diff options
| -rw-r--r-- | lib/Analysis/LoadValueNumbering.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/Analysis/LoadValueNumbering.cpp b/lib/Analysis/LoadValueNumbering.cpp index b67aaddde3..97a57562bd 100644 --- a/lib/Analysis/LoadValueNumbering.cpp +++ b/lib/Analysis/LoadValueNumbering.cpp @@ -22,6 +22,7 @@ //===----------------------------------------------------------------------===// #include "llvm/Analysis/LoadValueNumbering.h" +#include "llvm/Constant.h" #include "llvm/Function.h" #include "llvm/iMemory.h" #include "llvm/iOther.h" @@ -283,10 +284,14 @@ void LoadVN::getEqualNumberNodes(Value *V, // std::map<BasicBlock*, std::vector<LoadInst*> > CandidateLoads; std::map<BasicBlock*, std::vector<StoreInst*> > CandidateStores; + std::set<AllocationInst*> Allocations; while (!PointerSources.empty()) { Value *Source = PointerSources.back(); PointerSources.pop_back(); // Get a source pointer... + + if (AllocationInst *AI = dyn_cast<AllocationInst>(Source)) + Allocations.insert(AI); for (Value::use_iterator UI = Source->use_begin(), UE = Source->use_end(); UI != UE; ++UI) @@ -329,6 +334,15 @@ void LoadVN::getEqualNumberNodes(Value *V, if (isa<LoadInst>(I) && Instrs.count(I)) { RetVals.push_back(I); Instrs.erase(I); + } else if (AllocationInst *AI = dyn_cast<AllocationInst>(I)) { + // If we run into an allocation of the value being loaded, then the + // contenxt are not initialized. We can return any value, so we will + // return a zero. + if (Allocations.count(AI)) { + LoadInvalidatedInBBBefore = true; + RetVals.push_back(Constant::getNullValue(LI->getType())); + break; + } } if (AA.getModRefInfo(I, LoadPtr, LoadSize) & AliasAnalysis::Mod) { |