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LibX86: Split up the ModRM and SIB bytes into multiple members

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This will allow adding extra bits with REX prefixes
This commit is contained in:
Simon Wanner 2022-03-27 22:52:49 +02:00 • committed by Andreas Kling
parent 4041ea835c
commit 735fd5f5db
2 changed files with 60 additions and 118 deletions
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122
Userland/Libraries/LibX86/Instruction.cpp
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@ -1371,79 +1371,35 @@ String MemoryOrRegisterReference::to_string_a16() const
return String::formatted("{}{}", base, displacement_string);
}
static String sib_to_string(u8 rm, u8 sib)
String MemoryOrRegisterReference::sib_to_string(ProcessorMode) const
{
String scale;
String index;
String base;
switch (sib & 0xC0) {
case 0x00:;
switch (m_sib_scale) {
case 0:;
break;
case 0x40:
case 1:
scale = "*2";
break;
case 0x80:
case 2:
scale = "*4";
break;
case 0xC0:
case 3:
scale = "*8";
break;
}
switch ((sib >> 3) & 0x07) {
case 0:
index = "eax";
break;
case 1:
index = "ecx";
break;
case 2:
index = "edx";
break;
case 3:
index = "ebx";
break;
case 4:
break;
case 5:
index = "ebp";
break;
case 6:
index = "esi";
break;
case 7:
index = "edi";
break;
}
switch (sib & 0x07) {
case 0:
base = "eax";
break;
case 1:
base = "ecx";
break;
case 2:
base = "edx";
break;
case 3:
base = "ebx";
break;
case 4:
base = "esp";
break;
case 6:
base = "esi";
break;
case 7:
base = "edi";
break;
default: // 5
switch ((rm >> 6) & 3) {
if (m_sib_index != 4)
index = register_name(RegisterIndex32(m_sib_index));
if (m_sib_base == 5) {
switch (m_reg) {
case 1:
case 2:
base = "ebp";
break;
}
break;
} else {
base = register_name(RegisterIndex32(m_sib_base));
}
StringBuilder builder;
if (base.is_empty()) {
@ -1467,35 +1423,17 @@ String MemoryOrRegisterReference::to_string_a64() const
bool has_displacement = false;
switch (mod()) {
case 0b00:
has_displacement = rm() == 5;
has_displacement = m_rm == 5;
break;
case 0b01:
case 0b10:
has_displacement = true;
}
if (m_has_sib && (m_sib & 7) == 5)
if (m_has_sib && m_sib_base == 5)
has_displacement = true;
String base;
switch (rm()) {
case 0:
base = "rax";
break;
case 1:
base = "rcx";
break;
case 2:
base = "rdx";
break;
case 3:
base = "rbx";
break;
case 6:
base = "rsi";
break;
case 7:
base = "rdi";
break;
switch (m_rm) {
case 5:
if (mod() == 0)
base = String::formatted("{:#08x}", m_displacement32);
@ -1503,8 +1441,10 @@ String MemoryOrRegisterReference::to_string_a64() const
base = "rbp";
break;
case 4:
base = sib_to_string(m_rm_byte, m_sib);
base = sib_to_string(ProcessorMode::Long);
break;
default:
base = register_name(RegisterIndex32(m_rm));
}
if (!has_displacement)
@ -1529,29 +1469,11 @@ String MemoryOrRegisterReference::to_string_a32() const
case 0b10:
has_displacement = true;
}
if (m_has_sib && (m_sib & 7) == 5)
if (m_has_sib && m_sib_base == 5)
has_displacement = true;
String base;
switch (rm()) {
case 0:
base = "eax";
break;
case 1:
base = "ecx";
break;
case 2:
base = "edx";
break;
case 3:
base = "ebx";
break;
case 6:
base = "esi";
break;
case 7:
base = "edi";
break;
switch (m_rm) {
case 5:
if (mod() == 0)
base = String::formatted("{:x}", m_displacement32);
@ -1559,8 +1481,10 @@ String MemoryOrRegisterReference::to_string_a32() const
base = "ebp";
break;
case 4:
base = sib_to_string(m_rm_byte, m_sib);
base = sib_to_string(ProcessorMode::Protected);
break;
default:
base = register_name(RegisterIndex32(m_rm));
}
if (!has_displacement)