LLVM 22.0.0git
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
llvm::KnownFPClass Struct Reference

#include "llvm/Support/KnownFPClass.h"

Public Member Functions

 KnownFPClass ()=default
 KnownFPClass (const APFloat &C)
bool operator== (KnownFPClass Other) const
bool isKnownNever (FPClassTest Mask) const
 Return true if it's known this can never be one of the mask entries.
bool isKnownAlways (FPClassTest Mask) const
bool isUnknown () const
bool isKnownNeverNaN () const
 Return true if it's known this can never be a nan.
bool isKnownAlwaysNaN () const
 Return true if it's known this must always 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.
LLVM_ABI bool isKnownNeverLogicalZero (DenormalMode Mode) const
 Return true if it's know this can never be interpreted as a zero.
LLVM_ABI bool isKnownNeverLogicalNegZero (DenormalMode Mode) const
 Return true if it's know this can never be interpreted as a negative zero.
LLVM_ABI bool isKnownNeverLogicalPosZero (DenormalMode Mode) 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 signBitMustBeOne ()
 Assume the sign bit is one.
void copysign (const KnownFPClass &Sign)
void propagateNaN (const KnownFPClass &Src, bool PreserveSign=false)
LLVM_ABI void propagateDenormal (const KnownFPClass &Src, DenormalMode Mode)
 Propagate knowledge from a source value that could be a denormal or zero.
LLVM_ABI void propagateCanonicalizingSrc (const KnownFPClass &Src, DenormalMode Mode)
 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 24 of file KnownFPClass.h.

Constructor & Destructor Documentation

◆ KnownFPClass() [1/2]

llvm::KnownFPClass::KnownFPClass ( )
default

References llvm::CallingConv::C.

Referenced by copysign(), operator==(), operator|=(), propagateCanonicalizingSrc(), propagateDenormal(), propagateNaN(), and resetAll().

◆ KnownFPClass() [2/2]

KnownFPClass::KnownFPClass ( const APFloat & C)

Definition at line 20 of file KnownFPClass.cpp.

References llvm::CallingConv::C, KnownFPClasses, and SignBit.

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 118 of file KnownFPClass.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 107 of file KnownFPClass.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 177 of file KnownFPClass.h.

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

Referenced by computeKnownFPClass(), and llvm::InstCombinerImpl::SimplifyDemandedUseFPClass().

◆ fabs()

void llvm::KnownFPClass::fabs ( )
inline

Definition at line 146 of file KnownFPClass.h.

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

Referenced by computeKnownFPClass(), and llvm::InstCombinerImpl::SimplifyDemandedUseFPClass().

◆ fneg()

void llvm::KnownFPClass::fneg ( )
inline

Definition at line 140 of file KnownFPClass.h.

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

Referenced by computeKnownFPClass(), and llvm::InstCombinerImpl::SimplifyDemandedUseFPClass().

◆ isKnownAlways()

bool llvm::KnownFPClass::isKnownAlways ( FPClassTest Mask) const
inline

Definition at line 44 of file KnownFPClass.h.

References isKnownNever().

Referenced by computeKnownFPClass(), and isKnownAlwaysNaN().

◆ isKnownAlwaysNaN()

bool llvm::KnownFPClass::isKnownAlwaysNaN ( ) const
inline

Return true if it's known this must always be a nan.

Definition at line 52 of file KnownFPClass.h.

References llvm::fcNan, and isKnownAlways().

Referenced by simplifyFCmpInst().

◆ 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 40 of file KnownFPClass.h.

References llvm::fcNone, and KnownFPClasses.

Referenced by cannotBeOrderedGreaterThanZero(), cannotBeOrderedLessThanZero(), computeKnownFPClass(), copysign(), foldFPtoI(), isKnownAlways(), isKnownNeverInfinity(), isKnownNeverNaN(), isKnownNeverNegInfinity(), isKnownNeverNegSubnormal(), isKnownNeverNegZero(), isKnownNeverPosInfinity(), isKnownNeverPosSubnormal(), isKnownNeverPosZero(), isKnownNeverSubnormal(), isKnownNeverZero(), knownNot(), signBitIsZeroOrNaN(), llvm::InstCombinerImpl::SimplifyDemandedUseFPClass(), and simplifyFMAFMul().

◆ isKnownNeverInfinity()

bool llvm::KnownFPClass::isKnownNeverInfinity ( ) const
inline

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

Definition at line 55 of file KnownFPClass.h.

References llvm::fcInf, and isKnownNever().

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

◆ isKnownNeverLogicalNegZero()

bool KnownFPClass::isKnownNeverLogicalNegZero ( DenormalMode Mode) const

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

Definition at line 39 of file KnownFPClass.cpp.

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

Referenced by computeKnownFPClass().

◆ isKnownNeverLogicalPosZero()

bool KnownFPClass::isKnownNeverLogicalPosZero ( DenormalMode Mode) const

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

Definition at line 44 of file KnownFPClass.cpp.

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

Referenced by computeKnownFPClass().

◆ isKnownNeverLogicalZero()

bool KnownFPClass::isKnownNeverLogicalZero ( DenormalMode Mode) 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 34 of file KnownFPClass.cpp.

References 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 49 of file KnownFPClass.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 61 of file KnownFPClass.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 70 of file KnownFPClass.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 81 of file KnownFPClass.h.

