Analysis that identifies uniform values in a data-parallel execution. More...

#include "llvm/ADT/GenericUniformityImpl.h"

Public Types
using	BlockT = typename ContextT::BlockT
using	FunctionT = typename ContextT::FunctionT
using	ValueRefT = typename ContextT::ValueRefT
using	ConstValueRefT = typename ContextT::ConstValueRefT
using	UseT = typename ContextT::UseT
using	InstructionT = typename ContextT::InstructionT
using	DominatorTreeT = typename ContextT::DominatorTreeT
using	CycleInfoT = GenericCycleInfo<ContextT>
using	SyncDependenceAnalysisT = GenericSyncDependenceAnalysis<ContextT>
using	DivergenceDescriptorT
using	TemporalDivergenceTuple

Public Member Functions
	GenericUniformityAnalysisImpl (const DominatorTreeT &DT, const CycleInfoT &CI, const TargetTransformInfo *TTI)
void	initialize ()
const FunctionT &	getFunction () const
const CycleInfoT &	getCycleInfo () const
void	addUniformOverride (const InstructionT &Instr)
	Mark `UniVal` as a value that is always uniform.
void	markDivergent (const InstructionT &I)
	Examine `I` for divergent outputs and add to the worklist.
bool	markDivergent (ConstValueRefT DivVal)
	Mark `DivVal` as a divergent value by removing it from UniformValues.
bool	markDefsDivergent (const InstructionT &Instr)
	Mark outputs of `Instr` as divergent.
void	compute ()
	Propagate divergence to all instructions in the region.
bool	isAlwaysUniform (const InstructionT &Instr) const
	Whether `Val` will always return a uniform value regardless of its operands.
bool	hasDivergentDefs (const InstructionT &I) const
bool	isDivergentTerminator (const InstructionT &I) const
bool	isDivergent (ConstValueRefT V) const
	Whether `Val` is divergent at its definition.
bool	isDivergentUse (const UseT &U) const
bool	hasDivergentTerminator (const BlockT &B) const
void	forgetValue (ConstValueRefT V)
	Call before erasing `V`, or a later instruction reusing its address may be misclassified as uniform.
void	print (raw_ostream &Out) const
bool	printDivergentArgs (raw_ostream &Out) const
	Print divergent arguments and return true if any were found.
void	recordTemporalDivergence (ConstValueRefT, const InstructionT *, CycleRef)
bool	isCustomUniform (const InstructionT &I) const
	Check if an instruction with Custom uniformity can be proven uniform based on its operands.
void	addCustomUniformityCandidate (const InstructionT *I)
	Add an instruction that requires custom uniformity analysis.
bool	hasDivergentDefs (const Instruction &I) const
bool	markDefsDivergent (const Instruction &Instr)
bool	printDivergentArgs (raw_ostream &OS) const
void	initialize ()
bool	isDivergentUse (const Use &U) const
bool	hasDivergentDefs (const MachineInstr &I) const
bool	markDefsDivergent (const MachineInstr &Instr)
void	initialize ()
bool	isDivergentUse (const MachineOperand &U) const

Public Attributes
SmallVector< TemporalDivergenceTuple, 8 >	TemporalDivergenceList

Protected Member Functions
void	analyzeControlDivergence (const InstructionT &Term)
	Mark `Term` as divergent and push all Instructions that become divergent as a result on the worklist.

Protected Attributes
const ContextT &	Context
const FunctionT &	F
const CycleInfoT &	CI
const TargetTransformInfo *	TTI = nullptr
bool	HasBranchDivergence = false
SmallPtrSet< const BlockT *, 32 >	DivergentTermBlocks
DenseSet< ConstValueRefT >	UniformValues
std::vector< const InstructionT * >	Worklist
SmallPtrSet< const InstructionT *, 8 >	CustomUniformityCandidates

Detailed Description

template<typename ContextT>
class llvm::GenericUniformityAnalysisImpl< ContextT >

Analysis that identifies uniform values in a data-parallel execution.

This analysis propagates divergence in a data-parallel context from sources of divergence to all users. It can be instantiated for an IR that provides a suitable SSAContext.

