#include "InstCombineInternal.h"
#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"
#include "llvm/Transforms/Utils/Local.h"

Include dependency graph for InstCombineAndOrXor.cpp:

Classes
struct	IntPart

Macros
#define	DEBUG_TYPE "instcombine"

Enumerations
enum	MaskedICmpType { AMask_AllOnes = 1, AMask_NotAllOnes = 2, BMask_AllOnes = 4, BMask_NotAllOnes = 8, Mask_AllZeros = 16, Mask_NotAllZeros = 32, AMask_Mixed = 64, AMask_NotMixed = 128, BMask_Mixed = 256, BMask_NotMixed = 512 }
	Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns that can be simplified. More...

Functions
static unsigned	getFCmpCode (FCmpInst::Predicate CC)
	Similar to getICmpCode but for FCmpInst. More...

static Value *	getNewICmpValue (unsigned Code, bool Sign, Value LHS, Value RHS, InstCombiner::BuilderTy &Builder)
	This is the complement of getICmpCode, which turns an opcode and two operands into either a constant true or false, or a brand new ICmp instruction. More...

static Value *	getFCmpValue (unsigned Code, Value LHS, Value RHS, InstCombiner::BuilderTy &Builder)
	This is the complement of getFCmpCode, which turns an opcode and two operands into either a FCmp instruction, or a true/false constant. More...

static Value *	SimplifyBSwap (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Transform BITWISE_OP(BSWAP(A),BSWAP(B)) or BITWISE_OP(BSWAP(A), Constant) to BSWAP(BITWISE_OP(A, B)) More...

static unsigned	getMaskedICmpType (Value A, Value B, Value *C, ICmpInst::Predicate Pred)
	Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C) satisfies. More...

static unsigned	conjugateICmpMask (unsigned Mask)
	Convert an analysis of a masked ICmp into its equivalent if all boolean operations had the opposite sense. More...

static bool	decomposeBitTestICmp (Value LHS, Value RHS, CmpInst::Predicate &Pred, Value &X, Value &Y, Value *&Z)

static Optional< std::pair< unsigned, unsigned > >	getMaskedTypeForICmpPair (Value &A, Value &B, Value &C, Value &D, Value &E, ICmpInst LHS, ICmpInst *RHS, ICmpInst::Predicate &PredL, ICmpInst::Predicate &PredR)
	Handle (icmp(A & B) ==/!= C) &/\| (icmp(A & D) ==/!= E). More...

static Value *	foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed (ICmpInst LHS, ICmpInst RHS, bool IsAnd, Value A, Value B, Value C, Value D, Value *E, ICmpInst::Predicate PredL, ICmpInst::Predicate PredR, InstCombiner::BuilderTy &Builder)
	Try to fold (icmp(A & B) ==/!= C) &/\| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y), where the left-hand side is of type Mask_NotAllZeros and the right hand side is of type BMask_Mixed. More...

static Value *	foldLogOpOfMaskedICmpsAsymmetric (ICmpInst LHS, ICmpInst RHS, bool IsAnd, Value A, Value B, Value C, Value D, Value *E, ICmpInst::Predicate PredL, ICmpInst::Predicate PredR, unsigned LHSMask, unsigned RHSMask, InstCombiner::BuilderTy &Builder)
	Try to fold (icmp(A & B) ==/!= 0) &/\| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y), where the left-hand side and the right hand side aren't of the common mask pattern type. More...

static Value *	foldLogOpOfMaskedICmps (ICmpInst LHS, ICmpInst RHS, bool IsAnd, InstCombiner::BuilderTy &Builder)
	Try to fold (icmp(A & B) ==/!= C) &/\| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y). More...

static Value *	foldAndOrOfEqualityCmpsWithConstants (ICmpInst LHS, ICmpInst RHS, bool JoinedByAnd, InstCombiner::BuilderTy &Builder)

static Value *	foldSignedTruncationCheck (ICmpInst ICmp0, ICmpInst ICmp1, Instruction &CxtI, InstCombiner::BuilderTy &Builder)
	General pattern: X & Y. More...

