Index: llvm/include/llvm/Transforms/IPO/Attributor.h
===================================================================
--- llvm/include/llvm/Transforms/IPO/Attributor.h
+++ llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -2646,6 +2646,12 @@
     return F.hasPersonalityFn() && !canSimplifyInvokeNoUnwind(&F);
   }
 
+  /// Return if the edge from \p From BB to \p To BB is assumed dead.
+  /// This is specifically useful in AAReachability.
+  virtual bool isEdgeDead(const BasicBlock *From, const BasicBlock *To) const {
+    return false;
+  }
+
   /// See AbstractAttribute::getName()
   const std::string getName() const override { return "AAIsDead"; }
 
Index: llvm/lib/Transforms/IPO/AttributorAttributes.cpp
===================================================================
--- llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -3093,6 +3093,10 @@
   /// See AbstractAttribute::updateImpl(...).
   ChangeStatus updateImpl(Attributor &A) override;
 
+  bool isEdgeDead(const BasicBlock *From, const BasicBlock *To) const override {
+    return !AssumedLiveEdges.count(std::make_pair(From, To));
+  }
+
   /// See AbstractAttribute::trackStatistics()
   void trackStatistics() const override {}
 
@@ -3170,6 +3174,9 @@
   /// Collection of instructions that are known to not transfer control.
   SmallSetVector<const Instruction *, 8> KnownDeadEnds;
 
+  /// Collection of all assumed live edges
+  DenseSet<std::pair<const BasicBlock *, const BasicBlock *>> AssumedLiveEdges;
+
   /// Collection of all assumed live BasicBlocks.
   DenseSet<const BasicBlock *> AssumedLiveBlocks;
 };
@@ -3335,6 +3342,10 @@
                       << UsedAssumedInformation << "\n");
 
     for (const Instruction *AliveSuccessor : AliveSuccessors) {
+      // if successor belongs to different basic block, record the edge.
+      if (I->getParent() != AliveSuccessor->getParent())
+        AssumedLiveEdges.insert(
+            std::make_pair(I->getParent(), AliveSuccessor->getParent()));
       if (!I->isTerminator()) {
         assert(AliveSuccessors.size() == 1 &&
                "Non-terminator expected to have a single successor!");