Definition at line 326 of file GenericUniformityImpl.h.

Member Typedef Documentation

◆ BlockT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::BlockT = typename ContextT::BlockT

Definition at line 328 of file GenericUniformityImpl.h.

◆ ConstValueRefT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::ConstValueRefT = typename ContextT::ConstValueRefT

Definition at line 331 of file GenericUniformityImpl.h.

◆ CycleInfoT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::CycleInfoT = GenericCycleInfo<ContextT>

Definition at line 336 of file GenericUniformityImpl.h.

◆ DivergenceDescriptorT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::DivergenceDescriptorT

Initial value:

typename SyncDependenceAnalysisT::DivergenceDescriptor

Definition at line 339 of file GenericUniformityImpl.h.

◆ DominatorTreeT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::DominatorTreeT = typename ContextT::DominatorTreeT

Definition at line 334 of file GenericUniformityImpl.h.

◆ FunctionT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::FunctionT = typename ContextT::FunctionT

Definition at line 329 of file GenericUniformityImpl.h.

◆ InstructionT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::InstructionT = typename ContextT::InstructionT

Definition at line 333 of file GenericUniformityImpl.h.

◆ SyncDependenceAnalysisT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::SyncDependenceAnalysisT = GenericSyncDependenceAnalysis<ContextT>

Definition at line 338 of file GenericUniformityImpl.h.

◆ TemporalDivergenceTuple

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::TemporalDivergenceTuple

Initial value:

std::tuple<ConstValueRefT, InstructionT *, CycleRef>

Definition at line 342 of file GenericUniformityImpl.h.

◆ UseT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::UseT = typename ContextT::UseT

Definition at line 332 of file GenericUniformityImpl.h.

◆ ValueRefT

template<typename ContextT>

using llvm::GenericUniformityAnalysisImpl< ContextT >::ValueRefT = typename ContextT::ValueRefT

Definition at line 330 of file GenericUniformityImpl.h.

Constructor & Destructor Documentation

◆ GenericUniformityAnalysisImpl()

template<typename ContextT>

llvm::GenericUniformityAnalysisImpl< ContextT >::GenericUniformityAnalysisImpl	(	const DominatorTreeT &	DT,
		const CycleInfoT &	CI,
		const TargetTransformInfo *	TTI )

inline

Definition at line 345 of file GenericUniformityImpl.h.

References CI, Context, F, getFunction(), and TTI.

Member Function Documentation

◆ addCustomUniformityCandidate()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::addCustomUniformityCandidate ( const InstructionT * I )

Add an instruction that requires custom uniformity analysis.

Definition at line 865 of file GenericUniformityImpl.h.

References CustomUniformityCandidates, and I.

Referenced by initialize().

◆ addUniformOverride()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::addUniformOverride ( const InstructionT & Instr )

Mark UniVal as a value that is always uniform.

Definition at line 859 of file GenericUniformityImpl.h.

Referenced by initialize().

◆ analyzeControlDivergence()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::analyzeControlDivergence ( const InstructionT & Term )

protected

Mark Term as divergent and push all Instructions that become divergent as a result on the worklist.

Definition at line 1101 of file GenericUniformityImpl.h.

References A(), assert(), B(), C(), CI, Context, llvm::dbgs(), DivergentTermBlocks, llvm::getOutermostDivergentCycle(), llvm::insertIfNotContained(), LLVM_DEBUG, llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::sort().

Referenced by compute().

◆ compute()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::compute ( )

Propagate divergence to all instructions in the region.

Divergence is seeded by calls to markDivergent.

Definition at line 1157 of file GenericUniformityImpl.h.

References analyzeControlDivergence(), assert(), Context, llvm::dbgs(), HasBranchDivergence, hasDivergentDefs(), I, LLVM_DEBUG, and Worklist.

◆ forgetValue()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::forgetValue ( ConstValueRefT V )

inline

Call before erasing V, or a later instruction reusing its address may be misclassified as uniform.

Definition at line 410 of file GenericUniformityImpl.h.

References UniformValues.

