#include "llvm/Support/KnownBits.h"

Public Member Functions
	KnownBits ()=default

	KnownBits (unsigned BitWidth)
	Create a known bits object of BitWidth bits initialized to unknown.

unsigned	getBitWidth () const
	Get the bit width of this value.

bool	hasConflict () const
	Returns true if there is conflicting information.

bool	isConstant () const
	Returns true if we know the value of all bits.

const APInt &	getConstant () const
	Returns the value when all bits have a known value.

bool	isUnknown () const
	Returns true if we don't know any bits.

bool	isSignUnknown () const
	Returns true if we don't know the sign bit.

void	resetAll ()
	Resets the known state of all bits.

bool	isZero () const
	Returns true if value is all zero.

bool	isAllOnes () const
	Returns true if value is all one bits.

void	setAllZero ()
	Make all bits known to be zero and discard any previous information.

void	setAllOnes ()
	Make all bits known to be one and discard any previous information.

bool	isNegative () const
	Returns true if this value is known to be negative.

bool	isNonNegative () const
	Returns true if this value is known to be non-negative.

bool	isNonZero () const
	Returns true if this value is known to be non-zero.

bool	isStrictlyPositive () const
	Returns true if this value is known to be positive.

void	makeNegative ()
	Make this value negative.

void	makeNonNegative ()
	Make this value non-negative.

APInt	getMinValue () const
	Return the minimal unsigned value possible given these KnownBits.

APInt	getSignedMinValue () const
	Return the minimal signed value possible given these KnownBits.

APInt	getMaxValue () const
	Return the maximal unsigned value possible given these KnownBits.

APInt	getSignedMaxValue () const
	Return the maximal signed value possible given these KnownBits.

KnownBits	trunc (unsigned BitWidth) const
	Return known bits for a truncation of the value we're tracking.

KnownBits	anyext (unsigned BitWidth) const
	Return known bits for an "any" extension of the value we're tracking, where we don't know anything about the extended bits.

KnownBits	zext (unsigned BitWidth) const
	Return known bits for a zero extension of the value we're tracking.

KnownBits	sext (unsigned BitWidth) const
	Return known bits for a sign extension of the value we're tracking.

KnownBits	anyextOrTrunc (unsigned BitWidth) const
	Return known bits for an "any" extension or truncation of the value we're tracking.

KnownBits	zextOrTrunc (unsigned BitWidth) const
	Return known bits for a zero extension or truncation of the value we're tracking.

KnownBits	sextOrTrunc (unsigned BitWidth) const
	Return known bits for a sign extension or truncation of the value we're tracking.

KnownBits	sextInReg (unsigned SrcBitWidth) const
	Return known bits for a in-register sign extension of the value we're tracking.

void	insertBits (const KnownBits &SubBits, unsigned BitPosition)
	Insert the bits from a smaller known bits starting at bitPosition.

KnownBits	extractBits (unsigned NumBits, unsigned BitPosition) const
	Return a subset of the known bits from [bitPosition,bitPosition+numBits).

KnownBits	concat (const KnownBits &Lo) const
	Concatenate the bits from `Lo` onto the bottom of *this.

KnownBits	makeGE (const APInt &Val) const
	Return KnownBits based on this, but updated given that the underlying value is known to be greater than or equal to Val.

unsigned	countMinTrailingZeros () const
	Returns the minimum number of trailing zero bits.

unsigned	countMinTrailingOnes () const
	Returns the minimum number of trailing one bits.

unsigned	countMinLeadingZeros () const
	Returns the minimum number of leading zero bits.

unsigned	countMinLeadingOnes () const
	Returns the minimum number of leading one bits.

unsigned	countMinSignBits () const
	Returns the number of times the sign bit is replicated into the other bits.

unsigned	countMaxSignificantBits () const
	Returns the maximum number of bits needed to represent all possible signed values with these known bits.

unsigned	countMaxTrailingZeros () const
	Returns the maximum number of trailing zero bits possible.

unsigned	countMaxTrailingOnes () const
	Returns the maximum number of trailing one bits possible.

unsigned	countMaxLeadingZeros () const
	Returns the maximum number of leading zero bits possible.

unsigned	countMaxLeadingOnes () const
	Returns the maximum number of leading one bits possible.

unsigned	countMinPopulation () const
	Returns the number of bits known to be one.

unsigned	countMaxPopulation () const
	Returns the maximum number of bits that could be one.

unsigned	countMaxActiveBits () const
	Returns the maximum number of bits needed to represent all possible unsigned values with these known bits.

KnownBits	intersectWith (const KnownBits &RHS) const
	Returns KnownBits information that is known to be true for both this and RHS.

KnownBits	unionWith (const KnownBits &RHS) const
	Returns KnownBits information that is known to be true for either this or RHS or both.

KnownBits &	operator&= (const KnownBits &RHS)
	Update known bits based on ANDing with RHS.

KnownBits &	operator\|= (const KnownBits &RHS)
	Update known bits based on ORing with RHS.

KnownBits &	operator^= (const KnownBits &RHS)
	Update known bits based on XORing with RHS.

KnownBits	abs (bool IntMinIsPoison=false) const
	Compute known bits for the absolute value.

KnownBits	byteSwap () const

KnownBits	reverseBits () const

KnownBits	blsi () const
	Compute known bits for X & -X, which has only the lowest bit set of X set.

KnownBits	blsmsk () const
	Compute known bits for X ^ (X - 1), which has all bits up to and including the lowest set bit of X set.

bool	operator== (const KnownBits &Other) const

bool	operator!= (const KnownBits &Other) const

void	print (raw_ostream &OS) const

void	dump () const

Static Public Member Functions
static KnownBits	makeConstant (const APInt &C)
	Create known bits from a known constant.

static bool	haveNoCommonBitsSet (const KnownBits &LHS, const KnownBits &RHS)
	Return true if LHS and RHS have no common bits set.

static KnownBits	computeForAddCarry (const KnownBits &LHS, const KnownBits &RHS, const KnownBits &Carry)
	Compute known bits resulting from adding LHS, RHS and a 1-bit Carry.

static KnownBits	computeForAddSub (bool Add, bool NSW, bool NUW, const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits resulting from adding LHS and RHS.

static KnownBits	computeForSubBorrow (const KnownBits &LHS, KnownBits RHS, const KnownBits &Borrow)
	Compute known bits results from subtracting RHS from LHS with 1-bit Borrow.

static KnownBits	add (const KnownBits &LHS, const KnownBits &RHS, bool NSW=false, bool NUW=false)
	Compute knownbits resulting from addition of LHS and RHS.

static KnownBits	sub (const KnownBits &LHS, const KnownBits &RHS, bool NSW=false, bool NUW=false)
	Compute knownbits resulting from subtraction of LHS and RHS.

