#include "llvm/Analysis/ValueTracking.h"

Public Member Functions
bool	isKnownNever (FPClassTest Mask) const
	Return true if it's known this can never be one of the mask entries.

bool	isUnknown () const

bool	isKnownNeverNaN () const
	Return true if it's known this can never be a nan.

bool	isKnownNeverInfinity () const
	Return true if it's known this can never be an infinity.

bool	isKnownNeverPosInfinity () const
	Return true if it's known this can never be +infinity.

bool	isKnownNeverNegInfinity () const
	Return true if it's known this can never be -infinity.

bool	isKnownNeverSubnormal () const
	Return true if it's known this can never be a subnormal.

bool	isKnownNeverPosSubnormal () const
	Return true if it's known this can never be a positive subnormal.

bool	isKnownNeverNegSubnormal () const
	Return true if it's known this can never be a negative subnormal.

bool	isKnownNeverZero () const
	Return true if it's known this can never be a zero.

bool	isKnownNeverPosZero () const
	Return true if it's known this can never be a literal positive zero.

bool	isKnownNeverNegZero () const
	Return true if it's known this can never be a negative zero.

bool	isKnownNeverLogicalZero (const Function &F, Type *Ty) const
	Return true if it's know this can never be interpreted as a zero.

bool	isKnownNeverLogicalNegZero (const Function &F, Type *Ty) const
	Return true if it's know this can never be interpreted as a negative zero.

bool	isKnownNeverLogicalPosZero (const Function &F, Type *Ty) const
	Return true if it's know this can never be interpreted as a positive zero.

bool	cannotBeOrderedLessThanZero () const
	Return true if we can prove that the analyzed floating-point value is either NaN or never less than -0.0.

bool	cannotBeOrderedGreaterThanZero () const
	Return true if we can prove that the analyzed floating-point value is either NaN or never greater than -0.0.

KnownFPClass &	operator\|= (const KnownFPClass &RHS)

void	knownNot (FPClassTest RuleOut)

void	fneg ()

void	fabs ()

bool	signBitIsZeroOrNaN () const
	Return true if the sign bit must be 0, ignoring the sign of nans.

void	signBitMustBeZero ()
	Assume the sign bit is zero.

void	copysign (const KnownFPClass &Sign)

void	propagateNaN (const KnownFPClass &Src, bool PreserveSign=false)

void	propagateDenormal (const KnownFPClass &Src, const Function &F, Type *Ty)
	Propagate knowledge from a source value that could be a denormal or zero.

void	propagateCanonicalizingSrc (const KnownFPClass &Src, const Function &F, Type *Ty)
	Report known classes if `Src` is evaluated through a potentially canonicalizing operation.

void	resetAll ()

Public Attributes
FPClassTest	KnownFPClasses = fcAllFlags
	Floating-point classes the value could be one of.

std::optional< bool >	SignBit
	std::nullopt if the sign bit is unknown, true if the sign bit is definitely set or false if the sign bit is definitely unset.

Static Public Attributes
static constexpr FPClassTest	OrderedLessThanZeroMask

static constexpr FPClassTest	OrderedGreaterThanZeroMask

Detailed Description

Definition at line 217 of file ValueTracking.h.

Member Function Documentation

◆ cannotBeOrderedGreaterThanZero()

bool llvm::KnownFPClass::cannotBeOrderedGreaterThanZero ( ) const

inline

Return true if we can prove that the analyzed floating-point value is either NaN or never greater than -0.0.

NaN --> true +0 --> true -0 --> true x > +0 --> false x < -0 --> true

Definition at line 321 of file ValueTracking.h.

References isKnownNever(), and OrderedGreaterThanZeroMask.

Referenced by computeKnownFPClass().

◆ cannotBeOrderedLessThanZero()

bool llvm::KnownFPClass::cannotBeOrderedLessThanZero ( ) const

inline

Return true if we can prove that the analyzed floating-point value is either NaN or never less than -0.0.

 NaN --> true
  +0 --> true
  -0 --> true

x > +0 --> true x < -0 --> false

Definition at line 310 of file ValueTracking.h.

References isKnownNever(), and OrderedLessThanZeroMask.

Referenced by llvm::cannotBeOrderedLessThanZero(), computeKnownFPClass(), computeKnownFPClassForFPTrunc(), and simplifyFCmpInst().

◆ copysign()

void llvm::KnownFPClass::copysign ( const KnownFPClass & Sign )

inline

Definition at line 370 of file ValueTracking.h.

References llvm::fcInf, llvm::fcNan, llvm::fcNegative, llvm::fcNormal, llvm::fcPositive, llvm::fcSubnormal, llvm::fcZero, isKnownNever(), KnownFPClasses, and SignBit.

