f6aee2b9e8
Instead of keeping bytecode as a set of disjoint basic blocks on the
malloc heap, bytecode is now a contiguous sequence of bytes(!)
The transformation happens at the end of Bytecode::Generator::generate()
and the only really hairy part is rerouting jump labels.
This required solving a few problems:
- The interpreter execution loop had to change quite a bit, since we
were storing BasicBlock pointers all over the place, and control
transfer was done by redirecting the interpreter's current block.
- Exception handlers & finalizers are now stored per-bytecode-range
in a side table in Executable.
- The interpreter now has a plain program counter instead of a stream
iterator. This actually makes error stack generation a bit nicer
since we just have to deal with a number instead of reaching into
the iterator.
This yields a 25% performance improvement on this microbenchmark:
for (let i = 0; i < 1_000_000; ++i) { }
But basically everything gets faster. :^)
78 lines
2.2 KiB
C++
78 lines
2.2 KiB
C++
/*
|
|
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
|
|
* Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
|
|
* Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Bytecode/Executable.h>
|
|
#include <LibJS/Heap/Heap.h>
|
|
#include <LibJS/Runtime/ExecutionContext.h>
|
|
#include <LibJS/Runtime/FunctionObject.h>
|
|
|
|
namespace JS {
|
|
|
|
NonnullOwnPtr<ExecutionContext> ExecutionContext::create(Heap& heap)
|
|
{
|
|
return adopt_own(*new ExecutionContext(heap));
|
|
}
|
|
|
|
ExecutionContext::ExecutionContext(Heap& heap)
|
|
: m_heap(heap)
|
|
{
|
|
}
|
|
|
|
ExecutionContext::~ExecutionContext()
|
|
{
|
|
}
|
|
|
|
NonnullOwnPtr<ExecutionContext> ExecutionContext::copy() const
|
|
{
|
|
auto copy = create(m_heap);
|
|
copy->function = function;
|
|
copy->realm = realm;
|
|
copy->script_or_module = script_or_module;
|
|
copy->lexical_environment = lexical_environment;
|
|
copy->variable_environment = variable_environment;
|
|
copy->private_environment = private_environment;
|
|
copy->program_counter = program_counter;
|
|
copy->function_name = function_name;
|
|
copy->this_value = this_value;
|
|
copy->is_strict_mode = is_strict_mode;
|
|
copy->executable = executable;
|
|
copy->arguments = arguments;
|
|
copy->locals = locals;
|
|
copy->registers = registers;
|
|
copy->unwind_contexts = unwind_contexts;
|
|
copy->saved_lexical_environments = saved_lexical_environments;
|
|
copy->previously_scheduled_jumps = previously_scheduled_jumps;
|
|
return copy;
|
|
}
|
|
|
|
void ExecutionContext::visit_edges(Cell::Visitor& visitor)
|
|
{
|
|
visitor.visit(function);
|
|
visitor.visit(realm);
|
|
visitor.visit(variable_environment);
|
|
visitor.visit(lexical_environment);
|
|
visitor.visit(private_environment);
|
|
visitor.visit(context_owner);
|
|
visitor.visit(this_value);
|
|
visitor.visit(executable);
|
|
visitor.visit(function_name);
|
|
visitor.visit(arguments);
|
|
visitor.visit(locals);
|
|
visitor.visit(registers);
|
|
for (auto& context : unwind_contexts) {
|
|
visitor.visit(context.lexical_environment);
|
|
}
|
|
visitor.visit(saved_lexical_environments);
|
|
script_or_module.visit(
|
|
[](Empty) {},
|
|
[&](auto& script_or_module) {
|
|
visitor.visit(script_or_module);
|
|
});
|
|
}
|
|
|
|
}
|