void InvalidateWithChildren(Block *New) { // TODO: rename New
BlockList ToInvalidate; // Being in the list means you need to be invalidated
ToInvalidate.push_back(New);
while (ToInvalidate.size() > 0) {
Block *Invalidatee = ToInvalidate.front();
ToInvalidate.pop_front();
Block *Owner = Ownership[Invalidatee];
if (IndependentGroups.find(Owner) != IndependentGroups.end()) { // Owner may have been invalidated, do not add to IndependentGroups!
IndependentGroups[Owner].erase(Invalidatee);
}
if (Ownership[Invalidatee]) { // may have been seen before and invalidated already
Ownership[Invalidatee] = NULL;
for (BlockBranchMap::iterator iter = Invalidatee->BranchesOut.begin(); iter != Invalidatee->BranchesOut.end(); iter++) {
Block *Target = iter->first;
BlockBlockMap::iterator Known = Ownership.find(Target);
if (Known != Ownership.end()) {
Block *TargetOwner = Known->second;
if (TargetOwner) {
ToInvalidate.push_back(Target);
}
}
}
}
}
}
DomChildren findDomChildren(const BlockList& blocks) {
IdomVector idom = findDominators(blocks);
DomChildren children(blocks.size(), BlockList());
for (Block* block : blocks) {
int idom_id = idom[block->postId()];
if (idom_id != -1) children[idom_id].push_back(block);
}
return children;
}
void Line::moveToNextPage(BlockList& floats, double minX, double maxX,
const WTextRenderer& renderer)
{
for (unsigned i = 0; i < blocks_.size(); ++i) {
Block *b = blocks_[i];
if (b->isFloat())
Utils::erase(floats, b);
}
PageState ps;
ps.floats = floats;
ps.page = page_;
Block::clearFloats(ps);
page_ = ps.page;
floats = ps.floats;
double oldY = y_;
y_ = 0;
x_ = minX;
++page_;
BlockList blocks = blocks_;
blocks_.clear();
Range rangeX(x_, maxX);
Block::adjustAvailableWidth(y_, page_, floats, rangeX);
x_ = rangeX.start;
maxX = rangeX.end;
for (unsigned i = 0; i < blocks.size(); ++i) {
Block *b = blocks[i];
if (b->isFloat()) {
b->layoutFloat(y_, page_, floats, x_, height_, minX, maxX,
false, renderer);
reflow(b);
} else {
for (unsigned j = 0; j < b->inlineLayout.size(); ++j) {
InlineBox& ib = b->inlineLayout[j];
if (ib.y == oldY && ib.page == page_ - 1) {
if (ib.x != LEFT_MARGIN_X) {
ib.x = x_;
x_ += ib.width;
}
ib.page = page_;
ib.y = y_;
}
}
}
blocks_.push_back(b);
}
}
BlockList rpoSortCfg(const IRUnit& unit) {
BlockList blocks;
blocks.reserve(unit.numBlocks());
postorderWalk(unit,
[&](Block* block) {
blocks.push_back(block);
});
std::reverse(blocks.begin(), blocks.end());
assert(blocks.size() <= unit.numBlocks());
return blocks;
}
void FindLive(Block *Root) {
BlockList ToInvestigate;
ToInvestigate.push_back(Root);
while (ToInvestigate.size() > 0) {
Block *Curr = ToInvestigate.front();
ToInvestigate.pop_front();
if (Live.find(Curr) != Live.end()) continue;
Live.insert(Curr);
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
ToInvestigate.push_back(iter->first);
}
}
}
/*
* Find the immediate dominator of each block using Cooper, Harvey, and
* Kennedy's "A Simple, Fast Dominance Algorithm", returned as a vector
* of postorder ids, indexed by postorder id.
*/
IdomVector findDominators(const BlockList& blocks) {
assert(isRPOSorted(blocks));
// Calculate immediate dominators with the iterative two-finger algorithm.
// When it terminates, idom[post-id] will contain the post-id of the
// immediate dominator of each block. idom[start] will be -1. This is
// the general algorithm but it will only loop twice for loop-free graphs.
auto const num_blocks = blocks.size();
IdomVector idom(num_blocks, -1);
auto start = blocks.begin();
int start_id = (*start)->postId();
idom[start_id] = start_id;
start++;
for (bool changed = true; changed; ) {
changed = false;
// for each block after start, in reverse postorder
for (auto it = start; it != blocks.end(); it++) {
Block* block = *it;
int b = block->postId();
// new_idom = any already-processed predecessor
auto edge_it = block->preds().begin();
int new_idom = edge_it->from()->postId();
while (idom[new_idom] == -1) new_idom = (++edge_it)->from()->postId();
// for all other already-processed predecessors p of b
for (auto& edge : block->preds()) {
auto p = edge.from()->postId();
if (p != new_idom && idom[p] != -1) {
// find earliest common predecessor of p and new_idom
// (higher postIds are earlier in flow and in dom-tree).
int b1 = p, b2 = new_idom;
do {
while (b1 < b2) b1 = idom[b1];
while (b2 < b1) b2 = idom[b2];
} while (b1 != b2);
new_idom = b1;
}
}
if (idom[b] != new_idom) {
idom[b] = new_idom;
changed = true;
}
}
}
idom[start_id] = -1; // start has no idom.
