| //=- llvm/CodeGen/CriticalAntiDepBreaker.h - Anti-Dep Support -*- 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 CriticalAntiDepBreaker class, which |
| // implements register anti-dependence breaking along a blocks |
| // critical path during post-RA scheduler. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_CRITICALANTIDEPBREAKER_H |
| #define LLVM_CODEGEN_CRITICALANTIDEPBREAKER_H |
| |
| #include "AntiDepBreaker.h" |
| #include "llvm/ADT/BitVector.h" |
| #include "llvm/CodeGen/MachineBasicBlock.h" |
| #include "llvm/CodeGen/MachineFrameInfo.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/RegisterClassInfo.h" |
| #include "llvm/CodeGen/ScheduleDAG.h" |
| #include <map> |
| |
| namespace llvm { |
| class RegisterClassInfo; |
| class TargetInstrInfo; |
| class TargetRegisterInfo; |
| |
| class CriticalAntiDepBreaker : public AntiDepBreaker { |
| MachineFunction& MF; |
| MachineRegisterInfo &MRI; |
| const TargetInstrInfo *TII; |
| const TargetRegisterInfo *TRI; |
| const RegisterClassInfo &RegClassInfo; |
| |
| /// AllocatableSet - The set of allocatable registers. |
| /// We'll be ignoring anti-dependencies on non-allocatable registers, |
| /// because they may not be safe to break. |
| const BitVector AllocatableSet; |
| |
| /// Classes - For live regs that are only used in one register class in a |
| /// live range, the register class. If the register is not live, the |
| /// corresponding value is null. If the register is live but used in |
| /// multiple register classes, the corresponding value is -1 casted to a |
| /// pointer. |
| std::vector<const TargetRegisterClass*> Classes; |
| |
| /// RegRefs - Map registers to all their references within a live range. |
| std::multimap<unsigned, MachineOperand *> RegRefs; |
| typedef std::multimap<unsigned, MachineOperand *>::const_iterator |
| RegRefIter; |
| |
| /// KillIndices - The index of the most recent kill (proceding bottom-up), |
| /// or ~0u if the register is not live. |
| std::vector<unsigned> KillIndices; |
| |
| /// DefIndices - The index of the most recent complete def (proceding bottom |
| /// up), or ~0u if the register is live. |
| std::vector<unsigned> DefIndices; |
| |
| /// KeepRegs - A set of registers which are live and cannot be changed to |
| /// break anti-dependencies. |
| BitVector KeepRegs; |
| |
| public: |
| CriticalAntiDepBreaker(MachineFunction& MFi, const RegisterClassInfo&); |
| ~CriticalAntiDepBreaker(); |
| |
| /// Start - Initialize anti-dep breaking for a new basic block. |
| void StartBlock(MachineBasicBlock *BB); |
| |
| /// BreakAntiDependencies - Identifiy anti-dependencies along the critical |
| /// path |
| /// of the ScheduleDAG and break them by renaming registers. |
| /// |
| unsigned BreakAntiDependencies(const std::vector<SUnit>& SUnits, |
| MachineBasicBlock::iterator Begin, |
| MachineBasicBlock::iterator End, |
| unsigned InsertPosIndex, |
| DbgValueVector &DbgValues); |
| |
| /// Observe - Update liveness information to account for the current |
| /// instruction, which will not be scheduled. |
| /// |
| void Observe(MachineInstr *MI, unsigned Count, unsigned InsertPosIndex); |
| |
| /// Finish - Finish anti-dep breaking for a basic block. |
| void FinishBlock(); |
| |
| private: |
| void PrescanInstruction(MachineInstr *MI); |
| void ScanInstruction(MachineInstr *MI, unsigned Count); |
| bool isNewRegClobberedByRefs(RegRefIter RegRefBegin, |
| RegRefIter RegRefEnd, |
| unsigned NewReg); |
| unsigned findSuitableFreeRegister(RegRefIter RegRefBegin, |
| RegRefIter RegRefEnd, |
| unsigned AntiDepReg, |
| unsigned LastNewReg, |
| const TargetRegisterClass *RC); |
| }; |
| } |
| |
| #endif |