LLVM  13.0.0git
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llvm::LiveRangeCalc Class Reference

#include "llvm/CodeGen/LiveRangeCalc.h"

Inheritance diagram for llvm::LiveRangeCalc:
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Public Member Functions

 LiveRangeCalc ()=default
 
void reset (const MachineFunction *mf, SlotIndexes *SI, MachineDominatorTree *MDT, VNInfo::Allocator *VNIA)
 reset - Prepare caches for a new set of non-overlapping live ranges. More...
 
void extend (LiveRange &LR, SlotIndex Use, unsigned PhysReg, ArrayRef< SlotIndex > Undefs)
 Extend the live range of LR to reach Use. More...
 
void setLiveOutValue (MachineBasicBlock *MBB, VNInfo *VNI)
 setLiveOutValue - Indicate that VNI is live out from MBB. More...
 
void addLiveInBlock (LiveRange &LR, MachineDomTreeNode *DomNode, SlotIndex Kill=SlotIndex())
 addLiveInBlock - Add a block with an unknown live-in value. More...
 
void calculateValues ()
 calculateValues - Calculate the value that will be live-in to each block added with addLiveInBlock. More...
 

Static Public Member Functions

static LLVM_ATTRIBUTE_UNUSED bool isJointlyDominated (const MachineBasicBlock *MBB, ArrayRef< SlotIndex > Defs, const SlotIndexes &Indexes)
 A diagnostic function to check if the end of the block MBB is jointly dominated by the blocks corresponding to the slot indices in Defs. More...
 

Protected Member Functions

const MachineFunctiongetMachineFunction ()
 Some getters to expose in a read-only way some private fields to subclasses. More...
 
const MachineRegisterInfogetRegInfo () const
 
SlotIndexesgetIndexes ()
 
MachineDominatorTreegetDomTree ()
 
VNInfo::AllocatorgetVNAlloc ()
 
void resetLiveOutMap ()
 Reset Map and Seen fields. More...
 

Detailed Description

Definition at line 46 of file LiveRangeCalc.h.

Constructor & Destructor Documentation

◆ LiveRangeCalc()

llvm::LiveRangeCalc::LiveRangeCalc ( )
default

Member Function Documentation

◆ addLiveInBlock()

void llvm::LiveRangeCalc::addLiveInBlock ( LiveRange LR,
MachineDomTreeNode DomNode,
SlotIndex  Kill = SlotIndex() 
)
inline

addLiveInBlock - Add a block with an unknown live-in value.

This function can only be called once per basic block. Once the live-in value has been determined, calculateValues() will add liveness to LI.

Parameters
LRThe live range that is live-in to the block.
DomNodeThe domtree node for the block.
KillIndex in block where LI is killed. If the value is live-through, set Kill = SLotIndex() and also call setLiveOutValue(MBB, 0).

Definition at line 244 of file LiveRangeCalc.h.

References llvm::RegState::Kill.

◆ calculateValues()

void LiveRangeCalc::calculateValues ( )

calculateValues - Calculate the value that will be live-in to each block added with addLiveInBlock.

Add PHI-def values as needed to preserve SSA form. Add liveness to all live-in blocks up to the Kill point, or the whole block for live-through blocks.

Every predecessor of a live-in block must have been given a value with setLiveOutValue, the value may be null for live-trough blocks.

Definition at line 117 of file LiveRangeCalc.cpp.

References assert().

Referenced by extend().

◆ extend()

void LiveRangeCalc::extend ( LiveRange LR,
SlotIndex  Use,
unsigned  PhysReg,
ArrayRef< SlotIndex Undefs 
)

Extend the live range of LR to reach Use.

The existing values in LR must be live so they jointly dominate Use. If Use is not dominated by a single existing value, PHI-defs are inserted as required to preserve SSA form.

PhysReg, when set, is used to verify live-in lists on basic blocks.

Definition at line 89 of file LiveRangeCalc.cpp.

References assert(), calculateValues(), llvm::LiveRange::extendInBlock(), llvm::SlotIndexes::getMBBFromIndex(), and llvm::SlotIndexes::getMBBStartIdx().

Referenced by llvm::LiveIntervals::extendToIndices().

◆ getDomTree()

MachineDominatorTree* llvm::LiveRangeCalc::getDomTree ( )
inlineprotected

Definition at line 170 of file LiveRangeCalc.h.

Referenced by llvm::LiveIntervalCalc::calculate().

◆ getIndexes()

SlotIndexes* llvm::LiveRangeCalc::getIndexes ( )
inlineprotected

◆ getMachineFunction()

const MachineFunction* llvm::LiveRangeCalc::getMachineFunction ( )
inlineprotected

Some getters to expose in a read-only way some private fields to subclasses.

Definition at line 167 of file LiveRangeCalc.h.

Referenced by llvm::LiveIntervalCalc::calculate().

◆ getRegInfo()

const MachineRegisterInfo* llvm::LiveRangeCalc::getRegInfo ( ) const
inlineprotected

Definition at line 168 of file LiveRangeCalc.h.

References MRI.

Referenced by llvm::LiveIntervalCalc::calculate(), and llvm::LiveIntervalCalc::createDeadDefs().

◆ getVNAlloc()

VNInfo::Allocator* llvm::LiveRangeCalc::getVNAlloc ( )
inlineprotected

◆ isJointlyDominated()

bool LiveRangeCalc::isJointlyDominated ( const MachineBasicBlock MBB,
ArrayRef< SlotIndex Defs,
const SlotIndexes Indexes 
)
static

A diagnostic function to check if the end of the block MBB is jointly dominated by the blocks corresponding to the slot indices in Defs.

This function is mainly for use in self-verification checks.

Definition at line 434 of file LiveRangeCalc.cpp.

References B, llvm::MachineFunction::getBlockNumbered(), llvm::SlotIndexes::getMBBFromIndex(), llvm::MachineBasicBlock::getNumber(), llvm::MachineFunction::getNumBlockIDs(), llvm::MachineBasicBlock::getParent(), i, I, llvm::SetVector< T, Vector, Set >::insert(), MBB, P, llvm::BitVector::set(), and llvm::SetVector< T, Vector, Set >::size().

◆ reset()

void LiveRangeCalc::reset ( const MachineFunction mf,
SlotIndexes SI,
MachineDominatorTree MDT,
VNInfo::Allocator VNIA 
)

reset - Prepare caches for a new set of non-overlapping live ranges.

The caches must be reset before attempting calculations with a live range that may overlap a previously computed live range, and before the first live range in a function. If live ranges are not known to be non-overlapping, call reset before each.

Definition at line 51 of file LiveRangeCalc.cpp.

References llvm::SmallVectorImpl< T >::clear(), llvm::MachineFunction::getRegInfo(), resetLiveOutMap(), and SI.

Referenced by llvm::LiveIntervalCalc::calculate(), llvm::LiveIntervals::constructMainRangeFromSubranges(), llvm::LiveIntervals::extendToIndices(), and llvm::SplitEditor::reset().

◆ resetLiveOutMap()

void LiveRangeCalc::resetLiveOutMap ( )
protected

◆ setLiveOutValue()

void llvm::LiveRangeCalc::setLiveOutValue ( MachineBasicBlock MBB,
VNInfo VNI 
)
inline

setLiveOutValue - Indicate that VNI is live out from MBB.

The calculateValues() function will not add liveness for MBB, the caller should take care of that.

VNI may be null only if MBB is a live-through block also passed to addLiveInBlock().

Definition at line 230 of file LiveRangeCalc.h.

References MBB, and llvm::BitVector::set().


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