-void LoopInfo::print(std::ostream &OS, const Module* ) const {
- for (unsigned i = 0; i < TopLevelLoops.size(); ++i)
- TopLevelLoops[i]->print(OS);
-#if 0
- for (std::map<BasicBlock*, Loop*>::const_iterator I = BBMap.begin(),
- E = BBMap.end(); I != E; ++I)
- OS << "BB '" << I->first->getName() << "' level = "
- << I->second->getLoopDepth() << "\n";
-#endif
-}
-
-static bool isNotAlreadyContainedIn(Loop *SubLoop, Loop *ParentLoop) {
- if (SubLoop == 0) return true;
- if (SubLoop == ParentLoop) return false;
- return isNotAlreadyContainedIn(SubLoop->getParentLoop(), ParentLoop);
-}
-
-Loop *LoopInfo::ConsiderForLoop(BasicBlock *BB, DominatorTree &DT) {
- if (BBMap.find(BB) != BBMap.end()) return 0; // Haven't processed this node?
-
- std::vector<BasicBlock *> TodoStack;
-
- // Scan the predecessors of BB, checking to see if BB dominates any of
- // them. This identifies backedges which target this node...
- for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I)
- if (DT.dominates(BB, *I)) // If BB dominates it's predecessor...
- TodoStack.push_back(*I);
-
- if (TodoStack.empty()) return 0; // No backedges to this block...
-
- // Create a new loop to represent this basic block...
- Loop *L = new Loop(BB);
- BBMap[BB] = L;
-
- BasicBlock *EntryBlock = &BB->getParent()->getEntryBlock();
-
- while (!TodoStack.empty()) { // Process all the nodes in the loop
- BasicBlock *X = TodoStack.back();
- TodoStack.pop_back();
-
- if (!L->contains(X) && // As of yet unprocessed??
- DT.dominates(EntryBlock, X)) { // X is reachable from entry block?
- // Check to see if this block already belongs to a loop. If this occurs
- // then we have a case where a loop that is supposed to be a child of the
- // current loop was processed before the current loop. When this occurs,
- // this child loop gets added to a part of the current loop, making it a
- // sibling to the current loop. We have to reparent this loop.
- if (Loop *SubLoop = const_cast<Loop*>(getLoopFor(X)))
- if (SubLoop->getHeader() == X && isNotAlreadyContainedIn(SubLoop, L)) {
- // Remove the subloop from it's current parent...
- assert(SubLoop->ParentLoop && SubLoop->ParentLoop != L);
- Loop *SLP = SubLoop->ParentLoop; // SubLoopParent
- std::vector<Loop*>::iterator I =
- std::find(SLP->SubLoops.begin(), SLP->SubLoops.end(), SubLoop);
- assert(I != SLP->SubLoops.end() && "SubLoop not a child of parent?");
- SLP->SubLoops.erase(I); // Remove from parent...
-
- // Add the subloop to THIS loop...
- SubLoop->ParentLoop = L;
- L->SubLoops.push_back(SubLoop);
- }
-
- // Normal case, add the block to our loop...
- L->Blocks.push_back(X);
-
- // Add all of the predecessors of X to the end of the work stack...
- TodoStack.insert(TodoStack.end(), pred_begin(X), pred_end(X));
- }
- }
-
- // If there are any loops nested within this loop, create them now!
- for (std::vector<BasicBlock*>::iterator I = L->Blocks.begin(),
- E = L->Blocks.end(); I != E; ++I)
- if (Loop *NewLoop = ConsiderForLoop(*I, DT)) {
- L->SubLoops.push_back(NewLoop);
- NewLoop->ParentLoop = L;
- }
-
- // Add the basic blocks that comprise this loop to the BBMap so that this
- // loop can be found for them.
- //
- for (std::vector<BasicBlock*>::iterator I = L->Blocks.begin(),
- E = L->Blocks.end(); I != E; ++I) {
- std::map<BasicBlock*, Loop*>::iterator BBMI = BBMap.lower_bound(*I);
- if (BBMI == BBMap.end() || BBMI->first != *I) // Not in map yet...
- BBMap.insert(BBMI, std::make_pair(*I, L)); // Must be at this level
- }
-
- // Now that we have a list of all of the child loops of this loop, check to
- // see if any of them should actually be nested inside of each other. We can
- // accidentally pull loops our of their parents, so we must make sure to
- // organize the loop nests correctly now.
- {
- std::map<BasicBlock*, Loop*> ContainingLoops;
- for (unsigned i = 0; i != L->SubLoops.size(); ++i) {
- Loop *Child = L->SubLoops[i];
- assert(Child->getParentLoop() == L && "Not proper child loop?");
-
- if (Loop *ContainingLoop = ContainingLoops[Child->getHeader()]) {
- // If there is already a loop which contains this loop, move this loop
- // into the containing loop.
