LLVM: llvm::KnownBits Struct Reference (original) (raw)

#include "[llvm/Support/KnownBits.h](KnownBits%5F8h%5Fsource.html)"

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.
void	setAllConflict ()
	Make all bits known to be both zero and one.
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.
LLVM_ABI 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.
LLVM_ABI 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.
LLVM_ABI KnownBits &	operator&= (const KnownBits &RHS)
	Update known bits based on ANDing with RHS.
LLVM_ABI KnownBits &	operator\|= (const KnownBits &RHS)
	Update known bits based on ORing with RHS.
LLVM_ABI KnownBits &	operator^= (const KnownBits &RHS)
	Update known bits based on XORing with RHS.
KnownBits &	operator<<= (unsigned ShAmt)
	Shift known bits left by ShAmt. Shift in bits are unknown.
KnownBits &	operator>>= (unsigned ShAmt)
	Shift known bits right by ShAmt. Shifted in bits are unknown.
LLVM_ABI KnownBits	abs (bool IntMinIsPoison=false) const
	Compute known bits for the absolute value.
KnownBits	byteSwap () const
KnownBits	reverseBits () const
LLVM_ABI KnownBits	blsi () const
	Compute known bits for X & -X, which has only the lowest bit set of X set.
LLVM_ABI 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
LLVM_ABI void	print (raw_ostream &OS) const
LLVM_DUMP_METHOD 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 LLVM_ABI 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 LLVM_ABI KnownBits	computeForAddSub (bool Add, bool NSW, bool NUW, const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits resulting from adding LHS and RHS.
static LLVM_ABI 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 LLVM_ABI KnownBits	sadd_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.sadd.sat(LHS, RHS)
static LLVM_ABI KnownBits	uadd_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.uadd.sat(LHS, RHS)
static LLVM_ABI KnownBits	ssub_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.ssub.sat(LHS, RHS)
static LLVM_ABI KnownBits	usub_sat (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from llvm.usub.sat(LHS, RHS)
static LLVM_ABI KnownBits	avgFloorS (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgFloorS.
static LLVM_ABI KnownBits	avgFloorU (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgFloorU.
static LLVM_ABI KnownBits	avgCeilS (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgCeilS.
static LLVM_ABI KnownBits	avgCeilU (const KnownBits &LHS, const KnownBits &RHS)
	Compute knownbits resulting from APIntOps::avgCeilU.
static LLVM_ABI KnownBits	mul (const KnownBits &LHS, const KnownBits &RHS, bool NoUndefSelfMultiply=false)
	Compute known bits resulting from multiplying LHS and RHS.
static LLVM_ABI KnownBits	mulhs (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits from sign-extended multiply-hi.
static LLVM_ABI KnownBits	mulhu (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits from zero-extended multiply-hi.
static LLVM_ABI KnownBits	sdiv (const KnownBits &LHS, const KnownBits &RHS, bool Exact=false)
	Compute known bits for sdiv(LHS, RHS).
static LLVM_ABI KnownBits	udiv (const KnownBits &LHS, const KnownBits &RHS, bool Exact=false)
	Compute known bits for udiv(LHS, RHS).
static LLVM_ABI KnownBits	urem (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for urem(LHS, RHS).
static LLVM_ABI KnownBits	srem (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for srem(LHS, RHS).
static LLVM_ABI KnownBits	umax (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for umax(LHS, RHS).
static LLVM_ABI KnownBits	umin (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for umin(LHS, RHS).
static LLVM_ABI KnownBits	smax (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for smax(LHS, RHS).
static LLVM_ABI KnownBits	smin (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for smin(LHS, RHS).
static LLVM_ABI KnownBits	abdu (const KnownBits &LHS, const KnownBits &RHS)
	Compute known bits for abdu(LHS, RHS).
static LLVM_ABI KnownBits	abds (KnownBits LHS, KnownBits RHS)
	Compute known bits for abds(LHS, RHS).
static LLVM_ABI 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 LLVM_ABI KnownBits	lshr (const KnownBits &LHS, const KnownBits &RHS, bool ShAmtNonZero=false, bool Exact=false)
	Compute known bits for lshr(LHS, RHS).
static LLVM_ABI KnownBits	ashr (const KnownBits &LHS, const KnownBits &RHS, bool ShAmtNonZero=false, bool Exact=false)
	Compute known bits for ashr(LHS, RHS).
static LLVM_ABI std::optional< bool >	eq (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_EQ result.
static LLVM_ABI std::optional< bool >	ne (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_NE result.
static LLVM_ABI std::optional< bool >	ugt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_UGT result.
static LLVM_ABI std::optional< bool >	uge (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_UGE result.
static LLVM_ABI std::optional< bool >	ult (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_ULT result.
static LLVM_ABI std::optional< bool >	ule (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_ULE result.
static LLVM_ABI std::optional< bool >	sgt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SGT result.
static LLVM_ABI std::optional< bool >	sge (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SGE result.
static LLVM_ABI std::optional< bool >	slt (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SLT result.
static LLVM_ABI std::optional< bool >	sle (const KnownBits &LHS, const KnownBits &RHS)
	Determine if these known bits always give the same ICMP_SLE result.

