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LibX86: Use AddressSize::32 in Long mode

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As the existing near-by comment says, the default size of displacements
& immediates is 32 bits even in Long mode.

This makes `disasm` work on our binaries in x86-64 builds.
This commit is contained in:
Itamar 2022-12-10 15:05:07 +02:00 • committed by Andreas Kling
parent dd66f5e838
commit 9a136e354d
1 changed files with 5 additions and 4 deletions
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9
Userland/Libraries/LibX86/Instruction.h
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@ -1007,11 +1007,12 @@ ALWAYS_INLINE Instruction::Instruction(InstructionStreamType& stream, OperandSiz
, m_address_size(address_size) , m_address_size(address_size)
{ {
VERIFY(operand_size != OperandSize::Size64); VERIFY(operand_size != OperandSize::Size64);
// Use address_size as the hint to switch into long mode, m_address_size refers to the default // Use address_size as the hint to switch into long mode.
// size of displacements/immediates, which is 32 even in long mode, with the exception of moffset (see below). // 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) { if (address_size == AddressSize::Size64) {
m_operand_size = OperandSize::Size32; m_operand_size = OperandSize::Size32;
m_address_size = AddressSize::Size64; m_address_size = AddressSize::Size32;
m_mode = ProcessorMode::Long; m_mode = ProcessorMode::Long;
} }
u8 prefix_bytes = 0; u8 prefix_bytes = 0;
@ -1124,7 +1125,7 @@ ALWAYS_INLINE Instruction::Instruction(InstructionStreamType& stream, OperandSiz
return; return;
} }
// 2.2.1.3 Direct Memory-Offset MOVs // 2.2.1.4 Direct Memory-Offset MOVs
auto effective_address_size = m_address_size; auto effective_address_size = m_address_size;
if (m_mode == ProcessorMode::Long) { if (m_mode == ProcessorMode::Long) {
switch (m_descriptor->format) { switch (m_descriptor->format) {