Index: lib/Analysis/LoopInfo.cpp
===================================================================
--- lib/Analysis/LoopInfo.cpp
+++ lib/Analysis/LoopInfo.cpp
@@ -512,11 +512,14 @@
 /// For subloop blocks, simply update SubloopParents and return NULL.
 Loop *UnloopUpdater::getNearestLoop(BasicBlock *BB, Loop *BBLoop) {
 
+  assert(Unloop && "Unloop cannot be NULL");
+
   // Initially for blocks directly contained by Unloop, NearLoop == Unloop and
   // is considered uninitialized.
   Loop *NearLoop = BBLoop;
 
   Loop *Subloop = nullptr;
+  assert(Unloop && "does not contain any loop");
   if (NearLoop != Unloop && Unloop->contains(NearLoop)) {
     Subloop = NearLoop;
     // Find the subloop ancestor that is directly contained within Unloop.
@@ -545,6 +548,7 @@
       assert((FoundIB || !DFS.hasPostorder(*I)) && "should have seen IB");
       FoundIB = true;
     }
+    assert(Unloop && "does not contain any loop");
     if (L != Unloop && Unloop->contains(L)) {
       // Successor is in a subloop.
       if (Subloop)
Index: lib/Analysis/ScalarEvolution.cpp
===================================================================
--- lib/Analysis/ScalarEvolution.cpp
+++ lib/Analysis/ScalarEvolution.cpp
@@ -5554,6 +5554,8 @@
   if (NumExits == 1)
     return;
 
+  assert(ENT && "ExitNotTakenExtras array is NULL, cannot further compute exits");
+
   auto &Exits = ExitNotTaken.ExtraInfo->Exits;
 
   // Handle the rare case of multiple computable exits.