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author | Owen Anderson <resistor@mac.com> | 2007-11-15 05:00:15 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2007-11-15 05:00:15 +0000 |
commit | 44a95e06cc0bb3a2d617fe94235aee92b1951910 (patch) | |
tree | 5a2d9cdc4e6d0d14d0a79480f44b4a1179bde3a4 /lib/Analysis/LoopInfo.cpp | |
parent | b7e6b1ab7029b45f0be81f3026e571f9977dc5c3 (diff) | |
download | external_llvm-44a95e06cc0bb3a2d617fe94235aee92b1951910.zip external_llvm-44a95e06cc0bb3a2d617fe94235aee92b1951910.tar.gz external_llvm-44a95e06cc0bb3a2d617fe94235aee92b1951910.tar.bz2 |
More templatization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44158 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/LoopInfo.cpp')
-rw-r--r-- | lib/Analysis/LoopInfo.cpp | 231 |
1 files changed, 1 insertions, 230 deletions
diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp index 20ca892..559f676 100644 --- a/lib/Analysis/LoopInfo.cpp +++ b/lib/Analysis/LoopInfo.cpp @@ -43,243 +43,14 @@ X("loops", "Natural Loop Construction", true); // bool LoopInfo::runOnFunction(Function &) { releaseMemory(); - Calculate(getAnalysis<DominatorTree>()); // Update + LI->Calculate(getAnalysis<DominatorTree>()); // Update return false; } -void LoopInfo::releaseMemory() { - for (std::vector<Loop*>::iterator I = TopLevelLoops.begin(), - E = TopLevelLoops.end(); I != E; ++I) - delete *I; // Delete all of the loops... - - BBMap.clear(); // Reset internal state of analysis - TopLevelLoops.clear(); -} - -void LoopInfo::Calculate(DominatorTree &DT) { - BasicBlock *RootNode = DT.getRootNode()->getBlock(); - - for (df_iterator<BasicBlock*> NI = df_begin(RootNode), - NE = df_end(RootNode); NI != NE; ++NI) - if (Loop *L = ConsiderForLoop(*NI, DT)) - TopLevelLoops.push_back(L); -} - void LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); AU.addRequired<DominatorTree>(); } -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); - } -} - // Ensure this file gets linked when LoopInfo.h is used. DEFINING_FILE_FOR(LoopInfo) |