static KnownBits	sadd_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.sadd.sat(LHS, RHS)

static KnownBits	uadd_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.uadd.sat(LHS, RHS)

static KnownBits	ssub_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.ssub.sat(LHS, RHS)

static KnownBits	usub_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.usub.sat(LHS, RHS)

static KnownBits	avgFloorS (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgFloorS.

static KnownBits	avgFloorU (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgFloorU.

static KnownBits	avgCeilS (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgCeilS.

static KnownBits	avgCeilU (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgCeilU.

static KnownBits	mul (const KnownBits &LHS, const KnownBits &RHS, bool NoUndefSelfMultiply=false)
	Compute known bits resulting from multiplying LHS and RHS.

static KnownBits	mulhs (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits from sign-extended multiply-hi.

static KnownBits	mulhu (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits from zero-extended multiply-hi.

static KnownBits	sdiv (const KnownBits &LHS, const KnownBits &RHS, bool Exact=false)
	Compute known bits for sdiv(LHS, RHS).

static KnownBits	udiv (const KnownBits &LHS, const KnownBits &RHS, bool Exact=false)
	Compute known bits for udiv(LHS, RHS).

static KnownBits	urem (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for urem(LHS, RHS).

static KnownBits	srem (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for srem(LHS, RHS).

static KnownBits	umax (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for umax(LHS, RHS).

static KnownBits	umin (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for umin(LHS, RHS).

static KnownBits	smax (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for smax(LHS, RHS).

static KnownBits	smin (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for smin(LHS, RHS).

static KnownBits	abdu (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for abdu(LHS, RHS).

static KnownBits	abds (KnownBits LHS, KnownBits RHS)
	Compute known bits for abds(LHS, RHS).

static KnownBits	shl (const KnownBits &LHS, const KnownBits &RHS, bool NUW=false, bool NSW=false, bool ShAmtNonZero=false)
	Compute known bits for shl(LHS, RHS).

static KnownBits	lshr (const KnownBits &LHS, const KnownBits &RHS, bool ShAmtNonZero=false, bool Exact=false)
	Compute known bits for lshr(LHS, RHS).

static KnownBits	ashr (const KnownBits &LHS, const KnownBits &RHS, bool ShAmtNonZero=false, bool Exact=false)
	Compute known bits for ashr(LHS, RHS).

static std::optional< bool >	eq (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_EQ result.

static std::optional< bool >	ne (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_NE result.

static std::optional< bool >	ugt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_UGT result.

static std::optional< bool >	uge (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_UGE result.

static std::optional< bool >	ult (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_ULT result.

static std::optional< bool >	ule (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_ULE result.

static std::optional< bool >	sgt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SGT result.

static std::optional< bool >	sge (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SGE result.

static std::optional< bool >	slt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SLT result.

static std::optional< bool >	sle (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SLE result.

Public Attributes
APInt	Zero

APInt	One

Detailed Description

Definition at line 23 of file KnownBits.h.

Constructor & Destructor Documentation

◆ KnownBits() [1/2]

llvm::KnownBits::KnownBits ( )

default

Referenced by anyext(), byteSwap(), concat(), extractBits(), intersectWith(), makeConstant(), makeGE(), reverseBits(), sext(), smax(), smin(), trunc(), umin(), unionWith(), and zext().

◆ KnownBits() [2/2]

llvm::KnownBits::KnownBits ( unsigned BitWidth )

inline

Create a known bits object of BitWidth bits initialized to unknown.

Definition at line 37 of file KnownBits.h.

Member Function Documentation

◆ abds()

KnownBits KnownBits::abds	(	KnownBits	LHS,
		KnownBits	RHS
	)

static

Compute known bits for abds(LHS, RHS).

Definition at line 247 of file KnownBits.cpp.

References computeForAddSub(), intersectWith(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ abdu()

KnownBits KnownBits::abdu	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for abdu(LHS, RHS).

Definition at line 228 of file KnownBits.cpp.

References computeForAddSub(), intersectWith(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsForPSADBW().

◆ abs()

KnownBits KnownBits::abs ( bool IntMinIsPoison = false ) const

Compute known bits for the absolute value.

Definition at line 550 of file KnownBits.cpp.

References llvm::APInt::clearSignBit(), computeForAddSub(), countMaxPopulation(), countMaxTrailingZeros(), countMinLeadingZeros(), countMinPopulation(), countMinTrailingZeros(), getBitWidth(), llvm::APInt::isMinSignedValue(), isNegative(), isNonNegative(), llvm::APInt::isZero(), makeConstant(), One, llvm::APInt::popcount(), llvm::APInt::setBit(), llvm::APInt::setBits(), llvm::APInt::setLowBits(), llvm::APInt::setSignBit(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), and isKnownNonZeroFromOperator().

◆ add()

static KnownBits llvm::KnownBits::add	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	NSW = `false`,
		bool	NUW = `false`
	)

inlinestatic

Compute knownbits resulting from addition of LHS and RHS.

Definition at line 333 of file KnownBits.h.

References computeForAddSub(), LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), computeKnownBitsForPMADDWD(), computeKnownBitsForPSADBW(), llvm::SITargetLowering::computeKnownBitsForTargetInstr(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::SITargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), isNonZeroAdd(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), and llvm::InstCombinerImpl::SimplifyMultipleUseDemandedBits().

◆ anyext()

KnownBits llvm::KnownBits::anyext ( unsigned BitWidth ) const

inline

Return known bits for an "any" extension of the value we're tracking, where we don't know anything about the extended bits.

Definition at line 156 of file KnownBits.h.

References llvm::BitWidth, KnownBits(), One, Zero, and llvm::APInt::zext().

Referenced by anyextOrTrunc(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromICmpCond(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::FunctionLoweringInfo::GetLiveOutRegInfo(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ anyextOrTrunc()

KnownBits llvm::KnownBits::anyextOrTrunc ( unsigned BitWidth ) const

inline

Return known bits for an "any" extension or truncation of the value we're tracking.

Definition at line 175 of file KnownBits.h.

References anyext(), llvm::BitWidth, getBitWidth(), and trunc().

Referenced by llvm::SystemZTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::TargetLowering::SimplifyDemandedBits(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

◆ ashr()

KnownBits KnownBits::ashr	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	ShAmtNonZero = `false`,
		bool	Exact = `false`
	)

static

Compute known bits for ashr(LHS, RHS).

NOTE: RHS (shift amount) bitwidth doesn't need to be the same as LHS.

Definition at line 428 of file KnownBits.cpp.

