Method optimise

libevmasm/Inliner.cpp:238–280

void Inliner::optimise()
{
	std::map<size_t, InlinableBlock> inlinableBlocks = determineInlinableBlocks(m_items);

	if (inlinableBlocks.empty())
		return;

	AssemblyItems newItems;
	for (auto it = m_items.begin(); it != m_items.end(); ++it)
	{
		AssemblyItem const& item = *it;
		if (next(it) != m_items.end())
		{
			AssemblyItem const& nextItem = *next(it);
			if (item.type() == PushTag && nextItem == Instruction::JUMP)
			{
				if (std::optional<size_t> tag = getLocalTag(item))
					if (auto* inlinableBlock = util::valueOrNullptr(inlinableBlocks, *tag))
						if (auto exitItem = shouldInline(*tag, nextItem, *inlinableBlock))
						{
							newItems += inlinableBlock->items | ranges::views::drop_last(1);
							newItems.emplace_back(std::move(*exitItem));

							// We are removing one push tag to the block we inline.
							--inlinableBlock->pushTagCount;
							// We might increase the number of push tags to other blocks.
							for (AssemblyItem const& inlinedItem: inlinableBlock->items)
								if (inlinedItem.type() == PushTag)
									if (std::optional<size_t> duplicatedTag = getLocalTag(inlinedItem))
										if (auto* block = util::valueOrNullptr(inlinableBlocks, *duplicatedTag))
											++block->pushTagCount;

							// Skip the original jump to the inlined tag and continue.
							++it;
							continue;
						}
			}
		}
		newItems.emplace_back(item);
	}

	m_items = std::move(newItems);
}