LLVM 22.0.0git
Static Public Attributes | Protected Member Functions | Protected Attributes | Static Protected Attributes | List of all members
llvm::RegAllocBase Class Referenceabstract

RegAllocBase provides the register allocation driver and interface that can be extended to add interesting heuristics. More...

#include "CodeGen/RegAllocBase.h"

Inheritance diagram for llvm::RegAllocBase:
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Static Public Attributes

static bool VerifyEnabled = false
 VerifyEnabled - True when -verify-regalloc is given.
 

Protected Member Functions

 RegAllocBase (const RegAllocFilterFunc F=nullptr)
 
virtual ~RegAllocBase ()=default
 
void init (VirtRegMap &vrm, LiveIntervals &lis, LiveRegMatrix &mat)
 
bool shouldAllocateRegister (Register Reg)
 Get whether a given register should be allocated.
 
void allocatePhysRegs ()
 
virtual void postOptimization ()
 
void cleanupFailedVReg (Register FailedVReg, MCRegister PhysReg, SmallVectorImpl< Register > &SplitRegs)
 Perform cleanups on registers that failed to allocate.
 
virtual Spiller & spiller ()=0
 
virtual void enqueueImpl (const LiveInterval *LI)=0
 enqueue - Add VirtReg to the priority queue of unassigned registers.
 
void enqueue (const LiveInterval *LI)
 enqueue - Add VirtReg to the priority queue of unassigned registers.
 
virtual const LiveInterval * dequeue ()=0
 dequeue - Return the next unassigned register, or NULL.
 
virtual MCRegister selectOrSplit (const LiveInterval &VirtReg, SmallVectorImpl< Register > &splitLVRs)=0
 
MCPhysReg getErrorAssignment (const TargetRegisterClass &RC, const MachineInstr *CtxMI=nullptr)
 Query a physical register to use as a filler in contexts where the allocation has failed.
 
virtual void aboutToRemoveInterval (const LiveInterval &LI)
 Method called when the allocator is about to remove a LiveInterval.
 

Protected Attributes

const TargetRegisterInfo * TRI = nullptr
 
MachineRegisterInfo * MRI = nullptr
 
VirtRegMap * VRM = nullptr
 
LiveIntervals * LIS = nullptr
 
LiveRegMatrix * Matrix = nullptr
 
RegisterClassInfo RegClassInfo
 
SmallPtrSet< MachineInstr *, 32 > DeadRemats
 Inst which is a def of an original reg and whose defs are already all dead after remat is saved in DeadRemats.
 
SmallSet< Register, 2 > FailedVRegs
 

Static Protected Attributes

static const char TimerGroupName [] = "regalloc"
 
static const char TimerGroupDescription [] = "Register Allocation"
 

Detailed Description

RegAllocBase provides the register allocation driver and interface that can be extended to add interesting heuristics.

Register allocators must override the selectOrSplit() method to implement live range splitting. They must also override enqueue/dequeue to provide an assignment order.

Definition at line 63 of file RegAllocBase.h.

Constructor & Destructor Documentation

◆ RegAllocBase()

llvm::RegAllocBase::RegAllocBase ( const RegAllocFilterFunc  F = nullptr)
inlineprotected

Definition at line 86 of file RegAllocBase.h.

◆ ~RegAllocBase()

virtual llvm::RegAllocBase::~RegAllocBase ( )
protectedvirtualdefault

Member Function Documentation

◆ aboutToRemoveInterval()

virtual void llvm::RegAllocBase::aboutToRemoveInterval ( const LiveInterval &  LI)
inlineprotectedvirtual

Method called when the allocator is about to remove a LiveInterval.

Reimplemented in llvm::RAGreedy.

Definition at line 144 of file RegAllocBase.h.

Referenced by allocatePhysRegs().

◆ allocatePhysRegs()

void RegAllocBase::allocatePhysRegs ( )
protected

Definition at line 87 of file RegAllocBase.cpp.

References aboutToRemoveInterval(), assert(), llvm::LiveRegMatrix::assign(), cleanupFailedVReg(), llvm::dbgs(), dequeue(), llvm::LiveRange::empty(), enqueue(), getErrorAssignment(), llvm::LiveIntervals::getInterval(), llvm::MachineRegisterInfo::getRegClass(), llvm::TargetRegisterInfo::getRegClassName(), llvm::LiveIntervals::hasInterval(), llvm::VirtRegMap::hasPhys(), llvm::LiveRegMatrix::invalidateVirtRegs(), llvm::Register::isVirtual(), LIS, LLVM_DEBUG, Matrix, MI, MRI, llvm::LiveInterval::reg(), llvm::MachineRegisterInfo::reg_instructions(), llvm::MachineRegisterInfo::reg_nodbg_empty(), llvm::LiveIntervals::removeInterval(), selectOrSplit(), TRI, and VRM.

