diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -8305,10 +8305,16 @@
 /// else return NULL.
 SDNode *SelectionDAG::getNodeIfExists(unsigned Opcode, SDVTList VTList,
                                       ArrayRef<SDValue> Ops) {
-  SDNodeFlags Flags;
   if (Inserter)
-    Flags = Inserter->getFlags();
-  return getNodeIfExists(Opcode, VTList, Ops, Flags);
+    return getNodeIfExists(Opcode, VTList, Ops, Inserter->getFlags());
+  if (VTList.VTs[VTList.NumVTs - 1] != MVT::Glue) {
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, Opcode, VTList, Ops);
+    void *IP = nullptr;
+    if (SDNode *E = FindNodeOrInsertPos(ID, SDLoc(), IP))
+      return E;
+  }
+  return nullptr;
 }
 
 SDNode *SelectionDAG::getNodeIfExists(unsigned Opcode, SDVTList VTList,
diff --git a/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll b/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll
--- a/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll
+++ b/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll
@@ -10,7 +10,7 @@
   ; CHECK:   liveins: $x3, $x4
   ; CHECK:   [[COPY:%[0-9]+]]:g8rc = COPY $x4
   ; CHECK:   [[COPY1:%[0-9]+]]:g8rc = COPY $x3
-  ; CHECK:   [[SUBF8_:%[0-9]+]]:g8rc = SUBF8 [[COPY1]], [[COPY]]
+  ; CHECK:   [[SUBF8_:%[0-9]+]]:g8rc = nsw SUBF8 [[COPY1]], [[COPY]]
   %c = sub nsw i64 %b, %a
   call void @foo(i64 %c)
   %d = icmp slt i64 %a, %b