LLVM: llvm::TargetTransformInfo::UnrollingPreferences Struct Reference (original) (raw)

Parameters that control the generic loop unrolling transformation. More...

#include "[llvm/Analysis/TargetTransformInfo.h](TargetTransformInfo%5F8h%5Fsource.html)"

Public Attributes
unsigned	Threshold
	The cost threshold for the unrolled loop.
unsigned	MaxPercentThresholdBoost
	If complete unrolling will reduce the cost of the loop, we will boost the Threshold by a certain percent to allow more aggressive complete unrolling.
unsigned	OptSizeThreshold
	The cost threshold for the unrolled loop when optimizing for size (set to UINT_MAX to disable).
unsigned	PartialThreshold
	The cost threshold for the unrolled loop, like Threshold, but used for partial/runtime unrolling (set to UINT_MAX to disable).
unsigned	PartialOptSizeThreshold
	The cost threshold for the unrolled loop when optimizing for size, like OptSizeThreshold, but used for partial/runtime unrolling (set to UINT_MAX to disable).
unsigned	Count
	A forced unrolling factor (the number of concatenated bodies of the original loop in the unrolled loop body).
unsigned	DefaultUnrollRuntimeCount
	Default unroll count for loops with run-time trip count.
unsigned	MaxCount
unsigned	MaxUpperBound
	Set the maximum upper bound of trip count.
unsigned	FullUnrollMaxCount
	Set the maximum unrolling factor for full unrolling.
unsigned	BEInsns
bool	Partial
	Allow partial unrolling (unrolling of loops to expand the size of the loop body, not only to eliminate small constant-trip-count loops).
bool	Runtime
	Allow runtime unrolling (unrolling of loops to expand the size of the loop body even when the number of loop iterations is not known at compile time).
bool	AllowRemainder
	Allow generation of a loop remainder (extra iterations after unroll).
bool	AllowExpensiveTripCount
	Allow emitting expensive instructions (such as divisions) when computing the trip count of a loop for runtime unrolling.
bool	Force
	Apply loop unroll on any kind of loop (mainly to loops that fail runtime unrolling).
bool	UpperBound
	Allow using trip count upper bound to unroll loops.
bool	UnrollRemainder
	Allow unrolling of all the iterations of the runtime loop remainder.
bool	UnrollAndJam
	Allow unroll and jam. Used to enable unroll and jam for the target.
unsigned	UnrollAndJamInnerLoopThreshold
	Threshold for unroll and jam, for inner loop size.
unsigned	MaxIterationsCountToAnalyze
	Don't allow loop unrolling to simulate more than this number of iterations when checking full unroll profitability.
bool	UnrollVectorizedLoop = false
	Don't disable runtime unroll for the loops which were vectorized.
unsigned	SCEVExpansionBudget
	Don't allow runtime unrolling if expanding the trip count takes more than SCEVExpansionBudget.
bool	RuntimeUnrollMultiExit
	Allow runtime unrolling multi-exit loops.
bool	AddAdditionalAccumulators
	Allow unrolling to add parallel reduction phis.

Parameters that control the generic loop unrolling transformation.

Definition at line 608 of file TargetTransformInfo.h.

◆ AddAdditionalAccumulators

bool llvm::TargetTransformInfo::UnrollingPreferences::AddAdditionalAccumulators

◆ AllowExpensiveTripCount

bool llvm::TargetTransformInfo::UnrollingPreferences::AllowExpensiveTripCount

◆ AllowRemainder

bool llvm::TargetTransformInfo::UnrollingPreferences::AllowRemainder

◆ BEInsns

unsigned llvm::TargetTransformInfo::UnrollingPreferences::BEInsns

◆ Count

unsigned llvm::TargetTransformInfo::UnrollingPreferences::Count

◆ DefaultUnrollRuntimeCount

unsigned llvm::TargetTransformInfo::UnrollingPreferences::DefaultUnrollRuntimeCount

◆ Force

bool llvm::TargetTransformInfo::UnrollingPreferences::Force

◆ FullUnrollMaxCount

unsigned llvm::TargetTransformInfo::UnrollingPreferences::FullUnrollMaxCount

◆ MaxCount

unsigned llvm::TargetTransformInfo::UnrollingPreferences::MaxCount

◆ MaxIterationsCountToAnalyze

unsigned llvm::TargetTransformInfo::UnrollingPreferences::MaxIterationsCountToAnalyze

◆ MaxPercentThresholdBoost

unsigned llvm::TargetTransformInfo::UnrollingPreferences::MaxPercentThresholdBoost

If complete unrolling will reduce the cost of the loop, we will boost the Threshold by a certain percent to allow more aggressive complete unrolling.

