LazyValueInfo.cpp File Reference

#include "llvm/Analysis/LazyValueInfo.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueLattice.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/AssemblyAnnotationWriter.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/raw_ostream.h"
#include <optional>

Go to the source code of this file.

Classes
class	llvm::LazyValueInfoImpl

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

Macros
#define	DEBUG_TYPE   "lazy-value-info"

Functions
	INITIALIZE_PASS_BEGIN (LazyValueInfoWrapperPass, "lazy-value-info", "Lazy Value Information Analysis", false, true) INITIALIZE_PASS_END(LazyValueInfoWrapperPass
FunctionPass *	llvm::createLazyValueInfoPass ()
	createLazyValueInfoPass - This creates an instance of the LazyValueInfo pass.
static bool	hasSingleValue (const ValueLatticeElement &Val)
	Returns true if this lattice value represents at most one possible value.
static ValueLatticeElement	intersect (const ValueLatticeElement &A, const ValueLatticeElement &B)
	Combine two sets of facts about the same value into a single set of facts.
static ValueLatticeElement	getFromRangeMetadata (Instruction *BBI)
static void	AddNonNullPointer (Value *Ptr, NonNullPointerSet &PtrSet)
static void	AddNonNullPointersByInstruction (Instruction *I, NonNullPointerSet &PtrSet)
static bool	matchICmpOperand (APInt &Offset, Value *LHS, Value *Val, ICmpInst::Predicate Pred)
static std::optional< ConstantRange >	getRangeViaSLT (CmpInst::Predicate Pred, APInt RHS, function_ref< std::optional< ConstantRange >(const APInt &)> Fn)
static ValueLatticeElement	getValueFromOverflowCondition (Value *Val, WithOverflowInst *WO, bool IsTrueDest)
static bool	usesOperand (User *Usr, Value *Op)
static bool	isOperationFoldable (User *Usr)
static ValueLatticeElement	constantFoldUser (User *Usr, Value *Op, const APInt &OpConstVal, const DataLayout &DL)
static bool	isKnownNonConstant (Value *V)
	Returns true if we can statically tell that this value will never be a "useful" constant.
static Constant *	getPredicateResult (CmpInst::Predicate Pred, Constant *C, const ValueLatticeElement &Val, const DataLayout &DL)

Variables
static const unsigned	MaxProcessedPerValue = 500
lazy value	info
lazy value Lazy Value Information	Analysis
lazy value Lazy Value Information	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "lazy-value-info"

Definition at line 47 of file LazyValueInfo.cpp.

Function Documentation

AddNonNullPointer()

static void AddNonNullPointer ( Value *  Ptr, NonNullPointerSet &  PtrSet  )

static

Definition at line 676 of file LazyValueInfo.cpp.

References llvm::getUnderlyingObject(), and Ptr.

Referenced by AddNonNullPointersByInstruction().

AddNonNullPointersByInstruction()

static void AddNonNullPointersByInstruction ( Instruction *  I, NonNullPointerSet &  PtrSet  )

static

Definition at line 682 of file LazyValueInfo.cpp.

References AddNonNullPointer(), I, and MI.

constantFoldUser()

static ValueLatticeElement constantFoldUser ( User *  Usr, Value *  Op, const APInt &  OpConstVal, const DataLayout &  DL  )

static

Definition at line 1333 of file LazyValueInfo.cpp.

References assert(), llvm::CallingConv::C, DL, llvm::CastInst::getDestTy(), llvm::Constant::getIntegerValue(), llvm::BinaryOperator::getOpcode(), llvm::CastInst::getOpcode(), llvm::User::getOperand(), llvm::ValueLatticeElement::getOverdefined(), llvm::ValueLatticeElement::getRange(), isOperationFoldable(), LHS, RHS, llvm::simplifyBinOp(), and llvm::simplifyCastInst().

getFromRangeMetadata()

static ValueLatticeElement getFromRangeMetadata ( Instruction *  BBI )

static

Definition at line 592 of file LazyValueInfo.cpp.

References llvm::getConstantRangeFromMetadata(), llvm::Instruction::getMetadata(), llvm::Instruction::getOpcode(), llvm::ValueLatticeElement::getOverdefined(), llvm::ValueLatticeElement::getRange(), getRange(), llvm::Value::getType(), and Range.

Referenced by llvm::LazyValueInfoImpl::getValueAt().

getPredicateResult()

static Constant * getPredicateResult ( CmpInst::Predicate  Pred, Constant *  C, const ValueLatticeElement &  Val, const DataLayout &  DL  )

static

Definition at line 1787 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, llvm::ConstantFoldCompareInstOperands(), DL, llvm::ValueLatticeElement::getConstant(), llvm::ValueLatticeElement::getConstantRange(), llvm::ConstantInt::getFalse(), llvm::CmpInst::getInversePredicate(), llvm::ValueLatticeElement::getNotConstant(), llvm::ConstantInt::getTrue(), llvm::ConstantRange::icmp(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::ValueLatticeElement::isConstant(), llvm::ValueLatticeElement::isConstantRange(), llvm::ValueLatticeElement::isNotConstant(), llvm::Constant::isNullValue(), llvm::CmpInst::makeCmpResultType(), and RHS.

Referenced by llvm::LazyValueInfo::getPredicateAt(), and llvm::LazyValueInfo::getPredicateOnEdge().

getRangeViaSLT()

static std::optional< ConstantRange > getRangeViaSLT ( CmpInst::Predicate  Pred, APInt  RHS, function_ref< std::optional< ConstantRange >(const APInt &)>  Fn  )

static

Definition at line 1140 of file LazyValueInfo.cpp.

