diff --git a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
--- a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -50,6 +50,7 @@
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Dominators.h"
+#include "llvm/IR/PassInstrumentation.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Transforms/Utils/LCSSA.h"
 #include "llvm/Transforms/Utils/LoopSimplify.h"
@@ -303,21 +304,24 @@
       Updater.CurrentL = L;
       Updater.SkipCurrentLoop = false;
 
-#ifndef NDEBUG
-      // Save a parent loop pointer for asserts.
-      Updater.ParentL = L->getParentLoop();
-
-      // Verify the loop structure and LCSSA form before visiting the loop.
-      L->verifyLoop();
-      assert(L->isRecursivelyLCSSAForm(LAR.DT, LI) &&
-             "Loops must remain in LCSSA form!");
-#endif
       // Check the PassInstrumentation's BeforePass callbacks before running the
       // pass, skip its execution completely if asked to (callback returns
       // false).
       if (!PI.runBeforePass<Loop>(Pass, *L))
         continue;
 
+#ifndef NDEBUG
+      if (!isSpecialPass(Pass.name(), {"PassManager"})) {
+        // Save a parent loop pointer for asserts.
+        Updater.ParentL = L->getParentLoop();
+
+        // Verify the loop structure and LCSSA form before visiting the loop.
+        L->verifyLoop();
+        assert(L->isRecursivelyLCSSAForm(LAR.DT, LI) &&
+               "Loops must remain in LCSSA form!");
+      }
+#endif
+
       PreservedAnalyses PassPA;
       {
         TimeTraceScope TimeScope(Pass.name());
diff --git a/llvm/test/Feature/optnone-opt.ll b/llvm/test/Feature/optnone-opt.ll
--- a/llvm/test/Feature/optnone-opt.ll
+++ b/llvm/test/Feature/optnone-opt.ll
@@ -34,7 +34,7 @@
   br label %while.cond
 
 while.end:                                        ; preds = %while.cond
-  ret i32 0
+  ret i32 %dec
 }
 
 attributes #0 = { optnone noinline }