diff options
| -rw-r--r-- | lib/Transforms/Scalar/GVN.cpp | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index 8124169355..9785b31892 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -1446,8 +1446,8 @@ bool GVN::processNonLocalLoad(LoadInst *LI) { for (unsigned i = 0, e = UnavailableBlocks.size(); i != e; ++i) Blockers.insert(UnavailableBlocks[i]); - // Lets find first basic block with more than one predecessor. Walk backwards - // through predecessors if needed. + // Let's find the first basic block with more than one predecessor. Walk + // backwards through predecessors if needed. BasicBlock *LoadBB = LI->getParent(); BasicBlock *TmpBB = LoadBB; @@ -1519,10 +1519,19 @@ bool GVN::processNonLocalLoad(LoadInst *LI) { << Pred->getName() << "': " << *LI << '\n'); return false; } + + if (LoadBB->isLandingPad()) { + DEBUG(dbgs() + << "COULD NOT PRE LOAD BECAUSE OF LANDING PAD CRITICAL EDGE '" + << Pred->getName() << "': " << *LI << '\n'); + return false; + } + unsigned SuccNum = GetSuccessorNumber(Pred, LoadBB); NeedToSplit.push_back(std::make_pair(Pred->getTerminator(), SuccNum)); } } + if (!NeedToSplit.empty()) { toSplit.append(NeedToSplit.begin(), NeedToSplit.end()); return false; @@ -2071,6 +2080,9 @@ bool GVN::performPRE(Function &F) { // Nothing to PRE in the entry block. if (CurrentBlock == &F.getEntryBlock()) continue; + // Don't perform PRE on a landing pad. + if (CurrentBlock->isLandingPad()) continue; + for (BasicBlock::iterator BI = CurrentBlock->begin(), BE = CurrentBlock->end(); BI != BE; ) { Instruction *CurInst = BI++; |