Helper class used to represent the cost for mapping an instruction. More...

#include "llvm/CodeGen/GlobalISel/RegBankSelect.h"

Public Member Functions
LLVM_ABI	MappingCost (BlockFrequency LocalFreq)
	Create a MappingCost assuming that most of the instructions will occur in a basic block with `LocalFreq` frequency.
LLVM_ABI bool	addLocalCost (uint64_t Cost)
	Add `Cost` to the local cost.
LLVM_ABI bool	addNonLocalCost (uint64_t Cost)
	Add `Cost` to the non-local cost.
LLVM_ABI void	saturate ()
	Saturate the cost to the maximal representable value.
LLVM_ABI bool	operator< (const MappingCost &Cost) const
	Check if this is less than `Cost`.
LLVM_ABI bool	operator== (const MappingCost &Cost) const
	Check if this is equal to `Cost`.
bool	operator!= (const MappingCost &Cost) const
	Check if this is not equal to `Cost`.
bool	operator> (const MappingCost &Cost) const
	Check if this is greater than `Cost`.
LLVM_ABI void	dump () const
	Print this on dbgs() stream.
LLVM_ABI void	print (raw_ostream &OS) const
	Print this on `OS`;.

Static Public Member Functions
static LLVM_ABI MappingCost	ImpossibleCost ()
	Return an instance of MappingCost that represents an impossible mapping.

Friends
raw_ostream &	operator<< (raw_ostream &OS, const MappingCost &Cost)
	Overload the stream operator for easy debug printing.

Detailed Description

Helper class used to represent the cost for mapping an instruction.

When mapping an instruction, we may introduce some repairing code. In most cases, the repairing code is local to the instruction, thus, we can omit the basic block frequency from the cost. However, some alternatives may produce non-local cost, e.g., when repairing a phi, and thus we then need to scale the local cost to the non-local cost. This class does this for us.

Note: : We could simply always scale the cost. The problem is that there are higher chances that we saturate the cost easier and end up having the same cost for actually different alternatives. Another option would be to use APInt everywhere.

Definition at line 423 of file RegBankSelect.h.

Constructor & Destructor Documentation

◆ MappingCost()

RegBankSelect::MappingCost::MappingCost ( BlockFrequency LocalFreq )

Create a MappingCost assuming that most of the instructions will occur in a basic block with LocalFreq frequency.

Definition at line 994 of file RegBankSelect.cpp.

Member Function Documentation

◆ addLocalCost()

bool RegBankSelect::MappingCost::addLocalCost ( uint64_t Cost )

Add Cost to the local cost.

Returns: true if this cost is saturated, false otherwise.

Definition at line 997 of file RegBankSelect.cpp.

References saturate().

◆ addNonLocalCost()

bool RegBankSelect::MappingCost::addNonLocalCost ( uint64_t Cost )

Add Cost to the non-local cost.

Non-local cost should reflect the frequency of their placement.

Returns: true if this cost is saturated, false otherwise.

Definition at line 1007 of file RegBankSelect.cpp.

References saturate().

◆ dump()

LLVM_DUMP_METHOD void RegBankSelect::MappingCost::dump ( ) const

Print this on dbgs() stream.

Definition at line 1114 of file RegBankSelect.cpp.

References llvm::dbgs(), LLVM_DUMP_METHOD, and llvm::print().

◆ ImpossibleCost()

RegBankSelect::MappingCost RegBankSelect::MappingCost::ImpossibleCost ( )

static

Return an instance of MappingCost that represents an impossible mapping.

Definition at line 1027 of file RegBankSelect.cpp.

References UINT64_MAX.

Referenced by llvm::RegBankSelect::assignInstr(), llvm::RegBankSelect::computeMapping(), llvm::RegBankSelect::findBestMapping(), operator<(), print(), and saturate().

◆ operator!=()

bool llvm::RegBankSelect::MappingCost::operator!= ( const MappingCost & Cost ) const

inline

Check if this is not equal to Cost.

Definition at line 467 of file RegBankSelect.h.

◆ operator<()

bool RegBankSelect::MappingCost::operator< ( const MappingCost & Cost ) const

Check if this is less than Cost.

Definition at line 1031 of file RegBankSelect.cpp.

References ImpossibleCost(), and LLVM_LIKELY.

◆ operator==()

bool RegBankSelect::MappingCost::operator== ( const MappingCost & Cost ) const

Check if this is equal to Cost.

Definition at line 1108 of file RegBankSelect.cpp.

◆ operator>()

bool llvm::RegBankSelect::MappingCost::operator> ( const MappingCost & Cost ) const

inline

Check if this is greater than Cost.

Definition at line 469 of file RegBankSelect.h.

◆ print()

void RegBankSelect::MappingCost::print ( raw_ostream & OS ) const

Print this on OS;.

Definition at line 1120 of file RegBankSelect.cpp.

References ImpossibleCost().

◆ saturate()

void RegBankSelect::MappingCost::saturate ( )

Saturate the cost to the maximal representable value.

Definition at line 1022 of file RegBankSelect.cpp.

References ImpossibleCost().

Referenced by addLocalCost(), and addNonLocalCost().

◆ operator<<

raw_ostream & operator<<	(	raw_ostream &	OS,
		const MappingCost &	Cost )

friend

Overload the stream operator for easy debug printing.

Definition at line 480 of file RegBankSelect.h.

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

include/llvm/CodeGen/GlobalISel/RegBankSelect.h
lib/CodeGen/GlobalISel/RegBankSelect.cpp

Public Member Functions

Static Public Member Functions

Friends