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LibX86: Only pass ProcessorMode to Instruction constructor

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We previously passed both OperandSize and AddressSize to the
constructor.

Both values were only ever 32-bit at construction.
We used AddressSize::Size64 to signify Long mode which was needlessly
complicated.
This commit is contained in:
Itamar 2022-12-10 20:00:09 +02:00 • committed by Andreas Kling
parent 9a136e354d
commit 108a8e4c88
Notes: sideshowbarker 2024-07-17 04:10:16 +09:00
3 changed files with 14 additions and 19 deletions
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6
Userland/DevTools/UserspaceEmulator/Emulator.cpp
View file

@ -234,7 +234,7 @@ int Emulator::exec()
while (!m_shutdown) {
if (m_steps_til_pause) [[likely]] {
m_cpu->save_base_eip();
auto insn = X86::Instruction::from_stream(*m_cpu, X86::OperandSize::Size32, X86::AddressSize::Size32);
auto insn = X86::Instruction::from_stream(*m_cpu, X86::ProcessorMode::Protected);
// Exec cycle
if constexpr (trace) {
outln("{:p} \033[33;1m{}\033[0m", m_cpu->base_eip(), insn.to_deprecated_string(m_cpu->base_eip(), symbol_provider));
@ -301,7 +301,7 @@ void Emulator::handle_repl()
// FIXME: Function names (base, call, jump)
auto saved_eip = m_cpu->eip();
m_cpu->save_base_eip();
auto insn = X86::Instruction::from_stream(*m_cpu, X86::OperandSize::Size32, X86::AddressSize::Size32);
auto insn = X86::Instruction::from_stream(*m_cpu, X86::ProcessorMode::Protected);
// FIXME: This does not respect inlining
// another way of getting the current function is at need
if (auto symbol = symbol_at(m_cpu->base_eip()); symbol.has_value()) {
@ -311,7 +311,7 @@ void Emulator::handle_repl()
outln("==> {}", create_instruction_line(m_cpu->base_eip(), insn));
for (int i = 0; i < 7; ++i) {
m_cpu->save_base_eip();
insn = X86::Instruction::from_stream(*m_cpu, X86::OperandSize::Size32, X86::AddressSize::Size32);
insn = X86::Instruction::from_stream(*m_cpu, X86::ProcessorMode::Protected);
outln(" {}", create_instruction_line(m_cpu->base_eip(), insn));
}
// We don't want to increase EIP here, we just want the instructions

4
Userland/Libraries/LibX86/Disassembler.h
View file

@ -23,10 +23,10 @@ public:
if (!m_stream.can_read())
return {};
#if ARCH(I386)
return Instruction::from_stream(m_stream, OperandSize::Size32, AddressSize::Size32);
return Instruction::from_stream(m_stream, ProcessorMode::Protected);
#else
# if ARCH(X86_64)
return Instruction::from_stream(m_stream, OperandSize::Size32, AddressSize::Size64);
return Instruction::from_stream(m_stream, ProcessorMode::Long);
# else
dbgln("Unsupported platform");
return {};

23
Userland/Libraries/LibX86/Instruction.h
View file

@ -618,7 +618,7 @@ private:
class Instruction {
public:
template<typename InstructionStreamType>
static Instruction from_stream(InstructionStreamType&, OperandSize, AddressSize);
static Instruction from_stream(InstructionStreamType&, ProcessorMode);
~Instruction() = default;
ALWAYS_INLINE MemoryOrRegisterReference& modrm() const { return m_modrm; }
@ -699,7 +699,7 @@ public:
private:
template<typename InstructionStreamType>
Instruction(InstructionStreamType&, OperandSize, AddressSize);
Instruction(InstructionStreamType&, ProcessorMode);
void to_deprecated_string_internal(StringBuilder&, u32 origin, SymbolProvider const*, bool x32) const;
@ -961,9 +961,9 @@ ALWAYS_INLINE typename CPU::ValueWithShadowType256 MemoryOrRegisterReference::re
}
template<typename InstructionStreamType>
ALWAYS_INLINE Instruction Instruction::from_stream(InstructionStreamType& stream, OperandSize operand_size, AddressSize address_size)
ALWAYS_INLINE Instruction Instruction::from_stream(InstructionStreamType& stream, ProcessorMode mode)
{
return Instruction(stream, operand_size, address_size);
return Instruction(stream, mode);
}
ALWAYS_INLINE unsigned Instruction::length() const
@ -1002,19 +1002,14 @@ ALWAYS_INLINE Optional<SegmentRegister> to_segment_prefix(u8 op)
}
template<typename InstructionStreamType>
ALWAYS_INLINE Instruction::Instruction(InstructionStreamType& stream, OperandSize operand_size, AddressSize address_size)
: m_operand_size(operand_size)
, m_address_size(address_size)
ALWAYS_INLINE Instruction::Instruction(InstructionStreamType& stream, ProcessorMode mode)
: m_mode(mode)
{
VERIFY(operand_size != OperandSize::Size64);
// Use address_size as the hint to switch into long mode.
m_operand_size = OperandSize::Size32;
// m_address_size refers to the default size of displacements/immediates, which is 32 even in long mode (2.2.1.3 Displacement, 2.2.1.5 Immediates),
// with the exception of moffset (see below).
if (address_size == AddressSize::Size64) {
m_operand_size = OperandSize::Size32;
m_address_size = AddressSize::Size32;
m_mode = ProcessorMode::Long;
}
m_address_size = AddressSize::Size32;
u8 prefix_bytes = 0;
for (;; ++prefix_bytes) {
u8 opbyte = stream.read8();