Referenced by computeKnownFPClass().

◆ fabs()

void llvm::KnownFPClass::fabs ( )

inline

Definition at line 343 of file ValueTracking.h.

References llvm::fcNegInf, llvm::fcNegNormal, llvm::fcNegSubnormal, llvm::fcNegZero, llvm::fcPosInf, llvm::fcPosNormal, llvm::fcPosSubnormal, llvm::fcPosZero, KnownFPClasses, and signBitMustBeZero().

Referenced by computeKnownFPClass().

◆ fneg()

void llvm::KnownFPClass::fneg ( )

inline

Definition at line 337 of file ValueTracking.h.

References llvm::fneg(), KnownFPClasses, and SignBit.

Referenced by computeKnownFPClass().

◆ isKnownNever()

bool llvm::KnownFPClass::isKnownNever ( FPClassTest Mask ) const

inline

Return true if it's known this can never be one of the mask entries.

Definition at line 226 of file ValueTracking.h.

References llvm::fcNone, and KnownFPClasses.

Referenced by cannotBeOrderedGreaterThanZero(), cannotBeOrderedLessThanZero(), computeKnownFPClass(), copysign(), isKnownNeverInfinity(), isKnownNeverNaN(), isKnownNeverNegInfinity(), isKnownNeverNegSubnormal(), isKnownNeverNegZero(), isKnownNeverPosInfinity(), isKnownNeverPosSubnormal(), isKnownNeverPosZero(), isKnownNeverSubnormal(), isKnownNeverZero(), and signBitIsZeroOrNaN().

◆ isKnownNeverInfinity()

bool llvm::KnownFPClass::isKnownNeverInfinity ( ) const

inline

Return true if it's known this can never be an infinity.

Definition at line 240 of file ValueTracking.h.

References llvm::fcInf, and isKnownNever().

Referenced by computeKnownFPClass(), llvm::isKnownNeverInfinity(), and llvm::isKnownNeverInfOrNaN().

◆ isKnownNeverLogicalNegZero()

bool KnownFPClass::isKnownNeverLogicalNegZero	(	const Function &	F,
		Type *	Ty
	)		const

Return true if it's know this can never be interpreted as a negative zero.

Definition at line 3871 of file ValueTracking.cpp.

References F, inputDenormalIsIEEEOrPosZero(), isKnownNeverNegSubnormal(), and isKnownNeverNegZero().

Referenced by computeKnownFPClass().

◆ isKnownNeverLogicalPosZero()

bool KnownFPClass::isKnownNeverLogicalPosZero	(	const Function &	F,
		Type *	Ty
	)		const

Return true if it's know this can never be interpreted as a positive zero.

Definition at line 3877 of file ValueTracking.cpp.

References F, llvm::Type::getFltSemantics(), llvm::Type::getScalarType(), llvm::DenormalMode::IEEE, isKnownNeverPosSubnormal(), isKnownNeverPosZero(), isKnownNeverSubnormal(), llvm_unreachable, llvm::DenormalMode::PositiveZero, and llvm::DenormalMode::PreserveSign.

Referenced by computeKnownFPClass().

◆ isKnownNeverLogicalZero()

bool KnownFPClass::isKnownNeverLogicalZero	(	const Function &	F,
		Type *	Ty
	)		const

Return true if it's know this can never be interpreted as a zero.

This extends isKnownNeverZero to cover the case where the assumed floating-point mode for the function interprets denormals as zero.

Definition at line 3866 of file ValueTracking.cpp.

References F, inputDenormalIsIEEE(), isKnownNeverSubnormal(), and isKnownNeverZero().

Referenced by computeKnownFPClass().

◆ isKnownNeverNaN()

bool llvm::KnownFPClass::isKnownNeverNaN ( ) const

inline

Return true if it's known this can never be a nan.

Definition at line 235 of file ValueTracking.h.

References llvm::fcNan, and isKnownNever().

Referenced by computeKnownFPClass(), llvm::isKnownNeverInfOrNaN(), llvm::isKnownNeverNaN(), and simplifyFCmpInst().

◆ isKnownNeverNegInfinity()

bool llvm::KnownFPClass::isKnownNeverNegInfinity ( ) const

inline

Return true if it's known this can never be -infinity.

Definition at line 250 of file ValueTracking.h.

References llvm::fcNegInf, and isKnownNever().

Referenced by computeKnownFPClass().

◆ isKnownNeverNegSubnormal()

bool llvm::KnownFPClass::isKnownNeverNegSubnormal ( ) const

inline

Return true if it's known this can never be a negative subnormal.

Definition at line 265 of file ValueTracking.h.

References llvm::fcNegSubnormal, and isKnownNever().