◆ getCycleInfo()

template<typename ContextT>

const CycleInfoT & llvm::GenericUniformityAnalysisImpl< ContextT >::getCycleInfo ( ) const

inline

Definition at line 354 of file GenericUniformityImpl.h.

References CI.

◆ getFunction()

template<typename ContextT>

const FunctionT & llvm::GenericUniformityAnalysisImpl< ContextT >::getFunction ( ) const

inline

Definition at line 352 of file GenericUniformityImpl.h.

References F.

Referenced by GenericUniformityAnalysisImpl().

◆ hasDivergentDefs() [1/3]

bool llvm::GenericUniformityAnalysisImpl< SSAContext >::hasDivergentDefs ( const Instruction & I ) const

Definition at line 22 of file UniformityAnalysis.cpp.

References I, and isDivergent().

◆ hasDivergentDefs() [2/3]

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::hasDivergentDefs ( const InstructionT & I ) const

References I.

Referenced by compute().

◆ hasDivergentDefs() [3/3]

bool llvm::GenericUniformityAnalysisImpl< MachineSSAContext >::hasDivergentDefs ( const MachineInstr & I ) const

Definition at line 22 of file MachineUniformityAnalysis.cpp.

References I, and isDivergent().

◆ hasDivergentTerminator()

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::hasDivergentTerminator ( const BlockT & B ) const

inline

Definition at line 404 of file GenericUniformityImpl.h.

References B(), and DivergentTermBlocks.

Referenced by print().

◆ initialize() [1/3]

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::initialize ( )

◆ initialize() [2/3]

void llvm::GenericUniformityAnalysisImpl< SSAContext >::initialize ( )

Definition at line 68 of file UniformityAnalysis.cpp.

References addCustomUniformityCandidate(), addUniformOverride(), llvm::AlwaysUniform, llvm::Custom, llvm::Default, DivergentTermBlocks, F, I, instructions, llvm::NeverUniform, llvm::SmallVectorTemplateBase< T, bool >::push_back(), TTI, UniformValues, and Worklist.

◆ initialize() [3/3]

void llvm::GenericUniformityAnalysisImpl< MachineSSAContext >::initialize ( )

Definition at line 50 of file MachineUniformityAnalysis.cpp.

References addUniformOverride(), llvm::AlwaysUniform, llvm::Custom, llvm::Default, F, markDivergent(), MBB, MI, llvm::NeverUniform, and UniformValues.

◆ isAlwaysUniform()

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::isAlwaysUniform ( const InstructionT & Instr ) const

Whether Val will always return a uniform value regardless of its operands.

Definition at line 1186 of file GenericUniformityImpl.h.

Referenced by markDivergent().

◆ isCustomUniform()

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::isCustomUniform ( const InstructionT & I ) const

Check if an instruction with Custom uniformity can be proven uniform based on its operands.

This queries the target-specific callback.

References I.

Referenced by markDivergent().

◆ isDivergent()

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::isDivergent ( ConstValueRefT V ) const

inline

Whether Val is divergent at its definition.

When the target has no branch divergence, compute() is never called and everything is uniform. Otherwise, values not in UniformValues (e.g. newly created) are conservatively treated as divergent.

Definition at line 390 of file GenericUniformityImpl.h.

References HasBranchDivergence, and UniformValues.

Referenced by hasDivergentDefs(), hasDivergentDefs(), isDivergentUse(), isDivergentUse(), print(), and printDivergentArgs().

◆ isDivergentTerminator()

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::isDivergentTerminator ( const InstructionT & I ) const

inline

Definition at line 381 of file GenericUniformityImpl.h.

References assert(), DivergentTermBlocks, and I.

◆ isDivergentUse() [1/3]

bool llvm::GenericUniformityAnalysisImpl< MachineSSAContext >::isDivergentUse ( const MachineOperand & U ) const

Definition at line 151 of file MachineUniformityAnalysis.cpp.

References F, and isDivergent().

◆ isDivergentUse() [2/3]

bool llvm::GenericUniformityAnalysisImpl< SSAContext >::isDivergentUse ( const Use & U ) const

Definition at line 137 of file UniformityAnalysis.cpp.

