BasicBlock *BB = Release->getParent();
if (Load->getParent() != BB) return;
- // Walk down to find the store.
+ // Walk down to find the store and the release, which may be in either order.
BasicBlock::iterator I = Load, End = BB->end();
++I;
AliasAnalysis::Location Loc = AA->getLocation(Load);
- while (I != End &&
- (&*I == Release ||
- IsRetain(GetBasicInstructionClass(I)) ||
- !(AA->getModRefInfo(I, Loc) & AliasAnalysis::Mod)))
- ++I;
- StoreInst *Store = dyn_cast<StoreInst>(I);
- if (!Store || !Store->isSimple()) return;
- if (Store->getPointerOperand() != Loc.Ptr) return;
+ StoreInst *Store = 0;
+ bool SawRelease = false;
+ for (; !Store || !SawRelease; ++I) {
+ Instruction *Inst = I;
+ if (Inst == Release) {
+ SawRelease = true;
+ continue;
+ }
+
+ InstructionClass Class = GetBasicInstructionClass(Inst);
+
+ // Unrelated retains are harmless.
+ if (IsRetain(Class))
+ continue;
+
+ if (Store) {
+ // The store is the point where we're going to put the objc_storeStrong,
+ // so make sure there are no uses after it.
+ if (CanUse(Inst, Load, PA, Class))
+ return;
+ } else if (AA->getModRefInfo(Inst, Loc) & AliasAnalysis::Mod) {
+ // We are moving the load down to the store, so check for anything
+ // else which writes to the memory between the load and the store.
+ Store = dyn_cast<StoreInst>(Inst);
+ if (!Store || !Store->isSimple()) return;
+ if (Store->getPointerOperand() != Loc.Ptr) return;
+ }
+ }
Value *New = StripPointerCastsAndObjCCalls(Store->getValueOperand());