blob: b48b20723db654ab0f89ac4c8e9e5fbb3f2b5b40 (
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
|
//: jump to 16-bit offset
//:: jump
:(scenario jump_rel16)
# op ModRM SIB displacement immediate
e9 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x00000009
-run: inst: 0x00000003
:(before "End Single-Byte Opcodes")
case 0xe9: { // jump rel8
int16_t offset = imm16();
trace(2, "run") << "jump " << offset << end();
EIP += offset;
break;
}
:(code)
int16_t imm16() {
int16_t result = next();
result |= (next()<<8);
return result;
}
//:: jump if equal/zero
:(scenario je_rel16_success)
% ZF = true;
# op ModRM SIB displacement immediate
0f 84 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x84: { // jump rel16 if ZF
int8_t offset = imm16();
if (ZF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario je_rel16_fail)
% ZF = false;
# op ModRM SIB displacement immediate
0f 84 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
//:: jump if not equal/not zero
:(scenario jne_rel16_success)
% ZF = false;
# op ModRM SIB displacement immediate
0f 85 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x85: { // jump rel16 unless ZF
int8_t offset = imm16();
if (!ZF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jne_rel16_fail)
% ZF = true;
# op ModRM SIB displacement immediate
0f 85 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
//:: jump if greater
:(scenario jg_rel16_success)
% ZF = false;
% SF = false;
% OF = false;
# op ModRM SIB displacement immediate
0f 8f 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8f: { // jump rel16 if !SF and !ZF
int8_t offset = imm16();
if (!ZF && SF == OF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jg_rel16_fail)
% ZF = false;
% SF = true;
% OF = false;
# op ModRM SIB displacement immediate
0f 8f 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
//:: jump if greater or equal
:(scenario jge_rel16_success)
% SF = false;
% OF = false;
# op ModRM SIB displacement immediate
0f 8d 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8d: { // jump rel16 if !SF
int8_t offset = imm16();
if (SF == OF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jge_rel16_fail)
% SF = true;
% OF = false;
# op ModRM SIB displacement immediate
0f 8d 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
//:: jump if lesser
:(scenario jl_rel16_success)
% ZF = false;
% SF = true;
% OF = false;
# op ModRM SIB displacement immediate
0f 8c 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8c: { // jump rel16 if SF and !ZF
int8_t offset = imm16();
if (SF != OF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jl_rel16_fail)
% ZF = false;
% SF = false;
% OF = false;
# op ModRM SIB displacement immediate
0f 8c 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
//:: jump if lesser or equal
:(scenario jle_rel16_equal)
% ZF = true;
% SF = false;
% OF = false;
# op ModRM SIB displacement immediate
0f 8e 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(scenario jle_rel16_lesser)
% ZF = false;
% SF = true;
% OF = false;
# op ModRM SIB displacement immediate
0f 8e 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000a
-run: inst: 0x00000005
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8e: { // jump rel16 if SF or ZF
int8_t offset = imm16();
if (ZF || SF != OF) {
trace(2, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jle_rel16_greater)
% ZF = false;
% SF = false;
% OF = false;
# op ModRM SIB displacement immediate
0f 8e 05 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000005
+run: inst: 0x0000000a
-run: jump 5
|