Index: llvm/include/llvm/Analysis/LoopInfo.h
===================================================================
--- llvm/include/llvm/Analysis/LoopInfo.h
+++ llvm/include/llvm/Analysis/LoopInfo.h
@@ -346,6 +346,43 @@
     return PreOrderLoops;
   }
 
+  /// Return all inner loops in the loop nest rooted by the loop in
+  /// breadth-first order.
+  template <class Type>
+  static void
+  getInnerLoopsInBreadthFirstOrder(const LoopT &L,
+                                   SmallVectorImpl<Type> &BreadthFirstLoops) {
+    SmallVector<LoopT *, 4> BreadthFirstWorklist;
+    BreadthFirstWorklist.push_back(const_cast<LoopT *>(&L));
+
+    while (!BreadthFirstWorklist.empty()) {
+      LoopT *L = BreadthFirstWorklist.pop_back_val();
+      const auto &SubLoops = L->getSubLoops();
+      if (!SubLoops.empty()) {
+        BreadthFirstWorklist.insert(BreadthFirstWorklist.begin(),
+                                    SubLoops.rbegin(), SubLoops.rend());
+        BreadthFirstLoops.append(SubLoops.begin(), SubLoops.end());
+      }
+    }
+  }
+
+  /// Return all loops in the loop nest rooted by the loop in breadth-first
+  /// order.
+  SmallVector<const LoopT *, 4> getLoopsInBreadthFirstOrder() const {
+    SmallVector<const LoopT *, 4> BreadthFirstLoops;
+    const LoopT *CurLoop = static_cast<const LoopT *>(this);
+    BreadthFirstLoops.push_back(CurLoop);
+    getInnerLoopsInBreadthFirstOrder(*CurLoop, BreadthFirstLoops);
+    return BreadthFirstLoops;
+  }
+  SmallVector<LoopT *, 4> getLoopsInBreadthFirstOrder() {
+    SmallVector<LoopT *, 4> BreadthFirstLoops;
+    LoopT *CurLoop = static_cast<LoopT *>(this);
+    BreadthFirstLoops.push_back(CurLoop);
+    getInnerLoopsInBreadthFirstOrder(*CurLoop, BreadthFirstLoops);
+    return BreadthFirstLoops;
+  }
+
   //===--------------------------------------------------------------------===//
   // APIs for updating loop information after changing the CFG
   //