mirror of
https://github.com/fergalmoran/ladybird.git
synced 2025-12-25 19:04:58 +00:00
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.
103 lines
3.9 KiB
C++
103 lines
3.9 KiB
C++
/*
|
|
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Bytecode/PassManager.h>
|
|
|
|
namespace JS::Bytecode::Passes {
|
|
|
|
void GenerateCFG::perform(PassPipelineExecutable& executable)
|
|
{
|
|
started();
|
|
|
|
executable.cfg = HashMap<BasicBlock const*, HashTable<BasicBlock const*>> {};
|
|
executable.inverted_cfg = HashMap<BasicBlock const*, HashTable<BasicBlock const*>> {};
|
|
executable.exported_blocks = HashTable<BasicBlock const*> {};
|
|
Vector<InstructionStreamIterator> iterators;
|
|
Vector<BasicBlock const&> entered_blocks;
|
|
HashTable<BasicBlock const*> seen_blocks;
|
|
|
|
auto enter_label = [&](auto const& label, auto& entering_block, bool exported = false) {
|
|
auto& entry = executable.cfg->ensure(&entering_block);
|
|
entry.set(&label->block());
|
|
auto& inverse_entry = executable.inverted_cfg->ensure(&label->block());
|
|
inverse_entry.set(&entering_block);
|
|
|
|
if (exported)
|
|
executable.exported_blocks->set(&label->block());
|
|
|
|
if (!seen_blocks.contains(&label->block())) {
|
|
seen_blocks.set(&label->block());
|
|
entered_blocks.append(label->block());
|
|
iterators.empend(label->block().instruction_stream());
|
|
}
|
|
};
|
|
|
|
seen_blocks.set(&executable.executable.basic_blocks.first());
|
|
entered_blocks.append(executable.executable.basic_blocks.first());
|
|
iterators.empend(executable.executable.basic_blocks.first().instruction_stream());
|
|
|
|
while (!entered_blocks.is_empty()) {
|
|
if (iterators.last().at_end()) {
|
|
entered_blocks.take_last();
|
|
iterators.take_last();
|
|
continue;
|
|
}
|
|
auto& instruction = *iterators.last();
|
|
++iterators.last();
|
|
if (!instruction.is_terminator())
|
|
continue;
|
|
|
|
auto& current_block = entered_blocks.last();
|
|
|
|
if (instruction.type() == Instruction::Type::Jump) {
|
|
auto& true_target = static_cast<Op::Jump const&>(instruction).true_target();
|
|
enter_label(true_target, current_block);
|
|
continue;
|
|
}
|
|
|
|
if (instruction.type() == Instruction::Type::JumpConditional || instruction.type() == Instruction::Type::JumpNullish) {
|
|
auto& true_target = static_cast<Op::Jump const&>(instruction).true_target();
|
|
enter_label(true_target, current_block);
|
|
auto& false_target = static_cast<Op::Jump const&>(instruction).false_target();
|
|
enter_label(false_target, current_block);
|
|
continue;
|
|
}
|
|
|
|
if (instruction.type() == Instruction::Type::Yield) {
|
|
auto& continuation = static_cast<Op::Yield const&>(instruction).continuation();
|
|
if (continuation.has_value())
|
|
enter_label(continuation, current_block, true);
|
|
continue;
|
|
}
|
|
|
|
if (instruction.type() == Instruction::Type::EnterUnwindContext) {
|
|
auto& entry_point = static_cast<Op::EnterUnwindContext const&>(instruction).entry_point();
|
|
auto& handler_target = static_cast<Op::EnterUnwindContext const&>(instruction).handler_target();
|
|
auto& finalizer_target = static_cast<Op::EnterUnwindContext const&>(instruction).finalizer_target();
|
|
enter_label(&entry_point, current_block);
|
|
if (handler_target.has_value())
|
|
enter_label(handler_target, current_block);
|
|
if (finalizer_target.has_value())
|
|
enter_label(finalizer_target, current_block);
|
|
continue;
|
|
}
|
|
|
|
if (instruction.type() == Instruction::Type::ContinuePendingUnwind) {
|
|
auto& resume_target = static_cast<Op::ContinuePendingUnwind const&>(instruction).resume_target();
|
|
enter_label(&resume_target, current_block);
|
|
continue;
|
|
}
|
|
|
|
// Otherwise, pop the current block off, it doesn't jump anywhere.
|
|
iterators.take_last();
|
|
entered_blocks.take_last();
|
|
}
|
|
|
|
finished();
|
|
}
|
|
|
|
}
|