llvm::DivergenceAnalysisImpl Class Reference

Generic divergence analysis for reducible CFGs. More...

#include "llvm/Analysis/DivergenceAnalysis.h"

Public Member Functions
	DivergenceAnalysisImpl (const Function &F, const Loop *RegionLoop, const DominatorTree &DT, const LoopInfo &LI, SyncDependenceAnalysis &SDA, bool IsLCSSAForm)
	This instance will analyze the whole function F or the loop RegionLoop.
const Loop *	getRegionLoop () const
	The loop that defines the analyzed region (if any).
const Function &	getFunction () const
bool	inRegion (const BasicBlock &BB) const
	Whether BB is part of the region.
bool	inRegion (const Instruction &I) const
	Whether I is part of the region.
void	addUniformOverride (const Value &UniVal)
	Mark UniVal as a value that is always uniform.
bool	markDivergent (const Value &DivVal)
	Mark DivVal as a value that is always divergent.
void	compute ()
	Propagate divergence to all instructions in the region.
bool	hasDetectedDivergence () const
	Whether any value was marked or analyzed to be divergent.
bool	isAlwaysUniform (const Value &Val) const
	Whether Val will always return a uniform value regardless of its operands.
bool	isDivergent (const Value &Val) const
	Whether Val is divergent at its definition.
bool	isDivergentUse (const Use &U) const
	Whether U is divergent.

Detailed Description

Generic divergence analysis for reducible CFGs.

This analysis propagates divergence in a data-parallel context from sources of divergence to all users. It requires reducible CFGs. All assignments should be in SSA form.

Definition at line 36 of file DivergenceAnalysis.h.

Constructor & Destructor Documentation

DivergenceAnalysisImpl()

DivergenceAnalysisImpl::DivergenceAnalysisImpl	(	const Function &	F,
		const Loop *	RegionLoop,
		const DominatorTree &	DT,
		const LoopInfo &	LI,
		SyncDependenceAnalysis &	SDA,
		bool	IsLCSSAForm
	)

This instance will analyze the whole function F or the loop RegionLoop.

Parameters

RegionLoop	if non-null the analysis is restricted to RegionLoop. Otherwise the whole function is analyzed.
IsLCSSAForm	whether the analysis may assume that the IR in the region in LCSSA form.

Definition at line 92 of file DivergenceAnalysis.cpp.

Member Function Documentation

addUniformOverride()

void DivergenceAnalysisImpl::addUniformOverride

(

const Value &

UniVal

)

Mark UniVal as a value that is always uniform.

Definition at line 106 of file DivergenceAnalysis.cpp.

References llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::insert().

compute()

void DivergenceAnalysisImpl::compute

(

)

Propagate divergence to all instructions in the region.

Divergence is seeded by calls to markDivergent.

Definition at line 312 of file DivergenceAnalysis.cpp.

References assert(), I, and isDivergent().

getFunction()

const Function & llvm::DivergenceAnalysisImpl::getFunction ( ) const

inline

Definition at line 51 of file DivergenceAnalysis.h.

References F.

getRegionLoop()

const Loop * llvm::DivergenceAnalysisImpl::getRegionLoop ( ) const

inline

The loop that defines the analyzed region (if any).

Definition at line 50 of file DivergenceAnalysis.h.

hasDetectedDivergence()

bool llvm::DivergenceAnalysisImpl::hasDetectedDivergence ( ) const

inline

Whether any value was marked or analyzed to be divergent.

Definition at line 71 of file DivergenceAnalysis.h.

References llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::empty().

inRegion() [1/2]

bool DivergenceAnalysisImpl::inRegion

(

const BasicBlock &

BB

)

const

Whether BB is part of the region.

Definition at line 131 of file DivergenceAnalysis.cpp.

References llvm::LoopBase< BlockT, LoopT >::contains(), and llvm::BasicBlock::getParent().

Referenced by inRegion().

inRegion() [2/2]

bool DivergenceAnalysisImpl::inRegion

(

const Instruction &

I

)

const

Whether I is part of the region.

Definition at line 127 of file DivergenceAnalysis.cpp.

References I, and inRegion().

isAlwaysUniform()

bool DivergenceAnalysisImpl::isAlwaysUniform

(

const Value &

Val

)

const

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

Definition at line 332 of file DivergenceAnalysis.cpp.

References llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::contains().

Referenced by markDivergent().

isDivergent()

bool DivergenceAnalysisImpl::isDivergent

(

const Value &

Val

)

const

Whether Val is divergent at its definition.

Definition at line 336 of file DivergenceAnalysis.cpp.

References llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::contains().

Referenced by compute(), and isDivergentUse().

isDivergentUse()

bool DivergenceAnalysisImpl::isDivergentUse

(

const Use &

U

)

const

Whether U is divergent.

Uses of a uniform value can be divergent.

Definition at line 340 of file DivergenceAnalysis.cpp.

References I, and isDivergent().

markDivergent()

bool DivergenceAnalysisImpl::markDivergent

(

const Value &

DivVal

)

Mark DivVal as a value that is always divergent.

Will not do so if isAlwaysUniform(DivVal).

Returns

Whether the tracked divergence state of DivVal changed.

Definition at line 98 of file DivergenceAnalysis.cpp.

References assert(), llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::insert(), and isAlwaysUniform().

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

• include/llvm/Analysis/DivergenceAnalysis.h
• lib/Analysis/DivergenceAnalysis.cpp