/*
* Perform a DFS starting at block `bid', storing the post-order in
* `outVec'.
*/
void RegionDesc::postOrderSort(RegionDesc::BlockId bid,
RegionDesc::BlockIdSet& visited,
RegionDesc::BlockIdVec& outVec) {
if (visited.count(bid)) return;
visited.insert(bid);
if (auto nextRetr = nextRetrans(bid)) {
postOrderSort(nextRetr.value(), visited, outVec);
}
for (auto succ : succs(bid)) {
postOrderSort(succ, visited, outVec);
}
outVec.push_back(bid);
}
/**
* Sort the m_blocks vector in reverse post order. This enforces that
* m_blocks will be a topological order in case the region is acyclic.
* All region arcs are taken into account, including retranslation arcs.
*/
void RegionDesc::sortBlocks() {
RegionDesc::BlockIdSet visited;
RegionDesc::BlockIdVec reverse;
postOrderSort(entry()->id(), visited, reverse);
assertx(m_blocks.size() == reverse.size());
// Update `m_blocks' vector.
m_blocks.clear();
auto size = reverse.size();
for (size_t i = 0; i < size; i++) {
m_blocks.push_back(block(reverse[size - i - 1]));
}
}
/**
* Sort the m_blocks vector in reverse post order. This enforces that
* m_blocks will be a topological order in case the region is acyclic.
* All region arcs are taken into account, including retranslation arcs.
*/
void RegionDesc::sortBlocks() {
RegionDesc::BlockIdSet visited;
RegionDesc::BlockIdVec reverse;
postOrderSort(entry()->id(), visited, reverse);
assertx(m_blocks.size() >= reverse.size());
// Remove unreachable blocks from `m_data'.
for (auto it = m_blocks.begin(); it != m_blocks.end();) {
auto bid = (*it)->id();
if (visited.count(bid) == 0) {
it = deleteBlock(it);
} else {
it++;
}
}
// Update `m_blocks' vector.
m_blocks.clear();
auto size = reverse.size();
for (size_t i = 0; i < size; i++) {
m_blocks.push_back(block(reverse[size - i - 1]));
}
}