Referenced by llvm::RAGreedy::run(), and llvm::RABasic::runOnMachineFunction().

◆ cleanupFailedVReg()

void RegAllocBase::cleanupFailedVReg ( Register  FailedVReg,
MCRegister  PhysReg,
SmallVectorImpl< Register > &  SplitRegs 
)
protected

Perform cleanups on registers that failed to allocate.

This hacks on the liveness in order to avoid spurious verifier errors in later passes.

Definition at line 165 of file RegAllocBase.cpp.

References llvm::MachineRegisterInfo::isReserved(), llvm::MCRegAliasIterator::isValid(), LIS, MRI, llvm::MachineRegisterInfo::reg_operands(), llvm::LiveIntervals::removeInterval(), llvm::MachineRegisterInfo::replaceRegWith(), and TRI.

Referenced by allocatePhysRegs().

◆ dequeue()

virtual const LiveInterval * llvm::RegAllocBase::dequeue ( )
protectedpure virtual

dequeue - Return the next unassigned register, or NULL.

Implemented in llvm::RABasic, and llvm::RAGreedy.

Referenced by allocatePhysRegs().

◆ enqueue()

void RegAllocBase::enqueue ( const LiveInterval *  LI)
protected

enqueue - Add VirtReg to the priority queue of unassigned registers.

Definition at line 194 of file RegAllocBase.cpp.

References assert(), llvm::dbgs(), enqueueImpl(), llvm::VirtRegMap::hasPhys(), LLVM_DEBUG, llvm::printReg(), llvm::LiveInterval::reg(), shouldAllocateRegister(), TRI, and VRM.

Referenced by allocatePhysRegs().

◆ enqueueImpl()

virtual void llvm::RegAllocBase::enqueueImpl ( const LiveInterval *  LI)
protectedpure virtual

enqueue - Add VirtReg to the priority queue of unassigned registers.

Implemented in llvm::RABasic, and llvm::RAGreedy.

Referenced by enqueue().

◆ getErrorAssignment()

MCPhysReg RegAllocBase::getErrorAssignment ( const TargetRegisterClass &  RC,
const MachineInstr *  CtxMI = nullptr 
)
protected

Query a physical register to use as a filler in contexts where the allocation has failed.

This will raise an error, but not abort the compilation.

Definition at line 211 of file RegAllocBase.cpp.

References assert(), Context, llvm::MachineInstr::emitInlineAsmError(), llvm::ArrayRef< T >::empty(), llvm::ArrayRef< T >::front(), llvm::Function::getContext(), llvm::MachineInstr::getDebugLoc(), llvm::MachineFunction::getFunction(), llvm::VirtRegMap::getMachineFunction(), llvm::RegisterClassInfo::getOrder(), llvm::MachineFunction::getProperties(), llvm::TargetRegisterClass::getRegisters(), llvm::MachineInstr::isInlineAsm(), RegClassInfo, and VRM.

Referenced by allocatePhysRegs().

◆ init()

void RegAllocBase::init ( VirtRegMap &  vrm,
LiveIntervals &  lis,
LiveRegMatrix &  mat 
)
protected

Definition at line 59 of file RegAllocBase.cpp.

References FailedVRegs, llvm::MachineRegisterInfo::freezeReservedRegs(), llvm::VirtRegMap::getMachineFunction(), llvm::VirtRegMap::getRegInfo(), llvm::VirtRegMap::getTargetRegInfo(), LIS, Matrix, MRI, RegClassInfo, llvm::RegisterClassInfo::runOnMachineFunction(), TRI, and VRM.

Referenced by llvm::RAGreedy::run(), and llvm::RABasic::runOnMachineFunction().

◆ postOptimization()

void RegAllocBase::postOptimization ( )
protectedvirtual

Definition at line 156 of file RegAllocBase.cpp.

References DeadRemats, LIS, llvm::Spiller::postOptimization(), llvm::LiveIntervals::RemoveMachineInstrFromMaps(), and spiller().

Referenced by llvm::RAGreedy::run(), and llvm::RABasic::runOnMachineFunction().

◆ selectOrSplit()

virtual MCRegister llvm::RegAllocBase::selectOrSplit ( const LiveInterval &  VirtReg,
SmallVectorImpl< Register > &  splitLVRs 
)
protectedpure virtual

Implemented in llvm::RAGreedy, and llvm::RABasic.

Referenced by allocatePhysRegs().

◆ shouldAllocateRegister()

bool llvm::RegAllocBase::shouldAllocateRegister ( Register  Reg)
inlineprotected

Get whether a given register should be allocated.

Definition at line 95 of file RegAllocBase.h.

References MRI, Reg, and TRI.

Referenced by enqueue().

◆ spiller()

virtual Spiller & llvm::RegAllocBase::spiller ( )
protectedpure virtual

Implemented in llvm::RABasic, and llvm::RAGreedy.

