Stub out a PostMachineScheduler pass.

Placeholder and boilerplate for a PostRA MachineScheduler pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198120 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/Passes.h

@@ -207,9 +207,9 @@ public:
   /// Fully developed targets will not generally override this.
   virtual void addMachinePasses();
 
-  /// createTargetScheduler - Create an instance of ScheduleDAGInstrs to be run
-  /// within the standard MachineScheduler pass for this function and target at
-  /// the current optimization level.
+  /// Create an instance of ScheduleDAGInstrs to be run within the standard
+  /// MachineScheduler pass for this function and target at the current
+  /// optimization level.
   ///
   /// This can also be used to plug a new MachineSchedStrategy into an instance
   /// of the standard ScheduleDAGMI:
@@ -221,6 +221,13 @@ public:
     return 0;
   }
 
+  /// Similar to createMachineScheduler but used when postRA machine scheduling
+  /// is enabled.
+  virtual ScheduleDAGInstrs *
+  createPostMachineScheduler(MachineSchedContext *C) const {
+    return 0;
+  }
+
 protected:
   // Helper to verify the analysis is really immutable.
   void setOpt(bool &Opt, bool Val);
@@ -403,6 +410,9 @@ namespace llvm {
   /// MachineScheduler - This pass schedules machine instructions.
   extern char &MachineSchedulerID;
 
+  /// PostMachineScheduler - This pass schedules machine instructions postRA.
+  extern char &PostMachineSchedulerID;
+
   /// SpillPlacement analysis. Suggest optimal placement of spill code between
   /// basic blocks.
   extern char &SpillPlacementID;