From 10ff10ffc12c65ac741ee537b6f93c567510a5cc Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Wed, 17 Oct 2007 02:03:17 +0000 Subject: Move splitBlock into DomTreeBase from DomTree. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43059 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/VMCore/Dominators.cpp | 82 ----------------------------------------------- 1 file changed, 82 deletions(-) (limited to 'lib/VMCore/Dominators.cpp') diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp index a9900fe..b909a00 100644 --- a/lib/VMCore/Dominators.cpp +++ b/lib/VMCore/Dominators.cpp @@ -56,88 +56,6 @@ char DominatorTree::ID = 0; static RegisterPass E("domtree", "Dominator Tree Construction", true); -// NewBB is split and now it has one successor. Update dominator tree to -// reflect this change. -void DominatorTree::splitBlock(BasicBlock *NewBB) { - assert(NewBB->getTerminator()->getNumSuccessors() == 1 - && "NewBB should have a single successor!"); - BasicBlock *NewBBSucc = NewBB->getTerminator()->getSuccessor(0); - - std::vector PredBlocks; - for (pred_iterator PI = pred_begin(NewBB), PE = pred_end(NewBB); - PI != PE; ++PI) - PredBlocks.push_back(*PI); - - assert(!PredBlocks.empty() && "No predblocks??"); - - // The newly inserted basic block will dominate existing basic blocks iff the - // PredBlocks dominate all of the non-pred blocks. If all predblocks dominate - // the non-pred blocks, then they all must be the same block! - // - bool NewBBDominatesNewBBSucc = true; - { - BasicBlock *OnePred = PredBlocks[0]; - unsigned i = 1, e = PredBlocks.size(); - for (i = 1; !isReachableFromEntry(OnePred); ++i) { - assert(i != e && "Didn't find reachable pred?"); - OnePred = PredBlocks[i]; - } - - for (; i != e; ++i) - if (PredBlocks[i] != OnePred && isReachableFromEntry(OnePred)) { - NewBBDominatesNewBBSucc = false; - break; - } - - if (NewBBDominatesNewBBSucc) - for (pred_iterator PI = pred_begin(NewBBSucc), E = pred_end(NewBBSucc); - PI != E; ++PI) - if (*PI != NewBB && !dominates(NewBBSucc, *PI)) { - NewBBDominatesNewBBSucc = false; - break; - } - } - - // The other scenario where the new block can dominate its successors are when - // all predecessors of NewBBSucc that are not NewBB are dominated by NewBBSucc - // already. - if (!NewBBDominatesNewBBSucc) { - NewBBDominatesNewBBSucc = true; - for (pred_iterator PI = pred_begin(NewBBSucc), E = pred_end(NewBBSucc); - PI != E; ++PI) - if (*PI != NewBB && !dominates(NewBBSucc, *PI)) { - NewBBDominatesNewBBSucc = false; - break; - } - } - - // Find NewBB's immediate dominator and create new dominator tree node for - // NewBB. - BasicBlock *NewBBIDom = 0; - unsigned i = 0; - for (i = 0; i < PredBlocks.size(); ++i) - if (isReachableFromEntry(PredBlocks[i])) { - NewBBIDom = PredBlocks[i]; - break; - } - assert(i != PredBlocks.size() && "No reachable preds?"); - for (i = i + 1; i < PredBlocks.size(); ++i) { - if (isReachableFromEntry(PredBlocks[i])) - NewBBIDom = findNearestCommonDominator(NewBBIDom, PredBlocks[i]); - } - assert(NewBBIDom && "No immediate dominator found??"); - - // Create the new dominator tree node... and set the idom of NewBB. - DomTreeNode *NewBBNode = addNewBlock(NewBB, NewBBIDom); - - // If NewBB strictly dominates other blocks, then it is now the immediate - // dominator of NewBBSucc. Update the dominator tree as appropriate. - if (NewBBDominatesNewBBSucc) { - DomTreeNode *NewBBSuccNode = getNode(NewBBSucc); - changeImmediateDominator(NewBBSuccNode, NewBBNode); - } -} - bool DominatorTree::runOnFunction(Function &F) { reset(); // Reset from the last time we were run... -- cgit v1.1