| //=- 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_LIB_CODEGEN_ANTIDEPBREAKER_H |
| #define LLVM_LIB_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 <vector> |
| |
| namespace llvm { |
| |
| /// This class works in conjunction with the post-RA scheduler to rename |
| /// registers to break register anti-dependencies (WAR hazards). |
| class LLVM_LIBRARY_VISIBILITY AntiDepBreaker { |
| public: |
| typedef std::vector<std::pair<MachineInstr *, MachineInstr *> > |
| DbgValueVector; |
| |
| virtual ~AntiDepBreaker(); |
| |
| /// Initialize anti-dep breaking for a new basic block. |
| virtual void StartBlock(MachineBasicBlock *BB) =0; |
| |
| /// Identifiy anti-dependencies within a basic-block region and break them by |
| /// renaming registers. Return the number of anti-dependencies broken. |
| virtual unsigned BreakAntiDependencies(const std::vector<SUnit>& SUnits, |
| MachineBasicBlock::iterator Begin, |
| MachineBasicBlock::iterator End, |
| unsigned InsertPosIndex, |
| DbgValueVector &DbgValues) = 0; |
| |
| /// 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 anti-dep breaking for a basic block. |
| virtual void FinishBlock() =0; |
| |
| /// Update DBG_VALUE if dependency breaker is updating |
| /// other machine instruction to use NewReg. |
| void UpdateDbgValue(MachineInstr *MI, unsigned OldReg, unsigned NewReg) { |
| assert (MI->isDebugValue() && "MI is not DBG_VALUE!"); |
| if (MI && MI->getOperand(0).isReg() && MI->getOperand(0).getReg() == OldReg) |
| MI->getOperand(0).setReg(NewReg); |
| } |
| }; |
| |
| } |
| |
| #endif |