static Value *	foldIsPowerOf2 (ICmpInst Cmp0, ICmpInst Cmp1, bool JoinedByAnd, InstCombiner::BuilderTy &Builder)
	Reduce a pair of compares that check if a value has exactly 1 bit set. More...

static Value *	foldUnsignedUnderflowCheck (ICmpInst ZeroICmp, ICmpInst UnsignedICmp, bool IsAnd, const SimplifyQuery &Q, InstCombiner::BuilderTy &Builder)
	Commuted variants are assumed to be handled by calling this function again with the parameters swapped. More...

static Optional< IntPart >	matchIntPart (Value *V)
	Match an extraction of bits from an integer. More...

static Value *	extractIntPart (const IntPart &P, IRBuilderBase &Builder)
	Materialize an extraction of bits from an integer in IR. More...

static Value *	foldEqOfParts (ICmpInst Cmp0, ICmpInst Cmp1, bool IsAnd, InstCombiner::BuilderTy &Builder)
	(icmp eq X0, Y0) & (icmp eq X1, Y1) -> icmp eq X01, Y01 (icmp ne X0, Y0) \| (icmp ne X1, Y1) -> icmp ne X01, Y01 where X0, X1 and Y0, Y1 are adjacent parts extracted from an integer. More...

static Value *	foldAndOrOfICmpsWithConstEq (ICmpInst Cmp0, ICmpInst Cmp1, BinaryOperator &Logic, InstCombiner::BuilderTy &Builder, const SimplifyQuery &Q)
	Reduce logic-of-compares with equality to a constant by substituting a common operand with the constant. More...

static Instruction *	reassociateFCmps (BinaryOperator &BO, InstCombiner::BuilderTy &Builder)
	This a limited reassociation for a special case (see above) where we are checking if two values are either both NAN (unordered) or not-NAN (ordered). More...

static Instruction *	matchDeMorgansLaws (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Match De Morgan's Laws: (~A & ~B) == (~(A \| B)) (~A \| ~B) == (~(A & B)) More...

static Instruction *	foldLogicCastConstant (BinaryOperator &Logic, CastInst *Cast, InstCombiner::BuilderTy &Builder)
	Fold {and,or,xor} (cast X), C. More...

static Instruction *	foldAndToXor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)

static Instruction *	foldOrToXor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)

static bool	canNarrowShiftAmt (Constant *C, unsigned BitWidth)
	Return true if a constant shift amount is always less than the specified bit-width. More...

static Instruction *	matchFunnelShift (Instruction &Or, InstCombinerImpl &IC)
	Match UB-safe variants of the funnel shift intrinsic. More...

static Instruction *	matchOrConcat (Instruction &Or, InstCombiner::BuilderTy &Builder)
	Attempt to combine or(zext(x),shl(zext(y),bw/2) concat packing patterns. More...

static bool	areInverseVectorBitmasks (Constant C1, Constant C2)
	If all elements of two constant vectors are 0/-1 and inverses, return true. More...

static Instruction *	foldXorToXor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	A ^ B can be specified using other logic ops in a variety of patterns. More...

static Instruction *	visitMaskedMerge (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	If we have a masked merge, in the canonical form of: (assuming that A only has one use.) \| A \| \|B\| ((x ^ y) & M) ^ y \| D \|. More...

static Instruction *	sinkNotIntoXor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)

static Instruction *	canonicalizeAbs (BinaryOperator &Xor, InstCombiner::BuilderTy &Builder)
	Canonicalize a shifty way to code absolute value to the more common pattern that uses negation and select. More...

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "instcombine"

Definition at line 25 of file InstCombineAndOrXor.cpp.

Enumeration Type Documentation

◆ MaskedICmpType

enum MaskedICmpType

Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns that can be simplified.

One of A and B is considered the mask. The other is the value. This is described as the "AMask" or "BMask" part of the enum. If the enum contains only "Mask", then both A and B can be considered masks. If A is the mask, then it was proven that (A & C) == C. This is trivial if C == A or C == 0. If both A and C are constants, this proof is also easy. For the following explanations, we assume that A is the mask.