References llvm::cast(), llvm::dyn_cast(), and isDivergent().

◆ isDivergentUse() [3/3]

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::isDivergentUse ( const UseT & U ) const

◆ markDefsDivergent() [1/3]

bool llvm::GenericUniformityAnalysisImpl< SSAContext >::markDefsDivergent ( const Instruction & Instr )

Definition at line 28 of file UniformityAnalysis.cpp.

References llvm::cast(), and markDivergent().

◆ markDefsDivergent() [2/3]

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::markDefsDivergent ( const InstructionT & Instr )

Mark outputs of Instr as divergent.

Returns: Whether the tracked divergence state of any output has changed.

Referenced by markDivergent().

◆ markDefsDivergent() [3/3]

bool llvm::GenericUniformityAnalysisImpl< MachineSSAContext >::markDefsDivergent ( const MachineInstr & Instr )

Definition at line 32 of file MachineUniformityAnalysis.cpp.

References assert(), F, markDivergent(), and TRI.

◆ markDivergent() [1/2]

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::markDivergent ( const InstructionT & I )

Examine I for divergent outputs and add to the worklist.

Definition at line 822 of file GenericUniformityImpl.h.

References Context, CustomUniformityCandidates, llvm::dbgs(), DivergentTermBlocks, I, isAlwaysUniform(), isCustomUniform(), LLVM_DEBUG, markDefsDivergent(), and Worklist.

Referenced by initialize(), markDefsDivergent(), and markDefsDivergent().

◆ markDivergent() [2/2]

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::markDivergent ( ConstValueRefT DivVal )

Mark DivVal as a divergent value by removing it from UniformValues.

Returns: Whether the tracked divergence state of DivVal changed.

Definition at line 849 of file GenericUniformityImpl.h.

References Context, llvm::dbgs(), LLVM_DEBUG, and UniformValues.

◆ print()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::print ( raw_ostream & Out ) const

Definition at line 1205 of file GenericUniformityImpl.h.

References llvm::Block, C(), CI, Context, F, hasDivergentTerminator(), isDivergent(), printDivergentArgs(), T, and TemporalDivergenceList.

◆ printDivergentArgs() [1/2]

bool llvm::GenericUniformityAnalysisImpl< SSAContext >::printDivergentArgs ( raw_ostream & OS ) const

Definition at line 53 of file UniformityAnalysis.cpp.

References Context, F, and isDivergent().

◆ printDivergentArgs() [2/2]

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::printDivergentArgs ( raw_ostream & Out ) const

Print divergent arguments and return true if any were found.

IR specialization iterates F.args(); default is a no-op.

Definition at line 1192 of file GenericUniformityImpl.h.

Referenced by print().

◆ recordTemporalDivergence()

template<typename ContextT>

void llvm::GenericUniformityAnalysisImpl< ContextT >::recordTemporalDivergence	(	ConstValueRefT	Val,
		const InstructionT *	User,
		CycleRef	C )

Definition at line 1180 of file GenericUniformityImpl.h.

References C(), and TemporalDivergenceList.

Member Data Documentation

◆ CI

template<typename ContextT>

const CycleInfoT& llvm::GenericUniformityAnalysisImpl< ContextT >::CI

protected

Definition at line 432 of file GenericUniformityImpl.h.

Referenced by analyzeControlDivergence(), GenericUniformityAnalysisImpl(), getCycleInfo(), and print().

◆ Context

template<typename ContextT>

const ContextT& llvm::GenericUniformityAnalysisImpl< ContextT >::Context

protected

Definition at line 430 of file GenericUniformityImpl.h.

Referenced by analyzeControlDivergence(), compute(), GenericUniformityAnalysisImpl(), markDivergent(), markDivergent(), print(), and printDivergentArgs().

◆ CustomUniformityCandidates

template<typename ContextT>

SmallPtrSet<const InstructionT *, 8> llvm::GenericUniformityAnalysisImpl< ContextT >::CustomUniformityCandidates

protected

Definition at line 452 of file GenericUniformityImpl.h.

Referenced by addCustomUniformityCandidate(), and markDivergent().

