Loads.cpp File Reference

#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumeBundleQueries.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Operator.h"

Go to the source code of this file.

Functions
static bool	isAligned (const Value *Base, Align Alignment, const DataLayout &DL)
static bool	isDereferenceableAndAlignedPointer (const Value *V, Align Alignment, const APInt &Size, const DataLayout &DL, const Instruction *CtxI, AssumptionCache *AC, const DominatorTree *DT, const TargetLibraryInfo *TLI, SmallPtrSetImpl< const Value * > &Visited, unsigned MaxDepth)
	Test if V is always a pointer to allocated and suitably aligned memory for a simple load or store.
static bool	AreEquivalentAddressValues (const Value *A, const Value *B)
	Test if A and B will obviously have the same value.
static bool	suppressSpeculativeLoadForSanitizers (const Instruction &CtxI)
static bool	areNonOverlapSameBaseLoadAndStore (const Value *LoadPtr, Type *LoadTy, const Value *StorePtr, Type *StoreTy, const DataLayout &DL)
static Value *	getAvailableLoadStore (Instruction *Inst, const Value *Ptr, Type *AccessTy, bool AtLeastAtomic, const DataLayout &DL, bool *IsLoadCSE)
static bool	isPointerUseReplacable (const Use &U)
static bool	isPointerAlwaysReplaceable (const Value *From, const Value *To, const DataLayout &DL)

Function Documentation

AreEquivalentAddressValues()

static bool AreEquivalentAddressValues ( const Value *  A, const Value *  B  )

static

Test if A and B will obviously have the same value.

This includes recognizing that t0 and t1 will have the same value in code like this:

%t0 = getelementptr \@a, 0, 3
store i32 0, i32* %t0
%t1 = getelementptr \@a, 0, 3
%t2 = load i32* %t1

Definition at line 255 of file Loads.cpp.

References A, and B.

Referenced by getAvailableLoadStore(), and llvm::isSafeToLoadUnconditionally().

areNonOverlapSameBaseLoadAndStore()

static bool areNonOverlapSameBaseLoadAndStore ( const Value *  LoadPtr, Type *  LoadTy, const Value *  StorePtr, Type *  StoreTy, const DataLayout &  DL  )

static

Definition at line 508 of file Loads.cpp.

References DL, llvm::Value::getType(), llvm::ConstantRange::intersectWith(), llvm::ConstantRange::isEmptySet(), llvm::LocationSize::precise(), and llvm::Value::stripAndAccumulateConstantOffsets().

Referenced by llvm::findAvailablePtrLoadStore().

getAvailableLoadStore()

static Value * getAvailableLoadStore ( Instruction *  Inst, const Value *  Ptr, Type *  AccessTy, bool  AtLeastAtomic, const DataLayout &  DL, bool *  IsLoadCSE  )

static

Definition at line 530 of file Loads.cpp.

References AreEquivalentAddressValues(), llvm::CallingConv::C, llvm::ConstantFoldLoadFromConst(), DL, llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getFixedValue(), llvm::APInt::getSplat(), llvm::Value::getType(), llvm::CastInst::isBitOrNoopPointerCastable(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isScalable(), Ptr, llvm::Splat, and llvm::Value::stripPointerCasts().

Referenced by llvm::FindAvailableLoadedValue(), and llvm::findAvailablePtrLoadStore().

isAligned()

static bool isAligned ( const Value *  Base, Align  Alignment, const DataLayout &  DL  )

static

Definition at line 28 of file Loads.cpp.

References llvm::sampleprof::Base, and DL.

Referenced by isDereferenceableAndAlignedPointer().

isDereferenceableAndAlignedPointer()

static bool isDereferenceableAndAlignedPointer ( const Value *  V, Align  Alignment, const APInt &  Size, const DataLayout &  DL, const Instruction *  CtxI, AssumptionCache *  AC, const DominatorTree *  DT, const TargetLibraryInfo *  TLI, SmallPtrSetImpl< const Value * > &  Visited, unsigned  MaxDepth  )

static

Test if V is always a pointer to allocated and suitably aligned memory for a simple load or store.

TODO refactor this function to be able to search independently for Dereferencability and Alignment requirements.

Look through assumes to see if both dereferencability and alignment can be proven by an assume if needed.

Definition at line 35 of file Loads.cpp.

References llvm::RetainedKnowledge::ArgValue, assert(), llvm::sampleprof::Base, DL, GEP, llvm::getArgumentAliasingToReturnedPointer(), llvm::APInt::getBoolValue(), llvm::getKnowledgeForValue(), llvm::getObjectSize(), I, if(), llvm::SmallPtrSetImpl< PtrType >::insert(), isAligned(), isDereferenceableAndAlignedPointer(), llvm::isKnownNonZero(), llvm::isValidAssumeForContext(), MaxDepth, llvm::ObjectSizeOpts::NullIsUnknownSize, llvm::Offset, llvm::ObjectSizeOpts::RoundToAlign, Size, llvm::APInt::uge(), and llvm::Align::value().

Referenced by llvm::isDereferenceableAndAlignedInLoop(), isDereferenceableAndAlignedPointer(), llvm::isDereferenceableAndAlignedPointer(), llvm::isDereferenceablePointer(), and llvm::isSafeToLoadUnconditionally().

isPointerAlwaysReplaceable()

static bool isPointerAlwaysReplaceable ( const Value *  From, const Value *  To, const DataLayout &  DL  )

static

Definition at line 773 of file Loads.cpp.

References DL, From, llvm::Value::getContext(), llvm::Type::getInt8Ty(), llvm::getUnderlyingObjectAggressive(), and llvm::isDereferenceablePointer().

Referenced by llvm::canReplacePointersIfEqual(), and llvm::canReplacePointersInUseIfEqual().

isPointerUseReplacable()

static bool isPointerUseReplacable ( const Use &  U )

static

Definition at line 751 of file Loads.cpp.

References llvm::SmallVectorImpl< T >::insert(), llvm::Value::user_begin(), and llvm::Value::user_end().

Referenced by llvm::canReplacePointersInUseIfEqual().

suppressSpeculativeLoadForSanitizers()

static bool suppressSpeculativeLoadForSanitizers ( const Instruction &  CtxI )

static

Definition at line 360 of file Loads.cpp.

References F, and llvm::Instruction::getFunction().

Referenced by llvm::isSafeToLoadUnconditionally(), and llvm::mustSuppressSpeculation().