#include "llvm/Transforms/Scalar/ConstraintElimination.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstraintSystem.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/ScalarEvolutionPatternMatch.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/DebugCounter.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include <optional>
#include <string>

Macros
#define	DEBUG_TYPE "constraint-elimination"

Functions
	STATISTIC (NumCondsRemoved, "Number of instructions removed")
	DEBUG_COUNTER (EliminatedCounter, "conds-eliminated", "Controls which conditions are eliminated")
static Instruction *	getContextInstForUse (Use &U)
static Instruction *	findCommonDominatorOfUses (Instruction &I, DominatorTree &DT)
	Returns the closest program point dominating all uses of `I`.
static OffsetResult	collectOffsets (GEPOperator &GEP, const DataLayout &DL)
static Decomposition	decompose (Value *V, const ConstraintInfo &Info, bool IsSigned, const DataLayout &DL)
static bool	canUseSExt (ConstantInt *CI)
static bool	doesHoldInRange (const ConstraintInfo &Info, Value *Op, const ConstantRange &R, bool Signed)
	Returns true if `Info` implies that `Op` is in `R`, interpreting `R` as a signed range if `Signed` is set and as an unsigned range otherwise.
static bool	isKnownNoWrap (Instruction::BinaryOps Opcode, Value Op0, Value Op1, unsigned NoWrapFlags, const ConstraintInfo &Info, bool Signed)
	Returns true if `Opcode` applied to `Op0` and `Op1` with `NoWrapFlags` is known to not wrap in signed or unsigned, depending on `Signed`.
static bool	isKnownNoWrap (Value *V, const ConstraintInfo &Info, bool Signed)
	Returns true if `V` is known to not wrap in signed or unsigned, depending on `Signed`.
static Decomposition	decomposeGEP (GEPOperator &GEP, const ConstraintInfo &Info, bool IsSigned, const DataLayout &DL)
static RowTy	getRowForLessEqual (const Decomposition &ADec, const Decomposition &BDec, const DenseMap< Value , unsigned > &Value2Index, SmallVectorImpl< Value > &NewVariables)
	Build the row for 'ADec <= BDec', using the indices from `Value2Index`.
static void	dumpConstraint (ArrayRef< Entry > C, const DenseMap< Value *, unsigned > &Value2Index)
static std::pair< Value , Value >	getStartAndBackedgeValue (const PHINode &PN, const BasicBlock *LoopPred)
	Splits the induction phi `PN` into the start value, coming from the loop predecessor `LoopPred`, and the backedge value, coming from inside the loop.
template<typename PhiMatchTy>
static auto	m_IncrementOf (const PhiMatchTy &PhiM, const APInt *&Off)
	Matches an increment of `PhiM` by a constant offset, captured in `Off`.
static bool	getConstraintFromMemoryAccess (GetElementPtrInst &GEP, uint64_t AccessSize, CmpPredicate &Pred, Value &A, Value &B, const DataLayout &DL, const TargetLibraryInfo &TLI)
static bool	canStrengthenFlags (Instruction *I)
	Returns true if `I` is a candidate whose poison-generating flags may be strengthened using the constraint systems.
static bool	tryToStrengthenFlags (Instruction *I, ConstraintInfo &Info)
	Try to strengthen `I's` poison generating flags using `Info`.
static void	dumpUnpackedICmp (raw_ostream &OS, ICmpInst::Predicate Pred, Value LHS, Value RHS)
static void	generateReproducer (Instruction Cond, bool IsSigned, Module M, ArrayRef< ReproducerEntry > Stack, ConstraintInfo &Info, DominatorTree &DT)
	Helper function to generate a reproducer function for simplifying `Cond`.
static std::optional< bool >	checkCondition (CmpInst::Predicate Pred, Value A, Value B, Instruction *CheckInst, ConstraintInfo &Info)
static bool	checkAndReplaceCondition (CmpPredicate Pred, Value A, Value B, Instruction CheckInst, ConstraintInfo &Info, unsigned NumIn, unsigned NumOut, Instruction ContextInst, Module ReproducerModule, ArrayRef< ReproducerEntry > ReproducerCondStack, DominatorTree &DT, SmallVectorImpl< Instruction > &ToRemove)
static bool	checkAndReplaceMinMax (MinMaxIntrinsic MinMax, ConstraintInfo &Info, SmallVectorImpl< Instruction > &ToRemove)
static bool	checkAndReplaceCmp (CmpIntrinsic I, ConstraintInfo &Info, SmallVectorImpl< Instruction > &ToRemove)
static bool	checkAndReplaceUSubSat (SaturatingInst USub, ConstraintInfo &Info, SmallVectorImpl< Instruction > &ToRemove)
	Try to replace `USub` by a plain subtract, if `Info` proves it cannot saturate.
static void	removeEntryFromStack (const StackEntry &E, ConstraintInfo &Info, Module *ReproducerModule, SmallVectorImpl< ReproducerEntry > &ReproducerCondStack, SmallVectorImpl< StackEntry > &DFSInStack)
static bool	checkOrAndOpImpliedByOther (FactOrCheck &CB, ConstraintInfo &Info, Module ReproducerModule, SmallVectorImpl< ReproducerEntry > &ReproducerCondStack, SmallVectorImpl< StackEntry > &DFSInStack, SmallVectorImpl< Instruction > &ToRemove)
	Check if either the first condition of an AND or OR is implied by the (negated in case of OR) second condition or vice versa.
static bool	replaceOverflowUses (WithOverflowInst II, SmallVectorImpl< Instruction > &ToRemove)
	Replace the uses of `II`, which is known not to overflow, by the corresponding plain binary operation and a false overflow flag.
static bool	tryToSimplifyOverflowMath (WithOverflowInst II, ConstraintInfo &Info, SmallVectorImpl< Instruction > &ToRemove)
static bool	eliminateConstraints (Function &F, DominatorTree &DT, LoopInfo &LI, ScalarEvolution &SE, OptimizationRemarkEmitter &ORE, TargetLibraryInfo &TLI)