References llvm::APInt::ashrInPlace(), llvm::BitWidth, getMaxShiftAmount(), hasConflict(), intersectWith(), isUnknown(), LHS, One, RHS, llvm::APInt::setAllBits(), setAllZero(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

◆ avgCeilS()

KnownBits KnownBits::avgCeilS	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from APIntOps::avgCeilS.

Definition at line 787 of file KnownBits.cpp.

References avgCompute(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ avgCeilU()

KnownBits KnownBits::avgCeilU	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from APIntOps::avgCeilU.

Definition at line 792 of file KnownBits.cpp.

References avgCompute(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ avgFloorS()

KnownBits KnownBits::avgFloorS	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from APIntOps::avgFloorS.

Definition at line 777 of file KnownBits.cpp.

References avgCompute(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ avgFloorU()

KnownBits KnownBits::avgFloorU	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from APIntOps::avgFloorU.

Definition at line 782 of file KnownBits.cpp.

References avgCompute(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ blsi()

KnownBits KnownBits::blsi ( ) const

Compute known bits for X & -X, which has only the lowest bit set of X set.

The name comes from the X86 BMI instruction

Definition at line 1109 of file KnownBits.cpp.

References llvm::BitWidth, countMaxTrailingZeros(), countMinTrailingZeros(), getBitWidth(), One, llvm::APInt::setBit(), llvm::APInt::setBitsFrom(), and Zero.

Referenced by getKnownBitsFromAndXorOr().

◆ blsmsk()

KnownBits KnownBits::blsmsk ( ) const

Compute known bits for X ^ (X - 1), which has all bits up to and including the lowest set bit of X set.

The name comes from the X86 BMI instruction.

Definition at line 1120 of file KnownBits.cpp.

References llvm::BitWidth, countMaxTrailingZeros(), countMinTrailingZeros(), getBitWidth(), One, llvm::APInt::setBitsFrom(), llvm::APInt::setLowBits(), and Zero.

Referenced by getKnownBitsFromAndXorOr().

◆ byteSwap()

KnownBits llvm::KnownBits::byteSwap ( ) const

inline

Definition at line 468 of file KnownBits.h.

References llvm::APInt::byteSwap(), KnownBits(), One, and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), and llvm::GISelKnownBits::computeKnownBitsImpl().

◆ computeForAddCarry()

KnownBits KnownBits::computeForAddCarry	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		const KnownBits &	Carry
	)

static

Compute known bits resulting from adding LHS, RHS and a 1-bit Carry.

Definition at line 44 of file KnownBits.cpp.

References assert(), getBitWidth(), llvm::APInt::getBoolValue(), LHS, One, RHS, and Zero.

Referenced by computeForAddSub(), and llvm::SelectionDAG::computeKnownBits().

◆ computeForAddSub()

KnownBits KnownBits::computeForAddSub	(	bool	Add,
		bool	NSW,
		bool	NUW,
		const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits resulting from adding LHS and RHS.

Definition at line 51 of file KnownBits.cpp.

References llvm::Add, llvm::BitWidth, computeForAddCarry(), llvm::APInt::countl_one(), llvm::APInt::countl_zero(), hasConflict(), llvm::APInt::isNegative(), llvm::APInt::isNonNegative(), LHS, One, RHS, setAllZero(), llvm::APInt::setBits(), llvm::APInt::setHighBits(), llvm::APInt::setSignBit(), std::swap(), llvm::APInt::trunc(), and Zero.

Referenced by abds(), abdu(), abs(), add(), computeForSatAddSub(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsAddSub(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), llvm::TargetLowering::SimplifyDemandedBits(), and sub().

◆ computeForSubBorrow()

KnownBits KnownBits::computeForSubBorrow	(	const KnownBits &	LHS,
		KnownBits	RHS,
		const KnownBits &	Borrow
	)

static

Compute known bits results from subtracting RHS from LHS with 1-bit Borrow.

Definition at line 137 of file KnownBits.cpp.

References assert(), getBitWidth(), llvm::APInt::getBoolValue(), LHS, One, RHS, std::swap(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits().

◆ concat()

KnownBits llvm::KnownBits::concat ( const KnownBits & Lo ) const

inline

Concatenate the bits from Lo onto the bottom of *this.

This is equivalent to: (this->zext(NewWidth) << Lo.getBitWidth()) | Lo.zext(NewWidth)

Definition at line 222 of file KnownBits.h.

References llvm::APInt::concat(), KnownBits(), llvm::Lo, One, and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ countMaxActiveBits()

unsigned llvm::KnownBits::countMaxActiveBits ( ) const

inline

Returns the maximum number of bits needed to represent all possible unsigned values with these known bits.

This is the inverse of the minimum number of leading zeros.

Definition at line 285 of file KnownBits.h.

References countMinLeadingZeros(), and getBitWidth().

Referenced by combinePMULH(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), detectExtMul(), getPack(), narrowIndex(), llvm::AMDGPUTargetLowering::numBitsUnsigned(), simplifyAndInst(), and simplifyLShrInst().

◆ countMaxLeadingOnes()

unsigned llvm::KnownBits::countMaxLeadingOnes ( ) const

inline

Returns the maximum number of leading one bits possible.

Definition at line 272 of file KnownBits.h.

References llvm::APInt::countl_zero(), and Zero.

◆ countMaxLeadingZeros()

unsigned llvm::KnownBits::countMaxLeadingZeros ( ) const

inline

Returns the maximum number of leading zero bits possible.

Definition at line 269 of file KnownBits.h.

References llvm::APInt::countl_zero(), and One.

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and foldCttzCtlz().

◆ countMaxPopulation()

unsigned llvm::KnownBits::countMaxPopulation ( ) const

inline

Returns the maximum number of bits that could be one.

Definition at line 278 of file KnownBits.h.

References getBitWidth(), llvm::APInt::popcount(), and Zero.

Referenced by abs(), combineMOVMSK(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), foldCtpop(), llvm::InstCombinerImpl::foldICmpWithZero(), llvm::isKnownToBeAPowerOfTwo(), and llvm::TargetLowering::SimplifySetCC().

◆ countMaxSignificantBits()

unsigned llvm::KnownBits::countMaxSignificantBits ( ) const

inline

Returns the maximum number of bits needed to represent all possible signed values with these known bits.

This is the inverse of the minimum number of known sign bits. Examples for bitwidth 5: 110?? --> 4 0000? --> 2

Definition at line 258 of file KnownBits.h.

References countMinSignBits(), and getBitWidth().

Referenced by llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode().

◆ countMaxTrailingOnes()

unsigned llvm::KnownBits::countMaxTrailingOnes ( ) const

inline

Returns the maximum number of trailing one bits possible.

Definition at line 266 of file KnownBits.h.

References llvm::APInt::countr_zero(), and Zero.

