LLVM: llvm::LivePhysRegs Class Reference (original) (raw)

A set of physical registers with utility functions to track liveness when walking backward/forward through a basic block. More...

#include "[llvm/CodeGen/LivePhysRegs.h](LivePhysRegs%5F8h%5Fsource.html)"

Public Member Functions
LivePhysRegs ()=default
Constructs an unitialized set. init() needs to be called to initialize it.
LivePhysRegs (const TargetRegisterInfo &TRI)
Constructs and initializes an empty set.
LivePhysRegs (const LivePhysRegs &)=delete
LivePhysRegs & operator= (const LivePhysRegs &)=delete
void init (const TargetRegisterInfo &TRI)
(re-)initializes and clears the set.
void clear ()
Clears the set.
bool empty () const
Returns true if the set is empty.
void addReg (MCRegister Reg)
Adds a physical register and all its sub-registers to the set.
void removeReg (MCRegister Reg)
Removes a physical register, all its sub-registers, and all its super-registers from the set.
void removeRegsInMask (const MachineOperand &MO, SmallVectorImpl< std::pair< MCPhysReg, const MachineOperand * > > *Clobbers=nullptr)
Removes physical registers clobbered by the regmask operand MO.
bool contains (MCRegister Reg) const
Returns true if register Reg is contained in the set.
bool available (const MachineRegisterInfo &MRI, MCRegister Reg) const
Returns true if register Reg and no aliasing register is in the set.
void removeDefs (const MachineInstr &MI)
Remove defined registers and regmask kills from the set.
void addUses (const MachineInstr &MI)
Add uses to the set.
void stepBackward (const MachineInstr &MI)
Simulates liveness when stepping backwards over an instruction(bundle).
void stepForward (const MachineInstr &MI, SmallVectorImpl< std::pair< MCPhysReg, const MachineOperand * > > &Clobbers)
Simulates liveness when stepping forward over an instruction(bundle).
void addLiveIns (const MachineBasicBlock &MBB)
Adds all live-in registers of basic block MBB.
void addLiveInsNoPristines (const MachineBasicBlock &MBB)
Adds all live-in registers of basic block MBB but skips pristine registers.
void addLiveOuts (const MachineBasicBlock &MBB)
Adds all live-out registers of basic block MBB.
void addLiveOutsNoPristines (const MachineBasicBlock &MBB)
Adds all live-out registers of basic block MBB but skips pristine registers.
const_iterator begin () const
const_iterator end () const
void print (raw_ostream &OS) const
Prints the currently live registers to OS.
void dump () const
Dumps the currently live registers to the debug output.

A set of physical registers with utility functions to track liveness when walking backward/forward through a basic block.

Definition at line 52 of file LivePhysRegs.h.

◆ const_iterator

llvm::LivePhysRegs::LivePhysRegs ( ) default

Constructs an unitialized set. init() needs to be called to initialize it.

Referenced by LivePhysRegs(), and operator=().

◆ LivePhysRegs() [2/3]

Constructs and initializes an empty set.

Definition at line 62 of file LivePhysRegs.h.

◆ LivePhysRegs() [3/3]

References LivePhysRegs().

◆ addLiveIns()

Adds all live-in registers of basic block MBB.

Live in registers are the registers in the blocks live-in list and the pristine registers.

Definition at line 247 of file LivePhysRegs.cpp.

References MBB.

Referenced by getLiveInRegsAt().

◆ addLiveInsNoPristines()

Adds all live-in registers of basic block MBB but skips pristine registers.

Definition at line 253 of file LivePhysRegs.cpp.

References MBB.

◆ addLiveOuts()

Adds all live-out registers of basic block MBB.

Live out registers are the union of the live-in registers of the successor blocks and pristine registers. Live out registers of the end block are the callee saved registers. If a register is not added by this method, it is guaranteed to not be live out from MBB, although a sub-register may be. This is true both before and after regalloc.

Definition at line 241 of file LivePhysRegs.cpp.

References addLiveOutsNoPristines(), and MBB.

Referenced by getLiveOutRegsAt(), and RemoveLoadsIntoFakeUses::run().

◆ addLiveOutsNoPristines()

◆ addReg()

void llvm::LivePhysRegs::addReg ( MCRegister Reg) inline

◆ addUses()

◆ available()

◆ begin()

const_iterator llvm::LivePhysRegs::begin ( ) const inline

◆ clear()

void llvm::LivePhysRegs::clear ( ) inline

◆ contains()

Returns true if register Reg is contained in the set.

This also works if only the super register of Reg has been defined, because addReg() always adds all sub-registers to the set as well. Note: Returns false if just some sub registers are live, use available() when searching a free register.

Definition at line 109 of file LivePhysRegs.h.

References Reg.

Referenced by llvm::HexagonInstrInfo::copyPhysReg().

◆ dump()

◆ empty()

bool llvm::LivePhysRegs::empty ( ) const inline

◆ end()

const_iterator llvm::LivePhysRegs::end ( ) const inline

◆ init()

◆ operator=()

References LivePhysRegs().

◆ print()

◆ removeDefs()

◆ removeReg()

void llvm::LivePhysRegs::removeReg ( MCRegister Reg) inline

◆ removeRegsInMask()

◆ stepBackward()

Simulates liveness when stepping backwards over an instruction(bundle).

Simulates liveness when stepping backwards over an instruction(bundle): Remove Defs, add uses.

Remove Defs, add uses. This is the recommended way of calculating liveness.

This is the recommended way of calculating liveness.

Definition at line 68 of file LivePhysRegs.cpp.

References addUses(), MI, and removeDefs().

Referenced by getLiveOutRegsAt(), and RemoveLoadsIntoFakeUses::run().

◆ stepForward()

Simulates liveness when stepping forward over an instruction(bundle).

Simulates liveness when stepping forward over an instruction(bundle): Remove killed-uses, add defs.

Remove killed-uses, add defs. This is the not recommended way, because it depends on accurate kill flags. If possible use stepBackward() instead of this function. The clobbers set will be the list of registers either defined or clobbered by a regmask. The operand will identify whether this is a regmask or register operand.

This is the not recommended way, because it depends on accurate kill flags. If possible use stepBackward() instead of this function.

Definition at line 80 of file LivePhysRegs.cpp.

References addReg(), assert(), llvm::MachineOperand::clobbersPhysReg(), MI, removeReg(), and removeRegsInMask().

Referenced by getLiveInRegsAt(), and UpdatePredRedefs().

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