Variables
static cl::opt< unsigned >	MaxRows ("constraint-elimination-max-rows", cl::init(500), cl::Hidden, cl::desc("Maximum number of rows to keep in constraint system"))
static cl::opt< bool >	DumpReproducers ("constraint-elimination-dump-reproducers", cl::init(false), cl::Hidden, cl::desc("Dump IR to reproduce successful transformations."))
static int64_t	MaxConstraintValue = std::numeric_limits<int64_t>::max()
static int64_t	MinSignedConstraintValue = std::numeric_limits<int64_t>::min()

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "constraint-elimination"

Definition at line 54 of file ConstraintElimination.cpp.

Function Documentation

◆ canStrengthenFlags()

bool canStrengthenFlags ( Instruction * I )

static

Returns true if I is a candidate whose poison-generating flags may be strengthened using the constraint systems.

Definition at line 1393 of file ConstraintElimination.cpp.

References llvm::dyn_cast(), I, and llvm::isa().

Referenced by tryToStrengthenFlags().

◆ canUseSExt()

bool canUseSExt ( ConstantInt * CI )

static

Definition at line 497 of file ConstraintElimination.cpp.

References llvm::ConstantInt::getValue(), MaxConstraintValue, MinSignedConstraintValue, llvm::APInt::sgt(), and llvm::APInt::slt().

Referenced by decompose().

◆ checkAndReplaceCmp()

bool checkAndReplaceCmp	(	CmpIntrinsic *	I,
		ConstraintInfo &	Info,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Definition at line 1950 of file ConstraintElimination.cpp.

References checkCondition(), llvm::ConstantInt::getSigned(), I, llvm::CmpInst::ICMP_EQ, LHS, RHS, and ToRemove.

◆ checkAndReplaceCondition()

bool checkAndReplaceCondition	(	CmpPredicate	Pred,
		Value *	A,
		Value *	B,
		Instruction *	CheckInst,
		ConstraintInfo &	Info,
		unsigned	NumIn,
		unsigned	NumOut,
		Instruction *	ContextInst,
		Module *	ReproducerModule,
		ArrayRef< ReproducerEntry >	ReproducerCondStack,
		DominatorTree &	DT,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

◆ checkAndReplaceMinMax()

bool checkAndReplaceMinMax	(	MinMaxIntrinsic *	MinMax,
		ConstraintInfo &	Info,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Definition at line 1930 of file ConstraintElimination.cpp.

