InstCombineCompares.cpp File Reference

#include "InstCombineInternal.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/Utils/Local.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"
#include <bitset>

Go to the source code of this file.

Classes
struct	OffsetResult

Macros
#define	DEBUG_TYPE   "instcombine"

Typedefs
using	OffsetOp = std::pair< Instruction::BinaryOps, Value * >
	Find all possible pairs (BinOp, RHS) that BinOp V, RHS can be simplified.

Enumerations
enum class	OffsetKind { Invalid , Value , Select }

Functions
	STATISTIC (NumSel, "Number of select opts")
static bool	addWithOverflow (APInt &Result, const APInt &In1, const APInt &In2, bool IsSigned=false)
	Compute Result = In1+In2, returning true if the result overflowed for this type.
static bool	subWithOverflow (APInt &Result, const APInt &In1, const APInt &In2, bool IsSigned=false)
	Compute Result = In1-In2, returning true if the result overflowed for this type.
static bool	hasBranchUse (ICmpInst &I)
	Given an icmp instruction, return true if any use of this comparison is a branch on sign bit comparison.
static bool	isSignTest (ICmpInst::Predicate &Pred, const APInt &C)
	Returns true if the exploded icmp can be expressed as a signed comparison to zero and updates the predicate accordingly.
static bool	canRewriteGEPAsOffset (Value *Start, Value *Base, GEPNoWrapFlags &NW, const DataLayout &DL, SetVector< Value * > &Explored)
	Returns true if we can rewrite Start as a GEP with pointer Base and some integer offset.
static void	setInsertionPoint (IRBuilder<> &Builder, Value *V, bool Before=true)
static Value *	rewriteGEPAsOffset (Value *Start, Value *Base, GEPNoWrapFlags NW, const DataLayout &DL, SetVector< Value * > &Explored, InstCombiner &IC)
	Returns a re-written value of Start as an indexed GEP using Base as a pointer.
static Instruction *	transformToIndexedCompare (GEPOperator *GEPLHS, Value *RHS, CmpPredicate Cond, const DataLayout &DL, InstCombiner &IC)
	Converts (CMP GEPLHS, RHS) if this change would make RHS a constant.
static Instruction *	processUGT_ADDCST_ADD (ICmpInst &I, Value *A, Value *B, ConstantInt *CI2, ConstantInt *CI1, InstCombinerImpl &IC)
	The caller has matched a pattern of the form: I = icmp ugt (add (add A, B), CI2), CI1 If this is of the form: sum = a + b if (sum+128 >u 255) Then replace it with llvm.sadd.with.overflow.i8.
static Value *	foldICmpOrXorSubChain (ICmpInst &Cmp, BinaryOperator *Or, InstCombiner::BuilderTy &Builder)
	Fold icmp eq/ne (or (xor/sub (X1, X2), xor/sub (X3, X4))), 0.
static Instruction *	foldICmpShlLHSC (ICmpInst &Cmp, Instruction *Shl, const APInt &C)
	Fold icmp (shl nuw C2, Y), C.
static Value *	createLogicFromTable (const std::bitset< 4 > &Table, Value *Op0, Value *Op1, IRBuilderBase &Builder, bool HasOneUse)
static Instruction *	foldCtpopPow2Test (ICmpInst &I, IntrinsicInst *CtpopLhs, const APInt &CRhs, InstCombiner::BuilderTy &Builder, const SimplifyQuery &Q)
static Instruction *	foldICmpIntrinsicWithIntrinsic (ICmpInst &Cmp, InstCombiner::BuilderTy &Builder)
	Fold an icmp with LLVM intrinsics.
static Instruction *	foldICmpUSubSatOrUAddSatWithConstant (CmpPredicate Pred, SaturatingInst *II, const APInt &C, InstCombiner::BuilderTy &Builder)
static Instruction *	foldICmpOfCmpIntrinsicWithConstant (CmpPredicate Pred, IntrinsicInst *I, const APInt &C, InstCombiner::BuilderTy &Builder)
static bool	isMaskOrZero (const Value *V, bool Not, const SimplifyQuery &Q, unsigned Depth=0)
static Value *	foldICmpWithLowBitMaskedVal (CmpPredicate Pred, Value *Op0, Value *Op1, const SimplifyQuery &Q, InstCombiner &IC)
	Some comparisons can be simplified.
static Value *	foldICmpWithTruncSignExtendedVal (ICmpInst &I, InstCombiner::BuilderTy &Builder)
	Some comparisons can be simplified.
static Value *	foldShiftIntoShiftInAnotherHandOfAndInICmp (ICmpInst &I, const SimplifyQuery SQ, InstCombiner::BuilderTy &Builder)
static Instruction *	foldICmpXNegX (ICmpInst &I, InstCombiner::BuilderTy &Builder)
static Instruction *	foldICmpAndXX (ICmpInst &I, const SimplifyQuery &Q, InstCombinerImpl &IC)
static Instruction *	foldICmpOrXX (ICmpInst &I, const SimplifyQuery &Q, InstCombinerImpl &IC)
static Instruction *	foldICmpXorXX (ICmpInst &I, const SimplifyQuery &Q, InstCombinerImpl &IC)
static bool	isMultipleOf (Value *X, const APInt &C, const SimplifyQuery &Q)
	Return true if X is a multiple of C.
static Instruction *	foldICmpPow2Test (ICmpInst &I, InstCombiner::BuilderTy &Builder)
static void	collectOffsetOp (Value *V, SmallVectorImpl< OffsetOp > &Offsets, bool AllowRecursion)
static Instruction *	foldICmpEqualityWithOffset (ICmpInst &I, InstCombiner::BuilderTy &Builder, const SimplifyQuery &SQ)
	Offset both sides of an equality icmp to see if we can save some instructions: icmp eq/ne X, Y -> icmp eq/ne X op Z, Y op Z.
static bool	isNeutralValue (Instruction::BinaryOps BinaryOp, Value *RHS, bool IsSigned)
static Instruction *	processUMulZExtIdiom (ICmpInst &I, Value *MulVal, const APInt *OtherVal, InstCombinerImpl &IC)
	Recognize and process idiom involving test for multiplication overflow.
static APInt	getDemandedBitsLHSMask (ICmpInst &I, unsigned BitWidth)
	When performing a comparison against a constant, it is possible that not all the bits in the LHS are demanded.
static bool	isChainSelectCmpBranch (const SelectInst *SI)
	Return true when the instruction sequence within a block is select-cmp-br.
static ICmpInst *	canonicalizeCmpWithConstant (ICmpInst &I)
	If we have an icmp le or icmp ge instruction with a constant operand, turn it into the appropriate icmp lt or icmp gt instruction.
static Instruction *	canonicalizeICmpBool (ICmpInst &I, InstCombiner::BuilderTy &Builder)
	Integer compare with boolean values can always be turned into bitwise ops.
static Instruction *	foldICmpWithHighBitMask (ICmpInst &Cmp, InstCombiner::BuilderTy &Builder)
static Instruction *	foldVectorCmp (CmpInst &Cmp, InstCombiner::BuilderTy &Builder)
static Instruction *	foldICmpOfUAddOv (ICmpInst &I)
static Instruction *	foldICmpInvariantGroup (ICmpInst &I)
static Instruction *	foldReductionIdiom (ICmpInst &I, InstCombiner::BuilderTy &Builder, const DataLayout &DL)
	This function folds patterns produced by lowering of reduce idioms, such as llvm.vector.reduce.and which are lowered into instruction chains.
static Instruction *	foldFCmpReciprocalAndZero (FCmpInst &I, Instruction *LHSI, Constant *RHSC)
	Fold (C / X) < 0.0 --> X < 0.0 if possible. Swap predicate if necessary.
static Instruction *	foldFCmpFpTrunc (FCmpInst &I, const Instruction &FPTrunc, const Constant &C)
static Instruction *	foldFabsWithFcmpZero (FCmpInst &I, InstCombinerImpl &IC)
	Optimize fabs(X) compared with zero.
static Instruction *	foldSqrtWithFcmpZero (FCmpInst &I, InstCombinerImpl &IC)
	Optimize sqrt(X) compared with zero.
static Instruction *	foldFCmpFNegCommonOp (FCmpInst &I)
static Instruction *	foldFCmpFSubIntoFCmp (FCmpInst &I, Instruction *LHSI, Constant *RHSC, InstCombinerImpl &CI)
static Instruction *	foldFCmpWithFloorAndCeil (FCmpInst &I, InstCombinerImpl &IC)

