diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 2092c8b58a..61da0d998f 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1237,6 +1237,8 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { SmallVector<BasicBlock*, 8> UncondBranchPreds; SmallVector<BranchInst*, 8> CondBranchPreds; for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) { + if ((*PI)->getUnwindDest() == BB) continue; + TerminatorInst *PTI = (*PI)->getTerminator(); if (BranchInst *BI = dyn_cast<BranchInst>(PTI)) { if (BI->isUnconditional()) @@ -1788,6 +1790,7 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { BasicBlock *OnlySucc = 0; if (OnlyPred && OnlyPred != BB && // Don't break self loops + OnlyPred->getUnwindDest() != BB && OnlyPred->getTerminator()->getOpcode() != Instruction::Invoke) { // Check to see if there is only one distinct successor... succ_iterator SI(succ_begin(OnlyPred)), SE(succ_end(OnlyPred)); @@ -1799,7 +1802,8 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { } } - if (OnlySucc) { + if (OnlySucc && (BB->getUnwindDest() == OnlyPred->getUnwindDest() || + !BB->getUnwindDest() || !OnlyPred->getUnwindDest())) { DOUT << "Merging: " << *BB << "into: " << *OnlyPred; // Resolve any PHI nodes at the start of the block. They are all @@ -1819,6 +1823,10 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { // Move all definitions in the successor to the predecessor. OnlyPred->getInstList().splice(OnlyPred->end(), BB->getInstList()); + // Move the unwind_to block + if (!OnlyPred->getUnwindDest() && BB->getUnwindDest()) + OnlyPred->setUnwindDest(BB->getUnwindDest()); + // Make all PHI nodes that referred to BB now refer to Pred as their // source. BB->replaceAllUsesWith(OnlyPred); |