diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -814,9 +814,12 @@
   LLVM_DEBUG(dbgs() << "LAA: We need to do " << RtCheck.getNumberOfChecks()
                     << " pointer comparisons.\n");
 
-  RtCheck.Need = NeedRTCheck;
+  // If we can do run-time checks, but there are no checks, no runtime checks
+  // are needed. This can happen when all pointers point to the same underlying
+  // object for example.
+  RtCheck.Need = CanDoRT ? RtCheck.getNumberOfChecks() != 0 : NeedRTCheck;
 
-  bool CanDoRTIfNeeded = !NeedRTCheck || CanDoRT;
+  bool CanDoRTIfNeeded = !RtCheck.Need || CanDoRT;
   if (!CanDoRTIfNeeded)
     RtCheck.reset();
   return CanDoRTIfNeeded;
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2795,8 +2795,8 @@
   std::tie(FirstCheckInst, MemRuntimeCheck) =
       addRuntimeChecks(MemCheckBlock->getTerminator(), OrigLoop,
                        RtPtrChecking.getChecks(), RtPtrChecking.getSE());
-  if (!MemRuntimeCheck)
-    return;
+  assert(MemRuntimeCheck && "no RT checks generated although RtPtrChecking "
+                            "claimed checks are required");
 
   if (MemCheckBlock->getParent()->hasOptSize()) {
     assert(Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled &&