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LibJS/JIT: Add fast path for cached GetById

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This commit is contained in:
Andreas Kling 2023-11-09 10:16:50 +01:00
parent 55e467c359
commit ac23ab42b3
Notes: sideshowbarker 2024-07-17 17:40:13 +09:00 
Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/ac23ab42b3
Pull-request: https://github.com/SerenityOS/serenity/pull/21859
1 changed files with 103 additions and 1 deletions
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104
Userland/Libraries/LibJS/JIT/Compiler.cpp
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@ -1085,16 +1085,118 @@ static Value cxx_get_by_id(VM& vm, Value base, DeprecatedFlyString const& proper
void Compiler::compile_get_by_id(Bytecode::Op::GetById const& op)
{
auto& cache = m_bytecode_executable.property_lookup_caches[op.cache_index()];
Assembler::Label end;
Assembler::Label slow_case;
m_assembler.mov(
Assembler::Operand::Register(ARG5),
Assembler::Operand::Imm(bit_cast<u64>(&cache)));
load_accumulator(ARG1);
branch_if_object(ARG1, [&] {
extract_object_pointer(GPR0, ARG1);
// if (cache.shape != &object->shape()) goto slow_case;
m_assembler.mov(
Assembler::Operand::Register(GPR2),
Assembler::Operand::Mem64BaseAndOffset(GPR0, Object::shape_offset()));
m_assembler.mov(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(ARG5, Bytecode::PropertyLookupCache::shape_offset()));
m_assembler.jump_if(
Assembler::Operand::Register(GPR1),
Assembler::Condition::EqualTo,
Assembler::Operand::Imm(0),
slow_case);
m_assembler.mov(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(GPR1, AK::WeakLink::ptr_offset()));
m_assembler.jump_if(
Assembler::Operand::Register(GPR2),
Assembler::Condition::NotEqualTo,
Assembler::Operand::Register(GPR1),
slow_case);
// (!object->shape().is_unique() || object->shape().unique_shape_serial_number() == cache.unique_shape_serial_number)) {
Assembler::Label fast_case;
// GPR1 = object->shape().is_unique()
m_assembler.mov8(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(GPR2, Shape::is_unique_offset()));
m_assembler.jump_if(
Assembler::Operand::Register(GPR1),
Assembler::Condition::EqualTo,
Assembler::Operand::Imm(0),
fast_case);
// GPR1 = object->shape().unique_shape_serial_number()
m_assembler.mov(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(GPR2, Shape::unique_shape_serial_number_offset()));
// GPR2 = cache.unique_shape_serial_number
m_assembler.mov(
Assembler::Operand::Register(GPR2),
Assembler::Operand::Mem64BaseAndOffset(ARG5, Bytecode::PropertyLookupCache::unique_shape_serial_number_offset()));
// if (GPR1 != GPR2) goto slow_case;
m_assembler.jump_if(
Assembler::Operand::Register(GPR1),
Assembler::Condition::NotEqualTo,
Assembler::Operand::Register(GPR2),
slow_case);
fast_case.link(m_assembler);
// return object->get_direct(*cache.property_offset);
// GPR0 = object
// GPR1 = *cache.property_offset * sizeof(Value)
m_assembler.mov(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(ARG5, Bytecode::PropertyLookupCache::property_offset_offset() + decltype(cache.property_offset)::value_offset()));
m_assembler.mul32(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Imm(sizeof(Value)),
slow_case);
// GPR0 = object->m_storage.outline_buffer
m_assembler.mov(
Assembler::Operand::Register(GPR0),
Assembler::Operand::Mem64BaseAndOffset(GPR0, Object::storage_offset() + Vector<Value>::outline_buffer_offset()));
// GPR0 = &object->m_storage.outline_buffer[*cache.property_offset]
m_assembler.add(
Assembler::Operand::Register(GPR0),
Assembler::Operand::Register(GPR1));
// *GPR0 = value
m_assembler.mov(
Assembler::Operand::Register(GPR1),
Assembler::Operand::Mem64BaseAndOffset(GPR0, 0));
store_accumulator(GPR1);
m_assembler.jump(end);
});
slow_case.link(m_assembler);
m_assembler.mov(
Assembler::Operand::Register(ARG2),
Assembler::Operand::Imm(bit_cast<u64>(&m_bytecode_executable.get_identifier(op.property()))));
m_assembler.mov(
Assembler::Operand::Register(ARG3),
Assembler::Operand::Imm(bit_cast<u64>(&m_bytecode_executable.property_lookup_caches[op.cache_index()])));
Assembler::Operand::Imm(bit_cast<u64>(&cache)));
native_call((void*)cxx_get_by_id);
store_accumulator(RET);
check_exception();
end.link(m_assembler);
}
static Value cxx_get_by_value(VM& vm, Value base, Value property)