"AllOnes" declares that the comparison is true only if (A & B) == A or all bits of A are set in B. Example: (icmp eq (A & 3), 3) -> AMask_AllOnes

"AllZeros" declares that the comparison is true only if (A & B) == 0 or all bits of A are cleared in B. Example: (icmp eq (A & 3), 0) -> Mask_AllZeroes

"Mixed" declares that (A & B) == C and C might or might not contain any number of one bits and zero bits. Example: (icmp eq (A & 3), 1) -> AMask_Mixed

"Not" means that in above descriptions "==" should be replaced by "!=". Example: (icmp ne (A & 3), 3) -> AMask_NotAllOnes

If the mask A contains a single bit, then the following is equivalent: (icmp eq (A & B), A) equals (icmp ne (A & B), 0) (icmp ne (A & B), A) equals (icmp eq (A & B), 0)

Enumerator
AMask_AllOnes
AMask_NotAllOnes
BMask_AllOnes
BMask_NotAllOnes
Mask_AllZeros
Mask_NotAllZeros
AMask_Mixed
AMask_NotMixed
BMask_Mixed
BMask_NotMixed

Definition at line 171 of file InstCombineAndOrXor.cpp.

Function Documentation

◆ areInverseVectorBitmasks()

static bool areInverseVectorBitmasks	(	Constant *	C1,
		Constant *	C2
	)

static

If all elements of two constant vectors are 0/-1 and inverses, return true.

Definition at line 2267 of file InstCombineAndOrXor.cpp.

References C1, llvm::Constant::getAggregateElement(), i, llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_Zero(), and llvm::PatternMatch::match().

◆ canNarrowShiftAmt()

static bool canNarrowShiftAmt	(	Constant *	C,
		unsigned	BitWidth
	)

static

Return true if a constant shift amount is always less than the specified bit-width.

If not, the shift could create poison in the narrower type.

Definition at line 1735 of file InstCombineAndOrXor.cpp.

References llvm::BitWidth, llvm::CmpInst::ICMP_ULT, llvm::PatternMatch::m_SpecificInt_ICMP(), llvm::PatternMatch::match(), and Threshold.

◆ canonicalizeAbs()

static Instruction* canonicalizeAbs	(	BinaryOperator &	Xor,
		InstCombiner::BuilderTy &	Builder
	)

static

Canonicalize a shifty way to code absolute value to the more common pattern that uses negation and select.

Definition at line 3205 of file InstCombineAndOrXor.cpp.

References assert(), Builder, llvm::SelectInst::Create(), llvm::Constant::getNullValue(), llvm::Type::getScalarSizeInBits(), llvm::Value::hasNUses(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_AShr(), llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), std::swap(), and llvm::Xor.

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

◆ conjugateICmpMask()

static unsigned conjugateICmpMask ( unsigned Mask )

static

Convert an analysis of a masked ICmp into its equivalent if all boolean operations had the opposite sense.

Since each "NotXXX" flag (recording !=) is adjacent to the corresponding normal flag (recording ==), this just involves swapping those bits over.

Definition at line 235 of file InstCombineAndOrXor.cpp.

References AMask_AllOnes, AMask_Mixed, AMask_NotAllOnes, AMask_NotMixed, BMask_AllOnes, BMask_Mixed, BMask_NotAllOnes, BMask_NotMixed, llvm::BitmaskEnumDetail::Mask(), Mask_AllZeros, and Mask_NotAllZeros.

Referenced by foldLogOpOfMaskedICmps(), and foldLogOpOfMaskedICmpsAsymmetric().

◆ decomposeBitTestICmp()

static bool decomposeBitTestICmp	(	Value *	LHS,
		Value *	RHS,
		CmpInst::Predicate &	Pred,
		Value *&	X,
		Value *&	Y,
		Value *&	Z
	)

static

Definition at line 249 of file InstCombineAndOrXor.cpp.

References llvm::decomposeBitTestICmp(), llvm::ConstantInt::get(), llvm::BitmaskEnumDetail::Mask(), X, and Y.

◆ extractIntPart()

static Value* extractIntPart	(	const IntPart &	P,
		IRBuilderBase &	Builder
	)

static

Materialize an extraction of bits from an integer in IR.

