diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnswitch.cpp | 4 | ||||
| -rw-r--r-- | lib/Transforms/Utils/BreakCriticalEdges.cpp | 37 |
2 files changed, 28 insertions, 13 deletions
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index 7e485b8113..930980f528 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -687,8 +687,8 @@ void LoopUnswitch::EmitPreheaderBranchOnCondition(Value *LIC, Constant *Val, // If either edge is critical, split it. This helps preserve LoopSimplify // form for enclosing loops. - SplitCriticalEdge(BI, 0, this); - SplitCriticalEdge(BI, 1, this); + SplitCriticalEdge(BI, 0, this, false, false, true); + SplitCriticalEdge(BI, 1, this, false, false, true); } /// UnswitchTrivialCondition - Given a loop that has a trivial unswitchable diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp index f752d7981c..060cd015eb 100644 --- a/lib/Transforms/Utils/BreakCriticalEdges.cpp +++ b/lib/Transforms/Utils/BreakCriticalEdges.cpp @@ -119,31 +119,36 @@ bool llvm::isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, /// CreatePHIsForSplitLoopExit - When a loop exit edge is split, LCSSA form /// may require new PHIs in the new exit block. This function inserts the -/// new PHIs, as needed. Preds is a list of preds inside the loop, SplitBB +/// new PHIs, as needed. Preds is a list of preds inside the loop, SplitBB /// is the new loop exit block, and DestBB is the old loop exit, now the /// successor of SplitBB. static void CreatePHIsForSplitLoopExit(SmallVectorImpl<BasicBlock *> &Preds, BasicBlock *SplitBB, BasicBlock *DestBB) { // SplitBB shouldn't have anything non-trivial in it yet. - assert(SplitBB->getFirstNonPHI() == SplitBB->getTerminator() && - "SplitBB has non-PHI nodes!"); + assert((SplitBB->getFirstNonPHI() == SplitBB->getTerminator() || + SplitBB->isLandingPad()) && "SplitBB has non-PHI nodes!"); - // For each PHI in the destination block... + // For each PHI in the destination block. for (BasicBlock::iterator I = DestBB->begin(); PHINode *PN = dyn_cast<PHINode>(I); ++I) { unsigned Idx = PN->getBasicBlockIndex(SplitBB); Value *V = PN->getIncomingValue(Idx); + // If the input is a PHI which already satisfies LCSSA, don't create // a new one. if (const PHINode *VP = dyn_cast<PHINode>(V)) if (VP->getParent() == SplitBB) continue; + // Otherwise a new PHI is needed. Create one and populate it. - PHINode *NewPN = PHINode::Create(PN->getType(), Preds.size(), "split", - SplitBB->getTerminator()); + PHINode *NewPN = + PHINode::Create(PN->getType(), Preds.size(), "split", + SplitBB->isLandingPad() ? + SplitBB->begin() : SplitBB->getTerminator()); for (unsigned i = 0, e = Preds.size(); i != e; ++i) NewPN->addIncoming(V, Preds[i]); + // Update the original PHI. PN->setIncomingValue(Idx, NewPN); } @@ -168,7 +173,8 @@ static void CreatePHIsForSplitLoopExit(SmallVectorImpl<BasicBlock *> &Preds, /// BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P, bool MergeIdenticalEdges, - bool DontDeleteUselessPhis) { + bool DontDeleteUselessPhis, + bool SplitLandingPads) { if (!isCriticalEdge(TI, SuccNum, MergeIdenticalEdges)) return 0; assert(!isa<IndirectBrInst>(TI) && @@ -371,10 +377,19 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, // getUniqueExitBlocks above because that depends on LoopSimplify // form, which we're in the process of restoring! if (!Preds.empty() && HasPredOutsideOfLoop) { - BasicBlock *NewExitBB = - SplitBlockPredecessors(Exit, Preds, "split", P); - if (P->mustPreserveAnalysisID(LCSSAID)) - CreatePHIsForSplitLoopExit(Preds, NewExitBB, Exit); + if (!Exit->isLandingPad()) { + BasicBlock *NewExitBB = + SplitBlockPredecessors(Exit, Preds, "split", P); + if (P->mustPreserveAnalysisID(LCSSAID)) + createPHIsForSplitLoopExit(Preds, NewExitBB, Exit); + } else if (SplitLandingPads) { + SmallVector<BasicBlock*, 8> NewBBs; + SplitLandingPadPredecessors(Exit, Preds, + ".split1", ".split2", + P, NewBBs); + if (P->mustPreserveAnalysisID(LCSSAID)) + createPHIsForSplitLoopExit(Preds, NewBBs[0], Exit); + } } } } |