List of registers defined and used by a machine instruction. More...
#include "llvm/CodeGen/RegisterPressure.h"
Public Member Functions | |
| LLVM_ABI void | collect (const MachineInstr &MI, const TargetRegisterInfo &TRI, const MachineRegisterInfo &MRI, bool TrackLaneMasks, bool IgnoreDead) |
Analyze the given instruction MI and fill in the Uses, Defs and DeadDefs list based on the MachineOperand flags. | |
| LLVM_ABI void | detectDeadDefs (const MachineInstr &MI, LiveIntervals &LIS, const MachineRegisterInfo &MRI) |
Use liveness information to find dead defs at MI's dead slot not marked with a dead flag and move them to the DeadDefs vector. | |
| LLVM_ABI void | adjustLaneLiveness (LiveIntervals &LIS, const MachineRegisterInfo &MRI, SlotIndex Pos) |
Use liveness information to find out which uses/defs are partially undefined/dead at Pos and adjust the VRegMaskOrUnits accordingly. | |
| LLVM_ABI void | adjustLaneLiveness (LiveIntervals &LIS, const MachineRegisterInfo &MRI, MachineInstr &MI) |
Use liveness information to find out which uses/defs are partially undefined/dead at the MI's position and adjust the VRegMaskOrUnits accordingly. | |
Static Public Member Functions | |
| static LLVM_ABI void | restoreLivenessFlags (MachineInstr &MI, const TargetRegisterInfo &TRI, const MachineRegisterInfo &MRI, LiveIntervals &LIS, bool TrackLaneMasks=true, ArrayRef< Register > OnlyRegs={}) |
Clear potentially-stale read-undef flags on the defs of MI, then recompute them from LIS. | |
Public Attributes | |
| SmallVector< VRegMaskOrUnit, 8 > | Uses |
| List of virtual registers and register units read by the instruction. | |
| SmallVector< VRegMaskOrUnit, 8 > | Defs |
| List of virtual registers and register units defined by the instruction which are not dead. | |
| SmallVector< VRegMaskOrUnit, 8 > | DeadDefs |
| List of virtual registers and register units defined by the instruction but dead. | |
Detailed Description
List of registers defined and used by a machine instruction.
Definition at line 167 of file RegisterPressure.h.
Member Function Documentation
◆ adjustLaneLiveness() [1/2]
| void RegisterOperands::adjustLaneLiveness | ( | LiveIntervals & | LIS, |
| const MachineRegisterInfo & | MRI, | ||
| MachineInstr & | MI ) |
Use liveness information to find out which uses/defs are partially undefined/dead at the MI's position and adjust the VRegMaskOrUnits accordingly.
Missing read-undef and dead flags are added to MI.
Definition at line 603 of file RegisterPressure.cpp.
References llvm::VirtRegOrUnit::asVirtualReg(), llvm::SmallVectorTemplateCommon< T, typename >::back(), DeadDefs, Defs, llvm::SlotIndex::getDeadSlot(), llvm::LiveIntervals::getInstructionIndex(), llvm::LiveIntervals::getInterval(), getLiveLanesAt(), llvm::MachineRegisterInfo::getTargetRegisterInfo(), I, llvm::VirtRegOrUnit::isVirtualReg(), MI, llvm::LaneBitmask::none(), P, llvm::LiveRange::segments, and TRI.
◆ adjustLaneLiveness() [2/2]
| void RegisterOperands::adjustLaneLiveness | ( | LiveIntervals & | LIS, |
| const MachineRegisterInfo & | MRI, | ||
| SlotIndex | Pos ) |
Use liveness information to find out which uses/defs are partially undefined/dead at Pos and adjust the VRegMaskOrUnits accordingly.
Definition at line 592 of file RegisterPressure.cpp.
References Defs, llvm::SlotIndex::getBaseIndex(), llvm::SlotIndex::getDeadSlot(), getLiveLanesAt(), and I.
Referenced by llvm::RegPressureTracker::advance(), llvm::ScheduleDAGDependencyBuilder::buildDeps(), llvm::GCNDownwardRPTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), llvm::RegPressureTracker::recede(), restoreLivenessFlags(), and llvm::ScheduleDAGMILive::scheduleMI().
