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
|
//: jump to 8-bit offset
//:: jump
:(before "End Initialize Op Names(name)")
put(name, "eb", "jump disp8 bytes away");
:(scenario jump_rel8)
== 0x1
# op ModR/M SIB displacement immediate
eb 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0xeb: { // jump rel8
int8_t offset = static_cast<int>(next());
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
break;
}
//:: jump if equal/zero
:(before "End Initialize Op Names(name)")
put(name, "74", "jump disp8 bytes away if ZF is set");
:(scenario je_rel8_success)
% ZF = true;
== 0x1
# op ModR/M SIB displacement immediate
74 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x74: { // jump rel8 if ZF
int8_t offset = static_cast<int>(next());
if (ZF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario je_rel8_fail)
% ZF = false;
== 0x1
# op ModR/M SIB displacement immediate
74 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
//:: jump if not equal/not zero
:(before "End Initialize Op Names(name)")
put(name, "75", "jump disp8 bytes away if ZF is not set");
:(scenario jne_rel8_success)
% ZF = false;
== 0x1
# op ModR/M SIB displacement immediate
75 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x75: { // jump rel8 unless ZF
int8_t offset = static_cast<int>(next());
if (!ZF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jne_rel8_fail)
% ZF = true;
== 0x1
# op ModR/M SIB displacement immediate
75 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
//:: jump if greater
:(before "End Initialize Op Names(name)")
put(name, "7f", "jump disp8 bytes away if greater (ZF is unset, SF == OF)");
:(scenario jg_rel8_success)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7f 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x7f: { // jump rel8 if !SF and !ZF
int8_t offset = static_cast<int>(next());
if (!ZF && SF == OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jg_rel8_fail)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7f 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
//:: jump if greater or equal
:(before "End Initialize Op Names(name)")
put(name, "7d", "jump disp8 bytes away if greater or equal (SF == OF)");
:(scenario jge_rel8_success)
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7d 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x7d: { // jump rel8 if !SF
int8_t offset = static_cast<int>(next());
if (SF == OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jge_rel8_fail)
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7d 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
//:: jump if lesser
:(before "End Initialize Op Names(name)")
put(name, "7c", "jump disp8 bytes away if lesser (SF != OF)");
:(scenario jl_rel8_success)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7c 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x7c: { // jump rel8 if SF and !ZF
int8_t offset = static_cast<int>(next());
if (SF != OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jl_rel8_fail)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7c 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
//:: jump if lesser or equal
:(before "End Initialize Op Names(name)")
put(name, "7e", "jump disp8 bytes away if lesser or equal (ZF is set or SF != OF)");
:(scenario jle_rel8_equal)
% ZF = true;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7e 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(scenario jle_rel8_lesser)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7e 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000008
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0x7e: { // jump rel8 if SF or ZF
int8_t offset = static_cast<int>(next());
if (ZF || SF != OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jle_rel8_greater)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
7e 05 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000003
+run: inst: 0x00000008
-run: jump 5
|