GenericUniformityImpl.h File Reference

Implementation of uniformity analysis. More...

#include "llvm/ADT/GenericUniformityInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SparseBitVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <set>

Go to the source code of this file.

Classes
class	llvm::ModifiedPostOrder< ContextT >
	Construct a specially modified post-order traversal of cycles. More...
class	llvm::GenericSyncDependenceAnalysis< ContextT >
	Locate join blocks for disjoint paths starting at a divergent branch. More...
struct	llvm::GenericSyncDependenceAnalysis< ContextT >::DivergenceDescriptor
	Information discovered by the sync dependence analysis for each divergent branch. More...
class	llvm::GenericUniformityAnalysisImpl< ContextT >
	Analysis that identifies uniform values in a data-parallel execution. More...
struct	llvm::GenericUniformityAnalysisImpl< ContextT >::PhiInput
	Value/block pair representing a single phi input. More...
class	llvm::DivergencePropagator< ContextT >
	Compute divergence starting with a divergent branch. More...

Namespaces
namespace	llvm
	This is an optimization pass for GlobalISel generic memory operations.

Macros
#define	DEBUG_TYPE   "uniformity"

Functions
template<typename CycleT >
static bool	llvm::insertIfNotContained (SmallVector< CycleT * > &Cycles, CycleT *Candidate)
	Add Candidate to Cycles if it is not already contained in Cycles.
template<typename CycleT , typename BlockT >
static const CycleT *	llvm::getExtDivCycle (const CycleT *Cycle, const BlockT *DivTermBlock, const BlockT *JoinBlock)
	Return the outermost cycle made divergent by branch outside it.
template<typename ContextT , typename CycleT , typename BlockT , typename DominatorTreeT >
static const CycleT *	llvm::getIntDivCycle (const CycleT *Cycle, const BlockT *DivTermBlock, const BlockT *JoinBlock, const DominatorTreeT &DT, ContextT &Context)
	Return the outermost cycle made divergent by branch inside it.
template<typename ContextT , typename CycleT , typename BlockT , typename DominatorTreeT >
static const CycleT *	llvm::getOutermostDivergentCycle (const CycleT *Cycle, const BlockT *DivTermBlock, const BlockT *JoinBlock, const DominatorTreeT &DT, ContextT &Context)

Detailed Description

Implementation of uniformity analysis.

The algorithm is a fixed point iteration that starts with the assumption that all control flow and all values are uniform. Starting from sources of divergence (whose discovery must be implemented by a CFG- or even target-specific derived class), divergence of values is propagated from definition to uses in a straight-forward way. The main complexity lies in the propagation of the impact of divergent control flow on the divergence of values (sync dependencies).

NOTE: In general, no interface exists for a transform to update (Machine)UniformityInfo. Additionally, (Machine)CycleAnalysis is a transitive dependence, but it also does not provide an interface for updating itself. Given that, transforms should not preserve uniformity in their getAnalysisUsage() callback.

Definition in file GenericUniformityImpl.h.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "uniformity"

Definition at line 57 of file GenericUniformityImpl.h.