diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -12757,42 +12757,43 @@
 void ScalarEvolution::forgetMemoizedResults(ArrayRef<const SCEV *> SCEVs) {
   for (auto *S : SCEVs)
     forgetMemoizedResultsImpl(S);
-}
-
-void ScalarEvolution::forgetMemoizedResultsImpl(const SCEV *S) {
-  ValuesAtScopes.erase(S);
-  LoopDispositions.erase(S);
-  BlockDispositions.erase(S);
-  UnsignedRanges.erase(S);
-  SignedRanges.erase(S);
-  ExprValueMap.erase(S);
-  HasRecMap.erase(S);
-  MinTrailingZerosCache.erase(S);
-
+  SmallPtrSet<const SCEV *, 8> ToForget(SCEVs.begin(), SCEVs.end());
   for (auto I = PredicatedSCEVRewrites.begin();
        I != PredicatedSCEVRewrites.end();) {
     std::pair<const SCEV *, const Loop *> Entry = I->first;
-    if (Entry.first == S)
+    if (ToForget.count(Entry.first))
       PredicatedSCEVRewrites.erase(I++);
     else
       ++I;
   }
 
-  auto RemoveSCEVFromBackedgeMap =
-      [S](DenseMap<const Loop *, BackedgeTakenInfo> &Map) {
+  auto RemoveSCEVFromBackedgeMap = [this, &ToForget](
+      DenseMap<const Loop *, BackedgeTakenInfo> &Map) {
         for (auto I = Map.begin(), E = Map.end(); I != E;) {
           BackedgeTakenInfo &BEInfo = I->second;
-          if (BEInfo.hasOperand(S))
+          if (any_of(ToForget,
+                     [&BEInfo](const SCEV *S) { return BEInfo.hasOperand(S); }))
             Map.erase(I++);
           else
             ++I;
         }
-      };
+  };
 
   RemoveSCEVFromBackedgeMap(BackedgeTakenCounts);
   RemoveSCEVFromBackedgeMap(PredicatedBackedgeTakenCounts);
 }
 
+void ScalarEvolution::forgetMemoizedResultsImpl(const SCEV *S) {
+  ValuesAtScopes.erase(S);
+  LoopDispositions.erase(S);
+  BlockDispositions.erase(S);
+  UnsignedRanges.erase(S);
+  SignedRanges.erase(S);
+  ExprValueMap.erase(S);
+  HasRecMap.erase(S);
+  MinTrailingZerosCache.erase(S);
+}
+
 void
 ScalarEvolution::getUsedLoops(const SCEV *S,
                               SmallPtrSetImpl<const Loop *> &LoopsUsed) {