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author | Stephen Hines <srhines@google.com> | 2015-04-01 18:49:24 +0000 |
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committer | Gerrit Code Review <noreply-gerritcodereview@google.com> | 2015-04-01 18:49:26 +0000 |
commit | 3fa16bd6062e23bcdb82ed4dd965674792e6b761 (patch) | |
tree | 9348fc507292f7e8715d22d64ce5a32131b4f875 /lib/Transforms/Utils/BasicBlockUtils.cpp | |
parent | beed47390a60f6f0c77532b3d3f76bb47ef49423 (diff) | |
parent | ebe69fe11e48d322045d5949c83283927a0d790b (diff) | |
download | external_llvm-3fa16bd6062e23bcdb82ed4dd965674792e6b761.zip external_llvm-3fa16bd6062e23bcdb82ed4dd965674792e6b761.tar.gz external_llvm-3fa16bd6062e23bcdb82ed4dd965674792e6b761.tar.bz2 |
Merge "Update aosp/master LLVM for rebase to r230699."
Diffstat (limited to 'lib/Transforms/Utils/BasicBlockUtils.cpp')
-rw-r--r-- | lib/Transforms/Utils/BasicBlockUtils.cpp | 211 |
1 files changed, 112 insertions, 99 deletions
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp index 983f025..b455257 100644 --- a/lib/Transforms/Utils/BasicBlockUtils.cpp +++ b/lib/Transforms/Utils/BasicBlockUtils.cpp @@ -65,16 +65,10 @@ void llvm::DeleteDeadBlock(BasicBlock *BB) { /// any single-entry PHI nodes in it, fold them away. This handles the case /// when all entries to the PHI nodes in a block are guaranteed equal, such as /// when the block has exactly one predecessor. -void llvm::FoldSingleEntryPHINodes(BasicBlock *BB, Pass *P) { +void llvm::FoldSingleEntryPHINodes(BasicBlock *BB, AliasAnalysis *AA, + MemoryDependenceAnalysis *MemDep) { if (!isa<PHINode>(BB->begin())) return; - AliasAnalysis *AA = nullptr; - MemoryDependenceAnalysis *MemDep = nullptr; - if (P) { - AA = P->getAnalysisIfAvailable<AliasAnalysis>(); - MemDep = P->getAnalysisIfAvailable<MemoryDependenceAnalysis>(); - } - while (PHINode *PN = dyn_cast<PHINode>(BB->begin())) { if (PN->getIncomingValue(0) != PN) PN->replaceAllUsesWith(PN->getIncomingValue(0)); @@ -113,7 +107,9 @@ bool llvm::DeleteDeadPHIs(BasicBlock *BB, const TargetLibraryInfo *TLI) { /// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor, /// if possible. The return value indicates success or failure. -bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) { +bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, DominatorTree *DT, + LoopInfo *LI, AliasAnalysis *AA, + MemoryDependenceAnalysis *MemDep) { // Don't merge away blocks who have their address taken. if (BB->hasAddressTaken()) return false; @@ -149,7 +145,7 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) { // Begin by getting rid of unneeded PHIs. if (isa<PHINode>(BB->front())) - FoldSingleEntryPHINodes(BB, P); + FoldSingleEntryPHINodes(BB, AA, MemDep); // Delete the unconditional branch from the predecessor... PredBB->getInstList().pop_back(); @@ -166,28 +162,23 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) { PredBB->takeName(BB); // Finally, erase the old block and update dominator info. - if (P) { - if (DominatorTreeWrapperPass *DTWP = - P->getAnalysisIfAvailable<DominatorTreeWrapperPass>()) { - DominatorTree &DT = DTWP->getDomTree(); - if (DomTreeNode *DTN = DT.getNode(BB)) { - DomTreeNode *PredDTN = DT.getNode(PredBB); - SmallVector<DomTreeNode*, 8> Children(DTN->begin(), DTN->end()); - for (SmallVectorImpl<DomTreeNode *>::iterator DI = Children.begin(), - DE = Children.end(); DI != DE; ++DI) - DT.changeImmediateDominator(*DI, PredDTN); - - DT.eraseNode(BB); - } + if (DT) + if (DomTreeNode *DTN = DT->getNode(BB)) { + DomTreeNode *PredDTN = DT->getNode(PredBB); + SmallVector<DomTreeNode *, 8> Children(DTN->begin(), DTN->end()); + for (SmallVectorImpl<DomTreeNode *>::iterator DI = Children.begin(), + DE = Children.end(); + DI != DE; ++DI) + DT->changeImmediateDominator(*DI, PredDTN); + + DT->eraseNode(BB); + } - if (LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>()) - LI->removeBlock(BB); + if (LI) + LI->removeBlock(BB); - if (MemoryDependenceAnalysis *MD = - P->getAnalysisIfAvailable<MemoryDependenceAnalysis>()) - MD->invalidateCachedPredecessors(); - } - } + if (MemDep) + MemDep->invalidateCachedPredecessors(); BB->eraseFromParent(); return true; @@ -240,12 +231,14 @@ void llvm::ReplaceInstWithInst(Instruction *From, Instruction *To) { /// SplitEdge - Split the edge connecting specified block. Pass P must /// not be NULL. -BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) { +BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, DominatorTree *DT, + LoopInfo *LI) { unsigned SuccNum = GetSuccessorNumber(BB, Succ); // If this is a critical edge, let SplitCriticalEdge do it. TerminatorInst *LatchTerm = BB->getTerminator(); - if (SplitCriticalEdge(LatchTerm, SuccNum, P)) + if (SplitCriticalEdge(LatchTerm, SuccNum, CriticalEdgeSplittingOptions(DT, LI) + .setPreserveLCSSA())) return LatchTerm->getSuccessor(SuccNum); // If the edge isn't critical, then BB has a single successor or Succ has a @@ -255,23 +248,25 @@ BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) { // block. assert(SP == BB && "CFG broken"); SP = nullptr; - return SplitBlock(Succ, Succ->begin(), P); + return SplitBlock(Succ, Succ->begin(), DT, LI); } // Otherwise, if BB has a single successor, split it at the bottom of the // block. assert(BB->getTerminator()->getNumSuccessors() == 1 && "Should have a single succ!"); - return SplitBlock(BB, BB->getTerminator(), P); + return SplitBlock(BB, BB->getTerminator(), DT, LI); } -unsigned llvm::SplitAllCriticalEdges(Function &F, Pass *P) { +unsigned +llvm::SplitAllCriticalEdges(Function &F, + const CriticalEdgeSplittingOptions &Options) { unsigned NumBroken = 0; for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) { TerminatorInst *TI = I->getTerminator(); if (TI->getNumSuccessors() > 1 && !isa<IndirectBrInst>(TI)) for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) - if (SplitCriticalEdge(TI, i, P)) + if (SplitCriticalEdge(TI, i, Options)) ++NumBroken; } return NumBroken; @@ -282,7 +277,8 @@ unsigned llvm::SplitAllCriticalEdges(Function &F, Pass *P) { /// to a new block. The two blocks are joined by an unconditional branch and /// the loop info is updated. /// -BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) { +BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, + DominatorTree *DT, LoopInfo *LI) { BasicBlock::iterator SplitIt = SplitPt; while (isa<PHINode>(SplitIt) || isa<LandingPadInst>(SplitIt)) ++SplitIt; @@ -290,26 +286,23 @@ BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) { // The new block lives in whichever loop the old one did. This preserves // LCSSA as well, because we force the split point to be after any PHI nodes. - if (LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>()) + if (LI) if (Loop *L = LI->getLoopFor(Old)) - L->addBasicBlockToLoop(New, LI->getBase()); + L->addBasicBlockToLoop(New, *LI); - if (DominatorTreeWrapperPass *DTWP = - P->getAnalysisIfAvailable<DominatorTreeWrapperPass>()) { - DominatorTree &DT = DTWP->getDomTree(); + if (DT) // Old dominates New. New node dominates all other nodes dominated by Old. - if (DomTreeNode *OldNode = DT.getNode(Old)) { + if (DomTreeNode *OldNode = DT->getNode(Old)) { std::vector<DomTreeNode *> Children; for (DomTreeNode::iterator I = OldNode->begin(), E = OldNode->end(); I != E; ++I) Children.push_back(*I); - DomTreeNode *NewNode = DT.addNewBlock(New, Old); + DomTreeNode *NewNode = DT->addNewBlock(New, Old); for (std::vector<DomTreeNode *>::iterator I = Children.begin(), E = Children.end(); I != E; ++I) - DT.changeImmediateDominator(*I, NewNode); + DT->changeImmediateDominator(*I, NewNode); } - } return New; } @@ -318,45 +311,46 @@ BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) { /// analysis information. static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB, ArrayRef<BasicBlock *> Preds, - Pass *P, bool &HasLoopExit) { - if (!P) return; + DominatorTree *DT, LoopInfo *LI, + bool PreserveLCSSA, bool &HasLoopExit) { + // Update dominator tree if available. + if (DT) + DT->splitBlock(NewBB); + + // The rest of the logic is only relevant for updating the loop structures. + if (!LI) + return; - LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>(); - Loop *L = LI ? LI->getLoopFor(OldBB) : nullptr; + Loop *L = LI->getLoopFor(OldBB); // If we need to preserve loop analyses, collect some information about how // this split will affect loops. bool IsLoopEntry = !!L; bool SplitMakesNewLoopHeader = false; - if (LI) { - bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID); - for (ArrayRef<BasicBlock*>::iterator - i = Preds.begin(), e = Preds.end(); i != e; ++i) { - BasicBlock *Pred = *i; - - // If we need to preserve LCSSA, determine if any of the preds is a loop - // exit. - if (PreserveLCSSA) - if (Loop *PL = LI->getLoopFor(Pred)) - if (!PL->contains(OldBB)) - HasLoopExit = true; - - // If we need to preserve LoopInfo, note whether any of the preds crosses - // an interesting loop boundary. - if (!L) continue; - if (L->contains(Pred)) - IsLoopEntry = false; - else - SplitMakesNewLoopHeader = true; - } + for (ArrayRef<BasicBlock *>::iterator i = Preds.begin(), e = Preds.end(); + i != e; ++i) { + BasicBlock *Pred = *i; + + // If we need to preserve LCSSA, determine if any of the preds is a loop + // exit. + if (PreserveLCSSA) + if (Loop *PL = LI->getLoopFor(Pred)) + if (!PL->contains(OldBB)) + HasLoopExit = true; + + // If we need to preserve LoopInfo, note whether any of the preds crosses + // an interesting loop boundary. + if (!L) + continue; + if (L->contains(Pred)) + IsLoopEntry = false; + else + SplitMakesNewLoopHeader = true; } - // Update dominator tree if available. - if (DominatorTreeWrapperPass *DTWP = - P->getAnalysisIfAvailable<DominatorTreeWrapperPass>()) - DTWP->getDomTree().splitBlock(NewBB); - - if (!L) return; + // Unless we have a loop for OldBB, nothing else to do here. + if (!L) + return; if (IsLoopEntry) { // Add the new block to the nearest enclosing loop (and not an adjacent @@ -382,9 +376,9 @@ static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB, } if (InnermostPredLoop) - InnermostPredLoop->addBasicBlockToLoop(NewBB, LI->getBase()); + InnermostPredLoop->addBasicBlockToLoop(NewBB, *LI); } else { - L->addBasicBlockToLoop(NewBB, LI->getBase()); + L->addBasicBlockToLoop(NewBB, *LI); if (SplitMakesNewLoopHeader) L->moveToHeader(NewBB); } @@ -393,10 +387,9 @@ static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB, /// UpdatePHINodes - Update the PHI nodes in OrigBB to include the values coming /// from NewBB. This also updates AliasAnalysis, if available. static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB, - ArrayRef<BasicBlock*> Preds, BranchInst *BI, - Pass *P, bool HasLoopExit) { + ArrayRef<BasicBlock *> Preds, BranchInst *BI, + AliasAnalysis *AA, bool HasLoopExit) { // Otherwise, create a new PHI node in NewBB for each PHI node in OrigBB. - AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : nullptr; SmallPtrSet<BasicBlock *, 16> PredSet(Preds.begin(), Preds.end()); for (BasicBlock::iterator I = OrigBB->begin(); isa<PHINode>(I); ) { PHINode *PN = cast<PHINode>(I++); @@ -461,11 +454,15 @@ static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB, } } -/// SplitBlockPredecessors - This method transforms BB by introducing a new -/// basic block into the function, and moving some of the predecessors of BB to -/// be predecessors of the new block. The new predecessors are indicated by the -/// Preds array, which has NumPreds elements in it. The new block is given a -/// suffix of 'Suffix'. +/// SplitBlockPredecessors - This method introduces at least one new basic block +/// into the function and moves some of the predecessors of BB to be +/// predecessors of