Definition at line 1103 of file InstCombineAndOrXor.cpp.

References Builder, llvm::Value::getType(), llvm::Type::getWithNewBitWidth(), and P.

Referenced by foldEqOfParts().

◆ foldAndOrOfEqualityCmpsWithConstants()

static Value* foldAndOrOfEqualityCmpsWithConstants	(	ICmpInst *	LHS,
		ICmpInst *	RHS,
		bool	JoinedByAnd,
		InstCombiner::BuilderTy &	Builder
	)

static

Definition at line 743 of file InstCombineAndOrXor.cpp.

References Builder, C1, llvm::ConstantInt::get(), llvm::User::getOperand(), llvm::CmpInst::getPredicate(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::PatternMatch::m_APInt(), llvm::PatternMatch::match(), llvm::Or, std::swap(), X, and llvm::Xor.

◆ foldAndOrOfICmpsWithConstEq()

static Value* foldAndOrOfICmpsWithConstEq	(	ICmpInst *	Cmp0,
		ICmpInst *	Cmp1,
		BinaryOperator &	Logic,
		InstCombiner::BuilderTy &	Builder,
		const SimplifyQuery &	Q
	)

static

Reduce logic-of-compares with equality to a constant by substituting a common operand with the constant.

Callers are expected to call this with Cmp0/Cmp1 switched to handle logic op commutativity.

Definition at line 1162 of file InstCombineAndOrXor.cpp.

References assert(), Builder, llvm::BinaryOperator::getOpcode(), llvm::Value::hasOneUse(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::isGuaranteedNotToBeUndefOrPoison(), llvm::PatternMatch::m_c_ICmp(), llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_ICmp(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::SimplifyICmpInst(), X, and Y.

◆ foldAndToXor()

static Instruction* foldAndToXor	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

Definition at line 1673 of file InstCombineAndOrXor.cpp.

References assert(), B, Builder, llvm::BinaryOperator::CreateNot(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_BinOp(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Or(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

◆ foldEqOfParts()

static Value* foldEqOfParts	(	ICmpInst *	Cmp0,
		ICmpInst *	Cmp1,
		bool	IsAnd,
		InstCombiner::BuilderTy &	Builder
	)

static

(icmp eq X0, Y0) & (icmp eq X1, Y1) -> icmp eq X01, Y01 (icmp ne X0, Y0) | (icmp ne X1, Y1) -> icmp ne X01, Y01 where X0, X1 and Y0, Y1 are adjacent parts extracted from an integer.

Definition at line 1116 of file InstCombineAndOrXor.cpp.

References Builder, extractIntPart(), IntPart::From, llvm::User::getOperand(), llvm::CmpInst::getPredicate(), llvm::Value::hasOneUse(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, LValue, matchIntPart(), IntPart::NumBits, RValue, IntPart::StartBit, and std::swap().

◆ foldIsPowerOf2()

static Value* foldIsPowerOf2	(	ICmpInst *	Cmp0,
		ICmpInst *	Cmp1,
		bool	JoinedByAnd,
		InstCombiner::BuilderTy &	Builder
	)

static

Reduce a pair of compares that check if a value has exactly 1 bit set.

Definition at line 962 of file InstCombineAndOrXor.cpp.

References Builder, llvm::ConstantInt::get(), llvm::User::getOperand(), llvm::CmpInst::getPredicate(), llvm::Value::getType(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::PatternMatch::m_ICmp(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_SpecificInt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZeroInt(), llvm::PatternMatch::match(), std::swap(), and X.

◆ foldLogicCastConstant()

static Instruction* foldLogicCastConstant	(	BinaryOperator &	Logic,
		CastInst *	Cast,
		InstCombiner::BuilderTy &	Builder
	)

static

Fold {and,or,xor} (cast X), C.

Definition at line 1568 of file InstCombineAndOrXor.cpp.

