mirrors/ladybird
0
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-06-01 16:02:53 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

LibJS: Make typeof a lot faster by caching all possible results

Browse source 
The typeof operator has a very small set of possible resulting strings,
so let's make it much faster by caching those strings on the VM.

~8x speed-up on this microbenchmark:

    for (let i = 0; i < 10_000_000; ++i) {
        typeof i;
    }
This commit is contained in:
Andreas Kling 2024-07-23 09:42:00 +02:00 • committed by Andreas Kling
parent 3b7534b362
commit d0b11af387
Notes: github-actions[bot] 2024-07-23 09:48:32 +00:00
5 changed files with 46 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

8
Userland/Libraries/LibJS/Bytecode/Interpreter.cpp
View file

@ -1193,7 +1193,7 @@ inline ThrowCompletionOr<void> put_by_property_key(VM& vm, Value base, Value thi
if (!succeeded && vm.in_strict_mode()) {
if (base.is_object())
return vm.throw_completion<TypeError>(ErrorType::ReferenceNullishSetProperty, name, base.to_string_without_side_effects());
return vm.throw_completion<TypeError>(ErrorType::ReferencePrimitiveSetProperty, name, base.typeof(), base.to_string_without_side_effects());
return vm.throw_completion<TypeError>(ErrorType::ReferencePrimitiveSetProperty, name, base.typeof(vm)->utf8_string(), base.to_string_without_side_effects());
}
break;
}
@ -2018,7 +2018,7 @@ static ThrowCompletionOr<Value> not_(VM&, Value value)
static ThrowCompletionOr<Value> typeof_(VM& vm, Value value)
{
return PrimitiveString::create(vm, value.typeof());
return value.typeof(vm);
}
#define JS_DEFINE_COMMON_UNARY_OP(OpTitleCase, op_snake_case) \
@ -2873,7 +2873,7 @@ ThrowCompletionOr<void> TypeofBinding::execute_impl(Bytecode::Interpreter& inter
environment = environment->outer_environment();
if (!environment->is_permanently_screwed_by_eval()) {
auto value = TRY(static_cast<DeclarativeEnvironment const&>(*environment).get_binding_value_direct(vm, m_cache.index));
interpreter.set(dst(), PrimitiveString::create(vm, value.typeof()));
interpreter.set(dst(), value.typeof(vm));
return {};
}
m_cache = {};
@ -2897,7 +2897,7 @@ ThrowCompletionOr<void> TypeofBinding::execute_impl(Bytecode::Interpreter& inter
// 4. NOTE: This step is replaced in section B.3.6.3.
// 5. Return a String according to Table 41.
interpreter.set(dst(), PrimitiveString::create(vm, value.typeof()));
interpreter.set(dst(), value.typeof(vm));
return {};
}