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//: jump to 16-bit offset
//:: jump
:(scenario jump_rel16)
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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;
== 0x1
# op ModR/M 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
|