mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-09-20 01:37:39 +03:00
1414c7b049
This commit adds a bunch of passes, the most interesting of which is a pass that merges blocks together, and a pass that places blocks that flow into each other next to each other, and a very simply pass that removes duplicate basic blocks. Note that this does not remove the jump at the end of each block in that pass to avoid scope creep in the passes.
74 lines
2.2 KiB
C++
74 lines
2.2 KiB
C++
/*
|
|
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/String.h>
|
|
#include <LibJS/Bytecode/BasicBlock.h>
|
|
#include <LibJS/Bytecode/Op.h>
|
|
#include <sys/mman.h>
|
|
|
|
namespace JS::Bytecode {
|
|
|
|
NonnullOwnPtr<BasicBlock> BasicBlock::create(String name, size_t size)
|
|
{
|
|
return adopt_own(*new BasicBlock(move(name), max(size, static_cast<size_t>(4 * KiB))));
|
|
}
|
|
|
|
BasicBlock::BasicBlock(String name, size_t size)
|
|
: m_name(move(name))
|
|
{
|
|
// FIXME: This is not the smartest solution ever. Find something cleverer!
|
|
// The main issue we're working around here is that we don't want pointers into the bytecode stream to become invalidated
|
|
// during code generation due to dynamic buffer resizing. Otherwise we could just use a Vector.
|
|
m_buffer_capacity = size;
|
|
m_buffer = (u8*)mmap(nullptr, m_buffer_capacity, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
|
|
VERIFY(m_buffer != MAP_FAILED);
|
|
}
|
|
|
|
BasicBlock::~BasicBlock()
|
|
{
|
|
Bytecode::InstructionStreamIterator it(instruction_stream());
|
|
while (!it.at_end()) {
|
|
auto& to_destroy = (*it);
|
|
++it;
|
|
Instruction::destroy(const_cast<Instruction&>(to_destroy));
|
|
}
|
|
|
|
munmap(m_buffer, m_buffer_capacity);
|
|
}
|
|
|
|
void BasicBlock::seal()
|
|
{
|
|
// FIXME: mprotect the instruction stream as PROT_READ
|
|
// This is currently not possible because instructions can have destructors (that clean up strings)
|
|
// Instructions should instead be destructor-less and refer to strings in a string table on the Bytecode::Block.
|
|
// It also doesn't work because instructions that have String members use RefPtr internally which must be in writable memory.
|
|
}
|
|
|
|
void BasicBlock::dump(Bytecode::Executable const& executable) const
|
|
{
|
|
Bytecode::InstructionStreamIterator it(instruction_stream());
|
|
if (!m_name.is_empty())
|
|
warnln("{}:", m_name);
|
|
while (!it.at_end()) {
|
|
warnln("[{:4x}] {}", it.offset(), (*it).to_string(executable));
|
|
++it;
|
|
}
|
|
}
|
|
|
|
void BasicBlock::grow(size_t additional_size)
|
|
{
|
|
m_buffer_size += additional_size;
|
|
VERIFY(m_buffer_size <= m_buffer_capacity);
|
|
}
|
|
|
|
void InstructionStreamIterator::operator++()
|
|
{
|
|
VERIFY(!at_end());
|
|
m_offset += dereference().length();
|
|
}
|
|
|
|
}
|