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "instcombine"

Definition at line 38 of file InstCombineCompares.cpp.

Typedef Documentation

OffsetOp

using OffsetOp = std::pair<Instruction::BinaryOps, Value *>

Find all possible pairs (BinOp, RHS) that BinOp V, RHS can be simplified.

Definition at line 5881 of file InstCombineCompares.cpp.

Enumeration Type Documentation

OffsetKind

enum class OffsetKind

strong

Enumerator
Invalid
Value
Select

Definition at line 5911 of file InstCombineCompares.cpp.

Function Documentation

addWithOverflow()

static bool addWithOverflow ( APInt &  Result, const APInt &  In1, const APInt &  In2, bool  IsSigned = false  )

static

Compute Result = In1+In2, returning true if the result overflowed for this type.

Definition at line 45 of file InstCombineCompares.cpp.

References llvm::APInt::sadd_ov(), and llvm::APInt::uadd_ov().

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

canonicalizeCmpWithConstant()

static ICmpInst * canonicalizeCmpWithConstant ( ICmpInst &  I )

static

If we have an icmp le or icmp ge instruction with a constant operand, turn it into the appropriate icmp lt or icmp gt instruction.

This transform allows them to be folded in visitICmpInst.

Definition at line 7172 of file InstCombineCompares.cpp.

References llvm::getFlippedStrictnessPredicateAndConstant(), I, llvm::InstCombiner::isCanonicalPredicate(), llvm::ICmpInst::isEquality(), and llvm::CmpInst::isIntPredicate().

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

canonicalizeICmpBool()

static Instruction * canonicalizeICmpBool ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder  )

static

Integer compare with boolean values can always be turned into bitwise ops.

Definition at line 7215 of file InstCombineCompares.cpp.

References A, assert(), B, llvm::BinaryOperator::CreateNot(), llvm::IRBuilderBase::CreateNot(), llvm::IRBuilderBase::CreateXor(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm_unreachable, llvm::PatternMatch::m_One(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), and std::swap().

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

canRewriteGEPAsOffset()

static bool canRewriteGEPAsOffset ( Value *  Start, Value *  Base, GEPNoWrapFlags &  NW, const DataLayout &  DL, SetVector< Value * > &  Explored  )

static

Returns true if we can rewrite Start as a GEP with pointer Base and some integer offset.

