llvm::RegisterClassInfo Class Reference

#include "llvm/CodeGen/RegisterClassInfo.h"

Public Member Functions
LLVM_ABI	RegisterClassInfo ()
LLVM_ABI void	runOnMachineFunction (const MachineFunction &MF, bool Rev=false)
	runOnFunction - Prepare to answer questions about MF.
unsigned	getNumAllocatableRegs (const TargetRegisterClass *RC) const
	getNumAllocatableRegs - Returns the number of actually allocatable registers in RC in the current function.
ArrayRef< MCPhysReg >	getOrder (const TargetRegisterClass *RC) const
	getOrder - Returns the preferred allocation order for RC.
bool	isProperSubClass (const TargetRegisterClass *RC) const
	isProperSubClass - Returns true if RC has a legal super-class with more allocatable registers.
MCRegister	getLastCalleeSavedAlias (MCRegister PhysReg) const
	getLastCalleeSavedAlias - Returns the last callee saved register that overlaps PhysReg, or NoRegister if PhysReg doesn't overlap a CalleeSavedAliases.
uint8_t	getMinCost (const TargetRegisterClass *RC) const
	Get the minimum register cost in RC's allocation order.
unsigned	getLastCostChange (const TargetRegisterClass *RC) const
	Get the position of the last cost change in getOrder(RC).
unsigned	getRegPressureSetLimit (unsigned Idx) const
	Get the register unit limit for the given pressure set index.

Protected Member Functions
LLVM_ABI unsigned	computePSetLimit (unsigned Idx) const
	This is not accurate because two overlapping register sets may have some nonoverlapping reserved registers.

Detailed Description

Definition at line 30 of file RegisterClassInfo.h.

Constructor & Destructor Documentation

RegisterClassInfo()

RegisterClassInfo::RegisterClassInfo ( )

default

References LLVM_ABI.

Member Function Documentation

computePSetLimit()

unsigned RegisterClassInfo::computePSetLimit ( unsigned Idx ) const

protected

This is not accurate because two overlapping register sets may have some nonoverlapping reserved registers.

However, computing the allocation order for all register classes would be too expensive.

Definition at line 210 of file RegisterClassInfo.cpp.

References assert(), llvm::CallingConv::C, getNumAllocatableRegs(), and llvm::TargetRegisterClass::getNumRegs().

Referenced by getRegPressureSetLimit().

getLastCalleeSavedAlias()

MCRegister llvm::RegisterClassInfo::getLastCalleeSavedAlias ( MCRegister PhysReg ) const

inline

getLastCalleeSavedAlias - Returns the last callee saved register that overlaps PhysReg, or NoRegister if PhysReg doesn't overlap a CalleeSavedAliases.

Definition at line 123 of file RegisterClassInfo.h.

getLastCostChange()

unsigned llvm::RegisterClassInfo::getLastCostChange ( const TargetRegisterClass * RC ) const

inline

Get the position of the last cost change in getOrder(RC).

All registers in getOrder(RC).slice(getLastCostChange(RC)) will have the same cost according to RegCosts[Reg].

Definition at line 144 of file RegisterClassInfo.h.

getMinCost()

uint8_t llvm::RegisterClassInfo::getMinCost ( const TargetRegisterClass * RC ) const

inline

Get the minimum register cost in RC's allocation order.

This is the smallest value in RegCosts[Reg] for all the registers in getOrder(RC).

Definition at line 136 of file RegisterClassInfo.h.

getNumAllocatableRegs()

unsigned llvm::RegisterClassInfo::getNumAllocatableRegs ( const TargetRegisterClass * RC ) const

inline

getNumAllocatableRegs - Returns the number of actually allocatable registers in RC in the current function.

Definition at line 99 of file RegisterClassInfo.h.

Referenced by computePSetLimit(), and getNumAllocatableRegsForConstraints().

getOrder()

ArrayRef< MCPhysReg > llvm::RegisterClassInfo::getOrder ( const TargetRegisterClass * RC ) const

inline

getOrder - Returns the preferred allocation order for RC.

The order contains no reserved registers, and registers that alias callee saved registers come last.

Definition at line 106 of file RegisterClassInfo.h.

Referenced by llvm::AllocationOrder::create().

getRegPressureSetLimit()

unsigned llvm::RegisterClassInfo::getRegPressureSetLimit ( unsigned Idx ) const

inline

Get the register unit limit for the given pressure set index.

RegisterClassInfo adjusts this limit for reserved registers.

Definition at line 151 of file RegisterClassInfo.h.

References computePSetLimit().

Referenced by computeExcessPressureDelta(), and llvm::PPCInstrInfo::shouldReduceRegisterPressure().

isProperSubClass()

bool llvm::RegisterClassInfo::isProperSubClass ( const TargetRegisterClass * RC ) const

inline

isProperSubClass - Returns true if RC has a legal super-class with more allocatable registers.

Register classes like GR32_NOSP are not proper sub-classes because esp is not allocatable. Similarly, tGPR is not a proper sub-class in Thumb mode because the GPR super-class is not legal.

Definition at line 116 of file RegisterClassInfo.h.

runOnMachineFunction()

void RegisterClassInfo::runOnMachineFunction	(	const MachineFunction &	MF,
		bool	Rev = false )

runOnFunction - Prepare to answer questions about MF.

Rev indicates to use reversed raw order when compute register order. This must be called before any other methods are used.

Definition at line 42 of file RegisterClassInfo.cpp.

References llvm::MachineFunction::getSubtarget(), I, llvm::MCRegAliasIterator::isValid(), and MRI.

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

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

• include/llvm/CodeGen/RegisterClassInfo.h
• lib/CodeGen/RegisterClassInfo.cpp