Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -6217,6 +6217,9 @@
       if (!DVI)
         continue;
 
+      if (DVI->isUndef())
+        continue;
+
       if (DVI->hasArgList())
         continue;