Index: llvm/include/llvm/Analysis/AssumptionCache.h
===================================================================
--- llvm/include/llvm/Analysis/AssumptionCache.h
+++ llvm/include/llvm/Analysis/AssumptionCache.h
@@ -73,8 +73,8 @@
   /// Get the vector of assumptions which affect a value from the cache.
   SmallVector<WeakTrackingVH, 1> &getOrInsertAffectedValues(Value *V);
 
-  /// Copy affected values in the cache for OV to be affected values for NV.
-  void copyAffectedValuesInCache(Value *OV, Value *NV);
+  /// Move affected values in the cache for OV to be affected values for NV.
+  void transferAffectedValuesInCache(Value *OV, Value *NV);
 
   /// Flag tracking whether we have scanned the function yet.
   ///
Index: llvm/lib/Analysis/AssumptionCache.cpp
===================================================================
--- llvm/lib/Analysis/AssumptionCache.cpp
+++ llvm/lib/Analysis/AssumptionCache.cpp
@@ -140,7 +140,7 @@
   // 'this' now dangles!
 }
 
-void AssumptionCache::copyAffectedValuesInCache(Value *OV, Value *NV) {
+void AssumptionCache::transferAffectedValuesInCache(Value *OV, Value *NV) {
   auto &NAVV = getOrInsertAffectedValues(NV);
   auto AVI = AffectedValues.find(OV);
   if (AVI == AffectedValues.end())
@@ -149,6 +149,7 @@
   for (auto &A : AVI->second)
     if (std::find(NAVV.begin(), NAVV.end(), A) == NAVV.end())
       NAVV.push_back(A);
+  AffectedValues.erase(OV);
 }
 
 void AssumptionCache::AffectedValueCallbackVH::allUsesReplacedWith(Value *NV) {
@@ -157,7 +158,7 @@
 
   // Any assumptions that affected this value now affect the new value.
 
-  AC->copyAffectedValuesInCache(getValPtr(), NV);
+  AC->transferAffectedValuesInCache(getValPtr(), NV);
   // 'this' now might dangle! If the AffectedValues map was resized to add an
   // entry for NV then this object might have been destroyed in favor of some
   // copy in the grown map.