Added MachineSchedPolicy.

Allow subtargets to customize the generic scheduling strategy.
This is convenient for targets that don't need to add new heuristics
by specializing the strategy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190176 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetSubtargetInfo.h b/include/llvm/Target/TargetSubtargetInfo.h
index 2092aba8a2..37365b2a9c 100644
--- a/include/llvm/Target/TargetSubtargetInfo.h
+++ b/include/llvm/Target/TargetSubtargetInfo.h
@@ -25,6 +25,7 @@ class SDep;
 class SUnit;
 class TargetRegisterClass;
 class TargetSchedModel;
+struct MachineSchedPolicy;
 template <typename T> class SmallVectorImpl;
 
 //===----------------------------------------------------------------------===//
@@ -62,6 +63,16 @@ public:
   /// scheduler. It does not yet disable the postRA scheduler.
   virtual bool enableMachineScheduler() const;
 
+  /// \brief Override generic scheduling policy within a region.
+  ///
+  /// This is a convenient way for targets that don't provide any custom
+  /// scheduling heuristics (no custom MachineSchedStrategy) to make
+  /// changes to the generic scheduling policy.
+  virtual void overrideSchedPolicy(MachineSchedPolicy &Policy,
+                                   MachineInstr *begin,
+                                   MachineInstr *end,
+                                   unsigned NumRegionInstrs) const {}
+
   // enablePostRAScheduler - If the target can benefit from post-regalloc
   // scheduling and the specified optimization level meets the requirement
   // return true to enable post-register-allocation scheduling. In