lib/CodeGen/AntiDepBreaker.h

   1 //=- llvm/CodeGen/AntiDepBreaker.h - Anti-Dependence Breaking -*- C++ -*-=//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the AntiDepBreaker class, which implements
  11 // anti-dependence breaking heuristics for post-register-allocation scheduling.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_CODEGEN_ANTIDEPBREAKER_H
  16 #define LLVM_CODEGEN_ANTIDEPBREAKER_H
  17
  18 #include "llvm/CodeGen/MachineBasicBlock.h"
  19 #include "llvm/CodeGen/MachineFrameInfo.h"
  20 #include "llvm/CodeGen/MachineFunction.h"
  21 #include "llvm/CodeGen/MachineRegisterInfo.h"
  22 #include "llvm/CodeGen/ScheduleDAG.h"
  23 #include "llvm/Target/TargetRegisterInfo.h"
  24 #include <vector>
  25
  26 namespace llvm {
  27
  28 /// AntiDepBreaker - This class works into conjunction with the
  29 /// post-RA scheduler to rename registers to break register
  30 /// anti-dependencies.
  31 class AntiDepBreaker {
  32 public:
  33   virtual ~AntiDepBreaker();
  34
  35   /// Start - Initialize anti-dep breaking for a new basic block.
  36   virtual void StartBlock(MachineBasicBlock *BB) =0;
  37
  38   /// BreakAntiDependencies - Identifiy anti-dependencies within a
  39   /// basic-block region and break them by renaming registers. Return
  40   /// the number of anti-dependencies broken.
  41   ///
  42   virtual unsigned BreakAntiDependencies(const std::vector<SUnit>& SUnits,
  43                                 MachineBasicBlock::iterator Begin,
  44                                 MachineBasicBlock::iterator End,
  45                                 unsigned InsertPosIndex) =0;
  46
  47   /// Observe - Update liveness information to account for the current
  48   /// instruction, which will not be scheduled.
  49   ///
  50   virtual void Observe(MachineInstr *MI, unsigned Count,
  51                        unsigned InsertPosIndex) =0;
  52
  53   /// Finish - Finish anti-dep breaking for a basic block.
  54   virtual void FinishBlock() =0;
  55 };
  56
  57 }
  58
  59 #endif