The nodes that need to be re-written for this transformation will be added to Explored.

Definition at line 434 of file InstCombineCompares.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::sampleprof::Base, llvm::SetVector< T, Vector, Set, N >::contains(), llvm::count_if(), llvm::SmallVectorBase< Size_T >::empty(), GEP, llvm::SetVector< T, Vector, Set, N >::insert(), llvm::GEPNoWrapFlags::intersectForOffsetAdd(), PHI, llvm::SmallVectorTemplateBase< T, bool >::pop_back(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SetVector< T, Vector, Set, N >::size(), and llvm::Value::uses().

Referenced by transformToIndexedCompare().

collectOffsetOp()

static void collectOffsetOp ( Value *  V, SmallVectorImpl< OffsetOp > &  Offsets, bool  AllowRecursion  )

static

Definition at line 5882 of file InstCombineCompares.cpp.

References collectOffsetOp(), llvm::Instruction::getOpcode(), llvm::User::getOperand(), and llvm::Value::hasOneUse().

Referenced by collectOffsetOp(), and foldICmpEqualityWithOffset().

createLogicFromTable()

static Value * createLogicFromTable ( const std::bitset< 4 > &  Table, Value *  Op0, Value *  Op1, IRBuilderBase &  Builder, bool  HasOneUse  )

static

Definition at line 3087 of file InstCombineCompares.cpp.

References llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateNot(), llvm::IRBuilderBase::CreateOr(), llvm::IRBuilderBase::CreateXor(), llvm::IRBuilderBase::getFalse(), llvm::ConstantVector::getSplat(), llvm::IRBuilderBase::getTrue(), llvm::Value::getType(), llvm::Type::isVectorTy(), and llvm_unreachable.

Referenced by llvm::InstCombinerImpl::foldICmpAddConstant(), and llvm::InstCombinerImpl::foldICmpBinOpWithConstantViaTruthTable().

foldCtpopPow2Test()

static Instruction * foldCtpopPow2Test ( ICmpInst &  I, IntrinsicInst *  CtpopLhs, const APInt &  CRhs, InstCombiner::BuilderTy &  Builder, const SimplifyQuery &  Q  )

static

Definition at line 3798 of file InstCombineCompares.cpp.

References llvm::SimplifyQuery::AC, assert(), llvm::computeKnownBits(), llvm::KnownBits::countMinPopulation(), llvm::IRBuilderBase::CreateAnd(), llvm::SimplifyQuery::CxtI, llvm::SimplifyQuery::DL, llvm::SimplifyQuery::DT, llvm::CallBase::getArgOperand(), llvm::Constant::getIntegerValue(), llvm::IntrinsicInst::getIntrinsicID(), llvm::Constant::getNullValue(), llvm::Value::hasOneUse(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, and llvm::KnownBits::One.

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

foldFabsWithFcmpZero()

static Instruction * foldFabsWithFcmpZero ( FCmpInst &  I, InstCombinerImpl &  IC  )

static

Optimize fabs(X) compared with zero.

Definition at line 8356 of file InstCombineCompares.cpp.

References assert(), llvm::CallingConv::C, F, 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_UEQ, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::CmpInst::FCMP_UNE, llvm::CmpInst::FCMP_UNO, llvm::ConstantFP::getZero(), I, llvm_unreachable, llvm::PatternMatch::m_APFloat(), llvm::PatternMatch::m_FAbs(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), P, llvm::DenormalMode::PositiveZero, llvm::DenormalMode::PreserveSign, llvm::InstCombiner::replaceOperand(), and X.

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

foldFCmpFNegCommonOp()

static Instruction * foldFCmpFNegCommonOp ( FCmpInst &  I )

static

Definition at line 8517 of file InstCombineCompares.cpp.

References llvm::Value::getType(), llvm::ConstantFP::getZero(), I, llvm::PatternMatch::m_FNeg(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and std::swap().

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

foldFCmpFpTrunc()

static Instruction * foldFCmpFpTrunc ( FCmpInst &  I, const Instruction &  FPTrunc, const Constant &  C  )

static

Definition at line 8271 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::APFloat::convert(), llvm::CmpInst::FCMP_OGE, llvm::CmpInst::FCMP_OGT, llvm::CmpInst::FCMP_OLE, llvm::CmpInst::FCMP_OLT, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::Type::getFltSemantics(), llvm::User::getOperand(), llvm::Type::getScalarType(), llvm::Value::getType(), I, llvm::isFinite(), llvm::APFloat::isInfinity(), llvm::APFloat::isNaN(), llvm::PatternMatch::m_APFloat(), llvm::PatternMatch::match(), llvm::APFloat::next(), llvm::APFloatBase::rmNearestTiesToEven, and llvm::scalbn().

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

foldFCmpFSubIntoFCmp()

static Instruction * foldFCmpFSubIntoFCmp ( FCmpInst &  I, Instruction *  LHSI, Constant *  RHSC, InstCombinerImpl &  CI  )

static

Definition at line 8536 of file InstCombineCompares.cpp.

References 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_UEQ, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::CmpInst::FCMP_UNE, llvm::Type::getFltSemantics(), llvm::DenormalMode::getIEEE(), llvm::User::getOperand(), llvm::Type::getScalarType(), llvm::InstCombiner::getSimplifyQuery(), llvm::Value::getType(), llvm::SimplifyQuery::getWithInstruction(), llvm::Instruction::hasNoInfs(), llvm::Instruction::hasNoNaNs(), I, llvm::isKnownNeverInfinity(), llvm::PatternMatch::m_AnyZeroFP(), llvm::PatternMatch::match(), llvm::InstCombiner::replaceOperand(), X, and Y.