References Builder, llvm::BinaryOperator::getOpcode(), llvm::User::getOperand(), llvm::ConstantExpr::getSExt(), llvm::CastInst::getSrcTy(), llvm::ConstantExpr::getTrunc(), llvm::Value::getType(), llvm::ConstantExpr::getZExt(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_SExt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZExt(), llvm::PatternMatch::match(), and X.

◆ foldLogOpOfMaskedICmps()

static Value* foldLogOpOfMaskedICmps	(	ICmpInst *	LHS,
		ICmpInst *	RHS,
		bool	IsAnd,
		InstCombiner::BuilderTy &	Builder
	)

static

Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y).

Definition at line 551 of file InstCombineAndOrXor.cpp.

References AMask_AllOnes, AMask_NotAllOnes, assert(), B, BMask_AllOnes, BMask_Mixed, BMask_NotAllOnes, Builder, conjugateICmpMask(), D, E, foldLogOpOfMaskedICmpsAsymmetric(), llvm::ConstantInt::get(), getMaskedTypeForICmpPair(), llvm::Constant::getNullValue(), llvm::ConstantExpr::getOr(), llvm::CmpInst::getPredicate(), llvm::Value::getType(), llvm::ConstantInt::getValue(), llvm::ConstantExpr::getXor(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::ICmpInst::isEquality(), llvm::PatternMatch::m_ConstantInt(), llvm::BitmaskEnumDetail::Mask(), Mask_AllZeros, Mask_NotAllZeros, and llvm::PatternMatch::match().

◆ foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed()

static Value* foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed	(	ICmpInst *	LHS,
		ICmpInst *	RHS,
		bool	IsAnd,
		Value *	A,
		Value *	B,
		Value *	C,
		Value *	D,
		Value *	E,
		ICmpInst::Predicate	PredL,
		ICmpInst::Predicate	PredR,
		InstCombiner::BuilderTy &	Builder
	)

static

Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y), where the left-hand side is of type Mask_NotAllZeros and the right hand side is of type BMask_Mixed.

For example, (icmp (A & 12) != 0) & (icmp (A & 15) == 8) -> (icmp (A & 15) == 8).

Definition at line 397 of file InstCombineAndOrXor.cpp.

References assert(), B, Builder, C1, D, E, llvm::ConstantInt::get(), llvm::ConstantInt::getType(), llvm::Value::getType(), llvm::ConstantInt::getValue(), llvm::ConstantExpr::getXor(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::ConstantInt::isZero(), llvm::PatternMatch::m_ConstantInt(), and llvm::PatternMatch::match().

Referenced by foldLogOpOfMaskedICmpsAsymmetric().

◆ foldLogOpOfMaskedICmpsAsymmetric()

static Value* foldLogOpOfMaskedICmpsAsymmetric	(	ICmpInst *	LHS,
		ICmpInst *	RHS,
		bool	IsAnd,
		Value *	A,
		Value *	B,
		Value *	C,
		Value *	D,
		Value *	E,
		ICmpInst::Predicate	PredL,
		ICmpInst::Predicate	PredR,
		unsigned	LHSMask,
		unsigned	RHSMask,
		InstCombiner::BuilderTy &	Builder
	)

static

Try to fold (icmp(A & B) ==/!= 0) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y), where the left-hand side and the right hand side aren't of the common mask pattern type.

Definition at line 518 of file InstCombineAndOrXor.cpp.

References assert(), B, BMask_Mixed, Builder, conjugateICmpMask(), D, E, foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed(), llvm::ICmpInst::isEquality(), and Mask_NotAllZeros.

Referenced by foldLogOpOfMaskedICmps().

◆ foldOrToXor()

static Instruction* foldOrToXor	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

Definition at line 1699 of file InstCombineAndOrXor.cpp.

References assert(), B, Builder, llvm::BinaryOperator::CreateNot(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Or(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Xor(), and llvm::PatternMatch::match().

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

◆ foldSignedTruncationCheck()

static Value* foldSignedTruncationCheck	(	ICmpInst *	ICmp0,
		ICmpInst *	ICmp1,
		Instruction &	CxtI,
		InstCombiner::BuilderTy &	Builder
	)

static

General pattern: X & Y.

