llvm::promoteLoopAccessesToScalars

Synopsis

Declared in <llvm/Transforms/Utils/LoopUtils.h>

bool
promoteLoopAccessesToScalars(
    SmallSetVector<Value*, 8> const& PointerMustAliases,
    SmallVectorImpl<BasicBlock*>& ExitBlocks,
    SmallVectorImpl<BasicBlock::iterator>& InsertPts,
    SmallVectorImpl<MemoryAccess*>& MSSAInsertPts,
    PredIteratorCache& PIC,
    LoopInfo* LI,
    DominatorTree* DT,
    AssumptionCache* AC,
    TargetLibraryInfo const* TLI,
    TargetTransformInfo* TTI,
    Loop* CurLoop,
    MemorySSAUpdater& MSSAU,
    ICFLoopSafetyInfo* SafetyInfo,
    OptimizationRemarkEmitter* ORE,
    bool AllowSpeculation,
    bool HasReadsOutsideSet);

Description

Try to promote memory values to scalars by sinking stores out of the loop and moving loads to before the loop. We do this by looping over the stores in the loop, looking for stores to Must pointers which are loop invariant. It takes a set of must-alias values, Loop exit blocks vector, loop exit blocks insertion point vector, PredIteratorCache, LoopInfo, DominatorTree, Loop, AliasSet information for all instructions of the loop and loop safety information as arguments. Diagnostics is emitted via ORE. It returns changed status. AllowSpeculation is whether values should be hoisted even if they are not guaranteed to execute in the loop, but are safe to speculatively execute.

Return Value

True if any accesses were promoted.

Parameters

Name	Description
PointerMustAliases	Must-alias pointer set considered for promotion.
ExitBlocks	Loop exit blocks used for sunk stores.
InsertPts	Insertion points in the corresponding exit blocks.
MSSAInsertPts	MemorySSA insertion points for promoted accesses.
PIC	Predecessor-iterator cache for the transform.
LI	Loop info for the function.
DT	Dominator tree for the function.
AC	Assumption cache for the function.
TLI	Target library info.
TTI	Target transform info.
CurLoop	Loop whose accesses may be promoted.
MSSAU	MemorySSA updater for the transform.
SafetyInfo	Loop safety information for faulting ops.
ORE	Optional remark emitter for diagnostics.
AllowSpeculation	Whether to hoist values that may not always execute.
HasReadsOutsideSet	Whether the alias set has reads outside the set.