mirror of
				https://github.com/RGBCube/serenity
				synced 2025-10-31 02:42:44 +00:00 
			
		
		
		
	 4699c81fc1
			
		
	
	
		4699c81fc1
		
	
	
	
	
		
			
			This patch makes IteratorRecord an Object. Although it's not exposed to
author code, this does allow us to store it in a VM register.
Now that we can store it in a VM register, we don't need to convert it
back and forth between IteratorRecord and Object when accessing it from
bytecode.
The big win here is avoiding 3 [[Get]] accesses on every iteration step
of for..of loops. There are also a bunch of smaller efficiencies gained.
20% speed-up on this microbenchmark:
    function go(a) {
        for (const p of a) {
        }
    }
    const a = [];
    a.length = 1_000_000;
    go(a);
		
	
			
		
			
				
	
	
		
			33 lines
		
	
	
	
		
			1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			33 lines
		
	
	
	
		
			1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2021, David Tuin <davidot@serenityos.org>
 | |
|  * Copyright (c) 2022-2023, Linus Groh <linusg@serenityos.org>
 | |
|  *
 | |
|  * SPDX-License-Identifier: BSD-2-Clause
 | |
|  */
 | |
| 
 | |
| #include <LibJS/Runtime/AsyncFromSyncIterator.h>
 | |
| #include <LibJS/Runtime/AsyncFromSyncIteratorPrototype.h>
 | |
| #include <LibJS/Runtime/GlobalObject.h>
 | |
| 
 | |
| namespace JS {
 | |
| 
 | |
| JS_DEFINE_ALLOCATOR(AsyncFromSyncIterator);
 | |
| 
 | |
| NonnullGCPtr<AsyncFromSyncIterator> AsyncFromSyncIterator::create(Realm& realm, NonnullGCPtr<IteratorRecord> sync_iterator_record)
 | |
| {
 | |
|     return realm.heap().allocate<AsyncFromSyncIterator>(realm, realm, sync_iterator_record);
 | |
| }
 | |
| 
 | |
| AsyncFromSyncIterator::AsyncFromSyncIterator(Realm& realm, NonnullGCPtr<IteratorRecord> sync_iterator_record)
 | |
|     : Object(ConstructWithPrototypeTag::Tag, realm.intrinsics().async_from_sync_iterator_prototype())
 | |
|     , m_sync_iterator_record(sync_iterator_record)
 | |
| {
 | |
| }
 | |
| 
 | |
| void AsyncFromSyncIterator::visit_edges(Cell::Visitor& visitor)
 | |
| {
 | |
|     Base::visit_edges(visitor);
 | |
|     visitor.visit(m_sync_iterator_record);
 | |
| }
 | |
| 
 | |
| }
 |