A Chain is a sequence of instructions that are linked together by an accumulation operand. More...

Public Member Functions
	Chain (MachineInstr *MI, unsigned Idx, Color C)
void	add (MachineInstr *MI, unsigned Idx, Color C)
	Add a new instruction into the chain.
bool	contains (MachineInstr &MI)
	Return true if MI is a member of the chain.
unsigned	size () const
	Return the number of instructions in the chain.
void	setKill (MachineInstr *MI, unsigned Idx, bool Immutable)
	Inform the chain that its last active register (the dest register of LastInst) is killed by MI with no intervening uses or defs.
MachineInstr *	getStart () const
	Return the first instruction in the chain.
MachineInstr *	getLast () const
	Return the last instruction in the chain.
MachineInstr *	getKill () const
	Return the "kill" instruction (as set with setKill()) or NULL.
MachineBasicBlock::iterator	end () const
	Return an instruction that can be used as an iterator for the end of the chain.
MachineBasicBlock::iterator	begin () const
bool	isKillImmutable () const
	Can the Kill instruction (assuming one exists) be modified?
Color	getPreferredColor ()
	Return the preferred color of this chain.
bool	rangeOverlapsWith (const Chain &Other) const
	Return true if this chain (StartInst..KillInst) overlaps with Other.
bool	startsBefore (const Chain *Other) const
	Return true if this chain starts before Other.
bool	requiresFixup () const
	Return true if the group will require a fixup MOV at the end.
std::string	str () const
	Return a simple string representation of the chain.

Public Attributes
MachineInstr *	StartInst
	The important (marker) instructions.
MachineInstr *	LastInst
MachineInstr *	KillInst
unsigned	StartInstIdx
	The index, from the start of the basic block, that each marker appears.
unsigned	LastInstIdx
unsigned	KillInstIdx
std::set< MachineInstr * >	Insts
	All instructions in the chain.
bool	KillIsImmutable
	True if KillInst cannot be modified.
Color	LastColor
	The "color" of LastInst.

Detailed Description

A Chain is a sequence of instructions that are linked together by an accumulation operand.

For example:

fmul def d0, ? fmla def d1, ?, ?, killed d0 fmla def d2, ?, ?, killed d1

There may be other instructions interleaved in the sequence that do not belong to the chain. These other instructions must not use the "chain" register at any point.

We currently only support chains where the "chain" operand is killed at each link in the chain for simplicity. A chain has three important instructions - Start, Last and Kill.

The start instruction is the first instruction in the chain.
Last is the final instruction in the chain.
Kill may or may not be defined. If defined, Kill is the instruction where the outgoing value of the Last instruction is killed. This information is important as if we know the outgoing value is killed with no intervening uses, we can safely change its register.

Without a kill instruction, we must assume the outgoing value escapes beyond our model and either must not change its register or must create a fixup FMOV to keep the old register value consistent.

Definition at line 181 of file AArch64A57FPLoadBalancing.cpp.

Constructor & Destructor Documentation

◆ Chain()

false::Chain::Chain	(	MachineInstr *	MI,
		unsigned	Idx,
		Color	C )

inline

Definition at line 199 of file AArch64A57FPLoadBalancing.cpp.

References llvm::CallingConv::C, Insts, KillInst, KillInstIdx, LastColor, LastInst, LastInstIdx, MI, StartInst, and StartInstIdx.

Referenced by rangeOverlapsWith(), and startsBefore().

Member Function Documentation

◆ add()

void false::Chain::add	(	MachineInstr *	MI,
		unsigned	Idx,
		Color	C )

inline

Add a new instruction into the chain.

The instruction's dest operand has the given color.

Definition at line 208 of file AArch64A57FPLoadBalancing.cpp.

References assert(), llvm::CallingConv::C, Insts, KillInstIdx, LastColor, LastInst, LastInstIdx, and MI.

◆ begin()

MachineBasicBlock::iterator false::Chain::begin ( ) const

inline

Definition at line 249 of file AArch64A57FPLoadBalancing.cpp.

References getStart().

◆ contains()

bool false::Chain::contains ( MachineInstr & MI )

inline

Return true if MI is a member of the chain.

Definition at line 220 of file AArch64A57FPLoadBalancing.cpp.

References Insts, and MI.

◆ end()

MachineBasicBlock::iterator false::Chain::end ( ) const

inline

Return an instruction that can be used as an iterator for the end of the chain.

This is the maximum of KillInst (if set) and LastInst.

Definition at line 246 of file AArch64A57FPLoadBalancing.cpp.

References KillInst, and LastInst.

◆ getKill()

MachineInstr * false::Chain::getKill ( ) const

inline

Return the "kill" instruction (as set with setKill()) or NULL.

Definition at line 243 of file AArch64A57FPLoadBalancing.cpp.

References KillInst.

Referenced by requiresFixup().

◆ getLast()

MachineInstr * false::Chain::getLast ( ) const

inline

Return the last instruction in the chain.

Definition at line 241 of file AArch64A57FPLoadBalancing.cpp.

References LastInst.

◆ getPreferredColor()

Color false::Chain::getPreferredColor ( )

inline

Return the preferred color of this chain.

Definition at line 255 of file AArch64A57FPLoadBalancing.cpp.

