113 lines
4.2 KiB
C
113 lines
4.2 KiB
C
|
//===- llvm/CodeGen/CriticalAntiDepBreaker.h - Anti-Dep Support -*- C++ -*-===//
|
||
|
|
//
|
||
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
||
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
||
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
||
|
|
//
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
//
|
||
|
|
// This file implements the CriticalAntiDepBreaker class, which
|
||
|
|
// implements register anti-dependence breaking along a blocks
|
||
|
|
// critical path during post-RA scheduler.
|
||
|
|
//
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
|
||
|
|
#ifndef LLVM_LIB_CODEGEN_CRITICALANTIDEPBREAKER_H
|
||
|
|
#define LLVM_LIB_CODEGEN_CRITICALANTIDEPBREAKER_H
|
||
|
|
|
||
|
|
#include "llvm/ADT/BitVector.h"
|
||
|
|
#include "llvm/CodeGen/AntiDepBreaker.h"
|
||
|
|
#include "llvm/Support/Compiler.h"
|
||
|
|
#include <map>
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
namespace llvm {
|
||
|
|
|
||
|
|
class MachineBasicBlock;
|
||
|
|
class MachineFunction;
|
||
|
|
class MachineInstr;
|
||
|
|
class MachineOperand;
|
||
|
|
class MachineRegisterInfo;
|
||
|
|
class RegisterClassInfo;
|
||
|
|
class TargetInstrInfo;
|
||
|
|
class TargetRegisterClass;
|
||
|
|
class TargetRegisterInfo;
|
||
|
|
|
||
|
|
class LLVM_LIBRARY_VISIBILITY CriticalAntiDepBreaker : public AntiDepBreaker {
|
||
|
|
MachineFunction& MF;
|
||
|
|
MachineRegisterInfo &MRI;
|
||
|
|
const TargetInstrInfo *TII;
|
||
|
|
const TargetRegisterInfo *TRI;
|
||
|
|
const RegisterClassInfo &RegClassInfo;
|
||
|
|
|
||
|
|
/// 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;
|
||
|
|
|
||
|
|
/// 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;
|
||
|
|
|
||
|
|
/// Map registers to all their references within a live range.
|
||
|
|
std::multimap<unsigned, MachineOperand *> RegRefs;
|
||
|
|
|
||
|
|
using RegRefIter =
|
||
|
|
std::multimap<unsigned, MachineOperand *>::const_iterator;
|
||
|
|
|
||
|
|
/// The index of the most recent kill (proceeding bottom-up),
|
||
|
|
/// or ~0u if the register is not live.
|
||
|
|
std::vector<unsigned> KillIndices;
|
||
|
|
|
||
|
|
/// The index of the most recent complete def (proceeding
|
||
|
|
/// bottom up), or ~0u if the register is live.
|
||
|
|
std::vector<unsigned> DefIndices;
|
||
|
|
|
||
|
|
/// A set of registers which are live and cannot be changed to
|
||
|
|
/// break anti-dependencies.
|
||
|
|
BitVector KeepRegs;
|
||
|
|
|
||
|
|
public:
|
||
|
|
CriticalAntiDepBreaker(MachineFunction& MFi, const RegisterClassInfo &RCI);
|
||
|
|
~CriticalAntiDepBreaker() override;
|
||
|
|
|
||
|
|
/// Initialize anti-dep breaking for a new basic block.
|
||
|
|
void StartBlock(MachineBasicBlock *BB) override;
|
||
|
|
|
||
|
|
/// 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) override;
|
||
|
|
|
||
|
|
/// Update liveness information to account for the current
|
||
|
|
/// instruction, which will not be scheduled.
|
||
|
|
void Observe(MachineInstr &MI, unsigned Count,
|
||
|
|
unsigned InsertPosIndex) override;
|
||
|
|
|
||
|
|
/// Finish anti-dep breaking for a basic block.
|
||
|
|
void FinishBlock() override;
|
||
|
|
|
||
|
|
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,
|
||
|
|
SmallVectorImpl<unsigned> &Forbid);
|
||
|
|
};
|
||
|
|
|
||
|
|
} // end namespace llvm
|
||
|
|
|
||
|
|
#endif // LLVM_LIB_CODEGEN_CRITICALANTIDEPBREAKER_H
|