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

foldFCmpReciprocalAndZero()

static Instruction * foldFCmpReciprocalAndZero ( FCmpInst &  I, Instruction *  LHSI, Constant *  RHSC  )

static

Fold (C / X) < 0.0 --> X < 0.0 if possible. Swap predicate if necessary.

Definition at line 8217 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::CmpInst::FCMP_OGE, llvm::CmpInst::FCMP_OGT, llvm::CmpInst::FCMP_OLE, llvm::CmpInst::FCMP_OLT, llvm::User::getOperand(), llvm::Instruction::hasNoInfs(), I, llvm::PatternMatch::m_AnyZeroFP(), llvm::PatternMatch::m_APFloat(), and llvm::PatternMatch::match().

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

foldFCmpWithFloorAndCeil()

static Instruction * foldFCmpWithFloorAndCeil ( FCmpInst &  I, InstCombinerImpl &  IC  )

static

Definition at line 8582 of file InstCombineCompares.cpp.

References llvm::CmpInst::FCMP_OGE, llvm::CmpInst::FCMP_OGT, llvm::CmpInst::FCMP_OLE, llvm::CmpInst::FCMP_OLT, llvm::CmpInst::FCMP_ORD, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::CmpInst::FCMP_UNO, llvm::ConstantInt::getFalse(), llvm::ConstantInt::getTrue(), llvm::Value::getType(), llvm::ConstantFP::getZero(), I, LHS, llvm::PatternMatch::m_Specific(), llvm::PatternMatch::match(), llvm::InstCombiner::replaceInstUsesWith(), RHS, and std::swap().

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

foldICmpAndXX()

static Instruction * foldICmpAndXX ( ICmpInst &  I, const SimplifyQuery &  Q, InstCombinerImpl &  IC  )

static

Definition at line 5013 of file InstCombineCompares.cpp.

References A, llvm::InstCombiner::Builder, llvm::InstCombiner::computeKnownBits(), llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateOr(), llvm::Constant::getAllOnesValue(), llvm::CmpInst::getFlippedStrictnessPredicate(), llvm::InstCombiner::getFreelyInverted(), llvm::Constant::getNullValue(), llvm::InstCombiner::getSimplifyQuery(), llvm::CmpInst::getSwappedPredicate(), llvm::ICmpInst::getUnsignedPredicate(), llvm::SimplifyQuery::getWithInstruction(), llvm::Value::hasOneUse(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULT, llvm::ICmpInst::isEquality(), llvm::isKnownNegative(), llvm::KnownBits::isNegative(), llvm::KnownBits::isNonNegative(), llvm::CmpInst::isSigned(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_ImmConstant(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and std::swap().

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

foldICmpEqualityWithOffset()

static Instruction * foldICmpEqualityWithOffset ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder, const SimplifyQuery &  SQ  )

static

Offset both sides of an equality icmp to see if we can save some instructions: icmp eq/ne X, Y -> icmp eq/ne X op Z, Y op Z.

Note: This operation should not introduce poison.

Definition at line 5943 of file InstCombineCompares.cpp.

References assert(), collectOffsetOp(), llvm::Value::getType(), I, llvm::impliesPoison(), OffsetResult::invalid(), llvm::Type::isIntOrIntVectorTy(), llvm::PatternMatch::m_ImmConstant(), llvm::PatternMatch::match(), RHS, OffsetResult::select(), llvm::simplifyBinOp(), and OffsetResult::value().

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

foldICmpIntrinsicWithIntrinsic()

static Instruction * foldICmpIntrinsicWithIntrinsic ( ICmpInst &  Cmp, InstCombiner::BuilderTy &  Builder  )

static

Fold an icmp with LLVM intrinsics.

Definition at line 3944 of file InstCombineCompares.cpp.

References assert(), llvm::IRBuilderBase::CreateIntrinsic(), llvm::IRBuilderBase::CreateSub(), llvm::Value::getType(), llvm::PatternMatch::m_ImmConstant(), and llvm::PatternMatch::match().

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

foldICmpInvariantGroup()

static Instruction * foldICmpInvariantGroup ( ICmpInst &  I )

static

Definition at line 7435 of file InstCombineCompares.cpp.

References llvm::CmpInst::Create(), I, llvm::PatternMatch::m_Instruction(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), and llvm::NullPointerIsDefined().

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

foldICmpOfCmpIntrinsicWithConstant()

static Instruction * foldICmpOfCmpIntrinsicWithConstant ( CmpPredicate  Pred, IntrinsicInst *  I, const APInt &  C, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 4171 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::ICmpInst::getSignedPredicate(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, LHS, and RHS.

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

foldICmpOfUAddOv()

static Instruction * foldICmpOfUAddOv ( ICmpInst &  I )

static

Definition at line 7407 of file InstCombineCompares.cpp.

References A, B, llvm::ExtractValueInst::Create(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_Value(), llvm::MIPatternMatch::m_ZeroInt(), and llvm::PatternMatch::match().

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

foldICmpOrXorSubChain()

static Value * foldICmpOrXorSubChain ( ICmpInst &  Cmp, BinaryOperator *  Or, InstCombiner::BuilderTy &  Builder  )

static

Fold icmp eq/ne (or (xor/sub (X1, X2), xor/sub (X3, X4))), 0.

