llvm-project/llvm/lib/CodeGen/AntiDepBreaker.h

75 lines
2.6 KiB
C++

//=- 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"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include <map>
namespace llvm {
/// AntiDepBreaker - This class works into conjunction with the
/// post-RA scheduler to rename registers to break register
/// anti-dependencies.
class AntiDepBreaker {
public:
typedef SmallSet<unsigned, 4> AntiDepRegSet;
typedef SmallVector<unsigned, 4> AntiDepRegVector;
typedef std::map<SUnit *, AntiDepRegVector> CandidateMap;
virtual ~AntiDepBreaker();
/// GetMaxTrials - Return the maximum number of anti-dependence
/// breaking attempts that will be made for a block.
virtual unsigned GetMaxTrials() =0;
/// NeedCandidates - Return true if the schedule must provide
/// candidates with BreakAntiDependencies().
virtual bool NeedCandidates() =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,
CandidateMap& Candidates,
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