Where Y is checking that all the high bits (covered by a mask 4294967168) are uniform, i.e. arg & 4294967168 can be either 4294967168 or 0 Pattern can be one of: t = add i32 arg, 128 r = icmp ult i32 t, 256 Or t0 = shl i32 arg, 24 t1 = ashr i32 t0, 24 r = icmp eq i32 t1, arg Or t0 = trunc i32 arg to i8 t1 = sext i8 t0 to i32 r = icmp eq i32 t1, arg This pattern is a signed truncation check.

And X is checking that some bit in that same mask is zero. I.e. can be one of: r = icmp sgt i32 arg, -1 Or t = and i32 arg, 2147483648 r = icmp eq i32 t, 0

Since we are checking that all the bits in that mask are the same, and a particular bit is zero, what we are really checking is that all the masked bits are zero. So this should be transformed to: r = icmp ult i32 arg, 128

Definition at line 867 of file InstCombineAndOrXor.cpp.

◆ foldUnsignedUnderflowCheck()

static Value* foldUnsignedUnderflowCheck	(	ICmpInst *	ZeroICmp,
		ICmpInst *	UnsignedICmp,
		bool	IsAnd,
		const SimplifyQuery &	Q,
		InstCombiner::BuilderTy &	Builder
	)

static

Commuted variants are assumed to be handled by calling this function again with the parameters swapped.

Definition at line 993 of file InstCombineAndOrXor.cpp.

◆ foldXorToXor()

static Instruction* foldXorToXor	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

A ^ B can be specified using other logic ops in a variety of patterns.

We can fold these early and efficiently by morphing an existing instruction.

Definition at line 2982 of file InstCombineAndOrXor.cpp.

References assert(), B, Builder, llvm::BinaryOperator::CreateNot(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Or(), llvm::PatternMatch::m_c_Xor(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Xor(), and llvm::PatternMatch::match().

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

◆ getFCmpCode()

static unsigned getFCmpCode ( FCmpInst::Predicate CC )

static

Similar to getICmpCode but for FCmpInst.

This encodes a fcmp predicate into a four bit mask.

Definition at line 29 of file InstCombineAndOrXor.cpp.

References assert(), llvm::CmpInst::FCMP_FALSE, llvm::CmpInst::FCMP_OEQ, llvm::CmpInst::FCMP_OGE, llvm::CmpInst::FCMP_OGT, llvm::CmpInst::FCMP_OLE, llvm::CmpInst::FCMP_OLT, llvm::CmpInst::FCMP_ONE, llvm::CmpInst::FCMP_ORD, llvm::CmpInst::FCMP_TRUE, llvm::CmpInst::FCMP_UEQ, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::CmpInst::FCMP_UNE, and llvm::CmpInst::FCMP_UNO.

◆ getFCmpValue()

static Value* getFCmpValue	(	unsigned	Code,
		Value *	LHS,
		Value *	RHS,
		InstCombiner::BuilderTy &	Builder
	)

static

This is the complement of getFCmpCode, which turns an opcode and two operands into either a FCmp instruction, or a true/false constant.

Definition at line 67 of file InstCombineAndOrXor.cpp.

References assert(), Builder, llvm::CmpInst::FCMP_FALSE, llvm::CmpInst::FCMP_TRUE, llvm::ConstantInt::get(), llvm::Value::getType(), and llvm::CmpInst::makeCmpResultType().

◆ getMaskedICmpType()

static unsigned getMaskedICmpType	(	Value *	A,
		Value *	B,
		Value *	C,
		ICmpInst::Predicate	Pred
	)

static

Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C) satisfies.

Definition at line 186 of file InstCombineAndOrXor.cpp.

References AMask_AllOnes, AMask_Mixed, AMask_NotAllOnes, AMask_NotMixed, B, BMask_AllOnes, BMask_Mixed, BMask_NotAllOnes, BMask_NotMixed, llvm::ConstantExpr::getAnd(), llvm::ConstantInt::getValue(), llvm::CmpInst::ICMP_EQ, llvm::APInt::isPowerOf2(), llvm::ConstantInt::isZero(), Mask_AllZeros, and Mask_NotAllZeros.