◆ countMaxTrailingZeros()

unsigned llvm::KnownBits::countMaxTrailingZeros ( ) const

inline

Returns the maximum number of trailing zero bits possible.

Definition at line 263 of file KnownBits.h.

References llvm::APInt::countr_zero(), and One.

Referenced by abs(), blsi(), blsmsk(), llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), foldCttzCtlz(), llvm::InstCombinerImpl::foldICmpBinOp(), llvm::InstCombinerImpl::foldICmpWithZero(), getKnownBitsFromAndXorOr(), isNonZeroMul(), and simplifyDiv().

◆ countMinLeadingOnes()

unsigned llvm::KnownBits::countMinLeadingOnes ( ) const

inline

Returns the minimum number of leading one bits.

Definition at line 240 of file KnownBits.h.

References llvm::APInt::countl_one(), and One.

Referenced by computeKnownBitsFromOperator(), countMinSignBits(), llvm::GCNTTIImpl::rewriteIntrinsicWithAddressSpace(), and llvm::InstCombinerImpl::visitSwitchInst().

◆ countMinLeadingZeros()

unsigned llvm::KnownBits::countMinLeadingZeros ( ) const

inline

Returns the minimum number of leading zero bits.

Definition at line 237 of file KnownBits.h.

References llvm::APInt::countl_one(), and Zero.

Referenced by abs(), llvm::TargetLowering::BuildUDIV(), llvm::CombinerHelper::buildUDivUsingMul(), checkDot4MulSignedness(), combineMOVMSK(), combineScalarToVector(), combineShiftToAVG(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), countMaxActiveBits(), countMinSignBits(), llvm::TargetLowering::expandAVG(), llvm::TargetLowering::expandFixedPointDiv(), foldCttzCtlz(), llvm::InstCombinerImpl::foldICmpAndConstConst(), foldShiftIntoShiftInAnotherHandOfAndInICmp(), llvm::RegsForValue::getCopyFromRegs(), isKnownExactCastIntToFP(), LowerAndToBT(), LowerCTPOP(), llvm::SITargetLowering::lowerSET_ROUNDING(), lowerShuffleWithVPMOV(), matchBinaryShuffle(), llvm::CombinerHelper::matchCombineZextTrunc(), matchTruncateWithPACK(), llvm::AMDGPUTargetLowering::performShlCombine(), llvm::X86TargetLowering::ReplaceNodeResults(), setShiftFlags(), llvm::TargetLowering::SimplifyDemandedBits(), simplifyDivRem(), llvm::InstCombinerImpl::visitCallInst(), and llvm::InstCombinerImpl::visitSwitchInst().

◆ countMinPopulation()

unsigned llvm::KnownBits::countMinPopulation ( ) const

inline

Returns the number of bits known to be one.

Definition at line 275 of file KnownBits.h.

References One, and llvm::APInt::popcount().

Referenced by abs(), foldCtpop(), foldCtpopPow2Test(), llvm::InstCombinerImpl::foldICmpWithZero(), llvm::isKnownToBeAPowerOfTwo(), and llvm::TargetLowering::SimplifySetCC().

◆ countMinSignBits()

unsigned llvm::KnownBits::countMinSignBits ( ) const

inline

Returns the number of times the sign bit is replicated into the other bits.

Definition at line 244 of file KnownBits.h.

References countMinLeadingOnes(), countMinLeadingZeros(), isNegative(), and isNonNegative().

Referenced by llvm::SelectionDAG::ComputeNumSignBits(), ComputeNumSignBitsImpl(), countMaxSignificantBits(), setShiftFlags(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ countMinTrailingOnes()

unsigned llvm::KnownBits::countMinTrailingOnes ( ) const

inline

Returns the minimum number of trailing one bits.

Definition at line 234 of file KnownBits.h.

References llvm::APInt::countr_one(), and One.

Referenced by getKnownBitsFromAndXorOr().

◆ countMinTrailingZeros()

unsigned llvm::KnownBits::countMinTrailingZeros ( ) const

inline

◆ dump()

void KnownBits::dump ( ) const

Definition at line 1144 of file KnownBits.cpp.

References llvm::dbgs(), and print().

◆ eq()

std::optional< bool > KnownBits::eq	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_EQ result.

Definition at line 488 of file KnownBits.cpp.

References LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), and ne().

◆ extractBits()

KnownBits llvm::KnownBits::extractBits	(	unsigned	NumBits,
		unsigned	BitPosition
	)		const

inline

Return a subset of the known bits from [bitPosition,bitPosition+numBits).

Definition at line 214 of file KnownBits.h.

References llvm::APInt::extractBits(), KnownBits(), One, and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), llvm::GISelKnownBits::computeKnownBitsImpl(), mulhs(), mulhu(), and llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode().

◆ getBitWidth()

unsigned llvm::KnownBits::getBitWidth ( ) const

inline

Get the bit width of this value.

Definition at line 40 of file KnownBits.h.

References assert(), llvm::APInt::getBitWidth(), One, and Zero.

Referenced by abs(), llvm::adjustKnownBitsForSelectArm(), anyextOrTrunc(), blsi(), blsmsk(), combineFMulcFCMulc(), computeForAddCarry(), computeForSatAddSub(), computeForSubBorrow(), computeKnownBits(), llvm::SelectionDAG::computeKnownBits(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::LanaiTargetLowering::computeKnownBitsForTargetNode(), llvm::SystemZTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromCmp(), computeKnownBitsFromCond(), llvm::computeKnownBitsFromContext(), computeKnownBitsFromICmpCond(), computeKnownBitsFromOperator(), llvm::computeKnownBitsFromRangeMetadata(), computeKnownBitsFromShiftOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), countMaxActiveBits(), countMaxPopulation(), countMaxSignificantBits(), eliminateDeadSwitchCases(), foldShiftIntoShiftInAnotherHandOfAndInICmp(), llvm::ConstantRange::fromKnownBits(), getKnownBitsFromAndXorOr(), llvm::FunctionLoweringInfo::GetLiveOutRegInfo(), llvm::getOrEnforceKnownAlignment(), inferAlignment(), isConstant(), llvm::SelectionDAG::isKnownNeverZero(), isNonZeroShift(), LowerCTPOP(), makeGE(), print(), setShiftFlags(), sextInReg(), sextOrTrunc(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::InstCombinerImpl::SimplifyDemandedInstructionBits(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), simplifyDivRem(), simplifyShift(), smax(), smin(), tryBitfieldInsertOpFromOr(), llvm::InstCombinerImpl::visitCallInst(), llvm::InstCombinerImpl::visitSwitchInst(), zext(), and zextOrTrunc().