Referenced by computeKnownFPClass(), and isKnownNeverLogicalNegZero().

◆ isKnownNeverNegZero()

bool llvm::KnownFPClass::isKnownNeverNegZero ( ) const

inline

Return true if it's known this can never be a negative zero.

This means a literal -0 and does not include denormal inputs implicitly treated as -0.

Definition at line 282 of file ValueTracking.h.

References llvm::fcNegZero, and isKnownNever().

Referenced by llvm::cannotBeNegativeZero(), and isKnownNeverLogicalNegZero().

◆ isKnownNeverPosInfinity()

bool llvm::KnownFPClass::isKnownNeverPosInfinity ( ) const

inline

Return true if it's known this can never be +infinity.

Definition at line 245 of file ValueTracking.h.

References llvm::fcPosInf, and isKnownNever().

Referenced by computeKnownFPClass().

◆ isKnownNeverPosSubnormal()

bool llvm::KnownFPClass::isKnownNeverPosSubnormal ( ) const

inline

Return true if it's known this can never be a positive subnormal.

Definition at line 260 of file ValueTracking.h.

References llvm::fcPosSubnormal, and isKnownNever().

Referenced by computeKnownFPClass(), and isKnownNeverLogicalPosZero().

◆ isKnownNeverPosZero()

bool llvm::KnownFPClass::isKnownNeverPosZero ( ) const

inline

Return true if it's known this can never be a literal positive zero.

Definition at line 276 of file ValueTracking.h.

References llvm::fcPosZero, and isKnownNever().

Referenced by isKnownNeverLogicalPosZero().

◆ isKnownNeverSubnormal()

bool llvm::KnownFPClass::isKnownNeverSubnormal ( ) const

inline

Return true if it's known this can never be a subnormal.

Definition at line 255 of file ValueTracking.h.

References llvm::fcSubnormal, and isKnownNever().

Referenced by computeKnownFPClass(), isKnownNeverLogicalPosZero(), and isKnownNeverLogicalZero().

◆ isKnownNeverZero()

bool llvm::KnownFPClass::isKnownNeverZero ( ) const

inline

Return true if it's known this can never be a zero.

This means a literal [+-]0, and does not include denormal inputs implicitly treated as [+-]0.

Definition at line 271 of file ValueTracking.h.

References llvm::fcZero, and isKnownNever().

Referenced by isKnownNeverLogicalZero().

◆ isUnknown()

bool llvm::KnownFPClass::isUnknown ( ) const

inline

Definition at line 230 of file ValueTracking.h.

References llvm::fcAllFlags, KnownFPClasses, and SignBit.

Referenced by computeKnownFPClass().

◆ knownNot()

void llvm::KnownFPClass::knownNot ( FPClassTest RuleOut )

inline

Definition at line 333 of file ValueTracking.h.

References KnownFPClasses.

Referenced by computeKnownFPClass(), computeKnownFPClassForFPTrunc(), and propagateNaN().

◆ operator|=()

KnownFPClass & llvm::KnownFPClass::operator|= ( const KnownFPClass & RHS )

inline

Definition at line 325 of file ValueTracking.h.

References KnownFPClasses, RHS, and SignBit.

◆ propagateCanonicalizingSrc()

void KnownFPClass::propagateCanonicalizingSrc	(	const KnownFPClass &	Src,
		const Function &	F,
		Type *	Ty
	)

Report known classes if Src is evaluated through a potentially canonicalizing operation.

We can assume signaling nans will not be introduced, but cannot assume a denormal will be flushed under FTZ/DAZ.

This assumes a copy-like operation and will replace any currently known information.

Definition at line 3931 of file ValueTracking.cpp.

References F, propagateDenormal(), and propagateNaN().

Referenced by computeKnownFPClass().

◆ propagateDenormal()

void KnownFPClass::propagateDenormal	(	const KnownFPClass &	Src,
		const Function &	F,
		Type *	Ty
	)

Propagate knowledge from a source value that could be a denormal or zero.

We have to be conservative since output flushing is not guaranteed, so known-never-zero may not hold.

This assumes a copy-like operation and will replace any currently known information.

Definition at line 3902 of file ValueTracking.cpp.

References llvm::DenormalMode::Dynamic, F, llvm::fcNegZero, llvm::fcPosZero, llvm::Type::getFltSemantics(), llvm::DenormalMode::getIEEE(), llvm::DenormalMode::getPositiveZero(), llvm::Type::getScalarType(), KnownFPClasses, and llvm::DenormalMode::PositiveZero.

Referenced by propagateCanonicalizingSrc().

◆ propagateNaN()

void llvm::KnownFPClass::propagateNaN	(	const KnownFPClass &	Src,
		bool	PreserveSign = `false`
	)

inline

Definition at line 395 of file ValueTracking.h.