References checkCondition(), llvm::CmpInst::getNonStrictPredicate(), and ToRemove.

◆ checkAndReplaceUSubSat()

bool checkAndReplaceUSubSat	(	SaturatingInst *	USub,
		ConstraintInfo &	Info,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Try to replace USub by a plain subtract, if Info proves it cannot saturate.

Returns true if USub was replaced.

Definition at line 1974 of file ConstraintElimination.cpp.

References A(), B(), checkCondition(), llvm::BinaryOpIntrinsic::getLHS(), llvm::BinaryOpIntrinsic::getRHS(), llvm::CmpInst::ICMP_UGE, llvm::Value::replaceAllUsesWith(), llvm::Sub, and ToRemove.

◆ checkCondition()

std::optional< bool > checkCondition	(	CmpInst::Predicate	Pred,
		Value *	A,
		Value *	B,
		Instruction *	CheckInst,
		ConstraintInfo &	Info )

static

Definition at line 1804 of file ConstraintElimination.cpp.

References A(), B(), llvm::dbgs(), dumpUnpackedICmp(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::CmpInst::getInversePredicate(), llvm::ICmpInst::getSignedPredicate(), llvm::CmpInst::isEquality(), llvm::CmpInst::isUnsigned(), LLVM_DEBUG, and llvm::DebugCounter::shouldExecute().

Referenced by checkAndReplaceCmp(), checkAndReplaceCondition(), checkAndReplaceMinMax(), checkAndReplaceUSubSat(), and checkOrAndOpImpliedByOther().

◆ checkOrAndOpImpliedByOther()

bool checkOrAndOpImpliedByOther	(	FactOrCheck &	CB,
		ConstraintInfo &	Info,
		Module *	ReproducerModule,
		SmallVectorImpl< ReproducerEntry > &	ReproducerCondStack,
		SmallVectorImpl< StackEntry > &	DFSInStack,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Check if either the first condition of an AND or OR is implied by the (negated in case of OR) second condition or vice versa.

Definition at line 2009 of file ConstraintElimination.cpp.

References A(), assert(), B(), llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::cast(), checkCondition(), E(), llvm::ConstantInt::getBool(), llvm::CmpInst::getInversePredicate(), llvm::User::getOperand(), llvm::Value::getType(), llvm::isa(), LHS, llvm::PatternMatch::m_ICmpLike(), llvm::PatternMatch::m_LogicalAnd(), llvm::PatternMatch::m_LogicalOr(), llvm::PatternMatch::m_Value(), llvm::SCEVPatternMatch::match(), removeEntryFromStack(), llvm::Value::replaceAllUsesWith(), RHS, llvm::SmallVectorTemplateCommon< T, typename >::size(), ToRemove, and llvm::Value::use_empty().

◆ collectOffsets()

OffsetResult collectOffsets	(	GEPOperator &	GEP,
		const DataLayout &	DL )

static

Definition at line 464 of file ConstraintElimination.cpp.

References llvm::BitWidth, DL, llvm::dyn_cast(), GEP, and llvm::MapVector< KeyT, ValueT, MapType, VectorType, N >::size().

Referenced by decomposeGEP(), and getConstraintFromMemoryAccess().

◆ DEBUG_COUNTER()

DEBUG_COUNTER	(	EliminatedCounter	,
		"conds-eliminated"	,
		"Controls which conditions are eliminated"	)

◆ decompose()

Decomposition decompose	(	Value *	V,
		const ConstraintInfo &	Info,
		bool	IsSigned,
		const DataLayout &	DL )

static

◆ decomposeGEP()

Decomposition decomposeGEP	(	GEPOperator &	GEP,
		const ConstraintInfo &	Info,
		bool	IsSigned,
		const DataLayout &	DL )

static

Definition at line 602 of file ConstraintElimination.cpp.

References assert(), collectOffsets(), decompose(), DL, GEP, and llvm::GEPNoWrapFlags::none().

Referenced by decompose().

◆ doesHoldInRange()

bool doesHoldInRange	(	const ConstraintInfo &	Info,
		Value *	Op,
		const ConstantRange &	R,
		bool	Signed )

static

Returns true if Info implies that Op is in R, interpreting R as a signed range if Signed is set and as an unsigned range otherwise.