References llvm::fcNegZero, and isKnownNever().

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

◆ isKnownNeverPosInfinity()

bool llvm::KnownFPClass::isKnownNeverPosInfinity ( ) const
inline

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

Definition at line 58 of file KnownFPClass.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 67 of file KnownFPClass.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 77 of file KnownFPClass.h.

References llvm::fcPosZero, and isKnownNever().

Referenced by computeKnownFPClass(), and isKnownNeverLogicalPosZero().

◆ isKnownNeverSubnormal()

bool llvm::KnownFPClass::isKnownNeverSubnormal ( ) const
inline

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

Definition at line 64 of file KnownFPClass.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 74 of file KnownFPClass.h.

References llvm::fcZero, and isKnownNever().

Referenced by isKnownNeverLogicalZero(), and llvm::LegalizerHelper::lowerFMinimumMaximum().

◆ isUnknown()

bool llvm::KnownFPClass::isUnknown ( ) const
inline

Definition at line 46 of file KnownFPClass.h.

References llvm::fcAllFlags, KnownFPClasses, and SignBit.

Referenced by computeKnownFPClass().

◆ knownNot()

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

Definition at line 130 of file KnownFPClass.h.

References llvm::fcNan, llvm::fcNegative, llvm::fcPositive, isKnownNever(), KnownFPClasses, and SignBit.

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

◆ operator==()

bool llvm::KnownFPClass::operator== ( KnownFPClass Other) const
inline

Definition at line 35 of file KnownFPClass.h.

References KnownFPClass(), KnownFPClasses, llvm::Other, and SignBit.

◆ operator|=()

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

Definition at line 122 of file KnownFPClass.h.

References KnownFPClass(), KnownFPClasses, RHS, and SignBit.

◆ propagateCanonicalizingSrc()

void KnownFPClass::propagateCanonicalizingSrc ( const KnownFPClass & Src,
DenormalMode Mode )

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 94 of file KnownFPClass.cpp.

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

Referenced by computeKnownFPClass().

◆ propagateDenormal()

void KnownFPClass::propagateDenormal ( const KnownFPClass & Src,
DenormalMode Mode )

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 67 of file KnownFPClass.cpp.

References llvm::DenormalMode::Dynamic, llvm::fcNegZero, llvm::fcPosZero, llvm::DenormalMode::getIEEE(), llvm::DenormalMode::getPositiveZero(), KnownFPClass(), KnownFPClasses, and llvm::DenormalMode::PositiveZero.

Referenced by propagateCanonicalizingSrc().

◆ propagateNaN()

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

Definition at line 202 of file KnownFPClass.h.

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

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

◆ resetAll()

void llvm::KnownFPClass::resetAll ( )
inline

Definition at line 228 of file KnownFPClass.h.

References KnownFPClass().

Referenced by computeKnownFPClass(), and llvm::TargetLowering::computeKnownFPClassForTargetInstr().

◆ signBitIsZeroOrNaN()

bool llvm::KnownFPClass::signBitIsZeroOrNaN ( ) const
inline

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

Definition at line 163 of file KnownFPClass.h.

References llvm::fcNegative, and isKnownNever().

◆ signBitMustBeOne()

void llvm::KnownFPClass::signBitMustBeOne ( )
inline

Assume the sign bit is one.

Definition at line 172 of file KnownFPClass.h.

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

Referenced by computeKnownFPClass(), and computeKnownFPClassFromCond().

◆ signBitMustBeZero()

void llvm::KnownFPClass::signBitMustBeZero ( )
inline

Assume the sign bit is zero.

Definition at line 166 of file KnownFPClass.h.

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

Referenced by computeKnownFPClass(), computeKnownFPClassFromCond(), and fabs().

Member Data Documentation

◆ KnownFPClasses

FPClassTest llvm::KnownFPClass::KnownFPClasses = fcAllFlags

Floating-point classes the value could be one of.

Definition at line 26 of file KnownFPClass.h.

Referenced by computeKnownFPClass(), copysign(), fabs(), fneg(), isKnownNever(), isUnknown(), KnownFPClass(), knownNot(), operator==(), operator|=(), propagateDenormal(), signBitMustBeOne(), signBitMustBeZero(), and llvm::InstCombinerImpl::SimplifyDemandedUseFPClass().

◆ OrderedGreaterThanZeroMask

FPClassTest llvm::KnownFPClass::OrderedGreaterThanZeroMask
staticconstexpr
Initial value:
=
fcPosSubnormal | fcPosNormal | fcPosInf

Definition at line 96 of file KnownFPClass.h.

Referenced by cannotBeOrderedGreaterThanZero(), and computeKnownFPClass().

◆ OrderedLessThanZeroMask

FPClassTest llvm::KnownFPClass::OrderedLessThanZeroMask
staticconstexpr
Initial value:
=
fcNegSubnormal | fcNegNormal | fcNegInf

Definition at line 94 of file KnownFPClass.h.

Referenced by llvm::cannotBeOrderedLessThanZero(), 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 30 of file KnownFPClass.h.

Referenced by computeKnownFPClass(), llvm::computeKnownFPSignBit(), copysign(), fneg(), isUnknown(), KnownFPClass(), knownNot(), operator==(), operator|=(), propagateNaN(), signBitMustBeOne(), signBitMustBeZero(), and simplifyFMAFMul().

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