg[EBX].i = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  f7     13                                    \n"  // not *EBX
      // ModR/M in binary: 00 (indirect mode) 010 (subop not) 011 (dest EBX)
      "== data 0x2000\n"
      "ff 00 0f 0f\n"  // 0x0f0f00ff
  );
  CHECK_TRACE_CONTENTS(
      "run: operate on r/m32\n"
      "run: effective address is 0x00002000 (EBX)\n"
      "run: subop: not\n"
      "run: storing 0xf0f0ff00\n"
  );
}

//:: compare (cmp)

:(code)
void test_compare_mem_at_r32_with_r32_greater() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c07;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  39     18                                    \n"  // compare *EAX with EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: compare r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: SF=0; ZF=0; CF=0; OF=0\n"
  );
}

:(code)
void test_compare_mem_at_r32_with_r32_lesser() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c0d;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  39     18                                    \n"  // compare *EAX with EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "07 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: compare r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: SF=1; ZF=0; CF=1; OF=0\n"
  );
}

:(code)
void test_compare_mem_at_r32_with_r32_equal() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c0d;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  39     18                                    \n"  // compare *EAX and EBX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: compare r/m32 with EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: SF=0; ZF=1; CF=0; OF=0\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "3b", "compare: set SF if r32 < rm32 (cmp)");

:(code)
void test_compare_r32_with_mem_at_r32_greater() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c0d;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "07 0c 0b 0a\n"  // 0x0a0b0c07
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: SF=0; ZF=0; CF=0; OF=0\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x3b: {  // set SF if r32 < r/m32
  const uint8_t modrm = next();
  const uint8_t reg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "compare " << rname(reg1) << " with r/m32" << end();
  const int32_t* signed_arg2 = effective_address(modrm);
  const int32_t signed_difference = Reg[reg1].i - *signed_arg2;
  SF = (signed_difference < 0);
  ZF = (signed_difference == 0);
  int64_t full_signed_difference = static_cast<int64_t>(Reg[reg1].i) - *signed_arg2;
  OF = (signed_difference != full_signed_difference);
  const uint32_t unsigned_arg2 = static_cast<uint32_t>(*signed_arg2);
  const uint32_t unsigned_difference = Reg[reg1].u - unsigned_arg2;
  const uint64_t full_unsigned_difference = static_cast<uint64_t>(Reg[reg1].u) - unsigned_arg2;
  CF = (unsigned_difference != full_unsigned_difference);
  trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
  break;
}

:(code)
void test_compare_r32_with_mem_at_r32_lesser_unsigned_and_signed() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c07;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains a0b0c0d\n"
      "run: SF=1; ZF=0; CF=1; OF=0\n"
  );
}

void test_compare_r32_with_mem_at_r32_lesser_unsigned_and_signed_due_to_overflow() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x7fffffff;  // largest positive signed integer
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "00 00 00 80\n"  // smallest negative signed integer
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 80000000\n"
      "run: SF=1; ZF=0; CF=1; OF=1\n"
  );
}

void test_compare_r32_with_mem_at_r32_lesser_signed() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0xffffffff;  // -1
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 1
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains 1\n"
      "run: SF=1; ZF=0; CF=0; OF=0\n"
  );
}

void test_compare_r32_with_mem_at_r32_lesser_unsigned() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x00000001;  // 1
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "ff ff ff ff\n"  // -1
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: effective address contains ffffffff\n"
      "run: SF=0; ZF=0; CF=1; OF=0\n"
  );
}

void test_compare_r32_with_mem_at_r32_equal() {
  Reg[EAX].i = 0x2000;
  Reg[EBX].i = 0x0a0b0c0d;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  3b     18                                    \n"  // compare EBX with *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
      "== data 0x2000\n"
      "0d 0c 0b 0a\n"  // 0x0a0b0c0d
  );
  CHECK_TRACE_CONTENTS(
      "run: compare EBX with r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: SF=0; ZF=1; CF=0; OF=0\n"
  );
}

//:: copy (mov)

void test_copy_r32_to_mem_at_r32() {
  Reg[EBX].i = 0xaf;
  Reg[EAX].i = 0x60;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  89     18                                    \n"  // copy EBX to *EAX
      // ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX)
  );
  CHECK_TRACE_CONTENTS(
      "run: copy EBX to r/m32\n"
      "run: effective address is 0x00000060 (EAX)\n"
      "run: storing 0x000000af\n"
  );
}