◆ getConstant()

const APInt & llvm::KnownBits::getConstant ( ) const

inline

Returns the value when all bits have a known value.

This just returns One with a protective assertion.

Definition at line 56 of file KnownBits.h.

References assert(), isConstant(), and One.

Referenced by combineFMulcFCMulc(), computeKnownBitsFromOperator(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), LowerVectorAllEqual(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and tryFoldHelper().

◆ getMaxValue()

APInt llvm::KnownBits::getMaxValue ( ) const

inline

◆ getMinValue()

APInt llvm::KnownBits::getMinValue ( ) const

inline

Return the minimal unsigned value possible given these KnownBits.

Definition at line 118 of file KnownBits.h.

References One.

Referenced by extractBits(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), llvm::ConstantRange::fromKnownBits(), simplifyShift(), and simplifyX86immShift().

◆ getSignedMaxValue()

APInt llvm::KnownBits::getSignedMaxValue ( ) const

inline

Return the maximal signed value possible given these KnownBits.

Definition at line 140 of file KnownBits.h.

References llvm::APInt::isSignBitClear(), and One.

Referenced by llvm::InstCombinerImpl::foldICmpUsingKnownBits().

◆ getSignedMinValue()

APInt llvm::KnownBits::getSignedMinValue ( ) const

inline

Return the minimal signed value possible given these KnownBits.

Definition at line 124 of file KnownBits.h.

References llvm::APInt::isSignBitClear(), One, llvm::APInt::setSignBit(), and Zero.

Referenced by cannotBeIntMin(), and llvm::InstCombinerImpl::foldICmpUsingKnownBits().

◆ hasConflict()

bool llvm::KnownBits::hasConflict ( ) const

inline

Returns true if there is conflicting information.

Definition at line 47 of file KnownBits.h.

References llvm::APInt::intersects(), One, and Zero.

Referenced by llvm::adjustKnownBitsForSelectArm(), ashr(), computeForAddSub(), computeKnownBits(), llvm::computeKnownBitsFromContext(), computeKnownBitsFromOperator(), divComputeLowBit(), llvm::ConstantRange::fromKnownBits(), lshr(), shl(), and simplifyShift().

◆ haveNoCommonBitsSet()

static bool llvm::KnownBits::haveNoCommonBitsSet	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

inlinestatic

Return true if LHS and RHS have no common bits set.

Definition at line 315 of file KnownBits.h.

References LHS, and RHS.

Referenced by llvm::haveNoCommonBitsSet(), and llvm::SelectionDAG::haveNoCommonBitsSet().

◆ insertBits()

void llvm::KnownBits::insertBits	(	const KnownBits &	SubBits,
		unsigned	BitPosition
	)

inline

Insert the bits from a smaller known bits starting at bitPosition.

Definition at line 208 of file KnownBits.h.

References llvm::APInt::insertBits(), One, and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), and llvm::GISelKnownBits::computeKnownBitsImpl().

◆ intersectWith()

KnownBits llvm::KnownBits::intersectWith ( const KnownBits & RHS ) const

inline

Returns KnownBits information that is known to be true for both this and RHS.

When an operation is known to return one of its operands, this can be used to combine information about the known bits of the operands to get the information that must be true about the result.

Definition at line 300 of file KnownBits.h.

References KnownBits(), One, RHS, and Zero.

Referenced by abds(), abdu(), ashr(), combineSetCC(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsBinOp(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::LanaiTargetLowering::computeKnownBitsForTargetNode(), llvm::SparcTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromCond(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::FunctionLoweringInfo::ComputePHILiveOutRegInfo(), lshr(), shl(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

◆ isAllOnes()

bool llvm::KnownBits::isAllOnes ( ) const

inline

Returns true if value is all one bits.

Definition at line 79 of file KnownBits.h.

References llvm::APInt::isAllOnes(), and One.

Referenced by isTruncateOf(), matchBinaryShuffle(), and llvm::InstCombinerImpl::visitCallInst().

◆ isConstant()

bool llvm::KnownBits::isConstant ( ) const

inline

Returns true if we know the value of all bits.

Definition at line 50 of file KnownBits.h.

References getBitWidth(), One, llvm::APInt::popcount(), and Zero.

Referenced by llvm::adjustKnownBitsForSelectArm(), combineFMulcFCMulc(), combineScalarToVector(), computeKnownBitsFromOperator(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), getConstant(), LowerVectorAllEqual(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and tryFoldHelper().

◆ isNegative()

bool llvm::KnownBits::isNegative ( ) const

inline

◆ isNonNegative()

bool llvm::KnownBits::isNonNegative ( ) const

inline

Returns true if this value is known to be non-negative.

Definition at line 97 of file KnownBits.h.

References llvm::APInt::isSignBitSet(), and Zero.

Referenced by abs(), canReplaceGEPIdxWithZero(), computeForSatAddSub(), llvm::SelectionDAG::computeKnownBits(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), computeKnownBitsMul(), llvm::GISelKnownBits::computeNumSignBits(), llvm::SelectionDAG::ComputeNumSignBits(), ComputeNumSignBitsImpl(), computeOverflowForSignedAdd(), llvm::computeOverflowForSignedMul(), llvm::SelectionDAG::computeOverflowForSignedMul(), llvm::computeOverflowForUnsignedMul(), countMinSignBits(), llvm::TargetLowering::expandAddSubSat(), foldICmpAndXX(), llvm::ConstantRange::fromKnownBits(), getKnownSign(), getSign32(), isKnownNonZeroFromOperator(), llvm::isKnownPositive(), isNonZeroAdd(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), simplifyICmpWithBinOpOnLHS(), simplifyICmpWithZero(), llvm::X86TargetLowering::SimplifyMultipleUseDemandedBitsForTargetNode(), llvm::InstCombinerImpl::simplifyRangeCheck(), and llvm::InstCombinerImpl::visitSDiv().

◆ isNonZero()

bool llvm::KnownBits::isNonZero ( ) const

inline

Returns true if this value is known to be non-zero.

Definition at line 100 of file KnownBits.h.

References llvm::APInt::isZero(), and One.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromShiftOperator(), computeKnownBitsMul(), llvm::SelectionDAG::isKnownNeverZero(), isKnownNonZeroFromOperator(), llvm::isKnownPositive(), isNonZeroAdd(), isNonZeroMul(), and llvm::InstCombinerImpl::visitCallInst().

◆ isSignUnknown()

bool llvm::KnownBits::isSignUnknown ( ) const

inline

Returns true if we don't know the sign bit.

Definition at line 65 of file KnownBits.h.

References llvm::APInt::isSignBitSet(), One, and Zero.

◆ isStrictlyPositive()

bool llvm::KnownBits::isStrictlyPositive ( ) const

inline

Returns true if this value is known to be positive.

