#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)
	Returns true if `DefMI` precedes `UseMI` or they are the same instruction. More...

bool	dominates (MachineInstr &DefMI, MachineInstr &UseMI)
	Returns true if `DefMI` dominates `UseMI`. More...

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	matchElideBrByInvertingCond (MachineInstr &MI)

void	applyElideBrByInvertingCond (MachineInstr &MI)

bool	tryElideBrByInvertingCond (MachineInstr &MI)

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

bool	matchCombineConcatVectors (MachineInstr &MI, bool &IsUndef, SmallVectorImpl< Register > &Ops)
	Check if the G_CONCAT_VECTORS `MI` is undef or if it can be flattened into a build_vector. More...

void	applyCombineConcatVectors (MachineInstr &MI, bool IsUndef, const ArrayRef< Register > Ops)
	Replace `MI` with a flattened build_vector with `Ops` or an implicit_def if IsUndef is true. More...

bool	tryCombineShuffleVector (MachineInstr &MI)
	Try to combine G_SHUFFLE_VECTOR into G_CONCAT_VECTORS. More...

bool	matchCombineShuffleVector (MachineInstr &MI, SmallVectorImpl< Register > &Ops)
	Check if the G_SHUFFLE_VECTOR `MI` can be replaced by a concat_vectors. More...

void	applyCombineShuffleVector (MachineInstr &MI, const ArrayRef< Register > Ops)
	Replace `MI` with a concat_vectors with `Ops`. More...

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

◆ applyCombineConcatVectors()

void CombinerHelper::applyCombineConcatVectors	(	MachineInstr &	MI,
		bool	IsUndef,
		const ArrayRef< Register >	Ops
	)

Replace MI with a flattened build_vector with Ops or an implicit_def if IsUndef is true.

Definition at line 154 of file CombinerHelper.cpp.

References llvm::MachineIRBuilder::buildBuildVector(), Builder, llvm::MachineIRBuilder::buildUndef(), llvm::MachineRegisterInfo::cloneVirtualRegister(), llvm::MachineInstr::eraseFromParent(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), MI, MRI, replaceRegWith(), and llvm::MachineIRBuilder::setInsertPt().

Referenced by tryCombineConcatVectors().

◆ applyCombineCopy()

void CombinerHelper::applyCombineCopy ( MachineInstr & MI )

Definition at line 85 of file CombinerHelper.cpp.

References llvm::MachineInstr::eraseFromParent(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), MRI, and replaceRegWith().

Referenced by tryCombineCopy().

◆ applyCombineExtendingLoads()

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

rewrites to:

Definition at line 423 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().

◆ applyCombineShuffleVector()

void CombinerHelper::applyCombineShuffleVector	(	MachineInstr &	MI,
		const ArrayRef< Register >	Ops
	)

Replace MI with a concat_vectors with Ops.

Definition at line 251 of file CombinerHelper.cpp.

References llvm::MachineIRBuilder::buildConcatVectors(), Builder, llvm::MachineRegisterInfo::cloneVirtualRegister(), DefMI, llvm::MachineInstr::eraseFromParent(), llvm::PreferredTuple::ExtendOpcode, function, llvm::MachineBasicBlock::getFirstNonPHI(), llvm::MachineOperand::getMBB(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getParent(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), llvm::LLT::getSizeInBits(), llvm::MachineInstr::isPHI(), llvm::LLT::isValid(), MI, MRI, replaceRegWith(), llvm::MachineIRBuilder::setInsertPt(), llvm::PreferredTuple::Ty, and UseMI.

Referenced by tryCombineShuffleVector().

◆ applyElideBrByInvertingCond()

void CombinerHelper::applyElideBrByInvertingCond ( MachineInstr & MI )

Definition at line 782 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(), MRI, Observer, llvm::MachineOperand::setMBB(), and llvm::MachineOperand::setPredicate().

Referenced by tryElideBrByInvertingCond().

◆ 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 546 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 533 of file CombinerHelper.cpp.

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

Referenced by dominates().

◆ matchCombineConcatVectors()

bool CombinerHelper::matchCombineConcatVectors	(	MachineInstr &	MI,
		bool &	IsUndef,
		SmallVectorImpl< Register > &	Ops
	)

Check if the G_CONCAT_VECTORS MI is undef or if it can be flattened into a build_vector.

In the first case IsUndef will be true. In the second case Ops will contain the operands needed to produce the flattened build_vector.

Precondition: MI.getOpcode() == G_CONCAT_VECTORS.

Definition at line 102 of file CombinerHelper.cpp.

References assert(), Builder, llvm::MachineIRBuilder::buildUndef(), llvm::tgtok::Def, llvm::LLT::getNumElements(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getParent(), llvm::MachineOperand::getReg(), llvm::LLT::getScalarType(), llvm::MachineRegisterInfo::getType(), llvm::MachineRegisterInfo::getVRegDef(), MI, MRI, llvm::MachineInstr::operands(), llvm::SmallVectorTemplateBase< T >::push_back(), Reg, llvm::MachineIRBuilder::setInsertPt(), and llvm::RegState::Undef.