Definition at line 24 of file KnownBits.h.

llvm::KnownBits::KnownBits ( )	default

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

◆ KnownBits() [2/2]

llvm::KnownBits::KnownBits ( unsigned BitWidth)	inline

◆ abds()

◆ abdu()

◆ abs()

Compute known bits for the absolute value.

Definition at line 546 of file KnownBits.cpp.

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

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

◆ add()

Compute knownbits resulting from addition of LHS and RHS.

Definition at line 347 of file KnownBits.h.

References computeForAddSub(), LHS, and RHS.

Referenced by binaryOpKnownBitsMapHelper(), computeKnownBitsForPMADDWD(), computeKnownBitsForPSADBW(), llvm::SITargetLowering::computeKnownBitsForTargetInstr(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::SITargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelValueTracking::computeKnownBitsImpl(), isNonZeroAdd(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), and llvm::InstCombinerImpl::SimplifyMultipleUseDemandedBits().

◆ anyext()

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 167 of file KnownBits.h.

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

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

◆ anyextOrTrunc()

◆ ashr()

Compute known bits for ashr(LHS, RHS).

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

Definition at line 425 of file KnownBits.cpp.

References llvm::APInt::ashrInPlace(), llvm::BitWidth, getMaxShiftAmount(), llvm::APInt::getMaxValue(), hasConflict(), intersectWith(), isUnknown(), One, setAllConflict(), setAllZero(), and Zero.

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

◆ avgCeilS()

◆ avgCeilU()

◆ avgFloorS()

◆ avgFloorU()

◆ blsi()

◆ blsmsk()

◆ byteSwap()

KnownBits llvm::KnownBits::byteSwap ( ) const	inline

◆ computeForAddCarry()

◆ computeForAddSub()

Compute known bits resulting from adding LHS and RHS.

Definition at line 60 of file KnownBits.cpp.

References llvm::Add, llvm::BitWidth, computeForAddCarry(), llvm::APInt::countl_one(), llvm::APInt::countl_zero(), llvm::APInt::getMaxValue(), llvm::APInt::getMinValue(), llvm::APInt::getSignedMaxValue(), llvm::APInt::getSignedMinValue(), hasConflict(), llvm::APInt::isNegative(), llvm::APInt::isNonNegative(), One, llvm::APInt::sadd_sat(), setAllZero(), llvm::APInt::setBits(), llvm::APInt::setHighBits(), llvm::APInt::setSignBit(), llvm::APInt::ssub_sat(), std::swap(), llvm::APInt::trunc(), llvm::APInt::uadd_sat(), llvm::APInt::usub_sat(), and Zero.

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

◆ computeForSubBorrow()

◆ concat()

◆ 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 296 of file KnownBits.h.

References countMinLeadingZeros(), and getBitWidth().

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

◆ countMaxLeadingOnes()

unsigned llvm::KnownBits::countMaxLeadingOnes ( ) const	inline

Returns the maximum number of leading one bits possible.

Definition at line 283 of file KnownBits.h.

References Zero.