Definition at line 103 of file KnownBits.h.

References llvm::APInt::isSignBitSet(), llvm::APInt::isZero(), One, and Zero.

Referenced by llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), and llvm::SelectionDAG::isKnownNeverZero().

◆ isUnknown()

bool llvm::KnownBits::isUnknown ( ) const

inline

Returns true if we don't know any bits.

Definition at line 62 of file KnownBits.h.

References llvm::APInt::isZero(), One, and Zero.

Referenced by llvm::FunctionLoweringInfo::AddLiveOutRegInfo(), llvm::adjustKnownBitsForSelectArm(), ashr(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsAddSub(), llvm::SITargetLowering::computeKnownBitsForTargetInstr(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::ConstantRange::fromKnownBits(), isKnownNonEqual(), isKnownNonZeroFromOperator(), isNonZeroShift(), lshr(), llvm::CombinerHelper::matchRedundantAnd(), shl(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ isZero()

bool llvm::KnownBits::isZero ( ) const

inline

Returns true if value is all zero.

Definition at line 76 of file KnownBits.h.

References llvm::APInt::isAllOnes(), and Zero.

Referenced by llvm::AMDGPULegalizerInfo::buildMultiply(), combineMOVMSK(), combineX86ShufflesRecursively(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), isZero(), LowerVectorAllEqual(), llvm::SelectionDAG::MaskedVectorIsZero(), matchBinaryShuffle(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), simplifyDivRem(), and simplifyX86immShift().

◆ lshr()

KnownBits KnownBits::lshr	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	ShAmtNonZero = `false`,
		bool	Exact = `false`
	)

static

Compute known bits for lshr(LHS, RHS).

NOTE: RHS (shift amount) bitwidth doesn't need to be the same as LHS.

Definition at line 370 of file KnownBits.cpp.

References llvm::BitWidth, getMaxShiftAmount(), hasConflict(), intersectWith(), isUnknown(), LHS, llvm::APInt::lshrInPlace(), One, RHS, llvm::APInt::setAllBits(), setAllZero(), llvm::APInt::setHighBits(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and extractBits().

◆ makeConstant()

static KnownBits llvm::KnownBits::makeConstant ( const APInt & C )

inlinestatic

◆ makeGE()

KnownBits KnownBits::makeGE ( const APInt & Val ) const

Return KnownBits based on this, but updated given that the underlying value is known to be greater than or equal to Val.

Definition at line 166 of file KnownBits.cpp.

References llvm::APInt::clearLowBits(), llvm::countl_one(), getBitWidth(), KnownBits(), N, One, and Zero.

◆ makeNegative()

void llvm::KnownBits::makeNegative ( )

inline

Make this value negative.

Definition at line 108 of file KnownBits.h.

References One, and llvm::APInt::setSignBit().

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromCmp(), computeKnownBitsFromOperator(), computeKnownBitsMul(), shl(), and unaryOpKnownBitsMapHelper().

◆ makeNonNegative()

void llvm::KnownBits::makeNonNegative ( )

inline

Make this value non-negative.

Definition at line 113 of file KnownBits.h.

References llvm::APInt::setSignBit(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromCmp(), computeKnownBitsFromOperator(), computeKnownBitsMul(), shl(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), and unaryOpKnownBitsMapHelper().

◆ mul()

KnownBits KnownBits::mul	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	NoUndefSelfMultiply = `false`
	)

static

Compute known bits resulting from multiplying LHS and RHS.

Definition at line 797 of file KnownBits.cpp.

References assert(), llvm::BitWidth, llvm::APInt::countl_zero(), llvm::countr_one(), llvm::APInt::getLoBits(), LHS, One, RHS, llvm::APInt::setBit(), llvm::APInt::setHighBits(), llvm::APInt::umul_ov(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsForPMADDUBSW(), computeKnownBitsForPMADDWD(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), computeKnownBitsMul(), mulhs(), mulhu(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ mulhs()

KnownBits KnownBits::mulhs	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits from sign-extended multiply-hi.

Definition at line 894 of file KnownBits.cpp.

References assert(), llvm::BitWidth, extractBits(), LHS, mul(), and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsFromOperator().

◆ mulhu()

KnownBits KnownBits::mulhu	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits from zero-extended multiply-hi.

Definition at line 902 of file KnownBits.cpp.

References assert(), llvm::BitWidth, extractBits(), LHS, mul(), and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsFromOperator().

◆ ne()

std::optional< bool > KnownBits::ne	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_NE result.

Definition at line 496 of file KnownBits.cpp.

References eq(), LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::isKnownNeverZero(), and llvm::CombinerHelper::matchICmpToTrueFalseKnownBits().

◆ operator!=()

bool llvm::KnownBits::operator!= ( const KnownBits & Other ) const

inline

Definition at line 488 of file KnownBits.h.

References llvm::Other.

◆ operator&=()

KnownBits & KnownBits::operator&= ( const KnownBits & RHS )

Update known bits based on ANDing with RHS.

Definition at line 1084 of file KnownBits.cpp.

References One, RHS, and Zero.

◆ operator==()

bool llvm::KnownBits::operator== ( const KnownBits & Other ) const

inline

Definition at line 484 of file KnownBits.h.

References One, llvm::Other, and Zero.

◆ operator^=()

KnownBits & KnownBits::operator^= ( const KnownBits & RHS )

Update known bits based on XORing with RHS.

Definition at line 1100 of file KnownBits.cpp.

References One, RHS, and Zero.

◆ operator|=()

KnownBits & KnownBits::operator|= ( const KnownBits & RHS )

Update known bits based on ORing with RHS.

Definition at line 1092 of file KnownBits.cpp.

References One, RHS, and Zero.

◆ print()

void KnownBits::print ( raw_ostream & OS ) const

Definition at line 1130 of file KnownBits.cpp.

References llvm::BitWidth, getBitWidth(), I, N, One, OS, and Zero.

Referenced by dump(), and llvm::operator<<().

◆ resetAll()

void llvm::KnownBits::resetAll ( )

inline

Resets the known state of all bits.

Definition at line 70 of file KnownBits.h.

References llvm::APInt::clearAllBits(), One, and Zero.

◆ reverseBits()

KnownBits llvm::KnownBits::reverseBits ( ) const

inline

Definition at line 472 of file KnownBits.h.

References KnownBits(), One, llvm::APInt::reverseBits(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), and llvm::GISelKnownBits::computeKnownBitsImpl().

◆ sadd_sat()

KnownBits KnownBits::sadd_sat	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from llvm.sadd.sat(LHS, RHS)

Definition at line 753 of file KnownBits.cpp.

References computeForSatAddSub(), LHS, and RHS.

Referenced by computeKnownBitsForPMADDUBSW(), and computeKnownBitsFromOperator().

◆ sdiv()

KnownBits KnownBits::sdiv	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	Exact = `false`
	)

static

Compute known bits for sdiv(LHS, RHS).

Definition at line 946 of file KnownBits.cpp.

References llvm::BitWidth, llvm::APInt::countLeadingZeros(), divComputeLowBit(), llvm::APInt::getSignedMaxValue(), llvm::APInt::isAllOnes(), llvm::APInt::isMinSignedValue(), llvm::APInt::isZero(), LHS, One, RHS, llvm::APInt::sdiv(), setAllZero(), llvm::APInt::setHighBits(), udiv(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsFromOperator().

◆ setAllOnes()

void llvm::KnownBits::setAllOnes ( )

inline

Make all bits known to be one and discard any previous information.

Definition at line 88 of file KnownBits.h.

References llvm::APInt::clearAllBits(), One, llvm::APInt::setAllBits(), and Zero.

Referenced by llvm::X86TargetLowering::computeKnownBitsForTargetNode(), and llvm::computeKnownBitsFromContext().

◆ setAllZero()

void llvm::KnownBits::setAllZero ( )

inline

Make all bits known to be zero and discard any previous information.

Definition at line 82 of file KnownBits.h.

References llvm::APInt::clearAllBits(), One, llvm::APInt::setAllBits(), and Zero.

Referenced by ashr(), computeForAddSub(), computeKnownBits(), llvm::SelectionDAG::computeKnownBits(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromCmp(), llvm::computeKnownBitsFromContext(), divComputeLowBit(), lshr(), sdiv(), shl(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and udiv().

◆ sext()

KnownBits llvm::KnownBits::sext ( unsigned BitWidth ) const

inline

Return known bits for a sign extension of the value we're tracking.

Definition at line 169 of file KnownBits.h.

References llvm::BitWidth, KnownBits(), One, llvm::APInt::sext(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsForPMADDUBSW(), computeKnownBitsForPMADDWD(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::SystemZTargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), sextOrTrunc(), llvm::TargetLowering::SimplifyDemandedBits(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

◆ sextInReg()

KnownBits KnownBits::sextInReg ( unsigned SrcBitWidth ) const

Return known bits for a in-register sign extension of the value we're tracking.

Definition at line 149 of file KnownBits.cpp.

References assert(), llvm::BitWidth, getBitWidth(), One, and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), and llvm::GISelKnownBits::computeKnownBitsImpl().

◆ sextOrTrunc()

KnownBits llvm::KnownBits::sextOrTrunc ( unsigned BitWidth ) const

inline

Return known bits for a sign extension or truncation of the value we're tracking.

Definition at line 195 of file KnownBits.h.

References llvm::BitWidth, getBitWidth(), sext(), and trunc().

Referenced by computeKnownBitsFromOperator().

◆ sge()

std::optional< bool > KnownBits::sge	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_SGE result.

Definition at line 536 of file KnownBits.cpp.

References LHS, RHS, and sgt().

Referenced by binaryOpKnownBitsMapHelper(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), llvm::TargetLowering::SimplifyDemandedBits(), and sle().

◆ sgt()

std::optional< bool > KnownBits::sgt	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_SGT result.

Definition at line 526 of file KnownBits.cpp.

References LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), sge(), llvm::TargetLowering::SimplifyDemandedBits(), and slt().

◆ shl()

KnownBits KnownBits::shl	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	NUW = `false`,
		bool	NSW = `false`,
		bool	ShAmtNonZero = `false`
	)

static

Compute known bits for shl(LHS, RHS).

NOTE: RHS (shift amount) bitwidth doesn't need to be the same as LHS.

Definition at line 285 of file KnownBits.cpp.

References llvm::BitWidth, getMaxShiftAmount(), hasConflict(), intersectWith(), llvm::isPowerOf2_32(), isUnknown(), LHS, makeNegative(), makeNonNegative(), One, RHS, llvm::APInt::setAllBits(), setAllZero(), llvm::APInt::setLowBits(), llvm::APInt::setSignBit(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), and simplifyShift().

◆ sle()

std::optional< bool > KnownBits::sle	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_SLE result.

Definition at line 546 of file KnownBits.cpp.

References LHS, RHS, and sge().

Referenced by binaryOpKnownBitsMapHelper(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ slt()

std::optional< bool > KnownBits::slt	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_SLT result.

Definition at line 542 of file KnownBits.cpp.

References LHS, RHS, and sgt().

Referenced by binaryOpKnownBitsMapHelper(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ smax()

KnownBits KnownBits::smax	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for smax(LHS, RHS).

Definition at line 202 of file KnownBits.cpp.

References getBitWidth(), KnownBits(), LHS, One, RHS, llvm::APInt::setBitVal(), umax(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ smin()

KnownBits KnownBits::smin	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for smin(LHS, RHS).

Definition at line 215 of file KnownBits.cpp.

References getBitWidth(), KnownBits(), LHS, One, RHS, llvm::APInt::setBitVal(), umax(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ srem()

KnownBits KnownBits::srem	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for srem(LHS, RHS).

Definition at line 1059 of file KnownBits.cpp.

References llvm::APInt::intersects(), llvm::APInt::isSubsetOf(), LHS, One, RHS, llvm::APInt::setHighBits(), and Zero.

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsFromOperator().

◆ ssub_sat()

KnownBits KnownBits::ssub_sat	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from llvm.ssub.sat(LHS, RHS)

Definition at line 756 of file KnownBits.cpp.

References computeForSatAddSub(), LHS, and RHS.

Referenced by computeKnownBitsFromOperator().

◆ sub()

static KnownBits llvm::KnownBits::sub	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	NSW = `false`,
		bool	NUW = `false`
	)

inlinestatic

Compute knownbits resulting from subtraction of LHS and RHS.

Definition at line 339 of file KnownBits.h.

References computeForAddSub(), LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), and llvm::InstCombinerImpl::SimplifyMultipleUseDemandedBits().

◆ trunc()

KnownBits llvm::KnownBits::trunc ( unsigned BitWidth ) const

inline

Return known bits for a truncation of the value we're tracking.

Definition at line 150 of file KnownBits.h.

References llvm::BitWidth, KnownBits(), One, llvm::APInt::trunc(), and Zero.

Referenced by anyextOrTrunc(), llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), sextOrTrunc(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and zextOrTrunc().

◆ uadd_sat()

KnownBits KnownBits::uadd_sat	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from llvm.uadd.sat(LHS, RHS)

Definition at line 759 of file KnownBits.cpp.

References computeForSatAddSub(), LHS, and RHS.

Referenced by computeKnownBitsFromOperator().