◆ collect()
| void RegisterOperands::collect | ( | const MachineInstr & | MI, |
| const TargetRegisterInfo & | TRI, | ||
| const MachineRegisterInfo & | MRI, | ||
| bool | TrackLaneMasks, | ||
| bool | IgnoreDead ) |
Analyze the given instruction MI and fill in the Uses, Defs and DeadDefs list based on the MachineOperand flags.
Definition at line 567 of file RegisterPressure.cpp.
References Collector, MI, and TRI.
Referenced by llvm::RegPressureTracker::advance(), llvm::ScheduleDAGDependencyBuilder::buildDeps(), llvm::GCNDownwardRPTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), llvm::RegPressureTracker::recede(), restoreLivenessFlags(), llvm::ScheduleDAGMILive::scheduleMI(), and llvm::PPCInstrInfo::shouldReduceRegisterPressure().
◆ detectDeadDefs()
| void RegisterOperands::detectDeadDefs | ( | const MachineInstr & | MI, |
| LiveIntervals & | LIS, | ||
| const MachineRegisterInfo & | MRI ) |
Use liveness information to find dead defs at MI's dead slot not marked with a dead flag and move them to the DeadDefs vector.
This only considers the merged live interval for defs, not the per-lane sub-ranges.
Definition at line 578 of file RegisterPressure.cpp.
References Defs, llvm::SlotIndex::getDeadSlot(), llvm::LiveIntervals::getInstructionIndex(), getLiveLanesAt(), I, and MI.
Referenced by llvm::ScheduleDAGDependencyBuilder::buildDeps(), llvm::RegPressureTracker::bumpUpwardPressure(), llvm::RegPressureTracker::recede(), restoreLivenessFlags(), and llvm::ScheduleDAGMILive::scheduleMI().
◆ restoreLivenessFlags()
|
static |
Clear potentially-stale read-undef flags on the defs of MI, then recompute them from LIS.
The clear must come first because adjustLaneLiveness only adds flags. When OnlyRegs is non-empty, only subregister defs of those virtual registers are cleared (and the recompute is skipped when MI has none); otherwise all defs are cleared. This is used after moving an already-scheduled instruction, which can invalidate the flags set for its previous position.
Definition at line 641 of file RegisterPressure.cpp.
References adjustLaneLiveness(), assert(), collect(), detectDeadDefs(), llvm::ArrayRef< T >::empty(), llvm::MachineOperand::getReg(), llvm::MachineOperand::getSubReg(), llvm::is_contained(), llvm::Register::isVirtual(), MI, llvm::MachineOperand::setIsUndef(), and TRI.
Referenced by llvm::GCNSchedStage::modifyRegionSchedule(), llvm::GCNIterativeScheduler::restoreRegionLivenessFlags(), and llvm::GCNIterativeScheduler::scheduleRegion().
Member Data Documentation
◆ DeadDefs
| SmallVector<VRegMaskOrUnit, 8> llvm::RegisterOperands::DeadDefs |
List of virtual registers and register units defined by the instruction but dead.
Dead definitions should not necessarily be marked with a dead flag. In this context a dead definition is just a definition which doesn't define any register lane that remains live after the defining instruction.
Definition at line 179 of file RegisterPressure.h.
Referenced by adjustLaneLiveness(), llvm::RegPressureTracker::advance(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), and llvm::RegPressureTracker::recede().
◆ Defs
| SmallVector<VRegMaskOrUnit, 8> llvm::RegisterOperands::Defs |
List of virtual registers and register units defined by the instruction which are not dead.
Definition at line 173 of file RegisterPressure.h.
Referenced by llvm::PressureDiffs::addInstruction(), adjustLaneLiveness(), adjustLaneLiveness(), llvm::RegPressureTracker::advance(), llvm::GCNDownwardRPTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), detectDeadDefs(), and llvm::RegPressureTracker::recede().
◆ Uses
| SmallVector<VRegMaskOrUnit, 8> llvm::RegisterOperands::Uses |
List of virtual registers and register units read by the instruction.
Definition at line 170 of file RegisterPressure.h.
Referenced by llvm::PressureDiffs::addInstruction(), llvm::RegPressureTracker::advance(), llvm::GCNDownwardRPTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), and llvm::RegPressureTracker::recede().
The documentation for this class was generated from the following files:
- include/llvm/CodeGen/RegisterPressure.h
- lib/CodeGen/RegisterPressure.cpp
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