References LastColor, and OverrideBalance.

◆ getStart()

MachineInstr * false::Chain::getStart ( ) const

inline

Return the first instruction in the chain.

Definition at line 239 of file AArch64A57FPLoadBalancing.cpp.

References StartInst.

Referenced by begin().

◆ isKillImmutable()

bool false::Chain::isKillImmutable ( ) const

inline

Can the Kill instruction (assuming one exists) be modified?

Definition at line 252 of file AArch64A57FPLoadBalancing.cpp.

References KillIsImmutable.

Referenced by requiresFixup().

◆ rangeOverlapsWith()

bool false::Chain::rangeOverlapsWith ( const Chain & Other ) const

inline

Return true if this chain (StartInst..KillInst) overlaps with Other.

Definition at line 262 of file AArch64A57FPLoadBalancing.cpp.

References Chain(), KillInst, KillInstIdx, LastInstIdx, llvm::Other, and StartInstIdx.

◆ requiresFixup()

bool false::Chain::requiresFixup ( ) const

inline

Return true if the group will require a fixup MOV at the end.

Definition at line 276 of file AArch64A57FPLoadBalancing.cpp.

References getKill(), and isKillImmutable().

◆ setKill()

void false::Chain::setKill	(	MachineInstr *	MI,
		unsigned	Idx,
		bool	Immutable )

inline

Inform the chain that its last active register (the dest register of LastInst) is killed by MI with no intervening uses or defs.

Definition at line 229 of file AArch64A57FPLoadBalancing.cpp.

References assert(), KillInst, KillInstIdx, KillIsImmutable, LastInstIdx, and MI.

◆ size()

unsigned false::Chain::size ( ) const

inline

Return the number of instructions in the chain.

Definition at line 223 of file AArch64A57FPLoadBalancing.cpp.

References Insts.

◆ startsBefore()

bool false::Chain::startsBefore ( const Chain * Other ) const

inline

Return true if this chain starts before Other.

Definition at line 271 of file AArch64A57FPLoadBalancing.cpp.

References Chain(), llvm::Other, and StartInstIdx.

◆ str()

std::string false::Chain::str ( ) const

inline

Return a simple string representation of the chain.

Definition at line 281 of file AArch64A57FPLoadBalancing.cpp.

References KillInst, LastInst, StartInst, and llvm::raw_string_ostream::str().

Member Data Documentation

◆ Insts

std::set<MachineInstr*> false::Chain::Insts

All instructions in the chain.

Definition at line 189 of file AArch64A57FPLoadBalancing.cpp.

Referenced by add(), Chain(), contains(), and size().

◆ KillInst

MachineInstr * false::Chain::KillInst

Definition at line 184 of file AArch64A57FPLoadBalancing.cpp.

Referenced by Chain(), end(), getKill(), rangeOverlapsWith(), setKill(), and str().

◆ KillInstIdx

unsigned false::Chain::KillInstIdx

Definition at line 187 of file AArch64A57FPLoadBalancing.cpp.

Referenced by add(), Chain(), rangeOverlapsWith(), and setKill().

◆ KillIsImmutable

bool false::Chain::KillIsImmutable

True if KillInst cannot be modified.

If this is true, we cannot change LastInst's outgoing register. This will be true for tied values and regmasks.

Definition at line 193 of file AArch64A57FPLoadBalancing.cpp.

Referenced by isKillImmutable(), and setKill().

◆ LastColor

Color false::Chain::LastColor

The "color" of LastInst.

This will be the preferred chain color, as changing intermediate nodes is easy but changing the last instruction can be more tricky.

Definition at line 197 of file AArch64A57FPLoadBalancing.cpp.

Referenced by add(), Chain(), and getPreferredColor().

◆ LastInst

MachineInstr * false::Chain::LastInst

Definition at line 184 of file AArch64A57FPLoadBalancing.cpp.

Referenced by add(), Chain(), end(), getLast(), and str().

◆ LastInstIdx

unsigned false::Chain::LastInstIdx

Definition at line 187 of file AArch64A57FPLoadBalancing.cpp.

Referenced by add(), Chain(), rangeOverlapsWith(), and setKill().

◆ StartInst

MachineInstr* false::Chain::StartInst

The important (marker) instructions.

Definition at line 184 of file AArch64A57FPLoadBalancing.cpp.

Referenced by Chain(), getStart(), and str().

◆ StartInstIdx

unsigned false::Chain::StartInstIdx

The index, from the start of the basic block, that each marker appears.

These are stored so we can do quick interval tests.

Definition at line 187 of file AArch64A57FPLoadBalancing.cpp.

Referenced by Chain(), rangeOverlapsWith(), and startsBefore().

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

lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp

Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Chain()

Member Function Documentation

◆ add()

◆ begin()

◆ contains()

◆ end()

◆ getKill()

◆ getLast()

◆ getPreferredColor()

◆ getStart()

◆ isKillImmutable()

◆ rangeOverlapsWith()

◆ requiresFixup()

◆ setKill()

◆ size()

◆ startsBefore()

◆ str()

Member Data Documentation

◆ Insts

◆ KillInst

◆ KillInstIdx

◆ KillIsImmutable

◆ LastColor

◆ LastInst

◆ LastInstIdx

◆ StartInst

◆ StartInstIdx