AntiDepBreaker.h revision 199989 
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
26namespace llvm {
27
28/// AntiDepBreaker - This class works into conjunction with the
29/// post-RA scheduler to rename registers to break register
30/// anti-dependencies.
31class AntiDepBreaker {
32public:
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(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
60