Merge with LLVM upstream r145126 (Nov 25th 2011)

Change-Id: I30d08ae004a4c3c74092ad2537ab30cce4280e1d

1 files changed, 9 insertions, 11 deletions

diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index 85aacca..c7833bf 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -477,21 +477,19 @@ void UnloopUpdater::updateBlockParents() {
 /// removeBlocksFromAncestors - Remove unloop's blocks from all ancestors below
 /// their new parents.
 void UnloopUpdater::removeBlocksFromAncestors() {
-  // Remove unloop's blocks from all ancestors below their new parents.
+  // Remove all unloop's blocks (including those in nested subloops) from
+  // ancestors below the new parent loop.
   for (Loop::block_iterator BI = Unloop->block_begin(),
          BE = Unloop->block_end(); BI != BE; ++BI) {
-    Loop *NewParent = LI->getLoopFor(*BI);
-    // If this block is an immediate subloop, remove all blocks (including
-    // nested subloops) from ancestors below the new parent loop.
-    // Otherwise, if this block is in a nested subloop, skip it.
-    if (SubloopParents.count(NewParent))
-      NewParent = SubloopParents[NewParent];
-    else if (Unloop->contains(NewParent))
-      continue;
-
+    Loop *OuterParent = LI->getLoopFor(*BI);
+    if (Unloop->contains(OuterParent)) {
+      while (OuterParent->getParentLoop() != Unloop)
+        OuterParent = OuterParent->getParentLoop();
+      OuterParent = SubloopParents[OuterParent];
+    }
     // Remove blocks from former Ancestors except Unloop itself which will be
     // deleted.
-    for (Loop *OldParent = Unloop->getParentLoop(); OldParent != NewParent;
+    for (Loop *OldParent = Unloop->getParentLoop(); OldParent != OuterParent;
          OldParent = OldParent->getParentLoop()) {
       assert(OldParent && "new loop is not an ancestor of the original");
       OldParent->removeBlockFromLoop(*BI);