[LLVMdev] Question about GVN

[Jakub Staszak]

Hello, I was investigating GVN.cpp file and I found suspicious part:

1587   bool NeedToSplitEdges = false;
1588   for (pred_iterator PI = pred_begin(LoadBB), E = pred_end(LoadBB);
1589        PI != E; ++PI) {
1590     BasicBlock *Pred = *PI;
1591     if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks)) {
1592       continue;
1593     }
1594     PredLoads[Pred] = 0;
1595 
1596     if (Pred->getTerminator()->getNumSuccessors() != 1) {
1597       if (isa<IndirectBrInst>(Pred->getTerminator())) {
1598         DEBUG(dbgs() << "COULD NOT PRE LOAD BECAUSE OF INDBR CRITICAL EDGE '"
1599               << Pred->getName() << "': " << *LI << '\n');
1600         return false;
1601       }
1602       unsigned SuccNum = GetSuccessorNumber(Pred, LoadBB);
1603       toSplit.push_back(std::make_pair(Pred->getTerminator(), SuccNum));
1604       NeedToSplitEdges = true;
1605     }
1606   }
1607   if (NeedToSplitEdges)
1608     return false;

Because it iterates over predecessors it may happen that not the first one has IndirectBrInst terminator.
However some "toSplit" edges can be already added. Is this OK?
Maybe I just misunderstood something?

Regards
-- 
Jakub Staszak