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

SplitEditor - Edit machine code and LiveIntervals for live range splitting. More...

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

Public Types
enum ComplementSpillMode { SM_Partition, SM_Size, SM_Speed }
ComplementSpillMode - Select how the complement live range should be created. More...
Public Member Functions
SplitEditor (SplitAnalysis &SA, LiveIntervals &LIS, VirtRegMap &VRM, MachineDominatorTree &MDT, MachineBlockFrequencyInfo &MBFI, VirtRegAuxInfo &VRAI)
Create a new SplitEditor for editing the LiveInterval analyzed by SA.
void reset (LiveRangeEdit &, ComplementSpillMode=SM_Partition)
reset - Prepare for a new split.
unsigned openIntv ()
Create a new virtual register and live interval.
unsigned currentIntv () const
currentIntv - Return the current interval index.
void selectIntv (unsigned Idx)
selectIntv - Select a previously opened interval index.
SlotIndex enterIntvBefore (SlotIndex Idx)
enterIntvBefore - Enter the open interval before the instruction at Idx.
SlotIndex enterIntvAfter (SlotIndex Idx)
enterIntvAfter - Enter the open interval after the instruction at Idx.
SlotIndex enterIntvAtEnd (MachineBasicBlock &MBB)
enterIntvAtEnd - Enter the open interval at the end of MBB.
void useIntv (const MachineBasicBlock &MBB)
useIntv - indicate that all instructions in MBB should use OpenLI.
void useIntv (SlotIndex Start, SlotIndex End)
useIntv - indicate that all instructions in range should use OpenLI.
SlotIndex leaveIntvAfter (SlotIndex Idx)
leaveIntvAfter - Leave the open interval after the instruction at Idx.
SlotIndex leaveIntvBefore (SlotIndex Idx)
leaveIntvBefore - Leave the open interval before the instruction at Idx.
SlotIndex leaveIntvAtTop (MachineBasicBlock &MBB)
leaveIntvAtTop - Leave the interval at the top of MBB.
void overlapIntv (SlotIndex Start, SlotIndex End)
overlapIntv - Indicate that all instructions in range should use the open interval if End does not have tied-def usage of the register and in this case complement interval is used.
void finish (SmallVectorImpl< unsigned > *LRMap=nullptr)
finish - after all the new live ranges have been created, compute the remaining live range, and rewrite instructions to use the new registers.
void dump () const
dump - print the current interval mapping to dbgs().
void splitSingleBlock (const SplitAnalysis::BlockInfo &BI)
splitSingleBlock - Split CurLI into a separate live interval around the uses in a single block.
void splitLiveThroughBlock (unsigned MBBNum, unsigned IntvIn, SlotIndex LeaveBefore, unsigned IntvOut, SlotIndex EnterAfter)
splitLiveThroughBlock - Split CurLI in the given block such that it enters the block in IntvIn and leaves it in IntvOut.
void splitRegInBlock (const SplitAnalysis::BlockInfo &BI, unsigned IntvIn, SlotIndex LeaveBefore)
splitRegInBlock - Split CurLI in the given block such that it enters the block in IntvIn and leaves it on the stack (or not at all).
void splitRegOutBlock (const SplitAnalysis::BlockInfo &BI, unsigned IntvOut, SlotIndex EnterAfter)
splitRegOutBlock - Split CurLI in the given block such that it enters the block on the stack (or isn't live-in at all) and leaves it in IntvOut.

SplitEditor - Edit machine code and LiveIntervals for live range splitting.

Definition at line 263 of file SplitKit.h.

◆ ComplementSpillMode

ComplementSpillMode - Select how the complement live range should be created.

SplitEditor automatically creates interval 0 to contain anything that isn't added to another interval. This complement interval can get quite complicated, and it can sometimes be an advantage to allow it to overlap the other intervals. If it is going to spill anyway, no registers are wasted by keeping a value in two places at the same time.

Enumerator
SM_Partition SM_Partition(Default) - Try to create the complement interval so it doesn't overlap any other intervals, and the original interval is partitioned. This may require a large number of back copies and extra PHI-defs. Only segments marked with overlapIntv will be overlapping.
SM_Size SM_Size - Overlap intervals to minimize the number of inserted COPY instructions. Copies to the complement interval are hoisted to their common dominator, so only one COPY is required per value in the complement interval. This also means that no extra PHI-defs need to be inserted in the complement interval.
SM_Speed SM_Speed - Overlap intervals to minimize the expected execution frequency of the inserted copies. This is very similar to SM_Size, but the complement interval may get some extra PHI-defs.

Definition at line 281 of file SplitKit.h.

◆ currentIntv()

unsigned llvm::SplitEditor::currentIntv ( ) const inline

currentIntv - Return the current interval index.

Definition at line 465 of file SplitKit.h.

◆ dump()

◆ enterIntvAfter()

◆ enterIntvAtEnd()

◆ enterIntvBefore()

enterIntvBefore - Enter the open interval before the instruction at Idx.

If the parent interval is not live before Idx, a COPY is not inserted. Return the beginning of the new live range.

Definition at line 698 of file SplitKit.cpp.

References assert(), llvm::dbgs(), llvm::VNInfo::def, llvm::SlotIndex::getBaseIndex(), llvm::VNInfo::id, LLVM_DEBUG, and MI.

Referenced by splitLiveThroughBlock(), splitRegInBlock(), splitRegOutBlock(), and splitSingleBlock().