◆ countMaxLeadingZeros()

unsigned llvm::KnownBits::countMaxLeadingZeros ( ) const	inline

◆ countMaxPopulation()

unsigned llvm::KnownBits::countMaxPopulation ( ) const	inline

◆ countMaxSignificantBits()

unsigned llvm::KnownBits::countMaxSignificantBits ( ) const	inline

◆ countMaxTrailingOnes()

unsigned llvm::KnownBits::countMaxTrailingOnes ( ) const	inline

Returns the maximum number of trailing one bits possible.

Definition at line 277 of file KnownBits.h.

References Zero.

◆ countMaxTrailingZeros()

unsigned llvm::KnownBits::countMaxTrailingZeros ( ) const	inline

Returns the maximum number of trailing zero bits possible.

Definition at line 274 of file KnownBits.h.

References One.

Referenced by abs(), blsi(), blsmsk(), llvm::SelectionDAG::computeKnownBits(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), foldCttzCtlz(), llvm::InstCombinerImpl::foldICmpBinOp(), llvm::InstCombinerImpl::foldICmpWithZero(), getKnownBitsFromAndXorOr(), isNonZeroMul(), and simplifyDiv().

◆ countMinLeadingOnes()

unsigned llvm::KnownBits::countMinLeadingOnes ( ) const	inline

◆ countMinLeadingZeros()

unsigned llvm::KnownBits::countMinLeadingZeros ( ) const	inline

Returns the minimum number of leading zero bits.

Definition at line 248 of file KnownBits.h.

References Zero.

Referenced by abs(), llvm::TargetLowering::BuildUDIV(), checkDot4MulSignedness(), combineMOVMSK(), combineSCALAR_TO_VECTOR(), combineShiftToAVG(), combineVPMADD52LH(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), countMaxActiveBits(), countMinSignBits(), llvm::TargetLowering::expandAVG(), llvm::TargetLowering::expandFixedPointDiv(), foldCttzCtlz(), llvm::InstCombinerImpl::foldICmpAndConstConst(), foldShiftIntoShiftInAnotherHandOfAndInICmp(), llvm::RegsForValue::getCopyFromRegs(), getMinUselessShift(), isKnownExactCastIntToFP(), LowerAndToBT(), LowerCTPOP(), llvm::SITargetLowering::lowerSET_ROUNDING(), lowerShuffleWithVPMOV(), matchBinaryShuffle(), matchTruncateWithPACK(), matchVPMADD52(), narrowBitOpRMW(), 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

◆ countMinSignBits()

unsigned llvm::KnownBits::countMinSignBits ( ) const	inline

◆ countMinTrailingOnes()

unsigned llvm::KnownBits::countMinTrailingOnes ( ) const	inline

◆ countMinTrailingZeros()

unsigned llvm::KnownBits::countMinTrailingZeros ( ) const	inline

Returns the minimum number of trailing zero bits.

Definition at line 242 of file KnownBits.h.

References Zero.

Referenced by abs(), blsi(), blsmsk(), combineTruncate(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::TargetLowering::expandFixedPointDiv(), foldCttzCtlz(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), llvm::X86TTIImpl::getIntImmCostInst(), getMinUselessShift(), llvm::getOrEnforceKnownAlignment(), inferAlignment(), llvm::SelectionDAG::InferPtrAlign(), isKnownExactCastIntToFP(), isMultipleOfN(), isWordAligned(), LowerCTPOP(), llvm::X86TargetLowering::ReplaceNodeResults(), setShiftFlags(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), simplifyShift(), llvm::InstCombinerImpl::visitCallInst(), and llvm::InstCombinerImpl::visitSDiv().

◆ dump()

◆ eq()

◆ extractBits()

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

Definition at line 225 of file KnownBits.h.

References KnownBits(), One, and Zero.

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

◆ getBitWidth()

unsigned llvm::KnownBits::getBitWidth ( ) const	inline

Get the bit width of this value.

Definition at line 44 of file KnownBits.h.

References assert(), One, and Zero.