the new block. The new predecessors are indicated by the +/// Preds array. The new block is given a suffix of 'Suffix'. Returns new basic +/// block to which predecessors from Preds are now pointing. +/// +/// If BB is a landingpad block then additional basicblock might be introduced. +/// It will have suffix of 'Suffix'+".split_lp". +/// See SplitLandingPadPredecessors for more details on this case. /// /// This currently updates the LLVM IR, AliasAnalysis, DominatorTree, /// LoopInfo, and LCCSA but no other analyses. In particular, it does not @@ -473,8 +470,21 @@ static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB, /// of the edges being split is an exit of a loop with other exits). /// BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB, - ArrayRef<BasicBlock*> Preds, - const char *Suffix, Pass *P) { + ArrayRef<BasicBlock *> Preds, + const char *Suffix, AliasAnalysis *AA, + DominatorTree *DT, LoopInfo *LI, + bool PreserveLCSSA) { + // For the landingpads we need to act a bit differently. + // Delegate this work to the SplitLandingPadPredecessors. + if (BB->isLandingPad()) { + SmallVector<BasicBlock*, 2> NewBBs; + std::string NewName = std::string(Suffix) + ".split-lp"; + + SplitLandingPadPredecessors(BB, Preds, Suffix, NewName.c_str(), + NewBBs, AA, DT, LI, PreserveLCSSA); + return NewBBs[0]; + } + // Create new basic block, insert right before the original block. BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), BB->getName()+Suffix, BB->getParent(), BB); @@ -505,10 +515,11 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB, // Update DominatorTree, LoopInfo, and LCCSA analysis information. bool HasLoopExit = false; - UpdateAnalysisInformation(BB, NewBB, Preds, P, HasLoopExit); + UpdateAnalysisInformation(BB, NewBB, Preds, DT, LI, PreserveLCSSA, + HasLoopExit); // Update the PHI nodes in BB with the values coming from NewBB. - UpdatePHINodes(BB, NewBB, Preds, BI, P, HasLoopExit); + UpdatePHINodes(BB, NewBB, Preds, BI, AA, HasLoopExit); return NewBB; } @@ -526,10 +537,11 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB, /// exits). /// void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB, - ArrayRef<BasicBlock*> Preds, + ArrayRef<BasicBlock *> Preds, const char *Suffix1, const char *Suffix2, - Pass *P, - SmallVectorImpl<BasicBlock*> &NewBBs) { + SmallVectorImpl<BasicBlock *> &NewBBs, + AliasAnalysis *AA, DominatorTree *DT, + LoopInfo *LI, bool PreserveLCSSA) { assert(OrigBB->isLandingPad() && "Trying to split a non-landing pad!"); // Create a new basic block for OrigBB's predecessors listed in Preds. Insert @@ -552,12 +564,12 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB, Preds[i]->getTerminator()->replaceUsesOfWith(OrigBB, NewBB1); } - // Update DominatorTree, LoopInfo, and LCCSA analysis information. bool HasLoopExit = false; - UpdateAnalysisInformation(OrigBB, NewBB1, Preds, P, HasLoopExit); + UpdateAnalysisInformation(OrigBB, NewBB1, Preds, DT, LI, PreserveLCSSA, + HasLoopExit); // Update the PHI nodes in OrigBB with the values coming from NewBB1. - UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, P, HasLoopExit); + UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, AA, HasLoopExit); // Move the remaining edges from OrigBB to point to NewBB2. SmallVector<BasicBlock*, 8> NewBB2Preds; @@ -589,10 +601,11 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB, // Update DominatorTree, LoopInfo, and LCCSA analysis information. HasLoopExit = false; - UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, P, HasLoopExit); + UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, DT, LI, + PreserveLCSSA, HasLoopExit); // Update the PHI nodes in OrigBB with the values coming from NewBB2. - UpdatePHINodes(OrigBB, NewBB2, NewBB2Preds, BI2, P, HasLoopExit); + UpdatePHINodes(OrigBB, NewBB2, NewBB2Preds, BI2, AA, HasLoopExit); } LandingPadInst *LPad = OrigBB->getLandingPadInst(); |