RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 08:48:11 +00:00
Code Issues Activity Actions

LibJS: Generate bytecode in basic blocks instead of one big block

Browse source 
This limits the size of each block (currently set to 1K), and gets us
closer to a canonical, more easily analysable bytecode format.
As a result of this, "Labels" are now simply entries to basic blocks.
Since there is no more 'conditional' jump (as all jumps are always
taken), JumpIf{True,False} are unified to JumpConditional, and
JumpIfNullish is renamed to JumpNullish.
Also fixes #7914 as a result of reimplementing the loop logic.
This commit is contained in:
Ali Mohammad Pur 2021-06-09 06:49:58 +04:30 • committed by Andreas Kling
parent d7a25cdb82
commit 01e8f0889a
16 changed files with 392 additions and 174 deletions
Download patch file Download diff file Expand all files Collapse all files

66
Userland/Libraries/LibJS/Bytecode/Block.h
View file

@ -1,66 +0,0 @@
/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Badge.h>
#include <AK/NonnullOwnPtrVector.h>
#include <LibJS/Forward.h>
namespace JS::Bytecode {
class InstructionStreamIterator {
public:
explicit InstructionStreamIterator(ReadonlyBytes bytes)
: m_bytes(bytes)
{
}
size_t offset() const { return m_offset; }
bool at_end() const { return m_offset >= m_bytes.size(); }
void jump(size_t offset)
{
VERIFY(offset <= m_bytes.size());
m_offset = offset;
}
Instruction const& operator*() const { return dereference(); }
void operator++();
private:
Instruction const& dereference() const { return *reinterpret_cast<Instruction const*>(m_bytes.data() + offset()); }
ReadonlyBytes m_bytes;
size_t m_offset { 0 };
};
class Block {
public:
static NonnullOwnPtr<Block> create();
~Block();
void seal();
void dump() const;
ReadonlyBytes instruction_stream() const { return ReadonlyBytes { m_buffer, m_buffer_size }; }
size_t register_count() const { return m_register_count; }
void set_register_count(Badge<Bytecode::Generator>, size_t count) { m_register_count = count; }
void* next_slot() { return m_buffer + m_buffer_size; }
void grow(size_t additional_size);
private:
Block();
size_t m_register_count { 0 };
u8* m_buffer { nullptr };
size_t m_buffer_capacity { 0 };
size_t m_buffer_size { 0 };
};
}