Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -3836,8 +3836,12 @@
     return;
   if (IsScaledReg)
     F.ScaledReg = G;
-  else
+  else {
     F.BaseRegs[Idx] = G;
+    // We may generate non canonical Formula if G is a recurrent expr reg
+    // related with current loop while F.ScaledReg is not.
+    F.canonicalize(*L);
+  }
   (void)InsertFormula(LU, LUIdx, F);
 }