LLVM  4.0.0
Public Types | Public Member Functions | List of all members
llvm::LivePhysRegs Class Reference

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

#include <LivePhysRegs.h>

Public Types

typedef SparseSet< unsigned >
::const_iterator 
const_iterator
 

Public Member Functions

 LivePhysRegs ()=default
 Constructs a new empty LivePhysRegs set. More...
 
 LivePhysRegs (const TargetRegisterInfo *TRI)
 Constructs and initialize an empty LivePhysRegs set. More...
 
void init (const TargetRegisterInfo &TRI)
 Clear and initialize the LivePhysRegs set. More...
 
void clear ()
 Clears the LivePhysRegs set. More...
 
bool empty () const
 Returns true if the set is empty. More...
 
void addReg (unsigned Reg)
 Adds a physical register and all its sub-registers to the set. More...
 
void removeReg (unsigned Reg)
 Removes a physical register, all its sub-registers, and all its super-registers from the set. More...
 
void removeRegsInMask (const MachineOperand &MO, SmallVectorImpl< std::pair< unsigned, const MachineOperand * >> *Clobbers)
 Removes physical registers clobbered by the regmask operand MO. More...
 
bool contains (unsigned Reg) const
 Returns true if register Reg is contained in the set. More...
 
bool available (const MachineRegisterInfo &MRI, unsigned Reg) const
 Returns true if register Reg and no aliasing register is in the set. More...
 
void stepBackward (const MachineInstr &MI)
 Simulates liveness when stepping backwards over an instruction(bundle): Remove Defs, add uses. More...
 
void stepForward (const MachineInstr &MI, SmallVectorImpl< std::pair< unsigned, const MachineOperand * >> &Clobbers)
 Simulates liveness when stepping forward over an instruction(bundle): Remove killed-uses, add defs. More...
 
void addLiveIns (const MachineBasicBlock &MBB)
 Adds all live-in registers of basic block MBB. More...
 
void addLiveOuts (const MachineBasicBlock &MBB)
 Adds all live-out registers of basic block MBB. More...
 
void addLiveOutsNoPristines (const MachineBasicBlock &MBB)
 Like addLiveOuts() but does not add pristine registers/callee saved registers. More...
 
const_iterator begin () const
 
const_iterator end () const
 
void print (raw_ostream &OS) const
 Prints the currently live registers to OS. More...
 
void dump () const
 Dumps the currently live registers to the debug output. More...
 

Detailed Description

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

Definition at line 45 of file LivePhysRegs.h.

Member Typedef Documentation

Definition at line 137 of file LivePhysRegs.h.

Constructor & Destructor Documentation

llvm::LivePhysRegs::LivePhysRegs ( )
default

Constructs a new empty LivePhysRegs set.

llvm::LivePhysRegs::LivePhysRegs ( const TargetRegisterInfo TRI)
inline

Constructs and initialize an empty LivePhysRegs set.

Definition at line 57 of file LivePhysRegs.h.

References assert(), llvm::MCRegisterInfo::getNumRegs(), and llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::setUniverse().

Member Function Documentation

void LivePhysRegs::addLiveIns ( const MachineBasicBlock MBB)

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 193 of file LivePhysRegs.cpp.

References addPristines(), llvm::MachineFunction::getFrameInfo(), llvm::MachineBasicBlock::getParent(), and llvm::MachineFrameInfo::isCalleeSavedInfoValid().

Referenced by findScratchNonCalleeSaveRegister().

void LivePhysRegs::addLiveOuts ( const MachineBasicBlock MBB)

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.

Definition at line 176 of file LivePhysRegs.cpp.

References addLiveOutsNoPristines(), addPristines(), addReg(), llvm::TargetRegisterInfo::getCalleeSavedRegs(), llvm::MachineFunction::getFrameInfo(), llvm::MachineBasicBlock::getParent(), I, llvm::MachineFrameInfo::isCalleeSavedInfoValid(), and llvm::MachineBasicBlock::isReturnBlock().

