X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FCodeGen%2FMachineScheduler.h;h=2003297ff0acda797d6858faa592e142fa351f2c;hb=2c46deb1d07f4588ee70059cdd4c7145f81bc8e8;hp=4bee2171bd1dacb73c412b33815806270d900d61;hpb=40b52bb8f2b4f63f6d99e347af0c48945f9cb4d2;p=oota-llvm.git

diff --git a/include/llvm/CodeGen/MachineScheduler.h b/include/llvm/CodeGen/MachineScheduler.h
index 4bee2171bd1..2003297ff0a 100644
--- a/include/llvm/CodeGen/MachineScheduler.h
+++ b/include/llvm/CodeGen/MachineScheduler.h
@@ -101,12 +101,40 @@ public:
 
 class ScheduleDAGMI;
 
+/// Define a generic scheduling policy for targets that don't provide their own
+/// MachineSchedStrategy. This can be overriden for each scheduling region
+/// before building the DAG.
+struct MachineSchedPolicy {
+  // Allow the scheduler to disable register pressure tracking.
+  bool ShouldTrackPressure;
+
+  // Allow the scheduler to force top-down or bottom-up scheduling. If neither
+  // is true, the scheduler runs in both directions and converges.
+  bool OnlyTopDown;
+  bool OnlyBottomUp;
+
+  MachineSchedPolicy():
+    ShouldTrackPressure(false), OnlyTopDown(false), OnlyBottomUp(false) {}
+};
+
 /// MachineSchedStrategy - Interface to the scheduling algorithm used by
 /// ScheduleDAGMI.
+///
+/// Initialization sequence:
+///   initPolicy -> shouldTrackPressure -> initialize(DAG) -> registerRoots
 class MachineSchedStrategy {
 public:
   virtual ~MachineSchedStrategy() {}
 
+  /// Optionally override the per-region scheduling policy.
+  virtual void initPolicy(MachineBasicBlock::iterator Begin,
+                          MachineBasicBlock::iterator End,
+                          unsigned NumRegionInstrs) {}
+
+  /// Check if pressure tracking is needed before building the DAG and
+  /// initializing this strategy. Called after initPolicy.
+  virtual bool shouldTrackPressure() const { return true; }
+
   /// Initialize the strategy after building the DAG for a new region.
   virtual void initialize(ScheduleDAGMI *DAG) = 0;
 
@@ -271,8 +299,8 @@ public:
 
   virtual ~ScheduleDAGMI();
 
-  /// Return true if register pressure tracking is enabled.
-  bool shouldTrackPressure() const { return ShouldTrackPressure; }
+  /// \brief Return true if register pressure tracking is enabled.
+  bool isTrackingPressure() const { return ShouldTrackPressure; }
 
   /// Add a postprocessing step to the DAG builder.
   /// Mutations are applied in the order that they are added after normal DAG
@@ -385,7 +413,8 @@ protected:
 
   void updatePressureDiffs(ArrayRef<unsigned> LiveUses);
 
-  void updateScheduledPressure(const std::vector<unsigned> &NewMaxPressure);
+  void updateScheduledPressure(const SUnit *SU,
+                               const std::vector<unsigned> &NewMaxPressure);
 
   bool checkSchedLimit();