From a8a8a366299863fe3711880add4c041c437b63cf Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Thu, 19 Jul 2007 02:29:24 +0000 Subject: [PATCH] After a basic block is split into two parts, second part dominates all the blocks dominated by original basic block. And first part dominates second part. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40035 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/BasicBlockUtils.cpp | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp index 520cfeb58b6..0ed3ed6ad57 100644 --- a/lib/Transforms/Utils/BasicBlockUtils.cpp +++ b/lib/Transforms/Utils/BasicBlockUtils.cpp @@ -165,8 +165,21 @@ BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) { if (Loop *L = LI.getLoopFor(Old)) L->addBasicBlockToLoop(New, LI); - if (DominatorTree *DT = P->getAnalysisToUpdate()) - DT->addNewBlock(New, Old); + if (DominatorTree *DT = P->getAnalysisToUpdate()) + { + // Old dominates New. New node domiantes all other nodes dominated by Old. + DomTreeNode *OldNode = DT->getNode(Old); + std::vector Children; + for (DomTreeNode::iterator I = OldNode->begin(), E = OldNode->end(); + I != E; ++I) + Children.push_back(*I); + + DomTreeNode *NewNode = DT->addNewBlock(New,Old); + + for (std::vector::iterator I = Children.begin(), + E = Children.end(); I != E; ++I) + DT->changeImmediateDominator(*I, NewNode); + } if (DominanceFrontier *DF = P->getAnalysisToUpdate()) DF->splitBlock(Old);