X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FBreakCriticalEdges.cpp;h=616b066b5ab140543399a0cd1f5049a7e0790ef6;hb=2bc2a08b1bf6b5dcbfa515acc85999d6f884ec1a;hp=d1b0e86f49861e27648c34d9eec47fc068fbb338;hpb=7556cf541bd91247127f1552fbd36c979777f70c;p=oota-llvm.git diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp index d1b0e86f498..616b066b5ab 100644 --- a/lib/Transforms/Utils/BreakCriticalEdges.cpp +++ b/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(); - AU.addPreserved(); AU.addPreserved(); AU.addPreserved(); @@ -53,11 +53,11 @@ namespace { } char BreakCriticalEdges::ID = 0; -static RegisterPass -X("break-crit-edges", "Break critical edges in CFG"); +INITIALIZE_PASS(BreakCriticalEdges, "break-crit-edges", + "Break critical edges in CFG", false, false) // Publically exposed interface to pass... -const PassInfo *const llvm::BreakCriticalEdgesID = &X; +char &llvm::BreakCriticalEdgesID = BreakCriticalEdges::ID; FunctionPass *llvm::createBreakCriticalEdgesPass() { return new BreakCriticalEdges(); } @@ -106,11 +106,12 @@ bool llvm::isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, // If AllowIdenticalEdges is true, then we allow this edge to be considered // non-critical iff all preds come from TI's block. while (I != E) { - if (*I != FirstPred) + const BasicBlock *P = *I; + if (P != FirstPred) return true; // Note: leave this as is until no one ever compiles with either gcc 4.0.1 // or Xcode 2. This seems to work around the pred_iterator assert in PR 2207 - E = pred_end(*I); + E = pred_end(P); ++I; } return false; @@ -149,10 +150,9 @@ static void CreatePHIsForSplitLoopExit(SmallVectorImpl &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. @@ -224,7 +224,7 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, for (Value::use_iterator UI = TIBB->use_begin(), E = TIBB->use_end(); UI != E; ) { Value::use_iterator Use = UI++; - if (PHINode *PN = dyn_cast(Use)) { + if (PHINode *PN = dyn_cast(*Use)) { // Remove one entry from each PHI. if (PN->getParent() == DestBB && UpdatedPHIs.insert(PN)) PN->setOperand(Use.getOperandNo(), NewBB); @@ -254,12 +254,11 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, if (P == 0) return NewBB; DominatorTree *DT = P->getAnalysisIfAvailable(); - DominanceFrontier *DF = P->getAnalysisIfAvailable(); LoopInfo *LI = P->getAnalysisIfAvailable(); ProfileInfo *PI = P->getAnalysisIfAvailable(); // 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 @@ -280,7 +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); } } @@ -317,40 +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)) { @@ -402,11 +367,13 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, bool HasPredOutsideOfLoop = false; BasicBlock *Exit = ExitBlocks[i]; for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit); - I != E; ++I) - if (TIL->contains(*I)) - Preds.push_back(*I); + I != E; ++I) { + BasicBlock *P = *I; + if (TIL->contains(P)) + Preds.push_back(P); else HasPredOutsideOfLoop = true; + } // If there are any preds not in the loop, we'll need to split // the edges. The Preds.empty() check is needed because a block // may appear multiple times in the list. We can't use