diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnswitch.cpp | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index 953724448e..498d3785f9 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -84,6 +84,7 @@ namespace { AU.addRequiredID(LoopSimplifyID); AU.addPreservedID(LoopSimplifyID); AU.addPreserved<DominatorTree>(); + AU.addPreserved<DominanceFrontier>(); AU.addRequired<LoopInfo>(); AU.addPreserved<LoopInfo>(); AU.addRequiredID(LCSSAID); @@ -415,6 +416,9 @@ BasicBlock *LoopUnswitch::SplitBlock(BasicBlock *Old, Instruction *SplitPt) { if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) DT->addNewBlock(New, Old); + + if (DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>()) + DF->splitBlock(Old); return New; } @@ -471,7 +475,7 @@ static inline void RemapInstruction(Instruction *I, // If Orig is in Loop then find and use Orig dominator's cloned block as NewBB // dominator. void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L, - DominatorTree *DT, + DominatorTree *DT, DominanceFrontier *DF, DenseMap<const Value*, Value*> &VM) { DomTreeNode *OrigNode = DT->getNode(Orig); @@ -481,7 +485,7 @@ void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L, BasicBlock *NewIDom = OrigIDom; if (L->contains(OrigIDom)) { if (!DT->getNode(OrigIDom)) - CloneDomInfo(NewIDom, OrigIDom, L, DT, VM); + CloneDomInfo(NewIDom, OrigIDom, L, DT, DF, VM); NewIDom = cast<BasicBlock>(VM[OrigIDom]); } if (NewBB == NewIDom) { @@ -489,6 +493,23 @@ void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L, DT->changeImmediateDominator(NewBB, NewIDom); } else DT->addNewBlock(NewBB, NewIDom); + + DominanceFrontier::DomSetType NewDFSet; + if (DF) { + DominanceFrontier::iterator DFI = DF->find(Orig); + if ( DFI != DF->end()) { + DominanceFrontier::DomSetType S = DFI->second; + for (DominanceFrontier::DomSetType::iterator I = S.begin(), E = S.end(); + I != E; ++I) { + BasicBlock *BB = *I; + if (L->contains(BB)) + NewDFSet.insert(cast<BasicBlock>(VM[Orig])); + else + NewDFSet.insert(BB); + } + } + DF->addBasicBlock(NewBB, NewDFSet); + } } /// CloneLoop - Recursively clone the specified loop and all of its children, @@ -532,12 +553,14 @@ void LoopUnswitch::EmitPreheaderBranchOnCondition(Value *LIC, Constant *Val, BranchInst *BRI = new BranchInst(TrueDest, FalseDest, BranchVal, InsertPt); // Update dominator info. + // BranchVal is a new preheader so it dominates true and false destination + // loop headers. if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) { - // BranchVal is a new preheader so it dominates true and false destination - // loop headers. DT->changeImmediateDominator(TrueDest, BRI->getParent()); DT->changeImmediateDominator(FalseDest, BRI->getParent()); } + // No need to update DominanceFrontier. BRI->getParent() dominated TrueDest + // and FalseDest anyway. Now it immediately dominates them. } @@ -679,11 +702,12 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val, } // Update dominator info + DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>(); if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) for (unsigned i = 0, e = LoopBlocks.size(); i != e; ++i) { BasicBlock *LBB = LoopBlocks[i]; BasicBlock *NBB = NewBlocks[i]; - CloneDomInfo(NBB, LBB, L, DT, ValueMap); + CloneDomInfo(NBB, LBB, L, DT, DF, ValueMap); } // Splice the newly inserted blocks into the function right before the |