diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 456966b..5c891e9 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -56,6 +56,7 @@
   namespace Sched {
     enum Preference {
       None,             // No preference
+      Source,           // Follow source order.
       RegPressure,      // Scheduling for lowest register pressure.
       Hybrid,           // Scheduling for both latency and register pressure.
       ILP               // Scheduling for ILP in low register pressure mode.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index bfb6dfa..9f39699 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -218,7 +218,8 @@
                                              CodeGenOpt::Level OptLevel) {
     const TargetLowering &TLI = IS->getTargetLowering();
 
-    if (OptLevel == CodeGenOpt::None)
+    if (OptLevel == CodeGenOpt::None ||
+        TLI.getSchedulingPreference() == Sched::Source)
       return createSourceListDAGScheduler(IS, OptLevel);
     if (TLI.getSchedulingPreference() == Sched::RegPressure)
       return createBURRListDAGScheduler(IS, OptLevel);