Index: llvm/include/llvm/Analysis/InstructionSimplify.h
===================================================================
--- llvm/include/llvm/Analysis/InstructionSimplify.h
+++ llvm/include/llvm/Analysis/InstructionSimplify.h
@@ -118,6 +118,11 @@
     Copy.CxtI = I;
     return Copy;
   }
+  SimplifyQuery getWithoutUndef() const {
+    SimplifyQuery Copy(*this);
+    Copy.CanUseUndef = false;
+    return Copy;
+  }
 };
 
 // NOTE: the explicit multiple argument versions of these functions are
Index: llvm/lib/Analysis/InstructionSimplify.cpp
===================================================================
--- llvm/lib/Analysis/InstructionSimplify.cpp
+++ llvm/lib/Analysis/InstructionSimplify.cpp
@@ -238,10 +238,12 @@
   if (!B || B->getOpcode() != OpcodeToExpand)
     return nullptr;
   Value *B0 = B->getOperand(0), *B1 = B->getOperand(1);
-  Value *L = SimplifyBinOp(Opcode, B0, OtherOp, Q, MaxRecurse);
+  Value *L = SimplifyBinOp(Opcode, B0, OtherOp, Q.getWithoutUndef(),
+                           MaxRecurse);
   if (!L)
     return nullptr;
-  Value *R = SimplifyBinOp(Opcode, B1, OtherOp, Q, MaxRecurse);
+  Value *R = SimplifyBinOp(Opcode, B1, OtherOp, Q.getWithoutUndef(),
+                           MaxRecurse);
   if (!R)
     return nullptr;