◆ udiv()

KnownBits KnownBits::udiv	(	const KnownBits &	LHS,
		const KnownBits &	RHS,
		bool	Exact = `false`
	)

static

Compute known bits for udiv(LHS, RHS).

Definition at line 1002 of file KnownBits.cpp.

References llvm::BitWidth, llvm::APInt::countLeadingZeros(), divComputeLowBit(), llvm::APInt::isZero(), LHS, RHS, setAllZero(), llvm::APInt::setHighBits(), llvm::APInt::udiv(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), sdiv(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

◆ uge()

std::optional< bool > KnownBits::uge	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_UGE result.

Definition at line 512 of file KnownBits.cpp.

References LHS, RHS, and ugt().

Referenced by isKnownNonZeroFromOperator(), llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), llvm::TargetLowering::SimplifyDemandedBits(), and ule().

◆ ugt()

std::optional< bool > KnownBits::ugt	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_UGT result.

Definition at line 502 of file KnownBits.cpp.

References LHS, and RHS.

Referenced by llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), llvm::TargetLowering::SimplifyDemandedBits(), uge(), and ult().

◆ ule()

std::optional< bool > KnownBits::ule	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_ULE result.

Definition at line 522 of file KnownBits.cpp.

References LHS, RHS, and uge().

Referenced by llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ ult()

std::optional< bool > KnownBits::ult	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Determine if these known bits always give the same ICMP_ULT result.

Definition at line 518 of file KnownBits.cpp.

References LHS, RHS, and ugt().

Referenced by llvm::CombinerHelper::matchICmpToTrueFalseKnownBits(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ umax()

KnownBits KnownBits::umax	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for umax(LHS, RHS).

Definition at line 178 of file KnownBits.cpp.

References LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::TargetLowering::SimplifyDemandedBits(), smax(), smin(), targetOpKnownBitsMapHelper(), and umin().

◆ umin()

KnownBits KnownBits::umin	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for umin(LHS, RHS).

Definition at line 196 of file KnownBits.cpp.

References KnownBits(), LHS, RHS, and umax().

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ unionWith()

KnownBits llvm::KnownBits::unionWith ( const KnownBits & RHS ) const

inline

Returns KnownBits information that is known to be true for either this or RHS or both.

This can be used to combine different sources of information about the known bits of a single value, e.g. information about the low bits and the high bits of the result of a multiplication.

Definition at line 310 of file KnownBits.h.

References KnownBits(), One, RHS, and Zero.

Referenced by llvm::adjustKnownBitsForSelectArm(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromCmp(), computeKnownBitsFromCond(), computeKnownBitsFromICmpCond(), computeKnownBitsFromOperator(), and llvm::TargetLowering::SimplifyDemandedBits().

◆ urem()

KnownBits KnownBits::urem	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute known bits for urem(LHS, RHS).

Definition at line 1042 of file KnownBits.cpp.

References LHS, RHS, llvm::APInt::setHighBits(), and Zero.

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), and computeKnownBitsFromOperator().

◆ usub_sat()

KnownBits KnownBits::usub_sat	(	const KnownBits &	LHS,
		const KnownBits &	RHS
	)

static

Compute knownbits resulting from llvm.usub.sat(LHS, RHS)

Definition at line 762 of file KnownBits.cpp.

References computeForSatAddSub(), LHS, and RHS.

Referenced by llvm::SelectionDAG::computeKnownBits(), and computeKnownBitsFromOperator().

◆ zext()

KnownBits llvm::KnownBits::zext ( unsigned BitWidth ) const

inline

Return known bits for a zero extension of the value we're tracking.

Definition at line 161 of file KnownBits.h.

References llvm::BitWidth, getBitWidth(), KnownBits(), One, llvm::APInt::setBitsFrom(), Zero, and llvm::APInt::zext().

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsForPMADDUBSW(), computeKnownBitsForPSADBW(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::SystemZTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), llvm::GISelKnownBits::computeKnownBitsImpl(), fromOptionalToKnownBits(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and zextOrTrunc().

◆ zextOrTrunc()

KnownBits llvm::KnownBits::zextOrTrunc ( unsigned BitWidth ) const

inline

Return known bits for a zero extension or truncation of the value we're tracking.

Definition at line 185 of file KnownBits.h.

References llvm::BitWidth, getBitWidth(), trunc(), and zext().

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelKnownBits::computeKnownBitsImpl(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

Member Data Documentation

◆ One

APInt llvm::KnownBits::One

Definition at line 25 of file KnownBits.h.

◆ Zero

APInt llvm::KnownBits::Zero

Definition at line 24 of file KnownBits.h.

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

include/llvm/Support/KnownBits.h
lib/Support/KnownBits.cpp

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ KnownBits() [1/2]

◆ KnownBits() [2/2]

Member Function Documentation

◆ abds()

◆ abdu()

◆ abs()

◆ add()

◆ anyext()

◆ anyextOrTrunc()

◆ ashr()

◆ avgCeilS()

◆ avgCeilU()

◆ avgFloorS()

◆ avgFloorU()

◆ blsi()

◆ blsmsk()

◆ byteSwap()

◆ computeForAddCarry()

◆ computeForAddSub()

◆ computeForSubBorrow()

◆ concat()

◆ countMaxActiveBits()

◆ countMaxLeadingOnes()

◆ countMaxLeadingZeros()

◆ countMaxPopulation()

◆ countMaxSignificantBits()

◆ countMaxTrailingOnes()

◆ countMaxTrailingZeros()

◆ countMinLeadingOnes()

◆ countMinLeadingZeros()

◆ countMinPopulation()

◆ countMinSignBits()

◆ countMinTrailingOnes()

◆ countMinTrailingZeros()

◆ dump()

◆ eq()

◆ extractBits()

◆ getBitWidth()

◆ getConstant()

◆ getMaxValue()

◆ getMinValue()

◆ getSignedMaxValue()

◆ getSignedMinValue()

◆ hasConflict()

◆ haveNoCommonBitsSet()

◆ insertBits()

◆ intersectWith()

◆ isAllOnes()

◆ isConstant()

◆ isNegative()

◆ isNonNegative()

◆ isNonZero()

◆ isSignUnknown()

◆ isStrictlyPositive()

◆ isUnknown()

◆ isZero()

◆ lshr()

◆ makeConstant()

◆ makeGE()

◆ makeNegative()

◆ makeNonNegative()

◆ mul()

◆ mulhs()

◆ mulhu()

◆ ne()

◆ operator!=()

◆ operator&=()

◆ operator==()

◆ operator^=()

◆ operator|=()

◆ print()

◆ resetAll()

◆ reverseBits()

◆ sadd_sat()

◆ sdiv()