1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 06:47:34 +00:00

LibJS/JIT: Add fast path for cached GetVariable accesses

We can now stay in machine code for environment variable read accesses
as long as they are cached and initialized.

20% speed-up on Octane/zlib.js :^)
This commit is contained in:
Andreas Kling 2023-11-06 15:23:49 +01:00
parent 7826c006c1
commit 1d8ec677a3
6 changed files with 147 additions and 3 deletions

View file

@ -19,6 +19,9 @@ class DeclarativeEnvironment : public Environment {
JS_ENVIRONMENT(DeclarativeEnvironment, Environment);
struct Binding {
static FlatPtr value_offset() { return OFFSET_OF(Binding, value); }
static FlatPtr initialized_offset() { return OFFSET_OF(Binding, initialized); }
DeprecatedFlyString name;
Value value;
bool strict { false };
@ -67,6 +70,8 @@ public:
[[nodiscard]] u64 environment_serial_number() const { return m_environment_serial_number; }
static FlatPtr bindings_offset() { return OFFSET_OF(DeclarativeEnvironment, m_bindings); }
private:
ThrowCompletionOr<Value> get_binding_value_direct(VM&, Binding&, bool strict);
ThrowCompletionOr<void> set_mutable_binding_direct(VM&, Binding&, Value, bool strict);

View file

@ -57,6 +57,9 @@ public:
bool is_permanently_screwed_by_eval() const { return m_permanently_screwed_by_eval; }
void set_permanently_screwed_by_eval();
static FlatPtr is_permanently_screwed_by_eval_offset() { return OFFSET_OF(Environment, m_permanently_screwed_by_eval); }
static FlatPtr outer_environment_offset() { return OFFSET_OF(Environment, m_outer_environment); }
protected:
explicit Environment(Environment* parent);

View file

@ -15,6 +15,9 @@ struct EnvironmentCoordinate {
u32 hops { invalid_marker };
u32 index { invalid_marker };
static FlatPtr hops_offset() { return OFFSET_OF(EnvironmentCoordinate, hops); }
static FlatPtr index_offset() { return OFFSET_OF(EnvironmentCoordinate, index); }
bool is_valid() const { return hops != invalid_marker && index != invalid_marker; }
static constexpr u32 invalid_marker = 0xfffffffe;

View file

@ -30,6 +30,8 @@ struct ExecutionContext {
void visit_edges(Cell::Visitor&);
static FlatPtr lexical_environment_offset() { return OFFSET_OF(ExecutionContext, lexical_environment); }
private:
explicit ExecutionContext(MarkedVector<Value> existing_arguments, MarkedVector<Value> existing_local_variables);