Referenced by llvm::X86InstrInfo::copyPhysReg(), and getLiveRegsAt().

void LivePhysRegs::addLiveOutsNoPristines ( const MachineBasicBlock MBB)

Like addLiveOuts() but does not add pristine registers/callee saved registers.

Definition at line 170 of file LivePhysRegs.cpp.

References llvm::MachineBasicBlock::successors().

Referenced by addLiveOuts(), and llvm::computeLiveIns().

void llvm::LivePhysRegs::addReg ( unsigned  Reg)
inline
bool LivePhysRegs::available ( const MachineRegisterInfo MRI,
unsigned  Reg 
) const
const_iterator llvm::LivePhysRegs::begin ( ) const
inline
void llvm::LivePhysRegs::clear ( )
inline

Clears the LivePhysRegs set.

Definition at line 70 of file LivePhysRegs.h.

References llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::clear().

bool llvm::LivePhysRegs::contains ( unsigned  Reg) const
inline

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 102 of file LivePhysRegs.h.

References llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::count().

Referenced by llvm::X86InstrInfo::copyPhysReg(), and RemoveKills().

LLVM_DUMP_METHOD void LivePhysRegs::dump ( ) const

Dumps the currently live registers to the debug output.

Definition at line 124 of file LivePhysRegs.cpp.

References llvm::dbgs().

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

Returns true if the set is empty.

Definition at line 73 of file LivePhysRegs.h.

References llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::empty().

Referenced by print().

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

Definition at line 139 of file LivePhysRegs.h.

References llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::end().

Referenced by addPostLoopLiveIns(), and print().

void llvm::LivePhysRegs::init ( const TargetRegisterInfo TRI)
inline
void LivePhysRegs::print ( raw_ostream OS) const

Prints the currently live registers to OS.

Prin the currently live registers to OS.

Definition at line 106 of file LivePhysRegs.cpp.

References begin(), E, empty(), end(), I, and llvm::PrintReg().

Referenced by llvm::operator<<().

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

Removes a physical register, all its sub-registers, and all its super-registers from the set.

Definition at line 86 of file LivePhysRegs.h.

References assert(), llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::erase(), and llvm::MCRegAliasIterator::isValid().

Referenced by addPristines(), stepBackward(), and stepForward().

void LivePhysRegs::removeRegsInMask ( const MachineOperand MO,
SmallVectorImpl< std::pair< unsigned, const MachineOperand * >> *  Clobbers 
)

Removes physical registers clobbered by the regmask operand MO.

Remove all registers from the set that get clobbered by the register mask.

The clobbers set will be the list of live registers clobbered by the regmask.

Definition at line 30 of file LivePhysRegs.cpp.

References llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::begin(), llvm::MachineOperand::clobbersPhysReg(), llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::end(), and llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::erase().

Referenced by stepBackward(), and stepForward().

void LivePhysRegs::stepBackward ( const MachineInstr MI)

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

This is the recommended way of calculating liveness.

Definition at line 45 of file LivePhysRegs.cpp.

References addReg(), llvm::TargetRegisterInfo::isPhysicalRegister(), llvm::MachineOperandIteratorBase::isValid(), removeReg(), and removeRegsInMask().

Referenced by llvm::computeLiveIns(), llvm::X86InstrInfo::copyPhysReg(), and getLiveRegsAt().

void LivePhysRegs::stepForward ( const MachineInstr MI,
SmallVectorImpl< std::pair< unsigned, const MachineOperand * >> &  Clobbers 
)

Simulates liveness when stepping forward over an instruction(bundle): 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 74 of file LivePhysRegs.cpp.

References addReg(), assert(), llvm::TargetRegisterInfo::isPhysicalRegister(), llvm::MachineOperandIteratorBase::isValid(), removeReg(), and removeRegsInMask().


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