diff options
Diffstat (limited to 'lib/Analysis/LoadValueNumbering.cpp')
| -rw-r--r-- | lib/Analysis/LoadValueNumbering.cpp | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/Analysis/LoadValueNumbering.cpp b/lib/Analysis/LoadValueNumbering.cpp index c47010c383..b433de3d53 100644 --- a/lib/Analysis/LoadValueNumbering.cpp +++ b/lib/Analysis/LoadValueNumbering.cpp @@ -90,6 +90,10 @@ void LoadVN::getEqualNumberNodes(Value *V, getAnalysis<AliasAnalysis>().getMustAliases(V, RetVals); if (LoadInst *LI = dyn_cast<LoadInst>(V)) { + // Volatile loads cannot be replaced with the value of other loads. + if (LI->isVolatile()) + return getAnalysis<ValueNumbering>().getEqualNumberNodes(V, RetVals); + // If we have a load instruction, find all of the load and store // instructions that use the same source operand. We implement this // recursively, because there could be a load of a load of a load that are @@ -119,10 +123,10 @@ void LoadVN::getEqualNumberNodes(Value *V, UI != UE; ++UI) if (LoadInst *Cand = dyn_cast<LoadInst>(*UI)) {// Is a load of source? if (Cand->getParent()->getParent() == F && // In the same function? - Cand != LI) // Not LI itself? + Cand != LI && !Cand->isVolatile()) // Not LI itself? CandidateLoads.push_back(Cand); // Got one... } else if (StoreInst *Cand = dyn_cast<StoreInst>(*UI)) { - if (Cand->getParent()->getParent() == F && + if (Cand->getParent()->getParent() == F && !Cand->isVolatile() && Cand->getOperand(1) == Source) // It's a store THROUGH the ptr... CandidateStores.push_back(Cand); } |