#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"

Collaboration diagram for llvm::CombinerHelper:

[legend]

Public Member Functions
	CombinerHelper (GISelChangeObserver &Observer, MachineIRBuilder &B, GISelKnownBits KB=nullptr, MachineDominatorTree MDT=nullptr)

void	replaceRegWith (MachineRegisterInfo &MRI, Register FromReg, Register ToReg) const
	MachineRegisterInfo::replaceRegWith() and inform the observer of the changes. More...

void	replaceRegOpWith (MachineRegisterInfo &MRI, MachineOperand &FromRegOp, Register ToReg) const
	Replace a single register operand with a new register and inform the observer of the changes. More...

bool	tryCombineCopy (MachineInstr &MI)
	If `MI` is COPY, try to combine it. More...

bool	matchCombineCopy (MachineInstr &MI)

void	applyCombineCopy (MachineInstr &MI)

bool	isPredecessor (MachineInstr &DefMI, MachineInstr &UseMI)

bool	dominates (MachineInstr &DefMI, MachineInstr &UseMI)

bool	tryCombineExtendingLoads (MachineInstr &MI)
	If `MI` is extend that consumes the result of a load, try to combine it. More...

bool	matchCombineExtendingLoads (MachineInstr &MI, PreferredTuple &MatchInfo)

void	applyCombineExtendingLoads (MachineInstr &MI, PreferredTuple &MatchInfo)

bool	tryCombineIndexedLoadStore (MachineInstr &MI)
	Combine `MI` into a pre-indexed or post-indexed load/store operation if legal and the surrounding code makes it useful. More...

bool	matchCombineBr (MachineInstr &MI)

bool	tryCombineBr (MachineInstr &MI)

bool	tryCombineMemCpyFamily (MachineInstr &MI, unsigned MaxLen=0)
	Optimize memcpy intrinsics et al, e.g. More...

bool	tryCombine (MachineInstr &MI)
	Try to transform `MI` by using all of the above combine functions. More...

Protected Attributes
MachineIRBuilder &	Builder

MachineRegisterInfo &	MRI

GISelChangeObserver &	Observer

GISelKnownBits *	KB

MachineDominatorTree *	MDT

Detailed Description

Definition at line 39 of file CombinerHelper.h.

Constructor & Destructor Documentation

◆ CombinerHelper()

CombinerHelper::CombinerHelper	(	GISelChangeObserver &	Observer,
		MachineIRBuilder &	B,
		GISelKnownBits *	KB = `nullptr`,
		MachineDominatorTree *	MDT = `nullptr`
	)

Definition at line 34 of file CombinerHelper.cpp.

Member Function Documentation

◆ applyCombineCopy()

void CombinerHelper::applyCombineCopy ( MachineInstr & MI )

◆ applyCombineExtendingLoads()

void CombinerHelper::applyCombineExtendingLoads	(	MachineInstr &	MI,
		PreferredTuple &	MatchInfo
	)

rewrites to:

Definition at line 252 of file CombinerHelper.cpp.

References Builder, llvm::MachineIRBuilder::buildTrunc(), llvm::GISelChangeObserver::changedInstr(), llvm::GISelChangeObserver::changingInstr(), llvm::MachineRegisterInfo::cloneVirtualRegister(), llvm::GISelChangeObserver::erasingInstr(), llvm::PreferredTuple::ExtendOpcode, llvm::MCInstrInfo::get(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), llvm::LLT::getSizeInBits(), llvm::MachineIRBuilder::getTII(), llvm::MachineRegisterInfo::getType(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::lookup(), llvm::PreferredTuple::MI, MRI, Observer, llvm::SmallVectorTemplateBase< T >::push_back(), replaceRegOpWith(), replaceRegWith(), llvm::MachineInstr::setDesc(), llvm::MachineIRBuilder::setInsertPt(), llvm::MachineOperand::setReg(), llvm::PreferredTuple::Ty, llvm::MachineRegisterInfo::use_operands(), and UseMI.

Referenced by tryCombineExtendingLoads().

◆ dominates()

bool CombinerHelper::dominates	(	MachineInstr &	DefMI,
		MachineInstr &	UseMI
	)

Returns: true if DefMI dominates UseMI. By definition an instruction dominates itself.

If we haven't been provided with a MachineDominatorTree during construction, this function returns a conservative result that tracks just a single basic block.

Definition at line 375 of file CombinerHelper.cpp.