return idom;
}
BlockList rpoSortCfg(IRTrace* trace, const IRFactory& factory) {
assert(trace->isMain());
BlockList blocks;
blocks.reserve(factory.numBlocks());
unsigned next_id = 0;
postorderWalk(
[&](Block* block) {
block->setPostId(next_id++);
blocks.push_back(block);
},
factory.numBlocks(),
trace->front()
);
std::reverse(blocks.begin(), blocks.end());
assert(blocks.size() <= factory.numBlocks());
assert(next_id <= factory.numBlocks());
return blocks;
}
// For each entry, find the independent group reachable by it. The independent group is
// the entry itself, plus all the blocks it can reach that cannot be directly reached by another entry. Note that we
// ignore directly reaching the entry itself by another entry.
void FindIndependentGroups(BlockSet &Blocks, BlockSet &Entries, BlockBlockSetMap& IndependentGroups) {
typedef std::map<Block*, Block*> BlockBlockMap;
struct HelperClass {
BlockBlockSetMap& IndependentGroups;
BlockBlockMap Ownership; // For each block, which entry it belongs to. We have reached it from there.
HelperClass(BlockBlockSetMap& IndependentGroupsInit) : IndependentGroups(IndependentGroupsInit) {}
void InvalidateWithChildren(Block *New) { // TODO: rename New
BlockList ToInvalidate; // Being in the list means you need to be invalidated
ToInvalidate.push_back(New);
while (ToInvalidate.size() > 0) {
Block *Invalidatee = ToInvalidate.front();
ToInvalidate.pop_front();
Block *Owner = Ownership[Invalidatee];
if (IndependentGroups.find(Owner) != IndependentGroups.end()) { // Owner may have been invalidated, do not add to IndependentGroups!
IndependentGroups[Owner].erase(Invalidatee);
}
if (Ownership[Invalidatee]) { // may have been seen before and invalidated already
Ownership[Invalidatee] = NULL;
for (BlockBranchMap::iterator iter = Invalidatee->BranchesOut.begin(); iter != Invalidatee->BranchesOut.end(); iter++) {
Block *Target = iter->first;
BlockBlockMap::iterator Known = Ownership.find(Target);
if (Known != Ownership.end()) {
Block *TargetOwner = Known->second;
if (TargetOwner) {
ToInvalidate.push_back(Target);
}
}
}
}
}
}
};
HelperClass Helper(IndependentGroups);
// We flow out from each of the entries, simultaneously.
// When we reach a new block, we add it as belonging to the one we got to it from.
// If we reach a new block that is already marked as belonging to someone, it is reachable by
// two entries and is not valid for any of them. Remove it and all it can reach that have been
// visited.
BlockList Queue; // Being in the queue means we just added this item, and we need to add its children
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
Block *Entry = *iter;
Helper.Ownership[Entry] = Entry;
IndependentGroups[Entry].insert(Entry);
Queue.push_back(Entry);
}
while (Queue.size() > 0) {
Block *Curr = Queue.front();
Queue.pop_front();
Block *Owner = Helper.Ownership[Curr]; // Curr must be in the ownership map if we are in the queue
if (!Owner) continue; // we have been invalidated meanwhile after being reached from two entries
// Add all children
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
Block *New = iter->first;
BlockBlockMap::iterator Known = Helper.Ownership.find(New);
if (Known == Helper.Ownership.end()) {
// New node. Add it, and put it in the queue
Helper.Ownership[New] = Owner;
IndependentGroups[Owner].insert(New);
Queue.push_back(New);
continue;
}
Block *NewOwner = Known->second;
if (!NewOwner) continue; // We reached an invalidated node
if (NewOwner != Owner) {
// Invalidate this and all reachable that we have seen - we reached this from two locations
Helper.InvalidateWithChildren(New);
}
// otherwise, we have the same owner, so do nothing
}
}
// Having processed all the interesting blocks, we remain with just one potential issue:
// If a->b, and a was invalidated, but then b was later reached by someone else, we must
// invalidate b. To check for this, we go over all elements in the independent groups,
// if an element has a parent which does *not* have the same owner, we must remove it
// and all its children.
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
BlockSet &CurrGroup = IndependentGroups[*iter];
BlockList ToInvalidate;
for (BlockSet::iterator iter = CurrGroup.begin(); iter != CurrGroup.end(); iter++) {
Block *Child = *iter;
for (BlockBranchMap::iterator iter = Child->BranchesIn.begin(); iter != Child->BranchesIn.end(); iter++) {
Block *Parent = iter->first;
if (Helper.Ownership[Parent] != Helper.Ownership[Child]) {
ToInvalidate.push_back(Child);
}
}
}
while (ToInvalidate.size() > 0) {
Block *Invalidatee = ToInvalidate.front();
ToInvalidate.pop_front();
Helper.InvalidateWithChildren(Invalidatee);
}
}
// Remove empty groups
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
if (IndependentGroups[*iter].size() == 0) {
IndependentGroups.erase(*iter);
}
}
#if DEBUG
PrintDebug("Investigated independent groups:\n");
for (BlockBlockSetMap::iterator iter = IndependentGroups.begin(); iter != IndependentGroups.end(); iter++) {
DebugDump(iter->second, " group: ");
}
#endif
}
unsigned int NBlocks(void) const { return blocks.size(); }