diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index cc28e54c37..2cf4ab9cde 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -764,12 +764,19 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->begin())) { // Check to see if the first instruction in this block is just an unwind. // If so, replace any invoke instructions which use this as an exception - // destination with call instructions. + // destination with call instructions, and any unconditional branch + // predecessor with an unwind. // std::vector<BasicBlock*> Preds(pred_begin(BB), pred_end(BB)); while (!Preds.empty()) { BasicBlock *Pred = Preds.back(); - if (InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator())) + if (BranchInst *BI = dyn_cast<BranchInst>(Pred->getTerminator())) { + if (BI->isUnconditional()) { + Pred->getInstList().pop_back(); // nuke uncond branch + new UnwindInst(Pred); // Use unwind. + Changed = true; + } + } else if (InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator())) if (II->getUnwindDest() == BB) { // Insert a new branch instruction before the invoke, because this // is now a fall through... |