Referenced by getMaskedTypeForICmpPair().

◆ getMaskedTypeForICmpPair()

static Optional<std::pair<unsigned, unsigned> > getMaskedTypeForICmpPair	(	Value *&	A,
		Value *&	B,
		Value *&	C,
		Value *&	D,
		Value *&	E,
		ICmpInst *	LHS,
		ICmpInst *	RHS,
		ICmpInst::Predicate &	PredL,
		ICmpInst::Predicate &	PredR
	)

static

Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).

Return the pattern classes (from MaskedICmpType) for the left hand side and the right hand side as a pair. LHS and RHS are the left hand side and the right hand side ICmps and PredL and PredR are their predicates, respectively.

Definition at line 267 of file InstCombineAndOrXor.cpp.

References B, D, llvm::decomposeBitTestICmp(), E, llvm::Constant::getAllOnesValue(), getMaskedICmpType(), llvm::User::getOperand(), llvm::Value::getType(), llvm::ICmpInst::isEquality(), llvm::Type::isIntegerTy(), L2, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::None, and R2.

Referenced by foldLogOpOfMaskedICmps().

◆ getNewICmpValue()

static Value* getNewICmpValue	(	unsigned	Code,
		bool	Sign,
		Value *	LHS,
		Value *	RHS,
		InstCombiner::BuilderTy &	Builder
	)

static

This is the complement of getICmpCode, which turns an opcode and two operands into either a constant true or false, or a brand new ICmp instruction.

The sign is passed in to determine which kind of predicate to use in the new icmp instruction.

Definition at line 57 of file InstCombineAndOrXor.cpp.

References Builder, llvm::getPredForICmpCode(), and llvm::Value::getType().

◆ matchDeMorgansLaws()

static Instruction* matchDeMorgansLaws	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

Match De Morgan's Laws: (~A & ~B) == (~(A | B)) (~A | ~B) == (~(A & B))

Definition at line 1530 of file InstCombineAndOrXor.cpp.

References assert(), B, Builder, llvm::BinaryOperator::CreateNot(), I, llvm::InstCombiner::isFreeToInvert(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

Referenced by llvm::InstCombinerImpl::visitAnd(), and llvm::InstCombinerImpl::visitOr().

◆ matchFunnelShift()

static Instruction* matchFunnelShift	(	Instruction &	Or,
		InstCombinerImpl &	IC
	)

static

Match UB-safe variants of the funnel shift intrinsic.

Definition at line 2112 of file InstCombineAndOrXor.cpp.

Referenced by foldGuardedFunnelShift(), and llvm::InstCombinerImpl::visitOr().

◆ matchIntPart()

static Optional<IntPart> matchIntPart ( Value * V )

static

Match an extraction of bits from an integer.

Definition at line 1085 of file InstCombineAndOrXor.cpp.

References llvm::Type::getScalarSizeInBits(), llvm::Value::getType(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_LShr(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Trunc(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::None, Shift, X, and Y.

Referenced by foldEqOfParts().

◆ matchOrConcat()

static Instruction* matchOrConcat	(	Instruction &	Or,
		InstCombiner::BuilderTy &	Builder
	)

static

Attempt to combine or(zext(x),shl(zext(y),bw/2) concat packing patterns.

Definition at line 2214 of file InstCombineAndOrXor.cpp.

References assert(), Builder, F, llvm::Intrinsic::getDeclaration(), llvm::Type::getScalarSizeInBits(), llvm::Value::getType(), llvm::MipsISD::Hi, llvm::MipsISD::Lo, llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_BitReverse(), llvm::PatternMatch::m_BSwap(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZExt(), llvm::PatternMatch::match(), llvm::Or, and std::swap().

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

◆ reassociateFCmps()

static Instruction* reassociateFCmps	(	BinaryOperator &	BO,
		InstCombiner::BuilderTy &	Builder
	)

static

This a limited reassociation for a special case (see above) where we are checking if two values are either both NAN (unordered) or not-NAN (ordered).

This could be handled more generally in '-reassociation', but it seems like an unlikely pattern for a large number of logic ops and fcmps.