Definition at line 2061 of file InstCombineCompares.cpp.

References llvm::IRBuilderBase::CreateBinOp(), llvm::IRBuilderBase::CreateICmp(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::SmallVectorBase< Size_T >::empty(), llvm::CmpInst::ICMP_EQ, llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Sub(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Xor(), llvm::PatternMatch::match(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorTemplateCommon< T, typename >::rbegin(), and llvm::SmallVectorTemplateCommon< T, typename >::rend().

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

foldICmpOrXX()

static Instruction * foldICmpOrXX ( ICmpInst &  I, const SimplifyQuery &  Q, InstCombinerImpl &  IC  )

static

Definition at line 5075 of file InstCombineCompares.cpp.

References A, llvm::InstCombiner::Builder, llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateOr(), llvm::Constant::getAllOnesValue(), llvm::InstCombiner::getFreelyInverted(), llvm::Constant::getNullValue(), llvm::CmpInst::getSwappedPredicate(), llvm::Value::hasOneUse(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::ICmpInst::isEquality(), llvm::PatternMatch::m_c_Or(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and std::swap().

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

foldICmpPow2Test()

static Instruction * foldICmpPow2Test ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 5828 of file InstCombineCompares.cpp.

References A, llvm::IRBuilderBase::CreateUnaryIntrinsic(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::CmpInst::isUnsigned(), llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_c_Xor(), llvm::PatternMatch::m_Deferred(), llvm::MIPatternMatch::m_Neg(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::MIPatternMatch::m_ZeroInt(), and llvm::PatternMatch::match().

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

foldICmpShlLHSC()

static Instruction * foldICmpShlLHSC ( ICmpInst &  Cmp, Instruction *  Shl, const APInt &  C  )

static

Fold icmp (shl nuw C2, Y), C.

Definition at line 2312 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::Value::getType(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::APInt::isOne(), llvm::APInt::isPowerOf2(), llvm::APInt::isZero(), llvm::APInt::logBase2(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_NUWShl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::APInt::udivrem(), llvm::APInt::ugt(), and Y.

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

foldICmpUSubSatOrUAddSatWithConstant()

static Instruction * foldICmpUSubSatOrUAddSatWithConstant ( CmpPredicate  Pred, SaturatingInst *  II, const APInt &  C, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 4086 of file InstCombineCompares.cpp.

References llvm::ConstantRange::add(), llvm::CallingConv::C, llvm::ICmpInst::compare(), llvm::IRBuilderBase::CreateAdd(), llvm::ConstantRange::exactIntersectWith(), llvm::ConstantRange::exactUnionWith(), llvm::APInt::getAllOnes(), llvm::Value::getType(), llvm::APInt::getZero(), II, llvm::ConstantRange::inverse(), llvm_unreachable, llvm::PatternMatch::m_APInt(), llvm::ConstantRange::makeExactICmpRegion(), llvm::ConstantRange::makeExactNoWrapRegion(), llvm::PatternMatch::match(), and llvm::ConstantRange::sub().

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

foldICmpWithHighBitMask()

static Instruction * foldICmpWithHighBitMask ( ICmpInst &  Cmp, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 7294 of file InstCombineCompares.cpp.

References llvm::CmpInst::Create(), llvm::IRBuilderBase::CreateLShr(), llvm::Constant::getNullValue(), llvm::Value::getType(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_c_ICmp(), llvm::PatternMatch::m_CombineOr(), llvm::MIPatternMatch::m_Not(), llvm::PatternMatch::m_One(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

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

foldICmpWithLowBitMaskedVal()

static Value * foldICmpWithLowBitMaskedVal ( CmpPredicate  Pred, Value *  Op0, Value *  Op1, const SimplifyQuery &  Q, InstCombiner &  IC  )

static

Some comparisons can be simplified.

In this case, we are looking for comparisons that look like a check for a lossy truncation. Folds: icmp SrcPred (x & Mask), x to icmp DstPred x, Mask icmp SrcPred (x & ~Mask), ~Mask to icmp DstPred x, ~Mask icmp eq/ne (x & ~Mask), 0 to icmp DstPred x, Mask icmp eq/ne (~x | Mask), -1 to icmp DstPred x, Mask Where Mask is some pattern that produces all-ones in low bits: (-1 >> y) ((-1 << y) >> y) <- non-canonical, has extra uses ~(-1 << y) ((1 << y) + (-1)) <- non-canonical, has extra uses The Mask can be a constant, too. For some predicates, the operands are commutative. For others, x can only be on a specific side.

Definition at line 4536 of file InstCombineCompares.cpp.

References llvm::InstCombiner::Builder, Check, llvm::IRBuilderBase::CreateICmp(), llvm::InstCombiner::getFreelyInverted(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::ICmpInst::isEquality(), llvm::isKnownNonNegative(), llvm::isKnownNonZero(), isMaskOrZero(), llvm::CmpInst::isSigned(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_And(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_NonNegative(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), std::swap(), and X.

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

foldICmpWithTruncSignExtendedVal()

static Value * foldICmpWithTruncSignExtendedVal ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder  )

static

Some comparisons can be simplified.

In this case, we are looking for comparisons that look like a check for a lossy signed truncation. Folds: (MaskedBits is a constant.) ((x << MaskedBits) a>> MaskedBits) SrcPred x Into: (add x, (1 << (KeptBits-1))) DstPred (1 << KeptBits) Where KeptBits = bitwidth(x) - MaskedBits

Definition at line 4666 of file InstCombineCompares.cpp.