This value provides the maximum boost percentage that we can apply to Threshold (The value should be no less than 100). BoostedThreshold = Threshold * min(RolledCost / UnrolledCost, MaxPercentThresholdBoost / 100) E.g. if complete unrolling reduces the loop execution time by 50% then we boost the threshold by the factor of 2x. If unrolling is not expected to reduce the running time, then we do not increase the threshold.

Definition at line 627 of file TargetTransformInfo.h.

Referenced by llvm::gatherUnrollingPreferences(), and shouldFullUnroll().

◆ MaxUpperBound

unsigned llvm::TargetTransformInfo::UnrollingPreferences::MaxUpperBound

◆ OptSizeThreshold

unsigned llvm::TargetTransformInfo::UnrollingPreferences::OptSizeThreshold

◆ Partial

bool llvm::TargetTransformInfo::UnrollingPreferences::Partial

Allow partial unrolling (unrolling of loops to expand the size of the loop body, not only to eliminate small constant-trip-count loops).

Definition at line 665 of file TargetTransformInfo.h.

◆ PartialOptSizeThreshold

unsigned llvm::TargetTransformInfo::UnrollingPreferences::PartialOptSizeThreshold

◆ PartialThreshold

unsigned llvm::TargetTransformInfo::UnrollingPreferences::PartialThreshold

The cost threshold for the unrolled loop, like Threshold, but used for partial/runtime unrolling (set to UINT_MAX to disable).

Definition at line 633 of file TargetTransformInfo.h.

Referenced by computeHeuristicUnrollFactor(), llvm::computeUnrollCount(), llvm::gatherUnrollingPreferences(), llvm::AArch64TTIImpl::getUnrollingPreferences(), llvm::AMDGPUTTIImpl::getUnrollingPreferences(), llvm::BasicTTIImplBase< BasicTTIImpl >::getUnrollingPreferences(), llvm::NVPTXTTIImpl::getUnrollingPreferences(), llvm::SystemZTTIImpl::getUnrollingPreferences(), llvm::WebAssemblyTTIImpl::getUnrollingPreferences(), shouldPartialUnroll(), and tryToUnrollLoop().

◆ Runtime

bool llvm::TargetTransformInfo::UnrollingPreferences::Runtime

Allow runtime unrolling (unrolling of loops to expand the size of the loop body even when the number of loop iterations is not known at compile time).

Definition at line 669 of file TargetTransformInfo.h.

◆ RuntimeUnrollMultiExit

bool llvm::TargetTransformInfo::UnrollingPreferences::RuntimeUnrollMultiExit

◆ SCEVExpansionBudget

unsigned llvm::TargetTransformInfo::UnrollingPreferences::SCEVExpansionBudget

◆ Threshold

unsigned llvm::TargetTransformInfo::UnrollingPreferences::Threshold

The cost threshold for the unrolled loop.

Should be relative to the getInstructionCost values returned by this API, and the expectation is that the unrolled loop's instructions when run through that interface should not exceed this cost. However, this is only an estimate. Also, specific loops may be unrolled even with a cost above this threshold if deemed profitable. Set this to UINT_MAX to disable the loop body cost restriction.

Definition at line 616 of file TargetTransformInfo.h.

Referenced by computeHeuristicUnrollFactor(), computeUnrollAndJamCount(), llvm::computeUnrollCount(), llvm::gatherUnrollingPreferences(), llvm::AMDGPUTTIImpl::getUnrollingPreferences(), llvm::NVPTXTTIImpl::getUnrollingPreferences(), shouldFullUnroll(), shouldPragmaUnroll(), and tryToUnrollLoop().

◆ UnrollAndJam

bool llvm::TargetTransformInfo::UnrollingPreferences::UnrollAndJam

◆ UnrollAndJamInnerLoopThreshold

unsigned llvm::TargetTransformInfo::UnrollingPreferences::UnrollAndJamInnerLoopThreshold

◆ UnrollRemainder

bool llvm::TargetTransformInfo::UnrollingPreferences::UnrollRemainder

◆ UnrollVectorizedLoop

bool llvm::TargetTransformInfo::UnrollingPreferences::UnrollVectorizedLoop = false

◆ UpperBound

bool llvm::TargetTransformInfo::UnrollingPreferences::UpperBound

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

include/llvm/Analysis/TargetTransformInfo.h