References assert(), llvm::dbgs(), llvm::MachineDominatorTree::dominates(), ForceLegalIndexing, llvm::getDefIgnoringCopies(), llvm::MachineInstr::getOpcode(), llvm::getOpcodeDef(), llvm::MachineInstr::getOperand(), llvm::MachineBasicBlock::getParent(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), llvm::MachineFunction::getSubtarget(), llvm::TargetSubtargetInfo::getTargetLowering(), llvm::MachineRegisterInfo::getUniqueVRegDef(), llvm::MachineRegisterInfo::hasOneUse(), isPredecessor(), LLVM_DEBUG, MDT, MI, MRI, llvm::MachineRegisterInfo::use_instructions(), and UseMI.

◆ isPredecessor()

bool CombinerHelper::isPredecessor	(	MachineInstr &	DefMI,
		MachineInstr &	UseMI
	)

Returns: true if DefMI precedes UseMI or they are the same instruction. Both must be in the same basic block.

Definition at line 362 of file CombinerHelper.cpp.

References assert(), llvm::MachineBasicBlock::begin(), llvm::MachineInstr::getParent(), I, llvm_unreachable, and UseMI.

Referenced by dominates().

◆ matchCombineBr()

bool CombinerHelper::matchCombineBr ( MachineInstr & MI )

Definition at line 564 of file CombinerHelper.cpp.

References assert(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), llvm::MachineRegisterInfo::getVRegDef(), llvm::MachineRegisterInfo::hasOneUse(), and MRI.

Referenced by tryCombineBr().

◆ matchCombineCopy()

bool CombinerHelper::matchCombineCopy ( MachineInstr & MI )

Definition at line 72 of file CombinerHelper.cpp.

References llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), llvm::MachineRegisterInfo::getType(), llvm::LLT::isValid(), and MRI.

Referenced by tryCombineCopy().

◆ matchCombineExtendingLoads()

bool CombinerHelper::matchCombineExtendingLoads	(	MachineInstr &	MI,
		PreferredTuple &	MatchInfo
	)

Definition at line 186 of file CombinerHelper.cpp.

References assert(), llvm::dbgs(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstrBuilder::getReg(), llvm::MachineRegisterInfo::getType(), llvm::isPowerOf2_32(), LLVM_DEBUG, llvm::PreferredTuple::MI, MRI, llvm::PreferredTuple::Ty, llvm::MachineRegisterInfo::use_instructions(), and UseMI.

Referenced by tryCombineExtendingLoads().

◆ replaceRegOpWith()

void CombinerHelper::replaceRegOpWith	(	MachineRegisterInfo &	MRI,
		MachineOperand &	FromRegOp,
		Register	ToReg
	)		const

Replace a single register operand with a new register and inform the observer of the changes.

Definition at line 54 of file CombinerHelper.cpp.

References assert(), llvm::GISelChangeObserver::changedInstr(), llvm::GISelChangeObserver::changingInstr(), llvm::MachineOperand::getParent(), Observer, and llvm::MachineOperand::setReg().

Referenced by applyCombineExtendingLoads().

◆ replaceRegWith()

void CombinerHelper::replaceRegWith	(	MachineRegisterInfo &	MRI,
		Register	FromReg,
		Register	ToReg
	)		const

MachineRegisterInfo::replaceRegWith() and inform the observer of the changes.

Definition at line 42 of file CombinerHelper.cpp.

References llvm::MachineIRBuilder::buildCopy(), Builder, llvm::GISelChangeObserver::changingAllUsesOfReg(), llvm::MachineRegisterInfo::constrainRegAttrs(), llvm::GISelChangeObserver::finishedChangingAllUsesOfReg(), Observer, and llvm::MachineRegisterInfo::replaceRegWith().

Referenced by applyCombineCopy(), and applyCombineExtendingLoads().

◆ tryCombine()

bool CombinerHelper::tryCombine ( MachineInstr & MI )

Try to transform MI by using all of the above combine functions.

Returns true if changed.

Definition at line 1119 of file CombinerHelper.cpp.

References tryCombineCopy(), tryCombineExtendingLoads(), and tryCombineIndexedLoadStore().

◆ tryCombineBr()

bool CombinerHelper::tryCombineBr ( MachineInstr & MI )

Definition at line 602 of file CombinerHelper.cpp.

References llvm::GISelChangeObserver::changedInstr(), llvm::GISelChangeObserver::changingInstr(), llvm::MachineInstr::eraseFromParent(), llvm::CmpInst::getInversePredicate(), llvm::MachineOperand::getMBB(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getPredicate(), llvm::MachineOperand::getReg(), llvm::MachineRegisterInfo::getVRegDef(), matchCombineBr(), MRI, Observer, llvm::MachineOperand::setMBB(), and llvm::MachineOperand::setPredicate().

◆ tryCombineCopy()

bool CombinerHelper::tryCombineCopy ( MachineInstr & MI )

If MI is COPY, try to combine it.

Returns true if MI changed.