References assert(), llvm::CmpInst::getInversePredicate(), llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, and RHS.

getValueFromOverflowCondition()

static ValueLatticeElement getValueFromOverflowCondition ( Value *  Val, WithOverflowInst *  WO, bool  IsTrueDest  )

static

Definition at line 1247 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, llvm::BinaryOpIntrinsic::getBinaryOp(), llvm::BinaryOpIntrinsic::getLHS(), llvm::BinaryOpIntrinsic::getNoWrapKind(), llvm::ValueLatticeElement::getOverdefined(), llvm::ValueLatticeElement::getRange(), llvm::BinaryOpIntrinsic::getRHS(), llvm::ConstantRange::inverse(), llvm::PatternMatch::m_APInt(), llvm::ConstantRange::makeExactNoWrapRegion(), and llvm::PatternMatch::match().

hasSingleValue()

static bool hasSingleValue ( const ValueLatticeElement &  Val )

static

Returns true if this lattice value represents at most one possible value.

This is as precise as any lattice value can get while still representing reachable code.

Definition at line 75 of file LazyValueInfo.cpp.

References llvm::ValueLatticeElement::getConstantRange(), llvm::ValueLatticeElement::isConstant(), llvm::ValueLatticeElement::isConstantRange(), and llvm::ConstantRange::isSingleElement().

Referenced by intersect().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	LazyValueInfoWrapperPass	,
		"lazy-value-info"	,
		"Lazy Value Information Analysis"	,
		false	,
		true
	)

intersect()

static ValueLatticeElement intersect ( const ValueLatticeElement &  A, const ValueLatticeElement &  B  )

static

Combine two sets of facts about the same value into a single set of facts.

Note that this method is not suitable for merging facts along different paths in a CFG; that's what the mergeIn function is for. This is for merging facts gathered about the same value at the same location through two independent means. Notes:

• This method does not promise to return the most precise possible lattice value implied by A and B. It is allowed to return any lattice element which is at least as strong as either A or B (unless our facts conflict, see below).
• Due to unreachable code, the intersection of two lattice values could be contradictory. If this happens, we return some valid lattice value so as not confuse the rest of LVI. Ideally, we'd always return Undefined, but we do not make this guarantee. TODO: This would be a useful enhancement.

Definition at line 100 of file LazyValueInfo.cpp.

References A, B, llvm::ValueLatticeElement::getRange(), hasSingleValue(), and Range.

Referenced by llvm::LazyValueInfoImpl::getValueAtUse(), and llvm::msf::MappedBlockStream::readBytes().

isKnownNonConstant()

static bool isKnownNonConstant ( Value *  V )

static

Returns true if we can statically tell that this value will never be a "useful" constant.

In practice, this means we've got something like an alloca or a malloc call for which a comparison against a constant can only be guarding dead code. Note that we are potentially giving up some precision in dead code (a constant result) in favour of avoiding a expensive search for a easily answered common query.

Definition at line 1714 of file LazyValueInfo.cpp.

Referenced by llvm::LazyValueInfo::getConstant().

isOperationFoldable()

static bool isOperationFoldable ( User *  Usr )

static

Definition at line 1325 of file LazyValueInfo.cpp.

Referenced by constantFoldUser().

matchICmpOperand()

static bool matchICmpOperand ( APInt &  Offset, Value *  LHS, Value *  Val, ICmpInst::Predicate  Pred  )

static

Definition at line 1082 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, LHS, llvm::PatternMatch::m_AddLike(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Or(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and llvm::Offset.

usesOperand()

static bool usesOperand ( User *  Usr, Value *  Op  )

static

Definition at line 1317 of file LazyValueInfo.cpp.

References llvm::is_contained(), and llvm::User::operands().

Variable Documentation

Analysis

lazy value Lazy Value Information Analysis

Definition at line 62 of file LazyValueInfo.cpp.

false

lazy value Lazy Value Information false

Definition at line 62 of file LazyValueInfo.cpp.

info

lazy value info

Definition at line 61 of file LazyValueInfo.cpp.

Referenced by ARM64EmitRuntimeFunction(), ARM64EmitUnwindInfo(), ARM64EmitUnwindInfoForSegment(), ARM64FindSegmentsInFunction(), ARM64ProcessEpilogs(), ARMEmitRuntimeFunction(), ARMEmitUnwindInfo(), checkARM64PackedEpilog(), checkARMPackedEpilog(), EmitRuntimeFunction(), llvm::Win64EH::UnwindEmitter::EmitUnwindInfo(), llvm::Win64EH::ARMUnwindEmitter::EmitUnwindInfo(), llvm::Win64EH::ARM64UnwindEmitter::EmitUnwindInfo(), EmitUnwindInfo(), findLiveReferences(), FindMatchingEpilog(), llvm::CCState::getInRegsParamInfo(), llvm::TargetLowering::getMultipleConstraintMatchWeight(), llvm::TargetLowering::getSingleConstraintMatchWeight(), llvm::ARMTargetLowering::getSingleConstraintMatchWeight(), llvm::AVRTargetLowering::getSingleConstraintMatchWeight(), llvm::PPCTargetLowering::getSingleConstraintMatchWeight(), llvm::SparcTargetLowering::getSingleConstraintMatchWeight(), llvm::SystemZTargetLowering::getSingleConstraintMatchWeight(), insertParsePoints(), recomputeLiveInValues(), llvm::MachO::swapStruct(), tryARM64PackedUnwind(), and tryARMPackedUnwind().

MaxProcessedPerValue

const unsigned MaxProcessedPerValue = 500

static

Definition at line 51 of file LazyValueInfo.cpp.