diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Utils/LoopSimplify.cpp | 35 |
1 files changed, 18 insertions, 17 deletions
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp index 00ee59d..08bbc09 100644 --- a/lib/Transforms/Utils/LoopSimplify.cpp +++ b/lib/Transforms/Utils/LoopSimplify.cpp @@ -56,6 +56,7 @@ namespace { // We need loop information to identify the loops... AU.addRequired<LoopInfo>(); AU.addRequired<DominatorSet>(); + AU.addRequired<DominatorTree>(); AU.addPreserved<LoopInfo>(); AU.addPreserved<DominatorSet>(); @@ -279,6 +280,9 @@ void LoopSimplify::InsertPreheaderForLoop(Loop *L) { ChangeExitBlock(*ParentLoops, Header, NewBB); DominatorSet &DS = getAnalysis<DominatorSet>(); // Update dominator info + DominatorTree &DT = getAnalysis<DominatorTree>(); + DominatorTree::Node *HeaderDTNode = DT.getNode(Header); + { // The blocks that dominate NewBB are the blocks that dominate Header, // minus Header, plus NewBB. @@ -288,10 +292,20 @@ void LoopSimplify::InsertPreheaderForLoop(Loop *L) { DS.addBasicBlock(NewBB, DomSet); // The newly created basic block dominates all nodes dominated by Header. - for (Function::iterator I = Header->getParent()->begin(), - E = Header->getParent()->end(); I != E; ++I) - if (DS.dominates(Header, I)) - DS.addDominator(I, NewBB); + for (DominatorTree::Node::iterator I = HeaderDTNode->begin(), + E = HeaderDTNode->end(); I != E; ++I) + DS.addDominator((*I)->getBlock(), NewBB); + } + + { // Update the dominator tree information. + // The immediate dominator of the preheader is the immediate dominator of + // the old header. + // + DominatorTree::Node *PHNode = + DT.createNewNode(NewBB, HeaderDTNode->getIDom()); + + // Change the header node so that PNHode is the new immediate dominator + DT.changeImmediateDominator(HeaderDTNode, PHNode); } // Update immediate dominator information if we have it... @@ -303,19 +317,6 @@ void LoopSimplify::InsertPreheaderForLoop(Loop *L) { ID->setImmediateDominator(Header, NewBB); } - // Update DominatorTree information if it is active. - if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) { - // The immediate dominator of the preheader is the immediate dominator of - // the old header. - // - DominatorTree::Node *HeaderNode = DT->getNode(Header); - DominatorTree::Node *PHNode = DT->createNewNode(NewBB, - HeaderNode->getIDom()); - - // Change the header node so that PNHode is the new immediate dominator - DT->changeImmediateDominator(HeaderNode, PHNode); - } - // Update dominance frontier information... if (DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>()) { // The DF(NewBB) is just (DF(Header)-Header), because NewBB dominates |