diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp | 56 |
1 files changed, 10 insertions, 46 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp b/contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp index f75ffe6..616b066 100644 --- a/contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp +++ b/contrib/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp @@ -11,8 +11,7 @@ // inserting a dummy basic block. This pass may be "required" by passes that // cannot deal with critical edges. For this usage, the structure type is // forward declared. This pass obviously invalidates the CFG, but can update -// forward dominator (set, immediate dominators, tree, and frontier) -// information. +// dominator trees. // //===----------------------------------------------------------------------===// @@ -36,13 +35,14 @@ STATISTIC(NumBroken, "Number of blocks inserted"); namespace { struct BreakCriticalEdges : public FunctionPass { static char ID; // Pass identification, replacement for typeid - BreakCriticalEdges() : FunctionPass(ID) {} + BreakCriticalEdges() : FunctionPass(ID) { + initializeBreakCriticalEdgesPass(*PassRegistry::getPassRegistry()); + } virtual bool runOnFunction(Function &F); virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addPreserved<DominatorTree>(); - AU.addPreserved<DominanceFrontier>(); AU.addPreserved<LoopInfo>(); AU.addPreserved<ProfileInfo>(); @@ -54,7 +54,7 @@ namespace { char BreakCriticalEdges::ID = 0; INITIALIZE_PASS(BreakCriticalEdges, "break-crit-edges", - "Break critical edges in CFG", false, false); + "Break critical edges in CFG", false, false) // Publically exposed interface to pass... char &llvm::BreakCriticalEdgesID = BreakCriticalEdges::ID; @@ -150,10 +150,9 @@ static void CreatePHIsForSplitLoopExit(SmallVectorImpl<BasicBlock *> &Preds, } /// SplitCriticalEdge - If this edge is a critical edge, insert a new node to -/// split the critical edge. This will update DominatorTree and -/// DominatorFrontier information if it is available, thus calling this pass -/// will not invalidate either of them. This returns the new block if the edge -/// was split, null otherwise. +/// split the critical edge. This will update DominatorTree information if it +/// is available, thus calling this pass will not invalidate either of them. +/// This returns the new block if the edge was split, null otherwise. /// /// If MergeIdenticalEdges is true (not the default), *all* edges from TI to the /// specified successor will be merged into the same critical edge block. @@ -255,12 +254,11 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, if (P == 0) return NewBB; DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>(); - DominanceFrontier *DF = P->getAnalysisIfAvailable<DominanceFrontier>(); LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>(); ProfileInfo *PI = P->getAnalysisIfAvailable<ProfileInfo>(); // If we have nothing to update, just return. - if (DT == 0 && DF == 0 && LI == 0 && PI == 0) + if (DT == 0 && LI == 0 && PI == 0) return NewBB; // Now update analysis information. Since the only predecessor of NewBB is @@ -281,7 +279,7 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, I != E; ++I) { BasicBlock *P = *I; if (P != NewBB) - OtherPreds.push_back(P); + OtherPreds.push_back(P); } } @@ -318,40 +316,6 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, } } - // Should we update DominanceFrontier information? - if (DF) { - // If NewBBDominatesDestBB hasn't been computed yet, do so with DF. - if (!OtherPreds.empty()) { - // FIXME: IMPLEMENT THIS! - llvm_unreachable("Requiring domfrontiers but not idom/domtree/domset." - " not implemented yet!"); - } - - // Since the new block is dominated by its only predecessor TIBB, - // it cannot be in any block's dominance frontier. If NewBB dominates - // DestBB, its dominance frontier is the same as DestBB's, otherwise it is - // just {DestBB}. - DominanceFrontier::DomSetType NewDFSet; - if (NewBBDominatesDestBB) { - DominanceFrontier::iterator I = DF->find(DestBB); - if (I != DF->end()) { - DF->addBasicBlock(NewBB, I->second); - - if (I->second.count(DestBB)) { - // However NewBB's frontier does not include DestBB. - DominanceFrontier::iterator NF = DF->find(NewBB); - DF->removeFromFrontier(NF, DestBB); - } - } - else - DF->addBasicBlock(NewBB, DominanceFrontier::DomSetType()); - } else { - DominanceFrontier::DomSetType NewDFSet; - NewDFSet.insert(DestBB); - DF->addBasicBlock(NewBB, NewDFSet); - } - } - // Update LoopInfo if it is around. if (LI) { if (Loop *TIL = LI->getLoopFor(TIBB)) { |