1 files changed, 50 insertions, 6 deletions

diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp
index 7ba3268b9e..f8abf3c074 100644
--- a/lib/Analysis/LoopPass.cpp
+++ b/lib/Analysis/LoopPass.cpp
@@ -84,18 +84,62 @@ LPPassManager::LPPassManager(int Depth)
 /// Delete loop from the loop queue and loop hierarchy (LoopInfo).
 void LPPassManager::deleteLoopFromQueue(Loop *L) {
 
-  LI->updateUnloop(L);
+  if (Loop *ParentLoop = L->getParentLoop()) { // Not a top-level loop.
+    // Reparent all of the blocks in this loop.  Since BBLoop had a parent,
+    // they are now all in it.
+    for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+         I != E; ++I)
+      if (LI->getLoopFor(*I) == L)    // Don't change blocks in subloops.
+        LI->changeLoopFor(*I, ParentLoop);
+
+    // Remove the loop from its parent loop.
+    for (Loop::iterator I = ParentLoop->begin(), E = ParentLoop->end();;
+         ++I) {
+      assert(I != E && "Couldn't find loop");
+      if (*I == L) {
+        ParentLoop->removeChildLoop(I);
+        break;
+      }
+    }
+
+    // Move all subloops into the parent loop.
+    while (!L->empty())
+      ParentLoop->addChildLoop(L->removeChildLoop(L->end()-1));
+  } else {
+    // Reparent all of the blocks in this loop.  Since BBLoop had no parent,
+    // they no longer in a loop at all.
+
+    for (unsigned i = 0; i != L->getBlocks().size(); ++i) {
+      // Don't change blocks in subloops.
+      if (LI->getLoopFor(L->getBlocks()[i]) == L) {
+        LI->removeBlock(L->getBlocks()[i]);
+        --i;
+      }
+    }
+
+    // Remove the loop from the top-level LoopInfo object.
+    for (LoopInfo::iterator I = LI->begin(), E = LI->end();; ++I) {
+      assert(I != E && "Couldn't find loop");
+      if (*I == L) {
+        LI->removeLoop(I);
+        break;
+      }
+    }
+
+    // Move all of the subloops to the top-level.
+    while (!L->empty())
+      LI->addTopLevelLoop(L->removeChildLoop(L->end()-1));
+  }
+
+  delete L;
 
   // If L is current loop then skip rest of the passes and let
   // runOnFunction remove L from LQ. Otherwise, remove L from LQ now
   // and continue applying other passes on CurrentLoop.
-  if (CurrentLoop == L)
+  if (CurrentLoop == L) {
     skipThisLoop = true;
-
-  delete L;
-
-  if (skipThisLoop)
     return;
+  }
 
   for (std::deque<Loop *>::iterator I = LQ.begin(),
          E = LQ.end(); I != E; ++I) {