class VirtRegAuxInfo

Declaration

class VirtRegAuxInfo { /* full declaration omitted */ };

Description

Calculate auxiliary information for a virtual register such as its spill weight and allocation hint.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:45

Member Variables

private llvm::MachineFunction& MF

private llvm::LiveIntervals& LIS

private const llvm::VirtRegMap& VRM

private const llvm::MachineLoopInfo& Loops

private const llvm::MachineBlockFrequencyInfo& MBFI

Method Overview

• public VirtRegAuxInfo(llvm::MachineFunction & MF, llvm::LiveIntervals & LIS, const llvm::VirtRegMap & VRM, const llvm::MachineLoopInfo & Loops, const llvm::MachineBlockFrequencyInfo & MBFI)
• public void calculateSpillWeightAndHint(llvm::LiveInterval & LI)
• public void calculateSpillWeightsAndHints()
• public static llvm::Register copyHint(const llvm::MachineInstr * MI, unsigned int Reg, const llvm::TargetRegisterInfo & TRI, const llvm::MachineRegisterInfo & MRI)
• private bool isLiveAtStatepointVarArg(llvm::LiveInterval & LI)
• public static bool isRematerializable(const llvm::LiveInterval & LI, const llvm::LiveIntervals & LIS, const llvm::VirtRegMap & VRM, const llvm::TargetInstrInfo & TII)
• protected virtual float normalize(float UseDefFreq, unsigned int Size, unsigned int NumInstr)
• protected float weightCalcHelper(llvm::LiveInterval & LI, llvm::SlotIndex * Start = nullptr, llvm::SlotIndex * End = nullptr)
• public virtual ~VirtRegAuxInfo()

Methods

¶VirtRegAuxInfo(
    llvm::MachineFunction& MF,
    llvm::LiveIntervals& LIS,
    const llvm::VirtRegMap& VRM,
    const llvm::MachineLoopInfo& Loops,
    const llvm::MachineBlockFrequencyInfo& MBFI)

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:57

Parameters

llvm::MachineFunction& MF

llvm::LiveIntervals& LIS

const llvm::VirtRegMap& VRM

const llvm::MachineLoopInfo& Loops

const llvm::MachineBlockFrequencyInfo& MBFI

¶void calculateSpillWeightAndHint(
    llvm::LiveInterval& LI)

Description

(re)compute li's spill weight and allocation hint.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:65

Parameters

llvm::LiveInterval& LI

¶void calculateSpillWeightsAndHints()

Description

Compute spill weights and allocation hints for all virtual register live intervals.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:69

¶static llvm::Register copyHint(
    const llvm::MachineInstr* MI,
    unsigned int Reg,
    const llvm::TargetRegisterInfo& TRI,
    const llvm::MachineRegisterInfo& MRI)

Description

Return the preferred allocation register for reg, given a COPY instruction.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:73

Parameters

const llvm::MachineInstr* MI

unsigned int Reg

const llvm::TargetRegisterInfo& TRI

const llvm::MachineRegisterInfo& MRI

¶bool isLiveAtStatepointVarArg(
    llvm::LiveInterval& LI)

Description

Returns true if Reg of live interval LI is used in instruction with many operands like STATEPOINT.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:54

Parameters

llvm::LiveInterval& LI

¶static bool isRematerializable(
    const llvm::LiveInterval& LI,
    const llvm::LiveIntervals& LIS,
    const llvm::VirtRegMap& VRM,
    const llvm::TargetInstrInfo& TII)

Description

Determine if all values in LI are rematerializable.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:78

Parameters

const llvm::LiveInterval& LI

const llvm::LiveIntervals& LIS

const llvm::VirtRegMap& VRM

const llvm::TargetInstrInfo& TII

¶virtual float normalize(float UseDefFreq,
                        unsigned int Size,
                        unsigned int NumInstr)

Description

Weight normalization function.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:100

Parameters

float UseDefFreq

unsigned int Size

unsigned int NumInstr

¶float weightCalcHelper(
    llvm::LiveInterval& LI,
    llvm::SlotIndex* Start = nullptr,
    llvm::SlotIndex* End = nullptr)

Description

Helper function for weight calculations. (Re)compute LI's spill weight and allocation hint, or, for non null start and end - compute future expected spill weight of a split artifact of LI that will span between start and end slot indexes.

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:96

Parameters

llvm::LiveInterval& LI

The live interval for which to compute the weight.

llvm::SlotIndex* Start = nullptr

The expected beginning of the split artifact. Instructions before start will not affect the weight. Relevant for weight calculation of future split artifact.

llvm::SlotIndex* End = nullptr

The expected end of the split artifact. Instructions after end will not affect the weight. Relevant for weight calculation of future split artifact.

Returns

The spill weight. Returns negative weight for unspillable LI.

¶virtual ~VirtRegAuxInfo()

Declared at: llvm/include/llvm/CodeGen/CalcSpillWeights.h:62