Definition at line 504 of file ConstraintElimination.cpp.

References llvm::BitWidth, llvm::APInt::getMaxValue(), llvm::APInt::getMinValue(), llvm::APInt::getSignedMaxValue(), llvm::APInt::getSignedMinValue(), llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULE, MaxConstraintValue, and Signed.

Referenced by isKnownNoWrap().

◆ dumpConstraint()

void dumpConstraint	(	ArrayRef< Entry >	C,
		const DenseMap< Value *, unsigned > &	Value2Index )

static

Definition at line 1031 of file ConstraintElimination.cpp.

References llvm::ConstraintSystem::addRow(), C(), llvm::ConstraintSystem::dump(), and llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::size().

◆ dumpUnpackedICmp()

void dumpUnpackedICmp	(	raw_ostream &	OS,
		ICmpInst::Predicate	Pred,
		Value *	LHS,
		Value *	RHS )

static

Definition at line 1645 of file ConstraintElimination.cpp.

References LHS, and RHS.

Referenced by checkCondition(), and generateReproducer().

◆ eliminateConstraints()

bool eliminateConstraints	(	Function &	F,
		DominatorTree &	DT,
		LoopInfo &	LI,
		ScalarEvolution &	SE,
		OptimizationRemarkEmitter &	ORE,
		TargetLibraryInfo &	TLI )

static

Definition at line 2237 of file ConstraintElimination.cpp.

References A(), B(), Changed, DumpReproducers, F, llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), if(), llvm::make_pointer_range(), Module, llvm::stable_sort(), and llvm::DominatorTreeBase< NodeT, IsPostDom >::updateDFSNumbers().

Referenced by llvm::ConstraintEliminationPass::run().

◆ findCommonDominatorOfUses()

Instruction * findCommonDominatorOfUses	(	Instruction &	I,
		DominatorTree &	DT )

static

Returns the closest program point dominating all uses of I.

Definition at line 79 of file ConstraintElimination.cpp.

References llvm::DominatorTree::findNearestCommonDominator(), getContextInstForUse(), llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent(), and I.

◆ generateReproducer()

void generateReproducer	(	Instruction *	Cond,
		bool	IsSigned,
		Module *	M,
		ArrayRef< ReproducerEntry >	Stack,
		ConstraintInfo &	Info,
		DominatorTree &	DT )

static

Helper function to generate a reproducer function for simplifying Cond.

The reproducer function contains a series of @llvm.assume calls, one for each condition in Stack. For each condition, the operand instruction are cloned until we reach operands that have an entry in Value2Index. Those will then be added as function arguments. DT is used to order cloned instructions. The reproducer function will get added to M, if it is non-null. Otherwise no reproducer function is generated.

Definition at line 1676 of file ConstraintElimination.cpp.

References A(), AbstractManglingParser< Derived, Alloc >::Ops, llvm::append_range(), assert(), B(), llvm::CmpInst::BAD_ICMP_PREDICATE, Cond, llvm::BasicBlock::Create(), llvm::Function::Create(), llvm::dbgs(), llvm::DominatorTree::dominates(), llvm::Instruction::dropUnknownNonDebugMetadata(), dumpUnpackedICmp(), llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::ValueMap< KeyT, ValueT, Config >::end(), llvm::GlobalValue::ExternalLinkage, F, llvm::ValueMap< KeyT, ValueT, Config >::find(), llvm::FunctionType::get(), getName(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::Instruction::insertBefore(), llvm::isa(), llvm::CmpInst::isSigned(), LLVM_DEBUG, P, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::remapInstructionsInBlocks(), llvm::Instruction::setDebugLoc(), llvm::sort(), and llvm::verifyFunction().

Referenced by checkAndReplaceCondition().

◆ getConstraintFromMemoryAccess()

bool getConstraintFromMemoryAccess	(	GetElementPtrInst &	GEP,
		uint64_t	AccessSize,
		CmpPredicate &	Pred,
		Value *&	A,
		Value *&	B,
		const DataLayout &	DL,
		const TargetLibraryInfo &	TLI )

static

Definition at line 1348 of file ConstraintElimination.cpp.