Referenced by postOptimization().

Member Data Documentation

◆ DeadRemats

SmallPtrSet<MachineInstr *, 32> llvm::RegAllocBase::DeadRemats
protected

Inst which is a def of an original reg and whose defs are already all dead after remat is saved in DeadRemats.

The deletion of such inst is postponed till all the allocations are done, so its remat expr is always available for the remat of all the siblings of the original reg.

Definition at line 83 of file RegAllocBase.h.

Referenced by postOptimization(), llvm::RABasic::selectOrSplit(), and llvm::RABasic::spillInterferences().

◆ FailedVRegs

SmallSet<Register, 2> llvm::RegAllocBase::FailedVRegs
protected

Definition at line 85 of file RegAllocBase.h.

Referenced by init().

◆ LIS

LiveIntervals* llvm::RegAllocBase::LIS = nullptr
protected

Definition at line 70 of file RegAllocBase.h.

Referenced by allocatePhysRegs(), cleanupFailedVReg(), init(), postOptimization(), llvm::RAGreedy::RAGreedy(), llvm::RAGreedy::RequiredAnalyses::RequiredAnalyses(), llvm::RAGreedy::run(), llvm::RABasic::runOnMachineFunction(), llvm::RABasic::selectOrSplit(), and llvm::RABasic::spillInterferences().

◆ Matrix

LiveRegMatrix* llvm::RegAllocBase::Matrix = nullptr
protected

Definition at line 71 of file RegAllocBase.h.

Referenced by allocatePhysRegs(), llvm::RegAllocEvictionAdvisor::canReassign(), init(), llvm::RegAllocEvictionAdvisor::isUnusedCalleeSavedReg(), llvm::RAGreedy::RAGreedy(), llvm::RAGreedy::run(), llvm::RABasic::selectOrSplit(), and llvm::RABasic::spillInterferences().

◆ MRI

MachineRegisterInfo* llvm::RegAllocBase::MRI = nullptr
protected

Definition at line 68 of file RegAllocBase.h.

Referenced by allocatePhysRegs(), cleanupFailedVReg(), getInstReadLaneMask(), llvm::RegAllocEvictionAdvisor::getOrderLimit(), hasTiedDef(), init(), readsLaneSubset(), and shouldAllocateRegister().

◆ RegClassInfo

RegisterClassInfo llvm::RegAllocBase::RegClassInfo
protected

Definition at line 72 of file RegAllocBase.h.

Referenced by llvm::RegAllocEvictionAdvisor::canAllocatePhysReg(), llvm::RegAllocEvictionAdvisor::canReassign(), getErrorAssignment(), llvm::RegAllocEvictionAdvisor::getOrderLimit(), init(), llvm::RegAllocEvictionAdvisor::isUnusedCalleeSavedReg(), and llvm::RABasic::selectOrSplit().

◆ TimerGroupDescription

const char RegAllocBase::TimerGroupDescription = "Register Allocation"
staticprotected

Definition at line 141 of file RegAllocBase.h.

◆ TimerGroupName

const char RegAllocBase::TimerGroupName = "regalloc"
staticprotected

Definition at line 140 of file RegAllocBase.h.

◆ TRI

const TargetRegisterInfo* llvm::RegAllocBase::TRI = nullptr
protected

Definition at line 67 of file RegAllocBase.h.

Referenced by allocatePhysRegs(), assignedRegPartiallyOverlaps(), llvm::RegAllocEvictionAdvisor::canAllocatePhysReg(), llvm::RegAllocEvictionAdvisor::canReassign(), cleanupFailedVReg(), enqueue(), getInstReadLaneMask(), getNumAllocatableRegsForConstraints(), llvm::RegAllocEvictionAdvisor::getOrderLimit(), init(), readsLaneSubset(), llvm::RAGreedy::run(), shouldAllocateRegister(), and llvm::RABasic::spillInterferences().

◆ VerifyEnabled

bool RegAllocBase::VerifyEnabled = false
static

VerifyEnabled - True when -verify-regalloc is given.

Definition at line 148 of file RegAllocBase.h.

Referenced by llvm::RAGreedy::run().

◆ VRM

VirtRegMap* llvm::RegAllocBase::VRM = nullptr
protected

Definition at line 69 of file RegAllocBase.h.

Referenced by allocatePhysRegs(), assignedRegPartiallyOverlaps(), llvm::RegAllocEvictionAdvisor::canReassign(), enqueue(), getErrorAssignment(), init(), llvm::RAGreedy::RAGreedy(), llvm::RAGreedy::RequiredAnalyses::RequiredAnalyses(), llvm::RAGreedy::run(), llvm::RABasic::runOnMachineFunction(), llvm::RABasic::selectOrSplit(), and llvm::RABasic::spillInterferences().

The documentation for this class was generated from the following files:
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