diff --git a/lib/Transforms/Utils/CriticalEdge.cpp b/lib/Transforms/Utils/CriticalEdge.cpp deleted file mode 100644 index a9f4b611e3f..00000000000 --- a/lib/Transforms/Utils/CriticalEdge.cpp +++ /dev/null @@ -1,93 +0,0 @@ -//===-- CriticalEdge.cpp - Functions to detect and split critical edges ---===// -// -// These functions are here to detect and split critical edges in the CFG. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Transforms/Utils/Local.h" -#include "llvm/iTerminators.h" -#include "llvm/iPHINode.h" -#include "llvm/Analysis/Dominators.h" -#include "llvm/Support/CFG.h" - -// isCriticalEdge - Return true if the specified edge is a critical edge. -// Critical edges are edges from a block with multiple successors to a block -// with multiple predecessors. -// -bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) { - assert(SuccNum < TI->getNumSuccessors() && "Illegal edge specification!"); - if (TI->getNumSuccessors() <= 1) return false; - - const BasicBlock *Dest = TI->getSuccessor(SuccNum); - pred_const_iterator I = pred_begin(Dest), E = pred_end(Dest); - - // If there is more than one predecessor, this is a critical edge... - assert(I != E && "No preds, but we have an edge to the block?"); - ++I; // Skip one edge due to the incoming arc from TI. - return I != E; -} - -// SplitCriticalEdge - Insert a new node node to split the critical edge. This -// will update DominatorSet, ImmediateDominator and DominatorTree information if -// it is available, thus calling this pass will not invalidate either of them. -// -void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P) { - assert(isCriticalEdge(TI, SuccNum) && - "Cannot break a critical edge, if it isn't a critical edge"); - BasicBlock *TIBB = TI->getParent(); - - // Create a new basic block, linking it into the CFG. - BasicBlock *NewBB = new BasicBlock(TIBB->getName()+"_crit_edge"); - BasicBlock *DestBB = TI->getSuccessor(SuccNum); - // Create our unconditional branch... - BranchInst *BI = new BranchInst(DestBB); - NewBB->getInstList().push_back(BI); - - // Branch to the new block, breaking the edge... - TI->setSuccessor(SuccNum, NewBB); - - // Insert the block into the function... right after the block TI lives in. - Function &F = *TIBB->getParent(); - F.getBasicBlockList().insert(TIBB->getNext(), NewBB); - - // If there are any PHI nodes in DestBB, we need to update them so that they - // merge incoming values from NewBB instead of from TIBB. - // - for (BasicBlock::iterator I = DestBB->begin(); - PHINode *PN = dyn_cast(&*I); ++I) { - // We no longer enter through TIBB, now we come in through NewBB. - PN->replaceUsesOfWith(TIBB, NewBB); - } - - // Now if we have a pass object, update analysis information. Currently we - // update DominatorSet and DominatorTree information if it's available. - // - if (P) { - // Should we update DominatorSet information? - if (DominatorSet *DS = P->getAnalysisToUpdate()) { - // The blocks that dominate the new one are the blocks that dominate TIBB - // plus the new block itself. - DominatorSet::DomSetType DomSet = DS->getDominators(TIBB); - DomSet.insert(NewBB); // A block always dominates itself. - DS->addBasicBlock(NewBB, DomSet); - } - - // Should we update ImmdediateDominator information? - if (ImmediateDominators *ID = - P->getAnalysisToUpdate()) { - // TIBB is the new immediate dominator for NewBB. NewBB doesn't dominate - // anything. - ID->addNewBlock(NewBB, TIBB); - } - - // Should we update DominatorTree information? - if (DominatorTree *DT = P->getAnalysisToUpdate()) { - DominatorTree::Node *TINode = DT->getNode(TIBB); - - // The new block is not the immediate dominator for any other nodes, but - // TINode is the immediate dominator for the new node. - // - DT->createNewNode(NewBB, TINode); - } - } -}