◆ DivergentTermBlocks

template<typename ContextT>

SmallPtrSet<const BlockT *, 32> llvm::GenericUniformityAnalysisImpl< ContextT >::DivergentTermBlocks

protected

Definition at line 440 of file GenericUniformityImpl.h.

Referenced by analyzeControlDivergence(), hasDivergentTerminator(), initialize(), isDivergentTerminator(), and markDivergent().

◆ F

template<typename ContextT>

const FunctionT& llvm::GenericUniformityAnalysisImpl< ContextT >::F

protected

Definition at line 431 of file GenericUniformityImpl.h.

Referenced by GenericUniformityAnalysisImpl(), getFunction(), initialize(), isDivergentUse(), markDefsDivergent(), print(), and printDivergentArgs().

◆ HasBranchDivergence

template<typename ContextT>

bool llvm::GenericUniformityAnalysisImpl< ContextT >::HasBranchDivergence = false

protected

Definition at line 438 of file GenericUniformityImpl.h.

Referenced by compute(), and isDivergent().

◆ TemporalDivergenceList

template<typename ContextT>

SmallVector<TemporalDivergenceTuple, 8> llvm::GenericUniformityAnalysisImpl< ContextT >::TemporalDivergenceList

Definition at line 418 of file GenericUniformityImpl.h.

Referenced by print(), and recordTemporalDivergence().

◆ TTI

template<typename ContextT>

const TargetTransformInfo* llvm::GenericUniformityAnalysisImpl< ContextT >::TTI = nullptr

protected

Definition at line 433 of file GenericUniformityImpl.h.

Referenced by GenericUniformityAnalysisImpl(), and initialize().

◆ UniformValues

template<typename ContextT>

DenseSet<ConstValueRefT> llvm::GenericUniformityAnalysisImpl< ContextT >::UniformValues

protected

Definition at line 445 of file GenericUniformityImpl.h.

Referenced by forgetValue(), initialize(), isDivergent(), and markDivergent().

◆ Worklist

template<typename ContextT>

std::vector<const InstructionT *> llvm::GenericUniformityAnalysisImpl< ContextT >::Worklist

protected

Definition at line 448 of file GenericUniformityImpl.h.

Referenced by compute(), initialize(), and markDivergent().

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

include/llvm/ADT/GenericUniformityImpl.h

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ BlockT

◆ ConstValueRefT

◆ CycleInfoT

◆ DivergenceDescriptorT

◆ DominatorTreeT

◆ FunctionT

◆ InstructionT

◆ SyncDependenceAnalysisT

◆ TemporalDivergenceTuple

◆ UseT

◆ ValueRefT

Constructor & Destructor Documentation

◆ GenericUniformityAnalysisImpl()

Member Function Documentation

◆ addCustomUniformityCandidate()

◆ addUniformOverride()

◆ analyzeControlDivergence()

◆ compute()

◆ forgetValue()

◆ getCycleInfo()

◆ getFunction()

◆ hasDivergentDefs() [1/3]

◆ hasDivergentDefs() [2/3]

◆ hasDivergentDefs() [3/3]

◆ hasDivergentTerminator()

◆ initialize() [1/3]

◆ initialize() [2/3]

◆ initialize() [3/3]

◆ isAlwaysUniform()

◆ isCustomUniform()

◆ isDivergent()

◆ isDivergentTerminator()

◆ isDivergentUse() [1/3]

◆ isDivergentUse() [2/3]

◆ isDivergentUse() [3/3]

◆ markDefsDivergent() [1/3]

◆ markDefsDivergent() [2/3]

◆ markDefsDivergent() [3/3]

◆ markDivergent() [1/2]

◆ markDivergent() [2/2]

◆ print()

◆ printDivergentArgs() [1/2]

◆ printDivergentArgs() [2/2]

◆ recordTemporalDivergence()

Member Data Documentation

◆ CI

◆ Context

◆ CustomUniformityCandidates

◆ DivergentTermBlocks

◆ F

◆ HasBranchDivergence

◆ TemporalDivergenceList

◆ TTI

◆ UniformValues

◆ Worklist