References assert(), llvm::BitWidth, llvm::IRBuilderBase::CreateAdd(), llvm::IRBuilderBase::CreateICmp(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULT, llvm::APInt::isPowerOf2(), llvm::APInt::lshr(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_AShr(), llvm::PatternMatch::m_c_ICmp(), llvm::PatternMatch::m_Deferred(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::APInt::shl(), T1, llvm::APInt::ugt(), llvm::APInt::ult(), and X.

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

foldICmpXNegX()

static Instruction * foldICmpXNegX ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 4981 of file InstCombineCompares.cpp.

References llvm::BitWidth, llvm::CmpInst::Create(), llvm::IRBuilderBase::CreateAnd(), llvm::Constant::getNullValue(), llvm::Type::getScalarSizeInBits(), llvm::APInt::getSignedMaxValue(), llvm::ICmpInst::getSignedPredicate(), llvm::CmpInst::getSwappedPredicate(), I, llvm::ICmpInst::isEquality(), llvm::CmpInst::isSigned(), llvm::CmpInst::isUnsigned(), llvm::PatternMatch::m_c_ICmp(), llvm::PatternMatch::m_Deferred(), llvm::MIPatternMatch::m_Neg(), llvm::PatternMatch::m_NSWNeg(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and X.

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

foldICmpXorXX()

static Instruction * foldICmpXorXX ( ICmpInst &  I, const SimplifyQuery &  Q, InstCombinerImpl &  IC  )

static

Definition at line 5110 of file InstCombineCompares.cpp.

References A, llvm::Constant::getNullValue(), llvm::CmpInst::getStrictPredicate(), llvm::CmpInst::getSwappedPredicate(), llvm::Value::getType(), I, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::isKnownNonZero(), llvm::PatternMatch::m_c_Xor(), llvm::PatternMatch::m_Negative(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and std::swap().

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

foldReductionIdiom()

static Instruction * foldReductionIdiom ( ICmpInst &  I, InstCombiner::BuilderTy &  Builder, const DataLayout &  DL  )

static

This function folds patterns produced by lowering of reduce idioms, such as llvm.vector.reduce.and which are lowered into instruction chains.

This code attempts to generate fewer number of scalar comparisons instead of vector comparisons when possible.

vec_ne = icmp ne <8 x i8> lhs, rhs scalar_ne = bitcast <8 x i1> vec_ne to i8 res = icmp <pred> i8 scalar_ne, 0

into

lhs.scalar = bitcast <8 x i8> lhs to i64 rhs.scalar = bitcast <8 x i8> rhs to i64 res = icmp <pred> i64 lhs.scalar, rhs.scalar

for <pred> in {ne, eq}.

Definition at line 7456 of file InstCombineCompares.cpp.

References llvm::CmpInst::Create(), llvm::IRBuilderBase::CreateBitCast(), DL, llvm::IRBuilderBase::getIntNTy(), llvm::Value::getName(), llvm::Value::getType(), I, llvm::CmpInst::ICMP_NE, llvm::ICmpInst::isEquality(), LHS, llvm::PatternMatch::m_BitCast(), llvm::PatternMatch::m_ICmp(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), and RHS.

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

foldShiftIntoShiftInAnotherHandOfAndInICmp()

static Value * foldShiftIntoShiftInAnotherHandOfAndInICmp ( ICmpInst &  I, const SimplifyQuery  SQ, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 4740 of file InstCombineCompares.cpp.

References assert(), llvm::CallingConv::C, llvm::computeKnownBits(), llvm::ConstantFoldCastOperand(), llvm::KnownBits::countMinLeadingZeros(), llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateICmp(), llvm::IRBuilderBase::CreateLShr(), llvm::IRBuilderBase::CreateShl(), llvm::IRBuilderBase::CreateZExt(), llvm::SimplifyQuery::DL, llvm::APInt::getAllOnes(), llvm::KnownBits::getBitWidth(), llvm::Constant::getNullValue(), llvm::Instruction::getOpcode(), llvm::User::getOperand(), llvm::Type::getScalarSizeInBits(), llvm::Value::getType(), llvm::Constant::getUniqueInteger(), llvm::SimplifyQuery::getWithInstruction(), llvm::Value::hasOneUse(), I, llvm::CmpInst::ICMP_ULT, llvm::Constant::isNullValue(), llvm::Type::isVectorTy(), llvm::PatternMatch::m_BinOp(), llvm::PatternMatch::m_c_And(), llvm::PatternMatch::m_CombineAnd(), llvm::PatternMatch::m_Instruction(), llvm::PatternMatch::m_LogicalShift(), llvm::PatternMatch::m_LShr(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_SpecificInt_ICMP(), llvm::PatternMatch::m_TruncOrSelf(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::m_ZExtOrSelf(), llvm::PatternMatch::match(), llvm::simplifyAddInst(), std::swap(), T1, llvm::APInt::ule(), llvm::APInt::ult(), X, and Y.

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

foldSqrtWithFcmpZero()

static Instruction * foldSqrtWithFcmpZero ( FCmpInst &  I, InstCombinerImpl &  IC  )

static

Optimize sqrt(X) compared with zero.

Definition at line 8457 of file InstCombineCompares.cpp.