Referenced by tryCombineConcatVectors().

◆ 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 357 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().

◆ matchCombineShuffleVector()

bool CombinerHelper::matchCombineShuffleVector	(	MachineInstr &	MI,
		SmallVectorImpl< Register > &	Ops
	)

Check if the G_SHUFFLE_VECTOR MI can be replaced by a concat_vectors.

Ops will contain the operands needed to produce the flattened concat_vectors.

Precondition: MI.getOpcode() == G_SHUFFLE_VECTOR.

Definition at line 185 of file CombinerHelper.cpp.

References assert(), Builder, llvm::MachineIRBuilder::buildUndef(), llvm::LLT::getNumElements(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getParent(), llvm::MachineInstrBuilder::getReg(), llvm::MachineOperand::getReg(), llvm::MachineOperand::getShuffleMask(), llvm::ShuffleVectorInst::getShuffleMask(), llvm::MachineRegisterInfo::getType(), llvm::BitmaskEnumDetail::Mask(), MI, MRI, llvm::SmallVectorTemplateBase< T >::push_back(), and llvm::MachineIRBuilder::setInsertPt().

Referenced by tryCombineShuffleVector().

◆ matchElideBrByInvertingCond()

bool CombinerHelper::matchElideBrByInvertingCond ( MachineInstr & MI )

Definition at line 735 of file CombinerHelper.cpp.

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

Referenced by tryElideBrByInvertingCond().

◆ 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 applyCombineConcatVectors(), applyCombineCopy(), applyCombineExtendingLoads(), and applyCombineShuffleVector().

◆ 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 1298 of file CombinerHelper.cpp.

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

◆ tryCombineConcatVectors()

bool CombinerHelper::tryCombineConcatVectors ( MachineInstr & MI )

If MI is G_CONCAT_VECTORS, try to combine it.

Returns true if MI changed. Right now, we support:

concat_vector(undef, undef) => undef
concat_vector(build_vector(A, B), build_vector(C, D)) => build_vector(A, B, C, D)

Precondition: MI.getOpcode() == G_CONCAT_VECTORS.

Definition at line 92 of file CombinerHelper.cpp.

References applyCombineConcatVectors(), and matchCombineConcatVectors().

◆ 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 348 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 683 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 1247 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.

◆ tryCombineShuffleVector()

bool CombinerHelper::tryCombineShuffleVector ( MachineInstr & MI )

Try to combine G_SHUFFLE_VECTOR into G_CONCAT_VECTORS.

Returns true if MI changed.

Precondition: MI.getOpcode() == G_SHUFFLE_VECTOR.

Definition at line 176 of file CombinerHelper.cpp.

References applyCombineShuffleVector(), and matchCombineShuffleVector().

◆ tryElideBrByInvertingCond()

bool CombinerHelper::tryElideBrByInvertingCond ( MachineInstr & MI )

Definition at line 775 of file CombinerHelper.cpp.

References applyElideBrByInvertingCond(), and matchElideBrByInvertingCond().

Member Data Documentation

◆ Builder

MachineIRBuilder& llvm::CombinerHelper::Builder

protected

Definition at line 41 of file CombinerHelper.h.

Referenced by applyCombineConcatVectors(), applyCombineExtendingLoads(), applyCombineShuffleVector(), matchCombineConcatVectors(), matchCombineShuffleVector(), 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 applyCombineConcatVectors(), applyCombineCopy(), applyCombineExtendingLoads(), applyCombineShuffleVector(), applyElideBrByInvertingCond(), dominates(), getMemsetValue(), matchCombineConcatVectors(), matchCombineCopy(), matchCombineExtendingLoads(), matchCombineShuffleVector(), matchElideBrByInvertingCond(), tryCombineIndexedLoadStore(), and tryCombineMemCpyFamily().

◆ Observer

GISelChangeObserver& llvm::CombinerHelper::Observer

protected

Definition at line 43 of file CombinerHelper.h.

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

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

◆ applyCombineConcatVectors()

◆ applyCombineCopy()

◆ applyCombineExtendingLoads()

◆ applyCombineShuffleVector()

◆ applyElideBrByInvertingCond()

◆ dominates()

◆ isPredecessor()

◆ matchCombineConcatVectors()

◆ matchCombineCopy()

◆ matchCombineExtendingLoads()

◆ matchCombineShuffleVector()

◆ matchElideBrByInvertingCond()

◆ replaceRegOpWith()

◆ replaceRegWith()

◆ tryCombine()

◆ tryCombineConcatVectors()

◆ tryCombineCopy()

◆ tryCombineExtendingLoads()

◆ tryCombineIndexedLoadStore()

◆ tryCombineMemCpyFamily()

◆ tryCombineShuffleVector()

◆ tryElideBrByInvertingCond()

Member Data Documentation

◆ Builder

◆ KB

◆ MDT

◆ MRI

◆ Observer