Referenced by abs(), llvm::adjustKnownBitsForSelectArm(), anyextOrTrunc(), blsi(), blsmsk(), combineFMulcFCMulc(), combinePTESTCC(), computeForAddCarry(), computeForSubBorrow(), computeKnownBits(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsForLoadV(), computeKnownBitsForPRMT(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::LanaiTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::SystemZTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromCmp(), computeKnownBitsFromCond(), llvm::computeKnownBitsFromContext(), computeKnownBitsFromICmpCond(), computeKnownBitsFromOperator(), llvm::computeKnownBitsFromRangeMetadata(), computeKnownBitsFromShiftOperator(), llvm::GISelValueTracking::computeKnownBitsImpl(), computeKnownBitsMul(), countMaxActiveBits(), countMaxPopulation(), countMaxSignificantBits(), eliminateDeadSwitchCases(), foldShiftIntoShiftInAnotherHandOfAndInICmp(), llvm::ConstantRange::fromKnownBits(), getKnownBitsFromAndXorOr(), llvm::FunctionLoweringInfo::GetLiveOutRegInfo(), getMinUselessShift(), llvm::getOrEnforceKnownAlignment(), inferAlignment(), isConstant(), llvm::SelectionDAG::isKnownNeverZero(), isNonZeroShift(), isSignificantBitCheckWellFormed(), LowerCTPOP(), makeGE(), print(), setShiftFlags(), sextInReg(), sextOrTrunc(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::InstCombinerImpl::SimplifyDemandedInstructionBits(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), simplifyDivRem(), simplifyShift(), 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 60 of file KnownBits.h.

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

Referenced by combineFMulcFCMulc(), combineMul(), combinePTESTCC(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), LowerCTPOP(), LowerShift(), LowerVectorAllEqual(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), llvm::GCNTTIImpl::simplifyDemandedLaneMaskArg(), and tryFoldHelper().

◆ getMaxValue()

APInt llvm::KnownBits::getMaxValue ( ) const	inline

Return the maximal unsigned value possible given these KnownBits.

Definition at line 145 of file KnownBits.h.

References Zero.

Referenced by llvm::SelectionDAG::canCreateUndefOrPoison(), combineANDOfSETCCToCZERO(), combineArithReduction(), combineSetCC(), combineTruncate(), computeKnownBitsFromLerpPattern(), computeKnownBitsFromShiftOperator(), llvm::SelectionDAG::computeOverflowForUnsignedAdd(), llvm::InstCombinerImpl::convertOrOfShiftsToFunnelShift(), extractBits(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), foldSwitchToSelect(), llvm::ConstantRange::fromKnownBits(), llvm::GISelValueTracking::getValidShiftAmountRange(), llvm::SelectionDAG::getValidShiftAmountRange(), llvm::SelectionDAG::isKnownNeverZero(), isNonZeroShift(), llvm::CombinerHelper::matchCombineTruncOfShift(), narrowBitOpRMW(), llvm::AMDGPUTargetLowering::performTruncateCombine(), setShiftFlags(), simplifyAndInst(), simplifyShiftSelectingPackedElement(), simplifyX86immShift(), simplifyX86varShift(), and llvm::InstCombinerImpl::visitAnd().

◆ getMinValue()

APInt llvm::KnownBits::getMinValue ( ) const	inline

◆ getSignedMaxValue()

APInt llvm::KnownBits::getSignedMaxValue ( ) const	inline

◆ getSignedMinValue()

APInt llvm::KnownBits::getSignedMinValue ( ) const	inline

◆ hasConflict()

bool llvm::KnownBits::hasConflict ( ) const	inline

Returns true if there is conflicting information.

Definition at line 51 of file KnownBits.h.

References One, and Zero.

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

◆ haveNoCommonBitsSet()

◆ insertBits()

◆ intersectWith()

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 311 of file KnownBits.h.

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

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

◆ isAllOnes()

bool llvm::KnownBits::isAllOnes ( ) const	inline

◆ isConstant()

bool llvm::KnownBits::isConstant ( ) const	inline

Returns true if we know the value of all bits.

Definition at line 54 of file KnownBits.h.

References getBitWidth(), One, and Zero.

Referenced by llvm::adjustKnownBitsForSelectArm(), combineFMulcFCMulc(), combineMul(), combinePTESTCC(), combineSCALAR_TO_VECTOR(), computeKnownBitsFromOperator(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), getConstant(), LowerCTPOP(), LowerShift(), LowerVectorAllEqual(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), llvm::GCNTTIImpl::simplifyDemandedLaneMaskArg(), and tryFoldHelper().