References 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_UEQ, llvm::CmpInst::FCMP_UGE, llvm::CmpInst::FCMP_UGT, llvm::CmpInst::FCMP_ULE, llvm::CmpInst::FCMP_ULT, llvm::CmpInst::FCMP_UNE, llvm::CmpInst::FCMP_UNO, I, llvm_unreachable, llvm::PatternMatch::m_PosZeroFP(), llvm::PatternMatch::m_Sqrt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), P, llvm::InstCombiner::replaceOperand(), and X.

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

foldVectorCmp()

static Instruction * foldVectorCmp ( CmpInst &  Cmp, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 7337 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::CallInst::Create(), llvm::IRBuilderBase::CreateCmp(), F, llvm::Intrinsic::getOrInsertDeclaration(), llvm::ConstantVector::getSplat(), llvm::Value::getType(), llvm::Value::hasOneUse(), I, llvm::isSplatValue(), LHS, llvm::PatternMatch::m_Constant(), llvm::MIPatternMatch::m_OneUse(), llvm::PatternMatch::m_Shuffle(), llvm::PatternMatch::m_Undef(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_VecReverse(), llvm::PatternMatch::match(), RHS, X, and Y.

Referenced by llvm::InstCombinerImpl::visitFCmpInst(), and llvm::InstCombinerImpl::visitICmpInst().

getDemandedBitsLHSMask()

static APInt getDemandedBitsLHSMask ( ICmpInst &  I, unsigned  BitWidth  )

static

When performing a comparison against a constant, it is possible that not all the bits in the LHS are demanded.

This helper method computes the mask that IS demanded.

Definition at line 6728 of file InstCombineCompares.cpp.

References llvm::BitWidth, llvm::APInt::getAllOnes(), llvm::APInt::getBitsSetFrom(), llvm::APInt::getSignMask(), I, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::isSignBitCheck(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::match(), and RHS.

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

hasBranchUse()

static bool hasBranchUse ( ICmpInst &  I )

static

Given an icmp instruction, return true if any use of this comparison is a branch on sign bit comparison.

Definition at line 71 of file InstCombineCompares.cpp.

References I.

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

isChainSelectCmpBranch()

static bool isChainSelectCmpBranch ( const SelectInst *  SI )

static

Return true when the instruction sequence within a block is select-cmp-br.

Definition at line 6789 of file InstCombineCompares.cpp.

References llvm::BasicBlock::getTerminator().

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

isMaskOrZero()

static bool isMaskOrZero ( const Value *  V, bool  Not, const SimplifyQuery &  Q, unsigned  Depth = 0  )

static

Definition at line 4429 of file InstCombineCompares.cpp.

References llvm::SimplifyQuery::AC, llvm::SimplifyQuery::CxtI, llvm::Depth, llvm::SimplifyQuery::DL, llvm::SimplifyQuery::DT, I, II, llvm::isKnownToBeAPowerOfTwo(), isMaskOrZero(), llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_c_Xor(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_LowBitMaskOrZero(), llvm::MIPatternMatch::m_Neg(), llvm::PatternMatch::m_NegatedPower2OrZero(), llvm::MIPatternMatch::m_Not(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), llvm::MaxAnalysisRecursionDepth, and X.

Referenced by foldICmpWithLowBitMaskedVal(), and isMaskOrZero().

isMultipleOf()

static bool isMultipleOf ( Value *  X, const APInt &  C, const SimplifyQuery &  Q  )

static

Return true if X is a multiple of C.

TODO: Handle non-power-of-2 factors.

Definition at line 5156 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::MaskedValueIsZero(), and X.

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

isNeutralValue()

static bool isNeutralValue ( Instruction::BinaryOps  BinaryOp, Value *  RHS, bool  IsSigned  )

static

Definition at line 6479 of file InstCombineCompares.cpp.

References llvm::Value::getType(), llvm::Type::isIntOrIntVectorTy(), llvm_unreachable, llvm::PatternMatch::m_One(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), and RHS.

isSignTest()

static bool isSignTest ( ICmpInst::Predicate &  Pred, const APInt &  C  )

static

Returns true if the exploded icmp can be expressed as a signed comparison to zero and updates the predicate accordingly.

The signedness of the comparison is preserved. TODO: Refactor with decomposeBitTestICmp()?

Definition at line 82 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, and llvm::ICmpInst::isRelational().

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

processUGT_ADDCST_ADD()

static Instruction * processUGT_ADDCST_ADD ( ICmpInst &  I, Value *  A, Value *  B, ConstantInt *  CI2, ConstantInt *  CI1, InstCombinerImpl &  IC  )

static

The caller has matched a pattern of the form: I = icmp ugt (add (add A, B), CI2), CI1 If this is of the form: sum = a + b if (sum+128 >u 255) Then replace it with llvm.sadd.with.overflow.i8.

Definition at line 1101 of file InstCombineCompares.cpp.

References A, llvm::Add, B, llvm::InstCombiner::Builder, llvm::InstCombiner::ComputeMaxSignificantBits(), llvm::APInt::countr_zero(), llvm::ExtractValueInst::Create(), llvm::IRBuilderBase::CreateCall(), llvm::IRBuilderBase::CreateExtractValue(), llvm::IRBuilderBase::CreateTrunc(), llvm::IRBuilderBase::CreateZExt(), llvm::InstCombinerImpl::eraseInstFromFunction(), F, llvm::IntegerType::get(), llvm::ConstantInt::getBitWidth(), llvm::Value::getContext(), llvm::APInt::getLowBitsSet(), llvm::User::getOperand(), llvm::Intrinsic::getOrInsertDeclaration(), llvm::Type::getPrimitiveSizeInBits(), llvm::Value::getType(), llvm::ConstantInt::getValue(), llvm::Value::hasOneUse(), I, llvm::APInt::isPowerOf2(), llvm::InstCombiner::replaceInstUsesWith(), llvm::IRBuilderBase::SetInsertPoint(), and llvm::Value::users().

