LLVM: lib/Transforms/InstCombine/InstCombineCompares.cpp File Reference (original) (raw)

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◆ DEBUG_TYPE

#define DEBUG_TYPE "instcombine"

◆ OffsetOp

◆ OffsetKind

◆ addWithOverflow()

◆ canonicalizeCmpWithConstant()

◆ canonicalizeICmpBool()

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

Definition at line 7239 of file InstCombineCompares.cpp.

References A(), assert(), B(), llvm::BinaryOperator::CreateNot(), 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()

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 393 of file InstCombineCompares.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::sampleprof::Base, llvm::SetVector< T, Vector, Set, N >::contains(), llvm::count_if(), DL, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), GEP, llvm::SetVector< T, Vector, Set, N >::insert(), llvm::GEPNoWrapFlags::intersectForOffsetAdd(), llvm::isa(), 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()

◆ createLogicFromTable()

◆ foldCtpopPow2Test()

Definition at line 3756 of file InstCombineCompares.cpp.

References llvm::SimplifyQuery::AC, assert(), llvm::computeKnownBits(), llvm::KnownBits::countMinPopulation(), 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()

Optimize fabs(X) compared with zero.

Definition at line 8384 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(), Mode, P, llvm::DenormalMode::PositiveZero, llvm::DenormalMode::PreserveSign, llvm::InstCombiner::replaceOperand(), and X.

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

◆ foldFCmpFNegCommonOp()

◆ foldFCmpFpTrunc()

Definition at line 8299 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()

Definition at line 8564 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()

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

Definition at line 8245 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()

Definition at line 8613 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::ConstantFP::getZero(), I, LHS, llvm::PatternMatch::m_Intrinsic(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::match(), llvm::InstCombiner::replaceInstUsesWith(), RHS, and std::swap().

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

◆ foldICmpAndXX()

Definition at line 4970 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()

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 5945 of file InstCombineCompares.cpp.

References llvm::APInt::ashr(), assert(), collectOffsetOp(), llvm::dyn_cast(), llvm::Value::getType(), I, llvm::impliesPoison(), OffsetResult::invalid(), llvm::isa(), llvm::Type::isIntOrIntVectorTy(), llvm::APInt::lshr(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_ImmConstant(), llvm::PatternMatch::m_NSWShl(), llvm::PatternMatch::m_NUWShl(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), RHS, OffsetResult::select(), llvm::APInt::shl(), llvm::simplifyBinOp(), and OffsetResult::value().

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

◆ foldICmpIntrinsicWithIntrinsic()

◆ foldICmpInvariantGroup()

◆ foldICmpOfCmpIntrinsicWithConstant()

Definition at line 4129 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()

Definition at line 7431 of file InstCombineCompares.cpp.

References A(), B(), llvm::cast(), 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_ExtractValue(), llvm::PatternMatch::m_Intrinsic(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_Value(), llvm::MIPatternMatch::m_ZeroInt(), and llvm::PatternMatch::match().

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

◆ foldICmpOrXorSubChain()

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

Definition at line 2022 of file InstCombineCompares.cpp.

References llvm::SmallVectorImpl< T >::emplace_back(), llvm::SmallVectorTemplateCommon< T, typename >::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()

Definition at line 5032 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::isa(), 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()

Definition at line 5824 of file InstCombineCompares.cpp.

References A(), 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()

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

Definition at line 2273 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()

Definition at line 4044 of file InstCombineCompares.cpp.

References llvm::ConstantRange::add(), llvm::CallingConv::C, llvm::ICmpInst::compare(), 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()

Definition at line 7318 of file InstCombineCompares.cpp.

References llvm::CmpInst::Create(), 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()

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 4493 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()

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 4623 of file InstCombineCompares.cpp.

References assert(), llvm::BitWidth, 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()

Definition at line 4938 of file InstCombineCompares.cpp.

References llvm::BitWidth, llvm::CmpInst::Create(), llvm::Constant::getNullValue(), 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()

Definition at line 5067 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()

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 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 i64 lhs.scalar, rhs.scalar

for in {ne, eq}.

Definition at line 7480 of file InstCombineCompares.cpp.

References llvm::CmpInst::Create(), DL, llvm::dyn_cast(), 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()

Definition at line 4697 of file InstCombineCompares.cpp.

References assert(), llvm::CallingConv::C, llvm::computeKnownBits(), llvm::ConstantFoldCastOperand(), llvm::KnownBits::countMinLeadingZeros(), llvm::SimplifyQuery::DL, llvm::dyn_cast(), llvm::dyn_cast_or_null(), 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::isa(), 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()

Optimize sqrt(X) compared with zero.

Definition at line 8485 of file InstCombineCompares.cpp.

References llvm::cast(), 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()

Definition at line 7361 of file InstCombineCompares.cpp.

References llvm::CallingConv::C, llvm::cast(), llvm::CallInst::Create(), llvm::dyn_cast(), F, llvm::Intrinsic::getOrInsertDeclaration(), llvm::ConstantVector::getSplat(), llvm::Value::getType(), 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()

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 6752 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()

◆ isChainSelectCmpBranch()

◆ isMaskOrZero()

Definition at line 4386 of file InstCombineCompares.cpp.

References llvm::SimplifyQuery::AC, llvm::SimplifyQuery::CxtI, llvm::Depth, llvm::SimplifyQuery::DL, llvm::SimplifyQuery::DT, llvm::dyn_cast(), 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()

◆ isNeutralValue()

◆ isSignTest()

◆ processUGT_ADDCST_ADD()

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 1060 of file InstCombineCompares.cpp.

References A(), llvm::Add, B(), llvm::InstCombiner::Builder, Call, llvm::cast(), llvm::InstCombiner::ComputeMaxSignificantBits(), llvm::APInt::countr_zero(), llvm::ExtractValueInst::Create(), llvm::dyn_cast(), 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()

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

Returns

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

Definition at line 6605 of file InstCombineCompares.cpp.

References A(), llvm::InstCombiner::addToWorklist(), assert(), B(), llvm::InstCombiner::Builder, Call, llvm::cast(), llvm::APInt::countl_zero(), llvm::ExtractValueInst::Create(), llvm::BinaryOperator::CreateNot(), llvm::dyn_cast(), 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, llvm::isa(), LHS, llvm_unreachable, llvm::make_early_inc_range(), 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()

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

Definition at line 507 of file InstCombineCompares.cpp.

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

Referenced by transformToIndexedCompare().

◆ setInsertionPoint()

◆ STATISTIC()

◆ subWithOverflow()

◆ transformToIndexedCompare()

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 601 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().