1 files changed, 7 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/Scalar/LoopPassManager.cpp b/contrib/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
index 028f4bba8b1d..10f6fcdcfdb7 100644
--- a/contrib/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
+++ b/contrib/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
@@ -42,6 +42,13 @@ PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
       break;
     }
 
+#ifndef NDEBUG
+    // Verify the loop structure and LCSSA form before visiting the loop.
+    L.verifyLoop();
+    assert(L.isRecursivelyLCSSAForm(AR.DT, AR.LI) &&
+           "Loops must remain in LCSSA form!");
+#endif
+
     // Update the analysis manager as each pass runs and potentially
     // invalidates analyses.
     AM.invalidate(L, PassPA);