ScalerEvolution: Only erase temporary values if they actually have been added

This addresses post-review comments from Sanjoy Das for r261485.

llvm-svn: 261486

1 files changed, 6 insertions, 5 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 6e8fa5d43b2..07d72f5ee20 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -3895,13 +3895,14 @@ const SCEV *ScalarEvolution::createAddRecFromPHI(PHINode *PN) {
         }
       }
     }
+
+    // Remove the temporary PHI node SCEV that has been inserted while intending
+    // to create an AddRecExpr for this PHI node. We can not keep this temporary
+    // as it will prevent later (possibly simpler) SCEV expressions to be added
+    // to the ValueExprMap.
+    ValueExprMap.erase(PN);
   }
 
-  // Remove the temporary PHI node SCEV that has been inserted while intending
-  // to create an AddRecExpr for this PHI node. We can not keep this temporary
-  // as it will prevent later (possibly simpler) SCEV expressions to be added
-  // to the ValueExprMap.
-  ValueExprMap.erase(PN);
   return nullptr;
 }