[LoopUnroll] Use addClonedBlockToLoopInfo to clone the top level loop…

… (NFC)

Summary:
rL293124 added the necessary infrastructure to properly add the cloned
top level loop to LoopInfo, which means we do not have to do it manually
in CloneLoopBlocks.

@mkuper sorry for not pointing this out during my review of D29156, I just
realized that today.


Reviewers: mzolotukhin, chandlerc, mkuper

Reviewed By: mkuper

Subscribers: llvm-commits, mkuper

Differential Revision: https://reviews.llvm.org/D29173

llvm-svn: 293615

llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp

@@ -300,28 +300,18 @@ static void CloneLoopBlocks(Loop *L, Value *NewIter,
   Function *F = Header->getParent();
   LoopBlocksDFS::RPOIterator BlockBegin = LoopBlocks.beginRPO();
   LoopBlocksDFS::RPOIterator BlockEnd = LoopBlocks.endRPO();
-  Loop *NewLoop = nullptr;
   Loop *ParentLoop = L->getParentLoop();
-  if (CreateRemainderLoop) {
-    NewLoop = new Loop();
-    if (ParentLoop)
-      ParentLoop->addChildLoop(NewLoop);
-    else
-      LI->addTopLevelLoop(NewLoop);
-  }
-
   NewLoopsMap NewLoops;
-  if (NewLoop)
-    NewLoops[L] = NewLoop;
-  else if (ParentLoop)
+  NewLoops[ParentLoop] = ParentLoop;
+  if (!CreateRemainderLoop)
     NewLoops[L] = ParentLoop;
 
   // For each block in the original loop, create a new copy,
   // and update the value map with the newly created values.
   for (LoopBlocksDFS::RPOIterator BB = BlockBegin; BB != BlockEnd; ++BB) {
     BasicBlock *NewBB = CloneBasicBlock(*BB, VMap, "." + suffix, F);
     NewBlocks.push_back(NewBB);
-   
+
     // If we're unrolling the outermost loop, there's no remainder loop,
     // and this block isn't in a nested loop, then the new block is not
     // in any loop. Otherwise, add it to loopinfo.
@@ -396,7 +386,9 @@ static void CloneLoopBlocks(Loop *L, Value *NewIter,
         NewPHI->setIncomingValue(idx, V);
     }
   }
-  if (NewLoop) {
+  if (CreateRemainderLoop) {
+    Loop *NewLoop = NewLoops[L];
+    assert(NewLoop && "L should have been cloned");
     // Add unroll disable metadata to disable future unrolling for this loop.
     SmallVector<Metadata *, 4> MDs;
     // Reserve first location for self reference to the LoopID metadata node.