Definition at line 1485 of file InstCombineAndOrXor.cpp.

References assert(), Builder, llvm::BinaryOperator::Create(), llvm::CmpInst::FCMP_ORD, llvm::CmpInst::FCMP_UNO, llvm::BinaryOperator::getOpcode(), llvm::User::getOperand(), llvm::PatternMatch::m_AnyZeroFP(), llvm::PatternMatch::m_BinOp(), llvm::PatternMatch::m_FCmp(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), std::swap(), X, and Y.

Referenced by llvm::InstCombinerImpl::visitAnd(), and llvm::InstCombinerImpl::visitOr().

◆ SimplifyBSwap()

static Value* SimplifyBSwap	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

Transform BITWISE_OP(BSWAP(A),BSWAP(B)) or BITWISE_OP(BSWAP(A), Constant) to BSWAP(BITWISE_OP(A, B))

Parameters

I	Binary operator to transform.

Returns: Pointer to node that must replace the original binary operator, or null pointer if no transformation was made.

Definition at line 84 of file InstCombineAndOrXor.cpp.

References assert(), Builder, F, llvm::ConstantInt::get(), llvm::Intrinsic::getDeclaration(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_BSwap(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

Referenced by llvm::InstCombinerImpl::visitAnd(), llvm::InstCombinerImpl::visitOr(), and llvm::InstCombinerImpl::visitXor().

◆ sinkNotIntoXor()

static Instruction* sinkNotIntoXor	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

Definition at line 3183 of file InstCombineAndOrXor.cpp.

References Builder, I, llvm::InstCombiner::isFreeToInvert(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Xor(), llvm::PatternMatch::match(), std::swap(), X, and Y.

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

◆ visitMaskedMerge()

static Instruction* visitMaskedMerge	(	BinaryOperator &	I,
		InstCombiner::BuilderTy &	Builder
	)

static

If we have a masked merge, in the canonical form of: (assuming that A only has one use.) | A | |B| ((x ^ y) & M) ^ y | D |.

If M is inverted: | D | ((x ^ y) & ~M) ^ y We can canonicalize by swapping the final xor operand to eliminate the 'not' of the mask. ((x ^ y) & M) ^ x
If M is a constant, and D has one use, we transform to 'and' / 'or' ops because that shortens the dependency chain and improves analysis: (x & M) | (y & ~M)

Definition at line 3144 of file InstCombineAndOrXor.cpp.

References B, Builder, D, llvm::Constant::getAllOnesValue(), llvm::Type::getScalarType(), I, M, llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Xor(), llvm::PatternMatch::m_CombineAnd(), llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::Constant::replaceUndefsWith(), and X.

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

Classes

Macros

Enumerations

Functions

Macro Definition Documentation

◆ DEBUG_TYPE

Enumeration Type Documentation

◆ MaskedICmpType

Function Documentation

◆ areInverseVectorBitmasks()

◆ canNarrowShiftAmt()

◆ canonicalizeAbs()

◆ conjugateICmpMask()

◆ decomposeBitTestICmp()

◆ extractIntPart()

◆ foldAndOrOfEqualityCmpsWithConstants()

◆ foldAndOrOfICmpsWithConstEq()

◆ foldAndToXor()

◆ foldEqOfParts()

◆ foldIsPowerOf2()

◆ foldLogicCastConstant()

◆ foldLogOpOfMaskedICmps()

◆ foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed()

◆ foldLogOpOfMaskedICmpsAsymmetric()

◆ foldOrToXor()

◆ foldSignedTruncationCheck()

◆ foldUnsignedUnderflowCheck()

◆ foldXorToXor()

◆ getFCmpCode()

◆ getFCmpValue()

◆ getMaskedICmpType()

◆ getMaskedTypeForICmpPair()

◆ getNewICmpValue()

◆ matchDeMorgansLaws()

◆ matchFunnelShift()

◆ matchIntPart()

◆ matchOrConcat()

◆ reassociateFCmps()

◆ SimplifyBSwap()

◆ sinkNotIntoXor()

◆ visitMaskedMerge()