◆ finish()

finish - after all the new live ranges have been created, compute the remaining live range, and rewrite instructions to use the new registers.

Parameters

LRMap When not null, this vector will map each live range in Edit back to the indices returned by openIntv. There may be extra indices created by dead code elimination.

Definition at line 1536 of file SplitKit.cpp.

References assert(), llvm::SmallVectorImpl< T >::assign(), llvm::VNInfo::def, llvm::VNInfo::isUnused(), llvm::LiveInterval::removeEmptySubRanges(), llvm::LiveRange::RenumberValues(), llvm::SmallVectorImpl< T >::resize(), llvm::seq(), llvm::SmallVectorTemplateCommon< T, typename >::size(), SM_Partition, SM_Size, and SM_Speed.

◆ leaveIntvAfter()

◆ leaveIntvAtTop()

◆ leaveIntvBefore()

◆ openIntv()

◆ overlapIntv()

overlapIntv - Indicate that all instructions in range should use the open interval if End does not have tied-def usage of the register and in this case complement interval is used.

Let the complement interval be live.

This doubles the register pressure, but is sometimes required to deal with register uses after the last valid split point.

The Start index should be a return value from a leaveIntv* call, and End should be in the same basic block. The parent interval must have the same value across the range.

Definition at line 858 of file SplitKit.cpp.

References assert(), llvm::dbgs(), dump(), hasTiedUseOf(), LLVM_DEBUG, and MI.

Referenced by splitRegInBlock(), and splitSingleBlock().

◆ reset()

reset - Prepare for a new split.

Definition at line 366 of file SplitKit.cpp.

◆ selectIntv()

void SplitEditor::selectIntv ( unsigned Idx )

◆ splitLiveThroughBlock()

splitLiveThroughBlock - Split CurLI in the given block such that it enters the block in IntvIn and leaves it in IntvOut.

There may be uses in the block, but they will be ignored when placing split points.

Parameters

MBBNum Block number.
IntvIn Interval index entering the block.
LeaveBefore When set, leave IntvIn before this point.
IntvOut Interval index leaving the block.
EnterAfter When set, enter IntvOut after this point.

Definition at line 1667 of file SplitKit.cpp.

References assert(), llvm::dbgs(), enterIntvAfter(), enterIntvAtEnd(), enterIntvBefore(), llvm::SlotIndex::getBaseIndex(), llvm::SlotIndex::getBoundaryIndex(), leaveIntvAtTop(), leaveIntvBefore(), LLVM_DEBUG, MBB, selectIntv(), and useIntv().

◆ splitRegInBlock()

splitRegInBlock - Split CurLI in the given block such that it enters the block in IntvIn and leaves it on the stack (or not at all).

Split points are placed in a way that avoids putting uses in the stack interval. This may require creating a local interval when there is interference.

Parameters

BI Block descriptor.
IntvIn Interval index entering the block. Not 0.
LeaveBefore When set, leave IntvIn before this point.

Definition at line 1770 of file SplitKit.cpp.

References assert(), llvm::dbgs(), enterIntvBefore(), llvm::SplitAnalysis::BlockInfo::FirstInstr, llvm::SlotIndex::getBoundaryIndex(), llvm::SplitAnalysis::BlockInfo::LastInstr, leaveIntvAfter(), leaveIntvBefore(), llvm::SplitAnalysis::BlockInfo::LiveIn, llvm::SplitAnalysis::BlockInfo::LiveOut, LLVM_DEBUG, llvm::SplitAnalysis::BlockInfo::MBB, openIntv(), overlapIntv(), llvm::printMBBReference(), selectIntv(), and useIntv().

◆ splitRegOutBlock()

splitRegOutBlock - Split CurLI in the given block such that it enters the block on the stack (or isn't live-in at all) and leaves it in IntvOut.

Split points are placed to avoid interference and such that the uses are not in the stack interval. This may require creating a local interval when there is interference.

Parameters

BI Block descriptor.
IntvOut Interval index leaving the block.
EnterAfter When set, enter IntvOut after this point.

Definition at line 1863 of file SplitKit.cpp.

References assert(), llvm::dbgs(), enterIntvAfter(), enterIntvBefore(), llvm::SplitAnalysis::BlockInfo::FirstInstr, llvm::SlotIndex::getBaseIndex(), llvm::SplitAnalysis::BlockInfo::LastInstr, llvm::SplitAnalysis::BlockInfo::LiveIn, llvm::SplitAnalysis::BlockInfo::LiveOut, LLVM_DEBUG, llvm::SplitAnalysis::BlockInfo::MBB, openIntv(), llvm::printMBBReference(), selectIntv(), and useIntv().

◆ splitSingleBlock()

splitSingleBlock - Split CurLI into a separate live interval around the uses in a single block.

This is intended to be used as part of a larger split, and doesn't call finish().

Definition at line 1641 of file SplitKit.cpp.

References enterIntvBefore(), llvm::SplitAnalysis::BlockInfo::FirstInstr, llvm::SplitAnalysis::BlockInfo::LastInstr, leaveIntvAfter(), leaveIntvBefore(), llvm::SplitAnalysis::BlockInfo::LiveOut, llvm::SplitAnalysis::BlockInfo::MBB, openIntv(), overlapIntv(), and useIntv().

◆ useIntv() [1/2]

◆ useIntv() [2/2]

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