References A(), B(), llvm::BitWidth, llvm::cast(), collectOffsets(), DL, GEP, llvm::getBaseObjectSize(), llvm::CmpInst::ICMP_ULE, llvm::ObjectSizeOpts::NullIsUnknownSize, llvm::Offset, llvm::ObjectSizeOpts::RoundToAlign, Size, and uint64_t.

◆ getContextInstForUse()

Instruction * getContextInstForUse ( Use & U )

static

Definition at line 71 of file ConstraintElimination.cpp.

References llvm::cast(), and llvm::dyn_cast().

Referenced by checkAndReplaceCondition(), and findCommonDominatorOfUses().

◆ getRowForLessEqual()

RowTy getRowForLessEqual	(	const Decomposition &	ADec,
		const Decomposition &	BDec,
		const DenseMap< Value *, unsigned > &	Value2Index,
		SmallVectorImpl< Value * > &	NewVariables )

static

Build the row for 'ADec <= BDec', using the indices from Value2Index.

Variables not in Value2Index are appended to NewVariables and get the indices following the ones in Value2Index. Returns an empty row if the coefficients overflow.

Definition at line 774 of file ConstraintElimination.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::drop_begin(), E(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::erase_if(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::find(), llvm::find_if(), I, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::size(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and llvm::SubOverflow().

◆ getStartAndBackedgeValue()

std::pair< Value , Value > getStartAndBackedgeValue	(	const PHINode &	PN,
		const BasicBlock *	LoopPred )

static

Splits the induction phi PN into the start value, coming from the loop predecessor LoopPred, and the backedge value, coming from inside the loop.

Returns {nullptr, nullptr} if PN has other incoming values.

Definition at line 1043 of file ConstraintElimination.cpp.

References assert(), llvm::PHINode::getBasicBlockIndex(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), and llvm::PHINode::getNumIncomingValues().

◆ isKnownNoWrap() [1/2]

bool isKnownNoWrap	(	Instruction::BinaryOps	Opcode,
		Value *	Op0,
		Value *	Op1,
		unsigned	NoWrapFlags,
		const ConstraintInfo &	Info,
		bool	Signed )

static

Returns true if Opcode applied to Op0 and Op1 with NoWrapFlags is known to not wrap in signed or unsigned, depending on Signed.

Definition at line 537 of file ConstraintElimination.cpp.

References C(), doesHoldInRange(), llvm::dyn_cast(), llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_UGE, llvm::ConstantRange::makeExactNoWrapRegion(), and Signed.

Referenced by decompose(), isKnownNoWrap(), tryToSimplifyOverflowMath(), and tryToStrengthenFlags().

◆ isKnownNoWrap() [2/2]

bool isKnownNoWrap	(	Value *	V,
		const ConstraintInfo &	Info,
		bool	Signed )

static

Returns true if V is known to not wrap in signed or unsigned, depending on Signed.

Definition at line 576 of file ConstraintElimination.cpp.

References llvm::dyn_cast(), isKnownNoWrap(), llvm::PatternMatch::m_DisjointOr(), llvm::PatternMatch::m_Value(), llvm::SCEVPatternMatch::match(), and Signed.

◆ m_IncrementOf()

template<typename PhiMatchTy>

auto m_IncrementOf	(	const PhiMatchTy &	PhiM,
		const APInt *&	Off )

static

Matches an increment of PhiM by a constant offset, captured in Off.

The increment must be a plain IR add or [u|s]add.with.overflow.

Definition at line 1055 of file ConstraintElimination.cpp.

References llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_c_Intrinsic(), llvm::PatternMatchHelpers::m_CombineOr(), and llvm::PatternMatch::m_ExtractValue().

◆ removeEntryFromStack()

void removeEntryFromStack	(	const StackEntry &	E,
		ConstraintInfo &	Info,
		Module *	ReproducerModule,
		SmallVectorImpl< ReproducerEntry > &	ReproducerCondStack,
		SmallVectorImpl< StackEntry > &	DFSInStack )

static

Definition at line 1992 of file ConstraintElimination.cpp.

References E(), and llvm::SmallVectorTemplateBase< T, bool >::pop_back().

Referenced by checkOrAndOpImpliedByOther().

