mu/subx/018jump_disp32.cc
Kartik Agaram 50dcc0c122 4776
Crenshaw compiler now runs natively as well.

It turns out I was misreading the Intel manual, and the jump instructions
that I thought take disp16 operands actually take disp32 operands by default
on both i686 and x86_64 processors. The disp16 versions are some holdover
from the 16-bit days.

This was the first time I've used one of these erstwhile-disp16 instructions,
but I still haven't tested most of them. We'll see if we run into future
issues.
2018-11-25 13:46:53 -08:00

288 lines
7.6 KiB
C++

//: jump to 32-bit offset
//:: jump
:(before "End Initialize Op Names")
put_new(Name, "e9", "jump disp32 bytes away (jmp)");
:(scenario jump_disp32)
== 0x1
# op ModR/M SIB displacement immediate
e9 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000b
-run: inst: 0x00000006
:(before "End Single-Byte Opcodes")
case 0xe9: { // jump disp32
const int32_t offset = next32();
trace(90, "run") << "jump " << offset << end();
EIP += offset;
break;
}
//:: jump if equal/zero
:(before "End Initialize Op Names")
put_new(Name_0f, "84", "jump disp32 bytes away if equal, if ZF is set (jcc/jz/je)");
:(scenario je_disp32_success)
% ZF = true;
== 0x1
# op ModR/M SIB displacement immediate
0f 84 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x84: { // jump disp32 if ZF
const int32_t offset = next32();
if (ZF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario je_disp32_fail)
% ZF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 84 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5
//:: jump if not equal/not zero
:(before "End Initialize Op Names")
put_new(Name_0f, "85", "jump disp32 bytes away if not equal, if ZF is not set (jcc/jnz/jne)");
:(scenario jne_disp32_success)
% ZF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 85 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x85: { // jump disp32 unless ZF
const int32_t offset = next32();
if (!ZF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jne_disp32_fail)
% ZF = true;
== 0x1
# op ModR/M SIB displacement immediate
0f 85 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5
//:: jump if greater
:(before "End Initialize Op Names")
put_new(Name_0f, "8f", "jump disp32 bytes away if greater, if ZF is unset and SF == OF (jcc/jg/jnle)");
:(scenario jg_disp32_success)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8f 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8f: { // jump disp32 if !SF and !ZF
const int32_t offset = next32();
if (!ZF && SF == OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jg_disp32_fail)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8f 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5
//:: jump if greater or equal
:(before "End Initialize Op Names")
put_new(Name_0f, "8d", "jump disp32 bytes away if greater or equal, if SF == OF (jcc/jge/jnl)");
:(scenario jge_disp32_success)
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8d 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8d: { // jump disp32 if !SF
const int32_t offset = next32();
if (SF == OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jge_disp32_fail)
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8d 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5
//:: jump if lesser
:(before "End Initialize Op Names")
put_new(Name_0f, "8c", "jump disp32 bytes away if lesser, if SF != OF (jcc/jl/jnge)");
:(scenario jl_disp32_success)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8c 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8c: { // jump disp32 if SF and !ZF
const int32_t offset = next32();
if (SF != OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jl_disp32_fail)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8c 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5
//:: jump if lesser or equal
:(before "End Initialize Op Names")
put_new(Name_0f, "8e", "jump disp32 bytes away if lesser or equal, if ZF is set or SF != OF (jcc/jle/jng)");
:(scenario jle_disp32_equal)
% ZF = true;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8e 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(scenario jle_disp32_lesser)
% ZF = false;
% SF = true;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8e 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: jump 5
+run: inst: 0x0000000c
-run: inst: 0x00000007
:(before "End Two-Byte Opcodes Starting With 0f")
case 0x8e: { // jump disp32 if SF or ZF
const int32_t offset = next32();
if (ZF || SF != OF) {
trace(90, "run") << "jump " << NUM(offset) << end();
EIP += offset;
}
break;
}
:(scenario jle_disp32_greater)
% ZF = false;
% SF = false;
% OF = false;
== 0x1
# op ModR/M SIB displacement immediate
0f 8e 05 00 00 00 # skip 1 instruction
05 00 00 00 01
05 00 00 00 02
+run: inst: 0x00000001
+run: inst: 0x00000007
+run: inst: 0x0000000c
-run: jump 5