References llvm::fcNan, llvm::fcSNan, knownNot(), and SignBit.

Referenced by computeKnownFPClass(), computeKnownFPClassForFPTrunc(), and propagateCanonicalizingSrc().

◆ resetAll()

void llvm::KnownFPClass::resetAll ( )

inline

Definition at line 421 of file ValueTracking.h.

Referenced by computeKnownFPClass().

◆ signBitIsZeroOrNaN()

bool llvm::KnownFPClass::signBitIsZeroOrNaN ( ) const

inline

Return true if the sign bit must be 0, ignoring the sign of nans.

Definition at line 360 of file ValueTracking.h.

References llvm::fcNegative, and isKnownNever().

◆ signBitMustBeZero()

void llvm::KnownFPClass::signBitMustBeZero ( )

inline

Assume the sign bit is zero.

Definition at line 365 of file ValueTracking.h.

References llvm::fcNan, llvm::fcPositive, KnownFPClasses, and SignBit.

Referenced by computeKnownFPClass(), and fabs().

Member Data Documentation

◆ KnownFPClasses

FPClassTest llvm::KnownFPClass::KnownFPClasses = fcAllFlags

Floating-point classes the value could be one of.

Definition at line 219 of file ValueTracking.h.

Referenced by computeKnownFPClass(), copysign(), fabs(), fneg(), isKnownNever(), isUnknown(), knownNot(), operator|=(), propagateDenormal(), and signBitMustBeZero().

◆ OrderedGreaterThanZeroMask

constexpr FPClassTest llvm::KnownFPClass::OrderedGreaterThanZeroMask

staticconstexpr

Initial value:

=

fcPosSubnormal | fcPosNormal | fcPosInf

llvm::fcPosNormal

@ fcPosNormal

Definition: FloatingPointMode.h:250

llvm::fcPosSubnormal

@ fcPosSubnormal

Definition: FloatingPointMode.h:249

llvm::fcPosInf

@ fcPosInf

Definition: FloatingPointMode.h:251

Definition at line 299 of file ValueTracking.h.

Referenced by cannotBeOrderedGreaterThanZero(), and computeKnownFPClass().

◆ OrderedLessThanZeroMask

constexpr FPClassTest llvm::KnownFPClass::OrderedLessThanZeroMask

staticconstexpr

Initial value:

=

fcNegSubnormal | fcNegNormal | fcNegInf

llvm::fcNegSubnormal

@ fcNegSubnormal

Definition: FloatingPointMode.h:246

llvm::fcNegInf

@ fcNegInf

Definition: FloatingPointMode.h:244

llvm::fcNegNormal

@ fcNegNormal

Definition: FloatingPointMode.h:245

Definition at line 297 of file ValueTracking.h.

Referenced by cannotBeOrderedLessThanZero(), llvm::cannotBeOrderedLessThanZero(), computeKnownFPClass(), computeKnownFPClassForFPTrunc(), and simplifyFCmpInst().

◆ SignBit

std::optional<bool> llvm::KnownFPClass::SignBit

std::nullopt if the sign bit is unknown, true if the sign bit is definitely set or false if the sign bit is definitely unset.

Definition at line 223 of file ValueTracking.h.

Referenced by computeKnownFPClass(), copysign(), fneg(), isUnknown(), operator|=(), propagateNaN(), and signBitMustBeZero().

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

include/llvm/Analysis/ValueTracking.h
lib/Analysis/ValueTracking.cpp

Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Member Function Documentation

◆ cannotBeOrderedGreaterThanZero()

◆ cannotBeOrderedLessThanZero()

◆ copysign()

◆ fabs()

◆ fneg()

◆ isKnownNever()

◆ isKnownNeverInfinity()

◆ isKnownNeverLogicalNegZero()

◆ isKnownNeverLogicalPosZero()

◆ isKnownNeverLogicalZero()

◆ isKnownNeverNaN()

◆ isKnownNeverNegInfinity()

◆ isKnownNeverNegSubnormal()

◆ isKnownNeverNegZero()

◆ isKnownNeverPosInfinity()

◆ isKnownNeverPosSubnormal()

◆ isKnownNeverPosZero()

◆ isKnownNeverSubnormal()

◆ isKnownNeverZero()

◆ isUnknown()

◆ knownNot()

◆ operator|=()

◆ propagateCanonicalizingSrc()

◆ propagateDenormal()

◆ propagateNaN()

◆ resetAll()

◆ signBitIsZeroOrNaN()

◆ signBitMustBeZero()

Member Data Documentation

◆ KnownFPClasses

◆ OrderedGreaterThanZeroMask

◆ OrderedLessThanZeroMask

◆ SignBit