Reapply 124301


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124339 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 4c9158a..2d7178b 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -539,8 +539,12 @@
                     SmallVector<std::pair<unsigned, MachineInstr*>, 32> &Orders,
                            SmallSet<unsigned, 8> &Seen) {
   unsigned Order = DAG->GetOrdering(N);
-  if (!Order || !Seen.insert(Order))
+  if (!Order || !Seen.insert(Order)) {
+    // Process any valid SDDbgValues even if node does not have any order
+    // assigned.
+    ProcessSDDbgValues(N, DAG, Emitter, Orders, VRBaseMap, 0);
     return;
+  }
 
   MachineBasicBlock *BB = Emitter.getBlock();
   if (Emitter.getInsertPos() == BB->begin() || BB->back().isPHI()) {