//:

:(before "End Initialize Op Names")
put_new(Name, "8b", "copy rm32 to r32 (mov)");

:(code)
void test_copy_mem_at_r32_to_r32() {
  Reg[EAX].i = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  8b     18                                    \n"  // copy *EAX to EBX
      "== data 0x2000\n"
      "af 00 00 00\n"  // 0x000000af
  );
  CHECK_TRACE_CONTENTS(
      "run: copy r/m32 to EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: storing 0x000000af\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x8b: {  // copy r32 to r/m32
  const uint8_t modrm = next();
  const uint8_t rdest = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "copy r/m32 to " << rname(rdest) << end();
  const int32_t* src = effective_address(modrm);
  Reg[rdest].i = *src;
  trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << *src << end();
  break;
}

//:: jump

:(code)
void test_jump_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  ff     20                                    \n"  // jump to *EAX
      // ModR/M in binary: 00 (indirect mode) 100 (jump to r/m32) 000 (src EAX)
      "  b8                                 00 00 00 01\n"
      "  b8                                 00 00 00 02\n"
      "== data 0x2000\n"
      "08 00 00 00\n"  // 0x00000008
  );
  CHECK_TRACE_CONTENTS(
      "run: 0x00000001 opcode: ff\n"
      "run: jump to r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: jumping to 0x00000008\n"
      "run: 0x00000008 opcode: b8\n"
  );
  CHECK_TRACE_DOESNT_CONTAIN("run: 0x00000003 opcode: b8");
}

:(before "End Op ff Subops")
case 4: {  // jump to r/m32
  trace(Callstack_depth+1, "run") << "jump to r/m32" << end();
  const int32_t* arg2 = effective_address(modrm);
  EIP = *arg2;
  trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
  break;
}

//:: push

:(code)
void test_push_mem_at_r32() {
  Reg[EAX].i = 0x2000;
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000014;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  ff     30                                    \n"  // push *EAX to stack
      "== data 0x2000\n"
      "af 00 00 00\n"  // 0x000000af
  );
  CHECK_TRACE_CONTENTS(
      "run: push r/m32\n"
      "run: effective address is 0x00002000 (EAX)\n"
      "run: decrementing ESP to 0xbd000010\n"
      "run: pushing value 0x000000af\n"
  );
}

:(before "End Op ff Subops")
case 6: {  // push r/m32 to stack
  trace(Callstack_depth+1, "run") << "push r/m32" << end();
  const int32_t* val = effective_address(modrm);
  push(*val);
  break;
}

//:: pop

:(before "End Initialize Op Names")
put_new(Name, "8f", "pop top of stack to rm32 (pop)");

:(code)
void test_pop_mem_at_r32() {
  Reg[EAX].i = 0x60;
  Mem.push_back(vma(0xbd000000));  // manually allocate memory
  Reg[ESP].u = 0xbd000000;
  write_mem_i32(0xbd000000, 0x00000030);
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  8f     00                                    \n"  // pop stack into *EAX
      // ModR/M in binary: 00 (indirect mode) 000 (pop r/m32) 000 (dest EAX)
  );
  CHECK_TRACE_CONTENTS(
      "run: pop into r/m32\n"
      "run: effective address is 0x00000060 (EAX)\n"
      "run: popping value 0x00000030\n"
      "run: incrementing ESP to 0xbd000004\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x8f: {  // pop stack into r/m32
  const uint8_t modrm = next();
  const uint8_t subop = (modrm>>3)&0x7;
  switch (subop) {
    case 0: {
      trace(Callstack_depth+1, "run") << "pop into r/m32" << end();
      int32_t* dest = effective_address(modrm);
      *dest = pop();
      break;
    }
  }
  break;
}

//:: special-case for loading address from disp32 rather than register

:(code)
void test_add_r32_to_mem_at_displacement() {
  Reg[EBX].i = 0x10;  // source
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     1d            00 20 00 00             \n"  // add EBX to *0x2000
      // ModR/M in binary: 00 (indirect mode) 011 (src EBX) 101 (dest in disp32)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is 0x00002000 (disp32)\n"
      "run: storing 0x00000011\n"
  );
}

:(before "End Mod 0 Special-cases(addr)")
case 5:  // exception: mod 0b00 rm 0b101 => incoming disp32
  addr = next32();
  trace(Callstack_depth+1, "run") << "effective address is 0x" << HEXWORD << addr << " (disp32)" << end();
  break;