◆ isNegative()

bool llvm::KnownBits::isNegative ( ) const	inline

Returns true if this value is known to be negative.

Definition at line 105 of file KnownBits.h.

References One.

Referenced by abs(), combineSelect(), computeForSatAddSub(), llvm::SelectionDAG::computeKnownBits(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), computeKnownBitsMul(), llvm::GISelValueTracking::computeNumSignBits(), computeOverflowForSignedAdd(), countMinSignBits(), llvm::TargetLowering::expandAddSubSat(), foldICmpAndXX(), llvm::InstCombinerImpl::foldICmpBinOp(), llvm::ConstantRange::fromKnownBits(), getKnownSign(), getMinUselessShift(), getSign32(), llvm::SelectionDAG::isKnownNeverZero(), isKnownNonZeroFromOperator(), isNonZeroAdd(), llvm::AMDGPUTargetLowering::performSraCombine(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), simplifyICmpWithBinOpOnLHS(), simplifyICmpWithZero(), and llvm::X86TargetLowering::SimplifyMultipleUseDemandedBitsForTargetNode().

◆ isNonNegative()

bool llvm::KnownBits::isNonNegative ( ) const	inline

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

Definition at line 108 of file KnownBits.h.

References Zero.

Referenced by abs(), canReplaceGEPIdxWithZero(), combineSelect(), computeForSatAddSub(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsAddSub(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromLerpPattern(), computeKnownBitsFromOperator(), computeKnownBitsMul(), llvm::SelectionDAG::ComputeNumSignBits(), llvm::GISelValueTracking::computeNumSignBits(), ComputeNumSignBitsImpl(), computeOverflowForSignedAdd(), llvm::computeOverflowForSignedMul(), llvm::SelectionDAG::computeOverflowForSignedMul(), llvm::computeOverflowForUnsignedMul(), countMinSignBits(), llvm::TargetLowering::expandAddSubSat(), foldICmpAndXX(), llvm::ConstantRange::fromKnownBits(), getKnownSign(), getMinUselessShift(), 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 111 of file KnownBits.h.

References One.

Referenced by llvm::SelectionDAG::computeKnownBits(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromShiftOperator(), computeKnownBitsMul(), llvm::SelectionDAG::isKnownNeverZero(), isKnownNonZeroFromOperator(), llvm::isKnownPositive(), isNonZeroAdd(), isNonZeroMul(), srem(), and llvm::InstCombinerImpl::visitCallInst().

◆ isSignUnknown()

bool llvm::KnownBits::isSignUnknown ( ) const	inline

◆ isStrictlyPositive()

bool llvm::KnownBits::isStrictlyPositive ( ) const	inline

◆ isUnknown()

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

Returns true if we don't know any bits.

Definition at line 66 of file KnownBits.h.

References One, and Zero.

Referenced by llvm::FunctionLoweringInfo::AddLiveOutRegInfo(), llvm::adjustKnownBitsForSelectArm(), ashr(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsAddSub(), llvm::SITargetLowering::computeKnownBitsForTargetInstr(), llvm::AMDGPUTargetLowering::computeKnownBitsForTargetNode(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::RISCVTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelValueTracking::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 80 of file KnownBits.h.

References Zero.

Referenced by llvm::AMDGPULegalizerInfo::buildMultiply(), combineMOVMSK(), llvm::GISelValueTracking::computeNumSignBits(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), isZero(), LowerVectorAllEqual(), llvm::SelectionDAG::MaskedVectorIsZero(), matchBinaryShuffle(), performUADDVCombine(), llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(), simplifyDivRem(), llvm::TargetLowering::SimplifyMultipleUseDemandedBits(), and simplifyX86immShift().

◆ lshr()

Compute known bits for lshr(LHS, RHS).

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

Definition at line 369 of file KnownBits.cpp.

References llvm::BitWidth, getMaxShiftAmount(), llvm::APInt::getMaxValue(), hasConflict(), intersectWith(), isUnknown(), setAllConflict(), setAllZero(), llvm::APInt::setHighBits(), and Zero.

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

◆ makeConstant()

Create known bits from a known constant.

Definition at line 301 of file KnownBits.h.

References llvm::CallingConv::C, and KnownBits().

