[llvm] r265625 - Follow-up for r265605: don't mutate vector we're iterating.

[Michael Zolotukhin via llvm-commits]

Author: mzolotukhin
Date: Wed Apr  6 19:09:42 2016
New Revision: 265625

URL: http://llvm.org/viewvc/llvm-project?rev=265625&view=rev
Log:
Follow-up for r265605: don't mutate vector we're iterating.

Modified:
    llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp

Modified: llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp?rev=265625&r1=265624&r2=265625&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp Wed Apr  6 19:09:42 2016
@@ -563,13 +563,15 @@ bool llvm::UnrollLoop(Loop *L, unsigned
   if (DT && Count > 1) {
     for (auto *BB : OriginalLoopBlocks) {
       auto *BBDomNode = DT->getNode(BB);
+      SmallVector<BasicBlock *, 16> ChildrenToUpdate;
       for (auto *ChildDomNode : BBDomNode->getChildren()) {
         auto *ChildBB = ChildDomNode->getBlock();
-        if (L->contains(ChildBB))
-          continue;
-        BasicBlock *NewIDom = DT->findNearestCommonDominator(BB, Latches[0]);
-        DT->changeImmediateDominator(ChildBB, NewIDom);
+        if (!L->contains(ChildBB))
+          ChildrenToUpdate.push_back(ChildBB);
       }
+      BasicBlock *NewIDom = DT->findNearestCommonDominator(BB, Latches[0]);
+      for (auto *ChildBB : ChildrenToUpdate)
+        DT->changeImmediateDominator(ChildBB, NewIDom);
     }
   }