//:

:(code)
void test_add_r32_to_mem_at_r32_plus_disp8() {
  Reg[EBX].i = 0x10;  // source
  Reg[EAX].i = 0x1ffe;  // dest
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     58            02                      \n"  // add EBX to *(EAX+2)
      // ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is initially 0x00001ffe (EAX)\n"
      "run: effective address is 0x00002000 (after adding disp8)\n"
      "run: storing 0x00000011\n"
  );
}

:(before "End Mod Special-cases(addr)")
case 1: {  // indirect + disp8 addressing
  switch (rm) {
  default:
    addr = Reg[rm].u;
    trace(Callstack_depth+1, "run") << "effective address is initially 0x" << HEXWORD << addr << " (" << rname(rm) << ")" << end();
    break;
  // End Mod 1 Special-cases(addr)
  }
  int8_t displacement = static_cast<int8_t>(next());
  if (addr > 0) {
    addr += displacement;
    trace(Callstack_depth+1, "run") << "effective address is 0x" << HEXWORD << addr << " (after adding disp8)" << end();
  }
  else {
    trace(Callstack_depth+1, "run") << "null address; skipping displacement" << end();
  }
  break;
}

:(code)
void test_add_r32_to_mem_at_r32_plus_negative_disp8() {
  Reg[EBX].i = 0x10;  // source
  Reg[EAX].i = 0x2001;  // dest
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     58            ff                      \n"  // add EBX to *(EAX-1)
      // ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is initially 0x00002001 (EAX)\n"
      "run: effective address is 0x00002000 (after adding disp8)\n"
      "run: storing 0x00000011\n"
  );
}

//:

:(code)
void test_add_r32_to_mem_at_r32_plus_disp32() {
  Reg[EBX].i = 0x10;  // source
  Reg[EAX].i = 0x1ffe;  // dest
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     98            02 00 00 00             \n"  // add EBX to *(EAX+2)
      // ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is initially 0x00001ffe (EAX)\n"
      "run: effective address is 0x00002000 (after adding disp32)\n"
      "run: storing 0x00000011\n"
  );
}

:(before "End Mod Special-cases(addr)")
case 2:  // indirect + disp32 addressing
  switch (rm) {
  default:
    addr = Reg[rm].u;
    trace(Callstack_depth+1, "run") << "effective address is initially 0x" << HEXWORD << addr << " (" << rname(rm) << ")" << end();
    break;
  // End Mod 2 Special-cases(addr)
  }
  if (addr > 0) {
    addr += next32();
    trace(Callstack_depth+1, "run") << "effective address is 0x" << HEXWORD << addr << " (after adding disp32)" << end();
  }
  break;

:(code)
void test_add_r32_to_mem_at_r32_plus_negative_disp32() {
  Reg[EBX].i = 0x10;  // source
  Reg[EAX].i = 0x2001;  // dest
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  01     98            ff ff ff ff             \n"  // add EBX to *(EAX-1)
      // ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 000 (dest EAX)
      "== data 0x2000\n"
      "01 00 00 00\n"  // 0x00000001
  );
  CHECK_TRACE_CONTENTS(
      "run: add EBX to r/m32\n"
      "run: effective address is initially 0x00002001 (EAX)\n"
      "run: effective address is 0x00002000 (after adding disp32)\n"
      "run: storing 0x00000011\n"
  );
}

//:: copy address (lea)

:(before "End Initialize Op Names")
put_new(Name, "8d", "copy address in rm32 into r32 (lea)");

:(code)
void test_copy_address() {
  Reg[EAX].u = 0x2000;
  run(
      "== code 0x1\n"
      // op     ModR/M  SIB   displacement  immediate
      "  8d     18                                    \n"  // copy address in EAX into EBX
      // ModR/M in binary: 00 (indirect mode) 011 (dest EBX) 000 (src EAX)
  );
  CHECK_TRACE_CONTENTS(
      "run: copy address into EBX\n"
      "run: effective address is 0x00002000 (EAX)\n"
  );
}

:(before "End Single-Byte Opcodes")
case 0x8d: {  // copy address of m32 to r32
  const uint8_t modrm = next();
  const uint8_t arg1 = (modrm>>3)&0x7;
  trace(Callstack_depth+1, "run") << "copy address into " << rname(arg1) << end();
  Reg[arg1].u = effective_address_number(modrm);
  break;
}