Referenced by abs(), binaryOpKnownBitsMapHelper(), computeKnownBits(), llvm::SelectionDAG::computeKnownBits(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromCmp(), llvm::computeKnownBitsFromContext(), computeKnownBitsFromLerpPattern(), computeKnownBitsFromOperator(), llvm::GISelValueTracking::computeKnownBitsImpl(), computeKnownBitsMul(), computeKnownFPClass(), llvm::FunctionLoweringInfo::ComputePHILiveOutRegInfo(), fromOptionalToKnownBits(), isSignificantBitCheckWellFormed(), knownBitsMapHelper(), llvm::TargetLowering::SimplifyDemandedBits(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), targetOpKnownBitsMapHelper(), and llvm::ConstantRange::toKnownBits().

◆ makeGE()

◆ makeNegative()

void llvm::KnownBits::makeNegative ( )	inline

◆ makeNonNegative()

void llvm::KnownBits::makeNonNegative ( )	inline

◆ mul()

Compute known bits resulting from multiplying LHS and RHS.

Definition at line 800 of file KnownBits.cpp.

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

Referenced by binaryOpKnownBitsMapHelper(), llvm::SelectionDAG::computeKnownBits(), computeKnownBitsForPMADDUBSW(), computeKnownBitsForPMADDWD(), llvm::AArch64TargetLowering::computeKnownBitsForTargetNode(), llvm::ARMTargetLowering::computeKnownBitsForTargetNode(), llvm::X86TargetLowering::computeKnownBitsForTargetNode(), computeKnownBitsFromOperator(), llvm::GISelValueTracking::computeKnownBitsImpl(), computeKnownBitsMul(), matchVPMADD52(), mulhs(), mulhu(), llvm::TargetLowering::SimplifyDemandedBits(), and llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode().

◆ mulhs()

◆ mulhu()

◆ ne()

◆ operator!=()

◆ operator&=()

◆ operator<<=()

Shift known bits left by ShAmt. Shift in bits are unknown.

Definition at line 498 of file KnownBits.h.

References One, and Zero.

◆ operator==()

◆ operator>>=()

Shift known bits right by ShAmt. Shifted in bits are unknown.

Definition at line 505 of file KnownBits.h.

References One, and Zero.

◆ operator^=()

◆ operator|=()

◆ print()

◆ resetAll()

void llvm::KnownBits::resetAll ( )	inline

Resets the known state of all bits.

Definition at line 74 of file KnownBits.h.

References One, and Zero.

◆ reverseBits()

KnownBits llvm::KnownBits::reverseBits ( ) const	inline

◆ sadd_sat()

◆ sdiv()

Compute known bits for sdiv(LHS, RHS).

Definition at line 957 of file KnownBits.cpp.

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

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

◆ setAllConflict()

void llvm::KnownBits::setAllConflict ( )	inline

◆ setAllOnes()

void llvm::KnownBits::setAllOnes ( )	inline

◆ setAllZero()

void llvm::KnownBits::setAllZero ( )	inline

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

Definition at line 86 of file KnownBits.h.

References One, and Zero.

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

◆ sext()

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

Definition at line 180 of file KnownBits.h.

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

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

◆ sextInReg()

◆ sextOrTrunc()

◆ sge()

◆ sgt()

◆ shl()

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(), llvm::APInt::getMaxValue(), hasConflict(), intersectWith(), llvm::isPowerOf2_32(), isUnknown(), makeNegative(), makeNonNegative(), One, setAllConflict(), setAllZero(), llvm::APInt::setLowBits(), llvm::APInt::setSignBit(), llvm::APInt::ushl_ov(), and Zero.

◆ sle()

◆ slt()

◆ smax()

◆ smin()

◆ srem()

◆ ssub_sat()

◆ sub()

◆ trunc()

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

Definition at line 161 of file KnownBits.h.

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

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

◆ uadd_sat()

◆ udiv()

Compute known bits for udiv(LHS, RHS).

Definition at line 1013 of file KnownBits.cpp.

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

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

◆ uge()

◆ ugt()

◆ ule()

◆ ult()

◆ umax()

◆ umin()

◆ unionWith()

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 321 of file KnownBits.h.

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

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