- MoveSiblingLoopInto(Child, ContainingLoop);
- --i; // The loop got removed from the SubLoops list.
- } else {
- // This is currently considered to be a top-level loop. Check to see if
- // any of the contained blocks are loop headers for subloops we have
- // already processed.
- for (unsigned b = 0, e = Child->Blocks.size(); b != e; ++b) {
- Loop *&BlockLoop = ContainingLoops[Child->Blocks[b]];
- if (BlockLoop == 0) { // Child block not processed yet...
- BlockLoop = Child;
- } else if (BlockLoop != Child) {
- Loop *SubLoop = BlockLoop;
- // Reparent all of the blocks which used to belong to BlockLoops
- for (unsigned j = 0, e = SubLoop->Blocks.size(); j != e; ++j)
- ContainingLoops[SubLoop->Blocks[j]] = Child;
-
- // There is already a loop which contains this block, that means
- // that we should reparent the loop which the block is currently
- // considered to belong to to be a child of this loop.
- MoveSiblingLoopInto(SubLoop, Child);
- --i; // We just shrunk the SubLoops list.
- }
- }
- }
- }
- }
-
- return L;
-}
-
-/// MoveSiblingLoopInto - This method moves the NewChild loop to live inside of
-/// the NewParent Loop, instead of being a sibling of it.
-void LoopInfo::MoveSiblingLoopInto(Loop *NewChild, Loop *NewParent) {
- Loop *OldParent = NewChild->getParentLoop();
- assert(OldParent && OldParent == NewParent->getParentLoop() &&
- NewChild != NewParent && "Not sibling loops!");
-
- // Remove NewChild from being a child of OldParent
- std::vector<Loop*>::iterator I =
- std::find(OldParent->SubLoops.begin(), OldParent->SubLoops.end(), NewChild);
- assert(I != OldParent->SubLoops.end() && "Parent fields incorrect??");
- OldParent->SubLoops.erase(I); // Remove from parent's subloops list
- NewChild->ParentLoop = 0;
-
- InsertLoopInto(NewChild, NewParent);
-}
-
-/// InsertLoopInto - This inserts loop L into the specified parent loop. If the
-/// parent loop contains a loop which should contain L, the loop gets inserted
-/// into L instead.
-void LoopInfo::InsertLoopInto(Loop *L, Loop *Parent) {
- BasicBlock *LHeader = L->getHeader();
- assert(Parent->contains(LHeader) && "This loop should not be inserted here!");
-
- // Check to see if it belongs in a child loop...
- for (unsigned i = 0, e = Parent->SubLoops.size(); i != e; ++i)
- if (Parent->SubLoops[i]->contains(LHeader)) {
- InsertLoopInto(L, Parent->SubLoops[i]);
- return;
- }
-
- // If not, insert it here!
- Parent->SubLoops.push_back(L);
- L->ParentLoop = Parent;
-}
-
-/// changeLoopFor - Change the top-level loop that contains BB to the
-/// specified loop. This should be used by transformations that restructure
-/// the loop hierarchy tree.
-void LoopInfo::changeLoopFor(BasicBlock *BB, Loop *L) {
- Loop *&OldLoop = BBMap[BB];
- assert(OldLoop && "Block not in a loop yet!");
- OldLoop = L;
-}
-
-/// changeTopLevelLoop - Replace the specified loop in the top-level loops
-/// list with the indicated loop.
-void LoopInfo::changeTopLevelLoop(Loop *OldLoop, Loop *NewLoop) {
- std::vector<Loop*>::iterator I = std::find(TopLevelLoops.begin(),
- TopLevelLoops.end(), OldLoop);
- assert(I != TopLevelLoops.end() && "Old loop not at top level!");
- *I = NewLoop;
- assert(NewLoop->ParentLoop == 0 && OldLoop->ParentLoop == 0 &&
- "Loops already embedded into a subloop!");
-}
-
-/// removeLoop - This removes the specified top-level loop from this loop info
-/// object. The loop is not deleted, as it will presumably be inserted into
-/// another loop.
-Loop *LoopInfo::removeLoop(iterator I) {
- assert(I != end() && "Cannot remove end iterator!");
- Loop *L = *I;
- assert(L->getParentLoop() == 0 && "Not a top-level loop!");
- TopLevelLoops.erase(TopLevelLoops.begin() + (I-begin()));
- return L;
-}
-
-/// removeBlock - This method completely removes BB from all data structures,
-/// including all of the Loop objects it is nested in and our mapping from
-/// BasicBlocks to loops.
-void LoopInfo::removeBlock(BasicBlock *BB) {
- std::map<BasicBlock *, Loop*>::iterator I = BBMap.find(BB);
- if (I != BBMap.end()) {
- for (Loop *L = I->second; L; L = L->getParentLoop())
- L->removeBlockFromLoop(BB);
-
- BBMap.erase(I);
- }
-}
-
projects / oota-llvm.git / blobdiff