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diff --git a/lib/CodeGen/AntiDepBreaker.h b/lib/CodeGen/AntiDepBreaker.h
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+//=- llvm/CodeGen/AntiDepBreaker.h - Anti-Dependence Breaking -*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the AntiDepBreaker class, which implements
+// anti-dependence breaking heuristics for post-register-allocation scheduling.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_ANTIDEPBREAKER_H
+#define LLVM_CODEGEN_ANTIDEPBREAKER_H
+
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+
+namespace llvm {
+
+/// AntiDepBreaker - This class works into conjunction with the
+/// post-RA scheduler to rename registers to break register
+/// anti-dependencies.
+class AntiDepBreaker {
+public:
+  virtual ~AntiDepBreaker();
+
+  /// GetMaxTrials - Return the maximum number of anti-dependence
+  /// breaking attempts that will be made for a block.
+  virtual unsigned GetMaxTrials() =0;
+
+  /// Start - Initialize anti-dep breaking for a new basic block.
+  virtual void StartBlock(MachineBasicBlock *BB) =0;
+
+  /// BreakAntiDependencies - Identifiy anti-dependencies within a
+  /// basic-block region and break them by renaming registers. Return
+  /// the number of anti-dependencies broken.
+  ///
+  virtual unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits,
+                                         MachineBasicBlock::iterator& Begin,
+                                         MachineBasicBlock::iterator& End,
+                                         unsigned InsertPosIndex) =0;
+  
+  /// Observe - Update liveness information to account for the current
+  /// instruction, which will not be scheduled.
+  ///
+  virtual void Observe(MachineInstr *MI, unsigned Count,
+                       unsigned InsertPosIndex) =0;
+  
+  /// Finish - Finish anti-dep breaking for a basic block.
+  virtual void FinishBlock() =0;
+};
+
+}
+
+#endif