diff --git a/llvm/include/llvm/CodeGen/DFAPacketizer.h b/llvm/include/llvm/CodeGen/DFAPacketizer.h
--- a/llvm/include/llvm/CodeGen/DFAPacketizer.h
+++ b/llvm/include/llvm/CodeGen/DFAPacketizer.h
@@ -26,6 +26,8 @@
 #define LLVM_CODEGEN_DFAPACKETIZER_H
 
 #include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/ScheduleDAGInstrs.h"
+#include "llvm/CodeGen/ScheduleDAGMutation.h"
 #include "llvm/Support/Automaton.h"
 #include <cstdint>
 #include <map>
@@ -35,7 +37,6 @@
 
 namespace llvm {
 
-class DefaultVLIWScheduler;
 class ScheduleDAGMutation;
 class InstrItineraryData;
 class MachineFunction;
@@ -45,6 +46,30 @@
 class SUnit;
 class TargetInstrInfo;
 
+// This class extends ScheduleDAGInstrs and overrides the schedule method
+// to build the dependence graph.
+class DefaultVLIWScheduler : public ScheduleDAGInstrs {
+private:
+  AAResults *AA;
+  /// Ordered list of DAG postprocessing steps.
+  std::vector<std::unique_ptr<ScheduleDAGMutation>> Mutations;
+
+public:
+  DefaultVLIWScheduler(MachineFunction &MF, MachineLoopInfo &MLI,
+                       AAResults *AA);
+
+  // Actual scheduling work.
+  void schedule() override;
+
+  /// DefaultVLIWScheduler takes ownership of the Mutation object.
+  void addMutation(std::unique_ptr<ScheduleDAGMutation> Mutation) {
+    Mutations.push_back(std::move(Mutation));
+  }
+
+protected:
+  void postprocessDAG();
+};
+
 class DFAPacketizer {
 private:
   const InstrItineraryData *InstrItins;
diff --git a/llvm/lib/CodeGen/DFAPacketizer.cpp b/llvm/lib/CodeGen/DFAPacketizer.cpp
--- a/llvm/lib/CodeGen/DFAPacketizer.cpp
+++ b/llvm/lib/CodeGen/DFAPacketizer.cpp
@@ -29,8 +29,6 @@
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBundle.h"
 #include "llvm/CodeGen/ScheduleDAG.h"
-#include "llvm/CodeGen/ScheduleDAGInstrs.h"
-#include "llvm/CodeGen/ScheduleDAGMutation.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/MC/MCInstrDesc.h"
@@ -98,34 +96,6 @@
   return RS[InstIdx] ^ RS[InstIdx - 1];
 }
 
-namespace llvm {
-
-// This class extends ScheduleDAGInstrs and overrides the schedule method
-// to build the dependence graph.
-class DefaultVLIWScheduler : public ScheduleDAGInstrs {
-private:
-  AAResults *AA;
-  /// Ordered list of DAG postprocessing steps.
-  std::vector<std::unique_ptr<ScheduleDAGMutation>> Mutations;
-
-public:
-  DefaultVLIWScheduler(MachineFunction &MF, MachineLoopInfo &MLI,
-                       AAResults *AA);
-
-  // Actual scheduling work.
-  void schedule() override;
-
-  /// DefaultVLIWScheduler takes ownership of the Mutation object.
-  void addMutation(std::unique_ptr<ScheduleDAGMutation> Mutation) {
-    Mutations.push_back(std::move(Mutation));
-  }
-
-protected:
-  void postprocessDAG();
-};
-
-} // end namespace llvm
-
 DefaultVLIWScheduler::DefaultVLIWScheduler(MachineFunction &MF,
                                            MachineLoopInfo &MLI,
                                            AAResults *AA)