Index: lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- lib/Transforms/InstCombine/InstructionCombining.cpp
+++ lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -330,6 +330,9 @@
             ClearSubclassDataAfterReassociation(I);
           }
 
+          Worklist.Add(Op0);
+          if (auto *CI = dyn_cast<Instruction>(C))
+            Worklist.Add(CI);
           Changed = true;
           ++NumReassoc;
           continue;
@@ -350,6 +353,9 @@
           // Conservatively clear the optional flags, since they may not be
           // preserved by the reassociation.
           ClearSubclassDataAfterReassociation(I);
+          if (auto *AI = dyn_cast<Instruction>(A))
+            Worklist.Add(AI);
+          Worklist.Add(Op1);
           Changed = true;
           ++NumReassoc;
           continue;
@@ -378,6 +384,9 @@
           // Conservatively clear the optional flags, since they may not be
           // preserved by the reassociation.
           ClearSubclassDataAfterReassociation(I);
+          Worklist.Add(Op0);
+          if (auto *CI = dyn_cast<Instruction>(C))
+            Worklist.Add(CI);
           Changed = true;
           ++NumReassoc;
           continue;
@@ -398,6 +407,9 @@
           // Conservatively clear the optional flags, since they may not be
           // preserved by the reassociation.
           ClearSubclassDataAfterReassociation(I);
+          if (auto *AI = dyn_cast<Instruction>(A))
+            Worklist.Add(AI);
+          Worklist.Add(Op1);
           Changed = true;
           ++NumReassoc;
           continue;
@@ -426,6 +438,8 @@
         // Conservatively clear the optional flags, since they may not be
         // preserved by the reassociation.
         ClearSubclassDataAfterReassociation(I);
+        Worklist.Add(Op0);
+        Worklist.Add(Op1);
 
         Changed = true;
         continue;