5b29974bfa
...minus the EliminateLoads pass, since it was not compatible with the new bytecode format.
68 lines
2.4 KiB
C++
68 lines
2.4 KiB
C++
/*
|
|
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Bytecode/PassManager.h>
|
|
#include <string.h>
|
|
|
|
namespace JS::Bytecode::Passes {
|
|
|
|
void UnifySameBlocks::perform(PassPipelineExecutable& executable)
|
|
{
|
|
started();
|
|
|
|
VERIFY(executable.cfg.has_value());
|
|
VERIFY(executable.inverted_cfg.has_value());
|
|
auto cfg = executable.cfg.release_value();
|
|
auto inverted_cfg = executable.inverted_cfg.release_value();
|
|
|
|
HashMap<BasicBlock const*, BasicBlock const*> equal_blocks;
|
|
|
|
for (size_t i = 0; i < executable.executable.basic_blocks.size(); ++i) {
|
|
auto& block = executable.executable.basic_blocks[i];
|
|
auto block_bytes = block->instruction_stream();
|
|
for (auto& candidate_block : executable.executable.basic_blocks.span().slice(i + 1)) {
|
|
if (equal_blocks.contains(&*candidate_block))
|
|
continue;
|
|
// FIXME: This can probably be relaxed a bit...
|
|
if (candidate_block->size() != block->size())
|
|
continue;
|
|
if (candidate_block->finalizer() != block->finalizer())
|
|
continue;
|
|
if (candidate_block->handler() != block->handler())
|
|
continue;
|
|
|
|
auto candidate_bytes = candidate_block->instruction_stream();
|
|
if (memcmp(candidate_bytes.data(), block_bytes.data(), candidate_block->size()) == 0)
|
|
equal_blocks.set(candidate_block.ptr(), block);
|
|
}
|
|
}
|
|
|
|
auto replace_blocks = [&](auto& match, auto& replacement) {
|
|
Optional<size_t> first_successor_position;
|
|
auto it = executable.executable.basic_blocks.find_if([match](auto& block) { return match == block; });
|
|
VERIFY(!it.is_end());
|
|
executable.executable.basic_blocks.remove(it.index());
|
|
if (!first_successor_position.has_value())
|
|
first_successor_position = it.index();
|
|
|
|
for (auto& block : executable.executable.basic_blocks) {
|
|
InstructionStreamIterator it { block->instruction_stream() };
|
|
while (!it.at_end()) {
|
|
auto& instruction = *it;
|
|
++it;
|
|
const_cast<Instruction&>(instruction).replace_references(*match, replacement);
|
|
}
|
|
}
|
|
return first_successor_position;
|
|
};
|
|
|
|
for (auto& entry : equal_blocks)
|
|
(void)replace_blocks(entry.key, *entry.value);
|
|
|
|
finished();
|
|
}
|
|
|
|
}
|