◆ replaceOverflowUses()

bool replaceOverflowUses	(	WithOverflowInst *	II,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Replace the uses of II, which is known not to overflow, by the corresponding plain binary operation and a false overflow flag.

Definition at line 2191 of file ConstraintElimination.cpp.

References llvm::cast(), Changed, llvm::PoisonValue::get(), I, II, llvm::PatternMatch::m_ExtractValue(), llvm::PatternMatch::m_Value(), llvm::make_early_inc_range(), llvm::SCEVPatternMatch::match(), llvm::Value::replaceAllUsesWith(), and ToRemove.

Referenced by tryToSimplifyOverflowMath().

◆ STATISTIC()

STATISTIC	(	NumCondsRemoved	,
		"Number of instructions removed"	)

◆ tryToSimplifyOverflowMath()

bool tryToSimplifyOverflowMath	(	WithOverflowInst *	II,
		ConstraintInfo &	Info,
		SmallVectorImpl< Instruction * > &	ToRemove )

static

Definition at line 2230 of file ConstraintElimination.cpp.

References II, isKnownNoWrap(), replaceOverflowUses(), and ToRemove.

◆ tryToStrengthenFlags()

bool tryToStrengthenFlags	(	Instruction *	I,
		ConstraintInfo &	Info )

static

Try to strengthen I's poison generating flags using Info.

Returns true if I was modified.

Definition at line 1425 of file ConstraintElimination.cpp.

References assert(), canStrengthenFlags(), Changed, llvm::dbgs(), I, isKnownNoWrap(), and LLVM_DEBUG.

Variable Documentation

◆ DumpReproducers

cl::opt< bool > DumpReproducers("constraint-elimination-dump-reproducers", cl::init(false), cl::Hidden, cl::desc("Dump IR to reproduce successful transformations."))	(	"constraint-elimination-dump-reproducers"	,
		cl::init(false)	,
		cl::Hidden	,
		cl::desc("Dump IR to reproduce successful transformations.")	)

static

Referenced by eliminateConstraints().

◆ MaxConstraintValue

int64_t MaxConstraintValue = std::numeric_limits<int64_t>::max()

static

Definition at line 68 of file ConstraintElimination.cpp.

Referenced by canUseSExt(), decompose(), and doesHoldInRange().

◆ MaxRows

cl::opt< unsigned > MaxRows("constraint-elimination-max-rows", cl::init(500), cl::Hidden, cl::desc("Maximum number of rows to keep in constraint system"))	(	"constraint-elimination-max-rows"	,
		cl::init(500)	,
		cl::Hidden	,
		cl::desc("Maximum number of rows to keep in constraint system")	)

static

◆ MinSignedConstraintValue

int64_t MinSignedConstraintValue = std::numeric_limits<int64_t>::min()

static

Definition at line 69 of file ConstraintElimination.cpp.

Referenced by canUseSExt().

Macros

Functions

Variables

Macro Definition Documentation

◆ DEBUG_TYPE

Function Documentation

◆ canStrengthenFlags()

◆ canUseSExt()

◆ checkAndReplaceCmp()

◆ checkAndReplaceCondition()

◆ checkAndReplaceMinMax()

◆ checkAndReplaceUSubSat()

◆ checkCondition()

◆ checkOrAndOpImpliedByOther()

◆ collectOffsets()

◆ DEBUG_COUNTER()

◆ decompose()

◆ decomposeGEP()

◆ doesHoldInRange()

◆ dumpConstraint()

◆ dumpUnpackedICmp()

◆ eliminateConstraints()

◆ findCommonDominatorOfUses()

◆ generateReproducer()

◆ getConstraintFromMemoryAccess()

◆ getContextInstForUse()

◆ getRowForLessEqual()

◆ getStartAndBackedgeValue()

◆ isKnownNoWrap() [1/2]

◆ isKnownNoWrap() [2/2]

◆ m_IncrementOf()

◆ removeEntryFromStack()

◆ replaceOverflowUses()

◆ STATISTIC()

◆ tryToSimplifyOverflowMath()

◆ tryToStrengthenFlags()

Variable Documentation

◆ DumpReproducers

◆ MaxConstraintValue

◆ MaxRows

◆ MinSignedConstraintValue