Definition at line 65 of file CombinerHelper.cpp.

References applyCombineCopy(), and matchCombineCopy().

Referenced by tryCombine().

◆ tryCombineExtendingLoads()

bool CombinerHelper::tryCombineExtendingLoads ( MachineInstr & MI )

If MI is extend that consumes the result of a load, try to combine it.

Returns true if MI changed.

Definition at line 177 of file CombinerHelper.cpp.

References applyCombineExtendingLoads(), and matchCombineExtendingLoads().

Referenced by tryCombine().

◆ tryCombineIndexedLoadStore()

bool CombinerHelper::tryCombineIndexedLoadStore ( MachineInstr & MI )

Combine MI into a pre-indexed or post-indexed load/store operation if legal and the surrounding code makes it useful.

Definition at line 512 of file CombinerHelper.cpp.

References llvm::MachineInstrBuilder::addDef(), llvm::MachineInstrBuilder::addImm(), llvm::MachineInstrBuilder::addUse(), llvm::MachineIRBuilder::buildInstr(), llvm::dbgs(), llvm::MachineInstr::eraseFromParent(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), llvm::MachineRegisterInfo::getUniqueVRegDef(), LLVM_DEBUG, llvm_unreachable, and MRI.

Referenced by tryCombine().

◆ tryCombineMemCpyFamily()

bool CombinerHelper::tryCombineMemCpyFamily	(	MachineInstr &	MI,
		unsigned	MaxLen = `0`
	)

Optimize memcpy intrinsics et al, e.g.

constant len calls. /p MaxLen if non-zero specifies the max length of a mem libcall to inline.

For example (pre-indexed):

$addr = G_GEP $base, $offset
[...]
$val = G_LOAD $addr
[...]
$whatever = COPY $addr

–>

$val, $addr = G_INDEXED_LOAD $base, $offset, 1 (IsPre)
[...]
$whatever = COPY $addr

or (post-indexed):

G_STORE $val, $base
[...]
$addr = G_GEP $base, $offset
[...]
$whatever = COPY $addr

–>

$addr = G_INDEXED_STORE $val, $base, $offset
[...]
$whatever = COPY $addr

Definition at line 1068 of file CombinerHelper.cpp.

References assert(), llvm::MachineInstr::eraseFromParent(), llvm::MachineMemOperand::getBaseAlignment(), llvm::getConstantVRegValWithLookThrough(), llvm::MachineInstr::getIntrinsicID(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), llvm::MachineMemOperand::isVolatile(), llvm::MachineInstr::memoperands_begin(), llvm::MachineInstr::memoperands_end(), and MRI.

Member Data Documentation

◆ Builder

MachineIRBuilder& llvm::CombinerHelper::Builder

protected

Definition at line 41 of file CombinerHelper.h.

Referenced by applyCombineCopy(), applyCombineExtendingLoads(), and replaceRegWith().

◆ KB

GISelKnownBits* llvm::CombinerHelper::KB

protected

Definition at line 44 of file CombinerHelper.h.

◆ MDT

MachineDominatorTree* llvm::CombinerHelper::MDT

protected

Definition at line 45 of file CombinerHelper.h.

Referenced by dominates().

◆ MRI

MachineRegisterInfo& llvm::CombinerHelper::MRI

protected

Definition at line 42 of file CombinerHelper.h.

Referenced by applyCombineCopy(), applyCombineExtendingLoads(), dominates(), getMemsetValue(), matchCombineBr(), matchCombineCopy(), matchCombineExtendingLoads(), tryCombineBr(), tryCombineIndexedLoadStore(), and tryCombineMemCpyFamily().

◆ Observer

GISelChangeObserver& llvm::CombinerHelper::Observer

protected

Definition at line 43 of file CombinerHelper.h.

Referenced by applyCombineExtendingLoads(), replaceRegOpWith(), replaceRegWith(), and tryCombineBr().

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

include/llvm/CodeGen/GlobalISel/CombinerHelper.h
lib/CodeGen/GlobalISel/CombinerHelper.cpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CombinerHelper()

Member Function Documentation

◆ applyCombineCopy()

◆ applyCombineExtendingLoads()

◆ dominates()

◆ isPredecessor()

◆ matchCombineBr()

◆ matchCombineCopy()

◆ matchCombineExtendingLoads()

◆ replaceRegOpWith()

◆ replaceRegWith()

◆ tryCombine()

◆ tryCombineBr()

◆ tryCombineCopy()

◆ tryCombineExtendingLoads()

◆ tryCombineIndexedLoadStore()

◆ tryCombineMemCpyFamily()

Member Data Documentation

◆ Builder

◆ KB

◆ MDT

◆ MRI

◆ Observer