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

processUMulZExtIdiom()

static Instruction * processUMulZExtIdiom ( ICmpInst &  I, Value *  MulVal, const APInt *  OtherVal, InstCombinerImpl &  IC  )

static

Recognize and process idiom involving test for multiplication overflow.

The caller has matched a pattern of the form: I = cmp u (mul(zext A, zext B), V The function checks if this is a test for overflow and if so replaces multiplication with call to 'mul.with.overflow' intrinsic.

Parameters

I	Compare instruction.
MulVal	Result of 'mult' instruction. It is one of the arguments of the compare instruction. Must be of integer type.
OtherVal	The other argument of compare instruction.

Returns

Instruction which must replace the compare instruction, NULL if no replacement required.

Definition at line 6581 of file InstCombineCompares.cpp.

References A, llvm::InstCombiner::addToWorklist(), assert(), B, llvm::InstCombiner::Builder, llvm::APInt::countl_zero(), llvm::ExtractValueInst::Create(), llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateExtractValue(), llvm::IRBuilderBase::CreateIntrinsic(), llvm::BinaryOperator::CreateNot(), llvm::IRBuilderBase::CreateZExt(), llvm::APInt::eq(), llvm::APInt::getBitWidth(), llvm::APInt::getMaxValue(), llvm::APInt::getOneBitSet(), llvm::Type::getPrimitiveSizeInBits(), llvm::Value::getType(), llvm::ConstantInt::getValue(), llvm::Value::hasNUsesOrMore(), I, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, LHS, llvm_unreachable, llvm::make_early_inc_range(), llvm::Mul, llvm::InstCombiner::replaceInstUsesWith(), RHS, llvm::IRBuilderBase::SetInsertPoint(), llvm::User::setOperand(), llvm::APInt::trunc(), llvm::Value::users(), and llvm::APInt::zext().

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

rewriteGEPAsOffset()

static Value * rewriteGEPAsOffset ( Value *  Start, Value *  Base, GEPNoWrapFlags  NW, const DataLayout &  DL, SetVector< Value * > &  Explored, InstCombiner &  IC  )

static

Returns a re-written value of Start as an indexed GEP using Base as a pointer.

Definition at line 548 of file InstCombineCompares.cpp.

References llvm::PHINode::addIncoming(), llvm::InstCombiner::addToWorklist(), llvm::sampleprof::Base, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::contains(), llvm::PHINode::Create(), llvm::IRBuilderBase::CreateAdd(), llvm::IRBuilderBase::CreateGEP(), DL, llvm::emitGEPOffset(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), GEP, llvm::IntegerType::get(), llvm::IRBuilderBase::getInt8Ty(), llvm::Constant::getNullValue(), llvm::GEPNoWrapFlags::hasNoUnsignedSignedWrap(), llvm::GEPNoWrapFlags::hasNoUnsignedWrap(), I, isZero(), llvm_unreachable, PHI, llvm::InstCombiner::replaceInstUsesWith(), and setInsertionPoint().

Referenced by transformToIndexedCompare().

setInsertionPoint()

static void setInsertionPoint ( IRBuilder<> &  Builder, Value *  V, bool  Before = true  )

static

Definition at line 522 of file InstCombineCompares.cpp.

References A, assert(), llvm::BasicBlock::getFirstInsertionPt(), I, PHI, and llvm::IRBuilderBase::SetInsertPoint().

Referenced by rewriteGEPAsOffset().

STATISTIC()

STATISTIC	(	NumSel	,
		"Number of select opts"
	)

subWithOverflow()

static bool subWithOverflow ( APInt &  Result, const APInt &  In1, const APInt &  In2, bool  IsSigned = false  )

static

Compute Result = In1-In2, returning true if the result overflowed for this type.

Definition at line 58 of file InstCombineCompares.cpp.

References llvm::APInt::ssub_ov(), and llvm::APInt::usub_ov().

Referenced by llvm::InstCombinerImpl::foldICmpDivConstant(), and llvm::InstCombinerImpl::foldICmpSubConstant().

transformToIndexedCompare()

static Instruction * transformToIndexedCompare ( GEPOperator *  GEPLHS, Value *  RHS, CmpPredicate  Cond, const DataLayout &  DL, InstCombiner &  IC  )

static

Converts (CMP GEPLHS, RHS) if this change would make RHS a constant.

We can look through PHIs, GEPs and casts in order to determine a common base between GEPLHS and RHS.

Definition at line 642 of file InstCombineCompares.cpp.

References llvm::InstCombiner::Builder, canRewriteGEPAsOffset(), Cond, DL, llvm::IRBuilderBase::getInt(), llvm::GEPOperator::getNoWrapFlags(), llvm::ICmpInst::getSignedPredicate(), llvm::Value::getType(), llvm::GEPOperator::hasAllConstantIndices(), llvm::Type::isVectorTy(), llvm::Offset, rewriteGEPAsOffset(), RHS, and llvm::Value::stripAndAccumulateConstantOffsets().

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